JPH07105666A - Method for cleaning magnetic tape and tape cassette provided with cleaning mechanism - Google Patents

Abstract

PURPOSE:To obtain a tape cassette restraining the occurrence of an error as a tape cassette housing a tape capable of recording and reproducing the digital information of a video and music. CONSTITUTION:A cleaning member 2 having a sharp edge at a position where it comes in contact with the surface or the back surface of the magnetic tape 3 traveling in the tape cassette is arranged in the tape cassette housing the magnetic tape. It is arranged so that the sharp edge comes in contact with the magnetic tape 3 at an angle orthogonal to the traveling direction of the magnetic tape, and at a position where it comes in contact therewith preceding a magnetic head 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic tape cleaning method for a tape cassette which houses a magnetic tape capable of recording and reproducing information such as music and images, and a tape cassette with a cleaning mechanism.

[0002]

2. Description of the Related Art As one means of digital recording and reproducing of music and the like, there is recording and reproducing of a digital signal by a fixed magnetic head (hereinafter abbreviated as head). In such a digital recording / reproducing system, it is very important to secure a small error rate in the tape cassette in the sense that the original sound is faithfully reproduced. A major cause of obstruction of faithful recording / reproduction is the problem of dust existing on the surface of the magnetic tape and preventing contact between the magnetic head and the magnetic tape. As a measure against the dust, in the conventional tape cassette, for example, JP-A-5-0
As described in Japanese Patent No. 28706, by closing the head of the tape cassette and the pinch roller insertion window with a shutter, it is possible to prevent dust and the like from entering the cassette case from the outside of the cassette case and a tape guide provided in the tape cassette. It has been proposed to prevent shavings from being generated when sliding on a magnetic tape (hereinafter abbreviated as tape), thereby suppressing an error rate caused by dust or shavings. Further, as in Japanese Patent Laid-Open No. 64-57469, it has been proposed to remove dust adhering to the magnetic tape by a cleaning member composed of an aggregate of flocked monofilaments arranged so as to come into contact with the magnetic tape during running. ing.

Further, in a system in which a magnetic tape is pulled out of a cassette and is run along a running surface on the player side and brought into contact with a rotating magnetic head to mainly perform digital recording and / or digital reproduction of images and the like. In the magnetic tape cassettes used, few concrete examples of cleaning action have been proposed.

[0004]

When digital recording / reproducing is performed with the above-described conventional tape cassette with a shutter, the error rate, which is a measure of the fidelity of digital recording / reproducing of a signal, becomes very unstable, and its dispersion varies. Some of them have a large value of 5 × 10 ⁻³ , and it has been found that this is a fatal defect in product quality in digital recording and reproduction.

As a result of diligent studies on the cause of the problem, the present inventors have found that in the process of manufacturing the tape or the process of inserting the tape into the cassette, fine foreign matter adheres to the surface of the magnetic layer of the tape, which is one of the causes of error rate. It was found to be the cause of. In addition, it was also found that the repeated running of the magnetic tape, which is also commonly used, causes dust from the running shape of the tape deck to be taken into the surface of the magnetic tape and causes the error rate to deteriorate. In order to solve such a problem, a method has been proposed in which a cleaning member that comes into contact with the surface of the magnetic tape while the magnetic tape is running is arranged in the cassette.However, although the error rate can be almost achieved, the cleaning member and the magnetic tape are It has been found that the frictional resistance generated between them must cause a running resistance that is not negligible when the magnetic tape runs, because the sliding must be performed with a contact pressure of a certain level or more. This running resistance causes an increase in power consumption and shortens the usable time in a portable type cassette tape recorder of a battery-driven type, which is a big problem, while it exhibits its original function. Was an obstacle.

An object of the invention is to remove dust adhering to the surface of a magnetic tape which causes an error rate which becomes particularly remarkable in the case of digital recording, and to prevent the error rate from being deteriorated during repeated use. (EN) A cleaning method and a tape cassette with a cleaning function capable of solving all the problems such as an increase in running resistance when running a magnetic tape due to pressure bonding of a cleaning member made of fibers, which cannot be avoided.

An object of the first invention is to provide a magnetic tape cleaning method for realizing reliable recording / reproducing in a magnetic recording / reproducing system using a magnetic tape as a recording medium.

A second object of the present invention is to provide a magnetic tape cassette in a magnetic recording / reproducing system using a magnetic tape as a recording medium, and to provide a specific tape cassette with a cleaning mechanism for realizing reliable recording / reproducing. .

It is an object of the third, fourth, and sixth inventions to provide a tape cassette with a cleaning mechanism that provides a cleaning effect adapted to a target magnetic tape.

A fifth object of the present invention is to provide a tape cassette with a cleaning mechanism capable of further reliably suppressing the occurrence of an error rate.

An object of the seventh invention is to propose a low-cost mass production method of cassettes with a cleaning mechanism.

An object of the eighth and ninth inventions is to provide a highly reliable cleaning member material which can be used repeatedly.

[0013]

Means for Solving the Problems As a result of intensive studies for solving the above problems, when a tape cassette is operated, that is, a surface of a magnetic tape traveling in the cassette is brought into contact with a sharp edge, a conventional non-woven fabric or the like is contacted. We have arrived at a magnetic tape surface cleaning method that is significantly more effective than the cleaning method.

This method is a method for removing dust adhering to the magnetic tape by applying a sharp edge to the surface of the magnetic tape at right angles to the running direction of the magnetic tape.

