CN119479552B

CN119479552B - Circuits, electronic devices and methods for improving color distortion in displays

Info

Publication number: CN119479552B
Application number: CN202411940674.XA
Authority: CN
Inventors: 范昌辉
Original assignee: Vivo Mobile Communication Co Ltd
Current assignee: Vivo Mobile Communication Co Ltd
Priority date: 2024-12-26
Filing date: 2024-12-26
Publication date: 2026-04-03
Anticipated expiration: 2044-12-26
Also published as: CN119479552A

Abstract

The application discloses a circuit, electronic equipment and a method for improving display color cast, and belongs to the technical field of display. The circuit comprises a driving and regulating module, a light-emitting element and a driving and regulating module, wherein the driving and regulating module is used for providing driving current for the light-emitting element based on a light-emitting signal, the driving current is regulated based on a pixel driving control signal so as to regulate the light-emitting brightness of corresponding pixels of the light-emitting element, the light-emitting element is connected with the driving and regulating module and is used for emitting light under the action of the driving current provided by the driving and regulating module, and the pixel driving control signal represents that display is in a color cast state.

Description

Circuit, electronic equipment and method for improving display color cast

Technical Field

The application belongs to the technical field of display, and particularly relates to a circuit, electronic equipment and a method for improving display color cast.

Background

AMOLED (Active Matrix Organic LIGHT EMITTING Diode) display technology has the characteristics of high contrast ratio, high response speed, wide viewing angle, wide color gamut and the like, and is widely applied to smart phones and smart watches at present. The pixel driving circuit of the AMOLED is generally composed of a plurality of TFTs (Thin Film Transistor, thin film transistors).

After the TFT device is used for a long time or in a high temperature and high humidity environment, aging generally occurs, so that the current of the driving TFT increases, and the brightness of the light emitting diode is increased. In the light emitting diode, the light emitting efficiency of the G (green) pixel material is highest, and the light emitting efficiencies of the R (red) and B (blue) pixel light emitting materials are relatively low. Therefore, under the condition of increasing the same current, the increased light-emitting brightness of the green pixel material is the greatest, the increased light-emitting brightness of the red and blue pixel materials is less, and finally, the proportion of green light after the red, green and blue pixels are mixed with light is more, and the screen display is color-shifted and green-shifted as a whole.

Disclosure of Invention

The embodiment of the application aims to provide a circuit, electronic equipment and a method for improving display color cast, which can solve the problem of screen display color cast in the related technology.

In a first aspect, an embodiment of the present application provides a circuit for improving color cast of a display, including:

The driving and regulating module is used for providing driving current for the light-emitting element based on the light-emitting signal (EM n), and regulating the driving current based on the pixel driving control signal (Scan n) so as to regulate the light-emitting brightness of the corresponding pixel of the light-emitting element;

the light-emitting element is connected with the driving and regulating module and is used for emitting light under the action of driving current provided by the driving and regulating module;

Wherein the pixel drive control signal (Scan n) characterizes the display in a color cast state.

In a second aspect, an embodiment of the present application provides an electronic device, including a display panel and a circuit for improving display color cast as described in the first aspect above.

In a third aspect, an embodiment of the present application provides a method for improving display color cast, which is applied to the circuit for improving display color cast according to the first aspect, and the method includes:

Detecting a current temperature or an accumulated display time;

The driving and regulating module provides driving current to the light-emitting element based on the light-emitting signal (EM n) to make the light-emitting element emit light;

The driving and regulating module regulates the driving current based on a pixel driving control signal (Scan n) to regulate the light-emitting brightness of the corresponding pixel of the light-emitting element.

In a fourth aspect, an embodiment of the present application provides an electronic device, including a processor and a memory storing a program or instructions executable on the processor, the program or instructions implementing the steps of the method for improving display color cast according to the third aspect when executed by the processor.

In a fifth aspect, embodiments of the present application provide a readable storage medium having stored thereon a program or instructions which when executed by a processor implement the steps of the method of improving display color cast as described in the third aspect.

In a sixth aspect, an embodiment of the present application provides a chip, where the chip includes a processor and a communication interface, where the communication interface is coupled to the processor, and the processor is configured to execute a program or instructions to implement a method for improving color cast of a display according to the third aspect.

In a seventh aspect, embodiments of the present application provide a computer program product stored in a storage medium, the program product being executable by at least one processor to implement a method of improving display color cast as described in the third aspect.

In the embodiment of the application, the driving and regulating module provides the driving current for the light-emitting element based on the light-emitting signal, the light-emitting element emits light under the action of the driving current, and the driving and regulating module regulates the driving current based on the pixel driving control signal representing that the display is in the color cast state, so that the light-emitting brightness of the corresponding pixel of the light-emitting element can be regulated, thereby improving the problem of color cast of the display and improving the display effect.

Drawings

Fig. 1 is a schematic diagram of a structure of a 7t1c LTPS pixel driving circuit in the related art;

Fig. 2 is a timing chart of a 7t1c LTPS pixel driving circuit in the related art;

FIG. 3 is a graph showing the comparison of the performance of the OLED of the related art after long-term use;

FIG. 4 is a schematic diagram of a circuit structure for improving color cast of a display according to an embodiment of the present application;

FIG. 5 is a schematic diagram of another circuit structure for improving color cast of a display according to an embodiment of the present application;

FIG. 6 is a schematic diagram of a circuit structure for improving color cast of a display according to an embodiment of the present application;

FIG. 7 is a schematic diagram of a circuit structure for improving color cast of a display according to an embodiment of the present application;

FIG. 8 is a schematic diagram of a circuit structure for improving color cast of a display according to an embodiment of the present application;

FIG. 9 is a timing diagram of driving the circuit of FIG. 8 according to an embodiment of the present application;

