CN103150991A - A pixel compensation circuit for AMOLED display - Google Patents

Abstract

The invention provides a pixel compensation circuit, comprising: a first switch, a first end of which receives a data voltage and a second end of which receives a first switch signal; a second switch, a second end of which receives the first switch signal; a third switch having a second terminal and a third terminal both connected to a first voltage; a fourth switch; a fifth switch, a first terminal of which receives a reference voltage, and a second terminal of which receives a third switch signal; a sixth switch, a second end of which receives the third switch signal; a first capacitor; a first end of the second capacitor is connected to a second end of the first capacitor, and a second end of the second capacitor receives a second switching signal; and an organic light emitting diode, a first end of which is connected to the first end of the sixth switch, and a second end of which is connected to the second voltage. Compared with the prior art, the invention compensates the threshold voltage of the switch before the lighting period, eliminates the influence of the threshold voltage on the OLED current, and ensures that the OLED in the pixel can maintain stable current output.

Description

A pixel compensation circuit for AMOLED display

technical field

The invention relates to an active matrix organic light emitting diode display, in particular to a pixel compensation circuit of the AMOLED display.

Background technique

Organic light emitting diodes (Organic Light Emitting Diode, OLED) can be divided into passive matrix driving (Passive Matrix OLED, PMOLED) and active matrix driving (Active Matrix OLED, AMOLED) according to the driving method. Among them, the PMOLED does not emit light when data is not written, but only emits light during data writing. This driving method is simple in structure, low in cost, and easy to design, and is mainly suitable for small and medium-sized displays.

The biggest difference between AMOLED and PMOLED is that each pixel has a capacitor to store data, so that each pixel can maintain a light-emitting state. Since the power consumption of AMOLED is significantly lower than that of PMOLED, and its driving method is suitable for the development of large-size and high-resolution displays, AMOLED will become the main direction of future development. However, in the driving mechanism of the AMOLED display, the OLED controls the luminance of light based on the magnitude of the current flowing through it, and the electrical parameters of the thin film transistor used for driving will directly affect the display effect of the picture. For example, due to the influence of the manufacturing process, the threshold voltage (threshold voltage) of the thin film transistor in each pixel may drift. At this time, even if the same data voltage is provided to these pixels, the current flowing through the OLED of each pixel will still increase. There are differences, resulting in uneven brightness in AMOLED displays.

In view of this, how to design a pixel compensation circuit for AMOLED displays to effectively improve or eliminate many defects such as uneven brightness and poor display picture quality is a subject to be solved urgently by relevant technical personnel in the industry.

Contents of the invention

Aiming at the above-mentioned defects in the pixel compensation circuit for AMOLED display in the prior art, the present invention provides a novel pixel compensation circuit that can improve uneven brightness.

According to one aspect of the present invention, a pixel compensation circuit for an AMOLED display is provided, including:

A first switch has a first end, a second end and a third end, the first end is used to receive a data voltage, and the second end is used to receive a first switch signal;

A second switch has a first end, a second end and a third end, the second end of which is used to receive the first switch signal;

a third switch having a first terminal, a second terminal and a third terminal, both of the second terminal and the third terminal are electrically connected to a first voltage;

A fourth switch has a first end, a second end and a third end, its first end is electrically connected to the second end of the third switch, and its second end is electrically connected to the first end the first end of the three switches, the third end of which is electrically connected to the third end of the second switch;

A fifth switch has a first end, a second end and a third end, the first end is used to receive a reference voltage, the second end is used to receive a third switch signal, and the third end is Sexually connected to the third end of the first switch;

A sixth switch has a first end, a second end and a third end, the second end is used to receive the third switch signal, and the third end is electrically connected to the first end of the second switch three terminals;

A first capacitor has a first end and a second end, its first end is electrically connected to the third end of the first switch, and its second end is electrically connected to the first end of the third switch end;

A second capacitor has a first end and a second end, its first end is electrically connected to the second end of the first capacitor and the first end of the second switch, and its second end is used for receiving a second switch signal; and

An organic light emitting diode has a first end and a second end, the first end is electrically connected to the first end of the sixth switch, and the second end is electrically connected to a second voltage, wherein the The second voltage is smaller than the first voltage.

Preferably, the first switch to the sixth switch are all thin film transistors.

Preferably, the combination of the first switch signal, the second switch signal and the third switch signal corresponds to a data holding period, a reset period, a voltage compensation period and a lighting period in sequence.

In one embodiment, during the data holding period, both the first switch signal and the second switch signal are at low level, and the third switch signal is at high level.

In one embodiment, during the reset period, the first switch signal is at low level, the second switch signal jumps from low level to high level, and the third switch signal is at high level.

