Patent ID: 7583363

Claim:
A range finder system for calculating a distance X, comprising: a point light source configured to emit light; a first image pickup device comprising a first lens and a first sensor disposed corresponding to the first lens, the first lens having a first focal length F 1 , the first sensor having a first light-receiving unit for receiving the emitted light; a second image pickup device spaced apart from the first image pickup device a predetermined distance L, the second image pickup device comprising a second lens and a second sensor disposed corresponding to the second lens, the second lens having a second focal length F 2 , the second sensor having a second light-receiving unit for receiving the emitted light; and a processing device electronically coupled to the first image pickup device and the second image pickup device, the processing device configured for calculating a first distance D 1 from a location of an image of the point light source on the first light-receiving unit to a center of the first sensor and a second distance D 2 from a location of the image of the point light source on the second light-receiving unit to a center of the second sensor, and calculating the distance X according to the following equation: X = L × tan ⁢ ⁢ θ 1 × tan ⁢ ⁢ θ 2 tan ⁢ ⁢ θ 1 + tan ⁢ ⁢ θ 2 where θ 1 is a complementary angle for an angle of θ 3 , the tangent of which is the ratio of D 1 to F 1 , and θ 2 is a complementary angle for an angle of θ 4 , the tangent of which is the ratio of D 2 to F 2 .