JPS6023828Y2 - tape cassette - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a tape cassette in which a pair of reel hubs are rotatably supported within a cassette case, and a magnetic tape is wound from one reel hub to the other. This device has a built-in guide roller device that stabilizes the running of the magnetic tape.

Conventionally, in commonly used tape cassettes, a magnetic tape wound between a pair of reel hubs in a cassette case runs through an opening formed on the front side of the cassette case into which a magnetic head enters, and the magnetic tape is A guide roller device for guiding the running direction of the magnetic tape is provided at each corner on the front side of the cassette case so as to be in sliding contact with the head.

By the way, the guide roller device of the tape cassette which has been generally used in the past and which operates as described above has a structure as shown in FIG.

That is, a support pin 3 is installed from the lower half 2 constituting the cassette case 1 near the front corner of the cassette case 1, and the support pin 3 is a cylindrical cylinder with flanges 4 and 5 formed at both upper and lower ends. A shaped guide roller 6 is rotatably inserted and supported by an upper half 7 to prevent removal.

Furthermore, in order to make the rotation of the guide roller 6 smooth,
A device in which silicone oil having an extremely low viscosity, for example, a viscosity of about 100 CPS, is injected into the gap 8 between the support pin 3 and the guide roller 6 is also used.

And, the support pin 3 planted in the cassette case 1 is
The case 1 is integrally formed with a synthetic resin molded bottom, and the guide roller 6 is also formed with a synthetic resin molded bottom.

Therefore, it is difficult to center the support pin 6 vertically with respect to the cassette case 1, and it is also difficult to form the guide roller 6 with high accuracy in roundness.

Therefore, when configuring the guide roller device 9, it is difficult to obtain a stable rotational state with good dimensional accuracy.

Due to this fact, when running magnetic tape,
Uneven rotation occurs in the rotation period of the guide roller 6, causing wow and flutter, and modulation noise.

Further, the guide roller 6 is fitted into the support pin 3 so as to be freely rotatable, and a slight gap is provided between the upper and lower ends and the lower and upper halves 2 and 7.

Then, as the magnetic tape is wound around the reel hub on the tape supply side, the guide roller 6 moves upward and downward relative to the support pin 3 by the width of the gap as the magnetic tape runs. .

As a result, positional fluctuations and level fluctuations during recording and reproducing become large, and deterioration of recording and reproducing characteristics is unavoidable.

Based on the actual situation of the guide roller device 9 as described above, when the guide roller device 9 is located on the magnetic tape supply side with respect to the magnetic head, if the guide roller 6 is maintained in a state where it does not rotate, uneven rotation and support can be avoided. It is possible to prevent adverse effects on the magnetic tape caused by vertical movement relative to the pin 3.

Therefore, in the present invention, when the guide roller device disposed at each corner on the front side of the cassette case is located on the magnetic tape supply side with respect to the magnetic head, the guide roller does not rotate.
On the other hand, the present invention aims to provide a tape cassette having a guide roller device that allows free rotation when located on the winding side of the magnetic tape.

Therefore, before describing the details of the present invention, the state when a tape cassette is installed in a predetermined tape recorder and the magnetic tape is run at a constant speed will be explained with reference to FIG.

The tape cassette C is installed in a predetermined mounting part of the tape recorder, and the magnetic head 10 is inserted into the tape cassette C through the opening 11 formed on the front side of the cassette case 1 and operated so as to come into sliding contact with the magnetic tape 12. At the same time, the magnetic tape 12 is held between a capstan 13 and a pinch roller 14, which serve as constant-speed driving means for the magnetic tape 12, and is caused to run in the direction of the arrow in the figure.

By running the magnetic tape 12 in the direction shown in FIG. 2, one reel hub 15 side located on the left side in the figure becomes the tape supply side, and the other side located on the right side in the figure becomes the tape supply side.
The hub 16 becomes the tape winding side.

When the magnetic tape 11 is run in such a state as shown in FIG. 2, the tape tension in the guide roller device 9 located near the tape supply side becomes approximately 109.

On the other hand, the tape tension in the idle roller device 9, which is located near the tape winding side, is approximately 30 g.

Therefore, the present invention has a pair of guide roller devices 9 disposed at each corner on both sides of the front side of the cassette case 1.
This structure focuses on the difference in tape tension when 9 is located on the tape supply side and the tape winding side, respectively.

That is, the present invention has a cylindrical shape in which flanges 4 and 5 are formed at both upper and lower ends of a support pin 3 that is installed in the lower half 2 of the cassette case 1, similar to that used in the conventional cassette tape C. The guide roller 6 is rotatably inserted.

Furthermore, the present invention has a pair of support pins 3 as shown in FIG.
A gap 8 formed between each and the guide roller 6
A guide loner device 9 constructed by injecting silicone oil 17 having a viscosity of 50 to 1.200 CPS is disposed at each corner of the front side of the cassette case 1.

When the silicone oil 17 of 500 to 1.200 CPS is injected in this manner, it is necessary to apply a force of 8 to 12 f as shown in FIG. 4 in order to rotate the guide roller 6.

That is, the guide roller 6 will be in an unrotatable state unless a force of 8 to 12 f or more is applied.

When the cassette tape C is mounted on a tape recorder and the magnetic tape 12 is run, the tape tension of the guide roller device 9 on the tape supply side is around 109, so the guide roller 6 in the guide roller device 9 of this device Due to the above-mentioned relationship, there is little or no rotation.

On the other hand, since the tape tension of the guide roller device 9 on the tape winding side is around 30 g, the guide roller 9 of this device rotates freely.

As described above, the guide roller device 9 in the tape cassette C according to the present invention does not rotate when located on the tape supply side, and is free to rotate when located on the tape winding side.

Therefore, in the cassette tape C in which the magnetic tape 12 is reciprocated to record and reproduce data, each of the pair of guide roller devices 9
, 9 are in different operating states when they are on the tape supply side and the tape winding side, respectively.

That is, when the guide roller 6 needs to rotate, it can rotate freely, and when it does not need to rotate, it cannot rotate, and the wow and noise caused by the rotation of the guide roller 6 are prevented.
It is possible to prevent the occurrence of flutter, prevent the occurrence of modulation noise, and suppress phase fluctuations and level fluctuations during recording and reproduction.

That is, according to the present invention, it is possible to provide a tape cassette with extremely good recording and reproducing characteristics.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a guide roller device in a conventional tape cassette. FIG. 2 is a schematic plan view showing the running of a magnetic tape in a tape cassette used to explain the present invention, and FIG. 3 is a sectional view of a guide roller device used in the tape cassette of the present invention. FIG. 4 is a diagram showing the relationship between the viscosity of silicone oil and the force required to rotate the guide roller. 1...Cassette case, 3...Support pin, 6...Guide roller, 9...Guide roller device, 12...Magnetic tape , 17・Song・Silicone oil.

Claims (1)

[Scope of utility model registration request] A tape cassette in which a pair of reel hubs are rotatably supported within the cassette case and magnetic tape is wound from one supply reel hub to the other take-up reel hub, and the cassette case has an opening through which the magnetic head enters. A cylindrical guide roller is inserted into a pair of support pins planted from the cassette case at both corners of the front side, and silicone oil of 500 to 1200 CPS is injected between the support pin and the guide roller, When the magnetic head enters the opening, the guide roller on the supply reel hub side is rendered unrotatable;
A tape cassette characterized in that a guide roller device is provided in which the guide roller between the take-up reel hub and the guide roller is rotatable.