JPH0519777B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to magnetic recording and reproducing devices, such as video tape recorders and audio tape recorders, and in particular to improvements in the support of fixed cylinders.

[Conventional technology]

A rotary head assembly of a conventional magnetic recording/reproducing apparatus is constructed as shown in FIGS. 5 and 6. Figure 5 is a perspective view, Figure 6 is the line of Figure 5.
FIG. In the figure 1
1 is a magnetic head for recording and reproducing information on a tape-shaped recording medium (magnetic tape) 2 such as a video tape, and is attached to a rotating cylinder 3. 4 is a fixed cylinder equipped with a bearing mechanism 5 that supports the rotary cylinder 3, and has a tape-shaped recording medium 2 on its outer peripheral surface.
It has a recording medium guide section 402 having a lead groove 401 for guiding the movement of the recording medium, and a cylindrical section 403 that holds the bearing mechanism 5. The rotary head assembly of the magnetic recording/reproducing apparatus thus constructed is fixed to the base 6 using screws 7. Reference numeral 8 denotes a rotary transformer that transmits signals without contact between the signal processing device in the fixed part and the magnetic head 2, 801 is the fixed side, and 802 is the rotating side.

The fixed cylinder 4 is easy to process and inexpensive, so it is molded from plastic material, aluminum die casting, or the like. In order to release the recording medium from the mold, the recording medium guide portion 402 should be made less than half a cylinder, that is, less than 180 mm over the area around which the tape-shaped recording medium 2 is wound, according to a patent application filed by the present applicant. This was proposed in 1982-111029 (Japanese Patent Application Laid-open No. 61-269215) before the present application. Also base 6
are made of aluminum die-casting, sheet metal, plastic molding, etc.

[Problem that the invention seeks to solve]

Since the conventional magnetic recording and reproducing device is configured as described above, in order to ensure the accuracy after assembly of the part where the fixed cylinder 4 and the base 6 contact, the shape accuracy and surface roughness of the joint surface where the two contact is It is necessary to finish within a specified range, which requires a lot of time for machining, and since the fixed cylinder 4 and base 6 are made of separate members, in order to join them with the specified strength, it is necessary to screw them together. There was a problem that the number of parts increased due to the need to

This invention was made to solve the problems of the conventional products as described above, and it eliminates the need for machining the joint surface between the fixed cylinder and the base, making it possible to easily manufacture the fixed cylinder and the base with the specified accuracy in a short time. It is an object of the present invention to provide a magnetic recording/reproducing device that can be used in a magnetic recording system and has a small number of parts.

[Means for solving problems]

In the magnetic recording/reproducing device according to the present invention, the recording medium guide portion of the fixed cylinder is formed into a semi-cylindrical shape or less, and the fixed cylinder and the base are integrally molded.

[Effect]

The magnetic recording/reproducing device according to the present invention is formed by integrally molding the fixed cylinder and the base, so that the two are integrated without the need for assembly. Furthermore, by making the recording medium guide part smaller than a semi-cylindrical cylinder, it is possible to avoid the complexity of the mold and the difficulty in mold release caused by integrally molding the fixed cylinder and the base.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4. FIG. 1 is a perspective view showing the rotary head assembly and base of the magnetic recording/reproducing apparatus of the present invention, FIG. 2 is an enlarged sectional view of the main part taken along the line - in FIG. The perspective view and FIG. 4 are cross-sectional views taken along the line - in FIG. 3, and the same or equivalent parts as those of the conventional one are given the same reference numerals and the explanation thereof will be omitted.

In the figure, 4A is a fixed cylinder corresponding to 4 of the conventional one, and has a lead groove 401 and a cylindrical part 403 as in the conventional one, but
The recording medium guide section 402 is based on the above-mentioned patent application No. 111029/1986.
As proposed in the issue, the circumferential shape is less than 180 degrees, that is, less than half a cylinder, and by plastic molding, aluminum die casting, etc.
It is integrally molded with the corresponding base 6A.

By doing this, it is possible to manufacture both the fixed cylinder and the base with a certain level of accuracy without requiring machining of the joint surfaces of the fixed cylinder and base, which was necessary in the past, and the assembly process of joining the two with screws is no longer necessary. This makes it possible to produce larger quantities in a shorter time than before. Furthermore, the screws previously used to connect the fixed cylinder and base are no longer required.
It is also possible to reduce the number of parts.

Furthermore, by making the recording medium guide section 402 less than a semi-cylindrical shape, the fixed cylinder 4A and the base 6A
It is possible to prevent the mold from becoming complicated due to integral molding with the fixed cylinder 4A, and it is also possible to prevent mold release from becoming difficult since the fixed cylinder 4A can be released from the mold in the radial direction.

〔Effect of the invention〕

As described above, according to the present invention, the recording guide portion of the fixed cylinder is made smaller than a semi-cylindrical cylinder, and the fixed cylinder and the base are integrally molded, so that the rotary head assembly has a predetermined accuracy and the number of parts is reduced compared to the conventional method. This has the effect that a small number of magnetic recording/reproducing devices can be easily obtained in a short time and in large quantities at low cost.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a rotary head assembly of a magnetic recording/reproducing apparatus according to an embodiment of the present invention, FIG. 2 is an enlarged sectional view of a main part taken along the line - of FIG. 1, and FIG. 3 is a view similar to that of FIG. FIG. 4 is a sectional view taken along the line - of FIG. 3;
FIG. 5 is a perspective view of a rotary head assembly and base of a conventional magnetic recording/reproducing apparatus, and FIG. 6 is an enlarged sectional view of the main part taken along the line - in FIG. In the figure, 1 is a magnetic head, 2 is a tape-shaped recording medium, 3 is a rotating cylinder, 4A is a fixed cylinder, 402 is a recording medium guide section, 5 is a bearing mechanism,
6A is the base. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A rotary head assembly that includes a rotary cylinder that supports a magnetic head, and a fixed cylinder that has a recording medium guide portion that guides a tape-shaped recording medium on its outer peripheral surface and that rotatably supports the rotary cylinder via a bearing mechanism. and a magnetic recording and reproducing device comprising a base that supports the fixed cylinder, wherein the recording medium guide portion is formed into a semi-cylindrical shape or less, and the fixed cylinder is integrally molded with the base.