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:
Nov. 04, 1986
Filed:
May. 13, 1983
Kyohei Fukuda, Fujisawa, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A projection lens for magnifying an image displayed on a cathode-ray tube and projecting the magnified image on a projection screen comprises a first lens having a substantially plano surface opposite to the cathode-ray tube and a concave surface, a second lens which is convex meniscus lens having a concave surface opposite to the concave surface of the first lens, a third lens having a strongest positive refracting power and at one convex surface, and a fourth lens spaced apart by a predetermined distance from the third lens having at least one convex surface. The first to fourth lenses are arranged in the above order from the side of the cathode-ray tube, and the predetermined distance between the third and fourth lenses is large enough to permit interposition of a plano reflecting mirror therebetween.