Method of determining time to replace developing solution of printer

摘要

A method of determining a time to replace a developing solution in a printer includes providing a reference card including sample patches of standard colors for predetermined colors of the developing solutions, sample patches of test colors into which the standard colors change due to contamination, and standard color differences DELTAE* calculated from standard color values Es* corresponding to the respective standard colors and measured standard contamination values Ec* corresponding to the respective test colors; inputting information about test patches for the predetermined colors into the printer and printing the test patches; and comparing the sample patches with the test patches to determine whether to replace the developing solutions. Since the reference card is provided together with a printer including information about test patches, a user can easily determine a time to replace a developing solution.