Backlight module and display device

Abstract

The present invention discloses a backlight module and a display device, wherein the backlight module comprises a light emitting unit, wherein the light propagates in a direction perpendicular to the light emitting surface of the backlight module after passing through an optical film, and further comprises a dimming layer located on the side of the optical film close to the light emitting surface of the backlight module, wherein the dimming layer comprises a plurality of dimming units, wherein the dimming unit comprises a first surface and a second surface, wherein the first surface is located on the side close to the light emitting surface of the backlight module and is a plane, and the second surface comprises at least a first sub-surface and a second sub-surface, wherein the plane where the first sub-surface is located in the second direction intersects with the plane where the first surface is located, and the plane where the second sub-surface is located in the third direction intersects with the plane where the first surface is located, and both the first sub-surface and the second sub-surface are inclined toward the side away from the light emitting surface of the backlight module; and the first direction, the second direction and the third direction all intersect. The present invention reduces the large-angle luminous flux of the backlight module, increases the luminous flux within a small viewing angle, increases the contrast within a small viewing angle, and improves the display performance.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and more specifically, to a backlight module and a display device. Background Art

[0002] The backlight module is one of the key components of the liquid crystal display panel (LCD Panel). Since liquid crystal itself does not have the property of emitting light, a light source must be added to the back of the LCD display panel to achieve a full color display effect. The function of the backlight module is to provide sufficient brightness and evenly distributed planar light source so that the LCD display panel can display images normally.

[0003] Backlight modules can be divided into side-entry backlight modules and direct-type backlight modules. Direct-type backlight modules use direct-type backlight sources. Direct-type backlight sources require that the light source be evenly distributed on the entire surface. A diffuser with a relatively high hardness is required above the light source to blur the light source and support the optical film above. Side-entry backlight modules usually have side-entry backlight sources on the side of the light guide plate. The light emitted by the side-entry backlight source enters the light guide plate and is diffused by the dots or reflective structures set on the light guide plate, destroying the internal propagation caused by total reflection, so that the light is evenly emitted from the light-emitting surface of the light guide plate, realizing the transformation from a point light source to a surface light source, in order to improve the backlight module. Whether it is direct-down or side-entry, the structure of the lower diffuser, prism sheet, and upper diffuser sheet needs to be designed above the backlight source. The function of the lower diffuser is to concentrate the light emitted from the light guide plate and evenly project it onto the prism sheet. The function of the prism sheet is to use the law of total reflection and refraction to concentrate the scattered light within a certain angle range and emit it, thereby improving the brightness within this angle range. The function of the upper diffuser is to atomize the light emitted by the prism sheet and transmit the light evenly. At the same time, the upper diffuser can protect the prism sheet. In the prior art, the angle of light deflection by the prism sheet is too large, resulting in more light at a large viewing angle and less light at a small viewing angle, so that the contrast of the small viewing angle area cannot meet the requirements.

[0004] Therefore, there is an urgent need to provide a backlight module and a display device that can improve the contrast in a small viewing angle area. Summary of the invention

[0005] In view of this, the present invention provides a backlight module and a display device to improve the contrast ratio in a small viewing angle area.

[0006] In one aspect, the present invention provides a backlight module, comprising:

[0007] Light emitting unit;

[0008] An optical film, wherein the light provided by the light-emitting unit propagates along a first direction after passing through the optical film, and the first direction is a direction perpendicular to the light-emitting surface of the backlight module;

[0009] A dimming layer located on a side of the optical film close to the light-emitting surface of the backlight module, the dimming layer comprising a plurality of dimming units, the dimming units comprising a first surface and a second surface arranged opposite to each other along a first direction, the first surface being located on a side of the second surface close to the light-emitting surface of the backlight module, the second surface at least comprising a first sub-surface and a second sub-surface, the first surface being a plane, along the second direction, the plane where the first sub-surface is located intersects with the plane where the first surface is located, and the first sub-surface is inclined toward a side away from the light-emitting surface of the backlight module, and along a third direction, the plane where the second sub-surface is located intersects with the plane where the first surface is located, and the second sub-surface is inclined toward a side away from the light-emitting surface of the backlight module;

[0010] The first direction, the second direction and the third direction all intersect, and the second direction and the third direction are both parallel to the light emitting surface of the backlight module.

[0011] On the other hand, the present invention provides a display device, comprising the above-mentioned backlight module, and a display panel located on a light emitting surface side of the backlight module.

[0012] Compared with the prior art, the backlight module and display device provided by the present invention achieve at least the following beneficial effects:

[0013] In the backlight module of the present invention, the light emitted by the light-emitting unit propagates in a direction perpendicular to the light-emitting surface of the backlight module after passing through the optical film, and then is deflected by the dimming layer. The dimming layer is located on the side of the optical film close to the light-emitting surface of the backlight module. The dimming layer deflects the light perpendicular to the light-emitting surface of the backlight module to a small angle. On the one hand, the dimming layer replaces the prism sheet in the related art. The prism sheet in the related art needs to be set as two layers of prism strips, one layer of prism strips extends along the second direction and is arranged in the third direction, and the other layer of prism strips extends along the third direction and is arranged in the second direction. The manufacturing process is relatively complicated. The present invention only uses one layer of dimming layer to replace the prism sheet in the related art, and the manufacturing process is simple. On the other hand, the prism sheet in the related art deflects the light at too large an angle, resulting in more light at a large viewing angle and less light at a small viewing angle, so that the contrast of the small viewing angle area cannot meet the requirements. The dimming layer in the present invention includes a plurality of dimming units. The dimming unit includes a first surface and a second surface arranged relatively opposite to each other along a first direction. The first surface is located near the second surface. On one side near the light-emitting surface of the backlight module, the second surface at least includes a first sub-surface and a second sub-surface, the first surface is a plane, along the second direction, the plane where the first sub-surface is located intersects with the plane where the first surface is located, and the first sub-surface is inclined toward the side away from the light-emitting surface of the backlight module, and along the third direction, the plane where the second sub-surface is located intersects with the plane where the first surface is located, and the second sub-surface is inclined toward the side away from the light-emitting surface of the backlight module; the first direction, the second direction and the third direction all intersect, and the second direction and the third direction are both parallel to the light-emitting surface of the backlight module, so that the light is deflected in the second direction and the third direction at the same time, so that the luminous flux in the small viewing angle area after deflection is increased, and the contrast in the small viewing angle area meets the requirements.

[0014] Of course, any product implementing the present invention does not necessarily need to achieve all of the technical effects described above at the same time.

[0015] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0017] Figure 1 It is a structural schematic diagram of a backlight module provided by the related technology;

[0018] Figure 2 It is a schematic diagram of the structure of a prism sheet in the related art;

[0019] Figure 3 yes Figure 1 Schematic diagram of the contrast contour of the backlight module;

[0020] Figure 4 It is a schematic diagram of the planar structure of a backlight module provided by the present invention;

[0021] Figure 5 yes Figure 4 A cross-section along the A-A' direction;

[0022] Figure 6 It is a structural schematic diagram of a dimming layer provided by the present invention;

[0023] Figure 7 yes Figure 6 A cross-section in the B-B' direction;

[0024] Figure 8 yes Figure 6 A cross-section in the C-C' direction;

[0025] Fig. 9 yes Figure 4 Schematic diagram of the contrast contour of the backlight module;

[0026] Fig.10 It is a structural schematic diagram of a dimming unit provided by the present invention;

[0027] Fig.11 is a schematic diagram of an orthographic projection of a dimming unit on a first cross section;

[0028] Fig.12 is a schematic diagram of an orthographic projection of the dimming unit on the second cross section;

[0029] Fig.13 is a structural schematic diagram of another dimming layer provided by the present invention;

[0030] Fig.14 is a schematic diagram of an orthographic projection of a dimming unit on a first cross section;

[0031] Fig.15 is a schematic diagram of an orthographic projection of the dimming unit on the second cross section;

