CN111210778A

CN111210778A - Method and device for modulating backlight source driving signal

Info

Publication number: CN111210778A
Application number: CN201811396664.9A
Authority: CN
Inventors: 张玉欣; 杜强; 董晓滨
Original assignee: Hisense Visual Technology Co Ltd
Current assignee: Hisense Visual Technology Co Ltd
Priority date: 2018-11-22
Filing date: 2018-11-22
Publication date: 2020-05-29
Also published as: WO2020103887A1

Abstract

The invention discloses a method and a device for modulating a backlight source driving signal, which are used for solving the problem that a liquid crystal display in the prior art has flicker feeling when displaying a low-gray-scale image. In the embodiment of the invention, when the display device judges that the driving signal of the backlight needs to be adjusted, the PWM frequency of the driving signal is increased; and then modulates a driving signal for driving the backlight according to the determined PWM frequency and the PWM duty determined by the image information. Therefore, when the low gray scale image is displayed, the display device can keep the brightness of the image in the control area corresponding to the low gray scale image unchanged, and simultaneously increase the PWM frequency of the driving signal in the control area, so that the low level duration between two times of high levels of the driving signal is reduced, and further the time of dark screen between two times of lightening of the backlight source is shortened, thereby reducing the flicker feeling existing when the low gray scale image is displayed.

Description

Method and device for modulating backlight source driving signal

Technical Field

The invention relates to the technical field of display, in particular to a method and a device for modulating a backlight source driving signal.

Background

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

The conventional dynamic backlight control technique divides the backlight of the liquid crystal display into a plurality of partitions, determines the luminance of each partition according to the luminance information included in the image information, and dynamically changes the luminance of each backlight partition according to the determined luminance. The bright part of the image corresponds to high backlight brightness, and the dark scene part of the image corresponds to low backlight brightness, so that the contrast of the image can be improved, and the image quality can be improved.

In the prior art, when a liquid crystal display with a dynamic backlight control function displays a low gray scale image, a PWM (Pulse Width Modulation) duty ratio of a backlight driving signal is relatively low, which can be understood as that a duty ratio of a backlight on time is relatively low in a PWM period of a backlight driving signal, and most of the backlight on time is in an off state. Therefore, when displaying low gray scale images, the backlight source is turned off for too long, and the images have a flickering feeling.

However, with the popularization of liquid crystal displays, liquid crystal displays are applied to special fields such as aerospace and vehicle-mounted, and in these special fields, the demand for display effect of a display device in low gray scale display is very high. In addition, when the television is required to have a high image quality, the low gray scale representation capability is also considered.

As described above, the conventional liquid crystal display device may have a flicker feeling when displaying a low gray scale image.

Disclosure of Invention

The invention provides a method and a device for modulating a backlight source driving signal, which are used for solving the problem that a liquid crystal display in the prior art has flicker feeling when displaying a low-gray-scale image.

The embodiment of the invention provides a method for modulating a backlight source driving signal, which comprises the following steps:

when judging that the driving signal of the backlight source needs to be adjusted according to the image information, increasing the PWM frequency of the driving signal;

modulating the driving signal according to the determined PWM frequency and the PWM duty ratio determined by the image information.

According to the method, when the driving signal of the backlight source needs to be adjusted according to the image information, the PWM frequency of the driving signal is increased; and then modulating a driving signal of the backlight according to the determined PWM frequency and the PWM duty determined by the image information. Therefore, when the low gray scale image is displayed, the display device determines the corresponding PWM duty ratio of the driving signal of the control area corresponding to the low gray scale image according to the image information, and simultaneously increases the PWM frequency of the driving signal of the control area corresponding to the low gray scale image.

In one possible embodiment, whether the driving signal of the backlight needs to be adjusted is determined by:

determining image display brightness according to the image information;

and if the image display brightness is not greater than the preset brightness threshold value, determining that the driving signal of the backlight source needs to be adjusted.

Firstly, determining image display brightness according to image information; and then comparing the determined image display brightness with a preset brightness threshold, if the image display brightness is not greater than the preset brightness threshold, determining that the image corresponding to the image information is a low-gray-scale image, and determining that the driving signal of the backlight source needs to be adjusted.

determining a PWM duty ratio according to the image information;

and if the PWM duty ratio is not larger than a preset duty ratio threshold value, determining that the driving signal of the backlight source needs to be adjusted.

According to the method, besides the fact that the driving signal of the backlight source needs to be adjusted is determined according to the image display brightness determined by the image information, the PWM duty ratio can be determined according to the image information, then the determined PWM duty ratio is compared with the preset duty ratio threshold value, if the PWM duty ratio is determined to be not larger than the preset duty ratio threshold value, the image corresponding to the image information can be determined to be a low-gray-scale image, and the driving signal of the backlight source needs to be adjusted.

In a possible embodiment, the increasing the PWM frequency of the driving signal when it is determined that the driving signal of the backlight needs to be adjusted according to the image information includes: the backlight source is controlled in a partition mode,

and aiming at any one subarea, when the driving signal of the backlight source controlled by the subarea needs to be adjusted according to the image information of the pixel points on the image in the subarea, increasing the PWM frequency of the driving signal.

According to the method, when the control mode of the backlight source of the display device is the partition control, the display device can respectively process each control partition of the backlight source, and at the moment, when the display device determines that the driving signal of the partition-controlled backlight source needs to be adjusted according to the image information of all pixel points on the image in each partition, the PWM frequency of the driving signal is increased. In this way, the display device can respectively determine the PWM frequency of the increased driving signal and the PWM duty ratio corresponding to the driving signal for each control partition of the backlight source, and then modulate the driving signal according to the determined PWM frequency of the increased driving signal and the corresponding PWM duty ratio, so that the driving signal of the backlight source can be more flexibly and accurately controlled according to the brightness of each partition.

In one possible embodiment, whether the driving signal of the backlight needs to be adjusted is determined by: the backlight source is controlled in a partition mode,

aiming at any one subarea, determining the first image display brightness of the subarea according to the image information of pixel points on the image in the subarea;

and if the display brightness of the first image is not greater than a preset first brightness threshold value, determining that the driving signal of the backlight source controlled by the subareas needs to be adjusted.

