JP2002036731A - Image forming method - Google Patents

Abstract

(57) [Problem] To provide an image forming method capable of obtaining a multicolor image, particularly an image in which a pattern and text data coexist at high speed, at low cost, and in a state where a full color image can be obtained by a thermal transfer method. I do. A method for forming a multi-color image using a two-color thermal transfer ink ribbon of a chromatic color and an achromatic color, wherein the chromatic thermal transfer ink ribbon has a color tone Lab value of L
= 30 to 70, a = 10 to 70, b = 0 to 75, using a thermal transfer ink ribbon, and achromatic thermal transfer ink ribbon using a thermal transfer ink ribbon having a reflection density of 1.0 or more. Forming an image by thermal transfer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer printer, such as a thermal head printer, for selectively thermally transferring a chromatic thermal ink and an achromatic thermal transfer ink onto an image receiving body to form a multicolor image. About the method.

[0002]

2. Description of the Related Art Conventionally, when full-color expression is performed by thermal transfer, three colors of process colors, cyan (C), magenta (M), and yellow (Y), or black (BK) is added to these three colors. The expression is made using the range of colors obtained by subtractive color mixture by color superposition.

In this method, a high-quality color image close to a natural color can be obtained, but there is a disadvantage that the image data becomes too large when outputting the image. In addition, it is necessary to superimpose the colors three or four times when outputting, so that it takes a long time to form an image and the ink ribbon consumption is not always satisfactory. In particular, when text data such as a picture and a character coexist in an image, a case where four process colors obtained by adding black (BK) to three colors of cyan (C), magenta (M), and yellow (Y) is used. In many cases, resulting in the above disadvantage.

[0004] Further, depending on the image to be handled, a high-quality and wide color reproduction image such as the full-color image may not be necessary. For example, in an instruction manual of a device, a layout diagram of a device, and the like, there is a tendency that it is preferable to obtain an image at a higher speed and at a lower cost than color reproduction. However, an image forming method that meets this requirement has not been realized yet.

[0005]

SUMMARY OF THE INVENTION In view of the foregoing, it is an object of the present invention to provide a high-speed, low-cost, full-color image of a multicolor image, particularly an image in which a pattern and text data coexist, by a thermal transfer method. An object of the present invention is to provide an image forming method which can be obtained in a state.

[0006]

That is, the present invention relates to a method for forming a multicolor image using two-color thermal transfer ink ribbons of chromatic and achromatic colors. And the color tone Lab value is L = 30 to 70, a
= 10 to 70, b = 0 to 75, an image is formed by thermal transfer using a thermal transfer ink ribbon having a reflection density of 1.0 or more as an achromatic thermal transfer ink ribbon. And an image forming method.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention provides a multi-color image by using a chromatic thermal transfer ink ribbon and an achromatic thermal transfer ink ribbon and superimposing inks by a thermal transfer method.
In particular, the present invention provides a method for forming an image in which text data such as pictures and characters coexist at high speed and at low cost.

The inventors of the present invention have conducted intensive studies to achieve this object. As a result, the chromatic thermal transfer ink ribbon has a color tone Lab value of L = 30-70, a = 10-70,
Using a thermal transfer ink ribbon with b = 0 to 75, the achromatic thermal transfer ink ribbon having a reflection density of 1.
It has been found that this object is achieved by using a thermal transfer ink ribbon having a value of 0 or more.

