| 摘要 |
PROBLEM TO BE SOLVED: To surely prevent economic loss due to theft of a sheet of high economic value, while improving usability in an image forming apparatus replacedly using a normal printing sheet and the sheet of high economic value in the same sheet cassette.SOLUTION: The detachable sheet cassette 1 is disposed in an apparatus body 10. As a locking means for locking in an attached state, a solenoid 4 is disposed in the apparatus body side. A blanket 5 is disposed on the sheet cassette 1 side. When a preset sheet size coincides with a sheet size detected by a sheet size detection means when setting a sheet, a lock control means controls to lock the sheet cassette 1 by the lock means. |
