Patent ID: 8654168
Filing Date: 2014-02-18
Classification: B41J,G02B

Abstract:
1. An optical scanning device comprising: a light source having multiple light emitters to emit light beams; an optical element located on a light path of the light beams emitted by the light source to reflect part of the light beams while transmitting residue of the light beams; a photoreceiver located on a light path of the light beams reflected by the optical element and including a photodetector having a light receiving surface to receive the light beams reflected by the optical element; an aperture having an opening to shape the light beams passing through the optical element; a light deflector to deflect the light beams passing through the opening of the aperture; a scanning optics to guide the deflected light beams to a surface of an object to scan the surface with the light beams; and a coupling lens to converge the light beams passing through the optical element before the light beams pass through the opening of the aperture, wherein the optical scanning device satisfies the following relation: 1.3>[(Sp wherein there is no aperture in a light path from an exit face of the light source to the photodetector via the optical element, and a size of the light receiving surface of the photodetector is determined in such a manner that even when a full width at half maximum (FWHM) of each of the light beams emitted by the light source changes, a rate of change of a ratio of a light quantity of the light beams received by the photodetector to a light quantity of the light beams passing through the opening of the aperture is not greater than 4% and is greater than 0%, the light source is a face emitting laser, the optical element includes a glass plate and a half mirror locate on the glass plate and the photoreceiver further includes an amplifier to amplify a current generated by the photodetector when receiving the light beams reflected by the half mirror, wherein the glass plate protects the light source and the photoreceiver, and the half mirror is slanting relative to a plane perpendicular to a travelling direction of the light beams emitted by the face emitting laser while having a reflectance of not greater than 10%, and wherein the face emitting laser, the glass plate, and the photodetector are integrated as a single module.