CN113126361A

CN113126361A - Backlight module, electronic equipment and lamp strip

Info

Publication number: CN113126361A
Application number: CN201911422126.7A
Authority: CN
Inventors: 熊充; 余俊逸; 段宝
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2021-07-16
Also published as: WO2021135752A1

Abstract

The embodiment of the application provides a backlight module, electronic equipment and lamp strip, relates to and shows technical field. For reducing the proportion of light in the backlight that has a higher light damage index. The backlight module comprises a backlight source and a plurality of light-emitting components in the backlight source. Wherein the light emitting assembly includes a first light emitting device and a second light emitting device. The first light-emitting device comprises a first light-emitting chip and a fluorescent layer coated on the light-emitting side of the first light-emitting chip, the first light-emitting chip is used for emitting first blue light, and the first blue light is used for mixing the first blue light with light emitted by the fluorescent layer under the excitation of the first blue light to form first light. In addition, the second light-emitting device is used for emitting second blue light, and the second blue light is used for being mixed with the first light to form white light. In this case, the peak wavelength of the second blue light is greater than the peak wavelength of the first blue light.

Description

Backlight module, electronic equipment and lamp strip

Technical Field

The application relates to the technical field of display, especially, relate to a backlight unit, electronic equipment and lamp strip.

Background

Liquid Crystal Display (LCD) panels have been widely used in the field of display technology. A backlight is required in the LCD to display an image. The backlight source is provided with exciting light for exciting the fluorescent powder to emit light. For exciting the phosphor, the light with higher energy is usually used for the excitation light, and the shorter the wavelength of the light, the higher the energy and the higher the penetrating power. Therefore, the high-energy excitation light easily penetrates through the crystalline lens of the human eye and directly reaches the retina, so that the high-energy excitation light has a high ray injury index, and the light emitted from the backlight source causes certain injury to the human eye.

Disclosure of Invention

The embodiment of the application provides a backlight module, an electronic device and a lamp bar, which are used for reducing the proportion of light rays with higher light ray damage indexes in a backlight source.

In order to achieve the purpose, the technical scheme is as follows:

in a first aspect of the embodiments of the present application, a backlight module is provided, which includes a backlight source and a plurality of light emitting elements in the backlight source. The light emitting assembly comprises a first light emitting device and a second light emitting device, the first light emitting device comprises a first light emitting chip and a fluorescent layer coated on the light emitting side of the first light emitting chip, the first light emitting chip is used for emitting first blue light, and the first blue light is used for mixing the first blue light with light emitted by the fluorescent layer under the excitation of the first blue light to form first light. In addition, the second light-emitting device is used for emitting second blue light, and the second blue light is used for being mixed with the first light to form white light. In addition, the peak wavelength of the second blue light is greater than the peak wavelength of the first blue light.

As can be seen from the above, the first light emitting chip in the first light emitting device emits the first blue light with a shorter peak wavelength, that is, the short-wave blue light. The short-wave blue light can excite the fluorescent layer on the light emitting side of the first light emitting chip to emit light, and the light emitted by the fluorescent layer are mixed to form first light. In addition, a second light emitting chip in the second light emitting device emits second blue light with longer peak wavelength, namely long-wave blue light, and the long-wave blue light and the first light are mixed to form white light. Therefore, in the white light provided by the embodiment of the present application, compared with a scheme that only short-wave blue light is adopted to excite a fluorescent layer (for example, yellow fluorescent powder) to emit light and then mix the light into white light, the wavelength is shorter, the energy is high, and a part of first blue light with a high blue light damage index is occupied, the white light further includes second blue light with a longer peak wavelength and a smaller blue light damage index, so that the ratio of light with a higher blue light damage index in a backlight source can be reduced by the scheme provided by the embodiment of the present application, and therefore, the damage of light emitted by the backlight source to a human body is reduced.

Optionally, the fluorescent layer includes red phosphor and green phosphor, the red phosphor is used to emit red light under the excitation of the first blue light, and the green phosphor is used to emit green light under the excitation of the first blue light. Thus, when the first blue light excites the fluorescent layer, the first blue light can be mixed with the green light and the red light generated after exciting the fluorescent layer to generate red-yellow light, and the red-yellow light is used as the first light. Therefore, the first light red and yellow light can be used for mixing with the second blue light to generate white light.

Optionally, the light emitting layer of the first light emitting chip includes a base material and a first doping material, wherein the base material includes gallium nitride, and the first doping material includes at least one of indium and aluminum. The first doping material with the first proportion is doped in the basic material, so that the first light-emitting chip emits the peak wavelength required by the first blue light. In addition, the light emitting layer of the second light emitting chip comprises a base material and a second doping material, wherein the second doping material comprises at least one of indium and aluminum. The second doping material with the second ratio is doped in the basic material, so that the second light-emitting chip emits the peak wavelength required by the second blue light.

Optionally, the peak wavelength of the first blue light is 440nm to 460nm, the peak wavelength of the second blue light is 460nm to 490nm, and since the corresponding wavelength range is 415nm to 455nm when the damage index of the blue light is at the peak, that is, the corresponding damage index of the blue light is higher when the wavelength range is 415nm to 455nm, and the peak wavelength of the second blue light is 460nm to 490nm, which is not in the above range, the ratio of the blue light in the corresponding wavelength range when the damage index of the blue light is at the peak can be effectively reduced by using the second blue light.

Optionally, the backlight module further comprises a light guide plate, wherein the light guide plate has a top surface, a bottom surface, and a side surface located between the top surface and the bottom surface. In addition, a plurality of mesh points for guiding light are arranged on the bottom surface of the light guide plate, a backlight source is arranged on at least one side surface of the light guide plate, and a light emitting surface of the backlight source faces the side surface of the light guide plate. In this case, a part of the light emitted from the backlight is incident into the light guide plate and is totally reflected, so that the part of the light can be transmitted from the left side of the light guide plate to the right side of the light guide plate. Meanwhile, another part of the light emitted by the backlight source can be incident to the mesh points on the bottom surface of the light guide plate, and the total reflection of the light is destroyed, so that the light is emitted from the top surface of the light guide plate after being scattered by the mesh points and is provided to the display panel as a light source.

Optionally, the backlight source includes a first light bar circuit board, the light emitting assembly is disposed on the first light bar circuit board, and the first light bar circuit board is located on a side of the light emitting assembly away from the light guide plate, wherein the first light emitting device and the second light emitting device are alternately disposed, so that light emitted by the first light emitting device and the light emitted by the second light emitting device are mixed more uniformly.

Optionally, the backlight source includes a second light bar circuit board and a third light bar circuit board, wherein the first light emitting device is located on the first light bar circuit board, and the first light emitting devices of the plurality of light emitting assemblies are located in the same row. In addition, the second light emitting device is located on the second light bar circuit board, and the second light emitting devices in the plurality of light emitting assemblies are located in the same row. In this case, the first light emitting device and the second light emitting device in the same light emitting assembly are located in the same column. The second light bar circuit board is also positioned on one side of the light emitting component away from the light guide plate and is positioned on the same side with the first light bar circuit board. Because the first light emitting device and the second light emitting device are positioned in the same column, when the backlight source comprises the two lamp bar circuit boards, the first light emitting device and the second light emitting device can still be adjacently arranged, so that the light mixing effect is increased.

