Pixel circuit system, driving method of pixel circuit system and display device

Abstract

The present invention relates to a pixel circuit system, a driving method of the pixel circuit system and a display device. The pixel circuit system comprises: a video processing module, which is used to generate a pixel circuit driving signal according to video source data; a pixel circuit module, which is connected to the video processing module, and is used to separate the high-order signal and the low-order signal in the pixel circuit driving signal, and respectively perform digital-to-analog conversion on the high-order signal and the low-order signal to obtain a high-order voltage value and a low-order voltage value; according to the high-order clock frequency and the low-order clock frequency, the high-order voltage value and the low-order voltage value are respectively compared with the corresponding ramp voltage data, and a high-order pulse width modulation signal corresponding to the high-order voltage value and a low-order pulse width modulation signal corresponding to the low-order voltage value are output. The pixel circuit system can reduce the loss of display grayscale accuracy without increasing the design area and power consumption of the original pixel circuit system.

Description

Technical Field

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

[0002] A pixel circuit system refers to an overall system consisting of multiple pixel circuits. The pixel circuit system is combined with a display device to complete image processing and display. Each pixel circuit controls the brightness and color of a display pixel. With the development of display technology, the design of the pixel circuit system is also constantly improving to achieve higher resolution, lower power consumption and better display effects. The pixel circuit system is limited by the size and accuracy of the pixel circuit, resulting in a loss of grayscale accuracy.

[0003] In the traditional way, the problem of grayscale accuracy loss caused by the limitation of pixel circuit size and accuracy is solved by increasing the pixel circuit size and improving the accuracy of the digital-to-analog conversion module. However, the traditional method will increase the design area of ​​the entire pixel circuit system, increase power consumption, and make the implementation complex. Summary of the invention

[0004] Based on this, it is necessary to provide a pixel circuit system, a driving method of the pixel circuit system and a display device that can reduce the loss of display grayscale accuracy without increasing the design area and power consumption of the original pixel circuit system to address the above technical problems.

[0005] In a first aspect, the present application provides a pixel circuit system, comprising: a video processing module, for generating a pixel circuit drive signal according to video source data; a pixel circuit module, connected to the video processing module, for separating a high-order signal from a low-order signal in the pixel circuit drive signal, performing digital-to-analog conversion on the high-order signal and the low-order signal, respectively, to obtain a high-order voltage value and a low-order voltage value; comparing the high-order voltage value and the low-order voltage value with corresponding ramp voltage data according to a high-order clock frequency and a low-order clock frequency, and outputting a high-order pulse width modulation signal corresponding to the high-order voltage value and a low-order pulse width modulation signal corresponding to the low-order voltage value.

[0006] In one of the embodiments, the video processing module is also used to perform gamma correction on the pixel circuit drive signal to generate a continuous grayscale signal that conforms to human eye vision; the pixel circuit module includes a digital-to-analog conversion unit, which is used to separate the high-order signal and the low-order signal in the continuous grayscale signal, and perform digital-to-analog conversion on the high-order signal and the low-order signal respectively to obtain a high-order voltage value and a low-order voltage value.

[0007] In one embodiment, the pixel circuit module includes: a color separation module, which is used to perform color separation processing on the pixel circuit drive signal to obtain multiple sub-circuit drive signals corresponding to the pixel circuit drive signal; separate the high-order signal and the low-order signal in each sub-circuit drive signal; and perform digital-to-analog conversion on the high-order signal and the low-order signal in each sub-circuit drive signal to obtain the high-order voltage value and the low-order voltage value corresponding to each sub-circuit drive signal.

[0008] In one embodiment, the pixel circuit module includes a pixel circuit, which includes a high-order storage capacitor, a low-order storage capacitor and a comparator; the pixel circuit is used to charge the corresponding high-order storage capacitor according to the high-order voltage value of each sub-circuit drive signal, and to charge the corresponding low-order storage capacitor according to the low-order voltage value corresponding to each sub-circuit drive signal; the high-order storage capacitor and the low-order storage capacitor of the pixel circuit are time-sharingly turned on with the comparator to input the high-order voltage value and the low-order voltage value corresponding to each sub-circuit drive signal into the comparator in a time-sharing manner; the comparator is used to compare the high-order voltage value with the corresponding high-order ramp voltage data according to the high-order clock frequency, and to compare the low-order voltage value with the corresponding low-order ramp voltage data according to the low-order clock frequency.

[0009] In one of the embodiments, the pixel circuit is also used to time-share conduct the high-order storage capacitor and the low-order storage capacitor of the pixel circuit with the first input terminal of the comparator, so as to time-share input the high-order voltage value and the low-order voltage value corresponding to each sub-circuit driving signal to the first input terminal of the comparator; the comparator is also used to compare the high-order voltage value with the high-order slope voltage data of the second input terminal of the comparator according to the high-order clock frequency, and to compare the low-order voltage value with the low-order slope voltage data of the second input terminal of the comparator according to the low-order clock frequency.

[0010] In one embodiment, the pixel circuit module also includes: a power management unit, which is used to provide a comparator of the pixel circuit with high-order ramp voltage data corresponding to the high-order voltage value and low-order ramp voltage data corresponding to the low-order voltage value; a comparator, which is used to compare the high-order voltage value with the corresponding high-order ramp voltage data according to a high-order clock frequency, and when the high-order voltage value is less than the high-order ramp voltage data, output a high-order pulse width modulation signal of a first value, and when the high-order voltage value is greater than or equal to the high-order ramp voltage data, output a high-order pulse width modulation signal of a second value; the comparator is also used to compare the low-order voltage value with the corresponding low-order ramp voltage data according to a low-order clock frequency, and when the low-order voltage value is less than the low-order ramp voltage data, output a low-order pulse width modulation signal of a first value, and when the low-order voltage value is greater than or equal to the low-order ramp voltage data, output a low-order pulse width modulation signal of a second value.

