TWI527012B - Pixel circuit of light-emitting diode and driving method thereof - Google Patents

Description

Light-emitting diode pixel circuit and driving method thereof

The present invention relates to a pixel circuit, and more particularly to a light emitting diode pixel circuit and a driving method thereof.

In the light-emitting diode pixel circuit, a pixel configuration can be realized by using a light-emitting diode with four transistors and two capacitors, that is, using a so-called 4T2C circuit structure. In the 4T2C circuit architecture, one of the electro-optic systems is used as a driving transistor, and one of the capacitors is electrically coupled between the control terminal and the source terminal of the driving transistor. When the 4T2C circuit structure is used to enable the light emitting diode to emit light after the data is written, the control terminal of the driving transistor is floated and electrically coupled to the control terminal and the source of the driving transistor. Capacitance between the extremes to couple the voltage change of the source terminal of the driving transistor to the control terminal of the driving transistor, thereby compensating (or eliminating) the voltage across the LED itself and the threshold voltage (Vt) of the driving transistor The effect on the brightness of the light.

However, since each transistor itself has a parasitic capacitance, when the light emitting diode is illuminated, the capacitor is electrically coupled between the control terminal and the source terminal of the driving transistor from the source terminal of the driving transistor. The voltage coupled to the control terminal is divided by the parasitic capacitance described above (this can be called parasitic capacitance effect). Yes), the effect of the above compensation is not good. In order to solve the above problem, it is necessary to increase the capacitance value of the capacitance electrically coupled between the control terminal and the source terminal of the driving transistor, for example, increase the capacitance value of the capacitance between the control terminal and the source terminal of the driving transistor. To Ct, this will further lead to the reduction of the illuminating current of the illuminating diode and the slowing of the compensation speed.

The invention provides a light-emitting diode pixel circuit, which can avoid the problem that the light-emitting current of the light-emitting diode is reduced and the compensation speed is slow.

The present invention further provides a driving method suitable for the above-described light emitting diode pixel circuit.

The present invention provides a light emitting diode pixel circuit including a first transistor, a second transistor, a third transistor, a fourth transistor (used as a driving transistor), a first capacitor, a second capacitor, And a light-emitting diode. The first transistor has a control end, a first end, and a second end, and the control end of the first transistor is electrically coupled to the first control signal, and the first end of the first transistor is configured to receive the data potential Or reference potential. The second transistor has a control end, a first end, and a second end, and the control end of the second transistor is electrically coupled to the second control signal, and the first end of the second transistor is electrically coupled The first operating power supply. The third transistor has a control end, a first end, and a second end, and the control end of the third transistor is electrically coupled to the third control signal. The fourth transistor has a control end, a first end, and a second end, and the first end of the fourth transistor is electrically coupled to the second end of the second transistor, and the second end of the fourth transistor The second end of the third transistor is electrically coupled to the second end of the first transistor. The first capacitor has a first end and a second end. The first end of the first capacitor is electrically coupled to the control end of the fourth transistor, and the second end of the first capacitor and the second end of the fourth transistor And the third electricity The second ends of the crystals are electrically coupled together. The second capacitor has a first end and a second end, and the first end of the second capacitor, the second end of the first transistor, and the first end of the first capacitor are electrically coupled together, and the second capacitor The two ends are electrically coupled to the first end of the third transistor. In addition, the capacitance value of the second capacitor is greater than the capacitance value of the first capacitor. The light emitting diode has a first end and a second end, and the first end of the light emitting diode is electrically coupled to the second end of the fourth transistor, and the second end of the light emitting diode is electrically coupled Connected to the second operating power supply.

The invention further provides a light emitting diode pixel circuit, which comprises the above first transistor, second transistor, third transistor, fourth transistor, first capacitor, second capacitor, and light emitting diode In addition to the same electrical coupling relationship, the polar body further includes a fifth transistor. The fifth transistor has a control end, a first end and a second end, and the control end of the fifth transistor receives the fourth control signal, the first end of the fifth transistor is electrically coupled to the preset potential, and the fifth The second end of the transistor is electrically coupled to the first end of the third transistor.