Optionally, the backlight module includes a first backlight source and a second backlight source. In this case, the light guide plate has a first side surface and a second side surface which are oppositely arranged, wherein the first backlight source is arranged on the first side surface, and the second backlight source is arranged on the second side surface, so that under the condition that the size of the light guide plate is larger, the problem that the brightness of the light emitted from the top surface of the light guide plate is reduced at a position far away from the backlight source due to light loss in the light transmission process when the backlight source is arranged on a single side surface can be solved.

Optionally, the backlight module further includes a first reflective sheet disposed on one side of the bottom surface of the light guide plate. The first reflector plate is used for reflecting light rays incident to the first reflector plate in the light guide plate, so that the utilization rate of the light rays can be improved.

Optionally, the backlight module further includes a second reflective sheet, wherein the second reflective sheet has a reflective surface and a back surface opposite to the reflective surface. In addition, the second reflection sheet is provided with a plurality of lamp holes penetrating through the reflection surface and the back surface opposite to the reflection surface, and the lamp holes are used for penetrating through at least one of the first light-emitting device and the second light-emitting component, so that light emitted by the backlight source can penetrate through the back surface of the second reflection sheet.

Optionally, the backlight source includes a first light bar circuit board, and the light emitting assembly is disposed on the first light bar circuit board. In order to enable the light emitted by the light emitting device to be emitted to the display panel, the first lamp strip circuit board is positioned on one side, away from the second reflector plate, of the light emitting assembly, wherein the first light emitting device and the second light emitting device are alternately arranged, so that the light emitted by the first light emitting device and the light emitted by the second light emitting device are more fully mixed.

Optionally, the backlight source includes a second light bar circuit board and a third light bar circuit board, wherein the first light emitting device is located on the first light bar circuit board, and the first light emitting devices of the plurality of light emitting assemblies are located in the same row. In addition, the second light emitting device is located on the second light bar circuit board, and the second light emitting devices in the plurality of light emitting assemblies are located in the same row, in this case, the first light emitting device and the second light emitting device in the same light emitting assembly are located in the same row, and are the same as the first light bar circuit board, and the second light bar circuit board is also located on one side of the light emitting assembly away from the second reflector plate, and is located on the same side as the first light bar circuit board.

Optionally, the backlight source includes a plurality of second light bar circuit boards and a plurality of third light bar circuit boards, wherein the second light bar circuit boards and the third light bar circuit boards are alternately arranged. Under this condition, can select the lamp strip circuit board of corresponding quantity according to the display panel size to ensure that luminance meets the requirement.

Optionally, one lamp hole corresponds to one light emitting assembly, and the first light emitting device and the second light emitting device in the same light emitting assembly penetrate through the same lamp hole, so that light emitted by the first light emitting device and the light emitted by the second light emitting device are mixed more uniformly.

Optionally, the second reflector plate is provided with a plurality of first lamp holes and a plurality of second lamp holes, wherein the first lamp holes and the second lamp holes are alternately arranged, and the adjacent first lamp holes and the adjacent second lamp holes form a lamp hole group. In this case, one lamp hole group corresponds to one light emitting assembly, and the first light emitting device in the same light emitting assembly passes through the first lamp hole in the lamp hole group, and the second light emitting device passes through the second lamp hole in the lamp hole group, so that the size specifications of the plurality of first lamp holes and the plurality of second lamp holes, and the distance between any two adjacent lamp holes can be the same, thereby being beneficial to simplifying the manufacturing process of the light emitting device.

Optionally, the backlight module further comprises a diffusion plate arranged on the light-emitting side of the backlight source, in addition, the reflection strips arranged at intervals are arranged on the reflection surface of the second reflection sheet and are in contact with the diffusion plate, in this case, the lamp hole is located between the two adjacent reflection strips, therefore, on one hand, the light of the backlight source can be emitted from the lamp hole, and after the emitted light is emitted to the reflection sheet, the light can be reflected by the emission sheet, so that the purpose of improving the utilization rate of the light is achieved. On the other hand, the light rays emitted by the first light-emitting device and the second light-emitting device can be more fully mixed under the reflection action of the two adjacent reflection strips, the light mixing effect is improved, and meanwhile, the reflection strips are in contact with the diffusion plate and also play a role in supporting the optical membrane.

Optionally, the backlight module further includes a third reflector disposed on a side of the diffusion plate facing the light emitting assembly, where at least a portion of a vertical projection of any one of the first light emitting device and the second light emitting device on the diffusion plate is located within a range of a vertical projection of the third reflector on the diffusion plate, so that light emitted from the light emitting device is emitted to the third reflector, and the third reflector reflects the emitted light to adjust brightness directly above the light emitting device, thereby preventing too strong brightness of light directly above the light emitting device.

In a second aspect of the embodiments of the present application, an electronic device is provided, where the electronic device includes a display panel and any one of the backlight modules described above, and the display panel is disposed on a light emitting side of the backlight module. The electronic device has the same technical effect as the backlight module provided by the foregoing embodiment, and details are not repeated herein.

In a third aspect of the embodiments of the present application, a light bar is provided, where the light bar includes a fourth light bar circuit board, a plurality of light emitting assemblies are disposed on the fourth light bar circuit board, and each light emitting assembly includes a first light emitting device and a second light emitting device, where the first light emitting device and the second light emitting device are alternately disposed. In addition, the first light-emitting device comprises a first light-emitting chip and a fluorescent layer coated on the light-emitting side of the first light-emitting chip, the first light-emitting chip is used for emitting first blue light, and the first blue light is used for mixing the first blue light with light emitted by the fluorescent layer under the excitation of the first blue light to form first light. The second light emitting device is used for emitting second blue light, and the second blue light is used for being mixed with the first light to form white light. In this case, the peak wavelength of the second blue light is greater than the peak wavelength of the first blue light. In the above scheme, the first light emitting chip in the first light emitting device emits the first blue light with a shorter peak wavelength, that is, the short-wave blue light. The short-wave blue light can excite the fluorescent layer on the light emitting side of the first light emitting chip to emit light, and the light emitted by the fluorescent layer are mixed to form first light. In addition, a second light emitting chip in the second light emitting device emits second blue light with longer peak wavelength, namely long-wave blue light, and the long-wave blue light and the first light are mixed to form white light. The light bar has the same technical effect as the backlight module provided by the foregoing embodiment, and the description thereof is omitted.

