JPH054094Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a device for positioning a magnetic head supporting cylinder used in a VTR device or the like when the magnetic head is attached.

(Prior Art) In order to attach a magnetic head to a cylinder with high precision in a VTR device, etc., it is necessary to position the cylinder, particularly the circumferential surface, with high precision prior to attaching the magnetic head.

Therefore, in the past, a tapered support shaft was inserted into a hole formed in the center of the cylinder, and the centering and positioning was performed by the action of this taper.

Also, after inserting the support shaft into the cylinder hole,
There was also a method of centering and positioning by inflating the spindle with air.

(Problems to be Solved by the Invention) However, with the above conventional means, it is difficult to form the support shaft with high precision, and there is a limit to improving the positioning precision of the cylinder. In addition, in the above case, the center of the hole in the center of the cylinder is aligned with the set point (in this case, the center of the spindle), but if the center of this hole is slightly offset from the center of the circumferential surface of the cylinder. In this case, an error occurs in the positioning of the circumferential surface of the cylinder due to this deviation.

As a result, the magnetic head could not be attached to the cylinder with high precision.

(Means for Solving the Problems) The present invention was made to solve the above problems, and its gist is (a) It has two moving stages movable in mutually intersecting directions, and has magnetic A support mechanism that supports a cylinder for supporting the head; (b) two moving mechanisms that have drive motors and move each moving stage by the drive of these motors; and (c)
Two sets of two pieces are arranged near the circumferential surface of the cylinder supported by the support mechanism, and two pieces of each set are arranged in the direction of movement of each moving stage with the set point as the center.
a non-contact circumferential surface position detector that is arranged 180 degrees opposite to each other and detects the position of the circumferential surface of the cylinder;
(d) Based on the deviation of the electrical signals from the two circumferential position detectors of one set and the deviation of the electrical signals from the two circumferential position detectors of the other set, the center of the cylinder is determined. A positioning device for a cylinder for supporting a magnetic head is characterized in that it is provided with two drive control circuits for respectively driving and controlling the motors of each moving mechanism so that the position of the magnetic head corresponds to the set point.

(Function) The two drive control circuits detect the deviation of the electrical signals from the two circumferential position detectors of one set and the deviation of the electrical signals from the two circumferential position detectors of the other set. Based on this, each motor is driven to move each movement stage, so that the center of the circumferential surface of the cylinder coincides with the set point.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. In the figure, reference numeral 1 denotes a cylinder whose circumferential surface 1a is a cylindrical surface and has a circular hole 1b in the center, and two magnetic heads 2, for example, are attached to one surface of the cylinder.

The cylinder 1 is supported by a support mechanism 10 shown in FIG. This support mechanism 10 includes a movable stage 12 movable in the Y-axis direction with respect to a base 11, a movable stage 13 movable in the X-axis direction, a support base 14 fixed to the movable stage 13, and a support base 14 fixed to the movable stage 13. The holding member 15 is detachably attached to the stand 14.
Note that in this embodiment, the intersection angle between the X axis and the Y axis is not a right angle. A cylindrical support shaft portion 14b is formed at the center of the upper surface 14a of the support base 14. Support shaft part 1
4b is formed with a screw hole 14c, into which a screw rod 15a of the holding member 15 is screwed.

Each moving stage 12, 13 of the support mechanism 10
are adapted to be moved by two moving mechanisms 20, respectively. Each moving mechanism 20 includes a cylindrical case 21, a hollow rod 22 inserted into the distal end of the case 21 in a slidable but non-rotatable manner, and a servo motor (motor) 23 housed in the case 21. It has a reduction gear train 24 connected to the output shaft 23a of the servo motor 23, and a rotary shaft 25 connected to the reduction gear train 24. A male threaded portion 25a is formed at the tip of the rotating shaft 25.
a is screwed into a female thread 22a formed on the inner peripheral surface of the rod 22. For example, the rotating shaft 25 rotates at a reduced speed due to the forward rotation of the servo motor 23, and the rod 22 moves forward due to the screw action between the male threaded portion 25a and the female threaded portion 22a. Further, the rod 22 is moved backward due to the reverse rotation of the servo motor 23. moving stage 12,
13 are each urged in the direction of the rod 22 by the action of a spring (not shown), so that the movable stages 12 and 13 are always in contact with the tip of the rod 22 and are moved following the forward and backward movements of the rod 22. ing.

Around the support mechanism 20, for example, capacitance type (non-contact type) circumferential position detectors 30A, 30A,
A total of four pieces of 30B and 30B are arranged. Of these, two circumferential position detectors 30A, 30A are arranged as a pair on the X axis passing through the set point O, and similarly, two circumferential position detectors 30B, 30
A set of B is arranged on the Y axis passing through the set point O. The above two circumferential position detectors 30A, 3
0A are equal distances apart from each other from the set point O.
They are 180 degrees opposed to each other, and the same is true of the other two circumferential position detectors 30B, 30B.