[0011] In one embodiment, the pixel circuit module also includes: a clock management unit, used to provide a high-order clock frequency and a low-order clock frequency for the comparator of the pixel circuit; a power management unit, used to generate high-order slope voltage data corresponding to the high-order voltage value according to the high-order clock frequency, and to generate low-order slope voltage data corresponding to the low-order voltage value according to the low-order clock frequency, and input the high-order slope voltage data and the low-order slope voltage data into the comparator of the pixel circuit; wherein the slope of the high-order slope voltage data matches the high-order clock frequency, and the slope of the low-order slope voltage data matches the low-order clock frequency.

[0012] In one of the embodiments, the pixel circuit module is also used to adopt any one of the following methods when outputting the high-order pulse width modulation signal corresponding to the high-order voltage value and the low-order pulse width modulation signal corresponding to the low-order voltage value: first output the high-order pulse width modulation signal, and then output the low-order pulse width modulation signal; first output the low-order pulse width modulation signal, and then output the high-order pulse width modulation signal; alternately output the high-order pulse width modulation signal and the low-order pulse width modulation signal.

[0013] In a second aspect, the present application also provides a driving method for a pixel circuit system, which is used to drive the pixel circuit system described in any of the above embodiments, including: generating a pixel circuit driving signal based on video source data; separating the high-order signal and the low-order signal in the pixel circuit driving signal, and performing digital-to-analog conversion on the high-order signal and the low-order signal respectively to obtain a high-order voltage value and a low-order voltage value; comparing the high-order voltage value and the low-order voltage value with corresponding ramp voltage data according to a high-order clock frequency and a low-order clock frequency, and outputting a high-order pulse width modulation signal corresponding to the high-order voltage value and a low-order pulse width modulation signal corresponding to the low-order voltage value.

[0014] In a third aspect, the present application also provides a display device, comprising the pixel circuit system described in any of the above embodiments.

[0015] The pixel circuit system, the driving method of the pixel circuit system and the display device, the pixel circuit module in the pixel circuit system divides the pixel circuit driving signal into a high signal and a low signal, and converts the high signal and the low signal into a high voltage value and a low voltage value respectively, and then compares the high voltage value and the low voltage value with the corresponding ramp voltage data at different clock frequencies, and outputs the corresponding pulse width modulation signal. By generating pulse width modulation signals corresponding to the high voltage value and the low voltage value respectively at different clock frequencies, the pulse width modulation signals corresponding to the high voltage value and the low voltage value have different precisions, and more signal bits can be retained, so that the loss of display grayscale accuracy (grayscale loss) is reduced without increasing the design area and power consumption of the original pixel circuit system, the display grayscale level is improved, and the display resolution is improved, so that the color of the displayed picture is more realistic and the picture is more delicate. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 is a schematic diagram of a pixel circuit system in one embodiment;

[0018] Figure 2 is a schematic diagram of a pixel circuit system in another embodiment;

[0019] Figure 3 is a schematic structural diagram of a pixel circuit in one embodiment;

[0020] Figure 4 is a working principle diagram of a pixel circuit in one embodiment;

[0021] Figure 5 is a clock frequency diagram of a comparator in one embodiment;

[0022] Figure 6 is a principle block diagram of a pixel circuit system in one embodiment;

[0023] Figure 7 is a schematic diagram of a cycle of four pulse width modulation signals of a pixel circuit system in one embodiment;

[0024] Figure 8 A schematic diagram of grayscale loss comparison between a conventional pixel circuit system and a pixel circuit system of the present application in one embodiment;

[0025] Fig. 9FIG. 4 is a flow chart of a driving method of a pixel circuit system in an embodiment.

[0026] Explanation of the reference numerals: 100, video processing module; 200, pixel circuit module; 201, digital-to-analog conversion unit; 202, pixel circuit; 203, power management unit; 204, clock management unit. DETAILED DESCRIPTION

[0027] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0029] It is understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0030] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0031] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.

[0032] In an exemplary embodiment, Figure 1As shown, it is a schematic diagram of a pixel circuit system, and the pixel circuit module 200 includes a video processing module 100 and a pixel circuit module 200. The video processing module 100 is used to generate a pixel circuit driving signal according to video source data. The pixel circuit module 200 is connected to the video processing module 100, and is used to separate the high-order signal and the low-order signal in the pixel circuit driving signal, and perform digital-to-analog conversion on the high-order signal and the low-order signal respectively to obtain a high-order voltage value and a low-order voltage value; according to the high-order clock frequency and the low-order clock frequency, the high-order voltage value and the low-order voltage value are compared with the corresponding ramp voltage data respectively, and a high-order pulse width modulation signal corresponding to the high-order voltage value and a low-order pulse width modulation signal corresponding to the low-order voltage value are output.

[0033] The video source data is the raw data of the video signal, which contains the continuous sampling of each frame of the image in time. The video source data can be an unprocessed data stream obtained from a camera, a video capture card or other video source device. The pixel circuit drive signal refers to the control signal used to drive the pixel circuit. The high-bit clock frequency and the low-bit clock frequency refer to the working clock frequency.

