The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 06, 2000
Filed:
Feb. 13, 1998
Hiroshi Tani, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A light emission fine adjustment processing unit of an optical storage apparatus brings a light beam to a test zone in an on-track state, sequentially instructs testing powers at two points to a light emission current source circuit, allows a laser diode to emit light, simultaneously instructs a subtraction current of the testing powers at two points to a subtraction current source circuit, and adjusts an instruction value so that a measuring power of a monitor power measuring unit is equal to the instructed testing power. An automatic power control holding unit holds an automatic power control unit at the time of the light emission of the laser diode. A test zone confirming unit activates a light emission adjustment process when the present position lies within a range of the test zone, and prevents a breakage of user data when the present position is out of the test zone range. A light emission timing control unit allows the light emission to be performed in only a data field while avoiding an ID field of a sector.