4,811,328 3/1989 Ito et al 350/170
4,851,978 7/1989 Ichihara 350/167
4,918,583 4/1990 Kudo et al 350/167
4,939,630 7/1990 Kikuchi et al 350/167
4,974,919 12/1990 Muraki et al 350/6.6
FOREIGN PATENT DOCUMENTS
31969 4/1973 Japan .
111832 1/1979 Japan .
226317 12/1984 Japan 350/167
162218 8/1985 Japan .
32555 2/1988 Japan 350/167
Primary Examiner—Jon W. Henry
Attorney, Agent, or Firm—Fitzpatrick, Cella, Harper &
Scinto
[57] ABSTRACT
An illumination device includes a raidation source; an optical integrator having an array of lenses disposed along a plane perpendicular to an optical axis of the device; a first optical system for amplitude-dividing a coherent beam from the radiation source and producing plural beams which are substantially incoherent with each other, the first optical system also being effective to project the beams to the optical integrator in different directions and to superpose the beams upon one another on the optical integrator; and a second optical system for directing beams from the lenses of the optical integrator to a surface to be illuminated and for superposing the beams upon one another on the surface to be illuminated.
23 Claims, 12 Drawing Sheets