TWI556212B - Oled pixel compensation circuit and oled pixel driving method - Google Patents

Description

OLED pixel compensation circuit and OLED pixel driving method

The present invention relates to a pixel compensation circuit and a pixel driving method, and more particularly to a pixel compensation circuit and a pixel driving method for an OLED display device.

OLED has the characteristics of power saving, suitable for large size and full color, but it also extends many problems in the application process, such as the material properties of thin film transistor (TFT) used for OLED as a switch or driving element. Variations and different degrees of aging of the material can cause unevenness in the display of the panel. In addition, after the OLED is used for a long time, the OLED device will be deteriorated, and the aging of the device may cause a problem that the threshold voltage rises and the luminous efficiency decreases. In order to solve the above problems, those skilled in the art have proposed various pixel compensation circuits for compensating for OLED and drive element threshold voltage variations.

However, the application of these pixel compensation circuits introduces a new problem: these pixel compensation circuits mostly use nTnC (T stands for thin film transistor, C stands for capacitance, and n is an integer representing the number of thin film transistors or the number of capacitors). Although the pixel compensation circuit using these structures can effectively compensate for variations in the threshold voltage of the OLED and the driving transistor, the pixel compensation circuit occupies a large amount of space of the pixel region (pixel). As the size of the technology development pixel becomes smaller and smaller, the compensation circuit of the huge nTnC located inside the pixel area will The aperture ratio of the pixels of the OLED panel is seriously affected and the wiring space in the OLED panel is compressed.

In view of this, the inventors have conceived and further studied, and finally invented an OLED pixel compensation circuit and an OLED pixel driving method.

An object of the present invention is to provide an OLED pixel compensation circuit and an OLED pixel driving method, which can compensate for the problem that the threshold voltage _{Vth of} different driving transistors is inconsistent, resulting in uneven image of the OLED display; further OLED pixel compensation circuit of the present invention A part of the components is disposed outside the pixel region, which can significantly increase the aperture ratio of the pixel region and reduce the difficulty of wiring inside the OLED panel.

In order to solve the above problems, the present invention provides an OLED pixel compensation circuit including: a load driving module and a data voltage storage module located inside a pixel area, and a threshold voltage measuring module located outside the pixel area, wherein: the valve The value voltage measuring module is configured to measure and store the threshold voltage of the load driving module under the control of the second scanning end; the data voltage storage module is configured to receive and store the output of the data signal end under the control of the first scanning end a data voltage, under the control of the illumination control end, the threshold voltage stored in the threshold voltage measurement module and the data voltage stored in the data voltage storage module are superimposed in series to form a driving voltage output to the load driving module; the load driving The module is controlled by the illumination control end to convert the driving voltage received from the data voltage storage module into a driving current for driving the organic light emitting diode.

A further improvement of the OLED pixel compensation circuit of the present invention is that the load driving module comprises a driving transistor, a second transistor and a third transistor, wherein: the gate of the driving transistor is connected to the first node, and the source thereof Connected to the third node; the source and the drain of the second transistor are respectively connected to the gate and the drain of the driving transistor, and the gate thereof is connected to the second scanning end; the gate connection of the third transistor In the light-emitting control end, the drain is connected to the first power source, the source thereof is connected to the third node; the drain of the driving transistor is connected to the anode of the organic light-emitting diode, and the cathode of the organic light-emitting diode is connected to a second power source; the driving transistor is configured to convert the driving voltage into the driving current, and the threshold voltage of the load driving module is a threshold voltage of the driving transistor.

A further improvement of the OLED pixel compensation circuit of the present invention is that the data voltage storage module includes a first transistor and a first capacitor; one end of the first capacitor is connected to the first node, and the other end is connected to the fourth node; The source of the first transistor is connected to the first node, the drain of the first transistor is connected to the data signal end, and the gate thereof is connected to the first scan end; the data voltage is stored in the first capacitor.

