Biometric Sensing

• US 20130279769A1
• Filed: 04/10/2013
• Published: 10/24/2013
• Est. Priority Date: 04/10/2012
• Status: Abandoned Application

• Current Assignee: Idex ASA
• Original Assignee: Picofield Technologies, Inc.
• Inventors: Benkley, Fred G. III, Geoffroy, David Joseph
• Application Number:
  US13/860,494
• Publication Number:
  US 20130279769A1
• Time in Patent Office: Days
• US Class Current: 382/124
• CPC Class Codes: G06F 2203/0338 Fingerprint track pad, i.e. fingerprint sensor used as pointing device tracking the fingertip image
• CPC Class Codes: G06F 3/03547 Touch pads, in which fingers can move on a surface
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/041661 using detection at multiple resolutions, e.g. coarse and fine scanning; using detection within a limited area, e.g. object tracking window
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• CPC Class Codes: G06T 7/73 using feature-based methods
• CPC Class Codes: G06V 40/1306 non-optical, e.g. ultrasonic or capacitive sensing
• CPC Class Codes: G06V 40/1335 Combining adjacent partial images (e.g. slices) to create a composite input or reference pattern; Tracking a sweeping finger movement
• CPC Class Codes: G06V 40/1376 Matching features related to ridge properties or fingerprint texture
• CPC Class Codes: H10K 59/40 OLEDs integrated with touch screens

Abstract

An novel sensor is provided having a plurality of substantially parallel drive lines configured to transmit a signal into a surface of a proximally located object, and also a plurality of substantially parallel pickup lines oriented proximate the drive lines and electrically separated from the pickup lines to form intrinsic electrode pairs that are impedance sensitive at each of the drive and pickup proximal locations.

Claims

1. An impedance sensor, comprising:

a plurality of substantially parallel drive lines configured to transmit a signal to a proximally located object; and

a plurality of substantially parallel pickup lines configured to receive a resultant signal and oriented substantially perpendicular to the drive lines and physically separated from the pickup lines on a different layer by a substantially incompressible dielectric located between the drive lines and pickup lines to form a two dimensional array of intrinsic electrode pairs that are impedance sensitive to detect ridge and valley features of a proximally located finger when driven by circuitry located outside the sensing area which is connected to each drive and pickup line of the array in order to activate one or more junctions formed at individual dive and pickup line crossovers where the circuitry compromises a driver or drive multiplexor connected to each drive line, and buffer, switch or input multiplexor attached to each pickup line, and at least one differencing amplifier configured to receive it'"'"'s inputs from the input buffers or input multiplexor where a signal proportional to impedance about each drive line and pickup crossover location can be differenced with a signal proportional to impedance about another drive line and pickup crossover location to differentiate impedance values in order to determine relative object proximity.