JP2789224B2 - Drum device for information recording and reproduction - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to an information recording / reproducing drum device, and more particularly to a stable, high-precision running of an information recording medium (generally, a magnetic tape, hereinafter referred to as a recording medium). Also, the present invention relates to a drum device suitable for securing a stable contact state between a recording / reproducing head (hereinafter, referred to as a head) and a recording medium.

[Conventional technology]

In the conventional device, the rotating drum and the fixed drum are brought close to each other,
Further, in the information recording / reproducing drum device in which these are arranged coaxially, both the rotating drum and the fixed drum have a cylindrical shape.

Incidentally, a configuration in which the diameter of the rotary drum is increased as the distance from the fixed drum is increased, and the entire shape is tapered is described in Japanese Utility Model Application Laid-Open No. 62-158650.

Similarly, a groove is provided on the rotating drum, and the diameter of the rotating drum is changed for each groove.
It is described in JP-A-30045.

[Problems to be solved by the invention]

However, among the above-mentioned prior arts, when the rotating drum has a normal cylindrical shape, no consideration is given to the point that the force for regulating the recording medium is generated by the rotating drum. There was a problem. Further, in the case of the shape described in Japanese Utility Model Application Laid-Open No. 62-158650, there is a problem that it is difficult to precisely measure the tapered portion when controlling the diameter of the rotating drum, so that the accuracy is reduced. Further, since the head mounting portion is also tapered, it is difficult to measure and adjust the amount of protrusion of the head from the surface of the rotating drum. Furthermore, since an air film is formed between the surface of the rotating drum and the recording medium by the rotation of the rotating drum, the recording medium is deformed into a taper shape larger than the taper of the rotating drum. Therefore, there is a problem that the contact with the head becomes insufficient.

Further, in the case of the shape described in Japanese Utility Model Application Laid-Open No. 61-130045, the diameter of the rotating drum changes stepwise, so that the recording medium comes into contact with the rotating drum at this step, causing damage. There's a problem.

Furthermore, of the above three prior arts, the one that changes the diameter of the rotating drum does not consider the distribution of tension in the width direction of the recording medium wound on the rotating drum. Had a problem.

An object of the present invention is to solve these problems and to provide an information recording / reproducing drum device which can ensure stable and high-precision running of a recording medium and a stable contact state between a recording / reproducing head and a recording medium. I do.

Means for Solving the Problems In order to achieve the above object, the present invention provides a rotating drum having an information recording / reproducing head, a rotating shaft of the rotating drum being concentric with and adjacent to the rotating drum. And a guide post for guiding an information recording medium running around the rotating drum and the outer periphery of the fixed drum, and recording information on the information recording medium by the head or In the information recording / reproducing drum device for reproducing from an information recording medium, the rotating drum has a cylindrical portion on the fixed drum side having the same diameter as a winding surface on which the information recording medium of the fixed drum is wound. And a large-diameter cylindrical portion having a diameter larger than the winding surface on the opposite side, and smoothly recessed in the outer peripheral portion between the same-diameter cylindrical portion and the large-diameter cylindrical portion in the vicinity of the same-diameter cylindrical portion. Concentric with the small diameter part An outer peripheral surface formed of a curved surface having a diameter gradually increasing in a circular shape is formed,
The head is provided on the same diameter cylindrical portion.

A rotating drum having an information recording / reproducing head;
A fixed drum concentric with the rotating shaft of the rotating drum and disposed adjacent to the rotating drum; and a guide post for guiding the information recording medium running around the rotating drum and the outer periphery of the fixed drum. In the information recording / reproducing drum device for recording information on the information recording medium by the head or reproducing the information from the information recording medium, the rotating drum has an information recording medium of the fixed drum on the fixed drum side. It has a cylindrical portion having the same diameter as the winding surface to be wound, and has a large-diameter cylindrical portion having a larger diameter than the winding surface on the side opposite to the fixed drum, and is provided between the same-diameter cylindrical portion and the large-diameter cylindrical portion. The outer peripheral surface of the same-diameter cylindrical portion has a minimum diameter, the large-diameter cylindrical portion has a maximum diameter, the same-diameter cylindrical portion side is convex toward the center, and the large-diameter cylindrical portion side is outwardly convex. Concentrically formed into a smooth curved surface,
The head is provided on the same diameter cylindrical portion.

