JPH0612643A - Magnetic recording/reproducing device having rotary drum device and rotary drum - Google Patents

Abstract

PURPOSE:To make a contact between a head and a tape sure by setting a distance between a point where a magnetic head is abutted on a magnetic tape and a point on the rotary drum where the base part of a piezoelectric element larger than the radius of the rotary drum. CONSTITUTION:A piezoelectric element 103 is fixed on a rotary drum 101 fixed on a central shaft 102 by a press plate 104 and a magnetic head 106 is fixed on the tip of this element 103. When a voltage is impressed to the piezoelectric element 103, the element 103 is bent in upward and downward directions with the press plate as a fulcrum and thus, the magnetic head 106 is moved up and down. The displacement amount of the piezoelectric element 103 is proprotional to an impressed volatage and as this amount increases, a linearlity is worsened aganist the impressed voltage, a distance L between a point where the magnetic head 106 touches the magnetic tape and a point on the rotary drum 101 fixed with the base part of the piezoelectric element 103 is set larger than the radius of the rotary drum 101 and thus, this linearlity is improved and the contact condition between the head 106 and the tape is made better.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary drum device provided with a mechanism for driving a magnetic head by using a piezoelectric element, and recording and reproduction by a magnetic head on the rotary drum by a helical scanning loading system. The present invention relates to a magnetic recording / reproducing device of a form.

[0002]

2. Description of the Related Art Conventionally, a rotating portion of a rotary drum device (VTR or the like) equipped with a magnetic head driving mechanism using a piezoelectric element is constructed as shown in FIG.

In FIG. 5, reference numeral 114 denotes a rotary drum, 1
Reference numeral 15 is a rotatable central shaft to which the upper rotating drum 114 is fixed.

Reference numeral 116 is a piezoelectric element mounted on the rotating drum 114, and includes a mechanism (not shown) to which a voltage is applied from the outside.

Reference numeral 117 is a magnetic head fixed to the piezoelectric element, and 118 is a pressing plate for fixing the piezoelectric element 116 to the rotary drum 114 with screws 119.

In such a structure, the piezoelectric element 116
When a voltage is externally applied to the magnetic head 117, the magnetic head 117 moves up and down around the pressing plate 118. By this,
The magnetic head 117 is located at a desired position in the vertical direction.

In a magnetic recording / reproducing apparatus of the type in which recording / reproduction is performed in a form in which a magnetic tape is wound obliquely around a rotating drum, a plurality of magnetic tapes are generally kept in a cassette opening when a tape cassette is loaded. The post is used to pull the tape from the cassette and wind it on the rotating drum at a predetermined angle. In particular, in the case of the M loading method, a tape path that is substantially symmetrical about the rotating drum is formed. For example, immediately before the upstream side and downstream side of the drum inclined to the left when viewed from the cassette side. The tilting post located immediately after is designed to keep the tape tilt parallel to the chassis. Therefore, at the time of loading, the tape is pulled out from the opening of the cassette through the inclined posts and the vertical posts before and after the rotary drum on both the inlet side and the outlet side of the rotary drum, and the tape is obliquely wound around the rotary drum.

[0008]

However, in the above-mentioned conventional example shown in FIG. 5, the angle of contact with the tape changes greatly depending on the position where the magnetic head moves upward or downward (that is, the state of head touch). However, there was a drawback that it had a bad effect such as a decrease in output during playback.

Further, when controlling the vertical position of the magnetic head, linearity with respect to the applied voltage is required. Conventionally, as shown in FIG. 5B, the piezoelectric element 116 is used.
Since the length of L was only shorter than the distance between the rotation center shaft 115 and the tip of the magnetic head 117, there was a drawback that good characteristics could not be expected.

Therefore, in view of the above point, a first object of the present invention is to provide a rotary drum device capable of appropriately controlling the position of the magnetic head.

Further, in such a conventional magnetic recording / reproducing apparatus, since the tape is wound around the inclined rotating drum or the tape is rewound, the tape is twisted between the post and the drum. As a result, the tension in the width direction of the tape becomes uneven, and therefore the tape itself tends to move in the vertical direction. Moreover, since such tape behavior is regulated by the flange portion of the vertical post and loading / unloading is performed, there is a possibility that the tape edge may be damaged if the reel back torque is too high.

Further, since the lower edge of the tape is wound while sliding the lead of the drum during unloading, this also causes damage to the tape. In particular,
In recent years, the thickness of tapes has become thinner, and the problem of tape damage during loading and unloading tends to become more and more ignorable in the future, and active measures have been demanded.