[0034] Specifically, the video processing module 100 obtains video source data, and generates a data format and a control signal for driving a pixel circuit according to the video source data, wherein the control signal is a pixel circuit driving signal. The data format for driving a pixel circuit can be determined according to actual needs, for example, the data format can include but is not limited to a digital video interface, a video serial interface, a high-definition multimedia interface, and a digital display interface.

[0035] The pixel circuit module 200 is connected to the output end of the video processing module 100, and is used to separate the high-order signal and the low-order signal in the pixel circuit drive signal. Among them, the high-order signal refers to the signal at the front position, and the low-order signal refers to the signal at the back position. The number of bits of the high-order signal and the low-order signal can be determined according to the number of bits that the pixel circuit module 200 can process. The number of bits of the high-order signal and the low-order signal cannot exceed the maximum number of bits that the pixel circuit module 200 can process. For example, the number of bits of the high-order signal and the low-order signal can be the same or different. The pixel circuit module 200 is also used to perform digital-to-analog conversion on the high-order signal to obtain a high-order voltage value. Perform digital-to-analog conversion on the low-order signal to obtain a low-order voltage value.

[0036] The slope voltage data corresponding to the high-order voltage value is the high-order slope voltage data, and the slope voltage data corresponding to the low-order voltage value is the low-order slope voltage data. The pixel circuit module 200 is used to compare the high-order voltage value with the corresponding high-order slope voltage data according to the high-order clock frequency, and output the high-order pulse width modulation signal corresponding to the high-order voltage value according to the comparison result. It is also used to compare the low-order voltage value with the corresponding low-order slope voltage data according to the low-order clock frequency, and output the low-order pulse width modulation signal corresponding to the low-order voltage value according to the comparison result. Among them, the high-order clock frequency is different from the low-order clock frequency, and further, the high-order clock frequency is lower than the low-order clock frequency. By setting different high-order clock frequencies and low-order clock frequencies, the high-order voltage value and the low-order voltage value are processed respectively, and high-order pulse width modulation signals and low-order pulse width modulation signals with different precisions can be generated.

[0037] In this embodiment, the pixel circuit module in the pixel circuit system divides the pixel circuit driving signal into a high-order signal and a low-order signal, and converts the high-order signal and the low-order signal into a high-order voltage value and a low-order voltage value, respectively. After that, the high-order voltage value and the low-order voltage value are compared with the corresponding ramp voltage data at different clock frequencies, and the corresponding pulse width modulation signal is output. By generating pulse width modulation signals corresponding to the high-order voltage value and the low-order voltage value at different clock frequencies, the pulse width modulation signals corresponding to the high-order voltage value and the low-order voltage value have different precisions, and more signal bits can be retained, so that the display grayscale accuracy loss (grayscale loss) is reduced without increasing the design area and power consumption of the original pixel circuit system, the display grayscale level is improved, and the display resolution is improved, so that the color of the displayed picture is more realistic and the picture is more delicate.

[0038] In an exemplary embodiment, the video processing module 100 is also used to perform gamma correction on the pixel circuit driving signal to generate a continuous grayscale signal that conforms to human eye vision; the pixel circuit module 200 includes a digital-to-analog conversion unit, which is used to separate the high-order signal and the low-order signal in the continuous grayscale signal, and perform digital-to-analog conversion on the high-order signal and the low-order signal respectively to obtain a high-order voltage value and a low-order voltage value.

[0039] Specifically, the video processing module 100 is used to perform gamma correction (gamma correction) on the pixel circuit driving signal to generate a continuous grayscale signal that conforms to human vision. For example, the gamma value of the gamma correction can be 2.2. The number of bits of the high-order signal and the low-order signal can be determined according to the maximum number of bits that the digital-to-analog conversion unit in the pixel circuit module 200 can process, and the number of bits of the high-order signal or the low-order signal cannot exceed the maximum number of bits that the digital-to-analog conversion unit can process. Therefore, the digital-to-analog conversion unit is used to separate the high-order signal and the low-order signal in the continuous grayscale signal according to the maximum number of bits that it can process. For example, if the data bit width (number of bits) of the continuous grayscale signal after gamma correction is n bits, the digital-to-analog conversion unit is used to separate the high-order signal and the low-order signal in the continuous grayscale signal, and the obtained low-order signal is m bits, and the high-order signal is nm bits. The digital-to-analog conversion unit is also used to perform digital-to-analog conversion on the high-order signal and the low-order signal, respectively, to obtain a high-order voltage value and a low-order voltage value.

[0040] In this embodiment, the video processing module performs gamma correction on the pixel circuit driving signal, and can perform nonlinear transformation on the brightness of the pixel circuit driving signal, so that the signal is more consistent with human vision when displayed.

[0041] The digital-to-analog conversion unit separates the high-bit signal and the low-bit signal in the continuous grayscale signal and performs digital-to-analog conversion. By converting the digital signal into an analog voltage, it can drive the pixel circuit system to adjust the display resolution.

[0042] In an exemplary embodiment, the pixel circuit module 200 includes: a color separation module, which is used to perform color separation processing on the pixel circuit driving signal to obtain multiple sub-circuit driving signals corresponding to the pixel circuit driving signal; separate the high-order signal and the low-order signal in each sub-circuit driving signal; and perform digital-to-analog conversion on the high-order signal and the low-order signal in each sub-circuit driving signal to obtain the high-order voltage value and the low-order voltage value corresponding to each sub-circuit driving signal.

