Browse Prior Art Database

Determining Number of Minutes Remaining Until Fuser Hot Roll Reaches Operating Temperature

IP.com Disclosure Number: IPCOM000036914D
Original Publication Date: 1989-Nov-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 3 page(s) / 82K

Publishing Venue

IBM

Related People

Gunnell, RW: AUTHOR [+4]

Abstract

Fig. 1 shows a basic overview of a design used for controlling fuser hot roll temperature on a copier or a printer. Fig. 1 also shows a CRT which is used for displaying data. Item A is a fuser hot roll which contains a lamp driven by AC voltage in order to heat up the fuser hot roll. Item B is a thermistor which makes thermal contact (Image Omitted)

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 55% of the total text.

Page 1 of 3

Determining Number of Minutes Remaining Until Fuser Hot Roll Reaches Operating Temperature

Fig. 1 shows a basic overview of a design used for controlling fuser hot roll temperature on a copier or a printer. Fig. 1 also shows a CRT which is used for displaying data. Item A is a fuser hot roll which contains a lamp driven by AC voltage in order to heat up the fuser hot roll. Item B is a thermistor which makes thermal contact

(Image Omitted)

with the fuser hot roll. Item C is some analog circuitry which interprets the resistance of the thermistor and generates a digital pulse. Item D is the digital pulse generated by the analog circuitry. The frequency of the digital pulse will vary in relation to the thermistor resistance. Item E is a micro-processor used to measure the frequency of the digital pulse and to send data to the CRT. Item F is a CRT used to display data sent by the micro-processor.

As the fuser lamp is heated up, the thermistor resistance decreases. This causes a change in the digital pulse. The up time of the digital pulse will remain at a fixed constant. The down time of the digital pulse will decrease as the thermistor resistance decreases.

The micro-processor measures the down time of the digital pulse and compares it to a predetermined value which is defined as the proper operating temperature for the fuser hot roll. When the proper operating temperature is reached, the lamp is deactivated and information is sent to the CRT indicating that the fuser hot roll is up to the proper operating temperature.

By comparing the length of the pulse dow...