Method for generating sun-like white light through LED mixing and LED lamp set

Abstract

The invention relates to the field of LED healthy lighting, and discloses a method for generating sun-like white light through LED mixing and an LED lamp set. Comprising the steps that the color point of each LED lamp bead is determined around a black-body radiation ray, and each LED lamp bead is independently packaged and comprises an LED chip with a specific peak wavelength and various kinds of fluorescent powder; determining l target type solar white light color points on the black body radiation line, and calculating to obtain l groups of luminous flux parameters; and selecting one group of luminous flux parameters from the l groups of luminous flux parameters according to a preset target, and controlling the m LED lamp beads to form mixed light, namely sun-like white light. According to the combination of different intensities of various light sources, the problem that an existing full-spectrum white-light LED emits white light by exciting fluorescent powder from a single wave band and has a single color temperature is changed into multi-wave-band LED chip mixed dimming, the sunken part of the wave band about 480 nm of the spectrum is filled, the color rendering index is higher, the mixed spectrum is more continuous, and the light emitting efficiency is improved. And sunlight-like dimming along black-body radiation rays can be realized.

Description

Technical Field

[0001] The present invention relates to the field of LED healthy lighting, and in particular to a method for generating sunlight-like white light by mixing LEDs and an LED lamp group. Background Art

[0002] As a new type of lighting source, white light LED has significant advantages over traditional fluorescent lamps and incandescent lamps: energy saving, environmental protection, fast response speed, long service life, etc. At present, the LED industry is booming, the luminous efficiency of LED is constantly improving, and the price is decreasing year by year. Therefore, white light LED is gradually replacing traditional lighting equipment and widely entering the market.

[0003] With the rapid popularization of white light LEDs in the lighting field, the market's requirements for their quality are getting higher and higher, especially in the field of indoor lighting. Initially, the demand for white light LEDs only focused on their "high brightness", but now more attention is paid to light color performance, such as color rendering index, color temperature, etc., and even the pursuit of full-spectrum lighting similar to sunlight. In order to meet market demand, packaging companies at home and abroad have accelerated the research and development of full-spectrum white light LED products.

[0004] At present, there are two main ways to realize full-spectrum white light LEDs: multi-chip type and single-chip type. Multi-chip type LEDs use the principle of three primary colors to integrate multiple LED chips that emit red, green, and blue light and mix them in proportion to obtain white light. Although this technology can flexibly adjust the color and color temperature by controlling the current of each LED chip, and the color gamut is wide, the global color rendering index is not high; single-chip full-spectrum white light LEDs are simpler, lower cost, and have a more continuous spectrum, but the color temperature is not adjustable. Traditional LEDs achieve full-spectrum sunlight-like white light illumination, mainly using single lamp beads to encapsulate LED chips and multi-color phosphors. The color temperature is single and cannot be adjusted, and the continuity of the spectrum is poor, especially in the cyan band around 480nm, where the wavelength range overlaps with the excitation spectrum of long-wavelength phosphors, resulting in absorption and depression; using two-color lamp beads for dimming, the color point of the color adjustment is on the straight line formed by the two-color color points, deviating from the curved blackbody radiation line, and the white light is not pure. Blue light chip technology has spectrum missing in the blue-green part, and its color performance is not ideal. Although the purple light / near-ultraviolet chip technology has good continuity in the blue-green part, it also has problems such as low color rendering index and high production cost. Therefore, it is of great significance to seek new white light LED technology to overcome the problems of current technology. Summary of the invention

[0005] The purpose of the present invention is to at least partially solve the above-mentioned technical problems, and to provide a method for producing sunlight-like white light by mixing LEDs and an LED lamp group.

[0006] A first aspect of the present invention provides a method for generating sunlight-like white light by mixing LEDs, the method comprising the following steps:

[0007] 1) Select m color points in the CIE1931 color coordinate diagram, m≥3, m∈Z, and use the m color points as vertices to enclose a dimming area, wherein the dimming area includes all or part of the black body radiation within the color temperature range of 2700K-6500K;

[0008] 2) In the 400nm-460nm band, m peak wavelengths are determined as the peak wavelengths of m LED chips according to the selected m color points; in the 460nm-700nm band, n peak wavelengths are selected as the peak wavelengths of n types of phosphors; m≤n≤5, n∈Z;

[0009] The determination of m peak wavelengths and n peak wavelengths both satisfy the following first rule:

[0010] In the formula, λ P1 ,λ P2 are two adjacent peak wavelengths, λ P2 -λ P1 | is the absolute value of the difference between two adjacent peak wavelengths, Δλ1, Δλ2 are λ P1 ,λ P2 The half-wave width;

[0011] 3) For each of the m LED chips, 0-n types of phosphors are selected from the n types of phosphors and then packaged independently to obtain m LED lamp beads, the light emitted by the LED lamp beads when powered on corresponds to the m color points;

[0012] Each LED chip selects 0-n phosphors from the n phosphors and the following second rule must be met:

[0013] The emission spectrum band of the LED chip is within the excitation spectrum band of the phosphor;

[0014] 4) determining l target-type solar white light color points on the black body radiation line within the dimming area, and calculating the luminous flux of each of the m LED lamp beads for each target-type solar white light color point, to obtain l groups of luminous flux parameters;

[0015] 5) According to a preset target, a group of luminous flux parameters is selected from the l groups of luminous flux parameters to control the m LED lamp beads to form mixed light, that is, sunlight-like white light.

