WO2020103887A1

WO2020103887A1 - Backlight driving method and display device

Info

Publication number: WO2020103887A1
Application number: PCT/CN2019/119834
Authority: WO
Inventors: 张玉欣; 杜强; 董晓滨
Original assignee: 海信视像科技股份有限公司
Priority date: 2018-11-22
Filing date: 2019-11-21
Publication date: 2020-05-28
Also published as: CN111210778A

Abstract

A backlight driving method and a display device, the method involving: when it is determined that a driving signal of a backlight source needs to be adjusted, increasing the PWM frequency of the driving signal; and then modulating the driving signal for driving the backlight source according to the determined PWM frequency and the PWM duty cycle determined by image information. When displaying a low grayscale image, the display device can increase the PWM frequency of the driving signal of a control region while maintaining the brightness of an image in the control region corresponding to a low gray-scale image unchanged, so that the low-level duration between two high levels of the driving signal is reduced so as to reduce the flickering perceptibility when the low gray-scale image is displayed.

Description

Backlight driving method and display device

Related applications cross reference

This application claims the priority of the Chinese patent application filed on November 22, 2018 in the Chinese Patent Office, with the application number 201811396664.9 and the invention titled "A method and device for backlight drive signal modulation", the entire contents of which are incorporated by reference In this application.

Technical field

The present application relates to the field of display technology, in particular to a backlight driving method and a display device.

Background technique

At present, with the development of display technology, liquid crystal displays have been widely used in various industries. During display, the liquid crystal display needs to dynamically control the backlight source to meet different display brightness requirements.

The method of dynamic backlight control technology in the related art is to divide the LCD backlight into a plurality of partitions, determine the brightness of each partition according to the brightness information contained in the image information, and dynamically change the brightness of each backlight partition according to the determined brightness brightness. Among them, the bright part of the image corresponds to a higher backlight brightness, and the dark scene part of the image corresponds to a lower backlight brightness, thereby improving the contrast between the light and dark of the picture and improving the picture quality.

In the related art, when a liquid crystal display with a dynamic backlight control function displays a low grayscale image, the PWM (Pulse Width Modulation) duty cycle of the backlight drive signal will be relatively low, which can be understood as driving in a backlight During the PWM period of the signal, the proportion of the backlight lighting time is relatively low, and most of the time is off. In this way, when displaying a low-grayscale image, there will be a flicker due to the backlight being turned off for too long.

However, with the promotion of liquid crystal displays, liquid crystal displays have been used in special fields such as aerospace and automotive, and in these special fields, the demand for the display effect of the display device in low gray scale display is very high. In addition, when the TV pursues a high-quality display effect, it should also consider the low grayscale performance.

In summary, the current liquid crystal displays have a flickering feeling when displaying low-grayscale images.

Summary of the invention

The present application provides a method and device for modulating a backlight driving signal, to solve the problem in the related art that a liquid crystal display has a flickering sensation when displaying a low-grayscale image.

An embodiment of the present application provides a method for modulating a backlight driving signal. The method includes:

When judging that the drive signal of the backlight needs to be adjusted according to the image information, increase the PWM frequency of the drive signal;

The drive signal is modulated according to the determined PWM frequency and the PWM duty ratio determined by the image information.

In the above method, when it is determined that the drive signal of the backlight needs to be adjusted according to the image information, the PWM frequency of the drive signal is increased; and then the drive signal of the backlight is modulated according to the determined PWM frequency and the PWM duty cycle determined by the image information . In this way, when displaying the low-gray-scale image, the display device determines the corresponding PWM duty cycle of the drive signal of the control region corresponding to the low-gray-scale image according to the image information, while increasing the drive signal of the control region corresponding to the low-gray-scale image The PWM frequency of the PWM signal in the embodiment of the present application is still determined according to the image information, so the brightness of the image in the control area corresponding to the low-grayscale image can be unchanged, and at the same time The PWM frequency of the driving signal of the corresponding control area, so the duration of the low level between the two high levels of the driving signal is reduced, which in turn makes the time of the dark screen between the two lighting of the backlight shorter, so this application is implemented For example, it is possible to reduce the flicker that exists when displaying low-grayscale images while maintaining the same brightness.

In a possible implementation manner, whether the backlight driving signal needs to be adjusted is determined in the following manner:

Determine the image display brightness according to the image information;

If the image display brightness is not greater than the preset brightness threshold, it is determined that the driving signal of the backlight needs to be adjusted.

In the above method, the image display brightness is first determined according to the image information; then the determined image display brightness is compared with a preset brightness threshold, and if it is determined that the image display brightness is not greater than the preset brightness threshold, the image corresponding to the image information can be determined For low-grayscale images, make sure to adjust the drive signal of the backlight.

In a possible implementation manner, the step of increasing the PWM frequency of the driving signal when it is judged according to the image information that the driving signal of the backlight source needs to be adjusted includes: the backlight source is zone control,

For any partition, when it is determined that the drive signal of the backlight controlled by the partition needs to be adjusted according to the image information of the pixels on the image in the partition, the PWM frequency of the drive signal is increased.

In the above method, when the control method of the backlight of the display device is partition control, the display device will process each control partition of the backlight separately. At this time, the display device is based on the image of all pixels on the image in each partition When the information determines that the driving signal of the backlight controlled by the partition needs to be adjusted, the PWM frequency of the driving signal is increased. In this way, the display device can determine the PWM frequency of the corresponding increased drive signal and the PWM duty cycle of the corresponding drive signal for each control zone of the backlight, and then according to the determined PWM of the increased drive signal The drive signal is modulated by the frequency and the corresponding PWM duty cycle, so that the drive signal of the backlight source can be accurately controlled according to the brightness of each partition.

In a possible implementation manner, it is determined whether the driving signal of the backlight source needs to be adjusted in the following manner: the backlight source is zoned control,

For any partition, the display brightness of the first image of the partition is determined according to the image information of the pixels on the image in the partition;

If the display brightness of the first image is not greater than the preset first brightness threshold, it is determined that the driving signal of the backlight controlled by the partition needs to be adjusted.

In the above method, when the control mode of the backlight of the display device is partition control, the display device processes each partition separately. And for any partition, the display device determines the display brightness of the first image of the partition based on the image information of all pixels on the image in the partition, and then determines that the display brightness of the first image is not greater than the preset brightness threshold. The driving signal of the backlight controlled by the partition is adjusted, and then the PWM frequency of the driving signal can be increased to reduce the flickering feeling in the low gray scale display.

In a possible implementation manner, the increasing the PWM frequency of the driving signal includes:

Determine the magnification of the PWM frequency corresponding to the brightness of the first image according to the correspondence between the brightness of the first image and the magnification of increasing the PWM frequency;

Increasing the PWM frequency of the drive signal according to the determined magnification of the PWM frequency increase;

Wherein, the increase rate of the PWM frequency is greater than or equal to 1.

