TWI802861B - Dynamic brightness adjustment method of OLED display panel, OLED display device, and information processing device - Google Patents

Abstract

The present invention mainly discloses a dynamic brightness adjustment method of an OLED display panel, which is applied in an OLED display device including at least one display driver chip and an OLED display panel. When the method of the present invention is executed, a pixel light-emitting control signal is sent to at least one light-emitting control signal receiving end of the OLED display panel within the picture period of continuous K frames of display data; wherein, K said pixels are light-emitting The control signals all have at least one brightness adjustment level width, and each pixel lighting control signal is high level or low level within the brightness adjustment level width. Based on the integral effect of the human eye's perception of light, the OLED display can be controlled with high precision by making the lighting control signals of K consecutive pixels be high or low within the brightness adjustment level width. The effect of the digital brightness value of the panel.

Description

Dynamic brightness adjustment method of OLED display panel, OLED display device, and information processing device

The invention relates to the technical field of OLED display devices, in particular to a dynamic brightness adjustment method of an OLED display panel using pixel light emission control signals.

It is known that organic light-emitting diodes (Organic Light-Emitting Diode, OLED) have the advantages of self-luminous characteristics, high brightness, high contrast, wide viewing angle, power consumption, high reaction rate, etc., so it has been widely used in self-luminous The manufacture of display panels includes active OLED (ie, AMOLED) display panels and active OLED (ie, PMOLED) display panels.

FIG. 1 shows a block diagram of a conventional OLED display device. As shown in FIG. 1 , the OLED display device 1a includes: an OLED display panel 11a, a gate driving circuit 12a, a source driving 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 M pixel circuit units 112a along the column direction, and each source driving line 11Sa is coupled to N pixel circuit units 112a along the row direction.

FIG. 2 shows a working timing diagram of a vertical synchronization signal and a pixel lighting control signal used in a conventional OLED display device. As shown in FIG. 1 , each pixel circuit unit 112 a is coupled to a scanning signal Scan and a pixel light emission control signal EM transmitted from the gate driving circuit 12 a. Wherein, the pixel emission control signal EM is a PWM signal, so the brightness control (Brightness control, BC) of each OLED sub-pixel 111a can be realized by adjusting the duty ratio of the PWM signal.

At the same time, due to the self-luminous and high-brightness element characteristics of the OLED sub-pixel 111a, the source drive circuit 13a is usually designed to have an automatic current limit (Auto current limit, ACL) function in consideration of reducing system power consumption, and its main function is When the current (brightness) is high, the excessively high current is attenuated, so as to achieve the purpose of reducing system power consumption. FIG. 3 shows a data graph of pixel luminance of input display data versus pixel luminance of output display data. When performing the current attenuation operation (namely, automatic current limit), the average brightness of a frame of display screen is calculated first, and then the parameter to be attenuated for the frame of display screen is obtained according to the average brightness of a frame. After obtaining the current (brightness) attenuation parameter, each sub-pixel in the input display data of one frame of display screen is scaled down according to the current attenuation parameter (as shown in FIG. 3 ).

In addition, the source driving circuit 13a also has a gamma adjustment function. FIG. 4 shows a data curve graph of digital brightness value (Digital Brightness Value, DBV) relative to gamma setting value. At present, after the gamma correction procedure is completed, the display manufacturer will set a plurality of gamma setting values in the source driving circuit 13a, which are called gamma binding points in the industry, that is, a plurality of fixed gamma gray scale coordinates. As shown in FIG. 4 , the same digital luminance value can be modulated with different gamma setting values.

The aforementioned three methods can be used alone or in combination to adjust the brightness of the OLED display panel 11a. So far, as the resolution of the OLED display panel 11a is getting higher and higher, the fineness of digital brightness value regulation must reach 12 bits. FIG. 5 shows a working timing diagram of the vertical synchronization signal and the lighting control signals of multiple pixels. As shown in Figure 1 and Figure 5, assuming that the OLED display panel 11a is a 40-row/N-column pixel array, in practice, the value of the digital brightness data (DBV) can be controlled between 0~20 or 0 by using the pixel light emission control signal EM. ~40 changes. Unfortunately, if the pixel light emitting control signal EM is used to control the value of DBV to vary from 0 to 80, the control accuracy will be distorted. For example, as shown in FIG. 5 , the minimum modulation precision limited by the duty cycle (Duty cycle) of the pixel light emission control signal EM is 1 line (1 line), and the value of the digital brightness data can be controlled at 40 With 42, but could not be controlled at 41.