The invention further provides a light emitting diode pixel circuit, comprising: a first transistor, a second transistor, a third transistor (used as a driving transistor), a light emitting diode and a capacitor module. The first transistor has a control end, a first end, and a second end, and the control end of the first transistor is electrically coupled to the first control signal, and the first end of the first transistor is configured to receive the data potential Or reference potential. The second transistor has a control end, a first end, and a second end, and the control end of the second transistor is electrically coupled to the second control signal, and the first end of the second transistor is electrically coupled to the second transistor The first operating power supply. The third transistor has a control end, a first end and a second end, and the first end of the third transistor is electrically coupled to the second end of the second transistor, and the control end of the third transistor is electrically The second end of the first transistor is coupled to the first transistor. The light emitting diode has a first end and a second end, and the first end of the light emitting diode is electrically coupled to the second end of the third transistor, and the second end of the light emitting diode is electrically coupled Connected to the second operating power supply. The capacitor module is electrically coupled to the control end and the second end of the third transistor And the capacitor module is configured to provide an equivalent capacitance between the control end and the second end of the third transistor, and the capacitor module is provided during the reset period and the illumination period of the diode pixel circuit The value of the equivalent capacitance is greater than the value of the equivalent capacitance provided by the diode pixel circuit during the compensation period and during the data write period.

The invention further provides a driving method of a light emitting diode pixel circuit for driving the above-mentioned light emitting diode pixel circuit having first to fourth transistors. The driving method includes: providing a first operating power source with a first potential during a reset period, and turning on the first transistor, the second transistor, and the third transistor, and simultaneously providing a reference potential to the first transistor One end; during the compensation period, causing the first operating power source to provide a second potential, the second potential being greater than the first potential, and turning on the first transistor and the second transistor, and simultaneously turning off the third transistor, and Providing a reference potential to the first end of the first transistor; during the data writing period, causing the first operating power source to provide the second potential, and turning on the first transistor and the third transistor, and turning off the second transistor, wherein The first transistor and the third transistor are not simultaneously turned on, and the on-time of the first transistor is prior to the on-time of the third transistor, and the data potential is supplied to the first transistor when the first transistor is turned on And one end; and, during the illuminating period, causing the first operating power source to provide the second potential, and turning off the first transistor, and turning on the second transistor and the third transistor, and providing the reference potential to the first transistor End. Wherein, the reset period precedes the compensation period, the compensation period precedes the data writing period, and the data writing period precedes the lighting period.

The present invention further provides a driving method for a light emitting diode pixel circuit for driving the above-described light emitting diode pixel circuit having first to fifth transistors, and the driving method includes: during the reset period, Turning on the first transistor, the third transistor and the fifth transistor while providing a reference potential to the first end of the first transistor; during the compensation period, turning on the first transistor and the second transistor while turning off the third a transistor and a fifth transistor, and providing a reference potential to the first end of the first transistor; during the data writing period, turning on the first transistor And a third transistor, and closing the second transistor and the fifth transistor, wherein the first transistor and the third transistor are not simultaneously turned on, and the on time of the first transistor is prior to the conduction of the third transistor Time, and providing a data potential to the first end of the first transistor when the first transistor is turned on; and, during the illuminating period, turning off the first transistor and the fifth transistor, and turning on the second transistor and the third a transistor, and providing a reference potential to the first end of the first transistor. Wherein, the reset period precedes the compensation period, the compensation period precedes the data writing period, and the data writing period precedes the lighting period.

In the circuit architecture of the illuminating diode pixel circuit of the present invention, a capacitor module composed of, for example, two capacitors and one transistor is electrically coupled between the control terminal and the source terminal of the driving transistor. And using the transistor to determine whether the two capacitors are electrically coupled between the control terminal and the source terminal of the driving transistor, or only one of the capacitors is electrically coupled to the control terminal of the driving transistor. Between the source terminal and the source terminal, the capacitance value of the equivalent capacitance electrically coupled between the control terminal and the source terminal of the driving transistor is changed during different operation periods of the light emitting diode pixel circuit. Accordingly, the light-emitting diode pixel circuit of the present invention can be avoided as long as the two capacitors are connected in parallel during the reset period and during the light-emitting period, and the two capacitors are turned off in parallel during the remaining two periods. There is a problem that the luminous current of the light-emitting diode in the conventional technique is reduced, and the compensation speed is slow.

100,200‧‧‧Light emitting diode driving circuit

11, 12, 13, 14, 15‧‧‧ transistors

C1, C2, C3‧‧‧ capacitors

20‧‧‧Lighting diode

110, 120, 130, 140, 150‧‧‧ control terminals

111, 121, 131, 141, 151, C11, C21, C31, 201‧‧‧ first end

112, 122, 132, 142, 152, C12, C22, C32, 202‧‧‧ second end

Scan, EM, Reset1, Reset2‧‧‧ control signals

Data‧‧‧Information Signal

Vdata‧‧‧ data potential

Vref‧‧‧ reference potential

Vsus‧‧‧Preset potential

OVDD, OVSS‧‧‧ operating power supply

OVDDH, OVDDL, H, L‧‧‧ potential

G, S‧‧‧ nodes

t‧‧‧Preset time

501, 502, 503, 504, 601, 602, 603, 604‧ ‧ steps

FIG. 1 is a circuit diagram of a light-emitting diode pixel circuit according to an embodiment of the present invention; FIG. 2 is a timing diagram of one of the light-emitting diode pixel circuits shown in FIG. 1; FIG. 3 is a circuit diagram of a light-emitting diode pixel circuit according to another embodiment of the present invention; FIG. 4 is a timing diagram of one of the light-emitting diode pixel circuits shown in FIG. 3; FIG. 5 is one of the operational flows of one of the light-emitting diode pixel circuits of the present invention; FIG. 6 is one of the operational flows of another light-emitting diode pixel circuit of the present invention.

