| 摘要 |
<p>An infrared optical assembly (10) comprises: an object optical assembly (13), further comprising a primary mirror (11) and an auxiliary mirror (12) which are positioned opposite one another along an optical axis (AX), wherein infrared rays from a detected object (not shown) are reflected first by the primary mirror (11), then the auxiliary mirror (12), forming an intermediate image of the detected object. A non-transmitting portion (12f) is present at the center part of the auxiliary mirror (12) whereupon the infrared rays from the detected object are not transmitted. The non-transmitting portion (12f) of the center part of the auxiliary mirror (12) is formed in a concave surface shape which satisfies formula (1), hereinafter: L / 1.2 < R < 1.5L (1); where R is the absolute value of the radius of curvature of the center part of the auxiliary mirror (12) which corresponds to the non-transmitting portion (12f), and L is the distance from the intermediate image formation site to the center part of the auxiliary mirror which corresponds to the non-transmitting portion.</p> |
