JP2001110045A - Magnetic tape machining device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic tape machining device which can highly efficiently produce a magnetic tape that has excellent characteristic to cause no slippage despite of a high tape feeding speed and also to reduce a cupping. SOLUTION: This magnetic tape machining device is provided with a hollow cylindrical drum which can freely revolve, a revolving means which revolves the drum around its axis, an optical system which emits a planar laser beam on the inner side face of the drum to form a line, a feeding device which places a magnetic tape at a machining position set on the optical path of the laser beam that is made incident on the inner face side of the drum and transmitted through a through-hole and at the same time feeds the tape in its lengthwise direction matched with the drum revolving direction with a back layer turned toward the drum and a differential pressure generating means which generates the differential pressure between the inside and outside the drum.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of magnetic tapes used for recording / reproducing information, and more specifically, does not cause slip even when a magnetic tape is conveyed at a high speed in a magnetic tape manufacturing process or the like. The present invention relates to a magnetic tape processing apparatus for producing a magnetic tape with small cupping.

[0002]

2. Description of the Related Art A magnetic tape used for recording and reproducing information basically includes a base layer which is a film such as PET (polyethylene terephthalate) and a magnetic layer formed on one surface of the base layer. For the purpose of improving transport stability and strength, the magnetic recording medium has a back layer formed on the opposite surface of the magnetic layer of the base layer.

In the process of manufacturing such a magnetic tape, the magnetic tape (hereinafter referred to as a tape) is subjected to various processes such as cutting by a slitter and cleaning of a surface by a blade while being transported in a longitudinal direction. And then rolled up in a hub or the like to make pancakes or cassettes and sent to the next process or delivery destination. In recent years, in order to improve productivity, various processes (such as manufacturing equipment such as blade machines and winder machines) ) Tends to increase the tape transport speed.

[0004] In general, the tape is conveyed by winding the tape around a capstan roller and rotating the capstan roller. However, when the transport speed of the tape is increased, in a manufacturing apparatus such as a blade machine, the tape entrains air, and the tape floats on a capstan roller or the like, thereby causing the tape to slip, thereby preventing normal transport. There are cases.

As a result, the tape becomes a capstan roller,
The tape is damaged or improperly collides with the guide roller, blade blade, etc., and the tape or tape edge is broken, or the tape is damaged such as abrasion or peeling of the magnetic material layer. Will be. Further, the tape manufacturing apparatus is provided with a roller (measurement roller) for measuring the length of the tape as necessary. However, if the tape slips, an error occurs in the measurement of the tape length, and the production control is performed. Also cannot be performed properly. for that reason,
It has been difficult to increase the tape transport speed in tape manufacturing so as to properly meet the required production efficiency.

[0006] Another problem of the tape is as follows.
Curling (curving) in the width direction of the tape, so-called cupping, is known. Cupping is mainly caused by the difference in the shrinkage of the binder used between the magnetic layer and the back layer. When cupping occurs, the appearance of the magnetic tape as a product deteriorates; And the like, which may cause a recording error or a reading error; damage to the edge of the magnetic tape is likely to occur;

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art. In a magnetic tape manufacturing apparatus such as a blade machine and a winder machine, the tape transport speed is increased. Another object of the present invention is to provide a magnetic tape processing apparatus capable of producing a magnetic tape having excellent characteristics without causing a slip of the tape in a capstan roller or the like, and having a small cupping with good production efficiency.

[0008]

In order to achieve the above object, the present invention provides a rotatable hollow cylindrical drum having a large number of through holes on its side, and a rotating means for rotating the drum about an axis. An optical system for projecting a planar laser beam onto the inner surface of the drum and defining a line by the laser beam; and setting the optical system on the optical path of the laser beam incident on the inner surface and passing through the penetrating light. A transport device that transports the magnetic tape in the longitudinal direction in accordance with the rotation direction of the drum, with the back layer facing the drum while the magnetic tape is positioned at the processing position to be processed, and the inside and outside of the drum. And a differential pressure generating means for generating a pressure difference between the magnetic tape processing apparatus and the magnetic tape processing apparatus.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic tape processing apparatus according to the present invention will be described below in detail with reference to the preferred embodiments shown in the accompanying drawings.

