JPH03125579A - Video signal switching circuit - Google Patents
Video signal switching circuitInfo
- Publication number
- JPH03125579A JPH03125579A JP26436889A JP26436889A JPH03125579A JP H03125579 A JPH03125579 A JP H03125579A JP 26436889 A JP26436889 A JP 26436889A JP 26436889 A JP26436889 A JP 26436889A JP H03125579 A JPH03125579 A JP H03125579A
- Authority
- JP
- Japan
- Prior art keywords
- video signal
- input
- switching
- output
- pattern
- 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
- 230000015654 memory Effects 0.000 claims description 10
- 238000010586 diagram Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 2
- 230000001360 synchronised effect Effects 0.000 description 2
- 230000004913 activation Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、テレビジョン受像機、ＶＴＲ等の選局及び外
部入力信号の切替えによる映像信号切替回路に関するも
のである。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a video signal switching circuit for selecting channels in television receivers, VTRs, etc. and switching external input signals.
従来の技術
近年、映像ソースの多様化に伴ない映像信号の切替回路
が、テレビジョン受像機等に内蔵される事が多い。たと
えば、（ｒＡＶシステム技術」テレビ受信向上委員会編
集２ 目木放送会事務局Ｐ、Ｐ１２８〜１４４ 昭和
６０年１１月発行）に記述がある。2. Description of the Related Art In recent years, with the diversification of video sources, video signal switching circuits are often built into television receivers and the like. For example, there is a description in (rAV System Technology, Edited by Television Reception Improvement Committee 2, Meki Broadcasting Association Secretariat P, P128-144, Published November 1985).
以下、図面を参照しながら、上述した従来の映像信号切
替回路の一例について説明する。第３図は従来の映像信
号切替回路のブロック図である。An example of the conventional video signal switching circuit described above will be described below with reference to the drawings. FIG. 3 is a block diagram of a conventional video signal switching circuit.
図において、■は外部映像信号入力端子、２はアンテナ
で受信した電波の中から所望の映像信号を選局するチュ
ーナー、３は映像信号の入力切替スイ・２チ、７は映像
信号の出力端子、１３は入力する映像信号の切替を制御
する入力切替制御手段である。In the figure, ■ is an external video signal input terminal, 2 is a tuner that selects a desired video signal from the radio waves received by the antenna, 3 is a video signal input switch 2, and 7 is a video signal output terminal. , 13 is input switching control means for controlling switching of input video signals.
以上のように構成された映像信号切替回路について、以
下その動作について説明する。The operation of the video signal switching circuit configured as described above will be described below.
入力切替制御手段１３ば、キーによる入力等、外部から
の指示に応じて、映像信号の入力切替スイッチ３を外部
映像信号の入力端子１の側か、チューナー２の側か、ど
ちら側に接続するか、もしくは、チューナー２の内部の
選局回路部をどのように制御するかを決め、制御信号を
出力する。所望の映像信号は出力端子７から出力される
。The input switching control means 13 connects the video signal input selection switch 3 to either the external video signal input terminal 1 side or the tuner 2 side in response to an external instruction such as input by a key. Alternatively, it decides how to control the tuning circuit section inside the tuner 2 and outputs a control signal. The desired video signal is output from the output terminal 7.
発明が解決しようとする課題
しかし、上記のような構成では、映像信号の切替の前後
で、同期信号の関係や輝度レベル等全く異なる映像信号
を一瞬に切り替えるため、同期が一時的に不安定になっ
て、例えば、垂直方向に画面がめくれたり、輝度が急に
変化したりする課題を有していた。Problems to be Solved by the Invention However, with the above configuration, the synchronization becomes temporarily unstable because video signals that have completely different synchronization signal relationships and brightness levels are switched before and after the video signal is switched. For example, there were problems such as the screen turning over in the vertical direction or sudden changes in brightness.
本発明は、上記課題に鑑み、滑らかで画面乱れのない映
像の切替わりが可能な映像信号切替回路を提供するもの
である。In view of the above-mentioned problems, the present invention provides a video signal switching circuit that can switch video smoothly and without screen disturbance.
課題を解決するための手段
上記課題を解決するために本発明の映像切替回路は、映
像信号の入力端子と、入力する映像信号の内容を切替え
る制御信号を発生する入力切替制御手段と、入力された
映像信号と固定値の三者から一つを選択する出力選択ス
イッチと、上記出力選択スイッチに接続され映像信号の
１画面分を記録する１画面メモリと、上記映像信号の入
力端子に接続されて垂直同期パルス、水平同期パルス、
クロックを発生する同期発生回路部と、上記出力選択ス
イッチの切替えを制御する出力切替制御部という構成を
備えたものである。Means for Solving the Problems In order to solve the above problems, the video switching circuit of the present invention has an input terminal for a video signal, an input switching control means for generating a control signal for switching the content of the input video signal, and an input terminal for inputting the video signal. an output selection switch for selecting one of the three video signals and a fixed value; a one-screen memory connected to the output selection switch for recording one screen of the video signal; and a one-screen memory connected to the input terminal for the video signal. vertical sync pulse, horizontal sync pulse,
This device includes a synchronization generation circuit section that generates a clock, and an output switching control section that controls switching of the output selection switch.
