Patent ID: 7323672
Filing Date: 2008-01-29
Classification: G01J

Abstract:
1. An ambient light sensor structure, comprising: a pair of light sensors for providing a current responsive to impingement of incident light thereon, each of said light sensors providing a dark current absent said impingement of incident light thereon; a power supply, said power supply providing at least one group of voltage interfaces; a converter coupled to said pair of light sensors and said power supply, said converter including a pair of current to pulse converters respectively coupled to said pair of light sensors, each of said pair of current to pulse converters having a plurality of first inputs coupled to said group of voltage interfaces and a second input coupled to a corresponding one of said light sensors, each of said pair of current-to-pulse converters providing output pulse signals responsive to said current of said corresponding light sensor, wherein said output pulse signals of each of said pair of current-to-pulse converters include an equal number of output pulse signals in said absence of impingement of incident light on said pair of light sensors representing said dark current of said pair of light sensors; and a pulse processing unit having a pair of inputs respectively coupled to said output pulse signals of said pair of current-to-pulse converters and providing an output voltage corresponding to a luminosity of the incident light with said dark current nulled.