[0032] Fig.16 Is adopted Fig.13 Schematic diagram of the light output contrast contour of the backlight module behind the dimming layer;

[0033] Fig.17 is a structural schematic diagram of another dimming layer provided by the present invention;

[0034] Fig.18 Is adopted Fig.17 Schematic diagram of the light output contrast contour of the backlight module behind the dimming layer;

[0035] Fig.19 This is a schematic diagram of the planar structure of another backlight module provided by the present invention;

[0036] Fig. 20 yes Fig.19 Schematic diagram of the contrast contour of the light output from the backlight module;

[0037] Fig.21 yes Fig.19 A cross-section in the D-D' direction;

[0038] Fig. 22 is a structural schematic diagram of another dimming layer provided by the present invention;

[0039] Fig.23 yes Fig. 22 A cross-section in the E-E' direction;

[0040] Fig.24 yes Fig. 22 A cross-section in the F-F' direction;

[0041] Fig.25 Is adopted Fig. 22 Schematic diagram of the contrast contour of the light emitted by the backlight module after the dimming layer;

[0042] Fig.26 A schematic diagram of a planar structure of a display device provided by the present invention;

[0043] Fig. 27 yes Fig.26 A cross-section along the G-G' direction. DETAILED DESCRIPTION

[0044] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0045] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0046] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0047] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0048] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0049] In view of the fact that the contrast ratio of the backlight module in the related art cannot meet the requirements in the small viewing angle area, the inventor has conducted the following research on the related art, referring to Figure 1 , Figure 2 and Figure 3 , Figure 1 It is a structural schematic diagram of a backlight module provided by the related technology. Figure 2 is a schematic diagram of the structure of a prism sheet in the related art, Figure 3 yes Figure 1 Schematic diagram of the backlight module's luminous contrast contours. Figure 1 The backlight module 000 in the embodiment is described by taking an edge-entry backlight module as an example. The backlight module 000 includes an edge-entry backlight source 001, a light guide plate 002 arranged opposite to the edge-entry backlight source 001, and a reflective sheet 003 located on the light guide plate 002 and away from the light exiting surface K001 of the backlight module. The light emitted by the edge-entry backlight source 001 enters the light guide plate 002, passes through the reflective sheet 003, and is reflected to the side of the light exiting surface K001 of the backlight module, and then passes through the lower diffuser 004, the prism sheet 005, and the upper diffuser 006 in sequence. 6, and deflects the light when passing through the prism sheet 005. The prism sheet 005 is usually provided with two layers. The first layer of the prism sheet has triangular prism strips 0050 extending in the row direction and arranged in the column direction, and the second layer of the prism sheet has triangular prism strips 0050 extending in the column direction and arranged in the row direction, and the vertex angles of the triangular prism strips are all toward the light-emitting surface K001 of the backlight module. When the light passes through the side wall of the triangular corner strip 0050, the light is deflected in the direction of a large angle, thereby resulting in more light at a large angle. Figure 3 , Figure 3 It is a contrast contour map of the light after being modulated by the prism sheet 005. The contrast refers to the brightness ratio of the brightest white and the darkest black when the backlight module emits light. For the backlight module, it is usually required that the contrast in the small viewing angle area A+ zone is greater than or equal to 1300. However, after the backlight module of the related art is modulated by the prism sheet 005, the light is deflected at a larger angle, and the light in the small viewing angle area is relatively small, resulting in the contrast of the small viewing angle area being less than 1300. Figure 3 The positions of the upper left and upper right corners of the small viewing angle area A+ are not within the range of the contour line of 1300 (i.e. Figure 3 In the middle pattern fill area), the contrast requirement cannot be met.

[0050] In view of this, the present invention provides a backlight module and a display device to solve the above problems. Specific embodiments of the backlight module and the display device will be described in detail below.

[0051] Reference Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Fig. 9 , Figure 4 is a schematic diagram of a planar structure of a backlight module provided by the present invention, Figure 5 yes Figure 4 A cross-section along the A-A' direction, Figure 6 is a structural schematic diagram of a dimming layer provided by the present invention, Figure 7 yes Figure 6 A cross-section along the B-B' direction, Figure 8 yes Figure 6 A cross-section view along the C-C' direction, Fig. 9 yes Figure 4 Schematic diagram of the contrast contour of the backlight module. Of course, the structure of the dimming layer 30 in this embodiment can refer to Figure 6 .

[0052] The backlight module 1000 in this embodiment includes: a light-emitting unit 10; an optical film 20, wherein the light provided by the light-emitting unit 10 propagates along a first direction F1 after passing through the optical film 20, and the first direction F1 is a direction perpendicular to a light-emitting surface k1 of the backlight module; a dimming layer 30 located on a side of the optical film 20 close to the light-emitting surface k1 of the backlight module, the dimming layer 30 includes a plurality of dimming units 300, and the dimming units 300 include a first surface 3001 and a second surface 3002 arranged opposite to each other along the first direction F1, the first surface 3001 is located on a side of the second surface 3002 close to the light-emitting surface k1 of the backlight module, and the second surface 3002 includes at least a first sub-surface 3001. 002a and the second sub-surface 3002b, the first surface 3001 is a plane, along the second direction F2, the plane where the first sub-surface 3002a is located intersects with the plane where the first surface 3001 is located, and the first sub-surface 3002a is inclined toward the side away from the light-emitting surface k1 of the backlight module, along the third direction F3, the plane where the second sub-surface 3002b is located intersects with the plane where the first surface 3001 is located, and the second sub-surface 3002b is inclined toward the side away from the light-emitting surface k1 of the backlight module; the first direction F1, the second direction F2 and the third direction F3 all intersect, and the second direction F2 and the third direction F3 are both parallel to the light-emitting surface k1 of the backlight module.

[0053] Specifically, the backlight module 1000 of the present invention may be an edge-type backlight module or a direct-type backlight module. Figure 4 and Figure 5 In the figure, the backlight module 1000 is only taken as an edge-type backlight module for schematic illustration. Figure 5As shown in , the light emitting surface k2 of the light emitting unit 10 of the edge-entry backlight module 1000 intersects with the light emitting surface k1 of the backlight module 1000. The backlight module 1000 has a housing 1, the housing 1 includes a bottom plate 11 and a side plate 12, the side plate 12 and the floor form a receiving cavity to accommodate the optical film 20 and the dimming layer 30, the side plate 12 includes a first side plate 12a, a second side plate 12b, a third side plate 12c and a fourth side plate 12d, the first side plate 12a and the second side plate 12b are located on opposite sides of the bottom plate 11 along the column direction Y, the third side plate 12c and the fourth side plate 12d are located on opposite sides of the bottom plate 11 along the row direction X, and a receiving cavity is formed between the bottom plate 11, the first side plate 12a, the second side plate 12b, the third side plate 12c and the fourth side plate 12d, and the light emitting unit 10 is located between the optical film 20 and the first side plate 12a.

[0054] Optionally, the optical film 20 may include a light guide plate 3, the light guide plate 3 is opposite to the light emitting unit 10 in the column direction Y, and the optical film 20 also includes a lower diffuser 40 located on the side of the light guide plate 3 close to the light emitting surface k1 of the backlight module, and a reflector 80 is also included on the side of the light guide plate 3 away from the light emitting surface k1 of the backlight module, and a mesh point 31 is also provided on the light guide plate 3. Of course, an upper diffuser 60 is also included on the side of the dimming layer 30 away from the optical film 20, and a light shielding film 70 is also provided at the position of the backlight module 1000 corresponding to the non-display area. The light shielding film 70 is located on the side of the light emitting unit 10 away from the bottom plate 11, and is used to prevent light leakage from the non-display area.

