WO2018068391A1 - Amoled像素驱动电路及驱动方法 - Google Patents

Amoled像素驱动电路及驱动方法 Download PDF

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WO2018068391A1
WO2018068391A1 PCT/CN2016/110900 CN2016110900W WO2018068391A1 WO 2018068391 A1 WO2018068391 A1 WO 2018068391A1 CN 2016110900 W CN2016110900 W CN 2016110900W WO 2018068391 A1 WO2018068391 A1 WO 2018068391A1
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thin film
film transistor
scan signal
electrically connected
gate
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English (en)
French (fr)
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聂诚磊
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TCL China Star Optoelectronics Technology Co Ltd
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Shenzhen China Star Optoelectronics Technology Co Ltd
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Priority to US15/506,246 priority Critical patent/US10056037B1/en
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    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
    • G09G3/30—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels
    • G09G3/32—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED]
    • G09G3/3208—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED]
    • G09G3/3225—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED] using an active matrix
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    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
    • G09G3/30—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels
    • G09G3/32—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED]
    • G09G3/3208—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED]
    • G09G3/3225—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED] using an active matrix
    • G09G3/3233—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED] using an active matrix with pixel circuitry controlling the current through the light-emitting element
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    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
    • G09G3/30—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels
    • G09G3/32—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED]
    • G09G3/3208—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED]
    • G09G3/3225—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED] using an active matrix
    • G09G3/3258—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED] using an active matrix with pixel circuitry controlling the voltage across the light-emitting element
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/10—OLED displays
    • H10K59/12—Active-matrix OLED [AMOLED] displays
    • H10K59/121—Active-matrix OLED [AMOLED] displays characterised by the geometry or disposition of pixel elements
    • H10K59/1213—Active-matrix OLED [AMOLED] displays characterised by the geometry or disposition of pixel elements the pixel elements being TFTs
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/10—OLED displays
    • H10K59/12—Active-matrix OLED [AMOLED] displays
    • H10K59/121—Active-matrix OLED [AMOLED] displays characterised by the geometry or disposition of pixel elements
    • H10K59/1216—Active-matrix OLED [AMOLED] displays characterised by the geometry or disposition of pixel elements the pixel elements being capacitors
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/10—OLED displays
    • H10K59/12—Active-matrix OLED [AMOLED] displays
    • H10K59/123—Connection of the pixel electrodes to the thin film transistors [TFT]
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    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2300/00—Aspects of the constitution of display devices
    • G09G2300/04—Structural and physical details of display devices
    • G09G2300/0421—Structural details of the set of electrodes
    • G09G2300/0426—Layout of electrodes and connections
    • G—PHYSICS
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    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2300/00—Aspects of the constitution of display devices
    • G09G2300/08—Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements
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    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2300/00—Aspects of the constitution of display devices
    • G09G2300/08—Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements
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    • G09G2300/0819—Several active elements per pixel in active matrix panels used for counteracting undesired variations, e.g. feedback or autozeroing
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    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
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    • G09G2300/0861—Several active elements per pixel in active matrix panels forming a memory circuit, e.g. a dynamic memory with one capacitor with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes
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    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
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    • G09G2310/02—Addressing, scanning or driving the display screen or processing steps related thereto
    • G09G2310/0243—Details of the generation of driving signals
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    • G09G2320/043—Preventing or counteracting the effects of ageing

Definitions

  • the present invention relates to the field of display technologies, and in particular, to an AMOLED pixel driving circuit and a driving method.
  • OLED Organic Light Emitting Display
  • OLED Organic Light Emitting Display
  • the OLED display device can be divided into two types: passive matrix OLED (PMOLED) and active matrix OLED (AMOLED), namely direct addressing and thin film transistor (Thin Film Transistor, according to the driving method). TFT) matrix addressing two types.
  • the AMOLED has pixels arranged in an array, belongs to an active display type, has high luminous efficiency, and is generally used as a high-definition large-sized display device.
  • the AMOLED is a current driving device. When a current flows through the organic light emitting diode, the organic light emitting diode emits light, and the luminance of the light is determined by the current flowing through the organic light emitting diode itself. Most existing integrated circuits (ICs) only transmit voltage signals, so the pixel driving circuit of AMOLED needs to complete the task of converting a voltage signal into a current signal.
  • ICs integrated circuits
  • the conventional AMOLED pixel driving circuit is usually 2T1C, that is, two thin film transistors plus a capacitor structure, which converts a voltage into a current, wherein one thin film transistor is a switching thin film transistor for controlling the entry of a data signal, and the other thin film transistor is driven.
  • Thin film transistor for controlling the current through the organic light emitting diode so the importance of driving the threshold voltage of the thin film transistor is very obvious, and the positive or negative drift of the threshold voltage causes different currents to pass under the same data signal.
  • Organic light emitting diodes are used.
  • thin film transistors made of low-temperature polysilicon or oxide semiconductors have threshold voltage drift phenomenon during use due to factors such as illumination, source and drain electrode voltage stress.
  • the threshold voltage drift of the driving thin film transistor cannot be improved by adjustment. Therefore, it is necessary to reduce the influence of the threshold voltage drift by adding a new thin film transistor or a new signal, that is, the AMOLED pixel driving circuit has Compensation function.
  • An object of the present invention is to provide an AMOLED pixel driving circuit, which can reduce the threshold voltage drift of the driving thin film transistor by adjusting the size of the data signal, can effectively compensate the threshold voltage of the driving thin film transistor, and stabilize the current flowing through the organic light emitting diode.
  • the illumination brightness of the organic light emitting diode is ensured to be uniform, and the display effect of the picture is improved.
  • the object of the present invention is to provide an AMOLED pixel driving method capable of effectively compensating the threshold voltage of a driving thin film transistor, solving the problem of unstable current flowing through the organic light emitting diode caused by threshold voltage drift, and making the organic light emitting diode The brightness of the light is uniform, which improves the display of the picture.
  • the present invention provides an AMOLED pixel driving circuit, including: a first thin film transistor, a second thin film transistor, a third thin film transistor, a fourth thin film transistor, a fifth thin film transistor, a sixth thin film transistor, a capacitor, And organic light emitting diodes;
  • the first thin film transistor is a double gate thin film transistor, the bottom gate is connected to a preset voltage, the top gate is electrically connected to the first node, the source is electrically connected to the second node, and the drain is connected to the power supply voltage;
  • the second thin film transistor is a double gate thin film transistor and has a mirror image relationship with the first thin film transistor.
  • the bottom gate is electrically connected to the drain of the sixth thin film transistor, and the top gate and the drain are electrically connected to the first node.
  • the source is electrically connected to the second node;
  • the gate of the third thin film transistor is connected to the first scan signal, the source is connected to the power supply voltage, and the drain is electrically connected to the first node;
  • the gate of the fourth thin film transistor is connected to the second scan signal, the source is electrically connected to the data signal, and the drain is electrically connected to the second node;
  • the gate of the fifth thin film transistor is connected to the third scan signal, the source is electrically connected to the second node, and the drain is electrically connected to the anode of the organic light emitting diode;
  • the gate of the sixth thin film transistor is connected to the second scan signal, the source is connected to the preset voltage, and the drain is electrically connected to the bottom gate of the second thin film transistor;
  • One end of the capacitor is electrically connected to the first node, and the other end is grounded;
  • the anode of the organic light emitting diode is electrically connected to the second node, and the cathode is grounded;
  • the double gate first thin film transistor is used to drive the organic light emitting diode
  • the fourth film Transistors are used to control the entry of data signals.
  • the first thin film transistor, the second thin film transistor, the third thin film transistor, the fourth thin film transistor, the fifth thin film transistor, and the sixth thin film transistor are all low temperature polysilicon thin film transistors, oxide semiconductor thin film transistors, or amorphous silicon thin films Transistor.
  • the first scan signal, the second scan signal, and the third scan signal are all provided by an external timing controller.
  • the preset voltage is a constant voltage.
  • the first scan signal, the second scan signal, the third scan signal, and the data signal are combined to sequentially correspond to a precharge phase, a threshold voltage programming phase, and a driving illumination phase;
  • the first scan signal provides a high potential
  • the second scan signal, the third scan signal, and the data signal each provide a low potential
  • the first scan signal provides a low potential
  • the second scan signal, the third scan signal, and the data signal each provide a high potential
  • the first scan signal, the second scan signal, and the data signal each provide a low potential
  • the third scan signal provides a high potential
  • the invention also provides an AMOLED pixel driving method, comprising the following steps:
  • Step 1 Providing an AMOLED pixel driving circuit
  • the AMOLED pixel driving circuit includes: a first thin film transistor, a second thin film transistor, a third thin film transistor, a fourth thin film transistor, a fifth thin film transistor, a sixth thin film transistor, a capacitor, and an organic light emitting diode;
  • the first thin film transistor is a double gate thin film transistor, the bottom gate is connected to a preset voltage, the top gate is electrically connected to the first node, the source is electrically connected to the second node, and the drain is connected to the power supply voltage;
  • the second thin film transistor is a double gate thin film transistor and has a mirror image relationship with the first thin film transistor.
