Pixel circuit and driving method to control charging or discharging of pixel capacitor

The present disclosure relates to a pixel circuit, a driving method of the same and a display apparatus.

With the development of liquid crystal display technique, an increasing number of electronic devices adopt a liquid crystal display as a display screen. The liquid crystal display comprises a driving integrated circuit (hereinafter referred to as driving IC in short) and a pixel circuit. The driving IC provides an analogy signal for a pixel circuit, and charges a pixel capacitor in the pixel circuit through this analogy signal.

The driving IC comprises a digital circuit part, a digital-analogy conversion circuit part and an analogy circuit part, and is configured to charge the pixel capacitor in the pixel circuit after converting a digital signal into the analogy signal. However, the digital circuit part, the digital-analogy conversion part and the analogy circuit part in the driving IC always have relatively complicated structure and large size, such that the driving IC has a complicated structure entirely and large size, which results in increasing manufacturing cost of the driving IC.

There are provided in several embodiments of the present disclosure a pixel circuit, a driving method of the same and a display apparatus, which are used to reduce manufacturing cost of a driving IC.

According to one aspect of the present disclosure, there is provided a pixel circuit. The pixel circuit comprises:

a selection circuit, whose input terminal is connected to a selection signal terminal, a high level signal terminal and a low level signal terminal, configured to control charging or discharging of a pixel capacitor according to a digital signal input by the selection signal terminal;

a charging/discharging circuit, whose input terminal is connected to an output terminal of the selection circuit and a same row gate line signal terminal corresponding to the pixel capacitor and output terminal is connected to the pixel capacitor, configured to charge or discharge the pixel capacitor under the control of the selection circuit; and

a pre-charging circuit, whose input terminal is connected to a previous row gate line signal terminal corresponding to the pixel capacitor and output terminal is connected to the pixel capacitor, configured to provide a reference voltage for the pixel capacitor.

Optionally, the selection circuit comprises:

a first transistor T 1 , whose gate is connected to the selection signal terminal, source is connected to the high level signal terminal, and drain is connected to the charging/discharging circuit;

a second transistor T 2 , whose gate is connected to the selection signal terminal, drain is connected to the low level signal terminal, and source is connected to the charging/discharging circuit.

Further, the selection signal terminal comprises a first data line and a second data line, level polarities of digital signals on the first data line and the second data line are opposite, the gate of the first transistor T 1 is connected to the first data line, and the gate of the second transistor T 2 is connected to the second data line.

Optionally, the charging/discharging circuit comprises:

a third transistor T 3 , whose gate is connected to the same row gate line signal terminal corresponding to the pixel capacitor, source is connected to the drain of the first transistor T 1 and the source of the second transistor T 2 , and drain is connected to the pixel capacitor.

Optionally, the pre-charging circuit comprises:

a fourth transistor T 4 , whose gate is connected to the previous row gate line signal terminal corresponding to the pixel capacitor, and both source and drain are connected to the pixel capacitor.

Further, both a digital signal on the first data line and a digital signal on the second data line are pulse digital signals whose duty ratio is adjustable.

Optionally, the selection circuit comprises:

a first transistor M 1 , whose gate is connected to the selection signal terminal, source is connected to the pixel capacitor, and drain is connected to the charging/discharging circuit;

a second transistor M 2 , whose gate is connected to the selection signal terminal, drain is connected to the low level signal terminal, and source is connected to the pre-charging circuit; and

a fifth transistor M 5 , whose gate is connected to the selection signal terminal, source is connected to the high level signal terminal, and drain is connected to the pre-charging circuit.

Further, the selection signal terminal comprises a data line and a selection signal line, the data line is connected to the gate of the first transistor M 1 , and the selection signal line is connected to the gate of the second transistor M 2 and the gate of the fifth transistor M 5 , and one of the second transistor M 2 and the fifth transistor M 5 is a P-type transistor, and the other thereof is a N-type transistor.

Optionally, the charging/discharging circuit comprises:

a third transistor M 3 , whose gate is connected to the same row gate line signal terminal corresponding to the pixel capacitor, source is connected to the drain of the first transistor M 1 , and drain is connected to the pixel capacitor.

