Abstract: A print head position control system for a printer in which a print head moves along a track and in which a light source illuminates along the track and a photodetector receives the light to produce a control signal in proportion to the position of the print head in relation to the light. A print head mount electromechanically adjusts the position of the print head in response to the control signal, so that the path of the light automatically controls the print head path along the track.

Abstract: A print head assembly includes the feature of snap-in, tool-less replaceability. The print head is intended for an application where extended use is expected and replacement, due to wear, will be necessary by nontechnical users of the printing system. In one embodiment, the print head utilizes two pins which slide into slots formed in the printer body. The print head is free to pivot about the two pins and is urged against a platen by the force of bias springs and a loaded pin. The loaded pin engages with, and forces upwrd on the heat-radiating fins extending from the bottom of the print head. Shelves formed in the printer body cover engage the two pins of the print head and force the print head, against the forces of the bias springs, into a proper alignment position when the cover is closed. This allows firm engagement of the print head with the platen, and proper alignment thereof, without fixing the print head to a mounting structure.

Abstract: A copier capable of producing simplex and duplex copies includes a tri-roll inverter that employs a corrugating roll on roll return force applicator located downstream from the tri-roll input/output members. A sheet coming into the inverter is driven by a pair of the tri-rolls into a nip formed between corrugating rings mounted on the dual rolls of the return force applicator. One of the rolls has a minimal friction force and rotates continuously in the opposite direction to the incoming sheet. When the last portion of the sheet is driven into the corrugation nip, the friction force of the nip will cause the sheet to buckle into an output nip of the tri-roll members for outward movement.

Abstract: A copy quality sensor for a reproduction machine of the type having a photoconductive member on which latent images of the original being copied are electrostatically formed and thereafter developed. The developed latent images are then transferred to copy sheets which may be then fused to provide a permanent image.The aforesaid transfer of images from the photoconductive member to the copy sheets is effected by a transfer apparatus which includes a transfer roller. A portion of the photoconductive member and transfer roller are reserved for receipt of a test image, which is developed normally on the photoconductive member in addition to the image of the original. The developed test image is transferred directly to the surface of the transfer roller rather than to the copy sheet. A light source is arranged to impinge a beam against the transfer roller opposite the point on which the test image appears, and a photoelectric type pick-up is positioned to receive the beam reflected off of the transfer roller.