Here, L, a, and b are scales when colors are represented on solid coordinates, are numerical values measured by a color difference meter, and are one of the colorimetry methods generally used today. .
That is, b and a are respectively represented on a vertical axis and a horizontal axis that intersect at right angles on the same plane, and when an axis perpendicular to the plane is taken from an intersection of the vertical axis and the horizontal axis, the height from the plane is expressed as L, which means lightness, that is, brightness.
The larger L is, the brighter it is. If the chromatic color L is less than 30, the image lacks brightness and the image becomes dark. Conversely, L
Exceeds 70, the saturation becomes low and it becomes difficult to express natural colors. a and b represent hues, a represents the value of the intersection of the ordinate and the abscissa as 0, and the greater the numerical value in the rightward direction, that is, on the (+) side from the ordinate, the greater the degree of redness and the leftward direction. That is, on the (−) side, the degree of greenness is large. On the other hand, b indicates the value of the intersection of the vertical axis and the horizontal axis as 0, and indicates the degree of yellowish in the upward direction from the horizontal axis, that is, on the (+) side, and the degree of bluish in the downward direction from the horizontal axis, that is, on the (-) side. Things. When the chromatic colors a and b are within the above range, the image has an appropriate reddish and yellowish tinge, thereby enabling a warm color expression. Outside the above range, the red and yellow colors are weakened and a warm color cannot be expressed, and the whole image has a configuration of only a cold color, and there is no warmth and it cannot be said that a natural color is expressed.

On the other hand, achromatic ribbons used together with the chromatic ribbons described above require a certain reflection density in order to express a cold portion and a shadow portion (shadow portion) in an image. If the reflection density is less than 1.0, this expression cannot be made and an image without sharpness is obtained. Further, the density of the achromatic color needs to be 1.0 or more in order to express text data such as good characters. If the reflection density is less than 1.0, the density of the black characters is reduced, making it difficult to read.

In the present invention, the Lab value is obtained by measuring the surface of the colored layer of the thermal transfer ink ribbon with a colorimeter CR221.
(Minolta Co., Ltd.). The achromatic reflection density is measured by using a reflection densitometer Gretag Macbeth RD-918 (manufactured by Macbeth) on the surface of the colored layer.

The chromatic and achromatic ink ribbons used in the method of the present invention are not particularly limited as long as they satisfy the above-mentioned color tone conditions and reflection density conditions.

For example, a basic structure of the chromatic and achromatic ink ribbons is a structure in which a heat-sensitive transfer colored layer is provided on a support. As the coloring layer, those composed of various materials conventionally used for thermal transfer inks can be used. Mainly, a mixture of a thermoplastic resin and / or a wax material as a binder and a colorant dispersed therein is used.

Examples of the thermoplastic resin include olefin copolymers such as ethylene / vinyl acetate copolymer, polyamide resins, polyester resins, butyral resins, methacrylic acids such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, and hydroxyethyl methacrylate. One or more homopolymers or copolymers selected from the group consisting of esters, acrylates such as methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, and acrylic acid, natural rubber, petroleum resin Rosin resin, styrene resin, and the like. These resins can be used alone or in combination of two or more.

Examples of the wax material include paraffin wax, microcrystalline wax, Fischer-Tropsch wax, polyethylene waxes of various molecular weights and modified waxes thereof, and carnauba wax. These wax materials can be used alone or in combination of two or more.

As the colorant, various pigments and dyes can be used. Examples of the chromatic colorant include azo, quinacridone, thioindigo, perylene, isoindoline and phthalocyanine pigments. I can do it. These have a Lab value of the colored layer of L = 30-7.
0, a = 10-70, b = 0-75,
They can be used alone or in combination of two or more. Examples of the achromatic colorant include carbon black.

In order to ensure a vivid density of chromatic colors, the content of the coloring agent per unit area of the coloring layer should be 0.3.
Preferably in the range of to 1.5 g / m ^2. When the content per unit area of the colorant is less than 0.3 g / m ² , the density is insufficient, while when it exceeds 1.5 g / m ² , the vividness tends to be impaired.

In order to increase the overall color depth of a chromatic color, a main colorant (refers to a colorant that determines the hue of a colored layer)
On the other hand, a pigment having a high concentration such as a black pigment such as carbon black or a phthalocyanine pigment, or various fillers having a high light shielding property such as titanium oxide and aluminum powder may be appropriately added. The amount of addition of these auxiliary components is 0.1 to
Preferably, it is 20%, more preferably 0.1%.
〜１０10%. If the amount of the auxiliary component is less than the above range, the effect of improving the depth is hardly exhibited, while if it exceeds the above range, the color tends to lack vividness.

