WO2016008191A1 - 具有自我补偿功能的栅极驱动电路 - Google Patents

具有自我补偿功能的栅极驱动电路 Download PDF

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Publication number
WO2016008191A1
WO2016008191A1 PCT/CN2014/084342 CN2014084342W WO2016008191A1 WO 2016008191 A1 WO2016008191 A1 WO 2016008191A1 CN 2014084342 W CN2014084342 W CN 2014084342W WO 2016008191 A1 WO2016008191 A1 WO 2016008191A1
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Prior art keywords
electrically connected
gate
thin film
film transistor
pull
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PCT/CN2014/084342
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English (en)
French (fr)
Inventor
戴超
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深圳市华星光电技术有限公司
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Priority to KR1020177003691A priority Critical patent/KR101957067B1/ko
Priority to GB1700519.0A priority patent/GB2542991B/en
Priority to JP2017502220A priority patent/JP6329691B2/ja
Priority to US14/398,733 priority patent/US9589520B2/en
Publication of WO2016008191A1 publication Critical patent/WO2016008191A1/zh

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    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20Control 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
    • G09G3/34Control 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
    • G09G3/36Control 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
    • G09G3/3611Control of matrices with row and column drivers
    • G09G3/3648Control of matrices with row and column drivers using an active matrix
    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/136Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit
    • G02F1/1362Active matrix addressed cells
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20Control 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
    • G09G3/34Control 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
    • G09G3/36Control 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
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20Control 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
    • G09G3/34Control 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
    • G09G3/36Control 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
    • G09G3/3611Control of matrices with row and column drivers
    • G09G3/3674Details of drivers for scan electrodes
    • G09G3/3677Details of drivers for scan electrodes suitable for active matrices only
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11CSTATIC STORES
    • G11C19/00Digital stores in which the information is moved stepwise, e.g. shift registers
    • G11C19/18Digital stores in which the information is moved stepwise, e.g. shift registers using capacitors as main elements of the stages
    • G11C19/182Digital stores in which the information is moved stepwise, e.g. shift registers using capacitors as main elements of the stages in combination with semiconductor elements, e.g. bipolar transistors, diodes
    • G11C19/184Digital stores in which the information is moved stepwise, e.g. shift registers using capacitors as main elements of the stages in combination with semiconductor elements, e.g. bipolar transistors, diodes with field-effect transistors, e.g. MOS-FET
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11CSTATIC STORES
    • G11C19/00Digital stores in which the information is moved stepwise, e.g. shift registers
    • G11C19/28Digital stores in which the information is moved stepwise, e.g. shift registers using semiconductor elements
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2230/00Details of flat display driving waveforms
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2300/00Aspects of the constitution of display devices
    • G09G2300/04Structural and physical details of display devices
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00Command of the display device
    • G09G2310/02Addressing, scanning or driving the display screen or processing steps related thereto
    • G09G2310/0264Details of driving circuits
    • G09G2310/0286Details of a shift registers arranged for use in a driving circuit
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00Command of the display device
    • G09G2310/08Details of timing specific for flat panels, other than clock recovery
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00Control of display operating conditions
    • G09G2320/02Improving the quality of display appearance
    • G09G2320/0209Crosstalk reduction, i.e. to reduce direct or indirect influences of signals directed to a certain pixel of the displayed image on other pixels of said image, inclusive of influences affecting pixels in different frames or fields or sub-images which constitute a same image, e.g. left and right images of a stereoscopic display
    • G09G2320/0214Crosstalk reduction, i.e. to reduce direct or indirect influences of signals directed to a certain pixel of the displayed image on other pixels of said image, inclusive of influences affecting pixels in different frames or fields or sub-images which constitute a same image, e.g. left and right images of a stereoscopic display with crosstalk due to leakage current of pixel switch in active matrix panels
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00Control of display operating conditions
    • G09G2320/04Maintaining the quality of display appearance
    • G09G2320/043Preventing or counteracting the effects of ageing
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2330/00Aspects of power supply; Aspects of display protection and defect management
    • G09G2330/02Details of power systems and of start or stop of display operation

Definitions

  • the present invention relates to the field of liquid crystal technology, and in particular, to a gate driving circuit with self-compensation function. Background technique
  • the GOA Gate Driver on Array
  • TFT Thin Film Transistor
  • the functions of the GOA circuit mainly include: charging the capacitor in the shift register unit by using a high level signal outputted by the gate line of the previous row, so that the gate line of the current line outputs a high level signal, and then using the high output of the next line of the gate line output.
  • the flat signal is reset.
  • FIG. 1 is a schematic diagram of a gate drive circuit structure that is currently used.
  • the method includes: cascading a plurality of GOA units, and controlling, according to the Nth stage GOA unit, charging the Nth horizontal scanning line G(N) of the display area, where the Nth stage GOA unit includes a pull-up control module ⁇ and a pull-up module 2 ′
  • the pull-up module 2', the first pull-down module 4', the bootstrap capacitor module 5', and the pull-down maintaining circuit 6' are respectively connected to the N-th gate signal point Q(N) and the N-th horizontal scanning line G (N) electrical connection, the pull-up control module ⁇ and the downlink module 3 ′ are respectively electrically connected to the Nth-level gate signal point Q(N), and the pull-down maintaining module 6 ′ inputs a DC low voltage VSS .
  • the pull-up control module ⁇ includes a first thin film transistor ⁇ whose gate input is a downlink signal ST(N-1) from the N-1th GOA unit, and the drain is electrically connected to the N-1th horizontal scan. a line G(N1), the source is electrically connected to the Nth-level gate signal point Q(N); the pull-up module 2' includes a second thin film transistor T2', and a gate thereof is electrically connected to the second stage a gate signal point Q(N;), a drain input first high frequency clock signal CK or a second high frequency clock signal XCK, and a source electrically connected to the Nth horizontal scanning line G(N);
  • the module 3 includes a third thin film transistor T3 having a gate electrically connected to the second gate signal point Q(N;), and a drain inputting the first high frequency clock signal CK or the second high frequency clock signal XCK.
  • the source outputs an Nth stage downlink signal ST(N);
  • the first pulldown module 4' includes a fourth thin film transistor T4' whose gate is electrically connected to the N+1th horizontal scanning line G(N+1), and the drain is electrically connected to the Nth horizontal scanning line G(N), the source Input DC low voltage VSS;
  • fifth thin film transistor T5' whose gate is electrically connected to the N+1th horizontal scanning line G(N+1), and the drain is electrically connected to the Nth level gate signal point Q ( N), the source input DC low voltage VSS;
  • the bootstrap capacitor module 5 includes a bootstrap capacitor Cb, and the pull-down maintaining module 6 includes: a sixth thin film transistor T6' whose gate is electrically connected first The circuit point ⁇ ( ⁇ )', the drain is electrically connected to the third horizontal scanning line G(N), the source input DC low voltage VSS, and the seventh thin film transistor T7, whose gate is electrically connected to the first circuit point ⁇ ( ⁇ )', the drain is electrically connected to the
  • the source is electrically connected to the first circuit point ⁇ ( ⁇ )'; the eleventh thin film transistor ⁇ 1 ⁇ , the gate thereof inputs the second low frequency clock signal LC2, the drain input the first low frequency clock signal LC1, and the source is electrically connected a circuit point ⁇ ( ⁇ )'; a twelfth thin film transistor ⁇ 12', a gate inputting a second low frequency clock signal LC2, a drain inputting a second low frequency clock signal LC2, and a source electrically connected to the second circuit point ⁇ ( ⁇
  • the thirteenth thin film transistor ⁇ 13' has a gate inputting a first low frequency clock signal LC1, a drain inputting a second low frequency clock signal LC2, and a source electrically connected to the second circuit point ⁇ ( ⁇ );
  • the thin film transistor ⁇ 14, the gate thereof is electrically connected to the second gate signal point Q(N), the drain is electrically connected to the first circuit point P(N)', and the source input DC low voltage VSS;
  • the pull-down maintaining module 6' is in a long working state, that is, the first circuit point p ⁇ ; Ny and the second circuit point KN)' will be in a positive high state for a long time, so that
  • the most severe components in the circuit that are subjected to voltage stress (Stress) are thin film transistors T6, ⁇ 7, ⁇ 8, ⁇ 9.
  • the threshold voltage Vth of the thin film transistors ⁇ 6, ⁇ 7, ⁇ 8, ⁇ 9 gradually increases, and the on-state current gradually decreases, which results in the Nth horizontal scanning line G.
  • the (N) and N-th gate signal points Q(N) are not well maintained at a stable low potential, which is the most important factor affecting the reliability of the gate drive circuit.
  • the pull-down sustain module is essential It can usually be designed as a set of pull-down maintenance modules, or as two sets of alternate pull-down maintenance modules.
  • the main purpose of designing the two sets of pull-down maintenance modules is to reduce the thin film transistors T6', T7', T8', T9' controlled by the first circuit point ⁇ ( ⁇ )' and the second circuit point ⁇ ( ⁇ )' in the pull-down maintenance module.
  • Subject to voltage stress However, the actual measurement found that even if designed as two sets of pull-down sustaining modules, thin film transistors ⁇ 6, ⁇ 7, ⁇ 8, ⁇ 9, these four thin film transistors are still the most severe part of the entire gate drive circuit. That is to say, the threshold voltage (Vth) of the thin film transistor drifts the most.
  • FIG. 2a is a schematic diagram showing the relationship between the logarithm of the overall current logarithm of the thin film transistor and the voltage curve before and after the threshold voltage drift, wherein the solid line is the relationship between the current logarithm and the voltage without threshold voltage drift, and the dashed line is the current after the threshold voltage drift.