Optionally, the pre-charging circuit comprises:

a fourth transistor M 4 , whose gate is connected to the previous row gate line signal terminal corresponding to the pixel capacitor, source is connected to the pixel capacitor, and drain is connected to the source of the second transistor M 2 and the drain of the fifth transistor M 5 .

Further, a digital signal on the data line is a pulse digital signal whose duty ratio is adjustable.

On the other hand, there is provided a driving method of a pixel circuit, comprising:

receiving an input signal of a previous row gate line signal terminal corresponding to a pixel capacitor, and providing a reference voltage for the pixel capacitor according to the input signal of the previous row gate line signal terminal by a pre-charging circuit;

receiving a digital signal of a selection signal terminal, and determining that a charging/discharging circuit charges or discharges according to the digital signal of the selection signal terminal by a selection circuit; and

receiving an input signal of a same row gate line signal terminal corresponding to the pixel capacitor, and charging or discharging the pixel capacitor according to the input signal of the same row gate line signal terminal by the charging/discharging circuit.

Optionally, that a pre-charging circuit receives an input signal of a previous row gate line signal terminal corresponding to a pixel capacitor, and provides a reference voltage for the pixel capacitor according to the input signal of the previous row gate line signal terminal, comprises:

a gate of a fourth transistor T 4 receives the input signal of the previous row gate line signal terminal corresponding to the pixel capacitor; and

when the input signal of the previous row gate line signal terminal is a high level signal, the fourth transistor T 4 is turned on to provide the reference voltage for the pixel capacitor.

Optionally, the selection signal terminal comprises a first data line and a second data line; that a selection circuit receives a digital signal of a selection signal terminal, and determines a charging/discharging circuit charges or discharges according to the digital signal of the selection signal terminal, comprises:

when a digital signal on the first data line is the high level signal, a digital signal on the second data line is a low level signal, the first transistor T 1 is turned on, the second transistor is turned off, and it is determined the charging/discharging circuit charges; and

when the digital signal on the first data line is the low level signal, the digital signal on the second data line is the high level signal, the first transistor T 1 is turned off, the second transistor is turned on, and it is determined the charging/discharging circuit discharges.

Optionally, that a charging/discharging circuit receives an input signal of a same row gate line signal terminal corresponding to the pixel capacitor, and charges or discharges the pixel capacitor according to the input signal of the same row gate line signal terminal, comprises:

a gate of a third transistor T 3 receives the input signal of the same row gate line signal terminal corresponding to the pixel capacitor; and

when the input signal of the same row gate line signal terminal is the high level signal, the third transistor T 3 is turned on to charge or discharge the pixel capacitor.

Further, both a digital signal on the first data line and a digital signal on the second data line are pulse digital signals whose duty ratio is adjustable.

Optionally, that a pre-charging circuit receives an input signal of a previous row gate line signal terminal corresponding to a pixel capacitor, and provides a reference voltage for the pixel capacitor according to the input signal of the previous row gate line signal terminal, comprises:

a fourth transistor M 4 receives the input signal of the previous row gate line signal terminal corresponding to the pixel capacitor; and

when the input signal of the previous row gate line signal terminal is the high level signal, the fourth transistor M 4 is turned on.

Optionally, the selection signal terminal comprises a data line and a selection signal line; a second transistor M 2 is a N-type transistor, and a fifth transistor M 5 is a P-type transistor; that the selection circuit receives the digital signal of the selection signal terminal, and determines that the charging/discharging circuit charges or discharges according to the digital signal of the selection signal terminal, comprises:

when an input signal on the selection signal line is the high level signal, the second transistor M 2 is turned off, the fifth transistor M 5 is turned on, and it is determined the charging/discharging circuit charges;

when the input signal on the selection signal line is the low level signal, the second transistor M 2 is turned on, the fifth transistor M 5 is turned off, and it is determined that the charging/discharging circuit discharges; and

when the digital signal on the data line is the high level signal, a source and drain of a first transistor M 1 are turned on.

Optionally, it further comprises:

when the input signal on the selection signal line is the high level signal, the second transistor M 2 is turned off, and the fifth transistor M 5 is turned on, to pre-charge the pixel capacitor; and

when the input signal on the selection signal line is the low level signal, the second transistor M 2 is turned on, and the fifth transistor M 5 is turned off, to pre-discharge the pixel capacitor.

