Title:
LIGHT EMITTING AND RECEIVING ELEMENT, OPTICAL PICKUP DEVICE AND FOCUSING ERROR SIGNAL DETECTING METHOD
Document Type and Number:
Japanese Patent JP3740777
Kind Code:
B
Abstract:
PROBLEM TO BE SOLVED: To provide a light emitting/receiving element small in size, light in weight, having high reliability and capable of applying it to a magnetooptical disk, and to provide an optical pickup device utilizing the element.
SOLUTION: This light emitting/receiving element 21 has light receiving element groups 31, 33, 34 formed on a first semiconductor substrate 25, a light emitting element 27 formed on a second semiconductor substrate 26 mounted on the first semiconductor substrate and a prism 28 made of a birefringent material. The light receiving element groups 31, 33, 34 have a first photodetector 31 for receiving a light beam transmitted through a translucent film 30 from an optical path branching surface 28a through the prism 28 and a second and a third photodetectors 33, 34 for receiving two groups of light beams separated at the time of making incident on the prism, reflected by the half-transmitting film 30 and reflected by the surface on the opposite side of the prism 28.
Inventors:
Nishi, Noriaki
Sasaki, Yasuo
Saito, Kimihiro
Sasaki, Yasuo
Saito, Kimihiro
Application Number:
JP1997000036764
Publication Date:
November 18, 2005
Filing Date:
February 20, 1997
Export Citation:
Assignee:
SONY CORP
International Classes:
G11B7/09; G11B11/10; G11B7/135; G11B11/105; G11B7/09; G11B7/135; G11B11/00; (IPC1-7): G11B7/09; G11B7/135; G11B11/10; G11B11/10