Patent US5488204A successfully refreshed from Google Patents.
US5488204A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Paintbrush stylus for capacitive touch sensor pad
Assignee: Synaptics Inc
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Filing: 1994-10-17
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Granted: 1996-01-30
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Expires: 2014-10-17
Abstract
Abstract A proximity sensor system includes a touch-sensor pad with a sensor matrix array having a characteristic capacitance on horizontal and vertical conductors connected to sensor pads. The capacitance changes as a function of the proximity of an object or objects to the sensor matrix. The change in capacitance of each node in both the X and Y directions of the matrix due to the approach of an object is converted to a set of voltages in the X and Y directions. These voltages are processed by circuitry to develop electrical signals representative of the centroid of the profile of the object, i.e, its position in the X and Y dimensions. Noise reduction and background level setting techniques inherently available in the architecture are employed. A conductive paintbrush-type stylus is used to produce paint-like strokes on a display associated with the touch-sensor pad.
Inventors
- 👤 Carver A. Mead
- 👤 Ralph Wolf
- 👤 Timothy P. Allen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:57
CPC Classifications
G; G06; G06F; G06F3/00; G06F3/01; G06F3/048; G06F3/0484; G06F3/0485; G06F3/04855; G06F3/03; G06F3/041; G06F3/0416; G06F3/0418; G06F3/04182; G06F3/04186; G06F3/044; G06F3/0446; G06F3/0487; G06F3/0488; G06F3/04883; G06F3/0489; G06F3/04892; G06V; G06V40/00; G06V40/20
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
48 words
A conductive paintbrush stylus for use with a capacitive touch sensor pad comprising: an electrically conductive handle; a plurality of electrically conductive bristles affixed to said handle; wherein the total resistance of said handle and said bristles is no more than the skin resistance of a human finger.
Claim 2
Dependent Claim
48 words
A conductive paintbrush stylus for use with a capacitive touch sensor pad comprising: an electrically conductive handle; a plurality of electrically conductive bristles affixed to said handle; wherein the total resistance of said handle and said bristles is no more than the skin resistance of a human finger.
Claim 3
Dependent Claim
17 words
The conductive paintbrush stylus of claim 1 wherein said total resistance is less than about 10M ohms.
Claim 4
Dependent Claim
19 words
The conductive paintbrush stylus of claim 1 wherein said plurality of electrically conductive bristles are formed from carbon fibers.
Claim 5
Dependent Claim
19 words
The conductive paintbrush stylus of claim 1 wherein said plurality of electrically conductive bristles are formed from fine wire.
Claim 6
Dependent Claim
20 words
The conductive paintbrush stylus of claim 4 wherein said plurality of electrically conductive bristles are formed from phosphor bronze wire.
Claim 7
Dependent Claim
74 words
A conductive paintbrush stylus for use with a touch sensor pad having a characteristic capacitance, said paintbrush comprising: an electrically conductive handle; a plurality of electrically conductive bristles affixed to said handle; wherein the time constant of an RC circuit comprising the total resistance of said handle and said bristles and said characteristic capacitance is less than a sampling period used to sense the presence of a conductive object on said touch sensor pad.
Claim 8
Dependent Claim
74 words
A conductive paintbrush stylus for use with a touch sensor pad having a characteristic capacitance, said paintbrush comprising: an electrically conductive handle; a plurality of electrically conductive bristles affixed to said handle; wherein the time constant of an RC circuit comprising the total resistance of said handle and said bristles and said characteristic capacitance is less than a sampling period used to sense the presence of a conductive object on said touch sensor pad.
Claim 9
Dependent Claim
19 words
The conductive paintbrush stylus of claim 6 wherein said plurality of electrically conductive bristles are formed from carbon fibers.
Claim 10
Dependent Claim
19 words
The conductive paintbrush stylus of claim 6 wherein said plurality of electrically conductive bristles are formed from fine wire.
Claim 11
Dependent Claim
20 words
The conductive paintbrush stylus of claim 8 wherein said plurality of electrically conductive bristles are formed from phosphor bronze wire.
Claim 12
Dependent Claim
23 words
The conductive paintbrush stylus of claim 6 wherein said plurality of electrically conductive bristles are affixed to said handle with a conductive adhesive.
Claim 13
Dependent Claim
112 words
A conductive paintbrush stylus for use with a touch sensor pad having a characteristic capacitance, said paintbrush comprising: a bundle of carbon fibers having a length extending substantially the length of said paintbrush stylus, a first portion of said length of said bundle impregnated with a thin insulating material to form a rigid handle, and a second portion of said length of said bundle remaining exposed to form conductive bristles; wherein the time constant of an RC circuit comprising the total resistance of said handle and said bristles and said characteristic capacitance is less than a sampling period used to sense the presence of a conductive object on said touch sensor pad.
Claim 14
Dependent Claim
112 words
A conductive paintbrush stylus for use with a touch sensor pad having a characteristic capacitance, said paintbrush comprising: a bundle of carbon fibers having a length extending substantially the length of said paintbrush stylus, a first portion of said length of said bundle impregnated with a thin insulating material to form a rigid handle, and a second portion of said length of said bundle remaining exposed to form conductive bristles; wherein the time constant of an RC circuit comprising the total resistance of said handle and said bristles and said characteristic capacitance is less than a sampling period used to sense the presence of a conductive object on said touch sensor pad.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-01-29 | 1999-07-31 | 2000-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-01-29 | 2003-07-31 | 2004-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-01-29 | 2007-07-31 | 2008-01-30 | $7700.00 | Window Closed / Lapsed |