Viewing angle control film and display device

Abstract

A viewing angle control film comprises a light-transmitting substrate and a plurality of first optical microstructures. The first optical microstructures are arranged on the surface of the light-transmitting substrate, and the arrangement range of the first optical microstructures has a geometric center. Each first optical microstructure is provided with a first refraction surface deviating from the geometric center. The angles of first refraction angles between the first refraction surfaces of the first optical microstructures and the surface of the light-transmitting substrate are asymmetrically distributed relative to the geometric center. The light emitting brightness of different positions of the visual angle control film provided by the invention has better uniformity for a specific light receiving position. A display device using the viewing angle control film is also provided. The display frame of the display device provided by the invention has better brightness uniformity for a specific viewing position.

Description

Technical Field

[0001] The invention relates to an anti-peeping display technology, and in particular to a viewing angle control film and a display device. Background Art

[0002] Generally speaking, in order to allow multiple viewers to watch together, display devices usually have a wide viewing angle display effect. However, in some situations or occasions, such as browsing private web pages, confidential information or entering passwords in public places, the wide viewing angle display effect can easily cause confidential information to be peeped by others and leaked.

[0003] In order to achieve the anti-peeping effect, the general practice is to place a light control film (LCF) in front of the display panel to filter out light at a large angle. Therefore, the better the anti-peeping effect, the smaller the viewing angle range. However, for a display with a large display size, a too narrow viewing angle can easily cause the image brightness to decrease in the outer area (such as the left and right sides of the image in the anti-peeping direction), thereby reducing the image quality of the anti-peeping display. Summary of the invention

[0004] The present invention provides a viewing angle control film, the light output brightness at different positions of the film has better uniformity with respect to a specific light receiving position.

[0005] The invention provides a display device, the brightness uniformity of the display picture of which is better for a specific viewing position.

[0006] To achieve one or part or all of the above purposes or other purposes, one embodiment of the present invention provides a viewing angle control film. The viewing angle control film includes a transparent substrate and a plurality of first optical microstructures. These first optical microstructures are arranged on the surface of the transparent substrate, and their arrangement range has a geometric center. Each first optical microstructure has a first refractive surface that deviates from the geometric center. The angles of the first refractive angles between the first refractive surfaces of each of these first optical microstructures and the surface of the transparent substrate are asymmetrically distributed relative to the geometric center.

[0007] 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 viewing angle control film and a display panel. The display panel is arranged on one side of the viewing angle control film. The viewing angle control film includes a light-transmitting substrate and a plurality of first optical microstructures. These first optical microstructures are arranged on the surface of the light-transmitting substrate, and their arrangement range has a geometric center. Each first optical microstructure has a first refractive surface that deviates from the geometric center. The angles of the first refractive angles between the first refractive surfaces of each of these first optical microstructures and the surface of the light-transmitting substrate are asymmetrically distributed relative to the geometric center.

[0008] Based on the above, in the viewing angle control film of one embodiment of the present invention, each of the plurality of first optical microstructures has a refractive surface on the side away from the geometric center of the setting range thereof, and the first refractive angles between the refractive surfaces of each of the first optical microstructures and the surface of the light-transmitting substrate are asymmetrically distributed relative to the geometric center. Through such a configuration, light can be directed to a specific light receiving position after passing through different positions of the viewing angle control film, thereby improving the uniformity of the overall light output brightness at the specific position. Therefore, the display screen of the display device provided with the above viewing angle control film can have better brightness uniformity at a specific viewing position. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0010] Figure 2 yes Figure 1 Schematic diagram of the viewing angle control film.

[0011] Figure 3 yes Figure 2 Schematic cross-sectional view of a viewing angle control film.

[0012] Figure 4A yes Figure 3 Schematic diagram of the distribution of the refractive angle of the first optical microstructure at different positions.

[0013] Figure 4B yes Figure 4A Schematic diagram of the distribution of the refractive angle of the first optical microstructure at different positions in some other variant embodiments.

[0014] Figure 5A and Figure 5B yes Figure 3 Schematic diagram of the distribution of normalized brightness versus viewing angle of the viewing angle control film at different light output positions.

[0015] Figure 6 yes Figure 1 Schematic diagram of the distribution of normalized brightness of a display device and a display device of a comparative example at different positions on the display screen.

[0016] Figure 7 is a three-dimensional schematic diagram of a viewing angle control film according to another embodiment of the present invention.

[0017] Figure 8 yes Figure 7 Schematic cross-sectional view of a viewing angle control film.

[0018] Fig. 9A yes Figure 8 Schematic diagram of the distribution of the refractive angle of the first optical microstructure at different positions.

[0019] Fig. 9B yes Fig. 9A A schematic diagram of the distribution of the refractive angle of the first optical microstructure at different positions in another variant embodiment.

[0020] Fig.10 Is adopted Figure 8 A display device using a viewing angle control film Fig. 12A Schematic diagram of the distribution of normalized brightness of another display device with two viewing angle control films and a display device of a comparative example versus different positions on the display screen.

[0021] Fig.11 is a schematic diagram of a display device according to a second embodiment of the present invention.

