Display panel and display device

Abstract

Disclosed in the present application are a display panel and a display device. The display panel comprises: an array substrate, wherein a plurality of pixel driving circuits are provided on the array substrate; and a plurality of light-emitting units, which are arranged on the array substrate in an array, wherein each light-emitting unit comprises a plurality of light-emitting chips, the plurality of light-emitting chips comprising a first light-emitting chip, a second light-emitting chip and a third light-emitting chip, and the number of light-emitting chips contained in any light-emitting unit is greater than the number of color types of the light-emitting chips.

Description

Display panel and display device Technical Field

[0001] The present application relates to the field of display technology, and in particular to a display panel and a display device. Background Art

[0002] MLED (Mini / Micro LED) direct display technology has recently garnered increasing attention. Its numerous advantages, including high brightness, high contrast, high resolution, excellent reliability, and the ability to create flexible displays, have earned it widespread recognition as the next generation of display technology. However, MLED still faces significant challenges in design, processing, driving, and optics. The unstable efficiency of current inorganic microLEDs requires the TFTs in their driver circuits to operate in the saturation region, resulting in significant power loss in the direct display substrate circuitry and, consequently, in the overall system. SUMMARY OF THE INVENTION

[0003] The embodiments of the present application provide a display panel and a display device. When multiple light-emitting chips are connected, the number of components connected in the pixel driving circuit increases, the current decreases, the power consumption of the light-emitting chip part accounts for an increased proportion of the panel power consumption, and the overall power consumption of the panel is reduced.

[0004] In a first aspect, an embodiment of the present application provides a display panel, comprising:

[0005] an array substrate, on which a plurality of pixel driving circuits are provided;

[0006] a plurality of light-emitting units, wherein an array of the plurality of light-emitting units is disposed on the array substrate, the light-emitting units comprising a plurality of light-emitting chips, the plurality of light-emitting chips comprising a first light-emitting chip, a second light-emitting chip, and a third light-emitting chip, wherein the first light-emitting chip, the second light-emitting chip, and the third light-emitting chip have different colors; the number of light-emitting chips included in any one of the light-emitting units is greater than the number of colors of the light-emitting chips; the light-emitting chips of the same color in the light-emitting units are connected in series, and the light-emitting chips of the same color in the light-emitting units are electrically connected to a pixel driving circuit;

[0007] The first light-emitting chip provides blue light, the second light-emitting chip provides red light, and the third light-emitting chip provides green light; the light-emitting unit includes one first light-emitting chip, at least one second light-emitting chip, and at least one third light-emitting chip;

[0008] The first light-emitting chip, the second light-emitting chip and the third light-emitting chip are alternately arranged in the light-emitting unit.

[0009] In a first aspect, an embodiment of the present application provides a display panel, comprising:

[0010] an array substrate, on which a plurality of pixel driving circuits are provided;

[0011] A plurality of light-emitting units, wherein the plurality of light-emitting units are arrayed on the array substrate, each of the light-emitting units includes a plurality of light-emitting chips, the plurality of light-emitting chips include a first light-emitting chip, a second light-emitting chip, and a third light-emitting chip, and the colors of the first light-emitting chip, the second light-emitting chip, and the third light-emitting chip are different from each other; the number of light-emitting chips included in any one of the light-emitting units is greater than the number of colors of the light-emitting chips, the light-emitting chips of the same color in the light-emitting units are connected in series, and the light-emitting chips of the same color in the light-emitting units are electrically connected to a pixel driving circuit.

[0012] In a third aspect, the present application provides a display device, comprising a display panel as described in any one of the above. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The following detailed description of the specific embodiments of the present application in conjunction with the accompanying drawings will make the technical solutions and other beneficial effects of the present application apparent.

[0014] FIG1 is a schematic structural diagram of a display panel according to an embodiment of the present application;

[0015] FIG2 is a schematic diagram showing the connection of light-emitting chips in a display panel according to another embodiment of the present application;

[0016] FIG3 is a schematic diagram showing the connection of components of a display panel in an embodiment of the present application;

[0017] FIG4 is a schematic diagram of the current efficiency of a red light-emitting chip in one embodiment of the present application;

[0018] FIG5 is a schematic diagram of a 3T1C pixel driving circuit in an embodiment of the present application;

[0019] FIG6 is a driving timing diagram of the 3T1C pixel driving circuit shown in FIG4 of the present application;

[0020] FIG7 is a schematic diagram of an 8T1C pixel driving circuit according to an embodiment of the present application;

[0021] FIG8 is a driving timing diagram of the 8T1C pixel driving circuit shown in FIG6 of the present application;

[0022] FIG9 is a schematic diagram of a 7T2C pixel driving circuit according to an embodiment of the present application;

[0023] FIG10 is a driving timing diagram of the 7T2C pixel driving circuit T2 detection shown in FIG7 of the present application;

[0024] FIG11 is a driving timing diagram of the 7T2C pixel driving circuit T4 detected in FIG7 of the present application;

[0025] FIG12 is a schematic diagram of the color coordinates of a green light-emitting chip in another embodiment of the present application;

[0026] FIG13 is a schematic diagram of the manufacturing process flow of a direct display sample in one embodiment of the present application.

