Monitoring of printed sheets
US5351834A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 22, 1992 |
| Grant date | Oct 4, 1994 |
| Priority date | — |
| Expiry date | Sep 22, 2012 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB65H2515/50
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A printed sheet constituting a reference is scanned to form an image of a predetermined part of the sheet, and this reference image is stored in a microprocessor. Additional printed sheets which are to undergo further processing are subsequently similarly scanned to form images of predetermined parts thereof which, as regards position, correspond at least approximately to the predetermined part of the reference sheet. The predetermined part of the reference sheet may be larger than the predetermined parts of the additional sheets or vice versa so that the reference image is larger than the other images or vice versa. The microprocessor compares the image of each additional sheet with that of the reference sheet. In comparing two images, the microprocessor searches the larger image to determine the relative position in which the images would be most closely matched if superimposed on one another. The microprocessor then generates a signal representative of the difference between the two images in such relative position. The magnitude of the signal indicates whether an additional sheet is identical to the reference sheet and should be further processed or whether the additional sheet…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.