Ratcheting assembly and finger hood for multi-configuration fingerprint capture systems, devices and methods

Abstract

A fingerprint capture device includes a removable, magnetically attached finger aperture selector to facilitate reconfiguration of the device to image a wide range of finger sizes and body regions. The device housing and the selector are also configured for one-handed use, based on the angle and location of the imaging actuator and the selector relative to the device handle. The device includes a camera calibration mount to facilitate adjustments to the camera alignment. Software that is usable with the device can normalize the fingerprint characteristics based on the age and individual characteristics of the subject being imaged. Additional selectors may be interchanged, including ones with prisms and finger hoods.

Description

[0001] P324457.US.01 RATCHETING ASSEMBLY AND FINGER HOOD FOR MULTI-CONFIGURATION FINGERPRINT CAPTURE SYSTEMS, DEVICES AND METHODS CROSS REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of a) U.S. Provisional Application No. 63 / 879,586, filed September 10, 2025, and b) U.S. Provisional Application No. 63 / 750.172, filed January 27, 2025, which are hereby incorporated by reference in their entirety herein. This application is also related to PCT Application No. PCT / US2023 / 075222, filed on September 27, 2023, U.S. Provisional Patent Application Serial No. 63 / 410,561, filed on September 27, 2022, U.S. Pat. No. 10,496,870, filed on March 6, 2018, U.S. Pat. No. 11,003,883, filed March 7. 2018, U.S. Pub. No.

[0003] 2022 / 0071489, filed December 20, 2019, and PCT Pub. No. WO / 2020 / 132645 Al, filed December 20, 2019, all of which are hereby incorporated by reference in their entirety herein.

[0004] BACKGROUND

[0005] This disclosure relates generally to fingerprinting, and more specifically to methods and apparatus for non-contact fingerprinting of newborns, infants, toddlers, children and adults.

[0006] BRIEF SUMMARY

[0007] In one embodiment, a fingerprint capture device includes a removable, magnetically attached finger aperture selector to facilitate reconfiguration of the device to image a wide range of finger sizes and body regions. The device housing and the selector are also configured for one-handed use, based on the angle and location of the imaging actuator and the selector relative to the device handle. The device includes a camera calibration mount to facilitate adjustments to the camera alignment. Software that is usable with the device can normalize the fingerprint characteristics based on the age and individual characteristics of the subject being imaged. A set of interchangeable selectors may be provided, to include contact and non-contact fingerprint capture, as well as optional hood configurations to reduce incidental light interference, including some single-aperture selectors which have a single attachment configuration in the system.

[0008] In one embodiment, a fingerprint input system is provided, comprising a main housing, comprising an elongate handle comprising a longitudinal axis, and a rotation hub integrally formed with the elongate handle, the hub comprising an upper convex surface, an imaging opening in the upper convex surface, and a circular flange surrounding the upper convex surface, the circular flange comprising a superior undulating surface, a center hub magnet located in a center of the rotation hub, a plurality of peripheral hub magnets equally spaced around the circular flange and each of the plurality of hub magnets located a same hub radial distance from a center of the rotation 1

[0009] 4921-1033-1530'1P324457.US.01 hub, an actuator located on a front surface of the elongate handle, an imaging assembly inside the elongate handle and comprising an imaging axis, a detachable rotary' aperture top configured to form rotational interface with the rotation hub, the selector comprising a concave lower surface configured to form a complementary rotational interface with the upper convex surface of the hub, a plurality of finger receiving apertures, wherein each aperture is a different size and comprises a chamfered perimeter edge located in an aperture plane, and a plurality' of flanges surrounding the concave lower surface and configured to extend radially outward beyond the circular flange of the rotation hub. wherein the plurality of flanges are radially offset from the plurality of finger receiving apertures, and wherein the plurality of flanges each comprise an undulating surface complementary' to a portion of the undulating surface of the circular flange of the rotation hub, and a center top magnet located in a center of the detachable rotary' aperture top, wherein the center of the detachable rotary aperture top and the center of the rotation hub define a rotation axis, and a plurality of peripheral top magnets equally spaced around the plurality of flanges and each of the plurality of top magnets located a same top radial distance from a center of the top. The prism top may further comprise elongate projections and the interface hub comprises elongate cavities configured to receive the elongate projections of the prism top. The elongate projections may be located on the lower annular surface of the prism top and the elongate cavities are located on the outer annular surface of the interface hub. The prism top may further comprise a hood structure overlying the outer prism opening, and forming a finger insertion opening lateral to the outer prism opening. The hood structure may comprises a fixed structure and a movable structure. The fixed structure and movable structure may comprise a translatable tongue-in-groove interface. The tongue-in-groove interface may comprise retention blocks in a groove of the tongue-in-groove interface configured to resist separation of the movable structure from the fixed structure. The fixed structure and movable structure may comprise a rotatable joint configured to allow the movable structure to flip away from the outer prism opening. The fixed structure and movable structure may comprise a releasable latch interface that is configured to allow complete removal of the movable structure from the fixed structure. The rotational interface between the multiaperture top and the interface hub may be a uni-directional rotational interface. The uni-directional interface comprises a ratchet configuration may comprise an arrangement of alternating ramp and stop surfaces located on each of the multi-aperture top and the interface hub. The plurality of aperture top magnets of the multi -aperture top and the plurality of hub magnets in the interface hub may be located at the corresponding stop surfaces. The plurality of aperture top magnets and the plurality' of hub magnets may have an angled or offset arrangement configured to rotationally or horizontally bias the complementary stop surfaces of the uni-directional interface toward each other.

[0010] 2

[0011] 4921-1033-1530'1P324457.US.01 In another variation, a fingerprint input system is provided, comprising a main housing, the main housing comprising an elongate handle comprising a longitudinal axis, and an interface hub coupled to the elongate handle, the hub comprising an inner annular surface surrounding an imaging opening, an outer annular surface surrounding the inner annular surface, a plurality of peripheral hub magnets equally spaced around the outer annular surface and each of the plurality of hub magnets located a same hub radial distance from a center of the interface hub, an imaging assembly inside the elongate handle and comprising an imaging axis, a lighting assembly inside the elongate handle, a multi-aperture top configured releasably attach to and to form a ratchet interface with the interface hub, the multi -aperture top comprising an arrangement of alternating ramp and stop surfaces located on each of the multi-aperture top and the interface hub, a plurality' of finger receiving apertures, wherein each aperture is a different size, and a plurality' of aperture top magnets equally spaced around the lower annular surface of the multi-aperture top and each of the plurality of aperture magnets located a same top radial distance from a center of the multi -aperture top and comprising a complementary alignment to the plurality of hub magnets in the interface hub. The plurality of aperture top magnets of the multi-aperture top and the plurality of hub magnets in the interface hub may be located at the corresponding stop surfaces. The plurality’ of aperture top magnets and the plurality of hub magnets may have an angled or offset arrangement configured to rotationally or horizontally bias the complementary' stop surfaces of the unidirectional interface toward each other.

[0012] In another embodiment, a fingerprint input system is provided, comprising a main housing, comprising an elongate handle comprising a longitudinal axis, and a rotation hub integrally formed with the elongate handle, the hub comprising a hub interface surface, a center, an imaging opening in the hub surface, and a first plurality' of alignment structures equally spaced around the rotation hub and each of the plurality of alignment structures are located a same hub radial distance from the center of the rotation hub, an actuator located on the elongate handle, an imaging assembly inside the elongate handle and comprising an imaging axis, a detachable rotary aperture top configured to form rotational interface with the rotation hub, the selector comprising a top interface surface configured to form a complementary' rotational interface with the upper convex surface of the hub and comprising a center, wherein the center of the top and the center of the hub define a rotation axis, a plurality of finger receiving apertures, wherein each aperture is a different size and comprises a chamfered perimeter edge located in an aperture plane, a plurality of flanges surrounding the top interface surface and configured to extend radially’ outyvard beyond the rotation hub, wherein the plurality of flanges are radially offset from the plurality of finger receiving apertures, and a second plurality of alignment structures arranged in a configuration complementary to the first plurality' of alignment structures located on the rotation hub. The device 3

[0013] 4921-1033-1530'1P324457.US.01 may further comprise an adjustable camera alignment mount. The adjustable camera alignment mount may comprise a frame and three adjustment screws. The frame may comprises a polygonal shape with four sides and four comers, with first of the three adjustment screws located in the middle of one of the four sides and the second and third adjustment screws located at two of the four comers farthest from the first screw. The adjustable camera alignment mount may be releasably couplable to the imaging assembly via mount magnets attached to the frame. The imaging assembly may be located in a frame opening of the frame. The three magnets may be embedded in the frame, and wherein the three adjustment screws are magnetically attachable to the magnets. The three adjustment screws may be attached to the main housing. The system may further comprise a first heatsink thermally coupled to the imaging assembly. The system may further comprise a lighting assembly with a plurality of light sources within the main housing. The lighting assembly may comprise a circular base. The system may further comprise a light diffuser above the lighting assembly. The system may further comprise a lighting heatsink thermally coupled to an inferior surface of the lighting assembly. The system may further comprise a camera support between the imaging assembly and the adjustable camera alignment mount. The first plurality of alignment structures and the second plurality of alignment structures may each compnse magnets. The system may further comprise a third plurality of alignment structures located on the rotation hub and a fourth plurality of alignment structures complementary to the third plurality of alignment structures and located on the detachable rotary aperture top. The third plurality' of alignment structures may comprise a plurality of alternating undulating or ramp surfaces, and the fourth plurality of alignment structures may comprise a plurality of alternating undulating or ramp surfaces complementary to the third plurality of alignment structures. The third plurality of alignment structures may be located along a superior peripheral circular surface of the rotation hub. The fourth plurality of alignment structures may be located on inferior surfaces of the plurality of flanges. The system may further comprise an elongate planar measurement tool compnsing a plurality of different apertures arrange serially by size along the tool. The measurement tool may further comprise a plurality of ordinal indicia corresponding to the plurality of different apertures. The fingerprint devices described herein are designed to collect platen-free fingerprints, and other body parts, over a wide range of ages and physical sizes in a consistent manner.

[0014] In one embodiment, a fingerprint input system is provided, comprising a housing, comprising an interface hub, the hub comprising an imaging opening, an annular surface surrounding the imaging opening, an imaging assembly inside the housing and comprising an imaging axis, a lighting assembly inside the housing, a multi-aperture top configured to releasably attach to and to form a rotational interface with the interface hub, the multi-aperture top comprising 4

[0015] 4921-1033-1530'1P324457.US.01 a lower annular surface configured to form a complementary rotational interface with the annular surface of the interface hub, a plurality of finger receiving apertures, wherein each aperture is a different size, and a prism top configured to releasably attach to and to form a non-rotational mechanical interfit interface with the interface hub, the prism top comprising a prism, a prism housing with an outer prism opening and wherein the prism housing is configured to retain the prism at the outer prism opening, an annular surface configured to form a complementary interface with the annular surface of the interface hub. The prism may be a triangular prism, including an irregular or scalene triangular prism, or a porro prism. The outer prism opening of the prism housing may be configured to intersect the imaging axis of the imaging assembly when the prism housing is attached to the interface hub. The prism housing may further comprise an inner prism opening, and wherein the inner prism opening may be configured to intersect the imaging axis of the imaging assembly when the prism housing is attached to the interface hub. The prism housing may further comprise a light baffle structure at least partially surrounding the inner prism opening and configured to block light from the lighting assembly when the prism housing is attached to the interface hub. The prism housing may comprise an upper prism top shell comprising the upper prism opening and further comprising an upper prism frame to retain the prism, and a lower prism top shell comprising the lower prism opening and the light baffle, and comprising a lower prism frame to retain the prism. The lower annular surface of the prism top may be integrally formed with the lower prism housing. The prism may comprise an outer prism surface configured to be positioned at the outer prism opening, a base prism surface configured to be positioned at the inner prism opening. The prism may further comprise an intermediate prism surface coated with a light absorbing material. A surface area of the outer prism opening may be greater than a surface area of the outer prism surface. The outer prism surface may be configured to be oriented at an angle of incidence of 42 degrees or less when the prism housing is attached to the interface hub. The angle of incidence of the outer prism surface may be in the range of 10 degrees to 30 degrees with respect to the imaging axis. The angle of incidence of the outer prism surface may be in the range of 15 degrees to 25 degrees with respect to the imaging axis. The angle of incidence of the outer prism surface may be in the range of 20 degrees to 25 degrees with respect to the imaging axis. The base prism surface is, relative to the imaging axis of the imaging assembly, angled in the range of 20 to 60 degrees. The base prism surface is, relative to the imaging axis of the imaging assembly, angled in the range of 30 to 50 degrees. The base prism surface is, relative to the imaging axis of the imaging assembly, angled in the range of 35 to 45 degrees. The light baffle comprises an inferior vertical wall. The light baffle may further comprise at least one horizontal wall projecting transversely from the vertical wall. The inferior vertical wall may be angled toward the imaging axis by 0 to 10 degrees. The system may further comprise a plurality of ferromagnetic hub elements 5

[0016] 4921-1033-1530'1P324457.US.01 located along the annular surface of the interface hub, and a plurality of ferromagnetic top elements located along the annular surface of the multi-aperture top, wherein at least one of the plurality of ferromagnetic hub elements and the plurality of ferromagnetic top elements comprises magnets. The plurality of ferromagnetic hub elements comprises a plurality of hub magnet elements. The system may further comprise a plurality of ferromagnetic prism top elements located along the annular surface of the prism top. The annular surface of the interface hub may comprise an arrangement of alternating ramp and stop surfaces, and wherein the annular surface of the multiaperture top comprises an arrangement of alternating ramp and stop surfaces complementary to the arrangement of alternating ramp and stop surfaces of the interface hub. The system may further comprise a plurality of ferromagnetic hub elements located along the annular surface of the interface hub, and a plurality of ferromagnetic top elements located along the annular surface of the multi-aperture top. The he plurality of ferromagnetic hub elements and the plurality of ferromagnetic top elements may be located at their corresponding stop surfaces. The plurality of ferromagnetic hub elements and the plurality7of ferromagnetic top elements have an angled or offset arrangement configured to rotationally or horizontally bias the complementary stop surfaces of the uni-directional interface toward each other.