[0055] Figure 6 The dimming layer 30 in the embodiment has a plurality of dimming units 300. Figure 6 The dimming units 300 are only closely arranged for schematic illustration. Of course, the dimming units 300 may also have a certain interval, which is not shown here. Figure 5 For the dimming layer 30 , the second surface 3002 of the dimming unit 300 mainly deflects the light emitted from the optical film 20 . Figure 6 The number of dimming units 300 is only for illustrative purposes and is not intended to limit the number of dimming units 300 in an actual product. Figures 6 to 8 The dimming unit 300 is not pattern filled.

[0056] The dimming unit 300 includes a first surface 3001 and a second surface 3002 which are arranged relatively to each other along a first direction F1. The first surface 3001 is located on a side of the second surface 3002 close to the light emitting surface k1 of the backlight module. The first surface 3001 is a plane, that is, the side of the dimming unit 300 close to the light emitting surface k1 of the backlight module is a plane, and the first surface 3001 has no effect on light deflection.

[0057] Combination Figure 5 and Figure 6The second surface 3002 at least includes a first sub-surface 3002a and a second sub-surface 3002b. Along the second direction F2, the plane where the first sub-surface 3002a is located intersects with the plane where the first surface 3001 is located, and the first sub-surface 3002a is inclined toward a side away from the light-emitting surface k1 of the backlight module. The first direction F1 intersects with the second direction F2, and the second direction F2 is parallel to the light-emitting surface k1 of the backlight module. Figure 7 As shown in , the light L11 enters the dimming unit 300. Since the first sub-surface 3002a is inclined toward the side away from the light-emitting surface k1 of the backlight module, and the refractive index of the dimming unit 300 is greater than the refractive index of the air, the light L11 passes through the first sub-surface 3002a and is emitted as light L12. The light L12 is deflected in a direction with a small angle and has a certain angle with the first direction F1. Along the third direction F3, the plane where the second sub-surface 3002b is located intersects with the plane where the first surface 3001 is located, and the second sub-surface 3002b is inclined toward the side away from the light-emitting surface k1 of the backlight module. The first direction F1 intersects with the third direction F3, and the second direction F2 and the third direction F3 are both parallel to the light-emitting surface k1 of the backlight module. Figure 8 As shown in , the light L21 enters the dimming unit 300. Since the second sub-surface 3002b is inclined to the side away from the light-emitting surface k1 of the backlight module, and the refractive index of the dimming unit 300 is greater than the refractive index of the air, the light L21 passes through the first sub-surface 3002a and is emitted as light L22. The light L22 is deflected in a direction with a small angle and has a certain angle with the first direction F1. The inclination angles of the first sub-surface 3002a and the second sub-surface 3002b are θ1 and θ2 respectively, and θ1 and θ2 may be equal or unequal, and are not specifically limited here. Of course, when θ1 and θ2 are equal, the angles of deflection of the light in the first direction F1 and the second direction F2 are the same.

[0058] It should be noted that in the present invention, the light emitted from the optical film 20 is considered to be non-directional, that is, the light after passing through the optical film 20 propagates in a direction perpendicular to the light emitting surface k1 of the backlight module, and then enters the dimming layer 30. In addition, the refractive index of the dimming layer 30 here is greater than the refractive index of the air. The light emitted from the optical film 20 enters the air between the optical film 20 and the dimming layer 30, and then enters the dimming layer 30 from the air, which is equivalent to entering from sparse light to dense light.

[0059] In some optional embodiments, the material of the dimming layer 30 includes polymethyl methacrylate, whose refractive index n2 is generally 1.49, and the refractive index n1 of air is 1.00029, that is, the refractive index of the dimming layer 30 is greater than that of air. In addition, the small viewing angle area A+ area referred to in the present invention refers to the area with an angle of less than 10° with the first direction F1. According to the refractive index formula n1sinα1=n2sinα2, the light enters the dimming layer 30 from the air and undergoes one refraction. When it is emitted from the dimming layer 30 and enters the upper layer (the side of the dimming layer 30 close to the light-emitting surface k1 of the backlight module), it undergoes another refraction. To make the light deflected to about 10° (i.e., the angle between the light and the first direction F1 after it is emitted from the dimming layer 30 and enters the upper layer of air is about 10°), it can be calculated that the inclination angle of the first sub-surface 3002a and the second sub-surface 3002b is about 3.5°. Of course, the inclination overlap of the first sub-surface 3002a and the second sub-surface 3002b also changes with the different refractive indexes of the materials, which is not specifically limited here. By analyzing the backlight module of this embodiment through ANSYS software, it can be known that the light emitted by the backlight module will be biased to the small viewing angle area.

[0060] Combination Figure 7 and Figure 8 , the first sub-surface 3002a and the second sub-surface 3002b are two sub-surfaces intersecting in the second direction F2 and the third direction F3. It can be understood that along the second direction F2, the dimming unit 300 has a surface inclined toward the side away from the light-emitting surface k1 of the backlight module, and along the third direction F3, the dimming unit 300 also has a surface inclined toward the side away from the light-emitting surface k1 of the backlight module. In this way, the dimming unit 300 can deflect light in both the second direction F2 and the third direction F3, so that the luminous flux in the second direction F2 and the third direction F3 can be increased. After the luminous flux in the second direction F2 and the third direction F3 increases, the contrast ratio will increase. Fig. 9 It can be seen from the contrast contour map that after the dimming layer 30 is set in the backlight module 1000 of the present invention, the contour line with a contrast of 1300 is expanded in the left-right direction and the up-down direction, so that the contrast of the small viewing angle area A+ zone is completely covered by the contour line with a contrast of 1300, so that the contrast of the small viewing angle area A+ zone can meet the requirements.

[0061] It should be noted that the contrast ratio in the present invention refers to the brightness ratio of the brightest white and the darkest black when the backlight module 1000 is emitting light. When the light output from the optical film 20 is deflected to the small viewing angle area A+ and the luminous flux increases, the brightness of the brightest white will increase, so the contrast ratio will also increase.

[0062] The height, size, spacing, arrangement, material, surface treatment method, etc. of the dimming unit 300 in the first direction can be adjusted according to product differences to meet other different viewing angle contrast requirements.

[0063] Compared with the related art, the backlight module 1000 of this embodiment has at least the following beneficial effects:

[0064] In the present invention, the dimming layer 30 is used to replace the prism sheet in the related art. The prism sheet in the related art needs to be provided with two layers of prism strips (refer to Figure 2 The structure of the present invention is that one layer of prism strips extends along the row direction X and is arranged in the column direction Y, and another layer of prism strips extends along the column direction Y and is arranged in the row direction X. The manufacturing process is relatively complicated. The present invention only uses one layer of dimming layer 30 to replace the prism sheet in the related art, and the manufacturing process is simple without increasing the cost.

[0065] The prism sheet in the related art deflects light at too large an angle, resulting in more light at a large viewing angle and less light at a small viewing angle, so that the contrast in the small viewing angle area cannot meet the requirements. The dimming layer 30 in the present invention includes a plurality of dimming units 300, and the dimming unit 300 includes a first surface 3001 and a second surface 3002 arranged relatively along a first direction F1, the first surface 3001 is located on the side of the second surface 3002 close to the light-emitting surface k1 of the backlight module, and the second surface 3002 includes at least a first sub-surface 3002a and a second sub-surface 3002b. Along the second direction F2, the dimming unit 300 has a surface inclined toward the side away from the light-emitting surface k1 of the backlight module, and along the third direction F3, the dimming unit 300 also has a surface inclined toward the side away from the light-emitting surface k1 of the backlight module. , so that the dimming unit 300 can deflect the light in both the second direction F2 and the third direction F3, so that the light in the second direction F2 and the third direction F3 can be increased, and the contrast will increase after the luminous flux in the second direction F2 and the third direction F3 increases, so that the luminous flux in the small viewing angle area after deflection increases, and the contour line with a contrast of 1300 is expanded in the left and right directions and the up and down directions, so that the contrast of the small viewing angle area A+ zone is completely covered by the contour line with a contrast of 1300, so that the contrast of the small viewing angle area A+ zone can meet the requirements.

