Display panel and pixel driving circuit, method and device thereof

Abstract

The present application relates to a display panel and a pixel driving circuit, method and device thereof. A pulse width modulation circuit module performs pulse width modulation according to a digital data signal output by a data buffer to output a target pulse width signal, and a trapezoidal wave signal is output according to a pulse input signal and a polarity inversion signal of the display panel through a trapezoidal generator module, so that a data charging switch module in the display panel outputs a driving voltage signal to a pixel in the display panel based on the trapezoidal wave signal under the control of the target pulse width signal, thereby realizing data driving, saving costs and reducing a large amount of driving power consumption, thereby solving the problem of high data driving power consumption existing in the existing related technologies.

Description

Technical Field

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

[0002] With the rapid development of display technology, display devices such as liquid crystal displays (LCD) are becoming more and more popular, bringing great convenience to people's life, work and study.

[0003] At present, LCD panels are mainly composed of data lines, scan lines, thin film transistors (TFT), liquid crystal light valves, RGB filters, and upper and lower polarizers. Its working principle is: the scan line first turns on the first row of TFTs, and then the data line sends the data voltage of each pixel in the first row to control the deflection angle of the liquid crystal, that is, to control the amount of light passing through the liquid crystal light valve to achieve different grayscale displays, and then pass through the RGB filters to achieve color display.

[0004] The traditional TFT-LCD data input architecture stores data in the data buffer, and then passes through the level converter to provide sufficient voltage swing to drive the digital to analog converter (DAC) to generate various grayscale voltages, and finally uses the output buffer to provide sufficient driving capability for the data line. However, TFT-LCD uses a decoding DAC with a large-area MOS tube cluster as the main structure. The high-frequency switching of the MOS tube will bring a lot of power consumption. Summary of the invention

[0005] In view of this, the present application provides a display panel and its pixel driving circuit, method, and device to further digitize the data input architecture of the display panel and reduce driving power consumption.

[0006] In a first aspect, an embodiment of the present application provides a pixel driving circuit of a display panel, comprising: a data buffer, a pulse width modulation circuit module, a trapezoidal generator module, and a data charging switch module in the display panel;

[0007] The data buffer is used to output the digital data signal of the display panel;

[0008] The pulse width modulation circuit module is used to perform pulse width modulation according to the digital data signal and output a target pulse width signal;

[0009] The trapezoidal generator module is used to output a trapezoidal wave signal according to a pulse input signal and a polarity inversion signal of the display panel;

[0010] The data charging switch module is used to output a driving voltage signal to the pixels in the display panel based on the trapezoidal wave signal under the control of the target pulse width signal.

[0011] Optionally, the trapezoidal wave signal is divided into a positive phase trapezoidal wave signal and an inverted phase trapezoidal wave signal, and the trapezoidal generator module includes: an input switch unit, an inverting amplification unit and an inverting integration unit;

[0012] The input end of the input switch unit is used to receive the pulse input signal, the control end of the input switch unit is used to receive the polarity reversal signal of the display panel, the output end of the input switch unit is electrically connected to the inverting input end of the inverting amplifier unit, the output end of the inverting amplifier unit is electrically connected to the input end of the inverting integration unit, and the output end of the inverting integration unit is electrically connected to the input end of the data charging switch module;

[0013] When the polarity reversal signal is a first level signal, the input switch unit is used to transmit the pulse input signal to the inverting amplification unit, and the output end of the inverting integration unit is used to output the positive phase trapezoidal wave signal;

[0014] When the polarity inversion signal is a second level signal, the input switch unit is used to transmit the inverted signal of the pulse input signal to the inverting amplification unit, and the output end of the inverting integration unit is used to output the inverted trapezoidal wave signal.

[0015] Optionally, the input switch unit includes an analog switch and an inverter;

[0016] The first output end of the analog switch, the output end of the inverter and the inverting input end of the inverting amplifying unit are electrically connected, and the second output end of the analog switch is electrically connected to the input end of the inverter;

[0017] When the polarity inversion signal is a first level signal, the input end of the analog switch is electrically connected to the first output end of the analog switch;

[0018] When the polarity inversion signal is a second level signal, the input end of the analog switch is electrically connected to the second output end of the analog switch.

[0019] Optionally, the inverting amplification unit includes: an amplifier, a first resistor, a second resistor and a third resistor; the first end of the first resistor is electrically connected to the output end of the input switch unit, the second end of the first resistor, the inverting input end of the amplifier and the second end of the second resistor are electrically connected, the non-inverting input end of the amplifier is electrically connected to the reference ground of the pixel driving circuit through the third resistor, and the output end of the amplifier, the first end of the second resistor and the input end of the inverting integration unit are electrically connected.

