Optical film and display device

Abstract

A display device comprises a display module and a lighting module. The lighting module is arranged on the display surface of the display module and comprises a light source, a light guide plate and an optical film. The optical film is disposed between the display module and the light guide plate, and includes a substrate layer and a microstructure layer. The microstructure layer is arranged between the surface of the substrate layer and the light guide plate and comprises a plurality of microstructures, and each microstructure comprises a first surface and a second surface which are oppositely arranged. The first surface and the reference surface form a first angle, the second surface and the reference surface form a second angle, the reference surface is parallel to the surface of the substrate layer, and the first angle and the second angle are larger than or equal to 40 degrees and smaller than or equal to 90 degrees. The display device with the optical film can also have high structural reliability under the condition of front light illumination.

Description

Technical Field

[0001] The invention relates to an optical film and a display device. Background Art

[0002] In a front-light display device, a light source and a light guide plate are usually arranged on one side of the display surface of the display module, and a pattern is arranged on the lower surface of the light guide plate. After the light emitted by the light source enters the light guide plate, it is first reflected and / or scattered by the pattern and reaches the display surface of the display module, and then reflected by the display surface and enters the user's eyes, making the image of the front-light display device visible. On the other hand, the light guide plate and the display module need to be bonded together by adhesive. If the above bonding is performed in a whole-surface bonding manner, the adhesive will contact the pattern of the light guide plate, resulting in a decrease in the pattern's ability to reflect / scatter light. If the above bonding is performed in a frame bonding manner, the reliability of the display device will be reduced. Summary of the invention

[0003] The present invention provides an optical film and a display device. The optical film can be used in a front light display device. The display device having the optical film can have a high structural reliability even under the condition of front light illumination.

[0004] Other purposes and advantages of the present invention can be further understood from the technical features disclosed in the present invention.

[0005] To achieve one or part or all of the above purposes or other purposes, according to one embodiment of the present invention, an optical film is provided, comprising a substrate layer and a microstructure layer. The microstructure layer is disposed on the surface of the substrate layer, and the microstructure layer comprises a plurality of microstructures, wherein each microstructure comprises a first surface and a second surface arranged opposite to each other. The first surface and a reference plane are sandwiched at a first angle, and the second surface and the reference plane are sandwiched at a second angle, the reference plane is parallel to the surface of the substrate layer, and the angle of the first angle and the angle of the second angle are greater than or equal to 40 degrees and less than or equal to 90 degrees.

[0006] According to one embodiment of the present invention, a display device is provided, including a display module and a lighting module. The display module has a display surface. The lighting module is arranged on the display surface of the display module, and includes a light source, a light guide plate, and an optical film. The light source is arranged on a first side of the light guide plate. The optical film is arranged between the display module and the light guide plate, and includes a base layer and a microstructure layer. The microstructure layer is arranged between the surface of the base layer and the light guide plate, and includes a plurality of microstructures, wherein each microstructure includes a first surface and a second surface that are arranged oppositely. The first surface and a reference plane are sandwiched at a first angle, the second surface and the reference plane are sandwiched at a second angle, the reference plane is parallel to the surface of the base layer, and the angle of the first angle and the angle of the second angle are greater than or equal to 40 degrees, and less than or equal to 90 degrees.

[0007] Based on the above, the optical film provided by the embodiment of the present invention has a microstructure, each microstructure has a first surface and a second surface, the first surface and the reference plane are at a first angle, and the second surface and the reference plane are at a second angle. When the display surface of the display module of the display device is parallel to the reference plane, and the lighting module of the display device is configured with a light source on the side of the light guide plate, the light emitted by the light source will first be reflected by the first surface and / or the second surface and reach the display surface of the display module, and then reflected by the display surface into the user's eyes, so that the display image of the display device is visible. Compared with the known technology of configuring a pattern on the lower surface of the light guide plate to reflect light, the embodiment of the present invention configures the microstructure in the optical film, and the light guide plate, the optical film and the display module can be stacked in a whole-surface bonding manner, so that the display device can have a higher reliability.