  • the bottom gate is electrically connected to the drain of the sixth thin film transistor, and the top gate and the drain are electrically connected to the first node.
  • the source is electrically connected to the second node;
  • the gate of the third thin film transistor is connected to the first scan signal, the source is connected to the power supply voltage, and the drain is electrically connected to the first node;
  • the gate of the fourth thin film transistor is connected to the second scan signal, the source is electrically connected to the data signal, and the drain is electrically connected to the second node;
  • the gate of the fifth thin film transistor is connected to the third scan signal, the source is electrically connected to the second node, and the drain is electrically connected to the anode of the organic light emitting diode;
  • the gate of the sixth thin film transistor is connected to the second scan signal, the source is connected to the preset voltage, and the drain is electrically connected to the bottom gate of the second thin film transistor;
  • One end of the capacitor is electrically connected to the first node, and the other end is grounded;
  • the anode of the organic light emitting diode is electrically connected to the second node, and the cathode is grounded;
  • the first thin film transistor of the double gate is used for driving the organic light emitting diode
  • the fourth thin film transistor is used for controlling the entry of the data signal
  • Step 2 entering the pre-charging stage
  • the first scan signal provides a high potential, the third thin film transistor is turned on, the capacitor is charged; the second scan signal provides a low potential, the fourth and sixth thin film transistors are turned off; the third scan signal provides a low potential, and the fifth thin film transistor is turned off.
  • the drain of the second thin film transistor and the top gate, and the top gate of the first thin film transistor are written with a power supply voltage, the bottom gate of the first thin film transistor is written with a preset voltage; and the data signal provides a low potential;
  • Step 3 Enter a threshold voltage programming stage
  • the first scan signal provides a low potential, the third thin film transistor is turned off; the second scan signal provides a high potential, the fourth and sixth thin film transistors are turned on; the third scan signal provides a high potential, and the fifth thin film transistor is turned on;
  • the bottom gate of the second thin film transistor is written with a predetermined voltage, the source of the first thin film transistor and the source of the second thin film transistor write a high potential provided by the data signal, and the bottom gate of the first thin film transistor maintains a preset voltage;
  • the two thin film transistors are turned on, the voltages of the top gate and the drain of the second thin film transistor, and the voltage of the top gate of the first thin film transistor are continuously decreased with time, and the threshold voltages of the first thin film transistor and the second thin film transistor are continuously rising.
  • Vth is a threshold voltage of the first thin film transistor and the second thin film transistor
  • Vpre is a preset voltage
  • Vdata is a high potential provided by the data signal
  • Step 4 entering the driving lighting stage
  • the bottom gate of a thin film transistor maintains a preset voltage, the first thin film transistor is turned on, the source voltage of the first thin film transistor is converted to the voltage of the anode of the organic light emitting diode, the organic light emitting diode emits light, and the current flowing through the organic light emitting diode
  • the threshold voltage of the first thin film transistor is independent.
  • the first thin film transistor, the second thin film transistor, the third thin film transistor, the fourth thin film transistor, the fifth thin film transistor, and the sixth thin film transistor are all low temperature polysilicon thin film transistors, oxide semiconductor thin film transistors, or amorphous silicon thin films Transistor.
  • the first scan signal, the second scan signal, and the third scan signal all pass external timing Controller provided.
  • the preset voltage is a constant voltage.
  • the present invention also provides an AMOLED pixel driving circuit, comprising: a first thin film transistor, a second thin film transistor, a third thin film transistor, a fourth thin film transistor, a fifth thin film transistor, a sixth thin film transistor, a capacitor, and an organic light emitting diode;
  • the first thin film transistor is a double gate thin film transistor, the bottom gate is connected to a preset voltage, the top gate is electrically connected to the first node, the source is electrically connected to the second node, and the drain is connected to the power supply voltage;
  • the second thin film transistor is a double gate thin film transistor and has a mirror image relationship with the first thin film transistor.
  • the bottom gate is electrically connected to the drain of the sixth thin film transistor, and the top gate and the drain are electrically connected to the first node.
  • the source is electrically connected to the second node;
  • the gate of the third thin film transistor is connected to the first scan signal, the source is connected to the power supply voltage, and the drain is electrically connected to the first node;
  • the gate of the fourth thin film transistor is connected to the second scan signal, the source is electrically connected to the data signal, and the drain is electrically connected to the second node;
  • the gate of the fifth thin film transistor is connected to the third scan signal, the source is electrically connected to the second node, and the drain is electrically connected to the anode of the organic light emitting diode;
  • the gate of the sixth thin film transistor is connected to the second scan signal, the source is connected to the preset voltage, and the drain is electrically connected to the bottom gate of the second thin film transistor;
  • One end of the capacitor is electrically connected to the first node, and the other end is grounded;
  • the anode of the organic light emitting diode is electrically connected to the second node, and the cathode is grounded;
  • the first thin film transistor of the double gate is used for driving the organic light emitting diode
  • the fourth thin film transistor is used for controlling the entry of the data signal
  • the first thin film transistor, the second thin film transistor, the third thin film transistor, the fourth thin film transistor, the fifth thin film transistor, and the sixth thin film transistor are all low temperature polysilicon thin film transistors, oxide semiconductor thin film transistors, or amorphous Silicon thin film transistor;
  • the first scan signal, the second scan signal, and the third scan signal are all provided by an external timing controller.
  • the preset voltage controls the opening of the first thin film transistor, causing the organic light emitting diode to emit light, and the current flowing through the organic light emitting diode is independent of the threshold voltage of the first thin film transistor, thereby ensuring organic light emission
  • the brightness of the diode is uniform, which improves the display effect of the picture.
  • the voltage and illumination stress of the double-gate thin film crystal have less influence on the threshold voltage, and the threshold voltage of the double-gate thin film transistor is negatively correlated with the top gate voltage.
  • the dual gate thin film crystal is used as a driving thin film transistor, and the threshold voltage of the driving transistor can be specified by inputting a preset voltage without reducing the threshold voltage drift of the driving thin film transistor by adjusting the magnitude of the data signal.
  • the invention provides an AMOLED pixel driving method, which can effectively compensate the threshold voltage of the driving thin film transistor, solve the problem that the current flowing through the organic light emitting diode is unstable due to the threshold voltage drift, and make the light emitting brightness of the organic light emitting diode uniform. Improve the display of the screen.
  • FIG. 1 is a circuit diagram of an AMOLED pixel driving circuit of the present invention
  • FIG. 2 is a timing diagram of an AMOLED pixel driving circuit of the present invention
  • step 2 of the AMOLED pixel driving method of the present invention is a schematic diagram of step 2 of the AMOLED pixel driving method of the present invention.
  • step 3 of the AMOLED pixel driving method of the present invention is a schematic diagram of step 3 of the AMOLED pixel driving method of the present invention.
  • FIG. 5 is a schematic diagram of step 4 of the AMOLED pixel driving method of the present invention.
  • the present invention provides a 6T1C structure AMOLED pixel driving circuit, comprising: a first thin film transistor T1, a second thin film transistor T2, a third thin film transistor T3, a fourth thin film transistor T4, and a fifth thin film.
  • the first thin film transistor T1 is a double gate thin film transistor, the bottom gate BG1 is connected to the preset voltage Vpre, the top gate TG1 is electrically connected to the first node A, the source is electrically connected to the second node B, and the drain is connected.
  • dual gate thin film transistors The characteristic is that the influence of voltage and illumination stress on its threshold voltage is small, and its threshold voltage has a negative correlation with the top gate voltage, that is, the larger the top gate voltage, the smaller the threshold voltage.
  • the second thin film transistor T2 is a double gate thin film transistor and has a mirror image relationship with the first thin film transistor T1.
  • the bottom gate BG2 is electrically connected to the drain of the sixth thin film transistor T6, and the top gate TG2 and the drain are electrically connected.
  • the first node A is connected, and the source is electrically connected to the second node B. Since the first thin film transistor T1 and the second thin film transistor T2 are in a mirror image relationship, the two have the same threshold voltage when the top gate voltage is the same.
  • the gate of the third thin film transistor T3 is connected to the first scan signal Scan1, the source is connected to the power supply voltage VDD, and the drain is electrically connected to the first node A.
  • the gate of the fourth thin film transistor T4 is connected to the second scan signal Scan2, the source is electrically connected to the data signal Data, and the drain is electrically connected to the second node B.
  • the fourth thin film transistor T4 is used to control the entry of the data signal Data.
  • the gate of the fifth thin film transistor T5 is connected to the third scan signal Scan3, the source is electrically connected to the second node B, and the drain is electrically connected to the anode of the organic light emitting diode D1.
  • the gate of the sixth thin film transistor T6 is connected to the second scan signal Scan2, the source is connected to the preset voltage Vpre, and the drain is electrically connected to the bottom gate BG2 of the second thin film transistor T2.
  • One end of the capacitor C1 is electrically connected to the first node A, and the other end is grounded.
  • the anode of the organic light emitting diode D1 is electrically connected to the second node B, and the cathode is grounded.
