CN109545134B

CN109545134B - OLED display panel driving circuit and driving method

Info

Publication number: CN109545134B
Application number: CN201811456743.4A
Authority: CN
Inventors: 解红军
Original assignee: Kunshan Govisionox Optoelectronics Co Ltd
Current assignee: Kunshan Govisionox Optoelectronics Co Ltd
Priority date: 2018-11-30
Filing date: 2018-11-30
Publication date: 2020-07-03
Anticipated expiration: 2038-11-30
Also published as: CN109545134A

Abstract

The invention discloses an OLED display panel driving circuit and a driving method. The drive circuit includes: a driving chip; the driving chip includes: the gating module is respectively connected with the plurality of induction lines and is used for controlling the communication between the induction lines and the detection compensation module simultaneously or sequentially; and the detection compensation module is used for acquiring the charge quantity flowing through the OLED device in each sub-pixel unit through the corresponding induction line in a preset detection time in a detection mode, detecting a voltage difference value corresponding to the charge quantity, and acquiring a compensation gain value of the OLED device in each sub-pixel unit according to the voltage difference value. Through the mode, the compensation gain value of the OLED device can be obtained in a relatively accurate mode, and the aging of the OLED device is compensated by the compensation gain value so as to improve the compensation accuracy.

Description

OLED display panel driving circuit and driving method

Technical Field

The invention relates to the technical field of display, in particular to a drive circuit and a drive method of an OLED display panel.

Background

An Organic Light Emitting Diode (OLED) Display panel has many advantages of self-luminescence, low driving voltage, high luminous efficiency, short response time, high definition and contrast, wide temperature range, and capability of implementing flexible Display and large-area full-color Display lamps, and is considered as a Display panel with the most potential development by the industry.

For an OLED display panel, each sub-pixel unit includes an OLED device and a driving circuit for driving the OLED device to emit light. With the use of the OLED display panel, the OLED device may age, and the overall brightness of the OLED display panel may decrease. In addition, the aging degree of the OLED devices at different positions in the same OLED display panel is different, wherein the longer the OLED display panel is used, the higher the brightness of the sub-pixel unit is, the more the OLED device is aged, and further the problem of image sticking occurs in the display of the OLED display panel.

Disclosure of Invention

The invention mainly solves the technical problem of providing an OLED display panel driving circuit and a driving method, which can acquire a compensation gain value of an OLED device in a relatively accurate mode, and further compensate the aging of the OLED device by utilizing the compensation gain value so as to improve the display uniformity.

In order to solve the technical problems, the invention adopts a technical scheme that: the OLED display panel comprises a plurality of sub-pixel units which are arranged in an array mode, each column of sub-pixel units is connected with a corresponding induction line, and the driving circuit comprises: the driving chip comprises a gating module and a detection compensation module; the gating module is respectively connected with the plurality of induction lines and is used for controlling the communication between the induction lines and the detection compensation module simultaneously or sequentially; the detection compensation module is used for acquiring the charge quantity flowing through the OLED device in each sub-pixel unit through the corresponding induction line in the preset detection time in the detection mode, detecting a voltage difference value corresponding to the charge quantity, and acquiring the compensation gain value of the OLED device in each sub-pixel unit according to the voltage difference value so that the OLED display panel can compensate the aging of the OLED device in each sub-pixel unit according to the compensation gain value.

In order to solve the technical problems, the invention adopts another technical scheme that: provided is an OLED display panel driving method, including: acquiring the charge quantity flowing through the OLED device in each sub-pixel unit in a preset detection time and detecting a voltage difference value corresponding to the charge quantity in a detection mode; obtaining a compensation gain value corresponding to each sub-pixel unit according to the voltage difference value; and acquiring a compensation gray-scale value corresponding to each compensated sub-pixel unit by using the compensation gain value in a display mode and displaying the compensation gray-scale value.

The invention has the beneficial effects that: according to the OLED display panel driving circuit and driving method, the charge quantity flowing through the OLED device in each sub-pixel unit through the corresponding induction line in the preset detection time is obtained in the detection mode, the voltage difference corresponding to the charge quantity is detected, and the compensation gain value of the OLED device in each sub-pixel unit is obtained according to the voltage difference, so that the OLED display panel compensates the aging of the OLED device in each sub-pixel unit according to the compensation gain value. Through the mode, the compensation gain value of the OLED device can be obtained by utilizing the charge quantity flowing through the OLED device in each sub-pixel unit through the corresponding induction line in the preset detection time, so that the obtained compensation gain value is more accurate, and the aging of the OLED device can be compensated by utilizing the compensation gain value to improve the compensation accuracy.

