Backlight module and display device

Abstract

The application discloses a backlight module and a display device. The backlight module comprises a backlight source, a reflection layer and a thermochromic film layer. The backlight source is used for providing a light source for the backlight module. The reflection layer is provided with a plurality of reflection parts which are uniformly arranged on the backlight source. The reflection parts are used for reflecting light rays emitted by the backlight source into the reflection layer. The thermochromic film layer is arranged on the reflection layer and comprises a plurality of thermochromic parts which are arranged in correspondence with the plurality of reflection parts. When the temperature is lower than a preset temperature, the thermochromic part is in a non-transparent state, and the display panel is in a first display mode. When the temperature is not lower than the preset temperature, the thermochromic part is in a transparent state, and the display panel is in a second display mode. The viewing angle of the first display mode is smaller than that of the second display mode, and the brightness of the first display mode is higher than that of the second display mode. The reflection layer is arranged to realize higher brightness and better display effect in narrow viewing angle display.

Description

Technical Field

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

[0002] Existing LCD displays offer wide viewing angles, but in certain applications, they cannot meet the information security needs of users. Privacy-protected display panels can effectively prevent observers from accessing screen information within a defined visual area, thus protecting the displayed information. Common privacy-protection technologies include external privacy films and backlighting. External privacy films achieve narrow viewing angles by using a micro-structure resembling louvers attached to the LCD screen to limit light emission at wide angles. Backlighting solutions narrow the viewing angle and ultimately achieve privacy by applying multiple functional film layers to the light guide plate.

[0003] However, for in-vehicle displays, there is a need for privacy protection, and they are easily exposed to direct sunlight, resulting in poor display effects due to narrow viewing angles. Therefore, this application urgently needs an improvement solution to address these issues. Summary of the Invention

[0004] The purpose of this application is to provide a backlight module and a display device. This solution achieves higher brightness and better display effect under narrow viewing angle by setting a reflective layer.

[0005] This application discloses a backlight module for providing backlight to a display panel. The backlight module includes a backlight source, a reflective layer, and a thermochromic film layer. The backlight source provides a light source for the backlight module. The reflective layer has multiple reflective portions uniformly arranged on the backlight source, which reflect light incident from the backlight source. The thermochromic film layer is disposed on the reflective layer and includes multiple thermochromic portions corresponding to the reflective portions. When the thermochromic portion is below a preset temperature, it is in a non-transparent state, and the display panel is in a first display mode. When the thermochromic portion is at or above the preset temperature, it is in a transparent state, and the display panel is in a second display mode. The viewing angle of the first display mode is smaller than that of the second display mode, and the brightness of the first display mode is higher than that of the second display mode.

[0006] Optionally, the display panel includes an opening area and a non-opening area, the backlight module includes a light-emitting area and a non-light-emitting area, the light-emitting area is disposed corresponding to the opening area, and the non-light-emitting area is disposed corresponding to the non-opening area; a plurality of the reflection portions are disposed in the non-light-emitting area; a plurality of the thermochromic portions are disposed in the non-light-emitting area; the reflection portions are configured to reflect the light emitted by the backlight source into the non-light-emitting area.

[0007] Optionally, the backlight module further includes an electrothermal film layer disposed on the thermochromic film layer for controlling the temperature transferred to the thermochromic film layer; wherein, when the electrothermal film layer is less than a preset temperature, the thermochromic portion is in an opaque state, the display panel is in a first display mode, and the light emitted by the backlight source is emitted from between adjacent thermochromic portions; when the electrothermal film layer is greater than or equal to the preset temperature, the thermochromic portion is in a transparent state, and the display panel is in a second display mode.

[0008] Optionally, the electrothermal film layer includes a plurality of heating portions and a plurality of cooling portions, and one thermochromic portion is respectively disposed corresponding to one heating portion and one cooling portion; the backlight module further includes a temperature controller configured to control the heating portion or the cooling portion to heat or cool the thermochromic portion.

[0009] Optionally, the thermochromic portion is strip-shaped, a plurality of the thermochromic portions are arranged in an array, and a gap is provided between adjacent two thermochromic portions.