[0022] Fig. 12A and Fig. 12B yes Fig.11 Enlarged schematic diagrams of two viewing angle control films in different directions.

[0023] Fig.13 yes Fig. 12A and Fig. 12B Schematic diagram of the distribution of the refractive angle of the first optical microstructure of two viewing angle control films at different positions.

[0024] Fig.14 FIG. 4 is a three-dimensional schematic diagram of a viewing angle control film according to another embodiment of the present invention.

[0025] Fig.15A and Fig. 15B yes Fig.14 Schematic diagram of the cross-section of the viewing angle control film in different directions.

[0026] Fig.16 yes Figure 8 A cross-sectional schematic diagram of a viewing angle control film according to another variant embodiment of the present invention.

[0027] Fig.17A and Fig. 17B yes Figure 7 Schematic top view of viewing angle control films of other modified embodiments.

[0028] Fig.18 is a schematic diagram of a display device according to a third embodiment of the present invention.

[0029] Fig.19 is a schematic diagram of a display device according to a fourth embodiment of the present invention.

[0030] Description of reference numerals:

[0031] 10, 10A, 10B, 20: Display device

[0032] 100, 100A, 100B, 100C, 100D, 100E: Viewing angle control film

[0033] 101: Translucent substrate

[0034] 101s, 101s”: Surface

[0035] 150: Optical auxiliary layer

[0036] 180: Anisotropic diffuser

[0037] 200: Electronically controlled viewing angle switcher

[0038] DP: Display Panel

[0039] DSa, DSb, DSa-A, DSb-A, DS1a, DS1b, DS2a, DS2b: Refractive surface

[0040] GC: Geometric Center

[0041] IP1, IP2: Virtual plane

[0042] MS, MSa, MSb, MS-A, MSa-A, MSb-A, MS1, MS1a, MS1b, MS2, MS2a, MS2b, MS-B, MS-C: Optical microstructures

[0043] SSa, SSb, SSa-A, SSb-A, SS1a, SS1b, SS2a, SS2b: Structural planes

[0044] X, Y: direction

[0045] α, θ, θ', α1, α2, θ1, θ2: refractive angle

[0046] β, β1, β2, Structural angle. DETAILED DESCRIPTION

[0047] The other technical contents, features and effects of the present invention described above 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.

[0048] Figure 1 is a schematic diagram of a display device according to a first embodiment of the present invention. Figure 2 yes Figure 1 Schematic diagram of the viewing angle control film. Figure 3 yes Figure 2Schematic cross-sectional view of a viewing angle control film. Figure 4A yes Figure 3 Schematic diagram of the distribution of the refractive angle of the first optical microstructure at different positions. Figure 4B yes Figure 4A Schematic diagram of the distribution of the refractive angle of the first optical microstructure at different positions in some other variant embodiments. Figure 5A and Figure 5B yes Figure 3 Schematic diagram of the distribution of normalized brightness versus viewing angle of the viewing angle control film at different light output positions.

[0049] Figure 6 yes Figure 1 Schematic diagram of the distribution of normalized brightness of a display device and a display device of a comparative example at different positions on the display screen.

[0050] Please refer to Figure 1 The display device 10 includes a viewing angle control film 100, an electrically controlled viewing angle switch 200 and a display panel DP. The display panel DP is disposed on one side of the viewing angle control film 100. The electrically controlled viewing angle switch 200 overlaps the viewing angle control film 100 and the display panel DP.

[0051] In the present embodiment, the display panel DP may be a non-self-luminous display panel (e.g., a liquid crystal display panel, but not limited thereto). Correspondingly, the display device 10 may also be provided with a backlight module BLU as an illumination light source for the non-self-luminous display panel, wherein the backlight module BLU may be an edge-entry backlight module (e.g., a combination of a light guide plate and an edge-entry light source) or a direct-type backlight module (e.g., a light emitting diode panel or an array of light strips). However, the present invention is not limited thereto. In other embodiments, the display panel DP may also be a self-luminous display panel, and the viewing angle control film 100 is disposed on one side of the display surface of the display panel DP (e.g., Figure 1 The upper side of the display panel DP).

[0052] In this embodiment, the electrically controlled viewing angle switch 200 may be selectively disposed between the display panel DP and the backlight module BLU, but is not limited thereto. In other embodiments, the electrically controlled viewing angle switch 200 may also be disposed on the side of the display panel DP away from the backlight module BLU. For example, the electrically controlled viewing angle switch 200 may be an electrically controlled liquid crystal box with polarization modulation capability, an electrophoretic electrically controlled privacy film, or an electrically controlled privacy film with photochromic properties, but is not limited thereto.

[0053] Please refer to Figure 2 and Figure 3In detail, the viewing angle control film 100 includes a transparent substrate 101 and a plurality of optical microstructures MS. In the present embodiment, the plurality of optical microstructures MS are disposed on a surface 101s of the transparent substrate 101, and the plurality of optical microstructures MS may be arranged along a direction X and extend in a direction Y, wherein the direction X intersects (e.g., is perpendicular to) the direction Y. For example, in the present embodiment, the optical microstructures MS of the viewing angle control film 100 may be disposed away from the backlight module BLU, but is not limited thereto. In other embodiments, the optical microstructures MS may be disposed toward the backlight module BLU.

[0054] It is particularly noted that the arrangement range of the plurality of optical microstructures MS on the transparent substrate 101 has a geometric center GC, and the optical microstructures MS include those arranged on one side of the geometric center GC (eg Figure 2 The optical microstructures MSa are arranged on the left side of the geometric center GC and the optical microstructures MSa are arranged on the other side of the geometric center GC (for example Figure 2 Multiple optical microstructures MSb) on the right side of the geometric center GC.

[0055] For example, in the present embodiment, the distribution range of each optical microstructure MSa located on one side of the geometric center GC is symmetrically arranged with respect to the geometric center GC with respect to one of the multiple optical microstructures MSb located on the other side of the geometric center GC. That is, the number of optical microstructures MSa located on one side of the geometric center GC may be equal to the number of optical microstructures MSb located on the other side of the geometric center GC, and the symmetric relationship between the multiple optical microstructures MSa and the multiple optical microstructures MSb is one-to-one. However, the present invention is not limited thereto. In other embodiments not shown, the number of optical microstructures MSa located on one side of the geometric center GC may be different from the number of optical microstructures MSb located on the other side of the geometric center GC.

[0056] More specifically, the symmetric relationship between the multiple optical microstructures MSa and the multiple optical microstructures MSb of the present embodiment is relative to a virtual plane IP1, wherein the virtual plane passes through the geometric center GC and is perpendicular to the direction X. Since the multiple optical microstructures MS of the present embodiment extend in the direction Y, each of these optical microstructures MS is also symmetrically arranged relative to another virtual plane (not shown), which passes through the geometric center GC and is perpendicular to the direction Y.

[0057] Specifically, the optical microstructures MSa each have a refractive surface DSa away from the geometric center GC, and the optical microstructures MSb each have a refractive surface DSb away from the geometric center GC. That is, the optical microstructures MSa and MSb located on opposite sides of the geometric center GC have refractive surfaces DSa and DSb away from each other.

[0058] In this embodiment, the angles of refraction angles between the refraction surfaces of the plurality of optical microstructures MS and the surface 101s of the transparent substrate 101 are symmetrically distributed relative to the geometric center GC. More specifically, the angles of refraction angles between the refraction surfaces of the two optical microstructures MSa and MSb, which are respectively arranged on opposite sides of the geometric center GC and whose distribution ranges are symmetrically arranged relative to the geometric center GC (i.e., equidistantly arranged relative to the geometric center GC) and the surface 101s of the transparent substrate 101, can be selectively the same. For example: the refraction surface DSa of the optical microstructure MSa on the left side of the geometric center GC and farthest from the geometric center GC and the optical microstructure MSb on the right side of the geometric center GC and farthest from the geometric center GC have the same refraction angle θ, and so on.

[0059] Please refer to Figure 3 and Figure 4A , the angle of the refraction angle θ of the optical microstructure MS decreases as its distribution position approaches the geometric center GC. For example, in this embodiment, the distribution of the refraction angle θ of the optical microstructure MS to the position is linear, such as Figure 4A In other embodiments, the distribution of the refraction angle θ of the optical microstructure MS to the position may also be exponential (eg Figure 4B PD) or a polynomial relationship (such as Figure 4B ED).

[0060] On the other hand, each of the multiple optical microstructures MSa also has a structural surface SSa facing the geometric center GC, and each of the multiple optical microstructures MSb also has a structural surface SSb facing the geometric center GC. That is, the optical microstructures MSa and the optical microstructures MSb located on opposite sides of the geometric center GC have structural surfaces SSa and structural surfaces SSb facing each other, respectively. The structural angle between the structural surfaces of each of the multiple optical microstructures MS and the surface 101s of the transparent substrate 101 can be greater than or equal to the angle of its refraction angle θ.

[0061] In the present embodiment, the angles of the structural angles between the structural surfaces of the plurality of optical microstructures MS and the surface 101s of the light-transmitting substrate 101 are symmetrically distributed relative to the geometric center GC. More specifically, the angles of the structural angles between the structural surfaces of the two optical microstructures MSa and MSb, which are respectively arranged on opposite sides of the geometric center GC and whose distribution ranges are symmetrically arranged relative to the geometric center GC (i.e., equidistantly arranged relative to the geometric center GC) and the surface 101s of the light-transmitting substrate 101, can be selectively the same. For example: the structural surface SSa of the optical microstructure MSa on the left side of the geometric center GC and farthest from the geometric center GC and the optical microstructure MSb on the right side of the geometric center GC and farthest from the geometric center GC have the same structural angles. And so on.

[0062] In this embodiment, the structural angle of the optical microstructure MS is As the distribution position approaches the geometric center GC, the structure angles of the plurality of optical microstructures MS decrease gradually, but are not limited thereto. They can also be the same as each other, that is, the structural angle of the optical microstructure MS Does not vary depending on where it is set.