Drawings

Fig. 1 is a schematic structural diagram of an OLED display panel according to a first embodiment of the present invention;

FIG. 2 is a schematic structural diagram of an OLED display panel according to a second embodiment of the present invention;

FIG. 3 is a schematic diagram of a portion of an electrical circuit of one embodiment of a sub-pixel unit in the OLED display panel of FIG. 2;

FIG. 4 is a circuit schematic of a first embodiment of a switching unit in the OLED display panel of FIG. 2;

FIG. 5 is a circuit schematic diagram of a second embodiment of a switching unit in the OLED display panel shown in FIG. 2;

FIG. 6 is a circuit schematic of an embodiment of a gating module in the OLED display panel of FIG. 2;

FIG. 7 is a schematic circuit diagram of a first embodiment of a detection compensation module in the OLED display panel shown in FIG. 2;

FIG. 8 is a schematic circuit diagram of a second embodiment of a detection compensation module in the OLED display panel shown in FIG. 2;

FIG. 9 is a first timing diagram illustrating the driving circuit of the OLED display panel shown in FIG. 2 in a detecting mode;

FIG. 9A is a partial schematic view of an OLED display panel during a preset voltage phase;

FIG. 9B is a partial schematic view of the OLED display panel in the detection phase;

FIG. 9C is a partial schematic view of the OLED display panel during the sampling and conversion phase;

FIG. 10 is a second timing diagram illustrating the driving circuit of the OLED display panel shown in FIG. 2 in a detecting mode;

fig. 11 is a flowchart illustrating a driving method of an OLED display panel according to an embodiment of the present invention.

Detailed Description

Where certain terms are used throughout the description and claims to refer to particular components, those skilled in the art will appreciate that manufacturers may refer to the same components by different names. In the present specification and claims, the difference in name is not used as a means for distinguishing between components, but a difference in function of a component is used as a reference for distinguishing between components. The present invention will be described in detail below with reference to the accompanying drawings and examples.

Fig. 1 is a schematic structural diagram of an OLED display panel according to a first embodiment of the present invention. As shown in fig. 1, the OLED display panel 100 "includes a plurality of sub-pixel units 10" and a plurality of sensing lines Sense "arranged in an array, wherein each column of sub-pixel units 10" is connected to a corresponding sensing line Sense ".

The OLED display panel 100 "further includes a driving circuit 20", wherein the driving circuit 20 "includes a driving chip 22".

The driving chip 22 "includes a gating module 221" and a detection compensation module 222 ". The gating module 221 ″ is respectively connected to the plurality of sensing lines Sense ″ and is configured to control the sensing lines Sense ″ to be simultaneously or sequentially communicated with the detection compensation module 222 ″. The detection compensation module 222 ″ is configured to, in the detection mode, obtain an amount of charge flowing through the OLED device in each sub-pixel unit 10 ″ through the corresponding Sense line Sense ″ within a predetermined detection time, detect a voltage difference corresponding to the amount of charge, and obtain a compensation gain value of the OLED device in each sub-pixel unit 10 ″ according to the voltage difference, so that the OLED display panel 100 ″ compensates for aging of the OLED device in each sub-pixel unit according to the compensation gain value.

Fig. 2 is a schematic structural diagram of an OLED display panel according to a second embodiment of the present invention. As shown in fig. 2, the OLED display panel 100 includes a plurality of sub-pixel units 10 arranged in an array, a plurality of Data lines Data, and a plurality of sensing lines Sense, wherein each column of sub-pixel units 10 is respectively connected to a corresponding Data line Data and a corresponding sensing line Sense.

The OLED display panel 100 further includes a driving circuit 20, wherein the driving circuit 20 includes a switching circuit 21 and a driving chip 22.

The switching circuit 21 includes a plurality of switching units 211, each switching unit 211 corresponds to one column of sub-pixel units 10, and each switching unit 211 is connected to the Data line Data and the sensing line Sense corresponding to the corresponding column of sub-pixel units 10.

The driving chip 22 includes a gating module 221 and a detection compensation module 222. The gating module 221 is respectively connected to the plurality of switching units 211, and is configured to control each switching unit 211 to be simultaneously or sequentially communicated with the detection compensation module 222. The detection compensation module 222 is configured to, in the detection mode, obtain an amount of charge flowing through the OLED device in each sub-pixel unit 10 through the corresponding Sense line Sense within a predetermined detection time and detect a voltage difference corresponding to the amount of charge, and obtain a compensation gain value of the OLED device in each sub-pixel unit 10 according to the voltage difference, so that the OLED display panel 100 compensates for aging of the OLED device in each sub-pixel unit according to the compensation gain value.

Referring to fig. 3, fig. 3 is a schematic circuit diagram of a portion of an embodiment of a sub-pixel unit in the OLED display panel shown in fig. 2. As shown in fig. 3, each sub-pixel unit 10 includes a sub-pixel module 11, an OLED device 12, a sixth switch M6, a second capacitor CA2, and a third capacitor CA 3.

