GB2305562A - TV VHF low and high band receiver with image trap capacitor - Google Patents
TV VHF low and high band receiver with image trap capacitor Download PDFInfo
- Publication number
- GB2305562A GB2305562A GB9618478A GB9618478A GB2305562A GB 2305562 A GB2305562 A GB 2305562A GB 9618478 A GB9618478 A GB 9618478A GB 9618478 A GB9618478 A GB 9618478A GB 2305562 A GB2305562 A GB 2305562A
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- United Kingdom
- Prior art keywords
- inductor
- capacitor
- vhf
- channel band
- circuit
- Prior art date
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Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/44—Receiver circuitry for the reception of television signals according to analogue transmission standards
- H04N5/50—Tuning indicators; Automatic tuning control
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
- H03J5/00—Discontinuous tuning; Selecting predetermined frequencies; Selecting frequency bands with or without continuous tuning in one or more of the bands, e.g. push-button tuning, turret tuner
- H03J5/24—Discontinuous tuning; Selecting predetermined frequencies; Selecting frequency bands with or without continuous tuning in one or more of the bands, e.g. push-button tuning, turret tuner with a number of separate pretuned tuning circuits or separate tuning elements selectively brought into circuit, e.g. for waveband selection or for television channel selection
- H03J5/246—Discontinuous tuning; Selecting predetermined frequencies; Selecting frequency bands with or without continuous tuning in one or more of the bands, e.g. push-button tuning, turret tuner with a number of separate pretuned tuning circuits or separate tuning elements selectively brought into circuit, e.g. for waveband selection or for television channel selection using electronic means
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- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Channel Selection Circuits, Automatic Tuning Circuits (AREA)
- Input Circuits Of Receivers And Coupling Of Receivers And Audio Equipment (AREA)
Description
2305562 TELEVISION TUNER INPUT TUNING CIRCUIT The present invention
relates to a television. tuner input tuning circuit, and more particularly to a television tuner input tuning circuit in which an image trap capacitor is made to participate in a time of reception in a VHF low channel band and a time of reception in a VHF high channel band, respectively, and the number of switch elements for changing over the receiving channel band is reduced so as to simplify circuit structure.
A television tuner for receiving a television broadcasting signal in a VHF band has been heretofore structured so as to change over a part of an input tuning circuit between the case when a low channel band consisting of 1 through 3 channels is received and the case when a high channel band consisting of 4 through 12 - 1 channels is received, so that a tuned state suitable for respective channel bands is obtainable in an input tuning circuit.
Fig. 3 is a circuit diagram showing an example of a structure of an already-known television tuner input tuning circuit.
As shown in Fig. 3, an input tuning circuit 31 is provided with an input terminal 53 and an output terminal 54, and the input terminal 53 is connected to an output of a VHF band selective filter 32 and the output terminal 54 is connected to an input of a highfrequency amplifier 33 through a coupling capacitor 34. The VHF band selective filter 32 is connected to an antenna 35 at the input thereof. Further, as to the circuit structure of the input tuning circuit 31, a first inductor 36, a second inductor 37, a first capacitor 38, a third inductor 39 and a second varactor diode (a second tuning capacitor) 47 are connected in series between the input terminal 53 and the output terminal 54, and a fourth inductor 40, a fifth inductor 41 and a resistance 50 are connected in series between the junction point of the first inductor 36 and the second inductor 37 and ground. A first switching diode 42 and an image trap capacitor 45 are connected in series between the junction point of the fourth inductor 40 and the fifth inductor 41 and the output terminal 54, and a second capacitor (a bypass capacitor) 51 is connected in parallel with a resistance 50. A second switching diode 43 is connected between the junction point of the first inductor 36 and the second inductor 37 and the junction point of the first switching diode 42 and the image trap capacitor 45, and a third switching diode 44 is connected between the junction ooint of the second inductor 37 and the first capacitor 38 and the junction point of the first switching diode 42 and the image trap capacitor 45. A first varactor diode (a first tuning capacitor) 46 is connected between the junction point of the third inductor 39 and the second varactor diode 47 and ground, and a first buffer resistance 48 is connected between the junction point of the third inductor 39 and the second varactor diode 47 and a tuning voltage supply terminal 55. A second buffer resistance 49 is connected between the junction point of the first switching diode 42 and the image tralp capacitor 45 and a high channel band selective voltage supply terminal 56, and a third buffer resistance 52 is connected between the junction point of the fifth inductor 41 and the resistance 50 and a low channel band selective voltage supply terminal 57.
