JPH0625067Y2 - Television tuner - Google Patents
Television tunerInfo
- Publication number
- JPH0625067Y2 JPH0625067Y2 JP1989038909U JP3890989U JPH0625067Y2 JP H0625067 Y2 JPH0625067 Y2 JP H0625067Y2 JP 1989038909 U JP1989038909 U JP 1989038909U JP 3890989 U JP3890989 U JP 3890989U JP H0625067 Y2 JPH0625067 Y2 JP H0625067Y2
- Authority
- JP
- Japan
- Prior art keywords
- capacitance
- circuit
- uhf
- capacitor
- vhf
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Landscapes
- Circuits Of Receivers In General (AREA)
- Input Circuits Of Receivers And Coupling Of Receivers And Audio Equipment (AREA)
Description
【考案の詳細な説明】 産業上の利用分野 この考案はテレビ及びＶＴＲ装置に用いるテレビジョン
チューナの中間周波用π型帯域通過回路に関する。DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention relates to a π-type bandpass circuit for an intermediate frequency of a television tuner used in a television and a VTR device.
従来の技術 テレビやＶＴＲ装置用チューナのＵＨＦ同調部は、テレ
ビ局から送られてくる信号を受信する入力回路、この入
力信号を増幅する高周波増幅回路、搬送周波数を所定の
中間周波数に変換する混合回路、中間周波数を作り出す
に必要な周波数を発振させる局部発振回路、混合回路で
変換された中間周波数を通過させるＵＨＦ中間周波（以
下ＵＨＦ・ＩＦと呼ぶ）回路とで構成されており、従来
の回路図を第３図に示し、説明する。ＵＨＦ混合用素子
Ｑ1で中間周波数に変換された信号は、コンデンサＣ2，
Ｃ3やコイルＬ1により構成のπ型のＵＨＦ・ＩＦ用帯域
通過回路を通り、ＵＨＦ用切換ダイオードＱ２と結合用
コンデンサＣ4を経由してＶＨＦ部混合用素子Ｑ3に入力
される。混合用素子Ｑ3は、ＵＨＦ動作時にはＵＨＦ・
ＩＦ信号の増幅素子として使用されている。また、第３
図における抵抗Ｒ1、Ｒ2、Ｒ3は混合素子Ｑ1を動作させ
るための直流バイアス抵抗、コンデンサＣ1は混合素子
Ｑ1の高周波接地用コンデンサ、抵抗Ｒ4は素子Ｑ1、Ｑ2
の動作用直流バイアス抵抗であり、Ｒ5はダイオード素
子Ｑ2の動作用の直流バイアス抵抗、Ｃ5はＶＨＦ部局部
発振電圧注入用コンデンサ、Ｃ6はＶＨＦ部信号結合用
コンデンサを示す。2. Description of the Related Art A UHF tuning unit of a tuner for a television or a VTR device includes an input circuit that receives a signal sent from a television station, a high frequency amplifier circuit that amplifies the input signal, and a mixing circuit that converts a carrier frequency to a predetermined intermediate frequency. , A local oscillation circuit that oscillates a frequency required to generate an intermediate frequency, and a UHF intermediate frequency (hereinafter referred to as UHF / IF) circuit that passes the intermediate frequency converted by the mixing circuit. Is shown in FIG. 3 and will be described. The signal converted to the intermediate frequency by the UHF mixing element Q 1 has a capacitor C 2 ,
It passes through a π-type UHF / IF band pass circuit constituted by C 3 and a coil L 1, and is input to the VHF section mixing element Q 3 via the UHF switching diode Q 2 and the coupling capacitor C 4 . The mixing element Q 3 is UHF
It is used as an amplifying element for IF signals. Also, the third
In the figure, resistors R 1 , R 2 and R 3 are DC bias resistors for operating the mixed element Q 1 , a capacitor C 1 is a capacitor for high frequency grounding of the mixed element Q 1 , and a resistor R 4 is elements Q 1 and Q 2.
