JPS6118242B2 - - Google Patents
Info
- Publication number
- JPS6118242B2 JPS6118242B2 JP52049875A JP4987577A JPS6118242B2 JP S6118242 B2 JPS6118242 B2 JP S6118242B2 JP 52049875 A JP52049875 A JP 52049875A JP 4987577 A JP4987577 A JP 4987577A JP S6118242 B2 JPS6118242 B2 JP S6118242B2
- Authority
- JP
- Japan
- Prior art keywords
- output
- circuit
- signal
- magnetic recording
- magnetic
- 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
Links
- 238000000034 method Methods 0.000 claims description 10
- 238000001228 spectrum Methods 0.000 claims description 9
- 238000006243 chemical reaction Methods 0.000 claims description 5
- 239000000284 extract Substances 0.000 claims 1
- 238000010586 diagram Methods 0.000 description 4
- 230000003595 spectral effect Effects 0.000 description 4
- 239000004065 semiconductor Substances 0.000 description 1
Landscapes
- Television Signal Processing For Recording (AREA)
- Signal Processing Not Specific To The Method Of Recording And Reproducing (AREA)
Description
【発明の詳細な説明】
本発明は磁気録画装置に関し、特にウオルシユ
アダマール変換回路により広帯域ビデオ信号を複
数の狭帯域信号に分割して記録する磁気録画装置
に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic recording device, and more particularly to a magnetic recording device that divides a wideband video signal into a plurality of narrowband signals and records them using a Walsh-Hadamard conversion circuit.
ビデオ信号は一般に4MHz以上の高帯域をもつ
ているので、これを磁気媒体に記録するためには
磁気媒体上での記録周波数を何等かの方法で低減
させる必要があり、この為に現在一般に用いられ
ている方式はヘリカルスキヤンヘツドを用いる方
式である。この方式はヘツドが機械的に回転する
ことに起因する各種問題を有し、又録画装置をあ
る程度以上小型化することは原理的に不可能であ
る。従つて本出願人は、固定ヘツドでのビデオ信
号の記録が可能な方式として、特願昭49−96301
号を提案した。この方式はビデオ信号をウオルシ
ユ・アダマール変換回路により複数チヤネルに分
割し、分割された各チヤネルを複数のトラツクに
記録するもので、分割されたチヤネルの帯域は、
もとのビデオ信号の帯域（分割次数分の１）の狭
帯域であることから、固定ヘツドにより十分に記
録することが出来る。 Video signals generally have a high frequency band of 4 MHz or more, so in order to record them on magnetic media, it is necessary to reduce the recording frequency on the magnetic media by some method. The proposed method uses a helical scanning head. This system has various problems due to the mechanical rotation of the head, and it is theoretically impossible to downsize the recording device beyond a certain degree. Therefore, the present applicant has proposed a method for recording video signals with a fixed head in Japanese Patent Application No. 49-96301.
I suggested the issue. In this method, a video signal is divided into multiple channels using a Walsh-Hadamard transform circuit, and each divided channel is recorded on multiple tracks.The bandwidth of the divided channels is
Since the band is narrower than the band of the original video signal (one division order), it can be sufficiently recorded by a fixed head.
本発明はウオルシユ・アダマール変換回路を利
用した上記の磁気録画方式を更に改良するもの
で、その目的は記録トラツクの数を分割チヤネル
数に比べて大幅に減少させることにある。本発明
の特徴は、分割された各チヤネルのスペクトルの
性質に着目して、分割されたチヤネルを、帯域を
増やさずに、周波数インターリーブ方式により多
重化し、もつてチヤネル数（つまり記録トラツク
の数）を減少させることにある。 The present invention further improves the above magnetic recording system using the Walsh-Hadamard transform circuit, and its purpose is to significantly reduce the number of recording tracks compared to the number of divided channels. A feature of the present invention is that by focusing on the spectral properties of each divided channel, the divided channels are multiplexed by a frequency interleaving method without increasing the band, thereby reducing the number of channels (that is, the number of recording tracks). The goal is to reduce
周波数インターリーブ方式は、ビデオ信号が本
質的に有している性質、つまり、水平同期周波数
（通常15.75kHz）の整数倍のスペクトル成分が大
きく、その中間の周波数（水平同期周波数の半整
数倍）のスペクトル成分が小さいという性質を利
用して、単一の帯域内に２以上の信号を多重化す
る技術である。 The frequency interleaving method is based on the inherent characteristics of video signals, that is, the spectral components at integral multiples of the horizontal synchronization frequency (usually 15.75kHz) are large, and the frequencies in between (half-integer multiples of the horizontal synchronization frequency) are large. This is a technique that multiplexes two or more signals within a single band by utilizing the property that spectral components are small.