Optionally, that a charging/discharging circuit receives an input signal of a same row gate line signal terminal corresponding to the pixel capacitor, and charges or discharges the pixel capacitor according to the input signal of the same row gate line signal terminal, comprises:

a gate of a third transistor M 3 receives the input signal of the same row gate line signal terminal corresponding to the pixel capacitor; and

when the input signal of the same row gate line signal terminal is the high level signal, the pixel capacitor is charged or discharged.

Further, the digital signal on the data line is a pulse digital signal whose duty ratio is adjustable.

On the other hand, there is provided a display apparatus, comprising the pixel circuit described above.

In the pixel circuit and the driving method of the same and the display apparatus provided in the embodiments of the present disclosure, the pixel circuit comprises the selection circuit, the charging/discharging circuit and the pre-charging circuit. The selection circuit is capable of controlling the charging/discharging circuit to charge or discharge the pixel capacitor according to the digital signal input by a connected selection signal terminal, so that the digital signal provided by the driving IC can be utilized directly to charge the pixel circuit, which saves the digital-analogy conversion circuit and the analogy circuit part in the driving IC, simplifies the structure of the driving IC, and at the same time reduces the size of the driving IC, thereby reducing the manufacturing cost of the driving IC.

FIG. 1 is a schematic diagram of a structure of a pixel circuit provided in a first embodiment of the present disclosure;

FIG. 2 is a flow diagram of a driving method of a pixel circuit provided in a first embodiment of the present disclosure;

FIG. 3 is a schematic diagram of a structure of a pixel circuit provided in a second embodiment of the present disclosure;

FIG. 4 is a signal timing diagram of the pixel circuit provided in FIG. 3 ;

FIG. 5 is a flow diagram of a driving method of a pixel circuit provided in a second embodiment of the present disclosure;

FIG. 6 is a schematic diagram of a structure of a pixel circuit provided in a third embodiment of the present disclosure;

FIG. 7 is a signal timing diagram of the pixel circuit provided in FIG. 6 ;

FIG. 8 is a flow diagram of a driving method of a pixel circuit provided in a third embodiment of the present disclosure.

In order to further describe a pixel circuit and a driving method of the same and a display apparatus provided in embodiments of the present disclosure, detailed description is provided below by combining with the figures of the specification.

First Embodiment

FIG. 1 shows a schematic diagram of a structure of a pixel circuit provided in a first embodiment of the present disclosure. Referring to FIG. 1 , the pixel circuit comprises a selection circuit P 1 , a charging/discharging circuit P 2 and a pre-charging circuit P 3 . In FIG. 1 , an input terminal of the selection circuit P 1 is connected to a selection signal terminal S, a high level signal terminal VH and a low level signal terminal VL, and an output terminal thereof is connected to a control terminal of the charging/discharging circuit 2 . The selection circuit P 1 is configured to control the charging/discharging circuit P 2 to charge or discharge the pixel capacitor C 1 according to a digital signal input by the selection signal terminal S. An input terminal of the charging/discharging circuit P 2 is connected to a same row gate line signal terminal Gn corresponding to the pixel capacitor C 1 , and an output terminal thereof is connected to one terminal of the pixel capacitor C 1 . The charging/discharging circuit P 2 is configured to charge or discharge the pixel capacitor C 1 under the control of the selection circuit P 1 . An input terminal of the pre-charging circuit P 3 is connected to a previous row gate line signal terminal G n-1 corresponding to the pixel capacitor C 1 , and an output terminal thereof is connected to another terminal of the pixel capacitor C 1 . The pre-charging circuit P 3 is configured to provide the reference voltage for the pixel capacitor C 1 . Herein, the selection signal terminal S outputs a digital signal. Exemplarily, one or more resistors for dividing a voltage can also be arranged in the pixel circuit.

It needs to note that when a pre-charging circuit in a current row of pixel circuit is pre-charging a pixel capacitor of a current row, a charging/discharging circuit in a previous row of pixel circuit is charging or discharging a pixel capacitor of a previous row.

FIG. 2 shows a flow diagram of a driving method of a pixel circuit provided in a first embodiment of the present disclosure. Referring to FIG. 2 , there is further provided in the embodiment of the present disclosure the driving method of the pixel circuit as shown in FIG. 1 . This method comprises following processes:

In step 101 , the pre-charging circuit receives an input signal of a previous row gate line signal terminal corresponding to the pixel capacitor, and provides a reference voltage for the pixel capacitor according to the input signal of the previous row gate line signal terminal.

