Abstract: A printer includes a print mechanism for performing printing operations and a print medium feeding mechanism for feeding a print medium past the print mechanism so that printing operations can be performed on the print medium. The print medium feeding mechanism includes a forward feed apparatus located downstream of the print mechanism for feeding the print medium in the forward direction past the print mechanism and a print medium tensioning apparatus. The tensioning apparatus includes at least one pair of pressure wheels rotatably mounted on the frame and located on opposite sides of a print medium being fed by the forward feed apparatus and means for restricting the rotation of at least one of the pressure wheels, whereby the pressure wheels exert a retarding force on the print medium tending to tension the print medium. Each pressure wheel is constructed so that it is flexible in the axial direction so as to permit lateral movement of a print medium as it passes between the pair of pressure wheels.

Abstract: Where the ribbon advance mechanism of a printer is driven by the motion of the print head carrier, ink in the ribbon will be differentially depleted depending upon the density of print. This varied depletion becomes a problem for printers capable of printing high density graphics images, particularly color filled images. In accordance with this invention, the printing density is monitored and when the printing density exceeds a predetermined value, the print head is caused to be moved an amount greater than that necessary to position the print head at a succeeding print position so as to thereby cause additional ink ribbon to be advanced and to avoid overprinting on areas of the ribbon where high density printing has occurred.

Abstract: A printer includes a print mechanism defining a print region and a removable ink ribbon cartridge. The cartridge includes a body and two arms which are spaced apart and pivotally attached to the body with an ink ribbon across the gap between the ends of the arms in the print region. The printer includes an arm moving mechanism for moving the arms about their pivots on the body of the cartridge so that the portion of the ribbon in the print region can be moved laterally.One of the arms is formed with a first indicator which cooperates with a sensing system on the printer to indicate the lateral position of the ribbon in the print region. The sensing system can also determine whether the cartridge is installed correctly in the printer. A second indicator is located on the arm and the sensing system can detect the position of this second indicator to indicate the type of ribbon in the cartridge.