CN105679273A - Driving method of display panel, driving circuit and display device - Google Patents

Abstract

The invention provides a driving method, a driving circuit and a display device of a display panel, belonging to the field of display technology, which can at least partly solve the problem of high power consumption of the existing display panel. The driving method of the display panel of the present invention is used to provide driving current for multiple pixel structures in the display panel, comprising the following steps: acquiring the content and refresh frequency of the image to be displayed; resetting the driving frequency of the image to be displayed, and the driving frequency is less than or equal to Refresh frequency: Find the corresponding control signal according to the driving frequency, and send the bias current corresponding to the control signal as the driving current to the corresponding pixel structure in the display panel, and the bias current is not greater than the bias current corresponding to the refresh frequency. The driving method of the display panel adopts a small bias current as the driving current of the display panel when the display panel is driven at a low frequency (less than the refresh frequency), which can significantly reduce the power consumption of the display panel.

Description

Driving method, driving circuit and display device of display panel

technical field

The invention belongs to the field of display technology, and in particular relates to a driving method, a driving circuit and a display device of a display panel.

Background technique

With the development of technology, liquid crystal display devices are more and more widely used. At present, the composition of a liquid crystal display device, as shown in FIG. 1 , includes a display panel 1 and a driving circuit for driving the display panel 1 . The driving circuit includes a source driver 2 , a gate driver 3 and a timing controller 4 . Specifically, the timing controller 4 is used to transmit the image signal (DATA), the line start signal (STH), the latch signal (TP) and the polarity inversion signal (POL) to the source driver 2; the timing controller 4 It is also used to transmit the column start signal (STV), the column clock signal (CPV) and the output enable signal (OE) to the gate driver 3, so that the display panel 1 displays images. Wherein, the source driver 2 includes an output amplifier, and the output amplifier outputs a stable bias current to the display panel 1 to provide driving current for multiple pixel structures in the display panel 1 .

The inventor finds that there are at least the following problems in the prior art:

The bias current output by the output amplifier in the existing source driver is stable, that is to say, whether the display panel is driven at a normal frequency or driven at a reduced frequency, the bias current output by the output amplifier The setting currents are equal. However, in the case of reduced frequency driving, the actual required bias current is smaller. In the existing display panel, under any driving condition, the bias current remains constant, which will result in a huge waste of power consumption.

Therefore, designing a driving method for a display panel that can flexibly adjust the magnitude of the bias current according to actual needs, thereby reducing the power consumption of the display panel is an urgent technical problem to be solved at present.

Contents of the invention

In order to at least partly solve the existing above-mentioned problems, the present invention provides a driving method, a driving circuit and a display device of a display panel. The driving method and the driving circuit for realizing the driving method can flexibly adjust the size of the bias current according to actual needs, and can reduce the size of the bias current when the display panel is driven at a low frequency, thereby reducing the power consumption of the display panel.

The technical solution adopted to solve the technical problem of the present invention is to provide a driving method for a display panel, which is used to provide a driving current for a plurality of pixel structures in the display panel, comprising the following steps:

Obtain the content and refresh rate of the image to be displayed;

resetting the drive frequency of the image to be displayed, the drive frequency being less than or equal to the refresh rate;

Find the corresponding control signal according to the driving frequency, and send the bias current corresponding to the control signal as a driving current to the corresponding pixel structure in the display panel, and the bias current is not greater than the bias corresponding to the refresh frequency. setting current.

Preferably, before the step of resetting the driving frequency of the image to be displayed, it also includes:

Set the mapping table of driving frequency and control signal and set the mapping table of control signal and bias current, wherein: the mapping table of driving frequency and control signal includes the mapping of driving frequency and corresponding control code, control signal and bias current The table includes control codes and corresponding bias current levels.