The sub-pixel module 11 includes a first terminal a1 and a second terminal a2, and the sixth switch M6 includes a control terminal, a first path terminal and a second path terminal. The first end a1 of the sub-pixel module 11 is connected to a corresponding Data line Data, and the second end a2 of the sub-pixel module 11 is connected to the anode of the OLED device 12 and the second path end of the sixth switch M6; a control end of the sixth switch M6 receives a sixth control signal C6, and a first path end of the sixth switch M6 is connected to a corresponding one of the sensing lines Sense; the cathode of OLED device 12 is coupled to a second reference voltage ELVSS.

Each sensing line Sense is correspondingly connected with a second capacitor CA2, wherein a first end of the second capacitor CA2 is connected with the corresponding sensing line Sense, and a second end of the second capacitor CA2 is grounded VSS.

Each Data line Data is correspondingly connected with a third capacitor CA3, wherein a first end of the third capacitor CA3 is connected with the corresponding Data line Data, and a second end of the third capacitor CA3 is grounded VSS.

Referring to fig. 4, fig. 4 is a schematic circuit diagram of a first embodiment of a switching unit in the OLED display panel shown in fig. 2. As shown in fig. 4, each switching unit 211 corresponds to a column of sub-pixel units 10, and each switching unit 211 includes a first terminal S1, a second terminal S2, and a third terminal S3. The first terminal S1 and the second terminal S2 of each switching unit 211 are respectively connected to a Data line Data and a sensing line Sense corresponding to a column of sub-pixel units 10, and the third terminal S3 of each switching unit 211 is connected to the gate module 221.

Specifically, the switching unit 211 includes a first switch M1 and a second switch M2, wherein the first switch M1 and the second switch M2 include a control terminal, a first path terminal and a second path terminal.

The control end of the first switch M1 is used for receiving the first control signal C1, and the first end S1 of the first switch M1 as the first end of the switching unit 211 is connected to the Data line Data corresponding to a column of sub-pixel units 10. The control terminal of the second switch M2 is used for receiving the second control signal C2, and the first path terminal of the second switch M2 is used as the second terminal S2 of the switching unit 211 to connect to the sensing line Sense corresponding to a column of sub-pixel units 10.

The second path terminal of the first switch M1 and the second path terminal of the second switch M2 are connected together, and a node at the connection is connected to the gating module 221 as the third terminal S3 of the switching unit 211.

In the present embodiment, the first switch M1 and the second switch M2 are preferably PMOS transistors, that is, the control terminal, the first path terminal and the second path terminal of the first switch M1 and the second switch M2 correspond to the gate, the drain and the source of the PMOS transistor, respectively. In other words, in the present embodiment, the first switch M1 and the second switch M2 are active low.

Referring to fig. 5, fig. 5 is a schematic circuit diagram of a second embodiment of a switching unit in the OLED display panel shown in fig. 2. As shown in fig. 5, each switching unit 211 corresponds to a column of sub-pixel units 10, and each switching unit 211 includes a first terminal S1 ', a second terminal S2 ', and a third terminal S3 '. The first terminal S1 ' and the second terminal S2 ' of each switching unit 211 are respectively connected to a Data line Data and a sensing line Sense of a corresponding column of sub-pixel units 10, and the third terminal S3 ' of each switching unit 211 is connected to the gating module 221.

Specifically, the switching unit 211 includes a first switch M1 ', a second switch M2', and a third switch M3 ', wherein the first switch M1', the second switch M2 ', and the third switch M3' include a control terminal, a first path terminal, and a second path terminal.

The control terminal of the first switch M1 ' is used for receiving the first control signal C1 ', the first path terminal of the first switch M1 ' is used as the first terminal S1 ' of the switching unit 211 to connect to the Data line Data corresponding to a column of sub-pixel units 10, and the second path terminal of the first switch M1 ' is used as the third terminal S3 of the switching unit 211 to connect to the gating module 221. The control terminal of the second switch M2 ' is used for receiving the second control signal C2 ', the first path terminal of the second switch M2 ' is used as the second terminal S2 ' of the switching unit 211 to connect to the sensing line Sense corresponding to a column of sub-pixel units 10, and the second path terminal of the second switch M2 ' is connected to the initial voltage Vini. The control terminal of the third switch M3 'is configured to receive the third control signal C3', the first terminal of the third switch M3 'is connected to the second terminal of the first switch M1', and the second terminal of the third switch M3 'is connected to the first terminal of the second switch M2'.

In the present embodiment, the initial voltage Vini is used to initialize the corresponding sub-pixel cell 10 through the second switch M2' during the display phase.

In this embodiment, the first switch M1 ', the second switch M2' and the third switch M3 'are preferably PMOS transistors, that is, the control terminal, the first pass terminal and the second pass terminal of the first switch M1', the second switch M2 'and the third switch M3' respectively correspond to the gate, the drain and the source of the PMOS transistor. In other words, in the present embodiment, the first switch M1 ', the second switch M2 ' and the third switch M3 ' are active low.