FIG. 1 is a circuit diagram of a light emitting diode pixel circuit according to an embodiment of the invention. As shown in FIG. 1, the LED pixel circuit 100 includes a transistor 11, a transistor 12, a transistor 13, a transistor 14 (used as a driving transistor), a capacitor C1, a capacitor C2, and a light-emitting diode. 20. Further, in this example, the equivalent capacitance inherent to the light-emitting diode 20 itself is represented by C3. In addition, in this example, the capacitance value of the capacitor C2 is greater than the capacitance value of the capacitor C1, and the capacitance values of the two capacitors C1 and C2 are equal to those in the prior art, and are electrically coupled to the control end of the driving transistor. The equivalent capacitance between the source and the source is the capacitance value Ct after the capacitance is increased. The transistor 11 has a control end 110, a first end 111, and a second end 112. The control terminal 110 of the transistor 11 is electrically coupled to the control signal Scan to turn on or off the transistor 11 by the control signal Scan. The first end 111 of the transistor 11 is configured to receive the data signal Data, and the data signal Data can provide the data potential Vdata or the reference potential Vref to the first end 111 of the transistor 11.

The transistor 12 has a control end 120, a first end 121, and a second end 122. The control terminal 120 of the transistor 12 is electrically coupled to the control signal EM to turn on or off the transistor 12 by the control signal EM. The first end 121 of the transistor 12 is electrically coupled to the operating power source OVDD. The transistor 13 has a control terminal 130, The first end 131 and the second end 132. The control terminal 130 of the transistor 13 is electrically coupled to the control signal Reset1 to turn on or off the transistor 13 by the control signal Reset1. The transistor 14 has a control end 140, a first end 141, and a second end 142. The first end 141 of the transistor 14 is electrically coupled to the second end 122 of the transistor 12, and the second end 142 of the transistor 14 is electrically coupled to the second end 132 of the transistor 13, and the transistor The control terminal 140 of the 14 is electrically coupled to the second end 112 of the transistor 11 .

The capacitor C1 has a first end C11 and a second end C12. The first end C11 of the capacitor C1 is electrically coupled to the control end 140 of the transistor 14, and the second end C12 of the capacitor C1 is electrically connected to the second end 142 of the transistor 14 and the second end 132 of the transistor 13. Coupling. The capacitor C2 has a first end C21 and a second end C22. The first end C21 of the capacitor C2 is electrically coupled to the second end 112 of the capacitor 11 and the first end C11 of the capacitor C1, and the second end C22 of the capacitor C2 is electrically coupled to the first of the transistor 13. End 131. The light emitting diode 20 has a first end 201 and a second end 202. The first end 201 of the LED 20 is electrically coupled to the second end 142 of the transistor 14 , and the second end 202 of the LED 20 is electrically coupled to the operating power source OVSS .

FIG. 2 is a timing diagram of one of the signals of the LED pixel circuit shown in FIG. 1. As shown in FIG. 2, the LED pixel circuit 100 of FIG. 1 can be sequentially operated during a reset period, a compensation period, a data writing period, and a light-emitting period, wherein each signal can have a high level H and a low level. In the two states of the level L, when the high level H is applied to the gate of the N-type transistor, the N-type transistor can be turned on, but when the high level H is applied to the gate of the P-type transistor, the P is made. The transistor is turned off; conversely, when the low level L is applied to the gate of the N-type transistor, the N-type transistor is turned off, and when the low level L is applied to the gate of the P-type transistor, the P can be made. The type of transistor is turned on. The high level H can be, for example, equal to the potential OVDDH, and the low level L can be, for example, equal to the potential OVDDL. Referring to FIG. 1 and FIG. 2 together, the transistor 11 of the LED device 100 is turned on during the reset period, the compensation period, and the data writing period, and the first end 111 of the transistor 11 is written in the data. The data potential Vdata provided by the data signal Data is received during the input period, and the reference potential Vref provided by the data signal Data is received during the reset period, the compensation period, and the light-emitting period. The transistor 12 is used to be turned on during the reset period, the compensation period, and the light-emitting period, and the first end 121 of the transistor 12 receives the potential OVDDL provided by the operating power source OVDD during the reset period, and the first end of the transistor 12 The potential OVDDH supplied from the operation power source OVDD is received during the compensation period, the data writing period, and the light-emitting period, and the potential OVDDL is smaller than the potential OVDDH. The transistor 13 is used to conduct during reset, during data writing, and during illumination. In particular, during the data writing period, the on-times of the transistor 13 and the transistor 11 may be partially overlapped or not overlapped (not overlapping in FIG. 2), and the on-time of the transistor 13 is later than the electricity. The conduction time of the crystal 11. In addition, since the operating power source OVDD provides the potential OVDDL during the reset period, the potential on the node S will be OVDDL, and at this time, the capacitors C1 and C2 will discharge through the node S to reset the light-emitting diode pixel circuit 100.

