CN113655658A

CN113655658A - Backlight source, manufacturing method thereof, display device and electronic equipment

Info

Publication number: CN113655658A
Application number: CN202110854562.2A
Authority: CN
Inventors: 秦伟华; 陈国辉
Original assignee: Honor Device Co Ltd
Current assignee: Honor Device Co Ltd
Priority date: 2021-07-27
Filing date: 2021-07-27
Publication date: 2021-11-16
Also published as: WO2023005322A1

Abstract

The application discloses a backlight source, a manufacturing method thereof, a display device and electronic equipment, relates to the technical field of display, and aims to solve the problem that the heat dissipation of the backlight source in the related art increases the power consumption of the display device. The backlight source comprises a substrate, a plurality of light-emitting elements and a thermoluminescent material layer, wherein the light-emitting elements are arranged on one side of the substrate, and at least a part of the light-emitting elements can emit light with a wavelength of lambda₁The primary color light of (1); the thermoluminescent material layer covers one side of the substrate, where the plurality of light-emitting elements are arranged, and is in heat conduction connection with the light-emitting elements, and is configured to emit light with a wavelength lambda when being heated₂Of said primary color light, λ₁And λ₂Satisfies the following conditions: lambda₂‑λ₀|<|λ₁‑λ₀L, where λ₀The wavelength values corresponding to the points of the spectral trajectory lines of the primary colors at the corners of the chromaticity diagram are shown in the chromaticity diagram. The method and the device can be used for electronic equipment such as mobile phones.

Description

Backlight source, manufacturing method thereof, display device and electronic equipment

Technical Field

The present disclosure relates to the field of display technologies, and in particular, to a backlight, a manufacturing method thereof, a display device, and an electronic apparatus.

Background

In the liquid crystal display device, since the display panel itself cannot emit light, a backlight mounted on the back side of the display panel is required to supply light to display an image. Since the LED (Light Emitting Diode) backlight has the advantages of excellent color gamut display and good mechanical vibration stability, the use of the LED backlight is one of the mainstream trends in the development of liquid crystal display devices.

However, when a plurality of LEDs are used simultaneously, the heat generation phenomenon is significant, and especially, the heat dissipation problem of the LEDs in the Mini LED (also called sub-millimeter light emitting diode, LED die size is about 50-200 μm) backlight is more prominent.

In the related art, most of the heat generation processing ideas and measures for the LED backlight are heat dissipation, and an additional heat dissipation device (such as a heat dissipation fan) is designed to achieve the purpose of heat dissipation, however, this increases the power consumption of the display device, which is not favorable for energy saving.

Disclosure of Invention

Embodiments of the present application provide a backlight source, a manufacturing method thereof, a display device, and an electronic apparatus, which are used to solve the problem that the heat dissipation of the backlight source in the related art increases the power consumption of the display device.

In order to achieve the above purpose, the embodiment of the present application adopts the following technical solutions:

in a first aspect, an embodiment of the present disclosure provides a backlight including a substrate, a plurality of light emitting elements disposed on one side of the substrate, and a thermoluminescent material layer, wherein at least a portion of the light emitting elements can emit light with a wavelength λ₁The primary color light of (1); the thermoluminescent material layer covers one side of the substrate, where the plurality of light-emitting elements are arranged, and is in heat conduction connection with the light-emitting elements, and is configured to emit light with a wavelength lambda when being heated₂Of said primary color light, λ₁And λ₂Satisfies the following conditions: lambda₂-λ₀|<|λ₁-λ₀L, where λ₀The wavelength values corresponding to the points of the spectral trajectory lines of the primary colors at the corners of the chromaticity diagram are shown in the chromaticity diagram.

By adopting the scheme, the light-emitting element can be radiated, so that the display device does not need to be provided with an additional radiating device for radiating, and the power consumption of the display device is reduced; but also is beneficial to improving the backlight sourceThe light emission intensity of (1). At the same time, since | λ₂-λ₀|<|λ₁-λ₀I, such that the wavelength λ of the primary color light emitted by heating the thermoluminescent material layer₂Wavelength lambda of primary color light emitted from the light emitting element₁Closer to λ₀Therefore, the wavelength range of the primary color light emitted by the backlight source is widened, and the area of the chromaticity triangle of the display device is increased, so that the color gamut of the display device is improved, and the display effect of the display device is improved.

In some embodiments, the primary color light is blue light, and λ₀≤λ₂<λ₁。

By adopting the scheme, the green light and the red light which are relatively pure can be simultaneously excited after the blue light passes through the quantum dot film, and the green light and the red light can be mixed with the blue light emitted by the backlight source to form white light with higher quality, so that the color gamut size of the display device can be improved.

In some embodiments, each of the light emitting elements is a blue light emitting element.

By adopting the scheme, the backlight source is a pure blue light source, so that more pure green light and red light can be excited after high-energy blue light emitted by the backlight source passes through the quantum dot film, and the color gamut of the display device is further improved.

In some embodiments, the material of the thermoluminescent material layer includes a resin and a rare earth phosphor.

By adopting the scheme, the manufacturing cost of the backlight source is favorably reduced, and meanwhile, the wavelength of the light excited by heating of the thermoluminescent material layer can be accurately controlled by changing the proportion of the rare earth fluorescent powder, so that the relationship between the wavelength of the light excited by heating of the thermoluminescent material layer and the wavelength of the light emitted by the light-emitting element can be better met.

In some embodiments, the resin is a transparent resin.

By adopting the scheme, the light emitted by the rare earth fluorescent powder positioned in the thermoluminescent material layer can be conveniently emitted, so that the light emitting efficiency of the thermoluminescent material layer is ensured.

In some embodiments, the primary color light is blue light and the rare earth phosphor is europium activated barium magnesium aluminate.

By adopting the scheme, the thermoluminescent material layer can have higher luminous efficiency and color rendering property. Meanwhile, the rare earth fluorescent powder also has the advantages of very stable physical and chemical properties, relatively fixed production process, easy synthesis and the like.

In some embodiments, the material of the thermoluminescent material layer further comprises at least one of an ultraviolet light absorber, a diluent, and a temperature regulator.

By adopting the scheme, the ultraviolet absorbent can reduce the harm of the light emitted by the thermoluminescent material layer to human bodies; the thinner can ensure that the components in the thermoluminescent material are mixed more uniformly; the temperature regulator may avoid damage to the thermoluminescent material layer due to an excessive temperature.

In some embodiments, the ultraviolet light absorber is one of UV-3035, UV-583, UV-329.

By adopting the scheme, the UV-3035 has better ultraviolet absorption performance and thermal stability; the UV-583 has the advantages of no toxicity, no flammability, no explosion, no corrosion, good stability and the like; the UV-329 has the advantages of non-flammability, non-explosion, non-toxicity, safe and harmless use and the like.