Drawings

Fig. 1a is a schematic structural diagram of an electronic device according to an embodiment of the present disclosure;

fig. 1b is a schematic structural diagram of another electronic device provided in the embodiment of the present application;

FIG. 1c is a schematic structural diagram of a display module in the electronic device of FIGS. 1a and 1 b;

FIG. 1d is a schematic view of a structure of an LCD panel of the display module of FIG. 1 c;

FIG. 1E is a cross-sectional view taken along line E-E of FIG. 1 d;

fig. 2a is a schematic structural diagram of a backlight source provided in this embodiment of the present application;

FIG. 2b is a cross-sectional view taken along O-O in FIG. 2 a;

FIG. 3 is a graph of the relationship between light wavelength and blue damage index;

FIG. 4 is a graph of spectral energy provided by an embodiment of the present application;

fig. 5 is a schematic structural diagram of a light emitting chip provided in an embodiment of the present application;

fig. 6 is a schematic structural diagram of a front view of a backlight module according to an embodiment of the present disclosure;

fig. 7a is a schematic structural view of a light bar circuit board according to an embodiment of the present disclosure;

fig. 7b is a schematic structural diagram of a top view of a backlight module according to an embodiment of the present disclosure;

fig. 7c is a schematic structural diagram of a top view of another backlight module according to an embodiment of the present disclosure;

fig. 8a is a schematic structural view of another light bar circuit board according to an embodiment of the present disclosure;

fig. 8b is a schematic structural diagram of a top view of another backlight module according to an embodiment of the present disclosure;

fig. 9a is a schematic structural diagram of a front view of another backlight module according to an embodiment of the present disclosure;

fig. 9b is a schematic structural diagram of a top view of another backlight module according to an embodiment of the present disclosure;

fig. 9c is a schematic structural diagram of a top view of another backlight module according to an embodiment of the present disclosure;

fig. 9d is a schematic structural diagram of a top view of another backlight module according to an embodiment of the present disclosure;

fig. 9e is a schematic structural diagram of a top view of another backlight module according to an embodiment of the present disclosure;

fig. 10 is a schematic structural diagram of a front view of another backlight module according to an embodiment of the present disclosure;

fig. 11 is a schematic structural view of another light bar circuit board provided in the embodiment of the present application.

Reference numerals:

01-an electronic device; 10-a display module; 11-middle frame; 12-a rear shell; 13-front frame; 101-LCD screen; 20-a backlight module; 100-sub-pixels; 112-a color film substrate; 113-a liquid crystal layer; 114-a color filter layer; 120-liquid crystal molecules; 111-an array substrate; 201-a first light emitting device; 202-a second light emitting device; 200-a light emitting assembly; 21-a backlight source; 221-a fluorescent layer; 211-a first light emitting chip; 212-a second light emitting chip; 501-a substrate; 502-N type semiconductor layer; 503-a light emitting layer; 505-a P-type electrode; 504-P-type semiconductor layer; 506-an N-type electrode; 403-a light guide plate; f1-top surface of light guide plate; f3-side of light guide plate; f2-light guide plate ground; f3a — first side; f3b — second side; 21 a-a first backlight; 21 b-a second backlight; 402-mesh points; 413-a first reflective sheet; 405-a first light bar circuit board; 406-a second light bar circuit board; 407-a third light bar circuit board; 901-a second reflector sheet; g-an emission surface; h-the back of the emitting surface; 902-a second light hole; 903-lamp hole; 400-a light bar circuit board; 910-a group of light holes; 102-a reflective strip; 408-a fourth light bar circuit board; 904-a third reflector sheet; 905-first lamp hole.

Detailed Description

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments.

In the following, the terms "first", "second", etc. 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," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless otherwise specified.

Further, in this application, directional terms such as "top" and "bottom" may be used, including but not limited to, those defined with respect to the schematic orientation of the components in the drawings, it being understood that such directional terms may be relative terms, which are used for descriptive and clarity purposes, and which may vary accordingly depending on the orientation of the components in the drawings.

In the present application, unless expressly stated or limited otherwise, the term "coupled" is to be construed broadly, e.g., "coupled" may be a fixed connection, a removable connection, or an integral part; may be directly connected or indirectly connected through an intermediate. Furthermore, the term "coupled" may be a manner of making electrical connections that communicate signals. "coupled" may be a direct electrical connection or an indirect electrical connection through intervening media.

The embodiment of the application provides electronic equipment. For example, as shown in fig. 1a, the electronic device 01 may comprise a mobile phone. In this case, the electronic device 01 mainly includes a display module 10, a middle frame 11 and a rear case 12. The middle frame 11 is located between the display module 10 and the rear case 12. The display module 10 and the rear shell 12 are respectively connected with the middle frame 11. The accommodating cavity formed between the rear case 12 and the middle frame 11 is used for accommodating a battery, a camera (not shown in fig. 1 a), and electronic components such as a Printed Circuit Board (PCB) shown in fig. 1 a.

Alternatively, and for example, as shown in FIG. 1b, the electronic device 01 may comprise a television. In this case, the electronic device 01 mainly includes a front frame 13, a display module 10 and a rear housing 12, and the display module 10 is disposed between the front frame 13 and the rear housing 12. Wherein, the rear shell 12 is connected with the display module 10, and the front frame 13 is connected with the rear shell 12.

Alternatively, for another example, the electronic device 01 may include a tablet computer, an in-vehicle computer, a smart wearable product (e.g., a smart watch, a smart bracelet), a Virtual Reality (VR) terminal device, an Augmented Reality (AR) terminal device, and the like.

As for any of the electronic devices 01 mentioned above, the display module 10 of the electronic device 01 may include an LCD panel 101 as shown in fig. 1c and a backlight unit (BLU) 20 located at the back of the LCD panel 101 (i.e. near one side surface of the rear case 12). The BLU20 can provide light sources to the LCD panel 101 to enable the individual sub-pixels 100 in the LCD panel 101 as shown in fig. 1d to emit light to effect image display.

In addition, as shown in fig. 1E (a cross-sectional view cut along a dotted line E-E in fig. 1 d), the LCD panel 101 may include an array substrate (array substrate)111, a Color Filter (CF) substrate 112, and a liquid crystal layer 113 located between the array substrate 111 and the color filter substrate 112. On the array substrate 111, a pixel (pixel) circuit is provided in each sub-pixel 100. The pixel circuit (not shown) can be used to control the deflection angle of the liquid crystal molecules 120 in the liquid crystal layer 113 corresponding to the position of the sub-pixel 100 where the pixel circuit is located. Therefore, the amount of light provided by the BLU20 passing through the sub-pixel 100 can be controlled to control the sub-pixel 100 to display gray scales.

In addition, in order to realize color display, the color filter substrate 112 may further include a color filter layer 114 for filtering light, and the color filter layer 114 may include a plurality of filter units. The filtering unit may filter light provided by the BLU20, such as white (W) light, so that a sub-pixel may only allow one type of light to pass through. For example, adjacent three filter units may be used to pass red (R), green (G), and blue (B) light, respectively. The sub-pixels where the three adjacent filter units R, G and B are located may form a pixel (pixel). In this way, by controlling the light transmittance of the sub-pixel R, the sub-pixel G, and the sub-pixel B in each pixel, the LCD panel 101 can display a color picture.

As described above, the BLU20 can emit white light, and the structure of the BLU20 will be described in detail below.

In some embodiments of the present application, the BLU20 described above may include a backlight 21 as shown in fig. 2 a. The backlight 21 is used to supply light to the LCD panel 101. The backlight 21 may include a plurality of light emitting elements 200. Among them, the light emitting assembly 200 may include a first light emitting device 201 and a second light emitting device 202.

