Pixel drive circuit of display panel and display device

This application discloses a pixel drive circuit of a display panel and a display device. The pixel drive circuit of a display panel includes: a pixel electrode; a data line, configured to provide a data voltage of a current pixel; a power supply circuit, configured to provide a power supply voltage; and an amplification circuit, configured to amplify the data voltage provided by the data line and output the amplified data voltage to the pixel electrode.

This application claims priority to Chinese Patent Application No. CN201821629477.6, filed with the Chinese Patent Office on Oct. 8, 2018 and entitled “PIXEL DRIVE CIRCUIT OF DISPLAY PANEL AND DISPLAY DEVICE”, which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

This application relates to the field of display technologies, and in particular, to a pixel drive circuit of a display panel and a display device.

BACKGROUND

The description herein provides only background information related to this application, but does not necessarily constitute the existing technology.

With the development and advancement of science and technologies, flat-panel displays become mainstream products of displays and are widely applied contributing to hotspot features such as thinness, power saving and low radiation. The flat-panel display includes a thin film transistor-liquid crystal display (TFT-LCD), an organic light-emitting diode (OLED) display, and the like. The TFT-LCD controls rotation directions of liquid crystal molecules and refracts out light of a backlight module to generate an image, and has many advantages such as thinness, power saving and no radiation. The OLED display is made of an organic electroluminescent light-emitting diode and has such advantages as self-luminance, a quick response, a high definition and contrast, and a capability of achieving flexible display and a large-area full color display.

A display panel is a voltage-driven component. However, in the technologies well know in the art, there is rarely displaying-drive architecture by using which a penetration rate of the display panel is increased and power consumption is reduced, and thus an optimal displaying effect cannot be achieved.

Technical Problem

Display panels have relatively large drive architecture power consumption and a low panel penetration rate.

SUMMARY

This application provides a pixel drive circuit of a display panel and a display device that are drive architectures enabling a voltage applied to a pixel electrode to be greater than a voltage of a data line, to increase a penetration rate of the display panel and reduce power consumption.

To achieve the foregoing objectives, this application provides a pixel drive circuit of a display panel, comprising:

a pixel electrode;

a first scanning line, configured to provide a first scanning signal corresponding to a current pixel;

a data line, configured to provide a data voltage of the current pixel in cooperation with the first scanning signal;

a power supply circuit, configured to provide a power supply voltage; and

an amplification circuit, electrically connected to the data line and the power supply circuit, wherein an output end of the amplification circuit is electrically connected to the pixel electrode, and the amplification circuit amplifies the data voltage provided by the data line and outputs the amplified data voltage to the pixel electrode.

This application further discloses a pixel drive circuit of a display panel, comprising:

a pixel electrode;

a first scanning line, configured to provide a first scanning signal corresponding to a current pixel;

a second scanning line, configured to provide a second scanning signal corresponding to the current pixel;

a power supply voltage line, configured to provide a power supply voltage;

a data line, configured to provide a data voltage of the current pixel in cooperation with the first scanning signal; and

a first switch circuit, a second triode, and a third switch circuit, wherein

a gate end of the first switch circuit is in control connection with the first scanning signal; a source end of the first switch circuit is electrically connected to the data line; and a drain end of the first switch circuit is connected to a gate end of the second triode;

a source end of the second triode is electrically connected to the power supply voltage line, and a drain end of the second triode is electrically connected to a source end of the third switch circuit;

a gate end of the third switch circuit is in control connection with the second scanning signal, and a drain end of the third switch circuit is electrically connected to an input end of the pixel electrode; and

a first capacitor is formed between the drain end of the first switch circuit and the drain end of the second triode.

This application further discloses a display device, comprising:

a display panel comprising the pixel drive circuit according to any one of the foregoing aspects; and

a drive module, configured to drive the display panel, wherein

the drive module outputs a first scanning signal, a power supply voltage, and a data voltage to the display panel; and

in a scanning period of a row of pixels on the display panel, the first scanning signal output by the drive module is at a high level and provides the data voltage of the current pixel to the amplification circuit in cooperation with the data voltage of the data line; and the power supply voltage of the power supply circuit is at a high level and supplies power to the amplification circuit, and the amplification circuit amplifies the data voltage and outputs the amplified data voltage to the pixel electrode.