[0020] Optionally, the inverting integration unit includes: an integrator, a fourth resistor, a fifth resistor and a first capacitor;

[0021] The first end of the fourth resistor is electrically connected to the output end of the inverting amplification unit, the second end of the fourth resistor, the inverting input end of the integrator, the first end of the first capacitor and the second end of the fifth resistor are electrically connected, the non-inverting input end of the integrator is electrically connected to the reference ground of the pixel driving circuit, and the output end of the integrator, the second end of the first capacitor, the first end of the fifth resistor and the input end of the data charging switch module are electrically connected.

[0022] Optionally, the pulse width modulation circuit module includes: a pulse width modulation unit and a level shifter;

[0023] The pulse width modulation unit is used to adjust the pulse duty cycle based on the digital data signal and the charging control information corresponding to the pixel, and output an initial pulse width signal based on the adjusted pulse duty cycle;

[0024] The level shifter is used to perform level shifting based on the initial pulse width signal and output the target pulse width signal corresponding to the digital data signal.

[0025] Optionally, the data charging switch module includes: a data switch transistor;

[0026] The first end of the data switch transistor is electrically connected to the output end of the trapezoidal generator module, the second end of the data switch transistor is electrically connected to the pixel through the data line of the display panel, and the control end of the data switch transistor is electrically connected to the output end of the pulse width modulation circuit module.

[0027] In a second aspect, an embodiment of the present application provides a driving method of a pixel driving circuit of a display panel, which is applied to the pixel driving circuit of the display panel as described in any one of the first aspects above, including:

[0028] Outputting the digital data signal of the display panel through the data buffer;

[0029] Performing pulse width modulation according to the digital data signal to output a target pulse width signal, and outputting a trapezoidal wave signal according to a pulse input signal and a polarity inversion signal of the display panel;

[0030] Under the control of the target pulse width signal, a driving voltage signal is output to pixels in the display panel based on the trapezoidal wave signal.

[0031] In a third aspect, an embodiment of the present application provides a display panel, comprising a pixel driving circuit of the display panel as described in any one of the first aspects.

[0032] In a fourth aspect, an embodiment of the present application provides a display device, comprising: a display panel as described in the third aspect and a power supply module, wherein the power supply module is used to control power supply to the display panel.

[0033] In summary, the display panel and its pixel driving circuit, method, and device provided in the embodiment of the present application perform pulse width modulation according to the digital data signal output by the data buffer through the pulse width modulation circuit module, output the target pulse width signal, and output the trapezoidal wave signal according to the pulse input signal and the polarity reversal signal of the display panel through the trapezoidal generator module, so that the data charging switch module in the display panel outputs the driving voltage signal to the pixel in the display panel based on the trapezoidal wave signal under the control of the target pulse width signal, thereby realizing data driving. Compared with the existing related technologies, the embodiment of the present application removes the bloated DAC conversion module and the subsequent BUFFER module under the traditional architecture, and adopts pulse width modulation combined with the trapezoidal wave signal output by the trapezoidal wave generator module to realize data driving, which saves costs and reduces a lot of driving power consumption, and solves the problem of high data driving power consumption caused by the high frequency switching of the MOS tube in the existing related technologies. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0036] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0037] Figure 1 A schematic structural diagram of a pixel driving circuit of a display panel provided in an embodiment of the present application;

[0038] Figure 2 A schematic diagram of the circuit structure of a trapezoidal generator module provided in an optional embodiment of the present application;

[0039] Figure 3 It is a schematic diagram of setting a dual trapezoidal wave generator drive through a polarity inversion signal POL in an example of the present application;

[0040] Figure 4 A schematic diagram of converting a digital data signal into a pulse width signal with different duty cycles through a pulse modulation link in an example of the present application;

[0041] Figure 5 A schematic diagram of a pixel driving circuit of a display panel provided as an example of the present application;

[0042] Figure 6 A schematic diagram of a charging curve of a pixel capacitor charged under a trapezoidal wave voltage provided in an example of the present application;

[0043] Figure 7 A schematic diagram of a charging curve of a pixel capacitor charged at a constant voltage provided in an example of the present application;

[0044] Figure 8 A schematic diagram of charging a pixel capacitor through a data switch transistor provided in an example of the present application;

[0045] Fig. 9 A schematic flow chart of the steps of a pixel driving method of a display panel provided in an embodiment of the present application;

[0046] Fig.10 A structural block diagram of a display panel provided in an embodiment of the present application;

[0047] Fig.11 A structural block diagram of a display device provided in an embodiment of the present application.

