This application claims the priority of Chinese Patent Application No. 202310962955.4, filed on Jul. 31, 2023, the content of which is incorporated herein by reference in its entirety.
The present disclosure generally relates to the field of display technology and, more particularly, relates to display panels and display devices.
With characteristics of self-illumination, fast response, wide color gamut, large viewing angle, and high brightness, organic light-emitting diodes (OLEDs) are widely used to make thin display devices and flexible display devices and have become a focus of research in the field of display technology. OLEDs require current drive. For example in the display field, a drive transistor in a pixel circuit provides a drive current to an OLED to make it emit light. It is needed to provide a stable drive current to the OLED to ensure the display performance in applications. In existing technologies, the signal that drives the pixel circuit is provided through a peripheral circuit. At the moment of display after power on, some OLEDs flicker and cause display issues. Thus, it is desirable for display panels and display devices that prevent power-on flickering of OLEDs.
The disclosed structures and methods are directed to at least partially alleviate one or more problems set forth above and to solve other problems in the art.
One aspect of the present disclosure provides a display panel that includes a light-emitting element, a pixel circuit, and a peripheral drive circuit. The pixel circuit at least includes a drive module, a first reset module, and a compensation module. The drive module and the light-emitting element are connected in series between a first power supply voltage signal terminal and a second power supply voltage signal terminal. The drive module is used to generate a drive current to drive the light-emitting element to emit light. The first reset module is electrically connected to a control terminal of the drive module and used to initialize the control terminal of the drive module. The compensation module is connected in series between the control terminal of the drive module and a second terminal of the drive module to compensate a voltage of the control terminal of the drive module. The peripheral drive circuit provides a drive signal to the pixel circuit. An operation process of the display panel at least includes a power-on stage and a display stage in sequence. The power-on stage at least includes a first phase and a second phase in sequence. The power-on stage includes frames that are consecutive. During a period of at least part of frames of the power-on stage, the peripheral drive circuit provides a first control signal to a control terminal of the first reset module and the first reset module is turned. The peripheral drive circuit provides a second control signal to a control terminal of the compensation module and the compensation module is turned on. In the second phase, the peripheral drive circuit provides a first power supply voltage to the first power supply voltage signal terminal and/or provides a second power supply voltage to the second power supply voltage signal terminal.
Another aspect of the present disclosure provides a display device that contains a display panel. The display panel includes a light-emitting element, a pixel circuit, and a peripheral drive circuit. The pixel circuit at least includes a drive module, a first reset module, and a compensation module. The drive module and the light-emitting element are connected in series between a first power supply voltage signal terminal and a second power supply voltage signal terminal. The drive module is used to generate a drive current to drive the light-emitting element to emit light. The first reset module is electrically connected to a control terminal of the drive module and used to initialize the control terminal of the drive module. The compensation module is connected in series between the control terminal of the drive module and a second terminal of the drive module to compensate a voltage of the control terminal of the drive module. The peripheral drive circuit provides a drive signal to the pixel circuit. An operation process of the display panel at least includes a power-on stage and a display stage in sequence. The power-on stage at least includes a first phase and a second phase in sequence. The power-on stage includes frames that are consecutive. During a period of at least part of frames of the power-on stage, the peripheral drive circuit provides a first control signal to a control terminal of the first reset module and the first reset module is turned. The peripheral drive circuit provides a second control signal to a control terminal of the compensation module and the compensation module is turned on. In the second phase, the peripheral drive circuit provides a first power supply voltage to the first power supply voltage signal terminal and/or provides a second power supply voltage to the second power supply voltage signal terminal.
Other aspects or embodiments of the present disclosure can be understood by those skilled in the art in light of the description, the claims, and the drawings of the present disclosure.
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure. The drawings are merely examples for illustrative purposes according to various disclosed embodiments and are not intended to limit the scope of the present disclosure.
Reference will now be made in detail to exemplary embodiments of the disclosure, which are illustrated in the accompanying drawings. Unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the invention.
The following description for at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.
Techniques, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered a part of the specification.
In all examples shown and discussed herein, any specific values are to be construed as illustrative only and not as limiting. Accordingly, other examples of the exemplary embodiments may have different values.
It should be noted that similar reference numerals and letters indicate similar items in the following figures. Therefore, once an item is defined in one figure, it does not require further discussion in the following figures.
The present disclosure provides a display panel and a display device to improve power-on flicker of light-emitting elements and reduce power consumption of display panels.
A first aspect of the present disclosure provides a display panel. The display panel includes a light-emitting element, a pixel circuit, and a peripheral drive circuit. The pixel circuit at least includes a drive module, a first reset module, and a compensation module. The drive module and light-emitting element are connected in series between first and second power supply voltage signal terminals. The drive module is used to generate a drive current to drive the light-emitting element to emit light. The first reset module is electrically connected to a control terminal of the drive module, and is used to initialize the control terminal of the drive module. The compensation module is connected in series between the control terminal of the drive module and an output terminal of the drive module, compensating the voltage of the control terminal of the drive module. The peripheral drive circuit provides circuit signals to the pixel circuit.
