JPH0521694Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Field of industrial application] This invention relates to the structure of a rotating head drum for recording diagonally on magnetic tape, such as in VTRs and DATs (digital audio tape recorders). .

[Conventional technology]

4a and 4b show a conventional rotary head drum 1, in which a magnetic head 2 is attached to a rotary disk 3 with a shim 4 and a screw 5. magnetic head 2
A magnetic head chip 7 constituting a magnetic path for performing magnetic recording and reproduction is adhered to a base 6 made of ceramic or the like, a coil 8 wound to interlink with the magnetic path, and a coil 8 for supplying or extracting signals. It is composed of terminals 9 at two locations.

The rotating disk 3 is provided with a fitting hole 10, a threaded portion 11, etc. for coupling with a rotating shaft for rotationally driving the rotating disk 3. Although not shown, the rotary drum 1 is provided with a rotary transformer for supplying and extracting signals to the terminal 9, but this is omitted as it is not particularly necessary for explaining the present invention.

The magnetic head chip 7 has a gap portion 12 for magnetic recording and reproduction, and this portion must be attached to the rotating drum 1 in an accurate positional relationship.

Taking DAT as an example, the diameter of rotating disk 3 is 30
mm, and the relative positional relationship of the gap portions 12 of the two magnetic heads 2 attached to this is within the same rotation plane and at positions opposite to each other at 180 degrees, and the tolerance for the attachment is in the direction of the rotation axis. Z, protrusion direction Y, and tangential direction X (see FIG. 4b) are all within several μm. On the other hand, since the relative position of the gap 12 with respect to the mounting surface of the magnetic head 2 is not constant for each magnetic head, shims of different thickness are used for each of the two magnetic heads 2 attached to one rotating disk 3 in order to align the rotating surfaces. You need to select 4. Adjustments in the protrusion direction and tangential direction are made by sliding the magnetic head 2 on the mounting surface and using a jig equipped with a microscope. However, the rotary head drum having such a structure has the disadvantage that the shim 4 must be selected for each magnetic head, which complicates the assembly process. Furthermore, in the case of a DAT whose rotating head drum has a small diameter of 20 mm or 15 mm, the magnetic head must also be made smaller. However, the sizes of the mounting screws 5 and the base 6 cannot be made extremely small, and it has been difficult to obtain a small rotating head drum.

In order to solve these problems, the inventor of the present invention attached the magnetic head chip directly to the rotary head drum body, and also fixed the chip mounting part of the drum body to which the magnetic head chip was attached by using an elastically deformable thin plate. An improved type of rotary head drum has already been developed which has a similar structure and in which the chip mounting portion is displaced by a pressing means such as a push screw.

The structure of this improved rotary head drum will be explained below with reference to FIG. Components that are the same as those in FIG. 4 are given the same reference numerals. The rotary disk 3 is provided with a cut portion 13 parallel to a plane perpendicular to the rotation axis in order to reduce the thickness B of the portion where the magnetic head chip 7 is attached to form an elastically deformable thin plate portion 30. ing. In addition, a notch 14 is provided in the vicinity C of the magnetic head chip mounting portion to allow the winding portion of the magnetic head chip 7 to escape.
A terminal 9 for transmitting and receiving signals to and from the coil 8 is also provided. If the rotary disc 3 is made of resin, the terminal 9 can be constructed by directly adhering or embedding a metal part, but if it is made of aluminum, it is attached via an insulating part. Further, a screw hole 15 is provided on the bottom surface of the rotary disk 3 on which the head is attached and on a line that intersects the magnetic head attachment part and the center of the disk, and the screw hole 15 is provided on the opposite side to the surface on which the magnetic head chip 7 is attached. A set screw 16 is screwed in from the surface. This screw hole 15 is located on the line connecting the two magnetic head tips 7 and the center of the rotating disk 3, and in the direction of the center.
It is provided outside the innermost part D of 3.