In some embodiments, the diluent is an organic solvent.

By adopting the scheme, the organic solvent can well mix the resin and the rare earth fluorescent powder with the organic solvent, so that the rare earth fluorescent powder is mixed more uniformly.

In some embodiments, the temperature modifier comprises metal particles.

By adopting the scheme, the metal particles can quickly absorb the heat of the thermoluminescent material layer, so that the overhigh temperature of the thermoluminescent material layer can be well avoided.

In some embodiments, the metal particles include at least one of iron particles, copper particles, and tungsten particles.

By adopting the scheme, the structure can be ensured not to be melted when the heat is absorbed quickly.

In some embodiments, the material of the thermoluminescent material layer is prepared from the following components: 30-150 parts of resin; 20-140 parts of rare earth fluorescent powder; 0.5 part of ultraviolet absorber; 10 parts of the diluent; 0.5 part of temperature regulator.

By adopting the scheme, the requirement on the luminous efficiency, luminous intensity and luminous uniformity of the thermoluminescent material layer is met, and meanwhile, the ultraviolet light emitted by the thermoluminescent material layer can be well absorbed, and the overhigh temperature of the thermoluminescent material layer is avoided.

In some embodiments, the thermoluminescent material layer comprises a first thermoluminescent material layer filling a space between two of the plurality of light emitting elements.

By adopting the scheme, not only can the sufficient heat dissipation of the plurality of light-emitting elements be ensured, but also the first thermoluminescent material layer can be ensured to be heated sufficiently to emit light; meanwhile, the first thermoluminescent material layer can be prevented from influencing the light emission of the light-emitting element.

In some embodiments, the thermoluminescent material layer further comprises a second thermoluminescent material layer located at the periphery of the array formed by the plurality of light emitting elements and in contact with the light emitting elements located at the edge of the array.

By adopting the scheme, the light-emitting element array can be better radiated, and the thermoluminescent material layer can be more fully heated and emit light, so that the luminous intensity of the backlight source can be further improved.

In some embodiments, the backlight source further includes a protective layer covering the light emitting element, and a surface of the protective layer on a side away from the substrate is flush with a surface of the thermoluminescent material layer on a side away from the substrate.

By adopting the above scheme, damages such as scratches of the light-emitting element can be avoided, steps between the protective layer and the thermoluminescent material layer can be avoided, and the optical microstructure can be conveniently and subsequently arranged on the protective layer and the thermoluminescent material layer.

In some embodiments, the backlight source includes a light exit surface on which a plurality of light condensing portions for condensing light are disposed.

By adopting the scheme, the light utilization rate of the backlight source is improved.

In some embodiments, the light-condensing portion has a triangular or arcuate shape in a cross section parallel to a thickness direction of the substrate.

By adopting the scheme, the light-gathering part can be conveniently manufactured.

In some embodiments, the height of the light-condensing portion is 10-20 μm.

By adopting the scheme, the light-gathering part can be manufactured through the roller, so that the light-gathering part is convenient to manufacture.

In some embodiments, the light emitting surface includes a side surface of the thermoluminescent material layer away from the substrate.

By adopting the scheme, the utilization rate of the light emitted by heating the thermoluminescent material layer can be improved.

In a second aspect, an embodiment of the present application provides a display device, including a liquid crystal display panel, the backlight source in the first aspect, and a quantum dot film disposed between the backlight source and the liquid crystal display panel.

The beneficial effects of the display device in the embodiment of the present application are the same as those of the backlight source in the first aspect, and are not described herein again.

In a third aspect, embodiments of the present application provide an electronic device, including the backlight described in the first aspect.

The beneficial effects of the electronic device in the embodiment of the application are the same as those of the backlight source in the first aspect, and are not described herein again.

In a fourth aspect, an embodiment of the present application provides a manufacturing method for the backlight source described in the first aspect, including the following steps: covering a thermoluminescent material layer on one side of the substrate where the plurality of light-emitting elements are arranged, and enabling the thermoluminescent material layer to be in heat conduction connection with the light-emitting elements.

The beneficial effects of the manufacturing method of the backlight source in the embodiment of the application are the same as those of the backlight source in the first aspect, and are not described herein again.

In some embodiments, covering the thermoluminescent material layer on the side of the substrate where the plurality of light emitting elements are disposed, such that the thermoluminescent material layer is in thermally conductive connection with the light emitting elements, comprises: filling a thermoluminescent material into a space between every two of the plurality of light-emitting elements to form a first thermoluminescent material layer; wherein the thermoluminescent material layer comprises the first thermoluminescent material layer.

In some embodiments, before filling the thermoluminescent material into the space between two of the plurality of light emitting elements to form the first thermoluminescent material layer, the thermoluminescent material layer further comprises: arranging a thermoluminescent material at the periphery of the array formed by the plurality of light-emitting elements and contacting the light-emitting elements at the edge of the array to form a second thermoluminescent material layer; wherein the thermoluminescent material layer comprises the second thermoluminescent material layer.

In some embodiments, the first layer of thermoluminescent material is fabricated by a screen printing process.

By adopting the scheme, the manufacturing process of the first thermoluminescent material layer is simpler, the steps are fewer, and the manufacturing efficiency of the backlight source is improved.

In some embodiments, the method of making a backlight further comprises the steps of: and arranging a light-transmitting material on one side surface of each light-emitting element far away from the substrate to form a protective layer.

By adopting the scheme, the damage such as scratch of the light-emitting element can be avoided.

In some embodiments, the protective layer is fabricated by a screen printing process.

By adopting the scheme, the manufacturing process of the protective layer is simpler, the steps are fewer, and the manufacturing efficiency of the backlight source is improved.

In some embodiments, the method of making a backlight further comprises the steps of: and a plurality of light condensing parts for condensing light are formed on the light emitting surface of the backlight.

In some embodiments, forming a plurality of light-condensing portions for condensing light on the light-emitting surface of the backlight includes: and forming a plurality of light-condensing parts on the surface of the thermoluminescent material layer far away from the substrate.

