Patent US2527420A successfully refreshed from Google Patents.
US3835247A
Expired / Lapsed
US
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Field illumination for image analysis
Assignee: Image Analysing Computers Ltd
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Filing: 1972-05-11
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Granted: 1974-09-10
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Expires: 1992-05-11
Abstract
Abstract The invention provides methods and apparatus whereby feature information in each of a number of successive images may be analysed. In particular continuous relative movement between the specimen and image device is provided for thereby eliminating the settlement times characteristic of systems employing intermittent relative movement between specimen and imaging device. The invention envisages the use of a gas discharge tube light source and proposes the insertion of a light diffusing device between the light source and specimen to reduce errors due to movement of the shading pattern caused by movement of the arc from flash to flash. The invention also provides means for sensing the light output and/or illumination level of the field to control the light output from the light source to maintain this substantially constant during an analysis. The high speed of operation achieved by the invention is due to the synchronism of a flashing light source with the continuous relative movement between specimen and imaging device. The specimen may for example be mounted on a microscope stage the latter being moved relative to the optics of the microscope to present different areas for analysis. Alternatively the specimen may comprise small objects located on a conveyor belt and presented in succession to an imaging device.
Inventors
- 👤 M Soames
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:48
CPC Classifications
G; G01; G01N; G01N15/00; G01N15/10; G01N15/14; G01N15/1468
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
191 words
A method of analyzing optically distinguishable feature content in a specimen, comprising the steps of: effecting continuous, relative movement between the specimen and an imaging device in a plane perpendicular to the optical axis of the imaging device, flash illuminating at least a region of the specimen at intervals of time synchronized with said movement with a gas discharge tube light source, scanning each image of an illuminated region of the specimen to produce a video signal corresponding thereto, detecting relative to a reference voltage those amplitude excursions which relate to features, making measurements thereof, sensing the light output per flash of said gas discharge tube light source, generating a voltage whose magnitude is proportional to the light output of each flash, averaging the generated voltages so produced to produce an average value voltage, comparing the level of the generated voltage for each flash with the average value voltage, and generating a difference voltage, controlling the value of a further voltage in response to variation in the magnitude of the difference voltage and employing as the reference voltage for said video signal either said further voltage or a voltage derived therefrom.
Claim 2
Independent Claim
191 words
A method of analyzing optically distinguishable feature content in a specimen, comprising the steps of: effecting continuous, relative movement between the specimen and an imaging device in a plane perpendicular to the optical axis of the imaging device, flash illuminating at least a region of the specimen at intervals of time synchronized with said movement with a gas discharge tube light source, scanning each image of an illuminated region of the specimen to produce a video signal corresponding thereto, detecting relative to a reference voltage those amplitude excursions which relate to features, making measurements thereof, sensing the light output per flash of said gas discharge tube light source, generating a voltage whose magnitude is proportional to the light output of each flash, averaging the generated voltages so produced to produce an average value voltage, comparing the level of the generated voltage for each flash with the average value voltage, and generating a difference voltage, controlling the value of a further voltage in response to variation in the magnitude of the difference voltage and employing as the reference voltage for said video signal either said further voltage or a voltage derived therefrom.
Claim 3
Dependent Claim
135 words
The method as set forth in claim 1 wherein the imaging device forms the image of the illuminated region on a television camera tube of the Plumbicon type, the relative movement between said specimen and said imaging device and the occurrence of said illumination flashes being synchronized to the camera tube scanning, the video signal arising during the first frame scan of the camera tube target after each flash being supplied as said video signal, the specimen region being illuminated during at least part of the frame flyback period immediately preceding each said first frame scan and n frame scans of the camera tube target being performed between the end of each first frame scan and the next flash of illumination, thereby to more completely erase the residual charge pattern on the camera tube target.
Claim 4
Dependent Claim
38 words
The method as set forth in claim 1 wherein the illumination is obtained from a gas discharge tube light source, further comprising the step of diffusing the light before it is employed to illuminate a region of specimen.
Claim 5
Dependent Claim
80 words
The method as claimed in claim 1 wherein the specimen comprises a plurality of similar objects which by virtue of the relative movement are presented to the imaging device in turn, further comprising the step of sensing when each object in turn occupies a given position relative to the imaging device, generating a voltage pulse when each object in turn occupies the given position, and initiating a flash or illumination in response to the generation of each said voltage pulse.
