Multispectral white light LED device and dimming mode

Abstract

The invention relates to the field of illumination, in particular to a multispectral white light LED device and a dimming mode. Four kinds of different fluorescent powder are respectively coated on four kinds of light-emitting chips with different emission wavelengths so as to form different emission light sources; the four light-emitting chips are packaged on the packaging support to be welded with the substrate, the metal box dam is sleeved outside the packaging support and welded with the substrate, and finally the resin lens is bonded on the metal box dam to form the sealed white light LED device. According to the white light LED device, the light emitting amount of different light emitting chips can be controlled through different bias voltages, so that combinations of different proportions are formed, and meanwhile, after being packaged, the white light LED device can be externally connected with a controller and a storage device so as to be used for setting different light emitting modes. Under the condition that the requirement of high color rendering index is guaranteed, the spectral characteristics are changed, the color temperature is adjusted, and the blackout sunlight efficiency ratio is adjusted.

Description

Technical Field

[0001] The present invention relates to the field of lighting, and in particular to a multi-spectrum white light LED device and a dimming method. Background Art

[0002] Semiconductor light emitting diodes (LEDs) are one of the most widely used and efficient light sources. The light spectrum of LEDs usually shows a single narrow peak at a wavelength determined by the structure of the light emitting chip and the composition of the semiconductor material. With the rapid development of artificial light source technology, it is now possible for LEDs to emit ultraviolet light, visible light, and infrared light.

[0003] Existing LED white light dimming technology usually uses two or three primary color light emitting chips to emit a series of different color temperatures (CCT) in the main color gamut. Using two primary color chips can emit light of the color on the straight line connecting the two primary color points in the color gamut, and using three primary color chips can emit light of the color in the triangular area formed between the three primary color points in the color gamut.

[0004] However, this method will result in the output light having only specific color points, with only one color point in the biased direction of each primary color. Therefore, there is only one spectrum when the color point is determined, which cannot meet the need to change the spectral characteristics without changing the color point. And if a three-primary color chip is used to emit white light, it is impossible to maintain a high color rendering index (Ra) within the color temperature range of 2000-10000k, and it is also impossible to adjust the dark view daylight efficiency ratio. Summary of the invention

[0005] The present invention seeks to solve the above-mentioned problem that the adjustable white light LED in the prior art cannot meet the requirement of changing the spectral characteristics without changing the color point, and can also maintain a high color rendering index in a large color temperature adjustment range, and the problem that the LED emitting white light with a three-primary color chip cannot adjust the black-to-day light efficiency ratio. In view of this, the present invention provides a multi-radiation wavelength white light LED structure and light-emitting method, which is used to solve the above-mentioned problems, can simultaneously change the spectral characteristics, adjust the color temperature, adjust the black-to-day light efficiency ratio, and can also ensure a high color rendering index.

[0006] According to the general inventive concept, the present invention achieves the above-mentioned purpose through the following technical solutions:

[0007] A multi-radiation wavelength white light LED structure, comprising:

[0008] substrate;

[0009] A packaging bracket, wherein the packaging bracket is a four-grid packaging bracket, fixedly coupled to the substrate;

[0010] A first light-emitting chip, wherein the first light-emitting chip can emit a first excitation light source within a range of 420-440 nm;

[0011] a second light-emitting chip, wherein the second light-emitting chip can emit a second excitation light source within a range of 440-460 nm;

[0012] A third light-emitting chip, wherein the third light-emitting chip can emit a third excitation light source in the range of 440-460nm;

[0013] A fourth light-emitting chip, wherein the fourth light-emitting chip can emit a fourth excitation light source within a range of 470-500 nm;

[0014] A first phosphor, which is coated on a first light-emitting chip to form a first main light source and is fixedly coupled to a packaging bracket;

[0015] A second phosphor, wherein the second phosphor is coated on the second light-emitting chip to form a second main light source and is fixedly coupled to the packaging bracket;

[0016] A third phosphor, which is coated on a third light-emitting chip to form a third main light source and is fixedly coupled to the packaging bracket;

[0017] A fourth phosphor, which is coated on a fourth light-emitting chip to form a fourth main light source and is fixedly coupled to the packaging bracket;

[0018] A metal dam surrounds the packaging bracket and is welded and fixed on the substrate;

[0019] A resin lens is arranged on the metal dam.