[0063] Figure 5A and Figure 5B Shown in Figure 1 The distribution curves of normalized brightness versus viewing angle obtained at the center of the display device 10 and the leftmost and rightmost light exit positions parallel to the direction X. Please refer to Figure 3 and Figure 5A For example, when light (not shown) enters the optical microstructure MSa located on the left side of the geometric center GC of the viewing angle control film 100 from the lower side or upper side of the viewing angle control film 100 in a manner that is normal to the surface 101s of the transparent substrate 101, the refractive surface DSa of the optical microstructure MSa on the left side can deflect the light toward the center of the viewing angle control film 100 (i.e., deflect to the right). Therefore, the central viewing angle of the light output distribution of the light passing through the optical microstructure MSa located on the left side of the geometric center GC will deviate to the right relative to the position of the viewing angle 0 degree (e.g., Figure 5A As shown by the curve LV). Since the optical microstructure MS closest to the geometric center GC has the smallest refraction angle θ close to 0 degrees, the central viewing angle of the light distribution after the light passes through will not produce a significant deviation relative to the position of the viewing angle 0 degrees (as shown in FIG. Figure 5A The curve CV is shown in Figure 2).

[0064] Please refer to Figure 3 and Figure 5B Similarly, when light enters the optical microstructure MSb of the viewing angle control film 100 located on the right side of the geometric center GC from the bottom or top side of the viewing angle control film 100 in a manner that is normal to the surface 101s of the transparent substrate 101, the refractive surface DSb of the optical microstructure MSb on the right side can deflect the light toward the center of the viewing angle control film 100 (i.e., deflect to the left). Therefore, the central viewing angle of the light output distribution of the light passing through the optical microstructure MSb located on the right side of the geometric center GC will deviate to the left relative to the position of the viewing angle 0 degree (e.g., Figure 5B RV).

[0065] More specifically, the configuration of the optical microstructures MSa and MSb on opposite sides of the geometric center GC can guide the light passing through different positions of the viewing angle control film 100 away from the geometric center GC to a specific light receiving position (e.g., a position on the optical axis passing through the geometric center GC and axially perpendicular to the surface 101s of the transparent substrate 101). Therefore, the light uniformity of the viewing angle control film 100 as a whole for a specific or single light receiving position can be effectively improved.

[0066] Figure 6 The curve E1 is a distribution curve of normalized brightness measured at a position facing the display center of the display device 10 of the present embodiment at different positions on the display screen, and the curve C1 is a distribution curve of normalized brightness measured at a position facing the display center of the display device of the comparative example at different positions on the display screen. The display device of the comparative example is similar to the display device 10 of the present embodiment except that the viewing angle control film 100 of the present embodiment is not provided. The normalized brightness in the figure is the percentage value of the brightness measured at each position on the display device to the maximum brightness measured at these positions.

[0067] Depend on Figure 6 It can be seen that the light output brightness of the display device 10 of this embodiment in the area deviated from the display center is significantly higher than that of the display device of the comparative example, and the overall light output uniformity is also better. In other words, the display device 10 of this embodiment is provided with the aforementioned viewing angle control film 100, so that the display screen at a specific viewing position can have better brightness uniformity.

[0068] Another embodiment will be listed below to explain 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 above embodiment and will not be repeated below.

[0069] Figure 7 is a three-dimensional schematic diagram of a viewing angle control film according to another embodiment of the present invention. Figure 8 yes Figure 7 Schematic cross-sectional view of a viewing angle control film. Fig. 9A yes Figure 8 Schematic diagram of the distribution of the refractive angle of the first optical microstructure at different positions. Fig. 9B yes Fig. 9A A schematic diagram of the distribution of the refractive angle of the first optical microstructure at different positions in another variant embodiment. Fig.10 Is adopted Figure 8 A display device using a viewing angle control film Fig. 12A Schematic diagram of the distribution of normalized brightness of another display device with two viewing angle control films and a display device of a comparative example versus different positions on the display screen.

[0070] Please refer to Figure 7and Figure 8 , different from Figure 2 and Figure 3 In the viewing angle control film 100 of the embodiment, the refraction angle between the refraction surface of the optical microstructure MS-A of the viewing angle control film 100A and the surface 101s of the transparent substrate 101 is asymmetrically distributed relative to the geometric center GC.

[0071] More specifically, the angles of refraction angles between the refraction surfaces of the two optical microstructures MSa-A and MSb-A, which are respectively arranged on opposite sides of the geometric center GC and whose distribution ranges are symmetrically arranged relative to the geometric center GC (i.e., arranged equidistantly relative to the geometric center GC) and the surface 101s of the transparent substrate 101, can be selectively different. For example, the angle of refraction angle α of the refraction surface DSa-A of the optical microstructure MSa-A on the left side of the geometric center GC and farthest from the geometric center GC can be greater than the angle of refraction angle θ of the refraction surface DSb-A of the optical microstructure MSb-A on the right side of the geometric center GC and farthest from the geometric center GC, and so on.