In the above method, when the control mode of the backlight of the display device is partition control, after the display device determines the display brightness of the first image of each partition, the display device will display the brightness and the first image according to the determined first image of each control partition The corresponding relationship between the display brightness and the PWM frequency increasing magnification determines the magnification of the PWM frequency of the drive signal corresponding to the zone, and increases the PWM frequency of the driving signal according to the determined PWM frequency magnification. In this way, the display device can increase the PWM frequency of the driving signal, so that the duration of the low level between the two high levels of the driving signal is reduced, so that the time of the dark screen between the two times of the backlight is shortened, According to this, the flickering feeling existing in the low gray scale display is reduced.

In a possible implementation manner, the backlight is controlled by the entire area;

When it is determined according to the image information that the driving signal of the backlight needs to be adjusted, increasing the PWM frequency of the driving signal includes:

When it is determined that the drive signal of the backlight controlled by the entire area needs to be adjusted according to the image information of pixels on the image in the entire control area, increase the PWM frequency of the drive signal.

In the above method, when the control method of the backlight of the display device is the whole area control, the display device determines that the drive signal of the backlight control of the entire area needs to be adjusted according to the image information of all pixels on the image in the entire control area Time, the PWM frequency of the drive signal is increased. In this way, when displaying a low grayscale image, the display device can increase the PWM frequency of the driving signal of the entire backlight source, so that the low level duration between the two high levels of the driving signal can be maintained while maintaining the brightness unchanged The reduction makes the time of the dark screen between the two lighting of the backlight shorter, so as to reduce the flickering feeling in the low gray scale display.

In a possible implementation manner, the display device determines whether the driving signal of the backlight source needs to be adjusted in the following manner: the backlight source is controlled by the entire area,

Determining the display brightness of the second image of the entire control area according to the image information of pixels on the image in the entire control area;

If the display brightness of the second image is not greater than the preset second brightness threshold, it is determined that the driving signal of the backlight controlled by the entire area needs to be adjusted.

In the above method, when the control method of the backlight of the display device is full-area control, the display device determines the display brightness of the second image of the entire control area according to the image information of all pixels on the image in the entire control area, and then the second image When the display brightness is not greater than the preset second brightness threshold, it is determined that the driving signal of the backlight controlled by the entire area needs to be adjusted, and then the PWM frequency of the driving signal of the entire area can be increased to reduce the low grayscale display The presence of flicker.

Determine the magnification of the increase in PWM frequency corresponding to the brightness of the second image according to the correspondence between the brightness of the second image and the increase in the PWM frequency;

Wherein, the increase rate of the PWM frequency is greater than or equal to 1.

In the above method, when the control method of the backlight of the display device is the whole area control, after the display device determines the display brightness of the second image in the entire control area, the display brightness according to the determined second image display brightness and the second image display brightness and PWM The corresponding relationship between the frequency-increasing magnification determines the PWM frequency-increasing magnification corresponding to the second image display brightness of the entire control area, and then increases the driving signal according to the determined PWM frequency-increasing magnification. PWM frequency. In this way, the display device can increase the PWM frequency of the driving signal, so that the duration of the low level between the two high levels of the driving signal is reduced, thereby shortening the time of the dark screen between the two times the backlight is lit , To reduce the flicker that exists in low-grayscale display.

In a possible implementation manner, for any pixel, the grayscale value of the pixel in the control area is determined according to the image information of the image in the control area;

According to the correspondence between the gray scale value and the gray scale compensation value, determine the gray scale compensation value corresponding to the gray scale value of the pixel in the control area;

The grayscale value of the pixel in the control area is compensated according to the determined grayscale compensation value.

In the above method, for any pixel, when the display device displays an image, it can also determine the grayscale value of the pixel in the control area according to the image information of the image in the control area; then according to the grayscale value and the grayscale compensation value The corresponding relationship determines the corresponding grayscale compensation value, and then performs grayscale compensation according to the determined grayscale value of the pixel, and displays according to the compensated grayscale value, so that the details of the displayed low grayscale image can be made It's clearer, and get better display effect.

In a second aspect, an embodiment of the present application further provides a device for modulating a backlight driving signal, including: a processing unit and a storage unit, and the display device has a function of implementing the foregoing embodiments of the first aspect.

In a third aspect, an embodiment of the present application further provides an apparatus for modulating a backlight driving signal. The apparatus includes a determining unit, a modulating unit, and a compensating unit. The apparatus has functions for implementing the foregoing embodiments of the first aspect.

In addition, for the technical effects brought by any one of the implementation manners of the second aspect to the third aspect, refer to the technical effects brought by the different implementation manners of the first aspect, and details are not described herein again.

BRIEF DESCRIPTION

In order to more clearly explain the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. Those of ordinary skill in the art can obtain other drawings based on these drawings without paying any creative labor.

FIG. 1A is a functional block diagram of dynamic backlight control involved in an embodiment of the present application;

FIG. 1B is a functional block diagram of a multi-channel backlight drive designed for dynamic partition control of a backlight source according to an embodiment of this application;

2 is a schematic flowchart of a method for modulating a backlight driving signal according to an embodiment of the present application;

FIG. 3 is a schematic diagram of a control partition when the backlight source is partition control in the embodiment of the present application;

4 is a schematic diagram of a control partition containing 4 pixels in an embodiment of the present application;

5 is a function that can be used for gray scale compensation provided in an embodiment of this application;

FIG. 6 is a detailed schematic flowchart of a method for modulating a backlight driving signal when the backlight provided by an embodiment of the present application is partition control; FIG.

7 is a detailed schematic flowchart of a method for modulating a backlight driving signal when the backlight provided by the embodiment of the present application is partition control;

8 is a schematic structural diagram of a first backlight driving signal modulation device provided by an embodiment of the present application;

9 is a schematic structural diagram of a second device for modulating a backlight driving signal according to an embodiment of the present application;

10 is a schematic structural diagram of a third device for modulating a backlight driving signal according to an embodiment of the present application;

11 is a waveform diagram of a PWM driving a backlight in the prior art;

12 is a waveform diagram of a PWM driving a backlight provided by an embodiment of the present application.

detailed description

The embodiment of the present application relates to a method for mixing and dynamically modulating the driving signal of the backlight of the display device, and is applied to the scenario of controlling the driving signal of the backlight of the display device as shown in FIGS. 1A-1B. In the embodiment of the present application, the display device determines the corresponding PWM duty cycle of the driving signal of the control region corresponding to the low-grayscale image according to the image information, and at the same time increases the PWM frequency of the driving signal of the backlight source according to the determined The PWM duty cycle and the increased PWM frequency generate a driving signal of the backlight source to drive the backlight source. In this way, the brightness of the backlight source can be ensured unchanged; at the same time, the duration of the low level between the two high levels of the driving signal is reduced, thereby making the dark screen time between the two times of the backlight source shorter, and reducing the low gray The flicker that exists in the first order display. In addition, while increasing the PWM frequency of the driving signal of the backlight to reduce the flickering feeling existing in the low-grayscale display, the display device can also use the corresponding relationship between the preset grayscale value and the grayscale compensation value to Determine the gray scale value and perform gray scale compensation to obtain a better display effect.

When generating the driving signal of the backlight source, the backlight processing unit of the display device may send current data to the PWM driver, and the PWM driver adjusts the current according to the current data and the preset reference voltage Vref, so that the output pulse bandwidth signal satisfies the determined The PWM duty cycle.