The increase in running load due to frictional resistance, which cannot be avoided by the conventional non-woven fabric pressing method, is almost the same as the line contact in the solid cleaning member contact method for cleaning with sharp edges of the present invention. Since it is possible to achieve the cleaning action in the form, it can be said that it is a very effective invention since it is hardly seen. The first invention proposes a method for cleaning the surface of the magnetic tape of the tape cassette, which is compatible with the digital recording method as described above.

A second aspect of the present invention embodies a cleaning member having a sharp edge, characterized in that the cleaning member has a V-shaped cross section in the direction along the tape running direction. One or a plurality of magnetic tapes are arranged so as to come into contact with the surface of the tape, and the running magnetic tape surface is rubbed by a sharp edge to remove dust that is on the magnetic tape surface and interferes with normal magnetic recording and reproduction.

A third aspect of the present invention is a concrete example of a cleaning member having a sharp edge. The shape of the cleaning member has a cross section along the tape running direction, one edge being a sharp edge and one edge being a sharp edge. Characterized by an R shape, a single or a plurality of magnetic tapes are arranged so as to contact the surface of the magnetic tape in the cassette, and the running magnetic tape surface is rubbed with a sharp edge to adhere to the magnetic tape surface for normal magnetic recording. It is intended to remove dust that hinders regeneration.

A fourth aspect of the present invention embodies a cleaning member having a sharp edge, in which a concave groove having a sharp edge as a cutting edge is formed in a magnetic tape running direction on a magnetic tape contact surface of a block-shaped cleaning member. The cleaning member is placed in a position to contact the magnetic tape surface in the cassette, and the running magnetic tape surface is formed by the sharp edge of the notch of the concave groove. Rubbing and dust that adheres to the surface of the magnetic tape and interferes with normal magnetic recording and reproduction are intended to be removed.

A fifth aspect of the present invention is a concrete example of a cleaning member having a sharp edge. A concave groove having a sharp edge as a cutting edge is formed in the magnetic tape running direction on a magnetic tape contact surface of a block-shaped cleaning member. One or more are formed in the direction perpendicular to each other, and an adhesive portion is provided at the bottom of the concave groove, and one or more cleaning members are arranged at the position in contact with the surface of the magnetic tape in the cassette. Rubbing the tape surface with the sharp edge of the notch of the concave groove removes dust that adheres to the magnetic tape surface and interferes with normal magnetic recording and reproduction, and at the same time removes the dust removed by the adhesive layer provided at the bottom of the concave groove. It is something that is sure to be captured.

A sixth aspect of the invention embodies a cleaning member having a sharp edge, in which a concave groove having a sharp edge as a cutting edge is formed in the magnetic tape running direction on the magnetic tape contact surface of the block-shaped cleaning member. On the other hand, both edges of the block-shaped cleaning member formed in the direction perpendicular to the magnetic tape running direction are opposite to each other in an R shape, and the cleaning member is placed at a position in contact with the surface of the magnetic tape in the cassette. One or a plurality of magnetic tapes are arranged and the running magnetic tape surface is rubbed by a notched sharp edge of a concave groove to remove dust adhering to the magnetic tape surface and hindering normal magnetic recording and reproduction.

A seventh aspect of the invention is to produce the cleaning member having the specific shape described in the second aspect to the sixth aspect of the invention.
This is achieved at the same time by using the same resin material when the cassette body is formed, which enables easy low-cost production.

In the eighth invention, the cleaning member having the specific shape described in the second invention to the sixth invention is formed of a glass material, and the reliability of the tape cassette with a cleaning mechanism is significantly improved. To do.

In a ninth aspect of the invention, the cleaning member having the specific shape described in the second aspect to the sixth aspect of the invention or a part of the contact portion with the magnetic tape is made of ceramic or a superhard material. It is intended to further improve the reliability of the cleaning effect of a tape cassette with a cleaning mechanism.

[0024]

According to the first aspect of the present invention, a cleaning member block having a sharp edge is used for cleaning when a magnetic tape cassette is used, that is, by contacting the surface of the magnetic tape running in the tape cassette as follows. It is thought that this can be achieved by various actions.

That is, the dust can be pushed away by bringing a sharp edge member having a radius radius smaller than the radius of the dust particles existing on the magnetic tape running in the cassette into contact with the running magnetic tape surface. It is an invention that the magnetic head arranged after the cleaning member can make a normal close contact with the magnetic tape.

Desirably, it is effective that the magnetic tape running opposing surface forming the sharp edge is substantially perpendicular to the magnetic tape surface.

Also, since it is possible to make a line contact with the running magnetic tape at the same time as the excellent cleaning effect, a small frictional resistance can be provided, and an effect that enables stable running can be provided.

A second aspect of the present invention provides a tape cassette with a cleaning mechanism that rationally embodies the cleaning method of the preceding paragraph.

A cleaning member having a V-shaped cross section in the direction of traveling on the surface of the magnetic tape traveling in the cassette is arranged at a position in contact with the surface of the magnetic tape, and a sharp edge portion of the tip is attached to the surface of the magnetic tape. Due to the action of removing dust, the magnetic tape and the magnetic head can come into contact with each other without a gap, and it is possible to provide a tape cassette with a cleaning mechanism that can realize high-quality magnetic recording and reproduction.

A third aspect of the present invention provides a tape cassette with a cleaning mechanism that rationally embodies a cleaning method.

