Display module

Abstract

This application discloses a display module, including a liquid crystal unit and a backlight unit disposed on the back of the liquid crystal unit. The backlight unit includes at least one light guide plate, a light source disposed on one side of the light guide plate, and a reflective film disposed opposite to the bottom surface of the light guide plate. At most one optical film is accommodated between the liquid crystal unit and the light guide plate. The bottom surface of the light guide plate has a microstructure, which includes a light-uniforming section and a light-emitting angle adjustment section. The display module of this application has the advantages of good display quality and high display brightness.

Description

Technical Field

[0001] This application relates to the field of display technology, and more particularly to a display module. Background Technology

[0002] A display module typically consists of a backlight unit and a liquid crystal unit (LCD). The backlight unit includes a light guide plate, a light source positioned on one side of the light guide plate, a reflective film positioned opposite to the bottom surface of the light guide plate, and at least two diffusion films positioned above the light guide plate. The upper diffusion film is closer to the LCD, and the lower diffusion film is closer to the light guide plate. Multiple brightness enhancement films are positioned between the upper and lower diffusion films. The LCD is used to display images and text information and is the part of the display module responsible for displaying content. The light guide plate is responsible for mixing and propagating the light emitted by the array light source into a uniform surface light source. The lower diffusion film has a large divergence angle to cover the rough appearance caused by the microstructure of the light guide plate surface. Multiple brightness enhancement films utilize the principle of microprisms to contract the large-angle light from the lower diffusion film in both horizontal and vertical directions, concentrating the light mainly within the effective field of view. Finally, the upper diffusion film achieves uniform diffusion of the light. Finally, the uniform light illuminates the LCD to display different images.

[0003] However, the transmittance of diffusion and brightening films cannot reach 100%. The more layers of these films there are in the display module, the more brightness of the light reaching the liquid crystal cells will be lost, resulting in a decrease in the brightness of the display module. However, if diffusion and brightening films are not placed between the light guide plate and the liquid crystal cells, the rough surface of the light guide plate will reduce the resolution and uniformity of the displayed image, affecting the display quality. Summary of the Invention

[0004] The purpose of this application is to provide a display module that improves its display quality.

[0005] Another objective of this application is to provide a display module that improves its display brightness.

[0006] To achieve the above objectives, this application provides a display module, including a liquid crystal unit and a backlight unit disposed on the back of the liquid crystal unit. The backlight unit includes at least one light guide plate, a light source disposed on one side of the light guide plate, and a reflective film disposed opposite to the bottom surface of the light guide plate. The feature is that at most one optical film is accommodated between the liquid crystal unit and the light guide plate, and the bottom surface of the light guide plate has a microstructure, the microstructure having a light-uniforming part and a light-emitting angle adjustment part.

[0007] In some embodiments, the distance between the liquid crystal cell and the light guide plate is T, where 0.001mm≤T≤0.2mm, and at most one optical film is accommodated between the liquid crystal cell and the light guide plate.

[0008] In some embodiments, 0.001mm≤T≤0.1mm, the light guide plate is directly opposite the liquid crystal cell.

[0009] In some embodiments, an optical film is disposed on the light-emitting side of the light guide plate. The optical film is a diffusion film, and the light-emitting surface of the light guide plate is directly opposite to the diffusion film. The diffusion film is directly opposite to the liquid crystal cell.

[0010] In some embodiments, the minimum distance between the edge of the bottom surface of the light guide plate near the light-incoming surface and the microstructure is L, where 4mm ≤ L ≤ 10mm.

[0011] In some embodiments, the X-axis, Y-axis, and Z-axis of the spatial rectangular coordinate system correspond to the width direction, length direction, and height direction of the light guide plate, respectively, and the Z-axis is perpendicular to the bottom surface of the light guide plate. The bottom surface of the light guide plate has a microstructure, the width of the microstructure along the X-axis is not greater than 10 μm, the length of the microstructure along the Y-axis is not greater than 25 μm, and the height along the Z-axis is not greater than 7.5 μm.

[0012] In some embodiments, the light emission angle adjustment unit includes angle α1 and angle α2.

[0013] In some embodiments, the microstructure has a light-facing surface facing the light-receiving surface, a backlighting surface opposite to the light-facing surface, and two connecting surfaces. The light-facing surface extends obliquely from the bottom surface in a direction away from the bottom surface, and the backlighting surface extends obliquely from the bottom surface to one end of the light-facing surface away from the bottom surface. The two connecting surfaces respectively connect the two sides of the light-facing surface and the backlighting surface. The light-facing surface is an arc surface, and the light-facing surface bends in a direction close to the backlighting surface. The light-diffusing part includes the light-facing surface.

[0014] In some embodiments, the backlight surface is an arc surface, and the backlight surface is curved in a direction away from the light-facing surface.

[0015] In some embodiments, the microstructure is recessed from the bottom surface into the light guide plate, and the light-facing surface protrudes in a direction away from the light-incoming surface; or, the microstructure protrudes from the bottom surface outward from the light guide plate, and the light-facing surface protrudes in a direction close to the light-incoming surface.

[0016] In some embodiments, the outer contour of the microstructure is a quadrilateral when viewed from above or below along the Z-axis. The quadrilateral includes a first side, a second side, a third side, and a fourth side connected in sequence. The second side is the side of the light-facing surface on the bottom surface, and the fourth side is the side of the backlighting surface on the bottom surface. Both the second side and the fourth side are arcs and have the same curvature direction.

[0017] In some embodiments, the radius of curvature of the second side is R1, the radius of curvature of the fourth side is R2, 0 < R1 ≤ 50 μm, 0 < R2 ≤ 50 μm, and / or, 0.9 ≤ R2 / R1 ≤ 1.5.

[0018] In some embodiments, the radius of curvature of the second side is R1, the radius of curvature of the fourth side is R2, the chord length of the second side is L1, the chord length of the fourth side is L2, 0 < R1 / L1 ≤ 2.78, and / or, 0 < R2 / L2 ≤ 2.78.

[0019] In some embodiments, the chord length of the second side is L1, the chord length of the fourth side is L2; L1 = L2; or, L1 ≠ L2, and the angle between the first side and the third side does not exceed 10°.

[0020] In some embodiments, the radius of curvature of the second side is R1, the radius of curvature of the fourth side is R2, the arc height of the second side is S1, the arc height of the fourth side is S2, 0 < S1 / R1 ≤ 1.5, and / or 0 < S2 / R2 ≤ 1.15.

[0021] In some embodiments, the longitudinal section of the microstructure is triangular, and the three sides of the triangle are the first intercept line formed by the light-receiving surface, the second intercept line formed by the light-emitting surface, and the base formed by connecting the ends of the first intercept line and the second intercept line. Both the first intercept line and the second intercept line are straight lines, or at least one of the first intercept line and the second intercept line is an arc.

[0022] In some embodiments, the intersection point of the first intercept line and the second intercept line is the third vertex, the perpendicular distance from the third vertex to the base is H, the distance between the foot of the perpendicular of the third vertex on the base and the first vertex on the light-receiving surface side is W1, the angle between the first intercept line and the base is α1, 22° ≤ α1 ≤ 48°, and / or 0.9 ≤ W1 / H ≤ 2.48.

[0023] In some embodiments, the intersection point of the first intercept line and the second intercept line is the third vertex, the perpendicular distance from the third vertex to the base is H, the distance between the foot of the perpendicular of the third vertex on the base and the first vertex on the light-receiving surface side is W1, the angle between the first intercept line and the base is α1, 49° ≤ α1 ≤ 56°, and / or 0.675 ≤ W1 / H ≤ 0.87.

[0024] In some embodiments, the angle between the first intercept line and the base is α1, the peak light-emitting angle of the light guide plate is β, |β| = |K × (α1 - 56)|, 1.3 ≤ K ≤ 1.6.