[0010] Optionally, the opening area includes a plurality of sub-pixel areas, the thermochromic portion surrounds one or a plurality of the sub-pixel areas, and the thermochromic portion is in a shape of a rectangle with a hole in the middle; adjacent two thermochromic portions are in direct contact.

[0011] Optionally, the reflection portions and the thermochromic portions are identical in shape and number and are disposed in a one-to-one correspondence; the thickness of the reflection portion is less than the thickness of the thermochromic portion, and the thickness of the thermochromic portion is not less than 2 um.

[0012] Optionally, the reflection portion is formed of a porous silicon material; the thermochromic film layer is a composite material including at least polymethyl methacrylate, polyvinylidene fluoride, polycaprolactone, and silicon dioxide.

[0013] Optionally, the backlight module is an edge-lit backlight module or a direct-lit backlight module; the edge-lit backlight module includes a lamp 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 lamp bar is disposed on the light-incident surface of the light guide plate and is used to provide a line light source for the light guide plate, and the reflective layer is disposed on the second surface of the light guide plate; the direct-lit backlight module includes a base plate, a reflective sheet and a plurality of lamp beads, the plurality of lamp beads are arranged in an array on the base plate, the reflective sheet is disposed on the side of the base plate on which the lamp beads are disposed, the reflective sheet has openings corresponding to the positions of the plurality of lamp beads, and the lamp beads pass through the reflective sheet and are disposed on the base plate; each lamp bead has a reflective portion on at least one side.

[0014] This application discloses a display device, which includes a display panel and the aforementioned backlight module, wherein the backlight module provides a light source for the display panel.

[0015] This application utilizes a reflective section and a thermochromic section, with the thermochromic section and reflective section positioned correspondingly. On one hand, the thermochromic section absorbs heat, allowing it to switch between an opaque and transparent state, thus enabling switching between narrow and wide viewing angles. During the heat absorption process of the thermochromic section, the temperature of the backlight module can be reduced, allowing for temperature regulation and facilitating heat dissipation. On the other hand, the reflective section, positioned corresponding to the thermochromic section, reflects most of the light incident on the thermochromic section back to the backlight source, which then emits light from between the thermochromic sections, enhancing the brightness of the display panel. When the display panel is used for automotive displays, ambient light such as direct sunlight causes the temperature to rise. The heat absorption of the thermochromic section reduces the overall heat of the display panel. When the temperature reaches a preset temperature, the thermochromic section becomes transparent, achieving a wide viewing angle. When the temperature is below the preset temperature, the thermochromic section remains opaque, achieving a narrow viewing angle. Especially at narrow viewing angles, due to the function of the reflector, it is possible to collect most of the light rays that are not displayed at large angles without increasing the driving voltage, and then re-emit them, which greatly improves the brightness of narrow viewing angle displays and enhances the in-vehicle display effect. Attached Figure Description

[0016] The accompanying drawings, which form part of the specification, are used to provide a further understanding of the embodiments of this application and illustrate the implementation methods of this application, together with the textual description, to explain the principles of this application. Obviously, the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any creative effort. In the drawings:

[0017] Figure 1 This is a schematic diagram of a backlight module according to this application;

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

[0019] Figure 3a This is a cross-sectional schematic diagram of another backlight module of this application;

[0020] Figure 3b This is a top view schematic diagram of another backlight module of this application;

[0021] Figure 4 This is a schematic diagram of a thermochromic part of this application;

[0022] Figure 5 This is a schematic diagram of another thermochromic part of this application;

[0023] Figure 6 This is a schematic diagram of an electrothermal film layer according to this application;

[0024] Figure 7 This is a schematic diagram of another electrothermal film layer of this application;

[0025] Figure 8 This is a schematic diagram of the display device of this application.

[0026] Among them, 100 is the backlight module; 101 is the light-emitting area; 102 is the non-light-emitting area; 111 is the LED strip; 112 is the light guide plate; 112a is the first surface; 112b is the second surface; 112c is the light-incident surface; 113 is the LED bead; 114 is the base plate; 115 is the opening; 116 is the reflective sheet; 120 is the reflective layer; 121 is the reflective part; 130 is the thermochromic film layer; 131 is the thermochromic part; 140 is the electrothermal film layer; 141 is the heating part; 142 is the cooling part; 150 is the temperature controller; 151 is the thermally conductive film layer; 200 is the display device; 210 is the display panel; 211 is the opening area; and 212 is the non-opening area. Detailed Implementation

[0027] It should be understood that the terminology, specific structural and functional details used herein are merely for describing particular embodiments and are representative. However, this application may be implemented in many alternative forms and should not be construed as being limited to the embodiments set forth herein.