In other words, when the range of DBV controlled by the pixel light emission control signal EM is greater than the total lines of the source driving lines 11Sa of the panel, the phenomenon of control precision distortion will occur. To further explain, as far as the pixel emission control signal EM is used to control the DBV value of the FHD (1920×1080) OLED display panel 11a, the control results are shown in the following tables (1A) and (1B). Table (1A) DBV Control the number of rows of light by changing the duty cycle of EM 0 0 1 0 2 0 3 0 4 0 5 1 6 1 7 1 8 1 ‧ ‧ ‧ ‧ ‧ ‧ Table (1B) DBV Control the number of rows of light by changing the duty cycle of EM 8172 1915 8173 1915 8174 1916 8175 1916 8176 1916 8177 1916 8178 1916 8179 1917 ‧ ‧ ‧ ‧ ‧ ‧ 8187 1919 8188 1919 8189 1919 8190 1919 8191 1920

From Table (1A) and Table (1B), it can be found that when DBV=5~8, 8174~8178, 8187~8190, the brightness of OLED display panel 11a does not change, the main reason is that: the use of changing pixels to emit light The duty ratio of the control signal EM is 1 line with the minimum accuracy of controlling the number of light-emitting lines. Therefore, practical experience shows that the conventional technique of controlling the DBV range of the OLED display panel 11a by using the pixel light emission control signal EM shows a major defect of distortion of control precision.

It can be seen from the above description that there is an urgent need in the art for a new dynamic brightness adjustment method for OLED display panels.

The main purpose of the present invention is to provide a dynamic brightness adjustment method of an OLED display panel, which is applied in an OLED display device including at least one display driver chip and an OLED display panel. When implementing the dynamic brightness adjustment method of the OLED display panel of the present invention, each transmits a pixel light-emitting control signal to at least one light-emitting control signal receiving end of the OLED display panel in the frame period of continuous K frames of display data; wherein, The K pixel light emission control signals all have at least one brightness adjustment level width, and each of the pixel light emission control signals is at a high level or a low level within the brightness adjustment level width. Based on the integral effect of the human eye's perception of light, the OLED display can be controlled with high precision by making the lighting control signals of K consecutive pixels be high or low within the brightness adjustment level width. The effect of the digital brightness value of the panel.

In order to achieve the above object, the present invention proposes an embodiment of the dynamic brightness adjustment method of the OLED display panel, which is applied in an OLED display device including at least one display driver chip and an OLED display panel, and includes the following steps:

In the picture period of continuous K frames of display data, each pixel light emission control signal is sent to at least one light emission control signal receiving end of the OLED display panel, wherein, K is a positive integer, and the K pixel light emission control signals are all There is at least one brightness adjustment level width, and each pixel light emission control signal is high level or low level within the brightness adjustment level width, thereby adjusting a digital brightness value of the OLED display panel.

In one embodiment, each pixel light emission control signal has T signal periods and T brightness adjustment level widths within a corresponding frame period of the display data, where T is at least 1.

In one embodiment, the brightness adjustment level widths of any two pixel lighting control signals are the same.

In one embodiment, the adjustment accuracy of the digital luminance value of the K consecutive pixel lighting control signals increases as the value of K increases.

Moreover, the present invention also provides an OLED display device, which includes at least one display driver chip and an OLED display panel, wherein the display driver chip is used to implement a dynamic brightness adjustment method of an OLED display panel to adjust the brightness of the OLED display panel. A digital brightness value; the dynamic brightness adjustment method of the OLED display panel comprises the following steps:

In the picture period of continuous K frames of display data, each pixel light emission control signal is sent to at least one light emission control signal receiving end of the OLED display panel, wherein, K is a positive integer, and the K pixel light emission control signals are all There is at least one brightness adjustment level width, and each pixel lighting control signal is high level or low level within the brightness adjustment level width.

In one embodiment, each pixel light emission control signal has T signal periods and T brightness adjustment level widths within a corresponding frame period of the display data, where T is at least 1.

In one embodiment, the brightness adjustment level widths of any two pixel lighting control signals are the same.

In one embodiment, the adjustment accuracy of the digital luminance value of the K consecutive pixel lighting control signals increases as the value of K increases.

The present invention also provides an information processing device, which has the aforementioned OLED display device of the present invention.

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, features, purpose, and advantages of the present invention, drawings and detailed descriptions of preferred specific embodiments are hereby attached.

