Pixel circuit for improving low-gray-scale display effect and control method thereof
By introducing different switching tubes to connect to reset signals in the R, G, and B pixel driving circuits, controlling the OLED anode reset voltage, the crosstalk color casting problem in low grayscale of silicon-based OLED products is solved, and the display effect is improved.
Patent Information
- Application Number
- CN202411964195.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-30
- Publication Date
- 2025-07-08
AI Technical Summary
At low grayscale, traditional silicon-based OLED products cause crosstalk color cast due to crosstalk leakage between R/G/B pixels, which affects the display effect.
The R, G, and B pixel driving circuits are designed, and they are connected to the pixel reset signal through different switching tubes to control the anode reset voltage of the pixel OLED to reduce the influence of lateral leakage current.
Improves the low grayscale display effect, reduces crosstalk between pixels, and improves display contrast.
Smart Images
Figure CN120279839A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of OLED display, and particularly to a pixel circuit for improving the display effect of low gray levels and a control method thereof. Background Art
[0002] In recent years, with the continuous development of electronic technology, electronic display devices have become an indispensable tool in people's lives. With the upgrading of electronic display devices, consumers' requirements for them are getting higher and higher. Especially in the field of intelligent electronics, the requirements for the image resolution, color saturation, and display effect of low gray levels of various electronic display devices are also getting higher and higher.
[0003] Currently, due to the existence of horizontal leakage current between R / G / B pixels in traditional silicon-based OLED products, there is a phenomenon of crosstalk color deviation in general at low gray levels, which seriously affects the display effect of the whole machine in the low gray level state. Summary of the Invention
[0004] The purpose of the present application is to provide a pixel circuit for improving the display effect of low gray levels and a control method thereof, which reduces the influence of horizontal leakage current between pixels on the display effect of the product and improves the display effect of low gray levels.
[0005] To achieve the above purpose, the present application provides the following solutions:
[0006] In a first aspect, the present application provides a pixel circuit for improving the display effect of low gray levels. The pixel circuit for improving the display effect of low gray levels includes: an R pixel driving circuit, a G pixel driving circuit, and a B pixel driving circuit; the R pixel driving circuit includes: a first switching transistor, a second switching transistor, a third switching transistor, a fourth switching transistor, a capacitor, and an R pixel OLED.
[0007] The gate of the first switching transistor is connected to a first row driving signal, and the drain of the first switching transistor is connected to a column driving signal; the gate of the second switching transistor is connected to a second row driving signal, and the drain of the second switching transistor is connected to the column driving signal; the source of the first switching transistor and the source of the second switching transistor are connected to a common terminal; the common terminal is respectively connected to one end of the capacitor and the gate of the fourth switching transistor; the other end of the capacitor is grounded; the drain of the fourth switching transistor is connected to an array voltage terminal.
[0008] The drain of the third switching transistor is connected to an R pixel reset signal, the source of the third switching transistor is connected to a third row driving signal, the source of the third switching transistor is respectively connected to the anode of the R pixel OLED and the source of the fourth switching transistor; the cathode of the R pixel OLED is connected to a common voltage terminal.
[0009] The G pixel driving circuit and the B pixel driving circuit have the same circuit structure as the R pixel driving circuit. However, the drain of the third switching transistor in the G pixel driving circuit is connected to the G pixel reset signal, and the source of the third switching transistor is respectively connected to the anode of the G pixel OLED and the source of the fourth switching transistor. The drain of the third switching transistor in the B pixel driving circuit is connected to the B pixel reset signal, and the source of the third switching transistor is respectively connected to the anode of the B pixel OLED and the source of the fourth switching transistor.
