Patent US2360557A successfully refreshed from Google Patents.
US3629499A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pattern noise reduction system
Assignee: US Philips Corp
•
Filing: 1969-07-02
•
Granted: 1971-12-21
•
Expires: 1989-07-02
Abstract
Abstract This invention relates to an apparatus and methods for reducing pattern noise in a vidicon type camera tube and particularly a vidicon camera tube system embodying a thermal detector array for viewing infrared radiation. A chopper is placed in front of the detector and switched open and shut. Thus, the vidicon target receives alternatively signal plus noise and noise alone. When receiving the noise alone, the target is overcharged above a bias level by an external source to an amount equal to the discharge due to the noise. Therefore, when the target receives signal plus noise, the noise components will subtract out.
Inventors
- 👤 Allan Ivan Carlson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:28
CPC Classifications
H; H04; H04N; H04N23/00; H04N23/80; H04N23/81; H04N23/20; H04N23/23
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
116 words
An apparatus for reducing spatial noise in a camera system operated from a bias supply to receive radiation emitted from an object comprising: a vidicon tube having a target coupled to the bias supply and disposed to receive the object radiation to discharge each point of said target, and a scanning election gun for charging each point of said target; means for interrupting the object radiation incident upon said target, and means for cancelling noise due to a spatially uneven potential across the target including means for setting the potential of each point of said target to a value corresponding to a negative of said pattern noise of the point when said object radiation is blocked.
Claim 2
Independent Claim
116 words
An apparatus for reducing spatial noise in a camera system operated from a bias supply to receive radiation emitted from an object comprising: a vidicon tube having a target coupled to the bias supply and disposed to receive the object radiation to discharge each point of said target, and a scanning election gun for charging each point of said target; means for interrupting the object radiation incident upon said target, and means for cancelling noise due to a spatially uneven potential across the target including means for setting the potential of each point of said target to a value corresponding to a negative of said pattern noise of the point when said object radiation is blocked.
Claim 3
Dependent Claim
34 words
An apparatus as defined in claim 1 wherein said setting means comprises an amplifier having an output coupled to said gun and an input coupled to said target when said object radiation is interrupted.
Claim 4
Dependent Claim
14 words
An apparatus as defined in claim 1 wherein said interrupting means comprises a chopper.
Claim 5
Dependent Claim
25 words
An apparatus as defined in claim 1 further comprising means for converting object radiation to visible light disposed between said interrupting means and said target.
Claim 6
Dependent Claim
35 words
An apparatus as defined in claim 4 wherein said converting means comprises a thermal detector array, an energy source for exciting said array, and means for turning on said source synchronized with said interrupting means.
Claim 7
Dependent Claim
17 words
An apparatus as defined in claim 5 wherein said thermal detector array is an infrared sensitive phosphor.
Claim 8
Dependent Claim
20 words
An apparatus as defined in claim 5 wherein said energy source is an ultraviolet source illuminating said thermal detector array.
Claim 9
Independent Claim
140 words
The method of reducing spatial noise in a camera tube comprising: biasing a target from a bias supply: illuminating said target from a thermal detector array whereby each point of said target will discharge by an amount corresponding to the radiation impinging upon the point from said detector; scanning said target with an electron beam to charge each point of said target over said bias level by an amount equal to said previous discharge for the point; illuminating said target and detector with radiation from a desired viewed object whereby said target will discharge; and scanning said target with an electron beam at a potential equal to said bias level whereby said target will charge up to said bias level, the charging current flowing being a signal proportional to said viewed object without spatial noise from said thermal detector array.
Claim 10
Independent Claim
140 words
The method of reducing spatial noise in a camera tube comprising: biasing a target from a bias supply: illuminating said target from a thermal detector array whereby each point of said target will discharge by an amount corresponding to the radiation impinging upon the point from said detector; scanning said target with an electron beam to charge each point of said target over said bias level by an amount equal to said previous discharge for the point; illuminating said target and detector with radiation from a desired viewed object whereby said target will discharge; and scanning said target with an electron beam at a potential equal to said bias level whereby said target will charge up to said bias level, the charging current flowing being a signal proportional to said viewed object without spatial noise from said thermal detector array.
References Cited (Backward Citations)
US2839699A
Cited
US2816954A
Cited
US2853648A
Cited
US2920137A
Cited
US2969477A
Cited
US3067283A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-20 | 1975-06-21 | 1975-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-20 | 1979-06-21 | 1979-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-20 | 1983-06-21 | 1983-12-21 | $7700.00 | Window Closed / Lapsed |