| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve a cooling effect and to obtain stable performance. SOLUTION: A fan 35 is provided inside a vent hole 34 at the upper part of a frame 21, and shutters 29 and 36 opening/closing the upper and lower vent holes 28 and 34 are provided in a grounded state inside the vent holes 28 and 34. As for the shutters 29 and 36, mount plates 30 and 37 respectively having apertures 30a and 37a are mounted on the frame 21, and light shielding plates 31 and 38 are respectively mounted on the mount plates 30 and 37 through hinges 32 and 39, then gaskets 33 and 40 are respectively arranged between the mount plates 30 and 37 and the light shielding plates 31 and 38. The light shielding plates 31 and 38 are energized to an opening position by a spring, and driven to a closing position by a solenoid, etc. The light shielding plates 31 and 38 are at the closing position from the rotor-up time to normal reading, otherwise they are at the opening position.</p> |
