Dimming unit and display device thereof

Abstract

The invention provides a dimming unit which comprises a collimation optical layer and an optical film, the optical film is provided with a light-emitting surface and a light-in surface opposite to the light-emitting surface, and the collimation optical layer is arranged opposite to the light-in surface of the optical film. A plurality of microstructures are formed on the light-emitting surface, each microstructure has a height h in the normal direction of the light-emitting surface and has a virtual aperture # imgabs0 # in the x coordinate axis direction parallel to the light-emitting surface, and the ratio # imgabs2 # of the height h to the virtual aperture # imgabs1 # is 0.2-1. The dimming unit has the effect of adjusting the peep-proof angle brightness, and the display brightness of the front view angle can be improved through light pattern control.

Description

Technical Field

[0001] The invention relates to a dimming unit, in particular to a dimming unit for adjusting the brightness of an anti-peeping viewing angle and a display device thereof. Background Art

[0002] With the improvement of privacy awareness, display devices with anti-peeping function are becoming more and more popular. The previous technology adjusts the light emission angle by setting an anti-peeping film, so that the light can be emitted in a smaller viewing angle range, providing users with image visibility at a normal viewing angle and limiting the visibility at non-normal viewing angles. Figure 1 FIG. 1 is a graph showing the viewing angle and brightness of a display device according to a comparative example of the prior art. Figure 1 As shown, when a user views an image at a normal viewing angle, the display brightness often decreases significantly as the viewing angle increases, which may easily cause viewing discomfort to the user. Therefore, relevant industry players are eager to solve the viewing comfort problem of anti-peeping display devices. Summary of the invention

[0003] The present invention provides a dimming unit, which can improve the situation that when a user watches an image at a normal viewing angle, the display brightness will obviously decrease as the viewing angle increases, thereby improving the viewing comfort.

[0004] The dimming unit provided by the present invention includes an optical film and a collimating optical layer. The optical film has a light emitting surface and a light incident surface opposite to the light emitting surface. A plurality of microstructures are formed on the light emitting surface, and each microstructure has a plurality of boundaries. The boundary of each microstructure is connected to the boundary of an adjacent microstructure, and the boundary of each microstructure is a polygon in the orthographic projection on the light emitting surface. Each microstructure has a height h in the normal direction of the light emitting surface, and each microstructure also has a virtual aperture in the x-axis direction parallel to the light emitting surface. And the height h is equal to the virtual aperture Ratio The collimating optical layer is arranged opposite to the light incident surface of the optical film.

[0005] In one embodiment of the present invention, the height h and the virtual aperture Ratio It is 0.3~0.7.

[0006] In one embodiment of the present invention, each of the above-mentioned microstructures has a surface profile, and the function of the surface profile is as follows:

[0007]

[0008] Wherein, s(x) represents the surface profile of each microstructure on the x-axis, the x value represents the vertical projection position of the surface profile on the x-axis, the R value represents the curvature radius of the vertex of each microstructure, and the k value represents the cone coefficient of each microstructure. Each microstructure has the same R value and k value.

[0009] In one embodiment of the present invention, the ratio of the cone coefficient to the curvature radius (k / R) satisfies the following condition: -187.5 1 / μm≤k / R≤-20 1 / μm.

[0010] In one embodiment of the present invention, each of the above-mentioned microstructures is suitable for forming a light pattern, and the light pattern has a viewing angle, and the function of the viewing angle is as follows:

[0011] FOV=A(k / R)+B

[0012] Wherein, FOV represents the field of view of the light type, and the A value and the B value satisfy the following conditions: -0.1≤A≤-1, and B is a constant greater than 0.

[0013] In one embodiment of the present invention, the cone coefficient k satisfies the following condition: -1.5≤k≤-0.8.

[0014] In one embodiment of the present invention, the curvature radius R satisfies the following condition: 0.008 μm≤R≤0.04 μm.

[0015] In one embodiment of the present invention, the virtual aperture of each microstructure is The following conditions are met:

[0016]

[0017] In one embodiment of the present invention, the virtual aperture of each microstructure is It is the difference between two adjacent x values ​​when s(x) of the surface profile function is 0 and satisfies the following conditions:

[0018] In one embodiment of the present invention, the height h of each of the above-mentioned microstructures satisfies the following condition: 10 μm≤h≤50 μm.

