JPH0548552B2 - - Google Patents
Info
- Publication number
- JPH0548552B2 JPH0548552B2 JP59260149A JP26014984A JPH0548552B2 JP H0548552 B2 JPH0548552 B2 JP H0548552B2 JP 59260149 A JP59260149 A JP 59260149A JP 26014984 A JP26014984 A JP 26014984A JP H0548552 B2 JPH0548552 B2 JP H0548552B2
- Authority
- JP
- Japan
- Prior art keywords
- recording method
- level
- circuit
- signal
- narrowband
- 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
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
- G11B20/02—Analogue recording or reproducing
- G11B20/06—Angle-modulation recording or reproducing
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
Description
【発明の詳細な説明】
〔発明の技術分野〕
この発明は、例えば、ビデオテープレコーダ
（以下、VTRと称する）において、狭帯域記録方
式と広帯域記録方式を識別するのに好適な記録方
式識別回路に関する。[Detailed Description of the Invention] [Technical Field of the Invention] The present invention provides a recording method identification circuit suitable for identifying a narrowband recording method and a wideband recording method in, for example, a video tape recorder (hereinafter referred to as VTR). Regarding.
VTRにおいては、輝度信号や音声信号はFM
信号として記録されている。従来は、このFM信
号の搬送波は低域に設定されていたが、近年、こ
の搬送波を高域に設定することにより、記録周波
数帯域の拡大を図るハイバンド記録方式が提案さ
れている。
In VTRs, brightness signals and audio signals are FM
recorded as a signal. Conventionally, the carrier wave of this FM signal was set to a low frequency band, but in recent years, a high band recording method has been proposed in which the carrier wave is set to a high frequency band to expand the recording frequency band.
上記ハイバンド記録方式（以下、広帯域記録方
式と称する）と現行記録方式（以下、狭帯域記録
方式と称する）とではテープ送り速度が等しい。
したがつて、両者を識別するのに、テープ送り速
度が異なるテープを識別する場合のような、コン
トロール信号の周波数の違いを利用することがで
きない。
The tape feeding speed is the same between the high band recording method (hereinafter referred to as wideband recording method) and the current recording method (hereinafter referred to as narrowband recording method).
Therefore, in order to distinguish between the two, it is not possible to utilize the difference in frequency of the control signal, as is the case when identifying tapes with different tape feeding speeds.
このため、カセツトの構造などといつた機構系
の改良を図ることが考えられる。しかし、この場
合は、改造規模が著しく増大する可能性が大き
く、しかも、同一テープで両方式の記録、再生を
可能とすることも考えられるので、このような機
構系の改良も採用できない。 Therefore, it is conceivable to improve the mechanical system such as the structure of the cassette. However, in this case, there is a high possibility that the scale of the modification will increase significantly, and furthermore, it is possible that both types of recording and playback may be possible with the same tape, so such mechanical improvements cannot be adopted.
この発明は上記の事情に対処すべくなされたも
ので、電気的な構成によつて、VTRに見られる
ような広帯域記録方式と挟帯域記録方式の２つの
方式を自動的に検出することが可能な記録方式識
別回路を提供することを目的とする。
This invention was made in order to address the above-mentioned circumstances, and by using an electrical configuration, it is possible to automatically detect two methods: wideband recording method and narrowband recording method as seen in VTRs. The purpose of the present invention is to provide a recording method identification circuit.
この発明は、各記録方式におけるFM信号の搬
送波周波数の違いを利用して記録方式を識別する
ように構成したものである。
The present invention is configured to identify the recording method by utilizing the difference in the carrier wave frequency of the FM signal in each recording method.
以下、図面を参照してこの発明の実施例を詳細
に説明する。
Embodiments of the present invention will be described in detail below with reference to the drawings.
第１図はこの発明の一実施例の構成を示す回路
図で、端子１１に印加された再生Ｆ輝度信号の搬
送波は位相比較回路１２，１３に入力される。位
相比較回路１２は入力信号を狭帯域記録方式の輝
度信号の搬送波と位相比較する。一方、位相比較
回路１３は入力信号を広帯域記録方式の輝度信号
の搬送波と位相比較する。そして、角位相比較出
力はそれぞれ位相検波回路１４，１５で位相検波
される。これら２つの検波出力は検出回路１６に
入力され、同期発振している検波出力が検出され
る。もし、再生輝度信号が狭帯域記録方式のもの
であれば、位相検波回路１４の検波出力が同期発
振していることになる。同様に、広帯域記録方式
のものであれば、位相検波回路１５の検波出力が
同期発振していることになる。検出回路１６は上
記２つの検波出力のうち、どちらが同期発振して
いるかにより、記録方式を識別する。 FIG. 1 is a circuit diagram showing the configuration of an embodiment of the present invention, in which the carrier wave of the reproduced F luminance signal applied to a terminal 11 is input to phase comparator circuits 12 and 13. The phase comparison circuit 12 compares the phase of the input signal with the carrier wave of the luminance signal of the narrowband recording method. On the other hand, the phase comparator circuit 13 compares the phase of the input signal with the carrier wave of the luminance signal of the broadband recording method. Then, the angular phase comparison outputs are phase detected by phase detection circuits 14 and 15, respectively. These two detection outputs are input to the detection circuit 16, and the detection output synchronously oscillating is detected. If the reproduced luminance signal is of the narrowband recording method, the detected output of the phase detection circuit 14 is oscillating synchronously. Similarly, in the case of a wideband recording method, the detection output of the phase detection circuit 15 is oscillated synchronously. The detection circuit 16 identifies the recording method based on which of the two detected outputs is oscillating synchronously.
