JPH0422286B2 - - Google Patents

Description

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

Conventional Structure 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, and FIG. 1A is a top view, FIG. 1B is a front view, and FIG. 1C 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 by a head rotation shaft 18, and a driven gear 19 for rotating the head is a drive shaft mounted on a motor. Drive means such as teeth (not shown)
The head rotating shaft 18 is meshed and fixed in the center hole of the driven gear 19.

Further, the head mount 12 is integrally provided with a rotating arm 12a, and the rotating arm 12a is configured to be rotatable together with the head rotating shaft 18. By rotating the drive means in conjunction with the track position switching operation, the head rotating shaft 18 rotates and the magnetic head 11 rotates 180 degrees.

The head rotation shaft support 13 that supports the head rotation shaft 18 is fixed to a head slide plate (not shown), and azimuth adjustment screws 14 and 15 are provided at both ends via springs 16 and 17. The position of the rotary arm 12a is regulated by 14 and 15 to enable azimuth adjustment in the forward and reverse directions, respectively. In the above example, by rotating the azimuth adjustment screws 14 and 15, an attempt is made to obtain the best contact angle between the tape and the magnetic head, the so-called azimuth angle.
By rotating the tape cassette twice, it is possible to perform reciprocal recording and playback, and the tape cassette has the advantage of omitting the operation of reversing it.

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 to rotate the magnetic head. As shown in FIG. 1c, the depth dimension L is inevitably large, and this method is unsuitable for recent small cassette decks and thin cassette decks.

On the other hand, in order to overcome this drawback, a tape recorder having a magnetic head device as shown in FIG. 2 is known. 21 is a magnetic head for recording and reproducing, and 22 is a head mount that houses the magnetic head 21 approximately in the center. This head mount 22 has a flange 22.
The head base 23 functions as a bearing and rotatably holds the outer periphery of the head mount 22. A driven gear 29 is integrally fixed to the other end of the head mount 22, and rotates clockwise or counterclockwise in accordance with the rotation of a drive gear (not shown) to switch the magnetic head between forward and reverse rotation. It's getting old. Numerals 24 and 25 are a pair of azimuth adjustment screws that are screwed into the head mount 22 via springs 26 and 27, as in the conventional example shown in FIG. The rotational position of the mount 22 is regulated. 28 determines the relative position of the rotation center of the head mount 22 and the magnetic head 21, and attaches the magnetic head 2 to the head mount 22.
This is a spacer for adjustment when fixing 1 with adhesive.

The second conventional example configured as described above is
As shown in Figure c, since the head base 23 is also used as a bearing for the head mount 22, the distance L from the front surface of the magnetic head to the magnetic head rotation mechanism is
It has the advantage of being small. 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.

Furthermore, in the first conventional example and the second conventional example, if there is even a slight clearance in the bearing part, the head mount will tilt, causing the magnetic head to rise, which will adversely affect tape running, and furthermore, the magnetic head will tilt. There were drawbacks such as track deviation occurring at the front of the head.

Purpose of the invention The present invention solves the above-mentioned conventional problems.
A tape recorder which realizes a compact and thin tape recorder by reducing the required distance L from the front surface of the magnetic head to the rear end, and also makes it possible to prevent the tape and the front surface of the magnetic head from lifting up and causing no track deviation. It provides:

Structure of the Invention The present invention provides a cylindrical head mount that houses a magnetic head, a head rotation shaft provided at the rotation center of the head mount, a head reversal switching gear that rotates coaxially with the head rotation shaft, and a head rotation switching gear that rotates coaxially with the head rotation shaft. A head rotation support bearing member that pivotally supports a rotating shaft, a head base provided with a V-shaped slope that comes into contact with the outer periphery of the head mount when the tape is running, and a click spring that biases the head mount against the V-shaped slope of the head base. The head rotation shaft is rotated with its center of rotation being regulated by the head rotation support bearing member by a driving means meshingly connected to the head reversal switching gear, and the outer periphery of the head mount is fixed to the head base by a click spring. By being biased by the slope of the mold and regulated in position, the cylindrical part of the head mount is rotated while keeping it parallel to the tape, which prevents tilting and track misalignment and makes it possible to realize a compact and thin tape recorder. be.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below based on the drawings.

