Light emitting device

Abstract

The light-emitting device provided by the embodiment of the invention comprises an RGB light-emitting assembly and a spectrum supplementing unit, the RGB light-emitting component comprises a blue light unit, a green light unit and a red light unit of which the color purity is greater than 0.7; the RGB light-emitting assembly is used for providing color light and participating in dimming of mixed white light; the spectrum supplementing unit is used for emitting warm white light to supplement light emitted by the RGB assembly so as to emit mixed white light with the color tolerance smaller than 5SDCM; the CRI (Ra) of the spectrum supplementing unit is smaller than 75, so that the light-emitting device can emit mixed white light close to blackbody radiation within the range of 1800-2700 K through the matching of the light intensity proportion between the red light unit and the spectrum supplementing unit. The light-emitting device can realize that mixed white light is closer to blackbody radiation rays in a range of 1800K-6500K.

Description

Technical Field

[0001] This invention relates to the field of lighting technology, and more particularly to a light-emitting device. Background Technology

[0002] Currently, some smart lighting fixtures exist on the market. These fixtures typically have multiple light-emitting units of different colors, such as red, green, and blue light-emitting units and cool and warm white light-emitting units. These smart lighting fixtures are generally called RGBCW smart lights. RGBCW smart lights can handle both colored and white light dimming. The red, green, and blue light-emitting units (RGB units) are generally responsible for color dimming, while the cool and warm white light-emitting units (CW units) are generally responsible for adjusting the color temperature of the mixed white light. With the development of LED technology, the applicant previously introduced a more compact smart lighting device in patent application CN202310698509.7. This device consists of four different light-emitting units, yet achieves the same colored and white light dimming functions as traditional RGBCW lights. Based on this, the applicant has further improved the smart lighting device, enhancing the quality of the white light. Summary of the Invention

[0003] To address the technical challenge of balancing the dimming of colored and white light in compact lighting fixtures while simultaneously producing higher-quality white light, this invention provides a light-emitting device. The light-emitting device includes an RGB light-emitting component and a spectral supplement unit. The RGB light-emitting component comprises a blue light unit, a green light unit, and a red light unit, each with a color purity greater than 0.7. The RGB light-emitting component provides colored light and participates in the dimming of the mixed white light. The spectral supplement unit emits warm white light to supplement the light emitted by the RGB component, resulting in mixed white light with a color tolerance of less than 5 SDCM. The CRI (Ra) of the spectral supplement unit is less than 75, enabling the light-emitting device to emit mixed white light close to blackbody radiation in the range of 1800K to 2700K through the coordination of the light intensity ratio between the red light unit and the spectral supplement unit.

[0004] The technical solution provided by this invention realizes a compact intelligent light-emitting device by setting four light-emitting units. It achieves the technical effect of different colors and different color temperatures of white light by using fewer types of light sources. By limiting the purity of each light-emitting unit of the RGB light-emitting component and the color rendering index of the spectral supplement unit, the white light emitted by the light-emitting device at various color temperatures can be made close to the blackbody radiation line (i.e., the color tolerance is less than 5 SDCM) and have a good CRI (color rendering index) during the adjustment of different color temperatures by adjusting the current ratio of the four independently controlled light-emitting units. Attached Figure Description

[0005] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0006] Figure 1 This is a schematic diagram of the structure of a light-emitting device provided in an embodiment of the present invention.

[0007] Figure 2 for Figure 1 A schematic diagram of one color gamut of the light-emitting device shown in the CIE color space.

[0008] Figure 3 for Figure 1 The diagram shows the spectral distribution of the warm white light unit.

[0009] Figure 4A , Figure 4B , Figure 5A , Figure 5B for Figure 1 The diagram shows the spectral distribution of mixed white light emitted by the light-emitting device in different embodiments. Detailed Implementation

[0010] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0011] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification and claims of this invention are intended to cover non-exclusive inclusion; the definition of numerical ranges is understood to include both extreme values ​​unless explicitly stated otherwise. 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.

[0012] See Figure 1 and Figure 2 An embodiment of the present invention provides a light-emitting device 10. The light-emitting device 10 includes, as shown in the figure below. Figure 1The diagram shows a blue light unit 11, a green light unit 12, a red light unit 13, and a warm white light unit 14. The blue light unit 11 emits blue light, the green light unit 12 emits green light, the red light unit 13 emits red light, and the warm white light unit 14 emits 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, green light unit 12, and red light unit 13 as corresponding blue light sources, green light sources, and red light sources, respectively. In the CIE color space (e.g., CIE 1931 color space), the color coordinates of the blue light unit 11 are as follows: B(x... B ,y B As shown at point ), its blue light purity is >0.96, where 0.1 ≤ x B ≤0.2, 0≤y B ≤0.1. The color coordinates of green light unit 12 are as follows: G(x G ,y G As shown at point ), its green light purity is >0.7, where 0.1 ≤ x. G ≤0.2, 0.65≤y G ≤0.75. The color coordinates of red light unit 13 are as follows: R(x R ,y R As shown at point ), its red light purity is >0.9, where 0.63 ≤ x. R ≤0.7, 0.3≤y R ≤0.35. The color gamut of the light-emitting device 10 can be modulated by the RGB three points. In this invention, the NTSC of the light-emitting device 10 is >105%.

