WO2014146339A1 - 像素电路及其驱动方法、阵列基板、显示装置 - Google Patents

像素电路及其驱动方法、阵列基板、显示装置 Download PDF

Info

Publication number
WO2014146339A1
WO2014146339A1 PCT/CN2013/075160 CN2013075160W WO2014146339A1 WO 2014146339 A1 WO2014146339 A1 WO 2014146339A1 CN 2013075160 W CN2013075160 W CN 2013075160W WO 2014146339 A1 WO2014146339 A1 WO 2014146339A1
Authority
WO
WIPO (PCT)
Prior art keywords
switching transistor
transistor
driving
pole
pixel circuit
Prior art date
Application number
PCT/CN2013/075160
Other languages
English (en)
French (fr)
Inventor
曾勉
尹傛俊
涂志中
金在光
Original Assignee
合肥京东方光电科技有限公司
京东方科技集团股份有限公司
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 合肥京东方光电科技有限公司, 京东方科技集团股份有限公司 filed Critical 合肥京东方光电科技有限公司
Priority to US14/344,666 priority Critical patent/US20150145853A1/en
Publication of WO2014146339A1 publication Critical patent/WO2014146339A1/zh

Links

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
    • 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

Definitions

  • Pixel circuit and driving method thereof array substrate, display device
  • OLED Display Organic Light Emitting Diode Display
  • TFT-LCD Thin Film Transistor Liquid Crystal Display
  • the driving method of the organic light emitting display is divided into a passive matrix type (PM, Passive Matrix) and an active matrix type (AM, Active Matrix).
  • PM Passive Matrix
  • AM Active Matrix
  • An equivalent circuit of a pixel unit driving circuit of an active matrix organic light emitting display of the prior art, as shown in FIG. 1, includes: a first switching transistor M1, a driving transistor M2, a storage capacitor C1, and a light emitting device D1.
  • the source of the first switching transistor M1 is connected to the gate of the driving transistor M2; the gate of the driving transistor M2 is simultaneously connected to one end of the storage capacitor C1, and the drain thereof is connected to the other end of the storage capacitor C1, and the source and the light emitting device thereof D1 connection.
  • the first switching transistor M1 is turned on when the gate is gated by the scan signal Vscan(n), and the data signal Vdata is input from the drain.
  • the driving transistor M2 generally operates in a saturation region, and its gate-source voltage Vgs determines the magnitude of the current flowing through it, thereby providing a stable current for the light-emitting device D1.
  • Vgs Vdata -VDl
  • VD1 is the turn-on voltage of the light-emitting device D1
  • VDD is a voltage-stabilized or steady-current power supply, and is connected to the driving transistor M2 for providing the energy required for the light-emitting device D1 to emit light.
  • the function of the storage capacitor C1 is to maintain the stability of the gate voltage of the driving transistor M2 for one frame.
  • the pixel unit of the nth row is gated, the first switching transistor M1 of the row of pixel units is turned on, and the data signal Vdata is introduced for driving, the light emitting device D1 Start to shine.
  • the light-emitting device D1 is caused to emit light by the high level of the data signal Vdata, and the charging of the storage capacitor C1 in the row of pixel units is completed.
  • the first low level of the scanning signal Vscan(n) is turned off to turn off the row of the pixel unit.
  • the storage capacitor C1 maintains the voltage at the time of charging, and maintains the driving transistor M2 of the row of pixel units.
  • a stable current is output such that the organic light-emitting diode D1 of the row of pixel units continues to emit light until the end of one frame time.
  • One frame time is usually the time interval in which the same row of pixel units are strobed twice in succession.
  • the scan signal strobes the n+1th row of pixel units, turns on the first switching transistor M1 of the n+1th row of pixel units, and introduces a driving data signal to perform the same charging process, charging
  • the voltage at the time of charging is maintained by the storage capacitor C1 in the pixel unit, and the driving tube outputs a stable current, so that the light-emitting device D1 of the n+1-row pixel unit continues to emit light until the end of one frame time. In this way, when the charging of the last row of pixel units is completed, the charging is resumed from the first row of pixel units.
  • the threshold voltage Vth of the driving transistor M2 may drift as the use time increases, resulting in Vgs for the same data signal Vdata.
  • the current (that is, the brightness) of the light-emitting device D1 is different, which will affect the image uniformity of the entire organic light-emitting display and its light-emitting quality.
  • a pixel circuit including: a driving transistor, a first switching transistor, a storage capacitor, a light emitting device tube, and a threshold compensation circuit;
  • the threshold compensation circuit includes a second switching transistor, a third switching transistor a fourth switching transistor and a coupling capacitor;