A further improvement of the OLED pixel compensation circuit of the present invention is that the threshold voltage measurement module includes a second capacitor, a fourth transistor, a fifth transistor, a sixth transistor, and a seventh transistor; the fourth transistor a gate is connected to the second scanning end, a source is connected to the third node, and a drain is connected to the fifth node; a gate of the fifth transistor is connected to the light emitting control end, and a source thereof is connected to The fourth node has a drain connected to the second power source, and a second capacitor is connected across the fourth node and the fifth node; a gate of the sixth transistor is connected to the light emitting control end, and a source thereof Connected to the fifth node, the drain of which is connected to the reference power source; The gate of the seventh transistor is connected to the third scan end, the drain of the seventh transistor is connected to the third power source, and the source thereof is connected to the fifth node; the second capacitor is used for storing the threshold voltage.

A further improvement of the OLED pixel compensation circuit of the present invention is that the first transistor, the second transistor and the third transistor, the fourth transistor sixth transistor, and the seventh transistor are N-channel transistors, and the driving The transistor and the fifth transistor are P-channel transistors.

A further improvement of the OLED pixel compensation circuit of the present invention is that the difference between the voltage of the third power source output and the second power source output voltage is greater than the threshold voltage of the driving transistor and the valve of the organic light emitting diode to be driven The sum of the value voltages.

A further improvement of the OLED pixel compensation circuit of the present invention is that the first power source outputs a positive voltage; the second power source is grounded; the third power source outputs a voltage greater than the voltage of the second power source and less than the voltage of the first power source.

The invention also provides an OLED pixel driving method suitable for the above OLED pixel compensation circuit, which comprises the following steps: a first step, a threshold voltage compensation process: the threshold measurement module measures and stores the load under the control of the second scanning end The threshold voltage of the driving module; the second step, the data voltage writing process: the data storage module receives and stores the data voltage of the data signal end under the control of the first scanning end; the third step, the light emitting display process: at the light emitting control end Under control, the threshold voltage stored by the threshold voltage measuring module and the data voltage stored by the data voltage storage module are connected in series to the load driving module to form a driving voltage, and the load driving module converts the driving voltage into a driving The driving current of the organic light emitting diode.

The invention also provides an OLED pixel driving method suitable for the above OLED pixel compensation circuit, which comprises the following steps: Step A, a re-determining process of the threshold voltage measuring module: the fifth transistor will be the fourth node under the control of the lighting control end Connected to the second power source, the threshold voltage measuring module charges the second capacitor using the third power source under the control of the third scanning end; step B, the threshold voltage measuring process: the second scanning end configures the driving transistor to The diode is connected, and the third node and the fifth node are connected; the second capacitor is discharged until the driving transistor and the organic light emitting diode are turned off; step C, the data voltage writing process: the first scanning end controls the data voltage The storage module obtains the data voltage from the data signal end, and the data voltage is stored in the first capacitor; in step D, the illumination display process: the illumination control terminal controls the fifth transistor to turn off, causing the fourth node to float, thereby causing the data to be The first capacitor of the voltage storage module, the second capacitor of the threshold voltage measuring module, and the voltage of the reference power source are connected in series to the first node to form a driving power , Under the control of the driving transistor control terminal of the light emission driving voltage of the first node into the drive current driving the OLED.

A further improvement of the OLED pixel driving method of the OLED pixel compensation circuit of the present invention is that the current flowing through the organic light emitting diode when the OLED pixel compensation circuit is in the compensation process is smaller than the minimum light emitting current of the organic light emitting diode.

In the technical solution of the present invention, a part of components in the OLED pixel driving circuit are disposed outside the pixel region, which can reduce the area occupied by the pixel compensation circuit inside the pixel region, and can effectively increase the aperture ratio of the pixel. The number of originals inside the pixel area is reduced, which can reduce the difficulty of the OLED panel in the layout process, and prevent the use of the OLED panel. The signal voltage caused by the thin signal line drops. Moreover, the OLED pixel driving circuit of the present invention can compensate for the problem of uneven brightness of the OLED panel caused by the threshold voltage variation, and the OLED pixel driving circuit of the present invention can also compensate the organic light emitting diode device. The problem of decreased luminous efficiency caused by aging.