[0008] In order to make the above features and advantages of the present invention more clearly understood, embodiments are given below with reference to the accompanying drawings for detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic diagram of an optical film according to a first embodiment of the present invention.

[0010] Figure 2 is a schematic diagram of an optical film according to a second embodiment of the present invention.

[0011] Figure 3A yes Figure 1 Schematic diagram of the cross-section of an optical film.

[0012] Figure 3B yes Figure 3A Schematic cross-section of the microstructure.

[0013] Figure 3C is a schematic cross-sectional view of an optical film according to a third embodiment of the present invention.

[0014] Figure 4 is a schematic cross-sectional view of a display device according to an embodiment of the present invention.

[0015] Figure 5 is a schematic cross-sectional view of a display device according to another embodiment of the present invention.

[0016] Figure 6 , Figure 7 as well as Figure 8 is a schematic diagram of the brightness of a display device according to an embodiment of the present invention.

[0017] Fig. 9 is a schematic cross-sectional view of a microstructure according to an embodiment of the present invention.

[0018] Description of reference numerals:

[0019] 10, 20: Display device

[0020] 100, 200, 300, 400: Optical film

[0021] 101: Light Source

[0022] 102: Light guide plate

[0023] 110, 210: Lighting module

[0024] 120: Display module

[0025] 120D: Display surface

[0026] BL: Basal layer

[0027] D1, D2, D3: Direction

[0028] DS: Datum surface

[0029] H: Height

[0030] IL: Light

[0031] ML: Microstructure layer

[0032] MC: Microstructured connection layer

[0033] MS, MS1, MS2, MS3: Microstructure

[0034] OCA1, OCA2: Adhesive layer

[0035] S1: Side 1

[0036] S2: Side 2

[0037] S3: The third side

[0038] S4: The fourth side

[0039] S5: The Fifth Side

[0040] SB1, SB2: Transparent substrate layer

[0041] SD1, SD2, SD3, SD4: Side

[0042] W: Width

[0043] θ1: first angle

[0044] θ2: Second angle

[0045] θ3, θ4: angle. DETAILED DESCRIPTION

[0046] The above-mentioned other technical contents, features and effects of the present invention will be clearly presented in the following detailed description of a preferred embodiment with reference to the accompanying drawings. The directional terms mentioned in the following embodiments, such as up, down, left, right, front or back, etc., are only the directions with reference to the accompanying drawings. Therefore, the directional terms used are used to illustrate and not to limit the present invention.

[0047] Reference Figure 1 , which depicts a schematic diagram of an optical film according to a first embodiment of the present invention. The optical film 100 includes a base layer BL and a microstructure layer ML. The microstructure layer ML is disposed on the surface of the base layer BL, and the microstructure layer ML includes a plurality of microstructures MS, wherein each microstructure MS includes a first surface S1 and a second surface S2 that are disposed opposite to each other. In the present embodiment, each microstructure MS is strip-shaped, and the plurality of microstructures MS are arranged in sequence along a direction D1 from one side SD1 of the optical film 100 toward the other side SD2, and the strip-shaped structure extends in a direction D2. The height of the microstructure layer ML in a direction D3 falls within a range of 5 microns to 100 microns, wherein the direction D3 is parallel to the normal direction of the base layer BL, and is perpendicular to the direction D1 and the direction D2.

