JPS639857Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a magnetic head device that is capable of switching the track position of a magnetic tape, and in particular, reciprocating recording and playback in which the track position of a magnetic tape is switched in the forward and reverse directions by rotating the magnetic head. The present invention relates to a magnetic head device for a tape recorder.

Conventionally, the track position of a magnetic tape has been switched when the magnetic tape is driven in the same direction, such as in an 8-track endless playback device or a 4-channel recording/playback device, or in a tape recorder capable of reciprocating recording and playback. There are cases where the magnetic tape is switched between the magnetic tape direction and the reverse direction.As for the means for switching the track position of the magnetic tape, there is a method of switching the magnetic heads using a plurality of magnetic heads with different track arrangements, and a method of switching the magnetic heads using all the required tracks. There may be a method of switching the track connection of the magnetic head using a single magnetic head having a magnetic head, or a method of moving a magnetic head having the minimum number of tracks up and down. The above method is unsuitable for tape recorders capable of reciprocating recording and playback with forward and reverse directions in terms of azimuth adjustment and magnetic head adjustment, and further methods require an increase in the number of magnetic heads, resulting in high costs. In addition, the sliding surface of the magnetic tape increases, which increases the running load of the magnetic tape, leading to deterioration of wow and flutter. It has various drawbacks such as not being able to produce. In order to eliminate such drawbacks, a method is known in which a single magnetic head is used and the magnetic head is rotated each time the track position is changed, as shown in the first article. That is, the tape recorder shown in FIG. 1 is applied to a cassette tape recorder, in which a head support 2 on which a magnetic head 10 having a two-channel (track) magnetic core is mounted and fixed is attached to a head rotating shaft 4. A driven gear 5 for rotating the head is in mesh with a driving means (not shown) such as a driving gear pivotally connected to a motor.
A head rotating shaft 4 is fitted and fixed in the center hole of the head. Further, the head support base 2 is provided with a rotating arm 3, which is configured to be rotatable together with the head rotation shaft 4. By rotating the drive means in conjunction with track position switching, the head rotating shaft 4 is rotated and the magnetic head 10 is rotated 180 degrees. The head rotation shaft support base 6 that supports the head rotation shaft 4 is a head slide plate (not shown).
Azimuth adjustment screws 7a, 7b are provided at both ends via springs.
The position of the rotary arm 3 is regulated by 7b, allowing azimuth adjustment in the forward direction and reverse direction, respectively. By rotating the azimuth adjustment screws 7a and 7b, it is possible to obtain the best contact angle between the tape and the magnetic head, the so-called azimuth angle.

By rotating the magnetic head 180 degrees in this way, it is possible to record and play back from forward to backward or from backward to forward, and the advantage is that the operation of reversing the tape cassette can be omitted, and a normal stereo magnetic head can be used. It has the following.

By the way, the conventional method of rotating the magnetic head by supporting the head support base from the rear end of the magnetic head with a head rotating shaft and supporting a driven gear at the other end of the head rotating shaft is based on the track position. When regulating the position of the magnetic head related to switching, the driving means meshingly connected to the driven gear must always be driven in one direction, requiring mechanical precision of the driving means with respect to the driven gear, and due to its structure. Since the depth dimension, ie, the distance l from the front surface of the magnetic head to the driven gear, is inevitably large, it cannot be applied to recent small cassette decks or thin cassette decks, and has a major drawback.

The present invention was developed in view of these conventional drawbacks, and its purpose is to minimize the depth dimension of this type of magnetic head rotation mechanism and to create a structure without increasing the number of parts unnecessarily. An object of the present invention is to provide a simple magnetic head device capable of stably holding a magnetic head at a predetermined regulated position.

Hereinafter, the present invention will be explained based on examples.

2 to 4 are diagrams showing one embodiment of the present invention. In the figures, 10 is a magnetic head for recording and playback, and 20 is a magnetic head 10 approximately in the center.
It is a head support stand having a cylindrical outer shape with a flange 22 provided at one end, and a driven gear 23 formed approximately 180 degrees above the circumference of the flange 22. head support stand 2
A rotating arm 24 is provided protruding from the end of the 0. A housing 30 holds the head support 20 on its outer surface, and is composed of an upper housing 31 and a lower housing 32 having approximately semicircular side surfaces. The upper housing 31 has an escape slit 33 so that the driven gear 23 of the head support 20 can rotate, and the slit 3
A tap is formed in the thickness direction of the rear surface 34 formed by 3 so that a pair of screws can be screwed together. The collar portion 22 including the driven gear 23, the head rotation support base having the rotating arm 24, and the upper and lower housings 31 and 32 are made of non-magnetic material such as synthetic resin or zinc alloy and are integrally molded. 40A and 40B are a pair of taps formed on the rear surface 34 of the upper housing 31, and a spring 41,
This is an azimuth adjustment screw that is screwed together via the head support 42, and is configured so that the rotating arm 24 comes into contact with it to regulate the rotational position of the head support base 20. 50 is disposed adjacent to and overlapping the assembly of the head support 20 and the housing 30, and
The drive shaft 5 is a drive means for driving the driven gear 23 of No. 0, and is rotated by a rotation transmission means (not shown).
1, a drive gear 52 which is rotatably supported by the drive shaft 51, and a drive gear 52 which is rotatably supported by the drive shaft 51;
It is composed of a coil spring 53 having one end fixed to the drive shaft 51 and the other end fixed to the drive gear 52, so that the drive gear 52 is rotated via the coil spring 53 as the drive shaft 51 rotates clockwise or counterclockwise. ing.