The magnetic tape processed by the magnetic tape processing device of the present invention (hereinafter referred to as a processing device) is made of PET.
Layer (base film) made of amide or aramid resin
Layer structure having a magnetic layer on one side and a back layer (back coat layer) on the other side of the base layer, or further having an overcoat layer (protective layer) and an undercoat layer And processed by the processing apparatus of the present invention to form a recess (preferably a groove) in the back layer.

FIG. 1 conceptually shows an example of a back layer of a magnetic tape (hereinafter, referred to as a tape) having a concave portion in the back layer processed by the processing apparatus of the present invention. In the example shown in FIG. 1, a dotted dotted processing pattern extending in the longitudinal direction, which is formed of short grooves (processing line segments a) extending in the longitudinal direction of the tape, is formed in the back layer of the tape in the width direction of the tape. (Hereinafter referred to as the width direction).

Incidentally, the shape (cross-sectional shape) of such a concave portion
Is not particularly limited, and examples thereof include a rectangle, a triangle, and a semicircle (bow). Such a shape may be adjusted by the beam spot intensity distribution of the laser beam for processing the back layer. The depth of the recess is not particularly limited, and may be appropriately determined according to the strength of the tape or the like. However, in order to obtain a good effect, the depth of the recess is preferably 0.1 μm or more. In particular, the thickness is preferably 0.2 μm or more. Further, the size (line width) and the formation density of the concave portion are not particularly limited, and may be appropriately determined according to the strength and width (size) of the tape. For example, as shown in FIG. 1, when forming a processing line segment a in a dotted line extending in the longitudinal direction on a tape having a width of 0.5 inch, the width is 3 μm to 10 μm.
It is preferable to form several to about 100 processing lines in the width direction.

The tape having such a concave portion in the back layer has a small amount of air entrainment by the tape even when the tape is conveyed (running) at a high speed, and even when air is entrained, the tape can be suitably removed from the concave portion. Therefore, even when the tape is conveyed at high speed by a tape manufacturing apparatus such as a blade machine, the tape does not rise and slip due to the capstan roller or the like, and there is no damage or error in the conveyance length caused by the tape. Therefore, by using the tape T, it is possible to perform high-speed and accurate tape conveyance, and to manufacture a magnetic tape of appropriate quality stably and efficiently under appropriate production management. Also, since the air between the tapes is preferably released during winding, the winding appearance when wound into a cartridge or pancake is also beautiful.

Further, this tape having a concave portion in the back layer has less cupping than the conventional tape, and has a lower appearance, worsening per head, and damage to the tape edge due to the cupping than the conventional tape. And greatly reduced. The reason why cupping can be reduced by forming a concave portion in the back layer is not clear,
Since the stress generated in the width direction of the tape due to the above-described difference in the shrinkage ratio of the binder is cut at the concave portion, the force generated in the width direction of the tape is reduced as a whole, and as a result, it is considered that cupping can be prevented. .

FIG. 2 shows such a concave portion (magnetic).
1 shows a conceptual diagram of a processing apparatus of the present invention for producing a tape.
In FIG. 2, (A) shows a view of the processing apparatus viewed from the width direction of the tape, and (B) shows a view of the processing apparatus viewed from the longitudinal direction (transport direction) of the tape. Things.

The illustrated processing apparatus 10 basically includes a light source 12 and a sheet-like laser forming device 14 (both are shown in FIG.
(Omitted in (A)), a processing drum 16, a tape transport device 18, and a suction chamber 20. As will be described in detail later, a mirror 22 is disposed in the processing drum 16. In the processing device 10 of the illustrated example,
Light source 12, sheet-like laser forming device 14, and mirror 22
Thus, the optical system of the present invention is configured.

