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:
Sep. 20, 1988
Filed:
Dec. 30, 1987
Applicant:
Inventors:
Tetsuro Minemura, Hitachi, JP;
Hisashi Andoh, Hitachi, JP;
Isao Ikuta, Iwaki, JP;
Yoshiaki Kita, Katsuta; all of, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ; G11B / ;
U.S. Cl.
CPC ...
369100 ; 369288 ; 369108 ; 3461351 ; 365119 ;
Abstract
An information recording and reproducing apparatus is disclosed, which makes use a recording medium made of a metal or alloy having phases different in their crystalline structures at at least two temperature regions in the solid state and capable of causing phase transformation by heating and quenching. Information such as signals, letters, patterns and symbols are recorded in a distinctive manner and erased by making use of a change in the spectral reflectance owing to the phase transformation. Rewriting can be made easily by making use of the energy of a light beam such as a laser beam.