| 摘要 |
<p>PURPOSE:To prevent the waterdrops from entering a frame by the capillarity by forming the notches on both side faces and at the lower end part of a rear of the frame respectively. CONSTITUTION:A housing frame 10 is vertically long and has a U-shaped section. A filter is put into an opening part 12 of the front face of the frame 10 so that a cavity 24 is formed. A projecting or a photodetecting unit is built into the cavity 24. The notches 18 are formed on both side faces 14 and at the lower end part of a rear 16 of the frame 10 respectively. When a protruding part 30 of a lower cap 26 is put into the cavity 24, a drainage hole is formed by the notches 18 among the faces 14 and 16 of the frame 10 and a side face part 28 of the part 30. This drainage hole also serves as an air vent, and the capillarity never occurs even if a minute gap is formed by a contact secured between the frame 10 and the part 28. Furthermore the waterdrops, if produced in the gap, can be discharged through the notches 18.</p> |
