Abstract: An apparatus such as a printer or a plotter feeds image-receiving media such as paper by rotation of a shaft, and a media position sensor responds to the rotation of a sensor roller. The apparatus includes a position sensor calibration device having an elastically deformable ring compressible between the shaft and the sensor roller and a calibrator for changing the distance between the shaft and the sensor roller so as to change the amount by which the deformable ring is compressed, in order to adjust the output of the media position sensor for a given amount of media movement. The shaft is connected to one of a pair of media-gripping pinch rollers, the one pinch roller being rotatable by the shaft, and a shaft motor is connected to the shaft. The ring is pinched between the shaft and the sensor roller. The calibrator is a screw threaded through a stationary threaded support and extending toward the sensor roller to push the roller toward the shaft and compress the elastically deformable ring.

Abstract: In a thermal printer for thermally printing on a wide media with a composite printhead comprising a plurality of standard thermal printheads and including a small diameter print roller for supporting the media adjacent the printhead, an improvement to improve print quality by preventing bowing of the print roller away from the printhead. In one embodiment, there is a first cylindrical support roller mounted parallel to the print roller in rolling contact therewith along the length thereof to oppose vertical movement or deformation of the print roller.

Abstract: An apparatus which records an image, such as text, onto printable media, such as paper, has a removably closable lid, a paper cutting blade mounted on an pivoting arm having an equilibrium position in which the blade is withdrawn in a safe position, and a rod actuator cooperative with the lid for rotating the pivoting arm whenever the lid is closed so as to move the blade from the safe position to an operative position adjacent a cutting block suitable for severing the media. The pivoting arm is rotatable about a pivot pin, the blade being attached at one end of the arm and the other end of the arm being lighter, so that the blade tends to fall toward the safe position under a front cover of the apparatus whenever the lid is opened.