Tektronix, Inc.

Eldon P Hoffman

Arthur C Van Horne

Paul D Bakke

James D Rise

Edward F Burke

Ronald L Adams

Rodney B Gilbert

Charles Bradford

A printer accurately controls the passage of print media therethrough and maintains the print media taut as the print media passes through a printing zone while the media is printed by an ink jet printer. The print media sheet is preferably carried by a rotating drum in a first direction through the printing zone, with the drum being reversed to cause the exiting of the print media sheet from the printer. A pressure fixing or fusing apparatus may be positioned to flatten ink spots on the print media as the print media exits from the printer. The pressure fixing or fusing mechanism is preferably used in the case of a hot-melt or phase-change ink jet printer.

Ink jet printer architecture and method

The present invention entails an accurate, sensitive, and stable means of mounting a print head to a movable carriage assembly of the type used in computer output printers. The invention uses one pair of planar mounting surfaces and one pair of angled mounting surfaces between the print head and the carriage of a print head assembly. A pair of pivoting clamping plates apply a force that urges both pairs of mounting surfaces together while simultaneously providing adjustment of the translation of the print head relative to the carriage. The translation across the oppositely angled surfaces on two of the four mounting surfaces provides an accurate azimuthal angle adjustment for the print head. Because the other mounting surfaces are in the same plane, the translation affects only the azimuthal angle.

Rotational adjustment of an ink jet head

A print medium sheet feeding system for an ink jet printer having a print head with a planar array of jets is provided by clamping the leading edge of a paper after it is passed through a printing zone to a rotating assembly of parallel disks. The sheet is pulled through the printing zone by rotating the disk with the clamp being carried with the rotating drum. A platen may be provided which has a flat surface in the printing zone forming a tangent to the outer surface of the rotating disks. Alternatively, the platen may be removed and the sheet held in tension between the clamp and a nip region formed by a spring plate held against a restraining plate. In an alternative embodiment, the sheet is initially clamped against the drum by the combination of a lever arm which is selectively engagable with the drum for rotation therewith and an attached actuating arm having a plate which secures a sheet to the drum surface. The resulting clamp rotates with the drum until the sheet passes below idler rollers which are biased against the drum surface. These rollers then hold the sheet against the drum for motion of the sheet with the drum surface. The actuating arm is released from the drum after a sheet passes below the rollers, thereby allowing any sized sheet to be fed through the system.

Printer sheet feed apparatus with single driver

A print medium sheet feeding system for an ink jet printer having a print head with a planar array of jets is provided by clamping the leading edge of a paper after it is passed through a printing zone to a rotating assembly of parallel disks. The sheet is pulled through the printing zone by rotating the disk with the clamp being carried with the rotating drum. A platen may be provided which has a flat surface in the printing zone forming a tangent to the outer surface of the rotating disks. Alternatively, the platen may be removed and the sheet held in tension between the clamp and a nip region formed by a spring plate held against a restraining plate. In an alternative embodiment, the sheet is initially clamped against the drum by the combination of a lever arm which is selectively engageable with the drum for rotation therewith and an attached actuating arm having a plate which secures a sheet to the drum surface. The resulting clamp rotates with the drum until the sheet passes below idler rollers which are biased against the drum surface. These rollers then hold the sheet against the drum for motion of the sheet with the drum surface. The actuating arm is released from the drum after a sheet passes below the rollers, thereby allowing any sized sheet to be fed through the system.

Printer sheet feed system

In accordance with the present invention, a drum (10) has a central shaft (11) which is rotatably mounted to a drum supporting frame (12). A mount (26) pivotally connects one side (30) of the frame (12) to a cabinet (14) for pivoting about a frame pivot (73). A mount (15) rigidly secures the other frame side (32) to the base (14). An isolation mounting bracket (86) supports an optical encoder (84) in position to monitor the velocity of the shaft (11). Bracket (86) has pivots (98, 100) which cooperate with the frame pivot (73) to provide in effect a parallelogram support structure for the optical encoder (84). Thus, the encoder (84) may translate, but not rotate, in response to vibrations of the frame (12) so as to minimize or eliminate erroneous encoder velocity readings otherwise arising from such vibrations.

Growing community of inventors

West Linn, OR, United States of America

Eldon P Hoffman