Tape cartridge having rotation detection unit for drive roll

摘要

A tape cartridge (1) employed for data backup for a personal computer or an office computer, known as a data cartridge, in which the state of rotation of a drive roll (13) can be detected by means of an rpm detecting section (34) provided on the drive roll in order to control the driving device with a view to reducing data error and preventing loss of storage capacity. As for constitution, a cover member (3) and a base plate (4) are combined to make up a main cartridge member (2) within which a pair of tape reels (8, 9) are accommodated. A magnetic tape (7) placed around the tape reels (8, 9) is run by a drive roll (13) the outer periphery of which is partially exposed via an opening (21) formed in the front surface of the cover member (3). A capstan roll (46) of a driving device (40) is in surface contact with the driving roll (13) for transmitting its rotation to the drive roll. A rpm detecting section (34) provided on the drive roll (13) is detected by a detection section (35) provided on the cover member (3) for controlling and correcting any loss in rotation transmission caused by slip between the drive roll (13) and the capstan roll (46) by the driving device (40). <MATH>