On the surface of the magnetic tape running in the cassette,
A cleaning member, one of which has a sharp edge and the other of which has an R shape in cross section along the traveling direction, is arranged at a position in contact with the surface of the magnetic tape to remove dust adhering to the surface of the magnetic tape at the sharp edge. As a result, the magnetic tape and the magnetic head can be brought into contact with each other without a gap, and it is possible to provide a tape cassette with a cleaning mechanism that can realize high-quality magnetic recording and reproduction.

With this shape, it is possible to increase the contact area with respect to the magnetic tape, and also has an advantageous effect of reducing abrasion damage to the surface of the magnetic tape.

Further, the R shape on one side also has an advantageous effect that the running resistance can be reduced during high speed running of the tape during fast feeding which occurs during normal use of the magnetic tape.

A fourth aspect of the present invention provides a tape cassette with a cleaning mechanism that rationally embodies the cleaning method.

A cleaning member provided with a concave groove having a sharp cutout edge on the surface of the block-shaped member which comes into contact with the surface of the traveling magnetic tape in a direction perpendicular to the traveling direction is brought into contact with the surface of the magnetic tape in the cassette. The magnetic tape and the magnetic head can be brought into contact with each other without any gap by arranging them in a position and removing dust adhering to the surface of the magnetic tape at the sharp edge portion, and it is possible to realize high quality magnetic recording and reproduction. It is possible to provide a tape cassette with a cleaning mechanism.

With this shape, it is possible to increase the contact area with respect to the magnetic tape, and also has an advantageous effect of reducing abrasion damage to the surface of the magnetic tape.

Further, by forming a plurality of concave grooves, cleaning can be performed a plurality of times by a plurality of sharp edges, so that it is possible to provide a tape cassette having a more reliable cleaning mechanism.

A fifth aspect of the present invention provides a tape cassette with a cleaning mechanism that rationally embodies a cleaning method.

A cleaning member having a concave groove having a sharp cutout edge on the surface of the block-shaped member that contacts the surface of the running magnetic tape is formed in contact with the surface of the magnetic tape in the cassette. The cleaning is realized by arranging it in a position and removing the dust adhering to the magnetic tape surface at the sharp edge part,
According to the present invention, it is possible to prevent dust from returning to the magnetic tape again by the action of surely capturing the removed dust by the adhesive provided in the concave groove, and with higher reliability, the magnetic tape and the magnetic head. It is possible to provide a tape cassette with a cleaning mechanism, which makes it possible to make contact with each other without gaps and to realize high-quality magnetic recording and reproduction.

With this shape, a large contact area with respect to the magnetic tape can be obtained, and there is also an advantageous effect that abrasion damage to the surface of the magnetic tape can be reduced.

Further, by forming a plurality of concave grooves, cleaning can be performed a plurality of times by a plurality of sharp edges, so that a tape cassette having a more reliable cleaning mechanism can be provided.

A sixth aspect of the present invention provides a tape cassette with a cleaning mechanism that rationally embodies a cleaning method.

A cleaning member having a recessed groove having a sharp cutout edge in a direction perpendicular to the traveling direction is provided on the surface of the block-shaped member in contact with the surface of the traveling magnetic tape. In a tape cassette with a cleaning mechanism that is placed at a position and removes dust adhering to the surface of the magnetic tape at the sharp edge portion, by making the front and rear edges of the surface of the cleaning member that comes into contact with the magnetic tape into an R shape, running The smooth contact between the magnetic tape surface and the magnetic tape surface allows the magnetic tape and the magnetic head to come into contact with each other without a gap without damaging the surface of the magnetic tape, and high quality magnetic recording / reproducing can be realized. A tape cassette with a cleaning mechanism can be provided.

A seventh aspect of the invention is to produce the cleaning member having the concrete shape described in the second aspect to the sixth aspect of the invention.
The production efficiency can be achieved at the same time with the same resin material when the cassette body is formed, so that low-cost production can be easily performed.

According to an eighth aspect of the present invention, the cleaning member having the specific shape described in the second to sixth aspects is formed of a glass material, and the cleaning mechanism is formed by the excellent wear resistance of the working edge portion made of glass. It is intended to greatly improve the reliability of the attached tape cassette.

A ninth aspect of the invention is to use a ceramic or superhard material for all or part of the cleaning member having the specific shape described in the second to sixth aspects of the invention, so that With the excellent wear resistance of the working edge portion, the reliability of the cleaning effect of the tape cassette with a cleaning mechanism is further improved.

[0047]

EXAMPLES Specific examples of a cassette magnetic tape cleaning method and a tape cassette with a cleaning mechanism to which the present invention is applied will be described below.

First, the tape cassette with a cleaning mechanism of this embodiment will be described with reference to the drawings.

(Embodiment 1) Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings.

In this embodiment, the sharp edge cleaning member 2 having the sharp edge portion 1 shown in FIG. 1 was prepared, and as shown in FIG. 2, the surface of the magnetic tape 3 running in the tape cassette. The magnetic tape was placed so that the sharp edge was in contact with the magnetic tape at a right angle. In this figure, 4 indicates a magnetic recording surface. Reference numeral 5 indicates a fixed magnetic head.

The arrangement is sharp edge cleaning member 2
Needs to be arranged to contact the magnetic head after contacting the magnetic tape. As a result, high-quality signals with very few signal defects due to reliable contact between the magnetic tape surface cleaned by the sharp edge cleaning member 11 and the magnetic head are obtained. Recording and reproduction can be achieved. Of course, it is not limited to the fixed magnetic head system, and it is easy to expect the same effect at the time of recording and reproducing by the rotating head even in a system in which the magnetic tape is pulled out of the cassette and the recording and reproducing are performed by the rotating head. It can be estimated.

