Active matrix driven Mini-LED backlight plate for realizing RGB independent control

Abstract

The utility model relates to the technical field of television or display backlight equipment, and provides an active matrix driven Mini-LED backlight plate capable of achieving RGB independent control, the active matrix driven Mini-LED backlight plate comprises a substrate and a plurality of Mini-LED units arranged on the substrate in an array mode, and each Mini-LED unit comprises an RGB light-emitting unit, an RGB light-emitting unit, an LED light-emitting unit, an LED light-emitting unit and an LED light-emitting unit. Comprising a first blue light chip, a second blue light chip and a third blue light chip which are arranged on the substrate at intervals, and a green light conversion layer is arranged in the light emitting direction of the second blue light chip; a red light conversion layer is arranged in the light emitting direction of the third blue light chip; and the active driving unit is arranged on the substrate, is electrically connected to the RGB light-emitting unit, and is used for independently adjusting the brightness of the first blue light chip, the second blue light chip and the third blue light chip. The three chips of the RGB light-emitting unit are all connected with the driving unit through blue light chips, the brightness changes of the three chips along with changes of temperature, current and voltage are kept consistent, the situation of color shift can be greatly reduced, and the light-emitting stability is higher.

Description

Technical Field

[0001] The present application relates to the technical field of television or display backlight devices, and more specifically, to an active matrix driven Mini-LED backlight panel that realizes independent RGB control. Background Art

[0002] In current display devices, liquid crystal display (LCD) panels do not emit light themselves, so they require a backlight module to provide the necessary light source. The backlight module's function is to provide a sufficiently bright and evenly distributed light source to enable the LCD panel to display images properly. The backlight module's luminous performance directly affects the visual quality and optical quality of the LCD panel.

[0003] Existing liquid crystal display panels basically use LED (Light Emitting Diode) backlight beads as the backlight source. Ordinary LEDs are always in the lit state. When displaying a completely black screen, the light from the backlight source is completely blocked by the control of the LCD panel, but in terms of physical characteristics, these components cannot fully meet this requirement, and there will always be some light leakage. Mini-LED backlight technology uses active driver integrated circuits to independently control the switching and brightness of each LED lamp bead unit, thereby achieving local dimming. It can provide LCD liquid crystals with low power consumption, high brightness, high black and white contrast, high dynamic range and other characteristics. Its picture quality is greatly improved, which can reach or even exceed the display effect of OLED technology, making up for the last shortcoming of LCD display.

[0004] There are two ways to achieve white light in Mini-LED backlight panels. One is that the backlight lamp beads only use blue light chips, and a red and green mixed light conversion layer is set in the light output direction of the blue light chip to obtain blue, green and red light, which are mixed to obtain white light. After the white light passes through the filter, the light of the color corresponding to the filter is transmitted and the color image is displayed on the LCD panel. This type of backlight lamp beads only emits a single white light and cannot independently control the single color of red, green and blue. It has the disadvantages of fixed and unadjustable color, insufficient color gamut, and insufficient energy saving.

[0005] Another approach is to use three different light-emitting chips for backlighting: blue, green, and red. These chips are independently controlled and emit blue, green, and red light, respectively. The resulting mixed colors display the image on the LCD panel. However, the blue and green chips are made of gallium nitride (GaN) semiconductor, while the red chip is made of aluminum indium gallium phosphide (AlInGaP) semiconductor. Because these two materials exhibit different curves affected by temperature, current, and voltage, it's difficult to maintain a consistent white point while simultaneously generating independent currents. This can easily lead to color shift, high production costs, and complex control and compensation systems.

[0006] Therefore, the existing technology still needs to be improved and developed. Utility Model Content

[0007] The purpose of this application is to propose an active matrix driven Mini-LED backlight panel that realizes independent control of RGB, so as to solve the technical problems in the prior art that the LED backlight color gamut is not wide enough, color deviation is easy to occur, and the cost is high.

[0008] To achieve the above objectives, the technical solution adopted in this application is: three-color CSP (Chip Scale Package) chips are separately manufactured on three blue light chips, and an active matrix driver is used to provide a Mini-LED backlight panel that realizes independent control of RGB and maintains stable color and brightness with changes in temperature, current, and voltage. The Mini-LED backlight panel includes a substrate and a plurality of Mini-LED units arranged in an array on the substrate. The Mini-LED units include:

[0009] An RGB light-emitting unit includes a first blue light chip, a second blue light chip, and a third blue light chip spaced apart on the substrate, wherein a green light conversion layer is provided in the light-emitting direction of the second blue light chip; a red light conversion layer is provided in the light-emitting direction of the third blue light chip, and the light-emitting directions of the first blue light chip, the second blue light chip, and the third blue light chip include directly above the chip, around the chip, and a combination thereof;

[0010] An active driving unit is provided on the substrate and electrically connected to the RGB light-emitting unit, and is used to independently adjust the brightness of the first blue light chip, the second blue light chip, and the third blue light chip.

[0011] Furthermore, the green light conversion layer includes a transparent film layer containing green light conversion particles therein, and the red light conversion layer includes a transparent film layer containing red light conversion particles therein.

[0012] Furthermore, the green light conversion particles include any one of green light phosphor particles and green light quantum dot particles or a combination thereof, and the red light conversion particles include any one of red light phosphor particles and red light quantum dot particles or a combination thereof.

