CN106817811A - Based on the method that PWM four primaries LED realizes full gamut scope luminous intensity distribution - Google Patents

Abstract

The invention discloses a kind of method for realizing full gamut scope luminous intensity distribution based on PWM four primaries LED, comprise the following steps：(1) each monochromatic light measurement and colorimetric performance parameter, are obtained；(2) corresponding each monochromatic tristimulus values, is calculated；(3), according to luminous flux and dutycycle direct proportionality, the functional relation of luminous flux and dutycycle is derived；(4) each monochromatic ratio in three primary colours mixed light Mathematical Modeling and mixed light, is obtained, colour mixture equation group is obtained；(5) target color coordinates, the colour temperature of mixed light, are determined；(6) functional relation of chromaticity coordinate, luminous flux and dutycycle, is derived；(7), determine the luminous flux of target colour temperature, calculate each dutycycle of RGBW, finally export, reach luminous intensity distribution purpose.The features such as present invention has easy product low cost, adjustable color temperature high precision, mode, comfortable illumination and good using effect.

Description

Based on the method that PWM four primaries LED realizes full gamut scope luminous intensity distribution

Technical field

It is specifically a kind of to realize that full gamut scope is matched somebody with somebody based on PWM four primaries LED the present invention relates to LED mixed light technologies The method of light.

Background technology

With the progressively development of LED illumination, LED has been widely used in the fields such as China's indoor and outdoor lighting, has been substituted The conventional illumination devices such as incandescent lamp, fluorescent lamp, the representative as energy-saving and environmental protection, intelligent lighting.Wherein, the hair of intelligent lighting Exhibition advantage is fairly obvious, then cooperated with LED it is inherent the characteristics of, the light for sending can be converged preferably so that LED intelligent lamps An important application as field of LED illumination, is widely used in the occasions such as super business, household, office, landscape, before market development Scape is considerable.

Intelligent lamp light modulation toning is main currently on the market uses RGB three primary colours luminous intensity distributions, although can meet user situation illumination Demand, but using RGB match colors intelligent lamp have colour temperature not precisely, the low shortcoming of luminous flux, it is impossible to meet client substantially according to Bright demand.The lighting quality of the light quality especially white light of intelligent lamp illumination how is improved, makes photoenvironment more comfortable, be good for Health, intelligence become the focus of research.

The content of the invention

It is an object of the invention to overcome the shortcomings of that above prior art is present, there is provided a kind of product low cost, can Color-temperature regulating high precision, mode are easy, illumination is comfortable and using effect is good realizes that full gamut scope is matched somebody with somebody based on PWM four primaries LED The method of light.

In order to achieve the above object, the present invention uses following technical scheme：Full gamut model is realized based on PWM four primaries LED The method for enclosing luminous intensity distribution, comprises the following steps：

(1) each monochromatic light measurement and colorimetric performance parameter, are obtained using integrating sphere optical spectrum instrumentation；

(2), by each monochromatic light measurement and colorimetric performance parameter, corresponding each monochromatic tristimulus is calculated Value；

(3), according to luminous flux and dutycycle direct proportionality, the functional relation of luminous flux and dutycycle is derived；

(4) principle, is added according to color, the tristimulus values of the mixed light is equal to each monochromatic tristimulus values and is added, Each monochromatic ratio in three primary colours mixed light Mathematical Modeling and mixed light is finally given, colour mixture equation group is obtained；

(5) target color coordinates, the colour temperature of mixed light, are determined；

(6), white monochromatic color temperature value in the color temperature value and mixed light of contrast aim colour, derives chromaticity coordinate, and light leads to The functional relation of amount and dutycycle；

(7), determine the luminous flux of target colour temperature, calculate each dutycycle of RGBW, finally export, reach luminous intensity distribution purpose.

