Patent Grant
10529297
This is a National Phase Application filed under 35 U.S.C. 371 as a national stage of PCT/CN2017/100193, filed on Sep. 1, 2017, an application claiming priority to Chinese Patent Application No. 201710002188.7, filed on Jan. 3, 2017 in the Chinese Intellectual Property Office, the present disclosure of which is incorporated by reference herein.
The present disclosure relates to the field of display technologies, and in particular relates to a display panel, a method for compensating a common voltage thereof, and a display device.
With the increasing popularity of TFT-LCDs in people's daily lives, the quality requirements for TFT-LCD display screens are also increasing. Therefore, there is a need for higher quality design for existing products. For certain special screens, to prevent a greenish phenomenon and a line afterimage phenomenon of display from occurring is an important part of high quality design.
Specifically, the greenish phenomenon of the TFT-LCD refers to a phenomenon that under certain special screens (such as 1Dot127, 2Dot127, etc.), the human eyes observe that the screen displayed by a display panel is green, and the line afterimage phenomenon refers to a phenomenon that line residue appears at the border between black and white when the display panel is switched to a pure grayscale screen, after displaying a black and white checkerboard for a long period of time. There are many causes for the greenish phenomenon and the line afterimage phenomenon. The most important cause is that the resistance or capacitance of a data line of the display panel is so large that a common voltage VCOM is pulled.
According to an aspect of the disclosure, a display panel is provided. The display panel may include a plurality of compensation regions. Each of the plurality of compensation regions is provided with a respective common electrode. The display panel further includes a compensation circuit corresponding to each of the plurality of compensation regions. The compensation circuit may compensate an actual common voltage of the respective common electrode in a corresponding compensation region, according to an average value of a difference between the actual common voltage and a preset common voltage of the respective common electrode in the corresponding compensation region.
Optionally, he compensation circuit may include a compensation sub-circuit, an acquisition sub-circuit, and a calculation sub-circuit; the acquisition sub-circuit may obtain actual common voltages of a plurality of common electrodes in the corresponding compensation region; the calculating sub-circuit may calculate an average value of differences in common voltage of the plurality of common electrodes in the corresponding compensation region, according to the actual common voltage and the preset common voltage of each common electrode; and the compensation sub-circuit may compensate the actual common voltage of each common electrode in the corresponding compensation region, according to the average value of the differences in common voltage of the plurality of common electrodes in the corresponding compensation region.
Optionally, a plurality of pixel units are disposed in each compensation region; the acquisition sub-circuit may include a pixel voltage detection unit and a calculation unit; the pixel voltage detecting unit may detect a pixel voltage in each of the plurality of pixel units in the corresponding compensation region; and the calculation unit may calculate the actual common voltage of each of the plurality of common electrodes in the corresponding compensation region according to the pixel voltage.
Optionally, the calculating sub-circuit may include a capacitor, a first resistor, and an amplifier; a first terminal of the amplifier is connected to a preset common voltage terminal, a second terminal of the amplifier is connected to the first resistor, and an output terminal of the amplifier is connected to a compensation common voltage terminal; and a first terminal of the capacitor is connected to an actual common voltage terminal, and a second terminal of the capacitor is connected to the first resistor.
Optionally, the compensation sub-circuit may include a plurality of compensation resistors; and the plurality of compensation resistors are connected in parallel with each other, and each of the plurality of compensation resistors is connected to the second terminal and the output terminal of the amplifier, respectively.
Optionally, the compensation sub-circuit further may include a plurality of compensation switches, each of the compensation switches is connected in series with a respective one of the plurality of compensation resistors, and the plurality of compensation switches are configured to be either turned on or turned off according to a compensation multiple corresponding to one of the plurality of compensation resistors.
Optionally, the plurality of compensation regions are arranged in a matrix.
According to an aspect of the disclosure, a method for compensating a common voltage of a display panel is provided. The display panel may include a plurality of compensation regions, and each of the plurality of compensation regions is provided with a respective common electrode; and for each of the plurality of compensation regions, the method may include a step of: compensating an actual common voltage of the respective common electrode in the compensation region, according to an average value of a difference between an actual common voltage and a preset common voltage of the respective common electrode in the compensation region.
