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:
Feb. 21, 1989
Filed:
Jul. 02, 1987
Tetsuya Nishida, Koganei, JP;
Motoyasu Terao, Tokyo, JP;
Yasushi Miyauchi, Hachioji, JP;
Shinkichi Horigome, Tachikawa, JP;
Kazuo Shigematsu, Saitama, JP;
Norio Ohta, Sayama, JP;
Toshimitsu Kaku, Sagamihara, JP;
Masahiro Ojima, Tokyo, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In an information recording apparatus according to this invention, since it is not necessary to dispose any differential circuit, which was required heretofore, it is possible to fabricate it with a low cost and its error rate is also very small. Furthermore, since the mean reflectivity on the recording track does almost not vary by the fact that information is recorded there, no tracking off-set or focusing off-set is produced. Thus effects of this invention are remarkable.