  • the first thin film transistor T1, the second thin film transistor T2, the third thin film transistor T3, the fourth thin film transistor T4, the fifth thin film transistor T5, and the sixth thin film transistor T6 are all low temperature polysilicon thin film transistors and oxides.
  • the first scan signal Scan1, the second scan signal Scan2, and the third scan signal Scan3 are all provided by an external timing controller.
  • the preset voltage Vpre is a constant voltage.
  • the first scan signal Scan1, the second scan signal Scan2, the third scan signal Scan3, and the data signal Data are combined to sequentially correspond to a precharge phase 1 and a threshold voltage programming phase 2 And a driving illumination stage 3.
  • the first scan signal Scan1 provides a high potential
  • the second scan signal Scan2, the third scan signal Scan3, and the data signal Data both provide a low potential
  • the threshold voltage programming phase 2 The first scan signal Scan1 provides a low potential
  • the second scan signal Scan2, the third scan signal Scan3, and the data signal Data each provide a high potential
  • the driving illumination phase 3 the first scan signal Scan1
  • the second scan signal Scan2 and the data signal Data each provide a low potential
  • the third scan signal Scan3 provides a high potential.
  • the working process of the AMOLED pixel driving circuit of the present invention is as follows:
  • the first scan signal Scan1 provides a high potential
  • the third thin film transistor T3 is turned on, the capacitor C1 is charged
  • the second scan signal Scan2 provides a low potential
  • the fourth and sixth thin film transistors T4, T6 are turned off
  • the third scan signal Scan3 provides a low potential
  • the fifth thin film transistor T5 is turned off
  • the power supply voltage VDD is written to the top of the top gate TG1 and the second thin film transistor T2 of the first thin film transistor T1 via the turned-on third thin film transistor T3.
  • the gate TG2 and the drain, the bottom gate BG1 of the first thin film transistor T1 is written with a preset voltage Vpre; the data signal Data provides a low potential;
  • the first scan signal Scan1 provides a low potential
  • the third thin film transistor T3 is turned off
  • the second scan signal Scan2 provides a high potential
  • the fourth and sixth thin film transistors T4, T6 are turned on
  • the third scan signal Scan3 provides a high potential
  • the fifth thin film transistor T5 is turned on
  • the preset voltage Vpre is written into the bottom gate BG2 of the second thin film transistor T2 through the opened sixth thin film transistor T6, the source and the second of the first thin film transistor T1.
  • the source of the thin film transistor T2 writes a high potential provided by the data signal Data, and the bottom gate BG1 of the first thin film transistor T1 maintains a preset voltage Vpre; since the threshold voltage of the double gate thin film transistor is negatively correlated with the top gate voltage, at this time
  • the threshold voltage values of a thin film transistor T1 and the second thin film transistor T2 are very small, and both the first thin film transistor T1 and the second thin film transistor T2 are turned on; as time passes and the capacitor C1 is discharged, the top gate TG2 of the second thin film transistor T2 is The voltage of the drain and the voltage of the top gate TG1 of the first thin film transistor T1 are continuously decreased, and the threshold voltages of the first thin film transistor T1 and the second thin film transistor T2 are continuously increased.
  • V BG the bottom of the first thin film transistor T1 and the second thin film transistor T2
  • Vs the source voltage of the first thin film transistor T1 and the second thin film transistor T2
  • Vth the threshold voltage of the first thin film transistor T1 and the second thin film transistor T2
  • Vdata is the high potential provided by the data signal Data
  • the double-gate thin film crystal Since the voltage and illumination stress of the double-gate thin film crystal have less influence on its threshold voltage, and the threshold voltage of the double-gate thin film transistor is negatively correlated with the top gate voltage, the double-gate thin film crystal is used as a driving.
  • the thin film transistor can specify the threshold voltage of the driving transistor by inputting the preset voltage Vpre without reducing the threshold voltage of the driving thin film transistor by adjusting the size of the data signal Data Shift;
  • the first scan signal Scan1 provides a low potential
  • the third thin film transistor T3 remains off
  • the second scan signal Scan2 provides a low potential
  • the fourth and sixth thin film transistors T4, T6 are turned off
  • the third scan signal Scan3 provides a high potential
  • the fifth thin film transistor T5 remains open
  • the voltage values of the top gate TG1 of the first thin film transistor T1 and the top gate TG2 of the second thin film transistor T2 are maintained by the storage of the capacitor C1.
  • ⁇ is a constant coefficient related to the characteristics of the thin film transistor.
  • the current value flowing through the first thin film transistor T1 and the organic light emitting diode D1 is independent of the threshold voltage Vth of the first thin film transistor T1, compensating for the threshold voltage drift of the driving thin film transistor, and solving the flow of organic light caused by the threshold voltage drift.
  • the problem that the current of the diode is unstable can make the luminance of the organic light emitting diode uniform and improve the display effect of the screen.
  • the present invention further provides an AMOLED pixel driving method, comprising the following steps:
  • Step 1 Provide an AMOLED pixel driving circuit.
  • the AMOLED pixel driving circuit includes: a first thin film transistor T1, a second thin film transistor T2, a third thin film transistor T3, a fourth thin film transistor T4, a fifth thin film transistor T5, a sixth thin film transistor T6, a capacitor C1, and an organic light emitting layer. Diode D1.
  • the characteristics of the dual-gate thin film transistor are that the voltage and the light stress have little influence on the threshold voltage, and the threshold voltage has a negative correlation with the top gate voltage, that is, the larger the top gate voltage, the smaller the threshold voltage.
  • the first thin film transistor T1 is a double gate thin film transistor, the bottom gate BG1 is connected to the preset voltage Vpre, the top gate TG1 is electrically connected to the first node A, the source is electrically connected to the second node B, and the drain is connected.
  • the power supply voltage VDD; the double-gate first thin film transistor T1 functions as a driving thin film transistor for driving the organic light emitting diode D1.
  • the second thin film transistor T2 is a double gate thin film transistor and has a mirror image relationship with the first thin film transistor T1.
  • the bottom gate BG2 is electrically connected to the drain of the sixth thin film transistor T6, and the top gate TG2 and the drain are electrically connected.
  • the first node A is connected, and the source is electrically connected to the second node B. Since the first thin film transistor T1 and the second thin film transistor T2 are in a mirror image relationship, the two have the same threshold voltage when the top gate voltage is the same.
  • the gate of the third thin film transistor T3 is connected to the first scan signal Scan1, the source is connected to the power supply voltage VDD, and the drain is electrically connected to the first node A.
  • the gate of the fourth thin film transistor T4 is connected to the second scan signal Scan2, the source is electrically connected to the data signal Data, and the drain is electrically connected to the second node B.
  • the fourth thin film transistor T4 is used to control the entry of the data signal Data.
  • the gate of the fifth thin film transistor T5 is connected to the third scan signal Scan3, the source is electrically connected to the second node B, and the drain is electrically connected to the anode of the organic light emitting diode D1.
  • the gate of the sixth thin film transistor T6 is connected to the second scan signal Scan2, the source is connected to the preset voltage Vpre, and the drain is electrically connected to the bottom gate BG2 of the second thin film transistor T2.
  • One end of the capacitor C1 is electrically connected to the first node A, and the other end is grounded.
  • the anode of the organic light emitting diode D1 is electrically connected to the second node B, and the cathode is grounded.
  • the first thin film transistor T1, the second thin film transistor T2, the third thin film transistor T3, the fourth thin film transistor T4, the fifth thin film transistor T5, and the sixth thin film transistor T6 are all low temperature polysilicon thin film transistors and oxides.
  • the first scan signal Scan1, the second scan signal Scan2, and the third scan signal Scan3 are all provided by an external timing controller.
  • the preset voltage Vpre is a constant voltage.
  • Step 2 Enter pre-charge phase 1.
  • the first scan signal Scan1 provides a high potential
  • the third thin film transistor T3 is turned on, the capacitor C1 is charged
  • the second scan signal Scan2 provides a low potential
  • the fourth and sixth thin film transistors T4, T6 are turned off, and the third scan signal Scan3 is provided.
  • Low potential the fifth thin film transistor T5 is turned off; the power supply voltage VDD is written into the top gate TG1 of the first thin film transistor T1 and the top gate TG2 and the drain of the second thin film transistor T2 via the turned-on third thin film transistor T3.
  • the bottom gate BG1 of the first thin film transistor T1 is written with a preset voltage Vpre; the data signal Data provides a low potential.
  • Step 3 Enter the threshold voltage programming phase 2.
  • the first scan signal Scan1 provides a low potential, the third thin film transistor T3 is turned off; the second scan signal Scan2 provides a high potential, the fourth and sixth thin film transistors T4, T6 are turned on; and the third scan signal Scan3 provides a high potential
  • the fifth thin film transistor T5 is turned on; the preset voltage Vpre is written into the bottom gate BG2 of the second thin film transistor T2 through the turned-on sixth thin film transistor T6, and the high potential provided by the data signal Data is written by the turned-on fourth thin film transistor T4.
