JPS6242333B2 - - Google Patents
Info
- Publication number
- JPS6242333B2 JPS6242333B2 JP55043962A JP4396280A JPS6242333B2 JP S6242333 B2 JPS6242333 B2 JP S6242333B2 JP 55043962 A JP55043962 A JP 55043962A JP 4396280 A JP4396280 A JP 4396280A JP S6242333 B2 JPS6242333 B2 JP S6242333B2
- Authority
- JP
- Japan
- Prior art keywords
- electro
- mechanical
- transducer
- video
- mechanical transducer
- 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
- 238000006243 chemical reaction Methods 0.000 claims description 4
- 238000010586 diagram Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 5
- 239000003990 capacitor Substances 0.000 description 3
- 238000010248 power generation Methods 0.000 description 3
- 230000007423 decrease Effects 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 2
- 238000013016 damping Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
- G11B5/58—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
- G11B5/584—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for track following on tapes
- G11B5/588—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for track following on tapes by controlling the position of the rotating heads
- G11B5/592—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for track following on tapes by controlling the position of the rotating heads using bimorph elements supporting the heads
Landscapes
- Adjustment Of The Magnetic Head Position Track Following On Tapes (AREA)
Description
【発明の詳細な説明】
本発明は、バイモルフ形圧電素子などの電気−
機械変換素子の駆動装置に関するもので、特に、
ビデオ用回転磁気ヘツドの磁気テープに対する走
査位置を変位させるタイプのビデオテープレコー
ダ等に使用して有効なものである。DETAILED DESCRIPTION OF THE INVENTION The present invention provides electrical
It relates to a drive device for a mechanical transducer, in particular,
It is effective for use in a video tape recorder or the like in which the scanning position of a rotating magnetic head for video with respect to a magnetic tape is displaced.
近年、ビデオテープレコーダ（以下、VTRと
称す）などの磁気テープを用いた映像信号磁気記
録再生装置または映像信号磁気再生装置におい
て、再生時に、記録されたトラツクを正確に走査
する目的で、いわゆるオート・トラツキング装置
が導入され始めた。このオート・トラツキング装
置は、記録時のテープ走行速度と異なつた走行速
度で再生するスロー再生、スチル再生、フアース
ト再生および逆転再生などの特殊モード再生にお
いて、ノイズバンドのない再生画像を提供するこ
とが可能である。このようなオート・トラツキン
グ装置は通常、映像信号再生用ビデオヘツドを圧
電素子の一端に取付け、磁気テープ上のビデオト
ラツクに対応した電圧振幅波形を上記圧電素子に
供給することにより、上記ビデオトラツクをトレ
ースするようにしたものである。しかし、上記圧
電素子に上記電圧振幅波形を印加すると、上記圧
電素子の機械的共振周波数を持つた機械振動（い
わゆるリンギング）が生じ、上述したトレースが
困難になるという問題があつた。 In recent years, in video signal magnetic recording and reproducing devices or video signal magnetic reproducing devices using magnetic tape such as video tape recorders (hereinafter referred to as VTRs), so-called automatic・Tracking devices have begun to be introduced. This auto-tracking device is capable of providing reproduced images without noise bands in special modes such as slow playback, still playback, fast playback, and reverse playback in which the tape is played back at a running speed different from the tape running speed at the time of recording. It is possible. Such auto-tracking devices usually attach a video head for reproducing video signals to one end of a piezoelectric element, and supply the piezoelectric element with a voltage amplitude waveform corresponding to the video track on the magnetic tape, thereby playing the video track. It is designed to be traced. However, when the voltage amplitude waveform is applied to the piezoelectric element, mechanical vibration (so-called ringing) occurs due to the mechanical resonance frequency of the piezoelectric element, making the above-mentioned tracing difficult.