Compared with other technologies well known in the art, according to this application, the first scanning line outputs the first scanning signal corresponding to the current pixel, and the data line inputs a signal of the data voltage and provides the data voltage of the current pixel in cooperation with the first scanning signal. When the data voltage is input, the power supply circuit correspondingly enables a high level and supplies power to the amplification circuit, and in this case, the data voltage input by the data line is output to the pixel electrode by using the amplification circuit, to provide a higher pixel driving voltage to drive the pixel electrode. An improvement is made in this solution based on the technology well known in the art. Based on such an improvement, the pixel driving voltage is greater than the data voltage of the data line, a penetration rate of the panel is increased, and power consumption is reduced, so that a driving voltage applied to the pixel electrode may be greater than the driving voltage of the data line, thereby ensuring a displaying effect.

DETAILED DESCRIPTION

Specific structures and functional details disclosed herein are merely representative, and are intended to describe the objectives of the exemplary embodiments of this application. However, this application may be specifically implemented in many alternative forms, and should not be construed as being limited to the embodiments set forth herein.

In the description of this application, it should be understood that orientation or position relationships indicated by the terms such as “center”, “transverse”, “on”, “below”, “left”, “right”, “vertical”. “horizontal”, “top”, “bottom”, “inside”, and “outside” are based on orientation or position relationships shown in the accompanying drawings, and are used only for ease and brevity of illustration and description, rather than indicating or implying that the mentioned apparatus or component must have a particular orientation or must be constructed and operated in a particular orientation. Therefore, such terms should not be construed as limiting of this application. In addition, the terms such as “first” and “second” are used only for the purpose of description, and should not be understood as indicating or implying the relative importance or implicitly specifying the number of the indicated technical features. Therefore, a feature defined by “first” or “second” can explicitly or implicitly includes one or more of said features. In the description of this application, unless otherwise stated, “a plurality of” means two or more than two. In addition, the terms “include”, “comprise” and any variant thereof are intended to cover non-exclusive inclusion.

In the description of this application, it should be noted that unless otherwise explicitly specified or defined, the terms such as “mount”, “install”, “connect”, and “connection” should be understood in a broad sense. For example, the connection may be a fixed connection, a detachable connection, or an integral connection; or the connection may be a mechanical connection or an electrical connection; or the connection may be a direct connection, an indirect connection through an intermediary, or internal communication between two components. Persons of ordinary skill in the art may understand the specific meanings of the foregoing terms in this application according to specific situations.

This application is described below with reference to the accompanying drawings and optional embodiments.

As shown inFIG. 2toFIG. 6, this application discloses a display device100, including: a display panel101and a drive module that is configured to drive the display panel101.

A pixel drive circuit110of the display panel101includes: a pixel electrode120; a first scanning line, configured to provide a first scanning signal Gate 1 corresponding to a current pixel; a data line140, configured to provide a data voltage VDataof the current pixel in cooperation with the first scanning signal Gate 1; a power supply circuit150, configured to provide a power supply voltage VDD; and an amplification circuit160, electrically connected to the data line140and the power supply circuit150, where an output end of the amplification circuit160is electrically connected to the pixel electrode120, and the amplification circuit160amplifies the data voltage provided by the data line140and outputs the amplified data voltage to the pixel electrode120.