[0027] Figure Number:

[0028] 1. Array substrate; 2. Light-emitting unit; 21. First light-emitting chip; 22. Second light-emitting chip; 23. Third light-emitting chip. Modes for Carrying Out the Invention

[0029] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0030] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present application, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0031] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or mutual communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0032] In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0033] The disclosure below provides many different embodiments or examples for realizing different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present application. In addition, the present application may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplicity and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those of ordinary skill in the art will appreciate the application of other processes and / or the use of other materials.

[0034] 1 and 2 , an embodiment of the present application provides a display panel, which includes an array substrate 1 and a plurality of light-emitting units 2 arranged in an array on the array substrate 1. The array substrate 1 is provided with a plurality of pixel driving circuits (not shown in the figures).

[0035] Each light-emitting unit 2 includes multiple light-emitting chips, including a first light-emitting chip 21, a second light-emitting chip 22, and a third light-emitting chip 23. The first light-emitting chip 21, the second light-emitting chip 22, and the third light-emitting chip 23 have different colors. For example, the first light-emitting chip 21, the second light-emitting chip 22, and the third light-emitting chip 23 are blue, red, and green, respectively. The different color light-emitting chips of a light-emitting unit 2 cooperate to output pixel images of different colors. In other words, a light-emitting unit 2 is the smallest unit of a light-emitting chip combination. Based on different display panel light-emitting principles, a light-emitting unit 2 may also include a fourth light-emitting chip, a white light-emitting chip, etc., which is not specifically limited in this embodiment.

[0036] The number of light-emitting chips included in the light-emitting unit 2 is greater than the number of colors of the light-emitting chips, that is, the number of light-emitting chips of at least one color in the light-emitting unit 2 is two or more. For example, if the light-emitting unit 2 includes light-emitting chips of three colors, namely, a first light-emitting chip 21, a second light-emitting chip 22, and a third light-emitting chip 23, then the total number of light-emitting chips included in the light-emitting unit 2 is at least four. The first light-emitting chip 21, the second light-emitting chip 22, and the third light-emitting chip 23 are blue, red, and green, respectively. Therefore, there is one blue light-emitting chip, two red light-emitting chips, and one green light-emitting chip. The specific number of the three light-emitting chips, namely, the first light-emitting chip 21, the second light-emitting chip 22, and the third light-emitting chip 23, is not specifically limited in this embodiment.

[0037] The pixel driver circuit on the array substrate 1 is used to drive the light-emitting chips in the light-emitting units 2 to emit light. Because light-emitting chips of different colors may have different luminous intensities, each light-emitting chip of a different color in the light-emitting unit 2 is electrically connected to a pixel driver circuit. That is, the number of pixel driver circuits connected to a light-emitting unit 2 is the same as the number of colors of the light-emitting chips contained in the light-emitting unit 2. For example, if a light-emitting unit 2 includes light-emitting chips of three colors: a first light-emitting chip 21, a second light-emitting chip 22, and a third light-emitting chip 23, the light-emitting unit 2 is electrically connected to three pixel driver circuits: one for each of the first light-emitting chip 21, the second light-emitting chip 22, and the third light-emitting chip 23. Furthermore, light-emitting chips of the same color in the light-emitting unit 2 are connected in series and, after being connected in series, are electrically connected to the same pixel driver circuit.

[0038] In the pixel driving circuit provided on the array substrate 1 in this embodiment, compared with connecting only one light-emitting chip, when multiple light-emitting chips are connected, the number of components connected in the pixel driving circuit increases and the current decreases. However, the power consumption of the light-emitting chip portion accounts for an increased proportion of the panel power consumption, thereby reducing the proportion of the power consumption of the TFT (Thin Film Transistor) in the pixel driving circuit in the panel power consumption, thereby reducing the overall power consumption of the panel.

[0039] In one embodiment, the light-emitting unit 2 is connected between a first voltage terminal VDD and a second voltage terminal VSS. Therefore, a portion of the voltage difference between the first voltage terminal VDD and the second voltage terminal VSS is divided across the light-emitting chip, and another portion is divided across the pixel driver circuit. However, when the light-emitting chip is not emitting light, the entire voltage difference between the first voltage terminal VDD and the second voltage terminal VSS is applied across the pixel driver circuit. Therefore, due to the limitations of the components in the pixel driver circuit, the voltage difference between the first voltage terminal VDD and the second voltage terminal VSS is limited within a certain range. Therefore, the number of light-emitting chips cannot be increased indefinitely. The maximum number of any light-emitting chip in the light-emitting unit 2 is positively correlated with the voltage difference between the first voltage terminal VDD and the second voltage terminal VSS. Furthermore, the maximum number of any light-emitting chip in the light-emitting unit 2 is the integer of the ratio of the voltage difference between the first voltage terminal VDD and the second voltage terminal VSS to the voltage difference of the light-emitting chip. For example, if the voltage difference between the first voltage terminal VDD and the second voltage terminal VSS is 11V and the voltage difference of the light-emitting chip is 2V, the maximum number of light-emitting chips is 5.

