Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
SYSTEM FOR RECORDING ON OPTICAL DISK
Document Type and Number:
Japanese Patent JPH05101393
Kind Code:
A
Abstract:

PURPOSE: To increase recording density by making the magnitude of the track pitch of a recording pit on an optical disk coincide with the radius of the most inside dark ring of a beam spot and simultaneously lowering the reflectance in a land part than the same of a pit part.

CONSTITUTION: The luminous intensity distribution 31 of the beam spot formed on the optical disk by an optical pickup device consists of a central part and a large number of a ring shape light distribution around the central part and dark rings with the luminous intensity 0 between the rings are present. The radius of the most inside dark ring is made to coincide with a tracking pitch and simultaneouly the reflectance of the land part 32 is reduced than that of the pit part. Thus, by narrowing a pit width by shifting the pit width where the modulation factor of a light beam by the diffraction of the pit becomes the maximum to a narrow side, cross-talk amount is reduced. Thus, the recording density is increased without changing the plural conditions of the pickup.


Inventors:
TANAKA NOBUKAZU
Application Number:
JP29032491A
Publication Date:
April 23, 1993
Filing Date:
October 11, 1991
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
NIPPON COLUMBIA
International Classes:
G11B7/00; G11B7/0045; G11B7/135; (IPC1-7): G11B7/00; G11B7/135
Attorney, Agent or Firm:
Kazumi Yamaguchi