| 摘要 |
<p>The projection system consists of a light source (1) with an infra-red transmitting parabolic reflector directing a beam through a condenser pair of lenses with a filter device. The condenser optical axis coincides with that of the projector objective. Between the condenser and the projector objective is the slide for projection, for which may be substituted a special unit with a rectangular frame (6) retaining an opaque reflective foil (9) on the side facing the light source, and a thin liquid crystal film (10) on the opposite side. The foil is typically of silver or aluminium metal. The liquid crystals have thermally responsive properties and the temperature distribution may be recorded on a photographic emulsion.</p> |
