Abstract: A roller separating apparatus for a laser printer having a transfer backup roller, a steering roller, and a driving roller around which a photoreceptor belt circulatingly travels. The roller separating apparatus includes a first frame on which the transfer backup roller is rotatably installed. First and second eccentric cams are mounted for rotation on the first frame. A transfer roller is rotatably installed on a second frame which moves with respect to the first frame via engagement with a cam surface of the first eccentric cam. A fusing roller is rotatably installed on a third frame which moves with respect to the second frame via engagement with a cam surface of the second eccentric cam.

Abstract: An alignment device for a developing roller and a squeegee roller of an image forming apparatus. The alignment device includes a first supporting block for supporting the shaft of a first backup roller which in turn is disposed opposite to the squeegee roller with a photosensitive belt therebetween; and a second supporting block for fixing the shaft of a developing roller and enabling development by the developing roller, and for supporting the shaft of a second backup roller which in turn is disposed opposite to the developing roller with the photosensitive belt therebetween. A roller frame is provided for fixing the shaft of the squeegee roller, and for supporting the first supporting block and the second supporting block while surrounding a portion of the second supporting block. An elastic member is installed between the first and second supporting blocks for adjusting the centers of the supporting blocks.

Abstract: A thermal transfer printer capable of printing on both sides of a sheet of paper includes first and second transferring rollers, first and second guide paths, and a paper-ejection path. The paper is repositioned for printing on the reverse side, after the front is completely printed.

Abstract: A color video printer for printing onto both sides of a printing paper includes several guide rollers positioned on the circumference of a platen roller and an ink ribbon supplying unit. A thermal recording head is selectively contacted with or separated from the platen roller by the operation of a cam, and a slider is operated by the cam. In the slider, cam grooves are formed so as to operate a paper ejecting guide and a re-feed paper roller by its reciprocating motion.

Abstract: A paper holder assembly has an axle coaxially positionable to extend axially outwardly from axially opposite bases of a platen drum providing a circumferential outer surface disposed between the opposite bases, the axle has circumferential grooves terminated by corresponding flanges. A pair of brackets each having three arms joined together in a unitary monolithic structure with first and second arms defining a centrally disposed recess having spaced-apart curved sides are positioned to ride along corresponding ones of the circumferential grooves. A pivot pivotally connects the second arms to the opposite bases of the platen drum, and a paper holder extending from the distal portion of the third arm holds edges of sheets of paper against the circumferential outer surface projecting axially inwardly from distal ends of the third arms across the circumferential outer surface. Springs bias the bracket toward a first orientation relative to the pivot.

Abstract: A printer includes a device for placing the leading edge of a paper sheet at an initial printing position, and a lifting device for raising and lowering a printing head so that the printing head compresses the leading edge of the paper sheet, thereby printing without margins on the paper sheet.

Abstract: A printing method and apparatus wherein the circumference of a drum is shorter than the length of paper so that the paper is wound around the drum with the top and bottom ends of the paper overlapping by a predetermined length. Printing begins at a position spaced apart from the leading edge of the paper by the difference between the circumference of the drum and the length of the paper. An ink ribbon contains colorless portions, whose lengths are equal to the predetermined length, which is equal to the difference between the circumference of the drum length of the paper, at the borders of respective portions. Respective colors are serially printed when a printing head presses the ink ribbon. When the printing head presses the overlapping portion of bottom ends of the paper, the colorless portion of the ink ribbon passes the printing head.

Abstract: A printing method and apparatus clamps a sheet of printing paper at a first position of a drum supplied with the printing paper. The printing paper is released from a clamped state at a second position just in front of an initial printing position. While unclamped, the leading edge of the printing paper is transferred to the initial printing position, so that printing is started from the leading edge and the printing paper is again clamped at a third position which is located beyond the initial printing position. Therefore, printing is performed from the leading edge of the printing paper, which results in printing without any margins. Also, a plate spring presses the printing paper toward the drum just in front of the printing position where the print head, applies pressure for printing. The plate spring elastically applies pressure to the printing paper to transfer the printing paper to the printing position while in contact with the drum.

Abstract: A paper holder assembly has an axle coaxially positionable to extend axially outwardly from axially opposite bases of a platen drum providing a circumferential outer surface disposed between the opposite bases, the axle has circumferential grooves terminated by corresponding flanges. A pair of brackets each having three arms joined together in a unitary monolithic structure with first and second arms defining a centrally disposed recess having spaced-apart curved sides are positioned to ride along corresponding ones of the circumferential grooves. A pivot pivotally connects the second arms to the opposite bases of the platen drum, and a paper holder extending from the distal portion of the third arm holds edges of sheets of paper against the circumferential outer surface projecting axially inwardly from distal ends of the third arms across the circumferential outer surface. Springs bias the bracket toward a first orientation relative to the pivot.