JPS6349861Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a head mounting device suitable for use in mounting a head on a rotating drum of a VTR.

BACKGROUND TECHNOLOGY AND PROBLEMS As is well known, in a helical scan type VTR, two video heads (hereinafter simply referred to as heads) are mounted on the peripheral edge of a rotating drum so as to face each other by approximately 180 degrees. The mounting position of these heads is
This requires extremely high precision. For this reason, normally, the head is once attached to the drum and then various positional adjustments are made to achieve the precision of the attachment position. These positional adjustments include angle division adjustment, azimuth adjustment, pairing adjustment, and the like.
Generally, the head is glued to a head substrate, and the head substrate is fixed to the drum by screws. The angle division adjustment described above is for adjusting the arrangement interval between two heads to a predetermined angle. The above azimuth adjustment is to adjust the azimuth angle of the head to a predetermined angle with respect to a reference. Furthermore, the above-mentioned pairing adjustment relates to relative height adjustment of the two heads. Among these adjustments, azimuth adjustment is performed when the head is glued to the head board, and angle adjustment and pairing adjustment are performed by screwing the head board to the drum and then adjusting the position of the head board. It will be done. Another important issue is the contact pressure of the head attached to the drum with the tape. That is, if the contact pressure is high, dropouts, jitter, etc. will occur due to head clogging and tape jumping, so the contact pressure must be kept as low as possible.

Conventionally, various types of head mounting devices have been proposed, including the structure of the head board and the above-mentioned adjustment methods. There was nothing that could control protrusion and retraction to safely protect the head. Moreover, with recent high-density recording, track widths and track pitches are becoming smaller and smaller, and for this reason extremely precise head position adjustment of about 1 μm is required.

Purpose of the invention The present invention makes it possible to easily perform the above-mentioned position adjustment when installing multiple heads on a rotating drum, to sufficiently lower the contact pressure of the tape on the heads, and to protect the heads safely. The present invention provides a head mounting device that can be used as a head mounting device.

Summary of the invention The invention consists of two substantially parallel arms 1b and 1c,
a rear part 1c connecting the rear ends of these two arms;
A bridge portion 1a connecting these two arm portions approximately at the center is integrally provided, and the head board 1 whose rear portion is fixed to the drum 13 and the bridge portion 1a are sandwiched between the two arm portions. There are two spring means 6 and 7 attached to the arms, a head 11 is attached to the tip, and a hole 12 is provided approximately in the center, and the spring means are disposed between the two arms. an auxiliary board 10 supported by the drum; and a screw 20 screwed into the bottom of the drum and inserted into the hole of the auxiliary board, the tip of which comes into contact with the bridge portion of the head board, The direction of elasticity of the spring means is substantially parallel to the direction of protrusion and retraction (direction of arrow a) of the head, and the amount of movement of the head in the direction of protrusion and retraction is restricted by the connection between the edge of the hole and the screw. The head mounting device is characterized in that the position adjustment of the head is carried out by adjusting the distances d ₁ and d ₂ and by pressing the bridge portion by screwing in the screw.

Embodiment In FIG. 1, a head substrate 1 has a shape in which a bridge portion 1a is integrally formed with a substantially U-shaped member. Slits 2 and 3 for attaching leaf springs 6 and 7 are formed in one of the two arm parts 1b and 1c of the base plate 1 at positions sandwiching the bridge part 1a. A screw insertion hole 4 is provided approximately in the center of the rear portion 1d of the substrate 1 for screwing the substrate 1 to a drum to be described later. A guide recess 5 into which the auxiliary board 10 is slidably fitted is provided on the lower surface of the center of the bridge portion 1a.

The leaf springs 6 and 7 are made of stainless steel, Be-Cu, rubber,
It is made of a thin plate such as plastic, and has a relatively low spring constant. Slits 8 and 9 for holding the auxiliary board 10 are formed at the tips of these leaf springs 6 and 7.

The auxiliary board 10 has a head 11 with its end protruding by a predetermined amount from the lower end thereof and fixed thereto by adhesive or the like, and a hole 12 into which a pairing adjustment screw (described later) is inserted is provided approximately in the center.

FIGS. 2 and 3 show the above-mentioned members assembled and attached to the rotating drum 13. FIG.

The board 1 is inserted into the drum 13 by screws 15 screwed into the screw holes 14 provided in the drum 13 from the insertion holes 4.
Its rear portion 1d is fixed. This board 1 is
The front portion, excluding the rear portion 1d, is attached to the drum 1 so as to protrude above a recess 16 formed at the peripheral edge of the bottom surface of the drum 1. The leaf springs 6 and 7 have their one ends fitted into the slits 2 and 3, and are further fixed to the substrate 1 with an adhesive. The auxiliary board 10 is held and fixed by the slits 8 and 9 at the tips of these leaf springs 6 and 7. This auxiliary board 10 is fitted into the guide recess 5 so as to be slidable in the direction of arrow a. The head 11 attached to the tip of the auxiliary board 10 protrudes from a window 18 provided in the side wall 17 of the drum 13 by a predetermined amount Δt.