[0028] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating relative importance or implying the number of technical features indicated. Therefore, unless otherwise stated, a feature specified as "first" or "second" may explicitly or implicitly include one or more of that feature; "multiple" means two or more. Furthermore, terms indicating orientation or positional relationships, such as "upper," "lower," "left," "right," "vertical," and "horizontal," are described based on the orientation or relative positional relationships shown in the accompanying drawings and are only for the purpose of simplifying the description of this application, not indicating that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0029] The present application will now be described in detail with reference to the accompanying drawings and optional embodiments.

[0030] Figure 1 This is a schematic diagram of a backlight module according to this application. See also: Figure 1 As shown, this application discloses a backlight module 100, which includes a backlight source, a reflective layer 120, and a thermochromic film layer 130. The backlight source provides a light source for the backlight module 100. The reflective layer 120 is provided with a plurality of reflective portions 121, which are uniformly arranged on the backlight source. The reflective portions 121 are used to reflect light from the backlight source that enters the reflective layer 120. The thermochromic film layer 130 is disposed on the reflective layer 120 and includes a plurality of thermochromic portions 131. A thermochromic part is correspondingly disposed with a plurality of the reflective parts 121; wherein, when the thermochromic part 131 is below a preset temperature, the thermochromic part 131 is in a non-transparent state, and the display panel is in a first display mode; when the thermochromic part 131 is not below the preset temperature, the thermochromic part 131 is in a transparent state, and the display panel is in a second display mode; the viewing angle of the first display mode is smaller than that of the second display mode, and the brightness of the first display mode is higher than that of the second display mode.

[0031] This application incorporates a reflective section 121 and a thermochromic section 131, with the thermochromic section 131 and the reflective section 121 arranged correspondingly. On one hand, the thermochromic section 131 absorbs heat, allowing it to switch between an opaque and transparent state, thus enabling switching between narrow and wide viewing angles. During the heat absorption process of the thermochromic section 131, the temperature of the backlight module 100 can be reduced, achieving temperature regulation and facilitating heat dissipation. On the other hand, the reflective section 121, corresponding to the thermochromic section 131, reflects most of the light incident on the thermochromic section 131 back to the backlight source, which then emits light from between the thermochromic sections 131, thereby enhancing the brightness of the display panel. When the display panel is used for automotive displays, the temperature rises due to external ambient light such as direct sunlight. The thermochromic element 131 absorbs heat to reduce the overall heat of the display panel. When the temperature reaches a preset temperature, the thermochromic element 131 becomes transparent, achieving a wide viewing angle. When the temperature is below the preset temperature, the thermochromic element 131 is opaque, achieving a narrow viewing angle. Especially at narrow viewing angles, due to the reflective element 121, most of the light rays at large angles and those not being displayed can be collected and re-emitted without increasing the driving voltage, greatly improving the brightness of the narrow viewing angle display and enhancing the automotive display effect.

[0032] 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, because the large-angle light from the backlight module 100 is scattered or further absorbed by the thermochromic part 131, most of the large-angle light no longer escapes from the opening area. When viewing the display panel at a wide viewing angle, the human eye cannot receive the large-angle emitted light, achieving a wide-angle privacy display. In the second display mode, because the thermochromic part 131 is transparent, it does not scatter or absorb large-angle light, achieving a wide viewing angle display. Furthermore, in the second display mode, the reflective layer 120 also enhances the display brightness at wide viewing angles.