[0019] In one embodiment of the present invention, the height h of each of the microstructures is the maximum value of s(x) of the function of the surface profile and satisfies the following condition: 10 μm≤h≤50 μm.

[0020] In one embodiment of the present invention, the microstructure is protruding or recessed from the light emitting surface.

[0021] In one embodiment of the present invention, the material of the optical film may be polycarbonate, polyethylene terephthalate, polypropylene, polyvinyl chloride, polydimethylsiloxane or a combination thereof.

[0022] In one embodiment of the present invention, the collimating optical layer is a privacy film or a lens.

[0023] The present invention also provides a display device, comprising the above-mentioned dimming unit, a display panel and a first light-emitting unit. The display panel is arranged opposite to the light-emitting surface of the optical film, the first light-emitting unit is arranged opposite to the collimating optical layer of the dimming unit, and the dimming unit is located between the display panel and the first light-emitting unit. The first light-emitting unit emits an initial light beam to the collimating optical layer, and the initial light beam forms a collimated light beam after passing through the collimating optical layer. After the collimated light beam enters the optical film through the light incident surface, it is emitted from the microstructure of the light-emitting surface and forms a divergent light beam, and the divergent light beam has a divergence angle θ relative to the normal of the light incident surface.

[0024] In one embodiment of the present invention, the first light emitting unit comprises a first light guide plate and a first light source, wherein the first light guide plate has a side surface, and the first light source is disposed on the side surface of the first light guide plate.

[0025] In one embodiment of the present invention, the first light emitting unit comprises a first light guide plate and a first light source, wherein the first light guide plate has an upper surface adjacent to the collimating optical layer, and the first light source is disposed on the upper surface of the first light guide plate.

[0026] In one embodiment of the present invention, the above-mentioned display device further includes a second light-emitting unit, which is disposed between the display panel and the optical film, and the second light-emitting unit includes a second light guide plate and a second light source disposed on the side surface of the second light guide plate, wherein the above-mentioned display device can be switched between multiple modes, including: an anti-peeping mode, when the first light-emitting unit is turned on and the second light-emitting unit is turned off, the divergent light beam passes through the second light-emitting unit and the display panel to form a first light-emitting light beam, and the first light-emitting light beam has a first maximum light-emitting angle relative to the normal line on the plane of the display panel away from the light-emitting surface of the optical film. A sharing mode, when the first light-emitting unit is turned on and the second light-emitting unit is turned on, at least one light beam emitted by the second light-emitting unit passes through the second light-emitting unit and the display panel to form a second light-emitting light beam, and the second light-emitting light beam has a second maximum light-emitting angle relative to the normal line on the plane of the display panel away from the light-emitting surface of the optical film, and the first maximum light-emitting angle is smaller than the second maximum light-emitting angle.

[0027] In one embodiment of the present invention, when θ=0 degree, the divergent light beam has a first brightness, and when 0 degree<θ≦20 degree or -20 degree≦θ<0 degree, the divergent light beam has a second brightness, wherein the second brightness is 90% to 105% of the first brightness.

[0028] Since the present invention adopts a collimating optical layer and an optical film with a microstructure on the light emitting surface, the display brightness at a normal viewing angle can be improved by controlling the light pattern, and the display brightness at a normal viewing angle can be improved while achieving a display anti-peeping effect.

[0029] In order to make the above and other purposes, features and advantages of the present invention more clearly understood, embodiments are given below with reference to the accompanying drawings for detailed description as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 FIG. 4 is a graph showing the viewing angle and brightness of a display device according to a comparative example of the prior art.

[0031] Figure 2 FIG. 1 is a perspective schematic diagram of a display device according to a first embodiment of the present invention.

[0032] Figure 3 FIG. 1 is a schematic cross-sectional view of a display device according to a first embodiment of the present invention along an XZ plane.

[0033] Figure 4 FIG. 4 is a top view schematically showing an optical film according to a first embodiment of the present invention.

[0034] Figure 5 FIG. 4 is a schematic cross-sectional view of the optical film along the AA′ section according to the first embodiment of the present invention.

[0035] Figure 6 FIG. 4 is a schematic three-dimensional diagram of a display device according to a second embodiment of the present invention.

[0036] Figure 7 FIG. 4 is a schematic cross-sectional view of a display device along an XZ plane according to a second embodiment of the present invention.

[0037] Figure 8 FIG. 4 is a schematic three-dimensional diagram of a display device according to a third embodiment of the present invention.

