JP4383206B2 - Leader tape, leader tape tip cutting method, end mill, and magnetic tape cartridge - Google Patents

Description

  The present invention relates to a leader tape, a leader tape tip portion cutting method, an end mill, and a magnetic tape cartridge, and more specifically, firmly joins the leader tape to a magnetic tape wound around one reel in the magnetic tape cartridge. The present invention relates to a processing of a leading end of a leader tape and a method of cutting a portion of a leading end to obtain the processing.

  Conventionally, as a magnetic tape cartridge used as a recording medium of a computer or the like, a magnetic tape cartridge in which a magnetic tape is wound around one reel and the reel is rotatably accommodated inside a cartridge case composed of an upper cartridge and a lower cartridge. There is.

  In use, this magnetic tape cartridge is used by pulling out the magnetic tape from the opening of the cartridge case. When not in use, the magnetic tape is completely wound on the reel, and the leader tape joined to one end of the magnetic tape (the engaging means provided in the device such as a computer is connected to the magnetic tape). Engaging means for introducing the tape into the tape path) is locked to the end surface portion of the cartridge case, and the reel is locked by a locking means such as a reel lock so that the reel does not rotate unexpectedly. The opening is closed by a lid that can be freely opened and closed.

  FIG. 6 is a side view of a state in which the leader tape is joined to one end of the magnetic tape. As shown in FIG. 6, one end of the magnetic tape 60 is joined to a leader tape 62 made of polyethylene terephthalate (PET) by a splicing tape 64. The leader tape 62 has a thickness t in the original fabric state before being subjected to predetermined processing, but in order to ensure the joining with the magnetic tape 60 by the splicing tape 64, the leader tape 62 is attached to the portion 62a on the magnetic tape 60 side. Taper processing is performed so that the thickness t gradually decreases. Further, since the taper portion does not cause a significant step at the joint portion between the leader tape 62 and the magnetic tape 60, stable running is possible.

By the way, two methods have been proposed in the past in order to produce a leader tape 62 by applying a taper process to a PET original fabric having a thickness t.
One is a method of processing a tapered portion by performing chemical treatment by etching, and the second is a method of processing the tapered portion by mechanical cutting.
The former chemical treatment by etching has the advantage that there is no risk of cutting scraps protruding from the end of the leader tape because the finish of the surface is not rough, but it requires processing such as chemical application, washing, drying, etc. It takes time, and since there are a plurality of processes, it is a cause of lowering productivity. Furthermore, since chemical treatment is costly, it has been a cause of cost increase.
In the second mechanical cutting method, as described in Patent Document 1, the tip of the leader tape is tapered by rotating a cylindrical end mill with a certain angle with respect to the rotation axis of the roller. It cuts mechanically.
JP 2000-111591 A

FIG. 7 is a view showing a metal roll and an end mill for performing the mechanical cutting method described in Patent Document 1. In the figure, 740 is a raw fabric, 740a is a portion to be cut indicated by hatching, 742 is a metal roll, and 743 is a cylindrical end mill.
As shown in the figure, a to-be-cut portion 740 a indicated by hatching is mechanically cut into a tapered shape by a cylindrical end mill 743, and the rotation axis of the end mill 743 is not parallel to the rotation axis of the metal roll 742. It has a certain angle. By appropriately setting this angle and moving the end mill 743 in the original fabric direction, the cut portion 740a of the original fabric 740 can be tapered by a desired amount.
Thus, since the taper portion of the raw fabric (that is, the leader tape) 740 is processed by a mechanical method, the processing time can be shortened and the cost can be reduced as compared with the taper processing by chemical treatment. .
However, the leader tape obtained by using the usual cutting technique as described above has a surface roughness RZ of 8 μm or more (where RZ is RZ-JIS standard). The present applicant has noticed that there is a possibility that the cutting scraps and the like protrude and the other cutting parts are rubbed off and adversely affect other parts.