FIG. 10 is a schematic diagram of a transfer characteristic of a P-type transistor according to an embodiment of the present application;

FIG. 11 is a schematic diagram of a circuit structure for improving color cast of a display according to an embodiment of the present application;

FIG. 12 is a schematic diagram of a circuit structure for improving color cast of a display according to an embodiment of the present application;

FIG. 13 is a timing diagram of driving the circuit of FIG. 12 according to an embodiment of the present application;

FIG. 14 is a schematic diagram of a circuit structure for improving color cast of a display according to an embodiment of the present application;

FIG. 15 is a schematic diagram of a circuit structure for improving color cast of a display according to an embodiment of the present application;

FIG. 16 is a schematic diagram of GOA generated pixel driving control signals provided by an embodiment of the present application;

FIG. 17 is a flowchart of a method for improving color cast of a display according to an embodiment of the present application;

Fig. 18 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Detailed Description

The technical solutions of the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which are obtained by a person skilled in the art based on the embodiments of the present application, fall within the scope of protection of the present application.

The terms first, second and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged, as appropriate, such that embodiments of the present application may be implemented in sequences other than those illustrated or described herein, and that the objects identified by "first," "second," etc. are generally of a type, and are not limited to the number of objects, such as the first object may be one or more. Furthermore, in the description and claims, "and/or" means at least one of the connected objects, and the character "/", generally means that the associated object is an "or" relationship.

For a better understanding of the technical solution provided by the present application, some concepts and/or terms related to the present application will be explained first.

The circuit for improving the display color cast provided by the embodiment of the application is obtained by improving the pixel driving circuit, and can achieve the effect of improving the display color cast. The pixel driving circuit used in the embodiments of the present application may be of various types, including but not limited to, 7t1c LTPS (Low Temperature Polycrystalline Silicon, low-temperature polysilicon), 7t1c LTPO (Low Temperature Polycrystalline Oxide, low-temperature polysilicon oxide), 8t1c LTPS or 8t1c LTPO, and the like.

The operation of the pixel driving circuit will be described below taking the 7t1c LTPS type as an example. Fig. 1 is a schematic diagram showing the structure of a 7t1c LTPS pixel driving circuit. As shown in fig. 1, the pixel driving circuit includes 7 TFTs (T1 to T7), 1 capacitor Cst, and 1 OLED (Organic LIGHT EMITTING Diode). The 7 TFTs may be P-type or N-type, and P-type TFTs are shown in the figure, and are in an on state when in a low level and in an off state when in a high level. The driving timing process of the pixel driving circuit may include the following 4 stages during one frame time of the display refresh, which is described in detail with reference to the timing diagram of fig. 2.

(1) In the T1 stage (capacitor reset stage), the n-1 th row gate Scan signal Scan [ n-1] is low, T4 is turned on, and the first voltage Vint1 (negative voltage) is written into the gate of T1 and stored in the capacitor Cst for holding.

(2) In the T2 stage (DATA writing and threshold voltage compensation stage), the n-th row gate Scan signal Scan [ n ] is low, T2 and T3 are turned on, while T1 is also turned on while the negative voltage Vint1 of the capacitor Cst is maintained, the DATA voltage signal DATA is transmitted along T2, T1 and T3, and finally stored in the capacitor Cst, until T1 is turned off when the voltage on the capacitor Cst becomes Vdata-vth|. Vdata is an input data voltage, and Vth is a threshold voltage of T1 itself. By this operation, the threshold voltage Vth of T1 is extracted, and the voltage of T1 is compensated.

(3) And a T3 stage (OLED reset stage) in which the n+1th row gate Scan signal Scan [ n+1] is low level, T7 is turned on, a second voltage Vint2 (negative voltage) is written to the anode of the OLED, the OLED is reset, and the residual charges accumulated in the OLED are discharged.

(4) And a T4 stage (light emitting stage) in which the gate Scan signals Scan [ n-1], scan [ n ] and Scan [ n+1] are all at high level, T2, T3, T4 and T7 are turned off, the n-th row light emission control gate Scan signal EM [ n ] is at low level, T5 and T6 are turned on, at this time, the gate of T1 is in an on state under the action of the storage voltage Vdata-Vth| of the capacitor Cst, and current flows from the positive power supply voltage ELVDD to the OLED to the negative power supply voltage ELVSS after flowing through T5, T1 and T6, and the OLED emits light. Wherein ELVDD is a constant positive voltage, typically 4.6v, and elvss is a negative voltage that can be regulated by the display driver chip controlling the power chip output.

Fig. 3 is a comparative schematic diagram of performance of the OLED of the related art after long-term use. In the initial state, the light emitting efficiency of the green pixel material in the OLED is highest, and the light emitting efficiencies of the red and blue pixel materials are relatively low. In order to prevent color shift after the red, green and blue pixels emit light and mix colors, the light emitting area of G green light is usually minimized, the data voltage Vdata of G green light is also minimized, and the light emitting areas of R red light and B blue light are relatively large, and the data voltages Vdata of R red light and B blue light are also relatively large. Under the design, the data voltage Vdata is matched with the light emitting area, so that the light emitting brightness of G green light, R red light and B blue light is matched, and white light is mixed without color cast.

However, after the screen is used for a long time or operated in a high temperature and high humidity environment for a long time, due to the aging of the TFT device characteristics, the current flowing through the driving transistor T1 increases with the same data voltage Vdata, resulting in higher luminance of the OLED light emission, for example, the luminance of G green light increases from 120nit to 360nit, and the luminance increases more than R red light and B blue light. Therefore, the final red, green and blue pixels are mismatched in luminous brightness, resulting in color cast of the screen display and overall green cast.

