| 摘要 |
1322422 Head-up displays SUNDSTRAND DATA CONTROL Inc 21 June 1971 [22 June 1970] 28997/71 Heading G2J A head-up display comprises an ellipsoidal mirror 24 and means 26 for generating an image for the mirror in the focal plane of the mirror. The reflective surface is part of a surface of revolution of an ellipse about one of its axes, preferably its major axis, the reflective surface being taken substantially from one hemiellipsoid and adjacent but offset from the axis of revolution, which axis constitutes the optical axis of the reflective surface. As shown, the ellipsoidal mirror is partially reflective. However, the mirror may be fully reflective, and a partially reflective plane mirror arranged to . reflect the image from the ellipsoidal mirror, Fig.17 (not shown). The device is applied to an aircraft, and images 40, 42, Fig.2, are produced to represent the aircraft pitch angle and the projected flight path. Image 40 is produced by a movable tape carrying translucent indicia held in front of a light source, the front of which is so shaped that the tape lies in the (curved) focal plane. The image 42 is produced by a movable illuminated bar which is also curved to lie in the focal plane. The illumination may be controlled relative to ambient light to give a desired contrast. The mirror 24 may be pivoted to lie against base 22 when not in use, the illumination being switched off when it is in the stowed position. |