FIG. 3 shows an enlarged view of the magnetic head chip 7 and the vicinity of the mounting portion C. c in the same figure is c-c in the same figure a
It is a figure showing a line cross section. Figure c is c- in figure a.
A cross-section is shown. The magnetic head chip 7 has a core 1 made of a magnetic material such as sendust or ferride.
7 and 18 constitute a ring-shaped magnetic path, and a gap portion 12 is provided in a part of the magnetic path. The width of the gap affects magnetic recording, and is usually called the track width 19. Track width 19 is made of magnetic material 1
7 and 18 due to the cutout portion 20, this is done to improve the efficiency of the magnetic path. Although the notch 20 may be a space, it is often made of a non-magnetic material such as glass. The magnetic head chip 7 constructed in this manner is fixed to the rotating disk 3 with an adhesive 21.

Next, the effects will be explained.

Here, as explained in the conventional example, the gap 12 needs to be mounted with an accuracy of several μm in the rotation axis direction Z, the protrusion direction Y, and the tangential direction X.
In the improved rotary head drum, accuracy in the protrusion direction and the tangential direction is obtained by positioning the magnetic head chip 7 on the mounting surface using a jig and then fixing it with the adhesive 21, as in the prior art. However, the position of the rotating surface is different from that of the magnetic head chip 7.
Since the position of the gap portion 12 relative to the mounting end 22 of the magnetic head chip varies from magnetic head chip to magnetic head chip, its accuracy cannot be ensured.

Therefore, in the above-mentioned improved rotary head drum, by rotating the push screw 16 as shown in FIG. The rotation surfaces of the gap 12 can be aligned.

Furthermore, since the magnetic head chip 7 is directly bonded to the rotating head drum, no shims or mounting screws are required, and an inexpensive product can be obtained.

[Problem that the invention attempts to solve]

However, in the improved rotary head drum 1 having such a configuration, in order to make the mounting portion of the rotary disk 3 for the magnetic head chip 7 elastically deformable, the cut portion 1 is formed over the entire outer circumference of the rotary disk 3.
3, and therefore the notch 13
This has a problem in that it has a large effect on the magnetic tape wound around the rotating disk 3, leading to deterioration of the magnetic tape.

This idea was made to solve the above problems, and it is possible to adjust the height position of the magnetic head tip while minimizing the negative effect on the magnetic tape, and it is easy to process. The purpose is to obtain a rotating head drum structure.

[Means for solving problems]

The rotary head drum according to this invention has a substantially semi-circular arc cut cut from the outer circumferential side toward the center on the lower side of the chip mounting part where the magnetic head chips are attached to the thick rotary head drum body, so that the chip mounting part can be elastically deformed. The magnetic head chip has a thin plate-like structure, and the thin plate-like chip mounting portion is pressed and deformed to adjust the vertical position of the magnetic head chip.

[Effect]

In this invention, the mounting part of the magnetic head chip has an elastically deformable structure, and is deformed by a pressing means such as a screw to adjust the vertical position of the magnetic head chip. This simplifies the assembly process. In addition, an approximately semi-circular cut is made on the lower side of the tip attachment part of the rotary head drum body, and the tip attachment part is made into a thin plate-like structure that can be elastically deformed, so that the tip attachment part can be moved. The rotary head drum can be realized by a simple processing operation of just making a notch in the side surface of the rotary head drum main body. In addition, since the notch formed on the rotary head drum body is approximately semicircular, the length of the groove formed on the side surface of the rotary head drum body by the notch is small, and the influence of the notch on the magnetic tape is small. can be kept small.

〔Example〕

An embodiment of this invention will be described below with reference to the drawings.

FIG. 1 is a diagram for explaining a rotary head drum according to an embodiment of the present invention, in which FIG. 1a is a front view, FIG. 1b is a plan view, and FIG. It is a sectional view taken along the c line.

