WO2019090907A1 - 一种像素驱动电路及有机发光二极管显示装置 - Google Patents

一种像素驱动电路及有机发光二极管显示装置 Download PDF

Info

Publication number
WO2019090907A1
WO2019090907A1 PCT/CN2017/117170 CN2017117170W WO2019090907A1 WO 2019090907 A1 WO2019090907 A1 WO 2019090907A1 CN 2017117170 W CN2017117170 W CN 2017117170W WO 2019090907 A1 WO2019090907 A1 WO 2019090907A1
Authority
WO
WIPO (PCT)
Prior art keywords
switch
transistor
data
control
node
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/CN2017/117170
Other languages
English (en)
French (fr)
Inventor
毛鹏
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Wuhan China Star Optoelectronics Semiconductor Display Technology Co Ltd
Original Assignee
Wuhan China Star Optoelectronics Semiconductor Display Technology Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Wuhan China Star Optoelectronics Semiconductor Display Technology Co Ltd filed Critical Wuhan China Star Optoelectronics Semiconductor Display Technology Co Ltd
Priority to US15/754,218 priority Critical patent/US10650740B2/en
Publication of WO2019090907A1 publication Critical patent/WO2019090907A1/zh
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Images

Classifications

    • 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
    • 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
    • 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
    • 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
    • G09G3/34—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 by control of light from an independent source
    • G09G3/36—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 by control of light from an independent source using liquid crystals
    • G09G3/3611—Control of matrices with row and column drivers
    • G09G3/3648—Control of matrices with row and column drivers using an active matrix
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • 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
    • G09G2300/0809—Several active elements per pixel in active matrix panels
    • G09G2300/0819—Several active elements per pixel in active matrix panels used for counteracting undesired variations, e.g. feedback or autozeroing
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • 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
    • G09G2300/0809—Several active elements per pixel in active matrix panels
    • G09G2300/0842—Several active elements per pixel in active matrix panels forming a memory circuit, e.g. a dynamic memory with one capacitor
    • G09G2300/0852—Several active elements per pixel in active matrix panels forming a memory circuit, e.g. a dynamic memory with one capacitor being a dynamic memory with more than one capacitor
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • 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
    • G09G2300/0809—Several active elements per pixel in active matrix panels
    • G09G2300/0842—Several active elements per pixel in active matrix panels forming a memory circuit, e.g. a dynamic memory with one capacitor
    • 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
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00—Command of the display device
    • G09G2310/08—Details of timing specific for flat panels, other than clock recovery
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00—Control of display operating conditions
    • G09G2320/02—Improving the quality of display appearance
    • G09G2320/0233—Improving the luminance or brightness uniformity across the screen

