JP5050375B2 - Display panel and manufacturing method thereof - Google Patents

Description

  The present invention relates to a display panel having a gloss and texture such as a metallic tone and a method for manufacturing the display panel.

  Conventionally, as a display panel such as a speedometer of an automobile, for example, a display panel having a gloss and texture such as a metallic tone has been manufactured. Specifically, for example, as shown in FIG. 18, there is a display panel 8 having a colored design layer 89 such as a metal color and a scratch pattern layer 81 formed by screen printing on a resin substrate 80. The scratch pattern layer 81 is formed by screen printing so that convex portions 811 having a thickness larger than the surroundings are formed by screen printing, and the concave portions 812 having the thickness smaller than the convex portions 811 and the convex portions 811 are alternately arranged. Was formed to go. In such a display panel 8, gloss and texture can be imparted to the color and pattern of the design layer 3 by the scratch pattern layer 81. For example, the display panel 8 can express gloss and texture such as metal or wood grain by applying a color or pattern such as metal tone or wood grain as the design layer 89. The scratch pattern layer 81 was formed by printing a plurality of lines (convex portions 811) by screen printing, for example.

  In the conventional method of forming the line 811 by screen printing, the minimum value of the individual line width is about 0.2 mm, and the minimum value of the line interval is about 0.3 mm. If the line width and the line interval are made finer than this, there is a problem that the line 811 is bent and the adjacent lines 811 are crushed. For this reason, it has been impossible to satisfy the fineness required to more fully express the glossiness and texture of metals and the like.

As a method for expressing glossiness and texture such as a metallic tone by a method other than screen printing, for example, as shown in FIG. Yes (see Patent Document 1 and Patent Document 2).
According to such a method, interference fringes or the like are generated, and the metallic luster and texture can be sufficiently expressed. On the other hand, since the metal plate 90 is used for metal processing, the material and processing There was a problem that the cost for this would be very high. In addition, the relatively light-colored metal plate 90 such as aluminum has a problem that the texture cannot be obtained so much even if the groove processing is performed. In addition, in the metal plate 90 such as aluminum, the flat portion 91 and the groove portion 92 are the same color, so that the texture cannot be emphasized much even if the depth of the groove 92 is increased. On the other hand, changing the groove pitch on the same circumference in order to suppress interference fringes is very difficult on the principle of processing.
Further, usually, in a display panel such as a speed meter, a portion expressing a metal texture and a portion not expressing are mixed. It is very expensive to produce a part that expresses the texture of the metal using a single metal plate. Therefore, a certain amount of cost can be suppressed if each is constituted by separate parts. However, even in that case, there is a problem that the cost is still high.

In addition to the screen printing described above, there are inkjet printing and the like as a printing method. However, when printing on a substrate by normal inkjet printing, that is, water-based inkjet printing widely used in general households, a receiving layer for absorbing the water-based ink is required on the substrate. After ink jet printing, water-based ink soaked into the receiving layer, so that only a flat print layer could be formed, and an uneven layer such as a scratch pattern could not be formed.
Further, in the solvent-based inkjet, it is necessary to leave the ink for a long time before the ink is discharged and dried. At the time of drying, the ink on the substrate is flattened by its own weight, so that it is difficult to form a three-dimensional scratch pattern even in solvent-based inkjet printing. Thus, in inkjet printing, since a printing layer becomes flat, it was difficult to form a three-dimensional shape such as metal groove processing. For this reason, it has been difficult to express glossiness and texture of metal or the like by inkjet printing. Furthermore, it is difficult to obtain a three-dimensional printing layer in the same manner by other digital printing methods such as laser printing and thermal transfer printing.

JP 2003-4494 A JP 2003-4495 A

  The present invention has been made in view of such conventional problems, and is intended to provide a display panel that is inexpensive and can easily express the glossiness and texture of metal or the like and a method for manufacturing the display panel.

The first invention includes a transparent resin substrate having a thickness of 1 mm or less, a colored design layer formed on the resin substrate, and a design surface on which the design layer is formed on the design layer or the resin substrate. Is a display panel having a concavo-convex layer formed on the opposite surface, in which a plurality of concave and convex portions are alternately arranged,
The concavo-convex layer is obtained by printing and curing ultraviolet curable ink by inkjet printing so that the thickness of the convex portion is larger than the thickness of the concave portion,
The convex portion is in the display panel, characterized by comprising a number of fine lines in 5 0～200Myuemu width that will be formed by the inkjet printing form with 0～200Myuemu intervals (claim 1).

  In the display panel according to the first aspect of the present invention, the concavo-convex layer in which a plurality of the concave portions and the convex portions are alternately arranged is formed by the ink jet printing using the ultraviolet curable ink. Therefore, at the time of forming the concavo-convex layer, the ultraviolet curable ink can be cured by irradiating ultraviolet rays immediately after the ultraviolet curable ink of the ink jet printing has landed on the design layer or the resin substrate. . Therefore, the ultraviolet curable ink can be prevented from being flattened by its own weight after landing, and the convex portions can be easily formed by stacking the cured ultraviolet curable ink, for example. Therefore, the convex part with a large thickness can be easily formed, and the three-dimensional concave-convex layer can be formed.

Moreover, the said design layer and the said uneven | corrugated layer are formed in the said display panel. Therefore, in the display panel, for example, a scratch pattern or the like can be formed by the three-dimensional uneven layer, and a change in gloss or texture can be imparted to the color or pattern of the design layer. For example, by forming a metal color or woodgrain layer as the design layer, the display panel can obtain a glossy feeling or texture of metal or wood grain. That is, a three-dimensional groove processing of metal or the like can be reproduced in a pseudo manner. Furthermore, in ink jet printing, since one ink particle can be formed in units of several tens of μm, the pitch width, that is, the interval between the convex portions is made finer than screen printing or the like. Can do. Therefore, the display panel can more fully express the glossiness and texture of metal, for example.
Further, in the display panel, since the glossiness and texture of metal or the like can be expressed by the ink jet printing without performing metal processing or the like, the manufacturing cost of the display panel can be reduced.

  As described above, according to the first aspect of the present invention, it is possible to provide a display panel that is inexpensive and can easily express the glossiness and texture of metal or the like.

The second invention includes a transparent resin substrate having a thickness of 1 mm or less, a colored design layer formed on the resin substrate, and a design surface on which the design layer is formed on the design layer or the resin substrate. Is a method for manufacturing a display panel having a concave and convex layer formed on the opposite surface, wherein a plurality of concave and convex portions are alternately arranged,
A design layer forming step of forming the design layer by printing colored colored ink on the resin substrate;
Using an ink jet printing apparatus comprising at least an ink ejection unit that ejects an ultraviolet curable ink, an ultraviolet irradiation unit that incorporates an ultraviolet lamp, and a holding unit that holds the resin substrate as a substrate to be printed, on the design layer or A discharge operation for discharging the ultraviolet curable ink from the ink discharge portion on a surface opposite to the design surface on which the design layer is formed on the resin substrate, and the ultraviolet irradiation portion on the discharged ultraviolet curable ink. A concavo-convex layer forming step of forming the concavo-convex layer so that the thickness of the convex portion is larger than the thickness of the concave portion by repeatedly performing a curing operation of irradiating ultraviolet rays from the above and curing the ultraviolet curable ink. Have
In the concavo-convex layer forming step, the ultraviolet curable ink is ejected while moving the ink ejection part of the ink jet printing apparatus in one direction at 20 to 200 m per minute relative to the holding part, an operation of printing by ultraviolet irradiation, the holding portion by repeating the operation and to one pitch movement at right angles to said one direction relative to the ink discharge portion, a plurality of thin lines 5 0～200Myuemu width formed by 0~200μm intervals in a method of manufacturing a display panel, characterized by forming the protrusions (claim 19).

In the said 2nd invention, the display panel which has the said resin substrate, the said design layer, and the said uneven | corrugated layer is manufactured by performing the said design layer formation process and the said uneven | corrugated layer formation process.
In the design layer forming step, colored colored ink is printed on the resin substrate. Thereby, for example, the colored design layer such as a metal color is formed.
Moreover, in the said uneven | corrugated layer formation process, the said ink of the said inkjet printing apparatus is provided in the surface on the opposite side to the said design surface which forms the said design layer in the said design layer or the said resin substrate using the said inkjet printing apparatus. A discharge operation for discharging the ultraviolet curable ink from the discharge unit and a curing operation for irradiating the discharged ultraviolet curable ink with ultraviolet rays from the ultraviolet irradiation unit to cure the ultraviolet curable ink are repeated. At this time, the operation of discharging and curing the ultraviolet curable ink while moving the ink discharge portion of the ink jet printing apparatus in one direction at 20 to 200 m per minute relative to the holding portion, and the one direction The operation of moving the holding portion at a right angle by one pitch is repeated.