[Action]

According to the above configuration, since the head mounting surface of the rotating drum has substantially the same diameter as the fixed head, the recording medium smoothly wraps around both drums between the rotating head and the fixed head. It becomes good and can prevent scratches. In addition, by increasing the diameter of the rotating drum on the opposite side of the fixed drum, it is possible to apply a regulating force to the fixed drum side to the recording medium wound around the outer periphery of the drum and running, so that the stable running of the recording medium can be achieved. Can be done.
In particular, the outer peripheral surface of the rotating drum from the same diameter cylindrical part to the large diameter cylindrical part is formed into a smooth concentric circular curved surface by smooth depressions and smooth irregularities, thereby preventing damage to the recording medium Further, the concave portions can reduce the flying height of the recording medium, keep the deformation uniform, and maintain good contact with the head.

〔Example〕

 Hereinafter, the present invention will be described with reference to the drawings.

1 and 2 are reference examples of the present invention. In FIG. 1, the rotating drum 2 is arranged coaxially with the fixed drum 4. The fixed drum 4 is provided on its outer periphery with leads 8 for guiding the recording medium 6 helically.

The rotating drum 2 has a recording drum winding surface of a fixed drum 4.
A cylindrical portion 12 having the same diameter as 10 and a window provided in the cylindrical portion 12
A head 16 protruding only from the tip, a smaller diameter portion 18 than the fixed drum 4, a continuously changing outer peripheral portion 20, and a cylindrical portion 22 larger in diameter than the recording medium winding surface 10 of the fixed drum 4 are provided. is there.

FIG. 2 shows another reference example, in which a plurality of small diameter portions 18 are arranged on a continuously changing outer diameter portion 20 of FIG. In this embodiment, as shown in FIG. 2, a plurality of annular grooves are provided on the outer periphery of the tapered shape. Alternatively, one groove may be provided in a spiral shape. The groove may be provided substantially perpendicular to the traveling direction of the vehicle.

In FIG. 1, the medium 6 is guided by guide posts 24 and 26 and helically wraps around the rotating drum 2 and the fixed drum 4. At this time, it is important that the recording medium 6 travels exactly along the leads 8 provided on the fixed drum 4 in order to record and reproduce information at high density.

Generally, winding a tapered medium around a cone will result in a deformation as shown in FIG. That is, when wound on a cylindrical surface (not shown), the medium is wound in a straight line as indicated by 28. However, when the medium is wound around the conical body 30, the medium is deformed convexly downward as shown in FIG.

This is a form in which the recording medium 6 itself easily follows the leads 8 in FIG. In this way, the recording medium 6 is deformed so as to be convex toward the lead 8, and the guide posts 24, 26
When the recording medium 6 is pushed down to the lead 8 side by the flanges 24A and 26A, the recording medium 6 travels along the lead 8.

Incidentally, the head 16 is arranged close to the fixed drum 4. The amount of protrusion of the head 16 from the outer peripheral surface of the rotary drum 2 has a great effect on the state of contact with the recording medium 6, and therefore needs to be managed with high precision. For this purpose, the portion of the rotary drum 2 where the head 16 is provided has a cylindrical shape with high processing accuracy, and the recording medium winding surface 10
It has the same diameter as. As a result, the recording medium 6 wound around the fixed drum 4 can be smoothly wound around the rotating drum 2 and a good contact state with the head 16 can be maintained.