[0043] Specifically, the pixel circuit driving signal received by the pixel circuit module 200 is an RGB (Red, Green, Blue) signal. The color separation module in the pixel circuit module 200 processes the three colors of red, green and blue in the RGB signal separately, and each color corresponds to a sub-circuit driving signal. Signal processing is performed for each sub-circuit driving signal to obtain the high-order voltage value and the low-order voltage value corresponding to each sub-circuit driving signal, and a high-order pulse width modulation signal and a low-order pulse width modulation signal corresponding to each sub-circuit driving signal are generated. Further, for each sub-circuit driving signal, the high-order signal and the low-order signal are separated, and the high-order signal and the low-order signal are respectively converted into digital analog to obtain the high-order voltage value and the low-order voltage value corresponding to each sub-circuit driving signal.

[0044] In this embodiment, the pixel circuit driving signal is RGB data, and the data of three colors are received simultaneously. The color separation module is used to perform color separation processing on the pixel circuit driving signal to obtain multiple sub-circuit driving signals. The high and low bits of each sub-circuit driving signal are processed separately and converted into digital-to-analog format, which can make the displayed image color more realistic.

[0045] In an exemplary embodiment, Figure 2 As shown, it is a schematic diagram of a pixel circuit system, the pixel circuit module 200 includes a pixel circuit 202, the pixel circuit 202 includes a high-order storage capacitor, a low-order storage capacitor and a comparator; the pixel circuit 202 is used to charge the corresponding high-order storage capacitor according to the high-order voltage value of each sub-circuit driving signal, and to charge the corresponding low-order storage capacitor according to the low-order voltage value corresponding to each sub-circuit driving signal; the high-order storage capacitor and the low-order storage capacitor of the pixel circuit 202 are time-sharingly turned on with the comparator, so as to input the high-order voltage value and the low-order voltage value corresponding to each sub-circuit driving signal into the comparator in a time-sharing manner; the comparator is used to compare the high-order voltage value with the corresponding high-order ramp voltage data according to the high-order clock frequency, and to compare the low-order voltage value with the corresponding low-order ramp voltage data according to the low-order clock frequency.

[0046] The high-order storage capacitor and the low-order storage capacitor are storage capacitors corresponding to the high-order voltage value and the low-order voltage value, respectively.

[0047] Specifically, the types of the pixel circuit 202 in this embodiment may include, but are not limited to, a liquid crystal type, an LED (Light Emitting Diode) type, an OLED (Organic Light Emitting Diode) type, a micro LED (micro Light Emitting Diode) type, and a Q-LED (Quantum Dot light Emitting Diode). An LED type pixel circuit is used as an example for illustration. Figure 3 , which is a schematic diagram of the structure of the pixel circuit 202, the pixel circuit 202 includes multiple channels, an R channel, a G channel and a B channel. Each channel includes a high-order storage capacitor, a low-order storage capacitor and a comparator for processing the corresponding sub-circuit drive signal. The signal processing method of multiple channels is the same.

[0048] The R channel receives the high voltage value V_high_R and the low voltage value V_low_R of the sub-circuit drive signal corresponding to red. The high storage capacitor C_high_R is charged according to the high voltage value V_high_R, and the low storage capacitor C_low_R is charged according to the low voltage value V_low_R. The high storage capacitor C_high_R and the low storage capacitor C_low_R are time-sharingly turned on with the comparator of the R channel, so that the high voltage value V_high_R and the low voltage value V_low_R of the sub-circuit drive signal corresponding to red are time-sharingly input to the comparator of the R channel. The comparator of the R channel is used to compare the high voltage value V_high_R with the corresponding high ramp voltage data V_RAMP_high according to the high clock frequency, and output the high pulse width modulation signal PWM_high_R according to the comparison result, and compare the low voltage value V_low_R with the corresponding low ramp voltage data V_RAMP_low according to the low clock frequency, and output the low pulse width modulation signal PWM_low_R according to the comparison result, and light up the red LED lamp according to the high pulse width modulation signal PWM_high_R and the low pulse width modulation signal PWM_low_R.

[0049] At the same time, the G channel receives the high voltage value V_high_G and the low voltage value V_low_G of the sub-circuit driving signal corresponding to green, charges the corresponding high storage capacitor C_high_G and the low storage capacitor C_low_G respectively, and time-sharingly conducts the high storage capacitor C_high_G and the low storage capacitor C_low_G with the comparator of the G channel, so as to time-sharingly input the high voltage value V_high_G and the low voltage value V_low_G of the sub-circuit driving signal corresponding to green to the comparator of the G channel. The comparator of the G channel is used to compare the high voltage value V_high_G with the high ramp voltage data V_RAMP_high according to the high clock frequency, and output the high pulse width modulation signal PWM_high_G according to the comparison result, and compare the low voltage value V_low_G with the low ramp voltage data V_RAMP_low according to the low clock frequency, and output the low pulse width modulation signal PWM_low_G according to the comparison result, and light up the green LED lamp according to the high pulse width modulation signal PWM_high_G and the low pulse width modulation signal PWM_low_G.

[0050] At the same time, channel B receives the high voltage value V_high_B and the low voltage value V_low_B of the sub-circuit driving signal corresponding to blue, charges the corresponding high storage capacitor C_high_B and the low storage capacitor C_low_B respectively, and time-sharingly conducts the high storage capacitor C_high_B and the low storage capacitor C_low_B with the comparator of channel B, so as to input the high voltage value V_high_B and the low voltage value V_low_B of the sub-circuit driving signal corresponding to blue to the comparator of channel B in a time-sharing manner. The comparator of channel B is used to compare the high voltage value V_high_B with the high ramp voltage data V_RAMP_high according to the high clock frequency, and output the high pulse width modulation signal PWM_high_B according to the comparison result, and compare the low voltage value V_low_B with the low ramp voltage data V_RAMP_low according to the low clock frequency, and output the low pulse width modulation signal PWM_low_B according to the comparison result, and light up the blue LED lamp according to the high pulse width modulation signal PWM_high_B and the low pulse width modulation signal PWM_low_B.