  Therefore, in the concavo-convex layer forming step, the ultraviolet curable ink can be cured by ultraviolet rays immediately after the ultraviolet curable ink of the ink jet printing has landed on the design layer or the resin substrate. That is, the ultraviolet curable ink can be cured before the ultraviolet curable ink is flattened by its own weight after landing and becomes thin. Therefore, the convex part having a large thickness can be easily formed by stacking ultraviolet curable inks, and the three-dimensional concave / convex layer can be formed.

Furthermore, in the uneven layer forming step, the uneven layer is formed by the ink jet printing. Therefore, one ink particle can be formed in units of several tens of μm, and the line pitch can be made finer than screen printing or the like. Therefore, the display panel can more fully express the glossiness and texture of metal, for example.
Further, in the display panel, since the glossiness and texture of metal or the like can be expressed by the ink jet printing without performing metal processing or the like, the manufacturing cost of the display panel can be reduced.

Next, a preferred embodiment of the present invention will be described.
The display panel can be used for, for example, a speed display panel for automobiles and a display panel for an air conditioner.
The display panel includes a resin substrate, a colored design layer formed on the resin substrate, and an uneven layer formed on the design layer or on the surface opposite to the design surface 21 on which the design layer is formed. And have.
An example of such a display panel is shown in FIG.
In the display panel 1, the uneven layer 4 is formed on a surface 22 opposite to the design surface 21 as shown in FIG. In this case, the glossiness peculiar to the resin substrate can be obtained when the display panel 1 is viewed from the uneven layer 4 side. Moreover, the said uneven | corrugated layer 4 can also be formed on the design layer 3 (refer FIG. 4).

The design layer can be formed by printing colored inks such as clear (transparent), black, white, magenta, cyan, yellow, light cyan, and light magenta. The design layer can be formed by printing one or more layers of colored ink.
Moreover, in the said design layer, when light is irradiated from the surface on the opposite side to the said uneven | corrugated layer of the said resin substrate, the permeation | transmission part which permeate | transmits light and the non-permeability | transmission part which does not permeate | transmit light can be formed. . The opaque portion can be formed by combining colors such as magenta, cyan, yellow, and black, or by printing a plurality of these colored design layers stacked.

At least a part of the design layer preferably contains one or more selected from metallic pigments, metal fine particles, and metal foils (Claim 2).
The design layer is composed of one or two or more colored layers, and at least one of the colored layers contains one or more selected from metallic pigments, metal particles, and metal foils. (Claim 3)
In these cases, metallic luster and texture can be imparted to at least part of the design layer. Therefore, in this case, by imparting a scratch pattern feeling to the concavo-convex layer 4, it is possible to enhance the metallic luster and texture of the design layer.

Further, on the design surface of the resin substrate, the surface 60 ° prescribed in JISK5600 - the decorative layer consisting of the metal colored layers via the glossiness 5 or more underprint layer is formed, 該意Takumi It is preferable that the uneven layer is formed on the layer .
An example of such a display board is shown in FIG.
That is, as shown in the figure, in the display panel 1, the base printed layer 35 having a surface of 60 degrees and a glossiness of 5 or more as defined in JISK5600 is formed on the design surface 21 of the resin substrate 2. The metal color layer 31 is laminated on the base print layer 35. Further, on the design layer 3 having at least the metal coloring layer 31, the concave / convex layer 4 in which a plurality of concave portions 42 and convex portions 41 are alternately arranged is formed.
In this case, taking advantage of the gloss of the underprint layer 35, the metal color layer 31 can exhibit a glossiness close to that obtained from a real metal. Further, since the uneven layer 4 is formed on the design layer 3 including the metal color layer 31, the gloss and texture that can be obtained by processing a flaw pattern on a real metal in a pseudo manner. Can be obtained.

The glossiness of the underprint layer can be measured by a method specified in JISK5600, specifically, a method according to the specular glossiness specified in JISK5600-4-7. A base print layer having a surface of 60 degrees and a glossiness of 5 or more indicates that the glossiness is 5 or more when the surface of the base print layer is irradiated with light from an angle of 60 °.
When the glossiness of the underprint layer is less than 5, the surface of the underprint layer becomes rough, which may reduce the glossiness of the metal color layer formed on the underprint layer. is there. The underprint layer may be colored or transparent.

Next, as the resin substrate, a substrate made of a thermoplastic resin such as polycarbonate or polyethylene terephthalate (PET) can be used.
Moreover, it is preferable to use a translucent resin substrate as the resin substrate.
In this case, for example, the display panel can be used as a backlight type display panel by irradiating the display panel with light from a light source disposed on the surface opposite to the surface on which the uneven layer is formed. More preferably, the resin substrate is made of a transparent resin substrate having a thickness of 1 mm or less . When the thickness exceeds 1 mm, for example, when the design layer is formed on the back surface opposite to the surface viewed by the user of the display panel, the design layer can be clearly seen. May be difficult. In addition, since the distance between the design layer and the concavo-convex layer becomes large, the design layer and the concavo-convex layer appear to be shifted from each other when viewed by a viewer, and the appearance may deteriorate.

Further, as described above, in the case where the resin substrate is made of a transparent resin substrate having a thickness of 1 mm or less, the resin substrate has a surface of 60 degrees-glossiness of 5 or more as defined in JISK5600 on the surface on the design surface side. has a mirror surface, and the design layer having upper Symbol metal colored layers are formed on the design surface, the uneven layer on the side opposite to the above design surface in the resin substrate is formed with said mirror surface (Claim 5 ).
An example is shown in FIG.
That is, as shown in the figure, in the display panel 1, the resin substrate 2 has a mirror surface 23 having a surface 60 degrees-glossiness 5 or more as defined in JISK5600 on the surface of the design surface 21, and on the mirror surface 23. The metal coloring layer 31 is formed. Further, the concave / convex layer 4 in which a plurality of concave portions 42 and convex portions 41 are alternately arranged is formed on the surface 22 of the resin substrate 2 opposite to the design surface 21.
In this case, taking advantage of the glossiness of the mirror surface 23, the metal color layer 31 can exhibit a glossiness close to that obtained from a real metal. Further, the uneven layer 4 is formed on the surface opposite to the design surface 21. Therefore, when the display panel 1 is viewed from the concave / convex layer 4 side, the metallic color layer 23 having an excellent gloss as described above can be viewed, and the concave / convex layer 4 allows the metal color to be visualized. A stereoscopic effect can be produced in the colored layer 23. Therefore, it is possible to obtain glossiness and texture that can be obtained by processing a scratch pattern on a real metal in a pseudo manner.
The glossiness of the mirror surface can be measured by the method defined in JISK5600, as in the case of the base printing layer. A mirror surface having a surface of 60 degrees and a glossiness of 5 or more indicates that the glossiness is 5 or more when the mirror surface is irradiated with light from an angle of 60 °.
When the glossiness is less than 5, the mirror surface is rough, and the glossiness of the metal color layer formed on the mirror surface may be reduced.

  Next, the concavo-convex layer is formed by ink-jet printing an ultraviolet curable ink. As the ultraviolet curable ink, for example, acrylic radical polymerization type and epoxy cationic polymerization type inks can be used.

Moreover, the uneven layer is preferably made of a transparent of the UV curable ink (claim 6).
In this case, without changing the color of the design layer, it is possible to give the design of the design layer a change in gloss and texture by the uneven layer.

In addition, the uneven layer is colored, from the ultraviolet curable ink of one or more colors selected from black, cyan, magenta, yellow, light black, light cyan, light magenta, light yellow, and white. (Claim 7 ).
In this case, since the color of the colored concavo-convex layer changes depending on the angle at which the design layer is visually recognized, more various textures can be given to the design of the design layer. Further, in the conventional metal processing, as described above, it was difficult to emphasize the glossiness and texture of a light-colored metal plate such as an aluminum plate. However, in the present invention, as described above, the colored UV-curing is performed. By forming the concavo-convex layer using the ink, it is possible to enhance the gloss and texture of the design layer made of aluminum.

Moreover, the thickness of the recess 42 in the uneven layer can be 0 μm.
That is, for example, as shown in FIG. 6, in the concavo-convex layer 4 in which a plurality of concave portions 42 and convex portions 42 are alternately arranged, only the convex portions 41 are formed by inkjet printing of the ultraviolet curable ink. Can be formed by providing a non-printing portion 425 that is not printed with ultraviolet curable ink.

Then, the uneven layer is preferably formed by inkjet printing over resolution 1200 DPI × 1200 DPI (claim 8).
In the case where the resolution of the uneven layer is less than 1200 DPI × 1200 DPI, there is a possibility that an arc curve having a diameter smaller than 100 mm, for example, cannot be expressed smoothly due to insufficient resolution.