The present invention has been described in connection with the preferred embodiments of the present invention in accordance with the accompanying drawings.

〔this invention〕

10‧‧‧Load Drive Module

20‧‧‧ threshold voltage measurement module

30‧‧‧Data Voltage Storage Module

C ₁ ‧‧‧first capacitor

C _out ‧‧‧second capacitor

D _L ‧‧‧data signal end

S _n ‧‧‧first scanning end

S _n-1 ‧‧‧second scanning end

S _n-2 ‧‧‧ third scanning end

S ₂ ‧‧‧Lighting control terminal

T ₁ ‧‧‧first transistor

T ₂ ‧‧‧second transistor

T ₃ ‧‧‧ third transistor

T ₄ ‧‧‧fourth transistor

T ₅ ‧‧‧ fifth transistor

T ₆ ‧‧‧ sixth transistor

T ₇ ‧‧‧ seventh transistor

T ₈ ‧‧‧ drive transistor

U _ed ‧‧‧ voltage at both ends

V _DDH ‧‧‧First power supply

V _SS ‧‧‧second power supply

V _DDL ‧‧‧third power supply

V _r ‧‧‧reference power supply

V _th ‧‧‧ threshold voltage

V _{th_OLED} ‧‧‧ threshold voltage of organic light-emitting diode OLED

A‧‧‧first node

B‧‧‧second node

C‧‧‧third node

D‧‧‧fourth node

E‧‧‧ fifth node

1 is a circuit diagram of an OLED pixel compensation circuit of the present invention; FIG. 2 is a timing diagram of a driving signal of a pixel compensation circuit in the OLED pixel driving method of the present invention; FIG. 3 is the first OLED pixel compensation circuit in the OLED pixel driving method of the present invention; The circuit state diagram of the capacitor charging process; FIG. 4 is a circuit state diagram of the OLED pixel compensation circuit in the OLED pixel driving method in the compensation process; FIG. 5 is the OLED pixel compensation circuit in the OLED pixel driving method of the present invention. Circuit state diagram during the process; FIG. 6 is a circuit state diagram of the OLED pixel compensation circuit in the OLED pixel driving method in the process of illuminating display.

In order to enable your review committee to have a better understanding and understanding of the purpose, features and effects of the present invention, please refer to the following [detailed description of the drawings] as follows: Comparison of the OLED pixel compensation circuit and the OLED pixel driving method of the present invention For example, as shown in FIG. 1 , in the embodiment, the OLED pixel compensation circuit includes: a load driving module 10 , a threshold voltage measuring module 20 , and a data voltage storage module 30 , wherein: the threshold voltage measuring module 20 is connected to the second scanning end S _n-1 , the illumination control terminal S ₂ , the third scanning end S _n-2 , the third power source V _DDL and the load driving module 10 , and the threshold voltage measuring module 20 is used in the The threshold voltage of the load driving module 10 is measured and stored under the control of the second scanning end Sn _-1 ; the data voltage storage module 30 and the first scanning end S _n , the data signal terminal D _L , and the threshold voltage measuring module 20 blocks And the load driving module 10 is connected. The data voltage storage module 30 is controlled by the first scanning end S _{n to} receive and store the data voltage outputted by the data signal terminal D _L ; the load driving module 10 is connected to the light emitting control terminal S ₂ , and the load driving module 10 is controlled by the light emitting The control terminal S ₂ converts the voltage signal received from the data voltage storage module 30 into a driving current for driving the organic light diode. In the above module, the load driving module 10 and the data voltage storage module bit 30 are inside the pixel area. The threshold voltage measurement module 30 is located outside the pixel area.

