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:
May. 05, 1998
Filed:
Oct. 24, 1996
Hidekazu Nakai, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
A disk drive capable of determining the diameter of the currently loaded disk in a short time without the use of additional attachments such as optical sensors. Servo gains are first set to permit rotation of a 12-cm CD, and the servo is turned on. The CD is rotated at a steady rotational speed regardless of its diameter. The servo is turned off when a sub-code synchronizing signal is detected from the CD. Acceleration pulses are generated to start accelerating the spindle motor simultaneously with the starting of a timer. The timer is stopped when the next sub-code synchronizing signal is detected, and the servo is again turned on. If the value on the timer is longer than a reference time, the loaded CD is found to be a 12-cm CD and the appropriate servo gains are set for the 12-cm CD; if the timer value is shorter than the reference time, the CD is found to be an 8-cm CD and the servo gains are set accordingly.