Moreover, it is preferable that the thickness difference of the said recessed part and the said convex part is 1-300 micrometers (Claim 9 ).
The difference in thickness between the concave portion and the convex portion will be described with reference to FIG.
As shown in the figure, in the display panel 1, the concavo-convex layer 4 is formed by alternately arranging a plurality of concave portions 42 and convex portions 41. Due to the difference in thickness between the concave portion 42 and the concave portion 41, the concave-convex layer 4 can express a three-dimensional scratch pattern or the like.
When the thickness difference T between the concave portion 42 and the convex portion 41 is less than 1 μm, the three-dimensional effect of the concave-convex layer 4 becomes insufficient, and the design layer 3 has a sufficient gloss for patterns and colors such as metal and wood grain. There is a possibility that the feeling and texture cannot be imparted. On the other hand, when the thickness difference T exceeds 300 μm, the unevenness of the uneven layer 4 is excessively emphasized, and the design layer 3 of the display panel 1 may be difficult to visually recognize. More preferably, the thickness difference between the concave portion and the convex portion is 5 to 200 μm.

Moreover, it is preferable that the said uneven | corrugated layer forms many fine lines of 50-200 micrometers width at intervals of 0-200 micrometers by the said inkjet printing .
That is, for example, as shown in FIG. 6, the concavo-convex layer 4 is preferably formed by forming a large number of fine wires 43 with a width W = 50 to 200 μm at intervals D = 0 to 200 μm.
When the width W of the fine wire 43 is less than 50 μm, the fine wire 43 becomes so thin that it is difficult to recognize, for example, a metal scratch pattern formed by the uneven layer 4. On the other hand, when the width W exceeds 200 μm, the fine line 43 becomes too thick, and it may be difficult to realistically express, for example, a metal scratch pattern by the uneven layer 4. Moreover, when the space | interval D of the thin wires 43 exceeds 200 micrometers, there exists a possibility that a space | interval may become too wide and it may become difficult to express a metal scratch pattern etc. with the uneven | corrugated layer 4, for example. More preferably, the distance D between the thin wires 43 is 5 μm or less.

Further, the distance D between the thin lines may be zero.
That is, as shown in FIG. 7, two adjacent thin wires 43 may be in contact with each other. Also in this case, the convex portion 41 is formed at the top of the thin wire 43 and the concave portion 42 is formed between two adjacent convex portions 41.
The fine line 43 is formed by the ink jet printing. That is, the fine line 43 is formed by ejecting droplets of the ultraviolet curable ink onto the resin substrate 2 by the ink jet printing and curing the droplets. Therefore, as shown in FIG. 7, the cross section of the thin wire | line 43 is a substantially semicircle shape. Therefore, as described above, even if the distance D between the fine wires 43 is set to 0 and the adjacent fine wires 43 are partially in contact with each other, the convex portion 41 is formed on the top of the fine wire 43 and two adjacent fine wires 43 are formed. A recess 42 is formed at the contact portion 43. Therefore, also in this case, the uneven layer 4 in which the convex portions 41 and the concave portions 42 are alternately arranged can be formed.

The width W of the fine wire 43 refers to the maximum width of the fine wire 43 (see FIG. 6). As will be described later, even when a plurality of drawn lines 451, 452, and 453 having different widths are stacked to form the thin line 43 (see FIG. 9), the width W of the thin line refers to the maximum width.
On the other hand, the interval D between the fine wires 43 is the interval between adjacent fine wires 43, which is the minimum interval (see FIG. 6). As will be described later, even when a plurality of drawn lines 451, 452, and 453 having different widths are stacked to form the thin line 43 (see FIG. 9), the distance D between the thin lines 43 refers to the minimum distance.

Next, the fine line is preferably formed by laminating two or more drawn lines made of the ultraviolet curable ink formed by the ink jet printing in the thickness direction (claim 10 ).
An example in which fine lines are formed by drawn lines in the stacked state is shown in FIG.
That is, as shown in the figure, in the display panel 1, the fine lines 43 can be formed by laminating the drawn lines 457, 458, and 459. In the figure, a concavo-convex layer 4 in which a plurality of convex portions 41 and concave portions 42 composed of the thin wires 43 are arranged is formed on the resin substrate 2.
In this case, the thickness difference between the convex portion 41 and the concave portion 42 can be increased, and the three-dimensional uneven layer 4 can be formed.

Further, as shown in FIG. 9, the fine lines 43 are formed by laminating the drawn lines 451, 452, and 453 so that the width decreases as the distance from the resin substrate 2 increases in the stacking direction of the drawn lines 451, 452, and 453. (Claim 11 ).
That is, as shown in the figure, in the case where the thin line 43 is formed by laminating the drawn lines 451, 452, and 453, the resin substrate 2 extends in the stacking direction of the drawn lines 451, 452, and 453 (the thickness direction of the resin substrate 2). It is preferable that the widths of the drawn lines 451, 452, and 453 are gradually reduced as the distance increases. In the example shown in FIG. 9, the drawn line 452 is formed with a width smaller than the drawn line 451, and the drawn line 453 is formed with a width smaller than the drawn line 452.
In this case, the tip of the convex part 41 becomes sharp, and the effect of imparting a three-dimensional effect by the concave-convex layer 4 to the thickness of the fine wire 43 can be further emphasized. Even if the thickness of the fine wire 43 is increased without changing the width, the thickness difference between the convex portion 41 and the concave portion 42 becomes large and the concave / convex layer 4 can be emphasized. The amount of ink increases, and the manufacturing cost of the display panel 1 increases (see FIG. 8). On the other hand, as shown in FIG. 9, when the drawn lines 451, 452, and 453 are laminated so that the width gradually decreases from the lower layer to the upper layer in the stacking direction of the drawn lines 451, 452, and 453, the thickness of the thin line is increased. Even if it is not so large, the three-dimensional uneven layer 4 can be formed (see FIG. 9).

Further, of the drawn line in the stacked state, at least two of the drawn lines are preferably made of different colors the ultraviolet curable ink of each other (claim 12).
That is, for example, as shown in FIGS. 8 and 9, at least two of the drawn lines 451 (457), 452 (458), and 453 (459) formed in layers are different from each other in ultraviolet curable inks having different colors. Preferably it consists of. 8 and 9, drawn lines 451 (457), 452 (458), and 453 (459) of different colors are indicated by different hatchings.
In this case, the convex part 41 whose color changes in the thickness direction can be formed. Therefore, various glossiness and textures can be generated for the viewer depending on the viewing angle.

Moreover, it is preferable that the said drawn line of the uppermost layer consists of black or a black-type color in the said thin wire | line (Claim 13 ).
In this case, the peak portion (uppermost layer) of the convex portion is emphasized, and the three-dimensional effect of the uneven layer can be further enhanced. As a result, for example, it is possible to further emphasize a metal scratch pattern or the like.

Further, as described above, in the concavo-convex layer 4, the concave portion 42 can be formed by providing a non-printing portion 425 on which the ultraviolet curable ink is not printed (see FIGS. 6 and 8). For example, as shown in FIG. 10, it can also be formed by printing a drawn line 450 made of the ultraviolet curable ink with a thickness smaller than that of the convex portion 41.
In the example shown in FIG. 10, the convex portion 41 is formed by stacking three layers of drawn lines 457, 458, and 459. On the other hand, the recess 42 is composed of a single drawn line 450. Thus, the recessed part 42 can also be formed by printing ultraviolet curable ink.

Then, the uneven layer is preferably a plurality of the concave portions and a plurality of the convex part forms a concentric pattern consisting arranged concentrically alternately (claim 14).
In this case, interference fringes (moire) can be generated, and the above-described gloss and texture can be further emphasized.
An example of a concentric pattern (automobile speed meter) is shown in FIG. As shown in the figure, the concentric pattern can be expressed, for example, by forming a large number of concentric circles by convex portions 41 made of ultraviolet curable ink. Between the two adjacent convex portions 41, the concave portion 42 having a thickness smaller than the convex portion is formed.

Moreover, the concentric pattern consists of two concentric circles centered positions are different, the center distance is preferably 10 to 1000 [mu] m (Claim 15).
FIG. 11 shows an example of a concentric pattern (automobile speed meter) composed of two concentric circles with different center positions. As shown in the figure, the concavo-convex layer 4 is composed of two concentric circles 48 and 49 having different stopping positions. The concentric pattern in each of the concentric circles 48 and 49 can be formed by, for example, a large number of concentric circles by the convex portions 41 made of ultraviolet curable ink. Between the two adjacent convex portions 41, the concave portion 42 having a thickness smaller than that of the convex portion 41 is formed. The two concentric circles 48 and 49 have centers O ₁ and O ₂ , respectively, and the center distance d between the center O ₁ and the center O ₂ is 10 to 1000 μm. In this case, the interference fringes can be further emphasized by the two concentric circles, and the above-described glossiness and texture can be further enhanced.
If the center distance d is less than 10 μm, the interference fringe enhancement effect may not be sufficiently obtained. On the other hand, when the thickness exceeds 1000 μm, the effect of enhancing the interference fringes becomes excessive, which may cause discomfort to the viewer.