In view of the above, the embodiments of the present application provide a circuit, an electronic device and a method for improving color cast of a display, wherein the current of a light emitting element is controlled to be reduced by a current regulation module, so as to overcome the problem of color cast of the display caused by current increase. The current regulation module may be implemented by a TFT, for example, by adding a T8 as a current regulation module to the 7T1c LTPS pixel driving circuit, thereby becoming a circuit for improving display color cast of 8T1c LTPS, or by modifying a light emission control transistor in the 7T1c LTPS pixel driving circuit as a current regulation module, thereby becoming a circuit for improving display color cast of 7T1c LTPS. For another example, a T9 is added as a current regulation module on the basis of the 8T1c LTPO pixel driving circuit, so as to become a circuit for improving display color cast of 9T1c LTPO, and the embodiment of the application is not limited in particular. The light emitting element includes, but is not limited to, OLED, AMOLED, etc., and is not particularly limited.

The circuit for improving the display color cast can be applied to various electronic equipment, including but not limited to intelligent terminal equipment such as mobile phones, watches or flat panels, and the like, and is particularly not limited. The electronic device can comprise the circuit for improving display color cast and a display panel, wherein the display panel comprises, but is not limited to, an OLED display panel or an AMOLED display panel.

The circuit, the electronic device and the method for improving the display color cast provided by the embodiment of the application are described in detail below through specific embodiments and application scenes thereof with reference to the accompanying drawings.

Fig. 4 shows a circuit for improving color cast of a display according to an embodiment of the application, and as shown in fig. 4, the circuit includes a driving and adjusting module 100 and a light emitting element 200.

The driving and adjusting module 100 is configured to provide a driving current to the light emitting element 200 based on the light emitting signal EM [ n ], and adjust the driving current based on the pixel driving control signal Scan [ n ] to adjust the light emitting brightness of the corresponding pixel of the light emitting element 200.

The light emitting element 200 is connected to the driving and adjusting module 100, and is used for emitting light under the action of the driving current provided by the driving and adjusting module 100.

Wherein the pixel drive control signal Scan n characterizes the display in a color cast state.

In the embodiment of the present application, the light emitting signal EM [ n ] may be generated by a GOA (Gate On Array). In one frame time of the display refresh, the GOA generates a light emission signal EM n in a t4 stage (light emission stage) to drive the light emitting element 200 to emit light.

The GOA may be located on the left side of the screen, or on the right side of the screen, or on the left side and the right side of the screen, respectively, which is not particularly limited in the embodiment of the present application.

In the embodiment of the application, the driving process of the circuit for improving the display color cast comprises a reset data writing compensation stage and a light emitting stage. Accordingly, the pixel driving control signal Scan [ n ] may include at least one of:

1) The green sub-pixel driving control signal ScanG [ n ], wherein the voltage of the green sub-pixel driving control signal ScanG [ n ] is lower in the light-emitting period than in the reset data writing compensation period.

In this scenario, the green sub-pixel generates a color shift, that is, the color after color mixing is shifted to green, and the driving current is reduced in the light emitting stage by the green sub-pixel driving control signal ScanG [ n ], so that the light emitting brightness of the green pixel of the light emitting element 200 is reduced, and the display condition of shifted to green can be improved.

2) The red subpixel driving control signal ScanR [ n ], wherein the voltage of the red subpixel driving control signal ScanR [ n ] is lower in the light-emitting phase than in the reset data write compensation phase.

In this scenario, the red subpixel is colored, that is, the color of the red subpixel is colored in a color after color mixing, and the driving current is reduced in the light emitting stage by the red subpixel driving control signal ScanR [ n ], so that the light emitting brightness of the red pixel of the light emitting element 200 is reduced, and the condition of displaying the color in a color deviation can be improved.

3) The blue subpixel driving control signal ScanB [ n ], wherein the blue subpixel driving control signal ScanB [ n ] has a lower voltage in the light-emitting phase than in the reset data write compensation phase.

In this scenario, the blue subpixel is colored, that is, the color of the blue subpixel is colored after color mixing, and the driving current is reduced in the light emitting stage by the blue subpixel driving control signal ScanB [ n ], so that the light emitting brightness of the blue pixel of the light emitting element 200 is reduced, and the blue display condition can be improved.

The three scenarios may be combined, and one, two or three of the green subpixel drive control signal ScanG [ n ], the red subpixel drive control signal ScanR [ n ] and the blue subpixel drive control signal ScanB [ n ] may be used simultaneously to overcome the problem of color cast of the display.

For example, if the display is both green and red, the green subpixel drive control signal ScanG [ n ] and the red subpixel drive control signal ScanR [ n ] are used simultaneously to reduce the drive current, thereby reducing the light emission luminance of the green and red pixels of the light-emitting element 200.

For another example, when the display is both green and blue, the green sub-pixel driving control signal ScanG [ n ] and the blue sub-pixel driving control signal ScanB [ n ] are used simultaneously to reduce the driving current, thereby reducing the light-emitting brightness of the green and blue pixels of the light-emitting element 200.

For another example, if the display is simultaneously shifted to green and red and blue, the driving current is reduced by simultaneously using the green subpixel driving control signal ScanG [ n ], the red subpixel driving control signal ScanR [ n ], and the blue subpixel driving control signal ScanB [ n ], thereby reducing the light-emitting brightness of the green, red, and blue pixels of the light-emitting element 200.

In the embodiment of the application, the color cast degree of the red, green and blue sub-pixels may be different. If the first sub-pixel color cast degree is higher than the second sub-pixel color cast degree, the voltage of the first sub-pixel driving control signal is reduced by a higher magnitude than that of the second sub-pixel driving control signal in the light emitting stage, so that the light emitting brightness of the two sub-pixels can be matched. The first sub-pixel may be any one of green, red and blue sub-pixels, and the second sub-pixel may be any one of green, red and blue sub-pixels, and the two sub-pixels are sub-pixels of different colors.

