EP-4736238-A1 - LIGHTING ARRANGEMENT

Abstract

A lighting arrangement comprises a respective plurality of first and second light emitting diodes M-LEDs, N-LEDs, arranged on a carrier. The M-LEDs comprise a die having a first surface area SA1 with a largest spatial extent SE1 that is at most (100) micrometers. The N-LEDs comprise 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 having a first emission peak in green light. The N-LEDs are configured to emit second light having a second emission peak in blue light and configured to emit third light having a third emission peak in red light. A ratio defined by SA2/SA1 is equal to or larger than (10) and the arrangement light is white light having a correlated color temperature in a range 2000K to 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 (1)

1. CLAIMS: 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, the first surface area, SAI, having a largest spatial extent, SEI, that is less than or equal to 100 micrometers; 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, the second surface area, SA2, having a largest spatial extent, SE2, that is greater than or equal to 300 micrometers; and wherein: the M-LEDs (101) are configured to emit first light, LG1, having a first emission peak wavelength, I, in a wavelength range of green, G, light; the N-LEDs (102) are configured to emit second light, LG2, having a second emission peak wavelength, X2, in a wavelength range of blue, B, light and configured to emit third light, LG3, having a third emission peak wavelength, X3, in a wavelength range of red, R, light; a ratio R1 defined by SA2/SA1 is equal to or larger than 10; and 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. 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 R1 is greater than or equal to 20. 3. The lighting arrangement (100) according to any one of the preceding claims, where: the number of M-LEDs in the plurality of M-LEDs (101) is X, the number of N-LEDs of the plurality of N-LEDs (102) is Y, and wherein X is greater than or equal to 5 times Y. 4. 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 5. 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 Ll/Wl each of the N-LEDs (102) has a second length, L2, a second width, W2, and a second aspect ratio, AR2, defined by L2/W2, and AR2 is greater than ARI . 6. The lighting arrangement (100) according to any one of the preceding claims, wherein the M-LEDs (101) comprises a luminescent material (160), and wherein at least a subset of the N-LEDs (102) are free from any luminescent material. 7. The lighting arrangement (100) according to claim 6, wherein the N-LEDs (102) further comprises one or more phosphor converted white LEDs. 8. The lighting arrangement (100) according to any one of the preceding claims, wherein: the M-LEDs (101) comprise G LEDs; and the N-LEDs (102) comprise one or more blue, B, LEDs emitting the second light, LG2, having the second emission peak wavelength, 2, in the wavelength range of blue, B, light and comprise one or more red, R, LEDs emitting the third light, LG3, having the third emission peak wavelength, 3, in the wavelength range of red, R, light. 9. The lighting arrangement (100) according to claim 8, wherein: each B N-LED (102) and/or each R N-LED (102) is neighbored by at least 2 G M-LEDs (101). 10. 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 M-LED (101). 11. 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. 12. The lighting arrangement (100) according to any one of the preceding claims, wherein: the G M-LEDs (101) are connected via a first circuitry, CI1, (141), the one or more B N-LEDs (102) are connected via a second circuitry, CI2, (142), the one or more R N-LEDs (102) are connected via a third circuitry, CI3, (143), 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), the emission of the second light emitted by said one or more of B N-LEDs (102) via the second circuitry (142) and the emission of the third light emitted by said one or more R N-LEDs (102) via the third circuitry (143). 13. The lighting arrangement (100) of claim 12, wherein: the first circuitry (121) comprises a first number of parallel arrangements, PAI, - the second circuitry (122) comprises a second number of parallel arrangements, PA2, and PAI is greater than PA2. 14. The lighting arrangement (100) of claim 12, wherein: - the first circuitry (141) comprises a first number of parallel arrangements, PAI, the second circuitry (142) is a serial circuitry. 15. A lamp (200) or a luminaire (200) 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 lighting arrangements capable of providing white light having any desired color temperature. For this purpose, the lighting arrangements are configured with a combination of a plurality of red (R), green (G) and blue (B) LED’s. While it is possible to configure a lighting arrangement with an appropriate combination of R, G and B LEDs in order to obtain such white light, a remaining issue is that of providing a pleasant viewing experience in terms of minimizing spottiness. Spottiness is the visibility of individual LEDs e.g. through a (diffusive) light exit window. A highly scattering/diffusive light exit window may be used, but such configuration will reduce the efficiency significantly e.g. due to multiple reflections and absorption losses. 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) are arranged on said carrier. Each of the M-LEDs comprises a die having a first surface area (SAI), the first surface area having a largest spatial extent (SEI) that is less than or equal to 100 micrometers. The lighting arrangement further comprises a plurality of second light emitting diodes (N-LEDs) arranged on said carrier. Each of the N-LEDs comprises a die having a second surface area (SA2), the second surface area having 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 green (G) light. The wavelength range of green (G) light may be defined as light in a wavelength range from 500 nm to 580 nm. The N-LEDs are configured to emit second light (LG2) having a second emission peak wavelength, (X2) in a wavelength range of blue (B) light, that may be defined as light in a wavelength range from 420 nm to 490 nm, and configured to emit third light (LG3) having a third emission peak wavelength (X3) in a wavelength range of red (R) light, may be defined as light in a wavelength range from 600 nm to 680 nm. A ratio R1 defined by SA2/SA1 is equal to or larger than 10 and 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 or at least 85. Such a lighting arrangement shows an improved performance in terms of reduced spottiness and thereby providing an increased viewing experience. The spottiness depends on the size and luminous flux of each LED. Thus, by using small M-LEDs, i.e. MicroLEDs, the spottiness can be reduced. However, because MicroLEDs are relatively more expensive than ‘normal’ sized LEDs e.g. in terms of assembly costs, a combination of green M-LEDs and ‘normal’ sized red and blue LEDs are used. The reason is that the eyesensitivity is highest for green. By including smaller green LEDs in the lighting arrangement, they are less visible for the human-eye and thereby solving issues at least in terms of spottiness. Thus still, ‘normal’ sized red and blue LEDs can be used. 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 an even higher improvement in reduced spottiness/ increased viewing experience, reduced costs and/or efficiency for the lighting arrangement. In embodiments, SEI may be less than or equal to 80 micrometers, preferably <70 micrometers, more preferably <60 micrometers, most preferably <50 micrometers such as for example 40 micrometers. In embodiments, SE2 may be greater than or equal to 400 micrometers, preferably >500 micrometers, more preferably >600 micrometers, most preferably >700 micrometers such as for example 800 micrometers. In embodiments, R1 may be greater than or equal to 20, preferably >25, more preferably >30, most preferably >35 such as for example 40. The number of M-LEDs of the plurality of M-LEDs m