Tap cassette

<img file="NL1000577C2_D0001.tif" />

Office for Industrial Property The Netherlands © 1000577 © C OCTROOI²⁰ © Patent application: 1000577 © Filed: 15.06.95 © Int.CI.⁶

G11B23 / 087

<td>©) Priority:</td><td>© Patent holder (s):</td>

<td>17.06.94 JP 13561994</td><td>Matsushita Electric Industrial Co., Ltd. in Kadoma, Japan (JP).</td>

<td>© Registered:</td><td rowspan="2">© Inventor (s): Hldeki Okumura in Neyagawa (JP)</td>

<td>18.12.95 IE 96/03</td>

<td>@ Date:</td><td>Kazunori Sakamoto in Katano (JP)</td>

<td> 21.08.97</td><td>Kiyoshi Kobata at Takatsuki (JP) Kazunori Kubota in Neyagawa (JP)</td>

<td>(45) Issued:</td><td rowspan="2">© Authorized representative: Ir. PN Hoorweg cs at 2517 GK The Hague.</td>

<td>01.10.97 IE 97/10</td>

(54) Tape cassette with minimized ripple zones.

The present invention relates to a tape cassette, comprising: a pair of wheels, each containing a wheel hub with an anchor groove formed in the outer surface along its circumference such that this anchor groove extends in the longitudinal direction of the wheel; a substantially elongated clamping piece received in the anchor groove and having a predetermined width measured along the circumference of the wheel hub; a tape medium containing a finite length magnetic recording tape with opposite ends; and a starting tape connected to each of the opposite ends of the finite magnetic recording tape by tape welding tape of a predetermined length, one end of the starting tape spaced from the finite magnetic recording tape in the wheel hub and anchored to the wheel hub by of the clamping piece, which is clamped in the anchor groove. The tire sealing tape is positioned radially outwardly and directly above the clamping piece and encloses the predetermined width of the clamping piece when the tape medium is wound around the wheel hub.

NL C 1000577

The contents of this patent correspond to the original filed description with claim (s) and any drawings.

Tape cassette with minimized ripple zones

The present invention relates to a tape cassette, which contains a finite length audio and / or video recording tape and more particularly wheels, which are used in the tape cassette to anchor opposite ends of the finite length recording tape.

A tape cassette, containing a finite audio and / or video recording tape, in particular a finite recording tape for digital audio signals, comprises an approximately box-shaped housing and a first and a second wheel, the wheels being rotatable and spaced apart in the house. Of the finite audio tape, the opposite ends are each attached to one of the wheels, part of the recording tape being between the opposite ends wrapped around the wheels. The wheels are usually identically constructed and each includes an approximately cylindrical hub, the opposite ends of which have radially projecting wheel flanges.

Usually, connection of each end of the finite recording tape to an associated wheel is accomplished using a length of starting tape. In turn, one end of the starting tape is inseparably connected to the finite recording tape by means of an elongated tape welding member, which is substantially the same width as the recording tape, the other end of which is fixedly connected to the wheel hub. The above will refer below to Fig. 2 be described in detail.

Fig. 2 shows a cross-sectional view of a substantially cylindrical wheel hub 1, the section taken along a line perpendicular to the longitudinal axis of such a wheel hub 1. The wheel hub 1 is provided with a longitudinal anchor groove 1a formed therein such that it extends in the longitudinal direction of the wheel hub 1 and is set back in the radial direction around a substantially elongated clamping piece 2 having the shape of

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to incorporate the anchor groove la complementary form. A tape medium comprises a finite length of magnetic recording tape 5, the opposite ends of which are connected to the starting tape 3 by means of a tape welding tape 4. An inner end of a starting tape 3 at each end of the finite magnetic recording tape 5 is received in the anchor groove 1a and is secured here by means of the clamping piece 2, which is clamped in such an anchor groove 1a in order to fix the starting tape 3 in this way to the hub 1.

When the inner end of the starting band 3 is attached to the hub 1 as described above, the starting band 3 emerges from a very narrow gap between one longitudinal side edge of the clamping piece 2 and one longitudinal edge of the one on this one longitudinal side edge of the clamping piece 2 connect the anchor groove 1 from the anchor groove 1a before this starting tape 3 is wound in one direction around the hub 1 in order to form a tape roll wound on the corresponding wheel. The starting tire is therefore sharply bent at the point where it emerges from the very narrow gap in the hub 1 and is wound in one direction around the hub 1, resulting in a boiling indicated as 3a, which can be regarded as a disturbance of the line of the surface, which is present on the outer circumferential surface of the hub 1. This boiling 3a in turn results in an indentation of the surface on the other side of the point where the starting tire 3 emerges from the wheel hub 1, then the side where the boiling is located.

