CN113219685A

CN113219685A - Backlight module and visual angle adjusting method of display

Info

Publication number: CN113219685A
Application number: CN202010080519.0A
Authority: CN
Inventors: 张嘉尹; 陈长趯; 张智强
Original assignee: Radiant Opto Electronics Suzhou Co Ltd
Current assignee: Radiant Opto Electronics Suzhou Co Ltd
Priority date: 2020-02-05
Filing date: 2020-02-05
Publication date: 2021-08-06

Abstract

The invention provides a backlight module and a method for adjusting a visual angle of a display. The backlight module comprises a first grating layer, a first backlight unit, a second grating layer and a second backlight unit. The first grating layer comprises a plurality of first light-transmitting parts, and each first light-transmitting part extends along a first direction. The first backlight unit comprises a first light guide plate and a first light source, the first light guide plate is arranged below the first grating layer and comprises a first side edge and a second side edge, the first side edge is connected with the second side edge, the length direction of the first side edge is substantially parallel to the first direction, and the first light source is arranged on the first side edge or the second side edge. The second grating layer is arranged below the first backlight unit and comprises a plurality of second light-transmitting parts, each second light-transmitting part extends along a second direction, and the second direction is substantially vertical to the first direction. The second backlight unit is arranged below the second grating layer.

Description

Backlight module and visual angle adjusting method of display

Technical Field

The present invention relates to a backlight module and a method for adjusting a viewing angle of a display, and more particularly, to a backlight module capable of switching a viewing angle and a method for adjusting a viewing angle of a display including the backlight module.

Background

With the development of technology, electronic devices equipped with screens, such as mobile phones, tablet computers, notebook computers, car monitors, and the like, have become indispensable articles in modern life. However, when such an electronic device is used in a place where there is another person, privacy of the person may be peeped or light shadow given from a screen may interfere with another person.

In order to solve the above problems, some manufacturers provide a polymer film with a peep-proof function, and when the polymer film is adhered to a screen, a user needs to be within a specific visual field range to see the screen, so as to provide the peep-proof function. However, the user needs to purchase a separate polymer film and stick the film to itself, which inevitably increases the cost and inconvenience of operation.

In addition, another display for vehicle is provided, in which a grating layer is added to the backlight module to block the light with large front and rear viewing angles, so as to prevent the light from the screen from projecting to the windshield and interfering the driver's view, however, the driver can still directly see the content of the screen, which may cause the driver to be distracted and is not good for protecting the privacy of the user of the display for vehicle.

Disclosure of Invention

Therefore, an object of the present invention is to provide a backlight module and a method for adjusting a viewing angle of a display, so as to solve the above-mentioned problems.

A first embodiment according to a first aspect of the present invention provides a backlight module, which includes a first grating layer, a first backlight unit, a second grating layer and a second backlight unit. The first grating layer comprises a plurality of first light-transmitting parts, and each first light-transmitting part extends along a first direction. The first backlight unit comprises a first light guide plate and a first light source, the first light guide plate is arranged below the first grating layer, the first light guide plate comprises a first side edge and a second side edge, the first side edge is connected with the second side edge, the length direction of the first side edge is substantially parallel to the first direction, and the length direction of the second side edge is substantially perpendicular to the first direction. The first light source is arranged on the first side edge or the second side edge of the first light guide plate and used for providing first light rays to pass through the first grating layer. The second grating layer is arranged below the first backlight unit and comprises a plurality of second light-transmitting parts, each second light-transmitting part extends along a second direction, and the second direction is substantially vertical to the first direction. The second backlight unit is arranged below the second grating layer and used for providing second light rays to pass through the second grating layer.

