JPS58100220A - Forming machine for tape for regulating magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To obtain a stable, high-precise tape for regulation easily, by moving a rotary magnetic head in a rotating-shaft direction and forming a track coincident with a reference pattern on a magnetic tape. CONSTITUTION:By bimorph elements 18 and 19 which are corrected in terms of displacement due to hysteresis through strain gauges 28 and 29 respectively and fixed in height position by the 2nd bimorph elements 22 and 23, rotary magnetic heads 16 and 17 are moved in a rotating-shaft direction to adjust their height positions freely. While the bimorph elements 18 and 19 are fed with no electricity, the heads 16 and 17 form tracks on a tape. Those tracks are observed through a microscope, etc., to decide on differences from a reference pattern track, and thus electricity feeding to the bimorph elements 18 and 19 is controlled to specify the heights of the head 16 and 17, thus forming a stable, high- precise tape for regulation easily without any influence of hysteresis of the bimorph elements 18 and 19.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an adjustment tape making machine necessary for manufacturing magnetic recording and reproducing devices (hereinafter referred to as VTRs).

Traditionally, manufacturing VTRs requires many types of adjustment tapes (recorded tapes that are recorded faithfully to standards) to adjust the mechanism and circuits, and the linearity of the video signal recording track is particularly important for VTR performance. This is an important item to determine, and the tape that serves as the adjustment standard is required to have highly accurate linearity of several μm.

Recently, there has been significant progress in increasing the density of recording tracks.
If the VTR to be adjusted is also required to have highly accurate linearity of several μm. However, as shown in Fig. 1, the cylinder device of the adjustment tape making machine has traditionally been equipped with a video head (
A fixed cylinder (3) is provided coaxially with a rotating cylinder (2) equipped with 1), and both cylinders (2) (3)
A magnetic tape (4) is spirally wound around the outer circumference of the fixed cylinder (3), and a spiral tape guide portion (
5), the magnetic tape (4) is run with the end face of the magnetic tape (4) aligned with the magnetic tape (4), and has the same configuration as a commercially available VTR. Dependent. For this reason, a high degree of processing precision is required for the guide part (5), and recent processing technology requires a precision of 2 to 8 μm.
It is possible to process up to a certain level of linearity. However, the adjusted VT
In the current situation where the precision of R is increasing, even higher precision is required of the adjustment tape, and it is difficult to improve the precision through processing. In addition, if we include linearity errors due to the strength and weakness of the magnetic tape guide and assembly errors of the cylinder device, the total video track linearity error will increase, so we need to reduce the errors for each of the above error factors. However, since there is a limit to the improvement of processing accuracy and adjustment accuracy, it is necessary to introduce a means to cancel these total errors.

The present invention provides a cylinder device comprising a cylinder for winding and guiding a magnetic tape, and a magnetic head that protrudes from the outer peripheral surface of the cylinder by a predetermined amount and rotates to record signals on the magnetic tape, in which the magnetic head is rotated. Preparation of a tape for adjusting a magnetic recording/reproducing device, which is provided with means for moving in the axial direction, and configured to move the magnetic head so that the magnetic head records a magnetization track that matches a magnetic pattern reference value on the magnetic tape. According to this configuration, it is possible to create an adjustment tape with extremely excellent linearity. Furthermore, in the present invention, the means for moving the magnetic head in the direction of the rotation axis is constituted by a bimorph made of two piezoelectric materials, and
means for regulating the height of the magnetic head in the rotational axis direction;
Means for detecting the difference in height of the magnetic head between when the height is regulated by the regulating means and when the current supply to the bimorph is stopped is provided, and the supply voltage to the bimorph is determined by the signal from the detecting means. The present invention provides a tape making machine for adjusting a magnetic recording/reproducing device, characterized in that it is configured to control.

Hereinafter, a first embodiment of the present invention will be described based on FIGS. 2 to 4. In Figures 2 and 3, the rotating cylinder (
In 6), bimorphs 0v (to), which are attached to the fixing members (7) and (8) at one end and equipped with a video head (9) αQ at the other end, are provided at 180 degrees from each other,
Each of the bimorph α eyes (2) is composed of two piezoelectric material plates, and is connected to the video head (9) by external power supply.
) The mounting side of <10 is configured to move in the direction of the rotation axis.

In the above configuration, a video signal is first recorded in a bimorph-like manner (2) with no current applied, the tracks are developed with fine iron powder, etc., and the linearity of the tracks is measured with a microscope, as shown in Figure 4(a). Head entry side (A) as shown by the solid line.
The error (T) at each position with respect to the reference value <2> from to the exit side (su) is clarified.

Next, based on the above measurement results, the bimorph CI at each position is
]) Set the supply voltage to υ [dashed line in Fig. 4 (a)],
If the supply voltage is supplied to the bimorph αη(2) during recording, highly accurate linearity can be obtained as shown in FIG. 4(b). At this time, the supply voltage can be set by changing the set value for each position of the head using multiple dip switches or rotary switches (the broken line in Figure 4 (a) is an example), or by continuously using an electric circuit. One possible method is to generate a voltage with a phase opposite to the linearity error, but the latter method allows for more accurate correction.

However, the configuration of FIG. 2 has the following drawbacks. In other words, the bimorph α1) (2) made of piezoelectric material has a hysteresis phenomenon in which the mechanical deformation does not return even if the supply voltage is returned to zero, and the amount of deformation also changes over time, so the video head The absolute height changes and the video center height changes.