[0038] Fig. 9 FIG. 4 is a schematic cross-sectional view of a display device according to a third embodiment of the present invention along an XZ plane.

[0039] Fig.10 FIG. 4 is a graph showing the viewing angle and brightness of the display device according to the first embodiment of the present invention.

[0040] Wherein, the reference numerals are:

[0041] 10A, 10B, 10C: Display device

[0042] 1: Display panel

[0043] AD: dimming unit

[0044] 2: Optical film

[0045] 21: Light emitting surface

[0046] 211: Microstructure

[0047] 212: Boundary

[0048] 22: Light incident surface

[0049] 3: Collimating optical layer

[0050] 4: The first light-emitting unit

[0051] 41: First light guide plate

[0052] 411, 511: side surface

[0053] 412: Upper surface

[0054] 42: The First Light Source

[0055] 5: Second light-emitting unit

[0056] 51: Second light guide plate

[0057] 52: Second light source

[0058] 6: Optical stacking

[0059] Virtual Aperture

[0060] h: height

[0061] P: Vertex

[0062] R: Radius of curvature

[0063] I1, I2, I3: initial beam

[0064] C1, C2, C3: Collimated beam

[0065] L1, L2, L3: Divergent beams

[0066] L4: First light beam

[0067] L5: Second light beam

[0068] FOV: Field of View

[0069] θ2, θ3: divergence angle

[0070] θ4: The first maximum light emission angle

[0071] θ5: The second largest light output angle

[0072] C: Normal

[0073] x, y, z: direction DETAILED DESCRIPTION

[0074] The other technical contents, features and effects of the present invention mentioned above will be clearly presented in the detailed description of the preferred embodiment in conjunction with one of the reference figures below. 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 attached drawings. Therefore, the directional terms used are used to illustrate and not to limit the present invention. In addition, the terms "first", "second", etc. mentioned in this specification or the scope of the patent application 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.

[0075] like Figure 2 and 3 As shown, the display device 10A of the first embodiment of the present invention includes a display panel 1, a dimming unit AD, an optical stack 6 and a first light-emitting unit 4. The dimming unit AD is disposed between the display panel 1 and the first light-emitting unit 4, and the optical stack 6 is disposed between the dimming unit AD and the first light-emitting unit 4. The following are respectively described:

[0076] The display device 10A may be a notebook computer, a tablet computer, a mobile phone or a display mounted on other electronic devices, but is not limited thereto. The display panel 1 may be, for example, a liquid crystal display panel or other suitable light-transmitting or non-self-luminous display panels, but is not limited thereto.

[0077] The dimming unit AD includes an optical film 2 and a collimating optical layer 3. The optical film 2 has a light emitting surface 21 and a light incident surface 22 opposite to the light emitting surface 21. The collimating optical layer 3 is arranged opposite to the light incident surface 22 of the optical film 2. Specifically, the display panel 1 is arranged opposite to the light emitting surface 21 of the optical film 2, and the first light-emitting unit 4 is arranged on the side of the collimating optical layer 3 away from the optical film 2.

[0078] The detailed structure of the optical film 2 is described in detail below: Figures 2 to 5As shown, the optical film 2 has a light emitting surface 21 and a light incident surface 22 opposite to the light emitting surface 21. The optical film 2 has a plurality of microstructures 211 arranged and formed on the light emitting surface 21, so as to change the traveling direction of the collimated light beam emitted from the collimating optical layer 3, thereby forming a divergent light beam with a specific angle to leave the optical film 2. Each microstructure 211 has a plurality of boundaries 212, and the orthographic projection on the light emitting surface 21 can present a polygon, and any two microstructures can be the same or different shapes, and the boundaries 212 of each microstructure 211 are connected to the boundaries 212 of adjacent microstructures 211, and there will be no blank area between adjacent microstructures 211. The optical film 2 is, for example, a microlens array optical film, but is not limited thereto. The material of the optical film 2 can be plastic, such as but not limited to polycarbonate (PC), polyethylene terephthalate (PET), polypropylene (PP), polyvinyl chloride (PVC), polydimethylsiloxane (PDMS). The optical film 2 can be manufactured by, for example, ultra-precision machining (Ultra-Precision Machining Technology), laser direct writing (Laser Writer / Laser Pattern) or other suitable methods, but is not limited thereto.

