JPS639860Y2 - - 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 these 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 FIG. 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, and the adjustment screws 7a, 7b are fixed to
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 and 3 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 both ends. A gear 23 is formed, and a rotating arm 24 is provided protruding from the end thereof. Further, at the end of the cylindrical head support 20, a locking part 25 is formed in the circumferential direction as a protrusion extending approximately 180 degrees, and both ends of the locking part 25 are attached to the end of the head support 20. A slanted portion 25A is formed in this direction. Reference numeral 30 denotes a housing that holds the head support 20 on its outer surface, and includes an upper housing 31 having a substantially semicircular side surface and a lower housing 3.
It is composed of 2. The upper housing 31 has an escape slit 33 so that the driven gear 23 of the head support 20 can rotate, and a pair of screws are screwed into the rear surface 34 formed by the slit 33 in the thickness direction. A tap is formed. and a collar portion 22 including a driven gear 23;
The head rotating support base having the rotating arm 24 and the upper and lower housings 31, 32 are made of a non-magnetic material such as synthetic resin or zinc alloy and are integrally molded. Azimuth adjustment screws 40A and 40B are screwed into a pair of taps formed on the rear surface 34 of the upper housing 31 via springs 41 and 42, and when the rotary arm 24 comes into contact with the screws, the head support 20 rotates. Configured to regulate location.
Reference numeral 50 denotes a regulating means that includes a leaf spring 51 and a regulating pin 52 attached to the tip of the leaf spring 51, and is attached to the rear surface 34 of the upper housing 31 with a screw or the like.
The regulating pin 52 energized by the head support base 20 is configured to engage with the locking portion 25 including the inclined portion 25A of the head support base 20. Reference numeral 60 denotes a driving means for driving the driven gear 23 of the head support base 20, which includes a rack 61 having a linear gear (rack gear), and a sliding plate 63 that supports the rack 61 via a leaf spring 62 and slides on it. It is configured. Sliding plate 63
A shallow groove 63A with a large curvature is formed in the groove 63A, and a groove 61A is also formed in the rack 61. A leaf spring 62 is interposed in both the grooves 63A and 61A, so that the sliding force of the sliding plate 63 is easily reduced. 61, and the rack 61 is always biased toward the driven gear 23 of the head support 20. Although not shown, the sliding plate 63 is connected to sliding means such as a plunger.

Next, to explain the rotational operation of the magnetic head device described above, first, in the forward state, although not shown, the sliding plate 63 of the driving means 60 is moved by the sliding means which moves in both directions depending on the selection of forward and reverse. As the sliding plate 63 moves, the plate spring 62 moves the rack 61 in the same direction, and as shown in FIG. is rotationally energized, whereby the regulating pin 52 of the regulating means 50 interposed between the housing 31 and the head support base 20 is rotated.
is rotated while being engaged with a locking portion 25 formed on the head support base 20, and the rotary arm 24 of the head support base 20 is brought into contact with the tip of one of the azimuth adjustment screws 40A, and the head support base 20 The rotational position of the magnetic head is regulated, and the magnetic head is held at the track position with respect to the forward direction. At this point, the rotating arm 24 of the rotated head support stand 20 comes into contact with the azimuth adjustment screw 40A provided on the housing 30, and the rotation position of the head support stand 20 is regulated. It is locked by the inclined part 25A of the locking part 25 formed on the support base 20. Then, by adjusting the azimuth adjustment screw 40A in this forward state, the head support base 20 on which the magnetic head 10 is placed and energized by the coil spring 65 can be rotated and adjusted to easily adjust the azimuth relative to the magnetic tape (not shown). It can be adjusted to

Here, the regulating means 50 includes a regulating pin 52 which is biased by a leaf spring 51 in the locking portion 25 of the head support base 20.
are engaged and pressed together in the thrust direction of the head support base 20, so that the housing 30 and the head support base 2
0, and also has the function of preventing the head support base 20 from coming off from the housing 30.

