METHOD OF PREVENTING OVERHEAT OF PRINTING HEAD

摘要

The invention relates to apparatus for limiting the operating temperature of the print head (16) of a printer which comprises temperature determining means for determining the operating temperature of the print head, comparison means for comparing the operating temperature with a threshold value, and printer control means for preventing operation of the printer when the print head operating temperature exceeds the threshold value. …The apparatus of the invention is characterised in that the temperature determining means comprises estimating means (110 - 140) for estimating the initial value of the operating temperature and modifying means (115 - 210) responsive to the operation of the printer during predetermined time periods for modifying the estimated operating temperature at the end of each of the time periods based upon the amount of printing performed during the time period and the value of the estimated operating temperature. The printer control means prevents operation of the printer when the estimated print head operating temperature exceeds the threshold value.