The operation process of the display panel at least includes a power-on stage and a display stage sequentially. The power-on stage at least includes a first phase and a second phase sequentially. The power-on stage contains multiple consecutive frames. For at least part of a frame at the power-on stage, the peripheral drive circuit provides a first control signal to a control terminal of the first reset module, and the first reset module is turned on. The peripheral drive circuit provides a second control signal to a control terminal of the compensation module, and the compensation module is turned on. In the second phase, the peripheral drive circuit provides a first power supply voltage to the first power supply voltage signal terminal and/or provides a second power supply voltage to the second power supply voltage signal terminal.
A second aspect of the present disclosure provides a display device that includes the display panel illustrated above in the first aspect. Compared with existing technologies, the display panel and display device provided by the present disclosure at least achieve the following beneficial effects:
The display panel includes a pixel circuit and a light-emitting element that are electrically connected. The pixel circuit is used to control light emission of the light-emitting element. The pixel circuit at least includes a drive module, a first reset module, and a compensation module. The drive module and the light-emitting element are connected in series between first and the second power supply voltage signal terminals. The drive module is used to generate a drive current to drive the light-emitting element to emit light. The first reset module is electrically connected to a control terminal of the drive module and used to initialize the control terminal of the drive module. The compensation module is connected in series between the control terminal of the drive module and an output terminal of the drive module to compensate the voltage of the control terminal of the drive module. The compensation module is used to detect and compensate for the deviation of the threshold voltage of the drive module, and provide a compensated threshold voltage deviation to the drive module to achieve threshold compensation for the drive module. The drive module and light-emitting element are connected in series between the first and second power supply voltage signal terminals. When the pixel circuit drives the light-emitting element electrically connected to it to emit light, the conductive path used is through the first power supply voltage signal terminal, the drive module, the light-emitting element, and the second power supply voltage signal terminal. The drive module generates a drive current that drives the light-emitting element and makes the light-emitting element to emit light. A peripheral drive circuit of the present disclosure provides circuit signals to the pixel circuit. Since a first terminal of the drive module is connected to a first power supply voltage of the first power supply voltage signal terminal when last images are displayed, positive charges accumulate at the first terminal of the drive module. These charges are stored in parasitic capacitors. When the first control signal controls the first reset module to turn on and the second control signal controls the compensation module to turn on, since the Vgs of the drive module is smaller than Vth, the drive module turns on. At the same time, the remaining charges are released until the drive module is turned off. Subsequently, at the beginning of the display stage, since the residual charges have been released at the power-on stage, the light-emitting element does not flicker.
Any product implementing the present disclosure does not necessarily need to achieve all the above-mentioned technical effects at the same time.
Other features of the present disclosure and its advantages will become apparent from the following detailed description of exemplary embodiments of the present disclosure with reference to the accompanying drawings.
The operation process of the display panel 100 at least includes a power-on stage T1 and a display stage T2 in sequence. The power-on stage T1 at least includes a first phase T11 and a second phase T12 in sequence. The power-on stage T1 contains consecutive frames. For at least some frames of the power-on stage T1, the peripheral drive circuit 30 provides a first control signal S1 to a control terminal of the first reset module 102. The first reset module 102 turns on. The peripheral drive circuit 30 provides a second control signal S2 to a control terminal of the compensation module 103. The compensation module 103 turns on. In the second phase T12, the peripheral drive circuit 30 provides a first power supply voltage VPvdd to the first power supply voltage signal terminal PVDD and/or provides a second power supply voltage VPvee to the second power supply voltage signal terminal PVEE. In
In some cases, the display panel 100 is an organic light-emitting display panel. In some other cases, the display panel 100 is a display panel that controls the drive module 101 in the pixel circuit 10 to provide a drive current for the light-emitting element 20 to emit light. In some cases, the light-emitting element 20 is an OLED. Alternatively, the light-emitting element 20 may be a micro-LED or sub-millimeter LED. The present disclosure does not limit the type of the light-emitting element 20. In descriptions below, the display panel 100 is an OLED display panel exemplarily.
Optionally, the display panel 100 includes sub-pixels 00 that are arranged in an array. That is, the sub-pixels 00 are arranged along the first direction X to form rows of sub-pixels 00, and the rows of the sub-pixels 00 are arranged along the second direction Y. The sub-pixels 00 are arranged along the second direction Y to form columns of the sub-pixels 00, and the columns of the sub-pixels 00 are arranged along the first direction X. As such, an array structure is formed by the sub-pixels 00. The first direction X and second direction Y intersects or are perpendicular to each other in a plane parallel to the plane where the display panel 100 is located. Alternatively, the sub-pixels 00 may also be arranged in other ways.