[0016] Furthermore, the calculation of the luminous flux of each of the m LED lamp beads for each target-type solar white light color point is specifically as follows: a target-type solar white light color point is selected, and the luminous flux of the m LED chips is calculated according to m color points, the target-type solar white light color point and a preset target-type solar white light luminous flux, wherein the target-type solar white light color point is a color point on the blackbody radiation line within the dimming area.

[0017] Furthermore, when m is 3, the coordinates of the three color points are A(x A ,y A ), B(x B ,y B ), C(x C ,y C ), the coordinates of the target solar white light color point are W(x W ,y W ), the luminous flux of the three LED lamp beads is calculated according to the following formula:

[0018]

[0019] Among them, φ W is the luminous flux of the preset target type of sunlight white light; φ A ,φ B ,φ C is the luminous flux of three LED lamp beads.

[0020] Furthermore, the n types of phosphors include phosphors with a peak wavelength range of 470nm-490nm, and the phosphors with a peak wavelength range of 470nm-490nm are combined with an LED chip with the smallest peak wavelength among the m LED chips and then packaged independently.

[0021] According to a second aspect of the present invention, there is provided an LED lamp group for generating sunlight-like white light, characterized in that the LED lamp group comprises m LED lamp beads, m≥3, m∈Z; each LED lamp bead is independently packaged, each LED lamp bead comprises an LED chip and 0-n kinds of phosphors, the color point of each LED lamp bead is selected from the area around the black body radiation line in the CIE1931 color coordinate diagram, and the peak wavelength of the LED chip contained in each LED lamp bead is different; each LED lamp bead is used to emit light of corresponding color point through the LED chip contained therein under a set luminous flux, or to form mixed light after emitting light of corresponding color point through the LED chip contained therein to excite the corresponding phosphor; in the LED lamp bead, the emission spectrum band of the LED chip is within the excitation spectrum band of the phosphor.

[0022] Furthermore, the peak wavelength of the LED chip is between 400nm and 460nm, and the peak wavelength range of the phosphor is between 470nm and 505nm at the lowest and between 660nm and 690nm at the highest.

[0023] Furthermore, the peak wavelengths of the LED chips included in the m LED lamp beads are spaced between 10 nm and 20 nm.

[0024] Furthermore, the m LED lamp beads include independently packaged first LED lamp beads, and the phosphor in the first LED lamp beads has a peak wavelength in the range of 470nm-490nm.

[0025] Further, the LED lamp group includes a first LED lamp bead, a second LED lamp bead and a third LED lamp bead;

[0026] The peak wavelength of the LED chip in the first LED lamp bead is 415nm-420nm, which excites the phosphor with a peak wavelength of 480nm-490nm, and the ratio of the LED peak intensity to the phosphor peak intensity is 1:1.5-1:4;

[0027] The peak wavelength of the LED chip in the second LED lamp bead is 430nm-435nm, and the excitation peak wavelength is 520nm-540nm, 560nm-580nm phosphor, and the ratio of the peak intensity of the LED chip to the peak intensity of the phosphor is 1:1:1-1:3:3;

[0028] The peak wavelength of the LED chip in the third LED lamp bead is 445nm-455nm, and the excitation peak wavelength is 560nm-580nm, 615nm-635nm, 660nm-690nm. The ratio of LED peak intensity to phosphor peak intensity is 1:7:7:9-1:14:20:50.

[0029] Furthermore, the color point of the first lamp bead is A (0.1668, 0.2703), the peak wavelength of the LED chip contained therein is 415nm, and the phosphor with a peak wavelength of 483nm is excited, and the ratio of the peak intensity of the LED chip to the peak intensity of the phosphor is 1:1.6; the color point of the second lamp bead is B (0.4113, 0.4981), the peak wavelength of the LED chip contained therein is 430nm, and the phosphor with peak wavelengths of 530nm and 574nm is excited, and the ratio of the peak intensity of the LED chip to the peak intensity of the phosphor is 1:0.65:1.3; the color point of the third lamp bead is C (0.5832, 0.3919), the peak wavelength of the LED chip contained therein is 460nm, and the phosphor with peak wavelengths of 574nm, 627nm and 684nm is excited, and the ratio of the peak intensity of the LED chip to the peak intensity of the phosphor is 1:4:8:10.

[0030] Furthermore, the LED lamp group includes a first LED lamp bead, a second LED lamp bead, a third LED lamp bead and a fourth LED lamp bead; the color point of the first LED lamp bead is A (0.1673, 0.2726), the peak wavelength of the LED chip contained therein is 415nm, the phosphor with a peak wavelength of 483nm is excited, and the ratio of the LED peak intensity to the phosphor peak intensity is 1:2; the color point of the second LED lamp bead is B (0.1667, 0.0138), the peak wavelength of the LED chip contained therein is 430nm; the color point of the third LED lamp bead is C (0 .4420,0.5010), the peak wavelength of the LED chip it contains is 445nm, and it excites phosphors with peak wavelengths of 530nm and 574nm, and the ratio of LED peak intensity to phosphor peak intensity is 1:2.4:3.2; the color point in the fourth LED lamp bead is D(0.6323,0.3619), the peak wavelength of the LED chip it contains is 460nm, and it excites phosphors with peak wavelengths of 574nm, 627nm, and 684nm, and the ratio of LED peak intensity to phosphor peak intensity is 1:10:70:100.

