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CN105374323A - Dot matrix backlight source drive method, device and system - Google Patents

️Wed Mar 02 2016

Embodiment

Should be appreciated that specific embodiment described herein only in order to explain the present invention, be not intended to limit the present invention.

The primary solutions of the embodiment of the present invention is: according to the TV signal of input, calculates the pulse width modulation (PWM) data controlling each LED lamp in dot matrix backlight; According to described PWM data, make statistic histogram, and calculate the current parameters controlling described each LED according to described statistic histogram; Independently control described each LED according to described PWM data and described current parameters, drive described dot matrix backlight.

Due to prior art because the unified of electric current controls, if ensure picture brightness, then power consumption can be caused high, and the energy is wasted in a large number; And when reducing power, television picture quality is poor, affect the viewing experience of user.

The invention provides a solution, separately to some the back of the body backlight in each LED carry out PWM control and Current Control, coordinate television image actual content distribution according to need electric current, maximal efficiency make use of LED light source and power.Achieve while reducing some back of the body backlight consumed power, ensure television image effect.

With reference to Fig. 1, dot matrix backlight drive method first embodiment of the present invention provides a kind of dot matrix backlight drive method, and described dot matrix backlight drive method comprises:

Step S10, TV signal according to input, calculate the pulse width modulation (PWM) data controlling each LED lamp in dot matrix backlight.

The embodiment of the present invention is mainly used in the driving of dot matrix backlight, while reduction is to power configuration power demand, ensures the picture image quality of display.

The present embodiment can be applied to LCD (LiquidCrystalDisplay, liquid crystal display) LED (LightEmittingDiode of flat panel TV, light emitting diode) array light source dot matrix backlight driver, also may be used for the dot matrix backlight driver of other displays, can arrange flexibly according to actual needs.The dot matrix backlight drive method proposed by the present invention, can ensure that the picture brightness of televisor meets the demand of high image quality, can not be subject to obvious impact because of the significantly reduction of power simultaneously.Achieve the demand both meeting energy-conserving and environment-protective and reduce discharging, in turn ensure that the picture brightness of televisor reaches best in quality simultaneously, also, the embodiment of the present invention significantly can improve image quality under the configuration of identical output power of power supply.

The present embodiment drives with the LED dot matrix backlight electric power of televisor and is illustrated.

Concrete, as a kind of embodiment, after televisor starts, TV video processor front end, also the TV signal of every frame television image of i.e. television video image procossing MEMC (MotionEstimateandMotionCompensation, Motion estimation and compensation) the module Dynamic Acquisition TV signal source input of central processor CPU.

Then, the television image in frame buffer to be divided into, one to one picture block equal with the LED quantity in LED array light source according to the quantity of LED array light source by television video image procossing MEMC module.

Then, according to the luminance signal in the TV signal of input, the brightness value of each picture block is obtained.Add up the brightness of each picture block, and make brightness histogram, then calculate the mean flow rate of each picture block described according to this brightness histogram, and using the mean flow rate that the obtains brightness value as LED corresponding to each picture block.Then, PWM (Pulse-WidthModulation, the pulse-length modulation) data controlling each LED are calculated according to the brightness value of each LED.

Then, the PWM data obtained are outputted to the drive plate of LED array light source by television video image procossing MEMC module, for controlling the luminosity of corresponding LED.

When the PWM data of all LED calculate complete, start data transmission blocks immediately, as host computer, the data encoding packing that first will send, then by SPI (SerialPeripheralInterface, Serial Peripheral Interface (SPI)) bus, data are sent to the drive plate of LED array light source.

Thus, the drive plate of LED array light source obtains the PWM data controlling each LED.

The numerical value of PWM data is larger, also just represents that picture corresponding to these PWM data is brighter; The numerical value of PWM data is less, also just represents that picture corresponding to these PWM data is darker.

In the present embodiment, the PWM data obtained are dutycycle.Define the ON time of LED feed circuit in the present embodiment, account for the ratio of ON time and turn-off time sum, be called dutycycle, such as 80%, 60% etc.Can according to the dutycycle of each LED, the independent feed circuit ON time controlling each LED, carries out local backlight adjustment.

Step S20, according to described PWM data, make statistic histogram, and calculate the current parameters controlling described each LED according to described statistic histogram.

The drive plate of LED array light source is managed by LED drived control administration module.Wherein, LED drived control administration module comprises SPI reception data buffer, spi bus data receipt unit, PWM data conversion calculation processing unit, central cpu processing unit, SPI transmission data buffer and spi bus data transmission unit.

Central cpu processing unit on LED array light source drive plate controls after spi bus data receipt unit receives the data that host computer sends, to obtain the PWM data of each LED by cis-position sequence through Data Analysis.Then, the PWM data obtained are received data buffer stored in SPI.

After the PWM data obtaining each LED in dot matrix backlight electric power, LED drived control administration module, according to the PWM data obtained, makes statistic histogram, and calculates the current parameters controlling each LED in dot matrix backlight.

Concrete, PWM data are inputed to PWM data conversion calculation processing unit by the central cpu processing unit of LED drived control administration module, PWM data conversion calculation processing unit is according to the PWM data obtained, and conversion calculates the drive current parameter of each LED.

As a kind of embodiment, first, PWM data conversion calculation processing unit is according to pre-configured dot matrix backlight general power, and rated supply voltage, PWM data, calculate the average current value of LED in dot matrix backlight, using the initial current value of average current value as each LED.

Then, PWM data conversion calculation processing unit, according to the PWM data obtained, makes statistic histogram.

Obtain the maximal value in PWM data and minimum value, calculate the interval value of PWM data; Then, obtain the group number of PWM data according to the group distance preset and the interval value of PWM data, complete the grouping to PWM data; Or obtain the group distance of PWM data according to the group number preset and the interval value of PWM data, complete PWM packet; Then, with the numerical value of PWM data, also namely dutycycle is as horizontal ordinate, and with the occurrence number of PWM data, also namely the quantity of LED, as ordinate, makes and obtains statistic histogram.

Statistic histogram comprises the histogram of each PWM data group, and each histogram comprises in current PWM data group, the occurrence number of PWM data and corresponding PWM numerical value.

Statistic histogram comprises the histogram of each PWM data group, in each histogram graph representation current PWM data group, and the numerical range of PWM data and occurrence number.

Then, in statistic histogram, make electric current straight line according to average current value.Current parameters in each PWM data corresponding current straight line.

Then, according to the rule preset, in electric current straight line, the center equilibrium point of statistic histogram is chosen.

Then, using this center equilibrium point as center, counterclockwise single step rotatory current straight line, the LED making PWM numerical value larger obtains larger current value, the LED that PWM numerical value is less obtains less current value, to strengthen the contrast of light and shadow portion in picture.

In electric current straight line rotary course, PWM data conversion calculation processing unit, according to the postrotational electric current straight line of each single step, calculates the current parameters that each PWM data are corresponding, thus obtains the current parameters of each LED.Then, according to the current parameters of each LED obtained, calculate the power consumed when controlling LED all in dot matrix backlight.

