Abstract: A printer which utilizes a charge controlled ink jet head is disclosed. A platen and its surrounding parts will be marred if the ink jet head is operated when there is no paper around the platen. Thus, the detection of a paper is of importance, and accordingly, a paper sensor is disposed near the platen. To prevent the sensor from being contaminated by the ink, the paper sensor is disposed rearward of the platen, as viewed from the ink jet head. The presence or absence of a record paper in front of the ink jet head is determined by a microprocessor which responds to a detection signal from the paper sensor and the amount of rotation which the platen has undergone since the detection of a paper by the sensor. If the printing operation is in pause over a given time interval at the end thereof or after the initiation of the projection of an ink jet, the projection of the ink jet is interrupted in order to reduce evaporation of solvent from the ink.

Abstract: An apparatus for driving a floppy disc includes a first sensor responsive to a magnetic disc encased in a jacket of the floppy disc. Before the magnetic disc is gripper in a predetermined position, a d.c. motor included in a disc rotating mechanism is started in order to prevent rush current therethrough. After the start of the d.c. motor, a second sensor senses a return of the magnetic disc to a predetermined regular position whereupon a cone load drive source is activated to automatically move a cone toward a drive hub. Thus, the magnetic disc can be gripped and set in the regular position merely by inserting it into the apparatus. The apparatus also includes ejection apparatus for ejecting the floppy disc.