As shown in FIG. 2, in detail, when the LED device 100 operates during the reset period, the transistor 11, the transistor 12, and the transistor 13 are respectively controlled by the signal Scan, the control signal EM, and The control signal Reset1 is turned on, and at this time, the first end 111 of the transistor 11 receives the reference potential Vref provided by the data signal Data, and the first end 121 of the transistor 12 receives the potential OVDDL provided by the operating power supply OVDD, so the node at this time The potential Vg of G will ideally be equal to Vref, and the potential Vs of node S will ideally be equal to OVDDL. Then, when the light emitting diode pixel circuit 100 operates during the compensation period When the transistor 11 is still in the on state, the first end 111 of the transistor 11 continues to receive the reference potential Vref provided by the data signal Data, and the transistor 12 remains in the on state, but the first end of the transistor 12 At the time of receiving the potential OVDDH provided by the operating power supply OVDD, the transistor 13 is turned off during this period, so the potential Vg of the node G is still Vref, and the potential Vs of the node S is determined by the potential OVDDL. The bit continues to rise to be equal to or substantially equal to Vref-Vth, where Vth is the threshold voltage of the transistor 14. Since the capacitance values of the two capacitors C1 and C2 are equal to those in the prior art, the equivalent capacitance between the control terminal and the source terminal of the driving transistor is increased by the capacitance value Ct after the capacitance is increased, and At this time, the entire LED pixel circuit 100 only needs to charge the capacitors C1 and C3 without charging the capacitor C2, thereby accelerating the speed of compensation.

Then, when the light-emitting diode pixel circuit 100 operates during data writing, the transistor 11 is turned off after a predetermined time t1, and before the transistor 11 is turned off, the first end of the transistor 11 111 will receive the data potential Vdata provided by the data signal Data. In addition, during the data writing period, the transistor 12 is turned off, and the transistor 13 is turned on after the preset time t1 (for example, after the data writing period t2 is turned on, that is, the transistor 13 and the transistor). The on-time of 11 is not overlapping), so the potential Vg of the node G is ideally equal to Vdata, and the potential of the node S is capacitively coupled to Vref-Vth+a(Vdata-Vref) because the node G When the Vref voltage level is changed to the Vdata voltage level, the transistor 13 is turned off, so a is C1/(C1+C3).

It can be seen from the above that since the capacitance value of the capacitor C1 is smaller than the capacitance value Ct of the equivalent capacitance between the control terminal and the source terminal of the prior art electrically coupled to the driving transistor, the capacitance value Ct is increased. Polar body pixel circuit When the data self-compensation period enters the data writing period, the voltage coupled to the node S by the node G becomes smaller, thus widening the voltage difference between the node G and the node S. As a result, the amount of current passing through the transistor 14 is increased, and the light-emitting current flowing through the light-emitting diode 20 can be increased.

Finally, when the light-emitting diode pixel circuit 100 operates during the light-emitting period, the transistor 11 remains turned off, the transistor 12 and the transistor 13 remain turned on, and the transistor 12 continues to receive the potential OVDDH provided by the operating power source OVDD. At this time, the potential variation of the node S is coupled to the node G, and the coupling amount thereof can be calculated by the equation (C1+C2)/(C1+C2+Cp), where Cp (not shown) is related to the node G. The parasitic capacitance value. As shown in the above formula, since the capacitance values of the capacitors C1 and C2 add up to the above-mentioned conventional techniques, the equivalent capacitance between the control terminal and the source terminal of the driving transistor is increased after the capacitance value is increased. Ct, therefore, this approach can also reduce the parasitic capacitance effect.

