Pixel driving compensation circuit, driving compensation method therefor and display device

The present application is based upon International Application No. PCT/CN2018/071370, filed on Jan. 4, 2018, which claims the priority to the Chinese Patent Application No. 201710308784.8, entitled “PIXEL DRIVING COMPENSATION CIRCUIT AND DRIVING COMPENSATION METHOD THEREOF, DISPLAY DEVICE”, filed on May 4, 2017, the entire contents of which are hereby incorporated by reference.

The present disclosure relates to the field of display technologies, and in particular, to a pixel driving compensation circuit, a driving compensation method thereof, and a display device.

OLED (Organic Light Emitting Diode) display, as a current-type light emitting device, is increasingly used in high-performance display fields due to its self-luminous, fast response, wide viewing angle, and ability to be fabricated on flexible substrates. According to the driving manner, the OLED can be classified into PMOLED (Passive Matrix Driving OLED) and AMOLED (Active Matrix Driving OLED). As the AMOLED display has the advantages of low manufacturing cost, high response speed, power saving, DC drive for portable equipment, wide operating temperature range and so on, the AMOLED display is expected to become a next-generation flat panel display replacing LCD (Liquid Crystal Display).

Existing OLED displays can use external compensation techniques to enhance display effect, such as obtaining drive current output by a driving transistor through a detection circuit and comparing it with the actual required reference current to achieve compensation. However, due to limitation of processes, many pixel defects may occur in the manufacturing process of the OLED display panel, and once a defect occurs in a certain sub-pixel, detection accuracy of other sub-pixels is also affected, which brings some difficulties to the compensation of the pixel, thus easily causing display abnormality.

According to an aspect of the present disclosure, there is provided a pixel driving compensation circuit configured to detect and compensate a driving current of a sub-pixel in a pixel unit. The pixel unit includes first to third sub-pixels and the first to third sub-pixels respectively include first to third driving transistors. The pixel driving compensation circuit includes a first switching sub-circuit. The first switching circuit is configured to be turned on in a first period in response to a first strobe signal to transmit a driving current output from the first driving transistor to a first detection line. The pixel driving compensation circuit includes a second switching sub-circuit. The second switching circuit is configured to be turned on in a second period in response to a second strobe signal to transmit a driving current output from the second driving transistor to a first detection line. The pixel driving compensation circuit includes a third switching sub-circuit. The third switching circuit is configured to be turned on in the first period in response to the first strobe signal to transmit a driving current output from the third driving transistor to a second detection line.

In an exemplary arrangement of the present disclosure, the pixel unit further includes a fourth sub-pixel and the fourth sub-pixel includes a fourth driving transistor. The pixel driving compensation circuit further includes a fourth switching sub-circuit. The fourth switching circuit is configured to be turned on in the second period in response to the second strobe signal to transmit a driving current output from the fourth driving transistor to the second detection line.

In an exemplary arrangement of the present disclosure, the pixel driving compensation circuit further includes a first reset sub-circuit configured to be turned on in response to a third strobe signal to transmit a voltage signal of the first detection line to an output terminal of the first driving transistor. The pixel driving compensation circuit further includes a second reset sub-circuit configured to be turned on in response to the third strobe signal to transmit the voltage signal of the first detection line to an output terminal of the second driving transistor. The pixel driving compensation circuit further includes a third reset sub-circuit configured to be turned on in response to the third strobe signal to transmit a voltage signal of the second detection line to an output terminal of the third driving transistor.

In an exemplary arrangement of the present disclosure, the pixel driving compensation circuit further includes a fourth reset sub-circuit configured to be turned on in response to the third strobe signal to transmit the voltage signal of the second detection line to an output terminal of the fourth driving transistor.

In an exemplary arrangement of the present disclosure, all of the switching sub-circuits and the reset sub-circuits are N-type thin film transistors or are P-type thin film transistors.

In an exemplary arrangement of the present disclosure, the first detection line and the second detection line are further connected to a driving chip.

In an exemplary arrangement of the present disclosure, the first to fourth sub-pixels include a red sub-pixel, a green sub-pixel, a blue sub-pixel, and a white sub-pixel.

According to another aspect of the present disclosure, there is provided a driving compensation method based on the pixel driving compensation circuit described above, for detecting and compensating a driving current of a sub-pixel in a pixel unit. The driving compensation method includes turning on a first switching sub-circuit and a third switching sub-circuit in a first period by the first strobe signal, and turning off a second switching sub-circuit in the first period by the second strobe signal. As such, a driving current output from a first driving transistor is transmitted to a first detection line through the first switching sub-circuit and fed back to a driving module, and a driving current output from a third driving transistor is transmitted to a second detection line through the third switching sub-circuit and fed back to the driving module. The driving module respectively reads the driving current output from the first driving transistor and the driving current output from the third driving transistor, and calculates a compensation voltage of a first sub-pixel and a compensation voltage of a third sub-pixel. The method includes turning off the first switching sub-circuit and the third switching sub-circuit in a second period by the first strobe signal, and turning on the second switching sub-circuit in the second period by the second strobe signal. As such, a driving current output by a second driving transistor is transmitted to the first detection line through the second switching sub-circuit and fed back to the driving module, and the driving module reads the driving current output by the second driving transistor and calculates a compensation voltage of a second sub-pixel.