[0025] In some embodiments, the intersection of the first and second segments is the third vertex, the vertical distance from the third vertex to the bottom edge is H, the distance between the foot of the third vertex perpendicular to the bottom edge and the second vertex on the backlight side is W2, the angle between the second segment and the bottom edge is α2, 0.577≤W2 / H≤5.67, and / or 10°≤α2≤58°.

[0026] In some embodiments, the angle between the second slit line and the bottom edge is α2, and the light emission range of the light guide plate is positively correlated with α2.

[0027] In some embodiments, the intersection of the first and second segments is the third vertex, the distance between the foot of the third vertex perpendicular to the bottom edge and the first vertex on the light-facing side is W1, and the distance between the foot of the third vertex perpendicular to the bottom edge and the second vertex on the shaded side is W2, where 0.85 ≤ W1 / W2 ≤ 2.26.

[0028] In some embodiments, the connecting lines between the two connecting surfaces and the light-facing surface are respectively a first connecting line and a third connecting line, the connecting line between the light-facing surface and the backlight surface is a second connecting line, the connecting lines between the backlight surface and the two connecting surfaces are respectively a fourth connecting line and a fifth connecting line, at least two of the second side, the second connecting line and the fourth side are arcs, and the curvature of each arc is the same. The fourth connecting line and the fifth connecting line are straight lines or arcs, and the first connecting line and the third connecting line are straight lines or arcs.

[0029] In some embodiments, the light-diffusing section further includes at least one of the following: a curved backlight surface, a curved fifth connecting line, a curved first connecting line, a curved second connecting line, a curved third connecting line, and a curved fourth connecting line.

[0030] In some embodiments, the backlight unit includes at least two light guide plates, and each light guide plate has a separately controlled light source disposed on one side.

[0031] In some embodiments, the backlight unit includes at least two light guide plates, each light guide plate corresponding to an independently controlled light source, and the absolute values ​​of the peak light emission angle β of each light guide plate are not equal, and / or the signs of the peak light emission angle β of each light guide plate are different.

[0032] In some embodiments, the light guide plate is a type I light guide plate or a type II light guide plate, and multiple light guide plates may be the same or different.

[0033] The peak light emission angle of the type I light guide plate is β1, where |β1| ranges from 10.4° to 54.4°.

[0034] The peak light emission angle of the type II light guide plate is β2, and |β2| takes a value in the range of 0° to 11.2°.

[0035] In some embodiments, the backlight unit includes at least two of the I-type light guide plates, wherein at least one of the I-type light guide plates has a positive peak light emission angle and at least one of the I-type light guide plates has a negative peak light emission angle.

[0036] In some embodiments, the backlight unit includes at least one type I light guide plate and at least one type II light guide plate, wherein the angle between the principal ray of the type I light guide plate and the normal is greater than the angle between the principal ray of the type II light guide plate and the normal.

[0037] In some embodiments, the backlight unit includes only one light guide plate, and the light guide plate is a type II light guide plate.

[0038] Compared with the prior art, the beneficial effects of this application are as follows: the light guide plate used in the display module of this application has good transparency and low surface roughness, which has little impact on display quality. Therefore, the film layer between the light guide plate and the liquid crystal unit can be reduced, thereby improving the brightness of the display module. Attached Figure Description

[0039] Figure 1 This is an exploded view of one embodiment of the display module in this application;

[0040] Figure 2 This is an exploded view of another embodiment of the display module shown in this application;

[0041] Figure 3 This is a schematic diagram of one embodiment of the light guide plate of this application;

[0042] Figure 4A This is a schematic diagram of an embodiment of the microstructure distribution on the light guide plate of this application;

[0043] Figure 4B This is a schematic diagram of another embodiment of the microstructure distribution on the light guide plate of this application;

[0044] Figure 4C This is a schematic diagram of another embodiment of the microstructure distribution on the light guide plate of this application;

[0045] Figure 5 This is a schematic diagram of one embodiment of the microstructure on the light guide plate of this application;

[0046] Figure 6A This is a schematic diagram of an embodiment of a microstructure on a prior art light guide plate;

[0047] Figure 6B This is a brightness distribution diagram of a light guide plate using existing technology.

[0048] Figure 7A This is a cross-sectional view of one embodiment of the light guide plate of this application;

[0049] Figure 7B This is a cross-sectional view of another embodiment of the light guide plate of this application;

[0050] Figure 8 For this application to have Figure 7B Brightness distribution diagram of the microstructured light guide plate;

[0051] Figure 9 This is another schematic diagram showing the distribution of the microstructure on the light guide plate of this application;

[0052] Figure 10A This is a brightness distribution diagram of the light guide plate in one embodiment of this application;

[0053] Figure 10B This is a brightness distribution diagram of the light guide plate in another embodiment of this application;

[0054] Figure 11A This is a top view of one embodiment of the microstructure on the light guide plate of this application;

[0055] Figure 11B This is a top view of another embodiment of the microstructure on the light guide plate of this application;

[0056] Figure 12A This is a cross-sectional view of one embodiment of the microstructure on the light guide plate of this application;

[0057] Figure 12B This is a cross-sectional view of another embodiment of the microstructure on the light guide plate of this application;

[0058] Figure 13A This is a schematic diagram of one embodiment of the microstructure on the light guide plate of this application;

[0059] Figure 13B This is a schematic diagram of another embodiment of the microstructure on the light guide plate of this application;

[0060] Figure 13C This is a schematic diagram of yet another embodiment of the microstructure on the light guide plate of this application;

[0061] Figure 14A This is a brightness distribution diagram of one embodiment of the light guide plate of this application;

[0062] Figure 14B This is a brightness distribution diagram of another embodiment of the light guide plate of this application;

[0063] Figure 14C This is a brightness distribution diagram of another embodiment of the light guide plate of this application;

[0064] Figure 14D This is a light emission angle diagram of one embodiment of the light guide plate of this application;

[0065] Figure 14E This is a light emission angle diagram of another embodiment of the light guide plate of this application;

[0066] Figure 14F This is a light output brightness diagram of one embodiment of the light guide plate of this application;

[0067] Figure 14G This is a light output brightness diagram of another embodiment of the light guide plate of this application;

[0068] Figure 15A A digital photograph of an existing light guide plate;

[0069] Figure 15B A digital photograph of one embodiment of the light guide plate of this application;

[0070] Figure 16A This is a partial top view of the light guide plate of Embodiment 1 of this application;

[0071] Figure 16B This is a diagram showing the light emission angle of the light guide plate in Embodiment 1 of this application;

[0072] Figure 16C This is a light output brightness diagram of the light guide plate in Embodiment 1 of this application;

[0073] Figure 17A This is a partial top view of the light guide plate of Embodiment 2 of this application;

[0074] Figure 17B This is a diagram showing the light emission angle of the light guide plate in Embodiment 2 of this application;

[0075] Figure 17C This is a light output brightness diagram of the light guide plate in Embodiment 2 of this application;

[0076] Figure 18A This is a partial top view of the light guide plate of Embodiment 3 of this application;

[0077] Figure 18B This is a diagram showing the light emission angle of the light guide plate in Embodiment 3 of this application;

[0078] Figure 18C This is a light output brightness diagram of the light guide plate in Embodiment 3 of this application;

[0079] Figure 19A This is a schematic diagram of the first operating state of an embodiment of the backlight unit of this application.

[0080] Figure 19B This is a schematic diagram of the second operating state of an embodiment of the backlight unit of this application.

[0081] Figure 19C This is a schematic diagram of the third operating state of an embodiment of the backlight unit of this application.

[0082] Figure 19D This is a schematic diagram of the fourth operating state of an embodiment of the backlight unit of this application.