Furthermore, by arranging a conical outer peripheral portion 20 having a diameter gradually increasing at a position further away from the fixed drum 4 than the same diameter cylindrical portion 12, the recording medium 6 can be pressed against the lead 8 and run. I can do it. The portion where the diameter gradually increases is provided at a width of at least half the width of the rotating drum 2 so that the recording medium 6 wound helically is sufficiently deformed. The opposite side of the rotary drum 2 from the fixed drum 4 is a large-diameter cylindrical portion 22. By making the recording medium 6 cylindrical,
Edge is difficult to contact the rotating drum 2 and is scratched,
Tape vibration can be prevented. Further, the outer diameter dimension can be controlled with high accuracy because of the cylindrical shape.

The same-diameter cylindrical portion provided with the conical outer peripheral portion 20 and the head 16
A small-diameter portion 18 is provided between the small-diameter portion 12. Due to the small diameter portion 18, the formation of an air film is reduced, and the recording medium runs close to the surface of the rotating drum 2. On the fixed drum 4 side, the floating of the medium by the air film is very small. If the floating occurs only on the rotating drum 2 side, the winding of the recording medium 6 around the head 16 is asymmetric in the width direction, and good recording / reproduction cannot be performed. However, by providing the small diameter portion 18 which is an annular groove near the head 16, the recording medium 6 can be wound around the head 16 symmetrically in the width direction of the recording medium 6, and good recording / reproduction can be realized.

Further, when the rotation speed of the rotary drum 2 is large, the flying height of the recording medium 6 becomes larger. Therefore, by providing a plurality of small diameter portions 18 as shown in FIG. You can do it.

In this embodiment, the guide posts 24 and 26 are arranged at an angle to the running of the recording medium 6 at the same time as the diameter of the rotary drum 2 is changed. FIG. 4 (a) shows a state in which the medium is running around the cylindrical drum. In this case, the guide post 24 is disposed at an angle of approximately 90 ° with the traveling direction A of the recording medium 6. However, in this embodiment, as shown in FIG. 4 (b), the guide post 24 is arranged at an angle θ ₂ with respect to the traveling direction A. This θ ₂
Is set to a value substantially equal to or larger than the angle θ ₁ formed by the diameter difference of the outer circumference of the rotary drum 2. The effect of the inclination angle θ ₂ will be described with reference to FIG.

FIG. 5A shows a case where the recording medium 6 is wound around the cylindrical drum 34. In this case, the tension distribution during traveling of the recording medium 6 is substantially uniform as shown in the figure because the guide posts (not shown) are arranged at substantially right angles to the traveling direction. At this time, the recording medium 6 on the cylindrical rotary drum 34 rises largely as shown in the figure, and is slightly in contact with the tip of the head 16.

Next, in FIG. 5 (b), as the rotating drum 2 moves away from the fixed drum 4, the diameter increases. At this time, the guide post (not shown) is substantially perpendicular to the traveling direction as in (a). Then, the tension of the recording medium 6 on the fixed drum 4 side decreases as shown in FIG.
The tension on the upper end side becomes large. Then, the recording medium 6 floats largely on the fixed drum 4 side, and it is difficult to maintain good contact with the head 16.

FIG. 5 (c) shows a case where guide posts (not shown) are inclined on the rotary drum 2 of the present embodiment as shown in FIG. 4 (b). By inclining the guide post, as shown by the tension distribution in the figure, the tension on the head 16 side is increased, whereby the contact between the recording medium 6 and the head 16 is kept good. Further, in the present reference example, the same-diameter cylindrical portion 12 provided with the head 16 is provided.
Since the air around the rotary drum 2 flows into the small-diameter portion 18 which is a groove having a smaller diameter than the groove, the floating of the recording medium 6 is controlled to be small, and good contact between the head and the recording medium becomes possible.

FIG. 6 shows another reference example in which the small diameter portion 18 is a V-shaped groove. The operation and effect are the same as those shown in FIG.

FIG. 7 is a view showing an embodiment of the present invention.
Has a smooth outer periphery. That is, as shown in the figure, the rotating drum 2 has a small-diameter portion 36 in which the outer peripheral surface between the same-diameter cylindrical portion 12 and the large-diameter cylindrical portion 22 is smoothly recessed close to the same-diameter cylindrical portion 12. Then, the surface is connected to the large-diameter cylindrical portion 22 through the outer peripheral portion 38 whose diameter gradually increases.