A second embodiment that solves this problem is shown in FIGS. 5 to 8. The rotating cylinder (c) has a first member fixed to the fixed member a→Q field at one end and equipped with a video head OQa force at the other end.
A bimorph (to) 0 is provided, and the first bimorph Q to 09 is made up of two piezoelectric material plates, and the video hand 0→αη force (moves in the direction of the axis of one rotation) when energized from the outside. It is constructed as follows.The fixing member is)
21) with the central part attached to the second bimorph (a) t
A regulating member chant 0) (a) is provided at both ends of +.
By applying electricity to the wire of the second bimorph and moving it in the direction (α) in FIG. 7, the first bimorph (g)
Insert the area near the video head handle of 09. Further, the regulating members (c), (c), and (a) are provided with V-shaped notches (to) as shown in FIG. 8, and the notches (1)
Since the first bimorph (11) is provided with a V-shaped protrusion OD so as to engage with the first bimorph (11), the height of the first bimorph (11) is regulated in the direction of the rotation axis by being sandwiched therebetween. This state is used as the reference for the head height.Also, when the second bimorph (e) is de-energized, the regulating members (c) (c) (b) and (b) become (β) as shown in FIG. If the configuration is such that the first bimorph (g) 09
becomes movable in the direction of the rotation axis again. Further, a strain gauge (c) is attached to the first bimorph 057H, and is configured to detect the deflection of the first bimorph ae aa in the direction of the rotation axis.

In the above configuration, the unit constituted by the first bimorph (to) α-katsu is the same as the first embodiment described above, so the explanation will be omitted, and the unit constituted by the second bimorph (to) The relationship between this and the first bimorph (goods) Q◇ will be explained. The strain gauge (
e) When the height of the video head (lf9 (lη
A constant correction voltage is applied to each of the first bimorph O1 (+1) so that the height is the same as the height standard of the first bimorph OE90, and the height error of the video head 060η due to mechanical deformation of the first bimorph OE90 is corrected. By performing the above checks before creating the adjustment tape, changes in the video center height can be prevented.

According to the present invention described above, the magnetic head is configured to be movable in the direction of the rotation axis, and the magnetic head is moved so that the magnetic tracks recorded on the magnetic tape form a straight line, thereby achieving high precision. A VTR adjustment tape having video trunk linearity can be created, and the video track linearity of the VTR to be used can be improved. As a result, commercially available VT
The image quality during compatible reproduction of R is improved, and recording density can be further promoted. Further, even when the adjustment tape is produced using a plurality of adjustment tape production machines, there is no variation between the production machines, so it is possible to produce the adjustment tape with stable accuracy.

It also makes it easier to make adjustments during device manufacturing, and
Even if the performance of the device changes due to changes over time, it is possible to readjust it easily, improving work efficiency. It is also effective in reducing the cost of the device and the tape to be produced.

By detecting the position displacement due to hysteresis of the first bimorph (to) (to) by the strain gauge storage (2) and supplying a correction voltage to the first bimorph (to) 01, the height of the center of the video can be adjusted. It is possible to prevent changes and create highly accurate and stable adjustment tapes.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a conventional cylinder device, FIG. 2 is a front view showing a first embodiment of the present invention, FIG. 8 is a sectional view showing a bimorph configuration of the first embodiment, and FIG. ) (b)
5 is a front view showing the video track linearity and the movement of the bimorph, FIG. 6 is a sectional view of the second embodiment, and FIG. 7 is a graph showing the video track linearity and the movement of the bimorph. 1
FIG. 8 is a perspective view of the main parts showing the relationship between the bimorph and the second bimorph, and an enlarged view showing the shape of the engaging part between the first bimorph and the second bimorph. (6)...Rotating cylinder, (7) (8)...Fixing member, (9) OO...Video head, (II) (2
)...bimorph, (to)...rotating cylinder, α
Φ0Q...Fixing member, 060η...Video head,
0 mark 0su...first bimorph, wa])...fixing member, (a) (e)...second bimorph, (c)01(
A) (B)...Regulating member, (E) Hanging...Strain gauge, (To)...Notch, 0η...Protrusion agent Yoshihiro Morimoto Figure 4 (d) Figure 5 Figure 1 Figure 7 Figure i

Claims (1)

[Scope of Claims] 1. A cylinder device comprising a cylinder for winding and guiding a magnetic tape, and a magnetic head that protrudes from the outer peripheral surface of the cylinder by a predetermined amount and rotates to record signals on the magnetic tape. The method is characterized in that a means for moving the magnetic head in the direction of the rotation axis is provided, and the magnetic head is moved so that the magnetic head records a magnetization track on the magnetic tape that matches a magnetic pattern reference value. Tape making machine for adjusting magnetic recording and reproducing equipment. 2. A means for moving the magnetic head in the direction of the rotation axis;
a bimorph made of two pieces of piezoelectric material, means for regulating the height of the magnetic head in the direction of the rotational axis, and a means for regulating the height of the magnetic head in the direction of the rotational axis, and the above-mentioned conditions when the height is regulated by the regulating means and when the bimorph is no longer energized. 2. The magnetic head according to claim 1, further comprising: means for detecting a height difference between the magnetic heads; and a signal from the detecting means is used to control the voltage supplied to the bimorph. Tape making machine for adjusting recording/playback equipment.