[0048] Among them, VAA is the first power supply terminal, VSS is the second power supply terminal, Vi is the pulse input signal, Vt is the trapezoidal wave signal, POL is the polarity reversal signal, 110 is the data buffer, 120 is the pulse width modulation circuit module, 130 is the trapezoidal generator module, 140 is the data charging switch module, 210 is the input switch unit, 220 is the inverting amplification unit, 230 is the inverting integration unit, SW1 is the analog switch, B is the first output terminal of the analog switch SW1, A is the second output terminal of the analog switch SW1, OP1 is the amplifier, R1 is the first resistor, R2 is the second resistor, R3 is the third resistor R3, OP2 is the integrator, R4 is the fourth resistor, R5 is the fifth resistor, C1 is the first capacitor, Q is the data switch transistor, CLK is the clock signal, Vcp is the capacitance value of the pixel capacitor, 900 is the display panel, 910 is the pixel driving circuit, 1100 is the display device, and 1011 is the power supply module. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are 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 ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0050] The disclosure below provides many different embodiments or examples to implement different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0051] In the specific implementation, if TFT-LCD uses a decoding DAC with a large-area MOS tube cluster as the main structure, the high-frequency switching of the MOS tube will bring a lot of power consumption. In addition, each channel needs to be output through the output buffer to provide driving capability. The output buffer is essentially a voltage follower composed of an operational amplifier (OP), which will also bring a lot of power consumption. The common methods for optimizing the power consumption of the source driver are mainly to improve the efficiency of the source driver, reduce the mold area, and increase the conversion rate of the buffer or use half-voltage drive in the output buffer part. However, on the basis of realizing the digital mechanism of receiving, distributing and storing video data, DAC and unity gain amplifier are still used to convert digital data signals into pixel driving voltages, which does not solve the fundamental problem of bringing a lot of power consumption. Such a mixed signal configuration makes the design of the source driver more complicated and it is more difficult to reduce power consumption.

[0052] In order to solve the above-mentioned problem of large power consumption caused by the high-frequency switching of MOS tubes, the embodiments of the present application provide a display panel and its pixel driving circuit, method, and device. Through a pulse width modulation circuit module, pulse width modulation is performed according to the digital data signal output by a data buffer to output a target pulse width signal, and a trapezoidal wave signal is output according to a pulse input signal and a polarity reversal signal of the display panel through a trapezoidal generator module, so that the data charging switch module in the display panel can output a driving voltage signal to the pixels in the display panel based on the trapezoidal wave signal under the control of the target pulse width signal, thereby realizing data driving, removing the DAC conversion module and the subsequent output buffer (BUFFER) module under the traditional architecture, saving costs, and reducing a large amount of driving power consumption.

[0053] Figure 1 A schematic diagram of the structure of a pixel driving circuit of a display panel provided in an embodiment of the present application. The pixel driving circuit provided in this embodiment may specifically include: a data buffer 110, a pulse width modulation circuit module 120, a trapezoidal generator module 130, and a data charging switch module 140 in the display panel. The data buffer 110 is used to output the digital data signal of the display panel; the pulse width modulation circuit module 120 is used to perform pulse width modulation according to the digital data signal and output a target pulse width signal; the trapezoidal generator module 130 is used to output a trapezoidal wave signal Vt according to a pulse input signal Vi and a polarity inversion signal POL of the display panel; the data charging switch module 140 is used to output a driving voltage signal to the pixel in the display panel based on the trapezoidal wave signal Vt under the control of the target pulse width signal.

[0054] Specifically, the pixel driving circuit provided in the embodiment of the present application can be used as a data driving circuit of a display panel. The video data required to be displayed on the display panel can be cached through the data buffer 110, and a digital data signal can be output based on the cached video data to the pulse width modulation circuit module 120, so that the pulse width modulation circuit module 120 performs pulse width modulation, converts the digital data signal into a digital pulse width signal, and outputs it to the data charging switch module 140 as a target pulse width signal, so that the data charging switch module 140 can be controlled by the target pulse width signal, and the trapezoidal wave signal Vt is output to the data charging switch module 140 according to the pulse input signal Vi and the polarity inversion signal POL of the display panel through the trapezoidal generator module 130, so that the data charging switch module 140 in the display panel can output a driving voltage signal to the pixels in the display panel based on the trapezoidal wave signal Vt under the control of the target pulse width signal to realize data driving.

[0055] It can be seen that the pixel driving circuit provided in the embodiment of the present application performs pulse width modulation according to the digital data signal output by the data buffer 110 through the pulse width modulation circuit module 120, outputs the target pulse width signal, and outputs the trapezoidal wave signal Vt according to the pulse input signal Vi and the polarity reversal signal POL of the display panel through the trapezoidal generator module 130, so that the data charging switch module 140 in the display panel can output the driving voltage signal to the pixel in the display panel based on the trapezoidal wave signal Vt under the control of the target pulse width signal, thereby realizing data driving. Compared with the existing related art, the embodiment of the present application removes the bloated DAC conversion module and the subsequent BUFFER module under the traditional architecture, so as to further digitize the data input architecture of the display panel, and realizes data driving by using pulse width modulation combined with the trapezoidal wave signal Vt output by the trapezoidal wave generator module, thereby saving costs and reducing a large amount of driving power consumption, thereby solving the problem of high power consumption caused by the high frequency switching of the MOS tube in the existing related art.