[0079] like Figure 4 and 5 As shown, each microstructure 211 of the optical film 2 has a surface profile, and the function of the surface profile is as follows:

[0080]

[0081] Wherein, s(x) represents the surface profile of each microstructure 211 on the x-axis, the x value represents the vertical projection position of the surface profile on the x-axis, the R value represents the curvature radius of the vertex P of each microstructure 211, and the k value represents the cone coefficient of each microstructure 211. The curvature radius R satisfies the following conditions: 0.008 μm ≤ R ≤ 0.04 μm, such as but not limited to 0.01 μm, 0.015 μm, 0.02 μm, 0.025 μm, 0.03 μm and 0.035 μm. The cone coefficient k satisfies the following conditions: -1.5 ≤ k ≤ -0.8, such as but not limited to -1.4, -1.3, -1.2, -1.1, -1.0 and -0.9. The ratio of the cone coefficient k to the curvature radius R (k / R) satisfies the following condition: -187.5 1 / μm≤k / R≤-20 1 / μm, for example but not limited to -180 1 / μm, -160 1 / μm, -140 1 / μm, -120 1 / μm, -100 1 / μm, -80 1 / μm, -60 1 / μm and -40 1 / μm. The virtual aperture of each microstructure 211 For example, it can be the difference between two adjacent x values ​​when the surface profile function s(x) is 0. The surface profile function of each microstructure 211 of the optical film 2 is only an example and is not limited to the above function. Users can adjust the function as needed.

[0082] In addition, the light emitting surface 21 of each microstructure 211 has a height h above the highest point (vertex P) in the normal direction of the light emitting surface 21, that is, the microstructure 211 protrudes from the light emitting surface 21, wherein the height h satisfies the following conditions: 10μm≤h≤50μm, for example but not limited to 15μm, 20μm, 25μm, 30μm, 35μm, 40μm and 45μm. In another embodiment, each microstructure 211 has a lowest point lower than the light emitting surface 21, that is, the microstructure 211 is recessed into the light emitting surface 21 (not shown). Each microstructure 211 has a virtual aperture in the x-axis direction parallel to the light emitting surface 21 Virtual Aperture For example, with a maximum virtual aperture and minimum virtual aperture Maximum virtual aperture and the minimum virtual aperture For example, they are respectively the maximum value and the minimum value of the microstructure 211 in the x-axis direction parallel to the light-emitting surface 21, but are not limited thereto. The following conditions are met: 10 μm ≤ φ ≤ 250 μm, for example but not limited to 30 μm, 50 μm, 80 μm, 100 μm, 130 μm, 150 μm, 180 μm, 200 μm and 230 μm. Ratio is 0.2-1, for example but not limited to 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 and 0.9. In other embodiments, the height h is related to the virtual aperture Ratio It may be 0.3 to 0.7, for example but not limited to 0.35, 0.4, 0.45, 0.5, 0.55, 0.6 and 0.65.

[0083] The collimating optical layer 3 is disposed opposite to the light incident surface 22 of the optical film 2. The collimating optical layer 3 is, for example, a privacy film or a lens, wherein the privacy film may be, for example, a privacy film with a grating structure, and the lens may be, for example, a convex lens or a concave lens, but is not limited thereto. The collimating optical layer 3, for example, achieves the effect of collimating the light beam and preventing privacy by limiting the direction of light beam travel or emitting light at a specific angle through structural design.

[0084] The first light emitting unit 4 includes a first light guide plate 41 and a plurality of first light sources 42, wherein the first light guide plate 41 has a plurality of side surfaces 411 and an upper surface 412 adjacent to the collimating optical layer 3, and the plurality of first light sources 42 are disposed on at least one of the side surfaces 411. In the present embodiment, the plurality of first light sources 42 are disposed on one of the plurality of side surfaces 411 of the first light guide plate 41, but this is not limited thereto. In other embodiments, the plurality of first light sources 42 may also be disposed on the plurality of side surfaces 411 of the first light guide plate 41 at the same time. In addition, in the present embodiment, the first light emitting unit 4 is an edge-type light emitting unit, but this is not limited thereto. In other embodiments, the first light emitting unit 4 may also be a direct-type light emitting unit or a full-array light emitting unit.

[0085] The optical stack 6 may include, for example but not limited to, a diffuser, a diffuser plate and a structural plate, which are suitable for improving the uniformity of the light source. Although the optical stack 6 exists in the display device 10A of this embodiment, it is not limited to this and the optical stack 6 may not be used in other embodiments.