For example, if the display is both greenish and reddish, but the green sub-pixel is more colored, i.e., the overall color is more greenish, then the green sub-pixel drive control signal ScanG [ n ] and the red sub-pixel drive control signal ScanR [ n ] can be used together to reduce the drive current. In the light emitting stage from the reset data writing compensation stage to the light emitting stage, the voltage of the green sub-pixel driving control signal is reduced from a low level of-10V to-5V, and the voltage of the red sub-pixel driving control signal is reduced from a low level of-10V to-8V, thereby reducing the light emitting luminance of the green and red sub-pixels of the light emitting element 200, and reducing the light emitting luminance of the green sub-pixel more so that the light emitting luminance of the green and red sub-pixels is matched.

Referring to fig. 5 and 6, the driving and regulating module 100 may include a light emission control and driving unit 10 and a current regulating unit 20 in an embodiment of the present application.

The light emission control and driving unit 10 and the current regulation unit 20 are connected in series, one end of the light emission control and driving unit 10 is connected with a light emission signal EM n, and one end of the current regulation unit 20 is connected with a pixel driving control signal Scan n.

The light emission control and driving unit 10 is configured to supply a driving current to the light emitting element 200 based on the light emission signal EM [ n ]. The current regulation unit 20 is configured to regulate the driving current based on the pixel driving control signal Scan [ n ] to regulate the light emitting luminance of the corresponding pixel of the light emitting element 200.

As shown in fig. 5, one end of the current regulation unit 20 is connected to the light emitting element 200. Or as shown in fig. 6, one end of the light emission control and driving unit 10 is connected to the light emitting element 200.

Referring to fig. 5, one end of the current regulation unit 20 is connected to the light emitting element 200, and the circuit according to the embodiment of the present application may further include a light emitting element reset module 300.

One end of the light emitting element reset module 300 is connected to the second voltage Vint2, and the other end of the light emitting element reset module 300 is connected to the first node D1. The first node D1 is a connection node between the light emission control and driving unit 10 and the current regulation unit 20. The light emitting element reset module 300 is configured to reset the light emitting element 200 based on the second voltage Vint 2.

Referring to fig. 6, one end of the light-emitting control and driving unit 10 is connected to the light-emitting element 200, and the circuit according to the embodiment of the present application may further include a light-emitting element resetting module 300.

One end of the light emitting element reset module 300 is connected to the second voltage Vint2, and the other end of the light emitting element reset module 300 is connected to the second node D2. The second node D2 is a connection node between the light emission control and driving unit 10 and the light emitting element 200. The light emitting element reset module 300 is configured to reset the light emitting element 200 based on the second voltage Vint 2.

According to the circuit provided by the embodiment of the application, the driving and regulating module provides the driving current for the light-emitting element based on the light-emitting signal, the light-emitting element emits light under the action of the driving current, and the driving and regulating module regulates the driving current based on the pixel driving control signal representing that the display is in the color cast state, so that the light-emitting brightness of the corresponding pixel of the light-emitting element can be regulated, the problem of color cast of the display is solved, and the display effect is improved.

Fig. 7 shows another circuit for improving color cast of a display according to an embodiment of the present application, which is exemplified by adding a first current adjusting unit to a pixel driving circuit. As shown in fig. 7, the circuit includes a driving and controlling module 100 and a light emitting element 200. The driving and regulating module 100 includes a first light emitting control unit 11, a driving unit 12, a second light emitting control unit 13, and a first current regulating unit 21 connected in series.

Wherein, the first light emitting control unit 11 and the second light emitting control unit 13 are both connected to the light emitting signal EM [ n ], and are both in an on state when the light emitting signal EM [ n ] is at the first level.

In the embodiment of the present application, the first level may be a high level or a low level, which is determined by which type of TFT is used by the first light emitting control unit 11. For example, the first light emitting control unit 11 uses a P-type TFT, and the first level is low, i.e., in an on state in the case of a low level and in an off state in the case of a high level. For another example, the first light emitting control unit 11 uses an N-type TFT, and the first level is high, i.e., is in an on state in the case of a high level, and is in an off state in the case of a low level.

Wherein the driving unit 12 is in an on state in case that the data voltage is greater than the threshold voltage of the driving unit 12.

The first current regulation unit 21 is always in an on state during the driving process of the above circuit, and has one end connected to the pixel driving control signal Scan [ n ], and the other end connected to the light emitting element 200.

Wherein, in a case where the first light emission control unit 11, the driving unit 12, the second light emission control unit 13, and the first current regulation unit 21 are all in an on state, a driving current is supplied to the light emitting element 200.

The first current adjusting unit 21 is configured to adjust (e.g. decrease) the driving current based on the pixel driving control signal Scan [ n ] to adjust (e.g. decrease) the light emitting brightness of the corresponding pixel of the light emitting element 200.

In an embodiment of the present application, the above circuit may further include:

the light emitting element reset module 300 has one end connected to the second voltage Vint2 and the other end connected to the first node D1, and is configured to reset the light emitting element 200 based on the second voltage Vint2 when the first current regulation unit 21 is in an on state. Wherein the first node D1 is a connection node between the second light emission control unit 13 and the first current regulation unit 21.