The input tuning circuit 31 having a structure described above is operated as follows.
First, at a time of recer)tion in a VHF low channel, changeover voltage VL of positive polarity is supplied to the low channel band selective voltage supply terminal 57. With this, backward bias voltage is applied to respective first, second and third switching diodes 42, 43 and 44, and each of the first through the third switching diodes 42 to 44 is cut off. Tuning voltage VTU is supplied to the tuning voltage supply terminal 55 simultaneously with the above, thereby to set capacity values of the first and the second varactor diodes 46 and 47.
in this state, the input tuning circuit 31 is structured so that the first inductor 36, the second;nductor 37,..he first capacitor 38, the third inductor 39 and the second varactor diode 47 are connected in series between the -nzut terminal 53 and the outDut terminal 54, the fourth inductor 40, the fifth inductor 41 and the second capacitor 51 are connected in series between the Junction point of the first inductor 36 and the second inductor 37 and ground, the second varactor 4 - diode 47 is connected between the junction point of the third inductor 39 and the second varactor diode 47 and ground, and the image trap capacitor 45 is detached from the input tuning circuit 31 substantially. Further, a T-shaped circuit composed of the first inductor 36, the second inductor 37, the third inductor 39, the fourth inductor 40 and the 'Lifth inductor 41 constitutes a matching circuit for a signal in the VHF low channel band.
When a signal is received with the antenna 35,a VHF signal is selected out of the received signals by means of the VH17 band selective filter 32, and is supplied to the input tuning circuit 31. The input tuning circuit 31 selects a signal of a predetermined channel such as a channel 1 in the VHF low channel band which is set by capacity values of the first and the second varactor diodes 46 and 47, and supplies the signal to the highfrequency amplifier 33 connected next through the coupling capacitor 34.
Next, at a time of receiving a VHF high channel, changeover voltage VH of positive polarity is supplied to the high channel band selective voltage supply terminal 56. With this, forward bias voltage is applied to respective fIrst, second and third switching diodes 42, 43 and 44, and each of the first through the third switching diodes 42 to 44 ls brought to an on-state. Simultaneously, tuning voltage VTU is suppl-Jed to the tuning voltage supply terminal 55, thereby to set the capacity values of the first and the second varactor diodes 46 and 47.
In this state, the input tuning circuit 31 is structured so that the first inductor 36, the first capacitor 38, the third inductor 39 and the second varactor diode 47 are connected in series between the inout terminal 53 and the output terminal 54, the fifth inductor 41 and the second capacitor 51 are connected in series between the junction point of the first inductor 36 and the first capacitor 38 and ground, the second varactor diode 47 is connected between the junctlon point of the third inductor 39 and the second varactor diode 47 and ground, and the image trap capacitor 45 is connected in parallel with the series circuit of the first capacitor 38, the third induct-or 39 and the second varactor diode 47, and the second inductor 37 and the fourth inductor 40 are detached from the input tuning circuit 31 substantially. Further, a T-shaped circuit composed of the first induct-or 36, the third inductor 39 and the fifth inductor 41 constitutes a matching circuit for a signal in the VHF high channel band, and a parallel circuit composed of the first capacitor 38, the third inductor 39, the second varactor diode 47 and the image trap capacitor 45 constitutes a variable image trap for a signal in the VHF high channel band.