The light source 12 emits a laser beam serving as a laser beam for processing the back layer of the tape T.
The light source 12 is not particularly limited, and various laser beam light sources (laser oscillators) can be used as long as they can emit a laser beam having an output capable of processing the back layer. Preferably, one that emits at least one of an ultraviolet laser beam and a visible laser beam is used. In terms of workability, a laser beam having a short wavelength is more preferable, and a laser beam in the ultraviolet region is most preferable, whereas a laser beam in the visible region is preferable in terms of cost, safety, workability, and the like. Specifically, 488 nm
And a light source that emits a 532 nm laser beam obtained by converting the wavelength of a 515 nm argon (ion) laser, a YAG laser with an SHG (Second Harmonic Generation second harmonic generation) element, or the like.

The laser beam emitted from the light source 12 is
It is incident on a sheet-like laser molding device 14 (hereinafter, molding device 14). The shaper 14 expands (diffuses) the laser beam in only one direction, and then shapes the laser beam into parallel light.
It is a flat laser beam (hereinafter, referred to as sheet light S). The forming device 14 is preferably provided with a processing drum 16.
Is a sheet light S that defines a line in the radial direction of the sheet light. Further, in the illustrated example, as a more preferable mode, the sheet light S
And the tape T are positioned so as to be orthogonal to each other in a plane. There is no particular limitation on such a molding machine 14, and various known optical systems (optical elements) that can use the laser beam as the sheet light S can be used. Specifically, an optical system combining a cylindrical lens and a collimator lens, an optical system combining a rod lens and a cylindrical lens (collimator lens), and the like are exemplified.

The sheet light S then enters the inside of the processing drum 16 from the end face thereof, is reflected by the mirror 22 disposed in the processing drum 16, enters the inside surface of the processing drum 16, and is processed on the inside surface. A line parallel to the axis of the drum 16 is defined. The mirror 22 is fixed to the rotation of the processing drum 16 to be described later by a known method such as fixing to the center shaft 26 of the processing drum 16 or fixing to an external stay. The mirror 22 is preferably arranged at an angle of 45 ° with respect to the incidence of the sheet light S,
That is, it is preferable that the sheet light S be reflected 90 ° by the mirror 22 and perpendicularly enter the inner surface of the processing drum 16.

FIG. 3 is a schematic cross-sectional view of the processing drum 16 (a-a line in FIG. 1A). The processing drum 16 basically includes a hollow cylindrical drum main body 24 and a drum main body 24.
And a block 28 disposed inside the drum main body 24 so as to be rotatable about an axis. As described above, the mirror 22 is fixed inside the drum main body 24 of the processing drum 16.

The drum body 24 is formed by closing both end faces of a cylinder 30 with disks 32 (32a and 32b).
On the side surface of the cylinder 30, the circumferential direction (the direction of transport of the tape T)
Are formed so that a plurality of dotted lines extending in the axial direction are formed in the axial direction. Therefore, as shown in FIG.
The sheet light S incident on the inner surface of the (cylinder 30) defines a line parallel to the axis on the inner surface,
The portion that has entered 0a is emitted outside the drum body 24 as a laser beam. The processing pattern of the tape T may be adjusted according to the formation pattern of the through holes 30a.

The disk 32 closing the end face of the cylinder has an opening at the center. In the processing drum 16 of the illustrated example,
In this opening, the bearing 34 (34a and 34b)
, The disc body 32 is rotatably supported on the center shaft 26, thereby rotatably supporting the drum main body 24 about the axis. It should be noted that the disk 32 serving as an incident end face of the sheet light S
a is formed of a material such as quartz glass, through which the sheet light S can be transmitted, and which is preferably excellent in optical characteristics.

Alternatively, by adopting the structure shown in FIG. 4, the disk serving as the incident end face may be formed in a ring shape.
The example shown in FIG. 4 is an example in which a ring-shaped disk 50 having an opening for an incident area of the sheet light S is used instead of the light-transmitting disk 32a. In this example, the bearing 34
a disk 32 rotatably supported on the central shaft 26 by the c
c is disposed at a position sandwiching the disk 32b together with the disk 50, and the drum 54 is formed by closing both end surfaces of the cylinder 52 with the disk 32b and the disk 32c. That is, in this configuration, the drum 54 is rotatably supported about the axis by the center shaft 24, and the drum body 24 is held by the drum 54 so that the drum body 24 is rotatable about the axis. It is to support.

