JP2917490B2 - Magnetic recording / reproducing device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a magnetic recording / reproducing device such as a video tape recorder and a digital audio tape recorder.

[Conventional technology]

FIG. 7 is a view schematically showing a conventional magnetic recording / reproducing apparatus, in which (1) is a drive shaft for driving a magnetic tape (2) in a feed direction, and (3) is a drive shaft (1). A rotating roller that runs with the magnetic tape (2) sandwiched therebetween,
(4) is a rotary cylinder carrying a magnetic head (5),
It is rotatably supported from a fixed cylinder (6) via a center shaft (7).

Next, the operation will be described. By rotating the rotary cylinder (4) rotatably supported by the magnetic head (5), the magnetic tape (2) wound around the rotary cylinder (4) and the fixed cylinder (6) is scanned obliquely. The drive shaft (1) that rotates the tape (2) at the same time as the cylinder rotates
And the rotating roller (3), the tape (2) runs at a constant speed. At this time, an oblique scanning track is formed on the tape (2), and this is continuously repeated. The signal is recorded by supplying the signal to the magnetic head (5), and is reproduced by extracting the signal.

[Problems to be solved by the invention]

Since the conventional magnetic recording / reproducing apparatus is configured as described above, the mechanism for rotating the magnetic head (5) and the mechanism for driving and driving the tape (2) must be separately arranged. There were drawbacks such as a large running system and a complicated tape drive mechanism.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a magnetic recording / reproducing apparatus capable of achieving compactness by using the same assembly of a mechanism for rotating a magnetic head and a mechanism for driving and driving a tape. The purpose is to gain.

[Means for solving the problem]

A magnetic recording / reproducing apparatus according to the present invention has a fixed cylinder having a guide ring on its outer peripheral surface for guiding the running of a magnetic tape, a rotating cylinder rotating around the fixed cylinder, and a guide ring of the fixed cylinder engaged with the fixed cylinder. A head assembly comprising a rotatable and rotatably supported middle cylinder, and a magnetic tape attracted to the middle cylinder by static electricity to be driven.

[Action]

In the present invention, the middle cylinder rotates at a constant speed independently of the rotating cylinder. The static electricity is applied to the surface of the middle cylinder at the portion where the magnetic tape is wound around the middle cylinder to attract the magnetic tape. The magnetic tape is fed forward at a constant speed by the rotation of the middle cylinder. At the end of the winding of the magnetic tape, the static electricity on the surface of the middle cylinder is discharged, and the tape runs away from the cylinder.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to a head assembly shown in FIG. In the figure, (8) is a middle cylinder rotatably supported by a bearing (9) in an outer circumferential guide ring (6a) of a fixed cylinder (6), and (10) is rotatably supported by a bearing (11). The rotary cylinder (4) is fixed by a flange fixed to the central shaft (7). The signals of the magnetic head (5) are drawn out to the fixed cylinder (6) by the rotary transformers (12) fixed to the flange (10) and the fixed cylinder (6), respectively. The magnetic head (5) is rotated through the head base (13) and the rotating cylinder (4).
It is fixed to. A rotor magnet (14) is fixed below the center shaft (7), and a motor is formed with the stator coil (15) below the fixed cylinder (6), and the rotor magnet (14) rotates. The magnetic head (5) rotates. The upper end surface of the guide ring (6a) of the fixed cylinder (6) is helical and guides the lower end of the wound magnetic tape (2).

A low-rotation high-torque motor (16) such as an ultrasonic motor utilizing surface acoustic waves is installed on the lower end surface of the middle cylinder (8) so as to face the fixed cylinder (6). 8) is rotated at a constant speed.

As shown in FIG. 2, in the middle cylinder (8), a plurality of rings (8a) are fixed with an electrostatic insulator (8b) interposed therebetween, so that static electricity can be applied to each ring (8a). . FIG. 3 shows a power supply mechanism, in which projections (6b) and (6c) are provided on the lower surface of the fixed cylinder (6) to fix the terminal plates (17) and (18) respectively. Terminal shoe (17a)
Is fixed by the terminal plate (17), and the terminal shoe (17a) is in sliding contact with the ring (8a) of the middle cylinder (8). The terminal shoe (18a) is fixed by the terminal plate (18), and the ring (8
It is in sliding contact with all of a).

Next, the operation will be described. First, the tape driving principle will be described with reference to FIG. The magnetic tape (2) wound around the cylinder is partially in sliding contact with the middle cylinder (8). For example, negative static electricity is supplied to the terminal board (17),
When the surface of the ring (8a) is charged and the magnetic tape (2) is attracted to the middle cylinder (8), the magnetic tape (2) is sent forward by the rotation of the middle cylinder (8). On the other hand, when the terminal plate (18) is supplied with, for example, positive static electricity to cancel the negative charge of the ring (8a), the magnetic tape (2) is released from being attracted. Alternatively, positive static electricity may be supplied to the guide pins to remove the electric charges charged on the surface of the magnetic tape (2).

