Size or position sensing of intermixed sheets in a sheet stacking tray with sheet edge shadow detection
US5847405A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 4, 1997 |
| Grant date | Dec 8, 1998 |
| Priority date | — |
| Expiry date | Sep 4, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G2215/00329
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A non-contact optical sheet size and/or position detection system for detecting the position of at least one edge of an outside (top or bottom) document sheet stacked in a sheet stacking tray in which thin document sheets of different sizes and/or positions are stacked on top of one another; with an illumination source for illuminating the potential sheet edge areas at an angle generating detectable sheet edge shadows, and an optical detection system remotely detecting the edge shadow positions to provide sheet edge location information to a control system for the imaging or offsetting of the sheet. In a document feeder for sequentially feeding a top or bottom sheet to be imaged, the detection system may be responsive only to a moving sheet edge shadow to determine the size of the sheet being fed to be imaged relative to other sheets in the stack irrespective of intermixed different sizes of sheets in the stack. For a bottom feeder the detection may be through an elongate aperture in the tray. For an output stacking system with a system for offsetting alternately printed sets of sheets in a stacking tray the detected edge shadow(s) of the top sheet may be used to control the offset…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.