CN113674691B

CN113674691B - Display brightness adjusting method and adjusting device

Info

Publication number: CN113674691B
Application number: CN202111003100.6A
Authority: CN
Inventors: 蒋开云; 吴渊
Original assignee: Wuhan China Star Optoelectronics Semiconductor Display Technology Co Ltd
Current assignee: Wuhan China Star Optoelectronics Semiconductor Display Technology Co Ltd
Priority date: 2021-08-30
Filing date: 2021-08-30
Publication date: 2023-03-24
Anticipated expiration: 2041-08-30
Also published as: CN113674691A

Abstract

The embodiment of the invention provides a method and a device for adjusting display brightness, wherein the display brightness corresponding to a selected time period is compared with a target value, when the corresponding brightness value in the time period is greater than the target value, a first dimming system is adopted to adjust the brightness value in a dimming interval, and when the corresponding brightness value in the time period is less than the target value, a second dimming system is adopted to adjust the brightness value in the dimming interval. And then the brightness of the display picture corresponding to different brightness values is adjusted, so that the display quality and the display effect of the display panel are effectively improved.

Description

Display brightness adjusting method and adjusting device

Technical Field

The invention relates to the technical field of display panels, in particular to a method and a device for adjusting display brightness of a display panel.

Background

Organic Light Emitting Diodes (OLEDs) are an emerging display technology, and displays manufactured using OLEDs have wider display viewing angles and higher refresh rates than conventional liquid crystal displays.

In order to provide a good use experience for a user, a display brightness value for adjusting the brightness of the OLED display screen needs to be preset in an electronic device such as a display panel, so that the brightness of the OLED display screen can be adjusted according to the user's experience and the change of the environment when the display screen displays a picture. In the existing adjusting technology, the display brightness is generally adjusted through a DC direct current adjusting system, when the brightness is adjusted in the system, the brightness of the screen is changed by increasing or decreasing the power of the circuit, but when the display panel is in a low brightness condition in the dimming mode, the display picture of the display panel has a problem of uneven color, so that the display quality and the display effect of the display panel are reduced, and the improvement of the comprehensive performance of the panel is not facilitated.

In summary, in the prior art, when the display brightness of the display panel is adjusted, the adjustment mode is relatively single, and when the picture of the display panel with lower brightness is adjusted, the problem of non-uniform color often occurs, which is not favorable for improving the display effect.

Disclosure of Invention

The embodiment of the invention provides a method and a device for adjusting display brightness, which aim to solve the problems that when the image brightness of a display panel is adjusted, the adjustment mode is single, and the adjustment effect and the adjustment quality are not ideal.

In order to solve the above technical problem, the technical method provided by the embodiment of the present invention is as follows:

in a first aspect of the embodiments of the present invention, a method for adjusting display brightness is provided, including the following steps:

lightening a display panel and acquiring the brightness value of the display panel;

comparing the luminance value to a target value;

when the brightness value is larger than the target value, acquiring a first dimming interval corresponding to the brightness value, and adjusting the first dimming interval by adopting a first dimming system;

and when the brightness value is smaller than the target value, acquiring a second dimming interval corresponding to the brightness value, and adjusting the second dimming interval by adopting a second dimming system.

According to an embodiment of the present invention, the first dimming system is a DC dimming system, and the second dimming system is a pulse width dimming system.

According to an embodiment of the present invention, when the pulse width dimming system is adopted for dimming, the second dimming interval is divided into a plurality of continuous sub-dimming intervals, wherein duty ratios of corresponding control signals in at least two of the sub-dimming intervals are the same.

According to an embodiment of the present invention, the duty ratios of the corresponding control signals in a plurality of consecutive sub-dimming intervals are gradually increased.

According to an embodiment of the present invention, the duty ratios of the control signals in a plurality of consecutive sub-dimming intervals are increased in an equal difference or an equal proportion.