[0010] In a second aspect, the present application further provides a control method for a pixel circuit applied to the pixel circuit for improving the low gray-scale display effect described in the first aspect. The control method for the pixel circuit for improving the low gray-scale display effect includes:
[0011] Determine whether the display effect of the pixel circuit at low gray scales is normal;
[0012] When the pixel circuit exhibits color deviation at low gray scales, determine the corresponding pixel reset signal and the corresponding pixel OLED according to the deviated color, and reduce the anode reset voltage of the corresponding pixel OLED through the corresponding pixel reset signal.
[0013] According to the specific embodiments provided by the present application, the following technical effects are disclosed:
[0014] In the present application, a switching transistor is respectively provided at the anodes of the R pixel OLED, the G pixel OLED, and the B pixel OLED, and different pixel reset signals are connected to the drains of the switching transistors. In actual application, it is necessary to control the corresponding pixel reset signal according to the deviated color of the pixel circuit at low gray scales, thereby pulling down the anode voltage of the corresponding pixel OLED, extending the anode reset time of the corresponding pixel OLED, making its effective light-emitting time within one frame shorter, and the corresponding brightness is relatively lower. Therefore, the color deviation phenomenon is more slight. Accordingly, the present application reduces the influence of the lateral leakage current between pixels on the display effect of the product and improves the low gray-scale display effect. Description of the Drawings
[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.
[0016] Figure 1 It is a schematic structural diagram of an R pixel driving circuit provided by an embodiment of the present application;
[0017] Figure 2 It is a schematic structural diagram of a G pixel driving circuit provided by an embodiment of the present application;
[0018] Figure 3 It is a schematic structural diagram of the B pixel driving circuit provided by an embodiment of the present application;
[0019] Figure 4 It is an effect diagram of driving signal control of an electronic display device provided by an embodiment of the present application;
[0020] Figure 5 It is a flowchart of a control method for a pixel circuit for improving low gray-scale display effect provided by an embodiment of the present application.
[0021] Symbol description:
[0022] The first switching transistor - M1, the second switching transistor - M2, the third switching transistor - M3, the fourth switching transistor - M4, the capacitor - C1. Specific embodiments
[0023] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the protection scope of the present application.
[0024] The purpose of the present application is to provide a pixel circuit for improving low gray-scale display effect and its control method, which reduces the influence of lateral leakage current between pixels on the display effect of the product.
[0025] To make the above objects, features and advantages of the present application more obvious and understandable, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.
[0026] Embodiment 1
[0027] As Figure 1 shown, this embodiment provides a pixel circuit for improving low gray-scale display effect. The pixel circuit for improving low gray-scale display effect includes: an R pixel driving circuit, a G pixel driving circuit, and a B pixel driving circuit.
[0028] Among them, the R pixel driving circuit includes: a first switching transistor M1, a second switching transistor M2, a third switching transistor M3, a fourth switching transistor M4, a capacitor C1, and an R pixel OLED. The gate of the first switching transistor M1 is connected to the first row driving signal ROW_1, and the drain of the first switching transistor M1 is connected to the column driving signal COL; the gate of the second switching transistor M2 is connected to the second row driving signal ROW_2, and the drain of the second switching transistor M2 is connected to the column driving signal COL; the source of the first switching transistor M1 and the source of the second switching transistor M2 are connected to a common terminal; the common terminal is respectively connected to one end of the capacitor C1 and the gate of the fourth switching transistor M4; the other end of the capacitor C1 is grounded; the drain of the fourth switching transistor M4 is connected to the array voltage terminal VDD_Arrary; the drain of the third switching transistor M3 is connected to the R pixel reset signal ROW_R, the gate of the third switching transistor M3 is connected to the third row driving signal ROW_3, and the source of the third switching transistor M3 is respectively connected to the anode of the R pixel OLED and the source of the fourth switching transistor M4; the cathode of the R pixel OLED is connected to the common voltage terminal VCOM.
[0029] As a preferred embodiment, the types of the first switching transistor M1 and the second switching transistor M2 are different, and the types of the second switching transistor M2, the third switching transistor M3, and the fourth switching transistor M4 are the same.
