Display device

Abstract

A display device comprises a light guide plate, a first light source, a second light source, a plurality of first optical microstructures, a plurality of second optical microstructures and a display panel. The first light source is arranged on one side of the first incident surface of the light guide plate. The second light source is arranged on one side of the second incident surface of the light guide plate. Each first optical microstructure is arranged on the first light emitting surface of the light guide plate. Each second optical microstructure is arranged on the second light emitting surface of the light guide plate. A plurality of second light beams emitted by the second light source are reflected by the plurality of second light-receiving surfaces of the plurality of second optical microstructures, pass through the first light-emitting surface and irradiate the display surface of the display panel. And a plurality of first light beams emitted by the first light source are reflected by the plurality of first light-receiving surfaces of the plurality of first optical microstructures, pass through the second light-emitting surface and are emitted from the display device. According to the display device, the appearance of the whole machine is light and thin, and the display quality is good.

Description

[Technical field]

[0001] The invention relates to a display device, and in particular to a display device with an anti-peeping function. [Background technology]

[0002] Reflective display devices have gradually attracted attention due to their low-energy operation mode and high outdoor visibility. For example, their applications in readers and commercial displays (such as advertising billboards, electronic tags, sports watches, etc.) are increasing year by year. In order to maintain the display quality when the ambient light is insufficient, a reflective display device with a front light source has been proposed. On the other hand, in order to meet the anti-peeping requirements of reflective display devices, the current practice is to add an anti-peeping film to the display device. However, if the lighting requirements of the front light source and the anti-peeping requirements of the display screen are to be met at the same time, the thickness of the reflective display device will inevitably increase, and it is also more difficult to take into account both the anti-peeping effect and the lighting effect.

[0003] The "background technology" section is only used to help understand the content of the present invention. Therefore, the content disclosed in the "background technology" section may contain some known technologies that are not known to ordinary technicians in the relevant technical field. The content disclosed in the "background technology" section does not mean that the content or the problems to be solved by one or more embodiments of the present invention have been known or recognized by ordinary technicians in the relevant technical field before the application of the present invention. [Summary of the invention]

[0004] The present invention provides a display device with an anti-peeping function, the whole device has a relatively light and thin appearance and a relatively good display quality.

[0005] Other purposes and advantages of the present invention can be further understood from the technical features disclosed in the present invention.

[0006] To achieve one or part or all of the above purposes or other purposes, one embodiment of the present invention provides a display device. The display device includes a light guide plate, a first light source, a second light source, a plurality of first optical microstructures, a plurality of second optical microstructures and a display panel. The light guide plate has a first light incident surface, a second light incident surface, a first light exit surface and a second light exit surface. The first light incident surface connects the second light incident surface, the first light exit surface and the second light exit surface. The first light exit surface faces away from the second light exit surface. The first light source is arranged on one side of the first light incident surface of the light guide plate, and is suitable for emitting a plurality of first light beams toward the first light incident surface. These first light beams enter the light guide plate via the first light incident surface. The second light source is arranged on one side of the second light incident surface of the light guide plate, and is suitable for emitting a plurality of second light beams toward the second light incident surface. These second light beams enter the light guide plate via the second light incident surface. A plurality of first optical microstructures are arranged on the first light exit surface of the light guide plate, and each has a first light-facing surface facing the first light source. A plurality of second optical microstructures are arranged on the second light exit surface of the light guide plate, and each has a second light-facing surface facing the second light source. The display panel is arranged on one side of the first light emitting surface of the light guide plate and overlaps the first light emitting surface. The plurality of second light beams are reflected by the plurality of second light-facing surfaces of the plurality of second optical microstructures, then pass through the first light emitting surface and illuminate the display surface of the display panel. The plurality of first light beams are reflected by the plurality of first light-facing surfaces of the plurality of first optical microstructures, then pass through the second light emitting surface and emit from the display device.

