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. 23, 1989
Filed:
Sep. 23, 1987
Kenta Mikuriya, Tokyo, JP;
Masuo Hanawaka, Tokyo, JP;
Akira Ohya, Tokyo, JP;
Hideo Hirukawa, Tokyo, JP;
Shoji Uehara, Tokyo, JP;
Kenichi Yamakawa, Tokyo, JP;
Yokogawa Electric Corporation, Tokyo, JP;
Abstract
A test system for optical disks, comprising a spindle motor for bearing and rotating an optical disk at a constant speed; a measuring head, comprising focus servor and tracking servo mechanisms for causing the focal point of a laser beam irradiating the optical disk to follow the guide groove of the disk, for generating an output signal proportional to the intensity of the reflected beam coming from the optical disk; a feed mechanism for moving the measuring head in a radial direction of the optical disk; a control circuit for controlling the operations of the spindle motor, the focus servo and tracking servo mechanism of the measuring head, and the feed mechanism; a measurer for performing desired measurements in response to the output signal from the measuring head; and a computer for commanding the control circuit and the measurer and for processing the measured data of the measurer, whereby all the measurements are accomplished with the guide groove of the disk being under the focus and tracking servos.