| 摘要 |
PROBLEM TO BE SOLVED: To prevent generation of a gap allowing entry of dust between a chassis and an upper cover by providing a seal member at the internal surface of an upper cover and is the compression-bonded at the upper end surface of at least one side plate of chassis. SOLUTION: At the lower surface of an upper cover 42, a sealing member 291 is attached almost in the U-shape and the four engaging holes 285 of the upper cover 42 are engaged with the four engaging pawls 286 of a chassis 41 by covering the upper part of chassis 41 with the upper cover 42. When the upper cover 42 is removably mounted on the chassis 41, the seal member 291 can be compression-bonded to the upper end surfaces 41b3, 41c3 and 271c of the three side plates 41b, 41c and dust shield part 271 of the chassis 41 against elasticity thereof. Thereby, the gaps between the upper end surfaces 41b3, 41c3 and 271c of the three side plates 41b, 41c and dust shield part 271 of three chassis 41 and the ceiling part 42a can be sealed.
|
