Circuit, electronic equipment and method for improving display color cast

Abstract

The invention 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 used for providing a driving current for a light-emitting element based on a light-emitting signal and regulating the driving current based on a pixel driving control signal so as to regulate the light-emitting brightness of a 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 the driving current provided by the driving and regulating module; wherein the pixel driving control signal represents that the display is in a color cast state.

Description

Technical Field

[0001] The present application belongs to the field of display technology, and specifically relates to a circuit, electronic equipment and method for improving display color cast. Background Art

[0002] AMOLED (Active Matrix Organic Light Emitting Diode) display technology has the characteristics of high contrast, fast response speed, wide viewing angle and wide color gamut, and has been widely used in smartphones and smart watches. The pixel driving circuit of AMOLED is usually composed of multiple TFTs (Thin Film Transistors).

[0003] After long-term use or use in high temperature and high humidity environments, TFT devices usually age, causing the current driving the TFT to increase, which in turn causes the brightness of the light-emitting diode to increase. In light-emitting diodes, the luminous efficiency of G (green) pixel materials is the highest, while the luminous efficiency of R (red) and B (blue) pixel luminescent materials is relatively low. Therefore, under the condition of increasing the same current, the green pixel material increases the luminous brightness the most, while the red and blue pixel materials increase the luminous brightness less, which will eventually lead to a higher proportion of green light after the red, green and blue pixels are mixed, and the screen will be colored and green overall. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a circuit, electronic device and method for improving display color cast, which can solve the problem of screen display color cast in related technologies.

[0005] In a first aspect, an embodiment of the present application provides a circuit for improving display color cast, comprising: A driving and regulating module, configured to provide a driving current to the light-emitting element based on a light-emitting signal (EM[n]), and to adjust the driving current based on a pixel driving control signal (Scan[n]) so as to adjust the light-emitting brightness of a corresponding pixel of the light-emitting element; A light-emitting element, connected to the driving and regulating module, and configured to emit light under the action of a driving current provided by the driving and regulating module; The pixel driving control signal (Scan[n]) indicates that the display is in a color cast state.

[0006] 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.

[0007] 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 as described in the first aspect above, and the method includes: Detect current temperature or cumulative display time; The driving and control module provides a driving current to the light-emitting element based on the light-emitting signal (EM[n]), so that the light-emitting element emits light; The driving and regulating module adjusts 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.

[0008] In a fourth aspect, an embodiment of the present application provides an electronic device, comprising a processor and a memory, wherein the memory stores programs or instructions that can be run on the processor, and when the program or instructions are executed by the processor, the steps of the method for improving display color cast as described in the third aspect are implemented.

[0009] In a fifth aspect, an embodiment of the present application provides a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, the steps of the method for improving display color cast as described in the third aspect are implemented.

[0010] In a sixth aspect, an embodiment of the present application provides a chip, comprising a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run a program or instruction to implement the method for improving display color cast as described in the third aspect.

[0011] In a seventh aspect, an embodiment of the present application provides a computer program product, which is stored in a storage medium and is executed by at least one processor to implement the method for improving display color cast as described in the third aspect.

[0012] In an embodiment of the present application, a driving current is provided to a light-emitting element based on a light-emitting signal through a driving and regulating module, and the light-emitting element emits light under the action of the driving current. The driving and regulating module adjusts the driving current based on a pixel driving control signal indicating that the display is in a color cast state, and can adjust the light-emitting brightness of the corresponding pixel of the light-emitting element, thereby improving the problem of display color cast and improving the display effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of a 7T1C LTPS pixel driving circuit in the related art; Figure 2 is a timing diagram of a 7T1C LTPS pixel driving circuit in the related art; Figure 3 It is a schematic diagram of performance comparison of OLED in related art after long-term use; Figure 4 This is a schematic diagram of a circuit structure for improving display color cast provided by an embodiment of the present application; Figure 5This is another schematic diagram of a circuit structure for improving display color cast provided by an embodiment of the present application; Figure 6 This is another schematic diagram of a circuit structure for improving display color cast provided by an embodiment of the present application; Figure 7 This is another schematic diagram of a circuit structure for improving display color cast provided by an embodiment of the present application; Figure 8 This is another schematic diagram of a circuit structure for improving display color cast provided by an embodiment of the present application; Fig. 9 The embodiment of this application provides Figure 8 The driving timing diagram of the circuit shown; Fig.10 is a schematic diagram of a transfer characteristic curve of a P-type transistor provided in an embodiment of the present application; Fig.11 This is another schematic diagram of a circuit structure for improving display color cast provided by an embodiment of the present application; Fig.12 This is another schematic diagram of a circuit structure for improving display color cast provided by an embodiment of the present application; Fig.13 The embodiment of this application provides Fig.12 The driving timing diagram of the circuit shown; Fig.14 This is another schematic diagram of a circuit structure for improving display color cast provided by an embodiment of the present application; Fig.15 This is another schematic diagram of a circuit structure for improving display color cast provided by an embodiment of the present application; Fig.16 Schematic diagram of the GOA generating a pixel driving control signal provided in an embodiment of the present application; Fig.17 This is a schematic flow chart of a method for improving display color cast provided by an embodiment of the present application; Fig.18 It is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0014] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0015] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0016] In order to better understand the technical solution provided by this application, some concepts and / or terms involved in this application are first explained.

