Magnetic tape cassette

Abstract

In a magnetic tape cassette, a top end portion of a reel urging plate spring for urging a tape reel is subjected to a surface treatment to prevent from a friction. A distance between a couple of flanges of the tape reel is selected to keep a form of the wound magnetic tape, and to prevent the tape running from being disturbed by the increase of a contact resistance of the tape edges to the flanges. Additionally, positioning portions for positioning the magnetic tape cassette relative to a magnetic tape drive device are formed of a differential resin from the resin of the remaining part of the cassette case. Additionally, at least one of both end faces of each guide roller is surface treated so that the end face is not worn through its contact with the cassette half. Further, an information presenting section for displaying variable information is provided at a location other than label areas of the tape cassette.

Description

[0001] 1. Field of the Invention[0002] The present invention relates to a magnetic tape cassette, particularly, the invention relates to a magnetic tape cassette including an urging plate spring for urging a tape reel, to one including a tape reel in use for a magnetic tape cartridge having reel a hub to be wound with a magnetic tape, to one including a reference positioning means, to one including a guide roller for guiding a magnetic tape, and to one including a cassette case having an information presenting section.[0003] 2. Description of the Related Art[0004] A magnetic tape cassette which effects the recording / playing-back operation with such an arrangement that a magnetic tape wound on a couple of tape reels, while allowing its run, is held within a cassette case, is generally employed in many audio and video devices.[0005] FIG. 3 is an exploded view showing a DVC (digital video cassette), which is one example of the magnetic tape cassette. A magnetic tape cassette 50 include...

AI Technical Summary

Benefits of technology

[0080] If each flange is made of polycarbonate resin containing glass fibers, which is excellent in mechanical strength and heat resistance, it does not happen that the flanges of the tape reel are deformed by a temperature variation during the transportation for the product delivery and a temperature cycle in its long time use. Further, the proper dimensional value of the dimension between the flanges as originally set may be maintained for a long time, from the product delivery. Accordingly, the running stability of the magnetic tape and the form of the winding of the magnetic tape can be kept satisfactory and good for a long time.

Problems solved by technology

Firstly, the tip of the pivot 64 made of cheap resin will be worn away through its contact with the reel urging plate spring 70 to produce cut powder since the rub resistance of the cheap resin is inferior to POM or the like.

The cut powder thus produced will cause drop-out trouble and hinder smooth rotation of the tape reels 60.

This approach, however, does not lead to the cost reduction of the magnetic tape cassette.

Further, in a magnetic tape cassette, such as DVD or 8 mm cassette, in which the diameter of the hub 61 is small, it is difficult to use a separate pivot in manufacturing the tape cassette.

In the servo pattern writer for initially writing servo patterns onto the magnetic tape and the magnetic tape writer for writing / reading data on and from the magnetic tape in the magnetic tape writing system, if the running of the magnetic tape is disturbed above the write head, the writing / reading operation of the servo patterns is erroneous.

As a result, the merit of high density recording is not effectively utilized.

Improvement of an operating accuracy of the tape running system in the magnetic tape writer and the like is not easy.

Further, such an approach frequently brings about increase of the cost to manufacture.

As a result, the tape running is disturbed, and the writing and reading operations of the servo patterns are frequently erroneous.

Particularly, cut powder that is produced at the contact portion at which the positioning member, e.g., positioning pins 300 comes in contact with the reference positioning means, attaches to the tape, to present various problems, such as drop out.

This leads to deterioration of the product quality.

When the transparency of the resin is increased, the mechanical strength and the wear resistance of the resin are likely to be deteriorated because its physical property.

This approach, however, brings about the increase of the cost to manufacture, and the product cost.

The cut powder will cause serious errors, e.g., drop out.

If a material making one of the flanges is different from that making the other, the following problem arises.

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