WO1998044505A1 - Recording tape driving belt, process for producing the driving belt and driving type recording tape cartridge equipped with the driving belt - Google Patents

Abstract

A recording tape driving belt for preventing inclusion of air between the contact surfaces of the driving belt and a recording tape so as to prevent a tracking error and reducing errors of data recorded on the recording tape. A belt driving type recording tape cartridge equipped with such a driving belt is also disclosed. The recording tape driving belt has a plurality of longitudinal grooves in the contact surface thereof, and does not substantially have any edge in section in the contact portion.

Description

 Description Recording tape drive belt, method of manufacturing the drive belt, and belt-driven recording tape cartridge provided with the drive belt

 The present invention relates to a recording tape driving belt, a method for manufacturing the driving belt, and a belt-driven recording tape cartridge including the driving belt. Hereinafter, the “recording tape drive belt” may be abbreviated as a drive belt, and the “belt drive type recording tape cartridge” may be abbreviated as a tape cartridge. Background art

 Tape cartridges are disclosed, for example, in the specifications of U.S. Pat.Nos. 3,692,255, 4,581,189, and 4,466,564, and are widely used for data backup of computers and the like because of their simple and large storage capacity. It is getting.

The above-mentioned tape cartridge is basically composed of a pair of tape reels, a recording tape having both ends wound around the pair of tape reels, and guide means for guiding the recording tape to a predetermined traveling path. In addition, the inner surface is movably supported by a plurality of supporting means, and the outer surface is constituted by a drive belt which is always in contact with the recording tape at at least two places. The drive belt and the recording tape are in pressure contact with each other, and the recording tape runs by frictional force generated by the running of the drive belt. As a method of preventing a tracking error by preventing air from being drawn into the contact surface between the drive belt and the recording tape, multiple grooves are provided in the length direction of the surface of the drive belt on the contact surface side with the recording tape. Methods are known. And like this The method of manufacturing a drive belt having grooves is as follows: (a) a method of slicing an elastic resin cylinder having grooves formed in a circumferential direction on an outer peripheral surface according to a belt width; and (b) a circle of a flat surface portion. There is known a method in which an annular elastic resin sheet having a plurality of concentric grooves formed in the circumferential direction is twisted and stretched so that the grooves are located on the outer peripheral surface side. The manufacturing method (b) includes, for example, a step of punching an annular elastic resin sheet from the elastic resin sheet, and a step of forming a plurality of concentric grooves in a circumferential direction of one flat portion of the annular elastic resin sheet. Thus, an annular elastic resin sheet can be easily obtained, and a lower mold having an annular concave portion and a lower mold having an annular convex portion and a plurality of circumferentially extending annular planar portions of the convex portion are provided. A groove can be easily formed in the above annular elastic resin sheet by a groove forming step using a groove transfer mold composed of a lower mold having concentric grooves for forming grooves. It is relatively simple and has advantages such as excellent thickness accuracy.

 However, there is a problem that a conventional drive belt having a groove tends to cause a data error when used by being mounted on a tape cartridge. This problem is particularly remarkable in the drive belt obtained by the above-mentioned method (b) using a groove transfer mold for forming a groove.

 The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent a tracking error by preventing air from being drawn into a contact surface between a drive belt and a recording tape, and to reduce a data error in a recording tape. An object of the present invention is to provide a recording tape drive belt improved so as to reduce the occurrence thereof, a method of manufacturing the drive belt, and a belt-driven recording tape cartridge provided with the drive belt. Disclosure of the invention

The present inventors have conducted various studies to achieve the above object, and as a result, It has been found that the occurrence of data errors in the above is caused by the structure of the driving belt, in which the pressing force against the recording tape tends to concentrate. The present invention has been completed based on such findings, and the gist of each invention is as follows.

 A first gist is a driving belt in a belt-driven recording tape cartridge that causes a recording tape to run by the driving belt, and has a plurality of grooves in a length direction of a surface on a contact surface side with the recording tape, In addition, the drive belt is characterized in that there is substantially no edge at a portion of the cross section that comes into contact with the recording tape.

 The second gist is a drive belt in a belt-driven recording tape cartridge that moves a recording tape by an S-section driving belt, wherein a plurality of grooves are formed in a length direction of a surface on a contact surface side with the recording tape. At the upper and lower ends in the width direction on the contact surface side with the recording tape, a retraction depth equivalent to 1 to 200 to 1920 of the belt thickness and a width equivalent to 2 to 20% of the belt width are provided. A recording tape drive belt characterized in that a step is formed.

 The third gist is a method of manufacturing a drive belt in a belt-driven recording tape cartridge in which a recording tape is caused to travel by a drive belt, comprising the steps of: punching an annular elastic resin sheet from an elastic resin sheet; A step of forming a plurality of concentric grooves in the circumferential direction of one flat portion of the groove, and a step of twisting and stretching the grooved annular elastic resin sheet so that the grooves are located on the outer peripheral surface side, In the groove forming step, a lower mold having an annular concave portion, and a concentric circular groove forming portion having an annular convex portion and at least the outermost periphery and the innermost periphery of the annular flat portion of the convex portion are provided. There is provided a method for manufacturing a recording tape drive belt, characterized by using a groove transfer mold including an upper mold having a convex portion.

A fourth gist is that a pair of tape reels, a recording tape having both ends wound around the pair of tape reels, and a guide for guiding the recording tape to a predetermined traveling path. A belt-driven recording tape cartridge, comprising: a recording means; and a recording tape driving belt whose inner surface is movably supported by a plurality of supporting means and whose outer surface constantly contacts the recording tape at at least two places. The drive belt is provided with a plurality of grooves in the length direction of the surface on the contact surface side with the recording tape, and the upper and lower ends in the width direction on the contact surface side with the recording tape have a belt thickness of 1Z200 to A belt-driven recording tape cartridge characterized in that a recess having a receding depth corresponding to 19Z20 and a width corresponding to 2 to 20% of the belt width is formed.