  • a first scan signal is connected to the first scan signal, a second end of the first switch transistor is connected to the data signal input end, and a third end of the first switch transistor is connected to the first end of the storage capacitor and the coupling capacitor a first end and a second pole of the second switching transistor;
  • the gate of the fourth switching transistor is connected to the first control signal, and the third terminal of the fourth switching transistor is connected to the light emitting device;
  • a second end of the coupling capacitor is coupled to a gate of the drive transistor.
  • a threshold compensation circuit including a second switching transistor, a third switching transistor, a fourth switching transistor, and a coupling capacitor is used to compensate for a threshold voltage drift of the driving transistor, and can effectively compensate for a threshold voltage of the driving transistor.
  • the uniformity of the organic light-emitting display is improved.
  • the first switching transistor, the second switching transistor, the third switching transistor, the fourth switching transistor and the driving transistor are N-type thin film transistors, wherein the second electrode is a drain and the third electrode is a source.
  • the light emitting device is an organic light emitting diode.
  • Precharging stage stroking the second scan signal and the power supply voltage, so that the second switching transistor and the third switching transistor are turned on, and the stored charge of the coupling capacitor is released; compensation phase: stroking the first a scan signal, causing the first switching transistor to be turned on, turning off the second scan signal, so that the data signal is input to the first end of the coupling capacitor and the first end of the storage capacitor, and the voltage of the second end of the coupling capacitor is increased High and turning on the driving thin film transistor;
  • Illuminating phase stroking the control signal, causing the fourth switching transistor to be turned on, the storage capacitor maintaining a voltage of the first end of the coupling capacitor, the driving transistor continues to be in an on state, driving the light emitting device to emit light .
  • the driving method of the pixel circuit is simple and easy to control.
  • an array substrate that includes the pixel circuit described above. Since the array substrate of the present invention includes the above-described pixel circuit, its performance is stable.
  • a display device comprising the above array substrate. Since the display device of the present invention includes the above array substrate, the picture uniformity is high.
  • 1 is a schematic diagram of a conventional pixel circuit
  • FIG. 2 is a circuit diagram of a pixel circuit according to an embodiment of the present invention.
  • Figure 3 is a timing diagram of the pixel circuit of Figure 2.
  • the reference numerals are: M1, the first switching transistor; the DTFT, the driving transistor; the M2, the second switching transistor; the M3, the third switching transistor; the M4, the fourth switching transistor; Cl, the storage capacitor; C2, the coupling capacitor; Dl, light emitting device; Vdata, data signal; Vscan (n), first scan signal; Vscan (n-1), second scan signal; EM, first control signal.
  • the gate of M1 of the first switching transistor is connected to the first scan signal Vscan(n), the drain is connected to the data signal input terminal Vdata, and the source is connected to the first end of the storage capacitor C1, the first end of the coupling capacitor C2, and the second switch.
  • the second terminal of the storage capacitor C1 is connected to the power supply voltage Vdd and is connected to the drain of the driving transistor DTFT;
  • the gate of the second switching transistor M2 is connected to the second scan signal Vscan (nl) simultaneously connected to the gate of the third switching transistor M3, the source is connected to the negative terminal Vss of the power supply; a drain of the third switching transistor M3 is connected to a gate of the driving transistor DTFT, and a source is connected to a source of the driving transistor DTFT to a drain of the fourth switching transistor M4; the fourth switching transistor The gate of M4 is connected to the first control signal EM, and the source is connected to the light emitting device D1;
  • the second end of the coupling capacitor C2 is connected to the gate of the driving transistor DTFT.
  • the light emitting device D1 is an organic light emitting diode
  • the first switching transistor M1, the second switching transistor M2, the third switching transistor M3, the fourth switching transistor M4, and the driving transistor DTFT are N-type thin film transistors.
  • all the switching tubes only function as switches, and may also be P-type transistors, and the signals of the switching tubes are turned on or off accordingly. Since the source and drain of the switching transistor used herein are symmetrical, the source and drain are interchangeable.
  • one of the poles is referred to as a source and the other pole is referred to as a drain. If the source is selected as the signal input, the drain acts as the signal output and vice versa.