In the data writing period of another example, the time when the control signal Scan is shifted from the high level to the low level (low) may be later than the time when the control signal Reset1 is shifted from the low level to the high level. Therefore, the on-times of the transistor 13 and the transistor 11 are partially overlapped, thereby preventing the node G from being affected by the voltage coupled by the capacitors C1 and C2 due to the floating state during the transition state of the two control signals. Change its level.

Of course, in the embodiment shown in FIG. 1, the capacitor C3 represents the equivalent capacitance inherent to the LED 20 itself, but in the case where the capacitance of the equivalent capacitance inherent to the LED 20 is insufficient. The designer can connect a solid capacitor in parallel with the LED 20 so that the equivalent capacitance between the first end 201 and the second end 202 of the LED 20 can be inherent to the LED 20 itself. The effective capacitance is the sum of the capacitance values of the parallel capacitors.

FIG. 3 illustrates a light-emitting diode painting according to another embodiment of the present invention. The circuit architecture diagram of the prime circuit. In FIG. 3, the same reference numerals as in FIG. 1 denote the same elements or signals. As shown in FIG. 3, the LED structure of the LED pixel circuit 200 is substantially the same as that of the LED pixel circuit 100 of FIG. 1, except that the LED circuit 200 further includes a transistor 15. . The transistor 15 has a control terminal 150, a first end 151 and a second end 152, and the control terminal 150 of the transistor 15 receives the control signal Reset2, and the first end 151 of the transistor 15 is electrically coupled to a predetermined potential. The second end 152 of the transistor 15 is electrically coupled to the first end 131 of the transistor 13 . The second end 152 of the transistor 15 is electrically coupled to the first end 131 of the transistor 13 .

FIG. 4 is a timing diagram of one of the signals of the LED pixel circuit shown in FIG. 3. As shown in FIG. 4, the LED circuit 200 is also sequentially operated during the reset period, the compensation period, the data writing period, and the light-emitting period. The transistor 11 in the LED pixel circuit 200 is used to be turned on during the reset period, the compensation period, and the data writing period, and the first end 111 of the transistor 11 receives the data signal during the data writing period. The data potential Vdata is provided, and the reference potential Vref provided by the data signal Data is received during the reset period, the compensation period, and the light-emitting period. The transistor 12 in the light-emitting diode pixel circuit 200 is used to be turned on during the compensation period and during the light-emitting period. The transistor 13 in the light-emitting diode pixel circuit 200 is used to be turned on during the reset period, during the data writing period, and during the light-emitting period. In the data writing period, the on-times of the transistor 13 and the transistor 11 in the LED pixel circuit 200 may be partially overlapped or not overlapped (not overlapping in FIG. 4, and may be designed as The reason for the overlap is also as described previously, and the on-time of the transistor 13 is later than the on-time of the transistor 11. The transistor 15 in the LED pixel circuit 200 is used to be turned on during the reset period, and the first end 151 of the transistor 15 receives the preset potential Vsus during the reset period, and the preset potential Vsus Can have, for example, a potential OVDDL. Further, since the preset potential Vsus is supplied to one end of the capacitor C1 and one end of the capacitor C2 during the reset, the capacitors C1 and C2 are discharged at this time to reset the light-emitting diode pixel circuit 200.

Although in the previous description, the capacitor C1, the capacitor C2, and the transistor 13 are independent components, the three can also be regarded as one capacitor module. The capacitor module is configured to provide an equivalent capacitance between the control terminal 140 of the transistor 14 and the second end 142 of the transistor 14, and the capacitor module is in a reset state during the LED circuit and The capacitance of the equivalent capacitance provided during the light-emitting period is greater than the capacitance of the equivalent capacitance provided by the light-emitting diode pixel circuit during the compensation period and during the data writing period. The implementation of the capacitor module described above is for example only and is not intended to limit the present invention.

FIG. 5 is a flow chart of a driving method of a light emitting diode pixel circuit according to an embodiment of the present invention. Through the above description, the driving method of the light-emitting diode pixel circuit 100 can be summarized as steps 501 to 504 shown in FIG.

Step 501: During the reset period, the operating power source OVDD is supplied with the potential OVDDL, and the crystal 11, the transistor 12, and the transistor 13 are turned on, while the reference potential Vref is supplied to the first end 111 of the transistor 11. Step 502: During the compensation period, the operating power source OVDD is supplied with the potential OVDDH, the potential OVDDH is greater than the potential OVDDL, and the transistor 11 and the transistor 12 are turned on, and the transistor 13 is turned off, and the reference potential Vref is supplied to the first of the transistor 11. End 111. Step 503: During the data writing period, the operating power source OVDD is supplied with the potential OVDDH, and the transistor 11 and the transistor 13 are turned on, and the transistor 12 is turned off. The on-time of the transistor 11 and the transistor 13 is partially overlapped or not. Overlap, and the on-time of the transistor 11 precedes the on-time with the transistor 13, and provides the data potential Vdata to the first end 111 of the transistor 11 when the transistor 11 is turned on. Step 504: In the light emitting period, the operating power source OVDD is supplied with the potential OVDDH, The transistor 11 is turned off, and the conductive crystal 12 and the transistor 13 are electrically connected, and a reference potential Vref is supplied to the first end 111 of the transistor 11. In the above steps 501 to 504, the reset period precedes the compensation period, the compensation period precedes the data write period, and the data write period precedes the light emission period.

