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:
Nov. 02, 1999
Filed:
Nov. 22, 1995
Timothy R Crawford, Needham, MA (US);
Joseph V Demarinis, Winchester, MA (US);
Polaroid Corporation, Cambridge, MA (US);
Abstract
A method and apparatus for compensating for color and brightness variations in a white-light printer is described where the white-light printer automatically adjusts exposure of a photosensitive medium to optimize a printed image thereon. The white-light printer generates compensation factors used by the white-light printer to individually correct for primary colors within an image by monitoring chromatic transmission through the same or equivalent color filters as are being used to expose the photosensitive medium. A method is disclosed where the video output is set at maximum and brightness, or Luma, is varied and measured in foot-Lamberts. The Luma that gives 'white', a film table is recorded, and that Luma is fixed such that proper white, black, and grays are attained. A similar procedure is repeated for each primary color, thereby compensating for color and brightness variations due to differing CRTs and the warm-up state of each CRT.