Optionally, the sub-pixel 00 includes the pixel circuit 10 and light-emitting element 20 that are electrically connected. The pixel circuit 10 is used to control the light-emitting element 20 to emit light. Since the light-emitting element 20 in the OLED display panel 100 is generally an OLED, and an OLED is a current-driven device, a corresponding pixel circuit 10 is needed to provide a drive current for the light-emitting element 20 to emit light. The pixel circuit 10 at least includes the drive module 101, first reset module 102, and compensation module 103.
The drive module 101 and light-emitting element 20 are connected in series between the first and second power supply voltage signal terminals PVDD and PVEE. Optionally, the drive module 101 includes a drive transistor M0. A first electrode of the drive transistor M0 is electrically connected to the first power supply voltage signal terminal PVDD. A second electrode of the drive transistor M0 is electrically connected to the second power supply voltage signal terminal PVEE. The drive transistor M0 is used to generate a drive current. In some cases, the first electrode of the drive transistor M0 is the source of the drive transistor M0, and the second electrode of the drive transistor M0 is the drain of the drive transistor M0. In some other cases, the first electrode of the drive transistor M0 is the drain of the drive transistor M0, and the second electrode of the drive transistor M0 is the source of the drive transistor M0. With regard to the drive transistor M0, its gate is connected to a first node N1, its source is connected to a second node N2, and its drain is connected to a third node N3.
The first reset module 102 is electrically connected to the control terminal of the drive module 101, and used to initialize the control terminal of the drive module 101. When the first reset module 102 is turned on, the control terminal voltage of the drive module 101 is the reset signal VREF input by the first reset module 102. The control terminal of the drive module 101 is reset, and the drive module 101 may be turned on during threshold compensation. Optionally, the first reset module 102 includes a first transistor M1. The gate of the first transistor M1 inputs the first control signal S1. The first electrode of the first transistor M1 inputs the reset signal VREF. The second electrode of the first transistor M1 is electrically connected to the gate of the drive transistor M0. When the first transistor M1 is turned on, the reset signal VREF is input to the gate of the drive transistor M0. The gate of the drive transistor M0 is reset, which facilitates turning on the drive transistor M0 during threshold compensation.
The compensation module 103 is connected in series between the control terminal of the drive module 101 and the second terminal of the drive module 101 to compensate the voltage of the control terminal of the drive module 101. Optionally, the compensation module 103 is used to detect and compensate for the deviation of the threshold voltage of the drive transistor M0, and provide a compensated deviation of the threshold voltage to the drive transistor M0 to achieve threshold compensation for the drive transistor M0.
In
Optionally, the connection structure of the pixel circuit 10 is not limited to the above-mentioned structure and drive timing, and may include other connection structures and drive methods besides that illustrated above.
Referring to
E is the third control signal, and S is the fourth control signal that controls turn-on of a data write module (not shown in
The power-on stage T1 is before the display stage T2. The power-on stage T1 includes the first phase T11 and second phase T12 in sequence. In the first phase T11, the peripheral drive circuit 30 only provides the first control signal S1 to the control terminal of the first reset module 102 of the pixel circuit 10. Since the second node N2 is connected to the first power supply voltage VPvdd of the first power supply voltage signal terminal PVDD when the last image is displayed, positive charges accumulate at the second node N2. These charges are stored at parasitic capacitors. When the first control signal S1 controls the first reset module 102 to turn on and the second control signal S2 controls the compensation module 103 to turn on, because of Vgs<Vth for the drive transistor M0, the drive transistor M0 is turned on, and the remaining charges are released until the drive transistor M0 is turned off. Subsequently, in the early period of the display stage T2, the light-emitting element 20 does not flicker.
In
The first and second transistors M1 and M2 are N-type transistors exemplarily. Referring to
The first and second transistors M1 and M2 in
Optionally, the first and second transistors M1 and M2 are P-type transistors. When the first control signal S1 is a low voltage, the first reset module 102 is turned on. When the second control signal S2 is a low voltage, the compensation module 103 is turned on. The reset signal VREF is written into the control terminal of the drive module 101. Because of Vgs<Vth for the drive transistor M0, the drive transistor M0 is turned on. The second control signal S2 remains a low voltage. The compensation module 103 is turned on. Therefore, remaining charges are released to the storage capacitor Cst until the drive transistor M0 is turned off. At the power-on stage T1, residual charges of previous display images have been released. As such, there is no flickering problem at the beginning of the display stage T2.