 The fifth gist is a drive belt in a belt-driven recording tape cartridge in which a recording tape is caused to travel by a drive belt, and has a plurality of rounded corners in the longitudinal direction of the surface on the contact surface side with the recording tape. A recording tape drive belt, characterized in that the recording tape drive belt is provided with a groove.

 The sixth gist is a method of manufacturing a drive belt in a belt-driven recording tape cartridge in which a recording tape is caused to travel by a drive belt, comprising the steps of: punching out an annular elastic resin sheet from an elastic resin sheet; It consists of a step of forming a plurality of concentric grooves in the circumferential direction of one flat portion of the resin sheet, and a step of twisting and stretching the grooved annular elastic resin sheet so that the grooves are located on the outer peripheral surface side. In the groove forming step, a lower mold having an annular concave portion, and a plurality of concentric grooves for forming a plurality of concentric grooves in the circumferential direction of an annular flat portion having an annular convex portion are provided. A recording method characterized in that a groove transfer mold including a lower mold having an uneven portion is used, and a hot press process is performed by making the protrusion of the upper mold into the recess of the lower mold shallow. Tape drive belt manufacturing method Exist.

A seventh aspect is a method of manufacturing a drive belt for a belt-driven recording tape cartridge in which a recording tape is caused to travel by a drive belt, wherein at least one surface of an elastic resin sheet has a plurality of rounded corners. Forming a concentric groove; A step of punching an annular elastic resin sheet from the elastic resin sheet having the concentric grooves formed thereon so that a plurality of concentric grooves are formed in the circumferential direction of the plane portion; Twisting and stretching the elastic resin sheet so that the groove is positioned on the outer peripheral surface side.

 The eighth point is that a pair of tape reels, a recording tape having both ends wound around the pair of tape reels, a guide means for guiding the recording tape to a predetermined traveling path, and a plurality of supporting means. In a belt-driven recording tape cartridge provided with a recording tape driving belt whose inner surface is movably supported and whose outer surface constantly contacts the recording tape at at least two places, the driving belt is in contact with the recording tape. A belt-driven recording tape cartridge characterized in that a plurality of grooves having rounded corners are provided in the longitudinal direction of the front surface. BRIEF DESCRIPTION OF THE FIGURES

 FIG. 1 is an explanatory view of an essential part of an example of a drive belt of the present invention in a state of contact with a recording tape, and FIG. 2 is an essential part of another example of a drive belt of the present invention in a state of contact with a recording tape. FIG. 3 is an explanatory view of an example of a method for manufacturing a drive belt of the present invention, FIG. 4 is an enlarged explanatory view of an example of a mold used in the manufacturing method of FIG. 3, FIG. FIG. 6 is an enlarged explanatory view of another example of the mold used in the manufacturing method of FIG. 3, FIG. 6 is an explanatory view of another example of the method of manufacturing the drive belt of the present invention, and FIG. FIG. 8 is an explanatory plan view of an example of a grooved annular elastic resin sheet obtained by the manufacturing method of FIG. 6, and FIG. 8 is an explanatory view of an example of a belt-driven recording tape cartridge of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail. The drive belt according to the present invention is a conventional drive belt. It is characterized by improving the structure that the pressing force against the recording tape, which the knob has, tends to concentrate. According to the analysis of the present inventors, the pressing force is concentrated on the corners where the force is easily applied, such as both ends of the belt, and both sides of the groove, and the recording tape is damaged. For this reason, in the present invention, such a portion is formed in a round shape or steps are provided at both ends to suppress damage to the recording tape. First, the drive belt of the present invention will be described.

 One of the drive belts of the present invention has a plurality of grooves in the length direction of the surface on the side of the contact surface with the recording tape, and substantially has an edge at a portion in contact with the recording tape having a sectional shape. The feature is that there is no.

に相当する後退深さで且つベルト幅の 2〜20 %に 相当する幅の段差を形成して成ることを特徴とする。 Another one of the drive belts of the present invention is provided with a plurality of grooves in the length direction of the surface on the contact surface side with the recording tape, and at the upper and lower ends in the width direction on the contact surface side with the recording tape. Is the belt thickness

And a step having a retreat depth corresponding to 2 and a width corresponding to 2 to 20% of the belt width is formed.

 Still another one of the drive belts of the present invention is characterized in that a plurality of grooves having rounded corners are provided in the longitudinal direction of the surface on the contact surface side with the recording tape. As described above, the drive belt of the present invention includes: (a) a method of slicing an elastic resin cylindrical body having grooves formed in a circumferential direction on an outer peripheral surface according to a belt width; The annular elastic resin sheet having a plurality of concentric grooves formed in the circumferential direction can be manufactured by any method of twisting and stretching so that the grooves are located on the outer peripheral surface side, but the manufacturing process is relatively simple. Therefore, the drive belt according to the latter manufacturing method (b) is preferable because it has advantages such as excellent thickness accuracy.

The drive belt thickness is usually 80 to 200 im, the width is usually 3 to 10 mm, and the length is proportional to the length of the drive belt path in the tape cartridge. The number of grooves depends on the width of the drive belt, but is usually 2 to 10. In the present invention, the drive The thickness of the moving belt is the thickness including the groove, in other words, the distance between the contact surface and the opposite surface of the recording tape.

 The above-mentioned grooves are preferably formed by a groove transfer mold provided with groove-forming uneven portions, as described later in the method of manufacturing a drive belt. The shape of the groove formed by such a mold is determined by the heating press conditions (temperature and pressing force) at the time of groove transfer, the size of the concave and convex portions for forming the groove, the circle of the upper mold with respect to the annular concave portion of the lower mold. Although it depends on the penetration depth (pressing force) of the annular convex portion, the type of elastic resin (particularly the degree of elasticity), etc., the concave / convex groove does not necessarily follow the concave / convex portion for forming the groove.

