JPS58196653A - Magnetic tape guide device - Google Patents

Abstract

PURPOSE:To obtain a tape guide device of a simple structure requiring no large power and is excellent in responsiveness, by using a piezoelectric element to a tape guide supporting member and deforming the piezoelectric element with a control signal to control the tape guide in its width direction. CONSTITUTION:A piezoelectric element is used to a supporting member of a tape guide 14,and the guide 14 is moved in the width direction of a tape 10 as shown by the arrow mark by means of the deformation due to a piezoelectric effect. A recording level detector 36 detects the level of a reproduced signal fed from a head 12, and a control signal is supplied to a voltage variable power supply 34 so as to obtain the maximum level of the reproduced signal through an arithmetic device 36. The member 16 is deformed by the control voltage, and the guide 14 is shifted in the tape width direction to have matching of tracks. In such a way, the necessary power is reduced for a tape guide device with a simple constitution and excellent responsiveness.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic tape guide device for reliably aligning the tracks of a magnetic tape and a magnetic head in a magnetic recording/reproducing apparatus.

In a tape recorder, when a signal is reproduced, if the relative position of a track on a magnetic tape (hereinafter referred to as tape) and a magnetic head (hereinafter referred to as head) changes, the level of the reproduced signal fluctuates or decreases. In order to reduce this level fluctuation, it is necessary to adjust the tracks of the seven heads of the tape. However, in reality, slight changes in the relative position of the capstan and pinch roller, fluctuations in tape height due to fluctuations in tape tension, and discrepancies in the height of the head installation may cause the track between the tape and the head to change.
Misalignment occurs. This track misalignment is a problem in general 2-track and 4-track systems, but it is especially serious in systems with a large number of tracks, such as PCM recorders.
This becomes a problem.

Previously, as a countermeasure to this problem, there have been examples of controlling the head to move in the height direction, but this example was applied to a lightweight head such as an i-dio head, and not a heavy one such as an audio head. There were problems with the required control force, responsiveness, head holding strength, etc. when applying it to objects. 'The present invention has been made to solve the above-mentioned problems, and an example in which the invention is applied to an audio cassette tape recorder will be described below with reference to the drawings.

FIG. 1 shows a perspective view of the head section of a tape recorder embodying the present invention. 1o is a magnetic tape, 12 is a magnetic head, 14 is a tape guide provided immediately upstream of the head 12, and 16 is a piezoelectric support member for moving the tape guide 14 in the width direction of the tape. The tape guide 14 is moved by utilizing the deformation caused by.

A fixing member 17 supports the piezoelectric support member 16 and fixes it to the head substrate 22. 18 is a capstan, 20 is a pinch roller, 22 is a head board, 24 is a cassette tray 1-7
It is.

In the present invention, a piezoelectric element is used as the tape guide support member, and the tape guide 14 is moved using minute expansion and contraction that occurs when an electric field is applied.

The support member 1 has a bimorph structure made of two pieces of piezoelectric material bonded together to obtain the amount of movement, that is, deformation, and the total efficiency.
6 is used.

FIG. 2 shows a piezoelectric support member 16 and a fixing member 17 having a bimorph structure. 26 and 27 are rectangular piezoelectric materials made of piezoelectric ceramic, each having electrodes 28, 29, 3 on both sides.
0.31 is set. The two piezoelectric ceramics are polarized in the thickness direction of the plates, and are bonded together with an adhesive 32 so that the polarization directions are the same. and variable voltage power supply 34
If wired as shown in the figure, if one piezoelectric material expands, the other will contract, causing the tip to bend and displace as shown by the arrow. The displacement obtained by this bimorph structure is significantly larger than that obtained by simple expansion and contraction, and the advantage is that a lower voltage is required to obtain the same displacement, which is good efficiency.

FIG. 3 shows a control circuit of a tape guide device using the piezoelectric support member 16 described above. 36 is a recording level detection device that detects the level of the reproduced signal from the head 12, and compares the level with the previous value by an arithmetic device 38, while varying the voltage of the control signal i so that it always takes the maximum value. It outputs to the power supply 34. Then, the piezoelectric support member 16 is deformed by the voltage controlled in this way, and the tape guide 14 moves as shown by the arrow in the figure, and the tape 1
This is to perform track alignment between the head 12 and the head 12.

Track alignment between the tape 1o and the head 12 can be achieved by detecting the playback signal level from the head 12 and controlling the piezoelectric support member 16 and tape guide 14 so that the level is maximized as described above. .

Since this tape guide device drives the tape guide to perform track alignment, it has the advantage that the required force is smaller than that of a head-driven type, and it has excellent responsiveness. It has the advantage of being immersed in controllability by being placed in the area. In addition, piezoelectric elements have the advantage that they consume less power because almost no current flows through them, and that they have a simple structure because they directly convert electrical quantities into mechanical quantities. Furthermore, by making the piezoelectric element have a bimorph structure, a large displacement can be obtained with a low voltage, and it can be easily implemented. Since the piezoelectric element can precisely control displacement by controlling the applied electric field, highly accurate positioning is possible.

As described above, the magnetic tape guide device of the present invention performs track alignment by changing the height of the tape guide, so the required force is small and the responsiveness is excellent. By changing the height of the tape guide by deforming the support member,
It has the advantages of simple structure and high precision.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the present invention, FIG. 2 is a perspective view of the piezoelectric element portion, and FIG. 3 is a control circuit diagram. 1o...Magnetic tape, 12...Magnetic head, 14...Tape guide, 16...
Piezoelectric support member, 17...Fixing member, 22...
・Head board, 34...Variable voltage power supply.

Claims (1)

[Claims] (1) A means for generating a control signal based on a corresponding track deviation between the magnetic tape and the magnetic head, and a magnetic tape guide means configured to be displaced in the width direction of the magnetic tape in response to the control signal. A magnetic tape guide device comprising: (A patent claim characterized in that the magnetic tape guide means has a piezoelectric support member that deforms in response to a control signal, and a magnetic tape guide member that is displaced in the width direction of the magnetic tape based on the deformation of the piezoelectric support member. The magnetic tape guide device according to scope 1.