  Therefore, the present applicant can process the tip of the leader tape that can shorten the processing time and reduce the cost by omitting various processes such as chemical application, cleaning, and drying previously performed during chemical processing. A processing method has been developed to keep the surface roughness within a predetermined range.

FIG. 8 is a view showing a metal roll and an end mill for performing the mechanical cutting method according to the prior invention. FIG. 8A is a view showing the overall arrangement, and FIG. 8B is a view for explaining the end mill according to the prior invention. In the figure, 40 is a raw fabric, 40a is a part to be cut indicated by hatching, 42 is a metal roll, 43 is a cylindrical end mill according to the prior invention, and Q is a rake angle.
As shown in FIG. 8A, a to-be-cut portion 40 a indicated by hatching is mechanically cut into a tapered shape by a cylindrical end mill 43, and the rotation axis of the end mill 43 is the rotation axis of the metal roll 42. It is not parallel but has an angle. By appropriately setting this angle and moving the end mill 43 in the original fabric direction, the cut portion 40a of the original fabric 40 can be tapered by a desired amount.
As shown in FIG. 8B, the end mills according to the prior invention are the two-blade end mill 43 of (1) and the four-blade end mill 43 ′ of (2), and the conventional end mill shown in FIG. The cutting edge is different from the spiral one. By using such an end mill, a leader tape composed of irregularities of the cut portions at regular intervals can be obtained. The concave / convex spacing (pitch) of the cutting portion cut by the four-blade end mill 43 ′ is L / 2, and is naturally half the concave / convex spacing (pitch) L of the cutting portion cut by the two-blade end mill 43. The unevenness spacing of the cutting part is determined by the relative speed between the feed speed of the original fabric 40 and the rotation speed of the end mill 43.
Here, an end mill having a number of blades of 2 to 4 is used, the raw fabric (leader tape) 40 is transported in the vicinity of 1.0 m to 2.0 m / min, and the end mill is rotated in the vicinity of 10 to 20 krpm. I try to let them. In this case, the cross-section of both the two blades and the four blades was within the range of 2 μm ≦ RZ ≦ 5 μm, as indicated by hatching at the bottom of the figure.

FIG. 9 is a conceptual diagram showing three types of methods for tapering the end of the leader tape and the results of machining, (a) is a taper machining with the conventional continuous blade shown in FIG. 7, and (b) is a diagram. 8 shows a taper machining by a two-blade according to the prior invention, and FIG. 8C shows a taper machining by a conventional chemical treatment.
As shown in (a), when the raw fabric 40 is transported in the vicinity of 1.0 to 2.0 m / min, the end mill is transported at 10 to 20 krpm, and the end mill is rotated at about 15000 rpm, the conventional continuous The processing result obtained with the blade 743 had a surface roughness RZ of about 8 μm. When the surface roughness RZ is around 8 μm, the flaking when pressed by joining with a splice protrudes outward from the end of the leader tape, which is not preferable. Therefore, it is known that if the feed rate of the original fabric is made lower than that, the surface roughness RZ becomes lower, but this is not preferable from the viewpoint of productivity. This is because the feed rate of the original fabric is preferably about 1.5 m / min in consideration of productivity.

(B) is a figure which shows the processing result obtained by the 2-4 blades based on a prior invention, (1) is a 2 blade end mill, is rotated at about 15000 rpm, and the raw fabric 40 is about 1.5 m / It is the processing result obtained when it was made to transfer by a minute. (2) is a four-blade end mill, which is a processing result obtained when rotating at about 30000 rpm and transporting the original fabric 40 at about 1.5 m / min.
The surface roughness RZ was 5 μm in (1) and 2 μm in (2).
Further, when rotating at about 30000 rpm with a two-blade end mill and transferring the raw fabric 40 at about 1.5 m / min, the surface roughness RZ is 2 μm, and at a 1-5000 rpm end with a 4-blade end mill. When the substrate 40 was rotated and transferred at about 1.5 m / min, the surface roughness RZ was 5 μm.
And it turned out that it is most preferable that surface roughness RZ is 5 micrometers-2 micrometers (the reason is later mentioned using FIG. 10).

