Pixel Circuit and Driving Method Thereof

Abstract

The present invention discloses a pixel circuit and a driving method thereof. The pixel circuit comprises: a data writing unit for controlling the input of a data signal; an energy storage unit, the first end of which is connected to the output end of the data writing unit, for storing the data signal output by the data writing unit; a light-emitting unit for performing light-emitting display; a first light-emitting control unit, the input end of which is connected to a high level VDD, the control end of which inputs a control signal, and the output end of which is connected to the first end of the energy storage unit; a driving transistor, the gate end of which is connected to the second end of the energy storage unit, and the input end of which is connected to the output of the first light-emitting control unit; a second light-emitting control unit; and a compensation unit. The present invention proposes a new pixel circuit and a driving method, and the light-emitting current is independent of the threshold voltage of TD, thereby eliminating the influence of the threshold voltage difference on the display.

Description

Technical Field

[0001] The present application relates to the field of display technologies, and particularly to a pixel circuit and a driving method thereof. Background Art

[0002] Organic Light Emitting Diode (OLED) is one of the hotspots in the current research field of flat panel displays. Compared with liquid crystal displays, OLEDs have the advantages of low power consumption, low production cost, self-luminescence, wide viewing angle, and fast response speed. Currently, in the flat panel display fields such as mobile phones, PDAs, and digital cameras, OLEDs have begun to replace traditional liquid crystal displays (LCDs). Among them, the design of the driving circuit is a key technology for realizing the display function.

[0003] The driving circuit generally can include a scan driving circuit, a light emission control circuit, a data driving circuit, a pixel circuit, etc. Among them, the pixel circuit design is the core technical content of OLED displays and has important research significance.

[0004] With the development of display technologies, people's requirements for display effects are also getting higher and higher. However, due to the different physical structures and electrical characteristics of semiconductor devices among different pixels, there are threshold differences in driving transistors in semiconductor devices, and the problem becomes more significant as the size of the display panel increases, resulting in uneven display. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the present invention provides a pixel circuit and a driving method thereof.

[0006] The present invention provides a pixel circuit, including:

[0007] A data writing unit, configured to control the input of a data signal;

[0008] An energy storage unit, with its first end connected to the output end of the data writing unit, configured to store the data signal output by the data writing unit;

[0009] A light emitting unit, configured to perform light emitting display;

[0010] A first light emission control unit, with its input end connected to a high level VDD, its control end inputting a control signal, and its output end connected to the first end of the energy storage unit;

[0011] A driving transistor, with its gate end connected to the second end of the energy storage unit and its input end connected to the output of the first light emission control unit;

[0012] A second light-emitting control unit, whose control terminal inputs a light-emitting enable signal, whose input terminal is connected to the output of a driving transistor, and whose output terminal is used to provide a light-emitting current to a light-emitting unit;

[0013] A compensation unit, whose first terminal is connected to the second terminal of the energy storage unit, whose second terminal is connected to the output terminal of the driving transistor, and whose control terminal inputs a compensation control signal.

[0014] Optionally, it further includes: a first reset unit, which is connected to the input terminal of the light-emitting unit and is used to reset the light-emitting unit.

[0015] Optionally, it further includes: a second reset unit, which is connected to the second terminal of the energy storage unit and is used to reset the energy storage unit.

[0016] Optionally, the data writing unit includes: a second PMOS transistor, whose source is connected to a data signal.

[0017] Optionally, the energy storage unit includes: a capacitor, whose first terminal is connected to the drain of the second PMOS transistor of the data writing unit.

[0018] Optionally, the first light-emitting control unit includes a first PMOS transistor, whose source is connected to a high level VDD and whose gate is connected to a control signal.

[0019] Optionally, the driving transistor is a silicon MOS transistor.

[0020] Optionally, the second light-emitting control unit includes a fifth PMOS transistor, whose source is connected to the drain of the driving transistor and whose gate is connected to a light-emitting enable signal.

[0021] Optionally, the driving transistor is a silicon PMOS transistor; the compensation unit includes: a fourth PMOS transistor, whose drain is connected to the second terminal of the capacitor, whose source is connected to the drain of the driving transistor, and whose gate is connected to a compensation control signal.