Compared with the solution shown inFIG. 1, for the pixel drive circuit110inFIG. 1, a scanning line Gate signal controls a TFT switch. The TFT switch forms a storage capacitor (Cst) with a common line on an array substrate (Array_COM), and forms a pixel capacitor (Clc) with a common line on a color film substrate (CF_COM). In a stable state, a voltage of a node m of the display panel of the pixel drive circuit110may maximally be equal to a voltage VDataof the data line140input by the data line140. The first scanning line in this solution outputs the first scanning signal Gate 1 corresponding to the current pixel. The data line140inputs a signal of the data voltage and provides the data voltage of the current pixel in cooperation with the first scanning signal Gate 1. When the data voltage is input, the power supply circuit150correspondingly enables a high level and supplies power to the amplification circuit160. In this case, the data voltage input by the data line140is output to the pixel electrode120by using the amplification circuit160, so that a pixel drive voltage higher than the data voltage input by the data line140can be provided to drive the pixel electrode120. Further, according to this solution, a voltage value on Data on the data line140can be dramatically reduced, and a fluctuation amplitude of the voltage on the data line140can be further reduced, so that the display panel101can satisfy power demands of the display panel101by amplifying a relatively small data voltage by using the amplification circuit160to drive the display panel101, a penetration rate of the display panel101is increased, power consumption of the display panel101is reduced, and a drive voltage applied to the pixel electrode may be greater than a drive voltage of the data line140, thereby ensuring a display effect.

Based on the architecture of the pixel drive circuit110, in a scanning period of a row of pixels of the display panel101of the drive module, the first scanning signal Gate 1 output by the drive module is at a high level and provides the data voltage of the current pixel to the amplification circuit160in cooperation with the data voltage of the data line140. A power supply voltage of the power supply circuit150is at a high level and supplies power to the amplification circuit160. The amplification circuit160amplifies the data voltage and outputs the amplified data voltage to the pixel electrode120.

When the drive module outputs the first scanning signal Gate 1 at the high level, the data line140outputs the data voltage in cooperation, and the power supply circuit150provides the power supply voltage at the high level to supply power to the amplification circuit160. In this case, the amplification circuit160amplifies the data voltage and outputs the amplified data voltage to the pixel electrode120, so that the drive voltage applied to the pixel electrode may be greater than the drive voltage of the data line140, a penetration rate of the display panel101is increased, and power consumption is reduced.

Optionally, in this embodiment, as shown inFIG. 3, the power supply circuit150includes a power supply voltage line151, and the amplification circuit160includes a second triode161. A gate end of the second triode161is in control connection with the data line140, a source end of the second triode161is electrically connected to the power supply voltage line151, and a drain end of the second triode161is in control connection with the pixel electrode120. The second triode161may be a TFT, or other structures or circuits that have the same function.

In this solution, the amplification circuit160is an amplification triode, that is, the second triode T2. Herein, the second triode T2 is mainly used for amplification instead of being purely used as a switch. When a signal transmitted by the data line140is relatively small, the signal is amplified by T2, so that the signal has sufficient energy to drive an execution mechanism to complete a particular work.

In this embodiment, optionally, the pixel drive circuit110further includes a first switch circuit170. The data line140is electrically connected to the amplification circuit160by using the first switch circuit170. The data line140is electrically connected to a source end of the first switch circuit170, a drain end of the first switch circuit170is in control connection with the amplification circuit160, and a gate end of the first switch circuit170is in control connection with the first scanning signal Gate 1 of the display panel101. The first switch circuit170may be a TFT or may be other structures or circuits that have the same function.

In this solution, when the first scanning signal Gate 1 is at a high level, the first switch circuit T1 is conducted, and in this case, the data line140provides the data voltage corresponding to the current pixel to the amplification circuit160, thereby implementing input of the data voltage corresponding to the current pixel by the data line140. The first switch circuit170herein is directly controlled by the first scanning signal Gate 1 which controls input and cut-off of the drive circuit of the data voltage.

In this embodiment, optionally, a first capacitor C is formed between the drain end of the first switch circuit170and the output end of the amplification circuit160.