A second object of the present invention is to provide a magnetic recording / reproducing apparatus capable of preventing the tape damage which is likely to occur at the time of loading / unloading in view of the problems of the prior art.

[0014]

In order to achieve the first object of the present invention, the present invention provides a rotary drum device equipped with a magnetic head having a driving mechanism by a piezoelectric element, wherein the magnetic head comes into contact with a magnetic tape. The distance between the piezoelectric element and the point on the rotary drum to which the base of the piezoelectric element is fixed is set larger than the radius of the rotary drum.

In order to achieve the second object, the tape drawn out from the tape cassette is held in a state of being obliquely wound on a rotating drum having a rotary shaft having a predetermined inclination with respect to a reference plane, and recording / recording is performed. In a magnetic recording / reproducing apparatus for reproduction, tilting means for tilting the rotary drum from a state perpendicular to the reference plane to the predetermined tilt, and the rotary drum when the tape is wound and pulled back to the tape cassette. In the vertical state, and means for driving and controlling the tilting means so as to keep the rotary drum in the predetermined tilted state from immediately after the tape is wound to immediately before being pulled back to the tape cassette. is there.

[0016]

According to the present invention, since the length of the movable portion of the piezoelectric element on which the magnetic head is mounted can be made significantly longer than in the conventional case, even when the magnetic head is moved up and down, It is possible to make the posture of the head chip with respect to the magnetic tape more ideal (that is, the angle between the magnetic tape and the head chip is 90 °).

Moreover, since the movable portion of the piezoelectric element becomes long, the angle formed by the head chip and the base portion of the piezoelectric element becomes small, and the linearity of the amount of bending of the piezoelectric element with respect to the applied voltage (that is, the amount of movement of the head chip). Will be good.

Further, according to the present invention, when the tape during loading is wound and when the unloading tape is pulled back to the tape cassette, the winding and pulling back of the tape are performed with the rotating drum kept vertical. After winding the tape, the tilting means tilts the rotary drum to a predetermined tilt to form a tape path, and at the time of unloading, the rotary drum is first returned to the vertical state through the tilting means, and then the tape is pulled back. This is done so that it is possible to prevent damage to the lower edge portion of the tape caused by an unreasonable displacement of the tape when the tape is held obliquely while the rotary drum is tilted as in the conventional case.

[0019]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention. Here, 101 is a rotary drum, and 102 is a central axis fixed to the rotary drum.

Reference numeral 103 is a piezoelectric element, and 104 is a pressing plate for fixing the base portion of the piezoelectric element 103 to the rotating upper drum 101. 105 is a fixing screw. 10
Reference numeral 6 is a magnetic head fixed to the tip of the piezoelectric element 103.

When a voltage is externally applied to the piezoelectric element 103, the piezoelectric element 103 bends in the vertical direction with the pressing plate 104 as a fulcrum, which causes the magnetic head 106 to move up and down. FIG. 1B shows this state.

Now, as shown in FIG. 1B, the bending angle of the piezoelectric element 103 is θ, and the vertical movement amount of the magnetic head 106 is T. This state is changed to the conventional technique ((B) of FIG. 5).
(See), θ <θ '. Generally, the displacement amount (bending amount) of the piezoelectric element 3 is proportional to the applied voltage, but as the displacement amount increases, the linearity with respect to the applied voltage deteriorates.
Therefore, the present embodiment shown in FIG. 1 has much better linearity characteristics than the conventional example shown in FIG.

FIG. 2 shows the contact state between the magnetic head and the tape due to the difference in the fulcrum position. In the figure, 108 is a head supporting surface, 109 is a magnetic head, and 11
Reference numeral 0 is a magnetic tape, and 111 is a head gap position.

In FIG. 2A, since the head supporting surface 108 and the head 109a are parallel to each other, the contact state between the head and the tape is an ideal state. That is, the gap position 111a and the bending apex of the magnetic tape coincide with each other.

FIG. 2B shows the contact state in the present embodiment shown in FIG. 1 at the gap position 111b.
Is slightly deviated from the center point of bending of the magnetic tape.

FIG. 2C shows a contact state of the conventional piezoelectric element head shown in FIG. 5, and a portion between the center position of the head gap and the center of bending of the magnetic tape is shown in FIG. 2B. It is larger than the state.

From the above, the contact state between the magnetic head and the magnetic tape in one embodiment of the present invention is much closer to the ideal state (the same as the normal reproduction) as compared with the conventional state.