[0086] The following combination Figure 2 and Figure 3 The operation of the display device 10A of this embodiment is described in detail: First, the first light emitting unit 4 is used to emit initial light beams I1, I2, and I3 to the collimating optical layer 3. In detail, when the first light source 42 is turned on, the first light source 42 emits a light beam from the side surface 411 to the first light guide plate 41 and exits from the upper surface 412. Then, the initial light beams I1, I2, and I3 are incident on the collimating optical layer 3 and then exit, and form collimated light beams C1, C2, and C3, thereby limiting the viewing angle of the display device 10A and providing a peek-proof function. Then, the collimated light beams C1, C2, and C3 are incident on the optical film 2 again and pass through the microstructure 211 of the light exit surface 21 to form divergent light beams L1, L2, and L3 and exit at a specific angle, thereby improving the display brightness at the normal viewing angle by controlling the light type. Finally, the divergent light beams L1, L2, and L3 are incident on the display panel 1 and then exit. It should be noted that the number of light beams here is only used for auxiliary explanation and is not limited to this.

[0087] In detail, when the collimated light beams C1, C2, and C3 emitted from the collimating optical layer 3 are incident from the light incident surface 22 of the optical film 2 and pass through the microstructure 211 of the light exiting surface 21 to form divergent light beams L1, L2, and L3, the divergent light beams L1, L2, and L3 have a field of view angle FOV, that is, each microstructure 211 is suitable for forming a light pattern with the field of view angle FOV, and the function of the field of view angle is as follows:

[0088] FOV=A(k / R)+B

[0089] Wherein, FOV represents the field of view of the light type, and the A value and the B value satisfy the following conditions: -0.1≤A≤-1, and B is a constant greater than 0. For example, the A value is such as but not limited to -0.05, 0 and 0.05, and the B value is such as but not limited to 1, 2.5, 5, 7.5 and 10. In one embodiment, the field of view is between 20° and 150°, such as but not limited to 30°, 40°, 50°, 60°, 70°, 80°, 90°, 100°, 110°, 120°, 130° and 140°. Please refer to Fig.10 , when the light beam is emitted from the microstructure 211 of the optical film 2 and has a maximum angle of 35° relative to the normal of the light incident surface 22, the display device 10A has a light pattern with a viewing angle of 70°, for example. Through the design of the microstructure 211, the light beam can form different emission angles, and the display device 10A can therefore have different viewing angles. It can be seen that the present invention can improve the display brightness at the normal viewing angle by controlling the light pattern. The aforementioned angles and viewing angles are only examples, and the present invention does not impose specific limitations on them.

[0090] Please refer to Figure 2 , Figure 3 and Fig.10As shown, the divergent light beams L1, L2, and L3 have corresponding divergent angles θ1, θ2, and θ3 relative to the normal line C of the light incident surface 22. When the divergent angle θ1=0 degrees, the divergent light beam L1 has a first brightness. In one embodiment of the present invention, when 0 degrees <θ2≦20 degrees or -20 degrees ≦θ2<0 degrees, the divergent light beam L2 has a second brightness, and the second brightness is 90% to 105% of the first brightness, for example, including 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 100%, 101%, 102%, 103%, and 104%. In this way, when the viewing angle of the user is between -20 degrees and 20 degrees, the brightness of the viewing can still be maintained at 90% to 105% of the viewing angle of 0 degrees, thereby improving the situation where the user often has a significantly lower display brightness as the viewing angle increases when viewing images at a normal viewing angle. When θ3≧20 degrees or θ3≦-20 degrees, the divergent light beam L3 has a third brightness. The third brightness is less than the first brightness, for example, less than or equal to 85% of the first brightness. When θ3 increases relative to 20 degrees or decreases relative to -20 degrees, the difference between the third brightness and the first brightness will become larger and larger. For example, the brightness of the divergent light beam L3 of θ3=25 degrees is less than or equal to 85% of the first brightness, and the brightness of the divergent light beam L3 of θ3=35 degrees is less than or equal to 1% of the first brightness. The above relationship between the third brightness and the first brightness is only an example, and the present invention does not impose specific restrictions on this. In this way, when the viewing angle is less than or equal to -20 degrees or greater than or equal to 20 degrees, the brightness of the user's viewing will be smaller than when the viewing angle is 0 degrees, and as the viewing angle increases relative to 20 degrees or decreases relative to -20 degrees, the brightness of the user's viewing will become darker and darker, achieving an anti-peeping effect.

