| 摘要 |
PROBLEM TO BE SOLVED: To obviate an increase in parts and to avert an increase in cost and an increase in the size of an optical deflector by providing a case for housing a rotary polyhedral mirror and a means for rotating this rotary polyhedral mirror at high speed with heat radiation fins. SOLUTION: The case 20 is internally provided with a rotating section mainly constituting the rotary polyhedral mirror 30 and a dynamic pressure bearing device 32 and a static section mainly consisting of a coil substrate 22, a coil 23, a shaft 26, etc. An upper cap 21 is fixed by means of screws to the case 20. Moltopren (R) 24 is inserted between the case 20 and the upper cap 21. The case 20 has the many heat radiation fins 201 in its lower part to escape the heat generated at the time of the high-speed rotation of the rotary polyhedral mirror 30. The outside surfaces of the case 20, i.e., the parts of the fins are subjected to a black anodizing treatment. The heat radiation effect is additionally enhanced by this black anodizing treatment. Further, the front surface of the upper cap 21 is also subjected to the anodizing treatment, by which the heat radiation effect is additionally enhanced. |