[0013] Furthermore, the green light phosphor particles include β-SiAlON narrow peak width phosphor; the green light quantum dot particles include cadmium selenide, indium phosphide, and perovskite; the red light phosphor particles include fluoride KSF and KGF narrow peak width phosphor; the red light quantum dot particles include cadmium selenide, indium phosphide, and perovskite.

[0014] In some embodiments, the active driving unit includes a connection circuit and a driving integrated circuit provided on the substrate, and the connection circuit is electrically connected to the first blue light chip, the second blue light chip, and the third blue light chip through the driving integrated circuit.

[0015] Furthermore, the driving integrated circuit includes a plurality of independent current control channels, and the first blue light chip, the second blue light chip and the third blue light chip are independently connected to at least one of the current control channels.

[0016] In some embodiments, the RGB light-emitting unit further includes a fourth blue light chip, and a green light conversion layer and a red light conversion layer are stacked in the light-emitting direction of the fourth blue light chip so that the fourth blue light chip independently forms white light. The connecting circuit is electrically connected to the fourth blue light chip through the driving integrated circuit for independently adjusting the brightness of the fourth blue light chip, and the fourth blue light chip is independently connected to at least one of the current control channels.

[0017] In some embodiments, the Mini-LED unit further includes an encapsulation layer for encapsulating the RGB light-emitting unit on the substrate, the encapsulation layer including a transparent silicone layer with a light-shielding layer provided therein, the encapsulation layer covering the light-emitting front and side surfaces of the RGB light-emitting unit, the green light conversion layer and the red light conversion layer are both located within the transparent silicone layer, and the side surfaces of the first blue light chip, the second blue light chip, the third blue light chip, and the fourth blue light chip are all covered by the light-shielding layer.

[0018] In some embodiments, a diffusion layer is further provided in the transparent silicone layer, the diffusion layer covers the light-emitting front sides of the first blue light chip, the second blue light chip, and the third blue light chip, and diffusion particles are provided in the diffusion layer.

[0019] In some embodiments, the Mini-LED unit further includes an optical lens disposed above the RGB light-emitting unit, and the optical lens is used to open or close the light-emitting angle of the RGB light-emitting unit to achieve a uniform light mixing effect.

[0020] In some embodiments, the shape of the optical lens includes hemispherical, crater-shaped, and cylindrical, and the material of the lens includes transparent or translucent silicone or resin.

[0021] The active matrix driven Mini-LED backlight panel with independent RGB control provided by this application has at least the following beneficial effects:

[0022] The three chips of the RGB light-emitting unit all use blue light chips to connect the driving unit. The brightness changes of the three chips remain consistent with changes in temperature, current, and voltage, which can greatly reduce the occurrence of color shift and provide higher light-emitting stability.

[0023] The three chips of the RGB light-emitting unit all use blue light chips to connect to the driving unit. Since the three chips are of the same type and their structural materials are the same, when electrically connected to the driving unit, the circuit wiring and driving control methods are the same. In other words, the three chips can use the same circuit wiring and driving control method, which greatly reduces the complexity of circuit control and the difficulty of wiring.

[0024] All backlights use blue light chips, which can reduce costs.

[0025] The active drive unit can independently control the brightness of each light-emitting chip, and the color temperature of each RGB light-emitting unit can be adjusted. The color gamut of the entire backlight is wider, and grayscale stage adjustment can be achieved, which can produce brighter and more saturated colors.

[0026] Through independent control of the active drive unit, the intensity of scattered light between adjacent RGB light-emitting units can be reduced, thereby reducing the halo effect, improving the black-white contrast, achieving local dimming, and saving power. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0028] Figure 1 A schematic diagram of the structure of an RGB light-emitting unit in an active matrix driven Mini-LED backlight panel that implements independent RGB control according to an embodiment of the present application;

[0029] Figure 2 for Figure 1 Schematic diagram of the structure when the RGB light-emitting unit adopts RGBW light-emitting chip;

[0030] Figure 3 for Figure 1 A schematic diagram of the structure when the RGB light-emitting unit is not provided with a light-shielding layer;

[0031] Figure 4 for Figure 2 A schematic structural diagram of an RGBW light-emitting chip in an RGB light-emitting unit in FIG. 1 when a light-shielding layer is provided;

[0032] Figure 5 Another structural diagram of the RGB light-emitting unit provided in an embodiment of the present application;

[0033] Figure 6A schematic diagram of the distribution of Mini-LED units on a substrate provided in an embodiment of the present application;

[0034] Figure 7 for Figure 5 A schematic diagram of the structure of the connection between the first blue light chip and the current control channel;

[0035] Figure 8 This is a schematic diagram comparing the structures of the third blue light chip and the fourth blue light chip provided in the embodiments of the present application.

[0036] Among them, the reference numerals in the figures are:

[0037] 1. Substrate;

[0038] 2. First blue light chip; 21. N-GaN layer; 22. P-GaN layer;

[0039] 3. Second blue light chip; 31. Green light conversion layer; 32. Green light conversion particles;

[0040] 4. Third blue light chip; 41. Red light conversion layer; 42. Red light conversion particles;

[0041] 5. The fourth blue light chip;

[0042] 6. Connect the circuit;

[0043] 7. Driver integrated circuit; 71. Current control channel; 72. Gate electrode layer; 73. Source electrode layer; 74. Drain electrode layer;

[0044] 8. Encapsulation layer; 81. Transparent silicone layer; 82. Light shielding layer; 83. Diffusion layer; 84. Diffusion particles;

