US5013874A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for recording and verifying handwriting, in particular signatures
Assignee: ELLETT BROTHERS A NC LP
•
Filing: 1989-03-07
•
Granted: 1991-05-07
•
Expires: 2009-03-07
Abstract
Abstract A signature verification tablet comprises two piezo-electric membranes each having a plurality of line electrodes on one side. The membranes are sandwiched together, with the line electrodes on one membrane at right angles to the line electrodes on the other. The line electrodes on each membrane are connected together in three interleaved sets, so that when a signature is written on the tablet, a series of pulses is produced containing direction and speed of movement information from which the authenticity of the signature can be verified.
Inventors
- 👤 Pieter de Bruyne
- 👤 Andre Kunz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:46
CPC Classifications
G; G06; G06F; G06F3/00; G06F3/01; G06F3/02; G06F3/0202; G06F3/03; G06F3/041; G06F3/0414; G06F3/04144; G06V; G06V10/00; G06V10/10; G06V10/12; G06V40/00; G06V40/30; G07; G07C; G07C9/00; G07C9/30; G07C9/32; G07C9/35
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
67 words
Apparatus for producing electrical signals representative of the movement of a hand-held stylus, the apparatus comprising a first piezo-electric membrane upon which the stylus is pressed during its movement, said membrane comprising a solid reference electrode on a first surface and a system of narrow and parallel linear electrodes on a second surface, characterized in that the electrodes are connected together as at least three interleaved sets.
Claim 2
Dependent Claim
67 words
Apparatus for producing electrical signals representative of the movement of a hand-held stylus, the apparatus comprising a first piezo-electric membrane upon which the stylus is pressed during its movement, said membrane comprising a solid reference electrode on a first surface and a system of narrow and parallel linear electrodes on a second surface, characterized in that the electrodes are connected together as at least three interleaved sets.
Claim 3
Dependent Claim
19 words
Apparatus according to claim 1, characterised by a respective differential amplifier connected between each pair of sets of electrodes.
Claim 4
Dependent Claim
30 words
Apparatus according to claim 1, characterized in that additional membrane layers are used each with a different spatial resolution to obtain coded information regarding the position of the moving stylus.
Claim 5
Dependent Claim
15 words
Apparatus according to claim 1 wherein said electrodes are connected together as three interleaved sets.
Claim 6
Dependent Claim
37 words
An apparatus according to claim 1 further comprising a second piezo-electric membrane disposed immediately underneath said first membrane, said second membrane comprising a system of narrow and parallel linear electrodes on an undersurface of said second membrane.
Claim 7
Independent Claim
57 words
An apparatus for producing electrical signals representative of the movement of a hand-held stylus, said apparatus comprising: a piezo-electric membrane having an under surface and an upper surface; a reference electrode on said under surface; and a plurality of interleaved sets of narrow, parallel, linear electrodes on said upper surface to indicate the movement of said stylus.
Claim 8
Independent Claim
57 words
An apparatus for producing electrical signals representative of the movement of a hand-held stylus, said apparatus comprising: a piezo-electric membrane having an under surface and an upper surface; a reference electrode on said under surface; and a plurality of interleaved sets of narrow, parallel, linear electrodes on said upper surface to indicate the movement of said stylus.
Claim 9
Dependent Claim
50 words
An apparatus according to claim 6 wherein said reference electrode covers substantially the whole of said under surface so that compression of said membrane by pressure from said stylus produces a detectable voltage difference between said reference electrode and one of said electrodes on the upper side of said membrane.
Claim 10
Dependent Claim
19 words
An apparatus according to claim 6 further comprising a hard surface disposed below the under surface of said membrane.
Claim 11
Independent Claim
55 words
An apparatus for producing electrical signals representative of the movement of a hand-held stylus, said apparatus comprising: a piezo-electric membrane having an under surface and an upper surface; a reference electrode on said under surface; and interleaved sets of narrow, parallel, linear electrodes on said upper surface which will indicate the movement of said stylus.
Claim 12
Independent Claim
55 words
An apparatus for producing electrical signals representative of the movement of a hand-held stylus, said apparatus comprising: a piezo-electric membrane having an under surface and an upper surface; a reference electrode on said under surface; and interleaved sets of narrow, parallel, linear electrodes on said upper surface which will indicate the movement of said stylus.
References Cited (Backward Citations)
US3563097A
Cited
US3808364A
Cited
US3699253A
Cited
US3991402A
Cited
US4110556A
Cited
US4234868A
Cited
US4397033A
Cited
US4475235A
Cited
US4733023A
Cited
DE3236057A1
Cited
DE3236099A1
Cited
US4484026A
Cited
US4570149A
Cited
US4653107A
Cited
US4617515A
Cited
EP0235494A1
Cited
GB2172113A
Cited
US4677259A
Cited
US4748672A
Cited
US4800240A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-05-06 | 1994-11-05 | 1995-05-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-05-06 | 1998-11-05 | 1999-05-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-05-06 | 2002-11-05 | 2003-05-07 | $7700.00 | Window Closed / Lapsed |