[0083] In the diagram: 10, Light source; 100, Principal ray; 101, Normal; 20, Light guide plate; 21, Light-entry surface; 22, Light-exit surface; 23, Bottom surface; 24, Microstructure; 241, Light-facing surface; 242, Backlight surface; 243, Connecting surface; 2401, First connecting line; 2402, Second connecting line; 2403, Third connecting line; 2404, Fourth connecting line; 2405, Fifth connecting line; 2411, First side; 2412, Second side; 2413, Third side; 2414, Fourth side; 25, Longitudinal section; 251, First segment; 252, Second segment; 253, Bottom edge; 2501, First vertex; 2502, Second vertex; 2503, Third vertex; 2504, Perpendicular foot; 30, Reflective film; 40, Liquid crystal unit; 50, Diffuser film; 6, Observer. Detailed Implementation

[0084] The present application will be further described below with reference to specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0085] In the description of this application, it should be noted that the directional terms such as "center", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limiting the specific protection scope of this application.

[0086] It should be noted that the terms "first," "second," etc., in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0087] The terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0088] like Figure 1 , 2 As shown, this application provides a display module, including a liquid crystal unit 40 and a backlight unit disposed on the back of the liquid crystal unit 40. The backlight unit includes a light guide plate 20, a light source 10 disposed on one side of the light guide plate 20, and a reflective film 30 disposed opposite to the bottom surface of the light guide plate 20.

[0089] In this application, the liquid crystal cell 40 and the light guide plate 20 accommodate at most one optical film. The bottom surface of the light guide plate 20 has a microstructure 24, which includes a light homogenizing section and a light emission angle adjustment section. The light homogenizing section ensures uniform light emission from the light guide plate 20, while the light emission angle adjustment section primarily affects the peak light emission angle of the light guide plate 20. When the microstructure 24 has both a light homogenizing section and a light emission angle adjustment section, the display module can eliminate the need for redundant diffusion films and brightness enhancement films, requiring only a single diffusion film. This helps to reduce the size and cost of the display module. Furthermore, the reduced number of optical film layers improves the brightness of the emitted light from the display module.

[0090] Furthermore, the distance between the liquid crystal unit 40 and the light guide plate 20 is T, where 0.001mm ≤ T ≤ 0.2mm. At most one optical film is provided between the liquid crystal unit 40 and the light guide plate 20. When no optical film is provided, adhesive may also be provided between them for connection, thus a certain gap still exists between the liquid crystal unit 40 and the light guide plate 20.

[0091] It is worth mentioning that the light emission angle adjustment unit includes angles α1 and α2. Angle α1 is used to adjust the light emission angle (i.e., peak emission angle) of the main light beam from the light guide plate 20, allowing the displayed image of the display module to be seen by an observer in a specific direction as needed. Angle α2 is used to adjust the light emission range of the light guide plate 20, ensuring that an observer in a specific direction can still see the displayed image even if that direction is shifted within a certain range. This gives the light guide plate 20 the function of adjusting the light emission angle, allowing it to adjust light in multiple ways, replacing the brightness enhancement film in the prior art, and improving its functionality. Those skilled in the art will understand that a single brightness enhancement film in the prior art can only adjust the light angle in one of the X or Y directions, and only provides light convergence.

[0092] like Figure 3The diagram shown is a schematic representation of an embodiment of the light guide plate 20 of this application. The light guide plate 20 includes a light-inlet surface 21, a light-outlet surface 22, a bottom surface 23, and a plurality of microstructures 24. The light-outlet surface 22 and the bottom surface 23 are disposed opposite to each other, the light-inlet surface 21 connects the light-outlet surface 22 and the bottom surface 23, and the microstructures 24 are disposed on the bottom surface 23. Light emitted from the light source 10 enters through the light-inlet surface 21, is diffused by the microstructures 24 on the bottom surface 23, and then exits through the light-outlet surface 22. It is worth mentioning that... Figure 3 The X-axis, Y-axis, and Z-axis of the medium-space rectangular coordinate system correspond to the width, length, and height directions of the light guide plate 20 and the microstructure 24, respectively. The X-axis is perpendicular to the light-inlet surface 21, the Y-axis is parallel to the light-inlet surface 21, and the Z-axis is perpendicular to the bottom surface 23.

[0093] Furthermore, the width of the microstructure 24 along the X-axis is no greater than 10 μm, the length of the microstructure 24 along the Y-axis is no greater than 25 μm, and the height along the Z-axis is no greater than 7.5 μm. The small size of the microstructure 24 in this application results in a smoother surface and better transparency of the light guide plate 20. Its appearance has no significant impact on the display of the liquid crystal unit 40, eliminating the need for the diffusion film and brightness enhancement film between the light guide plate 20 and the liquid crystal unit 40. This allows more light emitted from the backlight unit to reach the liquid crystal unit 40, thereby improving display brightness. In addition, the smaller size of the microstructure 24 allows for greater freedom in the arrangement of multiple microstructures 24, enabling more adjustments and improving performance in terms of appearance, uniformity, and brightness.

[0094] There is a contradiction in the existing technology: on the one hand, it is necessary to maximize the use of diffusion films and brightness enhancement films to improve the light emission uniformity of the backlight unit; on the other hand, it is necessary to minimize the use of diffusion films and brightness enhancement films to reduce brightness loss. This application improves the microstructure 24 of the light guide plate 20, making the size of the microstructure 24 significantly smaller than that of conventional microstructures (the length or width of a conventional prismatic microstructure is typically around 40 μm), thereby improving the transparency of the light guide plate 20. Figure 15A and 15B As shown, Figure 15A This is a light guide plate in the prior art, which is opaque or semi-transparent. Figure 15B The light guide plate of this application has significantly better transparency. This improvement allows the backlight unit to maintain display quality even after the diffusion film and brightness enhancement film are removed, without the surface roughness of the light guide plate affecting the display quality, and also provides excellent light emission uniformity.

[0095] The width of microstructure 24 along the X-axis is no greater than 10 μm, for example, 9 μm, 8 μm, 7 μm, 6 μm, 5 μm, 4 μm, 3 μm, etc. The length of microstructure 24 along the Y-axis is no greater than 25 μm, for example, 24 μm, 23 μm, 22 μm, 21 μm, 20 μm, 19 μm, 18 μm, 17 μm, 16 μm, 15 μm, 10 μm, etc. The height of microstructure 24 along the Z-axis is no greater than 7.5 μm, for example, 7 μm, 6.5 μm, 6 μm, 5.5 μm, 5 μm, 4.5 μm, 4 μm, 3.5 μm, 3 μm, etc.

[0096] like Figure 1 As shown, in the first embodiment, the light guide plate 20 in the display module is directly opposite to the liquid crystal unit 40. This "directly opposite" arrangement means that no other optical film layers are provided between the light guide plate 20 and the liquid crystal unit 40, although an adhesive layer for connection is not excluded. The light emitted from the light source 10 in the display module exits from the light guide plate 20 and directly enters the liquid crystal unit 40. Furthermore, a reflective film 30 is provided on the side of the light guide plate 20 near the bottom surface 23, suitable for reflecting the light emitted to the bottom of the light guide plate 20 back into the light guide plate 20 to reduce light loss. Since no other film layers are provided between the light guide plate 20 and the liquid crystal unit 40, the loss of brightness can be minimized. Furthermore, reducing the number of film layers also helps to lower the cost of the display module and makes the assembly of the display module more convenient.

[0097] like Figure 2 As shown, in the second embodiment, a diffusion film 50 is provided on the light-emitting side of the light guide plate 20. The light-emitting surface 22 is directly opposite one side of the diffusion film 50, and the other side of the diffusion film 50 is directly opposite the liquid crystal unit 40. That is, after the light is emitted from the light guide plate 20, it first passes through the diffusion film 50 for uniform diffusion, and then enters the liquid crystal unit 40 for display. Adding a diffusion film 50 helps to improve the resolution and uniformity of the final displayed image. Moreover, adding only one diffusion film 50 has little impact on the brightness.