Drawings

FIG. 1 is a schematic diagram of a display device according to some embodiments of the present disclosure;

FIG. 2 is a schematic diagram of the operation of the display device of FIG. 1;

FIG. 3 is a chromaticity diagram in an embodiment of the present application;

FIG. 4 is a cross-sectional view of a backlight in some embodiments of the present application;

FIG. 5 is a top view of FIG. 4;

FIG. 6 is a cross-sectional view of a backlight in other embodiments of the present application;

FIG. 7 is a top view of FIG. 6;

FIG. 8 is a cross-sectional view of a backlight in other embodiments of the present application;

FIG. 9 is a schematic view of a light-gathering portion according to some embodiments of the present disclosure;

FIG. 10 is a schematic view of a light-collecting portion according to other embodiments of the present disclosure;

FIG. 11 is a schematic structural diagram of a display device according to further embodiments of the present application;

FIG. 12 is a schematic diagram of the operation of a display device according to further embodiments of the present application;

FIG. 13 is a schematic diagram of the backlight of FIG. 12;

FIG. 14 is a process diagram of one method of making the backlight shown in FIGS. 4 and 5;

FIG. 15 is a process diagram of another method of making the backlight shown in FIGS. 4 and 5;

FIG. 16 is a diagram of a process for forming a thermoluminescent material layer for the backlight sources of FIGS. 6 and 7;

fig. 17 is a flowchart of a process for manufacturing the thermoluminescent material layer of the backlight sources in fig. 6 and 7.

Detailed Description

In the embodiments of the present application, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

The electronic device in the embodiment of the present application may be a display device with a backlight source, such as a mobile phone, a tablet computer, a notebook computer, a computer display, a vehicle-mounted display, a television, a smart screen, an advertisement screen, and a wearable device (e.g., a smart watch).

Fig. 1 is a schematic structural diagram of a display device in some embodiments of the present application, as shown in fig. 1 and fig. 2, in which various components are not shown in actual scale of the product, and fig. 2 is an operational schematic diagram of the display device in fig. 1. The display device includes a case 100, a liquid crystal display panel 200, a backlight 300, a back plate 400, and a quantum dot film 500.

The lcd panel 200 is disposed on the housing 100, the back plate 400 is disposed in the housing 100 and located at the back side of the lcd panel 200, the back plate 400 has a placing cavity 410, the backlight 300 is disposed in the placing cavity 410, and the quantum dot film 500 is disposed between the backlight 300 and the lcd panel 200 and includes red quantum dots 510 and green quantum dots 520.

The backlight 300 is a direct type backlight, and includes a substrate 1, a plurality of light emitting elements 2, and a thermoluminescent material layer 3. The plurality of light emitting elements 2 are arranged on one side of the substrate 1, each light emitting element 2 is a blue light emitting element, the thermoluminescent material layer 3 covers one side of the substrate 1, on which the plurality of light emitting elements 2 are arranged, and is in heat conduction connection with the light emitting elements 2, and the thermoluminescent material layer 3 is configured to be heated to emit blue light.

As shown in fig. 1 and 2, the blue Light Emitting element 2 is a blue LED, but is not limited thereto, and the blue Light Emitting element 2 may also be a white LED coated with blue phosphor, and may also be a blue OLED (Organic Light-Emitting Diode) device.

The backlight 300 may be a common LED (LED crystal grain size is more than 200 μm), a Mini LED, or a Micro LED (LED crystal grain size is less than or equal to 50 μm), and is not limited herein.

As shown in fig. 2, when the display device is operated, the blue light emitted by the blue light emitting element 2 and the blue light emitted by the thermoluminescent material layer 3 are heated to pass through the quantum dot film 500, the red quantum dot 510 is excited to emit red light, the green light emitted by the green quantum dot 520 is excited, then the red light, the green light, the blue light emitted by the blue light emitting element 2 and the thermoluminescent material layer 3 are compounded to form white light, and the white light enters the liquid crystal display panel 200 to be used for displaying on the liquid crystal display panel 200.

In the display device, the thermoluminescent material layer 3 covers one side of the substrate 1 where the plurality of light-emitting elements 2 are arranged and is in heat conduction connection with the light-emitting elements 2, so that the thermoluminescent material layer 3 can absorb heat emitted by the light-emitting elements 2 to emit light, and not only can the light-emitting elements 2 be cooled, but also the display device does not need to be provided with an additional cooling device to cool, which is beneficial to reducing the power consumption of the display device, and in addition, the light emitted by the thermoluminescent material layer 3 and the light emitted by the light-emitting elements 2 are overlapped together, so that the luminous intensity of the backlight 300 is favorably improved, and the display effect of the display device is favorably improved. In addition, since each light emitting element 2 is a blue light emitting element, the backlight 300 is a pure blue light source, so that more pure green light and red light can be excited by the high-energy blue light emitted by the backlight 300 after passing through the quantum dot film 500, and the green light and the red light can be mixed with the blue light emitted by the backlight 300 to form white light with higher quality, thereby further improving the color gamut of the display device.

In some embodiments, as shown in fig. 1, 2 and 3, fig. 3 is a chromaticity diagram in an embodiment of the present application. Each light-emitting element 2 can emit light with a wavelength λ₁The thermoluminescent material layer 3 is configured to emit light having a wavelength λ when heated₂Blue light of (a)₁And λ₂Satisfies the following conditions: lambda [ alpha ]₀≤λ₂<λ₁，λ₀Is the wavelength value, lambda, corresponding to the point A of the blue light spectrum trace AB at the corner of the chromaticity diagram₀Approximately 450 nm. That is: wavelength lambda of blue light emitted by heating the thermoluminescent material layer 3₂Light emission wavelength lambda of blue light emitting element₁Closer to λ₀For example, when the blue light emitting element is a blue LED, λ₂Has a wavelength of 463nm to 475nm, and has a wavelength of 455nm of blue light emitted by the thermal excitation of the thermoluminescent material layer 3.

In this embodiment, the wavelength λ of blue light emitted due to the thermal heating of the thermoluminescent material layer 3 is configured₂Less than the wavelength lambda of blue light emitted by each light-emitting element 2₁That is, in the chromaticity diagram, a point corresponding to the wavelength of the blue light emitted by the thermoluminescent material layer 3 is closer to a point a located at a corner of the chromaticity diagram, so that the wavelength range of the blue light emitted by the backlight 300 is widened by the thermoluminescent material layer 3, the area of the chromaticity triangle of the display device is increased, the color gamut of the display device is increased, and the display effect of the display device is further improved.

It should be noted that: color gamut refers to the range of colors (wavelengths) of light, and colorimetry studies describe the range of colors visible to the human eye using the chromaticity diagram, which was published by the international commission on illumination (CIE) in 1931 in fig. 3. The visible light wave band from 400nm to 700nm, i.e. the visible spectrum color of human eyes, connects the spectrum color points in XY coordinate system (called spectrum locus) to form a chromaticity diagram (also called horseshoe diagram), and the light corresponding to the spectrum locus is monochromatic light. In the chromaticity diagram of fig. 3, line segment AB is the blue light spectrum trace, line segment CD is the green light spectrum trace, and line segment EF is the red light spectrum trace. The triangle formed by respectively taking one point from the blue light spectrum trajectory line, the green light spectrum trajectory line and the red light spectrum trajectory line is a chromaticity triangle, the larger the area of the chromaticity triangle is, the more colors can be synthesized by the chromaticity triangle, and the larger the color gamut of the display device is. To maximize the area of the chromaticity triangle of the display device, it is preferable to design the chromaticity diagram as an inscribed maximum triangle in principle, i.e., the point corresponding to the blue wavelength should be close to the lower left corner on the chromaticity diagram, the point corresponding to the red wavelength should be close to the lower right corner on the chromaticity diagram, and the point corresponding to the green wavelength should be close to the upper left corner on the chromaticity diagram.