Optionally, the step of compensating an actual common voltage of the respective common electrode in the compensation region, according to an average value of a difference between the actual common voltage and a preset common voltage of the respective common electrode in the compensation region, may include steps of: obtaining actual common voltages of a plurality of common electrodes in the compensation region; calculating an average value of differences in common voltage of the plurality of common electrodes in the compensation region, according to the actual common voltage and the preset common voltage of each common electrode; and compensating the actual common voltage of each common electrode in the compensation region, according to the average value of the differences in common voltage of the plurality of common electrodes in the compensation region.
Optionally, the step of obtaining actual common voltages of a plurality of common electrodes in the compensation region, may include steps of: detecting a pixel voltage in each of a plurality of pixel units in the compensation region; and calculating the actual common voltage of each of the plurality of common electrodes in the compensation region according to the pixel voltage.
Optionally, the compensation sub-circuit may include a plurality of compensation resistors; and the step of compensating the actual common voltage of each common electrode in the compensation region, according to the average value of the differences in common voltage of the plurality of common electrodes in the compensation region, may include: compensating the actual common voltage of each of the common electrodes in the compensation region by selecting one of a plurality of compensation resistors that corresponds to one of compensation multiples which are stored in advance, according to the average value of the differences in common voltage of the plurality of common electrodes in the compensation region and the compensation multiples.
According to an aspect of the disclosure, a display device is provided. The display device may include the display panel described above.
To enable those skilled in the art to better understand the technical solutions of the present disclosure, the present disclosure will be further described in detail below in conjunction with the accompanying drawings and specific implementations.
In order to solve the above problem, an existing method for improving the greenish phenomenon and the line afterimage phenomenon is to reduce a pulled amplitude of the VCOM by compensating the common voltage VCOM. Specifically, referring to
In practical applications, the pulled amplitude of the common voltage VCOM in the middle region of the display panel 1 is typically larger than the pulled amplitude of the common voltage VCOM in the periphery region. However, the wiring is usually set only on the outer edge of the display panel 1 in order to input the reverse compensation voltage, so that the common voltage VCOM in the middle region of the display panel 1 is not compensated, and the greenish phenomenon and the line afterimage phenomenon cannot be effectively improved.
Referring to
Referring to
As shown in
Referring to
Specifically, first, the acquisition sub-circuit 6 acquires the actual common voltage of the corresponding common electrode 3 in each of the compensation regions 4. Then, in the case that the preset common voltage of each common electrode 3 is known, the calculation sub-circuit 7 calculates the difference between the actual common voltage and the preset common voltage of each common electrode 3. The differences of all the common electrodes 3 in the compensation region 4 is added to obtain a sum, and then the sum is divided by the number of the common electrodes 3 in the compensation region 4 to obtain the average value of the differences in common voltage of the corresponding common electrodes 3 in the compensation region 4. Finally, the compensation sub-circuit 5 may compensate the actual common voltage of each common electrode 3 in each compensation region 4, according to the average value in each compensation region 4.
It should be noted that since the actual common voltage of each common electrode 3 is compensated according to the average value of the differences in common voltage of the corresponding common electrodes 3 in the compensation region 4, not every compensated actual common voltages of the common electrodes 3 are equal to the corresponding theoretical preset common voltages. The display panel of this embodiment may only reduce the pulled amplitude of each common electrode 3 in each compensation region 4 to effectively improve the greenish phenomenon and the line afterimage phenomenon, and improve the display effect.
A plurality of pixel units may be disposed in each compensation region 4, and the acquisition sub-circuit 6 may include a pixel voltage detection unit 61 and a calculation unit 62. The pixel voltage detection unit 61 may detect a pixel voltage of each pixel unit in the corresponding compensation region 4. The calculation unit 62 may calculate the actual common voltage of each common electrode 3 in the compensation region 4 based on the pixel voltage.
That is, in the present embodiment, the actual common voltage of the common electrode 3 is obtained according to the pixel voltage of each pixel unit in the compensation region 4. The reason is that the pixel voltage is measurable, but there is no good method for measuring the common voltage at present. Moreover, the actual common voltage of the common electrode 3 obtained through the pixel voltage has a higher accuracy and a smaller error.
The calculation sub-circuit 7 includes a capacitor C1, a first resistor R1 and an amplifier. A first terminal of the amplifier is connected to a preset common voltage terminal. A second terminal of the amplifier is connected to the first resistor R1. An output of the amplifier is connected to a compensation common voltage terminal. A first terminal of the capacitor C1 is connected to the actual common voltage terminal, and a second terminal of the capacitor C1 is connected to the first resistor R1.