[0045] 9. Optical lens. DETAILED DESCRIPTION

[0046] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0047] It should be noted that when a component is referred to as being "fixed on" or "disposed on" another component, it may be located directly or indirectly on the other component. When a component is referred to as being "connected to" another component, it may be directly or indirectly connected to the other component. The directions or positions indicated by the terms "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the directions or positions shown in the accompanying drawings and are only for the convenience of description and cannot be understood as limitations on this technical solution. The terms "first" and "second" are only used for the purpose of convenience of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0048] Traditionally, a light conversion layer is mixed with encapsulant and then stacked on a blue light chip. This creates a white mini LED through light color recombinant processing. The emitted white light passes through a filter, and light corresponding to the filter's color is transmitted, displaying the color image on the LCD panel. However, this backlight emits only a single white light, a fixed, unadjustable color, resulting in a low color gamut. Furthermore, during use, the backlight remains constantly on while the filter and LCD panel are used to adjust brightness, resulting in high costs.

[0049] In addition, there are currently backlight lamp beads composed of R, G, and B three-color chips. The R, G, and B three-color chips can be controlled independently. By independently controlling each light-emitting chip in the R, G, and B three-color chips, the color gamut of the backlight lamp beads can be improved. However, when factors such as temperature, current, and voltage change, because the R, G, and B three-color chips have different structural materials, the characteristic curves of the three chips are different, and color shift will occur. This causes the observed color to not match the expected color, affecting the perception of the display screen color. In addition, because the R, G, and B three-color chips have different structures, each color chip requires a separate wiring method and current and voltage control method, which will lead to a complex drive control system. In addition, the cost of the three color chips is also different. The cost of the red light chip is higher than that of the blue and green light chips, which is also one of the reasons for the cost increase.

[0050] Therefore, the current Mini-LED backlight panels are far from meeting today's society's requirements for lower energy consumption, higher energy efficiency and higher color gamut.

[0051] The following, in conjunction with the accompanying drawings, describes an active matrix driven Mini-LED backlight panel that realizes independent control of RGB in an embodiment of the present application. By combining a blue light chip with a light conversion layer, R, G, and B three-color chips are obtained to reduce costs and color shift. The luminous brightness of the R, G, and B three-color chips is independently controlled by an active drive unit to achieve dynamic dimming.

[0052] See also Figures 1-6 , showing a structural schematic diagram of the active matrix driven Mini-LED backlight panel that realizes independent RGB control of the present application, including a substrate 1 and a plurality of Mini-LED units arranged in an array on the substrate 1.

[0053] See Figures 1-6 The Mini-LED unit includes an RGB light-emitting unit and an active driving unit. The RGB light-emitting unit includes a first blue light chip 2, a second blue light chip 3, and a third blue light chip 4, which are spaced apart on a substrate 1. A green light conversion layer 31 is provided in the light-emitting direction of the second blue light chip 3; a red light conversion layer 41 is provided in the light-emitting direction of the third blue light chip 4. The light-emitting directions of the first blue light chip 2, the second blue light chip 3, and the third blue light chip 4 include those directly above the chip, around the chip, and any combination thereof.

[0054] The active driving unit is provided on the substrate 1 and electrically connected to the RGB light-emitting unit, and is used to independently adjust the brightness of the first blue light chip 2 , the second blue light chip 3 and the third blue light chip 4 .

[0055] First, the chip structure used in the RGB light-emitting unit is different from that used in the prior art, resulting in different wiring methods and production costs.

[0056] Specifically, in this embodiment, the second blue light chip 3, combined with the green light conversion layer 31, forms a blue-green chip capable of emitting blue and green light. The third blue light chip 4, combined with the red light conversion layer 41, forms a red-blue chip capable of emitting blue and red light. Combined with the blue light emitted by the first blue light chip 2, three colors of blue, green, and red light can be obtained. These three colors, when combined, form white light. Unlike the prior art method of using three independent R, G, and B color chips, the three chips of the RGB light-emitting unit all use blue light chips to connect to the driver unit. Because the three chips are of the same type and made of the same structural materials, when electrically connected to the driver unit, the circuit wiring and drive control methods are the same. In other words, the three chips can use the same circuit wiring and drive control methods, which greatly reduces the complexity of circuit control and the difficulty of wiring.

[0057] In addition, the blue light chip, red light chip and green light chip are all semiconductor devices specially designed to emit light of corresponding colors. Structurally, they include n-type semiconductor layers and p-type semiconductor layers.

[0058] Current blue light chips generally use N-type gallium nitride (N-GaN) material as the n-type semiconductor layer, which is used as the electron transfer layer, and P-type gallium nitride (P-GaN) material as the p-type semiconductor layer, which is used as the hole transfer layer. Green light chips are also based on the GaN system, but in order to produce green light, the indium content in the InGaN layer is usually higher than that of blue light chips, which leads to a smaller energy gap width and thus produces a longer wavelength. Red light chips are usually based on aluminum gallium arsenide (AlGaAs) or aluminum gallium indium phosphide (AlGaInP) materials, which have energy gap widths suitable for producing red light. Due to the difference in structure, the production costs of blue light chips, red light chips and green light chips are also different. Generally speaking, the production cost of blue light chips is the lowest, and the production costs of green light chips and red light chips increase successively. The backlight of this embodiment uses blue light chips in its entirety, which can achieve the effect of reducing costs.

[0059] Secondly, the chip materials used in the RGB light-emitting unit are different from those used in the existing technology, resulting in different light decay characteristics.