The present invention mainly discloses a dynamic brightness adjustment method of an OLED display panel, which is applied to an OLED display device including at least one display driver chip and an OLED display panel, so that the display driver chip uses the dynamic brightness adjustment method of the present invention A display brightness control is performed on the OLED display panel.

FIG. 6 shows a block diagram of an OLED display device applied with a method for improving the brightness adjustment accuracy of a display panel of the present invention. As shown in Figure 6, the OLED display device 1 includes: an OLED display panel 11, a gate drive circuit 12, a source drive circuit 13, and a display controller 14, wherein the gate drive circuit 12 and the source The electrode driving circuit 13 can be integrated into a single display driving chip. Moreover, 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, both N and M is a positive integer. In more detail, each pixel circuit unit 112 is coupled to a scan signal Scan and a pixel light emission control signal EM transmitted from the gate drive circuit 12 at the same time.

FIG. 7 shows a flowchart of a method for dynamically adjusting brightness of an OLED display panel according to the present invention. As shown in FIG. 3 and FIG. 4 , the method flow first executes step S1 : the gate driving circuit 12 receives a display brightness adjustment command. The method flow proceeds to step S2: the gate drive circuit 12 transmits a pixel light emission control signal EM to at least one light emission control signal receiving end of the OLED display panel 11 within the picture period of continuous K frames of display data, wherein, Each of the K pixel light emission control signals EM has at least one brightness adjustment level width, and each pixel light emission control signal EM is at a high level or a low level within the brightness adjustment level width.

In a feasible embodiment, K is a positive integer, and each pixel light emission control signal EM has T signal periods and T brightness adjustment level widths within the picture period of one frame of display data corresponding to it. , T is at least 1. FIG. 8 shows a working timing diagram of a vertical synchronization signal, a pixel lighting control signal used in the prior art, and a pixel lighting control signal used in the present invention. As shown in FIG. 8, after receiving the display brightness adjustment command, the gate drive circuit in the prior art will transmit the pixel light-emitting control signal (that is, the PWM signal) with a specific duty cycle to the OLED display panel. At least one light emission control signal receiving end, thereby using the pixel light emission control signal EM to adjust the digital brightness value (DBV) of the OLED display panel. For example, as shown in FIG. 8, EM1 is used to adjust the DBV value to 40, and EM2 Used to adjust the DBV value to 42. However, limited by the minimum modulation accuracy of the duty cycle (Duty cycle) of the pixel light emission control signal EM is 1 line (1 line), the conventional technology can control the value of the digital brightness data at 40 and 42, but cannot Adjust it to 41.

As shown in FIG. 8, in the case of applying the dynamic brightness adjustment method of the present invention, a pixel emission control signal EM can be sent to at least one of the OLED display panel 11 within the frame period of two consecutive frames of display data. The control signal receiving end, wherein, the pixel light emission control signal EM transmitted in the picture period of the first frame (Frame 1) display data is high level within its brightness adjustment level width (ie, bit 1) , and the pixel light emission control signal EM transmitted in the frame period of the display data of the second frame (Frame 2) is low level (ie, bit 0) within the brightness adjustment level width. Moreover, the brightness adjustment level widths of the two pixel light emission control signals EM are the same. Based on the integral effect of the human eye's perception of light, after sending a pixel light emission control signal EM to the OLED display panel 11 in the picture period of two consecutive frames of display data, the DBV value of the OLED display panel perceived by the human eye The system is adjusted to DBV=(40+42)/2=41.

In other words, after each pixel emission control signal EM is sent to the light emission control signal receiving end of the OLED display panel 11 within the picture period of continuous K frames of display data, the adjustment degree of the DBV value of the OLED display panel 11 can be controlled by It is determined by an average level of the light emitting control signals EM of K pixels within the width of the brightness adjustment level. Tables (2)-(5) below exemplarily list the average levels under different K values. Table 2) K=3 The level of each pixel light emission control signal EM within the brightness adjustment level width (1, 0 represent high level, low level) The first frame (Frame 1) 1 1 The second frame (Frame 2) 0 1 The third frame (Frame 3) 0 0 average value 0.333 0.666 table 3) K=4 The level of each pixel light emission control signal EM within the brightness adjustment level width (1, 0 represent high level, low level) The first frame (Frame 1) 1 1 1 The second frame (Frame 2) 0 0 1 The third frame (Frame 3) 0 1 1 The fourth frame (Frame 4) 0 0 0 average value 0.25 0.5 0.75 Table 4) K=5 The level of each pixel light emission control signal EM within the brightness adjustment level width (1, 0 represent high level, low level) The first frame (Frame 1) 1 1 1 1 The second frame (Frame 2) 0 0 0 1 The third frame (Frame 3) 0 1 1 1 The fourth frame (Frame 4) 0 0 0 0 Fifth frame (Frame 5) 0 0 1 1 average value 0.2 0.4 0.6 0.8

