The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 21, 1998
Filed:
Jan. 20, 1995
David E Hackleman, Monmouth, OR (US);
Hewlett-Packard, Palo Alto, CA (US);
Abstract
An inkjet page-wide-array 'PWA' printer element includes memory resident on its printbar. The printbar memory offloads an otherwise excessive PWA printhead data throughput requirement enabling print speed to approach nozzle speed. Instead of transferring dot data from printer memory directly to printhead nozzle circuitry, dot data is first transferred from printer memory to printbar memory. Dot data then is transferred from printbar memory to the nozzle circuitry. Printbar memory is organized as a plurality of memory planes (i.e., 2 or more). Each plane stores dot data for one or more dot lines. For a 20 kHz nozzle speed, 600 dpi resolution, and an 11 inch printhead, dot data is transferred from printer memory to the printbar memory's first plane at a rate less than 140 MHz. Dot data then is transferred from the first plane to the second plane in one parallel transfer. For a two-plane embodiment dot data then is output from the second plane to respective nozzles to sustain printing at nozzle speed. A multiplexer data path between the second memory plane and the firing circuitry enables output of dot data for multiple nozzles at a time so that an approximately 20 MHz data rate sustains printing at the nozzle speed.