A central shaft 26 serving as a rotation shaft of the drum main body 24
Is a rigid pipe whose tip is closed, and has a plurality (three in the illustrated example) of holes 26a penetrating the side surface in a region inside the drum main body 24. The other end of the central shaft 26 is connected to an air introducing means (differential pressure generating means) such as a compressor or a blower. That is, air is introduced into the drum main body 24 via the central shaft 26, and is pressurized to the outside. As described above, since a large number of through holes 30a are formed in the cylinder 30 of the drum main body 24, the air inside the drum main body 24 in a pressurized state is blown out from the through holes 30a.

The pressure difference between the inside and the outside of the drum main body 24 (the pressure difference between the space formed by the concave portion 28a of the block 28 and the outside when the block 28 is described later).
The pressure difference is not particularly limited, and a pressure difference that can remove a processing residue or the like adhering to the through hole 30a of the processing drum 16 may be appropriately determined.

In the illustrated processing apparatus 10, a block 28 is fixed to the central shaft 26 as a preferred embodiment. The block 28 is a substantially semi-cylindrical member having a curved surface on the side opposite to the direction of reflection of the sheet light S by the mirror 22 (that is, on the side opposite to the tape T).
To form a space together with the inner surface of the drum main body 24. The block 28 is not in contact with the drum main body 24 and is configured not to hinder the rotation of the drum main body 24.
4 and the inner surface of the recess 2 inside the drum body 24.
The space formed by 8a is configured to be substantially airtight.

The space defined by the concave portion 28a and the hole 26a of the central shaft 26 communicate with each other through a communication hole 28b. Therefore, in the illustrated example, the space formed by the concave portion 28a is particularly pressurized by the air supplied from the central shaft 26, and the air in the drum main body 24 is mainly in this space, that is, the space opposite to the tape T. Through hole 3 located on the side
0a is ejected outside.

Further, in the illustrated example, as a preferred embodiment, the block 28 (particularly,
8a), a suction chamber 20 having an opening is disposed to face the space (space formed by 8a). The inside of the suction chamber 20 (the space defined by the chamber) is depressurized by a blower or a suction pump, and suctions outside air from an opening.
It is a known suction chamber. Therefore, the upper concave portion 28a
Is ejected from the through-hole 30a located in the space defined by the suction chamber 20 and is not scattered.

In the present invention, the block 28 and the suction chamber 20 are arranged in a preferred embodiment, and one or both of them may not be provided. However, in consideration of the influence of the air ejected (or sucked) from the through-hole 30a on the conveyance of the tape T, at least one of them, particularly the block 2
8 is preferably present.

The drum body 2 of such a processing drum 16
The center shaft 26 is rotated by a rotating means (not shown for simplicity of the drawing) such as a roller abutting on the outer periphery of the disk 32b and a belt wound around the outer periphery of the disk 32b.
Rotate about the axis of rotation. Here, the drum body 24 is
It is supported by the center shaft 26 via a bearing 34. Also,
The block 28 is fixed to the center shaft 26, and the mirror 22 is fixed to the rotation of the processing drum 16 by a known means. Therefore, only the drum main body 24 rotates in the processing drum 16. When the tape T abuts or is wound around the processing drum 16 (the cylinder 30 of the drum main body 24), the running of the tape T may be used as the rotating means.

On the other hand, in the processing apparatus 10, the tape T
Is transported in the longitudinal direction by the tape transport device 18 with the back layer facing the processing drum 16 (side surface of the drum main body 24) while being positioned at the processing position W (the transport direction x and the longitudinal direction are changed). And are conveyed in a predetermined direction). Further, the transport direction of the tape T and the drum body 2
4 have the same rotation direction.

The tape transporting device 18 includes, in addition to a support member 40 for positioning the tape T at a predetermined processing position W, transport driving means (not shown) such as a capstan roller, a rewinder and a winder, and a flanged roller and a crown roller. This is a known tape T transport device (traveling device) configured to include a position regulating unit in the width direction of the tape T, a guide roller, and the like. Alternatively, the disks 32a and 32
b may also serve as a position regulating means in the width direction of the tape T.