[0017] This system design addresses many of the issues associated with collecting fingerprints with traditional non-contact devices, primarily cell phone-based camera biometric systems. With cell phone-based camera systems, the camera and finger of the subject to be imaged are held independently in free space. The subject holds a finger in front of the camera and the distance between the finger and the camera can vary, thus changing the image size and the spatial resolution of the pixels of the finger. Each cell phone also has a focus range which must be adhered to in order to get sharp images. Before the fingerprint image can be analyzed and stored as a fingerprint template, the inconsistent spatial resolution needs to be normalized to a standard 500 pixels / inch to be compatible with other automated biometric identification systems (ABIS). The finger is also held in free space in front of the camera; thus the user needs to be concerned with whether the fingerprint(s) is properly facing and aligned with the camera. In addition, there is a concern as to what is visible in the background behind the subject. Bright lights and / or a similarly colored background scene could make it difficult to isolate the finger image. Camera cell phone fingerprint systems do not use specific hardware but are software applications that can be hosted on a wide variety of cell phone devices. Each cell phone device manufacturer and model will have different total pixel counts, optical resolutions, fields-of-view, and light source powers and light source spectral characteristics. All of these variables need to be accounted for with fingerprint software programs that use cellphones to collect finger images. Cellphone based systems are also designed for adult-use only and do not have any corrections for infants or children. The current device here 6

[0018] 4921-1033-1530'1P324457.US.01 is designed to eliminate or minimize the issues described, including for use on all ages from infants to adults, and are also improvements to earlier developed designs described in U.S. Pat. No.

[0019] 10,496.870, U.S. Pat. No. 11.003,883, U.S. Pub. No. 2022 / 0071489, PCT Pub. No. WO / 2020 / 132645A1, and Saggese S, Zhao Y, Kalisky T et al. Biometric recognition of newborns and infants by non-contact fingerprinting: lessons learned, Gates Open Research 2019, 3:1477.

[0020] BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A and IB are left and right side views of one embodiment of a fingerprint capture device; FIGS. 1C and ID are front and rear views of the device in FIGS. 1A and IB; FIGS. IE and IF are top and bottom views of the device in FIGS. 1A to ID; FIG. 1G is a perspective exploded view of the device in FIGS. 1A to IF; FIG. 1H is a top perspective view of the device in FIGS. 1A to IF; FIG. II depicts in the device in FIGS. 1H in use; FIG. 1J schematically depicts the alignment of the rotary aperture top and the main housing;

[0021] FIG. 2A is a schematic top view of the alignment of the rotary aperture top with the magnetic interface; FIG. 2B schematically depicts the rotation of the rotary aperture top; FIG. 2C is a schematic top view of the realignment of the rotary aperture top in a different position than in FIG.

[0022] 2A; FIGS. 2D and 2E are side-elevational views of the device, illustrating the peripheral interface between the hub and rotary top, with the rotary top partially and fully seated positions, respectively;

[0023] FIGS. 3A to 3C are rear perspective views of a fingerprint capture device attached to different rotary aperture tops;

[0024] FIGS. 4A to 4D are perspective, top, bottom and side views, respectively, of one exemplary embodiment of a rotary' aperture top; FIGS. 4E to 4H are perspective, top, bottom and side views, respectively, of another exemplary embodiment of a rotary aperture top; FIGS. 41 to 4L are perspective, top, bottom and side views, respectively, of still another exemplary’ embodiment of a rotary aperture top;

[0025] FIG. 5 A is a longitudinal cross-sectional view of the main housing with the optical centerline indicated. FIG 5B is an orthogonal side view of a longitudinal cross-sectional view of the main housing. FIG 5 C is an orthogonal side view of a longitudinal cross-sectional view through a fully assembled fingerprint capture device. FIG 5D is a perspective view of the main housing showing the alignment of the camera and aperture.

[0026] FIG. 6A is a perspective view of a fixed optical configuration with respect to the rotary' aperture top. FIG. 6B is a side view of the fixed optical configuration with respect to the rotary' aperture top in FIG. 6A. FIG. 6C is a perspective view of a longitudinal cross-sectional view of the fixed optical configuration with respect to the rotary aperture top in FIGS. 6A and 6B. FIG.

[0027] 7

[0028] 4921-1033-1530'1P324457.US.01 6D is a side view of a longitudinal cross-sectional view of the fixed optical configuration with respect to the rotary aperture top in FIGS. 6A to 6C.

[0029] FIG. 7A is a perspective exploded view of an imaging configuration. FIG. 7B is a side exploded view of an imaging configuration in FIG. 7A. FIG. FIG. 7C is a perspective view of a fixed optical configuration. FIG. 7D is a side view of the fixed optical configuration in FIG. 7C.

[0030] FIG. 8A shows a perspective view of a camera alignment configuration. FIG. 8B shows perspective with visible hidden lines and magnets placement in camera alignment configuration shown in FIG. 8A. FIG. 8C shows a perspective view and variable alignment angles of camera alignment configuration shown in FIGS. 8A and 8B.

[0031] FIG. 9A is a schematic overlay outline of the seven finger apertures. FIG. 9B shows a top view of finger selector guide.

[0032] FIGS. 10A to 10C show a perspective view of the dot locations on the rotary aperture top. FIGS. 10D to 10F show captured images of the apertures and dots in FIGS. 10A to 10C.

[0033] FIG. 11 A show all the dots placement on the infant rotary aperture top. FIG. 11B shows all the dots placement on the adult rotary' aperture top. FIG. 11C shows all the dots overlaid along the bounding box.

[0034] FIGS. 12A to 12C show bounding lines used to detect aperture size.

[0035] FIGS. 13A to 13F show finger images captured using different aperture sizes.

[0036] FIG. 14A shows a day of birth fingerprint image. FIG. 14B shows a 1 year old’s fingerprint image. FIG. 14C shows an adult's fingerprint. FIG. 14D shows a normalized minutiae map of the day of birth fingerprint image in FIG. 14A. FIG. 14E shows a normalized minutiae map of the 1 year old’s fingerprint image in FIG. 14B. FIG. 14F shows a normalized minutiae map of the adult’s fingerprint image in FIG. 14C.

[0037] FIG. 15A shows data on little finger size vs age. FIG. 15B shows data on middle finger size vs age.

[0038] FIG. 16A shows a raw image of a finger, FIG. 16B shows the binary mask for that aperture used, FIG. 16C shows the image of the finger after applying the mask to the raw image, and FIG.

[0039] 16D shows a zoomed in image of the finger as it would be presented to the user.

[0040] FIG. 17A shows a raw image of a finger with the automatic detection of a core shown, and FIG. 17B shows the five different locations that is suggested to the user to place the core during image collection.

[0041] FIG. 18 is a flowchart of the system operation.

[0042] FIG. 19A is a perspective view of another embodiment of a fingerprint capture device with the rotary top separated from the main housing. FIG. 19B is a longitudinal cross sectional detailed view of the superior region of the fingerprint capture device in FIG. 19A. FIG. 19C is an exploded 8

[0043] 4921-1033-1530'1P324457.US.01 view of the exemplary components of the device in FIG. 19A. FIG. 19D is a perspective detailed view of the rotation hub and optical cover of the main housing in FIG. 19A. FIG. 19E is a perspective cross-sectional view through the main housing in FIG. 19A.

[0044] FIG. 20A schematically depicts the field-of-view of an imaging assembly wherein a triangular image capture prism is oriented with its base surface oriented orthogonally to the imaging assembly. FIG. 20B schematically depicts the field-of-view of an imaging assembly with a triangular prism oriented to position a lateral face used for image capture within the field-of-view.

[0045] FIG. 21 A schematically depicts the imaging assembly and prism of FIG. 20A with a lighting array. FIG. 21B schematically depicts the imaging assembly and prism of FIG. 20B with a lighting array and light baffle structure.

[0046] FIG. 22 is a schematic depiction of an imaging assembly and prism top.

[0047] FIG. 23A and 23B are front and back perspective views another embodiment of a fingerprinting system with a non-contact rotary top.

[0048] FIGS. 24A to 24F are top perspective, side elevational, rear, frontal, bottom plan and top plan views, respectively, of the fingerprinting system in FIGS. 23A and 23B with a contact prism top. FIG. 24G is a top plan view of the fingerprinting system in FIGS. 24F without the upper prism top shell. FIG. 24H is a top plan view of the fingerprinting system in FIGS. 24F without the prism top. FIGS. 241 and 24J are longitudinal cross-sectional side and side perspective views of the fingerprinting system in FIGS. 24A to 24F.

[0049] FIGS. 25A to 25C are exploded top, side and bottom views, respectively, of the interface hub and prism top in FIGS. 24A to 24F.

[0050] FIGS. 26A to 26E are front perspective, back perspective, top perspective, bottom perspective, and side cross-sectional views, respectively, of the lower prism shell.

[0051] FIGS. 27 A to 27D depict various exemplary image processing steps for contact fingerprint images.

[0052] FIG. 28A is a top perspective view of another embodiment of a fingerprint capture device. FIG. 28B depicts the device of FIG. 28A with the multi-aperture top separated from the device body, depicting he ratchet rotational interface. FIGS. 28C and 28D are detailed close-up view of the rotational interface between the multi -aperture top and the hub interface. FIG. 28F is a schematic close-up view depicting the position and orientation of the of the removable top relative to the ramp and stop surfaces of the hub interface. FIG. 28G is a sagittal cross-sectional view of the device in FIG. 28A, through one pair of magnets of the top and hub interface. FIG. 28H is a schematic top view of the plurali ly of top magnets and the plurality of hub magnets, without the top and without the hub interface. FIG. 281 is a schematic sagittal cross-sectional view through the 9

[0053] 4921-1033-1530'1P324457.US.01 hub interface and through an aligned pair of hub and top magnets. FIGS. 28J and 28K are schematic top and bottom views of the hub interface and top magnets, and of the multi-aperture top with hub magnets, respectively. FIG. 28L is a longitudinal cross-sectional view of the device in FIG. 28A.

[0054] FIGS. 29A to 29E are rear perspective, front perspective, frontal, posterior and side elevational views of another embodiment of the device with a contact top and finger hood. FIG.

[0055] 29F depicts the device of FIGS. 29A to 29E with the contact top separated from the device body. FIGS. 29G and 29H are close-up top perspective and bottom perspective views of the interface between the contact top and hub interface, depicting the ratchet configuration and fixation / alignment posts and cavities, respectively. FIG. 291 is a longitudinal cross-sectional view of the device in FIGS. 29A to 29E.

[0056] FIG. 30A is rear perspective view of the biometric capture system with the light hood separated from the rest of the imaging top. FIGS. 30B and 30C illustrate the system of FIG. 30 with the light hood attached to the imaging top in a storage mode and cover mode, respectively.

[0057] FIGS. 31 A to 3 IF are top perspective, bottom perspective, top plan, front elevational, bottom plan, rear elevational views of an exemplary prism contact top. FIGS. 31G and 31H are side elevational and side cross sectional views of the prism contact top in FIGS. 31A to 31F. FIGS.

[0058] 311 and 31J are exploded perspective and exploded cross-sectional views of the prism contact top in FIGS. 31A to 31H.

[0059] FIGS. 32A and 32B are top perspective and side cross-sectional views of the prism contact top of FIGS. 31A to 31J attached to the system depicted in FIGS. 28A and 29 A.

[0060] FIGS. 33A to 33D are schematic perspective views of various exemplary multi-aperture fingerprinting systems without any magnetic attraction / bias elements between the hub and top.

[0061] DETAILED DESCRIPTION

[0062] The device comprises a self-contained camera system that has a dedicated camera with fixed focal length optics, integrated light source, and a fixed optical configuration that positions the subject's finger (or other body part) at a specific location with the use of an adjustable aperture that the subject rests their finger upon. The device 100 is small enough for single hand operation and an exemplary overall design is depicted in FIGS. 1 A to IF, comprising external view of the assembled device 100, comprising a main housing 102, a rotary top 104a configured for selecting the size of the finger support aperture 106a-d, a trigger or actuator 108 to initiate the collection of images and a communication link 110, such as a USB cable connecting the device to a computer. In some variants, a wireless communication link via Bluetooth or other wireless communication protocol may be provided. FIG. 1G shows an exploded view of the device 100 depicting the 10

[0063] 4921-1033-1530'1P324457.US.01 internal and external system components. FIG. 1H shows the device in position for use and FIG. II shows the subject finger being paced onto the aperture for image collection while the device is held by the user.

[0064] In this exemplary embodiment, the main housing 102 may comprise a two-piece shell 102a, 102b configured to form a complementary interfit with each other, and to define an interior cavity to contain the camera assembly 112 with lens 114, lighting assembly 116 and window / diffuser. The two shells 102a, 102b together form a handle region 120 of the housing 102, and one shell 102a includes or both shells together form a rotation hub 122 to which the rotary top 104a is releasably attached. Additionally, the device may also include a camera mounting assembly 170, which may be used to adjust the alignment of the camera assembly 112 during manufacturing and / or servicing, one or more heatsinks in the camera assembly and / or lighting assembly, additional optic devices such as a camera aperture structure 152 and aperture support structure 154, an optically clear window 156 and window seal to protect the interior contents of the device 100.

