Patent US5171232B1 successfully refreshed from Google Patents.
US4173720A
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US
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Method and apparatus for image construction
Assignee: Optische Industrie de Oude Delft NV
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Filing: 1977-05-09
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Granted: 1979-11-06
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Expires: 1997-05-09
Abstract
Abstract A tomogram is constructed from a plurality of profiles by means of back projection, the effect of the point spread function being eliminated by analog convolution with a suitable one- or two-dimensional function.
Inventors
- 👤 Ronald J. Geluk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:32
CPC Classifications
A; A61; A61B; A61B6/00; A61B6/42; A61B6/4208; A61B6/4225; G; G06; G06E; G06E3/00; G06E3/001; Y; Y10; Y10S; Y10S378/00; Y10S378/901
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
90 words
A method of constructing at least one tomogram from a plurality of profiles by means of back projection, characterized in that analog convolution with a suitable function is applied and being further characterized in that line images derived from the profiles are reproduced, summed, by means of back projection on a cathode ray tube having a presisting screen; that the residual image is convolved analogly by means of a luminance amplifier provided with deflection coils with a function F(x,y) established in at least one mask disposed behind said luminance amplifier.
Claim 2
Independent Claim
90 words
A method of constructing at least one tomogram from a plurality of profiles by means of back projection, characterized in that analog convolution with a suitable function is applied and being further characterized in that line images derived from the profiles are reproduced, summed, by means of back projection on a cathode ray tube having a presisting screen; that the residual image is convolved analogly by means of a luminance amplifier provided with deflection coils with a function F(x,y) established in at least one mask disposed behind said luminance amplifier.
Claim 3
Dependent Claim
19 words
A method according to claim 1, characterized in that the profiles are made logarithmic prior to the back projection.
Claim 4
Dependent Claim
21 words
A method according to claim 2, characterized in that the summation of the line images takes place in a scan convertor.
Claim 5
Dependent Claim
24 words
A method according to claim 3, characterized in that the line images are formed by means of electron-optical means coacting with the scan convertor.
Claim 6
Dependent Claim
19 words
A method according to claim 1, characterized in that the line images are made logarithmic prior to being summed.
Claim 7
Dependent Claim
21 words
A method according to claim 5, characterized in that the summation of the line images takes place in a scan convertor.
Claim 8
Dependent Claim
44 words
A method according to claim 1 characterized in that the intensity of the writing beam of the cathode ray tube is modulated such that the luminance variation occurring during the writing of the image on the screen of the cathode ray tube is compensated.
Claim 9
Dependent Claim
23 words
A method according to claim 7, characterized in that the input signal of the cathode ray tube is multiplied by a correction signal.
Claim 10
Independent Claim
95 words
A method of constructing at least one tomogram from a plurality of profiles by means of back projection, characterized in that analog convolution with a suitable function is applied and being further characterized in that profiles are written on the persisting screen of a cathode ray tube; that the written profiles are convolved analogly by means of a luminance amplifier provided with deflection coils with a function F(x) established in at least one mask disposed behind the luminance amplifier; and that the required tomogram is formed from the convolved profiles by means of back projection.
Claim 11
Independent Claim
95 words
A method of constructing at least one tomogram from a plurality of profiles by means of back projection, characterized in that analog convolution with a suitable function is applied and being further characterized in that profiles are written on the persisting screen of a cathode ray tube; that the written profiles are convolved analogly by means of a luminance amplifier provided with deflection coils with a function F(x) established in at least one mask disposed behind the luminance amplifier; and that the required tomogram is formed from the convolved profiles by means of back projection.
Claim 12
Dependent Claim
27 words
A method according to claim 9, characterized in that the profiles are made logarithmic before the writing on the screen of a cathode ray tube takes place.
Claim 13
Dependent Claim
32 words
A method according to claim 9, characterized in that electric signals are formed corresponding to line images associated with the profiles by means of a hold circuitry with a suitable hold period.
Claim 14
Dependent Claim
30 words
A method according to claim 9, characterized in that during one revolution of the body to be examined, the profiles of more than one section of the body are convolved.
Claim 15
Dependent Claim
27 words
A method according to claim 12, characterized in that a separate scan converter is applied for the back projection of the convolved profiles associated with each section.
Claim 16
Dependent Claim
48 words
A method according to claim 13, characterized in that the convolved profiles are temporarily written in a memory and that the tomogram associated with each section is each time formed by supplying to a scan convertor the written, convolved profiles from the memory associated with the respective section.
Claim 17
Dependent Claim
33 words
A method according to claim 12, characterized in that for the back projection of profiles associated with a plurality of sections, use is made of a memory means and a single scan convertor.
Claim 18
Dependent Claim
44 words
A method according to claim 9, characterized in that the intensity of the writing beam of the cathode ray tube is modulated such that the luminance variation occurring during the writing of a profile on the screen of the cathode ray tube is compensated.
Claim 19
Dependent Claim
27 words
A method according to claim 16, characterized in that the input signal of the cathode ray tube associated with a profile is multiplied by a correction signal.
Claim 20
Independent Claim
95 words
An apparatus for constructing at least one tomogram from a plurality of profiles by means of back projection, characterized by an X-ray television circuit 4 for picking up the profiles; a scan convertor 6 connected to the output of said circuit having deflection coils 7; a cathode ray tube 9 connected to the output of the scan converter 6 having a persisting screen; an analogous convolution apparatus 10-18 for the analog convolution of the residual image of the cathode ray tube with a two-dimensional convolution function F(x,y) established in one or more masks 12, 13.