FIG. 3 shows a second embodiment of the present invention. In this embodiment, the piezoelectric element 112 has a U-shape (see FIG. 1).
The piezoelectric element has a ring shape).

As a result, the magnetic heads 113a, 11a
3b can move separately. Also,
Also in the case of this embodiment, since the length from the magnetic head to the fulcrum (the base portion of the piezoelectric element) is sufficiently long, the same effect as that of the first embodiment shown in FIG. 1 can be obtained.

FIG. 4 shows a third embodiment of the present invention. The present embodiment is a type in which the magnetic heads are provided at 180-degree opposite positions, but the same effects as those of the above two embodiments can be obtained.

6 to 9 are views for explaining a support mechanism capable of changing the tilt angle of the rotary drum. Of these, FIGS. 6 and 7 show the support mechanism during loading and unloading, and the rotary drum in this embodiment. FIGS. 8 and 9 are views showing a state where the chassis is kept perpendicular to the reference plane of the chassis, and FIGS. 8 and 9 are views showing a state where the rotary drum is inclined by a predetermined angle. Furthermore, FIGS. 10 to 12 show the positions of the respective guide posts when unloading, when loading is completed, and when tape path formation is completed.

In FIG. 6, reference numeral 1 is a rotary drum on which a magnetic head 2 is mounted and is fixed to a drum base 3. The drum base 3 is rotatably supported by a shaft 4 and is biased in a clockwise direction in FIG. 6 by a spring 5. One end of the drum base 3 is in contact with a cam member 6A of a cam gear 6, and Movement is regulated. The cam gear 6 is composed of a cam member 6A, a worm wheel 6B, and a shaft 7 that rotatably supports the cam member 6A and the worm wheel 6B. The worm wheel 6B meshes with a worm 9 driven by a motor 8. On the other hand, the cam member 6A, as shown in FIG. 7, has an arcuate cam surface 6C having an approximately four-quarter circumference and a flat cam surface 6D formed so as to be smoothly continuous with the cam surface 6C. 6, in the state shown in FIG. 7, one end 3A of the drum base 3 is supported by the flat cam surface 6D of the cam member 6A.

Therefore, in the rotating drum support mechanism having the above-described structure, the rotating drum 1 is loaded at the timings described below during the loading and unloading processes.
Is tilted by a predetermined angle, and FIGS. 8 and 9 show a state in which the rotary drum is tilted by a predetermined angle with respect to the reference plane of the chassis in this manner.

Next, the cassette tape loading mechanism according to the present invention will be described with reference to FIG.

Here, 10 is a tape cassette that has a supply reel 11 and a take-up reel 12, and holds a magnetic tape 13 between which the magnetic tape 13 can be drawn out and taken up. Also, 1
Reference numeral 0A denotes an opening of the tape cassette 10, and a loading mechanism for moving the tape 13 to the loading position is arranged at a position corresponding to the tape cassette opening 10A on the apparatus main body side, as shown in this figure. That is, 14 and 15 are tilted posts and vertical posts which are erected on the same base (not shown) and are moved in the direction of arrow L1, and 16 and 17 are the same names and tilted posts and vertical posts which are moved in the direction of arrow L2. Post, 18 is arrow L3
The tension posts 19 and 20 which are moved in the direction are pinch rollers and vertical posts which are moved in the direction of the arrow L4.

On the surface of the chassis parallel to the plane of the drawing, the vertical post 21, the impedance roller 22, the front width erasing head 23, the control and voice erasing head 24, the control and voice recording and reproducing head 25, the capstan 26, A vertical post 27 on the winding side is provided.

Next, the displacement operation of the post and drum during loading will be described below.

The following series of operations is performed by a control means (not shown) of the apparatus.

When it is detected by a sensor (not shown) that the cassette 10 is loaded in the position shown in FIG. 10, a loading motor (not shown) is rotated and the cassette opening 10 is opened.
The posts located in A are indicated by arrows L1 to L4, respectively.
Move in the direction. At this time, the shaft of the rotary drum 1 is kept perpendicular to the reference plane as shown in FIG. 6, and in this state, the tape 13 is wound around the half circumference of the drum 1 as shown in FIG. . In this case, the lead portion 1A (see FIG. 6) of the rotary drum 1 is located lower than the lower edge of the tape 13.

