Abstract: The invention provides an apparatus capable of automatically changing over continuous paper and cut paper, wherein manual changeover is possible even if an actuator is locked in case of an accidental paper jam, to thus facilitate a processing. A platen gear can be associated with a tractor drive gear via a clutch gear for connecting or disconnecting both gears to or from each other upon oscillation of a clutch lever. The clutch lever is oscillated by a changeover lever which is moved by a changeover cam driven by a stepping motor. Therefor, the changeover cam is manually moved under a normal condition so that the changeover of the continuous paper and the cut paper can be manually performed without any application of a load of the stepping motor.

Abstract: In dot impact printers, a platen or a print head may be thermally expanded or contracted due to heat generated from a driver of a print head, with the result that a gap between the print head and a sheet of print paper on the platent varies. In order to maintain a proper gap therebetween regardless of the thermal deformation of the platen and/or print head, a temperature sensor is provided for sensing the temperature of the platen or the print head, and the gap therebetween is adjusted based on the sensed temperature. This adjustment is performed each time when a number of printed characters have reached a predetermined number.

Abstract: A printer comprises a platen roller for supporting and feeding a cut sheet, a first motor for rotating the platen roller and a tractor for feeding a continuous paper. The tractor is capable of being connected to the first motor through the platen roller. The printer comprises a second motor having first, second and third phases based on a rotational angle. A clutch can be connected to both the platen roller and the tractor and can be disconnected between the platen roller and the tractor based on driving force from the second motor. A paper bail roller is faced with the platen and the platen bail roller can be moved between a position contacting the platen and a position separated from the platen by paper bail roller moving unit based on driving force by the second motor.

Abstract: In a printing device having at least a pair of sheet discharge rollers for discharging a printing sheet on which a printing operation has been executed, provided are means for judging whether the printing sheet exists or not at a contact position of the pair of sheet discharge rollers, and control means for controlling the pair of rollers so as to be brought out of contact in case that the sheet does not exist at the contact position. Thus, even if the sheet is skewed or bent, it is securely nipped between the pair of sheet discharge rollers, thereby reducing occurrence of a sheet jamming.

Abstract: For dot impact printers having a platen which may be installed such that the geometric central axis thereof is displaced off a rotation axis about which the platen rotates, a carriage on which a print head is mounted is moved toward the platen from a predetermined position until the distal end portion of the carriage is brought in abutment with the circumference of the platen to thereby measure the surface level of the platen. This measurement is repeatedly carried out while angularly rotating the platen. The thus measured surface levels of the platen are averaged, and based on the average data an optimum position of the print head to be located apart from the sheet of print paper supported on the platen is determined.

Abstract: A read/write head which is usually used for reading out and writing information from and into the surface of the disc and the servo information recorded on the disc as a position sensor. Servo information to be recorded on a surface of a disc to detect the deviation of the head from a normal position of each track is formed by a plurality of servo information portions and the servo information regarding to a reference track is made different from the servo information of other tracks. A plurality of numerical values indicative of the servo information portions are detected from the signal read out by the head. In accordance with the detected values, the reference track is designated.

Abstract: A printer having a device for advancing and retracting a print head toward and away from a paper supporting platen, an automatic head gap adjusting device for controlling the head advancing and retracting device, to advance the print head until the print head comes into contact with a recording paper, and then retracting the print head by a predetermined distance, to thereby adjust a head gap between the paper and the print head, and an operator-controlled head gap adjusting device for manually operating said head advancing and retracting device, to thereby adjust the head gap. A mode selector is provided for selecting one of an automatic adjusting mode in which the head gap is adjusted by the automatic head gap adjusting device, and a manual adjusting mode in which the head gap is adjusted by the operator-controlled head gap adjusting device.