FIG. 6 is a flow chart of a driving method of a light emitting diode pixel circuit according to an embodiment of the present invention. Through the above description, the driving method of the light-emitting diode pixel circuit 200 can be summarized as steps 601 to 604 shown in FIG. 6.

Step 601: During the reset period, the conductive crystal 11, the transistor 13 and the transistor 15 are electrically connected while the reference potential Vref is supplied to the first end 111 of the transistor 11. Step 602: During the compensation period, the transistor 11 and the transistor 12 are electrically connected, and the transistor 13 and the transistor 15 are turned off at the same time, and the reference potential Vref is supplied to the first end 111 of the transistor 11. Step 603: During the data writing period, the conductive crystal 11 and the transistor 13 are turned on, and the transistor 12 and the transistor 15 are turned off, wherein the conduction time of the transistor 11 and the transistor 13 partially overlap or not overlap, and the transistor The on-time of 11 precedes the on-time of the transistor 13, and provides a data potential Vdata to the first end 111 of the transistor 11 when the transistor 11 is turned on. Step 604: During the illuminating period, the transistor 11 and the transistor 15 are turned off, and the crystal 12 and the transistor 13 are electrically connected, and the reference potential Vref is supplied to the first end 111 of the transistor 11. In the above steps 601 to 604, the reset period precedes the compensation period, the compensation period precedes the data writing period, and the data writing period precedes the lighting period.

In summary, in the circuit architecture of the LED pixel circuit of the present invention, a capacitor module composed of two capacitors and a transistor is electrically coupled to the control terminal of the driving transistor. Between the source and the terminal, the transistor is used to determine whether the two capacitors are electrically coupled between the control terminal and the source terminal of the driving transistor, or only one of the capacitors is electrically coupled to the driving. Between the control terminal and the source terminal of the transistor, thereby electrically changing the electrical coupling to the driving transistor during different operation periods of the LED substrate circuit The capacitance of the equivalent capacitance between the control terminal and the source terminal. Accordingly, the light-emitting diode pixel circuit of the present invention can be avoided as long as the two capacitors are connected in parallel during the reset period and during the light-emitting period, and the two capacitors are turned off in parallel during the remaining two periods. There is a problem that the luminous current of the light-emitting diode in the conventional technique is reduced, and the compensation speed is slow.

While the present invention has been described in its preferred embodiments, the present invention is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.

100‧‧‧Light Diode Pixel Circuit

11, 12, 13, 14‧‧‧ transistors

C1, C2, C3‧‧‧ capacitors

20‧‧‧Lighting diode

110, 120, 130, 140‧‧‧ control end

111, 121, 131, 141, C11, C21, C31, 201‧‧‧ first end

112, 122, 132, 142, C12, C22, C32, 202‧‧‧ second end

OVDD, OVSS‧‧‧ operating power supply

Scan, EM, Reset1‧‧‧ control signals

Data‧‧‧Information Signal

G, S‧‧‧ nodes

Claims (13)

