US3767931A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Adjustable x-ray beam collimator with shutter for illumination of the radiation pattern
Assignee: Varian Medical Systems Inc
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Filing: 1972-11-14
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Granted: 1973-10-23
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Expires: 1992-11-14
Abstract
Abstract A shutter is provided to admit visible light into the region defined by the adjustable beam-defining components of the collimator of an X-ray apparatus. The light so admitted is reflected so as to appear to emanate from a virtual source located at the origin of the X-ray beam. The shutter is mechanically biased to remain closed, and can be opened to admit light only when no X-ray beam is being produced. Thus, the radiation pattern formed by the adjustable collimator can be simulated by visible light without the light source being located in the path of the X-ray beam. Furthermore, simulation of the radiation pattern is obtained without the shutter being open when X-ray radiation is being produced, so that radiation leakage through an open shutter is precluded.
Inventors
- 👤 N Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:51
CPC Classifications
A; A61; A61B; A61B6/00; A61B6/08; G; G21; G21K; G21K1/00; G21K1/02; G21K1/04
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
137 words
In an apparatus for irradiating an object with a beam of penetrating radiation from a source of such radiation, means for collimating said beam for impingement upon the object to be irradiated, and means for simulating the irradiation pattern of said penetrating radiation on the surface of the object to be irradiated by illumination of said surface; said collimating means comprising walls substantially opaque to said penetrating radiation and a shutter substantially opaque to said penetrating radiation disposed in a passageway through said walls; said simulation means comprising a source of illuminating radiation located externally of said walls, means disposed within said collimating means to form a virtual image of said illuminating radiation source at the location of the source of said penetrating radiation when said shutter is open, and means for opening and closing said shutter.
Claim 2
Dependent Claim
137 words
In an apparatus for irradiating an object with a beam of penetrating radiation from a source of such radiation, means for collimating said beam for impingement upon the object to be irradiated, and means for simulating the irradiation pattern of said penetrating radiation on the surface of the object to be irradiated by illumination of said surface; said collimating means comprising walls substantially opaque to said penetrating radiation and a shutter substantially opaque to said penetrating radiation disposed in a passageway through said walls; said simulation means comprising a source of illuminating radiation located externally of said walls, means disposed within said collimating means to form a virtual image of said illuminating radiation source at the location of the source of said penetrating radiation when said shutter is open, and means for opening and closing said shutter.
Claim 3
Dependent Claim
29 words
The apparatus of claim 1 wherein said source of penetrating radiation comprises a charged particle accelerator and an X-ray generating target disposed in the path of said charged particles.
Claim 4
Dependent Claim
15 words
The apparatus of claim 1 wherein said source of penetrating radiation comprises a radioactive material.
Claim 5
Dependent Claim
17 words
The apparatus of claim 1 wherein said source of illuminating radiation comprises a source of visible light.
Claim 6
Dependent Claim
17 words
The apparatus of claim 1 wherein said source of illuminating radiation comprises a source of ultra-violet radiation.
Claim 7
Dependent Claim
25 words
The apparatus of claim 1 wherein said collimating means further comprises an adjustable jaw mechanism for precisely defining the irradiation pattern of said penetrating radiation.
Claim 8
Dependent Claim
27 words
The apparatus of claim 1 wherein said shutter has a step-shaped surface corresponding to a similarly shaped aperture in said walls for receiving said shutter when closed.
Claim 9
Dependent Claim
27 words
The apparatus of claim 1 wherein said shutter is mechanically biased to remain closed and wherein said means for opening said shutter must oppose Said mechanical bias.
Claim 10
Dependent Claim
14 words
The apparatus of claim 8 wherein said mechanical bias is provided by a spring.
Claim 11
Dependent Claim
22 words
The apparatus of claim 1 wherein said virtual image forming means is an illuminating-radiation reflective member substantially transparent to said penetrating radiation.
Claim 12
Dependent Claim
32 words
The apparatus of claim 1 wherein said means for opening and closing said shutter comprises means to prevent the opening of said shutter when said beam of penetrating radiation is being generated.
Claim 13
Dependent Claim
15 words
The apparatus of claim 11 wherein said means for opening said shutter comprises solenoid means.
Claim 14
Dependent Claim
31 words
The apparatus of claim 11 wherein said means for opening and closing said shutter further comprises means to prevent said shutter from remaining open for longer than a selected time interval.
Claim 15
Dependent Claim
30 words
The apparatus of claim 2 wherein said means for opening and closing said shutter comprises means to cause said shutter to be closed whenever said source of illuminating radiation fails.
Claim 16
Dependent Claim
127 words
The apparatus of claim 1 further comprising electrical means for generating said beam of penetrating radiation, and wherein said means for opening said shutter comprises an electric circuit electrically connectable to said means for generating said beam, said circuit further comprising a time-delay relay, a first resistor, a rectifier in parallel with said first resistor, a solenoid activatable by said rectifier, a second resistor in series with said first resistor and having a higher resistance than said first resistor, a switch in parallel with said second resistor, said switch being operated by said solenoid, a primary transformer winding in parallel with said switch, a secondary transformer winding adjacent said primary winding, and said source of illuminating radiation being an electric light in series with said secondary winding.
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) | 1976-10-22 | 1977-04-23 | 1977-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-22 | 1981-04-23 | 1981-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-22 | 1985-04-23 | 1985-10-23 | $7700.00 | Window Closed / Lapsed |