TW202219931A - Pixel leakage current compensation method of OLED display, OLED display and information processing device enabling the sub-pixel of the OLED to maintain a stable brightness when displaying each frame of image, and make sure of no screen flickering in the display - Google Patents

Abstract

Disclosed is a pixel leakage current compensation method of an OLED display, which is applied in a display driver chip, so that the driver chip is able to execute pixel leakage current compensation at the time when driving an OLED display panel to display consecutively K+1 frames during a showing data process. More specifically, when generating pixel light emitting control signals (EM signals), the method adjusts a low level pulse width of a pixel light emitting control signals within a screen cycle of each frame showing data correspondingly based on the plurality of OLED sub-pixel leakage currents, so that the display driver chip is able to use EM signals to adjust brightness of the OLED display panel, and also complete the pixel leakage current compensation at the same time. Accordingly, the method enables a sub-pixel of the OLED to maintain a stable brightness when displaying each frame of image, and makes sure of no screen flickering in the display.

Description

Pixel leakage current compensation method of OLED display panel, OLED display, and information processing device

The present invention relates to the technical field of OLED displays, and more particularly, to a pixel leakage current compensation method of an OLED display panel, which utilizes a pixel luminescence control signal (EM signal) to adjust pixel brightness changes caused by OLED leakage.

It is known that flat-panel displays include non-self-luminous flat-panel displays and self-luminous flat-panel displays. Liquid crystal displays are a non-self-luminous flat-panel display that has been used for a long time, and organic light-emitting diodes (OLEDs) ) display is a self-luminous flat panel display that is widely used at present. Compared with liquid crystal displays, OLED displays have many advantages, including: high contrast ratio, ultra-thin, flexible and so on.

FIG. 1 shows a block diagram of a conventional OLED display. As shown in FIG. 1, the OLED display 1a includes: an OLED display panel 11a, a gate driver circuit 12a, a source driver circuit 13a, and a display controller 14a; wherein, the OLED display panel 11a includes: N× M OLED sub-pixels 111a, N×M pixel circuit units 112a, M source driving lines 11Sa, and N gate driving lines 11Ga. In more detail, each gate driving line 11Ga is coupled to the M pixel circuit units 112a along a first direction, and each source driving line 11Sa is along a first direction orthogonal to the first direction. The N pixel circuit units 112a are coupled in two directions. In more detail, each of the pixel circuit units 112a is coupled to a scan signal Scan(n) and a pixel emission control signal EM(n) transmitted from the gate driving circuit 12a.

Taking the skip frame display driving technology as an example, the display driving chip (including the gate driving circuit 12a and the source driving circuit 13a) drives the OLED display panel 11a to refresh one frame of display data, and then skips K frames of display. After the data, the OLED display panel 11a is driven to refresh the display data of the K+1th frame. To put it simply, the display driving chip K+1 frame is one cycle of driving the OLED display panel 11a to perform image display.

FIG. 2 is a timing chart showing the operation of a conventional vertical synchronization signal and a pixel lighting control signal. Electronic engineers who are familiar with the design and manufacture of OLED displays know that in the design of the OLED display 1a, the OLED sub-pixel 111a is usually adjusted in one frame by changing the duty ratio of the pixel light-emitting control signal EM(n). The light-emitting time in the cycle, and then realize the adjustment of the screen brightness. However, as shown in FIG. 2 , the pixel lighting control signals EM used in the K+1 frame picture period in the prior art all have the same duty cycle. It must be emphasized that, as shown in FIG. 1 , process errors may cause each OLED sub-pixel 111a to have different leakage currents. Therefore, if the leakage current is not properly compensated, all the pixel emission control signals EM(n) have the same duty cycle, which will cause the OLED display 1a to display the K+1 frames during the process of displaying the picture. Flickering on the display screen occurs.

It can be seen from the above description that there is an urgent need in the art for a new method for compensating pixel leakage current of an OLED display panel.

The main purpose of the present invention is to provide a pixel leakage current compensation method of an OLED display panel, which is applied to a display driver chip, so that the display driver chip can simultaneously execute the process of driving an OLED display panel to continuously display a plurality of frames of images. Pixel leakage current compensation, so that the OLED display panel can display each frame of image under the condition that the brightness of the OLED pixel remains stable, ensuring that there will be no flickering of the display screen.