[0040] In one embodiment, because the voltage difference across a blue light-emitting chip (voltage difference of 2.5V) is greater than that across a red light-emitting chip (voltage difference of 1.8V) and a green light-emitting chip (voltage difference of 1.2V) at the same current, when multiple blue light-emitting chips are connected in series in a pixel driving circuit, the voltage divided across the blue light-emitting chips is too large. Under the assumption that the voltage difference between the first voltage terminal VDD and the second voltage terminal VSS is constant, the voltage difference across the driving TFT in the pixel driving circuit is too small, potentially causing the pixel driving circuit to fail to drive. Therefore, when the first light-emitting chip 21 is a blue light-emitting chip, the light-emitting unit 2 includes only one first light-emitting chip 21. When the second light-emitting chip 22 is a red light-emitting chip, the number of second light-emitting chips 22 is 2-6, and when the third light-emitting chip 23 is a green light-emitting chip, the number of third light-emitting chips 23 is 2-4.

[0041] In one embodiment, the light-emitting unit 2 is the smallest unit of the light-emitting chip combination defined for ease of description. All light-emitting chips in the display panel can be individually disposed on the array substrate 1, or the light-emitting chips can be packaged to facilitate transfer and installation. That is, the light-emitting chips of at least one light-emitting unit 2 are packaged to obtain an LED package module, and the light-emitting chips within an LED package module are installed as a whole. The light-emitting unit 2 also includes a substrate (not shown) and an encapsulation layer (not shown). The first light-emitting chip 21, the second light-emitting chip 22, and the third light-emitting chip 23 are bonded to the substrate. The encapsulation layer covers the first light-emitting chip, the second light-emitting chip, and the third light-emitting chip. That is, the light-emitting unit 2 is packaged as a whole to facilitate mass transfer. It should be noted that the number of light-emitting chips contained in a light-emitting unit 2 is not specifically limited in this embodiment.

[0042] MicroLED chips (MIPs) are packaged for SMD display. For example, R2GB-packaged MIPs contain three RGB chips. Each color microchip on the packaged MIP is controlled by a separate electrode, while the single-color chip is controlled by a separate circuit (each circuit contains 1-20 transistors). This means each MIP has three circuits controlling the RGB chips. As shown in Figure 3, the display panel is connected to the display control system via a connector (connector, FPC, COF, etc.). The peripheral drive circuit system controls the IC, which edits, controls, and transmits signals to the display panel.

[0043] In one embodiment, each light-emitting chip in the LED package module can be individually wired and connected. However, to facilitate layout and reduce wiring, the light-emitting chips in the LED package module share a common cathode or a common anode. As shown in Figure 2, the three-color chip uses a common cathode, while the anode at the other end is designed separately.

[0044] In one embodiment, since there are two or more light-emitting chips of at least one color in a light-emitting unit 2, in order to make the color displayed in a light-emitting unit 2 uniform, the first light-emitting chip 21, the second light-emitting chip 22 and the third light-emitting chip 23 in the light-emitting unit 2 are arranged alternately, that is, any two adjacent light-emitting chips are not the same color as much as possible, to avoid the same color block being larger when two adjacent light-emitting chips are the same color, which affects the display effect. n G m In the form of B (n: 2-6; m: 2-4), for example, a light-emitting unit 2 contains one blue light-emitting chip, two red light-emitting chips, and one green light-emitting chip. As shown in Figure 1, the four light-emitting chips in the light-emitting unit 2 are arranged in a rectangle, with two light-emitting chips of the same color located at the diagonal of the rectangle. Taking R2GB as an example, the MIP packaged lamp bead contains one blue micro chip, one green micro chip, and two red micro chips. The red chips are arranged alternately with the blue and green chips. The RGB chips are connected in parallel, and the two red chips are connected in series.

[0045] In one embodiment, the pixel driving circuit includes a driving module, a switching module, and a charge storage module. The driving module and the light-emitting chip of the same color in the light-emitting unit 2 are connected in series between a first voltage terminal (VDD) and a second voltage terminal (VSS), and the driving module and the charge storage module are electrically connected. The first end of the switch module is connected to a scan signal, the second end of the switch module is connected to a data signal, and the third end of the switch module is connected to the driving module and the charge storage module. The scan signal controls the switch module to turn on and write the data signal into the charge storage module, so that the driving module drives the connected light-emitting chip to emit light.

[0046] The driver module includes a driver TFT, driven using an active matrix TFT method. The TFT transistors can be LTPS, LTPO, or IGZO. The switch module includes at least one switching TFT, and the charge storage module includes at least one storage capacitor. Since TFT transistors require arrayed film formation, process fluctuations can make it difficult to achieve uniform electrical characteristics for each TFT. Therefore, if the TFT operates in the linear region, fluctuations in its electrical parameters will significantly impact the brightness and uniformity of the LED light. Therefore, it is recommended that the TFT operate in the electrical saturation region. In the saturation region, the current variation with voltage is smaller, which facilitates uniform LED light emission. Under a specific current and a certain pitch design, the panel power consumption in the saturation region is determined solely by the voltage across the first and second voltage terminals. Since the voltage across the TFT in the saturation region is relatively constant, the panel power consumption in the saturation region is also relatively stable. Increasing the proportion of LED power consumption in the panel power consumption can help improve the photoelectric conversion efficiency of microLED direct displays.

