CN109616055B - Display panel driving method and device and display device - Google Patents

The application relates to a display panel driving method and device and a display device. The driving method of the display panel is used for improving the gray scale precision of the display panel, and comprises the following steps: outputting two scanning signals in each sub-time unit, wherein the time required for completing the graphic display of one frame consists of more than two sub-time units, the first scanning signal is defined as a first scanning signal, and the second scanning signal is defined as a second scanning signal; responding to the potential of the first scanning signal to enable the controlled transistor to be conducted, and inputting a first data signal which can enable the display panel to send out first preset brightness; and inputting a second data signal which can enable the display panel to send out second preset brightness in response to the fact that the potential of the second scanning signal enables the controlled transistor to be conducted. The method and the device can solve the problem that the gray scale precision is not high due to the fact that the manufacturing process difference and the voltage amplitude are not easy to control accurately, and therefore the brightness of the picture is not uniform.

Display panel driving method and device and display device

Technical Field

The present disclosure relates to the field of display technologies, and in particular, to a method and an apparatus for driving a display panel.

Background

The Organic Light Emitting Diode (OLED) can be classified into a Passive Matrix OLED (PMOLED) and an Active Matrix OLED (AMOLED) according to a driving method. The PMOLED emits light only during data writing, and does not emit light when data is not written. The driving mode has simple structure, low cost and easy design, and is mainly suitable for small and medium-sized display devices.

Current I flowing through the OLED device_oledThe magnitude of the amplitude is determined by the voltage V on the data line_dataDetermining that the higher the voltage value sent by the data line, the higher the current I_oledThe larger the current I is, the more the current I is_oledIt becomes smaller. By controlling V_dataThe amplitude value further achieves the purposes of adjusting the brightness of the OLED and controlling the gray scale. However, this method generally causes the defect of uneven brightness of the image due to the poor gray scale precision caused by the difference in the manufacturing process and the difficulty in precisely controlling the voltage amplitude, and the image cannot be precisely controlled to the required gray scale.

Disclosure of Invention

Accordingly, it is necessary to provide a driving method and device for a display panel and a display device, which are directed to the problem of uneven brightness and brightness of a picture due to low gray scale precision caused by the process variation and the difficulty in precise control of the voltage amplitude of the display panel.

A driving method of a display panel is used for improving the gray scale precision of the display panel, and is characterized by comprising the following steps:

outputting scanning signals twice in each sub-time unit, wherein the time required for completing the graphic display of one frame consists of more than two sub-time units, the first scanning signal is defined as a first scanning signal, and the second scanning signal is defined as a second scanning signal;

responding to the potential of the first scanning signal to enable the controlled transistor to be conducted, and inputting a first data signal which can enable the display panel to send out first preset brightness;

and inputting a second data signal which can enable the display panel to send out second preset brightness in response to the fact that the potential of the second scanning signal enables the controlled transistor to be conducted.

In one embodiment, the driving method of the display panel further includes:

adjusting voltage values of the first data signal and the second data signal to finely divide gray scales of the display panel.

In one embodiment, the voltage value of the first data signal is greater than the voltage value of the second data signal.

In one embodiment, the voltage value of the first data signal is smaller than the voltage value of the second data signal.

In one embodiment, the voltage value of the first data signal is equal to the voltage value of the second data signal.

In one embodiment, the potential that turns on the controlled transistor is high.

In one embodiment, the voltage value of the first data signal is 4V-10V.

A driving apparatus of a display panel, comprising:

a scanning signal output unit for outputting two scanning signals in each sub-time unit, wherein the time required for completing the graphic display of one frame is composed of more than two sub-time units, the first scanning signal is defined as a first scanning signal, and the second scanning signal is defined as a second scanning signal;

the first data signal output unit responds to the potential of the first scanning signal to enable the controlled transistor to be conducted, and inputs a first data signal which enables the display panel to send out first preset brightness;

and the second data signal output unit responds to the potential of the second scanning signal to enable the controlled transistor to be conducted, and inputs a second data signal which can enable the display panel to send out second preset brightness.

In one embodiment, the driving apparatus of the display panel further includes:

and the adjusting unit is used for adjusting the voltage values of the first data signal and the second data signal so as to finely divide the gray scale of the display panel.

A display device comprising a driving device of a display panel as described in the foregoing.

