Media detection method and device
US6348697B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 8, 1999 |
| Grant date | Feb 19, 2002 |
| Priority date | — |
| Expiry date | Feb 8, 2019 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB65H2553/414
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A media detection method and device which can detect media precisely in spite of individual variations and mechanical assembly errors of optical sensors and contamination of light emitting and receiving parts of the optical sensors, and which, even when the medium is not yet provided, can make setting for medium detection and precisely detect the medium in a short time; wherein first, a comparison reference voltage of the differential amplifier (10) is set at 0 volts and the output of the differential amplifier (10) corresponding to the output of the optical sensor (11) is determined when or where a medium is absent; by applying the output of the differential amplifier (10) to a predetermined formula, a comparison reference voltage to be given to the differential amplifier (10) during the medium detection operation is determined; next, during the actual medium detection operation, this comparison reference voltage is applied to the differential amplifier (10) and the amplifier output is compared with a predetermined threshold to judge the presence or absence of the medium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.