In order to control the adhesion of the surface of the colored layer,
A surface modifier such as a lubricant and various fillers may be added.

In the case of an achromatic colored layer, various fillers having a high light-shielding property such as titanium oxide and aluminum powder may be added for the purpose of enhancing the concealing property.

The thickness of the colored layer is preferably thinner from the viewpoint of image reproducibility, and is suitably 0.2 to 3.0 μm. When the thickness of the coloring layer is less than the above range, the coloring density tends to be insufficient, and when the thickness exceeds the above range, the transfer sensitivity tends to be insufficient.

In the ink ribbon used in the present invention,
In order to improve the adhesiveness of the surface, an adhesive layer mainly composed of a thermoplastic resin may be provided on the colored layer. As the thermoplastic resin, the same thermoplastic resin as the binder for the colored layer can be appropriately selected and used.

In the case where the releasability of the colored layer from the support is poor, it is more preferable to provide a heat-meltable release layer between the support and the colored layer. The release layer contains a wax material as a main component, and may optionally contain a thermoplastic resin. As the wax material, the same material as the wax material used in the coloring layer can be appropriately selected and used. Examples of the thermoplastic resin include an olefin copolymer such as an ethylene / vinyl acetate copolymer, a polyamide resin, a polyester resin, a natural rubber, a petroleum resin, a rosin resin, and a styrene resin. As the thickness of the release layer,
The range is preferably from 0.1 to 2.0 μm from the viewpoint of thermal transfer suitability.
If the thickness of the release layer is less than the above range, the effect of improving the releasability will not be sufficiently exhibited, while if it exceeds the range, the amount of heat will be excessively applied to the melting of the release layer, and the transferability tends to decrease.

As the support used for the ink ribbon, various materials which have been conventionally used as a support for a thermal transfer ink ribbon can be used, but from the viewpoint of heat resistance, heat transferability and cost, the thickness can be reduced. A polyester film of 1 to 6 μm or the like is preferable, and a polyethylene terephthalate film (PET film) is particularly preferable. It is preferable to provide a heat-resistant lubricating layer on the back surface of the support (the surface on which the thermal head or the like slides).

The method of forming a multicolor image using the two-color thermal transfer ink ribbons of chromatic and achromatic colors according to the present invention can be performed, for example, as follows. Image processing of the original image, decomposing it into three components, for example, red, green, and blue, and assigning a chromatic ribbon to the red image data,
An achromatic ribbon is assigned to green or blue image data and printed. Text data is printed using an achromatic ribbon.

The image forming method of the present invention is particularly preferably used for forming an image in which a multicolor picture and text data coexist, but can also be used for printing only a picture or text data such as characters. .

[0027]

Next, the present invention will be described with reference to examples.

<Colored ribbon 1> 0.2 μm thick on the back
2.5μm thickness provided with a silicone resin-based heat-resistant lubricating layer
Was used as a support. The following coating liquid for a release layer is applied to the surface side of this support and dried to a thickness of 0.7.
A μm release layer was formed.

[0029] Coating solution for mold release layer Component weight part Paraffin wax (melting point 75 ° C) 7.0 Polyethylene wax (melting point 90 ° C) 3.0 Toluene 90.0 Total 100.0

On the release layer, the following coating solution for a colored layer was applied and dried to form a colored layer having a thickness of 1.5 μm, whereby a chromatic ribbon 1 was obtained.

Coating solution for coloring layer Component Weight parts Ethylene / vinyl acetate copolymer ^{* 1} 5.0 Terpene phenol resin (melting point: 120 ° C.) 2.0 Phthalocyanine blue 3.0 Dispersant 0.3 Toluene 40.0 Total 50.3 * 1: Vinyl acetate content 28% by weight, melt flow rate 150 (hereinafter the same)

<Chromatic ribbon 2> A chromatic ribbon 2 was obtained in the same manner as in the case of the chromatic ribbon 1 except that a colored layer having a thickness of 1.5 μm was formed using the following coating liquid.