[0017] The circuit for improving display color cast provided in the embodiment of the present application is obtained by improving the pixel driving circuit, and can achieve the effect of improving display color cast. Among them, the pixel driving circuit used in the embodiment of the present application can be of various types, including but not limited to: 7T1C LTPS (Low Temperature Polycrystalline Silicon, low temperature polycrystalline silicon), 7T1C LTPO (Low Temperature Polycrystalline Oxide, low temperature polycrystalline oxide), 8T1C LTPS or 8T1C LTPO, etc., without specific limitation.

[0018] The following takes the 7T1C LTPS type as an example to introduce the working principle of the pixel driving circuit. Figure 1 The figure shows the structure diagram of the 7T1C LTPS pixel driving circuit. Figure 1 As shown in the figure, the pixel driving circuit includes 7 TFTs (T1~T7), 1 capacitor Cst and 1 OLED (Organic Light Emitting Diode). Among them, the 7 TFTs can be P-type or N-type. The figure shows that they are all P-type TFTs, which are in the on state when the level is low and in the off state when the level is high. In the one-frame time of display refresh, the driving timing process of the pixel driving circuit can include the following 4 stages, combined with Figure 2 The timing diagram is described in detail.

[0019] (1) Phase t1 (capacitor reset phase): The gate scan signal Scan[n-1] of the n-1th row is at a low level, T4 is turned on, and the first voltage Vint1 (negative voltage) is written to the gate of T1 and stored on the capacitor Cst for retention.

[0020] (2) Phase t2 (data writing and threshold voltage compensation phase): The gate scan signal Scan[n] of the nth row is at a low level, T2 and T3 are turned on, and 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 is finally stored in the capacitor Cst until the voltage on the capacitor Cst becomes Vdata-|Vth|, and T1 is turned off. Among them, Vdata is the input data voltage, and Vth is the threshold voltage of T1 itself. Through this operation, the threshold voltage Vth of T1 is extracted and the voltage of T1 is compensated.

[0021] (3) Phase t3 (OLED reset phase): The gate scan signal Scan[n+1] of the n+1th row is at a low level, T7 is turned on, and the second voltage Vint2 (negative voltage) is written to the anode of the OLED to reset the OLED and release the residual charge accumulated in the OLED.

[0022] (4) Phase t4 (light-emitting phase): The gate scan signals Scan[n-1], Scan[n] and Scan[n+1] are all high level, T2, T3, T4 and T7 are turned off, the nth row light-emitting control gate scan signal EM[n] is low level, T5 and T6 are turned on, at this time, the gate of T1 is in the open state under the action of the storage voltage Vdata-|Vth| of the capacitor Cst, and the current flows from the positive power supply voltage ELVDD through T5, T1, T6, and then flows to the OLED to the negative power supply voltage ELVSS, and the OLED emits light. Among them, ELVDD is a constant positive voltage, usually 4.6V, and ELVSS is an adjustable negative voltage output by the display driver chip to control the power supply chip.

[0023] Figure 3 This is a performance comparison diagram of OLED after long-term use in the related art. In the initial state, the green pixel material in the OLED has the highest luminous efficiency, and the red and blue pixel materials have relatively low luminous efficiency. In order to prevent color cast after the red, green and blue pixels emit light and mix colors, the luminous area of ​​G green light is usually the smallest during pixel design, and the data voltage Vdata of G green light is also the smallest; while the luminous areas of R red light and B blue light are relatively large, and the data voltage Vdata of R red light and B blue light is also relatively large. With this design, the data voltage Vdata matches the luminous area, so that the luminous brightness of G green light, R red light and B blue light also matches, and the mixed color is white light without color cast.

[0024] However, after the screen has been used for a long time, or has worked for a long time in a high temperature and high humidity environment, due to the aging of the TFT device characteristics, under the same data voltage Vdata, the current flowing through the driving transistor T1 increases, resulting in a higher brightness of the OLED light, such as the brightness of the G green light increases from 120nit to 360nit, and the brightness increase is greater than that of the R red light and B blue light. Therefore, the brightness of the red, green and blue pixels does not match, resulting in a color cast on the screen, which is overall green.

[0025] In view of this, the embodiments of the present application provide a circuit, electronic device and method for improving display color cast, which controls the reduction of the current of the light-emitting element through a current control module to overcome the problem of display color cast caused by the increase of current. Among them, the current control module can be implemented by TFT. For example, a T8 is added as a current control module on the basis of the 7T1C LTPS pixel driving circuit, thereby becoming a circuit for improving display color cast of 8T1C LTPS; or, a light-emitting control transistor in the 7T1C LTPS pixel driving circuit is transformed into a current control module, thereby becoming a circuit for improving display color cast of 7T1C LTPS. For another example, a T9 is added as a current control module on the basis of the 8T1C LTPO pixel driving circuit, thereby becoming a circuit for improving display color cast of 9T1C LTPO, etc., and the embodiments of the present invention do not make specific limitations on this. Among them, the light-emitting element includes but is not limited to: OLED or AMOLED, etc., which are not specifically limited.

[0026] The above circuit for improving display color cast can be applied to various electronic devices, including but not limited to: smart terminal devices such as mobile phones, watches or tablets, etc., without specific limitation. Among them, the electronic device may include the above circuit for improving display color cast and a display panel, and the display panel includes but is not limited to: OLED display panel or AMOLED display panel, etc.

