Backlight module and display device

Abstract

The present application discloses a backlight module and a display device. The backlight module is used to provide backlight for a display panel. The backlight module includes a backlight source and a thermochromic film layer. The backlight source is used to provide a light source for the backlight module. The thermochromic film layer includes multiple thermochromic portions evenly arranged on the backlight source. When the thermochromic film layer is below a preset temperature, the thermochromic portions are in a non-transparent state, the backlight source emits light from between adjacent thermochromic portions, and the display panel is in a first display mode. When the electrothermal film layer is above or equal to a preset temperature, the thermochromic portions are in a transparent state, and the display panel is in a second display mode. By providing the thermochromic film layer, on the one hand, the thermochromic portions are used to achieve wide and narrow viewing angles, and on the other hand, the thermochromic film layer has a certain heat absorption capacity, which can improve the problem of heat accumulation in the backlight module.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a backlight module and a display device. Background Art

[0002] Existing liquid crystal display devices have a large viewing angle, but in some application scenarios, they cannot meet people's needs for information security. Anti-peeping display panels can effectively prevent observers from obtaining screen information within a certain visual area, thereby protecting the security of displayed information. Among the existing anti-peeping technologies, there are common external anti-peeping film solutions and backlight solutions. In the external anti-peeping film solution, a blind microstructure is installed on the outside of the LCD screen to limit the light output at large angles to achieve a narrow viewing angle display. In the backlight solution, a multi-layer functional film layer is set on the light guide plate to narrow the display viewing angle and ultimately achieve the purpose of anti-peeping.

[0003] However, for in-vehicle displays, when additional functional film layers are added, it will cause heat dissipation problems in the backlight module, resulting in various display problems due to heat accumulation in hot weather or outdoor use. Therefore, this application urgently needs an anti-peeping display panel that improves the performance in hot weather or outdoor use at higher temperatures. Summary of the Invention

[0004] The purpose of this application is to provide a backlight module and a display device. By setting a thermochromic film layer, on the one hand, wide and narrow viewing angle display can be achieved through the thermochromic part, and on the other hand, the problem of heat accumulation in the backlight module can be improved by utilizing the certain heat absorption capacity of the thermochromic film layer.

[0005] The present application discloses a backlight module, which is used to provide backlight for a display panel. The backlight module includes a backlight source and a thermochromic film layer, and the backlight source is used to provide a light source for the backlight module. The thermochromic film layer includes a plurality of thermochromic portions, which are evenly arranged on the backlight source. When the temperature of the thermochromic film layer is lower than a preset temperature, the thermochromic portions are in a non-transparent state, the backlight source emits light from between adjacent thermochromic portions, and the display panel is in a first display mode. When the temperature of the electrothermal film layer is higher than or equal to a preset temperature, the thermochromic portions are in a transparent state, and the display panel is in a second display mode.

[0006] Optionally, the thickness of the thermochromic portion is not less than 2 μm.

[0007] Optionally, the backlight module further includes an electrothermal film layer, which is arranged on the thermochromic film layer and is used to control the temperature transmitted to the thermochromic film layer; wherein, when the electrothermal film layer is lower than a preset temperature, the thermochromic portion is in a first state, which is a non-transparent state, and the backlight source emits light from between adjacent thermochromic portions; when the electrothermal film layer is greater than or equal to a preset temperature, the thermochromic portion is in a second state, which is a transparent state.

[0008] Optionally, the electric heating film layer includes multiple temperature rising parts, and the multiple temperature rising parts and the multiple thermochromic parts are arranged in a one-to-one correspondence; the temperature rising part is arranged on the side of the thermochromic part away from the backlight source; the backlight module also includes a temperature controller for controlling the temperature rising part to heat the thermochromic part.

[0009] Optionally, the electric heating film layer includes multiple temperature rising parts and multiple temperature falling parts, and one thermochromic part is respectively provided corresponding to one temperature rising part and one temperature falling part; the backlight module also includes a temperature controller for controlling the temperature rising part or the temperature falling part to heat or cool the thermochromic part.

[0010] Optionally, the display panel includes an opening area and a non-opening area, and the backlight module includes a light-emitting area and a non-light-emitting area, the light-emitting area is arranged corresponding to the opening area, and the non-light-emitting area is arranged corresponding to the non-opening area; the thermochromic portion is strip-shaped, and a plurality of the thermochromic portions are respectively arranged in the non-light-emitting area, and the plurality of the thermochromic portions are arranged in an array, and a gap is provided between two adjacent thermochromic portions.

