초록 ▼

Optical alignment of the relative positions of cooperating masks and substrates is achieved for use in the generation by x-radiation of complex and compact patterns. Small fiduciary marks are actually illuminated by coherent visible light and the resultant diffraction patterns are used for alignment

Optical alignment of the relative positions of cooperating masks and substrates is achieved for use in the generation by x-radiation of complex and compact patterns. Small fiduciary marks are actually illuminated by coherent visible light and the resultant diffraction patterns are used for alignment purposes. Fresnel half-period zone plates are used to produce interference patterns in the form of an operator-observable information bearing pattern on a viewable screen.

대표청구항 ▼

Apparatus for aligning a first planar optically transparent element with respect to a second planar optically transparent element disposed in substantially parallel relation comprising: first and second thin films affixed to major adjacent surfaces of said first and second planar elements respective

Apparatus for aligning a first planar optically transparent element with respect to a second planar optically transparent element disposed in substantially parallel relation comprising: first and second thin films affixed to major adjacent surfaces of said first and second planar elements respectively, said films being provided with first and second apertures respectively, each of said apertures containing a Fresnel zone plate, means for illuminating said Fresnel zone plate with collimated light, and means for viewing an interference pattern formed by light passing through said Fresnel zone plates.