Further, as the sliding plate 63 moves, the driving means 60 moves the rack 61 in the same direction, causing the driven gear 24 to rotate until the rotating arm 24 of the head support base 20 is regulated. The overstroke is absorbed by the elasticity of the plate spring 62, or the plate spring 62 is inserted into the groove 6 of the sliding plate 63.
3A and stops on the sliding plate 63 while applying stronger elastic force to the rack 61. Therefore, since the elastic force of the leaf spring 62 always biases the rotary arm 24 of the head support base 20 against the azimuth adjustment screw 40A, the rotational arm 24 of the head support base 20 is constantly biased against the slight change in the amount of movement of the holder 63 when switching in the forward direction. Azimuth adjustment can be performed reliably. The same holds true for switching in the reverse direction, which will be described later, in which case the plate spring 62 always biases the azimuth adjustment screw 40B.

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 drive means 60 is fixed to a fixed chassis (not shown) that supports the head slide plate.
The driven gear 23 is configured to be rotatable about a substantially cylindrical shaft by a driven gear 23 meshingly connected to the driven gear 23.

In addition, when the housing 30 holding the head support stand 20 and the sliding plate 63 of the driving means 60 for rotating the head support stand 20 are respectively fixed to the head slide plate and the fixed chassis as described above, the head slide plate The width of the rack 61 that meshes with the driven gear 23 must be greater than the width that the gear 23 moves. Also, the housing 30 and the drive means 60
In addition to the above-mentioned embodiments, the mounting and fixing location may include a head slide plate, a fixed chassis, etc., but any member may be used depending on the drive system.

Next, when switching from the forward state to the reverse state, the sliding means (not shown) moves in the opposite direction to the forward state, so that the driven gear 23 meshingly connected to the driving means 60 moves in the opposite direction. This is done by bringing the rotary arm 24 of the head support base 20, which is rotationally energized, into contact with the tip of the other azimuth adjustment screw 40B. By adjusting the azimuth adjustment screw 40B in this reverse state, the head support base 20 on which the magnetic head 10 is housed can be rotated to adjust the azimuth relative to the magnetic tape (not shown).

In the above-mentioned embodiment, the regulating means is energized in the thrust direction of the head support in relation to the locking portion 25 formed on the head support, but in addition to this, it is surrounded by, for example, a housing. By forming a locking portion on the circumferential surface of the head support, it is possible to bias the head support in the radial direction. Furthermore, although the regulating means mainly consisting of regulating pins and leaf springs has been described as a single member, a plurality of regulating means may be arranged at regular intervals relative to the locking portion formed on the head support base. A plurality of locking portions may be formed on the outer periphery of the head support base, and a single or a plurality of restricting means may be disposed on the locking portions.
Furthermore, although the locking portion provided on the head support base that engages with and locks the regulating means has been described as a protrusion-like member, it may also be a groove-like member that also functions as a guide.

Furthermore, although the housing for holding the head support is used as a pair of upper and lower housings, it is possible to use a single housing. In other words, in this case, it is necessary to divide the head support into a plurality of parts so that they can be assembled later, such as by dividing one of the flanges formed at both ends of the head support and assembling them. be.

As explained above, the present invention comprises: a head support base that accommodates a magnetic head in the axial direction of a substantially cylindrical shape and is formed with a driven gear and a rotary arm; a housing that holds the head support base; drive means having a drive gear meshingly connected to the driven gear of the head support and driven by a sliding plate, the drive means configured such that the drive gear is energized in the direction of the driven gear of the head support. A spring is disposed between the sliding plate and the drive gear, and rotates the head support base around a substantially cylindrical shaft, and as the rotating arm rotates, the rotational position is regulated by the housing. With this structure, when changing the position of the magnetic head, the head support base that compactly houses the magnetic head can be positioned and locked with an extremely simple configuration, and even when the azimuth is adjusted. The azimuth regulation position can be stably maintained.

[Brief explanation of the drawing]

FIG. 1 shows a front, top, and side view of a conventional magnetic head device, FIGS. 2 and 3 show an embodiment of the present invention, and FIGS. 2a to 2c are front, top, and side views, respectively. , FIG. 3 is a perspective view of the head support. 10... Magnetic head, 20... Head support stand,
23... Driven gear, 24... Rotating arm, 25... Locking portion, 50... Regulating means, 30... Housing,
60...Driving means.

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 rack that meshes with the driven gear of the head support; a sliding plate that supports and slides the rack; and a direction of the driven gear of the head support. A magnetic head device for a tape recorder, comprising: a driving means having an elastic means disposed between the rack and the sliding plate so that the rack is energized.