US3831058A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device comprising a television camera tube and television camera
Assignee: Individual
•
Filing: 1973-04-26
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Granted: 1974-08-20
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Expires: 1993-04-26
Abstract
Abstract A device including a television camera tube provided with an electron gun, a focusing gun and a photoconductive layer. The television camera tube has a beam current inertia which is as small as possible. For that purpose, the current density of the electron beam in the electron gun during scanning at any point along the axis between the cathode and the anode is at most three times the current density at the point of intersection of the axis with the cathode. The anode preferably is supplied with a voltage of at most 125 volts. A television camera tube for such a device preferably comprises a grid between the cathode and the anode having an aperture which has a diameter which is at least 20 times as large as the aperture in the anode.
Inventors
- 👤 Roosmalen J Van
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:59
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/46; H01J29/56; H01J31/00; H01J31/08; H01J31/26; H01J31/28; H01J31/34; H01J31/38
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
153 words
In combination a television camera tube, said tube comprising, aligned along an axis, an electron gun having a cathode and an anode which is provided with an aperture of given cross-section for producing an electron beam, a focusing lens for focusing the electron beam, a signal plate, a photoconductive layer on the signal plate, means to project an optical image on said photoconductive layer to form a potential distribution corresponding to said optical image, means to scan said signal plate with said electron beam to produce electric signals corresponding to the said optical image, and means to apply potentials to said cathode and anode which produce a substantially homogeneous electric field therebetween whereby during scanning the current density of the electron beam at any point along the axis between the cathode and the anode, is at most three times the current density at the point of intersection of the axis with the cathode.
Claim 2
Dependent Claim
153 words
In combination a television camera tube, said tube comprising, aligned along an axis, an electron gun having a cathode and an anode which is provided with an aperture of given cross-section for producing an electron beam, a focusing lens for focusing the electron beam, a signal plate, a photoconductive layer on the signal plate, means to project an optical image on said photoconductive layer to form a potential distribution corresponding to said optical image, means to scan said signal plate with said electron beam to produce electric signals corresponding to the said optical image, and means to apply potentials to said cathode and anode which produce a substantially homogeneous electric field therebetween whereby during scanning the current density of the electron beam at any point along the axis between the cathode and the anode, is at most three times the current density at the point of intersection of the axis with the cathode.
Claim 3
Dependent Claim
26 words
The combination as claimed in claim 1, wherein a potential is applied to the anode which is at most 125 volt positive relative to the cathode.
Claim 4
Dependent Claim
49 words
The combination as claimed in claim 2, wherein the electron gun includes a grid between the cathode and the anode, said grid having an aperture which has a diameter at an area of minimum cross-section at least 20 times as large as that of the aperture in the anode.
Claim 5
Dependent Claim
30 words
The combination as claimed in claim 3, wherein the aperture in the anode on the side of the grid has a larger diameter than at the area of minimum cross-section.
Claim 6
Dependent Claim
49 words
The combination as claimed in claim 4, wherein the anode comprises a substantially circular cylindrical part defining an aperture having an area of minimum cross-section and a substantially circular cylindrical part on the side facing the grid defining an aperture having an area of larger cross-section than said minimum.
Claim 7
Dependent Claim
20 words
The combination as claimed in claim 5, wherein the cathode beam current density during scanning is at least 0.5 A/sq.cm.
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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) | 1977-08-19 | 1978-02-18 | 1978-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-19 | 1982-02-18 | 1982-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-19 | 1986-02-18 | 1986-08-20 | $7700.00 | Window Closed / Lapsed |