Title:
OPTICAL HEAD DEVICE
Document Type and Number:
Japanese Patent JP3049408
Kind Code:
B2
Abstract:
PURPOSE: To miniaturize the optical head device by forming a polarization beam splitter film directly on the photodetecting surface of a photodetector.
CONSTITUTION: The polarizable thin film consisting of multilayered dielectric films, etc., is directly formed on the photodetecting surface of the photodetector 8 and is used as the polarization beam splitter film (PF) 7. The PF 7 has the polarization characteristic to totally reflect, for example, S polarized light and to allow the transmission of the entire P polarized light. The light emitted from a semiconductor laser 1 is totally reflected by the PF 7 and is directed toward the optical disk 5. The light reflected therein is transmitted through the PF 7 and is made incident on the photodetector 8. The photodetecting surface of the photodetector 8 is quadrisected by, for example, dividing lines parallel and orthogonal with the track direction. The output signals from the respective regions are processed, by which the control, such as focusing and tracking, is conducted. The semiconductor laser 1 and the photodetector 8 are made into an integral module by this constitution.
Inventors:
Akitomo Ohba
Yutaka Yamanaka
Ryuichi Katayama
Yutaka Yamanaka
Ryuichi Katayama
Application Number:
JP20352093A
Publication Date:
June 05, 2000
Filing Date:
August 18, 1993
Export Citation:
Assignee:
NEC
International Classes:
G11B7/135; (IPC1-7): G11B7/135
Domestic Patent References:
| JP63263635A | ||||
| JP2162541A |
Attorney, Agent or Firm:
Naoki Kyomoto (2 outside)