WO2017101273A1

WO2017101273A1 - Lattice backlight source driving method, device and system

Info

Publication number: WO2017101273A1
Application number: PCT/CN2016/084824
Authority: WO
Inventors: 段平
Original assignee: 深圳Tcl数字技术有限公司
Priority date: 2015-12-18
Filing date: 2016-06-03
Publication date: 2017-06-22
Also published as: CN105374323A; CN105374323B

Abstract

A lattice backlight source driving method and device. The method comprises: on the basis of input television signals, calculating the pulse width modulation (PWM) data controlling each light emitting diode (LED) lamp in the lattice backlight source (S10); on the basis of the PWM data, creating a statistical histogram, and on the basis of the statistical histogram, calculating the current parameter controlling each LED lamp (S20); and according to the PWM data and the current parameters, independently controlling each LED lamp and driving the lattice backlight source (S30). The invention achieves on-demand current distribution to all the LED lamps of the lattice backlight source, thereby reducing power consumption while optimizing the whole display effect, and avoiding power loss and energy waste.

Description

Dot matrix backlight driving method, device and system

Technical field

The present invention relates to the field of dot matrix backlight driving technology, and in particular, to a dot matrix backlight driving method, device and system.

Background technique

With the development of users and the development of backlight technology, liquid crystal display has rapidly replaced the traditional cathode ray tube display technology in many fields, making LCD (Liquid Crystal Display) display screen become the leading product in the home appliance market.

Many of the current LCD flat panel TVs use LED (Light Emitting Diode) dot matrix light sources. The LED dot matrix backlight has the advantages of good color reproduction, power saving and long life, and gradually replaces the traditional side-by-side or double-light strip-type side-entry light source. For different size TV sets, through the deployment and design of a reasonable number of dot matrix light source LED lights, the whole machine screen of the TV set not only has high brightness but uniform light perception, and solves the traditional side-entry light source multiple times. Defects in light guiding, insufficient brightness, and uneven light perception.

For the brightness control of LED dot matrix light source, there are currently two main ways: one is to adjust the driving current of the LED lamp; the other is to adjust the switching time of the driving circuit of the LED lamp, that is, to control the conduction time of the LED lamp power supply circuit and The turn-off time, commonly referred to as PWM (Pulse-Width Modulation), is the ratio of the on-time of the LED lamp power supply circuit to the sum of the on-time and the off-time. Through the driving current and duty ratio of the LED lamp, the brightness and power consumption of each LED lamp can be controlled, thereby adjusting and controlling the brightness of the whole screen of the television and the power consumption of the whole machine.

Due to the power consumption of the LCD flat panel TV, most of the backlight is consumed, and other components are consumed less. Therefore, the power of the backlight is controlled to meet the environmental protection requirements of energy saving and emission reduction. The existing method for adjusting the power of the backlight is mainly realized by adjusting the duty ratio of each LED lamp, and uniformly adjusting the current value of all the LED lamps in the backlight, or uniformly adjusting the LEDs by region by region division. The current value of the lamp is realized.

For example, when the rated current is used, the optimal brightness and image quality of the backlight can be achieved. At this time, the power is large, and the output power of the power source is required to be high, which wastes energy.

In order to reduce the power of the backlight, when the power of the backlight is reduced by half, the current of all the LEDs in the backlight can be adjusted to half of the rated current. At this time, since the image quality effect is not bright enough, even if the duty ratio of the bright portion of the screen is 100% by adjusting the duty ratio of the LED lamp, it is limited by the same current value, the contrast is small, and the bright portion is dark and dark. Part of the picture difference is not strong, resulting in poor picture effect, and the current of the LED in the dark part is wasted.

Or, in the current part of the backlight, a method of driving a LED dot matrix light source is driven by a method of driving sixteen, that is, an integrated circuit (IC) is used to simultaneously control sixteen LED lights. Since the current values of the sixteen LED lamps controlled by the same driver IC are the same, only the local control of the backlight can be realized, and the image quality effect still cannot achieve the ideal viewing effect of the user.

Therefore, it can be seen that although the prior art can perform PWM regulation on each LED lamp in the dot matrix backlight, due to the unified control of the current, if the brightness of the screen is ensured, power consumption is high and energy is wasted; When the power is reduced, the quality of the TV picture is poor, which affects the user's viewing experience.

Summary of the invention

The main object of the present invention is to provide a dot matrix backlight driving method, device and system, which aim to solve the technical problem that the current dot matrix backlight causes high power consumption and waste of energy in order to ensure picture quality.

To achieve the above object, the present invention provides a dot matrix backlight driving method, and the dot matrix backlight driving method includes the following steps:

Obtaining a brightness value of each LED lamp according to the brightness signal in the input television signal, and calculating pulse width modulation PWM data of each LED light source in the control dot matrix backlight according to the brightness value of each LED lamp;

Generating a statistical histogram according to the PWM data, and calculating a current parameter for controlling each LED lamp according to the statistical histogram;

The LED lights are independently controlled according to the PWM data and the current parameters to drive the dot matrix backlight.

In addition, in order to achieve the above object, the present invention further provides a dot matrix backlight driving device, and the dot matrix backlight driving device includes:

The image processing module is configured to obtain a brightness value of each LED light according to the brightness signal in the input television signal, and calculate a pulse width modulation PWM of each LED light in the control dot matrix backlight according to the brightness value of each LED lamp. data;

a driving management module, configured to generate a statistical histogram according to the PWM data, and calculate a current parameter for controlling each LED light according to the statistical histogram calculation;

And a driving circuit module, configured to independently control the LED lights according to the PWM data and the current parameter to drive the dot matrix backlight.

In addition, in order to achieve the above object, the present invention further provides a dot matrix backlight driving system, which includes a television video image processing MEMC module, a light emitting diode LED lamp driving control management module, and an LED lamp driving circuit module. ,among them:

The television video image processing MEMC module is configured to acquire, according to a brightness signal in the input television signal, a brightness value of each LED light, and calculate, according to the brightness value of each LED light, each LED light of the control dot matrix backlight. Pulse width modulation PWM data; transmitting the PWM data to the LED lamp drive control management module;

The LED lamp driving control management module is configured to receive the PWM data sent by the TV video image processing MEMC module; generate a statistical histogram according to the PWM data, and calculate the control according to the statistical histogram Current parameters of each LED lamp; transmitting the PWM data and the current parameter to the LED lamp driving circuit module.

The LED lamp driving circuit module is configured to receive the PWM data and the current sent by the LED lamp driving control management module; independently control the LED lights according to the PWM data and the current parameter, and drive the driving The dot matrix backlight.

A method, device and system for driving a dot matrix backlight according to an embodiment of the present invention, according to an input television signal, calculating pulse width modulation PWM data of each LED light of a control dot matrix backlight; and then, according to PWM Data, make a statistical histogram, and calculate the current parameters of each LED light according to the statistical histogram calculation; then, independently control each LED light according to the PWM data and current parameters, and drive the dot matrix backlight. The invention realizes that the currents of all the LED lights in the dot matrix backlight are allocated as needed, and the overall display effect of the television picture is achieved while reducing the power consumption, thereby avoiding power loss and energy waste.

DRAWINGS

1 is a schematic flow chart of a first embodiment of a method for driving a dot matrix backlight according to the present invention;

2 is a schematic diagram of a circuit of a dot matrix backlight LED driving IC according to an embodiment of the invention;

3 is a schematic diagram of a statistical histogram and a current line according to an embodiment of the present invention;

4 is a schematic diagram of functional modules of a first embodiment of a dot matrix backlight driving device according to the present invention;

5 is a schematic block diagram of a first embodiment of a dot matrix backlight source driving system according to the present invention;

6 is a schematic block diagram of a second embodiment of a dot matrix backlight driving system of the present invention.

