JPH0442420A - Rotary head cylinder device - Google Patents

Abstract

PURPOSE:To prevent a magnetic head from wearing and to prolong the service life of it by providing a shape varying means that is the part of the outer peripheral cylinder part of a rotary cylinder and which varies at least the shape of the adjacent part of the magnetic head corresponding to the recording/reproducing phase of the magnetic head. CONSTITUTION:The rotary cylinder 40 is formed in the laminate structure of plural cylindrical members 44 and spacers 45, and a shape varying member 43 is formed in ring shape composed of plural piezoelectric ceramic elements, and is mounted on the outer peripheral plane of the spacer 45, however, it is not fixed on the cylindrical member 44. In the shape varying member 43, the radius of the cylindrical plane of the member can be controlled by applying a voltage by using a slip ring, etc., corresponding to the detection result of the recording/reproducing phase by a mode detecting means, and a projecting part 41 larger in a radius direction that the magnetic head 2 is formed in the vicinity of the magnetic head 2 on the outer peripheral cylindrical plane of the rotary cylinder 40 in a fast forward/rewinding mode. Thereby, since no contact between a magnetic tape 4 and the magnetic head 2 occurs in the fast forward/rewinding mode even when the magnetic tape 4 is wound across the rotary cylinder 40, the wear of the magnetic head 2 can be prevented from occurring, which prolongs the service life.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a rotary head cylinder device for magnetic recording and reproduction used in video tape recorders, digital audio recorders, and the like.

Conventional technology In recent years, video tape recorders, digital audio recorders, etc. are required not only to have high image and sound quality, but also to have high functionality, such as fast forwarding and rewinding speeds, and short mode switching times. . Along with this, there is a demand for more advanced basic elemental technology for recording and reproducing magnetic tape using the magnetic head cylinder method.

Among these, when recording/playing is performed immediately after fast forwarding 7 rewinds, in order to shorten the mode switching time, it is possible to run the magnetic tape at crystal speed while loading it to the recording/playback position and perform fast forward 7 rewinds. There is a method to shorten the mode switching time.

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

FIG. 8 is a top view of the rotating head cylinder device and traveling system in the recording/reproducing mode, FIG. 9 is a side sectional view of the rotating head cylinder device, and FIG. 10 is an arrow a in the LL cross section shown in FIG. 9. The perspective view, FIG. 11, is a top view of the rotary head cylinder device and the traveling system in the fast forward 7 rewind mode.

In the figure, the rotating head cylinder device and traveling system are as follows:
An entry post 8, an exit post 9, and a roller post 103 for guiding the magnetic tape 4, and an erasing head 1 for erasing signals recorded on the magnetic tape 4.
02, an audio control head 104 for recording/reading audio signals and control signals for running the magnetic tape 4 at a constant speed, respectively;
an impedance roller 101 which is a rotating member attached to the magnetic tape 4 in order to suppress vibrations of the magnetic tape 4; a tensilon regulator 100 which is a tension detector for controlling the magnetic tape 4 to give a constant tension;
A capstan 105 that drives the magnetic tape 4 by pressing it through a pinch roller 106, and a supply reel 10 and capstan 105 that supply the magnetic tape 4 to the upstream side of the capstan 105 housed in a cassette half 107. and a take-up reel 11 for winding up the magnetic tape 4 on the downstream side.

The magnetic tape 4 is pulled out from the cassette half 107 and wound around the upper cylinder 1 and the fixed cylinder 3. A magnetic head 2 is attached to the lower end surface of the fixed cylinder 1 in the axial direction, which is disposed coaxially and facing the fixed cylinder 3.

Further, a groove portion 6 is provided in the outer circumferential cylindrical portion of the rotary cylinder 1 .

The magnetic tape 4 is guided by an entry post 8 and an exit post 9, and is guided from a scan start phase 16 to a scan end phase 1.
7 is wound around the rotating cylinder 1 and the fixed cylinder 3. The fixed cylinder 3 is provided with a lead 15 which is a stepped portion for guiding the magnetic tape 4. The rotating cylinder 1 and the rotating shaft 19 are integrally fixed by a disk 7. A motor 18 for rotationally driving the rotary cylinder 1 is fixed to the rotary shaft 19 .

Further, in order to electrically connect the magnetic head 2 and a signal processing circuit (not shown), a rotor core 13 fixed to the disk 7 and rotating integrally with the rotating cylinder 1, and a stator core fixed to the fixed cylinder 3 are provided. 14 are arranged facing each other to form a rotary transformer.

A pulse generator 25 that generates a signal according to the rotational phase of the rotary cylinder 1 is provided in the motor 18 .

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

In the recording/playback mode, the magnetic tape 4 is connected to the supply reel 10.
Impedance roller 101° Full erase head 1
02. Roller post 103. Entrance post 8. Fixed cylinder 3. Exit post 9. audio control head 1
04, Tensilon regulator 100
The capstan 1 is held between the capstan 105 and the pinch roller 106 while receiving appropriate tension.
The rotation of 05 causes the take-up reel 1 to travel in the direction of arrow A.
1.