[0027] In conjunction with the accompanying drawings, the circuit, electronic device and method for improving display color cast provided by the embodiments of the present application are described in detail through specific embodiments and their application scenarios.

[0028] Figure 4 A circuit for improving display color cast provided by an embodiment of the present application is shown. Figure 4 As shown, the circuit includes: a driving and regulating module 100 and a light emitting element 200.

[0029] The driving and regulating module 100 is used to provide a driving current to the light-emitting element 200 based on the light-emitting signal EM[n], and to 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.

[0030] The light emitting element 200 is connected to the driving and regulating module 100 , and is used for emitting light under the action of the driving current provided by the driving and regulating module 100 .

[0031] The pixel driving control signal Scan[n] indicates that the display is in a color cast state.

[0032] In the embodiment of the present application, the light-emitting signal EM[n] may be generated by a GOA (Gate On Array, gate drive circuit). During a frame time of display refresh, the GOA generates the light-emitting signal EM[n] in the t4 phase (light-emitting phase) to drive the light-emitting element 200 to emit light.

[0033] Among them, the GOA can 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, and the embodiments of the present application do not make specific limitations on this.

[0034] In the embodiment of the present application, the driving process of the circuit for improving display color cast includes: a reset data writing compensation phase and a light emitting phase. Accordingly, the pixel driving control signal Scan[n] may include at least one of the following: 1) A green sub-pixel driving control signal ScanG[n], wherein the voltage of the green sub-pixel driving control signal ScanG[n] in the light-emitting phase is lower than the voltage in the reset data writing compensation phase.

[0035] In this scenario, the green sub-pixel produces a color cast, that is, the color after mixing is green. The green sub-pixel drive control signal ScanG[n] can be used to reduce the drive current during the light-emitting stage, thereby reducing the light-emitting brightness of the green pixel of the light-emitting element 200, thereby improving the green display situation.

[0036] 2) Red sub-pixel driving control signal ScanR[n], wherein the voltage of the red sub-pixel driving control signal ScanR[n] in the light-emitting phase is lower than the voltage in the reset data writing compensation phase.

[0037] In this scenario, the red sub-pixel produces a color cast, that is, the color after mixing is reddish. The red sub-pixel drive control signal ScanR[n] is used to reduce the drive current during the light-emitting stage, thereby reducing the light-emitting brightness of the red pixel of the light-emitting element 200, which can improve the reddish display situation.

[0038] 3) A blue sub-pixel driving control signal ScanB[n], wherein the voltage of the blue sub-pixel driving control signal ScanB[n] in the light emitting phase is lower than the voltage in the reset data writing compensation phase.

[0039] In this scenario, the blue sub-pixel produces a color cast, that is, the color after mixing is blue, and the blue sub-pixel drive control signal ScanB[n] is used to reduce the drive current during the light-emitting stage, thereby reducing the light-emitting brightness of the blue pixel of the light-emitting element 200, which can improve the blue display situation.

[0040] The above three scenarios can be applied in combination. The green sub-pixel drive control signal ScanG[n], the red sub-pixel drive control signal ScanR[n] and the blue sub-pixel drive control signal ScanB[n] can be used one, two or three at the same time to overcome the problem of display color cast.

[0041] For example, if the display is both green and red, the green sub-pixel drive control signal ScanG[n] and the red sub-pixel drive control signal ScanR[n] are used simultaneously to reduce the drive current, thereby reducing the light emitting brightness of the green and red pixels of the light emitting element 200.

[0042] For another example, if the display is both green and blue, the green sub-pixel drive control signal ScanG[n] and the blue sub-pixel drive control signal ScanB[n] are used simultaneously to reduce the drive current, thereby reducing the light emitting brightness of the green and blue pixels of the light emitting element 200.

[0043] For another example, if the display is green, red and blue at the same time, the green sub-pixel drive control signal ScanG[n], the red sub-pixel drive control signal ScanR[n] and the blue sub-pixel drive control signal ScanB[n] are used simultaneously to reduce the drive current, thereby reducing the luminous brightness of the green, red and blue pixels of the light-emitting element 200.

[0044] In the embodiment of the present application, the degree of color cast of the three sub-pixels of red, green and blue may be different. If the color cast of the first sub-pixel is higher than that of the second sub-pixel, then in the light-emitting stage, the voltage reduction amplitude of the first sub-pixel driving control signal is higher than the voltage reduction amplitude of the second sub-pixel driving control signal, so that the light-emitting brightness of the two sub-pixels can be matched. Among them, the first sub-pixel can be any one of the green, red and blue sub-pixels, and the second sub-pixel can be any one of the green, red and blue sub-pixels, and the two are sub-pixels of different colors.

[0045] For example, if the display is both green and red, but the degree of color deviation of the green sub-pixel is higher, that is, the overall color is more green, the green sub-pixel drive control signal ScanG[n] and the red sub-pixel drive control signal ScanR[n] can be used simultaneously to reduce the drive current. From the reset data writing compensation stage to the light-emitting stage In the light-emitting stage, the voltage of the green sub-pixel drive control signal is reduced from a low level of -10V to -5V, and the voltage of the red sub-pixel drive control signal is reduced from a low level of -10V to -8V, thereby reducing the luminous brightness of the green and red sub-pixels of the light-emitting element 200, and reducing the luminous brightness of the green sub-pixel more, so that the luminous brightness of the green and red sub-pixels matches.