The pairing adjustment screw 20 screwed in from the screw hole 19 provided at the bottom of the drum 13 is inserted through the recess 16 and the hole 12, and its tip is connected to the bridge portion 1.
It is in contact with the central lower surface (upper surface of the guide recess 5) 1e of the guide recess 5. Further, a damper 21 is provided at the front of the board 1 and is in contact with the auxiliary board 10. Further, as shown in FIG. 2, the bottom of the drum 13 is provided with screw holes 22 and 23 into which taper screws for angle division adjustment, which will be described later, are screwed. still,
The drum 13 is a rotating drum that serves as a lower drum in a VTR, and 24 in FIG. 3 indicates a fixed drum that serves as an upper drum.

According to the above configuration, when performing pairing adjustment, by tightening or loosening the screw 20 in the direction of the arrow b in FIG. Since it rotates in the direction of arrow c, the head 11
The height h can be adjusted. Also, when adjusting the angle, as shown in Figure 4,
By adjusting the taper screws 25 and 26 screwed into the screws 2 and 23, the substrate 1 can be rotated in the direction of the arrow d with the screw 15 as a fulcrum in FIGS. 2 and 4. Further, when a tape (not shown) runs on the side wall 17 of the drum 13, the auxiliary board 10 is elastically movable in the direction of the arrow a by the plate springs 6 and 7, so that the tape jumps. etc. can be absorbed, eliminating jitters and dropouts.

In addition, the screw 20 in the hole 12 and the hole 1
The amount of protrusion and retraction of the head 11 in the direction a is regulated by the distances d ₁ and d ₂ from the edge of the head 11 . Therefore, it is possible to prevent the head 11 from protruding excessively due to, for example, a runaway of the servo circuit, or from retracting the head 11 excessively when cleaning the head 11.
can keep you safe. In this case, the head 11 is regulated in the a direction by the contact between the auxiliary board 10 and the screw 20, each of which has rigidity, so that the regulation can be performed reliably. In this case, the above
d ₁ and d ₂ are selected to be approximately 50 to 100 μm, for example. still,
In this embodiment, one end of the leaf springs 6, 7 is supported by one arm 1b of the board 1.
Alternatively, both ends of the substrate 1 may be supported by both arm portions 1b and 1c of the substrate 1.

Effects of the invention When attaching the head to the drum, it is possible to easily perform angle adjustment, pairing adjustment, etc., and the head can be made to protrude a predetermined amount and come into contact with the tape with a sufficiently low contact pressure. .
Furthermore, excessive protrusion and retraction of the head can be prevented. Dropouts, jitter, etc. can be effectively removed, and the life of the head can be extended. In addition, conventionally, the head board 1
There is one in which head pairing is adjusted by pressing the vicinity of the hole 4 in the rear part 1a of the head with a screw and rotating the head board 1 in the direction of arrow c (Fig. 3). Since the vicinity of the rotational fulcrum of the head board 1 is pressed, the amount of screwing in the screw is expanded, which affects the amount of adjustment of the head, making it extremely difficult to achieve precise adjustment accuracy.
In the present invention, since the bridge portion 1a remote from the pivot point is pressed by the screw 20, precise adjustment can be easily performed and an accuracy of about 1 μm can be easily achieved. Furthermore, when adjusting the angle in the direction of arrow d in FIGS. 2 and 4, the press screw 20 is not located at the center in the length direction of the bridge portion 1a, but is adjusted at a position to the left or right in FIG. may be completed. In this case, if screw 20
If it is configured to press the rear part 1c,
Since the fastening force of the fixing screws 15 is large, the reaction force of the pressing screws exerts a torsional moment on the rear portion 1c, causing the entire head board 1 to tilt to the left or right in FIG. 4. If the head substrate 1 is tilted, the azimuth of the head 11 will be out of alignment. In the present invention, since the screw 20 presses the bridging portion 1a that is remote from the rear portion 1c, the influence of the fastening force of the screw 15 is reduced. Therefore, since the reaction force of the screws 20 is small, the head board 1 will not tilt.
For this reason, pairing adjustment will not upset the azimuth.

[Brief explanation of drawings]

Figures 1 to 4 show an embodiment of the present invention. Figure 1 is an exploded perspective view, Figure 2 is an external perspective view, Figure 3 is a side sectional view, and Figure 4 is a state in which the angle is adjusted. FIG. In addition, in the symbols used in the drawings, 1...head board, 1d...bottom surface, 6, 7...plate spring, 10...
... Auxiliary board, 11 ... Head, 12 ... Hole, 13
...Drum, 20...screws.

Claims (1)

[Claims for Utility Model Registration] Two substantially parallel arms, a rear portion that connects the rear ends of these two arms, and a bridge portion that connects the two arms at approximately the center. a head base plate having a rear portion fixed to the drum; two spring means attached to the arm portions so as to sandwich the bridge portion; an auxiliary board that is attached and provided with a hole substantially in the center, is disposed between the two arms and supported by the spring means; and is screwed from the bottom of the drum and inserted into the hole of the auxiliary board. and a screw whose tip abuts against the bridging portion of the head board, the direction of elasticity of the spring means being substantially parallel to the direction of protrusion and retraction of the head, and the protrusion and retraction direction of the head. The amount of movement in the retracting direction is regulated by the distance between the edge of the hole and the screw, and by screwing in the screw, the bridging portion is pressed to adjust the position of the head. A head mounting device characterized by: