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:
Apr. 20, 2004
Filed:
Sep. 12, 2002
Enplas Corporation, Saitama, JP;
Abstract
Provided in the present invention are an image pickup lens and a design method thereof which can achieve miniaturization of the system and capable of remarkably improving the optical characteristic with a simple structure. By forming a second face on the image pickup surface side of a lens body into a Fresnel face and unifying a diffraction element with at least a first face on the object face side or the second face on the image pickup surface side of the lens body, it becomes possible to correct the Petzval sum and reduce the curvature of the field so that an excellent image plane can be obtained. Also, due to the color dispersion characteristic of the diffraction element, chromatic aberration can be well corrected. Thereby, the optical characteristic of the image pickup lens can be remarkably improved.