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. 25, 2000
Filed:
Aug. 12, 1997
Industrial Technology Research Institute, Hsinchu, TW;
Abstract
Method for the preparation of diffractive lens with one single etching step and using one single etching mask. While the widths and intervals of the masked areas of the photo masks are decided under a geometric relation, an etching mask can be prepared on the substrate of the lens where the widths and the intervals of the masked areas can be determined. As the included angle between the etching mask and the plan of the material of the lens is in a certain ratio to the etching efficiency of the etchant to the substrate of the lens, a one step etching process can be developed whereby multilevel diffractive lens with required number, widths and heights of the levels can be obtained. This invention also provides an oxidation-isotropic etching process on the diffractive lens so prepared.