[0031] Compared with the prior art, the present invention has at least one of the following advantages or at least part of one of the advantages:

[0032] (1) The method for producing sunlight-like white light by mixing LEDs provided in the present invention uses multi-peak wavelength LED chips and phosphors for mixed dimming. First, suitable LED chips and phosphors are selected to cover the entire visible light band, and then they are split into multiple pieces. Each lamp bead excites the corresponding phosphor with LED chips of different bands to produce a light source to be combined. The light fluxes of the individual LED lamp beads are adjusted for mixing and the spectra are superimposed to obtain sunlight-like white light with a continuous spectrum closer to the sunlight spectrum. The spectral characteristics are similar to those of sunlight, and the hazards of short-wavelength blue light are removed. Purple light does not appear and blue indigo does not sink.

[0033] (2) The technical solution provided by the present invention selects different color points from the black body radiation line within the dimming area to calculate different luminous flux parameter combinations, that is, different luminous flux parameters correspond to solar-like white light of different color temperatures. By changing the luminous flux (selecting different luminous flux parameter combinations), dimming and color adjustment along the black body radiation line is achieved, solving the problem that the dimming color temperature of a traditional single LED chip cannot be adjusted.

[0034] (3) The LED lamp group for generating sunlight-like white light provided by the present invention separately encapsulates 480nm phosphor, thereby avoiding the problem that the emission spectrum of the 480nm phosphor overlaps with the excitation spectrum of the long-wavelength phosphor, thereby causing the 480nm band of the spectrum to be absorbed and depressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] These and / or other aspects and advantages of the present invention will become apparent and readily understood from the following description of the preferred embodiments in conjunction with the accompanying drawings, in which:

[0036] Figure 1 A triangular color adjustment area formed by three color points in CIE1931 in one embodiment of the present invention;

[0037] Figure 2 In one embodiment of the present invention, four color points form a quadrilateral color adjustment area in CIE1931;

[0038] Figure 3 A schematic diagram of a three-color LED lamp bead on a substrate provided by an embodiment of the present invention;

[0039] Figure 4 A schematic diagram of the packaging structure of an LED lamp bead provided by an embodiment of the present invention;

[0040] Figure 5 A comparison chart of the spectrum of the three-color lamp beads with low color temperature of 2700K-3500K mixed sunlight-like white light provided in Example 1 of the present invention;

[0041] Figure 6 A comparison chart of the spectrum of the three-color lamp beads with high color temperature of 4000K-6500K mixed sunlight-like white light provided in Example 2 of the present invention;

[0042] Figure 7 The four-color lamp beads 2700K-6500K mixed solar white light spectrum provided in Example 3 of the present invention. DETAILED DESCRIPTION

[0043] The technical solution of the present invention is further specifically described below by examples and in conjunction with the accompanying drawings. In the specification, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the overall inventive concept of the present invention and should not be construed as a limitation of the present invention.

[0044] An embodiment of the present invention provides a method for generating sunlight-like white light by mixing LEDs, comprising the following steps:

[0045] S1. Select m color points in the CIE1931 color coordinate diagram, m≥3, m∈Z, and enclose a dimming area with the m color points as vertices, wherein the dimming area includes all or part of the black body radiation within the color temperature range of 2700K-6500K.

[0046] In one embodiment of the present invention, m is 3, and a triangular area formed by three color points as vertices is a dimming area, such as Figure 1 shown.

[0047] In one embodiment of the present invention, m is 4, and a quadrilateral area surrounded by four color points as vertices is a dimming area, such as Figure 2 shown.

[0048] S2. In the 400nm-460nm band, m peak wavelengths are determined as the peak wavelengths of m LED chips according to the selected m color points; in the 460nm-700nm band, n peak wavelengths are selected as the peak wavelengths of n types of phosphors; m≤n≤5, n∈Z;

[0049] The determination of the m peak wavelengths and the n peak wavelengths both satisfy the following first rule:

[0050] In the formula, λ P1 ,λ P2 are two adjacent peak wavelengths, |λ P2 -λ P1 | is the absolute value of the difference between two adjacent peak wavelengths, Δλ1, Δλ2 are λ P1 ,λ P2 The half-wave width;

[0051] The peak wavelength of the LED chip is within the range of 400nm-460nm, and the peak wavelength of each LED chip in the m LED chips is 10nm-20nm apart. The peak wavelength of the phosphor is within the range of 460nm-700nm, divided into n types, covering the entire visible light band of 400nm-700nm.

[0052] In one embodiment of the present invention, the n types of phosphors include phosphors with a peak wavelength range of 470nm-490nm, and the phosphors with a peak wavelength range of 470nm-490nm are combined with an LED chip with the smallest peak wavelength among the m LED chips and then packaged independently.