Referring to fig. 6, fig. 6 is a schematic circuit diagram of an embodiment of a gate module in the OLED display panel shown in fig. 2. As shown in fig. 6, the gating module 221 includes a plurality of fourth switches M4, wherein the fourth switches M4 include a control terminal, a first path terminal, and a second path terminal.

The control terminal of each fourth switch M4 receives a corresponding fourth control signal C4, the first path terminal of each fourth switch M4 is connected to the third terminal S3 or S3' of the corresponding switching unit 211, and the second path terminal of each fourth switch M4 is connected to the detection and compensation module 222.

In this embodiment, the fourth switch M4 is preferably an NMOS transistor, that is, the control terminal, the first path terminal, and the second path terminal of the fourth switch M4 correspond to the gate, the drain, and the source of the NMOS transistor, respectively. In other words, in the present embodiment, the fourth switch M4 is active low.

When the fourth control signals C4 are asserted simultaneously, the switching units 211 corresponding to the fourth switches M4 are turned on simultaneously with the detection and compensation module 222, so as to initialize all the sensing lines Sense in the OLED display panel 100 simultaneously. When the fourth control signals C4 are sequentially asserted, the switching units 211 corresponding to the fourth switches M4 are sequentially turned on by the detection and compensation module 222, so as to sequentially perform voltage detection on the sub-pixel units 10 in the same column by the detection and compensation module 222.

Referring to fig. 7, fig. 7 is a schematic circuit diagram of a detection compensation module of the OLED display panel shown in fig. 2 according to a first embodiment. As shown in fig. 7, the detection compensation module 222 includes an integration unit 2221, a fifth switch M5, a first capacitor CA1, a sampling switch SM, and an analog-to-digital conversion unit 2222.

The integrating unit 2221 includes a first input terminal, a second input terminal and an output terminal, the first input terminal of the integrating unit 2221 is connected to the second path terminal of each fourth switch M4 in the gating module 221, and the second input terminal of the integrating unit 2221 is configured to receive the first reference voltage V_REFThe output of the integrating unit 2221 is connected to the analog-to-digital conversion unit 2222 via the sampling switch SM. A first capacitor CA1 is connected between the first input and the output of the integrating cell 2221.

A fifth switch M5, which includes a control terminal, a first path terminal and a second path terminal, the control terminal of the fifth switch M5 receives the fifth control signal C5, the first path terminal is connected to the first input terminal of the integrating unit 2221, and the second path terminal is connected to the output terminal of the integrating unit 2221.

The sampling switch SM includes a control end, a first path end and a second path end, the control end of the sampling switch SM receives the sampling signal SMP, the first path end is connected to the output end of the integrating unit 2221, and the second path end is connected to the analog-to-digital conversion unit 2222.

In the present embodiment, the integrating unit 2221 is preferably an operational amplifier, that is, the first input terminal, the second input terminal and the output terminal of the integrating unit 2221 correspond to the inverting input terminal, the non-inverting input terminal and the output terminal of the operational amplifier, respectively.

Referring to fig. 8, fig. 8 is a schematic circuit diagram of a second embodiment of a detection compensation module in the OLED display panel shown in fig. 2. As shown in fig. 8, the detection compensation module 222 includes a plurality of detection compensation units 223, a gating unit 224 and an analog-to-digital conversion unit 2222'.

Each of the detection compensation units 223 is respectively connected to the gate module 221 to be connected to a corresponding one of the switching units 211 through the gate module 221, and each of the detection compensation units 223 respectively includes an integration unit 2221 ', a fifth switch M5 ', and a first capacitor CA1 '.

The integrating unit 2221 ' includes a first input terminal, a second input terminal and an output terminal, the first input terminal of the integrating unit 2221 ' is connected to the gating module 221, and the second input terminal of the integrating unit 2221 ' is used for receiving the first reference voltage V_REF. A first capacitor CA1 'is connected between the first input and the output of the integrating cell 2221'. A fifth switch M5 ' comprising a control terminal, a first path terminal and a second path terminal, the control terminal of the fifth switch M5 ' receiving a fifth control signal C5 ', the first path terminal being connected to the first input terminal of the integrating unit 2221 ' and the second path terminal being connected to the output terminal of the integrating unit 2221 '.

In the present embodiment, the integrating unit 2221 'is preferably an operational amplifier, that is, the first input terminal, the second input terminal and the output terminal of the integrating unit 2221' correspond to the inverting input terminal, the non-inverting input terminal and the output terminal of the operational amplifier, respectively.

The gating unit 224 is respectively connected to the output ends of the multiple integrating units 2221 'and the analog-to-digital conversion unit 2222', and is configured to control the integrating units 2221 'to be sequentially connected to the analog-to-digital conversion unit 2222'.

Specifically, the gating unit 224 includes a plurality of sampling switches SM ', wherein the sampling switches SM' include a control terminal, a first path terminal, and a second path terminal.

The control terminal of each sampling switch SM ' receives a corresponding sampling signal SMP ', the first path terminal of each sampling switch SM ' is connected to the corresponding detection compensation unit 223, and the second path terminal of each sampling switch SM ' is connected to the analog-to-digital conversion unit 2222 ' after being connected to each other.