[0011] Optionally, the display panel includes an opening area and a non-opening area, the opening area includes a plurality of sub-pixel areas, the backlight module includes a light-emitting area and a non-light-emitting area, the light-emitting area is arranged corresponding to the opening area, and the non-light-emitting area is arranged corresponding to the non-opening area; the thermochromic portion is arranged around the sub-pixel area or the plurality of sub-pixel areas, and the thermochromic portion is in the shape of a U-shaped character; two adjacent thermochromic portions are in direct contact with each other.

[0012] Optionally, the electric heating film layer includes a heat-conducting film layer, one end of which is connected to the backlight source for absorbing heat from the backlight source and transferring the heat to the thermochromic film layer.

[0013] Optionally, the backlight module is an edge-entry backlight module or a direct-type backlight module; the edge-entry backlight module includes a light bar and a light guide plate, the light guide plate is used to provide a surface light source for the display panel, and has a first surface, a second surface and a light incident surface, the first surface is a light emitting surface, and the light incident surface connects the first surface and the second surface; the light bar is arranged on the light incident surface of the light guide plate, and is used to provide a line light source for the light guide plate; the direct-type backlight module includes a base plate, a reflective sheet and a plurality of lamp beads, a plurality of the lamp bead arrays are arranged on the base plate, the reflective sheet is arranged on the side of the base plate where the lamp beads are arranged, the reflective sheet is provided with openings corresponding to the positions of the plurality of the lamp beads, and the lamp beads are arranged on the base plate after passing through the reflective sheet.

[0014] The present application also discloses a display device, which includes a display panel and the above-mentioned backlight module, and the backlight module provides a light source for the display panel.

[0015] The thermochromic film layer in the present application has a certain heat absorption capacity and can absorb part of the heat generated by the backlight module. The temperature of the backlight module can be reduced, and the temperature of the backlight module can be regulated, which is beneficial to the heat dissipation of the backlight module. Moreover, it can switch from a non-transparent state to a transparent state after absorbing heat. When the thermochromic portion is in a non-transparent state, since most of the light in the thermochromic portion cannot pass through, the light at a large angle is absorbed by the thermochromic portion, and the human eye cannot receive the light at a large viewing angle, thereby realizing a narrow viewing angle display, that is, a first display mode, which has a certain anti-peeping effect. When the thermochromic portion is in a transparent state, the light at a large angle passes directly through the thermochromic portion, and the human eye can also receive the light at a large viewing angle, thereby realizing a wide viewing angle display, that is, a second display mode, with a wider viewing angle. The present application utilizes heat control to realize viewing angle switching between narrow viewing angle and wide viewing angle for the display panel. For example, in-vehicle display screens, especially in summer, are exposed to high temperatures. The heat absorption capacity of the thermochromic part can be used to switch the display mode of the display panel from a narrow viewing angle to a wide viewing angle. On the one hand, this reduces the temperature of the display panel, and on the other hand, it makes the display panel have a wider viewing angle, higher brightness, and better display effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The included drawings are used to provide a further understanding of the embodiments of the present application, which constitute a part of the specification, are used to illustrate the implementation methods of the present application, and together with the text description, explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without inventive work. In the drawings:

[0017] Figure 1 This is a schematic diagram of a backlight module of the present application;

[0018] Figure 2 is a schematic diagram of a display panel of the present application;

[0019] Figure 3 is a schematic diagram of a thermochromic portion of the present application;

[0020] Figure 4 is a schematic diagram of another thermochromic portion of the present application;

[0021] Figure 5 This is a schematic diagram of an electric heating film layer of the present application;

[0022] Figure 6 It is a schematic diagram of another electric heating film layer of the present application;

[0023] Figure 7 is a cross-sectional schematic diagram of another backlight module of the present application;

[0024] Figure 8 is a schematic diagram of a display device of the present application.

[0025] Among them, 100, backlight module; 101, light emitting area; 102, non-light emitting area; 111, light strip; 112, light guide plate; 112a, first surface; 112b, second surface; 112c, light incident surface; 113, lamp beads; 114, bottom plate; 115, opening; 116, reflector; 130, thermochromic film layer; 131, thermochromic part; 140, electrothermal film layer; 141, heating part; 142, cooling part; 150, temperature controller; 151, heat conductive film layer; 200, display device; 210, display panel; 211, opening area; 212, non-opening area. DETAILED DESCRIPTION

[0026] It should be understood that the terms used herein, the specific structures and functional details disclosed are only for describing specific embodiments and are representative. However, the present application can be implemented in many alternative forms and should not be construed as being limited to the embodiments described herein.