[0046] See also Figure 5 and Figure 6 In the embodiment of the present application, the driving and regulating module 100 may include: a light emitting control and driving unit 10 and a current regulating unit 20 .

[0047] The light-emitting control and driving unit 10 and the current control unit 20 are connected in series, one end of the light-emitting control and driving unit 10 is connected to the light-emitting signal EM[n], and one end of the current control unit 20 is connected to the pixel driving control signal Scan[n].

[0048] The light control and driving unit 10 is used to provide a driving current to the light emitting element 200 based on the light emitting signal EM[n]. The current control unit 20 is used to 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.

[0049] Among them, Figure 5 As shown, one end of the current control unit 20 is connected to the light emitting element 200. Alternatively, Figure 6 As shown, one end of the light emitting control and driving unit 10 is connected to the light emitting element 200 .

[0050] See also Figure 5 One end of the current control unit 20 is connected to the light-emitting element 200 . The above circuit provided in the embodiment of the present application may further include: a light-emitting element reset module 300 .

[0051] 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 emitting control and driving unit 10 and the current control unit 20. The light emitting element reset module 300 is used to reset the light emitting element 200 based on the second voltage Vint2.

[0052] See also Figure 6 One end of the light emitting control and driving unit 10 is connected to the light emitting element 200 . The above circuit provided in the embodiment of the present application may further include: a light emitting element reset module 300 .

[0053] 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 emitting control and driving unit 10 and the light emitting element 200. The light emitting element reset module 300 is used to reset the light emitting element 200 based on the second voltage Vint2.

[0054] The above-mentioned circuit provided in the embodiment of the present application provides a driving current to the light-emitting element based on the light-emitting signal through the driving and regulating module. The light-emitting element emits light under the action of the driving current. The driving and regulating module adjusts the driving current based on the pixel driving control signal indicating that the display is in a color cast state, and can adjust the light-emitting brightness of the corresponding pixel of the light-emitting element, thereby improving the problem of display color cast and improving the display effect.

[0055] Figure 7 Another circuit for improving display color cast provided by an embodiment of the present application is shown, and an example of adding a first current control unit in a pixel driving circuit is used for explanation. Figure 7 As shown, the circuit includes: a driving and regulating 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.

[0056] 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 a first level.

[0057] In the embodiment of the present application, the first level can be a high level or a low level, which is determined by the type of TFT used by the first light-emitting control unit 11. For example, if the first light-emitting control unit 11 uses a P-type TFT, the first level is a low level, that is, it is in an open state in the case of a low level, and it is in a closed state in the case of a high level. For another example, if the first light-emitting control unit 11 uses an N-type TFT, the first level is a high level, that is, it is in an open state in the case of a high level, and it is in a closed state in the case of a low level.

[0058] The driving unit 12 is in an on state when the data voltage is greater than a threshold voltage of the driving unit 12 .

[0059] The first current control unit 21 is always in an open state during the driving process of the above circuit, with one end connected to the pixel driving control signal Scan[n] and the other end connected to the light emitting element 200 .

[0060] When the first light emitting control unit 11 , the driving unit 12 , the second light emitting control unit 13 and the first current regulating unit 21 are all in an on state, a driving current is provided to the light emitting element 200 .

[0061] The first current control unit 21 is used to adjust (eg, reduce) the driving current based on the pixel driving control signal Scan[n], so as to adjust (eg, reduce) the light emitting brightness of the corresponding pixel of the light emitting element 200 .

[0062] In the 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 used to reset the light emitting element 200 based on the second voltage Vint2 when the first current control unit 21 is in the on state. The first node D1 is a connection node between the second light emitting control unit 13 and the first current control unit 21.

[0063] Combine the following Figure 7 and Figure 8 Detailed description Figure 5 The specific application scenario of the circuit shown is described by taking the addition of a first current control unit in a 7T1C LTPS pixel driving circuit as an example. Figure 7 Demonstrates the functions of each module. Figure 8 The connection relationship between each device is shown. Figure 8 As shown, T5 and T6 are respectively the first light-emitting control unit and the second light-emitting control unit, and both are connected to the light-emitting 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: red sub-pixel drive control signal ScanR[n], green sub-pixel drive control signal ScanG[n] and blue sub-pixel drive control signal ScanB[n]. The source of T8 is connected to T6, i.e., the second light-emitting 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 is connected to the second voltage Vint2, and the drain is connected to the connection node between T6 and T8. In the case of display color cast due to the increase of the current flowing through the driving unit T1, the pixel drive control signal Scan[n] is generated to reduce the drive current, thereby reducing the light-emitting brightness of the corresponding sub-pixel of the light-emitting element OLED.

[0064] Fig. 9 Shows Figure 8 The driving timing diagram of the circuit shown in FIG. Figure 8 The devices in the figure are all P-type TFTs. If N-type TFTs are used, the driving timing diagram is the same as Fig. 9 The waveform is opposite to that of Fig. 9As shown, within one frame time of display refresh, the entire driving timing process can be divided into the following four stages.