[0007] Based on the above, in a display device of one embodiment of the present invention, the light guide plate has a first light emitting surface and a second light emitting surface facing back to back with each other. A display panel is provided on one side of the first light emitting surface of the light guide plate. The second optical microstructure disposed on the second light emitting surface is suitable for reflecting the second light beam entering the light guide plate from the second light incident surface, so that it passes through the first light emitting surface and illuminates the display surface of the display panel, so as to serve as an illumination light source when the display device displays. The first optical microstructure disposed on the first light emitting surface is suitable for reflecting the first light beam entering the light guide plate from the first light incident surface, so that it passes through the second light emitting surface and is projected within a specific angle range in the use space, so as to serve as an interference light source when the display device is displayed in an anti-peeping manner. By integrating the optical microstructures with these two functions on the same light guide plate, in addition to greatly reducing the overall thickness of the display device, it is also possible to avoid a reduction in the display efficiency of the display device due to the addition of an additional light guide plate.

[0008] Although the present invention has been disclosed as above by way of embodiments, it is not intended to limit the present invention. Any person skilled in the art may make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the appended claims.

Brief Description of the Drawings

[0009] Figure 1 is a front view schematic diagram of a display device according to a first embodiment of the present invention.

[0010] Figure 2A and Figure 2B yes Figure 1 A side view schematic diagram of a display device.

[0011] Figure 3 is a front view schematic diagram of a display device according to a second embodiment of the present invention.

[0012] Figure 4 is a front view schematic diagram of a display device according to a third embodiment of the present invention.

[0013] Figure 5 yes Figure 4 A schematic cross-sectional view of a display device.

[0014] FIG. 6A to FIG. 6C yes Figure 5 An enlarged schematic diagram of a local area of ​​a display device.

[0015]

Explanation of symbols

[0016] 10, 10A, 10B: Display device

[0017] A1a, A1b, A1c: First angle

[0018] A2a, A2b, A2c: Second angle

[0019] CZ: Central Zone

[0020] DP: Display Panel

[0021] DS: Display surface

[0022] ES1: First light emitting surface

[0023] ES2: Second light emitting surface

[0024] IS1: First light incident surface

[0025] IS2: Second light incident surface

[0026] IS3: Third light incident surface

[0027] IS4: Fourth incident light surface

[0028] LB1: First beam

[0029] LB2: Second beam

[0030] LB3: The third beam

[0031] LB4: Fourth beam

[0032] LGP, LGP-A, LGP-B: Light guide plate

[0033] LRS1, LRS1A: First light-facing side

[0034] LRS2, LRS2A: Second light-facing side

[0035] LRS3, LRS3A: The third light-facing side

[0036] LRS4, LRS4A: Fourth light-facing side

[0037] LS1: First Light Source

[0038] LS2: Second light source

[0039] LS3: The Third Light Source

[0040] LS4: The Fourth Light Source

[0041] MS1, MS1A: The first optical microstructure

[0042] MS1cp: Central section

[0043] MS1p1: Part I

[0044] MS1p2: Part 2

[0045] MS2, MS2A, MS2-1, MS2-2: Second optical microstructure

[0046] OBR1, OBR2: Spectator

[0047] USR: User

[0048] X, Y, Z: direction

[0049] Z1: First Zone

[0050] Z2: The second zone. [Specific implementation method]

[0051] The above and 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 referenced to the directions of the accompanying drawings. Therefore, the directional terms used are used to illustrate and not to limit the present invention.

[0052] Figure 1 is a front view schematic diagram of a display device according to a first embodiment of the present invention. Figure 2A and Figure 2B yes Figure 1 Schematic diagram of a side view of a display device. Figure 1 , Figure 2A and Figure 2B, the display device 10 includes a light guide plate LGP, a first light source LS1, a second light source LS2, a plurality of first optical microstructures MS1, a plurality of second optical microstructures MS2 and a display panel DP. The light guide plate LGP has a first light incident surface IS1, a second light incident surface IS2, a first light emitting surface ES1 and a second light emitting surface ES2. The first light incident surface IS1 connects the second light incident surface IS2, the first light emitting surface ES1 and the second light emitting surface ES2. The first light emitting surface ES1 faces away from the second light emitting surface ES2. In the present embodiment, the first light incident surface IS1 may be selectively perpendicular to the second light incident surface IS2, but is not limited thereto. It should be understood that, Figure 1 , Figure 2A and Figure 2B The arrangement and relative positional relationship between the plurality of first optical microstructures MS1 and the plurality of second optical microstructures MS2 are only for illustration and are not intended to be limiting, and there is not necessarily a direct correspondence between the drawings.