In this solution, the first capacitor180is formed between the drain end of the first switch circuit170and the output end of the amplification circuit160. According to the pixel drive circuit110, when an input of the first scanning signal Gate 1 is at a high level, the data voltage charges the first capacitor180, or when the first scanning signal Gate 1 is at a low level, the first capacitor180maintains a voltage difference between two ends of the capacitor. Therefore, when a voltage at the output end (point n) of the amplification circuit160is amplified, a voltage at the drain end (point m) of the first switch circuit170is pulled up simultaneously, and the voltage at the drain end of the first switch circuit170is maintained and enhanced.

Referring toFIG. 4andFIG. 5, in another embodiment of this application, different from the foregoing embodiments, the pixel drive circuit110further includes: a second scanning line, configured to provide a second scanning signal Gate 2 corresponding to a current pixel; and a third switch circuit190, where the third switch circuit190is connected between the output end of the amplification circuit160and the pixel electrode120, a gate end of the third switch circuit190is electrically connected to the second scanning line, a source end of the third switch circuit190is electrically connected to the output end of the amplification circuit160, and a drain end of the third switch circuit190is electrically connected to the pixel electrode120. The third switch circuit190may be a TFT or may be other structures or circuits that have the same function.

In this solution, a switch circuit, that is, the third switch circuit T3, is arranged between the amplification circuit160and the pixel electrode120. The switch circuit is disconnected from the data line140and the amplification circuit when a scanning period of a current row is completed, preventing the amplification circuit160and the data line140from continuously affecting the voltage of the pixel electrode120, so that the pixel electrode120can maintain a pixel drive voltage higher than that related to the data voltage of the data line140in a frame period.

Based on the architecture of the pixel drive circuit110, the drive module further outputs a second scanning signal Gate 2; and the scanning period of a row of pixels on the display panel101includes a first periodic time and a second periodic time.

In a first periodic time T2, the first scanning signal Gate 1 is at a high level, and the second scanning signal Gate 2 is at a high level; the power supply voltage is at a low level; and the data line140outputs a data voltage corresponding to the current pixel.

In a second periodic time T3, the first scanning signal Gate 1 is at a low level, the second scanning signal Gate 2 is at a high level, and the power supply voltage is at a high level.

In this solution, in the scanning period of a row of pixels, to implement that the pixel electrode120can maintain a pixel drive voltage higher than that related to the data voltage of the data line140in a frame period, work in different time segments in a period is different. In a first period T2, both the first scanning signal Gate 1 and the second scanning signal Gate 2 are at a high level, the power supply voltage is at a low level, the first switch circuit170and the third switch circuit190are turned on, and the second triode161is pulled up to VGH and a data signal is input to the second triode161at the same time. In this case, a voltage at the node m is Vm=VData, voltages at the nodes n and o are Vn=Vo=VDD_L, and a voltage of the first capacitor180C is Vc=VData−VDD_L. At the time T3, the voltage is at a pulled-up stage, and in this case, the first scanning signal Gate 1 is at a VGL, T1 is turned off, the second scanning signal Gate 2 is at VGH, and T3 remains in a turned-on state. In this case, the node m is in a floating state, VDD is pulled up from VDD_L to VDD_H, and a current flowing through T2 is I2=k(VData−VDD_L−Vth2);

The voltages of the nodes m/n/o are respectively.

In this embodiment, optionally, the scanning period of a row of pixels on the display panel101includes an initialization period T1set before the first periodic time. In the initialization period T1, the first scanning signal Gate 1 output by the drive module is at a low level, and the second scanning signal Gate 2 is at a high level.

In this solution, there is further an initialization period before the first periodic time of the scanning period of the row of pixels on the display panel101, an initialization action is performed in this period, and in this case, T3 is turned on, T1 is turned off, and the node m is at a high level when a previous frame ends. In this case, the second triode161is enabled, and a low level signal VDD_Lis input to the power supply voltage. In the initialization period, the voltages of the nodes n/o are Vn=Vo=VDD_L. The power supply voltage signal VDDis sent by a control chip on the drive module to directly control a high/low level of the display panel101, where the drive module is electrically connected to the display panel101by using a separate lead.

