CN104093247B - A kind of full gamut multichannel color mixing method - Google Patents

Abstract

The invention belongs to the technical field of semiconductor lighting, in particular to a full-color gamut multi-channel color mixing method. The present invention utilizes four parameter vectors (<i>Z _i </i>,?<i>K _1j </i>,?<i>K _2k </i> _, <i>K _3l </i>) to control N groups (N≥5) of single-color LED packaged devices with different dominant wavelengths are mixed for color. Each group of LED devices is composed of at least one LED chip or module, and the dominant wavelength is distributed between 380 and 780? nm wavelength range. When it is necessary to display the light color corresponding to a certain color coordinate, the reproducible N-gon color gamut of the LED device is divided into N? >Z _i </i>, by adjusting the luminous flux ratio of the LED device corresponding to the apex of the triangle <i>K _1j </i>,? <i>K _2k </i> _, <i>K _3l </i>, mix the light to get the desired target light color. The invention greatly increases the reproducible color gamut area, realizes more colorful color display, and opens up more possibilities for scene lighting design; while ensuring the reproduction of a wide range of color gamut, the invention can also Reduce the amount of data transfers on the console.

Description

A full color gamut multi-channel color mixing method

technical field

The invention belongs to the technical field of semiconductor lighting, and in particular relates to a full-color gamut multi-channel color mixing method.

Background technique

LED color mixing technology is widely used in general lighting, scene lighting, stage decoration and other occasions. The principle is to select the monochromatic light emitted by LEDs with different main wavelengths as the primary color, and mix these primary colors in an appropriate proportion to produce a new one. Light color of predetermined color. In the chromaticity diagram, connect the color coordinates of the light colors of multiple LEDs for color mixing to form a polygon. The color gamut contained in this polygon limits the range of light colors that these LEDs can obtain by mixing light.

Common color mixing technology is limited to RGB three-primary color mixing, generally using red LEDs with a dominant wavelength of 610−640 nm, green LEDs with a dominant wavelength of 510−540 nm, and blue LEDs with a dominant wavelength of 450−480 nm. The disadvantage of this is that: the area of the color gamut surrounded by the color coordinates of the base color is not large enough to reproduce most of the light colors in the color gamut, and can only reproduce about 30% of the full color gamut; Light color has a large deviation.

Patent US7113152 proposes a device, system and method for electronic true-color display, using at least four primary colors to mix colors and using a controller to control the light paths of the four primary colors to generate a light image of a color image. Patent CN202796949 proposes a five-color mixed LED lamp, using red, green, blue, yellow, white, five colors for color mixing, its color gamut area may be improved compared with traditional methods, but the above patent does not involve color mixing control technology, and the five-channel control makes the communication volume too large, which is difficult to realize at the technical level. Patent EP1878318 proposes a method of mixing colors using N primary colors (N≥4) to obtain white light with different color temperatures. The N primary colors include a white light located near the black body line and multiple pure color lights near the edge of the chromaticity diagram. The target The position of the color coordinates is within the triangle surrounded by the color coordinates of the above-mentioned white light and the color coordinates of two pure colors closest to the target light color, so adjusting the color lights of the above three color coordinates can mix colors to produce the target light color. However, this method is limited to producing white light with different color temperatures, and the primary color of white light used for color mixing is likely to cause color drift, which will cause the color mixing result to fail to achieve the expected effect.

Since the existing technology is difficult to meet people's increasingly stringent requirements for lighting in practical applications, it is necessary to develop a more complete, more precise, and easier-to-control color mixing technology.

Contents of the invention

The purpose of the present invention is to provide a full color gamut multi-channel color mixing method.

The present invention uses N kinds of monochromatic light LEDs for color mixing and light mixing. When N≥7, it can reproduce more than 90% of the color gamut of the CIE 1931 chromaticity diagram, showing more than 48 million colors. The color coordinates of the synthetic light of the present invention are close to the light color of nature, which can promote the development of healthy lighting and ecological lighting industry technology, and can be widely used in many lighting fields such as LED commercial lighting, home lighting, outdoor landscape lighting, etc., and will greatly improve the development of LED lighting technology. Play a very important role in technology support.

A full-color gamut multi-channel color mixing method proposed by the present invention adopts LED packaging devices with different main wavelengths including N groups (N≥5, generally 8≥N≥5) and a multi-channel intelligent control system. Four parameter vectors are used to select the required LED drive control channel and give the drive current, so that the synthesized light can reproduce all colors in the N-gon color gamut with N groups of LED color coordinates as vertices.

The N groups of LED packaging devices used in the present invention have different dominant wavelengths, and the dominant wavelengths are distributed in the wavelength range of 380−780 nm; each group of LEDs is composed of at least one LED chip or module, and each group of LEDs is equipped with Corresponding 1 drive control channel in the control system.