従来、そのような問題を解決するために、上記
圧電素子と共に変位する別の発電用圧電素子を設
け、この発電用圧電素子の出力電圧波形を上記電
圧振幅波形に帰還することにより、上記リンギン
グのダンピングを行なうという手段が提案されて
いるが、これらの従来例においては、変位を起こ
すための圧電素子以外に発電用の圧電素子が必要
であるため、構造が複雑になり、信頼性が低下す
ると共にコスト高になるという問題がある。特
に、圧電素子自体の機械的質係数ＱMは通常400〜
1000程度であるため、上記リンギングは非常に大
きなものとなるという欠点があつた。 Conventionally, in order to solve such problems, the above-mentioned ringing has been solved by providing another power generation piezoelectric element that is displaced together with the above-mentioned piezoelectric element, and feeding back the output voltage waveform of this power generation piezoelectric element to the above-mentioned voltage amplitude waveform. Methods of damping have been proposed, but these conventional examples require a piezoelectric element for power generation in addition to the piezoelectric element for causing displacement, resulting in a complex structure and reduced reliability. There is also the problem of increased costs. In particular, the mechanical quality factor Q M of the piezoelectric element itself is usually 400~
Since it is about 1000, the above-mentioned ringing has a drawback that it becomes very large.
本発明は上記圧電素子とビデオ用回転磁気ヘツ
ドを含む機械系の共振が持続しないように電流制
限を行なうことにより、前記リンギングを軽減す
るようにしたものである。以下、本発明を図示の
実施例に基いて説明する。第１図は本発明の一実
施例の要部構成図であり、１は電気−機械変換素
子であるところのバイモルフ構造の半円環形圧電
子であり、表裏の電極１ａと１ｂは共通に接続さ
れ、狭まれた内部の共通電極１Ｃは接地されてい
る。 The present invention reduces the ringing by limiting the current so that the resonance of the mechanical system including the piezoelectric element and the rotating magnetic video head does not persist. Hereinafter, the present invention will be explained based on illustrated embodiments. FIG. 1 is a diagram showing the main part of an embodiment of the present invention, in which 1 is a semicircular piezoelectric device with a bimorph structure, which is an electro-mechanical conversion element, and the front and back electrodes 1a and 1b are commonly connected. The common electrode 1C inside the narrowed area is grounded.
上記圧電素子１の両端部は支持体３に固定され
ており、自由端となる中央部にはビデオ用回転磁
気ヘツド（以下、ビデオヘツドと称す）２が取付
けられている。駆動信号発生器２０を構成する波
形発生器４の出力信号（駆動信号）は増幅器５お
よび電流制限用抵抗器６を通して上記圧電素子１
の電極１ａ，１ｂと共通電極１ｃ間に供給され
る。 Both ends of the piezoelectric element 1 are fixed to a support 3, and a video rotary magnetic head (hereinafter referred to as video head) 2 is attached to the free central part. The output signal (drive signal) of the waveform generator 4 constituting the drive signal generator 20 is transmitted to the piezoelectric element 1 through an amplifier 5 and a current limiting resistor 6.
is supplied between the electrodes 1a, 1b and the common electrode 1c.
第２図に上記圧電素子１の電気等価回路を示
す。また、第３図に上記圧電素子１単体の供給電
流−周波数特性を示す（すなわち本発明における
ごとき電流制限を行なわない場合）。第２図にお
いて、上記圧電素子１は、インダクタンスがＬの
コイル７、容量がＣのコンデンサ８、抵抗値がｒ
の抵抗９の直列回路で構成される第１回路１０
と、容量がＣpのコンデンサ１１で構成される第
２回路１２の等価並列回路で表わされる。なお、
上記第１回路１０は圧電素子１の圧電的機械振動
を表わしており、第２回路１２は圧電素子１の電
極間容量を表わしている。 FIG. 2 shows an electrical equivalent circuit of the piezoelectric element 1. Further, FIG. 3 shows the supply current-frequency characteristics of the piezoelectric element 1 alone (that is, in the case where current limitation as in the present invention is not performed). In FIG. 2, the piezoelectric element 1 includes a coil 7 with an inductance of L, a capacitor 8 with a capacitance of C, and a resistance value of r.
