| 摘要 |
PROBLEM TO BE SOLVED: To prevent the erroneous insertion of a filter when the filter is inserted with the face/back of the filter in the incorrect orientation by making the threading of the filter impossible.SOLUTION: A locking section 31 for holding the end of a filter 7 that is mounted with the face side thereof being inserted toward a front surface is provided on a cabinet 3. A receiving rib 25 that configures a high/low portion is provided at a lower end of the face side of the filter 7, and an end of the back side of the filter 7 is formed smoothly. When the filter 7 is inserted with the face/back of the filter 7 in the correct orientation, the lower end of the filter 7 is inserted without touching the locking section 31, the receiving rib 25 abuts on the locking section 31, and the filter 7 is held. When the filter 7 is inserted with the face/back of the filter 7 in the incorrect orientation, a low portion of the high/low portion of the filter 7 abuts on the locking section 31, and insertion of the filter 7 is impeded. |