As shown in fig. 2b (a cross-sectional view taken along a dotted line O-O in fig. 2 a), the first light emitting device 201 may include a first light emitting chip 211 and a fluorescent layer 221 coated on a light emitting side of the first light emitting chip 211. The first light emitting chip 211 is configured to emit first blue light a1 (as indicated by a dotted arrow in fig. 2 b). The fluorescent layer 221 is used for emitting at least one fluorescent excited light B (as indicated by the dotted arrow in fig. 2B) under excitation of the first blue light a 1. In this case, the first blue light a1 and the fluorescence excited light B can be mixed into the first light C.

The fluorescent layer 221 may include phosphor and a colloid mixed with the phosphor. The colloid can be at least one of colloid materials such as silica gel or epoxy resin. In the process of manufacturing the fluorescent layer 221, a material formed by mixing the above-mentioned colloid and the phosphor may be applied to the light emitting side of the first light emitting chip 211. Alternatively, for example, a mixture of the colloid and the phosphor may be formed into a thin film layer, and then the thin film layer may be attached to the light emitting side of the first light emitting chip 211. The above is only an example of the manufacturing process of the fluorescent layer 221, the manufacturing process of the fluorescent layer is not limited in the present application, and other manufacturing methods are not described in detail.

In some embodiments of the present application, the phosphors on the first light emitting chip 211 may include red phosphors and green phosphors. The material for the red phosphor or the material for the green phosphor may include nitride phosphor, silicate phosphor, and other phosphors.

Based on this, the red phosphor may be used to emit first fluorescent excited light under excitation of the first blue light a1, and the first fluorescent excited light may be red light. In addition, the green phosphor may be used to emit second fluorescence excited light under excitation of the first blue light a1, and the second fluorescence excited light may be green light.

In addition, when the fluorescent layer 221 includes red phosphor and green phosphor, in order to improve the efficiency of the first blue light a1 in exciting the fluorescent layer 221 to emit excitation light (e.g., red light and green light), the first blue light a1 needs to have higher energy, and thus the peak wavelength thereof is smaller, for example, the peak wavelength of the first blue light a1 may be between 400nm and 460 nm. On this basis, in order to mix the first blue light a1 with the excitation light (e.g., red light and green light) into the first light C (e.g., red yellow light), the peak wavelength of the first blue light a1 may be between 440nm and 460 nm.

In addition, as shown in fig. 2b, the second light emitting device 202 may include a second light emitting chip 212. The second light emitting chip 212 may be configured to emit second blue light a2 (as indicated by the solid arrows in fig. 2 b). The second blue light a2 may be used to mix with the first light C (e.g., red yellow light) to form white light. Therefore, the BLU20 can provide a white backlight source to the display panel 101, and as can be seen from the above, the white light can realize color display after being filtered by each filter unit in the color filter layer 114 of the color filter substrate 112.

From the above, the peak wavelength of the first blue light a1 may be between 440nm and 460 nm. However, as can be seen from FIG. 3 (a graph of wavelength versus damage index of blue light), when the wavelength of blue light is between 415nm and 455nm, the damage index of blue light reaches a peak value, for example, the maximum peak value is about 0.900. Therefore, the blue light damage index of the first blue light A1 with the peak wavelength between 440nm and 460nm is larger, so that the damage to the eyes is larger.

And the second blue light a2 emitted by the second light emitting device 202 in the BLU20 provided herein has a peak wavelength greater than that of the first blue light (e.g., the peak wavelength of the first blue light a1 may be between 440nm and 460 nm). At this time, the peak wavelength of the second blue light a2 may be between 460nm and 490 nm. As can be seen from FIG. 3, the blue damage index of the second blue light A2 with the peak wavelength between 460nm and 490nm is smaller.

With respect to the solution provided by the embodiments of the present application, in some related technologies, only short-wave blue light (for example, peak wavelength between 440nm and 450 nm) may be used to excite a fluorescent layer (for example, yellow fluorescent powder) to emit light, and then the light is mixed into white light. In the scheme, as shown in fig. 4, the wavelength of the blue light is between 415nm and 455nm, the corresponding points P1 and P4 on the abscissa, and the area (i.e., the light energy of the blue light with the wavelength between 415nm and 455 nm) enclosed by the point P3 on the curve (corresponding to the scheme of only using short-wave blue light to excite the fluorescent layer to emit light and then mixing the light into white light) occupy a larger proportion in the area (i.e., the light energy of the blue light in the whole blue light band) partially enclosed by the curve (i) and the whole blue light band (i.e., 400nm to 500nm) on the abscissa. This ratio may characterize the degree of blue light damage. Therefore, it can be known from the ratio that the blue light damage degree is larger, about 81.6%, in the scheme that the short-wave blue light only excites the fluorescent layer to emit light and then is mixed into white light, which corresponds to the curve i.

However, in the BLU20 provided in the embodiments of the present application, the backlight 21 includes a plurality of light emitting elements 200. The light emitting assembly 200 may include a first light emitting device 201 and a second light emitting device 202. Among them, the first light emitting chip 211 in the first light emitting device 201 may emit the first blue light a1 having a short peak wavelength (e.g., between 440nm to 460 nm), that is, short-wavelength blue light. The short-wave blue light is used to excite the fluorescent layer 221 on the light emitting side of the first light emitting chip 211 to emit light, and is mixed with the light emitted by the fluorescent layer 221 to form a first light C (e.g., red-yellow light). In addition, the second light emitting chip 212 in the second light emitting device 202 may emit the second blue light a2 having a longer peak wavelength (e.g., between 460nm and 490 nm), i.e., long-wavelength blue light. The long-wave blue light is used for being mixed with the first light C to form white light. Therefore, the white light emitted from the BLU20 provided by the embodiment of the present application has a short wavelength, high energy, and a high blue damage index, and the first blue light a1 only occupies a portion of the white light. The white light also comprises second blue light A2 with longer peak wavelength and smaller blue light damage index.

In this case, as shown in fig. 4, in the BLU20 provided in the embodiment of the present application, the blue light wavelength is between 415nm and 455nm, and the corresponding point P1 and point P4 on the abscissa and the area (i.e., the light energy of the blue light wavelength between 415nm and 455 nm) surrounded by the point P2 on the curve (corresponding to the solution of the present application) occupy a smaller proportion in the area (i.e., the light energy of the blue light in the entire blue light band) partially surrounded by the curve (i.e., 400nm to 500nm) and the entire blue light band (i.e., the light energy of the blue light in the entire blue light band) on the abscissa. From the above, the ratio can be used to characterize the degree of blue light damage. Therefore, according to the ratio, the blue light damage degree of the scheme corresponding to the curve II is smaller and is about 33.8%. Thereby reducing the proportion of light in the BLU20 having a higher blue light damage index and reducing the damage to the human eye.

