WO2018186342A1 - Optical sheet, backlight unit, method for manufacturing optical sheet, and device for manufacturing optical sheet - Google Patents

Abstract

Provided is an optical sheet having a structure for shielding a quantum dot from a deactivating substance, wherein, for the purpose of reducing a frame region and more easily manufacturing the optical sheet, the optical sheet (5a) is provided with a quantum dot layer (10) having quantum dots (15/16), a first barrier layer (11) as a lower layer than the quantum dot layer, a second barrier layer (12) as a higher layer than the quantum dot layer, and barrier walls (13) for covering end surfaces of the quantum dot layer.

Description

Optical sheet, backlight unit, optical sheet manufacturing method, optical sheet manufacturing apparatus

The present invention relates to an optical sheet including quantum dots, an optical sheet manufacturing method, an optical sheet manufacturing apparatus, and a backlight unit including the optical sheet.

Patent Document 1 describes a wavelength conversion member in which a barrier layer is formed on the entire circumference of a quantum dot layer and a manufacturing method thereof.

International Publication Gazette “WO2016 / 104401A1 (released on June 30, 2016)”

The inventor has found that it is difficult to form a barrier layer all around the quantum dot layer, and that the frame region increases due to the formation of the barrier layer.

In order to solve the above problems, an optical sheet according to an aspect of the present invention is an optical sheet including a quantum dot layer having quantum dots between a plurality of barrier layers, and an end face of the quantum dot layer A barrier wall is provided.

In order to solve the above problems, an optical sheet manufacturing method according to an aspect of the present invention includes: a stacked layer in which quantum dot layers having quantum dots are formed, and barrier layers are formed on upper and lower surfaces of the quantum dot layers, respectively. A stacking process for manufacturing a structure, and a barrier wall forming process for forming a barrier wall different from the barrier layer at a peripheral edge of the quantum dot layer.

According to one embodiment of the present invention, it is possible to provide an optical sheet that can more easily form a structure for protecting the quantum dot layer while reducing an increase in the frame region.

It is sectional drawing of the optical sheet which concerns on Embodiment 1 of this invention. It is the perspective view and sectional drawing of the backlight unit which concern on Embodiment 1 of this invention. It is a flowchart which shows the manufacturing method of the optical sheet which concerns on Embodiment 1 of this invention. It is process sectional drawing for demonstrating the manufacturing method of the optical sheet which concerns on Embodiment 1 of this invention. It is process sectional drawing for demonstrating the other example of the manufacturing method of the optical sheet which concerns on Embodiment 1 of this invention. It is sectional drawing of the optical sheet which concerns on Embodiment 2 of this invention. It is a flowchart which shows the manufacturing method of the optical sheet which concerns on Embodiment 2 of this invention. It is process sectional drawing for demonstrating the manufacturing method of the optical sheet which concerns on Embodiment 2 of this invention. It is sectional drawing of the backlight unit which concerns on Embodiment 3 of this invention. It is process sectional drawing for demonstrating the manufacturing method of the backlight unit which concerns on Embodiment 3 of this invention. It is sectional drawing of the optical sheet which concerns on Embodiment 4 of this invention. It is process sectional drawing for demonstrating the manufacturing method of the optical sheet which concerns on Embodiment 4 of this invention. It is process sectional drawing for demonstrating the manufacturing method of the optical sheet which concerns on Embodiment 5 of this invention. It is process sectional drawing for demonstrating the manufacturing method of the optical sheet which concerns on Embodiment 6 of this invention. It is a block diagram which shows the manufacturing apparatus of the optical sheet which concerns on each embodiment of this invention. It is the upper side figure and enlarged sectional view which show the optical sheet which concerns on a comparison form.

In this specification, the “vertical direction” of the optical sheet refers to a direction parallel to the traveling direction of the light transmitted through the optical sheet when the optical sheet is actually used. The “peripheral direction” of the optical sheet refers to a direction perpendicular to the traveling direction of light transmitted through the optical sheet when the optical sheet is actually used. In addition, for convenience of explanation, in each embodiment, members having the same functions as those described above are denoted by the same reference numerals, and description thereof is omitted.

First, an optical sheet according to a comparative embodiment will be described with reference to FIG. FIG. 16A is a top view of the optical sheet of the comparative embodiment, and FIG. 16B is a top view of the optical sheet that has changed over time from the state of FIG. FIGS. 16C and 16D show cross sections taken along arrows B1-B2 in FIGS. 16A and 16B, respectively.