[0022] Optionally, the first reset unit includes: a sixth PMOS transistor, whose drain is connected to the input terminal of the light-emitting unit, whose gate is connected to a reset control signal, and whose source inputs a reset signal; it further includes a second reset unit, and the second reset unit includes: a third PMOS transistor, whose drain is connected to the second terminal of the energy storage unit, whose gate is connected to a reset control signal, and whose source inputs a reset signal.

[0023] Optionally, the first reset unit includes: a third PMOS transistor, whose drain is connected to the output terminal of the driving transistor, whose gate is connected to a reset control signal, and whose source is connected to a reset signal.

[0024] Optionally, the first reset unit includes: a third PMOS transistor, whose source receives a reset signal, gate receives a reset control signal, and drain is connected to the second end of the energy storage unit.

[0025] A driving method for a pixel circuit, comprising the steps of:

[0026] In the initialization stage, the first reset unit and the second reset unit are turned on, the first light-emitting control unit, the data writing unit, the compensation unit, and the second light-emitting control unit are turned off, and the energy storage unit and the light-emitting unit are initialized.

[0027] In the data writing stage, the first light-emitting control unit, the compensation unit, and the second light-emitting control unit are turned off, the data writing unit, the first reset unit, and the second reset unit are turned on, and data is written.

[0028] In the threshold voltage compensation stage, the first light-emitting control unit, the second light-emitting control unit, the first reset unit, and the second reset unit are turned off, the data writing unit and the compensation unit are turned on, until Vdata - Vg = a * (VDD - Vdata) + |Vth|, where a is the body bias coefficient.

[0029] In the light-emitting stage, the first light-emitting control unit and the second light-emitting control unit are turned on, the data writing unit, the compensation unit, the first reset unit, and the second reset unit are turned off.

[0030] Ioled = β * (V sg - |Vth|) 2 = β * a 2 * (VDD - Vdata) 2 .

[0031] A driving method for a pixel circuit, comprising the steps of:

[0032] In the initialization and data writing stage, the first light-emitting control unit and the second light-emitting control unit are turned off, the data writing unit, the compensation unit, and the first reset unit are turned on, and the energy storage unit is initialized and data is written.

[0033] In the threshold voltage Vth compensation stage, the first light-emitting control unit, the second light-emitting control unit, and the first reset unit are turned off, the data writing unit and the compensation unit are turned on, and data is written until

[0034] Vdata - Vg = a * (VDD - Vdata) + |Vth|, where a is the body bias coefficient.

[0035] In the anode initialization stage, the first light-emitting control unit, the data writing unit, and the compensation unit are turned off, and the first reset unit and the second light-emitting control unit are turned on.

[0036] During the light-emitting stage, the first reset unit, the data writing unit, and the compensation unit are turned off, and the first light-emitting control unit and the second light-emitting control unit are turned on.

[0037] Ioled = β * (V sg -|Vth|) 2 = β * a 2 * (VDD - Vdata) 2 .

[0038] A driving method for a pixel circuit includes the steps of:

[0039] During the anode initialization stage, the first light-emitting control unit and the data writing unit are turned off, and the compensation unit, the second light-emitting control unit, and the first reset unit are turned on;

[0040] During the data writing stage, the first light-emitting control unit, the second light-emitting control unit, and the compensation unit are turned off, the data writing unit and the first reset unit are turned on, and data is written to the source of the data writing driving transistor;

[0041] During the threshold voltage Vth compensation stage, the first light-emitting control unit, the first reset unit, and the second light-emitting control unit are turned off, the data writing unit and the compensation unit are turned on until

[0042] Vdata - Vg = a * (VDD - Vdata) + |Vth|, where a is the body bias coefficient;

[0043] During the light-emitting stage, the first reset unit, the data writing unit, and the compensation unit are turned off, and the first light-emitting control unit and the second light-emitting control unit are turned on.

[0044] Ioled = β * (V sg -|Vth|) 2 = β * a 2 * (VDD - Vdata) 2 .

