U.S. patent application number 16/225278 was filed with the patent office on 2019-04-25 for optical coherence tomography array based subdermal imaging device.
The applicant listed for this patent is Joshua Noel Hogan. Invention is credited to Joshua Noel Hogan.
Application Number | 20190122118 16/225278 |
Document ID | / |
Family ID | 58634848 |
Filed Date | 2019-04-25 |
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United States Patent
Application |
20190122118 |
Kind Code |
A1 |
Hogan; Joshua Noel |
April 25, 2019 |
Optical coherence tomography array based subdermal imaging
device
Abstract
The invention teaches a multiple reference optical coherence
tomography scanner that provides a subdermal fingerprint scan,
covers an area of approximately 16 mm-17 mm.times.10 mm in less
than a second, and fits into a slim profile of less than 6 mm in
thickness, thereby fitting within the slim consumer electronics
such as the iPhone and similar consumer electronics. Various
embodiments are taught.
Inventors: |
Hogan; Joshua Noel; (Los
Altos, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hogan; Joshua Noel |
Los Altos |
CA |
US |
|
|
Family ID: |
58634848 |
Appl. No.: |
16/225278 |
Filed: |
December 19, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15851258 |
Dec 21, 2017 |
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16225278 |
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15339683 |
Oct 31, 2016 |
9892334 |
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15851258 |
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62267241 |
Dec 14, 2015 |
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62249309 |
Nov 1, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01B 9/02091 20130101;
G06K 9/0004 20130101; G06N 3/084 20130101; G06N 3/04 20130101; G06K
2009/00932 20130101; G06K 9/00046 20130101; G06K 9/00885
20130101 |
International
Class: |
G06N 3/08 20060101
G06N003/08; G06N 3/04 20060101 G06N003/04 |
Claims
7-11. (allowed)
12. A combined OCT and camera system comprised of an OCT system
with an array of optical sources and a long beam splitter at least
one actuator that translates the OCT system in a lateral direction
thereby acquiring multiple depth scans of a target, and a target
contact surface on which said target is placed and along which
light is directed by means of total internal reflection, and a
camera which detects light scattered due to frustrated total
internal reflection, where such frustration of total internal
reflection is due to target contact with said target contact
surface, where said camera is transparent at the wavelength of said
OCT system and where the OCT probe beam is directed through said
transparent camera. and OCT depth scans and an image of the target
are acquired.
13. The system of claim 12 wherein said target is a
fingerprint.
14. The system of claim 12 wherein said array of optical sources is
an array of broad band optical sources.
15. The system of claim 14 wherein said array of optical sources is
an array of swept sources.
16. The system of claim 12 wherein said camera is fabricated using
thin film technology consisting of arrays of light detectors and
transistor arrays.
Description
GOVERNMENT FUNDING
[0001] None
FIELD OF USE
[0002] Security applications.
RELATED APPLICATIONS
[0003] This utility application, docket CI150930US_div01, is a
continuation of U.S. application Ser. No. 15/339,683, which claims
priority from U.S. provisional application 62/249,309 of the same
title, and from U.S. provisional 62/267,211 Parallel Optical Source
Device, the entirety of each of which is incorporated by reference
as if full set forth herein. The instant application is also is
related to the following US applications and patents, the
entireties of each of which are incorporated by reference as if
fully set forth herein: U.S. provisional 62/267,211 Parallel
Optical Source Device; WO/2016/109844 Reference signal filter for
interferometric system; U.S. application Ser. No. 14/975,745 A
polarized OCT system with improved SNR; U.S. application Ser. No.
14/738,919, filed Jun. 14, 2015, entitled System and Method for
Fingerprint Validation, publication US 2015-0363630 A1; U.S. Pat.
No. 7,526,329 Multiple Reference Non-invasive Analysis System; U.S.
Pat. No. 7,751,862 Frequency Resolved Imaging System.
BACKGROUND
[0004] Security is an ubiquitous concern in modern life. Many
consumer electronic devices are currently equipped with fingerprint
scanners to unlock the device. However, surface fingerprints are
fairly easy to fake. A need exists for more secure means of
preventing unauthorized access to consumer electronics. Moreover,
although more secure means do currently exist, such approaches fail
to meet consumer expectations of nearly instantaneous access to
electronic devices. Further obstacles to security arise as consumer
electronics manufacturers respond to consumer demands for smaller,
lighter devices, while simultaneously offering price reductions.
Solutions to security are rejected if such approaches do not fit
the expected form factor, or increase the selling price of the
device. Lastly, standards exist, such as those adopted by NIST, and
purveyors of security must also satisfy such standards.
[0005] For a device to be accepted by consumers, user
authentication is expected to be very secure and very fast, as well
as robust. It is expected to be nearly transparent to the user,
adding neither weight nor volume to the device, as well as being
included at no extra charge in the price of the device.