The implementation, functional features, and advantages of the present invention will be further described in conjunction with the embodiments.

detailed description

It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The main solution of the embodiment of the present invention is: calculating pulse width modulation PWM data of each LED light of the LED in the control dot matrix backlight according to the input television signal; and generating a statistical histogram according to the PWM data, and according to the PWM data The statistical histogram calculation obtains current parameters for controlling the LED lights; independently controls the LED lights according to the PWM data and the current parameters to drive the dot matrix backlight.

Due to the unified control of the current in the prior art, if the brightness of the screen is ensured, the power consumption is high and the energy is largely wasted; when the power is reduced, the quality of the television picture is poor, which affects the viewing experience of the user.

The invention provides a solution for separately performing PWM control and current control on each LED lamp in the dot back backlight, and distributing current according to the actual content of the television picture, and utilizing the LED light source and the power source with maximum efficiency. It realizes the reduction of the power consumption of the dot back backlight while ensuring the TV picture effect.

Referring to FIG. 1 , a first embodiment of a dot matrix backlight driving method of the present invention provides a dot matrix backlight driving method, and the dot matrix backlight driving method includes:

Step S10: Calculate pulse width modulation PWM data of each LED of the LED in the control dot matrix backlight according to the input television signal.

The embodiment of the invention is mainly applied to the driving of the dot matrix backlight, and the power required for the power supply is reduced. At the same time, the quality of the displayed picture is guaranteed.

The embodiment can be applied to an LED (Light Emitting Diode) LED (Light Emitting Diode) LED dot matrix backlight driving, and can also be used for dot matrix backlight driving of other displays. Flexible settings according to actual needs. The dot matrix backlight driving method proposed by the invention can ensure that the screen brightness of the television meets the requirement of high image quality, and is not significantly affected by the drastic reduction of the power supply. The invention not only meets the requirements of energy saving and environmental protection, but also ensures that the brightness of the screen of the television reaches the best quality, that is, the embodiment of the invention can greatly improve the picture quality under the same power output power configuration.

This embodiment is illustrated by an LED dot matrix backlight power supply of a television set.

Specifically, as an implementation manner, when the television is started, the television video processor front end, that is, the video processing image processing MEMC (Motion Estimate and Motion Compensation) module of the central processing unit CPU dynamically acquires the television. The TV signal of each frame of the TV screen input by the signal source. Then, the TV video image processing MEMC module divides the television picture in the frame buffer into picture blocks corresponding to the number of LED lights in the LED dot matrix light source according to the number of LED dot matrix light sources. Then, according to the luminance signal in the input television signal, the luminance value of each picture block is obtained. The brightness of each picture block is counted, and a luminance histogram is generated, and the average brightness of each picture block is calculated according to the brightness histogram, and the obtained average brightness is used as the brightness of the LED light corresponding to each picture block. value. Then, PWM (Pulse-Width Modulation) data for controlling each LED lamp is calculated based on the luminance values of the respective LED lamps. Then, the TV video image processing MEMC module outputs the obtained PWM data to the driving board of the LED dot matrix light source for controlling the brightness of the corresponding LED lamp. When the PWM data of all the LED lights is calculated, the data sending module is started immediately. As the upper computer, the data to be sent is encoded and packaged, and then the data is sent to the LED dot matrix through the SPI (Serial Peripheral Interface) bus. The drive board of the light source.

Thereby, the driving board of the LED dot matrix light source obtains PWM data for controlling each LED lamp.

The larger the value of the PWM data, the brighter the picture corresponding to the PWM data; the smaller the value of the PWM data, the darker the picture corresponding to the PWM data. In this embodiment, the obtained PWM data is a duty ratio. In this embodiment, the on-time of the LED lamp power supply circuit is defined, and the ratio of the on-time and the off-time is called the duty ratio, for example, 80%, 60%, and the like. The on-time of the power supply circuit of each LED lamp can be independently controlled according to the duty ratio of each LED lamp, and local backlight adjustment can be performed.

Step S20: Create a statistical histogram according to the PWM data, and calculate a current parameter for controlling each LED lamp according to the statistical histogram.

The driver board of the LED dot matrix light source is managed by the LED lamp drive control management module. The LED lamp drive control management module includes an SPI receive data buffer, an SPI bus data receiving unit, a PWM data conversion calculation processing unit, a central CPU processing unit, an SPI transmit data buffer, and an SPI bus data transmitting unit. The central CPU processing unit on the LED dot matrix light source driving board controls the SPI bus data receiving unit to receive the data sent from the upper computer, and after data analysis, obtains the PWM data of each LED lamp sorted by the order. The resulting PWM data is then stored in the SPI receive data buffer. After obtaining the PWM data of each LED lamp in the dot matrix backlight power supply, the LED lamp driving control management module generates a statistical histogram according to the obtained PWM data, and calculates a control dot matrix backlight source. The current parameter of each LED lamp.

Specifically, the central CPU processing unit of the LED lamp driving control management module inputs the PWM data to the PWM data conversion calculation processing unit, and the PWM data conversion calculation processing unit converts and calculates the driving current parameter of each LED lamp according to the obtained PWM data.

As an implementation manner, first, the PWM data conversion calculation processing unit calculates the average current value of the LED lamp in the dot matrix backlight according to the preset total power of the dot matrix backlight, and the rated power supply voltage and the PWM data, and the average current is obtained. The value is taken as the initial current value of each LED lamp. Then, the PWM data conversion calculation processing unit creates a statistical histogram based on the obtained PWM data. Obtain the maximum value and the minimum value in the PWM data, calculate the interval value of the PWM data; then, obtain the number of PWM data groups according to the preset group distance and the interval value of the PWM data, complete the grouping of the PWM data; or according to the pre- Set the number of groups and the interval value of the PWM data to obtain the group distance of the PWM data, and complete the grouping of the PWM data; then, the value of the PWM data, that is, the duty ratio as the abscissa, the number of occurrences of the PWM data, that is, the LED The number of lamps is plotted on the ordinate to obtain a statistical histogram. The statistical histogram includes a histogram of each PWM data set, and each histogram contains the number of occurrences of the PWM data and the corresponding PWM value in the current PWM data set. The statistical histogram includes a histogram of each PWM data set, and each histogram represents the numerical range and number of occurrences of the PWM data in the current PWM data set. Then, in the statistical histogram, a current straight line is made based on the average current value. Each PWM data corresponds to a current parameter in the current line. Then, according to the preset rule, the center balance point of the statistical histogram is selected in the current straight line. Then, with this central equilibrium point as the center, the current line is rotated counterclockwise in a single step, so that the LED lamp with a larger PWM value obtains a larger current value, and the LED lamp with a smaller PWM value obtains a smaller current value to enhance the picture. The contrast between the bright part and the dark part.

During the linear rotation of the current, the PWM data conversion calculation processing unit calculates the current parameters corresponding to the respective PWM data according to the current straight line after each single-step rotation, thereby obtaining current parameters of the respective LED lamps. Then, based on the obtained current parameters of the LED lamps, the power consumed when controlling all the LED lamps in the dot matrix backlight is calculated. When the consumed power satisfies the total power of the pre-configured dot matrix backlight, the rotation current straight line is stopped, and each current parameter corresponding to the current straight line at this time is used as a current parameter for controlling each LED light in the dot matrix backlight. It should be noted that when the rotation current is straight, the step size per rotation is a preset threshold, which can be flexibly set according to actual needs. For example, if it is necessary to speed up the linear rotation speed of the current, and the calculated power consumption can quickly reach the total power of the pre-configured dot matrix backlight, the threshold of the rotation step can be set larger; if the control current is not required to rotate linearly Speed, for precise control, the threshold of the rotation step can be set smaller.