[0020] Furthermore, the excitation wavelength of the first phosphor is 420-440nm, and the radiation wavelength is 530-580nm; the excitation wavelength of the second phosphor is 440-460nm, and the radiation wavelength is 530-580nm; the excitation wavelength of the third phosphor is 440-460nm, and the radiation wavelength is 580-660nm; the excitation wavelength of the fourth phosphor is 470-500nm, and the radiation wavelength is 495-580nm.

[0021] Furthermore, the first main light source has a black-to-daylight efficiency ratio of less than 0.35; and the fourth main light source has a black-to-daylight efficiency ratio of greater than 0.65.

[0022] Furthermore, the first main light source has a first electrical connection for providing a first bias voltage to the first light-emitting chip; the second main light source has a second electrical connection for providing a second bias voltage to the second light-emitting chip; the third main light source has a third electrical connection for providing a third bias voltage to the third light-emitting chip; and the fourth main light source has a fourth electrical connection for providing a fourth bias voltage to the fourth light-emitting chip.

[0023] Further, the first bias voltage is used to control the light emission amount of the first light-emitting chip; the second bias voltage is used to control the light emission amount of the second light-emitting chip; the third bias voltage is used to control the light emission amount of the third light-emitting chip; the fourth bias voltage is used to control the light emission amount of the fourth light-emitting chip.

[0024] Further, the first main light source has a color point within the range of 0.18 < u' < 0.4 and v' < 0.42; the second main light source has a color point within the range of 0.18 < u' < 0.4 and v' < 0.42; the third main light source has a color point within the range of u' > 0.35 and v' > 0.53; the fourth main light source has a color point within the range of u' < 0.18 and v' > 0.25.

[0025] Further, it further includes a controller and a memory; the controller is used to provide the first bias voltage, the second bias voltage, the third bias voltage, and the fourth bias voltage, control the first light emission amount, the second light emission amount, the third light emission amount, and the fourth light emission amount, and form a combined light with multiple radiation wavelengths; the memory is used to store one or more sets of predetermined first bias voltage, second bias voltage, third bias voltage, and fourth bias voltage.

[0026] A light emission method of a white LED with multiple radiation wavelengths, and the light emission method is that according to a predetermined setting, at least one of the Ra value, CCT value, and scotopic daylight efficiency ratio of the mixed light source can be adjusted.

[0027] Further, the mixed light source can adjust the CCT value within the range of 2000K and 10000K; an Ra value greater than 80 and a scotopic daylight efficiency ratio value within the range of 0.25 to 1.39.

[0028] The technical effects of the present invention:

[0029] 1. The present invention realizes that under the condition of determining the color point, the spectrum is changed by adjusting a single light source or combined light.

[0030] 2. The present invention can adjust the color temperature within the range of 2000 - 10000K and the color rendering index within the range of 80 - 100.

[0031] 3. The present invention can adjust the scotopic daylight efficiency ratio within the range of 0.25 to 1.39. Description of the Drawings

[0032] The drawings described herein are used to provide a further understanding of the present invention, form a part of the present invention, and the schematic embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0033] In the drawings:

[0034] Figure 1 It is a schematic structural diagram of a multi-spectrum white light LED device provided by the present invention, wherein the device includes a resin lens;

[0035] Figure 2 It is a structural schematic diagram of a multi-spectrum white light LED device provided by the present invention, in which the device does not include a resin lens;

[0036] Figure 3 It is a schematic diagram of a top view structure of a multi-spectrum white light LED device provided by the present invention, in which the device does not include a resin lens;

[0037] Figure 4 The present invention is Figure 3 A schematic diagram of a half-section structure of the section line a-a';

[0038] Figure 5 It is a schematic diagram of a top view structure of a multi-spectrum white light LED device provided by the present invention, in which the device does not include a resin lens and a light-emitting chip;

[0039] Figure 6 is a color point diagram (CIE 1976) of each main light source provided by a multi-spectrum white light LED device of the present invention;

