Edward A Dougherty

US Patent:

43915400, Jul 5, 1983

Filed:

Mar 31, 1981

Appl. No.:

6/249483

Inventors:

Edward C. Dougherty - Dracut MA

Assignee:

Centronics Data Computer Corporation - Hudson NH

International Classification:

B41J 3514
B41J 3516

US Classification:

400212

Abstract:

In the printer disclosed herein, shifting of a multi-color ribbon carried on a movable carriage is effected by differentially adjusting the free length of a cable extending parallel to the carriage motion. The cable passes over at least a pair of pulleys on the carriage, at least one of the pulleys being movable with respect to the other in response to changes in the free length of the cable. Solenoids are provided at each end of the cable for controllably changing the free length of the cable, the amount of change being different for the two solenoids so that four different combinations of free length are available. A ribbon shifting mechanism is coupled to the movable pulley so that the multi-color ribbon is shifted in accordance with the free length of the cable.

US Patent:

43429491, Aug 3, 1982

Filed:

Nov 9, 1979

Appl. No.:

6/093008

Inventors:

Kenneth J. Harte - Carlisle MA
Edward C. Dougherty - Dracut MA

Assignee:

Control Data Corporation - Minneapolis MN

International Classification:

H01J 2970
H01J 2974

US Classification:

315409

Abstract:

An electron beam or other charged particle beam tube of the compound fly's eye type having a coarse deflection system is described. The beam tube comprises an evacuated housing together with an electron gun or other charged particle beam producing means disposed at one end of the evacuated housing for producing a beam of electrons or other charged particles. A coarse deflector, a compound micro lens assembly, and a fine deflector are disposed in the housing in the path of the electron or other charged particle beam for first selecting a lenslet and thereafter finely deflecting an electron or other charged particle beam to a desired spot on a target plane. The electron or other charged particle beam tube is designed in a manner such that the electron or other charged particle beam is caused to diverge at a small angle of divergence in advance of passing through the coarse deflector by appropriately locating the virtual origin or point source of the charged particle a small distance in advance of the coarse deflector. In addition, a dynamic focusing correction potential is supplied to the micro lens assembly along with a high voltage energizing potential with the dynamic focusing correction potential being derived from components of both the coarse deflection potentials and the fine deflection potentials.