Image forming apparatus including feed permission control that depends on heating power of the fusing apparatus

摘要

An image forming apparatus includes a fusing apparatus including a fusing member; a heating unit heating the fusing member; temperature detecting units detecting temperatures of the fusing member and a pressing member; and the pressing member forming a fusing nip with the fusing member for fusing an un-fused image on a recording medium onto a recording medium. The image forming apparatus further includes a heating power determining unit determining heating power of the fusing apparatus by measuring a time or a gradient of time versus temperature before the temperature of the fusing member reaches a reload temperature after power is turned on. The image forming apparatus includes a control unit performing a feed permission control or a CPM down control depending on the heating power of the fusing apparatus and the number of sheets of the recording medium to be passed through the fusing apparatus.

主权项

1. An image forming apparatus comprising:
a fusing apparatus including
a fusing member;a heating unit configured to heat the fusing member;a first temperature detecting unit configured to detect a temperature of the fusing member;a pressing member disposed opposite to the fusing member and configured to form a fusing nip with the fusing member for fusing an un-fused image on a recording medium onto the recording medium; anda second temperature detecting unit configured to detect a temperature of the pressing member; a first unit configured to obtain a print job sheet number; a heating power determining unit configured to determine heating power of the fusing apparatus by measuring a time or a gradient of time versus temperature before the temperature of the fusing member reaches a reload temperature defining a minimum temperature at which the recording medium can be fed through the fusing apparatus, after the image forming apparatus is turned on; and a control unit configured to perform a feed permission control or a CPM (copy per minute) down control depending on the heating power of the fusing apparatus and the print job sheet number, wherein the feed permission control permits the feeding of the recording medium when the temperature of the pressing member reaches a feed permitting temperature, wherein the control unit is configured to perform a first control when the time or the gradient is equal to or less than a first predetermined value, the first control including the feed permission control permitting the feeding of the recording medium when the temperature of the pressing member reaches a first feed permitting temperature without performing the CPM down control, wherein, when the time or the gradient is greater than the first predetermined value, the control unit is configured to perform the first control, a second control, or a third control based on a prediction of a degree of decrease of the temperature of the fusing member after the feeding of one or more sheets of the recording medium, and wherein the second control and the third control include selecting the feed permission control or the CPM down control, whichever control is capable of completing the output of a number of sheets of the recording media corresponding to the print job sheet number.