[0051] In this embodiment, the corresponding storage capacitor is charged according to the high voltage value and the low voltage value of each sub-circuit driving signal, and then is turned on with the comparator in a time-sharing manner, so that the comparator receives the high voltage value and the low voltage value according to different preset clock frequencies, and generates pulse width modulation signals with different precisions, thereby reducing the loss of display grayscale precision (grayscale loss) without increasing the design area and power consumption of the original pixel circuit system, improving the display grayscale level, and improving the display resolution, so that the display color is more realistic and the picture is more delicate.

[0052] In an exemplary embodiment, the pixel circuit 202 is also used to time-share conduct the high-order storage capacitor and the low-order storage capacitor of the pixel circuit 202 with the first input terminal of the comparator, so as to time-share input the high-order voltage value and the low-order voltage value corresponding to each sub-circuit driving signal to the first input terminal of the comparator; the comparator is also used to compare the high-order voltage value with the high-order slope voltage data of the second input terminal of the comparator according to the high-order clock frequency, and to compare the low-order voltage value with the low-order slope voltage data of the second input terminal of the comparator according to the low-order clock frequency.

[0053] Specifically, the comparator includes two input terminals, a first input terminal and a second input terminal. Figure 3 , when the first input terminal of the comparator is the “-” terminal, the second input terminal is the “+” terminal.

[0054] The pixel circuit 202 is further used to time-share conduct the high-order storage capacitor and the low-order storage capacitor of the pixel circuit 202 with the first input terminal of the comparator. The comparator is used to receive a high-order voltage value according to a high-order clock frequency, compare the high-order voltage value with the high-order ramp voltage data of the second input terminal of the comparator, and receive a low-order voltage value according to a low-order clock frequency, and compare the low-order voltage value with the low-order ramp voltage data of the second input terminal of the comparator.

[0055] Furthermore, the order of the two input terminals of the comparator can be interchanged, and the level of the output pulse width modulation signal is also opposite. When the first input terminal is the "+" terminal, the second input terminal is the "-" terminal.

[0056] In this embodiment, the magnitude relationship between the high-bit voltage value and the low-bit voltage value and the corresponding ramp voltage data can be accurately and quickly compared through the two input terminals of the comparator, so as to accurately and quickly output the pulse width modulation signal.

[0057] In an exemplary embodiment, the pixel circuit module 200 also includes: a power management unit, which is used to provide a comparator of the pixel circuit with high-order ramp voltage data corresponding to the high-order voltage value and low-order ramp voltage data corresponding to the low-order voltage value; a comparator, which is used to compare the high-order voltage value with the corresponding high-order ramp voltage data according to a high-order clock frequency, and when the high-order voltage value is less than the high-order ramp voltage data, output a high-order pulse width modulation signal of a first value, and when the high-order voltage value is greater than or equal to the high-order ramp voltage data, output a high-order pulse width modulation signal of a second value; the comparator is also used to compare the low-order voltage value with the corresponding low-order ramp voltage data according to a low-order clock frequency, and when the low-order voltage value is less than the low-order ramp voltage data, output a low-order pulse width modulation signal of a first value, and when the low-order voltage value is greater than or equal to the low-order ramp voltage data, output a low-order pulse width modulation signal of a second value.

[0058] Specifically, the voltage management unit is used to provide the high-order ramp voltage data V_RAMP_high and the low-order ramp voltage data V_RAMP_low to the comparator of the pixel circuit. The comparator is used to receive the high-order voltage value V_high according to the high-order clock frequency, compare the high-order voltage value V_high with the corresponding high-order ramp voltage data V_RAMP_high, and when the high-order voltage value V_high is less than the high-order ramp voltage data V_RAMP_high, the comparator outputs 1. When the high-order voltage value V_high is greater than or equal to the high-order ramp voltage data V_RAMP_high, the comparator outputs 0.

[0059] The operation of the low voltage value is similar. When the low voltage value V_low is less than the low ramp voltage data V_RAMP_low, the comparator outputs 1. When the low voltage value V_low is greater than or equal to the low ramp voltage data V_RAMP_low, the comparator outputs 0.

[0060] Among them, the high-order ramp voltage data V_RAMP_high and the low-order ramp voltage data V_RAMP_low are voltage curves from 0 to V_max, such as Figure 4 As shown in the figure, it is a working principle diagram of the pixel circuit. Assume that the high voltage value V_high and the low voltage value V_low output by the digital-to-analog conversion unit are equal, compare the high voltage value V_high and the low voltage value V_low with the high ramp voltage data V_RAMP_high and the low ramp voltage data V_RAMP_low respectively, and output the high pulse width modulation signal PWM_high and the low pulse width modulation signal PWM_low.

[0061] In this embodiment, the comparator can accurately and quickly compare the magnitude relationship between the high voltage value and the low voltage value and the corresponding slope voltage curve, thereby accurately and quickly outputting the pulse width modulation signal.

[0062] In an exemplary embodiment, the pixel circuit module 200 also includes: a clock management unit, which is used to provide a high-order clock frequency and a low-order clock frequency for the comparator of the pixel circuit; a power management unit, which is used to generate high-order slope voltage data corresponding to the high-order voltage value according to the high-order clock frequency, and generate low-order slope voltage data corresponding to the low-order voltage value according to the low-order clock frequency, and send the high-order slope voltage data and the low-order slope voltage data to the comparator of the pixel circuit corresponding to each type of circuit driving signal; wherein the slope of the high-order slope voltage data matches the high-order clock frequency, and the slope of the low-order slope voltage data matches the low-order clock frequency.