[0013] In other embodiments of the present invention, the blue light unit 11, green light unit 12, red light unit 13, and warm white light unit 14 can cooperate to emit mixed white light close to the blackbody radiation line, and are used to adjust the color temperature of the mixed white light. Specifically, to make the mixed white light closer to the blackbody radiation line in the range of 1800K~6500K, for example, SDCM < 4, the color coordinates of the warm white light unit 14 are located at point W(x... W ,y W ), where 0.4≤x W ≤0.5, 0.4≤y W ≤0.5, and the chromaticity coordinates W(x) of warm white light unit 14 W ,y WLocated above the Planck trajectory, the area enclosed by the blue light unit 11, green light unit 12, red light unit 13, and warm white light unit 14 covers the Planck curve range of 1800K to 2700K. Furthermore, the color coordinates of the warm white light unit 14 and the red light unit 13 are positioned on opposite sides of the Planck trajectory. 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 four light-emitting units can be adjusted independently, making it easier to adjust 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 this embodiment of the invention achieves the technical effect of reducing the number of light sources while still achieving color and white light color temperature adjustment by setting four light-emitting units.

[0014] In detail, to more easily achieve high-quality mixed white light, the blue light unit 11 of this invention preferably has a blue light dominant wavelength of 455nm~465nm, and it typically includes a first blue light chip with a dominant wavelength greater than or equal to 455nm and less than or equal to 465nm, which may be selectively covered with a light-transmitting adhesive to protect the first blue light chip; the green light unit 12 preferably has a green light dominant wavelength of 515nm~530nm, and it typically includes a first green light chip with a dominant wavelength greater than or equal to 515nm and less than or equal to 530nm, which may be selectively covered with a light-transmitting adhesive to protect the first green light chip. Generally speaking, if the sole purpose is to achieve a higher color gamut, a red light chip would be preferentially used to participate in color adjustment, but the red light unit 13 of this invention needs to participate in the adjustment of mixed white light, especially for low color temperatures such as 1800K mixed white light. In order for the mixed white light to better conform to the blackbody radiation line, the red light unit 13 of this invention preferably has a red light dominant wavelength of 615nm~630nm, which may include a blue LED (or a second blue light chip) and red phosphor that can convert blue light into red light. Several methods can achieve a red light main wavelength of 615nm~630nm, which will be described in more detail later.

[0015] As is well known, high-purity blue, green, and red light typically cannot produce white light with a relatively continuous spectrum that closely approximates blackbody radiation. This invention aims to achieve a final mixed white light that more closely approximates blackbody radiation within the 1800K~6500K range. The warm white light unit 14 needs to possess a certain luminous intensity within the visible light range and supplement the light emitted by the blue light unit 11, green light unit 12, and red light unit 13. Extensive experimental research has shown that when the dominant 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 combined with high-purity blue, green, and red light. Through different current configurations, a mixed white light that closely approximates blackbody radiation and has a relatively continuous spectrum can be achieved, with color tolerance controllable within a 5-step range. Furthermore, within the 1800K~6500K range, the mixed white light SDCM < 4 and CRI > 90 can be achieved.

[0016] Specifically, the spectral distribution of the aforementioned warm white light unit 14 can be, for example... Figure 3 As shown. The warm white light unit 14 can, for example, be excited by a blue LED to emit orange-yellow light with a peak wavelength (Wp) of 570 nm to 600 nm and a half-width of 90 nm to 140 nm. The blue LED (i.e., the third blue LED chip) used in the warm white light unit 14 preferably has a main wavelength of 445 nm to 460 nm, and the fluorescent material used includes, for example, yellow-green phosphor with a main emission band in the range of 530 nm to 550 nm, and red phosphor with a main emission band in the range of 600 nm to 625 nm. 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 Wp of the blue light 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%, making it easier for the light-emitting device 10 to adjust the white light at low color temperatures. Because the adjustment of the red light portion during the mixed white light color temperature adjustment process relies more on the red light unit 13, 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 blackbody radiation by coordinating the light intensity ratio between the red light unit 13 and the warm white light unit 14.