When the power consumed meets pre-configured dot matrix backlight general power, stop the rotation electric current straight line, and with each current parameters of now electric current line correspondences, as the current parameters controlling each LED in dot matrix backlight.

It should be noted that, during rotatory current straight line, the step-length often rotated once is default threshold value, can arrange flexibly according to actual needs.Such as, if desired accelerate the rotational speed of electric current straight line, make the dot matrix backlight general power that the consumed power calculated reaches pre-configured fast, then what the threshold value of rotary step can be arranged is larger; Control the rotational speed of electric current straight line if do not require, in order to carry out control accurate, what the threshold value of rotary step can be arranged is less.

Then, the current parameters of each LED is sent data buffer stored in SPI by PWM data conversion calculation processing unit.Central cpu processing unit controls the drive circuit module that the PWM data of storage and current parameters are sent to each LED by spi bus data transmission unit.

The present embodiment is by obtaining the PWM data of every frame display frame, all PWM data are sent into PWM data conversion calculation processing unit, PWM data conversion calculation processing unit, according to dot matrix backlight drive method provided by the invention, calculates effective control current data of corresponding each LED according to PWM data.Then, the LED current data that PWM data conversion module exports by central cpu processing unit, by spi bus, flushes to the current control circuit of corresponding each LED, in order to control the current value size of each LED.PWM data are flushed to the PWM on-off circuit of corresponding each LED by central cpu processing unit by spi bus, these PWM data are accurately write the driving PWM register of each LED according to the address mapping relation table of LED, in order to regulate the contactor time of each LED, allow the PWM pulse duty cycle of each LED and On current all can free setting like this.

Step S30, independently control described each LED according to described PWM data and described current parameters, drive described dot matrix backlight.

The drive circuit module of LED receives PWM data and the current parameters of each LED in dot matrix backlight, and each LED of independent control, drives dot matrix backlight.

Concrete, as a kind of embodiment, each LED in dot matrix backlight is all configured with independently PWM on-off circuit and current control circuit, with reference to Fig. 2, drive IC (integratedcircuit can be passed through, integrated circuit) indoor design improve realize, or drive IC external circuit design realize.

The drive circuit module of LED, according to the PWM data of each LED obtained, by the PWM on-off circuit of each LED, carries out PWM control to each LED respectively, controls the pulse duty cycle of each LED.

Meanwhile, the drive circuit module of LED, according to the current parameters of each LED obtained, by the current control circuit of each LED, carries out Current Control to each LED respectively.

Thus, the drive circuit module of LED realizes the driving to dot matrix backlight, shows current television image.

In the present embodiment, by each frame picture of Real-time Obtaining TV, and carry out dynamic data analysis and calculating in real time, thus ensure continuity and the high image quality of television image.

In the present embodiment, first, according to the TV signal of input, the pulse width modulation (PWM) data controlling each LED lamp in dot matrix backlight are calculated; Then, according to PWM data, make statistic histogram, and calculate the current parameters controlling each LED according to statistic histogram; Then according to PWM data and the current parameters of each LED, each LED of independent control, drives dot matrix backlight.The present embodiment is by the PWM data creating statistic histogram according to acquisition, thus adjust the current parameters of LED corresponding to each PWM data, achieve and the electric current of LED all in dot matrix backlight is all distributed according to need, under the condition ensureing power consumption, make television image entirety reach optimal display result, avoid power attenuation and energy dissipation.

Further, with reference to Fig. 3, dot matrix backlight drive method second embodiment of the present invention provides a kind of dot matrix backlight drive method, based on the embodiment shown in above-mentioned Fig. 1, described PWM data are each PWM data of each LED in corresponding described dot matrix backlight, and described step S20 comprises:

Step S21, according to described PWM data and pre-configured dot matrix backlight general power, rated voltage, calculate the average current of each LED in dot matrix backlight.

After the PWM data obtaining each LED in dot matrix backlight electric power, PWM data are inputed to PWM data conversion calculation processing unit by the central cpu processing unit of LED drived control administration module, PWM data conversion calculation processing unit is according to the PWM data obtained, and conversion calculates the drive current parameter of each LED.

As a kind of embodiment, PWM data conversion calculation processing unit is according to pre-configured dot matrix backlight general power, with rated supply voltage, PWM data, calculate the average current value of LED in dot matrix backlight, using the initial current value of average current value as each LED.

Concrete computation process is as follows:

First, the mean value of PWM data is calculated according to PWM data.

Get total n LED in current dot matrix backlight, the PWM numerical value of each LED is PWM1, PWM2, PWM3 ... the mean value of PWMn, PWM data is PWM _avg, then according to formula PWM _avg=(PWM1+PWM2+PWM3+ ... + PWMn)/n calculates PWM _avg.

Then, according to pre-configured dot matrix backlight general power, and rated supply voltage, PWM data mean value, calculate the average current value of the maximum permission of current dot matrix backlight.

Getting general power is P, and rated supply voltage is the mean value of V, PWM data is PWM _avg, average current value is I _avg, then according to formula I _avg=P/ (V × PWM _avg) calculate I _avg.

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

Step S22, each PWM data according to each LED in correspondence described dot matrix backlight, make statistic histogram.

PWM data conversion calculation processing unit, according to the PWM data obtained, makes statistic histogram.

First, obtain the maximal value PWMmax in PWM data and minimum value PWMmin, calculate the interval value of PWM data.Interval value can be obtained according to formula PWMmax-PWMmin.

Then, obtain the group number of PWM data according to the group distance preset and the interval value of PWM data, complete the grouping to PWM data; Or obtain the group distance of PWM data according to the group number preset and the interval value of PWM data, complete the grouping to PWM data.

Then, with the numerical value of PWM data, also namely dutycycle is as horizontal ordinate, and with the occurrence number of PWM data, also namely the quantity of LED, as ordinate, makes and obtains statistic histogram.

Statistic histogram comprises the histogram of each PWM data group, in each histogram graph representation current PWM data group, and the numerical range of PWM data and occurrence number.

Step S23, according to described average current, in described statistic histogram, make electric current straight line, the current parameters in described statistic histogram on the corresponding described electric current straight line of each PWM data.

After obtaining statistic histogram, in statistic histogram, make electric current straight line according to average current value.Current parameters in each PWM data corresponding current straight line.

Concrete, as a kind of embodiment, in statistic histogram, according to the horizontal ordinate representing PWM numerical value, be virtual ordinate with the current value that PWM numerical value is corresponding, obtain virtual coordinates axle.

Then, take average current value as ordinate value, the maximal value PWMmax in PWM data and minimum value PWMmin is respectively horizontal ordinate, obtains an A and some B, tie point A and puts B, obtaining electric current straight line AB.

Now, the initial current value of average current value corresponding to each PWM data is also the initial current value of each LED.

As another kind of embodiment, electric current straight line also according to actual needs, can be set to curve, such as 2.2Gamma (gamma) curve, realizes better Picture Showing effect.

