Patent ID: 9107250
Filing Date: 2015-08-11
Classification: G01K,H05B

Abstract:
1. A method of operating an LED-based lighting system with a plurality of LEDs, the method which comprises: energizing the LEDs for turning on the lighting system by supplying electrical current to the LEDs at a rated maximum power; maintaining the energization of the LEDs at the rated maximum power for a predetermined time period, the predetermined time period representing a time period during which the LEDs is allowed to be driven at the rated maximum power without reaching a critical temperature for a junction temperature; subsequently reducing the electrical current to a reduced value at which the junction temperature of the LEDs does not further rise on continued use and maintaining the electrical current at the reduced value so that the LEDs will not reach the critical temperature; subsequently turning off the LEDs; upon a renewed turning on of the LEDs, measuring an extinction time period that is defined as a period from a last time the LEDs were turned off to an instant at which the LEDs are turned on again; and shortening the time period during which the LEDs are driven at the rated maximum power in proportion with a length of the measured extinction time period.