  (C) shows that the raw fabric 40 is immersed in an etching solution and taper processed. The obtained processing result has a surface roughness RZ of about 3 μm, but the surface of the roughness pattern by etching erosion is the surface by cutting. In contrast to the above, it has been found that there is another factor which is not determined only by a small surface roughness RZ due to poor adhesive strength (the reason will be described later with reference to FIG. 10).

FIG. 10 is a conceptual diagram illustrating that the surface roughness RZ applied to the end of the leader tape is optimally 5 μm to 2 μm. FIG. 10A is a surface roughness RZ of 3 μm by taper processing using chemical treatment. In the case of the vicinity, (b) shows a case where the surface roughness RZ by taper processing according to the prior invention is 5 μm to 2 μm, respectively.
In the case of the leader tape 40 having a surface roughness RZ in the vicinity of 3 μm in (a), since the chemical treatment is performed, the surface has no sharpness. Even if it is covered with a splice 64 and joined, the leader tape 40 and The physical engagement with the splice 64 (that is, the leading end of the leader tape 40 pierces into the splice 64) does not occur, and since the unevenness of the leader tape 40 is low, the contact area between each other is small and strong bonding strength is achieved. It was found that durability could not be obtained.

  On the other hand, in the case of the leader tape 40 having a surface roughness RZ of 5 μm to 2 μm in (b), the surface irregularities are high and the tip is pointed. The tip 40s of the tip is pierced into the splice 64 to obtain the strength by mechanical coupling with each other, and since the unevenness of the leader tape 40 is deep, the mutual contact area is increased to obtain a strong joining strength and durability. It has been found.

  Further, when the surface roughness RZ obtained with the conventional continuous blade 743 is about 8 μm, the surface roughness is larger than that of the leader tape 40 having the surface roughness RZ of (b) above, so that sufficient bonding strength is obtained. In spite of this, durability is obtained, but conversely, when it is joined and pressed with a splice, the lump protrudes from the end of the leader tape toward the outside, and this must be avoided, so the overall result is ( The surface roughness RZ of b) was inferior to the leader tape of 5 μm to 2 μm.

Further, even if the surface roughness RZ is reduced by chemical treatment, it has been found that the bonding strength and durability are insufficient, and another factor that is not determined only by the surface roughness RZ (that is, the surface has sharpness) It was found that the surface roughness RZ of 5 μm to 2 μm by cutting was optimal.
Therefore, according to the prior invention, the surface roughness RZ of the tip of the leader tape 40 is 5 μm to 2 μm. Specifically, this means that the end mill uses 2 to 4 blades instead of continuous blades, the leader tape is transferred at about 1.5 m / min, and the end mill is rotated at about 15000 rpm. It was obtained at.

By doing the above, it is possible to omit various processes such as chemical application, cleaning, and drying that have been performed during chemical processing, thereby shortening the processing time and reducing the cost. Thus, a processing method having a surface roughness in a predetermined range was obtained.
However, as a result of further investigation by the present applicant, if the roughness RZ of the machining surface is 2 μm ≦ RZ ≦ 5 μm and further unevenness is formed, the bonding strength is further improved and durability is obtained. It was found that
Therefore, the present invention is a processing method for the tip portion of the leader tape that can reduce various processing steps such as chemical application, cleaning, and drying performed during chemical processing, thereby reducing processing time and cost. It is an object of the present invention to provide a processing method in which the roughness of the surface falls within a predetermined range, and further, irregularities are formed within the range.