[0072] Please refer to Figure 8 and Fig. 9A , the refraction angle α of the optical microstructure MSa-A and the refraction angle θ of the optical microstructure MSb-A will gradually decrease as their distribution positions approach the geometric center GC. For example, in this embodiment, the distribution of the refraction angle α of the optical microstructure MSa-A and the refraction angle θ of the optical microstructure MSb-A with respect to the position is linearly related, such as Fig. 9A shown.

[0073] It is particularly noted that although the distribution of the refractive angle of the optical microstructure MS-A of this embodiment is similar to Figure 3 and Figure 4A The viewing angle control film 100 is linearly related, but the slope of the linear relationship between the refractive angle α of the optical microstructure MSa-A located on the left side of the geometric center GC and the position may be greater than the slope of the linear relationship between the refractive angle θ of the optical microstructure MSb-A located on the right side of the geometric center GC and the position. That is, the linear relationship between the refractive angle α of the optical microstructure MSa-A and the linear relationship between the refractive angle θ of the optical microstructure MSb-A and the position may be asymmetrically distributed relative to the position of the geometric center GC.

[0074] However, the present invention is not limited thereto. In another embodiment, although the distribution relationship of the angle of refraction of each of the plurality of optical microstructures relative to the position of the geometric center GC is also asymmetrically distributed, the angle distribution of the refraction angles of these optical microstructures has a minimum value at a position Pm, and this position Pm may not overlap with or deviate from the geometric center GC (e.g. Fig. 9B That is, the refraction angles of these optical microstructures gradually decrease as they approach the position Pm.

[0075] On the other hand, in the present embodiment, the structural angle β between the structural surface SSa-A of each of the plurality of optical microstructures MSa-A and the surface 101s of the transparent substrate 101 may be equal to or different from the structural angle β between the structural surface SSb-A of each of the plurality of optical microstructures MSb-A and the surface 101s of the transparent substrate 101. The structural angle between the structural surface of each optical microstructure MS-A and the surface 101s of the light-transmitting substrate 101 may be greater than or equal to the refraction angle thereof.

[0076] In this embodiment, the structural angle β of the optical microstructure MSa-A decreases as its distribution position approaches the geometric center GC, and the structural angle β of the optical microstructure MSb-A decreases as its distribution position approaches the geometric center GC. As the distribution position approaches the geometric center GC, the angle β of each of the multiple optical microstructures MSa-A may be the same as each other, and the angle β of each of the multiple optical microstructures MSb-A may be the same as each other. That is, the structural angle β of the optical microstructure MSa-A does not vary with its arrangement position, and the structural angle β of the optical microstructure MSb-A Does not vary depending on where it is set.

[0077] It is worth mentioning that the asymmetric configuration of the optical microstructures MSa-A and the optical microstructures MSb-A on opposite sides of the geometric center GC can guide the light passing through different positions of the viewing angle control film 100A from the geometric center GC to a specific light receiving position, and this specific light receiving position is, for example, a position on the right side of the optical axis passing through the geometric center GC and axially perpendicular to the surface 101s of the transparent substrate 101. Therefore, the light uniformity of the viewing angle control film 100A as a whole for a specific or single light receiving position can be effectively improved.

[0078] More specifically, the viewing angle control film 100A of this embodiment can be applied to a display device with a single-side anti-peeping function, such as a car display, but is not limited thereto. For example, in order to avoid the interference of the car display on driving during nighttime driving, such a car display can be operated in an anti-peeping mode (i.e., a mode in which only the passengers in the front passenger seat and the rear seat can watch). Applying the viewing angle control film 100A of this embodiment to such a display device can greatly improve the problem of the dark display screen on the anti-peeping side.

[0079] Fig.10The curve C2 is a distribution curve of normalized brightness measured at the display center of the display device of the comparative example (e.g., a display device with a single-side privacy protection function) at different positions on the display screen, and the curve E2 is a distribution curve of normalized brightness measured at the display center of the display device of the present embodiment at different positions on the display screen. It should be noted that the display device of the present embodiment is, for example, a combination of the display device of the comparative example and the viewing angle control film 100A. The normalized brightness in the figure is the percentage value of the brightness measured at each position on the display device to the maximum brightness measured at these positions.

[0080] Depend on Fig.10 It can be seen that the display device of this embodiment has a large area deviating from the display center (for example Fig.10 The light output brightness of the left area of ​​the display device (i.e., the anti-peeping side) is significantly higher than that of the display device of the comparative example, and the overall light output uniformity is also better. In other words, the display device of this embodiment is provided with the aforementioned viewing angle control film 100A, so that the display screen at a specific viewing position (such as the passenger seat or the back seat of the aforementioned vehicle) can have better brightness uniformity.

[0081] Fig.11 is a schematic diagram of a display device according to a second embodiment of the present invention. Fig. 12A and Fig. 12B yes Fig.11 Enlarged schematic diagrams of two viewing angle control films in different directions. Fig.13 yes Fig. 12A and Fig. 12B Schematic diagram of the distribution of the refractive angle of the first optical microstructure of two viewing angle control films at different positions.