[0065] The main housing 102 may comprise a generally elongate shape, with a proximal end 124 from which the wired communication link or cable 110 may extend, a distal end 126 where the rotation hub 122 is located, a ventral surface 128 where the actuator 108 may be located, and a dorsal surface 130. The main housing 102 may further comprise gripping structures on its exterior surface to reduce slippage and improve stability when using the device 100. In this particular embodiment, aflat palm grip structure 132 is optionally provide on the dorsal surface to increase contact and with the flexed palm of the user when grasped, which may reduce torqueing or rotation of the device 100 during use.

[0066] As depicted in FIG. IE, the rotary top 104a comprises a generally dome-shaped structure 134a with a plurality of apertures 106a-d spaced around a rotation center 136a of the top 104a, with each aperture 106a-d having a different size but where the center-to-center spacing of adj acent apertures 106a-d are the same, and wherein the aperture plane angle of each aperture 106a-d relative to a central rotation axis through the rotation center 136a of the rotary top 104a is the same. This arrangement allows the user to maintain imaging consistency7with the camera assembly regardless of the selected aperture 106a-d. Indicia 138a may be provided on the top 104a to facilitate identification of the aperture size range, subject age, and / or body part associated with each rotary top. To facilitate the rotation of the rotary top 104a to select the desired aperture 106a-d, a series of alternating flanges 140a and finger recesses 142a may be around the edge or periphery of the dome structure 143a. The flanges 140a may comprise a radial outward height of 3 mm to 4 mm, 3 mm to 8 mm, or 2 mm to 10 mm, and circumferential length of 20 mm to 25 mm, 22 mm to 30 mm, or 15 mm to 35 mm, and a longitudinal height of 8 mm to 10 mm, 6 mm to 15 mm, or 11

[0067] 4921-1033-1530'1P324457.US.01 5 mm to 15 mm. The recesses may have a complementary radial outward height and longitudinal height corresponding to the flanges 140a, but the circumferential length may be the same, smaller or larger than the flanges 140a, having a circumferential length of 10 mm to 13 mm. 8 mm to 20 mm, or 11 mm to 15 mm. To facilitate image capture, the middle of each recess 142a may be radially aligned with the center of each aperture 106a-d, except for the recess 142a located adjacent to the indicia 138a, if any.

[0068] Releasable attachment between the hub 122 and the top 104a may be provided by a ball latching or snap-type mount, or in this particular embodiment, via a plurality of complementary arranged magnets on the hub 122 and rotary top 104a, as depicted in FIG. 1J. The plurality of magnets on the hub 122 may include a central magnet 144 and peripheral magnets 146a-e equally spaced around and from the central magnet 144. Complementary rotary top magnets, depicted in FIG. 4C, including a rotary top central magnet 148 and peripheral magnets 150a-e which are also equally spaced around and from the rotary top central magnet 148. Magnets are placed around the outer edge of the top to not only connect it to the housing but to also provide reproducible, discrete rotational positions to align each individual aperture at a precise location within the FOV of the camera. . The central magnet pair 144, 148 on the rotation axis that centers the rotary top 104 acts like a shoulder screw or axle and stops the rotary top 104a from moving laterally. FIG 1J shows a configuration with five pairs of magnets, with one set in the top (3 / 16” diameter x 3 / 16” thick neodymium, 2.2 lbs. pull / magnet) and the second set in the main housing. (3 / 16” diameter x ' / s” thick neodymium, 1.6 lbs. pull / magnet). A typical pull strength with the six sets of magnets on the main housing has been tested to 5 lbs., therefore, the top will lock securely to the main body when the magnets are aligned. The top is approximately two inches in diameter, which will fit within the average grip size of an adult hand. The shear strength of the sets of magnets between the top and the main housing is < TBD pounds. At this level of force, the user can rotate the top with the thumb and pointer finger of the hand holding the device, as shown in FIG. II. The strength of the magnets are selected to firmly attach the top, but allow the shear forces to be easily overcome using the thumb and pointer finger to rotate the top to the next position. One capability7that the magnetic configuration provides is the ability to easily remove a rotary7top and replace it with another that has different sizes or configurations, thus allowing one base device to accommodate a wide range of sizes and body parts to scan. In some further variations, the interface between the rotary top and the rotary hub may optionally comprise complementary mechanical detents and projections to facilitate alignment of the apertures of the rotary top with the imaging aperture of the hub. The detents may be provided on the hub or the top, with the projections on the hub or the top. respectively. In other embodiments, a complementary central axle and central opening may¬ be provided between the hub and top, to also facilitate alignment between the hub and top, and to 12

[0069] 4921-1033-1530'1P324457.US.01 potentially resist inadvertent separation between the hub and top. In some variations, the axle and opening may be in addition to or in lieu of the central magnets of the hub and top.

[0070] FIGS. 2A to 2C shows how the rotary top 104a is adjusted to access different aperture positions. When the magnets 146a-e, 150a-e are all aligned, the top 104a will be positioned with one of the apertures, e.g. aperture 106b in FIG. 2A, centrally aligned in the camera field of view (FOV), as indicated by the arrow. The magnets 146a-e, 150a-e are strong enough to hold the top 104a in location, but if a lateral force is applied, the magnetic attachment of the peripheral magnets 146a-e. 150a-e will rotationally separate (FIG. 2B) and allow for easy rotation until the magnets self-align again and automatically settle onto the next or closest alignment position, without the user needing to align the next aperture, e.g. aperture 106a, as shown in FIG 2C. If, however, the rotation of the top 104a is stopped halfway or part way such that the magnet pairs 146a-e, 150a-e are not aligned, the top 104a can be easily removed and replaced with another top, e.g. tops 104b or 104c depicted in FIGS. 3B and 3C, respectively. The example in Figure 2A to 2C shows five magnet pairs 146a-e, 150a-e, which creates five rotational positions. In other embodiment more or fewer magnet pairs may be provided, resulting in a larger or smaller number of rotational positions. A five-position top is a balance between maximizing the number of positions and the diameter of the device. The position with the indicia 138a may be used as a storage position to block debris from contacting the camera aperture or window. As the number of spots increases, the diameter of the top must increase to fit the apertures. The current design has a diameter that fits well within the grip diameter of an adult. The size of the apertures impacts the required diameter also and a top with only the smaller apertures could have more than five positions without increasing the diameter and single-hand usability of the device. A six or seven position top may be used without increasing the diameter at all if the apertures were small enough to fit.

[0071] To further facilitate the alignment of the rotary top 104a with the hub 122, or to otherwise bias a rotary top 104a toward an alignment position between the hub magnets 146a-e and rotary’ top magnets 150a-e, the rotary top 104a and the hub 122 may comprise complementary undulating surfaces or alternating angled ramp surfaces 160, 162, as depicted in FIGS. 2D and 2E, such that when the rotary’ top 104a is placed onto the hub 122, the attraction between the center magnets 144, 148a of the hub 122 and top 104a will attempt to minimize the gap distance between the center magnets 144, 148a (depicted in FIGS. 1J and 4C) and the top 104a. The undulating or alternating ramp surfaces 160, 162 will bias the top 104a to slide and rotate to minimize the gap distance, which in turn will bring the rotary top 104a into a position where the peripheral magnets 150a-e are closer to the peripheral magnets 146a-e of the hub 122a, to bring the rotary' top 104a into full alignment. The undulating surface or alternating ramp surface 160 of the hub 122 may be located on a ring-like or annular surface 164 surrounding the center dome 166 of the hub 122,

[0072] 13

[0073] 4921-1033-1530'1P324457.US.01 where the peripheral hub magnets 146a-e are located. Together, the magnets and the undulating surfaces facilitate selective alignment of the apertures 106a-e of the top 104a with the imaging aperture 167 of the hub 122. The corresponding undulating surface or alternating ramp surface 162 of the rotary top 104a may be located along the inferior surfaces of the flanges 140a-e and / or inferior surfaces of the rotary top 104a adjacent to the recesses 142a-e.

[0074] The self-alignment of the multiple magnets provides the primary' method of alignment for the aperture centered on the camera FOV. The main housing and tops are designed so that the paired magnets will be close to each other without touching. This helps reduce the strength of these magnets and allow the user to easily rotate the top to the next position. In order to provide additional accuracy to the alignment, the housing and the rotary' dial have interlocking features between the top and housing to further assist in keeping the rotational alignment of the top with the main housing accurate and reproducible.

[0075] When being used for newborns and infants, the device size and rotary top magnetic design assists the biometrician in collecting the fingerprints. For adult-only systems, the subject can interact with the device. For infants, the device must be brought to the subject and the biometrician will need to align the finger of the subject with one hand, and user their second hand for interacting with the device. Being able to hold the subject and perform all the functions of the device (e.g. rotate the top to get the best aperture size for that specific finger without letting go of the subj ect and triggering the image collection).

[0076] To use the fingerprinter over a wide age range, i.e. newborns, infants, children, and adults, the device needs to be configured to properly support fingers of different sizes. This is accomplished by having different sized apertures to support a variety of different finger sizes. If the aperture is too small, then the area scanned will result in not enough fingerprint minutiae visible to be detected for accurate analysis and if too large, the finger may fall into the device and not sit flat on the image plane and will allow external light to be let into the sample chamber. While scanning each individual finger on the subject, an appropriately sized aperture provides 1) support for the finger, 2) allows the finger to be viewed unobstructed by' the camera, 3) it sets the position of the finger within the fixed focus range of the optical system, 4) sets the finger at a known distance with a known optical resolution, and 5) rejects external light sources from reaching the camera.

[0077] FIG. 9A is a schematic depicting the outlines of seven apertures 1, 2, 3, 4, 5, 6, 7 that span a finger size range that can be used from newborns through adults, with each aperture positioned at a common center. Table 1 lists the lengths and widths of the apertures, are sized proportionally to span between the smallest diameter for a newborn’s little finger (FIG. 1 A) and the size of the middle finger of a teen / adult, when the finger is fully grown (FIG. 15B). FIG. 15A is a data graph 14

[0078] 4921-1033-1530'1P324457.US.01 depicting the average, 5thpercentile and 95thpercentile ranges of the diameter (or width) of the fifth or little finger for a newborn can be as small as 5 mm and will increase up to 13mm at the age of thirteen. Similarly, FIG. 15B shows the sizes for the third or middle finger width vary from 6 mm to 15 mm over the same age ranges, from anthropometric data disclosed in the Physical Characteristics of Children report by the Highway Safety Research Institute at the University of Michigan (UM-HSRI-BI-75-5), Final Report (May 31, 1975).

[0079] Table 1:

[0080]

[0081] These sizes have been chosen to span this range in seven steps, but any other dimensions or combination of dimensions can be used for a particular application. A ruler 900, which may comprise cardboard or a hard polymer, may be provided with serially arranged apertures 902a-g and corresponding indicia 904a-g to facilitate sizing of the desired aperture for a particular subject’s finger, whereby the aperture 902a-g is selected to support the maximum finger width without the finger passing through the aperture 902a-g. Each of these apertures 902a-g have a diameter corresponding the widths recited in the table above of 5.5 mm, 7 mm, 8.5 mm. 10 mm, 12.25 mm, 13.4 mm and 15.25 mm. In other variations, aperture widths may span a range of 5 to 16 mm, 4 to 18 mm or 3 to 20 mm and may be provided using 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 apertures. Although the exemplary7indicia 904a-g in ruler 900 comprises numerals, letters or other symbols may be used and may correspond to the indicia provided on the rotary tops 104a-c adjacent to each of the apertures 106a-I or rotary7top indicia 138a-c.

[0082] FIGS. 3 A to 3C show three different examples where the device 100 is configured or provided with a series of rotary tops 104a-c configured with a range of different aperture sizes for a specific application. In the set of apertures provided in these tops 104a-c, the apertures are each a different size, but in other variations, there may be overlapping size ranges between the different tops. FIG. 3 A shows a top 104a installed on the device 100 that is intended for newborns and children, and contains apertures #1, #2, #3 and #4 from Table 1, along with a closed position

[0083] 15

[0084] 4921-1033-1530'1P324457.US.01 marked by indicia 138a. This top 104a is also shown in FIGS. 4A, 4B, 4G and 4J. FIG. 3B shows a top 104b installed on the device 100 that is intended for adolescent and adults with contains apertures #4, #5, #6 and #7 from Table 1, along with a closed position by indicia 138b. This top 104b is also shown in FIGS. 4C, 4D, 4H and 4K.

[0085] FIG. 3C shows an optional top 104c that is configured to be used to properly place the hand of a subject for scanning the palm pads just below the fingers, where the “fin” structure 168 on the top 104c is positioned at the top edge of the FOV of aperture 106i so that the interdigital folds (i.e. webbing) between tw o fingers can be placed to each side against it to align the hand and to image the palm pad. In this top design 104c, the aperture is completely open to image the largest area possible of the finger pads. A sloped, wider flange 140k may be provided adjacent to the aperture 106i to further support the hand or palm of the subject during image acquisition. This top 104c is also shown in FIGS. 4E, 4F, 41 and 4L. The inner edges of apertures 106a-h may be sharp or angled, or may comprise a rounded edge. It is postulated that a rounded edge may reduce light shadow-s near where the imaged finger contacts the inner edges of the apertures 106a-h, by allowing more direct or indirect light at the inner edge.