[0063] Specifically, the clock management unit is used to provide a high-bit clock frequency and a low-bit clock frequency to the comparator. The power management unit is used to generate high-bit ramp voltage data corresponding to the high-bit voltage value according to the high-bit clock frequency, and generate low-bit ramp voltage data corresponding to the low-bit voltage value according to the low-bit clock frequency, and input the high-bit ramp voltage data and the low-bit ramp voltage data to the comparator of the pixel circuit.

[0064] Both the high-order ramp voltage data and the low-order ramp voltage data are voltage curves that increase linearly from 0 to VDD (power supply voltage) at a certain slope, but the growth slopes of the high-order ramp voltage data and the low-order ramp voltage data are different, and their slopes match the clock video.

[0065] Furthermore, the clock frequency of the comparator under the high-order signal nm bit is F, then the clock frequency of the comparator under the low-order signal m bit is F×2 m , the comparator clock frequency diagram is as follows Figure 5 shown.

[0066] In this embodiment, the clock management unit provides different high-order clock frequencies and low-order clock frequencies for the comparator of the pixel circuit, and the power management unit generates corresponding ramp voltage data according to the high-order clock frequency and the low-order clock frequency, and inputs the data into the comparator, so that the comparator is configured to receive high-order signals and low-order signals at different clock frequencies, and compare the signals with the corresponding ramp voltage data, so as to generate pulse width modulation signals with different precisions, thereby reducing the loss of grayscale precision (grayscale loss) of the display without increasing the design area and power consumption of the original pixel circuit system, improving the display grayscale level, and improving the display resolution, so that the display color is more realistic and the picture is more delicate.

[0067] In an exemplary embodiment, within a frame period, a pulse width modulation signal should be cyclically generated for each pixel circuit. For a high voltage value, a high pulse width modulation signal can be cyclically generated a times, and the corresponding comparator clock frequency is doubled a times. For a low voltage value, b low pulse width modulation signals can be cyclically generated b times, and the corresponding comparator clock frequency is doubled b times, where a≥1, b≥1. a and b can be set according to actual needs, and the larger the better within the range that the comparator can achieve.

[0068] In an exemplary embodiment, the pixel circuit module 200 is also used to adopt any of the following methods when outputting a high-order pulse width modulation signal corresponding to a high-order voltage value and a low-order pulse width modulation signal corresponding to a low-order voltage value: first outputting a high-order pulse width modulation signal and then outputting a low-order pulse width modulation signal; first outputting a low-order pulse width modulation signal and then outputting a high-order pulse width modulation signal; alternately outputting a high-order pulse width modulation signal and a low-order pulse width modulation signal.

[0069] Specifically, within one frame period, for the high-order pulse width modulation signal and the low-order pulse width modulation signal generated by each pixel circuit, when outputting to light up the display material, a high-order pulse width modulation signal may be output first, and then b low-order pulse width modulation signals may be output; or b low-order pulse width modulation signals may be output first, and then a high-order pulse width modulation signal may be output; or high-order pulse width modulation signals and low-order pulse width modulation signals may be output alternately to reduce flickering.

[0070] In this embodiment, by setting a plurality of output modes of high-bit pulse width modulation signals and low-bit pulse width modulation signals, flexible selection of the lighting mode of the display material is achieved.

[0071] In an exemplary embodiment, Figure 6As shown, it is a principle block diagram of a pixel circuit system. In this embodiment, an LED type pixel circuit is taken as an example. The pixel circuit system includes a video processing module 100 and a pixel circuit module 200. The pixel circuit module 200 includes a digital-to-analog conversion unit 201, a pixel circuit 202, a power management unit 203, and a clock management unit 204. The control signal represents a pixel circuit drive signal, and the pixel circuit drive signal includes a row selection signal and a column drive signal. Pixel circuit_R, pixel circuit_G, and pixel circuit_B can represent the R pixel, G pixel, and B pixel of the pixel circuit, that is, the R channel, the G channel, and the B channel. The pixel circuit includes a plurality of row pixels and a plurality of column pixels, and each row of pixels is arranged in the order of R pixel, G pixel, and B pixel from left to right, and each column of pixels is a single pixel. The row selection signal is used to select the row pixel receiving data. The multiple column drivers are independent of each other, and the column drivers are used to provide high-order ramp voltage data, low-order ramp voltage data, high-order clock frequency and low-order clock frequency, high-order voltage value and low-order voltage value for the column pixels in each row of pixels to control the color and grayscale of the LED type pixel circuit.

[0072] Exemplarily, taking the video source data with 8-bit grayscale depth as an example, after gamma correction, 12-bit accuracy is retained, the high and low bits are separated, and each 6 bits is processed subsequently. Taking the R channel as an example, the high-order signal and the low-order signal are converted into analog voltages V_high_R and V_low_R after passing through the digital-to-analog conversion unit 201. Among them, during the digital-to-analog conversion, the high-order signal and the low-order signal need to be converted according to the same weight. The range of the high-order ramp voltage data V_RAMP_high and the low-order ramp voltage data V_RAMP_low are both 0~5V. Within 1 frame, the high-order voltage value PWM_high and the low-order voltage value PWM_low are generated 4 times in a cycle, namely PWM_low_1, PWM_low_2, PWM_low_3, PWM_low_4 and PWM_high_1, PWM_high_2, PWM_high_3, PWM_high_4, respectively. Low is effective, such as Figure 7 As shown in FIG. 1 , it is a schematic diagram of the cycle of the four pulse width modulation signals of the pixel circuit system. The final output signal for lighting the LED lamp is the alternating signal: PWM_high_1, PWM_low_1, PWM_high_2, PWM_low_2, PWM_high_3, PWM_low_3, PWM_high_4, PWM_low_4. The same processing is performed for the G channel and the B channel according to the above processing process.