In the backlight 300, besides only the thermoluminescent material layer 3 emitting blue light, the thermoluminescent material layer 3 emitting blue light and other primary colors of light may also be disposed on the substrate 1, for example, two thermoluminescent material layers 3 emitting blue light and red light are disposed on the substrate 1 at the same time, so that the two thermoluminescent material layers 3 can be heated to emit blue light and red light, and thus the blue light and the red light can be combined with the blue light emitted by the light emitting element 2 through the quantum dot film 500 to form white light for the display of the liquid crystal display panel 200.

The thermally conductive connection between the thermoluminescent material layer 3 and the light emitting element 2 is not exclusive, and in some embodiments, as shown in fig. 4 and 5, fig. 4 is a cross-sectional view of a backlight 300 in some embodiments of the present application, and fig. 5 is a top view of fig. 4. The thermoluminescent material layer 3 includes a first thermoluminescent material layer 31, and the first thermoluminescent material layer 31 fills the space between two of the plurality of light emitting elements 2. By arranging the first thermoluminescent material layer 31 in this way, the first thermoluminescent material layer can be fully contacted with the plurality of light-emitting elements 2 to fully absorb heat of the plurality of light-emitting elements 2, so that not only is sufficient heat dissipation of the plurality of light-emitting elements 2 ensured, but also sufficient heating and luminescence of the first thermoluminescent material layer 31 can be ensured, and further improvement of the luminous intensity of the backlight 300 is facilitated. Meanwhile, since the first thermoluminescent material layer 31 is filled in the space between two adjacent light emitting elements 2, the first thermoluminescent material layer 31 can be prevented from covering the surface of one side of the light emitting element 2 away from the substrate 1, so that the first thermoluminescent material layer 31 can be prevented from influencing the light emitting of the light emitting element 2.

In some embodiments, as shown in fig. 6 and 7, fig. 6 is a cross-sectional view of a backlight 300 in other embodiments of the present disclosure, and fig. 7 is a top view of fig. 6. In addition to the embodiments shown in fig. 4 and 5, the thermoluminescent material layer 3 further comprises a second thermoluminescent material layer 32, and the second thermoluminescent material layer 32 is located at the periphery of the array formed by the plurality of light emitting elements 2 and is in contact with the light emitting elements 2 located at the edge of the array of light emitting elements 2. By such arrangement, the thermoluminescent material layer 3 can be ensured to be in full contact with the light-emitting element 2 positioned at the center of the light-emitting element 2 array, and the thermoluminescent material layer 3 can be ensured to be in full contact with the light-emitting element 2 positioned at the edge of the light-emitting element 2 array, so that the light-emitting element 2 array can be better cooled, and the thermoluminescent material layer 3 can be more fully heated to emit light, thereby being beneficial to further improving the luminous intensity of the backlight 300.

As shown in fig. 7, the second thermoluminescent material layer 32 may be in contact with the edge of the first thermoluminescent material layer 31, but is not limited thereto, and a gap may be formed between the second thermoluminescent material layer 32 and the edge of the first thermoluminescent material layer 31.

In some embodiments, as shown in fig. 6, the backlight 300 further includes a protection layer 4 covering the light emitting elements 2, and a surface of the protection layer 4 away from the substrate 1 is flush with a surface of the thermoluminescent material layer 3 away from the substrate 1.

By providing the protective layer 4, the protective layer 4 can protect the light emitting element 2, and damage such as scratch to the light emitting element 2 can be avoided. Because the surface of one side of the protective layer 4 away from the substrate 1 is flush with the surface of one side of the thermoluminescent material layer 3 away from the substrate 1, a step between the protective layer 4 and the thermoluminescent material layer 3 can be avoided, and thus, the optical microstructures for adjusting the light emitting direction can be conveniently arranged on the protective layer 4 and the thermoluminescent material layer 3.

As shown in fig. 6, a surface of the protection layer 4 away from the substrate 1 may be flush with surfaces of the first thermoluminescent material layer 31 and the second thermoluminescent material layer 32 away from the substrate 1, or may be flush with only a surface of the first thermoluminescent material layer 31 away from the substrate 1, which is not limited herein.

The protective layer 4 is made of a light-transmitting material, for example, the light-transmitting material may include transparent resin, and the light-transmitting material is prepared by, for example: 100 parts of resin (such as transparent resin); 0.5 part of ultraviolet absorber; and 1 part of diluent. The ultraviolet light absorber is mainly used for absorbing ultraviolet light emitted by the light-emitting element 2, and the diluent is mainly used for reducing the viscosity of the light-transmitting material, so that the components of the light-transmitting material are mixed more uniformly.

In some embodiments, as shown in FIG. 8, FIG. 8 is a cross-sectional view of a backlight 300 according to other embodiments of the present disclosure. The thermoluminescent material layer 3 covers the plurality of light emitting elements 2. By such an arrangement, the thermoluminescent material layer 3 can be ensured to be in full contact with the plurality of light-emitting elements 2, so that not only can the array of light-emitting elements 2 be better cooled, but also the light-emitting intensity of the backlight 300 can be further improved.

In some embodiments, as shown in fig. 9 and 10, fig. 9 is a schematic structural diagram of the light-gathering portion 51 in some embodiments of the present application, fig. 10 is a schematic structural diagram of the light-gathering portion 51 in other embodiments of the present application, and neither of fig. 9 and 10 is shown according to actual product scale. The backlight 300 includes a light output surface 5, and a plurality of light collecting portions 51 for collecting light are provided on the light output surface 5. Since the light-condensing portion 51 has a light-condensing effect, light loss caused by scattering of light emitted from the light-emitting surface 5 can be reduced, thereby facilitating improvement of the light utilization rate of the backlight 300.

The shape of the light-condensing portion 51 is not exclusive, and in some embodiments, as shown in fig. 9, the light-condensing portion 51 has a triangular shape in a cross section parallel to the thickness direction of the substrate 1. For example, the cross section may be an equilateral triangle with a side length of 20 μm.

The divergent light rays emitted from the light emitting surface 5 are refracted by the light condensing portion 51 having a triangular cross section and then approach each other in a direction close to each other, so that the light rays can be prevented from diverging from the edge of the substrate 1, and more light rays can be ensured to irradiate the display panel.

