JPH01158612A - Method for positioning rotary magnetic head - Google Patents

Abstract

PURPOSE:To correctly adjust the angles of rotary magnetic heads to a partial center dislocation and an eccentricity by adjusting the position of a microscope with a drum as a standard. CONSTITUTION:A sensor 22 facing to the circumference face of a drum 1 is provided for an arm 21 of a moving table 16. An interval Xd between the sensor 22 and the drum 1 is detected by the sensor 22 and a direct-current voltage Vx of a corresponding level is generated by a detecting circuit 23. On the other hand, a direct-current voltage Ex corresponding to the interval between the drum 1 and the sensor 22 when an optical axis L of the microscope 15 passes through the center of the drum 1 is set beforehand. The voltages Vx and Ex are compared by a voltage comparing circuit 24 and a comparison output is supplied to a drive motor 17M. The motor 17M servo-controls the position of the table 17 in an X direction so that the voltages Vx and Ex may become equal. Then, even when there partially are the center dislocation and the eccentricity, the voltages Vx and Ex are made equal by the above-mentioned servo control. Then, the voltage Ex is adjusted like mentioned above, therefore, the optical axis L of the microscope 15 passes through the center of the drum 1 and the angles of magnetic heads 2A and 2B can be correctly adjusted.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for positioning a rotating magnetic head.

[Summary of the invention]

The present invention provides a method for positioning a rotating magnetic head.
By regulating the relative position of the rotating drum and the microscope of its assembly device with the rotating drum as a reference,
This allows the position of the rotating magnetic head relative to the rotating drum to be determined accurately.

[Conventional technology]

In VTRs, R-DATs, and the like, signals are recorded and reproduced on tape using a rotating magnetic head device. Generally, in a rotating magnetic head device,
Two rotating magnetic heads must be mounted on the rotating drum so that their angular spacing is 180°.

For this reason, the angular spacing of the rotating head can be adjusted by using an assembly device (adjustment jig) as shown in FIGS. 4 and 5, for example.
It is adjusted to 80°.

That is, in the same figure, (1) indicates a rotating drum,
In this figure, magnetic heads (2A), (2B) whose angular spacing is to be adjusted are placed on the top surface of the drum (1).
are attached with an angular spacing of approximately 180°.

In addition, (11) indicates the drum mounting base, (12) indicates its rotation axis, and these members (11) and (12) -
It is rotatably held by a bearing (13). For drum +1>, the upper end of the rotating shaft (12) is connected to the shaft hole (IH) in the center of the drum (1).
The installation is done by penetrating the stand (11) and Nando (1).
4) is fixed to the rotating shaft (12).

Further, (15) indicates a microscope (particularly its lens barrel portion with a lens thread), which is arranged so that its objective lens (not shown) faces the surface of the drum (1). This table (
The movement of 16) allows the microscope &14 (15) to move forward and backward in the direction of its tip axis (referred to as the Y direction).

Further, the table (16) is attached to a moving table (17), and the microscope (15) is moved integrally with the table (16) in the Y direction and in a direction perpendicular to the rotation axis (12) (
It is possible to move in the X direction).

And a head (2A) for the rotating drum (1).

When adjusting the assembly of (2B), first make sure that the optical axis of the microscope (15) passes through the center of the rotation axis (12).
The position of I(15) in the X direction is set. Next, the head (2A) is attached to the drum (1), and
At this time, the angular position of the head (28) is the reference position, that is, the head (28) is aligned with the optical axis.
The corner position of A) is adjusted and fixed.

Subsequently, the drum (1) is driven by the rotating shaft (12) and rotated 180 degrees around the rotating shaft (12), and the head (2B) is attached to the position of the head (2A) before this rotation. At the same time, the angular position of this head (2B) is adjusted and fixed to the reference position (optical axis L).

Therefore, with the above assembly and adjustment, the head (
The angles of 2A) and (2B) are set to 180°.

Document: Japanese Unexamined Patent Publication No. 61-68722 [Problem to be solved by the invention] However, in reality, in order to be able to attach the drum (1) to the rotating shaft (12), The shaft hole (
Due to variations in machining accuracy during machining of IH), drum (
There is some clearance between the shaft hole (IH) of 1) and the center shaft (12), and due to this there is a slight clearance on the drum <1> with respect to the optical axis and the center shaft (12). will cause misalignment.

If there is misalignment, for example, as shown in Figure 6A (the O mark is the center point of the drum (1), the x mark is the axis (
12) (indicates the center point of
``When the head (IB) is rotated and fixed at the reference position, as is clear from Figure B, point X is the center of rotation, so the angle of the head (IB) is as follows: (IB) causes an error twice that of the vehicle body.

This also applies when the rotating shaft (12) rotates eccentrically with respect to the bearing (13), resulting in an error.

This invention attempts to solve these problems.

[Means for solving problems]

For this reason, in the present invention, when a plurality of magnetic heads are provided on a rotating drum, a sensor provided on a microscope for observing the magnetic heads or means supporting the microscope is used to detect the optical axis of the microscope and the rotation of the magnetic heads. The distance between the rotating drum and the sensor is detected in a direction perpendicular to the rotating shaft supporting the drum, and based on this detection output, the optical axis is set so that the optical axis passes through the center of the rotating drum. A method for positioning a rotating magnetic head, in which a positional relationship between a microscope and the rotating drum is set, and after this setting, the position of the magnetic head on the rotating drum is adjusted using the microscope. .

