Optical scanning device and image forming apparatus using same

摘要

Provided is an optical scanning device including a light source, a deflector, a scanning lens, a synchronizing sensor, a sensor lens and a control unit. The deflector causes a scanning line to be written within an effective scanning width of a surface to be scanned. The synchronizing sensor detects a light beam that is outside the range of the effective scanning width on a scanning start side of the scanning line. The control unit controls an emission operation of the light source, and starts the writing of the scanning line at a timing in which a fixed time is added to a timing that the synchronizing sensor has detected the light beam. The sensor lens includes a diffraction grating that bends the light beam in a downstream-side direction of the scanning line, and a bending degree of the light beam by the diffraction grating changes with temperature.

主权项

1. An optical scanning device, comprising:
a light source that emits a light beam having a wavelength that changes with temperature; a deflector that deflects the light beam emitted from the light source and causes the light beam to scan a range of a predetermined scannable width including a surface to be scanned, and causes a scanning line to be written within an effective scanning width that is set within the range of the scannable width; a scanning lens that is disposed between the deflector and the surface to be scanned, and images the light beam on the surface to be scanned; a synchronizing sensor that detects, of light beams that pass through the scanning lens and head toward the range of the scannable width, a light beam that is outside the range of the effective scanning width on a scanning start side of the scanning line; a sensor lens that is disposed between the deflector and the synchronizing sensor, the sensor lens being configured to allow the light beam to pass therethrough and to image the light beam on the synchronizing sensor; and a control unit that controls an emission operation of the light source, and starts the writing of the scanning line at a timing in which a fixed time is added to a timing that the synchronizing sensor has detected the light beam, wherein the sensor lens includes a diffraction grating that bends the light beam that passes through the sensor lens in a downstream-side direction of the scanning line, and a bending degree of the light beam by the diffraction grating changes with temperature.