According to this embodiment, similarly to the above-described reference example, the winding of the recording medium around the head can be improved by the small diameter portion 36.

Further, since the outer peripheral surface has a smooth curved surface, the recording medium is not damaged.

[Effects of the Invention] As described above, according to the present invention, the diameter of the rotary drum increases as the distance from the fixed drum increases, so that the recording medium can be stably and accurately run along the leads. . Further, the floating of the tape on the rotating drum can be controlled by the smooth concave portion on the outer circumferential surface of the rotating drum, and the outer circumferential surface is formed into a smooth curved surface, so that the recording medium can be prevented from being damaged.

[Brief description of the drawings]

FIG. 1 is a front view showing one reference example of the present invention, FIG. 2 is a front view showing another reference example, FIG. 3 is an explanatory view of a recording medium deformation, FIG. FIG. 6 is an explanatory view of a tension distribution, FIG. 6 is a front view showing another reference example, and FIG. 7 is a front view showing an embodiment of the present invention. 2 ... rotating drum, 4 ... fixed drum, 6 ... recording medium, 8 ... lead, 10 ... recording medium winding surface, 12 ... cylindrical part of the same diameter, 16 ... head, 18, 36 ... Small diameter section, 20,38 ……
Outer peripheral part, 22 ... Large diameter cylindrical part, 24, 26 ... Guide post.

Continued on the front page (72) Inventor Nobuyoshi Owada 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Pref.New Media Factory, Hitachi, Ltd. In the factory (56) References JP-A-1-133250 (JP, A) JP-A-2-154354 (JP, A) JP-A-62-154253 (JP, A) JP-A-2-187914 (JP, A) JP-A-63-10312 (JP, A) JP-A-62-36462 (JP, U) JP-A-61-130045 (JP, U) JP-A-62-158650 (JP, U) Field (Int.Cl. ⁶ , DB name) G11B 5/53 G11B 5/52

Claims (2)

(57) [Claims] A rotary drum having an information recording / reproducing head; a fixed drum arranged concentrically with a rotary shaft of the rotary drum and adjacent to the rotary drum; A guide post for guiding an information recording medium running around the outer periphery, wherein the head records information on the information recording medium or reproduces information from the information recording medium by the head; The rotary drum has, on the fixed drum side, a cylindrical portion having the same diameter as the winding surface on which the information recording medium of the fixed drum is wound, and a large-diameter cylinder having a diameter larger than the winding surface on the opposite side to the fixed drum. A small-diameter portion smoothly recessed in the vicinity of the same-diameter cylindrical portion on the outer peripheral portion between the same-diameter cylindrical portion and the large-diameter cylindrical portion, and sequentially increase in diameter concentrically from the small-diameter portion. The outer peripheral surface composed of curved surfaces An information recording / reproducing drum device formed and provided with the head in the same diameter cylindrical portion. 2. A rotary drum having an information recording / reproducing head, a fixed drum concentric with a rotary shaft of the rotary drum and disposed adjacent to the rotary drum; A guide post for guiding an information recording medium running around the outer periphery, wherein the head records information on the information recording medium or reproduces information from the information recording medium by the head; The rotary drum has, on the fixed drum side, a cylindrical portion having the same diameter as the winding surface on which the information recording medium of the fixed drum is wound, and a large-diameter cylinder having a diameter larger than the winding surface on the opposite side to the fixed drum. The outer peripheral surface between the same-diameter cylindrical portion and the large-diameter cylindrical portion has a minimum diameter of the same-diameter cylindrical portion, a maximum diameter of the large-diameter cylindrical portion, and has the same-diameter cylindrical portion side. The large-diameter cylindrical portion is convex outward in the center direction. An information recording / reproducing drum device characterized in that it is formed in a concentric, smooth curved surface, and is provided with the head in the cylindrical portion having the same diameter.