JPS59185018A - Tape recorder - Google Patents

Abstract

PURPOSE:To miniaturize the device by using a driving means coupled with a head reversing changeover gear to regulate the center of a head rotary shaft and keeping a head face parallel with a tape by a thrust plate spring and turning the head face thereby preventing the generation of slipping of track and reducing the shock at head changeover. CONSTITUTION:The head reversing changeover gear 46 is turned by a driving gear. A head rotary bearing plate 48 supports a rotating support shaft 45. Since a head mount 32 is pressed to a flat part 33b of a head base 33 in parallel with a tape face by a pressing force of the thrust plate spring 47 even if an external force shown in the arrow is applied to a magnetic head 31 or there exists a slight clearance between the rotary support shaft 45 and a bearing part 48a, the head face is kept in parallel with the tape face at all times. Since the bearing part has a clearance and there is no tilt amount in the head front face, the track offset more than the amount of clearance is not produced. Further, the contact area of the bearing part is very small, then the turning resistance is small, thus the spring pressure energizing the head mount 32 is made very small and the shock when a turning stopper abuts on azimuth adjusting screws 34, 35 is decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a tape recorder equipped with a magnetic head device capable of changing the track position of a magnetic tape, and in particular, the present invention relates to a tape recorder equipped with a magnetic head device capable of changing the track position of a magnetic tape. The present invention relates to a tape recorder capable of reciprocating recording and playback in which switching is performed by rotating the magnetic throat.

Conventional Structures and Problems Recently, a tape recorder capable of reciprocating recording and playback, which switches the track position of a magnetic tape by rotating a magnetic head, has been proposed. This technique is being adopted, particularly in cassette tape recorders, with the aim of reducing wow and flutter by reducing the load of running the magnetic tape, and improving mechanical accuracy. The tape recorder shown in Fig. 1 is applied to the above-mentioned cassette type tape recorder.
) is a top view, (b) is a front view, and (C) is a right side view. In this embodiment, a head mount 12 on which a magnetic head 11 having a two-channel (track) magnetic core is mounted and fixed is pivotally supported on a head rotation shaft 18, and
A driven gear 19 for rotating the head is meshed with driving means (not shown) such as driving teeth pivotally attached to a motor, and the head rotation shaft 18 is meshed and fixed in a center hole of the driven gear 19.

Further, the head mount 12 is integrally provided with a rotary arm 12a, and the rotary arm 12a is configured to be rotatable together with the head rotation shaft 18. By rotating the drive means in conjunction with the track position switching operation, the head rotating shaft 18 is rotated and the magnetic head 11 is rotated 180 degrees. The head rotation shaft support base 13 that supports the head rotation shaft 18 is fixed to a hendo slide plate (not shown), and has azimuth adjustment screws 14 at both ends thereof via springs 16 and 17.
．． i5 is provided, and the position of the rotary arm 12a is regulated by adjustment screws 14 and 15, respectively, in the normal rotation direction 2.
Azimuth adjustment in the reverse direction is possible. In the above example, by rotating the azimuth adjustment screws 14 and 15, an attempt is made to obtain the best angle of contact between the tape and the magnetic head, the so-called azimuth angle, and by rotating the magnetic head 180 degrees, reciprocating recording and playback is possible. This has the advantage that the operation of reversing the tape cassette can be omitted.

By the way, conventionally, a head mount is provided at the rear end of such a magnetic head, this head mount is pivotally supported by a head rotation shaft, and a driven gear is supported at the other end of the head rotation shaft.
The configuration for rotating the magnetic head inevitably has a large depth dimension as shown in Figure 1 (C), and the structure that rotates the magnetic head is inevitably large in depth, and is not suitable for use with recent small cassette decks or thin cassette decks (4). have.

On the other hand, in order to eliminate this drawback, a tape recorder having a magnetic head device shown in FIG. 2 is known. 21 is a magnetic head for recording and reproducing, and 22 is a head mount that accommodates the magnetic head 21 approximately in the center. This henodo mount I/22 has a flange 22a and is cylindrical in shape, and a head base 23 rotatably holds the outer periphery of the head mount 22 in the role of a bearing. 29 is Ujif
A driven gear is integrally attached to the other end of the head mount 22, and rotates clockwise or counterclockwise in accordance with the rotation of the driving wheels (not shown) to switch the magnetic head between normal rotation and reverse rotation. 24 and 2'5 are a pair of azimuth adjustment screws screwed into the head mount 22 via springs 26 and 27, as in the conventional example shown in FIG. 22a comes into contact with the head mount 22 to restrict the rotational position of the head mount 22.