A second embodiment according to the first aspect of the present invention provides a backlight module, which includes a first grating layer, a second grating layer, a first backlight unit and a second backlight unit. The first grating layer comprises a plurality of first light-transmitting parts, and each first light-transmitting part extends along a first direction. The second grating layer is arranged below the first grating layer and comprises a plurality of second light-transmitting parts, each second light-transmitting part extends along a second direction, and the second direction is substantially vertical to the first direction. The first backlight unit includes a first light guide plate and a first light source. The first light guide plate is arranged between the first grating layer and the second grating layer. The first light source extends along a direction parallel to the first direction and perpendicular to the second direction and is located on one side edge of the first light guide plate, and the first light source is used for providing first light rays which are projected towards the first grating layer through the first light guide plate and are transmitted out through the at least first light transmission part. The second backlight unit is arranged below the second grating layer and used for providing second light rays to pass through the second grating layer.

A third embodiment according to the first aspect of the present invention provides a backlight module, which includes a first grating layer, a second grating layer, a first backlight unit and a second backlight unit. The first grating layer comprises a plurality of first light-transmitting parts, and each first light-transmitting part extends along a first direction. The second grating layer is arranged below the first grating layer and comprises a plurality of second light-transmitting parts, each second light-transmitting part extends along a second direction, and the second direction is substantially vertical to the first direction. The first backlight unit comprises a first light guide plate and a first light source, and the first light guide plate is arranged between the first grating layer and the second grating layer. The first light source extends along a direction perpendicular to the first direction and parallel to the second direction and is located on one side edge of the first light guide plate, and the first light source is used for providing first light rays which are projected towards the first grating layer through the first light guide plate and are transmitted out through the at least first light transmission part. The second backlight unit is arranged below the second grating layer and used for providing second light rays to pass through the second grating layer.

According to a second aspect of the present invention, a method for adjusting a viewing angle of a display is provided, the display includes a display panel and a backlight module as described in the first or second aspect of the present invention, and the method for adjusting a viewing angle of a display selectively performs a first wide viewing angle sharing mode and a privacy mode. The method for adjusting the viewing angle of the display includes controlling the first backlight unit to make the first light provided by the first light source enter the first light guide plate through a side edge of the first light guide plate parallel to the first direction and the second backlight unit is controlled not to provide the second light when the first wide viewing angle sharing mode is executed for the display panel, and controlling the first backlight unit not to provide the first light and the second backlight unit not to provide the second light when the privacy mode is executed for the display panel.

A second embodiment according to a second aspect of the present invention provides a method for adjusting a viewing angle of a display, the display including a display panel and a backlight module as described in the first or third embodiment of the first aspect, the method for adjusting a viewing angle of a display selectively performing a first off-angle sharing mode and a privacy mode, the method for adjusting a viewing angle of a display including controlling a first backlight unit such that first light provided by a first light source enters a first light guide plate through a side of the first light guide plate parallel to a second direction and a second backlight unit is controlled such that second light is not provided when the first off-angle sharing mode is performed for the display panel. When the privacy mode is performed for the display panel, the first backlight unit is controlled not to provide the first light, and the second backlight unit is controlled to provide the second light.

Compared with the prior art, the invention provides the backlight module with the switchable viewing angle, which can be applied to the display and can provide the sharing mode and the privacy mode for the display, thereby being beneficial to protecting the privacy of a user and avoiding interfering with other people.

Drawings

Fig. 1 is an exploded view of a backlight module according to an embodiment of the present invention.

Fig. 2 is an exploded view of a backlight module according to another embodiment of the present invention.

Fig. 3 is a schematic diagram of an optical path of light passing through the second grating layer according to an embodiment of the present invention.

Fig. 4 is a light field distribution diagram of the backlight module of fig. 1 in a first wide view angle sharing mode.

Fig. 5 is a light field distribution diagram of the backlight module of fig. 1 in the privacy mode.

FIG. 6 is a light field distribution diagram of the backlight module of FIG. 2 in a first off-angle sharing mode.

Fig. 7 is a flowchart illustrating a method for adjusting a viewing angle of a display according to an embodiment of the invention.

FIG. 8 is a flowchart illustrating a method for adjusting a viewing angle of a display according to another embodiment of the present invention.

