阅读说明：本技术 N（n≥20）基色光谱拟合目标光谱的优化方法 (Optimization method for fitting target spectrum by N (N is more than or equal to 20) primary color spectrum ) 是由 韩秋漪 柳丝婉 李福生 张善端 于 2020-06-02 设计创作，主要内容包括：本发明公开了一种<I>N</I>(<I>N</I>≥20)基色光谱拟合目标光谱的优化方法。本发明针对各列基色光谱相互影响的问题,利用半宽准确统计出每列光谱影响的其他基色光谱范围,在调节某列光谱时,同时协同调节峰值波长位于该列光谱半宽范围内的其他光谱,从而在提高准确率的同时最大程度地减少计算量,缩短了拟合时间,并提高了拟合精度,合成光谱满足一般显色指数Ra≥95,特殊显色指数R1~R15≥95,色温偏差ΔTc≤10 K的要求。(The invention discloses a N （ N Not less than 20) primary color spectrum fitting target spectrum. Aiming at the problem that the primary color spectrums of each row influence each other, the invention accurately counts the spectrum range of other primary colors influenced by each row of spectrums by utilizing the half-width, and simultaneously and cooperatively adjusts other spectrums with the peak wavelength positioned in the half-width range of the row of spectrums when adjusting a certain row of spectrums, thereby improving the accuracy, reducing the calculated amount to the maximum extent, shortening the fitting time, and improving the fitting precision, wherein the synthesized spectrum meets the requirements that the general color rendering index Ra is more than or equal to 95, the special color rendering indexes R1-R15 are more than or equal to 95, and the color temperature deviation delta Tc is less than or equal to 10K.)

1. An optimization method for fitting a target spectrum by an N-primary color spectrum is disclosed, wherein N is more than or equal to 20, and the method is characterized in that a synthesized spectrum meets the requirements that the general color rendering index Ra is more than or equal to 95, the special color rendering indexes R1-R15 are more than or equal to 95, and the color temperature deviation delta Tc is less than or equal to 10K;

in the process of fitting the target spectrum by using N primary color spectrums, the ith column is sequentially calculated, i is 1: N, the difference value D between the spectrum and the target spectrum_i；

If D of the spectrum in column i_iIf the standard does not meet the requirement of the criterion value, the peak wavelength of the ith spectrum is taken as the center, and the statistical peak wavelength is positioned in the half-width ranges [ lambda ] at the left side and the right side of the center spectrum_i-Δλ_i，λ_i+Δλ_i]And are respectively expressed as j ═ i-a, i-a +1, …, i-1, i +1, i +2, …, i + b; wherein λ is_iIs the peak wavelength, Δ λ_iIs half-width, and a is the peak wavelength in the range less than λ_iB is the peak wavelength in the range greater than lambda_iThe number of primary color spectra of (a);

sequentially calculating D of jth column spectrum and target spectrum_iAnd the synthesis proportion of the corresponding spectrum is adjusted according to the criterion so as to change the synthesized spectrum until the difference value D between the ith spectrum and the target spectrum_iWhen the requirements of the criterion are met, the adjustment of the ith row of spectrum is finished, and the adjustment of the next row of spectrum is carried out;

And when the N columns of spectra are used as the central spectrum, repeating the process to obtain a synthesized spectrum most approximate to the target spectrum.

2. The optimization method according to claim 1, comprising the following steps:

1) the spectral power distribution T (λ) and the fitted wavelength range [ λ ] of the target spectrum are known_L,λ_H]And N columns of primary color spectraNumber includes spectral power distribution M_i(lambda), peak wavelength lambda_iHalf width Δ λ_i(ii) a Giving an initial value p to the synthesis ratio of all primary color spectra_i＝p，0<p<1, the initial synthesized spectrum is

2) Setting a criterion value as a difference sum D_iThe criterion condition of (1);

3) setting a value zeta as an adjustment quantity of the primary color spectrum synthesis proportion;

4) calculating the difference value D between the synthesized spectrum and the target spectrum in the wavelength range corresponding to each row of primary color spectrum_i: for the ith column of primary color spectrum, take l_i＝Max(λ_i-λ_i-1,λ_i+1-λ_i) I.e. l_iThe larger value of the interval between the peak wavelengths of the ith row of quantum dot spectrums and the adjacent two rows of quantum dot spectrums; the sum of the difference values corresponding to the ith column of quantum dot spectrums

5) For the ith column primary spectrum, if | D_i|<Then the spectral ratio adjustment is completed and the corresponding synthesis ratio p is output_iAnd skipping to the next column of adjustment of the primary color spectrum; otherwise, the synthesis proportion of the row of primary color spectrums and other primary color spectrums within the influence range of the primary color spectrums is adjusted cooperatively;

