Backlight module and display device

Abstract

The application relates to a backlight module and a display device. The backlight module comprises a back plate, the back plate comprises a plurality of grooves formed by inwardly recessing a plane part, a light-emitting unit is arranged in the groove and can be lifted along the depth direction of the groove, in a first state, the light-emitting unit is lower than the plane part or flush with the plane part, and in a second state, the light-emitting unit is higher than the plane part. According to the application, the grooves are arranged, the light-emitting unit moves up and down in the grooves, the viewing angle of the display device is changed, and when the display device is narrow-viewing-angle display, the user privacy can be protected.

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] In quantum dot light-emitting display devices, quantum dots emit fluorescence when excited by light to display images. These devices utilize nanoscale quantum dots for light emission, giving them advantages such as small size and simple manufacturing process.

[0003] However, as users become more aware of privacy protection, contemporary people have an increasingly strong desire to protect their privacy, while quantum dot light-emitting display devices in related technologies struggle to protect the privacy of the displayed images. Summary of the Invention

[0004] This application aims to provide a backlight module and display device to solve the technical problem that quantum dot light-emitting display devices are difficult to protect the privacy of the displayed image in related technologies.

[0005] In a first aspect, embodiments of this application propose a backlight module, including a back plate, the back plate including a plurality of grooves formed by indentation from a planar portion, and light-emitting units that can be raised and lowered along the depth direction of the grooves are disposed in the grooves. In a first state, the light-emitting units are lower than or flush with the planar portion; in a second state, the light-emitting units are higher than the planar portion.

[0006] In one possible implementation, the backplate further includes a plurality of flexible covers that fit over the groove, with the light-emitting unit disposed on the side of the flexible cover opposite to the groove.

[0007] The backplate also includes liquid injection pipes located below multiple grooves. The liquid injection pipes are connected to multiple grooves and are filled with coolant. The raising and lowering of the light-emitting unit is controlled by adjusting the liquid level of the coolant entering the grooves.

[0008] In one possible implementation, a drive motor is also included, the output shaft of which is located at one end of the injection pipe, and the inner wall of the injection pipe is provided with threads.

[0009] When the drive motor rotates in the first direction, the drive coolant is injected into the groove along the thread, and the light-emitting unit rises; when the drive motor rotates in the second direction, the drive coolant in the groove flows out of the groove, and the light-emitting unit descends.

[0010] In one possible implementation, a bearing is also included, with the inner ring of the bearing engaging with the output shaft of the drive motor and the outer ring of the bearing engaging with the inner wall of the injection pipe.

[0011] In one possible implementation, the sidewall of the groove is provided with a track, the flexible cover is sealed to the track, and can slide along the track.

[0012] In one possible implementation, a stop is provided at one end of the track near the flat portion to prevent the flexible cover from detaching from the track.

[0013] In one possible implementation, the light-emitting unit includes a blue light chip and a quantum dot unit, which are connected via an optical fiber coupler to mix into white light.

[0014] In one possible implementation, the quantum dot unit includes a quantum dot and an optical fiber encapsulation layer covering the quantum dot.

[0015] In one possible implementation, the planar portion of the backplate and the surface of the groove are further provided with silver nanowires, which are electrically connected to the light-emitting unit.

[0016] Secondly, embodiments of this application provide a liquid crystal display panel; and a backlight module as mentioned in the first aspect, disposed on the backlight side of the liquid crystal display panel, for providing a light source to the liquid crystal display panel.

