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. 16, 1992
Filed:
Oct. 18, 1991
Kiyohiko Sato, Nagaokakyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A compound corrective lens for use in light exposure in the manufacture of color CRTs includes plurality of lens elements, each having an elementary surface, formed in combination a compound surface on the exit side of the lens, with steps formed at the boundaries between adjacent lens elements to connect edges of the elementary surfaces of the adjacent lens elements. The surfaces are so arranged that the steps falls from the elementary surface on the inner side closest to the optical axis of the lens) to the elementary surface on the outer side (farthest from the optical axis). With such an arrangement, the adverse effect of the steps covered with a light-absorbing layer is reduced. That is, the effective areas of the elementary surfaces are enlarged, and thus the distortion of the lens surface is suppressed.