JP3341823B2 - Magnetic recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus, and more particularly to a structure for mounting a drum base supporting a fixed drum and a rotating drum to a chassis.

[0002]

2. Description of the Related Art FIG. 3 is a schematic side view showing an example of a rotary head drum device used in a conventional VTR.
FIG. 4 is a plan view of the drum base 2 as viewed from the chassis 9 side. The rotary head drum device 1 has a drum base 2 fixedly mounted on a chassis 9 of a VTR.
It has a schematic configuration in which the drum assembly 3 is provided.

The drum assembly 3 includes a rotating drum 4 mounted on a rotating shaft (not shown) and a fixed drum coaxially disposed below the rotating drum 4 with the rotating shaft rotatably supported. 5 and a motor unit (not shown) provided above the rotary drum 4.

On the outer peripheral surface of the fixed drum 5, a lead 7 for regulating the lower edge of the magnetic tape T and guiding its travel is formed as a step. Then, the magnetic tape T is obliquely wound over the outer peripheral surfaces of the rotary drum 4 and the fixed drum 5 under the control of the leads 7, and in this state, the magnetic tape T is driven by tape driving means (not shown) to travel. I have.

A magnetic head 8 is integrally fixed to the rotating drum 4 on the lower surface facing the fixed drum 5.
The tip of the magnetic head 8 projects slightly outside the rotary drum 4.

On the other hand, the drum assembly 3 and the drum base 2 are fixed by positioning bosses 2 formed on the drum base 2.
a is inserted into a hole (not shown) provided on the bottom surface of the fixed drum 5 to perform positioning, and the bottom surface of the fixed drum 5 is brought into contact with the seating surface 2 b of the drum base 2. Of the fixed drum 5 through a through hole 2c provided at the center of the fixing drum 5.

The aluminum die-cast drum base 2 has three through holes 2d, 2e, 2f as mounting holes.
Are formed, and three bosses 2d-1 to 2d-3 and 2e-1 are provided around these through holes 2d, 2e and 2f, respectively.
To 2e-3, 2f-1 to 2f-3. And
These bosses 2d-1 to 2d-3, 2e-1 to 2e-3, 2f-1
2f-3 are in contact with the chassis 9.
Further, a through hole 2g and a through hole 2h are formed in the drum base 2 for positioning the drum base 2 with respect to the chassis 9.

Then, the chassis 9 of the drum base 2
The bosses 2d-1 to 2d-3, 2e-1 to 2e-3, and 2f-1 to 2 are fitted to the positioning pins (not shown) provided on the chassis with the through holes 2g and 2h.
f-3 is brought into contact with the chassis 9 and screwed into the tap holes (not shown) formed in the chassis corresponding to the through holes 2d, 2e and 2f of the drum base 2 through the through holes 2d, 2e and 2f. Will be Reference numerals 10 and 11 denote positioning portions of a tape loading means (not shown) for pulling out the magnetic tape T from a tape cassette (not shown) and winding it around the drum assembly 3 over a predetermined angle range.

In the rotary head drum device 1, the rotary drum 4 rotates in the direction of arrow A in FIG. 3, and the magnetic tape T runs in the direction of arrow B in FIG. Further, when the rotating drum 4 rotates, the tip of the magnetic head 8 comes into sliding contact with the running magnetic tape T wound around the outer peripheral surfaces of the rotating drum 4 and the fixed drum 5, thereby recording or reproducing. Is obtained.

[0010]

However, in the rotary head drum device of the above-mentioned conventional VTR, the bosses 2d-1 to 2d-3, 2e which come into contact with the chassis 9 are attached to the drum base 2 made of aluminum die-casting. -1 to 2e-3, 2f-1 to
Since 2f-3 is formed around three through holes 2d, 2e, and 2f, respectively, the surface is determined by the bosses 2d-1 to 2d-3 and the bosses 2e-1 to 2e-3. 3f of the surface determined by the bosses 2f-1 to 2f-3
It is difficult to precisely form two surfaces on the same plane without additional processing. Therefore, by attaching the drum base 2 to the chassis 9, the chassis 9 and the drum base 2
Will act on both.

Further, tentatively, these bosses 2d-1 to 2d-3,
Even if additional processing is performed on 2e-1 to 2e-3 and 2f-1 to 2f-3 so that all bosses form the same plane, if the flatness of the chassis 9 is not sufficient, the chassis 9 When the drum base 2 is attached to the, the stress acts on both.

This stress causes deformation of the drum base 2. This deformation is caused by the shape of the drum base 2 and especially the positioning portion 10 of the tape loading means.
It is easy to occur near 11. If deformation occurs near the positioning portions 10 and 11 of the tape loading means, the positioning of the tape loading means is not performed correctly,
The traveling path of the magnetic tape T deviates from the original path, and as a result, the magnetic head 8 with respect to the magnetic tape T
Or the magnetic head 8 has a magnetic tape T
However, there is a problem that the linearity of the track pattern to be formed deteriorates, and normal recording or reproduction cannot be performed.

