Backlight module and display device

Abstract

Embodiments of the present application provide a backlight module and a display device, and relate to the technical field of display. In the backlight module, at least one light bar is arranged on the side of a light guide plate. The bottom plate of the back plate is arranged on the non-light-emitting surface of the light guide plate, the side plate is connected with the bottom plate and is located on the side of the light bar away from the light guide plate, and the top plate is connected with the side plate and is located on the side of the light bar away from the bottom plate. The light bar comprises a first frame and an infrared light-emitting device, the surface of the first frame close to the light guide plate is provided with a first groove, and the infrared light-emitting device is arranged in the first groove. In the first direction perpendicular to the light-emitting surface, the first groove comprises opposite first and second side walls, and both the first and second side walls are inclined towards the direction close to the top plate relative to the bottom plate. The minimum included angle between the first side wall and the light-emitting surface ranges from 30° to 70°, and the minimum included angle between the second side wall and the light-emitting surface ranges from 30° to 70°. Based on this, the light-emitting efficiency of infrared light can be improved.

Description

Technical Field

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

[0002] Infrared light can activate mitochondria and provide energy, thereby promoting blood circulation and relieving eye strain. In display products, increasing infrared light emission can achieve eye-protection effects. However, in backlit display products, the light-emitting devices are usually located within the backlight module. The light emitted by these devices is conducted within a light guide plate, and then emitted after passing through film layers and the display panel. This process absorbs some infrared light, reducing its utilization rate and resulting in a poorer eye-protection effect in the final product. Utility Model Content

[0003] This application proposes a backlight module and display device, which aims to improve the light extraction efficiency of infrared light.

[0004] On the one hand, this application provides a backlight module, including a light guide plate, at least one light strip and a back plate.

[0005] The light guide plate includes opposing light-emitting and non-light-emitting surfaces, and a side surface connecting the light-emitting and non-light-emitting surfaces. At least one LED strip is disposed on the side surface of the light guide plate. The back plate includes a bottom plate, side plates, and a top plate, with the bottom plate disposed on the non-light-emitting surface of the light guide plate. The side plates are connected to the bottom plate and are located on the side of the LED strip away from the light guide plate. The top plate is connected to the side plates and is located on the side of the LED strip away from the bottom plate.

[0006] The light strip includes a first frame and an infrared light-emitting device. A first groove is provided on the surface of the first frame near the light guide plate, and the infrared light-emitting device is disposed in the first groove.

[0007] Along a first direction perpendicular to the light-emitting surface, the first groove includes opposing first and second sidewalls, both of which are inclined toward the top plate relative to the bottom plate. The minimum included angle between the first sidewall and the light-emitting surface ranges from 30° to 70°, and the minimum included angle between the second sidewall and the light-emitting surface also ranges from 30° to 70°.

[0008] Based on this, the infrared light emitted by the infrared light-emitting device will be emitted at an angle towards the side closer to the top plate. The infrared light does not need to be uniformly guided by a light guide plate. Along the inclined direction of the first and second side walls, the infrared light is emitted from the backlight module with a shorter propagation path. The infrared light reflects less and has a shorter propagation path in the light guide plate, which helps to reduce the absorption of infrared light by the light guide plate, improve the utilization rate and light emission efficiency of infrared light, and thus improve the eye protection effect of the corresponding product.

[0009] In some embodiments, the orthographic projection of the top plate onto the bottom plate partially overlaps with the orthographic projection of the first frame onto the bottom plate. Furthermore, along the second direction from the light strip to the light guide plate, the orthographic projection of the first frame onto the bottom plate extends beyond the orthographic projection of the top plate onto the bottom plate.

[0010] In some embodiments, the backlight module further includes a film layer disposed on the light-emitting surface of the light guide plate. The film layer extends to the side of the first frame away from the base plate.

[0011] In some embodiments, the backlight module includes multiple light strips, including a first light strip and a second light strip. The first light strip includes an infrared light-emitting device, and the second light strip includes a white light-emitting device. The light guide plate includes multiple sides, and the first light strip and the second light strip are located on different sides of the light guide plate.

[0012] In some embodiments, the orthographic projection of the top plate onto the bottom plate covers the orthographic projection of the second light strip onto the bottom plate.

[0013] In some embodiments, the light strip further includes a second frame and a white light-emitting device. A second groove is provided on the surface of the second frame near the light guide plate, and the white light-emitting device is disposed in the second groove.

[0014] In some embodiments, the minimum distance between the first frame and the side of the light guide plate is equal to the minimum distance between the second frame and the side of the light guide plate.

[0015] In some embodiments, the light strip includes a plurality of infrared light-emitting devices and a plurality of white light-emitting devices. The white light-emitting devices are located at both ends of the light strip along its extension direction. Between the white light-emitting devices at both ends, at least one infrared light-emitting device and at least one white light-emitting device are alternately arranged.

[0016] In some embodiments, the light strip further includes an infrared driving circuit and a white light driving circuit, wherein the infrared light-emitting device is electrically connected through the infrared driving circuit and the white light-emitting device is electrically connected through the white light driving circuit.

[0017] In some embodiments, the light guide plate includes a display area and a light mixing area, the light mixing area being located on the side of the display area closer to the light strip.

[0018] The minimum distance between the second frame and the boundary of the mixing area near the display area is called the first distance. The distance between the centers of two white light-emitting devices located on both sides of an infrared light-emitting device along the extension direction of the light strip is called the second distance. The ratio between the first distance and the second distance is greater than or equal to 1.

[0019] In some embodiments, the infrared light-emitting device includes an infrared LED chip configured to emit infrared light.