[0056] In some optional embodiments of the present application, in order to achieve the horizontal polarity inversion of pixels to meet the flicker balance requirement, the trapezoidal wave signal output by the trapezoidal generator module 130 according to the pulse input signal Vi and the polarity inversion signal POL can be divided into a positive phase trapezoidal wave signal and a negative phase trapezoidal wave signal. Figure 2As shown, the trapezoidal generator module 130 in the embodiment of the present application includes: an input switch unit 210, an inverting amplifier unit 220 and an inverting integration unit 230; the input end of the input switch unit 210 is used to receive the pulse input signal Vi, the control end of the input switch unit 210 is used to receive the polarity reversal signal POL of the display panel, the output end of the input switch unit 210 is electrically connected to the inverting input end of the inverting amplifier unit 220, the output end of the inverting amplifier unit 220 is electrically connected to the input end of the inverting integration unit 230, and the output end of the inverting integration unit 230 is electrically connected to the input end of the data charging switch module 140; when the polarity reversal signal POL is a first level signal, the input switch unit 210 is used to transmit the pulse input signal Vi to the inverting amplifier unit 220, so as to invert and amplify the pulse input signal Vi through the inverting amplifier unit 220, and then transmit the inverted amplified signal to the inverting integration unit 230, so as to be transmitted through The inverting integration unit 230 performs inverting integration and outputs a positive trapezoidal wave signal to the data charging switch module 140, so that the data charging switch module 140 can output a driving voltage signal to the pixel in the display panel based on the positive trapezoidal wave signal, and the output end of the inverting integration unit 230 is used to output the positive trapezoidal wave signal; when the polarity reversal signal POL is a second level signal, the input switch unit 210 is used to transmit the inverted signal of the pulse input signal Vi to the inverting amplifier unit 220, so as to perform inverting amplification on the inverted signal of the pulse input signal Vi through the inverting amplifier unit 220, and then transmit the inverted amplified signal to the inverting integration unit 230, so as to perform inverting integration through the inverting integration unit 230, and output the inverted trapezoidal wave signal to the data charging switch module 140, so that the data charging switch module 140 can output a driving voltage signal to the pixel in the display panel based on the inverted trapezoidal wave signal, and the output end of the inverting integration unit 230 is used to output the inverted trapezoidal wave signal.

[0057] It can be seen that the embodiment of the present application controls the input switch unit 210 through the polarity reversal signal POL of the display panel, and can control the trapezoidal wave signal Vt output by the trapezoidal generator module 130 to achieve the pixel polarity reversal function and ensure normal display. Optionally, the input switch unit 210 in the embodiment of the present application may include an analog switch SW1 and an inverter; the first output terminal B of the analog switch SW1, the output terminal of the inverter and the inverting input terminal of the inverting amplifier unit 220 are electrically connected, and the second output terminal A of the analog switch SW1 is electrically connected to the input terminal of the inverter; when the polarity reversal signal POL is a first level signal, the input terminal of the analog switch SW1 is electrically connected to the first output terminal B of the analog switch SW1; when the polarity reversal signal POL is a second level signal, the input terminal of the analog switch SW1 is electrically connected to the second output terminal A of the analog switch SW1.

[0058] In an optional embodiment of the present application, the inverting amplification unit 220 includes: an amplifier OP1, a first resistor R1, a second resistor R2 and a third resistor R3; the first end of the first resistor R1 is electrically connected to the output end of the input switch unit 210, the second end of the first resistor R1, the inverting input end of the amplifier OP1 and the second end of the second resistor R2 are electrically connected, the non-inverting input end of the amplifier OP1 is electrically connected to the reference ground of the pixel driving circuit through the third resistor R3, and the output end of the amplifier OP1, the first end of the second resistor R2 and the input end of the inverting integration unit 230 are electrically connected.

[0059] Optionally, the inverting integration unit 230 in the embodiment of the present application includes: an integrator OP2, a fourth resistor R4, a fifth resistor R5 and a first capacitor C1; the first end of the fourth resistor R4 is electrically connected to the output end of the inverting amplification unit 220, the second end of the fourth resistor R4, the inverting input end of the integrator OP2, the first end of the first capacitor C1 and the second end of the fifth resistor R5 are electrically connected, the non-inverting input end of the integrator OP2 is electrically connected to the reference ground of the pixel driving circuit, and the output end of the integrator OP2, the second end of the first capacitor C1, the first end of the fifth resistor R5 and the input end of the data charging switch module 140 are electrically connected.