In an exemplary arrangement of the present disclosure, in a case where the pixel unit includes a fourth sub-pixel, the driving compensation method further includes turning off a fourth switching sub-circuit in the first period by the second strobe signal when turning on the first switching sub-circuit and the third switching sub-circuit in the first period by the first strobe signal, and turning off the second switching sub-circuit in the first period by the second strobe signal. The driving compensation method further includes turning on the fourth switching sub-circuit in the second period by the second strobe signal when turning off the first switching sub-circuit and the third switching sub-circuit in the second period by the first strobe signal, and turning on the second switching sub-circuit in the second period by the second strobe signal. As such, a driving current output by a fourth driving transistor is transmitted to the second detection line through the fourth switching sub-circuit and fed back to the driving module, and the driving module reads the driving current output by the fourth driving transistor and calculates a compensation voltage of the fourth sub-pixel.

In an exemplary arrangement of the present disclosure, in a compensation phase, a high level period of a first data signal of the first sub-pixel and a third data signal of the third sub-pixel is the same as a high level period of the first strobe signal. A high level period of a second data signal of the second sub-pixel and a fourth data signal of the fourth sub-pixel is the same as a high level period of the second strobe signal. Or, a low level period of the first data signal of the first sub-pixel and the third data signal of the third sub-pixel is the same as a low-level period of the first strobe signal. A low level period of the second data signal of the second sub-pixel and the fourth data signal of the fourth sub-pixel is the same as a low level period of the second strobe signal.

In an exemplary arrangement of the present disclosure, the driving compensation method further includes turning on the first to third switching sub-circuits through the first strobe signal and the second strobe signal, and transmitting the voltage signal of the first detection line to the output terminals of the first driving transistor and the second driving transistor respectively and transmitting the voltage signal of the second detection line to the output terminal of the third driving transistor.

In an exemplary arrangement of the present disclosure, the driving compensation method further includes

turning on the fourth switching sub-circuit by the second strobe signal, and transmitting the voltage signal of the second detection line to the output terminal of the fourth driving transistor.

In an exemplary arrangement of the present disclosure, in a case where the pixel driving compensation circuit further includes first to third reset sub-circuits, the driving compensation method further includes turning on the first to third reset sub-circuits respectively by a third strobe signal, transmitting the voltage signal of the first detection line to the output terminals of the first driving transistor and the second driving transistor respectively and transmitting the voltage signal of the second detection line to the output terminal of the third driving transistor.

The first switching sub-circuit and the first reset sub-circuit are simultaneously turned on, the second switching sub-circuit and the second reset sub-circuit are simultaneously turned on, and the third switching sub-circuit and the third reset sub-circuit are simultaneously turned on.

In an exemplary arrangement of the present disclosure, in a case where the pixel driving compensation circuit further includes a fourth reset sub-circuit, the driving compensation method further includes turning on the fourth reset sub-circuit by a third strobe signal, and transmitting a voltage signal of the second detection line to an output terminal of the fourth driving transistor.

The fourth switching sub-circuit and the fourth reset sub-circuit are simultaneously turned on.

According to an aspect of the present disclosure, there is provided a display device, including the above-described pixel driving compensation circuit.

It is to be understood that the above general description and the following detailed description are merely exemplary and explanatory and should not be construed as limiting of the present disclosure.

The accompanying drawings, which are incorporated in the specification and constitute a part of the specification, show exemplary arrangements of the present disclosure. The drawings along with the specification explain the principles of the present disclosure. It is apparent that the drawings in the following description show only some of the embodiments of the present disclosure, and other drawings may be obtained according to these drawings by those skilled in the art without creationary labor.

FIG. 1 schematically illustrates a schematic diagram 1 of a pixel driving compensation circuit in an exemplary arrangement of the present disclosure;

FIG. 2 schematically illustrates a schematic diagram 2 of a pixel driving compensation circuit in an exemplary arrangement of the present disclosure;

FIG. 3 schematically illustrates a circuit connection relationship of sub-pixels in an exemplary arrangement of the present disclosure;

FIG. 4 schematically illustrates a flow chart 1 of a pixel driving compensation method in an exemplary arrangement of the present disclosure;

FIG. 5 schematically illustrates a flow chart 2 of a pixel driving compensation method in an exemplary arrangement of the present disclosure; and

FIG. 6 schematically illustrates a driving timing diagram in an exemplary arrangement of the present disclosure.

Example arrangements will now be described more fully with reference to the accompanying drawings. However, the arrangements can be implemented in a variety of forms and should not be construed as being limited to the examples set forth herein; rather, these arrangements are provided so that this disclosure will be more complete so as to convey the idea of the exemplary arrangements to those skilled in this art. The described features, structures, or characteristics may be combined in one or more arrangements in any suitable manner.

In addition, the drawings are merely schematic representations of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and the repeated description thereof will be omitted. Some of the block diagrams shown in the figures are functional entities and do not necessarily correspond to physically or logically separate entities. These functional entities may be implemented in software, or implemented in one or more hardware modules or integrated circuits, or implemented in different networks and/or processor devices and/or microcontroller devices.

