Printed area measuring apparatus
US4555180A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 18, 1983 |
| Grant date | Nov 26, 1985 |
| Priority date | — |
| Expiry date | Mar 18, 2003 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41F33/0027
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An improved apparatus for measuring the printed area of a printing plate upon which a printing image is formed, of the type having a movable scanning head provided with longitudinally arranged light sources and plural photosensors arranged in parallel with the light sources. The improvement is composed of a proving sensor device separate from and movable independently of the scanning head which includes at least one light source and photosensor. The proving sensor device provides calibration data for correcting the measurements made by the scanning head. It does this by measuring the intensity of reflected light from a totally dark printing area and a non-printing area from anywhere on the printing plate, and a totally reflective surface and totally absorptive surface, which are preferably located apart from the printing plate. The improvement further includes control means for electronically processing the measurement data produced by both the scanning head and proving sensor device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.