[0017] In addition, such as Figure 3 The different embodiments of warm white light with a main wavelength between 570nm and 600nm shown in Series 1 to Series 7, where the light intensity emitted by 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% of the peak wavelength intensity, can provide more intensity of the green light spectrum. When adjusting the mixed white light, the luminous intensity of the higher-purity green light unit 12 can be reduced, thus achieving high-quality mixed white light more stably and easily. Under this spectral distribution design, 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 (CRI) of 90 or higher 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 more stably and easily provide mixed white light with a CRI ≥ 95 in the range of 2200K to 6500K.

[0018] As mentioned earlier, the preferred red light unit 13 has a dominant wavelength of 615nm to 630nm, and can be configured with various combinations of blue LEDs and different red phosphors. For example, in some embodiments, the red light unit 13 may include a combination of a blue LED with a dominant wavelength of 445nm to 460nm and narrow-wavelength nitride red phosphors and fluoride red phosphors. Here, the narrow-wavelength nitride red phosphor refers to a red phosphor with a half-width between 60nm and 70nm, such as (SrCa)AlSiN3 (SCASN), and the fluoride red phosphor can be Mn. 4+ Activated K2SiF6 is KSF, K2GeF6 is KGF, and K2TiF6 is KTF. When the peak wavelength of the red light emitted by the narrow-wavelength nitride red powder and fluoride red powder excited by the blue LED is 632±2nm and the half-width is less than 10nm, the main wavelength of the red light can fall within 615nm~630nm, thereby further achieving the objective of the present invention. In this embodiment, the fluoride red powder has a high wavelength conversion efficiency, which can improve the brightness of the red light unit. However, the fluoride red powder has poor absorption of blue light. Using fluoride alone cannot achieve high purity red light, which is not conducive to the color adjustment of the light-emitting device 10. Moreover, the excess blue light that cannot be absorbed will also affect the freedom of adjustment of the blue light part during the white light color temperature adjustment process. Therefore, the narrow-wavelength nitride red powder is used in conjunction to absorb 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.

[0019] In other embodiments, the red light unit 13' may further include a blue LED with a main wavelength of 445nm~460nm and a broadband red nitride phosphor. Here, the broadband red nitride phosphor refers to a red phosphor with a half-wavelength between 70nm and 90nm, such as Eu. 2+ Activated (SrCa)AlSiN3 (SCASN), CaAlSiN3 (CASN), and (BaSr)2Si5N8 (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-width is 70nm~90nm, the dominant wavelength of the red light falls within the range of 615nm~630nm, thus further achieving the objective of this invention. It should be noted that the narrow-wavelength SCASN and wide-wavelength SCASN mentioned here are nitride red powders with the same elemental composition; the difference lies in the relatively higher Sr content in the narrow-wavelength SCASN.

[0020] Please refer to Figure 4A and Figure 5A , Figure 4A and Figure 5AThis diagram illustrates the spectral distribution of high-quality mixed white light with a CRI greater than 90 at different color temperatures within the range of 1800K to 6500K, achieved 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 configuration. This invention, by designing four different light-emitting units that can be configured with various currents, achieves the effect of adjusting both color and color temperature while maintaining a high display index. The current allocation can be implemented in various ways, for example... Figure 4B and Figure 5B This is a schematic diagram illustrating the spectral distribution of mixed white light with CRI≥95 at different color temperatures within the range of 2200K~6500K, achieved by configuring different red light units 13 / 13' with blue light units 11, green light units 12, and warm white light units 14 using different current configurations.

[0021] The following is combined Figure 3 and Figure 4A , Figure 4B When the red light unit 13 uses a blue 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 current of the four different light-emitting units.

[0022] Table 1. Red light unit 13 uses blue LED to excite narrow-wavelength nitride red powder and fluoride red powder to achieve CRI>90. A color temperature adjustment scheme

[0023] Table 2. Red light unit 13 uses blue LED to excite narrow-wavelength nitride red powder and fluoride red powder to achieve CRI≥95. Another color temperature adjustment scheme

[0024] Referring to Tables 1 and 2, the light-emitting device 10 provided in this embodiment of the invention can adjust the color temperature and color rendering index of the mixed white light by setting the current ratio of each light-emitting unit. In Tables 1 and 2, the CCT column represents the color temperature of the mixed white light close to the blackbody radiation line; the W, R, G, and B columns represent the current ratios of the warm white light unit 14, red light unit 13, green light unit 12, and blue light unit 11, respectively (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). Tables 1 and 2 confirm that the light-emitting device 10 provided in this embodiment of the invention can provide white light with a color temperature between 1800K and 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 ratio of the four light-emitting units, the white light emitted by the light-emitting device 10 can have a color rendering index (CRI) higher than 95 and an R9 higher than 70 within a color temperature range of 2200K to 6500K.

[0025] The following is combined Figure 3 and Figure 5A , Figure 5B When the red light unit 13' uses a blue 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 current (current ratio) of the four different light-emitting units.

