Patent ID: 9743490
Date: 2017-08-22
CPC Classifications: H05B,Y02B

Claim:
1. A lighting device, comprising: a light source, configured to emit light to illuminate an environmental scene; a driving module, coupled to the light source, and configured to drive the light source; a sensing module, configured to obtain a brightness value corresponding to the environmental scene; and a control module, coupled to the driving module and the sensing module, and configured to control the driving module to use a first current to drive the light source, control the sensing module to obtain a first brightness value, control, when the first brightness value is less than a reference brightness value, the driving module to use a second current to drive the light source, the second current being greater than the first current by a predetermined amplitude value, control the sensing module to obtain a second brightness value, compare the second brightness value with the first brightness value, determine that the light source is in a thermal attenuation state when the second brightness value is less than or equal to the first brightness value, and determine that the light source is in an optical attenuation state when the second brightness value is greater than the first brightness value.