[0053] The first light source LS1 is disposed on one side of the first light incident surface IS1 of the light guide plate LGP, and is adapted to emit a plurality of first light beams LB1 toward the first light incident surface IS1. These first light beams LB1 enter the light guide plate LGP via the first light incident surface IS1. The second light source LS2 is disposed on one side of the second light incident surface IS2 of the light guide plate LGP, and is adapted to emit a plurality of second light beams LB2 toward the second light incident surface IS2. These second light beams LB2 enter the light guide plate LGP via the second light incident surface IS2.

[0054] In this embodiment, the horizontal field of view of the user USR is distributed along direction X, and the vertical field of view is distributed along direction Y. It is particularly noted that the first light incident surface IS1 of the light guide plate LGP is located on one side of the light guide plate LGP along direction X, and the second light incident surface IS2 is located on one side of the light guide plate LGP along direction Y.

[0055] In the present embodiment, the first light emitting surface ES1 of the light guide plate LGP faces the display surface DS of the display panel DP, and overlaps the display surface DS along the normal direction of the display surface DS (e.g., direction Z). That is, the display panel DP is disposed on one side of the first light emitting surface ES1 of the light guide plate LGP, and the second light emitting surface ES2 faces away from the display panel DP. In the present embodiment, the display panel DP is, for example, a reflective display panel or a semi-transmissive and semi-reflective display panel, but is not limited thereto. In other embodiments, the display panel DP generally refers to other types of displays used for display.

[0056] It is particularly noted that a plurality of first optical microstructures MS1 are disposed on the first light emitting surface ES1 of the light guide plate LGP corresponding to the first light source LS1 , and a plurality of second optical microstructures MS2 are disposed on the second light emitting surface ES2 corresponding to the second light source LS2 .

[0057] More specifically, each of the plurality of first optical microstructures MS1 has a first light-facing surface LRS1 facing the first light source LS1, and the plurality of first light beams LB1 transmitted in the light guide plate LGP can be reflected by the plurality of first light-facing surfaces LRS1 of the first optical microstructures MS1 and then pass through the second light-exiting surface ES2 and be emitted from the display device 10. Each of the plurality of second optical microstructures MS2 has a second light-facing surface LRS2 facing the second light source LS2, and the plurality of second light beams LB2 transmitted in the light guide plate LGP can be reflected by the plurality of second light-facing surfaces LRS2 of the second optical microstructures MS2 and then pass through the first light-exiting surface ES1 and be irradiated on the display surface DS of the display panel DP.

[0058] In the present embodiment, the display device 10 mainly uses ambient light as the illumination light source during display, and the ambient light, for example, passes through the light guide plate LGP from one side of the second light emitting surface ES2 of the light guide plate LGP and irradiates the display surface DS of the display panel DP. When the ambient light is sufficient, the second light source LS2 can be turned off. On the contrary, when the ambient light in the use field is insufficient, the second light source LS2 can be turned on as an auxiliary or main illumination light source for the display panel DP, and the second optical microstructure MS2 on the light guide plate LGP is suitable for guiding the second light beam LB2 emitted by the second light source LS2 and transmitted via the light guide plate LGP to the display surface DS of the display panel DP (such as Figure 2A as shown) for lighting.

[0059] On the other hand, the user USR can switch the display device 10 between the sharing mode and the anti-peeping mode by turning on the first light source LS1. For example, when the first light source LS1 is turned on to emit a plurality of first light beams LB1, the plurality of first optical microstructures MS1 on the light guide plate LGP are suitable for guiding the first light beams LB1 transmitted through the light guide plate LGP to a space outside the user USR, such as Figure 2B The location of bystander OBR1 or bystander OBR2 (such as Figure 2B Therefore, both the bystander OBR1 and the bystander OBR2 can see the first light beams LB1 emitted by the first light source LS1.

[0060] For example, the first light source LS1 can be a white light source. For the bystanders OBR1 and OBR2, when the first light source LS1 is turned on, the multiple first light beams LB1 will form a bright white picture overlapping with the display surface DS of the display panel DP. The brightness of this bright white picture can be higher than the display brightness of the image picture of the display panel DP. Therefore, the image picture of the display panel DP cannot be clearly seen by the bystanders after being superimposed on this bright white picture, thereby achieving an anti-peeping effect. Since the multiple first light beams LB1 emitted by the first light source LS1 will not be directed to the user USR, the user USR can still clearly see the image picture of the display panel DP.