[0026] Table 3. A color temperature adjustment scheme for achieving CRI>90 using blue LED to excite broadband nitride red phosphor in red light unit 13'.

[0027] Table 4. Another color temperature adjustment scheme for red light unit 13' using blue LED to excite broadband nitride red phosphor to achieve CRI≥95.

[0028] As shown in Tables 3 and 4, when the light-emitting device 10 selects broadband nitride as the main light-emitting material for 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 appropriately adjusting the current ratio of each light-emitting unit, when the white light color temperature 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 relatively high level of above 70.

[0029] Combination Figures 3 to 5BReferring to Tables 1 to 4, this invention, by designing four different light-emitting units, can achieve a high display index while adjusting both color and color temperature through various current configurations. The current percentages in the tables are not intended to limit the technical scope of this invention. To further clarify the current configuration for achieving a high display index mixed white light scheme, a color K value is defined for the mixed white light emitted by the light-emitting device 10. This K value represents the ratio of the maximum light intensity in the 480nm~540nm range to the minimum light intensity in the 540nm~580nm range. This can be expressed by the formula:

[0030] Among them, the Greater than or equal to 480nm and less than or equal to 540nm, the The wavelength I is greater than or equal to 540 nm and less than or equal to 580 nm, where I represents the luminous intensity corresponding to different wavelengths of light. When the K value is configured to be 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~6500K can be greater than 90.

[0031] Table 5. Range of K values ​​when CRI is greater than or equal to 90 / 95 at different color temperatures.

[0032] 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 can reach 95 or above at the corresponding color temperature in the range of 2200K~6500K.

[0033] In summary, this invention provides a light-emitting device comprising independently controllable blue light emitting unit, green light emitting unit, red light emitting unit, and warm white light emitting unit, achieving the same dimming function for colored and white light as conventional RGBCW. Specifically, the dominant wavelength of the warm white light is defined as 570nm~600nm, or the chromaticity coordinates W(x) of the warm white light are defined as follows: W ,y W The value lies above the Planck locus and satisfies 0.4 ≤ x. W ≤0.5, 0.4≤y W When the value is ≤0.5, the light-emitting device can emit mixed white light that is closer to the blackbody radiation during the color temperature adjustment process.

[0034] 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.

[0035] Furthermore, in order to more easily achieve a color rendering index (CRI) 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 CRI ≥ 95 in the range of 2200K to 6500K.

[0036] Furthermore, it is understood that the foregoing embodiments are merely illustrative examples of the present invention. Provided that the technical features do not conflict, are fixed and do not contradict the purpose of the present invention, the technical solutions of the various embodiments can be arbitrarily combined and used.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A light-emitting device, characterized in that, include: RGB light-emitting components and spectral supplementation units; The RGB light-emitting component includes blue light units, green light units, and red light units, each with a color purity greater than 0.7; the RGB light-emitting component is used to provide colored light and participate in dimming for mixing white light; The spectral supplement unit is used to emit warm white light to supplement the light emitted by the RGB component to emit mixed white light with a color tolerance of less than 5 SDCM; the CRI (Ra) of the spectral supplement unit is less than 75, so that the light-emitting device can emit mixed white light close to the blackbody radiation in the range of 1800K~2700K by coordinating the light intensity ratio between the red light unit and the spectral supplement unit.

2. The light-emitting device according to claim 1, characterized in that, The peak wavelength of the warm white light is between 570nm and 600nm, and the half-width is between 90nm and 140nm.

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

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

5. The light-emitting device according to claim 1, characterized in that, The warm white light has color coordinates W(x) W ,y W ), where 0.4≤x W ≤0.5, 0.4≤y W ≤0.5, and the chromaticity coordinates W(x) of the warm white light W ,y W The blue light unit is located above the Planck trajectory; and / or, the chromaticity coordinates B(x) of the blue light unit are... B ,y B The following condition must be met: 0.1 ≤ x B ≤0.2, 0≤y B ≤0.1; and / or, the color coordinates G(x) of the green light unit G ,y G The following condition must be met: 0.1 ≤ x G ≤0.2, 0.65≤y G ≤0.75; and / or, the chromaticity coordinates of the red light unit are as follows: R(x R ,y R The following condition must be met: 0.63 ≤ x R ≤0.7, 0.3≤y R ≤0.

35.

6. The light-emitting device according to claim 1, characterized in that, The dominant wavelength of the blue light is 455nm~465nm; the dominant wavelength of the green light is 515nm~530nm; and the dominant wavelength of the red light is 615nm~630nm.

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

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

9. The light-emitting device according to claim 1, characterized in that, The purity of the red light emitted by the red light unit is greater than 0.9; and / or, the purity of the blue light emitted by the blue light unit is greater than 0.

96.

10. The light-emitting device according to any one of claims 1 to 9, characterized in that, 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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