[0045] The OLED light-emitting current of the present invention is independent of the threshold voltage of TD, thereby eliminating the influence of threshold voltage differences on display. Description of the Drawings

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0047] Figure 1 It is a schematic structural diagram of a pixel circuit according to an embodiment of the present invention;

[0048] Figure 2 The circuit diagram of the pixel circuit according to the first embodiment of the present invention;

[0049] Figure 3 is Figure 2 The timing diagram of the driving method of the pixel circuit shown;

[0050] Figure 4 The circuit diagram of the pixel circuit according to the second embodiment of the present invention;

[0051] Figure 5 is Figure 4 The timing diagram of the driving method of the pixel circuit shown;

[0052] Figure 6 The circuit diagram of the pixel circuit according to the third embodiment of the present invention;

[0053] Figure 7 is Figure 6 The timing diagram of the driving method of the pixel circuit shown. Detailed implementation manners

[0054] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein.

[0055] In the present invention, unless otherwise stated, the directional terms such as "upper, lower" generally refer to the upper and lower in the normal use state of the device, and "inner, outer" refer to the inside and outside relative to the contour of the device. In addition, the terms "first, second, third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first, second, third" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined. Since the present invention is an electrical device, connection and interconnection both represent conductive interconnection. Since the drawings are descriptions of the same device, the same reference numerals in the drawings represent the same components.

[0056] The specific examples of the present invention will be further described in detail below with reference to the drawings. Figure 1 is a schematic structural diagram of the pixel circuit according to an embodiment of the present invention. As Figure 1 shown, the pixel circuit includes:

[0057] A data writing unit for controlling the input of a data signal; an energy storage unit having a first end connected to the output end of the data writing unit for storing the data signal output by the data writing unit; a light emitting unit for performing light emitting display; a first light emitting control unit having an input end connected to a high level VDD, a control end for inputting a control signal, and an output end connected to the first end of the energy storage unit; a driving transistor having a gate connected to the second end of the energy storage unit and an input end connected to the output of the first light emitting control unit; a second light emitting control unit having a control end for inputting a control signal, an input end connected to the output of the driving transistor, and an output end for providing a light emitting current to the light emitting unit; a compensation unit having a first end connected to the second end of the energy storage unit, a second end connected to the output end of the driving transistor, and a control end for inputting a compensation control signal.

[0058] Figure 2 is a circuit diagram of a pixel circuit according to the first embodiment of the present invention. In this embodiment,

[0059] S1 is a data control signal;

[0060] S2 is a compensation control signal;

[0061] S3 is a connection reset control signal;

[0062] EM is a control signal and a light emitting enable signal.

[0063] As Figure 2 shown:

[0064] In this embodiment, it further includes a first reset unit connected to the input end of the light emitting unit for resetting the light emitting unit.

[0065] In this embodiment, it further includes a second reset unit connected to the second end of the energy storage unit for resetting the energy storage unit.

[0066] In this embodiment, the data writing unit includes: a second PMOS transistor T2 having a source connected to the data signal DATA and a gate for inputting the data control signal S1.

[0067] In this embodiment, the energy storage unit includes: a capacitor C having a first end connected to the drain of the second PMOS transistor T2 of the data writing unit.

[0068] In this embodiment, the first light emitting control unit includes a first PMOS transistor T1 having a source connected to the high level VDD and a gate connected to the control signal EM.

[0069] In this embodiment, the driving transistor TD is a silicon-based MOS transistor, preferably a PMOS transistor. In other embodiments, the driving transistor TD can also be other semiconductor substrates, so that the body bias effect can better combine with the present invention to improve the implementation effect.

[0070] In this embodiment, the second light-emitting control unit includes a fifth PMOS transistor T5, whose source is connected to the drain of the driving transistor TD, the gate is connected to the control signal EM, and the drain is connected to the input end of the light-emitting unit.

[0071] In this embodiment, the compensation unit includes: a fourth PMOS transistor T4, whose drain is connected to the second end of the capacitor C, the source is connected to the drain of the driving transistor TD, and the gate is connected to the compensation control signal S2.

[0072] In this embodiment, the first reset unit includes: a sixth PMOS transistor, whose drain is connected to the input end of the light-emitting unit, the gate is connected to the reset control signal S3, and the source inputs the reset signal Vdis; it further includes a second reset unit, and the second reset unit includes: a third PMOS transistor, whose drain is connected to the second end of the energy storage unit, the gate is connected to the reset control signal S3, and the source inputs the reset signal Vinit.