In the implementation of this application, when displaying a low grayscale image, the PWM frequency of the driving signal of the backlight is increased to reduce the low-level duration between the two high levels of the driving signal, thereby making the backlight two The dark screen time between secondary lighting becomes shorter, reducing the flickering sensation that exists when displaying low-grayscale images. At this time, it is necessary to simultaneously generate a driving signal according to the increased PWM frequency and the determined PWM duty ratio.

During the driving signal, the backlight processing unit of the display device will send current data calculated according to the PWM frequency and the determined PWM duty cycle to the PWM driver, and the PWM driver adjusts according to the current data and the preset reference voltage Vref Current, and finally get the generated drive signal.

In order to make the purpose, technical solutions and advantages of the present application more clear, the present application will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments . Based on the embodiments in this application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of this application.

As shown in FIG. 2, an embodiment of the present application provides a method for modulating a backlight driving signal. The method includes:

The drive signal is modulated according to the determined PWM frequency and the PWM duty cycle determined by the image information.

In the above method, when it is determined that the drive signal of the backlight needs to be adjusted according to the image information, the PWM frequency of the drive signal is increased; then the drive of the backlight is generated according to the determined PWM frequency and the PWM duty cycle modulation determined by the image information signal. In this way, when displaying the low-gray-scale image, the PWM duty cycle of the driving signal corresponding to the control region corresponding to the low-gray-scale image is determined according to the image information, and at the same time, the PWM of the driving signal of the control region corresponding to the low-gray-scale image is increased. Frequency, because the PWM duty cycle of the driving signal in the embodiment of the present application is still determined according to the image information, the brightness of the image in the control area corresponding to the low grayscale image can be unchanged, and at the same time The PWM frequency of the driving signal in the control area is reduced, so the duration of the low level between the two high levels of the driving signal is reduced, which further shortens the time of the dark screen between the two times of the backlight, so the embodiment of the present application can Under the premise of ensuring the brightness is unchanged, the flickering feeling existing when displaying low-grayscale images is reduced.

In the specific implementation, it is first necessary to determine that the driving signal of the backlight needs to be adjusted according to the image information.

In an embodiment, whether the backlight driving signal needs to be adjusted is determined in the following manner:

Determine the image display brightness according to the image information; if the image display brightness is not greater than the preset brightness threshold, determine that the drive signal of the backlight needs to be adjusted.

In the above method, the image display brightness corresponding to the image is first determined according to the image information of the image to be displayed; then the determined image display brightness is compared with a preset brightness threshold, if it is determined that the image display brightness is not greater than the preset brightness threshold , It can be determined that the image corresponding to the image information is a low grayscale image, and it is determined that the driving signal of the backlight needs to be adjusted.

Further, if the brightness of the image display is greater than the preset brightness threshold, there is no need to adjust the drive signal of the backlight by default, there is no need to increase the PWM frequency of the drive signal, the frequency will not be switched, and the fixed frequency and The determined PWM duty cycle modulation generates a drive signal.

Since the numerical value of the duty ratio can reflect the brightness of the image, the duty cycle of the PWM corresponding to the low grayscale image is small, and the duty cycle of the PWM corresponding to the high grayscale image is high.

Determine the duty cycle according to the image information; if the duty cycle is not greater than the preset duty cycle threshold, determine that the drive signal of the backlight needs to be adjusted.

If the duty cycle is greater than the preset duty cycle threshold, there is no need to adjust the drive signal of the backlight by default, there is no need to increase the PWM frequency of the drive signal, the frequency will not be switched, and the fixed frequency is used and determined The PWM duty cycle modulation generates the drive signal.

The method of determining the duty ratio is applicable to the entire area control and also to the partition control. The determination of the duty ratio can be determined according to the currently existing method of determining the duty ratio. In an embodiment of this application, the The brightness of the image is determined with the pre-stored mapping table.

The following describes how to judge the image display brightness.

Wherein, the control mode of the backlight of the display device may be zone control or whole zone control.

Among them, the control method of the backlight of the display device is partition control, which means that the backlight of the display device is divided into multiple partitions, and each control is dynamically changed according to the brightness information contained in the image information of the image in each control partition The PWM duty ratio of the driving signal of the partitioned backlight source, and thereby dynamically changing the brightness of each backlight partition. The bright part of the image corresponds to a higher backlight brightness, and the dark scene part of the image corresponds to a lower backlight brightness, thereby improving the contrast between the light and dark of the picture and improving the picture quality. Refer to FIG. 3 for details. In FIG. 3, the entire backlight is divided into 12 control zones, and each control zone has several pixels.

The control method of the backlight of the display device is the whole area control, which means that the entire backlight of the display device is controlled by a driving signal, and each backlight is dynamically changed according to the brightness information contained in the image information of the image in the control area The PWM duty ratio of the partitions, in turn, enables the brightness of each backlight partition to be dynamically changed.

Among them, according to the brightness information contained in the image information of the image in the backlight control area, the PWM duty ratio of each backlight zone is dynamically changed. It can be known that when the display device provides the backlight drive signal, the backlight drive signal The duty cycle of PWM is determined by the brightness information in the image information. In an embodiment, the display device determines that the brightness of a certain control area is 153, then the PWM duty cycle of the driving signal of the control area is.

The two driving modes of the backlight in the specific implementation will be separately described below.

1. The backlight source is controlled by zones.

In a specific implementation, when the backlight control mode of the display device is partition control; when the display device performs pulse bandwidth modulation on the drive signal of the backlight, each partition needs to be processed separately.

Determine the image display brightness according to the image information;

In a specific implementation, for any partition, when it is determined that the drive signal of the backlight controlled by the partition needs to be adjusted according to the image information of pixels on the image in the partition, the PWM frequency of the drive signal is increased.

In the above method, when the control method of the backlight of the display device is partition control, the display device will process each control partition of the backlight separately. At this time, the display device is based on the image of all pixels on the image in each partition When the information determines that the driving signal of the backlight controlled by the partition needs to be adjusted, the PWM frequency of the driving signal is increased. In this way, the display device can determine the PWM frequency of the corresponding increased drive signal and the corresponding PWM duty cycle for each control zone of the backlight source respectively, and then according to the determined PWM frequency of the increased drive signal and the The corresponding PWM duty ratio modulation generates a driving signal, so that the driving signal of the backlight source can be accurately controlled according to the brightness of each subarea.

When implementing the technical solution of the embodiment of the present application, the display device first determines whether the drive signal of the backlight needs to be adjusted according to the image information.

In an embodiment, for any partition, the display brightness of the first image of the partition is determined according to the image information of the pixels on the image in the partition.

In specific implementation, the display device first determines the display brightness of the first image of the partition according to the image information of all pixels on the image in the control partition, so as to determine whether the image displayed in the partition is a low-grayscale image according to the display brightness of the first image In order to further determine whether it is necessary to increase the PWM frequency of the driving signal to reduce the flickering feeling existing in the low gray scale display.