  • Logarithm versus voltage curve As can be seen from Fig. 2a, under the same gate-to-source voltage Vgs, the current logarithm of the threshold voltage drift (Ids) is greater than the logarithm of the current after the threshold voltage drift.
  • Figure 2b is a schematic diagram showing the relationship between the overall current and voltage curves of the thin film transistor before and after the threshold voltage drift.
  • the gate voltage Vgl where the threshold voltage drift does not occur is smaller than the gate voltage Vg2 after the threshold voltage drift, that is, after the threshold voltage drift, it is desirable to achieve the same drain-source current. Ids, which requires a larger gate voltage.
  • the forward drift of the threshold voltage Vth causes the on-state current Ion of the thin film transistor to gradually decrease.
  • the threshold voltage Vth increases, the on-state current Ion of the thin film transistor continues to decrease.
  • the stability of the potential of the Nth-level gate signal point Q(N) and the N-th horizontal scanning line G(N) cannot be well maintained, which may cause an abnormality in the liquid crystal display screen display.
  • the most easily failing component in the gate driving circuit is the thin film transistors T6', ⁇ 7', ⁇ 8', and ⁇ 9' of the pull-down sustaining module. Therefore, in order to improve the reliability of the gate driving circuit and the liquid crystal display panel, it is necessary to improve the reliability of the gate driving circuit and the liquid crystal display panel. solve this problem.
  • the design method is to increase the size of the four thin film transistors. However, increasing the size of the thin film transistor also increases the off-state leakage current of the thin film transistor, and the problem cannot be solved. Summary of the invention
  • the object of the present invention is to provide a gate driving circuit with self-compensation function, which improves the reliability of the gate driving circuit for a long time by the pull-down maintaining module with self-compensation function, and reduces the threshold voltage drift to operate the gate driving circuit. Impact.
  • the present invention provides a gate driving circuit having a self-compensation function, comprising: a plurality of cascaded GOA units, and controlling a horizontal scanning line G(N) of a display area according to a level GOA unit Charging
  • the Nth stage GOA unit includes: a pull-up control module, a pull-up a module, a downlink module, a first pull-down module, a bootstrap capacitor module, and a pull-down maintenance module; the pull-up module, the first pull-down module, the bootstrap capacitor module, and the pull-down sustain circuit respectively and the Nth-level gate signal
  • the point Q(N) is electrically connected to the Nth horizontal scanning line G(N), and the pull-up control module and the downlink module are electrically connected to the Nth-level gate signal point Q(N), respectively.
  • the pull-down maintenance module inputs a first DC low voltage VSS1 and a second DC low voltage VSS2;
  • the pull-down maintaining module includes: a first thin film transistor T1 whose gate is electrically connected to the first circuit point ⁇ , and the drain is electrically connected to the third horizontal scanning line G(N), and the source input is first straight a low voltage VSS1; a second thin film transistor T2 whose gate is electrically connected to the first circuit point ⁇ ( ⁇ ), the drain is electrically connected to the second gate signal point Q(N), and the source input is the first direct current The low voltage VSS1; the third thin film transistor T3, the gate of which is electrically connected to the DC signal source DC, the drain is electrically connected to the DC signal source DC, the source is electrically connected to the second circuit point S(N); the fourth thin film transistor T4 The gate is electrically connected to the second gate signal point Q(N), the drain is electrically connected to the second circuit point S(N), the source input is the first DC low voltage VSS1, and the fifth thin film transistor T5 is The gate is electrically connected to the N-1 stage down signal ST(N-1), the drain is electrically connected to
  • the pull-up control module includes a ninth thin film transistor T9 whose gate is input with a down signal ST(N-1) from the N-1th stage GOA unit, and the drain is electrically connected to the N-1th horizontal scan line.
  • G(N1) the source is electrically connected to the Nth gate signal point Q(N);
  • the pull-up module includes a tenth thin film transistor T10, and a gate thereof is electrically connected to the second gate signal point Q(N;), the drain input first high frequency clock signal CK or second high frequency clock signal XCK, the source is electrically connected to the Nth horizontal scanning line GN);
  • the down transmission module includes the eleventh film
  • the transistor T11 has a gate electrically connected to the second-order gate signal point Q(N;), a drain inputting the first high-frequency clock signal CK or a second high-frequency clock signal XCK, and a source output of the Nth stage.
  • the first pull-down module includes a twelfth thin film transistor T12, the gate of which is electrically connected to the ⁇ +2 horizontal scanning line G(N+2), and the drain is electrically connected to the Nth Level horizontal scanning line G(N), source input first DC low voltage VSS1; thirteenth thin film transistor T13, its gate is electrically connected to the ⁇ +2 horizontal scanning line G(N+2), drain Electrically connected to The first N-level gate signal point Q (N), a first source input DC voltage VSS1 is low; the bootstrap capacitor module comprises a bootstrap capacitor Cb.
  • the gate of the fifth thin film transistor T5 is electrically connected to the circuit enable signal STV; the gate and the drain of the ninth thin film transistor T9 are electrically connected to the circuit enable signal. STV.
  • the gate of the sixth thin film transistor T6 is electrically connected to the circuit enable signal STV; the gate of the twelfth thin film transistor T12 is electrically connected to the second-level horizontal scan line. G(2); The gate of the thirteenth thin film transistor T13 is electrically connected to the second-level horizontal scanning line G(2).
  • the pull-down maintaining module further includes: a second capacitor Cst2, the upper plate is electrically connected to the first circuit point P(N;), and the lower plate is input to the first DC low voltage VSS1.
  • the pull-down maintaining module further includes: a fourteenth thin film transistor ⁇ 14, the gate of which is electrically connected
  • N+1 horizontal scanning line G(N+1), the drain is electrically connected to the second circuit point S(N), and the source input is the first DC low voltage VSS1.
  • the pull-down maintaining module further includes: a second capacitor Cst2, the upper plate is electrically connected to the first circuit point P(N), the lower plate is input to the first DC low voltage VSS1, and the fourteenth thin film transistor T14 is gated
  • the first N+1 horizontal scanning line G(N+1) is electrically connected, the drain is electrically connected to the second circuit point S(N), and the source is input to the first DC low voltage VSS1.
  • the first high frequency clock signal CK and the second high frequency clock signal XCK are two high frequency clock signal sources whose phases are completely opposite.
  • the gate of the twelfth thin film transistor T12 and the gate of the thirteenth thin film transistor T13 in the first pull-down module are electrically connected to the N+2 horizontal scanning line G(N+2), mainly for implementing the first
  • the N-level gate signal point Q(N) potential is in three stages.
  • the first stage is to rise to a high level for a period of time, and the second stage is raised to a high level and maintained for a period of time on the basis of the first stage.
  • the third phase falls to the high level that is substantially equal to the first phase on the basis of the second phase, and then uses the third phase of the three phases to perform self-compensation of the threshold voltage.
  • the Nth gate signal point (Q(N)) potential has three phases, wherein the third phase is mainly affected by the sixth thin film transistor T6.
  • the gate of the sixth thin film transistor T6 may be electrically connected to the N+1th down signal ST(N+1).
  • the second DC low voltage VSS2 is a negative voltage source, and the potential of the second DC low voltage VSS2 is lower than the first DC low voltage VSS1.
  • the present invention provides a gate driving circuit having a self-compensation function, which utilizes a bootstrap action of a capacitor to control a first circuit point P(N) of a pull-down maintaining module, and is designed to detect a threshold voltage of a thin film transistor. Function, and storing the threshold voltage at the first circuit point P(N), thereby implementing the control voltage of the first circuit point P(N) as the threshold voltage of the thin film transistor drifts Chemical.
  • the invention improves the reliability of the long-term operation of the gate driving circuit by designing the pull-down maintaining module with self-compensation function, reduces the influence of the threshold voltage drift on the operation of the gate driving circuit, and can also be designed directly by a group of DC signal sources DC
  • the controlled pull-down maintenance module not only saves space in the layout of the circuit layout, but also reduces the overall power consumption of the circuit.
  • FIG. 1 is a schematic diagram of a gate drive circuit structure currently used
  • 2a is a schematic diagram showing changes in the relationship between the logarithm of the overall current of the thin film transistor and the voltage curve before and after the threshold voltage drift;
  • Figure 2b is a schematic diagram showing the relationship between the overall current and voltage curves of the thin film transistor before and after the threshold voltage drift;
  • FIG. 3 is a schematic diagram of a single-stage architecture of a gate driving circuit with self-compensation function according to the present invention
  • FIG. 4 is a schematic diagram of a first-level connection relationship of a single-stage architecture of a gate driving circuit with self-compensation function according to the present invention
  • FIG. 5 is a schematic diagram showing the connection relationship of the last stage of the single-stage architecture of the gate driving circuit with self-compensation function according to the present invention.
  • FIG. 6 is a circuit diagram of a first embodiment of the pull-down maintaining module employed in FIG. 3;
  • Figure 7a is a timing diagram of the gate driving circuit shown in Figure 3 before the threshold voltage drift
  • Figure 7b is a timing diagram of the gate driving circuit shown in Figure 3 after the threshold voltage drift
  • Figure 8 is a circuit diagram of a second embodiment of the pull-down maintaining module employed in Figure 3;
  • FIG. 9 is a circuit diagram of a third embodiment of the pull-down maintaining module employed in FIG. 3;
  • Figure 10 is a circuit diagram of a fourth embodiment of the pull-down maintaining module employed in Figure 3. detailed description
  • FIG. 3 is a schematic diagram of a single-stage architecture of a gate driving circuit with self-compensation function according to the present invention.