In the method, when the control mode of the backlight of the display device is the partition control, the display device processes each partition. And aiming at any one subarea, the display device determines the first image display brightness of the subarea according to the image information of all pixel points on the image in the subarea, and then determines that the driving signal of the backlight source controlled by the subarea needs to be adjusted when the first image display brightness is not greater than a preset brightness threshold value, so that the flicker feeling existing in the low-gray-scale display can be reduced by increasing the PWM frequency of the driving signal.

In one possible embodiment, the increasing the PWM frequency of the driving signal includes:

determining the multiplying power of the PWM frequency increase corresponding to the first image display brightness according to the corresponding relation between the first image display brightness and the multiplying power of the PWM frequency increase;

increasing the PWM frequency of the driving signal according to the determined multiplying power of the PWM frequency;

wherein, the multiplying factor of the PWM frequency increase is more than or equal to 1.

In the method, when the control mode of the backlight source of the display device is the partition control, after the display device determines the first image display brightness of each partition, the multiplying factor of the PWM frequency increase of the driving signal corresponding to the partition is determined according to the determined first image display brightness of each control partition and the corresponding relation between the first image display brightness and the multiplying factor of the PWM frequency increase, and the PWM frequency of the driving signal is increased according to the determined multiplying factor of the PWM frequency increase. Therefore, the display device can reduce the duration of the low level between two times of high levels of the driving signal by increasing the PWM frequency of the driving signal, so that the time of dark screen between two times of lightening of the backlight source is shortened, and the flicker feeling existing in the low gray scale display process is reduced accordingly.

In one possible embodiment, the backlight is controlled for the entire area;

when determining that the driving signal of the backlight source needs to be adjusted according to the image information, increasing the PWM frequency of the driving signal comprises:

and when determining that the driving signal of the backlight source controlled by the whole area needs to be adjusted according to the image information of the pixel points on the image in the whole control area, increasing the PWM frequency of the driving signal.

According to the method, when the control mode of the backlight source of the display device is whole-area control, the display device determines that the driving signal of the backlight source controlled by the whole area needs to be adjusted according to the image information of all pixel points on the image in the whole control area, and the PWM frequency of the driving signal is increased. Therefore, when the display device displays a low gray scale image, the PWM frequency of the driving signal of the whole backlight source can be increased, so that the low level duration between two times of high levels of the driving signal is reduced on the premise of maintaining the unchanged brightness, the time of dark screen between two times of lightening of the backlight source is shortened, and the flicker feeling existing in the low gray scale display is reduced accordingly.

In one possible embodiment, the display device determines whether the driving signal of the backlight needs to be adjusted by: the backlight source is controlled in the whole area,

determining second image display brightness of the whole control area according to image information of pixel points on an image in the whole control area;

and if the display brightness of the second image is not greater than a preset second brightness threshold value, determining that the driving signal of the backlight source controlled by the whole area needs to be adjusted.

According to the method, when the control mode of the backlight source of the display device is whole-area control, the display device determines the second image display brightness of the whole control area according to the image information of all pixel points on the image in the whole control area, and then determines that the driving signal of the backlight source controlled by the whole area needs to be adjusted when the second image display brightness is not greater than a preset second brightness threshold value, so that the flicker feeling existing in low gray scale display can be reduced by increasing the PWM frequency of the driving signal of the whole area.

determining the multiplying power of the PWM frequency increase corresponding to the second image display brightness according to the corresponding relation between the second image display brightness and the multiplying power of the PWM frequency increase;

In the method, when the control mode of the backlight source of the display device is full-area control, after the display device determines the second image display brightness of the whole control area, the multiplying factor of the PWM frequency increase corresponding to the second image display brightness of the whole control area is determined according to the determined second image display brightness and the corresponding relation between the second image display brightness and the multiplying factor of the PWM frequency increase, and then the PWM frequency of the driving signal is increased according to the determined multiplying factor of the PWM frequency increase. Therefore, the display device can reduce the duration of the low level between two times of high levels of the driving signal by increasing the PWM frequency of the driving signal, so that the time of dark screen between two times of lightening of the backlight source is shortened, and the flicker feeling existing in the low gray scale display process is reduced accordingly.

In a possible implementation manner, for any pixel point, determining a gray-scale value of the pixel point in the control area according to image information of an image in the control area;

determining a gray scale compensation value corresponding to the gray scale value of the pixel point in the control area according to the corresponding relation between the gray scale value and the gray scale compensation value;

and compensating the gray scale value of the pixel point in the control area according to the determined gray scale compensation value.

According to the method, aiming at any pixel point, when the display device displays an image, the gray-scale value of the pixel point in the control area can be determined according to the image information of the image in the control area; and then determining a corresponding gray scale compensation value according to the corresponding relation between the gray scale value and the gray scale compensation value, further performing gray scale compensation according to the determined gray scale value of the pixel point, and displaying according to the compensated gray scale value, so that the details of the displayed low-gray-scale image are clearer, and a better display effect is obtained.

In a second aspect, an embodiment of the present invention further provides a device for modulating a backlight driving signal, including: a processing unit and a storage unit, the display device having functions to implement the embodiments of the first aspect.

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

In addition, for technical effects brought by any one implementation manner of the second aspect to the third aspect, reference may be made to technical effects brought by different implementation manners of the first aspect, and details are not described here.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

FIG. 1A is a schematic block diagram of a dynamic backlight control according to an embodiment of the present invention;

FIG. 1B is a schematic block diagram of a multi-channel backlight driving scheme for dynamic partition control of a backlight source according to an embodiment of the present invention;

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

FIG. 3 is a schematic view of control partitions when the backlight source is controlled in partitions according to an embodiment of the present disclosure;

FIG. 4 is a diagram of a control partition including 4 pixels according to an embodiment of the present invention;

FIG. 5 is a diagram illustrating a function for gray level compensation according to an embodiment of the present invention;

fig. 6 is a detailed flowchart of a method for modulating a backlight driving signal when the backlight is controlled in a partition manner according to an embodiment of the present invention;

fig. 7 is a detailed flowchart of a method for modulating a backlight driving signal when the backlight is controlled in a partition manner according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of a device for modulating a driving signal of a backlight according to a first embodiment of the present invention;

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

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

FIG. 11 is a waveform diagram of PWM driving a backlight according to the prior art;

fig. 12 is a waveform diagram of PWM for driving a backlight according to an embodiment of the present invention.