In step 102 , the selection circuit receives a digital signal of the selection signal terminal, and determines that the charging/discharging circuit charges or discharges according to the digital signal of the selection signal terminal.

In step 103 , the charging/discharging circuit receives an input signal of a same row gate line signal terminal corresponding to the pixel capacitor, and charges or discharges the pixel capacitor according to the input signal of the same row gate line signal terminal.

There are provided in the embodiments of the present disclosure the pixel circuit and the driving method of the same. The pixel circuit comprises the selection circuit, the charging/discharging circuit and the pre-charging circuit. The selection circuit is capable of controlling the charging/discharging circuit to charge or discharge the pixel capacitor according to the digital signal input by a connected selection signal terminal, so that the digital signal provided by the driving IC can be utilized directly to charge the pixel circuit, which saves the digital-analogy conversion circuit and the analogy circuit part in the driving IC, simplifies the structure of the driving IC, and at the same time reduces the size of the driving IC, thereby reducing the manufacturing cost of the driving IC.

Second Embodiment

FIG. 3 shows a schematic diagram of a structure of a pixel circuit provided in a second embodiment of the present disclosure. Further, Referring to FIG. 3 , the selection circuit P 1 in the pixel circuit provided in the embodiment of the present disclosure comprises a first transistor T 1 and a second transistor T 2 . The charging/discharging circuit P 2 comprises a third transistor T 3 , the pre-charging circuit P 3 comprises a fourth transistor T 4 , and C 2 is a liquid crystal equivalent capacitor. A gate of the first transistor T 1 is connected to a first data line D 1 , a source thereof is connected to a high level signal terminal VH, and a drain thereof is connected to the charging/discharging circuit P 2 . A gate of the second transistor T 2 is connected to a second data line D 2 , a drain thereof is connected to a low level signal terminal VL, and a source thereof is connected to the charging/discharging circuit P 2 . A gate of the third transistor T 3 is connected to the same row of gate line signal terminal G n corresponding to pixel capacitor C 1 , a source thereof is connected to the drain of the first transistor T 1 and the source of the second transistor T 2 , and a drain thereof is connected to the pixel capacitor C 1 . A gate of the fourth transistor T 4 is connected to the previous row of gate line signal terminal G n-1 corresponding to the pixel capacitor C 1 , and a source and a drain thereof are connected to two terminals of the pixel capacitor C 1 respectively.

Exemplarily, one or more resistors can be arranged in the above pixel circuit. In FIG. 3 , the one or more resistors are equivalent to an equivalent resistor R, which is connected to the pixel capacitor C 1 . The selection signal terminal S can comprise the first data line D 1 and the second data line D 2 . Level polarities of digital signals on the first data line D 1 and the second data line D 2 are opposite. For example, when the digital signal on the first data line D 1 is the high level signal, the digital signal on the second data line D 2 is the low level signal; when the digital signal on the first data line D 1 is the low level signal, the digital signal on the second data line D 2 is the high level signal.

FIG. 4 is a signal timing diagram of the pixel circuit provided in FIG. 3 . By combing with the signal timing diagram as shown in FIG. 4 , operating principle of the pixel circuit as shown in FIG. 3 is described below by taking that the first transistor T 1 to the fourth transistor T 4 are N-type transistors as an example. The signal timing diagram as shown in FIG. 4 can be divided into 4 phases, which are a pre-charging phase w 1 , a charging phase w 2 , a discharging phase w 3 , and a charging ending phase w 4 , respectively.

In the pre-charging phase w 1 , the signal of the previous row gate line signal terminal G n-1 is the high level signal, and the fourth transistor T 4 is turned on to pre-charge the pixel capacitor C 1 until the voltage of the pixel capacitor C 1 reaches the reference voltage. The signal of the same row gate line signal terminal G n corresponding to the pixel capacitor C 1 is the low level signal, and the third transistor T 3 is turned off. Polarity of the digital signal on the first data line D 1 is not limited, and this digital signal may be the high level signal or may be the low level signal. Polarity of the digital signal on the second data line D 2 is opposite to the polarity of the digital signal on the first data line D 1 .