[0060] As an example of the present application, when a high-level signal is used as the first-level signal and a low-level signal is used as the second-level signal, a pulse width modulation (PWM) wave signal with a fixed duty cycle and an amplitude of 0~3.3V can be generated by the screen driver board TCON, and input as a pulse input signal Vi to the input end of the analog switch SW1, so that the trapezoidal generator module 130 can output a trapezoidal wave signal Vt according to the pulse input signal Vi and the polarity reversal signal POL of the display panel. Specifically, when the polarity reversal signal POL of the display panel is a high-level signal, the trapezoidal generator module 130 generates a positive-phase trapezoidal wave signal. Specifically, the pulse input signal Vi does not pass through the inverting link, that is, the analog switch SW1 is thrown to the first output terminal B, and the pulse input signal Vi directly passes through the first output terminal B of the analog switch SW1 and enters the inverting amplifier unit 220 composed of the first resistor R1, the second resistor R2, the amplifier OP1, and the third resistor R3. The inverting amplifier unit 220 serves as an inverting proportional amplification link, and its amplification factor is -R2 / R1; after inverting amplification, the signal enters the inverting integration unit 230 composed of the fourth resistor R4, the fifth resistor R5, the first capacitor C1, and the integrator OP2. The inverting integration unit 230, as an inverting integration link, can perform an integration operation on the ramp signal, so that the trapezoidal generator module 130 can output a ramp signal with a fixed slope in the time period when the voltage is 3.3V, and the signal amplitude output in the time period when the voltage is 0V remains unchanged, thereby forming a trapezoidal wave signal Vt output. At this time, the output trapezoidal wave signal Vt is a positive phase trapezoidal wave signal. When the polarity reversal signal POL of the display panel is a low-level signal, the trapezoidal generator module 130 inverts the trapezoidal wave signal, and the analog switch SW1 is thrown to the second output terminal A. The pulse input signal Vi directly passes through the second output terminal A of the analog switch SW1, and through the inverting link, enters the inverting amplification unit 220 composed of the first resistor R1, the second resistor R2, the amplifier OP1, and the third resistor R3, and the inverting integration unit 230 composed of the fourth resistor R4, the fifth resistor R5, the first capacitor C1, and the integrator OP2, so that the trapezoidal wave signal Vt output by the trapezoidal generator module 130 can be an inverted trapezoidal wave signal through inverting amplification and inverting integration.

[0061] It can be seen that the analog switch SW1 controlled by the polarity reversal signal POL in the embodiment of the present application can realize the polarity reversal function of the pixel in the longitudinal direction. For example, in order to realize the polarity reversal of the pixel in the transverse direction and meet the flicker balance requirement, a dual trapezoidal wave generator drive can be set based on the circuit structure of the trapezoidal wave generator module through the polarity reversal signal POL, such as Figure 3As shown, the data lines of the first row with positive polarity / negative polarity can be connected to the trapezoidal wave generator 1 / trapezoidal wave generator 2 respectively according to the polarity of the first row of pixel data. The A and B ends of the analog switch SW1 of the trapezoidal wave generator 2 are opposite to those of the trapezoidal wave generator 1, that is, the polarity control effect of the polarity inversion signal POL on the two is opposite. Similarly, by modifying the above scheme, various types of polarity inversion architectures can be satisfied.

[0062] In addition, in the embodiment of the present application, after the data buffer outputs the digital data signal of the display panel, the pulse width modulation circuit module performs pulse width modulation according to the digital data signal to generate a PWM signal by pulse width modulation, and can provide sufficient driving voltage through the level shifter to control the data switch transistor in the data switch module, so that the PWM wave can be combined with the trapezoidal wave signal output by the trapezoidal wave generator module to realize data driving.

[0063] In some optional embodiments of the present application, the pulse width modulation circuit module 120 may include: a pulse width modulation unit and a level shifter; the pulse width modulation unit is used to adjust the pulse duty cycle based on the digital data signal and in combination with the charging control information corresponding to the pixel, and output an initial pulse width signal based on the adjusted pulse duty cycle; the level shifter is used to perform level shifting based on the initial pulse width signal and output the target pulse width signal corresponding to the digital data signal.