A first circuit 10 consisting of a series circuit of resistors 9 of
is expressed by an equivalent parallel circuit of a second circuit 12 composed of a capacitor 11 with a capacitance of C p . In addition,
The first circuit 10 represents the piezoelectric mechanical vibration of the piezoelectric element 1, and the second circuit 12 represents the interelectrode capacitance of the piezoelectric element 1.
第３図において、直列共振周波数（S）はコ
イル７およびコンデンサ８で定まり、その点にお
ける機械的質係数ＱMは次の第(1)式で定まる。 In FIG. 3, the series resonance frequency ( S ) is determined by the coil 7 and the capacitor 8, and the mechanical quality factor Q M at that point is determined by the following equation (1).
ＱM＝２πＳＬ／ｒ ………(1)
ここで、第１図に示すように、抵抗値Ｒの電流
制限用抵抗器６を挿入すると、その場合の機械的
質係数Q′Mは第(2)式に示すように実効的に低下す
る。 Q M =2π S L/r (1) Here, if a current limiting resistor 6 with a resistance value R is inserted as shown in Fig. 1, the mechanical quality factor Q' M in that case is It effectively decreases as shown in equation (2).
Q′M＝２πＳＬ／ｒ＋Ｒ ………(2)
すなわち、供給電流−周波数特性は第４図に例
示するようになる。第４図において、コーナー周
波数（C）は次の第(3)式で定まる。 Q' M =2π S L/r+R (2) That is, the supply current-frequency characteristics are as illustrated in FIG. In FIG. 4, the corner frequency ( C ) is determined by the following equation (3).
C＝１／２π・Ｃｐ・Ｒ ………(3)
機械的質係数が低下し、供給電流−周波数特性
が第４図のようになることにより、前記リンギン
グは実用上問題にならないレベルにまで低下する
という効果が得られる。なお、上記抵抗値Ｒの下
限は上記効果が生じる限度で定まる。実験によれ
ば、十分な効果が生じる下限として、第(4)式が得
られた。 C = 1/2π・C p・R ………(3) As the mechanical quality factor decreases and the supply current-frequency characteristic becomes as shown in Figure 4, the ringing becomes a level that does not pose a problem in practice. This has the effect of reducing the Note that the lower limit of the resistance value R is determined by the limit at which the above effect occurs. According to experiments, equation (4) was obtained as the lower limit at which a sufficient effect occurs.
２π・Ｃp・Ｒ＝１／Ｓ ………(4)
すなわち、２π・Ｃp・Ｒが圧電素子１とビデ
オヘツド２からなる機械系の共振周期とほぼ同一
か、あるいは長くなるように抵抗値Ｒを設定すれ
ば、十分な効果が得られる。なお、ある程度上記
リンギングが低下すればよいのであれば、下限と
しては第(5)式が実験結果として得られた。 2π・C p・R=1/ S ……(4) In other words, the resistor is set so that 2π・C p・R is approximately the same as or longer than the resonance period of the mechanical system consisting of the piezoelectric element 1 and the video head 2. By setting the value R, a sufficient effect can be obtained. Note that, as long as the ringing is reduced to a certain extent, Equation (5) was obtained as a lower limit as an experimental result.
Ｃp・Ｒ＝１／Ｓ ………(5)
上記抵抗値Ｒの上限は、上記波形発生器４の出
力信号すなわち駆動信号が持つ周波数スペクトラ
ムによつて定まる。つまり、（２π・Ｃp×Ｒ）を
上記駆動信号の基本繰返し周期よりも十分に短か
い値に設定しなければ、ビデオヘツド２の先端は
希望通りの変位を得ることはできない。なお、上
記基本繰返し周期は上記ビデオヘツド２の走査周
期と一致しており、たとえばNTSC信号用の２ヘ
ツド・ヘリカル・スキヤン型VTRにおいては約
1/30秒である。また、NTSC信号用の１ヘツド・
ヘリカル・スキヤン型VTRにおいては約1/60秒
である。 C p ·R=1/ S (5) The upper limit of the resistance value R is determined by the frequency spectrum of the output signal of the waveform generator 4, that is, the drive signal. That is, unless (2π·C p ×R) is set to a value sufficiently shorter than the basic repetition period of the drive signal, the tip of the video head 2 cannot obtain the desired displacement. Note that the basic repetition period coincides with the scanning period of the video head 2, and for example, in a two-head helical scan type VTR for NTSC signals, it is approximately
It is 1/30 second. Also, 1 head for NTSC signal.