Thus, the PWM data conversion calculation processing unit obtains current parameters for each LED lamp in the control dot matrix backlight. In the present embodiment, the obtained current parameter is the current value. Then, the PWM data conversion calculation processing unit stores the current parameters of each of the LED lamps in the SPI transmission data buffer. The central CPU processing unit controls the SPI bus data transmitting unit to transmit the stored PWM data and current parameters to the driving circuit module of each LED lamp.

In this embodiment, all the PWM data is sent to the PWM data conversion calculation processing unit by acquiring the PWM data of the display picture of each frame, and the PWM data conversion calculation processing unit is calculated according to the PWM data according to the dot matrix backlight driving method provided by the present invention. Corresponding to the effective control current data of each LED lamp. Then, the central CPU processing unit outputs the LED light of the PWM data conversion module. The current data is refreshed to the corresponding current control circuit of each LED lamp through the SPI bus to control the current value of each LED lamp. The central CPU processing unit refreshes the PWM data to the corresponding PWM switching circuit of each LED lamp through the SPI bus, and accurately writes the PWM data to the driving PWM register of each LED lamp according to the address mapping table of the LED lamp for adjusting The circuit switching time of each LED lamp is such that the PWM pulse width duty ratio and the on current of each LED lamp can be freely set.

Step S30, independently controlling the LED lights according to the PWM data and the current parameter to drive the dot matrix backlight.

The driving circuit module of the LED lamp receives the PWM data and current parameters of each LED lamp in the dot matrix backlight, independently controls each LED lamp, and drives the dot matrix backlight.

Specifically, as an implementation manner, each LED light in the dot matrix backlight is configured with an independent PWM switching circuit and a current control circuit. Referring to FIG. 2, an internal design of an integrated circuit (IC) can be adopted. Improved implementation, or implementation of external circuit design in the driver IC. The driving circuit module of the LED lamp performs PWM control on each LED lamp through the PWM switching circuit of each LED lamp according to the acquired PWM data of each LED lamp, and controls the pulse width duty ratio of each LED lamp. At the same time, the driving circuit module of the LED lamp performs current control on each LED lamp through the current control circuit of each LED lamp according to the obtained current parameters of each LED lamp. Thereby, the driving circuit module of the LED lamp realizes driving of the dot matrix backlight and displays the current television picture. In this embodiment, each frame of the television is acquired in real time, and dynamic data analysis and calculation are performed in real time, thereby ensuring continuity and high image quality of the television picture.

In this embodiment, by preparing a statistical histogram according to the acquired PWM data, the current parameters of the LED lights corresponding to the PWM data are adjusted, and the currents of all the LED lights in the dot matrix backlight are allocated as needed, and the power consumption is guaranteed. Under the conditions, the TV screen as a whole can achieve the best display effect, avoiding power loss and energy waste.

Further, a second embodiment of the dot matrix backlight driving method of the present invention provides a dot matrix backlight driving method. Based on the first embodiment of the dot matrix backlight driving method of the present invention, the PWM data corresponds to the dot matrix. Each PWM data of each LED light in the backlight, the step S20 includes:

Step S21: Calculate an average current of each LED lamp in the dot matrix backlight according to the PWM data and the pre-configured dot matrix backlight total power and rated voltage.

After acquiring the PWM data of each LED lamp in the dot matrix backlight power supply, the central CPU processing unit of the LED lamp driving control management module inputs the PWM data to the PWM data conversion calculation processing unit, and the PWM data conversion calculation processing unit according to the obtained PWM data. The conversion calculates the drive current parameters for each LED lamp.

As an implementation manner, the PWM data conversion calculation processing unit calculates the average current value of the LED lamp in the dot matrix backlight according to the pre-configured total dot matrix backlight power, the rated power supply voltage, and the PWM data, and uses the average current value as The initial current value of each LED lamp.

The specific calculation process is as follows:

First, the average value of the PWM data is calculated based on the PWM data.

There are a total of n LED lights in the current dot matrix backlight. The PWM values of each LED lamp are PWM1, PWM2, PWM3, ... PWMn. The average value of the PWM data is PWM _avg , according to the formula PWM _avg = (PWM1+PWM2+PWM3+ ...+PWMn)/n calculates the PWM _avg .

Then, based on the pre-configured dot matrix backlight total power, and the rated power supply voltage and the average value of the PWM data, the maximum allowable average current value of the current dot matrix backlight is calculated.

To take the total power is P, the rated supply voltage is V, the average value of PWM data is PWM _avg, value is the average current I _avg, according to the formula _{I avg = P / (V ×} PWM avg) calculated I _avg.

Thereby, the average current value of the LED lamp in the dot matrix backlight is obtained.

Step S22: Create a statistical histogram according to each PWM data corresponding to each LED lamp in the dot matrix backlight.

The PWM data conversion calculation processing unit creates a statistical histogram based on the obtained PWM data.

First, the maximum value PWMmax and the minimum value PWMmin in the PWM data are acquired, and the interval value of the PWM data is calculated. The interval value can be obtained according to the formula PWMmax-PWMmin.

Then, according to the preset group distance and the interval value of the PWM data, the number of PWM data is obtained, and the grouping of the PWM data is completed; or the group distance of the PWM data is obtained according to the preset number of groups and the interval value of the PWM data, and the pair is completed. Grouping of PWM data. Then, the statistical histogram is created by taking the value of the PWM data, that is, the duty ratio as the abscissa, and the number of occurrences of the PWM data, that is, the number of LED lamps as the ordinate. The statistical histogram includes a histogram of each PWM data set, and each histogram represents the numerical range and number of occurrences of the PWM data in the current PWM data set.

Step S23, according to the average current, a current straight line is formed in the statistical histogram, and each PWM data in the statistical histogram corresponds to a current parameter on the current straight line.

After the statistical histogram is obtained, in the statistical histogram, a current straight line is created based on the average current value. Each PWM data corresponds to a current parameter in the current line.

Specifically, as an embodiment, in the statistical histogram, the virtual coordinate axis is obtained by using the current value corresponding to the PWM value as the virtual ordinate according to the abscissa indicating the PWM value. Then, with the average current value as the ordinate value, the maximum value PWMmax and the minimum value PWMmin in the PWM data are the abscissa, respectively, and point A and point B are obtained, and the point A and the point B are connected to obtain a current straight line AB. At this time, the average current value is an initial current value corresponding to each PWM data, that is, an initial current value of each LED lamp.

As another implementation manner, the current straight line can also be set as a curve according to actual needs, for example, a 2.2 gamma curve to achieve better picture performance. The current straight line referred to in this embodiment can be flexibly set according to actual needs.

Step S24, stepping the current straight line counterclockwise, and calculating a current parameter for controlling each LED lamp according to the linear line after the rotation.

After the current line is obtained, the current is linearly rotated, and the current parameter of each LED lamp in the control dot matrix backlight is calculated according to the linear line after the rotation.

Specifically, as an implementation manner, first, a center balance point of a statistical histogram is acquired on a current straight line according to a preset rule. Then, with this central equilibrium point as the center, the current line is rotated counterclockwise in a single step, so that the LED lamp with a larger PWM value obtains a larger current value, and the LED lamp with a smaller PWM value obtains a smaller current value to enhance the picture. The contrast between the bright part and the dark part. It should be noted that the rotation step of each rotation of the current straight line is a preset threshold. During the linear rotation of the current, the PWM data conversion calculation processing unit calculates the current parameters corresponding to the respective PWM data according to the current straight line after each single-step rotation, thereby obtaining current parameters of the respective LED lamps. Then, according to the obtained current parameters of each LED lamp, calculate all the LEDs in the backlight of the driving matrix The power consumed by the lamp. When the consumed power satisfies the total power of the pre-configured dot matrix backlight, the rotation current straight line is stopped, and each current parameter corresponding to the current straight line at this time is used as the current parameter of the corresponding PWM data, that is, in the control dot matrix backlight. Current parameters of each LED light.

