Light emitting device

Abstract

The light-emitting device provided by the embodiment of the utility model comprises a blue light unit, a green light unit, a red light unit and a warm white light unit which are used for limiting color coordinates. The light-emitting device can realize the technical effect of adjusting various colors and mixed white light color temperature of a lamp through the specific light-emitting units of the four color coordinates. The luminous intensity of the four luminous units can be independently adjusted, so that the color of the finally output light of the luminous device can be conveniently adjusted; the mixed white light with various color temperatures emitted by the light-emitting device has a good color rendering index.

Description

Technical Field

[0001] The utility model relates to the technical field of lighting, in particular to a light-emitting device. Background Art

[0002] There are some smart lighting fixtures on the market. These smart lighting fixtures generally have multiple light-emitting units of different colors, such as red, green, and blue light-emitting units and cold and warm white light-emitting units. Such smart lighting fixtures are generally called RGBCW smart lights. RGBCW smart lights can take into account the dimming of both colored light and white light. The red, green, and blue light-emitting units, namely the RGB light-emitting units, are generally responsible for color dimming, and the cold and warm white light-emitting units, namely the CW light-emitting units, are generally responsible for adjusting the color temperature of mixed white light. With the development of light-emitting diode technology, the applicant introduced a more compact smart lighting device in the previous patent application CN202310698509.7. It is composed of four different light-emitting units, but can achieve the same color light and white light dimming functions as traditional RGBCW. On this basis, the applicant further improved the smart lighting device to improve the quality of white light. Utility Model Content

[0003] In order to solve the technical problem of how to balance the dimming of colored light and white light in a compact lamp and mix white light with higher quality, the embodiment of the utility model provides a light-emitting device. The light-emitting device includes blue, green, and red light units, and a warm white light unit with a main wavelength between 570nm and 600nm. The light-emitting device realizes the output of colored light and multi-color temperature mixed white light through the above four-color light-emitting units, and can mix white light with a higher color rendering index at multiple color temperatures.

[0004] An embodiment of the utility model provides a light-emitting device including: a blue light unit for emitting blue light; a green light unit for emitting green light; a red light unit for emitting red light; and a warm white light unit, the main wavelength of which is greater than or equal to 570nm and less than or equal to 600nm; the blue light unit, the green light unit, the warm white light unit and the red light unit can cooperate to emit mixed white light and are used to adjust the color temperature of the mixed white light.

[0005] Another embodiment of the utility model provides a light-emitting device including: a blue light unit for emitting blue light; a green light unit for emitting green light; a red light unit for emitting red light; a warm white light unit, the warm white light having a color coordinate W(x, y), wherein 0.4≤x≤0.5, 0.4≤y≤0.5, and the color coordinate W(x, y) of the warm white light is located above the Planckian locus; the blue light unit, the green light unit, the warm white light unit and the red light unit can cooperate to emit mixed white light, and are used to adjust the color temperature of the mixed white light.

[0006] The technical solution provided by the embodiment of the utility model realizes a compact intelligent light-emitting device by setting four light-emitting units, and uses fewer types of light sources to achieve the technical effect of adjusting different colors and different color temperatures of white light of the light-emitting device; the main wavelength of the light emitted by the warm white light unit is limited or its color coordinates are limited, so that in the process of adjusting the white light at different color temperatures, by adjusting the current ratio of the four independently controlled light-emitting units, the white light of various color temperatures emitted by the light-emitting device is close to the black body radiation (that is, the color tolerance is less than 5SDCM) and has a good CRI, that is, the color rendering index. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0008] Figure 1 A schematic structural diagram of a light emitting device provided in an embodiment of the utility model.

[0009] Figure 2 for Figure 1 A schematic diagram of a color gamut of the light-emitting device shown in the CIE color space.

[0010] Figure 3 for Figure 1 Schematic diagram of the spectral distribution of the warm white light unit shown.

[0011] Figure 4A , Figure 4B , Figure 5A , Figure 5B for Figure 1 The diagram shown is a schematic diagram of the spectrum distribution of mixed white light emitted by the light-emitting device in different embodiments. DETAILED DESCRIPTION

[0012] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0013] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the present utility model are intended to cover non-exclusive inclusions; the definition of the numerical range is understood to include the two end values ​​unless it is explicitly stated that the two end values ​​are not included. For example, a main wavelength of 570nm to 600nm means that the main wavelength can be any value greater than or equal to 570nm and less than or equal to 600nm.

