Irregular pattern input device comprising an optical fiber bundle

• US 5,426,296 A
• Filed: 02/01/1994
• Issued: 06/20/1995
• Est. Priority Date: 02/17/1993
• Status: Expired due to Term

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Nakajima, Hajime, Takashima, Kazuo, Shikai, Masahiro
• Primary Examiner(s): Nelms, David C.
• Assistant Examiner(s): Lee, John R.
• Application Number:
  US08/190,786
• Time in Patent Office: 504 Days
• Field of Search: 250/227.28, 250/227.29, 250/227.20, 250/227.24, 250/227.11, 250/556, 356/71, 356/73, 382/4, 382/5, 382/2
• US Class Current: 250/227.2
• CPC Class Codes: G06V 40/1324 by using geometrical optics, e.g. using prisms G06V40/1312 takes precedence
• CPC Class Codes: G07C 9/37 using biometric data, e.g. fingerprints, iris scans or voice recognition

Abstract

An irregular pattern input device includes an optical fiber bundle in which an entrance surface and an exit surface are respectively formed at both ends thereof. Lighting means emits irradiation light so as to provide a light pattern according to a convex portion of a subject in contact with the entrance surface, and according to a concave portion of the subject in no contact with the entrance surface. In this case, an angle of incidence of the irradiation light is set to be larger than a critical angle on an interface between a core portion of each optical fiber of the optical fiber bundle and the air. It is thereby possible to provide total reflection on the entrance surface in no contact with the concave portion of the subject, and non-total reflection on the entrance surface in contact with the convex portion of the subject, resulting in reflected light having a light pattern according to an irregular pattern. The resultant light pattern is inputted into photoelectric transforming means through the exit surface, and is transformed into electric information by the photoelectric transforming means.

Claims

1. An irregular pattern input device comprising:

an optical fiber bundle formed by bundling a plurality of optical fibers to have an entrance surface and an exit surface formed at both ends of said bundled optical fibers;

lighting means for emitting irradiation light to said entrance surface so as to provide a light pattern having each different amount of reflected light at said entrance surface in contact with a convex portion of a subject and at said entrance surface in no contact with a concave portion of said subject; and

photoelectric transforming means, into which said obtained light pattern is inputted through said exit surface of said optical fiber bundle, for transforming said inputted light pattern into electric information,

wherein a half mirror is provided on the side of said exit surface of an optical fiber bundle, and irradiation light emitted from said lighting means being reflected from said half mirror to be introduced into said entrance surface through said exit surface, and passing through said half mirror to be input into photoelectric transforming means.

2. An irregular pattern input device according to claim 1, wherein a shielding member is disposed around said subject, or around said subject and lighting means.

3. An irregular pattern input device according to claim 1, wherein irradiation light emitted from said lighting means has a wavelength in a particular range, and a filter being interposed between said entrance surface of said optical fiber bundle and photoelectric transforming means to pass only light having said wavelength in said particular range.

4. An irregular pattern input device according to claim 1, wherein said lighting means includes equalizing means for providing a uniform intensity distribution of irradiation light on said entrance surface of said optical fiber bundle.

5. An irregular pattern input device according to claim 1, wherein said optical fiber bundle includes a

plurality of separated entrance surfaces, and one exit surface.

6. An irregular pattern input device comprising:

an optical fiber bundle formed by bundling a plurality of optical fibers to have an entrance surface and an exit surface formed at both ends of said bundled optical fibers;

lighting means for emitting irradiation light to said entrance surface so as to provide a light pattern having each different amount of reflected light at said entrance surface in contact with a convex portion of a subject and at said entrance surface in no contact with a concave portion of said subject; and

photoelectric transforming means, into which said obtained light pattern is inputted through said exit surface of said optical fiber bundle, for transforming said inputted light pattern into electric information,

wherein an entrance surface of an optical fiber bundle is inclined by a predetermined angle with respect to an axis of an optical fiber, and lighting means emitting irradiation light to enter said entrance surface at an angle of incidence larger than a critical angle on an interface between said optical fiber and air so as to provide a light pattern which is not totally reflected from said entrance surface in contact with a convex portion of a subject, and is totally reflected from said entrance surface in no contact with a concave portion of said subject, and emitting irradiation light having an angle of incidence which meets a constant relation with respect to a tilt angle of said entrance surface of said optical fiber bundle such that said light pattern is propagated through said optical fiber bundle to said exit surface.

7. An irregular pattern input device according to claim 6, wherein a shielding member is disposed around said subject, or around said subject and said lighting means.

8. An irregular pattern input device according to claim 6, wherein irradiation light emitted from said lighting means has a wavelength in a particular range, and a filter being interposed between said entrance surface of said optical fiber bundle and photoelectric transforming means to pass only light having said wavelength in said particular range.

9. An irregular pattern input device according to claim 6, wherein said lighting means includes equalizing means for providing a uniform intensity distribution of irradiation light on said entrance surface of said optical fiber bundle.

10. An irregular pattern input device according to claim 6, wherein a material to absorb light is interposed between bundled optical fibers at least in one portion of said optical fiber bundle other than a partial optical fiber bundle through which irradiation light emitted by lighting means passes before reaching an entrance surface of said optical fiber bundle.

