Beam position adjusting method and device for optical scanning apparatus

An optical scanning apparatus using galvanomirrors each having a mirror face the angle of which can be changed by supplying power to the galvanomirror, the apparatus also using sensors which detects positions on the sensors through which laser beams to be scanned pass so that the passage positions of the light passing through the sensors can be adjusted by changing the angles of mirror faces of the galvanomirrors, the apparatus comprising:

• a storage section which stores the value of power supplied to the galvanomirrors as information on mirror face angles at which the galvanomirrors are located;
• storage control means for causing the storage section to store the information on the angles of the mirror faces while not supplying power to the galvanomirrors;
• and
• driving control means for reading the information on the angles of the mirror faces stored in the storage section while supplying the power to the galvanomirrors and for displacing the galvanomirrors on the basis of the information on the angles of the mirror faces.

An optical scanning apparatus comprising:

• a plurality of light sources each of which emits light of a predetermined wavelength;
• optical-path aligning means for positioning light beams from the respective light sources at predetermined intervals in a first direction to synthesize the light beams so that the beams appear single;
• polarizing means for polarizing the light beams form the respective light sources synthesized by the optical-path aligning means so that the beams travel along a second direction orthogonal to the first direction;
• displacement detecting means for detecting displacement of the optical-path aligning means with respect to the first direction by detecting at least one of the light beams from the respective light sources which are polarized by the polarizing means;
• a storage section which stores the displacement of the optical-path aligning means detected by the displacement detecting means;
• and
• a driving means for energizing the optical-path aligning means and for aligning the displacement of the optical-path aligning means so as to provide such light beams that the light beams from the respective light sources can be considered to be single.