| 摘要 |
PROBLEM TO BE SOLVED: To prevent the increase in the size of a motor substrate for the dustproof cap which prevents the contamination of a rotary ploygon mirror. SOLUTION: A rotary ploygon mirror 3, which rotates by a motor 3a, is covered by a dustproof cap 16 which encircles the entire body of a motor substrate 12. The cap 16 is assembled outside the substrate 12. Thus, there is no possibility that the effective area of the substrate 12 becomes smaller similarly to in the case of a mirror cover that is mounted on the substrate 12. A motor driving IC part 12a, which is a heat generating section, is exposed from an opening section 16a of the cap 16. |