Fig. 9 is a flowchart illustrating a method for adjusting a viewing angle of a display according to another embodiment of the present invention.

Fig. 10 is a flowchart illustrating a method for adjusting a viewing angle of a display according to another embodiment of the present invention.

Detailed Description

The foregoing and other technical matters, features and effects of the present invention will be apparent from the following detailed description of preferred embodiments, which is to be read in connection with the accompanying drawings. The following examples refer to directional terms such as: up, down, left, right, front or rear, etc., are simply directions with reference to the drawings. Accordingly, the directional terminology is used for purposes of illustration and is in no way limiting. In addition, in the following embodiments, the same or similar components will be given the same or similar reference numerals.

In the present invention, the two components are substantially parallel to each other means that an included angle is formed between the two components, and the included angle is 0 degree ± 10 degrees, preferably 0 degree ± 5 degrees, more preferably 0 degree ± 3 degrees, or the included angle is 180 degrees ± 10 degrees, preferably 180 degrees ± 5 degrees, more preferably 180 degrees ± 3 degrees. In the present invention, the two components are substantially perpendicular to each other, which means that an included angle is formed between the two components, and the included angle is 90 degrees ± 10 degrees, preferably 90 degrees ± 5 degrees, and more preferably 90 degrees ± 3 degrees.

In the present invention, the backlight module can be used to provide a light source for a Liquid Crystal Display (LCD) panel, each component in the backlight module includes a bottom surface and a top surface, the definition of the bottom surface and the top surface is based on the LCD panel, and each component uses a surface far away from the LCD panel as the bottom surface and a surface facing the LCD panel as the top surface.

Referring to fig. 1, an exploded view of a backlight module 10 according to an embodiment of the present invention is shown. The backlight module 10 includes a first grating layer 100, a first backlight unit 200, a second grating layer 300, and a second backlight unit 400.

The first grating layer 100 includes a plurality of first transparent portions 110 and a plurality of first light-shielding portions 120, the first transparent portions 110 and the first light-shielding portions 120 are arranged in a staggered manner, and the first transparent portions 110 and the first light-shielding portions 120 extend along a first direction D1.

The first backlight unit 200 includes a first light guide plate 220 and a first light source 230, and optionally further includes other optical films, and here, a first Brightness Enhancement Film (Brightness Enhancement Film)210 is exemplified.

The first light guide plate 220 is disposed below the first grating layer 100 and between the first grating layer 100 and the second grating layer 300. The first light guide plate 220 includes a first side 221 and a second side 222, the first side 221 is connected to the second side 222, a length direction L1 of the first side 221 is substantially parallel to the first direction D1, a length direction L2 of the second side 222 is substantially perpendicular to the first direction D1 and substantially parallel to the second direction D2, and a first direction D1 is substantially perpendicular to the second direction D2.

The first light source 230 extends along a direction parallel to the first direction D1 and perpendicular to the second direction D2 and is located at a side Edge of the first light guide plate 220, wherein the first light source 230 is disposed at the first side Edge 221 of the first light guide plate 220, and based on the arrangement of the first light source 230, the first backlight unit 200 belongs to an Edge Type (Edge Type) backlight unit. The first light source 230 is configured to provide a first light (not shown) through the first grating layer 100, and specifically, the first light source 230 is configured to provide the first light to be projected toward the first grating layer 100 through the first light guide plate 220 and to be transmitted out through the at least one first light-transmitting portion 110.

The first brightness enhancement film 210 is disposed between the first grating layer 100 and the first light guide plate 220, the first brightness enhancement film 210 includes a surface 211 and a plurality of first light collecting structures 212, the first light collecting structures 212 are formed on the surface 211, and an extending direction E1 of each of the first light collecting structures 212 is substantially parallel to the first direction D1. The first light-gathering structure 212 may be a protruding stripe-shaped microstructure and faces the first grating layer 100.