During the period of at least part of frames at the power-on stage T1, the first control signal S1 maintains an effective voltage, and the second control signal S2 maintains an effective voltage. Then during this period of at least part of frames at the power-on stage T1, it is equivalent to all pixel rows performing electrostatic discharge at the same time. It takes less time than electrostatic discharge pixel row by pixel row, and has high electrostatic discharge efficiency. For example, a display panel consists of 2000 rows of pixels. If electrostatic discharge is performed row by row, the total duration of electrostatic discharge is kl. When the first and second control signals S1 and S2 maintain effective voltages, respectively, all 2000 pixel rows undergo electrostatic discharge simultaneously. The total time of electrostatic discharge is only k1/2000. The time of electrostatic discharge is greatly shortened. The efficiency of electrostatic discharge is improved.
The first and second transistors M1 and M2 are N-type transistors exemplarily. In
In some cases, the display stage T2 may directly follow the consecutive n frames. Alternatively, the display stage T2 may not directly follow the consecutive n frames. The purpose is to release static electricity of previous display images at the power-on stage T1 and prevent flickering in the early period of the display stage T2.
As shown in
Electrostatic discharge is performed at the power-on stage T1, preventing the light-emitting element 20 from flickering in the early period of the display stage T2. Further, the first control signal S1 of the i-th frame maintains an effective voltage, and the second control signal S2 maintains a non-effective voltage. The first and second control signals S1 and S2 of the i+1th frame maintain effective voltages, which may reduce the load. If the first and second control signals S1 and S2 simultaneously control the first reset module 102 and compensation module 103 to turn on, it is equivalent to releasing charges of storage capacitors of the first node N1 at the same time and residual charges of parasitic capacitors of the second node N2 and third node N3. In the present disclosure, the first control signal S1 controls the first reset module 102 to turn on, and then the second control signal S2 controls the compensation module 103 to turn on. As such, only charges of storage capacitors of the first node N1 are released at first. Then remaining charges at the second node N2 and third node N3 are released. Load problems after turning on all pixel rows at the same time may be reduced.
Referring to
The first and second transistors M1 and M2 are N-type transistors exemplarily. In
Optionally, when the first and second transistors M1 and M2 are P-type transistors, the first control signal S1 is a pulse signal, the effective pulse is a low voltage, and the second control signal S2 may maintain a low voltage.
At the power-on stage T1, the first control signal S1 is a pulse signal. Electrostatic discharge is performed at the first node N1 pixel row by pixel row. As such, the instantaneous load of the reset signal VREF is relatively small. Because at the subsequent display stage T2, the reset signal VREF is transmitted pixel row by pixel row, it does not require big load capacity. If at the power-on stage T1, electrostatic discharge is performed at the first nodes N1 of all pixel rows at the same time, the reset signal VREF requires a big capacity. The reset signal VREF needs to occupy a large space at the drive chip IC.
Referring to
At the power-on stage T1, the effective pulse width of the first control signal S1 is equal to that of the first display control signal 3.
At the power-on stage T1, the effective pulse width of the first control signal S1 is equal to that of the first display control signal 3. The first control signals S1 provided by the peripheral drive circuit 30 are the same. There is no need to switch or change the first control signal S1 at the power-on stage T1 and the first display control signal 3 at the display stage T2. It may lower the work pressure on the drive chip IC and also reduce the power consumption.
In
Optionally, the effective pulses of the first and second pulse signals 1 and 2 at least partially overlap. After the effective pulse of the first pulse signal 1 is transmitted to the first reset module 102, the first reset module 102 is turned on. Electrostatic discharge is performed at the first node N1. When the effective pulse of the first pulse signal 1 has not stopped, the effective pulse of the second pulse signal 2 is transmitted to the compensation module 103. The compensation module 103 is turned on. Electrostatic discharge is conducted at the second node N2 and third node N3. It prevents the light-emitting element 20 from flickering in the early period of the display stage T2.
Optionally at the power-on stage T1, both the first and second control signals S1 and S2 are pulse signals. Electrostatic discharge is performed at the first node N1, second node N2, and third node N3 pixel row by pixel row. As such, the instantaneous load of the reset signal VREF is relatively small. Because at the subsequent display stage T2, the reset signal VREF is transmitted pixel row by pixel row, large load capacity is not needed. If at the power-on stage T1, electrostatic discharge is performed at the first nodes N1 of all pixel rows at the same time, the reset signal VREF may require a large load capacity. The reset signal VREF may need to occupy a big space at the drive chip IC. Arranging a high voltage only when there is an effective pulse, while arranging a low voltage when there is a non-effective pulse. Power consumption during periods of non-effective pulses may be saved.
The start time of the effective pulse of the second pulse signal 2 is located between the start time and end time of the effective pulse of the first pulse signal 1. First, the first reset module 102 is turned on through the first control signal S1. Then, the compensation module 103 is turned on through the second control signal S2. Only charges of storage capacitors at the first node N1 are released first. Then, remaining charges at the second node N2 and third node N3 are released. This reduces load issues when all pixel rows are turned on at the same time. If the first and second control signals S1 and S2 simultaneously control the first reset module 102 and compensation module 103 to turn on, charges of storage capacitors at the first node N1 need to be released at the same time, and residual charges of parasitic capacitors at the second and third nodes N2 and N3 also need to be released.