  • the bottom gate BG1 of the first thin film transistor T1 maintains a preset voltage Vpre; since the threshold voltage of the double gate thin film transistor is negatively correlated with the top gate voltage, At this time, the threshold voltage values of the first thin film transistor T1 and the second thin film transistor T2 are very small, and both the first thin film transistor T1 and the second thin film transistor T2 are turned on; and the capacitor C1 is discharged over time, and the top of the second thin film transistor T2 is turned on.
  • Vth Vpre-Vdata, V BG
  • Vs the source voltage of the first thin film transistor T1 and the second thin film transistor T2
  • Vth the threshold voltage of the first thin film transistor T1 and the second thin film transistor T2
  • Vdata the high potential provided by the data signal Data
  • the threshold voltage of the driving transistor can be specified by inputting the preset voltage Vpre without reducing the threshold voltage drift of the driving thin film transistor by adjusting the magnitude of the data signal Data.
  • Step 4 Enter the driving lighting stage 3.
  • the first scan signal Scan1 provides a low potential, the third thin film transistor T3 remains off; the second scan signal Scan2 provides a low potential, and the fourth and sixth thin film transistors T4, T6 are turned off; the third scan signal Scan3 Providing a high potential, the fifth thin film transistor T5 remains open; the voltage values of the top gate TG1 of the first thin film transistor T1 and the top gate TG2 of the second thin film transistor T2 remain unchanged under the storage of the capacitor C1, maintaining the first
  • the voltage of the anode V OLED the organic light emitting diode D1 emits light.
  • ⁇ is a constant coefficient related to the characteristics of the thin film transistor.
  • the current value flowing through the first thin film transistor T1 and the organic light emitting diode D1 is independent of the threshold voltage Vth of the first thin film transistor T1, compensating for the threshold voltage drift of the driving thin film transistor, and solving the flow of organic light caused by the threshold voltage drift.
  • the problem that the current of the diode is unstable can make the luminance of the organic light emitting diode uniform and improve the display effect of the screen.
  • the AMOLED pixel driving circuit of the present invention uses a dual-gate thin film transistor as a driving thin film transistor, and controls the opening of the third thin film transistor by the first scanning signal in the pre-charging stage, so that the first thin film transistor is driven by the thin film transistor.
  • the dual-gate thin film crystal is used as the driving thin film transistor, and the preset voltage can be input.
  • the AMOLED pixel driving method of the present invention can effectively compensate the threshold voltage of the driving thin film transistor, solve the problem that the current flowing through the organic light emitting diode is unstable due to the threshold voltage drift, and make the brightness of the organic light emitting diode uniform, and improve the picture.
  • the display effect is referred to specify the threshold voltage of the drive transistor without weakening by adjusting the size of the data signal.

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Abstract

一种AMOLED像素驱动电路及驱动方法。AMOLED像素驱动电路为6T1C结构，包括作为驱动薄膜晶体管的双栅极的第一薄膜晶体管(T1)、与第一薄膜晶体管(T1)呈镜像关系的第二薄膜晶体管(T2)、第三薄膜晶体管(T3)、第四薄膜晶体管(T4)、第五薄膜晶体管(T5)、第六薄膜晶体管(T6)、电容(C1)、及有机发光二极管(D1)，接入第一扫描信号(Scan1)、第二扫描信号(Scan2)、第三扫描信号(Scan3)、数据信号(Data)、及预设电压(Vpre)，该电路能够有效补偿驱动薄膜晶体管的阈值电压，解决由阈值电压漂移导致的流过有机发光二极管的电流不稳定的问题；另外，将双栅极薄膜晶体管用作驱动薄膜晶体管，能够通过输入预设电压(Vpre)来指定驱动晶体管的阈值电压。