[0027] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating relative importance or implicitly indicating the number of technical features indicated. Therefore, unless otherwise specified, features defined as "first" and "second" may explicitly or implicitly include one or more of such features; "multiple" means two or more. In addition, terms indicating orientation or positional relationships such as "upper", "lower", "left", "right", "vertical", and "horizontal" are based on the orientation or relative positional relationships shown in the accompanying drawings and are only for the convenience of describing a simplified description of this application, rather than indicating that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0028] The present application is described in detail below with reference to the accompanying drawings and optional embodiments.

[0029] Figure 1 This is a schematic diagram of a backlight module of the present application, see Figure 1 As shown, the present application discloses a backlight module 100, which is used to provide backlight for a display panel. The backlight module 100 includes a backlight source and a thermochromic film layer 130, and the backlight source is used to provide a light source for the backlight module 100; the thermochromic film layer 130 includes a plurality of thermochromic portions 131, which are evenly arranged on the backlight source; wherein, when the thermochromic film layer 130 is lower than a preset temperature, the thermochromic portions 131 are in a non-transparent state, the backlight source emits light from between adjacent thermochromic portions 131, and the display panel is in a first display mode; when the electrothermal film layer 140 is higher than or equal to the preset temperature, the thermochromic portions 131 are in a transparent state, and the display panel is in a second display mode.

[0030] The thermochromic film layer 130 in the present application has a certain heat absorption capacity and can absorb part of the heat generated by the backlight module 100. It can reduce the temperature of the backlight module 100, realize the temperature regulation of the backlight module 100, and is beneficial to the heat dissipation of the backlight module 100. Moreover, it can switch from a non-transparent state to a transparent state after absorbing heat. When the thermochromic portion 131 is in a non-transparent state, since most of the light in the thermochromic portion 131 cannot pass through, the light at a large angle is absorbed by the thermochromic portion 131, and the human eye cannot receive the light at a large viewing angle, thereby realizing a narrow viewing angle display, i.e., the first display mode, which has a certain anti-peeping effect. When the thermochromic portion 131 is in a transparent state, the light at a large angle passes directly through the thermochromic portion 131, and the human eye can also receive the light at a large viewing angle, thereby realizing a wide viewing angle display, i.e., the second display mode, which has a wider viewing angle. The present application uses heat control to realize the viewing angle switching between narrow viewing angle and wide viewing angle for the display panel. For example, when a car display screen is in a high temperature state, especially in summer, the heat absorption capacity of the thermochromic portion 131 can be utilized to switch the display mode of the display panel from a narrow viewing angle to a wide viewing angle, thereby reducing the temperature of the display panel on the one hand and making the viewing angle of the display panel larger, the brightness higher, and the display effect better on the other hand.

[0031] The first display mode is a narrow viewing angle display mode, and the second display mode is a wide viewing angle display mode. In the first display mode, since the wide-angle light in the backlight module 100 is scattered or further absorbed by the thermochromic portion 131, most of the wide-angle light no longer exits the opening area 211. When the display panel is viewed from a wide viewing angle, the human eye cannot receive the wide-angle outgoing light, achieving wide-angle anti-peeping display. In the second display mode, since the thermochromic portion 131 is transparent, it does not scatter or absorb the wide-angle light, achieving wide-viewing angle display.

[0032] It's worth noting that the material of the thermochromic film layer 130 used in this application comprises at least a composite material of polymethyl methacrylate (PMMA), polyvinylidene fluoride (PVDF), polycaprolactone (PCL), and silica (SiO2). The total mass fraction of the composite material can be PMMA / PVDF / PCL / SiO2 = 39 / 21 / 15 / 25. The transparency of the composite material is switched by a phase transition between the crystalline and molten states of the immiscible components, resulting in a low-temperature scattering and high-temperature transmittance switching function. At temperatures above the melting point of the immiscible components, light scattering is eliminated, and the thermochromic film layer 130 becomes transparent. At temperatures below the melting point of the immiscible components, i.e., below a predetermined temperature, the thermochromic film layer 130 becomes opaque, and light entering the thermochromic film emits a dispersed color, achieving a narrow viewing angle. Of course, a small amount of carbon black (CB) can also be added to the composite material to enhance heat absorption. Incorporating CB into the polymer mixture helps to enhance light absorption in the opaque state, converting scattered light into absorption for control and achieving a narrow viewing angle. The content of CB is 0.005 wt% of the blend.

