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:
Apr. 01, 1986
Filed:
May. 11, 1984
Jack Dinsdale, Harrold, GB;
Robert S Berks, Milton Keynes, GB;
Cranfield Institute of Technology, Cranfield, GB;
Elite Townshend, Ltd., Walton-on-Thames, GB;
Abstract
Apparatus for correcting or compensating for the tracking error of the pivotally mounted (1) tone arm (23) of a phonograph includes a first intermediate member (9) to which said tone arm (23) is pivotally (1) connected, a second intermediate member (12) which is rotatably connected to the first intermediate member (9) by a belt (18) and pulleys (13) which are sized in such a way that a photodiode source (21) and a photodiode detector (22) both carried by the second intermediate member (12) will tend to be indirectly moved by a motor to maintain them substantially constantly in register with a point on the tone arm (23). A slotted mask (24) carried by the tone arm (23) is interposed between the source (21) and the detector (22) and its slot defines a central 'null' position in which said motor will not be driven when the required relationship exists. Deviation in either direction will cause the motor to be driven to re-establish this relationship. An insignificant maximum tracking error below 0.1.degree. can readily be attained. Other constructions in which the second intermediate member (12) is omitted and in which the means to control operation of the motor are differently constructed and arranged are described and illustrated.