According to an embodiment of the present invention, the duty ratios of the control signals in the two sub dimming intervals corresponding to the ends of the second dimming interval are the same.

According to an embodiment of the present invention, the duty ratios of the control signals of at least two sub-dimming intervals in the middle region of the second dimming interval are the same.

According to an embodiment of the present invention, the duty ratio of the control signal in the sub-dimming interval is not 0.

According to an embodiment of the present invention, a duty ratio of the control signal corresponding to the first dimming interval is not smaller than a duty ratio of the control signal corresponding to the second dimming interval.

According to a second aspect of the embodiments of the present invention, there is also provided an adjustment device, including:

the display device comprises a power management chip and a display panel, wherein the power management chip is used for adjusting the brightness of the display panel;

when the power management chip adjusts the display brightness of the display panel, the management chip adjusts according to the adjusting method in the embodiment of the application.

In summary, the embodiments of the present invention have the following beneficial effects:

in order to improve the effect of adjusting the brightness of a display panel, in an embodiment of the present invention, by comparing the corresponding display brightness in a selected time period with a target value, when the corresponding brightness value in the time period is greater than the target value, a first dimming system is used to adjust the brightness value in the dimming interval, and when the corresponding brightness value in a certain time period is less than the target value, a second dimming system is used to adjust the brightness value in the dimming interval. And then through adjusting the luminance of the display frame that different luminance values correspond to, display quality and display effect to effectual improvement display panel, and the effectual use of improving the user feels and the comprehensive properties of panel.

Drawings

The technical solution and other advantages of the present invention will become more apparent from the detailed description of the embodiments of the present invention with reference to the accompanying drawings.

Fig. 1 is a method for adjusting brightness of a display panel provided in an embodiment of the present application;

FIGS. 2-4 are graphs of duty cycles of corresponding control signals in tables 1-3

FIG. 5 is a diagram illustrating a DBV curve of display brightness under different conditions provided in the examples of the present application.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated.

When the display panel normally displays a picture, the display effect of the picture is affected by various factors. For example, the influence of the external environment, the influence of the performance of each internal hardware, and the difference between different driving software and different adjustment modes all bring different influences on the display effect of the display panel. When each hardware cannot be adjusted, the adjustment mode of the display panel is often changed in the prior art, so as to achieve the effect and purpose of improving the display effect of the display panel.

However, in the prior art, when the display brightness of the display panel is adjusted, the adjustment mode is often single, and particularly when the display screen with low gray scale is adjusted, for example, when the gamma value of a 64-order or 32-order gray scale image is adjusted, the black insertion ratio during the adjustment process is too large, so that the problem that the charging of some pixels is incomplete due to the time difference of screen charging easily occurs on the display panel. Specifically, when the brightness of the panel is adjusted, in the case of a low gray scale, the black insertion ratio is too high, and the pixel apertures corresponding to the red pixel cell and the blue pixel cell are relatively large, so that the charging time is relatively long, while the aperture of the green pixel cell is relatively small, and the charging time is relatively small. In the prior art, when different pixel units are adjusted, a single adjustment mode is often adopted, so that the brightness adjustment of the display panel is not ideal, and the display effect of the display panel is affected.

The embodiment of the application provides a method for adjusting display brightness of a display panel, which adjusts the brightness of the corresponding display panel under different gray scale brightness conditions through different adjusting methods, and enables the picture brightness of the display panel to achieve the best quality and display effect.

As shown in fig. 1, fig. 1 is a method for adjusting the brightness of a display panel provided in an embodiment of the present application. Specifically, the method for adjusting the display brightness of the display panel provided in the embodiment of the present application includes the following steps:

s100: lightening a display panel and acquiring the brightness value of the display panel;

s101: comparing the luminance value to a target value;

s102: when the brightness value is larger than the target value, acquiring a first dimming interval corresponding to the brightness value, and adjusting the first dimming interval by adopting a first dimming system;

s103: and when the brightness value is smaller than the target value, acquiring a second dimming interval corresponding to the brightness value, and adjusting the second dimming interval by adopting a second dimming system.