[0048] Reference Figure 2 , which depicts a schematic diagram of an optical film according to a second embodiment of the present invention. The optical film 200 includes a base layer BL and a microstructure layer ML. The microstructure layer ML is disposed on the surface of the base layer BL, and the microstructure layer ML includes a plurality of microstructures MS, wherein each microstructure MS includes a first surface S1 and a second surface S2 that are oppositely disposed. In the present embodiment, each microstructure MS is island-shaped, and the plurality of microstructures MS are arranged along a direction D1 from one side SD1 of the optical film 100 toward the other side SD2, or along a direction D2, wherein the direction D1 is not parallel to the direction D2. In some embodiments, the direction D1 is perpendicular to the direction D2, but the present invention is not limited thereto. The height of the microstructure layer ML in the direction D3 falls within a range of 5 microns to 100 microns, wherein the direction D3 is parallel to the normal direction of the base layer BL, and is perpendicular to the direction D1 and the direction D2.

[0049] Please refer to the following Figure 3A as well as Figure 3B , Figure 3A Draw Figure 1 Schematic diagram of the cross section of the optical film, Figure 3B yes Figure 3A A schematic cross-sectional view of a microstructure in FIG. Specifically, Figure 3A Although Figure 1 The cross section of the optical film 100 along the direction D1 is schematically illustrated, but is not limited thereto, and can also be regarded as Figure 2 A schematic cross-sectional view of the optical film 200 along direction D1.

[0050] exist Figure 3A In the embodiment, the base layer BL includes a microstructure connection layer MC and a transparent substrate layer SB1. The microstructure connection layer MC and the plurality of microstructures MS are integrally formed and made of the same material, for example, both include light-curing resin (UV glue). Figure 3A In some embodiments, the base layer BL includes only one of the microstructure connection layer MC and the transparent substrate layer SB1. In other embodiments not shown, the optical film 100 further includes another transparent substrate layer disposed on the other side of the microstructure connection layer MC relative to the transparent substrate layer SB1.

[0051] like Figure 3A as well as Figure 3B As shown, the microstructure MS includes a first surface S1 and a second surface S2. The first surface S1 and the virtual reference plane DS are sandwiched by a first angle θ1, and the second surface S2 and the reference plane DS are sandwiched by a second angle θ2, and the reference plane DS is parallel to the surface of the base layer BL. The vertical height H of the microstructure MS on the base layer BL falls within the range of 5 microns to 100 microns, and the width W of the top surface away from the base layer BL in the direction D1 falls within the range of 10 microns to 200 microns. In the embodiment of the present invention, the angle of the first angle θ1 and the angle of the second angle θ2 are greater than or equal to 40 degrees, and less than or equal to 90 degrees.

[0052] exist Figure 3A In the embodiment, each microstructure MS is arranged at equal intervals along the direction D1, that is, any two adjacent microstructures are arranged at intervals, but the present invention is not limited to this. Figure 3C , which is a schematic cross-sectional view of an optical film according to a third embodiment of the present invention. The distribution density of the plurality of microstructures MS of the optical film 300 increases from one side SD1 of the optical film 300 along the direction D1 toward the other side SD2 opposite to the side SD1, that is, the spacing between any two adjacent microstructures MS gradually decreases along the direction D1, that is, the microstructures MS are not arranged at equal intervals.

[0053] Reference Figure 4 , which depicts a cross-sectional schematic diagram of a display device according to an embodiment of the present invention. The display device 10 includes a display module 120 and an illumination module 110. The display module 120 may be a display panel or a display, and specifically may be, for example, a reflective or semi-transmissive liquid crystal panel, an electronic paper display, etc., and the display module 120 has a display surface 120D for displaying an image. The illumination module 110 is disposed on the display surface 120D of the display module 120, and includes a light source 101, a light guide plate 102, and an optical film 400. The optical film 400 may be implemented by the aforementioned optical film 100 or the optical film 200.

[0054] The optical film 400 is disposed between the display module 120 and the light guide plate 102, and the optical film 400 of this embodiment further includes another transparent substrate layer SB2 disposed on the other side of the microstructure connection layer MC relative to the transparent substrate layer SB1, wherein the light guide plate 102, the optical film 400 and the display module 120 can be laminated and combined in a whole-surface bonding manner by means of adhesive layers OCA1 and OCA2, wherein the adhesive layer OCA1 is located between the light guide plate 102 and the optical film 400, and the adhesive layer OCA1 covers the entire surface of one side of the light guide plate 102 facing the optical film 400 and the entire surface of the transparent substrate layer SB2 of the optical film 400. The adhesive layer OCA2 is located between the display module 120 and the optical film 400.