As is well known to those skilled in the art, on the other hand, the tape medium in the tape cassette moves from a first wheel to a second wheel at relatively high speed during operation after it has been pulled from a tape roll wound around the hub of the first wheel, a tape roll having an increasing diameter is formed around the hub of the second wheel. However, before the tape cassette is first used to record or play information on or from the finite magnetic recording tape 5, the tape medium is wrapped tightly around one of the wheels for a considerable period of time, stored unused under

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varying conditions of temperature and humidity.

A similar condition may occur when a one-time tape cassette used for information recording or playback is not used for a considerable length of time, with the tape medium wrapped partly tightly around the hub of the first wheel and partly around the hub of the second wheel or wherein the entire length of the tire is wrapped around the hub of one of the wheels.

When one of the wheels is considered, in which a roll of tire medium is wrapped tightly around its hub, some windings of the tire medium wound around the wheel near the hub show a so-called wrinkle zone, which is the phenomenon in which the indentation caused by the boiling 3a in the surface of the starting tape 3, as described above, leaves a wavy mark on the parts of the inner tape turns of the roll, radially aligned with boiling 3a. This is especially the case when the band roll tightly wrapped around the hub is stored for a considerable period of time at a high temperature and / or in an environment containing a high degree of humidity. Once a tape medium exhibits ripple zones, this tape medium, when viewed as a straight and flat object, has an end portion near the hub that exhibits a succession of wavy markings at approximately regular intervals corresponding to the length of each tape wrap.

Although the starting tape 3, like the tape splicing tape 4 and the clamping piece 2, has a fixed length with a certain amount of play in accordance with the standard laid down for a specific type of tape cassette, the starting tape 3 is generally long enough to wrap around the hub several times. be wrapped. Therefore, the starting tape 3 and a considerable length of the inner end portion of the finite magnetic recording tape 5 have wavy marks.

The presence of the ripple zones, that is, the presence of the wavy markings, causes significant problems in the event that the finite magneti1000577.

recording tape 5 is of the type known as digital audio tape (DAT) or as digital compact cassette tape (DCC) and is used for recording or playing back digital information. This is because the distance between the head and tape fluctuates when these parts of the finite magnetic recording tape 5, where wavy marks have been formed, move past an information recording and / or reproducing head, resulting in signal dropout and / or increase the error rate. When this takes place, for example, listening to music-shaped information recorded on the magnetic tape would be unpleasant.

In order to avoid or minimize the occurrence of the ripple zones in the tape medium, several possibilities have been proposed to date. The Japanese utility model laid open to public inspection with no. For example, 62-61079, published April 15, 1987, describes a connection between the finite magnetic recording tape and the cleaning tape, which are secured together by a tape welding tape, which in turn, together with a winding of the film directly below cleaning tape is provided in a longitudinal groove formed in the hub.

The Japanese utility model laid open to public inspection with no. 62-61082, published April 15, 1987, discloses the use of a complicated shaped clamping piece with a curved outer surface, which is radially recessed inwardly into the hub to accommodate the thickness of the tape weld tape therein when the clamping piece is included in the complementary shaped anchor groove in the hub to clamp one end of a starting band or a cleaning band, the tape welding tape being used to connect the starting tape or the cleaning tape to the finite magnetic recording tape. According to this publication, the tape weld tape shown has a substantially the same length as the width of the clamping piece measured in a direction corresponding to the circumference of the hub.

The Japanese Utility Model Laid-Open No. 1-140614 published September 26, 1989,

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describes a starting tape and a finite magnetic recording tape, which are attached together end-to-end by means of an adhesive tape of a length corresponding to the circumference of the hub. This publication does not describe the connection between the starting tire and the hub. Reference is made here to the fact that the adhesive tape used according to this publication is too long to meet the standard.

Japanese Laid-Open Utility Model No. 2-42276, published March 23, 1990, discloses the use of a starting tape wound several times around the hub, with at least an intermediate portion of the starting tape being adhered to the foregoing winding of the starting tape is attached.

Japanese Laid-Open Utility Model No. 2-80386, published June 20, 1990, discloses the use of one or more wraps around the hub, with the overlapping wraps of the starting tape being together attached by means of at least one piece of double-sided adhesive tape.