The light-condensing portion 51 may be a triangular prism or a triangular pyramid, and is not particularly limited herein.

In some embodiments, as shown in fig. 10, the light condensing portion 51 has an arcuate shape in a cross section parallel to the thickness direction of the substrate 1. The divergent light rays emitted from the light emitting surface 5 are refracted by the light condensing portion 51 having an arcuate cross section and then approach each other in a direction close to each other, so that the light rays can be prevented from diverging from the edge of the substrate 1, and more light rays can be ensured to irradiate the display panel.

The arch may be a major arch or a minor arch, and is not particularly limited herein. The light converging portion 51 may be a rotating body formed by rotating the arcuate cross section, or may be a stretched body formed by stretching the arcuate cross section, and is not particularly limited herein.

In some embodiments, the height of the light-condensing portion 51 is 10 to 20 μm. In this size range, the light-condensing portion 51 belongs to an optical microstructure, so that the light-condensing portion 51 can be formed by rolling the light-condensing portion 51 on the light-emitting surface 5 of the backlight 300 by a roller, thereby facilitating the manufacturing of the light-condensing portion 51.

In some embodiments, as shown in fig. 9 and 10, the light emitting surface 5 includes a side surface of the thermoluminescent material layer 3 away from the substrate 1, that is, the light condensing portion 51 is formed on a side surface of the thermoluminescent material layer 3 away from the substrate 1, so that the light condensing portion 51 can condense the light emitted by the thermoluminescent material layer 3 when heated, so as to improve the utilization rate of the light emitted by the thermoluminescent material layer 3 when heated.

Of course, as shown in fig. 9, the light-condensing portion 51 is disposed on the surface of the protection layer 4 away from the substrate 1, that is, the light-emitting surface 5 further includes a surface of the protection layer 4 away from the substrate 1, that is, the light emitted by the light-emitting element 2 and the thermoluminescent material layer 3 can be condensed, so as to improve the utilization rate of the light emitted by the light-emitting element 2 and the thermoluminescent material layer 3.

The backlight 300 may be a direct-type backlight, or a side-type backlight, specifically, as shown in fig. 11, fig. 11 is a schematic structural diagram of a display device in other embodiments of the present application, and each component in the diagram is not shown in actual scale of a product. The main differences between this display device and the display device shown in fig. 1 are: the display device further includes a light guide plate 600, the backlight 300 is located on one side of the light guide plate 600, light emitted from the backlight 300 forms a surface light source after passing through the light guide plate 600, and enters the liquid crystal display panel 200 after passing through the quantum dot film 500, so as to be used for displaying of the liquid crystal display panel 200. The specific configuration of the backlight 300 can be set with reference to the structures of the backlight 300 in fig. 5 to 10, and will not be described herein again.

As shown in fig. 12 and 13, fig. 12 is a schematic diagram of a display device according to another embodiment of the present disclosure, and fig. 13 is a schematic diagram of a structure of the backlight 300 in fig. 12. The main differences between the display device in this embodiment and the display devices shown in fig. 1 and 2 are that: a part of the light emitting elements 2 on the substrate 1 are blue light emitting elements (shown by reference numeral 2 a), another part of the light emitting elements 2 are green light emitting elements (shown by reference numeral 2 b), and the thermoluminescent material layer 3 is configured to emit green light when heated. The quantum dot film 500 includes red quantum dots 510.

Each green light-emitting element can emit light with wavelength of lambda₁Is arranged to emit light at a wavelength λ upon heating, the layer of thermoluminescent material 3₂Green light of (2), lambda₁And λ₂Satisfies the following conditions: lambda₂-λ₀|<|λ₁-λ₀|，λ₀Is the wavelength value, lambda, corresponding to the point G at the corner of the chromaticity diagram where the spectrum trace line CD of the green light is located₀About 520 nm; that is: wavelength lambda of green light emitted by heating the thermoluminescent material layer 3₂Light emission wavelength lambda of green light emitting element₁Closer to λ₀For example, when the green light emitting element is an LED, λ₂Is 530nm to 540nm, and the wavelength of green light emitted by the thermal excitation of the thermoluminescent material layer 3 is 525 nm.

When the display device works, blue light emitted by the blue light emitting element, green light emitted by the green light emitting element and green light emitted by the thermoluminescent material layer 3 pass through the quantum dot film 500, red light is emitted by the red quantum excited by the blue light and the green light, the red light and the blue light emitted by the blue light emitting element, the green light emitted by the green light emitting element and the green light emitted by the thermoluminescent material layer 3 are mixed to form white light, and the white light enters the liquid crystal display panel 200 to be used for displaying of the liquid crystal display panel 200.

In this embodiment, the wavelength of green light emitted due to excitation of the thermoluminescent material layer 3 is closer to λ than the wavelength of light emitted by the green light emitting element₀Thus, the wavelength range of the green light emitted by the backlight 300 is widened by the thermoluminescent material layer 3, and the area of the chromaticity triangle of the display device is increased, so that the color gamut of the display device is increased, and the display effect of the display device is improved.

Therefore, in order to increase the color gamut of the display device, the backlight 300 of the embodiment of the present application needs to satisfy that at least a portion of the light emitting elements 2 on the substrate 1 can emit light with a wavelength λ₁Is arranged to emit light of wavelength lambda upon heating, the layer of thermoluminescent material 3 being arranged to emit light of wavelength lambda upon heating₂Of primary color light of (A)₁And λ₂Satisfies the following conditions: lambda₂-λ₀|<|λ₁-λ₀|。

In some embodiments, the material of the thermoluminescent material layer 3 includes a resin and a rare earth phosphor. The resin is used as a matrix of the thermoluminescent material, the rare earth fluorescent powder is uniformly doped into the resin in a proper proportion, and the rare earth fluorescent powder can excite fluorescence after absorbing heat.

In this embodiment, the thermoluminescent material layer 3 is made of resin and rare-earth phosphor with low price, which is beneficial to reducing the manufacturing cost of the backlight 300. In addition, the wavelength of the light excited by heating of the thermoluminescent material layer 3 can be accurately controlled by changing the proportion of the rare earth phosphor, so that the relationship between the wavelength of the light excited by heating of the thermoluminescent material layer 3 and the wavelength of the light emitted by the light emitting element 2 can be better satisfied.

The resin may be a transparent resin. Such as 901 vinyl transparent resin, MQ silicone resin, barium sulfate transparent resin, etc. The MQ silicone resin is a silicone resin consisting of a monofunctional Si-O unit (M unit) and a tetrafunctional Si-O unit (SiQZ is called Q unit for short).

Through setting up the resin into transparent resin, can conveniently be located the light that the inside tombarthite phosphor powder of thermoluminescence material layer 3 sent like this and spout to guarantee thermoluminescence material layer 3's luminous efficacy.