The electric current straight line of the present embodiment indication, can be arranged according to actual needs flexibly.

Step S24, counterclockwise single step rotate described electric current straight line, and according to postrotational electric current straight line, calculate the current parameters controlling described each LED.

After acquisition electric current straight line, rotatory current straight line, and according to postrotational electric current straight line, calculate the current parameters controlling each LED in dot matrix backlight.

Concrete, as a kind of embodiment, first, by the rule preset, electric current straight line obtains the center equilibrium point of statistic histogram.

Then, according to the current parameters of each LED obtained, calculate the power consumed when driving LED all in dot matrix backlight.

Thus, PWM data conversion calculation processing unit obtains the current parameters controlling each LED in dot matrix backlight.In the present embodiment, the current parameters obtained is current value, and the current value of each LED is written in the Current Control register corresponding with it by dot matrix backlight driving device.

In the present embodiment, first-selected, PWM data conversion calculation processing unit, according to PWM data and pre-configured dot matrix backlight general power, rated voltage, calculates the average current of each LED in dot matrix backlight; Then, according to each PWM data of each LED of correspondence, make statistic histogram; Then, according to average current, in statistic histogram, make electric current straight line, the current parameters on each PWM data corresponding current straight line; Then, counterclockwise single step rotatory current straight line, and according to postrotational electric current straight line, calculate the current parameters controlling each LED in dot matrix backlight.The present embodiment, by the average current of each LED in dot matrix backlight, determines the initial current of each LED; Then, by electric current straight line by current parameters function to indicate corresponding for each LED, be convenient to regulation and control; When being rotated counterclockwise electric current straight line, the LED making PWM numerical value larger obtains larger current value, more bright, and the LED that PWM numerical value is less obtains less current value, and brightness is lower; By the current parameters of each LED of rotatory current straight line adjustment correspondence, thus the power that each LED is consumed meets the general power pre-set.Thus, the present embodiment, while meeting the general power preset, ensure that the quality of television image, achieves the target of energy-saving and emission-reduction, and environmental protection and simultaneously ensure picture effect improves Consumer's Experience.

Further, with reference to Fig. 4, dot matrix backlight drive method the 3rd embodiment of the present invention provides a kind of dot matrix backlight drive method, and based on the embodiment shown in above-mentioned Fig. 3, described step S24 comprises:

The rule that step S241, basis are preset, described electric current straight line is chosen the center equilibrium point of described statistic histogram.

First, by the rule preset, electric current straight line obtains the center equilibrium point of statistic histogram.

Concrete, as a kind of embodiment, in counting statistics histogram, the quantity of PWM data in each PWM data group, accounts for the number percent of the PWM data total amount of whole LED.Wherein, in each PWM data group, the occurrence number of PWM data is the quantity of PWM data in data group.

After obtaining the highest PWM data group of accounting, choose PWM data in this data group according to preset rules.The selection rule of PWM data can be in data group belonging to it, the intermediate value of PWM data, or the maximal value of PWM data, also can be other numerical value of data group belonging to it.

Then, the current value of the PWM data chosen is set to average current, obtains some C corresponding on electric current straight line.The horizontal ordinate of some C is the PWM numerical value chosen, and ordinate is average current.

Point C is the center equilibrium point of acquisition.After this, the coordinate figure putting C remains unchanged.

As another kind of embodiment, can choose on electric current straight line, 2 Along ents of line segment between some A and some B, as center equilibrium point.

Also according to PWM data cases, any point on line segment AB can be chosen, as center equilibrium point.

The PWM numerical value that the center equilibrium point obtained is corresponding is horizontal ordinate, and average current is ordinate.After this, the coordinate figure of center equilibrium point remains unchanged.

Step S242, with described center equilibrium point for rotary middle point, counterclockwise single step rotates described electric current straight line, and rotary step is default threshold value.

After obtaining center equilibrium point, using this center equilibrium point as rotation center, counterclockwise single step rotatory current straight line.It should be noted that, the rotary step that electric current straight line rotates each time is default threshold value, and rotary step can be arranged flexibly according to the demand of processing speed.Such as, if desired promote processing speed, what the threshold value of rotary step can be arranged is larger; If desired improve processing accuracy, what the threshold value of rotary step can be arranged is less.

Original state due to electric current straight line is parallel with abscissa axis, is therefore rotated counterclockwise the current value making larger PWM numerical value corresponding larger, the current value that less PWM numerical value is corresponding less.

Thereby, it is possible to the LED making PWM numerical value larger obtains larger current value, the LED that PWM numerical value is less obtains less current value, to strengthen the contrast of light and shadow portion in picture.

Step S243, according to the rated current preset, calculate the maximum current parameter of described each LED, and control current parameters corresponding to described each PWM data and be no more than described maximum current parameter and be not less than default minimum current parameter.

When electric current straight line rotates, during for ensureing that the electric current corresponding according to each PWM numerical value of obtaining drives each LED, LED is too bright or too gloomy, therefore maximum current parameter and minimum current parameter is provided with, when ensureing that electric current straight line rotates, the current parameters obtained makes the brightness of LED in the reasonable scope.

Concrete, as a kind of embodiment, first, according to the rated current preset, calculate the maximum current parameter of each LED.

Getting rated current is that I is specified, and the maximal value of PWM data is PWMmax, and the maximum current of LED is Imax, then according to formula:

Imax=I is specified × PWMmax, can be calculated the maximum current value of each LED, also i.e. maximum current parameter.

Therefore, the PWM data corresponding with each LED, current parameters maximal value corresponding on electric current straight line is Imax.

Too not gloomy for ensureing the brightness of each LED, be preset with the minimum current parameter Imin of each LED, can obtain the PWM data that each LED is corresponding thus, current parameters minimum value corresponding on electric current straight line is Imin.

Thus, maximum current parameter corresponding to each PWM data and minimum current parameter is obtained.

When electric current straight line rotates, the current parameters controlling maximum PWM numerical value corresponding is less than or equal to maximum current parameter, and the current parameters that can realize each PWM data corresponding is no more than maximum current parameter; The current parameters controlling minimum PWM numerical value corresponding is more than or equal to minimum current parameter, and the current parameters that can realize each PWM data corresponding is not less than minimum current parameter.

Step S244, according to postrotational electric current straight line, calculate the current parameters controlling described each LED.

After electric current straight line carries out single step rotation at every turn, PWM data conversion calculation processing unit, according to the postrotational electric current straight line of each single step, calculates the current parameters that each PWM data are corresponding, thus obtains the current parameters of each LED.

Then, according to the current parameters of each LED obtained, calculate the power consumed when driving LED all in dot matrix backlight.

Thus, PWM data conversion calculation processing unit obtains the current parameters controlling each LED in dot matrix backlight.Then, the current value of each LED is written in the Current Control register corresponding with it by dot matrix backlight driving device.

