International Business Machines Corporation

Charles O Ross

Louis V Galetto

Donald Frederick Jensen

Vincent M Lisica

Arnold B Rosenthal

Apparatus for recording a displayed frame of video data by storing the binary data bits from identical segments of each video scan line, thereafter supplying the stored bits of the segments to a traversing matrix print head for recording the bits in those segments, and repeating the process with data bits from a different series of scan line segments. The number of data bits comprising a segment usually corresponds to the number of recording elements in the print head, and the number of print head excursions will vary inversely to the number of data bits in each segment. A resulting recorded video frame thus appears rotated 90.degree. with respect to the original frame orientation.

Apparatus for recording displayed video data

Circuit for selectively enabling energization of printing electrodes in sequence in a print head to achieve a more nearly constant current flow in the electrodes to thereby produce recorded marks of more uniform size. The formation of the electrodes into gated small groups reduces the maximum allowable current and, hence, the electromagnetic radiation. During traversal of the print head along a print line, a lagging electrode group or groups are enabled before the leading groups regardless of travel direction to minimize recording impedance for energized electrodes.

Print electrode control circuit

The carrier for the print head of a printer which is to be used at different operating speeds as a display printer, as a read-only printer, or as a keyboard display printer with asynchronous character rates over a wide range, is operated by a servo motor under the control of a digital/analog converter which continually sums the outputs of an up/down counter which is incremented by incoming data and decremented by the output of a shift register advanced by the incoming data.

Variable print speed control

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.

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Endicott, NY, United States of America

Charles O Ross