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Duty Control Algorithm for Impact Printer

IP.com Disclosure Number: IPCOM000121874D
Original Publication Date: 1991-Oct-01
Included in the Prior Art Database: 2005-Apr-03
Document File: 3 page(s) / 66K

Publishing Venue

IBM

Related People

Harahata, M: AUTHOR [+3]

Abstract

Disclosed is an algorithm for print duty control of impact printers. The algorithm, which enables impact printers to achieve higher throughput with small power supply, is widely applicable to all impact printers, especially spring charge-type printers. It is explained in 9-wire printer application case in this article; however, this algorithm is also applicable, e.g., to 18-, 24-, 48-wire printers and any other number of wires impact printers.

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Duty Control Algorithm for Impact Printer

      Disclosed is an algorithm for print duty control of
impact printers.  The algorithm, which enables impact printers to
achieve higher throughput with small power supply, is widely
applicable to all impact printers, especially spring charge-type
printers. It is explained in 9-wire printer application case in this
article; however, this algorithm is also applicable, e.g., to 18-,
24-, 48-wire printers and any other number of wires impact printers.

      In the prior art, power consumption is estimated from the
number of dots, and print duty control is required in order to
prevent overload of power supply if the dot count is over the
threshold. The threshold is defined to cover the maximum power
consumption case among various print patterns of the same dot count,
because power consumption per dot differs by print patterns and it
increases with an increase in the number of simultaneous firing dots.
Fig. 1 shows an example of power consumption per dot vs. number of
simultaneous firing dots. Printer systems, therefore, should have
unnecessary throughput down due to inaccuracy of estimated power
consumption.

      The unique feature of this algorithm is a weighted dot count
generator. Fig. 2 shows a diagram of weighted dot count generator.
This generator outputs weighted dot count values, which is a function
of simultaneous print bit pattern. Read-only memory (ROM), which
stores power consumption data of each possible s...