In this embodiment, optionally, the scanning period of a row of pixels on the display panel101further includes a third periodic time T4set after the second periodic time. In the third periodic time T4, the first scanning signal Gate 1 is at a low level, and the second scanning signal Gate 2 is at a low level.

In this solution, in the third periodic time T4, both the first scanning signal Gate 1 and the second scanning signal Gate 2 output by the drive module are at a low level VGL, and T1 and T3 are both turned off. In this case, the voltage of the node m is at a high potential to enable T2 to be turned on, and the node n may be charged to VDD_Hby T2 that is turned on, so that in this case, the node o can still remain at a high potential after T3 is turned off.

In this embodiment, optionally, the scanning period of a row of pixels on the display panel101further includes a third periodic time T4set after the second periodic time T3. In the third periodic time T4, the first scanning signal Gate 1 output by the drive module is at a low level and the second scanning signal Gate 2 is at a low level.

In this solution, in the third periodic time, both the first scanning signal Gate 1 and the second scanning signal Gate 2 are at a low level VGL, and T1 and T3 are both turned off. In this case, the voltage of the node m is at a high potential to enable T2 to be turned on, and the node n may be charged to VDD_Hby T2 that is turned on, so that in this case, the node o can still remain at a high potential after T3 is turned off.

In still another embodiment of this application, referring toFIG. 4toFIG. 5, a pixel drive circuit110of a display panel101is disclosed. The pixel drive circuit110of the display panel101includes: a pixel electrode120; a first scanning line, configured to provide a first scanning signal Gate 1 corresponding to a current pixel; a second scanning line, configured to provide a second scanning signal Gate 2 corresponding to the current pixel; a power supply voltage line151, configured to provide a power supply voltage; a data line140, configured to provide a data voltage of the current pixel in cooperation with the first scanning signal Gate 1; and a first switch circuit170, a second triode161, and a third switch circuit190.

A gate end of the first switch circuit170is in control connection with the first scanning signal Gate 1; a source end of the first switch circuit170is connected to the data line140; and a drain end of the first switch circuit170is connected to a gate end of the second triode161. A source end of the second triode161is electrically connected to the power supply voltage line151, and a drain end of the second triode161is electrically connected to a source end of the third switch circuit190. A gate end of the third switch circuit190is in control connection with the second scanning signal Gate 2, and a drain end of the third switch circuit190is electrically connected to the pixel electrode120.

A first capacitor180is formed between the drain end of the first switch circuit170and the drain end of the second triode161; a storage capacitor Cstis formed between the drain end of the third switch circuit190and an array substrate of the display panel101, and a pixel capacitor Clcis formed between the drain end of the third switch circuit190and a color film substrate of the display panel101.

In this solution, in the scanning period of a row of pixels, the scanning period of the row of pixels is divided at four time points T1, T2, T3, and T4. It should be noted that a frame time (60 Hz T= 1/60=16.7 ms, and 120 Hz T=8.33 ms) T=(T1+T2+T3+T4)·t, where t is a quantity of gate lines, that is, a quantity of times of scanning performed in a frame time. For example, for a display panel101having a high definition HD resolution of 1366*768, there are 768 gate lines, t=768, and correspondingly, T1+T2+T3+T4=21.7 μs (for the case of 60 Hz, 60 Hz may also be 120 Hz, and a scanning time t in a 120 Hz case is equal to 10.85 μs). For a display panel101having a full high definition resolution, t=1080, and correspondingly, T1+T2+T3+T4=15.4 μs. For a display panel101having a 4K resolution, t=2160, and correspondingly, T1+T2+T3+T4=7.7 μs.