The specific application scenario of the circuit shown in fig. 5 is described in detail below with reference to fig. 7 and 8. The first current regulation unit is added to the 7t1c LTPS pixel driving circuit. Fig. 7 shows the functions of the respective modules, and fig. 8 shows the connection relationship of the respective devices. As shown in fig. 8, T5 and T6 are a first light emission control unit and a second light emission control unit, respectively, and are both connected to a light emission signal EM [ n ]. T1 is a driving unit. The newly added T8 is a first current regulation unit. The gate of T8 is connected to the pixel drive control signal Scan [ n ], including the red subpixel drive control signal ScanR [ n ], the green subpixel drive control signal ScanG [ n ], and the blue subpixel drive control signal ScanB [ n ]. The source of T8 is connected to T6, which is the second light emission control unit, and the drain of T8 is connected to the light emitting element OLED. T7 is a light emitting element reset module, the source electrode is connected with the second voltage Vint2, and the drain electrode is connected with a connection node between T6 and T8. In the case where the display color cast is caused by an increase in the current flowing through the driving unit T1, the pixel driving control signal Scan [ n ] is generated to reduce the driving current, thereby reducing the light emission luminance of the corresponding sub-pixel of the light emitting element OLED.

Fig. 9 shows a driving timing diagram of the circuit shown in fig. 8. In the case where the devices in fig. 8 are P-type TFTs, if N-type TFTs are used, the driving timing diagram is opposite to the waveforms in fig. 9, and will not be described here again. As shown in fig. 9, the entire driving timing process can be divided into the following 4 stages within one frame time of the display refresh.

(1) In the T1 stage (capacitor reset stage), the n-1 row gate Scan signal Scan n-1 is low, the data reset module T4 is turned on, and the first voltage Vint1 (negative voltage) is written into the gate of the driving unit T1 and stored in the capacitor Cst for holding.

(2) In the T2 stage (DATA writing and threshold voltage compensation stage), the n-th row gate Scan signal Scan [ n ] is at a low level, the DATA writing module T2 and the threshold voltage compensation module T3 are turned on, while the driving unit T1 is also in an on state while the negative voltage Vint1 of the capacitor Cst is maintained, the DATA voltage signal DATA is transmitted along T2, T1 and T3, and finally stored in the capacitor Cst until T1 is turned off when the voltage on the capacitor Cst becomes Vdata- |vth|. Vdata is an input data voltage, and Vth is a threshold voltage of T1 itself. By this operation, the threshold voltage Vth of T1 is extracted, and the voltage of T1 is compensated.

In the above-mentioned T1-T3 stage, the pixel driving control signals ScanR [ n ], scanG [ n ], scanB [ n ] all output low-level 10V voltage, and the first current regulation unit T8 is in an on state.

(4) In the T4 stage (light-emitting stage), the gate Scan signals Scan [ n-1], scan [ n ], scan [ n+1] are all high level, and T2, T3, T4, T7 are all turned off. The n-th row light emission control gate scan signal EM [ n ] is at a low level, and T5 and T6 are turned on, and at this time, the gate of T1 is in an on state under the action of the storage voltage Vdata- |vth| of the capacitor Cst, the pixel driving control signals ScanR [ n ], scanG [ n ], scanB [ n ] all output low levels, and T8 is also in an on state, and after current flows from the positive power supply voltage ELVDD to T5, T1, T6, T8, the current flows to the OLED to the negative power supply voltage ELVSS, and the OLED emits light. Wherein ScanG [ n ], scanR [ n ], scanB [ n ] output-5V, -8V and-7V respectively, regulate and control to reduce the current flowing through G, R, B three OLEDs, so that the luminous brightness of G, R, B sub-pixels is matched, and the problem of color cast display is improved. The voltage drop of the green sub-pixel is maximum, the luminous brightness is also reduced to the maximum, and the problem of greenish overall can be improved.

Fig. 10 shows a schematic diagram of a transfer characteristic of a P-type transistor. As shown in fig. 10, when the first current steering unit employs a P-type TFT, the pixel driving control signal Scan [ n ] connected to the gate is in an on state (a region where the voltage is negative in the figure) when it is in a low level, and in an off state (a region where the voltage is positive in the figure) when it is in a high level. In the period t 1-t 3, the pixel driving control signals Scan [ n ] all output-10V. In the t4 stage, the pixel driving control signals ScanR [ n ], scanB [ n ], scanG [ n ] output-8V, -7V, and-5V voltages, respectively. It can be seen that in the case of voltage drop, the source-drain current is correspondingly reduced, so that the light-emitting brightness of the sub-pixels of each color of the OLED can be reduced.

Fig. 11 shows a circuit for improving color cast of a display according to an embodiment of the present application, which is exemplified by modifying an original second light-emitting control unit into a second current regulation unit. As shown in fig. 11, the circuit includes a driving and controlling module 100 and a light emitting element 200. The driving and regulating module 100 includes a first light emitting control unit 11, a driving unit 12, and a second current regulating unit 22 connected in series.

The first light emitting control unit 11 is connected to the light emitting signal EM [ n ], and is in an on state when the light emitting signal EM [ n ] is at a first level.

In the embodiment of the present application, the first level may be a high level or a low level, which is determined by which type of TFT is used by the first light emitting control unit 11. For example, the first light emitting control unit 11 uses a P-type TFT, and the first level is low, i.e., in an on state in the case of a low level and in an off state in the case of a high level.

One end of the second current regulation unit 22 is connected to the pixel driving control signal Scan [ n ], and the other end is connected to the light emitting element 200, and is in an on state when the pixel driving control signal Scan [ n ] is at a first level, and is in an off state when the pixel driving control signal Scan [ n ] is at a second level.

In the embodiment of the present application, the first level may be a high level or a low level, which is determined by which type of TFT is used by the second current steering unit 22. For example, the second current steering unit 22 uses a P-type TFT, and the first level is low, i.e., in an on state in the case of a low level and in an off state in the case of a high level. For another example, the second current steering unit 22 uses an N-type TFT, and the first level is high, i.e., is in an on state in the case of a high level, and is in an off state in the case of a low level.

In the case where the first light emitting control unit 11, the driving unit 12, and the second current regulating unit 22 are all in the on state, the driving current is supplied to the light emitting element 200.