At this time, an important point is the angle θ formed by the magnetic tape surface 4 and the sharp edge cleaning member working surface 6.
Is 90 degrees or more. Thereby, an effective cleaning action can be obtained.

Specifically, as shown in FIG. 3, the sharp edge cleaning member 2 of the present invention is mounted on the fixed head type digital audio compact cassette as shown in FIG. The magnetic tape 3 is arranged so as to come into contact with the magnetic recording surface of the magnetic tape 3. In the figure, 7 indicates a cassette half.

The digital audio compact cassette referred to here is an upper case and a lower case which accommodate a magnetic tape and has a plurality of windows on the entire surface, two surfaces parallel to the head insertion direction and a surface perpendicular to the head insertion direction. The U-shaped tape cassette has a shutter that is slidable so as to open and close the windows of the upper and lower cases in a direction connecting the centers of the pair of reel stand insertion openings.

Two sharp edge cleaning members 2 of the present invention are arranged with respect to the magnetic head with the working surface 6 facing outward because the magnetic tape is reciprocally recorded and reproduced.

The sharp edge cleaning member 2 of the present invention is used in the same digital audio compact cassette,
As shown in FIG. 4, even if it is installed between the guide roller 8 and the tension pin 9, the same excellent cleaning effect can be exhibited.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to the drawings.

In this embodiment, as shown in FIG. 5, a sharp edge cleaning member 11 having a sharp edge portion 1 on one side and an R surface 10 on the opposite edge is prepared.
As shown in FIG. 6, the surface of the magnetic tape 3 running in the tape cassette was arranged so that the sharp edge was in contact with the surface of the magnetic tape 3 at right angles to the running direction of the magnetic tape. In this figure, 4 indicates a magnetic recording surface. Reference numeral 5 indicates a fixed magnetic head.

The arrangement of this Example 2 was carried out according to Example 1. Details are omitted because they overlap. Since the cleaning member of the present invention has the R surface at one edge, it is also an advantage of the present invention that damage to the surface of the magnetic tape due to this edge and sliding resistance can be reduced during fast forward running of the magnetic tape.

Since the cleaning member 11 of the present invention has the R surface and can gently realize the first edge sliding with respect to the magnetic tape, it may be a magnetic tape whose surface does not have very high abrasion resistance under some circumstances. Is particularly effective.

The specific arranging method is the same as that of the first embodiment, and since it is redundant, detailed description will be omitted, but a similar excellent cleaning effect can be obtained.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to the drawings.

In this embodiment, as shown in FIG. 7, a single or a plurality of concave grooves 16 are formed on the sliding surface 12 with the magnetic tape.
And a cleaning member 13 characterized in that the magnetic tape sliding surface edge is a sharp edge,
As shown in FIG. 8, this is a method of arranging the surface of the magnetic tape 3 running in the tape cassette so that the sharp edge is in contact with the surface of the magnetic tape 3 at right angles to the running direction of the magnetic tape.

It should be noted that the cross-sectional shape of this groove can be easily estimated to be the same as long as it has an effective opposing surface, and the cross section is not particularly limited to a quadrangle. .

The cleaning member 13 of the present invention has a plurality of sharp edge portions 1 and is characterized in that the cleaning effect on the surface of the magnetic tape can be enhanced. In this figure,
Reference numeral 4 indicates a magnetic recording surface. Reference numeral 5 indicates a fixed magnetic head.

The specific arrangement method was the same as in Example 1. Although the detailed description is omitted because it overlaps, a similar excellent cleaning effect can be obtained as described later.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to the drawings.

In this embodiment, as shown in FIG. 9, a single or a plurality of concave grooves 16 are formed on the sliding surface 12 with the magnetic tape.
The cleaning member 15 is characterized in that the edge 10 that forms the edge and that first opposes in the running direction is the R surface, and the magnetic tape sliding surface side edge 1 of the concave groove is a sharp edge (see FIG. 9). In this method, the sharp edge is in contact with the surface of the magnetic tape 3 running in the tape cassette at right angles to the running direction of the magnetic tape.

The cleaning member 15 of the present invention has a plurality of sharp edge portions 1 and the R surface 10, and can enhance the cleaning effect on the surface of the magnetic tape, and the effect of the R surface reduces sliding damage on the surface of the magnetic tape. The feature is that you can do it. In this figure, 4 indicates a magnetic recording surface. Reference numeral 5 indicates a fixed magnetic head.

It should be noted that the cross-sectional shape of the groove can be easily estimated to be the same as long as it has an effective opposing surface, and the cross-section is not particularly limited to a quadrangle. .

Since the cleaning member 15 of the present invention has the R surface and can gently realize the first edge sliding with respect to the magnetic tape, it may be a magnetic tape whose surface does not have very high abrasion resistance under some circumstances. Is particularly effective.

The specific arranging method was the same as in Example 1. Although the detailed description is omitted because it overlaps, a similar excellent cleaning effect can be obtained as described later.

(Fifth Embodiment) Next, a fifth embodiment of the present invention will be described with reference to the drawings.

In this embodiment, as shown in FIG. 11, a single or a plurality of concave grooves 1 are formed on the sliding surface 12 with the magnetic tape.
6, a magnetic tape sliding surface edge is a sharp edge, and an adhesive layer 17 is added to the groove bottom of the concave groove 16 (see FIG. 1).
As shown in 2), it is a method in which the surface of the magnetic tape 3 running in the tape cassette is arranged so that the sharp edge is in contact with the surface of the magnetic tape 3 at right angles to the running direction of the magnetic tape.

