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. 02, 2013
Filed:
May. 16, 2012
Koji Hirata, Yokohama, JP;
Takanori Hisada, Yokohama, JP;
Masahiko Yatsu, Fujisawa, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A projection type image display apparatus includes a first lens group including a plural number of lenses being disposed in a direction of propagation light with respect to an image display element, a second lens group including a plural number of lenses being disposed in a direction of propagation light with respect to said first lens group and a reflection mirror, which is configured to reflect light emitted from at least one of said first and second lens groups, so as to project the light obliquely upon a screen. A ratio (Lo/Lp) of a diagonal size (Lo) of said screen and a distance (Lp) from a center of said reflection mirror to said screen is at least 2, and the second lens group includes a refractive lens having a negative power and a rotationally symmetric surface configuration.