Circuit for improving display smear color cast and electronic equipment

Abstract

The invention discloses a circuit for improving display smear color cast and electronic equipment, and belongs to the technical field of display. The circuit comprises a light-emitting control and driving module, a resistance value regulation and control module and a light-emitting element, the light-emitting control and driving module is connected with the light-emitting element through the resistance regulation and control module and is used for providing driving current for the light-emitting element based on the light-emitting signal; the light-emitting element comprises a red sub-pixel, a green sub-pixel and a blue sub-pixel, the red sub-pixel is connected with the resistance value regulation and control module to form a first light-emitting branch, the green sub-pixel is connected with the resistance value regulation and control module to form a second light-emitting branch, and the blue sub-pixel is connected with the resistance value regulation and control module to form a third light-emitting branch; the light-emitting element is used for emitting light under the action of the driving current; the resistance value regulation and control module is used for regulating the resistance value of at least one light-emitting branch circuit under the condition that the brightness is switched, so that the light-emitting response time of each sub-pixel of the light-emitting element is matched, and the light-emitting branch circuit comprises a first light-emitting branch circuit, a second light-emitting branch circuit and a third light-emitting branch circuit.

Description

Technical Field

[0001] This application belongs to the field of display technology, and particularly relates to a circuit and an electronic device for improving display smear and color cast. Background Art

[0002] AMOLED (Active Matrix Organic Light Emitting Diode) display technology has the characteristics of high contrast ratio, fast response speed, wide viewing angle, and wide color gamut, and has been widely used in smartphones and smart watches at present. The pixel driving circuit of AMOLED usually consists of multiple TFTs (Thin Film Transistor), such as the 8T1C LTPO (Low Temperature Polycrystalline Oxide) AMOLED pixel driving circuit consists of 6 P-type TFTs and 2 N-type TFTs.

[0003] During the light-emitting stage of AMOLED, the driving current first charges the parasitic capacitance of AMOLED itself. After the parasitic capacitance is fully charged, AMOLED can emit light. Since the capacitance characteristics and turn-on characteristics of the R (red), G (green), and B (blue) sub-pixel light-emitting materials of AMOLED are not exactly the same, when the display interface switches from a low gray level with a low brightness to a high gray level with a high brightness, at the moment of dragging and turning on, the parasitic capacitance of the G sub-pixel is the largest and the charging time is the longest, resulting in the slowest light-emitting response time, while the parasitic capacitances of the R sub-pixel and the B sub-pixel are smaller and the charging times are shorter, resulting in faster light-emitting response times. Therefore, the color generated after the RGB sub-pixels emit light and mix colors will have smear and color cast, showing phenomena such as red bias or purple bias. Summary of the Invention The purpose of the embodiments of this application is to provide a circuit and an electronic device for improving display smear and color cast, which can solve the problem of display smear and color cast in related technologies.

[0004] In a first aspect, the embodiments of this application provide a circuit for improving display smear and color cast, including: A light-emitting control and driving module, a resistance value regulation module, and a light-emitting element; The light-emitting control and driving module is connected to the light-emitting element through the resistance value regulation module, and the light-emitting control and driving module is used to provide a driving current to the light-emitting element based on a light-emitting signal; The light-emitting element includes a red sub-pixel, a green sub-pixel, and a blue sub-pixel. The red sub-pixel is connected to the resistance value regulation module to form a first light-emitting branch, the green sub-pixel is connected to the resistance value regulation module to form a second light-emitting branch, and the blue sub-pixel is connected to the resistance value regulation module to form a third light-emitting branch. The light-emitting element is used to emit light under the action of the drive current provided by the light-emitting control and drive module. The resistance value regulation module is used to adjust the resistance value of at least one light-emitting branch when the brightness is switched, so that the light-emitting response times of the sub-pixels of the light-emitting element match, where the light-emitting branches include the first light-emitting branch, the second light-emitting branch, and the third light-emitting branch.

[0005] In a second aspect, an embodiment of the present application provides an electronic device, including: a display panel and the circuit for improving display ghosting and color deviation as described in the first aspect above.