[0064] For example, in order to further digitize the data input structure of the display panel, the pulse width modulation unit in the pulse width modulation circuit module 120 can be used as a pulse width modulation link to convert the digital data signal into a pulse width signal with different duty ratios according to a certain rule through the pulse width modulation link. The duty ratio depends on the data size corresponding to the digital data signal and the charging curve of the pixel capacitor under the voltage of the trapezoidal wave signal. The conversion process is as follows: Figure 4 As shown, that is, within a PWM signal cycle T, the duty cycle corresponding to the pulse width signal is determined by the charging curve of the pixel capacitor under the trapezoidal voltage, and the function of this pulse width signal is to drive the charging switch in the data switch module, and the charging switch is the data switch transistor Q in the data switch module, as shown in FIG. Figure 5 The data size corresponding to the digital data signal may refer to the grayscale size corresponding to the digital data signal. For example, when the digital data signal is 01000000, the corresponding data size is 128 grayscales.

[0065] Optionally, the data charging switch module 140 in the embodiment of the present application includes: a data switch transistor Q; the first end of the data switch transistor Q is electrically connected to the output end of the trapezoidal generator module 130, the second end of the data switch transistor Q is electrically connected to the pixel through the data line of the display panel, and the control end of the data switch transistor Q is electrically connected to the output end of the pulse width modulation circuit module 120, so that the data switch transistor Q can output a driving voltage signal to the pixel in the display panel based on the trapezoidal wave signal under the control of the target pulse width signal to realize data driving.

[0066] For example, in order to further digitize the data input architecture of the TFT-LCD panel, a data buffer can be formed by latch 1 and latch 2 in the external integrated circuit of the display panel, so that the image data required to be displayed by the display panel can be cached by the data buffer, so that the data buffer can output the digital data signal of the display panel based on the cached image data. Specifically, the image data required to be displayed by the display panel can be transmitted to latch 1 for latching through a shift register, such as an S-bidirectional shift register, based on a clock signal CLK, and the data buffer can output the latched digital data signal to a pulse width modulation circuit module, such as a pulse width modulation circuit module, through latch 2. Figure 5 As shown, the digital data signal stored in the latch 2 is converted into a pulse width signal with different duty ratios according to certain rules through a pulse width modulation unit. The duty ratio depends on the size of the data and the charging time corresponding to the grayscale voltage of the pixel capacitor in the charging curve of the trapezoidal wave voltage. The trapezoidal wave voltage refers to the voltage of the trapezoidal wave signal. The specific conversion process is as follows: Figure 4 After the pulse width modulation unit converts the digital data signal into a pulse width signal with different duty cycles, the pulse width signal can be used as an initial pulse width signal and transmitted to the level shifter, so that the level shifter can provide sufficient driving voltage to form a target pulse width signal, which is output to the data switch transistor Q in the display panel to control the data switch transistor Q through the target pulse width signal.

[0067] In addition, based on the polarity reversal signal POL of the display panel, two trapezoidal wave generators, namely trapezoidal wave generator 1 and trapezoidal wave generator 2, can be formed through the trapezoidal wave generator module, so that the trapezoidal wave signal can be output to the data switch transistor Q of the odd rows in the display panel through the trapezoidal wave generator 1, and the trapezoidal wave signal can be output to the data switch transistor Q of the even rows in the display panel through the trapezoidal wave generator 2, so as to charge the pixels on the data line and the row selected by the on-chip gate driver through the data switch transistor Q based on the voltage of the trapezoidal wave signal, and by controlling the width of the pulse, the data line switch transistor Q can be turned off at an appropriate time to set the selected pixel to the target voltage. Among them, the on-chip gate driver refers to a gate driver connected to each row of pixels in the pixel array of the display panel through the gate line in the display panel.

[0068] In an optional method of the present application, the pixel capacitor CP of the display panel may be firstly extracted to obtain its capacitance Vcp, and then its charging curve under a certain constant voltage may be obtained based on the capacitance Vcp of the pixel capacitor, such as: Figure 7 When the pixel capacitor is not fully charged, the voltage across the pixel capacitor is in a proportional function relationship with the charging time, that is, a certain voltage can be obtained by controlling the charging time. Therefore, in the embodiment of the present application, the trapezoidal generator in the trapezoidal generator module outputs a trapezoidal wave signal to charge the pixel capacitor with a trapezoidal wave, thereby facilitating a more delicate control of the grayscale voltage.

[0069] In addition, considering that the human eye is more sensitive to low grayscale brightness changes, the embodiment of the present application can use a linearly rising ramp wave in the front stage of trapezoidal wave charging to slow down the rising speed of the voltage across the pixel capacitor Vcp in the early stage of capacitor charging, so as to facilitate the control of the grayscale voltage by controlling the charging time; in the latter stage of trapezoidal wave charging, the pixel capacitor is not yet fully charged, and charging with a constant voltage can still ensure that the voltage across the capacitor is increased. Compared with continuing to use the ramp wave, power consumption can be reduced. Therefore, a constant voltage is used for charging in the latter stage of trapezoidal wave charging instead of a ramp waveform, thereby achieving the effect of reducing power consumption.

