Heat roller fixing device

Abstract

Abstract PURPOSE:To obtain a clear copy free from irregularity by providing first and second set-temperatures, and controlling the preliminary rotation of a heat roller according to counted value detecting each set-temperature. CONSTITUTION:As the temperature at which fixing is started, the first set- temperature T1 and the second set-temperature T2, which is lower than the first one, are set. The time until the temperature reaches the second set- temperature T2 after a power source is turned on is counted. Control is exerted in such a manner that the preliminary rotation of the heat roller 51 is started at the time t2 after the fixed time (tS) according to a calculating formula or table is lapsed after the time t1 when the temperature sensor 54 detects the second set-temperature T2, and that the preliminary rotation is stopped at the time t3 when the temperature reaches the first set-temperature T1. During this, case the temperature of the surface of the heat roller 51 tentatively is dropped a little at the time t2 when the rotation is started; however, the temperature soon rises, and it takes time tV for the temperature to reach the first set-temprature at the time t3; consequently the rotation is stopped. Thus, a toner image can be fixed by the heat roller 51 whose temperature is always stable.

Inventors

• 👤 Koichi Gunji
• 👤 軍司　幸一
• 👤 Takaaki Yamanaka
• 👤 山中　孝明
• 👤 Hidetoshi Katayanagi
• 👤 秀敏 片柳

Bibliographic Details