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:
Jul. 04, 2006
Filed:
Feb. 15, 2002
Applicants:
Kaneyoshi Yagi, Saitama, JP;
Masato Kawabata, Saitama, JP;
Toshiaki Katsuma, Saitama, JP;
Inventors:
Assignee:
Fujinon Corporation, Saitama, JP;
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
G11B 7/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
In a diffraction type optical pickup lens, at least one surface of a convergent lens is formed with such an aspheric surface that a luminous flux having a wavelength λis converged at a first predetermined position. At least one surface of the convergent lens is formed with a zone plate having such a wavelength selectivity that a luminous flux having a wavelength λis converged at a second predetermined position whereas the luminous flux having a wavelength λis transmitted therethrough as it is. The convergent lens is transparent to the luminous fluxes having the wavelengths λand λ.