  • the method includes: cascading multiple GOA units, controlling the display area according to the Nth level GOA unit
  • the Nth horizontal scanning line G(N) is charged, and the Nth stage GOA unit comprises: a pull-up control module 1, a pull-up module 2, a downlink module 3, a first pull-down module 4, a bootstrap capacitor module 5, and Pull-down maintaining module 6; the pull-up module 2, the first pull-down module 4, the bootstrap capacitor module 5, and the pull-down maintaining circuit 6 and the Nth-level gate signal point Q(N) and the N-th horizontal scanning line, respectively
  • the G (N) is electrically connected, and the pull-up control module 1 and the downlink module 3 are electrically connected to the Nth-level gate signal point Q(N), and the pull-down maintaining module 6 inputs the first DC low. Voltage VSS1 and second DC low voltage VSS2.
  • the pull-down maintaining module 6 includes: a first thin film transistor T1 whose gate is electrically connected to the first circuit point ⁇ , and the drain is electrically connected to the third horizontal scanning line G(N), and the source input is first.
  • the third thin film transistor T3 adopts a diode connection, the gate is electrically connected to the DC signal source DC, the drain is electrically connected to the DC signal source DC, and the source is electrically connected to the second circuit point S ( N);
  • the fourth thin film transistor T4 whose gate is electrically connected to the second gate signal point Q(N), the drain is electrically connected to the second circuit point S(N), and the source input first DC low voltage VSS1;
  • the fifth thin film transistor T5 has a gate electrically connected to the N-1th
  • the pull-up control module 1 includes a ninth thin film transistor T9 whose gate is input with a down signal ST(N-1) from the N-1th GOA unit, and the drain is electrically connected to the N-1th horizontal scan.
  • a line G(N1) the source is electrically connected to the Nth gate signal point Q(N);
  • the pull-up module 2 includes a tenth thin film transistor T10, and a gate thereof is electrically connected to the second gate a signal point Q(N;), a drain input first high frequency clock signal CK or a second high frequency clock signal XCK, the source is electrically connected to the Nth horizontal scan line GN);
  • the down pass module 3 includes
  • the eleven thin film transistor T11 has a gate electrically connected to the second gate signal point Q(N;), and a drain input first high frequency clock signal CK or a a second high frequency clock signal XCK, a source output Nth stage down signal ST(N);
  • the first pull down module 4 includes a twelfth thin film
  • the drain is electrically connected to the Nth gate signal point Q(N), and the source input is the first DC low voltage VSS1; the first pulldown
  • the gate of the twelfth thin film transistor T12 and the gate of the thirteenth thin film transistor T13 in the module 4 are electrically connected to the N+2 horizontal scanning line G(N+2), mainly for implementing the Nth gate.
  • the signal point Q(N) potential is in three stages. The first stage is to rise to a high level and maintain for a period of time. The second stage rises to a high level and maintains a period of time on the basis of the first stage.
  • the third stage is On the basis of the second phase, it drops to a high potential that is substantially equal to the first phase, and then uses the third phase of the three phases to perform self-compensation of the threshold voltage;
  • the bootstrap capacitor module 5 includes a bootstrap capacitor Cb.
  • the number of stages between the multi-level horizontal scanning lines is cyclic, that is, when N in the Nth horizontal scanning line G(N) is the last level Last, the N+2 horizontal scanning line G (N+ 2) represents the second level horizontal scanning line G(2); when N in the Nth horizontal scanning line G(N) is the penultimate level Last-1, the N+2th horizontal scanning line G(N+ 2) represents the first level horizontal scanning line G(l), and so on.
  • FIG. 4 is a schematic diagram showing the first-level connection relationship of the single-stage architecture of the gate driving circuit with self-compensation function, that is, the connection relationship of the gate driving circuit when N is 1.
  • the gate of the fifth thin film transistor T5 is electrically connected to the circuit enable signal STV; the gate and the drain of the ninth thin film transistor T9 are electrically connected to the circuit enable signal STV.
  • FIG. 5 is a schematic diagram showing the connection relationship of the last stage of the single-stage architecture of the gate driving circuit with self-compensation function, that is, the connection relationship of the gate driving circuit when N is the last stage Last.
  • the gate of the sixth thin film transistor T6 is electrically connected to the circuit enable signal STV; the gate of the twelfth thin film transistor T12 is electrically connected to the second horizontal scan line G(2); the thirteenth thin film transistor T13 The gate is electrically connected to the second level horizontal scanning line G(2).
  • FIG. 6 is a circuit diagram of the first embodiment of the pull-down maintenance module employed in FIG. 3, wherein the control signal source uses only the DC signal source DC.
  • the first thin film transistor T1 has a gate electrically connected to the first circuit point ⁇ , the drain is electrically connected to the third horizontal scanning line G(N), and the source is input to the first DC low voltage VSS1;
  • the second thin film transistor T2 has a gate electrically connected to the first circuit point ⁇ ( ⁇ ), a drain electrically connected to the ⁇ stage gate signal point Q(N), and a source input first DC low voltage VSS1;
  • the three thin film transistor T3 adopts a diode connection method, the gate is electrically connected to the DC signal source DC, the drain is electrically connected to the DC signal source DC, and the source is electrically connected to the second circuit point S(N);
  • the fourth film The transistor T4 has a gate electrically connected to the second-order gate signal point Q(N), a drain electrically connected to the second circuit point S(N),
  • the eighth thin film transistor T8 has a gate electrically connected to the first circuit point ⁇ ( ⁇ :), a drain electrically connected to the ⁇ th stage down signal ST(N:), and a source input second DC low voltage VSS2
  • the eighth thin film transistor T8 is mainly responsible for pulling down the Nth stage down signal ST(N) to a negative potential second DC low voltage VSS2.
  • the first capacitor Cstl, the upper plate is electrically connected to the second circuit point S(N), and the lower plate is electrically connected to the first circuit point P(N).
  • the gate of the third thin film transistor T3 is electrically connected to the DC signal source DC, and the DC signal source DC can reduce the overall power consumption of the circuit, but also increases the voltage stress of the pull-down maintaining module 6.
  • FIG. 7a is a timing diagram of the gate driving circuit shown in FIG. 3 before the threshold voltage drift
  • FIG. 7b is a timing chart of the gate driving circuit shown in FIG. 3 after the threshold voltage drift
  • the STV signal is a circuit enable signal
  • the first high frequency clock signal CK and the second high frequency clock signal XCK are a set of high frequency clock signal sources having completely opposite phases
  • the DC is a high potential DC.
  • the signal source, G(N-1) is the N-1th horizontal scanning line, that is, the scanning output signal of the previous stage
  • ST(N-1) is the N-1 level downlink signal, that is, the lower level of the previous stage.
  • the signal is transmitted
  • Q(Nl) is the N-1th gate signal point, that is, the gate signal point of the previous stage
  • Q(N) is the Nth gate signal point, that is, the gate signal point of the current stage.
  • the potential of the Nth-level gate signal point Q(N) is in three stages, and the change in the third stage of the three stages is mainly affected by the sixth thin film transistor T6.
  • the threshold voltage Vth is small, that is, when the gate driving circuit does not undergo long-term operation, the threshold voltage Vth does not drift, and the Nth-level gate signal point Q
  • the potential of the third stage of (N) is low, and the potential of the first circuit point P(N) corresponding thereto is also low. It can be seen from Fig.
  • the operation of the gate driving circuit shown in FIG. 3 is as follows: When the N+1th horizontal scanning line G N+l) is turned on, the sixth thin film transistor T6 is turned on, and the Nth stage gate is turned on.
  • the signal point Q(N) is the same as the potential of the first circuit point P(N), the second thin film transistor T2 is equivalent to the diode connection, and the first circuit point P(N) is at the Nth stage gate signal point Q.
  • the value of the threshold voltage of the first thin film transistor T1 and the second thin film transistor T2 may be stored by the sixth thin film transistor T6, and then, with the drift of the threshold voltage Vth, the Nth gate signal point
  • the potential rise of the third stage of Q(N), the potential value of the threshold voltage stored at the first circuit point PN) is also raised, and then the second circuit point S(N) is raised by the first capacitor Cstl to raise the first circuit. Point P(N) so that the change in threshold voltage can be compensated.
  • the potential of the Nth gate signal point Q(N) and the first circuit point P(N) also changes significantly, especially the first circuit point P (
  • the increase in the potential of N) can effectively reduce the influence of the threshold voltage drift on the on-state currents of the first thin film transistor T1 and the second thin film transistor T2, thereby ensuring the Nth horizontal scanning line G(N) and the Nth stage gate signal.
  • Point Q(N) is still well maintained at a low potential after long-term operation.
  • the sixth thin film transistor T6 stores a higher threshold voltage value to the first circuit point P ( N), then, the potential of the first circuit point P(N) will become higher after the bootstrap rise, so that the negative effect caused by the increase of the threshold voltage Vth can be compensated, and the pull-down maintenance module can be self-compensated, Effectively improve the reliability of the pull-down maintenance module; and with this self-compensated pull-down maintenance module design, it is not necessary to design two modules that work alternately, and only one pull-down maintenance module controlled by the DC signal source can be designed. This reduces power consumption and saves layout space.
  • FIG. 8 is a circuit diagram of a second embodiment of the pull-down maintaining module employed in FIG. 8 is a second capacitor Cst2 added to the base of FIG. 6, the upper plate is electrically connected to the first circuit point P (N;), and the lower plate is input with the first DC low voltage VSS1 and the second capacitor Cst2.