The optical sheet of the comparative form includes first and second barrier layers 11 and 12 on the upper and lower surfaces of the quantum dot layer 10, respectively. In general, from the viewpoint of manufacturing efficiency, an optical sheet is manufactured by being divided into a predetermined size after being manufactured in a large size. For this reason, the division | segmentation for individualization produces the surface in which the barrier layer is not formed in the end surface of an optical sheet. Therefore, as shown in FIG. 1C, moisture may enter the resin 14 from the end face of the optical sheet. When the red fluorescent quantum dots 15 and the green fluorescent quantum dots 16 react with moisture that has entered the resin 14, the red fluorescent quantum dots 15 and the green fluorescent quantum dots 16 are deactivated, as shown in FIG. In addition, the ability of wavelength conversion of the irradiated light is reduced.

As shown in FIG. 1 (d), when blue light is irradiated from the lower surface of the optical sheet, at the position of the optical sheet where the quantum dots are not deactivated, part of the blue light is caused by each quantum dot. , Converted into red light and green light. For this reason, it is considered that white light is irradiated from the upper surface of the optical sheet by averaging the components of the blue light that has not been wavelength-converted by the quantum dots and the above-described wavelength-converted red light and green light. be able to.

However, at the position of the optical sheet where the quantum dots are deactivated, the proportion of light that is wavelength-converted by each quantum dot decreases. For this reason, in the peripheral edge part of an optical sheet, the ratio of the blue light permeate | transmitted as it is becomes large, and the light whose blue light component is stronger than white light is irradiated from the upper surface of an optical sheet.

Therefore, when the backlight unit using the optical sheet of the comparative form is adopted in the display device, the display at the peripheral edge of the screen becomes bluish due to a change with time, which may cause a display defect. In order to prevent display defects, it is necessary to prevent a substance that deactivates quantum dots from entering the quantum dot layer.

Embodiment 1
FIG. 2 is a view for explaining the backlight unit 1a according to the present embodiment. 2A is a perspective view of the backlight unit 1a, and FIG. 2B is a cross-sectional view taken along arrow A1-A2 in FIG.

The backlight unit 1 of the present embodiment is a backlight unit that projects white light. As shown in FIG. 2, the backlight unit 1a includes a reflecting plate 2, a light guide plate 4 provided with a blue light emitting element 3, an optical sheet 5a, and first and second lens sheets 6a and 6b in this order. Do it.

Blue light from the blue light emitting element 3 is guided by the light guide plate 4 and irradiated from the upper and lower surfaces of the light guide plate 4 with substantially uniform light intensity at any position. The blue light irradiated from the lower surface of the light guide plate 4 is reflected upward by the reflection plate 2. Part of the blue light incident on the optical sheet 5a is converted into red light and green light by the quantum dots included in the optical sheet 5a. The blue light that has not been converted by the quantum dots of the optical sheet 5a passes through the optical sheet 5a as it is. The aforementioned red light, green light, and blue light are scattered by the scattering material in the optical sheet 5a. For this reason, the emitted light from the optical sheet 5a is diffused and made uniform. The first and second lens sheets 6a and 6b improve the luminance of the optical sheet 5a by condensing the optical path of the light transmitted through the optical sheet 5a in the emission direction perpendicular to the plane of the optical sheet 5a.

The respective components of blue light, red light, and green light transmitted through the lens sheet are made uniform, so that the backlight unit 1a according to the present embodiment irradiates substantially white light upward from the upper surface of the lens sheet. .

FIG. 1 is a diagram for explaining an optical sheet 5a according to the present embodiment. FIG. 1A is an enlarged cross-sectional view of the optical sheet 5a in FIG. FIG. 1B is a top view of the optical sheet 5a.

The optical sheet 5 a includes a quantum dot layer 10, first and second barrier layers 11 and 12, and a barrier wall 13. The quantum dot layer 10 includes a resin 14, a red fluorescent quantum dot 15, a green fluorescent quantum dot 16, and a scattering material 17.

The quantum dot layer 10 is obtained by dispersing the red fluorescent quantum dots 15, the green fluorescent quantum dots 16, and the scattering material 17 substantially uniformly in the resin 14. Each of the red fluorescent quantum dots 15 and the green fluorescent quantum dots 16 has a property of emitting fluorescence when blue light is incident thereon. The red fluorescent quantum dots 15 produce red light and the green fluorescent quantum dots 16 produce green light as fluorescent light. The scattering material 17 has a property of scattering incident light. Since blue light, red light, and green light scattered by the scattering material are averaged, the blue light irradiated to the quantum dot layer 10 behaves as substantially white light after passing through the quantum dot layer 10.

