Apparatus and method for digitizer point sampling and validation

Details Apparatus and method for digitizer point sampling and validation Apparatus and method for digitizer point sampling and validation

1992-02-21

1993-07-06

Schreyer, Stafford

Telegraphy

Systems

Position coordinate determination for writing

178 19, G08C 2100

Patent

active

052256367

ABSTRACT:
An apparatus and method for digitizer sampled point validation which compares charge and discharge voltages across a capacitive element within the digitizer or a filter coupled between the digitizer and an analog-to-digital convertor to accept or reject the point. The method of the present invention detects excessive contact resistance, typically caused by insufficient actuation force. The method alternately charges and discharges the digitizer sampling circuitry to positive and negative voltage rails prior to readings. The sampling circuitry includes the layer in use, and the wire connections, all of which provide resistance and capacitance affecting the time constants for charging and discharging. The sampling circuitry also includes the filter in use, when so installed. High contact resistance due to excessive contact resistance prevents adequate charging and discharging of the sampling circuitry to the position voltage of the point and results in unequal values for the two readings. A comparison of the two values shows conclusively whether contact resistance is too high, and therefore whether the sample is valid.

REFERENCES:
patent: 4575580 (1986-03-01), Jandrell
patent: 4680429 (1987-07-01), Murdock et al.
patent: 4819194 (1989-04-01), Koizumi et al.

Affiliated with

Also associated with

Rating

Apparatus and method for digitizer point sampling and validation does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Apparatus and method for digitizer point sampling and validation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus and method for digitizer point sampling and validation will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1691646