[0098] In some embodiments, the distance between the liquid crystal cell 40 and the light guide plate 20 is T, where 0.001mm ≤ T ≤ 0.2mm. Using the light guide plate 20 of this application reduces the number of optical films used, thereby reducing the gap between the liquid crystal cell 40 and the light guide plate 20, and consequently reducing the overall size of the display module. Furthermore, at most one optical film is accommodated between the liquid crystal cell 40 and the light guide plate 20; preferably, the optical film is a diffusion film.

[0099] There are multiple ways to arrange the microstructures 24 on the light guide plate 20. By controlling the density of the distribution of the microstructures 24, the emission angle and range of the light can be precisely adjusted to obtain different light emission effects required under different conditions.

[0100] In some embodiments, the microstructures 24 on the light guide plate 20 are arranged uniformly, such as... Figure 4A As shown, multiple microstructures 24 can more effectively disrupt the total internal reflection phenomenon inside the light guide plate 20, increase the light divergence of the light source 10, eliminate obvious dark areas between parallel light sources, thereby improving the uniformity of illumination and enhancing the display quality of the display module.

[0101] In some embodiments, the microstructures 24 on the light guide plate 20 are arranged sparsely near the light source 10 and densely away from the light source 10, such as... Figure 4B As shown, when the light emitted by the light source 10 propagates within the light guide plate 20, the further away from the light source 10, the lower the light energy. In order to reduce light loss, the far-light source area with lower energy requires more microstructures 24 to reflect the light compared to the near-light source area, so as to reflect as much light as possible toward the light-emitting surface 22, thereby improving the light output brightness and uniformity of the light guide plate 20.

[0102] In some embodiments, the microstructures 24 on the light guide plate 20 are arranged in a locally dense and locally sparse manner, such as... Figure 4C As shown. This design helps to achieve fine backlight control, especially in edge-lit backlight units. This design can retain the advantage of the small thickness of edge-lit backlight units, while overcoming the problem of only being able to adjust the backlight in rows or columns.

[0103] This application obtains a light guide plate 20 with better transparency by reducing the size of the microstructure 24, making it possible to eliminate the diffusion film 50 and the brightness enhancement film. Furthermore, this application also improves the surface shape of the microstructure 24 to enhance the ability of the microstructure 24 to control light, so as to ensure that the backlight unit still has uniform light output after the diffusion film 50 is eliminated.

[0104] Specifically, such as Figure 5 As shown, the microstructure 24 of this application has a light-facing surface 241 facing the light-inlet surface 21 and a backlight surface 242 opposite to the light-facing surface 241. The microstructure 24 also has two connecting surfaces 243, which connect the two sides of the light-facing surface 241 and the backlight surface 242, respectively. The light entering the light guide plate 20 from the light-inlet surface 21 is mainly reflected by the light-facing surface 241 and emitted from the light-exit surface 22 of the light guide plate 20. The light-facing surface 241 extends obliquely from the bottom surface 23 in a direction away from the bottom surface 23, and the backlight surface 242 extends obliquely from the bottom surface 23 to the end of the light-facing surface 241 away from the bottom surface 23.

[0105] The light-facing surface 241 is curved, and it bends towards the backlight surface 242. The curved light-facing surface 241 can better disperse light and improve light uniformity; the brightness distribution is shown in embodiments 1, 2, and 3 of the light guide plate. In other embodiments, the microstructure 24 is a triangle without a specific curvature, such as... Figure 6A As shown, due to the excessively concentrated light emission angle, the brightness of the emitted light varies at different positions on the light-emitting surface 22, especially in the area near the light source, where bright and dark stripes appear, resulting in poor uniformity. Figure 6B As shown. In addition, this application can adjust the light-emitting angle of the light guide plate 20 by adjusting the tilt angle of the light-facing surface 241, so that the main light beam is emitted at the required angle to ensure high brightness.

[0106] Preferably, the backlight surface 242 is also curved, and the backlight surface 242 bends away from the light-facing surface 241. For example Figure 5 As shown, the shape of the entire microstructure 24 resembles a triangular prism with two sides curved to one side. This shape allows for adjustment of the angle in the vertical direction of light propagation (i.e., the direction of the LED arrangement or the Y-axis direction), which is beneficial for light diffusion between the LEDs and ensures the overall uniformity of light output from the light guide plate 20. Furthermore, the arc-shaped backlight surface 242 can further adjust the light, allowing it to be emitted as a wide or narrow beam as needed. Of course, in some embodiments, the backlight surface 242 can also be planar.

[0107] The microstructure 24 of this application can be recessed from the bottom surface 23 into the light guide plate 20, such as... Figure 7A As shown, the light-facing surface 241 is close to the light-inlet surface 21, and the backlight surface 242 is away from the light-inlet surface 21. Both the light-facing surface 241 and the backlight surface 242 are curved in a direction away from the light-inlet surface 21. The recessed microstructure 24 helps to eliminate obvious dark areas between light sources, increases the degree of light divergence, and can further improve the light output efficiency and illuminance uniformity of the light guide plate 20. The brightness distribution is referenced to light guide plate embodiments 1, 2, and 3. Compared with the microstructure 24 protruding from the bottom surface 23, the recessed microstructure 24 in the light guide plate 20 can achieve higher light efficiency and make the light output uniformity of the light guide plate 20 better.

[0108] The microstructure 24 in this application can also protrude from the bottom surface 23 outwards from the light guide plate 20, such as... Figure 7BAs shown, the backlight surface 242 is close to the light-inlet surface 21, and the front light surface 241 is far from the light-inlet surface 21. The front light surface 241 and the backlight surface 242 are bent towards the light-inlet surface 21. When the microstructure 24 is protruding, the light emitted by the light source 10 first directly reaches the front light surface 241. Most of the light is reflected by the front light surface 241 and then exits the light guide plate 20 from the light-outlet surface 22. Some of the light undergoes multiple refractions or reflections within the light guide plate 20 and is reflected by the backlight surface 242 towards the light-outlet surface 22. Of course, some of the light is refracted by the front light surface 241 to reach the backlight surface 242 of the adjacent microstructure 24, and then refracted out by the backlight surface 242. However, because the path of light to the front light surface 241 of the microstructure 24 becomes longer, the light reflection ability of the microstructure 24 farther from the light source 10 is relatively poor. Therefore, its brightness distribution diagram shows that the side closer to the light source 10 is brighter, and the side farther from the light source 10 is weaker, as shown in the figure. Figure 8 As shown. To address the issue of poor uniformity of the light source 10 when the microstructure 24 is protruding on the bottom surface 23 of the light guide plate 20, the distribution density of the microstructure 24 on the side closer to the light source 10 can be reduced, while the distribution density on the side farther from the light source 10 can be increased. This achieves a light guide plate 20 module with high uniformity and high luminous efficiency. Furthermore, the protruding microstructure 24 also serves to prevent adhesion and top-whitening between the light guide plate 20 and other films.

[0109] In some embodiments, such as Figure 9 As shown, the minimum distance between the edge of the bottom surface 23 near the light-incoming surface 21 and the microstructure 24 is L, 4mm ≤ L ≤ 10mm, for example, it can be 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, etc. For example, if the light source 10 comes from an LED, due to the spacing between the LED beads, there will be gaps in the light emitted by different beads, requiring a certain distance for light mixing. When there is a certain blank area between the microstructure 24 and the edge of the light guide plate 20, the light from different LED beads can be fully mixed in the blank area, and the light reaching the microstructure 24 is more uniform. Figure 10A As shown, when 4mm≤L≤10mm, the brightness uniformity of the light emitted by the light guide plate 20 is good; when L is less than 4mm, as... Figure 10B As shown, the emitted light from the left side of the light guide plate 20 exhibits obvious uneven brightness, resulting in poor brightness uniformity. Furthermore, if L exceeds 10mm, the microstructure 24 is too far from the light source, meaning that a larger area of ​​the light guide plate 20 near the light source lacks a microstructure. This prevents light from escaping from the area near the light source, creating a dark area.