[0006] What is needed is a rapid, secure fingerprint scan device.
What is further needed is a rapid secure fingerprint scan device
that fits into the form of current electronic devices. What is also
needed is a rapid highly secure user authentication that is robust,
withstanding of consumer handling and device use conditions.
Further needed is an approach that is sufficiently low cost so that
price of the device is not increased by virtue of the included user
authentication feature.
BRIEF SUMMARY OF THE INVENTION
[0007] The invention meets at least all of the above cited unmet
needs. The invention teaches a multiple reference optical coherence
tomography scanner that provides a subdermal fingerprint scan,
covers an area of approximately 16 mm-17 mm.times.10 mm in less
than a second, and fits into a slim profile of the order of 6 mm in
thickness, thereby fitting within the slim consumer electronics
such as the iPhone and similar consumer electronics.
[0008] The scan of the area of interest is accomplished by
combining a multiple reference optical coherence tomography system
with a single reference mirror, with source arrays aligned
laterally to the left and right of the central reference mirror.
The scanning module contains reference mirror (which mirror
oscillates laterally) and a left and right beamsplitter in the path
of the radiation incoming from left and right radiation sources.
The scanning module moves laterally, along the same axis as the
oscillating reference mirror, and accomplishes an area of scan
effectively doubled by the center reference mirror. The left and
right banks of radiation sources enable scans of 17 mm along the Z
axis.
[0009] The scan rate produces a resolution that, when translated to
dpi, satisfies at least the NIST FAP10 standard for fingerprint
security. Moreover, the scan includes a subdermal fingerprint and,
consequently, is more secure than a surface fingerprint.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1A is a block diagram of a cross section of the array
based multiple reference optical coherence scanning device
according to the invention.
[0011] FIG. 1B is a perspective view of one of the pair of housings
of a plurality of sources according to the embodiment depicted in
FIG. 1A, according to the invention.
[0012] FIG. 2 depicts an interior cross section of the scanning
module, illustrating an array configuration of sources, according
to an alternate embodiment of the invention.
[0013] FIG. 3 depicts a cross section as in FIG. 2, depicting the
source array as horizontal black bands, representing linear
apertures through which the source radiation is emitted, according
to an alternate embodiment of the invention.
[0014] FIG. 4 illustrates the spacing of the sources depicted in
FIG. 1B, illustrating scan density resolution that satisfies NIST
standard FAP10 (500 dpi) in the application of fingerprint
security.
[0015] FIG. 5 depicts an alternate embodiment of the invention.
[0016] FIG. 6 depicts an alternate embodiment of the invention.
[0017] FIG. 7 depicts an alternate embodiment of the invention.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0018] The invention uses multiple reference optical coherence
tomography, (abbreviated MRO-OCT), where multiple reference
radiation reflections result in overlapping scan segments at
precise target depths. The reader may refer to Multiple Reference
Non-invasive Analysis System, U.S. Pat. No. 7,526,32 and Frequency
Resolved Imaging System, U.S. Pat. No. 7,751,862 for further
information.
[0019] In this invention, a single reference mirror is centered
between a left and right source radiation, positioned
perpendicularly above a target, and beneath a detection array. The
reference mirror is moved in an oscillatory manner by a first
actuator, and scanning is done on both the left and right side of
the mirror, and along the length of the mirror.
[0020] At a height of 2 mm, and a depth of 17 mm, and a width of
less than 5 mm, a lateral movement of the scanning module by a
second actuator, and the oscillation of the mirror generates
interference signals and produces a scanning area covering 10 mm of
the target. The second actuator, coupled to the scanning module,
thus produces the requisite width while only moving half of the
distance.
[0021] Multiple sources minimize the scanning requirement in the
perpendicular lateral direction.
[0022] At 50-micron resolution, 3000 scans cover a 10 mm.times.17
mm area in less than one second, satisfying at least the NIST FAP
10 standard for fingerprints.
[0023] In one embodiment, the invention provides a subdermal
fingerprint scan in the time it takes to briefly touch a glass pad.
Moreover, the entire scanning apparatus moves approximately only 5
mm and fits within the current size--particularly the thinnest of
popular mobile phones and devices, i.e. approximately 6 mm or
less.
[0024] It can be appreciated that this has application in unlocking
consumer electronics such as iPhones, iPads, and other consumer
electronics, in secure banking transactions, in authorizing access
to sites, automobiles, etc. and in border control.