[0017] This application provides a backlight module and display device. The backlight module includes a back plate with multiple recesses formed by indentation from a flat surface. Light-emitting units that are vertically movable along the depth of the recesses are disposed within the recesses. In a first state, the light-emitting units are lower than or flush with the flat surface; in a second state, the light-emitting units are higher than the flat surface. This application adjusts the state of the backlight module to change the relative position of the light-emitting units and the flat surface. When the light-emitting units are lower than or flush with the flat surface, some of the light emitted by the units is blocked by the sidewalls of the recesses, resulting in a narrow viewing angle display and privacy protection for the displayed image. When the light-emitting units are higher than the flat surface, the light emitted is not blocked, resulting in a wide viewing angle display where all light is utilized and the image brightness is high. This application can switch between narrow and wide viewing angle displays by changing the height of the light-emitting units, allowing users to switch from a normal display mode to a privacy protection mode for privacy protection of the displayed image. Attached Figure Description

[0018] The features, advantages, and technical effects of exemplary embodiments of the present application will now be described with reference to the accompanying drawings. In the drawings, the same components are referred to by the same reference numerals. The drawings are not drawn to scale and are only used to illustrate relative positions. The layer thicknesses in some areas are exaggerated for ease of understanding; the layer thicknesses in the drawings do not represent actual layer thickness proportions.

[0019] Figure 1 This diagram shows a structural schematic of the backlight module in a first state according to the first embodiment of this application;

[0020] Figure 2This diagram illustrates the structure of the backlight module in its second state according to the first embodiment of this application.

[0021] Figure 3 This invention provides a schematic diagram of the structure of a drive motor according to the first embodiment of the present application.

[0022] Figure 4 This shows a schematic diagram of the structure of the light-emitting unit provided in the first embodiment of this application;

[0023] Figure 5 This invention provides a schematic diagram of the structure of a display device according to a second embodiment of the present application.

[0024] Figure label:

[0025] 100. Backlight module;

[0026] 10. Back panel;

[0027] 11. Planar part;

[0028] 12. Groove;

[0029] 13. Light-emitting unit; 131. Blue light chip; 132. Quantum dot unit; 1321. Red quantum dot; 1322. Green quantum dot; 1323. Fiber optic encapsulation layer; 133. Fiber optic coupler;

[0030] 14. Flexible cover;

[0031] 15. Injection pipe; 151. Coolant;

[0032] 20. Drive motor; 21. Output shaft;

[0033] 200. LCD display panel;

[0034] 300. Display device. Detailed Implementation

[0035] The features and exemplary embodiments of various aspects of this application will now be described in detail. Numerous specific details are set forth in the following detailed description to provide a comprehensive understanding of this application. However, it will be apparent to those skilled in the art that this application can be implemented without some of these specific details. The following description of embodiments is merely intended to provide a better understanding of this application by illustrating examples. In the accompanying drawings and the following description, at least some well-known structures and techniques are not shown to avoid unnecessarily obscuring the application; and, for clarity, the dimensions of the regional structures may be exaggerated. Furthermore, the features, structures, or characteristics described below can be combined in any suitable manner in one or more embodiments.

[0036] In quantum dot light-emitting display devices, quantum dots emit fluorescence when excited by light to display images. These devices utilize nanoscale quantum dots for light emission, giving them advantages such as small size and simple manufacturing process.

[0037] However, as users become more aware of privacy protection, contemporary people have an increasingly strong desire to protect their privacy, while quantum dot light-emitting display devices in related technologies struggle to protect the privacy of the displayed images.

[0038] In view of this, embodiments of this application provide a backlight module and display device that achieves switching between narrow and wide viewing angles by changing the height of the light-emitting chip, thereby achieving screen privacy protection.

[0039] The specific structures of the backlight module and display device provided in the various embodiments of this application are described below with reference to the accompanying drawings.

[0040] First Embodiment

[0041] The first embodiment of this application provides a backlight module 100, including a back plate 10. The back plate 10 includes a plurality of grooves 12 formed by the inward recess of a planar portion 11. Light-emitting units 13 that can be raised and lowered along the depth direction of the grooves 12 are disposed in the grooves 12. In a first state, the light-emitting units 13 are lower than or flush with the planar portion 11; in a second state, the light-emitting units 13 are higher than the planar portion 11.

[0042] Figure 1 This is a schematic diagram of the structure of the backlight module 100 in a first state according to the first embodiment of this application; Figure 2 This is a schematic diagram of the structure of the backlight module 100 in the second state provided in the first embodiment of this application.