[0053] In one embodiment of the present invention, when m is 3, the peak wavelengths of the three LED chips are selected from three bands: 410nm-420nm, 425nm-435nm, and 440nm-460nm.

[0054] In one embodiment of the present invention, when m is 3, the peak wavelengths of the three LED chips are selected within the three bands of 415nm-420nm, 430nm-435nm and 445nm-455nm.

[0055] In one embodiment of the present invention, n is 5, and the peak wavelengths of the five phosphors are selected from five bands of 470nm-500nm, 520nm-540nm, 560nm-590nm, 615nm-635nm, and 660nm-690nm.

[0056] S3. For each of the m LED chips, 0-n types of phosphors are selected from the n types of phosphors and then packaged independently to emit light of corresponding color points.

[0057] When selecting phosphor, it is necessary not only to consider the color point of the light, but also to consider whether the emission spectrum band of the LED chip is within the excitation spectrum band of the phosphor.

[0058] Specifically, the phosphors with peak wavelengths in the five bands of 470nm-500nm, 520nm-540nm, 560nm-590nm, 615nm-635nm, and 660nm-690nm have corresponding excitation spectrum bands of 380nm-420nm, 380nm-450nm, 380nm-450nm, 380nm-480nm, and 380nm-480nm.

[0059] In one embodiment of the present invention, a shorter peak wavelength LED chip excites a phosphor with a shorter peak wavelength, and a longer peak wavelength LED chip excites a phosphor with a longer peak wavelength.

[0060] In one embodiment of the present invention, in the case of three LED lamp beads, the LED chip with a peak wavelength of 410nm-420nm excites the phosphor with a peak wavelength of 480nm-500nm, the LED chip with a peak wavelength of 425nm-435nm excites the phosphor with a peak wavelength of 520nm-580nm, and the LED chip with a peak wavelength of 440nm-460nm excites the phosphor with a peak wavelength of 570nm-690nm.

[0061] In one embodiment of the present invention, in the case of 3 LED lamp beads, each packaged LED lamp bead excites the corresponding phosphor with an LED chip of a different band to reach the corresponding color point, the LED chip with a peak wavelength of 415nm-420nm excites the phosphor with a peak wavelength of 480nm-490nm, and the ratio of the LED peak intensity to the phosphor peak intensity is 1:1.5-1:4; the LED chip with a peak wavelength of 430nm-435nm excites the phosphor with a peak wavelength of 520nm-540nm and 560nm-580nm, and the ratio of the LED peak intensity to the phosphor peak intensity is 1:1:1-1:3:3; the LED chip with a peak wavelength of 445nm-455nm excites the phosphor with a peak wavelength of 560nm-580nm, 615nm-635nm, and 660nm-690nm, and the ratio of the LED peak intensity to the phosphor peak intensity is 1:7:7:9-1:14:20:50.

[0062] In one embodiment of the present invention, m is 3, and the three LED lamp beads are designed as follows:

[0063] The color point of the first LED lamp bead is A (0.1668, 0.2703), the peak wavelength of the LED chip contained therein is 415nm, the phosphor with a peak wavelength of 483nm is excited, and the ratio of the peak intensity of the LED chip to the peak intensity of the phosphor is 1:1.6;

[0064] The color point of the second LED lamp bead is B (0.4113, 0.4981), the peak wavelength of the LED chip contained therein is 430nm, the peak wavelength of the excitation phosphor is 530nm and 574nm, and the ratio of the peak intensity of the LED chip to the peak intensity of the phosphor is 1:0.65:1.3;

[0065] The color point of the third LED lamp bead is C (0.5832, 0.3919), the peak wavelength of the LED chip it contains is 460nm, the excitation peak wavelengths are 574nm, 627nm, and 684nm phosphors, and the ratio of the LED chip peak intensity to the phosphor peak intensity is 1:4:8:10.

[0066] In one embodiment of the present invention, m is 4, and the 4 LED lamp beads are designed as follows:

[0067] The color point of the first LED lamp bead is A (0.1673, 0.2726), the peak wavelength of the LED chip contained therein is 415nm, the phosphor with a peak wavelength of 483nm is excited, and the ratio of the LED peak intensity to the phosphor peak intensity is 1:2;

[0068] The color point of the second LED lamp bead is B (0.1667, 0.0138), and the peak wavelength of the LED chip it contains is 430nm; at this time, the color point of the light emitted by the single LED chip meets the requirements of forming a mixed color quadrilateral area, and no fluorescent powder is required.

[0069] The color point of the third LED lamp bead is C (0.4420, 0.5010), the peak wavelength of the LED chip contained therein is 445nm, the peak wavelength of the excitation phosphor is 530nm and 574nm, and the ratio of the LED peak intensity to the phosphor peak intensity is 1:2.4:3.2;

[0070] The color point of the fourth LED lamp bead is D (0.6323, 0.3619), the peak wavelength of the LED chip it contains is 460nm, the excitation peak wavelengths are 574nm, 627nm, and 684nm phosphors, and the ratio of LED peak intensity to phosphor peak intensity is 1:10:70:100.

[0071] S3. Determine l target-type solar white light color points on the blackbody radiation line within the dimming area, and calculate the luminous flux of each LED lamp bead in the m LED lamp beads for each target-type solar white light color point to obtain l groups of luminous flux parameters.