On this basis, the light emitting process of the light emitting chip will be described by taking the first light emitting chip 211 as an example. As shown in fig. 5, the first light emitting chip 211 includes a substrate 501, an N-type semiconductor layer 502, a light emitting layer 503, and a P-type semiconductor layer 504 sequentially disposed on the substrate, and a P-type electrode 505 coupled to the P-type semiconductor layer 504 and an N-type electrode 506 coupled to the N-type semiconductor layer 502. The P-type semiconductor layer has many more holes than free electrons, and conducts electricity mainly through holes. The N-type semiconductor layer has far more free electrons than holes and conducts mainly with electrons. When voltages are applied to the P-type electrode and the N-type electrode respectively, free electrons in the N-type semiconductor layer gain energy to recombine with holes in the P-type semiconductor layer region. A large amount of energy is generated in the recombination process, and the energy is released in the light emitting layer 503 in the form of light, thereby converting electric energy into light energy, and the wavelength of the light is determined by the material of the light emitting layer.

Therefore, the light emitting wavelength of the first light emitting chip 211 can be determined by the material type and the material ratio of the light emitting layer of the first light emitting chip 211. In some embodiments of the present application, the light emitting layer 503 of the first light emitting chip 211 may include a base material and a first doping material. The base material may include gallium nitride (GaN), among others. The first doping material may include at least one of indium (In) and aluminum (Al). The indium (In) or the aluminum (Al) In the first doping material has a first composition. The first ratio is used to adjust the light emitting wavelength of the first light emitting chip 211.

Similarly, the light emitting wavelength of the second light emitting chip 212 can be determined by the material type and the material ratio of the light emitting layer of the second light emitting chip 212. In some embodiments of the present application, the light emitting layer 503 of the second light emitting chip 212 may include a base material and a second dopant material. Wherein the second doping material may include at least one of indium and aluminum. The indium or aluminum in the second doping material has a second composition ratio. The second ratio is used for adjusting the light emitting wavelength of the second light emitting chip 212.

On the basis, the first proportion is different from the second proportion. The present application does not limit the specific values of the first ratio and the second ratio, as long as the peak wavelength of the second blue light a2 emitted by the second light-emitting chip 212 is greater than the peak wavelength of the first blue light a1 emitted by the first light-emitting chip 211.

In addition, in order to mix the first blue light a1 emitted by the first light emitting chip 211 and the red light emitted by the fluorescent layer 221 under the excitation of the first blue light a1 and the filtered light into the first light C, and the first light C can be mixed with the second blue light a2 emitted by the second light emitting chip 212 into white light, the coefficients x, y and z of three primary colors, i.e., R, G, B, can be adjusted according to the color matching equation, so that x, y and z are equal to each other, thereby achieving the purpose of mixing the three primary colors into white light. The color matching equation is as follows:

C＝xX+yY+zZ (1)

in the color matching equation (1), C represents a color; x, Y, Z represent the units of three primary colors (i.e., R, G, B), respectively; the coefficients x, y, and z for the three primary colors (i.e., R, G, B) are tristimulus values. The tristimulus values represent the degree of stimulation of the human retina by the three primary colors (i.e., R, G, B), respectively.

Based on this, when the first mixture ratio of the light emitting layer in the first light emitting chip 211, the second mixture ratio of the light emitting layer in the second light emitting chip 212, and the type or mixture ratio of the material of the phosphor in the phosphor layer 221 of the first light emitting device 201 are determined, the light energy x, y, and z of the three primary colors, i.e., R, G, B, can be adjusted by adjusting the areas of the light emitting layers of the first light emitting chip 211 and the second light emitting chip 212 and adjusting the current connecting to the light emitting chips (i.e., the first light emitting chip 211 and the second light emitting chip 212), so that x is equal to y is equal to z. Illustratively, the magnitudes of the light energies x, y, and z of the three primary colors, i.e., R, G, B, are proportional to the area of the light emitting chip or the current drawn.

The above description is made of the first light emitting chip 211 and the second light emitting chip 212 in the backlight 21 of the BLU 20. The structure of the BLU20 having this backlight 21 will be described below as an example.

Example 1

In this example, the BLU20 is a side-entry backlight module. As shown in fig. 6, the BLU20 includes a light guide plate 403, and a backlight 21 disposed on at least one side F3 of the light guide plate 403. The light emitting surface of the backlight 21 faces the side surface of the light guide plate 403.

The light guide plate 403 includes a top surface F1 and a bottom surface F2, and a side surface F3 of the light guide plate 403 is located between the top surface F1 and the bottom surface F2. Further, a plurality of dots 402 for guiding light are provided on the bottom surface F2.

In this case, a part of the light emitted from the backlight 21 (as indicated by the dotted arrow in fig. 6) incident into the light guide plate 403 is totally reflected, so that the part of the light can be transmitted from the left side of the light guide plate 403 to the right side of the light guide plate 403. In addition, another part of the light emitted from the backlight 21 (as shown by the solid arrow in fig. 6) is incident on the dots 402 on the bottom surface F2 of the light guide plate 403, and the total reflection of the light is destroyed, so that the light is scattered by the dots 402 and then exits from the top surface F1 of the light guide plate 403, and is provided to the display panel 101 as a light source.

The BLU20 may further include a first reflective sheet 413 disposed on a bottom surface F2 of the light guide plate 403. The first reflection sheet 413 may be used to reflect light incident on the bottom surface F2 of the light guide plate 403, so that the light utilization rate may be improved.

As can be seen from the above, the backlight 21 includes a plurality of light emitting elements 200 as shown in fig. 2 a. Among them, the light emitting assembly 200 may include a first light emitting device 201 and a second light emitting device 202. In some embodiments of the present application, as shown in fig. 7a, the backlight 21 further includes a first light bar circuit board 405. The first light emitting device 201 and the second light emitting device 202 of the light emitting assembly 200 are disposed on the first light bar circuit board 405. The first light emitting device 201 and the second light emitting device 202 on the first light bar circuit board 405 may be alternately arranged.

In this case, as shown in fig. 7b, when the backlight 21 shown in fig. 7a is disposed on the side surface F3 of the light guide plate 403, and the light emitting surface of the backlight 21 faces the side surface F3 of the light guide plate 403, in the same light emitting assembly 200, as can be seen from the above, the second blue light a2 emitted by the second light emitting device 202 is mixed with the first light C emitted by the first light emitting device 201 (red-yellow light generated by mixing the red light and the green light generated by exciting the first blue light a1 by the first blue light a1 and the fluorescent layer 221) to form white light. The white light emitted from the light emitting device 200 into the light guide plate 403 exits from the top surface F1 of the light guide plate 403 at the dots 402 on the bottom surface F2 of the light guide plate 403.

The above description is given by taking an example in which the BLU20 is provided with one backlight 21. In other embodiments of the present application, as shown in fig. 7c, a first backlight 21a and a second backlight 21b may be respectively disposed on two opposite sides of the light guide plate 403, for example, the first side F3a and the second side F3 b. Thus, when the light guide plate 403 is large in size, the problem of the light guide plate 403 that the brightness of the light emitted from the top surface F1 is reduced at a position far from the backlight 21 due to light loss during light transmission when the backlight 21 is disposed on a single side surface F3 can be alleviated.

