Patent US4710973A successfully refreshed from Google Patents.
US4710973A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Varactor diode tuner with band switched coils and lines
Assignee: Alps Alpine Co Ltd
•
Filing: 1985-12-26
•
Granted: 1987-12-01
•
Expires: 2005-12-26
Abstract
Abstract A tuner in which a band switching signal corresponding to a channel selected from a plurality of UHF and VHF bands is generated to enable the formation of a suitable resonant circuit for receiving television signals of the selected channel. It includes a varactor diode, a plurality of resonant coils and distribution constant lines which are each grounded at one end. Each of the coils and the line is provided for forming a resonant circuit for tuning one of the bands. A plurality of switching diodes are provided for connecting the other ends of the coils and the line selectively to the other end of the varactor diode. The tuner further includes a device for turning on and off the switching diodes selectively in response to the band switching signal.
Inventors
- 👤 Takeo Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:32
CPC Classifications
H; H03; H03J; H03J5/00; H03J5/24; H03J5/242; H03J5/244
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
184 words
In a tuner having a common transistor in a high-frequency amplification circuit an a common varactor diode in a local resonant circuit in which a band switching signal corresponding to a channel selected from a plurality of UHF and VHF bands applied to said tuner to form a suitable resonant circuit for receiving television signals of the selected channel, the improvement which comprises: said common varactor diode connected to ground at one end; a plurality of resonant coils each connnected to ground at one end; a distribution constant line connected to ground at one end, each of said coils and said line being provided for forming a resonant circuit with said common varactor for tuning said tuner to a respective one of said bands; a plurality of switching diodes, each switching diode having one end connected to the other end of a respective one of said coils and said line and each switching diode's other end connected to the other end of said common varactor diode; and means for turning on and off said switching diodes selectively in response to said band switching signal.
Claim 2
Dependent Claim
184 words
In a tuner having a common transistor in a high-frequency amplification circuit an a common varactor diode in a local resonant circuit in which a band switching signal corresponding to a channel selected from a plurality of UHF and VHF bands applied to said tuner to form a suitable resonant circuit for receiving television signals of the selected channel, the improvement which comprises: said common varactor diode connected to ground at one end; a plurality of resonant coils each connnected to ground at one end; a distribution constant line connected to ground at one end, each of said coils and said line being provided for forming a resonant circuit with said common varactor for tuning said tuner to a respective one of said bands; a plurality of switching diodes, each switching diode having one end connected to the other end of a respective one of said coils and said line and each switching diode's other end connected to the other end of said common varactor diode; and means for turning on and off said switching diodes selectively in response to said band switching signal.
Claim 3
Dependent Claim
21 words
A tuner as set forth in claim 1, wherein said coils and said line are connected in parallel to one another.
Claim 4
Dependent Claim
51 words
A tuner as set forth in claim 2, further including a plurality of DC cutoff capacitors, said one end connected to ground of each of said coils and said line being connected to one end of a respective one of said capacitors which is connected to ground at the other end.
Claim 5
Dependent Claim
41 words
A tuner as set forth in claim 3, further including said common transistor having a grounded base, said other ends of said coils and said line being selectively electrically connectable to the collector terminal of said transistor via respective switching diodes.
Claim 6
Dependent Claim
40 words
A tuner as set forth in claim 1, wherein said line is electrically connected to said varactor diode to form a resonant circuit for tuning an UHF channel when a respective one of said switching diodes has been turned on.
Claim 7
Dependent Claim
44 words
A tuner as set forth in claim 1, wherein in one of said coils is electrically connected to said varactor diode to form a resonant circuit for tuning a low VHF channel when a respective one of said switching diodes has been turned on.
Claim 8
Dependent Claim
42 words
A tuner as set forth in claim wherein one of said coils is electrically connected to said varactor diode to form a resonant circuit for tuning a high VHF channel when a respective one of said switching diodes has been turned on.
References Cited (Backward Citations)
US3400345A
Cited
US3569850A
Cited
US3526859A
Cited
US3564423A
Cited
US3980957A
Cited
US4247953A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-11-30 | 1991-06-01 | 1991-12-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-11-30 | 1995-06-01 | 1995-12-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-11-30 | 1999-06-01 | 1999-12-01 | $7700.00 | Window Closed / Lapsed |