[0047] Since TFT transistors need to be produced through array film formation, fluctuations in the process make it difficult to achieve the same electrical characteristics for each TFT. Therefore, if the TFT operates in the linear region, the fluctuation of its electrical parameters will have a significant impact on the brightness and uniformity of the LED light. Therefore, it is recommended that the TFT operate in the electrical saturation region. The current of the TFT in the saturation region varies less with voltage, which is conducive to achieving uniform light emission of the LED. Under a specific current and a certain pitch design, the power consumption of the panel in the saturation region is determined only by the voltage between the first voltage terminal Vdd and the second voltage terminal Vss. Since the voltage across the TFT in the saturation region is also relatively constant, the power consumption of the panel in the saturation region is also relatively certain. Increasing the proportion of LED power consumption in the panel power consumption is conducive to improving the photoelectric conversion efficiency of microLED direct display. The RnGmB setting can be used to increase the proportion of LED power consumption. For example, when two R chips are connected in series, if the same brightness needs to be maintained, the driving current of the R chip can be reduced by half (without considering the luminous efficiency), which significantly reduces the panel power consumption and increases the proportion of RGB power consumption. If the R current is kept unchanged, the panel power consumption remains unchanged, but the power consumption of the R chip is doubled, the panel brightness is improved, and the proportion of RGB chip power consumption is increased.

[0048] The simplest pixel driving circuit applicable to this embodiment is a 2T1C circuit, in which the gate of the switching TFT is connected to a scan signal, one end of the source and drain of the switching TFT is connected to a data signal, the other end of the source and drain of the switching TFT is connected to the gate of the driving TFT and one end of the storage capacitor, one end of the source and drain of the driving TFT is connected to a first voltage terminal, the other end of the source and drain of the driving TFT is connected to the other end of the storage capacitor and the anode of the light-emitting chip, and the cathode of the light-emitting chip is connected to a second voltage terminal. Therefore, compared to connecting only one light-emitting chip, when multiple light-emitting chips are connected, the current flowing through the driving TFT and the light-emitting chip decreases. Under the premise that the voltage difference between the first voltage terminal and the second voltage terminal remains unchanged, the overall power consumption of the display panel is reduced, the voltage divided across the driving TFT is reduced, and the voltage divided across the light-emitting chip is increased, and the power consumption of the light-emitting chip portion of the overall power consumption of the display panel increases.

[0049] The more mature process for red microLED chips doesn't utilize the InPAs light-emitting structure, resulting in poor thermal stability. This leads to noticeable brightness decay and color shift over extended periods of use. Due to the characteristics of red LEDs, their current efficiency rolls off at high temperatures, as shown in Figure 4, significantly impacting the brightness and chromaticity of the display. Due to the reduced luminous efficiency of red LEDs, most of their energy is lost through heat. Reducing the LED operating current can effectively improve chip heat generation and stabilize its thermal efficiency. In this embodiment, two or more red LEDs are connected in series to effectively reduce their operating current.

[0050] This application is based on microLED direct display technology. By adding one or more R and G sub-pixel designs to the conventional RGB pixel structure, the proportion of TFT power consumption in the panel power consumption is reduced, thereby reducing the overall power consumption of the panel; at the same time, the number of R chips in a pixel unit is increased, the light-emitting current and heat generation of a single R chip are reduced, and its light-emitting stability is improved. The number of G chips in a pixel unit is increased, the operating current range of the G chip under different driving modes of the glass base is narrowed, and the color deviation of the G chip is improved.

[0051] In one embodiment, the pixel driving circuit further includes a compensation module electrically connected to the driving module and the charge storage module, the compensation module is used to maintain a constant voltage value across the light-emitting chip electrically connected to the pixel driving circuit, and the compensation module includes at least one compensation TFT.

[0052] The 3T1C pixel driver circuit shown in Figures 5 and 6 includes a driver TFT_T1, a switch TFT_T2, a compensation TFT_T3, and a storage capacitor C1. ① Initialization Phase: The Gate Line and Sense Line are high, the switch TFT_T2 and compensation TFT_T3 are open, S1 is open, and Vg = Vdata_L, Vs = Vref. ② Vth Storage Phase: The Gate Line and Sense Line are set high, the switch TFT_T2 and compensation TFT_T3 are open, Vg = Vdata_H, the driver TFT_T1 is open, S1 and S2 are closed, and Vs is gradually charged from Vref to Vs = Vdata_H - Vth, where Vth is the threshold voltage of the driver TFT_T1. ③ Vth Detection Storage Phase: S1 is closed, S2 is open, Vref is not input, and the ADC (analog-to-digital converter) begins detecting data. Vgs = Vdata_H - Vs = Vdata_H - (Vdata_H - Vth) = Vth. Therefore, the compensation TFT_T3 maintains a constant voltage on the light-emitting chip.