[0033] It is worth mentioning that the thermochromic film layer 130 used in this application is made of at least a composite material of polymethyl methacrylate (PMMA), polyvinylidene fluoride (PVDF), polycaprolactone (PCL), and silica (SiO2), with a total mass fraction of PMMA / PVDF / PCL / SiO2 = 39 / 21 / 15 / 25. The transparency switching of the composite material is achieved through a phase transition between the immiscible phases in the crystalline and molten states, thus possessing a transparency switching function of low-temperature scattering and high-temperature transmission. At temperatures above the melting points of the immiscible components, light scattering is eliminated, and the thermochromic film layer 130 is transparent. At temperatures below the melting points of the immiscible components, i.e., below a preset temperature, the thermochromic film layer 130 is opaque, and light scatters after entering the thermochromic part 131, achieving a narrow viewing angle. A small amount of carbon black (CB) can also be added to the composite material, which improves the heat absorption effect. Incorporating CB into the polymer mixture helps to maintain a certain light absorption capacity in the opaque state, controlling the conversion of light scattering into absorption and achieving a narrow viewing angle. The content of CB in the blend is 0.005 wt%.

[0034] The reflective layer 120 is made of porous silicon, which has good thermal insulation properties (its insulation performance does not decrease with deformation), ensuring that the heat from light does not increase the heat of the film. Porous silicon can be a bulk material with a large uniform area and the ability to be processed into any shape. These characteristics are considered advantageous for manufacturing easily handled reflective materials. Its internal framework has a diameter of a few micrometers and also possesses high porosity, low packing density, excellent thermal insulation performance, and excellent water resistance.

[0035] This application combines a thermochromic film layer 130 made of composite materials and a highly reflective porous silicon material with a panel display. By reusing the heat generated by the panel, it not only achieves privacy protection and increases the brightness of the display panel, but also reduces power consumption due to heat dissipation, as seen in automotive applications. Display screens operate under high temperatures for extended periods, resulting in excessive heat load and increased power consumption. Therefore, the thermochromic film layer 130 can absorb heat, reduce the heat load, lower power consumption, and achieve privacy protection. Simultaneously, the highly reflective porous silicon material improves brightness in wide viewing angle / privacy mode. This will, to some extent, enhance the competitiveness of the display panel, meet customer needs, and increase customer satisfaction.

[0036] Figure 2 This is a schematic diagram of the display panel of this application; see below. Figure 2As 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 area corresponding to the black matrix is ​​the non-opening area. Sub-pixels (R, G, B) are generally set at the cutout position of the black matrix, and the sub-pixel area is the opening area 211.

[0037] Correspondingly, the backlight module 100 includes a light-emitting area 101 and a non-light-emitting area 102. The light-emitting area 101 corresponds to the opening area, and the non-light-emitting area 102 corresponds to the non-opening area. Light emitted from the light-emitting area 101 of the backlight module 100 enters the opening area, and light emitted from the non-light-emitting area 102 enters the non-opening area. It is 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 rather that the light emitted from this area is generally absorbed by the black matrix or other light-shielding film layers of the display panel.

[0038] A plurality of the reflective portions 121 are disposed in the non-light-emitting area 102; a plurality of the thermochromic portions 131 are disposed in the non-light-emitting area 102; the reflective portions 121 are used to reflect the light from the backlight source that enters the non-light-emitting area 102.

[0039] In actual display, the light from the non-light-emitting area 102 is generally lost in the various film layers of the display panel. In this solution, the reflective part 121 is provided corresponding to the non-light-emitting area 102. By providing the reflective part 121, the light that was originally lost in the various film layers of the display panel is reflected back to the backlight. After being reflected again by the backlight, most of the light can be emitted from between the adjacent reflective parts 121, that is, from the light-emitting area 101.

[0040] See Figure 1 As shown, the backlight module 100 in this embodiment is a side-lit backlight module 100. The side-lit backlight module 100 includes a lamp strip 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, 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 lamp strip 111 is disposed on the light incident surface of the light guide plate 112 and is used to provide a line light source for the light guide plate 112. The reflective layer 120 is disposed on the second surface of the light guide plate 112.

[0041] Specifically, the reflective part 121 is located in each non-light-emitting area 102 on the light guide plate 112, which intercepts the light from the non-light-emitting area 102 and realizes the utilization of the light from the non-light-emitting area 102 after multiple reflections.

