JPS57101871A - Control method for copying machine - Google Patents

Abstract

PURPOSE:To reduce a preheating period, that is, a copying time, by starting copying at the fixing device temp. lower as compared to that when the number of copying sheets is large, when it is small. CONSTITUTION:First, the temp. T2 of a thermal fixing device necessary for copying nF sheets is empirically determined. Now, a continuously copiable temp. T1 and the nF-sheet fixable temp. T2 are stored in a temp. detector, and nF- sheets of copying number is stored in a comparator. As an electric power source is switched on, the temp. on the heat fixing device begins to rise. Thence, ns sheets of desired copying number is set, and when a copying button is pushed, the copying cycle of ns sheets is started from the time t4 when the thermal fixing temp. attains the temp. T2 in case when the desired copying number ns and the set copying number nF are ns<=nF. At T2<TF, an H signal is output from the temp. detector, and this is a copying start signal. Thereby, while the time t2 is heretofore required to copy ns sheets, it is reduced to the time t5 and the copying time is thus reduced.