[0033] See also Figure 1 As shown, the backlight module 100 of this embodiment is an edge-lit backlight module 100, comprising a light bar 111 and a light guide plate 112. The light guide plate 112 is used to provide a surface light source for the display panel and has a first surface 112a, a second surface 112b, and a light incident surface 112c. The first surface 112a is a light emitting surface, and the light incident surface 112c connects the first surface 112a and the second surface 112b. The light bar 111 is disposed on the light incident surface 112c of the light guide plate 112 to provide a linear light source for the light guide plate 112. A thermochromic film layer 130 is disposed on the first surface 112a of the light guide plate 112, and a reflective sheet 116 is disposed on the second surface 112b of the light guide plate 112.

[0034] Figure 2 This is a schematic diagram of the display panel of this application, see Figure 2 As shown, the display panel 210 generally includes an opening area 211 and a non-opening area 212. The opening area 211 and the non-opening area 212 are generally divided by a black matrix. The corresponding black matrix area is the non-opening area 212. The sub-pixels are generally set at the hollow position of the black matrix, and the sub-pixel area is the opening area 211.

[0035] Correspondingly, the backlight module 100 includes a light-emitting area 101 and a non-light-emitting area 102. The light-emitting area 101 is arranged corresponding to the opening area 211, and the non-light-emitting area 102 is arranged corresponding to the non-opening area 212. The light emitted from the light-emitting area 101 of the backlight module 100 enters the opening area 211, and the light emitted from the non-light-emitting area 102 enters the non-opening area 212. It can be understood that the non-light-emitting area 102 mentioned here does not mean that the backlight module 100 does not emit light in this area, but means that the light emitted from this area will generally be absorbed by the black matrix or other light-shielding film layer of the display panel.

[0036] Figure 3 This is a schematic diagram of a thermochromic portion of the present application, see Figure 3 As shown, specifically, the thermochromic portion 131 is strip-shaped, and multiple thermochromic portions 131 are respectively arranged in the non-light-exiting area 102 . The multiple thermochromic portions 131 are arranged in an array, and a gap is provided between two adjacent thermochromic portions 131 .

[0037] In this embodiment, by setting the thermochromic portion 131 in the non-light-emitting area 102, the light emitted from the non-light-emitting area 102 in the backlight module 100 generally passes through more film layers and is absorbed by the black matrix on the color filter layer and no longer emits. Generally speaking, the light emitted by the backlight source is not completely perpendicular to the light-emitting surface. There are also many light rays with a certain angle, which are processed by the diffuser plate or optical film layer and then enter the display panel. In this process, there are still many large-angle light rays that are emitted from the opening area 211. That is, there are some large-angle light rays that are emitted from between the black matrices to achieve a wide-viewing angle display.

[0038] In this embodiment, by providing a thermochromic portion 131 above the backlight source, when the thermochromic portion 131 is in a non-transparent state, most of the wide-angle light can be absorbed to form a narrow viewing angle display. It is understandable that since part of the light is absorbed by the thermochromic portion 131, the display effect under a narrow viewing angle is slightly inferior to that under a wide viewing angle. In a vehicle-mounted display panel, under high temperatures such as in summer or direct sunlight, the temperature of the display panel will rise, causing the light-emitting unit to heat up severely. If the light-emitting unit is in severe heating operation for a long time, it is prone to aging. To this end, the present application utilizes the fact that the thermochromic portion 131 has a certain heat absorption capacity. After absorbing heat, it automatically switches to a wide viewing angle to increase the display brightness.

[0039] Specifically, the thickness of the thermochromic portion 131 is no less than 2 μm. Thermochromic portion 131 requires a certain thickness to absorb or block light at wide angles. Relatively speaking, a thicker thermochromic portion 131 improves the wide-angle light filtering effect. However, a thicker thermochromic portion 131 increases the thickness of the backlight module 100, which is not conducive to thin and lightweight display devices.

[0040] The width of the thermochromic portion 131 can be one-quarter of its thickness. Of course, the width of the thermochromic portion 131 is related to the spacing between pixels (the width of the black matrix). The larger the spacing, the larger the width of the corresponding thermochromic portion 131 should be. From the perspective of heat absorption, the more thermochromic portions 131 there are, the stronger the corresponding heat absorption capacity. For an in-vehicle display panel, the thermochromic portion 131 can absorb more heat from the display panel during summer use.