Alternatively, in other embodiments of the present application, as shown in fig. 8a, the backlight 21 may include a second light bar circuit board 406 and a third light bar circuit board 407. The first light emitting devices 201 are located on the second light bar circuit board 406, and the first light emitting devices 201 in the plurality of light emitting assemblies 200 are located in the same row (for example, along the X direction in fig. 8 a). Moreover, the second light emitting devices 202 are disposed on the third light bar circuit board 407, and the second light emitting devices 202 in the plurality of light emitting assemblies 200 are disposed in the same row. In addition, the first light emitting device 201 and the second light emitting device 202 in the same light emitting assembly 200 are located in the same column (e.g., in the Y direction in fig. 8 a).

The plane XOY in the X direction and the Y direction may be parallel or substantially parallel to the side surface F3 of the light guide plate 403 on which the backlight 21 is provided.

In addition, the third light bar circuit board 407 and the second light bar circuit board 406 are located on the same side of the light guide plate 403. In this case, as shown in fig. 8b (a top view of the backlight 21), the row of first light-emitting devices 201 is located on the side face F3 of the light guide plate 403. In addition, the row of second light emitting devices 202 located below the row of first light emitting devices 201 in fig. 8a is also located at the side face F3 of the light guide plate 403, and is shielded by the row of first light emitting devices 201 above in fig. 8 b.

Similarly, in the same light emitting assembly 200 shown in fig. 8a, the second blue light a2 emitted from the second light emitting device 202 is mixed with the first light C emitted from the first light emitting device 201 to form white light. The white light is incident on the light guide plate 403 and then exits from the top surface F1 of the light guide plate 403 under the light guiding action of the dots 402.

In fig. 8b, the BLU20 is illustrated as an example in which the backlight 21 is provided on one side surface of the light guide plate 403. As described above, in other embodiments of the present application, backlights may be disposed on two opposite sides of the light guide plate 403.

Example two

In this example, the BLU20 is a direct type backlight module. As shown in fig. 9a, the BLU20 includes a second reflective sheet 901 and the backlight 21. The second reflective sheet 901 has a reflective surface G for reflecting light and a back surface H opposite to the reflective surface G, and the light exit surface of the backlight 21 faces the display panel 101. The second reflection sheet 901 is provided with a plurality of lamp holes 903 penetrating the reflection surface G and the back surface H of the second reflection sheet 901.

As can be seen from the above, the backlight 21 includes a plurality of light emitting elements 200 as shown in fig. 2 a. Among them, the light emitting assembly 200 may include a first light emitting device 201 and a second light emitting device 202. In some embodiments of the present application, as shown in fig. 9a, the backlight 21 further includes at least one light bar circuit board 400, and the light bar circuit board 400 is located on a side of the light emitting assembly 200 away from the second reflective sheet 901 (i.e. a side where the back surface H of the second reflective sheet 901 is located).

In some embodiments of the present application, the backlight 21 may include a first light bar circuit board 405 as shown in fig. 9 b. Based on this, all the light emitting components 200 can be disposed on the first light bar circuit board 405. In this case, the first light emitting device 201 and the second light emitting device 202 of the light emitting assembly 200 are disposed on the first light bar circuit board 405. In addition, the first light bar circuit board 405 may include a plurality of rows, the first light emitting device 201 and the second light emitting device 202 in each row may be alternately disposed, and the first light emitting device 201 and the second light emitting device 202 pass through the same light hole 903.

In other embodiments of the present application, the backlight 21 may include a plurality of first light bar circuit boards 405 as shown in fig. 9 c. Each first light bar circuit board 405 has a row (along the X direction) of light emitting assemblies 200 disposed thereon. The first light emitting device 201 and the second light emitting device 202 in the same row of light emitting assemblies 200 are both disposed on the same first light bar circuit board 405. Moreover, the first light emitting device 201 and the second light emitting device 202 on the first light bar circuit board 405 may be alternately disposed, and the first light emitting device 201 and the second light emitting device 202 pass through the same light hole 903.

As can be seen from the above, the second blue light a2 emitted by the second light emitting device 202 is mixed with the first light C emitted by the first light emitting device 201 (the red light generated by the first blue light a1 and the fluorescent layer 221 excited by the first blue light a1, and the red-yellow light after filtering and mixing) to form white light. The white light incident from the light emitting assembly 200 exits from the display panel 101.

In other embodiments of the present application, the backlight 21 may include a plurality of light bar circuit boards 400. For example, as shown in fig. 9d, the backlight 21 may include at least one second light bar circuit board 406 and at least one third light bar circuit board 407. When the backlight 21 includes a plurality of second light bar circuit boards 406 and a plurality of third light bar circuit boards 407, the second light bar circuit boards 406 and the third light bar circuit boards 407 may be alternately arranged as shown in fig. 9 c.

Based on this, the first light emitting devices 201 are located on the second light bar circuit board 406, and the first light emitting devices 201 in the plurality of light emitting assemblies 200 are located in the same row (e.g., along the X direction in fig. 9 d). In addition, the second light emitting devices 202 are disposed on the third light bar circuit board 407, and the second light emitting devices 202 in the plurality of light emitting assemblies 200 are disposed in the same row. On this basis, the first light emitting device 201 and the second light emitting device 202 in the same light emitting assembly 200 are located in the same column (e.g., along the Y direction in fig. 9 d).

It should be noted that, as can be seen from the above description, the BLU20 in this example is a direct type, and the plane XOY in the X direction and the Y direction in fig. 9d may be parallel or approximately parallel to the light exit side surface (the surface for displaying images) of the display panel 101 shown in fig. 9 a.

The above description is made by taking the same lamp hole 903 on the second reflector 901 as an example of the first light emitting device 201 and the second light emitting device 202 in the same light emitting assembly 200. In other embodiments of the present application, as shown in fig. 9e, the second reflective sheet 901 is provided with a plurality of first lamp holes 905 and a plurality of second lamp holes 902. The first lamp holes 905 and the second lamp holes 902 are alternately arranged. The adjacent first lamp hole 905 and second lamp hole 902 form a lamp hole group 910. One light emitting module 200 corresponds to one light emitting module 910, and the first light emitting device 201 in the same light emitting module 200 passes through the first light hole 905 in the light hole module 910, and the second light emitting device 202 passes through the second light hole 902 in the light hole module 910.

For the direct type BLU20 of this example, as shown in fig. 10, the BLU20 further includes a diffuser 902, and the diffuser 902 is disposed on the light emitting side of the backlight 21 for uniformly diffusing the light emitted from the light emitting assembly 200.

Accordingly, the diffuser plate 902 and a plurality of optical films (e.g., prism sheets) on the diffuser plate 902 are supported. As shown in fig. 10, a plurality of reflective strips 102 are provided at intervals on the reflective surface G of the second reflective sheet 901, and the reflective strips 102 are in contact with the diffusion plate 902. In this way, the diffusion plate and the optical film can be supported by the plurality of reflection bars 102.

In addition, in order to further increase the utilization rate of the light emitted from the backlight 21, the outer surface of the reflective strip 102 may reflect the light. In this case, as shown in fig. 10, the lamp hole 903 is positioned between two adjacent reflective strips 102, so that at least one light emitting device, for example, one lamp hole 903 corresponding to one light emitting assembly 200, may be disposed between two adjacent reflective strips 102, and the first light emitting device 201 and the second light emitting device 202 in the light emitting assembly 200 may be disposed between the two adjacent reflective strips 102.