The second grating layer 300 is disposed below the first grating layer 100 and the first backlight unit 200, the second grating layer 300 includes a plurality of second light-transmitting portions 310 and a plurality of second light-shielding portions 320, the second light-transmitting portions 310 and the second light-shielding portions 320 are arranged in a staggered manner, and the second light-transmitting portions 310 and the second light-shielding portions 320 extend along a second direction D2.

The second backlight unit 400 is disposed below the second grating layer 300, and the second backlight unit 400 is used for providing a second light beam through the second grating layer 300. The second backlight unit 400 may include an optical Sheet 430 and a second light source 440, and optionally further include other optical films, exemplified by further including a second brightness enhancement film 410, a diffusion Sheet 420 and a Reflective Sheet 450.

The optical plate 430 may include a bottom surface 432 and at least one side 431, where the bottom surface 432 is connected to the side 431, and the second light source 440 is disposed on the side 431, that is, the second backlight unit 400 is a side-in Type backlight unit, and in other embodiments, the second light source 440 may be disposed on the bottom surface 432, such that the second backlight unit 400 is configured as a Direct Type backlight unit.

The second brightness enhancement film 410 is disposed between the second grating layer 300 and the optical plate 430, the second brightness enhancement film 410 may include a surface 411 and a plurality of second light-condensing structures 412, the second light-condensing structures 412 are formed on the surface 411, and an extending direction E2 of each of the second light-condensing structures 412 is substantially parallel to the second direction D2. The second light-condensing structure 412 may be a protruding stripe-shaped microstructure and faces the second grating layer 300. The extending direction E1 of the first light concentrating structure 212 is substantially perpendicular to the extending direction E2 of the second light concentrating structure 412.

More specifically, the first grating layer 100 and the second grating layer 300 may be louver ink films, and the first grating layer 100 and the second grating layer 300 may use a transparent film as a substrate, and print an opaque material on one surface of the transparent film to form the first light shielding portion 120 and the second light shielding portion 320. The first Light source 230 and the second Light source 440 can be, but not limited to, Cold Cathode Fluorescent Lamp (CCFL) or Light Emitting Diode (LED) Light bars, such as LED Light bars. The backlight module 10 can improve the optical properties by selectively adding other optical films. For example, the first brightness enhancement film 210 and the second brightness enhancement film 410 can increase the directivity of the emergent light to improve the front brightness, in the embodiment, the first brightness enhancement film 210 and the second brightness enhancement film 410 are Prism sheets (Prism sheets), and the cross sections of the first light collecting structures 212 and the second light collecting structures 412 are triangular, but the invention is not limited thereto, and in other embodiments, the cross sections of the first light collecting structures 212 and the second light collecting structures 412 can be configured in other shapes such as circular arc. The uniformity of the light can be improved by the diffusion sheet 420. By the reflection sheet 450, the second light beams of the second light source 440 leaking from the bottom surface 432 of the optical plate 430 can be reflected back to the optical plate 430, so that the utilization efficiency of the second light source 440 can be improved. The type and configuration of other optical films can be flexibly adjusted according to actual requirements, and the present invention is not limited in implementation.

Fig. 3 is a schematic diagram of an optical path of a light ray L passing through the second grating layer 300 according to an embodiment of the present invention. In fig. 3, the second light transmission portion 310 extends along the second direction D2, so that the light-emitting angle a of the light L in the first direction D1 (left and right directions) can be reduced. Similarly, the first light-transmitting portion 110 of the first grating layer 100 extends along the first direction D1, and the light-emitting angle of the light ray in the second direction D2 (front and back directions) can be reduced.