[0020] Alternatively, the infrared light-emitting device includes a blue LED chip and an infrared phosphor, with the infrared phosphor located on the side surface of the blue LED chip near the light guide plate.

[0021] Alternatively, the infrared light-emitting device includes a blue LED chip and an infrared quantum dot material layer, with the infrared quantum dot material layer located on the side of the blue LED chip closest to the light guide plate. The material of the infrared quantum dot material layer includes lead chalcogenide quantum dots, mercury chalcogenide quantum dots, or silver indium chalcogenide quantum dots.

[0022] Alternatively, the infrared light-emitting device includes a blue LED chip and an infrared perovskite material layer, with the infrared perovskite material layer located on the side of the blue LED chip closest to the light guide plate. The material of the infrared perovskite material layer can be lead-based perovskite, tin-based perovskite, or a double perovskite.

[0023] In some embodiments, the backlight module further includes a film layer disposed on the light-emitting surface of the light guide plate.

[0024] The film layer includes a diffuser sheet and a prism sheet stacked together, with the prism sheet located on the side of the diffuser sheet away from the light guide plate.

[0025] The film layer also includes an infrared material layer, which is located between the light guide plate and the diffuser. And / or, the infrared material layer is located between the diffuser and the prism sheet. And / or, the infrared material layer is located on the side of the prism sheet furthest from the diffuser.

[0026] In some embodiments, the infrared material layer may be made of infrared phosphor, infrared quantum dot material, or infrared perovskite material.

[0027] On the other hand, this application also provides a display device, including a backlight module, a display panel, and a cover plate as described in any of the embodiments of the first aspect. The display panel is located on the side of the backlight module's film layer away from the light guide plate. The cover plate is located on the side of the display panel away from the backlight module.

[0028] In some embodiments, the display device further includes an infrared phosphor material layer.

[0029] An infrared phosphor material layer is located on the surface of the display panel closest to the backlight module. And / or, an infrared phosphor material layer is located on the surface of the display panel furthest from the backlight module. And / or, an infrared phosphor material layer is located on the surface of the cover plate closest to the display panel. And / or, an infrared phosphor material layer is located on the surface of the cover plate furthest from the display panel. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in this application, the accompanying drawings used in some embodiments of this application will be briefly described below. Obviously, the drawings described below are only drawings of some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams and are not actual dimensions of the products or actual processes of the methods involved in the embodiments of this application.

[0031] Figure 1 This application provides a schematic diagram of the structure of a backlight module; Figure 2 for Figure 1 A magnified view of a portion of the backlight module at the infrared light-emitting device; Figure 3 This is a schematic diagram of another backlight module provided in this application; Figure 4 for Figure 3 The diagram shows the driving circuit schematic of the display module. Figure 5 A schematic diagram of another infrared light-emitting device provided in this application; Figure 6 A structural schematic diagram of another backlight module provided in this application; Figure 7 This is a schematic diagram of the structure of a display device provided in this application. Detailed Implementation

[0032] The technical solutions in some embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments provided in this application are within the scope of protection of this application.

[0033] Unless the context otherwise requires, throughout the specification and claims, the term "comprising" is interpreted as open and encompassing, that is, "including, but not limited to".

[0034] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this application, unless otherwise stated, "a plurality of" means two or more.

[0035] In describing some embodiments, the term "connection" and its derivative expressions may be used. The term "connection" should be interpreted broadly; for example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection through an intermediate medium. For example, in describing some embodiments, the term "connection" may be used to indicate that two or more components have direct physical or electrical contact with each other.

[0036] In addition, the use of “based on” implies openness and inclusivity, because processes, steps, calculations or other actions “based on” one or more of the stated conditions or values ​​may in practice be based on additional conditions or values ​​beyond those stated.

[0037] It should be understood that when a layer or element is referred to as being on another layer or substrate, it can mean that the layer or element is directly on the other layer or substrate, or that there is an intermediate layer between the layer or element and the other layer or substrate.

[0038] This document describes exemplary embodiments with reference to cross-sectional views, which are intended as idealized exemplary drawings. In the drawings, the thickness of the layers and the area of ​​the regions are enlarged for clarity. Therefore, variations in shape relative to the drawings are contemplated due to, for example, manufacturing techniques and / or tolerances. Thus, exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but rather include shape deviations caused, for example, by manufacturing processes. For example, etched areas shown as rectangular would typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to show the actual shapes of the areas of the device, nor are they intended to limit the scope of the exemplary embodiments.

[0039] In display products, taking mobile phones as an example, prolonged use can cause eye strain. Eye-protection displays address this by increasing infrared light emission. Infrared light activates mitochondria, providing energy and promoting blood circulation, thus alleviating eye strain and achieving an eye-protection effect. However, due to limitations in product design, some of the infrared light emitted by the light-emitting device is absorbed by the light guide plate during transmission, significantly reducing the light emission efficiency and affecting the product's eye-protection effect.

[0040] Based on this, this application provides a backlight module, such as Figures 1-2 As shown, Figure 1 This is a structural schematic diagram of a backlight module provided in this application. Figure 2 for Figure 1 The image shows a magnified view of a portion of the backlight module at the infrared light-emitting device.

[0041] like Figure 1 As shown, the backlight module 10 includes a light guide plate 11, at least one light strip 12, and a back plate 13.

[0042] The light guide plate 11 includes opposing light-emitting surfaces P1 and P2, and a side surface connecting the light-emitting surfaces P1 and P2. At least one LED strip 12 is disposed on the side surface of the light guide plate 11. The back plate 13 includes a bottom plate 131, a side plate 132, and a top plate 133. The bottom plate 131 is disposed on the non-light-emitting surface P2 of the light guide plate 11. The side plate 132 is connected to the bottom plate 131 and is located on the side of the LED strip 12 away from the light guide plate 11. The top plate 133 is connected to the side plate 132 and is located on the side of the LED strip 12 away from the bottom plate 131. That is, the back plate 13 is disposed around the LED strip 12 and the non-light-emitting surface P2 of the light guide plate 11, providing support and protection for the light guide plate 11 and the LED strip 12.