Referring to
The compensation sub-circuit 5 includes a plurality of compensation resistors R2 to R5. The plurality of compensation resistors R2 to R5 are connected in parallel with each other, and each compensation resistor is connected to the output terminal and the second terminal of the amplifier, respectively.
Referring to
The compensation sub-circuit 5 further includes a plurality of compensation switches K1 to K4, each compensation switch is connected in series with one compensation resistor, and the compensation switches K1 to K4 may be turned on or turned off according to a compensation multiple corresponding to one of the compensation resistors R2 to R5.
Referring to
In this embodiment, each compensation resistor corresponds to one compensation multiple. The compensation resistor corresponding to the compensation multiple is selected (i.e., a compensation switch connected in series with the compensation resistor is turned on) according to the average value of the differences in common voltage of the corresponding common electrodes 3 in the compensation region 4, to output a corresponding compensation common voltage, so that the actual common voltage of each corresponding common electrode 3 is compensated.
Specifically, after the average value of the differences in common voltage of the corresponding common electrodes 3 of a certain compensation region 4 is calculated, a timing controller controls the second terminal of the amplifier and the compensation switches according to a compensation multiple table stored in advance. For example, the compensation multiple table may be set as follows: when the pulled amplitude of the average value of the differences in common voltage is 0 to 50 mV, the compensation multiple is 5; when the pulled amplitude of the average value of the differences in common voltage is 50 mV to 100 mV, the compensation multiple is 10, and so on, but the compensation multiples are not limited thereto. The compensation multiple table may be set based on the actual conditions of the display panel, and detailed description thereof is omitted herein. It can be understood that, according to the actual conditions of each compensation region 4, the compensation multiple of each compensation region 4 may be different, that is, the output compensation common voltage is different.
For example, in the present embodiment, R1=5KΩ, R2=10KΩ, R3=15KΩ, R4=20KΩ, and R5=25KΩ (assuming that the display panel reaches a saturation state when the display panel is compensated by 25 times), wherein the compensation switches K1 to K4 are controlled by the timing controller. When the average value (of the difference ΔV between the actual common voltage and the preset common voltage) of each region is 0 to 50 mV, the timing controller controls K1 to be turned on and K2 to K4 to be in an OFF state. At this time, the amplifier outputs a compensation multiple of 5. The compensation common voltage is input into the compensation region 4 through a common electrode line in periphery of the compensation region 4, so as to achieve the purpose of compensating the common electrode 3 in the compensation region 4, and reduce the pulled amplitude of common voltage of each pixel unit in the compensation region 4. When the average value of the difference ΔV in the compensation region 4 is between 50 mV to 100 mV, the timing controller controls K2 to be turned on, and other switches to be in an OFF state, the amplifier outputs the compensation multiple of 10. Similarly, the compensation switches K3 and K4 may be controlled by the timing controller, and detailed description thereof is omitted herein.
It should be noted that monitoring the pulled amplitude of each of the common electrodes 3 inside the display panel by the timing controller begins from a first frame of display screen, but compensating each of the common electrodes 3 of the display panel begins from a second frame of display screen. Monitoring the pulled amplitude of each of the common electrodes 3 of the display panel in real time by the timing controller can improve the problem of deterioration of display effect due to long-term use of the display panel.
In the display panel of the present embodiment, by performing region division on the display panel, real-time monitoring the pulled amplitude of the common voltage VCOM of each common electrode in each compensation region, and compensating the common voltage VCOM of each common electrode in each compensation region, the pulled amplitude of the common voltage VCOM of each common electrode in each compensation region can be reduced, so that the middle region of the display panel can also be compensated, thereby effectively improving the greenish phenomenon and the line afterimage phenomenon during the display process of the display panel.
Referring
In step S1, an actual common voltage of each common electrode in each compensation region is compensated, according to an average value of differences between the actual common voltages and preset common voltages of the common electrodes in each compensation region.
Specifically, the step S1 includes a step 11, a step 12 and a step 13.
In step S11, the actual common voltage of each of the common electrodes corresponding to each compensation region is obtained.
Specifically, the step 11 may include a step 111 and a step S112.
