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Printer Performance Improvement

IP.com Disclosure Number: IPCOM000051052D
Original Publication Date: 1982-Aug-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 2 page(s) / 14K

Publishing Venue

IBM

Related People

Elliott, WB: AUTHOR [+5]

Abstract

The following description illustrates a new approach to improving the throughput rate of a printer. Usually, the controller insures a previous task is properly terminated before initiating the following one. This is to permit error recovery and fault-free restarts when a malfunction occurs during a task. This approach, however, reduces throughput because of the time periods between the completion of one task and the beginning of the next.

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Printer Performance Improvement

The following description illustrates a new approach to improving the throughput rate of a printer. Usually, the controller insures a previous task is properly terminated before initiating the following one. This is to permit error recovery and fault-free restarts when a malfunction occurs during a task. This approach, however, reduces throughput because of the time periods between the completion of one task and the beginning of the next.

For example, the Flowchart A illustrates a simple sequential process, performing one step at a time. It has the advantage that error recovery at any point is simple because each step must be completed before the next is initiated' Other advantages are that it is easier to program and requires less control memory space.

It is clear, however, that the three waiting steps are not efficient and reduce the throughput rate.

Therefore, the new approach is to reduce or to eliminate the waiting steps. This can be accomplished by beginning the next task as soon as the prints are imaged instead of waiting until they clear the paper path. Several functions can be performed while the imaged print is traversing the paper path. There is, of course, the possibility of a malfunction such as a paper jam of the print in the paper path.

To provide for the contingency of a paper jam, tables and pointers must be saved so that the incompleted task can be repeated. This is illustrated in Flowchart B.

Jobs can usually be finished as soon as the last sheet is billed because the clean-up and initializing tasks were already completed.

The throughput rate can also be improved by reducing the time delays in duplex printing, i.e., printing on both sides of the paper.

Where performing a duplex print job, the first sides must be printed and the one-sided prints collected in a duplex tray before printing on the second side can begin. If a second job follows the first, the usual practice is to wait until all the two-sided prints have cleared the paper path before initiating the ne...