Claim 6
Dependent Claim
40 words
The method as set forth in claim 1 further comprising the steps of generating a constant amplitude pulse from each detected amplitude excursion of duration equal to that of the detected excursion, and making measurements on said constant amplitude pulses.
Claim 7
Dependent Claim
47 words
ThE method as set forth in claim 5 further comprising the step of gating at a high frequency at least each constant amplitude pulse to replace it by a plurality of short pulses the number of which is proportional to the duration of the constant amplitude pulse.
Claim 8
Independent Claim
153 words
A method of analyzing optically distinguishable feature content in a specimen, comprising the steps of: effecting continous relative movement between the specimen and an imaging device in a plane perpendicular to the optical axis of the imaging device, flash illuminating at least a region of the specimen at intervals of time synchronized with said movement, scanning each image of an illuminated region of the specimen to produce a video signal corresponding thereto, sensing the peak white amplitude level of the video signal during the beginning of each read scan, generating a voltage whose value is proportional to the sensed amplitude level, holding said voltage for the remainder of that read scan period, controlling the duration of the light output of the flash corresponding to said read scan in dependence on the value of the generated voltage, detecting relative to a reference voltage those amplitude excursions which relate to features, and making measurements thereon.
Claim 9
Independent Claim
153 words
A method of analyzing optically distinguishable feature content in a specimen, comprising the steps of: effecting continous relative movement between the specimen and an imaging device in a plane perpendicular to the optical axis of the imaging device, flash illuminating at least a region of the specimen at intervals of time synchronized with said movement, scanning each image of an illuminated region of the specimen to produce a video signal corresponding thereto, sensing the peak white amplitude level of the video signal during the beginning of each read scan, generating a voltage whose value is proportional to the sensed amplitude level, holding said voltage for the remainder of that read scan period, controlling the duration of the light output of the flash corresponding to said read scan in dependence on the value of the generated voltage, detecting relative to a reference voltage those amplitude excursions which relate to features, and making measurements thereon.
Claim 10
Dependent Claim
46 words
The method as set forth in claim 7 further comprising the steps of generating a firing pulse to initiate said flash illumination and generating a sustain pulse having a magnitude corresponding to said held voltage to sustain each illumination for a duration dependent on said magnitude.
Claim 11
Dependent Claim
29 words
The method as set forth in claim 7 further comprising the step of averaging or smoothing the generated voltage so as to remove abrupt changes in the magnitude thereof.
Claim 12
Dependent Claim
135 words
The method as set forth in claim 7 in which the imaging device forms the image of the illuminated region on a television camera tube of the Plumbicon type, the relative movement between the specimen and the imaging device and the occurrence of illumination flashes being synchronized to the camera tube scanning, the video signal arising during the first frame scan of the camera tube target after each flash being supplied as the video signal, the specimen region being illuminated during at least part of the frame flyback period immediately preceding each said first frame scan and n frame scans of the camera tube target being performed between the end of each first frame scan and the next flash of illumination, thereby to more completely erase the residual charge pattern on the camera tube target.
Claim 13
Dependent Claim
61 words
The method as claimed in claim 7, wherein the specimen comprises a plurality of similar objects which by virtue of the relative movement presented to the imaging device in turn, further comprising the steps of sensing when each object in turn occupies a given position, and initiating a flash or illumination in response to the generation of each said voltage pulse.
Claim 14
Dependent Claim
40 words
The method as set forth in claim 7 further comprising the steps of generating a constant amplitude pulse from each detected amplitude excursion of duration equal to that of the detected excursion, and making measurements on the constant amplitude pulses.
Claim 15
Dependent Claim
47 words
The method as set forth in claim 12 further comprising the step of gating at a high frequency at least each constant amplitude pulse to replace it by a plurality of short pulses the number of which is proportional to the duration of the constant amplitude pulse.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-09 | 1978-03-11 | 1978-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-09 | 1982-03-11 | 1982-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-09 | 1986-03-11 | 1986-09-10 | $7700.00 | Window Closed / Lapsed |