Display device, light-emitting control structure for display device and preparation method of light-emitting control structure

Abstract

The invention discloses a display device, a light-emitting control structure for the display device and a preparation method of the light-emitting control structure. The light-emitting control structure for the display device comprises a light-emitting regulation and control layer and a filling layer located on the light-emitting regulation and control layer. The light-emitting regulation and control layer comprises a plurality of light-emitting regulation and control units, each light-emitting regulation and control unit is located on the light-emitting side of the light-emitting area, and the filling layer is of an integrated structure and covers all the light-emitting regulation and control units; the included angle between the light-emitting regulation and control unit and the horizontal line is defined as an oblique angle alpha, and the oblique angle alpha of the light-emitting regulation and control unit ranges from 0 degree to 60 degrees. The light emitting regulation and control units and the light emitting areas are in one-to-one correspondence in the vertical direction, and CRA brightness loss and optical crosstalk risks caused by the non-correspondence problem are reduced.

Description

Technical Field

[0001] The present invention relates to the field of near-eye display technology, and in particular to a display device, a light output control structure for a display device, and a preparation method thereof. Background Art

[0002] The near-eye display system uses an optical magnification system such as an optical machine to magnify the image in the micro-display screen and transmit it to the human eye. In the existing near-eye display system, since the display screen is smaller than the final image, the problem of low brightness at a large viewing angle during the magnification process has always been a problem that needs to be solved urgently.

[0003] The chief ray angle (CRA) refers to the angle with the strongest luminous intensity between 0 and 180 degrees. Fig. 9 As shown in the figure, the CRA of general display screens is 0°, and the screen is smaller than the optical machine system. Therefore, the edge of the optical machine can only collect light at the oblique angle of the edge of the screen. Since this light is not at the main angle, the brightness is low, resulting in low brightness at the edge of the final display. Therefore, for the application requirements of such products, different positions of the display screen are required to have different CRAs. The usual method is to offset the relative positions of the MLA (Micro Lens Array), CF (Color Filter) and the anode, and enhance the oblique angle light intensity through the optical refraction effect of the microlens, such as Fig.10 As shown, 11 is the color filter layer, 12 is the anode, and 13 is the microlens array. However, this method has certain defects. The native luminescence distribution of OLED and LED is a Lambertian distribution, that is, the luminescence is strongest at the normal viewing angle. The offset of MLA and CF will inevitably lead to the loss of normal viewing angle light in some luminous areas. In the general scheme, the MLA and CF offset guides the CRA offset scheme. As the offset angle increases, there will definitely be a problem that the MLA unit cannot completely cover the luminous area of ​​the luminous unit. That is, part of the light of the sub-pixel cannot be collected by the microlens and CF of the sub-pixel, resulting in CRA brightness loss, and it may even be collected by the CF and microlens of the neighboring pixel to cause optical crosstalk, resulting in a decrease in brightness, such as Fig.11 shown.

[0004] In addition, in the field of microdisplay, the MLA spacing is generally between 0.4 and 1um, which means that the MLA can only be offset toward the edge of the screen, and the maximum inward offset is 0.5um, which is very limited. Therefore, even if the CRA at the edge of the screen is offset, the luminous intensity under this CRA must be less than the normal viewing angle intensity, which cannot completely meet the actual application needs. Summary of the invention

[0005] Technical purpose: To address the defect in the prior art that the actual light-emitting area does not correspond to CF and MLA, resulting in CRA brightness loss, the present invention discloses a display device, a light output control structure for a display device, and a preparation method thereof, to achieve CRA regulation.

[0006] Technical solution: In order to achieve the above technical objectives, the present invention adopts the following technical solution.

[0007] A light emission control structure for a display device, comprising: a light emission regulation layer and a filling layer located above the light emission regulation layer;

[0008] The light emission control layer includes several light emission control units, each of which is located on the light emission side of the light emitting area. The filling layer is an integrated structure, covering all the light emission control units. The angle between the light emission control unit and the horizontal line is defined as the oblique angle α, and the range of the oblique angle α of the light emission control unit is 0 to 60°.