第１図は本発明の原理を説明するスペクトル図
で、CH ａ及びCH ｂは２つの分割されたチヤネ
ルのスペクトルで水平同期周波数の整数倍の周波
数（ｎ、ｎ＋１、ｎ＋２、……）で大きなスペク
トルをもち、その中間の周波数の成分は小さい。
第１図のCH a′及びCH b′は上記各スペクトルを
くし形フイルタにより、水平同期周波数の半整数
倍の成分を除去した波形である。同図CH b″は
CH b′を、水平同期周波数の半整数倍の周波数で
変調したもので、変調されたスペクトルは両者の
和及び差の周波数成分をもつことから、CH
b″のスペクトルは図示ごとく、水平同期周波数
の半整数倍で成分をもち、整数倍で成分をもたな
い。従つてCH a′とCH b″を単純に加算して多重
化し、CH（a′＋b″）のごときスペクトルが得ら
れ、これを固定ヘツドにより記録媒体のトラツク
に記録する。当然、各トラツクは２チヤネルを多
重化して記録するわけで、トラツクの数はチヤネ
ルの数の1/2となる。 Figure 1 is a spectrum diagram explaining the principle of the present invention, CH a and CH b are the spectrum of two divided channels, and have large frequencies at frequencies that are integral multiples of the horizontal synchronization frequency (n, n+1, n+2,...). It has a spectrum, and the intermediate frequency components are small.
CH a' and CH b' in FIG. 1 are waveforms obtained by removing components of half-integer multiples of the horizontal synchronization frequency from each of the above spectra using a comb filter. CH b″ in the same figure is
CH b′ is modulated at a frequency that is a half-integer multiple of the horizontal synchronization frequency, and the modulated spectrum has frequency components that are the sum and difference of both, so CH
As shown in the figure, the spectrum of CH(a '+b'') is obtained, and this is recorded on the track of the recording medium using a fixed head.Of course, each track is recorded by multiplexing two channels, so the number of tracks is 1/1 of the number of channels. It becomes 2.
再生系においては、各トラツクからの読み出し
出力を、くし形フイルタにより、水平同期周波数
の整数倍の成分と半整数倍の成分に分離し、次に
変調波を復調して、分割チヤネルを復元し、これ
からウオルシユ・アダマール逆変換回路を介して
ビデオ信号を得る。 In the reproduction system, the read output from each track is separated into components that are integral multiples of the horizontal synchronization frequency and components that are half integral multiples of the horizontal synchronization frequency, and then the modulated wave is demodulated to restore the divided channels. , from which a video signal is obtained via a Walsh-Hadamard inverse transform circuit.
第２図は上記方式にもとずく磁気録画再生装置
のブロツクダイヤグラムである。入力ビデオ信号
はくし形フイルタF1により水平同期周波数の半
整数倍のスペクトル成分を除去し、これを８次の
ウオルシユ・アダマール変換回路Ｈにより８チヤ
ネルに分割する。もちろん一般に分割の次数は任
意で、本発明は８チヤネルのみに限定されるもの
ではない。分割されたチヤネルのうち、チヤネル
５，６，７及び８は極性反転器INVにより、端子
C1に印加される制御信号により水平同期信号毎
に極性を反転する。このことは水平同期周波数の
1/2の周波数で変調することに相当する。極性反
転器の出力（5′、6′、7′、8′）は各々分割チヤネ
ル（CH４，３，２，１）と加算されて多重化さ
れ、４個の記録ヘツドＷにより磁気記録媒体Ｔに
記録される。従つて必要なトラツク数はチヤネル
数の1/2に減少する。 FIG. 2 is a block diagram of a magnetic recording and reproducing apparatus based on the above system. The input video signal is filtered by a comb filter F1 to remove spectral components having a half-integer multiple of the horizontal synchronization frequency, and is divided into eight channels by an eighth-order Walsh-Hadamard transform circuit H. Of course, the degree of division is generally arbitrary, and the present invention is not limited to only 8 channels. Among the divided channels, channels 5, 6, 7 and 8 are connected to terminals by polarity inverter INV.