Here, when a signal is received with the antenna 35, a VHF signal is selected out of the received signals by means of the VHF band selective filter 32, and is supplied to the input tuning circuit 31. The input tuning circuit 31 selects a signal of a predetermined. channel such as a channel 10 in the VHF high channel band which is set with the capacity values of the first and the second varactor diodes 46 and 47, and supplies the signal to the high-frequency amplifier 33 connected next through the coupling capacitor 34.
The already-known television tuner input tuning ci.,cuit 31 described above has such a problem that the tuning 'Ll-unction for a signal in the VHF low channel band is deteriorated because the variable image trap including the image tralp capacitor 45 contributes only to a signal in the VHF high channel band, but does not contribute to a signal in the VHF low channel band at all. Moreover, since the image trap capacitor 45 is placed directly in the tuning circuit, there is such a problem that setting of an image trap frequency depends on the tuning frequency, and not only the dispersion is increased, but also marked dispersion is generated in an;.mage interference ratio.
Further, since the already-known television tuner input tuning circuit 31 described above uses the first through the third switching diodes 42, 43 and 44 for changing over the VHF low channel band to and from the VHF high channel band, there is a problem that the circuit structure becomes comparatively complicated.
Furthermore, in the already-known television tuner input tuning circuit 31 described above, signals of a higher frequency than a signal in the VHF high channel band are attenuated by the first inductor 36, but, since the first inductor 36 does not contribute to attenuation of a high- frequency signal outside the VHF low channel band at a time of receiving a signal in the VHF low channel band, there is a problem that, when an; nterference signal exists in the high-frequency band outside the VHF low channel, a signal in the VHF low channel band is subject to the influence of the signal and the influence by beat and so on aDr)ear on a display screen.
8 The present invention is to solve these problems, and it is a first object thereof to provide a television tuner input tuning circuit in which an image trap is interposed in each of a VHF low channel band and a VHF high channel band and the circuit structure is simplified.
Further, it is a second object of the present invention to provide a television tuner input tuning circuit in which the signals of higher frequency than the signals in the VHF low channel band at a time of receiving a signal in the VHF low channel band, thereby to eliminate generation of an interference signal.
In order "to achieve the above-mentioned first object, the present invention is provided with a first means which is composed of at least a plurality of inductors, one or more voltage-variable capacitor, one image trap capacitor and two switching elements and is in a state that the two switch elements described above are switched so as to connect by changing over a part among the plurality of Inductors corresponding to recer)tion in the VHF low channel band and receDtion of the VHF high channel band and the image trap capacitor 9 - is always connected irrespective of the changeover connection.
Further, in order to achieve the above-mentioned first and second objects, the present invention is,Drovided with a second means commosed of a first inductor, a second inductor, a third induct-or, a fourth inductor connected in series, a tuning capacitor connected between the output end of the fourth inductor and ground, a first switch element and a sixth inductor connected in series between the junction point of the. first inductor and the second inductor and ground, a fifth inductor connected between the junction point of the second inductor and the third inductor and ground, a second switch element connected between the junction point of the third inductor and the fourth inductor and the junction point of the first switch element and the fifth inductor, and an image trap capacitor connected between the iniDut end of the first inductor and the outiDut end of the fourth inductor, in which the first switch element and the second swit-ch element are turned OFF at a time of 1-ecepti_n in the VHF low channel band and turned ON at a time of recer)tion in the VHF high channel band.
- 10 According to the first means, since it is in a state that an image tralp capacitor is connected substantially within the circuit in both cases of reception in the VHF low channel band and reception in the VHF high channel band, the tuning function will never be deteriorated not only at a time of reception in the VHF high channel band, but also at a time of reception in the VHF low channel band.
Further, according to the first means, since a changeover of reception of the VHF low channel band to and from reception of the VHF high channel band is achieved by switching of two switch elements, it becomes not only possible to reduce the number of switch elements reauired for the changeover by one only, but also to simplify the circuit structure as compared with an already-known input tuning circuit of this sort.