Detailed Description

The embodiment of the invention relates to a method for performing hybrid dynamic modulation on a driving signal of a backlight source of a display device, and is applied to a scene for controlling the driving signal of the backlight source of the display device as shown in fig. 1A-1B. In the embodiment of the invention, the display device determines the corresponding PWM duty ratio of the driving signal of the control area corresponding to the low gray-scale image according to the image information, and simultaneously generates the driving signal of the backlight source by increasing the PWM frequency of the driving signal of the backlight source and modulating according to the PWM frequency and the PWM duty ratio so as to drive the backlight source. Therefore, the brightness of the backlight source can be ensured to be unchanged; meanwhile, the low level duration between two times of high levels of the driving signal is reduced, so that the dark screen time between two times of lightening of the backlight source is shortened, and the flicker feeling existing in low gray scale display is reduced. In addition, when the flicker feeling existing in the low gray scale display is reduced by increasing the PWM frequency of the driving signal of the backlight source, the display device can also perform gray scale compensation on the determined gray scale value through the corresponding relation between the preset gray scale value and the gray scale compensation value so as to obtain better display effect.

When the driving signal of the backlight source is generated by modulation, 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 meets the determined PWM duty ratio.

In the implementation of the invention, when displaying low gray scale images, the PWM frequency of the driving signal of the backlight source is increased to reduce the low level duration between two times of high levels of the driving signal, so that the dark screen time between two times of lightening of the backlight source is shortened, and the flicker feeling existing in the low gray scale image display is reduced. At this time, the driving signal is required to be generated according to the increased PWM frequency and the determined PWM duty ratio modulation at the same time.

When the driving signal of the backlight source is generated through modulation, the backlight processing unit of the display device sends current data calculated according to the PWM frequency and the determined PWM duty ratio to the PWM driver, the PWM driver adjusts the current according to the current data and the preset reference voltage Vref, and finally the driving signal generated through modulation according to the PWM frequency and the PWM duty ratio is obtained.

In order to make the objects, technical solutions and advantages of the present invention clearer, the present invention will be described in further detail with reference to the accompanying drawings, and it is apparent that the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. 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.

As shown in fig. 2, an embodiment of the present invention provides a method for modulating a backlight driving signal, where the method includes:

According to the method, when the driving signal of the backlight source needs to be adjusted according to the image information, the PWM frequency of the driving signal is increased; the driving signal is then modulated according to the determined PWM frequency and the PWM duty cycle determined by the image information. Therefore, when the low gray scale image is displayed, the display device determines the corresponding PWM duty ratio of the driving signal of the control area corresponding to the low gray scale image according to the image information, and simultaneously increases the PWM frequency of the driving signal of the control area corresponding to the low gray scale image.

In a specific implementation, the display device first needs to determine, according to the image information, that the driving signal of the backlight needs to be adjusted.

Optionally, the display device determines whether the driving signal of the backlight source needs to be adjusted by the following method:

determining image display brightness according to the image information; and if the image display brightness is not greater than the preset brightness threshold value, determining that the driving signal of the backlight source needs to be adjusted.

In the method, a display device firstly determines the image display brightness corresponding to an image to be displayed according to the image information of the image; and then comparing the determined image display brightness with a preset brightness threshold, if the image display brightness is not greater than the preset brightness threshold, determining that the image corresponding to the image information is a low-gray-scale image, and determining that the driving signal of the backlight source needs to be adjusted.

Further, if the image display brightness is greater than the preset brightness threshold, the drive signal of the backlight source is not required to be adjusted by default, the PWM frequency of the drive signal is not required to be increased, the frequency is not switched, and the drive signal is generated by modulating with a fixed frequency and a determined PWM duty ratio.

The value of the duty ratio can reflect the brightness degree of the image, the duty ratio of the PWM corresponding to the low gray-scale image is small, and the duty ratio of the PWM corresponding to the high gray-scale image is high.

Therefore, optionally, the display device may further determine whether the driving signal of the backlight needs to be adjusted by:

determining a duty ratio according to the image information; and if the duty ratio is not larger than a preset duty ratio threshold value, determining that the driving signal of the backlight source needs to be adjusted.

If the duty ratio is larger than the preset duty ratio threshold value, the drive signal of the backlight source is not required to be adjusted by default, the PWM frequency of the drive signal is not required to be increased, the frequency is not switched, and the drive signal is generated by adopting fixed frequency and determined PWM duty ratio modulation.

The judgment mode utilizing the duty ratio is suitable for whole-area control and is also suitable for partition control, and the determination of the duty ratio can be determined according to the existing determination mode of the duty ratio, for example, the determination can be performed through the brightness of an image and a prestored mapping table.

The following description is made in terms of the manner of determining the image display luminance.

The control mode of the backlight source of the display device can be subarea control or whole area control.

The control method of the backlight source of the display device is partition control, which means that the backlight source of the display device is divided into a plurality of partitions, and the PWM duty ratio of the driving signal of the backlight source of each control partition is dynamically changed according to the brightness information contained in the image information of the image in each control partition, so that the brightness of each backlight partition is dynamically changed. The bright part of the image corresponds to high backlight brightness, and the dark scene part of the image corresponds to low backlight brightness, so that the contrast of the image can be improved, and the image quality can be improved. Specifically, referring to fig. 3, in fig. 3, the whole backlight source is divided into 12 control partitions, and each control partition has a plurality of pixels.

The control mode of the backlight source of the display device is whole-area control, which means that the whole backlight source of the display device is controlled by one driving signal, and the PWM duty ratio of each backlight partition is dynamically changed according to the brightness information contained in the image information of the image in the control area, so that the brightness of each backlight partition is dynamically changed.

The display device dynamically changes the PWM duty ratio of each backlight partition according to the brightness information contained in the image information of the image in the backlight control area, and when the display device provides the driving signal of the backlight, the PWM duty ratio of the driving signal of the backlight is determined by the brightness information in the image information. For example: when the display device determines that the luminance of a certain control region is 153, the duty ratio of the PWM of the drive signal of the control region is 153 ÷ 255 × 100% >, which is 60%.

Two driving modes of the backlight in the embodiment will be separately described.

Firstly, the backlight source is controlled in a partition mode.

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

Optionally, whether the driving signal of the backlight needs to be adjusted is determined by the following method:

determining image display brightness according to the image information;

In specific implementation, optionally, for any one partition, when it is determined that the driving signal of the backlight source controlled by the partition needs to be adjusted according to the image information of the pixel point on the image in the partition, the PWM frequency of the driving signal is increased.