For helical scan type VTRs, it is approximately 1/60 second.
また、圧電素子１の形状は第１図に示すような
半円環形に限定されるものではなく、そのほか、
第５図に示すような短冊形でも、あるいは第６図
に示すような円環形でも同様な効果が得られる。
なお、第５図において、圧電素子１３の一端部は
支持体１４に固定支持され、他端部の自由端には
ビデオヘツド２が取付けられている。第６図にお
いて、円環形の圧電素子１５は、その180゜分割
点を支持体１６および１７で固定支持されてお
り、上記支持体１６および１７からほぼ90゜離れ
た圧電素子上の位置にビデオヘツド２が取付けら
れている。 Furthermore, the shape of the piezoelectric element 1 is not limited to the semicircular shape shown in FIG.
Similar effects can be obtained by using a rectangular shape as shown in FIG. 5 or an annular shape as shown in FIG.
In FIG. 5, one end of the piezoelectric element 13 is fixedly supported by a support 14, and the video head 2 is attached to the other free end. In FIG. 6, an annular piezoelectric element 15 is fixedly supported at its 180° dividing point by supports 16 and 17, and a video signal is placed on the piezoelectric element at a position approximately 90° away from the supports 16 and 17. Head 2 is attached.
第１図は本発明の一実施例の要部構成図、第２
図は圧電素子の電気的等価回路図、第３図は圧電
素子単体の供給電流−周波数特性図、第４図は本
発明による供給電流−周波数特性の一例を示す
図、第５図および第６図は本発明の別の実施例の
部分構成図である。
１，１３，１５……圧電素子、２……ビデオヘ
ツド、３，１４，１６，１７……支持体、４……
波形発生器、５……増幅器、６……抵抗器、２０
……駆動信号発生器。
Fig. 1 is a main part configuration diagram of an embodiment of the present invention, Fig. 2
The figure is an electrical equivalent circuit diagram of a piezoelectric element, FIG. 3 is a supply current-frequency characteristic diagram of a single piezoelectric element, FIG. 4 is a diagram showing an example of supply current-frequency characteristic according to the present invention, and FIGS. The figure is a partial configuration diagram of another embodiment of the present invention. 1, 13, 15... Piezoelectric element, 2... Video head, 3, 14, 16, 17... Support, 4...
Waveform generator, 5...Amplifier, 6...Resistor, 20
...Drive signal generator.
Claims (1)
に抵抗値がＲの抵抗器を介して駆動信号発生器か
らの駆動信号を供給することにより、前記電気−
機械変換素子を前記駆動信号の大きさに応じて変
位させ、その電気−機械変換素子の自由端に取付
けた磁気ヘツドの先端位置を変位させる駆動手段
を具備し、かつ、（２π×Ｃp×Ｒ）を前記駆動信
号の基本繰返し周期よりも十分に短かく、前記電
気−機械変換素子と磁気ヘツドを含めてなる機械
系の共振周期とほぼ同一もしくは長く設定したこ
とを特徴とする電気−機械変換素子の駆動装置。 ２ 特許請求の範囲第１項の記載において、前記
磁気ヘツドを、ヘリカル・スキヤン型ビデオテー
プレコーダにおけるビデオ用回転磁気ヘツドと
し、前記駆動信号の基本繰返し周期を前記ビデオ
用回転磁気ヘツドの走査期間と一致させるように
したことを特徴とする電気−機械変換素子の駆動
装置。 ３ 特許請求の範囲第１項または第２項の記載に
おいて、前記電気−機械変換素子として、バイモ
ルフ形の圧電素子を使用することを特徴とする電
気−機械変換素子の駆動装置。 ４ 特許請求の範囲第１項または第２項の記載に
おいて、前記電気−機械変換素子として短冊形の
ものを使用し、その長手方向の一端を支持体に固
定する支持端とし、他端をビデオ用回転磁気ヘツ
ドを取付ける自由端とすることを特徴とする電気
−機械変換素子の駆動装置。 ５ 特許請求の範囲第１項または第２項の記載に
おいて、前記電気−機械変換素子として、ほぼ半
円環状のものを使用し、その両端を支持体に固定
する支持端とし、中央部をビデオ用回転磁気ヘツ
ドを取り付ける自由端とすることを特徴とする電
気−機械変換素子の駆動装置。 ６ 特許請求の範囲第１項または第２項の記載に
おいて、前記電気−機械変換素子として、ほぼ円
環状のものを使用し、その180゜分割点を支持体
に固定する支持端とし、上記支持端からほぼ90゜
離れた位置をビデオ用回転磁気ヘツドを取付ける
自由端とすることを特徴とする電気−機械変換素
子の駆動装置。[Claims] 1. By supplying a drive signal from a drive signal generator to an electromechanical transducer whose interelectrode capacitance is Cp through a resistor with a resistance value R,