Thus, the PWM data conversion calculation processing unit obtains current parameters for each LED lamp in the control dot matrix backlight. In the present embodiment, the obtained current parameter is the current value, and the dot matrix backlight driving device writes the current value of each LED lamp into its corresponding current control register.

Then, the PWM data conversion calculation processing unit stores the current parameters of each of the LED lamps in the SPI transmission data buffer. The central CPU processing unit controls the SPI bus data transmitting unit to transmit the stored PWM data and current parameters to the driving circuit module of each LED lamp.

In the embodiment, the initial current of each LED is determined by the average current of each LED lamp in the dot matrix backlight; then, the current parameter corresponding to each LED lamp is functionalized by a straight line to facilitate regulation; when the current is counterclockwise, the PWM is made. Larger LED lamps obtain larger current values and are brighter. LED lamps with smaller PWM values obtain smaller current values and lower brightness; linearly adjust the current parameters of the corresponding LED lamps by rotating current, thereby The power consumed by each LED is made to satisfy the preset total power. Therefore, the present embodiment satisfies the preset total power, ensures the quality of the television picture, realizes the goal of energy saving and emission reduction, is green and environmentally friendly, and at the same time ensures the picture effect and improves the user experience.

Further, the third embodiment of the dot matrix backlight driving method of the present invention provides a dot matrix backlight driving method. Based on the second embodiment of the dot matrix backlight driving method of the present invention, the step S24 includes:

Step S241: Select a center balance point of the statistical histogram on the current straight line according to a preset rule.

First, the central equilibrium point of the statistical histogram is obtained on the current line according to a preset rule. Specifically, as an implementation manner, the number of PWM data in each PWM data group in the statistical histogram is calculated as a percentage of the total amount of PWM data of all the LED lamps. The number of occurrences of the PWM data in each PWM data group is the number of PWM data in the data group. After obtaining the highest proportion of PWM data sets, one PWM data in this data set is selected according to a preset rule. The selection rule of the PWM data may be the intermediate value of the PWM data in the data group to which it belongs, or the maximum value of the PWM data, or other values of the data group to which it belongs. Then, the current value of the selected PWM data is set to the average current to obtain a point C corresponding to the current line. The abscissa of point C is the selected PWM value and the ordinate is the average current. Point C is the central equilibrium point obtained. Thereafter, the coordinate value of point C remains unchanged.

As another embodiment, a 2 equal point of the line segment between the point A and the point B on the current line may be selected as the center balance point. It is also possible to select any point on the line segment AB as the center balance point according to the PWM data. The obtained PWM value of the center balance point is the abscissa and the average current is the ordinate. Thereafter, the coordinate values of the center balance point remain unchanged.

Step S242: rotating the current straight line counterclockwise by using the center balance point as a rotation center point, and the rotation step length is a preset threshold.

After getting the center balance point, use this center balance point as the center of rotation and rotate counterclockwise in one step. The current is straight. It should be noted that the rotation step of each rotation of the current straight line is a preset threshold, and the rotation step length can be flexibly set according to the requirement of the processing speed. For example, if the processing speed needs to be increased, the threshold of the rotation step can be set larger; if the processing precision needs to be improved, the threshold of the rotation step can be set smaller. Since the initial state of the current line is parallel to the abscissa axis, counterclockwise rotation causes a larger PWM value to correspond to a larger current value, and a smaller PWM value corresponds to a smaller current value. Thereby, it is possible to obtain a larger current value for the LED lamp having a larger PWM value, and a smaller current value for the LED lamp having a smaller PWM value to enhance the contrast between the bright portion and the dark portion of the picture.

Step S243: Calculate a maximum current parameter of each LED lamp according to a preset rated current, and control a current parameter corresponding to each PWM data not to exceed the maximum current parameter and not less than a preset minimum current parameter.

When the current is linearly rotated, the LED lamp is too bright or too dark to ensure that the LED lamp is too bright or too dark according to the current corresponding to each PWM value obtained. Therefore, the maximum current parameter and the minimum current parameter are set to ensure that the current is linearly rotated. The current parameter makes the brightness of the LED light within a reasonable range. Specifically, as an implementation manner, first, a maximum current parameter of each LED lamp is calculated according to a preset rated current. Take the rated current as I rated, the maximum value of PWM data is PWMmax, and the maximum current of LED light is Imax, according to the formula:

Imax=I rated × PWMmax, calculate the maximum current value of each LED lamp, that is, the maximum current parameter.

Therefore, the maximum value of the current parameter corresponding to the PWM data corresponding to each LED lamp is Imax. In order to ensure that the brightness of each LED lamp is not too dark, the minimum current parameter Imin of each LED lamp is pre-set, thereby obtaining the PWM data corresponding to each LED lamp, and the minimum current parameter corresponding to the current line is Imin. Thereby, the maximum current parameter and the minimum current parameter corresponding to each PWM data are obtained. When the current is linearly rotated, the current parameter corresponding to the maximum PWM value is less than or equal to the maximum current parameter, so that the current parameter corresponding to each PWM data does not exceed the maximum current parameter; the current parameter corresponding to the minimum PWM value is greater than or equal to the minimum current. The parameter can realize that the current parameter corresponding to each PWM data is not lower than the minimum current parameter.

Step S244, calculating a current parameter for controlling each of the LED lamps according to the linear line after the rotation.

After each step of the current straight line is performed, the PWM data conversion calculation processing unit calculates the current parameters corresponding to the respective PWM data according to the current straight line after each single-step rotation, thereby obtaining the current parameters of the respective LED lamps. Then, based on the obtained current parameters of the LED lamps, the power consumed when driving all of the LED lamps in the dot matrix backlight is calculated. When the consumed power satisfies the total power of the pre-configured dot matrix backlight, the rotation current straight line is stopped, and each current parameter corresponding to the current straight line at this time is used as the current parameter of the corresponding PWM data, that is, in the control dot matrix backlight. Current parameters of each LED light. Thus, the PWM data conversion calculation processing unit obtains current parameters for each LED lamp in the control dot matrix backlight. Then, the dot matrix backlight driving device writes the current value of each LED lamp into its corresponding current control register. Then, the PWM data conversion calculation processing unit stores the current parameters of each of the LED lamps in the SPI transmission data buffer. The central CPU processing unit controls the SPI bus data transmitting unit to transmit the stored PWM data and current parameters to the driving circuit module of each LED lamp.

In this embodiment, by selecting the center balance point, the center balance point is rotated as a rotation axis, and the counterclockwise step is single step. The linearity of the rotating current makes the bright part of the picture brighter, the dark part is gray, enhances the contrast, and ensures that the brightness of the LED light is within a reasonable range. Driving each LED lamp according to the obtained current parameter not only satisfies the pre-configured total power, but also improves the picture quality.

Further, the fourth embodiment of the dot matrix backlight driving method of the present invention provides a dot matrix backlight driving method. Based on the third embodiment of the dot matrix backlight driving method of the present invention, the step S244 includes:

In step S2441, the current parameter corresponding to each PWM data is calculated according to the linear line after the rotation.

After each step of the current straight line is performed, the PWM data conversion calculation processing unit calculates the current parameters corresponding to the respective PWM data according to the current straight line after each single-step rotation, thereby obtaining the current parameters of the respective LED lamps.

Specifically, as an embodiment, referring to FIG. 3, a straight line z representing a mean current value is represented by a straight line z in a statistical histogram. After a straight line z is rotated counterclockwise by one step, a straight line AB is obtained, and the current value corresponding to the maximum value of the PWM data on the line AB does not exceed the maximum current value, and the current value corresponding to the minimum value of the PWM data on the line AB is not lower than the minimum current value.

The function of taking the straight line AB is y=kx+b, x is the PWM value, and y is the current parameter corresponding to x.