Preferably, the control code is a digital mode, the number of the control code is 2 ^N , wherein N is a natural number greater than or equal to 1; the number of the bias current is 2 ^N , and the bias current The magnitude of is i/2 ^N of the bias current corresponding to the refresh frequency, where i is a natural number and 0≤i≤2 ^N .

Preferably, when the displayed image is a static picture, the driving frequency is reset to be less than the refresh frequency.

Preferably, the refresh frequency is 60Hz.

Another technical solution provided by the present invention: a drive circuit for a display panel, including a graphics unit, a timing controller, and a source drive unit, the timing controller includes a drive frequency resetting module and a mapping module, and the source driver The unit also includes a bias current matching block where:

The graphics unit is used to obtain the content and refresh rate of the image to be displayed;

The timing controller is configured to receive the refresh frequency of the graphics to be displayed, reset the drive frequency of the image to be displayed through the resetting driving frequency module, the driving frequency is less than or equal to the refresh frequency; and, through the mapping The module searches for a control signal corresponding to the driving frequency, and sends the control signal to the source drive unit;

The source drive unit is configured to receive the control signal, find the bias current corresponding to the control signal through the bias current matching module, and send the bias current as a driving current to the corresponding display panel. The pixel structure, the bias current is not greater than the bias current corresponding to the refresh frequency.

Preferably, the drive circuit of the display panel further includes a storage module, the timing controller further includes a signal setting module, and the source drive unit further includes a current setting module, wherein:

The signal setting module is used to set the mapping table of the driving frequency and the control signal, which includes the corresponding relationship between the driving frequency and the corresponding control code;

The current setting module is used to set the mapping table of the control signal and the bias current, which includes the corresponding relationship between the control code and the corresponding bias current;

The storage module is used to store a mapping table of driving frequency and control signal and a mapping table of control signal and bias current.

Preferably, the source driving unit includes a bias controller, and the bias controller generates a corresponding bias current according to the control signal and sends it to a corresponding pixel structure in the display panel.

Preferably, the source driver unit further includes an output amplifier connected between the bias controller and the pixel structure for amplifying the bias current and amplifying the The bias current is sent to the corresponding pixel structure in the display panel.

Preferably, the pixel structure in the display panel includes a thin film transistor, and the thin film transistor is a metal oxide thin film transistor.

Another technical solution provided by the present invention: a display device, including a display panel, and a driving circuit for the above-mentioned display panel.

In the driving method of the display panel and the driving circuit of the display panel provided by the present invention, by controlling the driving frequency of the display panel to be less than or equal to the refresh frequency, at the same time, setting the corresponding relationship between the driving frequency and the bias current, so that each size The bias current corresponding to the driving frequency is not greater than the bias current corresponding to the refresh frequency. Therefore, when the display panel is driven at a low frequency (less than the refresh rate), correspondingly, a relatively small bias current is used as the driving current of the display panel, which can significantly reduce the power consumption of the display panel.

The display device provided by the present invention can reduce the power consumption of the display panel by adopting the driving circuit of the display panel, thereby keeping the whole display device at a lower power consumption level and improving the use efficiency.

Description of drawings

1 is a schematic block diagram of the composition of a liquid crystal display device in the prior art;

2 is a schematic flowchart of a driving method of a display panel according to Embodiment 1 of the present invention;

FIG. 3 is a schematic block diagram of a driving circuit of a display panel according to Embodiment 2 of the present invention.

Wherein, reference sign is:

1. Display panel; 2. Source driver; 3. Gate driver; 4. Timing controller;

10. Graphics unit;

20. Timing controller; 21. Reset driving frequency module; 22. Mapping module; 23. Signal setting module;

30. Source drive unit; 31. Bias current matching module; 32. Current setting module; 33. Bias controller; 34. Output amplifier;

40. Storage module.

detailed description

In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Example 1:

This embodiment provides a method for driving a display panel, which is used to provide driving currents for multiple pixel structures in the display panel. The driving method can drive the display panel with a driving frequency less than or equal to the refresh frequency, and at the same time, use a small bias current as the driving current, thereby reducing the power consumption of the display panel.

