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:
Mar. 18, 2014
Filed:
Dec. 27, 2007
Hiroshi Hoshino, Tokyo, JP;
Nobuaki Hirai, Tokyo, JP;
Hiroshi Hoshino, Tokyo, JP;
Nobuaki Hirai, Tokyo, JP;
Mitsubishi Electric Corporation, Tokyo, JP;
Abstract
An optical disc driving device includes a control circuitfor performing a gain adjustment for each of two recording surfaces of a multilayered optical discon the basis of an FE signal in such a way as to maintain a state in which light is focused onto either of the recording surfaces, to generate a focus servo loop signal, and for generating a focus jump signal for causing either a transition from a state in which the light is focused onto one recording surface to a state in which the light is focused onto the other recording surface, or a transition in the opposite direction from a threshold set up on the basis of an amount of gain adjustment, and a focus actuator driving circuitfor performing either a focus jump or an operation of maintaining the state in which the light is focused.