[0043] The light strip 12 includes a first frame 21 and an infrared light-emitting device 22. A first groove T1 is provided on the surface of the first frame 21 near the light guide plate 11, and the infrared light-emitting device 22 is disposed in the first groove T1. It can be understood that the first frame 21 is the support for the infrared light-emitting device 22, and the first frame 21 and the infrared light-emitting device 22 can be regarded as a whole. The infrared light emitted by the infrared light-emitting device 22 exits from the first groove T1.

[0044] like Figure 2 As shown, along the first direction Z perpendicular to the light-emitting surface P1, the first groove T1 includes a first sidewall C1 and a second sidewall C2, both of which are inclined towards the top plate 133 relative to the bottom plate 131. That is, as Figure 2 As shown, the first sidewall C1 is located on the side of the second sidewall C2 near the top plate 133. Let the side of the first groove T1 used to house the infrared light-emitting device 22 be its bottom surface. Then, within the first groove T1, the angle between this bottom surface and the second sidewall C2 is acute, and the angle between this bottom surface and the first sidewall C1 is obtuse. Based on this, the infrared light emitted by the infrared light-emitting device 22 can be directed towards the side closer to the top plate 133.

[0045] The minimum angle between the first sidewall C1 and the light-emitting surface P1 ranges from 30° to 70°, for example, 30°, 35°, 40°, 45°...70°. The minimum angle between the second sidewall C2 and the light-emitting surface P1 also ranges from 30° to 70°, for example, 30°, 35°, 40°, 45°...70°.

[0046] For example, such as Figure 2 As shown, in some embodiments, the thickness H1 of the edge position of the first frame 21 located near the top plate 133 of the first groove T1 ranges from 0.1mm to 1.0mm, and the thickness H2 of the edge position of the first groove T1 located near the bottom plate 131 ranges from 2mm to 4mm.

[0047] Combination Figure 1 As shown in the optical path L, the infrared light emitted by the infrared light-emitting device 22 does not require uniform light guiding by the light guide plate 11. The infrared light will be emitted from the backlight module 10 along the inclined direction of the first sidewall C1 and the second sidewall C2 with a shorter propagation path. The fewer times the infrared light is reflected in the light guide plate 11 and the shorter the propagation path, the more beneficial it is to reduce the absorption of infrared light by the light guide plate 11. This is also beneficial to improve the utilization rate of the infrared light emitted by the infrared light-emitting device 22, ensuring that more infrared light is emitted from the backlight module 10, improving the light emission efficiency of infrared light, and thus improving the eye protection effect of the corresponding product.

[0048] The angle range between the first sidewall C1 and the second sidewall C2 constrains the infrared light emission angle, affecting both the emission efficiency and uniformity of the infrared light. For example, the larger the minimum angle between the first sidewall C1 and the light-emitting surface P1, the closer the infrared light emission range is to the side of the light guide plate 11, which is detrimental to improving the uniformity of infrared light emission. Therefore, the upper limit of the minimum angle between the first sidewall C1 and the light-emitting surface P1 is limited to 70°. Similarly, the upper limit of the minimum angle between the second sidewall C2 and the light-emitting surface P1 is also limited to 70°. Conversely, the smaller the minimum angle between the first sidewall C1 and the light-emitting surface P1, the more propagation paths and reflections the infrared light undergoes within the light guide plate 11, which is detrimental to improving the infrared light emission efficiency. Therefore, the lower limit of the minimum angle between the first sidewall C1 and the light-emitting surface P1 is limited to 30°. Similarly, the lower limit of the minimum angle between the second sidewall C2 and the light-emitting surface P1 is also limited to 30°.

[0049] Therefore, both the light emission efficiency and uniformity of infrared light can be taken into account. During user operation, based on the effects of infrared light, it can inhibit axial elongation, relax ciliary muscles, promote blood circulation in the eyes, enhance mitochondrial function, relieve eye fatigue, reduce falsely high myopia, and prevent eye diseases, thereby achieving the effect of protecting vision and protecting the display.

[0050] In some embodiments, such as Figure 1 and Figure 2 As shown, the orthographic projection of the top plate 133 onto the bottom plate 131 overlaps with the orthographic projection of the first frame 21 onto the bottom plate 131. Furthermore, along the second direction X from the light strip 12 to the light guide plate 11, the orthographic projection of the first frame 21 onto the bottom plate 131 exceeds the orthographic projection of the top plate 133 onto the bottom plate 131.

[0051] For example, the top plate 133 is shortened by 1mm to 2mm towards the side plate 132 compared to the side boundary of the first frame 21 near the light guide plate 11.

[0052] In some embodiments, such as Figure 1As shown, the backlight module 10 also includes a film layer 14, which is disposed on the light-emitting surface P1 of the light guide plate 11. The film layer 14 extends to the side of the first frame 21 away from the base plate 131.

[0053] Combination Figure 1 The optical path L can be understood as follows: with the inclined design of the first sidewall C1 and the second sidewall C2, the infrared light emitted by the infrared light-emitting device 22 is closer to the edge of the backlight module 10, that is, closer to the top plate 133. The shortening of the top plate 133 towards the side plate 132 helps to prevent the top plate 133 from reflecting the infrared light back into the light guide plate 11, thereby avoiding increasing the number of reflections and propagation paths of the infrared light in the light guide plate 11, reducing the absorption of infrared light by the light guide plate 11, and thus improving the infrared light extraction efficiency.