Therefore, on one hand, the light of the backlight 21 can be emitted from the lamp hole 903, and after the emitted light is emitted to the second reflection sheet 901, the second reflection sheet 901 reflects the light, so that the purpose of improving the utilization rate of the light is achieved. On the other hand, the light rays emitted by the first light emitting device 201 and the second light emitting device 202 can be mixed more fully under the reflection action of the two adjacent reflection bars 102, and the light mixing effect is improved.

In addition, in order to avoid too strong brightness of light directly above the light emitting device (e.g., the first light emitting device 201 or the second light emitting device 202), the light provided by the BLU20 is not uniform. As shown in fig. 10, the BLU20 further includes a third reflective sheet 904 disposed on a side of the diffusion plate 902 facing the light emitting assembly 200, wherein at least a portion of a vertical projection of any one of the first light emitting device 201 and the second light emitting device 202 on the diffusion plate 902 is located within a range of a vertical projection of the third reflective sheet 904 on the diffusion plate 902, so that the third reflective sheet 904 can reflect light emitted from the first light emitting device 201 or the second light emitting device 202 after the light is emitted to the third reflective sheet 904, thereby adjusting the brightness directly above the light emitting devices.

The embodiment of the application provides a light bar, as shown in fig. 11, the light bar may include a fourth light bar circuit board 408, wherein a plurality of light emitting assemblies 200 are disposed on the fourth light bar circuit board 408, the light emitting assemblies 200 may include a first light emitting device 201 and a second light emitting device 202, and the first light emitting device and the second light emitting device are alternately disposed.

As shown in fig. 2b (a cross-sectional view taken along a dotted line O-O in fig. 11), the first light emitting device 201 may include a first light emitting chip 211 and a fluorescent layer 221 coated on a light emitting side of the first light emitting chip 211. The first light emitting chip 211 is configured to emit first blue light a1 (as indicated by a dotted arrow in fig. 2 b). The fluorescent layer 221 is used for emitting at least one fluorescent excited light B (as indicated by the dotted arrow in fig. 2B) under excitation of the first blue light a 1. In this case, the first blue light a1 and the fluorescence excited light B can be mixed into the first light C.

The fluorescent layer 221 may include phosphor and a phosphor colloid. The colloid can be at least one of colloid materials such as silica gel or epoxy resin. In the process of manufacturing the fluorescent layer 221, a material formed by mixing the above-mentioned colloid and the phosphor may be applied to the light emitting side of the first light emitting chip 211. Alternatively, for example, the colloid and the phosphor may be mixed to form a thin film layer, and then the thin film layer may be attached to the light emitting side of the first light emitting chip 211 by bonding. The above is only an example of the manufacturing process of the fluorescent layer 221, the manufacturing process of the fluorescent layer is not limited in the present application, and other manufacturing methods are not described in detail.

In some embodiments of the present application, the fluorescent layer may include red phosphor and green phosphor, and the arrangement of the red phosphor and the green phosphor is the same as that described above, and is not repeated herein.

In addition, when the fluorescent layer 221 includes red phosphor and green phosphor, in order to improve the efficiency of the first blue light a1 in exciting the fluorescent layer 221 to emit excitation light (e.g., red light and green light), the first blue light a1 needs to have higher energy, and thus has a smaller peak wavelength, for example, the peak wavelength of the first blue light a1 may be between 400nm and 460 nm. On this basis, in order to mix the first blue light a1 with the excitation light (e.g., red light and green light) into the first light C (e.g., red yellow light), the peak wavelength of the first blue light a1 may be between 440nm and 460 nm.

In addition, as shown in fig. 2b, the second light emitting device 202 may include a second light emitting chip 212. The second light emitting chip 212 may be configured to emit second blue light a2 (as indicated by the solid arrows in fig. 2 b). The second blue light a2 may be used to mix with the first light C (e.g., red yellow light) to form white light.

From the above, the peak wavelength of the first blue light a1 can be between 440nm and 460nm, however, as can be seen from fig. 3 (graph of wavelength and damage index of blue light), when the wavelength of blue light is between 415nm and 455nm, the damage index of blue light reaches a peak value, for example, the maximum peak value is about 0.900. Therefore, the blue light damage index of the first blue light A1 with the peak wavelength between 440nm and 460nm is larger, so that the damage to the eyes is larger.

The peak wavelength of the second blue light a2 emitted by the second light emitting device 202 in the light bar provided by the present application is greater than the peak wavelength of the first blue light (for example, the peak wavelength of the first blue light a1 may be between 440nm and 460 nm). At this time, the peak wavelength of the second blue light a2 may be between 460nm and 490nm, and the second blue light a2 is mixed with the first light C to form white light. As can be seen from FIG. 3, the blue damage index of the second blue light A2 with the peak wavelength between 460nm and 490nm is smaller.

In this case, compared with a scheme that only short-wave blue light (for example, peak wavelength is between 440nm and 450 nm) is used to excite a fluorescent layer (for example, yellow fluorescent powder) to emit light, and then the fluorescent layer is mixed into white light, the first blue light a1 with a short wavelength, high energy, and a high blue damage index is only occupied in a part of the white light emitted by the light bar provided by the embodiment of the present application. The white light also comprises second blue light A2 with longer peak wavelength and smaller blue light damage index. Therefore, the proportion of light with higher blue light damage index in white light can be reduced, and the damage to human eyes is reduced.

In addition, the light emitting wavelength of the first light emitting chip 211 can be determined by the material type and the material ratio of the light emitting layer of the first light emitting chip 211. In some embodiments of the present application, the light emitting layer of the first light emitting chip 211 may include a base material and a first dopant material. Similarly, the light emitting wavelength of the second light emitting chip 212 can be determined by the material type and the material ratio of the light emitting layer of the second light emitting chip 212. In some embodiments of the present application, the light emitting layer of the second light emitting chip 212 may include a base material and a second doping material, and in this case, the light emitting wavelengths of the first light emitting chip 211 and the second light emitting chip 212 may be changed by adjusting a material ratio of the first doping material and the second doping material, which is the same as the above description and is not repeated herein.

On this basis, in order to mix the first blue light a1 emitted by the first light emitting chip 211 and the red light emitted by the fluorescent layer 221 under the excitation of the first blue light a1 with filtering to form the first light C, and the first light C may be mixed with the second blue light a2 emitted by the second light emitting chip 212 to form white light, the coefficients x, y, and z of three primary colors (i.e., R, G, B) may be adjusted according to the color matching equation, so that x ═ y ═ z is achieved, thereby achieving the purpose of mixing to form white light, and the specific adjustment method is the same as the above description, which is not repeated herein.