[0065] (1) Phase t1 (capacitor reset phase): The gate scan signal Scan[n-1] of the n-1th row is at a low level, the data reset module T4 is turned on, and the first voltage Vint1 (negative voltage) is written to the gate of the driving unit T1 and stored on the capacitor Cst for retention.

[0066] (2) Phase t2 (data writing and threshold voltage compensation phase): The nth 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, and the driving unit 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 is finally stored in the capacitor Cst until the voltage on the capacitor Cst becomes Vdata-|Vth|, and T1 is turned off. Among them, Vdata is the input data voltage, and Vth is the threshold voltage of T1 itself. Through this operation, the threshold voltage Vth of T1 is extracted and the voltage of T1 is compensated.

[0067] (3) Phase t3 (OLED reset phase): The gate scan signal Scan[n+1] of the n+1th row is at a low level, T7 is turned on, and the second voltage Vint2 (negative voltage) is written to the anode of the OLED to reset the OLED and release the residual charge accumulated in the OLED.

[0068] During the above-mentioned phases t1 to t3 , the pixel driving control signals ScanR[n], ScanG[n], and ScanB[n] all output a low level voltage of −10V, and the first current control unit T8 is in an open state.

[0069] (4) Phase t4 (light-emitting phase): The gate scanning signals Scan[n-1], Scan[n], and Scan[n+1] are all high, and T2, T3, T4, and T7 are all closed. The nth row light-emitting control gate scanning signal EM[n] is low, and T5 and T6 are turned on. At this time, the gate of T1 is in the open state under the action of the storage voltage Vdata-|Vth| of the capacitor Cst, and the pixel drive control signals ScanR[n], ScanG[n], and ScanB[n] all output low levels. T8 is also in the open state. The current flows from the positive power supply voltage ELVDD through T5, T1, T6, and T8, and then flows to the OLED to the negative power supply voltage ELVSS, and the OLED emits light. Among them, ScanG[n], ScanR[n], and ScanB[n] output -5V, -8V, and -7V respectively, which regulate and reduce the current flowing through the three OLEDs G, R, and B, so that the luminous brightness of the G, R, and B sub-pixels matches, thereby improving the display color cast problem. Among them, the green sub-pixel has the largest voltage drop and the luminous brightness also drops the most, which can improve the overall green cast problem.

[0070] Fig.10 FIG. 1 shows a schematic diagram of the transfer characteristic curve of a P-type transistor. Fig.10 As shown, when the first current control unit adopts a P-type TFT, when the pixel drive control signal Scan[n] connected to the gate is at a low level, it is in an open state (the area where the voltage is negative in the figure), and when the pixel drive control signal Scan[n] is at a high level, it is in a closed state (the area where the voltage is positive in the figure). In the t1~t3 stage, the pixel drive control signal Scan[n] outputs a -10V voltage. In the t4 stage, the pixel drive control signals ScanR[n], ScanB[n], and ScanG[n] output -8V, -7V, and -5V voltages, respectively. It can be seen that when the voltage drops, the source-drain current also decreases accordingly, thereby reducing the luminous brightness of each color sub-pixel of the OLED.

[0071] Fig.11 Another circuit for improving display color cast provided by an embodiment of the present application is shown, and an example of transforming the original second light emitting control unit into a second current regulating unit is used for explanation. Fig.11 As shown, the circuit includes: a driving and regulating 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.

[0072] 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.

[0073] In the embodiment of the present application, the first level may be a high level or a low level, which is determined by the type of TFT used by the first light emitting control unit 11. For example, if the first light emitting control unit 11 uses a P-type TFT, the first level is a low level, that is, it is in an open state in the case of a low level, and is in an off state in the case of a high level.

[0074] The driving unit 12 is in an on state when the data voltage is greater than a threshold voltage of the driving unit 12 .

[0075] Among them, one end of the second current control unit 22 is connected to the pixel drive control signal Scan[n], and the other end is connected to the light-emitting element 200. When the pixel drive control signal Scan[n] is at the first level, it is in an open state, and when the pixel drive control signal Scan[n] is at the second level, it is in a closed state.

[0076] In the embodiment of the present application, the first level can be a high level or a low level, which is determined by the type of TFT used by the second current control unit 22. For example, if the second current control unit 22 uses a P-type TFT, the first level is a low level, that is, it is in an open state in the case of a low level, and it is in a closed state in the case of a high level. For another example, if the second current control unit 22 uses an N-type TFT, the first level is a high level, that is, it is in an open state in the case of a high level, and it is in a closed state in the case of a low level.

[0077] When the first light emitting control unit 11 , the driving unit 12 and the second current regulating unit 22 are all in an on state, a driving current is provided to the light emitting element 200 .

[0078] The second current control unit 22 is used to adjust (eg, reduce) the driving current based on the pixel driving control signal Scan[n] in the turned-on state, so as to adjust (eg, reduce) the light emitting brightness of the corresponding pixel of the light emitting element 200 .

[0079] In the 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 second node D2, and is used to reset the light emitting element 200 based on the second voltage Vint2 when the second current regulating unit 232 is in the off state. The second node D2 is a connection node between the second current regulating unit 22 and the light emitting element 200.