The quantum dot layer 10 is formed between the first and second barrier layers 11 and 12. A substance (for example, moisture) that deactivates red fluorescent quantum dots 15 and green fluorescent quantum dots 16 described later cannot pass through the first and second barrier layers 11 and 12. For this reason, the first and second barrier layers 11 and 12 prevent the substance that deactivates the quantum dots from entering the quantum dot layer 10.

A barrier wall 13 different from the first and second barrier layers 11 and 12 is formed on the entire circumference of the end surfaces of the quantum dot layer 10 and the first and second barrier layers 11 and 12. The barrier wall 13 has properties similar to those of the first and second barrier layers 11 and 12 and prevents a substance that deactivates the quantum dots from entering the quantum dot layer 10. As shown in FIG. 1B, the entire circumference of the end face of the optical sheet 5 a is formed by the barrier wall 13. That is, the barrier wall 13 is formed so as to cover the entire end surface of the quantum dot layer 10 of the optical sheet 5a. Furthermore, in the present embodiment, the barrier wall 13 is formed at a position covering the edges Ka and Kb at the interface between the quantum dot layer 10 and the first and second barrier layers 11 and 12.

A method for manufacturing the optical sheet 5a will be described with reference to FIGS. FIG. 3 is a flowchart showing an example of the manufacturing method of the optical sheet 5a, and FIGS. 4A to 4C are cross-sectional views showing an example of the manufacturing method of the optical sheet 5a in the order of steps.

First, the first barrier layer 11, the quantum dot layer 10, and the second barrier layer 12 are formed in order (S11 to S13) to obtain a stacked structure shown in FIG. The first barrier layer 11, the quantum dot layer 10, and the second barrier layer 12 are coated with a predetermined thickness of each material using an extrusion molding machine, an inkjet, a coating machine, a transfer device, etc. Alternatively, it may be obtained by molding. Lamination may be used for bonding the quantum dot layer 10 to the first and second barrier layers 11 and 12.

Next, the laminated structure is separated into pieces having a predetermined size smaller than the large size by dividing (S14). As a result, the optical sheet 5x shown in FIG. 4B before the barrier wall 13 is formed is obtained. In this case, as shown in FIG. 4B, the barrier layer is not formed on the end face of the divided optical sheet 5x, and the quantum dot layer 10 is exposed.

Finally, a barrier wall resin 13a, which is a material of the barrier wall 13, is applied to a position covering the end face of the optical sheet 5x from which the quantum dot layer 10 is exposed, whereby the optical sheet shown in FIG. 5a is obtained. Thereafter, the barrier wall 13 may be formed (S15) by curing the barrier wall resin 13a.

Here, the barrier wall resin 13a may be an ultraviolet curable resin. If it is the said structure, generation | occurrence | production of the damage to a quantum dot resulting from the heat | fever in thermosetting can be prevented. Furthermore, if it is the said structure, due to the heat | fever in thermosetting, a sheet | seat expansion | swelling or expansion-contraction can reduce the possibility that the sheet | seat will generate | occur | produce. As the ultraviolet curable resin, a radical polymerization type or photocationic polymerization type material may be adopted.

A specific method of applying the barrier wall resin 13a to the end face of the optical sheet 5x will be described with reference to FIG.

First, a laminate 7 shown in FIG. The laminate 7 is obtained by alternately laminating the optical sheets 5x and the spacers 8. The spacer 8 may have lyophobic properties with respect to the barrier wall resin 13a. The lyophobic property may be obtained by performing an oil repellency treatment on the surface of the spacer 8.

Next, as shown in FIG. 5B, a barrier wall resin 13 a is applied to the side surface of the laminate 7. The barrier wall resin 13a may be applied by using a spray or a roller as an application device. Coating is performed on the entire circumference of the end face of the optical sheet 5x of the optical sheet 5x by rotating the coating device around the multilayer body 7 or by rotating the multilayer body 7 with respect to the coating device. May be.

By applying the barrier wall resin 13a to the optical sheet 5x by the above-described method, the optical sheet 5x may be damaged due to the thinness of the sheet, rather than applying to the optical sheet 5x one by one. And a reduction in tact increase. Further, when the spacer 8 is lyophobic with respect to the barrier wall resin 13a, the barrier wall resin 13a can be efficiently applied only to the end surface of the optical sheet 5x. For this reason, the amount of the barrier wall resin 13a required for application is reduced, leading to a reduction in the cost of applying the barrier wall resin 13a.