[0006] In the embodiment of the present application, the light-emitting control and drive module provides a drive current to the light-emitting element based on a light-emitting signal. The light-emitting element includes a red sub-pixel, a green sub-pixel, and a blue sub-pixel, which are respectively connected to the resistance value regulation module to form a first light-emitting branch, a second light-emitting branch, and a third light-emitting branch. The light-emitting element emits light under the action of the drive current. The resistance value regulation module adjusts the resistance value of at least one light-emitting branch when the brightness is switched, so that the light-emitting response times of the sub-pixels of the light-emitting element match, which can improve the problem of color ghosting and color deviation generated after the light emission of the red, green, and blue sub-pixels is mixed, avoid the phenomenon of being reddish or purplish, and improve the display effect. Description of the Drawings

[0007] Figure 1 is a schematic structural diagram of a circuit for improving display ghosting and color deviation provided by an embodiment of the present application; Figure 2 is a schematic diagram of the capacitance characteristics of the sub-pixel light-emitting material provided by an embodiment of the present application; Figure 3 is a schematic diagram of the turn-on characteristics of the sub-pixel light-emitting material provided by an embodiment of the present application; Figure 4 is a schematic structural diagram of an 8T1C LTPO circuit provided by an embodiment of the present application; Figure 5 is provided by an embodiment of the present application Figure 4 The drive timing diagram of the shown circuit; Figure 6 is a schematic structural diagram of an electronic device provided by an embodiment of the present application. Detailed Embodiments

[0008] Next, the technical solutions in the embodiments of the present application will be clearly described in conjunction with the accompanying drawings 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. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present application.

[0009] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are usually of the same category, and the number of objects is not limited. For example, the first object can be one or multiple. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally indicates an "or" relationship between the associated objects before and after.

[0010] The circuit for improving display ghosting and color cast provided by the embodiments of the present application is obtained by improving the pixel driving circuit and can achieve the effect of improving display ghosting and color cast. Among them, the pixel driving circuit used in the embodiments of the present application can have various types, including but not limited to: 7T1C LTPS (Low Temperature Polycrystalline Silicon), 7T1C LTPO (Low Temperature Polycrystalline Oxide), 8T1C LTPS or 8T1C LTPO, etc., without specific limitation. Among them, the light-emitting elements in the above pixel driving circuit include but not limited to: OLED (Organic Light Emitting Diode) or AMOLED, etc., without specific limitation. The circuit for improving display ghosting and color cast in the embodiments of the present application can be obtained by adding a resistance value regulation module to the pixel driving circuit. Among them, through the resistance value regulation module, the light-emitting response time of each sub-pixel of the light-emitting element can be adjusted, so as to improve the problem of color ghosting and color cast generated after the light emission of the red, green, and blue sub-pixels is mixed, avoid the phenomenon of being too red or too purple, and improve the display effect.

[0011] The above circuit for improving display ghosting and color cast can be applied to various electronic devices, including but not limited to: intelligent terminal devices such as mobile phones, watches or tablets, without specific limitation. Among them, the electronic device can include the above circuit for improving display ghosting and color cast and a display panel, and the display panel includes but not limited to: OLED display panel or AMOLED display panel, etc., without specific limitation.

[0012] The following will combine the accompanying drawings and, through specific embodiments and their application scenarios, elaborate in detail on the circuit and electronic device for improving display ghosting and color cast provided by the embodiments of the present application.

[0013] Figure 1 Fig. shows a circuit for improving display ghosting and color cast provided by the embodiments of the present application. As Figure 1 shown, the circuit includes: a light emission control and driving module 100, a resistance value regulation module 200, and a light emitting element 300.

[0014] The light emission control and driving module 100 is connected to the light emitting element 300 through the resistance value regulation module 200. The light emission control and driving module 100 is used to provide a driving current to the light emitting element 300 based on the light emission signal EM.

[0015] The light emitting element 300 includes a red sub-pixel, a green sub-pixel, and a blue sub-pixel. The red sub-pixel is connected to the resistance value regulation module 200 to form a first light emission branch, the green sub-pixel is connected to the resistance value regulation module 200 to form a second light emission branch, and the blue sub-pixel is connected to the resistance value regulation module 200 to form a third light emission branch. The light emitting element 300 is used to emit light under the action of the driving current provided by the light emission control and driving module 100.

[0016] The resistance value regulation module 200 is used to adjust the resistance value of at least one light emission branch when the brightness is switched, so that the light emission response times of the sub-pixels of the light emitting element match. Among them, the above light emission branches include a first light emission branch, a second light emission branch, and a third light emission branch.

[0017] In the embodiments of the present application, the light emission signal EM can be generated by GOA (Gate On Array). During one frame time of display refreshing, GOA generates the light emission signal EM and inputs it to the light emission control and driving module 100 to generate a driving current, and then drives the light emitting element 300 to emit light.

