US4166237A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Horizontal deflection circuit for television camera
Assignee: Philips North America LLC
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Filing: 1975-10-20
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Granted: 1979-08-28
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Expires: 1995-10-20
Abstract
Abstract A deflection circuit has a switching transistor to switch current from a supply transistor through deflection coils. Both the base and collector current of the supply transistor are sensed to eliminate temperature variations in a linearity correction circuit. The deflection coils have series transformers coupled to them for individual linearity correction. This enables higher values of variable resistors to be used, thus eliminating contact potential problems.
Inventors
- 👤 Frederik J. Van Roessel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:36
CPC Classifications
H; H03; H03K; H03K4/00; H03K4/06; H03K4/08; H03K4/90; H04; H04N; H04N23/00; H04N23/10; H04N23/13; H04N23/15
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
118 words
A circuit for generating a deflection current in a deflection coil, said circuit comprising a current supply first transistor means adapted to be coupled to a first end of said coil and for providing for a sawtooth deflection current in said coil, said transistor having base and collector electrodes means adapted to be coupled to a second end of said coil for supplying a voltage thereto for correcting the linearity of said deflection current, and means coupled to said transistor and said correcting means for sensing the current in said base and said collector and for applying a voltage proportional to and derived from said sensed current to said correcting means; whereby the linearity correction is temperature stable.
Claim 2
Dependent Claim
118 words
A circuit for generating a deflection current in a deflection coil, said circuit comprising a current supply first transistor means adapted to be coupled to a first end of said coil and for providing for a sawtooth deflection current in said coil, said transistor having base and collector electrodes means adapted to be coupled to a second end of said coil for supplying a voltage thereto for correcting the linearity of said deflection current, and means coupled to said transistor and said correcting means for sensing the current in said base and said collector and for applying a voltage proportional to and derived from said sensed current to said correcting means; whereby the linearity correction is temperature stable.
Claim 3
Dependent Claim
50 words
A circuit as claimed in claim 1 wherein said sensing means comprises a second transistor having an emitter coupled to said first transistor collector and a collector coupled to said first transistor base, and a low value sense resistor coupled to said first transistor collector and said second transistor emitter.
Claim 4
Dependent Claim
15 words
A circuit as claimed in claim 1 wherein said correcting means comprises a class-B amplifier.
Claim 5
Dependent Claim
38 words
A circuit as claimed in claim 3 wherein said correctin means further comprises a transformer having a high impedance primary coupled to said amplifier and a lower impedance secondary adapted to be coupled to said second coil end.
Claim 6
Dependent Claim
36 words
A circuit as claimed in claim 1 further comprising said coil, a transformer having a low impedance primary series coupled to said coil and a higher impedance secondary, and a variable resistor coupled to said secondary.
Claim 7
Dependent Claim
86 words
A circuit for generating a linearity correction current in a deflection coil, said circuit comprising means for providing a deflection voltage to said coil, a low value resistor means for sensing a sawtooth current proportional to a resulting deflection current in said coil, and a class-B amplifier means separate from said deflection voltage providing means and adapted to be coupled to said coil and coupled to said resistor means for providing a linearity correction voltage to said coil; whereby said circuit uses a minimum of power.
Claim 8
Dependent Claim
86 words
A circuit for generating a linearity correction current in a deflection coil, said circuit comprising means for providing a deflection voltage to said coil, a low value resistor means for sensing a sawtooth current proportional to a resulting deflection current in said coil, and a class-B amplifier means separate from said deflection voltage providing means and adapted to be coupled to said coil and coupled to said resistor means for providing a linearity correction voltage to said coil; whereby said circuit uses a minimum of power.
Claim 9
Dependent Claim
33 words
A circuit as claimed in claim 6 further comprising a transformer having a high impedance primary coupled to said amplifier and a lower impedance secondary means adapted to be coupled to said coil.
References Cited (Backward Citations)
GB934483A
Cited
GB935722A
Cited
US3192433A
Cited
US3434002A
Cited
US3426241A
Cited
GB1215201A
Cited
US3439221A
Cited
US3646393A
Cited
GB1251850A
Cited
GB1366392A
Cited
US3769542A
Cited
US3740611A
Cited
GB1449375A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-08-27 | 1983-02-26 | 1983-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-08-27 | 1987-02-26 | 1987-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-08-27 | 1991-02-26 | 1991-08-28 | $7700.00 | Window Closed / Lapsed |