Optics: measuring and testing – Document pattern analysis or verification
Reexamination Certificate
1998-08-03
2001-10-30
Evans, F. L. (Department: 2877)
Optics: measuring and testing
Document pattern analysis or verification
C250S556000, C382S124000, C257S436000
Reexamination Certificate
active
06310683
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a reading apparatus for reading the shape or position of a recess or projection of a target object having a fine recess or projection such as a valley or ridge of a fingertip.
A structure described in Jpn. Pat. Appln. KOKAI Publication No. 6-325158 is conventionally known as a reading apparatus for reading the shapes or positions of fine recesses or projections such as valleys or ridges of a fingertip. As shown in
FIG. 16
, this apparatus has a two-dimensional photosensor
2
disposed on a surface of a light source or an illuminant
1
. An optical fiber bundle plate
3
having a bundle of a plurality of optical fibers
3
a
is formed on the two-dimensional photosensor
2
. A light-reflecting plate
4
is disposed on the optical fiber bundle plate
3
. The two-dimensional photosensor
2
has a light-shielding plate
2
c
having an openings
2
b
on a transparent substrate
2
a
. Sensor portions
2
d
are formed on the light-shielding plate
2
c
. The light-reflecting plate
4
is made of a transparent material sheet and has a plurality of V-grooves
4
b
on each of which a light-reflecting-layer
4
a
made of an aluminum or the like is deposited. A portion between the two adjacent V-grooves
4
b
is constituted by a projection
4
d
having a flat upper surface
4
c
and a substantially trapezoidal section.
Almost all the components of this reading apparatus are flat to obtain a low-profile structure. As indicated by arrows in
FIG. 16
, parallel light beams are emitted vertically from the upper surface of the surface illuminant
1
and transmitted to the upper surfaces
4
c
of the light-reflecting plate
4
through the openings
2
b
of the two-dimensional photosensor
2
and optical fibers
3
a
of the optical fiber bundle plate
3
. The transmitted light beams are reflected by the light-reflecting layers
4
a
on the V-grooves
4
b
of the light-reflecting plate
4
. These reflected light beams come into the adjacent optical fibers
3
a
other than the light-transmitting portion (optical fiber
3
a
) of the optical fiber bundle plate
3
and are incident on the sensor portions
2
d
of the two-dimensional photosensor
2
. In this case, the beams are reflected by the upper surfaces
4
c
of the projections
4
d
of the light-reflecting plate
4
which correspond to the recesses (valleys) of the fingertip, and the beams are absorbed at the upper surfaces
4
c
which contact to the projections (ridges) of the fingertip. Therefore, an image having bright and dark portions optically emphasized in correspondence with the recesses and projections of the fingertip, thereby reading the fingerprint.
In the conventional reading apparatus of this type, the parallel beams are emitted vertically from the upper surface of the surface illuminant
1
and transmitted to the upper surface of the light-reflecting plate
4
through the openings
2
b
of the two-dimensional photosensor
2
and the optical fibers
3
a
of the optical fiber bundle plate
3
. The light beams reflected by the upper surfaces
4
c
of the projections
4
d
of the light-reflecting plate
4
are reflected by the light-reflecting layer
4
a
of the V-grooves
4
b
of the light-reflecting plate
4
and come into the adjacent optical fibers
3
a
other than the optical fiber
3
a
having undergone transmission. The incident angle at the optical fiber
3
a
having a small light reception angle increases to result in a large loss. This makes it difficult to obtain a sufficiently high contrast. In addition, to make the light beams reflected by the upper surfaces
4
c
of the projections
4
d
of the light-reflecting plate
4
come into the optical fibers
3
a
of the optical fiber bundle plate
3
which are located at the predetermined positions and strike the sensor portions
2
d
of the two-dimensional photosensor
2
which are located at the predetermined positions in a prescribed manner, the projections
4
d
of the light-reflecting plate
4
, the optical fibers
3
a
of the optical fiber bundle plate
3
, and the sensor portions
2
d
of the two-dimensional photosensor
2
must be accurately positioned in a one-to-one correspondence, resulting in a low productivity and a high cost.
BRIEF SUMMARY OF THE INVENTION
It is an object of the present invention to provide an apparatus capable of reducing an optical loss in reading a fingerprint or the like, eliminating positioning among the respective components, and improving the productivity.
According to the present invention, there is provided a reading apparatus comprising:
a light source;
a photosensor having a transparent base layer formed on the light source, the photosensor having a plurality of photosensor portions formed on the base layer and a resin layer covering the photosensor portions; and
a scattering reflection layer formed on the photosensor,
wherein light emitted by the light source and scattered and reflected by the scattering reflection layer is incident on each photosensor portion.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.
REFERENCES:
patent: 4336998 (1982-06-01), Ruell
patent: 5446290 (1995-08-01), Fujieda et al.
patent: 5448649 (1995-09-01), Chen et al.
patent: 5461419 (1995-10-01), Yamada
patent: 5463420 (1995-10-01), Yamada
patent: 5708497 (1998-01-01), Fujieda
patent: 6150665 (2000-11-01), Suga
patent: 0 609 812 A (1994-08-01), None
patent: 6-325158 (1994-11-01), None
patent: WO 97/14111 (1997-04-01), None
Patent Abstracts of Japan, vol. 1997, No. 09, Sep. 30, 1997, Abstract of JP 09 116128 A, May 2, 1997.
Patent Abstracts of Japan, vol. 013, No. 460, Oct. 18, 1989, Abstract of JP 01 179937 A, Jul. 18, 1989.
Fujiwara Minoru
Ishii Hiromitsu
Muto Tetsuo
Sasaki Makoto
Casio Computer Co. Ltd.
Evans F. L.
Frishauf, Holtz Goodman, Langer & Chick, P.C.
Smith Zandra V.
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