Figures 3a, b, c, and d are a front view, a top view, a bottom view, and a left side view, respectively, showing an embodiment of the present invention.
(However, FIG. 3d also includes a side view of the erase head controller). Figures 4a and 4b are top views of the head rotated 90 degrees in one embodiment of the present invention;
The left side view and FIG. 5 are exploded perspective views. Also the 6th
Figures a, b, and c are front views showing the overall configuration of the present invention including the erase head control device, and are respectively in a stopped state and
This indicates the playback status and recording status.

31 is a magnetic head for recording and reproducing, and 32 is a head mount in which the magnetic head 31 is housed approximately in the center, and a head rotation support shaft 32a is integrally formed at the other end at the center of rotation. 33 is a head rotation table fixed to the head mount with mounting screws 36 and 37; 34 is the head rotation support shaft 3;
This is a head reversal switching gear press-fitted into the head 2a, and is adapted to rotate clockwise or counterclockwise by the rotation transmission of the drive gear 35.

38 is a head rotation support bearing plate, which has a bearing portion 38a that pivotally supports the head rotation support shaft 32a;
It is fixed to a head base 50, which will be described later, with mounting screws 39a, b, c, and d. 40 is a cap that prevents the head mount 32 from coming off in the direction of arrow A, and is press-fitted onto the head rotation support shaft 32a.

Reference numerals 41 and 42 designate azimuth adjustment screws that are adjustable via azimuth adjustment springs 43 and 44 on the azimuth adjustment surface 38b bent at right angles of the head rotation support bearing plate 38, and are used to adjust the rotation stopper of the head rotation table 33. The portions 33a and 33b abut against this to determine the azimuth.

45 is a magnetic erasing head; 46 is an erasing head case that houses the magnetic erasing head 45 and is rotatably attached to the head mount side surface 32b with a pin 47 with a gap in the axial direction; and a positioning V-shaped groove 46a. have. Reference numeral 48 denotes a coil spring which is latched at one end to the erasing head case and at the other end to the head mount, and urges the erasing head case in the direction of arrow A.

50 is a head base, which is attached to the head board. The head base 50 has an upper bearing portion 5.
0a is configured to avoid the rotation locus of the magnetic erase head 45 and erase head case 46, and FIGS. 7a, b, and c are the upper bearing portion 50.
They are a BB sectional view, a CC sectional view, and a bottom view of a. The upper bearing part 50a has an opening 50b so that the head mount 32 is exposed on the tape surface side.
is provided. V-shaped slopes 50c and 50d are formed in the opening 50b, and when the outer peripheral surface 32c of the head mount comes into contact with the V-shaped slopes 50c and 50d, the position of the head mount is regulated, and the head mount top surface 32d is It is designed to be held parallel to the tape surface. Further, 50f and 50g are openings 50 on the lower surface 50e of the upper bearing portion 50a.
50h is a V-shaped protrusion provided on the center line C-C on both left and right sides of b, and 50h is the lower surface 50e of the upper bearing part 50a.
This is an erase head shift cam provided on the rotation locus side of the magnetic erase head 45.

52 connects one end 52a to the head reversal switching gear 3.
4, and the other end 52b is connected to the hole 3 on the head rotation support plate 38.
This is a click spring inserted and locked in 8c.

Reference numerals 53 and 54 indicate tape guides provided at both ends of the head base 50.

Next, the overall configuration including the erase head control device of the present invention will be explained with reference to FIG.

Reference numeral 60 indicates a head base plate to which the head base is fixed with mounting screws 61 and 62 and is slidably mounted on a mechanical chassis 63. Reference numeral 64 indicates a long hole 64b so as to be guided by guide pins 65 and 66 implanted on the head base plate. , 64c are provided, and a recording/reproducing control rod 64 is slidably mounted on the head board, and 67 has one end attached to the guide pin 65 and the other end attached to a spring hook 68 implanted on the upper recording/reproducing control rod 64. This is a tension spring that is locked and biases the recording/playback control rod upward.

