Back-illuminated transparency contrast enhancement system
AssigneeMaxim Diagnostic Imaging
InventorAlbert Macovski
Life of this patent
Estimating the term…
Abstract
A transparency is illuminated from the back or non-viewing side through an array of apertures with a light source which is invisible to the viewer. This light passes through the apertures and, after passing through the transparency, is reflected back through the transparency to the aperture structure. The region between apertures is a light converter surface which converts the invisible light to visible light. The visible light passes through the transparency to the viewer with the multiple passes providing contrast enhancement. An additional visible light source is used to provide adequate brightness in relatively dense areas of the transparency.
Claims21
Apparatus for enhancing the contrast of a transparency as seen by a viewer comprising:
- ans aperture structure in substantial contact with the non-viewing side of the transparency having an array of transparent regions and having a light converter surface in the non-transparent regions for converting invisible light to visible light;
- a reflective means having a reflective surface in substantial contact with the viewing side of the transparency;
- and
- means for transmitting a first light component which is invisible to the viewer through the array of transparent regions and, after passing through the transparency, is reflected by the reflective means back through the transparency to the converter surface where it is converted into visible light which is transmitted through the transparency and the reflective means whereby the viewer sees a contrast enhancement of the transparency.
In a method of enhancing the contrast of a transparency the steps of:
- illuminating the transparency through an array of apertures with a source of light invisible to a viewer;
- reflecting the invisible light back through the transparency to a converter surface between the apertures;
- and
- converting the reflected invisible light to light visible to the viewer which is transmitted through the transparency to the viewer.
Dependencies are inferred from the claim text.