[0110] In some embodiments, 8mm≤L≤10mm. The microstructure 24 is farther from the edge of the light guide plate 20, resulting in a larger blank area, more complete light mixing, and more uniform brightness of the emitted light.

[0111] In some embodiments, Figure 11A , Figure 11B This is a schematic diagram of the outer contour of the microstructure 24 viewed from above or below the light-emitting surface 22. The top-view outer contour of the microstructure 24 is quadrilateral, comprising a first side 2411, a second side 2412, a third side 2413, and a fourth side 2414 connected sequentially. This quadrilateral corresponds to the projection shape of the microstructure 24 along the Z-axis onto the bottom surface 23. The first side 2411 and the third side 2413 correspond to the sides of the two connecting surfaces 243 on the bottom surface 23, the second side 2412 corresponds to the side of the light-facing surface 241 on the bottom surface 23, and the fourth side 2414 corresponds to the side of the backlight surface 242 on the bottom surface 23. The second side 2412 is an arc, and its radius of curvature is denoted as R1. The fourth side 2414 is an arc, and its radius of curvature is denoted as R2. The second side 2412 and the fourth side 2414 have the same curvature direction, and the top view of the outer contour of the microstructure 24 is close to a crescent shape. Furthermore, the first side 2411 and the third side 2413 are both straight lines. In some other embodiments, the fourth side 2414 can also be a straight line (e.g., when the backlight surface 242 is a plane), and the first side 2411 and the third side 2413 can also be curved lines. The dashed line connecting the two ends of the second side 2412 in the figure represents the chord of the second side 2412, with a chord length denoted as L1. The dashed line connecting the two ends of the fourth side 2414 represents the chord of the fourth side 2414, with a chord length denoted as L2. The arc height S1 of the second side 2412 is the maximum distance along the X-axis between the chord of the second side 2412 and the second side 2412. The arc height S2 of the fourth side 2414 is the maximum distance along the X-axis between the chord of the fourth side 2414 and the fourth side 2414.

[0112] Figure 12A This is a schematic diagram of the longitudinal section 25 of the microstructure 24 on the light guide plate. The longitudinal section 25 is a cross-section perpendicular to the Y-axis. The longitudinal section of the microstructure 24 is triangular, and the three sides of the triangle are the first segment 251 of the light-facing surface 241 on the cross-section, the second segment 252 of the backlight surface 242 on the cross-section, and the base 253 formed by connecting the ends of the two segments. It is understood that the triangle referred to in this application is not limited to a geometrically standard triangle, but also includes shapes that approximate a triangle, such as a rounded triangle or a triangle with at least one curved side, for example... Figure 12BThe shape shown. When the triangle in the longitudinal section is a rounded triangle, it means that there is a smooth transition between the light-facing surface 241 and the backlight surface 242, and there is also a smooth transition between the light-facing surface 241 and the backlight surface 242 and the bottom surface 23. This smooth transition microstructure 24 helps to reduce the deformation of the light guide plate 20 due to thermal stress during use, thereby extending the service life of the light guide plate 20. The intersection of the base 253 and the first segment 251 is the first vertex 2501; the intersection of the base 253 and the second segment 252 is the second vertex 2502; the intersection of the first segment 251 and the second segment 252 is the third vertex 2503; the distance between the third vertex 2503 and its perpendicular foot 2504 on the base 253 is H; the distance between the first vertex 2501 and the second vertex 2502 is W; the distance between the first vertex 2501 and the perpendicular foot 2504 is W1; the distance between the second vertex 2502 and the perpendicular foot 2504 is W2; the interior angle at the first vertex 2501 is α1; and the interior angle at the second vertex 2502 is α2. It is worth noting that when the microstructure 24 protrudes from the base 23, its cross-sectional shape is the same as when it is concave, which will not be elaborated further here.

[0113] like Figures 13A-13C As shown, the line connecting the light-facing surface 241 and the bottom surface 23 is the second side 2412; the line connecting the light-facing surface 241 and the backlight surface 242 is the second connecting line 2402; the line connecting the backlight surface 242 and the bottom surface 23 is the fourth side 2414; the lines connecting the backlight surface 242 and the two connecting surfaces 243 are the fourth connecting line 2404 and the fifth connecting line 2405, respectively; the lines connecting the two connecting surfaces 243 and the light-facing surface 241 are the first connecting line 2401 and the third connecting line 2403, respectively; and the lines connecting the two connecting surfaces 243 and the bottom surface 23 are the first side 2411 and the third side 2413, respectively.

[0114] In such Figure 13A In the illustrated embodiment, the second side 2412 and the fourth side 2414 of the microstructure 24 are arcs, and the first connecting line 2401, the second connecting line 2402, the third connecting line 2403, the fourth connecting line 2404, and the fifth connecting line 2405 are straight lines. That is, the light-facing surface 241 is curved at the end near the bottom surface 23, and gradually becomes flat as it extends away from the bottom surface 23. The back-lighting surface 242 is flat, so the second connecting line 2402 formed by the intersection of the light-facing surface 241 and the back-lighting surface 242 is a straight line. The two connecting surfaces 243 of the microstructure 24 are flat. The light will propagate in different directions along the curvature of the light-facing surface 241, which can make the light emitted from the light-facing surface 241 diffuse more evenly.

[0115] In such Figure 13BIn the embodiment shown, the second side 2412, the fourth side 2414, and the second connecting line 2402 of the microstructure 24 are all arcs, while the first connecting line 2401, the third connecting line 2403, the fourth connecting line 2404, and the fifth connecting line 2405 are straight lines. That is, the light-facing surface 241 and the back-facing surface 242 are both single curved surfaces, and the two connecting surfaces 243 of the microstructure 24 are planes. Light will propagate in different directions along the curvature of the light-facing surface 241 and the back-facing surface 242, which can make the light emitted from the light-facing surface 241 and the back-facing surface 242 diffuse more evenly.

[0116] In such Figure 13C In the illustrated embodiment, the second side 2412, the fourth side 2414, the second connecting line 2402, the fourth connecting line 2404, and the fifth connecting line 2405 of the microstructure 24 are all curved lines, while the first side 2411, the third side 2413, the first connecting line 2401, and the third connecting line 2403 are straight lines. The light-facing surface 241 is a single curved surface, the backlight surface 242 is a hyperboloid, and the two connecting surfaces 243 of the microstructure 24 are planar. In some embodiments, the first side 2411, the third side 2413, the first connecting line 2401, and the third connecting line 2403 may also be curved lines.

[0117] In some embodiments, the microstructure 24 further has the following characteristics: the distance between each point of the second side 2412 and the fourth side 2414 along the X-axis does not exceed 10 μm, or the length W of the bottom side 253 is ≤ 10 μm; the chord lengths L1 and L2 of the second side 2412 and the fourth side 2414 are ≤ 25 μm and ≤ 25 μm, preferably, L1 ≤ 20 μm and L2 ≤ 20 μm. The small size of the microstructure 24 can effectively improve the transparency of the light guide plate 20, resulting in a substantially transparent light guide plate 20. In addition, since the microstructure 24 of this application is small in size, the distribution density of the microstructure 24 on the bottom surface 23 can be increased, and the combination diversity of the microstructure 4 on the bottom surface 3 can be increased, making the means of adjusting light more abundant, resulting in higher light propagation efficiency and significantly increasing the overall brightness of the light guide plate 20.