In this embodiment, the sampling switch SM 'is preferably an NMOS transistor, that is, the control terminal, the first path terminal, and the second path terminal of the sampling switch SM' correspond to the gate, the drain, and the source of the NMOS transistor, respectively. In other words, in the present embodiment, the sampling switch SM' is active low.

Referring to fig. 9, fig. 9 is a first operation timing diagram of the driving circuit in the OLED display panel shown in fig. 2 in the detection mode. As shown in fig. 9, the OLED display panel 100 includes the sub-pixel units shown in fig. 3, the switching unit shown in fig. 4, the gating module shown in fig. 6, and the detection compensation module shown in fig. 7, and in order to obtain the amount of charge that the OLED display panel 100 flows through the OLED device 12 in each sub-pixel unit 10 through the corresponding sensing line Sense and detect the voltage difference corresponding to the amount of charge, the working cycle of the driving circuit 2 in the detection mode includes a preset voltage phase t1, a detection phase t2, and a sampling and converting phase t 3.

During the preset voltage period t1, as shown in fig. 9A, the fifth control signal C5 is asserted, the fifth switch M5 is turned on, the integrating unit 2221 is a buffer, and the first reference voltage V is applied_REFTo the gating module 221; the plurality of fourth control signals C4 are simultaneously active, the first reference voltage V_REFIs transmitted to a plurality of switching units 211 simultaneously; the first control signal C1 and the sixth control signal C6 are inactive, the second control signal C2 is active, and the first reference voltage V is_REFIs simultaneously transmitted to each of the sensing lines Sense and the second capacitor CA2 connected to each of the sensing lines Sense.

It should be emphasized that it is necessary to ensure that the time of the preset voltage period t1 is long enough, that is, the second capacitor CA2 connected to each Sense line Sense is charged to saturation, and the charging current becomes infinitesimal, at which time the voltage drop of the source/drain (D-S) of the second switch M2 reaches the minimum. In addition, the first reference voltage V is set at the preset voltage period t1_REFAnd the second reference voltage ELVSS is kept constant, and the first reference voltage V is kept constant_REFAnd the second reference voltage ELVSS is greater than the turn-on voltage of the OLED device 12.

During the detecting period t2, as shown in fig. 9B, the fifth control signal C5 is inactive, the fifth switch M5 is turned off, the integrating unit 2221 delivers charges to the gating module 221, and the voltage at the output terminal of the integrating unit 2221 begins to drop. The fourth control signal C4 in the plurality of fourth control signals C4 is asserted sequentially, the sub-pixel units 10 in the same row are detected one by one, and the charges of the first capacitor CA1 are transferred to the corresponding switching unit 211 through the fourth switch M4 controlled by the asserted fourth control signal C4; the first control signal C1 is inactive, the second control signal C2 and the sixth control signal C6 are active, and the charges of the first capacitor CA1 flow into the OLED device 12 through the second switch M2 and the sixth switch M6, forming a current path. The charge amount of the first capacitor CA1 is the charge amount flowing through the OLED device 12 during the detection period t 2.

It is emphasized that, due to the first reference voltage V_REFAnd control of the integration unit 2221, the voltage of the Sense line Sense is maintained at the first reference voltage V_REFIs constant, the level of the second reference voltage ELVSS is gradually increased during the detection period t2, so that the voltage across the OLED device 12 is gradually decreased. In the detection phase t2, the potential of the second reference voltage ELVSS is gradually increased, so that the voltage across the OLED device 12 is changed, and the erroneous recognition of the degradation degree of the OLED device 12 can be avoided. In other words, if the voltage across the OLED device 12 is not changed, the operating point of the OLED device 12 is fixed, and the detection may be inaccurate; if the voltage across the OLED device 12 changes, the operating point of the OLED device changes, and the detection is relatively accurate. In addition, the potential of the second reference voltage ELVSS needs to be ensured to be the first reference voltage V during the process of rising_REFAnd the second reference voltage ELVSS is greater than the turn-on voltage of OLED device 12, i.e., the OLED device 12 is kept in the on state during the detecting period t2 to form a current path.

During the sampling and converting period t3, as shown in fig. 9C, the second control signal C2 and the sixth control signal C6 change from active to inactive, the current path is cut off, the OLED device 12 no longer emits light, and the voltage at the output terminal of the integrating unit 2221 will remain unchanged. The sampling signal SMP is changed from inactive to active, the sampling switch SM is turned on, and the voltage at the output terminal of the integrating unit 2221 is transmitted to the analog-to-digital converting unit 2222.

It can be understood that, since there is only one integrating unit 2221 and one analog-to-digital converting unit 2222, the sub-pixel units 10 in the same row need to be detected one by one, that is, each time a row of sub-pixel units 10 in the same row is detected, the preset voltage phase t1, the detecting phase t2 and the sampling and converting phase t3 need to be repeatedly performed once.