In the optical sheet 5a of this embodiment, barrier walls 13 different from the first and second barrier layers 11 and 12 formed on the upper and lower surfaces of the quantum dot layer 10 are formed on the end surfaces. For this reason, at the time of manufacturing the optical sheet 5a, the end treatment necessary for extending the first and second barrier layers 11 and 12 to the end face of the quantum dot layer 10 is not necessary. For this reason, the optical sheet 5a does not require a frame area necessary for processing such as bonding the upper and lower barrier layers. Further, the optical sheet 5a can be obtained relatively easily by laminating the quantum dot layer 10 and the first and second barrier layers 11 and 12 and forming the barrier wall 13 on the side surface.

[Embodiment 2]
6A and 6B are cross-sectional views showing the optical sheet 5b according to this embodiment. Each member constituting the optical sheet 5a and the optical sheet 5b has the same property, and may be formed of the same material. The optical sheet 5a and the optical sheet 5b differ in the position where the barrier wall 13 is formed.

That is, as shown in FIG. 6, the barrier wall 13 is formed on the end face of the quantum dot layer 10 between the first and second barrier walls 11 and 12. Further, the end face of the optical sheet 5 b is constituted by the first and second barrier walls 11 and 12 and the barrier wall 13.

A method for manufacturing the optical sheet 5b will be described with reference to FIGS. FIG. 7 is a flowchart showing an example of a method for manufacturing the optical sheet 5b, and FIGS. 8A to 8D are cross-sectional views showing an example of the method for manufacturing the optical sheet 5b in the order of steps.

First, similarly to the previous embodiment, the first barrier layer 11 and the quantum dot layer 10 are formed in order (S21, S22), and the stacked structure shown in FIG. 8A is obtained. Next, as shown in FIG. 8B, the quantum dot layer 10 is patterned (S23) to secure a region where the barrier wall 13 is formed. Note that the patterning of the quantum dot layer 10 is performed so that the quantum dot layer 10 having a predetermined size can be obtained when separated into individual pieces.

Subsequently, as shown in FIG. 8C, a barrier wall resin 13 a is applied to the region between the quantum dot layers 10 obtained by patterning the quantum dot layer 10. Thereafter, the barrier wall resin 13a is cured to obtain the barrier wall 13 (S24). From this state, similarly to the previous embodiment, the second barrier layer 12 is formed (S25), and the laminated structure shown in FIG. 8D is obtained. Finally, the optical sheet 5b is obtained by dividing into pieces of a predetermined size by dividing (S26). In addition, hardening of the resin 13a for barrier walls may be performed between formation of the 2nd barrier layer 12, and individualization by parting.

In the manufacturing method described with reference to FIG. 8, a method of patterning the quantum dot layer 10 after forming the quantum dot layer 10 is shown. However, in addition to this, even if the patterned quantum dot layer 10 is formed on the first barrier layer 11 formed in S21 by using an ink jet or a transfer plate (S27), the structure is the same. The optical sheet 5b can be obtained.

Also in the optical sheet 5b in the present embodiment, the edge processing necessary for extending the first and second barrier layers 11 and 12 to the end surface of the quantum dot layer 10 at the time of manufacture is not necessary. For this reason, the optical sheet 5b does not require a frame region necessary for processing such as bonding the upper and lower barrier layers. In the present embodiment, since the barrier wall 13 can be formed simultaneously with the formation of the quantum dot layer 10 and the first and second barrier layers 11 and 12, the optical sheet 5b has a reduced tact increase during manufacturing. Is possible. Further, since the barrier sheet 13 is formed between the first and second barrier layers 11 and 12 in the optical sheet 5b, the amount of the necessary barrier wall resin 13a is minimized, and the increase in cost is reduced. Can do. The optical sheet 5b of this embodiment can be replaced with the optical sheet 5a of the backlight unit 1a of the previous embodiment.

As shown in FIG. 6B, the barrier wall 13 may not be formed on the end surface of the optical sheet 5b as long as the barrier wall 13 is formed at a position covering the end surface 10e of the quantum dot layer 10. That is, the quantum dots 15 f and 16 f may exist outside the region surrounded by the first and second barrier layers 11 and 12 and the barrier wall 13. In this case, the region surrounded by the first and second barrier layers 11 and 12 and the barrier wall 13 of the quantum dot layer 10, that is, the quantum dot layer 10 inside the end face 10e may be used as an effective region. Is possible.