[0118] In some embodiments, the microstructure 24 has the following characteristics: 0 < R1 ≤ 50 μm, 0 < R2 ≤ 50 μm, and / or, 0.9 ≤ R2 / R1 ≤ 1.5. More preferably, 1 ≤ R2 / R1 ≤ 1.3. By adjusting the curvature of the light-facing surface 241 and the backlight surface 242 of the microstructure 24, the angle of light propagation along the Y-axis can be adjusted, reducing the uneven distribution of light along the Y-axis, which is beneficial to improving the light output uniformity of the light guide plate 20. Thus, a uniform brightness distribution can be achieved with a single layer of the light guide plate 20, and its light output brightness distribution diagram can be referenced. Figure 14AWhen the radius of curvature R1 of the second side 2412 of the microstructure 24 is greater than 50 μm, it means that the curvature of the light-facing surface 241 and the back-facing surface 242 is smaller and closer to a plane. At this time, more obvious bright and dark stripes are likely to appear near the light source 10, such as... Figure 14B As shown, this reduces the uniformity of light output; or when R2 / R1 < 0.9 or R2 / R1 > 1.5, it means that the curvature of the light-facing surface 241 and the backlight surface 242 is significantly different, and noticeable bright and dark stripes are also likely to appear near the light source 10, such as... Figure 14C As shown.

[0119] This application can obtain the desired light emission angle by adjusting the angle α1, thereby giving the light guide plate 20 good light emission directionality. For example, it can obtain a type I light guide plate with a larger peak light emission angle β, or a type II light guide plate with a smaller peak light emission angle β.

[0120] Specifically, the microstructure 24 of the Type I light guide plate 20 has the following characteristics: 22°≤α1≤48°, and / or, 0.9≤W1 / H≤2.48. Because the Type I light guide plate 20 has a large light emission angle, several Type I light guide plates 20 with different light emission angles can be combined for use in a display device, allowing observers in different positions to clearly see the displayed content, achieving a shared display effect.

[0121] The microstructure 24 of the Type II light guide plate has the following characteristics: 49°≤α1≤56°, and / or, 0.675≤W1 / H≤0.87. Because the Type II light guide plate 20 has a smaller light emission angle, display devices with the Type II light guide plate 20 can only provide a clear display to an observer at a specific location. The Type II light guide plate 20 allows for individual viewing from a single location, emphasizing the protection of user privacy.

[0122] It is worth mentioning that in some embodiments of this application, the backlight unit does not have a thin film such as a brightness enhancement film to deflect the emitted light, and the emission angle of the peak emitted light of the single light guide plate 20 is preferably controlled at around 0°, that is, the light guide plate 20 is a type II light guide plate.

[0123] Furthermore, the relationship between the peak light emission angle β and α1 of the light guide plate 20 is: |β|=|K×(α1-56)|, 1.3≤K≤1.6, where K can be, for example, 1.3, 1.35, 1.4, 1.44, 1.45, 1.46, 1.47, 1.48, 1.49, 1.5, 1.55, 1.6, etc. It is worth noting that when the light source is located on the right side of the light guide plate, β=-K×(α1-56); when the light source is located on the left side of the light guide plate, β=K×(α1-56). For Type I light guide plates, the smaller α1 is, the larger |β| is. This means that when a Type I light guide plate is applied to a display device, the smaller α1 is, the clearer the display content will be for observers further away from the display device, while observers directly in front of the display device will have difficulty seeing the display content. For Type II light guide plates, the larger α1 is, the smaller β is. When a Type II light guide plate is applied to a display device, the larger α1 is, the clearer the displayed content will be for an observer directly in front of the display device, while it will be difficult for an observer far from the display device to see the displayed content. It is worth mentioning that the peak light emission angle β of the light guide plate is the angle between the light ray at the position of maximum light emission (i.e., the principal ray) and the surface normal of the light emission surface.

[0124] When light is refracted at the light-facing surface 241 of the microstructure 24 and reaches the backlight surface 242, it undergoes secondary refraction at the backlight surface 242. Therefore, the surface features of the backlight surface 242 also affect the light emission angle, which can be used to increase the emission angle range θ, where θ is the angle between rays whose brightness value is 50% of the peak value. In some embodiments, the microstructure 24 has the following characteristics: 0.577≤W2 / H≤5.67, and / or, 10°≤α2≤58°. Further, θ and α2 are positively correlated. A larger θ can achieve multi-viewpoint light emission from the light guide plate 20, while a smaller θ can achieve single-viewpoint high-brightness light emission from the light guide plate 20. By adjusting the far-beam angle α2, the viewing needs of different display devices can be met. Figure 14D As shown, when α2 is small, the light guide plate has a narrow light emission angle range; the black arrows in the figure indicate the light emission angle range. Figure 14E As shown, when α2 is large, the light guide plate has a wider range of light emission angles. The black arrows in the figure indicate the range of light emission angles. It is worth mentioning that... Figure 14D and Figure 14E The only difference between the light guide plates is the angle between the backlight surface 242 and the bottom surface 23 of the microstructure 24.

[0125] In some embodiments, the microstructure 24 has the following characteristics: 0 < R1 / L1 ≤ 2.78, 0 < R2 / L2 ≤ 2.78, 0.85 ≤ W1 / W2 ≤ 2.26. The ratio of R to L is used to characterize the bending degree of the microstructure 24, which mainly affects the light-emitting uniformity of the light guide plate 20. W1 and W2 are used to characterize the relative relationship of the inclination degrees of the light-facing surface 241 and the backlight surface 242 of the microstructure 24, which mainly affects the light-emitting angle and the width range of the light guide plate 20. By defining the foregoing parameters of the microstructure 24, it is more conducive to obtaining a light guide plate 20 with uniform light emission, high brightness, and wide viewing angle light emission.

[0126] In some embodiments, the microstructure 24 has the following characteristics: 0 < S1 / R1 ≤ 1.5, 0 < S2 / R2 ≤ 1.15. By controlling the ratio relationship between the arc height and the curvature radius of the arc, the regulation of the surface shape and size of the microstructure 24 is achieved. When the surface shape characteristics of the microstructure 24 satisfy the foregoing relational expressions, the light-emitting uniformity of the light guide plate 20 is better. In addition, by controlling the size of the microstructure 24, the microstructure 24 is made to have processability and is conducive to improving the surface permeability of the light guide plate 20.

[0127] In some embodiments, the microstructure 24 has the following characteristics: the included angle between the two connecting surfaces 243 does not exceed 10°; preferably, the included angle between the two connecting surfaces 243 does not exceed 5°; more preferably, the two connecting surfaces 243 are parallel to each other. Or rather, the included angle between the first side 2411 and the third side 2413 does not exceed 10°; preferably, the included angle between the first side 2411 and the third side 2413 does not exceed 5°; more preferably, the first side 2411 and the third side 2413 are parallel to each other, and at this time L1 = L2. This characteristic of the microstructure 24 is conducive to improving the light-emitting brightness of the light guide plate 20. When the included angle between the first side 2411 and the third side 2413 of the microstructure is greater than 10°, the light-emitting brightness of the light guide plate 20 is poor. Figure 14F and Figure 14G are respectively schematic diagrams of the brightness of light guide plates with different microstructures 24, where Figure 14F the first side 401 and the third side 403 of the microstructure are parallel to each other, Figure 14F the top view of the microstructure 24 of the light guide plate in Figure 11A is as shown in Figure 14G the top view of the microstructure 24 of the light guide plate in Figure 11B is as shown in

[0128] In some embodiments, the microstructure 24 further has the following characteristics: both the first segment 251 and the second segment 252 are straight lines. That is, the light-facing surface 241 and the back-facing surface 242 of the microstructure 24 are single-curved surfaces. Of course, in other embodiments, the first segment 251 and / or the second segment 252 are arcs, that is, the light-facing surface 241 and / or the back-facing surface 242 are hyperboloids.

[0129] In some embodiments, the light-diffusing section includes a light-facing surface. Further, the light-diffusing section also includes at least one of a curved backlight surface 242, a curved fifth connecting line 2405, a curved first connecting line 2401, a curved second connecting line 2402, a curved third connecting line 2403, and a curved fourth connecting line 2404.

[0130] The following provides specific embodiments of the light guide plate.