The second current adjusting unit 22 is configured to adjust (e.g. decrease) the driving current based on the pixel driving control signal Scan [ n ] to adjust (e.g. decrease) the light emitting brightness of the corresponding pixel of the light emitting element 200 in the on state.

the light emitting element reset module 300 has one end connected to the second voltage Vint2 and the other end connected to the second node D2, and is configured to reset the light emitting element 200 based on the second voltage Vint2 when the second current regulation unit 232 is in the off state. The second node D2 is a connection node between the second current steering unit 22 and the light emitting element 200.

The specific application scenario of the circuit shown in fig. 6 is described in detail below in conjunction with fig. 11 and 12. The description will be given taking, as an example, the modification of the original light emission control unit in the 7t1c LTPS pixel driving circuit to the second current regulation unit. Fig. 11 shows the functions of the respective modules, and fig. 12 shows the connection relationship of the respective devices. As shown in fig. 12, T5 is a first light emitting control unit, and is connected to a light emitting signal EM n. T1 is a driving unit. And the transformed T6 is a second current regulation and control unit. The gate of T6 is connected to the pixel drive control signal Scan [ n ], including the red subpixel drive control signal ScanR [ n ], the green subpixel drive control signal ScanG [ n ], and the blue subpixel drive control signal ScanB [ n ]. The source of T6 is connected to T1, and the drain is connected to the light emitting element OLED. T7 is a light emitting element reset module, the source electrode is connected with the second voltage Vint2, and the drain electrode is connected with a connection node between the T6 and the OLED. In the case where the display color cast is caused by an increase in the current flowing through the driving unit T1, the pixel driving control signal Scan [ n ] is generated to reduce the driving current, thereby reducing the light emission luminance of the corresponding sub-pixel of the light emitting element OLED.

Fig. 13 shows a driving timing diagram of the circuit shown in fig. 12. In the case where the devices in fig. 12 are P-type TFTs, if N-type TFTs are used, the driving timing diagram is opposite to the waveforms in fig. 13, and will not be described here again. As shown in fig. 13, the entire driving timing process can be divided into the following 4 stages within one frame time of the display refresh.

In the above-mentioned T1-T3 stage, the pixel driving control signals ScanR [ n ], scanG [ n ], scanB [ n ] all output the high level 10V voltage, and the second current regulation unit T6 is in the off state.

(4) In the T4 stage (light-emitting stage), the gate Scan signals Scan [ n-1], scan [ n ], scan [ n+1] are all high level, and T2, T3, T4, T7 are all turned off. The n-th row light emission control gate scan signal EM [ n ] is at a low level, and T5 and T6 are turned on, and at this time, the gate of T1 is in an on state under the action of the storage voltage Vdata- |vth| of the capacitor Cst, the pixel driving control signals ScanR [ n ], scanG [ n ], scanB [ n ] all output low levels, and T6 is also in an on state, and after current flows from the positive power supply voltage ELVDD to T5, T1, T6, current flows to the OLED to the negative power supply voltage ELVSS, and the OLED emits light. Wherein ScanG [ n ], scanR [ n ], scanB [ n ] output-5V, -8V and-7V respectively, regulate and control to reduce the current flowing through G, R, B three OLEDs, so that the luminous brightness of G, R, B sub-pixels is matched, and the problem of color cast display is improved. The voltage drop of the green sub-pixel is maximum, the luminous brightness is also reduced to the maximum, and the problem of greenish overall can be improved. Fig. 9 is a graph of voltage drop versus driving current change for each sub-pixel, and will not be described here.

Fig. 14 shows a circuit for improving color cast of a display according to an embodiment of the present application, which is exemplified by modifying an original first light emitting control unit into a third current regulation unit. As shown in fig. 14, the circuit includes a driving and controlling module 100 and a light emitting element 200. The driving and regulating module 100 includes a third current regulating unit 23, a driving unit 12 and a second light emitting control unit 13 connected in series.

One end of the third current regulation unit 23 is connected to the pixel driving control signal Scan [ n ], and is in an on state when the pixel driving control signal Scan [ n ] is at the first level, and is in an off state when the pixel driving control signal Scan [ n ] is at the second level.

In the embodiment of the present application, the first level may be a high level or a low level, which is determined by which type of TFT is used by the third current steering unit 23. For example, the third current steering unit 23 uses a P-type TFT, and the first level is low, i.e., in an on state in the case of a low level and in an off state in the case of a high level. For another example, the third current steering unit 23 uses an N-type TFT, and the first level is high, i.e., is in an on state in the case of a high level, and is in an off state in the case of a low level.

One end of the second light emission control unit 13 is connected to the light emission signal EM [ n ], and the other end is connected to the light emitting element 200, and is turned on when the light emission signal EM [ n ] is at the first level.

In the embodiment of the present application, the first level may be a high level or a low level, which is determined by which type of TFT is used by the second light emission control unit 13. For example, the second light emission control unit 13 uses a P-type TFT, and the first level is low, i.e., in an on state in the case of a low level and in an off state in the case of a high level.

Wherein, in a case where the third current regulation unit 23, the driving unit 12, and the second light emission control unit 13 are all in an on state, a driving current is supplied to the light emitting element 200.

The third current regulation unit 23 is configured to regulate (e.g., decrease) the driving current based on the pixel driving control signal Scan [ n ] to regulate (e.g., decrease) the light emission luminance of the corresponding pixel of the light emitting element 200 in the on state.

The light emitting element resetting module 300 has one end connected to the second voltage Vint2 and the other end connected to the third node D3, and is configured to reset the light emitting element 200 based on the second voltage Vint2 when the third current regulation unit 23 is in the off state, where the third node D3 is a connection node between the second light emitting control unit 13 and the light emitting element 200.