At the display stage T2, the peripheral drive circuit 30 provides a first display control signal 3 to the control terminal of the first reset module 102, and provides a second display control signal 4 to the control terminal of the compensation module 103. At the display stage T2, the time during which the effective pulse widths of the second and first display control signals 4 and 3 overlap is t2. It is arranged that t1=t2.
At the power-on stage T1, the effective pulses of the first and second pulse signals 1 and 2 overlap. The start time of the effective pulse of the second pulse signal 2 is located between the start time and end time of the effective pulse of the first pulse signal 1. The end time of the effective pulse of the second pulse signal 2 is located after the end time of the effective pulse of the first pulse signal 1. The end time of the effective pulse of the first pulse signal 1 is between the start time and end time of the effective pulse of the second pulse signal 2. The time when the effective pulse widths of the first and second pulse signals 1 and 2 overlap is t1.
At the display stage T2, the start time of the effective pulse of the second display control signal 4 is between the start time and end time of the effective pulse of the first display control signal 3. The end time of the effective pulse of the first display control signal 3 is between the start time and end time of the effective pulse of the second display control signal 4. The time during which the effective pulse widths of the second and first display control signals 4 and 3 overlap is t2.
It is arranged that t1=t2. The first display control signal 3 provided by the peripheral drive circuit 30 and the first pulse signal 1 are the same. The second display control signal 4 provided by the peripheral drive circuit 30 and the second pulse signal 2 are the same. There is no need to change the first pulse signal 1 at the power-on stage T1 and the first display control signal 3 at the display stage T2. There is no need to change the second pulse signal 2 at the power-on stage T1 and the second display control signal 4 at the display stage T2. It may lower the work pressure of the drive chip IC and reduce the power consumption.
At the display stage T2, the start time of the effective pulse of the second display control signal 4 is between the start time and end time of the effective pulse of the first display control signal 3. At the display stage T2, the first reset module 102 is first turned on through the first display control signal 3. Then, the compensation module 103 is turned on through the second display control signal 4. That is, the first node N1 is reset first, and then the second node N2 and third node N3 are reset. It may reduce the load problem after all pixel rows are turned on at the same time. If the first and second display control signals 3 and 4 simultaneously control the first reset module 102 and compensation module 103 to turn on, it is needed to reset the first node N1, second node N2, and third node N3 at the same time.
In
On the one hand, at the power-on stage T1, the first and second control signals S1 and S2 are both pulse signals. As such, electrostatic discharge may be performed at the first node N1, second node N2, and third node N3 pixel row by pixel row. The instantaneous load of the reset signal VREF is relatively small. Because at the subsequent display stage T2, the reset signal VREF is transmitted pixel row by pixel row, a large load capacity is not needed. If at the power-on stage T1, electrostatic discharge is performed at the first nodes N1 of all pixel rows at the same time, the reset signal VREF requires a large load capacity. The reset signal VREF needs to occupy a big space at the drive chip IC. A high voltage is provided only with the effective pulse, and a low voltage is provided with a non-effective pulse. Power consumption may be saved during the period of non-effective pulses.
On the other hand, at each frame of the power-on stage T1, the start time of the effective pulse of the second pulse signal 2 is located after the end time of the effective pulse of the first pulse signal 1. First, the first reset module 102 is turned on through the first control signal S1. Then, the compensation module 103 is turned on through the second control signal S2. Thus, only charges of the storage capacitor at the first node N1 are released first, and then remaining charges at the second node N2 and third node N3 are released. The load problem after turning on all pixel rows at the same time is reduced. If the first and second control signals S1 and S2 simultaneously control the first reset module 102 and compensation module 103 to turn on, it is needed to simultaneously release charges of the storage capacitor of the first node N1 and residual charges of parasitic capacitors of the second node N2 and third node N3.
Referring to
The pulse width of the first pulse signal 1 at the power-on stage T1 is equal to the pulse width of the first display control signal 3 at the display stage T2.
The pulse width of the second pulse signal 2 is equal to the pulse width of the second display control signal 4 at the display stage T2.
At the display stage T2, when one frame ends and the next frame starts, the drive module 101 also needs to be reset. The peripheral drive circuit 30 inputs the first display control signal 3 to the control terminal of the first reset module 102, and provides the second display control signal 4 to the control terminal of the compensation module 103. The first and second display control signals 3 and 4 are pulse signals. It ensures that the first reset module 102 and compensation module 103 are turned on when the pulse signal is a high voltage, and the control terminal, first terminal, and second terminal of the drive module 101 are reset.
