Light emitting device, backlight module and display panel

Abstract

This disclosure provides a light-emitting device, a backlight module, and a display panel. The light-emitting device includes: a circuit board, a plurality of first light-emitting units, and a plurality of second light-emitting units, all located on the circuit board; the first light-emitting unit includes at least one violet light-emitting diode chip; the second light-emitting unit includes at least two light-emitting diode chips and a phosphor layer covering the at least two light-emitting diode chips, the at least two light-emitting diode chips including a blue light-emitting diode chip and a violet light-emitting diode chip, and the second light-emitting unit emits white light.

Description

Technical Field

[0001] This disclosure relates to the field of display technology, and in particular to a light-emitting device, a backlight module, and a display panel. Background Technology

[0002] A backlight module is a device that provides a light source in a display device.

[0003] The related technology provides a backlight module, which includes a circuit board and multiple light-emitting units, all of which are electrically connected to the circuit board. Each light-emitting unit includes a blue light-emitting diode chip and phosphor, thereby emitting white light.

[0004] According to related technologies, the blue light emitted by the aforementioned backlight module has a higher energy, which can cause photochemical damage to the retina, accelerate oxidative damage to macular cells, and cause harm to the user's vision. Summary of the Invention

[0005] This disclosure provides a light-emitting device, a backlight module, and a display panel that can reduce the spectral energy of blue light, thus protecting the eyes. The technical solution is as follows:

[0006] On one hand, a light-emitting device is provided, the light-emitting device comprising:

[0007] The light-emitting device includes: a circuit board, a plurality of first light-emitting units and a plurality of second light-emitting units, wherein the plurality of first light-emitting units and the plurality of second light-emitting units are all located on the circuit board;

[0008] The first light-emitting unit includes at least one violet light-emitting diode chip;

[0009] The second light-emitting unit includes at least two light-emitting diode chips and a fluorescent layer covering the at least two light-emitting diode chips. The at least two light-emitting diode chips include blue light-emitting diode chips and violet light-emitting diode chips, and the second light-emitting unit emits white light.

[0010] Optionally, the peak emission wavelength range of the violet light-emitting diode chip in the first light-emitting unit is 400–410 nm.

[0011] Optionally, the peak emission wavelength ranges of the violet light-emitting diode chip and the blue light-emitting diode chip of the second light-emitting unit are 400-410nm and 457.5-465nm, respectively.

[0012] Optionally, the plurality of first light-emitting units and the plurality of second light-emitting units are arranged in a row on the circuit board, and the first light-emitting units and the second light-emitting units are arranged alternately.

[0013] Optionally, the first light-emitting unit includes two violet light-emitting diode chips connected in series.

[0014] Optionally, the second light-emitting unit includes a blue light-emitting diode chip and a violet light-emitting diode chip, wherein the blue light-emitting diode chip and the violet light-emitting diode chip are connected in series.

[0015] Optionally, the emission spectrum of the light-emitting device has a first wavelength peak and a second wavelength peak, the first wavelength peak wavelength range is 390-420 nm, the second wavelength peak wavelength is 435-475 nm, and the ratio of the relative value of the first wavelength peak to the relative value of the second wavelength peak is 4:1 to 6:1.

[0016] Optionally, the fluorescent layer is a mixture of phosphor and adhesive, wherein the phosphor includes yellow phosphor and red phosphor, the yellow phosphor is yellow phosphor with an emission wavelength of 545-555nm, and the red phosphor is red phosphor with an emission wavelength of 620-640nm.

[0017] On the other hand, a backlight module is provided, the backlight module including a light-emitting device and a current controller, the light-emitting device being the light-emitting device described above, and the current controller being used to control the current of at least one first light-emitting unit according to the current of at least one second light-emitting unit, or to control the current of at least one second light-emitting unit according to the current of at least one first light-emitting unit.

[0018] On the other hand, a display panel is provided, the display panel comprising:

[0019] A backlight module and a liquid crystal panel; the liquid crystal panel is located on the light-emitting surface of the backlight module.

[0020] The beneficial effects of the technical solutions provided in this disclosure are:

[0021] In this embodiment, a plurality of first light-emitting units and a plurality of second light-emitting units are disposed on a circuit board as a backlight module. Each second light-emitting unit includes at least two light-emitting diode (LED) chips, comprising a violet (violet) LED chip and a blue LED chip, both emitting white light. Compared to related technologies that use a blue LED chip with a phosphor layer to form white light, this second light-emitting unit reduces the blue light spectral energy in the emitted white light by adding a violet LED chip. Furthermore, under a certain current, the violet light spectral energy of this second light-emitting unit is a certain multiple of that of the blue light, thereby minimizing blue light damage. However, since current fluctuations can easily cause the violet light spectrum energy to be difficult to reach a certain multiple of that of blue light, a first light-emitting unit containing only a violet light-emitting diode chip is set up. By controlling the current of the first light-emitting unit, the violet light spectrum energy emitted by the first light-emitting unit is controlled, which compensates for the violet light spectrum energy of the second light-emitting unit. This allows the violet light spectrum energy to reach a certain multiple of that of blue light again, effectively reducing the photochemical damage to the retina and the oxidative damage to macular cells caused by blue light, reducing the harm to the user's vision, and making the backlight module and display device using this light-emitting device have an eye-protection effect. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of a light-emitting device provided in an embodiment of this disclosure;

[0024] Figure 2 This is a schematic diagram of the structure of the first light-emitting unit provided in an embodiment of this disclosure;

[0025] Figure 3 This is a schematic diagram of the structure of the second light-emitting unit provided in an embodiment of this disclosure;

[0026] Figure 4 This is a schematic diagram of the structure of a backlight module provided in an embodiment of this disclosure;