Definitions

  • the present invention relates to the field of display technologies, and in particular, to a pixel driving circuit and a liquid crystal display device.
  • the organic light emitting diode (OLED) display device has the advantages of low power consumption, high color gamut, high brightness, high resolution, wide viewing angle, high response speed and the like.
  • the OLED display device can be classified into two types: passive matrix OLED (PMOLED) and active matrix OLED (AMOLED) according to the driving method.
  • PMOLED passive matrix OLED
  • AMOLED active matrix OLED
  • 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 the AMOLED needs to complete the task of converting the voltage signal into a current signal.
  • the conventional AMOLED pixel driving circuit is usually 2T1C, that is, a structure in which two thin film transistors and one capacitor are used to convert a voltage into a current.
  • the conventional 2T1C pixel driving circuit for AMOLED is sensitive to the threshold voltage and channel mobility of the thin film transistor, the starting voltage and quantum efficiency of the organic light emitting diode, and the transient process of the power supply.
  • the threshold voltage of the driving thin film transistor drifts with the operation time, thereby causing the light emission of the organic light emitting diode to be unstable, causing a difference in luminance of the pixel driving circuit and lowering the display quality.
  • Embodiments of the present invention provide a pixel driving circuit and a liquid crystal display device, which can compensate for drift of a threshold voltage of a driving thin film transistor and improve display quality.
  • an embodiment of the present invention provides a pixel driving circuit, including a data writing switch tube, a first reset switch tube, a second reset switch tube, a driving transistor, an organic light emitting diode OLED, and a first storage capacitor. And a second storage capacitor;
  • the data is written to the source of the switch to the data line, and the data is written to the drain of the switch to the first node;
  • the first reset switch tube has a source connected to the first reference voltage, and the first reset switch tube has a drain connected to the second node;
  • the second reset switch tube has a source connected to a high level, and the second reset switch tube has a drain connected to the third node;
  • a gate of the driving transistor is connected to the first node, a source of the driving transistor is connected to the third node, and a drain of the driving transistor is connected to a positive electrode of the organic light emitting diode;
  • the first end of the first storage capacitor is connected to the third node, and the second end of the first storage capacitor is connected to the second node;
  • the first end of the second storage capacitor is connected to the second node, and the second end of the second storage capacitor is connected to the first node.
  • the circuit further includes: the first reset switch tube and the gate of the data write switch tube are connected to a scan control line, and the second reset The gate of the switch tube is connected to the first control signal, and the data line is used to write the data voltage when the data is written into the switch tube, and the first reset switch tube and the second reset switch tube are turned on, so that the first Two storage capacitors store the data voltage.
  • the circuit further includes: a compensation switch tube, a source of the compensation switch tube Connected to the second reference voltage, the gate of the compensation switch is connected to the second control signal, the drain of the compensation switch is connected to the drain of the driving transistor and the anode of the organic light emitting diode; the second storage capacitor stores the data voltage Then, the first storage capacitor is used to store the threshold voltage of the driving transistor when the data is written into the switch tube, and the first reset switch tube and the compensation switch tube are turned on.
  • the circuit further includes: a first control switch tube, and a second control switch tube And a third control switch, the source of the first control switch is connected to the power supply voltage, the gate of the first control switch is connected to the third control signal, and the drain of the first control switch is connected to the source of the drive transistor pole;
  • a source of the second control switch is connected to a drain of the driving transistor and a drain of the compensation switch, a gate of the second control switch is connected to the third control signal, and a drain of the second control switch Connecting the anode of the organic light emitting diode;
  • a source of the third control switch is connected to the second node, a gate of the third control switch is connected to a fourth control signal, and a drain of the third control switch is connected to the first node;
  • the first storage capacitor stores the threshold voltage of the driving transistor
  • the first control switch tube, the second control switch tube and the third control switch tube are simultaneously in an on state, so that the organic light emitting diode OLED emits light.
  • an embodiment of the present invention provides a liquid crystal display device comprising the pixel driving circuit described in the above first aspect or any possible implementation manner of the first aspect.
  • the first end of the first storage capacitor is connected to the second node, the second end of the first storage capacitor is connected to the second node, and the first end of the second storage capacitor is connected to the first a second node, the second end of the second storage capacitor is connected to the first node, so the threshold voltage of the driving transistor can be first stored in the first storage capacitor, and the saturation current formula of the organic light emitting diode OLED can be obtained and flowed through
  • the current of the organic light emitting diode OLED is controlled by the first reference voltage and the data voltage, so that the current flowing through the organic light emitting diode OLED is no longer affected by the threshold voltage of the driving thin film transistor, and can compensate for the drift of the threshold voltage of the driving thin film transistor, thereby Improve the uniformity of the OLED display and improve the display quality.
  • FIG. 1 is a schematic structural diagram of a pixel driving circuit according to an embodiment of the present invention.
  • FIG. 2 is an equivalent circuit diagram of a reset and data write phase of a pixel driving circuit according to an embodiment of the present invention
  • FIG. 3 is an equivalent circuit diagram of a compensation phase of a pixel driving circuit according to an embodiment of the present invention.
  • FIG. 4 is an equivalent circuit diagram of an illumination phase of a pixel driving circuit according to an embodiment of the present invention.
  • FIG. 5 is a timing chart of driving of a pixel driving circuit according to an embodiment of the present invention.
  • the term “if” can be interpreted as “when” or “on” or “in response to determining” or “in response to detecting” depending on the context.
  • the phrase “if determined” or “if detected [condition or event described]” may be interpreted in context to mean “once determined” or “in response to determining” or “once detected [condition or event described] ] or “in response to detecting [conditions or events described]”.
  • FIG. 1 is a circuit diagram of a pixel driving circuit including a data write switch transistor T1, a first reset switch transistor T2, a second reset switch transistor T3, a driving transistor T4, an organic light emitting diode OLED, and The first storage capacitor C1 and the second storage capacitor C2.
  • the data is written to the source of the switch T1 to the data line Data, and the drain of the data write switch T1 is connected to the first node A.
  • the source of the first reset switch T2 is connected to the first reference voltage V ref1 , and the drain of the first reset switch T2 is connected to the second node B.
  • the source of the second reset switch T3 is connected to the high level SW, and the drain of the second reset switch T3 is connected to the third node C.
  • the gate of the driving transistor T4 is connected to the first node A.
  • the source of the driving transistor T5 is connected to the third node C.
  • the drain of the driving transistor T5 is connected to the anode of the organic light emitting diode.
  • the first end of the first storage capacitor C1 is connected to the third node C, and the second end of the first storage capacitor C1 is connected to the second node B.
  • the first storage capacitor C1 has one end, the first end of the first storage capacitor C1 is referred to as a first end, and the other end of the first storage capacitor C1 is referred to as a second end.
  • the first end of the second storage capacitor C2 is connected to the second node B, and the second end of the second storage capacitor C1 is connected to the first node A.
  • the second storage capacitor C1 has two ends, one end of the second storage capacitor C1 is referred to as a first end, and the other end of the second storage capacitor C1 is referred to as a second end.
  • the circuit further includes: the first reset switch tube T2 and the gate of the data write switch tube T1 are connected to the scan control line Scan, and the gate of the second reset switch tube T3 is connected to the first control signal S1.
  • the data line Data is used to write the data voltage V data when the data is written to the switch T1, and the second reset switch T2 and the second reset switch T3 are turned on to make the second storage capacitor C2 stores the data voltage Vdata .
  • a second reference voltage V ref2 is input between the drain of the driving transistor T4 and the anode of the organic light emitting diode OLED such that the potential V C of the third node C is equal to the data voltage V data minus the threshold voltage of the driving transistor T4
  • the voltage difference of V th is such that the threshold voltage V th of the driving transistor T4 is stored in the first storage capacitor C1.
  • the power supply voltage V dd is input at the third node C, and the second storage capacitor C2 is shorted, so that the potential V A of the first node A is as shown in Equation 1-1:
  • V A V dd -V data +V th +V ref1 1-1
  • Equation 1-1 Substituting Equation 1-1 into the saturation current formula of the organic light emitting diode OLED, Equation 1-2 can be obtained:
  • I OLED K(V ref1 -V data ) 2 1-2
  • Equation 1-2 It can be known from Equation 1-2 that the saturation current of the organic light emitting diode OLED is no longer affected by the threshold voltage Vth of the driving transistor T4, thereby realizing the compensation of the current by the pixel compensation circuit, eliminating the influence of Vth .
  • the circuit further includes: a compensation switch tube T5, the source of the compensation switch tube T5 is connected to the second reference voltage V ref2 , and the gate of the compensation switch tube T5 is connected to the second control signal S2, the compensation switch tube
  • the drain of T5 is connected to the drain of the driving transistor T4 and the anode of the organic light emitting diode.
  • the first storage capacitor C1 is used to store the data when the data is written into the switch tube T1, and the first reset switch tube T2 and the compensation switch tube T5 are turned on.
  • the threshold voltage Vth of the transistor T4 is driven.
  • the level of the second control signal S2 can be set by the timing controller TCON to control the access of the second reference voltage V ref2 compared to the drain of the driving transistor T4 and the organic
  • the manner in which the second reference voltage V ref2 is input between the positive electrodes of the light emitting diodes OLED improves the convenience of operation.
  • the circuit further includes: a first control switch tube T6, a second control switch tube T7, and a third control switch tube T8.
  • the source of the first control switch tube T6 is connected to a power supply voltage V dd , the first The gate of the control switch T6 is connected to the third control signal S3, and the drain of the first control switch T6 is connected to the source of the drive transistor T4.
  • the source of the second control switch T7 is connected to the drain of the driving transistor T4 and the drain of the compensation switch T5, and the gate of the second control switch T7 is connected to the third control signal S3, the second control
  • the drain of the switching transistor T7 is connected to the anode of the organic light emitting diode.