[0061] On the contrary, when the user USR wants to operate the display device 10 in the sharing mode, the first light source LS1 can be turned off. At this time, the bystanders OBR1 and OBR2 are no longer disturbed by the bright white image produced by the first light source LS1 and the plurality of first optical microstructures MS1 on the light guide plate LGP, and can clearly see the image of the display panel DP.

[0062] In this embodiment, the cooperation relationship between the first light source LS1 and the plurality of first optical microstructures MS1 on the light guide plate LGP enables the display device 10 to have an anti-peeping function, and the cooperation relationship between the second light source LS2 and the plurality of second optical microstructures MS2 on the light guide plate LGP enables the display device 10 to have a front light illumination function. By integrating two optical microstructures corresponding to different functions on the same light guide plate LGP, the thickness of the entire display device 10 can be greatly reduced. Since the two optical microstructures do not need to be arranged on two light guide plates respectively, it can also prevent the display efficiency of the display device 10 (such as the transmittance of ambient light or auxiliary light) from being reduced due to the addition of an additional light guide plate.

[0063] In order to further enhance the anti-peeping effect, the display device 10 may further selectively include a third light source LS3, which is disposed on one side of the third light incident surface IS3 of the light guide plate LGP. In this embodiment, the third light incident surface IS3 is connected to the second light incident surface IS2 and is opposite to the first light incident surface IS1. More specifically, the first light incident surface IS1 and the third light incident surface IS3 are respectively located on opposite sides of the light guide plate LGP along the direction X.

[0064] The third light source LS3 is suitable for emitting a plurality of third light beams LB3 toward the third light incident surface IS3. These third light beams LB3 enter the light guide plate LGP via the third light incident surface IS3. Each of the plurality of first optical microstructures MS1 on the first light exit surface ES1 of the light guide plate LGP further has a third light facing surface LRS3 facing the third light source LS3, and the plurality of third light beams LB3 transmitted in the light guide plate LGP can be reflected via the plurality of third light facing surfaces LRS3 of these first optical microstructures MS1 and then pass through the second light exit surface ES2 and exit from the display device 10.

[0065] For example, when the third light source LS3 is turned on to emit a plurality of third light beams LB3, the plurality of first optical microstructures MS1 on the light guide plate LGP are suitable for directing the third light beams LB3 transmitted through the light guide plate LGP to a space outside the user USR, such as Figure 2B Therefore, both the bystander OBR1 and the bystander OBR2 can see the third light beams LB3 emitted by the third light source LS3.

[0066] When the first light source LS1 and the third light source LS3 are turned on at the same time, the brightness of the bright white image seen by the bystander facing the display surface DS of the display panel DP can be further enhanced, thereby improving the anti-peeping effect of the display device 10. Since the third light beam LB3 emitted by the third light source LS3 will not be directed to the user USR like the first light beam LB1, the user USR can still clearly see the image of the display panel DP.

[0067] It should be noted that although Figure 2B Although not shown in the figure, it is understandable that the first light beam LB1 can also be directed to the bystander OBR1 after being reflected by the first light-facing surface LRS1 of the first optical microstructure MS1, and the third light beam LB3 can also be directed to the bystander OBR2 after being reflected by the third light-facing surface LRS3 of the first optical microstructure MS1. That is, the side to which the light beam emitted by the first light source LS1 or the third light source LS3 is directed to the user USR after being reflected by the first optical microstructure can be determined by adjusting the light-facing surface design of the first optical microstructure, and the present invention does not limit this. It should be understood that the first light-facing surface LRS1 of each first optical microstructure MS1 is located between the first light-incident surface IS1 and the third light-facing surface LRS3, and the third light-facing surface LRS3 of each first optical microstructure MS1 is located between the third light-incident surface IS3 and the first light-facing surface LRS1, wherein the term "facing the light" is only used to indicate that the structure faces the direction of the light-incident surface and the light source, and is not used to limit its optical effect.

[0068] On the other hand, in order to further enhance the effect of front lighting, the display device 10 may further include a fourth light source LS4, which is disposed on one side of the fourth light incident surface IS4 of the light guide plate LGP. In this embodiment, the fourth light incident surface IS4 connects the first light incident surface IS1 and the third light incident surface IS3, and is opposite to the second light incident surface IS2. More specifically, the second light incident surface IS2 and the fourth light incident surface IS4 are respectively located on opposite sides of the light guide plate LGP along the direction Y.