[0027] Figure 5 This is a top view of the structure of a side-lit backlight module provided in an embodiment of this disclosure;

[0028] Figure 6 This is a top view of the structure of a direct-lit backlight module provided in an embodiment of this disclosure;

[0029] Figure 7This is a schematic diagram of a display panel provided in an embodiment of this disclosure;

[0030] Figure 8 This is a flowchart of a method for fabricating a light-emitting device according to an embodiment of this disclosure;

[0031] Figure 9 This is a flowchart of a backlight module manufacturing method provided in an embodiment of the present disclosure;

[0032] Figure 10 This is a schematic diagram of the structure of the first light-emitting unit during the manufacturing process of the backlight module provided in this embodiment of the disclosure;

[0033] Figure 11 This is a schematic diagram of the structure of the second light-emitting unit during the manufacturing process of the backlight module provided in this embodiment of the disclosure;

[0034] Figure 12 This is a schematic diagram of the backlight module circuit provided in an embodiment of this disclosure;

[0035] Figure 13 This is a spectral diagram of a light-emitting unit after passing through a light guide plate, provided in an embodiment of this disclosure;

[0036] Figure 14 This is a spectral diagram of light from a light-emitting unit after passing through a light guide plate, a diffuser plate, and a liquid crystal panel, according to an embodiment of this disclosure.

[0037] Figure 15 It is a spectrum diagram of a light-emitting unit provided by related technologies after the light from a common blue light source with phosphor passes through a light guide plate, a diffuser plate, and a liquid crystal panel;

[0038] Figure 16 These are the spectra of blue and violet light bands under different currents provided in the embodiments of this disclosure.

[0039] The attached figures are labeled as follows:

[0040] 100: Backplate; 101: Circuit board; 102: First light-emitting unit; 103: Second light-emitting unit; 104: Current controller; 105: Light guide plate; 106: Diffuser plate; 107: Reflective layer;

[0041] 201: Support; 202: Support pin; 203: LED chip; 204: Wire; 205: Phosphor layer; 206: Silicone layer;

[0042] 1031: First TVS tube; 1032: Second TVS tube;

[0043] 2031: Purple light-emitting diode chip; 2032: Blue light-emitting diode chip;

[0044] 1: Positive electrode of the first light-emitting unit; 2: Negative electrode of the first light-emitting unit; 3: Positive electrode of the second light-emitting unit; 4: Negative electrode of the second light-emitting unit;

[0045] 10: Backlight module; 20: LCD panel. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be described in further detail below with reference to the accompanying drawings.

[0047] In related technologies, LEDs with traditional structures use blue light chips with wavelengths of 447.5–455 nm, which are excited by phosphors to form white light. Blue light with wavelengths of 447.5–455 nm is quite harmful to the human eye.

[0048] Figure 1 This is a schematic diagram of the structure of a light-emitting device provided in an embodiment of this disclosure. See also... Figure 1 The light-emitting device includes: a circuit board 101, a plurality of first light-emitting units 102 and a plurality of second light-emitting units 103, all of which are located on the circuit board 101.

[0049] Figure 2 This is a schematic diagram of the structure of the first light-emitting unit provided in an embodiment of this disclosure. See also... Figure 2 The first light-emitting unit 102 includes at least one violet light-emitting diode chip 2031.

[0050] Figure 3 This is a schematic diagram of the structure of the second light-emitting unit provided in an embodiment of this disclosure. See also... Figure 3 The second light-emitting unit 103 includes at least two light-emitting diode chips 203 and a fluorescent layer 205 covering the at least two light-emitting diode chips 203. The at least two light-emitting diode chips 203 include a blue light-emitting diode chip 2032 and a purple light-emitting diode chip 2031, and the second light-emitting unit 103 emits white light.

[0051] In this embodiment, a plurality of first light-emitting units and a plurality of second light-emitting units are disposed on a circuit board as a backlight module. Each second light-emitting unit includes at least two light-emitting diode (LED) chips, comprising a violet (violet) LED chip and a blue LED chip, both emitting white light. Compared to related technologies that use a blue LED chip with a phosphor layer to form white light, this second light-emitting unit reduces the blue light spectral energy in the emitted white light by adding a violet LED chip. Furthermore, under a certain current, the violet light spectral energy of this second light-emitting unit is a certain multiple of that of the blue light, thereby minimizing blue light damage. However, since current fluctuations can easily cause the violet light spectrum energy to be difficult to reach a certain multiple of that of blue light, a first light-emitting unit containing only a violet light-emitting diode chip is set up. By controlling the current of the first light-emitting unit, the violet light spectrum energy emitted by the first light-emitting unit is controlled, which compensates for the violet light spectrum energy of the second light-emitting unit. This allows the violet light spectrum energy to reach a certain multiple of that of blue light again, effectively reducing the photochemical damage to the retina and the oxidative damage to macular cells caused by blue light, reducing the harm to the user's vision, and making the backlight module and display device using this light-emitting device have an eye-protection effect.

[0052] In this embodiment of the disclosure, the peak emission wavelength range of the violet light-emitting diode chip 2031 of the first light-emitting unit 102 is 400-410nm.

[0053] In this embodiment of the disclosure, the peak emission wavelength ranges of the violet light-emitting diode chip 2031 and the blue light-emitting diode chip 2032 of the second light-emitting unit 103 are 400-410nm and 457.5-465nm, respectively.

[0054] In this embodiment, the blue light-emitting diode chip using the aforementioned wavelength can excite phosphors with the violet light-emitting diode chip to form white light, thus weakening the spectral energy of the blue light and providing eye protection. Furthermore, the 457.5–465 nm blue light reduces the harmful effects of blue light compared to the 447.5–455 nm blue light in related technologies.