  • the main function is to store the threshold voltage. Since the first thin film transistor T1 and the second thin film transistor T2 have a certain parasitic capacitance, they can function as the second capacitor Cst2, and therefore, the second capacitor Cst2 can be removed in the actual circuit design.
  • FIG. 9 is a circuit diagram of a third embodiment of the pull-down maintaining module employed in FIG.
  • FIG. 9 is a diagram of adding a fourteenth thin film transistor T14 on the basis of FIG. 6, the gate of which is electrically connected to the N+1th horizontal scanning line G(N+1), and the drain is electrically connected to the second circuit point S ( N), the source input first DC low voltage VSS1; the main purpose of the fourteenth thin film transistor T14 is to make up for the second stage of the Nth stage gate signal point Q(N) Point S(N) action The potential pulldown is not low enough during the period.
  • FIG. 10 is a circuit diagram of a fourth embodiment of the pull-down maintaining module employed in FIG. Figure 10 is added on the basis of Figure 6:
  • the second capacitor Cst2 the upper plate is electrically connected to the first circuit point P (N), the lower plate is input to the first DC low voltage VSS1;
  • the fourteenth thin film transistor T14 The gate is electrically connected to the N+1th horizontal scanning line G(N+1), the drain is electrically connected to the second circuit point S(N), and the source is input to the first DC low voltage VSS1.
  • the pull-down maintaining module 6 in the single-stage architecture of the gate driving circuit shown in FIG. 3 can be replaced with any one of the pull-down sustaining module designs of FIG. 6, FIG. 8, FIG. 9, and FIG. 10, and the replaced gate driving circuit
  • the timing chart is the same as that of FIG. 7a and FIG. 7b, and its working process is the same as that of the gate driving circuit shown in FIG. 3, and therefore will not be described again.
  • the present invention provides a gate drive circuit with self-compensation function.
  • the bootstrap action of the capacitor is utilized. Controlling the first circuit point P(N) of the pull-down maintaining module, designing a function capable of detecting the threshold voltage of the thin film transistor, and storing the threshold voltage at the first circuit point P(N), thereby implementing the first circuit point P(N)
  • the control voltage varies as the threshold voltage of the thin film transistor drifts.
  • the invention improves the reliability of the long-term operation of the gate driving circuit by designing the pull-down maintaining module with self-compensation function, reduces the influence of the threshold voltage drift on the operation of the gate driving circuit, and can also be designed directly by a group of DC signal sources DC
  • the controlled pull-down maintenance module not only saves space in the layout of the circuit layout, but also reduces the overall power consumption of the circuit.

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Abstract

一种具有自我补偿功能的栅极驱动电路,包括:级联的多个GOA单元,按照第N级GOA单元控制对显示区域的第N级水平扫描线G(N)充电,该第N级GOA单元包括:上拉控制模块(1)、上拉模块(2)、下传模块(3)、第一下拉模块(4)、自举电容模块(5)及下拉维持模块(6);所述上拉模块(2)、第一下拉模块(4)、自举电容模块(5)、下拉维持模块(6)分别与第N级栅极信号点Q(N)和该第N级水平扫描线G(N)电性连接,所述上拉控制模块(1)与下传模块(3)分别与该第N级栅极信号点Q(N)电性连接,所述下拉维持模块(6)输入第一直流低电压VSS1及第二直流低电压VSS2。所述驱动电路通过具有自我补偿功能的下拉维持模块(6)来提高栅极驱动电路长期操作的可靠性;还可以设计成直接由一组直流信号源DC控制的下拉维持模块(6),既可以节省电路版图设计空间,又可以降低电路的整体功耗。

Description

具有自我补偿功能的栅极驱动电路 技术领域
本发明涉及液晶技术领域, 尤其涉及一种具有自我补偿功能的栅极驱 动电路。 背景技术
GOA (Gate Driver on Array, 阵列基板行驱动) 技术是将作为栅极开关 电路的 TFT (Thin Film Transistor, 薄膜场效应晶体管) 集成于阵列基板上, 从而省掉原先设置在阵列基板外的栅极驱动集成电路部分, 从材料成本和 工艺步骤两个方面来降低产品的成本。 GOA 技术是目前 TFT-LCD (Thin Film Transistor-Liquid Crystal Display, 薄膜场效应晶体管液晶显示器) 技术 领域常用的一种栅极驱动电路技术, 其制作工艺简单, 具有良好的应用前 景。 GOA电路的功能主要包括: 利用上一行栅线输出的高电平信号对移位 寄存器单元中的电容充电, 以使本行栅线输出高电平信号, 再利用下一行 栅线输出的高电平信号实现复位。