[0072] In one embodiment of the present invention, the luminous flux of each of m LED lamp beads is calculated for a target type solar white light color point as follows: the luminous flux of the m LED lamp beads is calculated based on the m color points, the target type solar white light color point and the preset target type solar white light luminous flux.

[0073] When m is 3, the coordinates of the target solar white light color point are W(x W ,y W ), the coordinates of the three color points are A(x A ,y A ), B(x B ,y B ), C(x C ,y C ), establish the three-color lighting mathematical model shown in formula (1):

[0074]

[0075] Among them, φW is the luminous flux of the preset target type of sunlight white light; φ A ,φ B ,φ C is the luminous flux of three LED lamp beads.

[0076] Simplified, the calculation formula for the luminous flux of three LED lamp beads can be obtained, as shown in formula (2):

[0077]

[0078] Among them, φ W is the luminous flux of the preset target type of sunlight white light; φ A ,φ B ,φ C is the luminous flux of three LED lamp beads.

[0079] S4. Selecting a group of luminous flux parameters from the l groups of luminous flux parameters according to a preset target, for controlling the m LED lamp beads to form mixed light, that is, sunlight-like white light.

[0080] The embodiment of the present invention calculates different luminous flux parameters from different color points selected on the blackbody radiation line within the dimming area, that is, different luminous flux parameters correspond to solar-like white light of different color temperatures. By selecting different luminous flux parameters, dimming and color adjustment along the blackbody radiation line is achieved.

[0081] Example 1

[0082] An embodiment of the present invention provides an LED lamp group for generating sunlight-like white light. The light-emitting device includes a bracket or a substrate, lamp beads of three colors and a control system.

[0083] like Figure 3 As shown, an embodiment of the present invention provides a light-emitting device, which includes a bracket or a substrate, three groups of three-color LED lamp beads and a control system. The schematic diagram of the packaging structure of each LED lamp bead is as follows Figure 4 As shown, it includes an LED chip bracket 1, an LED chip 2 is placed on the chip bracket 1, and finally a layer of phosphor layer is covered in the bracket groove, covering the LED chip and being flush with the upper surface of the bracket.

[0084] The chip and phosphor combination used in this embodiment are as follows:

[0085] Lamp bead A uses an LED chip with a peak wavelength of 415nm, which excites the blue phosphor to emit a spectrum with a peak wavelength of 483nm and a half-peak width of 86nm.

[0086] Lamp bead B uses an LED chip with a peak wavelength of 430nm, which excites the green phosphor to emit a spectrum with a peak wavelength of 529nm and a half-peak width of 106nm; the yellow phosphor emits a spectrum with a peak wavelength of 574nm and a half-peak width of 129nm;

[0087] Lamp bead C uses an LED chip with a peak wavelength of 460nm, which excites the yellow phosphor to emit a spectrum with a peak wavelength of 574nm and a half-peak width of 129nm; the short-wavelength red phosphor emission spectrum has a peak wavelength of 627nm and a half-peak width of 76nm; the long-wavelength red phosphor emission spectrum has a peak wavelength of 684nm and a half-peak width of 92nm.

[0088] Apply solder paste on the bracket, place the LED chip on the heating platform at 260 degrees Celsius to heat and fix the chip, cover it with AB glue mixed with phosphor, the ratio of lamp bead A to powder and glue is 1:4; the ratio of lamp bead B to powder and glue is 1:6, the ratio of green phosphor to yellow phosphor is 2:3; the ratio of lamp bead C to powder and glue is 1:3, the ratio of yellow phosphor to short-wavelength red phosphor to long-wavelength red phosphor is 8:2:3; use a remote integrating sphere to test, after the test is passed, bake the lamp bead at 80 degrees Celsius for 1 hour and then at 150 degrees Celsius for 3 hours to solidify the glue mixed with phosphor.

[0089] The color point coordinates of 3 LED lamp beads and the color point coordinates of the target type of solar white light are selected as: A (0.1668, 0.2703), B (0.4113, 0.4981), and C (0.5832, 0.3919).

[0090] The target solar white light color point coordinates W(x W ,y W ) is substituted into formula (2) to obtain the luminous flux of each LED lamp bead under different target types of solar white light color points, and the mixed light source information is obtained as shown in Table 1.

[0091] Table 1

[0092] CCT 2732 2975 3477 <![CDATA[x w ]]> 0.461 0.440 0.407 <![CDATA[y w ]]> 0.415 0.405 0.392 RA 95.3 98.5 96.5 R1 96.8 99.1 95.5 R2 95.7 99.4 97.4 R3 91.7 95.2 98.3 R4 97.2 98.0 95.6 R5 95.3 99.6 95.8 R6 92.9 98.6 96.7 R7 97.4 98.7 97.6 R8 95.7 99.0 94.7 R9 86.9 98.7 88.6 R10 87.7 96.5 95.5 R11 97.1 97.8 94.6 R12 85.9 96.6 95.0 R13 96.2 99.4 95.6 R14 94.5 96.6 98.5 R15 96.3 99.0 95.2

[0093] In Table 1, CCT is the correlated color temperature, which refers to the temperature of a hypothetical black body at a specific temperature when the light radiated by the light source to be measured matches the color of the light emitted by the light source to be measured and the point on the vertical line of the black body radiation line. Its unit is Kelvin (K), and its calculation formula is

[0094] CCT=-437n 3 +3601n 2 -6831 n+5517

[0095] Where: n = (x-0.3320) / (y-0.1858), where (x, y) is the coordinate of the light source to be measured in the CIE1931 color coordinate diagram, and CCT is the correlated color temperature.