[0042] In this embodiment, the thermochromic part 131 has a certain heat absorption capacity. When the external temperature rises, the thermochromic part 131 absorbs heat to achieve the effect of cooling the display panel. After absorbing heat, it can switch from privacy mode to wide viewing angle mode.

[0043] Figure 3a This is a cross-sectional schematic diagram of another backlight module of this application. Figure 3b This is a top view schematic diagram of another backlight module of this application, see below. Figures 3a-3b As shown, this application discloses a direct-lit backlight module 100, which includes a base plate 114, a reflector 116, and a plurality of LEDs 113. The plurality of LEDs 113 are arrayed on the base plate 114. The reflector 116 is disposed on the side of the base plate 114 where the LEDs 113 are disposed. The reflector 116 has openings 115 corresponding to the positions of the plurality of LEDs 113. The LEDs 113 pass through the reflector 116 and are disposed on the base plate 114. Each LED 113 has a reflective part 121 on at least one side.

[0044] Specifically, the reflective portion 121 can be arranged in a ring, surrounding the LED beads 113, so that most of the light from the LED beads 113 is emitted from the light-emitting area 101 of the backlight module 100, thereby achieving light reuse. The thickness of the reflective portion 121 is between 0.5 μm and 2 μm.

[0045] In this design, the reflective part 121 is provided corresponding to the non-light-emitting area 102. By providing the reflective part 121, the light that was originally lost in the various film layers of the display panel is reflected back into the backlight. After being reflected again by the backlight, most of the light can be emitted from between the adjacent reflective parts 121, that is, from the light-emitting area 101.

[0046] Figure 4 This is a schematic diagram of a thermochromic part of this application, see [link / reference]. Figure 4 As shown, specifically, the thermochromic part 131 is strip-shaped, and a plurality of thermochromic parts 131 are arranged in an array, with a gap provided between two adjacent thermochromic parts 131.

[0047] Furthermore, the spacing between adjacent thermochromic portions 131 is one pixel, one subpixel, or multiple pixels, with one pixel generally comprising three subpixels. In this embodiment, the thermochromic portion 131 can be elongated or segmented.

[0048] It is understood that the privacy protection angle formed in this embodiment is a single direction of left-right or up-down privacy protection. By setting the thermochromic parts 131 arranged at intervals, privacy protection in the direction perpendicular to the thermochromic parts 131 is achieved.

[0049] Figure 5 It is a schematic diagram of another thermochromic part of the present application. Refer to Figure 5 As shown, specifically, the opening area includes a plurality of sub-pixel areas, and the thermochromic part 131 is arranged around one or more of the sub-pixel areas, and the thermochromic part 131 is in a zigzag shape; two adjacent thermochromic parts 131 are in direct contact with each other.

[0050] In this embodiment, by arranging the thermochromic part 131 around the sub-pixels, it can coincide with the orthographic projection of the black matrix of the display panel on the substrate. In other words, the hollow areas between the plurality of thermochromic parts 131 formed by the thermochromic film layer 130 exactly correspond to the opening area, achieving a one-to-one correspondence setting, so that the anti-peeping effect during narrow-angle display is better.

[0051] Specifically, the shape and quantity of the reflection part 121 are the same as those of the thermochromic part 131, and they are arranged in one-to-one correspondence. That is, the shape of the reflection part 121 is set according to the shape of the thermochromic part 131, and the quantity and position are set to be the same to achieve the best matching effect.

[0052] Of course, it is also possible that the number of the reflection parts 121 is greater than the number of the thermochromic parts 131. By completely covering the non-light-emitting area 102 of the backlight module 100 with the reflection parts 121, the light can only be emitted from the light-emitting area 101 of the light guide plate 112, so as to maximally improve the brightness of the opening area of the display panel.

[0053] Specifically, the thickness of the reflection part 121 is less than the thickness of the thermochromic part 131. The thickness of the thermochromic part 131 is not less than 2 μm, and the thickness of the reflection part 121 is between 0.5 μm and 2 μm.

[0054] Figure 6 It is a schematic diagram of an electrothermal film layer of the present application. Refer to Figure 6 As shown, on the basis of the previous embodiment, an electrothermal film layer 140 is further added in this embodiment to actively control the switching of the display panel between the first display mode and the second display mode. In the previous embodiment, it was mainly controlled by the external environmental temperature.