In order to achieve the above object, the present invention proposes an embodiment of the pixel leakage current compensation method of the OLED display panel, which is applied in an OLED display including at least one display driver chip and an OLED display panel; wherein, the OLED The display panel includes N×M OLED sub-pixels, N×M pixel circuit units, M source drive lines, and N gate drive lines, where N and M are both positive integers, and the pixel drains The current compensation method includes the following steps:

generating N pixel light-emitting control signals for transmitting to the N×M pixel circuit units according to the K+1 frame display data; and

According to the leakage current of the N×M OLED sub-pixels, a low-level width setting is performed on the pixel light-emitting control signal transmitted to the gate driving line of the nth row, so that the pixel light-emitting control signal is The picture period of the frame display data has the same T signal periods, and the low-level width of the pixel light-emitting control signal corresponding to the kth frame display data is the same or different from that corresponding to the k+1th frame display data. The low-level width of the pixel light-emitting control signal; wherein, 1≦n≦N, 1≦k≦K, and T is a positive integer.

In one embodiment, in a leakage current measurement mode, the first leakage current of one of the N×M OLED sub-pixels is measured from the picture period of the kth frame of display data, and the first leakage current of one of the N×M OLED sub-pixels is measured from the kth frame of display data. A second leakage current of one of the N×M OLED sub-pixels is measured in a frame period, and there is a first proportional value between the first leakage current and the first and second leakage currents.

In one embodiment, after the low-level width setting is completed, the pixel light-emitting control signal has a first low-level width in the picture period of the kth frame of display data, and is displayed in the k+1th frame. There is a second low level width in the picture period of the data; wherein, there is a second proportional value between the first low level width and the second low level width, and the second proportional value is equal to the first A proportional value, or a proportional relationship with the first proportional value.

In one embodiment, the display driver chip includes a register for registering the T low voltages included in the T signal periods of the pixel light-emitting control signal in the picture period of each frame of display data. flat width, so as to facilitate the completion of the low level width setting.

The present invention also provides an OLED display, which includes at least one display driver chip and an OLED display panel, and the OLED display panel includes N×M OLED sub-pixels, N×M pixel circuit units, and M source drivers. line, and N gate driving lines; wherein, N and M are both positive integers, and the display driving chip has a compensation unit for executing a pixel leakage current compensation method; the pixel leakage current compensation method includes the following step:

generating N pixel light-emitting control signals for transmitting to the N×M pixel circuit units according to the K+1 frame display data; and

According to the leakage current of the N×M OLED sub-pixels, a low-level width setting is performed on the pixel light-emitting control signal EM transmitted to the gate driving line of the n-th row, so that the pixel light-emitting control signal is in each A frame of display data has the same T signal periods in the picture period, and the low-level width of the pixel luminescence control signal EM corresponding to the kth frame of display data is the same or different from that of the k+1th frame of display data The low-level width of the pixel light-emitting control signal; wherein, 1≦n≦N, 1≦k≦K, and T is a positive integer.

In one embodiment, in a leakage current measurement mode, in a leakage current measurement mode, the first leakage current of one of the N×M OLED sub-pixels is measured from the picture period of the kth frame of display data , the second leakage current of one of the N×M OLED sub-pixels is measured during the picture period of the kth frame of display data, and there is a first ratio between the first leakage current and the first and second leakage currents numerical value.

In one embodiment, after the low-level width setting is completed, the pixel light-emitting control signal has a first low-level width in the picture period of the kth frame of display data, and is displayed in the k+1th frame. There is a second low level width in the picture period of the data; wherein, there is a second proportional value between the first low level width and the second low level width, and the second proportional value is equal to the first A proportional value, or a proportional relationship with the first proportional value.

In one embodiment, the display driver chip includes a register for registering the T low voltages included in the T signal periods of the pixel light-emitting control signal in the picture period of each frame of display data. flat width, so as to facilitate the completion of the low level width setting.

The present invention also provides an information processing device having the OLED display of the present invention as described above.

In one embodiment, the information processing device is an electronic device selected from the group consisting of a smart phone, a smart watch, a smart bracelet, a tablet computer, a notebook computer, an all-in-one computer, and an access control device.

In order to enable your examiners to further understand the structure, characteristics, purpose, and advantages of the present invention, drawings and detailed descriptions of preferred embodiments are attached as follows.

The present invention mainly discloses a pixel leakage current compensation method of an OLED display panel, which is applied to a display driver chip, so that the display driver chip drives an OLED display panel to display continuously according to a skip frame display driving mode Pixel leakage current compensation is performed at the same time in the process of displaying data in the K+1 frame. The specific implementation method is to make the display driver chip correspondingly adjust the pixel light-emitting control signal according to the leakage current of a plurality of OLED sub-pixels in the process of generating the pixel light-emitting control signal (EM signal) to display each frame. The low level width in the picture period of the data enables the display driver chip to complete pixel leakage current compensation at the same time when using the EM signal to adjust the brightness of the OLED display panel, so that the OLED display panel can be used in the OLED sub-picture. Each frame of image is displayed under the condition that the pixel brightness remains stable, to ensure that there will be no flickering of the display screen.