请参阅图 1, 图 1为目前常采用的栅极驱动电路架构示意图。 包括: 级 联的多个 GOA单元,按照第 N级 GOA单元控制对显示区域第 N级水平扫 描线 G(N)充电, 该第 N级 GOA单元包括上拉控制模块 Γ、 上拉模块 2'、 下传模块 3 '、 第一下拉模块 4' (Key pull-down part) , 自举电容模块 5'、 及 下拉維持模块 6' (Pull-down holding part)。 所述上拉模块 2'、 第一下拉模 块 4'、 自举电容模块 5'、 下拉維持电路 6'分别与第 N级栅极信号点 Q(N) 和该第 N级水平扫描线 G(N)电性连接,所述上拉控制模块 Γ与下传模块 3' 分别与该第 N级栅极信号点 Q(N)电性连接, 所述下拉維持模块 6'输入直流 低电压 VSS。
所述上拉控制模块 Γ包括第一薄膜晶体管 ΤΓ, 其栅极输入来自第 N-1 级 GOA 单元的下传信号 ST(N-1), 漏极电性连接于第 N-1 级水平扫描线 G(N-l), 源极电性连接于该第 N级栅极信号点 Q(N); 所述上拉模块 2'包括 第二薄膜晶体管 T2', 其栅极电性连接该第 Ν级栅极信号点 Q(N;), 漏极输 入第一高频时钟信号 CK或第二高频时钟信号 XCK, 源极电性连接于第 N 级水平扫描线 G(N) ; 所述下传模块 3,包括第三薄膜晶体管 T3,, 其栅极电 性连接该第 Ν级栅极信号点 Q(N;), 漏极输入第一高频时钟信号 CK或第二 高频时钟信号 XCK, 源极输出第 N级下传信号 ST(N); 所述第一下拉模块 4'包括第四薄膜晶体管 T4',其栅极电性连接第 N+1级水平扫描线 G(N+1), 漏极电性连接于第 N级水平扫描线 G(N), 源极输入直流低电压 VSS ; 第五 薄膜晶体管 T5', 其栅极电性连接第 N+1级水平扫描线 G(N+1), 漏极电性 连接于该第 N级栅极信号点 Q(N), 源极输入直流低电压 VSS ; 所述自举电 容模块 5,包括自举电容 Cb,; 所述下拉維持模块 6,包括: 第六薄膜晶体管 T6', 其栅极电性连接第一电路点 Ρ(Ν)', 漏极电性连接第 Ν级水平扫描线 G(N), 源极输入直流低电压 VSS ; 第七薄膜晶体管 T7,, 其栅极电性连接第 一电路点 Ρ(Ν)', 漏极电性连接该第 Ν级栅极信号点(¾Ν), 源极输入直流 低电压 VSS ; 第八薄膜晶体管 Τ8', 其栅极电性连接第二电路点 Κ(Ν)', 漏 极电性连接第 Ν级水平扫描线 G(N), 源极输入直流低电压 VSS ; 第九薄膜 晶体管 T9', 其栅极电性连接第二电路点 Κ(Ν)', 漏极电性连接该第 Ν级栅 极信号点 Q(N), 源极输入直流低电压 VSS ; 第十薄膜晶体管 T10', 其栅极 输入第一低频时钟信号 LC1, 漏极输入第一低频时钟信号 LC1, 源极电性 连接第一电路点 Ρ(Ν)' ; 第十一薄膜晶体管 Τ1Γ, 其栅极输入第二低频时钟 信号 LC2, 漏极输入第一低频时钟信号 LC1, 源极电性连接第一电路点 Ρ(Ν)' ; 第十二薄膜晶体管 Τ12', 其栅极输入第二低频时钟信号 LC2, 漏极 输入第二低频时钟信号 LC2, 源极电性连接第二电路点 Κ(Ν)' ; 第十三薄膜 晶体管 Τ13', 其栅极输入第一低频时钟信号 LC1, 漏极输入第二低频时钟 信号 LC2, 源极电性连接第二电路点 Κ(Ν),; 第十四薄膜晶体管 Τ14,, 其 栅极电性连接该第 Ν级栅极信号点 Q(N), 漏极电性连接第一电路点 P(N)', 源极输入直流低电压 VSS ; 第十五薄膜晶体管 T15', 其栅极电性连接该第 Ν级栅极信号点 Q(N), 漏极电性连接第二电路点 Κ(Ν)', 源极输入直流低 电压 VSS ; 其中, 第六薄膜晶体管 Τ6,与第八薄膜晶体管 Τ8,负责非作用期 间維持第 Ν级水平扫描线 G(N)的低电位, 第七薄膜晶体管 T7,与第九薄膜 晶体管 T9'负责非作用期间維持第 Ν级栅极信号点 Q(N)的低电位。
从整个电路架构上来看, 下拉維持模块 6'处于较长的工作状态, 也就 是第一电路点 p<;Ny与第二电路点 K N)'会长时间处于一个正向的高电位状 态, 这样电路中受到电压应力作用 (Stress) 最严重的几个元件就是薄膜晶 体管 T6,、 Τ7,、 Τ8,、 Τ9,。 随着栅极驱动电路工作时间的增加, 薄膜晶体 管 Τ6,、 Τ7,、 Τ8,、 Τ9,的阈值电压 Vth会逐渐增加, 开态电流会逐渐降低, 这就会导致第 N级水平扫描线 G(N)和第 N级栅极信号点 Q(N)无法很好地 維持在一个稳定的低电位状态, 这也是影响栅极驱动电路可靠性最重要的 因素。
对于非晶硅薄膜晶体管栅极驱动电路而言, 下拉維持模块是必不可少 的, 通常可以设计为一组下拉維持模块, 或者两组交替作用的下拉維持模 块。 设计成两组下拉維持模块主要目的就是为了减轻下拉維持模块中第一 电路点 Ρ(Ν)'与第二电路点 Κ(Ν)'控制的薄膜晶体管 T6'、 T7'、 T8'、 T9'受 到的电压应力作用。 但是实际量测发现, 即使设计成两组下拉維持模块, 薄膜晶体管 Τ6,、 Τ7,、 Τ8,、 Τ9,这四颗薄膜晶体管依然是整个栅极驱动电 路电路中受到电压应力最严重的部分, 也就是说薄膜晶体管的阈值电压 (Vth) 漂移最大。
请参阅图 2a, 为阈值电压漂移前后薄膜晶体管整体电流对数与电压曲 线关系变化示意图, 其中, 实线是未发生阈值电压漂移的电流对数与电压 关系曲线, 虚线是阈值电压漂移后的电流对数与电压关系曲线。 由图 2a可 知, 在同一栅源极电压 Vgs 下, 未发生阈值电压漂移的电流对数 Log(Ids) 大于阈值电压漂移后的电流对数。 请参阅图 2b, 为阈值电压漂移前后薄膜 晶体管整体电流与电压曲线关系变化示意图。 由图 2b可知, 在同一漏源极 电流 Ids下, 未发生阈值电压漂移的栅极电压 Vgl 小于阈值电压漂移后的 栅极电压 Vg2, 即阈值电压漂移后, 想要达到同等的漏源极电流 Ids, 需要 更大的栅极电压。
由图 2a与图 2b可以看出, 阈值电压 Vth往正向漂移会导致薄膜晶体 管的开态电流 Ion逐渐降低, 随着阈值电压 Vth的增加, 薄膜晶体管的开态 电流 Ion会持续降低, 那么, 对于电路而言, 就无法很好地維持第 N级栅 极信号点 Q(N)与第 N级水平扫描线 G(N)电位的稳定, 这样就会导致液晶 显示器画面显示的异常。
如上所述, 栅极驱动电路中最容易失效的元件就是下拉維持模块的薄 膜晶体管 T6'、 Τ7'、 Τ8'、 Τ9', 因此, 为了提高栅极驱动电路和液晶显示 面板的可靠性必须要解决这个问题。 通常设计上的做法是增加这四颗薄膜 晶体管的尺寸, 但是, 增加薄膜晶体管尺寸的同时也会增加薄膜晶体管工 作的关态漏电流, 无法从本^上解决问题。 发明内容
本发明的目的在于提供一种具有自我补偿功能的栅极驱动电路, 通过 具有自我补偿功能的下拉維持模块来提高栅极驱动电路长期搡作的可靠 性, 降低阈值电压漂移对栅极驱动电路运作的影响。
为实现上述目的, 本发明提供一种具有自我补偿功能的栅极驱动电路, 包括: 级联的多个 GOA单元, 按照第 Ν级 GOA单元控制对显示区域第 Ν 级水平扫描线 G(N)充电, 该第 N级 GOA单元包括: 上拉控制模块、 上拉 模块、 下传模块、 第一下拉模块、 自举电容模块、 及下拉維持模块; 所述 上拉模块、 第一下拉模块、 自举电容模块、 下拉維持电路分别与第 N级栅 极信号点 Q(N)和该第 N级水平扫描线 G(N)电性连接, 所述上拉控制模块 与下传模块分别与该第 N级栅极信号点 Q(N)电性连接, 所述下拉維持模块 输入第一直流低电压 VSS1及第二直流低电压 VSS2 ;
所述下拉維持模块包括: 第一薄膜晶体管 Tl, 其栅极电性连接第一电 路点 Ρ(Ν), 漏极电性连接第 Ν级水平扫描线 G(N), 源极输入第一直流低电 压 VSS1 ; 第二薄膜晶体管 T2, 其栅极电性连接第一电路点 Ρ(Ν), 漏极电 性连接第 Ν级栅极信号点 Q(N), 源极输入第一直流低电压 VSS1 ; 第三薄 膜晶体管 T3, 其栅极电性连接直流信号源 DC, 漏极电性连接直流信号源 DC, 源极电性连接第二电路点 S(N); 第四薄膜晶体管 T4, 其栅极电性连 接第 Ν级栅极信号点 Q(N), 漏极电性连接第二电路点 S(N), 源极输入第一 直流低电压 VSS1 ; 第五薄膜晶体管 T5, 其栅极电性连接第 N-1 级下传信 号 ST(N-1), 漏极电性连接第一电路点 P(N), 源极输入第一直流低电压 VSS1 ; 第六薄膜晶体管 T6, 其栅极电性连接第 N+1级水平扫描线 G(N+1), 漏极电性连接第一电路点 P(N), 源极电性连接第 N级栅极信号点 Q(N) ; 第 七薄膜晶体管 Τ7, 其栅极电性连接第 Ν级下传信号 ST(N), 漏极电性连接 第一电路点 P(N), 源极输入第一直流低电压 VSS1 ; 第八薄膜晶体管 T8, 其栅极电性连接第一电路点 Ρ(Ν), 漏极电性连接第 Ν级下传信号 ST(N), 源极输入第二直流低电压 VSS2 ; 第一电容 Cstl, 其上极板电性连接第二电 路点 S N;), 下极板电性连接第一电路点 P N;)。