In the above-described conventional example, the case where the positioning portions 10 and 11 of the tape loading means are integrally formed on the drum base 2 has been described. However, the positioning portions 10 and 11 are formed separately. Even in this case, the deformation of the drum base 2 affects the height accuracy of the seating surface 2b and the like, and thus affects the position accuracy of the drum assembly 3 and may cause a similar problem.

[0014]

Means for Solving the Problems The present invention has been made in view of the above problems, and the invention according to claim 1 comprises a "chassis, a drum base fixed to the chassis, and a drum base. In a magnetic recording / reproducing apparatus having a fixed drum fixed and a rotating drum mounted with a magnetic head and rotating coaxially with the fixed drum, a magnetic recording / reproducing apparatus provided on the drum base for fastening and fixing the drum base to the chassis. First, second, and third three fastening holes that are not collinear,
A convex portion formed on the drum base and in contact with the chassis to define the height of the drum base with respect to the chassis, on a first straight line connecting the first and second fastening holes; A convex portion having a dimension in a direction orthogonal to the first straight line smaller than a diameter of the first fastening hole provided on both sides of the first fastening hole; and the first and second fastening holes. And a convex portion having a dimension in a direction orthogonal to the first straight line smaller than a diameter of the second fastening hole provided on both sides of the second fastening hole on a first straight line connecting the first and second fastening holes. A magnetic recording / reproducing apparatus characterized by the above-mentioned. "

According to a second aspect of the present invention, there is provided an electronic apparatus comprising: a convex portion which is formed on the drum base and abuts on the chassis to define the height of the drum base with respect to the chassis; The third fastening holes provided on both sides of the third fastening hole on a second straight line parallel to the first straight line passing through the third fastening hole.
2. A projecting portion having a smaller dimension in a direction perpendicular to the second straight line than a diameter of the fastening hole of the above.
The magnetic recording and reproducing apparatus according to claim 1. "

According to a third aspect of the present invention, there is provided a magnetic recording / reproducing apparatus according to the first or second aspect, wherein the convex portion is a cylindrical boss.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic recording / reproducing apparatus according to an embodiment of the present invention will be described below with reference to FIGS. Parts corresponding to the configuration of the rotary head drum device of the conventional VTR described above are denoted by the same reference numerals. FIG. 1 is a schematic side view showing an example of a rotary head drum device used in the VTR of the present invention. FIG. 2 is a plan view of the drum base 2 as viewed from the chassis 9 side. This rotary head drum device 1 has a schematic configuration in which a drum assembly 3 is disposed on a drum base 2 fixedly mounted on a chassis 9 similarly to the above-described conventional VTR.

The configuration of the rotating drum 4 and the fixed drum 5, the manner of mounting the drum assembly 3 to the drum base 2, and the like are the same as those of the conventional VTR described above. Drum base 2 used in magnetic recording / reproducing apparatus according to the present embodiment
Has three through holes 2d, 2e and 2f formed as mounting holes, and two columnar bosses 2d-1 and 2d-2 on both sides of the through hole 2d, and on both sides of the through hole 2e. Are formed with two cylindrical bosses 2e-1 and 2e-2, and two ribs 2f-1 and 2f-2 on both sides of the through hole 2f.

The bosses 2d-1 on both sides of the through hole 2d,
Both the bosses 2e-1 and 2e-2 on both sides of the through hole 2e and 2d-2 are disposed on a straight line L1 connecting the center of the through hole 2d and the center of the through hole 2e. The ribs 2f-1 and 2f-2 on both sides of the through hole 2f are straight lines L1 passing through the center of the through hole 2f.
Are arranged on a straight line L2 parallel to. The diameters of the bosses 2d-1, 2d-2, 2e-1, and 2e-2 are smaller than the diameters of the through holes 2d and 2e, and the ribs 2f-1 and 2f-2 are also shown in FIG. 2, the dimension in the direction orthogonal to the straight line L1 or the straight line L2 is smaller than the diameter of the through hole 2f.

The chassis 9 of the drum base 2
For mounting to the boss 2d-1, 2d-2, 2e-1, 2e-2 and the rib 2f, the through-hole 2g and the through-hole 2h are fitted to a positioning pin (not shown) provided on the chassis.
-1 and 2f-2 are brought into contact with the chassis 9 and screwed into the tap holes (not shown) formed in the chassis corresponding to the through holes 2d, 2e and 2f of the drum base 2 via the through holes 2d, 2e and 2f. It is done.