Moreover, it is preferable that the said uneven | corrugated layer forms the hairline pattern by which several linear said recessed part and several linear said convex part are distribute | arranged alternately (Claim 16 ).
Also in this case, as in the case of the concentric pattern, interference fringes can be generated, and the above-described glossiness and texture can be further emphasized. Further, when a woodgrain design layer is formed as the design layer, a more natural wood texture can be produced in the design layer by the uneven layer of the hairline pattern.
An example of a hairline pattern (automobile speed meter) is shown in FIG. As shown in the figure, the hairline pattern can be expressed by forming, for example, a large number of parallel straight lines (thin lines) by the convex portions 41 made of ultraviolet curable ink. A concave portion 42 having a thickness smaller than that of the convex portion 41 is formed between two adjacent convex portions 41. At this time, in many straight lines (thin line 43) which form the convex part 41, the length and width | variety can be changed suitably.

Moreover, it is preferable that the said uneven | corrugated layer forms the Asahi light weight pattern in which the said several convex part is distribute | arranged radially from the substantially same center part or this center part (Claim 17 ).
Also in this case, like the concentric pattern and the hairline pattern, interference fringes (moire) can be generated, and the above-described glossiness and texture can be further emphasized. Moreover, a three-dimensional feeling can be given to the design of the said design layer.
FIG. 13 shows an example of a display panel with an Asahi light weight pattern (automobile speed meter). As shown in the figure, the Asahi light weight pattern can be expressed, for example, by forming a large number of radial lines from the vicinity of the center of the circle to the outside by the convex portions 41 made of ultraviolet curable ink. A concave portion 42 having a thickness smaller than that of the convex portion is formed between two adjacent convex portions 41.

Moreover, it is preferable that the said uneven | corrugated layer forms the tangerine pattern.
An example of a mandarin orange pattern is shown in FIG. As shown in the figure, the citrus pattern includes a plurality of fan-shaped patterns 47 arranged clockwise or counterclockwise. In the fan-shaped pattern 47, the convex portions 41 made of an arc-shaped curve and the concave portions 42 made of an arc-shaped curve are alternately arranged, and the length of the arc-shaped curve is outside the center of the fan-shaped pattern 47. It is getting bigger toward the direction.
By forming such a citrus pattern, interference fringes (moire) can be generated, and the above-described glossiness and texture can be further emphasized.

Moreover, in the fan-shaped pattern, it is preferable that the arc-shaped curve has a gradually decreasing curvature from the center of the fan-shaped pattern to the outside. That is, for example, in the citrus pattern shown in FIG. 14, the arc-shaped curve of the convex portion 41 constituting the fan-shaped pattern 47 has a curvature that increases as it approaches the center P1 of the fan-shaped pattern, and decreases as it moves away from the center P1. ing.
In this case, irregular reflection of external light can be generated, and further texture can be imparted.

Further, as shown in FIG. 15, the citrus pattern is preferably formed by arranging a plurality of fan-shaped patterns 47 having different central angles θ clockwise or counterclockwise.
In this case, the designability of the display panel 1 can be improved. Further, since the amount of reflected light changes in each area of each fan-shaped pattern 47, for example, when the display panel 1 is used as a speedometer of an automobile, how the board surface is seen according to the area indicated by the speedometer pointer (Reflection zone) changes. Therefore, the quick reading property of the speed meter by the viewer (driver) can be improved. FIG. 15 shows an example of the above-mentioned citrus pattern in which the fan-shaped patterns 47 are arranged so that the central angle θ increases in the clockwise direction, and θ ₁ <θ ₂ is satisfied. The central angle θ of the fan-shaped pattern is the central angle of the fan shape when the outer shape of the fan-shaped pattern is regarded as a fan shape.

Further, as shown in FIG. 16, in the citrus pattern, the plurality of fan-shaped patterns 47 can be arranged clockwise or counterclockwise while shifting the center position P thereof. The center position P of the fan-shaped pattern 47 is the center when the outer shape of the fan-shaped pattern 47 is regarded as a fan shape. As shown in the figure, for example, the center position P ₂ of the center position P ₁ and the fan-shaped pattern 472 of the fan-shaped pattern 471 is not matched.
In this case, it is possible to express surface halation that cannot be expressed by a concentric pattern or the like. That is, in general, the reflectance and refractive index are greatly influenced by the curvature of the concavo-convex layer. However, since the curvature is almost determined by the size of the display board in a certain concentric circle, the texture of the concentric circle pattern or the like can only be controlled by the line spacing, thickness, height, and the like. On the other hand, in the above-mentioned citrus pattern, the curvature of the circle can be divided by each fan-like pattern, so that more various textures can be expressed.

Further, it is preferable that at least a part of the resin substrate has a three-dimensional shape by vacuum molding or pressure molding (claim 18 ).
In this case, since the three-dimensional shape such as a gentle curved surface is formed on the display board, the reflection of external light becomes remarkable and the texture can be further enhanced.

Next, when manufacturing the said display panel, the said design layer formation process and the said uneven | corrugated layer formation process are performed.
In the design layer forming step, the design layer is formed by printing colored colored ink on the resin substrate.
In the concavo-convex layer forming step, an ink jet printing apparatus including at least an ink ejection unit that ejects an ultraviolet curable ink, an ultraviolet irradiation unit that incorporates an ultraviolet lamp, and a holding unit that holds the resin substrate as a printed material. A discharge operation for discharging the ultraviolet curable ink from the ink discharge portion onto the design layer or a surface opposite to the design surface on which the design layer is formed on the resin substrate, and the discharged ultraviolet light. The concavo-convex layer is formed such that the thickness of the convex portion is larger than the thickness of the concave portion by repeatedly performing a curing operation of irradiating the curable ink with ultraviolet rays from the ultraviolet irradiation portion and curing the ultraviolet curable ink. Form.

  As the ink jet printing apparatus, for example, as shown in FIG. 17, at least an ink ejection unit 51 that ejects an ultraviolet curable ink, an ultraviolet irradiation unit 52 that incorporates an ultraviolet lamp, and a substrate (resin substrate) 2 are held. The ink jet printing apparatus 5 having the holding unit 53 can be used. In the ink jet printing apparatus 5 shown in the figure, the ink ejection unit 51 and the ultraviolet irradiation unit 52 are linearly reciprocated in one direction A by the first driving unit 54, while the holding unit 53 is in the one direction A The second drive unit 55 is configured to reciprocate linearly in a direction B perpendicular to the direction.

In the concavo-convex layer forming step, ultraviolet curable ink is ejected while moving the ink ejection part 51 of the inkjet printing apparatus 5 in one direction A at a rate of 20 to 200 m per minute relative to the holding part 53. The concavo-convex layer 4 is formed by repeating the operation of irradiating and printing and the operation of moving the holding portion 53 by one pitch perpendicular to the one direction A with respect to the ink discharge portion 51 (see FIG. 17).
When the moving speed of the ink discharge portion is less than 20 m / min, the droplets of the ultraviolet curable ink discharged from the ink discharge portion are liable to be crushed, thereby forming the three-dimensional concavo-convex layer. There is a risk that it will not be possible. On the other hand, if it exceeds 200 m / min, the ink ejected from the ink ejecting part may be scattered due to the turbulent air flow generated by the movement of the ink ejecting part 51, and the ink landing accuracy may be lowered. There is. Therefore, it may be difficult to form the uneven layer in a desired shape.

In the above design layer forming process, at least a portion of the design layer, metallic pigments, metal particles, and is preferably formed by the color ink containing one or more selected from a metal foil (claim 20 ).
Moreover, in the said design layer formation process, while forming the said design layer which consists of a colored layer of 1 layer or 2 layers or more by stacking and printing the said colored ink 1 layer or 2 layers or more, among the at least one layer, by the colored ink containing a metallic pigment and / or metal particles, it is preferable to form the metal colored layers (claim 21).
In these cases, the metallic design layer can be formed. By forming, for example, a scratch pattern or the like with the concave and convex layer, the metallic gloss and texture of the decorative layer can be enhanced. .