[0025] Referring to FIG. 1A, a cross section of a preferred
embodiment is depicted, comprising
a first housing 101 of a first set of optical sources; a second
housing 121 of a second set of optical sources, where radiation 103
from said first set of sources in said first housing 105 is
directed to a scanning module 135 from one linear direction, and
radiation 123 from said second set of sources in said second
housing 121 is direct to said scanning module 135 from the opposite
direction;
[0026] The scanning module 135 contains:
[0027] a first optical beamsplitter 105 with a first beamsplitting
surface 107 and a first partially reflective surface 109 where
incoming probe radiation 103 passes through beamsplitting surface
107 to a first highly reflective surface 111 of the optic 113, said
optic 113 having a surface 111 where
[0028] said first partially reflective surface 109 is parallel to
the surface 111 of the reference optic 113 and is partially
reflective (typically approximately 80% reflective) causing
multiple reflections as taught in Multiple Reference Non-invasive
Analysis System, U.S. Pat. No. 7,526,32 and Frequency Resolved
Imaging System, U.S. Pat. No. 7,751,862;
[0029] A second optical beamsplitter 125 with a second
beamsplitting surface 127 and a second partially reflective surface
129 where incoming probe radiation 123 passes through beamsplitting
surface 127 to a second highly reflective surface 131 of the optic
113, said optic having a surface 131 where
[0030] said second partially reflective surface 129 is parallel to
the surface 131 of the optic 113 and is partially reflective
(typically approximately 80% reflective) causing multiple
reflections as taught in Multiple Reference Non-invasive Analysis
System, U.S. Pat. No. 7,526,32 and Frequency Resolved Imaging
System, U.S. Pat. No. 7,751,862. As used herein, "highly
reflective" means reflectivity equal to or greater than 95%.
[0031] Thus both the first and the second optical beamsplitters
105, 125 separate the radiation into reference radiation and probe
radiation. The reference radiation is reflected by 109 and 111, and
is directed to the detector array. Similarly for the other
side.
[0032] The probe radiation is directed to the target, where
scattered probe radiation returns through the beamsplitter to the
detector array. This occurs on both sides.
[0033] The reference optic 113 with the two highly reflective
surfaces 111, 131 is coupled to a first actuator (not shown) which
oscillates the optic--and hence the highly reflective surfaces--in
a lateral (left-right) direction. In the preferred embodiment, the
length of the optic 113 is approximately 16-17 mm.
[0034] The scanning module 135 is coupled to a second actuator (not
shown) is and capable of lateral motion, moving uniformly in a
lateral direction (along the same axis as the oscillatory motion of
the reference optic 113) for a distance of approximately 5 mm. This
accomplishes a total lateral scan of approximately 10 mm.
[0035] A two dimension (2D) detector array 133 receives optical
radiation reflected from a target 117, as well as reference
radiation from the surfaces of the reference optic and the partial
mirrors 109 and 129, creating interference signals corresponding to
depth scans of the target. This is described in detail in Multiple
Reference Non-invasive Analysis System, U.S. Pat. No. 7,526,32 and
Frequency Resolved Imaging System, U.S. Pat. No. 7,751,862.
[0036] A surface layer 115, typically glass, provides contact
surface with the target 117. The path length of one half of the
scanning module 137 is depicted, along with the complete scan
coverage range 139 according to the invention. The invention
provides for oscillatory motion of the reference optic 113, as well
as lateral movement of the scanning module 135.
[0037] The target is placed in contact with the surface layer or
glass, and during the time of contact, scans of the target are
obtained. It can be appreciated that in an embodiment where a
single pair of radiation sources are used (rather than a plurality)
the scan can be accomplished by moving the entire scanning module
in the orthogonal lateral direction for the full length. However,
scan time--the time to acquire a fingerprint--will be longer. In
such an embodiment, the detector array need only be a one
dimensional--1D--array. Alternatively, a pair of detectors could be
attached to the scanning module itself.
[0038] Referring to FIG. 1B, the preferred embodiment, which shows
a perspective of the first housing relative to the detector array,
the first housing 101 enables emission of a plurality of radiation
source beams (103 in FIG. 1A). A linear array is depicted; a
corresponding array is provided in the second housing (not shown).
The distance between the radiation beams determine the distance the
scanning module need move in the perpendicular or orthogonal
lateral direction. In FIG. 1B, the distance is 0.04 inches or
approximately 1 mm. As also illustrated in FIG. 4, the dimensions
of the aperture of the radiation source (not depicted) less than 1
mm in diameter, and the vertical dimension (height) about 5 mm and
a depth of 17 mm.
[0039] Referring now to FIG. 2, an alternate embodiment provides an
array of sources, rather than the linear source arrangement as seen
in FIG. 1B. An array further reduces the lateral scanning
requirements. FIG. 2 schematically depicts an interior cross
section of the scanning module (as viewed from the anterior surface
of the mirror), and depicts an array configuration of sources
showing: a target to be scanned 209; contact surface 208; scanning
module 210 (in FIG. 1A, 135); a two dimensional detector array 211;
a cross section view of the source 212, depicting an array of
optical radiation sources (pictured as black squares in a regular
grid arrangement). It can be appreciated that the depiction is
meant to suggest a plurality, and not intended to limit the
arrangement to regular rows and columns.