Assuming that the OLED display panel 11 is a 40-row/N-column pixel array, the conventional technology uses the pixel light emission control signal EM to control the DBV value to change from 0 to 20 or 0 to 40, but the adjustment accuracy will appear after exceeding 40. The reason for the distortion phenomenon is that in terms of the physical sense, the minimum modulation precision of the duty cycle (Duty cycle) of a single pixel light emission control signal EM for the brightness of the OLED display panel 11 is 1 line. However, in the case of applying the dynamic brightness adjustment method of the present invention, in terms of non-substantial physical sense, the minimum modulation accuracy of the duty cycle (Duty cycle) of the light emission control signal EM of K pixels is 1/K Lines, such as 0.5, 0.33, 0.25 lines. It is conceivable that as the value of K increases, the accuracy of adjusting the DBV value of the OLED display panel 11 by the continuous K pixel light emission control signals EM increases accordingly.

In more detail, even if the working timing of each of the pixel light emission control signals EM is changed, the DVB value adjustment degree determined by the continuous K pixel light emission control signals EM may also be the same, as shown in the following table (6A)~(6B ) shown. Table (6A) K=3 The level of each pixel light emission control signal EM within the brightness adjustment level width (1, 0 represent high level, low level) The first frame (Frame 1) 1 1 The second frame (Frame 2) 0 1 The third frame (Frame 3) 0 0 average value 0.333 0.666 Form (6B) K=3 The level of each pixel light emission control signal EM within the brightness adjustment level width (1, 0 represent high level, low level) The first frame (Frame 1) 1 0 The second frame (Frame 2) 0 1 The third frame (Frame 3) 0 1 average value 0.333 0.666 Table (6C) K=3 The level of each pixel light emission control signal EM within the brightness adjustment level width (1, 0 represent high level, low level) The first frame (Frame 1) 1 1 The second frame (Frame 2) 0 0 The third frame (Frame 3) 0 1 average value 0.333 0.666

In other words, the adjustment degree of the DBV value of the OLED display panel 11 can also be changed by arbitrarily adjusting the working timing of the pixel light emission control signal EM (ie, the PWM signal), for example: making it a multi-pulse PWM signal , that is, it has T signal periods and T low-level widths. Alternatively, adjust the width of the low level to change the position of the brightness adjustment level width (that is, change the size of the brightness adjustment level width).

In this way, the above has completely and clearly described a method for adjusting the dynamic brightness of an OLED display panel of the present invention; and, through the above, it can be known that the present invention has the following advantages:

(1) The present invention discloses a dynamic brightness adjustment method of an OLED display panel, which is applied in an OLED display device including at least one display driver chip and an OLED display panel. When the method of the present invention is executed, a pixel light-emitting control signal is sent to at least one light-emitting control signal receiving end of the OLED display panel within the picture period of continuous K frames of display data; wherein, K said pixels are light-emitting The control signals all have at least one brightness adjustment level width, and each pixel lighting control signal is high level or low level within the brightness adjustment level width. Based on the integral effect of the human eye's perception of light, the OLED display can be controlled with high precision by making the lighting control signals of K consecutive pixels be high or low within the brightness adjustment level width. The effect of the digital brightness value of the panel.

(2) The present invention also provides an OLED display device, which includes at least one display driver chip and an OLED display panel, and the display driver chip is used to implement the aforementioned dynamic brightness adjustment method for an OLED display panel of the present invention.

(3) The present invention also provides an information processing device having the aforementioned OLED display device of the present invention. Moreover, 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.

It must be emphasized that what is disclosed in the above-mentioned case is a preferred embodiment, and all partial changes or modifications derived from the technical ideas of this case and easily deduced by those familiar with the technology are all inseparable from the patent of this case. category of rights.

To sum up, regardless of the purpose, means and efficacy of this case, it shows that it is very different from the conventional technology, and its first invention is practical, and it does meet the patent requirements of the invention. I implore your review committee to understand clearly and grant a patent as soon as possible to benefit you Society is for the Most Prayer.