Referring to fig. 10, fig. 10 is a second operation timing diagram of the driving circuit in the OLED display panel shown in fig. 2 in the detection mode. As shown in fig. 10, the OLED display panel 100 includes the sub-pixel units shown in fig. 3, the switching unit shown in fig. 5, the gating module shown in fig. 6, and the detection compensation module shown in fig. 8, and in order to obtain the amount of charge that the OLED display panel 100 flows through the OLED device 12 in each sub-pixel unit 10 through the corresponding sensing line Sense and detect the voltage difference corresponding to the amount of charge, the working cycle of the driving circuit 2 in the detection mode includes a preset voltage phase t1 ', a detection phase t2 ', and a sampling and converting phase t3 '.

In the preset voltage period t1 ', the fifth control signal C5' in each detection compensation unit 223 is asserted, the fifth switch M5 'is turned on, and the integration unit 2221' is a buffer for converting the first reference voltage V_REFTo the gating module 221; the plurality of fourth control signals C4 in the gating module 221 are simultaneously asserted, and the first reference voltage V is_REFIs transmitted to a plurality of switching units 211 simultaneously; the first control signal C1 ', the second control signal C2 ', the sixth control signal C6 are inactive, the third control signal C3 ' is active, and the first reference voltage V is_REFIs simultaneously transmitted to each of the sensing lines Sense and the second capacitor CA2 connected to each of the sensing lines Sense.

During the detecting period t2, the fifth control signal C5 'in each detection compensation unit 223 is disabled, the fifth switch M5' is turned off, the integration unit 2221 'delivers charges to the gating module 221, and the voltage at the output terminal of the integration unit 2221' begins to drop. The plurality of fourth control signals C4 in the gating module 221 are asserted simultaneously, the sub-pixel units 10 in the same column are detected simultaneously, and the charges of the first capacitor CA 1' in each detection compensation unit 223 are transferred to the corresponding switching unit 211 through the fourth switch M4; the first control signal C1 ', the second control signal C2 ' are inactive, the third control signal C2 ', the sixth control signal C6 are active, and the charges of the first capacitor CA1 ' in each detection compensation unit 223 flow into the OLED device 12 through the third switch M3 ' and the sixth switch M6, forming a current path.

It is emphasized that, due to the first reference voltage V_REFAnd control of the integration unit 2221', the voltage of the Sense line Sense is maintained at the first reference voltage V_REFThe level of the second reference voltage ELVSS is gradually increased without changing the level, so that the voltage across the OLED device 12 is gradually decreased, wherein the charge amount of each first capacitor CA 1' is the charge amount flowing through the corresponding OLED device 12 in the detection period t 2.

During the sampling and converting period t3, the third control signal C3' and the sixth control signal C6 change from active to inactive, the current path is cut off, the OLED device 12 no longer emits light, and the voltage at the output terminal of the integrating unit 2221 will remain unchanged. The sampling signal SMP 'is sequentially asserted, the sampling switch SM' is sequentially turned off, and the voltage at the output terminal of the integrating unit 2221 'in each detection and compensation unit 223 is sequentially transmitted to the analog-to-digital conversion unit 2222'.

It is understood that, due to the existence of the plurality of integration units 2221', the sub-pixel cells 10 in the same row can be detected at the same time, i.e., the preset voltage phase t1 and the detection phase t2 only need to be performed once. Since there is only one analog-to-digital conversion unit 2222 ', the voltage at the output of the integration unit 2221' needs to be converted from analog voltage to digital voltage one by one, i.e., the sampling and conversion stage t3 needs to be repeated.

Fig. 11 is a schematic flowchart of a driving method of an OLED display panel according to an embodiment of the present invention, and the driving method shown in fig. 11 is based on the driving circuit shown in fig. 1. As shown in fig. 11, the method includes the steps of:

step S101: in the detection mode, the charge quantity flowing through the OLED device in each sub-pixel unit in a preset detection time is obtained, and a voltage difference value corresponding to the charge quantity is detected.

In step S101, the charge amount Q flowing through the OLED device in each sub-pixel unit at the predetermined detection time in the detection mode satisfies the following formula:

Q＝∫₀ ^t2I_OLEDdt＝₁·(V_OUT-V_REF)

wherein, C₁Is the capacitance value of the first capacitor CA 1; v_OUTIs the voltage value collected at the output terminal of the integrating unit 2221 after the predetermined detection time t 2; v_REFIs the voltage value of the first reference voltage Vref; i is_OLEDIs the current value flowing through the OLED device 12 at the predetermined detection time t 2.

The degradation degree of the OLED device is obtained according to the voltage difference value delta V. The voltage difference Δ V is the voltage value V at the output terminal of the integration unit after the predetermined detection time t2_OUTVoltage value V of first reference voltage_REFThe difference between them, i.e. Δ V ═ V_OUT-V_REF. Wherein, the larger the charge quantity Q flowing through the OLED device, the larger the voltage difference value Δ V, and the more slight the degradation; the smaller the amount of charge Q flowing through the OLED device, the smaller the voltage difference Δ V, and the more severe the degradation.

