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EP0747737A1 Expired / Lapsed EP ⏱️ 0.0 years remaining

Curved fiber optical plate

Assignee: Hamamatsu Photonics KK
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Filing: 1996-06-04
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Granted: —
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Expires: 2016-06-04
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Abstract

Abstract The present invention provides a fiber optical plate which is unitedly formed by a plurality of optical fibers bundled together and comprises (i) an input end surface (2) which is inclined with respect to the center axis of the plurality of optical fibers by an angle at which incident light from within air is prevented from being totally reflected by an interface between a core portion and a clad portion of the plurality of optical fibers; (ii) an output end surface (33) which outputs, of light incident on the input end surface from an object (e.g. a fingerprint) in contact with the input end surface, a light component arriving there after being transmitted through the plurality of optical fibers; and (iii) a curved section (20a) for adjusting the positional relationship between the input end surface and the output end surface, which is formed as the center axis of the optical fibers is curved like an arc. Accordingly, the output end surface is positioned close to the input end surface along the normal direction of the input end surface.

Inventors

  • 👤 Takeo Sugawara
  • 👤 Tsutomu Nagai
  • 👤 Toshihiko Hino

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-10-28 18:19
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/117; A61B5/1171; A61B5/1172; G; G02; G02B; G02B6/00; G02B6/04; G02B6/06; G02B6/08; G06; G06V; G06V40/00; G06V40/10; G06V40/12; G06V40/13; G06V40/1324

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 148 words
A fiber optical plate which is unitedly formed by a plurality of optical fibers bundled together, said fiber optical plate comprising: an input end surface which is inclined with respect to a center axis of said plurality of optical fibers by an angle at which incident light from within air is prevented from being totally reflected by an interface between a core portion and a clad portion of said plurality of optical fibers; an output end surface which outputs, of light incident on said input end surface from an object in contact with said input end surface, a light component arriving there after being transmitted through said plurality of optical fibers; and a curved section for adjusting a positional relationship between said input end surface and said output end surface, said curved section being formed as a center axis of said optical fibers is curved like an arc.
Claim 2
Dependent Claim 55 words
A fiber optical plate according to claim 1, wherein said curved portion renders a curvature, which corresponds to the angle of inclination of said input end surface, to the center axis of said plurality of optical fibers such that said input end surface and said output end surface are positioned substantially orthogonal to each other.
Claim 3
Dependent Claim 94 words
A fiber optical plate according to claim 1, wherein the angle of inclination of said input end surface is set such that a light-receiving angle 0° is generated for said plurality of optical fibers based on a critical angle of reflection at which light incident on said clad portion from said core portion within said plurality of optical fibers is subjected to total reflection and a critical angle of refraction generated by light incident on said core portion of said plurality of optical fibers from within the air at an incident angle of 90°.
Claim 4
Dependent Claim 41 words
A fiber optical plate according to claim 1, wherein said plurality of optical fibers include an optical absorber which covers an outer periphery of said clad portion and is made of a material for absorbing light leaking from said clad portion.
Claim 5
Dependent Claim 62 words
A fiber optical plate according to claim 1, wherein said plurality of optical fibers are formed by a plurality of units successively fixed along a light advancing direction and wherein said plurality of units include a slant unit constituting said input end surface and a curved unit which is optically coupled to said slant unit so as to constitute said curved section.
Claim 6
Dependent Claim 56 words
A fiber optical plate according to claim 1, wherein said plurality of optical fibers are formed by a plurality of channels arranged and fixed along a direction perpendicular to a light advancing direction and wherein said plurality of channels respectively have input end surfaces which are arranged so as to shift in parallel to each other.
Claim 7
Dependent Claim 41 words
A fiber optical plate according to claim 1, further comprising a contracted section which is formed between said curved section and said output end surface and has a diameter which becomes smaller from said curved portion toward said output end surface.
Claim 8
Dependent Claim 80 words
A fiber optical plate according to claim 7, wherein said plurality of optical fibers are formed by a plurality of units successively fixed along a light advancing direction and wherein said plurality of units include a slant unit constituting said input end surface, a curved unit which is optically coupled to said slant unit so as to constitute said curved section, and a tapered unit which is optically coupled to said curved unit so as to constitute said contracted section.

References Cited (Backward Citations)

US3402000A Cited
US3874783A Cited
US4932776A Cited
DE4404918A1 Cited

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