[0069] The fourth light source LS4 is suitable for emitting a plurality of fourth light beams LB4 toward the fourth light incident surface IS4. These fourth light beams LB4 enter the light guide plate LGP via the fourth light incident surface IS4. Each of the plurality of second optical microstructures MS2 on the second light exit surface ES2 of the light guide plate LGP further comprises a fourth light facing surface LRS4 facing the fourth light source LS4, and the plurality of fourth light beams LB4 transmitted in the light guide plate LGP can be reflected by the plurality of fourth light facing surfaces LRS4 of the second optical microstructures MS2 and then pass through the first light exit surface ES1 and illuminate the display surface DS of the display panel DP (e.g., Figure 2A That is, the fourth light source LS4, like the second light source LS2, can be used as an auxiliary light source or a main light source of the display device 10 when the ambient light is insufficient.

[0070] For example, the user USR can choose to turn on one light source (e.g., the second light source LS2 or the fourth light source LS4) or two light sources (e.g., the second light source LS2 and the fourth light source LS4) according to the ambient light state of the use scene to meet the lighting requirements of the display device 10 during display. It should be understood that the second light-facing surface LRS2 of each second optical microstructure MS2 is located between the second light-incident surface IS2 and the fourth light-facing surface LRS4, and the fourth light-facing surface LRS4 of each second optical microstructure MS2 is located between the fourth light-incident surface IS4 and the second light-facing surface LRS2, wherein the term "facing the light" is only used to indicate that the structure faces the direction of the light-incident surface and the light source, and is not used to limit its optical effect.

[0071] Other embodiments will be listed below to illustrate the present disclosure in detail, wherein the same components will be marked with the same symbols, and the description of the same technical content will be omitted. For the omitted parts, please refer to the aforementioned embodiments, which will not be repeated below.

[0072] Figure 3 is a front view schematic diagram of a display device according to a second embodiment of the present invention. Figure 3 The display device 10A of this embodiment and Figure 1 The difference between the display device 10 is that the configuration of the second optical microstructure is different. For example, in this embodiment, the orthographic projection profile of each of the plurality of second optical microstructures MS2A on the second light emitting surface ES2 of the light guide plate LGP-A on the second light emitting surface ES2 may be a meniscus shape.

[0073] More specifically, the light-facing surface of the second optical microstructure MS2A facing the corresponding light source has an outer contour that bulges toward the light source. For example, in the present embodiment, the plurality of second optical microstructures MS2A can be divided into a plurality of second optical microstructures MS2-1 disposed toward the second light source LS2 and a plurality of second optical microstructures MS2-2 disposed toward the fourth light source LS4. The second light-facing surface LRS2A of the second optical microstructure MS2-1 bulges toward the second light source LS2, while the fourth light-facing surface LRS4A of the second optical microstructure MS2-2 bulges toward the fourth light source LS4.

[0074] The design of the meniscus-shaped light-facing surface can reduce the probability of the second light beam being reflected by the second optical microstructure MS2-2 and the probability of the fourth light beam being reflected by the second optical microstructure MS2-1. In other words, the second optical microstructure MS2A can be prevented from reflecting the light beam emitted by the non-corresponding light source. Figure 3 The disclosed content is not limiting. In other embodiments, the number and arrangement of the second optical microstructures respectively disposed corresponding to the second light source LS2 and the fourth light source LS4 can be adjusted according to actual lighting requirements (eg light emission type).

[0075] Figure 4 is a front view schematic diagram of a display device according to a third embodiment of the present invention. Figure 5 yes Figure 4 A schematic cross-sectional view of a display device. FIG. 6A to FIG. 6C yes Figure 5 Please refer to Figure 4 and Figure 5 The display device 10B of this embodiment is Figure 1 The only difference between the display device 10 is that the configuration of the first optical microstructure is different.

[0076] For example, in this embodiment, the appearance of the plurality of first optical microstructures MS1A on the first light emitting surface ES1 of the light guide plate LGP-B is olive-shaped. Figure 1 More specifically, the first angle between the first light-facing surface LRS1A of the first optical microstructure MS1A and the first light-emitting surface ES1 and the second angle between the third light-facing surface LRS3A and the first light-emitting surface ES1 both gradually change as they move away from the first light-emitting surface ES1.