Fig. 4 is a light field distribution diagram of the backlight module 10 of fig. 1 in the first wide view angle sharing mode. As shown in fig. 4, the first light source 230 is turned on, and the second light source 440 is turned off, so that only the light emitting angle in the second direction D2 is reduced, and the backlight module 10 can provide the first wide view angle sharing mode. When the backlight module 10 is applied to a display for a vehicle, the light and shadow emitted by the screen can be prevented from projecting to the windshield and interfering the sight of the driver. In addition, when the first light source 230 is in the on state and the second light source 440 is in the on state, the backlight module 10 can provide the second wide view angle sharing mode, and compared to the first wide view angle sharing mode, the brightness of the backlight module 10 can be improved because the second light source 440 is in the on state.

Fig. 5 is a light field distribution diagram of the backlight module 10 of fig. 1 in the privacy mode. In fig. 5, first light source 230 is in an off state and second light source 440 is in an on state. In detail, the light field distribution graph 510 is a measurement result of the second light beam after passing through the second grating layer 300, the light field distribution graph 520 is a measurement result of the second light beam after passing through the first brightness enhancement film 210, and the light field distribution graph 530 is a measurement result of the second light beam after passing through the first grating layer 100. As shown in fig. 5, when the second light continuously passes through the second grating layer 300 and the first grating layer 100, the light emitting angles of the first direction D1 and the second direction D2 can be sequentially reduced, so that the backlight module 10 can provide the privacy mode. When the backlight module 10 is applied to a vehicle display located in a passenger seat, the content of the screen can be viewed only by a passenger sitting in the passenger seat, thereby preventing the driver from being distracted and being beneficial to protecting the privacy of the passenger.

When the embodiment of the backlight module 10 shown in fig. 1 according to the present invention is applied to a display, a flow chart of the method 700 for adjusting the viewing angle of the display is shown in fig. 7. The display may include a display panel (not shown), which may be an LCD panel, and a backlight module 10, and may be mounted on an electronic device, such as a notebook computer, a tablet computer, a mobile phone, etc.

The method 700 for adjusting the viewing angle of a display includes the following steps. Step 710 begins, step 720 is that the user selects to execute the first wide view angle sharing mode or the privacy mode, and when the user selects to execute the first wide view angle sharing mode for the display panel, step 730 is performed, the first backlight unit 200 is controlled such that the first light provided by the first light source 230 enters the first light guide plate 220 through a side (i.e., the first side 221) of the first light guide plate 220 parallel to the first direction D1, and the second backlight unit 400 is controlled such that the second light is not provided. When the user selects to perform the privacy mode for the display panel, step 740 is performed, the first backlight unit 200 is controlled not to provide the first light, and the second backlight unit 400 is controlled to provide the second light. Thereafter, step 750 is performed, which ends. Therefore, the method 700 for adjusting the viewing angle of the display according to the present invention selectively executes the first wide viewing angle sharing mode and the privacy mode.

Referring to fig. 8, a flowchart illustrating a method 800 for adjusting a viewing angle of a display according to another embodiment of the invention is shown. Compared to the viewing angle adjusting method 700 of the display, the viewing angle adjusting method 800 of the display has more selectable second wide viewing angle sharing mode, step 820 is that the user selects to execute the first wide viewing angle sharing mode, the second wide viewing angle sharing mode or the privacy mode, when the user selects to execute the second wide viewing angle sharing mode for the display panel, step 835 is performed, the first backlight unit 200 is controlled to make the first light provided by the first light source 230 enter the first light guide plate 220 through the side edge (i.e. the first side edge 221) of the first light guide plate 220 parallel to the first direction D1, and the second backlight unit 400 is controlled to provide the second light. Reference may be made to steps 710, 730,740, and 750 of FIG. 7, respectively, with respect to

steps

810, 830, 840, and 850 of FIG. 8. Compared to the first wide view angle sharing mode, the second wide view angle sharing mode adds the second light provided by the second backlight unit 400, so as to further improve the brightness.