[0060] For example, taking temperature as an example, each color light-emitting chip generates heat during operation, and this heat directly affects the chip's performance, including light output (brightness) and wavelength stability. When the temperature of the light-emitting chip rises, the high temperature reduces the carrier recombination efficiency within the LED chip, often leading to light decay, meaning a decrease in brightness. This phenomenon is known as "thermal-induced light decay."

[0061] The following are the light decay characteristics of different color light emitting chips related to temperature:

[0062] Blue light chips typically use gallium nitride (GaN) as their primary material. At high temperatures, the carrier recombination efficiency in GaN decreases, leading to reduced light output. Furthermore, high temperatures affect the current injection efficiency of the light-emitting chip, further exacerbating light decay.

[0063] Green light chips are typically based on indium gallium nitride (InGaN) or zinc selenide (ZnSe) materials. The efficiency issue for green light chips is often more complex than for blue and red light because the green wavelength band lies in the so-called "green gap," making efficient green light emission more difficult. Rising temperatures exacerbate this problem, further reducing light efficiency.

[0064] Red light chips typically use aluminum gallium arsenide (AlGaAs) or indium gallium phosphide (InGaP) materials. Red light chips exhibit different light degradation over temperature than blue and green light chips, but they also experience a drop in efficiency. This degradation is more closely related to intrinsic material defects and non-radiative recombination pathways.

[0065] As can be seen, as temperature increases, the light attenuation characteristics of the blue, green, and red chips vary with temperature. If an RGB light-emitting unit uses three color chips—blue, green, and red—then the brightness of the three color chips will change inconsistently as the temperature rises. This will result in one color chip being brighter and the others being dimmer, leading to color shift. In this embodiment, all three color chips use a blue chip as the base, maintaining consistent brightness across the three chips as temperature changes. This significantly reduces color shift and improves light emission stability.

[0066] In addition, in addition to the influence of temperature factors, the light decay characteristics of different color light-emitting chips with different currents and voltages are also different. For example, the instability of the supply voltage will also affect the color and brightness of the light-emitting chip. In other words, the change in voltage will have different effects on the brightness of the three different color chips. When the RGB light-emitting unit works at a high current density for a long time, the material of the light-emitting chip will accelerate aging, resulting in inconsistent changes in the color and brightness of the three color chips. The three color chips of this embodiment all use blue light chips as the base. In other words, the materials and structures of the three color chips are consistent. As the voltage and current change, the light decay effect generated is consistent, which can greatly reduce the color shift and improve the light emission stability.

[0067] For example, three different colors of light-emitting chips (red, green, and blue) are selected and tested using different light sources (photocell, spectral irradiance meter, and photometer). The photocell can generate light in the visible linear region, the spectral irradiance meter can output light of different wavelengths and intensities, and the photometer can test the luminous flux of the light source.

[0068] In the red light chip, the light decay rate of the photocell test results can reach 50%, while the test results of the spectrum radiometer are relatively stable, with a light decay rate of 25%. Under the photometer test, the light decay rate of the LED red chip dropped slightly to 20%.

[0069] Among green light chips, the light decay rate in the photocell test results was the highest, reaching 30%, while the light decay rates in the spectrum radiometer and photometer test results were 15% and 10% respectively.

[0070] In the blue light chip, the maximum light attenuation rate of the photocell, photometer and spectroradiometer test results are 25%, 20% and 15% respectively.

[0071] The experimental results show that under different light sources, the light decay characteristics of different color LED chips are different, and even have a huge impact on the test results of the same LED chip under different light sources.

[0072] The reason for choosing different light sources is that the current, voltage and operating temperature used by different light sources are different. This can indirectly test the light attenuation changes of different color light-emitting chips under different current, voltage and temperature conditions.

[0073] Therefore, the three color chips of the RGB light-emitting unit in this embodiment all use blue light chips. It can be understood that the light attenuation changes caused by multiple identical blue light chips when the temperature, current, and voltage change are very small, which can reduce the light attenuation change deviation caused by temperature, current, and voltage changes, reduce the color shift effect, and greatly improve the light-emitting stability.

[0074] Secondly, the first blue light chip 2, the second blue light chip 3 and the third blue light chip 4 of the RGB light-emitting unit can independently control the brightness through the active driving unit, which can improve the color gamut of the RGB light-emitting unit and realize local dimming.

[0075] The active drive unit can not only control the brightness of each light-emitting chip in an RGB light-emitting unit, but also control the brightness of each RGB light-emitting unit. For example, for the three light-emitting chips in each RGB light-emitting unit, when the brightness of the first blue light chip 2 is adjusted to be the brightest, then the blue light of this RGB light-emitting unit is more, the color temperature is higher, and the overall light emission will be bluer; when the brightness of the third blue light chip 4 is adjusted to be the brightest, then the red light of this RGB light-emitting unit is more, the color temperature is lower, and the overall light emission will be redder. In this way, the color temperature of each RGB light-emitting unit can be adjusted, and the color gamut of the entire backlight will be wider, realizing grayscale stage adjustment, and being able to produce brighter and more saturated colors.

[0076] In addition, when the active driving unit independently controls the brightness, it also includes adjusting the brightness to zero, that is, turning off the light-emitting chip. In the entire backlight, some light-emitting chips can be adjusted to be in a light-emitting state, and another part of the light-emitting chips can be adjusted to be in a light-emitting state, thereby reducing the halo effect of the light-emitting chip, increasing the black and white contrast of the backlight, and saving power.