The exemplary arrangement provides a pixel driving compensation circuit, configured to detect and compensate a driving current of each sub-pixel in an OLED pixel unit. As shown in FIG. 1 , the OLED pixel unit may at least include a first sub-pixel 10 , a second sub-pixel 20 , and a third sub-pixel 30 . The first sub-pixel 10 may include a first driving transistor DT 1 , a first terminal of the driving transistor DT 1 receives a first voltage signal VDD, and a second terminal of the driving transistor DT 1 is connected to a first OLED lighting unit. The second sub-pixel 20 may include a second driving transistor DT 2 , a first terminal of the second driving transistor DT 2 receives the first voltage signal VDD, and a second terminal of the second driving transistor DT 2 is connected to a second OLED light emitting unit. The third sub-pixel 30 may include a third driving transistor DT 3 , a first terminal of the third driving transistor DT 3 receives the first voltage signal VDD, and a second terminal of the third driving transistor DT 3 is connected to a third OLED lighting unit.

Based on this, the OLED pixel driving compensation circuit may include a first switching sub-circuit ST 1 corresponding to the first sub-pixel 10 , a second switching sub-circuit ST 2 corresponding to the second sub-pixel 20 , and a third switching sub-circuit ST 3 corresponding to the third sub-pixel 30 .

The first switching sub-circuit ST 1 has a control terminal receiving a first strobe signal G 1 , a first terminal connected to an output terminal of the first driving transistor DT 1 , and a second terminal connected to a first detection line Sense 1 . The first switching sub-circuit ST 1 is configured to be turned on in a first period in response to the first strobe signal G 1 to transmit a driving current output by the first driving transistor DT 1 to the first detection line Sense 1 . Then, the driving current is fed back to a driving module. After reading the driving current, the driving module calculates a required compensation voltage of the first sub-pixel 10 , thus writing the compensation voltages to a first data signal Data- 1 to achieve compensation for the first sub-pixel 10 .

The second switching sub-circuit ST 2 has a control terminal receiving a second strobe signal G 2 , a first terminal connected to an output terminal of the second driving transistor DT 2 , and a second terminal connected to the first detection line Sense 1 . The second switching sub-circuit ST 2 is configured to be turned on in a second period in response to the second strobe signal G 2 , to transmit a driving current output by the second driving transistor DT 2 to the first detection line Sense 1 . Then, the driving current is fed back to the driving module. After reading the driving current, the driving module calculates a required compensation voltage of the second sub-pixel 20 , thus writing the compensation voltage to a second data signal Data- 2 to achieve compensation for the second sub-pixel 20 .

The third switching sub-circuit ST 3 has a control terminal receiving the first strobe signal G 1 , a first terminal connected to an output terminal of the third driving transistor DT 3 , and a second terminal connected to a second detection line Sense 2 . The third switching sub-circuit ST 3 is configured to be turned on in the first period in response to the first strobe signal G 1 , to transmit a driving current output by the third driving transistor DT 3 to the second detection line Sense 2 . Then, the driving current is fed back to the driving module. After reading the driving current, the driving module calculates a required compensation voltage of the third sub-pixel 30 , thus writing the compensation voltage to a third data signal Data- 3 to achieve compensation for the third sub-pixel 30 .

The first sub-pixel 10 , the second sub-pixel 20 , and the third sub-pixel 30 may respectively correspond to a red sub-pixel, a green sub-pixel, and a blue sub-pixel. Correspondingly, the first OLED light emitting unit, the second OLED light emitting unit, and the third OLED light emitting unit may respectively correspond to a red OLED light emitting unit, a green OLED light emitting unit, and a blue OLED light emitting unit.

In the pixel driving compensation circuit provided by the exemplary arrangement of the present disclosure, the first sub-pixel 10 and the second sub-pixel 20 share the same detection line, but the switching sub-circuits thereof are respectively controlled by different strobe signals to be turned on in different periods. The first sub-pixel 10 and the third sub-pixel 30 use different detection lines, but the switching sub-circuits thereof are controlled by the same strobe signal to be turned on in the same period. Based on the structure, the first sub-pixel 10 and the third sub-pixel 30 can respectively detect the driving current by using the first detection line Sense 1 and the second detection line Sense 2 in the same period, and feed back the detection results to the driving module instantly. After reading the driving currents of the first sub-pixel 10 and the third sub-pixel 30 , the driving module respectively calculates the required compensation voltages of the first and third sub-pixels 10 and 30 , thus respectively writing the compensation voltages of the first sub-pixel 10 and the third sub-pixel 30 to the first data signal Data- 1 and a third data signal Data- 3 to achieve the compensations for the first sub-pixel 10 and the third sub-pixel 30 . However, the second sub-pixel 20 can detect the driving current by using the first detection line Sense 1 in another period, and feed back the detection result to the driving module instantly. After reading the driving current of the second sub-pixel 20 , the driving module calculates the required compensation voltage of the second sub-pixel 20 , thus writing the compensation voltage of the second sub-pixel 20 to the second data signal Data- 2 to achieve the compensation for the second sub-pixel 20 . In this way, the pixel structure combined with the working timing of the strobe signal can not only effectively shorten the current detection time to provide a basis for subsequent real-time compensation, thus shortening the occupation time of external compensation, but also separate the sub-pixels from each other to avoid the effect of defects in other sub-pixels, thus preventing the newly added defects after compensation from affecting the display effect of the display screen. Based on this, the sub-pixels in the OLED pixel unit are isolated from each other by the coordination action of the strobe signal and the detection line, thus ensuring the accuracy of current detection and compensation of each sub-pixel, effectively avoiding the problem of display abnormality, and improving display effect

On the basis of this, as shown in FIG. 2 , the OLED pixel unit may further include a fourth sub-pixel 40 . The fourth sub-pixel 40 may include a fourth driving transistor DT 4 , a first terminal of the fourth driving transistor DT 4 receives the first voltage signal VDD, and a second terminal of the fourth driving transistor DT 4 is connected to the fourth OLED lighting unit.