As shown in FIG. 1 , the load driving module 10 includes a driving transistor T ₈ , a second transistor T _{2 ,} and a third transistor T ₃ ; wherein: the gate of the driving transistor T ₈ is connected to the first node a, The source is connected to the third node c; the source and the drain of the second transistor T ₂ are respectively connected to the gate and the drain of the driving transistor T ₈ , and the gate thereof is connected to the second scanning end Sn _-1 . when the second end of the scanning output signals S _{n 1-valid,} the driving transistor _{T. 8} is configured to diode connection; third transistor T ₃ is connected to a brake light emission control terminal S _2, which is connected to the drain a first power source V _DDH whose source is connected to the third node c; when the output signal of the light-emitting control terminal S ₂ is valid, the driving transistor T ₈ converts the voltage of the first node a into a driving for driving the organic light-emitting diode Current. The source of the driving transistor T ₈ is connected to the anode of the organic light emitting diode, and the cathode of the organic light emitting diode is connected to the second power source. The driving transistor T _{8 is} used to convert the driving voltage into a driving current of the organic light emitting diode.

As shown in Figure 1, the data voltage storage module 30 includes a first transistor T ₁ and a first capacitor C ₁ ; one end of the first capacitor C ₁ is connected to the first node a, the other end is connected to the fourth node d; The first transistor T _{1 has} a source connected to the first node a, a drain connected to the data signal terminal D _L , and a gate connected to the first scanning terminal S _n ; and a data voltage received from the data signal terminal D _L Stored in the first capacitor C ₁ .

As shown in FIG. 1, the threshold voltage measuring module 20 includes a second capacitor C _out , a fourth transistor T ₄ , a fifth transistor T ₅ , a sixth transistor T _{6 ,} and a seventh transistor T ₇ ; The gate of the transistor T ₄ is connected to the second scanning end Sn _-1 , the source thereof is connected to the third node c, the drain thereof is connected to the fifth node e; the gate of the fifth transistor T ₅ is connected to the light emitting The control terminal S _n has a source connected to the fourth node d, a drain connected to the second power source V _SS , and a second capacitor C _out connected between the fourth node d and the fifth node e; The gate of the crystal T ₆ is connected to the light-emitting control terminal S ₂ , the source thereof is connected to the fifth node e, the drain thereof is connected to the reference power source V _r , and the gate of the seventh transistor T ₇ is connected to the third scan terminal S _N-2 , the drain is connected to the third power source V _DDL , the source thereof is connected to the fifth node e, and the second capacitor C _{out is} used for storing the threshold voltage observed from the load driving module 10.

1, a first transistor T _1, a second transistor T _2, a third transistor T _3, the first capacitor C _1, and the driving transistor T ₈ is located inside the pixel region. The fourth transistor T ₄ , the fifth transistor T ₅ , the sixth transistor T ₆ , the seventh transistor T _{7 ,} and the second capacitor C _{out are} located outside the pixel region. Setting a part of the components constituting the pixel compensation circuit outside the pixel area can reduce the area occupied by the pixel compensation circuit inside the pixel area, and can effectively increase the aperture ratio of the pixel. The reduction in the number of originals inside the pixel area can reduce the difficulty of the OLED panel in the layout process. Therefore, a wider signal line can be used in the wiring process to prevent a decrease in signal voltage due to the use of a thin signal line.

As shown in FIG. 1, the first power source V _DDH is a positive power source, and the second power source V _{SS is} grounded. The voltage values of the third power source V _DDL and the reference power source V _r are given values, and the voltage of the given value smaller than the first power source V _DDH is greater than the voltage of the second power source V _SS . And a third power supply voltage value of V _DDL driving transistor T is larger than the threshold voltage V _th OLED and OLED ₈ is the sum of the threshold voltage _V th_OLED.