Vertical posts 15 and 17 are shown in FIG.
1 reaches a predetermined position, the motor 8 (see FIG. 6) is urged, and the rotation of the worm 9 causes the cam gear 6 to move to the position shown in FIG.
To rotate in the clockwise direction. Thus, by this rotation, the drum base 3 which is in contact with the cam surface 6D at the end portion 3A is lifted up along the cam surface 6D, and tilts around the shaft 4 as shown in FIG. Thus, when the cam gear 6 rotates about a quarter turn, the drum base end portion 3A is guided to the arcuate cam surface 6C of the cam portion 6A, whereby the drum 1 becomes a predetermined inclination and the motor 8 is stopped. In this case, the inclined posts 14 and 16 move in the direction of the arrow as shown in FIG. 11 together with the above-described inclination of the drum 1, thus forming the regular tape path as shown in FIG.

When unloading, the operation is completely opposite to that at the time of loading. First, the inclined posts 14 and 16 move to the position shown in FIG. After being vertical, the vertical posts 15 and 17, the inclined posts 14 and 16, the tension posts 18, the pinch rollers 19, and the vertical posts 2
0 moves in the direction of the opening 10A of the cassette, and the tape 13 is wound on the reel 12 at the same time.

[0043]

As described above, according to the present invention, the length of the movable portion of the piezoelectric element on which the magnetic head is mounted is
Since it is set longer than the distance from the tip of the head chip to the center of the rotary drum, the effects listed below can be obtained.

(1) The posture of the head chip with respect to the tape is improved, and a change in head touch (a change in reproduction output in the case of a reproducing head) caused by moving the head up and down can be reduced.

(2) Since the angle formed by the tip of the head chip and the fulcrum of the movable part can be made smaller, the moving characteristic (linearity) of the head with respect to the input voltage is improved, and the control of the head drive becomes easier.

(3) Since the voltage applied to the piezoelectric element can be suppressed low, the life is extended.

According to the invention, the tilting means for tilting the rotary drum from the state perpendicular to the reference plane to the predetermined tilt, and the rotary drum when the tape is wound and pulled back to the tape cassette. And a means for driving and controlling the tilting means so as to keep the rotary drum in the predetermined tilted state from immediately after the tape is wound to immediately before being pulled back to the tape cassette. And during the process of unloading, by winding and pulling back the tape while keeping the rotating drum vertical, the force of vertical movement does not act on the tape,
Tape damage due to the post flange can be prevented. In particular, during unloading, the inclination of the drum first changes vertically, and then the lead of the drum separates from the lower edge of the tape, so that there is no rubbing between the lower edge and the lead. Further, since the tape is not subjected to excessive force, it is possible to increase the moving speed of the guide post during loading and unloading, and the loading and unloading times can be shortened and improved operability can be expected.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram for explaining the effect of the present embodiment.

FIG. 3 is a diagram showing a second embodiment of the present invention.

FIG. 4 is a diagram showing a third embodiment of the present invention.

FIG. 5 is an explanatory diagram of a conventional technique.

FIG. 6 is a front view showing the configuration of a rotating drum tilting means.

FIG. 7 is a side view of FIG.

8 is an explanatory view of a tilting operation of the rotary drum by the tilting means shown in FIG.

FIG. 9 is a partial side view of FIG.

FIG. 10 is a block diagram of a main part of a VTR according to the present invention.

11 is an explanatory diagram showing a state during loading of the VTR shown in FIG.

12 is an explanatory diagram showing a loading completed state of the VTR shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 rotary drum 2 magnetic head 3 drum base 3A end part 4 axis 6 cam gear 6A cam member 6C, 6D cam surface 8 motor 10 tape cassette 11,12 reel 13 tape L1-L4 direction 14,16 tilt post 15,17 vertical post 101 , 114 rotating upper drum 102, 107, 115 central axis 103, 112, 116 piezoelectric element 104, 118 pressing plate 106, 113, 117 magnetic head

Claims (2)

[Claims] 1. A rotary drum device equipped with a magnetic head having a driving mechanism using a piezoelectric element, wherein the magnetic head contacts the magnetic tape, and the point on the rotary drum to which the base of the piezoelectric element is fixed. The rotary drum device is characterized in that the distance between them is set larger than the radius of the rotary drum. 2. A magnetic recording / reproducing apparatus for recording / reproducing by holding a tape drawn from a tape cassette in an obliquely wound state on a rotary drum having a rotary shaft having a predetermined inclination with respect to a reference plane. In the tilting means for inclining the rotating drum from the state perpendicular to the reference plane to the predetermined inclination, when the tape is wound and pulled back to the tape cassette, the rotating drum is kept in the vertical state, A magnetic recording / reproducing apparatus comprising: means for driving and controlling the tilting means so as to keep the rotary drum in the predetermined tilted state from immediately after the tape is wound to immediately before being pulled back to the tape cassette.