Patent ID: 6677573
Filing Date: 2004-01-13
Classification: B41J

Abstract:
A laser sensor comprising:a laser source; a condenser lens for converging the light from said laser source; a pin hole plate disposed adjacent to said condenser lens in the opposite side to said laser source, said pin hole plate having a pin hole positioned in the converging beam converged by said condenser lens; and a light detecting portion disposed so as to face to the converging beam passed said pin hole, wherein a diameter of said pin hole is 0.4 to 0.7 mm, and wherein said pin hole plate is disposed at the back side of said condenser lens, and the distance between said pin hole plate and the back surface of said condenser lens is less than &frac15; of the distance (sâ€³) between an image point of said laser source by said condenser lens and a second principal point of said condenser lens.