# US 12,009,017 B2 · Magnetic tape cartridge and magnetic recording and reproducing device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,009,017 B2 - Document ID: US12009017B2 - Status: Granted - Kind: B2 - Application number: 17/730,763 - Filed: 2022-04-27 - Published: 2022-11-10 - Granted: 2024-06-11 - Earliest claimed: 2021-04-28 - Assignees: FUJIFILM Corporation - Applicants: FUJIFILM Corporation - Inventors: Norihito Kasada; Yusuke Kaneko - Web page: https://patentgrep.com/patent/US12009017B2 ## CPC - G11B 5/5928: {Longitudinal tracks} - G11B 5/584: for track following on tapes - G11B 5/70678: {Ferrites} - G11B 5/7356: {comprising non-magnetic particles in the back layer, e.g. particles of TiO2, ZnO or SiO2} - G11B 5/78: Tape carriers - G11B 23/107: using one reel or core, one end of the record carrier coming out of the magazine or cassette - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) ## Abstract In the magnetic tape, in a case where a maximum value of an absolute value of a difference between a servo band spacing obtained before storage in an environment of a temperature of 32° C. and relative humidity of 55% and a servo band spacing obtained after storage in the environment for a storage time T is set to A, and T is defined as 24 hours, 48 hours, 72 hours, 96 hours, or 120 hours, a medium life calculated by a linear function of A and a logarithm logeT of T, that are derived from a value of A and a value of the logarithm logeT of T obtained for each T is 3 years or longer. The medium life is T in a case where the A satisfies Equation 1: A=1.5−B. ## Claims ### Claim 1 A magnetic tape cartridge comprising: a medium, which is a magnetic tape, wherein the magnetic tape is wound around a cartridge reel and accommodated in the magnetic tape cartridge, the magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder, the magnetic layer includes a plurality of servo bands, in a case where a maximum value of an absolute value of a difference between a servo band spacing obtained before storage in an environment of a temperature of 32° C. and relative humidity of 55% and a servo band spacing obtained after storage in the environment for a storage time T is set to A, a unit of A is μm, and T is defined as 24 hours, 48 hours, 72 hours, 96 hours, or 120 hours, a medium life calculated by a linear function of A and a logarithm logeT of T, that are derived from a value of A and a value of the logarithm logeT of T obtained for each T is 3 years or longer, the medium life is the storage time T when A satisfies Equation 1: A=1.5−B, and (Equation 1) the B is a value calculated by multiplying a difference between a maximum value and a minimum value of the servo band spacings obtained in each of the following five environments of a temperature of 16° C. and relative humidity of 20%, a temperature of 16° C. and relative humidity of 80%, a temperature of 26° C. and relative humidity of 80%, a temperature of 32° C. and relative humidity of 20%, and a temperature 32° C. and relative humidity of 55%, by ½, and the unit is μm. ### Claim 2 (depends on 1) The magnetic tape cartridge according to claim 1, wherein the T in a case where the A calculated by the linear function satisfies Equation 1 is 3 years to 150 years. ### Claim 3 (depends on 1) The magnetic tape cartridge according to claim 1, wherein the magnetic tape further includes a non-magnetic layer containing a non-magnetic powder between the non-magnetic support and the magnetic layer. ### Claim 4 (depends on 1) The magnetic tape cartridge according to claim 1, wherein the magnetic tape further includes a back coating layer containing a non-magnetic powder, on a surface side of the non-magnetic support opposite to a surface side provided with the magnetic layer. ### Claim 5 (depends on 1) The magnetic tape cartridge according to claim 1, wherein the non-magnetic support is an aromatic polyester support. ### Claim 6 (depends on 5) The magnetic tape cartridge according to claim 5, wherein the aromatic polyester support is a polyethylene terephthalate support. ### Claim 7 (depends on 5) The magnetic tape cartridge according to claim 5, wherein the aromatic polyester support is a polyethylene naphthalate support. ### Claim 8 (depends on 1) The magnetic tape cartridge according to claim 1, wherein the non-magnetic support is an aromatic polyamide support. ### Claim 9 (depends on 1) The magnetic tape cartridge according to claim 1, wherein a vertical squareness ratio of the magnetic tape is 0.60 or more. ### Claim 10 (depends on 1) A magnetic recording and reproducing device comprising: the magnetic tape cartridge according to claim 1. ### Claim 11 (depends on 10) The magnetic recording and reproducing device according to claim 10, further comprising: a magnetic head having a reproducing element width of 0.8 μm or less. ### Claim 12 (depends on 10) The magnetic recording and reproducing device according to claim 10, further comprising: the magnetic tape cartridge; and a winding reel, wherein the magnetic tape is caused to run between the winding reel and a cartridge reel of the magnetic tape cartridge in a state where a tension is applied in a longitudinal direction of the magnetic tape, where a maximum value of the tension is 0.50 N or more, and the magnetic tape after running in the state where the tension is applied is wound around the cartridge reel of the magnetic tape cartridge by applying a tension of 0.40 N or less in the longitudinal direction of the magnetic tape. ### Claim 13 (depends on 10) The magnetic recording and reproducing device according to claim 10, wherein the T in a case where the A calculated by the linear function satisfies Equation 1 is 3 years to 150 years. ### Claim 14 (depends on 10) The magnetic recording and reproducing device according to claim 10, wherein the magnetic tape further includes a non-magnetic layer containing a non-magnetic powder between the non-magnetic support and the magnetic layer. ### Claim 15 (depends on 10) The magnetic recording and reproducing device according to claim 10, wherein the magnetic tape further includes a back coating layer containing a non-magnetic powder, on a surface side of the non-magnetic support opposite to a surface side provided with the magnetic layer. ### Claim 16 (depends on 10) The magnetic recording and reproducing device according to claim 10, wherein the non-magnetic support is an aromatic polyester support. ### Claim 17 (depends on 16) The magnetic recording and reproducing device according to claim 16, wherein the aromatic polyester support is a polyethylene terephthalate support. ### Claim 18 (depends on 16) The magnetic recording and reproducing device according to claim 16, wherein the aromatic polyester support is a polyethylene naphthalate support. ### Claim 19 (depends on 10) The magnetic recording and reproducing device according to claim 10, wherein the non-magnetic support is an aromatic polyamide support. ### Claim 20 (depends on 10) The magnetic recording and reproducing device according to claim 10, wherein a vertical squareness ratio of the magnetic tape is 0.60 or more.