[0030] In one example, the first switching transistor M1 is a PMOS transistor, and the second switching transistor M2, the third switching transistor M3, and the fourth switching transistor M4 are all NMOS transistors.
[0031] In another example, the first switching transistor M1 is an NMOS transistor, and the second switching transistor M2, the third switching transistor M3, and the fourth switching transistor M4 are all PMOS transistors.
[0032] As Figure 2 and Figure 3 shown, the G pixel driving circuit and the B pixel driving circuit have the same circuit structure as the R pixel driving circuit, but in the G pixel driving circuit, the drain of the third switching transistor M3 is connected to the G pixel reset signal ROW_G, and the source of the third switching transistor M3 is respectively connected to the anode of the G pixel OLED and the source of the fourth switching transistor M4; in the B pixel driving circuit, the drain of the third switching transistor M3 is connected to the B pixel reset signal ROW_B, and the source of the third switching transistor M3 is respectively connected to the anode of the B pixel OLED and the source of the fourth switching transistor M4.
[0033] Furthermore, the third switching transistor M3 in the R pixel driving circuit is used to reset the anode of the R pixel OLED; the third switching transistor M3 in the G pixel driving circuit is used to reset the anode of the G pixel OLED; the third switching transistor M3 in the B pixel driving circuit is used to reset the anode of the B pixel OLED.
[0034] Further, the first switching transistor M1 and the second switching transistor M2 in the R pixel driving circuit are used to expand the gate voltage writing range of the fourth switching transistor M4; the first switching transistor M1 and the second switching transistor M2 in the G pixel driving circuit are used to expand the gate voltage writing range of the fourth switching transistor M4; the first switching transistor M1 and the second switching transistor M2 in the B pixel driving circuit are used to expand the gate voltage writing range of the fourth switching transistor M4.
[0035] Further, the fourth switching transistor M4 in the R pixel driving circuit is used to drive the anode voltage of the R pixel OLED; the fourth switching transistor M4 in the G pixel driving circuit is used to drive the anode voltage of the G pixel OLED; the fourth switching transistor M4 in the B pixel driving circuit is used to drive the anode voltage of the B pixel OLED.
[0036] As a preferred implementation, as Figure 4 shown, a complete electronic display device is usually composed of multiple groups of R / G / B pixel OLEDs. In order to effectively control all single-pixel OLEDs in the electronic display device, the pixel reset signals can be aggregated (e.g., aggregating the R pixel reset signals ROW_R of all R pixel OLEDs), and finally the DIC performs full-surface control. The advantage of such an operation is that the anode reset voltages of all single-pixel OLEDs in the electronic display device can be controlled simultaneously. For the first row driving signal, the second row driving signal, and the third row driving signal, they are collectively referred to as row driving signals, and all OLEDs can also be uniformly controlled in the same way as the aggregation of single-pixel reset signals.
[0037] Embodiment 2
[0038] As Figure 5 shown, this embodiment provides a control method for a pixel circuit used to improve the low gray-scale display effect described in Embodiment 1. The control method for the pixel circuit used to improve the low gray-scale display effect includes:
[0039] Step S1: Determine whether the display effect of the pixel circuit at low gray scale is normal.
[0040] Step S2: When the pixel circuit shows a color deviation phenomenon at low gray scale, determine the corresponding pixel reset signal and the corresponding pixel OLED according to the deviated color, and reduce the anode reset voltage of the corresponding pixel OLED through the corresponding pixel reset signal.
[0041] In this embodiment, step S2 specifically includes:
[0042] When the pixel circuit shows a phenomenon of red deviation at low gray levels, the anode reset voltage of the R-pixel OLED is reduced through the R-pixel reset signal, and the anode reset voltage of the R-pixel OLED is made less than the anode reset voltages of the B-pixel OLED and the G-pixel OLED.