[0073] In other embodiments, the specific structures of the above units can also be selected in various combinations, all within the protection scope of the invention, and the circuit in this embodiment does not constitute a specific limitation. Among them, the driving transistor is preferably a silicon-based MOS transistor, and other circuits are not limited. They can be silicon-based or glass-based devices, etc. They can be fabricated on a silicon-based chip with the driving transistor, or they can be other separately structured packaging combinations.

[0074] As Figure 2 shown, in this embodiment, the pixel of this solution consists of 7T1C. Among them, the source and drain of the transistor T1 are respectively connected to the VDD trace and the source S point of TD, the upper and lower substrates of C are respectively connected to the source and gate of TD, the source and drain of T2 are respectively connected to DATA and the source of TD, the source and drain of T3 are respectively connected to the gate of TD and Vinit, the source and drain of T4 are respectively connected to the drain and gate of TD, the source and drain of T5 are respectively connected to the drain of TD and the anode of the OLED, and the source and drain of T6 are respectively connected to Vdis and the anode of the OLED.

[0075] The present invention also provides a driving method for a pixel circuit, including the steps:

[0076] In the initialization stage, the first reset unit and the second reset unit are turned on, the first light-emitting control unit, the data writing unit, the compensation unit, and the second light-emitting control unit are turned off, and the energy storage unit and the light-emitting unit are initialized;

[0077] During the data writing stage, the first light-emitting control unit, the compensation unit, and the second light-emitting control unit are turned off, the data writing unit, the first reset unit, and the second reset unit are turned on, and data is written.

[0078] During the threshold voltage compensation stage, the first light-emitting control unit, the second light-emitting control unit, the first reset unit, and the second reset unit are turned off, the data writing unit and the compensation unit are turned on, until Vdata - V g = a * (VDD - Vdata) + |Vth|, where a is the body bias coefficient;

[0079] During the light-emitting stage, the first light-emitting control unit and the second light-emitting control unit are turned on, and the data writing unit, the compensation unit, the first reset unit, and the second reset unit are turned off.

[0080] Ioled = β * (V sg - |Vth|) 2 = β * a 2 * (VDD - Vdata) 2 .

[0081] Figure 3 is Figure 2 the timing diagram of the driving method of the pixel circuit shown below. The driving method of the pixel circuit shown below will be described in conjunction with the specific working process. Figure 2 The driving method of the pixel circuit shown below will be described.

[0082] Combined with Figure 3 the corresponding timing, the working process of this solution is given.

[0083] First, in the ① initialization (init) stage, the first PMOS transistor T1 / the second PMOS transistor T2 / the fourth PMOS transistor T4 / the fifth PMOS transistor T5 are turned off, the third PMOS transistor T3 / the sixth PMOS transistor T6 are turned on, and the voltage at the g point (Nodeg): V g = Vinit, and the voltage at the input terminal of the light-emitting unit: Voled = Vdis.

[0084] After that, it enters the ② data writing stage. The first PMOS transistor T1 / the fourth PMOS transistor T4 / the fifth PMOS transistor T5 are turned off, the second PMOS transistor T2 / the third PMOS transistor T3 / the sixth PMOS transistor T6 are turned on, and the data DATA is written to the S point (Node S). The voltage at the S point is: V s = Vdata, V g = Vinit.

[0085] Then it enters the ③ threshold voltage Vth compensation stage. The first PMOS transistor T1, the third PMOS transistor T3, the fifth PMOS transistor T5, and the sixth PMOS transistor T6 are turned off, and the second PMOS transistor T2 and the fourth PMOS transistor T4 are turned on. There is current passing through the driving transistor TD to write to Node g.

[0086] until V data -V g = a * (VDD - Vdata) + |V th |, where a is the body bias coefficient.

[0087] Then it enters the ④ light-emitting stage. The second PMOS transistor T2, the third PMOS transistor T3, the fourth PMOS transistor T4, and the sixth PMOS transistor T6 are turned off, and the first PMOS transistor T1 and the fifth PMOS transistor T5 are turned on. The V sg voltage difference is the same as in ③

[0088] Ioled = β * (V sg - |V th |) 2 = β * a 2 * (VDD - Vdata) 2

[0089] It can be seen from the above formula that the OLED emission current is independent of the threshold voltage of TD, thus eliminating the influence of threshold voltage differences on display.