2, the OLED pixel driving method according to the present embodiment through a first embodiment of the scanning end S _n, the second scan end S _{n-1, n-2} and the light emitting end of the third control terminal S S ₂ scan control OLED pixel compensation circuit The transistor in the middle is turned on or off according to a predetermined timing to achieve the purpose of controlling the illumination of the OLED. The method of the present embodiment comprises the following four steps: Step A, the threshold voltage of the charging process measurement module 20 is: t ₁ corresponds to the state in FIG. 2, when the fifth transistor T ₅ is turned on, the fourth node d is connected to the lead The second power source V _SS , on the other hand, the threshold voltage measuring module 20 connects the third power source V _DDL to the fifth node e, and at this time, the third power source V _DDL charges the second capacitor C _out ; Step B, the threshold voltage Compensation process: corresponding to the t ₂ state in FIG. 2, at this time, the driving transistor T ₈ is in a diode connection, the load driving module 10 connects the third node c to the fifth node e, and the second capacitor C _{out is} discharged until driving. The transistor T ₈ or the organic light emitting diode is turned off; the step C, the data voltage writing process: corresponding to the t ₃ state in FIG. 2, the data signal terminal D _L writes the data voltage to the data voltage storage module 30, and the data voltage is stored. In the first capacitor C ₁ ; Step D, the light-emitting display process: corresponding to the state of t _{4 in} FIG. 2, the signal of the light-emitting control terminal S ₂ is effective to cause the voltage of the fourth node d to float, and the first capacitor C ₁ , two capacitors C _out, and a reference power source voltage V _r is superimposed to the driving transistor T gate electrode ₈ At this time, the driving transistor in the saturation region, the driving transistor T flows through the current source ₈ and the gate electrode of the driving OLED to emit light.

As shown in FIG. 2 and FIG. 3, when the OLED pixel compensation circuit is in the charging process of the threshold voltage measuring module 20, the first scanning end S _n , the second scanning end Sn _-1 and the illumination control end S ₂ are both Low level, the third scanning end Sn _-2 is at a high level. At this time, the first scan by a first control terminal S _n transistor T is turned _{off. 1;} a second transistor second terminal S _n-1 scan controlled by T _2, the fourth transistor T is turned _{off. 4;} the third scan by The seventh transistor T ₇ controlled by the terminal S _{n-2 is} turned on; the fifth transistor T ₅ controlled by the light-emitting control terminal S _{2 is} turned on, and the sixth transistor T ₆ and the third transistor T _{3 are} turned off.

When the OLED pixel compensation circuit is in the charging process of the threshold voltage measuring module 20, since the fifth transistor T ₅ and the seventh transistor T _{7 are} turned on from the third power source V _DDL , the fifth node e , and the fourth node d A path is formed between the second power sources V _SS . The second capacitor C _out between the fifth node e and the fourth node d in the above path is charged, and the fifth transistor T ₅ and the seventh transistor T _{7 are} turned on because the other transistors are all in the off state. When the voltage drop is negligible, the voltage across the second capacitor C _{out is} completed as V _DDL -V _SS .

As shown in FIG. 2 and FIG. 4, when the OLED pixel compensation circuit is in the threshold voltage compensation process, the first scanning end S _n , the third scanning end S _n-2 and the illumination control terminal S ₂ are both low level, second The scanning terminal Sn _-1 is at a high level. At this time, the first scan by a first control terminal S _n transistor T is turned _{off. 1;} a second transistor second terminal S _n-1 scan controlled by T _{2, T. 4} of the fourth transistor is turned on; SUBJECTED third scan The seventh transistor T ₇ controlled by S _{n-2 is} turned off; the fifth transistor T ₅ controlled by the light-emission control terminal S _{2 is} turned on, and the sixth transistor T ₆ and the third transistor T _{3 are} turned off.