  • the operation is divided into three phases: a precharge phase, a compensation phase, and an illumination phase.
  • the first stage is the pre-charging stage C.
  • the scanning signal strobes the pixel unit of the n-1th row
  • the second scanning signal Vscan(nl) corresponding to the pixel unit of the n-1th row is at a high level
  • the second switching transistor M2 The third switching transistor M3 remains on, and the first scan signal Vscan(n) corresponding to the nth row of pixel units is at a low level, the first switching transistor M1 is turned off, the first control signal EM is at a low level, and the fourth switch Transistor M4 also remains off.
  • the voltage at the point A of the drain of the second switching transistor M2 and the voltage at the point B of the gate of the driving transistor DTFT start to decrease, and the charge stored in the coupling capacitor C2 is released, and the voltage across the coupling capacitor C2 is at this time.
  • the second stage is the compensation stage D.
  • the scan signal strobes the nth row of pixel units
  • the second scan signal Vscan(nl) corresponding to the pixel of the n-1th row is low level, and the second switching transistor M2, the third The switching transistor M3 is turned off, and the first scan signal Vscan(n) corresponding to the pixel row of the nth row is at a high level, the first switching transistor M1 is turned on, the data signal Vdata on the data line is introduced, and the storage capacitor C1 is charged to be stored.
  • the data signal Vdata Subsequently, the data signal Vdata raises the voltage at point A to Vdata. Due to the coupling capacitor C2, the voltage at the gate B of the thin film transistor rises to Vdata+Vth, and the driving thin film transistor maintains a conduction critical state.
  • the third stage is the lighting stage E: the first control signal EM is connected to the high level to control the fourth switching transistor M4 to be turned on. Since the power supply voltage Vdd is much larger than the data voltage Vdata, the driving transistor DTFT is turned on, and the power supply voltage Vdd is illuminated by the driving transistor DTFT. The output current of the device D1 is driven by the light-emitting device D1 to emit light.
  • the current flowing through the driving transistor DTFT at this time can be expressed by the following formula:
  • the circuit can effectively compensate for the non-uniformity of the threshold voltage of the driving transistor, so that the picture uniformity of the display device is improved without using an external compensation circuit for the threshold. Voltage compensation, which reduces R&D and manufacturing costs. Moreover, the timing of the pixel is easy to implement.
  • the first switching transistor, the second switching transistor, the third switching transistor, the fourth switching transistor, and the driving transistor are N-type thin film transistors.
  • the light emitting device is an organic light emitting diode, and of course other light emitting devices are also possible.
  • Example 2 is an organic light emitting diode, and of course other light emitting devices are also possible.
  • the embodiment provides a driving method of the above pixel circuit, including the following steps: pre-charging stage: stroking the second scan signal Vscan(nl) and the power voltage Vdd, the second switching transistor M2 and the third The switching transistor M3 is turned on, and the coupling capacitor C2 The stored charge is released until the voltage at the second end of the coupling capacitor C2 is the threshold voltage of the driving transistor DTFT;
  • the illuminating phase strobing the first control signal EM, the fourth switching transistor M4 is turned on, and the driving transistor DTFT continues to be in an on state to drive the illuminating device to emit light D1.
  • Example 3 The specific implementation of the method is the same as that of the first embodiment, and is not described here. The method is easy to implement, so the applicability is wider.
  • Example 3 The specific implementation of the method is the same as that of the first embodiment, and is not described here. The method is easy to implement, so the applicability is wider.
  • an array substrate which includes a plurality of data lines and a plurality of scan lines.
  • the data lines and the scan lines are arranged at intersection, and the pixel circuit in Embodiment 1 is provided at the intersection.
  • the embodiment provides a display device, and the array substrate of the organic light-emitting display device in the display device is as described in Embodiment 3, and is not described in detail herein.
  • the display device in this embodiment may include: an OLED panel, a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, a navigation device, and the like, or any product or component having a display function.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Control Of Indicators Other Than Cathode Ray Tubes (AREA)
  • Electroluminescent Light Sources (AREA)