Based on this, the OLED pixel driving compensation circuit may further include a fourth switching sub-circuit ST 4 corresponding to the fourth sub-pixel 40 .

The fourth switching sub-circuit ST 4 has a control terminal receiving the second strobe signal G 2 , a first terminal connected to the output terminal of the fourth driving transistor DT 4 , and a second terminal connected to the second detection line Sense 2 . The fourth switching sub-circuit ST 4 is configured to be turned on in response to the second strobe signal G 2 in the second period, to transmit a driving current output by the fourth driving transistor DT 4 to the second detection line Sense 2 . Then, the driving current is fed back to the driving module. After reading the driving current, the driving module calculates a required compensation voltage of the fourth sub-pixel 40 , thus writing the compensation voltage to a fourth data signal Data- 4 to achieve compensation for the fourth sub-pixel 40 .

The fourth sub-pixel 40 may be a white sub-pixel, and correspondingly, the fourth OLED light-emitting unit may be a white OLED light-emitting unit.

Based on the OLED pixel structure described above, the first sub-pixel 10 and the second sub-pixel 20 share the first detection line Sense 1 , the third sub-pixel 30 and the fourth sub-pixel 40 share the second detection line Sense 2 , the first sub-pixel 10 and the third sub-pixel 30 detect the driving current in the first period, and the second sub-pixel 20 and the fourth sub-pixel 40 detect the driving current in the second period. In this way, the detection line with a one-for-two structure (that is, two sub-pixels connected to the same detection line) provided by the exemplary arrangement can not only effectively shorten the current detection time to provide a basis for subsequent real-time compensation, thus shortening the occupation time of external compensation, but also separate different sub-pixels from each other to avoid distortion of the compensation signal caused by signal interference, thus effectively overcoming the display abnormality.

Considering that the function of the first detection line Sense 1 and the second detection line Sense 2 is to acquire the driving current output by the driving transistor and based on this to compensate the driving current of each sub-pixel, the first detection line Sense 1 and the second detection line Sense 2 are also connected to a driving chip.

In the example arrangement, referring to FIG. 1 and FIG. 2 , the pixel driving compensation circuit may further include a first reset sub-circuit RT 1 corresponding to the first sub-pixel 10 , having a control terminal connected to a third strobe signal G 3 , a first terminal connected to the first detection line Sense 1 , and a second terminal connected to the output terminal of the first driving transistor DT 1 , and configured to be turned on in response to the third strobe signal G 3 to transmit a voltage signal of the first detection line Sense 1 to an output terminal of the first driving transistor DT 1 . The pixel driving compensation circuit may further include a second reset sub-circuit RT 2 corresponding to the second sub-pixel 20 , having a control terminal connected to the third strobe signal G 3 , a first terminal connected to the first detection line Sense 1 , and a second terminal connected to the output terminal of the second driving transistor DT 2 , and configured to be turned on in response to the third strobe signal G 3 , to transmit a voltage signal of the first detection line Sense 1 to the output terminal of the second driving transistor DT 2 . The pixel driving compensation circuit may further include a third reset sub-circuit RT 3 corresponding to the third sub-pixel 30 , having a control terminal connected to the third strobe signal G 3 , a first terminal connected to the second detection line Sense 2 , and a second terminal connected to the output terminal of the third driving transistor DT 3 , and configured to be turned on in response to the third strobe signal G 3 , to transmit a voltage signal of the second detection line Sense 2 to the output terminal of the third driving transistor DT 3 . The pixel driving compensation circuit may further include a fourth reset sub-circuit RT 4 corresponding to the fourth sub-pixel 40 , having a control terminal connected to the third strobe signal G 3 , a first terminal connected to the second detection line Sense 2 , and a second terminal connected to the output terminal of the fourth driving transistor DT 4 , and configured to be turned on in response to the third strobe signal G 3 , to transmit a voltage signal of the second detection line Sense 2 to the output terminal of the fourth driving transistor DT 4 .

It should be noted that the respective reset sub-circuit and the above-mentioned respective switching sub-circuit may constitute a double-switch structure for improving the resetting capability of each sub-pixel. Thus, it can be known that the working periods of the reset sub-circuit and the switching sub-circuit constituting the double-switch structure should have overlapping portion, that is, in the reset phase, the level state of the third strobe signal G 3 should be consistent with the level states of the first strobe signal G 1 and the second strobe signal G 2 .

In the present exemplary arrangement, when the OLED pixel unit includes only three sub-pixels, only the first to third reset sub-circuits RT 1 to RT 3 and the first to third switching sub-circuits ST 1 to ST 3 are required to form three pairs of double-switch structures. When the OLED pixel unit includes four sub-pixels, the fourth reset sub-circuit RT 4 and the fourth switching sub-circuit ST 4 are further required to form a fourth pair of double-switch structure.

