title: Small-angle diffusing screens for photolithographic camera illumination systems.
abstract: A method is described for producing transmitting screens that diffuse light into small angles. With these screens, the amount of small-angle diffusion can be controlled while light loss from large-angle scattering is kept to a minimum. The diffusers are fabricated from two glass substrates that are ground, etched, and cemented together. There is a controlled mismatch between the optical index of the cement and that of the substrates. The screens were primarily designed for photolithographic camera illumination systems that involve a tradeoff between luminance and uniformity.
authors.forename: M C
authors.initials: MC
authors.lastname: King
authors.forename: D H
authors.initials: DH
authors.lastname: Berry