[0066] In some optional embodiments, referring to Fig.10 , Fig.11 and Fig.12 , Fig.10 is a structural schematic diagram of a dimming unit provided by the present invention, Fig.11 is a schematic diagram of the orthographic projection of the dimming unit on the first section, Fig.12300 includes a substrate portion 6001 and a microstructure 6002 that are bonded together. The substrate portion 6001 includes a first surface 3001. The microstructure 6002 includes a second surface 3002 and a third surface 3003 located on the second surface 3002 and close to the substrate portion 6001. The third surface 3003 is a plane. The first vertical plane 5001 along the first direction F1 passes through the first sub-surface 3002a and the third surface 3003. Fig.11 As shown, the positive projection shape of the microstructure 6002 on the first section 4001 is a right triangle. The first section 4001 passes through the first sub-surface 3002a, the third surface 3003 and the first vertical surface 5001. The angle formed by the third surface 3003 and the first vertical surface 5001 is a right angle. The second vertical surface 5002 along the first direction F1 passes through the second sub-surface 3002b and the third surface 3003. Fig.12 As shown, the positive projection shape of the microstructure 6002 on the second section 4002 is a right triangle. The second section 4002 passes through the second sub-surface 3002b, the third surface 3003 and the second vertical surface 5002. The angle formed by the third surface 3003 and the first vertical surface 5001 is a right angle.

[0067] Fig.10 A dimming unit 300 is shown in the figure. Of course, the substrate part 6001 and the microstructure 6002 of the dimming unit 300 can be an integral structure, and the microstructure 6002 can be formed by etching or other methods. It can be understood that the orthographic projection of the first vertical plane 5001 on the microstructure 6002 is a straight line. Similarly, the orthographic projection of the second vertical plane 5002 on the microstructure 6002 is a straight line. The orthographic projection shape of the microstructure 6002 on the first section 4001 is a right triangle. The orthographic projection shape of the microstructure 6002 on the second section 4002 is a right triangle. The microstructure 6002 includes a first sub-surface 3002a and a second sub-surface 3002b. Along the second direction F2, the microstructure 6002 has a first sub-surface 3002a inclined toward the side away from the light emitting surface k1 of the backlight module. At the same time, along the third direction On F3, the microstructure 6002 also has a second sub-surface 3002b inclined toward a side away from the light-emitting surface k1 of the backlight module. The light in the first direction F1 will be deflected after passing through the first sub-surface 3002a and the second sub-surface 3002b of the microstructure 6002, and the microstructure 6002 can deflect the light in both the second direction F2 and the third direction F3, so that the light in the second direction F2 and the third direction F3 can be increased. After the luminous flux in the second direction F2 and the third direction F3 is increased, the contrast will increase, so that the luminous flux in the small viewing angle area after deflection is increased, such as Fig. 9As shown, the contour line with a contrast ratio of 1300 is expanded in the left-right direction and the up-down direction, so that the contrast of the small viewing angle area A+ is completely covered within the contour line with a contrast ratio of 1300, so that the contrast of the small viewing angle area A+ can meet the requirements.

[0068] In some optional embodiments, referring to Fig.13 , Fig.14 and Fig.15 , Fig.13 is a structural schematic diagram of another dimming layer provided by the present invention, Fig.14 This is a schematic diagram of the orthographic projection of the dimming unit on the first section. Fig.15 300 is a schematic diagram of the orthographic projection of the dimming unit on the second cross section. The dimming unit 300 includes a laminated substrate portion 6001 and a microstructure 6002. The substrate portion 6001 includes a first surface 3001. The microstructure 6002 includes a second surface 3002 and a third surface 3003 located on the second surface 3002 close to the substrate portion 6001. The third surface 3003 is a plane. Fig.14 , the first vertical plane 5001 along the first direction F1 passes through the first sub-surface 3002a and the third surface 3003, the positive projection shape of the microstructure 6002 on the first section 4001 is a right triangle, the first section 4001 passes through the first sub-surface 3002a, the third surface 3003 and the first vertical plane 5001, and the angle formed by the third surface 3003 and the first vertical plane 5001 is a right angle, Fig.15 In the figure, the orthographic projection shape of the microstructure 6002 on the second section 4002 is an isosceles triangle, and the second section 4002 passes through the second sub-surface 3002 b and the third surface 3003 .

[0069] Fig.13 The dimming layer 30 is not pattern filled, and the dimming layer 30 has a plurality of dimming units 300. Fig.13 The dimming units 300 are arranged closely without any intervals as an example for schematic illustration.

[0070] The substrate part 6001 and the microstructure 6002 of the dimming unit 300 can be an integral structure, and the microstructure 6002 can be formed by etching or other methods. It can be understood that the orthographic projection of the first vertical plane 5001 on the microstructure 6002 is a straight line, the orthographic projection shape of the microstructure 6002 on the first section 4001 is a right triangle, and the orthographic projection shape of the microstructure 6002 on the second section 4002 is an isosceles triangle. The microstructure 6002 includes a first sub-surface 3002a and a second sub-surface 3002b. Along the second direction F2, the microstructure 6002 has a first sub-surface 3002a inclined toward the side away from the light-emitting surface k1 of the backlight module, and along the third direction F3, the microstructure 6002 also has a second sub-surface 3002b inclined toward the side away from the light-emitting surface k1 of the backlight module, and Fig.15 It is shown in the figure that the second sub-surface 3002b plays a dimming role as the two waists of the isosceles triangle. The light in the first direction F1 will be deflected after passing through the first sub-surface 3002a and the second sub-surface 3002b of the microstructure 6002, and the microstructure 6002 can deflect the light in the second direction F2 and the third direction F3 at the same time, so that the light in the second direction F2 and the third direction F3 can be increased. After the luminous flux in the second direction F2 and the third direction F3 is increased, the contrast will increase, so that the luminous flux in the small viewing angle area after deflection is increased, as shown in FIG. Fig.16 As shown, Fig.16 Is adopted Fig.13 The schematic diagram of the light output contrast contour lines of the backlight module 1000 after the dimming layer 30 is shown in the figure. The contour line with a contrast ratio of 1300 is enlarged in the left and right directions, especially in the up and down directions, so that the contrast of the small viewing angle area A+ zone is completely covered by the contour line with a contrast ratio of 1300, so that the contrast of the small viewing angle area A+ zone can meet the requirements.

[0071] In some optional embodiments, continue to refer to Figure 7 , Figure 8 , Fig.11 , Fig.12 , Fig.14 and Fig.15 The included angle between the first sub-surface 3002a and the light emitting surface k1 of the backlight module is greater than or equal to 2° and less than or equal to 5°, and the included angle between the second sub-surface 3002b and the light emitting surface k1 of the backlight module is greater than or equal to 2° and less than or equal to 5°.