The rotating cylinder 1 rotates in the direction of arrow B while being rotationally controlled based on the signal from the pulse generator 25 with the magnetic tape 4 wound around it.
Since the running speed of the magnetic head 2 is different from that of the magnetic tape 4, the magnetic head 2
Move relative to the top. That is, as the rotary cylinder 1 rotates, it comes into contact with the magnetic tape 4 in the scanning start phase 16 and starts moving on the magnetic tape 4. When the rotating cylinder 1 further rotates by an angle θ, it separates from the magnetic tape 4 at a scanning end phase 17, completing one movement. The magnetic head 2 moves over the magnetic tape 4 one after another while repeating the above operations.

On the other hand, in the fast forward 7 rewind mode, the pinch roller 106
is detached from the capstan 105, and the magnetic tape 4 is wound onto the winding wheel 11, thereby running at a higher speed than during reproduction. Other operations are the same as during playback.

Problems to be Solved by the Invention However, as in the above-mentioned conventional example, the magnetic tape is attached to the magnetic head during the fast forward and seven rewind modes, so when the magnetic tape is wound around the rotating cylinder, the magnetic head is worn out. In order to suppress this wear, the allowable time in the fast forward and seven rewind modes has been restricted.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a rotary head cylinder device in which a magnetic head does not wear out even when a magnetic tape is wound around a rotary cylinder during fast forwarding and rewinding.

Means for Solving the Problems In order to solve the above-mentioned problems, the rotary head cylinder device of the present invention changes the shape of at least the outer cylindrical portion of the rotary cylinder near the magnetic head in accordance with the recording/reproducing phase of the magnetic head. The technical means is to use a shape changing means to change the shape.

Effect: By providing the above-mentioned means, that is, a shape variable means for changing the shape of at least the portion of the outer cylindrical portion of the rotating cylinder near the magnetic head in accordance with the recording/reproducing phase of the magnetic head, the magnetic tape can be transferred to the rotating cylinder. Since the magnetic tape and the magnetic head do not come into contact with each other during fast forwarding and rewinding even if the magnetic tape is wound around the tape, wear of the magnetic head can be prevented and its life can be extended.

EXAMPLE Hereinafter, a first example of the rotary head cylinder device of the present invention will be described with reference to the drawings.

FIG. 1 is a side sectional view of the first embodiment of the rotary head cylinder device of the present invention in the fast forward 7 rewind mode, FIG. 2 is an enlarged view of part 0 in FIG. 1, and FIG. 3 is the rotation of the present invention. A side sectional view of the first embodiment of the head cylinder device in recording/reproducing mode, FIG. 4 is an enlarged view of section D in FIG. 3, and FIG. It is a diagram.

In these figures, the same parts as in the conventional example are given the same reference numerals, and the explanation thereof will be omitted.

In the figure, the rotating cylinder 40 has a laminated structure of a plurality of cylindrical members 44 and spacers 45.

The variable shape member 43 has a ring shape composed of a plurality of arc-shaped piezoelectric ceramic elements, and the spacer 4
5, but is not fixed to the cylindrical member 44. The variable-shape member 43 changes its outer cylindrical surface by applying a voltage using a voltage supply means (not shown) such as a slip ring according to the recording/reproduction phase detection result by a mode detection means (not shown). The polarization orientation is such that the radius of the polarization increases or decreases. As shown in FIGS. 1 and 2, in the fast forward 7 rewind mode, voltage is applied and the magnetic heald 2 on the outer cylindrical surface of the rotating cylinder 40 is
A protrusion 41 that is larger in the radial direction than the magnetic helad 2 is formed near the magnetic head 2 . Further, in the recording/reproducing mode, the groove portion 21 is formed by the cylindrical member 44 and the shape variable member 43. The other configurations are the same as the conventional example.

The operation of the rotary head/linda device configured as described above will be explained below.

As shown in FIG. 5, the magnetic tape 4 is wound around a rotary cylinder 40 and a fixed cylinder 3 by a magnetic tape loading means (not shown), and is running in the direction of arrow A. The rotating cylinder 40 rotates in the direction of arrow B with the magnetic tape 4 wound around it.
Since the peripheral speed of 0 is different from the running speed of the magnetic tape 4, the magnetic head 2 moves relatively over the magnetic tape 4. Here, in the fast forward 7 rewind mode, voltage is applied, so as shown in FIGS. 1 and 2, the variable shape member 4
3 has a large radius and protrudes from the magnetic head 2. Therefore, since the magnetic tape 4 is not attached to the magnetic head 2, the magnetic head 2 does not wear out.

On the other hand, by stopping the application of voltage during recording/reproduction, the variable-shape member 4 as shown in FIGS.
Since the radius of the magnetic tape 3 becomes smaller, the magnetic tape 4 can be attached to the magnetic head 2 and recording/reproduction can be performed.