Note that as a rotation transmission means for rotating the drive shaft 51 of the drive means 50 which is engaged with the driven gear 23 of the head support base 20, for example, a gear may be further provided on the drive shaft 51 on the side facing the drive gear 52, and this gear may be provided with a gear. Various mechanisms and methods can be used, such as a mechanism in which a meshed slider (rack) is slid by a plunger, or a mechanism in which a gear provided on the shaft of a motor drives the gear in rotation.

Next, to explain the rotational operation of the above-mentioned magnetic head device, first, although not shown in the forward state, the drive shaft 51 is rotated in the opposite direction by the forward and reverse selections, as shown in FIG. When the head is rotated by a certain angle in the clockwise direction, the rotational force of the drive shaft 51 is transmitted to the drive gear 52 via the coil spring, and the head is supported by the drive gear 52 rotated in the same direction as the drive shaft 51. The driven gear 23 of the base 20 is rotated counterclockwise, and the magnetic head 10 is energized to rotate by the meshing connection of the driving means, and the head support base 20 is rotated. The arm 24 is brought into contact with the tip of one of the azimuth adjustment screws 40A, and the rotational position of the head support base 20 is regulated, so that the magnetic head is held at the track position with respect to the forward direction. Note that by adjusting the azimuth adjustment screw 40A in this forward state, the azimuth relative to the magnetic tape (not shown) can be easily adjusted by rotationally adjusting the head support base 20 on which the magnetic head 10 is placed.

Next, switching from the forward state to the reverse state is achieved by moving the rotation transmission means in the opposite direction to that in the forward state, so that the engaged driven gear 23 is rotated in the opposite direction to the head support. stand 2
0 rotary arm 24 is the other azimuth adjustment screw 40B.
This is done by touching the tip of the Then, in this reverse state, adjust the azimuth adjustment screw 40.
By adjusting B, the azimuth relative to the magnetic tape (not shown) can be adjusted by rotating the head support base 20 on which the magnetic head 10 is placed.

The magnetic head device constituted by the above-mentioned members includes the lower housing 32 of the housing 30.
is fixed to a head slide plate (not shown), and the driving means 50 and rotation transmission means are respectively fixed to a fixed chassis (not shown) supporting the head slide plate, and the head support base 2 houses the magnetic head 10.
0 is a driven gear 23 meshingly connected to the drive means 50
It is configured to be rotatable about a substantially cylindrical shaft. Therefore, the driving gear 5
It is necessary to ensure that the length of the magnetic head 2 is sufficiently long so that the magnetic head 10 is always engaged with the drive gear regardless of the front and rear positions of the magnetic head 10. In FIG. 2, dotted lines indicate the magnetic head 10, housing 30, etc. in a state in which the head slide plate is moved forward.

In the above-described embodiment, the housing for holding the head support is used as a pair of upper and lower housings, but it is possible to use a single housing.

As explained above, the present invention provides a drive means having a drive shaft rotatably made to rotate with respect to a drive gear and a coil spring fixed at both ends to the drive gear and the drive shaft. The head support is rotated about the substantially cylindrical shaft by the rotation of the driven gear which is meshed with the rotation, and the rotational position of the rotary arm of the head support is regulated by the housing. With this structure, a single coil spring is used as a torque mechanism in the driving means, so when switching the magnetic head, the head support base housing the magnetic head can be attached in one direction with an extremely simple structure. The position can be regulated while increasing the force, and the azimuth regulation position can be stably maintained even when the azimuth is adjusted.

[Brief explanation of the drawing]

FIG. 1 shows a conventional magnetic head device in front, top, and side views, FIGS. 2 to 4 show an embodiment of the present invention, and FIGS. 2A to 2C show front, top, and side views, respectively. 3 is a perspective view of the housing and the head support, and FIG. 4 is a sectional view of the drive means. 10... Magnetic head, 20... Head support stand,
23... Driven gear, 24... Rotating arm, 30... Housing, 40A, 40B... Azimuth adjustment screw, 50... Drive means, 51... Drive shaft, 52...
...Drive gear, 53...Coil spring.

Claims (1)

[Claims for Utility Model Registration] A magnetic head and a head housing portion for housing the magnetic head in the axial direction of the center, a driven gear on the outer periphery, and a rotating arm on one end surface. a cylindrical head support base; the head support base is rotatably held on its outer peripheral surface; and each time the head support base rotates approximately 180 degrees, the rotating arm comes into contact with the head support base to prevent rotation of the head support base; a housing in which a means for regulating the position is formed; a drive gear that meshes with the driven gear of the head support; and a drive shaft that pivotally supports the drive gear and is rotatable relative to the drive gear. and a coil spring that is supported on the drive shaft and has both ends fixed to the drive gear and the drive shaft to transmit rotation from the drive shaft to the drive gear. A magnetic head device for a tape recorder.