Patent ID: 8451307
Filing Date: 2013-05-28
Classification: B41J,G02B

Abstract:
1. An optical scanning device that scans at least one scanning surface with a light beam, the optical scanning device comprising: a light source having a plurality of light-emitting units; a pre-deflector optical system including an isolator that is arranged on an optical path of a light beam from the light source, the isolator having a first surface with different light transmittances depending on a polarization state of an incident light beam on its first side close to the light source and a second surface imparting an optical phase difference of a quarter wavelength to the incident light beam on its second side opposite to the first side along the optical path; a photoreceiver; a half mirror for splitting the light beam into first and second split beams, and for transmitting the second split beam toward the photoreceiver; a deflector that deflects the first split beam; a rotation mechanism that rotates the isolator around an optical axis of the isolator; and a holding member that holds the light source and the isolator in a predetermined positional relationship; and wherein the photoreceiver is configured to detect an optical intensity of the second split beam; and the isolator is located between the light source and the half mirror on the optical path of the light beam from the light source.