US 5,177,802 A · Fingerprint input apparatus

Abstract

A fingerprint input apparatus is constructed to have simple construction. It serves to provide an excellen S/N ratio and reliably input a fingerprint pattern. The fingerprint input apparatus includes a light source for emitting a ray of light, a lightguide plate having a predetermined location at which a finger can be contact with the lightguide plate, a unit for directing the ray of light into at least one surfaces of the lightguide plate in a manner to keep such an angle of incidence as allowing the ray of light to be totally reflected within the lightguide plate, the lightguide plate being constructed to direct the ray of light into the predetermined location, and an image pickup unit located near the predetermined location of the lightside plate and outside of an opposite surface to a surface having the predetermined location, the image pickup unit being constructed to pick up a right irregularly reflected on a fingerprint surface of the finger contacted with the predetermined location.

Claims22

Dependent claims

A fingerprint input apparatus comprising:

a lightguide plate having a through hole on which a finger is placed;
light sources for emitting rays of light;
means for directing said rays of light into surfaces of said lightguide plate in a manner to keep such an angle of incidence as allowing said rays of light to be totally reflected within said lightguide plate, said lightguide plate being constructed to guide said rays of light to said through hole and to said finger;
and
an image pickup means located in opposition to said finger through said through hole therebetween, and said image pickup means being constructed to pick up light rays reflected from said finger placed on the through hole.

2 more elements

A fingerprint input apparatus comprising:

at least one light source for emitting a ray of light;
a lightguide plate having a plurality of surfaces including a light-incident surface whereupon the ray of light is incident, a surface opposite the light-incident surface, a surface having a predetermined contact location provided thereon, and a surface opposite the surface having the predetermined contact location, the predetermined contact location being provided for a finger to be in contact therewith, the lightguide plate being constructed to totally reflect the light ray at least twice in the plate and to guide the ray of light within said lightguide plate into said predetermined contact location, the surface opposite the light-incident surface, the surface having the predetermined contact location provided thereon, and the surface opposite the surface having the predetermined contact location being formed by mirrors;
and
an image pickup means located near said predetermined contact location of said lightguide plate and outside the surface which is opposite the surface having the predetermined contact location, said image pickup means being constructed to pick up light irregularly reflected from a fingerprint surface of the finger contacted with said predetermined contact location.

1 more element

Dependencies are inferred from the claim text.

Fingerprint input apparatus

Life of this patent

Fingerprint input apparatus

Life of this patent

Abstract

Claims22