When the OLED pixel compensation circuit is in the threshold voltage compensation process, since the first transistor T _{1 is} turned off, the second transistor T _{2 is} turned on, at which time the voltages of the first node a and the second node b are equal and the transistor T is driven. _{8 is} in the diode connection, the so-called diode connection is to drive the transistor T ₈ of the gate and the drain is shorted. At this time, the second transistor T ₂ , the fourth transistor T _{4 ,} and the fifth transistor T _{5 are} turned on by other transistors, so that the second power source V _SS , the fourth node d, the fifth node e, and the third node are c. A loop is formed between the second node b and the second power source V _SS . Since the second capacitor C _out is charged with a voltage of V _DDL -V _SS during the second capacitor charging process, the second capacitor C _out is discharged in the above loop at this time. Conducting condition of the loop is: the potential difference between the third node and the second node b c Ucb difference is greater than the threshold voltage of the driving transistor T V _{th 8} and the potential difference between the node b and the second power is greater than V _SS The threshold voltage V _{th —} OLED of the organic light emitting diode OLED. The voltage of both ends of the second capacitor C _out decreases along the above-mentioned loop discharge process until the voltage U _ed at both ends thereof cannot maintain the driving transistor T ₈ and the organic light emitting diode OLED to be turned on. In summary, when the second capacitor C _{out is} discharged, the voltage across it is U _ed =V _th +V _{th_OLED} . In addition, in order to prevent the voltage value of the organic light-emitting diode OLED light-emitting V _DDL from being excessive during the compensation process, the OLED emits light during the compensation process.

As shown in FIG. 2 and FIG. 5, when the OLED pixel compensation circuit is in the data voltage writing process, the first scanning end S _n , the second scanning end Sn _-1 and the illumination control terminal S ₂ are both low level, and the third The scanning terminal Sn _-2 is at a high level. At this time, the first scan by a first control terminal S _n transistor T is turned _{on. 1;} a second transistor second terminal S _n-1 scan controlled by T _2, the fourth transistor T is turned _{off. 4;} SUBJECTED third scan The seventh transistor T ₇ controlled by S _{n-2 is} turned off; the fifth transistor T ₅ controlled by the light-emission control terminal S _{2 is} turned on, and the sixth transistor T ₆ and the third transistor T _{3 are} turned off.

When the OLED pixel compensation circuit is in the data voltage writing process, since the first transistor T ₁ and the fifth transistor T _{5 are} turned on and the other transistors are turned off, at the data signal terminal D _L , the first node a, the fourth A path is formed between the node b and the second power source V _SS . Connected in series with the passage of the first capacitor C ₁ is charged, the voltage across the first capacitor C ₁ to charge completion Uab voltage VDL electrical data signal and a second power supply terminal V _SS potential difference V _DL -V _SS. During the data voltage writing process, since the fourth transistor T ₄ , the sixth transistor T _{6 ,} and the seventh transistor T _{7 are} turned off, the second capacitor C _{out is} in a floating state during the data voltage writing process. The voltage across the second capacitor _Cout does not change.

As shown in FIG. 2 and FIG. 6, when the OLED pixel compensation circuit is in the illuminating display process, the first scanning end S _n , the second scanning end Sn _-1 and both are low level, and the third scanning end Sn _-2 illuminates. The control terminal S ₂ is at a high level. At this time, the first scan by a first control terminal S _n transistor T is turned _{off. 1;} a second transistor second terminal S _n-1 scan controlled by T _2, the fourth transistor T is turned _{off. 4;} the third scan by The seventh transistor T ₇ controlled by the terminal S _{n-2 is} turned off; the fifth transistor T ₅ controlled by the light-emission control terminal S _{2 is} turned off, and the sixth transistor T ₆ and the third transistor T _{3 are} turned on.

When the OLED pixel compensation circuit is in the illuminating display process, since the sixth transistor T ₆ and the third transistor T ₃ turn on other transistors to turn off, two paths are formed in the OLED pixel compensation circuit: the path 1 is from V-DDH, The third node c, the second node b to the second power source V _SS ; the path 2 is from the reference power source V _r , the fifth node e, and the fourth node d to the first node a. For driving transistor T path 1, if the driving transistor T ₈ of the gate voltage V _a and the first supply voltage V _DDH difference is greater than the threshold voltage V _th of the driving transistor T _{8 8} turned on. Since the organic light emitting diode OLED and the driving transistor T _{8 are} connected in series, the current flowing through the organic light emitting diode OLED is equal to flowing through the first pole (drain) and the second pole (source) of the driving transistor T ₈ . The current between. In summary, when the driving transistor T _{8 is} turned on, the current flowing through the organic light emitting diode OLED and the voltage V _{a of the} first node _a satisfy the following relationship: I _OLED = 0.5 μ _p C _OX (W/L) (V) _DDH -V _a -V _th ) ² (Formula 1.1)