11. An irregular pattern input device according to claim 6, wherein said optical fiber bundle includes a plurality of separated entrance surfaces, and one exit surface.

12. An irregular pattern input device comprising:

an optical fiber bundle formed by bundling a plurality of optical fibers to have an entrance surface and an exit surface formed at both ends of said bundled optical fibers;

lighting means for emitting irradiation light to said entrance surface so as to provide a light pattern having each different amount of reflected light at said entrance surface in contact with a convex portion of a subject and at said entrance surface in no contact with a concave portion of said subject; and

photoelectric transforming means, into which said obtained light pattern is inputted through said exit surface of said optical fiber bundle, for transforming said inputted light pattern into electric information,

wherein an entrance surface of an optical fiber bundle is inclined by a predetermined angle with respect to an axis of an optical fiber, and said lighting means emitting irradiation light at an angle of incidence which meets a constant relation with respect to a tilt angle of said entrance surface of said optical fiber bundle in order to prevent light regularly reflected from said entrance surface in contact with a convex portion of a subject from being propagated to an exit surface and to propagate diffuse reflection light to said exit surface, and in order to prevent light regularly reflected from said entrance surface in no contact with a concave portion of said subject, or light entering said entrance surface from said concave portion through air from being propagated to said exit surface so as to obtain a light pattern according to irregularity of said subject.

13. An irregular pattern input device according to claim 12, wherein a shielding member is disposed around said subject, or around said subject and said lighting means.

14. An irregular pattern input device according to claim 12, wherein irradiation light emitted from said lighting means has a wavelength in a particular range, and a filter being interposed between said entrance surface of said optical fiber bundle and photoelectric transforming means to pass only light having said wavelength in said particular range.

15. An irregular pattern input device according to claim 12, wherein said lighting means includes equalizing means for providing a uniform intensity distribution of irradiation light on said entrance surface of said optical fiber bundle.

16. An irregular pattern input device according to claim 12, wherein a material to absorb light:

is interposed between bundled optical fibers at least in one portion of said optical fiber bundle other than a partial optical fiber bundle through which irradiation light emitted by lighting means passes before reaching an entrance surface of said optical fiber bundle.

17. An irregular pattern input device according to claim 12, wherein said optical fiber bundle includes a plurality of separated entrance surfaces, and one exit surface.

18. An irregular pattern input device comprising:

an optical fiber bundle formed by bundling a plurality of optical fibers to have an entrance surface and an exit surface formed at both ends of said bundled optical fibers;

lighting means for emitting irradiation light to said entrance surface so as to provide a light pattern having each different amount of reflected light at said entrance surface in contact with a convex portion of a subject and at said entrance surface in no contact with a concave portion of said subject; and

photoelectric transforming means, into which said obtained light pattern is inputted through said exit surface of said optical fiber bundle, for transforming said inputted light pattern into electric information,

wherein an entrance surface of an optical fiber bundle is inclined by a predetermined angle with respect to an axis of said optical fiber, and said lighting means being set such that a constant relation can be satisfied between a critical angle on an interface between said optical fiber and air and a tilt angle of said entrance surface so as to provide a light pattern according to irregularity of said subject by propagating diffused light of said irradiation light entering said entrance surface in contact with a convex portion of said subject through said convex portion thereof to an exit surface, and preventing diffused light of said irradiation light entering said entrance surface in no contact with a concave portion of said subject through said concave portion thereof and the air from being propagated to said exit surface.

19. An irregular pattern input device according to claim 18, wherein a shielding member is disposed around said subject, or around said subject and lighting means.

20. An irregular pattern input device according to claim 18, wherein irradiation light emitted from said lighting means has a wavelength in a particular range, and a filter being interposed between said entrance surface of said optical fiber bundle and photoelectric transforming means to pass only light having said wavelength in said particular range.

21. An irregular pattern input device according to claim 18, wherein said optical fiber bundle includes a plurality of separated entrance surfaces, and one exit surface.

22. An irregular pattern input device comprising:

an optical fiber bundle formed by bundling a plurality of optical fibers, and including an entrance surface and an exit surface formed at both ends of said optical fiber bundle;

lighting means including a light waveguide mounted on said entrance surface of said optical fiber bundle and a light source to introduce light into said light waveguide for propagating said light through said waveguide so as to emit irradiation light to a subject mounted on a waveguide path; and

photoelectric transforming means into which a light pattern according to a convex portion and a concave portion of said subject provided by said lighting means is inputted through said exit surface of said optical fiber bundle, for transforming said input light pattern into electric information.

23. An irregular pattern input device according to claim 22, wherein a shielding member is disposed around said subject, or around said subject and lighting means.

24. An irregular pattern input device according to claim 22, wherein irradiation light emitted from said lighting means has a wavelength in a particular range, and a filter being interposed between said entrance surface of said optical fiber bundle and photoelectric transforming means to pass only light having said wavelength in said particular range.

25. An irregular pattern input device according to claims 22, wherein said optical fiber bundle includes a plurality of separated entrance surfaces, and one exit surface.