Is a DC bias resistor for operation, R 5 is a DC bias resistor for operation of the diode element Q 2 , C 5 is a VHF local oscillation voltage injection capacitor, and C 6 is a VHF signal coupling capacitor.
考案が解決しようとする課題 ところで、近年テレビやＶＴＲにおいては、小型化の要
求が急激に増してきており、当然それに使用されている
部分の小型化が必須条件となってきた。チューナのその
中の１つであり、その小型化を実現させる為に、使用し
ている部品の小型化も必要であるが、回路の簡素化によ
る部品点数の削減が必要とされ、これが実施されない限
り限界がある。DISCLOSURE OF THE INVENTION Problems to be solved by the invention By the way, in recent years, in TVs and VTRs, the demand for miniaturization has rapidly increased, and naturally the miniaturization of the parts used therein has become an essential condition. This is one of the tuners, and it is necessary to reduce the size of the parts used in order to realize its miniaturization, but it is necessary to reduce the number of parts by simplifying the circuit, and this is not implemented. There are limits.
従って、本考案は上記に鑑み提案されたものであり、回
路簡素化による部品点数の削減を実現させる為の新規且
つ改良された構造の提供を目的とするものである。Therefore, the present invention has been proposed in view of the above, and an object thereof is to provide a new and improved structure for realizing the reduction of the number of parts by simplifying the circuit.
課題を解決するための手段 本考案によれば、中間周波（ＵＨＦ・ＩＦ用）π型帯域
通過回路のうち、一方の脚部容量を混合用素子Ｑ1のコ
レクタ容量及び接地用バイアス容量を含む静電容量を主
とし、又他方の脚部容量をＵＨＦ結合容量とＶＨＦ混合
用素子の入力容量を含む静電容量を主として構成させる
事により、コンデンサＣ2，Ｃ3を削減させる事ができ
る。この場合の条件として素子Ｑ1のCobは0.5〜２PF、
コイルＬ1は１〜2.7μＨ、コンデンサＣ4は１〜100PF、
コンデンサＣ5は0.5〜20PF及びコンデンサＣ6は0.5〜20
PF及びコンデンサＣ1は30〜4700PFの範囲内で用い、こ
れらを適宜に組み合せることで好ましい定数設定ができ
る。According to the present invention, one leg capacitance of the intermediate frequency (for UHF / IF) π band pass circuit includes the collector capacitance of the mixing element Q 1 and the bias capacitance for grounding. It is possible to reduce the capacitors C 2 and C 3 by mainly configuring the electrostatic capacitance and mainly configuring the other leg capacitance by the electrostatic capacitance including the UHF coupling capacitance and the input capacitance of the VHF mixing element. As a condition in this case, Cob of the element Q 1 is 0.5 to 2 PF,
The coil L 1 is 1 to 2.7 μH, the capacitor C 4 is 1 to 100 PF,
The capacitor C 5 is 0.5 to 20PF and the capacitor C 6 is 0.5 to 20PF.
The PF and the capacitor C 1 are used within the range of 30 to 4700 PF, and a proper constant can be set by appropriately combining these.
作用 上記の構成により部品点数が２点削減でき、それによる
プリント基盤への部品配置面積を小さくする事により、
チューナとしての形状も小型化が可能となる。By the above configuration, the number of parts can be reduced by 2 points, and by doing so, the part layout area on the printed circuit board can be reduced,
The shape of the tuner can be reduced in size.
実施例 以下本考案に係る実施例を第１図及び第２図を参照して
説明する。Embodiment An embodiment according to the present invention will be described below with reference to FIGS. 1 and 2.