In the design layer forming step, an underprint layer having a surface of 60 degrees-glossiness of 5 or more as defined in JISK5600 is formed on the design surface of the resin substrate, and the metal color layer is formed on the underprint layer. And in the said uneven | corrugated layer formation process, it is preferable to form the said uneven | corrugated layer on the said design layer (Claim 22 ).
In this case, the metallic color coloring layer having a glossiness close to the glossiness obtained from a real metal can be formed by taking advantage of the glossiness of the base printing layer. Furthermore, since the concavo-convex layer is formed on the design layer including the metal-colored colored layer, the glossy and textured texture obtained by processing a scratch pattern on a real metal in a pseudo manner A display board can be manufactured. As described above, the glossiness of the underprint layer can be measured by the method defined in JISK5600, specifically, JISK5600-4-7. When the glossiness is less than 5, the surface of the underprint layer becomes rough, and the glossiness of the metal color layer formed on the underprint layer may be reduced.
The base printing layer can be formed by ink jet printing, gravure printing, or the like. The underprint layer may be colored or colorless (transparent). Although the said base printing layer can be formed as a part of said design layer, it can also be formed as a printing layer different from the said design layer.

Next, it is preferable to use a transparent resin substrate having a thickness of 1 mm or less as the resin substrate .
In this case, even if the concavo-convex layer and the design layer are respectively formed on the opposite surface of the resin substrate, the viewer who observed the display panel from the concavo-convex layer side changed the design layer on the opposite side. Visible clearly.

Further, as the resin substrate, a resin substrate having a mirror surface with a surface of 60 degrees-glossiness of 5 or higher as defined in JISK5600 on the surface of the design surface is used. In the design layer forming step, the mirror surface of the resin substrate is used. It is preferable that at least the metal color layer is formed thereon, and in the uneven layer forming step, the uneven layer is formed on the surface of the resin substrate opposite to the design surface (claim 23 ).
In this case, the display panel capable of exhibiting a glossiness close to that obtained from a real metal can be manufactured by utilizing the glossiness of the mirror surface. Furthermore, the uneven layer is formed on the surface opposite to the design surface, that is, the surface opposite to the surface on which the design layer is formed. Therefore, when the display panel is viewed from the concave / convex layer side, the metallic color coloring layer having excellent gloss as described above can be visually recognized, and the concave / convex layer allows the metallic color coloring layer to be three-dimensional. A feeling can be produced. As a result, the display panel can exhibit a glossy feeling and texture that can be obtained by processing a scratch pattern on a real metal in a pseudo manner.
The glossiness of the mirror surface can be measured by a method defined in JISK5600. When the glossiness is less than 5, the mirror surface is rough, so that the glossiness of the metal color layer formed on the mirror surface may be reduced.

In the uneven layer forming step, droplets of the UV curable ink from the ink discharge portion, it is preferable to eject the following volumes 20pL per one droplet (claim 24).
When the volume per droplet exceeds 20 pL, the droplets of the ultraviolet curable ink ejected from the ink ejection portion are liable to be crushed, making it difficult to form the concavo-convex layer having a three-dimensional effect. There is a risk. More preferably, the volume per droplet is 10 pL or less.

In the uneven layer forming step is preferably formed by ultraviolet-curable ink transparent the uneven layer (claim 25).
In this case, it is possible to form the concavo-convex layer that gives the design of the design layer a change in glossiness and a texture without changing the color of the design layer.

In the concavo-convex layer forming step, the concavo-convex layer is formed of an ultraviolet curable ink having one or more colors selected from black, cyan, magenta, yellow, light black, light cyan, light magenta, light yellow, and white. (Claim 26 ).
In this case, since the color of the colored concavo-convex layer changes depending on the angle at which the design layer is viewed, various textures can be given to the design of the design layer. Further, in the conventional metal processing, as described above, it was difficult to emphasize the glossiness and texture of a light-colored metal plate such as an aluminum plate. However, in the present invention, as described above, the colored ultraviolet rays described above are used. By forming the concavo-convex layer using a curable ink, it is possible to enhance the gloss and texture of the design layer made of aluminum.

In the uneven layer forming step, it is preferable that the thickness difference between the concave portions and the convex portions forming the uneven layer so as to be 1 to 300 [mu] m (Claim 27).
When the thickness difference between the concave portion and the convex portion is less than 1 μm, the three-dimensional effect of the concave-convex layer becomes insufficient, and the gloss and the pattern and color of the design layer such as metal and woodgrain are sufficient. There is a risk that the texture cannot be applied. On the other hand, when the thickness exceeds 300 μm, the unevenness of the uneven layer is excessively emphasized, and the design layer of the display panel may be difficult to visually recognize. More preferably, the thickness difference between the concave portion and the convex portion is 5 to 200 μm.

In the concavo-convex layer forming step, the concavo-convex layer is preferably formed by forming a large number of fine lines having a width of 50 to 200 μm at intervals of 0 to 200 μm by the ink jet printing .
If the width of the fine line is less than 50 μm, the fine line becomes too thin and it may be difficult to recognize, for example, a metal scratch pattern formed by the uneven layer. On the other hand, when the width exceeds 200 μm, the fine line becomes too thick, and it may be difficult to realistically express, for example, a metal scratch pattern by the uneven layer. Moreover, when the space | interval of the said fine wire exceeds 200 micrometers, there exists a possibility that it may become difficult to express a metal scratch pattern etc. with the said uneven | corrugated layer because the space | interval is too wide. More preferably, the distance between the thin wires is 5 μm or less.

In the step of forming the concavo-convex layer, it is preferable to form the fine line by forming a drawn line made of the ultraviolet curable ink by the inkjet printing and printing the drawn line by stacking two or more layers in the thickness direction. (Claim 28 ).
In this case, the difference between the convex portion and the concave portion can be increased, and the three-dimensional uneven layer can be formed.

Further, in forming a stack of said drawn lines, in the stacking direction, it is preferable to stack the drawn line of smaller width with increasing distance from the resin substrate (claim 29).
In this case, it is possible to form a thin line whose width gradually decreases in the direction away from the resin substrate in the stacking direction (the thickness direction of the resin substrate). Therefore, in this case, the convex portion having a sharp tip can be formed. Therefore, it is possible to further emphasize the effect of providing a three-dimensional effect by the uneven layer with respect to the thickness of the thin line.
In the step of forming the concavo-convex layer, the fine line is formed by stacking and printing the drawn lines while making the drawn line width lower than the lower drawn line width when printing the stacked drawn lines. Can do. For example, in FIG. 9 described above, a cross-sectional view of a thin line formed by stacking three layers of drawn lines 451, 452, and 453 is shown. In FIG. 9, the drawn line 452 has a smaller width than the lower drawn line 451. They are stacked. Further, the drawn line 453 is formed to have a smaller width than the lower drawn line 452.

Further, of the drawn lines to be formed in a stacked state, it is preferable to form at least two or more of the drawn lines with different colors the ultraviolet curable ink (claim 30).
In this case, the convex portion whose color changes in the thickness direction can be formed. Therefore, it is possible to manufacture the display panel that gives the viewer a variety of glossiness and texture depending on the viewing angle.

Among the drawn lines to be formed in a stacked state, the top layer of the drawn lines are preferably formed by the ultraviolet curable ink comprising a black or blackish color (Claim 31).
In this case, the thin line whose uppermost layer is made of black or black can be formed. And in this case, the peak part (uppermost layer) of the said convex part in the said uneven | corrugated layer is emphasized, and the three-dimensional effect of the said uneven | corrugated layer can be emphasized further. As a result, for example, it is possible to further emphasize a metal scratch pattern or the like.

Moreover, in the said uneven | corrugated layer formation process, it is preferable to form the said uneven | corrugated layer of the concentric pattern by which several said recessed part and several said convex part are distribute | arranged alternately concentrically (Claim 32 ).
In this case, interference fringes (moire) can be generated, and the display panel with the above-described glossiness and texture more emphasized can be manufactured (see FIG. 1 described above).

Next, the concentric pattern consists of two concentric circles centered positions are different, the center distance is preferably 10 to 1000 [mu] m (Claim 33).
In this case, it is possible to form the concavo-convex layer capable of further enhancing the interference fringes (moire) by two concentric circles. Therefore, it is possible to manufacture the display panel in which the gloss and texture described above are further emphasized (see FIG. 11 described above).

Moreover, in the said uneven | corrugated layer formation process, it is preferable to form the said uneven | corrugated layer of the hairline pattern in which several linear said recessed part and several linear said convex part are distribute | arranged alternately (Claim 34 ). ).
Also in this case, interference fringes (moire) can be generated, and the display panel with the above-described glossiness and texture more emphasized can be manufactured. Further, in the case where a woodgrain-like design layer is formed as the design layer, the display panel having a more natural wood texture is manufactured by forming the uneven layer of the hairline pattern. (See FIG. 12 above). Moreover, when forming the said linear convex part, the line | wire width and space | interval can be changed suitably and can be formed.