[0096] The color rendering index is an indicator that measures the accuracy and consistency of the color displayed by a light source, and is often used to evaluate the quality of artificial light sources. The higher the color rendering index (0-100), the closer the color displayed by the light source is to the natural state, and the better the color rendering performance. It is calculated by the color difference between the standard light source and the light source to be tested under 15 standard colors. The formula for each special color rendering index is:

[0097] R i =100-4.6ΔE i (i=1,···,15)

[0098] The general color rendering index R is usually used a Measuring the color rendering performance of light sources

[0099]

[0100] In this embodiment, the comparison chart of the spectrum of the three-color lamp beads with low color temperature of 2700K-3500K mixed sunlight-like white light is as follows: Figure 5 As shown, Figure 5 Figure (1) is the spectral curve (relative optical power spectral density function) corresponding to points A, B, and C; Figure (2) is a comparison of the relative spectrum of the sunlight-like LED and the relative spectrum of the traditional LED at a color temperature of 2700K; Figure (3) is a comparison of the relative spectrum of the sunlight-like LED and the relative spectrum of the traditional LED at a color temperature of 3000K; Figure (4) is a comparison of the relative spectrum of the sunlight-like LED and the relative spectrum of the traditional LED at a color temperature of 3500K. Figure 5 It can be seen that in the low color temperature range of 2700K-3500K, the spectrum of sunlight-like LED light source is more complete and continuous than that of traditional LED light source, and blue light does not appear. It is a healthy, high-quality full-spectrum sunlight-like lighting source.

[0101] Example 2

[0102] An LED lamp group for generating sunlight-like white light is basically the same as Example 1, and the powder-to-glue ratio and the phosphor ratio in the lamp beads are adjusted, with more emphasis on the light source quality at high color temperature.

[0103] The powder-to-glue ratio of lamp bead A is 1:4.6; the powder-to-glue ratio of lamp bead B is 1:10, and the ratio of green phosphor to yellow phosphor is 2:5; the powder-to-glue ratio of lamp bead C is 1:3, and the ratio of yellow phosphor to short-wavelength red phosphor to long-wavelength red phosphor is 16:4:5; use a remote integrating sphere test, and after the test passes, bake the lamp bead at 80 degrees Celsius for 1 hour and then at 150 degrees Celsius for 3 hours to solidify the glue mixed phosphor. According to step 1, the lamp bead color point coordinates A (0.1668, 0.2682), B (0.4388, 0.4664), C (0.5804, 0.3942) and the relative optical power spectral density function are obtained. Substitute the target color point coordinates into step 3 to obtain the luminous flux of lamp beads of various colors, and obtain the mixed light source information as shown in Table 2:

[0104] Table 2

[0105]

[0106]

[0107] In this embodiment, the comparison chart of the spectrum of the three-color lamp bead with high color temperature of 4000K-6500K mixed sunlight-like white light is shown in Figure 6. Figure 6 Figure (1) is the spectral curve (relative optical power spectral density function) corresponding to points A, B, and C; Figure (2) is a comparison of the relative spectrum of the sunlight-like LED and the relative spectrum of the traditional LED at a color temperature of 4000K; Figure (3) is a comparison of the relative spectrum of the sunlight-like LED and the relative spectrum of the traditional LED at a color temperature of 5000K; Figure (4) is a comparison of the relative spectrum of the sunlight-like LED and the relative spectrum of the traditional LED at a color temperature of 6500K. Figure 6 It can be seen that in the high color temperature range of 4000K-6500K, compared with traditional LED light sources, the sunlight-like LED light source has a wider blue light band at high color temperature, and the 480nm band is not concave, which makes the overall light source more complete and continuous, and the properties of the light source are similar to sunlight.

[0108] Example 3

[0109] A white light LED mixing system includes four types of LED lamp beads; wherein the packaging structure of each LED lamp bead is basically the same as that of Example 1, and the dimming of the four-color lamp beads is adjustable, and the high-quality sunlight-like white light range is wider.

[0110] The chip and phosphor combination used in this embodiment are as follows:

[0111] Lamp bead A uses an LED chip with a peak wavelength of 415nm, which excites the blue phosphor to emit a spectrum with a peak wavelength of 483nm and a half-peak width of 86nm.

[0112] Lamp bead B is individually packaged using LED chips with a peak wavelength of 430nm.

[0113] Lamp bead C uses an LED chip with a peak wavelength of 445nm, which excites the green phosphor to emit a spectrum with a peak wavelength of 529nm and a half-peak width of 106nm; the yellow phosphor emits a spectrum with a peak wavelength of 574nm and a half-peak width of 129nm;

[0114] Lamp bead D uses an LED chip with a peak wavelength of 460nm, which excites the yellow phosphor to emit a spectrum with a peak wavelength of 574nm and a half-peak width of 129nm; the short-wavelength red phosphor emission spectrum has a peak wavelength of 627nm and a half-peak width of 76nm; the long-wavelength red phosphor emission spectrum has a peak wavelength of 684nm and a half-peak width of 92nm.

