Hewlett-packard Company

Hewlett-packard Development Company, L.P.

William C Hilliard

Kirt Alan Winter

Yoav Epstein

Damon W Broder

Robert R Giles

Gerold G Firl

Lance B Cleveland

Corrina A Hall

Joseph P Milkovits

Gregory D Raskin

Aneesa R Scandalis

A digital still camera is used for taking and storing digital representations of a plurality of images. A printer, such as an ink jet printer or a laser printer, is used for generating graphical representations of selected ones of the plurality of images on a preselected print media such as a paper. A flash memory card, floppy diskette, direct data link or some other data transfer scheme is used to transfer the digital representations of the plurality of images from the digital still camera to the printer. The printer includes programming for generating a combination proof sheet and order form. The combination proof sheet and order form can include an array of thumbnail images and a plurality of image selection and/or image enhancement user designation areas such as bubbles to be filled in by the user with a pencil. The printer includes a scanner and related circuitry and software for scanning the combination proof sheet and order form to detect the user designation areas completed by the user. The programming in the printer thereafter causes it to generate at least one final print sheet with the images and enhancements designated by the user on the combination proof sheet and order form. The proof sheet and order form can be used to designate the number of final prints of a selected image, the size and/or cropping of the prints, the brightness, color balance, background, borders and so forth.

System and method for printing and scanning a user-completed digital still camera image proof sheet and order form

Two printing-medium guide systems restrain the medium. One is in an area upstream (along the direction of medium advance) from the pen, and extending laterally across the width of the medium except in one or more regions laterally near the engagement of a print-medium advancing device. The other guide system is disposed laterally from the pen, and extends laterally across the medium only in one or more regions laterally near the engagement of the advancing device. Preferably these 'one or more regions' are only near the lateral edges of the medium--so that (1) the first guide system restrains the medium over an area that stops short (ideally about 11/2 centimeter short) of the lateral edges; and (2) the second guide system is bifurcated, disposed laterally in two directions from the pen, and restrains the medium across only the lateral edges of the medium (most preferably in a strip whose width is a few millimeters, ideally 3 mm). Preferably a human-actuable control selects a print-medium width, and shifts at least one bifurcation of the second guide system. A tensioning system, longitudinally beyond the marking head from the medium advancing device, and generally aligned laterally with that device, tensions the medium away from the advancing device to hold the medium taut at the pen. Preferably the advancing and tensioning devices are very closely spaced upstream and downstream, respectively, from the pen zone. When tensioned, the medium moves a normal distance through the apparatus at each operation of the advancing device; but after a trailing edge of the medium passes the advancing device (so that the medium is advanced only by the tensioner and no longer tensioned), the advance distance is decreased (preferably by about half).

Combined central and lateral hold-down plates, and end-of-page

In bidirectional printing, ink-drop time-of-flight effects undesirably operate in opposite senses, during operation in the two different printing directions respectively, to offset the actually printed ink position in opposite directions from any nominal ink-firing point. When a common firing point is used for marks that should be aligned, during bidirectional scanning, the two resulting sets of image features are misaligned. To compensate for this adverse phenomenon, the firing points, in the two directions respectively, are made to bracket each common, desired mark location; the bidirectionally flying drops thus 'lead' or approach each desired common mark location from opposite directions and can be made to align precisely. This can be done by addressing each position based on an earlier-arriving encoder-signal pulse and passing the signal through a delay line--during pen movement in just one of the two directions. A related approach is to use a subpixel spacing feature generally provided in the pen-positioning system, to back the firing position off in for example units of about 1/24 millimeter (1/600 inch)--but during scanning in only one of two directions--to roughly align the marks. The asymmetrical earlier-pulse selection (or 'backing off') and delay improve alignment. Another technique is useful for certain situations in which the printer uses large amounts of ink--relative to the amount of liquid that can be absorbed by or evaporated from the printing medium that is in use--for example, when doing double-ink-drop printing on transparency stock. An unesthetic mottling effect arises in such situations. It has been discovered that, in this case, print quality is improved by purposely choosing relatively large jitter or random variation in firing time in each pixel column.

Position leading, delay and timing uncertainty to improve position &

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

Growing community of inventors

San Diego, CA, United States of America

William C Hilliard