[0040] Referring now to FIG. 3, FIG. 3 is a cross section as is
FIG. 2, and depicts an alternate embodiment using line optical
sources, where an LED array, or an edge emitting LED array, is
emitting through a parallel arrangement of collimating lenses, or
any line source, where the numbered components are as follows:
target 209; contact plate 208; scanning module 210 (135 in FIG.
1A); two dimensional detector array; and a plurality of line
optical sources 312, where an LED array is emitting source
radiation through a parallel arrangement of collimating lenses.
[0041] Referring now to FIG. 4, a view of the first housing as in
FIG. 1B, details on the probe beam spacing in a preferred
embodiment illustrate how the NIST standard of 500 dpi can be
satisfied by a linear array according to the invention, with a scan
rate of 3000 scans per second. Moreover, the dimensions as set
forth in FIG. 4 illustrate the low height and narrow width,
enabling the inventive device to fit in the limited space available
in current consumer electronics such as mobile phone and
tablets.
[0042] Referring to FIG. 4, exemplar dimensions: 0.65''/16=0.04
inches=1 mm and 1 mm/20 scans=50.mu. scan spacing; 1/2'' scan
range/2=1/4''.apprxeq.6.4 mm and 6.4 mm/150 scans=42.mu. scan
spacing; 500 dpi corresponds to spacing of .apprxeq.49.mu.;
150.times.20=3000 takes time of 1 second at 3000 scans per
second.
[0043] Although the preferred embodiment uses MRO OCT, alternate
embodiments use conventional time domain OCT, and swept source OCT.
In conventional time domain OCT, the reference optic 113 moves the
amount to be scanned in the depth of the target (e.g. up to
approximately 1 mm) and there is no requirement for the partially
reflective surfaces 109 and 129. In an alternate embodiment using
swept source OCT, the reference optic 113 is stationary, and there
is no requirement for the partially reflective surfaces 109 and
129.
[0044] Referring now to FIG. 5, an alternate embodiment of the
invention is depicted. In FIG. 5, the optical source 101 as an
array of optical sources going through a long beam splitter 403
with the probe beams directed upwards by a mirror 405. The beam
splitter 403 also directs the reference beams to partial mirrors
and modulating reference mirrors (not shown). This arrangement
reduces the required travel in the "z" direction. Scanning in the
"x" direction provides an OCT image of the same region also imaged
by a conventional camera 407 (such as a CCD array) and is suitable
for fingerprint imaging.
[0045] Referring now to FIG. 6, an alternate embodiment of the
invention is depicted. Numbered elements are consistent with FIG.
5. In FIG. 6, depicted is an X,Y projection of the same system as
in FIG. 5 and additionally showing the reference path turning
mirror 505, the partial reflective surface 507 and the modulating
reference mirror 509. Also depicted is a glass window--a target
contact surface--511 on which a finger 513 rests for the
fingerprint application, i.e. where the target is a fingerprint. A
light source 515 directs light along the target contact surface.
Owing to frustrated internal reflection, light scattering occurs
only where target is in contact with the surface. In this way, an
image of the target--a fingerprint--is obtained. OCT scanning is
accomplished by lateral translation in the "x" direction of the OCT
module included in the dashed box. It can be appreciated that in
this embodiment, the camera capturing the full surface fingerprint
has a portion of the image blocked as the OCT system scans.
[0046] Referring now to FIG. 7, depicted is an X,Y projection of
the same system as in FIG. 5 and additionally showing the reference
path turning mirror 505, the partial reflective surface 507 and the
modulating reference mirror 509. Also depicted is a glass window
511 on which a finger 513 rests for the fingerprint application.
The double headed arrow indicates a lateral motion; the OCT is
mounted on an actuator (not shown) a continuous lateral scan is
again accomplished by lateral translation in the "x" direction of
the OCT module included in the dashed box. It can be appreciated
that in this embodiment, the camera needs to be transparent at the
wavelength of the OCT system. Such cameras can be fabricated using
thin film technology consisting of arrays of light detectors and
transistor arrays, etc.
[0047] A light source similar to 515 of FIG. 6 directs light along
the target contact surface. Owing to frustrated internal
reflection, light scattering occurs only where target is in contact
with the surface. Alternatively illumination could be achieved by a
thin array of transparent array of light sources. In this way, an
image of the target--a fingerprint--is obtained.
[0048] The examples provided herein are not to be construed as
limiting the invention, which extends to the scope of the claims,
the specification and the drawings included herewith and to the
equivalencies thereto.
* * * * *