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:
Mar. 03, 1998
Filed:
Jan. 10, 1997
Martin J Maiers, Newberg, OR (US);
In Focus Systems, Inc., Wilsonville, OR (US);
Abstract
A multimedia projector comprises a optical frame that mounts, from back to front, a light source, a back fresnel lens, a back polarizer, an LCD display object, a front polarizer, a front fresnel lens, and a front lens group for projecting images formed by the LCD display object. To provide keystone distortion correction of projected images, the front fresnel lens is manually and selectively tiltable about an axis extending parallel with the plane of the LCD display object. The selective tilting is accomplished by a manually movable fresnel actuator with a cammed surface. A control arm extends between the fresnel actuator and the fresnel lens, and rides on the cammed surface such that a relatively large movement of the fresnel actuator produces a relatively small adjustment in tilt of the fresnel lens in order to permit fine adjustment of the fresnel lens tilt. To provide contrast adjustment, a contrast adjustment mechanism is attached to the back polarizer to permit the manual selective tilting of the back polarizer about an axis extending perpendicular to the front polarizer, in order to optimize contrast of images projected by the front lens group.