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:
Aug. 26, 2014
Filed:
Apr. 26, 2012
Tsan-haw Lee, Taichung, TW;
Tsan-Haw Lee, Taichung, TW;
Asia Optical Co., Inc., Taichung, TW;
Abstract
A zoom projection lens for a projector includes a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a positive refractive power in order along an optical axis from an object side to an image side. The first lens group has an aspheric lens. The third lens group has an aspheric lens and an aperture stop. F-number of the zoom projection lens in wide-angle is less than 2.1, i.e. enlarging a diameter of the aperture stop, to increase the optical efficiency of the projector. Besides, the aspheric lenses may reduce the aberration because of the large aperture stop.