Patent ID: 6483786
Filing Date: 2002-11-19
Classification: G02B,G11B

Abstract:
A light guide path element comprising:a first light guide path for guiding a light beam having a first wavelength; a second light guide path for guiding a light beam having a second wavelength; a first separating device for irradiating the light beam having the first wavelength irradiated from a first light source onto an information record medium and transmitting a light beam reflected therefrom; a second separating device for irradiating the light beam having the second wavelength irradiated from a second light source onto an information record medium and transmitting a light beam reflected therefrom; a first grating for input-coupling one portion of the light beam transmitted through said first separating device to said first light guide path and transmitting another portion of the light beam transmitted through said first separating device; a second grating for input-coupling one portion of the light beam transmitted through said second separating device to said second light guide path and transmitting another portion of the light beam transmitted through said second separating device; a first light receiving portion for receiving the light beam transmitted through said first grating or said second grating; a second light receiving portion for receiving the light beam guided by said first light guide path; and a third light receiving portion for receiving the light beam guided by said second light guide path.