In this solution, in the time T1, an initialization action is performed, the Gate 1 is at a high level VGH, the Gate 2 is at a low level VGL, and in this case, T3 is turned on, T1 is turned off, and the node m is at a high level when a previous frame ends, so that T2 is turned on. In this case, VDDsends a low-level signal VDD_L(VDDis a signal sent by a control chip on the drive circuit to directly control a high/low level signal of the display panel101, where the drive circuit is electrically connected to the display panel101by using a separate lead). Therefore, in this case, voltages of nodes n/o are Vn=Vo=VDD_L. At the time T2, data signal writing is performed, and in this case, the Gate 2 is pulled up to VGH, and a data signal starts to be input. In this case, a voltage of a node m is Vm=VData, the Gate 1 remains at a VHGto enable T3 to be continuously turned on, the voltages of the nodes n and o are Vn=Vo=VDD_L, and in this case, the voltage of the capacitor C is Vc=VData−VDD_L. The time T3 is a voltage pulled-up stage, and in this case, the Gate 2 at this time is at a VGL, T1 is turned off, the node m is in a floating state, VDDis pulled up to VDD_Hfrom VDD_L, and a current flowing through T2 is I2=k(VData−VDD_L−Vth2);

The voltages of the nodes m/n/o are respectively:

T is a time length of T3, and Vth2is a threshold voltage of T2. The time T4is the last light emitting phase, and in this case, the Gate 1 and the Gate 2 are both at a VGL. T1 and T3 are turned off at the same time, and in this case, the voltage of the node m is at a high potential to enable T2 to be turned on. The node n may be charged to VDD_Hby T2 that is turned on, and in this case, the node o can still remain at the high potential after T3 is turned off. K is a constant related to a mobility rate of a semiconductor layer. k=½*μ*Cox*W/L, μ is an electronic mobility rate of a semiconductor layer, Coxis capacitance per unit area of a TFT device in an MIS structure, and W/L is a width to length ratio of a TFT channel.

The first scanning line of the display panel101outputs the first scanning signal Gate 1 corresponding to the current pixel. When the first scanning signal Gate 1 is at a high level, the first switch circuit170is conducted, the data line140inputs the data voltage VDatato the output end of the first switch circuit170by using the first switch circuit170, and the power supply circuit150is enabled to be at a low level VDD_L. In this case, the data voltage charges the first capacitor180, the point m is at a high level, the second triode161is turned on, and the point n is at a VDD_L. In this case, the voltage at the first capacitor180is: Vc=VData−VDD_L. In this case, the first scanning signal Gate 1 is set to be at a low level VDD_L, the power supply circuit150is enabled to be at a high level VDD_Hto charge the second triode161, to amplify an input of the gate end of the second triode161, and in this case, a current flowing through the second triode T2 is I2=k(VData−VDD_L−Vth2), and the voltage of the output end of the second triode161, that is, the voltage of the node n is:

Vth2is a threshold voltage of T2, and k is a constant related to a mobility rate of a semiconductor layer. k=½*μ*Cox*W/L, μ is an electronic mobility rate of the semiconductor layer, Coxis capacitance per unit area of a TFT device in an MIS structure, and W/L is a width to length ratio of a TFT channel. Because in this case, the node m is in a floating state, the first capacitor180maintains a voltage difference at the two ends of the capacitor. When the voltage of the output end of the amplification circuit160is amplified, the voltage of the drain end of the first switch circuit170is pulled up at the same time, and the voltage of the drain end of the first switch circuit170is maintained and enhanced, that is:

In this case, the second scanning signal Gate 2 is set to be at a high level, and Vmcharges the pixel electrode120by using the third switch circuit190, so that the pixel electrode120can maintain a higher pixel drive voltage related to the data voltage of the data line140in a frame period. In this case, the first scanning signal Gate 1 is set to be at a low level, so that the first switch circuit170disconnects a connection between the data line140and the amplification circuit, preventing the second triode161and the data line140from continuously affecting the voltage of the pixel electrode120.

The technical solution of this application may be widely applied to flat-panel displays such as a TFT-LCD, an OLED display, and the like.

The foregoing contents are detailed descriptions of this application in conjunction with specific optional embodiments, and it should not be considered that the specific implementation of this application is limited to these descriptions. Persons of ordinary skill in the art can further make simple deductions or replacements without departing from the concept of this application, and such deductions or replacements should all be considered as falling within the protection scope of this application.