A light-emitting diode pixel circuit includes: a first transistor having a control terminal, a first terminal, and a second terminal, wherein the control terminal of the first transistor is electrically coupled to a first control signal The first end of the first transistor is configured to receive a data potential or a reference potential; a second transistor has a control end, a first end, and a second end, the second transistor The control terminal is electrically coupled to a second control signal, the first end of the second transistor is electrically coupled to a first operating power source, and the third transistor has a control end, a first end, And a second end, the control end of the third transistor is electrically coupled to a third control signal; a fourth transistor having a control end, a first end, and a second end, the fourth The first end of the second transistor is electrically coupled to the second end of the second transistor, and the second end of the fourth transistor is electrically coupled to the second end of the third transistor. The control terminal of the fourth transistor is electrically coupled to the second end of the first transistor; a first capacitor has a first The second end of the first capacitor is electrically coupled to the control end of the fourth transistor, the second end of the first capacitor and the second end of the fourth transistor The second end is electrically coupled to the second end of the third transistor; the second capacitor has a first end and a second end, the first end of the second capacitor and the first transistor The second end is electrically coupled to the first end of the first capacitor, the second end of the second capacitor is electrically coupled to the first end of the third transistor, and the second capacitor The capacitance value is greater than the capacitance value of the first capacitor; and a light emitting diode having a first end and a second end, the first end of the light emitting diode being electrically coupled to the fourth transistor The second end of the hair The second end of the photodiode is electrically coupled to a second operating power source. The illuminating diode pixel circuit of claim 1, wherein the first transistor is used to be turned on during a reset period, a compensation period, and a data writing period, and the first transistor The first end receives the data potential during the data writing period, and receives the reference potential during the reset period, the compensation period and a light emitting period, the second transistor is used for the reset period, the compensation During the period and during the illuminating period, the first end of the second transistor receives a first potential provided by the first operating power source during the resetting, and the first end of the second transistor is Receiving a second potential provided by the first operating power source during the compensation period, the data writing period, and the lighting period, and the first potential is less than the second potential, the third transistor is used during the reset period And turning on during the data writing period and the illuminating period, during the data writing period, the conduction time of the third transistor and the first transistor is partially overlapped or not overlapped, and the third transistor is turned on. Time later than the first transistor The turn-on time, wherein the reset period precedes the compensation period, the compensation period precedes the data writing period, and the data writing period precedes the lighting period. The illuminating diode pixel circuit of claim 1, further comprising a third capacitor having a first end and a second end, the first end of the third capacitor The second end of the third capacitor is electrically coupled to the second end of the light emitting diode. The illuminating diode pixel circuit of claim 1, further comprising a fifth transistor having a control end, a first end and a second end, the fifth The control terminal of the transistor receives a fourth control signal The first end of the fifth transistor is electrically coupled to a predetermined potential, and the second end of the fifth transistor is electrically coupled to the first end of the third transistor. The illuminating diode pixel circuit of claim 4, wherein the first transistor is used to be turned on during a reset period, a compensation period, and a data writing period, and the first transistor The first end receives the data potential during the data writing period, and receives the reference potential during the reset period, the compensation period and a light emitting period, wherein the second transistor is used for the compensation period and the light emitting period Turning on, the third transistor is used to be turned on during the reset period, during the data writing period, and during the light emitting period, during the data writing period, the third transistor and the first transistor are turned on. Partially overlapping or not overlapping, and the conduction time of the third transistor is later than the conduction time of the first transistor, and the fifth transistor is used to be turned on during the reset period, and the fifth transistor is The first terminal receives the preset potential during the reset period, wherein the reset period precedes the compensation period, the compensation period precedes the data writing period, and the data writing period precedes the lighting period. A light-emitting diode pixel circuit includes: a first transistor having a control terminal, a first terminal, and a second terminal, wherein the control terminal of the first transistor is electrically coupled to a first control signal The first end of the first transistor is configured to receive a data potential or a reference potential; a second transistor has a control end, a first end, and a second end, the second transistor The control terminal is electrically coupled to a second control signal, the first end of the second transistor is electrically coupled to a first operating power source, and the third transistor has a control end, a first end, and a The second end of the third transistor is electrically coupled to the second end of the second transistor, and the control end of the third transistor is electrically coupled to the first transistor The second end; a light emitting diode having a first end and a second end, the first end of the light emitting diode being electrically coupled to the second end of the third transistor, the light emitting diode The second end is electrically coupled to a second operating power source; and a capacitor module is electrically coupled between the control end of the third transistor and the second end, the capacitor module is configured to provide the An equivalent capacitance between the control end of the third transistor and the second end, and the equivalent capacitance provided by the capacitor module during the reset period and a light emitting period of the diode pixel circuit The value is greater than the value of the equivalent capacitance provided by the diode pixel circuit during a compensation period and a data write period. The illuminating diode pixel circuit of claim 6, wherein the first transistor is used to be turned on during a reset period, a compensation period, and a data writing period, and the first transistor The first end receives the data potential during the data writing period, and receives the reference potential during the reset period, the compensation period and a light emitting period, the second transistor is used for the reset period, the compensation During the period and during the illuminating period, the first