In the driving method of the display panel, the scanning signals are output twice in each sub-time unit, wherein the time required for completing the graphic display of one frame is composed of more than two sub-time units, the first scanning signal is defined as a first scanning signal, and the second scanning signal is defined as a second scanning signal; responding to the potential of a first scanning signal to enable a controlled transistor to be conducted, and inputting a first data signal which can enable a display panel to send out first preset brightness; and responding to the potential of the second scanning signal to enable the controlled transistor to be conducted, and inputting a second data signal which can enable the display panel to emit second preset brightness. The time of a frame is finely divided, then scanning signals are output twice in each sub-time unit, finally, when the potentials of the scanning signals are conducted to control transistors, data signals capable of enabling the display panel to send out first preset brightness and second preset brightness are input, through the light mixing effect of the first preset brightness and the second preset brightness on the time, the divided gray scale can be more accurate, new gray scale brightness can be generated according to adjustment of the voltage value of the data signals and the number of the sub-time units, and therefore the problem that the gray scale precision is not high and further the picture brightness is uneven due to the fact that the manufacturing process difference and the voltage amplitude are not easy to accurately control of the display panel can be solved. Further, fine division of gray scales of the display panel can be realized by adjusting voltage values of the first data signal and the second data signal.

Drawings

FIG. 1 is a flow chart illustrating a driving method of a display panel according to an embodiment;

FIG. 2 is a schematic diagram of a pixel driving circuit in an exemplary technique;

FIG. 3 is a waveform diagram of an output of a scan signal according to an embodiment;

FIG. 4 is a waveform diagram of the output of scan signals and data signals in one embodiment;

fig. 5 is a schematic structural diagram of a driving apparatus of a display panel in an embodiment.

Detailed Description

To facilitate an understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present application are given in the accompanying drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not represent the only embodiments.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

Fig. 2 is a schematic diagram of a pixel driving circuit in an exemplary technology. The pixel driving circuit adopts a 2T1C structure. Here, the 2T thin film transistor T11 and the thin film transistors T12 and T1C are the storage capacitor C1 connected across the gate and the source of the thin film transistor T12. The gate of the thin film transistor T11 is electrically connected to a Scan voltage signal Scan, the source of the thin film transistor T11 is used for receiving a Data voltage signal Data, and the drain of the thin film transistor T12 is connected to the gate of the thin film transistor T12. The source of the TFT T12 is electrically connected to a common voltage VDD, and the drain is connected to a ground voltage V via the LED_SS. The Light Emitting Diode LED may be an Organic Light Emitting Diode OLED (Organic Light Emitting Diode). When the driving light is emitted, a current flows on the VDD, and since the OLED device is an organic semiconductor and a current always flows in the display stage, the display brightness of the OLED device is reduced under the same current, and is easy to deteriorate, thereby causing abnormalities such as poor display and the like, and the picture cannot be accurately controlled to the required gray scale.

The gray scale is obtained by dividing the brightness variation between the brightest and darkest into several parts. So as to control the screen brightness corresponding to the signal input. Each digital image is composed of a plurality of dots, which are also called pixels (pixels), and each pixel can usually display a plurality of different colors, which are composed of three sub-pixels of Red (Red), Green (Green), and Blue (Blue). Each sub-pixel, the light source behind it, may exhibit a different brightness level. And the gray levels represent gradation levels of different brightness from the darkest to the brightest. The more the intermediate levels are, the more exquisite the picture effect can be presented. Taking an 8-bit display panel as an example, the display panel can represent 8 powers of 2, i.e. 256 luminance levels, i.e. 256 gray levels as is common.

Fig. 1 is a schematic flow chart illustrating a driving method of a display panel according to an embodiment. The driving method of the display panel is used for improving the gray scale precision of the display panel. The driving method of the display panel may include the steps of: S100-S300.

Step S100, outputting two scanning signals in each sub-time unit, wherein the time required for completing the graphic display of one frame is composed of more than two sub-time units, the first scanning signal is defined as a first scanning signal, and the second scanning signal is defined as a second scanning signal.

The display panel may be, for example, an organic light emitting display panel, that is, an OLED display panel, and is different from a liquid crystal display panel in that a middle liquid crystal layer is omitted, but a main driving manner is to turn on scan signals line by line, and then data signals are input in each line, that is, each scan signal in fig. 3 is turned on at a falling edge of a previous scan signal. Generally, the scan signal Gi is input row by row, i.e., G1 to Gm are sequentially input high level at a fixed period, so that the data signal is input for the row. When the input of the scanning signal is finished, the display of one frame of graphics is finished. Typically, the one-frame scan time is 1/60 second, i.e., the refresh rate is 60 Hz. The scanning time of 1/60 second is the time unit required for completing one frame of graphic display. In this embodiment, the time unit may be split into two or more sub-time units, where the time unit may be split into equal parts or not. Illustratively, taking the splitting into three sub-time units as an example, that is, splitting a time unit into three sub-time units, each sub-time unit is 1/180 second since one time unit is 1/60 second. It is understood that the specific number of splits for a sub-time unit can be selected and adjusted according to the actual needs and product performance of those skilled in the art, and is not further limited herein.