  • the source of the third control switch T8 is connected to the second node B, the gate of the third control switch T8 is connected to the fourth control signal S4, and the drain of the third control switch T8 is connected to the first node A. .
  • the first storage capacitor C1 stores the threshold voltage Vth of the driving transistor T4
  • the first control switch T6, the second control switch T7 and the third control switch T8 are simultaneously turned on, so that the The organic light emitting diode OLED emits light.
  • the second control switch tube T7 and the third control switch tube T8 are simultaneously in an on state, the second control switch tube T7 is in a closed state, so that the organic light emitting diode OLED is not There is a current passing, thereby avoiding the problem of sneaking the organic light emitting diode OLED due to leakage.
  • the organic light emitting diode OLED may be an AMOLED, or may be other types of light emitting devices.
  • the first control signal S1, the second control signal S2, the third control signal S3 and the fourth control signal S4 are provided by the timing controller TCON.
  • the first reference voltage V ref1 and the second reference voltage V ref2 are preset constant voltages, and the first reference voltage V ref1 is greater than the data voltage written by the data line V data so that the organic light emitting diode can emit light normally.
  • the first reference voltage V ref1 when the first reference voltage V ref1 is preset, the set first reference voltage V ref1 is greater than the data voltage written by the data line V data .
  • the first reference voltage V ref1 may be increased.
  • the data is written into the switch tube T1, the first reset switch tube T2, the second reset switch tube T3, the compensation switch tube T4, the first control switch tube T5, and the second control switch tube T6.
  • the three control switch tubes T7 and the drive transistor T8 are each one of a polysilicon thin film transistor, an amorphous silicon thin film transistor, a zinc oxide based thin film transistor, and an organic thin film transistor. It should be understood that the data is written into the switch tube T1, the first reset switch tube T2, the second reset switch tube T3, the compensation switch tube T4, the first control switch tube T5, and the second control switch tube T6.
  • the third control switch T7 and the drive transistor T8 may belong to the same transistor type or different transistor types.
  • the switch transistors are organic thin film transistors; for example, the data write switch transistor T1 is polysilicon.
  • the thin film transistor, the first reset switch tube T2 is an amorphous silicon thin film transistor, the second reset switch tube T3 is a zinc oxide based thin film transistor, the compensation switch tube T4 is an organic thin film transistor, and the first control switch tube T5 is organic
  • the second control switch tube T6 is a polysilicon thin film transistor, the third control switch tube T7 is an organic thin film transistor, and the driving transistor T8 is a polysilicon transistor.
  • the pixel drive circuit has three phases of operation: a reset and data write phase, a compensation phase, and an illumination phase. These three phases will be described next.
  • the reset and data writing phase is to set the first control signal S1 and the scan signal Scan to a low level, the second control signal S2, the third control signal S3 and the fourth control signal S4 are placed at a high level . Therefore, the data is written into the switch tube T1, the first reset switch tube T2, and the second reset switch tube T3 is in an on state; the compensation switch tube T5, the first control switch tube T6, and the second control switch tube T7 and T8 of the third control switch in a closed state; the driving voltage at the gate of the transistor T4 is equal to the data voltage V data is written to the data line data.
  • FIG. 2 is a schematic structural diagram of an equivalent circuit of a resetting and data writing phase of a pixel driving circuit according to an embodiment of the present invention.
  • the first reference voltage V ref1 and the high level SW are input to the pixel driving circuit, and the first storage capacitor C1 releases the charge stored by itself, thereby preventing the residual charge of the previous stage of the light emitting process from interfering with the current illuminating process.
  • Data line Data write data voltage V data is written via the data switch transistor T1, a driving voltage at the gate of the transistor T4 is equal to the data voltage V data, i.e. the potential V A at the first node A as shown in Equation 1-3 :
  • V A V data 1-3
  • the data voltage Vdata is stored in the second storage capacitor C2.
  • the compensation phase is to set the scan signal Scan and the second control signal S2 to a low level, and the first control signal S1, the third control signal S3, and the fourth control signal S4 are placed at a high level. Therefore, the data is written into the switch tube T1, the first reset switch tube T2 and the compensation switch tube T5 are in an on state; the second reset switch tube T3, the first control switch tube T6, and the second control switch tube T7 And the third control switch T8 is in an off state; when the potential at the third node C is equal to the potential of the data voltage V data minus the threshold voltage V th of the driving transistor T4, the driving transistor T4 is in a off state.
  • FIG. 3 is a schematic structural diagram of an equivalent circuit of a compensation phase of a pixel driving circuit according to an embodiment of the present invention.
  • the first storage capacitor C1 discharges electric charge through the driving transistor T4 and the compensation switching tube T5.
  • the potential V C at the third node C is:
  • V C V data -V th 1-4
  • the threshold voltage Vth of the driving transistor T4 is stored in the first storage capacitor C1.
  • the illumination phase is to set the third control signal S3 and the fourth control signal S4 to a low level, and the first control signal S1, the second control signal S2 and the scan signal Scan are placed at a high level. Therefore, the first control switch tube T6, the second control switch tube T7 and the third control switch tube T8 are in an on state; the data is written into the switch tube T1, the first reset switch tube T2, and the second reset switch tube T3 and The compensation switch T5 is in a closed state; the gate-source voltage V gs of the driving transistor T4 drives the organic light-emitting diode OLED to emit light, and in the light-emitting phase, the gate-source voltage V gs of the driving transistor T4 remains unchanged until the next frame image is refreshed.
  • the second control switch tube T7 and the third control switch tube T8 are simultaneously in an on state, the second control switch tube T7 is in a closed state, so that the organic light emitting diode OLED is not There is a current passing, thereby avoiding the problem of sneaking the organic light emitting diode OLED due to leakage.
  • FIG. 4 is a schematic structural diagram of an equivalent circuit of an illuminating phase of a pixel driving circuit according to an embodiment of the present invention.
  • the power supply voltage V dd is written into the circuit through the first control switch T6, and the organic light emitting diode OLED is connected to the circuit through the second control switch T7, and the potential V C of the third node C is abrupt. for:
  • V C V dd 1-5
  • V A V ref1 1-6
  • V A -V ref1 V dd -(V data -V th ) 1-7
  • the potential V A of the first node A can be expressed as:
  • V A V dd -V data +V th +V ref1 1-8
  • the gate voltage V s of the driving transistor T4 is:
  • the source voltage V g of the driving transistor T4 is:
  • the gate-source voltage V gs of the driving transistor T4 is:
  • the saturation current through the organic light emitting diode OLED is:
  • I OLED K(V gs -V th ) 2 1-12
  • K is the parameter related to the driving transistor T4
  • V gs is the gate-source voltage of the driving transistor T4
  • V th is the threshold voltage of the driving transistor T4
  • the formula 1-11 is substituted into the formula 1-12, and the formula 1-13 can be obtained.
  • I OLED K(V ref1 -V data ) 2 1-13
  • Equation 1-13 It can be known from Equation 1-13 that in the light-emitting phase, the saturation current of the organic light-emitting diode OLED is no longer affected by the threshold voltage Vth of the driving transistor T6, thereby realizing the compensation of the current by the pixel compensation circuit, eliminating the Vth influences. Moreover, there is no power supply voltage V dd in the formula, thereby eliminating the influence of the power supply voltage V dd on the pixel compensation circuit and avoiding the problem of voltage drop IR-drop.
  • the threshold voltage Vth of the driving transistor T4 can be first stored in the first storage capacitor C1.
  • the saturation current formula of the organic light emitting diode OLED that the current flowing through the organic light emitting diode OLED is controlled by the first reference voltage V ref1 and the data voltage V data , so that the current flowing through the organic light emitting diode OLED is no longer affected
  • the effect of driving the threshold voltage Vth of the thin film transistor can compensate for the drift of the threshold voltage of the driving thin film transistor, thereby improving the uniformity of the display screen of the OLED and improving the display quality.
  • FIG. 5 it is a driving timing diagram of a pixel driving circuit according to an embodiment of the present invention.
  • the data connected to the scan signal Scan in FIG. 5 is written into the switch tube T1 and the first reset switch tube T2, the second reset switch tube T2 to which the first control signal S1 is connected, and the compensation switch tube to which the second control signal S2 is connected.
  • T5, the first control switch tube T6 and the third control switch tube T7 connected to the third control signal S3, and the third control switch tube T8 connected to the fourth control signal S4 are all active-low switch tubes, that is, when When these signals are low, the switches connected to these signals are in the on state.
  • the switch tubes connected to these signals can also be active-level switch tubes; the switch tubes connected to these signals can also be respectively different types of level-effective switch tubes, for example, data write switch tubes.
  • T1 and the first reset switch tube T2 are active-level switch tubes
  • the second reset switch tube T2 is an active-low switch tube
  • the compensation switch tube T5 is an active-high switch tube
  • the first control switch tube T6 and the third control switch tube T7 are active-low switch tubes
  • the third control switch tube T8 is an active-low switch tube
  • the switch tubes connected to the same signal must be switches of the same type level effective.
  • the data write switch transistor T1 and the first reset switch transistor T2 connected to the scan signal Scan must be the same type of active switch.
  • the scan signal Scan and the first control signal S1 are active levels, and the second control signal S2, the third control signal S3, and the fourth control signal S4 are inactive levels;
  • the scan signal Scan and the second control signal S2 are active levels, the first control signal S1, the third control signal S3 and the fourth control signal S4 are inactive levels;
  • the third control signal S3 and The fourth control signal S4 is an active level, and the first control signal S1, the first control signal S2, and the scan signal Scan are inactive levels.
  • the working process of the driving sequence can refer to the working process of the pixel driving circuit described in FIG. 1 , and details are not described herein again.
  • the threshold voltage V th of the driving transistor T4 can be first stored in the first storage capacitor.
  • the saturation current can be derived from the formula of an organic light emitting diode OLED flowing through the organic light emitting diode OLED is a current and the first reference voltage V ref1 is controlled by a data voltage V data, so that the current flowing through the organic light emitting diode OLED is not Further, affected by the threshold voltage Vth of the driving thin film transistor, the drift of the threshold voltage of the driving thin film transistor can be compensated, thereby improving the uniformity of the OLED display screen and improving the display quality.
  • liquid crystal display device including the pixel driving circuit described in the method embodiment shown in FIG. 1 is provided.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Electroluminescent Light Sources (AREA)
  • Control Of El Displays (AREA)
  • Control Of Indicators Other Than Cathode Ray Tubes (AREA)