[0077] like FIG. 6A to FIG. 6C As shown, the first angle (for example, the first angle A1a, the first angle A1b or the first angle A1c) between the first light-facing surface LRS1A of the first optical microstructure MS1A and the first light-emitting surface ES1 will gradually increase as it moves away from the first light-emitting surface ES1. Similarly, the second angle (for example, the second angle A2a, the second angle A2b or the second angle A2c) between the third light-facing surface LRS3A of the first optical microstructure MS1A and the first light-emitting surface ES1 will gradually increase as it moves away from the first light-emitting surface ES1. However, the present invention is not limited to this. In other embodiments not shown in the figure, the first angle and the second angle of the first optical microstructure may also gradually decrease as they move away from the first light-emitting surface ES1. Specifically, in the present embodiment, the first light-facing surface LRS1A is composed of a plurality of inclined surfaces with different slopes, and the third light-facing surface LRS3A is also composed of a plurality of inclined surfaces with different slopes. However, the present invention is not limited thereto, and in other embodiments, the first light-facing surface LRS1A may be a curved surface with different curvatures, and the third light-facing surface LRS3A may also be a curved surface with different curvatures.

[0078] Please continue to refer to Figure 4 and Figure 5In the present embodiment, the first light emitting surface ES1 of the light guide plate LGP-B can distinguish a central area CZ, a first area Z1 and a second area Z2. The first area Z1 is disposed between the central area CZ and the first light incident surface IS1 along the arrangement direction (e.g., direction X) of the first light incident surface IS1 and the third light incident surface IS3. The second area Z2 is disposed between the central area CZ and the third light incident surface IS3 along the arrangement direction. That is, the first area Z1 and the second area Z2 are respectively disposed on opposite sides of the central area CZ along the direction X. In the present embodiment, the plurality of first optical microstructures MS1A include a central portion MS1cp, a first portion MS1p1 and a second portion MS1p2 respectively located in the central area CZ, the first area Z1 and the second area Z2.

[0079] Please also refer to FIG. 6A to FIG. 6C , the minimum difference between the first angle A1c and the second angle A2c of each of the central portions MS1cp of these first optical microstructures MS1A is smaller than the minimum difference between the first angle A1a and the second angle A2a of each of the first portions MS1p1 and the minimum difference between the first angle A1b and the second angle A2b of each of the second portions MS1p2. In other words, compared with the cross-sectional profiles of the first light-facing surface LRS1A and the third light-facing surface LRS3A of each of the central portions MS1cp located in the central zone CZ, the cross-sectional profiles of the first light-facing surface LRS1A and the third light-facing surface LRS3A of each of the first portions MS1p1 located in the first zone Z1 and the cross-sectional profiles of the first light-facing surface LRS1A and the third light-facing surface LRS3A of each of the second portions MS1p2 located in the second zone Z2 are more asymmetric.

[0080] For example, in this embodiment, the minimum difference between the first angle A1c and the second angle A2c of each of the central portions MS1cp of the plurality of first optical microstructures MS1A is 0. More specifically, the cross-sectional profiles of the first light-facing surface LRS1A and the third light-facing surface LRS3A of each of the central portions MS1cp may be symmetrically distributed (e.g., Figure 6B The maximum value of the first angle A1a of each of the first parts MS1p1 of these first optical microstructures MS1A is smaller than the maximum value of the second angle A2a (as shown in FIG. Fig. 6A The maximum value of the second angle A2b of each of the second portions MS1p2 of the first optical microstructures MS1A is smaller than the maximum value of the first angle A1b (as shown in FIG. Figure 6CIt should be understood that the maximum value of the aforementioned first angle A1a refers to the angle value of the largest angle among the multiple first angles A1a of the single first optical microstructure MS1A, and similarly, the maximum value of the aforementioned second angle A2a refers to the angle value of the largest angle among the multiple second angles A2a of the single first optical microstructure MS1A.

[0081] In other words, the slope of the first light-facing surface LRS1A of each of the first parts MS1p1 changes more gently as it moves away from the first light-emitting surface ES1 than the slope of the third light-facing surface LRS3A changes as it moves away from the first light-emitting surface ES1, and the slope of the third light-facing surface LRS3A of each of the second parts MS1p2 changes more gently as it moves away from the first light-emitting surface ES1 than the slope of the first light-facing surface LRS1A changes as it moves away from the first light-emitting surface ES1.

