Abstract: A system for cleaning documents of dust particles as the documents are moved to a print station in a terminal where an ink jet printer is used to print on the documents. A vacuum manifold is positioned upstream of the print station to clean a document of dust as the document is moved towards the printer. A cyclone dust collector is used to collect the dust particles gathered by the vacuum manifold. An air curtain system provides a curtain of air between the print head of the printer and the face of the document to be printed upon to keep any dust particles left at the print station from coming into contact with the nozzles or jets of the printer.

Abstract: A printing apparatus comprising a type carrier to travel along a print line on a printing paper, a plurality of printing hammers to be selectively driven to strike the printing paper against an inking ribbon and the inking ribbon against a platen in front of the inking ribbon, and a support member supporting the type carrier, inking ribbon and platen thereon, wherein the support member is movable between a position holding the type carrier, inking ribbon and platen in positions capable of performing printing operation but intercepting the line of sight between the print line and the operator's eyes and a position holding the type carrier, inking ribbon and platen in inoperative positions but providing an unobstructed line of sight from the operator's eyes toward the print line for enabling the operator to clearly view the printed information along the print line.

Abstract: A rotatable disc type printer for use in conjunction with a typewriter having a movable carrier. The type element or characters are carried on radially extending petals and are arranged at varying distances from the center of disc rotation so as to define a circumferential spiral path. The angular placement or position of each petal or spoke is determined by the following formula: angular placement of i.sup.th petal=360.degree./n .+-. tan .sup.-1 id/nL where n defines the total number of petals, d is the character spacing and L is the minimum distance from the center of disc to the print point. The length or distance from the center of disc rotation to the type character or element is defined by: L.sub.i (length for i.sup.th element=.sqroot.i L.sup.2 +(i/nd).sup.2 where i/nd ids the linear distance of travel of the disc center while rotating from a home position to the position for printing the character carried by the i.sup.th petal.

Abstract: A serial printer comprising a character carrier having a plurality of flexible leaf springs bearing characters on the extremities thereof. A desired character is selected by positioning the corresponding leaf spring to a printing position. A pushing mechanism exerts pressure against the leaf spring in the printing position to effect a controlled motion thereof such that the character meets the paper at a low velocity instead of from acquired kinetic energy thereby resulting in noiseless printing.