[0072] In the present invention, the light emitted from the optical film 20 is considered to be non-directional, that is, the light after passing through the optical film 20 propagates in a direction perpendicular to the light-emitting surface k1 of the backlight module, and then enters the dimming layer 30. In addition, the refractive index of the dimming layer 30 here is greater than the refractive index of the air. The light emitted from the optical film 20 enters the air between the optical film 20 and the dimming layer 30, and then enters the dimming layer 30 from the air, which is equivalent to entering from light sparse to light dense. Optionally, the material of the dimming layer 30 can be PMA (polymethyl acrylate), whose refractive index is generally 1.49, and the refractive index of air is 1.00029, that is, the refractive index of the dimming layer 30 is greater than the refractive index of air. In addition, the small viewing angle area A+ area referred to in the present invention refers to an area with an angle of 10° with the first direction F1. According to the refractive index formula n1sinα1=n2sinα2, it can be calculated that the inclination angle of the first sub-surface 3002a and the second sub-surface 3002b is about 3.5°, which can make the light deflected to about 10°. Of course, the inclination overlap of the first sub-surface 3002a and the second sub-surface 3002b will also change due to the different refractive indices of the materials. Considering the process errors when making the first sub-surface 3002a and the second sub-surface 3002b, it is prevented that the angle between the first sub-surface 3002a and the light-emitting surface k1 of the backlight module is too large or too small, and the angle between the second sub-surface 3002b and the light-emitting surface k1 of the backlight module is too large or too small due to the process errors, resulting in the final light being deflected from the first direction F1. The angle between the first sub-surface 3002a and the light-emitting surface k1 of the backlight module exceeds 10°, so the angle between the first sub-surface 3002a of the present invention and the light-emitting surface k1 of the backlight module is greater than or equal to 2° and less than or equal to 5°, and the angle between the second sub-surface 3002b and the light-emitting surface k1 of the backlight module is greater than or equal to 2° and less than or equal to 5°. In this way, even if there are process errors in the production of the first sub-surface 3002a and the second sub-surface 3002b, it can be ensured that the angle between the first sub-surface 3002a and the light-emitting surface k1 of the backlight module is not too large or too small, and the angle between the second sub-surface 3002b and the light-emitting surface k1 of the backlight module is not too large or too small. Finally, the angle between the light ray and the first direction F1 after deflection does not exceed 10°, thereby achieving that the contrast of the small viewing angle area A+ zone is completely covered within the contour line with a contrast ratio of 1300, so that the contrast of the small viewing angle area A+ zone can meet the requirements.

[0073] In some optional embodiments, continue to refer to Figure 6 and Fig.13 The orthographic projection areas of the dimming units 300 on the light-emitting surface k1 of the backlight module are all equal, and there is no interval between adjacent dimming units 300 .

[0074] It is understandable that the dimming unit 300 is used to deflect the light emitted from the optical film 20 (the light emitted from the optical film 20 is deflected toward the small viewing angle area A+ after passing through the dimming unit 300), so the closer the dimming units 300 are arranged, the more uniform the deflection effect on the light emitted from the optical film 20 is. If intervals are set between the dimming units 300, then there will definitely be light emitted from the optical film 20 that is directly emitted from the intervals between the dimming units 300, and this part of the light is not deflected, but continues to be emitted along the first direction F1, so that only the light at the corresponding position of the dimming unit 300 will be deflected to the small viewing angle area A+, resulting in uneven light emission from the backlight module 1000. In this embodiment, there is no gap between adjacent dimming units 300, so that all light emitted from the optical film 20 will pass through the dimming unit 300. The dimming unit 300 deflects all light emitted from the optical film 20 to the small viewing angle area A+, and the light emitted by the backlight module 1000 is more uniform.

[0075] Of course, the orthographic projection areas of the dimming units 300 on the light-emitting surface k1 of the backlight module are all equal. On the one hand, the shapes of the dimming units 300 are all the same, which is convenient for manufacturing. Specifically, because the second surface 3002 of the dimming unit 300 has an inclined surface, it is easier to implement the structure in which the inclined surface has the same inclined angle and inclined area. On the other hand, the orthographic projection areas of the dimming units 300 on the light-emitting surface k1 of the backlight module are all equal, so that the light emitted from different positions of the optical film 20 is deflected by the dimming units 300 of the same structure, and the light deflection angles are all the same, making the light emitted by the backlight module 1000 more uniform.

[0076] In some optional embodiments, continue to refer to Figure 6 and Fig.13 A plurality of dimming units 300 are arranged along a second direction F2 to form a dimming unit 300 row, and a plurality of dimming units 300 are arranged along three directions to form a dimming unit 300 column. The second direction F2 is parallel to the row direction X, and the third direction F3 is parallel to the column direction Y.

[0077] In this embodiment, the second direction F2 is parallel to the row direction X, and the third direction F3 is parallel to the column direction Y, that is, the dimming units 300 are arranged along the row direction X to form a dimming unit 300 row, and the dimming units 300 are arranged along the column direction Y to form a dimming unit 300 column. In the row direction X and the column direction Y, the light emitted by the optical film 20 is deflected at the same time, so that the luminous flux in the small viewing angle area after deflection is increased, and the contour line with a contrast of 1300 is enlarged in the left and right directions and the up and down directions. In this way, the contrast of the small viewing angle area A+ is completely covered within the contour line with a contrast of 1300, so that the contrast of the small viewing angle area A+ can meet the requirements.

[0078] In some optional embodiments, referring to Fig.17 and Fig.18 , and continue to refer to Figure 7 , Figure 8 , Fig.14 and Fig.15 , Fig.17 is a structural schematic diagram of another dimming layer provided by the present invention, Fig.17 The viewing angle is the upward viewing angle. Fig.18 Is adopted Fig.17 Schematic diagram of the light output contrast contour of the backlight module behind the dimming layer, multiple dimming units 300 are arranged along the second direction F2 to form a dimming unit 300 row, multiple dimming units 300 are arranged along three directions to form a dimming unit 300 column, the second direction F2 and the row direction X The angle is 40°, and the angle between the second direction F2 and the column direction Y is 50°.

[0079] The dimming units 300 in this embodiment are not arranged along the row direction X but at an angle of 40° to the row direction X. Meanwhile, the dimming units 300 are not arranged along the column direction Y but at an angle of 50° to the column direction Y. The structure of the second surface 3002 in the dimming unit 300 can be referred to. Figure 7 , Figure 8 or Fig.14 and Fig.15 The structure of is not described here.

[0080] Combination Fig.18 In this embodiment, since the dimming unit 300 has a surface inclined toward the side away from the light emitting surface k1 of the backlight module along the second direction F2, and the dimming unit 300 also has a surface inclined toward the side away from the light emitting surface k1 of the backlight module along the third direction F3, the dimming unit 300 can deflect the light in both the second direction F2 and the third direction F3, so that the light in the second direction F2 and the third direction F3 can be increased, and the contrast will increase after the luminous flux in the second direction F2 and the third direction F3 increases. At the same time, since multiple dimming units 300 are arranged along the second direction F2 to form a dimming unit 300 row, the angle between the second direction F2 and the row direction X is 40°, and multiple dimming units 300 are arranged along three directions to form a dimming unit 300 column, the angle between the second direction F2 and the column direction Y is 50°, which is equivalent to rotating the contrast contour line by a certain angle on the basis of increasing the contrast after the luminous flux in the second direction F2 and the third direction F3 increases. After the rotation, the contrast of the small viewing angle area A+ zone is completely covered by the contour line with a contrast of 1300, so that the contrast of the small viewing angle area A+ zone can meet the requirements.

[0081] In some optional embodiments, referring to Fig.19 and Fig. 20 , Fig.19 is a schematic diagram of a planar structure of another backlight module provided by the present invention. Fig.19 The optical film 20 and other structures are not shown, and only the structure of the dimming layer 30 is shown. Fig. 20 yes Fig.19 Schematic diagram of the contrast contour of the light output of the backlight module. In this embodiment, the backlight module 1000 includes a center point 10001 and a boundary 10002. In the direction from the center point 10001 to the boundary 10002, multiple dimming units 300 are arranged in concentric circles.

[0082] Fig.19 The backlight module 1000 is not pattern filled. The dimming units 300 are arranged in concentric circles with the center point 10001 of the backlight module 1000 as the center of the circle, and the dimming units 300 are arranged in a direction from the center point 10001 to the boundary 10002. Fig.19 The number of dimming units 300 in the figure is only for illustrative purposes and is not intended to limit the number of dimming units 300 in an actual product. The boundary 10002 of the backlight module 1000 is not specifically limited here. Fig.19 In the figure, the border 10002 of the backlight module 1000 is taken as a rectangle for example, but it can also be a circle or other shapes.

