JPH0827919B2 - Rotating head device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary head device used in, for example, a magnetic recording device.

2. Description of the Related Art In recent years, rotary head devices have been used in video tape recorders (VT
R) has been widely used with the development of, various efforts have been made to improve performance.

A conventional rotary head device will be described below with reference to the drawings.

In the conventional rotary head device, as shown in the specific configuration in FIG. 4, the tape is run by a rotary cylinder 2 which oscillates at 1000 rpm to 2000 rpm with respect to the tape 1 and a fixed cylinder 3 which does not oscillate. It is structured to guide you. A lead 4 is provided on the fixed cylinder 3 for the purpose of restricting the position of the magnetic tape 1 during traveling. The rotary head 5 is held by the rotary cylinder 2 so as to protrude from the outer peripheral surface of the rotary cylinder 2 to the outside by approximately several tens of microns. Again 6
Is a magnetic head mounting window.

The operation of the conventional rotary head device configured as described above will be described below.

The fixed cylinder 2 oscillates at 1000 to 2000 rpm, and at the same time, a predetermined tape tension is applied to the magnetic tape 1 so that the rotating cylinder 2 and the fixed cylinder 3 are obliquely wound at a predetermined angle and run. The rotary head 5, which is held by the fixed cylinder 2 so as to project from the outer peripheral surface of the fixed cylinder 2 to the outside by approximately several tens of microns, is rotating while being in contact with the tape 1.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the above-described structure, as shown in FIG. 5, the air film 7, which is a thin layer of air, is formed on the peripheral surface of the rotary cylinder 2 as the rotary cylinder 2 rotates. Or
Since the tape 1 travels along the lead 4, the lead portion 4 is lowered as it travels to the tape splicing inlet (A), the intermediate position (B), and the tape splicing outlet (C). As shown in FIG. 6, a magnetic gap portion of the rotary head 5 and a gap between the rotary head 5 and a normal line m of the surface where the tape 1 and the rotary head 5 contact each other are provided with a gap for generating or picking up a leakage magnetic flux. The line n connecting the center of curvature in the longitudinal direction near the magnetic gap may not match. 6 and 7 show an example of a conventional rotary head device, and FIG. 7 shows a case where the tape has a higher rigidity than FIG. 6, and α is the straight line m and the straight line n shown above. Is the angle formed by.

The larger the angle α, the larger the space loss in the so-called magnetic recording or reproducing process, and the signal recording or reproducing performance deteriorates. However, in the conventional rotary head device, the value of α may be large. Therefore, there is a problem that the recording or reproducing performance of the signal is deteriorated. Moreover, for example, as shown in FIGS. 6 and 7, since the rigidity of the tape changes or the thickness of the tape changes depending on the type of tape, the value of α changes depending on the type of tape. Was there.

In view of the above problems, the present invention reduces the recording or reproducing performance of a signal by improving the contact state between the tape and the rotary head (always keep α at approximately 0 °) according to the change in the type of tape. The present invention provides a rotary head device for prevention.

Means for Solving the Problems In order to solve the above problems, the rotary head device of the present invention is a fixed cylinder for winding and guiding a tape obliquely at a predetermined angle, and rotating at a predetermined rotation speed. And a rotary head having a magnetic gap portion for recording or reproducing a signal on the tape, and a magnetic gap portion of the rotary head and the magnetic gap with respect to a normal line of a surface where the tape and the rotary head contact each other. Of the tape, a rotating means for rotating the rotary head so that a line connecting the centers of curvature in the longitudinal direction of the tape in the vicinity of the portion substantially coincide with each other, a selecting means for selecting the type of the tape, and a selecting means of the selecting means. And a control means for controlling the rotation angle of the rotary head according to the output.

Operation The present invention controls the head with the above-described structure, stabilizes the contact state between the tape and the head, reduces the space loss, and prevents the deterioration of the signal recording or reproducing performance.

Embodiment A rotary head device according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a rotary head device according to an embodiment of the present invention. Reference numeral 11 is a rotary cylinder, 12 is a fixed cylinder, 13 is a tape, 14 is a rotary head, 15 is a head mount made of an insulating material, and 16 and 17 are a pair of parallel arms made of a shape memory alloy. The arms 16 and 17 are supported by the rotating cylinder 11 so as to be parallel to each other. And arm 16
And the arm 17 remember the shape that they are separated from each other in opposite directions. Arms 16 and 17 are supplied with control currents from power sources 18 and 19 (see FIG. 3) and generate heat due to internal resistance.
The arm is designed to be deformed by changing its temperature.
A head mount 15 and a head mount 15 carried by being connected to the tips of these two arms by deformation of 16 and the arm 17.
The rotary head 14 carried on the tip of 15 is configured to rotate. Also, (A) is the tape splicing entrance portion in FIG. 5, and (B) is the intermediate position in FIG.
(C) is the tape splicing outlet in FIG.