[0043] When the pixel circuit shows a phenomenon of green deviation at low gray levels, the anode reset voltage of the G-pixel OLED is reduced through the G-pixel reset signal, and the anode reset voltage of the G-pixel OLED is made less than the anode reset voltages of the R-pixel OLED and the B-pixel OLED.
[0044] When the pixel circuit shows a phenomenon of blue deviation at low gray levels, the anode reset voltage of the B-pixel OLED is reduced through the B-pixel reset signal, and the anode reset voltage of the B-pixel OLED is made less than the anode reset voltages of the R-pixel OLED and the G-pixel OLED.
[0045] Furthermore, the control method of the pixel circuit for improving the low gray level display effect further includes:
[0046] When the R-pixel OLED, G-pixel OLED, and B-pixel OLED in the pixel circuit are in the anode reset stage, the first row driving signal and the third row driving signal are set high, and the column driving signal and the second row driving signal are set low.
[0047] When the R-pixel OLED, G-pixel OLED, and B-pixel OLED in the pixel circuit are in the light-emitting stage, the second row driving signal is set high, and the column driving signal, the first row driving signal, and the third row driving signal are set low.
[0048] In summary, the present application mainly has the following advantages:
[0049] (1) After the anode reset of the OLED is increased in the present application, the display contrast effect is better.
[0050] (2) The present application can, according to the characteristics of the R / G / B pixel OLEDs, independently control the anode reset voltages of the R / G / B pixels, reduce the influence of leakage current between low gray level pixels, and improve the low gray level display effect.
[0051] All actions of obtaining signals, information, or data in the present application are carried out on the premise of complying with the corresponding data protection regulations and policies of the country where it is located and with the authorization given by the owner of the corresponding device.
[0052] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the various embodiments can be referred to each other.
[0053] In this text, specific examples are used to illustrate the principles and implementation manners of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application. At the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation manners and application scopes. To sum up, the content of this specification should not be construed as a limitation to the present application.
Claims
1. A pixel circuit for improving the low gray-scale display effect, characterized in that, The pixel circuit for improving the low gray-scale display effect includes: an R pixel driving circuit, a G pixel driving circuit, and a B pixel driving circuit; the R pixel driving circuit includes: a first switching transistor, a second switching transistor, a third switching transistor, a fourth switching transistor, a capacitor, and an R pixel OLED. The gate of the first switching transistor is connected to a first row driving signal, and the drain of the first switching transistor is connected to a column driving signal; the gate of the second switching transistor is connected to a second row driving signal, and the drain of the second switching transistor is connected to the column driving signal; the source of the first switching transistor and the source of the second switching transistor are connected to a common terminal; the common terminal is respectively connected to one end of the capacitor and the gate of the fourth switching transistor; the other end of the capacitor is grounded; the drain of the fourth switching transistor is connected to an array voltage terminal. The drain of the third switching transistor is connected to an R pixel reset signal, the gate of the third switching transistor is connected to a third row driving signal, and the source of the third switching transistor is respectively connected to the anode of the R pixel OLED and the source of the fourth switching transistor; the cathode of the R pixel OLED is connected to a common voltage terminal. The G pixel driving circuit and the B pixel driving circuit have the same circuit structure as the R pixel driving circuit, but the drain of the third switching transistor in the G pixel driving circuit is connected to a G pixel reset signal, and the source of the third switching transistor is respectively connected to the anode of the G pixel OLED and the source of the fourth switching transistor; the drain of the third switching transistor in the B pixel driving circuit is connected to a B pixel reset signal, and the source of the third switching transistor is respectively connected to the anode of the B pixel OLED and the source of the fourth switching transistor.
2. The pixel circuit for improving the low gray-scale display effect according to claim 1, wherein The third switching transistor in the R pixel driving circuit is used to reset the anode of the R pixel OLED; the third switching transistor in the G pixel driving circuit is used to reset the anode of the G pixel OLED; the third switching transistor in the B pixel driving circuit is used to reset the anode of the B pixel OLED.
