JPS63276741A - Rotary head device - Google Patents

Abstract

PURPOSE:To increase working accuracy and to improve productivity by fixing the step part for regulating the traveling position of a tape like recording medium to a stationary drum by forming it in a separate body. CONSTITUTION:A stationary drum main body 2 in comparatively simple shape is made by lathe turning. On the other hand, a step like body 1a for tape regulation is sliced in the thin plate having flexibility after working the upper face of the thick plate like metallic material 1 having really the same thermal expansion coefficient with that of the stationary drum main body 2 in the shape developing the spiral step part shape for tape regulation in a plane to strictly align a reference line 1b to the reference line 2b of the stationary drum main body 2. A tape regulating step part 3a is formed on the stationary drum main body 2 by fixing to the specified position and a stationary drum assembly body 3 is completed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a rotary head device, and in particular to a fixed drum structure thereof.

(Prior Art) Conventionally, in a rotary head device used in, for example, a video tape recorder, when a magnetic recording tape is wound around a drum in a spiral shape at a predetermined angle and run, the running position of the magnetic tape on the drum is controlled. For this purpose, a configuration is used, an example of which is shown in FIGS. 2 and 3.

FIG. 2 is a perspective view of an example of a conventional rotating head device.
5 is a rotating drum (upper drum), 5 is a magnetic head fixed to the rotating drum 4, 7 is a fixed drum (lower drum), 7a is a tape guide step carved on the fixed drum 7, and the magnetic The part where the tape 6 is wrapped is indicated by a broken line.
The figure is a perspective view of the stationary drum 7 alone. θ indicates the angular range in which the magnetic tape 6 is wound.

That is, a stepped portion 7a is provided on the outer peripheral surface of the fixed drum 7 to abut against the edge of the magnetic tape 6 and regulate its running position, and the stepped portion 7a is provided so that the running magnetic tape 6 always comes into contact with the stepped portion 7a. The shape of the tape 6 is tape-shaped, and tape guides and the like are provided near the entrance and exit of the tape 6 to the drum.

[Problem that the invention seeks to solve]

However, in the conventional fixed drum as described above, special machining is required in order to machine the spiral stepped portion 7a for regulating the tape running position with the required high precision during manufacturing. , there were manufacturing difficulties. Furthermore, in the machining of stepped portions, there are problems with the life of the cutting tool, machining time, machining accuracy, etc., which are factors that increase costs.

The present invention has been made in view of the problems of the prior art as described above, and it is an object of the present invention to provide a rotary head device having this type of fixed drum manufacturing with high precision and high productivity.

[Means for solving problems]

Therefore, in the present invention, the tape regulating stepped portion of the fixed drum is formed into a flexible flat thin plate using a material having substantially the same coefficient of thermal expansion as the fixed drum main body in a separate process. The above objective is achieved by forming the drum by fixing it onto a fixed drum main body having a relatively simple shape.

(Function) With the above-described configuration, it is possible to overcome the difficulties in conventional fixed drum machining and obtain a fixed drum with high precision and high productivity.

〔Example〕

The present invention will be explained below based on examples.

FIGS. 1(a), 1(b), and 1(c) are perspective views illustrating the construction of an embodiment of a fixed drum according to the present invention.

(a) shows the fixed drum main body, (b) shows a separate step-shaped body, and (C) shows a fixed drum assembly made up of both (a) and (b).

(Structure/Manufacturing Method) As is clear from the figure, the fixed drum main body 2 shown in FIG. 3(b) can be manufactured by turning as a relatively simple-shaped turning work that does not include a stepped portion for tape regulation.

On the other hand, the step-shaped body 1a for tape regulation in the figure (b)
The upper surface of the thick plate metal material 1, which has substantially the same coefficient of thermal expansion as the fixed drum body 2, is processed into a shape in which the spiral step shape for tape regulation is developed into a flat surface (lower surface reference line 1
(b aligned with the cylindrical lower surface reference line 2b of the fixed drum body 2), and then sliced into flexible thin plate shapes 1a with a wire saw or slicer machine, etc., to a thickness t of approximately 0.1 to 1 mm. Afterwards, as shown in Figure (C), the reference line ib is precisely aligned with the reference line 2b of the fixed drum body 2, and the fixed drum body is fixed by a fixing method such as laser welding, screw fixing, or an appropriate adhesive. 2, and the tape regulating stepped portion 3a is fixed on the fixed drum main body 2.
is formed to complete the fixed drum assembly 3.

Here, since the predetermined winding of the magnetic tape to be wound once on the stepped portion 3a only needs to have an angular range θ,
The same angle of the stepped body 1a is determined thereby. (On the other hand, in the conventional example shown in FIG. 3, the angular range of the integral step portion 7a is set to be much larger than the predetermined range angle θ due to processing.) The construction/manufacturing method allows the stationary drum to be manufactured with high precision and at low cost.

In the above embodiment, a thick plate-shaped metal material l was used to manufacture the step-shaped body 1a, but the material is not limited to this, and for example, a thickness of 0.1 to 1mm
If it is manufactured from a rolled metal plate or the like by press blanking or laser cutting, mass productivity can be further improved.

(Effects of the Invention) As explained above, according to the present invention, the tape regulating stepped portion, which is most difficult to precisely machine in an integrated structure, is formed separately and fixed to a fixed drum body having a relatively simple shape. Since the fixed drum assembly is manufactured using the same method, it is possible to provide a high-precision, low-cost rotary head device.

[Brief explanation of the drawing]

FIGS. 1(a), (b), and (c) are respectively perspective views illustrating the structure of an embodiment of a fixed drum of a rotary head device according to the present invention, and FIG. 2 is an example of a conventional rotary head device. FIG. 3 is a perspective view of the stationary drum in FIG. 2. 1a...Step shape body 2...Fixed tram body 3...Fixed drum assembly 3a...Tape regulation step Applicant: Canon Electronics Co., Ltd. Book f June 1; Fixed by Drum li ~ Ikkou Sake Iga 144
Figure 1

Claims (1)

[Claims] The stepped portion for regulating the running position of the tape-shaped recording medium on the fixed drum on which the rotary head rotates on the outer peripheral surface is made of a flexible flat thin plate made of a material having substantially the same thermal expansion characteristics as the fixed drum main body. A rotary head device, characterized in that it is formed by forming and fixing on the fixed drum body.