Abstract

一种像素电路及其驱动方法、阵列基板、显示装置，像素电路包括：驱动晶体管（DTFT）、第一开关晶体管（Ml）、存储电容（C1）、发光器件以及阈值补偿电路，阈值补偿电路由第二开关晶体管（M2）、第三开关晶体管（M3）、第四开关晶体管（M4）以及耦合电容（C2）构成，其可以有效补偿驱动晶体管（DTFT）阈值电压的不均匀性。驱动方法包括：预充阶段（C）、补偿阶段（D）以及发光阶段（E）。阵列基板包括上述像素单元电路，其性能更加稳定。显示装置包括上述阵列基板，其大大提高了画面的均匀性。

Description

像素电路及其驱动方法、 阵列基板、 显示装置
技术领域
本发明属于有机发光显示技术领域，具体涉及一种像素电路及其驱动 方法、 阵列基板、 显示装置。 背景技术
有机发光显示器 (Organic Light Emitting Diode Display, OLED Display) 相比现在的主流显示技术薄膜晶体管液晶显示器（Thin Film Transistor Liquid Crystal Display, TFT-LCD), 具有广视角、 高亮度、 高对比度、 低能 耗、 体积更轻薄等优点， 是目前平板显示技术关注的焦点。
有机发光显示器的驱动方法分为被动矩阵式 (PM, Passive Matrix)和主 动矩阵式 (AM, Active Matrix)两种。 而相比被动矩阵式驱动，主动矩阵式驱 动具有显示信息量大、 功耗低、 器件寿命长、 画面对比度高等优点。 现有 技术的一种主动矩阵式有机发光显示器的像素单元驱动电路的等效电路， 如图 1所示， 包括： 第一开关晶体管 Ml、 驱动晶体管 M2、 存储电容 C1 以及发光器件 Dl。 其中， 第一开关晶体管 Ml的源极与驱动晶体管 M2的 栅极连接； 驱动晶体管 M2的栅极同时连接存储电容 C1 的一端， 其漏极 与存储电容 C1另一端连接，其源极与发光器件 D1连接。第一开关晶体管 Ml在栅极被扫描信号 Vscan(n)选通时打开， 从漏极 |入数据信号 Vdata。 驱动晶体管 M2—般工作在饱和区， 其栅源电压 Vgs决定了流过其电流的 大小，进而为发光器件 D1提供了稳定的电流。其中 Vgs=Vdata -VDl , VD1 为发光器件 Dl的开启电压， VDD为稳压或者稳流电源， 连接驱动晶体管 M2, 用于提供发光器件 D1发光所需要的能源。 而存储电容 C1的作用是 在一帧的时间内维持驱动晶体管 M2栅极电压的稳定。
当扫描信号 Vscan(n)的第一个高电平开始时，第 n行像素单元被选通， 将该行像素单元中的第一开关晶体管 Ml打开， 引入数据信号 Vdata进行 驱动， 发光器件 D1开始发光。 通过数据信号 Vdata的高电平使发光器件 D1发光， 完成该行像素单元中的存储电容 C1的充电， 之后， 通过扫描信 号 Vscan(n)的第一个低电平关闭该行像素单元的第一开关晶体管 Ml。 此 时，存储电容 C1维持充电时的电压， 维持该行像素单元的驱动晶体管 M2 输出稳定的电流， 使得该行像素单元的有机发光二级管 D1持续发光直到 一帧时间结束。 一帧时间通常为同一行像素单元连续两次被扫描信号选通 的时间间隔。
在第 n行像素单元的充电完成后， 扫描信号选通第 n+1行像素单元， 将第 n+1行像素单元的第一开关晶体管 Ml打开， 引入驱动数据信号进行 同样的充电过程， 充电完成后通过像素单元中的存储电容 C1 维持充电时 的电压， 维持驱动管输出稳定电流， 使得 n+1行像素单元的发光器件 D1 持续发光直到一帧时间结束。 如此依序下去， 当对最后一行像素单元充电 完成后， 便又从第一行像素单元开始重新扫描充电。
尽管现有技术像素单元电路被广泛使用，但是其仍然必不可免的存在 以下问题： 驱动晶体管 M2的阈值电压 Vth会随着使用时间的增加而出现 漂移， 从而导致针对同样的数据信号 Vdata的 Vgs出现变化， 即发光器件 D1 的电流（也就是亮度） 不同， 从而将会影响整个有机发光显示器的画 面均勾性及其发光质量。 发明内容
本发明实施例所要解决的技术问题包括，针对现有的像素单元电路中 由于驱动晶体管阈值电压漂移等原因引起电路不稳定， 导致有机发光显示 器的画面均勾性及其发光质量差的问题， 提供一种可以有效地补偿驱动晶 体管阈值电压的不均匀性， 使得有机发光显示器的画面均匀性提高的像素 电路及其驱动方法、 阵列基板及显示装置。
根据本发明的实施例， 提供了一种像素电路， 包括： 驱动晶体管、 第 一开关晶体管、 存储电容、 发光器件管以及阈值补偿电路； 所述阈值补偿 电路包括第二开关晶体管、 第三开关晶体管、 第四开关晶体管以及耦合电 容；
所述第一开关晶体管的栅极接第一扫描信号，所述第一开关晶体管的 第二极接数据信号输入端， 所述第一开关晶体管的第三极接存储电容第一 端、 耦合电容的第一端以及第二开关晶体管的第二极；
所述存储电容的第二端接电源电压同时接所述驱动晶体管的第二极； 所述第二开关晶体管的栅极接第二扫描信号同时接所述第三开关晶 体管的栅极， 所述第二开关晶体管的第三极接电源负极端； 所述第三开关晶体管的第二极接所述驱动晶体管的栅极，所述第三开 关晶体管的第三极接所述驱动晶体管的第三极同时接所述第四开关晶体 管的第二极；