Fig. 2 is an exploded view of a backlight module 10a according to another embodiment of the present invention. The backlight module 10a includes a first grating layer 100, a first backlight unit 200a, a second grating layer 300, and a second backlight unit 400. The

backlight modules

10a and 10 are different in the position of the first light source 230, in fig. 2, the first light source 230 extends along a direction perpendicular to the first direction D1 and parallel to the second direction D2 and is located at a side of the first light guide plate 220, that is, the first light source 230 is located at the second side 222 of the first light guide plate 220. Thereby, the light emitting direction of the first light source 230 is toward the left side of the first direction D1.

Fig. 6 is a light field distribution diagram of the backlight module 10a of fig. 2 in the first off-angle sharing mode. In fig. 6, the first light source 230 is turned on and the second light source 440 is turned off, so that only the light emitting angle of the second direction D2 is reduced and the light emitting direction is toward the left side of the first direction D1, so that the backlight module 10a can provide the first sharing mode of the off-viewing angles. When the backlight module 10a is applied to a vehicle display, it is possible to prevent light and shadow emitted from a display screen from projecting to a windshield and interfering with the line of sight of a driver, and to prevent reflection and reflection of light from a right window from interfering with the screen of the vehicle.

When the first light source 230 and the second light source 440 are both turned on, the backlight module 10a can provide a second biased viewing angle sharing mode, and compared to the first biased viewing angle sharing mode, the brightness of the backlight module 10a can be improved because the second light source 440 is turned on.

When the first light source 230 is in the off state and the second light source 440 is in the on state, the backlight module 10a can provide the privacy mode, based on the difference between the backlight module 10a and the backlight module 10 only in the configuration position of the first light source 230, since the first light source 230 is in the off state in the privacy mode, the light field profile of the backlight module 10a in the privacy mode is the same as that of the backlight module 10, and refer to fig. 5.

When the backlight module 10a shown in fig. 2 according to another embodiment of the present invention is applied to a display, a flowchart of a method 900 for adjusting a viewing angle of the display is shown in fig. 9. The display may include a display panel (not shown) and a backlight module 10a, and details of the display can be found in relation to the description of fig. 7.

The method 900 for adjusting the viewing angle of the display includes the following steps. Step 910 begins, step 920 is that the user selects to execute the first partial view sharing mode or the privacy mode, and when the user selects to execute the first partial view sharing mode for the display panel, step 930 is performed in which the first backlight unit 200a is controlled such that the first light provided by the first light source 230 enters the first light guide plate 220 through a side edge (i.e., the second side edge 222) of the first light guide plate 220 parallel to the second direction D2, and the second backlight unit 400 is controlled not to provide the second light. When the user selects to perform the privacy mode for the display panel, step 940 is performed, the first backlight unit 200a is controlled not to provide the first light, and the second backlight unit 400 is controlled to provide the second light. Thereafter, step 950 is performed, which ends. Therefore, the method 900 for adjusting the viewing angle of the display according to the present invention can selectively execute the first partial viewing angle sharing mode and the privacy mode.

Fig. 10 is a flowchart illustrating a method 1000 for adjusting a viewing angle of a display according to another embodiment of the invention. Compared to the method 900 for adjusting the viewing angle of the display, the method 1000 for adjusting the viewing angle of the display has a second off-viewing angle sharing mode selectable, in step 1020, the user selects to execute the first off-viewing angle sharing mode, the second off-viewing angle sharing mode or the privacy mode, and when the user selects to execute the second off-viewing angle sharing mode to the display panel, in step 1035, the first backlight unit 200a is controlled such that the first light rays provided by the first light source 230 enter the first light guide plate 220 through the side edge (i.e., the second side edge 222) of the first light guide plate 220 parallel to the second direction D2, and the second backlight unit 400 is controlled to provide the second light rays. Reference may be made to steps 910, 930,940 and 950 of fig. 9, respectively, with respect to

steps

1010, 1030, 1040 and 1050 of fig. 10. Compared to the first polarization mode, the second polarization mode adds the second light provided by the second backlight unit 400, thereby further increasing the brightness.