[0080] Combine the following Fig.11 and Fig.12 Detailed description Figure 6The specific application scenario of the circuit shown is described by taking the transformation of the original light emitting control unit in the 7T1C LTPS pixel driving circuit into the second current control unit as an example. Fig.11 Demonstrates the functions of each module. Fig.12 The connection relationship between each device is shown. Fig.12 As shown, T5 is the first light-emitting control unit, connected to the light-emitting signal EM[n]. T1 is the driving unit. The modified T6 is the second current regulation unit. The gate of T6 is connected to the pixel drive control signal Scan[n], including: red sub-pixel drive control signal ScanR[n], green sub-pixel drive control signal ScanG[n] and blue sub-pixel 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 is connected to the second voltage Vint2, and the drain is connected to the connection node between T6 and OLED. In the case of display color cast due to the increase of current flowing through the driving unit T1, the pixel drive control signal Scan[n] is generated to reduce the drive current, thereby reducing the luminous brightness of the corresponding sub-pixel of the light-emitting element OLED.

[0081] Fig.13 Shows Fig.12 The driving timing diagram of the circuit shown in FIG. Fig.12 The devices in the figure are all P-type TFTs. If N-type TFTs are used, the driving timing diagram is the same as Fig.13 The waveform is opposite to that of Fig.13 As shown, within one frame time of display refresh, the entire driving timing process can be divided into the following four stages.

[0082] (1) Phase t1 (capacitor reset phase): The gate scan signal Scan[n-1] of the n-1th row is at a low level, the data reset module T4 is turned on, and the first voltage Vint1 (negative voltage) is written to the gate of the driving unit T1 and stored on the capacitor Cst for retention.

[0083] (2) Phase t2 (data writing and threshold voltage compensation phase): The nth 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, and the driving unit 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 is finally stored in the capacitor Cst until the voltage on the capacitor Cst becomes Vdata-|Vth|, and T1 is turned off. Among them, Vdata is the input data voltage, and Vth is the threshold voltage of T1 itself. Through this operation, the threshold voltage Vth of T1 is extracted and the voltage of T1 is compensated.

[0084] (3) Phase t3 (OLED reset phase): The gate scan signal Scan[n+1] of the n+1th row is at a low level, T7 is turned on, and the second voltage Vint2 (negative voltage) is written to the anode of the OLED to reset the OLED and release the residual charge accumulated in the OLED.

[0085] During the above-mentioned phases t1 to t3 , the pixel driving control signals ScanR[n], ScanG[n], and ScanB[n] all output a high-level voltage of 10V, and the second current control unit T6 is in a closed state.

[0086] (4) t4 stage (light-emitting stage): The gate scanning signals Scan[n-1], Scan[n], and Scan[n+1] are all high, and T2, T3, T4, and T7 are all closed. The nth row light-emitting control gate scanning signal EM[n] is low, and T5 and T6 are turned on. At this time, the gate of T1 is in the open state under the action of the storage voltage Vdata-|Vth| of the capacitor Cst, and the pixel drive control signals ScanR[n], ScanG[n], and ScanB[n] all output low levels. T6 is also in the open state. The current flows from the positive power supply voltage ELVDD through T5, T1, and T6, and then flows to the OLED to the negative power supply voltage ELVSS, and the OLED emits light. Among them, ScanG[n], ScanR[n], and ScanB[n] output -5V, -8V, and -7V respectively, which regulate and reduce the current flowing through the three OLEDs G, R, and B, so that the luminous brightness of the G, R, and B sub-pixels matches, thereby improving the display color cast problem. Among them, the green sub-pixel has the largest voltage drop and the luminous brightness also drops the most, which can improve the overall green cast problem. The curve diagram of the voltage reduction and driving current change of each sub-pixel can be referred to Fig. 9 , no further explanation will be given here.

[0087] Fig.14 Another circuit for improving display color cast provided by an embodiment of the present application is shown, and an example of transforming the original first light control unit into a third current control unit is used for explanation. Fig.14 As shown, the circuit includes: a driving and regulating 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.

[0088] Among them, one end of the third current control unit 23 is connected to the pixel driving control signal Scan[n], and is in an open state when the pixel driving control signal Scan[n] is at a first level, and is in a closed state when the pixel driving control signal Scan[n] is at a second level.

[0089] In the embodiment of the present application, the first level can be a high level or a low level, which is determined by the type of TFT used by the third current control unit 23. For example, if the third current control unit 23 uses a P-type TFT, the first level is a low level, that is, it is in an open state in the case of a low level, and it is in a closed state in the case of a high level. For another example, if the third current control unit 23 uses an N-type TFT, the first level is a high level, that is, it is in an open state in the case of a high level, and it is in a closed state in the case of a low level.

[0090] The driving unit 12 is in an on state when the data voltage is greater than a threshold voltage of the driving unit 12 .

[0091] One end of the second light emitting control unit 13 is connected to the light emitting signal EM[n], and the other end is connected to the light emitting element 200 , and is in an on state when the light emitting signal EM[n] is at the first level.

[0092] In the embodiment of the present application, the first level may be a high level or a low level, which is determined by the type of TFT used by the second light emitting control unit 13. For example, if the second light emitting control unit 13 uses a P-type TFT, the first level is a low level, that is, it is in an open state in the case of a low level, and is in an off state in the case of a high level.