[0070] For example, according to Figure 6 The charging curve of the pixel capacitor under the trapezoidal wave given in can be used to specify the PWM wave duty cycle used to control the data switch transistor Q to achieve accurate control of each gray scale, such as Figure 6 The t128 in the figure refers to the time it takes to charge the pixel capacitor to 128 gray levels. Figure 8The charging time of the pixel capacitor shown in the figure through the data switch transistor can determine the PWM signal duty cycle corresponding to the 128 gray scales, so that the pulse width modulation circuit module can output the target pulse width signal corresponding to the 128 gray scales based on the PWM signal duty cycle, and transmit it to the data switch transistor Q, so as to control the conduction charging time of the data switch transistor Q through the target pulse width signal to realize data driving.

[0071] Furthermore, an embodiment of the present application also provides a pixel driving method of a display panel, which is applied to a pixel driving circuit of a display panel as described in any one of the above embodiments. Fig. 9 As shown, a pixel driving method of a display panel provided in an embodiment of the present application may specifically include the following steps:

[0072] Step S101, outputting a digital data signal of a display panel through a data buffer;

[0073] Step S102, performing pulse width modulation according to the digital data signal, outputting a target pulse width signal, and outputting a trapezoidal wave signal according to a pulse input signal and a polarity inversion signal of the display panel;

[0074] Step S103 , under the control of the target pulse width signal, outputting a driving voltage signal to the pixels in the display panel based on the trapezoidal wave signal.

[0075] It can be seen that the embodiment of the present application outputs the digital data signal of the display panel through the data buffer, performs pulse width modulation according to the digital data signal, outputs the target pulse width signal, and outputs the trapezoidal wave signal according to the pulse input signal and the polarity inversion signal of the display panel, so that under the control of the target pulse width signal, a driving voltage signal can be output to the pixels in the display panel based on the trapezoidal wave signal, so that pulse width modulation combined with the trapezoidal wave signal can be used to realize data driving, thereby removing the DAC conversion module and the subsequent output buffer module under the traditional architecture, saving costs and reducing a large amount of driving power consumption.

[0076] Furthermore, an embodiment of the present application provides a display panel. Fig.10 As shown, the display panel 900 in the embodiment of the present application includes: a pixel driving circuit 910 of the display panel, which can be used as a data driving circuit of the display panel, and specifically can be a pixel driving circuit of any display panel provided in the above embodiments of the present invention. Since the principle of solving the problem of the display panel is similar to that of the pixel driving circuit of the above-mentioned display panel, the implementation of the pixel driving circuit of the display panel in the display panel can refer to the implementation of the pixel driving circuit of the display panel in the above-mentioned example, and the repeated parts will not be repeated.

[0077] The embodiment of the present invention further provides a display device, comprising the display panel provided by the embodiment of the present invention and a power supply module, wherein the power supply module is used to control the power supply to the display panel. Fig.11 As shown, the display device 1100 includes: a display panel 900 and a power supply module 1011, wherein the power supply module 1011 is used to control the power supply to the display panel 900; wherein the display panel 900 may be the display panel described in the above embodiment. In a specific implementation, the display device may be a display, a mobile phone, a television, a laptop computer, an electronic paper, a digital photo frame, a navigator, etc., and this application does not impose any specific restrictions on this.

[0078] The panel and device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, i.e., they may be located in one place or distributed over multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0079] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a general hardware platform, and of course, by hardware. Based on this understanding, the above technical solution, in essence, or the part that contributes to the relevant technology, can be embodied in the form of a software product, which can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiment.

[0080] It should be understood that the terms used herein are only for the purpose of describing specific example embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used herein may also be meant to include plural forms. The terms "include", "comprise", "contain", and "have" are inclusive, and therefore specify the existence of stated features, steps, operations, elements and / or parts, but do not exclude the existence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The method steps, processes, and operations described herein are not interpreted as necessarily requiring them to be performed in the specific order described or illustrated, unless the execution order is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0081] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A pixel driving circuit for a display panel, characterized in that: include: A data buffer, a pulse width modulation circuit module, a trapezoidal generator module, and a data charging switch module in a display panel; The data buffer is used to output the digital data signal of the display panel; The pulse width modulation circuit module is used to perform pulse width modulation according to the digital data signal and output a target pulse width signal; The trapezoidal generator module is used to output a trapezoidal wave signal according to a pulse input signal and a polarity inversion signal of the display panel; The data charging switch module is used to output a driving voltage signal to a pixel in the display panel based on the trapezoidal wave signal under the control of the target pulse width signal; Wherein, the pulse width modulation circuit module includes: a pulse width modulation unit and a level shifter; The pulse width modulation unit is used to adjust the pulse duty cycle based on the digital data signal and the charging control information corresponding to the pixel, and output an initial pulse width signal based on the adjusted pulse duty cycle; The level shifter is used to perform level shifting based on the initial pulse width signal and output the target pulse width signal corresponding to the digital data signal.