The above description is only an embodiment of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions within the technical scope of the present disclosure should be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A backlight module is characterized by comprising a backlight source, wherein the backlight source comprises a plurality of light-emitting components; the light emitting assembly includes:

the first light-emitting device comprises a first light-emitting chip and a fluorescent layer coated on the light-emitting side of the first light-emitting chip; the first light-emitting chip is used for emitting first blue light; the first blue light is used for being mixed with light emitted by the fluorescent layer under the excitation of the first blue light to form first light;

a second light emitting device for emitting a second blue light; the second blue light is used for being mixed with the first light to form white light; wherein a peak wavelength of the second blue light is greater than a peak wavelength of the first blue light.

2. A backlight module according to claim 1, wherein the phosphor layer comprises:

the red fluorescent powder is used for emitting red light under the excitation of the first blue light;

the green fluorescent powder is used for emitting green light under the excitation of the first blue light; and the first blue light, the green light and the red light are mixed to emit red and yellow light, and the red and yellow light is used as the first light.

3. The backlight module according to claim 1 or 2,

the light emitting layer of the first light emitting chip comprises a basic material and a first doping material; the base material comprises gallium nitride; the first doping material comprises at least one of indium and aluminum; the indium or the aluminum in the first doping material has a first mixture ratio; the first proportion is used for adjusting the light-emitting wavelength of the first light-emitting chip;

the light emitting layer of the second light emitting chip comprises the base material and a second doping material; the second doping material comprises at least one of indium and aluminum; the indium or the aluminum in the second doping material has a second proportion; the second proportion is used for adjusting the light-emitting wavelength of the second light-emitting chip;

the first ratio is different from the second ratio.

4. A backlight module according to claim 1, wherein the peak wavelength of the first blue light is between 440nm-460 nm; the peak wavelength of the second blue light is between 460nm and 490 nm.

5. A backlight module according to claim 1, further comprising a light guide plate; the light guide plate is provided with a top surface, a bottom surface and a side surface positioned between the top surface and the bottom surface; a plurality of dots for guiding light are arranged on the bottom surface;

the backlight source is arranged on at least one side face of the light guide plate; the light emitting surface of the backlight faces the side face of the light guide plate; and the light rays incident into the light guide plate by the light emitting component are used for being emitted from the top surface at the mesh points.

6. The backlight module of claim 5, wherein the backlight source comprises a first light bar circuit board; the light emitting assembly is arranged on the first light bar circuit board; the first light bar circuit board is located on one side, away from the light guide plate, of the light emitting assembly, and the first light emitting devices and the second light emitting devices are arranged in an alternating mode.

7. A backlight module according to claim 5, wherein the backlight source comprises:

the first light bar circuit board is provided with a plurality of first light emitting components, and the first light emitting components are arranged in a same row; the second light bar circuit board is positioned on one side of the light emitting assembly, which is far away from the light guide plate;

the second light emitting devices are positioned on the third light bar circuit board, and the second light emitting devices in the plurality of light emitting assemblies are positioned in the same row; the first light-emitting device and the second light-emitting device in the same light-emitting assembly are positioned in the same column; the third light bar circuit board is located on one side, away from the light guide plate, of the light emitting assembly, and is located on the same side face of the light guide plate as the second light bar circuit board.

8. The backlight module according to claim 5, wherein the backlight module comprises a first backlight source and a second backlight source;

the light guide plate is provided with a first side surface and a second side surface which are oppositely arranged; the first backlight source is arranged on the first side face, and the second backlight source is arranged on the second side face.

9. The backlight module according to any one of claims 5-8, further comprising a first reflective sheet disposed on a side of the bottom surface of the light guide plate; the first reflection sheet is used for reflecting light rays incident to the bottom surface of the light guide plate in the light guide plate.

10. The backlight module according to claim 1, further comprising a second reflective sheet; the second reflection sheet has a reflection surface and a back surface opposite to the reflection surface;

the second reflector plate is provided with a plurality of lamp holes penetrating through the reflecting surface and the back surface; the lamp hole is used for penetrating through at least one of the first light-emitting device and the second light-emitting device.

11. The backlight module of claim 10, wherein the backlight source comprises a first light bar circuit board; the light emitting assembly is arranged on the first light bar circuit board; the first light bar circuit board is located on one side, away from the second reflector plate, of the light emitting assembly, and the first light emitting device and the second light emitting device are arranged in an alternating mode.

12. A backlight module according to claim 10, wherein the backlight source comprises:

the first light bar circuit board is provided with a plurality of first light emitting components, and the first light emitting components are arranged in a same row; the second lamp strip circuit board is positioned on one side of the light-emitting assembly, which is far away from the second reflector plate;

the second light emitting devices are positioned on the third light bar circuit board, and the second light emitting devices in the plurality of light emitting assemblies are positioned in the same row; the first light-emitting device and the second light-emitting device in the same light-emitting assembly are positioned in the same column; the third light bar circuit board is positioned on one side of the light-emitting component far away from the second reflector plate.

13. The backlight module of claim 12, wherein the backlight source comprises a plurality of second light bar circuit boards and a plurality of third light bar circuit boards; the second light bar circuit board and the third light bar circuit board are arranged alternately.

14. A backlight module according to any of claims 11-13,

one lamp hole corresponds to one light emitting assembly, and the first light emitting device and the second light emitting device in the same light emitting assembly penetrate through the same lamp hole.

15. A backlight module according to any of claims 11-13,

the second reflector plate is provided with a plurality of first lamp holes and a plurality of second lamp holes; the first lamp holes and the second lamp holes are alternately arranged; the adjacent first lamp hole and the second lamp hole form a lamp hole group;

one light hole group corresponds to one light emitting assembly, the first light emitting device in the same light emitting assembly penetrates through the first light hole in the light hole group, and the second light emitting device penetrates through the second light hole in the light hole group.

16. A backlight module according to claim 10, further comprising:

the diffusion plate is arranged on the light emitting side of the backlight source;

the reflecting strips are arranged at intervals, are arranged on the reflecting surface of the second reflecting sheet and are in contact with the diffusion plate; the lamp hole is positioned between two adjacent reflecting strips; the reflecting strips are used for reflecting the light rays emitted by the backlight source.

17. A backlight module according to claim 16, further comprising a plurality of third reflective sheets arranged at intervals;

the third reflector plate is arranged on one side, facing the light emitting assembly, of the diffusion plate; at least a part of a vertical projection of any one of the first light emitting device and the second light emitting device on the diffusion plate is located within a range of a vertical projection of one of the third reflection sheets on the diffusion plate.

18. An electronic device comprising a display panel and the backlight module according to any one of claims 1-17; the display panel is arranged on the light-emitting side of the backlight module.

19. A light bar, comprising:

a fourth light bar circuit board; the plurality of light emitting components are arranged on the fourth light bar circuit board;

the light emitting assembly includes:

a second light emitting device for emitting a second blue light; the second blue light is used for being mixed with the first light to form white light; wherein the peak wavelength of the second blue light is greater than the peak wavelength of the first blue light;

wherein the first light emitting devices and the second light emitting devices are alternately arranged.

20. The light bar of claim 19, wherein the fluorescent layer comprises:

21. The light bar of claim 19 or 20,

the first ratio is different from the second ratio.

22. The light bar of claim 19, wherein the peak wavelength of the first blue light is between 440nm-460 nm; the peak wavelength of the second blue light is between 460nm and 490 nm.