US4121104A
Expired / Lapsed
US
⏱️ 0.0 years remaining
X-ray examining device with automatic timer and film container for an X-ray examining device
Assignee: US Philips Corp
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Filing: 1976-12-16
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Granted: 1978-10-17
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Expires: 1996-12-16
Abstract
Abstract X-ray examination apparatus includes means for terminating an exposure at a dose determined, in part, by the value of the tube voltage and the characteristics of the intensifying screen in use. Means are provided to read screen-identifying markings on film cassettes and to adjust the turn-off dose level in response thereto.
Inventors
- 👤 Detlev Richter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:56
CPC Classifications
G; G03; G03B; G03B42/00; G03B42/02
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
150 words
In an X-ray examining device having an X-ray source, a film container support for receiving a film container with intensifying screens and an automatic timer which comprises a measuring device for determining a measuring signal which corresponds to a radiation dose to be measured, a switch-off signal computer for generating a switch-off dose signal which corresponds to a preset radiation dose, and a comparator and switch-off device for switching-off the X-ray source when the measuring and switch-off dose signal are in agreement; the improvement wherein: the film container support includes a mark sensor for sensing a mark on a film container to be accommodated into the film container support; and an output of the mark sensor is connected to an input of the switch-off signal computer to provide a switch-off dose signal which is tuned to a preset high voltage and matched to an intensifying screen in said film container.
Claim 2
Dependent Claim
150 words
In an X-ray examining device having an X-ray source, a film container support for receiving a film container with intensifying screens and an automatic timer which comprises a measuring device for determining a measuring signal which corresponds to a radiation dose to be measured, a switch-off signal computer for generating a switch-off dose signal which corresponds to a preset radiation dose, and a comparator and switch-off device for switching-off the X-ray source when the measuring and switch-off dose signal are in agreement; the improvement wherein: the film container support includes a mark sensor for sensing a mark on a film container to be accommodated into the film container support; and an output of the mark sensor is connected to an input of the switch-off signal computer to provide a switch-off dose signal which is tuned to a preset high voltage and matched to an intensifying screen in said film container.
Claim 3
Dependent Claim
83 words
A device as claimed in claim 1, wherein the switch-off signal computer comprises a read only memory which includes a group of memory locations for each type of intensifying screen wherein the switch-off dose required for the relevant type of intensifying screen for given high voltages is stored and which forms, from the output signal of the mark sensor and a digital signal which corresponds to the preset high voltage, the address of a memory location whose content determines the switch-off dose signal.
Claim 4
Dependent Claim
22 words
The device of claim 1 further including at least one film container having marks to indicate a type of intensifying screen therewithin.
Claim 5
Dependent Claim
20 words
A device as claimed in claim 3, wherein the marks are concentric rings disposed around the center of the container.
Claim 6
Dependent Claim
19 words
A device as claimed in claim 3 wherein the marks are disposed on four borders of the film container.
Claim 7
Dependent Claim
32 words
A device as claimed in claim 3 wherein said film container includes two pairs of identical marks, each of said pairs being symetrically disposed with respect to the center of said container.
Claim 8
Dependent Claim
30 words
A device as claimed in claim 3 wherein said film container includes four identical marks each of which is disposed at the same distance from the center of the container.
Claim 9
Dependent Claim
31 words
A device as claimed in claim 3 wherein said film container includes four identical marks, the distances from each of said marks to the nearest edge of the container being equal.
Claim 10
Dependent Claim
63 words
A device as claimed in claim 1 wherein the switch-off signal computer comprises a separate, adjustable resistor network for each type of intensifying screen to be used, said networks being adjustable in response to a voltage selector, and means for connecting one of said networks, in response to an output signal from said mark sensor, to calculate the value of said switch-off dose.
Claim 11
Dependent Claim
32 words
A device as claimed in claim 1 wherein an output signal from the mark sensor is connected to block X-ray examination when a film container is absent from the film container support.
References Cited (Backward Citations)
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US3604935A
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US3725659A
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US3942016A
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US3809901A
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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) | 1981-10-16 | 1982-04-17 | 1982-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-10-16 | 1986-04-17 | 1986-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-10-16 | 1990-04-17 | 1990-10-17 | $7700.00 | Window Closed / Lapsed |