所述上拉控制模块包括第九薄膜晶体管 T9, 其栅极输入来自第 N-1级 GOA 单元的下传信号 ST(N-1), 漏极电性连接于第 N-1 级水平扫描线 G(N-l), 源极电性连接于该第 N级栅极信号点 Q(N) ; 所述上拉模块包括第 十薄膜晶体管 T10, 其栅极电性连接该第 Ν级栅极信号点 Q(N;), 漏极输入 第一高频时钟信号 CK或第二高频时钟信号 XCK, 源极电性连接于第 N级 水平扫描线 G N) ; 所述下传模块包括第十一薄膜晶体管 Tll, 其栅极电性 连接该第 Ν级栅极信号点 Q(N;), 漏极输入第一高频时钟信号 CK或第二高 频时钟信号 XCK, 源极输出第 N级下传信号 ST(N); 所述第一下拉模块包 括第十二薄膜晶体管 T12, 其栅极电性连接第 Ν+2级水平扫描线 G(N+2), 漏极电性连接于第 N级水平扫描线 G(N), 源极输入第一直流低电压 VSS1 ; 第十三薄膜晶体管 T13, 其栅极电性连接第 Ν+2级水平扫描线 G(N+2), 漏 极电性连接于该第 N级栅极信号点 Q(N), 源极输入第一直流低电压 VSS1 ; 所述自举电容模块包括自举电容 Cb。 所述栅极驱动电路的第一级连接关系中, 第五薄膜晶体管 T5的栅极电 性连接于电路启动信号 STV;第九薄膜晶体管 T9的栅极和漏极均电性连接 于电路启动信号 STV。
所述栅极驱动电路的最后一级连接关系中, 第六薄膜晶体管 T6 的栅 极电性连接于电路启动信号 STV; 第十二薄膜晶体管 T12的栅极电性连接 于第二级水平扫描线 G(2) ; 第十三薄膜晶体管 T13的栅极电性连接于第二 级水平扫描线 G(2)。
所述下拉維持模块还包括: 第二电容 Cst2, 其上极板电性连接第一电 路点 P(N;), 下极板输入第一直流低电压 VSS1。
所述下拉維持模块还包括: 第十四薄膜晶体管 Τ14, 其栅极电性连接第
N+1级水平扫描线 G(N+1), 漏极电性连接第二电路点 S(N), 源极输入第一 直流低电压 VSS1。
所述下拉維持模块还包括: 第二电容 Cst2, 其上极板电性连接第一电 路点 P(N), 下极板输入第一直流低电压 VSS1 ; 第十四薄膜晶体管 T14, 其 栅极电性连接第 N+1 级水平扫描线 G(N+1), 漏极电性连接第二电路点 S(N), 源极输入第一直流低电压 VSS1。
所述第一高频时钟信号 CK与第二高频时钟信号 XCK是两个相位完全 相反的高频时钟信号源。
所述第一下拉模块中第十二薄膜晶体管 T12 的栅极与第十三薄膜晶体 管 T13的栅极均电性连接第 N+2级水平扫描线 G(N+2),主要为了实现第 N 级栅极信号点 Q(N)电位呈三个阶段, 第一阶段是上升至一个高电位并維持 一段时间, 第二阶段在第一阶段的基础上又上升一个高电位并維持一段时 间, 第三阶段在第二阶段的基础上下降到与第一阶段基本持平的高电位, 然后利用三个阶段中的第三阶段进行阈值电压的自我补偿。
所述第 N级栅极信号点 (Q(N)) 电位呈三个阶段, 其中第三阶段的变 化主要受第六薄膜晶体管 T6的影响。
所述第六薄膜晶体管 T6 的栅极可以电性连接于第 N+1 级下传信号 ST(N+1)。
所述第二直流低电压 VSS2为负压源,该第二直流低电压 VSS2的电位 低于第一直流低电压 VSS1。
本发明的有益效果: 本发明提供一种具有自我补偿功能的栅极驱动电 路, 利用电容的自举作用来控制下拉維持模块的第一电路点 P(N), 设计能 够检测薄膜晶体管阈值电压的功能,并将阈值电压存贮在第一电路点 P(N), 进而实现第一电路点 P(N)的控制电压随着薄膜晶体管的阈值电压漂移而变 化。 本发明通过设计具有自我补偿功能的下拉維持模块来提高栅极驱动电 路长期搡作的可靠性, 降低阈值电压漂移对栅极驱动电路运作的影响; 还 可以设计成直接由一组直流信号源 DC控制的下拉維持模块,既可以节省电 路版图设计空间, 又可以降低电路的整体功耗。
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。 附图说明
下面结合附图, 通过对本发明的具体实施方式详细描述, 将使本发明 的技术方案及其它有益效果显而易见。
附图中,
图 1为目前常采用的栅极驱动电路架构示意图;
图 2a为阈值电压漂移前后薄膜晶体管整体电流对数与电压曲线关系变 化示意图;
图 2b为阈值电压漂移前后薄膜晶体管整体电流与电压曲线关系变化示 意图;
图 3为本发明具有自我补偿功能的栅极驱动电路单级架构示意图; 图 4 为本发明具有自我补偿功能的栅极驱动电路单级架构第一级连接 关系示意图;
图 5 为本发明具有自我补偿功能的栅极驱动电路单级架构最后一级连 接关系示意图;
图 6为图 3中采用的下拉維持模块第一实施例的电路图;
图 7a为阈值电压漂移前图 3所示的栅极驱动电路时序图;
图 7b为阈值电压漂移后图 3所示的栅极驱动电路时序图;
图 8为图 3中采用的下拉維持模块第二实施例的电路图;
图 9为图 3中采用的下拉維持模块第三实施例的电路图;
图 10为图 3中采用的下拉維持模块第四实施例的电路图。 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 3,为本发明具有自我补偿功能的栅极驱动电路单级架构示意 图。 包括: 级联的多个 GOA单元, 按照第 N级 GOA单元控制对显示区域 第 N级水平扫描线 G(N)充电, 该第 N级 GOA单元包括: 上拉控制模块 1、 上拉模块 2、 下传模块 3、 第一下拉模块 4、 自举电容模块 5、 及下拉維持 模块 6 ; 所述上拉模块 2、 第一下拉模块 4、 自举电容模块 5、 下拉維持电 路 6分别与第 N级栅极信号点 Q(N)和该第 N级水平扫描线 G(N)电性连接, 所述上拉控制模块 1与下传模块 3分别与该第 N级栅极信号点 Q(N)电性连 接, 所述下拉維持模块 6 输入第一直流低电压 VSS1 及第二直流低电压 VSS2。
所述下拉維持模块 6包括: 第一薄膜晶体管 Tl, 其栅极电性连接第一 电路点 Ρ(Ν), 漏极电性连接第 Ν级水平扫描线 G(N), 源极输入第一直流低 电压 VSS1 ; 第二薄膜晶体管 T2, 其栅极电性连接第一电路点 Ρ(Ν), 漏极 电性连接第 Ν级栅极信号点 Q(N), 源极输入第一直流低电压 VSS1 ; 第三 薄膜晶体管 T3, 其采用二极体接法, 栅极电性连接直流信号源 DC, 漏极 电性连接直流信号源 DC, 源极电性连接第二电路点 S(N) ; 第四薄膜晶体管 T4, 其栅极电性连接第 Ν 级栅极信号点 Q(N), 漏极电性连接第二电路点 S(N), 源极输入第一直流低电压 VSS1 ; 第五薄膜晶体管 T5, 其栅极电性连 接第 N-1级下传信号 ST(N-1), 漏极电性连接第一电路点 P(N), 源极输入第 一直流低电压 VSS1 ; 第六薄膜晶体管 T6, 其栅极电性连接第 N+1级水平 扫描线 G N+l), 漏极电性连接第一电路点 P N;), 源极电性连接第 N级栅极 信号点 Q(N:), 所述第六薄膜晶体管 T6 的控制端, 第 N+1 级水平扫描线 G N+1)也可以替换成接第 N+1级下传信号 ST N+l), 即第六薄膜晶体管 T6 的栅极可以电性连接于第 N+1 级下传信号 ST(N+1), 这样也可以降低第六 薄膜晶体管 T6的漏电影响; 第七薄膜晶体管 T7, 其栅极电性连接第 Ν级 下传信号 ST(N), 漏极电性连接第一电路点 P(N), 源极输入第一直流低电 压 VSS1 ; 第八薄膜晶体管 T8, 其栅极电性连接第一电路点 Ρ(Ν), 漏极电 性连接第 Ν级下传信号 ST(N), 源极输入第二直流低电压 VSS2 ; 第一电容 Cstl , 其上极板电性连接第二电路点 S(N), 下极板电性连接第一电路点 P(N)。
所述上拉控制模块 1 包括第九薄膜晶体管 T9, 其栅极输入来自第 N-1 级 GOA 单元的下传信号 ST(N-1), 漏极电性连接于第 N-1 级水平扫描线 G(N-l), 源极电性连接于该第 N级栅极信号点 Q(N) ; 所述上拉模块 2包括 第十薄膜晶体管 T10, 其栅极电性连接该第 Ν级栅极信号点 Q(N;), 漏极输 入第一高频时钟信号 CK或第二高频时钟信号 XCK, 源极电性连接于第 N 级水平扫描线 G N) ; 所述下传模块 3 包括第十一薄膜晶体管 Tll, 其栅极 电性连接该第 Ν级栅极信号点 Q(N;), 漏极输入第一高频时钟信号 CK或第 二高频时钟信号 XCK, 源极输出第 N级下传信号 ST(N) ; 所述第一下拉模 块 4 包括第十二薄膜晶体管 T12, 其栅极电性连接第 Ν+2 级水平扫描线 G(N+2), 漏极电性连接于第 N级水平扫描线 G(N), 源极输入第一直流低电 压 VSS1 ; 第十三薄膜晶体管 T13, 其栅极电性连接第 Ν+2 级水平扫描线 G(N+2), 漏极电性连接于该第 N级栅极信号点 Q(N), 源极输入第一直流低 电压 VSS1 ;所述第一下拉模块 4中第十二薄膜晶体管 T12的栅极与第十三 薄膜晶体管 T13的栅极均电性连接第 N+2级水平扫描线 G(N+2),主要是为 了实现第 N级栅极信号点 Q(N)电位呈三个阶段, 第一阶段是上升至一个高 电位并維持一段时间, 第二阶段在第一阶段的基础上又上升一个高电位并 維持一段时间, 第三阶段在第二阶段的基础上下降到与第一阶段基本持平 的高电位, 然后利用三个阶段中的第三阶段进行阈值电压的自我补偿; 所 述自举电容模块 5包括自举电容 Cb。
