Hewlett-packard Company

Corrina A Hall

W Wistar Rhoads

Arthur King Wilson

Lance B Cleveland

William James Allen

Ronald Albert Askeland

David W Swanson

Mark S Hickman

Keshava A Prasad

Damon W Broder

William H Schwiebert

Mindy A Hamlin

James G Salter

Robert R Beeson

Shelley I Moore

Patricia S Brown

William C Hilliard

Jeffrey A Thoman

Catherine B Hunt

Precise alignment between two or more nozzle plates affixed to print cartridges installed in a single carriage of an ink printer is achieved by machining datum projections on each print cartridge after its nozzle plate has been permanently secured to the print cartridge. The machined datum projections on the print cartridge contact surfaces on the carriage when the print cartridge is installed in the carriage such that the dimensions of the datums affect the position of the cartridge, and hence the nozzle plate, within the carriage.

Alignment of multiple nozzle members in a printer

An apparatus and method for providing proper electrical contact between corresponding interconnect pads of a print cartridge and a print carriage are disclosed. One end of a flex circuit having interconnect pads of the print carriage is attached to one side of the print carriage while the other end of the flex circuit may be substantially free or attached to an opposing side of the print carriage. When the print cartridge is initially inserted into the print carriage, a gimbal spring causes the flex circuit interconnect pads to preliminarily come in contact with the print cartridge interconnect pads before the print cartridge is completely inserted. As the print cartridge is further inserted, the print cartridge pushes out any excess slack in the flex circuit while providing a wiping action between the interconnect pads of the print cartridge and the flex circuit. This wiping action between the interconnect pads scrapes away any contaminants and corrosion, thus ensuring reliable electrical contact.

Wiping structure for cleaning electrical contacts for a printer and ink

Images are printed using marks formed in pixel arrays by a scanning print head. For transparent and glossy media, with poor absorbance, drying is enhanced by a multipass (preferably six-pass) print mode in which the total number of ink drops or spots is allocated among correspondingly multiple masks, though some may be duplicates. To further hasten drying, heat is applied--through the medium, from the opposite side as that on which ink is deposited--but the amount of heat is strictly moderated, particularly for nontransparent glossy media, to accommodate the hypersensitivity of these media to heat-induced warping. Heating for glossy media is preferably restricted to about one-third the power used for drying plain paper. Convective drying too is promoted, by operating a fan over the printed image. Certain special techniques well-suited for plain-paper printing have been found undesirable for use with plastic media; these techniques include so-called 'resolution-enhanced technology', bidirectional printing (particularly of black), and optical-density controlled printing speed. At top and bottom of each page or sheet of printing medium, where it is undesirable to operate with the pen partly off the edge of the sheet, and where also the printing medium is constrained from only one direction rather than being held taut beneath the pen, the print mask is rotated while the printing medium is held stationary--thereby entirely avoiding reliance upon accuracy of print-medium advance.

Inkjet printing: mask-rotation-only at page extremes; multipass modes

An improved modular carriage assembly for an inkjet printer including: a carriage with at least two stalls molded therein for holding a plurality of inkjet pens; and a removable frame insertable in a compartment in the carriage adjacent to the stall for holding an electrical circuit. In a specific embodiment the improved modular carriage assembly includes at least two extensions molded onto the removable frame. When the removable frame is inserted into the compartment each of the extensions is inserted into a respective stall. A method of assembling a carriage assembly for an inkjet printer with inkjet pens includes the steps of: attaching an electrical circuit to a frame; positioning a unitary clamp on a carriage; and installing the frame with attached electrical circuit to the carriage. Installing the frame on the carriage holds the unitary clamp in place on the carriage. Another specific method of assembling a carriage assembly includes the steps of: removably attaching a circuit to the frame; removably attaching an interconnect device to the circuit; and wrapping the interconnect device over the frame for interconnecting the circuit to inkjet pens. The improved modular carriage assembly has reduced cost and is easier to assemble, align and service without the need for any special tools.

Modular carriage assembly for an inkjet printer

A method and apparatus for heating the print medium in a ink-jet printer to reduce printing defects in a relatively cold machine. The printer includes a print area heater which in a steady state condition for a given print medium is energized at a first heating level. Under cold start conditions, for an initial plot, the hater is overdriven at a second heating level. Under a multiple-pass printing mode, the hating drive is gradually reduced during an initial portion of the initial plot, until the first heating level is achieved. The heater drive level remains at the first heating level for subsequent plots in a given batch. For single-pass print modes, the heater drive level remains at the second level for the entire initial plot in a batch, and is reduced to the first level for subsequent plots. The printer has a preheater along the medium path, with an unheated area along the path between the print area and the preheater. To further improve print quality when printing along top leading edge margins, the paper is initially advanced until the leading edge is over the print area heater and left for a first time interval. The paper is then retracted to position the paper area initially located over the unheated area of the paper path during the first interval over the preheater. The paper is left in the retracted position during a second time interval, and then advanced to the print area to commence printing operations.

Method and apparatus for heating print medium in an ink-jet printer

At least one certain primary or secondary color is established that receives special treatment for at least one printing medium. Such treatment may include (1) using more than two drops of primaries per pixel for binary printing of a particular secondary; or (2) binary-printing the chromatic primary or secondary--but not other hues--after rendition, by use of a 'superpixel'; or (3) application of, in effect, a nonintegral number, greater than one, of ink drops per pixel; or (4) combinations of these treatments. As an example of the first of these treatments--using inks optimized for plain paper at one drop of ink for primaries and two (one of each of two primaries) for secondaries--red is printed on transparency film as one drop of yellow ink and two of magenta in each pixel. As to the second treatment, the superpixel is preferably a group of pixels (e.g., a two-by-two array) including the target pixel, in which group each pixel is inked and at least one pixel receives at least two drops of ink.

Inking for color-inkjet printers, using non-integral drop averages,

Growing community of inventors

Escondido, CA, United States of America

Corrina A Hall