[0018] The brightness switching in the embodiments of the present application may include: switching from a low gray scale of a lower brightness to a high gray scale of a higher brightness, or switching from a high gray scale of a higher brightness to a low gray scale of a lower brightness, which is not specifically limited.

[0019] In the embodiments of the present application, the resistance value regulation module 200 can be used to perform at least one of the following: 1) When the brightness is switched, reduce the resistance value of the second light emission branch to shorten the light emission response time of the green sub-pixel.

[0020] This implementation can be applied to scenarios where the parasitic capacitance of the G sub-pixel is large and the charging time is long, that is, the scenario where the G sub-pixel has a long luminous response time. This scenario usually causes the color generated after the light emission of each sub-pixel is mixed to be reddish, bluish or purplish. Therefore, by reducing the resistance value of the second light-emitting branch, that is, reducing the resistance value of the branch where the G sub-pixel is located, the driving current can be increased, the charging time of the parasitic capacitance of the G sub-pixel can be reduced, and thus the luminous response time of the G sub-pixel can be shortened to match the luminous response times of the R sub-pixel and the B sub-pixel.

[0021] 2) When the brightness is switched, increase the resistance value of the first light-emitting branch to extend the luminous response time of the red sub-pixel.

[0022] This implementation can be applied to scenarios where the parasitic capacitance of the R sub-pixel is small and the charging time is short, that is, the scenario where the R sub-pixel has a short luminous response time. This scenario usually causes the color generated after the light emission of each sub-pixel is mixed to be reddish. Therefore, by increasing the resistance value of the first light-emitting branch, that is, increasing the resistance value of the branch where the R sub-pixel is located, the driving current can be reduced, the charging time of the parasitic capacitance of the R sub-pixel can be increased, and thus the luminous response time of the R sub-pixel can be increased to match the luminous response times of the G sub-pixel and the B sub-pixel.

[0023] 3) When the brightness is switched, increase the resistance value of the third light-emitting branch to extend the luminous response time of the blue sub-pixel.

[0024] This implementation can be applied to scenarios where the parasitic capacitance of the B sub-pixel is small and the charging time is short, that is, the scenario where the B sub-pixel has a short luminous response time. This scenario usually causes the color generated after the light emission of each sub-pixel is mixed to be bluish. Therefore, by increasing the resistance value of the third light-emitting branch, that is, increasing the resistance value of the branch where the B sub-pixel is located, the driving current can be reduced, the charging time of the parasitic capacitance of the B sub-pixel can be increased, and thus the luminous response time of the B sub-pixel can be increased to match the luminous response times of the G sub-pixel and the R sub-pixel.

[0025] The above three scenarios can be combined and applied. For example, in a scenario where the parasitic capacitances of the R sub-pixel and the B sub-pixel are both small and the charging times are both short, the color generated after the light emission of each sub-pixel is mixed will be reddish, bluish or purplish. Therefore, by increasing the resistance values of the branches where the R sub-pixel and the B sub-pixel are located, the driving current can be reduced, the charging times of the parasitic capacitances of the R sub-pixel and the B sub-pixel can be increased, and thus the luminous response times of the R sub-pixel and the B sub-pixel can be increased to match the luminous response time of the G sub-pixel.

[0026] For another example, in a scenario where the parasitic capacitance of the G sub-pixel is large and the charging time is long, while the parasitic capacitances of the R and B sub-pixels are both small and the charging times are both short, the resistance value of the branch where the G sub-pixel is located can be reduced to increase the driving current and reduce the charging time of the parasitic capacitance of the G sub-pixel, thereby shortening the light-emitting response time of the G sub-pixel; and the resistance values of the branches where the R and B sub-pixels are located can be increased to reduce the driving current and increase the charging times of the parasitic capacitances of the R and B sub-pixels, thereby increasing the light-emitting response times of the R and B sub-pixels; ultimately achieving the effect of matching the light-emitting response times of each of the G, R, and B sub-pixels.

[0027] Figure 2 It is a schematic diagram of the capacitance characteristics of the sub-pixel light-emitting material provided by an embodiment of the present application. As Figure 2 shown, the parasitic capacitance of the G sub-pixel is the largest, and the parasitic capacitances of the R and B sub-pixels are relatively small. Therefore, under the same driving current / voltage, the charging time of the parasitic capacitance of the G sub-pixel is the longest, and the charging times of the parasitic capacitances of the R and B sub-pixels are relatively short.