In order to solve the above-mentioned problems, the invention of the leader tape according to claim 1 is a leader tape to be joined to the front end of the magnetic tape by a splice, and the front end portion thereof is mechanically tapered. In the leader tape that has been cut, a plurality of grooves extending in the length direction of the leader tape are dug on the cutting surface by cutting , and the peaks and valleys that constitute each groove are Concavities and convexities are respectively formed by cutting in the length direction of the leader tape.
According to a second aspect of the present invention, in the leader tape according to the first aspect, the irregularities are formed so that the roughness RZ of the cutting surface is in the range of 2 μm ≦ RZ ≦ 5 μm.
According to the invention of claim 3, the tip portion of the leader tape is mechanically cut into a taper shape by an end mill, and a plurality of grooves extending in the length direction of the leader tape are formed on the cutting surface, and In the leader tape tip partial cutting method for forming irregularities in the length direction of the leader tape in the crests and troughs constituting each groove, the end mill has a continuous blade or 2 to 4 blades. Each of the blades is provided with an uneven projection in the axial direction.
The invention according to claim 4 is the leader tape tip partial cutting method according to claim 3, wherein the leader tape is transferred in the vicinity of 1.0 m to 2.0 m / min, and the end mill is rotated in the vicinity of 10 k to 20 krpm. It is characterized by making it.
According to a fifth aspect of the present invention, there is provided the magnetic tape cartridge according to the first or second aspect, wherein the leader tape, a single magnetic tape reel, one is joined to the leader tape, and the other is wound around the single magnetic tape reel. And a magnetic tape.

According to invention of Claim 1, since the unevenness | corrugation is each formed in the length direction of this leader tape in the peak part and trough part which comprise each groove | channel, joining strength improves and the leader with big durability Tape is obtained.
According to the second aspect of the present invention, the surface roughness is in the range of 2 μm ≦ RZ ≦ 5 μm, and the crests and troughs constituting each groove are each uneven in the length direction of the leader tape. Therefore, the joining strength is further improved, and a leader tape having greater durability can be obtained.
According to the third aspect of the invention, by executing this leader tape tip partial cutting method, the joining strength is improved and a leader tape having a great durability can be obtained.
According to the fourth aspect of the invention, by executing this leader tape tip portion cutting method, the joining strength is improved, and a leader tape having a large durability can be easily obtained.
According to the fifth aspect of the present invention, since the bonded magnetic tape to the leader tape with large durable bonding strength is improved, magnetic tape cartridge is obtained with a large kina durable.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.
FIG. 1 is an exploded perspective view of a magnetic tape cartridge according to an embodiment of the present invention.
In the magnetic tape cartridge 1 shown in FIG. 1, a magnetic tape 20 is wound around one reel 3 formed by, for example, ultrasonic bonding of an upper reel 4 and a lower reel 5, and this reel 3 is used as an upper cartridge 2a and a lower cartridge 2b. Are rotatably housed in a cartridge case fastened by screws 19.

  In the reel 3, the upper reel 4 has an upper flange 4a, and a concave portion is provided at the center thereof. And the gear part 4b is formed in the outer periphery of this upper flange 4a. A ring-shaped bearing 6 is press-fitted and fixed in a circular rib formed in the recess, and a spring plug 7 is press-fitted and fixed in a hole in the center of the bearing. A reel spring 8 is attached to the spring plug 7 to press the reel 3 downward and hold it rotatably.

  The reel 3 is locked so as not to rotate unexpectedly by a reel lock 32 appropriately biased by a reel lock spring 12 when the cartridge is not used. The tip of the magnetic tape 20 is joined to the leader tape 21 by a splice, and the leader tape 21 is locked to the tip of the leader tape 21 by ultrasonic welding. When the magnetic tape cartridge 1 is not in use, the magnetic tape 20 is completely wound around the reel 3, and the leader pin 21a is locked to the front end portion of the hook 18 incorporated near the side of the cartridge. Has been.