所述第四开关晶体管的栅极接第一控制信号，所述第四开关晶体管的 第三极接所述发光器件；
所述耦合电容的第二端与所述驱动晶体管的栅极相连。
本发明的像素电路中， 包括第二开关晶体管、 第三开关晶体管、 第四 开关晶体管以及耦合电容的阈值补偿电路， 用于补偿驱动晶体管的阈值电 压漂移， 可以有效地补偿驱动晶体管阈值电压的不均勾性， 使得有机发光 显示器的画面均匀性提高。
优选地， 所述第一开关晶体管、 第二开关晶体管、 第三开关晶体管、 第四开关晶体管和所述驱动晶体管为 N型薄膜晶体管， 其中第二极是漏 极， 第三极是源极。
优选地， 所述第一开关晶体管、 第二开关晶体管、 第三开关晶体管、 第四开关晶体管和所述驱动晶体管为 P型薄膜晶体管，其中第二极是源极， 第三极是漏极。
优选地， 所述发光器件为有机发光二极管。
根据本发明的实施例， 还提供了一种用于上述像素电路的驱动方法， 包括如下步骤：
预充阶段： 选通所述第二扫描信号以及所述电源电压， 使得所述第二 开关晶体管和第三开关晶体管开启， 所述耦合电容储存的电荷进行释放； 补偿阶段： 选通所述第一扫描信号， 使得所述第一开关晶体管开启， 关断第二扫描信号， 使得数据信号输入所述耦合电容的第一端和存储电容 的第一端， 所述耦合电容的第二端的电压升高并开启所述驱动薄膜晶体 管；
发光阶段： 选通所述控制信号， 使得所述第四开关晶体管开启， 所述 存储电容保持所述耦合电容第一端的电压， 所述驱动晶体管继续保持导通 状态， 驱动所述发光器件发光。
该像素电路的驱动方法， 时序筒单， 容易控制。
根据本发明的一实施例， 提供了一种阵列基板， 其包括上述的像素电 路。 由于本发明的阵列基板中包括上述的像素电路， 故其性能稳定。
根据本发明的一实施例， 提供了一种显示装置， 其包括上述的阵列基 由于本发明的显示装置中包括上述的阵列基板， 故其画面均匀性高。
附图说明
图 1为现有的像素电路的原理图；
图 2为本发明的实施例提供的像素电路的电路图；
图 3为图 2中像素电路的时序图。
其中附图标记为： Ml、 第一开关晶体管； DTFT、 驱动晶体管； M2、 第二开关晶体管； M3、 第三开关晶体管； M4、 为第四开关晶体管； Cl、 存储电容； C2、 耦合电容； Dl、 发光器件； Vdata、 数据信号； Vscan ( n )、 第一扫描信号； Vscan ( n-1 )、 第二扫描信号； EM、 第一控制信号。 具体实施方式
为使本领域技术人员更好地理解本发明的技术方案，下面结合附图和 具体实施方式对本发明作进一步详细描述。 实施例 1 :
本实施例提供一种像素电路， 如图 2所示， 包括： 驱动晶体管 DTFT、 第一开关晶体管 Ml、 存储电容 Cl、 发光器件以及阈值补偿电路； 所述阈 值补偿电路包括第二开关晶体管 M2、 第三开关晶体管 M3、 第四开关晶体 管 M4以及 合电容 C2;
所述第一开关晶体管的 Ml栅极接第一扫描信号 Vscan ( n ), 漏极接 数据信号输入端 Vdata, 源极接存储电容 C1第一端、 耦合电容 C2的第一 端以及第二开关晶体管 M2的漏极；
所述存储电容 C1 的第二端接电源电压 Vdd 同时接所述驱动晶体管 DTFT的漏极；
所述第二开关晶体管 M2的栅极接第二扫描信号 Vscan(n-l)同时接所 述第三开关晶体管 M3的栅极， 源极接电源负极端 Vss; 所述第三开关晶体管 M3的漏极接所述驱动晶体管 DTFT的栅极， 源 极接所述驱动晶体管 DTFT的源极同时接所述第四开关晶体管 M4的漏极； 所述第四开关晶体管 M4的栅极接第一控制信号 EM, 源极接所述发 光器件 D1 ;
所述耦合电容 C2的第二端与所述驱动晶体管 DTFT的栅极相连。 具体地， 所述发光器件 D1为有机发光二极管， 所述第一开关晶体管 Ml、 第二开关晶体管 M2、 第三开关晶体管 M3、 第四开关晶体管 M4和所 述驱动晶体管 DTFT为 N型薄膜晶体管， 可选地， 所有开关管只起开关的 作用， 也可为 P型晶体管， 导通或关断开关管的信号做相应调整即可。 由 于这里采用的开关晶体管的源极、 漏极是对称的， 所以其源极、 漏极是可 以互换的。 在本发明实施例中， 为区分晶体管除栅极之外的两极， 将其中 一极称为源极， 另一极称为漏极。 若选取源极作为信号输入端、 则漏极作 为信号输出端， 反之亦然。
下面具体说明该像素电路的工作过程。
结合图 2所示的像素电路以及图 3中的时序图，其工作过程分 3个阶 段： 预充阶段、 补偿阶段以及发光阶段。