[0041] In another embodiment, in the same non-opening area 212, when the width of the black matrix is ​​greater than the width of the multiple thermochromic portions 131, a plurality of spaced-apart thermochromic portions 131 may be provided in the same non-light-exiting area 102. The corresponding black matrix area, i.e., the non-opening area 212 uses a plurality of spaced-apart thermochromic portions 131 to absorb light incident into the non-light-exiting area 102 using the spaced-apart thermochromic portions 131.

[0042] It is understandable that the length of the thermochromic portion 131 in this embodiment can be a full-segment design or a multi-segment design. The full-segment design means that a long segment of the thermochromic portion 131 is arranged in columns or rows, spanning multiple sub-pixels, and specifically extending from one side of the display area to the opposite side to form a full-segment thermochromic portion 131, and its length is related to the length of the display area of ​​the display panel. The segmented design is that multiple segments of unconnected thermochromic portions 131 are arranged on the same row or column, and gaps are provided between adjacent thermochromic portions 131 in the length direction. It is understandable that when the thermochromic portion 131 is in a non-transparent state, the non-light-emitting area 102 on the backlight source where the thermochromic portion 131 is provided no longer emits light or only emits a small amount of light, and the emitted light of the backlight source is concentrated in the light-emitting area 101.

[0043] Furthermore, the spacing between adjacent thermochromic portions 131 is one pixel or multiple pixels or one sub-pixel or multiple sub-pixels, with one pixel generally comprising three sub-pixels. The opening area 211 includes multiple sub-pixel areas, each of which contains a sub-pixel. The sub-pixels may include sub-pixels of multiple colors, including but not limited to red, green, and blue sub-pixels. The spacing between adjacent thermochromic portions 131 of the present application can be one sub-pixel, resulting in the best privacy protection effect.

[0044] It is understandable that the privacy protection angle formed in this embodiment is privacy protection in a single direction of left and right or up and down. By providing the thermochromic portions 131 arranged at intervals, privacy protection in a direction perpendicular to the thermochromic portions 131 is achieved.

[0045] Figure 4 This is a schematic diagram of another thermochromic portion of the present application, see Figure 4 As shown, the thermochromic portion 131 is disposed around the one or more sub-pixel regions, and the thermochromic portion 131 is in a U-shape; two adjacent thermochromic portions 131 are in direct contact with each other.

[0046] In this embodiment, the U-shaped thermochromic portion 131 is provided to wrap each sub-pixel area, thereby forming a light channel when the thermochromic portion 131 is in a non-transparent state. When forming a narrow viewing angle display, the anti-peeping effect is better.

[0047] In one embodiment, the orthographic projection of the thermochromic film layer 130 on the substrate completely overlaps with the orthographic projection of the black matrix on the substrate. That is, the thermochromic film layer 130 is positioned entirely in accordance with the black matrix, with openings formed only in the light-emitting area 101 for light to escape. When the thermochromic film layer 130 is opaque, it blocks and absorbs most of the light from the non-light-emitting area 102, resulting in a narrow viewing angle display.

[0048] In this embodiment, by providing the thermochromic portion 131 surrounding the sub-pixels, it can be aligned with the orthographic projection of the display panel's black matrix on the substrate. In other words, the hollowed-out areas between the multiple thermochromic portions 131 formed by the thermochromic film layer 130 correspond precisely to the openings 211, achieving a one-to-one correspondence and improving privacy protection during narrow viewing angle display.

[0049] It is understandable that the display device mentioned in this application is set to a narrow viewing angle display by default when leaving the factory, and can be switched to a wide viewing angle display when the temperature rises.

[0050] Figure 5 This is a schematic diagram of an electric heating film layer of the present application, see Figure 5 As shown, based on the previous embodiment, this embodiment further adds an electric heating film layer 140 to actively control the display panel to switch between the first display mode and the second display mode, while in the previous embodiment, the control is mainly carried out by the external ambient temperature.

[0051] Specifically, the backlight module 100 also includes an electric heating film layer 140, which is arranged on the thermochromic film layer 130 and is used to control the temperature transmitted to the thermochromic film layer 130; wherein, when the electric heating film layer 140 is lower than a preset temperature, the thermochromic portion 131 is in a non-transparent state, the display panel is in a first display mode, and the backlight source emits light from between adjacent thermochromic portions 131; when the electric heating film layer 140 is greater than or equal to the preset temperature, the thermochromic portion 131 is in a transparent state, and the display panel is in a second display mode.