[0014] See also Figure 1 and Figure 2 , an embodiment of the utility model provides a light emitting device 10. The light emitting device 10 includes Figure 1 The blue light unit 11, green light unit 12, red light unit 13 and warm white light unit 14 are shown. The blue light unit 11 is used to emit blue light, the green light unit 12 is used to emit green light, the red light unit 13 is used to emit red light, and the warm white light unit 14 is used to emit warm white light. The four light-emitting units are electrically independent. In some embodiments, the light-emitting device 11 can modulate different colors by using the blue light unit 11, the green light unit 12 and the red light unit 13 as blue light sources, green light sources and red light sources, respectively. In the CIE color space (for example, the CIE 1931 color space), the color coordinates of the blue light unit 11 are as follows: B(x B ,y B ) point, its blue light purity>0.96, where 0.1≤x B ≤0.2,0≤y B ≤0.1. The color coordinates of the green light unit 12 are as follows: G(x G ,y G ) point, its green light purity>0.7, where 0.1≤x G ≤0.2,0.65≤y G ≤0.75. The color coordinates of the red light unit 13 are as follows: R(x R ,y R ) point, its red light purity>0.9, where 0.63≤x R ≤0.7, 0.3≤y R ≤0.35. The RGB three points enclose the color gamut of the color modulatable by the light emitting device 10. In the present invention, the NTSC of the light emitting device 10 is greater than 105%.

[0015] In other embodiments of the present invention, the blue light unit 11, the green light unit 12, the red light unit 13 and the warm white light unit 14 can cooperate to emit mixed white light close to the black body radiation line, and are used to adjust the color temperature of the mixed white light. In particular, in order to make the mixed white light closer to the black body radiation line in the range of 1800K to 6500K, for example, SDCM<4. The color coordinates of the warm white light unit 14 are located at the point W(x W ,y W ), where 0.4≤xW ≤0.5,0.4≤y W ≤0.5, and the color coordinate W(x W ,y W ) is located above the Planckian locus, so that the area enclosed by the blue light unit 11, the green light unit 12, the red light unit 13 and the warm white light unit 14 can cover the range of 1800K to 2700K of the Planckian curve, and the color coordinates of the warm white light unit 14 and the red light unit 13 are placed on both sides of the Planckian locus. The light-emitting device 10 can achieve low color temperature mixed white light by coordinating the light intensity ratio between the red light unit 13 and the warm white light unit 14. The luminous intensity of the above four light-emitting units can be adjusted independently, so as to facilitate the adjustment of the color or color temperature of the final output light of the light-emitting device 10. In summary, the light-emitting device 10 provided in the embodiment of the utility model reduces the number of light sources by setting four light-emitting units, and can still achieve the technical effect of adjusting the color of the lamp and the color temperature of white light.

[0016] In detail, in order to more easily achieve high-quality mixed white light, the blue light unit 11 of the utility model preferably has a blue light main wavelength of 455nm~465nm, and can generally include a first blue light chip with a main wavelength greater than or equal to 455nm and less than or equal to 465nm, which can be selectively covered with light-transmitting glue to protect the first blue light chip; the green light unit 12 preferably has a green light main wavelength of 515nm~530nm, and can generally include a first green light chip with a main wavelength greater than or equal to 515nm and less than or equal to 530nm, which can be selectively covered with light-transmitting glue to protect the first green light chip. Generally speaking, if it is simply to achieve a higher color gamut, the red light chip will be used to participate in color adjustment. However, the red light unit 13 of the utility model needs to participate in the adjustment of mixed white light, especially mixed white light with a low color temperature such as 1800K. In order to make the mixed white light more in line with the black body radiation, the red light unit 13 of the utility model preferably has a main wavelength of red light of 615nm to 630nm, which can include a blue light LED (or a second blue light chip) and a red powder that can convert blue light into red light. A variety of solutions can achieve a red light main wavelength of 615nm to 630nm, which will be further described later.