Monochromatic tristimulus values computational methods are in the step (2)：

The step (4) concretely comprises the following steps：D_ug、D_ug、D_ug、D_ugRepresent the dutycycle of RGBW four primaries, (x_m, y_m)、Y_mGeneration The chromaticity coordinates and luminous flux of table mixed light, (x_r, y_r)、(x_g, y_g)、(x_b, y_b)、(x_w, y_w) chromaticity coordinates of RGBW four primaries is represented, Y_r、Y_g、Y_b、Y_wRepresent the luminous flux of RGBW four primaries；K_mRepresent the colour temperature of mixed light, K_wRepresent the colour temperature of white light in four primary；

Work as K_m＞ K_wWhen, D_ur=0,

Work as K_m＜ K_wWhen, D_ub=0,

Step (4) the colour mixture equation group is calculated with below equation：

X_m=X_R+X_G+X_B+X_W；

Y_m=Y_R+Y_G+Y_B+Y_W；

Z_m=Z_R+Z_G+Z_B+Z_W；

Wherein A_r=Y_r/y_r、A_g=Y_g/y_g、A_b=Y_b/y_b、A_w=Y_w/y_w, X_m、Y_m、Z_mRepresent the tristimulus values of mixed light.

Step (3) luminous flux is with the functional relation of dutycycle：Y_m=D_urY_r+D_ugY_g+D_ubY_b+D_uwY_w；

Wherein, Y_r、Y_g、Y_b、Y_wY values under the full current works of respectively light source R, G, B, W, in CIE-1931 standards Colorimeter system moderate stimulation value Y is equal to luminous flux.

The dutycycle D_ug、D_ug、D_ug、D_ugD should be met_ug≤1、D_ug≤1、D_ug≤1、D_ug≤1。

The Y_mAs object function, need to meet：

Work as K_m＞ K_wWhen, D_ur=0,

Work as K_m＜ K_wWhen, D_ub=0,

Y_mWhen taking the maximum of above-mentioned equation, the output of mixed light highlight flux can be met.

More than the PWM frequency 1Khz.

The present invention has the following advantages and effect relative to prior art：

1st, the present invention is on the basis of simple R GB mixed lights, it is proposed that RGBW four primary light mixing methods, by four primary by CIE- 1931 color matching stepping figures are divided into tri- intervals of I, II, III, by the parameters such as specified target color coordinates, colour temperature, luminous flux, root According to CIE-1931 color matching stepping figures, it is zero to specify one of which light source output value, and building other three output valves has single solution Mathematical Modeling, derives each monochromatic functional value in RGBW four primaries.With product low cost, adjustable color temperature high precision, side The advantages of formula simplicity, comfortable illumination and good using effect.

Brief description of the drawings

Fig. 1 is the FB(flow block) of the method that full gamut scope luminous intensity distribution is realized based on PWM four primaries LED；

Fig. 2 is that the color LED of RGBW tetra- connect distribution map；

Fig. 3 is CIE-1931 color matching stepping figures.

Specific embodiment

For ease of it will be appreciated by those skilled in the art that below in conjunction with the accompanying drawings and embodiment the present invention is made it is further specifically It is bright.

Embodiment 1：

As shown in Figures 1 to 3, the method for realizing full gamut scope luminous intensity distribution based on PWM four primaries LED, comprises the following steps：

(1) each monochromatic light measurement and colorimetric performance parameter, are obtained using integrating sphere optical spectrum instrumentation；

(2), by each monochromatic light measurement and colorimetric performance parameter, corresponding each monochromatic tristimulus is calculated Value；

(3), according to luminous flux and dutycycle direct proportionality, the functional relation of luminous flux and dutycycle is derived；

(4) principle, is added according to color, the tristimulus values of the mixed light is equal to each monochromatic tristimulus values and is added, Each monochromatic ratio in three primary colours mixed light Mathematical Modeling and mixed light is finally given, colour mixture equation group is obtained；

(5) target color coordinates, the colour temperature of mixed light, are determined；

(6), white monochromatic color temperature value in the color temperature value and mixed light of contrast aim colour, derives chromaticity coordinate, and light leads to The functional relation of amount and dutycycle；

(7), determine the luminous flux of target colour temperature, calculate each dutycycle of RGBW, finally export, reach luminous intensity distribution purpose.