Optionally, the effective pulse width of the first pulse signal 1 at the power-on stage T1 is equal to the pulse width of the first display control signal 3 at the display stage T2. The pulse width of the second pulse signal 2 is equal to the pulse width of the second display control signal 4 at the display stage T2. As such, the first pulse signal 1 and first display control signal 3 provided by the peripheral drive circuit 30 are the same. The second pulse signal 2 and the second display control signal 4 are the same. There is no need to change the first pulse signal 1 at the power-on stage T1 and the first display control signal 3 at the display stage T2. There is no need to change the second pulse signal 2 at the power-on stage T1 and the second display control signal 4 in the display stage T2. The work pressure on the drive chip IC is lowered and the power consumption is reduced.
At the display stage T2, the first reset module 102 is turned on through the first display control signal 3 first. Then the compensation module 103 is turned on through the second display control signal 4. Thus, the first node N1 is reset first. Then the second node N2 and third node N3 are reset. It may reduce the load problem when turning on all pixel rows at the same time. If the first and second display control signals 3 and 4 simultaneously control the first reset module 102 and compensation module 103 to turn on, it is needed to reset the first node N1, second node N2, and third node N3 at the same time.
Optionally, the pixel circuit 10 is an 8T1C circuit. At the power-on stage, the peripheral drive circuit 30 transmits the fifth control signal SP to the control terminal of the bias module 106. The bias module 106 is turned on. A first terminal of the bias module 106 is electrically connected to the bias voltage DVH. A second terminal of the bias module 106 is electrically connected to the output terminal of the data write module 104 and the second node N2. The bias voltage DVH is written into the second node N2. Since the first control signal S1 controls the drive transistor M0 to turn on and the second control signal S2 controls the compensation module 103 to turn on, residual charges from previous display images may be released through the bias voltage DVH. That is, static charges at the second node N2 and third node N3 are removed.
At the power-on stage T1, when the bias module 106 is on, the data write module 104 is off. No data needs to be written at the power-on stage T1. Turning off the data write module 104 may reduce power consumption.
In addition at the display stage, the peripheral drive circuit 30 transmits the fifth control signal SP to the control terminal of the bias module 106. The bias module 106 is turned on. The bias module 106 is controlled to write the bias voltage DVH into the first terminal of the drive module 101 during part of the operation time of the pixel circuit 10. It may adjust the bias state of the drive module 101, improve the threshold drift problem of the drive module 101, and improve the display effect. At the display stage, the operation time of the bias module 106 is not limited, and only needs to be before the light-emitting element 20 emits light.
Optionally, the bias voltage DVH is provided by a bias signal line (not shown) at the display panel 100. Alternatively, the bias voltage DVH may also reuse certain drive signals in the pixel circuit 10, such as reusing the data signal DATA to achieve bias adjustment or when adjusting the bias voltage of the current row, reusing the data signal DATA of the next row to adjust the bias voltage of the drive module 101 of the current row. Optionally, the dynamic adjustment of the second power supply voltage VPvee and the bias voltage DVH may be directly performed through the second power supply voltage VPvee line (not shown) that supplies the second power supply voltage VPvee and the bias voltage signal line that supplies the bias voltage DVH. For example, the second power supply voltage VPvee line and the bias voltage signal line may be connected to the drive chip IC or a flexible circuit board bound on the display panel 100. The voltage signal input through the drive chip IC or the input pad of the flexible circuit board directly changes the dynamic values of the second power supply voltage VPvee and the bias voltage DVH. Alternatively, the bias voltage DVH may be dynamically adjusted by changing the on time of the bias module 106. For example, by controlling the maintenance time of the effective voltage of the fifth control signal SP, the value of the bias voltage DVH may also be adjusted to follow the dynamic change of the second power supply voltage VPvee. It may ensure the display quality of the display panel 100.
In the first phase T11, the peripheral drive circuit 30 only provides the first control signal S1 to the control terminal of the first reset module 102 of the pixel circuit 10. Electrostatic discharge is performed at the first node N1. The reset signal VREF is input to the control terminal of the drive module 101. The drive module 101 is turned on. The second control signal S2 is provided to the control terminal of the compensation module 103. The compensation module 103 is turned on. At the same time, the bias module 106 is turned on. Residual charges from previous display images are released through the bias voltage DVH, i.e., static charges at the second node N2 and the third node N3 are eliminated.
In
Referring to
Referring to
Optionally, if the start time of the reset signal VREF is after the start time of the first power supply voltage VPvdd, the first power supply voltage VPvdd may be written into the first terminal of the drive module 101. When the reset signal VREF is written into the control terminal of the drive module 101, it causes a voltage difference between the control terminal and input terminal of the drive module 101. In the second phase T12, the start time when the peripheral drive circuit 30 provides the reset signal VREF to the first terminal of the first reset module 102 is before the start time of the first power supply voltage VPvdd. It may prevent the first power supply voltage VPvdd from being written into the first terminal of the drive module 101 before resetting the drive module 101, and avoid creating a voltage difference between the first terminal and control terminal of the drive module 101. The voltage difference may cause a screen brighter.
