| 摘要 |
PROBLEM TO BE SOLVED: To obtain a tandem type scanning optical device that the positions of scanning lines with respect to respective photoreceptor drums can be adjusted to be constant even when a heat generating state is different between a housing in which scanning optical systems are housed and a drum supporting body in which the photoreceptor drums are housed. SOLUTION: In the respective scanning optical systems, 3rd lenses 133, 233, 333 and 433 having main power in a sub-scanning direction are made to abut on adjusting plates 162, 262, 362 and 462 by springs and relatively moved in the vertical-scanning direction with respect to the housing by utilizing the thermal deformation thereof so as to prevent the scanning lines formed on the photoreceptor drums 31, 32, 33 and 34 from being moved. In the 1st and the 4th scanning optical systems 100 and 400 that a distance to the 3rd lens from a deformation reference position S is short, the adjusting plates 162 and 462 whose width in the vertical-scanning direction is narrow are used. In the 2nd and the 3rd scanning optical systems 200 and 300 that the distance to the 3rd lens is long, the adjusting plates 262 and 362 whose width is wider are used.
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