| 摘要 |
An image-forming device has an image-forming unit, a toner density detection unit, a reflective shutter, a storage unit, and a control unit. The image-forming unit forms a toner image on an image-carrying member. The toner density detection unit 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. The reflective shutter is provided between the toner density detection unit and the image-carrying member to be movable between a shielding position and a retracted position. The storage unit stores the output value of the toner density detection unit. The control unit calculates a correction value for correcting the output value to control an image-forming unit according to the correction value. 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. The control unit calculates a ratio of the second value and the first value and then calculates the correction value based on the ratio.
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