It should be noted that it can be easily presumed that the same effect can be obtained if the cross-sectional shape of the groove has an effective opposing surface, and the cross section is not particularly limited to a quadrangle. .

Since the cleaning member 18 of the present invention has a plurality of sharp edge portions 1 and has an adhesive layer on the groove bottom, dust once removed from the surface of the magnetic tape is surely captured by the adhesive layer 12. The feature is that it does not hinder the recording / reproduction again by returning to the magnetic tape. In this figure, 4 indicates a magnetic recording surface. Reference numeral 5 indicates a fixed magnetic head.

The specific disposing method was the same as in Example 1. Although the detailed description is omitted because it overlaps, a similar excellent cleaning effect can be obtained as described later.

(Embodiment 6) The cleaning members in the embodiments 1 to 5 are made of the same resin material as the cassette case in consideration of the cost of the tape cassette. On the other hand, in this embodiment, instead of the resin material of the above embodiment, a cleaning member having the shape of the above embodiment is formed of glass and mounted in the cassette half as shown in FIG.

The glass material has a characteristic that surface smoothness is easily obtained, and the magnetic tape sliding surface of the cleaning member made of glass hardly damages the magnetic tape surface even after repeated running.

(Embodiment 7) In this embodiment, the cleaning effect can be exerted for a long time.
A ceramic material or super hard metal material with excellent wear resistance is used for the cleaning member.

Although it is not impossible to form the entire cleaning member with a ceramic material or a super hard metal material, in this case, a ceramic material or a super hard metal material is considered as a part which is considered to have a great possibility of cost realization. Was adopted.

Specific processing examples of the cleaning member of the present invention are shown in (FIG. 13) to (FIG. 17). A ceramic material or a super hard metal material 1 having excellent wear resistance is provided on the sharp edge portion 1 which acts to clean the surface of the magnetic tape.
4 was used.

With such a structure, it is possible to provide an excellent cleaning effect for a long time.

Further, according to the present invention, it is possible to provide a cleaning member which is effective even for a magnetic tape whose surface has an increased abrading property under special circumstances.

Next, the effect of the present invention was confirmed by actually recording signals in the above embodiment. The magnetic tape was prepared by the following method.

Co-containing magnetic iron oxide (S _BET 40 m ² / g) 100 parts Vinyl chloride copolymer (-SO ₃ Na group-containing) 10 parts Solvent (methyl ethyl ketone / toluene = 1/1 60 parts) Kneader the above composition in addition was kneaded for 2 hours by adding the polyurethane resin (-SO ₃ Na group-containing) 5 parts solvent (methyl ethyl ketone / toluene = 1/1 200 parts of the composition, was 4 hours and kneaded further by a kneader. then the following composition carbon Black (average particle size 20 mμ) 5 parts Abrasive (alumina average particle size 0.5 μm) 5 parts was added and stirred with a dissolver for 1 hour, then dispersed with a sand grinder (peripheral speed 10 m / s) to obtain a magnetic coating. This magnetic coating is nominally 0.8 microns to 0.1μ
m filter to circulate and filter sequentially for purification.

Furthermore, 6 parts of polyisocyanate (curing agent) 1 part of stearic acid 1 part of dimethyl silicone modified product were added to the above magnetic paint, and after stirring, it was applied on a polyester terephthalate film having a thickness of 10 μm and dried to give a film thickness of 3 μm. Alignment treatment was performed by a solenoid orienting device having a strength of 3000 gauss, followed by drying, followed by treatment similar to a 7-step calender at linear pressure of 350 kg / cm and temperature of 90 ° C. to form a magnetic layer original fabric.

Next, a carbon coating material was prepared according to the following specifications, and a carbon layer was formed on the back surface of the above-mentioned raw fabric.

The method for preparing the carbon paint is as follows. Carbon black (average particle size 20 mμ, DBP oil absorption 70 ml / 100 g) 100 parts Nitrocellulose (H1 / 2) 50 parts Polyester polyurethane 30 parts Solvent (methyl ethyl ketone / toluene = 1/1) 900 parts After ball mill dispersing the above composition Then, 0.2 part of an abrasive (alumina average particle size: 0.2 μm) was added and dispersed by a sand grinder to obtain a carbon coating material. After sufficiently purifying by circulating the filter, 8 parts of polyisocyanate (curing agent) was added to this paint, and a dry film thickness of 0.6 μm was formed on the back surface of the magnetic layer material.
Was coated and dried to obtain a magnetic tape raw fabric. It was cut with a slitter to a width of 3.78 mm to obtain a trial magnetic tape A. This trial magnetic tape A was wound around a tape cassette with a cleaning mechanism of the present invention for 100 m to obtain a measurement sample. The cleaning effect was judged by the error rate when digitally recorded by the fixed head method. A tape cassette having a good cleaning effect can be judged by a low error rate.

The error rate measuring method is as follows. Attach each prototype tape cassette of the present invention to the running deck,
The digital signal was recorded at a tape speed of 4.75 cm / s and a bit rate of 96 kbit / s, and the error rate at the time of reproduction was measured as an error rate. The error rate value is 1 from the point 5 minutes after the end of the magnetic tape.
The error rate value was the average error rate for 0 minutes. Further, the durability of the cleaning effect was judged by recording the above signal, repeating reproduction 100 times, and measuring the error rate after 100 times. Further, the abrasion damage due to the sliding of the cleaning member on the surface of the magnetic tape was qualitatively evaluated by a surface photograph after 100 times of running.
And, the evaluation of the wear resistance of the cleaning member against the wear resistance caused by the composition of the magnetic tape was performed by changing the abrasive amount from 5 parts to 15 parts in the above-mentioned magnetic tape composition used in the present study. A comparative examination was conducted by winding the increased prototype magnetic tape B in a tape cassette with a cleaning function.