FIG. 2 is a schematic flow chart of the driving method of the display panel in this embodiment. As shown in FIG. 2, the driving method of the display panel includes the following steps:

S1: Obtain the content and refresh rate of the image to be displayed.

According to the content of the image to be displayed, the driving timing and refresh frequency of each pixel structure in the display panel are determined. If the thin-film transistors used in the display panel to be driven are amorphous silicon thin-film transistors (a-SiTFT) or low-temperature polysilicon thin-film transistors (LTPSTFT), the required refresh frequency is generally 60Hz, that is, every 1/60s of the screen refresh of the display panel Once; if the thin film transistor used in the display panel to be driven is a metal oxide thin film transistor (IGZOTFT), because the leakage current of IGZOTFT is much smaller than that of a-SiTFT or LTPSTFT, which is less than 1pA, so the display panel of IGZOTFT type needs The refresh frequency of the display panel is generally only 5Hz, that is, the screen of the display panel is refreshed every 1/5s.

S2: Reset the driving frequency of the image to be displayed, and the driving frequency is less than or equal to the refresh frequency.

In step S2, according to the image displayed on the display panel in real time, the actual required driving frequency is determined to create conditions for selecting the minimum bias current that meets the requirements in the subsequent steps.

The driving frequencies mentioned here are all less than or equal to the refresh frequency, which can ensure that in the subsequent steps, the selected bias currents are all less than or equal to the bias current corresponding to the refresh frequency, thereby creating conditions for reducing the power consumption of the display panel.

When the image displayed on the display panel is a static image, it can be determined that the resetting driving frequency is less than the refreshing frequency. Judging whether the image displayed on the display panel is a static picture can be judged by reading the output data of the timing controller. For example, five consecutive frames of pictures are used as the judgment condition. Determine that the image displayed on the display panel is a static picture, and reset the driving frequency. Of course, more frames of pictures can also be used as the judgment condition, for example, ten consecutive frames of pictures as the judgment condition, which is not limited here.

Taking an IGZOTFT type display panel as an example, the reset driving frequency can be 1 Hz, and the displayed image is updated every 1 second, which can reduce the power consumption of the display panel. Moreover, conditions are created for the selected bias current to be smaller than the bias current corresponding to the refresh frequency in subsequent steps.

In addition, before the step of resetting the driving frequency of the image to be displayed, it also includes setting a mapping table of driving frequency and control signal and setting a mapping table of control signal and bias current.

Wherein: the mapping table of the driving frequency and the control signal includes the magnitude of the driving frequency and the corresponding control code, and the mapping table of the control signal and the bias current includes the control code and the corresponding magnitude of the bias current.

The control code is in digital mode, and the number of control codes is 2 ^N , where N is a natural number greater than or equal to 1; the number of bias currents is 2 ^N , and the magnitude of the bias current is i of the bias current corresponding to the refresh frequency /2 ^N , wherein, i is a natural number, and 0≤i≤2 ^N .

Generally, for an a-SiTFT or LTPSTFT type display panel, the range of driving frequency used is 30-60 Hz; for an IGZOTFT type display panel, the range of driving frequency used is 1-5 Hz. It can be seen that compared with a-SiTFT or LTPSTFT display panels, the IGZOTFT type display panel greatly reduces the driving frequency, and the power consumption is also reduced by about 1/10-1/5, which greatly reduces the power consumption. consumption.

Specifically, take an a-SiTFT or LTPSTFT type display panel as an example, and set the refresh frequency to 60 Hz, and set the control signal (CTL) to 2 groups. Correspondingly, the number of control codes is 4 (N=2), and the drive The magnitude of the frequency and the magnitude of the bias current are 4 respectively.