[0055] In this embodiment, the emission spectrum of the light-emitting device assembled from the first light-emitting unit 102 and the second light-emitting unit 103 has a first wavelength peak and a second wavelength peak. The wavelength range of the first wavelength peak is 390–420 nm, and the wavelength range of the second wavelength peak is 435–475 nm. The ratio of the relative values ​​of the first wavelength peak and the second wavelength peak is 4:1 to 6:1. With the above ratio, the blue light absorption of the backlight module is reduced to less than one-fifth of the spectrum, thus providing eye protection.

[0056] For example, the ratio of the relative peak values ​​of the first wavelength and the relative peak values ​​of the second wavelength is 5:1.

[0057] See you again Figure 1 Multiple first light-emitting units 102 and multiple second light-emitting units 103 are arranged in a row on the circuit board 101. This configuration of the backlight module is suitable for side-lit backlights. The first light-emitting units 102 and the second light-emitting units 103 are arranged alternately. The alternating arrangement of the first and second light-emitting units allows the violet light in the first light-emitting units to better compensate for the blue light spectral energy in the second light-emitting units, ensuring that the energy ratio of blue and violet light is maintained at the required multiple, and making the light output of the backlight module more uniform.

[0058] In other implementations, multiple first light-emitting units 102 and multiple second light-emitting units 103 can also be arranged in multiple columns, which is suitable for direct-lit backlights.

[0059] like Figure 1 As shown, the light-emitting device also includes: a first transient voltage suppressor (TVS) 1031 and a second TVS tube 1032;

[0060] The first TVS tube 1031 is connected in parallel with multiple first light-emitting units 102, and the second TVS tube 1032 is connected in parallel with multiple second light-emitting units 103.

[0061] In this embodiment, the light-emitting unit, connected in parallel with the TVS diode, can protect the circuit from large current surges and improve the stability of the backlight module.

[0062] In this embodiment, the first light-emitting unit 102 includes two violet light-emitting diode chips 2031 connected in series. The two violet light-emitting diodes enable the first light-emitting unit to emit violet light sufficient to compensate for the violet spectral energy in the second light-emitting unit, ensuring that the energy ratio of blue-violet light is maintained at the required multiple, without requiring too many LED chips and increasing costs.

[0063] In other embodiments, the first light-emitting unit 102 includes at least three violet light-emitting diode chips 2031.

[0064] In this embodiment, the second light-emitting unit 103 includes a blue light-emitting diode chip 2032 and a violet light-emitting diode chip 2031, which are connected in series. The blue and violet light-emitting diode chips can emit white light to reduce the energy of the blue light spectrum, and since only one blue light-emitting diode chip 2032 and one violet light-emitting diode chip 2031 are used, the cost is sufficiently low.

[0065] In other embodiments, the second light-emitting unit 103 includes at least two blue light-emitting diode chips 2032 and at least two violet light-emitting diode chips 2031.

[0066] In this embodiment of the disclosure, the first light-emitting unit 102 further includes a silicone layer 206, which covers at least one violet light-emitting diode chip 2031. The silicone layer can protect the violet light-emitting diode chip and will not affect the violet light spectrum energy emitted by the violet light-emitting diode chip.

[0067] In this embodiment, the fluorescent layer 205 in the second light-emitting unit 103 is a mixture of phosphor and adhesive. The phosphor includes yellow phosphor and red phosphor. The yellow phosphor emits light with a wavelength of 545–555 nm, and the red phosphor emits light with a wavelength of 620–640 nm. Using yellow phosphor and red phosphor of the above wavelengths can achieve white light output from the second light-emitting unit and reduce blue light spectral energy, thus meeting the requirements for eye protection.

[0068] In this embodiment, the phosphor content of the phosphor layer 205 in the second light-emitting unit 103 is 15-30%. Using the above-mentioned proportion of phosphor ensures both normal backlight brightness and purer color of the emitted white light.

[0069] For example, the phosphor content is 20%.

[0070] In this embodiment of the disclosure, the circuit board 101 can be a flexible printed circuit (FPC).

[0071] In this embodiment of the disclosure, the first light-emitting unit 102 and the second light-emitting unit 103 further include a bracket 201, a bracket pin 202 and a wire 204;

[0072] The light-emitting diode chip 203 is electrically connected to the bracket pin 202 on the bracket pin 202. The light-emitting diode chips 203 are electrically connected to each other through wires 204. The light-emitting diode chips 203 located on both sides are electrically connected to the bracket pin 202 through wires 204.

[0073] In this implementation, the light-emitting unit can set up multiple light-emitting diode chips together through a bracket, and can also protect the light-emitting diodes; it is electrically connected through pins and wires to form good electrical conduction.

[0074] In this embodiment of the disclosure, the material of the stent 201 may be a composite polymer material such as polyphthalamide (PPA), polycyclohexylenedimethylene terephthalate (PCT), epoxy molding compound (EMC), and sheet molding compound (SMC).

[0075] For example, the material of the support 201 is PPA.

[0076] In this embodiment of the disclosure, the bracket 201 is shaped like a circular bowl.

[0077] In this embodiment of the disclosure, the diameter of the cup in the support 201 can be 0.5 to 0.7 mm.

[0078] For example, the diameter of the cup in the support 201 is 0.6 mm.

[0079] In this embodiment, the support pin 202 can be made of metal such as iron, copper, or steel, with a layer of nickel, silver, or gold plated on the surface.

[0080] For example, the support pin 202 can be made of copper metal with a layer of nickel plated on it.

[0081] In this embodiment of the disclosure, the conductor 204 can be a metal conductor such as silver, gold, copper or an alloy.

[0082] For example, conductor 204 is a copper metal conductor.

[0083] In this embodiment, the wire 204 connecting the two LED chips 203 is an M-shaped arc. The M-shaped arc can effectively improve the fracture resistance of the wire between the two LED chips and improve the yield of the LEDs.

