Image forming apparatus with density data correction

摘要

An image forming apparatus that reduces the downtime due to image density control is provided. To accomplish this, the image forming apparatus obtains, using a sensor, background data at a plurality of measurement positions from a rotation member, and density data at a plurality of measurement positions from a patch image formed on the rotation member. Further, the image forming apparatus normalizes density data based on first background data and calculates first correction density data, and also normalizes density data based on second background data for which the measurement positions have been shifted from those of the first background data, calculates second correction density data, and acquires corrected density data in accordance with the first correction density data or the second correction density data that has a smaller variation.

主权项

1. An image forming apparatus comprising:
a rotation member that is used for image formation; a detection unit that irradiates a detection target with light and detects reflected light from the detection target; a first obtaining unit that obtains background data at a first number of measurement positions, including a given number of measurement positions on the rotation members, based on a detection result of the detection unit by detecting reflected light from the rotation member, which is the detection target; a second obtaining unit that obtains density data of a toner image at a second number of measurement positions lower in number than the first number of measurement positions, based on a detection result by the detection unit by detecting reflected light from the toner image for adjusting an image density of an image formed on the rotation member; a calculating unit that normalizes the density data in an obtaining result by the second obtaining unit based on first background data of the second number of measurement positions corresponding to a reference position of the measurement positions on the rotation member, which is assumed when a circumference of the rotation member is not changed from a reference circumference from among an obtaining result by the first obtaining unit, and calculates first correction density data, and normalizes the density data in an obtaining result by the second obtaining unit based on a predetermined number of second background data in the second number of measurement positions, each of which have been respectively shifted by a different number from the measurement positions of the first background data, from among the obtaining result by the first obtaining unit, and calculates a predetermined number of second correction density data; and a determination unit that determines that the correction density data has a smaller variation between a plurality of density values respectively included therein from among the first correction data and the predetermined number of second correction data, wherein corrected density data is obtained in accordance with the determination by the determination unit.