Since the center balance point is point C, the abscissa is the selected PWM value, and the ordinate is the average current, the point C coordinate value on the line AB is known. Since the rotation angle of the straight line z to the straight line AB is a preset value, the value of k can be calculated. Further, by calculating the coordinate value of the point C into the function of the straight line AB, the value of b can be obtained. Then, since the k value and the b value in the function y=kx+b are known, the PWM values are substituted into the function as the value of x, and the corresponding y value, that is, the current parameter, can be obtained. Thereby, the current parameters corresponding to the respective PWM data in the statistical histogram, that is, the current parameters of the respective LED lamps, are obtained.

Step S2442, calculating that the driving power of each of the LED lamps is controlled according to the PWM data and the corresponding current parameter.

After obtaining the current parameters corresponding to the PWM data in the statistical histogram, the power consumed when driving all the LED lights in the dot matrix backlight is calculated according to the obtained current parameters of the LED lamps.

Specifically, as an implementation manner, a total of n LED lights are used in the current dot matrix backlight, and the PWM values of the LED lights are PWM1, PWM2, PWM3, ... PWMn, and the current parameters are I1, I2, I3, ... In, When the rated voltage is V, the driving power P1 when driving the dot matrix backlight is calculated according to the following formula:

P1 = I1 × V × PWM1 + I2 × V × PWM2 + I3 × V × PWM3 + ... In × V × PWMn.

Thereby, the driving power at the time of controlling each LED lamp in the dot matrix backlight according to each PWM data and the corresponding current parameter is obtained.

Step S2443, determining whether the driving power reaches the total power.

After the driving power of each LED lamp in the backlight of the dot matrix is obtained, it is determined whether the current driving power reaches the pre-configured total power. Specifically, as an implementation manner, the total power configured in advance may be set according to actual requirements. According to the value of the total power, the preset power interval is taken, and the power value in the power interval is the power value reaching the total power. For example, if the power interval is 90% to 100% of the total power, the power value in this range reaches the total power, and the power value greater than 100% of the total power or less than 90% of the total power does not reach the total power. Determine whether the driving power is based on the obtained driving power value Total power is reached. If the driving power value is within the preset power interval, it is determined that the driving power reaches the total power; if the driving power is outside the preset power interval, it is determined that the driving power does not reach the total power. Thereby, the determination result is obtained.

Step S2444, if the driving power does not reach the total power, returning to the step of: rotating the current straight line counterclockwise with the center balance point as a rotation center point; if the driving power reaches the total For power, the current parameter corresponding to each PWM data is used as a current parameter for controlling each LED lamp and the current parameter is stored.

After the determination result is obtained, if the driving power does not reach the total power, the control current continues to rotate with the center balance point as the center of rotation, and rotates counterclockwise in a single step. After the rotation, it is determined whether the obtained driving TV satisfies the total power. If the driving power reaches the total power, the rotation current straight line is stopped, and each current parameter corresponding to the current straight line at this time is used as the current parameter of the corresponding PWM data, that is, the current parameter of each LED lamp in the dot matrix backlight is controlled. Thus, the PWM data conversion calculation processing unit obtains current parameters for each LED lamp in the control dot matrix backlight. Then, the dot matrix backlight driving device writes the current value of each LED lamp into its corresponding current control register. Then, the PWM data conversion calculation processing unit stores the current parameters of each of the LED lamps in the SPI transmission data buffer. The central CPU processing unit controls the SPI bus data transmitting unit to transmit the stored PWM data and current parameters to the driving circuit module of each LED lamp.

In this embodiment, after the driving power of each LED lamp is calculated, it is determined whether the total power is satisfied. If the power is not satisfied, the current parameters of each LED lamp are continuously adjusted until the driving power configured according to the obtained current parameter satisfies the configured total power. The current parameter is the optimal current configuration, which realizes the optimal configuration of the power consumption of each LED lamp, avoids waste of energy, and ensures the high image quality of the TV picture.

Referring to FIG. 4, a first embodiment of a dot matrix backlight driving device of the present invention provides a dot matrix backlight driving device, and the dot matrix backlight driving device includes:

The image processing module 100 is configured to calculate, according to the input television signal, pulse width modulation PWM data of each LED light of the LED in the control dot matrix backlight.

The driving management module 200 is configured to generate a statistical histogram according to the PWM data, and calculate a current parameter for controlling each LED lamp according to the statistical histogram.

The driving circuit module 300 is configured to independently control the LED lights according to the PWM data and the current parameter to drive the dot matrix backlight.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Please refer to the first embodiment of the dot matrix backlight driving method of the present invention.

Further, a second embodiment of the dot matrix backlight driving device of the present invention provides a dot matrix backlight driving device. According to the first embodiment of the dot matrix backlight driving device of the present invention, the PWM data corresponds to the dot matrix. Each PWM data of each LED light in the backlight, the drive management module 200 includes:

And a current averaging unit configured to calculate an average current of each of the LED lights in the dot matrix backlight according to the PWM data and the pre-configured dot matrix backlight total power and rated voltage.

a histogram making unit for each PWM corresponding to each LED light in the dot matrix backlight Data, making a statistical histogram.

And a current straight line unit configured to create a current straight line in the statistical histogram according to the average current, wherein each PWM data in the statistical histogram corresponds to a current parameter on the current straight line.

The single-step rotation unit is configured to rotate the current straight line counterclockwise, and calculate a current parameter for controlling each of the LED lamps according to the linear line after the rotation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Please refer to the second embodiment of the dot matrix backlight driving method of the present invention.

In this embodiment, the initial current of each LED is determined by the average current of each LED lamp in the dot matrix backlight; then, the current parameter corresponding to each LED lamp is functionalized by a straight line to facilitate regulation; when the current is reversed by a counterclockwise rotation, LED lamps with larger PWM values obtain larger current values and are brighter. LED lamps with smaller PWM values obtain smaller current values and lower brightness; linearly adjust the current parameters of the corresponding LED lamps by rotating current. Thereby, the power consumed by each LED satisfies the total power set in advance. Therefore, the present embodiment satisfies the preset total power, ensures the quality of the television picture, realizes the goal of energy saving and emission reduction, is green and environmentally friendly, and at the same time ensures the picture effect and improves the user experience.

Further, the third embodiment of the dot matrix backlight driving device of the present invention provides a dot matrix backlight driving device. According to the second embodiment of the dot matrix backlight driving device of the present invention, the single-step rotating unit includes:

The central point subunit is configured to select a center balance point of the statistical histogram on the current straight line according to a preset rule.

The rotating subunit is configured to rotate the current straight line counterclockwise by using the center balance point as a rotation center point, and the rotation step length is a preset threshold.

a boundary subunit, configured to calculate a maximum current parameter of each LED lamp according to a preset rated current, and control a current parameter corresponding to each PWM data not to exceed the maximum current parameter and not less than a preset minimum Current parameters.

The calculating subunit is configured to calculate a current parameter for controlling each of the LED lamps according to the linear line of the current after the rotation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Please refer to the third embodiment of the dot matrix backlight driving method of the present invention.

In this embodiment, by selecting the center balance point, the center balance point is rotated as the rotation axis, and the current straight line is rotated counterclockwise, so that the bright part of the picture is brighter, the gray part is dark, the contrast is enhanced, and the brightness of the LED lamp is ensured at a reasonable level. Within the scope. Driving each LED lamp according to the obtained current parameter not only satisfies the pre-configured total power, but also improves the picture quality.

Further, the fourth embodiment of the dot matrix backlight driving device of the present invention provides a dot matrix backlight driving device. According to the third embodiment of the dot matrix backlight driving device of the present invention, the calculating subunit includes:

The first calculating subunit is configured to calculate a current parameter corresponding to each of the PWM data according to the linear line after the rotation.

The second power subunit is configured to calculate, according to the rated voltage, the PWM data and the corresponding current parameter, driving power of each LED lamp according to the PWM data and a corresponding current parameter.