[Embodiment 3]
FIG. 9 is a cross-sectional view showing the backlight unit 1b according to the present embodiment. The backlight unit 1a includes a reflecting plate 2, a light guide plate 4 including a blue light emitting element 3, an optical sheet 5x, and a laminated body in which first and second lens sheets 6a and 6b are laminated in this order, A frame 9 and a barrier layer 13 are provided. The properties of each member constituting the laminate of the backlight unit 1b and the backlight unit 1a are the same except for the optical sheet, and may be formed of the same material. The blue light from the blue light emitting element 3 is projected onto the light guide plate 4 and irradiated from the upper and lower surfaces of the light guide plate 4 with substantially uniform light intensity at any position of the light guide plate 4.

The laminate of the backlight unit 1b according to the present embodiment includes the optical sheet 5x described above. That is, the laminate of the backlight unit 1b includes the optical sheet 5x in which the barrier layer is not formed on the end face and the quantum dot layer 10 is exposed. In the backlight unit 1 b, a frame 9 is formed on the entire circumference of the peripheral end portion on the upper surface of the reflection plate 2. The frame 9 is formed in the laminate of the backlight unit 1b at a distance from the upper layer member than the reflector 2. Further, a barrier wall 13 is formed between the frame 9 and the light guide plate 4 and the optical sheet 5x.

A method for manufacturing the backlight unit 1b will be described with reference to FIG. FIGS. 10A to 10C are cross-sectional views showing an example of a manufacturing method of the backlight unit 1b in the order of steps.

First, the reflecting plate 2 is formed, and the frame 9 is formed on the upper surface end of the reflecting plate 2. Next, the light guide plate 4 and the optical sheet 5x are sequentially formed while securing a space with the frame 9 that forms the barrier wall 13. As a result, the structure shown in FIG.

Subsequently, as shown in FIG. 10B, the barrier wall resin 13a is filled between the frame 9, the light guide plate 4, and the optical sheet 5x. At the position where the blue light emitting element 3 of the light guide plate 4 is formed, the barrier wall resin 13a may be filled between the frame 9 and the optical sheet 5x from above the blue light emitting element 3. As shown in FIG. 10B, the barrier wall resin 13a may be filled with a dispenser. Thus, it is preferable to fill the barrier wall resin 13a in a state where the optical sheet 5x is the uppermost layer of the laminate. Thereby, since the barrier wall resin 13a can be filled in a state where the interface between the sheets is minimized, the possibility that the barrier wall resin 13a enters between the sheets can be reduced.

Thereafter, by laminating the first and second lens sheets 6a and 6b on the optical sheet 5x, the structure shown in FIG. 10C is obtained. By curing the barrier wall resin 13a to obtain the barrier wall 13, the backlight unit 1b is obtained. In this embodiment, when the barrier wall resin 13a is an ultraviolet curable resin, it is possible to reduce the possibility that the sheet is deformed due to expansion or contraction of the sheet and the resin enters between the sheets.

Also in the backlight unit 1b in this embodiment, since the barrier wall 13 is formed at a position covering the end face of the quantum dot layer 10, an effect of preventing the deactivation of the quantum dots in the quantum dot layer 10 can be obtained. Moreover, the backlight unit 1b in this embodiment is obtained by forming the barrier wall 13 after laminating | stacking the optical sheet 5x with another member. For this reason, the backlight unit 1b can be manufactured by using the conventional apparatus which manufactures the optical sheet 5x, and adding the process of apply | coating the barrier wall 13. FIG. For this reason, the necessity for introducing a new device is reduced, and the manufacturing cost of the backlight unit 1b is reduced. The optical sheet 5x may be obtained by the manufacturing method described in the previous embodiment.

[Embodiment 4]
FIG. 11 is a cross-sectional view showing the optical sheet 5c according to this embodiment. The properties of the members constituting the optical sheet 5b and the optical sheet 5c are the same except for the scattering material 17, and may be formed of the same material. The optical sheet 5 c is different from the optical sheet 5 b in that it includes a quantum dot layer 10 a having microcapsules 17 a instead of the scattering material 17.

In this embodiment, the microcapsule 17a has an outer shell, and the outer shell includes a content including a material constituting the barrier wall 13. The microcapsule 17a causes the contents to elute out of the outer shell by breaking the outer shell. The microcapsules 17a are dispersed in the resin 14 of the quantum dot layer 10a. In the present embodiment, the content eluted from the outer shell of the microcapsule 17a penetrates into the resin 14 of the quantum dot layer 10a and then hardens, so that the barrier wall 13 is positioned at a position covering the end face of the quantum dot layer 10a. Form. The content may be a resin such as an epoxy resin, a siloxane resin, or an olefin resin.

