Patent ID: 8634123

Claim:
An optical scanning device configured to cause a light beam to scan a photosensitive drum to form a latent image on the photosensitive drum, the optical scanning device comprising: a first light emitting unit configured to emit a first light beam; a second light emitting unit configured to emit a second light beam; a light deflecting unit having deflecting surfaces and being configured to cause the first and second light beams emitted from the first and second light emitting units to reflect at the deflecting surfaces and deflect and scan in a main scanning direction; a cylindrical lens disposed between the first and second light emitting units and the light deflecting unit, the cylindrical lens being configured to cause the first and second light beams emitted from the first and second light emitting units to be directed along the main scanning direction to the deflecting surfaces; a holder configured to hold the cylindrical lens; and an aperture member disposed between the cylindrical lens and the light deflecting unit, the aperture member including a first portion and a second portion connected to each other at a connected position, the first portion having a first aperture and being shaped such that the first portion extends from the connected position toward a side opposite to the second portion with increasing distance from the cylindrical lens, the second portion having a second aperture and being shaped such that the second portion extends from the connected position toward a side opposite to the first portion with increasing distance from the cylindrical lens, the first aperture of the first portion being configured to regulate a width of the first light beam incident from the cylindrical lens at least in a sub scanning direction perpendicular to the main scanning direction, the second aperture of the second portion being configured to regulate a width of the second light beam incident from the cylindrical lens at least in the sub scanning direction.