US4052674A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vhf tuner device
Assignee: Panasonic Holdings Corp
•
Filing: 1972-07-11
•
Granted: 1977-10-04
•
Expires: 1992-07-11
Abstract
Abstract An input device for a tuner utilizing as an amplifier element a bipolar transistor or tetrode metal-oxide-semiconductor field-effect transistor is provided in which an impedance means is connected in parallel with an impedance of an antenna; a capacitor means is inserted between the input terminal of the amplifier element and a group of tuning coils or inductance means for selecting the television channels in the high frequency band when a channel in the high frequency band is selected whereas an inductance means is inserted between the input terminal and a group of tuning coils for selecting the channels in the low frequency band when a channel in the low frequency band is selected; and an impedance means is inserted between the input terminal of the amplifier element and the earth. The tuning frequency band widths or selectivities in both the high and low frequency bands may be made substantially equal without causing the loss due to the impedance mismatching even when the input impedance of the amplifier element varies greatly in response to the change in frequency.
Inventors
- 👤 Kunito Miyamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 13:16
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/06; H04B1/16; H04B1/18; H03; H03J; H03J5/00; H03J5/24; H03J5/26; H03J5/30
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
165 words
In a tuner device having an input circuit comprised of capacitive reactance means in parallel with an antenna radiation impedance, an antenna circuit having an amplifier with an input electrode, and capacitive means between said electrode and a point of reference potential, and frequency selecting means connected between said input circuit and said amplifier circuit; the improvement wherein said frequency selecting means comprises first and second groups of inductors, means selectively connecting said input circuit to an end of each of said inductors, capacitor means having one terminal connected to the other ends of said inductors of the group of inductors corresponding to the higher tuning frequencies, inductor means having one terminal connected to the other ends of the inductors of the group of inductors corresponding to the lower tuning frequencies, means selectively connecting the other terminals of said capacitor means and inductor means to said electrode, and a capacitor connected between the other terminal of said capacitor means and a point of reference potential.
Claim 2
Dependent Claim
165 words
In a tuner device having an input circuit comprised of capacitive reactance means in parallel with an antenna radiation impedance, an antenna circuit having an amplifier with an input electrode, and capacitive means between said electrode and a point of reference potential, and frequency selecting means connected between said input circuit and said amplifier circuit; the improvement wherein said frequency selecting means comprises first and second groups of inductors, means selectively connecting said input circuit to an end of each of said inductors, capacitor means having one terminal connected to the other ends of said inductors of the group of inductors corresponding to the higher tuning frequencies, inductor means having one terminal connected to the other ends of the inductors of the group of inductors corresponding to the lower tuning frequencies, means selectively connecting the other terminals of said capacitor means and inductor means to said electrode, and a capacitor connected between the other terminal of said capacitor means and a point of reference potential.
Claim 3
Dependent Claim
13 words
The tuner device of claim 1 wherein said amplifier device comprises a MOSFET.
Claim 4
Dependent Claim
218 words
The tuner device of claim 1 comprising an insulating disk secured to a selecting shaft in a plane at right angles thereto, said means for selectively connecting the other terminals of said capacitor means comprising first and second arcuate conductors mounted on said disk at a first radius thereof and at different angular displacements, a first contact member positioned to selectively contact said arcuate conductors and coupled to said electrode, third and fourth arcuate conductors mounted on said disk and angularly aligned with said first and second arcuate conductors respectively at a second radius on said disk, said means for selectively connecting said input circuit comprising a plurality of contacts equi-angularly mounted on said disk at a third radius and a second contact member positioned to selectively contact said contacts, the inductors of said first group of inductors being connected between said third arcuate conductor and separate said contacts of a first group of said contacts, the inductors of said second group of inductors being connected between said fourth arcuate conductor and separate contacts of a second group of said contacts, said inductor means being connected between said first and third arcuate conductors, said capacitor means being connected between said second and fourth arcuate conductors, and said capacitor being connected between said second arcuate conductor and said shaft.
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) | 1980-10-03 | 1981-04-04 | 1981-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-03 | 1985-04-04 | 1985-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-03 | 1989-04-04 | 1989-10-04 | $7700.00 | Window Closed / Lapsed |