Matrix encoder for sensor arrays
US4536762A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 17, 1982 |
| Grant date | Aug 20, 1985 |
| Priority date | — |
| Expiry date | May 17, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M11/26
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A meter dial register encoder employs a plurality of photoresistor sensors in a row and column matrix configuration. A microcomputer selectively scans the photoresistors to determine whether they are illuminated or non-illuminated. Each column of the row and column matrix contains a scanned photoresistor and a plurality of unscanned photoresistors operated in a two-or-three-out-of-five code, with one terminal of the scanned photoresistor being selectively connected to a 5 volt source by a microcomputer, the other terminal of the photoresistor being connected to the column conductor. The unscanned photoresistors of the column are connected between the column conductor and a separate terminal of the microcomputer held at ground potential. The column conductor is supplied to one terminal of a two terminal comparator, the other terminal of which is connected to a source of reference voltage. The photoresistors of each column thus comprise a voltage divider circuit, the output of which is monitored by the comparator. The unscanned photoresistors of each column serve as a reference for the scanned photoresistor, allowing the use of photoresistors having much greater variation in illumina…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.