As shown in FIG. 4, an image in a control zone O has four pixels, and the RGB (red, green, blue, red, green, and blue) models represent image pixels as follows:

A (51, 22, 30), B (25, 33, 5), C (54, 45, 100), D (20, 15, 60);

The corresponding relationship between the RGB model represented by the image and the YUV (Luminance, Chrominance, Chroma, brightness, chroma, density) model is:

The brightness of one pixel: Y;

A pixel brightness :;

B pixel brightness :;

C pixel brightness :;

D pixel brightness :;

Control the brightness of the image display in partition O :.

After determining the display brightness of the first image in the control zone, the determined display brightness of the first image is compared with the set brightness threshold to determine whether it is necessary to adjust the drive signal of the backlight of the zone.

If the display brightness of the first image is not greater than a preset first brightness threshold, the display device determines that the driving signal of the backlight controlled by the partition needs to be adjusted.

In a specific implementation, the display device determines that the display brightness of the first image is not greater than the preset first brightness threshold, and determines that the low-grayscale image displayed in the partition has flickering, and it is necessary to adjust the driving signal of the backlight of the control partition to Reducing the flicker that exists when displaying low-grayscale images.

As shown in FIG. 4, an image in a control zone O has four pixels, and the image pixels represented by the RGB model are: A (51, 22, 30), B (25, 33, 5), C (54, 45, 100 ), D (20, 15, 60), and the determined image display brightness of the control zone O; the preset first brightness threshold is 50, then it can be determined by comparison that the first image display brightness of the control zone O is less than the set Therefore, it can be considered that the display image of the control zone O is a low-grayscale image, and there is a flickering phenomenon during the display. It is necessary to adjust the driving signal of the backlight of the control zone O to reduce the flickering when displaying the image.

When it is determined that the driving signal of the backlight of the control zone needs to be adjusted, the display device also needs to determine the modulation parameter of the driving signal.

The display device determines the magnification of the PWM frequency increase corresponding to the brightness of the first image according to the correspondence between the brightness of the first image display and the magnification of the increase of the PWM frequency; and then according to the determined magnification of the increase of the PWM frequency Increasing the PWM frequency of the driving signal; wherein the magnification of the PWM frequency is greater than or equal to 1.

In a specific implementation, when the control method of the backlight of the display device is partition control, after the display device determines the display brightness of the first image of each partition, the display brightness and the first The corresponding relationship between the brightness of the image display and the magnification of the PWM frequency increase determines the magnification of the PWM frequency of the drive signal corresponding to the zone, and increases the PWM frequency of the drive signal according to the determined magnification of the PWM frequency increase. In this way, the display device can increase the PWM frequency of the driving signal, so that the duration of the low level between the two high levels of the driving signal is reduced, thereby shortening the time of the dark screen between the two times the backlight is lit , To reduce the flicker that exists in low-grayscale display.

As shown in FIG. 4, an image in a control zone O has four pixels, and the image pixels represented by the RGB model are: A (51, 22, 30), B (25, 33, 5), C (54, 45, 100 ), D (20, 15, 60), and the determined image display brightness of the control zone O; the preset first brightness threshold is 50; the PWM frequency of the drive signal of the backlight of the current control zone is 120 Hz; given The corresponding relationship between the display brightness of the first image and the magnification of the PWM frequency increase is: if the drive signal of the backlight of the control zone needs to be adjusted, the PWM frequency of the drive signal of the backlight of the control zone is uniformly adjusted to 3 times the original PWM frequency.

When it is determined that the driving signal of the backlight of the control zone O is adjusted, the display device adjusts the PWM frequency of the driving signal of the backlight of the control zone O to 360 Hz.

Wherein, when the display brightness of the first image is not greater than the set first brightness threshold, the PWM frequency determined according to the correspondence between the display brightness of the first image and the PWM frequency is necessarily not less than the PWM frequency of the initial determination signal.

In addition, in addition to determining the increased PWM frequency of the driving signal of the backlight controlling the partition O, it is also necessary to determine the PWM duty of the driving signal of the backlight controlling the partition O.

For the above example, if the determined image display brightness of the control zone O is known, the PWM duty ratio of the drive signal of the control area is

That is, the PWM duty ratio of the driving signal for controlling the backlight of the partition O is 12%.

After the display device determines the PWM frequency corresponding to the brightness of the first image display and the PWM duty cycle of the corresponding drive signal, the display device will generate the PWM frequency of the drive signal and the PWM duty cycle of the drive signal according to the determined control zone The drive signal.

The display device generates the drive signal according to the determined PWM frequency and the PWM duty cycle modulation.

In specific implementation, after determining the PWM frequency corresponding to the first image display brightness of the control zone and the PWM duty cycle of the corresponding driving signal, the display device sends the current data calculated according to the determined PWM frequency and PWM duty cycle and sends To the PWM driving device; subsequently, the PWM driver adjusts the current according to the current data and the preset reference voltage Vref, and finally obtains the generated driving signal, and drives the backlight to emit light, and the display device displays an image. In this way, under the driving of the driving signal, the brightness of the backlight does not change, and the duration of the low level between the two high levels of the driving signal decreases, so that the time for the dark screen between the two times of the backlight to turn on becomes shorter In this way, the flickering feeling existing when the display device displays the low-grayscale image will be somewhat weakened, and the low-grayscale display effect of the display device will be improved to a certain extent.

2. The backlight source is controlled by the whole area.

In specific implementation, when the backlight of the display device is controlled in the entire area, the control area of the display device is the entire display area, and there is only one backlight drive signal. At this time, the display device will process the entire image display area.

Determine whether the drive signal of the backlight needs to be adjusted in the following ways:

In specific implementation, when the display device determines that it is necessary to adjust the drive signal of the backlight controlled by the entire area according to the image information of the pixels on the image in the entire control area, the PWM frequency of the drive signal is increased.

In the above method, when the control method of the backlight of the display device is the whole area control, the display device determines that the drive signal of the backlight control of the entire area needs to be adjusted according to the image information of all pixels on the image in the entire control area Time, the PWM frequency of the drive signal is increased. In this way, the display device can increase the PWM frequency of the drive signal and maintain the PWM duty cycle of the drive signal while maintaining the brightness unchanged when displaying the low grayscale image, so that the drive signal is between two high levels The duration of the low level is reduced, which in turn shortens the time of the dark screen between the two lightings of the backlight, thereby reducing the flickering feeling existing in the low gray scale display.

When implementing the technical solution of the embodiment of the present application, the display device first determines whether the drive signal of the backlight needs to be adjusted according to the image information of the image in the entire control area.

In an embodiment, the display device determines the display brightness of the second image of the entire control area according to the image information of pixels on the image within the entire control area.

During specific implementation, the display device first determines the display brightness of the second image of the entire control area according to the image information of all pixels on the image in the entire control area, so as to determine whether the image displayed by the display device is low gray according to the display brightness of the second image It can be further determined whether it is necessary to increase the PWM frequency of the driving signal of the backlight source to reduce the flicker existing in the low gray scale display.

For example, the image in the control area Q of the display device has n pixels, and the image pixels represented by the RGB model are:

(51, 22, 30), (25, 33, 5), (54, 45, 100), (20, 15, 60), ... (25, 5, 30);

According to the correspondence between the RGB model and the YUV model represented by the image:

The brightness of one pixel: Y;

Pixel brightness :;

(Brightness of pixels :;

Pixel brightness :;

...