[0028] Figure 3 It is a schematic diagram of the turn-on characteristics of the sub-pixel light-emitting material provided by an embodiment of the present application. As Figure 3 shown, in the case of generating the same driving current / voltage based on the light-emitting signal, the response speed of the G sub-pixel is the slowest, and the light-emitting response time reaches the target brightness only after about 3 ms. The response speeds of the R and B sub-pixels are relatively fast, and the light-emitting response times of both reach the target brightness only after about 1 ms.

[0029] Based on the capacitance characteristics and turn-on characteristics of the above-mentioned sub-pixel light-emitting material, in an embodiment of the present application, the resistance value adjustment module adjusts the resistance value of at least one light-emitting branch when the brightness is switched, so that the light-emitting response times of each sub-pixel of the light-emitting element match, which can improve the problem of color ghosting and color deviation generated after the light emission of the red, green, and blue sub-pixels is mixed, avoid the phenomenon of being reddish or purplish, and improve the display effect.

[0030] In an embodiment of the present application, the resistance value adjustment module 200 can adjust the resistance value of at least one light-emitting branch within the charging time of the parasitic capacitance of the light-emitting element 300, so that the light-emitting response times of each sub-pixel of the light-emitting element 300 match. Among them, the charging time of the parasitic capacitance of the light-emitting element 300 refers to the time for charging the parasitic capacitance after the light-emitting element 300 ends the non-light-emitting stage and before starting to emit light during the light-emitting stage.

[0031] During the non - charging time of the parasitic capacitance of the light - emitting element 300, the resistance - value regulation module 200 can reduce the resistance value of at least one light - emitting branch to a first voltage value, so as to increase the driving current to a second current value. Among them, the first voltage value can be the minimum voltage value, and the second current value can be the maximum current value. Among them, the non - charging time of the above - mentioned parasitic capacitance includes: the non - lighting stage of the light - emitting element 300, and the stage from the start of lighting to the end of lighting after the parasitic capacitance is charged during the lighting stage. Boosting the driving current to the second current value (such as the maximum current value) during the non - charging time of the parasitic capacitance can reduce the current impact on the light - emitting element due to the connection resistance, reduce the impact on the display effect, and ensure the quality of the displayed content.

[0032] In one implementation, the resistance - value regulation module 200 is used to adjust the resistance value of at least one light - emitting branch when the brightness is switched, so that the error between the light - emitting response times of the sub - pixels of the light - emitting element 300 is less than a threshold value.

[0033] Among them, the above - mentioned threshold value can be set as needed, and the specific value is not limited. The error between the light - emitting response times of the sub - pixels being less than the threshold value means that the light - emitting response times of the sub - pixels are relatively close, so the light - emitting response times of the sub - pixels can be regarded as matching.

[0034] Exemplarily, the resistance - value regulation module 200 is used to adjust the resistance value of at least one light - emitting branch when the brightness is switched, so that the light - emitting response times of the sub - pixels of the light - emitting element 300 are the same.

[0035] In the scenario where the light - emitting response times of the above - mentioned sub - pixels are the same, the red sub - pixel, the green sub - pixel, and the blue sub - pixel can complete the charging process of the parasitic capacitance within the same time, start emitting light at the same moment, so that the problem of color smear and color deviation after color mixing can be avoided, and the phenomenon of being reddish or purplish can be avoided, which can improve the display effect.

[0036] In the embodiment of the present application, the resistance - value regulation module 200 may include at least one of the following: the resistance - value regulation unit of the red sub - pixel, the resistance - value regulation unit of the green sub - pixel, and the resistance - value regulation unit of the blue sub - pixel.

[0037] Among them, the resistance - value regulation unit of the red sub - pixel is connected to the red sub - pixel to form a first light - emitting branch, the resistance - value regulation unit of the green sub - pixel is connected to the green sub - pixel to form a second light - emitting branch, and the resistance - value regulation unit of the blue sub - pixel is connected to the blue sub - pixel to form a third light - emitting branch.

[0038] Among them, any one of the resistance - value regulation units of the red sub - pixel, the resistance - value regulation unit of the green sub - pixel, and the resistance - value regulation unit of the blue sub - pixel may include: N parallel resistors and N parallel switches, each resistor is in series with a switch, and each switch is used to control the turn-off and connection of the resistor in series with it when the brightness is switched, where N is a positive integer.