As described above, by providing the variable shape member that changes the shape of the outer cylindrical portion of the rotary cylinder 40 near the magnetic head 2 in accordance with the recording/reproducing phase of the magnetic head 2, it is possible to record a magnetic tape. Even if the magnetic tape is wound around a rotating cylinder, the magnetic tape and the magnetic head do not come into contact during fast forwarding and rewinding, so it is possible to prevent wear of the magnetic head and extend its life.

Furthermore, as shown in FIGS. 3 to 5 of this embodiment, a groove 21 necessary for recording/reproducing can be formed in the outer cylindrical portion of the rotary cylinder 40. Further, in this embodiment, the variable shape member 43 is formed into a ring shape made up of a plurality of arc-shaped piezoelectric ceramic elements, thereby making it easy to attach the variable shape member 43.

In this embodiment, the variable shape member 43 is made of a piezoelectric ceramic element, but other organic piezoelectric elements may be used as long as the shape of the outer cylindrical portion of the rotary cylinder 40 and the vicinity of the magnetic head 2 is variable and controllable. A material such as a shape memory alloy or the like may be used, and the material and structure are not limited.

For example, the variable shape member 43 may have a shape of the protrusion 41 of V.
You may use a shape memory alloy that changes the shape or arc shape, or by integrally configuring the rotary cylinder 40 including the protrusion 41 with a shape memory alloy, the protrusion 41
It is obvious that the same application can be made even if the shape of is changed.

A second embodiment of the rotary head cylinder device of the present invention will be described below with reference to the drawings.

FIG. 6 is a perspective view of a second embodiment of the rotary head cylinder device of the present invention in recording/reproducing mode, and FIG. 7 is a side sectional view thereof. In these figures, the same parts as in the first embodiment are given the same reference numerals, and the explanation thereof will be omitted.

In the figure, a rotating cylinder 40 is covered with a film 46 made of a flexible material, for example containing carbon fibers.

The variable shape member 47 is formed by separating a plurality of members into spacers 4.
5, but is not fixed to the cylindrical member 44. The film 46 is configured to be deformed by a shape variable member 47. The other configurations are the same as the first embodiment.

The operation of the rotary head cylinder device configured as described above is the same as that in the first embodiment, so a description thereof will be omitted.

As described above, the variable shape member 43 that changes the shape of the outer cylindrical portion of the rotating cylinder 40 near the magnetic head 2 in accordance with the recording/reproducing phase of the magnetic head 2, and the outer cylindrical surface of the rotating cylinder 40 By providing the film 46 made of a flexible material covering the magnetic tape 4, the magnetic tape 4 and the magnetic head 2 do not come into contact with each other during fast forwarding and rewinding even if the magnetic tape 4 is wound around the rotating cylinder 40. Not only is it possible to prevent wear and extend the service life, but the variable shape member 47 can be constructed by separating a plurality of members, which reduces the volume and mass of the variable shape member 47, which reduces costs. It has a great effect on 1lffi.

Effects of the Invention As described above, according to the present invention, a shape changing means is provided for changing the shape of at least the portion of the outer peripheral cylindrical portion of the rotary cylinder near the magnetic head in accordance with the recording/reproducing phase of the magnetic head. Therefore, even if the magnetic tape is wound around a rotating cylinder, the magnetic tape and the magnetic head do not come into contact during fast forwarding and rewinding, so it is possible to prevent magnetic wear and prolong the life of the magnetic tape.

[Brief explanation of the drawing]

FIG. 1 is a side cross-sectional view of a rotary head cylinder device in a fast forward 7 rewind mode in a first embodiment of the present invention, FIG. 2 is an enlarged view of section 6 in FIG. 1, and FIG. 3 is an embodiment of the present invention. FIG. 4 is an enlarged view of section D in FIG. 3, FIG. The figure is a perspective view of a rotary head cylinder device according to a second embodiment of the present invention in recording/reproducing mode, FIG. 7 is a side sectional view thereof, and FIG. 9 is a side sectional view of a conventional rotary head cylinder device in recording/reproducing mode; FIG. 10 is a view taken along the arrow a in the LL cross section shown in FIG. 9; FIG. 11 is a top view in playback mode; 1 is a top view of a conventional rotary head cylinder device and traveling system in a fast forward 7 rewind mode. 2...Magnetic head, 3...Fixed cylinder, 4...
...Magnetic tape, 16...Scanning start phase, 17.
...Scanning end phase, 21...Groove, 40...
・Rotating cylinder, 41...Protrusion part, 43...
・Shape variable member, 44...Cylindrical member, 45・
... Spacer, 25... Pulse generator. Name of agent: Patent attorney Shigetaka Kurino and one other person

Claims (1)

[Scope of Claims] A fixed cylinder that guides a tape-shaped medium, a head for transmitting and receiving signals to and from the tape-shaped medium, a rotary cylinder arranged coaxially and facing the fixed cylinder and to which the head is attached; A rotary head cylinder device comprising: a shape variable means for changing the shape of at least a portion of the outer peripheral cylindrical portion of the rotary cylinder near the head in accordance with a recording/reproducing phase of the head.