It is specifically：Desired luminous flux is Y_m, desired colour temperature is K_m, desired chromaticity coordinates is (x_m, y_m), use R, G, B, W four primary coordinate are respectively (x_r, y_r)、(x_g, y_g)、(x_b, y_b)、(x_w, y_w), the luminous flux of RGBW four primaries is Y_r、 Y_g、Y_b、Y_w, the colour temperature of white light is K in four primary_w。

As shown in figure 1, comprising the following steps that：

1st, RGBW light sources are selected, using 5 groups of RGB atmospheric electricity LED-2016 glory series of light sources, 5 full strings, W light sources use 12 This step to obtain 2835 color rendering white lights high series, connected mode be 3 strings 4 simultaneously.Specific distribution is referring to Fig. 2, as shown in Fig. 2 W is white light Source R, G, B are respectively red, green, blueness.Tri- light sources of RGB are one group, are symmetrically arranged amongst on light source board, 12 white light sources Be evenly distributed on light source board, reach red, green, blue, white light it is defeated when even light mixing target.Obtained using integrating sphere optical spectrum instrumentation Obtain each monochromatic light measurement and colorimetric performance parameter；

2nd, by each monochromatic light measurement and colorimetric performance parameter, corresponding each monochromatic tristimulus values is calculated；

Each monochromatic tristimulus values computing formula is：

3rd, according to luminous flux and dutycycle functional relation in direct ratio, the functional relation of luminous flux and dutycycle is derived Formula；

Change the PWM duty cycle for driving LED, its chromaticity coordinate does not change substantially, and the corresponding linear change of luminous flux Change, so for the convenience of call for Votes in engineering, being approximately considered luminous flux and dutycycle functional relation in direct ratio：

Y_m=D_urY_r+D_ugY_g+D_ubY_b+D_uwY_w……………………….(2)

Wherein, D_ug、D_ug、D_ug、D_ugRepresent the dutycycle of RGBW four primaries.

4th, principle is added according to color, the tristimulus values of the mixed light is equal to each monochromatic tristimulus values and is added, most Each monochromatic ratio in three primary colours mixed light Mathematical Modeling and mixed light is obtained eventually, obtains colour mixture equation group；

According to spectral distribution curve color addition principle：

X_m=X_R+X_G+X_B+X_W

Y_m=Y_R+Y_G+Y_B+Y_W

Z_m=Z_R+Z_G+Z_B+Z_W………………………(3)

Derive

Wherein, A_r=Y_r/y_r、A_g=Y_g/y_g、A_b=Y_b/y_b、A_w=Y_w/y_w, X_m、Y_m、Z_mRepresent the tristimulus values of mixed light.

5th, target color coordinates, the colour temperature of mixed light are determined；

6th, white monochromatic color temperature value in the color temperature value and mixed light of contrast aim colour, derives chromaticity coordinate, luminous flux With the functional relation of dutycycle.

According to RGBW four primaries in the coordinate value of CIE-1931 chromaticity analysis charts, I, II, III can be divided by chromaticity analysis chart Three intervals, as shown in figure 3, R, G, B represent red, green, the blue position on CIE x-y chromaticity diagrams respectively, line R, G, B constitute a mixed light triangle, and the color temperature value of aim colour M, line M point R points, M point G points, M points B are determined on colour temperature curve Point, tri- intervals of I, II, III are divided into by the triangle that RGB is constituted.

As target colour temperature K_m>K_wWhen, it is interval in I, set D_ur=0,

Then the dutycycle of four-way can convolution (2), (5) try to achieve：

As target colour temperature K_m<K_wWhen, it is interval in III, set D_ub=0,

Then the dutycycle of four-way can convolution (2), (5) try to achieve：

7th, determine the luminous flux of target colour temperature, calculate each dutycycle of RGBW.

