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:
Sep. 28, 1976
Filed:
Oct. 15, 1974
Robert W Mitchell, St. Joseph, MI (US);
Photo Systems, Inc., Dexter, MI (US);
Abstract
A color filter head for attachment to photographic enlargers has a universal mount adapted for ready attachment to lens mounts regardless of size and a unique system for sequential color addition and integration to produce a color corrected print. The filter head includes a manually rotatable, adjustable filter disc assembly having high-density filter segments which are relatively movable under an overlying cover disc having two opposed open quadrants. The filter assembly acts like a balanced fly wheel which is mounted beneath the enlarger lens. In normal use, the light from the lens passes through the open quadrants of the cover disc and through the portion of the filter material disposed in the open quadrants as the wheel is manually rotated during the printing step. The system thereby utilizes a method of sequential light addition and integration. Sequential periods of white and colored light are integrated to produce the desired total exposure. By proper filter disposition beneath the lens during exposure, desired color balance is obtained in the finished color print. The periphery of the cover disc has calibrations thereon whereby the desired degree of effective color density is readily and accurately achieved by mere tab movement.