6) The statistical peak wavelength is positioned in the half-width wavelength range [ lambda ] of the ith row of primary color spectrum_i-Δλ_i,λ_i+Δλ_i]In which a is the peak wavelength in the range less than lambda, and all primary color spectral sequences i-a, i-a +1, …, i-1 and i +1, i +2, …, i + b_iB is the peak wavelength in the range greater than lambda_iThe number of primary color spectra of (a);

7) let k be i-a, i-a +1, …, i-1, i, i +1, i +2, …, i + b, if | D_k|<Then, the ratio p is corresponded to_k′＝p_k(ii) a If | D_kIf | ≧ D_k>At 0 time p_k′＝p_k-ζ，D_k<At 0 time p_k′＝p_k+ ζ; obtaining an adjusted synthetic spectrum S' (lambda); returning to the step 4);

8) completing the adjustment of all the N rows of primary color spectrums according to the steps 4) -7), obtaining a synthetic spectrum result of the cycle, and calculating color rendering indexes Ra and R1-R15 and color and temperature parameters;

9) if the color parameters such as color rendering, color temperature and the like cannot simultaneously meet Ra is not less than 95, R1-R15 are not less than 95, and delta Tc is not more than 10K, reducing, and repeating the steps 2) -8) until all the color parameters meet the requirements, thereby obtaining the final synthesized spectrum.

3. The optimization method as claimed in claim 1, wherein the peak wavelengths of the N rows of primary color spectra cover a range of 380-780 nm, and the peak wavelengths are different.

4. The optimization method as claimed in claim 1, wherein the target spectrum covers all the color temperatures 2700-.

5. The optimization method according to claim 1, wherein the fitting process starts from any one of the N rows of primary color spectra, or is adjusted from the middle wavelength to both sides, or is adjusted from the short wavelength side to the long wavelength side, or from the long wavelength side to the short wavelength side in sequence.

Technical Field

The invention relates to the technical field of illumination, in particular to an optimization method for fitting an N (N is more than or equal to 20) primary color spectrum to a target spectrum.

Background

In recent years, the development of quantum dot fluorescent nano materials has attracted extensive attention. The quantum dot material is made of a semiconductor material synthesized by elements such as zinc, selenium, cadmium, sulfur and the like, has the diameter of 2-10 nm, and has an obvious quantum confinement effect. It can confine the carriers in a semiconductor in a very tiny space, and the carriers are excited to transition to a high energy level under illumination or electrical stimulation, and then return to the original energy level again and emit visible light of a fixed wavelength. Compared with the traditional fluorescent powder, the quantum dot fluorescent material has the advantages that the central wavelength and the half-width of the excitation spectrum can be adjusted according to the chemical composition and the particle diameter of the quantum dot material, so that the quantum dot material with different parameters can cover the whole visible spectrum and partial infrared spectrum.

The quantum dot fluorescent material provides more primary color spectrums capable of being used for spectrum synthesis, and provides basic conditions for black body spectrum fitting, solar simulator preparation and the like. Currently, most quantum dot-based light sources use ultraviolet LEDs to excite quantum dot fluorescent materials of different sizes to emit various monochromatic lights so as to obtain a white light spectrum by mixing. Because the emission spectrum of the quantum dots can theoretically cover the whole visible spectrum and part of the infrared spectrum, and the half width of the emission spectrum can be modulated by continuously changing the size of the quantum dots, under the condition of reasonably selecting the material and the size of the quantum dots, the light source based on the quantum dot LED can obtain a very continuous synthetic spectrum, and is an ideal light source for synthesizing a solar spectrum or a black body radiation spectrum.

Chinese patent CN106764691 proposes a solar spectrum and black body radiation spectrum simulation system based on quantum dot LED, which adopts K (K is greater than or equal to 20) monochromatic quantum dot LED light sources or ultraviolet LED light sources with different peak wavelengths, converges monochromatic light to a light mixer at the common focus of a focusing lens through a focusing lens, and finally exits through a light distribution lens set, the degree of fitting is high, but it is not proposed how to adjust the equivalent quantum dot spectrum to more than 20 columns to make the synthesized spectrum close to the target spectrum, so as to achieve a higher fitting coefficient, and no specific operable and realizable automatic adjustment algorithm is given; chinese patent CN109029728 proposes a new evaluation method of synthesized spectrum, which calculates the color tolerance of the synthesized spectrum according to the central color coordinate of the synthesized spectrum and the central color coordinate of the standard spectrum, but the evaluation of the fitting quality by using the color tolerance is from the perspective of the color parameters, some surfaces are single, and the fitting coefficient of the synthesized spectrum and other color parameters such as color rendering index and color temperature are not given at the same time, which is not comprehensive enough; chinese patent CN108051084 proposes a method for determining a spectrum peak center, which calculates the spectrum peak center, judges whether the iteration number is more than 1, and further judges whether the center is converged, thereby changing the center of a data range and outputting the peak center.