Description

AMOLED像素驱动电路及驱动方法 技术领域
本发明涉及显示技术领域，尤其涉及一种AMOLED像素驱动电路及驱动方法。
背景技术
有机发光二极管(Organic Light Emitting Display，OLED)显示装置具有自发光、驱动电压低、发光效率高、响应时间短、清晰度与对比度高、近180°视角、使用温度范围宽，可实现柔性显示与大面积全色显示等诸多优点，被业界公认为是最有发展潜力的显示装置。
OLED显示装置按照驱动方式可以分为无源矩阵型OLED(Passive Matrix OLED，PMOLED)和有源矩阵型OLED(Active Matrix OLED，AMOLED)两大类，即直接寻址和薄膜晶体管(Thin Film Transistor，TFT)矩阵寻址两类。其中，AMOLED具有呈阵列式排布的像素，属于主动显示类型，发光效能高，通常用作高清晰度的大尺寸显示装置。
AMOLED是电流驱动器件，当有电流流过有机发光二极管时，有机发光二极管发光，且发光亮度由流过有机发光二极管自身的电流决定。大部分已有的集成电路(Integrated Circuit，IC)都只传输电压信号，故AMOLED的像素驱动电路需要完成将电压信号转变为电流信号的任务。
传统的AMOLED像素驱动电路通常为2T1C，即两个薄膜晶体管加一个电容的结构，将电压转换为电流，其中一个薄膜晶体管为开关薄膜晶体管，用于控制数据信号的进入，另一个薄膜晶体管为驱动薄膜晶体管，用于控制通过有机发光二极管的电流，因此驱动薄膜晶体管的阈值电压的重要性便十分明显，阈值电压的正向或负向漂移都有会使得在相同数据信号下有不同的电流通过有机发光二极管。然而，目前由低温多晶硅或氧化物半导体制作的薄膜晶体管因光照、源漏电极电压应力作用等因素，在使用过程中均会发生阈值电压漂移现象。传统的2T1C电路中，驱动薄膜晶体管的阈值电压漂移无法通过调节得到改善，因此需要通过添加新的薄膜晶体管或新的信号的方式来减弱阈值电压漂移带来的影响，即使得AMOLED像素驱动电路具有补偿功能。
现有技术中不乏使用传统单栅极薄膜晶体管作为驱动薄膜晶体管的AMOLED像素补偿电路，通过探测驱动薄膜晶体管的阈值电压，然后根据 阈值电压的漂移程度调整所需输入的数据信号值的大小。这种电路的缺点在于传统单栅极薄膜晶体管在受到电压、光照等应力作用后，阈值电压通常向正向漂移而增大，因此数据信号也要相应增大，以减弱驱动薄膜晶体管阈值电压漂移的影响，而数据信号的增大又进一步加剧了对驱动薄膜晶体管的电压应力，加快了阈值电压漂移，形成恶性循环。
发明内容
本发明的目的在于提供一种AMOLED像素驱动电路，无需通过调整数据信号的大小来减弱驱动薄膜晶体管的阈值电压漂移，能够有效补偿驱动薄膜晶体管的阈值电压，使流过有机发光二极管的电流稳定，保证有机发光二极管的发光亮度均匀，改善画面的显示效果。
本发明的目的还在于提供一种AMOLED像素驱动方法，能够对驱动薄膜晶体管的阈值电压进行有效补偿，解决由阈值电压漂移导致的流过有机发光二极管的电流不稳定的问题，使有机发光二极管的发光亮度均匀，改善画面的显示效果。
为实现上述目的，本发明提供了一种AMOLED像素驱动电路，包括：第一薄膜晶体管、第二薄膜晶体管、第三薄膜晶体管、第四薄膜晶体管、第五薄膜晶体管、第六薄膜晶体管、电容、及有机发光二极管；
所述第一薄膜晶体管为双栅极薄膜晶体管，其底栅接入预设电压，顶栅电性连接第一节点，源极电性连接第二节点，漏极接入电源电压；
所述第二薄膜晶体管为双栅极薄膜晶体管，并与第一薄膜晶体管呈镜像关系，其底栅电性连接第六薄膜晶体管的漏极，顶栅及漏极均电性连接第一节点，源极电性连接第二节点；
所述第三薄膜晶体管的栅极接入第一扫描信号，源极接入电源电压，漏极电性连接第一节点；
所述第四薄膜晶体管的栅极接入第二扫描信号，源极电性连接数据信号，漏极电性连接第二节点；
所述第五薄膜晶体管的栅极接入第三扫描信号，源极电性连接第二节点，漏极电性连接有机发光二极管的阳极；
所述第六薄膜晶体管的栅极接入第二扫描信号，源极接入预设电压，漏极电性连接第二薄膜晶体管的底栅；
所述电容的一端电性连接第一节点，另一端接地；
所述有机发光二极管的阳极电性连接第二节点，阴极接地；
其中，双栅极的第一薄膜晶体管用于驱动有机发光二极管，第四薄膜 晶体管用于控制数据信号的进入。
所述第一薄膜晶体管、第二薄膜晶体管、第三薄膜晶体管、第四薄膜晶体管、第五薄膜晶体管、及第六薄膜晶体管均为低温多晶硅薄膜晶体管、氧化物半导体薄膜晶体管、或非晶硅薄膜晶体管。
所述第一扫描信号、第二扫描信号、及第三扫描信号均通过外部时序控制器提供。
所述预设电压为一恒定电压。
所述第一扫描信号、第二扫描信号、第三扫描信号、及数据信号相组合，先后对应于一预充电阶段、一阈值电压编程阶段、及一驱动发光阶段；
在所述预充电阶段，所述第一扫描信号提供高电位，所述第二扫描信号、第三扫描信号、及数据信号均提供低电位；
在所述阈值电压编程阶段，所述第一扫描信号提供低电位，所述第二扫描信号、第三扫描信号、及数据信号均提供高电位；
在所述驱动发光阶段，所述第一扫描信号、第二扫描信号、及数据信号均提供低电位，所述第三扫描信号提供高电位。
本发明还提供一种AMOLED像素驱动方法，包括如下步骤：
步骤1、提供一AMOLED像素驱动电路；
所述AMOLED像素驱动电路包括：第一薄膜晶体管、第二薄膜晶体管、第三薄膜晶体管、第四薄膜晶体管、第五薄膜晶体管、第六薄膜晶体管、电容、及有机发光二极管；
所述第一薄膜晶体管为双栅极薄膜晶体管，其底栅接入预设电压，顶栅电性连接第一节点，源极电性连接第二节点，漏极接入电源电压；
所述第二薄膜晶体管为双栅极薄膜晶体管，并与第一薄膜晶体管呈镜像关系，其底栅电性连接第六薄膜晶体管的漏极，顶栅及漏极均电性连接第一节点，源极电性连接第二节点；
所述第三薄膜晶体管的栅极接入第一扫描信号，源极接入电源电压，漏极电性连接第一节点；
所述第四薄膜晶体管的栅极接入第二扫描信号，源极电性连接数据信号，漏极电性连接第二节点；
所述第五薄膜晶体管的栅极接入第三扫描信号，源极电性连接第二节点，漏极电性连接有机发光二极管的阳极；
所述第六薄膜晶体管的栅极接入第二扫描信号，源极接入预设电压，漏极电性连接第二薄膜晶体管的底栅；
所述电容的一端电性连接第一节点，另一端接地；
所述有机发光二极管的阳极电性连接第二节点，阴极接地；
其中，双栅极的第一薄膜晶体管用于驱动有机发光二极管，第四薄膜晶体管用于控制数据信号的进入；
步骤2、进入预充电阶段；
所述第一扫描信号提供高电位，第三薄膜晶体管打开，电容充电；第二扫描信号提供低电位，第四、及第六薄膜晶体管关闭；第三扫描信号提供低电位，第五薄膜晶体管关闭；所述第二薄膜晶体管的漏极与顶栅、及第一薄膜晶体管的顶栅写入电源电压，第一薄膜晶体管的底栅写入预设电压；数据信号提供低电位；
步骤3、进入阈值电压编程阶段；
所述第一扫描信号提供低电位，第三薄膜晶体管关闭；所述第二扫描信号提供高电位，第四、及第六薄膜晶体管打开；第三扫描信号提供高电位，第五薄膜晶体管打开；第二薄膜晶体管的底栅写入预设电压，第一薄膜晶体管的源极和第二薄膜晶体管的源极写入数据信号提供的高电位，第一薄膜晶体管的底栅保持预设电压；第二薄膜晶体管打开，第二薄膜晶体管的顶栅和漏极的电压、及第一薄膜晶体管的顶栅的电压随时间不断下降，第一薄膜晶体管和第二薄膜晶体管的阈值电压不断上升，当第一薄膜晶体管和第二薄膜晶体管的阈值电压达到Vth＝Vpre-Vdata，其中Vth为第一薄膜晶体管及第二薄膜晶体管的阈值电压，Vpre为预设电压，Vdata为数据信号提供的高电位，第一薄膜晶体管及第二薄膜晶体管的阈值电压不再变化，此时第一薄膜晶体管和第二薄膜晶体管的顶栅电压储存在电容中；
步骤4、进入驱动发光阶段；
所述第一扫描信号提供低电位，第三薄膜晶体管保持关闭；所述第二扫描信号提供低电位，第四、及第六薄膜晶体管关闭；所述第三扫描信号提供高电位，所述第五薄膜晶体管保持打开；第一薄膜晶体管的顶栅及第二薄膜晶体管的顶栅的电压值在电容的存储作用下保持不变，维持第一薄膜晶体管的阈值电压为Vth＝Vpre-Vdata；第一薄膜晶体管的底栅保持预设电压，第一薄膜晶体管打开，第一薄膜晶体管的源极电压转变为有机发光二极管阳极的电压，有机发光二极管发光，且流经所述有机发光二极管的电流与第一薄膜晶体管的阈值电压无关。
所述第一薄膜晶体管、第二薄膜晶体管、第三薄膜晶体管、第四薄膜晶体管、第五薄膜晶体管、及第六薄膜晶体管均为低温多晶硅薄膜晶体管、氧化物半导体薄膜晶体管、或非晶硅薄膜晶体管。
所述第一扫描信号、第二扫描信号、及第三扫描信号均通过外部时序 控制器提供。
所述预设电压为一恒定电压。
