The present invention provides a winding core which is lightweight, and which has an excellent dimensional accuracy and deflection reducing property in a long length product. Provided is a winding core obtained by molding a resin composition comprising: at least one type of amorphous resin (A) selected from a styrene resin, a polycarbonate, a polyarylate, a polyphenylene oxide and a polysulfone; a polylactic acid (B); and an inorganic filler; wherein the resin composition includes: from 50 to 80 parts by mass of the amorphous resin (A), and from 20 to 50 parts by mass of the polylactic acid resin (B) (wherein the total amount of the amorphous resin (A) and the polylactic acid (B) is 100 parts by mass). Preferably, the winding core further includes from 10 to 40 parts by mass of the inorganic filler (C).

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.

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.

A tape media cartridge includes a cartridge housing having a standard form factor, a cartridge reel that is coupled to and retained within the cartridge and a tape media. The tape media can be selectively wound onto the cartridge reel between a fully wound state, a partially wound state and an unwound state. The tape media forms a media hollow cylinder having a media outer diameter and a media inner diameter that varies depending upon the state of the tape media. When the tape media is in the fully wound state, the tape media has a ratio of the media outer diameter to media inner diameter of at least approximately 95:43. The cartridge housing can include a side wall having a wall center and wall edge, the side wall having a side wall thickness that gradually increases from the side wall center to the side wall edge.

[Object] Provided is a technology that is capable of further improving a recording density of data. [Solving Means] A magnetic recording medium according to the present technology is a magnetic recording medium in a shape of a tape that is long in a longitudinal direction and is short in a width direction, the medium including: a base material; a magnetic layer; and a non-magnetic layer that is provided between the base material and the magnetic layer, and contains one or more types of non-magnetic inorganic particles, in which the magnetic layer includes a data band long in the longitudinal direction in which a data signal is to be written, and a servo band long in the longitudinal direction in which a servo signal is written, and in the magnetic layer, a degree of vertical orientation is greater than or equal to 65%, a half width of a solitary waveform in a reproduction waveform of the servo signal is less than or equal to 195 nm, and a thickness of the magnetic layer is less than or equal to 90 nm, and the non-magnetic layer contains at least Fe-based non-magnetic particles as the non-magnetic inorganic particles, and in the non-magnetic layer, an average particle volume of the Fe-based non-magnetic particles is less than or equal to 2.0×10.sup.−5 μm.sup.3, and a thickness of the non-magnetic layer is less than or equal to 1.1 μm.

A tape media cartridge includes a cartridge housing having a standard form factor, a cartridge reel that is coupled to and retained within the cartridge and a tape media. The tape media can be selectively wound onto the cartridge reel between a fully wound state, a partially wound state and an unwound state. The tape media forms a media hollow cylinder having a media outer diameter and a media inner diameter that varies depending upon the state of the tape media. When the tape media is in the fully wound state, the tape media has a ratio of the media outer diameter to media inner diameter of at least approximately 95:43. The cartridge housing can include a side wall having a wall center and wall edge, the side wall having a side wall thickness that gradually increases from the side wall center to the side wall edge.

A tape media cartridge includes a cartridge housing having a standard form factor, a cartridge reel that is coupled to and retained within the cartridge and a tape media. The tape media can be selectively wound onto the cartridge reel between a fully wound state, a partially wound state and an unwound state. The tape media forms a media hollow cylinder having a media outer diameter and a media inner diameter that varies depending upon the state of the tape media. When the tape media is in the fully wound state, the tape media has a ratio of the media outer diameter to media inner diameter of at least approximately 95:43. The cartridge housing can include a side wall having a wall center and wall edge, the side wall having a side wall thickness that gradually increases from the side wall center to the side wall edge.

A hub includes a hub body around which a magnetic tape is wound, and a noncontact storage medium provided in the hub body, in which the noncontact storage medium stores hub specification information for specifying the hub body, and the hub specification information is associated with hub change characteristic information indicating a change characteristic of the hub body.