所述多级水平扫描线之间的级数是循环的,即当第 N级水平扫描线 G(N) 中的 N为最后一级 Last时, 第 N+2级水平扫描线 G(N+2)代表第二级水平 扫描线 G(2); 当第 N级水平扫描线 G(N)中的 N为倒数第二级 Last-1 时, 第 N+2级水平扫描线 G(N+2)代表第一级水平扫描线 G(l), 以此类推。
请参阅图 4并结合图 3, 图 4为本发明具有自我补偿功能的栅极驱动电 路单级架构第一级连接关系示意图, 即 N为 1 时的栅极驱动电路连接关系 示意图。 其中, 第五薄膜晶体管 T5的栅极电性连接于电路启动信号 STV; 第九薄膜晶体管 T9的栅极和漏极均电性连接于电路启动信号 STV。
请参阅图 5并结合图 3, 图 5为本发明具有自我补偿功能的栅极驱动电 路单级架构最后一级连接关系示意图, 即 N为最后一级 Last时的栅极驱动 电路连接关系示意图。 其中, 第六薄膜晶体管 T6的栅极电性连接于电路启 动信号 STV; 第十二薄膜晶体管 T12的栅极电性连接于第二级水平扫描线 G(2) ; 第十三薄膜晶体管 T13的栅极电性连接于第二级水平扫描线 G(2)。
请参阅图 6, 为图 3中采用的下拉維持模块第一实施例的电路图, 其中 控制信号源仅采用直流信号源 DC。 包括: 第一薄膜晶体管 Tl, 其栅极电 性连接第一电路点 Ρ(Ν), 漏极电性连接第 Ν级水平扫描线 G(N), 源极输入 第一直流低电压 VSS1 ; 第二薄膜晶体管 T2, 其栅极电性连接第一电路点 Ρ(Ν), 漏极电性连接第 Ν 级栅极信号点 Q(N), 源极输入第一直流低电压 VSS1 ; 第三薄膜晶体管 T3, 其采用二极体接法, 栅极电性连接直流信号源 DC, 漏极电性连接直流信号源 DC, 源极电性连接第二电路点 S(N); 第四 薄膜晶体管 T4, 其栅极电性连接第 Ν级栅极信号点 Q(N), 漏极电性连接 第二电路点 S(N), 源极输入第一直流低电压 VSS1, 第四薄膜晶体管 T4主 要在作用期间拉低第二电路点 S(N), 这样就可以实现通过第二电路点 S(N) 来控制第一电路点 P(N)电位的目的; 第五薄膜晶体管 T5, 其栅极电性连接 第 N-1级下传信号 ST(N-1), 漏极电性连接第一电路点 P(N), 源极输入第一 直流低电压 VSS1 ; 第六薄膜晶体管 T6, 其栅极电性连接第 N+1级水平扫 描线 G N+l), 漏极电性连接第一电路点 P N;), 源极电性连接第 N级栅极信 号点 Q(N:),所述第六薄膜晶体管 T6的控制端第 N+1级水平扫描线 G N+l) 也可以替换成接第 N+1 级下传信号 ST(N+1), 这样也可以降低第六薄膜晶 体管 T6的漏电影响; 这样设计的目的就是利用第 N级栅极信号点 Q(N)的 三个阶段中的第三阶段的电位进行阈值电压的侦测, 并将其电位存贮在第 一电路点 Ρ(Ν) ; 第七薄膜晶体管 Τ7, 其栅极电性连接第 Ν 级下传信号 ST(N), 漏极电性连接第一电路点 P(N;), 源极输入第一直流低电压 VSS1 ; 第八薄膜晶体管 T8, 其栅极电性连接第一电路点 Ρ(Ν:), 漏极电性连接第 Ν 级下传信号 ST(N:), 源极输入第二直流低电压 VSS2, 所述第八薄膜晶体管 T8主要负责将第 N级下传信号 ST(N)拉低到负电位第二直流低电压 VSS2。; 第一电容 Cstl, 其上极板电性连接第二电路点 S(N), 下极板电性连接第一 电路点 P(N)。
所述第三薄膜晶体管 T3栅极电性连接直流信号源 DC, 采用直流信号 源 DC可以降低电路整体的功耗,但是同时也会增加下拉維持模块 6的电压 应力作用。
请参阅图 7a、 7b并结合图 3, 图 7a为阈值电压漂移前图 3所示的栅极 驱动电路时序图,图 7b为阈值电压漂移后图 3所示的栅极驱动电路时序图。 在图 7a、 7b中, STV信号是电路启动信号, 第一高频时钟信号 CK与第二 高频时钟信号 XCK是一组相位完全相反的高频时钟信号源, DC是一个处 于高电位的直流信号源, G(N-1)是第 N-1 级水平扫描线, 即前一级的扫描 输出信号, ST(N-1)是第 N-1级下传信号, 即前一级的下传信号, Q(N-l)是 第 N-1级栅极信号点, 即前一级的栅极信号点, Q(N)是第 N级栅极信号点, 即本级的栅极信号点。
如图 7a、 7b所示, 第 N级栅极信号点 Q(N)电位呈三个阶段, 其中三 个阶段中的第三阶段的变化主要受第六薄膜晶体管 T6的影响。 由图 7a可 知, 在液晶面板刚点亮的初始时间 TO时, 阈值电压 Vth较小, 即栅极驱动 电路没经过长期搡作时,阈值电压 Vth未发生漂移,第 N级栅极信号点 Q(N) 的第三阶段电位较低, 与之对应的第一电路点 P(N)的电位也较低。 由图 7b 可知, 第 N级栅极信号点 Q(N)的第三阶段电位在电压应力作用下阈值电压 Vth 漂移后随之抬升, 这样就可以实现利用该部分来侦测第一薄膜晶体管 Tl与第二薄膜晶体管 T2的阈值电压的目的。
由图 7a与 7b可知图 3所示栅极驱动电路的工作过程为: 第 N+1级水 平扫描线 G N+l)导通时, 第六薄膜晶体管 T6打开, 此时第 N级栅极信号 点 Q(N)与第一电路点 P(N)的电位相同, 第二薄膜晶体管 T2等效成二极体 接法, 第一电路点 P(N)在第 N级栅极信号点 Q(N)的第三阶段, 可以通过第 六薄膜晶体管 T6存储第一薄膜晶体管 T1与第二薄膜晶体管 T2的阈值电压 的值, 那么, 随着阈值电压 Vth的漂移, 第 N级栅极信号点 Q(N)的第三阶 段的电位抬升, 第一电路点 P N)存贮的阈值电压的电位值也抬升, 然后, 第二电路点 S(N)再通过第一电容 Cstl来抬升第一电路点 P(N),这样就可以 补偿阈值电压的变化。
如图 7a、 7b所示, 阈值电压漂移前后, 第 N级栅极信号点 Q(N)与第 一电路点 P(N)的电位也发生了明显的变化, 尤其是第一电路点 P(N)的电位 的增加能够有效地降低阈值电压漂移对第一薄膜晶体管 T1与第二薄膜晶体 管 T2开态电流的影响, 从而确保第 N级水平扫描线 G(N)和第 N级栅极信 号点 Q(N)能够在长期搡作后, 依然很好地維持在低电位状态。
如果第一薄膜晶体管 T1与第二薄膜晶体管 T2的阈值电压 Vth发生正 向的漂移, 逐渐变大的话, 第六薄膜晶体管 T6就会存贮一个较高的阈值电 压值到第一电路点 P(N), 那么, 在自举抬升之后第一电路点 P(N)的电位会 变得更高, 这样就可以补偿阈值电压 Vth 增加带来的负面效果, 实现下拉 維持模块自我补偿的作用, 可以有效地提高下拉維持模块的可靠性; 而且 采用这种自我补偿式的下拉維持模块设计, 可以不需要设计两个交替工作 的模块, 仅设计一个由直流信号源控制的下拉維持模块即可, 这样即可以 降低功耗, 又可以节省版图设计空间。
请参阅图 8并结合图 6, 图 8为图 3采用的下拉維持模块第二实施例的 电路图。 图 8是在图 6的基础上增加一个第二电容 Cst2, 其上极板电性连 接第一电路点 P(N;), 下极板输入第一直流低电压 VSS1 , 第二电容 Cst2的 主要作用就是存贮阈值电压。 由于第一薄膜晶体管 T1 与第二薄膜晶体管 T2本身存在一定的寄生电容, 可以起到第二电容 Cst2的作用, 因此, 在实 际电路设计中第二电容 Cst2可以去掉。
请参阅图 9并结合图 6, 图 9为图 3采用的下拉維持模块第三实施例的 电路图。 图 9是在图 6的基础上增加一个第十四薄膜晶体管 T14, 其栅极电 性连接第 N+1 级水平扫描线 G(N+1), 漏极电性连接第二电路点 S(N), 源 极输入第一直流低电压 VSS1 ;该第十四薄膜晶体管 T14的主要目的是弥补 第 N级栅极信号点 Q(N)第一阶段电位不高,而导致的第二电路点 S(N)作用 期间电位下拉不够低。
请参阅图 10并结合图 6, 图 10为图 3采用的下拉維持模块第四实施例 的电路图。 图 10是在图 6的基础上增加: 第二电容 Cst2, 其上极板电性连 接第一电路点 P(N), 下极板输入第一直流低电压 VSS1 ; 第十四薄膜晶体管 T14, 其栅极电性连接第 N+1级水平扫描线 G(N+1), 漏极电性连接第二电 路点 S(N), 源极输入第一直流低电压 VSS1。
图 3所示的栅极驱动电路单级架构中下拉維持模块 6可以替换为图 6、 图 8、 图 9、 图 10 中的任意一种下拉維持模块设计方案, 其替换后的栅极 驱动电路时序图与图 7a、 图 7b相同, 其工作过程与图 3所示的栅极驱动电 路相同, 因此不再赘述。
综上所述, 本发明提供一种具有自我补偿功能的栅极驱动电路, 针对 现有栅极驱动电路架构中下拉維持模块受到电压应力严重、 最容易失效的 问题, 利用电容的自举作用来控制下拉維持模块的第一电路点 P(N), 设计 能够检测薄膜晶体管阈值电压的功能, 并将阈值电压存贮在第一电路点 P(N), 进而实现第一电路点 P(N)的控制电压随着薄膜晶体管的阈值电压漂 移而变化。 本发明通过设计具有自我补偿功能的下拉維持模块来提高栅极 驱动电路长期搡作的可靠性, 降低阈值电压漂移对栅极驱动电路运作的影 响;还可以设计成直接由一组直流信号源 DC控制的下拉維持模块, 既可以 节省电路版图设计空间, 又可以降低电路的整体功耗。
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