From the viewpoint of improving the diffusion efficiency and permeability of the optical sheet 5c, the particle size of the microcapsules 17a is preferably 10 μm or less, more preferably 5 μm or less. Further, from the viewpoint of securing a sufficient amount of the contents when the barrier wall 13 is formed, the particle size of the microcapsules 17a is preferably 0.5 μm or more, and more preferably 1 μm or more.

Furthermore, from the viewpoint of improving the permeability and strength of the optical sheet 5c, the addition amount of the microcapsules 17a is preferably 5 wt% or less, more preferably 3 wt% or less with respect to the resin 14. Further, from the viewpoint of securing a sufficient amount of the contents at the time of forming the barrier wall 13, the addition amount of the microcapsule 17 a is preferably 0.5 wt% or more, more preferably 1 wt% or more with respect to the resin 14. It is.

The microcapsule 17 a has the property of scattering incident light, like the scattering material 17. The quantum dot layer 10 may further include a scattering material 17. At this time, it is preferable to adjust the addition amount of the scattering material 17 so that the addition amount of the microcapsule 17a satisfies the above-described conditions. Furthermore, it is preferable to determine the particle size of the scattering material 17 as appropriate in consideration of the addition amount of the microcapsules 17a and the wavelength dispersion of the scattering material 17.

An example of a specific method for eluting the contents from the outer shell of the microcapsule 12a in the present embodiment will be described with reference to FIG. 12A to 12C are enlarged cross-sectional views showing an example of a method for manufacturing the optical sheet 5c in the order of steps. The microcapsule 17a of the optical sheet 5c has thermal responsiveness. The microcapsule 17a has a property of reacting to heat and breaking the outer shell.

First, the quantum dot layer 10a and the first and second barrier layers 11 and 12 are laminated to obtain a laminated structure shown in FIG. The manufacturing method so far may be the same as the manufacturing method of the optical sheet 5a described above. Next, heat treatment is performed on the microcapsules 17a in the entire circumference of the peripheral edge of the quantum dot layer 10a to break the outer shell of the microcapsules 17a. The heat treatment may be performed by irradiating the microcapsule 17a with laser as shown in FIG. Finally, the barrier wall 13 is formed from the contents eluted from the outer shell to obtain the optical sheet 5c shown in FIG.

The optical sheet 5c in the present embodiment does not require the application of the barrier wall resin 13a or the patterning of the quantum dot layer 10a at the time of manufacture, and can be performed by performing an additional process on the quantum dot layer 10a. For this reason, it leads to simplification of the manufacturing process of the optical sheet 5c more.

[Embodiment 5]
FIGS. 13A to 13C are enlarged cross-sectional views showing an example of a manufacturing method of the optical sheet 5d in this embodiment in the order of steps. The optical sheet 5d has the same structure as the optical sheet 5c except that the optical sheet 5d includes a quantum dot layer 10b having microcapsules 17b having pressure responsiveness instead of the quantum dot layer 10a of the optical sheet 5c. The microcapsule 17b has a property of reacting to an external pressure and breaking the outer shell.

First, the quantum dot layer 10b and the first and second barrier layers 11 and 12 are laminated to obtain a laminated structure shown in FIG. The manufacturing method so far may be the same as the manufacturing method of the optical sheet 5c described above. Next, pressure treatment is performed on the microcapsules 17b around the entire circumference of the quantum dot layer 10b to break the outer shell of the microcapsules 17b. The pressurizing process may be a process of dividing the laminated structure with a cutter so as to obtain an optical sheet 5d having a predetermined size as shown in FIG. Finally, the barrier wall 13 is formed from the contents eluted from the outer shell to obtain the optical sheet 5d shown in FIG. In addition, the said division | segmentation may be performed using the punching by a type | mold.

The optical sheet 5d in the present embodiment does not require separate application of the barrier wall resin 13a or patterning of the quantum dot layer 10a at the time of manufacture, and can be performed by subjecting the quantum dot layer 10a to additional pressure treatment. . Moreover, the optical sheet 5d can be obtained without increasing the number of steps from the conventional manufacturing method by making the pressurizing process into a dividing process for individualization.