The supporting member 40 includes two blades 42 disposed so as to sandwich the processing position W in the direction of transport of the tape T;
And a fixing member 44 for fixing and supporting the blade 42. The blade 42 has, for example, a triangular prism shape in which the side ridges are arranged in the width direction, and supports the tape T at the processing position W by supporting the tape T from below by the side ridges.

The processing position W is reflected by the mirror 22 to define a line parallel to the axis on the inner surface of the drum main body 24 (the cylinder 30).
0a is set on the optical path of the sheet light S that has passed. Further, the rotation direction of the drum main body 24 and the transport direction (longitudinal direction) of the tape T coincide with each other. In other words, if the sheet light S is not shielded by the cylinder 30 of the processing drum 16, the sheet light S extends in the width direction to the back layer of the tape T transported in the longitudinal direction while being positioned at the processing position W by the tape transport device 18. Define the existing line.

As described above, in the processing apparatus 10 in the illustrated example, the sheet light S emitted from the light source 12 and formed by the forming device 14 is incident on the drum main body 24 from the light-transmitting disk 32a. Are reflected by the mirror 22 and define a line parallel to the axis on the inner surface of the drum body 24 (the cylinder 30). Here, since the drum main body 24 is rotated about the axis by the central shaft 26, the laser light incident on the through-hole 30a of the cylinder 30 out of the sheet light S defining the line on the inner surface is the cylindrical light. After passing through 30, the light enters the tape T at the processing position W to process the back layer. That is, the rotation of the drum main body 24 turns on / off the incidence of the laser beam on the back layer (processing of the back layer). Also, since the tape T is transported in the longitudinal direction by the tape transport device 18, the back layer of the tape T has a dotted line composed of processing line segments a arranged in the width direction as shown in FIG. Is continuously performed in the longitudinal direction.

Here, in the processing apparatus of the present invention for processing the back layer by laser light, both the thermal processing of the laser beam and the processing by ablation (dissociation and separation) caused by the laser beam occur in a complex manner. It is considered that the back layer is processed. Therefore, processing scum (dust and the like) and harmful gas may be generated by processing the back layer. Most of the processing residue adheres to the outer surface of the drum main body 24 (the cylinder 30) closest to the tape T, and closes the through hole 30a through which the sheet light S for processing the back layer of the tape T passes. There are cases.

On the other hand, the processing apparatus of the present invention introduces air from the central shaft 26 and
Is pressurized to provide a pressure difference from the outside, and air is ejected from the through-hole 30a. In particular, in the processing apparatus 10 of the illustrated example, as a preferred embodiment, the block 28 is provided to increase the pressure only in the region opposite to the tape T,
The area facing the block 28 is sucked by the suction chamber 20. Therefore, even if a processing residue adheres to the through-hole 30a, it is blown off by the air jetted from the inside, so that the through-hole 30a is not closed. In addition, according to the illustrated example, the ejection of the air is mainly performed in the area where the tape T does not exist under the action of the block 28, so that the transport of the tape T is not adversely affected. In addition, since the air and the processing dust ejected from the drum main body 24 are sucked in the suction chamber 20, the processing waste and the like do not scatter around.

As described above, in the processing apparatus of the present invention, the tape T and the drum main body 24 may be in non-contact or in contact with each other. Here, when the tape T and the drum main body 24 are not in contact with each other as in the illustrated example, the transport speed of the tape T and the rotation speed (peripheral speed) of the drum main body 24 need not necessarily match. Absent. Alternatively, in the case of non-contact, the back layer processing pattern of the tape T may be changed or adjusted by adjusting the rotation speed of the drum body 24 or the transport speed of the tape T (during processing). When the tape T and the drum main body 24 are in contact with each other, it is preferable that the two speeds be the same in order to avoid damage to the tape T. In this case, the drum body 24
May also serve as holding means for holding the tape T at the processing position.

In the above example, air is introduced into the drum main body 24 of the processing drum 16, and the inside is pressurized to eject air to the outside. However, the present invention is not limited to this. For example, the center shaft 26 is connected to an exhaust unit (differential pressure generating unit) such as a suction pump or a suction blower, and the inside of the drum body 24 is depressurized with respect to the outside, and air is sucked from the outside. By providing air blowing means instead of the suction chamber 20 and blowing air to the outside of the drum main body 24, processing waste generated by processing and attached to the through hole 30 a may be sucked into the drum main body 24.