In the present embodiment, PWM data conversion calculation processing unit, according to the rule preset, electric current straight line is chosen the center equilibrium point of statistic histogram; Then, with center equilibrium point for rotary middle point, counterclockwise single step rotatory current straight line; According to the rated current preset, calculate the maximum current parameter of each LED, and current parameters corresponding to control PWM data is no more than maximum current parameter and is not less than default minimum current parameter; According to postrotational electric current straight line, calculate the current parameters controlling each LED in dot matrix backlight.The present embodiment, by Selection Center equilibrium point, rotates to be rotating shaft with center equilibrium point, counterclockwise single step rotatory current straight line, and the part making picture bright is brighter, and gloomy part is gloomy, strengthens contrast, ensures that the brightness of LED is in rational scope simultaneously.Drive each LED according to the current parameters obtained, both met pre-configured general power, turn improved image quality.

Further, with reference to Fig. 5, dot matrix backlight drive method the 4th embodiment of the present invention provides a kind of dot matrix backlight drive method, and based on the embodiment shown in above-mentioned Fig. 4, described step S244 comprises:

Step S2441, according to postrotational electric current straight line, calculate the current parameters that described each PWM data are corresponding.

Concrete, as a kind of embodiment, with reference to Fig. 6, represent the electric current straight line of average current value with the straight line z in statistic histogram.

Straight line z is after once single step rotates counterclockwise, and obtain straight line AB, on straight line AB, the current value of corresponding PWM data maximums does not exceed maximum current value, and on straight line AB, the current value of corresponding PWM data minimum value is not lower than minimum current value.

The function of cut-off line AB is y=kx+b, x is PWM numerical value, and y is the current parameters that x is corresponding.

Because center equilibrium point is a C, horizontal ordinate is the PWM numerical value chosen, and ordinate is average current, then the some C coordinate figure on straight line AB is known.

Be preset value because straight line z rotates to the anglec of rotation of straight line AB, then can calculate the value of k.And then the function coordinate figure of a C being substituted into straight line AB calculates, and can obtain the value of b.

Then, due to the k value in function y=kx+b and b value known, each PWM numerical value being substituted into function as x value and calculates, can obtain corresponding y value, is also current parameters.

Thus, obtaining the current parameters that in statistic histogram, each PWM data are corresponding, is also the current parameters of each LED.

Step S2442, calculate the driving power controlling described each LED according to the current parameters of described each PWM data and correspondence.

After obtaining the current parameters that in statistic histogram, each PWM data are corresponding, according to the current parameters of each LED obtained, calculate the power consumed when driving LED all in dot matrix backlight.

Concrete, as a kind of embodiment, get total n LED in current dot matrix backlight, the PWM numerical value of each LED is PWM1, PWM2, PWM3 ... PWMn, current parameters is I1, I2, I3 ... In, rated voltage is V, then according to driving power P1 during following formulae discovery driving dot matrix backlight:

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

Thus, obtain according to the driving power in each PWM data and corresponding current parameters control dot matrix backlight during each LED.

Step S2443, judge whether described driving power reaches described general power.

After the driving power obtaining each LED in driving dot matrix backlight, judge whether reach pre-configured general power when forehead driving power.

Concrete, as a kind of embodiment, pre-configured general power can be arranged according to the actual requirements.According to the value of general power, get default power interval, the performance number in power interval is the performance number reaching general power.Such as, get that power interval is general power 90% to 100%, then the performance number within the scope of this reaches general power, and the performance number being greater than 100% general power or being less than 90% general power does not all reach general power.

According to the driving power value obtained, judge whether driving power reaches general power.

If driving power value is positioned within default power interval, then judge that driving power reaches general power; If driving power is positioned at outside default power interval, then judge that driving power does not reach general power.

Thus, result of determination is obtained.

If the described driving power of step S2444 does not reach described general power, then return execution step: with described center equilibrium point for rotary middle point, counterclockwise single step rotates described electric current straight line; If described driving power reaches described general power, then by current parameters corresponding for described each PWM data, as control described each LED current parameters and store described current parameters.

After obtaining result of determination, if driving power does not reach general power, then control electric current straight line and continue with center equilibrium point for rotation center, counterclockwise single step rotates, and after rotation, again judges whether the driving TV obtained meets general power.

If driving power reaches general power, then stop the rotation electric current straight line, and with each current parameters of now electric current line correspondences, as the current parameters of the PWM data of correspondence, also namely control the current parameters of each LED in dot matrix backlight.

In the present embodiment, PWM data conversion calculation processing unit, according to postrotational electric current straight line, calculates the current parameters that each PWM data are corresponding; According to the current parameters of rated voltage, each PWM data and correspondence, calculate the driving power controlling each LED according to each PWM data and corresponding current parameters; Then, the general power whether driving power reaches pre-configured is judged; If driving power does not reach general power, then continue with center equilibrium point for rotary middle point, counterclockwise single step rotatory current straight line; If driving power reaches general power, then by current parameters corresponding for each PWM data, as controlling the current parameters of each LED and storaging current parameter.The present embodiment is by after the driving power that calculates each LED, determine whether to meet general power, do not meet the current parameters then continuing each LED of adjustment, until meet the general power of configuration according to the driving power of the current parameters configuration obtained, current parameters is now best current arrangements, achieve the optimization collocation of each LED power consumption, avoid the waste of the energy, also ensure that the high image quality of television image simultaneously.

With reference to Fig. 7, dot matrix backlight driving device first embodiment of the present invention provides a kind of dot matrix backlight driving device, and described dot matrix backlight driving device comprises:

Image processing module 100, for the TV signal according to input, calculates the pulse width modulation (PWM) data controlling each LED lamp in dot matrix backlight.

The embodiment of the present invention is mainly used in the driving of dot matrix backlight, while reduction is to power configuration power demand, ensures the picture image quality of display.

The present embodiment drives with the LED dot matrix backlight electric power of televisor and is illustrated.

Concrete, as a kind of embodiment, after televisor starts, the TV signal of every frame television image of image processing module 100 Dynamic Acquisition TV signal source input.

Thus, image processing module 100 obtains the PWM data controlling each LED, and the PWM data obtained are sent to driven management module 200.

Driven management module 200, for according to described PWM data, makes statistic histogram, and calculates the current parameters controlling described each LED according to described statistic histogram.

After driven management module 200 receives the data that image processing module 100 sends, obtain the PWM data of each LED by cis-position sequence through Data Analysis.Then, the PWM data obtained are stored.

After the PWM data obtaining each LED in dot matrix backlight electric power, driven management module 200, according to the PWM data obtained, makes statistic histogram, and calculates the current parameters controlling each LED in dot matrix backlight.

Concrete, as a kind of embodiment, first, driven management module 200 is according to pre-configured dot matrix backlight general power, with rated supply voltage, PWM data, calculate the average current value of LED in dot matrix backlight, using the initial current value of average current value as each LED.

Then, driven management module 200, according to the PWM data obtained, makes statistic histogram.

Statistic histogram comprises the histogram of each PWM data group, and each histogram comprises in current PWM data group, the occurrence number of PWM data and corresponding PWM numerical value.