Abstract

一种像素驱动电路及有机发光二极管显示装置，像素驱动电路包括：数据写入开关管(T1)、第一复位开关管(T2)、第二复位开关管(T3)、驱动晶体管(T4)、有机发光二极管(OLED)、以及第一存储电容(C1)和第二存储电容(C2)，可以补偿驱动晶体管(T4)阈值电压(V th)的漂移，提升显示品质。

Description

[根据细则37.2由ISA制定的发明名称]　一种像素驱动电路及有机发光二极管显示装置 技术领域
本发明涉及显示技术领域，尤其涉及一种像素驱动电路及液晶显示装置。
背景技术
有机发光二极管(organic light emitting diode，OLED)显示装置具有低功耗、高色域、高亮度、高分辨率、宽视角、高响应速度等优点。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。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，即采用两个薄膜晶体管加一个电容的结构将电压变换为电流。
传统用于AMOLED的2T1C像素驱动电路对薄膜晶体管的阈值电压和沟道迁移率、有机发光二极管的启动电压和量子效率以及供电电源的瞬变过程都很敏感。驱动薄膜晶体管的阈值电压会随着工作时间而漂移，从而导致有机发光二极管的发光不稳定，引起像素驱动电路的亮度差异，降低显示品质。
发明内容
本发明实施例提供一种像素驱动电路及液晶显示装置，可以补偿驱动薄膜晶体管阈值电压的漂移，提升显示品质。
第一方面，本发明实施例提供了一种像素驱动电路，该电路包括数据写入开关管、第一复位开关管、第二复位开关管、驱动晶体管、有机发光二极管OLED、以及第一存储电容和第二存储电容；
该数据写入开关管的源极接数据线，该数据写入开关管的漏极接第一节点；
该第一复位开关管的源极接第一参考电压，该第一复位开关管的漏极接第二节点；
该第二复位开关管的源极接高电平，该第二复位开关管的漏极接第三节点；
该驱动晶体管的栅极接该第一节点，该驱动晶体管的源极接该第三节点，该驱动晶体管的漏极接该有机发光二极管的正极；
该第一存储电容的第一端接该第三节点，该第一存储电容的第二端接该第二节点；
该第二存储电容的第一端接该第二节点，该第二存储电容的第二端接该第一节点。
结合第一方面，在第一方面的第一种可能的实现方式中，该电路还包括：该第一复位开关管和该数据写入开关管的栅极均接扫描控制线，该第二复位开关管的栅极接第一控制信号，该数据线用于在该数据写入开关管，该第一复位开关管和该第二复位开关管导通时，写入数据电压，以使该第二存储电容存储该数据电压。
结合第一方面，或者在第一方面的上述任一可能的实现方式中，在第一方面的第二种可能的实现方式中，该电路还包括：补偿开关管，该补偿开关管的源极接第二参考电压，该补偿开关管的栅极接第二控制信号，该补偿开关管的漏极接该驱动晶体管的漏极和该有机发光二极管的正极；该第二存储电容存储该数据电压之后，该第一存储电容用于在该数据写入开关管，该第一复位开关管和该补偿开关管导通时，存储该驱动晶体管的阈值电压。
结合第一方面，或者在第一方面的上述任一可能的实现方式中，在第一方面的第三种可能的实现方式中，该电路还包括：第一控制开关管，第二控制开关管和第三控制开关管，该第一控制开关管的源极接电源电压，该第一控制开关管的栅极接第三控制信号，该第一控制开关管的漏极接该驱动晶体管的源极；
该第二控制开关管的源极接该驱动晶体管的漏极和该补偿开关管的漏极，该第二控制开关管的栅极接该第三控制信号，该第二控制开关管的漏极接该有机发光二极管的正极；
该第三控制开关管的源极接该第二节点，该第三控制开关管的栅极接第四 控制信号，该第三控制开关管的漏极接该第一节点；
该第一存储电容存储该驱动晶体管的阈值电压之后，该第一控制开关管，该第二控制开关管和该第三控制开关管同时处于导通状态，以使该有机发光二极管OLED发光。
第二方面，本发明实施例提供了一种液晶显示装置，该液晶显示装置包括上述第一方面或者第一方面的任一可能的实现方式所描述的像素驱动电路。
在本发明实施例中，由于该第一存储电容的第一端接该第三节点，该第一存储电容的第二端接该第二节点，该第二存储电容的第一端接该第二节点，该第二存储电容的第二端接该第一节点，所以可以把驱动晶体管的阈值电压先储存在第一存储电容中，由有机发光二极管OLED的饱和电流公式可以得出，流经有机发光二极管OLED的电流由第一参考电压和数据电压控制，从而使得流经该有机发光二极管OLED的电流不再受驱动薄膜晶体管的阈值电压的影响，可以补偿驱动薄膜晶体管阈值电压的漂移，从而提高OLED显示画面的均一性，提升显示品质。
附图说明
为了更清楚地说明本发明实施例技术方案，下面将对实施例描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。
图1是本发明实施例提供的一种像素驱动电路的结构示意图；
图2是本发明实施例提供的一种像素驱动电路的复位和数据写入阶段的等效电路图；
图3是本发明实施例提供的一种像素驱动电路的补偿阶段的等效电路图；
图4是本发明实施例提供的一种像素驱动电路的发光阶段的等效电路图；
图5是本发明实施例提供的一种像素驱动电路的驱动时序图。
具体实施方式
下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清 楚、完整地描述，显然，所描述的实施例是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。
应当理解，当在本说明书和所附权利要求书中使用时，术语“包括”和“包含”指示所描述特征、整体、步骤、操作、元素和/或组件的存在，但并不排除一个或多个其它特征、整体、步骤、操作、元素、组件和/或其集合的存在或添加。
还应当理解，在此本发明说明书中所使用的术语仅仅是出于描述特定实施例的目的而并不意在限制本发明。如在本发明说明书和所附权利要求书中所使用的那样，除非上下文清楚地指明其它情况，否则单数形式的“一”、“一个”及“该”意在包括复数形式。
还应当进一步理解，在本发明说明书和所附权利要求书中使用的术语“和/或”是指相关联列出的项中的一个或多个的任何组合以及所有可能组合，并且包括这些组合。
如在本说明书和所附权利要求书中所使用的那样，术语“如果”可以依据上下文被解释为“当…时”或“一旦”或“响应于确定”或“响应于检测到”。类似地，短语“如果确定”或“如果检测到[所描述条件或事件]”可以依据上下文被解释为意指“一旦确定”或“响应于确定”或“一旦检测到[所描述条件或事件]”或“响应于检测到[所描述条件或事件]”。
参见图1，是本发明实施例提供一种像素驱动电路图，该电路包括数据写入开关管T1、第一复位开关管T2、第二复位开关管T3、驱动晶体管T4、有机发光二极管OLED、以及第一存储电容C1和第二存储电容C2。
该数据写入开关管T1的源极接数据线Data，该数据写入开关管T1的漏极接第一节点A。