[0017] As is known to all, blue light, green light, and red light with high color purity usually cannot produce white light with a relatively continuous spectrum and close to the black body radiation line. In order to make the final mixed white light closer to the black body radiation line in the range of 1800K to 6500K, the warm white light unit 14 needs to have a certain luminous intensity in the visible light range and supplement the light emitted by the blue light unit 11, the green light unit 12, and the red light unit 13. After a large number of experimental studies, when the main wavelength of the warm white light unit 14 is greater than or equal to 570nm and less than or equal to 600nm, it can be matched with blue light, green light, and red light with high color purity. Through different current configurations, mixed white light with a spectrum that fits the black body radiation line and is relatively continuous can be achieved, and its color tolerance can be controlled within 5 steps. And it can be achieved in the range of 1800K to 6500K, the mixed white light SDCM <4, and CRI>90.

[0018] Specifically, the spectral distribution of the warm white light unit 14 may be, for example Figure 3 As shown. The warm white light unit 14 can, for example, excite the fluorescent material through a blue light LED to emit orange-yellow light with a peak (Wp) wavelength of 570nm to 600nm and a half-wave width of 90nm to 140nm. Among them, the blue light LED (i.e., the third blue light chip) used in the warm white light unit 14 preferably has a main wavelength of 445nm to 460nm, and the fluorescent material used includes, for example, yellow-green powder with a main emission band in the range of 530nm to 550nm, and red powder with a main emission band in the range of 600nm to 625nm. In the spectrum of the warm white light unit 14, it has a blue light peak Wp in the blue light band. B , the peak value of blue light Wp B The intensity ratio of the peak Wp of the warm white light (i.e., the normalized intensity of the peak in the blue light band) is between 10% and 30%, so that the light emitting device 10 is more convenient to adjust the white light at a low color temperature. Because in the process of adjusting the color temperature of the mixed white light, the adjustment of the red light part depends more on the red light unit 13, so the warm white light unit 14 preferably has a CRI (Ra) ≤ 75. In this way, the light emitting device 10 can achieve mixed white light with a low color temperature close to the black body radiation by coordinating the light intensity ratio between the red light unit 13 and the warm white light unit 14.

[0019] In addition, if Figure 3In the different embodiments of warm white light with a main wavelength between 570nm and 600nm shown in series 1 to series 7, when the light intensity of the warm white light unit 14 at a wavelength of 530nm is greater than or equal to 25% and less than or equal to 75% compared to the peak wavelength intensity, the warm white light unit 14 can provide more green light spectrum intensity, and when adjusting the mixed white light, the luminous intensity of the green light unit 12 with higher purity can be reduced, so that high-quality mixed white light can be achieved more stably and easily. Under the design of this spectral distribution, by adjusting the luminous intensity of different light-emitting units, the light-emitting device 10 can provide mixed white light with a color rendering index of more than 90 in the range of 1800K to 6500K. Furthermore, when the relative luminous intensity of the warm white light unit 14 at a wavelength of 530nm is set to be greater than or equal to 45% and less than or equal to 55%, the light-emitting device 10 can provide mixed white light with a color rendering index CRI ≥ 95 in the range of 2200K to 6500K more stably and easily.

[0020] As mentioned above, the red light unit 13 preferably has a dominant wavelength of 615nm to 630nm, and there can be a variety of combinations of blue light LEDs and different red powders. For example, in some embodiments, the red light unit 13 may include a blue light LED with a dominant wavelength of 445nm to 460nm and a combination of narrow-wavelength nitride red powder and fluoride red powder. The narrow-wavelength nitride red powder here refers to a red powder with a half-wave width between 60nm and 70nm, such as (SrCa)AlSiN3, i.e., SCASN. The fluoride red powder may be Mn 4+ Activated K2SiF6 is KSF, K2GeF6 is KGF, and K2TiF6 is KTF. The peak wavelength of red light emitted by the narrow-wavelength nitride red powder and fluoride red powder excited by the blue light LED is 632±2nm. When the half-wave width is less than 10nm, the main wavelength of the red light can be achieved to fall between 615nm and 630nm, thereby further achieving the goal of the utility model. In this embodiment, the fluoride red powder has a high wavelength conversion efficiency and can improve the brightness of the red light unit, but the fluoride red powder has poor absorption of blue light. The use of fluoride alone cannot achieve high-purity red light, which is not conducive to the color adjustment of the light-emitting device 10, and the excess blue light that cannot be absorbed will also affect the freedom of adjustment of the blue light part in the process of mixing white light to adjust the color temperature. Therefore, the narrow-wavelength nitride red powder is used in conjunction with the absorption of excess blue light. When the normalized intensity of the blue light part is <0.3, the purity of the red light unit 13 can be greater than 0.9.