In the charging phase w 2 , the signal of the previous row gate line signal G n-1 is the low level signal, and the fourth transistor T 4 is turned off, pre-charging has already completed, the signal of the same row gate line signal terminal G n corresponding to the pixel capacitor C 1 is the high level signal, and the third transistor T 3 is turned on, the selection circuit P 1 is connected with the charging/discharging circuit P 2 . The digital signal on the first data line D 1 is the high level signal, the first transistor T 1 is turned on, the digital signal on the second data line D 2 is the low level signal, and the second transistor T 2 is turned off, and the high level signal terminal VH charges the pixel capacitor C 1 .

In the discharging phase w 3 , the signal of the same row gate line signal terminal G n corresponding to the pixel capacitor C 1 is the high level signal, the third transistor T 3 is turned on, and the selection circuit P 1 is connected with the charging/discharging circuit P 2 . The digital signal on the first data line D 1 is the low level signal, the first transistor T 1 is turned off, the digital signal on the second data line D 2 is the high level signal, the second transistor T 2 is turned on, and the low level signal terminal VL discharges the pixel capacitor C 1 .

In the charging ending phase w 4 , the signal of the same row gate line signal terminal G n corresponding to the pixel capacitor C 1 is the low level signal, the third transistor T 3 is turned off, and the selection circuit P 1 is disconnected from the charging/discharging circuit P 2 to stop charging or discharging the pixel capacitor.

In the above embodiment, both the digital signal on the first data line D 1 and the digital signal on the second data line D 2 are pulse digital signals whose duty ratio is adjustable, that is, a period of time during which the digital signal on the first data line D 1 is at a high level and a period of time during which the digital signal on the first data line D 1 is at a low level are adjustable, so that time for charging or discharging the pixel capacitor C 1 can be adjusted, and further the voltage of the pixel capacitor C 1 is adjusted.

FIG. 5 shows a flow diagram of a driving method of a pixel circuit provided in the second embodiment of the present disclosure. Referring to FIG. 5 , there is further provided in the embodiment of the present disclosure a driving method of the pixel circuit as shown in FIG. 3 . This method comprises following processes:

In step 201 , the gate of the fourth transistor T 4 receives the input signal of the previous row gate line signal terminal corresponding to the pixel capacitor C 1 .

In step 202 , when the input signal of the previous row gate line signal terminal is the high level signal, the fourth transistor T 4 is turned on, to provide the reference voltage for the pixel capacitor.

In step 203 , when the digital signal on the first data line is the high level signal, the digital signal on the second data line is the low level signal, the first transistor T 1 is turned on, the second transistor is turned off, and it is determined that the charging/discharging circuit charges.

In step 204 , when the digital signal on the first data line is the low level signal, the digital signal on the second data line is the high level signal, the first transistor T 1 is turned off, the second transistor is turned on, and it is determined the charging/discharging circuit discharges.

In step 205 , the gate of the third transistor T 3 receives the input signal of the same row gate line signal terminal corresponding to the pixel capacitor C 1 .

In step 206 , when the input signal of the same row gate line signal terminal is the high level signal, the third transistor T 3 is turned on, to charge or discharge the pixel capacitor.

In the embodiment as shown in FIG. 5 , if it is determined in step 203 that the charging/discharging circuit charges the pixel capacitor C 1 , then the pixel capacitor C 1 is charged in step 206 ; if it is determined in step 204 that the charging/discharging circuit discharges the pixel capacitor C 1 , then the pixel capacitor C 1 is discharged in step 206 .

There are provided in the embodiments of the present disclosure the pixel circuit and the driving method of the same. The pixel circuit comprises the selection circuit, the charging/discharging circuit and the pre-charging circuit. The selection circuit is capable of controlling the charging/discharging circuit to charge or discharge the pixel capacitor according to the digital signal input by a connected selection signal terminal, so that the digital signal provided by the driving IC can be utilized directly to charge the pixel circuit, which saves the digital-analogy conversion circuit and the analogy circuit part in the driving IC, simplifies the structure of the driving IC, and at the same time reduces the size of the driving IC, thereby reducing the manufacturing cost of the driving IC. At the same time, the time for charging or discharging the pixel capacitor can be adjusted by adjusting the duty ratio of the digital signals on the first data line and the second data line, so as to adjust the voltage value of the pixel capacitor.