[0052] The preset temperature can be adjusted according to the proportion of each material in the thermochromic film layer 130, and the appropriate temperature can be selected. The preset temperature in this embodiment can be adjusted between 30-45 degrees. It can be understood that the display device of the present application focuses on solving the problem that the car display screen is easily affected by high temperature in summer. The thermochromic part 131 is used to absorb heat and phase change, and has a certain heat storage capacity to achieve heat absorption of the display panel and reduce the temperature of the display panel. In addition, in this process, the viewing angle can be changed from a narrow viewing angle to a wide viewing angle to achieve a better display effect. However, in this embodiment, the display panel can be switched between the first display mode and the second display mode through active control of the electric heating film layer 140. For example, in winter or when the temperature is low, the narrow viewing angle display can be actively switched to a wide viewing angle display through the action of the warming part 141.

[0053] Furthermore, the electric heating film layer 140 includes multiple temperature rising parts 141 and multiple temperature falling parts 142, and one thermochromic part 131 is respectively provided corresponding to one temperature rising part 141 and one temperature falling part 142; the backlight module 100 also includes a temperature controller 150 for controlling the temperature rising part 141 or the temperature falling part 142 to heat or cool the thermochromic part 131.

[0054] In this embodiment, each thermochromic portion 131 is controlled by a heating portion 141 and a cooling portion 142. In actual use, for example, under direct sunlight, the temperature of the vehicle screen is high. The thermochromic portion 131 absorbs a certain amount of heat and switches to a wide-viewing angle display. At this time, the cooling portion 142 can be controlled to drive the cooling portion 142 to operate, lowering the temperature of the thermochromic portion 131 to below a preset temperature, so that the display panel displays in the first display mode. At this time, due to the convergence effect of the reflective layer at a narrow viewing angle, the light brightness at the narrow viewing angle is higher, and the display can be displayed more clearly. Of course, it is understandable that due to the effect of the reflective layer, more frontal light will be received at a wide viewing angle, so the frontal viewing experience in the second display mode will also be better. However, relatively speaking, the thermochromic portion 131 only absorbs light at a large angle, and the thermochromic portion 131 also has a certain reflective effect, allowing more light to be emitted from between adjacent thermochromic portions 131, increasing the amount of light at a narrow viewing angle, making the brightness at a narrow viewing angle higher than that at a wide viewing angle.

[0055] In this embodiment, in addition to the heating unit 141, a cooling unit 142 is also provided. The main function of the cooling unit 142 is to control the corresponding thermochromic unit 131 to a preset temperature through the temperature controller 150. Through the flexible combination of the heating unit 141 and the cooling unit 142, the temperature of the thermochromic unit 131 can be controlled. In this embodiment, the driving modes of the multiple heating units 141 and the multiple cooling units 142 include but are not limited to individual driving, zone driving, or simultaneous driving. The temperature controller 150 controls the heating unit 141 to uniformly heat or cool the temperature, thereby controlling the thermochromic film layer 130. The heating unit 141 and the cooling unit 142 are respectively transparent electric heating film layers 140, with the heating unit 141 being a hot film and the cooling unit 142 being a cold film. Specifically, the cold film is primarily made of polyimide electric heating film, while the hot film is primarily made of polyethylene terephthalate electric heating film. The temperature of the thermochromic portion 131 is increased or decreased by controlling the power supply to the above-mentioned materials.

[0056] This embodiment of the present application further includes a thermally conductive film layer 151 in the temperature controller 150. The thermally conductive film layer 151 is configured to conduct heat and is made of a heat-conducting metal material, such as aluminum or copper. One end of the thermally conductive film layer 151 is connected to the backlight source, and the other end of the thermally conductive film layer 151 is connected to the temperature-raising unit 141, transferring heat from the light source to the temperature-raising unit 141.

[0057] Since the LED in the light source tends to generate a lot of heat when emitting light, how to effectively dissipate the heat of the light-emitting unit is also an important direction in this field. In this embodiment, the heat-conductive film layer 151 can be used to transfer the heat generated by the LED to the electric heating film, which can not only effectively dissipate the heat of the light source, but also recycle and utilize the heat. It can also supplement the heat provided by the heating part 141 and the temperature controller 150 to reduce the power consumption of the temperature controller 150.