[0082] Please refer to Fig.11 , Fig. 12A and Fig. 12B , different from Figure 1 The display device 10A of this embodiment may include two viewing angle control films, such as Figure 3 The viewing angle control film 100 and Figure 8 The viewing angle control film 100A. It should be noted that, in the present embodiment, the angle of refraction θ of the viewing angle control film 100 may be different from the angle of refraction θ' and the angle of refraction α of the viewing angle control film 100A. Therefore, the refraction angle of the optical microstructure MSb-A of the viewing angle control film 100A of the present embodiment is changed to θ' to distinguish the refraction angle θ of the optical microstructure MSb of the viewing angle control film 100.

[0083] In this embodiment, the viewing angle control film 100A may be located between the viewing angle control film 100 and the backlight module BLU, but is not limited thereto. In other embodiments, the viewing angle control film 100A may also be disposed between the viewing angle control film 100 and the electrically controlled viewing angle switch 200, or on the side of the display panel DP away from the backlight module BLU.

[0084] It is particularly noted that in this embodiment, the extension direction of the optical microstructures MS of the viewing angle control film 100 intersects with the extension direction of the optical microstructures MS-A of the viewing angle control film 100A. For example, the plurality of optical microstructures MS of the viewing angle control film 100 may be arranged along the direction Y and extend in the direction X, while the plurality of optical microstructures MS-A of the viewing angle control film 100A may be arranged along the direction X and extend in the direction Y (e.g., Fig. 12A , 12B ), but not limited thereto, the plurality of optical microstructures MS may be arranged along direction X and extend in direction Y, while the plurality of optical microstructures MS-A of the viewing angle control film 100A may be arranged along direction Y and extend in direction X. That is, the extension directions of the optical microstructures of the two viewing angle control films may be perpendicular to each other.

[0085] From another point of view, the multiple optical microstructures MSa-A and the multiple optical microstructures MSb-A of the viewing angle control film 100A are asymmetrically arranged relative to the virtual plane IP1, while the multiple optical microstructures MSa and the multiple optical microstructures MSb of the viewing angle control film 100 are symmetrically arranged relative to the virtual plane IP2, wherein the virtual plane IP1 passes through the geometric center GC of the viewing angle control film 100A and is perpendicular to the direction X, and the virtual plane IP2 passes through the geometric center GC of the viewing angle control film 100 and is perpendicular to the direction Y.

[0086] Since the viewing angle control film 100 and the viewing angle control film 100A of the present embodiment are similar to Figure 3 The viewing angle control film 100 and Figure 8 For detailed description of the viewing angle control film 100A, please refer to the relevant paragraphs of the aforementioned corresponding embodiments, which will not be repeated here.

[0087] Fig.13 The distribution relationship of the refractive angles of the optical microstructure MS-A of the viewing angle control film 100A (for example, the refractive angle α of the optical microstructure MSa-A and the refractive angle θ' of the optical microstructure MSb-A) at different positions along the direction X and the distribution relationship of the refractive angles of the optical microstructure MS of the viewing angle control film 100 (for example, the refractive angle θ of the optical microstructure MSa and the refractive angle θ' of the optical microstructure MSb) at different positions along the direction Y are shown.

[0088] More specifically, the refractive angles between the refractive surfaces of the plurality of optical microstructures MS of the viewing angle control film 100 and the surface 101s of the transparent substrate 101 are symmetrically distributed along the direction Y relative to the geometric center GC (eg Fig. 12B As shown), the refraction angle between the refraction surface of the optical microstructure MS-A of the viewing angle control film 100A and the surface 101s of the transparent substrate 101 is asymmetrically distributed along the direction X relative to the geometric center GC (as shown Fig. 12A shown).

[0089] Fig.10 The curve E3 is a distribution curve of normalized brightness measured at a position facing the display center of the display device 10A of this embodiment to different positions on the display screen. In addition to the viewing angle control film 100A that can guide light to a specific position at different positions in the direction X, the display device 10A of this embodiment is also equipped with a viewing angle control film 100 that can guide light to the specific position at different positions in the direction Y. Therefore, compared with the performance of the display device using only the viewing angle control film 100A (such as Fig.10 As shown in the curve E2, the brightness uniformity of the entire display screen of the display device 10A at the specific position can be further improved (as shown in the curve E3). Fig.10 (as shown by curve E3).

[0090] Fig.14 FIG. 4 is a three-dimensional schematic diagram of a viewing angle control film according to another embodiment of the present invention. Fig.15A and Fig. 15B yes Fig.14 Schematic diagram of the cross-section of the viewing angle control film in different directions. Please refer to Fig.14 , Fig.15A and Fig. 15B , different from Fig.11 The two viewing angle control films 100 and 100A used in the display device 10A are structurally separated from each other. In this embodiment, the viewing angle control film 100B has the refractive power in both the X direction and the Y direction.

[0091] For example, in this embodiment, the viewing angle control film 100B includes a plurality of first optical microstructures MS1 and a plurality of second optical microstructures MS2, and these optical microstructures are disposed on the surface 101s of the light-transmitting substrate 101. More specifically, the disposition range of these first optical microstructures MS1 overlaps with the disposition range of these second optical microstructures MS2, and the extension direction (e.g., direction Y) of the first optical microstructures MS1 intersects with the extension direction (e.g., direction X) of the second optical microstructures MS2.