  A lid 30 that can be opened and closed in the cartridge plane direction is attached to the opening 26 through which the magnetic tape 20 is drawn out by being appropriately urged by a lid spring 15 for urging the lid. Further, the leader tape 21 engaged with the engaging means for introducing the magnetic tape 20 into the tape path of the apparatus has a tip within the roughness range defined by the present invention. 20 is strongly joined by the splicing tape.

Next, with reference to FIG. 2, the manufacturing method of this leader tape is demonstrated.
As shown in FIG. 2, a PET original fabric 40 having a thickness larger than that of a magnetic tape is wound around a supply roll 41, and the original fabric 40 supplied from the supply roll 41 is first a first metal roll 42. And the first end mill 43, the second metal roll 45 and the second end mill 46, and finally the take-up roll 48.
For the material to be cut, it is better not to cut the dimension in the longitudinal direction accurately, but to make a slightly larger cutting part in the longitudinal direction and adjust the dimensions by press cutting at the final press stage. .
Also, instead of the machining step as shown in FIG. 2, after the portion to be cut is tapered by the second end mill 46, a cleaning roll is provided to clean the surface of the original fabric, and press punching is performed immediately thereafter. Can be a continuous process.

3A and 3B are diagrams showing a metal roll and an end mill for performing the mechanical cutting method according to the present invention. FIG. 3A is a diagram showing the overall arrangement, and FIG. 3B is a diagram for explaining the end mill according to the present invention. In the figure, 140 is a raw fabric, 140a is a portion to be cut indicated by hatching, 142 is a metal roll, and 143 is a cylindrical end mill according to the present invention.
As shown in FIG. 3A, a to-be-cut portion 140 a indicated by hatching is mechanically cut into a tapered shape by a cylindrical end mill 143, and the rotation axis of the end mill 143 is the rotation axis of the metal roll 142. It is not parallel but has an angle. By appropriately setting this angle and moving the end mill 143 in the direction of the original fabric, the cut portion 140a of the original fabric 140 can be tapered by a desired amount.
As shown in FIG. 3B, the end mill according to the present invention is an end mill 143 having a two-blade 143a of (1) and an end mill 143 ′ having a four-blade 143a ′ of (2), The blades 143a and 143a ′ are characterized by being provided with uneven protrusions in the length direction.

FIG. 4 is a perspective view for explaining the cutting situation of the end mill, wherein (a) shows the result according to the present invention and (b) shows the result according to the prior invention for reference.
In FIG. 2B, reference numeral 43 denotes an end mill having a two-blade 43a, which is rotated at about 15000 rpm and when the raw fabric 40 is transferred at about 1.5 m / min, the surface roughness RZ is 2 μm ≦ RZ ≦ 5 μm. As described above, the plurality of grooves M1 to M3... Are dug in the length direction of the leader tape.
On the other hand, in the figure (a), 143 is an end mill provided with the 2 blades 143a, and each 2 blades 143a is provided with convex protrusions 143b and recesses 143c alternately in the length direction. Therefore, when such an end mill 143 is rotated at about 15000 rpm and the original fabric 140 is transferred at about 1.5 m / min, a plurality of grooves (M1 to M3...) Having a surface roughness RZ of 5 μm are formed. Convex portions c and concave portions d are alternately formed in the length direction of the leader tape in the crest portion b and the trough portion v which are dug in the length direction of the leader tape and constitute each groove (M1 to M3...). It can be seen that it is formed.
In this way, the roughness RZ of the cutting surface is in the range of 2 μm ≦ RZ ≦ 5 μm, and since the concave portion c and the convex portion d are further formed, the bonding strength is further improved and durability is obtained. It was decided that

  As a means for performing taper processing by cutting, a method has been shown so far in which a substantially cylindrical end mill has a predetermined angle with respect to the rotating shaft of a roller that supports the original fabric. A method may be adopted in which a taper process is applied to itself and the raw material is cut at the taper portion.

