JP2002328325A5

JP2002328325A5 -

Info

Publication number: JP2002328325A5
Application number: JP2001130845A
Authority: JP
Filing date: 2001-04-27
Publication date: 2004-08-26

Description

【００２９】
また、図４に示すようにレーザ反射面５０に入射するレーザ光束１６ａ、１６ｂの主走査方向の位置は、光学絞り３の左右（矢印Ｃ方向）の位置で決まる。ゆえに、光学絞り３の左右の位置精度が悪いと、レーザ反射面５０はその分広く必要となるので、回転多面鏡４は大型化してしまう。[0029]
Further, as shown in FIG. 4, the positions in the main scanning direction of the laser light beams 16 a and 16 b incident on the laser reflection surface 50 are determined by the positions of the optical diaphragm 3 in the left and right direction (arrow C direction). Therefore, if the positional precision on the left and right of the optical diaphragm 3 is poor, the laser reflecting surface 50 is required to be wide accordingly, and the polygon mirror 4 is upsized.

【００３１】
また、図４において、例えば本走査光学装置と感光体の位置精度が狂ったなどしてピントずれが生じ、感光体９が１１３の位置にずれたとする。すると、発光点１４ａ、１４ｂから出射したレーザ光束１６ａ、１６ｃは感光体１１３上で間隔ｈ２だけ離間して結像されることになる。ここで、光学絞り３が回転多面鏡４に近づき、間隔ｈが小さくなると、１６ａと１６ｃのなす角αが小さくなるため、間隔ｈ２も必然的に小さく抑えることができる。[0031]
Further, in FIG. 4, for example, it is assumed that the positional deviation between the main scanning optical device and the photosensitive member is deviated or the like causes a focus shift, and the photosensitive member 9 is shifted to the position 113. Then, the laser beams 16a and 16c emitted from the light emitting points 14a and 14b are separated and formed on the photosensitive member 113 by the distance h2. Here, when the optical aperture stop 3 approaches the rotary polygon mirror 4 and the distance h becomes smaller, the angle α between 16a and 16c becomes smaller, so the distance h2 can be necessarily kept small.