Method and system for broad area field inspection of a moving web, particularly a printed web

US5256883A · kind A · utility

Assignee

• MAN Roland Druckmaschinen AG · DE

Inventors

• Armin Weichmann · Kissing, DE
• Theodor Tatarczyk · Drolshagen, DE

Key dates

• Filing date: Oct 13, 1992
• Grant date: Oct 26, 1993
• Expiry date: Oct 13, 2012

Classification

• Technology area (CPC G): Physics
• CPC primary: G01J2001/448
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Information is received from an image on a moving substrate. Flash exposure is used, defining operating or exposure cycles. The reflection or a representation of the image is subdivided into a matrix having n columns and m rows or lines. The sensor is a charge coupled device (CCD), arranged to have a sensing area (11) with n columns and m rows or lines, and a storage region or section (12), likewise arranged to have storage cells of n and m columns and rows or lines. Information of any one image element, upon sensing, is shifted by a line transfer pulse by one image line. The line transfer pulses are synchronized with web movement of the substrate and operate as shift pulses. The m line, at the first transfer line shift pulse, is shifted into the first line or row of the matrix of the storage portion of the CCD. For each operating cycle, at least one line transfer pulse is used. The information of the image elements can be read out serially from the storage portion (12) at high speed. The storage portion of the CCD chip is protected against exposure to light.