该第一复位开关管T2的源极接第一参考电压V ref1，该第一复位开关管T2的漏极接第二节点B。
该第二复位开关管T3的源极接高电平SW，该第二复位开关管T3的漏极接第三节点C。
该驱动晶体管T4的栅极接该第一节点A，该驱动晶体管T5的源极接该 第三节点C，该驱动晶体管T5的漏极接该有机发光二极管的正极。
该第一存储电容C1的第一端接该第三节点C，该第一存储电容C1的第二端接该第二节点B。该第一存储电容C1有两端，该第一存储电容C1的一端称为第一端，该第一存储电容C1的另一端称为第二端。
该第二存储电容C2的第一端接该第二节点B，该第二存储电容C1的第二端接该第一节点A。该第二存储电容C1有两端，该第二存储电容C1的一端称为第一端，该第二存储电容C1的另一端称为第二端。
其中，该电路还包括：该第一复位开关管T2和该数据写入开关管T1的栅极均接扫描控制线Scan，该第二复位开关管T3的栅极接第一控制信号S1。首先，该数据线Data用于在该数据写入开关管T1，该第一复位开关管T2和该第二复位开关管T3导通时，写入数据电压V data，以使该第二存储电容C2存储该数据电压V data。接下来，在驱动晶体管T4的漏极和该有机发光二极管OLED的正极之间输入第二参考电压V ref2，使得第三节点C的电位V C等于数据电压V data减去驱动晶体管T4的阈值电压V th的电压差，从而将该驱动晶体管T4的阈值电压V th存储在该第一存储电容C1中。最后，在第三节点C处输入电源电压V dd，短接该第二存储电容C2，使得第一节点A的电位V A如公式1-1所示：
V A＝V dd-V data+V th+V ref1       1-1
将公式1-1代入有机发光二极管OLED的饱和电流公式，可以得到公式1-2：
I OLED＝K(V ref1-V data) 2         1-2
由公式1-2可以知道，有机发光二极管OLED的饱和电流不再受驱动晶体管T4的阈值电压V th的影响，从而实现了该像素补偿电路对电流的补偿，消除了V th的影响。
可选的，该电路还可以包括：补偿开关管T5，该补偿开关管T5的源极接第二参考电压V ref2，该补偿开关管T5的栅极接第二控制信号S2，该补偿开关管T5的漏极接该驱动晶体管T4的漏极和该有机发光二极管的正极。
该第二存储电容C2存储该数据电压V data之后，该第一存储电容C1用于在该数据写入开关管T1，该第一复位开关管T2和该补偿开关管T5导通时，存储 该驱动晶体管T4的阈值电压V th。
由于补偿开关管T5的接入，可以通过时序控制器TCON设置第二控制信号S2的电平从而控制第二参考电压V ref2的接入，相比于人工在驱动晶体管T4的漏极和该有机发光二极管OLED的正极之间输入第二参考电压V ref2的方式，提升了操作的便利性。
可选的，该电路还可以包括：第一控制开关管T6，第二控制开关管T7和第三控制开关管T8，该第一控制开关管T6的源极接电源电压V dd，该第一控制开关管T6的栅极接第三控制信号S3，该第一控制开关管T6的漏极接该驱动晶体管T4的源极。该第二控制开关管T7的源极接该驱动晶体管T4的漏极和该补偿开关管T5的漏极，该第二控制开关管T7的栅极接该第三控制信号S3，该第二控制开关管T7的漏极接该有机发光二极管的正极。该第三控制开关管T8的源极接该第二节点B，该第三控制开关管T8的栅极接第四控制信号S4，该第三控制开关管T8的漏极接该第一节点A。
该第一存储电容C1存储该驱动晶体管T4的阈值电压V th之后，该第一控制开关管T6，该第二控制开关管T7和该第三控制开关管T8同时处于导通状态，以使该有机发光二极管OLED发光。
该第一控制开关管T6，该第二控制开关管T7和该第三控制开关管T8同时处于导通状态之前，该第二控制开关管T7处于关闭状态，以使该有机发光二极管OLED中不存在电流通过，从而避免了由于漏电引起的有机发光二极管OLED的偷亮问题。
具体地，有机发光二极管OLED可以是AMOLED，也可以是其他类型的发光器件。具体地，该第一控制信号S1、该第二控制信号S2，该第三控制信号S3和该第四控制信号S4由时序控制器TCON提供。该第一参考电压V ref1和第二参考电压V ref2为预设的恒定电压，该第一参考电压V ref1大于数据线V data写入的数据电压，以便该有机发光二极管可以正常发光。可选的，预设第一参考电压V ref1时，设置的第一参考电压V ref1比数据线V data写入的数据电压大。可选的，若需要得到可调节范围较大的数据电压时，可增大该第一参考电压V ref1。
其中，该数据写入开关管T1、该第一复位开关管T2、该第二复位开关管T3、该补偿开关管T4、该第一控制开关管T5、该第二控制开关管T6，该第 三控制开关管T7和该驱动晶体管T8均属于多晶硅薄膜晶体管、非晶硅薄膜晶体管、氧化锌基薄膜晶体管和有机薄膜晶体管中的一种。需要理解的是，该数据写入开关管T1、该第一复位开关管T2、该第二复位开关管T3、该补偿开关管T4、该第一控制开关管T5、该第二控制开关管T6，该第三控制开关管T7和该驱动晶体管T8可以属于相同的晶体管类型，也可以属于不同的晶体管类型，例如，这些开关管均为有机薄膜晶体管；再如，数据写入开关管T1为多晶硅薄膜晶体管，该第一复位开关管T2为非晶硅薄膜晶体管，该第二复位开关管T3为氧化锌基薄膜晶体管，该补偿开关管T4为有机薄膜晶体管，该第一控制开关管T5为有机薄膜晶体管，该第二控制开关管T6为多晶硅薄膜晶体管，该第三控制开关管T7为有机薄膜晶体管，该驱动晶体管T8为多晶硅晶体管。
该像素驱动电路有三个工作阶段：复位和数据写入阶段、补偿阶段和发光阶段。接下来将对这三个阶段进行描述。
复位和数据写入阶段是将该第一控制信号S1和该扫描信号Scan置于低电平，该第二控制信号S2，该第三控制信号S3和该第四控制信号S4置于高电平。因此，该数据写入开关管T1、该第一复位开关管T2、该第二复位开关管T3为导通状态；该补偿开关管T5、该第一控制开关管T6，该第二控制开关管T7和该第三控制开关管T8为关闭状态；驱动晶体管T4的栅极处的电压等于数据线Data写入的数据电压V data。
参见图2，是本发明实施例提供的一种像素驱动电路的复位和数据写入阶段的等效电路的结构示意图。如图2所示，第一参考电压V ref1和高电平SW输入该像素驱动电路，该第一存储电容C1释放自身存储的电荷，避免上一阶段发光过程残余的电荷干扰本次发光过程。数据线Data通过数据写入开关管T1写入数据电压V data，驱动晶体管T4的栅极处的电压等于该数据电压V data，即第一节点A处的电位V A如公式1-3所示：
V A＝V data           1-3
从公式1-3中得出，该数据电压V data存储在第二存储电容C2中。
