Fingerprint input apparatus

• US 6,463,166 B1
• Filed: 09/05/2000
• Issued: 10/08/2002
• Est. Priority Date: 12/06/1996
• Status: Expired due to Fees

• Current Assignee: Yamatake-Honeywell Company Limited
• Original Assignee: Yamatake-Honeywell Company Limited
• Inventors: Fujiwara, Hisatoshi
• Primary Examiner(s): MEHTA, BHAVESH M
• Application Number:
  US09/655,155
• Time in Patent Office: 763 Days
• Field of Search: 382/115, 382/124-127, 356/71
• US Class Current: 382/127
• CPC Class Codes: G06V 40/1324 by using geometrical optics, e.g. using prisms G06V40/1312 takes precedence

Abstract

A fingerprint input apparatus includes a prism, a light source, a pinhole, and an imaging plane. The prism is placed such that a surface in one direction serves as a fingerprint collection surface. The light source irradiates light on the fingerprint collection surface through the prism. The pinhole is set in the path of light which is reflected by the pattern surface of a finger placed on the fingerprint collection surface and emerges from the prism. The light emerging from the prism and passing through the pinhole is formed into an image on the imaging plane. When the prism is substituted by air, an optical fingerprint collection surface equivalent to the fingerprint collection surface is set to be substantially parallel to the imaging plane.

Claims

1. A fingerprint input apparatus comprising:

a first prism placed such that a surface in one direction serves as a fingerprint collection surface;

a light source for irradiating light on the fingerprint collection surface through said first prism;

a pinhole set in a path of light which is reflected by a pattern surface of a finger placed on said fingerprint collection surface and emerges from said first prism;

an imaging plane on which the light emerging from said first prism and passing through said pinhole is formed into an image; and

a second prism placed in front of said imaging plane,

wherein the fingerprint collection surface of said first prism is set to be substantially parallel to said imaging plane, the fingerprint collection surface of said first prism is set to be substantially parallel to a surface of said second prism on the imaging plane side, and an exit surface of said first prism with respect to said pinhole is set to be substantially parallel to an incident surface of said second prism with respect to said pinhole.

2. A fingerprint input apparatus comprising:

a prism placed such that a surface in one direction serves as a fingerprint collection surface;

a light source for irradiating light on the fingerprint collection surface through said prism;

a pinhole set in a path of light which is reflected by a pattern surface of a finger placed on said fingerprint collection surface and emerges from said prism;

a lens placed close to a rear side of said pinhole; and

an imaging plane on which the light emerging from said prism and passing through said pinhole and said lens is formed into an image,

wherein when a straight line connecting a center of the fingerprint collection surface and a center of said imaging plane is an optical axis, said imaging plane is inclined with respect to the optical axis to prevent a blur, and a central axis of said lens is inclined with respect to the optical axis to prevent trapezoidal distortion.