Coloring Layer Coating Composition Ingredients Parts by weight Ethylene / vinyl acetate copolymer 5.0 Terpene phenol resin (melting point 120 ° C.) 2.0 Carmine 6B 3.0 Dispersant 0.3 Toluene 40.0 Total 50. 3

<Chromatic ribbon 3> A chromatic ribbon 3 was obtained in the same manner as in the case of the chromatic ribbon 1 except that a colored layer having a thickness of 1.5 μm was formed using the following coating liquid.

Coloring Layer Coating Composition Ingredients Parts by weight Ethylene / vinyl acetate copolymer 5.0 Terpene phenol resin (melting point 120 ° C.) 2.0 Disazo Yellow 3.0 Dispersant 0.3 Toluene 40.0 Total 50. 3

<Colored ribbon 4> A chromatic ribbon 4 was obtained in the same manner as in the case of the chromatic ribbon 1 except that a colored layer having a thickness of 1.5 μm was formed using the following coating liquid.

Coloring Layer Coating Composition Ingredients Parts by Weight Ethylene / vinyl acetate copolymer 5.0 Terpene phenol resin (melting point 120 ° C.) 2.0 Anthraquinonyl Red 3.0 Carbon black 0.2 Dispersant 0.1 Toluene 40.0 Total 50.3

<Colored Ribbon 5> A chromatic ribbon 5 was obtained in the same manner as in the case of the chromatic ribbon 1 except that a colored layer having a thickness of 1.5 μm was formed using the following coating liquid. Colored layer coating solution Component Parts by weight Ethylene / vinyl acetate copolymer 5.0 Terpene phenol resin (melting point 120 ° C) 2.0 Phthalocyanine green 2.5 Disazo Yellow 0.3 Carbon black 0.2 Dispersant 0.1 Toluene 40.0 Total 50.1

<Colored ribbon 6> A chromatic ribbon 6 was obtained in the same manner as in the case of the chromatic ribbon 1 except that a colored layer having a thickness of 1.5 μm was formed using the following coating liquid.

Coloring Layer Coating Composition Ingredients Parts by weight Ethylene / vinyl acetate copolymer 5.0 Terpene phenol resin (melting point 120 ° C.) 2.0 Indathrene blue 2.5 Phthalocyanine blue 0.5 Carbon black 0.2 Dispersion Agent 0.1 Toluene 40.0 Total 50.3

<Colored Ribbon 7> A chromatic ribbon 7 was obtained in the same manner as in the case of the chromatic ribbon 1 except that a colored layer having a thickness of 1.5 μm was formed using the following coating liquid.

Coloring Layer Coating Composition Ingredients Parts by Weight Ethylene / vinyl acetate copolymer 5.0 Terpene phenol resin (melting point 120 ° C.) 2.0 Carmine 6B 2.7 Disazo Yellow 1.5 Dispersant 0.5 Toluene 40 .0 Total 51.7

<Colored ribbon 8> A chromatic ribbon 8 was obtained in the same manner as in the case of the chromatic ribbon 1 except that a colored layer having a thickness of 1.5 μm was formed using the following coating liquid.

Coloring Layer Coating Composition Ingredients Parts by weight Ethylene / vinyl acetate copolymer 5.0 Terpene phenol resin (melting point 120 ° C.) 2.0 Carmine 6B 1.5 Disazo Yellow 2.7 Dispersant 0.5 Toluene 40 .0 Total 51.7

The Lab value of the surface of the colored layer of each of the chromatic ribbons 1 to 8 is measured using a color difference meter CR221 (manufactured by Minolta Co., Ltd.).
It measured using. Table 1 shows the results.

[0046]

[Table 1]

<Achromatic ribbon 1> An achromatic ribbon 1 was obtained in the same manner as the chromatic ribbon 1 except that a colored layer having a thickness of 1.5 μm was formed using the following coating liquid.

Coloring Layer Coating Composition Ingredients Parts by weight Ethylene / vinyl acetate copolymer 5.0 Terpene phenol resin (melting point 120 ° C.) 1.5 Carbon black 3.5 Dispersant 0.3 Toluene 40.0 Total 50. 3

<Achromatic ribbon 2> An achromatic ribbon 2 was obtained in the same manner as in the case of the chromatic ribbon 1 except that a colored layer having a thickness of 1.5 μm was formed using the following coating liquid.

Coloring Layer Coating Composition Ingredients Parts by weight Ethylene / vinyl acetate copolymer 5.0 Terpene phenol resin (melting point 120 ° C.) 1.5 Carbon black 2.0 Dispersant 0.1 Toluene 40.0 Total 48. 6

<Achromatic ribbon 3> An achromatic ribbon 3 was obtained in the same manner as in the case of the chromatic ribbon 1 except that a colored layer having a thickness of 1.5 μm was formed using the following coating liquid.

Coloring Layer Coating Composition Ingredients Parts by weight Ethylene / vinyl acetate copolymer 5.0 Terpene phenol resin (melting point 120 ° C.) 1.5 Carbon black 1.0 Dispersant 0.1 Toluene 40.0 Total 47.0 6

The reflection density of the surface of the colored layers of the achromatic ribbons 1 to 3 was measured using Gretag Macbeth RD-918 (manufactured by Macbeth). Table 2 shows the results.

[0054]

[Table 2]

<Evaluation Method> Evaluation of picture image Full-color evaluation pattern (Fruit basket (ISO / DIS
12640 registration data)) image data was divided into red, green, and blue. Using a chromatic ribbon corresponding to this red data, using an achromatic ribbon corresponding to the blue data, overlay printing under the following printing conditions to form an image, and observe the obtained image with the naked eye The color reproducibility of the image was evaluated according to the following criteria. Table 3 shows the results.

Printing conditions Printer: Thermal printer (test machine) Print head: 600 dpi (edge distance 100 μm)
m) Printing speed: 25.4 cm / sec Image receiving body: Super Matt Art Paper (Mitsubishi Paper Corp.)

Evaluation criteria ：: Natural expression is obtained Δ: Some natural expression is obtained ×: Natural expression is not obtained

2. Text Image Evaluation Using an achromatic ribbon, text data was printed under the same printing conditions as described above, and the clarity of the obtained characters was evaluated according to the following criteria. Table 3 shows the results.

Evaluation criteria ：: A clear character is obtained Δ: A somewhat clear character is obtained X: A thin and unclear character is obtained

[0060]

[Table 3]

[0061]

According to the present invention, an image in which a multi-color picture and text data coexist can be obtained at high speed and at low cost, and in a state where the image can be imaged in full color by the thermal transfer method.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tetsuo Hoshino 5-4-1-14 Miteshima, Nishiyodogawa-ku, Osaka-shi, Osaka Inside Fujikopian Corporation Technical Center (72) Inventor Yasuminori Inoue 1st, Yukitani-Otsukacho, Ota-ku, Tokyo No. 7 Alps Electric Co., Ltd. F-term (reference) 2C068 AA02 AA06 2H111 AA47 BA61

Claims (1)

[Claims] 1. A method for forming a multi-color image using a two-color thermal transfer ink ribbon of a chromatic color and an achromatic color, wherein the chromatic thermal transfer ink ribbon has a color tone Lab value of L.
= 30 to 70, a = 10 to 70, b = 0 to 75, using a thermal transfer ink ribbon, and achromatic thermal transfer ink ribbon using a thermal transfer ink ribbon having a reflection density of 1.0 or more. Forming an image by thermal transfer.