Optional, the start time of the reset signal VREF is in the first phase T11. It may ensure that the start time of the reset signal VREF is before the start time of the first power supply voltage VPvdd.
As shown in
At the power-on stage, the voltage V1 of the first sub-reset signal VREF1 in the first phase T11 is smaller than the voltage V2 of the second sub-reset signal VREF2 in the second phase T12. It may reduce power consumption. Similarly, the third sub-reset signal VREF3 is smaller than the fourth sub-reset signal VREF4, which may also reduce power consumption. As it is arranged that V1=V3 and V2=V4, the first sub-reset signal VREF1, the second sub-reset signal VREF2, the third sub-reset signal VREF3, and the fourth sub-reset signal VREF4 form a alternation pattern. It may facilitate the drive chip IC providing reset signals periodically and dynamically.
At the power-on stage T1, the light-emitting control module 105 and data write module 104 are turned off. At the display stage, the peripheral drive circuit 30 provides the third control signal E to a control terminal of the light-emitting control module 105 row by row. The third control signal E is a non-effective voltage. The peripheral drive circuit 30 provides the fourth control signal S to the control terminal of the data write module 104. The fourth control signal S is a non-effective voltage. The data write module 104 and light-emitting control module 105 are turned off.
Optionally, the first terminal of the data write module 104 is electrically connected to the data signal DATA. The second terminal of the data write module 104 is electrically connected to the first terminal of the drive module 101. The data write module 104 is used to provide the data signal DATA to the drive module 101. Optionally, the data write module 104 includes a third transistor M3. The gate of the third transistor M3 is connected to the fourth control signal S. The source of the third transistor M3 is connected to the data signal DATA. The drain of the third transistor M3 is electrically connected to the first terminal of the drive module 101 (the source of the drive transistor M0 is the second node N2). The pixel circuit 10 includes a data write phase at the display stage T2. The peripheral drive circuit provides the fourth control signal S to the control terminal of the data write module 104. The fourth control signal S is an effective voltage. The data write module 104 is turned on. The data signal DATA on the data line may be transmitted to the drive module 101.
Optionally, the light-emitting control module 105 includes a first light-emitting control module 1051 and a second light-emitting control module 1052. A first terminal of the first light-emitting control module 1051 is electrically connected to the first power supply voltage signal terminal PVDD. A second terminal of the first light-emitting control module 1051 is electrically connected to the first terminal of the drive module 101. A first terminal of the second light-emitting control module 1052 is electrically connected to the second terminal of the drive module 101. A second terminal of the second light-emitting control module 1052 is electrically connected to the light-emitting element 20. Optionally, the first light-emitting control module 1051 includes a fourth transistor M4. The gate of the fourth transistor M4 is connected to a third control signal E. The source of the fourth transistor M4 is connected to the first power supply voltage signal terminal PVDD. The drain of the fourth transistor M4 is connected to the first terminal of the drive module 101.
The pixel circuit 10 includes the light-emitting phase at the display stage T2. The peripheral drive circuit 30 transmits the third control signal E to the control terminal of the light-emitting control module 105 row by row. The third control signal E is an effective voltage. The light-emitting control module 105 is turned on, i.e., the first and second light-emitting control modules 1051 and 1052 are turned on. A conductive circuit is formed between the first power supply voltage VPvdd and second power supply voltage VPvee. The light-emitting element 20 emits light. The first and second light-emitting control modules 1051 and 1052 cooperate to provide a drive current to the light-emitting element 20. The first light-emitting control module 1051 is turned on. A positive voltage signal provided by the first power supply voltage VPvdd is supplied to the first terminal of the drive module 101. The drive module 101 is turned on under the control of its gate voltage, and provides a voltage signal at the first terminal of the drive module 101 to the second terminal of the drive module 101. The second light-emitting control module 1052 is turned on, providing the voltage signal at the second terminal of the drive module 101 to the light-emitting element 20. As such, a drive current flows through the light-emitting element 20 to control the light-emitting element 20 to emit light.
When the compensation module 103 is turned on, threshold compensation may be performed at the drive module 101. When the first reset module 102 is turned on, the control terminal voltage of the drive module 101 is the reset signal VREF. The control terminal of the drive module 101 is reset. It may facilitate turning on the drive module 101 during threshold compensation.
At the power-on stage T1, the light-emitting control module 105 and data write module 104 are turned off. At the display stage T2, the third control signal E provided by the peripheral drive circuit 30 to the control terminal of the light-emitting control module 105 is an effective voltage. The fourth control signal S provided to the control terminal of the data write module 104 is an effective level. The light-emitting control module 105 and data write module 104 are turned on. Thus, there is no need to provide control signals for controlling the light-emitting control module 105 and data write module 104 to turn on at the power-on stage T1. It may reduce power consumption of the display panel 100.