[0055] like Figure 4 As shown, the light source 101 is disposed on one side SD3 of the light guide plate 102, and emits light IL toward a side SD4 opposite to the side SD3, and the light guide plate 102 is used to guide the light IL. The side SD3 of the light guide plate 102 corresponds to the side SD1 of the optical film 400, and the side SD4 of the light guide plate 102 corresponds to the side SD2 of the optical film 400. The light source 101 generates light IL. Since the refractive index of the microstructure MS is different from the refractive index of the air gap between adjacent microstructures MS, at least a portion of the light IL will be reflected by the first surface S1 of each microstructure MS and reach the display surface 120D of the display module 120. Then, the light reflected by the display surface 120D can be reflected by the second surface S2 of each microstructure MS and enter the user's eyes, or directly enter the user's eyes without being reflected by the second surface S2, so that the image on the display surface 120D is visible.

[0056] It should be particularly noted that, compared to some comparative examples of the known technology in which patterns are arranged on the lower surface of the light guide plate 102 to reflect the light IL, the embodiment of the present invention arranges multiple microstructures MS in the optical film 400, so that the adhesive layer OCA1 located between the light guide plate 102 and the optical film 400 can combine the light guide plate 102 and the optical film 400 in a whole-surface bonding manner without the problem of adhesive contacting the light guide plate pattern and causing the pattern's ability to reflect / scatter light to decrease, so that the display device 10 can have higher reliability.

[0057] In some embodiments, the optical film 400 does not include the transparent substrate layer SB1, and the microstructure connection layer MC of the optical film 400 is directly adhered to the display module 120 via the adhesive layer OCA2. In some embodiments, the optical film 400 does not include the microstructure connection layer MC, a plurality of microstructures MS are directly arranged on the transparent substrate layer SB1, and the transparent substrate layer SB1 is adhered to the display module 120 via the adhesive layer OCA2.

[0058] Reference Figure 5, which is a schematic cross-sectional view of a display device according to another embodiment of the present invention. The display device 20 includes a display module 120 and an illumination module 210. The display module 120 has a display surface 120D. The illumination module 210 is disposed on the display surface 120D of the display module 120, and includes a light source 101, a light guide plate 102, and an optical film 500.

[0059] like Figure 5 As shown, the light source 101 is disposed on one side SD3 of the light guide plate 102 and emits light IL toward a side SD4 opposite to the side SD3, wherein the side SD3 of the light guide plate 102 corresponds to the side SD1 of the optical film 500, and the side SD4 of the light guide plate 102 corresponds to the side SD2 of the optical film 500. Figure 4 In the display device 10, the distribution density of the multiple microstructures MS of the optical film 500 in the display device 20 increases from the side SD1 of the optical film 500 along the direction D1 toward the side SD2, so that some areas on the multiple areas on the display surface 120D that are farther away from the light source 101 can correspond to the multiple microstructures MS with higher distribution density, so as to guide the light IL generated by the light source 101 by means of those microstructures MS with higher distribution density, so that some areas that are farther away from the light source 101 can emit more light IL from the light guide plate 102 to enhance the light output brightness of those areas, thereby improving the brightness uniformity of the display device 20.

[0060] Reference Figure 6 , Figure 7 as well as Figure 8 , which respectively illustrate the relative brightness of the display device in the above embodiments when the refractive index of its microstructure layer ML is 1.55, 1.58 and 1.61 respectively, wherein the relative brightness refers to the relative brightness of the display device at a normal viewing angle.