  As a result of such taper processing, the thickness of the tip of the leader tape gradually decreases, but generally the thickness of the leader tape is about 100 to 200 μm, which is considerably thicker than the thickness of the magnetic tape. However, the thickness is gradually reduced only to 2 to 10 times the thickness of the magnetic tape, but if it has converged to such a thickness difference, a desired effect can be obtained.

The above was applied to the end mill according to the prior invention of the present invention, and further effects were achieved. However, when applied to the conventional continuous blade, the surface roughness RZ, which was a drawback of the conventional continuous blade, was 8 μm. It was confirmed that the roughness was significantly reduced because the unevenness processing according to the present invention was added, which was too rough before and after, and entered an acceptable range of around 5 μm.
Therefore, although the effect is not reached by 2 to 4 blades, the end mill can be used practically.

  Note that the present invention is not limited to the above-described embodiment, and can be appropriately changed and improved based on the gist of the present invention. For example, the shape of the end mill that cuts the taper portion is not limited to the above-described shape, and it is also possible to provide a step portion at the tip of the end mill so that the tapered portion is inclined.

Further, as described above, the unevenness on the surface of the leader tape is effective for improving the joining strength between the leader tape and the splice tape, but as a result, the strength of the magnetic tape and the splice tape is also improved.
Further, at the end of the leader tape opposite to the splice tape joining side, the leader pin is joined by ultrasonic welding. In order to improve the strength of this welding joining, the convex portion is formed by cutting according to the present invention. And using this convex part as ED (Energy Director), melting the convex part continuously provided at the time of cutting and welding with the cutting surface of the leader tape being abutted to increase the bonding strength with the leader pin Is also possible.

FIG. 5 is a conceptual perspective view showing a state in which the leader tape cut in this manner is joined to the leader pin at the front end and to the magnetic tape at the rear end.
In the figure, 40 is a leader tape made of polyethylene terephthalate (PET), 40a is a tip portion (first cutting portion) on which unevenness is formed according to the present invention, and 40b is a leader pin 21a (also in FIG. 1). Winding part (non-cutting part) tightly wound around the figure (not shown), 40c is a central part (non-cutting part), 40d is a rear end part (second cutting) that has been subjected to cutting with irregularities formed by the present invention. Part).

As shown in the drawing, the leader pin 21a is tightly wound in the vicinity (40b) of the leader tape 40, and the tip (40a) is ultrasonically welded to the non-winding leader tape (40c). Furthermore, it is tapered so as to taper toward the tip. If the thickness of the leader tape tip 40a is t1, and the thickness of the unwrapped leader tape 40c is t2, then t1 <t2.
As described above, since the tip 40a is subjected to cutting processing with irregularities formed, the convex portion physically bites into the leader tape and melts in the leader tape. Bonding will be obtained.

On the other hand, the splicing tape 64 is joined to the rear end portion 40 d of the leader tape 40 on the surface roughness of 5 μm or less, thereby joining to the magnetic tape 60. The leader tape 62 has a thickness t2 in the original state before being subjected to the cutting process, but in order to ensure the joining of the splicing tape 64 to the magnetic tape 60, the magnetic tape 60 at the rear end portion 40d of the leader tape 40 is secured. The taper processing is performed so that the thickness of the taper gradually decreases to t3. That is, t3 <t2. With such a tapered portion, there is no step at the joint between the leader tape 62 and the magnetic tape 60, so that stable running is possible.
In addition, since the surface is subjected to cutting with irregularities formed, strong bonding with the splicing tape 64 can be obtained.

  As described above, according to the present invention, the leading end of the leader tape that engages with the engaging means of the apparatus is joined to the leading end of the magnetic tape so that the leading end of the leader tape has a surface roughness RZ. Is mechanically cut to 5 μm to 2 μm, and the concave and convex portions are formed in the length direction of the leader tape, so that the joint strength is further improved, durability is obtained, and the conventional chemical treatment is performed. Various processes such as chemical application, cleaning, and drying that have been performed can be omitted, and processing time can be shortened and costs can be reduced.