Next, the operation of the head assembly will be described. In FIG. 1, the rotating cylinder (4) rotates around the central axis (7) by the rotation of the rotor magnet (12). The magnetic tape (2) is wound around the rotating cylinder (4) and the middle cylinder (8), and the lower edge of the magnetic tape (2) is supported by the upper end surface of the guide ring (6a) of the fixed cylinder (6). The magnetic head (5) slides the magnetic tape (2) obliquely. Since the middle cylinder (8) and the magnetic tape (2) are in contact with each other as described above, the medium is fed forward by the rotation of the middle cylinder (8).

As shown in FIG. 3, the wiring (17
The static electricity is given by b). For example, as shown in FIG. 2, a small negative charge is given to the upper part and a large negative charge is given to the lower part. The slip of the magnetic tape (2) in the vertical direction is improved, and the suction force is increased toward the fixed cylinder (6) to increase the driving force in the tape running direction. The magnetic tape (2) is driven by the rotation of the middle cylinder (8) in the running direction by the electrostatic attraction force. By the way, the middle cylinder (8) is rotated at a constant speed by a high torque motor (16) using a surface acoustic wave such as an ultrasonic motor. At the end of the winding, place the terminal shoe (18
By giving a positive charge or discharging according to a), the electric charge of the middle cylinder (8) is made zero and the attraction force with the magnetic tape (2) is eliminated, and the magnetic tape (2) is moved to the middle cylinder (8). Then, the magnetic tape (2) is further pushed forward. In this manner, both the tape running drive and the diagonal sliding of the magnetic head (5) are enabled by one head assembly.

FIG. 5 shows another embodiment of the present invention, in which a rotary ring (19) in which the rotary cylinder (4) of the above embodiment is thinned.
And an upper fixed cylinder (20). A lever (21) for holding the magnetic tape (2) downward and a support part (22) for supporting the lever (21) are installed in the upper fixed cylinder (20), and the magnetic tape (2) is moved downward by a spring (23). Hold down.

The upper fixed cylinder (20) is fixed to the fixed cylinder (6) by a fixing member (24) as shown in FIG.

In this embodiment, the axial restriction of the magnetic tape (2) is performed in the above-described embodiment, and a fixed cylinder (24) is fixed on a rotating ring (19) having a reduced rotating cylinder (4) by a fixing member (24). An upper fixed cylinder (20) fixed to 6) is provided, and a lever (21) rotatably supported by a support portion (22) installed inside the upper fixed cylinder (20) is a part of the upper fixed cylinder (20). The upper end of the magnetic tape (2) protruding from the hole is regulated by the force of the spring (23), thereby preventing the magnetic tape (2) from running upward due to the rotation of the middle cylinder (8).

〔The invention's effect〕

As described above, according to the present invention, since the tape running drive mechanism is incorporated in the head assembly, the apparatus has a compact and simple structure. In addition, the tape can be driven close to the magnetic head by extending the tape. There are effects such as the ability to prevent a decrease in accuracy that occurs.

[Brief description of the drawings]

FIG. 1 is an axial sectional view of a head assembly showing one embodiment of the present invention, FIGS. 2 and 3 are configuration diagrams of a tape drive unit, FIG. 4 is a diagram for explaining the principle of the present invention, and FIG. 6 and 7 are axial sectional views of a head assembly showing another embodiment of the present invention, and FIG. 7 is a view showing a tape driving mechanism in a conventional apparatus. In the figure, (2) is a magnetic tape, (4) is a rotating cylinder, (5) is a magnetic head, (6) is a fixed cylinder, (6)
a) is the guide ring of the fixed cylinder, (7) is the central axis,
(8) is the middle cylinder, (8a) is the ring of the middle cylinder,
(16) indicates a torque motor, and (17) and (18) indicate terminal plates. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (2)

(57) [Claims] 1. A head assembly capable of running a magnetic tape and magnetically recording / reproducing by a rotary cylinder carrying a magnetic head, wherein the head assembly is provided with a guide ring for guiding the running of the magnetic tape. A fixed cylinder having a surface, a rotating cylinder rotatably supported via a central axis from the fixed cylinder and carrying a magnetic head for recording and reproducing information on and from the magnetic tape, and engaged in a guide ring of the fixed cylinder. A magnetic recording / reproducing apparatus, comprising: a middle cylinder that is rotatably supported so as to be rotatable; and the magnetic tape is attracted to and driven by the middle cylinder by static electricity. 2. The magnetic recording / reproducing apparatus according to claim 1, wherein a static electricity supply terminal and a discharge terminal are provided in the middle cylinder.