| 摘要 |
PURPOSE:To eliminate the need for cold shielding and to shorten the time required for cooling by fitting a rotary elliptic surface type infrared-ray reflecting member and reducing noises equally to the cold shielding. CONSTITUTION:A dewer winder 2 is formed in a rotary elliptic surface shape obtained by rotating an ellipse around its minor axis and the infrared-ray reflecting member 8 is so constituted that an infrared ray which is incident on this rotary elliptic surface except the opening part of the window 2 and an infrared ray from inside the dewer 1 are reflected by the rotary elliptic surface. An infrared detecting element 3 is arranged within the range of the two focuses of the ellipse expressed by the tracks of the focus rotated around the minor axis of the ellipse. An infrared ray incident on the element 3 is only a fine quantity of infrared ray emitted by the element 3 and nearby it, and unnecessary infrared ray from other parts is no incident on the element 3. Consequently, the cold shielding is not necessary and the time required for the cooling is shortened. |