[0043] like Figure 1 As shown, the light-emitting unit 13 is lower than the flat portion 11, and some of the light emitted by the light-emitting unit 13 is blocked by the side wall of the recess 12. At this time, the brightness of the image displayed by the display device 300 is low, which is a narrow viewing angle display mode. If the user is located to the side of the display screen, that is, not directly above the screen, it is difficult to see the image displayed by the display device 300, thus protecting the privacy of the image.

[0044] like Figure 2 As shown, the light-emitting unit 13 is higher than the flat part 11, and all the light emitted by the light-emitting unit 13 is utilized. At this time, the brightness of the screen displayed by the display device 300 is high, which is a wide viewing angle display mode. Users can see the screen clearly from any position on the display screen.

[0045] Figure 1 and Figure 2Only two positions of the light-emitting unit 13 in the groove 12 are shown. In this application, the light-emitting unit 13 can be located at any position in the groove 12. That is, when the light-emitting unit 13 is lower than the plane part 11, the distance between the light-emitting unit 13 and the plane part 11 can be adjusted according to the user's needs. The user can adjust the light-emitting unit 13 to any height according to the degree of anti-peeping.

[0046] In this embodiment, by providing a groove 12 on the back plate 10, the light-emitting unit 13 can be raised and lowered in the depth direction of the groove 12 to change the height of the light-emitting unit 13, thereby switching between wide-viewing-angle display and narrow-viewing-angle display of the backlight module 100. Users can change the state of the backlight module 100 as needed to switch between normal display mode and privacy display mode.

[0047] In some embodiments, the back plate 10 further includes a plurality of flexible covers 14, which cover the groove 12, and the light-emitting unit 13 is disposed on the side of the flexible cover 14 away from the groove 12.

[0048] The back plate 10 also includes a liquid injection pipe 15 located below multiple grooves 12. The liquid injection pipe 15 is connected to multiple grooves 12. Coolant 151 is provided in the liquid injection pipe 15. The raising and lowering of the light-emitting unit 13 is controlled by adjusting the liquid level of the coolant 151 entering the groove 12.

[0049] Specifically, as more coolant 151 enters the groove 12 through the injection pipe 15, the coolant 151 pushes the flexible cover 14 upward, bringing the light-emitting unit 13 on the cover closer to the flat surface 11, gradually widening the viewing angle, utilizing more light, and increasing the brightness of the display panel. When the coolant 151 flows out of the groove 12 from the injection pipe 15, the coolant content in the groove 12 decreases, the height of the flexible cover 14 decreases accordingly, the distance between the light-emitting unit 13 on the cover and the flat surface 11 becomes farther, the viewing angle gradually narrows, more light is blocked, and the brightness of the display panel gradually decreases, thus protecting user privacy.

[0050] Because the cover material is flexible, its lifting and lowering process within the groove 12 ensures a tight connection with the side wall of the groove 12, creating a sealed space. This prevents the cooling liquid within the groove 12 from flowing out and contaminating the light-emitting unit 13. Furthermore, the groove 12 contains coolant 151, ensuring that the side of the flexible cover 14 without the light-emitting unit 13 contacts the coolant 151. This effectively cools the flexible cover 14, preventing the heat emitted by the light-emitting unit 13 from affecting the display effect.

[0051] The flat portion 11 of the backplate 10 can be made of metal, such as aluminum plate, aluminum alloy plate, or galvanized steel, and manufactured using processes such as stamping. Metal materials have good ductility, which can protect the backlight module 100 from breakage under external impact. The backplate 10 can also be made of plastic, such as polyimide, polycarbonate, polyethersulfone, polyethylene terephthalate, or polyethylene, to reduce the weight and cost of the backlight module 100.

[0052] In some embodiments, the system further includes a drive motor 20, the output shaft 21 of which is located at one end of the injection pipe 15, and the inner wall of the injection pipe 15 is provided with threads.