The frictional resistance during running of the magnetic tape by the cleaning member was measured by attaching only one cleaning member and inserting a tension pickup between the magnetic head and the tape drive unit by the capstan and pinch roller.

The resistance due to the contact of the magnetic tape with the cleaning member during high speed running was measured and compared with the time from the beginning to the end in the normal fast-forward running mode using the standard running mechanism.

Comparative Example 1 was a cassette tape in which the prototype magnetic tape A was wound around the same cassette as that in which the cleaning member was not added (FIG. 3).

In Comparative Example 2, a cleaning tape made of a non-woven fabric was added at the same place as in FIG. 3 (FIG. 3) to prepare a cassette tape in which the trial magnetic tape A was wound in the same tape cassette.

The cleaning members of Examples 1 to 5 were made of heat-resistant ABS resin and formed integrally with the cassette case.

Table 1 shows the initial error rates of the tape cassettes with a cleaning mechanism of Examples 1 to 7 according to the present invention, as compared with the conventional tape cassettes of Comparative Example 1 and Comparative Example 2. The evaluation results are summarized as to the error rate after 100 times of running, which is a guideline for the durability of the cleaning member after one time of running.

The running test environment was carried out at 23 ° C. and 65%.

[0098]

[Table 1]

According to this (Table 1), the tape cassettes shown in Examples 1 to 5 are comparative examples 1 and 2.
Compared with the above, it is obvious that a sufficient error rate is shown at the initial stage, but it is understood that the error rate level is maintained to some extent even after the endurance.

Further, it can be confirmed that Examples 6 and 7 in which the material for improving the surface property and the abrasion resistance is used for the cleaning member maintain a sufficient error rate even after the durability test.

When a cleaning member is made of a material that improves surface properties and wear resistance, wear on the magnetic tape side may occur. However, (Table 2) changes the wear resistance of the surface of the target magnetic tape. We made a prototype of a tape cassette containing the magnetic tape, and summarized the results of observing the wear of the magnetic tape surface during durable running. The judgment was made qualitatively by taking a photograph with a differential interference microscope.

[0102]

[Table 2]

It can be seen that the prototype magnetic tape A having a small wear resistance on the surface of the magnetic tape is subjected to surface damage by the cleaning member with the material for improving the surface property and the wear resistance.

However, it is understood that the prototype magnetic tape B having a small wear resistance on the surface of the magnetic tape can sufficiently withstand. The error rate at this time was 2.5 × 10 ^−5, which was a sufficiently small value.

As described above, the intended function can be exhibited by selecting the most suitable cleaning member according to the performance of the target magnetic tape.

In particular, the running resistance of the magnetic tape in the tape cassette, which is important in a battery-powered portable type deck, is examined (Table 3), and a comparative example of the embodiment using the cleaning member of the present invention and the conventional cassette is shown. It was shown together. The magnetic tape used was a prototype magnetic tape A.

[0107]

[Table 3]

According to this (Table 3), the tape cassette with the cleaning mechanism of the present invention does not increase in running tension and resistance during high speed running as in Comparative Example 1 which is a conventional tape cassette without a cleaning mechanism. It can be seen that a good tape cassette can be provided.

On the other hand, it can be seen that Comparative Example 2 which is a conventional cleaning method cannot provide a good tape cassette with a large running resistance.

Next, a method of cleaning the surface of the magnetic tape by the sharp edge cleaning member of this embodiment will be described with reference to the drawings.

FIG. 18 schematically shows a state of contact with the magnetic head when dust is present on the magnetic tape. When the magnetic tape 3 runs in the direction of the arrow,
Due to the presence of dust 24 on the magnetic tape, the contact between the magnetic head and the magnetic tape is hindered as shown in the figure, and the gap loss as shown in the above equation is received, and sufficient recording / reproduction is hindered. In order to solve such inconvenient phenomenon,
As shown in (FIG. 19), the inventors have invented to introduce a cleaning member 25 having a sharp edge according to the present invention. An enlarged view of the portion C in the figure is shown in (FIG. 20) and (FIG. 21). For the sake of explanation, (FIG. 20) schematically shows a state where the member 26 having no sharp edge is brought into contact with the magnetic tape surface 4. It will be understood that when there is no sharp edge, the movement of the magnetic tape 3 on the dust 24 causes the member to ride up. A cleaning effect cannot be expected with such a member.

On the other hand, a method of cleaning the surface of the magnetic tape with a cleaning member having a sharp edge, which is the method of the present invention, is shown (FIG. 21).

It can be seen that the dust 24 approaching by the movement of the magnetic tape (FIG. 20) removes the cleaning member by the sharp edge cleaning member 25 without riding on the dust. Therefore, the contact between the magnetic head arranged after the cleaning member and the magnetic tape can be completely realized, so that good magnetic recording / reproduction, which is the object of the present invention, can be achieved.

By such a principle, an effective cleaning method using the sharp edge cleaning member of the present invention can be realized. At the same time, however, this method basically requires that the minimum sharp edge portion is in contact, which hinders the running of the magnetic tape. It is possible to minimize the sliding frictional resistance, and by implementing the present invention, it is possible to provide an excellent magnetic tape cassette particularly compatible with recent digital recording systems.

