CN101937652B

CN101937652B - Method for counting backlight of direct type white LED backlight

Info

Publication number: CN101937652B
Application number: CN 201010293070
Authority: CN
Inventors: 唐益绍
Original assignee: Irico Group Corp
Current assignee: Irico Group Corp
Priority date: 2010-09-27
Filing date: 2010-09-27
Publication date: 2013-07-03
Anticipated expiration: 2030-09-27
Also published as: CN101937652A

Abstract

The invention discloses a method for counting backlight of a direct type white LED backlight, which comprises the following steps of: firstly, partitioning an LCD panel and establishing a partition look-up table; secondly, driving a white LED lamp to lighten, detecting ambient brightness, and then transmitting detected data to a control unit; thirdly, working out the corresponding data and resolution values of RGB three colors from the detected data by the control unit; fourthly, counting a grey valve of each pixel point data in a video signal by a control component to obtain brightness values of actually lightened backlight; fifthly, comparing the brightness values of pixel points in the same zone according to the partitioned zone and taking the maximum value as brightness reference value in the zone by the control component; and finally, caching the brightness reference value and outputting a drive signal value corresponding to the brightness reference value to an LED drive chip to drive the white LED lamp to lighten by the control component.

Description

A kind of direct type white light LED backlight source computing method backlight

Technical field

The present invention relates to a kind of direct type white light LED backlight source computing method backlight.

Background technology

Present stage, liquid crystal indicator has been widely used in the individual consumer's goods such as notebook computer, computer monitor, TV because in light weight, advantages such as volume is little, little power consumption, radiation is low, quality is good are arranged.Because LCD panel itself does not have the characteristics of luminescence, therefore must add a light emitting source at the LCD panel, can reach display effect, backlight source module namely provides the optical module of LCD display back light.

The LCD backlight source module can use light emitting diode (LED), cold-cathode fluorescence lamp (CCFL), external electrode fluorescent lamp (EFFL) etc. as light source.

The backlight of giant-screen LCD main flow remains CCFL on the market, but along with development of semiconductor, the particularly appearance of high-power LED chip, LED brightness and efficient have had significant raising, make the LED-backlit source more and more be applied to LCD backlight in.The most tangible characteristics of led light source are expansions of colour gamut, and the reduction of power consumption.Use LED-backlit to have broader colour gamut, realize more gorgeous color.The LCD TV of the CCFL backlight of comparing traditional, white light LEDs backlight can guaranteed under the prerequisite of brightness, with very little driving voltage, drive white LED lamp and light, and can save power consumption by corresponding control method.Under identical operating position, white LED lamp has longer serviceable life than CCFL fluorescent tube.

For the LED-backlit source, therefore the brightness value in order to ensure can effectively calculate single pixel when calculating each regional backlight brightness values, is necessary to provide a kind of white light LEDs backlight statistical method backlight in fact.

Summary of the invention

Technical matters to be solved by this invention provides a kind of direct type white light LED backlight source computing method backlight, this method can be controlled the white LED lamp array and realize backlight lighting, control backlight, thus convert the control of lighting that single gray value data realizes white light LEDs to by the RGB three chromatic numbers certificate with standard.

For solving above technical matters, the invention provides a kind of direct type white light LED backlight source computing method backlight, may further comprise the steps:

(1) whole LCD panel is carried out subregion according to resolution, and set up the subregion look-up table;

(2) start drives white LED lamp according to reset values and lights, and makes led array output start brightness, and the brightness of light sensor detecting unit testing environment will detect data then and send to control module simultaneously;

(3) control device of control module receives and detects the vision signal that reads the video decode plate after the data, and then, control device solves data and the resolution value of corresponding RGB three looks from vision signal, and vision signal is carried out buffer memory;

(4) control device carries out the brightness value statistics to the data based formula of each pixel () in the vision signal, and the brightness value that calculates is the actual brightness value of lighting of backlight:

Bright=0.288*R+0.600*G+0.120*B formula (one)

Wherein, Bright is final brightness value, and R is the red brightness value of pixel, and G is the green brightness value of pixel, and B is the blue brightness value of pixel, and 0.288,0.600,0.120 is three kinds of color-ratio coefficients of RGB;

(5) zone divided according to step (1) of control device compares the brightness value of pixel in the same area, then, with the maximal value of brightness value as the brightness value benchmark in the one's respective area;

(6) control device carries out buffer memory with the brightness value benchmark that step (5) obtains;

(7) control device the corresponding drive signal value of brightness value benchmark that step (5) is obtained outputs to LED and drives in the chip, and the driving LED lamp is lighted.