[0054] like Figure 1 As shown, the backlight module 10 also includes an adhesive tape 30, which is bonded to the top plate 133 and the membrane layer 14 to enhance the adhesion between the membrane layer 14 and the top plate 133, secure the backlight module 10, and prevent the membrane layer 14 from shaking or falling off. In some embodiments, the adhesive tape 30 also has a light-shielding effect to prevent light leakage from the backlight module 30.

[0055] Based on the shortening of the top plate 133 towards the side plate 132, the membrane layer 14 extends towards the side plate 132 to cover the first frame 21 that extends beyond the coverage area of ​​the top plate 133. On the one hand, this helps to reduce the gap between the membrane layer 14 and the top plate 133, which helps to ensure the adhesion effect of the tape 30 and ensures that the membrane layer 14 will not shake or fall off. On the other hand, compared with the gap, the reflection and refraction of infrared light by the membrane layer 14 also helps to allow the infrared light in this range to be re-emitted. That is, by using the membrane layer 14 to fill the gap and by reflecting and refracting the light in this range, it also helps to improve the utilization rate of infrared light and improve the infrared light output rate of the backlight module 10.

[0056] In some embodiments, such as Figure 1 As shown, the backlight module 10 includes multiple light strips 12, including a first light strip 121 and a second light strip 122. The first light strip 121 includes an infrared light-emitting device 22, and the second light strip 122 includes a white light-emitting device 24. The light guide plate 11 includes multiple sides, and the first light strip 121 and the second light strip 122 are located on different sides of the light guide plate 11.

[0057] In some embodiments, such as Figure 1 As shown, the orthographic projection of the top plate 133 onto the bottom plate 131 covers the orthographic projection of the second light strip 122 onto the bottom plate 131.

[0058] Figure 1The diagram illustrates the first LED strip 121 and the second LED strip 122 located on opposite sides of the light guide plate 11. It can be understood that the first LED strip 121 and the second LED strip 122 can also be located on adjacent sides of the light guide plate 11, and their positional relationship is not limited. Furthermore, the backlight module 10 can also be configured to have LED strips 12 on three or four sides of the light guide plate 11.

[0059] In this embodiment of the application, the first light strip 121 includes multiple infrared light-emitting devices 22, and the second light strip 122 includes multiple white light-emitting devices 24. That is, the infrared light-emitting devices 22 and the white light-emitting devices 24 are set separately. Regardless of whether the size and specifications of the infrared light-emitting devices 22 and the white light-emitting devices 24 are the same, it can be guaranteed that the light-emitting devices on the same light strip have the same specifications and size. This is conducive to achieving a neat design and improving the aesthetics of the process.

[0060] The separate arrangement of the infrared light-emitting device 22 and the white light-emitting device 24 ensures that the placement of the infrared light-emitting device 22 does not affect the light emission display effect of the white light-emitting device 24, nor does it disrupt the light emission uniformity of the white light-emitting device 24. On the side near the first light strip 121, the top plate 133 is shortened to ensure the light emission efficiency of the infrared light and prevent the top plate 133 from reflecting the infrared light back into the light guide plate 11. On the side near the second light strip 122, the top plate 133 can still adopt a conventional design to ensure that the white light can be uniformly transmitted within the light guide plate 11, guaranteeing display uniformity.

[0061] In some embodiments, such as Figure 3 As shown, Figure 3 This is a schematic diagram of another backlight module provided in this application.

[0062] Combination Figure 1 and Figure 3 As shown, the light strip 12 also includes a second frame 23 and a white light-emitting device 24. A second groove T2 is provided on the surface of the second frame 23 near the light guide plate 11, and the white light-emitting device 24 is disposed in the second groove T2. It can be understood that the second groove T2 can be a rectangular groove or a flared groove facing the side of the light guide plate 11 to ensure that the white light can be uniformly guided by the light guide plate 11.

[0063] In this embodiment, the infrared light-emitting device 22 and the white light-emitting device 24 are disposed on the same light strip 12. The backlight module 10 can be configured with only one light strip 12 to simultaneously emit visible light and infrared light, thus achieving eye-protection display. Based on this, it is beneficial to reduce the production cost of eye-protection display.

[0064] Figure 3Taking the example of setting a light strip 12 on one side of the light guide plate 11, it can be understood that the light strip 12 can also be set on multiple sides of the light guide plate 11 (that is, multi-side light incident scheme). The multi-side light incident scheme reduces the distance difference between different display positions and the nearest light-emitting device, which is beneficial to improving the uniformity of light emission.

[0065] In some embodiments, such as Figure 3 As shown, the minimum distance between the first frame 21 and the side of the light guide plate 11 is equal to the minimum distance between the second frame 23 and the side of the light guide plate 11.

[0066] For example, due to the size design limitations of the infrared light-emitting device 22, there may be cases where the outer contour dimensions of the first frame 21 and the second frame 23 are different. In this embodiment, regardless of whether the two dimensions are the same, the infrared light-emitting device 22 and the white light-emitting device 24 are designed to have their light-emitting surfaces flush, ensuring that there is no gap between the light-emitting surface and the light guide plate 11, thereby avoiding light leakage.

[0067] In some embodiments, such as Figure 3 As shown, the light strip 12 includes a plurality of infrared light-emitting devices 22 and a plurality of white light-emitting devices 24. Along the extending direction of the light strip 12, the white light-emitting devices 24 are located at both ends of the light strip 12. Between the white light-emitting devices 24 at both ends, at least one infrared light-emitting device 22 and at least one white light-emitting device 24 are alternately arranged.