Third Embodiment

FIG. 6 shows a schematic diagram of a structure of a pixel circuit provided in a third embodiment of the present disclosure. Further, Referring to FIG. 6 , the selection circuit P 1 in the pixel circuit comprises a first transistor M 1 , a second transistor M 2 , and a fifth transistor M 5 . The charging/discharging circuit P 2 comprises a third transistor M 3 , the pre-charging circuit P 3 comprises a fourth transistor M 4 , and C 2 is a liquid crystal equivalent capacitor. A gate of the first transistor M 1 is connected to the selection signal terminal S (not shown), a source thereof is connected to the pixel capacitor C 1 , and a drain thereof is connected to the charging/discharging circuit P 2 . A gate of the second transistor M 2 is connected to the selection signal terminal S (not shown), a drain thereof is connected to the low level signal terminal VL, and a source thereof is connected to the charging/discharging circuit P 3 . A gate of the fifth transistor M 5 is connected to the selection signal terminal S (not shown), a source thereof is connected to the high level signal terminal VH, and a drain thereof is connected to the pre-charging circuit P 3 . A gate of the third transistor M 3 is connected to the same row gate line signal terminal G n corresponding to pixel capacitor C 1 , a source thereof is connected to the drain of the first transistor M 1 , and a drain thereof is connected to the pixel capacitor C 1 . A gate of the fourth transistor M 4 is connected to the previous row gate line signal terminal G n-1 corresponding to the pixel capacitor C 1 , and a source thereof is connected to the pixel capacitor C 1 , and a drain thereof is connected to the source of the second transistor M 2 and the drain of the fifth transistor M 5 .

Exemplarily, one or more resistors can be arranged in the pixel circuit. In FIG. 6 , the one or more resistors are equivalent to an equivalent resistor R, which is connected to the pixel capacitor C 1 . The selection signal terminal S can comprise a data line D and a selection signal line SL. The data line D is connected to the gate of the first transistor M 1 , and the selection signal line SL is connected to the gate of the second transistor M 2 and the gate of the fifth transistor M 5 . One of the second transistor M 2 and the fifth transistor M 5 is a N-type transistor, and the other thereof is a P-type transistor, for example, when the second transistor M 2 is the N-type transistor, the fifth transistor M 5 is the P-type transistor; when the second transistor M 2 is the P-type transistor, the fifth transistor M 5 is the N-type transistor.

FIG. 7 shows a signal timing diagram of the pixel circuit provided in FIG. 6 . By combing with the signal timing diagram as shown in FIG. 7 , operating principle of the pixel circuit as shown in FIG. 6 is described by taking the second transistor M 2 being the P-type transistor and the fifth transistor M 5 being the N-type transistor as an example. Herein, the signal timing diagram as shown in FIG. 7 can be divided into 4 phases, i.e., a pre-charging phase w 15 , a pre-discharging phase w 6 , a charging/discharging phase w 7 and a charging/discharging ending phase w 8 .

In the pre-charging phase w 5 , the signal of the previous row gate line signal terminal G n-1 is the high level signal, the fourth transistor M 4 is turned on, the signal on the selection signal line SL is the high level signal, the second transistor M 2 is turned off, and the fifth transistor M 5 is turned on to pre-charge the pixel capacitor C 1 , the signal of the same row gate line signal terminal G n corresponding to the pixel capacitor C 1 is the low level signal, and the third transistor M 3 is turned off. Polarity of the digital signal on the data line is not limited, and this digital signal may be the high level signal or may be the low level signal.

In the pre-discharging phase w 6 , the signal of the previous row gate line signal terminal G n-1 is the high level signal, the fourth transistor M 4 is turned on, the signal of the selection signal line SL is the low level signal, the second transistor M 2 is turned on, and the fifth transistor M 5 is turned off to pre-discharge the pixel capacitor C 1 until the reference voltage is reached. The signal of the same row gate line signal terminal G n corresponding to the pixel capacitor C 1 is the low level signal, and the third transistor M 3 is turned off. Polarity of the digital signal on the data line is not limited, and this digital signal may be the high level signal, or may be the low level signal.

