To avoid damage to a web conveyance mechanism by promptly ensuring a stable amount of air loop slacking of a web without significant changes in an air loop mechanism in case that an external paper feeding device is suddenly stopped even when the web is conveyed at a high speed.
A web carrying device includes a second control means (CPU28A, air loop stable state determination control section 33) for calculating a period of time from a start of printing to when signals output from first-fourth sensors 13a-13d of an air loop detection portion 13 are switched from on to off, or from off to on, and an web take-in average speed such that web take-in speed accumulated information 35 is divided by a number of accumulation times during the signal switching of the air loop detection portion 13, then calculating a fluctuation cycle of an amount of slacking in an air loop from the transition of the average speed, and reaching a determination that the air loop is in a stable state when a fluctuation in the amount of slacking in the air loop during web conveyance falls within the predetermined range stored in a memory device 29A.
MIZUNO MASAHIRO
| JP2006327734A | 2006-12-07 | |||
| JPH0494351U | 1992-08-17 | |||
| JP2004292133A | 2004-10-21 |
Toru Kabayama
Shuichi Kudo
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