[0082] From another point of view, the maximum value of the first angle A1a of each of the first parts MS1p1 of the plurality of first optical microstructures MS1A is smaller than the maximum value of the first angle A1b of each of the second parts MS1p2, and the maximum value of the second angle A2b of each of the second parts MS1p2 is smaller than the maximum value of the second angle A2a of each of the first parts MS1p1.

[0083] It is particularly noted that, in the present embodiment, the maximum value of the first angle A1a of each of the first portions MS1p1 in the first region Z1 gradually increases as the setting position moves away from the first light incident surface IS1, and the maximum value of the second angle A2b of each of the second portions MS1p2 in the second region Z2 gradually increases as the setting position moves away from the third light incident surface IS3. In other words, the minimum difference between the first angle A1a and the second angle A2a of each of the first portions MS1p1 gradually decreases as the setting position approaches the central region CZ, and the minimum difference between the first angle A1b and the second angle A2b of each of the second portions MS1p2 gradually decreases as the setting position approaches the central region CZ.

[0084] Through the gradual distribution of the first angle (i.e. the angle between the first light-facing surface LRS1A and the first light-emitting surface ES1) and the second angle (i.e. the angle between the third light-facing surface LRS3A and the first light-emitting surface ES1) of the first optical microstructure MS1A in the direction X, the light collection property of the light beams emitted by the first light source LS1 and the third light source LS3 in the space of the bystanders OBR1 and OBR2 can be further increased, which helps to improve the anti-peeping effect of the display device 10B for bystanders when operating in the anti-peeping mode and improve the display quality for the user USR, and further avoids the slight decrease in screen brightness and interference on the left and right sides of the picture due to the first optical microstructure with a fixed first angle and a second angle.

[0085] In summary, in a display device of one embodiment of the present invention, a light guide plate has a first light emitting surface and a second light emitting surface facing back to back with each other. A display panel is provided on one side of the first light emitting surface of the light guide plate. The second optical microstructure disposed on the second light emitting surface is suitable for reflecting the second light beam entering the light guide plate from the second light incident surface, so that it passes through the first light emitting surface and illuminates the display surface of the display panel, so as to serve as an illumination light source when the display device displays. The first optical microstructure disposed on the first light emitting surface is suitable for reflecting the first light beam entering the light guide plate from the first light incident surface, so that it passes through the second light emitting surface and is projected within a specific angle range in the use space, so as to serve as an interference light source when the display device is anti-peeping display. By integrating these two functional optical microstructures on the same light guide plate, at least one of the following advantages is achieved: in addition to significantly reducing the overall thickness of the display device, it can also prevent the display efficiency of the display device from being reduced due to the addition of an additional light guide plate.

[0086] The above contents are only preferred embodiments of the present invention, and should not be used to limit the scope of the present invention. That is, any simple equivalent changes and modifications made according to the claims and the description of the present invention are still within the scope of the present invention. In addition, any embodiment or claim of the present invention does not have to achieve all the purposes, advantages or features disclosed in the present invention. In addition, the abstract and the title are only used to assist in searching 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 to distinguish different embodiments or scopes, and are not used to limit the upper or lower limit of the number of elements.

Claims

1. A display device, characterized in that: The display device includes a light guide plate, a first light source, a second light source, a plurality of first optical microstructures and a plurality of second optical microstructures, wherein: The light guide plate has a first light incident surface, a second light incident surface, a first light emitting surface and a second light emitting surface, the first light incident surface connects the second light incident surface, the first light emitting surface and the second light emitting surface, and the first light emitting surface is opposite to the second light emitting surface; The first light source is disposed on one side of the first light incident surface of the light guide plate, and is adapted to emit a plurality of first light beams toward the first light incident surface, and the plurality of first light beams enter the light guide plate via the first light incident surface; The second light source is disposed on one side of the second light incident surface of the light guide plate, and is adapted to emit a plurality of second light beams toward the second light incident surface, and the plurality of second light beams enter the light guide plate via the second light incident surface; The plurality of first optical microstructures are arranged on the first light emitting surface of the light guide plate, and each of the plurality of first optical microstructures has a first light facing surface facing the first light source; The plurality of second optical microstructures are arranged on the second light emitting surface of the light guide plate, and each of the plurality of second optical microstructures has a second light facing surface facing the second light source; The display panel is disposed on one side of the first light emitting surface of the light guide plate and overlaps the first light emitting surface. Among them, the multiple second light beams are reflected by the multiple second light-facing surfaces of the multiple second optical microstructures, then pass through the first light-emitting surface and illuminate the display surface of the display panel, and the multiple first light beams are reflected by the multiple first light-facing surfaces of the multiple first optical microstructures, then pass through the second light-emitting surface and emerge from the display device.