[0086] The location of minutiae on the finger is within an area much like the shape of the apertures 1 to 7 shown in FIG 9A, which comprise a generally oval or ovoid shape with a smaller distal end and a larger base. The shape of the apertures 106a-h on the tops 104a, 104b may be configured to keep the most minutiae exposed but also to support the finger. A rectangular aperture does not support the finger as w ell since the tip of the finger is often smaller than the knuckle area. The shape three dimensional shape of the aperture mimics the shape of the rounded shape of the finger, so that the finger is supported with an edge that conforms to the finger surface. FIGS. 4A to 4D and FIGS. 4G to 4K show that the shape of the apertures 106a-h mimics the shape of the finger, comprising the generally oval or ovoid shape with a smaller distal end and a larger base and with the dimensions recited in Table 1. Each aperture 106a-h is configured with a distance from the camera that will generally place the middle of the aperture and thus the finger (center being from the fingerprint to the fingernail) at a desired focus. Fingers are all different shapes and sizes, so this is a general guide and positions of the actual finger will vary7. The device can image over a wide depth range and will have good focus over a 10 mm below the aperture up to above the aperture to keep the fingerprint in focus.

[0087] The main housing 102 has several features that simplify fabrication and ensure that the optical alignment between the camera and the finger placement is stable and consistent between each device. The main housing 102 may comprise a main shell 102a and a shell cover 102b, where the main shell 102a may be a single part that is printed, cast or machined, and containing relatively more alignment and retention features compared to the shell cover 102b. By using a single part for 16

[0088] 4921-1033-1530'1P324457.US.01 the main shell 102a, the dimensions can be controlled more precisely then when multiple parts are used for the different functions, which may provide greater precision and reproducibility when placing internal components and to achieve the desired camera alignment.

[0089] As illustrated in FIGS. 5 A to 5D, the main shell 102a comprises features that support the optical components, including a camera assembly 112 with an integrated lens, a camera mount 170, an LED PCB 116 with an optical diffuser, so that these components are all aligned sufficiently along the optical centerline 500 and through the imaging aperture 167 of the rotation hub 122 and the attached rotary top 104b. The main shell 102 may also has features that block scattered LED light from reaching the camera and it also blocks any external light sources from leaking into the device through the other apertures on the top, including light blocking internal walls and light absorbing or diffusing paint. The rotation hub 122 has a concave rounded chamber 172 underneath the hub 122 that assists in homogenizing the light for diffuse illumination.

[0090] By fixing all of the optical components and fixing the position of the finger, the optical resolution, field of view, light source intensity and spectral content are all kept consistent or variations may be reduced, and the finger can be held at the location of desired focus for each image collection. In addition, when the finger is placed on the aperture, the disclosed design reduces external sources of light which may obscure the finger and may keep the (non-finger) background portions of the image consistent. The result of using all these features is the collection of an image with increased quality and contrast. FIGS. 6A through 6D are views of the sub assembly 600 with an exemplary top 104b show the alignment of the various optical components 112, 114. 116, 118 and each position is set by the main shell 102a. FIGS. 7A through 7D show additional view s where the pinhole aperture structure 700 and a pinhole aperture support 702 has been added to the top of the standard f / 3 lens 114 to increase the f / # to f / 10 so that the depth of focus of the camera assembly 112 can be increased to be able to obtain sharp images of the finger surface even though the finger is curved, with different portions of the finger at different distance to the camera assembly 112.

[0091] For the camera assembly 112, the main shell 102a provides x-y-z alignment to a high enough accuracy so that only small alignment adjustments are required. Variations in the camera assembly 112, however, may benefit from a finer angular alignment. For example, the camera chip, lens mount, lens, aperture and camera mount will not always have the exact same relative positions for every camera assembly 112, which may result in the center of the camera FOV varying between each camera / optics subassembly. To correct this, slight angular alignment and / or Z-axis translational adjustment of each camera assembly may be performed to improve alignment and / or depth of field location.

[0092] 17

[0093] 4921-1033-1530'1P324457.US.01 Fine alignment and securing the position of a camera assembly in a small, handheld device may be difficult to achieve, due to space constraints. In some examples, a 3-point magnetic kinematic camera mount and alignment assembly 170, depicted in FIGS. 8A to 8C, may be provided to allow for adjustment of the camera assembly 112 to center the lens aperture in the FOV and to permanently fix the camera pointing angle to retain alignment. Kinematic mounts are ty pically designed for components that need to be repetitively removed and replaced with a high degree of positional and angular reproducibility. For the disclosed devices, the camera assembly may be aligned once and then securely retain alignment for long term use. The alignment assembly 170 comprises three adjustable magnetic screws 802a-c that attach to corresponding internal locations in the main housing whose heads 804a-c will insert into the retention 802acavities 806a-c of the alignment frame 808 and be secured magnetically. The general alignment of the camera assembly 112 may be fixed with standard alignment features and structures built into the device housing. Fine adjustment of the camera FOV onto the apertures of the hub and rotary' top may be accomplished by adjusting the heights of the three screws to alter the pointing angle of the camera. FIG. 8 A shows the camera assembly 112 in the alignment frame 808 of the camera mount assembly 170 and the three screws 802a-c used to align the angle of the camera assembly 112 relative to the device housing. FIG. 8B shows the configuration where the camera mount 170 contains three magnets 810a-c situated in a triangle, depicted in FIG. 8C, around the camera central axis within the frame 808, with each magnet 810a-c situated at the bottom of a cavity' 806a-c. When in place, the screws 802a-c will magnetically attach to the magnets 810a-c and the angular position of the camera 112 is set by the depths of screws 802a-c. Adjustment of the screws 802a-c, as shown in FIG 8C, will alter the pointing angle of the camera assembly 112, with adjustment of either of the screw 802a to modify the y-rotation and / or screws 802b-c along one edge of the frame 808 to modify the x-rotation. Thus, during alignment, the screws 802a-c may be adjusted to vary the pointing angle of the so that the center of the FOV with the center of the apertures of the hub and rotary-. Translation is not required for this configuration because the initial alignment based upon the main housing features is adequate and only fine adjustment is needed, but in other variations, translation along the Z-axis may be accomplished via adjustment of all three screws 802a-c. This may improve the placement of the depth of field along the Z-axis to improve image focus and fix the extent of the FOV for a constant image resolution.

[0094] FIGS. 19Ato 19D depict another embodiment of fingerprint capture device 1900 that further comprises an optional optically transparent window structure or cover 1902 along the optical path or centerline 500 of the camera assembly 112. The other components of the device 1900 may be otherwise similarly provided and configured as with device 100 in FIGS. 1A to 1G, such as the aforementioned camera assembly 112, and the actuator 108, wired communication link or cable 18

[0095] 4921-1033-1530'1P324457.US.01 110, lens, light PCB 116, diffuser, camera aperture, aperture support 154, and kinematic camera mount and alignment assembly 170, for example.

[0096] As depicted in FIG. 19B and 19C, the optical cover 1902 may be attached to the rotary hub 1912, via a recess 1906. In other embodiments, however, the cover may be attached to mam housing rather than the rotary hub, by an annular or circumferential recess of the housing. The recess 1906 may be provided on annular or circumferential flange or support 1908 of the hub 1912 to position the cover 1902 more superiorly for easy cleaning. As depicted in FIG. 19B, the recess 1906 or support 1908 need not have the same angular orientation as the rotation plane of the hub 1912, e.g. the cover 1902 may partially reside above and / or below the rotation plane of the hub 1912 as depicted in FIG. 19B. This difference may help reduce reflection artifacts from the light source and / or ambient light, during use. The cover 1902 may help to protect the camera assembly 112 from dust or other contaminants, which may help to maintain long-term image quality. The cover 1902 may comprise a polymeric material such as a polycarbonate or a glass. The cover 1902 may be glued to the recess or form a mechanical interfit with the recess 1906, and a rubber or other polymeric seal may be provided between the cover 1902 and the recess 1906 to enhance sealing and / or retention of the cover 1902 to the housing 1904a / b.

[0097] The cover 1902 may be configured with light filtering properties for various wavelength ranges and / or polarity. The cover 1902 may include one or more coatings on the external and / or internal surfaces, e.g. hydrophobic and / or oleophobic coatings to make the cover resistant to water and / or fingerprints, and / or scratch resistance, and / or ant-reflective properties, to minimize flare and / or ghosting. The cover 1902 may comprise a generally planar material, but in other variations, the cover 1902 may have a concavity and / or convexity in order to provide magnification and / or other lens characteristics. The lens characteristics may complement or substitute for any lenses provided in the camera assembly 112. In the embodiment depicted in FIGS. 19A to 19D, the cover 1902 comprises a planar material w ith a center or average thickness of 8 mm, using standard glass. In other variations, and based on the t pe of material and its strength, the cover 1902 may have a center or average thickness in the range of 1 mm to 10 mm, 1 mm to 8 mm, or 2 mm to 6 mm. The cover may have a diameter of 30 mm, or a diameter in the range of 5 mm to 50 mm, 10 mm to 40 mm, or 25 mm to 35 mm. The cover surface area may be 700 mm2, but in other variations, the surface area may be in the range of 700 mm2to 900 mm2, 600 mm2to 800 mm2, or 650 mm2to 750 mm2

[0098] In the exemplary embodiment depicted in FIGS. 19A to 18D, the cover 1902 may be orientated at an angle of 11 degrees from the optical centerline 500 of the camera assembly 112. In other variations, the cover orientation angle may be in the range of 0 degrees to 45 degrees, 5 degrees to 30 degrees, or 10 degrees to 15 degrees from the optical centerline 500 of the camera 19

[0099] 4921-1033-1530'1P324457.US.01 assembly 112. The cover orientation angle relative to the plane of the rotation hub 1912 may be -30 degrees, but in other variations may be in the range of -45 degrees to +0 degrees, -40 degrees to -15 degrees, -35 degrees to -25 degrees, -30 degrees to +5 degrees, or -15 degrees to +0 degrees, for example.

[0100] Another optional feature of the fingerprint capture device 1900 is that the rotary hub 1912 may lack the center dome 166 of the rotary hub 122 that is depicted in FIG. 1 J, and therefore also lack the center magnet 144. Instead, the rotary hub 1912 of device 1900 in FIGS. 19A to 19D may utilize the perimeter magnets (not shown in FIGS. 19A to 19D, but otherwise configured similarly to those in FIGS. 1 A to 4L) of the rotary hub 1912 and rotary top 1914. While lacking a central dome, the rotary hub 1912 may still comprise an annular peripheral flange 1916 which the rotary top 1914 is seated on, and an inner projecting flange 1918 to be received by the inner cavity of the rotary top 1914. As depicted, the inner projecting flange 1918 may be comprise a variable or non-uniform projection height, as a result of the orientation angle of the cover 1902. As the rotary hub 1912 lacks a central dome, the rotary top need not have a central dome-like structure 1922, and may alternatively comprise a flat end cylindrical shape, frustoconical shape, or polygonal cross-sectional shape, for example.

[0101] The magnetic attachment also allows for easy removal of the camera assembly to adjust the three screws 802a-c and easy replacement to check alignment. Once aligned, the magnetic attraction betw een the magnets 810a-c if camera mount 170 and pedestal screws 802a-c will retain alignment of the camera long term without the need to secure the camera assembly 112 in any other way. This magnetic mount 170 also allows for the camera assembly 112 to be reproducibly removed for maintenance and reinserted without further alignment.

[0102] The kinematic fine alignment is useful to properly align the rotary top to the camera field-of-view. The alignment may facilitate any top fastened to the hub of the main housing to have the center of the field-of-view properly aligned with the aperture in place.

[0103] An accurate alignment of the camera with respect to the aperture may facilitate proper detection of what aperture the user has selected and has been placed in the FOV, and may reduce imaging processing requirements to correct imaging variations by providing physical reproducible alignment. To reduce complexity, the rotary tops may not have any positional sensors to detect what aperture is in place, and the camera may be used to detect what aperture is in place in realtime. In some variations, image processing can be used to detect the aperture in the camera FOV and may be used to identify which aperture is positioned, and the dimensions and other image characteristics may also be used to normalize or calibrate the camera assembly, the image on an image-by -image basis, and / or a per-subject basis. To indicate which aperture has been selected, different indicia or indicia locations may be provided on the interior surface of the rotary top to 20

[0104] 4921-1033-1530'1P324457.US.01 facilitate identification of the aperture positioned in the camera FOV. Such indicia may also be used to normalize or calibrate the camera assembly, the image on an image-by -image basis, and / or a per-subject basis. In some variations, a single white dot is positioned in a unique spot for each aperture, which may be identified easily and quickly with image analysis. Referring back to the schematic of FIG. 9A, the locations on the left of the dots 906a-h, one for each aperture 1 to 7. In this exemplary' embodiment, the dots 906a-h are all aligned vertically but at different locations, which may simplify detection and may also help to confirm alignment of the corresponding apertures 1 to 7. There are eight unique apertures in the current configuration, including one for the closed position. More (or less) apertures and dots can be used and different areas of the camera FOV can be exploited.