[0093] When the third current control unit 23 , the driving unit 12 and the second light emitting control unit 13 are all in the turned-on state, the driving current is provided to the light emitting element 200 .

[0094] The third current regulating unit 23 is used to adjust (eg, reduce) the driving current based on the pixel driving control signal Scan[n] in the turned-on state, so as to adjust (eg, reduce) the light emitting brightness of the corresponding pixel of the light emitting element 200 .

[0095] In the 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 third node D3, and is used to reset the light-emitting element 200 based on the second voltage Vint2 when the third current control unit 23 is in the off state, wherein the third node D3 is a connection node between the second light-emitting control unit 13 and the light-emitting element 200.

[0096] Combine the following Fig.14 and Fig.15 Detailed description Figure 6 The specific application scenario of the circuit shown is described by taking the transformation of the original light emitting control unit in the 7T1C LTPS pixel driving circuit into the third current control unit as an example. Fig.14 Demonstrates the functions of each module. Fig.15The connection relationship between each device is shown. Fig.15 As shown, T6 is the second light-emitting control unit, connected to the light-emitting signal EM[n]. T1 is the driving unit. The modified T5 is the third current regulation unit. The gate of T5 is connected to the pixel drive control signal Scan[n], including: red sub-pixel drive control signal ScanR[n], green sub-pixel drive control signal ScanG[n] and blue sub-pixel 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 is connected to the second voltage Vint2, and the drain is connected to the connection node between T6 and OLED. In the case of display color cast due to the increase of current flowing through the driving unit T1, a pixel drive control signal Scan[n] is generated to reduce the drive current, thereby reducing the luminous brightness of the corresponding sub-pixel of the light-emitting element OLED. The driving timing diagram of the above circuit can be referred to. Fig.13 In one frame of display refresh, the entire drive timing includes 4 stages. Fig.13 The corresponding instructions will not be repeated here.

[0097] In the embodiment of the present application, the pixel drive control signal Scan[n] involved in any of the above embodiments can be generated by GOA. The gate drive circuit can be located on the left side of the screen, or on the right side of the screen, or on the left and right sides of the screen respectively, without specific limitation. Located on the left side and located on the right side are both single-drive scenarios, and located on the left and right sides at the same time, it belongs to a dual-drive scenario, and the embodiment of the present application does not make specific limitations on this.

[0098] Fig.16 FIG. 2 shows a schematic diagram of a GOA generating a pixel driving control signal provided by an embodiment of the present application. Fig.16 As shown in the figure, the pixel drive control signals ScanR[n], ScanG[n], and ScanB[n] are generated by the gate drive circuit placed in the black GOA area on the right frame of the screen, and are respectively connected to the R, G, and B sub-pixel drive circuits in a row of pixels in the AA (Active Area, the actual display pixel luminous area). The figure shows a single-drive scenario, where the GOA area is arranged only on one side of the screen. Among them, 1 push 1 means that 1 GOA circuit module drives 1 row of pixels.

[0099] An embodiment of the present application also provides an electronic device, which may include: a display panel and a circuit for improving display color cast as described in any of the above embodiments. The function of the circuit is the same as that described in the above embodiments and can achieve the same technical effect, which will not be repeated here.

[0100] See also Fig.17 , is a schematic flow chart of a method for improving display color cast provided by an embodiment of the present application. Fig.17 As shown, the method is applied to the circuit for improving display color cast as described in any of the above embodiments, and the method specifically includes the following steps.

[0101] S1702: Providing a driving current to the light-emitting element based on the light-emitting signal EM[n], so that the light-emitting element emits light.

[0102] S1704: 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.

[0103] In the embodiment of the present application, the above step S1704 may specifically include: The driving current is reduced based on the pixel driving control signal Scan[n] to reduce the light emitting brightness of the corresponding pixel of the light emitting element.

[0104] The pixel driving control signal (Scan[n]) indicates that the display is in a color cast state.

[0105] In the embodiment of the present application, before the above step S1702, the above method may further include: When the display is in a color cast state, the pixel driving control signal is obtained.

[0106] In one implementation, the pixel driving control signal (Scan[n]) indicates that the current temperature is greater than a first threshold or the accumulated display time is greater than a second threshold.

[0107] In the embodiment of the present application, the pixel driving control signal (Scan[n]) can be generated by the following steps: The current temperature or the accumulated display time is detected, and when the current temperature is greater than a first threshold or the accumulated display time is greater than a second threshold, a pixel driving control signal Scan[n] is generated.

[0108] The first threshold and the second threshold can be set as needed, and the specific values ​​are not limited. For example, the first threshold is 50 degrees, and the second threshold is 1 year.

[0109] The pixel drive control signal Scan[n] includes at least one of the following: a red sub-pixel drive control signal ScanR[n], a green sub-pixel drive control signal ScanG[n], and a blue sub-pixel drive control signal ScanB[n]. The voltage of any sub-pixel drive control signal in the light-emitting stage is lower than the voltage of any sub-pixel drive control signal in the reset data writing compensation stage. In practical applications, if a color produces color cast, a corresponding color sub-pixel drive control signal is generated to overcome the color cast problem.

[0110] Among them, 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 the voltage range of -10V~10V according to the current temperature or the accumulated display time.