Further, after the time unit required for completing the display of one frame of image is divided into more than two sub-time units, two scanning signals, that is, scanning driving voltage signals, may be output in each sub-time unit, and the scanning driving voltage signals are mainly used for controlling the gate lines to be turned on or turned off. For convenience of description and distinction, the first scan signal is defined as a first scan signal, and the second scan signal is defined as a second scan signal.

Step S200, in response to the potential of the first scan signal turning on the controlled transistor, inputting a first data signal that enables the display panel to emit a first preset brightness.

Specifically, the transistor to be controlled is turned on in response to the potential of the first scan signal, and the transistor may be, for example, a thin film transistor and a field effect transistor, exemplified by a thin film transistor. In response to the potential of the first scan signal being high, the thin film transistor is turned on, in other words, only when the potential of the first scan signal is high, the thin film transistor receives the high level and is turned on, and then a first data signal capable of making the display panel emit a first preset brightness is input. The first preset brightness may also be referred to as gray scale brightness, wherein a specific value of the first preset brightness may be selected and adjusted according to a voltage value of the first data signal and a requirement of the display panel for gray scale precision. Further, taking the gray scale value as 8 bits (0-255 gray scales) as an example, the gray scale brightness of the display panel can be calculated by the following formula:

wherein, A represents the gray level value, B represents the gray level value brightness, namely the normalized brightness, the two accord with the relation of exponential power 2.2, and the gray level value brightness required to be obtained can be determined by looking up the table or according to the formula.

Step S300, in response to the potential of the second scan signal turning on the controlled transistor, inputting a second data signal that enables the display panel to emit a second preset brightness.

Specifically, the transistor controlled in response to the potential of the second scan signal is turned on, and the transistor may be, for example, a thin film transistor and a field effect transistor, exemplified by a thin film transistor. In response to the second scan signal, the thin film transistor is turned on, in other words, the thin film transistor receives the high level conduction only when the second scan signal is at the high level, and then the second data signal which can make the display panel emit the second preset brightness is input. The second preset brightness may also be referred to as gray scale brightness, wherein a specific value of the second preset brightness may be selected and adjusted according to a voltage value of the second data signal and a requirement of the display panel for gray scale precision. Further, taking the gray scale value as 8 bits (0-255 gray scales) as an example, the gray scale brightness of the display panel can be calculated by the following formula:

wherein, A represents the gray level value, B represents the gray level value brightness, namely the normalized brightness, the two accord with the relation of exponential power 2.2, and the gray level value brightness required to be obtained can be determined by looking up the table or according to the formula.

In one embodiment, the gray scale luminance of the display panel is determined by the voltage value of the data signal. In this embodiment, the voltage value of the first data signal may be 4V-10V. Alternatively, the voltage value of the first data signal may be 4V-6V; alternatively, the voltage value of the first data signal may be 6V-8V; alternatively, the voltage value of the first data signal may be 8V-10V. The voltage value of the second data signal can also be 4V-10V. Alternatively, the voltage value of the second data signal may be 4V-6V; alternatively, the voltage value of the second data signal may be 6V-8V; alternatively, the voltage value of the second data signal may be 8V-10V. In this embodiment, a voltage value of the first data signal for enabling the display panel to emit the first preset brightness and a voltage value of the second data signal for enabling the display panel to emit the second preset brightness may be the same, in other words, the first preset brightness and the second preset brightness are the same. For example, the voltage value of the first data signal and the voltage value of the second data signal are both 8V.

In one embodiment, the gray scale luminance of the display panel is determined by the voltage value of the data signal. In this embodiment, the voltage value of the first data signal for causing the display panel to emit the first preset brightness is different from the voltage value of the second data signal for causing the display panel to emit the second preset brightness, for example, please refer to fig. 4, in one sub-time unit, the Gate is turned on twice, which are g1 (the first scan signal) and g2 (the second scan signal), respectively, and correspondingly outputs two data signals (the first data signal d1 and the second data signal d2), as shown in the figure, the voltage value of the first data signal d1 is greater than the voltage value of the second data signal d2, in other words, the value of the first preset brightness is greater than the value of the second preset brightness, and from the display perspective, the first preset brightness is relatively brighter than the second preset brightness.