Further, the cleaning member of the present invention is not limited to the digital audio tape cassette as shown in (FIG. 3) and (FIG. 4), but can be applied to various tape cassettes.

FIG. 22 shows an embodiment in which the sharp edge cleaning member 27 of the present invention is mounted on a conventional audio tape cassette type tape cassette so as to contact the magnetic recording surface side of the magnetic tape.

FIG. 23 shows an example in which the sharp edge cleaning member 27 of the present invention is mounted on a conventional video cassette type tape cassette so as to contact the magnetic recording surface side of the magnetic tape.

FIG. 24 shows an embodiment in which a sharp edge cleaning member 27 of the present invention is attached to a conventional small video cassette type tape cassette so as to be in contact with the magnetic recording surface side of the magnetic tape. FIG. 25 shows an embodiment in which a sharp edge cleaning member 27 of the present invention is attached to a conventional small-sized video cassette type tape cassette so as to be in contact with the back surface of the magnetic tape, which is the back coat layer side.

Further, as shown in FIG. 26, there is also an embodiment in which the sharp edge cleaning member 27 of the present invention is mounted so as to be in contact with both the back surface which is the back coat layer side of the magnetic tape and the magnetic surface. It is possible.

[0120]

As is apparent from the above description, according to the cleaning method of the present invention, the cleaning member having a sharp edge is arranged so as to be in contact with the surface of the magnetic tape in the tape cassette. It is possible to remove dust that hinders the close contact of the magnetic head and achieve normal magnetic recording and reproduction. This method also has a principle that there is no recording / playback defect due to dust generated by the loss of nonwoven fabric fibers found in the conventional cleaning method using a nonwoven fabric, and a tape cassette that can realize excellent recording / playback is realized. can do.

Specifically, it is effective in a digital audio tape cassette in which magnetic recording / reproduction is performed in a fixed head system, and a sufficient error rate can be secured even in recording / reproduction by repeated running.

Further, compared with the conventional tape cassette with a magnetic tape cassette cleaning mechanism of the non-woven fabric contact type, the sharp edge cleaning type tape cassette of the present invention can reduce the contact resistance that hinders the smooth running of the magnetic tape, so that it is particularly useful for batteries. Since the power consumption can be reduced in a portable player that is driven, it is advantageous because it can be used for a long time.

Further, by forming the sharp edge cleaning member in a shape having a flat portion in contact with the magnetic tape, the contact of the magnetic tape can be moderated, and a highly reliable cleaning mechanism which does not damage the surface of the magnetic tape is provided. A tape cassette can be provided.

Further, by forming the rear side edge of the sharp edge of the sharp edge cleaning member into an R shape, a tape cassette with a cleaning mechanism which does not damage the surface of the magnetic tape during high-speed rewinding and has a high reliability is provided. can do.

Further, since a plurality of sharp edges can be formed by providing concave grooves on the magnetic tape contact surface of the sharp edge cleaning member, a more efficient cleaning effect can be obtained.

Further, by providing an adhesive layer in the groove of the concave groove provided in the sharp edge cleaning member, dust once removed from the magnetic tape can be surely captured, and again on the magnetic tape. It is possible to provide a highly reliable tape cassette with a cleaning mechanism that does not come back.

By integrally molding the cleaning member of the present invention with the same resin material as the cassette case, a low-cost tape cassette with a cleaning mechanism can be provided.

By forming the cleaning member of the present invention from a processable glass material having excellent surface smoothness, the magnetic tape surface is not damaged during high-speed rewinding, and a highly reliable cleaning mechanism tape is provided. A cassette can be provided.

Further, by forming the sharp edge portion of the cleaning member of the present invention with a ceramic material or a superhard metal material having excellent wear resistance, the cleaning effect is high and the cleaning effect is not deteriorated even after repeated use. A tape cassette with a mechanism can be provided.

The sharp edge cleaning method according to the present invention is not limited to the tape cassette corresponding to the fixed head method, but the magnetic tape is pulled out of the cassette during operation.
The same magnetic tape surface cleaning effect can be obtained even in a tape cassette corresponding to a system for recording / reproducing with a rotary head.

Further, the sharp edge cleaning method according to the present invention is not limited to the magnetic recording surface for recording / reproducing, but may be provided so as to come into contact with the back coat side provided for smooth running of the magnetic tape. It is possible to remove dust on the surface, prevent dust from being transferred due to rolling, and obtain reliable magnetic recording and reproduction.

[Brief description of drawings]

FIG. 1 is a perspective view of a cleaning member having a shape in which only sharp edges of the present invention are in contact with each other.

FIG. 2 is a conceptual diagram of arrangement of a cleaning member having a shape in which only sharp edges are in contact when the cleaning member functions.

FIG. 3 is a diagram showing an example of application of the sharp edge cleaning member of the present invention to a digital audio tape cassette.

FIG. 4 is a diagram showing an example of application of the sharp edge cleaning member of the present invention to a digital audio tape cassette.

FIG. 5 is a perspective view of a cleaning member according to the present invention having a sharp edge and a rear side edge having an R shape.

FIG. 6 is a conceptual layout diagram of the cleaning member having a sharp edge and a rear edge having an R shape when functioning.

FIG. 7 is a perspective view of a sharp edge cleaning member having a concave groove on the magnetic tape contact surface of the present invention.

FIG. 8 is a layout conceptual diagram when a sharp edge cleaning member having a concave groove on the magnetic tape contact surface functions.