[0111] The above method provided in the embodiment of the present application provides a driving current to the light-emitting element based on the light-emitting signal EM[n] to make the light-emitting element emit light, and adjusts the driving current based on the pixel driving control signal Scan[n] that indicates that the display is in a color cast state to adjust the light-emitting brightness of the corresponding pixel of the light-emitting element, thereby improving the problem of display color cast and improving the display effect.

[0112] See also Fig.18 , is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. Fig.18 As shown, an embodiment of the present application further provides an electronic device 1800, including a processor 1801 and a memory 1802, wherein the memory 1802 stores a program or instruction that can be executed on the processor 1801, and when the program or instruction is executed by the processor 1801, each step of the above-mentioned method embodiment for improving display color cast is implemented, and the same technical effect can be achieved. To avoid repetition, it will not be described here.

[0113] It should be noted that the electronic devices in the embodiments of the present application include mobile electronic devices and non-mobile electronic devices.

[0114] An embodiment of the present application also provides a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, each process of the above-mentioned method embodiment for improving display color cast is implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0115] The processor is the processor in the electronic device described in the above embodiment. The readable storage medium includes a computer readable storage medium, such as a computer read-only memory ROM, a random access memory RAM, a magnetic disk or an optical disk.

[0116] An embodiment of the present application further provides a chip, which includes a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the various processes of the above-mentioned method embodiment for improving display color cast, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0117] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0118] An embodiment of the present application provides a computer program product, which is stored in a storage medium. The program product is executed by at least one processor to implement the various processes of the above-mentioned method embodiment for improving display color cast, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0119] It should be noted that, in this article, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0120] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a computer software product, which is stored in a storage medium (such as ROM / RAM, a magnetic disk, or an optical disk), and includes a number of instructions for enabling a terminal (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present application.

[0121] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A circuit for improving display color cast, characterized in that: include: A driving and regulating module, configured to provide a driving current to the light-emitting element based on a light-emitting signal (EM[n]), and to adjust the driving current based on a pixel driving control signal (Scan[n]) so as to adjust the light-emitting brightness of a corresponding pixel of the light-emitting element; A light-emitting element, connected to the driving and regulating module, and configured to emit light under the action of a driving current provided by the driving and regulating module; The pixel driving control signal (Scan[n]) indicates that the display is in a color cast state.

2. The circuit according to claim 1, characterized in that The driving process of the circuit includes a reset data writing compensation phase and a light emitting phase, and the pixel driving control signal (Scan[n]) includes at least one of the following: A green sub-pixel driving control signal (ScanG[n]), a red sub-pixel driving control signal (ScanR[n]), and a blue sub-pixel driving control signal (ScanB[n]), wherein a voltage of any sub-pixel driving control signal in the light-emitting stage is lower than a voltage of any sub-pixel driving control signal in the reset data writing compensation stage.

3. The circuit according to claim 1, characterized in that The driving and regulating module comprises: a light emitting control and driving unit and a current regulating unit; The light-emitting control and driving unit and the current control unit are connected in series, one end of the light-emitting control and driving unit is connected to the light-emitting signal (EM[n]), and one end of the current control unit is connected to the pixel driving control signal (Scan[n]); The light emitting control and driving unit is used to provide a driving current to the light emitting element based on the light emitting signal (EM[n]); The current control unit is used to 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; One end of the current regulating unit is connected to the light emitting element, or one end of the light emitting control and driving unit is connected to the light emitting element.

4. The circuit according to claim 3, characterized in that One end of the current control unit is connected to the light emitting element, and the circuit further includes: A light emitting element reset module, one end of the light emitting element reset module is connected to a second voltage (Vint2), and the other end of the light emitting element reset module is connected to a first node (D1), wherein the first node (D1) is a connection node between the light emitting control and driving unit and the current regulating unit; The light emitting element resetting module is used for resetting the light emitting element based on the second voltage (Vint2).

5. The circuit according to claim 3, characterized in that One end of the light emitting control and driving unit is connected to the light emitting element, and the circuit further includes: A light emitting element reset module, one end of which is connected to a second voltage (Vint2), and the other end of which is connected to a second node (D2), wherein the second node (D2) is a connection node between the light emitting control and driving unit and the light emitting element; The light emitting element resetting module is used for resetting the light emitting element based on the second voltage (Vint2).

6. The circuit according to any one of claims 1 to 5, characterized in that: The pixel driving control signal (Scan[n]) is generated by a gate driving circuit, and the gate driving circuit is located on the left side of the screen, or on the right side of the screen, or on both the left side and the right side of the screen.

7. An electronic device, characterized in that: include: A display panel and a circuit for improving display color cast as claimed in any one of claims 1 to 6.

8. A method for improving display color cast, characterized in that: The circuit for improving display color cast as claimed in any one of claims 1 to 6, wherein the method comprises: Providing a driving current to the light-emitting element based on the light-emitting signal (EM[n]) so that the light-emitting element emits light; Adjusting 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; The pixel driving control signal (Scan[n]) indicates that the display is in a color cast state.

9. The method according to claim 8, characterized in that The pixel driving control signal (Scan[n]) indicates that the current temperature is greater than a first threshold or the accumulated display time is greater than a second threshold.

10. The method according to claim 8 or 9, characterized in that: Before providing the driving current to the light emitting element based on the light emitting signal, the method further includes: When the display is in a color cast state, the pixel driving control signal is obtained.

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