[0105] FIGS. 10A to 10C depict one exemplary top lOOOa-c where each aperture 1002a-c or closed position has a hole or cavity 1004a-c placed at a unique location in the rotary tops lOOOa-c, so that in the field of view resulting image 1006a-c in FIGS. 10D to 10F, a corresponding dot 1008a-c will result at along a vertical edge lOlOa-c (or other location) of the corresponding image 1006a-c. In this particular example, the holes 1004a-c are filled with a white silicone to create white “dots” that can be optically detected. Other methods can be used where dots are painted onto the surface, the tops can be 3-D prints in multiple colors, or physical pins can be placed to produce a pattern to be detected. Images of the current configuration are shown in FIGS . 10D to 1 OF for three different apertures 1012a-c. An image processing algorithm that detects dots is used and is active within the dotted area 1014a-c of the image 1006a-c, so that a detection is made only when the magnets have engaged, and the top is in place. FIG. HA depicts the dot detection area 1 lOOa-e for selected apertures of the rotary tops 104a shown in FIGS. 4A to 4D. Each of the five vertical images 1 lOOa-e shows the dot 1102a-e detected by the image processing algorithm for each aperture 106a-e and the closed position and is indicated by placing a detection box 1104a-e around it. The position along the vertical axis of the image 1 lOOa-e determines what aperture has been selected. The black horizontal lines 1106a-h indicate the expected potential positions of the dots for detection. The rightmost image 11 OOf shows all of the dots 1102a-e and boxes 1104a-e of that top overlaid onto a single image to illustrate that they are separated and distinguishable from each other. FIG. 11B shows the imaging data for the top 104b shown in FIGS. 4E to 4H, which has a different combination of apertures 106e-h and corresponding dot locations, resulting in images HOOf-j with dots and boxes 1102a / c / f / i / j and 1102b / c / f / i / j. In this particular embodiment, the smaller aperture on top 104b is identical in size to the largest aperture on top 104a, and therefore share the same dot location, as do both of their closed positions. Image 1100k depicts all of the dots and boxes 1102 a / c / f / i / j, 1104 b / c / f / i / j, respectively. FIG. 11C shows all the dots and the positions of detection for the 8 positions for these two sets of tops 104a, 104b, which include three 21

[0106] 4921-1033-1530'1P324457.US.01 unique apertures on the smaller top 104a corresponding to dots 1102e at location 1106c, dot 1102d at location 1106d, and dot 1102b at location 1106f, three unique apertures on the larger top 104b, corresponding to dot 1102f at location 1106h. dot 1102i at location 1106b, dot 1102j at location 1106a, and identical apertures 1102a at location 1106g, which is the largest aperture on top 104a and the smallest aperture on top 104b, and closed positions on each top 104a and 104b which have the same dot 1102c at location 1106e. In use, the user can then take either top 104a, 104b and place it onto the device 100 and it will detect the aperture 106a-h in place. The dot locations for the closed positions of each different top can be the same or different, so that the top attached to the device may be detected even when in the closed position.

[0107] Aside from identifying the rotary position and the aperture of the top, the optical detection of the dot is used in a number of ways to support the user in the collection of the fingerprints. One way the dot detection is use is to signify that the device is ready for collection. Once a dot is detected in the search box, the software control system will enable the ability to acquire an image by pressing the trigger on the device or via software, thus minimizing the collection of errant images when an aperture is not properly in place.

[0108] Another aspect of identifying the aperture in place is that the resultant images can be cropped with a binary mask specifically designed for a particular aperture. This requires substantially less computing power to apply compared to other image analysis and correction algorithms. Upon collection the specific aperture mask is used to remove the non-finger background and speed up processing by reducing the pixel count of the image. This position of the binary mask is fixed if the dot is detected precisely at the correct location. If required, the coordinates of the dots can be detected and the mask adjusted translationally and / or proportionally if the aperture is slightly misplaced. An example of this is shown FIG. 16A to 16D. FIG 16A show-s a raw image 1600 of a finger 1602 located in an aperture 1604, containing the indicia dot 1606, FIG. 16B shows the binary’ mask 1608 for that aperture 1604 used, FIG. 16C shows the resulting image 1610 of the finger 1602 after applying the mask 1608 to the raw image 1600 in FIG. 16A.

[0109] Another optional feature of identifying what aperture is in place is to facilitate consistent enlargement or “zoom” to the maximum size for that aperture. This may be helpful w hen scanning the smallest newborn fingers, where the features and alignment needs to be checked visually on the computer screen. Predetermined fixed limits on the display that correspond to each aperture and the resultant collected image may be presented to the user in a standardized size and zoomed into the finger based upon the aperture detected. FIG. 16D shows a zoomed -in or enlarged image 1612 of the finger 1602 as it would be presented to the user on a display.

[0110] 22

[0111] 4921-1033-1530'1P324457.US.01 Identification of the aperture size selected by the user also gives facilitates the potential determination of the finger size. If the finger size is determined initially, image processing can tune the age adjustment calculation for faster results.

[0112] Identification that the aperture is not in its expected place also allows the software to reduce computation by not performing certain unnecessary functions when one or more imaging expected characteristics are absent or not otherwise detected. For example, auto exposure functions would only occur when aperture is in place.

[0113] Other markings could also be used to show the size and current position of the aperture. FIGS 12 A to 12C, for example, shows a set of images 1200a-c of apertures 1202a-c where verti cal lines 1204a-c, 1206a-c can be printed or formed on the underside of the rotary top that can be optically detected and used to determine what aperture is within the FOV of the camera. The vertical lines 1204a-c. 1206a-c may be simpler to detect via imaging processing the distance between the vertical lines 1204a-c, 1206a-c may be used to determine the aperture size or corresponding aperture 1202a-c. Other top configurations not based on the rotary design can also be used to adjust the size of the aperture. A movable aperture can be used, where one side of the aperture is fixed and the other can be moved to adjust the size of the opening. In this case, lines and / or a dot can be optical detected to determine the size the aperture in real-time. Examples of various movable apertures are described in U.S. Pat. 10,496,870 and U.S. Pat. 11,003,883. Distinct barcodes or QR codes for each aperture could also be used and detected with the camera.

[0114] FIGS. 23 A and 23B illustrate another embodiment of a handheld fingerprinting system 2400, comprising a handheld housing 2402, an interface hub 2404 and a releasably detachable imaging top 2405. In this particular example, the top 2405 comprises a rotary top with a plurality of noncontact finger apertures 2407 for image capture. In contrast to the earlier embodiments described herein, the actuator 2408 for the system 2400, shown in FIG. 23B, is provided on a back surface 2410 of the housing 2402, rather than the front surface 2412, so that the actuator 2408 can be activated utilizing the user’s thumb rather than the user’s index finger for embodiments where the actuator is provided on the front surface. In other variations, the actuator may be located at any other location on the housing, or provided in a separate housing, a wired or wireless foot pedal actuator, or to auto-capture image(s). In other variations, multiple actuators may be provided, e.g., both a back surface actuator and a front surface actuator may be provided. A grip recess 2414 may still be provided on the front surface 2412 for the user’s index finger and / or middle finger to facilitate the gripping of the housing 2402. An optional additional feature of system 2400 is the retention projection or ledge 2416, which helps to resist inadvertent dislodgement of the imaging top 2406. The retention ledge 2416 may be located on the opposite side of the system 2400 from the selected or set imaging location, e.g. the ledge 2416 may be located at the front of the interface 23

[0115] 4921-1033-1530'1P324457.US.01 hub 2404, while the selected or single fixed imaging window 2418 of the top 2405 is positioned at the back of the interface hub 2404. At this opposing location from the imaging window 2418, the ledge 2416 may help support the imaging top 2405 as a person’s finger or digit is being imaged, and as a result may be applying downward pressure on the imaging top 2405, which may cause it to slide off from the interface hub 2404 but for the retention ledge 2416 blocking displacement in that direction. The retention ledge 2416 is offset from the interface surface of the interface hub 2404 so as not to interfere with the rotation of an imaging top, e g. the ledge 2416 is configured to clear any flanges 2419 projecting radially outward from the imaging top 2406, while also being configured to have minimal or no gap with any flanges 2419 to provide additional support to the imaging top 2406 during use.

[0116] The system 2400 depicted in FIGS. 23A and 23B may be configured for use with the same or similar exemplary rotary tops as depicted in FIGS. 1 A to 6D, except that the interface hub 2404 of system 2400 lacks a center axle or center magnet at the rotation axis of the tops, and only utilizes the circumferential peripheral magnets provided on the interface hub 2404. The center axle or magnet may not be required to sufficiently engage the rotary top to the interface hub 2404. The absence of the center axle or magnet also permits a larger the interface hub 2404 to comprise a larger imaging opening, which may allow the system 2400 to accommodate capture of larger images and / or to accommodate additional imaging components into the imaging top 2405.

[0117] In some further embodiments, the system may include an imaging top that is configured to perform contact fingerprint capture using an imaging window or aperture that includes a platen or prism. System 2400 in FIGS. 24A to 24C, for example, is depicted with a different releasably detachable top 2406 that holds a prism at the imaging window 2418. In this particular example, due to the size of the prism, only a single imaging window 2418 is provided, with prism housing 2422 protruding from the top 2406 to provide sufficient space to retain the prism. Thus, although top 2406 includes a plurality of flanges 2020 like that the rotary multi-aperture tops, this particular embodiment of a top 2406 does not rotate and thus flanges 2020 are optional and not needed to facilitate rotation. The configuration of the prism top 2406 allows the use the existing imaging assembly of the system 2400 to capture contact fingerprints from contact with the prism, without a dedicated imaging system specifically tailored for use with contact-based fingerprint imaging. Also, although the prism surfaces comprises flat rectangular surfaces, and the imaging window 2418 depicted in FIGS. 24A to 24C are rectangular, in other variations, the imaging window may have a different shape, e.g., oval, circle, or other polygonal shape.

[0118] Referring to FIG. 20 A, which schematically depicts a fingerprint capture system 2000 with an imaging assembly 2002 and an image capture prism 2004, the imaging assembly 2002 comprising a field-of-view 2006, focal plane 2008 and imaging axis 2010. The prism 2004

[0119] 24

[0120] 4921-1033-1530'1P324457.US.01 comprises a base surface 2012, a first lateral surface 2014 configured to capture images, and a second lateral surface 2016, which here is configured with a light absorbing material 2018, which may improve image contrast and quality by reducing extraneous light. In other variations, a light reflecting matenal may also be provided, or may be provided without any material, which may help reflect light back toward the finger and result in bright ridges and dark valleys. Although the prism 2004 depicted in FIG. 20A is a triangular prism, in other variations, a porro prism or trapezoidal prism, or a group of prisms may be provided. As depicted in FIG. 20 A, the base surface of the prism 2004 may be generally orthogonal to the imaging axis 2010 to capture surface 2012, and where the imaging axis is generally aligned with the center of the base surface 2012. Depending on the size of the field of view and the depth of field of the imaging assembly 2002, the captured image of the digit 2020 or other body part may be limited in the amount of image captured from the lateral surface 2014, and / or capture other structures, e.g., the second light blocking lateral surface 2016. The image may be masked in post-processing to omit or ignore non-essential sections of the resulting image. Some potential issues with the configuration in FIG. 20A is that the imaging assembly 2002 may require a greater depth of field because of orientation of the first lateral surface 2014 relative to the focal plane 2008, which exhibits relatively greater deviation from the focal plane 2008 proximally and / or distally.

[0121] FIG. 20B schematically depict another variant of a fingerprint capture system 2050 with an imagine assembly 2052 and an image capture prism 2054, wherein imaging assembly 2052 comprises a field-of-view 2056, focal plane 2058 and imaging axis 2060. In this configuration, the prism 2054 is rotated or angled in orientation, and / or shifted in lateral and / or longitudinal position or orientation, such that at least the base surface 2062 and / or the first lateral surface 2064 of the prism 2054 lies within the field-of-view 2056. In some variations, at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, or 98% of the base surface 2062 and / or first lateral surface 2064 lies within the field-of-view 2056. In some further variations, none of the second lateral surface 2066 may be in the field-of-view 2056, or at less than 20%, 15%, 10%, or 5% of the surface area of the second lateral surface 2058 or its blocking material 2068 is visible. In some variations, the base surface 2062 may be at an angle, relative to an orthogonal plane of the imaging axis 2060, in the range of 20 to 60 degrees, 30 to 50 degrees, 35 to 45 degrees, or 35 to 40 degrees, for example. The imaging axis 2060 may intersect or may be offset from the center of the base surface 2062 and / or the first lateral surface 2064. The first lateral surface 2064 or outer prism surface configured to capture the image of the finger 2070 or other body surface may be oriented with an angle of incidence relative to the imaging axis 2060 of the imaging assembly 2052 that is less than 42 degrees (the nominal critical angle for glass / air interfaces), or in the range of 10 to 30 degrees. 15 to 25 degrees, or 20 to 25 degrees. Furthermore, the configuration depicted in FIG. 20B illustrates that deviation in 25

[0122] 4921-1033-1530'1P324457.US.01 distance of along the first lateral surface 2064 from focal plane 2058 is reduced compared to that in FIG. 20A, which may provide better focus and image quality7, or allow the use of an imaging assembly with a narrower depth of field. Like other systems described herein, the second lateral surface 2066 may comprise no coating, a light reflecting matenal, or a light absorbing material 2068.

[0123] FIGS. 21 A and 21B also depict the effect of prism orientation with respect to lighting of the finger 2020, 2070 with regards to light sources 2022, 2072 that surround the imaging assembly 2002. 2052. In the prism orientation depicted in FIG. 21A, which corresponds to the prism orientation in FIG. 20 A, the light sources 2022 emit light from the same side or general direction as the imaging assembly 2002. This can result in a significant amount of light reflecting off of the base surface 2012 and back toward the imaging assembly 2002, which may reduce image contract or quality. In contrast, in FIG. 2 IB, which corresponds to the imaging assembly 2052 and prism 2054 of FIG. 20B, a light baffle 2072 may be provided along the field-of-view 2056, which may block some of the reflected light from the light sources 2072 that would otherwise reflect off of the base surface 2062. The light baffle 2072 may be located on the same or position as the farthest edge 2074 of the base surface 2062 of the prism 2054, and may be angled toward the imaging assembly 2052, relative to the vertical or imaging axis 2060 at an angle in the range of 0 to 40 degrees, 5 to 35 degrees, 10 to 30 degrees, or 15 to 25 degrees, or 15 to 20 degrees, for example. In some variations, the orientation angle of the light baffle may be parallel to the outer edge of the field-of-view 2056.

