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:
Jan. 02, 2018
Filed:
Aug. 11, 2016
Calin Technology Co., Ltd., Taichung, TW;
CALIN TECHNOLOGY CO., LTD., Taichung, TW;
Abstract
A fixed-focus projection lens, in order from an image side to an image source side along an optical axis, includes a first lens with negative refractive power, a second lens with positive refractive power, a third lens with negative refractive power, a fourth lens with positive refractive power, a fifth lens with positive refractive power, and a sixth lens with positive refractive power. The second lens is a biconvex lens. While projecting, a light enters the fixed-focus projection lens from the image source side, and passes through the fixed-focus projection lens. Further more, at least one surface of the first lens is aspherical, a refractive index of the second lens is greater than 1.8, and a refractive index of the fifth lens is greater than 1.7. Such arrangement helps to lower a spherical aberration of spherical lens, shortening the optical system, and effectively lower the distortion.