权 利 要 求
1、 一种具有自我补偿功能的栅极驱动电路, 包括: 级联的多个 GOA 单元, 按照第 N级 GOA单元控制对显示区域第 N级水平扫描线充电, 该 第 N级 GOA单元包括: 上拉控制模块、 上拉模块、 下传模块、 第一下拉模 块、 自举电容模块、 及下拉維持模块; 所述上拉模块、 第一下拉模块、 自 举电容模块、 下拉維持电路分别与第 N级栅极信号点和该第 N级水平扫描 线电性连接, 所述上拉控制模块与下传模块分别与该第 N级栅极信号点电 性连接, 所述下拉維持模块输入第一直流低电压及第二直流低电压;
所述下拉維持模块包括: 第一薄膜晶体管, 其栅极电性连接第一电路 点, 漏极电性连接第 N级水平扫描线, 源极输入第一直流低电压; 第二薄 膜晶体管, 其栅极电性连接第一电路点, 漏极电性连接第 N级栅极信号点, 源极输入第一直流低电压; 第三薄膜晶体管, 其栅极电性连接直流信号源, 漏极电性连接直流信号源, 源极电性连接第二电路点; 第四薄膜晶体管, 其栅极电性连接第 N级栅极信号点, 漏极电性连接第二电路点, 源极输入 第一直流低电压; 第五薄膜晶体管, 其栅极电性连接第 N-1 级下传信号, 漏极电性连接第一电路点, 源极输入第一直流低电压; 第六薄膜晶体管, 其栅极电性连接第 N+1级水平扫描线, 漏极电性连接第一电路点, 源极电 性连接第 N级栅极信号点; 第七薄膜晶体管, 其栅极电性连接第 N级下传 信号, 漏极电性连接第一电路点, 源极输入第一直流低电压; 第八薄膜晶 体管, 其栅极电性连接第一电路点, 漏极电性连接第 N级下传信号, 源极 输入第二直流低电压; 第一电容, 其上极板电性连接第二电路点, 下极板 电性连接第一电路点。
2、 如权利要求 1所述的具有自我补偿功能的栅极驱动电路, 其中, 所 述上拉控制模块包括第九薄膜晶体管,其栅极输入来自第 N-1级 GOA单元 的下传信号, 漏极电性连接于第 N-1 级水平扫描线, 源极电性连接于该第 N 级栅极信号点; 所述上拉模块包括第十薄膜晶体管, 其栅极电性连接该 第 N级栅极信号点, 漏极输入第一高频时钟信号或第二高频时钟信号, 源 极电性连接于第 N级水平扫描线; 所述下传模块包括第十一薄膜晶体管, 其栅极电性连接该第 N级栅极信号点, 漏极输入第一高频时钟信号或第二 高频时钟信号, 源极输出第 N级下传信号; 所述第一下拉模块包括第十二 薄膜晶体管, 其栅极电性连接第 N+2级水平扫描线, 漏极电性连接于第 N 级水平扫描线, 源极输入第一直流低电压; 第十三薄膜晶体管, 其栅极电 性连接第 N+2级水平扫描线, 漏极电性连接于该第 N级栅极信号点, 源极 输入第一直流低电压; 所述自举电容模块包括自举电容。
3、 如权利要求 1所述的具有自我补偿功能的栅极驱动电路, 其中, 所 述栅极驱动电路的第一级连接关系中, 第五薄膜晶体管的栅极电性连接于 电路启动信号; 第九薄膜晶体管的栅极和漏极均电性连接于电路启动信号。
4、 如权利要求 1所述的具有自我补偿功能的栅极驱动电路, 其中, 所 述栅极驱动电路的最后一级连接关系中, 第六薄膜晶体管的栅极电性连接 于电路启动信号; 第十二薄膜晶体管的栅极电性连接于第二级水平扫描线; 第十三薄膜晶体管的栅极电性连接于第二级水平扫描线。
5、 如权利要求 1所述的具有自我补偿功能的栅极驱动电路, 其中, 所 述下拉維持模块还包括: 第二电容, 其上极板电性连接第一电路点, 下极 板输入第一直流低电压。
6、 如权利要求 1所述的具有自我补偿功能的栅极驱动电路, 其中, 所 述下拉維持模块还包括: 第十四薄膜晶体管, 其栅极电性连接第 N+1级水 平扫描线, 漏极电性连接第二电路点, 源极输入第一直流低电压。
7、 如权利要求 1所述的具有自我补偿功能的栅极驱动电路, 其中, 所 述下拉維持模块还包括: 第二电容, 其上极板电性连接第一电路点, 下极 板输入直流低电压; 第十四薄膜晶体管, 其栅极电性连接第 N+1级水平扫 描线, 漏极电性连接第二电路点, 源极输入第一直流低电压。
8、 如权利要求 2所述的具有自我补偿功能的栅极驱动电路, 其中, 所 述第一高频时钟信号与第二高频时钟信号是两个相位完全相反的高频时钟 信号源。
9、 如权利要求 2所述的具有自我补偿功能的栅极驱动电路, 其中, 所 述第一下拉模块中第十二薄膜晶体管的栅极与第十三薄膜晶体管的栅极均 电性连接第 N+2级水平扫描线, 主要为了实现第 N级栅极信号点电位呈三 个阶段, 第一阶段是上升至一个高电位并維持一段时间, 第二阶段在第一 阶段的基础上又上升一个高电位并維持一段时间, 第三阶段在第二阶段的 基础上下降到与第一阶段基本持平的高电位, 然后利用三个阶段中的第三 阶段进行阈值电压的自我补偿。
10、 如权利要求 9 所述的具有自我补偿功能的栅极驱动电路, 其中, 所述第 N级栅极信号点电位呈三个阶段, 其中第三阶段的变化主要受第六 薄膜晶体管的影响。
11、 如权利要求 1 所述的具有自我补偿功能的栅极驱动电路, 其中, 所述第六薄膜晶体管的栅极可以电性连接于第 N+1级下传信号。
12、 如权利要求 1 所述的具有自我补偿功能的栅极驱动电路, 其中, 所述第二直流低电压为负压源, 该第二直流低电压的电位低于第一直流低 电压。
13、 一种具有自我补偿功能的栅极驱动电路, 包括: 级联的多个 GOA 单元, 按照第 N级 GOA单元控制对显示区域第 N级水平扫描线充电, 该 第 N级 GOA单元包括: 上拉控制模块、 上拉模块、 下传模块、 第一下拉模 块、 自举电容模块、 及下拉維持模块; 所述上拉模块、 第一下拉模块、 自 举电容模块、 下拉維持电路分别与第 N级栅极信号点和该第 N级水平扫描 线电性连接, 所述上拉控制模块与下传模块分别与该第 N级栅极信号点电 性连接, 所述下拉維持模块输入第一直流低电压及第二直流低电压;
所述下拉維持模块包括: 第一薄膜晶体管, 其栅极电性连接第一电路 点, 漏极电性连接第 N级水平扫描线, 源极输入第一直流低电压; 第二薄 膜晶体管, 其栅极电性连接第一电路点, 漏极电性连接第 N级栅极信号点, 源极输入第一直流低电压; 第三薄膜晶体管, 其栅极电性连接直流信号源, 漏极电性连接直流信号源, 源极电性连接第二电路点; 第四薄膜晶体管, 其栅极电性连接第 N级栅极信号点, 漏极电性连接第二电路点, 源极输入 第一直流低电压; 第五薄膜晶体管, 其栅极电性连接第 N-1 级下传信号, 漏极电性连接第一电路点, 源极输入第一直流低电压; 第六薄膜晶体管, 其栅极电性连接第 N+1级水平扫描线, 漏极电性连接第一电路点, 源极电 性连接第 N级栅极信号点; 第七薄膜晶体管, 其栅极电性连接第 N级下传 信号, 漏极电性连接第一电路点, 源极输入第一直流低电压; 第八薄膜晶 体管, 其栅极电性连接第一电路点, 漏极电性连接第 N级下传信号, 源极 输入第二直流低电压; 第一电容, 其上极板电性连接第二电路点, 下极板 电性连接第一电路点;
其中, 所述上拉控制模块包括第九薄膜晶体管, 其栅极输入来自第 N-1 级 GOA单元的下传信号, 漏极电性连接于第 N-1级水平扫描线, 源极电性 连接于该第 N级栅极信号点; 所述上拉模块包括第十薄膜晶体管, 其栅极 电性连接该第 N级栅极信号点, 漏极输入第一高频时钟信号或第二高频时 钟信号, 源极电性连接于第 N级水平扫描线; 所述下传模块包括第十一薄 膜晶体管, 其栅极电性连接该第 N级栅极信号点, 漏极输入第一高频时钟 信号或第二高频时钟信号, 源极输出第 N级下传信号; 所述第一下拉模块 包括第十二薄膜晶体管, 其栅极电性连接第 N+2级水平扫描线, 漏极电性 连接于第 N级水平扫描线, 源极输入第一直流低电压; 第十三薄膜晶体管, 其栅极电性连接第 N+2级水平扫描线, 漏极电性连接于该第 N级栅极信号 点, 源极输入第一直流低电压; 所述自举电容模块包括自举电容; 其中, 所述栅极驱动电路的第一级连接关系中, 第五薄膜晶体管的栅 极电性连接于电路启动信号; 第九薄膜晶体管的栅极和漏极均电性连接于 电路启动信号。
其中, 所述栅极驱动电路的最后一级连接关系中, 第六薄膜晶体管的 栅极电性连接于电路启动信号; 第十二薄膜晶体管的栅极电性连接于第二 级水平扫描线; 第十三薄膜晶体管的栅极电性连接于第二级水平扫描线; 其中, 所述第一高频时钟信号与第二高频时钟信号是两个相位完全相 反的高频时钟信号源;
其中, 所述第一下拉模块中第十二薄膜晶体管的栅极与第十三薄膜晶 体管的栅极均电性连接第 N+2级水平扫描线, 主要为了实现第 N级栅极信 号点电位呈三个阶段, 第一阶段是上升至一个高电位并維持一段时间, 第 二阶段在第一阶段的基础上又上升一个高电位并維持一段时间, 第三阶段 在第二阶段的基础上下降到与第一阶段基本持平的高电位, 然后利用三个 阶段中的第三阶段进行阈值电压的自我补偿;
其中, 所述第 N级栅极信号点电位呈三个阶段, 其中第三阶段的变化 主要受第六薄膜晶体管的影响;
其中,所述第六薄膜晶体管的栅极可以电性连接于第 N+1级下传信号; 其中, 所述第二直流低电压为负压源, 该第二直流低电压的电位低于 第一直流低电压。
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