JPS5850625A - Rotary head type magnetic video recording and reproducing device - Google Patents

Abstract

PURPOSE:To permit the use of the same head for both recording and reproducing by reproducing a standard tape beforehand, storing control signals in a memory, and controlling the position of the head with the control signals read out from said memory in the stage of recording. CONSTITUTION:CTL signals 12 and video tracks 13 are recorded in correct phase relations on a standard tape 11. If a control head is reproduced in a home position, the signals 12 and the tracks 13 maintain the correct phase relations. If a switch 9 is turned off in this time, the control signal voltages for the max. outputs of the head is amplified and the control signal voltages at the respective points in accordance with sampling periods are stored in a memory 10 by a sampling hold 15. The switch 9 conducts, and the control signal voltages in accordance with the above-described sampling periods of the memory 10 are amplified and are applied to piezoelectric effect element electrodes 4, by which the normal position relations of the head positions are maintained for every head and recording is performed. In the stage of reproducing, the heads are controlled to the positions where the max. outputs are obtained without going through the block diagrams as described above, whereby reproducing is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a helical scan type magnetic recording and reproducing apparatus comprising a plurality of rotating heads.

Conventionally, a so-called auto-tracking type VTR has been known as this type of device. This device attaches a plurality of rotating magnetic heads to a rotating body via a displacement member such as a piezoelectric effect element that is displaced by the application of an electric signal, and attaches a magnetic tape at a predetermined angle to a head drum whose circumferential surface follows the rotation locus of the rotating heads. The rotary head is configured to scan the recording track well by winding the recording head and applying control No. 7 to the member during reproduction.

However, in a VTR having such a configuration, when recording, there is of course no recording track, so the rotary head must be fixed at a fixed position, and zero or constant voltage is applied to the displacement member. Since it is originally designed to be movable, it is difficult to fix it in a fixed position. For this reason, in the past, a configuration in which a fixed head for recording and a movable head for reproduction were provided separately was often adopted. Therefore, two sets of heads were required, which increased costs and made adjustment difficult.

The present invention has been made in order to eliminate the drawbacks of the conventional devices as described above, and an object of the present invention is to provide a device that uses the same movable head for both recording and reproduction and controls the movable head to a predetermined position during recording. It is an object.

An embodiment of the present invention will be described below with reference to the drawings. In Fig. 1, 1 is a rotary printer, and 2 is a rotary/printer.
A head bar is a head bar to which a piezoelectric effect element 6 having an electrode 4 is fixed to the center of the goo 1, and 5 represents a rotating head placed on the piezoelectric effect element 6. Note that 6 is the control head and 7 is the control head. Pinch roller 8 indicates a magnetic tape.

FIG. 2 is an enlarged side view of the main part of FIG. 1.

In FIG. 5, 9 is an RFC switch, 10 is a memory element for storing control signal voltages, 11 is a standard tape used as a magnetic chip 7'8, and 12 is a C of the standard tape 11.
TL signal, Ilj: represents one video track on the standard tape 11. 14 and 16 are amplifiers, 15 is a sampling hold for taking out each point obtained by dividing a certain period of the control signal voltage, and 17 is a recording track on the magnetic tape and a rotary head 5 that follows and scans the recording track. This is a terminal to which a control signal to be applied to the piezoelectric effect element based on the detected track deviation is detected as is well known and is to be applied to the piezoelectric effect element as is well known. FIG. 4 shows the voltage waveform (0° to 180°) of the control signal voltage Va during the period when the rotary head 5 rotates 180° about the axis, that is, during the period when one video trunk (1 field) on the standard tape 11 is reproduced. °).

Next, the operation of this invention will be explained. First, the process of reproducing and storing a standard tape will be explained using the block diagram shown in FIG. First, to explain the entire playback process, standard tape 11
Since the CTL signal 12 and the video track 16 are recorded in a correct phase relationship, when the standard tape 11 is played back on an auto-tracking VTR having a piezoelectric effect element 5, the control head is placed at a certain position. If so, the CTL signal 12 and video track 13 maintain a correct phase relationship. At this time, when the REC switch 9 is turned off, the head output is maximized. Control signal voltage Vaf is amplified by the amplifier 14, and is further amplified by the sampling hold 15. Control signal voltage Va at each point is generated based on the sampling period. f to be stored in the memory element 10.

Next, to explain the recording process, the RFC switch 9 becomes conductive,
The control signal voltage Va generated based on the sampling period from the memory element 10 is amplified by the amplifier 16 and applied to the piezoelectric effect element electrode 4, thereby displacing the head position 'ff: for each rotating video head. , recording is performed while maintaining the regular positional relationship.

During playback, as explained in the auto-tracking section, playback is performed while controlling the video head to a position where the maximum output can be obtained, without going through the block diagram in FIG.

In addition, in the above embodiment, the piezoelectric effect element was attached to the head bar, but as shown in FIG.
Even when it is attached to the head bar 18 through 1, the same effect as in the above □ embodiment can be obtained. Note that 20 is a hole for the shaft.

Therefore, in the present invention, the rotating head 5 is attached to a rotating body such as the head bar 2 so as to be displaced by a member filter such as a piezoelectric effect element 5 that is displaced by the application of an electric signal, and the rotational head 5 is moved around the rotational trajectory of the rotating head 5. Head drum 1 with a surface
A rotary head type magnetic recording and reproducing device in which a predetermined stratum corneum magnetic tape 8 is wound around and run, and by applying a control signal to a reproducing line member 6, the rotary head 5 scans the entire recording track well. In this step, the control signal voltage Va is stored in the memory element 10 by reproducing the standard chip 11 in advance by the rotary head 5, and the position of the head is controlled by the control signal read from the above-mentioned mesh stringer 10 at the time of recording. Because of this, the height accuracy of the video head is extremely rough, and there is no need to adjust the position of the control head.

[Brief explanation of drawings]

FIG. 1 is a plan view of an embodiment of the present invention, and FIG. 2 is an enlarged side view of the main part of FIG. FIG. 6 is an electrical block diagram of one embodiment, and FIG. 4 is a voltage waveform diagram of the control signal vehicle pressure Va during a period in which the rotary head 5 draws one field. FIG. 5 shows another embodiment. 2: head bar, 3: piezoelectric effect element, 4: piezoelectric effect element electrode, 5: rotating head, 10: memory element 1,

Claims (1)

[Claims] A rotary head is attached to a rotary body so as to be displaced by a member such as a piezoelectric effect element that is displaced by the application of an electric signal, and a magnetic tape is wound at a predetermined angle around a head drum having a surface along the rotation locus of the rotary head. Let it run,
In a rotary head type magnetic recording and reproducing device in which the rotary head scans the recording track well by applying a control signal to the member during reproduction, the above control is performed by reproducing a standard tape in advance with the rotary head. 1. A rotary head type magnetic recording and reproducing apparatus, characterized in that a signal is stored in a memory element, and during recording, the position of the head is controlled by a control signal read from the memory element.