3. The pixel circuit for improving the low gray-scale display effect according to claim 1, wherein The first switching transistor and the second switching transistor in the R pixel driving circuit are used to expand the gate voltage writing range of the fourth switching transistor; the first switching transistor and the second switching transistor in the G pixel driving circuit are used to expand the gate voltage writing range of the fourth switching transistor; the first switching transistor and the second switching transistor in the B pixel driving circuit are used to expand the gate voltage writing range of the fourth switching transistor.
4. The pixel circuit for improving the low gray-scale display effect according to claim 1, characterized in that, The fourth switching transistor in the R pixel driving circuit is used to drive the anode voltage of the R pixel OLED; the fourth switching transistor in the G pixel driving circuit is used to drive the anode voltage of the G pixel OLED; the fourth switching transistor in the B pixel driving circuit is used to drive the anode voltage of the B pixel OLED.
5. The pixel circuit for improving the low gray-scale display effect according to claim 1, wherein The types of the first switching transistor and the second switching transistor are different, and the types of the second switching transistor, the third switching transistor, and the fourth switching transistor are the same.
6. The pixel circuit for improving the low gray-scale display effect according to claim 5, wherein The first switching transistor is a PMOS transistor, and the second switching transistor, the third switching transistor, and the fourth switching transistor are NMOS transistors, or the first switching transistor is an NMOS transistor, and the second switching transistor, the third switching transistor, and the fourth switching transistor are PMOS transistors.
7. A control method for a pixel circuit for improving low gray-scale display effects according to any one of claims 1-6, characterized in that, The control method of the pixel circuit for improving the low gray-scale display effect includes: Determine whether the display effect of the pixel circuit is normal at low gray scales; When the pixel circuit has a color cast phenomenon at low gray scales, determine the corresponding pixel reset signal and the corresponding pixel OLED according to the color cast, and reduce the anode reset voltage of the corresponding pixel OLED through the corresponding pixel reset signal.
8. The control method of the pixel circuit for improving the low gray-scale display effect according to claim 7, It is characterized in that when the pixel circuit has a color cast phenomenon at low gray scales, determine the corresponding pixel reset signal and the corresponding pixel OLED according to the color cast, and reduce the anode reset voltage of the corresponding pixel OLED through the corresponding pixel reset signal, specifically including: When the pixel circuit has a red color cast phenomenon at low gray scales, reduce the anode reset voltage of the R pixel OLED through the R pixel reset signal, and make the anode reset voltage of the R pixel OLED less than the anode reset voltages of the B pixel OLED and the G pixel OLED; When the pixel circuit has a green color cast phenomenon at low gray scales, reduce the anode reset voltage of the G pixel OLED through the G pixel reset signal, and make the anode reset voltage of the G pixel OLED less than the anode reset voltages of the R pixel OLED and the B pixel OLED; When the pixel circuit has a blue color cast phenomenon at low gray scales, reduce the anode reset voltage of the B pixel OLED through the B pixel reset signal, and make the anode reset voltage of the B pixel OLED less than the anode reset voltages of the R pixel OLED and the G pixel OLED.
9. The control method of the pixel circuit for improving the low gray-scale display effect according to claim 7, characterized in that The control method of the pixel circuit for improving the low gray-scale display effect further includes: When the R pixel OLED, G pixel OLED, and B pixel OLED in the pixel circuit are in the anode reset stage, set the first row driving signal and the third row driving signal to high, and set the column driving signal and the second row driving signal to low.
10. The control method of the pixel circuit for improving the low gray-scale display effect according to claim 7, characterized in that, The control method of the pixel circuit for improving the low gray-scale display effect further includes: When the R pixel OLED, G pixel OLED, and B pixel OLED in the pixel circuit are in the light-emitting stage, set the second row driving signal to high, and set the column driving signal, the first row driving signal, and the third row driving signal to low.