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:
Oct. 18, 1994
Filed:
Jun. 14, 1993
Takayuki Yoshioka, Tokyo, JP;
Akira Nitta, Tokyo, JP;
Pioneer Electronic Corporation, Tokyo, JP;
Abstract
A projection lens has a five-group structure, in which a first-group lens is a positive lens, a second-group lens is a negative lens, third- and fourth-group lenses are respectively positive lenses, and a fifth-group lens is a negative lens. The projection lens has a half view angle of 34.degree. or greater, and satisfies the following conditions: 0.04<d.sub.4 /f.sub.0 <0.08, 0.2<.phi..sub.1 <0.9, -0.6<.phi..sub.2 <0, 0.7<.phi..sub.3 <1.0, 0<.phi..sub.4 <0.5, and -1.36<.phi..sub.5 <-0.6, where: f.sub.0 : focal distance of the overall system, d.sub.4 : on-axis interval between the second-group lens and the third-group lens, .phi..sub.1 : power of the first-group lens, .phi..sub.2 : power of the second-group lens, .phi..sub.3 : power of the third-group lens, .phi..sub.4 : power of the fourth-group lens, and .phi..sub.5 : power of the fifth-group lens, (where .phi..sub.1 -.phi..sub.5 are respectively values obtained when the optical power of the overall system is set to 1).
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile