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:
Sep. 12, 1989
Filed:
Jul. 15, 1986
Takuya Tamaru, Hamamatsu, JP;
Tatsuo Fushiki, Hamamatsu, JP;
Yamaha Corporation, Hamamatsu, JP;
Abstract
A focus search device in an optical type disc playback device comprises an optical system for reading a signal of an optical type disc such as a video disc and a digital audio disc, an optical system moving device for moving the optical system compulsorily in a focusing direction to a focus servo range and a vibration imparting device for imparting vibration to a sliding portion of the optical system such as an object lens while the optical system is being compulsorily moved. Vibration applied to the sliding portion of the optical system puts a shaft and a bearing supporting the optical system in a vibrating state thereby facilitating the movement of the optical system and preventing occurrence of a stick slip.