JPS6319939Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a magnetic head mounting structure, and in particular, in a structure in which a magnetic head is mounted to a piezoelectric element such as a bimorph, an arm is provided on a mounting base member that holds the base side of the piezoelectric element. It is an object of the present invention to provide a magnetic head mounting structure configured to prevent damage to a piezoelectric element during mounting work and to facilitate position adjustment through the action of the arm.

Currently, various structures have been proposed for mounting a rotating magnetic head in helical scan type VTRs for the purpose of improving tracking accuracy, in which a magnetic head is mounted on the free end of a piezoelectric element such as a bimorph.

In this structure, the base side of the piezoelectric element is fixed to a mounting member, and the mounting member is fixed to a rotating drum. Conventional mounting structures have disadvantages in that the piezoelectric element is exposed outside the mounting base member, making it easy to damage the piezoelectric element during mounting work, and that adjustment of the mounting position is difficult.

The present invention eliminates the above two drawbacks at the same time by shaping the mounting base member that supports the base side of the piezoelectric element into a shape having a predetermined arm part.One embodiment of the present invention will be described below with reference to the drawings. .

Fig. 1 shows the structure of a part of the guide drum of a VTR device to which an embodiment of the magnetic head mounting structure of the present invention is applied, and Fig. 2 shows a structure in which the upper rotating drum in Fig. 1 is turned upside down. The main parts of this invention are shown. FIGS. 3 and 4 each show a position adjustment method during installation work.

In FIGS. 1 and 2, the guide drum 1 includes a lower stationary drum 2 and an upper rotating drum 4 that rotates integrally with a rotating shaft 3. As shown in FIGS. The video head 5 is attached to the lower surface of the rotating drum 4 by a head attachment mechanism 6, and is disposed on the opposite side in the diametrical direction (one is not shown).

In the head attachment mechanism 6, the video head 5 is attached to the tip of the bimorph 7, and the base side of the bimorph 7 is fixed to a mounting base member 8 with an adhesive or the like, and the mounting base member 8 is placed in a predetermined position in the lower surface of the rotating drum 4. It is screwed in place with a screw 9.

The mounting base member 8 is made of brass, and includes a base portion 8a,
A pair of arm parts 8b and 8c protrude from both sides, and a mounting base 8d protrudes upward at the base of the arm parts.
It becomes more. The base side of Bimorph 7 is the mounting base 8d.
It is adhesively fixed with adhesive 10 while being pressed against the mounting surface 8d _{-1 of} . In a state where the bimorph 7 to which the video head 5 is attached is attached to the mounting base member 8, the bimorph 7 has a pair of arm portions 8b.
In other words, the arms 8b and 8c extend along the left and right sides of the bimorph 7. Therefore, the arms 8b and 8c function as protective arms, and the operator's hands or instruments do not come into direct contact with the bimorph 7 during the installation work described later, thereby eliminating accidents of damage to the bimorph due to careless handling.

Mounting base member 8 to which bimorph 7 is adhesively fixed
The mounting base 8d is connected to the diametrical groove 4a of the rotating drum 4.
The base portion 8a is fitted into the rotating drum lower surface 4b.
With the screw 8 in contact with the hole 8 of the base portion 8a,
It is screwed and attached to the rotating drum 4 through a _-1 .

After this, the position of the video head 5 in the rotational direction,
Positioning work to accurately determine the amount of protrusion from the drum, the height position, etc. is performed as shown in FIGS. 3 and 4. This positioning work is carried out by attaching the drum 4 to a jig equipped with a microscope and checking the position of the head through the microscope.

For positioning, an eccentric pin jig 11 having an eccentric pin at its tip is used, and the rotating drum 4 has holes 4c, 4d, into which the eccentric pin jig 11 is fitted.
4e are the base part 8a, the arm part 8b, and the mounting member 8, respectively.
They are perforated at positions opposite to each other.

Regarding the amount of head protrusion, as shown in FIG. 3, the eccentric pin jig 11 is inserted into the hole 4c and rotated, and at this time, the eccentric pin 11a moves the wall surface 8a _-2 of the base portion 8a in the direction of arrow _X1. Adjustment is made by pushing the mounting base member 8 in the same direction.

Regarding the rotational position, that is, 180° division, please refer to the 4th section.
As shown in the figure, the eccentric pin jig 11 is inserted into the holes 4d and 4.
e, and rotate it. At this time, the eccentric pin 11a
The arrows mark the outer wall surfaces 8b _-1 and 8c _-1 of the arms 8b and 8c.
Adjustment is made by pushing in the Y ₁ and Y ₂ directions and rotating the mounting base member 8 around the screw 9. That is, the outer wall surfaces 8b _-1 of the arm portions 8b and 8c that perform the protective action,
8c _-1 functions as a contact portion with which the positioning jig comes into contact.