Note that the support stand 1 in the support mechanism 10 described above
The center of the support shaft portion 14b of No. 4 is located at a position that approximately coincides with the above-mentioned set point O, although it is not exact.

FIG. 3 shows a drive control circuit 40 for the servo motor 23 that moves one of the moving stages 13. The drive control circuit 40 includes a differential amplifier 41 that receives signal voltages from the two circumferential position detectors 30A and 30A, and a power amplifier that is connected to the operating amplifier 41 and controls the output voltage to the servo motor 23. It consists of 42. Although not shown, the drive control circuit for the servo motor 23 that moves the other moving stage 12 is configured similarly, and the other set of circumferential position detectors 30B, 3
The servo motor 23 is driven and controlled based on the signal voltage from 0B.

As shown in FIG. 1, optical measuring devices 51 and 52 are arranged 180 degrees opposite each other with the set point O as the center. The optical measurement devices 51 and 52 optically measure the position, attitude, etc. of the magnetic head 2 with respect to the cylinder 1.

The operation of the above configuration will be explained. First, as shown in FIG. 2, the cylinder 1 is set on the support mechanism 10. That is, the circular hole 1 at the center of the cylinder 1 is inserted into the support shaft portion 14b of the support base 14, and the cylinder 1 is placed on the upper surface 14a of the support base 14. Next, the threaded rod 15a of the holding member 15 is attached to the support base 14.
This holding member 1 is screwed into the screw hole 14c of
5 to press down cylinder 1.

Next, the center of the cylinder 1 is aligned with the set point O. To be more specific, signal voltages from the two circumferential position detectors 30A, 30A are sent to a differential amplifier 41 of a drive control circuit 40, and the amplified deviation voltage is sent here to a power amplifier 42. This power amplifier 42 performs output control to the servo motor 23 so that this deviation voltage becomes zero. As a result, the servo motor 23 is activated to move the moving stage 13 by a small amount in the X-axis direction. Similarly, other servo motors are controlled by other control circuits based on the deviation voltages of the two circumferential position detectors 30B, 30B, and the moving stage 12 is moved in the Y-axis direction. As a result, the center of the cylinder 1 can be made to coincide with the set point O with high precision.

As described above, the position of the circumferential surface 1a of the cylinder 1 is detected and the center of the cylinder 1 is positioned based on the detected position of the circumferential surface 1a, so even if there is a shift in the center of the hole 1b, this will not occur. Highly accurate positioning can be performed regardless of the situation.

After that, the optical measurement devices 51 and 52 measure the amount of protrusion of the magnetic head 2 with respect to the cylinder 1, as well as other positions and postures, and based on the measurement results, a correction device (not shown) corrects the position, etc. Attach the head 2 to the top surface of the cylinder 1 with high precision. Incidentally, after the magnetic head 2 is attached to the cylinder 1, slight correction may be made to the correct position, or the magnetic head 2 may be attached to the cylinder after being accurately positioned.

The present invention is not limited to the above embodiments and can be modified in various ways. In the above embodiment, the moving stage 12
Although the intersecting angle between the movement direction (X-axis direction) and the movement direction (Y-axis direction) of the moving stage 13 is not a right angle, it is of course possible to make it a right angle.

(Effects of the invention) As explained above, in this invention, the circumferential position of the cylinder is detected using two circumferential position detectors that are 180 degrees opposite each other with the set point as the center, and the position is detected based on the deviation of the electrical signal. By driving the motor to move each moving stage, the center of the cylinder can be aligned with the set point with high precision. As a result, the magnetic head can be attached to the cylinder with high precision.

In addition, positioning can be performed automatically,
Since no manpower is required, work efficiency can be improved.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing a cylinder positioning device and an optical measuring device for a magnetic head according to the present invention, Fig. 2 is a longitudinal sectional view of the cylinder positioning device, and Fig. 3 is a plan view showing the cylinder positioning device together with an electric circuit. It is a diagram. DESCRIPTION OF SYMBOLS 1...Cylinder, 1a...Surrounding surface of cylinder, 10...Support mechanism, 12, 13...Movement stage, 20...Movement mechanism, 23...Servo motor (motor), 30A, 30A, 30B, 30B... …
Non-contact circumferential position detector, 40... Drive control circuit.

Claims (1)

[Claims for Utility Model Registration] (a) It has two moving stages movable in mutually intersecting directions, and has a support mechanism that supports a cylinder for supporting a magnetic head, and (b) It has a drive motor. , two moving mechanisms that move each moving stage by the drive of these motors;
(d) one set of non-contact circumferential surface position detectors, which are arranged 180 degrees opposite each other in the moving direction of each moving stage with the set point as the center, and detect the position of the circumferential surface of the cylinder; The center of the circumferential surface of the cylinder is set at the set point based on the deviation of the electrical signals from the two circumferential position detectors and the deviation of the electrical signals from the other set of two circumferential position detectors. 1. A positioning device for a cylinder for supporting a magnetic head, comprising two drive control circuits for driving and controlling the motors of each moving mechanism so as to match the movement mechanism.