As described above, according to the magnetic recording / reproducing apparatus of this embodiment, the bosses 2d-1, 2d-2, 2e-1, 2e-1 provided on both sides of the through hole 2d and the through hole 2e, respectively. Two
Are arranged on the same straight line L1. For this reason, when it is attached to the chassis 9, it is possible to give a degree of freedom of rotation around the straight line L <b> 1, so that even if the flatness of the chassis 9 is poor, excessive stress occurs on the drum base 2 and the chassis 9. Through hole 2d without
The drum base 2 can be attached to the chassis 9 via 2e and 2f. As a result, distortion of the drum base 2 can be reduced, and a magnetic recording / reproducing apparatus having a good head contact with the magnetic tape T and a good track pattern can be realized.

Also, during this mounting operation, the through holes 2
It is desirable that screws d and 2e be screwed first, and then the through hole 2f be screwed. Thereby, distortion generated in the drum base 2 can be further reduced as compared with the case where the through hole 2f is screwed first. In the embodiment described here, the bosses 2d-1, 2d-2, 2e-1, 2e-2.
Described the case where the shape is cylindrical,
It is not limited to this. For example, a thin rib may be formed on the straight line L1.

[0023]

As described above, according to the magnetic recording / reproducing apparatus of the present invention, the chassis, the drum base fixed to the chassis, the fixed drum fixed to the drum base, and the magnetic head are mounted. A magnetic drum having a fixed drum and a rotating drum that rotates coaxially;
First, second, and third non-colinear lines for fastening and fixing the drum base provided on the drum base to the chassis.
And three convex holes formed in the drum base and abutting against the chassis to define the height of the drum base with respect to the chassis. A projecting portion having a dimension in a direction perpendicular to the first straight line smaller than a diameter of the first fastening hole provided on both sides of the first fastening hole on a first straight line to be connected; ,
On a first straight line connecting the second fastening holes, a protrusion whose dimension in a direction perpendicular to the first straight line is smaller than a diameter of the second fastening holes provided on both sides of the second fastening holes. Because it was configured with a

When the drum base is attached to the chassis, it is possible to give a degree of freedom of rotation around the first straight line, so to speak, even if the flatness of the chassis is poor.
The drum base can be attached to the chassis through the three fastening holes without causing excessive stress on the drum base and the chassis. As a result, it is possible to suppress the distortion of the drum base, and to achieve a magnetic recording / reproducing apparatus having a good head contact with the magnetic tape and a good track pattern.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing an example of a rotary head drum device used in a VTR of the present invention.

FIG. 2 is a plan view of the drum base 2 of FIG. 1 as viewed from a chassis 9 side.

FIG. 3 is a schematic side view showing an example of a rotary head drum device used in a conventional VTR.

FIG. 4 is a plan view of the drum base 2 of FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 rotary head drum device 2 drum base 3 drum assembly 4 rotary drum 5 fixed drum 7 lead 8 magnetic head 9 chassis 10 positioning unit 11 positioning unit

Continuation of front page (56) References JP-A-2-18709 (JP, A) JP-A-1-248351 (JP, A) JP-A-63-96695 (JP, U) (58) Fields investigated (Int) .Cl. ⁷ , DB name) G11B 15/61 G11B 33/12

Claims (3)

(57) [Claims] 1. A magnetic recording / reproducing apparatus comprising: a chassis; a drum base fixed to the chassis; a fixed drum fixed to the drum base; and a rotating drum mounted with a magnetic head and rotating coaxially with the fixed drum. In the apparatus, first, second and third three fastening holes which are not formed on the same straight line for fastening and fixing the drum base to the chassis provided in the drum base; A convex portion which abuts on a chassis and defines the height of the drum base with respect to the chassis, and on both sides of the first fastening hole on a first straight line connecting the first and second fastening holes; On a first straight line connecting the first and second fastening holes with a convex portion having a smaller dimension in a direction orthogonal to the first straight line than the diameter of the first fastening hole provided in each of the first and second fastening holes. On each side of the second fastening hole Magnetic recording and reproducing apparatus characterized by dimension than the diameter of the second fastening holes provided perpendicular to the straight line of the first is provided with a small convex portion. 2. A projecting portion formed on the drum base and abutting on the chassis to define a height of the drum base with respect to the chassis, the first portion passing through the third fastening hole.
On a second straight line parallel to the straight line of the above, a convex portion having a dimension in a direction perpendicular to the second straight line smaller than the diameter of the third fastening hole provided on both sides of the third fastening hole, respectively. The magnetic recording / reproducing apparatus according to claim 1, wherein the magnetic recording / reproducing apparatus is provided. 3. The magnetic recording / reproducing apparatus according to claim 1, wherein the convex portion is a cylindrical boss.