Raster Graphics Inc.

Data Products Corporation

Ulvac, Inc.

David Albertalli

Peter H Wolf

Scott R Bruner

Oleg N Gratchev

Boyd E Slade

Perry West

Dan C Mower

Howard Walter Bielich

Cliff Gyotoku

Noel Schmidt

Donald R Billet

Robert G Boehm, Jr

Larry Capps

Gus Andriancen

Jim Middleton

Peter Fellingham

Gus A Adriancen

Paul Gregory

Sasan Saadat

Daniel Sramek

Scott D Slade

James A Middleton

George Fellingham

The present invention is generally directed to providing drop volume normalization of the ink jet nozzles in an ink jet printing operation to alleviate and/or eliminate banding effects due to imprecise placement of ink drops on the printed sheet and variations in the volume of drops produced by different ink jet nozzles of the print device. Exemplary embodiments relate to a method and apparatus for controlling a print device having at least one ink jet nozzle by adjusting an offset control of a power supply used to control drop volume of the at least one ink jet nozzle. In a print device configured with piezoelectric ink jet nozzles, the output drop volume of the nozzle can be controlled within a predetermined range by adjusting the voltage supplied to the ink jet nozzle. As those skilled in the art will appreciate, this offset control of drop volume will result in a change to output ink velocity as well. Accordingly, exemplary embodiments of the present invention further compensate a firing time of the at least one ink jet nozzle as a function of the offset control to account for a change in output ink velocity of the at least one ink jet nozzle.

Method and apparatus for drop volume normalization in an ink jet

An ink supply apparatus includes a carriage on which a printer head arrangement including a printer head is mounted to an alignment plate and an ink reservoir arrangement including an ink reservoir is mounted to a frame pivotably connected to the alignment plate to permit access to the printer head arrangement. A conduit connects an inlet of the printer head to an outlet of the ink reservoir. The outlet of the ink reservoir is located directly behind the inlet of the printer head when the frame is pivoted to a normal operating position to minimize surges in the conduit and thereby prevent leakage out of or air ingestion into the nozzles of the printer head. The ink supply apparatus is particularly well suited for use in ink jet printers where multiple printer heads are used and printing occurs in two directions of travel of the carriage.

Ink supply apparatus

In a method for reinforcing a flexible sheet such that the flexible sheet will retain desired topographical features, a flexible sheet is positioned on a surface of a magnetic chuck. The surface of the magnetic chuck has a topography, such as a perfectly flat topography, such that a magnetic force of the magnetic chuck causes a first surface of the flexible sheet to be formed into a reverse topography of the topography of the magnetic chuck. A frame having greater rigidity than the flexible sheet is secured relative to the flexible sheet as the first surface of the flexible sheet is formed into the reverse topography of the topography of the magnetic chuck by the magnetic force of the magnetic chuck. The flexible sheet together with the frame secured thereto are removed from the magnetic chuck. The first surface of the flexible sheet retains the reverse topography of the topography of the magnetic chuck when the flexible sheet is removed from the magnetic chuck together with the frame secured thereto.

Method for reinforcing a flexible sheet

In an apparatus for intermittently advancing a web, only one surface of the web contacts moving parts of the apparatus. The apparatus includes, in a direction of movement of the web, a device for supplying the web, a first dancer roller arrangement, an intermittently driven drive roller, a second dancer roller arrangement, and a take-up device. The first and second dancer roller arrangements function to isolate a portion of the web from inertia in other portions of the web, and to provide substantially constant tension on opposite sides of the drive roller to prevent slippage and ensure accurate intermittent advancement of the web by the drive roller. A method for intermittently advancing a web is also disclosed.

Apparatus and method for advancing a web

Printer heads are precision mounted relative to a plate on a printer carriage by assembling a plurality of identical printer head assemblies, each of the printer head assemblies including a printer head precision mounted to a printer head carrier, each of the printer head carriers having at least three alignment points. Openings are provided in a plate in precise locations corresponding to desired locations and orientations of the printer head assemblies on the plate. The openings each have at least three alignment points corresponding to the three alignment points on each of the printer head carriers. The printer head assemblies are positioned in corresponding ones of the openings and a force is applied against the printer head assemblies, such as by springs mounted on the plate, to cause the at least three alignment points on the printer head carriers to contact respective ones of the at least three alignment points in the corresponding ones of the openings. A printer head carriage having printer heads precision mounted to a plate is also disclosed.

Printer head carriage and method for aligning printer heads on a printer

A system for printing dot-matrix characters wherein a double column of dot forming elements is used, and no single dot forming element is required to print more often than once in any four column interval of printed text. Means for timing the actuation of the dot forming elements wherein the 'on' time of the individual actuators can be longer than the time interval between columns is included.

Control system for matrix print head

Growing community of inventors

San Jose, CA, United States of America

David Albertalli