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EP-4736236-A1 - LIGHTING ARRANGEMENT

EP4736236A1EP 4736236 A1EP4736236 A1EP 4736236A1EP-4736236-A1

Abstract

A lighting arrangement comprises a respective plurality of first and second light emitting diodes M-LEDs, N-LEDs, arranged on a carrier. Each of the M-LEDs comprising a die having a first surface area SA1 with a largest spatial extent SE1 that is at most 100 micrometers. The N-LEDs are arranged on the carrier, each of the N-LEDs comprising a die having a second surface area SA2 with a largest spatial extent SE2 that is at most 300 micrometers. The M-LEDs emit first light LG1 having a first emission peak wavelength in ultraviolet, violet and/or blue light. The N-LEDs emit second light LG2 having a second emission peak wavelength, in green and/or red light. A ratio defined by SA2/SA1 is equal to or larger than 10. The arrangement light is white light having a correlated color temperature, CCT, in a range 2000-6500K and a color rendering index of at least 80.

Inventors

  • VAN BOMMEL, TIES

Assignees

  • Signify Holding B.V.

Dates

Publication Date
20260506
Application Date
20240624

Claims (14)

  1. 1. A lighting arrangement (100) configured to provide arrangement light, comprising: a carrier (151); a plurality of first light emitting diodes, M-LEDs, (101) arranged on said carrier (151), each of the M-LEDs (101) comprising a die (111) having a first surface area, SAI, wherein the SAI has a largest spatial extent, SEI, that is less than or equal to 100 micrometers; and a plurality of second light emitting diodes, N-LEDs (102) arranged on said carrier (151), each of the N-LEDs (102) comprising a die (112) having a second surface area, SA2, wherein the SA2 has a largest spatial extent, SE2, that is greater than or equal to 300 micrometers; wherein the M-LEDs (101) are configured to emit first light, LG1, having a first emission peak wavelength, I, in a wavelength range 100-380 nm of ultraviolet light, UV, 380-420 nm of violet light, V, and/or 420-490 nm of blue light, B; wherein the N-LEDs (102) are configured to emit second light, LG2, having a second emission peak wavelength, X2, in a wavelength range 510-580 nm of green light, G, and/or 610-680 nm of red light, R; wherein the number of M-LEDs of the plurality of M-LEDs (101) is X; the number of N-LEDs of the plurality of N-LEDs (102) is Y; and X is greater than or equal to 5 times Y, and wherein a ratio, Rl, defined by SA2/SA1 is equal to or larger than 10; and wherein said arrangement light is white light having a correlated color temperature, CCT, in a range from 2000K to 6500K and a color rendering index, CRI, of at least 80.
  2. 2. The lighting arrangement (100) according to claim 1, wherein: SEI is less than or equal to 80 micrometers; SE2 is greater than or equal to 500 micrometers; and Rl is greater than or equal to 20.
  3. 3. The lighting arrangement (100) according to any one of the preceding claims, wherein: the plurality of M-LEDs (101) are homogeneously distributed with a first pitch, Pl, within a first region (161) on the carrier (151); the plurality of N-LEDs (102) are homogeneously distributed with a second pitch, P2, within a second region (162) on the carrier (151), the second region (162) at least partly overlapping the first region (161); and wherein P2 is greater than or equal to 2 times Pl.
  4. 4. The lighting arrangement (100) according to any one of the preceding claims, wherein: each of the M-LEDs (101) has a first length, LI, a first width, Wl, and a first aspect ratio, ARI, defined by LI AVI; each of the N-LEDs (102) has a second length, L2, a second width, W2, and a second aspect ratio, AR2, defined by L2AV2; and AR2 is greater than ARI .
  5. 5. The lighting arrangement (100) according to any one of the preceding claims, wherein: the dies (111) of the M-LEDs (101) are free from any luminescent material; and the N-LEDs (102) comprises a wavelength converter (160), and the dies (112) of the N-LEDs (102) are covered by the wavelength converter (160) comprising a luminescent material.
  6. 6. The lighting arrangement (100) according to any one of the preceding claims, wherein: the M-LEDs (101) comprises (i) one or more B LEDs and (ii) one or more V LEDs and/or one or more UV LEDs.
  7. 7. The lighting arrangement (100) according to any one of the preceding claims, wherein: - the M-LEDs (101) comprises one or more B LEDs; the N-LEDs (102) comprises one or more G LEDs and one or more R LEDs.
  8. 8. The lighting arrangement (100) according to claim 7, wherein: the number of G N-LEDs (102) is greater than or equal to 2 times the number of R N-LEDs (102).
  9. 9. The lighting arrangement (100) according to any one of the preceding claims, wherein the N-LEDs (102) comprises one or more white phosphor converted LEDs.
  10. 10. The lighting arrangement (100) according to any one of the preceding claims, wherein each N-LED (102) is neighbored by at least 2 B M-LEDs (101), preferably at least 3 B M-LEDs (101).
  11. 11. The lighting arrangement (100) according to any one of the preceding claims, wherein each N-LED (102) comprises 4 sides, wherein each side is neighbored by at least 1 B M-LED (lOl).
  12. 12. The lighting arrangement (100) according to any one of the preceding claims, wherein: the plurality of M-LEDs (101) are connected with a respective anode (121) having an anode surface area, ASA1, and a respective cathode (122) having a cathode surface area, CSA1; the plurality of N-LEDs (102) are connected with a respective anode (131) having an anode surface area, ASA2, and a respective cathode (132) having a cathode surface area, CSA2; and ASA2 is greater than or equal to 4 times ASA1 and/or CSA2 is greater than or equal to 4 times CSA1.
  13. 13. The lighting arrangement (100) according to any one of the preceding claims, wherein: the plurality of M-LEDs (101) are connected via a first circuitry (141), preferably the first circuitry (141) comprising a first number of parallel arrangements, PAI; the plurality of N-LEDs (102) are connected via a second circuitry (122), preferably the second circuitry (142) comprising a second number of parallel arrangements, PA2, PAI being greater than PA2, or the second circuitry (142) being a series circuit; and wherein: the lighting arrangement (100) comprises a controller (140) configured to individually control the emission of the first light emitted by said plurality of M-LEDs (101) via the first circuitry (141) and the emission of the second light emitted by said plurality of N-LEDs (102) via the second circuitry (142).
  14. 14. A lamp (200) or a luminaire (300) comprising the lighting arrangement (100) according to any one of the preceding claims.