[0084] In this embodiment, the wire 204 connecting the LED chip 203 and the bracket pin 202 is a T-shaped arc. The T-shaped arc can effectively improve the fracture resistance of the wire between the LED chip and the bracket pin, thereby improving the yield of the LED.

[0085] Optionally, the T-shaped arc is soldered to the bracket pin by placing the end of the wire to ground, thus increasing the soldering area between the T-shaped arc and the bracket pin. This ground-tight connection increases the contact area between the wire and the bracket pin, improving the stability of the LED.

[0086] For example, the diameter of the solder joint between the T-shaped arc and the bracket pin is 30 to 100 mm, such as 55 mm.

[0087] In this embodiment, the emission wavelength of the violet light-emitting diode chip 2031 can be 400–410 nm. Using a violet light-emitting diode chip with the aforementioned wavelength can reduce the spectral energy of the blue light emitted by the blue light-emitting diode chip, thus protecting the eyes.

[0088] Figure 4 This is a schematic diagram of the structure of a backlight module provided in an embodiment of this disclosure. See also... Figure 4 The backlight module further includes a current controller 104, which is used to acquire the detected current of the second light-emitting unit 103; determine the current of the first light-emitting unit 102 corresponding to the current of the second light-emitting unit 103 based on the correspondence between the current of the second light-emitting unit 103 and the current of the first light-emitting unit 102; and control the first light-emitting unit 102 using the determined current of the first light-emitting unit 102.

[0089] In this implementation, by acquiring the detected current of the second light-emitting unit, which reflects the multiple relationship between the violet and blue light spectral energies in the light emitted by the current second light-emitting unit, and controlling the current of the first light-emitting unit for violet light compensation based on the current correspondence, the multiple relationship between the violet and blue light spectral energies emitted by the first and second light-emitting units can be better controlled in different current environments, thus achieving an eye protection effect.

[0090] For example, the current controller 104 may include a current detection unit, a calculation unit, and a current control unit. The current detection unit is used to detect the current of the second light-emitting unit 103; the calculation unit is used to determine the current of the first light-emitting unit 102 corresponding to the current of the second light-emitting unit 103; and the current control unit is used to control the current of the first light-emitting unit 102.

[0091] The current controller 104 can be implemented using integrated circuits or chips.

[0092] Figure 5 This is a top view of the structure of a side-lit backlight module provided in an embodiment of this disclosure. See also... Figure 5 The backlight module may also include a light guide plate 105 and a diffuser plate 106; the light-emitting surfaces of a plurality of first light-emitting units 102 and a plurality of second light-emitting units 103 are facing the light-incident surface of the light guide plate 105, and the diffuser plate 106 is located on the light-emitting surface of the light guide plate 105.

[0093] In this implementation, a side-lit backlight is achieved through a light guide plate. By using the aforementioned side-lit structured light emitted from the side, the thickness of the backlight module can be reduced, enabling its application in tablets, mobile phones, learning machines, educational devices, displays, and other fields.

[0094] In this embodiment, the light guide plate 105 may be made of polymethyl methacrylate, polycarbonate or polystyrene.

[0095] For example, the light guide plate 105 can be a light guide plate made of polymethyl methacrylate.

[0096] In this embodiment, the second light-emitting unit 103, composed of a violet light-emitting diode chip 2031 and a blue light-emitting diode chip 2032, emits light with an energy ratio of 2 to 4:1 for the violet and blue light spectra. This ratio significantly reduces blue light absorption in the second light-emitting unit, thus protecting the eyes.

[0097] When the current of the second light-emitting unit 103 makes the energy ratio of the violet light spectrum and the blue light spectrum 4:1, there is no need to compensate through the first light-emitting unit 102, and the current of the first light-emitting unit 102 can be controlled to be 0.

[0098] When the current of the second light-emitting unit 103 makes the energy ratio of the violet light spectrum and the blue light spectrum smaller, the current of the first light-emitting unit 102 is increased, thereby compensating the energy of the violet light spectrum and the blue light spectrum to 4 to 5:1.

[0099] In this embodiment of the disclosure, the current of the second light-emitting unit 103 is controlled to be 0 to 300 mA, and the current of the first light-emitting unit 102 is controlled to be 0 to 500 mA, and the current is adjustable within the range.

[0100] For example, when the current of the second light-emitting unit 103 is A, the corresponding relationship determines that the current of the first light-emitting unit 102 needs to be controlled as B. At this time, the ratio of the sum of the spectral energies of the violet light emitted by the second light-emitting unit 103 and the violet light emitted by the first light-emitting unit 102 to the spectral energy of the blue light emitted by the second light-emitting unit 103 meets the requirements. A is selected within the range of 0 to 300 mA, and B is selected within the range of 0 to 500 mA.

[0101] Figure 6 This is a top view of the structure of a direct-lit backlight module provided in an embodiment of this disclosure. See also... Figure 6 The backlight module may also include a diffuser plate 106.

[0102] Multiple first light-emitting units 102 and multiple second light-emitting units 103 are located between the diffuser plate 106 and the circuit board 101.

[0103] By adopting the above-mentioned direct-lit structure, since there is no light guide plate, the energy loss during the light refraction process is reduced.

[0104] In this embodiment, the diffuser plate 106 may be made of materials such as silicone, epoxy resin, or acrylic.

[0105] For example, the diffuser plate 106 is made of silicone.

[0106] See you again Figure 6 The backlight module may also include a backplate 100 and a reflective layer 107, with a circuit board 101 on the backplate 100 and the reflective layer 107 covering the backplate 100 and the circuit board 101.

[0107] In this embodiment of the disclosure, the back plate 100 can be a metal back plate, such as a metal back plate that can be stamped by a punching die.