Pixel brightness :;

The image display brightness of the entire control area Q :.

The number of pixels of the image in the control area of the display device is related to the image resolution and area of the display device.

Further, if the display brightness of the second image is not greater than a preset second brightness threshold, the display device determines that the driving signal of the backlight controlled by the entire area needs to be adjusted.

In specific implementation, after determining that the display brightness of the second image is not greater than the preset second brightness threshold, the display device determines that the image displayed by the current display device is a low grayscale image, and drives the display image with the existing backlight driving signal There is a flickering phenomenon, so the drive signal of the backlight needs to be adjusted to reduce flickering when displaying images.

For example: the display area of the display device consists of several pixels, and the calculated image display brightness; the preset second brightness threshold is 50, then the comparison determines that the second image display brightness of the entire control area of the backlight is less than the set The second brightness threshold, so the image displayed on the display can be a low-grayscale image, and flicker may occur during display. The drive signal of the backlight needs to be adjusted to reduce the flicker when displaying the image.

When it is determined that the drive signal of the backlight source needs to be adjusted, the display device also needs to determine the modulation parameter of the drive signal, so that the required drive signal of the backlight source can be generated according to the modulation parameter of the drive signal.

The display device determines a PWM frequency increase magnification corresponding to the second image display brightness of the entire control area according to the correspondence between the second image display brightness and the PWM frequency increase magnification; The magnification of increasing frequency increases the PWM frequency of the driving signal; wherein, the magnification of increasing the PWM frequency is greater than or equal to 1.

In the specific implementation, when the control mode of the backlight of the display device is the whole area control, after the display device determines the display brightness of the second image in the entire control area, the display device will determine the display brightness of the second image and the display brightness Correspondence between PWM frequency increasing magnifications The second image of the entire control area shows the PWM frequency increasing magnification corresponding to the brightness, and then the driving signal is increased according to the determined PWM frequency increasing magnification PWM frequency. In this way, the display device can increase the PWM frequency of the driving signal, so that the duration of the low level between the two high levels of the driving signal is reduced, thereby shortening the time of the dark screen between the two times the backlight is lit , To reduce the flicker that exists in low-grayscale display.

For example: the display area of the display device has several pixels, and the calculated image display brightness; the preset second brightness threshold is 50, the PWM frequency of the current backlight drive signal is 120 Hz; the given second image display brightness The corresponding relationship with the magnification that the PWM frequency increases is: if it is determined that the required driving signal of the backlight is adjusted, the PWM frequency of the driving signal of the backlight is uniformly adjusted to twice the original PWM frequency.

Then, since the calculated display brightness of the second image of the display device is less than the set second brightness threshold, it is determined that the driving signal of the backlight needs to be adjusted.

After determining that the drive signal of the backlight needs to be adjusted, the display device adjusts the PWM frequency of the drive signal of the backlight to 240 Hz.

Wherein, when the display brightness of the second image is not greater than the set second brightness threshold, the PWM frequency determined according to the correspondence between the display brightness of the second image and the PWM frequency is necessarily not less than the PWM frequency of the initial determination signal.

In addition to determining the PWM frequency of the increased backlight drive signal, it is also necessary to determine the PWM duty cycle of the backlight drive signal. The method for determining the PWM duty ratio of the driving signal of the backlight source is similar to that in the above embodiment, so it will not be described repeatedly.

After the display device determines the PWM frequency corresponding to the brightness of the second image display and the PWM duty cycle of the corresponding drive signal, the display device will generate a backlight according to the PWM frequency of the drive signal and the PWM duty cycle of the determined control zone Source drive signal.

The display device modulates the drive signal according to the determined PWM frequency and the PWM duty cycle.

In specific implementation, the display device determines the PWM frequency corresponding to the brightness of the first image display and the PWM duty cycle of the corresponding drive signal, generates a corresponding drive signal according to the determined PWM frequency and PWM duty, and drives the backlight to emit light, The display device displays the image. In this way, under the driving of the driving signal, the brightness of the backlight does not change, and the duration of the low level between the two high levels of the driving signal decreases, so that the time for the dark screen between the two times of the backlight to turn on becomes shorter In this way, the flickering feeling existing when the display device displays the low-grayscale image will be somewhat weakened, and the low-grayscale display effect of the display device will be improved to a certain extent.

In addition, since the low gray scale response of the TFT of the display panel is generally unsatisfactory, in the embodiments of the present application, while adjusting the driving signal of the backlight of the display device, the gray scale value of the image is compensated for gray scale Processing to improve low grayscale display characteristics.

For any pixel, the display device determines the grayscale value of the pixel in the control area according to the image information of the image in the control area; then, according to the correspondence between the grayscale value and the grayscale compensation value, the display area is determined The grayscale compensation value corresponding to the grayscale value of the pixel; finally, the grayscale value of the pixel in the control area is compensated according to the determined grayscale compensation value.

In specific implementation, the display device first determines the grayscale value of the control area according to the image information of the image in the control area, and then determines the corresponding grayscale value of the control area according to the correspondence between the preset grayscale value and the grayscale compensation value A gray scale compensation value, and compensates the gray scale value of the control area according to the determined gray scale compensation value. In this way, when the display effect of the low gray scale is not ideal, the corresponding relationship between the preset gray scale value and the gray scale compensation value can be used to compensate, and the gray scale value when the low gray scale image is displayed is increased to a certain extent, thereby making The displayed image details are clearer and the display effect is better.

For example: as shown in FIG. 5, the correspondence between the preset gray scale value and the gray scale compensation value, a pixel A in a certain control area of the display device is expressed in RGB mode as (20,10 , 55), the gray value of the pixel is;

It can be known from the correspondence between the gray scale value and the gray scale compensation value that the gray scale value of the pixel is lower than the preset gray scale value threshold, which belongs to the low gray scale. According to the relationship between the gray scale and the gray scale compensation value, The gray scale compensation value can be determined as 16;

After determining the compensation value, the original gray-scale inter-sex compensation for the pixel is compensated according to the determined gray-scale step value, and the compensated gray-scale value is 32.

Finally, the pixel is output with a gray scale value of 32.

As shown in FIG. 6, when the backlight is controlled by zones, embodiments of the present application provide a detailed flowchart of a method for modulating a backlight driving signal.

