Patent ID: 7751735
Filing Date: 2010-07-06
Classification: G03G

Abstract:
1. An image-forming device, comprising: an image-forming unit that forms a toner image on an image-carrying member; a toner density detection unit that detects a toner density of the toner image, the toner density detection unit having a light-emitting element for emitting a light beam to the image-carrying member, and a light-receiving element for receiving the light beam to produce an output value based on an intensity of the received light beam; a reflective shutter provided between the toner density detection unit and the image-carrying member to be movable between a shielding position and a retracted position; a storage unit that stores the output value of the toner density detection unit; and a control unit that calculates a correction value for correcting the output value to control an image-forming unit according to the correction value, wherein the image-forming unit forms a reference toner image on the image-carrying member, the toner density detection unit receives a reflected light beam from the reflective shutter positioned at the shielding position to generate a first output value, the first output value being stored in the storage unit, the toner density detection unit receives another reflected light beam from the reference toner image to generate a second output value when the reflective shutter is positioned at the retracted position, the second output value being stored in the storage unit, and the control unit calculates a ratio of the second value and the first value and then calculates the correction value based on the ratio.