[0108] Figure 7 This is a schematic diagram of a display panel provided in an embodiment of this disclosure. See also... Figure 7 The display panel includes a backlight module 10 and a liquid crystal panel 20; the liquid crystal panel 20 is located on the light-emitting surface of the backlight module 10. The backlight module 10 can be... Figures 4 to 6 The backlight module 10 shown in any of the images.

[0109] Figure 8 This is a flowchart illustrating a method for fabricating a light-emitting device according to an embodiment of this disclosure. See also... Figure 8 The method includes the following steps:

[0110] S11. Make multiple first light-emitting units and multiple second light-emitting units.

[0111] S12. Install multiple light-emitting units onto a circuit board, with multiple first light-emitting units connected in series and multiple second light-emitting units connected in series. Each first light-emitting unit includes at least one violet light-emitting diode chip, and each second light-emitting unit includes at least two light-emitting diode chips, including a blue light-emitting diode chip and a violet light-emitting diode chip. The second light-emitting unit emits white light.

[0112] In this embodiment, a plurality of first light-emitting units and a plurality of second light-emitting units are disposed on a circuit board as a backlight module. Each second light-emitting unit includes at least two light-emitting diode (LED) chips, comprising a violet (violet) LED chip and a blue LED chip, both emitting white light. Compared to related technologies that use a blue LED chip with a phosphor layer to form white light, this second light-emitting unit reduces the blue light spectral energy in the emitted white light by adding a violet LED chip. Furthermore, under a certain current, the violet light spectral energy of this second light-emitting unit is a certain multiple of that of the blue light, thereby minimizing blue light damage. However, since current fluctuations can easily cause the violet light spectrum energy to be difficult to reach a certain multiple of that of blue light, a first light-emitting unit containing only a violet light-emitting diode chip is set up. By controlling the current of the first light-emitting unit, the violet light spectrum energy emitted by the first light-emitting unit is controlled, which compensates for the violet light spectrum energy of the second light-emitting unit. This allows the violet light spectrum energy to reach a certain multiple of that of blue light again, effectively reducing the photochemical damage to the retina and the oxidative damage to macular cells caused by blue light, reducing the harm to the user's vision, and making the display device using the light-emitting device and backlight module have an eye-protection effect.

[0113] Figure 9 This is a flowchart illustrating a backlight module fabrication method according to an embodiment of this disclosure. See also... Figure 9 The method includes the following steps:

[0114] S21, Provide a bracket.

[0115] In this embodiment of the disclosure, the stent may be made of composite polymer materials such as PPA, PCT, EMC and SMC.

[0116] For example, the material of the support is PPA.

[0117] In this embodiment of the disclosure, the support is shaped like a circular bowl.

[0118] In this embodiment of the disclosure, the diameter of the support bowl can be 0.5 to 0.7 mm.

[0119] For example, the diameter of the support bowl is 0.6 mm.

[0120] In this embodiment of the disclosure, the support is obtained by grooving the carrier material with a laser to obtain a circular bowl-shaped structure.

[0121] S22. Fabricate bracket pins on the bracket.

[0122] In this embodiment, the support pins can be made of metals such as iron, copper, and steel, with a layer of nickel, silver, or gold plated on the surface.

[0123] For example, the support pins can be made of copper metal with a layer of nickel plated on the surface.

[0124] S23. Install the LED chip, and electrically connect the LED chip to the bracket pins.

[0125] Figure 10 This is a schematic diagram of the structure of the first light-emitting unit during the manufacturing process of the backlight module provided in this embodiment. Figure 10 As shown, the violet light-emitting diode chip 2031 is electrically connected to the bracket pin 202 on the bracket pin 202.

[0126] Figure 11 This is a schematic diagram of the structure of the second light-emitting unit during the manufacturing process of the backlight module provided in this embodiment. Figure 11 As shown. The light-emitting diode chip 203 includes a violet light-emitting diode chip 2031 and a blue light-emitting diode chip 2032. The light-emitting diode chip 203 is electrically connected to the bracket pin 202 on the bracket pin 202.

[0127] In this embodiment of the present disclosure, the peak emission wavelength range of the violet light-emitting diode chip of the first light-emitting unit is 400-410nm.

[0128] In this embodiment of the disclosure, the peak emission wavelength ranges of the violet light-emitting diode chip and the blue light-emitting diode chip of the second light-emitting unit are 400-410nm and 457.5-465nm, respectively.

[0129] In this embodiment, the blue light-emitting diode chip using the aforementioned wavelength can excite phosphors with the violet light-emitting diode chip to form white light, thus weakening the spectral energy of the blue light and providing eye protection. Furthermore, the 457.5–465 nm blue light reduces the harmful effects of blue light compared to the 447.5–455 nm blue light in related technologies.

[0130] In this embodiment, the emission spectrum of the light-emitting device assembled from the first and second light-emitting units has a first wavelength peak and a second wavelength peak. The wavelength range of the first wavelength peak is 390–420 nm, and the wavelength range of the second wavelength peak is 435–475 nm. The ratio of the relative values ​​of the first and second wavelength peaks is 4:1 to 6:1. With the aforementioned ratio, the blue light absorption of the backlight module is reduced to less than one-fifth of the spectrum, thus providing eye protection.

[0131] For example, the ratio of the relative peak values ​​of the first wavelength and the relative peak values ​​of the second wavelength is 5:1.

[0132] In this embodiment, the second light-emitting unit, composed of a violet light-emitting diode chip and a blue light-emitting diode chip, emits light with an energy ratio of 2 to 4:1 for the violet and blue light spectra. This ratio significantly reduces blue light absorption in the second light-emitting unit, thus protecting the eyes.