[0061] It can be seen that in the microstructure layer ML with different refractive indices, when the angle of the first angle θ1 between the first surface S1 and the reference surface DS is substantially equal to the angle of the second angle θ2 between the second surface S2 and the reference surface DS, the display device can have good luminance performance. In some embodiments, when the angle of the first angle θ1 and the second angle θ2 is greater than or equal to 55 degrees and less than or equal to 65 degrees, the display device can have better luminance performance. In some embodiments, when the angle of the first angle θ1 and the second angle θ2 is greater than or equal to 57 degrees and less than or equal to 63 degrees, the display device can have better luminance performance.

[0062] Reference Fig. 9 , which depicts a schematic cross-sectional view of a microstructure according to some embodiments of the present invention.

[0063] exist Fig. 9In part (A), according to one embodiment of the present invention, the first surface S1 of the microstructure MS1 and the reference plane DS include a first angle θ1, and the second surface S2 of the microstructure MS1 and the reference plane DS include a second angle θ2, wherein the angle of the first angle θ1 is 90 degrees, and the angle of the second angle θ2 is 90 degrees. The microstructure MS1 also includes a third surface S3, a fourth surface S4, and a fifth surface S5. The third surface S3 is located between the first surface S1 and the fifth surface S5, and the two ends of the third surface S3 are respectively connected to the first surface S1 and the fifth surface S5, wherein the angle θ3 between the third surface S3 and the reference plane DS is greater than or equal to 40 degrees, and less than or equal to 90 degrees. The fourth surface S4 is located between the second surface S2 and the fifth surface S5, and the two ends of the fourth surface S4 are respectively connected to the second surface S2 and the fifth surface S5, wherein the angle θ4 between the fourth surface S4 and the reference plane DS is greater than or equal to 40 degrees, and less than or equal to 90 degrees. In this embodiment, the fifth surface S5 is a plane and parallel to the reference plane DS.

[0064] exist Fig. 9 In part (B), according to one embodiment of the present invention, the first surface S1 of the microstructure MS2 and the reference plane DS include a first angle θ1, and the second surface S2 of the microstructure MS2 and the reference plane DS include a second angle θ2, wherein the angle of the first angle θ1 is 90 degrees, and the angle of the second angle θ2 is 90 degrees. The microstructure MS2 also includes a third surface S3 and a fourth surface S4. The two ends of the third surface S3 are respectively connected to the first surface S1 and the fourth surface S4, and the other end of the fourth surface S4 is connected to the second surface S2, wherein the angle θ3 between the third surface S3 and the reference plane DS is greater than or equal to 40 degrees and less than or equal to 90 degrees. In this embodiment, the fourth surface S4 is a plane and parallel to the reference plane DS.

[0065] exist Fig. 9 In part (C), according to an embodiment of the present invention, the first surface S1 of the microstructure MS3 and the reference surface DS form a first angle θ1, and the second surface S2 of the microstructure MS2 and the reference surface DS form a second angle θ2, wherein the first angle θ1 is 90 degrees, and the second angle θ2 is 90 degrees. The microstructure MS2 further includes a third surface S3. The third surface S3 is a curved surface connected between the first surface S1 and the second surface S2.

[0066] In summary, the optical film provided by the embodiment of the present invention has a microstructure, each microstructure has a first surface and a second surface, the first surface and the reference plane are at a first angle, and the second surface and the reference plane are at a second angle. When the display surface of the display module of the display device is parallel to the reference plane, and the lighting module of the display device is configured with a light source on the side of the light guide plate, at least a portion of the light emitted by the light source will first be reflected by the first surface and / or the second surface and reach the display surface of the display module, and then reflected by the display surface into the user's eyes, so that the image on the display surface of the display device is visible. Compared with the known technology of configuring a pattern on the lower surface of the light guide plate of the lighting module to reflect light, the embodiment of the present invention configures the microstructure in the optical film, and the light guide plate, the optical film and the display module can be stacked and combined in a whole-surface bonding manner, so that the display device can have a higher structural reliability even under the condition of front light illumination.