When the display panel normally displays, the corresponding adjusting method is adopted to adjust the brightness of the display panel in different time sequence sections of the control signal. Specifically, a display panel is selected and lit. After the display panel is lighted, certain difference exists between the display brightness corresponding to the panel in different time periods, and the corresponding display brightness values in different time periods corresponding to the display panel are obtained.

And comparing the brightness value with a target brightness value after obtaining each display brightness value corresponding to the display panel. Specifically, for different display products, the corresponding target brightness values may be different, and the corresponding target brightness values of the same product in different use environments may also be different. For example, in the indoor and outdoor areas, the intensity of the ambient light corresponding to the indoor area is weak, and the intensity of the ambient light corresponding to the outdoor area is high. At this time, when the target brightness value is determined, the target brightness value corresponding to the outdoor ambient light is greater than the target brightness value corresponding to the indoor ambient light.

When the display panel displays one or more frames of pictures, and the brightness value corresponding to the displayed pictures is greater than the preset target brightness value, the section corresponding to the frame or the frames is a first dimming interval, and the first dimming interval can correspond to the first dimming interval. At this time, the display brightness of the display picture corresponding to the frame is adjusted by adopting the first dimming system. In the adjusting process, the control signal in the corresponding frame is mainly controlled, so that the aim of adjusting the display brightness is fulfilled.

In this embodiment of the application, when the brightness value corresponding to the display frame is greater than the preset target value, the first dimming system is a DC dimming system, that is, the corresponding time sequence in the first dimming interval is a DC control signal. In the embodiment of the application, when the DC control signal is provided, the DC battery arranged inside the display panel can be used for driving, and according to the brightness required by the display product, a suitable DC voltage or current is provided for the panel, so that the display effect and the display quality of the display panel under the condition of higher brightness are effectively improved.

In the embodiment of the application, the DC direct current dimming system is adopted in the first dimming interval, so that the brightness adjustment of the picture in the display time period is effectively reduced, and the brightness of the display panel reaches the optimal brightness value.

When the DC direct current dimming system is adopted for dimming, in a first regulation interval, such as a t1 time period, a first duty ratio corresponding to a control signal provided to the display panel is A%, wherein A is greater than 0. Under higher brightness, the ratio of the corresponding first duty ratio A% is larger, so that the display effect of the display panel is ensured. In the embodiment of the application, in the time period t1, the value of the first duty ratio a% can be selected to be 90% -97% to ensure the brightness adjusting effect.

Specifically, when the first duty ratio value corresponding to the first dimming interval is determined, the first duty ratio value can be determined by a calculation module arranged inside the display panel, so that the accuracy of the adjustment of the brightness is ensured. After the detection module in the display panel acquires the corresponding brightness value, the brightness value is analyzed and calculated, and a control signal corresponding to the duty ratio is output according to the calculation result. Therefore, the display picture with higher brightness value is adjusted, and the optimal display effect is achieved.

On the other hand, when the acquired display luminance value of the display panel is less than or equal to the target luminance value, the luminance value corresponding to the display image of the display panel is low, and the viewing effect is not ideal when the observer views the display image. In the embodiment of the present application, at this time, the display brightness of the display panel is adjusted by using the second dimming system, so that the display image achieves the best display effect.

Specifically, the second dimming system in the embodiment of the present application is a Pulse Width dimming system, that is, a PWM (Pulse Width Modulation) dimming system. The corresponding control power supply and the control signal square wave are digitalized through the PWM dimming system, and the duty ratio of the square wave is controlled, so that the aim of adjusting the display brightness of the display panel is fulfilled.