The third determining subunit is configured to determine whether the driving power reaches the total power.

a fourth obtaining subunit, configured to: if the driving power reaches the total power, The current parameter corresponding to the PWM data is used as a current parameter for controlling the LED lamps and stores the current parameter.

The rotating subunit is further configured to rotate the current straight line counterclockwise by using the center balance point as a rotation center point if the driving power does not satisfy the total power.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Please refer to the fourth embodiment of the dot matrix backlight driving method of the present invention.

Referring to FIG. 5, a first embodiment of a dot matrix backlight driving system of the present invention provides a dot matrix backlight driving system, and the dot matrix backlight source driving system includes a television video image processing MEMC module A, and an LED light source driving control management. Module B and LED lamp drive circuit module C, where:

The television video image processing MEMC module A is configured to calculate, according to the input television signal, pulse width modulation PWM data of each LED LED lamp in the control dot matrix backlight; and send the PWM data to the LED lamp Drive Control Management Module B.

The LED lamp driving control management module B is configured to receive the PWM data sent by the television video image processing MEMC module A; generate a statistical histogram according to the PWM data, and calculate and control according to the statistical histogram Current parameters of the LED lamps; transmitting the PWM data and the current parameters to the LED lamp driving circuit module C.

The LED lamp drive control management module B is located on the driving board of the LED dot matrix light source for receiving the PWM data sent by the TV video image processing MEMC module A, performing analysis and calculation, and obtaining the optimal current of each LED lamp in the dot matrix backlight source. The parameters are controlled and the PWM data and current parameters are sent to the LED lamp drive circuit module C.

When the LED lamp drive control management module B receives and parses the PWM data sent by the host computer, the data is used and processed in two parts. The first part is to directly write each PWM data to the drive PWM register of each LED lamp according to the corresponding address mapping table of the LED lamp to determine the switching time of each LED lamp; the other part is used to calculate the LED lights. The current parameter, that is, the current value, then writes the current value of each LED lamp into its corresponding current control register.

For example, for a dot matrix backlight configured with 288 LED lamps, by the embodiment of the dot matrix backlight driving method of the present invention, the current value of each LED lamp matching its PWM duty ratio is calculated, and then the 288 current values are obtained. Write to the corresponding 288 LED lamp current control registers, so that each LED lamp has a current control value, thus changing the prior art to make all LED lights or the same group of LED lights in the local area use the same The current value method not only improves the picture effect but also avoids power loss and energy waste.

Specifically, as an implementation manner, first, the LED lamp driving control management module B converts the PWM data into corresponding current parameters of the respective LED lamps. Then, the LED lamp driving control management module B refreshes the obtained LED lamp current parameters to the current driving circuit corresponding to each LED lamp through the SPI bus, and controls the current value of each LED lamp.

At the same time, the LED lamp drive control management module B directly refreshes the received PWM data to the PWM switch control circuit corresponding to each LED lamp through the SPI bus, and is used to adjust the circuit switching time of each LED lamp.

In this way, the PWM duty cycle and the on current of each LED lamp can be freely set.

The LED lamp driving control management module B converts the PWM data into a corresponding specific calculation process of the current parameters of each LED lamp, and configures a dot matrix backlight source of 288 LED lamps for illustration.

The TV is configured to work with all LED lights on the LED dot matrix backlight driver board. The power supply power is 420W, that is, the total power configured is 420W.

Since the supply voltage of the LED lamp plus the wire is 9V, that is, the rated voltage is 9V, the maximum current that can be used for all LED lamps to work normally is 420/9≈47A.

For the PWM data of all LED lamps is 100% duty cycle, the set current of each LED lamp can not exceed 47A/288*100%=163mA, otherwise the power of the entire dot matrix backlight driver board will exceed rationing. For a rich natural picture, not all PWM data is 100%, but various components. If you use a uniform current configuration, the bright area of the picture will not be bright enough. The dark place is not dark enough for the general situation. Especially in the dark picture area, the current of the lamp is also very high in configuration, causing unnecessary waste. Since the maximum rated current of each LED lamp can be up to 340 mA, and the bright place is not large enough because the current is limited, the brightness of the light source is not fully utilized.

In the case that the driving power does not exceed the total power, in order to enable each LED lamp to be assigned an optimum current value, the LED lamp driving control management module B establishes a statistical histogram, the abscissa, of the received PWM data of each LED lamp. For PWM data, ie duty cycle, the ordinate is the number of LED lights. For high duty-cycle LED lamps, a large current is distributed, so that these LED lamps emit the strongest light, for example, 100% is allocated to a maximum of 340 mA, and a low current value is assigned to a low duty ratio, so that these LED lamps are matched. The content of the screen is dimly lit, and so on. When the driving power does not exceed the total power of the configuration, the current values of all the LED lamps are calculated, thereby completing the current distribution of the actual content of the screen, thereby maximizing the efficiency. LED light source and power supply.

The LED lamp driving circuit module C is configured to receive the PWM data and the current sent by the LED lamp driving control management module B; and independently control the LED lights according to the PWM data and the current parameter, Driving the dot matrix backlight.

The driving circuit module C of the LED lamp receives the PWM data and current parameters of each LED lamp in the dot matrix backlight sent by the LED lamp driving control management module B, independently controls each LED lamp, and drives the dot matrix backlight source.

Specifically, as an implementation manner, each LED light in the dot matrix backlight is configured with an independent PWM switching circuit and a current control circuit. Referring to FIG. 2, an internal design of an integrated circuit (IC) can be adopted. Improved implementation, or implementation of external circuit design in the driver IC.

The driving circuit module C of the LED lamp performs PWM control on each LED lamp through the PWM switching circuit of each LED lamp according to the acquired PWM data of each LED lamp, and controls the pulse width duty ratio of each LED lamp. At the same time, the driving circuit module C of the LED lamp controls the current of each LED lamp through the current control circuit of each LED lamp according to the obtained current parameters of each LED lamp.

Thereby, the driving circuit module C of the LED lamp realizes driving of the dot matrix backlight and displays the current television picture. In this embodiment, each frame of the television is acquired in real time, and dynamic data analysis and calculation are performed in real time, thereby ensuring continuity and high image quality of the television picture.

The embodiment realizes independent control of each LED light in the dot matrix backlight, and cooperates with the television picture The actual content is distributed on demand, and the maximum efficiency utilizes the LED source and power supply.

Further, referring to FIG. 6, a second embodiment of the backlight driving system of the present invention provides a backlight driving system. According to the embodiment shown in FIG. 5, the LED lamp driving control management module B includes a serial peripheral interface. The SPI bus data receiving unit B1, the SPI receiving data buffer B2, the central CPU processing unit B3, the PWM data conversion calculation processing unit B4, the SPI transmission data buffer B5, and the SPI bus data transmitting unit B6, wherein:

The SPI bus data receiving unit B1 is configured to receive PWM data sent by the TV video image processing MEMC module A.

In this embodiment, the LED lamp drive control management module B is located on the driving board of the LED dot matrix light source, and passes through the SPI (Serial Peripheral Interface) bus and the TV video image processing MEMC module A and the LED lamp driving circuit. Module C interacts.

After the TV video image processing MEMC module A calculates the PWM data, and the PWM data is packaged and sent to the driving board of the LED dot matrix light source through the SPI bus, the SPI bus data receiving unit B1 receives the PWM data sent by the TV video image processing MEMC module A. package.

The central CPU processing unit B3 analyzes the obtained PWM data packet to obtain each PWM data in the PWM data packet.

The SPI receives a data buffer B2 for storing the PWM data.

After obtaining the PWM data sent by the TV video image processing MEMC module A, the SPI receiving data buffer B2 stores the obtained PWM data for subsequent data analysis processing.

The central CPU processing unit B3 is configured to control and coordinate the processing of the PWM data.