[0053] When the drive motor 20 rotates in the first direction, the drive coolant 151 is injected into the groove 12 along the thread, and the light-emitting unit 13 rises; when the drive motor 20 rotates in the second direction, the drive coolant 151 in the groove 12 flows out of the groove 12, and the light-emitting unit 13 descends.

[0054] The first direction is opposite to the second direction, and the first direction can be either clockwise or counterclockwise. Figure 3 This document shows a schematic diagram of the drive motor 20 provided in the first embodiment of this application; as shown... Figure 3 As shown, when the drive motor 20 rotates in the first direction, it drives the output shaft 21 of the drive motor 20 to rotate according to the rotation direction of the drive motor 20. The coolant 151 in the injection pipe 15 flows into the groove 12 through the threads on the inner wall of the injection pipe 15. The level of the coolant 151 in the groove 12 rises, pushing the flexible cover 14 to rise, thereby causing the light-emitting unit 13 to move upward.

[0055] When the drive motor 20 rotates in the second direction, it drives the output shaft 21 of the drive motor 20 to rotate according to the rotation direction of the drive motor 20. The coolant 151 in the injection pipe 15 flows outward from the groove 12 due to the threads on the inner wall of the injection pipe 15. The level of the coolant 151 in the groove 12 drops, causing the flexible cover 14 to drop, which in turn causes the light-emitting unit 13 to move downward.

[0056] In some embodiments, a snap fastener is provided on the side wall of the groove 12 to fix the position of the flexible cover 14. Specifically, when the user needs to adjust the display mode to a narrow viewing angle, the drive motor 20 can be stopped, allowing the flexible cover 14 to descend under its own weight. The descending flexible cover 14 compresses the coolant 151 within the groove 12, causing it to flow out of the groove 12. The surface of the coolant 151 remains in contact with the side of the flexible cover 14 without the light-emitting unit 13, thus cooling the light-emitting unit 13. When the backlight module 100 is adjusted to the user's desired viewing angle, i.e., when the flexible cover 14 descends to the desired position, the flexible cover 14 engages with the snap fastener on the groove 12, fixing its position.

[0057] In some embodiments, a bearing is also included, with the inner ring of the bearing engaging with the output shaft 21 of the drive motor 20 and the outer ring engaging with the inner wall of the injection pipe 15. By providing a bearing, the friction between the output shaft 21 of the drive motor 20 and the injection pipe 15 is reduced, thereby extending the service life.

[0058] In some embodiments, a track (not shown) is provided on the sidewall of the groove 12, and the flexible cover 14 is sealed to the track and can slide along the track. Providing a track on the sidewall of the groove 12 reduces the resistance when the flexible cover 14 moves up and down within the groove 12, preventing the flexible cover 14 from getting stuck when the user switches display modes to adjust the viewing angle, and extending the service life of the flexible cover 14. It is worth emphasizing that the sealed connection between the flexible cover 14 and the track ensures that the coolant 151 inside the groove 12 will not leak out.

[0059] In some embodiments, a stop (not shown) is provided at one end of the track near the flat portion 11 to restrict the flexible cover 14 from detaching from the track. By providing the stop, the light-emitting unit 13 is prevented from being higher than the flat portion 11 when the coolant 151 fills the groove 12, i.e. when the backlight module 100 is in the second state, thus preventing the flexible cover 14 from detaching from the track and improving the stability of the backlight module 100.

[0060] In some embodiments, the light-emitting unit 13 includes a blue light chip 131 and a quantum dot unit 132, which are connected by an optical fiber coupler 133 to mix into white light.

[0061] Figure 4 This is a schematic diagram of the structure of the light-emitting unit 13 provided in the first embodiment of this application.