 FIG. 1 shows a first configuration example of a drive belt according to the present invention. The drive belt shown in FIG. 1 has a structure in which a step having a specific depth is provided at both ends to suppress damage to the recording tape by both ends.

に相当する後退深さ （t₂) で且つベルト幅 （d の 2〜20 %に相当する幅 （d₂) の段差 （5)、 (5) を有し ている。 斯かる段差 （5)、 (5) は、 記録テープ （20) に対する圧接力が集中し 易い駆動ベルト （30) 端部の斯かる圧接加減を軽減して記録テープ （20) のダ メージを軽減する作用を有する。 The drive belt (30) shown in Fig. 1 has a belt thickness (t,) at the upper and lower ends in the width direction on the contact surface side with the recording tape (20).

Step retraction depth (t ₂₎ in and a width corresponding to 2-20% of the belt width (d (d ₂₎ which corresponds to (5), (having 5). Such a step (5) The functions (5) and (5) have an effect of reducing the pressure contact at the end of the drive belt (30) where the pressure contact force to the recording tape (20) tends to concentrate, thereby reducing the damage of the recording tape (20).

The steps (5) and (5) are formed horizontally, and the recessed depth (t ₂ ) that forms the steps (5) and (5) is 1/20 to 15Z20 of the belt thickness (t,). It is more preferable that the bottom of the steps (5) and (5) and the bottom of the groove (30a) have substantially the same height from the viewpoint of manufacturing the drive belt. If the width (d ₂ ) of the steps (5) and (5) is too large, it is effective to apply sufficient frictional force to the recording tape (20) to make the recording tape (20) run smoothly. It is not preferable because the contact area becomes small. The width (d ₂ ) of each of the steps (5) and (5) is preferably equivalent to 5 to 15% of the belt width (d,). FIG. 1 is a schematic explanatory view of the drive belt (30) of the present invention in a state of contact with the recording tape (20). In the cartridge, steps (5) and (5) are recorded. It does not mean that the tape (20) is non-contact.

 The drive belt (30) shown in FIG. 1 is a groove transfer mold having a shape shown in FIG. 4 described later, that is, an upper mold having an annular convex portion. It can be manufactured by using a groove transfer mold provided with concentric groove forming projections on the outer periphery and the innermost periphery. In FIG. 4, the groove-forming projections are represented by half the shape of the projection symbol.

 The drive belt (30) shown in FIG. 1 has three grooves (31) in the length direction of the surface on the contact surface side with the recording tape (20). (31) The corner (32) provided at the time of formation has a round shape. The drive belt (30) shown in Fig. 1 is in pressure contact with the recording tape (20).

The recording tape (20) runs due to the frictional force generated by running (30).

(31) The recording tape (20) is damaged by a number of corners applied during formation, resulting in data errors.

 Therefore, it is worthwhile to make many corners (32) round as described above. In the drive belt (30) shown in FIG. 1, both end corners (33) and (33) of the belt itself have a round shape for the same purpose as described above.

FIG. 2 shows a second configuration example of the drive belt according to the present invention. In the drive belt (30) shown in FIG. 2, the grooves at both ends provided in the first configuration example are not provided, and the corners at both ends of the belt are formed in a round shape instead. The drive belt (30) shown in FIG. 2 is a groove transfer mold having a shape shown in FIG. 5, which will be described later, that is, an upper mold having an annular convex portion. Can be manufactured by using a groove transfer mold having concentric groove forming recesses on the outermost and innermost circumferences. What In FIG. 5, the groove forming recesses are represented by half of the recessed symbols.

 The drive belt (30) shown in FIG. 2 is characterized in that a plurality of grooves having rounded corners are provided in the length direction of the surface on the side of the contact surface with the recording tape. In short, the drive belt (30) shown in FIG. 2 has three grooves (31) in the length direction of the surface on the contact surface side with the recording tape (20). Corner to be given

It is important that (32) is formed in a round shape.

 That is, the drive belt is in pressure contact with the recording tape, and the recording tape runs due to the frictional force generated by the travel of the drive belt, but the recording tape is damaged by a large number of corners applied when forming the grooves. , Resulting in data errors. Therefore, in the present invention, as described above, by providing the groove (31) in which the corner (32) is formed in a round shape, it is possible to prevent a tracking error and a data error. In the drive belt (30) shown in FIG. 2, according to a preferred embodiment of the present invention, both end corners (33) and (33) of the belt itself on the contact surface side with the recording tape (20) also have a round shape. It has been made to. There are two corners (33) and (33) at both ends of the belt itself, which are smaller in number than the corners (32) provided when the grooves (31) are formed. However, the corners at both ends (33) and (33) are thought to be due to the concentration of the pressing force against the recording tape (20), but are highly valued in the round shape because of the high probability of data error.

The degree of the round in the above round shape depends on the thickness of the drive belt (30), but is usually 10 to 100 zm, preferably 30 to 80 zm as the radius of curvature (R). If the R value is too large, an effective contact between the recording tape (20) and the recording tape (20) to exert sufficient frictional force to allow the recording tape (20) to run smoothly It is not preferable because the area becomes small.

 The round shape can be observed, for example, by measuring the surface roughness with a stylus-type surface roughness measuring device described later, and can also be observed from a micrograph of the cross-sectional shape of the drive belt. The R value can be calculated based on the above micrograph.

 In the present invention, the surface roughness (Ra) of the surface of the drive belt (30) on the contact surface side with the recording tape (20) (the surface of the convex portion of the concave / convex groove) is preferably 0.2 zm or less. . Ra above is measured in accordance with JIS B0601-1994 using a stylus type surface roughness measuring instrument under the conditions of a stylus tip radius of 2 / m, a load of 30 mg, and a cut-off value of 0.08 mm. Means

 In the present invention, the kind of the elastic resin constituting the drive belt (30) is not particularly limited, but an elastic resin which is easy to heat press, has a large elongation, and is excellent in abrasion resistance is preferable. In particular, an elastic resin having a difference in storage elastic modulus (Ε ′) measured at each temperature of 20 and 6 CTC within 20% is preferable. The above temperature ranges correspond to the expected minimum and maximum temperatures of the normal environment in which the tape cartridge is used, and the above storage modulus corresponds to the ratio of stress to strain on the drive belt.