[0131]

Example 1

[0132] A light guide plate with a size of 301mm × 139mm is provided, and microstructures 24 are set on its bottom surface 23. A top view of part of the plate is shown below. Figure 16A As shown, the microstructure 24 is recessed inside the light guide plate. Both the light-facing surface 241 and the backlight surface 242 of the microstructure 24 are curved surfaces curving away from the light-receiving surface 21. The two connecting surfaces 243 of the microstructure 24 are parallel planes. The microstructure 24 has L1 = L2 = 18 μm, the lengths of the first side 2401 and the third side 2403 are both 8.585 μm, the height of the microstructure 24 profile is H = 3.3978 μm, α1 = 29.2°, α2 = 53.6°, R1 = 13.2 μm, R2 = 15.8 μm, and R2 / R1 = 1.197.

[0133] The light guide plate in Example 1 is a Type I light guide plate, with an outgoing light angle of 30° in its region, as shown in Figure 16B. The entire light guide plate achieves a final effect of high brightness and uniform light output, and its brightness distribution is as follows. Figure 16C As shown. When the light guide plate provided in Embodiment 1 is applied to a display device, an observer directly in front of the light guide plate receives less light and cannot clearly see the display content. Only within a viewing angle tilt of approximately +30° can the observer receive more light and clearly see the display content. At a position of -30°, the display content is also unclear. In practical use, the two light guide plates of Embodiment 1 can be used in combination. When the light source corresponding to one of the light guide plates emits light, the observer at the tilt position corresponding to that light guide plate can clearly see the display content. When the light sources corresponding to both light guide plates emit light, the observers at two different positions can clearly see the display content.

[0134]

Example 2

[0135] The difference between Example 2 and Example 1 is that the lengths of the first side 2401 and the third side 2403 of the microstructure 24 are both 5 μm, α1 = 53.7°, α2 = 53.6°, R1 = 12.5 μm, R2 = 15.8 μm, and R2 / R1 = 1.264.

[0136] The light guide plate in Example 2 is a Type II light guide plate. Figure 17A This is a top view of a portion of the area, where the emitted light angle is 0°. The distribution diagram is shown in Figure 17B. The light guide plate achieves the final effect of high brightness and uniform light emission, and its brightness distribution is as follows. Figure 17C As shown. When the light guide plate provided in Embodiment 2 is applied to a display device, the observer located directly in front of the light guide plate receives more light and can see the display content clearly, while the observers in other directions receive less light and cannot see the display content clearly.

[0137]

Example 3

[0138] The difference between Example 3 and Example 1 is that the lengths of the first side 2401 and the third side 2403 of the microstructure 24 are both 7.66 μm, α1 = 29.2°, α2 = 65°, R1 = 13.2 μm, R2 = 16.8 μm, and R2 / R1 = 1.273.

[0139] The light guide plate in Example 3 is a Type I light guide plate, such as... Figure 18A As shown, the peak emission angle of the main ray from the light guide plate in Example 3 is approximately 38°, and the light emission range is >38°±a. The value of 'a' is defined by the ray at 50% of the peak energy, and is adjusted by α2. Figure 18B As shown, the light guide plate achieves the final effect of high brightness and uniform light output, and its brightness distribution is as follows. Figure 18C As shown.

[0140] Preferably, the backlight unit of this application includes at least two light guide plates 20, and each light guide plate 20 corresponds to an independently controlled light source 10. The absolute values ​​of the peak light emission angle β of each light guide plate 20 are not equal, and / or the signs of the peak light emission angle β of each light guide plate 20 are different. By combining light guide plates 20 with different light emission angles, the switching of different display modes of the display module can be realized.

[0141] For example, when the peak light emission angle β of the two light guide plates 20 has the same sign but different values, it means that clear display content can be obtained at two observation positions on the same side of the normal; when the peak light emission angle β of the two light guide plates 20 has different signs, it means that clear display content can be obtained at two observation positions on different sides of the normal.

[0142] Figures 19A-19DThis is a schematic diagram of a specific embodiment of a backlight unit, showing that the backlight unit includes two light guide plates. The two light guide plates are stacked one above the other, with the peak light emission angle of the first light guide plate being β1 and the peak light emission angle of the second light guide plate being β2. |β1|≠|β2|, and β1 and β2 have the same sign, meaning that the principal rays 100 of the two light guide plates are located on the same side of the normal 101. When only the light source 10 opposite to the first light guide plate is turned on, the observer 6 can clearly see the displayed content in the β1 direction, such as... Figure 19A As shown; when only the light source 10 opposite to the second light guide plate is turned on, the observer 6 can clearly see the displayed content in the β2 direction, as shown. Figure 19B As shown; when the light sources 10 opposite to the two light guide plates are turned on simultaneously, the observer 6 can clearly see the displayed content in the β1 and β2 directions, as shown. Figure 19C As shown; when the direction of the first light guide plate is rotated 180°, its peak light emission angle is -β1, and the peak light emission angle of the second light guide plate is β2. That is, the principal rays 100 of the two light guide plates are located on different sides of the normal 101. At this time, the light sources 10 corresponding to the two light guide plates are also located on different sides. When the two light sources 10 are turned on simultaneously, the observer 6 can clearly see the displayed content in the -β1 and β2 directions, as shown. Figure 19D As shown.

[0143] In one application example, the display module provided in this application can be applied to a car center console screen. The driver's seat and the passenger seat have different angles relative to the display screen. The peak light emission angle of one light guide plate can be set to face the driver's seat, and the peak light emission angle of the other light guide plate can be set to face the passenger seat. When it is desired that only one position can see the screen content clearly, only the light source of the corresponding light guide plate on that side can be turned on. When it is desired that both positions can see the screen content clearly, the light sources of both light guide plates can be turned on.

[0144] When the display module is positioned between the driver's seat and the passenger seat, the driver's seat and the passenger seat are located to the left and right of the display module, respectively. At this time, two Type I light guide plates can be selected, with the two Type I light guide plates set in opposite directions, so that the peak light output angle of one light guide plate is for the driver's seat and the peak light output angle of the other light guide plate is for the passenger seat.

[0145] When the display module is positioned directly in front of the driver's seat, the passenger seat is located to the side of the display module. In this case, one type I light guide plate and one type II light guide plate can be selected. The peak light output angle of the type II light guide plate is for the driver's seat, and the peak light output angle of the type I light guide plate is for the passenger seat.

[0146] When the display module is positioned directly in front of the passenger seat, the driver's seat is located to the side of the display module. In this case, one type I light guide plate and one type II light guide plate can be selected. The peak light output angle of the type II light guide plate is for the passenger seat position, and the peak light output angle of the type I light guide plate is for the driver's seat position.

[0147] In some embodiments, the peak light emission angle of the type I light guide plate is β1, where |β1| is taken in the range of 10.4° to 54.4°, and the peak light emission angle of the type II light guide plate is β2, where |β2| is taken in the range of 0° to 11.2°.

[0148] In some embodiments, the backlight unit includes at least two I-shaped light guide plates, wherein at least one of the I-shaped light guide plates has a positive peak light emission angle, and at least one of the I-shaped light guide plates has a negative peak light emission angle. Preferably, the peak light emission angle β1 of at least one I-shaped light guide plate is between 15° and 50°, and the peak light emission angle β1 of at least one I-shaped light guide plate is between -15° and -50°. More preferably, the peak light emission angle β1 of at least one I-shaped light guide plate is between 20° and 40°, and the peak light emission angle β1 of at least one I-shaped light guide plate is between -20° and -40°.

[0149] In some embodiments, the backlight unit includes at least one type I light guide plate and at least one type II light guide plate, wherein the angle between the principal ray of the type I light guide plate and the normal is greater than the angle between the principal ray of the type II light guide plate and the normal. Preferably, the peak light emission angle β2 of at least one type II light guide plate is -10° to 10°, and the peak light emission angle β2 of at least one other type I light guide plate is 15° to 50° or -15° to -50°. More preferably, the peak light emission angle β2 of at least one type II light guide plate is -5° to 5°, and the peak light emission angle β2 of at least one other type I light guide plate is 20° to 40° or -20° to -40°.