Description

LIGHTING ARRANGEMENT FIELD OF THE INVENTION The present invention generally relates to lighting arrangements configured to provide white light. More specifically, the present invention is related to a lighting arrangement comprising a plurality of light emitting diodes (LEDs). BACKGROUND OF THE INVENTION A trend in the development of LED lighting is the development of long- lifetime products, for example lighting arrangements that are capable of 100.000 hours operation. Other trends in this development include use of low-cost materials for optical components, decrease of material use in optical components to achieve a lower environmental impact, introduction of biodegradable/bio-based materials for optical components for sustainability. However, these materials are susceptible for blue light (440- 470nm), especially for short wavelength blue light (420-440nm), and more specially for violet light (380-420nm) or even more specially for UV light (<380nm), resulting in an increased risk of browning of the optical components. Since these LEDs may be used in applications such as color point tunable and disinfection lighting, browning of the components is a drawback which has to be addressed. SUMMARY OF THE INVENTION It is of interest to provide a lighting arrangement that overcomes drawbacks of the prior art as discussed above. This and other objects are achieved in a first aspect by providing a lighting arrangement having the features of the appended independent claim. Preferred embodiments are defined in the appended dependent claims. Hence, according to the present invention, there is provided a lighting arrangement configured to provide arrangement light. The lighting arrangement comprises a carrier, a plurality of first light emitting diodes (M-LEDs) arranged on the carrier, each of the M-LEDs comprising a die having a first surface area (SAI), wherein the SAI has a largest spatial extent (SEI) that is less than or equal to 100 micrometers. A plurality of second light emitting diodes (N-LEDs) are arranged on the carrier, each of the N-LEDs comprising a die having a second surface area (SA2), wherein the SA2 has a largest spatial extent (SE2) that is greater than or equal to 300 micrometers. Note that where reference is made to surface area, this relates to the epitaxial or epitaxy (in short ‘epi’) surface area of the die which may only be on the top surface of the die. The M-LEDs are configured to emit first light (LG1) having a first emission peak wavelength (XI) in a wavelength range of ultraviolet light (UV), violet light (V) and/or blue light (B). The N-LEDs are configured to emit second light (LG2) having a second emission peak wavelength (X2), in a wavelength range of green light (G) and/or red light (R). A ratio (Rl) defined by SA2/SA1 is equal to or larger than 10. The arrangement light is white light having a correlated color temperature, CCT, in a range from 2000K to 6500K and a color rendering index (CRI) of at least 80 or at least 85. UV light is light in the wavelength range from lOOnm to 380nm. UVA light is UV light in the wavelength range from 315nm to 380nm. UVB light is UV light in the wavelength range from 280nm to 315nm. UVC light is UV light in the wavelength range from lOOnm to 280nm. Violet light is light in the wavelength range 380nm to 420nm. Violet light in the wavelength range 400nm to 420 nm (i.e. Violet II light) is more safe than violet light in the wavelength range 380nm to 400nm (i.e. Violet I light). Blue light is light in the wavelength range 420nm to 490nm. Royal blue is blue light in the wavelength range 440nm to 465nm. Green light is light in the wavelength range 510nm to 580nm. High efficient and/or high quality green light is green light in the wavelength range 520nm to 565nm i.e. “midrange green light”. Red is light in the wavelength range 600nm to 780nm High efficient and/or high quality red light is red light in the wavelength range 610nm to 660nm i.e. “short wavelength-red light”. Such a lighting arrangement provides an improved performance, especially in terms of less browning, and thereby prolonged lifetime/reliability, of closely arranged components, due to the effect that the local UV/violet/blue LED light intensity is significantly reduced. Especially, polymer components/layers are degraded over time due to high intense UV/violet/blue LED light. Although an effect of reduced light intensity may be considered as being undesired, such reduction is not present for wavelengths that are longer than those of the UV/violet/blue LED light. Because LEDs with a larger die area are relatively cheaper than LEDs with a smaller die area e.g. in terms of assembly costs, it is desired to use these types of LEDs for these other, longer, wavelength ranges. By configuring embodiments of the lighting arrangement such that SEI is less than or equal to 80 micrometers, SE2 is greater than or equal to 500 micrometers and R1 is greater than or equal to 20, it is possible to obtain a