[0124] FIG. 22 illustrates another exemplary embodiment of an imaging assembly 2202 and an angled prism 2204, and wherein the imaging assembly 2202 comprises a field-of-view 2206, focal plane 2208 and imaging axis 2210. In some variations, the base surface 2212 of the prism 2204 may be at an angle A, between the base surface 2212 and an orthogonal plane 2224 to the imaging axis 2210, in the range of 20 to 60 degrees, 30 to 50 degrees, 35 to 45 degrees, or 35 to 40 degrees, for example. The imaging axis 2210 may intersect or may be offset from the center of the base surface 2212 and / or the first lateral surface 2214. The first lateral surface 2214 or outer prism surface may be oriented with an angle of incidence B between the orthogonal axis 2226 of the first lateral surface 2214 and imaging axis 2210 of the imaging assembly 2202 that is less than 42 degrees (the nominal critical angle for glass / air interfaces), or in the range of 10 to 30 degrees, 15 to 25 degrees, or 20 to 25 degrees. The first lateral surface 2214 or outer prism surface may have an orientation angle, relative to the orthogonal plane 2224 of the imaging axis 2210, that is in the range of 10 to 40 degrees, 15 to 35 degrees, or 20 to 30 degrees. In some variations wherein the prism 2204 is a triangular prism, the prism 2204 may have:

[0125] 26

[0126] 4921-1033-1530'1P324457.US.01 A) An angle X between base surface 2212 and the first lateral surface 2214 that is in the range of 60 to 65 degrees, 55 to 70 degrees, or 50 to 75 degrees, for example.

[0127] B) An angle Y between the first lateral surface 2214 and the second lateral surface 2216 that is in the range of 45 to 55 degrees, 40 to 55 degrees, or 45 to 60 degrees, for example. C) An angle Z between the base surface 2212 and the second lateral surface 2216 that is in the range of 65 to 70 degrees, 60 to 75 degrees, or 55 to 80 degrees, for example.

[0128] D) A base surface length XZ that is in the range of 0.95 to 1.0 inches, 0.90 to 1.1 inches, or 0.80 to 1.2 inches.

[0129] E) A first lateral surface length XY that is in the range of 1.2 to 1.3 inches, 1.1 to 1.4 inches, 1.0 to 1.5 inches or 0.9 to 1.5 inches.

[0130] F) A second lateral surface length YZ that is in the range of 1.1 to 1.2 inches, 1.0 to 1.3 inches, 0.9 to 1.4 inches.

[0131] Per the geometric constraints of a triangular prism, the prism include any two out of the three angle X, Y, Z ranges, or any two out of the three surface length XZ, XY, YZ, to derive the geometry of the prism. In some variations, the imaging assembly may be configured with a focal plane that is in the range of 45 to 50 mm. 40 to 50 mm, 45 to 55 mm, or 40 to 70 mm. The depth of focus at the focal plane may nominally be from the imaging assembly, The exposed surface of the prism, e.g. the imaging window may have a window length L on the cross section depicted in FIG. 22 in the range of 20 to 25 mm, 18 to 27 mm, 15 to 30 mm. The window width W (not shown) may be in the range of 15 to 20 mm, 12 to 22 mm, 10 to 25 mm, or 15 to 22 mm, or 15 to 25 mm. The longitudinal distance spanned by the imaging window along the imaging axis will depend on it orientation angle, and may be in the range of 7 to 11 mm, 6 to 12 mm, or 8 to 12 mm. The geometries recited above may be used fingerprint capture compliant with the FAP20 (Fingerprint Acquisition Profile) where the fingerprint image size is 300 x 400 pixels, or a fingerprint image that is nominally 0.8 x 0.6 inches. Other fingerprint image profiles include FAP10 (296 x 354 pixel images, or .65 x 0.5 inches) and FAP 30 (400 x 500 pixel image, or 1.0 x 0.8 inches). In some variations, the imaging window size provided may be different, depending on the FAP profile.

[0132] Referring back to FIGS. 24A to 24F, system 2400 is depicted with a detachable prism top 2406 attached to the interface hub 2404. A prism 2450 located at the imaging windows 2418 and located in the prism housing 2422 protruding from the top 2406. In this particular example, the prism housing 2422 has a similar triangular shape as the prism 2450, but in other variations with other prism configurations, the prism housing may comprise a similar shape. In still other variations, the attachable top may comprise an enlarged large shape that does not depict, track or conform the general shape of the prism.

[0133] 27

[0134] 4921-1033-1530'1P324457.US.01 FIG. 24F is a top view of the system 2400, depicting the prism top 2406, prism 2450, imaging window 2418 and prism housing 2422, positioned on top of the interface hub 2404 and abutting the ledge 2416 of the hub 2404. Referring to FIGS. 24G to 25C, prism top 2406 comprises an upper top shell 2452 and a lower top shell 2454, wherein the prism 2450 is retained by being sandwiched between the two shells 2452, 2454, which in turn is secured by a fastener 2456, e.g., screw or bolt. In other variations, however, the top 2406 may comprise a unitary7design, with the prism retained by clips, rotating locking arms, or adhesives, for example. The same prism attachment mechanisms may be used with a multi-component prism top as well.

[0135] FIG. 24G depicts the system 2400 with the upper top shell of the prism top 2406 omitted. The lower top shell 2454 is depicted with a lower prism housing 2458 and lower prism opening 2460 through which the imaging assembly 2466 is visible, along with some of the light sources 2462 of the system 2400. The lower prism opening 2460 is partially surrounded by a light baffle 2464 that extends from the opening 2460 toward the imaging assembly 2402. FIG. 24H depicts the system 2400 with both the upper and lower top shells 2452, 2454 removed, to illustrate the additional light sources 2462 that are blocked by the light baffle 2464. FIG. 24G also depicts the magnet retention cavities 2470 located in the flanges 2420 of the prism top 2406 that interface with the corresponding magnets in the interface hub 2404. In other embodiments, however, a nonmagnetic mechanical attachable / detachable interface may be provided between the tops and interface hub, e.g., segmented circumferential flanges may be releasably engaged with circumferential tabs to provide a mechanical interface. Furthermore, for the prism top 2406, which only has a single imaging window 2418 or aperture and therefore does not need to rotate, the top may be provided with additional mechanical interfit structures to facilitate proper alignment and attachment of the prism top to the interface hub 2404. For example, the prism top may be provided with an additional engagement structure, such as a ledge cavity or cap, which must be aligned with the ledge of the interface hub 2404 to ensure proper alignment and engagement.

[0136] As depicted in FIGS. 241, 24J, 25B, 25C, 26A to 26E, the light baffle 2462, comprises a vertical wall 2472 extended downward from the side of the lower top shell 2454 that is tilted farther away from the imaging assembly. In this particular example, the vertical wall 2472 is partially annular wall, covering the back region and partially the side regions of the field of view of the imaging assembly. The vertical wall 2472 extends all the down to protective window 2468 of the interface hub 2404, wherein optional horizontal flanges or walls 2474 may be provided extending radially outward from the ends of the vertical walls 2472 to provide additional light blockage. While the vertical and horizontal walls of the light baffle may be configured with tight tolerances with respect to the protective window 2468, if there are variations in the initial attachment of the prism top 2406 where the protruding light baffle 2464 may impinge transiently impinge on the 28

[0137] 4921-1033-1530'1P324457.US.01 protective window 2468, a gap of 1 to 10 mm, 2 to 8 mm or 3 to 6 mm may be provided to minimize any transient impingement. In other variations, the light baffle may comprise a light blocking soft silicone, in order to reduce any damage from inadvertent impingement. This light blockage from the baffle 2464 may also be in addition to the backing material provided on the prism, e.g. the second lateral surface of the prism. In other variations that lack the protective window 2468, the light baffle 2464 may extend further toward the imaging assembly 2402 or light sources 2462. FIGS. 241 and 24J depict the general arrangement of the imaging assembly, interface hub 2404, prism top 2406. The prism 2450 and corresponding top 2406 may comprise any of the variations of prisms described with regards to FIGS. 23A and 23B, with the corresponding structure of the top 2406 to conform to the selected prism geometry and pose. As noted previously with respect to FIG. 21B, the light baffle 2464 may comprise a vertical wall 2472 that may be angled toward the imaging assembly, relative to the vertical or imaging axis at an angle in the range of 0 to 40 degrees, 5 to 35 degrees, 10 to 30 degrees, or 15 to 25 degrees, or 15 to 20 degrees, for example.

[0138] FIGS. 25A top 25C also depict the lower annular surface 2480 and inner annular surface 2482 of the interface hub that 2404 forms a complementary interfit with the rotatable and prism tops configured for use with system. This includes the corresponding lower annular surface 2484 of the lower prism top shell 2454, and the annular wall opening 2486 which corresponds to the inner annular surface 2482 of the interface hub 2404. A cover frame 2488 is also provided to hold the protective cover 2468. FIG. 25C also depicts the attachment tabs 2476 found on the upper prism top shell 2452 which help to align the upper prism top shell 2452 with the lower prism top shell 2454.

[0139] FIGS. 27A to 27D depicts the image processing that may be performed with fingerprints captured via the contact or prism top. After the raw image 2700, depicted in FIG. 27A, is captured, the image 2708 may be cropped or masked, as depicted in FIG. 27B, to remove any unnecessary image regions, e g. the prism apex 2706 formed at the junction of the first and second lateral surfaces 2702, 2704, as well as part of the first and second lateral surfaces 2702, 2704 which is not visible from the imaging window of the top. The image 2708 may also undergo some initial correction of brightness and / or contrast. After this processing the image 2708 may also undergo inversion, resulting in an image 2710 depicted in FIG. 27C, wherein the ridges inverted from white to black, for consistency with fingerprint databases. The fingerprint image 2712, as depicted in FIG. 27D may also undergo distortion correction or keystone correction that may result from the angled position of the prism and the angled capture surface relative to the imaging axis of the imaging assembly, wherein the closer regions of the fingerprint scan are larger than the distant regions of the fingerprint scan, as schematically depicted in FIGS. 20A to 2 IB.

[0140] 29

[0141] 4921-1033-1530'1P324457.US.01 FIG. 18 shows an overview of the system operation and software architecture 1800. Specifically, this flowchart shows the process 1800 for the collection of a single image of a finger and would be repeated for each finger, as desired by the operator. It shows that during collection, the raw image is streamed 1802, and other processes will only start upon detection of an aperture dot 1804. Once a dot is detected, other processes are initiated, such as exposure control 1806 and trigger activation 1808. Once atrigger is detection for collection 1810, the image is acquired 1812 processed to the desired image resolution in pixel per inch (PPI), processed for quality, and displayed back to the user. This process includes the application of the mask 1814, contrast enhancement 1816 and pixel / ridge analysis 1818. If a desired PPI level 1820 is provided, and the image is converted 1822 to the desired PPI. Fingerprint analysis 1824 is then performed on the converted image and various characteristics and score 1826, e.g. binary' image quality score and number of minutiae, may be generated and displayed 1828. along with the processed and / or raw image. A second trigger push 1830 will restart the process.

[0142] For Infants and small children, the biometrician needs to physically place and align the finger onto the device without assistance from the subject. Due to the need to assist the subject, it is helpful that the device be operable with a single hand, freeing the second hand for placement and proper alignment of the subject’s finger on the device.

[0143] The device is also designed symmetrically, so that it can be operated identically by right-handed or left-handed users. Specific designs that make it easier to operate specifically with one hand may be designed such that external features of the device are molded specifically for use with one hand or the other. Having specific left and right handed devices may be more comfortable to the user.

[0144] One feature of the device operation is the ability to acquire fingerprint images over a wide range of ages and finger sizes. Industry standard fingerprint devices are not used to collect images of children for several reasons: 1) the optical resolution of a standard fingerprinter is not detailed enough to detect the smaller ridge features, and 2) the child grows over time and the fingerprint image will be inconsistent and change over time.

[0145] Children fingerprint ridge features are very' small and standard fingerprinter devices have an image resolution of 500 pixels / inch (PPI), with some newer models increasing to 1000 PPI. This resolution is sufficient to image the ridges of an adult fingerprint.

[0146] Regardless of whether the adult image was collected at 500 PPI or 1000 PPI, the standard fingerprint processing algorithms require that the images have 500 PPI resolution, since the image processing algorithms have all been trained on images of that resolution and most of the fingerprints in fingerprint databases were scanned and saved at that resolution.

[0147] 30

[0148] 4921-1033-1530'1P324457.US.01 For an adult, the distance between fingerprint ridges on adult fingers is about 400-500 microns, therefore 500 PPI, which has a sampling distance of 50 microns, will place 8-10 pixels between adjacent ridges. Children, on the other hand, have the same number of ridges. The child fingerprint is fully formed, but the ridges are distributed across a smaller finger that changes with age, thus the ridges are closer together. The smallest newborns may have only 125 microns between ridges and the 500 PPI imagers cannot adequately distinguish between adjacent ridges with only 2-4 pixels sampling. In addition, the image processing algorithms used in standard fingerprint devices expect there to be 8-10 pixels between ridges, thus the image processing algorithms that detect and enhance the contrast of the ridges will fail and incorrectly evaluate the children’s image. In addition, as the child grows and the locations of the fingerprint minutiae locations will change over time, a newborn fingerprint will change enough that it will not match the fingerprint of the older child.