In addition, the first capacitor C ₁ , the second capacitor C _{out ,} and the reference power source connected in series with the path 2 are superimposed on the first node a, thereby obtaining the voltage V _a at the first node _a : V _a =V _r -V _th -V _{th_OLED} +V _DL (Equation 1.2)

Bringing Equation 1.2 into Equation 1.1 gives: I _OLED = 0.5μ _p C _OX (W/L) (V _DDH -V _r +V _{th_OLED} -V _DL ) ² (Equation 1.3)

It can be seen from Equation 1.3 that the current I _OLED flowing through the organic light emitting diode _OLED and V _DDH , V _r , V _{th — OLED} and V _{DL are} independent of the threshold voltage V _{th of the} driving transistor T ₈ , and the organic light emitting diode OLED is related. The brightness is determined by the current I _OLED flowing through the organic light emitting diode OLED, so that the error of the threshold voltage V _th of the driving transistor T ₈ can be eliminated after the compensation of the OLED pixel compensation circuit of the present invention. Impact. In addition, the aging of the organic light-emitting diode OLED may occur after a long period of use, and the aging of the device may cause problems such as an increase in the threshold voltage V _{th — OLED and} a decrease in luminous efficiency. In the embodiment, the operational expression of the I _OLED further includes V _{th — OLED} . As a result, the rise of V _{th — OLED} can cause the I _{OLED to} grow, and the increased current can be used to compensate for the reduced luminous efficiency, thereby solving the problem of reduced luminous efficiency caused by device aging.

The present invention has been described in detail above with reference to the embodiments of the drawings, and various modifications of the invention can be made by those skilled in the art in light of the above description. Thus, the embodiment The details of the invention are not to be construed as limiting the scope of the invention as defined by the appended claims.

From the above, it is known that the present invention truly conforms to "industrial availability," "novelty," and "progressiveness", and submits an invention patent application in accordance with the law, praying for review and early granting of a patent, and it is truly sensible.

10‧‧‧Load Drive Module

20‧‧‧ threshold voltage measurement module

30‧‧‧Data Voltage Storage Module

C ₁ ‧‧‧first capacitor

C _out ‧‧‧second capacitor

S _n ‧‧‧first scanning end

S _n-1 ‧‧‧second scanning end

S _n-2 ‧‧‧ third scanning end

S ₂ ‧‧‧Lighting control terminal

T ₁ ‧‧‧first transistor

T ₂ ‧‧‧second transistor

T ₃ ‧‧‧ third transistor

T ₄ ‧‧‧fourth transistor

T ₅ ‧‧‧ fifth transistor

T ₆ ‧‧‧ sixth transistor

T ₇ ‧‧‧ seventh transistor

T ₈ ‧‧‧ drive transistor

V _DDH ‧‧‧First power supply

V _SS ‧‧‧second power supply

V _DDL ‧‧‧third power supply

V _r ‧‧‧reference power supply

A‧‧‧first node

B‧‧‧second node

C‧‧‧third node

D‧‧‧fourth node

E‧‧‧ fifth node

Claims (8)