The mapping table of driving frequency and control signal is shown in Table 1:

Table 1 Mapping table of driving frequency and control signal

drive frequency CTL1 CTL2 60Hz 0 0 1Hz 0 1 20Hz 1 0 40Hz 1 1

The mapping table of control signal and bias current is shown in Table 2:

Table 2 Mapping table of control signal and bias current

In Table 1 and Table 2, "60Hz" means that the driving frequency equal to the refresh frequency is used to drive, and correspondingly, the control code is "00", and the corresponding bias current is the value of the bias current corresponding to the refresh frequency. size.

The remaining "1Hz", "20Hz", and "40Hz" all represent low frequency (less than the refresh frequency) for driving. Taking "20Hz" as an example, the corresponding control code is "10", and the corresponding bias current is 50% of the bias current corresponding to the refresh frequency. At this time, the power consumption of the display panel is only equivalent to the current There are ways to drive down to 50% of the power consumption, greatly reducing the power consumption of the display panel.

In the above example, the bias current is divided into 4 grades. Similarly, the bias current can also be divided into more grades, so that the difference between two adjacent bias currents is small, so that different drive Under the lower frequency, a more accurate bias current can be selected to avoid that the selected bias current is too much larger than the actual required bias current, resulting in waste of power consumption. Taking the bias current as 16 (N=4) grades as an example, the corresponding control signal and bias current mapping table is shown in Table 3:

Table 3 Mapping table of control signal and bias current

control code bias current control code bias current 00h 16/16 08h 8/16 01h 15/16 09h 7/16 02h 14/16 0Ah 6/16 03h 13/16 0Bh 5/16 04h 12/16 0Ch 4/16 05h 11/16 0Dh 3/16 06h 10/16 0Eh 2/16 07h 9/16 0Fh 1/16

At this time, the driving frequency is also divided into 16 grades correspondingly, which correspond to the control codes and bias currents in Table 3, so that the power consumption of the display panel can be further reduced.

S3: Find the corresponding control signal according to the driving frequency, and send the bias current corresponding to the control signal as the driving current to the corresponding pixel structure in the display panel, and the bias current is not greater than the bias current corresponding to the refresh frequency.

In step S3, according to the driving frequency reset in step S2 and the mapping table of driving frequency and control signal and the mapping table of control signal and bias current, select the bias current closest to the actual required bias current current, so as to ensure that the selected bias current can meet the working requirements and is the smallest among the required currents.

In this way, it can be ensured that the display panel uses the minimum bias current that meets the working requirements all the time in the process of displaying images, which can greatly reduce the power consumption of the display panel.

In the driving method of the display panel provided in this embodiment, by controlling the driving frequency of the display panel to be less than or equal to the refresh frequency, at the same time, setting the corresponding relationship between the driving frequency and the bias current, so that the bias current corresponding to the driving frequency of each size The setting current is not greater than the bias current corresponding to the refresh frequency. Therefore, when the display panel is driven at a low frequency (less than the refresh frequency), correspondingly, a relatively small bias current is used as the driving current of the display panel, which significantly reduces the power consumption of the display panel.

Example 2:

This embodiment provides a driving circuit for a display panel. The driving circuit can implement the driving method for the display panel in Embodiment 1 and reduce power consumption of the display panel.

FIG. 3 is a schematic block diagram of the composition of the driving circuit of the display panel of this embodiment. As shown in FIG. Including the resetting driving frequency module 21 and the mapping module 22 , the source driver unit 30 also includes a bias current matching module 31 .

Wherein, the graphics unit 10 is used to obtain the content and refresh rate of the image to be displayed; the timing controller 20 is used to receive the refresh rate of the image to be displayed, and reset the drive frequency of the image to be displayed by resetting the drive frequency module 21, the drive frequency Less than or equal to the refresh frequency; and, the mapping module 22 is used to find the control signal corresponding to the driving frequency, and the control signal is sent to the source driver unit 30; the source driver unit 30 is used to receive the control signal, and the bias current matching module 31 is used to find the control signal The bias current corresponding to the signal is sent to the corresponding pixel structure in the display panel as the driving current, and the bias current is not greater than the bias current corresponding to the refresh frequency.