28 is the rotation center of the head mount 22 and the magnetic head 21
Determine the relative position of the magnetic head 2 on the head mount 22.
This is a spacer for adjustment when fixing 1 with adhesive.

The second conventional example configured as above is shown in FIG. 2(C).
As shown in FIG. 2, since the head base 23 is also used as a bearing for the head mount 22, there is an advantage that the distance from the front surface of the magnetic head to the magnetic gutter rotation mechanism is shortened. However, in this configuration, since the outer periphery of the head mount 22 is supported by the head base 23, there is a drawback that rotational resistance is large. When storing and fixing a magnetic head in the Amada head mount 22, in order to adjust the relative position between the rotation center of the head mount 22 and the magnetic head, the mounting dimensions are adjusted in stages using several types of spacers with different thicknesses. It required adjustment and was very time consuming to assemble.

Furthermore, the above-mentioned first conventional example and second conventional example, for example l! lb
If there is even a slight clearance in the receiving part, the head mount will tilt, causing the magnetic head to tilt up, which will have a negative effect on tape running. Historically, there have been drawbacks such as track misalignment on the front of the magnetic head. .

OBJECTS OF THE INVENTION The first object of the present invention is to realize a compact and thin tape recorder by reducing the required distance from the front surface of the magnetic head to the rear end. To provide a tape recorder which does not cause any interference or trunk displacement, and which makes it possible to minimize the impact generated when switching magnetic heads by minimizing the rotational resistance of the head mount. This is the purpose.

Structure of the Invention The present invention comprises a circular head mount housing a magnetic head, a head rotation shaft fixed at the center of the axis of the head mount, and a head reversal switching gear that rotates coaxially with the hennode rotation shaft. a head rotation support bearing member for pivotally supporting the head rotation shaft; a head base having a flat surface parallel to the tape surface; The head rotation shaft is rotated with its center of rotation being regulated by the head rotation support bearing member by a driving means which is equipped with a thrust plate spring that applies pressure and is meshed with the henode reversal switching gear, and the head base is rotated by the thrust plate spring. By being pressed against a plane parallel to the tape surface, the disk on the head mount is rotated while remaining parallel to the tape, so there is no risk of track misalignment, there is little rotational resistance on the head mount, and the head mount is compact. This makes it possible to realize a thin tape recorder.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Figure 3 (a), (b), (cl is a top view, front view, right side view, and fourth figure showing an example of unexploded t9J, respectively)
The figure is an exploded view. 31 is a magnetic head for recording and playback; 3
Reference numeral 2 denotes a head mount in which a magnetic head 31 is housed approximately in the center. 33 is a head base, which is usually attached to the head substrate. The head base 33 has an opening 3 so that the head mount 32 is exposed on the tape surface side.
3a is provided, and further a flat part 33b parallel to the tape surface.
is formed inside.

45 is a gutter rotation support shaft, and this head rotation support shaft 45
is mounted at the center of a head mount 32 or a head rotation table 44 attached with adjustment screws 38 and 39. The height 1 adjustment screws 38 and 39 can be tightened after finely adjusting the relative position of the center of the rotating support shaft 45 and the magnetic head 31 using the convex portions 44d and 44e and the concave portions 32b and 32c as guides. ing. Reference numeral 46 denotes a head reversal switching gear press-fitted into the head rotation support shaft 45, and is adapted to rotate clockwise or counterclockwise by transmission of rotation from a drive gear (not shown). Reference numeral 48 denotes a head rotation support bearing plate, and the bearing portion 4 supports the head rotation support shaft 45.
8ai, and is fixed to the head base 33 with mounting screws 49.50 so that the rotational center position of the head rotation support shaft 45 can be adjusted in the vertical direction (height direction of the head). Reference numeral 47 denotes a thrust plate that presses the spherical end surface of the head rotation support shaft 45 toward the tape surface side with a thrust force (P) in the thrust direction. The pressing force of this thrust plate spring 47 (
P) causes the collar portion 32a of the head mount 32 to be strongly pressed against the flat portion 33b of the head base 33 parallel to the tape surface via the plurality of steel balls 42. Therefore, the front surface of the magnetic head 31 is completely parallel to the tape surface.

Reference numerals 34 and 35 designate an azimuth adjustment screw that is adjustable on the head base 33 via the unmass adjustment springs 36 and 3γ, and is a rotation stopper 44a that is integrated with the head rotation table 44.

The azimuth is determined by contacting 44b or this.