补偿阶段是将该扫描信号Scan和第二控制信号S2置于低电平，该第一控制信号S1，第三控制信号S3和第四控制信号S4置于高电平。因此，该数据写入 开关管T1，该第一复位开关管T2和补偿开关管T5为导通状态；该第二复位开关管T3、该第一控制开关管T6，该第二控制开关管T7和该第三控制开关管T8为关闭状态；当第三节点C处的电位等于数据电压V data减去驱动晶体管T4的阈值电压V th的电位时，驱动晶体管T4处于关闭状态。
参见图3，是本发明实施例提供的一种像素驱动电路的补偿阶段的等效电路的结构示意图。如图3所示，第一存储电容C1通过驱动晶体管T4和补偿开关管T5释放电荷，释放完毕后，第三节点C处的电位V C为：
V C＝V data-V th           1-4
因此，该驱动晶体管T4的阈值电压V th存储在该第一存储电容C1中。
发光阶段是将该第三控制信号S3和该第四控制信号S4置于低电平，该第一控制信号S1，第二控制信号S2和该扫描信号Scan置于高电平。因此，该第一控制开关管T6，第二控制开关管T7和第三控制开关管T8为导通状态；该数据写入开关管T1、第一复位开关管T2，第二复位开关管T3和补偿开关管T5为关闭状态；驱动晶体管T4的栅源电压V gs驱动有机发光二极管OLED发光，在发光阶段，驱动晶体管T4的栅源电压V gs保持不变，直到下一帧图像刷新。
该第一控制开关管T6，该第二控制开关管T7和该第三控制开关管T8同时处于导通状态之前，该第二控制开关管T7处于关闭状态，以使该有机发光二极管OLED中不存在电流通过，从而避免了由于漏电引起的有机发光二极管OLED的偷亮问题。
参见图4，是本发明实施例提供的一种像素驱动电路的发光阶段的等效电路的结构示意图。如图4所示，电源电压V dd通过该第一控制开关管T6写入该电路，该有机发光二极管OLED通过该第二控制开关管T7与该电路连通，第三节点C的电位V C突变为：
V C＝V dd           1-5
由于第三控制开关管T8为导通状态，该第二存储电容C2被短接，从而使得第一节点A的电位V A突变为：
V A＝V ref1         1-6
因为第一节点A和第三节点C的电位变化值相等，从而有：
V A-V ref1＝V dd-(V data-V th)         1-7
即第一节点A的电位V A可以表示为：
V A＝V dd-V data+V th+V ref1           1-8
从而，驱动晶体管T4的栅极电压V s为：
V s＝V A＝V dd-V data+V th+V ref1           1-9
驱动晶体管T4的源极电压V g为：
V g＝V C＝V dd            1-10
驱动晶体管T4的栅源电压V gs为：
V gs＝V g-V s＝V ref1-V data+V th         1-11
通过有机发光二极管OLED的饱和电流为：
I OLED＝K(V gs-V th) 2           1-12
其中，K为与驱动晶体管T4相关的参数，V gs为驱动晶体管T4的栅源电压，V th为驱动晶体管T4的阈值电压，将公式1-11代入公式1-12，可以得到公式1-13：
I OLED＝K(V ref1-V data) 2            1-13
由公式1-13可以知道，在发光阶段，有机发光二极管OLED的饱和电流不再受驱动晶体管T6的阈值电压V th的影响，从而实现了该像素补偿电路对电流的补偿，消除了V th的影响。并且，该公式中没有电源电压V dd，从而消除了电源电压V dd对该像素补偿电路的影响，避免了电压降IR-drop的问题。
在图1所示的像素驱动电路中，由于该第一存储电容C1的第一端接该第三节点C，该第一存储电容C1的第二端接该第二节点B，该第二存储电容C2的第一端接该第二节点B，该第二存储电容C1的第二端接该第一节点A，所以可以把驱动晶体管T4的阈值电压V th先储存在第一存储电容C1中，由有机发光二极管OLED的饱和电流公式可以得出，流经有机发光二极管OLED的电流由第一参考电压V ref1和数据电压V data控制，从而使得流经该有机发光二极管OLED的电流不再受驱动薄膜晶体管的阈值电压V th的影响，可以补偿驱动薄膜晶体管阈值电压的漂移，从而提高OLED显示画面的均一性，提升显示品质。
参见图5，是本发明实施例提供的一种像素驱动电路的驱动时序图。图5中的扫描信号Scan所连接的数据写入开关管T1和第一复位开关管T2，第一控制信号S1所连接的第二复位开关管T2，第二控制信号S2所连接的补偿开关管 T5，第三控制信号S3所连接的第一控制开关管T6和第三控制开关管T7，第四控制信号S4所连接的第三控制开关管T8均为低电平有效的开关管，即当这些信号为低电平时，这些信号所连接的开关管处于导通状态。
需要理解的是，这些信号所连接的开关管也可以为高电平有效的开关管；这些信号所连接的开关管也可以分别为不同类型电平有效的开关管，例如，数据写入开关管T1和第一复位开关管T2为高电平有效的开关管，第二复位开关管T2为低电平有效的开关管，补偿开关管T5为高电平有效的开关管，第一控制开关管T6和第三控制开关管T7为低电平有效的开关管，第三控制开关管T8为低电平有效的开关管，但连接于同一信号的开关管必须为同种类型电平有效的开关管，例如，连接于扫描信号Scan的数据写入开关管T1和第一复位开关管T2必须为同种类型电平有效的开关管。
如图5所示：在复位和数据写入阶段，扫描信号Scan和第一控制信号S1为有效电平，第二控制信号S2，第三控制信号S3和第四控制信号S4为无效电平；在补偿阶段，扫描信号Scan和第二控制信号S2为有效电平，第一控制信号S1，第三控制信号S3和第四控制信号S4为无效电平；在发光阶段，第三控制信号S3和第四控制信号S4为有效电平，第一控制信号S1，第一控制信号S2和扫描信号Scan为无效电平。驱动时序的工作过程可参考图1所描述的像素驱动电路的工作过程，这里不再赘述。
在图5所示的像素驱动电路时序图中，由于该第一存储电容C1的第一端接该第三节点C，该第一存储电容C1的第二端接该第二节点B，该第二存储电容C2的第一端接该第二节点B，该第二存储电容C1的第二端接该第一节点A，所以可以把驱动晶体管T4的阈值电压V th先储存在第一存储电容C1中，由有机发光二极管OLED的饱和电流公式可以得出，流经有机发光二极管OLED的电流由第一参考电压V ref1和数据电压V data控制，从而使得流经该有机发光二极管OLED的电流不再受驱动薄膜晶体管的阈值电压V th的影响，可以补偿驱动薄膜晶体管阈值电压的漂移，从而提高OLED显示画面的均一性，提升显示品质。
在本发明的另一实施例中提供一种液晶显示装置，该显示装置包含图1所示方法实施例所描述的像素驱动电路。
综上所述，虽然本发明已以较佳实施例揭露如上，但所述较佳实施例并非 用以限制本发明，该领域的普通技术人员，在不脱离本发明的精神和范围内，均可作各种更动与润饰，因此本发明的保护范围以权利要求界定的范围为准。
以上所述是本发明的优选实施方式，应当指出，对于本技术领域的普通技术人员来说，在不脱离本发明原理的前提下，还可以做出若干改进和润饰，这些改进和润饰也视为本发明的保护范围。