According to the second means, since it is in a state that the image trap capacitor is connected within the circuit substantially in both cases of reception in the VHF low c.;.,.annel band and reception in the VHF high channel band similarly to the above-mentioned first means, the tuning function will never be deteriorated not only at a time of reception in the VHF high channel - 11 band, but also at a time of reception in the VHF low channel band.
Further, according to the above-mentioned second means, since the changeover of the reception in the VHF low channel band to and from the reception in the VHF high channel band is achieved by means of switching of two switch elements similarIv to the above-mentioned first means, it is not only possible to reduce the number of switch elements required for the changeover by one only, but also it becomes possible to simplify the circuit structure.
Furthermore, according tc the above-mentioned second means, since the second inductor is connected in series with the first inductor and these two inductors cooperate with each other so as to attenuate a signal of high frequency outside the VHF low channel band at a time of reception in the VHF low channel band, it is possible to remove with attenuation such interference components existing in the high-frequency band, thus eliminating generatIon of beat interference on the display screen.
12 - 7114GB Embodiments of the present invention will be described in detail hereinafter with reference to the drawings, in which:
Fig. 1 shows a circuit diagram showing a first embodiment of a television tuner input tuning circuit according to the present invention; Fig. 2 shows a circuit diagram showing a second embodiment of a television tuner input tuning circuit according to the present invention; and Fig. 3 shows a circuit diagram showing an example of a structure of a previously proposed television tuner input tuning circuit.
Fig. 1 is a circuit diagram showing a first embodiment of a television tuner input tuning circuit according to the present invention.
As shown in Fig. 1, an input tuning circuit 1 is provided with an input terminal 23 and an output terminal 24, and the input terminal 23 is connected to an output of a VHF band selective filter 2 and the output terminal 24 is connected to an input of a high-frequency amplifier 3 through a coupling capacitor 4. The VHF band selective filter 2 is connected to an antenna 5 at the input thereof. Further, the circuit structure of the input tuning circuit 1 is such that a first inductor 6, a second inductor 7, a third inductor 8, a first capacitor 9 and a fourth inductor 10 are connected in series between the input terminal 23 and the output terminal 24, and a first switching diode 13, a sixth inductor 16 and a resistance 20 are connected in series between the junction point of the first inductor 6 and the second inductor 7 and ground. A fifth inductor 12 and a second capacitor (a bypass capacitor) 18 are connected in series between the junction point of the second inductor 7 and the third inductor 8 and ground. A second switching diode (a second switch element) 14 ls connected between the junctJon point of the third inductor 8 and the first car)acitor 9 and the junction point of the first switching diode (the first switch element) 13 and the sixth inductor 16. A varactor diode (a tuning capacitor) 15 is connected between the output terminal 24 and ground, and an image trap capacitor 11 is connected between the input terminal 23 and the output terminal 24. A first buffer resistance 17 is connected between the junction point of the fifth inductor 12 and the second capacitor 18 and a high channel band selective voltage supply terminal 26, and a second buffer resistance 19 is connected between the output terminal 24 and a tuning voltage supply terminal 25. A third capacitor (a bypass capacitor) 21 is connected in parallel with the resistance 20, and a third buffer resistance 22 is connected between the junction point of the sixth inductor 16 and the resistance 20 and a low channel band selective voltage supply terminal 27.
The input tuning circuit 1 of the first embodiment having a structure described above is operated as follows.
First, at a time of receiving the VHF low channel, changeover voltage VL Of positive polarity is supplied to the low channel band selective voltage supply terminal 27. With this, backward bias voltage is aDr)lied to the first and the second switching diodes 13 and 14, and the first and the second switching diodes 13 and 14 are cut off. Simultaneously, tuning voltage VTU is supplied to the tuning voltage supply terminal 25, thereby to set the capacity value of the varactor diode 15.