[0068] For example, the alternating arrangement of infrared light-emitting device 22 and white light-emitting device 24 is such that one infrared light-emitting device 22 and one white light-emitting device 24 form a minimum repeating unit, or one infrared light-emitting device 22 and two white light-emitting devices 24 form a minimum repeating unit.

[0069] For example, in one embodiment, the light strip 12 includes a total of 51 light-emitting devices, with one infrared light-emitting device 22 and one white light-emitting device 24 arranged alternately. Two white light-emitting devices 24 are provided at each end of the two infrared light-emitting devices 22 located at the two outermost ends. That is, along the extension direction of the light strip 12, the first and second are white light-emitting devices 24, the third is an infrared light-emitting device 22, the fourth is a white light-emitting device 24, the fifth is an infrared light-emitting device 22, and so on, with the forty-eighth being a white light-emitting device 24, the forty-ninth being an infrared light-emitting device 22, and the fiftieth and fifty-first being white light-emitting devices 24.

[0070] It is understandable that the infrared light emitted by the infrared light-emitting device 22 is invisible. In the scheme where the infrared light-emitting device 22 and the white light-emitting device 24 are arranged alternately, the placement of the infrared light-emitting device 22 increases the spacing between the two white light-emitting devices 24 on both sides. This may result in dark areas in the region corresponding to the infrared light-emitting device 22. The periodic alternation of the infrared light-emitting device 22 and the white light-emitting device 24 helps ensure the uniformity and intensity of the infrared and white light output, avoiding excessive contrast between areas with concentrated infrared light-emitting devices 22 and areas with concentrated white light-emitting devices 24, which would affect the display effect. Similarly, having the same number of white light-emitting devices 24 at both ends of the light strip 12 helps ensure the uniformity of white light output on both sides. The fact that the number of white light-emitting devices 24 is greater than the number of red light-emitting devices 22 helps ensure a better display effect.

[0071] In some embodiments, such as Figure 4 As shown, Figure 4 for Figure 3 The diagram shows the driving circuit schematic of the display module.

[0072] When the infrared light-emitting device 22 and the white light-emitting device 24 are arranged in the same light strip 12, the light strip 12 also includes an infrared driving circuit and a white light driving circuit. The infrared light-emitting device 22 is electrically connected through the infrared driving circuit, and the white light-emitting device 24 is electrically connected through the white light driving circuit.

[0073] It is understandable that the light strip 12 includes a flexible circuit board, and the infrared driving circuit and the white light driving circuit are both power supply circuits located on the flexible circuit board.

[0074] like Figure 4 As shown, in conjunction with the embodiment mentioned above where the light strip 12 includes a total of 51 light-emitting devices, R1 corresponds to the first light-emitting device (i.e., the white light-emitting device), R3 corresponds to the third light-emitting device (i.e., the infrared light-emitting device), and so on.

[0075] In this embodiment, the 27 white light-emitting devices 24 are divided into three series circuits, with nine white light-emitting devices 24 connected in series in each circuit. The positive terminals of all three series circuits are electrically connected to the first positive terminal A1+ on the power management integrated chip (Power IC) via pin PIN1 on the flexible circuit board. The negative terminals of the three series circuits are respectively connected to the negative terminals A1-, A3-, and A5- on the power management integrated chip (Power IC) via pins PIN6, PIN8, and PIN10 on the flexible circuit board. By adjusting the electrical signal between the first positive terminal A1+ and its corresponding negative terminals (including negative terminals A1-, A3-, and A5-) of the power management integrated chip, the brightness of the white light-emitting devices 24 in the backlight module 10 can be controlled, thereby adjusting the display brightness of the corresponding product.

[0076] Similarly, the 24 infrared light-emitting devices 22 are divided into three series circuits, with eight infrared light-emitting devices 22 connected in series in each circuit. The positive terminals of all three series circuits are electrically connected to the second positive terminal B2+ on the power management integrated chip via pin PIN2 on the flexible circuit board. The negative terminals of the three series circuits are electrically connected to the corresponding negative terminals B2-, B4-, and B6- on the power management integrated chip via pins PIN7, PIN9, and PIN11 on the flexible circuit board, respectively. By adjusting the electrical signal between the second positive terminal B2+ and its corresponding negative terminals (including negative terminals B2-, B4-, and B6-) of the power management integrated chip, the luminous intensity of the infrared light-emitting devices 22 in the backlight module 10 can be controlled, thereby adjusting the eye protection effect of the corresponding product.

[0077] In this application, the separate driving scheme of the infrared light-emitting device 22 and the white light-emitting device 24 ensures that the emission intensity of the infrared light is independent of the display brightness. Both can be adjusted independently. At low display brightness, the driving signal of the white light driving circuit is weaker, but the infrared driving circuit still has a strong driving signal, ensuring that the emitted infrared light is within the human eye's reception threshold range. The same principle applies at high display brightness. Therefore, this approach helps to balance display performance and eye protection, avoiding the difficulty in guaranteeing eye protection at low display brightness.

[0078] In some embodiments, such as Figure 3 As shown, the light guide plate 11 includes a display area AA and a light mixing area Q1, with the light mixing area Q1 located on the side of the display area AA closest to the light strip 12.

[0079] The minimum distance between the second frame 23 and the side boundary of the mixing area Q1 near the display area AA is denoted as the first distance D1. The distance between the centers of the two white light-emitting devices 24 located on both sides of an infrared light-emitting device 22 along the extension direction of the light strip 12 is denoted as the second distance D2. The ratio between the first distance D1 and the second distance D2 is greater than or equal to 1.