[0021] In other embodiments, the red light unit 13' may also include a blue light LED with a main wavelength of 445nm to 460nm and a wide-wavelength nitride red powder. The wide-wavelength nitride red powder here refers to a red powder with a half-wave width between 70nm and 90nm, such as Eu 2+Activated (SrCa)AlSiN3, i.e. SCASN, CaAlSiN3, i.e. CASN, (BaSr)2Si5N8, i.e. BSSN, can also emit red light with a purity greater than 0.9 when excited by a blue LED. When the peak wavelength is 634±5nm and the half-wave width is 70nm-90nm, the main wavelength of the red light can be within the range of 615nm-630nm, thereby further achieving the goal of the utility model. It should be noted that the narrow-wave SCASN and the wide-wave SCASN mentioned here are nitride red powders with the same elemental composition, and the difference is that the narrow-wave SCASN has a relatively higher content of Sr.

[0022] Please refer to Figure 4A and Figure 5A , Figure 4A and Figure 5A The utility model is a schematic diagram of the spectrum distribution of high-quality mixed white light with a CRI greater than 90 at different color temperatures within the range of 1800K to 6500K by configuring different red light units 13 / 13' with blue light units 11, green light units 12, and warm white light units 14 through current. The utility model designs four different light-emitting units and can achieve the effect of adjusting both color and color temperature and having a high display index through a variety of current configurations. There are multiple schemes for the proportion of current distribution, such as Figure 4B and Figure 5B This is a schematic diagram of the spectrum distribution of mixed white light with CRI ≥ 95 at different color temperatures within the range of 2200K to 6500K by configuring different currents of different red light units 13 / 13 ′ and blue light units 11 , green light units 12 , and warm white light units 14 of the present invention.

[0023] Combine the following Figure 3 and Figure 4A , Figure 4B When the red light unit 13 uses a blue light LED to excite narrow-wavelength nitride red powder and fluoride red powder, the light-emitting device 10 can emit high-quality mixed white light with different color temperatures by configuring the currents of the four different light-emitting units.

[0024] Table 1: A color temperature adjustment scheme for red light unit 13 using blue light LED to excite narrow-wavelength nitride red powder and fluoride red powder to achieve CRI>90

[0025] CCT W R(KSF) G B x y CRI R9 1800 35.5％ 64.5％ 0.0％ 0.0％ 0.5500 0.3998 92.4 66.2 2200 51.5％ 46.6％ 1.0％ 0.9％ 0.5052 0.4153 93.2 57.6 2700 56.8％ 34.8％ 4.9％ 3.5％ 0.4595 0.4105 92.8 58.8 3000 58.5％ 28.6％ 7.5％ 5.4％ 0.4347 0.4030 92.8 58.4 3500 58.5％ 23.0％ 10.9％ 7.6％ 0.4081 0.3919 92.9 58.5 4000 56.8％ 18.3％ 14.9％ 10.1％ 0.3818 0.3795 92.9 58.0 5000 52.4％ 12.6％ 20.5％ 14.5％ 0.3440 0.3545 93.2 59.3 5700 51.5％ 9.8％ 21.7％ 17.0％ 0.3279 0.3403 93.2 59.4 6500 48.5％ 7.7％ 24.5％ 19.3％ 0.3111 0.3263 93.3 60.4

[0026] Table 2: Another color temperature adjustment scheme for red light unit 13 to achieve CRI ≥ 95 by using blue light LED to excite narrow-wavelength nitride red powder and fluoride red powder

[0027]

[0028]

[0029] Referring to Table 1 and Table 2, the light-emitting device 10 provided in the embodiment of the utility model can adjust the color temperature and color rendering index of the mixed white light by setting the current ratio of each light-emitting unit. Among them, the CCT column in Table 1 and Table 2 is the color temperature of the mixed white light close to the black body radiation, and the W, R, G, and B columns represent the current proportions of the warm white light unit 14, the red light unit 13, the green light unit 12, and the blue light unit 11 in order (calculated with the total current as 100%); x and y represent the color coordinates of the mixed white light in the CIE color space, CRI is CRI (Ra), and R9 is CRI (R9). It can be determined from Table 1 and Table 2 that the light-emitting device 10 provided in the embodiment of the utility model can provide white light with a color temperature of 1800K to 6500K, and the color rendering index CRI (Ra) of the white light is above 90, and R9 can be maintained above 50. Furthermore, by adjusting the current proportions of the four light-emitting units, the white light emitted by the light-emitting device 10 is within the color temperature range of 2200K to 6500K, and its color rendering index CRI (Ra) can be higher than 95, and R9 can be higher than 70.