The above viscoelastic properties are based on the following findings. That is, in general, a polymer substance has viscoelastic properties combining elasticity and viscosity.When a stress higher than the yield point is applied, viscous flow occurs due to slippage between molecular chains, and the stress is removed. However, it does not completely recover and permanent deformation remains, resulting in a decrease in elasticity. In the case of a driving belt in a tape cartridge, the recording tape is driven by the tension of the driving belt, but the tension of the driving belt in the tape is reduced due to the permanent deformation of the driving belt. Adversely affect the drive system. Therefore, to make the recording tape run stably, the drive belt The viscoelastic property is important as a characteristic of.

 In the present invention, the viscoelastic properties of the drive belt can be measured by using, for example, “Rheometrics Solids Analyzer (RSA II) J” manufactured by Rheometrics “Scientific” F.G. To set the storage elastic modulus (Ε ') and the loss elastic modulus, set the drive belt cut into strips into a measuring device and measure the stress, strain, and time delay while applying a frequency of 1 Hz. (Ε ''), loss tangent (tan 5) The smaller the change in storage modulus (Ε '), the smaller the change in mechanical properties, and therefore a constant stress (or constant strain) At this time, the change in stress (or change in strain) of the drive belt is small.

Therefore, the drive belt of the present invention the difference between the storage modulus measured at each temperature of 20 ° C and 60 ^e C (Ε ') is composed of more than 20% in a which elastic resin is excellent in fatigue resistance Since the recording tape can sufficiently withstand the frictional force that acts when the recording tape runs, it has the characteristic of low elongation. That is, in the tape cartridge provided with the drive belt having the above-mentioned viscoelastic properties, the decrease in the tension of the recording tape due to the decrease in the tension of the drive belt is small. The preferable range of the difference between the storage elastic modulus (Ε ′) measured at each temperature of 20 ° C and 6 (TC) is 10% or less.

 Specific examples of the elastic resin suitably used in the present invention include polyether urethane resin, polyester urethane resin, polycarbonate urethane resin, polyester resin, polyether resin, and butadiene resin. Further, a copolymer composed of polyethylene, polyether, butadiene and the like can also be used.

Next, a method for manufacturing the drive belt of the present invention will be described. The production method of the present invention comprises: a step of punching an annular elastic resin sheet from an elastic resin sheet; and a step of forming a plurality of concentric grooves in a circumferential direction of one flat portion of the annular elastic resin sheet. Twisting and stretching the grooved annular elastic resin sheet so that the groove is positioned on the outer peripheral surface side.

 The above punching step can be performed using a normal punching die (punch). The groove forming step and the stretching step can be performed, for example, in accordance with the procedures shown in FIGS. 3 (a) to 3 (d).

 In the groove forming step of the present invention, as shown in FIGS. 3 to 5, the upper mold (2) having the annular convex portion (21) is used as the upper mold (2). A groove transfer mold having a plurality of concavo-convex groove forming concavities and convexities (21a) and (21b) in the circumferential direction of the plane portion is used.

 As described above, the groove transfer mold shown in FIG. 4 is used to manufacture the drive belt (30) of the present invention shown in FIG. And a concentric convex portion (21b ') for forming a step (5) on the innermost periphery. The groove transfer mold shown in FIG. 5 is a drive belt (30) of the present invention shown in FIG. In order to manufacture this, a concentric groove forming recess (21a) is provided on the outermost and innermost circumferences of the annular flat portion of the convex portion of the upper mold (2).

First, as shown in FIG. 3 (a), a groove transfer comprising a lower mold (1) having an annular concave portion (la) and an upper mold (2) having an annular convex portion (21). Using a mold, place an annular elastic resin sheet (3) in the annular recess (la) of the lower mold (1). Then, as shown in Fig. 3 (b), the upper mold (2) The hot press working is performed by entering the annular convex part (21). The heat press working is usually performed under the conditions of a temperature of 120 to 150 ° C and a time of 1 to 10 seconds. When the drive belt having the configuration shown in FIG. 1 is formed, the receding depth (t ₂ ) at which the steps (5) and (5) are formed is determined by the annular convex portion (2a) of the upper mold (2). ) Can be changed by adjusting the height of the convex portion of the concentric groove forming concave / convex portion provided on the outermost periphery of the annular flat portion. Next, as shown in FIG. 3 (c), the annular elastic resin sheet (3) is released from the groove transfer mold, and is arranged at predetermined intervals as shown in FIG. 3 (d). A pair of rotating rods (4) and (4) is hung with an annular elastic resin sheet (3) and stretched about 1.5 to 2.5 times under high temperature conditions, for example, 80 to 150 times. And cool.

 In the present invention, as shown in FIGS. 1 and 2, a groove in which a corner (32) is formed in a round shape on the surface of the drive belt (30) on the contact surface side with the recording tape (20). When the (31) is provided, the entry of the convex part (21) of the upper mold (2) into the concave part (la) of the lower mold (1) must be performed between the lower mold (1) and the upper mold (2). Heat press processing shallow so that one side of the party does not touch.

 According to the heating press as described above, since the concave and convex portions of the groove forming concave and convex portions (21a) and (21b) are roughly transferred to the annular elastic resin sheet (3), the groove (31) is formed. The sometimes provided corner (32) is formed in a round shape and does not become angular. Also, the lower mold (1) and the upper mold (2) are brought into contact with one side of the party, but the depth of the concave portion (la) of the lower mold (1) is 21) If it is deeper, the same rough transfer as above can be performed.