Referring to fig. 2, in other embodiments, when the vehicle is configured as a right-driving system, the first light source 230 may be disposed at the other second side 223 of the first light guide plate 220, so that the light emitting direction of the first light source 230 is toward the right side of the first direction D1, and the reflection of the left window can be prevented from interfering with the image of the display screen, that is, the backlight module of other embodiments can provide the third off-angle sharing mode. Under this configuration, when the first light source 230 and the second light source 440 are both in the on state, the backlight module can provide a fourth partial viewing angle sharing mode. In other embodiments, the first light source 230 may be disposed on both the first side 221 and the second side 222,223 of the first light guide plate 220, so that the backlight module can selectively provide the first and the second wide view angle sharing modes, the first to the fourth partial view angle sharing modes, and the privacy mode, thereby improving the versatility of the backlight module.

Compared with the prior art, the invention provides the backlight module with the switchable viewing angle, which can be applied to the display and can provide the sharing mode and the privacy mode for the display, thereby being beneficial to protecting the privacy of a user and avoiding interfering with other people. When the display is applied to the automobile display, the light and shadow of the display screen can be prevented from projecting to the windshield to interfere the sight of a driver in the sharing mode, the content of the display screen can be prevented from being seen by the driver in the privacy mode, the distraction of the driver can be avoided, and the privacy of passengers can be protected. The backlight module provided by the invention can further make the light-emitting angle in the sharing mode deviate to the right side or the left side by adjusting the position of the first light source, thereby preventing the light shadow of the left side or the right side window from interfering the picture of the screen and being beneficial to further improving the image quality of the display.

The above-mentioned embodiments are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the claims of the present invention should be covered by the claims of the present invention.

Description of the symbols

10,10a backlight module

100 first grating layer

110 first light transmission part

120 first light shielding part

200,200a first backlight unit

210 first brightness enhancement film

211,411 surface

212 first light concentrating structure

220 first light guide plate

221 first side edge

222,223 second side edge

230 first light source

300 second grating layer

310 second light transmission part

320 second light shielding part

400 second backlight unit

410 second brightness enhancement film

412 second light-concentrating structure

420 diffusion sheet

430 optical plate

Side 431

432 bottom surface

440 second light source

450 reflector plate

510,520,530 light field Profile

700,800,900,1000 visual angle adjusting method for display

710,720,730,740,750 step

810,820,830,835,840,850 step

910,920,930,940,550 step

1010,1020,1030,1035,1040,1050 step

Angle of A light output

D1 first direction

D2 second direction

E1, E2 extension direction

L1, L2 in the longitudinal direction

L ray.

Claims

1. A backlight module, comprising:

the first grating layer comprises a plurality of first light-transmitting parts, and each first light-transmitting part extends along a first direction;

a first backlight unit including:

the first light guide plate is arranged below the first grating layer and comprises a first side edge and a second side edge, the first side edge is connected with the second side edge, the length direction of the first side edge is substantially parallel to the first direction, and the length direction of the second side edge is substantially perpendicular to the first direction; and

the first light source is arranged at the first side edge or the second side edge of the first light guide plate and used for providing first light rays to pass through the first grating layer;

a second grating layer disposed below the first backlight unit, the second grating layer including a plurality of second light-transmitting portions, each of the second light-transmitting portions extending in a second direction, the second direction being substantially perpendicular to the first direction; and

and the second backlight unit is arranged below the second grating layer and is used for providing second light rays to pass through the second grating layer.