[0091] In another embodiment of the present invention, the divergence angle θ1 = 0 degrees, and the divergent light beam L1 has a first brightness; the divergence angle θ2 is 0 degrees < θ2 ≦ 15 degrees or -15 degrees ≦ θ2 < 0 degrees, and the divergent light beam L2 has a second brightness, which is 95-105% of the first brightness; the divergence angle θ3 is θ3 ≧ 15 degrees or θ3 ≦ 15 degrees, and the divergent light beam L3 has a third brightness, which is less than the first brightness, and when θ3 increases relative to 15 degrees or decreases relative to -15 degrees, the difference between the third brightness and the first brightness will become larger and larger. In another embodiment of the present invention, the divergence angle θ1 = 0 degrees, and the divergent light beam L1 has a first brightness; the divergence angle θ2 is 0 degrees < θ2 ≦ 10 degrees or -10 degrees ≦ θ2 < 0 degrees, and the divergent light beam L2 has a second brightness, which is 95-105% of the first brightness; the divergence angle θ3 is θ3 ≧ 10 degrees or θ3 ≦ 10 degrees, and the divergent light beam L3 has a third brightness, which is less than the first brightness, and when θ3 increases by 10 degrees or decreases by -10 degrees, the difference between the third brightness and the first brightness will become larger and larger. The above divergence angles θ1, θ2, and θ3 are only illustrative, and the present invention does not impose specific limitations on this, and can be adjusted according to needs. In summary, by controlling the light type through the dimming unit AD, the brightness of the divergent light beam L3 with the divergent angle θ3 can be limited, and the brightness of the divergent light beam L2 with the divergent angle θ2 can be increased, thereby reducing the brightness difference between the divergent light beams L1 and L2 corresponding to the divergent angles θ1 and θ2. This can not only achieve an anti-peeping effect on the display, but also improve the viewing comfort of the user at a straight-view angle.

[0092] Figure 6 FIG. 4 is a schematic three-dimensional diagram of a display device according to a second embodiment of the present invention. Figure 7 for Figure 6 The cross-sectional view of the display device of the second embodiment is shown. Figure 6 and 7 The display device 10B of the second embodiment and Figure 2 and 3The display device 10A shown is similar, and the main difference is that the display device 10B further includes a second light emitting unit 5, wherein the second light emitting unit 5 includes a second light guide plate 51 having a plurality of side surfaces 511 and a second light source 52 disposed on at least one side surface 511. In this embodiment, the plurality of second light sources 52 are disposed on one of the plurality of side surfaces 511 of the second light guide plate 51, but the present invention is not limited thereto, and in other embodiments, the plurality of second light sources 52 may also be disposed on the plurality of side surfaces 511 of the second light guide plate 51 at the same time. In addition, the display device 10B of this embodiment can be switched between the anti-peeping mode and the sharing mode. When the display device 10B is in the anti-peeping mode, the first light-emitting unit 4 is turned on but the second light-emitting unit 5 is not turned on, the display device 10B is only provided with light by the first light-emitting unit 4, and the first light source 42 emits an initial light beam I, which passes through the first light guide plate 41, the collimating optical layer 3, and the optical film 2 to form divergent light beams L1, L2, and L3. After the divergent light beam L enters the second light-emitting unit 5 and the display panel 1, the light beam emitted by the first light source 42 is limited by the dimming unit AD to form a first light-emitting light beam L4. When the display device 10B is in the sharing mode, the first light source 41 of the first light-emitting unit 4 and the second light source 52 of the second light-emitting unit 5 are turned on at the same time, the display device 10B is provided with light by the first light-emitting unit 4 and the second light-emitting unit 5. Since the light beam emitted by the second light source 52 does not pass through the dimming unit AD, the light beam emitted by the second light source 52 passes through the display panel 1 to form a second light-emitting light beam L5. The first light beam L4 and the second light beam L5 have a first maximum light angle θ4 and a second maximum light angle θ5 respectively relative to the normal line C on the plane of the display panel 1 away from the light emitting surface 21, and the first maximum light angle θ4 is smaller than the second maximum light angle θ5. By selectively limiting the angle of the light beam, the user is provided with the ability to switch between the anti-peeping mode and the sharing mode as needed. The display device 10B can turn off the second light source 52 to limit the maximum angle of the light beam. For example, the first maximum light angle θ4 can be 10 degrees, 15 degrees, 20 degrees, 25 degrees, 30 degrees, 35 degrees, 40 degrees, and 45 degrees to achieve an anti-peeping effect. The display device 10B can also turn on the second light source 52 and diffuse the light beam through the second light guide plate 51 to expand the maximum angle of the light beam. For example, the second maximum light angle θ5 can be 90 degrees to provide a sharing function. The present invention does not limit the relative arrangement relationship between the first light source 42 and the second light source 52. The two can be relatively arranged on the same side or different sides of the display device 10B. The relationship between the viewing angle and the brightness of the display device 10B of the second embodiment is similar to that of the first embodiment, and will not be described in detail herein.