 The penetration depth of the upper mold (2) and the depth of the recess (la) of the lower mold (1) depend on the size of the groove-forming unevenness, the type of elastic resin (particularly the degree of elasticity), Since it depends on the thickness of the annular elastic resin sheet (3) and the like, it is appropriately selected in consideration of these factors so as to obtain a desired R value. The drive belt of the present invention can be manufactured by using an upper mold having a groove-forming uneven portion having a desired R value in addition to the above method. However, such a mold is not economically advantageous because of the high cost of precision machining.

Next, another method for manufacturing the driving belt of the present invention will be described. According to another manufacturing method of the present invention, at least one surface of the elastic resin sheet has a plurality of rounded corners. Forming a concentric groove, and punching an annular elastic resin sheet from the elastic resin sheet having the concentric groove formed thereon so that a plurality of concentric grooves are formed in the circumferential direction of the plane portion. And a step of twisting and stretching the grooved annular elastic resin sheet so that the groove is positioned on the outer peripheral surface side.

 The above-described concentric groove forming step can be performed using, for example, a roll transfer device, and the above-described punching step can be performed using a punching machine equipped with a normal punching die (punch). I can do it. The stretching step can be performed in the same manner as in the above-described manufacturing method (see FIG. 3 (d)).

 First, as shown in FIG. 6, an elastic resin sheet (100) is transported by a transport roll (not shown), and a transfer roller having a nip roller (101) and a plurality of concentric grooves (103) on the surface. A plurality of concentric grooves (104) having rounded corners are formed on one side of the elastic resin sheet (100) by the roll transfer device comprising (102).

 The round shape of the corner of the concentric groove (104) is adjusted by adjusting the pressing force between the nip roller (101) and the transfer roller (102) based on the same principle as in the case of the heating press method in the above-mentioned manufacturing method. It is formed. At this time, if necessary, the nip roller (101) and / or the transfer roller (102) may be heated to an appropriate condition as in the case of the above-mentioned hot press working.

Next, a punching machine (105) is used to form a plurality of concentric grooves from the elastic resin sheet (100) on which the concentric grooves (104) are formed so that a plurality of concentric grooves are formed in the circumferential direction of the plane portion. Punch out the annular elastic resin sheet (106). That is, punching is performed so as to be concentric with the center of the pattern of the concentric grooves (104) to obtain a grooved annular elastic resin sheet (106) as shown in FIG. Then, in the same manner as shown in FIG. 3 (d), the grooved annular elastic resin sheet (106) is twisted so that the groove is located on the outer peripheral surface side. And stretch. As the conditions at this time, the same conditions as in the above-described manufacturing method are employed.

 The drive belt of the present invention obtained as described above is stretched about 1.0 to 2.0 times and mounted on a cartridge to be used as a drive belt.

 Next, the tape cartridge of the present invention will be described with reference to the accompanying drawings. FIG. 6 is a partially omitted explanatory view of an example of the tape cartridge of the present invention, and shows a state in which the tape cartridge (10) is loaded into the drive (50) from the opening on the front surface (14) side. Is shown. The drive (50) is a device for recording or reproducing information, and the information is magnetically or optically recorded on a recording tape (20).

 The tape cartridge of the present invention basically includes a pair of tape reels (15) and (16), a recording tape (20) having both ends wound around the pair of tape reels, and a recording tape (20). Guide means (22), (24), (25), (26) for guiding the traveling route and a plurality of support means (32), (34), (36), (38) allow the inner surface to move. It consists of a drive belt (30) that is supported and whose outer surface is in constant contact with the recording tape (20) at at least two places.

 The tape cartridge (10) includes a base plate (18) made of metal such as aluminum, a pair of tape reels (15) and (16) vertically erected on the base plate, and recording tape guide means (22). , (24), (25), (26) and the plurality of drive belt support means (32), (34), (36), (38), and the housing (13) arranged on the base plate (18). It is mainly composed.

The housing (13) is usually made of plastic, has grooves on both sides, and is provided at both ends of the drive (50) when the tape cartridge (10) is loaded into the drive (50). L-shaped truck (52) is house The tape cartridge (10) is guided into the drive (50) by fitting into the grooves on both ends of the tape (13). If the drive (50) is completely loaded with the tape cartridge (10), the end of the drive (50) will be in the position represented by the reference (60), but in FIG. The housing (13) and a part of the housing (13) are not shown.

 —The pair of tape reels (15) and (16) has a rotating shaft at the center of each, and both ends of the recording tape (20) are wound around the above-mentioned tape reels (15) and (16). (11) and (12) are configured. In the pair of tape reels (15) and (16), each rotation center is located on a different virtual vertical line with respect to the front surface (14), and the vertical distance from one front surface (14) to the rotation center is the other. It is arranged to be larger than As a result, the size of the base plate (18) in the longitudinal and width directions can be reduced to make it compact, and the number of turns of the recording tape (20) on the tape reels (15) and (16) can be increased. The recording capacity can be increased by enlarging the tape packs (11) and (12).

 The recording tape guide means (22), (24), (25), and (26) are usually constituted by metal pins, and have a function of guiding the recording tape (20) along a predetermined traveling path. Have. The travel path of the recording tape (20) includes the front surface (14) of the tape cartridge (10), and when the tape cartridge (10) is loaded in the drive (50), the opening on the front surface (14) side. The recording tape (20) is arranged so that the recording tape (20) is in contact with the reproducing magnetic head (56) arranged on the drive (50) side.

The plurality of drive belt support means (32), (34), (36), and (38) are usually composed of a metal guide bin and a resin rotating roll disposed around the guide bin. ). That is, the inner surface of the drive belt (30) is movably supported by the plurality of drive belt support means (32), (34), (36), and (38). At the same time, its outer surface is in constant contact with the recording tape (20) in at least two places.

