Patent US2736260A successfully refreshed from Google Patents.
US3801741A
Expired / Lapsed
US
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Feature selection in image analysis
Assignee: Image Analysing Computers Ltd
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Filing: 1972-04-28
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Granted: 1974-04-02
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Expires: 1992-04-28
Abstract
Abstract Circuit arrangements are described by which a signal from a socalled light pen is employed to gate the output from a threshold detector set to detect amplitude excursions of a video signal which exceed a reference voltage. In this way the detected signal pulses corresponding to a feature towards which the light pen is pointed, alone, are released and measurements may be made thereon to provide information about the selected feature. A preferred form of light pen is described in which switch means is provided by which it is possible to select which of a plurality of stores is to be supplied with the information obtained about any feature. In this way operator controlled pattern recognition may be performed.
Inventors
- 👤 R Ablett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 05:39
CPC Classifications
G; G06; G06T; G06T7/00; G06T7/60; G06F; G06F3/00; G06F3/01; G06F3/03; G06F3/033; G06T1/00; G06T1/0007
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
144 words
A circuit arrangement for selecting a feature by means of a light pen from a picture displayed on a c.r.t. employing line scanning comprising, in combination with a light pen, first circuit means for recirculating at approximately line scan period intervals an electrical pulse generated by the light pen, a threshold detector for generating intersect pulses from detected amplitude excursions of the video signal displayed on the c.r.t., second circuit means for sensing coincidence between a generated pulse and an intersect pulse occuring during one of the scan lines of the displayed picture and further gating means for releasing at least the coincident portion of the intersect pulse and at least the coincident portion of each intersect pulse arising on a subsequent line scan which is at least in part coincident with a signal released by said further means on the preceding line scan.
Claim 2
Dependent Claim
144 words
A circuit arrangement for selecting a feature by means of a light pen from a picture displayed on a c.r.t. employing line scanning comprising, in combination with a light pen, first circuit means for recirculating at approximately line scan period intervals an electrical pulse generated by the light pen, a threshold detector for generating intersect pulses from detected amplitude excursions of the video signal displayed on the c.r.t., second circuit means for sensing coincidence between a generated pulse and an intersect pulse occuring during one of the scan lines of the displayed picture and further gating means for releasing at least the coincident portion of the intersect pulse and at least the coincident portion of each intersect pulse arising on a subsequent line scan which is at least in part coincident with a signal released by said further means on the preceding line scan.
Claim 3
Dependent Claim
35 words
Circuit arrangement set forth in claim 1 further comprising third circuit means responsive to coincidence of an intersect pulse and a generated pulse, which on detecting coincidence, inhibits the further recirculation of the generated pulse.
Claim 4
Dependent Claim
49 words
Circuit arrangement set forth in claim 1 in which the gating means which releases the first and subsequent intersect pulses for the selected feature employs each such intersect pulse as a gating signal to release some or all of any intersect pulse coincident therewith on the next line scan.
Claim 5
Dependent Claim
42 words
Circuit arrangement set forth in claim 1 further comprising, third circuit means adapted to open the gating means for each succeeding line scan earlier in time than if the intersect pulse from the preceding line alone were employed to control the gate.
Claim 6
Dependent Claim
42 words
Circuit arrangement set foRth in claim 1 wherein the intersect pulses released, gate the video signal whereby the amplitude variations of the video signal arising from scanning the selected feature may be isolated from those corresponding to the remainder of the field.
Claim 7
Dependent Claim
31 words
Circuit arrangement set forth in claim 1 further comprising a bistable device which is set by a generated pulse and is only reset at the end of a complete field scan.
Claim 8
Dependent Claim
32 words
Circuit arrangement set forth in claim 6 further comprising a monostable device which generates the said generated pulse from the leading edge of the set condition output signal of the bistable device.
Claim 9
Dependent Claim
35 words
A circuit arrangement as set forth in claim 1 wherein the c.r.t. is of the so-called dual phosphor type, one component of which emits visible light and the other of which emits ultra violet light.
Claim 10
Dependent Claim
26 words
A circuit arrangement as set forth in claim 8 wherein the light pen is substantially insensitive to visible light and is sensitive to ultra violet light.
Claim 11
Dependent Claim
91 words
A circuit arrangement for selecting a feature by means of a light pen from a picture displayed on a c.r.t. employing line scanning and thereby releasing electrical signals relating to the selected feature alone, comprising, in combination, at least one computer means for computing a value for a parameter of the specific feature from the released signals relating thereto, at least two accumulating signal storage means for storing computed value signals from the computer means and selection switch means for selecting one of the stores for storing a computed value signal.
Claim 12
Dependent Claim
91 words
A circuit arrangement for selecting a feature by means of a light pen from a picture displayed on a c.r.t. employing line scanning and thereby releasing electrical signals relating to the selected feature alone, comprising, in combination, at least one computer means for computing a value for a parameter of the specific feature from the released signals relating thereto, at least two accumulating signal storage means for storing computed value signals from the computer means and selection switch means for selecting one of the stores for storing a computed value signal.
Claim 13
Dependent Claim
40 words
A circuit arrangement as set forth in claim 10 wherein the electrical signals relating to the feature ar the amplitude variations of the video signal obtained from scanning an image of the field containing the feature, by a television camera.
Claim 14
Dependent Claim
49 words
A circuit arrangement as set forth in claim 10 wherein the electrical signals relating to a feature are the electrical pulses forming a so-called detected signal obtained by threshold detecting the amplitude variations of the video signal obtained by scanning the field or an image thereof, containing the feature.
Claim 15
Dependent Claim
27 words
A circuit arrangement as set forth in claim 10 further comprising push button means on the light pen for controlling the operation of said selection switch means.
Claim 16
Dependent Claim
23 words
A circuit arrangement as set forth in claim 10 further comprising foot operated means for controlling the operation of said selection switch means.
Claim 17
Dependent Claim
26 words
A circuit arrangement as set forth in claim 10 further comprising push button means adjacent the c.r.t. for controlling the operation of said selection switch means.
Claim 18
Dependent Claim
95 words
A light pen for use with a circuit arrangement as set forth in claim 10 comprising, in combination, a photosensitive device, means for focussing light emitted by a c.r.t. onto the photosensitive device, a tubular body member housing the photosensitive device and the focussing means, cable means for transmitting electrical signals generated by the photo-sensitive device in response to light falling thereon to release electrical signals relating to the selected feature to the computer means, and switch means located on the light pen body for selectively connecting the computer output to one of the stores.
References Cited (Backward Citations)
US3579249A
Cited
US3758717A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-01 | 1977-10-01 | 1978-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-01 | 1981-10-01 | 1982-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-01 | 1985-10-01 | 1986-04-02 | $7700.00 | Window Closed / Lapsed |