[0039] Among them, the resistance value control unit of any one of the above sub-pixels determines the resistance value of the corresponding light-emitting branch by controlling the number of resistors connected by N switches, so that the light-emitting response time of any one sub-pixel matches the light-emitting response time of other sub-pixels.

[0040] Among them, the resistance values of the above N resistors can be the same or different, and there is no specific limitation. For example, the resistance values of the N resistors are all R1, or the resistance values of the N resistors are R1, R2,..., RN in sequence.

[0041] In the embodiments of the present application, the circuit for improving display smear and color cast can be any one of the following types: 7T1CLTPS, 7T1CLTPO, 8T1C LTPS, 8T1C LTPO, and there is no specific limitation. Hereinafter, the circuit for improving display smear and color cast will be introduced by taking the 8T1C LTPO type as an example.

[0042] Figure 4 It is a schematic structural diagram of the 8T1C LTPO circuit provided by the embodiments of the present application. As Figure 4 shown, the circuit for improving display smear and color cast includes 8 TFTs (T1~T8), 1 capacitor Cst and 1 OLED. Among them, T1, T2, T5, T6, T7 and T8 are all P-type TFTs, which are in the on state at low level and in the off state at high level. T3 and T4 are N-type TFTs, which are in the off state at low level and in the on state at high level.

[0043] Figure 4T5, T1, and T6 in it form the light-emitting control and driving module 100, which provides driving current to the light-emitting element 300 based on the light-emitting signal EM. The light-emitting element 300 is specifically an OLED, which emits light under the action of the driving current provided by the light-emitting control and driving module 100. Each of the first light-emitting branch, the second light-emitting branch, and the third light-emitting branch includes N switches and N resistors as shown in the figure, where N is a positive integer. Among them, the N switches include: W1, W2, W3, W4, ……, WN. The N resistors include: R1, R2, R3, R4, ……, RN. Each switch is connected in series with a resistor and then connected in parallel with each other. The resistance values of the N resistors can be the same or different, and there is no specific limitation. When the resistance values of the N resistors are all different, the total resistance value after the N resistors are connected in parallel is R0 = 1 / (1 / R1 + 1 / R2 + 1 / R3 + 1 / R4 + … + 1 / RN). When the resistance values of the N resistors are the same, for example, when the resistance values of the N resistors are all R1, the total resistance value after the N resistors are connected in parallel is R0 = R1 / N. In different scenarios, some or all of the N resistors can be selected to be connected in parallel, and the number of resistors connected in parallel is determined by the N switches, and then different total resistance values, that is, the resistance values of the branches where they are located, can be obtained. When the brightness is switched, the resistance value adjustment module 200 can make the light-emitting response times of the sub-pixels match by adjusting the resistance values of at least one light-emitting branch.

[0044] For example, in the scenario where the light-emitting response time of the R sub-pixel is the shortest, the resistance value adjustment module 200 can reduce the driving current by increasing the resistance value of the first light-emitting branch, such as disconnecting more resistors by switch selection. Since the fewer the resistors connected in parallel, the greater the total resistance value after parallel connection, and this total resistance value is the resistance value of the first light-emitting branch where the R sub-pixel is located. Therefore, after disconnecting more resistors, the resistance value of the first light-emitting branch becomes larger, and the charging time of the parasitic capacitance becomes longer, thereby increasing the light-emitting response time of the R sub-pixel to match the light-emitting response times of the G sub-pixel and the B sub-pixel.

[0045] Again, in the scenario where the light-emitting response time of the G sub-pixel is the longest, the resistance value adjustment module 200 can increase the driving current by reducing the resistance value of the second light-emitting branch, such as connecting more resistors by switch selection. Since the more the resistors connected in parallel, the smaller the total resistance value after parallel connection, and this total resistance value is the resistance value of the second light-emitting branch where the G sub-pixel is located. Therefore, after connecting more resistors, the resistance value of the second light-emitting branch becomes smaller, and the charging time of the parasitic capacitance is shortened, thereby shortening the light-emitting response time of the G sub-pixel to match the light-emitting response times of the R sub-pixel and the B sub-pixel.

[0046] In the embodiments of the present application, within one frame time of display refreshing, the driving timing process of the circuit for improving display smear and color cast may include multiple stages, which are specifically related to the frequency of display refreshing and the frequencies of light-emitting element reset and driving bias compensation. If the frequency of display refreshing is the same as the frequencies of light-emitting element reset and driving bias compensation, the driving timing process may include 4 stages: stages t1 to t4. If the frequency of display refreshing is less than the frequencies of light-emitting element reset and driving bias compensation, the driving timing process may include 5 stages: stages t1 to t4 and a repetition stage.