When it is necessary to display the light color corresponding to a certain color coordinate, the present invention adopts a partition synthesis method to divide the color gamut covered by N-color LEDs into N−2 areas to control color mixing, thereby reducing the amount of transmitted data. Since the color light at the vertex of the color gamut triangle can reproduce all the color coordinates inside the triangle, a point P _f can be selected from the color coordinate points of N groups of LEDs, which is called a "fixed point", and two points can be selected in turn from other points. Adjacent points and P _f form a triangle, which is called "partition triangle", so that the N-gon color gamut is divided into N−2 triangular areas. The target light color to be reproduced can be represented by a four-parameter light color vector ( Z _i , K _1j , K _{2k ,} K _3l ), where Z _i is the area code, i = 0, 1, ... N−2, respectively Corresponding to N−2 triangular color gamuts, that is, Z _i determines the partition triangle where the color coordinates of the target light color are located; K _1j , K _{2k ,} K _3l = [0, 1] respectively represent the 3 The luminous flux ratio of a group of LEDs when the light is mixed to obtain the target light color. The light color vector ( Z _i , K _1j , K _{2k ,} K _3l ) can be mapped to the LED current vector ( Z _i , I _1j , I _2k , I _3l ), where I _1j , I _2k , I _3l are the vertices of the color gamut Corresponding to the driving currents of the three groups of LED packaged devices, the control system can select the corresponding three driving control channels through _Zi .

For a given target light color P _c ( x , y ), calculate the slope between P _c and P _f , and determine the code Z _i of the triangular area where the target light color P _c is located according to the slope, then P _c can correspond to 3 sets of LED mixed light. According to the light color calculation method, the mixed luminous flux ratio K _1j : K _2k : K _3l of the three groups of LEDs is obtained, and converted into the corresponding LED driving current I _1j , I _2k , I _3l , and the LED driving current vector ( Z _i , I _1j , I _2k , I _3l ). Select the corresponding 3 drive control channels and output the corresponding drive current. The 3 groups of LEDs will emit the corresponding color light under the drive of the current, and the target light color can be obtained after mixing.

Compared with the existing color mixing technology, the present invention has the following advantages:

The present invention uses N groups (N≥5) of monochromatic LEDs with different main wavelengths to mix light, which greatly increases the reproducible color gamut area. When N≥7, it can reproduce more than 90% of the CIE 1931 chromaticity diagram The color gamut realizes more colorful color display and opens up more possibilities for scene lighting design.

The present invention adopts the method of color gamut partition synthesis, utilizes the real-time dynamic control algorithm of color coordinates, decomposes the N-gon color gamut formed by the color coordinates of N-color LEDs into N−2 triangles, and controls the current of the LED packaging device with a four-parameter vector, While ensuring the ability to reproduce a wide range of color gamut, it also reduces the amount of data transmission at the control end.

Description of drawings

FIG. 1 is an example of a color gamut map that can be reproduced by the full-color-gamut multi-channel color mixing method of the present invention.

FIG. 2 is a schematic color mixing diagram of the full-color gamut multi-channel color mixing method of the present invention.

FIG. 3 is a flow chart of reproducing a certain target light color by the full-color gamut multi-channel color mixing method of the present invention.

Labels in the figure: P _f , P ₀ −P ₅ —color coordinates of 7 groups of LED packaging devices; L ₁ −L ₅ —5 partitioned triangles.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings and embodiments. The described embodiments are only some of the embodiments of the invention. All other embodiments without creative achievements based on the embodiments of the present invention belong to the protection scope of the present invention.

Referring to Fig. 1, an embodiment of the full-color gamut multi-channel color mixing method of the present invention includes: 7 groups of LED packaging devices with different dominant wavelengths, corresponding to the color coordinate points _Pf and P of 7 different positions on the chromaticity diagram ₁ −P ₆ , then all the colors in the heptagonal color gamut formed by the 7 points can be obtained by color mixing of these 7 groups of LED devices. Much larger, can reach more than 90% of the chromaticity diagram. Take one of the color coordinate points P _f as a fixed point, and take adjacent points from the other six points P ₀ −P ₅ to form a triangle with P _f . In total, the heptagonal color gamut can be divided into 5 partitioned triangular color gamuts L ₁ −L ₅ .

Referring to Fig. 2, the color coordinate point of any light color in the heptagonal color gamut of the present invention can be represented by a four-parameter vector ( Z _i , K _1j , K _{2k ,} K _3l ), wherein Z _i is the area code, i = 0−4 respectively correspond to 5 divisional triangles; K _1j , K _{2k ,} K _3l = [0, 1] respectively represent the luminous flux ratios of the 3 groups of LEDs corresponding to the divisional triangle when mixing colors to obtain the target light color. Since the luminous flux of an LED device is related to its driving current, the light color vector ( Z _i , K _1j , K _{2k ,} K _3l ) can be mapped to the LED current vector ( Z _i , I _1j , I _2k , I _3l ), where I _1j , I _2k , and I _3l are the driving currents of the three groups of LED packaging devices corresponding to the triangular vertices of the partition, and the corresponding three driving control channels can be selected and output through _Zi .

