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:
Jun. 27, 2000
Filed:
Mar. 13, 1998
Nobuyuki Asai, Kanagawa, JP;
Shinobu Nakamura, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
A disc reproduction device, in which at the time of normal reproduction, a rotational speed of a spindle is detected based on a reproduction signal from the disc by a rotational speed counting circuit, a control signal that makes a speed error with respect to a reference speed zero is given to a first VCO as the control voltage thereof, a reproduction clock is generated while controlling the frequency and phase at a digital PLL circuit by using the oscillation output thereof as the reference frequency of the first PLL circuit containing a second VCO and in which, at the time of access, the control signal to the first VCO is switched to the output signal of the phase comparator by the switch circuit under the control of the controller and a multiple PLL circuit containing the first VCO, phase comparator, LPF, and so forth, is constituted to make the oscillation frequency of the first VCO track the reproduction speed at the destination of access predicted based on the access information by the controller. As a result, the access time can be reduced.