Step 600: For a control zone, the display device determines the brightness of each pixel in the control zone according to the image information of all pixels in the image in the control zone;

Step 601: The display device determines the display brightness of the first image of the control zone according to the determined brightness of each pixel in the control zone;

Step 602, the display device determines whether the display brightness of the first image is not greater than the set first brightness threshold, and if so,

steps

603 and 607 are performed; otherwise, step 606 is performed;

Step 603: The display device determines the PWM frequency increase magnification corresponding to the first image display brightness according to the determined first image display brightness and the correspondence between the first image display brightness and the frequency increase magnification;

Step 604: The display device increases the PWM frequency of the driving signal according to the determined magnification of the PWM frequency increase;

Step 605: The display device determines the PWM duty cycle of the driving signal;

Step 606: The display device generates a backlight driving signal according to the increased PWM frequency and the determined PWM duty ratio;

Step 607, the display device uses the generated driving signal to drive the backlight;

Step 608: For a pixel, the display device determines the grayscale value of each pixel in the control zone according to the image information of all pixels in the image in the control zone;

Step 609: The display device determines the gray scale compensation value corresponding to the gray scale value according to the correspondence between the gray scale value and the gray scale compensation value;

Step 610: The display device compensates the grayscale value of the pixels in the control zone according to the determined grayscale compensation value;

Step 611, the display device displays an image on the pixel according to the grayscale value after the compensation process;

Step 612, the display device determines the PWM duty cycle of the driving signal;

Step 613, the display device generates a driving signal according to the determined PWM duty ratio;

Step 614, the display device uses the generated driving signal to drive the backlight;

Step 615, the process ends.

As shown in FIG. 7, when the backlight is controlled by the entire area, the embodiment of the present application provides a detailed flowchart of a method for modulating a backlight driving signal.

Step 700, the display device determines the brightness of each pixel according to the image information of all pixels of the image in the control area;

Step 701: The display device determines the display brightness of the second image in the control area according to the determined brightness of each pixel;

Step 702, the display device determines whether the display brightness of the second image is not greater than the set second brightness threshold, and if so,

steps

703 and 707 are performed; otherwise, step 704 is performed;

Step 703: The display device determines the magnification of the PWM frequency corresponding to the second image display brightness according to the determined second image display brightness and the correspondence between the second image display brightness and the PWM frequency;

Step 704, the display device increases the PWM frequency of the driving signal according to the determined magnification of the PWM frequency increase;

Step 705, the display device determines the PWM duty cycle of the driving signal;

Step 706: The display device generates a backlight driving signal according to the increased PWM frequency and the determined PWM duty ratio;

Step 707, the display device uses the generated driving signal to drive the backlight;

Step 708: For one pixel, the display device determines the grayscale value of each pixel in the control area according to the image information of all pixels in the image in the entire control area;

Step 709: The display device determines the gray scale compensation value corresponding to the gray scale value according to the correspondence between the gray scale value and the gray scale compensation value;

Step 710: The display device compensates the grayscale value of the pixels in the control area according to the determined grayscale compensation value;

Step 711, the display device displays an image on the pixel according to the gray-scale value after the compensation process;

Step 712, the display device determines the PWM duty cycle of the driving signal;

Step 713, the display device generates a driving signal according to the determined PWM duty ratio;

Step 714, the display device uses the generated driving signal to drive the backlight;

Step 715, the process ends.

11 and FIG. 12 respectively show the waveforms of the PWM driving the backlight source provided in the prior art and the embodiments of the present application, the a) curve in the two figures corresponds to the PWM waveform diagram of the high grayscale image, b) the curve Corresponding to the PWM waveform of the low grayscale image, the duty cycle of the PWM determined from the image information of the high grayscale image is 60%, and the duty cycle of the PWM determined from the image information of the low grayscale image is 5%. The driving signal PWM frequency of the backlight of the two images in FIG. 11 is the same, both are 120HZ; the frequency of the PWM corresponding to the high-grayscale image in FIG. 12 is 120HZ, and the frequency of the PWM corresponding to the low-grayscale image is 240HZ. Double the fixed frequency 120HZ.

Based on the same inventive concept, an embodiment of the present application also provides a device for modulating a backlight driving signal, because the device is the display device in the method in the embodiment of the present application, and the principle of the device to solve the problem and the method Similar, so the implementation of the device can refer to the implementation of the method, and the repetition is not repeated here.

As shown in FIG. 8, an embodiment of the present application provides an apparatus for modulating a backlight driving signal. The apparatus includes a processing unit 800 and a storage unit 801, where the storage unit stores program codes, When the processing unit 800 executes, it causes the processing unit 800 to execute the following process:

When it is judged that the drive signal of the backlight needs to be adjusted according to the image information, the PWM frequency of the drive signal is increased; the drive signal is generated according to the determined PWM frequency and the PWM duty ratio determined by the image information.

Optionally, the processing unit 800 is specifically configured to determine whether the driving signal of the backlight needs to be adjusted in the following manner:

Optionally, the backlight is controlled by zones; the processing unit 800 is specifically used to:

For any partition, when it is determined that the drive signal of the backlight controlled by the partition needs to be adjusted according to the image information of all pixels on the image in the partition, the PWM frequency of the drive signal is increased;

Or the backlight is controlled by the whole area, and the processing unit 800 is specifically used to:

When it is determined that the drive signal of the backlight controlled by the entire area needs to be adjusted according to the image information of pixels on the image in the entire control area, increase the PWM frequency of the drive signal. .

Optionally, the processing unit 800 is specifically configured to: determine whether the driving signal of the backlight source needs to be adjusted in the following manner: the backlight source is a zone control,

For any partition, determine the display brightness of the first image of the partition based on the image information of all pixels on the image in the partition; if the display brightness of the first image is not greater than the preset first brightness threshold, determine Adjust the drive signal of the backlight controlled by the partition;

Or the backlight is controlled by the whole area,

Determine the display brightness of the second image of the entire control area according to the image information of the pixels on the image in the entire control area; The area-controlled backlight drive signal is adjusted.

Optionally, the processing unit 800 is specifically used to:

According to the corresponding relationship between the first image display brightness or the second image display brightness and the PWM frequency increase magnification, the PWM frequency increase magnification corresponding to the first image display brightness or the second image display brightness of the partition is determined; The ratio of increasing the PWM frequency increases the PWM frequency of the driving signal; wherein the ratio of increasing the PWM frequency is greater than or equal to 1.

Optionally, the processing unit 800 is also used to:

For any pixel, the grayscale value of the pixel in the control area is determined according to the image information of the image in the control area; according to the correspondence between the grayscale value and the grayscale compensation value, the pixel of the control area is determined The gray scale compensation value corresponding to the gray scale value; the gray scale value of the pixel in the control area is compensated according to the determined gray scale compensation value.

The embodiments of the present application provide a method for modulating a backlight driving signal and a display device, and the method is applicable to a terminal device. FIG. 9 shows a structural diagram of a possible terminal device. Referring to FIG. 9, the terminal device 900 includes a radio frequency (RF) circuit 910, a power supply 920, a processor 930, a memory 940, an input unit 950, a display unit 960, a communication interface 970, and wireless fidelity ( Wireless (Fidelity, WiFi) module 980 and other components. Those skilled in the art can understand that the structure of the terminal device shown in FIG. 9 does not constitute a limitation on the terminal device. The terminal device provided in this embodiment of the present application may include more or fewer components than shown, or a combination of Components, or different component arrangements. In an embodiment, the terminal device is a television.

The following describes each component of the terminal device 900 in detail with reference to FIG. 9:

The RF circuit 910 can be used for receiving and sending data during communication. Generally, the RF circuit 910 includes but is not limited to an antenna, at least one amplifier, a transceiver, a coupler, a low noise amplifier (LNA), a duplexer, and the like.