[0092] In the viewing angle control film 100B of the present embodiment, the refractive angles (i.e., first refractive angles) of the plurality of first optical microstructures MS1 are asymmetrically distributed along direction X relative to the geometric center GC or a virtual plane IP1 passing through the geometric center GC, and the refractive angles (i.e., second refractive angles) of the plurality of second optical microstructures MS2 are symmetrically distributed along direction Y relative to the geometric center GC or a virtual plane IP2 passing through the geometric center GC. For example, in direction X, the angle of refraction angle α1 between the refractive surface DS1a of the first optical microstructure MS1a located on one side of the geometric center GC and farthest from the geometric center GC and the surface 101s of the transparent substrate 101 is different from the angle of refraction angle θ1 between the refractive surface DS1b of the first optical microstructure MS1b located on the other side of the geometric center GC and farthest from the geometric center GC and the surface 101s of the transparent substrate 101, and in direction Y, the angle of refraction angle α2 between the refractive surface DS2a of the second optical microstructure MS2a located on one side of the geometric center GC and farthest from the geometric center GC and the surface 101s of the transparent substrate 101 is equal to the angle of refraction angle θ2 between the refractive surface DS2b of the second optical microstructure MS2b located on the other side of the geometric center GC and farthest from the geometric center GC and the surface 101s of the transparent substrate 101.

[0093] However, the present invention is not limited thereto. In other embodiments, the refraction angles of the plurality of second optical microstructures may be distributed asymmetrically along the direction Y relative to the geometric center GC.

[0094] Since the structural angle β1 between the structural surface SS1a of the first optical microstructure MS1a and the surface 101s of the transparent substrate 101 and the structural angle β2 between the structural surface SS1b of the first optical microstructure MS1b and the surface 101s of the transparent substrate 101 are The structural angle β2 between the structural surface SS2a of the second optical microstructure MS2a and the surface 101s of the transparent substrate 101 and the structural angle β1 between the structural surface SS2b of the second optical microstructure MS2b and the surface 101s of the transparent substrate 101 The configuration is similar to Figure 8 The structural angle β and the structural angle θ of the optical microstructure MS-A of the viewing angle control film 100A and Figure 3 The structural angle of the optical microstructure MS of the viewing angle control film 100 For detailed description, please refer to the relevant paragraphs of the aforementioned embodiments, which will not be repeated here.

[0095] Fig.16 yes Figure 8 A cross-sectional view of a viewing angle control film of another variant embodiment is shown. Fig.16 The viewing angle control film 100C of this embodiment is Figure 8 The difference between the viewing angle control film 100A and the viewing angle control film 100C of the present embodiment is that the viewing angle control film 100C of the present embodiment may further selectively include an optical auxiliary layer 150, which is disposed on a surface 101s" on the side of the light-transmitting substrate 101 away from the optical microstructure MS-A. For example, the optical auxiliary layer 150 may be a matte layer (Matt layer), an anti-glare layer (AG) or a microstructure layer, but is not limited thereto. Through the provision of the optical auxiliary layer 150, the concealing property or visual effect of the display device using the viewing angle control film 100C may be improved.

[0096] Fig.17A and Fig. 17B yes Figure 7 Schematic top view of the viewing angle control film of other variant embodiments. Figure 7 The optical microstructure of the viewing angle control film 100A is a microstructure extending on one side of the geometric center GC. In a viewing angle control film 100D of a modified embodiment, a plurality of optical microstructures MS-B can be arranged around the geometric center GC of the setting range thereof, and the orthographic projection profile of each optical microstructure MS-B on the transparent substrate 101 is a rectangle (such as Fig.17A In another variant embodiment of the viewing angle control film 100E, the orthographic projection profiles of the multiple optical microstructures MS-C on the transparent substrate 101 can also be multiple concentric circles (such as Fig. 17B shown).

[0097] Fig.18 is a schematic diagram of a display device according to a third embodiment of the present invention. Fig.18 The display device 10B of this embodiment is Figure 1 The difference between the display device 10B and the display device 10B is that the viewing angle control film is disposed at a different position. Specifically, in the display device 10B of the present embodiment, the viewing angle control film 100 is disposed at a side of the display panel DP away from the backlight module BLU.

[0098] Fig.19 is a cross-sectional schematic diagram of a display device according to a fourth embodiment of the present invention. Fig.19 The display device 20 of this embodiment and Figure 1 The difference between the display device 10 of the embodiment is that the display device 20 of the embodiment may further selectively include an anisotropic diffuser 180, which is arranged to overlap the viewing angle control film 100. In the embodiment, the anisotropic diffuser 180 may be arranged between the electrically controlled viewing angle switch 200 and the viewing angle control film 100, but is not limited thereto. In other embodiments, the anisotropic diffuser 180 may also be arranged between the viewing angle control film 100 and the backlight module BLU.

