Abstract: An image processing apparatus (10) includes an imaging drum (300). A printhead (500) moves along a line parallel to the longitudinal axis (301) of the imaging drum as the imaging drum rotates. A linear drive motor (258) turns a lead screw (250) and is mounted directly onto the shaft of the lead screw. The motor is constrained from rotation by means of a rotational stop (296) that is magnetically held. A similar means is used to constrain a drum encoder (344).

Abstract: Two carriage drive systems are arranged to be selectively coupled to a uniform stepping mechanism responsive to spacing signals whereby a carriage can be indexed across a writing line at 10 or 12 pitch increments.

Abstract: An impact printer is provided which is capable of printing at either 10 characters per inch (standard pitch) or 15 characters per inch (compressed pitch) by changing the type character carrying member, such type carring member including multiple font character sets thereon. The type character carrying members or bands include timing marks thereon for detecting or sensing the type band (standard or compressed pitch), the type character font set, and for tracking the type characters on the band. The printer also includes time shared hammer means which are movable or shifted a precise distance of 1/10 inch for a standard pitch band or a precise distance of 1/15 inch for a compressed pitch band, such movement being operable by control mechanism responsive to pulses derived from the timing marks relative to the horizontal position mechanism and the type band on the printer (standard or compressed pitch).

Abstract: In a serial printer a movable type character element such as a ball, disc or the like is rotated to present different type characters to the print position. The carrier for the type element is moved along the print line at a predetermined maximum velocity so long as it is possible to move the type element to the next character in time required to move the carrier from one print position to the next. If the type character set-up time is greater, the carrier is run at a slower speed and is then returned to the predetermined velocity for printing.