In this way, for any sub-pixel, the resetting capability can be increased by forming a double-switch structure by the switching sub-circuit and the reset sub-circuit inside of the sub-pixel. In the field of high-frequency display, the resetting ability of the conventional OLED display is weak, and thus the display effect is poor. By adopting the OLED pixel structure provided by the exemplary arrangement, the reset capability can be improved, thus meeting the requirement of high frequency display, and an OLED display with good display effect is obtained.

It should be noted that, based on the pixel driving compensation circuit described above, the control terminals of the driving transistors of the respective sub-pixels may also respectively be connected to the data signal terminals through control switches such as control transistors. Specifically, for the first sub-pixel 10 , the control terminal of the first driving transistor DT 1 is connected to a first control transistor T 1 . A control terminal of the first control transistor T 1 receives the control signal G 0 , a first terminal of the first control transistor T 1 receives the first data signal Data- 1 , and a second terminal of the first control transistor T 1 is connected to the control terminal of the first driving transistor DT 1 . For the second sub-pixel 20 , the control terminal of the second driving transistor DT 2 is connected to a second control transistor T 2 . A control terminal of the second control transistor T 2 receives the control signal G 0 , a first terminal of the second control transistor T 2 receives the second data signal Data- 2 , and a second terminal of the second control transistor T 2 is connected to the control terminal of the second driving transistor DT 2 . For the third sub-pixel 30 , the control terminal of the third driving transistor DT 3 is connected to a third control transistor T 3 . A control terminal of the third control transistor T 3 receives the control signal G 0 , a first terminal of the third control transistor T 3 receives the third data signal Data- 3 , and a second terminal of the third control transistor T 3 is connected to the control terminal of the third driving transistor DT 3 . For the fourth sub-pixel 40 , the control terminal of the fourth driving transistor DT 4 is connected to a fourth control transistor T 4 . A control terminal of the fourth control transistor T 4 receives the control signal G 0 , a first terminal of the fourth control transistor T 4 receives the fourth data signal Data- 4 , and a second terminal of the fourth control transistor T 4 is connected to the control terminal of the fourth driving transistor DT 4 .

In the example arrangement, the first to fourth switching sub-circuits ST 1 to ST 4 may be first to fourth switching transistors, and the first to fourth reset sub-circuits RT 1 to RT 4 may be first to fourth reset transistor. All of the transistors may be N-type thin film transistors or P-type thin film transistors.

Hereinafter, the sub-pixel connection relationship in the pixel driving compensation circuit will be exemplarily described with reference to FIG. 3 taking all of the switching sub-circuits/transistors as N-type thin film transistors as an example. The first sub-pixel is a red sub-pixel, and the first OLED light-emitting unit is a red light-emitting unit.

The red sub-pixel includes a first driving transistor DT 1 and a red OLED lighting unit connected to an output terminal of the first driving transistor DT 1 , and an input terminal of the first driving transistor DT 1 is connected to a first voltage signal VDD, such as a high level signal. The cathode of the red OLED light emitting unit is connected to a second voltage signal VSS, such as a low level signal. A control terminal of the first driving transistor DT 1 is connected to the first control transistor T 1 , and the first control transistor T 1 is used to transmit a data signal Data- 1 to the control terminal of the first driving transistor DT 1 in response to the control signal G 0 . The output terminal of the first driving transistor DT 1 is further connected to the first switching sub-circuit ST 1 and the first reset sub-circuit RT 1 , and the first switching sub-circuit ST 1 is used to transmit the current output by the first driving transistor DT 1 to the first detection line Sense 1 in response to the first strobe signal G 1 . However, the first resetting sub-circuit RT 1 is used to transmit the voltage signal of the first detection line Sense 1 to the output terminal of the first driving transistor DT 1 in response to the third strobe signal G 3 .

When the control signal G 0 is at a high level, the first control transistor T 1 is turned on, and the first data signal Data- 1 is also a high level signal and is transmitted to the control terminal of the first driving transistor DT 1 . At this time, the first driving transistor DT 1 is turned on, and outputs a driving current to the anode of the OLED unit under the action of the first voltage signal VDD to drive the OLED unit to emit light. At the same time, the first strobe signal G 1 is at a high level, and the first switching sub-circuit ST 1 is turned on, so that the current output by the first driving transistor DT 1 is transmitted to the first detection line Sense 1 , thus realizing signal feedback of the output current. Further, the first detection line Sense 1 can transmit the received signal to the driving chip, and the driving chip realizes compensation for the first sub-pixel by the first data signal Data- 1 . In the reset phase, the first strobe signal G 1 and the third strobe signal G 3 are both at a high level, and the first switching sub-circuit ST 1 and the first reset sub-circuit RT 1 are simultaneously turned on, so that the voltage signal of the first detection line Sense 1 , such as a low level signal, is transmitted to the output terminal of the first driving transistor DT 1 , thus rapidly pulling down the anode potential of the OLED lighting unit to complete the reset operation.

The example arrangement further provides a driving compensation method based on the pixel driving compensation circuit described above, for detecting and compensating a driving current of each sub-pixel in the pixel unit. As shown in FIG. 4 , the driving compensation method may include the following blocks.