FIG. 3 shows a block diagram of an OLED display to which a pixel leakage current compensation method of an OLED display panel of the present invention is applied. As shown in FIG. 3, the OLED display 1 includes: an OLED display panel 11, a gate driver circuit 12, a source driver circuit 13, and a display controller 14, wherein the gate driver circuit 12 and the source electrode The driving circuit 13 can be integrated into a single display driving chip. Furthermore, it can be seen from FIG. 3 that the OLED display panel 11 includes: N×M OLED sub-pixels 111 , N×M pixel circuit units 112 , M source driving lines 11S, and N gate driving lines 11G. In more detail, each gate driving line 11G is coupled to the M pixel circuit units 112 along a first direction, and each source driving line 11S is along a mutually orthogonal to the first direction. The N pixel circuit units 112 are coupled in the second direction. In more detail, each of the pixel circuit units 112 is simultaneously coupled to a scan signal Scan(n) and a pixel emission control signal EM(n) transmitted from the gate driving circuit 12 .

FIG. 4 shows a flow chart of a pixel leakage current compensation method of an OLED display panel according to the present invention. It should be added that, before starting to perform pixel leakage current compensation, the OLED display 1 must be operated in a leakage current measurement mode, so that the display driving chip drives the OLED display in a frame-skipping display driving mode. When the panel 11 continuously displays the K+1 frames of display data, the leakage currents of the N×M OLED sub-pixels 111 are measured within the picture period of each frame of display data. For example, the first leakage current of one of the N×M OLED sub-pixels 111 is measured from the frame period of the kth frame of display data, and N×M is measured from the frame period of the kth frame of display data A second leakage current of each of the OLED sub-pixels 111; wherein, 1≦k≦K, and there is a first proportional value between the first leakage current and the first and second leakage currents. In other words, the two sets of leakage current data measured in the picture period of two adjacent frames of display data have a proportional value.

As shown in FIG. 3 and FIG. 4 , the pixel leakage current compensation method of the OLED display panel of the present invention first performs step S1 : generating according to K+1 frame display data for transmission to the N×M pixel circuit units 112 The N pixel light-emitting control signals EM(1~n). Next, the method flow continues to perform step S2: according to the leakage current of the N×M OLED sub-pixels 111, a low-level width is performed on the pixel emission control signal EM transmitted to the gate driving line 11G of the nth row. It is set so that the pixel light-emitting control signal EM has the same T signal periods in the picture period of each frame of display data, and corresponds to the low-level width of the pixel light-emitting control signal EM of the kth frame of display data The same or different from the low level width of the pixel emitting control signal EM corresponding to the k+1th frame of display data; wherein 1≦n≦N, 1≦k≦K, and T is a positive integer.

FIG. 5 shows the operation timing diagram of the vertical synchronization signal and the pixel light-emitting control signal of the present invention. As shown in FIG. 5 , after the low-level width setting is completed through the aforementioned step S2, in the picture period of each frame of the k+1 frames of display data, the pixel light-emitting control signals EM all have the same T For example, FIG. 5 shows that the pixel light-emitting control signal EM has 2 signal periods. It should be understood that two signal periods indicate that the pixel light-emitting control signal EM includes two low-level widths in a picture period of one frame of display data.

In more detail, FIG. 5 exemplarily shows that the pixel light-emitting control signal EM includes two first low-level widths (ie, W1 and W1) in the picture period of the first frame of display data, and these two The low level width is the same. However, the pixel light emission control signal EM includes two second low level widths (ie, W2 and W2) in the picture period of the second frame display data (frame skipping is not displayed), but the second low level The width is not equal to the width of the first low level. Further, the pixel light-emitting control signal EM includes two third low level widths (ie, W3 and W3) in the picture period of the third frame display data (frame skipping is not displayed), but the third low level width is The level width is not equal to the second low level width. It can be found that the width of the third low level is larger than the width of the second low level. It should be understood that the reason for setting the width of the third low level wider is to display the data in the third frame (frame skipping and not displaying) The picture period The light emission brightness of the OLED sub-pixel 111a is dimmed a little.