第１図は本考案の一実施例を示した回路図である。従来
の回路を示す第３図と比較してπ型同調回路部分のコン
デンサＣ2，Ｃ3が削除されて回路が簡素化されている。
尚第１図の構成において、第３図に示す部品と対応する
部分には同一の符号を用いて示したので詳細な説明を省
く。第２図は、本考案におけるπ型帯域通過回路を等価
的に示した図であり、コンデンサＣ7は素子Ｑ1のコレク
タ容量、コンデンサＣ8は素子Ｑ3の入力容量、コンデン
サＣ9はＶＨＦ部局部発振回路における静電容量、コン
デンサＣ10はＶＨＦ部混合用同調回路における静電容量
を示す。FIG. 1 is a circuit diagram showing an embodiment of the present invention. Compared to FIG. 3 showing a conventional circuit, the circuits are simplified by removing the capacitors C 2 and C 3 in the π type tuning circuit portion.
In the structure of FIG. 1, the parts corresponding to those of the parts shown in FIG. 3 are designated by the same reference numerals, and detailed description thereof will be omitted. FIG. 2 is an equivalent view of the π-type bandpass circuit according to the present invention. The capacitor C 7 is the collector capacitance of the element Q 1 , the capacitor C 8 is the input capacitance of the element Q 3 , and the capacitor C 9 is VHF. The capacitance in the local oscillation circuit and the capacitor C 10 indicate the capacitance in the VHF portion mixing tuning circuit.
考案の効果 上述の実施例に示す様に本考案によって、部品点数を２
点削減させる事ができる。このような部品の削減はチュ
ーナの小型化に役立つ。また、材料及び加工費のコスト
低減に役立つなど実用的価値が大きい。Effect of the Invention As shown in the above-mentioned embodiment, the present invention reduces the number of parts to two.
The points can be reduced. Such reduction of parts helps miniaturize the tuner. In addition, it is of great practical value as it helps reduce the cost of materials and processing costs.
第１図は本考案に係るチューナの実施例の要部回路図、
第２図は本考案に係る実施例のπ型帯域通過回路等価回
路図、及び第３図は、従来の要部回路図である。 Ｑ1…ＵＨＦ混合用素子、 Ｑ2…ダイオード、 Ｑ3…ＶＨＦ混合素子、 Ｃ4…ＵＨＦ・ＩＦ結合用コンデンサ、 Ｌ…コイル。FIG. 1 is a circuit diagram of a main part of an embodiment of a tuner according to the present invention,
FIG. 2 is an equivalent circuit diagram of a .pi.-type bandpass circuit according to an embodiment of the present invention, and FIG. 3 is a conventional essential circuit diagram. Q 1 ... UHF mixing element, Q 2 ... Diode, Q 3 ... VHF mixing element, C 4 ... UHF / IF coupling capacitor, L ... Coil.
Claims (1)
をＵＨＦ混合用素子のコレクタ容量及び接地用バイアス
容量を含む静電容量、又他方の脚部をＵＨＦ・ＩＦ結合
容量とＶＨＦ混合用素子の入力容量を含む静電容量によ
りそれぞれ構成したことを特徴とするテレビジョン用チ
ューナ。1. An intermediate frequency π-type bandpass circuit has one leg portion having a capacitance including a collector capacitance of a UHF mixing element and a bias capacitance for grounding, and the other leg portion having a UHF / IF coupling capacitance and VHF. A tuner for television, characterized in that each of the tuners is configured by an electrostatic capacity including an input capacity of a mixing element.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1989038909U JPH0625067Y2 (en) | 1989-03-31 | 1989-03-31 | Television tuner |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1989038909U JPH0625067Y2 (en) | 1989-03-31 | 1989-03-31 | Television tuner |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02130134U JPH02130134U (en) | 1990-10-26 |
| JPH0625067Y2 true JPH0625067Y2 (en) | 1994-06-29 |
Family
ID=31547338
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1989038909U Expired - Lifetime JPH0625067Y2 (en) | 1989-03-31 | 1989-03-31 | Television tuner |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0625067Y2 (en) |
-
1989
- 1989-03-31 JP JP1989038909U patent/JPH0625067Y2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02130134U (en) | 1990-10-26 |
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