FIG. 2 shows a sectional view of the rotary head device in one embodiment of the present invention. The structure is the same as that of FIG. 1, but the type of tape 13 is changed.

FIG. 3 shows an overall view of the same embodiment. Reference numeral 21 denotes a selection button, which is used to select the tape type. Reference numeral 22 denotes a power supply voltage selecting means, which applies a voltage to the power supplies 18 and 19 according to the output of the selection button 21. And power supply 18,
A control current is passed from 19 to the arms 16 and 17 through a slip ring 23, which is a well-known means, and heat is generated by internal resistance to change the temperature to deform the arms 16 and 17, and the deformation causes the rotary head 14 to rotate. Has become.

The operation of the rotary head device configured as described above will be described below with reference to FIGS. 1, 2, and 3.

First, FIG. 1 shows a rotary head device according to an embodiment of the present invention. At the position of the tape splicing inlet (A) (rotation angle θ = 0 °) of FIG. As shown in (A) of the figure, the normal line of the surface where the tape 13 and the rotary head 14 contact each other, the magnetic gap part of the rotary head 14 and the center of the longitudinal curvature near the magnetic gap part of the rotary head 14. Since the angle α formed by the line connecting with and is large, the control current is passed from the power supply 19 (see FIG. 3) to the arm 17 to make the value of α approximately 0 °, and the internal heat generated by the resistance causes the arm to generate heat.
By raising the temperature of 17, the arm 17 undergoes phase transformation and deforms due to superelasticity, and the rotary head 14 and head mount 15
Is rotated as shown in FIG. 1 (A) so that the value of α becomes approximately 0 °. Next, while moving from the position of the tape splicing inlet (A) in FIG. 1 (rotation angle θ = 0 °) to the intermediate position (B) in FIG. 1 (rotation angle θ = 90 °), the angle α is The control current from the power source 19 (see FIG. 3) is set so that it is always approximately 0 °. Therefore, the intermediate position (B) in FIG.
Then, the tip of the rotary head 14 (the magnetic gap portion) comes to the position shown in FIG. Next, while moving from the intermediate position (B) in FIG. 1 (rotation angle θ = 90 °) to the position of the tape splicing outlet (C) in FIG. 1 (rotation angle θ = 180 °), the angle α remains The control current from the power source 19 (see FIG. 3) is set so that it is always approximately 0 °. Therefore the first
At the position of the tape splicing outlet (C) in the figure, the position of the tip (magnetic gap portion) of the rotary head 14 comes to the position as shown in FIG. From the position of the tape splicing outlet (C) in FIG. 1 (rotation angle θ = 180 °) to the position of the tape splicing inlet (A) in FIG. 1 (rotation angle θ = 360 °), the rotary head 14 The tip of the is designed to change continuously and smoothly.

As shown in FIGS. 1A, 1B, and 1C, the rotary head 14 has the simple structure as described above.
By setting the power sources 18 and 19 (see FIG. 3) so that the angle α of is always 0 °, the contact state with the tape 13 near the magnetic gap of the rotary head 14 can be improved. Space loss can be kept to a minimum.

However, when the type of tape changes, as shown in FIGS. 6 and 7, the contact state between the tape and the head also changes. Therefore, a selection means (see FIG. 3) for selecting the type of tape is provided, and the power supply 18, 19 is selected according to the output.
Set.

First, by selecting the type of tape with the selection button 21, the power supply voltage means 22 causes an output corresponding to the type of tape to flow a current through the slip ring 23, which is a well-known means, to the power supplies 18 and 19, and the arm 16 and By adjusting the shape of the arm 17, the locus of rotation of the rotary head 14 is changed according to the type of tape. By using the two arms 16 and 17, the power can be controlled at two locations, the power sources 18 and 19, so that the accuracy is improved and the controllability is improved. FIG. 2 shows the case where the rigidity of the tape is higher than that in FIG.

The operation in FIG. 2 is the same as that in FIG. 1. First, at the position of the tape splicing inlet (A) in FIG. 2 (rotation angle θ = 0 °), the operation shown in FIG. As shown, the normal line of the surface where the tape 13 and the rotary head 14 contact each other and the line connecting the magnetic gap part of the rotary head 14 and the center of the longitudinal curvature near the magnetic gap part of the rotary head 14. Since the value of the angle α formed is large, in order to set the value of α to approximately 0 °, a control current is passed from the power source 19 (see FIG. 3) to the arm 17 and the temperature of the arm 17 is raised by internal heat generation by the resistance. By doing, the arm 17 undergoes phase transformation and deforms due to superelasticity,
The rotary head 14 and the head mounting base 15 are lowered as shown in FIG. 2 (A) so that the value of α becomes approximately 0 °. Next, from the position of the tape splicing inlet (A) in FIG. 2 (rotation angle θ = 0 °) to the intermediate position (B) in FIG. 2 (rotation angle θ =
The control current from the power source 19 (see FIG. 3) is set so that the angle α is always approximately 0 ° while moving to 90 °). Therefore, at the intermediate position (B) in FIG. 2, the position of the tip (magnetic gap portion) of the rotary head 14 comes to the position as shown in FIG. Next, the intermediate position (B) in FIG.
(Rotation angle θ = 90 °) From tape attachment outlet (C) in Fig. 2
The limiting current from the power source 19 (see FIG. 3) is set so that the angle α is always substantially 0 ° even while moving to the position (rotation angle θ = 180 °). Therefore, at the position of the tape splicing outlet (C) in FIG. 1, the position of the tip (magnetic gap portion) of the rotary head 14 comes to the position shown in FIG. 2 (C). From the position of the tape splicing outlet (C) in FIG. 2 (rotation angle θ = 180 °) to the position of the tape splicing inlet (A) in FIG. 2 (rotation angle θ = 360 °), the rotary head 14 The tip of the is designed to change continuously and smoothly.