[0149] These issues are addressed by the device design by having both a high resolution imager and an image processing algorithm that corrects for the changing size of growing children. In order to have 10 pixels between the ridges of an infant, the image size of an individual pixel at the image plane needs to be -12.5 microns, which corresponds to a resolution for the image of -2000 PPI. The current device exceeds 3000 PPI to ensure that the small details of the child finger can be resolved.

[0150] Since the age and size of the fingers vary for individual and they change over time, the image processing conducted here will normalize all images to a constant number of pixels between each fingerprint ridge. Image processing algorithms are used to evaluate the average distance between ridges of each finger and then the image is resampled to place 8-10 pixels between ridges and create an image that has a 500 PPI “adult equivalent” image that standard fingerprint biometric image enhancement systems can evaluate. All different finger sizes are resamples to have the same pixels between ridges, regardless of the original size of the finger.

[0151] For example, FIGS. 13A to 13F depict images of fingers of different subjects of different ages and sizes. FIG. 13A is an infant finger that has -20 pixels between each ridge of the fingerprint. FIG. 13B is an infant that has -24 pixels between each ridge of the fingerprint. FIGS.

[0152] 13C through 13E have 28, 32 and 36 pixels between each ridge, respectively. FIG. 13F is that of an adult and there are 40 pixels between each ridge.

[0153] The size differences may be addressed by producing fingerprint images at high resolution and down sampling to a standard 500 PPI equivalent image so that the fingerprint is normalized to a single size. FIG. 14A shows an image of an infant finger, FIG. 14B is a finger image of a 1 year old child and FIG. 14C is an image of an adult finger, each shown with their proper relative sizes with respect to each other. In order to evaluate images like these that have vastly different sizes,

[0154] 31

[0155] 4921-1033-1530'1P324457.US.01 the fingerprints are normalized to a standard 500 PPI image, where there are 8-10 pixels between each fingerprint ridge. The result of doing that ty pe of process is shown by the processed images in FIGS. 14D, 14E and 14F for the newborn, 1 year old and adult respectively. In FIGS. 14D to 14F, all of the finger sizes have been normalized to a consistent resolution. After normalizing, the various sized fingers are resampled and the resultant minutiae map for the prints may be identically sized regardless of the starting age.

[0156] The minutiae location map will expand as the child grows and researchers have developed mathematical models that can be used to correct for the age (and size) difference as the child grows. If an initial fingerprint was taken when the child was 1 year old and the second fingerprint is taken when the child is six years old, these models may be used to attempt to extrapolate or "grow" the earlier fingerprint minutiae template 5 years to attempt to match the later image. The growth factor is often an average of data taken for a group of children. This averaging, may be problematic in that children do not grow7at the same rate or are the same size at any given age.

[0157] Some exemplary image processing methods directly measure the ridge distance or infer the density of ridges for each individual finger of the child in real-time. Some existing algorithms may utilize an average distance based on the age or age band of the child to correct the image. In some embodiments of the fingerprinting herein, however, the size of the specific finger for that child is measured and resampled to a consistent 500 PPI “adult equivalent”. This is done for the same child or person regardless of image, and each is brought to the same nominal pixel / ridge value of 8-10 pixels per ridges, as shown in Figure 11. based on the image properties rather than reported child age. In this method, all finger images are brought to a known pixels / ridge, regardless of the age or size of the child, thus counteracting issues associated with assuming a child is the average size. This may be performed on an image-by-image basis, or may be calculated once per subject and reapplied to each subsequent image of that subject with repeating the PPI normalization process.

[0158] On a standard contact-based fingerprinting device, the finger can be placed onto the platen and rolled to collect data across the entire surface of the finger, often referred to as Nail-to-Nail (N2N). For non-contact device, using a single camera, this may not possible or easy to perform, but in some variation, multiple images of the finger may be taken from multiple angles by directing the subject and / or user to rotate the finger appropriately. The multiple images could then be stitched together to create an N2N composite image. This can be accomplished with the standard aperture or with a N2N custom aperture that helps the user align and rotate the finger to collect the image data.

[0159] In order to assist the user to collect the highest quality imagery', the device can provide feedback during collection to guide the user with respect to various image characteristics and the adequacy of the acquired image(s). One exemplary method is to utilize one or more core detection 32

[0160] 4921-1033-1530'1P324457.US.01 algorithms that mark the image to show the user where the fingerprint core is. For non-contact imaging, the curvature of the finger is a variable that can make enrollment and matching potentially difficult or challenging. Some data shows that the matching performance when the finger image and the verification finger image have the cores closely aligned may be helpful. One way to ensure this is to always have the images collected with the core at the center and / or direct the user to have multiple pictures collected where the core is in additional, well-defined locations. In some variations of the system, a standard collection procedure would guide the user to collect the multiple positions by tracking the position of the core and provide feedback that shows when the images needed have been collected. This can be accomplished by providing an image overlay with fiduciaries where the user needs to align the core of the subject's finger. Once an image has been collected that satisfies the core position required, the fiduciary mark can be changed to indicate that the position image has been collected and they can move to the next location. FIG. 17A shows a raw image of a finger with the automatic detection of a core 1700 shown by a box 1702, and FIG. 17B shows a group of five potential locations 1704 that is suggested to the user to position the core during image collection.

[0161] Another exemplary and optional quality feedback process that can be implemented involves detection of the pressure that the finger is exerting onto the device. As the user and subject place the finger onto an aperture, in some image acquisition processes it may be preferred if the finger is gently touching the aperture. If the finger is pushed against the device too hard, there is a tendency for the finger to be pushed through the aperture, resulting in stretching of the skin. When the skin is stretched, the ridges and valleys become less distinct and the contrast between the two are reduced. This will make it more difficult to analyze the image for ridge endings and bifurcations (i.e. minutiae). The image processing algorithm can potentially provide feedback on pressure in several ways. One is by image processing that looks for an increase in the pooling of blood in the center of the finger, based on the color or relative color change in the pixels, or light level or relative light level change in the pixels. As the finger pressure increases, the flow of blood is restricted and there will be a pool of blood located in the center of the finger surrounded by a reduction in blood at the finger / aperture contact point. That can be optically detected by evaluating the contrast in the image over the finger. Other methods can be exploited that detects the blood directly with spectral analysis, much like what is used in a pulse oximeter, but over the finger image to detect this pressure effect. Too high a pressure can be inferred by observing the contrast of the image in real-time. When contrast (between the ridges and valleys of the fingerprint) is significantly reduced, w e can provide feedback to the user to suggest lowering the pressure placed on the device.

[0162] 33

[0163] 4921-1033-1530'1P324457.US.01 In product testing, it has been identified that fingerprint capture device depicted in FIGS. 1 A to 1G may exhibit up to a 50 to 60 pixel shift from the nominal image center, which is hypothesized to be the result of imprecise alignment of the undulating rotational interface. While a 50 to 60 pixel variation or shift represents less than a half or about a one-third millimeter variation in alignment in a 4000 ppi imaging system, some additional processing power is required to correct for the image variation / shift. In some other variations of the fingerprint capture system described herein, the rotational interface or mounting interface between the device body / handle and the removable top may comprise complementary vertical alignment surfaces between the hub and top that can facilitate more precise or reproducible alignment at the interface. In testing, reduced pixel variance of no more than 5 to 6 pixels have been achieved with such interface configurations. In other similar interfaces, up to 90%, 95%, 96%, 97%, 98% or 99% of acquired images may have image shifts less than or equal to 30 pixels. 25 pixels, 20 pixels, 15 pixels, 10 pixels, pixels, 8 pixels, 6 pixels, 5 pixels horizontal variance. To incorporate the vertically oriented alignment surfaces while still permitting rotation of multi-aperture tops when attached to the device, an angled or ramped surface may be provided to facilitate the separation of the complementary vertical alignment surfaces, to allow rotation in one direction (i.e. clockwise or counterclockwise) to separate the vertical alignment surfaces and switch to a different alignment of the vertical alignment surfaces.

[0164] FIGS. 28A to 28L depicts another embodiment of a biometric capture system 2800, which can have a similar components as the fingerprint capture systems 100, 1900, 2400 and their subcomponents, e.g., as depicted in FIGS. 1A to 8C, 10A to 10C, 19A to 26E, except that instead of an undulating interface between the rotation or interface hub (i.e., not rotating when used with adult or prism tops) and the top or set of tops configured for use with the capture system, the exemplary biometric capture system 2800 comprises a different interface hub structure 2802 that forms a ratchet-like interface with one or more rotating or non-rotating imaging tops 2808. In the example depicted in FIGS. 28A to 28L, the interface hub 2802 comprises an alternating arrangement of ramp surfaces 2804 and stop surfaces 2806, while the imaging top 2808 comprises a complementary arrangement of ramp surfaces 2810 and stop surfaces 2812. In this particular example, the imaging top 2808 is a multi-aperture imaging top 2808 with five apertures 1814a-e, and thus is configured with 5 aligned configurations, provided by the five ramp surfaces 2804, 2810 alternating with five stop surfaces 2806, 2812 on the interface hub 2802 and imaging top 2808. The angle of the ramp surfaces 2804, 2810 may be less than or equal to 5 degrees, 4 degrees, 3 degrees, 2.5 degrees, 2.25 degrees 2 degrees. In the particular example depicted herein, the ramp angle may be in the range of 2 to 3 degrees, or 2 to 2.5 degrees. The stop surfaces 2806, 2812 may have a 90 degree orthogonal orientation relative to the plane-of-best-fit through the interface surfaces, but in other variations may form an acute angle between the stop surface 2806, 2812 and 34

[0165] 4921-1033-1530'1P324457.US.01 the ramp surface 2804, 2810, respectively. This acute angle may be offset from the 90 degree orientation up to 0.5 degrees, 1 degree, 1.5 degrees, 2 degrees, 2.5 degrees, 3 degrees, 3.5 degrees, 4 degrees 4.5 degrees, 5 degrees, 6 degrees, 8 degrees, 10 degrees, or 15 degrees, for example. The absolute maximum height of the stop surface 2806, 2812 may be 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.8 mm, 2 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm or 3 mm, for example.

[0166] In this particular example, the ramp surfaces 2804 of the interface hub 2802 angle from low to high in the clockwise direction, with the stop surfaces 2806 also facing the clockwise direction, thereby facilitating clockwise rotation of the top 2808 when changing apertures 2814. while resisting counter-clockwise rotation. The corresponding complementary ramp surfaces 2810 and stop surfaces 2812 on the imaging top 2808 will have the same orientations if characterized from an inferior en face frame of reference, but the opposite in the same absolute or in situ frame of reference as the hub 2802. In other examples, the opposite orientation may be provided to confer a counterclockwise orientation, e.g. ramp surfaces of the interface hub are angled from low to high in the counter-clockwise direction, with stop surfaces of the hub also facing in the counterclockwise direction, with the ramp surfaces and stop surfaces of the imaging top having the same orientation in the en face frame of reference but the opposite orientations in the same or in situ reference frame as the hub.

[0167] In some further variations, the ramp angle or stop angle geometry may be different between the inner radial regions and outer radial regions of the ramp surfaces 2804, 2810 and stop surfaces 2806, 2812, or between the interface hub 2802 and the imagine top 2808. These differences may help to facilitate the manufacturing of the components and / or reduce cohesion and / or friction effects between the components during rotation. For example, in some variations, the ramp angle and stop surface height in the inner radial region of the hub and top may be reduced compared to the outer radial region. The reduction may be characterized in absolute or relative terms. The inner height of the inner radial end 2806a of the stop surface 2806 may be reduced relative to the outer radial end 2806b by up to 0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm. 0.30 mm. 0.35 mm, 0.4 mm, 0.45 mm, or 5 mm, or reduced by up to 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45% or 50%, for example. The geometry' of the inner radial end 2812a and outer radial end 2812b off the stop surfaces 2812 of the top 2808 may be similarly configured in complementary' fashion.

[0168] Referring to FIGS. 28F to 281, the plurality of hub magnets 2020 and the plurality of top magnets 2022 may be located about the stop surfaces 2806, 2812, respectively. In some variations, the alignment axis between the hub magnets 2020 and the top magnets 2022 may also be aligned with the angle of the stop surfaces 2806, 2812, but in other variations, the alignment axis 2024 of the magnets 2020, 2022 may be tilted or angled relative to the alignment plane 2026 of the stop surfaces 2806, 2812. In the particular example depicted in FIGS. 28F to 281, the alignment axis 35

[0169] 4921-1033-1530'1P324457.US.01 2024 is tilted about 15 degrees from the orientation of the stop surfaces 2806, 2812, with the hub magnets 2020 tilted away from its stop surface 2806 and the top magnet 2022 also tilted away from its stop surface 28012. This orientation introduces a greater horizontal magnetic attraction force between the stop surfaces 2806, 2812, thereby increasing the precision or reproducibility of the alignment between the hub 2802 and top 2808. Although the magnets could be configured to be at other circumferential locations along the interface between the hub 2802 and top 2808, the location at the stop surfaces provides more space to tilt the magnets 2020, 2022 without having to increase the separation distance between the magnets 2020, 2022, which would be needed if the magnet were positions along the ramp surfaces 2804, 2810 of the hub 2802 and top 2808. In other variations, the alignment angle of the magnets relative to the stop surface angles may be offset by up to 2.5 degrees, 5 degrees, 6 degrees, 7 degrees, 8 degrees, 9 degrees, 10 degrees, 12 degrees, 15 degrees. 18 degrees, 20 degrees or 25 degrees, for example, or any range between any two of these values. Also, note that the magnets of the hub and the magnets of the top may have the same or different size or shape. In some variations, the plurality of hub magnets may be larger than the plurality of top magnets. This increase in hub magnet size may provide a larger attraction force using asymmetrically sized groups of magnets, by accommodating larger magnets in the hub because the hub has more available space, compared to the imaging tops.

