JPS6352362U

JPS6352362U -

Info

Publication number: JPS6352362U
Application number: JP14503286U
Authority: JP
Priority date: 1986-09-24
Filing date: 1986-09-24
Publication date: 1988-04-08

Description

[Brief explanation of the drawing]

第１図はこの考案のオートトラツキング装置の
ブロツク図、第２図および第３図はバイモルフヘ
ツド動作点引きもどし回路の実施例のブロツク図
、第４図〜第６図は本考案を説明するためのテー
プ記録パターン及びバイモルフヘツド走査軌跡と
、基準垂直同期信号、再生垂直同期信号の位相関
係を示す図、第７図はバイモルフヘツド動作点引
きもどし回路の実施例を示す回路図、第８図は第
７図の動作を説明するためのタイミングチヤート
である。１：トラツキングエラー検出回路、２：デイザ
信号発生回路、３：加算器、４：バイモルフ、５
：再生ヘツド、６：センサ、７：バイモルフヘツ
ド動作点引きもどし回路、８：位相比較器、９：
基準垂直同期信号、１０：再生垂直同期信号、１
１：駆動アンプ回路、１２：トラツク方向検出回
路、２１：テープ、２２：ホームトラツク、２３
：記録トラツク、２４：バイモルフヘツド再生走
査軌跡、２５，２６：ワンシヨツトマルチバイブ
レータ、２７：基準同期信号のパルス幅と１トラ
ツク分未満の時間との和の時間、２８：基準同期
信号（パルス幅…基準同期信号よりも短い周期）
、２９：ワンシヨツト出力後の基準同期信号のパ
ルス幅（基準同期信号の周期―１トラツク―α）
。 Fig. 1 is a block diagram of an auto-tracking device of this invention, Figs. 2 and 3 are block diagrams of an embodiment of a bimorph head operating point pullback circuit, and Figs. 4 to 6 explain the invention. Fig. 7 is a circuit diagram showing an embodiment of the bimorph head operating point pullback circuit; is a timing chart for explaining the operation of FIG. 1: Tracking error detection circuit, 2: Dither signal generation circuit, 3: Adder, 4: Bimorph, 5
: Reproduction head, 6: Sensor, 7: Bimorph head operating point pullback circuit, 8: Phase comparator, 9:
Reference vertical synchronization signal, 10: Reproduction vertical synchronization signal, 1
1: Drive amplifier circuit, 12: Track direction detection circuit, 21: Tape, 22: Home track, 23
: recording track, 24: bimorph head reproduction scanning trajectory, 25, 26: one-shot multivibrator, 27: sum of the pulse width of the reference synchronization signal and the time less than one track, 28: reference synchronization signal (pulse width …Shorter period than the reference synchronization signal)
, 29: Pulse width of reference synchronization signal after one shot output (period of reference synchronization signal - 1 track - α)
.

Claims

[Scope of utility model registration request]

A helical scan VTR extracts a reproduction RF signal and a displacement signal of the magnetic head from the magnetic head and sensor mounted on the bimorph, detects a tracking error voltage from both signals, adds a dither signal, and supplies the signal to the bimorph. In an auto-tracking device, when reproducing at the same speed as recording, the phases of the reference vertical sync signal and the reproduced vertical sync signal are compared, and a signal corresponding to the lead or lag in the phase of the reproduced vertical sync signal with respect to the reference vertical sync signal. An auto-tracking device comprising: a circuit that generates a voltage and controls the tracking error voltage based on this signal, so that the phase of a reproduced vertical synchronization signal matches the phase of a reference vertical synchronization signal.