US 12,075,533 B2
Light emitting diode, LED, based lighting device arranged to emit colored light as well as a corresponding method for operating such a LED based lighting device
Marcel Beij, Eindhoven (NL); Eugen Jacob De Mol, Eindhoven (NL); and Henricus Marius Joseph Maria Kahlman, Eindhoven (NL)
Assigned to SIGNIFY HOLDING B.V., Eindhoven (NL)
Appl. No. 17/761,476
Filed by SIGNIFY HOLDING B.V., Eindhoven (NL)
PCT Filed Sep. 28, 2020, PCT No. PCT/EP2020/077106
§ 371(c)(1), (2) Date Mar. 17, 2022,
PCT Pub. No. WO2021/063888, PCT Pub. Date Apr. 8, 2021.
Claims priority of application No. 19201231 (EP), filed on Oct. 3, 2019.
Prior Publication US 2022/0353967 A1, Nov. 3, 2022
Int. Cl. H05B 45/10 (2020.01); G09G 3/32 (2016.01); H05B 45/20 (2020.01); H05B 45/325 (2020.01); H05B 45/46 (2020.01)
CPC H05B 45/20 (2020.01) [G09G 3/32 (2013.01); H05B 45/325 (2020.01); H05B 45/46 (2020.01)] 10 Claims
OG exemplary drawing
 
1. A Light Emitting Diode (LED) based lighting device arranged to emit colored light, wherein said LED based lighting device comprises:
a first LED channel comprising at least one LED arranged for emitting light at a first color and a switch;
a second LED channel comprising at least one LED arranged for emitting light at a second color, said second color being different to said first color and a further switch;
a memory for storing aging properties of each LED of the first LED channel and the second LED channel; and
a controller arranged for:
activating said first LED channel and said second LED channel by controlling the switch and the further switch with a pulse width signal based on a color ratio such that said LED based lighting device emits light having a particular color; and
keeping track of amounts of time that said first LED channel and said second LED channel are activated, and correcting said color ratio based on the aging properties of each of the LEDs and said tracked amount of time that said first LED channel has been activated and said tracked amount of time that said second LED channel has been activated, thereby ensuring color consistency of said particular color of said LED based lighting device over time.