US 7,321,533 B2
Optical pickup device having a wavelength selecting film and an optical reflector
Hiroshi Katayama, Higashi-Hiroshima (Japan); and Shinichi Tokuno, Higashi-Hiroshima (Japan)
Assigned to Sharp Kabushiki Kaisha, Osaka (Japan)
Filed on Mar. 19, 2003, as Appl. No. 10/391,185.
Claims priority of application No. P2002-078806 (JP), filed on Mar. 20, 2002; and application No. P2002-266567 (JP), filed on Sep. 12, 2002.
Prior Publication US 2003/0218952 A1, Nov. 27, 2003
Int. Cl. G11B 7/125 (2006.01)
U.S. Cl. 369—53.26  [369/112.21] 17 Claims
OG exemplary drawing
 
1. An optical pickup device comprising:
a first light source that emits a first laser beam of a wavelength;
a second light source that emits a second laser beam having a wavelength different from the wavelength of the first laser beam;
an object lens configured to concentrate the first and second laser beams on a data recording surface of an optical disk;
an optical monitor configured to detect a quantity of light of the second laser beam; and
an optical separator having,
a wavelength selecting film configured to reflect the first laser beam emitted from the first light source toward the object lens, and to transmit the second laser beam emitted from the second light source to the object lens, and
a reflector configured to reflect a part of the second laser beam emitted from the second light source toward the optical monitor;
the optical separator having a first prism located on a side proximate to the first light source and a second prism located on a side proximate to the second light source, wherein
at least a part of one side surface of the first prism is bonded to at least a part of one side surface of the second prism with the wavelength selecting film placed between the bonded part of the one side surface of the first prism and the bonded part of the one side surface of the second prism; and
said one side surface of the second prism comprises an exposed non-contact surface which extends from the bonded part thereof and which does not contact with said one side surface of the first prism, said non-contact surface of the second prism comprising the reflector.