[0062] Quantum dots are core-shell structures made of semiconductor materials, consisting of a central core and an outer shell. The materials used for quantum dots include one or more of the following: magnesium sulfide (MgS), cadmium telluride (CdTe), cadmium selenide (CdSe), cadmium sulfide (CdS), cadmium-doped zinc sulfide (CdZnS), zinc selenide (ZnSe), zinc telluride (ZnTe), zinc sulfide (ZnS), zinc oxide (ZnO), gallium arsenide (GaAs), gallium nitride (GaN), gallium phosphide (GaP), indium phosphide (InP), indium arsenide (InAs), indium nitride (InN), indium antimonide (InSb), aluminum phosphide (AlP), and aluminum antimonide (AlSb). For example, the central core might be a cadmium selenide (CdSe) core, and the outer shell a zinc sulfide (ZnS) shell. The particle size of quantum dots is generally around 10 nanometers. Due to the different sizes of quantum dots, the emitted light wavelength varies with the particle size and composition.

[0063] Furthermore, as a photoluminescent material, quantum dots can convert absorbed short-wavelength light into longer-wavelength light. To obtain a predetermined color, the quantum dots in the quantum layer can include one or more types. For example, in this embodiment of the invention, to obtain white light, the quantum dots in quantum dot unit 132 can include red quantum dots 1321 and green quantum dots 1322. The green quantum dots 1322 have a smaller particle size, while the red quantum dots 1321 have a larger particle size. Red quantum dots 1321 emit red light when excited by light, and green quantum dots 1322 emit green light when excited by light. At the same time, blue light is used as the excitation source, such as a blue LED chip used in this application. The blue light emitted by the blue light source excites quantum dot unit 132 and is converted into red and green light. The red, green, and blue light are mixed to obtain white light.

[0064] Of course, the quantum dots in this invention are not limited to quantum dots that emit red or green light, but also include quantum dots that emit any wavelength within the visible light wavelength range. Specifically, they can be set according to the quantum dot unit 132 of the desired color.

[0065] In related technologies, a light board is set on the back panel 10 to set a blue backlight, and a quantum dot film is set on the blue backlight. In this application, the blue light chip 131 and the quantum dot unit 132 are combined into a light-emitting unit 13 and directly set on the back panel 10. Compared with related technologies, the light board and quantum dot film are omitted, simplifying the structure of the backlight module 100, reducing the weight of the backlight module 100, and reducing the thickness of the light module.

[0066] In some embodiments, the quantum dot unit 132 includes quantum dots and an optical fiber encapsulation layer 1323 covering the quantum dots. By encapsulating the quantum dots with the optical fiber encapsulation layer, compared to the prior art where the quantum dot film is directly placed above the backlight source, exposing the quantum dots to the air, this application avoids the quantum dots coming into contact with water and oxygen in the air, thus preventing the luminous performance of the quantum dots from being affected by moisture and oxygen in the air and ensuring display quality.

[0067] In some embodiments, the surfaces of the planar portion 11 and the groove 12 of the back plate 10 are further provided with silver nanowires (not shown in the figure), which are electrically connected to the light-emitting units 13. By providing silver nanowires, electrical connections are achieved between the light-emitting units 13.

[0068] In this embodiment, a groove 12 is provided on the back plate 10, allowing the light-emitting unit 13 to move up and down in the depth direction of the groove 12, thereby changing the height of the light-emitting unit 13 and switching between wide-viewing-angle and narrow-viewing-angle displays of the backlight module 100. Users can change the state of the backlight module 100 according to their needs, switching between normal display mode and privacy display mode. Coolant 151 is provided in the groove 12 to cool the light-emitting unit 13; a track is provided on the side wall of the groove 12 to reduce the resistance when the flexible cover 14 moves up and down; a stop is provided at one end of the track near the plane 11 to prevent the flexible cover 14 from sliding out of the track, increasing the stability of the backlight module 100; by coupling the blue light chip 131 with the quantum dot unit 132 to form the light-emitting unit 13, the lamp board and quantum dot film are omitted, reducing the weight of the backlight module 100; at the same time, the quantum dots are encapsulated by the light encapsulation layer to prevent the quantum dots from contacting external water vapor and oxygen, improving the stability of the quantum dot display.

