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:
Dec. 20, 2011
Filed:
Nov. 12, 2009
Yoshiaki Komma, Osaka, JP;
Masahiko Tsukuda, Osaka, JP;
Joji Anzai, Osaka, JP;
Yasumori Hino, Nara, JP;
Yoshiaki Komma, Osaka, JP;
Masahiko Tsukuda, Osaka, JP;
Joji Anzai, Osaka, JP;
Yasumori Hino, Nara, JP;
Panasonic Corporation, Osaka, JP;
Abstract
An object of the invention is to provide an optical recording medium and an optical information device that enable to improve the quality of a servo signal and a reproduction signal. In the case where shape-wise thicknesses tr, tr, tr, and trof a cover layer, a first intermediate layer, a second intermediate layer, and a third intermediate layer are respectively converted into thicknesses t, t, t, and tof the respective corresponding layers each having a predetermined refractive index 'no', a defocus amount with respect to a layer having a refractive index nrα and a thickness trα (satisfying: 1≦α≦n (where α is a positive integer and n is an integer of 4 or more)), and a defocus amount with respect to a layer having the refractive index 'no' and a thickness tα (satisfying: 1≦α≦n (where α is a positive integer and n is an integer of 4 or more)) are equal to each other; and the thicknesses t, t, t, and tsatisfy |t−(t+t+t)|≧1 μm, a difference between any two values of the thicknesses t, t, t, and tis set to 1 μm or more in any case, and |(t+t)−(t+t)|≧1 μm.