[0083] In this embodiment, multiple dimming units 300 are arranged in concentric circles, which is equivalent to deflecting the light output from the optical film 20 in the circumferential direction. The contrast contour line after the deflection is close to a circle. In addition, it has a first sub-surface 3002a and a second sub-surface 3002b, so the light output from the optical film 20 is deflected in the direction from the center point 10001 to the boundary 10002 and in the direction intersecting with the direction from the center point 10001 to the boundary 10002, so that the contour line with a contrast of 1300 is enlarged in the left and right directions and the up and down directions, and the contrast contour line after the deflection is close to a circle, and the contrast of the small viewing angle area A+ is completely covered by the contour line with a contrast of 1300, so that the contrast of the small viewing angle area A+ can meet the requirements.

[0084] In some optional embodiments, referring to Fig.21 , Fig.21 yes Fig.19 In the dimming unit 300 provided by the present invention, the first sub-surface 3002a includes a first end 701 and a second end 702, the first end 701 is located on the side of the second end 702 close to the center point 10001, and the distance between the first end 701 and the optical film 20 is smaller than the distance between the second end 702 and the optical film 20.

[0085] Fig.21 The dimming unit 300 and the optical film 20 are not pattern filled. Fig.19It can be seen that along the first direction F1, the side of the dimming unit 300 close to the center point 10001 is closer to the optical film 20, while the side away from the center point 10001 is farther from the optical film 20. Fig.21 From the path of the middle light, it can be seen that the light output from the optical film 20 is deflected to one side of the center point 10001 as a whole after passing through the first sub-surface 3002a. Of course, the deflection direction can be controlled to be around 10° by setting the angle between the first sub-surface 3002a and the light-emitting surface k1 of the backlight module, that is, the amount of light output in the small viewing angle area A+ is increased, and the large-angle luminous flux is reduced. The contrast of the small viewing angle area A+ is completely covered within the contour line of contrast of 1300, so that the contrast of the small viewing angle area A+ can meet the requirements.

[0086] In some optional embodiments, continue to refer to Fig.19 The orthographic projection area of ​​the dimming unit 300 close to the center point 10001 on the light-emitting surface k1 of the backlight module is smaller than the orthographic projection area of ​​the dimming unit 300 far from the center point 10001 on the light-emitting surface k1 of the backlight module.

[0087] Fig.19 Concentric circles M1, M2, M3, and M4 are schematically shown. Of course, the number of concentric circles is not specifically limited here. From the center point 10001 to the boundary 10002, the radius of the concentric circles gradually increases. The radius of the concentric circle M1 is smaller than the radius of the concentric circle M2, the radius of the concentric circle M2 is smaller than the radius of the concentric circle M3, and the radius of the concentric circle M3 is smaller than the radius of the concentric circle M4. Of course, the denser the arrangement of the dimming units 300, the more uniform the light deflection effect on the optical film 20. In order to arrange the dimming units 300 densely without any gaps between them, the orthographic projection area of ​​the dimming units 300 close to the center point 10001 on the light-emitting surface k1 of the backlight module is smaller than the orthographic projection area of ​​the dimming units 300 far from the center point 10001 on the light-emitting surface k1 of the backlight module, and there is no gap between adjacent dimming units 300. In this way, the light emitted by all optical films 20 will pass through the dimming units 300. The dimming units 300 deflect all the light emitted by the optical film 20 to the small viewing angle area A+, and the light emitted by the backlight module 1000 is more uniform. If intervals are set between the dimming units 300, then the light emitted by the optical film 20 will definitely be emitted directly from the intervals between the dimming units 300, and this part of the light will not be deflected, but will continue to be emitted along the first direction F1. In this way, only the light at the corresponding position of the dimming unit 300 will be deflected to the small viewing angle area A+, resulting in uneven light emission of the backlight module.

[0088] In some optional embodiments, referring to Fig. 22 , Fig.23 , Fig.24 and Fig.25 , Fig. 22 is a schematic diagram of the structure of another dimming layer provided by the present invention. Fig.23 yes Fig. 22 A cross-sectional view along the E-E' direction, Fig.24 yes Fig. 22 A cross-sectional view along the F-F' direction, Fig.25 Is adopted Fig. 22 Schematic diagram of the contrast contour of the light emitted by the backlight module behind the dimming layer. In this embodiment, both the first sub-surface 3002a and the second sub-surface 3002b are curved surfaces.

[0089] Fig. 22 The close arrangement of adjacent dimming units 300 is only schematically shown. Figure 22 to Figure 24 , along the second direction F2, the first sub-surface 3002a protrudes toward the side away from the light-emitting surface k1 of the backlight module and the first sub-surface 3002a is an arc surface, the plane where the first sub-surface 3002a is located intersects with the plane where the first surface 3001 is located, the first direction F1 intersects with the second direction F2, and the second direction F2 is parallel to the light-emitting surface k1 of the backlight module. Fig.23 As shown in the figure, the light L11 enters the dimming unit 300. Since the first sub-surface 3002a is a curved surface and the refractive index of the dimming unit 300 is greater than the refractive index of the air, the light L11 passes through the first sub-surface 3002a and is emitted as light L12. The light L12 is deflected in a direction with a small angle and has a certain angle with the first direction F1.

[0090] Along the third direction F3, the second sub-surface 3002b protrudes toward the side away from the light-emitting surface k1 of the backlight module and the second sub-surface 3002b is a curved surface. The plane where the second sub-surface 3002b is located intersects with the plane where the first surface 3001 is located. The first direction F1 intersects with the third direction F3. The third direction F3 is parallel to the light-emitting surface k1 of the backlight module. Fig.24 As shown in the figure, the light L21 enters the dimming unit 300. Since the second sub-surface 3002b is a curved surface convex to the side away from the light-emitting surface k1 of the backlight module, and the refractive index of the dimming unit 300 is greater than the refractive index of the air, the light L21 passes through the first sub-surface 3002a and is emitted as light L22. The light L22 is deflected in a direction with a small angle and has a certain angle with the first direction F1.

[0091] Combination Fig.23 and Fig.24The first sub-surface 3002a and the second sub-surface 3002b are two sub-surfaces intersecting in the second direction F2 and the third direction F3. It can be understood that along the second direction F2, the dimming unit 300 has a curved surface protruding toward the side away from the light-emitting surface k1 of the backlight module. At the same time, along the third direction F3, the dimming unit 300 also has a curved surface protruding toward the side away from the light-emitting surface k1 of the backlight module. In this way, the first sub-surface 3002a and the second sub-surface 3002b can deflect the light in both the second direction F2 and the third direction F3, so that the light in the second direction F2 and the third direction F3 can be increased. When the luminous flux in the second direction F2 and the third direction F3 increases, the luminous contrast of the backlight module will increase. Fig.25 It can be seen from the contrast contour map that the backlight module 1000 of the present invention is provided with a dimming layer 30, and the first sub-surface 3002a and the second sub-surface 3002b in the dimming unit 300 of the dimming layer 30 are both curved surfaces, and the contour line with a contrast ratio of 1300 is expanded in the left-right direction and the up-down direction, so that the contrast of the small viewing angle area A+ zone is completely covered by the contour line with a contrast ratio of 1300, so that the contrast of the small viewing angle area A+ zone can meet the requirements.

[0092] In some optional embodiments, continue to refer to Figure 22 to Figure 25 The second surface 3002 of the dimming unit 300 forms a micro lens 800 that protrudes toward a side away from the light emitting surface k1 of the backlight module.

[0093] As an important optical element, the microlens 800 has the characteristics of small size, light weight and high integration. The microlens 800 can have a converging effect or a diverging effect. The second surface 3002 of the dimming unit 300 in the present invention constitutes a microlens 800 that protrudes away from the light-emitting surface k1 of the backlight module, so it has a diverging effect, and the diverging direction is along the circumferential direction. In this way, the microlens 800 can deflect the light in the circumferential direction at the same time, so that the light in the circumferential direction can be increased. After the luminous flux in the circumferential direction increases, the contrast will increase. Fig.25 It can be seen from the contrast contour diagram that the backlight module 1000 of the present invention is provided with a dimming layer 30, and the second surface 3002 of the dimming unit 300 constitutes a microlens 800 that protrudes toward the side away from the light-emitting surface k1 of the backlight module. The contour lines with a contrast of 1300 are all expanded in the circumferential direction, so that the contrast of the small viewing angle area A+ zone is completely covered by the contour lines with a contrast of 1300, so that the contrast of the small viewing angle area A+ zone can meet the requirements.