Statistic histogram comprises the histogram of each PWM data group, in each histogram graph representation current PWM data group, and the numerical range of PWM data and occurrence number.

Then, in statistic histogram, make electric current straight line according to average current value.Current parameters in each PWM data corresponding current straight line.

Then, according to the rule preset, in electric current straight line, the center equilibrium point of statistic histogram is chosen.

In electric current straight line rotary course, driven management module 200, according to the postrotational electric current straight line of each single step, calculates the current parameters that each PWM data are corresponding, thus obtains the current parameters of each LED.Then, according to the current parameters of each LED obtained, calculate the power consumed when controlling LED all in dot matrix backlight.

Thus, driven management module 200 obtains the current parameters controlling each LED in dot matrix backlight.In the present embodiment, the current parameters obtained is current value.

Then, driven management module 200 stores the current parameters of each LED.

Then, the PWM data of storage and current parameters are sent to drive circuit module 300 by driven management module 200.

Drive circuit module 300, for independently controlling described each LED according to described PWM data and described current parameters, drives described dot matrix backlight.

Drive circuit module 300 receives PWM data and the current parameters of each LED in the dot matrix backlight of driven management module 200 transmission, and each LED of independent control, drives dot matrix backlight.

Drive circuit module 300, according to the PWM data of each LED obtained, by the PWM on-off circuit of each LED, carries out PWM control to each LED respectively, controls the pulse duty cycle of each LED.

Meanwhile, drive circuit module 300, according to the current parameters of each LED obtained, by the current control circuit of each LED, carries out Current Control to each LED respectively.

Thus, drive circuit module 300 realizes the driving to dot matrix backlight, shows current television image.

In the present embodiment, first, image processing module 100, according to the TV signal of input, calculates the pulse width modulation (PWM) data controlling each LED lamp in dot matrix backlight; Then, driven management module 200, according to PWM data, makes statistic histogram, and calculates the current parameters controlling each LED according to statistic histogram; Then, drive circuit module 300 is according to the PWM data of each LED and current parameters, and each LED of independent control, drives dot matrix backlight.The present embodiment is by the PWM data creating statistic histogram according to acquisition, thus adjust the current parameters of LED corresponding to each PWM data, achieve and the electric current of LED all in dot matrix backlight is all distributed according to need, under the condition ensureing power consumption, make television image entirety reach optimal display result, avoid power attenuation and energy dissipation.

Further, with reference to Fig. 8, dot matrix backlight driving device second embodiment of the present invention provides a kind of dot matrix backlight driving device, based on the embodiment shown in above-mentioned Fig. 7, described PWM data are each PWM data of each LED in corresponding described dot matrix backlight, and described driven management module 200 comprises:

Electric current averaging unit 210, for according to described PWM data and pre-configured dot matrix backlight general power, rated voltage, calculates the average current of each LED in dot matrix backlight.

After the PWM data obtaining each LED in dot matrix backlight electric power, driven management module 200 calculates the drive current parameter of each LED.

As a kind of embodiment, electric current averaging unit 210 is according to pre-configured dot matrix backlight general power, with rated supply voltage, PWM data, calculate the average current value of LED in dot matrix backlight, using the initial current value of average current value as each LED.

Concrete computation process is as follows:

First, the mean value of PWM data is calculated according to PWM data.

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

Histogram production unit 220, for each PWM data according to each LED in correspondence described dot matrix backlight, makes statistic histogram.

Histogram production unit 220, according to the PWM data obtained, makes statistic histogram.

First, obtain the maximal value PWMmax in PWM data and minimum value PWMmin, calculate the interval value of PWM data.Interval value can be obtained according to formula PWMmax-PWMmin.

Statistic histogram comprises the histogram of each PWM data group, in each histogram graph representation current PWM data group, and the numerical range of PWM data and occurrence number.

Electric current straight line units 230, for according to described average current, makes electric current straight line in described statistic histogram, the current parameters in described statistic histogram on the corresponding described electric current straight line of each PWM data.

After obtaining statistic histogram, electric current straight line units 230, in statistic histogram, makes electric current straight line according to average current value.Current parameters in each PWM data corresponding current straight line.

Now, the initial current value of average current value corresponding to each PWM data is also the initial current value of each LED.

As another kind of embodiment, electric current straight line also according to actual needs, can be set to curve, such as 2.2Gamma (gamma) curve, realizes better Picture Showing effect.

The electric current straight line of the present embodiment indication, can be arranged according to actual needs flexibly.

Single step rotary unit 240, rotates described electric current straight line for counterclockwise single step, and according to postrotational electric current straight line, calculates the current parameters controlling described each LED.

After acquisition electric current straight line, single step rotary unit 240 rotatory current straight line, and according to postrotational electric current straight line, calculate the current parameters controlling each LED in dot matrix backlight.

Concrete, as a kind of embodiment, first, by the rule preset, single step rotary unit 240 obtains the center equilibrium point of statistic histogram on electric current straight line.

In electric current straight line rotary course, single step rotary unit 240, according to the postrotational electric current straight line of each single step, calculates the current parameters that each PWM data are corresponding, thus obtains the current parameters of each LED.

Then, according to the current parameters of each LED obtained, calculate the power consumed when driving LED all in dot matrix backlight.

Thus, single step rotary unit 240 obtains the current parameters controlling each LED in dot matrix backlight.In the present embodiment, the current parameters obtained is current value.

Then, single step rotary unit 240 stores the current parameters of each LED obtained.

In the present embodiment, first-selected, electric current averaging unit 210, according to PWM data and pre-configured dot matrix backlight general power, rated voltage, calculates the average current of each LED in dot matrix backlight; Then, histogram production unit 220, according to each PWM data of each LED of correspondence, makes statistic histogram; Then, electric current straight line units 230, according to average current, makes electric current straight line in statistic histogram, the current parameters on each PWM data corresponding current straight line; Then, single step rotary unit 240 is single step rotatory current straight line counterclockwise, and according to postrotational electric current straight line, calculates the current parameters controlling each LED in dot matrix backlight.The present embodiment, by the average current of each LED in dot matrix backlight, determines the initial current of each LED; Then, by electric current straight line by current parameters function to indicate corresponding for each LED, be convenient to regulation and control; When being rotated counterclockwise electric current straight line, the LED making PWM numerical value larger obtains larger current value, more bright, and the LED that PWM numerical value is less obtains less current value, and brightness is lower; By the current parameters of each LED of rotatory current straight line adjustment correspondence, thus the power that each LED is consumed meets the general power pre-set.Thus, the present embodiment, while meeting the general power preset, ensure that the quality of television image, achieves the target of energy-saving and emission-reduction, and environmental protection and simultaneously ensure picture effect improves Consumer's Experience.

Further, with reference to Fig. 9, dot matrix backlight driving device the 3rd embodiment of the present invention provides a kind of dot matrix backlight driving device, and based on the embodiment shown in above-mentioned Fig. 8, described single step rotary unit 240 comprises:

Central point subelement 241, for according to the rule preset, described electric current straight line is chosen the center equilibrium point of described statistic histogram.