end of the second transistor receives a first potential provided by the first operating power source during the resetting, and the first end of the second transistor is Receiving a second potential provided by the first operating power source during the compensation period, the data writing period, and the lighting period, and the first potential is less than the second potential, wherein the reset period precedes the compensation period The compensation period precedes the data writing period, and the data writing period precedes the lighting period. The illuminating diode pixel circuit of claim 6, wherein the capacitor module comprises: a fourth transistor having a control end, a first end, and a second end, the fourth The control terminal of the transistor is electrically coupled to a third control signal; a first capacitor having a first end and a second end, the first capacitor The first end is electrically coupled to the control end of the third transistor, the second end of the first capacitor and the second end of the third transistor and the second end of the fourth transistor a second electrical capacitor having a first end and a second end, the first end of the second capacitor and the second end of the first transistor and the first capacitor The first end is electrically coupled to the first end of the fourth capacitor, and the capacitance of the second capacitor is greater than the capacitance of the first capacitor . The illuminating diode pixel circuit of claim 8, wherein the first transistor is used to be turned on during a reset period, a compensation period, and a data writing period, and the first transistor The first end receives the data potential during the data writing period, and receives the reference potential during the reset period, the compensation period and a light emitting period, the second transistor is used for the reset period, the compensation During the period and during the illuminating period, the first end of the second transistor receives a first potential provided by the first operating power source during the resetting, and the first end of the second transistor is Receiving a second potential provided by the first operating power source during the compensation period, the data writing period, and the illuminating period, and the first potential is less than the second potential, and the fourth transistor is used during the resetting period And turning on during the data writing period and the light emitting period, wherein the fourth transistor and the first transistor are partially overlapped or not overlapped during the data writing period, and the fourth transistor is turned on. Later than the guide of the first transistor The pass time, wherein the reset period precedes the compensation period, the compensation period precedes the data writing period, and the data writing period precedes the lighting period. The illuminating diode pixel circuit of claim 8, further comprising a fifth transistor having a control end and a first The first end of the fifth transistor receives a fourth control signal, and the first end of the fifth transistor is electrically coupled to a predetermined potential, the first portion of the fifth transistor The two ends are electrically coupled to the first end of the fourth transistor. The illuminating diode pixel circuit of claim 10, wherein the first transistor is used to be turned on during a reset period, a compensation period, and a data writing period, and the first transistor The first end receives the data potential during the data writing period, and receives the reference potential during the reset period, the compensation period and a light emitting period, wherein the second transistor is used for the compensation period and the light emitting period Turning on, the fourth transistor is configured to be turned on during the reset period, the data writing period, and the light emitting period, and the fourth transistor and the first transistor turn-on time during the data writing period Partially overlapping or non-overlapping, and an on-time of the fourth transistor is later than an on-time of the first transistor, and the fifth transistor is used to be turned on during the reset period, and the fifth transistor is The first terminal receives the preset potential during the reset period, wherein the reset period precedes the compensation period, the compensation period precedes the data writing period, and the data writing period precedes the lighting period. A driving method of a light emitting diode pixel circuit for driving the light emitting diode pixel circuit according to claim 1, wherein the driving method comprises: making the first operating power source during a reset period Providing a first potential, and conducting the first transistor, the second transistor and the third transistor, and simultaneously providing a reference potential to the first end of the first transistor; during a compensation period, The first operating power source provides a second potential, the second potential is greater than the first potential, and turns on the first transistor and the second transistor, simultaneously turns off the third transistor, and provides the reference potential to the The first end of the first transistor; The first operating power source provides the second potential during a data writing period, and turns on the first transistor and the third transistor, and turns off the second transistor, wherein the first transistor and the first transistor The on-time of the third transistor is partially overlapped or non-overlapping, and the on-time of the first transistor precedes the on-time of the third transistor, and provides a data potential to the first transistor when the first transistor is turned on a first end of a transistor; and during a light emitting period, causing the first operating power source to provide the second potential, and turning off the first transistor, and turning on the second transistor and the third transistor, And providing the reference potential to the first end of the first transistor, wherein the reset period precedes the compensation period, the compensation period precedes the data writing period, and the data writing period precedes the lighting period . A driving method of a light emitting diode pixel circuit for driving the light emitting diode pixel circuit according to claim 4, wherein the driving method comprises: turning on the first transistor during a reset period The third transistor and the fifth transistor simultaneously provide a reference potential to the first end of the first transistor; during a compensation period, the first transistor and the second transistor are turned on simultaneously Closing the third transistor and the fifth transistor, and providing the reference potential to the first end of the first transistor; during the data writing period, turning on the first transistor and the third transistor And closing the second transistor and the fifth transistor, wherein an on time of the first transistor and the third transistor partially overlaps or does not overlap, and an on time of the first transistor precedes the first a turn-on time of the tri-crystal, and providing a data potential to the first end of the first transistor when the first transistor is turned on; and turning off the first transistor and the fifth electrode during a light-emitting period Crystal, And conducting the second transistor and the third transistor, and providing the reference potential to the first end of the first transistor, wherein the reset period precedes the compensation period, the compensation period precedes the data During writing, the data is written during the pre-lighting period.