Document Type and Number:
Japanese Patent JPH0427613
Kind Code:
B2
Abstract:
PURPOSE:To detect the beginning end position for rotation surely by providing plural pieces of unit marks which can be detected as marks for detecting the beginning end position for rotation continuously. CONSTITUTION:Information parts 3, 4 for absolute addresses of tracks are provided to groove-like tracks 2. A mark group 5' for the beginning end position for rotation is formed with >=2 marks for the beginning end position of rotation that can be detected independently, and the top thereof is made coincident with the top of the address information parts. Since the group 5' is long, the group is easily identifiable from noise by flaws.
Inventors:
YAMASHITA HARUO
MATSUO TAMOTSU
OKAMURA HIDEO
BABA TASUKU
MATSUO TAMOTSU
OKAMURA HIDEO
BABA TASUKU
Application Number:
JP14851181A
Publication Date:
May 12, 1992
Filing Date:
September 18, 1981
Export Citation:
Assignee:
MATSUSHITA ELECTRIC IND CO LTD
International Classes:
G11B5/82; G11B3/68; G11B7/00; G11B7/005; G11B7/24; G11B7/24097; G11B9/06; G11B11/00; G11B23/42
Next Patent: JPH0427614