Specifically, in the embodiment of the present application, when the brightness value corresponding to the display frame is greater than the preset target value, the display brightness corresponds to the second dimming interval. In the second dimming interval, the corresponding time period is t2, and in the t2 period, one frame or multiple frames of display images can be displayed. The specific situation is determined according to the actually acquired data.

Further, in order to better adjust the display brightness, in this embodiment of the application, the second dimming interval may correspond to a plurality of sub-dimming intervals, for example, each sub-dimming interval is further included in the time period t2, and the brightness of the display panel is better adjusted by controlling a corresponding control signal in each sub-dimming interval or sub-time period, where a duty ratio of the control signal in the sub-dimming interval is not 0.

Specifically, the duty ratio of the corresponding control signal in each sub-dimming interval is adjusted, so that the purpose of adjusting the brightness of the picture is achieved. In the embodiment of the present application, the t2-t9 time period is divided into corresponding NOR1, NOR2, nor3.. NOR9,9 sub-dimming intervals as an example. By adjusting the duty cycle of the corresponding control signal in each sub-dimming interval.

When the display brightness is adjusted by the PWM dimming system, the adjustment is performed by a PWM circuit control unit set inside the display panel. Specifically, the PWM control unit is configured to control a light emitting time of the light emitting diode in each sub-dimming interval, and specifically, a scan signal in the PWM circuit is connected to a gate of a thin film transistor disposed in the PWM control unit, and is configured to scan the PWM control unit line by line. Meanwhile, a data signal in the PWM circuit is connected to a source of a thin film transistor provided in the PWM control unit, and is used to provide the data signal to the corresponding thin film transistor.

And when the control signal is applied, controlling the duty ratio of the PWM control signal in different sub dimming intervals. Specifically, when the duty ratios of the control signals in different sub-dimming intervals are adjusted, as shown in table 1 below, table 1 is the duty ratios of the PWM control signals in different sub-dimming intervals provided in the embodiments of the present application. The HBM dimming interval corresponds to a first dimming interval, and the NOR1-NOR9 correspond to a second dimming interval respectively. Namely, HBM is DC direct current dimming system, and NOR1-NOR9 are PWM dimming system.

TABLE 1 Duty ratio of PWM control signals in different sub-dimming intervals

Dimming interval	Duty cycle
		HBM	97％
NOR1	97％
		NOR2	97％
NOR3	97％
		NOR4	60％
NOR5	45％
		NOR6	22％
NOR7	13％
		NOR8	13％
NOR9	13％

As can be seen from the above table, when the HBM interval corresponds to the first dimming interval, the DC-DC dimming system is used to adjust the brightness of the panel. At this time, the duty ratio of the control signal in the period is high, such as setting the duty ratio of the control signal to 97%. Thereby setting the brightness of the panel to the optimum display effect.

When the display brightness of the display panel is low, the dimming interval corresponds to NOR1-NOR9 in table 1. And in the dimming interval, adjusting the brightness of the display panel by adopting a second dimming system. Specifically, in this embodiment of the present application, in order to enable the second dimming interval to have a better display effect and an adjustment effect, in the plurality of continuous sub-dimming intervals, the duty ratios of the corresponding control signals in at least two continuous sub-dimming intervals are the same.

Specifically, in the embodiment of the present application, from the head to the tail of the second dimming interval, the duty ratio of the PWM control signal is set to gradually decrease as a whole. Meanwhile, during setting, the duty ratios of the control signals in two or more adjacent intervals can be the same, and it is ensured that at least two groups of sub dimming intervals with the lowest duty ratios are set, and the duty ratios of the two groups of corresponding control signals are the same.