[0073] like Figure 8The figure shows a comparison diagram of grayscale loss between a conventional pixel circuit system and the pixel circuit system of the present application. In the conventional method, after gamma2.2 correction, the original 256 grayscales can only display 8-bit grayscale accuracy, and 72 grayscales will be lost. However, the pixel circuit system designed by the present application can display 12-bit grayscale accuracy, and only 7 grayscales will be lost in the final output. This reduces the loss of grayscale accuracy (grayscale loss) and improves the grayscale level of the system display without increasing the design area and power consumption of the original pixel circuit system, achieving a more realistic color display and a more delicate display effect.

[0074] In an exemplary embodiment, Fig. 9 As shown, a method for driving a pixel circuit system is provided, which is used to drive the pixel circuit system in any of the above embodiments, and the method comprises the following steps:

[0075] Step 902: Generate a pixel circuit driving signal according to video source data.

[0076] Step 904 , separate the high-order signal and the low-order signal in the pixel circuit driving signal, perform digital-to-analog conversion on the high-order signal and the low-order signal, respectively, to obtain a high-order voltage value and a low-order voltage value.

[0077] Step 906, comparing the high voltage value and the low voltage value with the corresponding ramp voltage data according to the high clock frequency and the low clock frequency, and outputting a high pulse width modulation signal corresponding to the high voltage value and a low pulse width modulation signal corresponding to the low voltage value.

[0078] In this embodiment, the pixel circuit driving signal is divided into a high-order signal and a low-order signal, and the high-order signal and the low-order signal are converted into a high-order voltage value and a low-order voltage value respectively. After that, the high-order voltage value and the low-order voltage value are compared with the corresponding ramp voltage data at different clock frequencies, and the corresponding pulse width modulation signal is output. By generating pulse width modulation signals corresponding to the high-order voltage value and the low-order voltage value respectively at different clock frequencies, the precision of the pulse width modulation signals corresponding to the high-order voltage value and the low-order voltage value is different, and more signal bits can be retained, so that the loss of grayscale accuracy (grayscale loss) is reduced without increasing the design area and power consumption of the original pixel circuit system, the grayscale level of display is improved, and the display resolution is improved, so that the color of the displayed picture is more realistic and the picture is more delicate.

[0079] In an exemplary embodiment, a display device is provided, comprising the pixel circuit system in any one of the above embodiments.

[0080] In the description of this specification, the description with reference to the terms "some embodiments", "other embodiments", "ideal embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0081] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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.

[0082] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention application. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A pixel circuit system, characterized in that: include: A video processing module, used for generating a pixel circuit driving signal according to video source data; A pixel circuit module, connected to the video processing module, for separating a high-bit signal from a low-bit signal in the pixel circuit driving signal, performing digital-to-analog conversion on the high-bit signal and the low-bit signal, respectively, to obtain a high-bit voltage value and a low-bit voltage value; According to the high-order clock frequency and the low-order clock frequency, the high-order voltage value and the low-order voltage value are respectively compared with the corresponding ramp voltage data, and a high-order pulse width modulation signal corresponding to the high-order voltage value and a low-order pulse width modulation signal corresponding to the low-order voltage value are output; The pixel circuit module includes a color separation module and a pixel circuit, and the pixel circuit includes a high-bit storage capacitor, a low-bit storage capacitor and a comparator; A color separation module is used to perform color separation processing on the pixel circuit driving signal to obtain multiple sub-circuit driving signals corresponding to the pixel circuit driving signal; separate the high-order signal and the low-order signal in each sub-circuit driving signal; perform digital-to-analog conversion on the high-order signal and the low-order signal in each sub-circuit driving signal to obtain a high-order voltage value and a low-order voltage value corresponding to each sub-circuit driving signal; A pixel circuit, used for charging a corresponding high-order storage capacitor according to a high-order voltage value of each sub-circuit driving signal, and charging a corresponding low-order storage capacitor according to a low-order voltage value corresponding to each sub-circuit driving signal; the high-order storage capacitor and the low-order storage capacitor of the pixel circuit are time-sharingly connected with a comparator, so as to input the high-order voltage value and the low-order voltage value corresponding to each sub-circuit driving signal to the comparator in a time-sharing manner; The comparator is used to compare the high-bit voltage value with the corresponding high-bit ramp voltage data according to the high-bit clock frequency, and to compare the low-bit voltage value with the corresponding low-bit ramp voltage data according to the low-bit clock frequency.

2. The pixel circuit system according to claim 1, characterized in that: The video processing module is also used to perform gamma correction on the pixel circuit driving signal to generate a continuous grayscale signal that conforms to human vision; The pixel circuit module includes a digital-to-analog conversion unit, which is used to separate the high-bit signal and the low-bit signal in the continuous grayscale signal, and perform digital-to-analog conversion on the high-bit signal and the low-bit signal respectively to obtain a high-bit voltage value and a low-bit voltage value.

