Patent ID: 8010035
Filing Date: 2011-08-30
Classification: G03G

Abstract:
1. An image forming apparatus comprising: a sheet-feeding section for taking out and feeding a recording sheet stored in a sheet cassette; an image forming section including: image forming devices provided for respective colors for forming a monochromatic or color toner image; an image bearing member for bearing a toner image formed by the image forming devices; and a transferring device for transferring the toner image formed on the image bearing member to the recording sheet conveyed by the sheet-feeding section; a sheet amount detector for detecting the amount of recording sheets stored in the sheet cassette; an instruction reception section for receiving an image forming instruction to form the toner image on the recording sheet; a mode controller for executing an image formation preceding mode operation of allowing the image forming devices to start their respective image forming operations before the sheet feeding section conveys the recording sheet from the sheet cassette when the instruction reception section receives the image forming instruction and the amount of recording sheets detected by the sheet amount detector is greater than a predetermined reference amount, and executing a sheet conveyance preceding mode operation of allowing the image forming devices to start their respective image forming operations after the sheet-feeding section conveys the recording sheet from the sheet cassette when the instruction reception section receives the image forming instruction and the amount of recording sheets detected by the sheet amount detector is smaller than the reference amount; and a farthest position detector for detecting, among the image forming devices which perform respective image forming operations in connection with the image forming instruction, the image forming device which is located at a position having a longest moving distance of the toner image to the transferring device on a moving course of the image bearing member when the instruction reception section receives the image forming instruction, wherein when the instruction reception section receives the image forming instruction and the amount of recording sheets detected by the sheet amount detector is greater than the reference amount, the mode controller executes the image formation preceding mode operation when a distance between the image forming device detected by the farthest position detector and an image transfer position of the transferring device is longer than a distance between the sheet cassette and the image transfer position of the transferring device, and executes the sheet conveyance preceding mode operation when the distance between the image forming device detected by the farthest position detector and the image transfer position of the transferring device is shorter than the distance between the sheet cassette and the image transfer position of the transferring device.