First, by the rule preset, central point subelement 241 obtains the center equilibrium point of statistic histogram on electric current straight line.

Concrete, as a kind of embodiment, in central point subelement 241 counting statistics histogram, the quantity of PWM data in each PWM data group, accounts for the number percent of the PWM data total amount of whole LED.Wherein, in each PWM data group, the occurrence number of PWM data is the quantity of PWM data in data group.

Point C is the center equilibrium point of acquisition.After this, the coordinate figure putting C remains unchanged.

As another kind of embodiment, central point subelement 241 can be chosen on electric current straight line, and 2 Along ents of line segment between some A and some B, as center equilibrium point.

Also according to PWM data cases, any point on line segment AB can be chosen, as center equilibrium point.

Gyrator unit 242, for described center equilibrium point for rotary middle point, counterclockwise single step rotates described electric current straight line, and rotary step is default threshold value.

After obtaining center equilibrium point, gyrator unit 242 using this center equilibrium point as rotation center, counterclockwise single step rotatory current straight line.It should be noted that, the rotary step that electric current straight line rotates each time is default threshold value, and rotary step can be arranged flexibly according to the demand of processing speed.Such as, if desired promote processing speed, what the threshold value of rotary step can be arranged is larger; If desired improve processing accuracy, what the threshold value of rotary step can be arranged is less.

Border subelement 243, for according to the rated current preset, calculates the maximum current parameter of described each LED, and controls current parameters corresponding to described each PWM data and be no more than described maximum current parameter and be not less than default minimum current parameter.

Concrete, as a kind of embodiment, first, border subelement 243, according to the rated current preset, calculates the maximum current parameter of each LED.

Getting rated current is that I is specified, and the maximal value of PWM data is PWMmax, and the maximum current of LED is Imax, then according to formula:

Imax=I is specified × PWMmax, can be calculated the maximum current value of each LED, also i.e. maximum current parameter.

Therefore, the PWM data corresponding with each LED, current parameters maximal value corresponding on electric current straight line is Imax.

Thus, border subelement 243 obtains maximum current parameter corresponding to each PWM data and minimum current parameter.

When electric current straight line rotates, the current parameters that border subelement 243 controls maximum PWM numerical value corresponding is less than or equal to maximum current parameter, and the current parameters that can realize each PWM data corresponding is no more than maximum current parameter; The current parameters controlling minimum PWM numerical value corresponding is more than or equal to minimum current parameter, and the current parameters that can realize each PWM data corresponding is not less than minimum current parameter.

Computation subunit 244, for according to postrotational electric current straight line, calculates the current parameters controlling described each LED.

After electric current straight line carries out single step rotation at every turn, computation subunit 244, according to the postrotational electric current straight line of each single step, calculates the current parameters that each PWM data are corresponding, thus obtains the current parameters of each LED.

Then, according to the current parameters of each LED obtained, calculate the power consumed when driving LED all in dot matrix backlight.

Thus, computation subunit 244 obtains the current parameters controlling each LED in dot matrix backlight.

Then, computation subunit 244 stores the current parameters of each LED.

In the present embodiment, central point subelement 241, according to the rule preset, electric current straight line is chosen the center equilibrium point of statistic histogram; Then, gyrator unit 242 with center equilibrium point for rotary middle point, counterclockwise single step rotatory current straight line; Border subelement 243, according to the rated current preset, calculates the maximum current parameter of each LED, and current parameters corresponding to control PWM data is no more than maximum current parameter and is not less than default minimum current parameter; Computation subunit 244, according to postrotational electric current straight line, calculates the current parameters controlling each LED in dot matrix backlight.The present embodiment, by Selection Center equilibrium point, rotates to be rotating shaft with center equilibrium point, counterclockwise single step rotatory current straight line, and the part making picture bright is brighter, and gloomy part is gloomy, strengthens contrast, ensures that the brightness of LED is in rational scope simultaneously.Drive each LED according to the current parameters obtained, both met pre-configured general power, turn improved image quality.

Further, with reference to Figure 10, dot matrix backlight driving device the 4th embodiment of the present invention provides a kind of dot matrix backlight driving device, and based on the embodiment shown in above-mentioned Fig. 9, described computation subunit 244 comprises:

First computation subunit 2441, for according to postrotational electric current straight line, calculates the current parameters that described each PWM data are corresponding.

Concrete, as a kind of embodiment, with reference to Fig. 6, represent the electric current straight line of average current value with the straight line z in statistic histogram.

The function of the first computation subunit 2441 cut-off line AB is y=kx+b, x is PWM numerical value, and y is the current parameters that x is corresponding.

Because center equilibrium point is a C, horizontal ordinate is the PWM numerical value chosen, and ordinate is average current, then the some C coordinate figure on straight line AB is known.

Thus, the first computation subunit 2441 obtains the current parameters that in statistic histogram, each PWM data are corresponding, is also the current parameters of each LED.

Second power subelement 2442, for the current parameters according to described rated voltage, described each PWM data and correspondence, calculates the driving power controlling described each LED according to described each PWM data and corresponding current parameters.

After obtaining the current parameters that in statistic histogram, each PWM data are corresponding, the second power subelement 2442, according to the current parameters of each LED obtained, calculates the power consumed when driving LED all in dot matrix backlight.

Concrete, as a kind of embodiment, total n LED in current dot matrix backlight got by second power subelement 2442, the PWM numerical value of each LED is PWM1, PWM2, PWM3 ... PWMn, current parameters is I1, I2, I3 ... In, rated voltage is V, then according to driving power P1 during following formulae discovery driving dot matrix backlight:

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

Thus, the second power subelement 2442 obtains according to the driving power in each PWM data and corresponding current parameters control dot matrix backlight during each LED.

3rd judgment sub-unit 2443, for judging whether described driving power reaches described general power.

After the driving power obtaining each LED in driving dot matrix backlight, the 3rd judgment sub-unit 2443 judges whether reach pre-configured general power when forehead driving power.

3rd judgment sub-unit 2443, according to the driving power value obtained, judges whether driving power reaches general power.

Thus, the 3rd judgment sub-unit 2443 obtains result of determination.

4th obtain subelement 2444, if reach described general power for described driving power, then by current parameters corresponding for described each PWM data, as control described each LED current parameters and store described current parameters.

If driving power meets general power, then the 4th obtain subelement 2444 and to stop the rotation electric current straight line, and with each current parameters of now electric current line correspondences, as the current parameters of the PWM data of correspondence, also namely control the current parameters of each LED in dot matrix backlight.

Thus, the 4th the current parameters that subelement 2444 obtains controlling each LED in dot matrix backlight is obtained.

Then, the 4th the current parameters that subelement 2444 stores each LED is obtained.

Described gyrator unit 242, if also do not meet described general power for described driving power, then with described center equilibrium point for rotary middle point, counterclockwise single step rotates described electric current straight line.