[0030] Combine the following Figure 3 and Figure 5A , Figure 5B When the red light unit 13' uses a blue light LED to excite narrow-wavelength nitride red powder and fluoride red powder, the light-emitting device 10 can emit high-quality mixed white light with different color temperatures by configuring the currents (current proportions) of the four different light-emitting units.

[0031] Table 3: A color temperature adjustment scheme for red light unit 13' using blue light LED to excite broadband nitride red powder to achieve CRI>90

[0032]

[0033]

[0034] Table 4: Another color temperature adjustment scheme for red light unit 13' using blue light LED to excite broadband nitride red powder to achieve CRI ≥ 95

[0035] CCT W R G B x y CRI R9 2200 42.7％ 52.0％ 4.5％ 0.9％ 0.5016 0.4163 95.9 71.1 2700 47.7％ 40.5％ 8.3％ 3.4％ 0.4577 0.4101 95.9 73.8 3000 48.9％ 34.9％ 11.1％ 5.1％ 0.4340 0.4036 95.9 75.2 3500 49.2％ 29.2％ 14.3％ 7.2％ 0.4078 0.3921 95.8 77.1 4000 48.5％ 24.3％ 17.4％ 9.8％ 0.3818 0.3800 95.2 78.0 5000 44.0％ 19.1％ 23.2％ 13.8％ 0.3451 0.3557 95.6 85.0 5700 41.0％ 17.8％ 25.3％ 15.9％ 0.3289 0.3421 95.4 93.9 6500 38.6％ 15.5％ 27.9％ 18.1％ 0.3123 0.3286 95.0 95.6

[0036] As shown in Tables 3 and 4, when the light-emitting device 10 selects broadband nitride as the main luminescent material of red light, the color rendering index CRI (Ra) of the white light generated by the light-emitting device 10 can still exceed 90, and its CRI (R9) is higher than 50. By properly adjusting the current proportion of each light-emitting unit, when the color temperature of the white light of the light-emitting device 10 is between 2200K and 6500K as shown in Table 4, the CRI (Ra) of the white light can exceed 95, and its CRI (R9) is also at a high level of more than 70.

[0037] Combination Figures 3 to 5B , and refer to Tables 1 to 4. The utility model can achieve the effect of adjusting both color and color temperature and having a high display index by designing four different light-emitting units through a variety of current configurations. The current proportions in the above table are not used to limit the technical scope of the utility model. In order to more clearly define the current configuration of the mixed white light solution that can achieve a high display index, a color K value is defined for the mixed white light emitted by the light-emitting device 10. The K value represents the ratio of the maximum light intensity at 480nm to 540nm to the minimum light intensity at 540nm to 580nm. Expressed as a formula:

[0038]

[0039] Wherein, the λ1 is greater than or equal to 480nm and less than or equal to 540nm, the λ2 is greater than or equal to 540nm and less than or equal to 580nm, and I is the luminous intensity corresponding to light of different wavelengths. When the K value is within the preset range described in Table 5 through current configuration, the color rendering index of the mixed white light at the corresponding color temperature in the range of 1800K to 6500K can be greater than 90.

[0040] Table 5. K value range when CRI is greater than or equal to 90 / 95 at different color temperatures

[0041] CCT Kmin Kmax 1800 1.0 1.26 2200 1.0 1.18 2700 1.0 1.39 3000 1.0 1.46 3500 1.03 1.57 4000 1.11 1.71 5000 1.23 1.99 5700 1.27 2.08 6500 1.38 2.20

[0042] Furthermore, when the K value is between the maximum value Kmax and the minimum value Kmin as shown in Table 5 above, the color rendering index of the mixed white light generated by the light-emitting device 10 at the corresponding color temperature in the range of 2200K to 6500K can reach 95 or above.