3. The pixel circuit system according to claim 1, characterized in that: The pixel circuit is further used to conduct the high-order storage capacitor and the low-order storage capacitor of the pixel circuit with the first input terminal of the comparator in a time-sharing manner, so as to input the high-order voltage value and the low-order voltage value corresponding to each sub-circuit driving signal to the first input terminal of the comparator in a time-sharing manner; The comparator is also used to compare the high voltage value with the high slope voltage data of the second input terminal of the comparator according to the high clock frequency, and to compare the low voltage value with the low slope voltage data of the second input terminal of the comparator according to the low clock frequency.

4. The pixel circuit system according to claim 1, characterized in that: The pixel circuit module further includes: A power management unit, used for providing a comparator of the pixel circuit with high-bit ramp voltage data corresponding to a high-bit voltage value and low-bit ramp voltage data corresponding to a low-bit voltage value; A comparator, used for comparing a high-bit voltage value with corresponding high-bit ramp voltage data according to a high-bit clock frequency, and outputting a high-bit pulse width modulation signal of a first value when the high-bit voltage value is less than the high-bit ramp voltage data, and outputting a high-bit pulse width modulation signal of a second value when the high-bit voltage value is greater than or equal to the high-bit ramp voltage data; The comparator is also used to compare the low-order voltage value with the corresponding low-order ramp voltage data according to the low-order clock frequency, and when the low-order voltage value is less than the low-order ramp voltage data, output a low-order pulse width modulation signal of a first value, and when the low-order voltage value is greater than or equal to the low-order ramp voltage data, output a low-order pulse width modulation signal of a second value.

5. The pixel circuit system according to claim 4, characterized in that: The pixel circuit module further includes: A clock management unit, used for providing a high-bit clock frequency and a low-bit clock frequency for a comparator of a pixel circuit; A power management unit is used to generate high-order ramp voltage data corresponding to a high-order voltage value according to a high-order clock frequency, and to generate low-order ramp voltage data corresponding to a low-order voltage value according to a low-order clock frequency, and to input the high-order ramp voltage data and the low-order ramp voltage data into a comparator of a pixel circuit; wherein the slope of the high-order ramp voltage data matches the high-order clock frequency, and the slope of the low-order ramp voltage data matches the low-order clock frequency.

6. The pixel circuit system according to claim 1, characterized in that: The pixel circuit module is further configured to adopt any one of the following methods when outputting a high-bit pulse width modulation signal corresponding to the high-bit voltage value and a low-bit pulse width modulation signal corresponding to the low-bit voltage value: Firstly output the high-bit pulse width modulation signal, and then output the low-bit pulse width modulation signal; Firstly output the low-bit pulse width modulation signal, and then output the high-bit pulse width modulation signal; The high-bit pulse width modulation signal and the low-bit pulse width modulation signal are output alternately.

7. A driving method of a pixel circuit system, characterized in that: For driving the pixel circuit system according to any one of claims 1 to 6, the method comprises the following steps: Generate a pixel circuit driving signal according to video source data; Separating a high-order signal from a low-order signal in the pixel circuit driving signal, and performing digital-to-analog conversion on the high-order signal and the low-order signal to obtain a high-order voltage value and a low-order voltage value; According to the high-order clock frequency and the low-order clock frequency, the high-order voltage value and the low-order voltage value are respectively compared with the corresponding ramp voltage data, and a high-order pulse width modulation signal corresponding to the high-order voltage value and a low-order pulse width modulation signal corresponding to the low-order voltage value are output; Performing color separation processing on the pixel circuit driving signal to obtain a plurality of sub-circuit driving signals corresponding to the pixel circuit driving signal; separating the high-order signal and the low-order signal in each sub-circuit driving signal; performing digital-to-analog conversion on the high-order signal and the low-order signal in each sub-circuit driving signal to obtain a high-order voltage value and a low-order voltage value corresponding to each sub-circuit driving signal; The corresponding high-order storage capacitor is charged according to the high-order voltage value of each sub-circuit driving signal, and the corresponding low-order storage capacitor is charged according to the low-order voltage value corresponding to each sub-circuit driving signal; the high-order storage capacitor and the low-order storage capacitor of the pixel circuit are time-sharingly connected with the comparator to input the high-order voltage value and the low-order voltage value corresponding to each sub-circuit driving signal to the comparator in a time-sharing manner; The comparator compares the high-bit voltage value with the corresponding high-bit ramp voltage data according to the high-bit clock frequency, and compares the low-bit voltage value with the corresponding low-bit ramp voltage data according to the low-bit clock frequency.

8. The driving method of the pixel circuit system according to claim 7, characterized in that: The step of separating the high-order signal and the low-order signal in the pixel circuit driving signal, performing digital-to-analog conversion on the high-order signal and the low-order signal respectively to obtain a high-order voltage value and a low-order voltage value comprises: Performing gamma correction on the pixel circuit driving signal to generate a continuous grayscale signal that conforms to human vision; The high-bit signal and the low-bit signal in the continuous grayscale signal are separated, and the high-bit signal and the low-bit signal are respectively converted into digital-to-analog form to obtain a high-bit voltage value and a low-bit voltage value.

9. The driving method of the pixel circuit system according to claim 7, characterized in that: When outputting the high-bit pulse width modulation signal corresponding to the high-bit voltage value and the low-bit pulse width modulation signal corresponding to the low-bit voltage value, any one of the following methods is adopted: Firstly output the high-bit pulse width modulation signal, and then output the low-bit pulse width modulation signal; Firstly output the low-bit pulse width modulation signal, and then output the high-bit pulse width modulation signal; The high-bit pulse width modulation signal and the low-bit pulse width modulation signal are output alternately.

10. A display device, characterized in that: A pixel circuit system comprising any one of claims 1-6.

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