[0009] A method for preparing a light emission control structure for a display device, for preparing the above-mentioned light emission control structure for a display device, comprises the following steps:

[0010] S1: providing a display device substrate;

[0011] S2: coating a light emission control layer material on a display device substrate;

[0012] S3: preparing a light output regulation layer template according to the oblique angle α of each light output regulation unit, wherein the oblique angle α of the light output regulation unit is obtained according to the relationship between the oblique angle α and the sub-pixel output light CRA corresponding to the light output regulation unit; and performing nano-imprinting on the light output regulation layer material using the light output regulation layer template;

[0013] S4: after demolding, the light emission regulation layer template is taken out, and the remaining light emission regulation layer material forms a light emission regulation layer;

[0014] S5: coating a filling layer on the light emission regulating layer.

[0015] A display device includes a display device substrate and a light output control structure, wherein the display device substrate includes a plurality of pixel units, each pixel unit includes a plurality of sub-pixels; an anode electrode is provided at the bottom of each sub-pixel; the sub-pixel includes a light-emitting element, and a color filter layer and a light output control structure are sequentially provided on the light output side of the light-emitting element in a direction away from the light-emitting element; the light output control structure is a light output control structure for a display device as described above.

[0016] Beneficial effect: In the present invention, the light emission control unit and the light emitting area correspond one-to-one in the vertical direction, reducing the CRA brightness loss and optical crosstalk risk caused by the mismatch problem; on the other hand, when the refractive index is fixed, the CRA is only related to the bevel angle α of the light emission control layer. Controlling α can realize the CRA deflection toward the edge of the screen or toward the center of the screen. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of a display device according to an embodiment of the present invention;

[0018] Figure 2 A schematic diagram of light transmission according to an embodiment of the present invention;

[0019] Figures 3 to 7 It is a schematic flow chart of a method for preparing a light output control structure for a display device according to an embodiment of the present invention;

[0020] Figure 8 Schematic diagram of the preparation process of the nanoimprint template according to an embodiment of the present invention;

[0021] Fig. 9 It is a schematic diagram of CRA in the prior art;

[0022] Fig.10 It is a schematic diagram of the display screen structure in the prior art;

[0023] Fig.11 It is a schematic diagram of the MLA and CF offset-guided CRA offset solution in the prior art;

[0024] Among them, 1 is a light emission control layer, 101 is a light emission control unit, 2 is a filling layer, 3 is a glass bonding adhesive, 4 is glass, 5 is air, 6 is a display device substrate, 11 is a color filter layer, 12 is an anode, and 13 is a microlens array. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0026] As attached Figure 1 As shown, a light emission control structure for a display device in this embodiment includes a light emission regulation layer 1 and a filling layer 2 located on the light emission regulation layer 1, and the filling layer 2 is a high refractive index filling layer;

[0027] The light emission control layer 1 includes a plurality of light emission control units 101, each of which is located at the light emission side of the light emitting area, and the filling layer 2 is an integrated structure, covering all light emission control units 101; the angle between the light emission control unit and the horizontal line is defined as the bevel angle α, the bevel angle α of the light emission control unit ranges from 0 to 60°, and the bevel angle α of each light emission control unit is set according to the CRA requirement of the sub-pixel emission light corresponding to the light emission control unit. The relationship between the bevel angle α of each light emission control unit and the CRA of the sub-pixel emission light corresponding to the light emission control unit is:

[0028] CRA=arcsin(sin(α-arcsin(n1·sinα / n2))·n2)

[0029] Wherein, n1 is the refractive index of the light output control unit, and n2 is the refractive index of the filling layer.

[0030] The refractive index n1 of the light output control unit generally ranges from 1.35 to 1.55, and the refractive index n2 of the filling layer generally ranges from 1.65 to 1.95.

[0031] The material of the light emission regulating layer is organic glue, such as acrylate and polymethyl methacrylate (PMMA).

[0032] The material of the filling layer can be organic glue, such as acrylate, polymethyl methacrylate (PMMA); it can also be inorganic material, such as SION, AL2O3.

[0033] The light emission control structure for a display device of the present embodiment can adjust the CRA of a sub-pixel between 0° and 50°.

[0034] The light emission control layer is prepared by a nano-imprinting process or an electron beam lithography process, and the high-refractive index filling layer is prepared by a spin coating or inkjet printing process.

