US4975546A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotation and displacement sensing apparatus
Assignee: Individual
•
Filing: 1989-09-05
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Granted: 1990-12-04
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Expires: 2009-09-05
Abstract
Abstract A position sensing apparatus that can be used with a compatible digitizing tablet to generate positional and rotational information. The apparatus contains two mutually perpendicular windings which are fed with AC waveforms on phase quadrature. The magnetic field generated by these windings is detected by the digitizing tablet. Alternatively, the perpendicular coils may be used to detect an externally generated magnetic field. A further winding can be added to give positional information. All windings can be arranged in a disclosed manner, and incorporated into a hand held system.
Inventors
- 👤 Timothy R. Craig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:56
CPC Classifications
G; G06; G06F; G06F3/00; G06F3/01; G06F3/03; G06F3/041; G06F3/046; G06F2203/00; G06F2203/041; G06F2203/04101
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
178 words
A position sensing apparatus comprising: a free axis; a transmitting part, said transmitting part having a first winding and a second winding, each of said first and second windings being for generating a magnetic field, said first and second winding each having an axis with said axes of said first and second windings being mutually perpendicular to said free axis; a receiving part, said receiving part having a plurality of elongate windings for generating e.m.f.s. when subject to the magnetic fields generated by said first and second windings, and to generate an output corresponding to said e.m.f.s.; means for providing two AC waveforms in quadrature, said two AC waveforms being respectively applied to said first and second windings for causing said first and second windings to generate said magnetic field; and means for analysing said output of said receiving means so as to provide rotational information relating to said free axis, said apparatus further comprising a further coil winding arranged with its axis parallel to the free axis, thereby to generate linear positional data of said free axis.
Claim 2
Dependent Claim
178 words
A position sensing apparatus comprising: a free axis; a transmitting part, said transmitting part having a first winding and a second winding, each of said first and second windings being for generating a magnetic field, said first and second winding each having an axis with said axes of said first and second windings being mutually perpendicular to said free axis; a receiving part, said receiving part having a plurality of elongate windings for generating e.m.f.s. when subject to the magnetic fields generated by said first and second windings, and to generate an output corresponding to said e.m.f.s.; means for providing two AC waveforms in quadrature, said two AC waveforms being respectively applied to said first and second windings for causing said first and second windings to generate said magnetic field; and means for analysing said output of said receiving means so as to provide rotational information relating to said free axis, said apparatus further comprising a further coil winding arranged with its axis parallel to the free axis, thereby to generate linear positional data of said free axis.
Claim 3
Dependent Claim
20 words
A position sensing apparatus according to claim 1 wherein at least one of the windings is a single continuous coil.
Claim 4
Dependent Claim
25 words
A position sensing apparatus according to claim 1 wherein at least one of the windings is a plurality of separate axially aligned electrically connected coils.
Claim 5
Dependent Claim
49 words
A position sensing apparatus according to claim 1, further comprising: a hand held device defining said free axis, said first and second windings being fixed to said hand held device; and a surface adjacent said receiving part, said hand held device having a contact part for contacting said surface.
Claim 6
Dependent Claim
73 words
A position sensing apparatus according to claim 4 wherein said hand held device is elongate with a longitudinal axis corresponding to said free axis, and the position of intersection of said longitudinal axis device and said axes of said first and second windings is adjustable in relation to the rest of the hand held device to control the resolved rotational error when the longitudinal axis is displaced from being perpendicular to said surface.
Claim 7
Dependent Claim
35 words
A position sensing apparatus according to claim 1 wherein said analysing means is arranged to demodulate and integrate said output of the receiving part, the resultant D.C. component being available for conversion to computer data.
Claim 8
Dependent Claim
34 words
A position sensing apparatus according to claim 1 wherein said analysing means is arranged to differentiate the output of said receving part thereby to derive an angular velocity or angular acceleration of the windings.
Claim 9
Dependent Claim
158 words
A position sensing apparatus comprising: a free axis; a transmitting part having a plurality of elongate windings for generating a magnetic field; a receiving part having a first winding and a second winding, each of said first and second windings being for generating e.m.f.s. when subject to said magnetic field and for generating outputs corresponding to said magnetic fields, said first and second windings each having an axis with said axes of said first and second windings being mutually perpendicular to said free axis; means for applying two AC waveforms in quadrature to said elongate windings of said transmitting part for causing said elongate windings to generate said magnetic fields; and means for analysing said outputs of said receiving part so as to provide rotational information relating to said free axis; said apparatus further comprising a further coil winding arranged with its axis parallel to the free axis, thereby to generate linear positional data of said free axis.
Claim 10
Dependent Claim
158 words
A position sensing apparatus comprising: a free axis; a transmitting part having a plurality of elongate windings for generating a magnetic field; a receiving part having a first winding and a second winding, each of said first and second windings being for generating e.m.f.s. when subject to said magnetic field and for generating outputs corresponding to said magnetic fields, said first and second windings each having an axis with said axes of said first and second windings being mutually perpendicular to said free axis; means for applying two AC waveforms in quadrature to said elongate windings of said transmitting part for causing said elongate windings to generate said magnetic fields; and means for analysing said outputs of said receiving part so as to provide rotational information relating to said free axis; said apparatus further comprising a further coil winding arranged with its axis parallel to the free axis, thereby to generate linear positional data of said free axis.
Claim 11
Dependent Claim
49 words
A position sensing apparatus according to claim 8 further comprising; a hand held device defining said free axis, said first and second windings being fixed to said hand held device; and a surface adjacent said receiving part, said hand held device having a contact part for contacting said surface.
Claim 12
Dependent Claim
73 words
A position sensing apparatus according to claim 9 wherein said hand held device is elongate with a longitudinal axis corresponding to said free axis, and the position of intersection of said longitudinal axis device and said axes of said first and second windings is adjustable in relation to the rest of the hand held device to control the resolved rotational error when the longitudinal axis is displaced from being perpendicular to said surface.
References Cited (Backward Citations)
US3876831A
Cited
US4289927A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-12-03 | 1994-06-04 | 1994-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-03 | 1998-06-04 | 1998-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-03 | 2002-06-04 | 2002-12-04 | $7700.00 | Window Closed / Lapsed |