According to the method, when the control mode of the backlight source of the display device is the partition control, the display device can respectively process each control partition of the backlight source, and at the moment, when the display device determines that the driving signal of the partition-controlled backlight source needs to be adjusted according to the image information of all pixel points on the image in each partition, the PWM frequency of the driving signal is increased. In this way, the display device can respectively determine the corresponding increased PWM frequency and the corresponding PWM duty ratio of the driving signal for each control partition of the backlight source, and then generate the driving signal according to the determined increased PWM frequency and the corresponding PWM duty ratio modulation of the driving signal, so that the driving signal of the backlight source can be more flexibly and accurately controlled according to the brightness of each partition.

Further, when implementing the technical solution of the embodiment of the present invention, the display device first determines whether the driving signal of the backlight source needs to be adjusted according to the image information.

Optionally, for any one partition, the first image display brightness of the partition is determined according to the image information of the pixel point on the image in the partition.

In specific implementation, the display device first determines the first image display brightness of the partition according to the image information of all pixel points on the image in the control partition, so as to determine whether the image displayed by the partition is a low-gray-scale image according to the first image display brightness, and further determine whether the PWM frequency of the driving signal needs to be increased to reduce the flicker feeling existing during low-gray-scale display.

For example, as shown in fig. 4, an image in a control partition O has four pixels, which represent the pixels of the image by RGB (red, green, blue, red, green, and blue) models:

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

the correspondence between the RGB model represented by the image and the YUV (Luminance, Chroma) model is known as follows:

luminance of a pixel: y ═ 0.229R +0.587G + 0.114B;

brightness of pixel point A: y is_A＝0.229×51+0.587×22+0.114×30＝28.013；

Brightness of the B pixel: y is_B＝0.229×25+0.587×33+0.114×5＝25.666；

And C, brightness of the pixel point: y is_C＝0.229×54+0.587×45+0.114×100＝50.181；

Brightness of the pixel point D: y is_D＝0.229×20+0.587×15+0.114×60＝20.225；

Controlling the image display luminance of the division O:

after the first image display brightness for controlling the subarea is determined, the determined first image display brightness is compared with a set brightness threshold value to determine whether the driving signal of the backlight of the subarea needs to be adjusted.

Optionally, if the first image display brightness is not greater than a preset first brightness threshold, the display device determines that the driving signal of the backlight source 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 a preset first brightness threshold, determines that the low-gray-scale image displayed in the partition has a flicker phenomenon, and needs to adjust the driving signal of the backlight source controlling the partition to reduce the flicker phenomenon when the low-gray-scale image is displayed.

For example: as shown in fig. 4, an image in a control partition O has four pixels, and the pixels of the image 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 luminance Y of the control division O_O31.02125; if the first brightness threshold is preset to be 50, it can be determined through comparison that the first image display brightness of the control partition O is smaller than the set first brightness threshold, so that the control partition O can be considered as a low-gray-scale image, and a flicker phenomenon exists during display, and it is necessary to adjust a driving signal of a backlight of the control partition O to reduce flicker during image display.

When determining that the driving signal of the backlight source for controlling the subareas needs to be adjusted, the display device also needs to determine the modulation parameter of the driving signal.

Optionally, the display device determines the magnification of the increase of the PWM frequency corresponding to the first image display brightness according to the correspondence between the first image display brightness and the magnification of the increase of the PWM frequency; then increasing the PWM frequency of the driving signal according to the determined multiplying power of the PWM frequency; wherein, the multiplying factor of the PWM frequency increase is more than or equal to 1.

In a specific implementation, when the control mode of the backlight of the display device is the partition control, after the display device determines the first image display brightness of each partition, the display device determines the multiplying factor of the PWM frequency increase of the driving signal corresponding to the partition according to the determined first image display brightness of each control partition and the corresponding relationship between the first image display brightness and the multiplying factor of the PWM frequency increase, and increases the PWM frequency of the driving signal according to the determined multiplying factor of the PWM frequency increase. Therefore, the display device can reduce the duration of the low level between two times of high levels of the driving signal by increasing the PWM frequency of the driving signal, so that the time of dark screen between two times of lightening of the backlight source is shortened, and the flicker feeling existing in the low gray scale display process is reduced accordingly.

For example: as shown in fig. 4, an image in a control partition O has four pixels, and the pixels of the image 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 luminance Y of the control division O_O31.02125; presetting a first brightness threshold value as 50; the PWM frequency of a driving signal of the backlight source of the current control subarea is 120 Hz; the correspondence between the given first image display brightness and the magnification of the PWM frequency increase is: and if the driving signals of the backlight sources of the control subareas need to be adjusted, uniformly adjusting the PWM frequency of the driving signals of the backlight sources of the control subareas to be 3 times of the original PWM frequency.

When determining to adjust the driving signal of the backlight source controlling the partition O, the display device adjusts the PWM frequency of the driving signal of the backlight source controlling the partition O to 360 Hz.

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

Further, in addition to determining the increased PWM frequency of the drive signal of the backlight that controls the partition O, it is necessary to determine the PWM duty of the drive signal of the backlight that controls the partition O.

With the above example, it is known that the determined image display luminance Y of the control section O_OWhen the duty ratio is 31.02125, the duty ratio of PWM of the drive signal in the control region is 31 ÷ 255 × 100% ═ 12%.

That is, the PWM duty of the drive signal of the backlight controlling the section O is 12%.

After the display device determines the PWM frequency corresponding to the first image display brightness and the PWM duty ratio of the corresponding driving signal, the display device generates the driving signal according to the determined PWM frequency of the driving signal of the control partition and the PWM duty ratio modulation of the driving signal.

Optionally, the display device modulates the driving signal according to the determined PWM frequency and the PWM duty determined by the image information.

In specific implementation, after determining the PWM frequency corresponding to the first image display brightness of the control partition and the PWM duty ratio of the corresponding driving signal, the display device calculates current data according to the determined PWM frequency and the determined PWM duty ratio and sends the current data to the PWM driving device; and then, the PWM driver adjusts the current according to the current data and the preset reference voltage Vref to finally obtain a driving signal generated by modulation, and drives the backlight source to emit light, so that the display device displays an image. Therefore, under the drive of the drive signal, the brightness of the backlight source is unchanged, and because the low level duration between two times of high levels of the drive signal is reduced, the dark screen duration between two times of lightening of the backlight source is shortened, so that the flicker feeling existing when the display device displays a low gray scale image is weakened to a certain extent, and the low gray scale display effect of the display device is improved to a certain extent.