 One of the plurality of drive belt supporting means ((38) in the illustrated example) is disposed on the front surface (14) side of the tape cartridge (10) and has a function as a drive roller. When the tape cartridge (10) is loaded into the (50), one of the plurality of drive belt support means (38) is provided at the opening on the front surface (14) side by the drive roller disposed on the drive (50) side. (58). In FIG. 6, reference numeral (28) indicates a space between the recording tape (20) and the reproducing magnetic head (56), and reference numeral (53) indicates a door.

 The tape cartridge having the above structure is known, for example, as disclosed in U.S. Pat. No. 4,262,860, and other details can be referred to the above U.S. Pat.

 In the present invention, as described above, the drive belt (30) is provided with a plurality of grooves having rounded corners in the longitudinal direction of the surface on the contact surface side with the recording tape. In addition to preventing air from being drawn into the contact surface with the recording tape (20), tracking errors are prevented, and there are few angular portions on the drive velorette (30) pressed against the recording tape (20). Tape (20) damage is reduced and data errors are prevented. In addition, at each end under the width improvement on the side of the contact surface with the recording tape, a step having a receding depth corresponding to 1200 to 1920 of the belt thickness and a width corresponding to 2 to 20% of the belt width is provided. In this case, the pressure applied to the end of the drive belt (30) against the recording tape (20) is reduced, that is, the damage to the recording tape (20) is reduced and data errors are further prevented.

Further, in the drive belt of the present invention, by using a material having a specific viscoelastic property, the change in tension is small, the running stability is excellent, and reading and writing can be performed accurately. Can be. In particular, the above effects of the present invention are remarkable in a tape cartridge in which a pair of tape reels is arranged at a specific position to increase the capacity.

 That is, in a high-capacity tape cartridge, since the tape pack is large, a high pressure contact state is required due to a sufficient contact frictional force, and a long drive belt is required. In the case of a belt, data errors are more likely to occur due to both ends of the belt, which apply a more concentrated pressing force to the recording tape, and corners applied when forming the grooves, and a slight change in the tension of the drive belt. Although the running stability of the recording tape is greatly affected by this, the tape cartridge (10) of the present invention has a reduced pressure contact with the recording tape (20) due to its end, a reduced angular portion, and a lower tension. Drive belts with little change (Fig. 1 configuration) or drive belts with few angular portions and little change in tension (Fig. 2 configuration) Since that example, even in the tape force one cartridge high capacity type such as described above, the recording tape (20) durability and running stability excellent, read or write accurately performed it is possible.

 Example

 Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention. In the following examples, evaluation was performed by the following method.

 (1) Storage belt storage elastic modulus (Ε '):

 Using a Rheometrics Solids Analyzer (RSA II) manufactured by Rheometrics' Scientific F ♦ Co., Ltd., cut a 20 mm length sample from the drive belt and do not loosen it between the chucks of the measuring device. And measured under the condition of a frequency of 1 Hz.

(2) The radius of curvature of the corners (groove corners) and belt ends given at the time of groove formation R: The calculation was based on a micrograph (magnification: 75) of the cross section of the drive belt.

(3) Surface roughness (Ra) of the drive belt on the contact surface side with the recording tape:

 In accordance with JIS B0601-1994, measurement was performed using a stylus type surface roughness measuring instrument under the conditions of a stylus tip radius of 2 m, a load of 30 mg, and a cut-off value of 0.08 mm.

(4) Occurrence of error in cartridge:

 The operation of writing data once to the recording tape and reading it twice was performed continuously for 60 hours. Using a Colorado Memory System QIC cartridge drive, the occurrence of errors in the written data was measured. Then, it was expressed as the number of errors per lm length in one track.

 (5) Drive belt tension:

 The belt tension before and after 5,000 runs between the pair of drive belt support means (36) and (34) shown in FIG. 8 was measured. As a measuring device, "TENTELO METERJ (brand name, manufactured by TENTEL CORP.)" Was used.

 Example 1

 As the elastic resin, 100 parts by weight of polycaprolactone (molecular weight: 2000): 200 parts by weight of methyl diisocyanate (MDI): a polyurethane resin consisting of 100 parts by weight of 1,4-butanediol (1,4-BG), After 6% by weight of carbon black was added to the mixture and kneaded, it was melt-extruded to obtain a 180 / zm thick sheet. Next, an annular elastic sheet having an inner diameter of 16.2 mm and an outer diameter of 27.2 mm was punched out of this sheet using a punching die (punch).

Next, a lower mold having an annular concave portion with an inner diameter of 16.2 mm and an outer diameter of 27.2 mm, an annular convex portion, and a concentric groove forming concave and convex portion on the annular flat portion of the convex portion were provided. The grooves were transferred to the above annular elastic sheet in the following manner by a hot press using a groove transfer mold composed of an upper mold. As shown in FIG. 4, the upper mold has a convex part having a width of 0.5 mm and a height of 1.0 mm at the outermost and innermost circumferences of the annular flat part of the convex part. A mold having a concave-convex portion and a concave width of 0.5 mm was used. Then, place an annular elastic sheet in the concave part of the lower mold, heat the upper mold to 130 ° C, and insert the convex part of the upper mold shallowly into the concave part of the lower mold for 1-2 seconds. The annular elastic sheet was pressed to transfer the three annular grooves having rounded corners to the annular elastic sheet, and steps (horizontal portions) were formed at both ends in the width direction of the annular elastic sheet.

 Next, in the environment where the above-mentioned grooved annular elastic resin sheet is exposed to hot air, the groove is stretched so that the groove is located on the outer peripheral surface side and the outer periphery becomes 200 mm, and has a width of 3.8 mm and a thickness of 107 ^ m. A drive belt having a sectional shape as shown in FIG. 1 and FIG. 2 was obtained. The dimensional relationship of the step (horizontal part), the radius of curvature (R / zm) of the corner part (groove corner part) and the belt edge given at the time of groove formation, and the surface roughness of the drive belt on the contact surface side with the recording tape Table 1 shows the measurement results of (Ra) and the respective storage elastic moduli (Ε ′) at 20 ° C. and 60 ° C.

