JPH0233814A - Input switching device - Google Patents
Input switching deviceInfo
- Publication number
- JPH0233814A JPH0233814A JP18131988A JP18131988A JPH0233814A JP H0233814 A JPH0233814 A JP H0233814A JP 18131988 A JP18131988 A JP 18131988A JP 18131988 A JP18131988 A JP 18131988A JP H0233814 A JPH0233814 A JP H0233814A
- Authority
- JP
- Japan
- Prior art keywords
- input
- terminals
- group
- circuit
- ground
- 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.)
- Pending
Links
- 230000006866 deterioration Effects 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 4
- 239000003990 capacitor Substances 0.000 description 1
- 230000000593 degrading effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000005236 sound signal Effects 0.000 description 1
Landscapes
- Keying Circuit Devices (AREA)
- Circuits Of Receivers In General (AREA)
- Signal Processing Not Specific To The Method Of Recording And Reproducing (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は複数のオーデイ信号やビデオ信号の内から１個
を選択する入力切換装置に関し、特にクロストークの発
生を防止した装置に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an input switching device for selecting one of a plurality of audio signals or video signals, and particularly to a device that prevents the occurrence of crosstalk.
この種の入力切換装置として、第３図に示す回路がある
。この回路は、複数入力信号が入力する入力切換回路１
から２系統の信号を選択して切換回路２に送出し、この
切換回路２においてその一方を増幅器３に送出して内部
に取り込むと共にモニタ用としてモニタ端子４に送出し
、他方をコピー用端子５に送り出すようにしたものであ
る。６は切換回路２のスイッチ２１〜２４を制御するＣ
ＰＵ、７は操作部である。As this type of input switching device, there is a circuit shown in FIG. This circuit is an input switching circuit 1 to which multiple input signals are input.
Two systems of signals are selected and sent to the switching circuit 2, and in this switching circuit 2, one of them is sent to the amplifier 3 and taken in internally, and the other is sent to the monitor terminal 4 for monitoring, and the other is sent to the copying terminal 5. It was designed to be sent to 6 is C that controls the switches 21 to 24 of the switching circuit 2;
PU, 7 is an operation unit.
この装置では、ＣＰＵ６により入力切換回路ｌの第１群
１１の入力端子から１個がスイッチ１１１で選択されて
切換回路２のスイッチ２１に入力し、第２群１２の入力
端子からも同様に１個がスイッチ１２１で選択されて切
換回路２のスイッチ２３に入力する。そして、このスイ
ッチ２１．２３の切換及びスイッチ２２．２４の同−Ｃ
ＰＵ６による切換により、一方は増幅器３とモニタ端子
４に、他方はコピー用端子５に、各々出力する。In this device, one input terminal from the first group 11 of the input switching circuit 1 is selected by the CPU 6 by the switch 111 and inputted to the switch 21 of the switching circuit 2, and similarly one terminal from the input terminal of the second group 12 is selected by the CPU 6. The selected one is selected by the switch 121 and inputted to the switch 23 of the switching circuit 2. Then, the switching of this switch 21.23 and the switching of switch 22.24 -C
By switching by the PU 6, one output is output to the amplifier 3 and the monitor terminal 4, and the other output is output to the copy terminal 5.
ところが、この装置では、入力切換回路１の第１群１１
又は第２群１２に２個以上の信号が同時に印加すると、
相互間でクロストークが発生して、他方に対してノイズ
として混入し、信号品質を劣化させるという問題があっ
た。特に、周波数の高い映像信号については顕著であっ
た。However, in this device, the first group 11 of the input switching circuit 1
Or when two or more signals are applied to the second group 12 at the same time,
There is a problem in that crosstalk occurs between the two and is mixed into the other as noise, degrading the signal quality. This was particularly noticeable for high-frequency video signals.
本発明はこのような点に鑑みたもので、その目的は複数
の信号を同時に印加しても、クロストークが発生しない
ようにすることである。The present invention has been made in view of these points, and its purpose is to prevent crosstalk from occurring even when a plurality of signals are applied simultaneously.
このために本発明は、１群の複数の入力端子から１個の
入力端子を選択する入力切換装置において、
上記１群の複数の入力端子をショート回路の出力端子に
格別に接続し、該ショート回路の出力端子の上記選択し
た入力端子に対応する１個を残して他をアースにショー
トするようにした。To this end, the present invention provides an input switching device for selecting one input terminal from a group of a plurality of input terminals, in which the plurality of input terminals of the group are specially connected to the output terminal of a short circuit, and the All but one of the output terminals of the circuit corresponding to the selected input terminal were short-circuited to ground.
〔実施例〕
以下、本発明の実施例について説明する。第１図はその
一実施例を示す回路図である。第３図におけるものと同
様のものには同一の符号を付した。[Examples] Examples of the present invention will be described below. FIG. 1 is a circuit diagram showing one embodiment thereof. Components similar to those in FIG. 3 are given the same reference numerals.
本実施例では、ショート回路８を新たに設けて、その出
力で入力切換回路１の入力端のラインをアースにショー
トするようにした。In this embodiment, a short circuit 8 is newly provided, and its output short-circuits the line at the input end of the input switching circuit 1 to ground.