1 is an exploded perspective view of a magnetic tape cartridge according to the present invention. It is the schematic for demonstrating the manufacturing method of a leader tape. It is a figure explaining the cutting method by the end mill and metal roll which concern on this invention. It is a perspective view explaining end mill cutting concerning the present invention. 1 is a conceptual perspective view showing a state in which one end of a cut leader tape according to the present invention is joined to a leader pin and a rear end is joined to a magnetic tape. FIG. It is a side view in the state where a leader tape was joined to one end of a magnetic tape. It is a figure explaining the cutting method by the end mill and metal roll shown by patent document 1. FIG. It is a figure explaining the cutting method by the end mill and metal roll which concern on prior invention. FIG. 9 is a conceptual diagram showing three types of methods for tapering the end of a leader tape and the results of the machining, (a) is a taper machining with a conventional continuous blade shown in FIG. 7, and (b) is a preceding one shown in FIG. The taper processing by the 2 blades which concerns on invention, (c) has each shown the taper processing by the conventional chemical | medical agent process. It is a conceptual diagram explaining that the surface roughness RZ applied to the end portion of the leader tape is optimal at 5 μm to 2 μm. (A) is a case where the surface roughness RZ by taper processing using chemical treatment is 1 μm or less, b) shows a case where the surface roughness RZ by taper processing according to the present invention is 5 μm to 2 μm.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Magnetic tape cartridge 2 Cartridge 2a Upper cartridge 2b Cartridge 3 Reel 4 Upper reel 4a Upper flange 4b Gear part 5 Lower reel 6 Bearing 7 Spring plug 8 Reel spring 12 Reel lock spring 15 Lid spring 18 Hook 19 Screw 20 Magnetic tape 21 Leader tape 21a Leader pin 26 Opening 30 Lid 32 Reel lock 40 Raw material 40a made of PET Cutting part 40s Pointed part 41 Feeding roll 42 First metal roll 43 First end mill 45 Second metal roll 46 Second end mill 48 Winding roll 143 End mill 140a to-be-cut portion 142 Metal roll 140 Original fabric 143a Two-blade 143a ′ Four-blade 143 Two-blade end mill 143 ′ Four-blade end mill 143b Convex protrusion 143c Concavity b Mountain portion v Valley portion c Original fabric convex part d Original fabric concave part

Claims (5)

A leader tape that is spliced and joined to the tip of a magnetic tape, and the tip of the leader tape is mechanically machined into a tapered shape, and the leader tape is provided on the machined surface. A plurality of grooves extending in the length direction of the groove are dug by cutting , and unevenness is formed by cutting in the length direction of the leader tape in the crests and troughs constituting each groove. Leader tape characterized by that.   2. The leader tape according to claim 1, wherein the unevenness is formed in a range of roughness RZ of the cut surface of 2 μm ≦ RZ ≦ 5 μm (where RZ is RZ-JIS standard). The tip portion of the leader tape is mechanically cut into a taper shape by an end mill to form a plurality of grooves extending in the length direction of the leader tape on the cutting surface, and the ridges constituting each groove In the leader tape tip part cutting method for forming irregularities in the length direction of the leader tape in the trough and the end tape, the end mill is a continuous blade or having two to four blades, and each blade has an axial direction. A leader tape tip partial cutting method characterized in that an uneven projection is provided on the tip of the leader tape.   4. The leader tape tip partial cutting method according to claim 3, wherein the leader tape is transferred in the vicinity of 1.0 to 2.0 m / min, and the end mill is rotated in the vicinity of 10 to 20 krpm.   3. A leader tape according to claim 1; a single magnetic tape reel; and a magnetic tape, one of which is joined to the leader tape and the other is wound around the single magnetic tape reel. Magnetic tape cartridge.

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