US3714486A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Field emission x-ray tube
Assignee: Individual
•
Filing: 1970-10-07
•
Granted: 1973-01-30
•
Expires: 1990-10-07
Abstract
Abstract A miniature X-ray tube with D.C. power supply and a cold cathode field emission electron beam for continuous or steady state X-ray output. A tube a few centimeters in length with a needle cathode along the axis of the tube and with an exit window at the end behind the cathode for optimum X-ray output.
Inventors
- 👤 Crary J Mc
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 04:55
CPC Classifications
H; H01; H01J; H01J35/00; H01J35/02; H01J35/16; H01J35/18
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
95 words
In a tube for continuously producing X-rays by field emission, the combination of: a housing; an anode mounted in said housing; an unheated cathode mounted in said housing and spaced and electrically insulated from said anode; an X-ray transmitting window in said housing; and a high voltage DC electric power supply connected across said anode and cathode for producing by field emission, a continuous stream of electrons from said cathode to said anode producing a continuous X-ray output through said window, with the electrical impedance across said anode and cathode in excess of 1,000,000 ohms.
Claim 2
Dependent Claim
95 words
In a tube for continuously producing X-rays by field emission, the combination of: a housing; an anode mounted in said housing; an unheated cathode mounted in said housing and spaced and electrically insulated from said anode; an X-ray transmitting window in said housing; and a high voltage DC electric power supply connected across said anode and cathode for producing by field emission, a continuous stream of electrons from said cathode to said anode producing a continuous X-ray output through said window, with the electrical impedance across said anode and cathode in excess of 1,000,000 ohms.
Claim 3
Dependent Claim
95 words
In a tube for continuously producing X-rays by field emission, the combination of: a housing; an anode mounted in said housing; an unheated cathode mounted in said housing and spaced and electrically insulated from said anode; an X-ray transmitting window in said housing; and a high voltage DC electric power supply connected across said anode and cathode for producing by field emission, a continuous stream of electrons from said cathode to said anode producing a continuous X-ray output through said window, with the electrical impedance across said anode and cathode in excess of 1,000,000 ohms.
Claim 4
Dependent Claim
95 words
In a tube for continuously producing X-rays by field emission, the combination of: a housing; an anode mounted in said housing; an unheated cathode mounted in said housing and spaced and electrically insulated from said anode; an X-ray transmitting window in said housing; and a high voltage DC electric power supply connected across said anode and cathode for producing by field emission, a continuous stream of electrons from said cathode to said anode producing a continuous X-ray output through said window, with the electrical impedance across said anode and cathode in excess of 1,000,000 ohms.
Claim 5
Dependent Claim
92 words
An X-ray tube as defined in claim 1 in which said housing includes an insulating tube, an anode support ring at one end of said tube and a cathode support ring at the other end of said tube, with said anode having a generally hemispherical end and carried in said anode support ring along the axis of said tube, and with said cathode being needle shaped and carried in said cathode support ring along the axis of said insulating tube with the needle tip pointing to and spaced from the anode end.
Claim 6
Dependent Claim
33 words
An X-ray tube as defined in claim 1 in which the anode-cathode spacing is in the order of 0.2 to 2 mm. and with an anode-cathode potential in the order of 10-30 kv.
Claim 7
Dependent Claim
40 words
An X-ray tube as defined in claim 1 in which said housing is generally tubular in configuration and in the order of a few centimeters in length, and in which the anode-cathode spacing is in the order of a millimeter.
Claim 8
Dependent Claim
60 words
An X-ray tube as defined in claim 4 with said anode carried at one end and said cathode carried at the other end of said tubular housing with the electron beam from cathode to anode parallel with the longitudinal axis of said housing, and with said window disposed at said other end of said housing generally perpendicular to said axis.
References Cited (Backward Citations)
US3046439A
Cited
GB987478A
Cited
US3309523A
Cited
US3303372A
Cited
US3521073A
Cited
US3466485A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-30 | 1976-07-31 | 1977-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-30 | 1980-07-31 | 1981-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-30 | 1984-07-31 | 1985-01-30 | $7700.00 | Window Closed / Lapsed |