FIG. 9 is a perspective view of a sharp edge cleaning member of the present invention which has a concave groove on the magnetic tape contact surface and whose front and rear edges are R-shaped.

FIG. 10 is a layout conceptual diagram when a sharp edge cleaning member has a concave groove on the magnetic tape contact surface and the front and rear edges of the member are R-shaped.

FIG. 11 is a perspective view of a sharp edge cleaning member having an adhesive layer of the present invention arranged in a concave groove.

FIG. 12 is a layout conceptual diagram when a function of a sharp edge cleaning member in which an adhesive layer is arranged in a concave groove is provided.

FIG. 13 is a perspective view of a sharp edge cleaning member embodiment of the present invention in which a wear resistant material is used for the sharp edge portion of the member.

FIG. 14 is a perspective view of an embodiment of a sharp edge cleaning member of the present invention in which a wear resistant material is used for the sharp edge portion of the member.

FIG. 15 is a perspective view of a sharp edge cleaning member embodiment of the present invention in which a wear resistant material is used for the sharp edge portion of the member.

FIG. 16 is a perspective view of a sharp edge cleaning member embodiment of the present invention in which a wear resistant material is used for the sharp edge portion of the member.

FIG. 17 is a perspective view of a sharp edge cleaning member embodiment of the present invention in which an abrasion resistant material is used for the sharp edge portion of the member.

FIG. 18 is a conceptual diagram of the positional relationship between the magnetic head and the magnetic tape when dust is present on the magnetic tape.

FIG. 19 is a conceptual diagram showing the arrangement of sharp edge members when the cleaning method function of the present invention is used.

FIG. 20 is a conceptual diagram of the operation of a member having no sharp edge.

FIG. 21 is a conceptual diagram of the action of a sharp edge.

FIG. 22 is a plan view of an embodiment of a tape cassette for a fixed head.

FIG. 23 is a plan view of an embodiment of a tape cassette corresponding to a rotary head.

FIG. 24 is a plan view of a small tape cassette embodiment corresponding to a rotary head.

FIG. 25 is a plan view of an embodiment of a small tape cassette for a magnetic tape back-acting rotary head.

FIG. 26 is a plan view of an embodiment of a small tape cassette corresponding to a double-sided rotary head having a magnetic tape rear surface and a magnetic recording surface.

[Explanation of symbols]

1 sharp edge 2 sharp edge cleaning member 3 magnetic tape 4 magnetic recording surface 5 magnetic head 6 cleaning member working surface 7 cassette half 8 guide roll 9 tension pin 10 R surface 11 sharp edge cleaning member having R surface 12 magnetic tape contact surface 13 Concave groove sharp edge cleaning member 14 Wear resistant material 15 Concave groove sharp edge cleaning member having R surface 16 Concave groove 17 Adhesive layer 18 Bottom adhesive grooved concave groove sharp edge cleaning member 19, 20, 21, 22, 23 Cleaning Member Example 24 Dust on Magnetic Tape 25 Sharp Edge Cleaner Member 26 Member without Sharp Edge 27 Sharp Edge Cleaning Member of the Present Invention

Claims (9)

[Claims] 1. A method of cleaning a magnetic tape, characterized in that a sharp edge member disposed in the tape cassette is brought into contact with the surface of the magnetic tape running in the tape cassette to remove dust adhering to the magnetic tape. 2. A tape-shaped magnetic recording medium is wound on a reel or hub with a flange and housed in a case, and the magnetic recording tape runs in a cassette or is pulled out of the case and runs along a running surface of an external player. In a magnetic tape cassette for recording and / or reproducing in contact with a fixed or rotating magnetic head, a member having a sharp edge at the position where it contacts the surface of the magnetic tape running inside the case is attached to the magnetic tape running direction. A tape cassette with a cleaning mechanism characterized by being arranged at orthogonal angles. 3. A cassette in which a cleaning member is arranged at a position in contact with the surface of a magnetic tape running inside a case, wherein one of the cleaning members has a sharp edge shape and the back side has an R shape. A tape cassette with a cleaning mechanism. 4. In a cassette in which a cleaning member is arranged at a position where it contacts the surface of a magnetic tape running inside the case, a concave groove whose edge facing the tape running direction is a sharp edge is formed on the magnetic tape contact surface of the cleaning member. A tape cassette with a cleaning mechanism characterized by having a single or a plurality of. 5. A cassette in which a cleaning member is arranged at a position where it contacts the surface of a magnetic tape running inside the case, and a concave groove having a sharp edge on the magnetic tape contact surface of the cleaning member, the edge facing the tape running direction being a sharp edge. A tape cassette with a cleaning mechanism characterized in that a member having an adhesive layer formed on the bottom of the groove is arranged alone or in plural. 6. A cassette in which a cleaning member is arranged at a position in contact with the surface of a magnetic tape traveling inside the case, and a concave groove having a sharp edge on the magnetic tape contact surface of the cleaning member, the edge facing the tape traveling direction being a sharp edge. A tape cassette with a cleaning mechanism, characterized in that a single member or a plurality of members are formed, and members whose front edges facing each other in the magnetic tape running direction are R-shaped are arranged. 7. The tape cassette with a cleaning mechanism according to claim 2, wherein the cleaning member is made of the same resin material as the cassette case and is formed by integral molding. 8. The tape cassette with a cleaning mechanism according to claim 2, wherein the cleaning member is made of glass. 9. The cleaning mechanism with a cleaning mechanism according to claim 2, wherein the cleaning member is entirely or partially made of a blade material metal such as ceramics or a super hard material in contact with the magnetic tape. Tape cassette.