With the configuration as described above, (A) of FIG.
As shown in (B) and (C), the angle α of the rotary head 14 is
By setting the power supplies 18 and 19 (see FIG. 3) so that is always 0 °, the contact state with the tape 13 in the vicinity of the magnetic gap part of the rotary head 14 can be improved, resulting in space loss. Can be kept to a minimum.

As described above, according to the present embodiment, by improving the contact state between the tape and the rotary head according to the type of the tape with a simple configuration, it is possible to prevent the deterioration of the signal recording or reproducing performance, and further to store the shape memory. By using two alloys,
It is possible to provide a rotary head device having a simple structure and high controllability.

Although the shape memory alloys 16 and 17 are used in FIG. 1, the same effect can be obtained by using the electrostrictive characteristic in which distortion occurs when the voltage of the piezoelectric element is applied.

As described above, according to the present invention, the line connecting the magnetic gap portion of the rotary head and the center of curvature in the tape longitudinal direction in the vicinity of the magnetic gap portion to the normal line of the surface where the tape and the rotary head contact each other. Rotating means for rotating the rotary head so that the two values substantially coincide with each other, and a selecting means for selecting the type of the tape,
By providing a control means for controlling the rotation angle of the rotary head according to the output of the selection means, the contact angle between the head and the tape is made vertical, thereby improving the contact state between the tape and the rotary head. , To prevent deterioration of signal recording or reproducing performance.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of a rotary head device according to an embodiment of the present invention, and FIG. 1 (A) is an enlarged view of the tape splicing entrance portion shown in FIG. 6, FIG. ) Is an enlarged view at an intermediate position shown in FIG. 6, FIG. 1 (C) is an enlarged view of the tape splicing outlet portion shown in FIG. 6, and FIG. 2 is a main part of the rotary head device of the embodiment. It is a cross-sectional view, in which the type of tape is changed. FIG. 2 (A) is an enlarged view of the tape splicing entrance portion shown in FIG. 6, FIG. 2 (B) is an enlarged view of the intermediate position shown in FIG. 6, and FIG. FIG. 3 is an enlarged view of the tape splicing outlet shown in the figure, FIG. 3 is a block diagram of means for selecting the type of tape, FIG. 4 is a front view of a conventional rotary head device, and FIG. 5 is a conventional rotary head device. FIG. 6 is a cross-sectional view of a main part of a conventional rotary head device, and FIG. 6 (A) is an enlarged view of a tape splicing inlet part.
FIG. 6B is an enlarged view at an intermediate position, FIG. 6C is an enlarged view of a tape splicing outlet portion, FIG. 7 is a cross-sectional view of a main part of a conventional rotary head device, and FIG. ) Is an enlarged view of the tape splicing inlet part, FIG. 7 (B) is an enlarged view of the intermediate position, and FIG. 7 (C) is an enlarged view of the tape splicing outlet part. 11 …… Rotary cylinder, 12 …… Fixed cylinder, 14 ……
Rotating head, 15 ... Mounting base, 16 ... Arm, 17 ... Arm, 18 ... Power supply, 19 ... Power supply, 21 ... Selection button, 22
...... Power supply voltage selection means.

Claims (2)

[Claims] 1. A fixed cylinder for winding and guiding a tape obliquely at a predetermined angle, and a magnetic gap portion for rotating at a predetermined number of revolutions and recording or reproducing a signal on the tape. A line connecting the rotary head having the magnetic gap portion of the rotary head and the center of curvature in the longitudinal direction of the tape in the vicinity of the magnetic gap portion to a normal line of a surface where the tape and the rotary head contact each other is substantially Rotating means for rotating the rotary head so that they coincide with each other, selecting means for selecting the type of the tape, and control means for controlling the rotating angle of the rotary head according to the output of the selecting means. A rotary head device provided. 2. The rotating means comprises two arms made of a shape memory alloy which are mounted on a rotating drum and are arranged in parallel to each other on the left and right sides and which are memorized for being deformed in mutually opposite directions. The rotary head device according to claim 1, further comprising: a rotary head connected to and carried by the tips of the two arms.