第一阶段为预充阶段 C, 当扫描信号选通第 n-1行像素单元时，第 n-1 行像素单元对应的第二扫描信号 Vscan(n-l)为高电平， 第二开关晶体管 M2、 第三开关晶体管 M3保持开启， 而第 n行像素单元对应的第一扫描信 号 Vscan ( n )为低电平， 第一开关晶体管 Ml关闭， 第一控制信号 EM为 低电平， 第四开关晶体管 M4也保持关闭。 此时， 第二开关晶体管 M2的 漏极处 A点的电压，以及驱动晶体管 DTFT的栅极处 B点的电压均开始下 降，耦合电容 C2储存的电荷进行释放， 此时耦合电容 C2两端的电压下降 至驱动晶体管 DTFT的阈值电压 Vth, 直至 A点的电压下降至 0, 而 B点 的电压则下降至驱动晶体管 DTFT的阈值电压 Vth ,从而驱动晶体管 DTFT 关闭， 耦合电容 C2两端的电压大小也变化为 A、 B两点的电压差值 Vth。
第二阶段为补偿阶段 D, 当扫描信号选通第 n行像素单元时， 第 n-1 行像素单元对应的第二扫描信号 Vscan(n-l)为低电平， 第二开关晶体管 M2、 第三开关晶体管 M3 关闭， 而第 n行像素单元对应的第一扫描信号 Vscan(n)为高电平， 第一开关晶体管 Ml 开启， 引入数据线上的数据信号 Vdata, 并对存储电容 C1充电以存储该数据信号 Vdata。 随后， 数据信号 Vdata使得 A点电压抬升至 Vdata, 由于耦合电容 C2的作用， 薄膜晶体管 栅极 B点的电压升高变为 Vdata+Vth,驱动薄膜晶体管保持导通临界状态。
第三阶段为发光阶段 E: 第一控制信号 EM接高电平控制第四开关晶 体管 M4开启， 由于电源电压 Vdd远大于数据电压 Vdata, 因此驱动晶体 管 DTFT开启， 电源电压 Vdd通过驱动晶体管 DTFT向发光器件 D1输出 电流驱动有发光器件 D1发光。
此时流过驱动晶体管 DTFT的电流可以用下述公式表达：
I=k(Vgs-Vth)2其中 k=l/2* *Cox*W/L, 为常数 ….. （1 )
驱动晶体管 DTFT的栅源电压 Vgs=Vg-Vs。驱动晶体管 DTFT的栅极 电压 Vg即为 B点电压 Vdata+Vth,源极电压 Vs为此时 C点电压即发光器 件 D1的开启电压 VD1。 因此， 驱动晶体管 DTFT的栅源电压 Vgs为： Vgs=Vdata+Vth-VDi ·· ·· · · ( 2 )
将公式（2 )代入（1 )得出：
I=k(Vgs-Vth)2=k(Vdata+Vth-VDi-Vth)2=k(Vdata-VDi)2 …… （ 3 ) 从公式（3 ) 可以看出， 流过驱动晶体管 DTFT的电流值与其阈值电 压的变化无关， 也就是说， 即使经过长时间的使用， 驱动晶体管 DTFT的 阈值电压发生漂移， 但是流过驱动晶体管 DTFT的电流也不会因此而受到 影响， 也保证了发光器件 D1 的发光质量。 相应地， 由于单个像素电路中 发光器件 D1 的发光质量得到了保证， 本电路可以有效地补偿驱动晶体管 阈值电压的不均匀性， 使得显示装置的画面均匀性提高， 而无需借助外部 补偿电路进行阈值电压补偿， 从而降低了研发及制造成本。 而且该像素的 时序筒单， 容易实现。
优选地， 所述第一开关晶体管、 第二开关晶体管、 第三开关晶体管第 四开关晶体管和所述驱动晶体管为 N型薄膜晶体管。
优选地， 所述发光器件为有机发光二极管， 当然其他发光器件也是可 以的。 实施例 2:
本实施例提供一种上述像素电路的驱动方法， 包括如下步骤： 预充阶段：选通所述第二扫描信号 Vscan(n-l)以及所述电源电压 Vdd, 所述第二开关晶体管 M2和第三开关晶体管 M3开启， 所述耦合电容 C2 储存的电荷进行释放， 直到所述耦合电容 C2的第二端的电压为驱动晶体 管 DTFT的阈值电压；
补偿阶段： 选通所述第一扫描信号 Vscan(n), 所示第一开关晶体管 Ml开启， 关断第二扫描信号 Vscan(n-l), 所述数据信号 Vdata输入所述耦 合电容 C2的第一端，所述耦合电容 C2的第二端的电压升高并开启所述驱 动薄膜晶体管 DTFT;
发光阶段： 选通所述第一控制信号 EM, 所述第四开关晶体管 M4开 启， 所述驱动晶体管 DTFT 继续保持导通状态， 驱动所述发光器件发光 Dl。
该方法的具体实施方式与实施例 1的工作过程相同， 在此不再赘述， 该方法筒单容易实现， 所以适用性更广。 实施例 3:
本实施例提供阵列基板， 包括多条数据线、 多条扫描线， 所述的数据 线与扫描线交叉排列， 在交叉处设有实施例 1中的像素电路。
本实施例具有实施例 1中像素电路中的阈值补偿电路，可以有效的补 偿了驱动晶体管 DTFT阈值电压的不均匀性， 使得本实施例中的阵列基板 性能更加稳定。 实施例 4:
本实施例提供一种显示装置，所述的显示装置中的有机发光显示装置 阵列基板如实施例 3中所述， 此处不详细描述。
当然本实施例中该显示装置可以包括： OLED面板、手机、平板电脑、 电视机、 显示器、 笔记本电脑、 数码相框、 导航仪等任何具有显示功能的 产品或部件。
由于具有上述的显示装置的阵列基板，故本实施例的显示装置的画面 均匀性明显提高。 可以理解的是， 以上实施方式仅仅是为了说明本发明的原理而采用的 示例性实施方式， 然而本发明并不局限于此。 对于本领域内的普通技术人 员而言， 在不脱离本发明的精神和实质的情况下， 可以做出各种变型和改 进， 这些变型和改进也视为本发明的保护范围。