In step S111, a pixel voltage of each of a plurality of pixel units in the compensation region is detected.
In step S112, the actual common voltage of each of the common electrodes in the compensation region is calculated based on the pixel voltage.
In step S12, an average value of differences in common voltage of the corresponding common electrodes in each compensation region is calculated according to the actual common voltage and the preset common voltage of each common electrode.
That is, the average of the differences in common voltage=Σ(the actual common voltage−the preset common voltage)/a number of the common electrodes.
In step S13, the actual common voltage of each common electrode in each compensation region is compensated according to the average value of the differences in common voltage of the common electrodes in each compensation region.
Further, the compensation sub-circuit includes a plurality of compensation resistors.
Specifically, the step S13 may include: compensating the actual common voltage of each common electrode in each compensation region by selecting one of the plurality of compensation resistors that corresponds to one of compensation multiples which are stored in advance, according to the average value of the differences in common voltage of a plurality of common electrodes in each compensation region and the compensation multiples.
The method for compensating the common voltage of the display panel may be applied to compensating the common voltage of the display panel of the first embodiment. For detailed description, reference may be made to the display panel of the first embodiment, and details will not be described herein again.
With reference to the structural diagrams of the compensation circuit shown in
First, the pixel voltage in each pixel unit in a compensation region is detected, and the actual common voltage of each common electrode in the compensation region is calculated according to the pixel voltage, output to the actual common voltage terminal (Vcom actual), and input to the negative electrode of the amplifier finally.
And then, the preset common voltage of each common electrode is input to the positive electrode of the amplifier via the preset common voltage terminal (Vcom preset). The amplifier calculates the difference in common voltage of each common electrode, and calculates the average value of the differences in common voltage of the corresponding common electrodes in the compensation region according to the difference in common voltage of each common electrode.
Finally, the actual common voltage of each common electrode in each compensation region is compensated by the following steps: by selecting one of the plurality of compensation resistors that corresponds to one of compensation multiples which are stored in advance, according to the average value of the differences in common voltage of the plurality of common electrodes in each compensation region and the compensation multiples, so as to generate the compensation common voltage; and by inputting the compensation common voltage to each common electrode in the compensation region via the compensation common voltage terminal (Vcom compensation). For example, a compensation multiple table may be set as follows: when the pulled amplitude of an average value of differences in common voltage is 0 to 50 mV, the compensation multiple is 5. When the pulled amplitude of the average value of differences in common voltage is 50 mV to 100 mV, the compensation multiple is 10, and so on. When the average value of the differences between the actual common voltages and the corresponding preset common voltages in the compensation region is between 0 and 50 mV, the timing controller controls K1 to be turned on, and controls K2 to K4 to be turned off. In this case, the output compensation multiple of the amplifier is 5.
In the method for compensating the common voltage of the display panel according to the present embodiment, by performing region division on the display panel, real-time monitoring the pulled amplitude of the common voltage VCOM of each common electrode in each compensation region, and compensating the common voltage VCOM of each common electrode in each compensation region, the pulled amplitude of the common voltage VCOM of each common electrode in each compensation region can be reduced, so that the middle region of the display panel can also be compensated, thereby effectively improving the greenish phenomenon and the line afterimage phenomenon during the display process of the display panel.
According to an embodiment, a display device including the display panel of the first embodiment is provided. The display device may be any product or component having a display function, such as a liquid crystal display panel, an electronic paper, a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, a navigator, and the like.
In the display device of the present embodiment, by performing region division on the display panel, real-time monitoring the pulled amplitude of the common voltage VCOM of each common electrode in each compensation region, and compensating the common voltage VCOM of each common electrode in each compensation region, the pulled amplitude of the common voltage VCOM of each common electrode in each compensation region can be reduced, so that the middle region of the display panel can also be compensated, thereby effectively improving the greenish phenomenon and the line afterimage phenomenon during the display process of the display panel.
It should be understood that the above implementations are merely exemplary embodiments for the purpose of illustrating the principles of the present disclosure, however, the present disclosure is not limited thereto. It will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and essence of the present disclosure, which are also to be regarded as falling into the scope of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2017 1 0002188 | Jan 2017 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2017/100193 | 9/1/2017 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2018/126721 | 7/12/2018 | WO | A |
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| Number | Date | Country | |
|---|---|---|---|
| 20190080663 A1 | Mar 2019 | US |