[0090] Second Embodiment

[0091] As Figure 4 shown, the same parts as the first embodiment will not be described in detail. The difference lies in: removing the sixth PMOS transistor T6, and the source and drain of the third PMOS transistor T3 are respectively connected to the reset signal Vinit and the drain of the driving transistor TD.

[0092] The first reset unit includes: a third PMOS transistor, whose drain is connected to the output end of the driving transistor, the gate is connected to the reset control signal, and the source is connected to the reset signal.

[0093] S1 is the data control signal and the compensation control signal;

[0094] S2 is the reset control signal;

[0095] S3 is the light-emitting enable signal;

[0096] EM is the control signal.

[0097] The present invention also provides another driving method for a pixel circuit, including the steps of:

[0098] In the initialization & data writing stage, the first light-emitting control unit and the second light-emitting control unit are turned off, and the data writing unit, the compensation unit, and the first reset unit are turned on to initialize the energy storage unit and write data.

[0099] In the threshold voltage Vth compensation stage, the first light-emitting control unit, the second light-emitting control unit, and the first reset unit are turned off, and the data writing unit and the compensation unit are turned on to write data until Vdata - V g = a * (VDD - Vdata) + |Vth|, where a is the body bias coefficient;

[0100] In the anode initialization stage, the first light-emitting control unit, the data writing unit, and the compensation unit are turned off, and the first reset unit and the second light-emitting control unit are turned on;

[0101] In the light-emitting stage, the first reset unit / data writing unit / compensation unit are turned off, and the first light-emitting control unit and the second light-emitting control unit are turned on.

[0102] Ioled = β * (V sg - |Vth|)^2 = β * a 2 * (VDD - Vdata) 2 .

[0103] Figure 5 Yes Figure 4 is the timing diagram of the driving method of the pixel circuit shown below. The driving method of the pixel circuit shown below will be described in conjunction with the specific working process. Figure 4 The driving method of the pixel circuit shown below will be described.

[0104] Combined with Figure 5 the corresponding timing, the working process of this solution is given as follows:

[0105] First, in the ① initialization (init) and data writing stage, the first PMOS transistor T1 / the fifth PMOS transistor T5 are turned off; the second PMOS transistor T2 / the third PMOS transistor T3 / the fourth PMOS transistor T4 are turned on, and the voltage at point S (Node S) is:

[0106] V s = Vdata V g = Vinit.

[0107] Then enter the ② data writing and threshold voltage Vth compensation stage. The first PMOS transistor T1 / the third PMOS transistor T3 / the fifth PMOS transistor T5 are turned off, and the second PMOS transistor T2 / the fourth PMOS transistor T4 are turned on. The data DATA is written to point S (Node S), and the voltage at point S is: V s = Vdata, V g= Vinit. There is current flowing through the driving transistor TD to write to Node g. Until Vdata - V g = a * (VDD - Vdata) + |Vth|, where a is the body bias coefficient;

[0108] After that, it enters the ③ anode initialization stage. The first PMOS transistor T1 / the second PMOS transistor T2 / the fourth PMOS transistor T4 are turned off, and the third PMOS transistor T3 / the fifth PMOS transistor T5 are turned on. The anode voltage of the light-emitting unit Voled = Vinit.

[0109] Then it enters the ④ light-emitting stage. The third PMOS transistor T3 / the second PMOS transistor T2 / the fourth PMOS transistor T4 are turned off, and the first PMOS transistor T1 / the fifth PMOS transistor T5 are turned on. The voltage difference between point S and point g, V sg Same as ②

[0110] I oled = β * (V sg - |V th |) 2 = β * a 2 * (VDD - Vdata) 2

[0111] It can be seen from the above formula that in this solution, the OLED emission current is also independent of the threshold voltage of TD, thus eliminating the influence of threshold voltage differences on display.

[0112] The third embodiment

[0113] As Figure 6 shown, the same parts as the first embodiment will not be described again. The difference lies in that it is composed of 6T1C, and the source and drain of T3 are connected to Vrefn and point g respectively.

