JPS6387893A - Color difference signal switching circuit - Google Patents
Color difference signal switching circuitInfo
- Publication number
- JPS6387893A JPS6387893A JP23354486A JP23354486A JPS6387893A JP S6387893 A JPS6387893 A JP S6387893A JP 23354486 A JP23354486 A JP 23354486A JP 23354486 A JP23354486 A JP 23354486A JP S6387893 A JPS6387893 A JP S6387893A
- Authority
- JP
- Japan
- Prior art keywords
- color difference
- difference signal
- signal
- circuit
- switching
- 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.)
- Granted
Links
- 238000010586 diagram Methods 0.000 description 6
Landscapes
- Processing Of Color Television Signals (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、映像色差信号に文字色差信号をデジタル領域
において埋め込む切り替え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 switching circuit for embedding a character color difference signal in a video color difference signal in a digital domain.
従来の技術
近年、デジタル技術の発達と共に、映像信号と文字信号
の切シ替えもデジタル領域で行われようとしている。以
下、図面を参照しながら、上述した切り替え回路の一例
について説明する。BACKGROUND OF THE INVENTION In recent years, with the development of digital technology, switching between video signals and character signals is also being performed in the digital domain. An example of the switching circuit described above will be described below with reference to the drawings.
第３図、第４図、第５図は、従来のデジタル領域におけ
る切り替えスイッチを示すものである。FIGS. 3, 4, and 5 show conventional changeover switches in the digital domain.
第３図において、３は映像色差信号を減衰させる掛算回
路、４は文字色差信号を減衰させる掛算回路、５は信号
Ｊと信号Ｋを加算する加算回路である。以上のように構
成された切り替え回路について、その動作を第４図、第
６図の波形をもとに説明する。第３図の掛算回路１は、
映像色差信号（波形Ｆ）を切り替え信号２（波形Ｇ）で
減衰させる回路でその出力信号は波形Ｊのようになる。In FIG. 3, 3 is a multiplication circuit that attenuates the video color difference signal, 4 is a multiplication circuit that attenuates the character color difference signal, and 5 is an addition circuit that adds signal J and signal K. The operation of the switching circuit configured as described above will be explained based on the waveforms shown in FIGS. 4 and 6. The multiplication circuit 1 in FIG. 3 is
This circuit attenuates the video color difference signal (waveform F) with switching signal 2 (waveform G), and its output signal becomes waveform J.
掛算回路２は、文字色差信号（波形Ｈ）を切り替え信号
１（波形Ｉ）で減衰させる回路であシ、その出力信号は
波形にのようになる。加算回路は、掛算回路１と掛算回
路２の出力信号を加算する回路で、その出力信号は波形
りのようになり、映像色差信号（波形Ｆ）と文字色差信
号（波形Ｈ）が、切り替え信号１，２のもとに、切り替
えられる。The multiplication circuit 2 is a circuit that attenuates the character color difference signal (waveform H) with the switching signal 1 (waveform I), and its output signal has the following waveform. The adder circuit is a circuit that adds the output signals of the multiplier circuit 1 and the multiplier circuit 2, and the output signal has a waveform as shown in FIG. It can be switched under 1 and 2.
発明が解決しようとする問題点
しかしながら、上記のような構成では、切り替え信号１
，２のピット数を少なくすると出力映像がジッターを起
こすために、切シ替え信号１，２０ビット数が多く必要
とされ、それで掛算回路１゜２の回路規模が、非常に大
きくなるという問題点を有していた。Problems to be Solved by the Invention However, in the above configuration, the switching signal 1
, 2 causes jitter in the output video, so a large number of switching signals 1 and 20 bits are required, which causes the circuit scale of the multiplication circuit 1.2 to become extremely large. It had
本発明は、上記問題点に鑑み、デジタル領域での映像色
差信号と文字色差信号を掛算回路を用ずに切り替える切
り替え回路を提供するものである。In view of the above problems, the present invention provides a switching circuit that switches between a video color difference signal and a character color difference signal in the digital domain without using a multiplication circuit.
問題点を解決するための手段
上記問題点を解決するために、本発明の切り替え回路は
、映像色差信号を減衰させる減算回路とその出力信号に
文字色差信号を加算する加算回路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 switching circuit of the present invention includes a subtraction circuit that attenuates the video color difference signal and an addition circuit that adds the character color difference signal to the output signal of the subtraction circuit. It is something.
作 用
本発明は、上記した構成によって、映像色差信号を切り
替え信号をもとに、減算回路にて減衰させ、その出力信
号に文字色差信号を加算することで、映像色差信号と文
字色差信号を切り替えることとなる。According to the above-described configuration, the present invention attenuates the video color difference signal in the subtraction circuit based on the switching signal, and adds the text color difference signal to the output signal, thereby attenuating the video color difference signal and the text color difference signal. Will have to switch.
実施例
以下本発明の一実施例について図面を参照しながら説明
する。第１図は、本発明の一実施例における切り替え回
路のブロック図を示すものである。EXAMPLE An example of the present invention will be described below with reference to the drawings. FIG. 1 shows a block diagram of a switching circuit in one embodiment of the present invention.
第１図において、１は映像色差信号を減衰させる減算回
路、２はその出力信号に文字色差信号を加算させる加算
回路である。In FIG. 1, 1 is a subtraction circuit that attenuates a video color difference signal, and 2 is an addition circuit that adds a character color difference signal to its output signal.
以上のように構成された切シ替え回路について、以下第
１図、第２図及び第６図を用いてその動作を説明する。The operation of the switching circuit configured as described above will be explained below with reference to FIGS. 1, 2, and 6.