An OLED pixel compensation circuit includes: a load driving module and a data voltage storage module located inside a pixel area, and a threshold voltage measuring module located outside the pixel area, wherein: the threshold voltage measuring module is used in the first Measuring and storing the threshold voltage of the load driving module under the control of the scanning end; the data voltage storage module is configured to receive and store the data voltage outputted by the data signal end under the control of the first scanning end; under the control of the illumination control end The threshold voltage stored in the threshold voltage measuring module and the data voltage stored in the data voltage storage module are superimposed in series to form a driving voltage output to the load driving module; the load driving module is controlled by the light emitting control end And driving the driving voltage received from the data voltage storage module into a driving current for driving the organic light emitting diode; the load driving module includes a driving transistor, a second transistor, and a third transistor, wherein the driving transistor a gate is connected to the first node, and a source is connected to the third node; a source and a drain of the second transistor are respectively connected to the drive The gate and the drain of the electromagnet have a gate connected to the second scan end; the gate of the third transistor is connected to the light-emitting control end, the drain is connected to the first power source, and the source is connected to the third a node; a drain of the driving transistor is connected to an anode of the organic light emitting diode, a cathode of the organic light emitting diode is connected to a second power source; and the driving transistor is configured to convert the driving voltage into the driving current, the load The threshold voltage of the drive module is the threshold voltage of the drive transistor. The OLED pixel compensation circuit of claim 1, wherein the data voltage storage module comprises a first transistor and a first capacitor; the first capacitor One end is connected to the first node, and the other end is connected to the fourth node; the source of the first transistor is connected to the first node, the drain is connected to the data signal end, and the gate is connected to the first scan end The data voltage is stored in the first capacitor. The OLED pixel compensation circuit of claim 2, wherein the threshold voltage measurement module comprises a second capacitor, a fourth transistor, a fifth transistor, a sixth transistor, and a seventh transistor; a gate of the fourth transistor is connected to the second scanning end, a source thereof is connected to the third node, and a drain is connected to the fifth node; a gate of the fifth transistor is connected to the light emitting control end, a source is connected to the fourth node, a drain is connected to the second power source, a second capacitor is connected across the fourth node and the fifth node; and a gate of the sixth transistor is connected to the light emission control The source is connected to the fifth node, and the drain is connected to the reference power source; the gate of the seventh transistor is connected to the third scan end, the drain is connected to the third power source, and the source is connected to the source a fifth node; the second capacitor is for storing the threshold voltage. The OLED pixel compensation circuit of claim 3, wherein the first transistor, the second transistor, and the third transistor, the fourth transistor sixth transistor, and the seventh transistor are N-channels The transistor, the driving transistor and the fifth transistor are P-channel transistors. The OLED pixel compensation circuit of claim 1, wherein a difference between the voltage output by the third power source and the output voltage of the second power source is greater than a threshold voltage of the driving transistor and an organic light emitting diode to be driven The sum of the threshold voltages of the polar bodies. The OLED pixel compensation circuit of claim 1, wherein the first power source outputs a positive voltage; the second power source is grounded; the third power source outputs a voltage greater than a voltage of the second power source and is smaller than the first power source Voltage. The valve OLED valve driving method is applicable to the OLED pixel driving method of the OLED pixel compensation circuit according to claim 3, which comprises the following steps: Step A, the re-determination process of the threshold voltage measuring module: the fifth power The crystal is connected to the second power source under the control of the illumination control end, and the threshold voltage measurement module charges the second capacitor using the third power source under the control of the third scanning end; step B, the threshold voltage measurement process The second scanning end configures the driving transistor to be a diode connection, and connects the third node and the fifth node; the second capacitor discharges until the driving transistor and the organic light emitting diode are turned off; step C, data voltage The writing process: the first scanning end control data voltage storage module obtains the data voltage from the data signal end, the data voltage is stored in the first capacitor; step D, the light emitting display process: the light emitting control end controls the fifth transistor to turn off Leading to the fourth node floating, thereby causing the first capacitor of the data voltage storage module, the second capacitor of the threshold voltage measuring module, and the voltage of the reference power source to be stacked in series A driving voltage is formed to the first node, and the driving transistor converts the driving voltage of the first node into a driving current for driving the organic light emitting diode under the control of the light emitting control end. The OLED pixel driving method of claim 7, wherein the current flowing through the organic light emitting diode is smaller than the minimum light emitting current of the organic light emitting diode when the OLED pixel compensation circuit is in the compensation process.