The kind of the rare earth phosphor may be specifically selected according to the color of the primary color light emitted from the thermoluminescent material layer 3, and when the primary color light emitted from the thermoluminescent material layer 3 is blue, the rare earth phosphor is europium-activated barium magnesium aluminate (BaMgAl)₁₀O₁₇：Eu²⁺) (ii) a When the primary color light emitted by the thermoluminescent material layer 3 is green, the rare earth fluorescent powder is cerium terbium activated magnesium aluminate ((Ce, Te) MgAl₁O₁₉) (ii) a When the primary color light emitted by the thermoluminescent material layer 3 is red, the rare earth fluorescent powder is europium activated yttrium oxide (Y)₂O₃:Eu³⁺). By using the rare earth phosphor, the thermoluminescent material layer 3 can have high luminous efficiency and color rendering property. Meanwhile, the rare earth fluorescent powder also has the advantages of very stable physical and chemical properties, relatively fixed production process, easy synthesis and the like.

In some embodiments, the material of the thermoluminescent material layer 3 further includes among ultraviolet light absorbers, diluents and temperature regulators.

By arranging the ultraviolet light absorber in the material of the thermoluminescent material layer 3, the ultraviolet light absorber can absorb harmful ultraviolet light, thereby reducing the harm of the light emitted by the thermoluminescent material layer 3 to human bodies. By providing a diluent in the material of the thermoluminescent material layer 3, the viscosity of the thermoluminescent material can be reduced, thereby making the mixing between the individual components in the thermoluminescent material more uniform. By providing a temperature adjusting agent in the material of the thermoluminescent material layer 3, the temperature adjusting agent can adjust the temperature of the thermoluminescent material layer 3 when the backlight 300 is in operation, thereby preventing damage caused by an excessively high temperature of the thermoluminescent material layer 3.

Of course, the material of the thermoluminescent material layer 3 may be provided with one or both of an ultraviolet absorber, a diluent and a temperature regulator according to actual needs.

UV-3035 has the chemical name of Etorilin and the molecular formula C₁₈H₁₅NO₂The thermoluminescent material has better ultraviolet absorption performance and thermal stability, so that when the thermoluminescent material is heated, the thermoluminescent material is prevented from being heated and decomposed by the ultraviolet absorber.

UV-583 has the chemical name tetramethyl-4-piperidyl stearate and the molecular formula C₂₇H₅₃NO₂It has the advantages of no toxicity, no flammability, no explosion, no corrosion, good stability, etc.

UV-329 has the chemical name 2- (2 '-hydroxy-5' -tert-octylphenyl) benzotriazole, formula C₂₀H₂₅N₃O, which can effectively absorb ultraviolet light with the wavelength of 270-380 nm and has the advantages of nonflammability, nontoxicity, safety and harmlessness in use and the like.

In some embodiments, the diluent is an organic solvent, such as ethanol, gasoline, or the like. Through setting the diluent into organic solvent, resin, tombarthite phosphor powder can mix with organic solvent well like this to make more even that tombarthite phosphor powder mixes, with the luminous even of guaranteeing thermoluminescence material layer 3.

In some embodiments, the temperature modifier comprises metal particles. Since the metal particles have good thermal conductivity compared to the non-metal particles, the metal particles can rapidly absorb heat of the thermoluminescent material layer 3, so that the thermoluminescent material layer 3 can be well prevented from being excessively high in temperature.

Wherein the metal particles include at least one of iron particles, copper particles, and tungsten particles. Because the iron particles, the copper particles and the tungsten particles not only have good thermal conductivity, but also have higher melting points, the structure can be ensured not to be melted when the structure is heated while the rapid heat absorption is ensured.

In some embodiments, the material of the thermoluminescent material layer 3 is prepared from the following components: 30-150 parts of resin; 20-140 parts of rare earth fluorescent powder; 0.5 part of ultraviolet absorber; 10 parts of a diluent; 0.5 part of temperature regulator. Through the arrangement, the requirements of the luminous efficiency, the luminous intensity and the luminous uniformity of the thermoluminescent material layer 3 can be met, and meanwhile, the ultraviolet light emitted by the thermoluminescent material layer 3 can be well absorbed, and the overhigh temperature of the thermoluminescent material layer 3 is avoided.

In some embodiments, the proportion of the resin in the material of the thermoluminescent material layer 3 is 50 parts. This allows the rare-earth phosphor to have a higher concentration value, resulting in higher luminous efficiency and luminous intensity of the thermoluminescent material layer 3.

Besides the above materials, the material of the thermoluminescent material layer 3 may also be alkaline earth sulfide as a luminescent matrix, and in other embodiments, the thermoluminescent material layer 3 may also be made to emit light from the infrared region to the ultraviolet region by incorporating different metal ions as activators. For example, rare earth ions Bi can be used³⁺、Ce³⁺And Eu³⁺Alkaline earth sulfides as activators to prepare thermoluminescent materials with different fluorescence characteristics. Wherein, Eu is used³⁺The thermoluminescent colour of the alkaline earth sulphide as activator is red, expressed as Ce³⁺The thermoluminescent color of the alkaline earth sulfide as an activator is green and is Bi³⁺The thermoluminescent color of the alkaline earth sulfide as an activator is blue.

As shown in fig. 14, fig. 14 is a process diagram of a manufacturing method of the backlight 300 shown in fig. 4 and fig. 5, the manufacturing method of the backlight 300 includes the following steps: s100, covering the thermoluminescent material layer 3 on the side of the substrate 1 where the plurality of light emitting elements 2 are disposed, and connecting the thermoluminescent material layer 3 and the light emitting elements 2 in a heat conductive manner.

As shown in (1) to (4) in fig. 14 and fig. 17, fig. 17 is a flowchart illustrating a manufacturing process of the thermoluminescent material layer 3 of the backlight 300 in fig. 6 and 7, and the step S100 includes:

s120, filling the thermoluminescent material into the space between each two of the plurality of light emitting elements 2 to form the first thermoluminescent material layer 31.

The first thermoluminescent material layer 31 can be formed by a screen printing process, so that the first thermoluminescent material layer 31 has a simple manufacturing process and fewer steps, and the manufacturing efficiency of the backlight 300 is improved.

The first thermoluminescent material layer 31 is specifically formed by a screen printing process as follows: step S120 includes:

s121, as shown in (1) of fig. 14, the first photosensitive material layer 61 is covered on the side of the substrate 1 where the plurality of light emitting elements 2 are disposed to cover the plurality of light emitting elements 2.

S122, as shown in (2) of fig. 14, patterning the first photosensitive material layer 61 to remove the first photosensitive material layer 61 located laterally to each light-emitting element 2, so that a side surface of each light-emitting element 2 away from the substrate 1 is covered with the first photosensitive material layer 61.