[0077] It can be understood that halo refers to the soft, diffuse light area formed outside the main light beam. Conventional white light backlight sources remain in a constantly on state when in use, and each RGB light-emitting unit will emit scattered light in all directions. The interaction of the scattered light between adjacent RGB light-emitting units will produce a halo on the display screen. This embodiment independently controls the brightness through active drive units. Only some RGB light-emitting units are lit, and the rest are turned off. This can reduce the intensity of scattered light between adjacent RGB light-emitting units, thereby reducing the halo effect, improving the black-white contrast, achieving local dimming, and saving power.

[0078] Furthermore, the RGB light-emitting unit includes a mini LED chip.

[0079] Furthermore, since both the green chip and the red chip use the blue chip as a substrate, a light conversion layer is provided on the blue chip. In some embodiments, see Figure 1 and Figure 2 The green light chip is composed of the second blue light chip 3 and the green light conversion layer 31 , and the red light chip is composed of the third blue light chip 4 and the red light conversion layer 41 .

[0080] In some embodiments, see Figure 1-Figure 5 The green light conversion layer 31 includes a transparent film layer containing green light conversion particles 32 therein, and the red light conversion layer 41 includes a transparent film layer containing red light conversion particles 42 therein.

[0081] The transparent film layer is a transparent medium, including a structural layer composed of epoxy resin, silicone or other transparent polymers.

[0082] Furthermore, the green light conversion particles 32 include any one of green phosphor particles and green quantum dot particles or a combination thereof, and the red light conversion particles 42 include any one of red phosphor particles and red quantum dot particles or a combination thereof.

[0083] Furthermore, the green light phosphor particles include β-SiAlON narrow peak width phosphor; the green light quantum dot particles include cadmium selenide (CdSe), indium phosphide (InP), and perovskite; the red light phosphor particles include fluoride KSF and KGF narrow peak width phosphor; the red light quantum dot particles include cadmium selenide (CdSe), indium phosphide (InP), and perovskite.

[0084] The manufacturing process of the green light chip and the red light chip is described below by taking the green light conversion particles 32 as green light phosphor particles and the red light conversion particles 42 as red light phosphor particles as an example.

[0085] First, green phosphor particles are mixed with a transparent medium to form a green transparent medium, and red phosphor particles are mixed with a transparent medium to form a red transparent medium. At this time, the green transparent medium and the red transparent medium are both in a fluid state; then, the green transparent medium is coated on the second blue light chip 3 to form a green light conversion layer 31, and the red transparent medium is coated on the third blue light chip 4 to form a red light conversion layer 41. The coating method may include drip coating, spray coating, and screen printing; finally, thermal curing or ultraviolet (UV) curing is used to harden the green light conversion layer 31 and the red light conversion layer 41 so that they adhere to the second blue light chip 3 and the third blue light chip 4.

[0086] Of course, the green phosphor particles and the red phosphor particles can also be directly combined with the second blue light chip 3 and the third blue light chip 4 during the chip packaging process, instead of adding the green light conversion layer 31 and the red light conversion layer 41 separately.

[0087] Furthermore, in order to realize dynamic local dimming of the RGB light-emitting units, an active driving unit is used to control the RGB light-emitting units.

[0088] In some embodiments, the active driving unit includes a connection circuit 6 and a driving integrated circuit 7 (driving IC) provided on the substrate 1 , and the connection circuit 6 is electrically connected to the first blue light chip 2 , the second blue light chip 3 and the third blue light chip 4 through the driving integrated circuit 7 .

[0089] In some embodiments, the active drive unit utilizes a traditional silicon-based semiconductor IC. That is, the driver integrated circuit utilizes a silicon-based semiconductor IC, which is disposed on substrate 1 and is independent of the RGB light-emitting units. The silicon-based semiconductor IC comprises a backlight driver chip (Dimmer) and a backlight control chip (Dcon), which implements low-current drive functionality through an Active Matrix (AM) drive scheme. The backlight driver chip primarily controls the brightness of the LED backlight, while the backlight control chip is responsible for the control logic of the entire backlight system. The Dcon chip receives input from a user interface or environmental sensor and then sends appropriate control signals to the Dimmer chip to adjust the backlight brightness.

[0090] Furthermore, the backlight driver chip is packaged using any one of DFN (Distributed Frame Network / Dual Flat No-Lead), COG (Chip-On-Glass), ISP (In-Screen Panel), and flip chip, and the package size ranges from 1*1mm to 3*3mm.

[0091] In some embodiments, the driver integrated circuit 7 includes a plurality of independent current control channels 71 , and the first blue light chip 2 , the second blue light chip 3 , and the third blue light chip 4 are independently connected to at least one current control channel 71 .

[0092] In some embodiments, the active driving unit can also use the connection circuit 6 and the thin film transistor to realize the backlight control, see Figure 1-Figure 5 and Figure 7 The active driving unit includes a connecting circuit 6 and a thin film transistor provided on the substrate 1 . The connecting circuit 6 is electrically connected to the first blue light chip 2 , the second blue light chip 3 and the third blue light chip 4 through the thin film transistor.

[0093] Among them, the active driving unit is an active matrix (AM) architecture combined with a thin film transistor (TFT) to achieve precise control of each blue light chip in each Mini-LED unit. The blue light chip is used to emit light, and the TFT is used to control the current to adjust the luminous brightness of each blue light chip (the first blue light chip 2, the second blue light chip 3 and the third blue light chip 4).