作用
本発明は上記した構成によって、入力切替時にいったん
全画面を黒っぽい色にした後、切替後の動画像に画面送
りの要領で徐々に切替えていくもので、同期関係や輝度
等の変化が滑らかで画面の乱れのない映像信号の切替え
が実現できる。Effect of the Invention With the above-described configuration, the present invention makes the entire screen a blackish color when switching inputs, and then gradually switches to the switched moving image in the same way as the screen advances, so that changes in synchronization relationships, brightness, etc. are smooth. It is possible to switch video signals without disturbing the screen.
実施例
以下、本発明の一実施例の映像信号切替回路について図
面を参照しながら説明する。Embodiment Hereinafter, a video signal switching circuit according to an embodiment of the present invention will be described with reference to the drawings.
第１は、本発明の一実施例における映像信号切替回路の
ブロック図を示すものである。The first one shows a block diagram of a video signal switching circuit in an embodiment of the present invention.
第１図において、１は外部映像信号の入力端子、２はチ
ューナー、３は映像信号の入力切替スイッチ、７は映像
信号の出力端子、１３は入力する映像信号の切替えを制
御する入力切替制御手段で、以上は従来例で説明した第
３図と同様である。４は入力切替え時に画面全体にぬる
色を決める固定値データ入力部、５は２入力ｌ出力選択
スイッチ、６は１画面メモリ、８は同期発生回路部、９
．１０．１１は同期発生回路部８の出力端子で各々クロ
ック出力端子、水平同期パルス出力端子、垂直同期パル
ス出力端子、１２はカウンタで出力選択スイッチ５の制
御を行う。In FIG. 1, 1 is an external video signal input terminal, 2 is a tuner, 3 is a video signal input changeover switch, 7 is a video signal output terminal, and 13 is input switching control means for controlling switching of input video signals. The above is the same as that shown in FIG. 3 described in the conventional example. 4 is a fixed value data input section that determines the color to be applied to the entire screen when switching inputs, 5 is a 2-input/1-output selection switch, 6 is a 1-screen memory, 8 is a synchronization generation circuit section, 9
．． Reference numerals 10 and 11 are output terminals of the synchronization generation circuit section 8, which are a clock output terminal, a horizontal synchronization pulse output terminal, and a vertical synchronization pulse output terminal, respectively; 12 is a counter that controls the output selection switch 5;
以上のように構成された映像信号切替回路について、以
下その動作について説明する。第２図に画面送りの模式
図を示す。全体は映像信号の出力端子７からの映像信号
をモニターテレビの画面に出力した場合のスクリーン面
を示している。画面Ａ、Ｂば出力選択スイッチ５が映像
信号の入力切替スイッチ３側に接続されている期間の映
像であり、Ｃは出力選択スィッチ５固定値データ入力部
４に接続されている期間である。The operation of the video signal switching circuit configured as described above will be described below. Figure 2 shows a schematic diagram of screen switching. The whole figure shows the screen surface when the video signal from the video signal output terminal 7 is output to the screen of the monitor television. Screens A and B are images during the period when the output selection switch 5 is connected to the input changeover switch 3 side of the video signal, and screen C is the image during the period when the output selection switch 5 is connected to the fixed value data input section 4.
まず、通常は第２図（イ）の状態のように、出力選択ス
イッチ５は入力切替スイッチ３の側に接続され、入力切
替スイッチ３から入力された映像信号は１画面メモリ６
を通して映像信号の出力端子７に出力される。そして、
入力切替制御手段１３は、映像信号を切替える指示があ
った場合、ますカウンタ１２に起動パルスを送り、カウ
ンタ１２を通して出力選択スイッチ５を固定値データ入
力部４の側に接続する。これが第２図（ロ）の状態であ
る。その後、入力切替制御手段１３は入力切替スイッチ
３、もしくはチューナー２を制御して、所望の映像信号
へと切替える。一方、カウンタ１２は、先の起動パルス
により初期化を行い、クロック出力端子９のクロックや
、水平同期パルス出力端子１０のパルス、垂直同期パル
ス出力端子１１のパルスを計数して、画面Ｂ、Ｃの各々
の出画位置２期間を決め、出力選択スイッチ５を制御す
る。その−例の過程が第２図（ハ）の状態であり、最終
的に第２図（ニ）の状態となり、映像信号の入力切替が
終わる。なお、画面Ｂ、Ｃの出画位置２期間はカウンタ
１２の計数の方法により、任意に変えることができる。First, normally, the output selection switch 5 is connected to the input selection switch 3 side, as in the state shown in FIG.