[Embodiment 6]
14A to 14C are enlarged cross-sectional views showing an example of a method for manufacturing the optical sheet 5e in the present embodiment in the order of steps. The optical sheet 5e has the same structure as the optical sheet 5c except that it includes a quantum dot layer 10c having microcapsules 17c having moisture responsiveness instead of the quantum dot layer 10a of the optical sheet 5c. The microcapsule 17c has a property of reacting to contact with water and breaking the outer shell.

First, the quantum dot layer 10c and the first and second barrier layers 11 and 12 are laminated to obtain a laminated structure shown in FIG. The manufacturing method so far may be the same as the manufacturing method of the optical sheet 5c described above. Next, as shown in FIG. 14 (b), moisture is applied to the quantum dot layer 10c from the entire circumference of the peripheral end portion to bring the microcapsule 17c into contact with moisture, thereby breaking the outer shell of the microcapsule 17c. The moisture may be moisture that penetrates into the quantum dot layer 10c from the exposed end face of the quantum dot layer 10c over time. Finally, the barrier wall 13 is formed from the contents eluted from the outer shell to obtain the optical sheet 5e shown in FIG.

The optical sheet 5e in the present embodiment does not require separate application of the barrier wall resin 13a or patterning of the quantum dot layer 10a at the time of manufacture, and can be performed by applying additional moisture to the quantum dot layer 10a. Further, moisture can be applied by leaving the optical sheet 5e in a state where the end face of the quantum dot layer 10c is exposed. In this case, the optical sheet 5d can be obtained without performing additional processing during manufacturing.

FIG. 15 is a block diagram showing an optical sheet manufacturing apparatus used in the above-described embodiments. As shown in FIG. 15, the optical sheet manufacturing apparatus 30 includes a film forming apparatus 32, a barrier wall forming apparatus 33, a cutting apparatus 34, and a controller 31 that controls these apparatuses.

The film forming apparatus 31 under the control of the controller 31 forms a quantum dot layer and a barrier layer. The barrier wall forming device 32 under the control of the controller 31 forms a barrier wall on the end face of the quantum dot layer. The barrier wall forming device 32 may be a device that applies a barrier wall resin to the end face of the quantum dot layer, or may be a device that breaks the outer shell of the microcapsule in the quantum dot layer. The cutting device 33 under the control of the controller 31 cuts the stacked structure of the quantum dot layer and the barrier layer.

[Summary]
The optical sheet of aspect 1 includes a quantum dot layer having quantum dots, a first barrier layer below the quantum dot layer, a second barrier layer above the quantum dot layer, and an end face of the quantum dot layer And a barrier wall for covering.

In aspect 2, the barrier wall covers an interface edge between the quantum dot layer and the first barrier layer and an interface edge between the quantum dot layer and the second barrier layer.

In aspect 3, the barrier wall is provided between the first and second barrier layers.

In aspect 4, the barrier wall contains an ultraviolet curable resin.

In aspect 5, the quantum dot layer includes a microcapsule having a content containing a material constituting the barrier wall inside an outer shell.

In aspect 6, the contents are eluted from the outer shell by the fracture of the outer shell.

In aspect 7, the outer shell breaks in response to heat.

In aspect 8, the outer shell breaks in response to external pressure.

In aspect 9, the outer shell breaks in response to contact with water.

In aspect 10, the microcapsules scatter light incident on the microcapsules.

The backlight unit according to aspect 11 includes the optical sheet.

In the twelfth aspect, a frame is further provided, and the barrier wall is provided between the frame and the quantum dot layer.

The method for producing an optical sheet according to aspect 13 includes a stacked structure of a quantum dot layer having quantum dots, a first barrier layer below the quantum dot layer, and a second barrier layer above the quantum dot layer. A stacking step for manufacturing, and a barrier wall forming step for forming a barrier wall covering the end face of the quantum dot layer.

The aspect 14 further includes a dividing step of dividing the laminated structure into a predetermined size.

In aspect 15, the dividing step is performed after the laminating step and before the barrier wall forming step.

In Aspect 16, in the barrier wall forming step, spacers having lyophobic properties with respect to the barrier wall material and the laminated structure are alternately laminated, and the barrier wall material is applied.

In aspect 17, the dividing step is performed after the laminating step and the barrier wall forming step.

In Aspect 18, the quantum dot layer includes a microcapsule having a content constituting the barrier wall inside the outer shell, and in the barrier wall forming step, the outer shell is broken, The barrier wall is formed by the eluted contents.

In aspect 19, in the barrier wall forming step, the outer shell is broken by heat.

