Focal plate

Abstract

Abstract PURPOSE:To increase the luminosity of a finder image by arranging many curved surfaces in a micro lens shape regularly at 5-30mum pitches and by connecting those curved surfaces by a curved surface with a radius of curvature differing in sign from them. CONSTITUTION:The figure shows an interferometer forming a focal plate composed of a laser luminous flux 1, beam expander systems 2 and 3, a lens holder 4 holding three lenses 51-53, and three real spot light sources 61-63 generated by three convex lenses. A plane determined by three points of the real spot light sources 61-63 coincides with the focal plane of a lens 7, which emits three parallel luminous fluxes 81-83 to an optical recording material 9. The interval between the lenses 2 and 3 is adjusted so that irradiation areas of a photosensitive material surface irradiated with those three parallel luminous fluxes overlaps with one another as an area 10. Interference franges among three luminous fluxes are generated at a part 10 where expanded luminous fluxes 81-83 from respective light sources overlap.

Inventors

• 👤 Takashi Suzuki
• 👤 Kiyoshi Iizuka
• 👤 Keiji Otaka
• 👤 Hidemasa Mizutani

Bibliographic Details