The video signal is output to the video signal output terminal 7 through the video signal. and,
When the input switching control means 13 receives an instruction to switch the video signal, it sends a starting pulse to the counter 12 and connects the output selection switch 5 to the fixed value data input section 4 through the counter 12. This is the state shown in FIG. 2 (b). Thereafter, the input switching control means 13 controls the input switching switch 3 or the tuner 2 to switch to a desired video signal. On the other hand, the counter 12 is initialized by the previous activation pulse, counts the clock at the clock output terminal 9, the pulse at the horizontal synchronization pulse output terminal 10, and the pulse at the vertical synchronization pulse output terminal 11, 2 periods for each image output position are determined, and the output selection switch 5 is controlled. The process of this example is the state shown in FIG. 2(C), and finally the state shown in FIG. 2(D) is reached, and the input switching of the video signal is completed. Note that the two periods of the image output positions of screens B and C can be arbitrarily changed by the counting method of the counter 12.
以上のように本実施例によれば、入力を切替える時に、
まず画面全体を黒っぽい色、−・色にした後、切替後の
動画像を画面送りの要領で順次切替えることにより、次
のような効果がある。As described above, according to this embodiment, when switching inputs,
First, the entire screen is changed to a blackish color and then to a --color, and then the video images after switching are sequentially switched in the same manner as screen forwarding, thereby producing the following effects.
（１）入力切替直後で、垂直方向の偏向パルスが乱れる
が、画面全体が一色であるので、画面の乱れが目立たな
い。(1) Immediately after input switching, the vertical deflection pulse is disturbed, but since the entire screen is one color, the disturbance on the screen is not noticeable.
（２）同期関係が入力切替前後で連続的になり、画面が
流れにくい。(2) The synchronization relationship becomes continuous before and after input switching, making it difficult for the screen to flow.
同期発生回路部８の同期パルスの出力位相が変化しても
、１画面メモリ６も同じ同期パルスで読出すため、同期
パルスに対する映像出力の位相関係は乱れない。Even if the output phase of the synchronization pulse from the synchronization generation circuit section 8 changes, the single-screen memory 6 is also read out with the same synchronization pulse, so the phase relationship of the video output with respect to the synchronization pulse is not disturbed.
（３）順次に画面を切替えるため、輝度変化等に対する
ＣＲＴ制御回路の変化が滑らかになる。(3) Since screens are switched sequentially, changes in the CRT control circuit due to changes in brightness, etc. become smooth.
なお、一画面メモリ６としては、テレビジョン受像機や
ＶＴＲ等で、従来、付加機能として、スチル（−時静止
）を行っていたものと同様のメモリが使用できる。特に
Ｉ ＤＴＶ等大容量のメモリが使用されているシステム
では、コスト上昇なしに、このような映像信号切替回路
の実現が可能である。As the one-screen memory 6, it is possible to use a memory similar to that used in television receivers, VTRs, and the like, which conventionally performs still (-time freeze) as an additional function. Particularly in systems such as IDTVs that use large-capacity memories, it is possible to implement such a video signal switching circuit without increasing costs.
又、Ｉ ＤＴＶ等のデジタルテレビにおいては、映像切
替時に種々の演算のやり直しや、検出のやり直しが必要
な場合が多く、本構成のような映像信号切替回路を導入
すれば、より滑らかな切替えが可能になる。In addition, in digital televisions such as IDTV, it is often necessary to redo various calculations and redo detection when switching images, and by introducing a video signal switching circuit like this configuration, smoother switching can be achieved. It becomes possible.
発明の効果
以上のように本発明は、映像信号の入力端子と、入力す
る映像信号の内容を切替える制御信号を発生する入力切
替制御手段と、入力された映像信号と固定値の三者から
一つを選択する出力選択スインチと、上記出力選択スイ
ッチに接続され映像信号の１画面分を記録する１画面メ
モリと、上記映像信号の入力端子に接続されて垂直同期
パルス、水平同期パルス、クロックを発生する同期発生
回路部と、上記出力選択スイッチの切替えを制御する出
力切替制御部とを設けることにより、滑らかで画面の乱
れがない映像信号の切替えを実現することができる。Effects of the Invention As described above, the present invention provides an input terminal for a video signal, an input switching control means for generating a control signal for switching the content of the input video signal, and an input video signal and a fixed value. an output selection switch that selects the output selection switch; a single-screen memory connected to the output selection switch that records one screen of the video signal; By providing a synchronization generating circuit section that generates synchronization and an output switching control section that controls switching of the output selection switch, it is possible to realize smooth switching of video signals without any screen disturbance.
