Photographic copier with masking device and copying method

US5155524A · kind A · utility

Assignee

• Agfa-Gevaert NV · BE

Inventors

• Knut Oberhardt · Holzkirchen, DE
• Wolfgang Zahn

Key dates

• Filing date: Jan 16, 1992
• Grant date: Oct 13, 1992
• Expiry date: Jan 16, 2012

Classification

• Technology area (CPC G): Physics
• CPC primary: G03B27/727
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A photographic copier has an adjustable masking device for masking a master to be reproduced. To determine whether masking is required and, if so, the degree of masking, the density of the master is measured and is then forwarded to a logic circuit which can make the determination. In a first mode of operation, masked and unmasked images of the master are displayed side-by-side on a pair of monitors so that an operator can make adjustments to the mask calculated by the logic circuit. The operator here controls the copying cycle. In a second mode of operation, the copying cycle is automated and the logic circuit decides whether masking is required by calculating a degree of masking and comparing the degree of masking with a relatively low reference value set by the operator. The master is copied without a mask when the calculated degree of masking is less than the reference value. If a copy made by masking is unsatisfactory, the operator can adjust or deactivate the logic circuit and make a new copy. In a third mode of operation, the reference value set by the operator is high. When the calculated degree of masking exceeds the reference value, the logic circuit asks the operator to …