Method of and apparatus for copying photographic originals

US4565442A · kind A · utility

Assignee

• Agfa-Gevaert NV · BE

Inventors

• Gerhard Benker · Pullach, DE
• Helmut Treiber · Munich, DE

Key dates

• Filing date: Oct 30, 1984
• Grant date: Jan 21, 1986
• Expiry date: Oct 30, 2004

Classification

• Technology area (CPC G): Physics
• CPC primary: G03B27/462
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A series of exposed and developed film strips having various lengths are spliced end-to-end for copying. The resulting band passes through a density measuring station in which the densities of the negatives are measured in the three primary colors and next through a magazine of variable capacity in which a portion of the band accumulates before entering a negative copying station including an exposure control device which regulates the exposures of the negatives on the measured basis of the density values. To insure that values derived from a selected strip are transferred to the exposure control unit when the strip enters the copying station, the splice immediately downstream of the selected strip is arrested in the density measuring station. The band continues to be drawn through the copying station so that the portion which has accumulated in the magazine is fully withdrawn. The portion of the band between the arrested splice and a splice sensor in the copying station has a known length. The arrested junction is now released and a length measuring device begins to measure the length of the portion travelling through the copying station. If the sensor detects a splice when the me…