Referring to
Optionally, the pixel circuit 10 is a 7T1C circuit. At the display stage T2, when the second reset module 107 is turned on, the anode voltage of the light-emitting element 20 is a reset signal VREF2. The reset signal VREF2 initializes the anode of the light-emitting element 20. It may improve the residue of the data signal DATA of a previous frame, improve the afterimage issue, and improve the display effect of the display panel. Optionally, the second reset module 107 includes a sixth transistor M6. The gate of the sixth transistor M6 is connected to the reset signal VREF2. The source of the sixth transistor M6 is electrically connected to the output terminal of the second light-emitting control module 1052. The drain of the sixth transistor M6 is electrically connected to the anode of the light-emitting element 20.
At the power-on stage T1, the second reset module 107 is turned off. In the reset phase of the display stage T2, the second reset module 107 is turned on. Thus, there is no need to provide a control signal to control the second reset module 107 to turn on at the power-on stage T1. It may reduce the power consumption at the power-on stage T1.
Referring to
In the third phase T31, the peripheral drive circuit 30 provides the first power supply voltage VPvdd to the first power supply voltage signal terminal PVDD and/or provides the second power supply voltage VPvee to the second power supply voltage signal terminal PVEE. In the fourth phase T32, the peripheral drive circuit 30 stops providing the first power supply voltage VPvdd to the first power supply voltage signal terminal PVDD and/or providing the second power supply voltage VPvee to the second power supply voltage signal terminal PVEE.
In both the third and fourth phases T31 and T32, the peripheral drive circuit 30 provides the first control signal S1 to the control terminal of the first reset module 102. The peripheral drive circuit 30 provides the second control signal S2 to the control terminal of the compensation module 103.
The power-off stage T3 is configured after the display stage T2 and includes the third phase T31 and fourth phase T32 in sequence. In the third phase T31 of the power-off stage T3, the first power supply voltage VPvdd and second power supply voltage VPvee are maintained for a certain period of time. In the fourth phase T32, the input of the first power supply voltage VPvdd and/or the second power supply voltage VPvee is stopped.
For at least part of certain frames throughout the power-off stage T3, the peripheral drive circuit 30 only provides the first control signal S1 to the control terminal of the first reset module 102 of the pixel circuit 10. At this time, the reset signal VREF is input to the control terminal of the drive module 101. The first node N1 is electrostatically discharged. The drive module 101 is turned on. The second control signal S2 is provided to the control terminal of the compensation module 103. The compensation module 103 is turned on. Electrostatic discharge is performed at the second node N2 and third node N3. Thus, the first node N1, second node N2, and third node N3 are electrostatically discharged at the power-off stage. At the next power-on stage T1, further electrostatic discharge is carried out. Therefore, the light-emitting element 20 does not flicker.
The display panel and display device provided by the present disclosure at least achieve the following beneficial effects:
The display panel includes a pixel circuit and a light-emitting element that are electrically connected. The pixel circuit is used to control the light-emitting element to emit light. The pixel circuit at least includes a drive module, a first reset module, and a compensation module. The drive module and light-emitting element are connected in series between a first and a second power supply voltage signal terminal. The drive module is used to generate a drive current to drive the light-emitting element to emit light. The first reset module is electrically connected to a control terminal of the drive module and used to initialize the control terminal of the drive module. The compensation module is connected in series between the control terminal of the drive module and an output terminal of the drive module to compensate the voltage of the control terminal of the drive module. The compensation module is used to detect and compensate for the deviation of the threshold voltage of the drive module, and provide a compensated threshold voltage deviation to the drive module to achieve threshold compensation for the drive module. The drive module and light-emitting element are connected in series between the first and second power supply voltage signal terminals. When the pixel circuit drives the light-emitting element electrically connected to it to emit light, through a conductive path via the first power supply voltage signal terminal, the drive module, the light-emitting element, and the second power supply voltage signal terminal, the drive module generates a drive current that drives the light-emitting element to emit light. The light-emitting effect of the light-emitting element is achieved. The peripheral drive circuit provides a circuit signal to the pixel circuit. Since the first terminal of the drive module used with last display images is connected to the first power supply voltage of the first power supply voltage signal terminal, positive charges accumulate at the first terminal of the drive module. These charges are stored at parasitic capacitors. When a first control signal controls the first reset module to turn on and a second control signal controls the compensation module to turn on, due to Vgs<Vth at the drive module, the drive module is turned on and simultaneously remaining charges are released until the drive module is turned off. Then in the early period of the display stage, as residual charges have been released at the power-on stage, the light-emitting element does not flicker.
The embodiments disclosed herein are exemplary only. Other applications, advantages, alternations, modifications, or equivalents to the disclosed embodiments are obvious to those skilled in the art and are intended to be encompassed within the scope of the present disclosure. The scope of the present disclosure is defined by the appended claims.
Number | Date | Country | Kind |
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202310962955.4 | Jul 2023 | CN | national |