Image forming apparatus

摘要

The detector that detects a light beam emitted from a light source of a second image forming device and reflected by a polygon mirror, and an adjustment device that performs adjustment processing of adjusting the velocity of the polygon mirror based on an output of the detector are provided. Before a first image forming device performs the image forming processing, the adjustment device performs the adjustment processing while causing the light source of the second image forming device to emit the light beam during a time period including at least a time period in which a photosensitive member of the second image forming device is emitted with the light beam. Before the adjustment processing is finished, the first image forming device starts to move a developing member to a developing position.

主权项

1. An image forming apparatus comprising:
first and second image forming devices each of which includes a photosensitive member, a light source that emits a light beam, and a developing member movable between a developing position and a retracted position retracted from the developing position; a polygon mirror that rotates and reflects each of the light beams emitted from the light sources of the first and second image forming devices; a detector that detects the light beam emitted from the light source of the second image forming device and reflected by the polygon mirror; and an adjustment device configured to perform an adjustment processing of adjusting a rotation velocity of the polygon mirror based on an output of the detector, the output being obtained during a period when the light beam is emitted from the light source of the second image forming device while the polygon mirror rotates so that the photosensitive member of the second image forming device and the detector are irradiated with the light beam emitted from the light source of the second image forming device and reflected by the polygon mirror, wherein each of the first and second image forming devices forms a latent image by irradiating the photosensitive member with the light beam emitted from the light source and then reflected by the polygon mirror and each is configured to develop the latent image with toner in order from the first image forming device to the second image forming device by the developing member at the developing position, in each of the first and second image forming devices, wherein the adjustment device performs the adjustment processing before the first image forming device forms a latent image on the photosensitive member, and wherein the developing member of the first image forming device starts moving to the developing position before the adjustment processing is finished, and the developing member of the second image forming device is positioned at the retracted position while the adjustment processing is performed.