[0115] Apply solder paste on the bracket, place the LED chip on the heating platform at 260 degrees Celsius to heat and fix the chip, cover it with AB glue mixed with phosphor, the powder-glue ratio of lamp bead A is 1:3.5; lamp bead B is separately glued and packaged; lamp bead C has a powder-glue ratio of 1:4, and the ratio of green phosphor to yellow phosphor is 2:3; lamp bead D has a powder-glue ratio of 1:2, and the ratio of yellow phosphor to short-wavelength red phosphor to long-wavelength red phosphor is 8:2:3; use a remote integrating sphere to test, and after the test passes, bake the lamp bead at 80 degrees Celsius for 1 hour and then at 150 degrees Celsius for 3 hours to solidify the glue mixed with phosphor.

[0116] The color point coordinates of 4 LED lamp beads and the color point coordinates of the target type solar white light are selected as: A (0.1673, 0.2726), B (0.1667, 0.0138), C (0.4420, 0.5010), and D (0.6323, 0.3619).

[0117] The target solar white light color point coordinates W(x W ,y W ) is substituted into formula (2) to obtain the luminous flux of each LED lamp bead under different target types of solar white light color points, and the mixed light source information is obtained as shown in Table 3.

[0118] Table 3

[0119]

[0120]

[0121] In this embodiment, the four-color lamp beads 3000K-6500K mixed sunlight white light spectrum is as follows Figure 7 As shown,

[0122] Figure 7(a) is 2700K; (b) is 3000K; (c) is 3500K; (d) is 4000K; (e) is 5000K; and (f) is 6500K.

[0123] according to Figure 7 As can be seen from Table 3, the lack of cyan band in the traditional LED spectrum is effectively solved, so that the spectrum of the hybrid light source is complete and continuous, and similar to the spectrum of natural light. The color rendering index of the dimming color temperature 2700-6500K along the blackbody radiation line is greater than 98, and R9-R15 is greater than 90. Compared with ordinary high color rendering index LEDs, the spectrum is more complete and continuous, which is of certain important significance to the field of healthy lighting.

[0124] Compared with the prior art, the present invention has at least one of the following advantages or at least part of one of the advantages:

[0125] (1) The method for producing sunlight-like white light by mixing LEDs provided in the present invention uses multi-peak wavelength LED chips and phosphors for mixed dimming. First, suitable LED chips and phosphors are selected to cover the entire visible light band, and then they are split into multiple pieces. Each lamp bead excites the corresponding phosphor with LED chips of different bands to produce a light source to be combined. The light fluxes of the individual LED lamp beads are adjusted for mixing and the spectra are superimposed to obtain sunlight-like white light with a continuous spectrum closer to the sunlight spectrum. The spectral characteristics are similar to those of sunlight, and the hazards of short-wavelength blue light are removed. Purple light does not appear and blue indigo does not sink.

[0126] (2) The technical solution provided by the present invention selects different color points from the black body radiation line within the dimming area to calculate different luminous flux parameter combinations, that is, different luminous flux parameters correspond to solar-like white light of different color temperatures. By changing the luminous flux (selecting different luminous flux parameter combinations), dimming and color adjustment along the black body radiation line is achieved, solving the problem that the dimming color temperature of a traditional single LED chip cannot be adjusted.

[0127] (3) The LED lamp group for generating sunlight-like white light provided by the present invention separately encapsulates 480nm phosphor, thereby avoiding the problem that the emission spectrum of the 480nm phosphor overlaps with the excitation spectrum of the long-wavelength phosphor, thereby causing the 480nm band of the spectrum to be absorbed and depressed.

[0128] Although some embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the present general inventive concept, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for generating sunlight-like white light by mixing LEDs, characterized in that: The method comprises the following steps: 1) Select m color points in the CIE1931 color coordinate diagram, m≥3, m∈Z, and use the m color points as vertices to enclose a dimming area, wherein the dimming area includes all or part of the black body radiation within the color temperature range of 2700K-6500K; 2) In the 400nm-460nm band, m peak wavelengths are determined as the peak wavelengths of m LED chips according to the selected m color points; in the 460nm-700nm band, n peak wavelengths are selected as the peak wavelengths of n types of phosphors; m≤n≤5, n∈Z; The determination of m peak wavelengths and n peak wavelengths both satisfy the following first rule: In the formula, λ P1 ,λ P2 are two adjacent peak wavelengths, λ P2 -λ P1 | is the absolute value of the difference between two adjacent peak wavelengths, Δλ1, Δλ2 are the peak wavelengths of λ P1 ,λ P2 The half-wave width corresponding to the LED chip or phosphor; 3) For each of the m LED chips, 0-n types of phosphors are selected from the n types of phosphors and then packaged independently to obtain m LED lamp beads, the light emitted by the LED lamp beads when powered on corresponds to the m color points; Each LED chip selects 0-n phosphors from the n phosphors and the following second rule must be met: The emission spectrum band of the LED chip is within the excitation spectrum band of the phosphor; 4) determining l target-type solar white light color points on the black body radiation line within the dimming area, and calculating the luminous flux of each of the m LED lamp beads for each target-type solar white light color point, to obtain l groups of luminous flux parameters; 5) According to a preset target, a group of luminous flux parameters is selected from the l groups of luminous flux parameters to control the m LED lamp beads to form mixed light, that is, sunlight-like white light.