2. The pixel driving circuit of the display panel according to claim 1, characterized in that: The trapezoidal wave signal is divided into a positive phase trapezoidal wave signal and an inverted phase trapezoidal wave signal, and the trapezoidal generator module includes: an input switch unit, an inverted amplification unit and an inverted integration unit; The input end of the input switch unit is used to receive the pulse input signal, the control end of the input switch unit is used to receive the polarity reversal signal of the display panel, the output end of the input switch unit is electrically connected to the inverting input end of the inverting amplifier unit, the output end of the inverting amplifier unit is electrically connected to the input end of the inverting integration unit, and the output end of the inverting integration unit is electrically connected to the input end of the data charging switch module; When the polarity reversal signal is a first level signal, the input switch unit is used to transmit the pulse input signal to the inverting amplification unit, and the output end of the inverting integration unit is used to output the positive phase trapezoidal wave signal; When the polarity inversion signal is a second level signal, the input switch unit is used to transmit the inverted signal of the pulse input signal to the inverting amplification unit, and the output end of the inverting integration unit is used to output the inverted trapezoidal wave signal.

3. The pixel driving circuit of the display panel according to claim 2, characterized in that: The input switch unit includes an analog switch and an inverter; The first output end of the analog switch, the output end of the inverter and the inverting input end of the inverting amplifying unit are electrically connected, and the second output end of the analog switch is electrically connected to the input end of the inverter; When the polarity inversion signal is a first level signal, the input end of the analog switch is electrically connected to the first output end of the analog switch; When the polarity inversion signal is a second level signal, the input end of the analog switch is electrically connected to the second output end of the analog switch.

4. The pixel driving circuit of the display panel according to claim 2, characterized in that: The inverting amplifying unit includes: an amplifier, a first resistor, a second resistor and a third resistor; the first end of the first resistor is electrically connected to the output end of the input switching unit, the second end of the first resistor, the inverting input end of the amplifier and the second end of the second resistor are electrically connected, the non-inverting input end of the amplifier is electrically connected to the reference ground of the pixel driving circuit through the third resistor, and the output end of the amplifier, the first end of the second resistor and the input end of the inverting integrating unit are electrically connected.

5. The pixel driving circuit of the display panel according to claim 2, characterized in that: The inverting integration unit comprises: an integrator, a fourth resistor, a fifth resistor and a first capacitor; The first end of the fourth resistor is electrically connected to the output end of the inverting amplification unit, the second end of the fourth resistor, the inverting input end of the integrator, the first end of the first capacitor and the second end of the fifth resistor are electrically connected, the non-inverting input end of the integrator is electrically connected to the reference ground of the pixel driving circuit, and the output end of the integrator, the second end of the first capacitor, the first end of the fifth resistor and the input end of the data charging switch module are electrically connected.

6. The pixel driving circuit of a display panel according to any one of claims 1 to 5, characterized in that: The data charging switch module comprises: a data switch transistor; The first end of the data switch transistor is electrically connected to the output end of the trapezoidal generator module, the second end of the data switch transistor is electrically connected to the pixel through the data line of the display panel, and the control end of the data switch transistor is electrically connected to the output end of the pulse width modulation circuit module.

7. A pixel driving method for a display panel, characterized in that: A pixel driving circuit applied to a display panel according to any one of claims 1 to 6, comprising: Outputting the digital data signal of the display panel through the data buffer; Performing pulse width modulation according to the digital data signal to output a target pulse width signal, and outputting a trapezoidal wave signal according to a pulse input signal and a polarity inversion signal of the display panel; Under the control of the target pulse width signal, outputting a driving voltage signal to pixels in the display panel based on the trapezoidal wave signal; Among them, the pulse width modulation is performed according to the digital data signal to output the target pulse width signal, including: based on the digital data signal, in combination with the charging control information corresponding to the pixel, the pulse duty cycle is adjusted, and the initial pulse width signal is output to the level shifter based on the adjusted pulse duty cycle; through the level shifter, level shifting is performed based on the initial pulse width signal, and the target pulse width signal corresponding to the digital data signal is output.

8. A display panel, characterized in that: The display panel comprises a pixel driving circuit of the display panel according to any one of claims 1 to 6.

9. A display device, characterized in that: include: The display panel and power supply module according to claim 8, wherein the power supply module is used to control the power supply to the display panel.

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