Further, in the concavo-convex layer forming step, it is preferable to form the concavo-convex layer having an Asahi light weight pattern in which a plurality of the convex portions are arranged radially from substantially the same central portion or the vicinity of the central portion. 35 ).
Also in this case, interference fringes (moire) can be generated, and the display panel with the above-described glossiness and texture more emphasized can be manufactured (see FIG. 13 described above). In this case, a three-dimensional effect can be imparted to the design properties of the design layer.

Moreover, in the said uneven | corrugated layer formation process, it is preferable to form the mandarin orange pattern formed by arrange | positioning the above-mentioned fan-shaped pattern clockwise or counterclockwise. As described above, the fan-shaped pattern is formed by alternately arranging the convex portion made of an arc-shaped curve and the concave portion made of an arc-shaped curve, and the length of the arc-shaped curve is outward from the center of the fan-shaped pattern. The arcuate curved lines are arranged so as to gradually increase toward (see FIG. 14 described above).
Also in this case, interference fringes can be generated, and the display panel with enhanced gloss and texture can be manufactured.

Further, in the step of forming the concavo-convex layer, when forming the concavo-convex layer of the citrus pattern, the curvature of the arc-shaped curve of the fan-shaped pattern is gradually decreased from the center of the fan-shaped pattern to the outside. It is preferable to form such that (see FIG. 14).
In this case, irregular reflection of external light can be generated in the concavo-convex layer, and further texture can be imparted.

Further, in the step of forming the concavo-convex layer, when forming the concavo-convex layer of the citrus pattern, it may be formed by arranging a plurality of fan-shaped patterns with different central angles θ clockwise or counterclockwise. Preferred (see FIG. 15 above).
In this case, it is possible to form the concavo-convex layer in which the light reflection amount in each area of the fan-shaped pattern is changed, and it is possible to manufacture a display panel suitable for an automobile speedometer or the like as described above.
FIG. 15 shows an example of the citrus pattern in which the fan-shaped pattern 48 is arranged so that the central angle θ increases in the clockwise direction, and θ ₁ <θ ₂ in the figure.

Moreover, when forming the said uneven | corrugated layer of the said citrus pattern, the said some fan-shaped pattern can be arrange | positioned clockwise or counterclockwise, shifting the center position P (refer above-mentioned FIG. 16).
In this case, in addition to the curvature of the line, the width of the fan-shaped pattern and the radial distance of the fan-shaped pattern from the center point can be changed. Therefore, for example, in applications such as an automobile speed meter, the amount of halation can be changed on the surface when light is dropped from the pointer onto the display panel surface. Specifically, it is possible to give a function of suppressing halation in the safe driving speed indicator area and enlarging the halation area in order to alert the driver when the speed becomes high.

  In general, when the display panel is used, for example, in a speedometer of an automobile, the mounting position of the display board changes depending on the type of automobile to be mounted. In the present invention, as described above, in the uneven layer forming step, the ink jet printing can be performed by changing the resolution or the like, for example, in accordance with a viewing angle from a viewer such as a driver. Therefore, it is possible to easily form an optimal interference fringe generation pattern.

Printing in the uneven layer forming step is preferably carried out at a resolution 1200 DPI × 1200 DPI or higher (claim 36).
When the resolution is less than 1200 DPI × 1200 DPI, there is a possibility that, for example, an arc curve having a diameter smaller than 100 mm cannot be smoothly expressed due to insufficient resolution.

In the above uneven layer forming step, in a moving direction of the moving direction and the holding portion of the ink discharge portion, it is preferable to perform the ink jet printing at different resolutions (claim 37).
In this case, the interference fringe generation pattern can be changed.
Specifically, when the display panel is used for, for example, a car dial or the like, the mounting position varies depending on the type of the car, and the viewing angle from the driver may change. When ink jet printing is performed at different resolutions as described above, the interference fringe generation pattern can be changed, so that the optimum interference fringe generation pattern can be adjusted.

In the display panel manufacturing method, in addition to the design layer forming step and the concavo-convex layer forming step, a forming step of applying a three-dimensional shape to at least a part of the resin substrate by vacuum forming or pressure forming is performed. (Claim 38 ).
In this case, the three-dimensional shape such as a gentle curved surface can be formed on the display board. Therefore, it is possible to manufacture the display panel that is remarkably reflected from outside light and has a more excellent texture.
The forming step can be performed before or after the design layer forming step and the uneven layer forming step. Moreover, it can also carry out between the said design layer formation process and the said uneven | corrugated layer formation process, or in the middle of these processes.

Example 1
Next, an embodiment of the display panel according to the present invention will be described with reference to FIG. 1, FIG. 2, and FIG.
As shown in FIGS. 1 and 2, the display panel 1 of this example includes a resin substrate 2, a colored design layer 3 formed thereon, and a design surface 21 on which the design layer 3 of the resin substrate 2 is formed. Has an uneven layer 4 formed on the opposite surface 22 and having a plurality of recesses 42 and protrusions 41 arranged alternately. The concavo-convex layer 4 is obtained by printing and curing a droplet of ultraviolet curable ink by ink jet printing so that the thickness of the convex portion 41 is larger than the thickness of the concave portion 42.

The display board 1 of this example is a speedometer for automobiles. FIG. 1 shows a front view of the display panel 1 of this example, and FIG. 2 shows a partial cross-sectional enlarged view of the display panel 1.
As shown in FIG. 2, in the display panel of this example, the design layer 3 and the concavo-convex layer 4 are respectively formed on two opposing surfaces 21 and 22 on the transparent resin substrate 2 made of polycarbonate resin. .
A light source 15 such as an LED can be disposed on the side of the design surface 21 on which the design layer 3 is formed. In this example, the design layer 3 includes a metal color layer 31 formed of a metal color ink made of a metallic pigment containing aluminum powder or the like, and a black color layer 32 formed of a black color ink. And a white colored layer 33 made of translucent white colored ink. The metal coloring layer 31 can also be formed by a water-based ink containing metal fine particles and a transparent ink that protects the water-based ink.

  As described above, by forming the three colored layers 31, 32, and 33, in the display panel 1 of this example, the translucent portion 18 that transmits visible light and the opaque portion 19 that does not transmit visible light. Is formed. Since the transmission part 18 can transmit the light generated from the light source 15, the display panel 1 can be used as a backlight type display panel. Further, the non-transmissive portion 19 constituted by the black colored layer hardly transmits the light of the light source 15 and expresses the scale on the display panel 1 and the outline of the characters (see FIG. 1).

  As shown in FIG. 2, the transparent uneven layer 4 is formed on the surface 22 opposite to the design surface 21 side where the metal color layer 31 is formed in the portion where the metal color layer 31 is formed. ing. The concavo-convex layer 4 has a concentric pattern in which a plurality of concave portions 42 and a plurality of convex portions 41 are alternately arranged concentrically. Interference fringes are generated by the concentric pattern of the concavo-convex layer 4, and a driver who visually recognizes the metal color layer 31 can express the gloss and texture of the metal.

  Moreover, the uneven | corrugated layer 4 forms the concentric pattern in which the some recessed part 42 and the some convex part 41 are alternately arrange | positioned concentrically (refer FIG. 1). As shown in FIG. 2, in the concavo-convex layer 4, the convex portion 41 is formed of a transparent ultraviolet curable ink (hereinafter referred to as “UV ink” as appropriate), and the concave portion 42 is not printed with UV ink. The non-printing portion 425 is provided. In this example, the convex part 41 is formed with a thickness of 50 μm and a printing line width of 100 μm, and a concentric pattern is formed in which the distance between the printing lines between the convex part 41 and the convex part 41 is 200 μm.

Next, the manufacturing method of the display panel of this example will be described.
In the manufacturing method of the display panel 1 of this example, the design layer forming step and the uneven layer forming step are performed.
In the design layer forming step, the design layer 3 is formed by printing colored colored ink on the resin substrate 2. Moreover, in the uneven | corrugated layer formation process, the discharge operation | movement which discharges an ultraviolet curable ink to the surface 22 on the opposite side to the design surface 21 which forms the design layer 3 in the resin substrate 2 using an inkjet printer is discharged. The curing operation of irradiating the ultraviolet curable ink with ultraviolet rays and curing the ultraviolet curable ink is repeated. Thereby, the concavo-convex layer 4 is formed so that the thickness of the convex portion 41 is larger than the thickness of the concave portion 42.

  In this example, as shown in FIG. 17, at least an ink discharge unit 51 that discharges an ultraviolet curable ink, an ultraviolet irradiation unit 52 that incorporates an ultraviolet lamp, and a holding unit 53 that holds a resin substrate 2 as a substrate to be printed. Inkjet printing is performed using an inkjet printing apparatus 5 comprising: In the ink jet printing apparatus 5 shown in the figure, the ink ejection unit 51 and the ultraviolet irradiation unit 52 are linearly reciprocated in one direction A by the first driving unit 54, while the holding unit 53 is in the one direction A The second drive unit 55 is configured to reciprocate linearly in a direction B perpendicular to the direction.