[0133] When the current of the second light-emitting unit makes the energy ratio of the violet light spectrum and the blue light spectrum 4:1, there is no need to compensate through the first light-emitting unit, and the current of the first light-emitting unit 102 can be controlled to be 0.

[0134] When the current of the second light-emitting unit makes the energy ratio of the violet light spectrum and the blue light spectrum smaller, the current of the first light-emitting unit is increased, thereby compensating the energy of the violet light spectrum and the blue light spectrum to 4:1 to 6:1.

[0135] In this embodiment of the disclosure, the current of the second light-emitting unit is controlled to be 0-300mA, and the current of the first light-emitting unit is controlled to be 0-500mA, and the current is adjustable within the range.

[0136] For example, when the current of the second light-emitting unit is A, the corresponding relationship determines that the current of the first light-emitting unit needs to be controlled as B. At this time, the ratio of the sum of the spectral energies of the violet light emitted by the second light-emitting unit and the violet light emitted by the first light-emitting unit to the spectral energy of the blue light emitted by the second light-emitting unit meets the requirements. A is selected within the range of 0 to 300 mA, and B is selected within the range of 0 to 500 mA.

[0137] For example, the light-emitting diode chip is fixed to the bracket pin by a eutectic method using spot flux.

[0138] S24. Make wires. The LED chips are electrically connected to each other through wires. The LED chips on both sides are electrically connected to the bracket pins through wires.

[0139] In this embodiment of the disclosure, a wire bonding machine is used to bond metal wires to chip electrodes and a substrate under the action of temperature, pressure, and ultrasound.

[0140] In this embodiment of the disclosure, the conductor can be a metal wire such as silver, gold, copper or an alloy.

[0141] For example, the conductor is a copper wire.

[0142] In this embodiment, the wire connecting the two LED chips is an M-shaped arc. The M-shaped arc can effectively improve the breakage resistance of the wire between the two LED chips, thereby improving the yield of the LEDs.

[0143] In this embodiment, the wire connecting the LED chip and the bracket pin is a T-shaped arc. The T-shaped arc can effectively improve the fracture resistance of the wires connecting the LED chip and the bracket pin, thereby improving the yield of the LED.

[0144] Optionally, the T-shaped arc is soldered to the bracket pin by placing the end of the wire to ground, thus increasing the soldering area between the T-shaped arc and the bracket pin. This ground-tight connection increases the contact area between the wire and the bracket pin, improving the stability of the LED.

[0145] For example, the diameter of the solder joint between the T-shaped arc and the bracket pin is 30 to 100 mm, such as 55 mm.

[0146] S25. Fabricate the colloidal layer in the first light-emitting unit and the fluorescent layer in the second light-emitting unit. The colloidal layer and the fluorescent layer are located inside the support and cover the light-emitting diode chip.

[0147] In this embodiment, the colloidal layer in the first light-emitting unit is a methyl silicone layer, and the fluorescent layer in the second light-emitting unit is a mixture of yellow phosphor, red phosphor, and adhesive.

[0148] In this embodiment, the phosphor content of the phosphor layer in the second light-emitting unit is 15-30%. Using the above-mentioned proportion of phosphor ensures both normal backlight brightness and a purer color of emitted white light.

[0149] For example, the phosphor content is 20%.

[0150] In this embodiment, the fluorescent layer in the second light-emitting unit is a mixture of phosphor and adhesive. The phosphor includes yellow phosphor and red phosphor. The yellow phosphor emits light with a wavelength of 545–555 nm, and the red phosphor emits light with a wavelength of 620–640 nm. Using yellow phosphor and red phosphor of the above wavelengths can achieve white light output and reduce blue light spectral energy, thus meeting the requirements for eye protection.

[0151] S26. Connect the first light-emitting unit and the second light-emitting unit to the circuit board to form an electrical path.

[0152] The circuit board also has a first TVS diode and a second TVS diode. After the first and second light-emitting units are set up, the first light-emitting unit is connected in parallel with the first TVS diode. The second light-emitting unit is connected in parallel with the second TVS diode.

[0153] In this embodiment, the light-emitting unit, connected in parallel with the TVS diode, can protect the circuit from large current surges and improve the stability of the light-emitting diode.

[0154] For example, step S26 may include:

[0155] The first step is to place an appropriate amount of conductive material on the pins of the circuit board.

[0156] In the embodiments disclosed herein, the conductive material may be silver paste, solder paste, etc.

[0157] For example, the conductive material can be solder paste.

[0158] In this embodiment of the disclosure, an appropriate amount of conductive material is placed on the mounting position of the circuit board by means of printing or dispensing / spraying the valve body.

[0159] For example, an appropriate amount of conductive material is placed on the mounting position of the circuit board by printing.

[0160] The second step involves high-temperature curing to form an electrical pathway.

[0161] In this embodiment of the disclosure, the first light-emitting unit and the second light-emitting unit are fixed to the mounting position on the circuit board by a pick-and-place machine or a die bonder.

[0162] For example, the first light-emitting unit and the second light-emitting unit are fixed to the mounting position on the circuit board by a pick-and-place machine.

[0163] In other embodiments, the light-emitting unit can also be formed on a circuit board using a chip-on-board (COP) method.

[0164] In this embodiment, multiple first light-emitting units and multiple second light-emitting units are arranged in a row on a circuit board. This configuration of the backlight module is suitable for side-lit backlights. The first and second light-emitting units are arranged alternately. This alternating arrangement allows the violet light in the first light-emitting units to better compensate for the blue light spectral energy in the second light-emitting units, ensuring that the energy ratio of blue and violet light is maintained at the required multiple, and making the light output of the backlight module more uniform.