[0093] Please refer to Figure 8 and 9 The display device 10C according to the third embodiment of the present invention is Figure 2 and 3The display device 10A is similar to the display device 10A, and the main difference is that the first light source 42 of the first light-emitting unit 4 is set at a different position. In the third embodiment, the first light guide plate 41 has an upper surface 412 adjacent to the collimating optical layer 3, and multiple first light sources 42 are arranged on the upper surface 412 of the first light guide plate 41. In addition, in this embodiment, the first light-emitting unit 4 is a direct-down light-emitting unit, but it is not limited to this. In other embodiments, the first light-emitting unit 4 can also be an edge-entry light-emitting unit or a full-array light-emitting unit. In this embodiment, a second light-emitting unit 5 can also be selectively included. Through the configuration of the second light-emitting unit 5, the display device 10C can be set to an anti-peeping mode or a sharing mode as required, and the implementation method is the same as Figure 6 and 7 The relationship between the viewing angle and the brightness of the display device 10B of the third embodiment is similar to that of the first embodiment, and will not be described in detail here.

[0094] In summary, the display devices 10A, 10B, and 10C of the present invention control the light type by designing the collimating optical layer 3 of the dimming unit AD and the microstructure 211 of the optical film 2, thereby limiting the brightness of the divergent light beam L3 with a divergent angle θ3 and increasing the brightness of the divergent light beam L2 with a divergent angle θ2. While achieving a display anti-peeping effect, the display brightness difference between normal viewing angles is reduced, which helps to improve the viewing comfort of the user at the normal viewing angle.

[0095] In addition, the display devices 10A, 10B, and 10C of the present invention can also provide the user with the freedom to switch between the anti-peeping mode and the sharing mode according to needs by providing the second light emitting unit 5. When the first light source 42 is turned on and the second light source 52 is turned off, the angle of the light beam can be limited to provide a display anti-peeping function. When both the first light source 42 and the second light source 52 are turned on, the light beam can be diffused by the second light guide plate 51 to increase the angle of the light beam to achieve an anti-peeping effect.

[0096] Although the present invention has been disclosed as above by way of embodiments, it is not intended to limit the present invention. A person having ordinary knowledge in the technical field to which the present invention belongs 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 scope of the attached patent application.

Claims

1. A dimming unit, characterized in that: include: An optical film has a light emitting surface and a light incident surface opposite to the light emitting surface, wherein the light emitting surface forms a plurality of microstructures, each of the microstructures has a boundary and is connected to the boundary of an adjacent microstructure, wherein the boundary of each microstructure is a polygon in the orthographic projection of the light emitting surface, each of the microstructures has a height h in the normal direction of the light emitting surface, and each of the microstructures also has a virtual aperture in an x-coordinate axis direction parallel to the light emitting surface And the height h is equal to the virtual aperture Ratio 0.2 to 1, and A collimating optical layer is arranged opposite to the light incident surface of the optical film.

2. The dimming unit according to claim 1, characterized in that: in, The height h and the virtual aperture Ratio It is 0.3~0.

7.

3. The dimming unit according to claim 1, wherein: in, Each of the microstructures has a surface profile, and the function of the surface profile is as follows: Wherein, s(x) represents the surface profile of each of the microstructures on the x-axis, the x value represents the vertical projection position of the surface profile on the x-axis, the R value represents a curvature radius of a vertex of each of the microstructures, and the k value represents a cone coefficient of each of the microstructures. Each of the microstructures has the same R value and k value.