Block S 1 , turning on a first switching sub-circuit ST 1 and a third switching sub-circuit ST 3 in a first period by a first strobe signal G 1 , and turning off a second switching sub-circuit ST 2 in the first period by a second strobe signal G 2 , so that a driving current output by a first driving transistor DT 1 is transmitted to a first detection line Sense 1 through the first switching sub-circuit ST 1 and fed back to a driving module, a driving current output by a third driving transistor DT 3 is transmitted to a second detection line Sense 2 through the third switching sub-circuit ST 3 and fed back to the driving module, and the driving module respectively reads the driving current output by the first driving transistor DT 1 and the driving current output by the third driving transistor DT 3 , and calculates a compensation voltage of a first sub-pixel 10 and a compensation voltage of a third sub-pixel 30 respectively;

Block S 2 , turning off the first switching sub-circuit ST 1 and the third switching sub-circuit ST 3 in a second period by the first strobe signal G 1 , and turning on the second switching sub-circuit ST 2 in the second period by the second strobe signal G 2 , so that a driving current output by a second driving transistor DT 2 is transmitted to the first detection line Sense 1 through the second switching sub-circuit ST 2 and fed back to the driving module, and the driving module reads the driving current output by the second driving transistor DT 2 and calculates a compensation voltage of a second sub-pixel 20 .

It should be noted that if the first to third driving transistors DT 1 -DT 3 output the driving currents, it needs that the first to third driving transistors DT 1 -DT 3 are turned on and the first voltage signal VDD is input. Therefore, when performing the above blocks S 1 and S 2 , the control transistors T 1 -T 3 of the respective sub-pixels need to be turned on under the action of the control signal G 0 , so that the first to third data signals Data- 1 ˜Data- 3 are respectively transmitted to the control terminals of the first to the third driving transistors DT 1 -DT 3 to turn on the first to the third driving transistors DT 1 -DT 3 .

The pixel driving compensation method provided by the exemplary arrangement of the present disclosure, on the one hand, completes current detection of the first sub-pixel 10 and the third sub-pixel 30 connected to different detection lines in the same period, which saves detection time and provides a basis for subsequent real-time compensation, thus shortening the occupation time of external compensation; on the other hand, completes current detection of the first sub-pixel 10 and the second sub-pixel 20 sharing the same detection line in different periods, thus avoiding signal interference between different sub-pixels, preventing distortion of the compensation signal and thus improving the display effect.

Based on the above-described driving compensation method, it is mainly described that the OLED pixel unit has three sub-pixels. In the case that the OLED pixel unit further includes a fourth sub-pixel, the driving compensation method may further include: turning off a fourth switching sub-circuit ST 4 in the first period by the second strobe signal G 2 when turning on the first switching sub-circuit ST 1 and the third switching sub-circuit ST 3 in the first period by the first strobe signal G 1 , and turning off the second switching sub-circuit ST 2 in the first period by the second strobe signal G 2 ; and turning on the fourth switching sub-circuit ST 4 in the second period by the second strobe signal G 2 when turning off the first switching sub-circuit ST 1 and the third switching sub-circuit ST 3 in the second period by the first strobe signal G 1 , and turning on the second switching sub-circuit ST 2 in the second period by the second strobe signal G 2 , so that a driving current output by a fourth driving transistor DT 4 is transmitted to the second detection line Sense 2 through the fourth switching sub-circuit ST 4 and fed back to the driving module, and the driving module reads the driving current output by the fourth driving transistor DT 4 and calculates a compensation voltage of the fourth sub-pixel 40 .

Based on this, in the case where the OLED pixel unit has four sub-pixels, as shown in FIG. 5 , the driving compensation method may include the following blocks.

Block S 10 , turning on the first switching sub-circuit ST 1 and the third switching sub-circuit ST 3 in the first period by the first strobe signal G 1 , and turning off the second switching sub-circuit ST 2 and the fourth switching sub-circuit ST 4 in the first period by the second strobe signal G 2 , so that the driving current output by the first driving transistor DT 1 is transmitted to the first detection line Sense 1 through the first switching sub-circuit ST 1 and fed back to the driving module, the driving current output by the third driving transistor DT 3 is transmitted to the second detection line Sense 2 through the third switching sub-circuit ST 3 and fed back to the driving module, and the driving module respectively reads the driving current output by the first driving transistor DT 1 and the driving current output by the third driving transistor DT 3 , and calculates the compensation voltage of the first sub-pixel 10 and the compensation voltage of the third sub-pixel 30 respectively;

Block S 20 , turning off the first switching sub-circuit ST 1 and the third switching sub-circuit ST 3 in the second period by the first strobe signal G 1 , and turning on the second switching sub-circuit ST 2 and the fourth switching sub-circuit ST 4 in the second period by the second strobe signal G 2 , so that the driving current output by the second driving transistor DT 2 is transmitted to the first detection line Sense 1 through the second switching sub-circuit ST 2 and fed back to the driving module, the driving current output by the fourth driving transistor DT 4 is transmitted to the second detection line Sense 2 through the fourth switching sub-circuit ST 4 and fed back to the driving module, and the driving module reads the driving current output by the second driving transistor DT 2 and the driving current output by the fourth driving transistor DT 4 and calculates the compensation voltage of the second sub-pixel 20 and the compensation voltage of the fourth sub-pixel 40 respectively.

It should be noted that if the first to fourth driving transistors DT 1 -DT 4 output the driving current, it needs that the first to fourth driving transistors DT 1 -DT 4 are turned on and the first voltage signal VDD is input. Therefore, when performing the above blocks S 10 and S 20 , the control transistors T 1 -T 4 of the respective sub-pixels need to be turned on under the action of the control signal G 0 , so that the first to fourth data signals Data- 1 ˜Data- 4 are respectively transmitted to the control terminals of the first to the fourth driving transistors DT 1 -DT 4 to turn on the first to the fourth driving transistors DT 1 -DT 4 .