第２図はこの発明の第２の実施例の構成を示す
回路図である。端子２１に印加された再生FM信
号はバンドパスフイルタ２２，２３に入力され
る。バンドパスフイルタ２２は狭帯域記録方式の
FM輝度信号の周波数帯域と同じ通過帯域を有す
る。同様に、バンドパスフイルタ２３は広帯域記
録方式のFM輝度信号の周波数帯域と同じ通過帯
域を有する。バンドパスフイルタ２２，２３の出
力はそれぞれレベル判定回路２４，２５でレベル
判定される。記録方式が狭帯域記録方式のときは
レベル判定回路２４の判定結果がレベル判定回路
２５の判定結果より大きく、広帯域記録方式のと
きは、逆に、レベル判定回路２５の判定結果が大
きくなる。比較回路２６は２つの判定結果の大小
を比較し、記録方式を識別する。 FIG. 2 is a circuit diagram showing the configuration of a second embodiment of the invention. The reproduced FM signal applied to the terminal 21 is input to band pass filters 22 and 23. The bandpass filter 22 is a narrowband recording method.
It has the same passband as the frequency band of the FM luminance signal. Similarly, the bandpass filter 23 has the same passband as the frequency band of the FM luminance signal of the wideband recording method. The outputs of the bandpass filters 22 and 23 are level judged by level judgment circuits 24 and 25, respectively. When the recording method is a narrowband recording method, the determination result of the level determination circuit 24 is larger than the determination result of the level determination circuit 25, and on the contrary, when the recording method is a wideband recording method, the determination result of the level determination circuit 25 is larger. The comparison circuit 26 compares the magnitude of the two determination results and identifies the recording method.
以上の説明では、狭帯域記録方式と広帯域記録
方式に合わせて２系統の回路を設ける場合を説明
したが、回路を１系統にしてもよいことは勿論で
ある。 In the above description, a case has been described in which two circuits are provided for the narrowband recording method and the wideband recording method, but it goes without saying that the number of circuits may be one system.
第３図は第１図において、回路を１系統にした
ものである。位相比較回路３１は、例えば狭帯域
記録方式のFM輝度信号の搬送波を基準の信号と
して入力信号との位相比較を行う。この比較結果
は位相検波回路３２で位相検波される。検出回路
３３は位相検波回路３２の検波出力が同期発振し
ていれば、所定の信号を端子３４に出力し、同期
発振していなければ所定の信号を端子３５に出力
する。したがつて、端子３４，３５のどちらに所
定の信号が得られるかによつて記録方式の判別が
可能となる。 FIG. 3 shows one system of circuits in FIG. 1. The phase comparison circuit 31 performs phase comparison with an input signal using, for example, a carrier wave of an FM luminance signal of a narrowband recording method as a reference signal. This comparison result is phase detected by the phase detection circuit 32. The detection circuit 33 outputs a predetermined signal to a terminal 34 if the detected output of the phase detection circuit 32 is synchronously oscillating, and outputs a predetermined signal to a terminal 35 if it is not synchronously oscillating. Therefore, the recording method can be determined depending on which of the terminals 34 and 35 receives a predetermined signal.
第４図は第２図を展用したもので、バンドパス
フイルタ４１は例えば狭帯域記録方式のFM輝度
信号の周波数帯域を同じ通過帯域をもつ。したが
つて、記録方式が狭帯域記録方式であれば、レベ
ル検出回路４２の検出出力が大きくなり、広帯域
記録方式であれば、小さくなる。比較回路４３は
レベル判定回路４２の判定レベルを基準レベルＲ
と比較し、判定レベルが基準レベルＲを越えてい
れば、狭帯域記録方式と判定し、検出出力が基準
レベルより小さければ広帯域記録方式と判定す
る。 FIG. 4 is an extension of FIG. 2, and the bandpass filter 41 has the same passband as the frequency band of the FM luminance signal of the narrowband recording method, for example. Therefore, if the recording method is a narrowband recording method, the detection output of the level detection circuit 42 will be large, and if the recording method is a wideband recording method, it will be small. A comparison circuit 43 sets the judgment level of the level judgment circuit 42 to a reference level R.
If the determination level exceeds the reference level R, it is determined that the narrowband recording method is used, and if the detection output is smaller than the reference level, it is determined that the wideband recording method is used.