In one embodiment, the gray scale luminance of the display panel is determined by the voltage value of the data signal. In this embodiment, the voltage value of the first data signal for enabling the display panel to emit the first preset brightness is different from the voltage value of the second data signal for enabling the display panel to emit the second preset brightness.

Since the human eye senses the brightness at a frequency of about 30Hz, the human eye senses the brightness as an average value within 30Hz when the frequency is higher than 30Hz, and does not sense the brightness difference generated when the frequency is higher than 30Hz, which is also called a light mixing effect. That is, generally, human eyes feel the integrated brightness of the display panel within one frame time, taking three sub-time units as an example, each sub-time unit has two gray-scale brightness (display brightness), and each of the three sub-time units has six gray-scale brightness, which are respectively represented by L1, L2, L3, L4, L5, and L6, and finally, the brightness presented within one frame time is the integrated brightness of L1, L2, L3, L4, L5, and L6, and each gray-scale brightness can be adjusted, so that the split gray scale can be more accurate, and the phenomenon of uneven brightness of the picture can be improved.

In the driving method of the display panel, the scanning signals are output twice in each sub-time unit, wherein the time required for completing the graphic display of one frame is composed of more than two sub-time units, the first scanning signal is defined as a first scanning signal, and the second scanning signal is defined as a second scanning signal; responding to the potential of a first scanning signal to enable a controlled transistor to be conducted, and inputting a first data signal which can enable a display panel to send out first preset brightness; and responding to the potential of the second scanning signal to enable the controlled transistor to be conducted, and inputting a second data signal which can enable the display panel to emit second preset brightness. The time of a frame is finely divided, then scanning signals are output twice in each sub-time unit, finally, when the potentials of the scanning signals are conducted to control transistors, data signals capable of enabling the display panel to send out first preset brightness and second preset brightness are input, through the light mixing effect of the first preset brightness and the second preset brightness on the time, the divided gray scale can be more accurate, new gray scale brightness can be generated according to adjustment of the voltage value of the data signals and the number of the sub-time units, and therefore the problem that the gray scale precision is not high and further the picture brightness is uneven due to the fact that the manufacturing process difference and the voltage amplitude are not easy to accurately control of the display panel can be solved.

In one embodiment, the driving method of the display panel may further include the steps of:

adjusting voltage values of the first data signal and the second data signal to finely divide gray scales of the display panel.

Specifically, the magnitude of the gray-scale luminance of the display panel mainly depends on the voltage value of the data signal. Therefore, when the gray scale of the display panel is required to be divided, the gray scale brightness can be adjusted by adjusting the voltage values of the first data signal and the second data signal, and the gray scale of the display panel is further finely divided.

According to the driving device of the display panel, the scanning signal output unit is arranged to output the scanning signals twice in each sub-time unit, the first data signal output unit and the second data signal output unit are respectively input to enable the display panel to send out the data signals of the first preset brightness and the second preset brightness when the potentials of the scanning signals twice are conducted to enable the controlled transistor, the split gray scale can be more accurate through the light mixing effect of the first preset brightness and the second preset brightness, and the new gray scale brightness can be generated according to the adjustment of the voltage value of the data signals and the number of the sub-time units, so that the problem that the gray scale precision is not high and further the picture brightness is not uniform due to the fact that the manufacturing process difference and the voltage amplitude are not easy to accurately control of the display panel can be solved.

In one embodiment, the driving apparatus of the display panel may further include:

and the adjusting unit is used for adjusting the voltage values of the first data signal and the second data signal so as to finely divide the gray scale of the display panel.

Specifically, the magnitude of the gray-scale luminance of the display panel mainly depends on the voltage value of the data signal. Therefore, when the gray scale of the display panel is required to be divided, the gray scale brightness can be adjusted by adjusting the voltage values of the first data signal and the second data signal, and the gray scale of the display panel is further finely divided.

A display device can comprise the display panel driving device, the display panel driving device outputs twice scanning signals in each sub-time unit by arranging a scanning signal output unit, a first data signal output unit and a second data signal output unit respectively input data signals which can enable the display panel to send out a first preset brightness and a second preset brightness when the potentials of the twice scanning signals are conducted by a controlled transistor, the split gray scale can be more accurate through the light mixing effect of the first preset brightness and the second preset brightness, and can generate new gray-scale brightness according to the adjustment of the voltage value of the data signal and the number of the sub-time units, therefore, the problem that the gray scale precision is not high and the brightness of the picture is not uniform due to the manufacturing process difference and the voltage amplitude which are not easy to control accurately of the display panel can be solved.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.