In the present exemplary arrangement, the control terminals of the control transistors of the respective sub-pixels receive the same control signal G 0 , and thus the control signal G 0 can simultaneously turn on or off the respective control transistors. The current detections of the first sub-pixel 10 and the third sub-pixel 30 are both in the first period. At this time, only the first driving transistor DT 1 and the third driving transistor DT 3 should be turned on and output current, but due to the action of the control signal G 0 , the second driving transistor DT 2 and the fourth driving transistor DT 4 are also turned on. In order to prevent the current output from the second driving transistor DT 2 and/or the fourth driving transistor DT 4 from disturbing the output current detection of the first sub-pixel 10 and/or the third sub-pixel 30 , the second data signal Data- 2 of the second sub-pixel 20 and the fourth data signal Data- 4 of the fourth sub-pixel 40 are in a non-working period. Similarly, the current detections of the second sub-pixel 20 and the fourth sub-pixel 40 are both in the second period, and at this time, the first data signal Data- 1 of the first sub-pixel 10 and the third data signal Data- 3 of the third sub-pixel 30 may be in a non-working period.

In the present exemplary arrangement, for a P-type thin film transistor, a working period refers to a low-level period, and a non-working period refers to a high-level period; for an N-type thin film transistor, a working period refers to a high-level period and a non-working period refers to a low-level period.

Based on this, as shown in FIG. 6 , in the compensation phase, the working periods of the first data signal Data- 1 and the third data signal Data- 3 may be the same as the working period of the first strobe signal G 1 , and the working periods of the second data signal Data- 2 and the fourth data signal Data- 4 can be the same as the working period of the second strobe signal G 2 , which can solve the problem of signal interference.

When the N-type thin film transistor is used in the present arrangement, the above description can be understood as: a high level period of the first data signal Data- 1 of the first sub-pixel 10 and the third data signal Data- 3 of the third sub-pixel 30 is the same as a high level period of the first strobe signal G 1 , and a high level period of a second data signal Data- 2 of the second sub-pixel 20 and a fourth data signal Data- 4 of the fourth sub-pixel 40 is the same as a high level period of the second strobe signal G 2 .

When the P-type thin film transistor is used in the present arrangement, the above description can be understood as: a low level period of the first data signal Data- 1 of the first sub-pixel 10 and the third data signal Data- 3 of the third sub-pixel 30 is the same as a low level period of the first strobe signal G 1 , and a low level period of a second data signal Data- 2 of the second sub-pixel 20 and a fourth data signal Data- 4 of the fourth sub-pixel 40 is the same as a low level period of the second strobe signal G 2 .

The driving compensation method provided by the example arrangement may implement detection and compensation of the output current of the driving transistor by the above method in the compensation phase, and in the reset phase may include

turning on the first to third switching sub-circuits ST 1 -ST 3 through the first strobe signal G 1 and the second strobe signal G 2 , transmitting the voltage signal of the first detection line to the output terminals of the first driving transistor DT 1 and the second driving transistor DT 2 respectively and transmitting the voltage signal of the second detection line Sense 2 to the output terminal of the third driving transistor DT 3 .

When the OLED pixel unit further includes a fourth sub-pixel, the driving compensation method further includes turning on the fourth switching sub-circuit ST 4 by the second strobe signal G 2 , and transmitting the voltage signal of the second detection line Sense 2 to the output terminal of the fourth driving transistor DT 4 .

In this way, the reset function can be realized by the switching sub-circuits ST 1 -ST 4 of the respective sub-pixels in the reset phase. However, in the field of high-frequency display, if only a single switching sub-circuit is used for resetting, the resetting ability is weak, which may cause a problem of poor display effect. Therefore, a resetting sub-circuit and the above switching sub-circuit may constitute a double-switching structure to enhance the resetting ability.

On the basis of the above, the driving compensation method in the reset phase may further include: turning on the first to third reset sub-circuits RT 1 ˜RT 3 respectively by a third strobe signal G 3 , transmitting the voltage signal of the first detection line Sense 1 to the output terminals of the first driving transistor DT 1 and the second driving transistor DT 2 respectively and transmitting the voltage signal of the second detection line to the output terminal of the third driving transistor DT 3 .

Of course, when the OLED pixel unit further includes the fourth sub-pixel, the driving compensation method further includes: turning on the fourth reset sub-circuit RT 4 by a third strobe signal G 3 , and transmitting a voltage signal of the second detection line Sense 2 to an output terminal of the fourth driving transistor DT 4 .

The first switching sub-circuit ST 1 and the first reset sub-circuit RT 1 are simultaneously turned on, the second switching sub-circuit ST 2 and the second reset sub-circuit RT 2 are simultaneously turned on, the third switching sub-circuit ST 3 and the third reset sub-circuit RT 3 are simultaneously turned on, and the fourth switching sub-circuit ST 4 and the fourth reset sub-circuit RT 4 are simultaneously turned on.

Hereinafter, taking all of the switching sub-circuits/transistors as N-type thin film transistors as an example, the pixel driving compensation method in the present exemplary arrangement will be described in detail with reference to FIGS. 2 and 6 .