Claims

权 利 要 求 书
1、 一种像素电路， 包括： 第一开关晶体管、 存储电容、 驱动晶体管、 发光器件以及阈值补偿电路， 其中，
所述阈值补偿电路包括： 第二开关晶体管、 第三开关晶体管、 第四开关 晶体管以及耦合电容；
所述第一开关晶体管的栅极接第一扫描信号，所述第一开关晶体管的第 二极接数据信号输入端， 所述第一开关晶体管的第三极接存储电容第一端、 耦合电容的第一端以及第二开关晶体管的第二极；
所述存储电容的第二端接电源电压同时接所述驱动晶体管的第二极； 所述第二开关晶体管的栅极接第二扫描信号同时接所述第三开关晶体 管的栅极， 所述第二开关晶体管的第三极接电源负极端；
所述第三开关晶体管的第二极接所述驱动晶体管的栅极，所述第三开关 晶体管的第三极接所述驱动晶体管的第三极同时接所述第四开关晶体管的 第二极；
所述第四开关晶体管的栅极接第一控制信号，所述第四开关晶体管的第 三极接所述发光器件；
所述耦合电容的第二端与所述驱动晶体管的栅极相连。
2、 根据权利要求 1所述的像素电路， 其中， 所述第一开关晶体管、 第 二开关晶体管、第三开关晶体管、第四开关晶体管和所述驱动晶体管为 N型 薄膜晶体管， 所述第二极为漏极， 第三极为源极。
3、 根据权利要求 1所述的像素电路， 其中， 所述第一开关晶体管、 第 二开关晶体管、 第三开关晶体管、 第四开关晶体管和所述驱动晶体管为 P型 薄膜晶体管， 所述第二极为源极， 第三极为漏极。
4、 根据权利要求 1-3任一项所述的像素电路， 其中， 所述发光器件为 有机发光二极管。
5、 一种用于权利要求 1至 4中任一项所述的像素电路的驱动方法， 包 括以下步骤：
预充阶段： 选通所述第二扫描信号以及所述电源电压，使得所述第二开 关晶体管和第三开关晶体管开启，所述耦合电容储存的电荷通过第二开关晶 体管进行释放；
补偿阶段： 选通所述第一扫描信号， 使得所述第一开关晶体管开启， 关 断第二扫描信号，使得数据信号输入所述耦合电容的第一端和存储电容的第 一端， 所述耦合电容的第二端的电压升高并开启所述驱动薄膜晶体管； 发光阶段： 选通所述第一控制信号， 使得所述第四开关晶体管开启， 所 述存储电容保持所述耦合电容第一端的电压，所述驱动晶体管继续保持导通 状态， 驱动所述发光器件发光。
6、 一种阵列基板， 包括如权利要求 1至 4中任一项所述的像素电路。
7、 一种显示装置， 包括如权利要求 6所述的阵列基板。
PCT/CN2013/075160 2013-03-20 2013-05-04 像素电路及其驱动方法、阵列基板、显示装置 WO2014146339A1 (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US14/344,666 US20150145853A1 (en) 2013-03-20 2013-05-04 Pixel circuit, method for driving the same, array substrate, display device

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201310090818.2 2013-03-20
CN2013100908182A CN103208254A (zh) 2013-03-20 2013-03-20 像素电路及其驱动方法、阵列基板、显示装置

Publications (1)

Publication Number Publication Date
WO2014146339A1 true WO2014146339A1 (zh) 2014-09-25

Family

ID=48755464

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2013/075160 WO2014146339A1 (zh) 2013-03-20 2013-05-04 像素电路及其驱动方法、阵列基板、显示装置

Country Status (2)

Country Link
CN (1) CN103208254A (zh)
WO (1) WO2014146339A1 (zh)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103531151B (zh) 2013-11-04 2016-03-02 京东方科技集团股份有限公司 Oled像素电路及驱动方法、显示装置
CN103956141B (zh) * 2014-05-15 2016-05-11 武汉天马微电子有限公司 像素驱动电路及其驱动方法、像素阵列基板以及显示面板
TWI652661B (zh) * 2018-06-07 2019-03-01 友達光電股份有限公司 畫素電路
CN108847183B (zh) * 2018-07-04 2020-06-16 深圳市华星光电半导体显示技术有限公司 一种像素驱动电路及显示面板
CN111243504B (zh) * 2018-11-29 2021-04-23 成都辰显光电有限公司 一种像素驱动电路及显示装置
CN109584803B (zh) * 2019-01-04 2021-01-26 京东方科技集团股份有限公司 像素驱动电路及其驱动方法、显示面板
CN110223636B (zh) 2019-06-17 2021-01-15 京东方科技集团股份有限公司 像素驱动电路及其驱动方法、显示装置
CN110444167A (zh) * 2019-06-28 2019-11-12 福建华佳彩有限公司 一种amoled补偿电路
CN111354308A (zh) * 2020-04-09 2020-06-30 上海天马有机发光显示技术有限公司 一种像素驱动电路、有机发光显示面板及显示装置

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030098657A1 (en) * 2001-11-28 2003-05-29 International Business Machines Corporation Pixel driving circuit system and method for electroluminescent display
JP2006285269A (ja) * 2006-05-29 2006-10-19 Sony Corp アクティブマトリクス型表示装置の駆動方法
KR20060134405A (ko) * 2005-06-22 2006-12-28 엘지.필립스 엘시디 주식회사 유기전계발광소자 및 유기전계발광 표시장치
CN1917016A (zh) * 2005-08-17 2007-02-21 三星Sdi株式会社 有机发光显示设备及其发射控制驱动器和逻辑或电路
CN101401145A (zh) * 2006-06-15 2009-04-01 夏普株式会社 电流驱动型显示装置和像素电路

