Apparatus and method for automatic digitizer fault detection
US5335230A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 12, 1991 |
| Grant date | Aug 2, 1994 |
| Priority date | — |
| Expiry date | Aug 12, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/3004
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An automatic fault detection apparatus which requires no human intervention. The apparatus includes a source for energizing the digitizer including a constant direct current source and a constant direct voltage source, and a switch for selectively coupling either the constant current source or the constant voltage source to the digitizer. An analog-to-digital converter couples to the digitizer and to the source. A controller couples to the output of the analog-to-digital converter. Switches selectively connect the source and the analog-to-digital converter to the digitizer and include analog switches controlled by the controller. A non-volatile memory couples to the controller. An indicator coupled to the controller provides information about digitizer operability. A plurality of test electrodes within the digitizer couple to the analog-to-digital converter. Finally, a wiring harness connects the analog-to-digital converter and the source to the digitizer. The apparatus couples to operative electrodes within the digitizer. The method of the present invention includes four tests for detecting faults within digitizers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.