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:
Feb. 29, 2000
Filed:
Sep. 08, 1997
David William Murphy, Lexington, KY (US);
Lexmark International, Inc., Lexington, KY (US);
Abstract
An improved non-stop, constant velocity laser printer is provided which operates in parallel to both begin printing a particular page of print media while virtually simultaneously receiving further data for that same page from a host computer. Since the communications link between the host computer and the printer is slower than the rate of consumption by the printhead provided with this printer, a certain amount of data for each page is first buffered in the printer before the print media begins to move via the printer's print engine. Since it is important for the printer to receive all of the required data for the entire page before the printhead requires that data for consumption, the printer must decide how much data of that particular page should be buffered within the printer before commanding the print engine to start moving the print media. The printer is capable of making this 'data size' to be buffered decision without any assistance from the host computer that is sending the print job to the printer-all the host need send is the standard page header information that all host computers send when transmitting a rasterized print job to a printer. The printer bases its 'data size' decision by estimating the amount of data by using the print resolution, an estimate of the compression ratio, and other information from the page header that provides a rough estimate as to how much of the area of the page of the print media is to be covered, and by estimating the communication link speed, and the amount of time that is available to perform the data transfer. Since print data is received in packets, as each packet is received, stored, and acknowledged by the printer before another packet is sent by the host, the amount of time for all of this to occur for each packet is analyzed to calculate an estimate of the approximate data transfer rate of the communications link, which is refined after receiving each new packet, but is recalculated for each new page.