In addition, the height position can be determined by forcibly bending the mounting base 8d relative to the base portion 8a by changing the degree of screwing of the height position adjustment screw 12 screwed onto the drum 4. be adjusted. Here, since the mounting surface 8d _-1 of the mounting base 8d and the lower surface 4b of the drum 4 are located on the same plane, the video head 5 must be positioned near the desired height position before adjustment. Therefore, the above-mentioned height position adjustment can be made by finely adjusting the adjustment screw 12, which is convenient for the adjustment work.

Note that if the screws 9 are tightened after the above adjustment, there is a risk that the head position will change, so the screws 9 are tightened in advance to such an extent that tightening is not necessary after the adjustment work. However, the head of the screw 9 and the base part 8
A washer 13 made of nylon with low sliding friction resistance is inserted between the screw 9 and the screw 9, so that the mounting base member 8 will not move in response to the rotation of the eccentric pin jig 11. It moves smoothly and minutely, and adjustments are made accurately and easily.

Note that the ultra-fine head wires 14a and 14b are
The bimorph 7 is guided along the upper or lower surface, and the substrates 15a, 1 on the base portion 8a are guided from the mounting base thereof.
It leads to 5b. As a result, when the bimorph 7 moves in a curved manner, the head wires 14a,
There is no danger that 14b will be disconnected.

Alternatively, grooves or the like may be provided in the drum 4 at positions along the arm portions 8b, 8c, and a flat head screwdriver may be used as a jig for position adjustment. That is, by inserting a screwdriver into the groove and turning it, the arms 8b and 8c are pushed and the mounting base member 8 is rotated.
This adjusts the rotational position of the head.
In this case as well, the outer wall surfaces of the arm portions 8b and 8c function as contact portions against which the driver tips come into contact.

In the reproduction mode, a voltage corresponding to the tracking error signal is applied to the bimorph 7, causing it to curve up and down, and the video head 5 to move vertically to accurately scan the video track on the tape.

Further, the mounting base member 8 has a substantially U-shape and is lightweight. Furthermore, the mounting base member 8 is fixed with the base portion 8a located close to the center of the rotating drum 4, and its center of gravity is located close to the center of the rotating drum 4.
This makes it easier for the rotating drum 4 to which the mounting base member 8 is fixed to maintain a dynamic balance.

As described above, according to the magnetic head mounting structure of the present invention, the piezoelectric element can be protected by the pair of arms of the mounting member, and the pair of arms and the base are used for adjusting the mounting position. With the configuration in which the jig acts as a contact part and a hole into which the jig fits into the rotating drum is provided, the height, protrusion amount, and position in the rotational direction of the magnetic head relative to the rotating drum can be adjusted. Moreover, since the mounting base member is lightweight and consists of a base part and a pair of arms, and the center of gravity is close to the center of the rotating drum in the attached state, the dynamics of the rotating drum to which the magnetic head is attached is reduced. It has the advantage of being easy to balance.

[Brief explanation of drawings]

Fig. 1 shows an embodiment of the magnetic head mounting structure according to the present invention together with a guide drum to which this is applied, and Fig. 2 shows the magnetic head with the upper rotating drum in Fig. 1 turned upside down. The drawings showing the mounting structure, FIGS. 3 and 4, respectively show the head position adjustment state. 1...Guide drum, 2...Fixed drum, 4...
...Rotating drum, 4c, 4d, 4e...hole, 5...
Video head, 6... Head mounting mechanism, 7... Bimorph, 8... Mounting base member, 8a... Base part,
8b, 8c...Arm part, 8b _-1 , 8c _-1 ...Outer wall surface, 8d...Mounting base, 9...Screw, 11...Eccentric pin jig, 12...Height position adjustment screw, 13... …
Nylon washers.

Claims (1)

[Claims for Utility Model Registration] A flat piezoelectric element having a magnetic head attached to its tip and deformed by applying voltage; a base to which the base side of the piezoelectric element is attached;
a mount member comprising a pair of arms extending from the base portion along both sides of the piezoelectric element to protect the piezoelectric element from the outside; and the mount member is fixed to the base portion. a rotary drum that is attached and arranged adjacent to the base part and the pair of arm parts of the attached mount member and has a hole into which a jig or screw for adjusting the mounting position is inserted; The base portion of the base member serves as a contact portion against which the mounting position adjustment jig or screw comes into contact when adjusting the height and protrusion amount of the magnetic head relative to the rotating drum, and A magnetic head mounting structure, wherein the arm portion serves as a contact portion against which the mounting position adjustment jig or screw comes into contact when adjusting the position of the magnetic head in the rotational direction of the rotating drum.