[0053] On the basis of keeping the voltage value of the light-emitting chip constant, if the same brightness needs to be maintained, the driving current of the light-emitting chip is reduced to one-nth (n is the number of light-emitting chips, without considering the luminous efficiency), which significantly reduces the power consumption of the panel and increases the proportion of power consumption of the light-emitting chip. If the driving current of the light-emitting chip is maintained unchanged, the power consumption of the panel remains unchanged, but the power consumption of the light-emitting chip becomes n times, the panel brightness is improved, and the proportion of power consumption of the light-emitting chip is increased.

[0054] In addition, as shown in Figures 7 and 8, the 8T1C pixel driving circuit uses PAM (pulse amplitude modulation) driving to perform grayscale cutting using the Data amplitude method. The light-emitting principle is analyzed as follows:

[0055] 1. Reset point B and point G: T1 & T7 are turned on, Vb = Vdd, Vg = Vi;

[0056] 2. Data writing and Vth compensation, anode reset: T5&T8&T3 are turned on, Vb=Vdata, Vg=Vdd+Vth, Va=Vss;

[0057] 3. Light-emitting stage: EM (n) high level, T2 & T6 open, Vb drops from Vdata to Vi, Vb = Vdata - Vi, G point potential drops under the capacitor couple,

[0058] Vg=Vdd+Vth-△Vb=Vdd+Vth-(Vdata-Vi), Vgs-Vth=Vg-Vdd-Vth=Vi-Vdata, working in saturation region, driving current I=k*(Vgs-Vth) 2 =k*(Vi-Vdata) 2 , for, is the mobility of T4, is the gate oxide capacitance per unit area of ​​T4, W is the T4 channel width, and L is the T4 channel length.

[0059] In one embodiment, the 3T1C and 8T1C pixel driver circuits in the previous embodiment use PAM drive, or constant current drive. However, due to the inherent sorting characteristics and variability of LEDs, the brightness of each LED varies significantly under low current conditions, easily leading to uneven brightness. Therefore, under low grayscale conditions, PWM (Pulse Width Modulation) drive is often used to maintain the actual operating current of the LED at a relatively high value and adjust the average brightness by controlling the LED's light-emitting duration. Therefore, the pixel driver circuit includes a pulse width modulation (PWM) driver module and a pulse amplitude modulation (PAM) driver module, both of which are electrically connected to the light-emitting unit 2. If the grayscale of the image to be displayed by the light-emitting unit 2 is less than or equal to a preset grayscale (low grayscale), the PWM driver module in the pixel driver circuit drives the light-emitting unit 2 to emit light. If the grayscale of the image to be displayed by the light-emitting unit 2 is greater than the preset grayscale (high grayscale), the PAM driver module in the pixel driver circuit drives the light-emitting unit 2 to emit light. Therefore, a combined high-grayscale PAM drive and low-grayscale PWM drive drive method is used.

[0060] The 7T2C pixel driving circuit shown in Figure 9 is a combination of PAM driving and PWM driving. The T2 detection process is shown in Figure 10:

[0061] Step 1: Write PWM data line by line to turn off T4:

[0062] a. T5 & T6 are turned on, Vg = Vdd, Vp = PWM data, Vgs = PWM data - Vref = 0V, and T4 is turned off;

[0063] Step 2: Write PAM data to R / G / B, initialize S point & charge S point & detect T2 Vth:

[0064] a. Sweep decreases, causing Vp to decrease and T4 to remain closed;

[0065] b. PAM data is written, point S is initialized and charged, T1 and T3 are turned on, Vg = PAM data (R), Vs = Vref, after 1 minute switch 1 is turned off, and the potential of point S is charged from Vref to PAM data - Vth_T2;

[0066] c. Vth detection: wait until the potential at point S rises steadily before connecting the external detection module. Vgs = PAM data - (PAM data - Vth_T2) = Vth_T2.

[0067] d. After completing the Vth detection of R, repeat the above process to detect the Vth of GB.

[0068] The T4 detection process is shown in Figure 11:

[0069] Step 1: Write PWM data to R / G / B, initialize S1, charge S1, and detect T4 Vth:

[0070] a. PWM data is written, S1 is initialized and charged, T5 and T6 are turned on, Vg = Vdd, Vp = PWM data (R), Vs1 = Vref, after 1 minute, switch 1 is disconnected, and the potential of S1 is charged from Vref to PWM data - Vth_T4;

[0071] b. Vth detection: wait until the potential at point S1 rises steadily before connecting the external detection module. Vgs = PWM data - (PAM data - Vth_T4) = Vth_T4.

[0072] c. After completing the Vth detection of R, repeat the above process to detect the Vth of GB.