The first photosensitive material layer 61 may be patterned by a photolithography process, for example, by providing an etching barrier layer (e.g., photoresist) on the first photosensitive material layer 61, and then patterning the first photosensitive material layer 61 by exposure, development, and the like.

S123, as shown in (3) of fig. 14, the thermoluminescent material is printed by screen printing to the space between two of the plurality of light emitting elements 2 to form the first thermoluminescent material layer 31.

S124, as shown in (4) in fig. 14, removing the surface of the light emitting element 2 on the side away from the substrate 1, which is covered with the first photosensitive material layer 61.

Wherein the first photosensitive material layer 61 can be removed by being placed into a dissolving liquid. The first photosensitive material layer 61 may be a photosensitive adhesive layer, and mainly functions to protect the light emitting element 2 and prevent the light emitting element 2 from being scratched by a scraper during the process of printing the thermoluminescent material.

As shown in (5) to (8) in fig. 14, step S100 further includes the steps of:

and S130, arranging a light-transmitting material on one side surface of each light-emitting element 2 far away from the substrate 1 to form a protective layer 4.

By providing the protective layer 4, the protective layer 4 can protect the light emitting element 2 from damage to the light emitting element 2.

In step S130, the protective layer 4 may be formed by a screen printing process, so that the manufacturing process of the protective layer 4 is simple, and the number of steps is small, thereby facilitating improvement of the manufacturing efficiency of the backlight 300.

The protective layer 4 is formed by a screen printing process in the following specific steps: the step S130 includes:

s131, as shown in (5) of fig. 14, the side of the substrate 1 where the plurality of light emitting elements 2 are disposed covers the second photosensitive material layer 62 to cover the plurality of light emitting elements 2.

S132, as shown in (6) of fig. 14, the second photosensitive material layer 62 is patterned to remove the second photosensitive material layer 62 located laterally to each light-emitting element 2, so that the surface of the first thermoluminescent material layer 31 on the side away from the substrate 1 covers the second photosensitive material layer 62.

S133, as shown in (7) of fig. 14, a light-transmitting material is printed by screen printing to a surface of one side of each light-emitting element 2 away from the substrate 1 to form the protective layer 4.

S134, as shown in (8) of fig. 14, the surface of the first thermoluminescent material layer 31 on the side away from the substrate 1 is removed to cover the second photosensitive material layer 62.

Wherein the second photosensitive material layer 62 can be removed by being placed into a dissolving liquid. The second photosensitive material layer 62 may be a photosensitive adhesive layer, and mainly functions to protect the first thermoluminescent material layer 31 and prevent the first thermoluminescent material layer 31 from being scratched by a scraper during the process of printing the thermoluminescent material.

The first thermoluminescent material layer 31 may be formed by a screen printing process, or may be formed by a photolithography process, as shown in fig. 15, where fig. 15 is a process diagram of another manufacturing method of the backlight 300 shown in fig. 4 and 5.

Step S120 includes:

s121', as shown in (1) of fig. 15, the thermoluminescent material film 71 is covered on the side of the substrate 1 where the plurality of light-emitting elements 2 are provided, so as to cover the plurality of light-emitting elements 2.

S122', as shown in (2) of fig. 15, the first etch stopper 81 is covered on the thermoluminescent material film 71.

Illustratively, the first etch stopper 81 may be a photoresist layer.

S123', as shown in (3) of fig. 15, the first etching stopper layer 81 is patterned such that a projection of the first etching stopper layer 81 on the substrate 1 is located in a space between two of the plurality of light emitting elements 2.

Among them, the first etch stopper 81 may be patterned by exposing the first etch stopper 81 to light using a mask and then placing in a developing solution to dissolve a portion of the first etch stopper 81.

S124', as shown in (4) of fig. 15, the thermoluminescent material film 71 not covered with the first etch stopper 81 is etched away by an etching process to form the first thermoluminescent material layer 31.

S125', as shown in (5) of fig. 15, the first etching stopper 81 covering the first thermoluminescent material layer 31 is removed.

The protective layer 4 may be formed by a photolithography process in addition to the screen printing process, as shown in fig. 15, and the step S130 includes:

s131', as shown in (6) of fig. 15, the side of the substrate 1 where the plurality of light emitting elements 2 are provided is covered with the light transmitting material film 72 to cover the plurality of light emitting elements 2.

S132', as shown in (7) of fig. 15, a second etching stopper layer 82 is covered on the light-transmitting material film 72.

Illustratively, the second etch stop layer 82 may be a photoresist layer.

S133', as shown in (8) of fig. 15, the second etch stopper layer 82 is patterned so that the projection of the second etch stopper layer 82 on the substrate 1 overlaps with the projections of the plurality of light emitting elements 2 on the substrate 1.

The second etching stopper layer 82 may be patterned by exposing the second etching stopper layer 82 to light using a mask and then placing the second etching stopper layer 82 in a developing solution to dissolve a portion of the second etching stopper layer 82.

S134', as shown in (9) of fig. 15, the light-transmitting material film 72 is etched away not covering the second etch stopper layer 82 by the etching process to form the protective layer 4.

S135', as shown in (10) of fig. 15, the second etching stopper 82 covering the protective layer 4 is removed.

Of course, the protection layer 4 is not limited to be formed after the first thermoluminescent material layer 31, but may be formed before the first thermoluminescent material layer 31, which is determined according to the actual situation.

As shown in fig. 16 and 17, fig. 16 is a process diagram of manufacturing the thermoluminescent material layer 3 of the backlight 300 in fig. 6 and 7. In some embodiments, before step S120, the method further includes:

s110, the thermoluminescent material is disposed at the periphery of the array formed by the plurality of light emitting elements 2 and contacts the light emitting elements 2 at the edge of the array to form the second thermoluminescent material layer 32.

By providing the second thermoluminescent material layer 32 at the periphery of the array of light emitting elements 2, not only the array of light emitting elements 2 can be better heat dissipated, but also the second thermoluminescent material layer 32 can act as a dam to prevent the thermoluminescent material from flowing toward the periphery of the substrate 1 during the process of making the first thermoluminescent material layer 31.

In some embodiments, the method for manufacturing the backlight 300 further includes the following steps:

as shown in fig. 9 and 10, the plurality of light collecting portions 51 for collecting light are formed on the light output surface 5 of the backlight 300 in S200.

By forming the plurality of light-condensing portions 51 for condensing light on the light-emitting surface 5, light loss caused by scattering of light emitted from the light-emitting surface 5 can be reduced, thereby facilitating improvement of the light utilization rate of the backlight 300.