[0094] In some optional embodiments, continue to refer to Fig. 22 , Fig.23 and Fig.24, the projection area of ​​the microlens 800 on the plane where the second direction F2 is located is equal to the projection area on the plane where the third direction F3 is located.

[0095] Understandably, Fig.23 It can be understood as the positive projection of the microlens 800 on the plane where the second direction F2 is located. Fig.24 It is the orthographic projection of the microlens 800 on the plane where the third direction F3 is located. Optionally, the microlens 800 is a hemispherical shape convex toward the side away from the light-emitting surface k1 of the backlight module. The projection area of ​​the microlens 800 on the plane where the second direction F2 is located is equal to the projection area on the plane where the third direction F3 is located. On the one hand, it is convenient to manufacture the microlens 800. On the other hand, the projection area of ​​the microlens 800 on the plane where the second direction F2 is located is equal to the projection area on the plane where the third direction F3 is located. In this way, after the light passes through the microlens 800, the deflection angles of the second direction F2 and the third direction F3 after being adjusted are roughly the same, so that the light output of the backlight module 1000 is more uniform.

[0096] It should be noted that if the microlens 800 is set to protrude toward the side of the light-emitting surface k1 of the backlight module, the light emitted from the dimming layer 30 will be focused before reaching the cover plate of the display device, resulting in regular bright spots in the small viewing angle area A+, similar to firefly dots. The microlens 800 of the present invention protrudes toward the side away from the light-emitting surface k1 of the backlight module, and the light emitted from the dimming layer 30 is not focused before reaching the panel, which will not cause regular bright spots in the small viewing angle area A+.

[0097] In some optional embodiments, referring to Fig. 22 , Fig.23 and Fig.24 The projection of the microlens 800 on the plane where the second direction F2 is located and the projection on the plane where the third direction F3 is located are both arcuate, the radius of the arcuate is r, and the width of the arcuate is w, wherein w / 2r=cos71°.

[0098] Understandably, Fig.23The projection of the microlens 800 on the plane where the second direction F2 is located is shown, and the projection is an arcuate shape. In the design of the microlens 800 in this embodiment, the simulation experiment can be used to design and set parameters, the refractive index of air is n1=1, the refractive index of the microlens 800 is n2=1.49, the radius of the microlens 800 in the second direction F2 and the third direction F3 are equal, the width w and radius r of the microlens 800 are set, and the light emission angle of the backlight module 1000 under the current setting is simulated; the above parameters are adjusted, and the simulation results are updated to confirm the light emission angle of the backlight module 1000; so many rounds of repeated iterations, finally when w / 2r=cos71°, the simulated light emission angle reaches about 10° in the small viewing angle area A. In the direction perpendicular to the plane where the light emitting surface k1 of the backlight module is located, the thickness d of the microlens 800 is r(1-sin71°).

[0099] In some optional embodiments, continue to refer to Figures 6 to 8 The refractive index of the dimming layer 30 is between 1.49 and 1.51.

[0100] Specifically, the small viewing angle area A+ area referred to in the present invention refers to an area with an angle of 10° with the first direction F1, that is, the angle between the light emitted from the optical film 20 and the first direction F1 after passing through the dimming layer 30 is about 10°. According to the refractive index formula n1sinα1=n2sinα2, the light enters the dimming layer 30 from the air and undergoes one refraction, and then is emitted from the dimming layer 30 and enters the upper layer (the side of the dimming layer 30 close to the light-emitting surface k1 of the backlight module) and undergoes another refraction. The light is deflected to about 10° (that is, the angle between the light emitted from the dimming layer 30 and the first direction F1 is about 10° after entering the upper layer of air). The refractive index of the dimming layer 30 is greater than that of the air. The refractive index n1 of the air is 1.00029. The material of the dimming layer 30 includes polymethyl methacrylate. After simulation experiments, the refractive index n2 can be 1.49-1.51, which can ensure that the angle between the light emitted from the optical film 20 and the first direction F1 after passing through the dimming layer 30 is about 10°.

[0101] In some optional embodiments, continue to refer to Figure 4 and Figure 5 The optical film 20 includes a light guide plate 3 and a lower diffusion sheet 40 located on a side of the light guide plate 3 close to the dimming layer 30 , and the light emitting unit 10 is located on at least one side of the light guide plate 3 .

[0102] Specifically, the backlight module 1000 of this embodiment can be an edge-entry backlight module 1000, and the optical film 20 can include a light guide plate 3, which is opposite to the light emitting unit 10 in the column direction Y. In addition, the optical film 20 also includes a lower diffuser 40 located on the side of the light guide plate 3 close to the light emitting surface k1 of the backlight module. The function of the lower diffuser 40 is to uniformly process the light emitted from the bottom. The light emitting unit 10 is located on at least one side of the light guide plate 3. Figure 4 Only the light emitting unit 10 is shown on one side of the light guide plate 3 . Of course, the light emitting units 10 may also be provided on both sides of the light guide plate 3 along the column direction Y, which is not shown here.

[0103] The backlight module 1000 in the present invention is provided with a dimming unit 300 on the side of the lower diffuser 40 away from the light guide plate 3. The dimming unit 300 can deflect the light in both the second direction F2 and the third direction F3, so that the light in the second direction F2 and the third direction F3 can be increased. After the luminous flux in the second direction F2 and the third direction F3 is increased, the contrast ratio will be increased, so that the luminous flux in the small viewing angle area after deflection is increased, and the contour line with a contrast ratio of 1300 is expanded in the left-right direction and the up-down direction. In this way, the contrast ratio of the small viewing angle area A+ is completely covered within the contour line with a contrast ratio of 1300, so that the contrast ratio of the small viewing angle area A+ can meet the requirements.

[0104] Based on the same idea, the present invention also provides a display device, referring to Fig.26 and Fig. 27 , Fig.26 A schematic diagram of a planar structure of a display device provided by the present invention, Fig. 27 yes Fig.26 A cross-sectional view taken along the G-G' direction, the display device of the present invention may include the backlight module 1000 of any of the above-mentioned embodiments, and a display panel 3000 located on the light-emitting side of the backlight module, and of course also includes liquid crystal molecules located between the display panel 2000 and the backlight module 1000. The display panel 2000 and the backlight module 1000 are not pattern-filled in the figure. Fig.26 The embodiment only takes the vehicle-mounted display device as an example to illustrate the display device 2000. It can be understood that the display device 2000 provided in the embodiment of the present invention can be a computer, a television, a mobile phone or other display device 2000 with a display function, and the present invention does not specifically limit this. The display device 2000 provided in the embodiment of the present invention has the beneficial effects of the backlight module 1000 provided in the embodiment of the present invention. For details, please refer to the specific description of the backlight module 1000 in the above embodiments, and this embodiment will not be repeated here.