[0094] By finely controlling the brightness of each blue light chip through the active drive unit, energy consumption can be managed more effectively and a faster refresh rate can be provided, which is especially important for dynamic pictures and picture quality. It provides precise brightness control and high-efficiency performance to achieve high-quality display effects.

[0095] In some embodiments, the thin film transistor includes a plurality of independent current control channels 71 , and the first blue light chip 2 , the second blue light chip 3 , and the third blue light chip 4 are independently connected to at least one current control channel 71 .

[0096] The thin film transistor of this embodiment is a multi-channel thin film transistor (Multi-channel TFT), which refers to a design including two or more current control channels 71 in a single TFT structure.

[0097] For example, the WH5097D chip is a 4-channel mini LED driver chip that supports local dimming and can be used for local dimming in active matrix drives. The GALT61120 chip can independently drive 12 LEDs or LED strings, and can programmatically control sub-string combinations to achieve different functional module applications.

[0098] Taking a 4-channel mini LED driver chip as an example, it includes a first current control channel, a second current control channel, a third current control channel, and a fourth current control channel. The first current control channel is connected to the first blue light chip 2, the second current control channel is connected to the second blue light chip 3, and the third current control channel is connected to the third blue light chip 4. Each blue light chip in the RGB light-emitting unit is independently controlled by a different current control channel 71. The fourth current control channel is connected to another blue light chip in another RGB light-emitting unit, and so on. As a result, each blue light chip in the Mini-LED unit is connected to a current control channel 71 for independent control.

[0099] In some embodiments, see Figures 1-4The active driving unit is independently arranged on the substrate, and each current control channel 71 in the thin film transistor is electrically connected to the first blue light chip 2, the second blue light chip 3, the third blue light chip 4 and the fourth blue light chip 5 through the connecting circuit 6.

[0100] Of course, see Figure 5 , each thin film transistor and connecting circuit 6 in the active driving unit can also be correspondingly arranged below the first blue light chip 2, the second blue light chip 3, the third blue light chip 4 and the fourth blue light chip 5, that is, each thin film transistor and connecting circuit 6 in the active driving unit is located between the blue light chip and the substrate 1.

[0101] Furthermore, thin-film transistors (TFTs) and blue-light chips (typically based on gallium nitride, GaN) have distinct structural differences, but they can be used together.

[0102] Specifically, the basic structure of each current control channel 71 in a thin film transistor (TFT) includes:

[0103] The gate electrode controls the TFT's on / off state. The source electrode serves as the input for current flow. The drain electrode serves as the output for current flow. The active layer, typically an oxide semiconductor, amorphous silicon, or polycrystalline silicon, conducts electrons. The insulating layer isolates the gate electrode from the other electrodes.

[0104] The main structure of the Blu-ray chip includes:

[0105] The N-type gallium nitride (N-GaN) layer provides electrons. The P-type gallium nitride (P-GaN) layer provides holes. The quantum well, typically an indium gallium nitride (InGaN) layer, is where electrons and holes recombine to produce light. Ohmic contacts serve as electrodes for the N-type and P-type layers.

[0106] In some embodiments, the first blue light chip 2, the second blue light chip 3, the third blue light chip 4 and the fourth blue light chip 5 all include an N-GaN layer 21 and a P-GaN layer 22, and the current control channel 71 includes a gate electrode layer 72, a source electrode layer 73 and a drain electrode layer 74; the source electrode layer 73 is electrically connected to the N-GaN layer 21, the drain electrode layer 74 is electrically connected to the P-GaN layer 22, and the gate electrode layer 72 is electrically connected to the connection circuit 6.

[0107] Each thin-film transistor controls one or more LED pixels, or in other words, each current control channel 71 controls a blue light chip. When the current control channel 71 receives a turn-on signal, the voltage change on the gate electrode forms a conductive channel between the source electrode and the drain electrode, allowing current to flow through the N-GaN layer 21 and the P-GaN layer 22 of the blue light chip. The current excites the electrons and holes in the quantum well to recombine, releasing photons, that is, the blue light chip emits light. The gate electrode of the current control channel 71 is used to receive the control signal of the connection circuit 6, and controls the current between the source and the drain according to the strength of the signal, thereby adjusting the brightness of the blue light chip.

[0108] Furthermore, multi-channel thin-film transistor (TFT) structural designs include stacked and parallel structures. The stacked structure involves vertically stacking multiple channel layers, each separated by an insulating layer. This saves space. The parallel structure involves arranging multiple channel layers side by side, each with its own source and drain contacts. This design is easier to manufacture.

[0109] Furthermore, the multi-channel thin film transistor is formed into the above structure through a multi-step deposition, photolithography and etching process, or a combination of atomic layer deposition ALD and chemical vapor deposition CVD.

[0110] Furthermore, RGB LEDs are composed of three independent sub-pixels (blue light chips), each corresponding to the three basic colors of red, green, and blue through a light conversion layer. By adjusting the intensity of these three colors, RGB LEDs can combine to produce almost all colors in the visible spectrum, including white. However, this white is usually a mixture of red, green, and blue in specific proportions, and may not achieve a very pure or specific white (such as cool white or warm white). The brightness of the mixed white is often lower than the brightness of each single color.