4. The dimming unit according to claim 3, characterized in that: in, The ratio of the cone coefficient to the curvature radius (k / R) satisfies the following condition: -187.5 1 / μm≤k / R≤-20 1 / μm.

5. The dimming unit according to claim 3, characterized in that: in, Each of the microstructures is suitable for forming a light pattern, and the light pattern has a viewing angle, and the function of the viewing angle is as follows: FOV=A(k / R)+B Wherein, FOV represents the field of view of the light type, and the A value and the B value satisfy the following conditions: -0.1≤A≤-1, and B is a constant greater than 0.

6. The dimming unit according to claim 3, characterized in that: in, The cone coefficient k satisfies the following condition: -1.5≤k≤-0.

8.

7. The dimming unit according to claim 3, characterized in that: in, The curvature radius R satisfies the following condition: 0.008 μm ≤ R ≤ 0.04 μm.

8. The dimming unit according to claim 1, wherein: in, The virtual aperture of each of the microstructures The following conditions are met:

9. The dimming unit according to claim 3, characterized in that: in, The virtual aperture of each of the microstructures It is the difference between two adjacent x values ​​when s(x) of the surface profile function is 0 and satisfies the following conditions:

10. The dimming unit according to claim 1, wherein: in, The height h of each of the microstructures satisfies the following condition: 10 μm≤h≤50 μm.

11. The dimming unit according to claim 3, characterized in that: in, The height h of each of the microstructures is the maximum value of s(x) of the function of the surface profile and satisfies the following condition: 10 μm≤h≤50 μm.

12. The dimming unit according to claim 1, wherein: in, The microstructures are protruding from or recessed into the light emitting surface.

13. The dimming unit according to claim 1, wherein: in, The material of the optical film can be polycarbonate, polyethylene terephthalate, polypropylene, polyvinyl chloride, polydimethylsiloxane or a combination thereof.

14. The dimming unit according to claim 1, wherein: in, The collimating optical layer is a privacy film or a lens.

15. A display device, characterized in that: include: A dimming unit as claimed in any one of claims 1 to 14, a display panel, disposed opposite to the light emitting surface of the optical film; as well as a first light-emitting unit, arranged opposite to the collimating optical layer of the dimming unit, and the dimming unit is located between the display panel and the first light-emitting unit, Among them, the first light-emitting unit emits an initial light beam to the collimating optical layer, and the initial light beam forms a collimated light beam after passing through the collimating optical layer. After the collimated light beam enters the optical film through the light incident surface, it is emitted from the microstructures of the light emitting surface to form a divergent light beam, and the divergent light beam has a divergence angle relative to a normal line of the light incident surface.

16. The display device according to claim 15, characterized in that in, The first light emitting unit comprises: a first light guide plate having at least one side surface; and at least one first light source disposed on the at least one side surface of the first light guide plate.

17. The display device according to claim 15, characterized in that: in, The first light emitting unit comprises: a first light guide plate having an upper surface adjacent to the collimating optical layer; and at least one first light source disposed on the upper surface of the first light guide plate.

18. The display device according to claim 15, characterized in that: The display device further includes a second light emitting unit disposed between the display panel and the optical film, wherein the second light emitting unit includes a second light guide plate and at least one second light source disposed on at least one side surface of the second light guide plate, wherein the display device can switch between multiple modes, including: an anti-peeping mode, when the first light-emitting unit is turned on and the second light-emitting unit is turned off, the divergent light beam passes through the second light-emitting unit and the display panel to form a first light-emitting light beam, and the first light-emitting light beam has a first maximum light-emitting angle relative to a normal line on a plane of the display panel away from the light-emitting surface; and In a sharing mode, when the first light-emitting unit is turned on and the second light-emitting unit is turned on, at least one light beam emitted by the second light-emitting unit passes through the second light-emitting unit and the display panel to form a second light-emitting light beam, and the second light-emitting light beam has a second maximum light-emitting angle relative to a normal on a plane of the display panel away from the light-emitting surface, and the first maximum light-emitting angle is smaller than the second maximum light-emitting angle.

19. The display device according to claim 15, wherein: in, When the divergence angle θ is 0 degrees, the divergent light beam has a first brightness; when 0 degrees <θ ≦ 20 degrees or -20 degrees ≦θ < 0 degrees, the divergent light beam has a second brightness, and the second brightness is 90% to 105% of the first brightness.

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