[0073] In the pixel driving circuit of the combined high-grayscale PAM drive and low-grayscale PWM drive described in this embodiment, the current of the light-emitting chip will have a large span when the driving mode is switched. Due to the material properties of the green light-emitting chip, it is easy to have a large color shift under a large current span. As shown in FIG12 , when the pixel driving circuit includes a pulse width modulation driving module and a pulse amplitude modulation driving module, and the pulse width modulation driving module and the pulse amplitude modulation driving module are both electrically connected to the third light-emitting chip 23, the third light-emitting chip 23 is configured as a green light-emitting chip. By using two or more green light-emitting chips in series, the range span of the green light operating current can be reduced while ensuring that the luminous brightness is not reduced. That is, when the pulse width modulation drive is adjusted to the pulse amplitude modulation drive, the change value of the current flowing through the green light-emitting chip is less than or equal to a preset threshold, thereby improving the color shift problem of the image caused by green light. The preset threshold is determined based on design requirements and is not specifically limited in this embodiment.

[0074] Using R n G m B's MIP (Micro LED in Package) lamp bead design can significantly improve the pain points of direct display applications. From the perspective of manufacturing feasibility, since microLEDs are usually chip sizes below 50μm, the MIP lamp bead package is generally not less than 200μm. From the perspective of process feasibility, the use of R in MIP is n G m The design of multiple chips in B is technologically feasible. Figure 13 is a schematic diagram of the manufacturing process flow of the direct display sample. Taking R2GB as an example, process (a) is to produce microLED chips that meet the size requirements through chip epitaxial structure production, and cut the chips into the required size by cutting. Process (b) is to transfer the RGB three-color microLED chips to a substrate containing circuits by mass transfer, and form a manufactured MIP lamp bead through packaging and cutting. The MIP lamp bead contains 4 RRGB chips. Process (c) is to transfer the MIP packaged lamp bead to the glass substrate through the crystal bonding process. Process (d) is to bake and cut the glass substrate to form a finished product. The above processes are all based on existing conventional processes and have mature mass production capabilities.

[0075] This application aims to use R n G m B's design increases the proportion of LED chip power consumption in the system power consumption and reduces the proportion of substrate driver TFT power consumption by designing the ratio of sub-pixel number. On the other hand, R n G mDesign B reduces the driving current of a single R chip and G chip, improving the instability of the R chip's luminescence with temperature rise. It also narrows the luminous current range of the G chip and improves the color shift of the G chip.

[0076] Table 1 shows the conventional RGB package MIP and R n G m Power consumption simulation results of B package MIP:

[0077] ①RGB is a light-emitting unit 2 that includes a red light-emitting chip, a green light-emitting chip, and a blue light-emitting chip. When the voltage difference between VDD and VSS of the pixel driving circuit corresponding to the red light-emitting chip is 12.1V and the current flowing through the red light-emitting chip is 47.274mA, the power consumption of the entire circuit of the red light-emitting chip and the corresponding pixel driving circuit is 1.14E-03W.

[0078] ②R2GB is light-emitting unit 2, which includes two red light-emitting chips, one green light-emitting chip and one blue light-emitting chip. Compared with ①RGB, ②R2GB only adds a red light-emitting chip in parallel. The green light-emitting chips and blue light-emitting chips of ①RGB and ②R2GB are arranged in the same way. In ②R2GB, when the voltage difference between VDD and VSS of the pixel driving circuit corresponding to the red light-emitting chip is 12.44V and the current flowing through the red light-emitting chip is 47.337mA, the power consumption of the entire circuit of the red light-emitting chip and the corresponding pixel driving circuit is 5.90E-04W.

[0079] ③ The RGB light-emitting unit 2 includes a red light-emitting chip, a green light-emitting chip, and a blue light-emitting chip. When the voltage difference between VDD and VSS of the pixel driving circuit corresponding to the green light-emitting chip is 12.1V and the current flowing through the green light-emitting chip is 20.95mA, the power consumption of the entire circuit of the green light-emitting chip and the corresponding pixel driving circuit is 5.10E-04.

[0080] ④RG2B is a light-emitting unit 2 that includes a red light-emitting chip, two green light-emitting chips, and a blue light-emitting chip. Compared with ③RGB, ④RG2B only adds a green light-emitting chip in parallel. The red and blue light-emitting chips of ③RGB and ④RG2B are arranged in the same way. In ④RG2B, when the voltage difference between VDD and VSS of the pixel driving circuit corresponding to the red light-emitting chip is 12.41V and the current flowing through the green light-emitting chip is 20.9mA, the power consumption of the entire circuit of the green light-emitting chip and the corresponding pixel driving circuit is 2.60E-04.

[0081] The data shows that, comparing package types ①RGB and ②R2GB, ②R2GB adds a red chip. The green and blue chip layouts of ①RGB and ②R2GB are identical, the current flowing through the red chip is similar, and the voltage difference between VDD and VSS of the pixel driver circuit corresponding to the red chip is similar. Consequently, the red chip in ①RGB and ②R2GB emits the same brightness, but the power consumption of ②R2GB is half that of ①RGB. Comparing package types ③RGB and ④RG2B, ④RG2B adds a green chip. The red and blue chip layouts of ③RGB and ④RG2B are identical, the current flowing through the green chip is half that of ③RGB, and the voltage difference between VDD and VSS of the pixel driver circuit corresponding to the green chip is similar. Consequently, the red chip in ③RGB and ④RG2B emits the same brightness, but the power consumption of ④RG2B is half that of ③RGB. This demonstrates that the power consumption of a single MIP to achieve the same brightness has been reduced by approximately half.