[0040] Figure 7 It is a spectrum power distribution diagram of each light-emitting chip provided by a multi-spectrum white light LED device of the present invention;

[0041] Figure 8 It is a schematic diagram of a multi-spectrum white light LED device of the present invention being packaged into a lamp and connected with a controller and a memory;

[0042] The names of the components corresponding to the various figure marks in the accompanying drawings are: 1. Multi-spectrum white light LED device; 3. Packaging bracket; 4. Substrate; 5. Metal dam; 6. Resin lens; 7. Controller; 8. Memory; 101. First light-emitting chip; 102. Second light-emitting chip; 103. Third light-emitting chip; 104. Fourth light-emitting chip; 111. First phosphor; 112. Second phosphor; 113. Third phosphor; 114. Fourth phosphor; 210. First excitation light source; 220. Second excitation light source; 230. Third excitation light source; 240. Fourth excitation light source; 310. First main light source; 320. Second main light source; 330. Third main light source; 340. Fourth main light source; 350. Black body trajectory of 2000k-10000k. DETAILED DESCRIPTION

[0043] In order to more clearly explain the overall concept of the present invention, the following is a detailed description in the form of examples in conjunction with the accompanying drawings of the specification. In the description of the present invention, it should be understood that the terms, "upper", "lower", "front", "back", "left", "right" and the like indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0044] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first" and "second" may explicitly or implicitly include one or more of the features, unless otherwise clearly and specifically defined.

[0045] In the present invention, unless otherwise clearly specified and limited, the terms "coupled", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In the present invention, unless otherwise clearly specified and limited, the first feature "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. In the description of this specification, the description with reference to the terms "one scheme", "some schemes", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the scheme or example are included in at least one scheme or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same scheme or example. Moreover, the specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more schemes or examples.

[0047] The melanopsin mentioned in the present invention is a ganglion cell protein in the retina. Melanopsin does not help people see the shape of objects clearly, but it can react with light, especially blue light, because the photosensitive protein of melanopsin is necessary for mammals to set the body's biological clock. Now this protein represents a potential target for treating and correcting disrupted circadian behavior patterns. The regulation range of melanopsin is the light environment with a full width at half maximum of 447 - 531 nm and a peak wavelength of 490 nm. This range is related to the action spectrum of melanopsin, which is a photosensitive pigment in the eye and is expressed by photoreceptors responsible for light-induced circadian rhythms. The melanopic daylight efficacy ratio is mentioned in a new standard publicly released by the CIE in 2020, which refers to the ratio of the melatonin suppression effect of the luminous radiation of a light source on the human body to that of D65 daylight radiation on the human body. Currently, this standard has been gradually and vigorously promoted. The higher the melanopic daylight efficacy ratio, the more obvious the inhibitory effect of the light source on human melatonin; the lower the ratio, the weaker the inhibitory effect on human melatonin.

[0048] First Embodiment:

[0049] A multi-spectral white LED device of the present invention is a lamp bead encapsulated by four chips. The color rendering index, color temperature, and melanopic daylight efficacy ratio of the multi-spectral white LED device 1 can be adjusted according to the scene using a bias voltage. At the same time, it can be designed according to specific usage requirements, and the multi-spectral white LED device 1 is welded on a carrier board for use.

[0050] The specific encapsulation structure includes a substrate 4, an encapsulation bracket 3, a first light-emitting chip 101, a second light-emitting chip 102, a third light-emitting chip 103, a fourth light-emitting chip 104, a first phosphor 111, a second phosphor 112, a third phosphor 113, a fourth phosphor 114, a metal dam 5, and a resin lens 6. The encapsulation bracket 3 plays a role in supporting and positioning. Four grooves are arranged in a "field" shape at the upper end of the bracket. The light-emitting chips are coated with phosphors to form main light sources, and the four main light sources are respectively welded and fixed in the four grooves of the "field"-shaped bracket. Then, the encapsulation bracket 3 with the welded chips is welded on the substrate 4, and then the metal dam 5 is welded and sleeved outside the bracket and welded and coupled with the substrate 4. Finally, the resin lens 6 is attached to the metal dam 5 to form a complete and sealed encapsulation structure. A patterned circuit layer is provided on the substrate 4 for electrical connection with the light-emitting chips. To enable each multi-spectral white LED device 1 to be dimmed, the multi-spectral white LED device 1 is provided with 8 pins, and every 2 pins are separately electrically connected to the positive and negative electrodes of the light-emitting chips.