Claims (18)

  1. 一种像素驱动电路，其中，所述电路包括数据写入开关管(T1)、第一复位开关管(T2)、第二复位开关管(T3)、驱动晶体管(T4)、有机发光二极管OLED、以及第一存储电容(C1)和第二存储电容(C2)；
    所述数据写入开关管(T1)的源极接数据线(Data)，所述数据写入开关管(T1)的漏极接第一节点(A)；
    所述第一复位开关管(T2)的源极接第一参考电压(V ref1)，所述第一复位开关管(T2)的漏极接第二节点(B)；
    所述第二复位开关管(T3)的源极接高电平(SW)，所述第二复位开关管(T3)的漏极接第三节点(C)；
    所述驱动晶体管(T4)的栅极接所述第一节点(A)，所述驱动晶体管(T5)的源极接所述第三节点(C)，所述驱动晶体管(T5)的漏极接所述有机发光二极管的正极；
    所述第一存储电容(C1)的第一端接所述第三节点(C)，所述第一存储电容(C1)的第二端接所述第二节点(B)；
    所述第二存储电容(C2)的第一端接所述第二节点(B)，所述第二存储电容(C1)的第二端接所述第一节点(A)。
  2. 根据权利要求1所述的电路，其中，所述第一复位开关管(T2)和所述数据写入开关管(T1)的栅极均接扫描控制线(Scan)，所述第二复位开关管(T3)的栅极接第一控制信号(S1)，所述数据线(Data)用于在所述数据写入开关管(T1)，所述第一复位开关管(T2)和所述第二复位开关管(T3)导通时，写入数据电压(V data)，以使所述第二存储电容(C2)存储所述数据电压(V data)。
  3. 根据权利要求2所述的电路，其中，所述电路还包括补偿开关管(T5)，所述补偿开关管(T5)的源极接第二参考电压(V ref2)，所述补偿开关管(T5)的栅极接第二控制信号(S2)，所述补偿开关管(T5)的漏极接所述驱动晶体管(T4)的漏极和所述有机发光二极管的正极；所述第二存储电容(C2)存储所述数据电压(V data)之后，所述第一存储电容(C1)用于在所述数据写 入开关管(T1)，所述第一复位开关管(T2)和所述补偿开关管(T5)导通时，存储所述驱动晶体管(T4)的阈值电压(V th)。
  4. 根据权利要求1所述的电路，其中，所述电路还包括第一控制开关管(T6)，第二控制开关管(T7)和第三控制开关管(T8)，所述第一控制开关管(T6)的源极接电源电压(V dd)，所述第一控制开关管(T6)的栅极接第三控制信号(S3)，所述第一控制开关管(T6)的漏极接所述驱动晶体管(T4)的源极；
    所述第二控制开关管(T7)的源极接所述驱动晶体管(T4)的漏极和所述补偿开关管(T5)的漏极，所述第二控制开关管(T7)的栅极接所述第三控制信号(S3)，所述第二控制开关管(T7)的漏极接所述有机发光二极管的正极；
    所述第三控制开关管(T8)的源极接所述第二节点(B)，所述第三控制开关管(T8)的栅极接第四控制信号(S4)，所述第三控制开关管(T8)的漏极接所述第一节点(A)；
    所述第一存储电容(C1)存储所述驱动晶体管(T4)的阈值电压(V th)之后，所述第一控制开关管(T6)，所述第二控制开关管(T7)和所述第三控制开关管(T8)同时处于导通状态，以使所述有机发光二极管OLED发光。
  5. 根据权利要求4所述的电路，其中，所述第一控制开关管(T6)，所述第二控制开关管(T7)和所述第三控制开关管(T8)同时处于导通状态之前，所述第二控制开关管(T7)处于关闭状态，以使所述有机发光二极管OLED中不存在电流通过。
  6. 根据权利要求1所述的电路，其中，所述第一参考电压(V ref1)大于所述数据电压(V data)。
  7. 根据权利要求1所述的电路，其中，所述数据写入开关管(T1)、所述第一复位开关管(T2)、所述第二复位开关管(T3)、所述驱动晶体管(T4)、所述补偿开关管(T5)、所述第一控制开关管(T6)，所述第二控制开关管(T7)和所述第三控制开关管(T8)均属于多晶硅薄膜晶体管、非晶硅薄膜晶体管、氧化锌基薄膜晶体管和有机薄膜晶体管中的一种。
  8. 根据权利要求1所述的电路，其中，所述第一控制信号(S1)、所述第二控制信号(S2)，所述第三控制信号(S3)和所述第四控制信号(S4)由时 序控制器TCON提供。
  9. 根据权利要求1所述的电路，其中，所述第一参考电压(V ref1)和第二参考电压(V ref2)为预设的恒定电压。
  10. 一种液晶显示装置，其中，所述液晶显示装置包含像素驱动电路，其中，所述电路包括数据写入开关管(T1)、第一复位开关管(T2)、第二复位开关管(T3)、驱动晶体管(T4)、有机发光二极管OLED、以及第一存储电容(C1)和第二存储电容(C2)；
    所述数据写入开关管(T1)的源极接数据线(Data)，所述数据写入开关管(T1)的漏极接第一节点(A)；
    所述第一复位开关管(T2)的源极接第一参考电压(V ref1)，所述第一复位开关管(T2)的漏极接第二节点(B)；
    所述第二复位开关管(T3)的源极接高电平(SW)，所述第二复位开关管(T3)的漏极接第三节点(C)；
    所述驱动晶体管(T4)的栅极接所述第一节点(A)，所述驱动晶体管(T5)的源极接所述第三节点(C)，所述驱动晶体管(T5)的漏极接所述有机发光二极管的正极；
    所述第一存储电容(C1)的第一端接所述第三节点(C)，所述第一存储电容(C1)的第二端接所述第二节点(B)；
    所述第二存储电容(C2)的第一端接所述第二节点(B)，所述第二存储电容(C1)的第二端接所述第一节点(A)。
  11. 根据权利要求10所述的液晶显示装置，其中，所述第一复位开关管(T2)和所述数据写入开关管(T1)的栅极均接扫描控制线(Scan)，所述第二复位开关管(T3)的栅极接第一控制信号(S1)，所述数据线(Data)用于在所述数据写入开关管(T1)，所述第一复位开关管(T2)和所述第二复位开关管(T3)导通时，写入数据电压(V data)，以使所述第二存储电容(C2)存储所述数据电压(V data)。
  12. 根据权利要求11所述的液晶显示装置，其中，所述电路还包括补偿开关管(T5)，所述补偿开关管(T5)的源极接第二参考电压(V ref2)，所述补偿开关管(T5)的栅极接第二控制信号(S2)，所述补偿开关管(T5)的漏极接 所述驱动晶体管(T4)的漏极和所述有机发光二极管的正极；所述第二存储电容(C2)存储所述数据电压(V data)之后，所述第一存储电容(C1)用于在所述数据写入开关管(T1)，所述第一复位开关管(T2)和所述补偿开关管(T5)导通时，存储所述驱动晶体管(T4)的阈值电压(V th)。
  13. 根据权利要求10所述的液晶显示装置，其中，所述电路还包括第一控制开关管(T6)，第二控制开关管(T7)和第三控制开关管(T8)，所述第一控制开关管(T6)的源极接电源电压(V dd)，所述第一控制开关管(T6)的栅极接第三控制信号(S3)，所述第一控制开关管(T6)的漏极接所述驱动晶体管(T4)的源极；
    所述第二控制开关管(T7)的源极接所述驱动晶体管(T4)的漏极和所述补偿开关管(T5)的漏极，所述第二控制开关管(T7)的栅极接所述第三控制信号(S3)，所述第二控制开关管(T7)的漏极接所述有机发光二极管的正极；
    所述第三控制开关管(T8)的源极接所述第二节点(B)，所述第三控制开关管(T8)的栅极接第四控制信号(S4)，所述第三控制开关管(T8)的漏极接所述第一节点(A)；
    所述第一存储电容(C1)存储所述驱动晶体管(T4)的阈值电压(V th)之后，所述第一控制开关管(T6)，所述第二控制开关管(T7)和所述第三控制开关管(T8)同时处于导通状态，以使所述有机发光二极管OLED发光。
  14. 根据权利要求13所述的液晶显示装置，其中，所述第一控制开关管(T6)，所述第二控制开关管(T7)和所述第三控制开关管(T8)同时处于导通状态之前，所述第二控制开关管(T7)处于关闭状态，以使所述有机发光二极管OLED中不存在电流通过。
  15. 根据权利要求10所述的液晶显示装置，其中，所述第一参考电压(V ref1)大于所述数据电压(V data)。
  16. 根据权利要求10所述的液晶显示装置，其中，所述数据写入开关管(T1)、所述第一复位开关管(T2)、所述第二复位开关管(T3)、所述驱动晶体管(T4)、所述补偿开关管(T5)、所述第一控制开关管(T6)，所述第二控制开关管(T7)和所述第三控制开关管(T8)均属于多晶硅薄膜晶体管、非晶硅薄膜晶体管、 氧化锌基薄膜晶体管和有机薄膜晶体管中的一种。
  17. 根据权利要求10所述的液晶显示装置，其中，所述第一控制信号(S1)、所述第二控制信号(S2)，所述第三控制信号(S3)和所述第四控制信号(S4)由时序控制器TCON提供。
  18. 根据权利要求10所述的液晶显示装置，其中，所述第一参考电压(V ref1)和第二参考电压(V ref2)为预设的恒定电压。
PCT/CN2017/117170 2017-11-10 2017-12-19 一种像素驱动电路及有机发光二极管显示装置 Ceased WO2019090907A1 (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US15/754,218 US10650740B2 (en) 2017-11-10 2017-12-19 Pixel driving circuit and display device

