Patent ID: 7813081

Claim:
A tape cartridge, comprising: a case; a magnetic tape stored in the case; and a write protect structure for blocking information recording onto the magnetic tape, wherein the write protect structure comprises: a slidable or rotatable write protect member; and a retention member capable of retaining the write protect member in a specified position, and the retention member is capable of reversibly retaining the write protect member at least in a first position and a second position and irreversibly retaining the write protect member in a third position, wherein information recording onto the magnetic tape is blocked when the write protect member is retained by the retention member in the third position, and the write protect member is operable from the outside of the case so as to move the write protect member from the second position to the third position without disassembly of the case; wherein the write protect member comprises an engagement piece slidable in a specified range and protruding to an inside of the case, the retention member is a guide wall fixed onto the case, and the guide wall comprises: a first engagement portion for retaining the engagement piece so as to be able to retain the write protect member in the first position; a second engagement portion for retaining the engagement piece so as to be able to retain the write protect member in the second position; and a third engagement portion for retaining the engagement piece so as to be able to retain the write protect member in the third position and preventing the write protect member retained in the third position from moving toward the second engagement portion, each of the engagement portions being formed along a sliding direction of the write protect member in this order; and wherein the engagement piece has a protrusion in its top end, and the third engagement portion comprises a recess portion having a bottom face on a side of the second engagement portion.