In the figure, reference numeral 100 denotes the rotary head drum of this embodiment, which has a substantially semicircular arc-shaped cut 13' extending from the outer circumferential side toward the center on the lower side of the chip attachment part 40 to which the magnetic head chip 7 is attached to the thick rotary disk 3. The chip mounting part 40 is made into a thin plate-like structure that can be elastically deformed, and the thin plate-shaped chip mounting part 40 is pressed and deformed by a push screw 16 to adjust the vertical position of the magnetic head chip 7. This is what I did. Further, the magnetic head chip 7 is placed on a chip mounting surface 40a that is level with the bottom surface of the rotary disk 3 and has a step approximately equal to the thickness of the magnetic head chip 7. The rest of the structure is the same as the conventional rotary head drum 1 shown in FIGS. 2 and 3 above.

In the rotary head drum 100 of this embodiment having such a structure, the chip mounting portion 40 has an elastically deformable thin plate structure, and the thin plate-shaped chip mounting portion 7 is pressed and deformed by the push screw 16 to attach the magnetic head chip. Since the vertical position of the magnetic head chip 7 is adjusted, the positioning work of the magnetic head chip 7 is simplified, and the assembly process can be simplified.

In addition, a substantially semicircular arc-shaped cut 13' is made on the lower side of the tip attachment part of the rotating disk 3, and the tip attachment part 40 is made into a thin plate-like structure that can be elastically deformed.
A rotary head drum 100 having a structure in which the chip mounting portion 7 is movable can be realized by a simple processing operation of making a notch in the side surface of the rotary disk 3. Further, since the notch 13' formed on the side surface of the rotary disk 3 has a substantially semicircular arc shape, the length of the groove formed on the side surface of the rotary disk 3 due to the notch is small.
3' on the magnetic tape can be suppressed to a small level.

[Effect of idea]

As described above, according to this invention, the mounting part of the magnetic head chip has a structure that can be elastically deformed, and this is deformed by a pressing means such as a screw to adjust the vertical position of the magnetic head chip. This has the effect of simplifying the head chip positioning work and simplifying the assembly process.

In addition, an approximately semicircular cut is made on the lower side of the tip attachment portion of the rotating head drum body, and the tip attachment portion is made into a thin plate-like structure that can be elastically deformed.
There is an effect that a rotary head drum having a structure in which the chip mounting portion can be displaced can be realized by a simple processing operation of just making a notch in the side surface of the rotary head drum main body.

Furthermore, since the notch formed on the rotary head drum body has a substantially semicircular arc shape, the length of the groove formed on the side surface of the rotary head drum body due to the notch is small, and the influence of the notch portion on the magnetic tape is small. This has the effect of keeping it small.

[Brief explanation of drawings]

Fig. 1a is a front view showing a rotating head drum according to an embodiment of the present invention, Fig. 1c is a partial sectional view thereof, Fig. 1b is a plan view thereof, and Fig. 2a is a conventional improved rotary head drum. Front view showing the head drum, Figure 1b
3 is a plan view thereof, FIG. 3 a is an enlarged front view showing the vicinity of the magnetic head chip mounting portion of the above-mentioned improved rotary head drum, FIG. 3 b is a plan view thereof, and FIG. 3 c is the c of FIG. -c line sectional view; Figure 4a is a front view showing a conventional rotating head drum;
Figure b is a plan view thereof. 3...Rotating disk, 7...Magnetic head chip, 1
2...gap, 13'...approximately semicircular arc-shaped notch,
14...Notch, 15...Screw hole, 16...
Push screw, 40...Magnetic head chip mounting part, 4
0a... Magnetic head chip mounting surface, 100... Rotating head drum. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Scope of Claim for Utility Model Registration] In a rotating head drum that forms tracks diagonally on a magnetic tape, a thin plate-shaped portion is provided by cutting a thick rotating head drum body into a substantially semicircular arc shape from the side surface in a direction perpendicular to the rotation axis. , a magnetic head chip provided by directly adhering to the thin plate-like portion; and a pressing means for pressing and deforming the thin plate-like portion to adjust the vertical position of the magnetic head chip. Rotating head drum.