[0047] Figure 5 provided by the embodiments of the present application Figure 4 is the driving timing diagram of the circuit shown. As Figure 5 shown, the frequency of display refreshing of the circuit for improving display smear and color cast is 120 Hz, and the frequencies of light-emitting element reset and driving bias compensation are 360 Hz. Pscan1 is the gate control signal of T7 and T8, Pscan2 is the gate control signal of T2, Nscan1 is the gate control signal of T3, Nscan2 is the gate control signal of T4, and EM is the light-emitting signal and also the gate control signal of T5 and T6. Combining Figure 4 and Figure 5 , the driving timing process of the above-mentioned circuit for improving display smear and color cast may include the following 5 stages.

[0048] (1) Stage t1 (capacitor reset stage): The gate control signal Nscan2 of T4 is at a high level, the gate control signals Pscan1 of T7 and T8 are at a high level, the gate control signal Pscan2 of T2 is at a high level, the gate control signal Nscan1 of T3 is at a low level, T4 is turned on, and the initialization voltage Vint1 (negative voltage) is written to point A of the gate of T1 and stored on the capacitor Cst for holding.

[0049] (2) Stage t2 (data writing and threshold voltage compensation stage): The gate control signal Nscan1 of T3 is at a high level, the gate control signals Pscan1 of T7 and T8 are at a high level, the gate control signal Pscan2 of T2 is at a low level, the gate control signal Nscan2 of T4 is at a low level, T2 and T3 are turned on, the gate and drain of T1 are short-circuited, and the potential at point A |VA| > |Vth|, T1 is turned on, the display 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 potential at point A becomes Vdata - |Vth|. Here, Vdata is the input display data voltage, and Vth is the threshold voltage of T1 itself. Through this operation, the threshold voltage Vth of T1 is extracted and compensated for the threshold voltage of T1.

[0050] (3) Stage t3 (OLED reset and drive bias compensation stage): The gate control signal Pscan1 of T7 is at a low level, the gate control signal Nscan1 of T3 is at a low level, the gate control signal Nscan2 of T4 is at a low level, the gate control signal Pscan2 of T2 is at a high level, and T7 is turned on. At this time, the anode of the OLED is connected to Vint2 and the cathode is connected to the negative voltage ELVSS. The reset 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. At this time, the anode potential of the OLED is the Vint2 voltage. The gate control signal Pscan1 of T8 is at a low level, and T8 is also turned on. The source of T1 is connected to the bias compensation voltage Vint3 to perform bias compensation on T1.

[0051] The above stages t1 to t3 are the stages when the OLED does not emit light.

[0052] (4) Stage t4 (light-emitting stage): The gate control signals EM (light-emitting signals) of T5 and T6 are at a low level, the gate control signal Nscan1 of T3 is at a low level, the gate control signal Nscan2 of T4 is at a low level, the gate control signals Pscan1 of T7 and T8 are at a high level, the gate control signal Pscan2 of T2 is at a high level, and T5 and T6 are turned on. At this time, the gate of T1 is also in an on state under the action of the voltage Vdata - |Vth| stored at point A of the Cst capacitor, and the drive current flows from the positive voltage ELVDD through T5, T1, T6, and the OLED to the negative voltage ELVSS, and the OLED emits light.

[0053] Among them, ELVDD is a constant positive voltage, usually 4.6V, and ELVSS is an adjustable negative voltage output by the power supply chip controlled by the display driver chip.

[0054] The above stage t4 is the stage when the OLED emits light.

[0055] (5) Repetition stage: Since the frequency of the reset of the light-emitting element and the drive bias compensation is 360Hz, the gate control signals Pscan1 of T7 and T8 and the gate control signals EM of T5 and T6 are repeated 3 times in the timing within one frame time (120Hz) of the display refresh.

[0056] In the embodiment of the present application, the resistance regulation unit of any sub-pixel in the resistance regulation module 200 closes N switches to connect N resistors in parallel and then connect them to the corresponding sub-pixel during the non-charging time of the parasitic capacitance of the light-emitting element, so as to reduce the resistance of the branch to the first voltage value and increase the drive current to the second current value. In this case of closing N switches, the first voltage value can reach the minimum voltage value, and the second current value can reach the maximum current value.

[0057] Among them, Figure 5 During one frame time of 120Hz as shown, in the timing sequence of the red sub-pixel of the light-emitting element (the row shown by Rr): the three high-level stages correspond to the charging time of the parasitic capacitance of the red sub-pixel. The resistance value connected to the red sub-pixel at this stage is Rr1; all the remaining low-level stages correspond to the non-charging time of the parasitic capacitance of the red sub-pixel. The resistance value connected to the red sub-pixel at this stage is the minimum value, such as Rn = R1 / N, that is, the resistance value of N resistors with a resistance value of R1 in parallel is Rn. At this time, the driving current of the OLED is the largest.

[0058] Among them, Figure 5 During one frame time of 120Hz as shown, in the timing sequence of the green sub-pixel of the light-emitting element (the row shown by Rg): the three high-level stages correspond to the charging time of the parasitic capacitance of the green sub-pixel. The resistance value of the second light-emitting branch where the green sub-pixel is located at this stage is Rg1; all the remaining low-level stages correspond to the non-charging time of the parasitic capacitance of the green sub-pixel. The resistance value of the second light-emitting branch where the green sub-pixel is located at this stage is the minimum value, such as Rn = R1 / N, that is, the resistance value of N resistors with a resistance value of R1 in parallel is Rn. At this time, the driving current of the OLED is the largest.

[0059] Among them, Figure 5 During one frame time of 120Hz as shown, in the timing sequence of the blue sub-pixel of the light-emitting element (the row shown by Rb): the three high-level stages correspond to the charging time of the parasitic capacitance of the blue sub-pixel. The resistance value of the third light-emitting branch where the blue sub-pixel is located at this stage is Rb1; all the remaining low-level stages correspond to the non-charging time of the parasitic capacitance of the blue sub-pixel. The resistance value of the third light-emitting branch where the blue sub-pixel is located at this stage is the minimum value, such as Rn = R1 / N, that is, the resistance value of N resistors with a resistance value of R1 in parallel is Rn. At this time, the driving current of the OLED is the largest.

[0060] The above circuit for improving display ghosting and color cast provided by the embodiments of the present application provides a driving current to the light-emitting element through the light-emitting control and driving module based on the light-emitting signal. The light-emitting element includes a red sub-pixel, a green sub-pixel, and a blue sub-pixel, which are respectively connected to the resistance value regulation module to form a first light-emitting branch, a second light-emitting branch, and a third light-emitting branch. The light-emitting element emits light under the action of the driving current. When the brightness is switched, the resistance value regulation module adjusts the resistance value of at least one light-emitting branch so that the light-emitting response times of the sub-pixels of the light-emitting element match, which can improve the problem of color ghosting and color cast generated after the red, green, and blue sub-pixels emit light in a mixed color, avoid the phenomenon of being too red or too purple, and improve the display effect.

[0061] In addition, by increasing the driving current to the second current value (such as the maximum current value) during the non-charging time of the parasitic capacitance of any sub-pixel, the current influence on the light-emitting element caused by the connection resistance can be reduced, the influence on the display effect can be reduced, and the quality of the displayed content can be ensured.

[0062] Figure 6 shows an electronic device provided by an embodiment of the present application. For example, Figure 6 as shown, the electronic device 600 includes a display panel 601 and a circuit 602 for improving display smear and color cast as described in any of the above embodiments. Among them, the function of the circuit for improving display smear and color cast is the same as the function described in the above embodiments and can achieve the same technical effects, which will not be elaborated here.

[0063] The above electronic device provided by the embodiment of the present application can improve the problem of color smear and color cast generated after the light emission mixing of red, green, and blue sub-pixels, avoid the phenomenon of being reddish or purplish, and improve the display effect.

[0064] It should be noted that the electronic devices in the embodiments of the present application include mobile electronic devices and non-mobile electronic devices.

[0065] It should be noted that in this article, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article or device including that 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 a reverse order according to the functions involved. For example, the methods described 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.

[0066] Through the description of the above embodiments, those skilled in the art can clearly understand that the above embodiment methods can be implemented by means of software plus a necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, can be embodied in the form of a computer software product. The computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disc) and includes several instructions for causing a terminal (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in various embodiments of the present application.