Referring to Fig. 3, when displaying a certain target light color, according to the position of its color coordinate P _c ( x , y ), the partition triangle where the target light color is located can be determined through the addressing of the control system, and then the apex of the color gamut of the triangle is driven and controlled The driving current of the corresponding LED device can adjust the luminous flux emitted by the three groups of LEDs, and the desired target light color can be obtained after the light is mixed.

The color coordinates P _f ( x _f , y _f ), P ₀ ( x ₀ , y ₀ ), P ₁ ( x ₁ , y ₁ ), P ₂ ( x ₂ , y ₂ ), P ₃ ( x ₃ , y ₃ ), P ₄ ( x ₄ , y ₄ ), P ₅ ( x ₅ , y ₅ ), you can get the slopes of the two sides of the five partitioned triangles with P _f as the vertex:

The slope of P _f P ₀ is k ₀ =( y ₀ − y _f )/( x ₀ − x _f ),

The slope of P _f P ₁ is k ₁ =( y ₁ − y _f )/( x ₁ − x _f ),

The slope of P _f P ₂ is k ₂ =( y ₂ − y _f )/( x ₂ − x _f ),

The slope of P _f P ₃ is k ₃ =( y ₃ − y _f )/( x ₃ − x _f ),

The slope of P _f P ₄ is k ₄ =( y ₄ − y _f )/( x ₄ − x _f ),

The slope of P _f P ₅ is k ₅ =( y ₅ − y _f )/( x ₅ − x _f ).

According to the slope k of the line P _f P _c connecting the target light color P _c and the fixed point P _f =( y − y _f )/( x − x _f ), it can be determined that k _{i +1} < k < k _i ( i = 0 −4), so that the partition triangle code Z _i where the target light color is located can be determined, that is, three sets of LED color coordinate points P _i , P _{i +1} and P _f for color mixing can be determined. Then the ratio of luminous flux mixed by these 3 groups of LEDs is:

,

Thus, the corresponding LED drive current vector can be obtained.

The color mixing method of the present invention mainly aims at increasing the reproduced color gamut, and uses 7 groups of LED devices with different dominant wavelengths for color mixing, and the dominant wavelengths of each group of LEDs are distributed within the wavelength range of 380−780 nm. The color mixing method can reproduce more than 90% of the color gamut of the CIE 1931 chromaticity diagram, greatly improving the richness of colors, and providing more creative solutions for scene lighting design.

In order to simplify the control parameters, the color mixing method of the present invention adopts a real-time dynamic control algorithm of color coordinates and uses one four-parameter vector to control the driving of 7 groups of LED devices, which effectively reduces the amount of data transmission at the control end, thereby speeding up the communication speed and reducing the control. cost.

Claims (1)

1. a full gamut multichannel color mixing method, it is characterized in that concrete steps are: adopt the LED packaging and 1 the multi-channel intelligent control system that comprise N and organize different dominant wavelengths, utilize four parameter vectors to select required LED drive control channel and provide drive current, make the now all colours in the shape and color territory, N limit on summit taking N group LED chromaticity coordinates of synthetic recovery; N >=5; Wherein:

The different dominant wavelength of described N group LED packaging is distributed in 380 780nm wave-length coverages;

Described LED packaging is made up of at least 1 LED chip or module, and every group of LED is equipped with respectively 1 and drives control channel to control;

Need to show corresponding photochromic of certain chromaticity coordinates time, in described summit, choose a some P_fAs fixing point, from other points, choose successively two consecutive points and P_fForm a triangle, be referred to as " subregion triangle ", thereby shape and color territory, N limit is divided into 2 delta-shaped regions of N;

1 four parameter vector of photochromic employing to any point in described shape and color territory, N limit (Z _i ,K _1j ,K _2k, K _3l ) represent, whereinZ _i For area code,i=0,1 ... N 2, corresponds respectively to described 2 delta-shaped regions of N,K _1j ,K _2k, K _3l =[0,1] represents that respectively 3 groups of LED corresponding to this colour triangle obtain the logical ratio of the light of target when photochromic at mixed light;

Described photochromic vector (Z _i ,K _1j ,K _2k, K _3l ) be mapped to LED current vector (Z _i ,I _1j ,I _2k ,I _3l ), whereinI _1j ,I _2k ,I _3l For the drive current of 3 groups of LED packagings corresponding to the photochromic place of described target subregion triangle colour gamut, described control system is passed throughZ _i Choose 3 corresponding driving control channels.