[0051] The above-mentioned packaging structure specifically includes a first light-emitting chip 101, which is an ultraviolet light chip that can emit a first excitation light source 210 in the range of 420-440nm; a second light-emitting chip 102, which is a blue light chip that can emit a second excitation light source 220 in the range of 440-460nm; a third light-emitting chip 103, which is a blue light chip that can emit a third excitation light source 230 in the range of 440-460nm; and a fourth light-emitting chip 104, which is a cyan-blue light chip that can emit a fourth excitation light source 240 in the range of 470-500nm. It also includes a first phosphor 111, which is a green phosphor, coated on the first light-emitting chip 101 to form a first main light source 310, and fixedly coupled to the packaging bracket 3; a second phosphor 112, which is a green phosphor, coated on the second light-emitting chip 102 to form a second main light source 320, and fixedly coupled to the packaging bracket 3; a third phosphor 113, which is a red phosphor, coated on the third light-emitting chip 103 to form a third main light source 330, and fixedly coupled to the packaging bracket 3; and a fourth phosphor 114, which is a green phosphor, coated on the fourth light-emitting chip 104 to form a fourth main light source 340, and fixedly coupled to the packaging bracket 3.

[0052] The first phosphor 111 is a green phosphor with an excitation wavelength of 420-440nm and a radiation wavelength of 530-580nm, and only absorbs at most 60% of the first excitation light source 210; the second phosphor 112 is a green phosphor with an excitation wavelength of 440-460nm and a radiation wavelength of 530-580nm, and almost completely absorbs the second excitation light source 220; the third phosphor 113 is a red phosphor with an excitation wavelength of 440-460nm and a radiation wavelength of 580-660nm, and almost completely absorbs the third excitation light source 230; the fourth phosphor 114 is a green phosphor with an excitation wavelength of 470-500nm and a radiation wavelength of 495-580nm, and only absorbs at most 50% of the first excitation light source 210.

[0053] Therefore, the light emitted by the first main light source 310 is composed of a part of the first excitation light source 210 and a part of the first radiation light source; the light emitted by the second main light source 320 is all the second radiation light source; the light emitted by the third main light source 330 is all the third radiation light source; the light emitted by the fourth main light source 340 is composed of a part of the fourth excitation light source 240 and a part of the fourth radiation light source.

[0054] The green phosphor of the first phosphor 111 may be (Lu 1-x-a-b Y x G y )3(Al1-z Ga z )5O 12 :Ce a Pr b (0 < x ≤ 1, 0 < y ≤ 1, 0 < z ≤ 0.1, 0 < a ≤ 0.2, 0 < b ≤ 0.1), such as Lu3Al5O 12 :Ce 3+ or Y3Al5O 12 :Ce 3+ and other materials to emit light in the yellow - green range. The first phosphor 111 can also be Lu 3-x-y MYAl 5-z A z O 12 :Ce x (M = Y, Gd, Tb, Pr, Sin, Dy; A = Ga, Sc; 0 < x ≤ 0.2); Ca 3-x-y M y Sc 2-z A z Si3O 12 :Ce x (M = Y, Lu; A = Mg, Ga; 0 < x ≤ 0.2); Ba 2-x-y M y SiO4:Eu x (M = Sr, Ca, Mg; 0 < x ≤ 0.2); Ba 2-x-y-z M y K z Si 1-z P z O4Eu x (M = Sr, Ca, Mg; 0 < x ≤ 0.2); Sr 1-x -yM y Al 2-z Si z O 4-z N z :Eu x (M = Ba, Ca, Mg; 0 < x ≤ 0.2), etc.

[0055] The second phosphor 112 is a green phosphor of aluminum - garnet.

[0056] The third phosphor 113 is a SCASN or CASN red phosphor.