2. A backlight module, comprising:

the second grating layer is arranged below the first grating layer and comprises a plurality of second light-transmitting parts, each second light-transmitting part extends along a second direction, and the second direction is substantially vertical to the first direction;

a first backlight unit including:

the first light guide plate is arranged between the first grating layer and the second grating layer; and

the first light source extends along a direction parallel to the first direction and perpendicular to the second direction and is positioned on the side edge of the first light guide plate, and the first light source is used for providing first light rays which are projected towards the first grating layer through the first light guide plate and are transmitted out by at least one first light-transmitting part; and

3. A backlight module, comprising:

a first backlight unit including:

the first light source extends along a direction which is perpendicular to the first direction and parallel to the second direction and is positioned on the side edge of the first light guide plate, and the first light source is used for providing first light rays which are projected towards the first grating layer through the first light guide plate and are transmitted out by at least one first light-transmitting part; and

4. The backlight module of any of claims 1-3, wherein the first and second grating layers are each a louver ink film.

5. The backlight module according to any one of claims 1-3, wherein the first backlight unit further comprises:

the first light guide plate is arranged on the first light guide plate, the first light guide plate is arranged on the second light guide plate, and the first light guide plate is arranged on the first light guide plate.

6. The backlight module as claimed in claim 5, wherein the first light collecting structure of the first brightness enhancement film is a protruding stripe-shaped microstructure and faces the first grating layer.

7. The backlight module according to any one of claims 1-3, wherein the second backlight unit comprises:

the optical plate comprises a bottom surface and at least one side edge, wherein the bottom surface is connected with the side edge; and

the second light source is arranged on the bottom surface or the side edge of the optical plate and used for providing second light rays.

8. The backlight module of claim 7, wherein the second backlight unit further comprises:

the second brightness enhancement film is arranged between the second grating layer and the optical plate and comprises a surface and a plurality of second light condensation structures, the second light condensation structures are formed on the surface, and the extending direction of each second light condensation structure is substantially parallel to the second direction.

9. The backlight module of claim 8, wherein the second light concentrating structure of the second brightness enhancement film is a protruding stripe microstructure and faces the second grating layer.

10. The backlight module as claimed in claim 7, wherein the first backlight unit further comprises a first brightness enhancement film disposed between the first grating layer and the first light guide plate, the second backlight unit further comprises a second brightness enhancement film disposed between the second grating layer and the optical plate, the first brightness enhancement film comprises a plurality of first light collecting structures, the second brightness enhancement film comprises a plurality of second light collecting structures, and an extending direction of each of the first light collecting structures is substantially perpendicular to an extending direction of each of the second light collecting structures.

11. A method for adjusting a viewing angle of a display, the display comprising a display panel and the backlight module according to claim 1 or 2, the method for adjusting a viewing angle of a display selectively performing a first wide viewing angle sharing mode and a privacy mode, the method comprising:

when the first wide view angle sharing mode is executed for the display panel, the first backlight unit is controlled so that the first light provided by the first light source enters the first light guide plate through a side edge of the first light guide plate parallel to the first direction, and the second backlight unit is controlled not to provide the second light; and

when the privacy mode is performed for the display panel, the first backlight unit is controlled not to provide the first light, and the second backlight unit is controlled to provide the second light.

12. The method of claim 11, further comprising selectively performing a second wide viewing angle sharing mode, wherein when the second wide viewing angle sharing mode is performed for the display panel, the first backlight unit is controlled such that the first light provided by the first light source enters the first light guide plate through a side edge of the first light guide plate parallel to the first direction, and the second backlight unit is controlled such that the second light is provided.

13. A method for adjusting a viewing angle of a display, the display comprising a display panel and the backlight module according to claim 1 or 3, the method for adjusting a viewing angle of a display being capable of selectively performing a first off-viewing angle sharing mode and a privacy mode, the method comprising:

when the first off-angle sharing mode is performed for the display panel, the first backlight unit is controlled such that the first light provided by the first light source enters the first light guide plate through a side edge of the first light guide plate parallel to the second direction, and the second backlight unit is controlled such that the second light is not provided; and

14. The method of claim 13, further comprising optionally performing a second off-angle sharing mode, wherein when the second off-angle sharing mode is performed for the display panel, the first backlight unit is controlled such that the first light provided by the first light source enters the first light guide plate via a side edge of the first light guide plate parallel to the second direction, and the second backlight unit is controlled to provide the second light.