In theory in chromaticity analysis chart, the span of luminous flux is [0, Y_r+Y_g+Y_b+Y_w], but use PWM to adjust Light time, luminous flux is constrained by dutycycle, it is impossible to the span on realization theory.In dimming process, different chromaticity coordinates Mixed light, the ratio of its RGBW four primary is different.Only dutycycle ratio is 1:1:1:1 mixed light its duty Bizet can be same When reach 100%, now the span of luminous flux be 0~Y_r+Y_g+Y_b+Y_w, the luminous flux span of other mixed lights is then Less than this scope, every group of chromaticity coordinate has corresponding highlight flux.From practical significance, the dutycycle of PWM should expire Sufficient D_ur≤ 1, D_ug≤ 1, D_ub≤ 1, D_uw≤ 1, Y_mAs object function, (6), (7) formula deform and can obtained

K_m＞ K_wWhen, D_ur=0

K_m＜ K_wWhen, D_ub=0

Meet after (8), the luminous flux of (9) formula, choose the maximum of Ym, bring formula (6), (7) formula into, calculate accounting for for RGBW Empty ratio.

Experiment rgb light source is atmospheric electricity LED-2016 glories series, and its dominant wavelength is respectively λ r=620nm, λ g=523nm, λ B=465nm.White light source steps to obtain 2935 color rendering white light series high using this.LED is measured with the PMS-80 spectral investigators in a distant place Chromatic value of each chip in full current work state in pearl.Result is as shown in the table：

It is then determined that the chromaticity coordinates M (0.4610,0.4110) of target light, K_m=2700K.Luminous flux Y_m=120LM, wherein Luminous flux Y_mMeet (9) formula, bring above-mentioned parameter into equation group (7) and draw D_ur=91%, D_ug=51%, D_ub=0, D_uw= 11%.

Above-mentioned dutycycle is assigned in RGBW light sources, the PMS-80 spectral investigators test in a target light distant place draws Y_m′ =119, M ' (0.4612,0.4116), K_m′=2688K.The measured value of chromaticity coordinate, luminous flux and colour temperature compares kiss with setting value Close, within 2.5%, the error of luminous flux is maintained within 4.5% the error of chromaticity coordinate.The luminous flux of LED is by junction temperature Influence is larger, so during light modulation, with the raising of power, the error of measured value and setting value also can be bigger.Its error all keeps In more rational scope, illustrating the functional relation of (6), the chromaticity coordinate described by (7) formula and dutycycle can instruct reality In light modulation toning.

Above-mentioned specific embodiment is the preferred embodiments of the present invention, can not be limited the invention, and others are appointed Change or other equivalent substitute modes that what is made without departing from technical scheme, are included in protection of the invention Within the scope of.

Claims (8)

1. the method for full gamut scope luminous intensity distribution being realized based on PWM four primaries LED, it is characterised in that comprise the following steps：

(1) each monochromatic light measurement and colorimetric performance parameter, are obtained using integrating sphere optical spectrum instrumentation；

(2), by each monochromatic light measurement and colorimetric performance parameter, corresponding each monochromatic tristimulus values is calculated；

(3), according to luminous flux and dutycycle direct proportionality, the functional relation of luminous flux and dutycycle is derived；

(4) principle, is added according to color, the tristimulus values of the mixed light is equal to each monochromatic tristimulus values and is added, finally Each monochromatic ratio in three primary colours mixed light Mathematical Modeling and mixed light is obtained, colour mixture equation group is obtained；

(5) target color coordinates, the colour temperature of mixed light, are determined；

(6), white monochromatic color temperature value in the color temperature value and mixed light of contrast aim colour, derives chromaticity coordinate, luminous flux with The functional relation of dutycycle；

(7), determine the luminous flux of target colour temperature, calculate each dutycycle of RGBW, finally export, reach luminous intensity distribution purpose.