In the charging/discharging phase w 7 , the signal of the previous row gate line signal terminal G n-1 is the low level signal, the fourth transistor T 4 is turned off, pre-charging (including processes of pre-charging and/or pre-discharging) has already completed, the signal of the same row gate line signal terminal G n corresponding to the pixel capacitor C 1 is the high level signal, the selection circuit P 1 is connected with the charging/discharging circuit P 2 , the digital signal on the data line D is the high level signal, and the first transistor M 1 is turned on to charge or discharge the pixel capacitor C 1 .

In the charging/discharging ending phase w 8 , the signal on the data line D is the low level signal, the first transistor M 1 is turned off, and the selection circuit P 1 is disconnected from the charging/discharging circuit P 2 to stop charging or discharging the pixel capacitor.

Alternatively, the digital signal on the data line D is a pulse digital signal whose duty ratio is adjustable, that is, a period of time during which the digital signal on the data line D is at a high level and a period of time during which the digital signal on the data line D is at a low level are adjustable, so that time for charging or discharging the pixel capacitor C 1 can be adjusted, and further the voltage of the pixel capacitor C 1 is adjusted. FIG. 8 shows a flow diagram of a driving method of a pixel circuit provided in the third embodiment of the present disclosure. Referring to FIG. 8 , the driving method of the pixel circuit as shown in FIG. 6 comprises following processes:

In step 301 , the fourth transistor M 4 receives the input signal of the previous row gate line signal terminal corresponding to the pixel capacitor C 1 .

In step 302 , when the input signal of the previous row gate line signal terminal is the high level signal, the fourth transistor M 4 is turned on.

In step 303 , when the input signal on the selection signal line is the high level signal, the second transistor M 2 is turned off, and the fifth transistor M 5 is turned on, to pre-charge the pixel capacitor.

In step 304 , when the input signal on the selection signal line is the low level signal, the second transistor M 2 is turned on, the fifth transistor M 5 is turned off, to pre-charge the pixel capacitor.

In step 305 , when the input signal on the selection signal line is the high level signal, the second transistor M 2 is turned off, the fifth transistor M 5 is turned on, and it is determined that the charging/discharging circuit charges.

In step 306 , when the input signal on the selection signal line is the low level signal, the second transistor M 2 is turned on, and the fifth transistor M 5 is turned off, and it is determined that the charging/discharging circuit discharges.

In step 307 , when the digital signal on the data line is the high level signal, the first transistor M 1 is turned on.

In step 308 , the gate of the third transistor M 3 receives the input signal of the same row gate line signal terminal corresponding to the pixel capacitor.

In step 309 , when the input signal of the same row gate line signal terminal is the high level signal, the pixel capacitor is charged or discharged.

There are provided in the embodiments of the present disclosure the pixel circuit and the driving method of the same. The pixel circuit comprises the selection circuit, the charging/discharging circuit and the pre-charging circuit. The selection circuit is capable of controlling the charging/discharging circuit to charge or discharge the pixel capacitor according to the digital signal input by a connected selection signal terminal, so that the digital signal provided by the driving IC can be utilized directly to charge the pixel circuit, which omits the digital-analogy conversion circuit and the analogy circuit part in the driving IC, simplifies the structure of the driving IC, and at the same time reduces the size of the driving IC, thereby reducing the manufacturing cost of the driving IC. At the same time, the time for charging or discharging the pixel capacitor can be adjusted by adjusting the duty ratio of the digital signals on the first data line and the second data line, so as to adjust the voltage value of the pixel capacitor.

There is further provided in an embodiment of the present disclosure a display apparatus, comprising any of the pixel circuits described above. The display apparatus can be any product or means having a display function such as an electronic paper, a mobile phone, a tablet computer, a TV set, a display, a notebook computer, a digital photo frame, a navigator or the like.

In the description of the above implementations, specific features, structures, materials or characteristics can be combined in an appropriate manner in any one or more embodiments or examples.

The above descriptions are just specific implementations of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any alternation or replacement that can be easily conceived by those skilled in the art who are familiar with the technical field within the technical scope of the present disclosure shall be covered within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be subjected to the protection scope of the claims.

The present application claims the priority of a Chinese patent application No. 201510004106.3 filed on Jan. 4, 2015. Herein, the content disclosed by the Chinese patent application is incorporated in full by reference as a part of the present disclosure.