Patent US4223253A successfully refreshed from Google Patents.
US4223253A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Focusing system for color TV camera
Assignee: RCA Corp
•
Filing: 1978-12-18
•
Granted: 1980-09-16
•
Expires: 1998-12-18
Abstract
Abstract The focusing system for a multi-pickup tube color television camera includes a main focus coil and a vernier focus coil about each pickup tube. The main focus coils are coupled in series to a common source and the vernier focus coils are independently controllable.
Inventors
- 👤 Sidney L. Bendell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 16:25
CPC Classifications
H; H04; H04N; H04N23/00; H04N23/10; H04N23/13
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
147 words
A focusing system for color television camera having a plurality of image pickup tubes wherein associated with each tube is a yoke assembly, comprising: a plurality of main focus coils with a main focus coil mounted on the yoke assembly about each pickup tube, said main focus coils being connected in series to a common regulated current supply, each of said main focus coils providing the bulk of the focus field for each pickup tube, a plurality of separate vernier focus coils with a separate vernier focus coil mounted on the yoke assembly about each image pickup tube and means for applying to each vernier coil a separate low power, low voltage adjustable current whereby only a small amount of the total required focus field is provided via the vernier fields so that electronic focusing may be provided using a low voltage source without the stability problems.
Claim 2
Dependent Claim
147 words
A focusing system for color television camera having a plurality of image pickup tubes wherein associated with each tube is a yoke assembly, comprising: a plurality of main focus coils with a main focus coil mounted on the yoke assembly about each pickup tube, said main focus coils being connected in series to a common regulated current supply, each of said main focus coils providing the bulk of the focus field for each pickup tube, a plurality of separate vernier focus coils with a separate vernier focus coil mounted on the yoke assembly about each image pickup tube and means for applying to each vernier coil a separate low power, low voltage adjustable current whereby only a small amount of the total required focus field is provided via the vernier fields so that electronic focusing may be provided using a low voltage source without the stability problems.
Claim 3
Dependent Claim
35 words
The combination claimed in claim 1 wherein the separate vernier focus coils are wound directly on the inner surface of the yoke assembly and the main focus coil is wound directly upon the vernier coil.
Claim 4
Dependent Claim
29 words
The combination claimed in claim 1 wherein said vernier coil is a single layer of fine wire and the main coil comprises several layers of relatively large diameter wire.
Claim 5
Dependent Claim
44 words
The combination claimed in claim 1 wherein said tubes each have a focus cylinder electrode and a field mesh electrode and means for applying biasing voltages to said electrodes such that the ratio of the focus cylinder and field mesh voltages are maintained constant.
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) | 1983-09-16 | 1984-03-17 | 1984-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-16 | 1988-03-17 | 1988-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-16 | 1992-03-17 | 1992-09-16 | $7700.00 | Window Closed / Lapsed |