In such a state, the input tuning circuit 1 is structured so that the first inductor 6, the second inductor 7, the third inductor 8, the first capacitor 9 and the fourth Inductor 10 are connected in series between the =Dut terminal 23 and the output terminal 24, the fifth inductor 12 and the second capacitor 18 are connected in series between the junction point of the second Inductor 7 and the th-'--d inductor 8 and ground, the varactor diode 15 is connected between the out-nut terminal 24 and ground, and the image trap caz)ac-4tor 1-1 _Js connected between the inout terminal 23 and the Output terminal 24, in which the sixth inductor 16 and the th-4--d canacitor 21 are detached from the input tuning ci.-cuit 1 substantially. In this case, a - is - T-shaped circuit composed of the first inductor 6, the second inductor 7, the third inductor 8, the fourth inductor 10 and the fifth inductor 12 constitutes a matching circuit for a signal in the VHF low channel band, and a r)aral-lel circuit comoosed of the first inductor 6, the second inductor 7, the third inductor 8, the first car)acitor 9, the fourth inductor 10 and the image trap capacitor 11 constitutes a variable image trap for a signal in the VHF low channel band.
Here, when a signal is received with an antenna 5, a VHF signal is selected out of received signals by means of the VHF band selective filter 2 and supplied to the input tuning circuit 1. The input tuning circuit 1 selects a signal of a predetermined channel such as the channel 1 in the VHF low channel band which is set by the capacity value of the varactor diode 15 and supplies the signal ---c next. through Then, the high-frequency amplifier 3 connected the coupling capacitor 4. at a ti-ne of reception in the VHF high channel, changeover voltage VH of positive polarity is supplied to a high channel band selective voltage supply terminal 26. With this, forward bias voltage is applied to the fIrst and the second switching diodes 13 and 14, and the first and the second switching diodes 13 and 14 - 16 are brought into an on-state. Simultaneously, tuning voltage VTU is SUDDlied to the tuning voltage supply terminal 25, thus setting the capacity value of the varactor diode 15. in such a state, the input- tuning circuit I is structured so that the first inductor 6, the first capacitor 9 and the fourth inductor 10 are connected in series between the input terminal 23 and the output terminal 24, t-he sixth inductor 16 and the third capacitor 21 are connected in series between the junction point of the first inductor 6 and the first capacitor 9 and ground, the varactor diode 15 is connected between the output terminal 24 and ground, and the image 1CraD capacitor 11 is connected in r)arallel with the series circuit of the first induct-or 6, the first caDacitor 9 and the fourth inductor 10, in which the second inductor 7, the third inductor 8 and the fifth -4nduc-lor 12), the second canacitor 18 are detached from an input:unina circuit I substantialIv. in this case, a T-shaiDed circuit comnosed of the first inductor 6, the fourth inductor 10 and the sixth inductor 16 constitutes a matching circuit for, a signal in the VHF high channel band, and a parallel circuit composed of the first inductor 6, the first car)acitor 9, Che fourth inductor 10 and the image trap capacitor 11 constitutes a variable image trap for a signal in the VHF high channel band.
Here, when a signal is received with an antenna 5, a VHF signal is selected out of received signals by means of the VHF band selective filter 2 and supplied to the input tuning circuit 1. The input tuning circuit 1 selects a signal of a predetermined channel such as a channel 8 in the VHF high channel band which is set depending on the capacity value of the varactor diode 15, and supplies the signal to the high-frequency amplifier 3 connected next through the coupling capacitor 4.
As described, according to the input tuning cIrcuit 1 related to the first embodiment, a variable image trap is formed not only when changeover has been made to the reception of the signal in the VHF high channel band, but also when changeover has been made to the reception of the signal in the VHF low channel band. Therefore, the tuning function ls never deteriorated not only at a time of reception in the VHF high channel band, but also at a time of reception in the VHF low channel band.