Further, the driving circuit of the display panel further includes a storage module 40 , the timing controller 20 further includes a signal setting module 23 , and the source driving unit 30 further includes a current setting module 32 .

Wherein, the signal setting module 23 is used to set the mapping table of the driving frequency and the control signal, as shown in Table 1 in Embodiment 1, which includes the corresponding relationship between the driving frequency and the corresponding control code; the current setting module 32 is used to set the control The mapping table of the signal and the bias current, as shown in Table 2 in Embodiment 1, it includes the corresponding relationship between the control code and the corresponding bias current size; the storage module 40 is used to store the mapping table of the driving frequency and the control signal and the control A mapping table of signals and bias currents, and the storage module 40 is connected to the timing controller 20 and the source driving unit 30 respectively.

The source driving unit 30 includes a bias controller 33 , and the bias controller 33 generates a corresponding bias current according to a control signal and sends it to a corresponding pixel structure in the display panel. Wherein, when the bias controller 33 generates the corresponding bias current according to the control signal, the bias controller 33 will refer to the mapping table of the control signal and the bias current stored in the storage module 40, so that according to the received control The signal generates the corresponding bias current. Correspondingly, when the mapping module 22 searches for the control signal corresponding to the driving frequency, the mapping module 22 will also refer to the mapping table of the driving frequency and the control signal stored in the storage module 40, thereby finding the corresponding control signal according to the driving frequency, And send the control signal to the source driving unit 30 .

Specifically, the source driving unit 30 also includes an output amplifier 34, which is connected between the bias controller 33 and the pixel structure, and is used to amplify the bias current and send the amplified bias current to the display The corresponding pixel structure in the panel.

The driving circuit of the display panel in this embodiment can be used as a driving circuit of any one of the IGZOTFT display panel, a-SiTFT display panel and LTPSTFT display panel. Wherein, compared with a-SiTFT or LTPSTFT, the leakage current of IGZOTFT is smaller than that of a-SiTFT or LTPSTFT, which is less than 1pA, so a relatively low driving frequency can be used, thereby reducing the power consumption of the display panel. Therefore, the driving circuit of the display panel provided by this embodiment is preferably used as the driving circuit of the IGZOTFT display panel, which can reduce the power consumption of the display panel to a greater extent and improve the economic benefit of the product.

The driving circuit of the display panel in this embodiment can control the driving frequency of the display panel to be less than or equal to the refresh frequency, and at the same time, make the bias current corresponding to each driving frequency not greater than the bias current corresponding to the refresh frequency. Therefore, not only the display panel is driven at a low frequency (less than the refresh rate), but also a relatively small bias current is used as the driving current of the display panel, which can significantly reduce the power consumption of the display panel.

Example 3:

This embodiment provides a display device, which includes a display panel, and further includes the driving circuit for the display panel in Embodiment 2. Wherein, the display panel may be any one of IGZOTFT display panel, a-SiTFT display panel and LTPSTFT display panel.

It is easy to understand that the display device of this embodiment further includes other conventional components, such as a gate driving unit.

The display device in this embodiment may be any product or component with a display function, such as electronic paper, mobile phone, tablet computer, television, monitor, notebook computer, digital photo frame, and navigator.

Because the display device of this embodiment includes the driving circuit of the display panel in Embodiment 2, the power consumption of the display panel can be significantly reduced; the overall power consumption of the display device will also be significantly reduced.

It can be understood that, the above embodiments are only exemplary embodiments adopted for illustrating the principle of the present invention, but the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also regarded as the protection scope of the present invention.

