Title: Focus tracking registration for optical reproducing systems

Abstract: A video disc reproducing system wobbles the reading beam across the storage track of the disc and the outputs of two photocells are added to develop both the information signal and a radial beam tracking signal employed to maintain tracking registration of the beam and the storage track. The outputs of these cells are also combined differentially to develop a focus tracking signal used to adjust the focal plane of the reading beam to maintain focus registration. A search feature adjusts the focus conditions over a range but is disabled and is superseded by the focus tracking control arrangement once focus conditions are brought within the operating range of the focus tracking arrangement.

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Inventors: Snopko, Paul A. (Chicago, IL, US)

Application Number: 439657
Filing Date: 1974-02-04
Publication_date: 1976-01-13
Assignee: Zenith Radio Corporation (Chicago, IL)
Primary Class(es): 369/44.13 250/201.5, 369/44.29
Other Classes:
US Patent Ref:

3198880	Aug, 1965	Toulon	179/100.
3553455	Jan, 1971	Sato et al.	250/208.
3610934	Oct, 1971	Turner	250/201.
3673412	Jun, 1972	Olson	179/100.
3848095	Nov, 1974	Wohlmut	179/100.

Other Refs:
Primary Examiner: Konick, Bernard
Assistant Examiner: Lucas, Jay P.
Attorney: O'Connor; Cornelius J.