- 18 Further, according to the input tuning circuit 1 related to the first embodiment, the receotion in the VHF low channel band is changed over to and from the reception in the VHF high channel band only by using the first and the second switching diodes 1-3 and I.A. Therefore, as an already-known input tuning circuit of this sort, it is possible to reduce the number of switching diodes required for changing over the channel band by one only, and to simplify the whole circuit structure by that portion.
Furthermore, according to the input tuning circuit 1 related to the first embodiment, the second inductor 7 is connected n series with the first inductor 6 only at a time of reception in the VHF low channel band, and these inductors 6 and 7 cooperate with each other to attenuate the high frequency outside the VHF low channel band. Thus, even if an interference signal exists in such a high-frequency band, the;nterference signal is sufficiently atteniated and removed by means of -Ihe first inductor 6 and the second inductor 7. Therefore, such an ill effect that beat; nterference is produced on the display screen Js nrevented.
Next, Fig. 2 is a circuit diagram showing a second embodiment of a television tuner input tuning circuit according to the present invention.
The difference in the structure between the second embodiment and the first embodiment described above is only the fact that, in the second embodiment, a second varactor diode (a second tuning capacitor) 28 is used and connected between the output end of the fourth inductor 10 and the output terminal 24, whereas, in the first embodiment, the second varactor diode 28 is omitted and the output end of the fourth inductor 10 is connected directly to the output terminal 24 (besides, in relation to this difference, the connecting part of the image trap capacIll-or 11 is also different formally, but there is no difference in the point that the image trap capacitor 11 is connected between the input terminal 23 and the output terminal 24. Therefore, the difference In this Doint is not included in the difference in the structure), and there is no difference in the structure between the second embodiment and the first embodiment. T.hus, further description is omitted with respect to the structure of the second embodiment.
Fu.--.her, since the operation and the obtainable effect of the second embodiment are essentially the same - 20 as the operation and the obtainable effect of the already described first embodiment, the description of t.he oDeration and the obtainable effect of the second embodiment is omitted.
However, th,e second embodiment is somewhat different frcr7 the first embodiment in such points that, at a time of recer)tion in the VHF low channel, a -oarallel circuit comr)osed of the first inductor 6, the second inductor 7, the third inductor 8, the first canacitor 9, the fourth inductor 10, the second varactor diode 28 and the image trap capacitor 11 constitutes a variable image trap for a signal in the VHF low channel band, and, at a time of reception in the VHF high channel, a parallel circuit comDosed of the first inductor 6, the first capacitor 9, the fourth inductor 10, the second varactor diode 28 and the image trap capacitor 11 constitutes a variable image trap for a signal in the VHF high channel band.
As described in detail above, according to the present invention, since the inDut tuning circuit is in a state that the image trap capacitor 11 is connected essentially within the circuit In both cases of reception in t-he VHF low channel band and reception in 21 the VHF high channel band, an effect that the tuning function is not deteriorated not only at a time of recention in the VHF high channel band, but also at a time of reception in the VHF low channel band is Droduced.
Further, according to the present invention, the changeover of the receptIon in the VHF low channel band to and from the reception in the VHF high channel band.1s achieved by means of switching of two switch elements 13 and 14. Thus, such an effect that it is not only possible to reduce the number of switch elements required for the changeover by one only, but also to simplify the circuit structure as compared with an already-known input tuning circuit of this sort is mroduced.
Furthermore, according to the present invention, since the second inductor 7 is connected in series with the first inductor 6 and these two inductors 6 and 7 cooiDerate with eact, other so as to attenuate a hightrequency signal outside the VHF low channel band, such an effect that it is possible to attenuate and remove interference components existing in such a highfrequencv band, and beat interference is never produced on the display screen is also produced.
