Back to results
US 4,947,384 AGranted
Optical disk having narrow and wide guide grooves
AssigneesPioneer Electronic Corporation, Pioneer Video Corporation
InventorsKenji Suzuki, Toshihiko Takishita, Satoru Fukuoka, Hirokazu Hashikawa, Tsuyoshi Hayashi, Minemasa Ohta
Life of this patent
Estimating the term…
Abstract
An optical disk of the type including guide grooves is improved by regulating the width of the grooves, and thus the width of the adjacent land portion, in accordance with the type of information recorded at that part of the land.
Claims4
An optical disk, comprising:
- guide grooves formed concentrically or spirally on the disk;
- and
- land portions each provided between adjacent ones of said guide grooves, said land portions including a signal recording region and a preformat region on which concave/convex pits having address information are formed;
- wherein said preformat region of said land portions has a substantially uniform width which is broader, in the radial direction of the disk, than that of said signal recording region, and a first portion of said guide grooves adjacent to said preformat region has a substantially uniform width which is narrower, in the radial direction of said guide grooves, than that of a second portion of said guide grooves which is adjacent to said signal recording region.
1 more element
Dependencies are inferred from the claim text.