[0055] Specifically, the backlight module 100 further includes an electrothermal film layer 140, which is disposed on the thermochromic film layer 130 and is used to control the temperature transmitted to the thermochromic film layer 130. When the temperature of the electrothermal film layer 140 is lower than a preset temperature, the thermochromic part 131 is in a non-transparent state, the display panel is in a first display mode, and the backlight emits light from between adjacent thermochromic parts 131. When the temperature of the electrothermal film layer 140 is greater than or equal to the preset temperature, the thermochromic part 131 is in a transparent state, and the display panel is in a second display mode.

[0056] The preset temperature can be adjusted according to the proportion of each material in the thermochromic film layer 130, and a suitable temperature can be selected. In this embodiment, the preset temperature can be adjusted between 30-45 degrees Celsius. It is understood that the display device of this application focuses on solving the problem that in-vehicle display screens are easily affected by high temperatures in summer. The thermochromic part 131 absorbs heat and undergoes a phase change, which has a certain heat storage capacity, to achieve heat absorption of the display panel and reduce the temperature of the display panel. Moreover, in this process, the viewing angle can be changed from narrow to wide, achieving a better display effect. However, in this embodiment, the display panel can switch between a first display mode and a second display mode through active control of the electrothermal film layer 140.

[0057] Furthermore, the electrothermal film layer 140 includes a plurality of heating sections 141 and a plurality of cooling sections 142, and one thermochromic section 131 is respectively provided for one heating section 141 and one cooling section 142; the backlight module 100 also includes a temperature controller 150, which is used to control the heating section 141 or the cooling section 142 to heat up or cool down the thermochromic section 131.

[0058] In this embodiment, each thermochromic unit 131 is controlled by a heating unit 141 and a cooling unit 142. In actual use, such as under direct sunlight, the temperature of the vehicle screen is high. After absorbing a certain amount of heat, the thermochromic unit 131 switches to wide-viewing-angle display. At this time, it can be controlled to drive the cooling unit 142 to work, reducing the temperature of the thermochromic unit 131 to below the preset temperature, so that the display panel can display in the first display mode. At this time, due to the converging effect of the reflective layer 120, the light brightness is higher at the narrow viewing angle, and the display is clearer. Of course, it can be understood that due to the effect of the reflective layer 120, there is also more front light at the wide viewing angle, so the front view is better in the second display mode. However, relatively speaking, the thermochromic unit 131 only absorbs light at a large angle, and the thermochromic unit 131 also has a certain reflective effect, so more light is emitted from between adjacent thermochromic units 131, increasing the amount of light at the narrow viewing angle, making the brightness at the narrow viewing angle greater than that at the wide viewing angle.

[0059] In this design, in addition to the heating section 141, a cooling section 142 is also provided. The main function of the cooling section 142 is to be controlled by the temperature controller 150 to ensure that the corresponding thermochromic section 131 reaches a preset temperature. The temperature of the thermochromic section 131 is controlled by the flexible combination of the heating section 141 and the cooling section 142. In this embodiment, the driving methods of the multiple heating sections 141 and multiple cooling sections 142 include, but are not limited to, individual driving, partition driving, or simultaneous driving. The temperature controller 150 controls the thermochromic film layer 130 by controlling the heating section 141 to uniformly heat or cool it. The heating section 141 and the cooling section 142 are both transparent electrothermal film layers 140; the heating section 141 is a hot film, and the cooling section 142 is a cold film. Specifically, the polyimide electrothermal film is the main material of the cold film, and the polyethylene terephthalate electrothermal film is the main material of the hot film. The heating and cooling of the thermochromic part 131 are achieved by controlling the energization of the above materials.

[0060] This embodiment of the application further includes a thermally conductive film layer 151 in the temperature controller 150. The function of the thermally conductive film layer 151 is to conduct heat, and it is made of a metal material that easily conducts heat, such as aluminum or copper. One end of the thermally conductive film layer 151 is connected to the light source, and the other end of the thermally conductive film layer 151 is connected to the heating part 141, transferring the heat from the light source to the heating part 141.