第１図は本発明の一実施例における映像信号切替回路の
ブロック図、第２図は第１図の回路動作を説明するため
の模式図、第３図は従来の映像信号切替回路のブロック
図である。
■・・・・−・外部映像信号入力端子、２−・・−チュ
ーナ、３・・・・・入力切替スイ・７チ、４−・・固定
値データ入力部、５・・・・・・出力選択スイッチ、６
・・・・・１画面メモリ、７・−・・・映像信号出力端
子、８・・・・・・同期発生回路部、９・・・・・・ク
ロック出力端子、ｌＯ・・・・・・水平同期パルス出力
端子、１１・・・正直同期パルス出力端子、１２・・・
・・・カウンタ、１３・・・入力切替制御手段。FIG. 1 is a block diagram of a video signal switching circuit according to an embodiment of the present invention, FIG. 2 is a schematic diagram for explaining the circuit operation of FIG. 1, and FIG. 3 is a block diagram of a conventional video signal switching circuit. It is. ■・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・TUNENER, 3・・・・Input switching switch 7, 4・・・・Fixed value data input section, 5・・・・Output selection switch, 6
...1 screen memory, 7...Video signal output terminal, 8...Synchronization generation circuit section, 9...Clock output terminal, lO... Horizontal synchronous pulse output terminal, 11... Honest synchronous pulse output terminal, 12...
. . . Counter, 13 . . . Input switching control means.
Claims (4)
を切替える制御信号を発生する入力切替制御手段と、入
力された映像信号と固定値の二者から一つを選択する出
力選択スイッチと、上記出力選択スイッチに接続され映
像信号の１画面分を記録する１画面メモリと、上記映像
信号の入力端子に接続されて垂直同期パルス、水平同期
パルス、クロックを発生する同期発生回路部と、上記出
力選択スイッチの切替えを制御する出力切替制御部とを
備えたことを特徴とする映像信号切替回路。(1) An input terminal for a video signal, an input switching control means that generates a control signal to switch the content of the input video signal, and an output selection switch that selects one of the input video signal and a fixed value. , a one-screen memory connected to the output selection switch to record one screen of the video signal, and a synchronization generation circuit connected to the input terminal of the video signal to generate a vertical synchronization pulse, a horizontal synchronization pulse, and a clock; A video signal switching circuit comprising: an output switching control section that controls switching of the output selection switch.
御手段により選局回路部、もしくは上記選局回路部の出
力と外部映像信号の入力端子を切替える入力切替スイッ
チを制御することにより行うことを特徴とする特許請求
の範囲第１項記載の映像信号切替回路。(2) Switching the content of the input video signal by controlling the channel selection circuit section or an input changeover switch that switches between the output of the channel selection circuit section and the input terminal of the external video signal using an input switching control means. A video signal switching circuit according to claim 1, characterized in that:
計数するカウンタと、上記カウンタを起動させる信号を
入力切替制御手段から取り込む起動パルス入力端子より
なる特許請求の範囲第１項記載の映像信号切替回路。(3) The output switching control section comprises a counter for counting the output of the synchronization generating circuit section, and a starting pulse input terminal for receiving a signal for starting the counter from the input switching control means. Video signal switching circuit.
パルスの供給時期を、入力信号の切替えよりも、一垂直
同期期間以上早く行うことを特徴とする特許請求の範囲
第３項記載の映像信号切替回路。(4) The video according to claim 3, characterized in that the input switching control means supplies the starting pulse to the output switching control unit at least one vertical synchronization period earlier than the switching of the input signal. Signal switching circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26436889A JPH03125579A (en) | 1989-10-11 | 1989-10-11 | Video signal switching circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26436889A JPH03125579A (en) | 1989-10-11 | 1989-10-11 | Video signal switching circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03125579A true JPH03125579A (en) | 1991-05-28 |
Family
ID=17402186
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP26436889A Pending JPH03125579A (en) | 1989-10-11 | 1989-10-11 | Video signal switching circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03125579A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100362609B1 (en) * | 2000-11-30 | 2002-11-29 | 삼성전자 주식회사 | Dome camera apparatus |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6472671A (en) * | 1987-09-04 | 1989-03-17 | Thomson Brandt Gmbh | Television receiver circuit device for changing television channel without trouble |
| JPH01218274A (en) * | 1988-02-26 | 1989-08-31 | Sony Corp | Television receiver |
-
1989
- 1989-10-11 JP JP26436889A patent/JPH03125579A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6472671A (en) * | 1987-09-04 | 1989-03-17 | Thomson Brandt Gmbh | Television receiver circuit device for changing television channel without trouble |
| JPH01218274A (en) * | 1988-02-26 | 1989-08-31 | Sony Corp | Television receiver |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100362609B1 (en) * | 2000-11-30 | 2002-11-29 | 삼성전자 주식회사 | Dome camera apparatus |
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