[0105] It can be seen from the above embodiments that the backlight module and the display device provided by the present invention achieve at least the following beneficial effects:

[0106] In the backlight module of the present invention, the light emitted by the light-emitting unit propagates in a direction perpendicular to the light-emitting surface of the backlight module after passing through the optical film, and then is deflected by the dimming layer. The dimming layer is located on the side of the optical film close to the light-emitting surface of the backlight module. The dimming layer deflects the light perpendicular to the light-emitting surface of the backlight module to a small angle. On the one hand, the dimming layer replaces the prism sheet in the related art. The prism sheet in the related art needs to be set as two layers of prism strips, one layer of prism strips extends along the second direction and is arranged in the third direction, and the other layer of prism strips extends along the third direction and is arranged in the second direction. The manufacturing process is relatively complicated. The present invention only uses one layer of dimming layer to replace the prism sheet in the related art, and the manufacturing process is simple. On the other hand, the prism sheet in the related art deflects the light at too large an angle, resulting in more light at a large viewing angle and less light at a small viewing angle, so that the contrast of the small viewing angle area cannot meet the requirements. The dimming layer in the present invention includes a plurality of dimming units. The dimming unit includes a first surface and a second surface arranged relatively opposite to each other along a first direction. The first surface is located near the second surface. On one side near the light-emitting surface of the backlight module, the second surface at least includes a first sub-surface and a second sub-surface, the first surface is a plane, along the second direction, the plane where the first sub-surface is located intersects with the plane where the first surface is located, and the first sub-surface is inclined toward the side away from the light-emitting surface of the backlight module, and along the third direction, the plane where the second sub-surface is located intersects with the plane where the first surface is located, and the second sub-surface is inclined toward the side away from the light-emitting surface of the backlight module; the first direction, the second direction and the third direction all intersect, and the second direction and the third direction are both parallel to the light-emitting surface of the backlight module, so that the light is deflected in the second direction and the third direction at the same time, so that the luminous flux in the small viewing angle area after deflection is increased, and the contrast in the small viewing angle area meets the requirements.

[0107] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A backlight module, characterized in that: include: Light emitting unit; An optical film, wherein the light provided by the light-emitting unit propagates along a first direction after passing through the optical film, and the first direction is a direction perpendicular to the light-emitting surface of the backlight module; A dimming layer located on a side of the optical film close to the light-emitting surface of the backlight module, the dimming layer comprising a plurality of dimming units, no interval between adjacent dimming units, the refractive index of the dimming unit being greater than the refractive index of air, the dimming unit comprising a first surface and a second surface arranged opposite to each other along a first direction, the first surface being located on a side of the second surface close to the light-emitting surface of the backlight module, the second surface comprising at least a first sub-surface and a second sub-surface, the first surface being a plane, along the second direction, the plane where the first sub-surface is located intersects with the plane where the first surface is located, and the first sub-surface is inclined toward a side away from the light-emitting surface of the backlight module, and along a third direction, the plane where the second sub-surface is located intersects with the plane where the first surface is located, and the second sub-surface is inclined toward a side away from the light-emitting surface of the backlight module; The first direction, the second direction and the third direction all intersect, and the second direction and the third direction are both parallel to the light emitting surface of the backlight module; The dimming unit includes a laminated substrate portion and a microstructure, wherein the substrate portion includes the first surface, and the microstructure includes the second surface and a third surface located on the second surface close to the substrate portion, wherein the third surface is a plane, and a first vertical plane along the first direction passes through the first sub-surface and the third surface, and an orthographic projection shape of the microstructure on a first cross section is a right triangle, and the first cross section passes through the first sub-surface, the third surface and the first vertical plane, and an angle formed by the third surface and the first vertical plane is a right angle, and a second vertical plane along the first direction passes through the second sub-surface and the third surface, and an orthographic projection shape of the microstructure on a second cross section is a right triangle, and the second cross section passes through the second sub-surface, the third surface and the second vertical plane, and an angle formed by the third surface and the first vertical plane is a right angle; or, The dimming unit includes a bonded substrate portion and a microstructure, the substrate portion includes the first surface, the microstructure includes the second surface and a third surface located on the second surface close to the substrate portion, the third surface is a plane, and the first vertical plane along the first direction passes through the first sub-surface and the third surface. The orthographic projection shape of the microstructure on the first section is a right triangle, the first section passes through the first sub-surface, the third surface and the first vertical plane, the angle formed by the third surface and the first vertical plane is a right angle, and the orthographic projection shape of the microstructure on the second section is an isosceles triangle, and the second section passes through the second sub-surface and the third surface.

2. The backlight module according to claim 1, characterized in that: The included angle between the first sub-surface and the light emitting surface of the backlight module is greater than or equal to 2° and less than or equal to 5°, and the included angle between the second sub-surface and the light emitting surface of the backlight module is greater than or equal to 2° and less than or equal to 5°.

3. The backlight module according to claim 1, characterized in that: The orthographic projection areas of the dimming units on the light emitting surface of the backlight module are all equal.

4. The backlight module according to claim 1, characterized in that: A plurality of dimming units are arranged along a second direction to form a dimming unit row, and a plurality of dimming units are arranged along a third direction to form a dimming unit column. The second direction is parallel to the row direction, and the third direction is parallel to the column direction.

5. The backlight module according to claim 1, characterized in that: A plurality of dimming units are arranged along the second direction to form a dimming unit row, and a plurality of dimming units are arranged along the third direction to form a dimming unit column. The angle between the second direction and the row direction is 40°, and the angle between the second direction and the column direction is 50°.

6. The backlight module according to claim 1, characterized in that: The backlight module includes a center point and a boundary, and a plurality of dimming units are arranged in concentric circles from the center point to the boundary.

7. The backlight module according to claim 6, characterized in that: The first sub-surface includes a first end and a second end, the first end is located on a side of the second end close to the center point, and a distance between the first end and the optical film is smaller than a distance between the second end and the optical film.

8. The backlight module according to claim 7, characterized in that: The orthographic projection area of ​​the dimming unit close to the center point on the light emitting surface of the backlight module is smaller than the orthographic projection area of ​​the dimming unit far from the center point on the light emitting surface of the backlight module.

9. The backlight module according to claim 1, characterized in that: The material of the dimming layer includes polymethyl methacrylate.

10. The backlight module according to claim 1, characterized in that: The refractive index of the dimming layer is 1.49-1.

51.

11. The backlight module according to claim 1, characterized in that: The optical film comprises a light guide plate and a lower diffusion sheet located on a side of the light guide plate close to the light-adjusting layer, and the light-emitting unit is located on at least one side of the light guide plate.

12. A backlight module, characterized in that: The invention is characterized by comprising: Light emitting unit; An optical film, wherein the light provided by the light-emitting unit propagates along a first direction after passing through the optical film, and the first direction is a direction perpendicular to the light-emitting surface of the backlight module; A dimming layer located on a side of the optical film close to the light-emitting surface of the backlight module, the dimming layer comprising a plurality of dimming units, no interval between adjacent dimming units, the refractive index of the dimming unit being greater than the refractive index of air, the dimming unit comprising a first surface and a second surface arranged opposite to each other along a first direction, the first surface being located on a side of the second surface close to the light-emitting surface of the backlight module, the second surface comprising at least a first sub-surface and a second sub-surface, the first surface being a plane, along the second direction, the first sub-surface protrudes toward a side away from the light-emitting surface of the backlight module and the first sub-surface is a curved surface, the plane where the first sub-surface is located intersects with the plane where the first surface is located, along the third direction, the second sub-surface protrudes toward a side away from the light-emitting surface of the backlight module and the second sub-surface is a curved surface, the plane where the second sub-surface is located intersects with the plane where the first surface is located; The first direction, the second direction and the third direction all intersect, and the second direction and the third direction are both parallel to the light emitting surface of the backlight module.

13. The backlight module according to claim 12, characterized in that: The second surface of the dimming unit forms a micro lens protruding toward a side away from the light emitting surface of the backlight module.

14. The backlight module according to claim 13, characterized in that: The projection area of ​​the microlens on the plane where the second direction is located is equal to the projection area of ​​the microlens on the plane where the third direction is located.

15. The backlight module according to claim 13, characterized in that: The projection of the microlens on the plane where the second direction is located and the projection of the microlens on the plane where the third direction is located are both arcuate, the radius of the arcuate is r, and the width of the arcuate is w, wherein w / 2r=cos71°.

16. A display device, characterized in that: It comprises the backlight module as claimed in any one of claims 1 to 15, and a display panel located on a light emitting surface side of the backlight module.

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