It should be emphasized that, when the aging of the OLED device is detected according to the present invention, the detection is performed by detecting the current value I flowing into the OLED device at the predetermined detection time_OLEDAnd integrating the current value to obtain the amount of charge flowing through the OLED device at a predetermined detection time. That is, the present invention adopts the current-mode detection method, and compared with the voltage-mode detection method, the current-mode detection method has no influence of line voltage drop and D-S voltage drop of the switch, thereby improving the detection accuracy.

Step S102: and acquiring a compensation gain value corresponding to each sub-pixel unit according to the voltage difference value.

In step S102, the compensation gain value corresponding to each sub-pixel unit satisfies the following formula:

wherein, Δ V and Δ V₀The voltage difference values are respectively corresponding to the charge quantity of the OLED device passing through each sub-pixel unit in the preset detection time at the current moment and in the factory; v_OUTThe voltage value is acquired at the output end of the integration unit after the preset detection time at the current moment; v_{OUT_0}The initial voltage value is acquired at the output end of the integration unit after the preset detection time when leaving a factory; v_REFA reference voltage value provided for the integration unit; gain is the compensation Gain value corresponding to each sub-pixel unit.

Step S103: and acquiring a compensated gray-scale value corresponding to each sub-pixel unit after compensation by using the compensation gain value in a display mode and displaying the compensated gray-scale value.

In step S103, the step of obtaining and displaying the compensated gray-scale value corresponding to each sub-pixel unit by using the compensation gain value in the display mode includes: acquiring an input gray-scale value corresponding to each sub-pixel unit in a display mode; acquiring a compensated number compensation gray scale value according to the compensation gain value and the input gray scale value corresponding to each sub-pixel unit; and applying the corresponding compensation gray-scale value to each sub-pixel unit and displaying.

Specifically, a data voltage before compensation is obtained according to an input gray scale value of each sub-pixel unit, a current before compensation is obtained according to the data voltage before compensation, a current after compensation is obtained according to the current before compensation, a data voltage after compensation is obtained according to the current after compensation, and a compensation gray scale value is obtained according to the data voltage after compensation.

If the compensated current of the OLED device in each sub-pixel unit is I', and the current before compensation is I, the following formula is satisfied:

I′＝Gain·I

and Gain is a compensation Gain value corresponding to each sub-pixel unit.

In summary, in the present embodiment, the current-type electrical detection is adopted, and the line impedance and the D-S voltage drop of the switch have no influence on the detection, so that the detection accuracy is improved. In the embodiment, the voltage difference value is in a direct proportion relation with the discharge capacity of the OLED device, and the discharge capacity of the OLED device is in an inverse proportion relation with the aging, so that the aging degree of the OLED device can be sensed by an electrical method, and a compensation Gain value, namely a Gain value, is obtained through calculation. In the embodiment, the sub-pixel unit is compensated by using the Gain value, and the compensated current is Gain times of the current before compensation, i.e. the degradation of the OLED device is compensated by using a larger current, so that the aging of the OLED device is compensated by using the Gain value, and the compensation precision value is changed.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes performed by the present specification and drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. The OLED display panel driving circuit is characterized by comprising a plurality of sub-pixel units arranged in an array mode, wherein each column of the sub-pixel units is connected with a corresponding induction line, and the driving circuit comprises:

the driving chip comprises a gating module and a detection compensation module;

the gating module is respectively connected with the plurality of induction lines and is used for controlling the induction lines to be communicated with the detection compensation module simultaneously or sequentially;

the gating module is connected with the plurality of induction lines through the switching circuit respectively;

the detection compensation module is used for acquiring the charge quantity flowing through the OLED device in each sub-pixel unit through the corresponding induction line in a preset detection time in a detection mode, detecting a voltage difference value corresponding to the charge quantity, and acquiring a compensation gain value of the OLED device in each sub-pixel unit according to the voltage difference value so that the OLED display panel can compensate the aging of the OLED device in each sub-pixel unit according to the compensation gain value.

2. The driving circuit according to claim 1, wherein each column of the sub-pixel units is further connected to a corresponding data line, the switching circuit comprises a plurality of switching units, each switching unit corresponds to a column of the sub-pixel units, and each switching unit is connected to the data line and the sensing line corresponding to a column of the sub-pixel units.

3. The drive circuit according to claim 2, wherein each of the switching units comprises:

the first switch comprises a control end, a first access end and a second access end, the control end of the first switch is used for receiving a first control signal, and the first access end of the first switch is used as the first end of the switching unit to be connected with the data lines corresponding to the sub-pixel units in a column;

the second switch comprises a control end, a first path end and a second path end, the control end of the second switch is used for receiving a second control signal, and the first path end of the second switch is used as the second end of the switching unit to be connected with the sensing lines corresponding to the sub-pixel units in a row;

the second path end of the first switch and the second path end of the second switch are connected together, and a node at the connection position is used as a third end of the switching unit to be connected with the gating module.