In addition, the RF circuit 910 can also communicate with other devices through a wireless communication network. The wireless communication may use any communication standard or protocol, including but not limited to Global System of Mobile (GSM), General Packet Radio Service (GPRS), and Code Division Multiple Access (Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), Long Term Evolution (LTE), E-mail, Short Message Service (SMS), etc.

WiFi technology is a short-distance wireless transmission technology. The terminal device 900 can be connected to an access point (Access Point, AP) through a WiFi module 980, so as to realize access to a data network. The WiFi module 980 can be used for receiving and sending data during communication.

The terminal device 900 may physically connect with other devices through the communication interface 970. Optionally, the communication interface 970 and the communication interface of the other device are connected by a cable to implement data transmission between the terminal device 900 and other devices.

Since in the embodiment of the present application, the terminal device 900 can implement a communication service, the terminal device 900 needs to have a data transmission function, that is, the terminal device 900 needs to include a communication module inside. Although FIG. 9 shows the RF circuit 910, the WiFi module 980, and the communication interface 970 and other communication modules, it can be understood that at least one of the above-mentioned components or other uses exist in the terminal device 900 A communication module (such as a Bluetooth module) for implementing communication for data transmission.

For example, when the terminal device 900 is a mobile phone, the terminal device 900 may include the RF circuit 910 and may also include the WiFi module 980; when the terminal device 900 is a computer, the terminal device 900 may Including the communication interface 970, the WiFi module 980 may also be included; when the terminal device 900 is a tablet computer, the terminal device 900 may include the WiFi module.

The memory 940 may be used to store software programs and modules. The processor 930 runs software programs and modules stored in the memory 940 to execute various functional applications and data processing of the terminal device 900.

Optionally, the memory 940 may mainly include a program storage area and a data storage area. The storage program area may store an operating system, various application programs (such as communication applications), and face recognition modules, etc .; the storage data area may store data created according to the use of the terminal device (such as various pictures and video files Multimedia files, and face information templates), etc.

In addition, the memory 940 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other volatile solid-state storage devices.

The input unit 950 may be used to receive numeric or character information input by a user, and generate key signal input related to user settings and function control of the terminal device 900.

Optionally, the input unit 950 may include a touch panel 951 and other input devices 952.

The touch panel 951, also known as a touch screen, can collect user's touch operations on or near it (for example, the user uses any suitable objects or accessories such as fingers, stylus, etc. on the touch panel 951 or on Operation near the touch panel 951), and drive the corresponding connection device according to a preset program. Optionally, the touch panel 951 may include a touch detection device and a touch controller. Among them, the touch detection device detects the user's touch orientation, and detects the signal brought by the touch operation, and transmits the signal to the touch controller; the touch controller receives touch information from the touch detection device and converts it into contact coordinates, and then sends To the processor 930, and can receive the command sent by the processor 930 and execute it. In addition, the touch panel 951 may be implemented in various types such as resistive, capacitive, infrared, and surface acoustic waves.

Optionally, the other input devices 952 may include, but are not limited to, one or more of a physical keyboard, function keys (such as volume control keys, switch keys, etc.), trackball, mouse, joystick, and so on.

The display unit 960 may be used to display information input by the user or information provided to the user and various menus of the terminal device 900. The display unit 960 is a display system of the terminal device 900, and is used to present an interface and realize human-computer interaction.

The display unit 960 may include a display panel 961. Optionally, the display panel 961 may be configured in the form of a liquid crystal display (Liquid Crystal) (LCD), an organic light-emitting diode (Organic Light-Emitting Diode, OLED), or the like.

Further, the touch panel 951 may cover the display panel 961, and when the touch panel 951 detects a touch operation on or near it, it is transmitted to the processor 930 to determine the type of touch event, Subsequently, the processor 930 provides corresponding visual output on the display panel 961 according to the type of touch event.

Although in FIG. 9, the touch panel 951 and the display panel 961 are implemented as two independent components to realize the input and input functions of the terminal device 900, in some embodiments, the The touch panel 951 is integrated with the display panel 961 to implement input and output functions of the terminal device 900.

The processor 930 is a control center of the terminal device 900, connects various components using various interfaces and lines, and executes or executes software programs and / or modules stored in the memory 940, and calls stored in the The data in the memory 940 performs various functions and process data of the terminal device 900, thereby realizing various services based on the terminal device.

Optionally, the processor 930 may include one or more processing units. Optionally, the processor 930 may integrate an application processor and a modem processor, where the application processor mainly processes an operating system, a user interface, an application program, and the like, and the modem processor mainly processes wireless communication. It can be understood that the foregoing modem processor may not be integrated into the processor 930.

The terminal device 900 further includes a power supply 920 (such as a battery) for powering various components. Optionally, the power supply 920 may be logically connected to the processor 930 through a power management system, so that functions such as charging, discharging, and power consumption are managed through the power management system.

Although not shown, the terminal device 900 may further include at least one sensor, audio circuit, etc., which will not be repeated here.

The memory 940 may store the same program code as the storage unit 801, and when the program code is executed by the processor 930, the processor 930 implements all functions of the processing unit 800.

As shown in FIG. 10, an embodiment of the present application provides a device for modulating a backlight driving signal. The device includes:

The determining unit 1000 is configured to increase the PWM frequency of the driving signal when generating the driving signal;

The modulation unit 1001 is configured to modulate the driving signal according to the determined PWM frequency and the PWM duty ratio determined by image information.

Optionally, the determination unit 1000 is specifically configured to determine whether the driving signal of the backlight needs to be adjusted in the following manner:

Determine the image display brightness according to the image information; if the image display brightness is not greater than the preset brightness threshold, determine that the backlight driving signal needs to be adjusted.

Optionally, the backlight is controlled by a zone, and the determining unit 1000 is specifically used to:

For any partition, when it is determined that the drive signal of the backlight controlled by the partition needs to be adjusted according to the image information of pixels on the image in the partition, the PWM frequency of the drive signal is increased;

Or the backlight is controlled by the whole area, and the determination unit 1000 is specifically used for:

Optionally, the determining unit 1000 is specifically configured to: determine whether the driving signal of the backlight source needs to be adjusted in the following manner: the backlight source is a zone control,

Or the backlight is controlled by the whole area,

Optionally, the determining unit 1000 is specifically used to:

Optionally, the device also includes:

The compensation unit 1002 is used to determine the gray scale value of the pixel in the control area according to the image information of the image in the control area for any pixel; determine the control area according to the correspondence between the gray scale value and the gray scale compensation value The grayscale compensation value corresponding to the grayscale value of the pixel in the; the grayscale value of the pixel in the control area is compensated according to the determined grayscale compensation value.

The embodiment of the present application further provides a storage medium readable by a computing device for a method of modulating a backlight driving signal, that is, content is not lost after power off. The storage medium stores a software program, including program code, and when the program code runs on a computing device, the software program can be implemented by any one of the backlight sources in the embodiments of the present application when read and executed by one or more processors The scheme of signal modulation.