2. the method that full gamut scope luminous intensity distribution is realized based on PWM four primaries LED according to claim 1, it is characterised in that Monochromatic tristimulus values computational methods are in the step (2)：

$X=\frac{Y}{y}x;$

$Y=\frac{Y}{y}y.$

3. the method that full gamut scope luminous intensity distribution is realized based on PWM four primaries LED according to claim 2, it is characterised in that The step (4) concretely comprises the following steps：D_ug、D_ug、D_ug、D_ugRepresent the dutycycle of RGBW four primaries, (x_m, y_m)、Y_mRepresent mixed light Chromaticity coordinates and luminous flux, (x_r, y_r)、(x_g, y_g)、(x_b, y_b)、(x_w, y_w) represent the chromaticity coordinates of RGBW four primaries, Y_r、Y_g、Y_b、 Y_wRepresent the luminous flux of RGBW four primaries；K_mRepresent the colour temperature of mixed light, K_wRepresent the colour temperature of white light in four primary；

Work as K_m＞ K_wWhen, D_ur=0,

$D_{ug}=\&lsqb;\frac{\left(y_b-y_w\right)\left(x_w-x_m\right)+\left(y_m-y_w\right)\left(x_b-x_w\right)}{\left(y_b-y_w\right)\left(x_w-x_g\right)+\left(y_g-y_w\right)\left(x_b-x_w\right)}\&rsqb;\frac{y_g{Y}_m}{{\mathrm{yY}}_g};$

$D_{ub}=\&lsqb;\frac{\left(y_g-y_w\right)\left(x_w-x_m\right)+\left(y_m-y_w\right)\left(x_g-x_w\right)}{\left(y_g-y_w\right)\left(x_w-x_b\right)+\left(y_b-y_w\right)\left(x_g-x_w\right)}\&rsqb;\frac{y_b{Y}_m}{{\mathrm{yY}}_b};$

$D_{uw}=\&lsqb;\frac{\left(y_g-y_b\right)\left(x_b-x\right)+\left(y_m-y_b\right)\left(x_g-x_b\right)}{\left(y_g-y_b\right)\left(x_b-x_w\right)+\left(y_w-y_b\right)\left(x_g-x_b\right)}\&rsqb;\frac{y_w{Y}_m}{{\mathrm{yY}}_w};$

Work as K_m＜ K_wWhen, D_ub=0,

$D_{ur}=\&lsqb;\frac{\left(y_g-y_w\right)\left(x_w-x_m\right)+\left(y_m-y_w\right)\left(x_g-x_w\right)}{\left(y_g-y_w\right)\left(x_w-x_r\right)+\left(y_r-y_w\right)\left(x_g-x_w\right)}\&rsqb;\frac{y_r{Y}_m}{{\mathrm{yY}}_r};$

$D_{ug}=\&lsqb;\frac{\left(y_w-y_r\right)\left(x_r-x_m\right)+\left(y_m-y_r\right)\left(x_w-x_r\right)}{\left(y_w-y_r\right)\left(x_r-x_g\right)+\left(y_g-y_r\right)\left(x_w-x_r\right)}\&rsqb;\frac{y_g{Y}_m}{{\mathrm{yY}}_g};$

$D_{uw}=\&lsqb;\frac{\left(y_g-y_r\right)\left(x_r-x_m\right)+\left(y_m-y_r\right)\left(x_g-x_r\right)}{\left(y_g-y_r\right)\left(x_r-x_w\right)+\left(y_w-y_r\right)\left(x_g-x_r\right)}\&rsqb;\frac{y_w{Y}_m}{{\mathrm{yY}}_w}.$

4. the method that full gamut scope luminous intensity distribution is realized based on PWM four primaries LED according to claim 3, it is characterised in that Step (4) the colour mixture equation group is calculated with below equation：

X_m=X_R+X_G+X_B+X_W；

Y_m=Y_R+Y_G+Y_B+Y_W；

Z_m=Z_R+Z_G+Z_B+Z_W；

$x_m=\frac{X_m}{X_m+Y_m+Z_m}=\frac{A_r{D}_{ur}{x}_r+A_g{D}_{ug}{x}_g+A_b{D}_{ub}{x}_b+A_w{D}_{uw}{x}_w}{A_r{D}_{ur}+A_g{D}_{ug}+A_b{D}_{ub}+A_w{D}_{uw}};$

$y_m=\frac{Y_m}{X_m+Y_m+Z_m}=\frac{A_r{D}_{ur}{y}_r+A_g{D}_{ug}{y}_g+A_b{D}_{ub}{y}_b+A_w{D}_{uw}{y}_w}{A_r{D}_{ur}+A_g{D}_{ug}+A_b{D}_{ub}+A_w{D}_{uw}};$

Wherein A_r=Y_r/y_r、A_g=Y_g/y_g、A_b=Y_b/y_b、A_w=Y_w/y_w, X_m、Y_m、Z_mRepresent the tristimulus values of mixed light.