The spectrum adjusting range can be enriched by a large number of primary color spectrums, and fitting of a target spectrum is facilitated; however, there is no reliable method or scheme for how to adjust the number of spectra, such as N ≧ 20, to obtain the target spectrum quickly and accurately. The existing calculation methods are very tedious and long, and even the calculation process is not converged, so that the final result cannot be obtained, and therefore a more reliable fitting method is needed.

Disclosure of Invention

The invention aims to provide an optimization method for fitting an N (N is more than or equal to 20) primary color spectrum to a target spectrum. When the method is used for adjusting a certain primary color spectrum, other primary color spectrums influenced by the spectrum are considered in a unified mode, the spectrum range of other primary colors influenced by each line of spectrum is accurately counted by utilizing the half-width, and other spectrums with peak wavelengths within the half-width range of the line of spectrum are adjusted in a coordinated mode, so that the accuracy is improved, the calculated amount is reduced to the maximum extent, the fitting time is shortened, the fitting precision is improved, and the synthetic spectrum with excellent light color parameters and high fitting degree is obtained.

The technical scheme of the invention is specifically introduced as follows.

The invention provides an optimization method for fitting a target spectrum by an N (N is more than or equal to 20) primary color spectrum, wherein a synthesized spectrum meets the requirements that the general color rendering index Ra is more than or equal to 95, the special color rendering indexes R1-R15 are more than or equal to 95, and the color temperature deviation delta Tc is less than or equal to 10K;

In the process of fitting the target spectrum by using N primary color spectrums, the ith column is sequentially calculated, i is 1: N, the difference value D between the spectrum and the target spectrum_i；

If D of the spectrum in column i_iIf the standard value requirement is not met, the peak of the ith column spectrum is usedThe value wavelength is taken as the center, and the statistical peak wavelength is positioned in the half-width ranges [ lambda ] at the left and right sides of the central spectrum_i-Δλ_i，λ_i+Δλ_i]And are respectively expressed as j ═ i-a, i-a +1, …, i-1, i +1, i +2, …, i + b; wherein λ is_iIs the peak wavelength, Δ λ_iHalf width, a is the peak wavelength less than λ in this range_iB is the peak wavelength in the range greater than lambda_iThe number of primary color spectra of (a);

sequentially calculating D of jth column spectrum and target spectrum_iAnd the synthesis proportion of the corresponding spectrum is adjusted according to the criterion so as to change the synthesized spectrum until the difference value D between the ith spectrum and the target spectrum_iWhen the requirements of the criterion are met, the adjustment of the ith row of spectrum is finished, and the adjustment of the next row of spectrum is carried out;

and when the N columns of spectra are used as the central spectrum, repeating the process to obtain a synthesized spectrum most approximate to the target spectrum.

The optimization method for fitting the N (N is more than or equal to 20) primary color spectrum to the target spectrum comprises the following specific steps:

1) the spectral power distribution T (λ) and the fitted wavelength range [ λ ] of the target spectrum are known _L,λ_H]And the parameters of the N (N ≧ 20) columns of primary color spectra include spectral power distribution M_i(lambda), peak wavelength lambda_iHalf width Δ λ_i(ii) a Giving an initial value p to the synthesis ratio of all primary color spectra_i＝p(0<p<1) Then the initial synthesized spectrum is

2) Setting a sufficiently small value as the difference sum D_iThe criterion condition of (1);

3) setting a value zeta as an adjustment quantity of the primary color spectrum synthesis proportion;

4) calculating the difference sum of the synthesized spectrum and the target spectrum in the wavelength range corresponding to each column of primary color spectrum: for the ith column of primary color spectrum, take l_i＝Max(λ_i-λ_i-1,λ_i+1-λ_i) I.e. l_iIs the spectrum of the ith column of quantum dots and the spectra of two adjacent quantum dotsA larger value of the peak wavelength interval; the sum of the difference values corresponding to the ith column of quantum dot spectrumsWherein λ_min＝Max[λ_L,(λ_i-l_i/2)]，λ_max＝M in[(λ_i+l_i/2),λ_H]；

5) For the ith column of primary color spectrum, if | D_i|<Then the spectral ratio adjustment is completed and the corresponding synthesis ratio p is output_iAnd skipping to the next column of adjustment of the primary color spectrum; otherwise, the synthesis proportion of the row of primary color spectrums and other primary color spectrums within the influence range of the primary color spectrums is adjusted cooperatively;