Claims (11)

1. a driving method for display floater, is used to the multiple pixels in display floaterStructure provides drive current, it is characterized in that, comprises the following steps:

Obtain content and the refreshing frequency of image to be displayed;

Reset the driving frequency of image to be displayed, described driving frequency is less than or equal to described brushNew frequency;

Search corresponding control signal according to described driving frequency, and by described control signalCorresponding bias current is sent to pixel knot corresponding in display floater as drive currentStructure, described bias current is all not more than bias current corresponding to described refreshing frequency.

2. the driving method of display floater according to claim 1, its feature existsIn, before the step of driving frequency of reseting image to be displayed, also comprise:

The mapping table of driving frequency and control signal is set and control signal is set and biasingThe mapping table of electric current, wherein: the mapping table of driving frequency and control signal comprises drivingThe control routine that frequency is big or small and corresponding, wraps in the mapping table of control signal and bias currentDraw together control routine and corresponding bias current size.

3. the driving method of display floater according to claim 2, its feature existsIn, described control routine is figure pattern, the quantity of described control routine is 2^NIndividual, itsMiddle N is more than or equal to 1 natural number; The quantity of described bias current is 2^NIndividual, and instituteThe size of stating bias current is the i/2 of bias current corresponding to described refreshing frequency^N, wherein,I is natural number and 0≤i≤2^N。

4. the driving method of display floater according to claim 1, its feature existsIn, when showing that image is while being tableaux, reset described driving frequency and refresh described in being less thanFrequency.

5. according to the driving method of the arbitrary described display floater of claim 1-4, its spyLevy and be, described refreshing frequency is 60Hz.

6. a drive circuit for display floater, comprise graphic element, time schedule controller andSource drive unit, is characterized in that, described time schedule controller comprises resets driving frequencyModule and mapping block, described source drive unit also comprises bias current matching module,Wherein:

Described graphic element, for obtaining content and the refreshing frequency of image to be displayed;

Described time schedule controller, for receiving the refreshing frequency of figure to be shown, by instituteState the driving frequency of reseting driving frequency module and reset image to be displayed, described driving frequencyBe less than or equal to described refreshing frequency; And, search described driving by described mapping blockThe control signal that frequency is corresponding, is sent to described source drive unit by described control signal;

Described source drive unit, for receiving described control signal, by described biasingBias current corresponding to control signal described in currents match module searches, and by described biasingElectric current is sent to dot structure corresponding in display floater, described biasing as drive currentElectric current is all not more than bias current corresponding to described refreshing frequency.

7. the drive circuit of display floater according to claim 6, its feature existsIn, the drive circuit of described display floater also comprises memory module, described time schedule controllerAlso comprise signal setting module, described source drive unit also comprises that electric current arranges module,Wherein:

Described signal setting module, for the mapping table of driving frequency and control signal is set,It comprises the corresponding relation of the big or small and corresponding control routine of driving frequency;

Described electric current arranges module, for the mapping table of control signal and bias current is set,It comprises the corresponding relation of control routine and corresponding bias current size;

Described memory module, for the mapping table of storing driver frequency and control signal andThe mapping table of control signal and bias current.

8. the drive circuit of display floater according to claim 6, its feature existsIn, described source drive unit comprises offset controller, described offset controller is according to instituteStating control signal generates corresponding bias current and is sent in described display floater correspondingDot structure.

9. the drive circuit of display floater according to claim 8, its feature existsIn, described source drive unit also comprises output amplifier, described output amplifier connectsBetween described offset controller and described dot structure, for described biased electrical is flow toRow amplifies, and the described bias current after amplifying is sent in described display floater correspondingDot structure.

10. according to the drive circuit of the arbitrary described display floater of claim 6-9, itsBe characterised in that, the dot structure in described display floater comprises thin film transistor (TFT), described thinFilm transistor is metal oxide thin-film transistor.

11. 1 kinds of display unit, comprise display floater, it is characterized in that, also comprise powerProfit requires the drive circuit of the arbitrary described display floater of 6-10.