[0082] Table 1 Power consumption simulation

[0083] Package type Single color Current / mA Voltage / V Power consumption / W ①RGB47.27412.11.14E-03 ②R2GB47.33712.445.90E-04 ③RGB20.9512.15.10E-04 ④RG2B20.912.412.60E-04

[0084] The present application provides a display device, which includes the display panel as described in any one of the above embodiments.

[0085] In some embodiments, the first light-emitting chip provides blue light, the second light-emitting chip provides red light, and the third light-emitting chip provides green light; the light-emitting unit includes one first light-emitting chip, at least one second light-emitting chip, and at least one third light-emitting chip.

[0086] In some embodiments, the circuit after the pixel driving circuit is connected to the light-emitting chip is set between a first voltage value and a second voltage value, the maximum number of any light-emitting chips in the light-emitting unit is positively correlated with the voltage difference between the first voltage value and the second voltage value, the first voltage end is VDD, and the second voltage end is VSS.

[0087] In some embodiments, the number of second light-emitting chips in the light-emitting unit is 2-6.

[0088] In some embodiments, the number of third light-emitting chips in the light-emitting unit is 2-4.

[0089] In some embodiments, the light-emitting unit further includes a substrate and an encapsulation layer, the first light-emitting chip, the second light-emitting chip and the third light-emitting chip are bound to the substrate, and the encapsulation layer covers the first light-emitting chip, the second light-emitting chip and the third light-emitting chip.

[0090] In some embodiments, the light-emitting chips in the LED package module share a common cathode or a common anode.

[0091] In some embodiments, the first light-emitting chip, the second light-emitting chip, and the third light-emitting chip are alternately arranged in the light-emitting unit.

[0092] In some embodiments, the pixel driving circuit includes a driving module, a switching module and a charge storage module. The driving module and the light-emitting chip of the same color in the light-emitting unit are connected in series between the first voltage terminal and the second voltage terminal, and the driving module and the charge storage module are electrically connected. The first end of the switch module is connected to the scan signal, the second end of the switch module is connected to the data signal, and the third end of the switch module is connected to the driving module and the charge storage module.

[0093] In some embodiments, the pixel driving circuit further includes a compensation module electrically connected to the driving module and the charge storage module, and the compensation module is used to maintain a constant voltage value across the light-emitting chip electrically connected to the pixel driving circuit.

[0094] In some embodiments, the pixel driving circuit includes a pulse width modulation driving module and a pulse amplitude modulation driving module, both of which are electrically connected to the third light-emitting chip, and the third light-emitting chip is set to be a green light-emitting chip.

[0095] In some embodiments, if the grayscale of the image to be displayed by the light-emitting unit is less than or equal to a preset grayscale, the pulse width modulation driving module drives the third light-emitting chip to emit light; if the grayscale of the image to be displayed by the light-emitting unit is greater than the preset grayscale, the pulse amplitude modulation driving module drives the third light-emitting chip to emit light; when the pulse width modulation drive is adjusted to the pulse amplitude modulation drive, the change value of the current flowing through the third light-emitting chip is less than or equal to a preset threshold.

[0096] In some embodiments, the number of pixel driving circuits connected to the light-emitting unit is the same as the color of the light-emitting chips included in the light-emitting unit.

[0097] In some embodiments, the light-emitting unit further includes a fourth light-emitting chip, and the fourth light-emitting chip provides white light.

[0098] In the display panel and display device provided by the embodiments of the present application, a plurality of light-emitting chips of at least one color are provided in the light-emitting unit, and are electrically connected to the pixel driving circuit after being connected in series. Compared with connecting only one light-emitting chip, when multiple light-emitting chips are connected, the number of components connected in the pixel driving circuit increases, the current decreases, and the power consumption of the light-emitting chip part increases as a proportion of the panel power consumption, thereby reducing the overall power consumption of the panel.

[0099] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0100] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0101] The above is a detailed introduction to a display panel and a display device provided in the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the ideas of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A display panel, wherein: include: An array substrate, on which a plurality of pixel driving circuits are arranged; A plurality of light-emitting units, wherein an array of the plurality of light-emitting units is arranged on the array substrate, wherein the light-emitting units include a plurality of light-emitting chips, wherein the plurality of light-emitting chips include a first light-emitting chip, a second light-emitting chip and a third light-emitting chip, and the colors of the first light-emitting chip, the second light-emitting chip and the third light-emitting chip are different from each other; the number of light-emitting chips included in any of the light-emitting units is greater than the number of colors of the light-emitting chips; the light-emitting chips of the same color in the light-emitting units are connected in series, and the light-emitting chips of the same color in the light-emitting units are electrically connected to a pixel driving circuit; The first light-emitting chip provides blue light, the second light-emitting chip provides red light, and the third light-emitting chip provides green light; the light-emitting unit includes one first light-emitting chip, at least one second light-emitting chip, and at least one third light-emitting chip; The first light emitting chip, the second light emitting chip and the third light emitting chip are arranged alternately in the light emitting unit.