本发明还提供一种AMOLED像素驱动电路，包括：第一薄膜晶体管、第二薄膜晶体管、第三薄膜晶体管、第四薄膜晶体管、第五薄膜晶体管、第六薄膜晶体管、电容、及有机发光二极管；
所述第一薄膜晶体管为双栅极薄膜晶体管，其底栅接入预设电压，顶栅电性连接第一节点，源极电性连接第二节点，漏极接入电源电压；
所述第二薄膜晶体管为双栅极薄膜晶体管，并与第一薄膜晶体管呈镜像关系，其底栅电性连接第六薄膜晶体管的漏极，顶栅及漏极均电性连接第一节点，源极电性连接第二节点；
所述第三薄膜晶体管的栅极接入第一扫描信号，源极接入电源电压，漏极电性连接第一节点；
所述第四薄膜晶体管的栅极接入第二扫描信号，源极电性连接数据信号，漏极电性连接第二节点；
所述第五薄膜晶体管的栅极接入第三扫描信号，源极电性连接第二节点，漏极电性连接有机发光二极管的阳极；
所述第六薄膜晶体管的栅极接入第二扫描信号，源极接入预设电压，漏极电性连接第二薄膜晶体管的底栅；
所述电容的一端电性连接第一节点，另一端接地；
所述有机发光二极管的阳极电性连接第二节点，阴极接地；
其中，双栅极的第一薄膜晶体管用于驱动有机发光二极管，第四薄膜晶体管用于控制数据信号的进入；
其中，所述第一薄膜晶体管、第二薄膜晶体管、第三薄膜晶体管、第四薄膜晶体管、第五薄膜晶体管、及第六薄膜晶体管均为低温多晶硅薄膜晶体管、氧化物半导体薄膜晶体管、或非晶硅薄膜晶体管；
其中，所述第一扫描信号、第二扫描信号、及第三扫描信号均通过外部时序控制器提供。
本发明的有益效果：本发明提供的一种AMOLED像素驱动电路，采用双栅极薄膜晶体管作为驱动薄膜晶体管，在预充电阶段通过第一扫描信号控制第三薄膜晶体管打开，使第一薄膜晶体管即驱动薄膜晶体管的顶栅、及第二薄膜晶体管的顶栅及漏极写入电源电压；在阈值电压编程阶段通过第二扫描信号控制第四、第六薄膜晶体管打开，使第一薄膜晶体管和第二薄膜晶体管的顶栅电压降低而阈值电压升高，直至阈值电压提升至Vth＝Vpre-Vdata；在驱动发光阶段，第一薄膜晶体管的顶栅电压保持不变， 维持其阈值电压仍为Vth＝Vpre-Vdata，预设电压控制第一薄膜晶体管打开，使有机发光二极管发光，流过有机发光二极管的电流与第一薄膜晶体管的阈值电压无关，从而能够保证有机发光二极管的发光亮度均匀，改善画面的显示效果；另外，双栅极薄膜晶体所受电压与光照的应力对其阈值电压的影响较小，且双栅极薄膜晶体管阈值电压与顶栅电压呈负相关特性，将双栅极薄膜晶体用作驱动薄膜晶体管，能够通过输入预设电压来指定驱动晶体管的阈值电压，无需通过调整数据信号的大小来减弱驱动薄膜晶体管的阈值电压漂移。本发明提供的一种AMOLED像素驱动方法，能够对驱动薄膜晶体管的阈值电压进行有效补偿，解决由阈值电压漂移导致的流过有机发光二极管的电流不稳定的问题，使有机发光二极管的发光亮度均匀，改善画面的显示效果。
附图说明
为了能更进一步了解本发明的特征以及技术内容，请参阅以下有关本发明的详细说明与附图，然而附图仅提供参考与说明用，并非用来对本发明加以限制。
附图中，
图1为本发明的AMOLED像素驱动电路的电路图；
图2为本发明的AMOLED像素驱动电路的时序图；
图3为本发明的AMOLED像素驱动方法的步骤2的示意图；
图4为本发明的AMOLED像素驱动方法的步骤3的示意图；
图5为本发明的AMOLED像素驱动方法的步骤4的示意图。
具体实施方式
为更进一步阐述本发明所采取的技术手段及其效果，以下结合本发明的优选实施例及其附图进行详细描述。
请参阅图1及图2，本发明提供一种6T1C结构的AMOLED像素驱动电路，包括：第一薄膜晶体管T1、第二薄膜晶体管T2、第三薄膜晶体管T3、第四薄膜晶体管T4、第五薄膜晶体管T5、第六薄膜晶体管T6、电容C1、及有机发光二极管D1。
所述第一薄膜晶体管T1为双栅极薄膜晶体管，其底栅BG1接入预设电压Vpre，顶栅TG1电性连接第一节点A，源极电性连接第二节点B，漏极接入电源电压VDD；该双栅极的第一薄膜晶体管T1作为驱动薄膜晶体管，用于驱动有机发光二极管D1。根据目前的研究，双栅极薄膜晶体管的 特点在于电压与光照应力对其阈值电压的影响较小，同时其阈值电压与顶栅电压呈负相关趋势，即顶栅电压越大，阈值电压越小。
所述第二薄膜晶体管T2为双栅极薄膜晶体管，并与第一薄膜晶体管T1呈镜像关系，其底栅BG2电性连接第六薄膜晶体管T6的漏极，顶栅TG2及漏极均电性连接第一节点A，源极电性连接第二节点B。由于所述第一薄膜晶体管T1与第二薄膜晶体管T2呈镜像关系，二者在顶栅电压相同时具有相同的阈值电压。
所述第三薄膜晶体管T3的栅极接入第一扫描信号Scan1，源极接入电源电压VDD，漏极电性连接第一节点A。
所述第四薄膜晶体管T4的栅极接入第二扫描信号Scan2，源极电性连接数据信号Data，漏极电性连接第二节点B。该第四薄膜晶体管T4用于控制数据信号Data的进入。
所述第五薄膜晶体管T5的栅极接入第三扫描信号Scan3，源极电性连接第二节点B，漏极电性连接有机发光二极管D1的阳极。
所述第六薄膜晶体管T6的栅极接入第二扫描信号Scan2，源极接入预设电压Vpre，漏极电性连接第二薄膜晶体管T2的底栅BG2。
所述电容C1的一端电性连接第一节点A，另一端接地。
所述有机发光二极管D1的阳极电性连接第二节点B，阴极接地。
具体地，所述第一薄膜晶体管T1、第二薄膜晶体管T2、第三薄膜晶体管T3、第四薄膜晶体管T4、第五薄膜晶体管T5、及第六薄膜晶体管T6均为低温多晶硅薄膜晶体管、氧化物半导体薄膜晶体管、或非晶硅薄膜晶体管。
具体地，所述第一扫描信号Scan1、第二扫描信号Scan2、及第三扫描信号Scan3均通过外部时序控制器提供。
具体地，所述预设电压Vpre为一恒定电压。
具体地，请参阅图2，所述第一扫描信号Scan1、第二扫描信号Scan2、第三扫描信号Scan3、及数据信号Data相组合，先后对应于一预充电阶段1、一阈值电压编程阶段2、及一驱动发光阶段3。在所述预充电阶段1，所述第一扫描信号Scan1提供高电位，所述第二扫描信号Scan2第三扫描信号Scan3、及数据信号Data均提供低电位；在所述阈值电压编程阶段2，所述第一扫描信号Scan1提供低电位，所述第二扫描信号Scan2、第三扫描信号Scan3、及数据信号Data均提供高电位；在所述驱动发光阶段3，所述第一扫描信号Scan1、第二扫描信号Scan2、及数据信号Data均提供低电位，所述第三扫描信号Scan3提供高电位。
进一步地，结合图1及图2，本发明的AMOLED像素驱动电路的工作过程如下：
在预充电阶段1，所述第一扫描信号Scan1提供高电位，第三薄膜晶体管T3打开，电容C1充电；第二扫描信号Scan2提供低电位，第四、及第六薄膜晶体管T4、T6关闭；第三扫描信号Scan3提供低电位，第五薄膜晶体管T5关闭；电源电压VDD经导通的第三薄膜晶体管T3写入所述第一薄膜晶体管T1的顶栅TG1、及第二薄膜晶体管T2的顶栅TG2与漏极，第一薄膜晶体管T1的底栅BG1写入预设电压Vpre；数据信号Data提供低电位；
在阈值电压编程阶段2，所述第一扫描信号Scan1提供低电位，第三薄膜晶体管T3关闭；所述第二扫描信号Scan2提供高电位，第四、及第六薄膜晶体管T4、T6打开；第三扫描信号Scan3提供高电位，第五薄膜晶体管T5打开；预设电压Vpre通过打开的第六薄膜晶体管T6写入第二薄膜晶体管T2的底栅BG2，第一薄膜晶体管T1的源极和第二薄膜晶体管T2的源极写入数据信号Data提供的高电位，第一薄膜晶体管T1的底栅BG1保持预设电压Vpre；由于双栅极薄膜晶体管的阈值电压与顶栅电压负相关，此时第一薄膜晶体管T1及第二薄膜晶体管T2的阈值电压值非常小，第一薄膜晶体管T1和第二薄膜晶体管T2均打开；随着时间推移及电容C1放电，第二薄膜晶体管T2的顶栅TG2与漏极的电压、及第一薄膜晶体管T1的顶栅TG1的电压不断下降，第一薄膜晶体管T1和第二薄膜晶体管T2的阈值电压不断上升，当第一薄膜晶体管T1和第二薄膜晶体管T2的阈值电压达到Vth＝VBG-Vs时，也即Vth＝Vpre-Vdata时，其中VBG为第一薄膜晶体管T1及第二薄膜晶体管T2的底栅电压，Vs为第一薄膜晶体管T1及第二薄膜晶体管T2的源极电压，Vth为第一薄膜晶体管T1和第二薄膜晶体管T2的阈值电压，Vdata为数据信号Data提供的高电位，第一薄膜晶体管T1及第二薄膜晶体管T2的阈值电压不再变化，第一薄膜晶体管T1和第二薄膜晶体管T2的顶栅电压VTG存入电容C1中；值得注意的是，在该阈值电压编程阶段2，由于双栅极薄膜晶体所受电压与光照的应力对其阈值电压的影响较小，且双栅极薄膜晶体管阈值电压与顶栅电压呈负相关特性，将双栅极薄膜晶体用作驱动薄膜晶体管，能够通过输入预设电压Vpre来指定驱动晶体管的阈值电压，无需通过调整数据信号Data的大小来减弱驱动薄膜晶体管的阈值电压漂移；