In the compensation phase, the first sub-pixel 10 and the third sub-pixel 30 perform detection and compensation of the output current of the driving transistor in the first period, and the second sub-pixel 20 and the fourth sub-pixel 40 perform detection and compensation of the output current of the driving transistor in the second period.

In the first period, the control signal G 0 and the first strobe signal G 1 are at a high level, the first data signal Data- 1 and the third data signal Data- 3 are at a high level, and the first control transistor T 1 is turned on to transmit the first data signal Data- 1 to the control terminal of the first driving transistor DT 1 , and then the first driving transistor DT 1 is turned on to transmit the first voltage signal VDD to the anode of the first OLED light emitting unit, and the first switching sub-circuit ST 1 is turned on to transmit the output current of the first driving transistor DT 1 to the first detection line Sense 1 . Similarly, the third control transistor T 3 is turned on to transmit the third data signal Data- 3 to the control terminal of the third driving transistor DT 3 , and then the third driving transistor DT 3 is turned on to transmit the first voltage signal VDD to the anode of the third OLED lighting unit, and the third switching sub-circuit ST 3 is turned on to transmit the output current of the third driving transistor DT 3 to the second detection line Sense 2 . The first detection line Sense 1 and the second detection line Sense 2 respectively transmit the received current signals to the driving chip, and the current signals are respectively compensated after calculation processing.

In the second period, the control signal G 0 and the second strobe signal G 2 are at a high level, the second data signal Data- 2 and the fourth data signal Data- 4 are at a high level, the second control transistor T 2 is turned on to transmit the second data signal Data- 2 to the control terminal of the second driving transistor DT 2 , and then the second driving transistor DT 2 is turned on to transmit the first voltage signal VDD to the anode of the second OLED lighting unit, and the second switching sub-circuit ST 2 is turned on to transmit the output current of the second driving transistor DT 2 to the first detection line Sense 1 . Similarly, the fourth control transistor T 4 is turned on to transmit the fourth data signal Data- 4 to the control terminal of the fourth driving transistor DT 4 , and then the fourth driving transistor DT 4 is turned on to transmit the first voltage signal VDD to the anode of the fourth OLED lighting unit, and the fourth switching sub-circuit ST 4 is turned on to transmit the output current of the fourth driving transistor DT 4 to the second detection line Sense 2 . The first detection line Sense 1 and the second detection line Sense 2 respectively transmit the received current signals to the driving chip, and the current signals are respectively compensated after calculation processing.

Through the above detection and compensation method, the respective sub-pixels can be separated from each other, thus avoiding the defect in a certain sub-pixel from affecting the data of other sub-pixels during the current detection and resulting in abnormal display after compensation, and also shortening the detection time and providing technical support for real-time compensation, which shortens the occupation time of external compensation.

In the reset phase, the first detection line Sense 1 and the second detection line Sense 2 provide a reset signal such as a low level signal, a control signal G 0 , a first strobe signal G 1 , a second strobe signal G 2 , and a third strobe signal G 3 are all at a high level, and the first to fourth control transistors T 1 to T 4 , the first to fourth switching sub-circuits ST 1 to ST 4 , and the first to fourth reset sub-circuits RT 1 to RT 4 are all turned on, the first switching sub-circuit ST 1 and the first reset sub-circuit RT 1 constitute a first switch pair, the second switch sub-circuit ST 2 and the second reset sub-circuit RT 2 constitute a second switch pair, the third switch sub-circuit ST 3 and the third reset sub-circuit RT 3 constitute a third switch pair, and the fourth switch sub-circuit ST 4 and the fourth reset sub-circuit RT 4 constitute a fourth switch pair. Based on the switch pair structure, the anode potential of each OLED light emitting unit can be quickly pulled down, thus completing the writing data and the reset operation.

It should be noted that the specific details of the pixel driving compensation method have been described in detail in the corresponding pixel driving compensation circuit, and details are not described herein again.

It should be noted that although modules or units of devices for executing functions are described above, such division of modules or units is not mandatory. In fact, features and functions of two or more of the modules or units described above may be embodied in one module or unit in accordance with the arrangements of the present disclosure. Alternatively, the features and functions of one module or unit described above may be further divided into multiple modules or units.

In addition, although the various blocks of the method of the present disclosure are described in a particular order in the figures, this is not required or implied that the blocks must be performed in the specific order, or all the blocks shown must be performed to achieve the desired result. Additionally or alternatively, certain blocks may be omitted, multiple blocks may be combined into one block, and/or one block may be decomposed into multiple blocks and so on.

Through the description of the above arrangements, those skilled in the art will readily understand that the exemplary arrangements described herein may be implemented by software or by a combination of software with necessary hardware. Therefore, the technical solutions according to arrangements of the present disclosure may be embodied in the form of a software product, which may be stored in a non-volatile storage medium (which may be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network. A number of instructions are included to cause a computing device (which may be a personal computer, server, mobile terminal, or network device, etc.) to perform the methods in accordance with the arrangements of the present disclosure.

Other arrangements of the present disclosure will be apparent to those skilled in the art after considering the specification and practicing the present disclosure. The present application is intended to cover any variations, uses, or adaptations of the present disclosure, which are in accordance with the general principles of the present disclosure and include common general knowledge or conventional technical means in the art that are not disclosed in the present disclosure. The specification and arrangements are illustrative, and the real scope and spirit of the present disclosure is defined by the appended claims.