[0114] The first reset unit includes: a third PMOS transistor, whose source inputs a reset signal, the gate inputs a reset control signal, and the drain is connected to the second end of the energy storage unit.

[0115] Where

[0116] S1 is a data control signal;

[0117] S2 is a reset control signal;

[0118] S3 is a light-emitting enable signal;

[0119] S4 is a compensation control signal;

[0120] EM is a control signal.

[0121] The present invention also provides another driving method for a pixel circuit, including the steps:

[0122] During the anode initialization stage, the first light emission control unit and the data writing unit are turned off, and the compensation unit, the second light emission control unit, and the first reset unit are turned on;

[0123] During the data writing stage, the first light emission control unit, the second light emission control unit, and the compensation unit are turned off, the data writing unit and the first reset unit are turned on, and data is written to the source of the data writing driving transistor;

[0124] During the threshold voltage Vth compensation stage, the first light emission control unit, the first reset unit, and the second light emission control unit are turned off, and the data writing unit and the compensation unit are turned on until Vdata - V g = a * (VDD - Vdata) + |Vth|, where a is the body bias coefficient;

[0125] During the light emission stage, the first reset unit / data writing unit / compensation unit are turned off, and the first light emission control unit and the second light emission control unit are turned on.

[0126] Ioled = β * (V sg - |Vth|) 2 = β * a 2 * (VDD - Vdata) 2 .

[0127] Figure 7 is Figure 6 the timing diagram of the driving method of the pixel circuit shown below. The driving method of the pixel circuit shown below will be described in conjunction with the specific working process. Figure 6 shown pixel circuit will be described.

[0128] Combined with Figure 7 the corresponding timing, the working process of this solution is given as follows:

[0129] First, during the ① anode initialization stage, the first PMOS transistor T1 / the second PMOS transistor T2 are turned off, and the third PMOS transistor T3 / the fourth PMOS transistor T4 / the fifth PMOS transistor T5 are turned on to initialize the anode.

[0130] Then, it enters the ② data writing stage. The first PMOS transistor T1 / the fourth PMOS transistor T4 / the fifth PMOS transistor T5 are turned off, and the second PMOS transistor T2 / the third PMOS transistor T3 are turned on, and Vdata is written to the source of TD.

[0131] Then, it enters the ③ threshold voltage Vth compensation stage. The first PMOS transistor T1 / the third PMOS transistor T3 / the fifth PMOS transistor T5 are turned off, and the second PMOS transistor T2 / the fourth PMOS transistor T4 are turned on, and current passes through TD and is written to Node g

[0132] Until Vdata - V g = a*(VDD - Vdata)+|Vth|, where a is the body bias coefficient.

[0133] Then enter the fourth light-emitting stage. In the fourth light-emitting stage, the third PMOS transistor T3 / the second PMOS transistor T2 / the fourth PMOS transistor T4 are turned off, and the first PMOS transistor T1 / the fifth PMOS transistor T5 are turned on. V sg The voltage difference is the same as in the second stage

[0134] Ioled = β*(V sg -|V th |)2 = β*a 2 *(VDD - Vdata) 2

[0135] It can be seen from the above formula that the OLED emission current is independent of the threshold voltage of TD, thus eliminating the influence of the threshold voltage difference on the display.

[0136] The present invention uses a silicon-based MOS transistor as a driving transistor. On the one hand, compared with a thin-film transistor, there will be a body bias effect. Due to the existence of this coefficient, the current expression of the final light-emitting unit of the present invention is:

[0137] Ioled = β*(V sg -|Vth|) 2 = β*a 2 *(VDD - Vdata) 2 = 0.5*u*Cox(W / L)*

[0138] a 2 (VDD - Vdata) 2

[0139] It can be seen that the final expression of the present invention contains a 2 (body bias coefficient, usually between 0 and 1). The existence of this coefficient is beneficial to expanding the range of the Vdata voltage, thus facilitating the expansion of the panel gray-scale voltage.

[0140] The above are only the embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present application, such as the mutual combination of technical features between embodiments, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present application.