在驱动发光阶段3，所述第一扫描信号Scan1提供低电位，第三薄膜晶体管T3保持关闭；所述第二扫描信号Scan2提供低电位，第四、及第六薄膜晶体管T4、T6关闭；所述第三扫描信号Scan3提供高电位，所述第五薄 膜晶体管T5保持打开；第一薄膜晶体管T1的顶栅TG1及第二薄膜晶体管T2的顶栅TG2的电压值在电容C1的存储作用下保持不变，维持第一薄膜晶体管T1的阈值电压为Vth＝Vpre-Vdata；第一薄膜晶体管T1的底栅BG1保持预设电压Vpre，第一薄膜晶体管T1打开，第一薄膜晶体管T1的源极电压转变为有机发光二极管D1阳极的电压VOLED，有机发光二极管D1发光；
根据流过有机发光二极管的电流公式：
I＝β(VBG-Vth-VS)2
＝β(Vpre-Vpre+Vdata-VOLED)2
＝β(Vdata-VOLED)2
其中，β为一与薄膜晶体管特性有关的常值系数。
可见流过第一薄膜晶体管T1及有机发光二极管D1的电流值与第一薄膜晶体管T1的阈值电压Vth无关，补偿了驱动薄膜晶体管的阈值电压漂移，解决了由阈值电压漂移导致的流过有机发光二极管的电流不稳定的问题，能够使有机发光二极管的发光亮度均匀，改善画面的显示效果。
请同时参阅图3至图5，结合图1及图2，基于上述AMOLED像素驱动电路，本发明还提供一种AMOLED像素驱动方法，包括如下步骤：
步骤1、提供一AMOLED像素驱动电路。
所述AMOLED像素驱动电路包括：第一薄膜晶体管T1、第二薄膜晶体管T2、第三薄膜晶体管T3、第四薄膜晶体管T4、第五薄膜晶体管T5、第六薄膜晶体管T6、电容C1、及有机发光二极管D1。双栅极薄膜晶体管的特点在于电压与光照应力对其阈值电压的影响较小，同时其阈值电压与顶栅电压呈负相关趋势，即顶栅电压越大，阈值电压越小。
所述第一薄膜晶体管T1为双栅极薄膜晶体管，其底栅BG1接入预设电压Vpre，顶栅TG1电性连接第一节点A，源极电性连接第二节点B，漏极接入电源电压VDD；该双栅极的第一薄膜晶体管T1作为驱动薄膜晶体管，用于驱动有机发光二极管D1。
所述第二薄膜晶体管T2为双栅极薄膜晶体管，并与第一薄膜晶体管T1呈镜像关系，其底栅BG2电性连接第六薄膜晶体管T6的漏极，顶栅TG2及漏极均电性连接第一节点A，源极电性连接第二节点B。由于所述第一薄膜晶体管T1与第二薄膜晶体管T2呈镜像关系，二者在顶栅电压相同时具有相同的阈值电压。
所述第三薄膜晶体管T3的栅极接入第一扫描信号Scan1，源极接入电源电压VDD，漏极电性连接第一节点A。
所述第四薄膜晶体管T4的栅极接入第二扫描信号Scan2，源极电性连接数据信号Data，漏极电性连接第二节点B。该第四薄膜晶体管T4用于控制数据信号Data的进入。
所述第五薄膜晶体管T5的栅极接入第三扫描信号Scan3，源极电性连接第二节点B，漏极电性连接有机发光二极管D1的阳极。
所述第六薄膜晶体管T6的栅极接入第二扫描信号Scan2，源极接入预设电压Vpre，漏极电性连接第二薄膜晶体管T2的底栅BG2。
所述电容C1的一端电性连接第一节点A，另一端接地。
所述有机发光二极管D1的阳极电性连接第二节点B，阴极接地。
具体地，所述第一薄膜晶体管T1、第二薄膜晶体管T2、第三薄膜晶体管T3、第四薄膜晶体管T4、第五薄膜晶体管T5、及第六薄膜晶体管T6均为低温多晶硅薄膜晶体管、氧化物半导体薄膜晶体管、或非晶硅薄膜晶体管。
具体地，所述第一扫描信号Scan1、第二扫描信号Scan2、及第三扫描信号Scan3均通过外部时序控制器提供。
具体地，所述预设电压Vpre为一恒定电压。
步骤2、进入预充电阶段1。
所述第一扫描信号Scan1提供高电位，第三薄膜晶体管T3打开，电容C1充电；第二扫描信号Scan2提供低电位，第四、及第六薄膜晶体管T4、T6关闭；第三扫描信号Scan3提供低电位，第五薄膜晶体管T5关闭；电源电压VDD经导通的第三薄膜晶体管T3写入所述第一薄膜晶体管T1的顶栅TG1、及第二薄膜晶体管T2的顶栅TG2与漏极，第一薄膜晶体管T1的底栅BG1写入预设电压Vpre；数据信号Data提供低电位。
步骤3、进入阈值电压编程阶段2。
所述第一扫描信号Scan1提供低电位，第三薄膜晶体管T3关闭；所述第二扫描信号Scan2提供高电位，第四、及第六薄膜晶体管T4、T6打开；第三扫描信号Scan3提供高电位，第五薄膜晶体管T5打开；预设电压Vpre通过导通的第六薄膜晶体管T6写入第二薄膜晶体管T2的底栅BG2，数据信号Data提供的高电位通过导通的第四薄膜晶体管T4写入第一薄膜晶体管T1的源极和第二薄膜晶体管T2的源极，第一薄膜晶体管T1的底栅BG1保持预设电压Vpre；由于双栅极薄膜晶体管的阈值电压与顶栅电压负相关，此时第一薄膜晶体管T1及第二薄膜晶体管T2的阈值电压值非常小，第一薄膜晶体管T1和第二薄膜晶体管T2均打开；随着时间推移及电容C1放电，第二薄膜晶体管T2的顶栅TG2与漏极的电压、及第一薄膜晶体管 T1的顶栅TG1的电压不断下降，第一薄膜晶体管T1和第二薄膜晶体管T2的阈值电压不断上升，当第一薄膜晶体管T1和第二薄膜晶体管T2的阈值电压达到Vth＝VBG-Vs时，也即Vth＝Vpre-Vdata时，其中VBG为第一薄膜晶体管T1及第二薄膜晶体管T2的底栅电压，Vs为第一薄膜晶体管T1及第二薄膜晶体管T2的源极电压，Vth为第一薄膜晶体管T1和第二薄膜晶体管T2的阈值电压，Vdata为数据信号Data提供的高电位，第一薄膜晶体管T1及第二薄膜晶体管T2的阈值电压不再变化，第一薄膜晶体管T1和第二薄膜晶体管T2的顶栅电压VTG存入电容C1中。
值得注意的是，在该步骤3中，由于双栅极薄膜晶体所受电压与光照的应力对其阈值电压的影响较小，且双栅极薄膜晶体管阈值电压与顶栅电压呈负相关特性，将双栅极薄膜晶体用作驱动薄膜晶体管，能够通过输入预设电压Vpre来指定驱动晶体管的阈值电压，无需通过调整数据信号Data的大小来减弱驱动薄膜晶体管的阈值电压漂移。
步骤4、进入驱动发光阶段3。
所述第一扫描信号Scan1提供低电位，第三薄膜晶体管T3保持关闭；所述第二扫描信号Scan2提供低电位，第四、及第六薄膜晶体管T4、T6关闭；所述第三扫描信号Scan3提供高电位，所述第五薄膜晶体管T5保持打开；第一薄膜晶体管T1的顶栅TG1及第二薄膜晶体管T2的顶栅TG2的电压值在电容C1的存储作用下保持不变，维持第一薄膜晶体管T1的阈值电压为Vth＝Vpre-Vdata；第一薄膜晶体管T1的底栅BG1保持预设电压Vpre，第一薄膜晶体管T1打开，第一薄膜晶体管T1的源极电压转变为有机发光二极管D1阳极的电压VOLED，有机发光二极管D1发光。
根据流过有机发光二极管的电流公式：
I＝β(VBG-Vth-VS)2
＝β(Vpre-Vpre+Vdata-VOLED)2
＝β(Vdata-VOLED)2
其中，β为一与薄膜晶体管特性有关的常值系数。
可见流过第一薄膜晶体管T1及有机发光二极管D1的电流值与第一薄膜晶体管T1的阈值电压Vth无关，补偿了驱动薄膜晶体管的阈值电压漂移，解决了由阈值电压漂移导致的流过有机发光二极管的电流不稳定的问题，能够使有机发光二极管的发光亮度均匀，改善画面的显示效果。
综上所述，本发明的AMOLED像素驱动电路，采用双栅极薄膜晶体管作为驱动薄膜晶体管，在预充电阶段通过第一扫描信号控制第三薄膜晶体管打开，使第一薄膜晶体管即驱动薄膜晶体管的顶栅、及第二薄膜晶体管 的顶栅及漏极写入电源电压；在阈值电压编程阶段通过第二扫描信号控制第四、第六薄膜晶体管打开，使第一薄膜晶体管和第二薄膜晶体管的顶栅电压降低而阈值电压升高，直至阈值电压提升至Vth＝Vpre-Vdata；在驱动发光阶段，第一薄膜晶体管的顶栅电压保持不变，维持其阈值电压仍为Vth＝Vpre-Vdata，预设电压控制第一薄膜晶体管打开，使有机发光二极管发光，流过有机发光二极管的电流与第一薄膜晶体管的阈值电压无关，从而能够保证有机发光二极管的发光亮度均匀，改善画面的显示效果；另外，双栅极薄膜晶体所受电压与光照的应力对其阈值电压的影响较小，且双栅极薄膜晶体管阈值电压与顶栅电压呈负相关特性，将双栅极薄膜晶体用作驱动薄膜晶体管，能够通过输入预设电压来指定驱动晶体管的阈值电压，无需通过调整数据信号的大小来减弱驱动薄膜晶体管的阈值电压漂移。本发明的AMOLED像素驱动方法，能够对驱动薄膜晶体管的阈值电压进行有效补偿，解决由阈值电压漂移导致的流过有机发光二极管的电流不稳定的问题，使有机发光二极管的发光亮度均匀，改善画面的显示效果。
以上所述，对于本领域的普通技术人员来说，可以根据本发明的技术方案和技术构思作出其他各种相应的改变和变形，而所有这些改变和变形都应属于本发明权利要求的保护范围。

Claims (12)

  1. 一种AMOLED像素驱动电路，包括：第一薄膜晶体管、第二薄膜晶体管、第三薄膜晶体管、第四薄膜晶体管、第五薄膜晶体管、第六薄膜晶体管、电容、及有机发光二极管；