2. The display panel according to claim 1, wherein: The light-emitting unit is connected between a first voltage terminal and a second voltage terminal. The maximum number of any light-emitting chips in the light-emitting unit is positively correlated with the voltage difference between the first voltage terminal and the second voltage terminal. The first voltage terminal is VDD and the second voltage terminal is VSS.

3. The display panel according to claim 2, wherein: The number of the second light-emitting chips in the light-emitting unit is 2-6.

4. The display panel according to claim 2, wherein: The number of the third light-emitting chips in the light-emitting unit is 2-4.

5. The display panel according to claim 1, wherein: The light-emitting unit further includes a substrate and a packaging layer, the first light-emitting chip, the second light-emitting chip and the third light-emitting chip are bound to the substrate, and the packaging layer covers the first light-emitting chip, the second light-emitting chip and the third light-emitting chip.

6. A display panel, wherein: include: An array substrate, on which a plurality of pixel driving circuits are arranged; A plurality of light-emitting units, wherein an array of the plurality of light-emitting units is arranged on the array substrate, wherein the light-emitting units include a plurality of light-emitting chips, wherein the plurality of light-emitting chips include a first light-emitting chip, a second light-emitting chip and a third light-emitting chip, and the colors of the first light-emitting chip, the second light-emitting chip and the third light-emitting chip are different from each other; the number of light-emitting chips included in any of the light-emitting units is greater than the number of color types of the light-emitting chips; the light-emitting chips of the same color in the light-emitting units are connected in series, and the light-emitting chips of the same color in the light-emitting units are electrically connected to a pixel driving circuit.

7. The display panel according to claim 5, wherein: The first light-emitting chip provides blue light, the second light-emitting chip provides red light, and the third light-emitting chip provides green light; the light-emitting unit includes one first light-emitting chip, at least one second light-emitting chip, and at least one third light-emitting chip.

8. The display panel according to claim 7, wherein: The light-emitting unit is connected between a first voltage terminal and a second voltage terminal. The maximum number of any light-emitting chips in the light-emitting unit is positively correlated with the voltage difference between the first voltage terminal and the second voltage terminal. The first voltage terminal is VDD and the second voltage terminal is VSS.

9. The display panel according to claim 8, wherein: The number of the second light-emitting chips in the light-emitting unit is 2-6.

10. The display panel according to claim 8, wherein: The number of the third light-emitting chips in the light-emitting unit is 2-4.

11. The display panel according to claim 7, wherein: The light-emitting unit further includes a substrate and a packaging layer, the first light-emitting chip, the second light-emitting chip and the third light-emitting chip are bound to the substrate, and the packaging layer covers the first light-emitting chip, the second light-emitting chip and the third light-emitting chip.

12. The display panel according to claim 11, wherein: The light-emitting chips in the light-emitting unit share a cathode or an anode.

13. The display panel according to claim 6, wherein: The first light emitting chip, the second light emitting chip and the third light emitting chip are arranged alternately in the light emitting unit.

14. The display panel according to claim 6, wherein: The pixel driving circuit includes a driving module, a switch module and a charge storage module. The driving module is connected in series with the light-emitting chip of the same color in the light-emitting unit, and the driving module and the charge storage module are electrically connected. The first end of the switch module is connected to the scanning signal, the second end of the switch module is connected to the data signal, and the third end of the switch module is connected to the driving module and the charge storage module.

15. The display panel according to claim 14, wherein: The pixel driving circuit further comprises a compensation module electrically connected to the driving module and the charge storage module, and the compensation module is used to keep a constant voltage value at both ends of the light emitting chip electrically connected to the pixel driving circuit.

16. The display panel according to claim 6, wherein: The pixel driving circuit includes a pulse width modulation driving module and a pulse amplitude modulation driving module. Both the pulse width modulation driving module and the pulse amplitude modulation driving module are electrically connected to the third light emitting chip. The third light emitting chip is set as a green light emitting chip.

17. The display panel according to claim 16, wherein: If the grayscale of the image to be displayed by the light-emitting unit is less than or equal to the preset grayscale, the pulse width modulation driving module drives the third light-emitting chip to emit light; If the grayscale of the image to be displayed by the light-emitting unit is greater than the preset grayscale, the pulse amplitude modulation driving module drives the third light-emitting chip to emit light; When the pulse width modulation driving is adjusted to the pulse amplitude modulation driving, the change value of the current flowing through the third light-emitting chip is less than or equal to the preset threshold.

18. The display panel according to claim 6, wherein: The number of pixel driving circuits connected to the light emitting unit is the same as the type of colors of the light emitting chips included in the light emitting unit.

19. The display panel according to claim 6, wherein: The light emitting unit further includes a fourth light emitting chip, and the fourth light emitting chip provides white light.

20. A display device, wherein: The display device comprises the display panel according to any one of claims 1 to 19.

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