2. The display device according to claim 1, characterized in that The first light incident surface is perpendicular to the second light incident surface.

3. The display device according to claim 1, characterized in that The light guide plate further has a third light incident surface, the third light incident surface is connected to the second light incident surface and is opposite to the first light incident surface, and the display device further includes: a third light source, disposed on one side of the third light incident surface of the light guide plate, and adapted to emit a plurality of third light beams toward the third light incident surface, wherein the plurality of third light beams enter the light guide plate via the third light incident surface, Wherein, each of the plurality of first optical microstructures further comprises a third light-facing surface facing the third light source, and the plurality of third light beams are reflected by the plurality of third light-facing surfaces of the plurality of first optical microstructures and then pass through the second light-emitting surface and emerge from the display device.

4. The display device according to claim 3, characterized in that: A first angle is defined between the first light-facing surface and the first light-emitting surface of each of the first optical microstructures, a second angle is defined between the third light-facing surface and the first light-emitting surface of each of the first optical microstructures, and the first angle and the second angle of each of the first optical microstructures gradually change as they move away from the first light-emitting surface.

5. The display device according to claim 4, characterized in that: The light guide plate also has a central area, a first area and a second area, the first area is arranged between the central area and the first light incident surface along the arrangement direction of the first light incident surface and the third light incident surface, and the second area is arranged between the central area and the third light incident surface along the arrangement direction. The multiple first optical microstructures include a central part, a first part and a second part respectively located in the central area, the first area and the second area, and the minimum difference between the first angle and the second angle of each of the central parts of the multiple first optical microstructures is smaller than the minimum difference between the first angle and the second angle of each of the first parts or the second parts of the multiple first optical microstructures.

6. The display device according to claim 5, characterized in that: The minimum difference between the first angle and the second angle of each of the central portions of the plurality of first optical microstructures is zero.

7. The display device according to claim 4, characterized in that: The light guide plate also has a first area and a second area, the first area is arranged between the second area and the first light incident surface along the arrangement direction of the first light incident surface and the third light incident surface, and the second area is arranged between the first area and the third light incident surface along the arrangement direction. The multiple first optical microstructures include a first part and a second part respectively located in the first area and the second area, the maximum value of the first angle of each of the first parts of the multiple first optical microstructures is smaller than the maximum value of the first angle of each of the second parts of the multiple first optical microstructures, and the maximum value of the second angle of each of the second parts of the multiple first optical microstructures is smaller than the maximum value of the second angle of each of the first parts of the multiple first optical microstructures.

8. The display device according to claim 4, characterized in that: The light guide plate also has a first area and a second area, the first area is arranged between the second area and the first light incident surface along the arrangement direction of the first light incident surface and the third light incident surface, and the second area is arranged between the first area and the third light incident surface along the arrangement direction. The multiple first optical microstructures include a first part and a second part respectively located in the first area and the second area, the maximum value of the first angle of each of the first parts of the multiple first optical microstructures is smaller than the maximum value of the second angle, and the maximum value of the second angle of each of the second parts of the multiple first optical microstructures is smaller than the maximum value of the first angle.

9. The display device according to claim 1, characterized in that: The orthographic projection profile of each of the plurality of second optical microstructures on the second light-emitting surface is a crescent shape.

10. The display device according to claim 1, characterized in that The light guide plate further has a fourth light incident surface, the fourth light incident surface is connected to the first light incident surface and is opposite to the second light incident surface, and the display device further includes: a fourth light source, disposed on one side of the fourth light incident surface of the light guide plate, and adapted to emit a plurality of fourth light beams toward the fourth light incident surface, wherein the plurality of fourth light beams enter the light guide plate via the fourth light incident surface, Wherein, each of the plurality of second optical microstructures further has a fourth light-facing surface facing the fourth light source, and the plurality of fourth light beams are reflected by the plurality of fourth light-facing surfaces of the plurality of second optical microstructures and then pass through the first light-emitting surface to illuminate the display surface of the display panel.

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