[0061] Since LEDs in the light source tend to generate a lot of heat when emitting light, how to effectively dissipate heat from the light-emitting unit is also an important direction in this field. In this embodiment, the heat generated by the LED can be transferred to the electrothermal film using the thermally conductive film layer 151. This can effectively dissipate heat from the light source, recover and utilize the heat, and supplement the heat provided by the heating unit 141 and the temperature controller 150, thereby reducing the power consumption of the temperature controller 150.

[0062] In practical use, the heat-conducting film layer 151 first transfers the heat from the light source to the heating film. The temperature sensing layer in the temperature controller 150 monitors the temperature of the heating section 141 caused by the heat-conducting film layer 151. If insufficient heat is detected, power can be supplied to the heating section 141 to further increase the temperature of the heating section 141 so that the thermochromic section 131 reaches the preset temperature.

[0063] In this embodiment, the heating section 141 and the cooling section 142 can be arranged alternately. For example, at the same position of the thermochromic section 131, multiple connected heating sections 141 and multiple connected cooling sections 142 can be arranged alternately.

[0064] Figure 7 This is a schematic diagram of another electrothermal film layer of this application, see [link / reference]. Figure 7 As shown, the cooling section 142 is circular, and the heating section 141 is annular. The heating section 141 is arranged around the cooling section 142, making the area of ​​the cooling section 142 larger and directly opposite the position of the thermochromic section 131. The heating section 141 corresponds to the edge position of the thermochromic section 131. In this embodiment, by setting the heating section 141 and cooling section 142 evenly, the temperature change at each position of the corresponding thermochromic section 131 is more uniform.

[0065] Figure 8 This is a schematic diagram of the display device of this application, see below. Figure 8 As shown, this application discloses a display device, specifically a display device 200, which includes a display panel 210 and the aforementioned backlight module 100, wherein the backlight module 100 provides a light source for the display panel.

[0066] The display panel can be any type of display panel, 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, or other types of display panels, such as Mini-LED and OLED display panels, all of which are applicable to the above solutions.

[0067] This application incorporates a reflective section 121 and a thermochromic section 131, with the thermochromic section 131 and the reflective section 121 arranged correspondingly. On one hand, the thermochromic section 131 absorbs heat, allowing it to switch between an opaque and transparent state, thus enabling switching between narrow and wide viewing angles. During the heat absorption process of the thermochromic section 131, the temperature of the backlight module 100 can be reduced, achieving temperature regulation and facilitating heat dissipation. On the other hand, the reflective section 121, corresponding to the thermochromic section 131, reflects most of the light incident on the thermochromic section 131 back to the backlight source, which then emits light from between the thermochromic sections 131, thereby enhancing the brightness of the display panel. When the display panel is used for automotive displays, the temperature rises due to external ambient light such as direct sunlight. The thermochromic part 131 absorbs heat to reduce the overall heat of the display panel. When the temperature reaches a preset temperature, the thermochromic part 131 becomes transparent, achieving a wide viewing angle. When the temperature is below the preset temperature, the thermochromic part 131 is opaque, achieving a narrow viewing angle. Especially at narrow viewing angles, due to the reflective part 121, most of the light rays at large angles and those not being displayed can be collected and re-emitted without increasing the driving voltage, greatly improving the brightness of the narrow viewing angle display and enhancing the automotive display effect. Furthermore, the first and second display modes can be controlled through the electro-controlled film layer, allowing the display panel to be cooled by the cooling film in the electrothermal film layer 140 when it is hot.

[0068] It should be noted that the inventive concept of this application can form many embodiments, but due to the limited space of the application documents, they cannot all be listed. Therefore, without conflict, the embodiments described above or the technical features can be arbitrarily combined to form new embodiments. After the embodiments or technical features are combined, the original technical effect will be enhanced.

[0069] The above description, in conjunction with specific optional embodiments, provides a further detailed explanation of this application and should not be construed as limiting the specific implementation of this application to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of this application, and all such modifications or substitutions should be considered within the scope of protection of this application.

