초록 ▼

The present invention relates to an image input apparatus comprising a fiber optic plate and a light source for illuminating an entrance surface of the fiber optic plate. In order to obtain a vivid image, the image input apparatus according to the present invention comprises a specific structure for

The present invention relates to an image input apparatus comprising a fiber optic plate and a light source for illuminating an entrance surface of the fiber optic plate. In order to obtain a vivid image, the image input apparatus according to the present invention comprises a specific structure for holding the light source at a predetermined position such that a luminous flux from the light source is made incident on the entrance surface of the fiber optic plate from a direction deviating from an angle region by which stray light can be incident on the entrance surface.

대표청구항 ▼

[ What is claimed is:] [1.] An image input apparatus comprising:a first fiber optic plate in which a plurality of optical fibers are bundled together, said first fiber optic plate having an entrance surface inclined with respect to an optical axis of said each optical fiber by a predetermined slant

[ What is claimed is:] [1.] An image input apparatus comprising:a first fiber optic plate in which a plurality of optical fibers are bundled together, said first fiber optic plate having an entrance surface inclined with respect to an optical axis of said each optical fiber by a predetermined slant angle .theta..sub.0 and an exit surface opposing said entrance surface;a light source for illuminating said entrance surface; anda holding member for holding said light source at a predetermined position, said holding member holding said light source in a state where, of incident angle components formed between a luminous flux emitted from said light source and said entrance surface, a vertical incident angle component .theta..sub.V on a plane orthogonal to a reference end on said entrance surface, said reference end defining said slant angle .theta..sub.V, is set to a range deviating from a range of stray light admissible angle X given by the following expression: EQU (X.sub.C -.THETA.).ltoreq.X.ltoreq.(X.sub.C +.THETA.) rein:X.sub.C is a stray light admissible center angle given by an expression (90.degree.-sin.sup.-1 (n.sub.core .multidot.sin(90.degree.-3.theta..sub.0)));n.sub.core is a refractive index of a core in said each optical fiber;.theta..sub.0 is the slant angle;.THETA. is a total reflection critical angle in the air given by an expression (sin.sup.-1 (n.sub.core .multidot.sin(90.degree.-S.sub.C -.phi.)));S.sub.C is a stray light admissible center angle in said each optical fiber given by an expression (sin.sup.-1 ((1/n.sub.core).multidot.sin X.sub.C));.phi. is a total reflection critical angle in said each optical fiber given by an expression (sin.sup.-1 (n.sub.clad /n.sub.core)); andn.sub.clad is a refractive index of a cladding in said each optical fiber.