7114GB
Claims (5)
1. A television tuner input tuning circuit, comprising; a plurality of inductors; one or more voltagevariable capacitors; an image trap capacitor; and two switch elements; wherein, corresponding to reception in a VHF low channel band and reception in a VHF high channel band, said two switch elements are switched so as to change over and connect a part of said plurality of inductors, and the circuit is in a state that said image trap capacitor is always connected irrespective of said changeover connection.
2. comprising: a first inductor, a second inductor, a third inductor and a fourth inductor connected in series; a tuning capacitor connected between the output end of said fourth inductor and ground; a first switch element and a sixth inductor connected in series between the junction point of said first inductor and said second inductor and ground; a fifth inductor connected between the junction point of said second inductor and said third inductor and ground; a second switch element connected between the junction point of said third inductor and said fourth inductor and the junction point of said first switch element and said fifth inductor; and an image trap capacitor connected between the input end of said first inductor and the output end of said fourth inductor; wherein said first switch element and said second switch element are turned OFF at a time of reception in a VHF low channel band and turned ON at a time of reception in a VHF high channel band.
3. A television tuner input tuning circuit as A television tuner input tuning circuit, 7114GB claimed in Claim 2, wherein a second tuning capacitor is connected between the output end of said fourth inductor and an input of a high-frequency amplifier connected next thereto, and said image trap capacitor is connected between the input end of said first inductor and the input of said high-frequency amplifier connected next thereto.
4. A television tuner input tuning circuit as claimed in Claim 2 or 3, wherein said first switch element and said second switch element are high-frequency switching diodes.
5. A television tuner input tuning circuit substantially as hereinbefore described with reference to, and as illustrated by, Fig. 1 or Fig. 2 of the accompanying drawings.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24632295A JPH0993091A (en) | 1995-09-25 | 1995-09-25 | Input tuning circuit of television tuner |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB9618478D0 GB9618478D0 (en) | 1996-10-16 |
| GB2305562A true GB2305562A (en) | 1997-04-09 |
| GB2305562B GB2305562B (en) | 1999-12-08 |
Family
ID=17146840
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9618478A Expired - Fee Related GB2305562B (en) | 1995-09-25 | 1996-09-04 | Television tuner input tuning circuit |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JPH0993091A (en) |
| DE (1) | DE19639238C2 (en) |
| GB (1) | GB2305562B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000011783A1 (en) * | 1998-08-25 | 2000-03-02 | Koninklijke Philips Electronics N.V. | Tuned band-pass circuit |
| JP3828745B2 (en) | 2000-12-14 | 2006-10-04 | アルプス電気株式会社 | Television tuner |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5054117A (en) * | 1989-08-01 | 1991-10-01 | Zenith Electronics Corporation | Tunable UHF filter for switchable VHF/UHF receiver |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2909319C2 (en) * | 1979-03-09 | 1982-10-14 | Blaupunkt-Werke Gmbh, 3200 Hildesheim | tuner |
| US5428828A (en) * | 1992-08-28 | 1995-06-27 | Thomson Consumer Electronics, Inc. | Television receiver tuning circuit |
| JP3053150B2 (en) * | 1993-02-26 | 2000-06-19 | アルプス電気株式会社 | TV tuner input tuning circuit |
-
1995
- 1995-09-25 JP JP24632295A patent/JPH0993091A/en not_active Withdrawn
-
1996
- 1996-09-04 GB GB9618478A patent/GB2305562B/en not_active Expired - Fee Related
- 1996-09-24 DE DE1996139238 patent/DE19639238C2/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5054117A (en) * | 1989-08-01 | 1991-10-01 | Zenith Electronics Corporation | Tunable UHF filter for switchable VHF/UHF receiver |
Also Published As
| Publication number | Publication date |
|---|---|
| DE19639238C2 (en) | 2002-07-11 |
| DE19639238A1 (en) | 1997-03-27 |
| GB2305562B (en) | 1999-12-08 |
| JPH0993091A (en) | 1997-04-04 |
| GB9618478D0 (en) | 1996-10-16 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20060904 |