Of course, the setting of the width of the aforementioned low-level width depends on the leakage current measured from the OLED sub-pixel 111a. Therefore, in the leakage current measurement mode, the first leakage current of one of the N×M OLED sub-pixels 111 is measured from the picture period of the k-th frame of display data, and the first leakage current of one of the N×M OLED sub-pixels 111 is measured from the k-th frame of display data within the picture period of the k-th frame of data. A second leakage current of one of the N×M OLED sub-pixels 111 is measured, and there is a first proportional value between the first leakage current and the first and second leakage currents. Correspondingly, after completing the low-level width setting, the pixel light-emitting control signal EM has a first low-level width within the picture period of the kth frame of display data, and the pixel light-emitting control signal EM has the first low level width within the picture period of the k+1th frame of display data. has a second low-level width; wherein, there is a second proportional value between the first low-level width and the second low-level width, and the second proportional value will be equal to the first proportional value, or There is a proportional relationship with the first proportional value.

It is added that in practical applications, a register can be set on the display driver chip for registering the T values included in the T signal periods of the pixel light-emitting control signal EM in the picture period of each frame of display data. The width of the low level is set so that the display driving chip can quickly complete the setting of the low level width by accessing the register.

It should be understood that after applying the method of the present invention, the display driving chip (including the gate driving circuit 12 and the source driving circuit 13 ) can automatically generate the pixel light emission control signal EM according to a plurality of OLED sub-pictures. The leakage current of the pixel 111a is adjusted accordingly to adjust the low level width of the pixel luminescence control signal (EM signal) in the picture period of each frame of display data, so that the display driving chip uses the EM signal to adjust the brightness of the OLED display panel 11. At the same time, the pixel leakage current compensation can also be completed at the same time, so that the OLED display panel 11 can display each frame of images while the brightness of the OLED sub-pixels 111 is kept stable, ensuring that there will be no flickering of the display screen. .

In this way, the above has completely and clearly described a pixel leakage current compensation method for an OLED display panel of the present invention; and, from the above, it can be known that the present invention has the following advantages:

(1) The present invention discloses a pixel leakage current compensation method of an OLED display panel, which is applied to a display driver chip, so that the display driver chip can simultaneously perform the drawing during the process of driving an OLED display panel to continuously display a plurality of frames of images. Pixel leakage current compensation, so that the OLED display panel can display each frame of image under the condition that the brightness of the OLED pixel remains stable, ensuring that there will be no flickering of the display screen.

(2) The present invention also provides an OLED display, which includes at least a display driver chip and an OLED display panel, and the display driver chip has a compensation unit for performing the pixel leakage current compensation of the OLED display panel of the present invention. method.

(3) The present invention also provides an information processing device having the OLED display of the present invention as described above. Moreover, the information processing device is an electronic device selected from the group consisting of smart phones, smart watches, smart bracelets, tablet computers, notebook computers, all-in-one computers, and access control devices.

It must be emphasized that the above-mentioned disclosure in this case is a preferred embodiment, and any partial changes or modifications originating from the technical ideas of this case and easily inferred by those who are familiar with the art are within the scope of the patent of this case. category of rights.

To sum up, regardless of the purpose, means and effect of this case, it shows that it is completely different from the conventional technology, and its first invention is suitable for practical use, and it does meet the requirements of a patent for invention. Society is to pray for the best.

1a: OLED display 11a: OLED display panel 111a: OLED sub-pixel 112a: pixel circuit unit 11Sa: source drive line 11Ga: gate drive line 1: OLED display 11: OLED display panel 111: OLED sub-pixel 112: Pixel circuit unit 11S: source drive line 11G: Gate drive line S1: Generate N pixel light-emitting control signals for transmitting to the N×M pixel circuit units according to the K+1 frame display data S2: According to the leakage current of the N×M OLED sub-pixels, perform a low-level width setting on the pixel light-emitting control signal transmitted to the gate driving line of the nth row, so that the pixel light-emitting control signal is in each The picture period of the frame display data has the same T signal periods, and the low-level width of the pixel light-emitting control signal corresponding to the kth frame display data is the same or different from that corresponding to the k+1th frame display data. the low level width of the pixel light emission control signal

1 is a block diagram of a conventional OLED display; FIG. 2 is a conventional working timing diagram of a vertical synchronization signal and a pixel light-emitting control signal; 3 is a block diagram of an OLED display to which a pixel leakage current compensation method of an OLED display panel of the present invention is applied; 4 is a flowchart of a pixel leakage current compensation method for an OLED display panel according to the present invention; and FIG. 5 is a timing diagram of the operation of the vertical synchronization signal and the pixel light-emitting control signal of the present invention.