[0099] For example, the anisotropic diffuser 180 is only perpendicular to the anti-peeping direction of the display device 20 (i.e. Figure 3 The viewing angle control film 100 has scattering ability in the direction of the arrangement direction of the multiple optical microstructures MS, so while improving the sharing visual effect when the display device 20 is operated in the sharing mode, it can also avoid the deterioration of the anti-peeping effect when the display device 20 is operated in the anti-peeping mode.

[0100] In summary, in the viewing angle control film of one embodiment of the present invention, each of the plurality of first optical microstructures has a refractive surface on a side away from the geometric center of the setting range thereof, and the first refractive angles between the refractive surfaces of each of the first optical microstructures and the surface of the light-transmitting substrate are asymmetrically distributed relative to the geometric center. Through such a configuration, light can be directed to a specific light receiving position after passing through different positions of the viewing angle control film, thereby improving the uniformity of the overall light output brightness at the specific position. Therefore, the display screen of the display device provided with the viewing angle control film at a specific viewing position can have better brightness uniformity.

Claims

1. A viewing angle control film, characterized in that: The viewing angle control film comprises a light-transmitting substrate and a plurality of first optical microstructures, wherein: The multiple first optical microstructures are arranged on the surface of the transparent substrate, the arrangement range of the multiple first optical microstructures has a geometric center, each of the multiple first optical microstructures has a first refractive surface that deviates from the geometric center, and the angles of the first refractive angles between the first refractive surfaces of each of the multiple first optical microstructures and the surface of the transparent substrate are asymmetrically distributed relative to the geometric center.

2. The viewing angle control film according to claim 1, characterized in that: The first refraction angle between the first refraction surface of each of the plurality of first optical microstructures and the surface of the light-transmitting substrate gradually decreases as approaching the geometric center.

3. The viewing angle control film according to claim 1, characterized in that: The plurality of first optical microstructures include two first optical microstructures whose distribution ranges are symmetrically arranged relative to the geometric center, and the first refraction angles between the first refraction surfaces of the two first optical microstructures and the surface of the transparent substrate are different.

4. The viewing angle control film according to claim 1, characterized in that: The plurality of first optical microstructures include two first optical microstructures respectively arranged on opposite sides of the geometric center and farthest from the geometric center, and the first refraction angles between the first refraction surfaces of the two first optical microstructures and the surface of the transparent substrate are different.

5. The viewing angle control film according to claim 1, characterized in that: Each of the plurality of first optical microstructures further has a structural surface facing the geometric center, and a first structural angle between the structural surface and the surface of the light-transmitting substrate is greater than or equal to the first refraction angle.

6. The viewing angle control film according to claim 5, characterized in that: The angle of the first structural angle between the structural surface of each of the plurality of first optical microstructures and the surface of the light-transmitting substrate gradually decreases as approaching the geometric center.

7. The viewing angle control film according to claim 1, characterized in that: The asymmetric distribution of the first refraction angle has a minimum value at a position, and the angle of the first refraction angle between the first refraction surface of each of the plurality of first optical microstructures and the surface of the transparent substrate gradually decreases as approaching the position, and the position does not overlap with the geometric center.

8. The viewing angle control film according to claim 1, characterized in that: The viewing angle control film further comprises a plurality of second optical microstructures, wherein: The plurality of second optical microstructures are arranged on the surface of the light-transmitting substrate, and the arrangement range of the plurality of second optical microstructures overlaps with the arrangement range of the plurality of first optical microstructures, wherein the extension direction of the plurality of first optical microstructures intersects with the extension direction of the plurality of second optical microstructures.

9. The viewing angle control film according to claim 8, characterized in that: Each of the plurality of second optical microstructures has a second refractive surface away from the geometric center, and a second refractive angle between the second refractive surface of each of the plurality of second optical microstructures and the surface of the transparent substrate is symmetrically or asymmetrically distributed relative to the geometric center.

10. The viewing angle control film according to claim 1, characterized in that: The plurality of first optical microstructures are arranged around the geometric center.

11. The viewing angle control film according to claim 1, characterized in that: An optical auxiliary layer is disposed on a side surface of the light-transmitting substrate away from the plurality of first optical microstructures.

12. A display device, characterized in that: The display device comprises a viewing angle control film and a display panel, wherein: The viewing angle control film comprises a light-transmitting substrate and a plurality of first optical microstructures, wherein: The plurality of first optical microstructures are arranged on the surface of the light-transmitting substrate, the arrangement range of the plurality of first optical microstructures has a geometric center, each of the plurality of first optical microstructures has a first refractive surface away from the geometric center, and first refractive angles between the first refractive surfaces of each of the plurality of first optical microstructures and the surface of the light-transmitting substrate are asymmetrically distributed relative to the geometric center; and The display panel is arranged on one side of the viewing angle control film.

13. The display device according to claim 12, characterized in that: The display device also includes an electrically controlled viewing angle switcher, wherein: The electrically controlled viewing angle switcher overlaps the viewing angle control film and the display panel.

14. The display device according to claim 12, characterized in that: The display device further comprises an anisotropic diffuser, wherein: The anisotropic diffuser overlaps the viewing angle control film.

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