Colour matching desk for visual and measuring quality control of printed sheets - has X=Y control deflecting projector so that light beam covers while sheet area rapidly and photoelectric scanner supplying evaluating unit

摘要

The position of the scanner (5) is automatically detected. An overhead projector (7) directs a light beam (8) onto any selected position of the printed sheet (2) placed on the test desk (1). The projector is controlled by an X-Y deflection stage (9) so that the light beam rapidly covers all areas of the sheet. The scanner can be manually positioned on the sheet. The scanner, in the form of a hand-held densitometer, colour analyser or video measuring head, includes a photosensor (10) which immediately delivers a signal when the light beam impinges on it. The evaluating unit (11) assigned to the photosensor cooperates with the deflection stage and registers the position of the measuring spot from the deflection of the light beam at the time a signal is delivered from the photosensor. ADVANTAGE - Measuring at any point manually selected. This position is registered without hinderance of visual evaluation.