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100370286B1 (ko) * 2000-12-29 2003-01-29 삼성에스디아이 주식회사 전압구동 유기발광소자의 픽셀회로
KR100578813B1 (ko) * 2004-06-29 2006-05-11 삼성에스디아이 주식회사 발광 표시 장치 및 그 구동 방법
KR100684714B1 (ko) * 2004-09-15 2007-02-20 삼성에스디아이 주식회사 발광 표시 장치 및 그 구동 방법
KR100739334B1 (ko) * 2006-08-08 2007-07-12 삼성에스디아이 주식회사 화소와 이를 이용한 유기전계발광 표시장치 및 그의구동방법
KR100897172B1 (ko) * 2007-10-25 2009-05-14 삼성모바일디스플레이주식회사 화소 및 그를 이용한 유기전계발광표시장치
CN102290027B (zh) * 2010-06-21 2013-10-30 北京大学深圳研究生院 一种像素电路及显示设备
CN102542977B (zh) * 2010-12-27 2015-03-04 上海天马微电子有限公司 有机发光二极管像素结构、显示面板及电子显示装置
CN102820006B (zh) * 2012-08-02 2015-10-14 京东方科技集团股份有限公司 一种补偿阈值电压漂移的像素电路和薄膜晶体管背板
CN102930820B (zh) * 2012-10-23 2015-04-29 京东方科技集团股份有限公司 像素驱动电路、显示装置及像素驱动方法
CN203165421U (zh) * 2013-03-20 2013-08-28 合肥京东方光电科技有限公司 像素电路、阵列基板及显示装置

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030098657A1 (en) * 2001-11-28 2003-05-29 International Business Machines Corporation Pixel driving circuit system and method for electroluminescent display
KR20060134405A (ko) * 2005-06-22 2006-12-28 엘지.필립스 엘시디 주식회사 유기전계발광소자 및 유기전계발광 표시장치
CN1917016A (zh) * 2005-08-17 2007-02-21 三星Sdi株式会社 有机发光显示设备及其发射控制驱动器和逻辑或电路
JP2006285269A (ja) * 2006-05-29 2006-10-19 Sony Corp アクティブマトリクス型表示装置の駆動方法
CN101401145A (zh) * 2006-06-15 2009-04-01 夏普株式会社 电流驱动型显示装置和像素电路

Also Published As

Publication number Publication date
CN103208254A (zh) 2013-07-17

Similar Documents

Publication Publication Date Title
CN105931599B (zh) 像素驱动电路及其驱动方法、显示面板、显示装置
WO2014146339A1 (zh) 像素电路及其驱动方法、阵列基板、显示装置
CN104318897B (zh) 一种像素电路、有机电致发光显示面板及显示装置
WO2015169006A1 (zh) 一种像素驱动电路及其驱动方法和显示装置
WO2015085699A1 (zh) Oled像素电路及驱动方法、显示装置
WO2017031909A1 (zh) 像素电路及其驱动方法、阵列基板、显示面板及显示装置
WO2016188012A1 (zh) 像素电路、其驱动方法及显示装置
WO2018054350A1 (zh) 像素电路及其驱动方法、阵列基板以及显示装置
WO2014176834A1 (zh) 像素电路及其驱动方法、显示装置
WO2016101504A1 (zh) 一种像素电路、有机电致发光显示面板及显示装置
WO2016150372A1 (zh) 像素电路及其驱动方法和一种显示装置
WO2016011714A1 (zh) 像素电路、像素电路的驱动方法和显示装置
WO2016155161A1 (zh) Oeld像素电路、显示装置及控制方法
WO2016011711A1 (zh) 像素电路、像素电路的驱动方法和显示装置
WO2014153806A1 (zh) 像素电路及其驱动方法、显示装置
WO2015180419A1 (zh) 像素电路及其驱动方法和一种显示装置
WO2019109673A1 (zh) 像素电路及其驱动方法、显示面板和显示设备
WO2014127555A1 (zh) 像素单元驱动电路、驱动方法、像素单元及显示装置
WO2017024754A1 (zh) 像素电路及其驱动方法、阵列基板、显示装置
WO2015188533A1 (zh) 像素驱动电路、驱动方法、阵列基板及显示装置
WO2015188532A1 (zh) 像素驱动电路、驱动方法、阵列基板及显示装置
WO2015062298A1 (zh) Oled像素电路及其驱动方法和显示装置
WO2015188471A1 (zh) 像素电路、显示装置和像素电路的驱动方法
WO2016045256A1 (zh) 像素电路及其发光器件驱动方法和有机电致发光显示面板
WO2015032141A1 (zh) 像素电路及显示器

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 14344666

Country of ref document: US

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

Ref document number: 13879107

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: 13879107

Country of ref document: EP

Kind code of ref document: A1