[Effect]

Even if there is eccentricity in the rotation of the drum (1), the head (LA)
.

The angle of (IB) is adjusted to the correct 180°.

〔Example〕

In Fig. 1, the advance/retreat table (16) has an arm (
21), and this arm (21) is provided with a rotating shaft (12) facing the circumferential surface of the drum (11).
Place the sensor (
22) is provided, and this sensor (22) detects the drum (
1) and the sensor (22) is detected.

The output of this sensor (22) is detected by the detection circuit (23).
) and has a level corresponding to the interval Xd.
The distance between the drum (1) and the sensor (22) when this voltage Vx is supplied to the voltage comparator circuit (24) and the optical axis of the microscope (15) passes through the center of the drum (1). X
The voltage is compared with the voltage E corresponding to o, and the comparison output is sent to the horizontal movement table (17) through the drive amplifier (25).
) drive motor (17M).

According to such a configuration, the position of the table (17) in the X direction is servo-controlled so that Vx =Ex. Then, if Vx = E, then Xd-N
o, the optical axis of the microscope 1 (15) passes through the center of the drum (1) in the X direction.

Then, as described above, the head (2^).

(2B) is installed and adjusted.

In this way, the heads (2^) and (2B) are mounted and adjusted, but in this case, according to the present invention, the microscope &I! (15) is regulated, so even if there is misalignment between the center of the drum (1) and the rotating shaft (12), or if the rotating shaft (12) is aligned with the bearing (13). Even if there is eccentricity, the head (2A)
, (28) is adjusted to exactly 180°.

In addition, in this way, the center of the drum (1) and the rotating shaft (12
) even if there is a misalignment between the head (2A).

Since the angle of (2B) can be adjusted to the correct 180°, center alignment when attaching the drum (11 to the rotating shaft (12)) and rotation accuracy of the rotating shaft (12) are not absolute requirements. The fitting accuracy is good at an average level.

Therefore, there is no need for precision fitting jigs, and the drum (1) can be easily attached and detached, reducing the tout time and improving work efficiency.

In the example shown in FIG. 2, the position of the microscope (15) in the Y direction is also controlled.

That is, at the bottom of the tip of the microscope (15) there is a rotating shaft (1
2) Align the drum (
Another sensor (32) is provided opposite to the drum (1), and this sensor (32) detects the distance Yd between the drum (1) and the sensor (32).

The output of this sensor (32) is detected by the detection circuit (33).
) and has a level corresponding to the interval Yd.
y, and this voltage vy is supplied to the voltage comparator circuit (34) to detect the difference between the drum (L) and the sensor (3) when the detection center of the sensor (22) passes through the center of the drum (+1) in the X direction.
2) is compared with the voltage EV corresponding to the interval Yo,
The comparison output is supplied to the drive motor (16M) of the forward/backward table (16) through the drive amplifier (35).

Therefore, the position of the microscope (15) in the Y direction is
Since the drum (11) is controlled to a predetermined position as a reference, from now on, for example, the heads (2A) and (2B) are moved so that the heads (2A) and (2B) observed with the microscope &1i (15) are in focus. By adjusting the amount of protrusion from the drum (1), the amount of protrusion can be set to a specified value.

In the example shown in FIG. 3, a pair of means (15) to (17) are symmetrically provided on both sides of the drum (1). Therefore, two heads <2A)
, (2B) can be assembled and adjusted simultaneously.

In addition, in the above description, the MmIa (15) is moved, but the rotating shaft (12) and the drum (1) may also be moved. Alternatively, the microscope (15) may be manually moved so that the magnitude of the voltage vx (Vy) becomes a predetermined value E (Ey). Furthermore, the number of heads may be two or more, and the angle thereof is not limited to 180°.

〔Effect of the invention〕

According to this invention, since the position of the w4 micromirror (15) is regulated with respect to the drum (1), there is no misalignment between the center of the drum (1) and the rotating shaft (12). Even if the rotary shaft (12) is eccentric with respect to the bearing (13), the angles of the heads (2A) and (2B) will be correctly adjusted to 180°.

In addition, in this way, the center of the drum (1) and the rotating shaft (12
) even if there is a misalignment between the head (2A).

Since the angle of (2B) can be adjusted to a maximum of 180", center alignment when attaching the drum (1) to the rotating shaft (12) and rotation accuracy of the rotating shaft (12) are no longer absolute requirements. The fitting accuracy is good at an average level. Therefore, a precision jig for fitting is not required, and the drum (1) can be easily attached and detached, so that the tout time of the operation can be shortened, and the work efficiency is improved.

[Brief explanation of the drawing]

Figures g81 to 3 are plan views of an example of this invention, and Figures 4 to 3 are plan views of an example of this invention.
FIG. 6 is a diagram for explaining this. (1) is a rotating drum, (2A), (2B) are magnetic heads, (15) is a microscope, (16), (17)
is a table, and (22) and (32) are sensors.

Claims (1)

[Claims] In the case where a plurality of magnetic heads are provided on a rotating drum, the optical axis of the microscope and the rotating drum are controlled by a sensor provided on a microscope for observing the magnetic heads or means supporting the same. The distance between the rotating drum and the sensor is detected in a direction perpendicular to the supported rotating shaft, and the microscope and the sensor are arranged so that the optical axis passes through the center of the rotating drum based on this detection output. A method for positioning a rotating magnetic head, comprising: setting a positional relationship with the rotating drum; and after setting, adjusting the position of the magnetic head on the rotating drum using the microscope.