The control signal applied to C1 inverts the polarity for each horizontal synchronization signal. This means that the horizontal synchronization frequency
This corresponds to modulating at 1/2 the frequency. The outputs (5', 6', 7', 8') of the polarity inverters are each added to the divided channels (CH4, 3, 2, 1) and multiplexed, and the four recording heads W output the magnetic recording medium T. recorded in The number of required tracks is therefore reduced to 1/2 of the number of channels.
このように記録されたビデオ信号を再生するに
は、読み取りヘツドＲにより各トラツクを読み出
し、くし形フイルタF2に印加する。なお図示の
簡単の為にヘツドＷとＲは別に描かれているが、
もちろん同一のヘツドを記録と再生の両方に切替
使用することは可能である。くし形フイルタF2
は、水平同期周波数の整数倍の出力(a)と、半整数
倍の出力(b)とを有し、各チヤネルの出力(b)は極性
反転器INVに印加され、端子C2に印加される水平
同期信号毎の制御信号により極性を反転される。
極性反転器INVの出力（５、６、７、８）は、く
し形フイルタF2の出力(a)と共にウオルツシユ・
アダマール逆変換回路H-1に印加され、その出力
に再生ビデオ出力ＶOUTを得る。 To reproduce the video signal recorded in this way, each track is read out by the reading head R and applied to the comb filter F2 . Note that heads W and R are drawn separately for ease of illustration, but
Of course, it is possible to switch and use the same head for both recording and reproduction. Comb filter F 2
has an output (a) that is an integer multiple of the horizontal sync frequency and an output (b) that is a half integer multiple of the horizontal sync frequency, and the output (b) of each channel is applied to the polarity inverter INV and is applied to the terminal C 2 . The polarity is inverted by the control signal for each horizontal synchronization signal.
The outputs (5, 6, 7, 8) of the polarity inverter INV, together with the output (a) of the comb filter F2, are output from the waltz filter.
It is applied to the Hadamard inverse transform circuit H -1 , and the reproduced video output V OUT is obtained at its output.
第３図はくし形フイルタF2の構成例で、デイ
レイ回路Ｄ（遅延時間１／１５．７５ｋＨｚ＝0.063492
ｍ
Ｓ）と加算回路及び減算回路により、図示のごと
く簡単に構成出来る。デイレイ回路Ｄには例えば
BBD、CCDのごとき半導体の利用が可能であ
る。 Figure 3 shows an example of the configuration of a comb filter F2 , with a delay circuit D (delay time 1/15.75kHz = 0.063492
mS), an addition circuit, and a subtraction circuit, it can be easily configured as shown in the figure. For example, delay circuit D has
Semiconductors such as BBD and CCD can be used.
以上、実施例により詳しく説明したごとく、ウ
オルシユ・アダマール変換によるビデオ記録方式
に、周波数インターリーブ方式を併用することに
より、記録に必要なトラツク数を大幅に減少させ
ることが出来る。 As described above in detail in the embodiments, by using the frequency interleaving method in combination with the video recording method using the Walsh-Hadamard transform, the number of tracks required for recording can be significantly reduced.
第１図は本発明による周波数インターリーブの
スペクトル説明図、第２図は本発明による磁気録
画再生装置のブロツクダイヤグラム、第３図は、
第２図におけるくし形フイルタF2の構成例であ
る。
ＶIN；入力ビデオ信号、ＶOUT；出力ビデオ信
号、F1，F2；くし形フイルタ、Ｈ；ウオルシ
ユ・アダマール変換回路、H-1；ウオルシユ・ア
ダマール逆変換回路、INV；極性反転器、Ｔ；磁
気記録媒体、Ｗ；記録ヘツド、Ｒ；再生ヘツド。
FIG. 1 is a spectrum explanatory diagram of frequency interleaving according to the present invention, FIG. 2 is a block diagram of a magnetic recording and reproducing apparatus according to the present invention, and FIG.