このショート回路８は第２図に示すように、ｎビットの
入力端子Ａｌ−Ａｎと、８木の出力端子ＹＯ，Ｙｌ、Ｙ
２．Ｙ３．Ｙ４．Ｙ５．Ｙ６．Ｙ７を有する。そして、
入力端子Ａ１〜Ａｎの論理によって、出力端子ＹＯ−Ｙ
３のいずれか１個とＹ４〜Ｙ７のいずれか１個のみがオ
ーブン（’ＨＪ）となり、他の全てがアースレベル（ｒ
ｒ、」）となるように制御される。このショート回路８
としては、例えばＴＣ７４１１Ｃ１３８ＡＰのＭＯＳデ
コーダが使用できる。As shown in FIG. 2, this short circuit 8 has an n-bit input terminal Al-An and eight tree output terminals YO, Yl, Y.
2. Y3. Y4. Y5. Y6. It has Y7. and,
Depending on the logic of the input terminals A1 to An, the output terminals YO-Y
Only one of 3 and one of Y4 to Y7 becomes an oven ('HJ), and all others are earth level (r
r,''). This short circuit 8
For example, a TC7411C138AP MOS decoder can be used.
従って、ＣＰＵ６によってショート回路８を制御するこ
とにより、入力切換回路１の第１群１１の入力端子から
は切換回路２のスイッチ２１に接続される１個のみがア
ースから浮き他はアースされるので、その第１群１１内
における端子相互間にクロストークが発生することはな
い。また、第２群１２においても切換回路２のスイッチ
２３に接続される１個のみがアースから浮き他はアース
にショートされるので、同様に端子相互間のクロストー
クが発生することはない。Therefore, by controlling the short circuit 8 by the CPU 6, only one of the input terminals of the first group 11 of the input switching circuit 1 connected to the switch 21 of the switching circuit 2 is lifted from the ground, and the others are grounded. , crosstalk does not occur between the terminals in the first group 11. Further, in the second group 12, only one terminal connected to the switch 23 of the switching circuit 2 is floating from the ground, and the others are short-circuited to the ground, so that crosstalk between the terminals similarly does not occur.
なお、ショート回路８においてショートする際に、直接
アースにショートすると人力切換回路１に接続される入
力回路（図示せず）の出力インピーダンス如何によって
は、その入力回路の素子に損傷を与える場合があるので
、コンデンサを介してアースする方が好ましい。Note that when a short circuit occurs in the short circuit 8, if it shorts directly to the ground, it may damage the elements of the input circuit (not shown) depending on the output impedance of the input circuit (not shown) connected to the manual switching circuit 1. Therefore, it is preferable to ground through a capacitor.
以上から本発明によれば、選択した信号以外はアースに
ショートされるので、クロストークの発生する虞はなく
、信号品質が劣化することを防止することができる。As described above, according to the present invention, signals other than the selected signal are short-circuited to the ground, so there is no risk of crosstalk occurring, and deterioration of signal quality can be prevented.
第１図は本発明の一実施例の入力切換装置の回路図、第
２図はショート回路の説明図、第３図は従来の入力切換
装置の回路図である。
１・・・入力切換回路、２・・・切換回路、３・・・増
幅器、４・・・モニタ端子、５・・・コピ一端子、６・
・・ＣＰＵ、７・・・操作部、８・・・ショート回路。
代理人 弁理士 長 尾 常 明
第１
図
第２
図FIG. 1 is a circuit diagram of an input switching device according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of a short circuit, and FIG. 3 is a circuit diagram of a conventional input switching device. DESCRIPTION OF SYMBOLS 1... Input switching circuit, 2... Switching circuit, 3... Amplifier, 4... Monitor terminal, 5... Copy terminal, 6...
...CPU, 7...Operation unit, 8...Short circuit. Agent Patent Attorney Tsuneaki Nagao Figure 1 Figure 2
Claims (2)
択する入力切換装置において、 上記１群の複数の入力端子をショート回路の出力端子に
格別に接続し、該ショート回路の出力端子の上記選択し
た入力端子に対応する１個を残して他をアースにショー
トするようにしたことを特徴とする入力切換装置。(1) In an input switching device that selects one input terminal from a plurality of input terminals in one group, the plurality of input terminals in the first group are specially connected to an output terminal of a short circuit, and the output terminal of the short circuit is An input switching device characterized in that one of the terminals corresponding to the selected input terminal is left and the others are short-circuited to ground.
を同一の制御手段で行うようにしたことを特徴とする入
力切換装置。(2) An input switching device characterized in that the control of the short circuit and the selection of the input terminal are performed by the same control means.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18131988A JPH0233814A (en) | 1988-07-20 | 1988-07-20 | Input switching device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18131988A JPH0233814A (en) | 1988-07-20 | 1988-07-20 | Input switching device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0233814A true JPH0233814A (en) | 1990-02-05 |
Family
ID=16098602
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18131988A Pending JPH0233814A (en) | 1988-07-20 | 1988-07-20 | Input switching device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0233814A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2015053577A (en) * | 2013-09-06 | 2015-03-19 | 日本電波工業株式会社 | Oscillator and method of manufacturing oscillator |
-
1988
- 1988-07-20 JP JP18131988A patent/JPH0233814A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2015053577A (en) * | 2013-09-06 | 2015-03-19 | 日本電波工業株式会社 | Oscillator and method of manufacturing oscillator |
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