[0035] The following is a derivation process of the relationship between the oblique angle α of each light emission control unit and the sub-pixel emission light CRA corresponding to the light emission control unit:

[0036] As attached Figure 2As shown, in actual use, a glass bonding glue 3 and a glass 4 are provided above the light output control structure of the display device, and then the glass 4 contacts the air 5; after the light is emitted from the sub-pixel, it enters the light output control unit, and after being refracted at the upper interface of the light output control unit, it enters the filling layer, and in the light output control unit, the angle between the light and the upper interface of the light output control unit in the vertical direction is defined as θ1; in the filling layer, the angle between the light and the upper interface of the light output control unit in the vertical direction is defined as θ2; after the light is refracted from the upper interface of the filling layer, it enters the glass bonding glue, and in the filling layer, the angle between the light and the upper interface of the filling layer in the vertical direction is defined as θ3; In the adhesive, the angle between the light and the upper interface of the filling layer is θ4; similarly, in the glass adhesive, the angle between the light and the upper interface of the glass adhesive is θ5; in the glass, the angle between the light and the upper interface of the glass adhesive is θ6; in the glass, the angle between the light and the upper interface of the glass is θ7; in the air, the angle between the light and the upper interface of the glass is θ8; θ8 is also the sub-pixel output light CRA corresponding to the light output control unit; the refractive indices of the light output control unit, the filling layer, the glass adhesive, the glass, and the air are defined as n1, n2, n3, n4, and n5, respectively;

[0037] Since the three interfaces among the filling layer, glass bonding adhesive, glass, and air are all planes, θ6 = θ7, θ4 = θ5, and θ4 = θ5;

[0038] According to the refractive index formula sinθ8·n5=sinθ7·n4=sinθ6·n4=sinθ5·n3=sinθ4·n3=sinθ3·n2;

[0039] The outgoing light is vertical, so it can be deduced that θ1 = α, θ3 = α-θ2; it is generally believed that the refractive index of air n5 = 1;

[0040] Therefore, it can be deduced that: output light CRA = arcsin (sin (α - arcsin (n1 · sin α / n2)) · n2)

[0041] It is worth noting that due to the design requirements of the optical module, the α angle of each mother pixel is different, and the α angle of the sub-pixels in each mother pixel is the same. Among them, the mother pixel refers to a pixel collection including three sub-pixels of red, green and blue, that is, a mother pixel includes a red sub-pixel, a green sub-pixel and a blue sub-pixel.

[0042] For example, from the cross-sectional view, the rightward offset is defined as +, and the leftward offset is defined as -; the angle α formed by the clockwise rotation of the upper edge of the light-emitting control unit and the horizontal line is +, and the angle α formed by the counterclockwise rotation of the upper edge of the light-emitting control unit and the horizontal line is -. The refractive index of the light-emitting control unit is set to 1.4, and the refractive index of the filling layer is set to 1.75; the CRA of the mother pixel in the center of the screen is required to be 0°, the CRA of the mother pixel on the far right is required to be 15°, and the CRA changes evenly from the center to the far right of the screen; the number of mother pixels in the horizontal direction of the screen is 720. Then the mother pixel in the center α is 0°, the mother pixel on the far right α is 38°, the 100th mother pixel α is 11.8°, and the 200th mother pixel α is 22.8°.

[0043] This embodiment also discloses a method for preparing a light emission control structure for a display device, which is used to prepare the above-mentioned light emission control structure for a display device, comprising the following steps:

[0044] S1: As attached Figure 3 As shown, a display device substrate is provided;

[0045] S2: As attached Figure 4 As shown, a light emission control layer material is coated on a display device substrate. In this embodiment, the light emission control layer material is nano-imprint glue, which is a kind of organic glue and is used to prepare the light emission control layer;

[0046] S3: As attached Figure 5 As shown, a light output regulation layer template, i.e., a nanoimprint template, is prepared according to the oblique angle α of each light output regulation unit, wherein the oblique angle α of the light output regulation unit is obtained according to the relationship between the oblique angle α and the sub-pixel output light CRA corresponding to the light output regulation unit; and the light output regulation layer material is nanoimprinted using the light output regulation layer template;

[0047] S4: As attached Figure 6 As shown, after demoulding, the light emission regulating layer template is taken out, and the remaining light emission regulating layer material forms the light emission regulating layer;

[0048] S5: As attached Figure 7 As shown, a filling layer is coated on the light emission regulating layer.

