A noncontact communication medium includes a processor, and a memory incorporated in or connected to the processor, and performs noncontact communication with an external communication device. The memory has a storage block where information regarding an attribute of the noncontact communication medium is stored and that includes a plurality of storage fields. The plurality of storage fields include a specification-independent storage field where information independent of a specification of a magnetic tape cartridge, in which the noncontact communication medium is mounted, is stored. The processor is configured to write accompanying information regarding the magnetic tape cartridge in the specification-independent storage field in response to an instruction given from the external communication device to the noncontact communication medium by the noncontact communication.

A noncontact communication medium includes a processor, and a memory incorporated in or connected to the processor, and performs noncontact communication with an external communication device. The memory has a storage block where information regarding an attribute of the noncontact communication medium is stored and that includes a plurality of storage fields. The plurality of storage fields include a specification-independent storage field where information independent of a specification of a magnetic tape cartridge, in which the noncontact communication medium is mounted, is stored. The processor is configured to write accompanying information regarding the magnetic tape cartridge in the specification-independent storage field in response to an instruction given from the external communication device to the noncontact communication medium by the noncontact communication.

A cartridge according to the present technology includes: a cartridge case; and a memory. The cartridge case houses a magnetic tape. The memory is provided in the cartridge case, the memory storing information before data recording by the magnetic tape, the information being for adjusting, during data recording or during data reproduction by the magnetic tape, a width of the magnetic tape.

A cartridge according to the present technology includes: a cartridge case; and a memory. The cartridge case houses a magnetic tape. The memory is provided in the cartridge case, the memory storing information before data recording by the magnetic tape, the information being for adjusting, during data recording or during data reproduction by the magnetic tape, a width of the magnetic tape.

A tape is prevented from moving in a width direction and the tape is prevented from being damaged in a state in which the tape is wound around a tape reel. There is provided a tape reel including: a cylindrical portion around which a tape is wound; a first flange annularly projecting toward an outer side in a radial direction of the cylindrical portion from the cylindrical portion; and a second flange separated from the first flange in an axial direction of the cylindrical portion and annularly projecting toward the outer side in the radial direction from the cylindrical portion, in which a distance between the first flange and the second flange becomes narrower while extending toward the outer side in the radial direction, and a bending elastic modulus of the first flange is smaller than a bending elastic modulus of the second flange.

A tape is prevented from moving in a width direction and the tape is prevented from being damaged in a state in which the tape is wound around a tape reel. There is provided a tape reel including: a cylindrical portion around which a tape is wound; a first flange annularly projecting toward an outer side in a radial direction of the cylindrical portion from the cylindrical portion; and a second flange separated from the first flange in an axial direction of the cylindrical portion and annularly projecting toward the outer side in the radial direction from the cylindrical portion, in which a distance between the first flange and the second flange becomes narrower while extending toward the outer side in the radial direction, and a bending elastic modulus of the first flange is smaller than a bending elastic modulus of the second flange.

There is provided a mold for molding a tape reel that is made of a resin and that includes a cylindrical portion, a bottom portion formed on a proximal end side of the cylindrical portion, and a plurality of through holes penetrating the bottom portion and arranged in a peripheral direction of the cylindrical portion, the mold including: a bottom surface that is used to form the bottom portion; a tubular surface that is used to form the cylindrical portion; and a plurality of projecting portions that protrude from the bottom surface and are used to form the plurality of through holes, respectively, in which, in the tubular surface, a first portion corresponding to a portion between the projecting portions adjacent to each other in the peripheral direction, among the plurality of projecting portions, has a shape that bulges toward a radially outer side of the bottom surface than a second portion corresponding to the projecting portion.

There is provided a mold for molding a tape reel that is made of a resin and that includes a cylindrical portion, a bottom portion formed on a proximal end side of the cylindrical portion, and a plurality of through holes penetrating the bottom portion and arranged in a peripheral direction of the cylindrical portion, the mold including: a bottom surface that is used to form the bottom portion; a tubular surface that is used to form the cylindrical portion; and a plurality of projecting portions that protrude from the bottom surface and are used to form the plurality of through holes, respectively, in which, in the tubular surface, a first portion corresponding to a portion between the projecting portions adjacent to each other in the peripheral direction, among the plurality of projecting portions, has a shape that bulges toward a radially outer side of the bottom surface than a second portion corresponding to the projecting portion.

An object of the present invention is to provide a magnetic recording medium capable of suppressing a dimensional change in a width direction by setting the water vapor transmission rate within a specific range.

The present technology provides a magnetic recording medium having a tape shape, the magnetic recording medium including: a magnetic layer; a nonmagnetic layer; a base layer; and a back layer in this order, in which the magnetic layer and the nonmagnetic layer are in contact with each other, the nonmagnetic layer and the base layer are in contact with each other, an average thickness of the magnetic recording medium is 5.74 μm or less, a Young's modulus in an MD direction (longitudinal direction) of the base layer is 5.9 GPa or less, and a water vapor transmission rate of the magnetic recording medium, measured according to a Lyssy method, is 2.93 g/m.sup.2.Math.day or less. The Young's modulus in the MD direction of the base layer (longitudinal direction) is 5.3 GPa or less. A humidity expansion coefficient β at a temperature of 10° C. is 6.5 ppm/% RH or less.

An object of the present invention is to provide a magnetic recording medium capable of suppressing a dimensional change in a width direction by setting the water vapor transmission rate within a specific range.

The present technology provides a magnetic recording medium having a tape shape, the magnetic recording medium including: a magnetic layer; a nonmagnetic layer; a base layer; and a back layer in this order, in which the magnetic layer and the nonmagnetic layer are in contact with each other, the nonmagnetic layer and the base layer are in contact with each other, an average thickness of the magnetic recording medium is 5.74 μm or less, a Young's modulus in an MD direction (longitudinal direction) of the base layer is 5.9 GPa or less, and a water vapor transmission rate of the magnetic recording medium, measured according to a Lyssy method, is 2.93 g/m.sup.2.Math.day or less. The Young's modulus in the MD direction of the base layer (longitudinal direction) is 5.3 GPa or less. A humidity expansion coefficient β at a temperature of 10° C. is 6.5 ppm/% RH or less.