In one embodiment, during the voltage compensation period, the first switch signal is at low level, the second switch signal jumps from high level to low level, and the third switch signal is at high level.

In one embodiment, during the lighting period, the first switch signal is at high level, the second switch signal is at low level, and the third switch signal is at low level.

Preferably, during the reset period, the voltage Vg of the second terminal of the fourth switch satisfies the relational expression: Vg=OVDD+︱V _th︱

Preferably, during the voltage compensation period, the voltage Vg of the second terminal of the fourth switch satisfies the relationship: Vg=OVDD-︱V _th︱

Preferably, during the lighting period, the voltage Vg of the second terminal of the fourth switch satisfies the relationship: Vg=OVDD-︱V _th︱ +V _ref -V _data

Wherein, OVDD represents the first voltage, V _th represents the threshold voltage threshold of the thin film transistor, V _ref represents the reference voltage, and V _data represents the data voltage.

The pixel compensation circuit of the present invention is used to drive the current of the OLED through a 6T2C structure composed of six switches and two capacitors. The first end of the first switch receives a data voltage, and the second ends of the first switch and the second switch respectively Simultaneously receive a first switch signal, the second terminal of the third switch and the second terminal are connected to a first voltage, the respective second terminals of the fifth switch and the sixth switch receive a third switch signal at the same time, the first capacitor The first terminal is connected to the third terminal of the first switch and the second terminal of the first capacitor is connected to the first terminal of the third switch, and the first terminal of the second capacitor is connected to the second terminal of the first capacitor and the second switch The first terminal of the second capacitor and the second terminal of the second capacitor receive a second switch signal. Compared with the prior art, the present invention compensates the threshold voltage of the thin film transistor before the lighting period, and eliminates the dependence of the OLED current on the threshold voltage, so that the OLED in the pixel can maintain a stable current output.

Description of drawings

Readers will have a clearer understanding of various aspects of the present invention after reading the detailed description of the present invention with reference to the accompanying drawings. in,

FIG. 1 shows a schematic diagram of a pixel compensation circuit for an AMOLED display using a 6T1C architecture in the prior art;

FIG. 2 shows a schematic diagram of a pixel compensation circuit for an AMOLED display using a 6T2C architecture according to an embodiment of the present invention;

Fig. 3a shows a schematic diagram of the working state of each switch of the pixel compensation circuit in Fig. 2 during the data holding period;

FIG. 3b shows a schematic timing diagram of key signals of the pixel compensation circuit in FIG. 3a;

FIG. 4a shows a schematic diagram of the working state of each switch of the pixel compensation circuit in FIG. 2 during the reset period;

FIG. 4b shows a schematic timing diagram of key signals of the pixel compensation circuit in FIG. 4a;

Fig. 5a shows a schematic diagram of the working state of each switch of the pixel compensation circuit in Fig. 2 during voltage compensation;

FIG. 5b shows a schematic timing diagram of key signals of the pixel compensation circuit in FIG. 5a;

Fig. 6a shows a schematic diagram of the working state of each switch of the pixel compensation circuit in Fig. 2 during the lighting period; and

FIG. 6b shows a timing diagram of key signals of the pixel compensation circuit in FIG. 6a.

Detailed ways

In order to make the technical content disclosed in this application more detailed and complete, reference may be made to the drawings and the following various specific embodiments of the present invention, and the same symbols in the drawings represent the same or similar components. However, those skilled in the art should understand that the examples provided below are not intended to limit the scope of the present invention. In addition, the drawings are only for schematic illustration and are not drawn according to their original scale.

The specific implementation manners of various aspects of the present invention will be further described in detail below with reference to the accompanying drawings.

FIG. 1 shows a schematic diagram of the principle of a pixel compensation circuit for an AMOLED display using a 6T1C architecture in the prior art, and FIG. 2 shows a schematic timing diagram of key signals of the pixel compensation circuit in FIG. 1 .

Referring to FIG. 1 , the pixel compensation circuit is a "6T1C" structure, where 6T refers to thin film transistors M1-M6, and 1C refers to the storage capacitor Cs provided at the connection point between the gate of thin film transistor M4 and thin film transistors M1 and M3. That is, the term "mTnC" indicates that the number of thin film transistors is m, and the number of storage capacitors is n, where m and n are both natural numbers.