S1: Generate N pixel light-emitting control signals for transmitting to the N×M pixel circuit units according to the K+1 frame display data

S2: According to the leakage current of the N×M OLED sub-pixels, perform a low-level width setting on the pixel light-emitting control signal transmitted to the gate driving line of the nth row, so that the pixel light-emitting control signal is in each The picture period of the frame display data has the same T signal periods, and the low-level width of the pixel light-emitting control signal corresponding to the kth frame display data is the same or different from that corresponding to the k+1th frame display data. the low level width of the pixel light emission control signal

Claims (10)

A pixel leakage current compensation method for an OLED display panel, which is applied in an OLED display including at least one display driver chip and an OLED display panel; wherein, the OLED display panel includes N×M OLED sub-pixels, N ×M pixel circuit units, M source driving lines, and N gate driving lines, N and M are both positive integers, and the pixel leakage current compensation method includes the following steps: generating N pixel light-emitting control signals for transmitting to the N×M pixel circuit units according to the K+1 frame display data; and According to the leakage current of the N×M OLED sub-pixels, a low-level width setting is performed on the pixel light-emitting control signal EM transmitted to the gate driving line of the n-th row, so that the pixel light-emitting control signal is in each The picture period of one frame of display data has the same T signal periods, and the low-level width of the pixel light-emitting control signal corresponding to the kth frame of display data is the same or different from that of the k+1th frame of display data. The low-level width of the pixel light-emitting control signal; wherein, 1≦n≦N, 1≦k≦K, and T is a positive integer. The pixel leakage current compensation method of an OLED display panel according to claim 1, wherein, in a leakage current measurement mode, N×M of the OLED sub-pixels are measured from the picture period of the kth frame of display data. A first leakage current, a second leakage current of the N×M OLED sub-pixels is measured from the picture period of the kth frame of display data, and the difference between the first leakage current and the first and second leakage currents The interval has a first proportional value. The pixel leakage current compensation method for an OLED display panel according to claim 2, wherein after the low level width setting is completed, the pixel light-emitting control signal has a first value in the picture period of the kth frame of display data. a low level width, and has a second low level width in the picture period of the k+1th frame display data; wherein, there is a first low level width between the first low level width and the second low level width Two proportional values, and the second proportional value is equal to the first proportional value, or has a proportional relationship with the first proportional value. The pixel leakage current compensation method for an OLED display panel according to claim 2, wherein the display driver chip includes a register for registering the T of the pixel light-emitting control signal within the picture period of each frame of display data. The T low-level widths included in each of the signal periods are used to facilitate the completion of the low-level width setting. An OLED display includes at least one display driver chip and an OLED display panel, and the OLED display panel includes N×M OLED sub-pixels, N×M pixel circuit units, M source drive lines, and N A gate driving line; wherein, N and M are both positive integers, and the display driving chip has a compensation unit for executing a pixel leakage current compensation method; the pixel leakage current compensation method includes the following steps: generating N pixel light-emitting control signals for transmitting to the N×M pixel circuit units according to the K+1 frame display data; and According to the leakage current of the N×M OLED sub-pixels, a low-level width setting is performed on the pixel light-emitting control signal EM transmitted to the gate driving line of the n-th row, so that the pixel light-emitting control signal is in each The picture period of one frame of display data has the same T signal periods, and the low-level width of the pixel light-emitting control signal corresponding to the k-th frame of display data is the same or different from that corresponding to the k+1-th frame of display data. The low-level width of the pixel light-emitting control signal; wherein, 1≦n≦N, 1≦k≦K, and T is a positive integer. The OLED display of claim 5, wherein, in a leakage current measurement mode, the first leakage current of one of the N×M OLED sub-pixels is measured during the picture period of the kth frame of display data, and the The second leakage current of one of the N×M OLED sub-pixels is measured in the picture period of the kth frame of display data, and the first leakage current and the first and second leakage currents have a first proportional value. The OLED display of claim 6, wherein after the low-level width setting is completed, the pixel light-emitting control signal has a first low-level width within the picture period of the kth frame of display data, and is The k+1th frame of display data has a second low-level width in the picture period; wherein, there is a second proportional value between the first low-level width and the second low-level width, and the second low-level width The proportional value is equal to the first proportional value, or has a proportional relationship with the first proportional value. The OLED display according to claim 6, wherein the display driver chip includes a register for registering the pixel emission control signal EM included in the T signal periods in the picture period of each frame of display data The T low-level widths are used to facilitate the completion of the low-level width setting. An information processing device having the OLED display according to any one of claim 5 to claim 7. The information processing device according to claim 9, which is an electronic device selected from the group consisting of smart phones, smart watches, smart bracelets, tablet computers, notebook computers, all-in-one computers, and access control devices .

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