The present application is described above with reference to block diagrams and / or flowcharts showing methods, apparatuses (systems) and / or computer program products according to embodiments of the present application. It should be understood that one block of the block diagram and / or flowchart illustration and a combination of blocks of the block diagram and / or flowchart illustration can be implemented by computer program instructions. These computer program instructions may be provided to a general-purpose computer, a dedicated computer processor, and / or other programmable data processing devices to produce a machine, such that instructions executed via the computer processor and / or other programmable data processing devices are created for A method to implement the functions / actions specified in the block diagram and / or flowchart block.

Correspondingly, the application can also be implemented in hardware and / or software (including firmware, resident software, microcode, etc.). Further, the present application may take the form of a computer-usable or computer-readable storage medium on a computer-readable storage medium with computer-usable or computer-readable program code implemented in the medium to be used by an instruction execution system or Used in conjunction with an instruction execution system. In the context of this application, a computer-usable or computer-readable medium may be any medium that can contain, store, communicate, transmit, or transmit a program for use by an instruction execution system, apparatus, or device, or in conjunction with an instruction execution system, Use of device or equipment.

Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. In this way, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these modifications and variations.

Claims

A method for modulating backlight drive signals, characterized in that the method includes:

When judging that the drive signal of the backlight needs to be adjusted according to the image information, increase the pulse width modulation PWM frequency of the drive signal;

The drive signal is modulated according to the determined PWM frequency and the PWM duty cycle determined by the image information.
The method for modulating a backlight driving signal according to claim 1, wherein it is determined whether the driving signal of the backlight needs to be adjusted in the following manner:

Determine the image display brightness according to the image information;

If the image display brightness is not greater than the preset brightness threshold, it is determined that the driving signal of the backlight needs to be adjusted.
The method for modulating a backlight driving signal according to claim 1, wherein it is determined whether the driving signal of the backlight needs to be adjusted in the following manner:

Determine the PWM duty cycle according to the image information;

If the PWM duty cycle is not greater than the preset duty cycle threshold, it is determined that the drive signal of the backlight needs to be adjusted.
The method of claim 1, wherein:

When it is judged that the drive signal of the backlight source needs to be adjusted according to the image information, increasing the PWM frequency of the drive signal includes: the backlight source is zoned control,

For any partition, when it is determined that the drive signal of the backlight controlled by the partition needs to be adjusted according to the image information of pixels on the image in the partition, the PWM frequency of the drive signal is increased;

Or the backlight is controlled by the whole area,

When judging that the drive signal of the backlight needs to be adjusted according to the image information, increasing the PWM frequency of the drive signal includes:

When it is determined that the drive signal of the backlight controlled by the entire area needs to be adjusted according to the image information of pixels on the image in the entire control area, increase the PWM frequency of the drive signal.
The method according to claim 2, characterized in that it is judged whether the driving signal of the backlight source needs to be adjusted in the following manner: the backlight source is a zone control,

For any partition, the display brightness of the first image of the partition is determined according to the image information of the pixels on the image in the partition;

If the display brightness of the first image is not greater than a preset first brightness threshold, it is determined that the driving signal of the backlight controlled by the partition needs to be adjusted;

Or the backlight is controlled by the whole area,

Determining the display brightness of the second image of the entire control area according to the image information of pixels on the image in the entire control area;

If the display brightness of the second image is not greater than the preset second brightness threshold, it is determined that the driving signal of the backlight controlled by the entire area needs to be adjusted.
The method of claim 5, wherein the increasing the PWM frequency of the driving signal comprises:

Determine the magnification ratio of the PWM frequency corresponding to the first image display brightness or the second image display brightness according to the correspondence between the first image display brightness or the second image display brightness and the PWM frequency increase ratio;

Increasing the PWM frequency of the drive signal according to the determined magnification of the PWM frequency increase;

Wherein, the increase rate of the PWM frequency is greater than or equal to 1.
The method according to any one of claims 1 to 6, wherein the method further comprises:

For any pixel, the grayscale value of the pixel in the control area is determined according to the image information of the image in the control area;

According to the correspondence between the gray scale value and the gray scale compensation value, determine the gray scale compensation value corresponding to the gray scale value of the pixel in the control area;

The grayscale value of the pixel in the control area is compensated according to the determined grayscale compensation value.
A device for modulating backlight driving signals, characterized in that the device comprises:

The determining unit is configured to increase the PWM frequency of the driving signal when it is necessary to adjust the driving signal of the backlight according to the image information;

The modulation unit is configured to modulate the driving signal according to the determined PWM frequency and the PWM duty ratio determined by the image information.
The device according to claim 8, wherein the determining unit is specifically configured to determine whether the driving signal of the backlight needs to be adjusted in the following manner:

Determine the image display brightness according to the image information;

If the image display brightness is not greater than the preset brightness threshold, it is determined that the driving signal of the backlight needs to be adjusted.
The device according to claim 8, wherein the backlight is controlled by a zone, and the determination unit is specifically configured to:

For any partition, when it is determined that the drive signal of the backlight controlled by the partition needs to be adjusted according to the image information of pixels on the image in the partition, the PWM frequency of the drive signal is increased;

Or the backlight is controlled by the whole area, and the determination unit is specifically used for:

When it is determined that the driving signal of the backlight controlled by the entire area needs to be adjusted according to the image information of pixels on the image in the entire control area, the PWM frequency of the driving signal is increased.
The device according to claim 9, wherein the determining unit is specifically configured to determine whether the driving signal of the backlight source needs to be adjusted in the following manner: the backlight source is controlled by a partition, and is directed to any partition , Determine the display brightness of the first image of the partition according to the image information of the pixels on the image in the partition;

If the display brightness of the first image is not greater than a preset first brightness threshold, it is determined that the driving signal of the backlight controlled by the partition needs to be adjusted;

Or the backlight is controlled by the whole area,

Determining the display brightness of the second image of the entire control area according to the image information of pixels on the image in the entire control area;

If the display brightness of the second image is not greater than the preset second brightness threshold, it is determined that the driving signal of the backlight controlled by the entire area needs to be adjusted.
The apparatus according to claim 8, wherein the determining unit is specifically configured to:

According to the corresponding relationship between the first image display brightness or the second image display brightness and the PWM frequency increase magnification, the PWM frequency increase magnification corresponding to the first image display brightness or the second image display brightness is determined; according to the determined The magnification of increasing the PWM frequency increases the PWM frequency of the driving signal; wherein, the magnification of increasing the PWM frequency is greater than or equal to 1.
The device according to any one of claims 8 to 12, wherein the device further comprises:

The compensation unit is used to determine the gray scale value of the pixel in the control area according to the image information of the image in the control area for any pixel point; determine the control area according to the correspondence between the gray scale value and the gray scale compensation value The gray-scale compensation value corresponding to the gray-scale value of the pixel point; the gray-scale value of the pixel point in the control area is compensated according to the determined gray-scale compensation value.
A display device, characterized in that the display device adopts the method for modulating the backlight drive signal according to any one of claims 1-7 or includes the modulation for the backlight drive signal according to any one of claims 8-13 installation.
A TV set, characterized in that the TV set uses the method for modulating the backlight drive signal according to any one of claims 1-7 or includes the modulation for the backlight drive signal according to any one of claims 8-13 installation.