The circuit structure of the 6T1C is specifically described as follows: the first end of the storage capacitor Cs is electrically connected to a first switch signal S1. The first end of the thin film transistor M1 is electrically coupled to the second end of the storage capacitor Cs, the second end of the thin film transistor M1 is electrically coupled to a first voltage VDD, the third end of the thin film transistor M1 is connected to the second end electrically coupled together. The second end of the thin film transistor M5 is used to receive a third switching signal EM, and the third end of the thin film transistor M5 is electrically coupled to the first voltage VDD. The first end of the thin film transistor M2 is electrically coupled to the first end of the thin film transistor M5, the second end of the thin film transistor M2 is used to receive a second switching signal S2, and the third end of the thin film transistor M2 is electrically connected to a data Voltage Vdata.

The first end of the thin film transistor M4 is electrically coupled to the first end of the thin film transistor M2 and the first end of the thin film transistor M5, and the second end of the thin film transistor M4 is electrically coupled to the first end of the thin film transistor M1 and the storage capacitor The second end of Cs. The first end of the thin film transistor M3 is electrically coupled to the second end of the thin film transistor M4, the second end of the thin film transistor M3 is used to receive the second switch signal S2, and the third end of the thin film transistor M3 is electrically coupled to the thin film transistor M4. The third terminal of the transistor M4. The first terminal of the thin film transistor M6 is electrically coupled to the third terminal of the thin film transistor M3, and the second terminal of the thin film transistor M6 is used for receiving the third switch signal EM. The anode of the organic light emitting diode OLED is electrically coupled to the third terminal of the thin film transistor M6, and the cathode thereof is connected to the second voltage VSS.

However, the electrical parameters of the thin film transistor used for driving will directly affect the display effect of the picture. Due to the influence of the manufacturing process, the threshold voltage of the thin film transistor in each pixel often drifts. At this time, even if the same data voltage is provided to these pixels, the current flowing through the OLED of each pixel will still be different, resulting in AMOLED display. Brightness is uneven.

In order to effectively solve the above defects, the present invention provides a novel pixel compensation circuit architecture. FIG. 2 shows a schematic diagram of a pixel compensation circuit for an AMOLED display using a 6T2C architecture according to an embodiment of the present invention.

Referring to FIG. 2, the pixel compensation circuit of the present invention adopts a 6T2C structure, including a first switch T1, a second switch T2, a third switch T3, a fourth switch T4, a fifth switch T5, a sixth switch T6, a first capacitor C1 and The second capacitor C2.

The first switch T1 has a first terminal (such as a source, the same below), a second terminal (such as a gate, the same below) and a third terminal (such as a drain, the same below). The source of the first switch T1 is used to receive a data voltage Vdata, and the gate is used to receive a first switch signal S1. The gate of the second switch T2 is used to receive the first switch signal S1 , and the source is electrically coupled to the first terminal of the second capacitor C2 and the second terminal of the first capacitor C1 . The gate and the source of the third switch T3 are both electrically connected to a first voltage OVDD.

The source of the fourth switch T4 is electrically connected to the gate of the third switch T3, the gate of the fourth switch T4 is electrically connected to the drain of the third switch T3, and the drain of the fourth switch T4 is electrically connected to the first The drain of the second switch T2. The source of the fifth switch T5 is used to receive a reference voltage Vref, the gate of the fifth switch T5 is used to receive a third switch signal EM, and the drain of the fifth switch T5 is electrically connected to the drain of the first switch T1 . The gate of the sixth switch T6 is used to receive the third switch signal EM, and the source of the sixth switch T6 is electrically connected to the drain of the second switch T2 and the drain of the fourth switch T4.

Moreover, the first capacitor C1 has a first end and a second end, the first end of the first capacitor C1 is electrically connected to the drain of the first switch T1, and the second end of the first capacitor C1 is electrically connected to to the drain of the third switch T3. The second capacitor C2 has a first terminal and a second terminal, the first terminal of the second capacitor C2 is electrically connected to the second terminal of the first capacitor C1 and the source of the second switch T2, the second capacitor C2 The second end of the second end is used to receive the second switch signal S2. An anode of the organic light emitting diode OLED is electrically connected to the drain of the sixth switch T6, and a cathode thereof is electrically connected to a second voltage OVSS, and the second voltage OVSS is lower than the first voltage OVDD.

In a specific embodiment, the first switch T1 to the sixth switch T6 are all thin film transistors.

In a specific embodiment, the combination of the first switch signal S1, the second switch signal S2 and the third switch signal EM corresponds to a data holding period P1, a reset period P2, a voltage compensation period P3 and a lighting period in sequence P4. That is to say, the operation of the pixel compensation circuit of the present invention can be divided into several cycle periods, and each cycle period first performs a data hold operation, and then performs a reset operation, then compensates the threshold voltage of the thin film transistor, and finally clicks Bright organic light emitting diodes.

