EP0145076A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Television receiver input circuit
Assignee: Philips North America LLC
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Filing: 1984-11-28
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Granted: —
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Expires: 2004-11-28
Abstract
Abstract O A television receiver of the type capable of displaying standard VHF and UHF television signals is provided with a single coaxial antenna input terminal. A passive input circuit within the receiver include s two filter sections for separating the VHF and UHF components of a combined VHF-UHF signal applied to the input terminal for application to separate VHF and UHF tuning sections of the receiver. The first filter section, which is located within the UHF tuning section, includes a UHF tuning line for coupling the UHF component to the UHF tuning section. The second filter section, which is located in the VHF filter section, and incorporates elements of the first filter section, enhances the response of the receiver over transition frequencies between the VHF and UHF bands.
Inventors
- 👤 David Richard Hiday
- 👤 Charles Grisbrook Larsen
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 13:55
CPC Classifications
H; H03; H03H; H03H7/00; H03H7/46; H03H7/466; H03J; H03J5/00; H03J5/24; H03J5/242; H03J5/244
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
278 words
In a television receiver of the type having a VHF tuner circuit, a UHF tuner circuit and an input terminal, an input circuit for separating the VHF and UHF components of a combined VHF-UHF signal applied to the input terminal, and for applying the separated VHF and UHF components to the input the respective VHF and UHF tuner circuits, comprising: a UHF tuning line connected with the input of the UHF tuner circuit; a first inductor having one end electrically connected to the input terminal, said first inductor being disposed adjacent said UHF tuning line whereby said UHF tuning line is in electromagnetic communication with said first inductor; a first capacitor electrically connected between the remaining terminal of said first inductor and forming together with said first inductor coupling means for electromagnetically coupling the UHF components of the applied signal to said UHF tuning line; a second inductor having a first end electrically connected to said remaining end of said first inductor and having its remaining end electrically connected tothe input of the VHF tuner circuit; and a third inductor and a second capacitor serially connected between the remaining end of said second inductor and ground, whereby said first inductor, said first capacitor and said second inductor together form a low-pass filter section, and said second inductor, said third inductor and said second capacitor together form an additional low-pass filter section, whereby VHF signals applied to said input terminal pass to the input of the VHF tuner circuit, UHF signals applied to said input terminal pass to the input of the UIIF tuner circuit, the UHF signals being substantially attenuated at the input of the VHF tuner circuit.
Claim 2
Dependent Claim
278 words
In a television receiver of the type having a VHF tuner circuit, a UHF tuner circuit and an input terminal, an input circuit for separating the VHF and UHF components of a combined VHF-UHF signal applied to the input terminal, and for applying the separated VHF and UHF components to the input the respective VHF and UHF tuner circuits, comprising: a UHF tuning line connected with the input of the UHF tuner circuit; a first inductor having one end electrically connected to the input terminal, said first inductor being disposed adjacent said UHF tuning line whereby said UHF tuning line is in electromagnetic communication with said first inductor; a first capacitor electrically connected between the remaining terminal of said first inductor and forming together with said first inductor coupling means for electromagnetically coupling the UHF components of the applied signal to said UHF tuning line; a second inductor having a first end electrically connected to said remaining end of said first inductor and having its remaining end electrically connected tothe input of the VHF tuner circuit; and a third inductor and a second capacitor serially connected between the remaining end of said second inductor and ground, whereby said first inductor, said first capacitor and said second inductor together form a low-pass filter section, and said second inductor, said third inductor and said second capacitor together form an additional low-pass filter section, whereby VHF signals applied to said input terminal pass to the input of the VHF tuner circuit, UHF signals applied to said input terminal pass to the input of the UIIF tuner circuit, the UHF signals being substantially attenuated at the input of the VHF tuner circuit.
Claim 3
Dependent Claim
32 words
An input circuit as defined in Claim 1, wherein said first inductor, said first capacitor and said second inductor form a low-pass constant-k filter section for substantially attenuating signals above 500 MHz.
Claim 4
Dependent Claim
33 words
An input circuitas defined in Claim 2, wherein said second inductor, said third inductor and said second capacitor together form a low-pass m-derived terminating half section for substantially attenuating frequencies above 500 MHz.
Claim 5
Dependent Claim
50 words
An input circuit as defined in Claim 3, wherein said UHF tuning line comprises a conductor and at least one tuning varactor, said conductor connected at least at one end to one terminal of said at least one tuning varactor, said conductor being in electromagnetic communication with said coupling loop.
Claim 6
Dependent Claim
24 words
An input circuit as defined in Claim 3, wherein the input impedance of said signal splitting circuit at the input terminal is seventy-five ohmss.
Claim 7
Dependent Claim
59 words
An input circuit as defined in Claim 5, wherein said first inductors has an inductance of approximately 29.8 microhertz, said second induction has an inductance of 47.8 microhertz, said third inductor has an inductance of approximately 32 microhertz, said first capacitor has a capacitance of approximately 10.6 picofarads and said second capacitor has a capacitance of approximately 32 picofarads.
Claim 8
Dependent Claim
134 words
An input circuit for use in a television receiver of the type having a VHF tuner section, a UHF tuner section and a single input terminal, for separating the VHF and UHF components of a combined VHF-UHF signal applied to the input terminal and for applying the VHF and UHF components to the input of respective VHF and UHF tuner circuits, comprising: a constant-k low-pass filter section having an input electrically connected to the input terminal and including at least one inductor element; means for electromagnetically coupling said at least one inductor element to the input of the UHF tuner circuit; and a low pass m-derived filter section having its input electrically connected to the output of said constant-k filter section and having its output connected to the input of the VHF tuner circuit.
Claim 9
Dependent Claim
134 words
An input circuit for use in a television receiver of the type having a VHF tuner section, a UHF tuner section and a single input terminal, for separating the VHF and UHF components of a combined VHF-UHF signal applied to the input terminal and for applying the VHF and UHF components to the input of respective VHF and UHF tuner circuits, comprising: a constant-k low-pass filter section having an input electrically connected to the input terminal and including at least one inductor element; means for electromagnetically coupling said at least one inductor element to the input of the UHF tuner circuit; and a low pass m-derived filter section having its input electrically connected to the output of said constant-k filter section and having its output connected to the input of the VHF tuner circuit.
Claim 10
Dependent Claim
33 words
An input circuit as defined in Claim 7, wherein said means for electromagnetically coupling said at least one inductor element to the input of the UHF tuner circuit comprises a UHF tuning line.
Claim 11
Dependent Claim
66 words
An input circuit as defined in Claim 8 wherein said constant-k filter section comprises a first inductor having one end connected to the coaxial input terminal, a second inductor having one end connected to the remaining end of said first inductor and a first capacitor connected between the juncture of said remaining end of said first inductor and said end of said second inductor and ground.
Claim 12
Dependent Claim
41 words
An input circuit as defined in Claim 10, wherein said low pass m-derived filter section comprises in addition to said second inductor, a third inductor and a second capacitor serially connected between the remaining terminal of said second inductor and ground.
References Cited (Backward Citations)
No citation records indexed.
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