Claim 21
Independent Claim
95 words
An apparatus for constructing at least one tomogram from a plurality of profiles by means of back projection, characterized by an X-ray television circuit 4 for picking up the profiles; a scan convertor 6 connected to the output of said circuit having deflection coils 7; a cathode ray tube 9 connected to the output of the scan converter 6 having a persisting screen; an analogous convolution apparatus 10-18 for the analog convolution of the residual image of the cathode ray tube with a two-dimensional convolution function F(x,y) established in one or more masks 12, 13.
Claim 22
Dependent Claim
24 words
An apparatus according to claim 18, characterized by a logarithmation device L connected between the X-ray television circuit (4) and the scan convertor (6).
Claim 23
Dependent Claim
19 words
An apparatus according to claim 18, characterized by electronoptical means coacting with the scan convertor for forming line images.
Claim 24
Dependent Claim
26 words
An apparatus according to claim 18 characterized by a ramp signal generator which is connected to the input of the cathode ray tube through a modulator.
Claim 25
Independent Claim
132 words
An apparatus for constructing at least one tomogram from a plurality of profiles by means of back projection, characterized by an X-ray television circuit 4 for picking up the profiles; a scan convertor 6 connected to the output of said circuit; a cathode ray tube 9 connected to the output of said scan convertor an analog convolution apparatus 10-18 in succession to the cathode ray tube for the analog convolution of the profiles written on the screen of the cathode ray tube with a one-dimensional convolution function F(x) established in one or more masks 12, 13; a memory 21 and processing apparatus 19, 20 connected to the output of the convolution apparatus; and being further characterized by a logarithmation device connected between the X-ray television circuit (4) and the scan convertor (6).
Claim 26
Independent Claim
132 words
An apparatus for constructing at least one tomogram from a plurality of profiles by means of back projection, characterized by an X-ray television circuit 4 for picking up the profiles; a scan convertor 6 connected to the output of said circuit; a cathode ray tube 9 connected to the output of said scan convertor an analog convolution apparatus 10-18 in succession to the cathode ray tube for the analog convolution of the profiles written on the screen of the cathode ray tube with a one-dimensional convolution function F(x) established in one or more masks 12, 13; a memory 21 and processing apparatus 19, 20 connected to the output of the convolution apparatus; and being further characterized by a logarithmation device connected between the X-ray television circuit (4) and the scan convertor (6).
Claim 27
Independent Claim
110 words
An apparatus for constructing at least one tomogram from a plurality of profiles by means of back projection, characterized by an X-ray television circuit 4 for picking up the profiles; a cathode ray tube 9 connected to the output of said circuit; an analog convolution apparatus 10-18 in succession to the cathode ray tube for the analog convolution of the profiles written on the screen of the cathode ray tube with a one-dimensional convolution function F(x) established in one or more masks 12, 13; a memory and processing apparatus connected to the output of the convolution apparatus; and being further characterized in that the processing apparatus comprises a scan converter.
Claim 28
Independent Claim
110 words
An apparatus for constructing at least one tomogram from a plurality of profiles by means of back projection, characterized by an X-ray television circuit 4 for picking up the profiles; a cathode ray tube 9 connected to the output of said circuit; an analog convolution apparatus 10-18 in succession to the cathode ray tube for the analog convolution of the profiles written on the screen of the cathode ray tube with a one-dimensional convolution function F(x) established in one or more masks 12, 13; a memory and processing apparatus connected to the output of the convolution apparatus; and being further characterized in that the processing apparatus comprises a scan converter.
Claim 29
Dependent Claim
19 words
An apparatus according to claim 23, characterized by electronoptical means associated with the scan convertor for forming line images.
Claim 30
Dependent Claim
22 words
An apparatus according to claim 23, characterized by a hold circuitry in succession to the analog convolution apparatus for forming line images.
Claim 31
Dependent Claim
15 words
An apparatus according to claim 23, characterized in that the memory is a video recorder.
Claim 32
Dependent Claim
26 words
An apparatus according to claim 25, characterized by a ramp signal generator which is connected to the input of the cathode ray tube through a modulator.
Claim 33
Dependent Claim
26 words
An apparatus according to claim 22 characterized by a ramp signal generator which is connected to the input of the cathode ray tube through a modulator.
Claim 34
Dependent Claim
44 words
A method according to claim 2, characterized in that the intensity of the writing beam of the cathode ray tube is modulated such that the luminance variation occuring during the writing of the image on the screen of the cathode ray tube is compensated.
Claim 35
Dependent Claim
44 words
A method according to claim 3, characterized in that the intensity of the writing beam of the cathode ray tube is modulated such that the luminance variation occurring during the writing of the image on the screen of the cathode ray tube is compensated.
Claim 36
Dependent Claim
44 words
A method accoring to claim 4, characterized in that the intensity of the writing beam of the cathode ray tube is modulated such that the luminance variation occurring during the writing of the image on the screen of the cathode ray tube is compensated.
Claim 37
Dependent Claim
44 words
A method accoring to claim 5, characterized in that the intensity of the writing beam of the cathode ray tube is modulated such that the luminance variation occurring during the writing of the image on the screen of the cathode ray tube is compensated.
Claim 38
Dependent Claim
44 words
A method according to claim 6, characterized in that the intensity of the writing beam of the cathode ray tube is modulated such that the luminance variation occurring during the writing of the image on the screen of the cathode ray tube is compensated.
References Cited (Backward Citations)
US4023036A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-11-05 | 1983-05-07 | 1983-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-11-05 | 1987-05-07 | 1987-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-11-05 | 1991-05-07 | 1991-11-06 | $7700.00 | Window Closed / Lapsed |