5. the method that full gamut scope luminous intensity distribution is realized based on PWM four primaries LED according to claim 4, it is characterised in that Step (3) luminous flux is with the functional relation of dutycycle：

Y_m=D_urY_r+D_ugY_g+D_ubY_b+D_uwY_w；

Wherein, Y_r、Y_g、Y_b、Y_wY values under the full current works of respectively light source R, G, B, W, in CIE-1931 standard colorimetrics system System moderate stimulation value Y is equal to luminous flux.

6. the method that full gamut scope luminous intensity distribution is realized based on PWM four primaries LED according to claim 5, it is characterised in that： The dutycycle D_ug、D_ug、D_ug、D_ugD should be met_ug≤1、D_ug≤1、D_ug≤1、D_ug≤1。

7. the method that full gamut scope luminous intensity distribution is realized based on PWM four primaries LED according to claim 6, it is characterised in that The Y_mAs object function, need to meet：

Work as K_m＞ K_wWhen, D_ur=0,

$Y_m\&le;\&lsqb;\frac{\left(y_b-y_w\right)\left(x_w-x_g\right)+\left(y_g-y_w\right)\left(x_b-x_w\right)}{\left(y_b-y_w\right)\left(x_w-x_m\right)+\left(y_m-y_w\right)\left(x_b-x_w\right)}\&rsqb;\frac{{\mathrm{yY}}_g}{y_g};$

$Y_m\&le;\&lsqb;\frac{\left(y_g-y_w\right)\left(x_w-x_b\right)+\left(y_b-y_w\right)\left(x_g-x_w\right)}{\left(y_g-y_w\right)\left(x_w-x_m\right)+\left(y_m-y_w\right)\left(x_g-x_w\right)}\&rsqb;\frac{{\mathrm{yY}}_b}{y_b};$

$Y_m\&le;\&lsqb;\frac{\left(y_g-y_b\right)\left(x_b-x_w\right)+\left(y_w-y_b\right)\left(x_g-x_b\right)}{\left(y_g-y_b\right)\left(x_b-x\right)+\left(y_m-y_b\right)\left(x_g-x_b\right)}\&rsqb;\frac{{\mathrm{yY}}_w}{y_w};$

Work as K_m＜ K_wWhen, D_ub=0,

$Y_m\&le;\&lsqb;\frac{\left(y_g-y_w\right)\left(x_w-x_r\right)+\left(y_r-y_w\right)\left(x_g-x_w\right)}{\left(y_g-y_w\right)\left(x_w-x_m\right)+\left(y_m-y_w\right)\left(x_g-x_w\right)}\&rsqb;\frac{{\mathrm{yY}}_r}{y_r};$

$Y_m\&le;\&lsqb;\frac{\left(y_w-y_r\right)\left(x_r-x_g\right)+\left(y_g-y_r\right)\left(x_w-x_r\right)}{\left(y_w-y_r\right)\left(x_r-x_m\right)+\left(y_m-y_r\right)\left(x_w-x_r\right)}\&rsqb;\frac{{\mathrm{yY}}_g}{y_g};$

$Y_m\&le;\&lsqb;\frac{\left(y_g-y_r\right)\left(x_r-x_w\right)+\left(y_w-y_r\right)\left(x_g-x_r\right)}{\left(y_g-y_r\right)\left(x_r-x_m\right)+\left(y_m-y_r\right)\left(x_g-x_r\right)}\&rsqb;\frac{{\mathrm{yY}}_w}{y_w};$

Y_mWhen taking the maximum of above-mentioned equation, the output of mixed light highlight flux can be met.

8. the method that full gamut scope luminous intensity distribution is realized based on PWM four primaries LED according to claim 6, it is characterised in that： More than the PWM frequency 1Khz.