In some embodiments, step S200 comprises: as shown in fig. 9 and 10, a plurality of light-condensing portions 51 are formed on the surface of the thermoluminescent material layer 3 remote from the substrate 1. Wherein, the plurality of light-gathering portions 51 may be formed by rolling a roller.

The light-condensing portion 51 can thus condense the light emitted by the thermoluminescent material layer 3 being heated, so as to improve the utilization rate of the light emitted by the thermoluminescent material layer 3 being heated.

In some embodiments, step S200 comprises: as shown in fig. 9 and 10, a plurality of light-condensing portions 51 are formed on the surfaces of the thermoluminescent material layer 3 and the protective layer 4 away from the substrate 1.

This can concentrate the light emitted by the light-emitting element 2 and the thermoluminescent material layer 3 to improve the utilization of the light emitted by the light-emitting element 2 and the thermoluminescent material layer 3.

The same or similar features in the embodiment of the manufacturing method of the backlight 300 as those in the embodiment of the product of the backlight 300 may specifically refer to the description in the embodiment of the product of the backlight 300, and are not repeated herein.

In the description herein, particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments or examples.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.

Claims

1. A backlight, comprising:

a substrate;

a plurality of light emitting elements disposed on one side of the substrate and having at least a partial number of the light emitting elementsThe light-emitting element can emit light with a wavelength of lambda₁The primary color light of (1);

a thermoluminescent material layer covering one side of the substrate where the plurality of light-emitting elements are arranged and in heat-conducting connection with the light-emitting elements, the thermoluminescent material layer being configured to emit light with a wavelength λ when heated₂Of said primary color light, λ₁And λ₂Satisfies the following conditions: lambda₂-λ₀|<|λ₁-λ₀L, where λ₀The wavelength values corresponding to the points of the spectral trajectory lines of the primary colors at the corners of the chromaticity diagram are shown in the chromaticity diagram.

2. The backlight of claim 1,

the primary color light is blue light and lambda₀≤λ₂<λ₁。

3. The backlight of claim 2,

each of the light emitting elements is a blue light emitting element.

4. The backlight according to any one of claims 1 to 3,

the material of the thermoluminescent material layer comprises resin and rare earth fluorescent powder.

5. The backlight of claim 4,

the resin is a transparent resin.

6. The backlight of claim 4 or 5,

the primary color light is blue light, and the rare earth fluorescent powder is europium-activated magnesium barium aluminate.

7. The backlight according to any one of claims 4 to 6,

the material of the thermoluminescent material layer further includes at least one of an ultraviolet light absorber, a diluent, and a temperature regulator.

8. The backlight of claim 7,

the ultraviolet light absorber is one of UV-3035, UV-583 and UV-329.

9. The backlight of claim 7 or 8,

the diluent is an organic solvent.

10. The backlight according to any one of claims 7 to 9,

the temperature regulator includes metal particles.

11. The backlight of claim 10,

the metal particles include at least one of iron particles, copper particles, and tungsten particles.

12. The backlight according to any one of claims 7 to 11,

the thermoluminescent material layer is prepared from the following components in parts by weight: 30-150 parts of resin; 20-140 parts of rare earth fluorescent powder; 0.5 part of ultraviolet absorber; 10 parts of the diluent; 0.5 part of temperature regulator.

13. The backlight according to any one of claims 1 to 12,

the thermoluminescent material layer includes a first thermoluminescent material layer filling a space between two of the plurality of light emitting elements.

14. The backlight of claim 13,

the thermoluminescent material layer further comprises a second thermoluminescent material layer located at the periphery of the array formed by the plurality of light emitting elements and in contact with the light emitting elements located at the edge of the array.

15. The backlight of claim 13 or 14,

the backlight source also comprises a protective layer covering the light-emitting element, and the surface of one side, far away from the substrate, of the protective layer is flush with the surface of one side, far away from the substrate, of the thermoluminescent material layer.

16. The backlight according to any one of claims 1 to 15,

the backlight source comprises a light-emitting surface, and a plurality of light-gathering parts for gathering light are arranged on the light-emitting surface.

17. The backlight of claim 16,

the light-gathering part is triangular or arched in a section parallel to the thickness direction of the substrate.

18. The backlight of claim 16 or 17,

the height of the light-gathering part is 10-20 mu m.

19. The backlight according to any one of claims 16 to 18,

the light-emitting surface comprises a side surface of the thermoluminescent material layer, which is far away from the substrate.

20. A display device, comprising:

a liquid crystal display panel;

the backlight of any one of claims 1-19;

and the quantum dot film is arranged between the backlight source and the liquid crystal display panel.

21. An electronic device comprising the backlight according to any one of claims 1 to 19.

22. A method for manufacturing the backlight source of any one of claims 1 to 19, comprising the steps of:

covering a thermoluminescent material layer on one side of the substrate where the plurality of light-emitting elements are arranged, and enabling the thermoluminescent material layer to be in heat conduction connection with the light-emitting elements.

23. The method of claim 22, wherein the step of forming the backlight further comprises,

covering a thermoluminescent material layer on one side of a substrate provided with a plurality of light-emitting elements to ensure that the thermoluminescent material layer is in heat conduction connection with the light-emitting elements, and the thermoluminescent material layer comprises:

filling a thermoluminescent material into a space between every two of the plurality of light-emitting elements to form a first thermoluminescent material layer; wherein the thermoluminescent material layer comprises the first thermoluminescent material layer.

24. The method of claim 23, wherein the step of forming the backlight further comprises,

before the thermoluminescent material is filled into the space between two of the plurality of light-emitting elements to form the first thermoluminescent material layer, the thermoluminescent material light-emitting device further comprises:

arranging a thermoluminescent material at the periphery of the array formed by the plurality of light-emitting elements and contacting the light-emitting elements at the edge of the array to form a second thermoluminescent material layer; wherein the thermoluminescent material layer comprises the second thermoluminescent material layer.

25. The method of manufacturing a backlight according to claim 23 or 24,

the first thermoluminescent material layer is manufactured by a screen printing process.

26. The method for manufacturing a backlight source according to any one of claims 22 to 25, further comprising the steps of:

and arranging a light-transmitting material on one side surface of each light-emitting element far away from the substrate to form a protective layer.

27. The method of claim 26, wherein the step of forming the backlight further comprises,

the protective layer is manufactured through a screen printing process.

28. The method for manufacturing a backlight according to any one of claims 22 to 27, further comprising the steps of:

and a plurality of light condensing parts for condensing light are formed on the light emitting surface of the backlight.

29. The method of claim 28, wherein the step of forming the backlight further comprises,

a plurality of light-condensing portions for condensing light are formed on a light-emitting surface of the backlight, and the light-condensing portions include:

and forming a plurality of light-condensing parts on the surface of the thermoluminescent material layer far away from the substrate.