 The radius of curvature R (/ m) of the corners (groove corners) and belt ends provided when grooves are formed, the surface roughness (Ra) of the drive belt on the contact surface side with the recording tape, 20 ° C and 60 ° Table 1 shows the measurement results of each storage elastic modulus (Ε ') with C.

 Next, a tape cartridge as shown in Fig. 8 was made by stretching the above drive belt between the drive roller and a pair of corner rollers while stretching it about 1.5 times, and an error in the written data occurred. The situation was measured. The tension of the drive belt before and after running 5000 times was measured. Table 1 shows the results.

 Example 2

In Example 1, as the elastic resin, 100 parts by weight of polycaprolactone (molecular weight: 2000): 200 parts by weight of isophorone diisocyanate (IPDI): 100 parts by weight of 1,4-butanediol (1,4-BG) Except for using polyurethane resin consisting of In the same manner as in Example 1, a drive belt and a tape cartridge were prepared and evaluated. The results are shown in Table 1.

 Example 3

 As shown in Fig. 5, the upper mold has concave parts with a width of 0.5 mm and a height of 1.0 mm on the outermost and innermost circumferences of the annular flat part of the convex part, and concave and convex parts between these concave parts. A drive belt and a tape cartridge were prepared and evaluated in the same manner as in Example 1 except that a mold having a recess width of 0.5 mm was used. Table 2 shows the results.

 Example 4

 In Example 3, 100 parts by weight of polycaprolactone (molecular weight: 2000): 200 parts by weight of isophorone diisocyanate (IPDI): 100 parts by weight of 1,4-butanediol (1,4-BG) as an elastic resin A drive belt and a tape cartridge were prepared and evaluated in the same manner as in Example 1 except that a polyurethane resin consisting of The results are shown in Table 2.

 Comparative Example 1

In Example 1, a polyurethane composed of 200 parts by weight of polypropylene glycol (molecular weight: 2000): 100 parts by weight of tolylene diisocyanate (TDI): 100 parts by weight of 1,4-butanediol (1,4-BG) as an elastic resin. The upper mold is made of resin, and has a concave portion with a width of 0.5 mm and a height of 1.0 mm at the outermost and innermost circumferences of the annular flat portion of the convex portion. When a groove with a recess width of 0.5 mm is used, and when the groove is transferred to the annular elastic sheet, the convex part of the upper mold is inserted deeply into the concave part of the lower mold, so that the corner given when forming the groove is formed. A drive belt and a tape cartridge were prepared and evaluated in the same manner as in Example 1 except that the portion was squared and no step (horizontal portion) was formed at both ends in the width direction of the annular elastic sheet. Was. The results are shown in Table 1. Comparative Example 2

 In Example 1, the elastic resin was composed of 400 parts by weight of polypropylene glycol (molecular weight: 2000): 300 parts by weight of tolylene diisocyanate (TDI): 100 parts by weight of 1,4-butanediol (1,4-BG) Using a polyurethane resin, the upper mold has a concave part with a width of 0.5 mm and a height of 1.0 mm at the outermost and innermost circumferences of the annular flat part of the convex part, and a concave and convex part between these concave parts When a groove is transferred to an annular elastic sheet using a mold with a concave width of 0.5 mm, the convex part of the upper mold is inserted deeply into the concave part of the lower mold, so that it is given when the groove is formed. A drive belt and a tape cartridge were prepared and evaluated in the same manner as in Example 1 except that the corners were squared and no steps (horizontal portions) were formed at both ends in the width direction of the annular elastic sheet. went. The results are shown in Table 1.

 Comparative Example 3

 Example 3 Example 3 was repeated except that when the grooves were transferred to the annular elastic sheet, the convex portions of the upper mold were deeply inserted into the concave portions of the lower mold, so that the corners provided at the time of forming the grooves were squared. A drive belt and a tape cartridge were prepared in the same manner as described above and evaluated. The results are shown in Table 2.

 Comparative Example 4

Example 4 Example 4 was repeated except that when the groove was transferred to the annular elastic sheet, the convex part of the upper mold was deeply inserted into the concave part of the lower mold, so that the corner provided at the time of forming the groove was squared. A drive belt and a tape cartridge were prepared in the same manner as described above and evaluated. The results are shown in Table 2. table 1

Example Comparative example

1 2 1 2 Step recession depth (t ₂ ) (fi m) 10 10 ― ― Step width (d ₂ ) (mm) 0.5 0.5 ― ― Curvature radius of groove corner R (^ m) 30 30 ― ― Radius of curvature of belt end R (β τη) 30 30 ― ― Belt surface roughness Ra (μ.m) 0.2 0.2 0.2 0.2 Storage modulus (X 10 ⁷ Pa)

 20 ° C 1.24 6.87 12.90 7.21

60. C 1.21 5.53 5.67 2.85 Decrease in storage modulus (%) 2.42 19.51 56.05 60.47 Data error occurrence 2 2 30 30 <Change in belt tension (ounce)>

 0 times 12.5 12.3 12.2 11.8

5000 times 12.4 12.1 8.9 7.7

Table 2

Discussion Comparative example

 o 4 O 4 Mizozuki ¾ ^ ffl ^ + te n

m) OU on hen

 n n ノ レ ノ レ ^ ¾ffi] fE a β vi) U. ά U. L U. L U. if 威 弾 伞 x 丄 υ ra)

 20. C 1.24 687 2.90 7.21

60 ° C 1.21 5 · 53 5.67 2.85 Decrease in storage modulus (%) 2.42 19.51 6.05 60.47 Data error occurrence 3 3 30 30 Change in belt tension (ounce)

 0 times 12.5 123 12.2 11.8

5000 times 12.4 12.1 8.9 7.7

Industrial applicability

 According to the present invention described above, a recording tape drive belt improved to reduce the occurrence of data errors in a recording tape, a method of manufacturing the drive belt, and a belt-driven recording tape cartridge including the drive belt are provided. Provided.

