| 摘要 |
<p>A head-up display for use in a vehicle is provided with a curved combiner (56) which reflects an image from a cathode ray tube (CRT) (28) as collimated rays to a viewing site. A relay lens (26) is positioned between the CRT (28) and the combiner (56) to magnify and transfer the image. The combiner may be a partially-reflecting mirror or holographic optical element or dielectric laminate. Included within the relay lens is a coma-control plate (44) having two-dimensional undulations described mathematically by a two-dimensional power series having odd symmetry in a plane of a tilting of the combiner and even symmetry in the perpendicular dimension. The coma-control plate (44) substantially reduces coma in an image presented for viewing at infinity, the coma being introduced by the curvature and off-axis use of a surface of the combiner.</p> |
