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. 04, 2000
Filed:
Oct. 08, 1997
Richard K Steele, Lewisville, TX (US);
Vari-Lite. Inc., Dallas, TX (US);
Abstract
A projection zoom lens system is used in imaging and non-imaging modes for entertanment and architectural illumination, providing 8:1 zoom ratio in an imaging mode and 20:1 zoom ratio in a non-imaging mode. When coupled with a variable aperture iris, beam size control is obtained with 120:1 ratio. The lens system comprises four lens groups: a first group having a positive refractive power, a second group having a negative refractive power, a third group having a negative refractive power, and a fourth group having a positive refractive power. In the imaging mode, the third group is adjusted axially to vary magnification while the second group is adjusted axially to focus on the object. In the non-imaging mode, the second and third groups are brought into close proximity with each other and adjusted axially as a unit to vary magnification. The fourth group remains fixed and the first group can be adjusted axially to focus the image at different throw lengths.