  In the concavo-convex layer forming step, ultraviolet curable ink is ejected while moving the ink ejection part 51 of the inkjet printing apparatus 5 in one direction A at a rate of 20 to 200 m per minute relative to the holding part 53. The uneven layer is formed by repeating the operation of irradiating and printing and the operation of moving the holding portion 53 by one pitch in the direction B substantially perpendicular to the one direction A with respect to the ink ejection portion 51.

Hereinafter, the manufacturing method of the display panel of this example will be described in detail with reference to FIGS.
First, a transparent resin substrate 2 made of polycarbonate resin was prepared (see FIG. 2). On the design surface 21 of the resin substrate 2, a metal color layer 31 was printed and formed by screen printing using a colored ink made of a metallic pigment. Similarly, a black colored layer 32 was formed using a black colored ink by screen printing, and a translucent white colored layer 33 was sequentially laminated using a white colored ink. In this way, the design layer 3 composed of three types of layers, that is, the metal color layer 31, the black tail color layer 32, and the white color layer 33 was formed. In the design layer 3, the black colored layer 7 was printed on the opaque portion 19 representing the scale and the outline of the characters (see FIGS. 1 and 2). Moreover, the translucent white colored layer 33 was printed from the black ink layer 7 so that the whole design surface 21 of the resin substrate 2 might be covered. In this example, the metal color layer 31 is formed by printing the color ink composed of the metallic pigment as described above. However, the water-based ink containing the metal fine particles is printed, and this is applied to the print layer. It can also be formed by laminating and printing a transparent ink to be protected.

Next, the uneven layer 4 is formed on the surface 22 of the resin substrate 2 opposite to the design surface 21.
In the printing of the concavo-convex layer 4, a pattern (concentric pattern) is created by a computer, and an image is printed on the resin substrate 2 by an inkjet method using UV ink based on the created image.
In creating the image of this example, for example, image processing software manufactured by Adobe was used. Further, as the ink jet printing apparatus 5, specifically, a UV curable ink jet apparatus (Toshiba tech ink jet head, UV irradiation light source simultaneous drive type MIMAKI ENGINEERING UJF605C, maximum resolution: 2400 DPI, number of mounted heads: 8 heads) is used. (See FIG. 17). This printing machine 5 is equipped with an ultraviolet irradiation unit 52 containing a light source that performs ultraviolet irradiation directly beside an ink discharge unit (inkjet head) 51, and after ejecting ink droplets from the nozzles of the ink discharge unit 51, The ejected ink droplet can be immediately irradiated with ultraviolet rays.
In this example, the time from the ejection of the ink droplets from the nozzles of the ink ejection part 51 to the irradiation of the ultraviolet rays is set to within 1 second, for example, and the moving speed of the ink ejection part 51 is set to 20 m / min or more.

In addition, the ink ejection unit 51 does not print an image with a target resolution by, for example, ejecting ink once, but ejects ink to the same part a plurality of times by a head reciprocating, etc. Is to be printed. For example, when the resolution of the head is 150 DPI, an image of 1200 DPI can be obtained when the head ejects ink eight times (8 pushes).
In this specification, printing is performed once until an image having a target resolution is obtained. That is, when printing a 1200 DPI image, if the head resolution is, for example, 150 DPI, printing is performed once when ink is ejected eight times, and if the head resolution is 1200 DPI, ink is ejected once. This is a single print.

Specifically, first, an image was created by a computer, and then the image data was input to the inkjet printing apparatus 5. At this time, the printing resolution, the appropriate amount of ink, and the printing density per unit area (ink droplet ejection density) are designated. In this example, the resolution was specified as 1200 dpi, the appropriate amount of ink was 6 pl (picoliter), and the printing density was specified as 100%.
Next, by using the inkjet printing apparatus 5 to which the image data is input, the convex portion 41 of the concave-convex layer 4 with respect to the region of the metallic color coloring layer 31 formed on the design surface 21 side on the surface 22 of the resin substrate 2. Is printed (see FIGS. 1, 2, and 17). In this example, since a printing layer (convex portion 41) having an ink thickness of 3 to 10 μm is formed by one printing using a single head, the convex portion 41 having a thickness of 50 μm is obtained by performing printing a plurality of times. Formed. In addition, for example, by performing printing using a plurality of heads at the same time, the thick convex portion 41 can be formed in a short time. In addition, by increasing the head moving speed to 40 to 100 m / min and instantaneously curing the ink droplets that have landed on the resin substrate 2 to increase the ink thickness, it is possible to shorten the time for forming the convex portions 41. .

Thus, the some convex part 41 was printed concentrically. Thereby, the recessed part 42 which is not printed is formed between the two adjacent convex parts 41, and the uneven | corrugated layer 4 which arranges a recessed part and a convex part alternately is formed, and the design layer 3 and A display panel 1 having an uneven layer 4 was produced.
The manufactured display panel 1 is housed in a housing formed of a casing and a facing plate together with a pointer, a rotating inner unit, a light source, and the like (not shown), thereby completing a vehicle instrument.

  In the above-described embodiment, the case where an instrument panel of a vehicle instrument is manufactured as the display panel 1 has been described as an example. However, the present invention can also be applied to manufacture of a display panel having a metallic tone in other fields. it can. For example, in the field of home appliances, the present invention can be applied to a display panel that transmits light from a light emitting diode such as a touch panel.

The front view of the display panel concerning Example 1. FIG. The partial cross-sectional enlarged view of the display panel concerning Example 1 (partial cross-sectional enlarged view of FIG. 1). Explanatory drawing which shows the display panel which each has a design layer and an uneven | corrugated layer in the two surfaces which a resin substrate opposes. The partial cross-section enlarged view of the display panel which has the design layer formed on the base printed layer. The partial cross-section enlarged view of the display panel which has the design layer formed on the mirror surface of the resin substrate. The partial cross-section enlarged view of the display board which has an uneven | corrugated layer which formed the recessed part by forming a non-printing part. The partial cross-section enlarged view of the display board which has an uneven | corrugated layer formed by making several thin wires contact by inkjet printing. The partial cross-section enlarged view of the display panel which has the uneven | corrugated layer which formed the convex part with the thin line formed by laminating | stacking a several drawing line. The partial cross-section enlarged view of the display board which has an uneven | corrugated layer which forms a convex part by the thin wire | line which laminated | stacked several drawing lines so that the width of a drawing line may become small as it leaves | separates from a resin substrate in the lamination direction. The partial cross-section enlarged view which has the uneven | corrugated layer which formed the recessed part by printing the ultraviolet curable ink with thickness smaller than a convex part. The front view of the display panel in which the uneven | corrugated layer of two concentric patterns from which a center differs was formed. The front view of the display panel in which the uneven | corrugated layer of the hairline pattern was formed. The front view of the display board in which the uneven | corrugated layer of the Asahi light basis weight pattern was formed. The front view of the display panel in which the concavo-convex layer of the mandarin orange pattern was formed. The front view of the display panel in which the concavo-convex layer of the mandarin orange pattern which consists of several fan-shaped patterns from which a central angle differs is formed. The front view of the display panel in which the concavo-convex layer of the mandarin orange pattern formed by shifting a central position and arranging a plurality of fan-like patterns was formed. 1 is a perspective view showing a schematic overall configuration of a UV curable ink jet apparatus. Explanatory drawing which shows the display panel which has a flaw pattern layer formed by screen printing. Explanatory drawing which shows the display panel which has the groove part formed in the metal plate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Display panel 2 Resin substrate 21 Design surface 3 Design layer 4 Uneven layer 41 Convex part 42 Concave part

Claims (38)

A transparent resin substrate having a thickness of 1 mm or less, a colored design layer formed on the resin substrate, and a surface opposite to the design surface on which the design layer is formed on the design layer or the resin substrate A display panel having a concavo-convex layer formed by alternately forming a plurality of concave and convex portions,
The concavo-convex layer is obtained by printing and curing ultraviolet curable ink by inkjet printing so that the thickness of the convex portion is larger than the thickness of the concave portion,
The said convex part forms the many thin lines of 50-200 micrometers width formed by the said inkjet printing at 0-200 micrometers space | interval, The display board characterized by the above-mentioned.   2. The display panel according to claim 1, wherein at least a part of the design layer contains one or more selected from a metallic pigment, metal fine particles, and metal foil.   3. The design layer according to claim 1, wherein the design layer includes one or two or more colored layers, and at least one of the colored layers contains one or more selected from metallic pigments, metal particles, and metal foils. A display panel comprising a metallic colored layer.   In Claim 3, the said design layer which consists of the said metal color colored layer is formed on the said design surface of the said resin substrate through the base printed layer of the surface 60 degree | times-glossiness 5 or more prescribed | regulated to JISK5600. A display panel, wherein the concavo-convex layer is formed on the design layer.   4. The resin substrate according to claim 3, wherein the resin substrate has a mirror surface having a surface of 60 degrees-glossiness of 5 or more as defined in JISK5600 on the surface of the design surface, and the metal color coloring layer is formed on the design surface having the mirror surface. The display panel, wherein the design layer is formed, and the uneven layer is formed on a surface of the resin substrate opposite to the design surface.   6. The display panel according to claim 1, wherein the uneven layer is made of the transparent ultraviolet curable ink.   6. The concavo-convex layer according to claim 1, wherein the concavo-convex layer is colored and is one or two selected from black, cyan, magenta, yellow, light black, light cyan, light magenta, light yellow, and white. A display panel comprising the ultraviolet curable ink of the above color.   8. The display panel according to claim 1, wherein the uneven layer is formed by inkjet printing having a resolution of 1200 DPI × 1200 DPI or more.   9. The display panel according to claim 1, wherein a thickness difference between the concave portion and the convex portion is 1 to 300 [mu] m.   10. The display panel according to claim 1, wherein the thin line is formed by laminating two or more layers of the drawn line made of the ultraviolet curable ink formed by the ink jet printing in the thickness direction. .   11. The display panel according to claim 10, wherein the thin line is formed by laminating the drawn line so that the width of the fine line decreases with increasing distance from the resin substrate.   12. The display panel according to claim 10, wherein at least two of the drawn lines in the laminated state are made of the ultraviolet curable inks having different colors.   The display panel according to any one of claims 10 to 12, wherein the uppermost layer of the drawn lines in the laminated state is made of black or a black color.   14. The concave-convex layer according to claim 1, wherein the concave-convex layer forms a concentric pattern in which the plurality of concave portions and the plurality of convex portions are alternately arranged concentrically. Display board.   15. The display panel according to claim 14, wherein the concentric pattern is composed of two concentric circles having different center positions, and the center-to-center distance is 10 to 1000 [mu] m.   In any 1 item | term of the Claims 1-13, The said uneven | corrugated layer forms the hairline pattern by which the said several linear said recessed part and the several said linear convex part are alternately arranged. Characteristic display board.   In any 1 paragraph of Claims 1-13, the above-mentioned concavo-convex layer forms the Asahi perception pattern where a plurality of above-mentioned convex parts are arranged radially from the central part or the central part which are substantially the same. A display board characterized by   18. A display panel according to claim 1, wherein at least a part of the display panel is provided with a three-dimensional shape by vacuum forming or pressure forming. A transparent resin substrate having a thickness of 1 mm or less, a colored design layer formed on the resin substrate, and a surface opposite to the design surface on which the design layer is formed on the design layer or the resin substrate A method for producing a display panel having a concavo-convex layer formed by alternately forming a plurality of concave portions and convex portions,
A design layer forming step of forming the design layer by printing colored colored ink on the resin substrate;
Using an ink jet printing apparatus comprising at least an ink ejection unit that ejects an ultraviolet curable ink, an ultraviolet irradiation unit that incorporates an ultraviolet lamp, and a holding unit that holds the resin substrate as a substrate to be printed, on the design layer or A discharge operation for discharging the ultraviolet curable ink from the ink discharge portion on a surface opposite to the design surface on which the design layer is formed on the resin substrate, and the ultraviolet irradiation portion on the discharged ultraviolet curable ink. A concavo-convex layer forming step of forming the concavo-convex layer so that the thickness of the convex portion is larger than the thickness of the concave portion by repeatedly performing a curing operation of irradiating ultraviolet rays from the above and curing the ultraviolet curable ink. Have
In the concavo-convex layer forming step, the ultraviolet curable ink is ejected while moving the ink ejection part of the ink jet printing apparatus in one direction at 20 to 200 m per minute relative to the holding part, By repeating the operation of printing by irradiating ultraviolet rays and the operation of moving the holding portion by 1 pitch perpendicular to the one direction with respect to the ink ejection portion, a large number of thin lines having a width of 50 to 200 μm are reduced to 0. A method for producing a display panel, wherein the convex portions are formed at intervals of ˜200 μm. 20. The design layer forming step according to claim 19, wherein at least a part of the design layer is formed by the colored ink containing at least one selected from a metallic pigment, metal fine particles, and metal foil. A manufacturing method of a display panel.   21. The design layer forming step according to claim 19, wherein in the design layer formation step, the design layer composed of one or two or more colored layers is formed by stacking and printing one or two or more of the colored inks. A method for producing a display panel, wherein at least one of the colored layers is formed of a metallic color layer with the colored ink containing a metallic pigment and / or metal particles.   23. In the design layer forming step according to claim 21, a base printed layer having a surface of 60 degrees-glossiness of 5 or more as defined in JISK5600 is formed on the design surface of the resin substrate, and the metal is formed on the base printed layer. A method for producing a display panel, comprising: forming a color-colored layer, and forming the uneven layer on the design layer in the uneven layer forming step.   The resin substrate according to claim 21, wherein the resin substrate is a resin substrate having a mirror surface with a surface of 60 degrees-a glossiness of 5 or more as defined in JISK5600 on the surface of the design surface. In the design layer forming step, the resin substrate A display panel comprising: forming at least the metal color layer on the mirror surface; and forming the uneven layer on a surface of the resin substrate opposite to the design surface in the uneven layer forming step. Manufacturing method.   24. In the uneven layer forming step according to any one of claims 19 to 23, the droplets of the ultraviolet curable ink are ejected from the ink ejection portion at a volume of 20 pL or less per droplet. A manufacturing method of a display panel.   25. The method for manufacturing a display panel according to any one of claims 19 to 24, wherein in the uneven layer forming step, the uneven layer is formed of a transparent ultraviolet curable ink.   25. The uneven layer forming step according to any one of claims 19 to 24, wherein in the uneven layer forming step, the uneven layer is selected from black, cyan, magenta, yellow, light black, light cyan, light magenta, light yellow, and white. Or a method of manufacturing a display panel, wherein the display panel is formed of ultraviolet curable inks of two or more colors.   27. The display according to claim 19, wherein, in the uneven layer forming step, the uneven layer is formed so that a thickness difference between the concave portion and the convex portion is 1 to 300 [mu] m. Board manufacturing method.   In any one of Claims 19-27, in the said uneven | corrugated layer formation process, while forming the drawn line which consists of the said ultraviolet curable ink by the said inkjet printing, two or more layers of this drawn line are piled up in the thickness direction. A method of manufacturing a display panel, wherein the fine line is formed by printing.   29. A method of manufacturing a display panel according to claim 28, wherein, when the drawn lines are stacked and formed, the drawn lines having a smaller width are stacked in the stacking direction as the distance from the resin substrate increases.   30. The method for manufacturing a display panel according to claim 28, wherein at least two of the drawn lines formed in a laminated state are formed of the ultraviolet curable inks of different colors.   31. The display according to claim 28, wherein, among the drawn lines formed in a stacked state, the uppermost drawn line is formed by the ultraviolet curable ink made of black or black. Board manufacturing method.   32. The concavity and convexity formation layer according to any one of claims 19 to 31, wherein in the concavity and convexity layer forming step, the concavity and convexity concavity and convexity layer are formed in which the plurality of concave portions and the plurality of convex portions are alternately arranged concentrically. A display panel manufacturing method characterized by the above.   33. The method for manufacturing a display panel according to claim 32, wherein the concentric pattern is composed of two concentric circles having different center positions, and the distance between the centers is 10 to 1000 [mu] m.   32. The concavo-convex layer of a hairline pattern according to any one of claims 19 to 31, wherein in the concavo-convex layer forming step, a plurality of linear concave portions and a plurality of linear convex portions are alternately arranged. A method of manufacturing a display panel, characterized by comprising:   32. In the uneven layer forming step according to any one of claims 19 to 31, the unevenness of an Asahi light weight pattern in which a plurality of the convex portions are arranged radially from substantially the same central portion or the vicinity of the central portion. A method for manufacturing a display panel, comprising forming a layer.   36. The method for manufacturing a display panel according to any one of claims 19 to 35, wherein the printing in the uneven layer forming step is performed at a resolution of 1200 DPI × 1200 DPI or more.   37. The ink jet printing according to any one of claims 19 to 36, wherein, in the concave-convex layer forming step, the ink jet printing is performed with different resolutions in a moving direction of the ink discharge unit and a moving direction of the holding unit. Manufacturing method of display panel.   38. The method for manufacturing a display panel according to any one of claims 19 to 37, further comprising a molding step of applying a three-dimensional shape to at least a part of the resin substrate by vacuum molding or pressure molding.

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