Claims

1. A backlight module configured to provide backlight for a display panel, the backlight module comprising: Comprising: A backlight source for providing light source for the backlight module; A reflective layer provided with a plurality of reflection portions, uniformly arranged on the backlight source, and the reflection portions are used for reflecting the light rays emitted from the backlight source into the reflective layer; and A thermochromic film layer provided on the reflective layer, including a plurality of thermochromic portions, and the plurality of thermochromic portions are correspondingly arranged with the plurality of reflection portions; Wherein, when the thermochromic portion is below a preset temperature, the thermochromic portion is in a non-transparent state, and the display panel is in a first display mode; when the thermochromic portion is not lower than the preset temperature, the thermochromic portion is in a transparent state, and the display panel is in a second display mode; The viewing angle of the first display mode is smaller than that of the second display mode, and the brightness of the first display mode is higher than that of the second display mode; The backlight module further includes an electrothermal film layer provided on the thermochromic film layer for controlling the temperature transmitted to the thermochromic film layer; Wherein, when the electrothermal film layer is lower than the preset temperature, the thermochromic portion is in a non-transparent state, the display panel is in a first display mode, and the light rays emitted from the backlight source are emitted from between adjacent thermochromic portions; when the electrothermal film layer is greater than or equal to the preset temperature, the thermochromic portion is in a transparent state, and the display panel is in a second display mode; The electrothermal film layer includes a plurality of heating portions and a plurality of cooling portions, and one thermochromic portion is correspondingly arranged with one heating portion and one cooling portion respectively; the cooling portion is circular, the heating portion is annular, and the heating portion surrounds the cooling portion; The backlight module further includes a temperature controller for controlling the heating portion or the cooling portion to heat or cool the thermochromic portion.

2. The backlight module of claim 1, wherein, The display panel includes an opening area and a non-opening area, the backlight module includes a light-emitting area and a non-light-emitting area, the light-emitting area corresponds to the opening area, and the non-light-emitting area corresponds to the non-opening area; A plurality of the reflection portions are provided in the non-light-emitting area; a plurality of the thermochromic portions are provided in the non-light-emitting area; The reflection portion is used for reflecting the light rays emitted from the backlight source into the non-light-emitting area.

3. The backlight module of claim 2, wherein, The thermochromic portion is strip-shaped, and a plurality of the thermochromic portions are arranged in an array, and there is a gap between adjacent two thermochromic portions.

4. The backlight module of claim 2, wherein, The opening area includes a plurality of sub-pixel areas, the thermochromic portion surrounds one or more of the sub-pixel areas, and the thermochromic portion is in a shape of a rectangle with a hole in the middle; adjacent two thermochromic portions are in direct contact.

5. The backlight module according to claim 3 or 4, characterized in that, The shapes and numbers of the reflection portion and the thermochromic portion are the same, and they are correspondingly arranged one by one; The thickness of the reflection portion is less than the thickness of the thermochromic portion, and the thickness of the thermochromic portion is not less than 2um.

6. The backlight module of claim 1, wherein, The reflection portion is formed of porous silicon material; The thermochromic film layer is a composite material at least including polymethyl methacrylate (PMMA), polyvinylidene fluoride (PVDF), polycaprolactone (PCL) and silicon dioxide (SiO2); 7. The backlight module of claim 1, wherein, The backlight module is a side-entry backlight module or a direct-lit backlight module; The side-in backlight module comprises a light bar and a light guide plate, the light guide plate is used to provide a surface light source for a display panel, has a first surface, a second surface and a light-in surface, the first surface is a light-out surface, the light-in surface connects the first surface and the second surface; the light bar is arranged on the light-in surface of the light guide plate and is used to provide a line light source for the light guide plate, and the reflection layer is arranged on the second surface of the light guide plate. The direct backlight module comprises a bottom plate, a reflection sheet and a plurality of lamp beads, the plurality of lamp beads are arranged in an array on the bottom plate, the reflection sheet is arranged on one side of the bottom plate provided with the lamp beads, the reflection sheet is provided with openings corresponding to positions of the plurality of lamp beads, and the lamp beads are arranged on the bottom plate after penetrating through the reflection sheet; one lamp bead is provided with one reflection part on at least one side.

8. A display device, characterized by comprising: The display device comprises a display panel and the backlight module according to any one of claims 1-7, and the backlight module provides a light source for the display panel.

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