[0165] In this embodiment, the first light-emitting unit includes two violet light-emitting diode (LED) chips connected in series. The two violet LEDs enable the first light-emitting unit to emit violet light sufficient to compensate for the violet spectral energy in the second light-emitting unit, ensuring the energy ratio of blue-violet light is maintained at the required multiple, without requiring too many LED chips and increasing costs.

[0166] In other embodiments, the first light-emitting unit includes at least three violet light-emitting diode chips.

[0167] In this embodiment, the second light-emitting unit includes a blue light-emitting diode (LED) chip and a violet light-emitting diode (UV) chip, which are connected in series. The blue and UV LED chips can emit white light to reduce the energy of the blue light spectrum, and since only one blue and one UV LED chip are used, the cost is sufficiently low.

[0168] In other embodiments, the second light-emitting unit includes at least two blue light-emitting diode chips and at least two violet light-emitting diode chips.

[0169] The third step is to perform reflow soldering.

[0170] In this embodiment of the disclosure, the mounted first light-emitting unit and the second light-emitting unit are fixed to the circuit board by soldering with solder paste.

[0171] S27. Connect the circuit board to the current controller electrically.

[0172] In this embodiment of the disclosure, the current controller may be integrated on a circuit board.

[0173] In other embodiments, the current controller may also be set up separately and then connected to the circuit board.

[0174] In this embodiment of the disclosure, the current controller is used to acquire the detected current of the second light-emitting unit; based on the correspondence between the current of the second light-emitting unit and the current of the first light-emitting unit, determine the current of the first light-emitting unit corresponding to the current of the second light-emitting unit; and control the first light-emitting unit using the determined current of the first light-emitting unit.

[0175] In this implementation, by acquiring the detected current of the second light-emitting unit, which reflects the multiple relationship between the violet and blue light spectral energies in the light emitted by the current second light-emitting unit, and controlling the current of the first light-emitting unit for violet light compensation based on the current correspondence, the multiple relationship between the violet and blue light spectral energies emitted by the first and second light-emitting units can be better controlled in different current environments, thus achieving an eye protection effect.

[0176] For example, the current controller may include a current detection unit, a calculation unit, and a current control unit. The current detection unit is used to detect the current of the second light-emitting unit; the calculation unit is used to determine the current of the first light-emitting unit corresponding to the current of the second light-emitting unit; and the current control unit is used to control the current of the first light-emitting unit.

[0177] Current controllers can be implemented using integrated circuits or chips.

[0178] Figure 12 This is a schematic diagram of the backlight module circuit provided in an embodiment of this disclosure. Figure 12 As shown.

[0179] Multiple first light-emitting units 102 are connected in series. Current flows out from the positive electrode 1 of the first light-emitting unit 102, passes through the first light-emitting unit 102, and flows to the negative electrode 2 of the first light-emitting unit. A first TVS tube 1031 is connected in parallel across the two ends of the multiple first light-emitting units 102.

[0180] Multiple second light-emitting units 103 are connected in series. Current flows out from the positive electrode 3 of the second light-emitting unit 103, passes through the second light-emitting unit 103, and flows to the negative electrode 4 of the second light-emitting unit 103. A second TVS tube 1032 is connected in parallel across the two ends of the multiple second light-emitting units 103.

[0181] S28. Assemble the light guide plate and diffuser plate.

[0182] In this light guide plate, multiple first light-emitting units, multiple second light-emitting units, and TVS tubes are located on the side of the light guide plate, and a diffuser plate is located on the light-emitting surface of the light guide plate.

[0183] In this embodiment of the disclosure, the light guide plate may be made of polymethyl methacrylate, polycarbonate or polystyrene.

[0184] For example, the light guide plate can be a light guide plate made of polymethyl methacrylate.

[0185] In this embodiment, the diffuser plate can be made of materials such as silicone, epoxy resin, or acrylic. Silicone diffuser plates have excellent weather resistance and flexibility; epoxy resin diffuser plates have good mechanical strength and electrical insulation; acrylic diffuser plates have high light transmittance and are easy to process, and can be adjusted according to the uniformity of light emission.

[0186] For example, the diffuser plate is made of silicone.

[0187] Figure 13 This is a spectral diagram of a light-emitting unit after passing through a light guide plate, provided in an embodiment of this disclosure; Figure 14 This is a spectral diagram of light from a light-emitting unit after passing through a light guide plate, a diffuser plate, and a liquid crystal panel, according to an embodiment of this disclosure. Figure 15 It is a spectrum diagram of a light-emitting unit provided by related technologies, after the light from a common blue light source with phosphor passes through a light guide plate, a diffuser plate, and a liquid crystal panel.

[0188] refer to Figures 13-15The horizontal axis represents wavelength in nanometers; the vertical axis represents spectral efficiency. It is evident that the backlight module provided in this embodiment, compared to backlight modules provided by related technologies, exhibits a significant decrease in blue light spectral efficiency after passing through the light guide plate, diffuser plate, and liquid crystal panel. This weakens the spectral energy of blue light, effectively reducing photochemical damage to the retina and oxidative damage to macular cells caused by blue light, thus minimizing harm to the user's vision.

[0189] This backlight module provides eye protection for display devices and can be used in tablets, laptops, monitors, and televisions.

[0190] Figure 16 These are the spectra of blue and violet light bands under different currents provided in embodiments of this disclosure. Figure 16 The horizontal axis represents wavelength in nanometers; the vertical axis represents spectral apparent efficiency. The lines from bottom to top correspond to currents of 5mA, 10mA, 15mA, 20mA, 25mA, 30mA, 35mA, 40mA, 45mA, 50mA, 55mA, and 60mA, respectively. The first peak from left to right represents the violet band, and the second peak represents the blue band. It is clear that the spectral apparent efficiency in the violet band is significantly affected by the current.