Japanese Patent Laid-Open No. 3-269888, published December 2, 1991, describes the use of a clamping piece, the thickness of which is reduced by an amount corresponding to the thickness of a starting tape, so that an outer curved surface of the clamp is radially inwardly recessed from the outer circumference of the hub when the clamp is received in the anchor groove of the hub.

Japanese Laid-Open Patent Publication No. 4-67378, published March 3, 1992, describes a connection between a starting tape and a finite magnetic recording tape by means of a tape sealing tape. The tape welding tape used here has such a length selected that the tape welding tape is above the clamping piece and is enclosed by the width of the clamping piece when the tape medium is wound around the hub. This publication also describes a clamping piece, the thickness of which is reduced by an amount corresponding to the thickness of the initial tire, such that an outer curved surface of the clamping piece is radially inwardly recessed relative to the outer circumference of the hub when the clamping piece is in the anchor groove is included, to create space for the thickness of the strip welding tape.

Japanese Laid-Open Patent Publication No. 5-109234, published April 30, 1993, describes the use of a tire sealing tape having a length consistent with the circumference of the hub used so that opposite ends of the tape sealing tape cannot overlap when the tape medium is wrapped around the hub, but will occupy adjacent positions. However, reference is made here to the fact that the strip weld tape used according to this publication is so long that it does not meet the standard.

Other publications of specific interest include U.S. Patents Nos. 3,856,228, Nos. 4,136,843, and Nos. 3,797,777, which all relate to tire wheels, but are not intended to minimize the ripple zones that occur in the tire medium.

All approaches known to date to the problem of the ripple zones have been found to be insufficient in minimizing them. In particular, it is noted that when a tape weld tape of less length than the width of the clamping piece is used, as described in Japanese Patent Laid-Open Publication No. 4-67378, accurate positioning of the tape weld tape while wrapping the tape medium around a tape wheel is required to allow the tape seal tape to be contained within the width of the clamping piece. This can be easily accomplished during a laboratory experiment, but it cannot be accomplished without difficulty in mass production. As soon as the tape has been moved so that it is outside the width of the clamping piece, wrinkle zones are likely to occur.

The present invention therefore has the primary object of providing an improved tape cassette, in which the wheel hub is designed to receive 100057.

standing of ripple zones in the tape cassette is minimized or substantially eliminated.

In order to accomplish the above and other objects and features of the present invention, in accordance with a feature of the present invention there is provided a tape cassette comprising: a pair of wheels, each of which has a wheel hub with an anchor groove formed in the outer surface along its periphery that this anchor groove extends in a longitudinal direction of the wheel; a substantially elongated clamping piece received in the anchor groove and having a predetermined width measured along the circumference of the wheel hub; a tape medium comprising a finite length magnetic recording tape with opposite ends; and by means of a tape welding tape of a predetermined length connected to each of the opposite ends of the finite magnetic recording tape, one end of the starting tape spaced from the finite magnetic recording tape in the wheel hub and anchored to the wheel hub by means of the clamping piece, which is clamped in the anchor groove. The tire sealing tape is positioned radially outwardly and directly above the clamping piece and encloses the predetermined width of the clamping piece when the tape medium is wound around the wheel hub.

In accordance with the present invention, the thickness of the tape welding tape fills the indentation in the surface, which indentation is formed by the presence of the boiling created by the narrow gap between one longitudinal side edge of the clamping piece and one longitudinal edge of the anchor groove in the wheel hub outwardly emerging starting tire. As a result, formation of the ripple zones described above is minimized and therefore the chance of errors is minimized advantageously, the error frequency would increase if the tape cassette were stored under the harmful conditions such as high temperature and high humidity.

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In particular, the selection of the length of the tape weld band to a value sufficient to include the width of the clamping piece, i.e. a value greater than the width of the clamping piece, allows the tape welding tape to cover the clamping piece at all times as long as the tape medium is wound around the wheel hub, even if the tape weld tape has moved slightly in one direction along the circumference of the wheel hub relative to the clamping piece. This property allows the cassette of the present invention to be mass-produced.

The present invention is applicable to all known types of tape cassette, such as, for example, those containing a finite length of tape suitable for recording audio signals, but the present invention can be used with particular advantage in a tape cassette of audio type suitable, wherein within the standard it is possible for the strip welding strip to have a sufficiently larger length than the width of the clamping piece.