It is provided with driving means for displacing the mechanical transducer according to the magnitude of the drive signal and for displacing the tip position of the magnetic head attached to the free end of the electro-mechanical transducer, and (2π×C p R) is set to be sufficiently shorter than the basic repetition period of the drive signal and approximately equal to or longer than the resonance period of the mechanical system including the electro-mechanical conversion element and the magnetic head. Conversion element drive device. 2. In claim 1, the magnetic head is a rotating magnetic head for video in a helical scan type video tape recorder, and the basic repetition period of the drive signal is the scanning period of the rotating magnetic head for video. 1. A driving device for an electro-mechanical conversion element, characterized in that they match. 3. An electro-mechanical transducer driving device according to claim 1 or 2, characterized in that a bimorph piezoelectric element is used as the electro-mechanical transducer. 4. In the description of claim 1 or 2, a rectangular element is used as the electro-mechanical transducer, one longitudinal end of which is a supporting end fixed to a support, and the other end is a video transducer. 1. A drive device for an electro-mechanical transducer, characterized in that the free end is provided with a rotating magnetic head for use with the device. 5. In the description of claim 1 or 2, the electro-mechanical transducer is formed into a substantially semicircular shape, with both ends serving as support ends fixed to a support, and the center portion serving as a video transducer. 1. A driving device for an electro-mechanical transducer, characterized in that the free end is provided with a rotating magnetic head. 6. In the statement of claim 1 or 2, the electro-mechanical transducer is a substantially annular element, and its 180° dividing point is the support end fixed to the support, and the electro-mechanical transducer is 1. A drive device for an electro-mechanical transducer, characterized in that a position approximately 90° away from the end is a free end to which a rotating magnetic video head is attached.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4396280A JPS56140524A (en) | 1980-04-02 | 1980-04-02 | Driving device for electromechanical transducer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4396280A JPS56140524A (en) | 1980-04-02 | 1980-04-02 | Driving device for electromechanical transducer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS56140524A JPS56140524A (en) | 1981-11-02 |
| JPS6242333B2 true JPS6242333B2 (en) | 1987-09-08 |
Family
ID=12678327
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4396280A Granted JPS56140524A (en) | 1980-04-02 | 1980-04-02 | Driving device for electromechanical transducer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS56140524A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0557989U (en) * | 1991-12-26 | 1993-07-30 | 吉弘 狩野 | Shared remote control with speaker |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60127621U (en) * | 1984-01-31 | 1985-08-27 | ソニー株式会社 | Tracking control device |
-
1980
- 1980-04-02 JP JP4396280A patent/JPS56140524A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0557989U (en) * | 1991-12-26 | 1993-07-30 | 吉弘 狩野 | Shared remote control with speaker |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS56140524A (en) | 1981-11-02 |
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