6) the statistical peak wavelength is positioned in the half-width wavelength range [ lambda ] of the ith row of primary color spectrum_i-Δλ_i,λ_i+Δλ_i]In which a is the peak wavelength in the range less than lambda, and all primary color spectral sequences i-a, i-a +1, …, i-1 and i +1, i +2, …, i + b _iB is the peak wavelength in the range greater than lambda_iThe number of primary color spectra of (a);

7) let k be i-a, i-a +1, …, i-1, i, i +1, i +2, …, i + b, if | D_k|<If so, the corresponding proportion pk' ═ pk; if | D_kIf | ≧ D_k>At 0 time p_k′＝p_k-ζ，D_k<At 0 time p_k′＝p_k+ ζ; obtaining an adjusted synthetic spectrum S' (lambda); returning to the step 4);

8) completing the adjustment of all the N rows of primary color spectrums according to the steps 4) -7), obtaining a synthetic spectrum result of the cycle, and calculating light color parameters such as color rendering indexes Ra and R1-R15, color temperature and the like;

9) if the color rendering property, color temperature and other light color parameters can not simultaneously meet Ra being more than or equal to 95, R1-R15 being more than or equal to 95, and Delta Tc being less than or equal to 10K, the steps 2) -8) can be repeated on the basis until all the light color parameters meet the requirements, and the final synthesized spectrum is obtained.

In the invention, the peak wavelengths of the N rows of primary color spectrums cover the range of 380-780 nm, and the peak wavelengths are different.

In the invention, the target spectrum covers all the commonly used color temperature 2700-.

In the invention, the fitting process can start from any column in the N columns of primary color spectrums, can be adjusted from the middle wavelength to two sides, and also can be adjusted from the short wave end to the long wave end or from the long wave end to the short wave end in sequence.

Compared with the prior art, the invention has the following advantages:

for the primary color spectrums with a large number (N is more than or equal to 20), the difficulty is high if the primary color spectrums are adjusted simultaneously, and because the spectrums have a large number, the calculation is complicated and the screening time is long; if the adjustment is performed in a row and a column, the accuracy is low, and the spectrum of other primary colors that have been adjusted in the early stage is easily affected, and the problem that the calculation result cannot be converged may occur. Aiming at the problem of mutual influence of primary color spectrums of each row, the invention accurately counts other primary color spectrum ranges influenced by each row of spectrums by using the half-width as a balance factor, and simultaneously and cooperatively adjusts other spectrums with peak wavelengths positioned in the half-width range of the row of spectrums when adjusting a certain row of spectrums, thereby improving the accuracy rate, reducing the calculated amount to the maximum extent, shortening the fitting time, and improving the fitting precision to obtain the synthetic spectrum with superior light color parameters and high fitting degree. The method for fitting the target spectrum is suitable for visible light spectrum, ultraviolet spectrum and infrared spectrum, and the wavelength range of the method can be 200-1200 nm.

Drawings

FIG. 1 is a flow chart of the calculation of the fitting of the N (N ≧ 20) primary color spectrum to the target spectrum.

Fig. 2 is a normalized spectral power distribution of spectra of 21 primary color quantum dots according to an embodiment of the present invention.

FIG. 3 is a composite spectrum of a 21-color quantum dot spectrum of the present invention reproducing a 4000K blackbody spectrum.

Fig. 4 is a composite spectrum of a 21-color quantum dot spectrum of the present invention reproducing a 2700K blackbody spectrum.

Fig. 5 is a synthesized spectrum of a 21-color quantum dot spectrum of the present invention reproducing a 3000K blackbody spectrum.

Fig. 6 is a synthesized spectrum of a 21-color quantum dot spectrum of the present invention reproducing a 3500K blackbody spectrum.

Fig. 7 is a synthesized spectrum of a 21-color quantum dot spectrum of the present invention reproducing a 4500K blackbody spectrum.

Fig. 8 is a synthesized spectrum of a 21-color quantum dot spectrum of the present invention reproducing a 5000K blackbody spectrum.

FIG. 9 is a synthetic spectrum of a 21-color quantum dot spectrum reproduction 5500K recombined sunlight of the present invention.

FIG. 10 is a composite spectrum of 21-color quantum dot spectrum replication of 6000K recombination daylight of the present invention.

FIG. 11 is a synthesized spectrum of a 21-color quantum dot spectrum reproduction 6500K recombination daylight of the present invention.

Detailed Description

The optimization method for fitting the N (N ≧ 20) primary color spectrum to the target spectrum according to the present invention is further described in detail with reference to the accompanying drawings, which are only some embodiments of the present invention, and all other embodiments based on the embodiments of the present invention without inventive efforts shall fall within the scope of the present invention.