69 is a plunger fixed to the mechanical chassis 63, and 70 is a shaft 71 installed on the mechanical chassis 63 as a rotation fulcrum, and one end 70a is the plunger 69.
A recording/reproducing lever 73 is rotatably provided at the tip of the recording/reproducing lever 70 with its other end 70b regulated by a stopper 72 planted on the mechanical chassis; This is a tension spring whose end is locked to a spring hook 74 installed on the mechanical chassis 63 and urges the recording/reproducing lever 70 counterclockwise.

The operation of this embodiment configured as above will be described below.

First, to explain the head rotation device, the head reversal switching gear 34 is rotated by the rotation transmission of the drive gear 35, and the head mount 32, which is integrated with the head reversal switching gear, is connected to the bearing part of the head rotation support bearing plate 38. Click spring 5 with 38a as a fulcrum
2, the outer peripheral surface 32c is rotated left and right while being brought into contact with the V-shaped slopes 50c and 50d on the head base. At this time, the erasing head case 46 housing the erasing head 45 attached to the head mount side surface 32b also rotates.

Here, the rotational operation of the erasing head will be explained in detail. V-shaped groove 4 for positioning provided in the erasing head case when normal rotation operation is not performed.
6a are V-shaped protrusions 50f and 50g on the head base
By engaging with the erase head, the position of the erase head, that is, the erase head penetration dimension (vertical position) and the erase head height are determined.

Next, the drive gear 35 drives the head mount 32.
When rotational force is transmitted to the erasing head case 46, the positioning V-shaped groove 46a and the V-shaped protrusion 50f or 50g are disengaged, and the erasing head case 46 shifts downward while rotating. (Position shown by the two-dot chain line in Fig. 3a) After that, while rotating, the engagement between the erasing head case and the V-shaped protrusion is disengaged, and the erasing head shift cam 50h moves the erasing head case downward as shown in Fig. 4b. When the eraser head case is rotated further by 180 degrees, the eraser head case and the eraser head shift cam become disengaged, and the V-shaped protrusion that was engaged with the positioning V-shaped groove of the eraser head case at the start of rotation becomes disengaged. The V-shaped protrusion 50f or 50g on the opposite side engages with the positioning V-shaped groove 40a, and the position of the erasing head is determined again.

Next, the erase head control device section will be explained with reference to FIG. First, from the stopped state in FIG. 6a, the head board is advanced by a stroke _S1 in the direction of arrow D by a head board driving means (not shown) as shown in FIG. 6b, where a regeneration operation is performed. During the first stroke _S2 , the recording/reproducing control rod 64 is operated by a tension spring 67 provided between the head substrate 60 and the recording/reproducing control rod 64.
and move forward in the direction of arrow D. If the head board 60 advances further, the recording/playback control rod 6
4, the stopper part 64a is located at one end 7 of the recording/reproducing lever.
0b and is regulated to the position shown in FIG. 6b, the head board 60 with the head base 50 attached moves forward by a stroke _S1 (against the tension spring 67), and moves forward to the position shown in FIG. 6b.
reach the position.

Further, erasing head locking portions 64d (64e) are provided symmetrically below the recording and reproducing control rod 64.
When the erase head case 46 comes into contact with the erase head 45, the erase head case 46 contacts the erase head 45 when the tape is being played back, that is, when the head board is fully advanced by the stroke _S1 .
is rotated counterclockwise around the pin 47 against the coil spring 48 so as to separate from the aperture window surface 75a of the tape cassette 75, and pushed down, and only the tape 76 and the recording/playback head 31 come into contact with each other, resulting in a playing state. Become.

When the next recording operation is performed, the plunger 69 is first energized to attract the rod 69a as shown in FIG. 6c. So Rod 69
One end 70a of the recording/reproducing lever 70 that is engaged with the stepped part a is also pulled to the right, and the recording/reproducing lever 70 rotates around the support shaft 71 on the mechanical chassis 63 against the tension spring 73 and rotates clockwise. rotate in the direction. In this state, the head board 60 to which the head base 50 is attached is moved forward by a stroke _S1 in the direction of the arrow D as in the case of playback, but this time the recording/playback lever 70 is rotated by the plunger and the recording/playback control rod 64 is moved forward. Since it is in a positional relationship in which it does not come into contact with the stopper portion 64a, the recording/reproducing control rod 64 moves forward by a stroke _S1 in the direction of arrow D integrally with the head board 60 by the tension spring 67. At this time, the opening window 75 of the tape cassette 75
The recording/reproducing head 31 enters through the opening 75c, and the magnetic erasing head 45 comes into contact with the tape 76 to enter the recording state.

