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Monitoring of Heating and Other Usage in Printers

IP.com Disclosure Number: IPCOM000034908D
Original Publication Date: 1989-May-01
Included in the Prior Art Database: 2005-Jan-27
Document File: 1 page(s) / 13K

Publishing Venue

IBM

Related People

Hardin, KB: AUTHOR

Abstract

A representative formula to monitor heating of a printhead or motor resulting from intermittent use, such as in printing, is as follows: C x Pprev + X, where C is a positive constant less than one, Pprev is the immediately previous result from the formula, and X is directly determined by the amount of usage of the printhead and motor occurring after the previous computation. This computation is repeated at short intervals, such as every second for printhead usage and for every line for motors which move the printhead and their circuits. Where X is based on the number of wires fired in a printhead, a temperature sensor in the printhead is monitored to revise the constants in the formula defining X.

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Monitoring of Heating and Other Usage in Printers

A representative formula to monitor heating of a printhead or motor resulting from intermittent use, such as in printing, is as follows: C x Pprev + X, where C is a positive constant less than one, Pprev is the immediately previous result from the formula, and X is directly determined by the amount of usage of the printhead and motor occurring after the previous computation. This computation is repeated at short intervals, such as every second for printhead usage and for every line for motors which move the printhead and their circuits. Where X is based on the number of wires fired in a printhead, a temperature sensor in the printhead is monitored to revise the constants in the formula defining X. During cooling periods and the like, X is zero and the formula is exponential in result, which conforms to normal cooling effects. Regardless of the period of cooling, Pprev never becomes zero or less because it is the result of a positive number multiplied by a fraction. For the printhead heating formula, the formula for X is as follow: C(fixed) x C(variable) x No.(number of wires fired in the interval from the last computation). C(fixed) depends on the printhead system characteristics and might be, for example, 0.00428915. C(variable) is adjusted for temperatures noted at the printhead by the following formula: C(variable)prev + or - 0.61, where C(variable)prev is simply the value of the immediately previous C(variable) and 0.61 depends of the printhead system characteristics. The 0.61 factor is added when the printhead sensor measures the printhead at hotter than a preselected printhead value. The 0.61 factor is subtracted when the printhead sensor measures the p...