Abstract: A thermal printer has a main body frame and a platen roller rotatably and removably mounted in a preselected position on the main body frame. A thermal head is mounted on the main body frame for movement into and out of pressure contact with the platen roller during a printing operation and while the platen roller is in the preselected position for recording printing data on a recording medium disposed between the thermal head and the platen roller. A detecting device detects a preselected state of the thermal printer in which the platen roller is in the preselected position and in which the recording medium is disposed between the platen roller and the thermal head.

Abstract: In order to provide a thermal printer which performs detection of the presence or absence of recording paper and detection of the attachment/detachment states of a platen roller with reliability using only one sensor and which has such a simple structure that it can be diverted to any kind system merely by changing some components, the thermal printer of the present invention comprises a main body frame, a thermal head for performing printing on recording paper and a head supporting member integrally provided at the back of the thermal head, a platen roller placed side by side with the thermal head, a bearing portion for rotatably and attachably/detachably supporting the platen roller; an urging unit for urging the thermal head in a direction in which the thermal head is brought into pressure contact with the platen roller, and a load detection type sensor provided at a position at which under a state where the recording paper exists below the platen roller and a shaft of the platen roller is supported by the

Abstract: A line printer comprises a frame having a pair of spaced-apart side walls, a platen having a shaft mounted to the side walls for pivotal movement, a print head interposed between the side walls and positioned in pressure contact with the platen, and a head-up lever mounted on one of the side walls for releasing the print head from pressure contact with the platen. The head-up lever is mounted on the shaft of the platen for pivotal movement relative thereto.

Abstract: The present invention is directed to realize a portable, compact, light, thin, inexpensive and fast printer apparatus. A motor is provided between a printing head unit and a stationary frame member to drive the printing head unit relative to the stationary frame member in leftward and rightward directions, thereby eliminating conventional indirect driving components such as a stepping motor and a lead screw. Further, a sensor is provided in the printing head unit to detect a moving velocity and a position of the printing head unit to thereby construct the printer apparatus having reduced number of components to ensure stable driving and high accuracy. According to such a construction, the motor is integrated into the printing head unit, which self-moves in the printer apparatus to eliminate a mechanism converting a rotational movement into a linear movement, thereby achieving cost down of the printing apparatus.

Abstract: The line printer is provided with a pinch roller for feeding a spring medium sheet by capstan drive. The pinch roller is pressed by an integrated pressing mechanism comprised of a spring holder, a pressing spring member disposed in the holder and a bearing piece connected to the spring member in contact with the pinch roller. A pressing lever is shiftable between a pressing position effective to apply pressing force to the integrated mechanism and a release position effective to release the integrated pressing mechanism. The released pressing mechanism or unit is moved away from the pinch roller to free the same to leave a significant gap between the pinch roller and a capstan roller, thereby facilitating removal of a jammed print medium sheet. Further, the integrated pressing mechanism facilitates maintenance performance of the line printer.