[0191] It should be noted that, Figure 16 The effect of different currents on the spectral energy of blue and violet light is only shown. Typically, the current used by the light-emitting unit is controlled to be several hundred milliamps, at which point the spectral energy of violet light is higher than that of blue light.

[0192] The above description is merely an optional embodiment of this disclosure and is not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A light-emitting device, characterized in that, The light-emitting device includes: a circuit board (101), a plurality of first light-emitting units (102) and a plurality of second light-emitting units (103), wherein the plurality of first light-emitting units (102) and the plurality of second light-emitting units (103) are all located on the circuit board (101); The first light-emitting unit (102) includes at least one violet light-emitting diode chip (2031). The second light-emitting unit (103) includes at least two light-emitting diode chips (203) and a fluorescent layer (205) covering the at least two light-emitting diode chips (203). The at least two light-emitting diode chips (203) include a blue light-emitting diode chip (2032) and a purple light-emitting diode chip (2031), and the second light-emitting unit (103) emits white light. The first light-emitting unit (102) is used to compensate the violet light spectral energy of the second light-emitting unit (103) so that the violet light spectral energy reaches 4 to 6 times the blue light spectral energy.

2. The light-emitting device according to claim 1, characterized in that, The peak emission wavelength range of the violet light-emitting diode chip (2031) of the first light-emitting unit (102) is 400~410nm.

3. The light-emitting device according to claim 2, characterized in that, The peak emission wavelength ranges of the violet light-emitting diode chip (2031) and the blue light-emitting diode chip (2032) of the second light-emitting unit (103) are 400~410nm and 457.5~465nm, respectively.

4. The light-emitting device according to claim 1, characterized in that, The plurality of first light-emitting units (102) and the plurality of second light-emitting units (103) are arranged in a row on the circuit board (101), and the first light-emitting units (102) and the second light-emitting units (103) are arranged alternately.

5. The light-emitting device according to claim 4, characterized in that, The first light-emitting unit (102) includes two purple light-emitting diode chips (2031), which are connected in series.

6. The light-emitting device according to claim 4, characterized in that, The second light-emitting unit (103) includes a blue light-emitting diode chip (2032) and a purple light-emitting diode chip (2031), which are connected in series.

7. The light-emitting device according to any one of claims 1 to 6, characterized in that, The emission spectrum of the light-emitting device has a first wavelength peak and a second wavelength peak, the first wavelength peak wavelength range is 390~420nm, the second wavelength peak wavelength is 435~475nm, and the ratio of the relative value of the first wavelength peak to the relative value of the second wavelength peak is 4:1 to 6:

1.

8. The light-emitting device according to claim 7, characterized in that, The fluorescent layer (205) is a mixture of phosphor and adhesive. The phosphor includes yellow phosphor and red phosphor. The yellow phosphor is yellow phosphor with an emission wavelength of 545~555nm, and the red phosphor is red phosphor with an emission wavelength of 620~640nm.

9. A backlight module, characterized in that, The backlight module includes a light-emitting device and a current controller (104). The light-emitting device includes: a circuit board (101), a plurality of first light-emitting units (102) and a plurality of second light-emitting units (103), wherein the plurality of first light-emitting units (102) and the plurality of second light-emitting units (103) are all located on the circuit board (101); The first light-emitting unit (102) includes at least one violet light-emitting diode chip (2031). The second light-emitting unit (103) includes at least two light-emitting diode chips (203) and a fluorescent layer (205) covering the at least two light-emitting diode chips (203). The at least two light-emitting diode chips (203) include a blue light-emitting diode chip (2032) and a purple light-emitting diode chip (2031), and the second light-emitting unit (103) emits white light. The current controller (104) is used to control the current of at least one first light-emitting unit (102) according to the current of at least one second light-emitting unit (103), or to control the current of at least one second light-emitting unit (103) according to the current of at least one first light-emitting unit (102).

10. The backlight module according to claim 9, characterized in that, The peak emission wavelength range of the violet light-emitting diode chip (2031) of the first light-emitting unit (102) is 400~410nm.

11. The backlight module according to claim 10, characterized in that, The peak emission wavelength ranges of the violet light-emitting diode chip (2031) and the blue light-emitting diode chip (2032) of the second light-emitting unit (103) are 400~410nm and 457.5~465nm, respectively.

12. The backlight module according to claim 9, characterized in that, The plurality of first light-emitting units (102) and the plurality of second light-emitting units (103) are arranged in a row on the circuit board (101), and the first light-emitting units (102) and the second light-emitting units (103) are arranged alternately.

13. The backlight module according to claim 12, characterized in that, The first light-emitting unit (102) includes two purple light-emitting diode chips (2031), which are connected in series.

14. The backlight module according to claim 12, characterized in that, The second light-emitting unit (103) includes a blue light-emitting diode chip (2032) and a purple light-emitting diode chip (2031), which are connected in series.

15. The backlight module according to any one of claims 9 to 14, characterized in that, The emission spectrum of the light-emitting device has a first wavelength peak and a second wavelength peak, the first wavelength peak wavelength range is 390~420nm, the second wavelength peak wavelength is 435~475nm, and the ratio of the relative value of the first wavelength peak to the relative value of the second wavelength peak is 4:1 to 6:

1.

16. The backlight module according to claim 15, characterized in that, The fluorescent layer (205) is a mixture of phosphor and adhesive. The phosphor includes yellow phosphor and red phosphor. The yellow phosphor is yellow phosphor with an emission wavelength of 545~555nm, and the red phosphor is red phosphor with an emission wavelength of 620~640nm.

17. A display panel, characterized in that, The display panel includes a backlight module (10) and a liquid crystal panel (20); the liquid crystal panel (20) is located on the light-emitting surface of the backlight module (10); The backlight module (10) is the backlight module according to any one of claims 9 to 16.

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