After obtaining result of determination, if driving power does not reach general power, then gyrator unit 242 controls the continuation of electric current straight line with center equilibrium point for rotation center, and counterclockwise single step rotates, after rotation, the 3rd judgment sub-unit 2443 judges whether the driving TV obtained meets general power again.

In the present embodiment, the first computation subunit 2441, according to postrotational electric current straight line, calculates the current parameters that each PWM data are corresponding; Second power subelement 2442, according to the current parameters of rated voltage, each PWM data and correspondence, calculates the driving power controlling each LED according to each PWM data and corresponding current parameters; Then, the 3rd judgment sub-unit 2443 judges the general power whether driving power reaches pre-configured; If driving power does not reach general power, then gyrator unit 242 continues with center equilibrium point for rotary middle point, counterclockwise single step rotatory current straight line; If driving power reaches general power, then the 4th obtain subelement 2444 by current parameters corresponding for each PWM data, as controlling the current parameters of each LED and storaging current parameter.The present embodiment is by after the driving power that calculates each LED, determine whether to meet general power, do not meet the current parameters then continuing each LED of adjustment, until meet the general power of configuration according to the driving power of the current parameters configuration obtained, current parameters is now best current arrangements, achieve the optimization collocation of each LED power consumption, avoid the waste of the energy, also ensure that the high image quality of television image simultaneously.

With reference to Figure 11, dot matrix backlight drive system first embodiment of the present invention provides a kind of dot matrix backlight drive system, described dot matrix backlight drive system comprises television video image procossing MEMC modules A, LED lamp drived control administration module B and LED lamp drive circuit module C, wherein:

Described television video image procossing MEMC modules A, for the TV signal according to input, calculates the pulse width modulation (PWM) data controlling each LED lamp in dot matrix backlight; Described PWM data are sent to described LED drived control administration module B.

After televisor starts, TV video processor front end, also the TV signal of every frame television image of i.e. television video image procossing MEMC (MotionEstimateandMotionCompensation, Motion estimation and compensation) the modules A Dynamic Acquisition TV signal source input of central processor CPU.

When the PWM data of all LED calculate complete, then start data transmission blocks immediately, as host computer, then data are sent to the LED drived control administration module B of LED array light source drive plate by the data encoding packing that first will send by spi bus.

Described LED drived control administration module B, for receiving the described PWM data that described television video image procossing MEMC modules A sends; According to described PWM data, make statistic histogram, and calculate the current parameters controlling described each LED according to described statistic histogram; Described PWM data and described current parameters are sent to described LED lamp drive circuit module C.

LED drived control administration module B is positioned at the drive plate of LED array light source, for receiving the PWM data that television video image procossing MEMC modules A sends, carry out analysis and calculation, obtain the optimum current controling parameters of each LED in dot matrix backlight, and PWM data and current parameters are sent to LED lamp drive circuit module C.

After LED drived control administration module B receives and parses each PWM data that host computer sends, two parts are divided into use and process this data.Part I is the driving PWM register directly each PWM data accurately being write each LED according to the address mapping relation table of the LED of correspondence, to determine the switching time of each LED; Another part is then used to the current parameters calculating each LED, is also current value, is then written in the Current Control register corresponding with it by the current value of each LED.

Such as, for the dot matrix backlight of configuration 288 LED lamp, by dot matrix backlight drive method embodiment of the present invention, calculate the current value that each LED is mated with its PWM dutycycle, then these 288 current values are written in the Current Control register of 288 corresponding LED, each LED is made to have a Current Control value, thus change prior art and allow same group of LED of all LED or regional area all use the way of same current value, not only improve picture effect but also avoid power attenuation and energy dissipation.

Concrete, as a kind of embodiment, first, PWM data are converted to the current parameters of corresponding each LED by LED drived control administration module B.Then each LED current parameters obtained is flushed to current driving circuit corresponding to each LED by spi bus by LED drived control administration module B, in order to control the current value size of each LED.

Meanwhile, received PWM data are directly flushed to PWM ON-OFF control circuit corresponding to each LED by spi bus by LED drived control administration module B, in order to regulate the contactor time of each LED.

Like this, allow the PWM dutycycle of each LED and On current all can free setting.

Wherein, PWM data are converted to the concrete computation process of current parameters of corresponding each LED by LED drived control administration module B, to configure the dot matrix backlight of 288 LED lamp, are illustrated.

It is 420W that televisor configures to the spendable power of work of all LED on LED dot matrix backlight driver plate, and the general power also namely configured is 420W.

Namely the supply voltage adding upper conductor due to LED is 9V, and also rated voltage is 9V, then all LED spendable maximum current that normally works is 420/9 ≈ 47A.

PWM data for all LED are all the situations of 100% dutycycle, and the setting electric current of each LED can not more than 47A/288*100%=163mA, otherwise can make the use power of whole dot matrix backlight driver plate exceed dispensing.And for an abundant in content natural picture, not every PWM data are all 100%, but various composition has, if at this moment still adopt unified current arrangements mode, then picture can be made to have the common situation that bright place is bright not, this dark place is dark not.The region of especially dark picture, the electric current of lamp is also configure very high, causes unnecessary waste.Because the maximum rated current of each LED can arrive 340mA, and bright place is large not because electric current is defined, and light-source brightness is not fully used.

When driving power is no more than general power, optimum amounts of current is assigned in order to each LED can be made, the PWM data of each LED received are set up a statistic histogram by LED drived control administration module B, horizontal ordinate is PWM data, also be dutycycle, ordinate is the quantity of LED.LED for high duty ratio distributes larger electric current, make these LED luminescences the strongest, such as 100% be assigned to is 340mA to the maximum, for the current value that the distribution of low duty ratio is lower, these LED are made to coordinate image content luminescence comparatively dark, by that analogy, when driving power is no more than the general power of configuration, calculate the current value of all LED, thus complete and coordinate picture actual content distribution according to need electric current, thus maximal efficiency make use of LED light source and power.

Described LED lamp drive circuit module C, for receiving the described PWM data of described LED drived control administration module B transmission and described electric current; Independently control described each LED according to described PWM data and described current parameters, drive described dot matrix backlight.

The drive circuit module C of LED receives PWM data and the current parameters of each LED in the dot matrix backlight of LED drived control administration module B transmission, and each LED of independent control, drives dot matrix backlight.

The drive circuit module C of LED, according to the PWM data of each LED obtained, by the PWM on-off circuit of each LED, carries out PWM control to each LED respectively, controls the pulse duty cycle of each LED.

Meanwhile, the drive circuit module C of LED, according to the current parameters of each LED obtained, by the current control circuit of each LED, carries out Current Control to each LED respectively.

Thus, the drive circuit module C of LED realizes the driving to dot matrix backlight, shows current television image.

