Signal preconditioning for touch entry device
US4684801A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 28, 1986 |
| Grant date | Aug 4, 1987 |
| Priority date | — |
| Expiry date | Feb 28, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/941
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A touch entry system employing arrays of emitter and detector opto devices located around the periphery of an irradiated field detects intrusion of an opaque element such as a stylus within the field. The detector analog output is converted to a digital signal for input into a microprocessor. Digital signals input into the microprocessor can vary due to inconsistencies in conventional opto devices. A programmable amplifier responsive to the microprocessors preconditions the analog signals prior to analog to digital conversion to bring all digital signals corresponding to the unblocked emitter beam condition within a normalized range before input into the microprocessor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.