    所述第一薄膜晶体管为双栅极薄膜晶体管，其底栅接入预设电压，顶栅电性连接第一节点，源极电性连接第二节点，漏极接入电源电压；
    所述第二薄膜晶体管为双栅极薄膜晶体管，并与第一薄膜晶体管呈镜像关系，其底栅电性连接第六薄膜晶体管的漏极，顶栅及漏极均电性连接第一节点，源极电性连接第二节点；
    所述第三薄膜晶体管的栅极接入第一扫描信号，源极接入电源电压，漏极电性连接第一节点；
    所述第四薄膜晶体管的栅极接入第二扫描信号，源极电性连接数据信号，漏极电性连接第二节点；
    所述第五薄膜晶体管的栅极接入第三扫描信号，源极电性连接第二节点，漏极电性连接有机发光二极管的阳极；
    所述第六薄膜晶体管的栅极接入第二扫描信号，源极接入预设电压，漏极电性连接第二薄膜晶体管的底栅；
    所述电容的一端电性连接第一节点，另一端接地；
    所述有机发光二极管的阳极电性连接第二节点，阴极接地；
    其中，双栅极的第一薄膜晶体管用于驱动有机发光二极管，第四薄膜晶体管用于控制数据信号的进入。
  2. 如权利要求1所述的AMOLED像素驱动电路，其中，所述第一薄膜晶体管、第二薄膜晶体管、第三薄膜晶体管、第四薄膜晶体管、第五薄膜晶体管、及第六薄膜晶体管均为低温多晶硅薄膜晶体管、氧化物半导体薄膜晶体管、或非晶硅薄膜晶体管。
  3. 如权利要求1所述的AMOLED像素驱动电路，其中，所述第一扫描信号、第二扫描信号、及第三扫描信号均通过外部时序控制器提供。
  4. 如权利要求1所述的AMOLED像素驱动电路，其中，所述预设电压为一恒定电压。
  5. 如权利要求1所述的AMOLED像素驱动电路，其中，所述第一扫描信号、第二扫描信号、第三扫描信号、及数据信号相组合，先后对应于一预充电阶段、一阈值电压编程阶段、及一驱动发光阶段；
    在所述预充电阶段，所述第一扫描信号提供高电位，所述第二扫描信号、第三扫描信号、及数据信号均提供低电位；
    在所述阈值电压编程阶段，所述第一扫描信号提供低电位，所述第二扫描信号、第三扫描信号、及数据信号均提供高电位；
    在所述驱动发光阶段，所述第一扫描信号、第二扫描信号、及数据信号均提供低电位，所述第三扫描信号提供高电位。
  6. 一种AMOLED像素驱动方法，包括如下步骤：
    步骤1、提供一AMOLED像素驱动电路；
    所述AMOLED像素驱动电路包括：第一薄膜晶体管、第二薄膜晶体管、第三薄膜晶体管、第四薄膜晶体管、第五薄膜晶体管、第六薄膜晶体管、电容、及有机发光二极管；
    所述第一薄膜晶体管为双栅极薄膜晶体管，其底栅接入预设电压，顶栅电性连接第一节点，源极电性连接第二节点，漏极接入电源电压；
    所述第二薄膜晶体管为双栅极薄膜晶体管，并与第一薄膜晶体管呈镜像关系，其底栅电性连接第六薄膜晶体管的漏极，顶栅及漏极均电性连接第一节点，源极电性连接第二节点；
    所述第三薄膜晶体管的栅极接入第一扫描信号，源极接入电源电压，漏极电性连接第一节点；
    所述第四薄膜晶体管的栅极接入第二扫描信号，源极电性连接数据信号，漏极电性连接第二节点；
    所述第五薄膜晶体管的栅极接入第三扫描信号，源极电性连接第二节点，漏极电性连接有机发光二极管的阳极；
    所述第六薄膜晶体管的栅极接入第二扫描信号，源极接入预设电压，漏极电性连接第二薄膜晶体管的底栅；
    所述电容的一端电性连接第一节点，另一端接地；
    所述有机发光二极管的阳极电性连接第二节点，阴极接地；
    其中，双栅极的第一薄膜晶体管用于驱动有机发光二极管，第四薄膜晶体管用于控制数据信号的进入；
    步骤2、进入预充电阶段；
    所述第一扫描信号提供高电位，第三薄膜晶体管打开，电容充电；第二扫描信号提供低电位，第四、及第六薄膜晶体管关闭；第三扫描信号提供低电位，第五薄膜晶体管关闭；所述第二薄膜晶体管的漏极与顶栅、及第一薄膜晶体管的顶栅写入电源电压，第一薄膜晶体管的底栅写入预设电压；数据信号提供低电位；
    步骤3、进入阈值电压编程阶段；
    所述第一扫描信号提供低电位，第三薄膜晶体管关闭；所述第二扫描信号提供高电位，第四、及第六薄膜晶体管打开；第三扫描信号提供高电位，第五薄膜晶体管打开；第二薄膜晶体管的底栅写入预设电压，第一薄膜晶体管的源极和第二薄膜晶体管的源极写入数据信号提供的高电位，第一薄膜晶体管的底栅保持预设电压；第二薄膜晶体管打开，第二薄膜晶体管的顶栅和漏极的电压、及第一薄膜晶体管的顶栅的电压随时间不断下降，第一薄膜晶体管和第二薄膜晶体管的阈值电压不断上升，当第一薄膜晶体管和第二薄膜晶体管的阈值电压达到Vth＝Vpre-Vdata，其中Vth为第一薄膜晶体管及第二薄膜晶体管的阈值电压，Vpre为预设电压，Vdata为数据信号提供的高电位，第一薄膜晶体管及第二薄膜晶体管的阈值电压不再变化，此时第一薄膜晶体管和第二薄膜晶体管的顶栅电压储存在电容中；
    步骤4、进入驱动发光阶段；
    所述第一扫描信号提供低电位，第三薄膜晶体管保持关闭；所述第二扫描信号提供低电位，第四、及第六薄膜晶体管关闭；所述第三扫描信号提供高电位，所述第五薄膜晶体管保持打开；第一薄膜晶体管的顶栅及第二薄膜晶体管的顶栅的电压值在电容的存储作用下保持不变，维持第一薄膜晶体管的阈值电压为Vth＝Vpre-Vdata；第一薄膜晶体管的底栅保持预设电压，第一薄膜晶体管打开，第一薄膜晶体管的源极电压转变为有机发光二极管阳极的电压，有机发光二极管发光，且流经所述有机发光二极管的电流与第一薄膜晶体管的阈值电压无关。
  7. 如权利要求6所述的AMOLED像素驱动方法，其中，所述第一薄膜晶体管、第二薄膜晶体管、第三薄膜晶体管、第四薄膜晶体管、第五薄膜晶体管、及第六薄膜晶体管均为低温多晶硅薄膜晶体管、氧化物半导体薄膜晶体管、或非晶硅薄膜晶体管。
  8. 如权利要求6所述的AMOLED像素驱动方法，其中，所述第一扫描信号、第二扫描信号、及第三扫描信号均通过外部时序控制器提供。
  9. 如权利要求6所述的AMOLED像素驱动方法，其中，所述预设电压为一恒定电压。
  10. 一种AMOLED像素驱动电路，包括：第一薄膜晶体管、第二薄膜晶体管、第三薄膜晶体管、第四薄膜晶体管、第五薄膜晶体管、第六薄膜晶体管、电容、及有机发光二极管；
    所述第一薄膜晶体管为双栅极薄膜晶体管，其底栅接入预设电压，顶栅电性连接第一节点，源极电性连接第二节点，漏极接入电源电压；
    所述第二薄膜晶体管为双栅极薄膜晶体管，并与第一薄膜晶体管呈镜像关系，其底栅电性连接第六薄膜晶体管的漏极，顶栅及漏极均电性连接第一节点，源极电性连接第二节点；
    所述第三薄膜晶体管的栅极接入第一扫描信号，源极接入电源电压，漏极电性连接第一节点；
    所述第四薄膜晶体管的栅极接入第二扫描信号，源极电性连接数据信号，漏极电性连接第二节点；
    所述第五薄膜晶体管的栅极接入第三扫描信号，源极电性连接第二节点，漏极电性连接有机发光二极管的阳极；
    所述第六薄膜晶体管的栅极接入第二扫描信号，源极接入预设电压，漏极电性连接第二薄膜晶体管的底栅；
    所述电容的一端电性连接第一节点，另一端接地；
    所述有机发光二极管的阳极电性连接第二节点，阴极接地；
    其中，双栅极的第一薄膜晶体管用于驱动有机发光二极管，第四薄膜晶体管用于控制数据信号的进入；
    其中，所述第一薄膜晶体管、第二薄膜晶体管、第三薄膜晶体管、第四薄膜晶体管、第五薄膜晶体管、及第六薄膜晶体管均为低温多晶硅薄膜晶体管、氧化物半导体薄膜晶体管、或非晶硅薄膜晶体管；
    其中，所述第一扫描信号、第二扫描信号、及第三扫描信号均通过外部时序控制器提供。
  11. 如权利要求10所述的AMOLED像素驱动电路，其中，所述预设电压为一恒定电压。
  12. 如权利要求10所述的AMOLED像素驱动电路，其中，所述第一扫描信号、第二扫描信号、第三扫描信号、及数据信号相组合，先后对应于一预充电阶段、一阈值电压编程阶段、及一驱动发光阶段；
    在所述预充电阶段，所述第一扫描信号提供高电位，所述第二扫描信号、第三扫描信号、及数据信号均提供低电位；
    在所述阈值电压编程阶段，所述第一扫描信号提供低电位，所述第二扫描信号、第三扫描信号、及数据信号均提供高电位；
    在所述驱动发光阶段，所述第一扫描信号、第二扫描信号、及数据信号均提供低电位，所述第三扫描信号提供高电位。
PCT/CN2016/110900 2016-10-14 2016-12-20 Amoled像素驱动电路及驱动方法 Ceased WO2018068391A1 (zh)

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