Fingerprint input apparatus

• US 7,177,451 B2
• Filed: 09/07/2004
• Issued: 02/13/2007
• Est. Priority Date: 02/03/1999
• Status: Expired due to Term

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Higuchi, Teruyuki
• Primary Examiner(s): Bali; Vikkram
• Application Number:
  US10/934,476
• Publication Number:
  US 20050025346A1
• Time in Patent Office: 889 Days
• Field of Search: 382115-116, 382124-127, 356/71, 340/5.53, 340/5.83
• US Class Current: 382/124
• CPC Class Codes: G06V 40/1318 using electro-optical elements or layers, e.g. electroluminescent sensing
• CPC Class Codes: G06V 40/1341 Sensing with light passing through the finger
• CPC Class Codes: G06V 40/1347 Preprocessing; Feature extraction
• CPC Class Codes: G06V 40/14 Vascular patterns

Abstract

A fingerprint input apparatus includes scattered light and a two-dimensional image sensor. The scattered light is generated inside a finger having a fingerprint pattern in accordance with external light. The fingerprint pattern is made up of a ridge portion and a valley portion. The two-dimensional image sensor is made of a large number of light-receiving elements arranged in a two-dimensional array. The image of the fingerprint pattern is input to a light-receiving surface of the light-receiving element. The light-receiving element whose light-receiving surface is in substantially contact with the ridge portion detects as the ridge portion a bright portion where the scattered light emerging from the finger reaches at a high intensity. The light-receiving element whose light-receiving surface corresponds to the valley portion via a space detects as the valley portion a dark portion where the scattering light emerging from the finger reaches at a low intensity.

Claims

1. An imaging sensor adapted to generate an electrical signal representing and image of a skin surface of a finger, said image sensor comprising:

a transparent cover having first and second surfaces; and

a plurality of light responsive elements arranged under said second surface of said cover, when said first surface of said cover is in contact with said skin surface of said finger, said light responsive elements being responsive only to light directly emerging from an inside of said finger through said cover to generate said electrical signal representing said image of said skin surface of a finger.

2. An image sensor adapted to generate an electrical signal representing an image of a skin surface of a finger, said image sensor comprising a plurality of light responsive elements, at least one of which is disposed between a ridge and a valley of a fingerprint, light from outside said finger entering said finger and emerging from said finger as scattered light, said plurality of light responsive elements generating said electrical signal representing an image of a skin surface of a finger only from scattered light directly emerging from an inside of said finger and not reflected light from outside of said finger.

3. An image sensor adapted to generate an electrical signal representing an image of a skin surface of a finger, said image sensor comprising:

a transparent cover having first and second surfaces; and

a plurality of light responsive elements arranged under said second surface of said cover, when said first surface of said cover is in contact with said skin surface of said finger, said plurality of light responsive elements generating said electrical signal representing an image of a skin surface of a finger from scattered light directly emerging from an inside of said finger without a light source under said transparent cover.

4. An image sensor adapted to generate an electrical signal representing an image of a skin surface of a finger, said image sensor comprising:

a transparent cover having first and second surfaces; and

a plurality of light responsive elements arranged under said second surface of said cover, when said first surface of said cover is in contact with said skin surface of said finger, said plurality of light responsive elements generating said electrical signal representing an image of a skin surface of a finger from scattered light directly emerging from an inside of said finger without a light source irradiating said skin surface in contact with said cover.

5. An imaging sensor adapted to generate an electrical signal representing and image of a skin surface of a finger, said image sensor comprising:

a transparent cover having first and second surfaces; and

a plurality of light responsive elements arranged under said second surface of said cover, when said first surface of said cover is in contact with said skin surface of said finger, said light responsive elements being responsive to light directly emerging from an inside of said finger through said cover to generate said electrical signal representing said image of said skin surface of a finger,

wherein no optical component is interposed between said transparent cover and said plurality of light responsive elements.

6. An image sensor adapted to generate an electrical signal representing an image of a skin surface of a finger, said image sensor comprising:

a transparent cover having first and second surfaces; and

a plurality of light responsive elements arranged under said second surface of said cover, when said first surface of said cover is in contact with said skin surface of said finger, said plurality of light responsive elements generating said electrical signal representing an image of a skin surface of a finger from scattered light directly emerging from an inside of said finger,

wherein no optical component is interposed between said transparent cover and said plurality of light responsive elements.

7. A fingerprint input apparatus for inputting a fingerprint of a tip of a finger having ridge and valley portions, said fingerprint input apparatus comprising:

a number of light receiving elements arranged in a two-dimensional matrix; and

a transparent cover that protects a light receiving surface of said light receiving elements,

wherein when a finger is placed on said transparent cover, and wherein no dedicated light source is required, a bright area is detected as a ridge portion, said bright area is such an area which a diffusion light sufficiently reaches from an inside of a finger via said ridge portion, said bright area is detected by a light receiving element having a light receiving surface close to said ridge portion, and

a dark area is detected as a valley portion, said dark area is such an area which a diffusion light hardly reaches from an inside of a finger, and said dark area is detected by a light receiving element having a light receiving surface close to said valley portion.