[0058] Specifically, in actual use, the thermally conductive film layer 151 first transfers the heat in the light source to the electric heating film, and the temperature sensing layer in the temperature controller 150 monitors the temperature of the temperature rising portion 141 caused by the thermally conductive film layer 151. If it is found that the heat is insufficient, the temperature rising portion 141 can be powered again to further increase the temperature of the temperature rising portion 141, so that the thermochromic portion 131 reaches the preset temperature.

[0059] In this embodiment, the temperature rising part 141 and the temperature cooling part 142 can be arranged in an alternating manner. For example, at the position of the same thermochromic part 131, multiple connected temperature rising parts 141 and multiple connected temperature cooling parts 142 are arranged, and the temperature rising parts 141 and the temperature cooling parts 142 are arranged in an alternating manner.

[0060] Figure 6 This is a schematic diagram of another electric heating film layer of the present application, see Figure 6 As shown, the cooling portion 142 is circular, and the heating portion 141 is annular. The heating portion 141 surrounds the cooling portion 142, making the cooling portion 142 larger and directly opposite the thermochromic portion 131. The heating portion 141 corresponds to the edge of the thermochromic portion 131. By evenly disposing the heating portion 141 and the cooling portion 142 in this embodiment, the temperature change at each location of the corresponding thermochromic portion 131 is more uniform.

[0061] Figure 7 This is a cross-sectional schematic diagram of another backlight module of the present application, see Figure 7 As shown, the present application discloses a direct-lit backlight module 100, which includes a base plate 114, a reflective sheet 116, and a plurality of lamp beads 113. The plurality of lamp beads 113 are arranged in an array on the base plate 114. The reflective sheet 116 is arranged on one side of the base plate 114 where the lamp beads 113 are arranged. The reflective sheet 116 has openings 115 corresponding to the positions of the plurality of lamp beads 113. The lamp beads 113 pass through the reflective sheet 116 and are arranged on the base plate 114. The thermochromic portions 131 are respectively arranged on one or more sides of the lamp beads 113, with a certain distance between the thermochromic portions 131 and the lamp beads 113. Any of the above embodiments is also applicable to the direct-lit backlight module 100.

[0062] Figure 8is a schematic diagram of the display device of this application, see Figure 8 As shown, the present application discloses a display device. The present application discloses a display device 200 , which includes a display panel 210 and the above-mentioned backlight module 100 . The backlight module 100 provides a light source for the display panel.

[0063] Among them, the display panel can be various display panels, such as TN (Twisted Nematic) display panel, IPS (In-Plane Switching) display panel, VA (Vertical Alignment) display panel, MVA (Multi-Domain Vertical Alignment) display panel. Of course, it can also be other types of display panels, such as Mini-LED display panel, all of which are applicable to the above solution.

[0064] The thermochromic film layer 130 in the present application has a certain heat absorption capacity and can absorb part of the heat generated by the backlight module 100. It can reduce the temperature of the backlight module 100, realize the temperature regulation of the backlight module 100, and is beneficial to the heat dissipation of the backlight module 100. Moreover, it can switch from a non-transparent state to a transparent state after absorbing heat. When the thermochromic portion 131 is in a non-transparent state, since most of the light in the thermochromic portion 131 cannot pass through, the light at a large angle is absorbed by the thermochromic portion 131, and the human eye cannot receive the light at a large viewing angle, thereby realizing a narrow viewing angle display, i.e., the first display mode, which has a certain anti-peeping effect. When the thermochromic portion 131 is in a transparent state, the light at a large angle passes directly through the thermochromic portion 131, and the human eye can also receive the light at a large viewing angle, thereby realizing a wide viewing angle display, i.e., the second display mode, which has a wider viewing angle. The present application uses heat control to realize the viewing angle switching between narrow viewing angle and wide viewing angle for the display panel. For example, when a car display screen is in a high temperature state, especially in summer, the heat absorption capacity of the thermochromic portion 131 can be utilized to switch the display mode of the display panel from a narrow viewing angle to a wide viewing angle, thereby reducing the temperature of the display panel on the one hand and making the viewing angle of the display panel larger, the brightness higher, and the display effect better on the other hand.

[0065] It should be noted that the inventive concept of this application can form a large number of embodiments, but the length of the application document is limited and it is impossible to list them one by one. Therefore, under the premise of no conflict, the various embodiments or technical features described above can be arbitrarily combined to form new embodiments. After the various embodiments or technical features are combined, the original technical effects will be enhanced.