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201711127680.3A CN107808636B (zh) 2017-11-10 2017-11-10 一种像素驱动电路及液晶显示装置
CN201711127680.3 2017-11-10

Publications (1)

Publication Number Publication Date
WO2019090907A1 true WO2019090907A1 (zh) 2019-05-16

Family

ID=61580101

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2017/117170 Ceased WO2019090907A1 (zh) 2017-11-10 2017-12-19 一种像素驱动电路及有机发光二极管显示装置

Country Status (3)

Country Link
US (1) US10650740B2 (zh)
CN (1) CN107808636B (zh)
WO (1) WO2019090907A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114495822A (zh) * 2021-12-27 2022-05-13 昆山国显光电有限公司 像素电路及其驱动方法和显示面板

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109102775B (zh) * 2018-08-31 2021-02-02 武汉天马微电子有限公司 有机发光二极管补偿电路、显示面板和显示装置
TWI674566B (zh) 2018-09-05 2019-10-11 友達光電股份有限公司 畫素電路與高亮度顯示器
TWI718909B (zh) * 2020-03-19 2021-02-11 友達光電股份有限公司 畫素驅動電路
CN111402821B (zh) * 2020-04-27 2021-09-03 杭州领挚科技有限公司 一种led背光板及制备毫米级以下led背光板的方法
CN111583870A (zh) * 2020-05-15 2020-08-25 武汉华星光电半导体显示技术有限公司 像素驱动电路
TWI758045B (zh) 2020-12-30 2022-03-11 友達光電股份有限公司 顯示裝置
CN115803884A (zh) 2021-06-29 2023-03-14 京东方科技集团股份有限公司 阵列基板和显示装置
US12002398B2 (en) * 2021-12-01 2024-06-04 Innolux Corporation Electronic device
TWI801080B (zh) * 2022-01-05 2023-05-01 友達光電股份有限公司 畫素驅動裝置
CN116416940B (zh) * 2023-06-07 2023-08-11 惠科股份有限公司 显示驱动电路、显示驱动方法及显示面板
CN118053388A (zh) * 2024-01-29 2024-05-17 云谷（固安）科技有限公司 像素驱动电路和显示面板
WO2025200642A1 (zh) * 2024-03-28 2025-10-02 京东方科技集团股份有限公司 一种像素驱动电路及显示基板
CN119418659A (zh) * 2024-09-27 2025-02-11 成都九天画芯科技有限公司 一种带有Vth自补偿的像素驱动电路

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20070032448A (ko) * 2005-09-16 2007-03-22 삼성에스디아이 주식회사 유기 전계발광 표시장치의 화소회로
CN101908316A (zh) * 2009-06-05 2010-12-08 三星移动显示器株式会社 像素及使用该像素的有机发光显示器
CN102982767A (zh) * 2012-12-10 2013-03-20 京东方科技集团股份有限公司 一种像素单元驱动电路、驱动方法及显示装置
CN103310732A (zh) * 2013-06-09 2013-09-18 京东方科技集团股份有限公司 一种像素电路及其驱动方法、显示装置
CN103460276A (zh) * 2011-08-09 2013-12-18 松下电器产业株式会社 图像显示装置
CN104700778A (zh) * 2015-03-27 2015-06-10 深圳市华星光电技术有限公司 Amoled像素驱动电路及像素驱动方法
CN105096819A (zh) * 2015-04-21 2015-11-25 北京大学深圳研究生院 一种显示装置及其像素电路

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR102524459B1 (ko) * 2015-08-27 2023-04-25 삼성디스플레이 주식회사 화소 및 그의 구동방법
CN107342051B (zh) * 2017-09-07 2019-11-05 京东方科技集团股份有限公司 一种像素电路、显示装置、像素电路驱动方法
CN107369413B (zh) * 2017-09-22 2021-04-23 京东方科技集团股份有限公司 一种像素补偿电路、其驱动方法、显示面板及显示装置

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20070032448A (ko) * 2005-09-16 2007-03-22 삼성에스디아이 주식회사 유기 전계발광 표시장치의 화소회로
CN101908316A (zh) * 2009-06-05 2010-12-08 三星移动显示器株式会社 像素及使用该像素的有机发光显示器
CN103460276A (zh) * 2011-08-09 2013-12-18 松下电器产业株式会社 图像显示装置
CN102982767A (zh) * 2012-12-10 2013-03-20 京东方科技集团股份有限公司 一种像素单元驱动电路、驱动方法及显示装置
CN103310732A (zh) * 2013-06-09 2013-09-18 京东方科技集团股份有限公司 一种像素电路及其驱动方法、显示装置
CN104700778A (zh) * 2015-03-27 2015-06-10 深圳市华星光电技术有限公司 Amoled像素驱动电路及像素驱动方法
CN105096819A (zh) * 2015-04-21 2015-11-25 北京大学深圳研究生院 一种显示装置及其像素电路

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114495822A (zh) * 2021-12-27 2022-05-13 昆山国显光电有限公司 像素电路及其驱动方法和显示面板

Also Published As

Publication number Publication date
CN107808636B (zh) 2020-09-04
US20190385521A1 (en) 2019-12-19
US10650740B2 (en) 2020-05-12
CN107808636A (zh) 2018-03-16

Similar Documents

Publication Publication Date Title
WO2019090907A1 (zh) 一种像素驱动电路及有机发光二极管显示装置
US11881164B2 (en) Pixel circuit and driving method thereof, and display panel
JP6882591B2 (ja) Ａｍｏｌｅｄピクセル駆動回路及びピクセル駆動方法
CN105702206B (zh) 一种像素矩阵的外围补偿系统及其方法、显示系统
CN103198794B (zh) 像素电路及其驱动方法、有机发光显示面板及显示装置
US11127342B2 (en) Pixel circuit for driving light emitting diode to emit light and method of controlling the pixel circuit
US20200211464A1 (en) Pixel circuit and driving method thereof, and display panel
CN110176213A (zh) 像素电路及其驱动方法、显示面板
US20170178569A1 (en) Pixel circuit and driving method thereof, array substrate, display device
WO2016119304A1 (zh) Amoled像素驱动电路及像素驱动方法
CN112233621B (zh) 一种像素驱动电路、显示面板及电子设备
KR20190067877A (ko) Amoled 픽셀 구동 회로 및 구동 방법
WO2019095494A1 (zh) 一种像素驱动电路及液晶显示装置
CN106097964A (zh) 像素电路、显示面板、显示设备及驱动方法
WO2016145693A1 (zh) Amoled像素驱动电路及像素驱动方法
WO2016127639A1 (zh) 像素电路的驱动方法及其驱动装置
WO2016011711A1 (zh) 像素电路、像素电路的驱动方法和显示装置
WO2016155053A1 (zh) Amoled像素驱动电路及像素驱动方法
WO2016123855A1 (zh) Amoled像素驱动电路及像素驱动方法
JP2020514821A (ja) ピクセル駆動回路及びｏｌｅｄディスプレイ装置
WO2016119305A1 (zh) Amoled像素驱动电路及像素驱动方法
US12499836B2 (en) Electroluminescent display apparatus
CN104318899A (zh) 像素单元驱动电路和方法、像素单元和显示装置
WO2017156828A1 (zh) Amoled像素驱动电路及像素驱动方法
CN101192373A (zh) 有机发光显示器及其具有电压补偿技术的有机发光像素

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 17931100

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 17931100

Country of ref document: EP

Kind code of ref document: A1