Dung Dinh Do

US Patent:

51422964, Aug 25, 1992

Filed:

Nov 9, 1990

Appl. No.:

7/611124

Inventors:

Juan E. Lopez - Newbury Park CA
Edgar Sheh - Thousand Oaks CA
Joe Lahut - Thousand Oaks CA
Dung Do - Burbank CA

Assignee:

Dataproducts Corporation - Woodland Hills CA

International Classification:

B41J 2045

US Classification:

346 11

Abstract:

In an ink jet printer having a plurality of ink jet channels which are individually controllable to produce ink dots on a printing medium, crosstalk is reduced by activating each odd numbered channel in alternation with each even numbered channel, while offsetting the orifices of one group of channels from the other to compensate for the time difference between activations, and the voltage supplied to excite the channel transducers is varied as a function of the number of channels simultaneously exited to maintain a fixed excitation voltage across each transducer.

US Patent:

44777574, Oct 16, 1984

Filed:

Feb 21, 1983

Appl. No.:

6/477132

Inventors:

Gaston A. Palombo - Agoura CA
Dung D. Do - Burbank CA

Assignee:

Dataproducts Corporation - Woodland Hills CA

International Classification:

H02K 2904

US Classification:

318696

Abstract:

A closed loop control system for a stepper motor provides the necessary feedback to accurately control the position of a motor during acceleration, constant velocity and deceleration. Generation of commutation signals is based upon a monitoring of motor position to determine the points where commutation would result in maximum accelerating torque during acceleration and constant velocity and minimum braking torque during deceleration. These points indicate the earliest points at which commutation may occur. Commutation may be delayed in order to reduce the accelerating torque during acceleration and constant velocity or increase the braking torque during deceleration.

US Patent:

53009509, Apr 5, 1994

Filed:

Apr 30, 1992

Appl. No.:

7/876913

Inventors:

Juan E. Lopez - Newbury Park CA
Dung Do - Burbank CA

Assignee:

DataProducts Corporation - Woodland Hills CA

International Classification:

B41J 201
B41J 215

US Classification:

346 11

Abstract:

A row-interleaved printing method for use in phase change ink jet printers which minimizes appearance abnormalities when printing solid geometric shapes; minimizes the horizontal "banding-effect" caused by cross-talk between ink jets when all jets are activated; and minimize the "seaming effect" caused by paper step mechanisms when different velocity profiles are used during printing.