Optical scanning apparatus and image forming apparatus

An optical scanning apparatus, comprising:

• a light source unit which emits a light beam;
• a deflection scanning device which deflects the light beam emitted from the light source unit;
• an optical scanning unit having a scanning imaging lens and which scans a surface to be scanned;
• an optical housing having an inner surface and an outer surface, and provided with a fixing part to which a frame of an apparatus is mounted on the outer surface, the optical housing accommodating in a space surrounded by the inner surface of at least the deflection scanning device;
• and
• a light beam detector provided on the inner surface in a periphery of the fixing part away from the deflection scanning device, and which detects a position in a sub-scanning direction of the light beam.

An image forming apparatus which forms a latent image on a photoreceptor having a surface to be scanned with optical scanning to obtain a desired recording image by visualizing the latent image, the image forming apparatus comprising an optical scanning apparatus, including:

• a light source unit which emits a light beam;
• a deflection scanning device which deflects the light beam emitted from the light source unit;
• an optical scanning unit having a scanning imaging lens and which scans the surface to be scanned;
• and
• a light beam detector which detects a position in a sub-scanning direction of the light beam, and is disposed in a position maintaining a correlation, in a time-varying characteristic, between an amount of change of a position in the sub-scanning direction of the light beam on the surface to be scanned and an amount of change of a position in the sub-scanning direction of the light beam detected by the light beam detector, in which a difference between the amount of change of the position in the sub-scanning direction of the light beam on the surface to be scanned and the amount of change of the position in the sub-scanning direction of the light beam detected by the light beam detector is equal to or less than a set value.