[0111] In some embodiments, see Figure 2 、 Figure 4 and Figure 5 The RGB light-emitting unit also includes a fourth blue light chip 5. A green light conversion layer 31 and a red light conversion layer 41 are stacked in the light-emitting direction of the fourth blue light chip 5, so that the fourth blue light chip 5 independently generates white light. The connecting circuit 6 is electrically connected to the fourth blue light chip 5 through the driving integrated circuit 7, and is used to independently adjust the brightness of the fourth blue light chip 5. The fourth blue light chip 5 is independently connected to at least one current control channel 71.

[0112] In this way, a white sub-pixel (the fourth blue light chip 5) is added to the RGB LED, and this additional white sub-pixel can be controlled independently, providing a more direct way to generate white light without even mixing red, green, and blue.

[0113] By setting the white sub-pixel formed by the fourth blue light chip 5, the RGBW LED can achieve higher brightness when displaying white or near-white tones. When displaying white or near-white colors, the RGBW LED can turn off or reduce the power of the red, green, and blue sub-pixels (the other three blue light chips) and only use the white sub-pixel (the fourth blue light chip 5), thereby saving power and maintaining low energy consumption.

[0114] Further, see Figure 1-Figure 5 The Mini-LED unit also includes an encapsulation layer 8 for encapsulating the RGB light-emitting unit on the substrate 1. The encapsulation layer 8 includes a transparent silicone layer 81 with a light-shielding layer 82 inside. The encapsulation layer 8 covers the light-emitting front and side surfaces of the RGB light-emitting unit. The green light conversion layer 31 and the red light conversion layer 41 are both located in the transparent silicone layer 81. The side surfaces of the first blue light chip 2, the second blue light chip 3, the third blue light chip 4, and the fourth blue light chip 5 are all covered by the light-shielding layer 82.

[0115] In some embodiments, encapsulation layer 8 encapsulates the RGB light-emitting units on substrate 1 using CSP (Chip Scale Package) packaging technology, i.e., chip-scale packaging. This packaging approach allows the RGB light-emitting units to be packaged to a size as close to the die as possible. Chip-scale packaging allows the packaged chip area to approach that of the die itself, significantly reducing the size of the package. This reduces overall costs during mass production due to the reduction in packaging materials and process steps.

[0116] Due to the small size of the CSP package, the signal transmission path is shorter, reducing signal delay and electromagnetic interference, improving signal integrity and system performance. Its low thermal resistance helps improve heat dissipation efficiency, reduce operating temperatures, and extend device life. This allows for the integration of more functions within a limited space, such as multi-chip modules, increasing design flexibility. It can be more easily integrated into high-density circuit board layouts, facilitating the design of complex electronic systems.

[0117] In some embodiments, see Figure 2 and Figure 3 The encapsulation layer 8 includes a transparent silicone layer 81 with a light-shielding layer 82 inside. The transparent silicone layer 81 covers the light-emitting front and side surfaces of the RGB light-emitting unit. The side surfaces of the first blue light chip 2, the second blue light chip 3, the third blue light chip 4 and the fourth blue light chip 5 are all covered by the light-shielding layer 82.

[0118] After the packaging is completed, the light emitted from the side of the first blue light chip 2, the second blue light chip 3, the third blue light chip 4 and the fourth blue light chip 5 will be reflected by the light-shielding layer 82, so that the light of the first blue light chip 2, the second blue light chip 3 and the third blue light chip 4 is emitted more from the light-emitting front, avoiding the mutual influence of the light of adjacent blue light chips, thereby achieving the effect of reducing the halo effect.

[0119] Furthermore, the encapsulation layer 8 further includes an epoxy resin layer.

[0120] Further, see Figures 1-4 A diffusion layer 83 is further provided in the transparent silicone layer 81 . The diffusion layer 83 covers the light-emitting front surfaces of the first blue light chip 2 , the second blue light chip 3 and the third blue light chip 4 . Diffusion particles 84 are provided in the diffusion layer 83 .

[0121] The diffusion particles 84 in the diffusion layer 83 are used to mix the light from the red, green and blue LEDs to produce a smooth transition of colors, and the color representation of the RGB light-emitting unit is more accurate.

[0122] The diffusion layer 83 is a material layer made of a transparent polymer, including a polycarbonate layer, an acrylic layer or a polymethyl methacrylate layer. These diffusion layers 83 are doped with tiny scattering particles, such as silicon dioxide particles, titanium dioxide particles or other microbeads, to achieve a light scattering effect.

[0123] In some embodiments, see Figure 1 and Figure 2 The Mini-LED unit also includes an optical lens 9 arranged above the RGB light-emitting unit. The optical lens 9 is used to open or close the light-emitting angle of the RGB light-emitting unit to achieve a uniform mixed light effect.

[0124] Furthermore, the shape of the optical lens 9 includes hemispherical, crater-shaped, and cylindrical, and the material of the lens includes transparent or translucent silicone or resin.

[0125] For example, see Figure 1 and Figure 2 The optical lens 9 is set to a crater shape with a concave center. When the light emitted by the RGB light-emitting unit passes through the optical lens 9, the concave area in the center of the optical lens 9 can diffuse the light, open the luminous angle of the central area, and make the mixed light effect more uniform.

[0126] In some embodiments, see Figure 8The thickness of the green light conversion layer 31 on the second blue light chip 3 is greater than the thickness of the red-green conversion layer on the fourth blue light chip 5. The thickness of the red light conversion layer 41 on the third blue light chip 4 is greater than the thickness of the red-green conversion layer on the fourth blue light chip 5. The green light conversion particles of the second blue light chip 3 and the red light conversion particles of the third blue light chip 4 are both solid particles and are distributed within the encapsulation layer 8. Similarly, the red and green light conversion particles on the fourth blue light chip 5 are also distributed within the encapsulation layer 8 in the form of solid particles.

