Optical scanning unit and image forming apparatus incorporating same

An image forming apparatus, comprising:

• an optical scanning unit, including:
• a photoconductor;
• a light source for generating a light beam;
• a rotatable deflector configured to deflect the light beam generated by the light source to scan a surface of the photoconductor in a main scanning direction with the light beam,
• a driver configured to rotate the rotatable deflector;
• a scan lens configured to convert the light beam deflected by the rotatable deflector with equiangular motion speed to a light beam having constant speed motion to scan the photoconductor;
• an optical element, disposed along an optical path from the scan lens to the photoconductor surface, configured to guide the light beam passed through the scan lens;
• a first casing configured to house the light source, the rotatable deflector, and the scan lens;
• a second casing configured to house the first casing and optical element disposed along an optical path from the scan lens to the photoconductor;
• a first cover configured to cover at least the first casing;
• and
• a second cover configured to cover the optical element housed in the second casing,
• wherein the second cover includes an overlapping area that overlaps the first cover, and the first casing and the second casing are covered by the first cover and the second cover when the first cover is fixed to the second cover at the overlapping area.

An optical scanning unit for scanning a photoconductor, comprising:

• a light source for generating a light beam;
• a rotatable deflector configured to deflect the light beam generated by the light source to scan a surface of the photoconductor in a main scanning direction with the light beam,
• a driver configured to rotate the rotatable deflector;
• a scan lens configured to convert the light beam deflected by the rotatable deflector with equiangular motion speed to a light beam having constant speed motion to scan the photoconductor;
• an optical element, disposed along an optical path from the scan lens to the photoconductor surface, configured to guide the light beam passed through the scan lens;
• a first casing configured to house the light source, the rotatable deflector, and the scan lens;
• a second casing configured to house the first casing and the optical element disposed along an optical path from the scan lens to the photoconductor;
• a first cover configured to cover at least the first casing;
• and
• a second cover configured to cover the optical element housed in the second casing,
• wherein the first casing includes a rotatable deflector compartment for housing the rotatable deflector, and the second cover is extended to the rotatable deflector.

An optical scanning unit for scanning a photoconductor, comprising:

• a light source for generating a light beam;
• a rotatable deflector configured to deflect the light beam generated by the light source to scan a surface of the photoconductor in a main scanning direction with the light beam,
• a driver configured to rotate the rotatable deflector;
• a scan lens configured to convert the light beam deflected by the rotatable deflector with equiangular motion speed to a light beam having constant speed motion to scan the photoconductor;
• an optical element, disposed along an optical path from the scan lens to the photoconductor surface, configured to guide the light beam passed through the scan lens;
• a first casing configured to house the light source, the rotatable deflector, and the scan lens;
• a second casing configured to house the first casing and the optical element disposed along an optical path from the scan lens to the photoconductor;
• a first cover configured to cover at least the first casing;
• and
• a second cover configured to cover the optical element housed in the second casing,
• wherein the second cover has a portion directly facing a top surface of a side wall of a rotatable deflector compartment of the first casing, and the side wall is formed around the rotatable deflector.