Patent ID: 7706702
Filing Date: 2010-04-27
Classification: G03G

Abstract:
1. An image forming apparatus for forming an image on a recording sheet by transferring a developer image to the recording sheet, the apparatus comprising: a developer casing which accommodates a developer; an agitation member, provided to be rotated in the developer casing, which agitates the developer; a light emitting unit, arranged at one end in a rotation axis direction of the agitation member, which emits light to the other end in the rotation axis direction of the agitation member through the developer casing; a light receiving unit, arranged at the other end in the rotation axis direction of the agitation member, which receives the light emitted from the light emitting unit; a signal output unit which outputs an interval signal at a predetermined time interval; a light reception determination unit which determines whether light has been received in the light receiving unit when the interval signal has been output; a counting unit which sets a predetermined number of times of outputting to one period and counts a number of times the interval signal is output; a remaining amount determination unit which determines an amount of the developer remaining in the developer casing on a basis of a ratio of a number of times of determining, by the light reception determination unit, that light has been received in the light receiving unit within the one period and the predetermined number of times of outputting, wherein a product of the predetermined time interval and the predetermined number of times of outputting is set to be an integer multiple of a time required for one rotation of the agitation member; and a setting change unit which changes at least one of the predetermined time interval and the predetermined number of times of outputting on a basis of the time required for the one rotation of the agitation member.