[0127] The red and green light conversion layers 41 and 31 are thicker. When the blue light emitted by the blue chip passes through these layers, it can more easily interact with the green and red light conversion particles within them, more fully stimulating the production of red and green light, resulting in more vivid and saturated colors. The red and green conversion layers, used to produce white light in conjunction with blue light, do not require vibrant or highly saturated colors. For cost savings, the red and green conversion layers are thinner.

[0128] Furthermore, the thickness of the first blue light chip 2, the second blue light chip 3, the third blue light chip 4 and the fourth blue light chip 5 are all 0.05-0.25 mm, the thickness of the package 8 on the second blue light chip 3 and the third blue light chip 4 is 0.3-0.8 mm, and the thickness of the package 8 on the fourth blue light chip 5 is 0.3-0.8 mm. When the diffusion layer 83 is set, the thickness of the diffusion layer 83 is 0.05-0.25 mm.

[0129] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. An active matrix driven Mini-LED backlight panel that realizes independent control of RGB, characterized by: The device comprises a substrate and a plurality of Mini-LED units arranged in an array on the substrate, wherein the Mini-LED units include: An RGB light-emitting unit includes a first blue light chip, a second blue light chip, and a third blue light chip spaced apart on the substrate, wherein a green light conversion layer is provided in the light-emitting direction of the second blue light chip; a red light conversion layer is provided in the light-emitting direction of the third blue light chip, and the light-emitting directions of the first blue light chip, the second blue light chip, and the third blue light chip include directly above the chip, around the chip, and a combination thereof; An active driving unit is provided on the substrate and electrically connected to the RGB light-emitting unit, and is used to independently adjust the brightness of the first blue light chip, the second blue light chip, and the third blue light chip.

2. The active matrix driven Mini-LED backlight panel for realizing independent RGB control according to claim 1, characterized in that: The green light conversion layer includes a transparent film layer with green light conversion particles arranged therein, and the red light conversion layer includes a transparent film layer with red light conversion particles arranged therein.

3. The active matrix driven Mini-LED backlight panel for realizing independent RGB control according to claim 2, characterized in that: The green light conversion particles include any one of green light phosphor particles and green light quantum dot particles or a combination thereof, and the red light conversion particles include any one of red light phosphor particles and red light quantum dot particles or a combination thereof.

4. The active matrix driven Mini-LED backlight panel for realizing independent RGB control according to claim 3, characterized in that: The green light phosphor particles include β-SiAlON narrow peak width phosphor; the green light quantum dot particles include cadmium selenide, indium phosphide or perovskite; the red light phosphor particles include fluoride KSF, KGF narrow peak width phosphor; the red light quantum dot particles include cadmium selenide, indium phosphide or perovskite.

5. The active matrix driven Mini-LED backlight panel for realizing independent RGB control according to claim 1, characterized in that: The active driving unit includes a connection circuit and a driving integrated circuit provided on the substrate, and the connection circuit is electrically connected to the first blue light chip, the second blue light chip, and the third blue light chip through the driving integrated circuit.

6. The active matrix driven Mini-LED backlight panel for realizing independent RGB control according to claim 5, characterized in that: The driving integrated circuit includes a plurality of independent current control channels, and the first blue light chip, the second blue light chip and the third blue light chip are independently connected to at least one of the current control channels.

7. The active matrix driven Mini-LED backlight panel for realizing independent RGB control according to claim 6, characterized in that: The RGB light-emitting unit also includes a fourth blue light chip, and a green light conversion layer and a red light conversion layer are stacked in the light-emitting direction of the fourth blue light chip, so that the fourth blue light chip independently generates white light. The connecting circuit is electrically connected to the fourth blue light chip through the driving integrated circuit, and is used to independently adjust the brightness of the fourth blue light chip. The fourth blue light chip is independently connected to at least one of the current control channels.

8. The active matrix driven Mini-LED backlight panel for realizing independent RGB control according to claim 7, characterized in that: The Mini-LED unit also includes an encapsulation layer for encapsulating the RGB light-emitting unit on the substrate. The encapsulation layer includes a transparent silicone layer with a light-shielding layer provided therein. The encapsulation layer covers the light-emitting front and side surfaces of the RGB light-emitting unit. The green light conversion layer and the red light conversion layer are both located within the transparent silicone layer. The side surfaces of the first blue light chip, the second blue light chip, the third blue light chip, and the fourth blue light chip are all covered by the light-shielding layer.

9. The active matrix driven Mini-LED backlight panel for realizing independent RGB control according to claim 8, characterized in that: A diffusion layer is further provided in the transparent silicone layer. The diffusion layer covers the light-emitting fronts of the first blue light chip, the second blue light chip, the third blue light chip and the fourth blue light chip. Diffusion particles are provided in the diffusion layer.

10. The active matrix driven Mini-LED backlight panel for realizing independent RGB control according to claim 1, characterized in that: The Mini-LED unit further includes an optical lens disposed above the RGB light-emitting unit, and the optical lens is used to open or close the light-emitting angle of the RGB light-emitting unit to achieve a uniform light mixing effect.

11. The active matrix driven Mini-LED backlight panel for realizing independent RGB control according to claim 10, characterized in that: The shape of the optical lens includes hemispherical, crater-shaped or cylindrical, and the material of the lens includes transparent or translucent silicone or resin.

Images