Method for avoiding print buffer underrun
View Patent ↗In order to avoid print buffer under-run a printing method involves a printer printing a rendered first page of print data while another page is rendered in a connected computer. Simultaneously, a previously rendered page of print data is transmitted from the computer to the printer. Typically the connection between the computer and the printer is a relatively low bandwidth connection such as a USB, parallel port or 10 Base-T Ethernet connection. In order to rapidly transmit the rendered pages of print data across the low bandwidth connection the computer applies data compression to the print data.
1. A method for printing multiple pages including the steps of:
rendering a first page of layout data with a computational device to produce a rendered first page;
transmitting the rendered first page to a printer whilst rendering a second page of layout data with the computational device to produce a rendered second page; and
upon the printer receiving the rendered first page, printing the rendered first page with the printer whilst rendering a third page of layout data with the computational device and transmitting the rendered second page to the printer,
wherein each said page of layout data includes continuous tone portions and bi-level portions.
2. A method according to claim 1 , wherein the computational device communicates with the printer by means of one or more of the following: a universal serial bus (USB); a parallel port; a 10 Base-T Ethernet connection.
3. A method according to claim 2 , wherein rendering with the computational device produces each of said rendered pages in a compressed format.
4. A method according to claim 1 , including rendering the continuous tone portions of each page of layout data with JPEG compression.
5. A method according to claim 1 , including rendering the bi-level portions of each page of layout data with an edge-delta runlength (EDRL) compression scheme.
6. A method according to claim 1 , including storing a rendered page being transmitted from the computational device in a first buffer of the printer and storing a page being printed in a second buffer of the printer.