Claims
- 1. An electronic verification machine for a document comprising:
- a sensor plate;
- an excitation plate;
- an alignment mechanism for aligning the document with said sensor plate and said excitation plate;
- signal application means for applying an AC signal to said excitation plate;
- detection means operatively connected to said sensor plate for generating a signal representing a thickness of the document.
- 2. The machine of claim 1 wherein said detection means determines the capacitance of a capacitor including said sensor plate and said excitation plate with the document serving as a dielectric between said plates.
- 3. The machine of claim 2 wherein said alignment mechanism includes a roller supporting the document against said plates and said AC signal is reflected off said roller.
- 4. The machine of claim 3 wherein said roller includes an elastomeric material having a plurality of conductive particles encapsulated therein.
- 5. The machine of claim 4 wherein said elastomeric material is rubber and said conductive particles are carbon particles.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. Ser. No. 08/837,304, filed Apr. 11, 1997, now U.S. Pat. No. 5,818,019, which was a continuation of U.S. Ser. No. 08/846,588, filed Jun. 7, 1995, now U.S. Pat. No. 5,621,200, issued Apr. 15, 1997.
US Referenced Citations (11)
Continuations (1)
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Date |
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Parent |
846588 |
Jun 1995 |
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Continuation in Parts (1)
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837304 |
Apr 1997 |
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