Specifically, in the embodiment of the present application, the control signals in the sub-dimming intervals corresponding to NOR1 to NOR3 are set to the same duty ratio, for example, to 97%. The duty ratio of the control signal in the sub-dimming interval corresponding to NOR4-NOR6 is gradually decreased, and in the embodiment of the present application, the duty ratio of the control signal in NOR4 is set to 60%, the duty ratio of the control signal in NOR5 is set to 45%, and the duty ratio of the control signal in NOR6 is set to 22%. The duty ratios of the control signals in the consecutive sub-dimming intervals can also be set according to the equal proportional reduction, and detailed description is omitted here. Meanwhile, in three consecutive sub-dimming intervals corresponding to NOR7-NOR9, the duty ratios of the corresponding control signals are set to the same duty ratio. In the embodiment of the application, the duty ratio of the control signal is set to be 13%.

When the duty ratios of the control signals in the different sub-dimming intervals are adjusted, the duty ratio of the corresponding signal in the NOR7-NOR9 is the minimum, and the sub-dimming intervals corresponding to the minimum duty ratio are set into a plurality of continuous groups. In the embodiment of the application, the duty ratio of the corresponding control signal in the second dimming interval is adjusted, so that the purpose of improving the display brightness of the display panel is achieved. Specifically, as shown in fig. 1, fig. 1 is a schematic diagram of changes of control signals in different intervals provided in the embodiment of the present application. Preferably, the sequence of the sub-dimming intervals corresponding to the different duty ratios may be changed according to actual conditions, and the sequence relationship is not specifically limited.

Further, when the control signals in different dimming intervals are adjusted, the adjustment can be performed by referring to the data in tables 2 to 3, where table 2 is a schematic duty ratio diagram of another control signal provided in this embodiment of the present application.

Table 2: duty cycle of control signal in different dimming intervals

Dimming interval	Duty cycle in the prior art	Duty ratio in the present embodiment
			HBM	97％	97％
NOR1	97％	97％
			NOR2	97％	97％
NOR3	97％	97％
			NOR4	60％	60％
NOR5	45％	45％
			NOR6	22％	22％
NOR7	13％	13％
			NOR8	10％	14％
NOR9	6％	15％

Table 3: duty cycle of control signal in different dimming intervals

Dimming interval	Duty cycle in the prior art	Duty ratio in the present embodiment
			HBM	97％	97％
NOR1	97％	97％
			NOR2	97％	97％
NOR3	97％	97％
			NOR4	60％	60％
NOR5	45％	45％
			NOR6	22％	22％
NOR7	13％	13％
			NOR8	10％	15.6％
NOR9	6％	18.7％

Specifically, in the embodiment of the present application, when the duty ratios of the control signals in a plurality of sub-dimming intervals are set, the duty ratios of the control signals in a plurality of consecutive sub-dimming intervals are gradually increased. Specifically, the arithmetic relation may be increased, or the arithmetic relation may be increased in equal proportion, which specifically corresponds to the data in table 2 and table 3, respectively.

The values of the duty ratios of the control signals in the plurality of continuously increasing sub-dimming intervals are smaller than the value of the duty ratio in the whole dimming interval. Therefore, the duty ratio of the smaller control signal is set to be gradually increased, so that the display brightness and the display effect of the display panel under the condition of low brightness are effectively improved.

Further, the duty ratio of the continuously increasing control signal may be located at an end position of the second dimming interval. Specifically, in the embodiment of the present application, in the second dimming interval corresponding to the NOR1 to the NOR9, the duty ratio of the control signal in the NOR1 to the NOR3 is set to 97%, and the duty ratios of the control signal in the NOR4 to the NOR6 are set to 60%, 45%, and 22%, respectively. In the embodiment of the present application, the duty ratio in NOR1 to NOR6 is the same as the corresponding duty ratio in the prior art. However, in the embodiment of the present application, the duty ratio of the corresponding control signal in NOR7 to NOR9 is different from that in the related art. Specifically, in NOR7 to NOR9, the duty ratio of the control signal is gradually increased. The equal difference relationship is increased and set as 13%, 14% and 15%; or the geometric relationship is increased to 13%, 15.6% and 18.7%.