The specific application scenario of the circuit shown in fig. 6 is described in detail below in conjunction with fig. 14 and 15. The description will be given taking, as an example, the modification of the original light emission control unit in the 7t1c LTPS pixel driving circuit to the third current regulation unit. Fig. 14 shows the functions of the respective modules, and fig. 15 shows the connection relationship of the respective devices. As shown in fig. 15, T6 is a second light emission control unit, and is connected to a light emission signal EM [ n ]. T1 is a driving unit. And the transformed T5 is a third current regulation and control unit. The gate of T5 is connected to the pixel drive control signal Scan [ n ], including the red subpixel drive control signal ScanR [ n ], the green subpixel drive control signal ScanG [ n ], and the blue subpixel drive control signal ScanB [ n ]. The source of T5 is connected to ELVDD and the drain is connected to T1. T7 is a light emitting element reset module, the source electrode is connected with the second voltage Vint2, and the drain electrode is connected with a connection node between the T6 and the OLED. In the case where the display color cast is caused by an increase in the current flowing through the driving unit T1, the pixel driving control signal Scan [ n ] is generated to reduce the driving current, thereby reducing the light emission luminance of the corresponding sub-pixel of the light emitting element OLED. The driving timing chart of the above circuit may refer to fig. 13, and in a frame time of display refresh, the entire driving timing includes 4 stages, and the corresponding description of fig. 13 is also referred to, which is not repeated here.

In an embodiment of the present application, the pixel driving control signal Scan [ n ] related to any of the above embodiments may be generated by GOA. The gate driving circuit may be located at the left side of the screen, or at the right side of the screen, or at the left side and the right side of the screen, respectively, and is not particularly limited. The embodiments of the present application are not limited in particular, and the embodiments of the present application belong to a single-drive scene on the left side and on the right side, and belong to a double-drive scene on the left side and the right side.

Fig. 16 is a schematic diagram of GOA generation pixel driving control signals according to an embodiment of the present application. As shown in fig. 16, the pixel driving control signals ScanR n, scanG n, scanB n are generated by the gate driving circuits placed in the black GOA region of the right frame of the screen, and are respectively connected to the R, G, B subpixel driving circuits in one row of pixels in the AA (ACTIVE AREA, actual display pixel light emitting area) region. In the figure, a single-drive scene is shown, and the GOA zone is arranged on one side of the screen only. Wherein, 1 pushes 1 means that 1 GOA circuit module drives 1 row of pixels.

The embodiment of the application also provides electronic equipment, which can comprise a display panel and the circuit for improving display color cast, wherein the function of the circuit is the same as that described in the embodiment, and the same technical effects can be achieved, and the circuit is not repeated here.

Referring to fig. 17, a flowchart of a method for improving color cast of a display according to an embodiment of the present application is shown. As shown in fig. 17, the method is applied to the circuit for improving display color cast according to any of the above embodiments, and specifically includes the following steps.

S1702, providing driving current to the light-emitting element based on the light-emitting signal EM [ n ] to make the light-emitting element emit light.

S1704, adjusting the driving current based on the pixel driving control signal Scan [ n ] to adjust the light emission luminance of the corresponding pixel of the light emitting element.

In the embodiment of the present application, the step S1704 may specifically include:

the driving current is reduced based on the pixel driving control signal Scan [ n ] to reduce the light emission luminance of the corresponding pixel of the light emitting element.

In the embodiment of the present application, before the step S1702, the method may further include:

and acquiring the pixel driving control signal when the display is in a color cast state.

In one embodiment, the pixel drive control signal (Scan [ n ]) characterizes the current temperature as being greater than a first threshold or the cumulative display time as being greater than a second threshold.

In an embodiment of the present application, the pixel driving control signal (Scan [ n ]) may be generated by:

the current temperature or the accumulated display time is detected, and the pixel driving control signal Scan [ n ] is generated in the case where the current temperature is greater than the first threshold or the accumulated display time is greater than the second threshold.

The first threshold and the second threshold may be set as required, and specific values are not limited. For example, the first threshold is 50 degrees, the second threshold is 1 year, and so on.

Wherein the pixel driving control signal Scan [ n ] includes at least one of a red sub-pixel driving control signal ScanR [ n ], a green sub-pixel driving control signal ScanG [ n ] and a blue sub-pixel driving control signal ScanB [ n ]. The voltage of any one sub-pixel driving control signal in the light-emitting stage is lower than the voltage of any one sub-pixel driving control signal in the reset data writing compensation stage. In practical application, which color is color cast, the sub-pixel driving control signal of the corresponding color is generated, so that the color cast problem is overcome.

The voltage values output by the red sub-pixel driving control signal ScanR [ n ], the green sub-pixel driving control signal ScanG [ n ] and the blue sub-pixel driving control signal ScanB [ n ] can be linearly increased and adjusted within a voltage range of-10V to 10V according to the current temperature or the accumulated display time.

According to the method provided by the embodiment of the application, the driving current is provided for the light-emitting element based on the light-emitting signal EM [ n ], so that the light-emitting element emits light, and the driving current is adjusted based on the pixel driving control signal Scan [ n ] representing that the display is in a color cast state, so that the light-emitting brightness of the corresponding pixel of the light-emitting element is adjusted, thereby improving the problem of color cast of the display and improving the display effect.

Referring to fig. 18, a schematic structural diagram of an electronic device according to an embodiment of the present application is provided. As shown in fig. 18, the embodiment of the present application further provides an electronic device 1800, which includes a processor 1801 and a memory 1802, where the memory 1802 stores a program or instructions that can be executed on the processor 1801, and the program or instructions implement the steps of the method embodiment for improving display color cast when executed by the processor 1801, and achieve the same technical effects, so that repetition is avoided and no further description is given here.

It should be noted that, the electronic device in the embodiment of the present application includes a mobile electronic device and a non-mobile electronic device.