The central CPU processing unit B3 is used to control and coordinate the operations of the units in the LED lamp drive control management module B.

Specifically, the central CPU processing unit B3 controls the SPI bus data receiving unit B1 to receive the PWM data packet transmitted by the television video image processing MEMC module A.

Then, the central CPU processing unit B3 parses the PWM data packet to obtain each sorted PWM data, and stores each PWM data in the SPI receive data buffer B2.

Then, the central CPU processing unit B3 sends each PWM data to the PWM data conversion calculation processing unit B4, and the PWM data conversion calculation processing unit B4 processes and calculates the current parameters of each LED lamp, and stores the obtained LED lamp current parameters. The SPI sends a data buffer.

Thereby, PWM data and current parameters for controlling each LED lamp are obtained.

Then, the central CPU processing unit controls the SPI bus data transmitting unit B6 to transmit the stored PWM data and current parameters to the driving circuit module C of each LED lamp to control the respective LED lamps.

The PWM data conversion calculation processing unit B4 is configured to generate a statistical histogram according to the PWM data, and calculate a current parameter for controlling each LED lamp according to the statistical histogram.

After acquiring the PWM data corresponding to the LED lamp sent by the central CPU processing unit B3, the PWM data conversion calculation processing unit B4 creates a statistical histogram and calculates a corresponding current parameter for controlling each LED lamp.

Specifically, as an implementation manner, first, the PWM data conversion calculation processing unit B4 calculates an average current of each LED lamp in the dot matrix backlight according to each PWM data and a preset total dot matrix backlight power and rated voltage.

Then, according to the PWM data of each LED lamp in the corresponding dot matrix backlight, the statistics are straight. The square graph gives the distribution of the PWM data.

Then, the PWM data conversion calculation processing unit B4 creates a current straight line in the statistical histogram according to the average current of each LED lamp, and counts the current parameters on the current line corresponding to each PWM data in the histogram.

Then, according to the preset rule, the center equilibrium point of the statistical histogram is selected on the current line, and the coordinates of the center balance point are known and remain unchanged.

Then, with the selected center balance point as the rotation center point, the current straight line is rotated counterclockwise, and the rotation step is a preset threshold. The current is rotated linearly so that the larger PWM value corresponds to a larger current parameter, and the smaller PWM value corresponds to a smaller current parameter, so that the bright portion of the television picture is brighter, the gray portion is darker, and the contrast is enhanced.

During the rotation process, the boundary value of the current parameter corresponding to the PWM value is controlled so that the current parameter corresponding to each PWM data does not exceed the maximum current value, and is not lower than the minimum current value, thereby ensuring that the brightness of the picture is within a reasonable range.

Then, based on the current straight line obtained after the rotation, the current parameters for controlling the respective LED lamps are calculated. And according to the obtained current parameter, it is judged whether the power consumed when driving the dot matrix backlight according to the obtained current parameter satisfies the preset total power.

If the consumed power does not satisfy the preset total power, the current is continuously rotated; if the consumed power meets the preset total power, the current parameter obtained at this time is used as the current parameter of each LED lamp, and The current parameter is sent to the SPI Transmit Data Buffer B5.

The SPI transmits a data buffer B5 for storing the current parameter.

The SPI transmission data buffer B5 receives the current parameters corresponding to the LED lamps transmitted by the PWM data conversion calculation processing unit B4, and stores them.

The SPI bus data transmitting unit B6 is configured to send the PWM data and the current parameter to the LED lamp driving circuit module C.

The SPI bus data transmitting unit B6 transmits the stored PWM data and current parameters to the corresponding LED lamps, respectively.

Specifically, as an implementation manner, the SPI bus data transmitting unit B6 accurately writes each PWM data into the driving PWM register of each LED lamp according to the address mapping relationship table of each LED lamp to determine the switching time of each LED lamp.

The SPI bus data transmitting unit B6 writes the current value of each LED lamp into its corresponding current control register. For example, for a dot matrix backlight configured with 288 LED lamps, the dot matrix backlight driving method provided by the present invention calculates the current value of each LED lamp and its PWM data, that is, the duty ratio, and then starts the SPI bus data. Transmitting unit B6 writes the 288 current values into the current control registers of the corresponding 288 LED lamps so that each lamp has a current control value.

This embodiment changes the prior art to make all the LED lights or the same group of LED lights in the local area use the same current value, and realizes that the currents of all the LED lights in the dot matrix backlight are allocated as needed, and are guaranteed. Under the condition of power consumption, the TV screen as a whole can achieve the best display effect, avoiding power loss and energy waste.

The above are only the preferred embodiments of the present invention, and are not intended to limit the scope of the invention, and the equivalent structure or equivalent process transformations made by the description of the present invention and the drawings are directly or indirectly applied to other related technical fields. The same is included in the scope of patent protection of the present invention.

Claims

A dot matrix backlight driving method is characterized in that the dot matrix backlight driving method comprises the following steps:

Obtaining a brightness value of each LED lamp according to the brightness signal in the input television signal, and calculating pulse width modulation PWM data of each LED light source in the control dot matrix backlight according to the brightness value of each LED lamp;

Generating a statistical histogram according to the PWM data, and calculating a current parameter for controlling each LED lamp according to the statistical histogram;

The LED lights are independently controlled according to the PWM data and the current parameters to drive the dot matrix backlight.
The method of driving a dot matrix backlight according to claim 1, wherein the PWM data is corresponding to each PWM data of each LED lamp in the dot matrix backlight, and the statistics are generated according to the PWM data. The histogram, and calculating the current parameters of the LED lights according to the statistical histogram calculation, includes:

Calculating an average current of each LED lamp in the dot matrix backlight according to the PWM data and a pre-configured dot matrix backlight total power and a rated voltage;

Generating a statistical histogram according to each PWM data corresponding to each LED lamp in the dot matrix backlight;

Forming, according to the average current, a current straight line in the statistical histogram, wherein each PWM data in the statistical histogram corresponds to a current parameter on the current straight line;

The current straight line is rotated stepwise in a counterclockwise manner, and the current parameters for controlling the respective LED lamps are calculated according to the linear line of the current after the rotation.
The method of driving a dot matrix backlight according to claim 2, wherein the counterclockwise single-step rotation of the current straight line, and calculating the current parameter of each LED lamp according to the linear line after the rotation The steps include:

Selecting a center balance point of the statistical histogram on the current line according to a preset rule;

Taking the center balance point as a rotation center point, and rotating the current straight line counterclockwise, the rotation step length is a preset threshold value;

Calculating a maximum current parameter of each LED lamp according to a preset rated current, and controlling a current parameter corresponding to each PWM data not to exceed the maximum current parameter and not less than a preset minimum current parameter;

The current parameters for controlling the respective LED lamps are calculated based on the straight line of the current after the rotation.
The method of driving a dot matrix backlight according to claim 3, wherein the step of calculating a current parameter of each LED lamp in the backlight of the dot matrix according to the linear line of the current after the rotation comprises:

Calculating current parameters corresponding to the respective PWM data according to the linear line of the current after the rotation;

Calculating, according to the rated voltage, the PWM data and the corresponding current parameter, controlling driving power of each LED lamp according to each PWM data and a corresponding current parameter;

Determining whether the driving power reaches a pre-configured total power;

If the driving power does not reach the total power, returning to the execution step: rotating the current straight line counterclockwise with the center balance point as a rotation center point, and the rotation step length is a preset threshold value;

And if the driving power reaches the total power, the current parameter corresponding to each PWM data is used as a current parameter for controlling each LED lamp, and the current parameter is stored.
The method of driving a dot matrix backlight according to claim 2, wherein the step of creating a statistical histogram according to each PWM data corresponding to each of the LED lights in the dot matrix backlight comprises:

Obtaining a maximum value and a minimum value in the PWM data, and calculating an interval value of the PWM data;

And determining, according to the preset group distance and the interval value of the PWM data, the PWM data, or grouping the PWM data according to the preset number of groups and the interval value of the PWM data. , grouping PWM data;

A statistical histogram is created by taking the value of the PWM data as the abscissa and the number of occurrences of the PWM data as the ordinate.
The method of driving a dot matrix backlight according to claim 4, wherein the step of creating a statistical histogram according to each PWM data corresponding to each of the LED lights in the dot matrix backlight comprises:

Obtaining a maximum value and a minimum value in the PWM data, and calculating an interval value of the PWM data;

And determining, according to the preset group distance and the interval value of the PWM data, the PWM data, or grouping the PWM data according to the preset number of groups and the interval value of the PWM data. , grouping PWM data;

A statistical histogram is created by taking the value of the PWM data as the abscissa and the number of occurrences of the PWM data as the ordinate.
The method of driving a dot matrix backlight according to claim 4, wherein the step of determining whether the driving power reaches a pre-configured total power comprises:

And determining, according to the value of the total power, a preset power interval, where the power value in the power interval is a power value that reaches a total power;

If the driving power value is within the preset power interval, determining that the driving power reaches a total power; if the driving power is outside the preset power interval, determining that the driving power is not Total power is reached.
The method of driving a dot matrix backlight according to claim 6, wherein the step of determining whether the driving power reaches a pre-configured total power comprises:

And determining, according to the value of the total power, a preset power interval, where the power value in the power interval is a power value that reaches a total power;

If the driving power value is within the preset power interval, determining that the driving power reaches a total power; if the driving power is outside the preset power interval, determining that the driving power is not Total power is reached.
A dot matrix backlight driving device, wherein the dot matrix backlight driving device comprises:

The image processing module is configured to obtain a brightness value of each LED light according to the brightness signal in the input television signal, and calculate a pulse width modulation PWM of each LED light in the control dot matrix backlight according to the brightness value of each LED lamp. Data

a driving management module, configured to generate a statistical histogram according to the PWM data, and calculate a current parameter for controlling each LED light according to the statistical histogram calculation;

And a driving circuit module, configured to independently control the LED lights according to the PWM data and the current parameter to drive the dot matrix backlight.
The dot matrix backlight driving device of claim 9, wherein the PWM data is corresponding to each PWM data of each of the LED backlights, and the driving management module comprises:

a current averaging unit, configured to calculate an average current of each LED lamp in the dot matrix backlight according to the PWM data and a pre-configured dot matrix backlight total power and a rated voltage;

a histogram making unit, configured to generate a statistical histogram according to each PWM data corresponding to each LED light in the dot matrix backlight;

a current straight line unit, configured to create a current straight line in the statistical histogram according to the average current, wherein each PWM data in the statistical histogram corresponds to a current parameter on the current straight line;

The single-step rotation unit is configured to rotate the current straight line counterclockwise, and calculate a current parameter for controlling each of the LED lamps according to the linear line after the rotation.
The dot matrix backlight driving device of claim 10, wherein the single-step rotation unit comprises:

a central point subunit, configured to select a center balance point of the statistical histogram on the current straight line according to a preset rule;

a rotating subunit, configured to rotate the current straight line counterclockwise by using the center balance point as a rotation center point, and the rotation step length is a preset threshold value;

a boundary subunit, configured to calculate a maximum current parameter of each LED lamp according to a preset rated current, and control a current parameter corresponding to each PWM data not to exceed the maximum current parameter and not less than a preset minimum Current parameter

The calculating subunit is configured to calculate a current parameter for controlling each of the LED lamps according to the linear line of the current after the rotation.
The dot matrix backlight driving device of claim 11, wherein the calculating subunit comprises:

a first calculating subunit, configured to calculate, according to the rotated current line, a current parameter corresponding to each PWM data;

a second power subunit, configured to calculate, according to the rated voltage, the PWM data and the corresponding current parameter, driving power of each LED lamp according to the PWM data and a corresponding current parameter;

a third determining subunit, configured to determine whether the driving power reaches a pre-configured total power;

a fourth acquiring subunit, configured to: if the driving power reaches the total power, use a current parameter corresponding to each PWM data as a current parameter for controlling each LED lamp and store the current parameter;

The rotating subunit is further configured to rotate the current straight line counterclockwise by using the center balance point as a rotation center point if the driving power does not reach the total power.
The method of driving a dot matrix backlight according to claim 10, wherein the histogram making unit is further configured to:

Obtaining a maximum value and a minimum value in the PWM data, and calculating an interval value of the PWM data;

And determining, according to the preset group distance and the interval value of the PWM data, the PWM data, or grouping the PWM data according to the preset number of groups and the interval value of the PWM data. , grouping PWM data;

A statistical histogram is created by taking the value of the PWM data as the abscissa and the number of occurrences of the PWM data as the ordinate.
The dot matrix backlight driving method according to claim 12, wherein the histogram making unit is further configured to:

Obtaining a maximum value and a minimum value in the PWM data, and calculating an interval value of the PWM data;

And determining, according to the preset group distance and the interval value of the PWM data, the PWM data, or grouping the PWM data according to the preset number of groups and the interval value of the PWM data. , grouping PWM data;

A statistical histogram is created by taking the value of the PWM data as the abscissa and the number of occurrences of the PWM data as the ordinate.
The method of driving a dot matrix backlight according to claim 12, wherein the third determining subunit is further configured to:

And determining, according to the value of the total power, a preset power interval, where the power value in the power interval is a power value that reaches a total power;

If the driving power value is within the preset power interval, determining that the driving power reaches a total power; if the driving power is outside the preset power interval, determining that the driving power is not Total power is reached.
The method of driving a dot matrix backlight according to claim 14, wherein the third determining subunit is further configured to:

And determining, according to the value of the total power, a preset power interval, where the power value in the power interval is a power value that reaches a total power;

If the driving power value is within the preset power interval, determining that the driving power reaches a total power; if the driving power is outside the preset power interval, determining that the driving power is not Total power is reached.
A dot matrix backlight driving system is characterized in that: the dot matrix backlight driving system comprises a television video image processing MEMC module, a light emitting diode LED lamp driving control management module and an LED lamp driving circuit module, wherein:

The television video image processing MEMC module is configured to acquire, according to a brightness signal in the input television signal, a brightness value of each LED light, and calculate, according to the brightness value of each LED light, each LED light of the control dot matrix backlight. Pulse width modulation PWM data; transmitting the PWM data to the LED lamp drive control management module;

The LED lamp driving control management module is configured to receive the PWM data sent by the TV video image processing MEMC module; generate a statistical histogram according to the PWM data, and calculate the control according to the statistical histogram Current parameters of each LED lamp; transmitting the PWM data and the current parameter to the LED lamp driving circuit module.

The LED lamp driving circuit module is configured to receive the PWM data and the current sent by the LED lamp driving control management module; independently control the LED lights according to the PWM data and the current parameter, and drive the driving The dot matrix backlight.
The backlight driving system of claim 17, wherein the LED lamp driving control management module comprises a serial peripheral interface SPI bus data receiving unit, an SPI receiving data buffer, a central CPU processing unit, and a PWM data conversion. The calculation processing unit, the SPI transmission data buffer, and the SPI bus data transmission unit, wherein:

The SPI bus data receiving unit is configured to receive PWM data sent by the TV video image processing MEMC module;

The SPI receives a data buffer for storing the PWM data;

The central CPU processing unit is configured to control and coordinate processing of the PWM data;

The PWM data conversion calculation processing unit is configured to generate a statistical histogram according to the PWM data, and calculate a current parameter for controlling each LED lamp according to the statistical histogram;

The SPI sends a data buffer for storing the current parameter;

The SPI bus data sending unit is configured to send the PWM data and the current parameter to the LED lamp driving circuit module.