なお、第３図において、位相比較用の信号とし
ては、広帯域記録方式のFM輝度信号の搬送波を
使つてもよいことは勿論である。同様に、第４図
において、バンドパスフイルタ４１の通過帯域を
広帯域記録方式のFM輝度信号の周波数帯域に設
定してもよいことは勿論である。 In FIG. 3, it goes without saying that the carrier wave of the FM luminance signal of the broadband recording system may be used as the signal for phase comparison. Similarly, in FIG. 4, it goes without saying that the passband of the bandpass filter 41 may be set to the frequency band of the FM luminance signal of the wideband recording method.
第５図はFM信号の復調出力の直流レベルがそ
の搬送波周波数に応じて異なることを利用して記
録方式を識別するように構成された実施例を示す
ものである。すなわち、端子５１に印加された再
生FM信号は復調回路５２で復調される。この復
調出力の直流成分はロウパスフイルタ５３にて抽
出される。この直流成分は比較回路５４に入力さ
れ、そのレベルが狭帯域記録方式の直流レベル
R1や広帯域記録方式の直流レベルR2と比較され
る。これにより、ロウパスフイルタ５３から出力
される直流成分のレベルが直流レベルR1と等し
ければ狭帯域記録方式と判定され、直流レベル
R2と等しければ広帯域記録方式と判定される。 FIG. 5 shows an embodiment configured to identify the recording method by utilizing the fact that the DC level of the demodulated output of the FM signal differs depending on its carrier frequency. That is, the reproduced FM signal applied to the terminal 51 is demodulated by the demodulation circuit 52. The DC component of this demodulated output is extracted by a low-pass filter 53. This DC component is input to the comparator circuit 54, and its level is the DC level of the narrow band recording method.
It is compared with R 1 and the DC level R 2 of broadband recording method. As a result, if the level of the DC component output from the low-pass filter 53 is equal to the DC level R1 , it is determined that the narrowband recording method is used, and the DC level
If it is equal to R 2 , it is determined that the broadband recording method is used.
なお、この場合も、レベル比較用の直流レベル
を１つにし、この直流レベルとロウパスフイルタ
５３の出力レベルの大小を比較することによつて
記録方式を判別するようにしてもよい。 In this case as well, the recording method may be determined by using one DC level for level comparison and comparing this DC level with the output level of the low-pass filter 53.
このようにこの発明によれば、FM信号の搬送
周波数の違いを利用して記録方式を判別するよう
にしたので、VTR等における記録方式の違いを
簡単な構成により識別することが可能である。
As described above, according to the present invention, since the recording method is determined using the difference in the carrier frequency of the FM signal, it is possible to identify the difference in the recording method in a VTR or the like with a simple configuration.
第１図〜第５図はそれぞれこの発明の異なる実
施例を示す回路図である。
１１，２１，３４，３５，５１……端子、１
２，１３，３１……位相比較回路、１４，１５，
３２……位相検波回路、１６，３３……検出回
路、２２，２３……バンドパスフイルタ、２４，
２５，４２……レベル判定回路、２６，４３，５
４……比較回路、５２……復調回路、５３……ロ
ウパスフイルタ。
1 to 5 are circuit diagrams showing different embodiments of the present invention. 11, 21, 34, 35, 51...Terminal, 1
2, 13, 31... phase comparison circuit, 14, 15,
32... Phase detection circuit, 16, 33... Detection circuit, 22, 23... Band pass filter, 24,
25, 42...Level judgment circuit, 26, 43, 5
4... Comparison circuit, 52... Demodulation circuit, 53... Low pass filter.
Claims (1)
方式の信号を再生する磁気記録再生装置におい
て、 上記FM信号の搬送波周波数の違いを利用して
上記記録方式を識別するように構成されたことを
特徴とする記録方式識別回路。[Scope of Claims] 1. A magnetic recording and reproducing device that reproduces signals of a plurality of recording systems having different carrier wave frequencies of FM signals, configured to identify the recording system using the difference in the carrier wave frequencies of the FM signals. A recording method identification circuit characterized in that:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26014984A JPS61137278A (en) | 1984-12-10 | 1984-12-10 | Discriminating circuit of recording system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26014984A JPS61137278A (en) | 1984-12-10 | 1984-12-10 | Discriminating circuit of recording system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61137278A JPS61137278A (en) | 1986-06-24 |
| JPH0548552B2 true JPH0548552B2 (en) | 1993-07-21 |
Family
ID=17343987
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP26014984A Granted JPS61137278A (en) | 1984-12-10 | 1984-12-10 | Discriminating circuit of recording system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61137278A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61260462A (en) * | 1985-05-14 | 1986-11-18 | Akai Electric Co Ltd | Automatic frequency discriminating device for fm carrier in video tape recorder |
| JPH0725900Y2 (en) * | 1986-12-11 | 1995-06-07 | シャープ株式会社 | Recording system discrimination circuit |
| JPH0725842Y2 (en) * | 1988-10-18 | 1995-06-07 | シャープ株式会社 | Audio carrier recording judgment device in video tape recorder |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS50104910A (en) * | 1974-01-23 | 1975-08-19 | ||
| JPS60202567A (en) * | 1984-03-26 | 1985-10-14 | Mitsubishi Electric Corp | Demodulation circuit |
-
1984
- 1984-12-10 JP JP26014984A patent/JPS61137278A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61137278A (en) | 1986-06-24 |
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