When considering a tape cassette suitable for use in a digital information recording and / or reproducing device, such as, for example, a DCC or DAT device, the presence of the ripple zones is highly problematic, because it causes deterioration of the SER (signal error rate) occurs, which can result in reproduction of only unpleasant information to be listened to, and the quality of the tape cassette will therefore be reduced. It has been found that the present invention is of particular utility here.

As is well known to those skilled in the art, the ripple zones are of particular importance and therefore deterioration of the SER is significant when the tape medium has a relatively small thickness. In a tape cassette, according to the present invention, in which the tape seal tape is positioned radially outwardly and directly above the clamping piece and its width, wrinkle zones will form in a tape medium of less thickness than

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μτη, which is suitable for long-term recording or reproduction, is also advantageously minimized.

Although the use of the tape sealing tape in the form of a known non-magnetic polymer-containing film applied to one surface thereof with an adhesive may be sufficient to minimize the wrinkle zones, use is preferably made of a tape sealing tape in the form of a film containing a non-magnetic polymer, wherein a metal-containing thin film is applied to one surface thereof by any known vacuum deposition technique, and also an adhesive-containing layer is formed thereon to further minimize the wrinkle zones.

Alternatively, in a preferred embodiment, the starting tape may be in the form of a non-magnetic polymer-containing film applied to one surface thereof with a metal film thin film applied to it by any known vacuum deposition technique, as is the case with the tape sealing tape, wherein a metal-containing thin film is formed on its surface.

These and other objects and features of the present invention will be made apparent from the following description, which has been made in conjunction with a preferred embodiment of the invention, referring to the accompanying drawings, which designate like parts with like reference numerals , and in which:

Fig. 1 shows a schematic cross-sectional view of a hub according to the present invention used in a tire wheel, showing a tire medium wound around it;

Fig. 2 shows a similar view to Fig. 1 and shows a tire wheel according to the known art;

Fig. 3a shows a graph of the error frequency measured for five minutes at an elevated rate

100057 / temperature during reproduction of information from one of the two recording sides of a finite magnetic recording tape wrapped around the tape wheel of the present invention;

Fig. 3b shows a graph of the error frequency measured for five minutes under the same conditions during reproduction of information from the other of the two recording sides of a finite magnetic recording tape;

Fig. 4a shows a graph of the error frequency measured for five minutes at an elevated temperature during reproduction of information from one of the two recording sides of a finite magnetic recording tape; and FIG. 4b shows a graph of the error frequency measured for five minutes under the same conditions during reproduction of information from the other of the two recording sides of a finite magnetic recording tape.

Referring to Fig. 1, it is noted that the wheel hub 1 shown here may have an identical structure to the wheel hub shown in Fig. 2. As is the case in the prior art, shown in Fig. 2 and described with reference to it, the tape medium wound around the wheel hub 1 contains a finite magnetic recording tape 5, the opposite ends of which are connected by a tape welding tape 4 to a starting tape 3. An inner end of the starting tape 3 at each end of the finite magnetic recording tape 5 is received in the anchor groove 1a and secured in place by means of the clamping piece 2, which is clamped in the anchor groove 1a to thus fix the starting tape 3 to the wheel hub 1. The starting tape 3 used in the practice of the present invention has such a selected length that the tape welding tape 4 with a length b, which is greater than the width a of the clamping piece 2, is located above the clamping piece 2 and encloses the width thereof, when the tire medium is wrapped tightly around the wheel hub 1.

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In accordance with the standardized specifications of the tire of a digital compact cassette (DCC), the outer diameter of the wheel hub 1 is 20 mm, the width of the clamping piece 2 is 9 mm in a direction along the circumference of the wheel hub 1, the thickness of the tape welding tape 4 is 10 μτη and its length is 16 mm, the thickness of the starting tape 3 is 15 μm and the thickness of the finite magnetic recording tape 5 is 13 μτη. Under these conditions, the starting tape 3 used in the practice of the present invention has a length selected in accordance with the following formula:

outer diameter of the hub x π x 6 turns x the width of the clamping piece / 2, where π represents the ratio between the circumference of the wheel hub 1 and its outer diameter.