[0069] Second Embodiment

[0070] Figure 5 This is a schematic diagram of the structure of the display device 300 provided in the second embodiment of this application.

[0071] like Figure 5 As shown, the second embodiment of this application provides a display device 300, including:

[0072] The liquid crystal display panel 200 and the backlight module 100 mentioned in the first embodiment are disposed on the backlight side of the liquid crystal display panel 200 and are used to provide a light source to the liquid crystal display panel 200.

[0073] It should be readily understood that the terms “on,” “above,” and “on top of” in this application should be interpreted in the broadest possible sense, such that “on” means not only “directly on something” but also “on something” with an intermediate feature or layer therebetween, and that “above” or “on top of” means not only “on top of something” but also “on top of something” without an intermediate feature or layer therebetween (i.e., directly on something).

[0074] The term "layer" as used herein can refer to a portion of material comprising a region of thickness. A layer may extend over the entire underlying or overlying structure, or may have a extent smaller than that of the underlying or overlying structure. Furthermore, a layer may be a region of a homogeneous or non-homogeneous continuous structure, with a thickness less than that of the continuous structure. For example, a layer may be located between the top and bottom surfaces of a continuous structure, or between any pairs of lateral planes at the top and bottom surfaces. A layer may extend laterally, vertically, and / or along a tapered surface. A substrate may be a layer, and may include one or more layers, and / or may have one or more layers located on, above, and / or below it. A layer may include multiple layers. For example, an interconnect layer may include one or more conductor and contact layers (forming contacts, interconnects, and / or vias therein) and one or more dielectric layers.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A backlight module, comprising a backplate, characterized in that, The back plate includes a plurality of grooves formed by the inward recess of the planar portion. A light-emitting unit that can be raised and lowered along the depth direction of the groove is disposed in the groove. In a first state, the light-emitting unit is lower than or flush with the planar portion; in a second state, the light-emitting unit is higher than the planar portion. The back plate also includes a plurality of flexible covers, which cover the groove, and the light-emitting unit is disposed on the side of the flexible cover opposite to the groove; The back plate also includes a liquid injection pipe located below the plurality of grooves. The liquid injection pipe is connected to the plurality of grooves and is filled with coolant. The raising and lowering of the light-emitting unit is controlled by adjusting the liquid level of the coolant entering the groove.

2. The backlight module according to claim 1, characterized in that, It also includes a drive motor, the output shaft of which is located at one end of the injection pipe, and the inner wall of the injection pipe is provided with threads; When the drive motor rotates in the first direction, it drives the coolant to be injected into the groove along the thread, and the light-emitting unit rises; when the drive motor rotates in the second direction, it drives the coolant in the groove to flow out of the groove, and the light-emitting unit descends.

3. The backlight module according to claim 2, characterized in that, It also includes a bearing, the inner ring of which mates with the output shaft of the drive motor, and the outer ring of which mates with the inner wall of the injection pipe.

4. The backlight module according to claim 1, characterized in that, The sidewall of the groove is provided with a track, the flexible cover is sealed to the track, and can slide along the track.

5. The backlight module according to claim 4, characterized in that, A stop is provided at one end of the track near the flat portion to prevent the flexible cover from detaching from the track.

6. The backlight module according to claim 1, characterized in that, The light-emitting unit includes a blue light chip and a quantum dot unit, which are connected by an optical fiber coupler to mix into white light.

7. The backlight module according to claim 6, characterized in that, The quantum dot unit includes a quantum dot and an optical fiber encapsulation layer covering the quantum dot.

8. The backlight module according to claim 1, characterized in that, The surface of the planar portion and the groove of the back plate is further provided with silver nanowires, which are electrically connected to the light-emitting unit.

9. A display device, characterized in that, include: LCD display panel; and The backlight module as described in any one of claims 1 to 8 is disposed on the backlight side of the liquid crystal display panel and is used to provide a light source to the liquid crystal display panel.

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