And secondly, controlling the backlight source in the whole area.

In a specific implementation, when the backlight of the display device is controlled in the whole area, the control area of the display device is the whole display area, and only one backlight driving signal is provided, at this time, the display device processes the whole image display area.

In specific implementation, optionally, when the display device determines that the driving signal of the backlight source controlled in the whole area needs to be adjusted according to the image information of the pixel points on the image in the whole control area, the PWM frequency of the driving signal is increased.

According to the method, when the control mode of the backlight source of the display device is whole-area control, the display device determines that the driving signal of the backlight source controlled by the whole area needs to be adjusted according to the image information of all pixel points on the image in the whole control area, and the PWM frequency of the driving signal is increased. Therefore, when the display device displays the low gray scale image, on the premise of maintaining the unchanged brightness, the PWM frequency of the driving signal can be increased and the PWM duty ratio of the driving signal can be maintained, so that the low level duration between two times of high levels of the driving signal is reduced, the time of dark screen between two times of lightening of the backlight source is shortened, and the flicker feeling existing during low gray scale display is reduced accordingly.

Further, when implementing the technical solution of the embodiment of the present invention, the display device first determines whether the driving signal of the backlight source needs to be adjusted according to the image information of the image in the entire control area.

Optionally, the display device determines the second image display brightness of the entire control region according to the image information of the pixel points on the image in the entire control region.

In specific implementation, the display device first determines the second image display brightness of the entire control region according to the image information of all pixel points on the image in the entire control region, so as to determine whether the image displayed by the display device is a low gray scale image according to the second image display brightness, and further determine whether the PWM frequency of the driving signal of the backlight source needs to be increased to reduce the flicker feeling existing during low gray scale display.

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

Q₁(51，22，30)、Q₂(25，33，5)、Q₃(54，45,100)、Q₄(20，15，60)、……Q_n(25，5，30)；

the correspondence between the RGB model and the YUV model of the image representation indicates:

luminance of a pixel: y ═ 0.229R +0.587G + 0.114B;

Q₁the brightness of the pixel point is as follows: y is_A＝0.229×51+0.587×22+0.114×30＝28.013；

Q₂(luminance of pixel point: Y)_B＝0.229×25+0.587×33+0.114×5＝25.666；

Q₃The brightness of the pixel point is as follows: y is_C＝0.229×54+0.587×45+0.114×100＝50.181；

Q₄The brightness of the pixel point is as follows: y is_D＝0.229×20+0.587×15+0.114×60＝20.225；

……

Q_nThe brightness of the pixel point is as follows: y is_n＝0.229×25+0.587×5+0.114×30＝12.08；

Image display luminance of the entire control region Q:

wherein the number of pixel points of the image within the control area of the display device is related to the image resolution and area of the display device.

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

In a specific implementation, after determining that the display luminance of the second image is not greater than the preset second luminance threshold, the display device determines that the image displayed by the current display device is a low gray scale image, and the display image is driven by the conventional backlight driving signal, which causes a flicker phenomenon, so that the driving signal of the backlight needs to be adjusted to reduce the flicker when the image is displayed.

For example: the display region of the display device is composed of a plurality of pixel points, and the calculated image display brightness Y_{Machine for finishing}28; if the preset second brightness threshold is 50, the comparison result shows that the display brightness of the second image in the entire control area of the backlight is smaller than the set second brightness threshold, so that the image displayed by the display is a low-gray-scale image, and a flicker phenomenon may occur during display, and the driving signal of the backlight needs to be adjusted to reduce the flicker during displaying the image.

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

Optionally, the display device determines, according to a correspondence between the second image display luminance and the magnification of the PWM frequency increase, the magnification of the PWM frequency increase corresponding to the second image display luminance of the entire control region; subsequently increasing the PWM frequency of the driving signal according to the determined multiplying power of the PWM frequency increase; wherein, the multiplying factor of the PWM frequency increase is more than or equal to 1.

In a specific implementation, when the control mode of the backlight of the display device is full-area control, after the display device determines the second image display brightness of the whole control area, the PWM frequency increasing magnification corresponding to the second image display brightness of the whole control area is increased according to the determined second image display brightness and the correspondence between the second image display brightness and the PWM frequency increasing magnification, and then the PWM frequency of the driving signal is increased according to the determined PWM frequency increasing magnification. Therefore, the display device can reduce the duration of the low level between two times of high levels of the driving signal by increasing the PWM frequency of the driving signal, so that the time of dark screen between two times of lightening of the backlight source is shortened, and the flicker feeling existing in the low gray scale display process is reduced accordingly.

For example: the display region of the display device has a plurality of pixel points, and the calculated image display brightness Y_{Machine for finishing}28; presetting a second brightness threshold value as 50, wherein the PWM frequency of a driving signal of the current backlight source is 120 Hz; the correspondence between the given second image display brightness and the magnification of the PWM frequency increase is: and if the required driving signal of the backlight source is determined to be adjusted, uniformly adjusting the PWM frequency of the driving signal of the backlight source to be 2 times of the original PWM frequency.

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

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

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

Further, in addition to determining the PWM frequency of the increased drive signal of the backlight, it is also necessary to determine the PWM duty of the drive signal of the backlight. The manner of determining the PWM duty of the driving signal of the backlight source is similar to the above embodiments, and therefore, the description is omitted.

After the display device determines the PWM frequency corresponding to the second image display brightness and the PWM duty ratio of the corresponding driving signal, the display device generates the driving signal of the backlight source according to the determined PWM frequency of the driving signal of the control partition and the PWM duty ratio modulation of the driving signal.

In specific implementation, after determining the PWM frequency corresponding to the first image display brightness and the PWM duty of the corresponding driving signal, the display device generates the corresponding driving signal according to the determined PWM frequency and PWM duty, and drives the backlight source to emit light, so that the display device displays an image. Therefore, under the drive of the drive signal, the brightness of the backlight source is unchanged, and because the low level duration between two times of high levels of the drive signal is reduced, the dark screen duration between two times of lightening of the backlight source is shortened, so that the flicker feeling existing when the display device displays a low gray scale image is weakened to a certain extent, and the low gray scale display effect of the display device is improved to a certain extent.

In addition, since the low gray scale response of the TFT of the display panel is not ideal, the embodiment of the invention also performs gray scale compensation processing on the gray scale value of the image while adjusting the driving signal of the backlight of the display device, so as to improve the low gray scale display characteristics.

Optionally, for any pixel point, the display device determines a gray scale value of the pixel point in the control region according to image information of an image in the control region; then, according to the corresponding relation between the gray scale value and the gray scale compensation value, determining the gray scale compensation value corresponding to the gray scale value of the pixel point in the control area; and finally, compensating the gray scale value of the pixel point in the control area according to the determined gray scale compensation value.

In specific implementation, the display device firstly determines a gray scale value of the control area according to image information of an image in the control area, then determines a gray scale compensation value corresponding to the gray scale value of the control area according to a preset corresponding relationship between the gray scale value and the gray scale compensation value, and compensates the gray scale value of the control area according to the determined gray scale compensation value. Therefore, when the low gray scale display effect is not ideal, the compensation can be carried out through the corresponding relation between the preset gray scale value and the gray scale compensation value, the gray scale value when the low gray scale image is displayed is increased to a certain extent, the displayed image details are clearer, and the display effect is better.

For example: as shown in fig. 5, if a pixel a in a certain control area of the display device is represented by (20,10,55) in RGB mode according to the preset corresponding relationship between the gray scale value and the gray scale compensation value, the gray scale value of the pixel is 0.229 × 20+0.587 × 10+0.114 × 55, which is 16.15;

according to the corresponding relation between the gray scale value and the gray scale compensation value, the gray scale value of the pixel point is smaller than a preset gray scale value threshold value and belongs to a low gray scale, and the gray scale compensation value can be determined to be 16 according to the relation between the gray scale and the gray scale compensation value;

after the compensation value is determined, the original gray scale determined by the pixel is compensated indirectly according to the determined gray scale step value, and the compensated gray scale value is 32.

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

As shown in fig. 6, when the backlight source is in the partition control mode, the embodiment of the present invention provides a detailed flowchart of a method for modulating the backlight source driving signal.

Step 600, aiming at a control partition, the display device determines the brightness of each pixel point in the control partition according to the image information of all the pixel points of the image in the control partition;

601, the display device determines the first image display brightness of the control partition according to the brightness of each pixel point in the determined control partition;

step 602, the display device determines whether the display brightness of the first image is not greater than a set first brightness threshold, if yes, then step 603 and step 607 are executed; otherwise, go to step 606;

step 603, the display device determines the multiplying factor of the increased PWM frequency corresponding to the first image display brightness according to the determined first image display brightness and the corresponding relationship between the first image display brightness and the multiplying factor of the increased frequency;

step 604, the display device increases the PWM frequency of the driving signal according to the determined multiplying power of the PWM frequency increase;

step 605, the display device determines the PWM duty ratio of the driving signal;

606, the display device generates a driving signal of the backlight source according to the increased PWM frequency and the determined PWM duty ratio modulation;

step 607, the display device drives the backlight source by using the driving signal generated by modulation;

step 608, for a pixel, the display device determines the gray scale value of each pixel in the control partition according to the image information of all pixels of the image in the control partition;

step 609, the display device determines a gray scale compensation value corresponding to the gray scale value according to the corresponding relationship between the gray scale value and the gray scale compensation value;

step 610, the display device compensates the gray scale value of the pixel point in the control partition according to the determined gray scale compensation value;

611, displaying an image on the pixel point by the display device according to the compensated gray scale value;

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

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

step 614, the display device drives the backlight source by using the driving signal generated by modulation;

and step 615, ending the process.

As shown in fig. 7, the embodiment of the present invention provides a detailed flowchart of a method for modulating a backlight driving signal when the backlight is controlled in a whole area.

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

step 701, the display device determines the second image display brightness of the control area according to the determined brightness of each pixel point;

step 702, the display device determines whether the display brightness of the second image is not greater than a set second brightness threshold, if yes, step 703 and step 707 are executed; otherwise, go to step 704;

step 703, the display device determines the magnification of the increase of the PWM frequency corresponding to the second image display brightness according to the determined second image display brightness and the corresponding relationship 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 multiplying power of the PWM frequency;

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

step 706, the display device generates a driving signal of the backlight source according to the increased PWM frequency and the determined PWM duty ratio modulation;

step 707, the display device drives the backlight source by using the driving signal generated by modulation;

step 708, for a pixel, the display device determines a gray scale value of each pixel in the control area according to the image information of all pixels of the image in the whole control area;

709, the display device determines a gray scale compensation value corresponding to the gray scale value according to a corresponding relationship between the gray scale value and the gray scale compensation value;

step 710, the display device compensates the gray scale value of the pixel point in the control area according to the determined gray scale compensation value;

step 711, the display device displays an image on the pixel point according to the compensated gray scale value;

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 modulation;

714, the display device drives the backlight source by using the driving signal generated by modulation;

step 715, the process ends.

Fig. 11 and 12 respectively show waveforms of PWM driving a backlight provided in the prior art and the embodiment of the present invention, in which a) a curve corresponds to a PWM waveform of a high gray-scale image, and b) a curve corresponds to a PWM waveform of a low gray-scale image, a duty ratio of the PWM determined according to image information of the high gray-scale image is 60%, and a duty ratio of the PWM determined according to image information of the low gray-scale image is 5%.

The frequencies of the driving signals PWM of the backlights of the two images in fig. 11 are the same, and both are 120 HZ;

the frequency of the PWM corresponding to the high gray scale image in fig. 12 is 120HZ, and the frequency of the PWM corresponding to the low gray scale image is 240HZ, which is twice the fixed frequency 120 HZ.

Based on the same inventive concept, the embodiment of the present invention further provides a device for modulating a backlight driving signal, and since the device is a display device in the method in the embodiment of the present invention, and the principle of the device for solving the problem is similar to that of the method, the implementation of the device may refer to the implementation of the method, and repeated details are omitted.

As shown in fig. 8, an embodiment of the present invention provides an apparatus for modulating a backlight driving signal, where the apparatus includes: a processing unit 800 and a memory unit 801, wherein the memory unit stores program code that, when executed by the processing unit 800, causes the processing unit 800 to perform the following:

when judging that the driving signal of the backlight source needs to be adjusted according to the image information, increasing the Pulse Width Modulation (PWM) frequency of the driving signal; modulating the driving signal 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: judging whether the driving signal of the backlight needs to be adjusted or not by the following method:

determining a PWM duty ratio according to the image information; and if the PWM duty ratio is not larger than a preset duty ratio threshold value, determining that the driving signal of the backlight source needs to be adjusted.

Optionally, the backlight source is controlled in a partitioning manner; the processing unit 800 is specifically configured to:

aiming at any partition, when determining that the driving signal of the backlight source controlled by the partition needs to be adjusted according to the image information of all pixel points on the image in the partition, increasing the PWM frequency of the driving signal;

or the backlight source is controlled in the whole area, and the processing unit 800 is specifically configured to:

Optionally, the processing unit 800 is specifically configured to: judging whether the driving signal of the backlight needs to be adjusted or not by the following method: the backlight source is controlled in a partition mode,

aiming at any one subarea, determining the first image display brightness of the subarea according to the image information of all pixel points on the image in the subarea; if the first image display brightness is not greater than a preset first brightness threshold value, determining that the driving signal of the backlight source controlled in the subarea needs to be adjusted;

or the backlight source is controlled in the whole area,

determining second image display brightness of the whole control area according to image information of pixel points on an image in the whole control area; and if the display brightness of the second image is not greater than a preset second brightness threshold value, determining that the driving signal of the backlight source controlled by the whole area needs to be adjusted.

Optionally, the processing unit 800 is specifically configured to:

determining the multiplying power of the PWM frequency increase corresponding to the first image display brightness or the second image display brightness of the partition according to the corresponding relation between the first image display brightness or the second image display brightness and the multiplying power of the PWM frequency increase; increasing the PWM frequency of the driving signal according to the determined multiplying power of the PWM frequency; wherein, the multiplying factor of the PWM frequency increase is more than or equal to 1.

Optionally, the processing unit 800 is further configured to:

aiming at any pixel point, determining the gray scale value of the pixel point in the control area according to the image information of the image in the control area; determining a gray scale compensation value corresponding to the gray scale value of the pixel point in the control area according to the corresponding relation between the gray scale value and the gray scale compensation value; and compensating the gray scale value of the pixel point in the control area according to the determined gray scale compensation value.

The embodiment of the application provides a backlight source driving signal modulation method and a display device. Fig. 9 shows a block diagram of a possible terminal device. Referring to fig. 9, the terminal apparatus 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 a Wireless Fidelity (WiFi) module 980. Those skilled in the art will appreciate that the structure of the terminal device shown in fig. 9 does not constitute a limitation of the terminal device, and the terminal device provided in the embodiments of the present application may include more or less components than those shown, or may combine some components, or may be arranged in different components.

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

the RF circuit 910 may be used for receiving and transmitting 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 may also communicate with networks and other devices via wireless communication. The wireless communication may use any communication standard or protocol, including but not limited to Global System for mobile communications (GSM), General Packet Radio Service (GPRS), Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), Long Term Evolution (LTE), email, Short Messaging Service (SMS), and the like.

The WiFi technology belongs to a short-distance wireless transmission technology, and the terminal device 900 may connect to an Access Point (AP) through a WiFi module 980, thereby implementing Access to a data network. The WiFi module 980 may be used for receiving and transmitting data during communication.

The terminal device 900 may be physically connected to other devices via the communication interface 970. Optionally, the communication interface 970 is connected to the communication interfaces of the other devices through a cable, so as to implement data transmission between the terminal device 900 and the other devices.

Since the terminal device 900 can implement a communication service in this embodiment of the application, 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 communication modules such as the RF circuit 910, the WiFi module 980, and the communication interface 970, it is understood that at least one of the above components or other communication modules (such as a bluetooth module) for implementing communication exist in the terminal device 900 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 further include the WiFi module 980; when the terminal device 900 is a computer, the terminal device 900 may include the communication interface 970, and may further include the WiFi module 980; 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 executes various functional applications and data processing of the terminal apparatus 900 by executing software programs and modules stored in the memory 940.

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

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

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

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

The touch panel 951, also referred to as a touch screen, can collect touch operations of a user (for example, operations of a user on or near the touch panel 951 using any suitable object or accessory such as a finger or a stylus pen) and drive a corresponding connection device according to a preset program. Alternatively, the touch panel 951 may include two parts, i.e., a touch detection device and a touch controller. The touch detection device detects the touch direction of a user, detects a signal brought by touch operation and transmits the signal to the touch controller; the touch controller receives touch information from the touch sensing device, converts it into touch point coordinates, and sends the touch point coordinates to the processor 930, and can receive and execute commands sent from the processor 930. In addition, the touch panel 951 may be implemented in various types, such as resistive, capacitive, infrared, and surface acoustic wave.

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

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

The display unit 960 may include a display panel 961. Alternatively, the Display panel 961 may be configured in the form of a Liquid Crystal Display (LCD), an 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 the touch panel 951, the touch panel 951 transmits the touch operation to the processor 930 to determine the type of the touch event, and then the processor 930 provides a corresponding visual output on the display panel 961 according to the type of the touch event.

Although in fig. 9, the touch panel 951 and the display panel 961 are used as two independent components to implement the input and output functions of the terminal device 900, in some embodiments, the touch panel 951 and the display panel 961 may be integrated to implement the input and output functions of the terminal device 900.

The processor 930 is a control center of the terminal device 900, connects each component using various interfaces and lines, and performs various functions of the terminal device 900 and processes data by running or executing software programs and/or modules stored in the memory 940 and calling data stored in the memory 940, thereby implementing 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, wherein the application processor mainly handles operating systems, user interfaces, application programs, and the like, and the modem processor mainly handles wireless communications. It will be appreciated that the modem processor described above may not be integrated into the processor 930.

The terminal device 900 further comprises a power supply 920, such as a battery, for powering the various components. Optionally, the power supply 920 may be logically connected to the processor 930 through a power management system, so as to implement functions of managing charging, discharging, power consumption, and the like through the power management system.

Although not shown, the terminal device 900 may further include at least one sensor, an audio circuit, and the like, which are not described in detail herein.

Wherein the memory 940 may store the same program code as the storage unit 801, which when executed by the processor 930, causes the processor 930 to implement all functions of the processing unit 800.

As shown in fig. 10, an embodiment of the present invention provides an apparatus for modulating a backlight driving signal, where the apparatus includes:

the determining unit 1000 is configured to increase a Pulse Width Modulation (PWM) frequency of a driving signal when it is determined that the driving signal of the backlight needs to be adjusted according to the image information;

a modulation unit 1001 for modulating the driving signal according to the determined PWM frequency and the PWM duty determined by the image information.

Optionally, the determining unit 1000 is specifically configured to: judging whether the driving signal of the backlight needs to be adjusted or not by the following method:

Optionally, the backlight source is controlled in a partitioned manner, and the determining unit 1000 is specifically configured to:

aiming at any partition, when determining that the driving signal of the backlight source controlled by the partition needs to be adjusted according to the image information of the pixel points on the image in the partition, increasing the PWM frequency of the driving signal;

or the backlight source is controlled in the whole area, and the determining unit 1000 is specifically configured to:

Optionally, the determining unit 1000 is specifically configured to: judging whether the driving signal of the backlight needs to be adjusted or not by the following method: the backlight source is controlled in a partition mode,

or the backlight source is controlled in the whole area,

Optionally, the determining unit 1000 is specifically configured to:

Optionally, the apparatus further comprises:

the compensation unit 1002 is configured to determine, for any one pixel point, a gray scale value of the pixel point in the control region according to image information of an image in the control region; determining a gray scale compensation value corresponding to the gray scale value of the pixel point in the control area according to the corresponding relation between the gray scale value and the gray scale compensation value; and compensating the gray scale value of the pixel point in the control area according to the determined gray scale compensation value.

The embodiment of the invention also provides a readable storage medium of the computing equipment aiming at the method for modulating the backlight driving signal, namely, the content is not lost after the power is cut off. The storage medium has stored therein a software program, comprising program code, which when read and executed by one or more processors causes the implementation of any of the above aspects of the present invention when modulated by a backlight driving signal, when the program code runs on a computing device.

The present application is described above with reference to block diagrams and/or flowchart illustrations of methods, apparatus (systems) and/or computer program products according to embodiments of the application. It will be understood that one block of the block diagrams and/or flowchart illustrations, and combinations of blocks in the block diagrams and/or flowchart illustrations, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, and/or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer and/or other programmable data processing apparatus, create means for implementing the functions/acts specified in the block diagrams and/or flowchart block or blocks.

Accordingly, the subject application may also be embodied in hardware and/or in software (including firmware, resident software, micro-code, etc.). Furthermore, the present application may take the form of a computer program product on a computer-usable or computer-readable storage medium having computer-usable or computer-readable program code embodied in the medium for use by or in connection 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, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. A method of backlight drive signal modulation, the method comprising:

when judging that the driving signal of the backlight source needs to be adjusted according to the image information, increasing the Pulse Width Modulation (PWM) frequency of the driving signal;

2. The method of claim 1, wherein the determining whether the driving signal of the backlight source needs to be adjusted is performed by:

determining image display brightness according to the image information;

3. The method of claim 1, wherein the determining whether the driving signal of the backlight source needs to be adjusted is performed by:

determining a PWM duty ratio according to the image information;

4. The method of claim 1, wherein increasing the PWM frequency of the driving signal when it is determined that the driving signal of the backlight needs to be adjusted according to the image information comprises: the backlight source is controlled in a partition mode,

or the backlight source is controlled in the whole area,

when judging that the driving signal of the backlight source needs to be adjusted according to the image information, increasing the PWM frequency of the driving signal comprises the following steps:

5. The method of claim 2, wherein determining whether an adjustment to a drive signal of the backlight is needed is performed by: the backlight source is controlled in a partition mode,

if the first image display brightness is not greater than a preset first brightness threshold value, determining that the driving signal of the backlight source controlled in the subarea needs to be adjusted;

or the backlight source is controlled in the whole area,

6. The method of claim 5, wherein the increasing the PWM frequency of the drive signal comprises:

determining the multiplying power of the PWM frequency increase corresponding to the first image display brightness or the second image display brightness according to the corresponding relation between the first image display brightness or the second image display brightness and the multiplying power of the PWM frequency increase;

7. The method of any of claims 1 to 6, further comprising:

aiming at any pixel point, determining the gray scale value of the pixel point in the control area according to the image information of the image in the control area;

8. An apparatus for modulating a backlight drive signal, the apparatus comprising:

the determining unit is used for increasing the PWM frequency of the driving signal when the driving signal of the backlight source needs to be adjusted according to the image information;

a modulation unit for modulating the driving signal according to the determined PWM frequency and the PWM duty determined by the image information.

9. The apparatus of claim 8, wherein the determination unit is specifically configured to: judging whether the driving signal of the backlight needs to be adjusted or not by the following method:

determining image display brightness according to the image information;

10. The apparatus according to claim 8, wherein the backlight source is zone controlled, and the determining unit is specifically configured to:

or the backlight source is controlled in the whole area, and the determining unit is specifically configured to:

11. The apparatus as claimed in claim 9, wherein said determining unit is specifically configured to: judging whether the driving signal of the backlight needs to be adjusted or not by the following method: the backlight source is controlled in a partition mode,

or the backlight source is controlled in the whole area,

12. The apparatus of claim 8, wherein the determination unit is specifically configured to:

determining the multiplying power of the PWM frequency increase corresponding to the first image display brightness or the second image display brightness according to the corresponding relation between the first image display brightness or the second image display brightness and the multiplying power of the PWM frequency increase; increasing the PWM frequency of the driving signal according to the determined multiplying power of the PWM frequency; wherein, the multiplying factor of the PWM frequency increase is more than or equal to 1.

13. The apparatus of any of claims 8 to 12, further comprising:

the compensation unit is used for determining the gray-scale value of the pixel point in the control area according to the image information of the image in the control area aiming at any pixel point; determining a gray scale compensation value corresponding to the gray scale value of the pixel point in the control area according to the corresponding relation between the gray scale value and the gray scale compensation value; and compensating the gray scale value of the pixel point in the control area according to the determined gray scale compensation value.

14. A display device employing the method of backlight drive signal modulation of any one of claims 1 to 7 or comprising the apparatus of backlight drive signal modulation of any one of claims 8 to 13.

15. A television set, characterized in that it employs a method of backlight drive signal modulation as claimed in any one of claims 1 to 7 or comprises an apparatus of backlight drive signal modulation as claimed in any one of claims 8 to 13.