[0080] As mentioned earlier, the infrared light emitted by the infrared light-emitting device 22 is invisible. In the scheme where the infrared light-emitting device 22 and the white light-emitting device 24 are arranged alternately, the arrangement of the infrared light-emitting device 22 increases the spacing between the two white light-emitting devices 24 on both sides. This may result in a dark area in the region corresponding to the infrared light-emitting device 22. Therefore, the length of the mixing area Q1 of the light guide plate 11 along the second direction X needs to be increased accordingly to ensure effective diffusion and conduction of white light within the mixing area Q1, thus preventing a dark area in the display area AA. By setting D1 / D2≥1, the white light-emitting device 24 can be effectively diffused and conducted within the mixing area Q1, thereby ensuring that there is no dark area in the display area AA.

[0081] It is understandable that the arrangement of the infrared light-emitting device 22 increases the distance between the two white light-emitting devices 24 on either side, resulting in a larger length of the mixing area Q1 along the second direction X, and consequently, a larger product border. The second distance D2 is related to the number of infrared light-emitting devices 22 and also to the size of the infrared light-emitting devices 22 themselves. The size of the infrared light-emitting device 22 itself is related to its light-emitting principle.

[0082] In this application, the infrared light-emitting device 22 can be designed based on different light-emitting principles.

[0083] For example, the infrared light-emitting device 22 includes an infrared LED chip configured to emit infrared light. For instance, the quantum well (active layer) material of the infrared LED chip has a bandgap that falls in the infrared band, and the bandgap energy of the quantum well is less than 1.6 eV, thereby enabling the infrared LED chip to emit infrared light during carrier radiative recombination.

[0084] The infrared LED chip emits wavelengths in the range of 780nm to 3000nm. In this embodiment, through optimized design, the wavelength of the emitted infrared light can be controlled within the range of 780nm to 1500nm, thereby alleviating eye strain.

[0085] The infrared LED chip has a minimum size of 0.36mm*0.36mm, a driving current of 20mA~150mA, and a luminous efficiency of 10%~30%. The minimum size of this infrared LED chip is larger than that of a conventional white LED chip. Correspondingly, the minimum size of the first frame 21 is 3.0mm*0.85mm*0.6mm, which is larger than the size of the second frame 23.

[0086] Alternatively, the infrared light-emitting device 22 includes a blue LED chip and an infrared phosphor, with the infrared phosphor located on the surface of the blue LED chip near the light guide plate 11.

[0087] For example, typically, white light-emitting device 24 emits white light by setting red-green or yellow phosphors on a blue LED chip. In this embodiment, infrared phosphors are set on a blue LED chip, and the infrared phosphors are excited by light with a wavelength of 450nm~470nm (i.e., blue light), so that the emission wavelength of infrared light-emitting device 22 can reach the range of 780nm~3000nm. Based on this scheme, the size of infrared light-emitting device 22 is smaller, and it can achieve the same size design as white light-emitting device 24. For example, the particle size of blue LED chip is 10μm~100μm. Based on this, the first frame 21 and the third frame 23 can adopt the same outer contour size design, for example, both of them have an outer contour size of 2.6mm*0.6mm*0.5mm. When infrared light-emitting device 22 and white light-emitting device 24 are set together in the same light strip 12, it is easier to achieve neat arrangement. In the manufacturing process of backlight module 10, it is beneficial to avoid local gaps in backlight module 10 caused by the different sizes of the first frame 21 and the third frame 23, which would affect the function of the device. Furthermore, based on this scheme, the luminous efficiency of the infrared light-emitting device 22 can reach 10%~40%, the driving current is in the range of 18mA~23mA, and the power consumption is low, which is conducive to achieving energy-saving design.

[0088] Alternatively, the infrared light-emitting device 22 includes a blue LED chip and an infrared quantum dot material layer, with the infrared quantum dot material layer located on the side of the blue LED chip closest to the light guide plate 11. The infrared quantum dot material layer can be made of lead sulfide quantum dots, mercury sulfide quantum dots, or silver indium sulfide quantum dots. For example, among lead sulfide quantum dots, PbS quantum dots enable the infrared light-emitting device 22 to emit infrared light with wavelengths in the range of 800nm ​​to 2500nm, while PbSe quantum dots enable it to emit infrared light with wavelengths in the range of 1000nm to 4000nm. Among mercury sulfide quantum dots, HgTe quantum dots enable it to emit infrared light with wavelengths in the range of 1000nm to 5000nm. Among silver indium sulfide quantum dots, AgInS2 / ZnS core-shell quantum dots enable it to emit infrared light with wavelengths in the range of 700nm to 1200nm. This scheme allows for the rational selection of infrared quantum dot materials based on the required infrared wavelength range.

[0089] Alternatively, the infrared light-emitting device 22 includes a blue LED chip and an infrared perovskite material layer, with the infrared perovskite material layer located on the side of the blue LED chip closest to the light guide plate 11. The material of the infrared perovskite material layer includes lead-based perovskite, tin-based perovskite, or double perovskite. For example, in lead-based perovskite, FA... x MA 1-x PbI 3-y Br y CsPbI3 enables infrared light emission device 22 to emit infrared light in the wavelength range of 700nm to 1000nm, while MASnI3 enables it to emit infrared light in the wavelength range of 950nm to 1050nm. In tin-based perovskites, Cs2AgInCl6 enables infrared light emission device 22 to emit infrared light in the wavelength range of 650nm to 1100nm.

