US4013878A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for an iterative determination of the variation of a function in a plane
Assignee: US Philips Corp
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Filing: 1975-09-16
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Granted: 1977-03-22
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Expires: 1995-09-16
Abstract
Abstract A device for iterative determination of the absorption distribution from the measuring values obtained by means of a scanner, which utilizes a storage tube whereon a charge image is stored which represents the distribution in a rough approximation. This charge image is read along strips whose orientation corresponds to that of the scanning during the measurement and is compared with the measuring values stored in a store. If a difference is detected, the charge on the charge strip is changed accordingly.
Inventors
- 👤 Wolfgang Wagner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 00:35
CPC Classifications
G; G11; G11C; G11C27/00; G06; G06E; G06E3/00; G06E3/001
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
164 words
A device for an iterative determination of the surfacewise distribution of a function which is derived from measuring values obtained by scanning a plane of measurement along a plurality of substantially parallel strips, and wherein the resulting primary integral values associated with each strip, are stored in a first store, comprising: a read-write storage cathode ray tube having a charge storing target whereon is stored a charge image of the distribution of the function obtained during a first approximation; means for integrating output signals from the target during the reading operation of the tube; means for sampling the integral signal from the integrating means according to the length of respective scanning strips and for holding the sampled integral values; differential means for comparing the sampled integral values with corresponding primary integral values retrieved from said first store; and control means for adjusting the density of charges in each scanning strip on said target in response and proportionally to the variations of the difference signal.
Claim 2
Independent Claim
164 words
A device for an iterative determination of the surfacewise distribution of a function which is derived from measuring values obtained by scanning a plane of measurement along a plurality of substantially parallel strips, and wherein the resulting primary integral values associated with each strip, are stored in a first store, comprising: a read-write storage cathode ray tube having a charge storing target whereon is stored a charge image of the distribution of the function obtained during a first approximation; means for integrating output signals from the target during the reading operation of the tube; means for sampling the integral signal from the integrating means according to the length of respective scanning strips and for holding the sampled integral values; differential means for comparing the sampled integral values with corresponding primary integral values retrieved from said first store; and control means for adjusting the density of charges in each scanning strip on said target in response and proportionally to the variations of the difference signal.
Claim 3
Dependent Claim
57 words
A device as claimed in claim 1, wherein the cathode ray tube device comprises a single storage tube whose writing beam intensity is controlled by said control means, and means for switching over the voltage between cathode and target from a higher value to a lower value in accordance with the polarity of the difference signal value.
Claim 4
Dependent Claim
66 words
A device as claimed in claim 1, wherein the cathode ray tube device comprises two storage tubes, the deflection systems of which are synchronously controlled with respect to each other, the electron beam of the one storage tube being modulated by the positive difference signal and the electron beam of the other storage tube being modulated by the negative difference signals applied via an inverting stage.
Claim 5
Dependent Claim
79 words
A device as claimed in claim 1, wherein the cathode ray tube device comprises a video display tube and a photo tube, the electron beam of the video display tube being modulated by the difference signal, the photo tube being optically coupled to the display screen of the video display tube, the polarity of the direct voltage applied to the outer electrodes of the photo tube being reversible in accordance with the polarity of the applied difference signal values.
Claim 6
Dependent Claim
41 words
A device as calimed in claim 1, wherein said control means comprises a multiplier circuit which multiplies the difference signal by a numerical value which is proportional to the reciprocal value of the length of respective scanning strips on the target.
Claim 7
Dependent Claim
29 words
A device as claimed in claim 1, further comprising a zero detector for erasing charges on a strip on the target when the associated primary integral value is zero.
Claim 8
Dependent Claim
44 words
A device as claimed in claim 1, wherein an additional store is provided for storing the charge image between two iteration steps, the primary integral values in the first store being replaced by the difference signal values, and the charge image being subsequently erased.
Claim 9
Dependent Claim
57 words
A device as claimed in claim 7, further comprising a second multiplier circuit which multiplies the difference signal values read from the first store by an even factor which is larger that 1, a third multiplier circuit being provided for multiplying the signals to be stored in the additional store by the reciprocal value of this factor.
Claim 10
Dependent Claim
44 words
A device as claimed in claim 1, wherein a plurality of groups of primary integral values are derived by scanning the plane of measurement from different directions, said control means adjusting the scanning of the target to the direction of scanning of each group.
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) | 1980-03-21 | 1980-09-20 | 1981-03-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-03-21 | 1984-09-20 | 1985-03-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-03-21 | 1988-09-20 | 1989-03-22 | $7700.00 | Window Closed / Lapsed |