[0057] The fourth phosphor 114 has the property of absorbing a shorter - wavelength excitation light source but emitting multi - spectra, and can further enhance the emission of spectra in the range sensitive to melanopsin. So the fourth phosphor 114 can be any green phosphor that is excited by 470 - 500 nm and can emit light in the range of 495 - 580 nm.

[0058] The adjustment of the color rendering index and the scotopic daylight efficacy ratio can be achieved through the above four main light sources, and each main light source has a different emission spectrum. The first main light source 310 among the four main light sources is excited by an ultraviolet light chip (420 - 440 nm), and the second main light source 320 is excited by a blue light chip (440 - 460 nm). When these two main light sources are used, a wide range of color temperature adjustment can be achieved while ensuring a high color rendering index, and the adjustability of the scotopic daylight efficacy ratio can be realized by changing the different proportions of the combined light emitted by these two main light sources in the multi - spectral white LED device. The first main light source 310 and the second main light source 320 include green phosphors to improve their utilization rate when used in combination with the remaining two main light sources among the four main light sources, and thus increase the luminous flux and the adjustable range without compromising the color rendering index and the scotopic daylight efficacy ratio. Based on this, the first main light source 310 has a scotopic daylight efficacy ratio less than 0.35, and the fourth main light source 340 has a scotopic daylight efficacy ratio greater than 0.65.

[0059] The color rendering index, color temperature, and scotopic daylight efficacy ratio of the above multi - spectral white LED device are adjusted by changing the voltage through the controller 7. The first main light source 310 has a first electrical connection for providing a first bias voltage to the first light - emitting chip 101; the second main light source 320 has a second electrical connection for providing a second bias voltage to the second light - emitting chip 102; the third main light source 330 has a third electrical connection for providing a third bias voltage to the third light - emitting chip 103; the fourth main light source 340 has a fourth electrical connection for providing a fourth bias voltage to the fourth light - emitting chip 104. The first bias voltage is used to control the light emission amount of the first light - emitting chip 101; the second bias voltage is used to control the light emission amount of the second light - emitting chip 102; the third bias voltage is used to control the light emission amount of the third light - emitting chip 103; the fourth bias voltage is used to control the light emission amount of the fourth light - emitting chip 104.

[0060] The first main light source 310 has a color point within the range of 0.18 < u'< 0.4, v'< 0.42; the second main light source 320 has a color point within the range of 0.18 < u'< 0.4, v'< 0.42; the third main light source 330 has a color point within the range of u'> 0.35, v'> 0.53; the fourth main light source 340 has a color point within the range of u'< 0.18, v'> 0.25.

[0061] A multi-spectrum white light LED device also includes a controller 7 and a memory 8; the controller 7 is used to independently provide a first bias voltage, a second bias voltage, a third bias voltage and a fourth bias voltage to control a first light emission, a second light emission, a third light emission and a fourth light emission; the first bias voltage controls the first light emission, the second bias voltage controls the second light emission, and the third bias voltage controls the third light emission. The fourth bias voltage controls the fourth light emission, and the memory 8 is used to store one or more groups of predetermined data information of the first bias voltage, the second bias voltage, the third bias voltage and the fourth bias voltage.

[0062] The controller 7 adjusts different proportions of the first light intensity, the second light intensity, the third light intensity and the fourth light intensity to form different combined lights.

[0063] Second embodiment:

[0064] The present invention provides a dimming method for a multi-spectrum white light LED device, which can adjust at least one of the Ra value, CCT value and MDER of a mixed light source according to a predetermined setting. The mixed light source can adjust the CCT value within the range of 2000K and 10000K; the Ra value greater than 80 and the dark view daylight efficiency ratio within the range of 0.25 to 1.39.