When this formula is applied to the standardized specifications of the tape of a digital compact cassette, it follows that the starting tape 3 has a length of 372 mm. When the wheel hub 1 used in the practice of the present invention has an outer diameter of 20 mm, the clamping piece 2 having a width of 9 mm is used to anchor one end of the starting band 3 having a thickness of 15 μm, and the tape welding tape 4 with a thickness of 10 μτη and a length of 16 mm is used to connect the starting tape 3 and the finite magnetic recording tape 5 with a thickness of 13 μτη, the composition can be put in a position, which lies radially outside of the clamping piece 2 and encloses its width when the such starting tape 3 with a length of 372 mm is wound six times around the wheel hub 1.

The present invention will be described in more detail below by way of examples.

Example 1

A commercially available DCC tape with a width of 3.78 mm, a thickness of 12.5 μητ and a length of 134 mm is wound together with the tape welding tape on the wheel hub, which tape welding tape relative to the clamping piece in accordance with the present invention is positioned as shown in Fig. 1. The tape medium became round

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wrapped the wheel hub using a commercially available tape deck for this purpose after the tape had been played in the PLAY mode. Then, the tape cassette was placed in an environment with a temperature of 70 ° C and a relative humidity of 20% for six hours, and then the SER (signal error rate) was measured using a commercially available device for measuring the error rate (DEMS 2000, manufactured by Philips, Japan). During the measurement of the SER, the signal was recorded on one end portion of the B side of the DCC tire near the wheel hub (which end portion is referred to as the B top) and the signal on an end portion of the A side of the DCC tire. tire near the same wheel hub (which end portion is referred to as the A end) reproduced the recorded signal for five minutes.

Example 2

A similar measurement of the SER of the signals at the B-top and A-end of a DCC tape was performed under the same conditions as those described in Example 1 using a tape cassette, which was similar to that used in Example 1. Only, the tape seal tape was made of a non-magnetic tape base of a polymer-containing film to which aluminum was applied to a thickness of approximately 500 angstroms.

Example 3

A similar measurement of the SER of the signals at the B-top and A-end of a DCC tape was performed under the same conditions as those described in Example 1 using a tape cassette, which was similar to that used in Example 1. Only the starting tape was made of a non-magnetic tape base of a polymer-containing film to which aluminum was applied to a thickness of approximately 500 angstroms.

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Example 4

A similar measurement of the SER of the signals at the B-top and A-end of a DCC tape was performed under the same conditions as those described in Example 1 using a tape cassette, which was similar to that used in Example 1. Only the thickness of the DCC tape used here was 9.5 µm.

Equation 1

A similar measurement of the SER of the signals at the B-top and A-end of a DCC tape was performed under the same conditions as those described in Example 1 using a tape cassette, wherein the tape sealing tape as shown in Fig. 2 was positioned and displaced relative to the clamping piece.

Equation 2

A similar measurement of the SER of the signals at the B-top and A-ends of a DCC tape was performed under the same conditions as those described in Example 1 using a tape cassette, of which the tape weld tape had a shorter length than the width of the clamping piece.

The following table gives the mean value of the SER (the SER for the B top and A end summed and divided by 2), the mean CF (critical frame number) and the mean C2HF (the C2 hard flag number), which were measured at moments before and after each of the tape cassettes described in Examples 1 to 4 and in Equations 1 and 2 was exposed to the conditions specified above. The terms before and after used in the table indicate the moments before and after each of the tape cassettes described in Examples 1 to 4 and in Equations 1 and 2 was exposed to the conditions specified above.

In the table, the term C2HF denotes the occurrence of errors, which cannot be corrected and which are a cause of the incorrect reproduction of information,

10005 //, which makes listening to it unpleasant. The term CF refers to the number of frames in which correctable errors have occurred, and refers to an increased number of frames containing errors, which may lead to reproduction of information whose listening is unpleasant, although not yet the case.

Table

<td rowspan="3"></td><td colspan="6">B top</td><td colspan="6">A-top</td>

<td colspan="3">in front of</td><td colspan="3">after</td><td colspan="3">in front of</td><td colspan="3">after</td>

<td>SBR</td><td>CF</td><td>C2HF</td><td>SBR</td><td>CF</td><td>C2HF</td><td>SER</td><td>CF</td><td>C2HF</td><td>SBR</td><td>CF</td><td>C2HF</td>

<td>Vbl</td><td> 0, 54</td><td> 0</td><td> 0</td><td> 3,02</td><td> 10</td><td> 0</td><td> 0,38</td><td> 0</td><td> 0</td><td> 2,92</td><td> 12</td><td> 0</td>

