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:
Aug. 25, 1987
Filed:
Mar. 28, 1986
Izumi Miyake, Kaisei, JP;
Kiyotaka Kaneko, Kaisei, JP;
Katsuo Nakadai, Kaisei, JP;
Kazuya Oda, Kaisei, JP;
Fuji Photo Film Co., Ltd., Kanagawa, JP;
Abstract
A tracking apparatus for tracking a track recorded in a rotary recording medium which rotates at a predetermined constant speed has a playback head for sensing a signal out of a desired one of tracks each being provided in the recording medium such that a beginning and an end of recording coincide with each other includes a head transport mechanism for supporting the playback head movably along the recording medium, an envelope detector for detecting an envelope of the signal sensed by the playback head, and a controller for controlling the head transport mechanism to move the playback head to a position where a desired one of the tracks is located. The head transport mechanism includes a head position detector for detecting a position of the playback head on the recording medium. The controller is constructed to control the head transport mechanism to move the head to compute for one of the tracks two different positions where a level of the envelope detected by the envelope detector has a reference value, then compute an intermediate position between the two positions, and then control the head transport mechanism to move the head to the intermediate position. The reference value may be controlled higher when the position of the head is associated with any of the tracks having comparatively large diameters than when it is associated with any of the tracks having comparatively small diameters.