4. The drive circuit according to claim 2, wherein each of the switching units comprises:

the first switch comprises a control end, a first path end and a second path end, the control end of the first switch is used for receiving a first control signal, the first path end of the first switch is used as the first end of the switching unit to be connected with the data lines corresponding to the sub-pixel units in a row, and the second path end of the first switch is used as the third end of the switching unit to be connected with the gating module;

the second switch comprises a control end, a first path end and a second path end, the control end of the second switch is used for receiving a second control signal, the first path end of the second switch is used as the second end of the switching unit to be connected with the induction lines corresponding to the sub-pixel units in a row, and the second path end of the second switch is connected with an initial voltage;

the control end of the third switch is used for receiving a third control signal, the first path end of the third switch is connected with the second path end of the first switch, and the second path end of the third switch is connected with the first path end of the second switch.

5. The driving circuit according to claim 3 or 4, wherein the detection compensation module comprises an integration unit, a fifth switch, a first capacitor, a sampling switch and an analog-to-digital conversion unit;

the integrating unit comprises a first input end, a second input end and an output end, the first input end of the integrating unit is connected to the gating module, the second input end of the integrating unit is used for receiving a first reference voltage, and the output end of the integrating unit is connected with the analog-to-digital conversion unit through the sampling switch;

the first capacitor is connected between the first input end and the output end of the integrating unit;

the fifth switch comprises a control end, a first path end and a second path end, the control end of the fifth switch receives a fifth control signal, the first path end is connected with the first input end of the integrating unit, and the second path end is connected with the output end of the integrating unit;

the sampling switch comprises a control end, a first path end and a second path end, the control end of the sampling switch receives a sampling signal, the first path end is connected with the output end of the integrating unit, and the second path end is connected with the analog-to-digital conversion unit.

6. The driving circuit according to claim 5, wherein a duty cycle of the driving circuit in the detection mode includes a preset voltage phase, a detection phase and a sampling and converting phase;

in the preset voltage stage, the first reference voltage is simultaneously transmitted to each induction line through the gating module and the switching unit;

in the detection stage, the integration unit transmits charges to the gating module, and the charges of the first capacitor flow into the OLED device through the corresponding induction line to form a current path;

in the sampling and converting phase, the current path is cut off, and the voltage at the output end of the integrator is transmitted to the analog-to-digital conversion unit.

7. The driving circuit according to claim 3 or 4, wherein the detection compensation module comprises a plurality of detection compensation units, a gating unit and an analog-to-digital conversion unit;

each detection compensation unit is connected to the gating module so as to be connected with one corresponding switching unit through the gating module, and each detection compensation unit comprises an integration unit, a fifth switch and a first capacitor;

the integration unit comprises a first input end, a second input end and an output end, the first input end of the integration unit is connected to the gating module, and the second input end of the integration unit is used for receiving a first reference voltage;

the gating unit is respectively connected with the output ends of the plurality of integrating units and is used for controlling the integrating units to be sequentially connected with the analog-to-digital conversion unit.

8. The driving circuit according to claim 7, wherein a duty cycle of the driving circuit in the detection mode includes a preset voltage phase, a detection phase and a sampling and converting phase;

in the detection phase, the integration unit in each detection compensation unit transmits charges to the gating module, and the charges of the first capacitors flow into the OLED device through the corresponding induction lines to form a current path;

in the sampling and converting stage, the current path is cut off, and the voltage at the output end of the integrating unit in each detection and compensation unit is sequentially transmitted to the analog-to-digital conversion unit.

9. A method of driving an OLED display panel as claimed in any one of claims 1 to 8, the method comprising:

acquiring the charge quantity flowing through the OLED device in each sub-pixel unit in a preset detection time in a detection mode and detecting a voltage difference value corresponding to the charge quantity;

obtaining a compensation gain value corresponding to each sub-pixel unit according to the voltage difference value;

and acquiring a compensated gray-scale value corresponding to each sub-pixel unit after compensation by using the compensation gain value in a display mode and displaying the compensated gray-scale value.

10. The driving method according to claim 9, wherein the compensation gain value corresponding to each of the sub-pixel units satisfies the following formula:

wherein, Δ V and Δ V₀The voltage difference values are respectively corresponding to the charge quantity of the OLED device passing through each sub-pixel unit in the preset detection time at the current moment and in the factory; v_OUTThe voltage value is acquired at the output end of the integration unit after the preset detection time at the current moment; v_{OUT_0}The initial voltage value is acquired at the output end of the integration unit after the preset detection time when leaving a factory; v_RSFA reference voltage value provided for the integration unit; gain is a compensation Gain value corresponding to each sub-pixel unit.