[0067] However, the above is only a preferred embodiment of the present invention, and it cannot be used to limit the scope of the implementation of the present invention. That is, all simple equivalent changes and modifications made according to the claims and the content of the invention of the present invention are still within the scope of the patent of the present invention. In addition, any embodiment or claim of the present invention does not need to achieve all the purposes, advantages or features disclosed by the present invention. In addition, the abstract and title (invention name) are only used to assist in the retrieval of patent documents, and are not used to limit the scope of rights of the present invention. In addition, the terms "first", "second", etc. mentioned in this specification or claims are only used to name the name of the element or distinguish different embodiments or scopes, and are not used to limit the upper or lower limit on the number of elements.

Claims

1. An optical film, characterized in that: The optical film comprises a base layer and a microstructure layer, wherein: The microstructure layer is disposed on the surface of the base layer, and the microstructure layer includes a plurality of microstructures, wherein each of the plurality of microstructures includes a first surface and a second surface that are oppositely disposed. The first surface and the reference plane form a first angle, the second surface and the reference plane form a second angle, the reference plane is parallel to the surface of the base layer, and the angle of the first angle and the angle of the second angle are greater than or equal to 40 degrees and less than or equal to 90 degrees.

2. The optical film according to claim 1, characterized in that: The angle of the first angle is equal to the angle of the second angle.

3. The optical film according to claim 1, characterized in that: An angle between the first angle and the second angle is greater than or equal to 55 degrees and less than or equal to 65 degrees.

4. The optical film according to claim 1, characterized in that: An angle between the first angle and the second angle is greater than or equal to 57 degrees and less than or equal to 63 degrees.

5. The optical film according to claim 1, characterized in that: The distribution density of the plurality of microstructures increases gradually from one side of the optical film toward the other side opposite to the one side.

6. The optical film according to claim 1, characterized in that: Any two adjacent microstructures among the plurality of microstructures are arranged at intervals.

7. The optical film according to claim 1, characterized in that: The material of the microstructure layer includes light-curing resin.

8. A display device, characterized in that: The display device comprises a display module and a lighting module, wherein: The display module has a display surface; and The lighting module is disposed on the display surface of the display module and includes a light source, a light guide plate and an optical film, wherein: The light source is disposed on a first side of the light guide plate; and The optical film is disposed between the display module and the light guide plate, and the optical film includes a base layer and a microstructure layer, wherein: The microstructure layer is disposed between the surface of the base layer and the light guide plate, and includes a plurality of microstructures, wherein each of the plurality of microstructures includes a first surface and a second surface that are oppositely disposed. The first surface and the reference plane form a first angle, the second surface and the reference plane form a second angle, the reference plane is parallel to the surface of the base layer, and the angle of the first angle and the angle of the second angle are greater than or equal to 40 degrees and less than or equal to 90 degrees.

9. The display device according to claim 8, characterized in that: The distribution density of the plurality of microstructures increases from the first side toward the second side, and the second side is opposite to the first side.

10. The display device according to claim 8, characterized in that: The angle of the first angle is equal to the angle of the second angle.

11. The display device according to claim 8, characterized in that The angle of the first angle and the angle of the second angle are greater than or equal to 55 degrees and less than or equal to 65 degrees.

12. The display device according to claim 8, characterized in that The angle of the first angle and the angle of the second angle are greater than or equal to 57 degrees and less than or equal to 63 degrees.

13. The display device according to claim 8, characterized in that The lighting module further includes a first adhesive layer, wherein the first adhesive layer is located between the light guide plate and the optical film, and the first adhesive layer covers the entire surface of a side of the light guide plate facing the optical film.

14. The display device according to claim 13, characterized in that: The display device further includes a second adhesive layer, and the second adhesive layer is located between the display module and the optical film.

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