Patent Document ID: 8521045
Application ID: 13160095
Patent Status: 1

Claim One:
1. An image forming apparatus that primarily transfers a toner image formed on an image carrier onto an intermediate transfer member, and secondarily transfers the toner image onto a recording sheet to form an image, the image forming apparatus comprising: a sensor operable to detect intensity of light, and output a voltage in accordance with the detected intensity of light; a detection data acquisition part operable to (i) set a plurality of reference voltages, which are each to be referred to when the sensor detects intensity of light reflected from a bare surface of the intermediate transfer member onto which a toner image has not yet been transferred, and (ii) acquire, at each set reference voltage, a voltage output by the sensor with respect to a predetermined area on the bare surface in a circumferential direction of the intermediate transfer member, as a piece of detection data; a detection data storage operable to store therein the acquired pieces of detection data in one-to-one correspondence with the reference voltages; a judgment part operable to judge whether to perform image density correction processing of correcting a density of a tonner image to be formed; an output level calibration part operable, when the judgment part judges affirmatively, to adjust an output level of the sensor at the detection of the intensity of light reflected from the bare surface for calibration so as to correspond to one of the reference voltages; a density data acquisition part operable to form a toner pattern within the predetermined area, and acquire density data of the toner pattern by causing the sensor, whose output level has been adjusted, to detect intensity of light reflected from the toner pattern; a density data correction part operable to read, from the detection data storage, one of the pieces of detection data corresponding to the reference voltage corresponding to the adjusted output level, and correct the acquired density data based on the read piece of detection data; and an image density correction part operable to perform the image density correction processing based on the corrected density data.