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. 27, 1997
Filed:
May. 12, 1995
Fujitsu Limited, Kawasaki, JP;
Nippon Telegraph & Telephone Co., Tokyo, JP;
Abstract
An apparatus for reading information by projecting a light beam from an optical head onto an optical disk rotated by a spindle motor. The rotation time of the spindle motor is measured, and upon reaching a predetermined time, a cleaning request signal is sent to an upper order system. The rotation time of the spindle motor is counted by counting pulses generated with the rotation with a first counter stored in the RAM. Upon reaching a predetermined value by the count of the first counter, a second counter stored in a non-volatile memory is updated. Upon reaching a predetermined value by the second counter, a cleaning request is sent to the upper order system for display on a CRT, and a cleaning request flag in a non-volatile memory is set. When the end of cleaning of the apparatus is recognized, the cleaning request flag in the non-volatile memory is cleared.