[0150] The basic principles, main features, and advantages of this application have been described above. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely the principles of this application. Various changes and modifications can be made to this application without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection claimed by this application is defined by the appended claims and their equivalents.

Claims

1. A display module, comprising a liquid crystal unit and a backlight unit disposed on the back side of the liquid crystal unit, the backlight unit comprising at least one light guide plate, a light source disposed on one side of the light guide plate, and a reflective film disposed opposite to the bottom surface of the light guide plate, characterized in that, At most one optical film is accommodated between the liquid crystal cell and the light guide plate. The bottom surface of the light guide plate has a microstructure, and the microstructure has a light homogenizing portion and a light output angle adjusting portion.

2. The display module according to claim 1, characterized in that, The distance between the liquid crystal cell and the light guide plate is T, where 0.001 mm ≤ T ≤ 0.2 mm.

3. The display module according to claim 2, characterized in that, When 0.001 mm ≤ T ≤ 0.1 mm, the light guide plate is directly opposite to the liquid crystal cell.

4. The display module according to claim 2, characterized in that, An optical film is provided on the light output side of the light guide plate. The optical film is a diffusion film. The light output surface of the light guide plate is directly opposite to the diffusion film, and the diffusion film is directly opposite to the liquid crystal cell.

5. The display module according to claim 1, characterized in that, The minimum distance between the edge of the bottom surface of the light guide plate near the light incident surface and the microstructure is L, where 4 mm ≤ L ≤ 10 mm.

6. The display module according to claim 1, characterized in that, The X-axis, Y-axis, and Z-axis of the space rectangular coordinate system respectively correspond to the width direction, length direction, and height direction of the light guide plate. The Z-axis is perpendicular to the bottom surface of the light guide plate. It is characterized in that the bottom surface of the light guide plate has a microstructure. The width of the microstructure in the X-axis direction is not greater than 10 μm, the length of the microstructure in the Y-axis direction is not greater than 25 μm, and the height of the microstructure in the Z-axis direction is not greater than 7.5 μm.

7. The display module according to claim 1, characterized in that, The light output angle adjusting portion includes angle α1 and angle α2.

8. The display module according to claim 1, characterized in that, The microstructure has a light incident surface facing the light incident surface, a light back surface opposite to the light incident surface, and two connecting surfaces. The light incident surface extends obliquely away from the bottom surface. The light back surface extends obliquely from the bottom surface to one end of the light incident surface away from the bottom surface. The two connecting surfaces respectively connect the two sides of the light incident surface and the light back surface; the light incident surface is an arc surface, and the light incident surface bends towards the light back surface. The light homogenizing portion includes the light incident surface.

9. The display module according to claim 8, characterized in that, The light back surface is an arc surface, and the light back surface bends away from the light incident surface.

10. The display module according to claim 8, characterized in that, The microstructure recesses from the bottom surface into the light guide plate, and the light incident surface protrudes away from the light incident surface. Or, the microstructure protrudes from the bottom surface out of the light guide plate, and the light incident surface protrudes towards the light incident surface. When looking down or up at the outer contour of the microstructure along the Z-axis direction, it is a quadrilateral. The quadrilateral includes a first side, a second side, a third side, and a fourth side connected in sequence. The second side is the side of the light incident surface on the bottom surface, and the fourth side is the side of the light back surface on the bottom surface. Both the second side and the fourth side are arcs, and the bending directions are the same. The radius of curvature of the second side is R1, and the radius of curvature of the fourth side is R2, where 0 < R1 ≤ 50 μm, 0 < R2 ≤ 50 μm, and / or 0.9 ≤ R2 / R1 ≤ 1.

5. The radius of curvature of the second side is R1, the radius of curvature of the fourth side is R2, the chord length of the second side is L1, and the chord length of the fourth side is L2, where 0 < R1 / L1 ≤ 2.78, and / or 0 < R2 / L2 ≤ 2.

78. The chord length of the second side is L1, and the chord length of the fourth side is L2. L1 = L2. Or, L1 ≠ L2, and the included angle between the first side and the third side does not exceed 10°. The radius of curvature of the second side is R1, the radius of curvature of the fourth side is R2, the arc height of the second side is S1, the arc height of the fourth side is S2, 0 < S1 / R1 ≤ 1.5, and / or 0 < S2 / R2 ≤ 1.15; The longitudinal section of the microstructure is triangular, and the three sides of the triangle are the first section formed by the light-facing surface, the second section formed by the back-facing surface, and the base formed by connecting the ends of the first section and the second section. The first section and the second section are both straight lines, or at least one of the first section and the second section is an arc. The intersection of the first and second segments is the third vertex. The vertical distance from the third vertex to the base is H. The distance between the foot of the third vertex perpendicular to the base and the first vertex on the light-facing side is W1. The angle between the first segment and the base is α1, 22°≤α1≤48°, and / or 0.9≤W1 / H≤2.

48. The intersection of the first and second segments is the third vertex. The vertical distance from the third vertex to the base is H. The distance between the foot of the third vertex perpendicular to the base and the first vertex on the light-facing side is W1. The angle between the first segment and the base is α1, 49°≤α1≤56°, and / or 0.675≤W1 / H≤0.

87. The angle between the first slit and the bottom edge is α1, and the peak light emission angle of the light guide plate is β, |β|=|K×(α1-56)|, 1.3≤K≤1.6; The intersection of the first and second segments is the third vertex. The vertical distance from the third vertex to the bottom edge is H. The distance between the foot of the third vertex perpendicular to the bottom edge and the second vertex on the backlit side is W2. The angle between the second segment and the bottom edge is α2, 0.577≤W2 / H≤5.67, and / or 10°≤α2≤58°. The angle between the second segment and the bottom edge is α2, and the light emission range of the light guide plate is positively correlated with α2; The intersection of the first and second segments is the third vertex. The distance between the foot of the third vertex perpendicular to the bottom edge and the first vertex on the light-facing side is W1, and the distance between the foot of the third vertex perpendicular to the bottom edge and the second vertex on the shaded side is W2. 0.85≤W1 / W2≤2.

26. The connection lines between the two connecting surfaces and the light-facing surface are respectively the first connecting line and the third connecting line; the connection line between the light-facing surface and the backlighting surface is the second connecting line; and the connection lines between the backlighting surface and the two connecting surfaces are respectively the fourth connecting line and the fifth connecting line. At least two of the second side, the second connecting line, and the fourth side are arcs, and the arcs have the same curvature direction. The fourth connecting line and the fifth connecting line are straight lines or arcs, and the first connecting line and the third connecting line are straight lines or arcs. The light-diffusing section further includes at least one of the following: the curved backlight surface, the curved fifth connecting line, the curved first connecting line, the curved second connecting line, the curved third connecting line, and the curved fourth connecting line. The backlight unit includes at least two light guide plates, and each light guide plate has a separately controlled light source on one side; The backlight unit includes at least two light guide plates, each light guide plate corresponds to an independently controlled light source, and the absolute values ​​of the peak light emission angle β of each light guide plate are not equal, and / or the positive and negative signs of the peak light emission angle β of each light guide plate are different. The light guide plate is either a type I light guide plate or a type II light guide plate, and multiple light guide plates may be the same or different. The peak light emission angle of the type I light guide plate is β1, where |β1| ranges from 10.4° to 54.4°. The peak light emission angle of the type II light guide plate is β2, and |β2| takes a value in the range of 0° to 11.2°. The backlight unit includes at least two I-shaped light guide plates, wherein at least one of the I-shaped light guide plates has a positive peak light emission angle and at least the other I-shaped light guide plate has a negative peak light emission angle. Alternatively, the backlight unit includes at least one type I light guide plate and at least one type II light guide plate, wherein the angle between the principal ray of the type I light guide plate and the normal is greater than the angle between the principal ray of the type II light guide plate and the normal. The backlight unit includes only one light guide plate, which is a type II light guide plate.

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