Claims

1. A pixel circuit, characterized in that: include: A data writing unit, used for controlling the input of data signals; An energy storage unit, a first end of which is connected to the output end of the data writing unit and is used to store the data signal output by the data writing unit; The light-emitting unit is used for light-emitting display, and its input terminal initializes the voltage Voled=Vdis; A first light-emitting control unit, whose input terminal is connected to a high level VDD, whose control terminal inputs a control signal, and whose output terminal is connected to a first terminal of an energy storage unit; The gate end of the driving transistor is connected to the second end of the energy storage unit, i.e. point g, and its initialization voltage V g =Vinit, the input end is connected to the output of the first light-emitting control unit, i.e., point S; A second light-emitting control unit, a control terminal of which inputs a light-emitting enable signal, an input terminal of which is connected to the output of the driving transistor, and an output terminal of which is used to provide a light-emitting current to the light-emitting unit; A compensation unit, wherein a first end is connected to the second end of the energy storage unit, a second end is connected to the output end of the driving transistor, and a control end inputs a compensation control signal; A first reset unit, the first reset unit is connected to the input end of the light-emitting unit and is used to reset the light-emitting unit; it also includes: a second reset unit, the second reset unit is connected to the second end of the energy storage unit and is used to reset the energy storage unit; the data writing unit includes: a second PMOS transistor, whose source is connected to the data signal; the energy storage unit includes: a capacitor, whose first end is connected to the drain of the second PMOS transistor of the data writing unit; the first light-emitting control unit includes a first PMOS transistor, whose source is connected to the high level VDD, and the gate is connected to the control signal; the driving transistor is a silicon crystal MOS transistor; the second light-emitting control unit includes a fifth PMOS transistor, whose source is connected to the drain of the driving transistor, and the gate is connected to the light-emitting enable signal. The driving transistor is a silicon crystal PMOS transistor; the compensation unit includes: a fourth PMOS transistor, whose drain is connected to the second end of the capacitor, the source is connected to the drain of the driving transistor, and the gate is connected to the compensation control signal.

2. The pixel circuit according to claim 1, wherein: The first reset unit includes: a sixth PMOS transistor, whose drain is connected to the input end of the light-emitting unit, the gate is connected to the reset control signal, and the source is connected to the reset signal; and also includes a second reset unit, the second reset unit includes: a third PMOS transistor, whose drain is connected to the second end of the energy storage unit, the gate is connected to the reset control signal, and the source inputs the reset signal.

3. The pixel circuit according to claim 1, wherein: The first reset unit includes: a third PMOS transistor, a drain of which is connected to the output end of the driving transistor, a gate of which is connected to the reset control signal, and a source of which is connected to the reset signal.

4. The pixel circuit according to claim 1, wherein: The first reset unit includes: a third PMOS transistor, a source of which inputs a reset signal, a gate of which inputs a reset control signal, and a drain of which is connected to the second end of the energy storage unit.