1a: OLED display device 11a: OLED display panel 111a: OLED sub-pixel 112a: pixel circuit unit 11Sa: source drive line 11Ga: Gate drive line 12a: Gate drive circuit 13a: Source drive circuit 14a: Display Controller 1: OLED display device 11:OLED display panel 111: OLED sub-pixel 112:Pixel circuit unit 11S: Source drive line 11G: Gate drive line 12: Gate drive circuit 13: Source drive circuit 14: Display Controller S1: the gate drive circuit receives a display brightness adjustment command; S2: The gate drive circuit transmits a pixel light emission control signal to at least one light emission control signal receiving end of the OLED display panel in the picture period of continuous K frames of display data, wherein the light emission control signals of the K pixels are The signals all have at least one brightness adjustment level width, and each of the pixel lighting control signals is high level or low level within the brightness adjustment level width

1 is a block diagram of a known OLED display device; 2 is a working timing diagram of a vertical synchronization signal and a pixel light emission control signal used in a conventional OLED display device; Fig. 3 is a data curve diagram of the pixel brightness of the input display data relative to the pixel brightness of the output display data; FIG. 4 is a data graph showing digital luminance values relative to gamma setting values; FIG. 5 is a working timing diagram of a vertical synchronization signal and a plurality of pixel lighting control signals; 6 is a block diagram of an OLED display device applied with a method for improving the brightness adjustment accuracy of a display panel according to the present invention; 7 is a flow chart of a method for dynamically adjusting brightness of an OLED display panel according to the present invention; and FIG. 8 is a timing diagram of a vertical synchronization signal, a pixel lighting control signal used in the prior art, and a pixel lighting control signal used in the present invention.

S1: The gate drive circuit receives a display brightness adjustment command

S2: The gate drive circuit transmits a pixel light emission control signal to at least one light emission control signal receiving end of the OLED display panel in the picture period of continuous K frames of display data, wherein the light emission control signals of the K pixels are The signals all have at least one brightness adjustment level width, and each of the pixel lighting control signals is high level or low level within the brightness adjustment level width

Claims (8)

A dynamic brightness adjustment method for an OLED display panel, which is applied in an OLED display device including at least one display driver chip and an OLED display panel, and includes the following steps: within K picture periods of continuous K frames of display data, each transmitting a pixel light emission control signal to at least one light emission control signal receiving end of the OLED display panel, wherein K is a positive integer greater than 1, and the K pixel light emission control signals all have at least one brightness adjustment level width, Each of the pixel light-emitting control signals is at a high level or low level within its brightness adjustment level width, and the K pixel light-emitting control signals have an average duty ratio with a minimum modulation accuracy, and the average duty cycle The minimum modulation accuracy of the empty ratio is 1/K lines. The dynamic brightness adjustment method of an OLED display panel as described in Claim 1, wherein each pixel light emission control signal has T signal periods and T brightness within the frame period of a frame of display data corresponding to it Adjust the level width, T is at least 1. The method for dynamically adjusting brightness of an OLED display panel as described in claim 1, wherein the adjustment accuracy of the digital brightness value of the continuous K pixel light emission control signals increases as the value of K increases. An OLED display device comprising at least one display driver chip and an OLED display panel, wherein the display driver chip is used to implement a dynamic brightness adjustment method of an OLED display panel to adjust a digital brightness value of the OLED display panel; The dynamic brightness adjustment method of the OLED display panel includes the following steps: within K picture periods of continuous K frames of display data, each transmits a pixel light emission control signal to at least one light emission control signal receiving end of the OLED display panel, wherein, K is a positive integer greater than 1, and the K pixel light-emitting control signals all have at least one brightness adjustment level width, and each pixel light-emitting control signal is high or low within its brightness adjustment level width In other words, the K pixel lighting control signals have a minimum modulation precision of an average duty cycle, and the minimum modulation precision of the average duty cycle is 1/K lines. The OLED display device as described in claim 4, wherein each of the pixel light emission control signals has T signal periods and T brightness adjustment level widths within the corresponding frame period of the display data, T is at least 1. The OLED display device according to claim 4, wherein the adjustment accuracy of the digital luminance value of the K consecutive pixel light emission control signals EM is improved as the value of K increases. An information processing device having the OLED display device described in any one of claim 4 to claim 6. The information processing device as described in claim 7, 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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