[0043] In summary, the utility model provides a light-emitting device, including a blue light unit that emits blue light, a green light unit that emits green light, a red light unit that emits red light, and a warm white light unit that emits warm white light, which can be independently controlled to achieve the dimming function of color light and white light the same as traditional RGBCW. In particular, the main wavelength of warm white light is limited to 570nm~600nm, or the color coordinates W(x W ,y W ) is located above the Planck locus and satisfies 0.4≤x W ≤0.5,0.4≤y W When ≤0.5, the light-emitting device can emit mixed white light that is closer to blackbody radiation during the process of adjusting the color temperature.

[0044] Furthermore, in order to more easily achieve high-quality mixed white light, the dominant wavelength of blue light is preferably 455nm-465nm, the dominant wavelength of green light is preferably 515nm-530nm, and the dominant wavelength of red light is preferably 615nm-630nm.

[0045] Furthermore, in order to more easily achieve a color rendering index of greater than 90 for mixed white light in the range of 1800K to 6500K, the normalized intensity of the warm white light at a wavelength of 530nm is preferably between 25% and 75%. When the normalized intensity of the selected warm white light at a wavelength of 530nm is controlled within the range of 45% to 55%, the light-emitting device can more stably and easily provide mixed white light with a color rendering index CRI ≥ 95 in the range of 2200K to 6500K.

[0046] In addition, it can be understood that the aforementioned embodiments are merely illustrative descriptions of the present invention. On the premise that the technical features do not conflict, are not contradictory, and do not violate the purpose of the present invention, the technical solutions of the various embodiments can be arbitrarily combined and used in combination.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the utility model.

Claims

1. A light emitting device, characterized in that: include: The color coordinate is B(x B ,y B ) of blue light units, where 0.1≤x B ≤0.2,0≤y B ≤0.1; The color coordinates are G(x G ,y G ) of green light units, where 0.1≤x G ≤0.2,0.65≤y G ≤0.75; The color coordinates are R(x R ,y R ) of red light units, where 0.63≤x R ≤0.7, 0.3≤y R ≤0.35; The color coordinates are W(x W ,y W ) of warm white light units, where 0.4≤x W ≤0.5, 0.4≤y W ≤0.5, and the color coordinates W(x W ,y W ) is located above the Planck locus.

2. The light emitting device according to claim 1, characterized in that: The light emitted by the warm white light unit has a peak wavelength of 570nm to 600nm and a half-wave width of 90nm to 140nm.

3. The light emitting device according to claim 1, characterized in that: The normalized intensity of the light emitted by the warm white light unit in the blue light band is 10% to 30%.

4. The light emitting device according to claim 1, characterized in that: The normalized intensity of the light emitted by the warm white light unit at a wavelength of 530 nm is 25% to 75%.

5. The light emitting device according to claim 1, characterized in that: The main wavelength of the light emitted by the warm white light unit is 570nm-600nm.

6. The light emitting device according to claim 1, characterized in that: The main wavelength of the light emitted by the blue light unit is 455nm-465nm; the main wavelength of the light emitted by the green light unit is 515nm-530nm; the main wavelength of the light emitted by the red light unit is 615nm-630nm.

7. The light emitting device according to claim 6, characterized in that: The red light unit includes a blue light LED and a wide-wavelength nitride red powder. The blue light LED excites the wide-wavelength nitride red powder to emit the red light. The peak wavelength of the red light is 634±5nm, and the half-wave width is 70nm-90nm.

8. The light emitting device according to claim 6, characterized in that: The red light unit includes a blue light LED, a narrow-wavelength nitride red powder and a fluoride red powder. The blue light LED excites the narrow-wavelength nitride red powder and the fluoride red powder to emit the red light. The peak wavelength of the red light is 632±2nm, and the half-wave width is less than or equal to 10nm.

9. The light emitting device according to claim 1, characterized in that: The blue light unit, the green light unit, the red light unit and the warm white light unit are electrically independent and can cooperate to emit mixed white light and are used to adjust the color temperature of the mixed white light.

10. A light emitting device, characterized in that: comprising the blue light unit, the green light unit, the red light unit and the warm white light unit as claimed in claim 9; The mixed white light has a color rendering index greater than 90 within a color temperature adjustment range of 1800K to 6500K; or, the mixed white light has a color rendering index greater than or equal to 95 within a color temperature adjustment range of 2200K to 6500K.

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