2. The method for generating sunlight-like white light by mixing LEDs according to claim 1, characterized in that: The method of calculating the luminous flux of each of the m LED lamp beads for each target class solar white light color point is specifically as follows: a target class solar white light color point is selected, and the luminous flux of the m LED lamp beads is calculated based on m color points, the target class solar white light color point and the preset target class solar white light luminous flux.

3. The method for generating sunlight-like white light by mixing LEDs according to claim 2, characterized in that: When m is 3, the coordinates of the three color points are A(x A ,y A ), B(x B ,y B ), C(x C ,y C ), the coordinates of the target solar white light color point are W(x W ,y W ), the luminous flux of the three LED lamp beads is calculated according to the following formula: Among them, φ W is the luminous flux of the preset target type of sunlight white light; φ A ,φ B ,φ C is the luminous flux of three LED lamp beads.

4. The method for generating sunlight-like white light by mixing LEDs according to claim 1, characterized in that: The n kinds of phosphors include phosphors with a peak wavelength range of 470nm-490nm, and the phosphors with a peak wavelength range of 470nm-490nm are combined with an LED chip with the smallest peak wavelength among the m LED chips and then independently packaged.

5. An LED lamp assembly for generating sunlight-like white light, characterized in that: The LED lamp group includes m LED lamp beads, m≥3, m∈Z; each LED lamp bead is independently packaged, each LED lamp bead includes an LED chip and 0-n types of phosphors, n∈Z, the color point of each LED lamp bead is selected from the area around the black body radiation line in the CIE1931 color coordinate diagram, and the peak wavelength of the LED chip contained in each LED lamp bead is different; Each of the LED lamp beads is used to emit light of a corresponding color point through the LED chip contained therein under a set luminous flux, or to generate mixed light after the LED chip contained therein excites the corresponding phosphor to emit light of a corresponding color point; In the LED lamp bead, the emission spectrum band of the LED chip is within the excitation spectrum band of the phosphor.

6. The LED lamp assembly for generating sunlight-like white light according to claim 5, characterized in that: The peak wavelength of the LED chip is between 400nm and 460nm, and the peak wavelength range of the phosphor is between 470nm and 505nm at the lowest and between 660nm and 690nm at the highest.

7. The LED lamp assembly for generating sunlight-like white light according to claim 5, characterized in that: The peak wavelengths of the LED chips contained in the m LED lamp beads are spaced between 10nm and 20nm.

8. The LED lamp assembly for generating sunlight-like white light according to claim 5, characterized in that: The m LED lamp beads include independently packaged first LED lamp beads, and the phosphor in the first LED lamp bead has a peak wavelength in the range of 470nm-490nm.

9. The LED lamp assembly for generating sunlight-like white light according to claim 5, characterized in that: The LED lamp group includes a first LED lamp bead, a second LED lamp bead and a third LED lamp bead; The peak wavelength of the LED chip in the first LED lamp bead is 415nm-420nm, which excites the phosphor with a peak wavelength of 480nm-490nm, and the ratio of the LED peak intensity to the phosphor peak intensity is 1:1.5-1:4; The peak wavelength of the LED chip in the second LED lamp bead is 430nm-435nm, and the excitation peak wavelength is 520nm-540nm, 560nm-580nm phosphor, and the ratio of the peak intensity of the LED chip to the peak intensity of the phosphor is 1:1:1-1:3:3; The peak wavelength of the LED chip in the third LED lamp bead is 445nm-455nm, and the excitation peak wavelength is 560nm-580nm, 615nm-635nm, 660nm-690nm. The ratio of LED peak intensity to phosphor peak intensity is 1:7:7:9-1:14:20:

50.

10. The LED lamp assembly for generating sunlight-like white light according to claim 5, characterized in that: The LED lamp group includes a first LED lamp bead, a second LED lamp bead, a third LED lamp bead and a fourth LED lamp bead; The color point of the first LED lamp bead is A(0.1673, 0.2726), wherein the peak wavelength of the LED chip contained therein is 415 nm, the peak wavelength of the fluorescent powder excited is 483 nm, and the ratio of the peak intensity of the LED to the peak intensity of the fluorescent powder is 1:2; The color point of the second LED lamp bead is B (0.1667, 0.0138), and the peak wavelength of the LED chip contained therein is 430nm; The color point of the third LED lamp bead is C (0.4420, 0.5010), the peak wavelength of the LED chip contained therein is 445nm, the peak wavelength of the excitation phosphor is 530nm and 574nm, and the ratio of the LED peak intensity to the phosphor peak intensity is 1:2.4:3.2; The color point of the fourth LED lamp bead is D (0.6323, 0.3619), the peak wavelength of the LED chip it contains is 460nm, the excitation peak wavelengths are 574nm, 627nm, and 684nm phosphors, and the ratio of LED peak intensity to phosphor peak intensity is 1:10:70:100.

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