FIG. 3 a shows a schematic diagram of the working state of each switch of the pixel compensation circuit in FIG. 2 during data retention, and FIG. 3 b shows a schematic timing diagram of key signals of the pixel compensation circuit in FIG. 3 a .

Referring to FIG. 3a and FIG. 3b, in the data holding period P1, both the first switch signal S1 and the second switch signal S2 are at low level, and the third switch signal EM is at high level. At this time, the fifth switch T5 and the sixth switch T6 are in an off state. The first switch T1 is in an open state under the action of the first switch signal S1 , the drain potential of the first switch T1 is the data voltage Vdata, and the gate potential of the fourth switch T4 is in a floating state.

FIG. 4 a shows a schematic diagram of the working state of each switch of the pixel compensation circuit in FIG. 2 during the reset period, and FIG. 4 b is a schematic diagram of the timing sequence of key signals of the pixel compensation circuit in FIG. 4 a .

4a and 4b, in the reset period P2, the first switch signal S1 is at low level, the second switch signal S2 jumps from low level to high level, and the third switch signal EM is at high level. At this time, the fifth switch T5 and the sixth switch T6 are in an off state, and the fourth switch T3 is also in an off state. The first switch T1 is in an open state under the action of the first switch signal S1, the drain potential of the first switch T1 is the data voltage Vdata, and the gate potential Vg of the fourth switch T4 satisfies the relational expression:

Vg=OVDD+︱V _th︱

Wherein, OVDD represents the first voltage, and V _th represents the threshold voltage threshold of the thin film transistor.

FIG. 5 a shows a schematic diagram of the working state of each switch of the pixel compensation circuit in FIG. 2 during voltage compensation, and FIG. 5 b shows a timing diagram of key signals of the pixel compensation circuit in FIG. 5 a .

5a and 5b, in the voltage compensation period P3, the first switch signal S1 is at low level, the second switch signal S2 jumps from high level to low level, and the third switch signal EM is at high level. At this time, the fifth switch T5 and the sixth switch T6 are still in the off state, and the third switch T3 is also in the off state. The first switch T1 is in an open state under the action of the first switch signal S1, and the potential of the drain of the first switch T1 is the data voltage Vdata. And the gate potential Vg of the fourth switch T4 can satisfy the relational expression:

Vg=OVDD-︱V _th︱

Wherein, OVDD represents the first voltage, and V _th represents the threshold voltage threshold of the thin film transistor.

FIG. 6a shows a schematic diagram of the working state of each switch of the pixel compensation circuit in FIG. 2 during the lighting period, and FIG. 6b is a schematic timing diagram of key signals of the pixel compensation circuit in FIG. 6a .

6a and 6b, in the lighting period P4, the first switch signal S1 is at high level, the second switch signal S2 is at low level, and the third switch signal EM is also at low level. At this time, the fifth switch T5 and the sixth switch T6 are in the open state under the action of the third switch signal EM, and the first switch T1 and the second switch T2 are in the off state under the action of the first switch signal S1, and The third switch T3 is also in an off state. At this time, the potential of the drain of the first switch T1 is the reference voltage Vref. And the gate potential Vg of the fourth switch T4 satisfies the relational expression:

Vg=OVDD-︱V _th︱ +V _ref -V _data

Wherein, OVDD represents the first voltage, V _th represents the threshold voltage threshold of the thin film transistor, V _ref represents the reference voltage, and V _data represents the data voltage.

Calculate the current flowing through the organic light-emitting diode OLED according to the aforementioned mathematical relationship again:

${\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; \&kappa;</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; sg</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; the\; th</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}$

Since the gate potential Vg of the fourth switch T4 is equal to (OVDD-|V _th |+V _ref -Vdata), and the source potential Vs of the fourth switch T4 is equal to OVDD, then

V _sg ＝OVDD-(OVDD-|V _th |+V _ref -Vdata)

that is,

${\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; \&kappa;</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; sg</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; the\; th</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}$

$<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; \&kappa;</span>}<span\; class="notranslate">\; \&CenterDot;</span>{<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; OVDD</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; OVDD</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; the\; th</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; ref</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; Vdata</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; the\; th</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; ]</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}$

$<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&CenterDot;</span>\mathrm{<span\; class="notranslate">\; \&kappa;</span>}<span\; class="notranslate">\; \&CenterDot;</span>{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; Vdata</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; ref</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}$

It can be known that the current flowing through the organic light emitting diode OLED is only related to the data voltage Vdata and the reference voltage Vref, and has nothing to do with the threshold voltage of the thin film transistor.