Claims

1. A multi-spectrum white light LED device, characterized in that: It includes: base(4); A packaging bracket (3), wherein the packaging bracket (3) is a four-grid packaging bracket (3) fixedly coupled to the substrate (4); A first light-emitting chip (101), wherein the first light-emitting chip (101) can emit a first excitation light source (210) within a range of 420-440 nm; A second light-emitting chip (102), wherein the second light-emitting chip (102) can emit a second excitation light source (220) within a range of 440-460 nm; A third light-emitting chip (103), wherein the third light-emitting chip (103) can emit a third excitation light source (230) within a range of 440-460 nm; A fourth light-emitting chip (104), wherein the fourth light-emitting chip (104) can emit a fourth excitation light source (240) within a range of 470-500 nm; A first phosphor (111), the first phosphor (111) being coated on the first light-emitting chip (101) to form a first main light source (310) and fixedly coupled to the packaging bracket (3); A second phosphor (112), the second phosphor (112) being coated on the second light-emitting chip (102) to form a second main light source (320) and fixedly coupled to the packaging bracket (3); A third phosphor (113), the third phosphor (113) being coated on a third light-emitting chip (103) to form a third main light source (330), and being fixedly coupled to a packaging bracket (3); A fourth phosphor (114), the fourth phosphor (114) being coated on a fourth light-emitting chip (104) to form a fourth main light source (340), and fixedly coupled to the packaging bracket (3); A metal dam (5), the metal dam (5) surrounds the packaging bracket (3) and is fixed on the substrate (4) by welding; A resin lens (6), wherein the resin lens (6) is arranged on the metal dam (5).

2. A multi-spectrum white light LED device according to claim 1, characterized in that: The excitation wavelength of the first phosphor (111) is 420-440 nm, and the radiation wavelength is 530-580 nm; the excitation wavelength of the second phosphor (112) is 440-460 nm, and the radiation wavelength is 530-580 nm; the excitation wavelength of the third phosphor (113) is 440-460 nm, and the radiation wavelength is 580-660 nm; the excitation wavelength of the fourth phosphor (114) is 470-500 nm, and the radiation wavelength is 495-580 nm.

3. A multi-spectrum white light LED device according to claim 1, characterized in that: The first main light source (310) has a dark-vision daylight efficiency ratio of less than 0.35; and the fourth main light source (340) has a dark-vision daylight efficiency ratio of greater than 0.

65.

4. A multi-spectrum white light LED device according to claim 1, characterized in that: The first main light source (310) has a first electrical connection for providing a first bias voltage to a first light-emitting chip (101); the second main light source (320) has a second electrical connection for providing a second bias voltage to a second light-emitting chip (102); the third main light source (330) has a third electrical connection for providing a third bias voltage to a third light-emitting chip (103); and the fourth main light source (340) has a fourth electrical connection for providing a fourth bias voltage to a fourth light-emitting chip (104).

5. The multi-spectrum white light LED device according to claim 1, characterized in that: The first bias voltage is used to control the light emission amount of the first light-emitting chip (101); the second bias voltage is used to control the light emission amount of the second light-emitting chip (102); the third bias voltage is used to control the light emission amount of the third light-emitting chip (103); the fourth bias voltage is used to control the light emission amount of the fourth light-emitting chip (104).

6. The multi-spectrum white light LED device according to claim 1, characterized in that: The first main light source (310) has a color point within the range of 0.18 < u' < 0.4, v' < 0.42; the second main light source (320) has a color point within the range of 0.18 < u' < 0.4, v' < 0.42; the third main light source (330) has a color point within the range of u' > 0.35, v' > 0.53; the fourth main light source (340) has a color point within the range of u' < 0.18, v' > 0.

25.

7. A multi-spectrum white light LED device according to any one of claims 1 to 6, characterized in that: It further includes a controller (7) and a memory (8); the controller (7) is used to provide the first bias voltage, the second bias voltage, the third bias voltage and the fourth bias voltage to control the first light emission amount, the second light emission amount, the third light emission amount and the fourth light emission amount, so as to form a combined light of multiple radiation wavelengths; the memory (8) is used to store one or more sets of pre-determined first bias voltage, second bias voltage, third bias voltage and fourth bias voltage.

8. A dimming method for a multi-spectrum white light LED device, characterized in that: The dimming method is to adjust at least one of the Ra value, the CCT value and the scotopic daylight efficiency ratio of the mixed light source according to a pre-determined setting.

9. A dimming method for a multi-spectrum white light LED device according to claim 8, characterized in that The mixed light source can adjust the CCT value within the range of 2000K to 10000K; the Ra value of 80 - 100 and the scotopic daylight efficiency ratio value within the range of 0.25 to 1.39.

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