In the present embodiment, dot matrix backlight drive system, by the TV signal of television video image procossing MEMC modules A according to input, calculates the pulse width modulation (PWM) data controlling each LED lamp in dot matrix backlight; Then LED drived control administration module B is according to PWM data, makes statistic histogram, and calculates the current parameters controlling each LED in dot matrix backlight according to statistic histogram; Then, LED lamp drive circuit module C, according to the PWM data obtained and current parameters, independently controls PWM and the electric current of each LED, thus drives dot matrix backlight.The present embodiment achieves and controls the independence of LED each in dot matrix backlight, coordinate television image actual content distribution according to need electric current, maximal efficiency make use of LED light source and power.

Further, with reference to Figure 12, backlight drive system second embodiment of the present invention provides a kind of backlight drive system, based on the embodiment shown in above-mentioned Figure 11, described LED drived control administration module B comprises serial peripheral equipment interface SPI bus data receiving element B1, SPI and receives data buffer B2, central cpu processing unit B3, PWM data conversion calculation processing unit B4, SPI transmission data buffer B5 and spi bus data transmission unit B6, wherein:

Described spi bus data receipt unit B1, for receiving the PWM data that described television video image procossing MEMC modules A sends.

In the present embodiment, LED drived control administration module B is positioned on the drive plate of LED array light source, undertaken alternately by SPI (SerialPeripheralInterface, Serial Peripheral Interface (SPI)) bus and television video image procossing MEMC modules A and LED lamp drive circuit module C.

PWM data are calculated in television video image procossing MEMC modules A, by the packing of PWM data and sent to the drive plate of LED array light source by spi bus after, spi bus data receipt unit B1 receives the PWM packet that television video image procossing MEMC modules A sends.

Central cpu processing unit B3 resolves the PWM packet obtained, and obtains each PWM data in PWM packet.

Described SPI receives data buffer B2, for storing described PWM data.

After the PWM data obtaining the transmission of television video image procossing MEMC modules A, SPI receives the PWM data that data buffer B2 storage obtains, for follow-up Data Analysis Services.

Described central cpu processing unit B3, for controlling, coordinating the process of described PWM data.

Central cpu processing unit B3 is for controlling, coordinating the work of each unit in LED drived control administration module B.

Concrete, central cpu processing unit B3 controls the PWM packet that spi bus data receipt unit B1 receives the transmission of television video image procossing MEMC modules A.

Then, central cpu processing unit B3 resolves PWM packet and obtains respectively by the PWM data of cis-position sequence, and each PWM data are received data buffer B2 stored in SPI.

Then, each PWM data send to PWM data to change calculation processing unit B4 by central cpu processing unit B3, change by PWM data the current parameters that calculation processing unit B4 process calculates each LED, and each LED current parameters obtained is sent data buffer stored in SPI.

Thus, the PWM data and the current parameters that control each LED is obtained.

Then, central cpu processing unit controls the drive circuit module C that the PWM data of storage and current parameters are sent to each LED by spi bus data transmission unit B6, to control each LED.

Described PWM data conversion calculation processing unit B4, for according to described PWM data, makes statistic histogram, and calculates the current parameters controlling described each LED according to described statistic histogram.

PWM data conversion calculation processing unit B4, after the PWM data that the LED obtaining central cpu processing unit B3 transmission is corresponding, makes statistic histogram, calculates the current parameters of the correspondence controlling each LED.

Concrete, as a kind of embodiment, first, PWM data conversion calculation processing unit B4, according to each PWM data and pre-configured dot matrix backlight general power, rated voltage, calculates the average current of each LED in dot matrix backlight.

Then, according to each PWM data of each LED in corresponding dot matrix backlight, make statistic histogram, obtain the distribution situation of PWM data.

Then, PWM data conversion calculation processing unit B4, according to the average current of each LED, makes electric current straight line, the current parameters in statistic histogram on each PWM data corresponding current straight line in statistic histogram.

Then, according to the rule preset, electric current straight line is chosen the center equilibrium point of statistic histogram, and the coordinate of this center equilibrium point is known, and remains unchanged.

Then, with the center equilibrium point chosen for rotary middle point, counterclockwise single step rotatory current straight line, rotary step is default threshold value.Rotatory current straight line is to make the current parameters that larger PWM numerical value is corresponding larger, and the current parameters that less PWM numerical value is corresponding is less, thus the part making television image bright is brighter, and gloomy part is more gloomy, strengthens contrast.

In rotary course, the boundary value of the current parameters that control PWM numerical value is corresponding, to make current parameters corresponding to each PWM data be no more than maximum current value, is not less than minimum current value, ensures the brightness of picture in the reasonable scope.

Then, according to the electric current straight line obtained after rotation, the current parameters controlling described each LED is calculated.And according to the current parameters obtained, judge to drive the power consumed during dot matrix backlight whether to meet the general power preset according to the current parameters obtained.

If the power consumed does not meet the general power preset, then continue rotatory current straight line; If the power consumed meets default general power, then according to the current parameters now obtained, as the current parameters of each LED of correspondence, and SPI is sent to by current parameters to send data buffer B5.

Described SPI sends data buffer B5, for storing described current parameters.

The current parameters that each LED that SPI transmission data buffer B5 reception PWM data conversion calculation processing unit B4 sends is corresponding, and store.

Described spi bus data transmission unit B6, for sending to described LED lamp drive circuit module C by described PWM data and described current parameters.

The PWM data of storage and current parameters are sent to corresponding each LED by spi bus data transmission unit B6 respectively.

Concrete, as a kind of embodiment, each PWM data, according to the address mapping relation table of each LED, are accurately write the driving PWM register of each LED by spi bus data transmission unit B6, to determine the switching time of described each LED

The current value of each LED is written in the Current Control register corresponding with it by spi bus data transmission unit B6.Such as: for the dot matrix backlight of configuration 288 LED, each LED and its PWM data are calculated by dot matrix backlight drive method provided by the invention, also be the current value of dutycycle coupling, then start spi bus data transmission unit B6 these 288 current values to be written in the Current Control register of 288 corresponding LED, make each lamp have a Current Control value.

In the present embodiment, LED drived control administration module B comprises spi bus data receipt unit, SPI receives data buffer, central cpu processing unit, PWM data conversion calculation processing unit, SPI send data buffer and spi bus data transmission unit, achieves the PWM data receiving television video image procossing MEMC modules A and send; And according to PWM data, make statistic histogram, and calculate the current parameters controlling each LED in dot matrix backlight according to statistic histogram; Then, PWM data and current parameters are sent to LED lamp drive circuit module C.The present embodiment changes prior art allows same group of LED of all LED or regional area all use the way of same current value, achieve and the electric current of LED all in dot matrix backlight is all distributed according to need, under the condition ensureing power consumption, make television image entirety reach optimal display result, avoid power attenuation and energy dissipation.

These are only the preferred embodiments of the present invention; not thereby the scope of the claims of the present invention is limited; every utilize instructions of the present invention and accompanying drawing content to do equivalent structure or equivalent flow process conversion; or be directly or indirectly used in other relevant technical fields, be all in like manner included in scope of patent protection of the present invention.