Optical system for uniform illumination of a plane surface

Patent · Tue Mar 14 04:00:00 EST 1989

OSTI ID:6083581

Hill, J D

An optical system is described for imaging a non-uniform light source onto an image plane to provide uniform illumination on the image plane, comprising: a focusing reflector for reflecting light rays and a source of light disposed on the optical axis of the reflector and on or near the focal point of the reflector. The source consists of en enclosed body of the luminous gas, the horizon of which appears, relative to the center, brighter near the poles and dimmer near the equator, or brighter near the equator and dimmer near the poles when viewed from a position near the equatorial plane, wherein the poles are points on the source which are on the optical axis of the focusing reflector. The equator represents points on the surface of the source in a plane through the geometrical center of the source and normal to the axis of the focusing reflector, and the horizon is a perimeter of the source viewed from any point outside the source. The light source is a bulb wherein the luminous gas is generated by a plasma forming medium and the focusing reflector forms a portion of a microwave cavity in which the bulb is located. The apparatus also includes a collimating lens disposed between the image plane and the light source at a distance from the light source so that the limiting aperture of the reflector is at or near the focal point of the lens, whereby light emanating from the source provides uniform and telecentric illumination on the image plane.

• Assignee: Fusion Systems Corp., Rockville, MD
• Patent Number(s): US 4812957
• OSTI ID: 6083581
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420800* -- Engineering-- Electronic Circuits & Devices-- (-1989)
ELECTROMAGNETIC RADIATION
FOCUSING
ILLUMINANCE
IMAGE PROCESSING
IMAGE SCANNERS
LENSES
LIGHT BULBS
OPTICAL SYSTEMS
PROCESSING
RADIATIONS
REFLECTION
SURFACES
VISIBLE RADIATION