Patent ID: 7034284

Claim:
An optical sensor for projecting light rays into a field of detection for detecting information of a subject in the field of detection based on light rays passing through the field of detection, said optical sensor comprising: a housing having an elongated window; a light projecting prism having a first surface and a second surface disposed at a predetermined angle less than 90° to said first surface and disposed adjacent to said elongated window of said housing; light source means for providing light rays, said light source means having at least a portion thereof disposed in said housing; a collimator lens collimating the light rays emanating from said light source means so as to provide collimated light rays therefrom; wherein said light projecting prism for refracting the collimated light rays incident on said first surface at an angle less than 90° and for expanding a width of the collimated light rays along a longitudinal direction of said elongated window to project the collimated light rays from said second surface into the field of detection through said elongated window of said housing; wherein said housing is a first housing, said optical sensor further comprising a second housing having a condenser lens therein for condensing the light rays projected into and passed through the field of detection and a light receiving element in said housing for receiving the light rays condensed and focused thereon by said condenser lens to convert intensity of the light rays incident thereupon into an electric signal.