5. A driving method for a pixel circuit according to claim 2, characterized in that: Includes steps: In the initialization stage, the first reset unit and the second reset unit are turned on, the first light-emitting control unit, the data writing unit, the compensation unit and the second light-emitting control unit are turned off, the energy storage unit and the light-emitting unit are initialized, the first PMOS transistor, the second PMOS transistor, the fourth PMOS transistor and the fifth PMOS transistor are turned off, the third PMOS transistor and the sixth PMOS transistor are turned on, and the voltage at point g is: V g =Vinit, light-emitting unit input voltage: Voled = Vdis; In the data writing stage, the first light emitting control unit, the compensation unit and the second light emitting control unit are turned off, the data writing unit and the first reset unit and the second reset unit are turned on, data is written, the first PMOS transistor, the fourth PMOS transistor and the fifth PMOS transistor are turned off, the second PMOS transistor, the third PMOS transistor and the sixth PMOS transistor are turned on, and data is written to point S. In this stage, the voltage at point S is: V s =Vdata, V g =Vinit; In the threshold voltage compensation stage, the first light-emitting control unit, the second light-emitting control unit, the first reset unit and the second reset unit are turned off, the data writing unit and the compensation unit are turned on, the first PMOS transistor, the third PMOS transistor, the fifth PMOS transistor and the sixth PMOS transistor are turned off, the second PMOS transistor and the fourth PMOS transistor are turned on, and a current is written to the g point through the driving transistor until Vdata-V g =a*(VDD-Vdata)+|Vth|, where a is the offset coefficient; In the light emitting stage, the first light emitting control unit and the second light emitting control unit are turned on, and the data writing unit, the compensation unit and the first reset unit and the second reset unit are turned off. Ioled=β*(V sg -|Vth|) 2 =β*a 2 *(VDD-Vdata )2 。 6. A driving method for a pixel circuit according to claim 3, characterized in that: Includes steps: In the initialization and data writing stage, the first light-emitting control unit and the second light-emitting control unit are turned off, the data writing unit, the compensation unit and the first reset unit are turned on, the energy storage unit is initialized and data is written, the first PMOS transistor and the fifth PMOS transistor are turned off; the second PMOS transistor, the third PMOS transistor and the fourth PMOS transistor are turned on, and the voltage at point S is: V s =Vdata, g point voltage V g =Vinit; In the threshold voltage Vth compensation stage, the first light-emitting control unit, the second light-emitting control unit and the first reset unit are turned off, the data writing unit and the compensation unit are turned on, data is written, the first PMOS transistor, the third PMOS transistor and the fifth PMOS transistor are turned off, the second PMOS transistor and the fourth PMOS transistor are turned on, and the data DATA is written to the S point. In this stage, the voltage at the S point is: V s =Vdata, g point voltage V g = Vinit, current flows through the drive transistor TD and writes to point g until Vdata-V g =a*(VDD-Vdata)+|Vth|, where a is the offset coefficient; In the anode initialization stage, the first light-emitting control unit, the data writing unit and the compensation unit are turned off, the first reset unit and the second light-emitting control unit are turned on, the first PMOS transistor, the second PMOS transistor and the fourth PMOS transistor are turned off, the third PMOS transistor and the fifth PMOS transistor are turned on, and the anode voltage of the light-emitting unit Voled=Vinit; In the light-emitting stage, the first reset unit, the data writing unit, and the compensation unit are turned off, the first light-emitting control unit and the second light-emitting control unit are turned on, the third PMOS transistor, the second PMOS transistor, and the fourth PMOS transistor are turned off, the first PMOS transistor and the fifth PMOS transistor are turned on, and the voltage difference V between the S point and the g point is sg , Ioled=β*(V sg -|Vth|) 2 =β*a 2 *(VDD-Vdata) 2 。 7. A driving method for a pixel circuit according to claim 4, characterized in that: Includes steps: In the anode initialization stage, the first light emitting control unit and the data writing unit are turned off, the compensation unit, the second light emitting control unit and the first reset unit are turned on, the first PMOS transistor and the second PMOS transistor are turned off, and the third PMOS transistor, the fourth PMOS transistor and the fifth PMOS transistor are turned on; In the data writing stage, the first light emitting control unit, the second light emitting control unit and the compensation unit are turned off, the data writing unit and the first reset unit are turned on, the data is written into the source of the driving transistor, the first PMOS transistor, the fourth PMOS transistor and the fifth PMOS transistor are turned off, the second PMOS transistor and the third PMOS transistor are turned on, and Vdata is written into the source of the driving transistor; In the threshold voltage Vth compensation stage, the first light-emitting control unit, the first reset unit, and the second light-emitting control unit are turned off, the data writing unit and the compensation unit are turned on, the first PMOS transistor, the third PMOS transistor, and the fifth PMOS transistor are turned off, the second PMOS transistor and the fourth PMOS transistor are turned on, and current is written to the g point through the driving transistor until Vdata-V g =a*(VDD-Vdata)+|Vth|, where a is the offset coefficient; In the light-emitting stage, the first reset unit, the data writing unit, and the compensation unit are turned off, the first light-emitting control unit and the second light-emitting control unit are turned on, the first PMOS transistor, the third PMOS transistor, and the fifth PMOS transistor are turned off, the second PMOS transistor and the fourth PMOS transistor are turned on, and a current is written to the g point through the driving transistor, Ioled = β*(V sg -|Vth|) 2 =β*a 2 *(VDD-Vdata) 2 .

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