まず、第２図のＡに示されるような、映像色差信号及び
、Ｂに示されるような、切り替え信号が第１図の１の減
算回路に加えられる。この減算回路は、第６図のように
加算器、ＥＸＯＲ、ＡＮＤ 、ＮＯＲ。First, a video color difference signal as shown in A in FIG. 2 and a switching signal as shown in B in FIG. 1 are applied to the subtraction circuit 1 in FIG. This subtraction circuit includes an adder, EXOR, AND, and NOR as shown in FIG.
で構成され、信号Ａのような入力されたデジタル信号（
第６図においては、信号Ａは反転二進としている）の最
上位ビットで、その符号を識別し、その符号が正である
ならば、信号Ｂの切り替え信号をＥＸＯＲを用いて反転
し、キャリーと共に信号Ａに加算することで減算回路と
して働かせその後、その減算された結果の最上位ビット
で負の数とならないように、リミッタをかけている。ま
た信号Ａが負であるならば、そのまま信号Ｂの切り替え
信号を加算し、その結果が正の数とならないように、リ
ミッタをかけている。その結果として信号りのようにな
る。次にその信号りに、文字色差信号である信号Ｃを第
１図の２の加算回路で加算し、信号Ｅとなり、映像色差
信号と文字色差信号が切替えられた。consists of an input digital signal such as signal A (
In FIG. 6, the sign is identified by the most significant bit of the signal A (signal A is inverted binary), and if the sign is positive, the switching signal of signal B is inverted using EXOR and carried. A limiter is applied to prevent the most significant bit of the subtracted result from becoming a negative number. Further, if signal A is negative, the switching signal of signal B is added as is, and a limiter is applied so that the result does not become a positive number. The result is something like a traffic light. Next, the signal C, which is a text color difference signal, is added to that signal by an adder circuit 2 in FIG. 1, resulting in a signal E, and the video color difference signal and the text color difference signal are switched.
以上のように本実施例によれば、従来の掛算回路のよう
な大規模の回路を用いずに、減算回路と加算回路で、映
像色差信号と文字色差信号を切り替えることができる。As described above, according to this embodiment, the video color difference signal and the text color difference signal can be switched using the subtraction circuit and the addition circuit without using a large-scale circuit such as a conventional multiplication circuit.
発明の効果
以上のように、本発明は、減算回路、加算回路により映
像色差信号と文字色差信号を切り替えることができ、デ
ジタル領域においての映像色差信号と文字色差信号の切
り替えの実用化に効果大なるものがある。Effects of the Invention As described above, the present invention can switch between a video color difference signal and a text color difference signal using a subtraction circuit and an addition circuit, and is highly effective in practical application of switching between a video color difference signal and a text color difference signal in the digital domain. There is something.
第１図は本発明の一実施例における色差信号切シ替え回
路のブロック図、第２図はその信号波形図、第６図は同
要部の回路図、第３図は従来例の色差信号切り替え回路
の回路図、第４図、第６図はその信号波形図である。
１・・・・・・減算回路、２・・・・・・加算回路、Ａ
・・・・・・映像色差信号、Ｂ・・・・・・切シ替え信
号、Ｃ・・・・・・文字色差信号。
代理人の氏名 弁理士 中 尾 敏 男 ほか１名第３
図
１４図Fig. 1 is a block diagram of a color difference signal switching circuit according to an embodiment of the present invention, Fig. 2 is a signal waveform diagram thereof, Fig. 6 is a circuit diagram of the same main part, and Fig. 3 is a color difference signal of a conventional example. The circuit diagrams of the switching circuit, FIGS. 4 and 6, are signal waveform diagrams thereof. 1... Subtraction circuit, 2... Addition circuit, A
...Video color difference signal, B...Switching signal, C...Text color difference signal. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 3
Figure 14
Claims (2)
の結果にリミッタをかける減算回路および加算回路を備
えたことを特徴とする色差信号切り替え回路。(1) A color difference signal switching circuit comprising a subtraction circuit and an addition circuit that perform addition or subtraction depending on the sign of a video color difference signal and apply a limiter to the result.
え信号がｎ−１ビットのデジタル信号である特許請求の
範囲第１項記載の色差信号切り替え回路。(2) The color difference signal switching circuit according to claim 1, wherein the video color difference signal and the character color difference signal are n-bit digital signals, and the switching signal is an n-1 bit digital signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61233544A JPH0720253B2 (en) | 1986-10-01 | 1986-10-01 | Color difference signal switching circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61233544A JPH0720253B2 (en) | 1986-10-01 | 1986-10-01 | Color difference signal switching circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6387893A true JPS6387893A (en) | 1988-04-19 |
| JPH0720253B2 JPH0720253B2 (en) | 1995-03-06 |
Family
ID=16956719
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61233544A Expired - Lifetime JPH0720253B2 (en) | 1986-10-01 | 1986-10-01 | Color difference signal switching circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0720253B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04132472A (en) * | 1990-09-25 | 1992-05-06 | Sharp Corp | Character superimposing device |
| KR100239153B1 (en) * | 1991-12-06 | 2000-01-15 | 데이비드 제임스 해밀톤 | Method of preparing va mycorrhizae inoculant |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58159082A (en) * | 1982-03-16 | 1983-09-21 | Sharp Corp | Superposing device of character and pattern signals |
-
1986
- 1986-10-01 JP JP61233544A patent/JPH0720253B2/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58159082A (en) * | 1982-03-16 | 1983-09-21 | Sharp Corp | Superposing device of character and pattern signals |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04132472A (en) * | 1990-09-25 | 1992-05-06 | Sharp Corp | Character superimposing device |
| KR100239153B1 (en) * | 1991-12-06 | 2000-01-15 | 데이비드 제임스 해밀톤 | Method of preparing va mycorrhizae inoculant |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0720253B2 (en) | 1995-03-06 |
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