Compared with prior art, direct type white light LED backlight of the present invention source computing method backlight have the following advantages at least: the present invention is by seeking out minimum brightness value in the zone of all divisions, and with it as the brightness value benchmark, thereby control LED drives chip.This method control white LED lamp array is realized backlight lighting, control backlight, thus convert the control of lighting that single gray value data realizes white light LEDs to by the RGB three chromatic numbers certificate with standard.

Description of drawings

Fig. 1 is the process flow diagram of the inventive method;

Fig. 2 is liquid crystal display block plan of the present invention.

Embodiment

Below in conjunction with illustrated in figures 1 and 2, be described in detail at statistical method of the present invention:

See also Figure 1 and Figure 2, direct type white light LED backlight of the present invention source computing method backlight may further comprise the steps:

(2) start drives white LED lamp according to reset values and lights, and makes led array output start brightness, and the brightness of light sensor detecting unit testing environment will detect data then and send to control module simultaneously, and described reset values is 50% brightness;

(3) control device of control module (be example with FPGA) receives and detects the vision signal that reads the video decode plate after the data, then, control device FPGA solves data and the resolution value of corresponding RGB three looks from vision signal, and vision signal is carried out buffer memory;

(4) the data based formula of each pixel () carries out the brightness value statistics in the vision signal of control device FPGA, and the brightness value that calculates is the actual brightness value of lighting of backlight:

Bright=0.288*R+0.600*G+0.120*B formula (one)

(5) zone divided according to step (1) of control device FPGA compares the brightness value of pixel in the same area, then, with the maximal value of brightness value as the brightness value benchmark in the one's respective area;

(6) control device FPGA carries out buffer memory with the brightness value benchmark that step (5) obtains;

(7) control device FPGA the corresponding drive signal value of brightness value benchmark that step (5) is obtained outputs to LED and drives in the chip, and the driving LED lamp is lighted.

By above step as can be known, the inventive method at first will be gone the LED lamp being driven under the prerequisite light vision signal is incorporated among the control module FPGA, the signal of introducing is the 28bits LVDS signal that video signal processing unit is exported for the video decode plate, comprising 8bits redness, 8bits green, 8bits blue signal, and 1bit HSYNC, 1bit VSYNC, 1bit Reset, 1bit Blank.Before these methods analyst data, at first to carry out subregion according to resolution to whole LCD panel, and set up the subregion look-up table, LCD panel with 1366*768 resolution is example, according to nine white LED lamps mode that is a driving group, its zonule that to be divided into 50 resolution sizes be 137*154 with the LCD panel, with each zonule numbering, and set up the partition information look-up table according to partition number, then the HSYNC in the vision signal and VSYNC signal are analyzed, what judge that current needs adjust color according to the data of analyzing is which zone of LCD panel, guarantees this zone LED lamp is driven the accuracy of chip adjustment with this.The subregion example as shown in Figure 2, comprising LED lamp array 1, LCD panel 2, subregion scope 3, partition number 4.

When doing the pixel brightness statistics, there is the several method can reference, the one, the data of three kinds of color RGB three looks are added up and average, with the brightness value of this mean value as this pixel, advantage is simple, shortcoming is when this pixel is monochrome image, can obviously reduce the brightness value of this point; The 2nd, get the maximal value of three kinds of color RGB brightness as the brightness value of this pixel, advantage is that device realizes simple, shortcoming is that two adjacent sectors can not have tangible brightness value excessive.The method that this patent proposes is to take all factors into consideration the ratio of three kinds of colors of RGB in the addition anabolic process to arrange, calculate brightness value according to different ratio values, can take all factors into consideration the brightness value of three kinds of colors like this, and can not cause problem, the formula of institute's foundation such as the above-mentioned formula (1) of above two kinds of methods.

The above only is one embodiment of the present invention, it or not whole or unique embodiment, the conversion of any equivalence that those of ordinary skills take technical solution of the present invention by reading instructions of the present invention is claim of the present invention and contains.

Claims

1. direct type white light LED backlight source computing method backlight may further comprise the steps:

Bright=0.288*R+0.600*G+0.120*B formula (one)

2. direct type white light LED backlight source as claimed in claim 1 computing method backlight is characterized in that: the reset values of the start described in the described step (2) is 50% brightness or 30% brightness.

3. direct type white light LED backlight source as claimed in claim 2 computing method backlight, it is characterized in that: vision signal described in the described step (3) is not for there being the treated original RGB three chromatic number numbers of it is believed that.