Here, we have described the case where the tape 76 is running in the direction of arrow E, but if the tape running direction is reversed, the recording/reproducing head 31 and erasing head 45 will rotate 180 degrees, and the erasing head will be moved by the same operation as above. control.

Further, even if the energization to the plunger 69 is stopped when the stopper portion 64a of the recording/reproducing control rod 64 moves forward by a stroke _S1 along with the head board 60 while avoiding contact with the tip 70b of the recording/reproducing lever 70, Since the recording mode continues, not much current is consumed to energize the plunger.

With the above configuration, for example, the external force shown by the arrows shown in FIG. 3b and d is applied to the magnetic head 31.
Even when the head mount 32 is pressed against the V-shaped slope formed on the head base 50 by the pressing force P of the click spring 52, the head mount 32, that is, the head surface is always kept parallel to the tape surface. It will be. Regarding track deviation on the front surface of the head, even if there is a clearance in the bearing portion, no inclination amount occurs at the front surface of the head, so a track deviation larger than the amount of clearance does not occur.

Effects of the Invention The present invention provides a cylindrical head mount that houses a magnetic head, a head rotation shaft provided at the rotation center of the head mount, a head reversal switching gear that rotates coaxially with the head rotation shaft, and a head rotation switch gear that rotates coaxially with the head rotation shaft. A head rotation support bearing member for pivotally supporting a shaft, a head base provided with a V-shaped slope that contacts the outer peripheral surface of the head mount while the tape is running, and a click spring that biases the head mount against the V-shaped slope of the head base. The head rotating shaft rotates with its center of rotation determined by the bearing part of the head rotation support bearing member, and is rotated by the driving means meshingly connected to the head reversing switching gear, and is rotated by the pressing force of the click spring. Therefore, the outer circumferential surface of the head mount is pressed against the V-shaped slope on the head base, and the head mount is configured to rotate while keeping the facing side of the tape parallel to the tape, so that the magnetic head can be rotated from the front side to the rear end. Therefore, it is possible to provide an excellent tape recorder equipped with a magnetic head device that allows the distance between the tape and the front surface of the magnetic head to be reduced, and also prevents the occurrence of track misalignment between the tape and the front surface of the magnetic head.

[Brief explanation of drawings]

Fig. 1a is a top view showing the main parts of a conventional tape recorder, b is a front view thereof, c is a right side view thereof, Fig. 2a is a top view of another conventional example, b is a front view thereof,
FIG. 3c is a right side view of the tape recorder, FIG. Figure a is a top view of the embodiment shown in Figure 3 when the head section is rotated 90 degrees, b is a left side view, and Figure 5
The figure is an exploded perspective view of this embodiment, and FIG. 6a is a front view of this embodiment including the erase head control device when stopped.
b is the front view during playback, c is the front view during recording, 7th
Figure a is a left sectional view showing the upper bearing portion on the head base, figure b is a front sectional view, figure c is a bottom view, and Figure 8 is a perspective view of the tape cassette. 31...Magnetic head (for recording/playback), 32...Head mount, 33...Head rotating table, 34
... Head reversal switching gear, 35 ... Drive gear, 3
8...Head rotation support plate, 41, 42...Azimuth adjustment screw, 45...Magnetic erasing head, 46...Erasing head case, 50...Head base, 60...Head board, 64...Recording/playback control rod , 69...Plunger, 70...Recording/playback lever.

Claims (1)

[Claims] 1. A cylindrical head mount housing a magnetic head, a head rotation shaft provided at the rotation center of the head mount, a head reversal switching gear that rotates coaxially with the head rotation shaft, and a head rotation switching gear that pivotally supports the head rotation shaft. It is characterized by comprising a head rotation support bearing member, a head base provided with a V-shaped slope that contacts the outer periphery of the head mount while the tape is running, and a click spring that biases the head mount against the V-shaped slope of the head base. tape recorder.