Claims

The scope of the claims 1. A driving belt in a belt-driven recording tape force cartridge in which a recording tape is caused to travel by a driving belt, the recording belt having a plurality of grooves in a length direction of a surface on a contact surface side with the recording tape, and A drive belt characterized in that there is substantially no edge in a portion of the cross section that comes into contact with the recording tape. 2. The recording tape drive belt according to claim 1, comprising an elastic resin having a difference in storage elastic modulus (Ε ′) measured at each temperature of 20 ^e C and 60 at 20% or less. 3. A drive belt in a belt-driven recording tape cartridge in which the recording tape runs by means of a drive belt. A plurality of grooves are provided along the length of the surface on the contact surface side with the recording tape, and At each of the upper and lower ends in the width direction on the contact surface side, a step having a receding depth equivalent to 1Ζ200 to 19Ζ20 of the belt thickness and a width equivalent to 2 to 20% of the belt width shall be formed. Characteristic recording tape drive belt. 4. The recording tape driving belt according to claim 3, wherein the bottom of the step and the bottom of the groove are substantially at the same height.  5. The recording tape drive belt according to claim 3, wherein a corner provided at the time of forming the groove has a round shape.  6. An endless belt formed by twisting and stretching an annular elastic resin sheet having a plurality of concentric grooves formed in the circumferential direction of one of the flat portions so that the grooves are located on the outer peripheral surface side. The recording tape drive belt of range 3.  7. The recording tape drive belt according to claim 3, comprising an elastic resin having a difference in storage elastic modulus (Ε ′) measured at each temperature of 2 CTC and 60 C of 20% or less. 8. A method for manufacturing a drive belt in a belt-driven recording tape cartridge in which a recording tape is caused to travel by a drive belt. Punching a conductive resin sheet, forming a plurality of concentric grooves in the circumferential direction of one flat portion of the annular elastic resin sheet, and forming the grooved annular elastic resin sheet on the outer peripheral surface side. And a step of stretching by twisting so as to be positioned. In the groove forming step, at least one of a lower mold having an annular concave portion, an annular flat portion having an annular convex portion, and an annular flat portion of the convex portion is provided. A method for manufacturing a recording tape drive belt, comprising using a groove transfer mold comprising an upper mold having concentric groove-forming projections on the outermost and innermost circumferences.  9. The method for manufacturing a recording tape drive belt according to claim 8, wherein the hot press working is performed by making the protrusion of the upper mold into the recess of the lower mold shallow. 10. A pair of tape reels, a recording tape having both ends wound around the pair of tape reels, a guide means for guiding the recording tape to a predetermined traveling path, and an inner surface thereof moved by a plurality of support means. In a belt-driven recording tape cartridge provided with a recording tape driving belt which is supported so as to be able to always contact the recording tape at least at two places, the driving belt is provided on the side in contact with the recording tape. A plurality of grooves are provided in the length direction of the surface, and the width of the contact surface side with the recording tape is improved.

And a step having a width corresponding to 2 to 20% of the belt width at a receding depth corresponding to the above.  11. The pair of tape reels are arranged so that each rotation center is located on a different virtual vertical line with respect to the front surface of the cartridge, and the vertical distance from one front surface to the rotation center is larger than the other. 11. The tape force cartridge according to claim 10, wherein 12. The drive belt in a belt-driven recording tape force cartridge in which the recording tape is run by the drive belt, and the length of the surface on the contact surface side with the recording tape A recording tape drive belt, comprising a plurality of grooves each having a rounded corner portion.  13. The recording tape drive belt according to claim 12, wherein both end corners of the belt itself on the contact surface side with the recording tape are formed in a round shape. 14. The recording tape drive belt according to claim 12, wherein the belt is made of an elastic resin having a difference in storage elastic modulus (Ε ′) measured at each temperature of 20 ° C. and 60 within 20%. 15. A method of manufacturing a drive belt for a belt-driven recording tape cartridge in which a recording tape is caused to travel by a drive belt, comprising: a step of punching an annular elastic resin sheet from an elastic resin sheet; Forming a plurality of concentric grooves in the circumferential direction of one of the flat portions, and twisting and stretching the grooved annular elastic resin sheet so that the grooves are positioned on the outer peripheral surface side. In the groove forming step, a lower mold having an annular concave portion, and a plurality of concentric groove forming concave and convex portions having an annular convex portion and extending in the circumferential direction of an annular flat portion of the convex portion are provided. A groove transfer die comprising a lower die provided with the lower die, and a hot press process performed by making the protrusion of the upper die into the recess of the lower die shallowly to perform the heat press working. Production method  16. A method of manufacturing a drive belt in a belt-driven recording tape cartridge in which a recording tape is caused to travel by a drive belt, the method comprising: forming a plurality of concentric grooves having rounded corners on at least one surface of an elastic resin sheet. A step of punching an annular elastic resin sheet from the elastic resin sheet having the concentric grooves formed thereon so as to form a plurality of concentric grooves in a circumferential direction of a plane portion thereof; Twisting and stretching the sheet so that the groove is positioned on the outer peripheral surface side. A method for manufacturing a recording tape drive belt, comprising: 17. A pair of tape reels and both ends wound around the pair of tape reels A recording tape, a guide means for guiding the recording tape along a predetermined traveling route, and a plurality of supporting means whose inner surface is movably supported and whose outer surface constantly contacts the recording tape at at least two places. In the belt-driven recording tape cartridge provided with a recording tape driving belt, the driving belt is provided with a plurality of grooves whose corners are round in the longitudinal direction of the surface on the contact surface side with the recording tape. A belt-driven recording tape force cartridge, characterized in that:  18. A pair of tape reels are positioned so that each center of rotation is on a different imaginary vertical line with respect to the front surface of the cartridge, and the vertical distance from one front surface to the center of rotation is greater than the other. The tape cartridge according to claim 17, wherein