<td>Ex 2</td><td> 0,37</td><td> 0</td><td> 0</td><td> 1,71</td><td> 5</td><td> 0</td><td> 0,41</td><td> 1</td><td> 0</td><td> 1, 86</td><td> 6</td><td> 0</td>

<td>Ex 3</td><td> 0,27</td><td> 0</td><td> 0</td><td> 2,71</td><td> 7</td><td> 0</td><td> 0, 50</td><td> 1</td><td> 0</td><td> 2,16</td><td> 8</td><td> 0</td>

<td>Ex 4</td><td> 0,18</td><td> 1</td><td> 0</td><td> 3,35</td><td> 13</td><td> 0</td><td> 0,27</td><td> 0</td><td> 0</td><td> 3,05</td><td> 18</td><td> 0</td>

<td>Verg. 1</td><td> 0,29</td><td> 0</td><td> 0</td><td> 55,28</td><td> 173</td><td> 6</td><td> 0,65</td><td> 1</td><td> 0</td><td> 46,43</td><td> 162</td><td> 0</td>

<td>Compare 2</td><td> 0,61</td><td> 0</td><td> 0</td><td> 29,88</td><td> 145</td><td> 4</td><td> 0,39</td><td> 1</td><td> 0</td><td> 32,91</td><td> 158</td><td> 0</td>

As shown in the table above, such positioning of the tape splice 4 with a length greater than the width of the clamping piece 2 results, this tape splice 4 lying radially outside the clamping piece 2 and enclosing its width when the tape medium is around the wheel hub 1 is wound in accordance with the present invention, to the advantage that the SER is hardly affected, as can be seen from the table in examples 1 to 3, even after the tape cassette has been subjected to the damaging conditions of high temperature and high humidity for a considerable period of time, that the CF is low and no signal dropout (C2HF) occurs, which is critical to the quality of the tape . While the present invention functions satisfactorily, the use of the tape sealing tape on which an aluminum layer has been applied, as in Example 2, or the use of the starting tape, on which an aluminum layer has been deposited, as in Example 3, is even more effective at the wrinkle zones minimize. Furthermore, a beneficial effect can be obtained even if the present invention is applied to a magnetic recording tape having a

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relatively small thickness, not exceeding 10 μπι when used as a recording tape for recording information for 120 minutes, as is the case in Example 4.

When the tape weld tape is displaced relative to the clamping piece 2 along the circumference of the wheel hub 1, as in the case of equation 1, where the tape medium is wrapped around the wheel hub, or when the tape welding tape is less than the width of the clamping piece 2, as in the case of equation 2, in which the tape welding tape is aligned radially with the clamping piece 2, it was discovered on the other hand that significant wrinkle zones were created, after the tape cassette was stored for a considerable period of time under the harmful conditions of high temperature and high humidity, resulting in a significant increase in SER associated with an increase in the value of the C2HF, resulting in listening to the information is unpleasant.

Figures 3a and 3b and Figures 4a and 4b show graphs of the error frequencies which occur at the parts of a tape in the tape cassette designated as B-top and A-end as an embodiment of the present invention and of a tape cassette according to the prior art, both being placed in a dry environment at 70 ° C for six hours. In each of these figures, the frame numbers occurring at C2HF and CF values ​​are shown at the top right of the figure. The measurements were performed by playing an end portion on the B side of the tire medium near the wheel hub for five minutes and then playing an end portion on the A side of the tire medium near the wheel hub for five minutes, i.e. a total of ten minutes. As shown in Figs. 4a and 4b, which are a prior art tape cartridge, significant ripple zones are created, with the SER having a value in the range between 40 and 50E-4, which is associated with the occurrence of the CF at rotation of the wheel hub and in the worst case, the C2HF occurs, resulting in information playback

00 5 77.5 which is unpleasant to listen to. In contrast, the ripple zones in the tape cassette as an embodiment of the present invention have been reduced, as can be seen from Figures 3a and 3b, the value of the SER being in the range between 1 and 2E-4, which is accompanied by a decrease in the frequency at which the CF occurs and at which no C2HF has occurred.

Although the present invention has been described in conjunction with preferred embodiments thereof, with reference to the accompanying drawings, it should be noted here that various changes and modifications will be obvious to those skilled in the art. Although in the above description, the use of aluminum to form a vapor-deposited metal-containing layer, for example, Au, Ag or Pt may also be used instead of aluminum.

Therefore, such changes and modifications are to be understood as part of the present invention as defined in the appended claims.

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