At this time, the pressure difference between the inside and outside of the processing drum may be determined as appropriate, as in the above-described example, so that the pressure difference at which the processing residue attached to the through hole 30a of the processing drum 16 can be removed.

Further, in the processing apparatus of the present invention, a cleaning means such as an adhesive tape for removing a processing residue attached to the outer surface of the drum main body 24 may be provided.
Furthermore, in order to prevent contamination of the working environment due to processing waste and harmful gas, and damage and dirt on the front and back surfaces of the tape, the processing position W
Downstream (in the transport direction of the tape T), cleaning means (such as an adhesive tape) for cleaning the surface of the tape T,
A duct or the like for sucking gas may be provided.

The above-described processing of the tape T according to the present invention may be performed at any time during the manufacturing process of the magnetic tape as long as the back layer is formed. For example, before the tape is cut into a product width by a slitter. Or after cutting.

Although the magnetic tape processing apparatus of the present invention has been described in detail above, the present invention is not limited to the above-described example, and various modifications and changes can be made without departing from the gist of the present invention. Good. For example, in the illustrated example,
Although a pressure difference is generated between the inside and outside of the processing drum 16 by introducing or sucking air from the central shaft 26, the present invention is not limited to this. ), The processing drum 16
A pressure difference may be caused between the inside and the outside of the device.

[0044]

As described above in detail, according to the magnetic tape processing apparatus of the present invention, even when the transport speed is increased, the magnetic tape processing apparatus does not slip by the capstan roller or the like, and therefore, can transport at high speed and accurately. , And a magnetic tape having excellent characteristics with little cupping can be efficiently obtained. Moreover, according to the processing apparatus of the present invention, it is possible to prevent the processing waste generated by processing the back layer from adhering to the through-hole through which the laser beam for processing the back layer passes. Thus, the back layer of the magnetic tape can be properly processed. By using the magnetic tape manufactured by such a processing apparatus of the present invention, high-speed and accurate tape conveyance can be performed in a magnetic tape manufacturing apparatus such as a blade machine, and as a result, under appropriate production management. , It can produce magnetic tape without damage stably and with high production efficiency, and can also make the winding appearance beautiful when wound on a cartridge or pancake,
In addition, it is possible to prevent the tape from deteriorating in appearance, deteriorating the head contact, and damaging the tape edge due to cupping.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an example of a back layer of a magnetic tape processed by a magnetic tape processing device of the present invention.

2A is a conceptual diagram of an example of a magnetic tape processing apparatus according to the present invention as viewed from the width direction of the tape, and FIG. 2B is a conceptual diagram as viewed from the longitudinal direction of the tape T. .

FIG. 3 is a schematic sectional view taken along line aa of FIG. 2 (A).

FIG. 4 is a conceptual diagram of an optical system of another example of the magnetic tape processing device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 (Magnetic tape) processing apparatus 12 Light source 14 (sheet-like laser) molding machine 16 Processing drum 18 Tape transport apparatus 20 Suction chamber 22 Mirror 24 Drum main body 26 Central axis 26a, 26b Hole 28 Block 28a Depression 28b Communication hole 30 Cylindrical 30a Through hole 32 (32a, 32b, 32c), 50 disk 34 (34a, 34b, 34c) Bearing 40 Holding member 42 (42a, 42b) Blade 44 Fixing plate 54 Drum

Claims (1)

[Claims] 1. A rotatable hollow cylindrical drum having a large number of through holes on a side surface, a rotating means for rotating the drum about an axis, and a plane laser beam incident on the inner surface of the drum. An optical system that defines a line by the laser light, and a magnetic tape at a processing position set on an optical path of the laser light incident on the inner surface and passing through the penetrating light, In a state where the back layer is directed, a transport device that transports the magnetic tape in the longitudinal direction in accordance with the rotation direction of the drum, and a differential pressure generating unit that generates a pressure difference between the inside and the outside of the drum. Characteristic magnetic tape processing device.