[0049] As attached Figure 8 As shown, the preparation process of the light emission control layer template, i.e., the nanoimprint template, of this embodiment includes:

[0050] S1-1: coating an electron beam photoresist on a display device substrate;

[0051] S1-2: Use electron beam grayscale exposure, and the exposure shape is completely consistent with the final light-emitting control layer shape design;

[0052] S1-3: Developing a photoresist pattern, the photoresist pattern is the morphology of the light emission control layer;

[0053] S1-4: PDMS (dimethylsiloxane) is coated on the photoresist pattern and cured; dimethylsiloxane is a polymer material;

[0054] S1-5: Remove the final PDMS template, thus forming the final light-emitting control layer template, that is, the nanoimprint template.

[0055] As attached Figure 1 As shown, a display device includes a display device substrate 6 and a light output control structure, the display device substrate 6 includes a plurality of pixel units, each pixel unit includes a plurality of sub-pixels; an anode electrode is provided at the bottom of each sub-pixel; the sub-pixel includes a light-emitting element, and a color filter layer and a light output control structure are sequentially provided on the light output side of the light-emitting element in a direction away from the light-emitting element; the light output control structure is a light output control structure for a display device as described above; the light-emitting element includes a plurality of light-emitting areas, and the light-emitting areas correspond one-to-one to the light output control units.

[0056] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A light output control structure for a display device, characterized in that: include: A light emission regulating layer and a filling layer located above the light emission regulating layer; The light emission control layer includes a plurality of light emission control units, each of which is located at the light emission side of the light emitting area, and the filling layer is an integrated structure, covering all the light emission control units; The angle between the light output control unit and the horizontal line is defined as an oblique angle α, and the range of the oblique angle α of the light output control unit is 0 to 60°.

2. The light output control structure for a display device according to claim 1, characterized in that: The oblique angle α of each light output regulation unit is set according to the CRA requirement of the sub-pixel output light corresponding to the light output regulation unit.

3. The light output control structure for a display device according to claim 2, characterized in that: The relationship between the oblique angle α of each light emission control unit and the sub-pixel emission light CRA corresponding to the light emission control unit is: CRA=arcsin(sin(α-arcsin(n1·sinα / n2))·n2) Wherein, n1 is the refractive index of the light output control unit, and n2 is the refractive index of the filling layer.

4. The light output control structure for a display device according to claim 1, characterized in that: The refractive index n1 of the light output regulation unit ranges from 1.35 to 1.55, and the refractive index n2 of the filling layer ranges from 1.65 to 1.

95.

5. The light output control structure for a display device according to claim 1, characterized in that: The material of the light emission regulating layer is organic glue, and the material of the filling layer is organic glue or inorganic material.

6. A method for preparing a light output control structure for a display device, used for preparing a light output control structure for a display device as claimed in any one of claims 1 to 5, characterized in that: The following steps are involved: S1: providing a display device substrate; S2: coating a light emission control layer material on a display device substrate; S3: preparing a light output regulation layer template according to the oblique angle α of each light output regulation unit, wherein the oblique angle α of the light output regulation unit is obtained according to the relationship between the oblique angle α and the sub-pixel output light CRA corresponding to the light output regulation unit; Nano-imprinting the light emission regulation layer material using the light emission regulation layer template; S4: after demolding, the light emission regulation layer template is taken out, and the remaining light emission regulation layer material forms a light emission regulation layer; S5: coating a filling layer on the light emission regulating layer.

7. The method for preparing a light output control structure for a display device according to claim 6, characterized in that: The preparation process of the light emission control layer template includes: S1-1: coating an electron beam photoresist on a display device substrate; S1-2: Use electron beam grayscale exposure, and the exposure shape is completely consistent with the final light-emitting control layer shape design; S1-3: Developing a photoresist pattern, the photoresist pattern is the morphology of the light emission control layer; S1-4: Use PDMS to coat the photoresist pattern and cure it; S1-5: Remove the final PDMS template to form the final light-emitting control layer template.

8. A display device, characterized in that: It includes a display device substrate and a light output control structure, the display device substrate includes a plurality of pixel units, each pixel unit includes a plurality of sub-pixels; an anode electrode is provided at the bottom of each sub-pixel; the sub-pixel includes a light-emitting element, and a color filter layer and a light output control structure are sequentially provided on the light output side of the light-emitting element in a direction away from the light-emitting element; the light output control structure is a light output control structure for a display device as described in any one of claims 1-5.

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