Using the pixel compensation circuit of the present invention, the OLED is driven by current through a 6T2C architecture composed of six switches and two capacitors, the first end of the first switch receives a data voltage, and the second ends of the first switch and the second switch respectively Simultaneously receive a first switch signal, the second terminal of the third switch and the second terminal are connected to a first voltage, the respective second terminals of the fifth switch and the sixth switch receive a third switch signal at the same time, the first capacitor The first terminal is connected to the third terminal of the first switch and the second terminal of the first capacitor is connected to the first terminal of the third switch, and the first terminal of the second capacitor is connected to the second terminal of the first capacitor and the second switch The first terminal of the second capacitor and the second terminal of the second capacitor receive a second switch signal. Compared with the prior art, the present invention compensates the threshold voltage of the thin film transistor before the lighting period, eliminating the dependence of OLED current on the threshold voltage, so that the OLED in the pixel can maintain a stable current output.

Hereinbefore, specific embodiments of the present invention have been described with reference to the accompanying drawings. However, those skilled in the art can understand that without departing from the spirit and scope of the present invention, various changes and substitutions can be made to the specific embodiments of the present invention. These changes and substitutions all fall within the scope defined by the claims of the present invention.

Claims (10)

1. A pixel compensation circuit for an Active Matrix Organic Light Emitting Diode (AMOLED) display, the pixel compensation circuit comprising:

a first switch having a first end, a second end and a third end, wherein the first end is used for receiving a data voltage, and the second end is used for receiving a first switch signal;

a second switch having a first end, a second end and a third end, the second end for receiving the first switch signal;

a third switch having a first end, a second end and a third end, wherein the second end and the third end are both electrically connected to a first voltage;

a fourth switch having a first end, a second end and a third end, wherein the first end is electrically connected to the second end of the third switch, the second end is electrically connected to the first end of the third switch, and the third end is electrically connected to the third end of the second switch;

a fifth switch having a first end, a second end and a third end, wherein the first end is used for receiving a reference voltage, the second end is used for receiving a third switch signal, and the third end is electrically connected to the third end of the first switch;

a sixth switch having a first end, a second end and a third end, the second end for receiving the third switch signal, the third end electrically connected to the third end of the second switch;

a first capacitor having a first end and a second end, wherein the first end is electrically connected to the third end of the first switch, and the second end is electrically connected to the first end of the third switch;

a second capacitor having a first end and a second end, wherein the first end is electrically connected to the second end of the first capacitor and the first end of the second switch, and the second end is used for receiving a second switch signal; and

an Organic Light Emitting Diode (OLED) having a first end and a second end, wherein the first end is electrically connected to the first end of the sixth switch, and the second end is electrically connected to a second voltage, wherein the second voltage is less than the first voltage.

2. The pixel compensation circuit of claim 1, wherein the first switch to the sixth switch are all a thin film transistor.

3. The pixel driving circuit according to claim 1, wherein a combination of the first switching signal, the second switching signal, and the third switching signal sequentially corresponds to a data holding period, a reset period, a voltage compensation period, and a lighting period.

4. The pixel compensation circuit according to claim 3, wherein the first switching signal and the second switching signal are both at a low level and the third switching signal is at a high level during the data holding period.

5. The pixel compensation circuit according to claim 4, wherein the first switching signal is at a low level, the second switching signal jumps from a low level to a high level, and the third switching signal is at a high level during the reset period.

6. The pixel compensation circuit according to claim 5, wherein during the voltage compensation, the first switching signal is at a low level, the second switching signal jumps from a high level to a low level, and the third switching signal is at a high level.

7. The pixel compensation circuit according to claim 6, wherein the first switching signal is at a high level, the second switching signal is at a low level, and the third switching signal is at a low level during the lighting period.

8. The pixel compensation circuit of claim 3, wherein during the reset period, the voltage Vg of the second terminal of the fourth switch satisfies the relation:

Vg=OVDD+︱V_th︱

wherein OVDD represents the first voltage, V_thRepresenting the threshold voltage threshold of the thin film transistor.

9. The pixel compensation circuit of claim 3, wherein during the voltage compensation, the voltage Vg of the second terminal of the fourth switch satisfies the relation:

Vg=OVDD-︱V_th︱

wherein OVDD represents the first voltage, V_thRepresenting the threshold voltage threshold of the thin film transistor.

10. The pixel compensation circuit of claim 3, wherein during the lighting period, the voltage Vg of the second terminal of the fourth switch satisfies the relation:

Vg=OVDD-︱V_th︱+V_ref-V_data

wherein OVDD represents the first voltage, V_thRepresenting the threshold voltage, V, of the thin film transistor_refRepresents the reference voltage, V_dataRepresenting the data voltage.

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