The embodiment of the application also provides a readable storage medium, on which a program or an instruction is stored, which when executed by a processor, implements each process of the above-mentioned method embodiment for improving display color cast, and can achieve the same technical effects, so that repetition is avoided, and no further description is given here.

Wherein the processor is a processor in the electronic device described in the above embodiment. The readable storage medium includes computer readable storage medium such as computer readable memory ROM, random access memory RAM, magnetic or optical disk, etc.

The embodiment of the application further provides a chip, the chip comprises a processor and a communication interface, the communication interface is coupled with the processor, the processor is used for running a program or instructions, the processes of the method embodiment for improving the display color cast can be realized, the same technical effects can be achieved, and the repetition is avoided, and the description is omitted here.

It should be understood that the chips referred to in the embodiments of the present application may also be referred to as system-on-chip chips, chip systems, or system-on-chip chips, etc.

Embodiments of the present application provide a computer program product stored in a storage medium, where the program product is executed by at least one processor to implement the processes of the method embodiments for improving display color cast as described above, and achieve the same technical effects, and for avoiding repetition, a detailed description is omitted herein.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element. Furthermore, it should be noted that the scope of the methods and apparatus in the embodiments of the present application is not limited to performing the functions in the order shown or discussed, but may also include performing the functions in a substantially simultaneous manner or in an opposite order depending on the functions involved, e.g., the described methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

From the above description of the embodiments, it will be clear to those skilled in the art that the above-described embodiment method may be implemented by means of software plus a necessary general hardware platform, but of course may also be implemented by means of hardware, but in many cases the former is a preferred embodiment. Based on such understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art in the form of a computer software product stored in a storage medium (e.g. ROM/RAM, magnetic disk, optical disk) comprising instructions for causing a terminal (which may be a mobile phone, a computer, a server, or a network device, etc.) to perform the method according to the embodiments of the present application.

The embodiments of the present application have been described above with reference to the accompanying drawings, but the present application is not limited to the above-described embodiments, which are merely illustrative and not restrictive, and many forms may be made by those having ordinary skill in the art without departing from the spirit of the present application and the scope of the claims, which are to be protected by the present application.

Claims

1. A circuit for improving color cast of a display, comprising:

Wherein the driving process of the circuit comprises a reset data writing compensation phase and a light emitting phase, the pixel driving control signal (Scan [ n ]) characterizes the display in a color cast state, and the pixel driving control signal (Scan [ n ]) comprises at least one of the following:

A green subpixel driving control signal (ScanG [ n ]), a red subpixel driving control signal (ScanR [ n ]), and a blue subpixel driving control signal (ScanB [ n ]), wherein the voltage of any one subpixel driving control signal in the light-emitting stage and the voltage in the reset data writing compensation stage are both high level or both low level, and the absolute value of the voltage of any one subpixel driving control signal in the light-emitting stage is lower than the absolute value of the voltage of any one subpixel driving control signal in the reset data writing compensation stage;

In the case that the absolute value of the voltage of any one of the pixel driving control signals in the light emitting stage is lower than that of the voltage in the reset data writing compensation stage, the driving and regulating module reduces the driving current in the light emitting stage through any one of the pixel driving control signals.

2. The circuit of claim 1, wherein the drive and regulation module comprises a lighting control and drive unit and a current regulation unit;

The light-emitting control and driving unit is connected in series with the current regulation and control unit, one end of the light-emitting control and driving unit is connected with a light-emitting signal (EM n), and one end of the current regulation and control unit is connected with a pixel driving control signal (Scan n);

The light-emitting control and driving unit is used for providing driving current for the light-emitting element based on the light-emitting signal (EM n);

the current regulating unit is used for regulating the driving current based on a pixel driving control signal (Scan n) so as to regulate the luminous brightness of the corresponding pixel of the luminous element;

one end of the current regulating unit is connected with the light-emitting element, or one end of the light-emitting control and driving unit is connected with the light-emitting element.

3. The circuit according to claim 2, wherein one end of the current regulation unit is connected to the light emitting element, the circuit further comprising:

the light-emitting element reset module, one end of the light-emitting element reset module is connected with a second voltage (Vint 2), the other end of the light-emitting element reset module is connected with a first node (D1), and the first node (D1) is a connecting node between the light-emitting control and driving unit and the current regulation and control unit;

the light emitting element reset module is used for resetting the light emitting element based on a second voltage (Vint 2).

4. The circuit of claim 2, wherein one end of the light emission control and driving unit is connected to the light emitting element, the circuit further comprising:

The light-emitting element reset module, one end of the light-emitting element reset module is connected with a second voltage (Vint 2), the other end of the light-emitting element reset module is connected with a second node (D2), and the second node (D2) is a connecting node between the light-emitting control and driving unit and the light-emitting element;

5. A circuit according to any one of claims 1-4, characterized in that the pixel drive control signal (Scan [ n ]) is generated by a gate drive circuit, which is located on the left side of the screen, or on the right side of the screen, or on the left side and the right side of the screen, respectively.

6. An electronic device comprising a display panel and a circuit for improving display color shift as claimed in any one of claims 1 to 5.

7. A method for improving display color cast, characterized in that it is applied to the circuit for improving display color cast according to any one of claims 1 to 5, the method comprising:

Providing a driving current to the light emitting element based on the light emitting signal (EM n) to cause the light emitting element to emit light;

adjusting the driving current based on a pixel driving control signal (Scan [ n ]) to adjust the light emitting brightness of the corresponding pixel of the light emitting element;

8. A method according to claim 7, characterized in that the pixel drive control signal (Scan [ n ]) characterizes that the current temperature is greater than a first threshold value or that the accumulated display time is greater than a second threshold value.

9. The method according to claim 7 or 8, characterized in that before the supplying of the drive current to the light emitting element based on the light emitting signal, the method further comprises: