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. 13, 1979
Filed:
Nov. 04, 1977
John Pone, Jr, Minneapolis, MN (US);
Pako Corporation, Minneapolis, MN (US);
Abstract
In the photographic printer of the present invention, color balancing is performed through an interactive procedure with the user. A test print of a reference film negative is made and the densities of the test print are measured and entered into the printer by the user. The printer derives and displays modified exposure times for the reference negative from the density of the reference negative, the desired reference print density values and the measured density values of the test print. The printer then performs a series of density measuring and exposure time calculating cycles during which time, if the modified exposure times differ from desired reference exposure times, the user changes the color content of the print lamp light by moving subtractive filters. The calculated exposure times are displayed so that the operator can monitor the changes in exposure time for each color channel as the subtractive filters are adjusted. The procedure continues until the displayed exposure times equal the desired reference exposure times.