In aspect 20, in the barrier wall forming step, the outer shell is broken by external pressure.

In aspect 21, in the barrier wall forming step, the outer shell is broken by contact with water.

The method for manufacturing the backlight unit according to aspect 22 includes the method for manufacturing the optical sheet.

The aspect 23 further includes a frame forming step of forming a frame, and in the barrier wall forming step, the material of the barrier wall is filled between the frame and the laminated structure.

The optical sheet manufacturing apparatus according to aspect 24 includes a quantum dot layer having quantum dots, a first barrier layer below the quantum dot layer, a second barrier layer above the quantum dot layer, and the quantum dots. And a barrier wall covering the end face of the layer.

The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention. Furthermore, a new technical feature can be formed by combining the technical means disclosed in each embodiment.

1a and 1b Backlight unit 5a to 5d and 5x Optical sheet 8 Spacer 9 Frame 10 and 10a to 10c Quantum dot layer 11 First barrier layer 12 Second barrier layer 13 Barrier wall 13a Barrier wall resin 17 Scattering material 17a to 17c Micro capsule

Claims (24)

A quantum dot layer having quantum dots; a first barrier layer below the quantum dot layer; a second barrier layer above the quantum dot layer; and a barrier wall covering an end face of the quantum dot layer. Optical sheet. The optical sheet according to claim 1, wherein the barrier wall covers an edge of an interface between the quantum dot layer and the first barrier layer and an edge of an interface between the quantum dot layer and the second barrier layer. The optical sheet according to claim 1 or 2, wherein the barrier wall is provided between the first barrier layer and the second barrier layer. The optical sheet according to any one of claims 1 to 3, wherein the barrier wall includes an ultraviolet curable resin. The optical sheet according to any one of claims 1 to 4, wherein the quantum dot layer includes a microcapsule having a content containing a material constituting the barrier wall inside an outer shell. 6. The optical sheet according to claim 5, wherein the contents are eluted from the outer shell by the fracture of the outer shell. The optical sheet according to claim 6, wherein the outer shell breaks in response to heat. The optical sheet according to claim 6, wherein the outer shell breaks in response to an external pressure. The optical sheet according to claim 5 or 6, wherein the outer shell breaks in response to contact with water. 10. The optical sheet according to claim 5, wherein the microcapsule scatters light incident on the microcapsule. A backlight unit comprising the optical sheet according to any one of claims 1 to 10. The backlight unit according to claim 11, further comprising a frame, wherein the barrier wall is provided between the frame and the quantum dot layer. A stacking process for manufacturing a stacked structure of a quantum dot layer having quantum dots, a first barrier layer lower than the quantum dot layer, and a second barrier layer higher than the quantum dot layer;
And a barrier wall forming step of forming a barrier wall that covers an end face of the quantum dot layer. The method for producing an optical sheet according to claim 13, further comprising a dividing step of dividing the laminated structure into a predetermined size. The method for producing an optical sheet according to claim 14, wherein the dividing step is performed after the laminating step and before the barrier wall forming step. The optical sheet according to claim 15, wherein in the barrier wall forming step, spacers having lyophobic properties with respect to the material of the barrier wall and the laminated structure are alternately laminated, and the material of the barrier wall is applied. Production method. The method for producing an optical sheet according to claim 14, wherein the dividing step is performed after the laminating step and the barrier wall forming step. The quantum dot layer includes a microcapsule having a content constituting the barrier wall inside an outer shell,
The method for producing an optical sheet according to any one of claims 13 to 17, wherein, in the barrier wall forming step, the outer shell is broken and the barrier wall is formed by the contents eluted from the outer shell. The method for producing an optical sheet according to claim 18, wherein the outer shell is broken by heat in the barrier wall forming step. The method for producing an optical sheet according to claim 18, wherein in the barrier wall forming step, the outer shell is broken by an external pressure. The method for producing an optical sheet according to claim 18, wherein in the barrier wall forming step, the outer shell is broken by contact with water. A method for manufacturing a backlight unit comprising the method for manufacturing an optical sheet according to any one of claims 13 to 21. A frame forming step of forming a frame;
The method for manufacturing a backlight unit according to claim 22, wherein in the barrier wall forming step, a material for the barrier wall is filled between the frame and the laminated structure. A quantum dot layer having quantum dots, a first barrier layer below the quantum dot layer, a second barrier layer above the quantum dot layer, and a barrier wall that covers an end face of the quantum dot layer are formed Optical sheet manufacturing equipment.

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