[0090] like Figure 5 As shown, Figure 5 This is a schematic diagram of another infrared light-emitting device provided in this application. A blue LED chip 221 is disposed on the bottom surface of the first groove T1. A first encapsulation layer 222, a material layer 223, and a second encapsulation layer 224 are sequentially disposed on the side of the blue LED chip 221 near the light guide plate 11. The material layer 223 is either an infrared quantum dot material or an infrared perovskite material layer. Both the infrared quantum dot material layer and the infrared perovskite material layer can give the infrared light-emitting device 22 a better infrared spectral waveform, a narrow half-wavelength, higher excitation efficiency of infrared light, and higher transmittance.

[0091] Since infrared quantum dot materials and infrared perovskite materials have poor stability, the first encapsulation layer 222 and the second encapsulation layer 224 can play a protective role, preventing water vapor or oxygen from entering, inhibiting ion migration, reducing light damage, and improving the service life of the infrared light-emitting device 22.

[0092] In some embodiments, such as Figure 6 As shown, Figure 6 This is a schematic diagram of another backlight module provided in this application.

[0093] The backlight module 10 also includes a film layer 14, which is disposed on the light-emitting surface P1 of the light guide plate 11.

[0094] The film layer 14 includes a diffuser sheet 141 and a prism sheet 142 stacked together, with the prism sheet 142 located on the side of the diffuser sheet 141 away from the light guide plate 11. The diffuser sheet 141 is used to diffuse light, further homogenizing and scattering it, reducing brightness unevenness and light spot phenomena, and making the light softer and more uniform. The prism sheet 142 is used to adjust the direction and distribution of light, converging the light in a specific direction, which helps to improve display brightness, improve viewing angle, and make the light emitted from the prism sheet 142 suitable for the display panel in the display device.

[0095] In this application, the film layer 14 also includes an infrared material layer 143. The light emitted from the light-emitting surface P1 of the light guide plate 11 is excited by the infrared material layer 143, resulting in higher uniformity of infrared light emission. Furthermore, the infrared light does not need to pass through the light guide plate 11, has a shorter propagation path, and suffers from lower infrared energy loss.

[0096] The infrared material layer 143 can be a single layer or multiple layers. The position of the infrared material layer 143 can be designed in various ways. For example, the infrared material layer 143 can be located between the light guide plate 11 and the diffuser 141, and / or, the infrared material layer 143 can be located between the diffuser 141 and the prism sheet 142, and / or, the infrared material layer 143 can be located on the side of the prism sheet 142 away from the diffuser 141.

[0097] For example, the infrared material layer 143 may be made of infrared phosphor, infrared quantum dot material, or infrared perovskite material. The selection of the infrared phosphor, infrared quantum dot material, or infrared perovskite material is as required above and will not be repeated here. It is understood that when the infrared material layer 143 includes infrared quantum dot material or infrared perovskite material, the infrared quantum dot material or infrared perovskite material needs to be encapsulated within an encapsulation layer for protection. The encapsulation layer material may be polymethyl methacrylate (PMMA).

[0098] On the other hand, this application also provides a display device, such as Figure 7 As shown, Figure 7This is a schematic diagram of the structure of a display device provided in this application.

[0099] like Figure 7 As shown, the display device 100 includes a backlight module 10, a display panel 101, and a cover plate 102 as described in any of the embodiments of the first aspect. The display panel 101 is located on the side of the backlight module 10 whose film layer 14 is away from the light guide plate 11. The cover plate 102 is located on the side of the display panel 101 away from the backlight module 10.

[0100] In this application, since the infrared light-emitting device 22 in the backlight module 10 adopts an inclined light emission scheme, based on the design that the first sidewall C1 and the second sidewall C2 are both inclined towards the top plate 133, the infrared light emitted by the infrared light-emitting device 22 does not need to be uniformly guided by the light guide plate 11. Instead, it will be emitted from the backlight module 10 along the inclined direction of the first sidewall C1 and the second sidewall C2 with a shorter propagation path, pass through the display panel 101 and the cover plate 102, and finally reach the human eye.

[0101] Infrared light undergoes fewer reflections and has a shorter propagation path within the light guide plate 11, reducing the absorption of infrared light by the light guide plate 11. This is beneficial for improving the utilization rate of infrared light emitted by the infrared light-emitting device 22, ensuring that more infrared light is emitted from the display device 100, resulting in higher infrared light emission efficiency and better eye protection.

[0102] In some embodiments, such as Figure 7 As shown, the display device 100 also includes an infrared phosphor material layer 103. The backlight module 10 typically includes a white light-emitting device 24. The white light emitted by the white light-emitting device 24 is conducted within the light guide plate 11 and finally emitted from the light-emitting surface P1 to ensure normal display function. By setting the infrared phosphor material layer 103, under normal display conditions, light passing through the infrared phosphor material layer 103 can excite infrared light, making the display device 100 emit infrared light uniformly. The infrared light uniformity is higher, and the infrared light does not need to pass through the light guide plate 11, resulting in a shorter propagation path and lower infrared energy loss.

[0103] The infrared phosphor material layer 103 can be a single layer or multiple layers, as long as the particle size is kept below 40μm and does not affect the display. There are various design options for the position of the infrared phosphor material layer 103. For example, the infrared phosphor material layer 103 can be located on the surface of the display panel 101 near the backlight module 10, and / or, the infrared phosphor material layer 103 can be located on the surface of the display panel 101 away from the backlight module 10, and / or, the infrared phosphor material layer 103 can be located on the surface of the cover plate 102 near the display panel 101, and / or, the infrared phosphor material layer 103 can be located on the surface of the cover plate 102 away from the display panel 101. Figure 7The following is an example of an infrared phosphor material layer 103 located on the side surface of the display panel 101 near the backlight module 10. Other solutions can be obtained by analogy, and will not be described in detail here.

