Document processing apparatus and method
US6764068B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 6, 2003 |
| Grant date | Jul 20, 2004 |
| Priority date | — |
| Expiry date | Jun 6, 2023 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB65H2701/173
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A method of detecting undesired metal objects in a document feed path and a document processing apparatus that includes a feeder for transporting document sheets along a feed path; and a detector for detecting the presence of foreign metal objects in said feed path. The detector comprises a source of alternating electrical energy connected to a conductive transmitter loop for generating a pulsed magnetic field proximate the feed path and a conductive receiver loop that receives reflected magnetic field signals. The reflected magnetic signals induce electrical signals in the receiver loop which are amplified and processed to produce output signals which are sent to a phase shift analyzer which discriminates among output signals produced in the receiver loop by magnetic reflections from metal objects of varying types to provide an output signal when an undesired metal object in the feed path is detected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.