This is a ring-shaped ball seat made of stainless steel that can accept steel balls.

Also, the lead wire of the magnetic head 31 is connected to the rotary table 4.
By winding the lead wire through the hole 44c provided in the head rotation table 44 and the groove between the head rotation table 44 and the head reversal switching gear, twisting of the lead wire when the head is rotated is prevented.

With the above configuration, even if an external force as shown by the arrow shown in FIG.
Even if there is a slight clearance between the head mount 32 and the bearing part 48a, the pressing force (P) of the thrust plate 47 always moves the head mount 32 to the flat part 33b of the inner surface of the head base 33, which is formed parallel to the tape surface. As a result of pressing, the head mount 32, that is, the head surface is always kept parallel to the tape surface. Even if there is a slight track deviation on the front surface of the head, since there is a clearance in the bearing section and no tilting occurs on the front surface of the head, a track deviation larger than the amount of clearance will not occur. In addition, the contact M (area of the bearing part is very small, and by using steel balls on the other side, it has a similar configuration to a thrust ball bearing, so the rotational resistance is small. Therefore, the head mount can be placed on the normal rotation side
Since the spring pressure applied to the reverse side can be reduced, the impact when hitting the rotation stopper or azimuth adjustment screw can be reduced, preventing azimuth shift due to impact, and preventing the generation of impact noise.

Note that FIG. 5 is a top view showing a state in which the center of the rotation countershaft 45 and the relative position of the magnetic head 31 are shifted by the maximum amount by the adjustment screws 38 and 39.

DETAILED DESCRIPTION OF THE INVENTION As described above, the present invention includes a disk-shaped head mount housing a magnetic head, a head rotation shaft fixed at the center of the axis of the head mount, and a head reversal switch that rotates coaxially with the head rotation shaft. a gear, a head rotation support bearing plate that pivotally supports the head rotation shaft, a head base having a flat surface parallel to the tape surface, and an axial pressure applied to the head mount to press it against the flat surface of the head base. A driving means is provided with a thrust plate spring that provides a thrust plate spring, and is engaged with the head reversal switching gear, so that the head rotation shaft is rotated with the rotation center position being set in the same position as the 'tall socket of the head rotation support bearing member. , the end face of this head rotation axis is pressed against the tape surface side by the pressing force of the temporary thrust spring.For example, the head mount is pressed against the flat part of the head base parallel to the tape surface, and the tape is parallel to the tape surface. Since it is configured to rotate while
It is possible to reduce the distance from the front surface of the magnetic head to the rear end dimension, and furthermore, there is no bumping up or track misalignment between the tape and the front surface of the magnetic head, and the rotational resistance of the head mount is minimized. Therefore, it is possible to provide a magnetic head device which makes it possible to reduce the shock generated when switching the magnetic head, and an excellent tape recorder.

[Brief explanation of the drawing]

Figure 1 shows the main parts of a conventional tape recorder.
) is a top view, (b) is a front view, (C) is a right side view, and Figure 2 is another conventional example, (a) is a top view, (b) is a front view, and (C) is a right side view. Figures 3 and 3 show essential parts of an embodiment of the tape recorder of the present invention, (a) is a top view, (b)
) is a front view, (c) is a right side view, FIG. 4 is an exploded view of this embodiment, and FIG. 5 is a top view showing an adjusted state. 31...Magnetic head, 32...Head mount, 33...Head base, 44, Mountain/Head rotation 7-Bunope 45... Head rotation support shaft, 46...
Head reversal switching gear, 47... Thrust plate,
48...Head rotation support plate. Name of agent Patent attorney Toshio Nakao and 1 other person/γ (S11 Figure 4 3 Shinhe s7

Claims (1)

[Claims] a disk-shaped head mount that accommodates a magnetic head; a head rotation shaft fixed at the axial center of the head mount;
A head reversal switching gear that rotates coaxially with the head rotation axis, a head rotation support bearing member that pivotally supports the head rotation axis, a head base provided with a flat portion parallel to the tape surface, and a head mount that is attached to the head base. The head rotation shaft is rotated by the drive means, which is equipped with a thrust plate spring that applies pressure in the axial direction to press against a flat surface parallel to the tape surface, and which is meshed and coupled to the head reversal switching gear, so that the head rotation shaft is rotated by the henode rotation support bearing member. A tape recorder characterized in that the disk of the head mount rotates while keeping the center regulated and parallel to the tape surface by being pressed against a plane parallel to the tape surface of the head base by a thrust plate spring.