[0066] The above content is a further detailed description of the present application in conjunction with specific optional implementation methods, and the specific implementation of the present application cannot be considered to be limited to these descriptions. For ordinary technicians in the technical field to which the present application belongs, they can make several simple deductions or substitutions without departing from the concept of the present application, which should be considered to fall within the scope of protection of the present application.

Claims

1. A backlight module, which is used to provide backlight for a display panel, characterized in that: include: A backlight source, used to provide light source for the backlight module; The thermochromic film layer includes a plurality of thermochromic parts, which are evenly arranged on the backlight source; When the temperature of the thermochromic film layer is lower than a preset temperature, the thermochromic portion is in a non-transparent state, the light emitted by the backlight source is emitted from between adjacent thermochromic portions, and the display panel is in a first display mode; when the temperature of the thermochromic film layer is higher than or equal to a preset temperature, the thermochromic portion is in a transparent state, and the display panel is in a second display mode; The backlight module further includes an electric heating film layer, which is arranged on the thermochromic film layer and is used to control the temperature transmitted to the thermochromic film layer; When the temperature of the electrothermal film layer is lower than a preset temperature, the thermochromic portion is in a first state, which is a non-transparent state, and the light emitted by the backlight source is emitted from between adjacent thermochromic portions; when the temperature of the electrothermal film layer is greater than or equal to a preset temperature, the thermochromic portion is in a second state, which is a transparent state. The electric heating film layer includes a plurality of temperature-raising parts and a plurality of temperature-lowering parts, and one thermochromic part is respectively provided corresponding to one temperature-raising part and one temperature-lowering part; the temperature-lowering part is circular, the temperature-raising part is annular, and the temperature-raising part is provided around the temperature-lowering part; The backlight module further includes a temperature controller for controlling the temperature raising unit or the temperature lowering unit to raise or lower the temperature of the thermochromic unit.

2. The backlight module according to claim 1, wherein: The thickness of the thermochromic portion is not less than 2 μm.

3. The backlight module according to claim 1, wherein: The electrothermal film layer includes a plurality of temperature-raising portions, and the plurality of temperature-raising portions and the plurality of thermochromic portions are arranged in a one-to-one correspondence; the temperature-raising portion is arranged on a side of the thermochromic portion away from the backlight source; The backlight module further includes a temperature controller for controlling the temperature raising unit to raise the temperature of the thermochromic unit.

4. The backlight module according to claim 1, wherein: The display panel includes an opening area and a non-opening area, and the backlight module includes a light-emitting area and a non-light-emitting area, wherein the light-emitting area is arranged corresponding to the opening area, and the non-light-emitting area is arranged corresponding to the non-opening area; The thermochromic portion is in a strip shape, and a plurality of the thermochromic portions are respectively arranged in the non-light-exiting area. The plurality of the thermochromic portions are arranged in an array, and a gap is provided between two adjacent thermochromic portions.

5. The backlight module according to claim 1, wherein: The display panel includes an opening area and a non-opening area, the opening area includes a plurality of sub-pixel areas, the backlight module includes a light-emitting area and a non-light-emitting area, the light-emitting area is arranged corresponding to the opening area, and the non-light-emitting area is arranged corresponding to the non-opening area; The thermochromic portion is arranged around one or more sub-pixel areas, and the thermochromic portion is in a U-shape; two adjacent thermochromic portions are in direct contact with each other.

6. The backlight module according to claim 1, wherein: The electric heating film layer includes a heat-conducting film layer, one end of which is connected to the backlight source, and is used for absorbing the heat of the backlight source and transferring the heat to the thermochromic film layer.

7. The backlight module according to claim 1, wherein: The backlight module is an edge-type backlight module or a direct-type backlight module; The edge-lit backlight module includes a light bar and a light guide plate. The light guide plate is used to provide a surface light source for the display panel and has a first surface, a second surface, and a light incident surface. The first surface is a light emitting surface, and the light incident surface connects the first surface and the second surface. The light bar is arranged on the light incident surface of the light guide plate to provide a linear light source for the light guide plate. The direct-type backlight module includes a base plate, a reflective sheet and a plurality of lamp beads. The plurality of lamp bead arrays are arranged on the base plate. The reflective sheet is arranged on the side of the base plate where the lamp beads are arranged. The reflective sheet is provided with openings corresponding to the positions of the plurality of lamp beads. The lamp beads are arranged on the base plate after passing through the reflective sheet.

8. A display device, characterized in that: The display device includes a display panel and the backlight module according to any one of claims 1 to 7, wherein the backlight module provides a light source for the display panel.

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