[0067] The embodiments of the present application have been described above in conjunction with the accompanying drawings. However, the present application is not limited to the above specific embodiments. The above specific embodiments are merely illustrative rather than restrictive. Those of ordinary skill in the art, under the inspiration of the present application and without departing from the purpose of the present application and the scope protected by the claims, can also make many forms, all of which fall within the protection scope of the present application.

Claims

1. A circuit for improving display smear and color cast, characterized in that: include: Light-emitting control and driving module, resistance value regulating module and light-emitting element; The light emitting control and driving module is connected to the light emitting element through the resistance value regulating module, and the light emitting control and driving module is used to provide a driving current to the light emitting element based on the light emitting signal; The light-emitting element includes a red sub-pixel, a green sub-pixel and a blue sub-pixel, the red sub-pixel is connected to the resistance control module to form a first light-emitting branch, the green sub-pixel is connected to the resistance control module to form a second light-emitting branch, and the blue sub-pixel is connected to the resistance control module to form a third light-emitting branch, and the light-emitting element is used to emit light under the action of the driving current provided by the light-emitting control and driving module; The resistance control module is used to adjust the resistance of at least one light-emitting branch when the brightness is switched so that the light-emitting response time of each sub-pixel of the light-emitting element matches, wherein the light-emitting branch includes the first light-emitting branch, the second light-emitting branch and the third light-emitting branch.

2. The circuit according to claim 1, characterized in that The resistance control module is used to perform at least one of the following: When the brightness is switched, the resistance of the second light-emitting branch is reduced to shorten the light-emitting response time of the green sub-pixel; When the brightness is switched, the resistance of the first light-emitting branch is increased to extend the light-emitting response time of the red sub-pixel; When the brightness is switched, the resistance of the third light-emitting branch is increased to extend the light-emitting response time of the blue sub-pixel.

3. The circuit according to claim 1, characterized in that The resistance control module adjusts the resistance of at least one light-emitting branch during the charging time of the parasitic capacitance of the light-emitting element, so as to match the light-emitting response time of each sub-pixel of the light-emitting element; The resistance control module reduces the resistance of at least one light-emitting branch to a first voltage value during the non-charging time of the parasitic capacitance of the light-emitting element, so as to increase the driving current to a second current value.

4. The circuit according to any one of claims 1 to 3, characterized in that: The resistance control module is used to adjust the resistance of at least one light-emitting branch when the brightness is switched, so that the error between the light-emitting response times of each sub-pixel of the light-emitting element is less than a threshold value.

5. The circuit according to claim 4, characterized in that The resistance control module is used to adjust the resistance of at least one light-emitting branch when the brightness is switched, so that the light-emitting response time of each sub-pixel of the light-emitting element is the same.

6. The circuit according to claim 1, characterized in that The resistance control module includes at least one of the following: a resistance control unit for a red sub-pixel, a resistance control unit for a green sub-pixel, and a resistance control unit for a blue sub-pixel; The resistance control unit of the red sub-pixel is connected to the red sub-pixel to form the first light-emitting branch, the resistance control unit of the green sub-pixel is connected to the green sub-pixel to form the second light-emitting branch, and the resistance control unit of the blue sub-pixel is connected to the blue sub-pixel to form the third light-emitting branch; Wherein, the resistance value control unit of any sub-pixel includes: N resistors connected in parallel and N switches connected in parallel, each resistor is connected in series with a switch, and each switch is used to control the disconnection and connection of the resistor connected in series with it when the brightness is switched, and N is a positive integer; The resistance control unit of any sub-pixel determines the resistance of the corresponding light-emitting branch by controlling the number of resistors connected by the N switches, so that the light-emitting response time of any sub-pixel matches the light-emitting response time of other sub-pixels.

7. The circuit according to claim 6, characterized in that The resistance values ​​of the N resistors are the same or different.

8. The circuit according to claim 6, characterized in that The resistance control unit of any sub-pixel closes the N switches during the non-charging time of the parasitic capacitance of the light-emitting element so that the N resistors are connected in parallel and then in series with the corresponding sub-pixels, so that the resistance of the corresponding light-emitting branch is reduced to the first voltage value and the driving current is increased to the second current value.

9. The circuit according to any one of claims 1 to 3, characterized in that: The circuit is any of the following types: 7T1C low temperature polysilicon LTPS, 7T1C low temperature polycrystalline oxide LTPO, 8T1C LTPS, 8T1C LTPO.

10. An electronic device, characterized in that: include: A display panel and a circuit for improving display smear and color cast as claimed in any one of claims 1 to 9.

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