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:
Jun. 21, 1994
Filed:
Oct. 05, 1992
Keisuke Kikuchi, Tsukuba, JP;
Agency of Industrial Science & Technology, Tokyo, JP;
Abstract
A spherical recess is provided to one end wall of a first planar lens and the opposite end walls of a second planar lens, the first planar lens having a thicknesswise index distribution in the vicinity of the one end wall whereas the second planar lens has a thicknesswise index distribution in the vicinity of each of the opposite end walls. A high refractive index homogeneous sphere lens is sandwiched between the first planar lens and the second planar lens to be brought into contact with the spherical recesses. A homogeneous semi-sphere lens is held to contact the other spherical recess of the second planar lens. The homogeneous sphere lens side first planar lens and second planar lens of the first planar lens and second planer lens increase in refractive index toward the homogeneous sphere lens so that the sphere lens is corrected in spherical aberration, and so that distribution gradient of the refractive index is selected for correcting the sphere lens in coma. The homogeneous semi-sphere lens side heterogeneous portion of the second planar lens decreases in refractive index toward the homogeneous semi-sphere lens to correct the whole curvature of field, and the refractive index of the homogeneous semi-sphere lens is selected to be low for correcting the distribution.