This is an example of the configuration of the comb filter F2 in FIG. 2. V IN ; input video signal, V OUT ; output video signal, F 1 , F 2 ; comb filter, H; Walsh-Hadamard conversion circuit, H -1 ; Walsh-Hadamard inverse conversion circuit, INV; polarity inverter, T ; magnetic recording medium; W; recording head; R; reproducing head.
Claims (1)
間隔でとり出すくし形フイルタと、該フイルタの
出力を複数チヤネルに分割するウオルシユ・アダ
マール変換回路と、該変換回路の特定のチヤネル
の出力信号を水平同期信号の1/2の周波数で変調
する変調回路と、該変調回路の出力を前記変換回
路の別のチヤネルの出力信号と加算する加算回路
と、該加算回路の出力を磁気媒体に記録する磁気
ヘツドとを有することを特徴とする磁気録画装
置。 ２ 前記変調回路が、水平同期信号の周期毎に信
号の極性を反転させる極性反転器である特許請求
の範囲第１項に記載の磁気録画装置。 ３ ウオルシユ・アダマール変換方式により記録
されたビデオ信号を磁気媒体から読み出す複数の
磁気ヘツドと、各磁気ヘツドの出力に接続され、
水平同期信号の周期の整数倍及び半整数倍のスペ
クトルをとり出す第１出力及び第２出力を有する
第２のくし形フイルタと、前記各第２出力を水平
同期信号の1/2の周波数で復調する復調回路と、
前記第１出力と該復調回路の出力とを入力として
ビデオ出力を発生するウオルシユ・アダマール逆
変換回路とを有することを特徴とする磁気録画再
生装置。 ４ 前記復調回路が、水平同期信号の周期毎に信
号の極性を反転させる極性反転器である特許請求
の範囲第３項に記載の磁気録画再生装置。 ５ 前記第２のくし形フイルタが、水平同期信号
の周期を遅延時間とする遅延回路と、該遅延回路
の出力と入力信号との和及び差をとる加算回路及
び減算回路とを有する特許請求の範囲第３項に記
載の磁気録画再生装置。[Claims] 1. A comb filter that extracts the spectrum of a video signal at intervals of a horizontal synchronization frequency, a Walsh-Hadamard transform circuit that divides the output of the filter into a plurality of channels, and a a modulation circuit that modulates the output signal at half the frequency of the horizontal synchronization signal; an addition circuit that adds the output of the modulation circuit to the output signal of another channel of the conversion circuit; 1. A magnetic recording device comprising: a magnetic head for recording data on a magnetic recording device; 2. The magnetic recording device according to claim 1, wherein the modulation circuit is a polarity inverter that inverts the polarity of the signal every cycle of the horizontal synchronization signal. 3 A plurality of magnetic heads for reading out video signals recorded by the Walsh-Hadamard transform method from a magnetic medium, and a plurality of magnetic heads connected to the output of each magnetic head,
a second comb filter having a first output and a second output for extracting a spectrum having an integer multiple and a half integer multiple of the period of the horizontal synchronizing signal; a demodulation circuit that demodulates;
A magnetic recording and reproducing apparatus comprising: a Walsh-Hadamard inverse conversion circuit that receives the first output and the output of the demodulation circuit and generates a video output. 4. The magnetic recording and reproducing apparatus according to claim 3, wherein the demodulation circuit is a polarity inverter that inverts the polarity of the signal every period of the horizontal synchronization signal. 5. The second comb filter includes a delay circuit whose delay time is the period of the horizontal synchronizing signal, and an addition circuit and a subtraction circuit that take the sum and difference between the output of the delay circuit and the input signal. The magnetic recording and reproducing device according to scope 3.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4987577A JPS53135612A (en) | 1977-05-02 | 1977-05-02 | Magnetic picture recorder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4987577A JPS53135612A (en) | 1977-05-02 | 1977-05-02 | Magnetic picture recorder |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS53135612A JPS53135612A (en) | 1978-11-27 |
| JPS6118242B2 true JPS6118242B2 (en) | 1986-05-12 |
Family
ID=12843210
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4987577A Granted JPS53135612A (en) | 1977-05-02 | 1977-05-02 | Magnetic picture recorder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS53135612A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6128248Y2 (en) * | 1979-04-26 | 1986-08-22 |
-
1977
- 1977-05-02 JP JP4987577A patent/JPS53135612A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS53135612A (en) | 1978-11-27 |
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