Further, the gradually increasing sub-dimming intervals are not limited to 3 groups, and may be 2 groups or more, which is not described in detail herein. Meanwhile, the duty ratio of the control signal corresponding to the first dimming interval is not less than that of the control signal corresponding to the second dimming interval. See also the graphical representations in fig. 2-4, respectively. Fig. 2-4 are graphs of duty cycles of corresponding control signals in tables 1-3.

Further, as shown in fig. 5, fig. 5 is a diagram illustrating a DBV curve of display luminance under different conditions provided in the embodiment of the present application. Fig. 5 is a diagram illustrating a DBV curve in the prior art on the left side, and a diagram illustrating a DBV curve obtained in the embodiment of the present application on the right side. The DBV curve obtained at low Gray level (Gray 32) after adjusting according to different dimming systems in the embodiments of the present application is shown. From the above schematic diagram, in the embodiment of the present application, the DBV curve is significantly improved, and the DBV value is closer to the standard value and fluctuates around the standard value y of 0.315, so that the color shift of the display screen is effectively reduced. The display quality and the display effect of the display panel are improved.

Further, the embodiment of the application also provides a brightness adjusting device. Specifically, the brightness adjusting device comprises a power management chip and a display panel, wherein the power management chip provides a power signal to the display panel. The display device also comprises a driving chip, a judging module and a registering module, wherein the judging module detects the display brightness of the current display panel and compares the acquired brightness value with a target brightness value, the driving chip receives the judging data in the judging module, selects different brightness dimming systems, and selects different control signals from the registering module to regulate and control the brightness of the current display panel, so that the brightness of the display panel achieves the best effect. When the display device provided in the embodiment of the application regulates and controls the display picture of the display panel, the display device regulates by the regulating method of the display brightness in the embodiment of the application, so that the display quality and the display effect of the display panel are effectively improved.

The display brightness adjusting method and the display device of the display panel provided by the embodiment of the invention are described in detail above, a specific example is applied in the text to explain the principle and the implementation of the invention, and the description of the above embodiment is only used to help understanding the technical scheme and the core idea of the invention; those of ordinary skill in the art will understand that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. A method for adjusting display brightness is characterized by comprising the following steps:

comparing the brightness value with a target value;

when the brightness value is larger than the target value, acquiring a first dimming interval corresponding to the brightness value, and adjusting the first dimming interval by adopting a first dimming system, wherein the first dimming system is a DC (direct Current) dimming system;

when the brightness value is smaller than the target value, acquiring a second dimming interval corresponding to the brightness value, and adjusting the second dimming interval by adopting a second dimming system, wherein the second dimming system is a pulse width dimming system;

the duty ratio of the control signal corresponding to the first dimming interval is not less than that of the control signal corresponding to the second dimming interval; when the pulse width dimming system is adopted for dimming, the second dimming interval is divided into a plurality of continuous sub-dimming intervals, the duty ratios of the control signals corresponding to at least two sub-dimming intervals are the same, and the duty ratios of the control signals corresponding to the plurality of continuous sub-dimming intervals are gradually increased.

2. The method according to claim 1, wherein the duty ratios of the control signals in a plurality of consecutive sub-dimming intervals are increased in an equal difference or an equal proportion.

3. The method according to claim 1, wherein duty ratios of the control signals in the two sub-dimming intervals corresponding to the ends of the second dimming interval are the same.

4. The method according to claim 1, wherein the duty ratios of the control signals of at least two of the sub-dimming intervals in the middle region of the second dimming interval are the same.

5. The method according to claim 1, wherein the duty ratio of the control signal in the sub-dimming interval is not 0.

6. The method according to claim 1, wherein a duty ratio of the control signal corresponding to the first dimming interval is not less than a duty ratio of the control signal corresponding to the second dimming interval.

7. A luminance adjustment device, characterized by comprising:

wherein, when the power management chip adjusts the display brightness of the display panel, the management chip adjusts according to the adjusting method of any one of claims 1 to 6.