[0104] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A backlight module, characterized in that, include: A light guide plate includes opposing light-emitting surfaces and non-light-emitting surfaces, as well as a side surface connecting the light-emitting surface and the non-light-emitting surface; At least one light strip is disposed on the side of the light guide plate; The backplate includes a bottom plate, a side plate, and a top plate. The bottom plate is disposed on the non-light-emitting surface of the light guide plate. The side plate is connected to the bottom plate and is located on the side of the light strip away from the light guide plate. The top plate is connected to the side plate and is located on the side of the light strip away from the bottom plate. The light strip includes a first frame and an infrared light-emitting device. A first groove is provided on the surface of the first frame near the light guide plate, and the infrared light-emitting device is disposed in the first groove. Along a first direction perpendicular to the light-emitting surface, the first groove includes a first sidewall and a second sidewall opposite to each other. Relative to the bottom plate, both the first sidewall and the second sidewall are inclined toward the top plate. The minimum included angle between the first sidewall and the light-emitting surface ranges from 30° to 70°, and the minimum included angle between the second sidewall and the light-emitting surface ranges from 30° to 70°.

2. The backlight module according to claim 1, characterized in that, The orthographic projection of the top plate onto the bottom plate overlaps with the orthographic projection of the first frame onto the bottom plate. Furthermore, along the second direction from the light strip to the light guide plate, the orthographic projection of the first frame on the base plate exceeds the orthographic projection of the top plate on the base plate.

3. The backlight module according to claim 2, characterized in that, The backlight module also includes a film layer, which is disposed on the light-emitting surface of the light guide plate; The membrane layer extends to the side of the first frame away from the base plate.

4. The backlight module according to claim 1, characterized in that, The backlight module includes multiple light strips, including a first light strip and a second light strip. The first light strip includes the infrared light-emitting device, and the second light strip includes a white light-emitting device. The light guide plate includes multiple sides, and the first light strip and the second light strip are located on different sides of the light guide plate.

5. The backlight module according to claim 4, characterized in that, The orthographic projection of the top plate onto the bottom plate covers the orthographic projection of the second light strip onto the bottom plate.

6. The backlight module according to claim 1, characterized in that, The light strip also includes a second frame and a white light-emitting device. A second groove is provided on the surface of the second frame near the light guide plate, and the white light-emitting device is disposed in the second groove.

7. The backlight module according to claim 6, characterized in that, The minimum distance between the first frame and the side of the light guide plate is equal to the minimum distance between the second frame and the side of the light guide plate.

8. The backlight module according to claim 6, characterized in that, The light strip includes multiple infrared light-emitting devices and multiple white light-emitting devices; Along the extension direction of the light strip, the white light-emitting device is located at both ends of the light strip; Between the white light-emitting devices at both ends, at least one infrared light-emitting device and at least one white light-emitting device are arranged alternately.

9. The backlight module according to claim 6, characterized in that, The light strip also includes an infrared driving circuit and a white light driving circuit. The infrared light-emitting device is electrically connected through the infrared driving circuit, and the white light-emitting device is electrically connected through the white light driving circuit.

10. The backlight module according to claim 6, characterized in that, The light guide plate includes a display area and a light mixing area, wherein the light mixing area is located on the side of the display area closer to the light strip; The minimum distance between the second frame and the side boundary of the light mixing area near the display area is denoted as the first distance. The distance between the centers of two white light-emitting devices located on both sides of an infrared light-emitting device along the extension direction of the light strip is denoted as the second distance. The ratio between the first distance and the second distance is greater than or equal to 1.

11. The backlight module according to claim 1, characterized in that, The infrared light-emitting device includes an infrared LED chip configured to emit infrared light; or... The infrared light-emitting device includes a blue LED chip and an infrared phosphor, wherein the infrared phosphor is located on the surface of the blue LED chip near the light guide plate; or, The infrared light-emitting device includes a blue LED chip and an infrared quantum dot material layer, wherein the infrared quantum dot material layer is located on the side of the blue LED chip closer to the light guide plate; the material of the infrared quantum dot material layer includes lead chalcogenide quantum dots, mercury chalcogenide quantum dots, or silver indium chalcogenide quantum dots; or, The infrared light-emitting device includes a blue LED chip and an infrared perovskite material layer. The infrared perovskite material layer is located on the side of the blue LED chip closer to the light guide plate. The material of the infrared perovskite material layer includes lead-based perovskite, tin-based perovskite, or double perovskite.

12. The backlight module according to claim 1, characterized in that, The backlight module also includes a film layer, which is disposed on the light-emitting surface of the light guide plate; The film layer includes a diffuser sheet and a prism sheet stacked together, with the prism sheet located on the side of the diffuser sheet away from the light guide plate; The film layer further includes an infrared material layer, which is located between the light guide plate and the diffuser sheet; and / or, the infrared material layer is located between the diffuser sheet and the prism sheet; and / or, the infrared material layer is located on the side of the prism sheet away from the diffuser sheet.

13. The backlight module according to claim 12, characterized in that, The infrared material layer may be made of infrared phosphors, infrared quantum dots, or infrared perovskite materials.

14. A display device, characterized in that, include: The backlight module as described in any one of claims 1 to 13; The display panel is located on the side of the backlight module's film layer away from the light guide plate; A cover plate is located on the side of the display panel away from the backlight module.

15. The display device according to claim 14, characterized in that, It also includes an infrared phosphor material layer; The infrared phosphor material layer is located on the side surface of the display panel closest to the backlight module; and / or, the infrared phosphor material layer is located on the side surface of the display panel furthest from the backlight module; and / or, the infrared phosphor material layer is located on the side surface of the cover plate closest to the display panel; and / or, the infrared phosphor material layer is located on the side surface of the cover plate furthest from the display panel.

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