Patent ID: 7869007

Claim:
A ranging apparatus comprising: a synchronizing signal generator for generating a synchronizing signal at a constant interval; a light-emitting unit for emitting a modulated light which is intensity-modulated, in response to said synchronizing signal input thereto; a light-detecting unit for detecting a reflected light from an object that is irradiated with said modulated light, in response to said synchronizing signal input thereto; a calculating unit for calculating the distance up to said object based on the phase difference between said modulated light and said reflected light; and a synchronizing signal control unit for changing an arrival time of said synchronizing signal from said synchronizing signal generator at said light-detecting unit, depending on the number of times that said synchronizing signal is generated; wherein said light-detecting unit samples an amount of the reflected light in exposure periods established at a constant cycle length with reference to a time at which said synchronizing signal is input thereto; wherein said light-detecting unit comprises an exposure period changer for changing time lengths of said exposure periods based on an external control signal; and wherein said synchronizing signal control unit changes the arrival time of said synchronizing signal from said synchronizing signal generator at said light-detecting unit, based on the number of times that said synchronizing signal is generated and the changed time lengths of said exposure periods.