Patent ID: 6459672
Filing Date: 2002-10-01
Classification: G11B

Abstract:
An optical head for coping with a plurality of optical recording mediums of different types, comprisinglight radiating means including a first light source for radiating a first laser light and a second light source for radiating a second laser light having a wavelength different from that of said first laser light, said first and second light sources being housed in the same package, light converging means for converging the laser light from said light radiating means towards said optical recording medium, a beam splitter substantially in the form of a flat plate for separating the optical path of the laser light proceeding towards said optical recording medium from that of the laser light reflected from said optical recording medium, and for producing astigmatic aberration in the return laser light, and light receiving means for receiving the return laser light reflected back from said optical recording medium, wherein the relative positions of said first and second light sources of said light radiating means are so set that a straight line interconnecting a spot position of said first laser light illuminated on said optical recording medium and a spot position of said second laser light illuminated on said optical recording medium will be in a range of 45Â±15Â° with respect to a recording track of said optical recording medium, and wherein said light receiving means includes a pair of light receiving sections arranged substantially parallel to a straight line projected on said optical recording medium, said straight line being a straight line interconnecting a spot position of the first laser light illuminated on said optical recording medium and a spot position of the second laser light illuminated on said optical recording medium, each of the light receiving sections being split into four portions by a splitting line substantially parallel to the recording track on a signal recording surface of the optical recording medium and the splitting line substantially perpendicular thereto.