[0170] Referring now to FIGS. 28B, 28D, 28J and 28L, in some variations of the biometric capture system, the system may comprise a set of imaging tops for imaging different patient sizes or different imaging modalities, and configured to accommodate both rotatable imaging tops and non-rotatable imaging tops, such as the exemplary prism top depicted in FIGS. 25A to 26E. Because the prism top 2454 only has a single orientation relative to the system body or handle, the prism top and other non-rotatable tops may be configured to be compatible with the portion of the rotation interface provided in the interface hub 2802, i.e. configured to fully seat onto the interface hub in its intended single orientation, but need not actually accommodate any rotation. This can be achieved by providing additional interface features for single orientation tops, where the additional interface features do not interfere with the functionality of rotatable tops when paired with the system. These additional interface features or structure may be located in or along the rotational interface, and / or may be offset or spaced away or adjacent to the rotational interface.

[0171] Referring still to FIGS. 28B. 28D. 28J and 28L. in this exemplary configuration of a biometric capture system 2800, the interface hub structure 2802 comprises a first opening 2830 located in a ramp structure 2804 and a second opening 2832 located apart from any ramp structure 2804 or stop surface 2806, but instead located on an outer lip or flange 2834 of the hub structure 2802. The second opening 2832 may have a different shape or size from the first opening 2830. This may help the user correctly orient the non-rotating tops by matching aligning different size 36

[0172] 4921-1033-1530'1P324457.US.01 or shaped projections on the bottom surface of non-rotating top to the first and second openings 2830, 2832 on the interface hub structure 2802. In this particular example, the first opening 2830 comprises a circular shape, while the second opening 2832 comprises an oblong shape. In alternate variations of a biometric capture system, all of the openings may be located on the ramp surfaces, or all of the openings may be located on flanges away from the ramp surfaces. In still other examples, 3, 4 or 5 openings may be provided, to correspond to 3, 4 or 5 projections on the nonrotating top. In still other variations, not all of the openings may be utilized by every non-rotating top configured for use with biometric system. In some other variations, some of the openings may contain electrodes that may may electrically connect to non-rotation top to provide powered features located in the non-rotation top.

[0173] FIGS. 29A to 29H depicts another configuration of the biometric system in FIGS. 28A to 28L, wherein the multi-aperture rotation top has be swapped out with a non-rotating top 2850 with a single larger aperture configured to acquire contact fingerprints from larger individuals, i.e., adults. This non-rotating top 2850 includes a lower interface structure 2852 with the complementary ramp surfaces 2854 and complementary stop surfaces 2856 to the corresponding ramp surfaces 2804 and stop surfaces 2806 of the interface hub 2802 of the system 2800. In addition, the lower interface structure 2852 includes a pin 2858 located on one of its ramp surfaces 2854 and another pin 2860 located on a raised flange 2862. The top 2850 is configured to align to the interface hub 2802 by insertion of the ramp pin 2858 into the first opening 2830, while the flange pin 2860 is configured to insert into the second opening 2832 of the interface hub 2802, even though the second opening 2832 has an oblong shape. The larger second opening 2832 may help with the initial alignment of the top 2850 to the interface hub 2802 by only requiring partial alignment, which in turn may help the user complete the remaining alignment and attachment of the top 2850 with the ramp pin 2860 and first opening 2830. In addition, the raised arcuate flange 2862. which projects inferiorly beyond portions of the adjacent ramp surfaces 2854. may also provide a further alignment structure that aligned to the outer arcuate edges of the ramp surfaces 2804 near the flange 2834 of the interface hub 2802.

[0174] In addition to the different rotatable / mounting interface of the biometric capture system 2800 compared, for example, to the system 2400 depicted in FIGS. 24A to 26E, the non-rotating top 2850 of system 2800 also includes a hood 2890 to block extraneous environmental light. The hood 2890 of the top 2850 is located above the imaging window 2872 that supports the inserted finger at the desired imaging plane. In this particular embodiment of the imaging top 2850, the imaging window 2872 is located in an elongate channel 2874 of the top 2850. The hood 2890 comprises an upper shield or body 2892 with side legs or walls 2894 with flanges 2896 or channels that interface with complementary flanges 2876 and / or channels 2878 of the channel side walls 2868. The linear 37

[0175] 4921-1033-1530'1P324457.US.01 configurations of the flanges 2876 and channels 2878 allow the hood 2890 to slide along or out of the so that larger appendages can be accommodated, or to allow easier access to the imaging window 2872 when extraneous environmental light does not pose any issues, e.g. during indoor use. In a further variation, depicted in FIG. 30A, the imaging top 2850 may also comprise a separate set of flanges 2866 and / or channels from the flanges 2876 or channels 2878 that are engaged to provide light shielding. This second set of flanges 2866 and / or channels allow the storage of the hood 2890 away from the channel 2874 and imaging window 2872, to reduce the risk of losing the hood 2890. FIGS. 30B and 30C depict the hood 2890 of the imaging top 2850 in the storage position coupled to the secondary flanges 2866, and the in the cover position coupled to the flanges 2876 and channels 2878 when used for blocking light. In other variations, a contiguous set of flanges or channels may be provided with complementary pins (rather than linear flanges) on the hood to allow the hood to slide around bends in the flanges or channels, or may be provided with a rotatable joint, to allow the slide or flip out of the way from the channel or imaging window, without actually detaching from the top.

[0176] FIGS. 31Ato 31 J depicts an embodiment of a non-rotating prism top 3100 that is configured with the ramp / stop interface, similar to the rotating top 2808 and non-rotating top 2850 of system 2800, and thus is compatible for use with the systems 2800 depicted in FIGS. 28A to 281 and 29A to 29H. The top 3100 shares some of the design principles, structures and features of the exemplary prism top 2452 described herein and depicted in FIGS. 24A to 26E, except for different mounting interface for compatibility with the system 2800 depicted in FIGS. 28 A to 281 and 29A to 29H. and the addition of an optional protective bottom window 3110, to protect the prism top 3100 from dirt or foreign object intrusion.

[0177] The prism top 3100 comprises a triangular block prism 3102 that is received in a prism cavity 3106 of a prism support 3138 of an inner housing 3104. An angled lower light blocking flange 3108 is also provided the block extraneous light from the light source of the system that may cause image artifacts and / or contract loss. The flange 3108 also includes a groove, ridge or recess to support and attach the optional lower protective window 3110, maintaining the window 3110 at an angle that is orthogonal to the imaging path of the system to minimize or reduce reflections. This window 3110 is separate from the protective window provided in the system housing or the interface hub, to protect the imaging assembly, e.g. window 2468 of hub 2404 in FIG. 25 A. or w indow 2820 of interface hub 2802 in FIGS. 28L and 291.

[0178] The lower housing 3104 also includes lumens 3112 for receiving the mounting pins 3114 which are used to align the top 3100 to the first and second openings 2830, 2832 of the interface hub 2802, depicted in FIGS. 28A to 281. The mounting pins 3114 may or may not be partially threaded to help maintain the pins 3114 in the lumens 3112, but can otherwise be maintained in 38

[0179] 4921-1033-1530'1P324457.US.01 place, along with the prism 3102, once the outer housing 3120 is attached to the lower housing 3104, thereby sandwiching the prism 3102 and the mounting pins 3114 in place.

[0180] The outer housing 3120 includes an imaging window 3130 that may be sized to also act as a retention frame to retain the prism 3102 in the top 3100. The outer housing 3120 includes a prism housing 3132 and housing cavity 3134 that is sized to receive the prism housing 3136 of the lower housing 3104. Although this particular exemplary prism top 3100 provides the ratchet interface and raised flange as part of its lower housing 3104, in other variations, these structures may be provided by the outer housing or partially by the outer housing.

[0181] The outer housing 3120 may be attached to the lower housing 3104 using adhesives, heat welding and / or fasteners, such as the attachment screw" 3116 and threaded insert 3118 As with other tops usable with the ratcheting interface of system 2800, the lower housing 3104 of the prism top 3100 also comprises alternating ramp surfaces 3122 and stop surfaces 3124, and a raised posterior flange 3126 though which one of the mounting pins 3114 projects. The outer housing 3120 also includes a smaller posterior flange 3136, which can be configured to function as a retention cap to the mounting pin 3114. Although the prism top 3100 is not configured for rotation, the top 3100 may still include finger recesses 3128 for consistency with the rotating tops and / or to facilitate handling.

[0182] Although the exemplary embodiments described herein have included arrangements of magnet elements located in the interface hub and various tops described herein, each of the embodiments described herein may include variants wherein only the hub comprise magnet elements, while the tops comprise ferrous material elements (or vice versa) which are attractable by the magnet elements in the hub. In still other variants, neither the hub nor the tops have magnetic elements, and are used simply by placement of the top onto the hub. See FIG. 33A comprising a fingerprinting system 3300 with an interface hub 3302 and a top 3304 that are configured to be rotated but wherein the top relies on gravity and / or undulations in the interface hub 3302 to maintain its position on the interface hub 3302. In these non-magnetic embodiments, the tops may have the rotational configuration the same or similar to the magnetic embodiments, such as the undulating or alternating ramp / stop surfaces of the embodiments described herein. FIG. 33B depicts an alternative embodiment of a fingerprinting system 3310 lacking ferromagnetic elements to attach the top 3314 to the interface hub 3312, but wherein the interface hub 3312 includes a central rotation post 3316 which inserts into a corresponding complementary opening 3318 of the top 3312, which allows the top 3312 to rotate while engaged. In still another embodiment, the system may comprise a series of spaced apart arcuate J-shaped flanges on the top or hub, which in turn engage a series of spaced apart single flanges that can rotatably engage the J-shaped flanges on the hub or top, but can allow removal of the top when the complementary 39

[0183] 4921-1033-1530'1P324457.US.01 flanges are fully out of overlapping alignment. In other non-magnetic embodiment, instead of a rotational interface, the tops and hub may comprise a mechanical interfit configuration, e.g., complementary alignment posts and recesses to releasably attach the tops to the hub. In this variation, the tops are not rotatable, and may require removal of the top from the hub, then changing the orientation of the top and reattaching the top to the hub. In FIG. 33C, for example, the fingerprinting system 3320 comprises an interface hub 3322 with protruding posts 3326 which are configured to be inserted into corresponding alignment apertures 3328 located in the top 3324. In this embodiment, the system 3320 lacks a central post, but in other embodiments, such as the system 3340 depicted in FIG. 33D, the system 3330 includes peripheral posts 3336 and a central post 3340 on the interface hub 3332, and corresponding peripheral openings 3338 and a central opening 3342 on the top 3334. A person of skill in the art will also understand that in still other variations, the arrangement of posts and openings, or the flanges, may be reversed between the tops and the hubs.

[0184] Some variations described herein relate to a computer storage product with a non-transitory computer-readable medium (also may be referred to as a non-transitory processor-readable medium) having instructions or computer code thereon for performing various computer-implemented operations. The computer-readable medium (or processor-readable medium) is non-transitory in the sense that it does not include transitory propagating signals per se (e.g., a propagating electromagnetic wave carry ing information on a transmission medium such as space or a cable). The media and computer code (also may be referred to as code or algorithm) may be those designed and constructed for the specific purpose or purposes. Examples of non-transitory computer-readable media include, but are not limited to, magnetic storage media such as hard disks, floppy disks, and magnetic tape; optical storage media such as Compact Disc / Digital Video Discs (CD / DVDs); Compact Disc-Read Only Memories (CD-ROMs), and holographic devices; magneto-optical storage media such as optical disks; solid state storage devices such as a solid state drive (SSD) and a solid state hybrid drive (SSHD); carrier wave signal processing modules; and hardware devices that are specially configured to store and execute program code, such as Application-Specific Integrated Circuits (ASICs), Programmable Logic Devices (PLDs), Read-Only Memory' (ROM), and Random- Access Memory (RAM) devices. Other variations described herein relate to a computer program product, which may include, for example, the instructions and / or computer code disclosed herein.

[0185] The systems, devices, and / or methods described herein may be performed by software (executed on hardware), hardware, or a combination thereof. Hardware modules may include, for example, a general-purpose processor (or microprocessor or microcontroller), a field programmable gate array (FPGA), and / or an application specific integrated circuit (ASIC).

[0186] 40

[0187] 4921-1033-1530'1P324457.US.01 Software modules (executed on hardware) may be expressed in a variety of software languages (e.g., computer code), including C, C++, JAVA®, Python, Ruby, VISUAL BASIC®, and / or other object-oriented, procedural, or other programming language and development tools. Examples of computer code include, but are not limited to, micro-code or micro-instructions, machine instructions, such as produced by a compiler, code used to produce a web service, and fdes containing higher-level instructions that are executed by a computer using an interpreter. Additional examples of computer code include, but are not limited to, control signals, encrypted code, and compressed code.

[0188] In some variations, the systems and methods may be in communication with other computing devices (not show n) via, for example, one or more networks, each of which may be any type of network (e.g., wired network, wireless network). A wireless network may refer to any type of digital network that is not connected by cables of any kind. Examples of wireless communication in a wireless network include, but are not limited to cellular, radio, satellite, and microwave communication. How ever, a wireless network may connect to a wired network in order to interface with the Internet, other carrier voice and data networks, business networks, and personal networks. A wired network is typically carried over copper twisted pair, coaxial cable and / or fiber optic cables. There are many different types of wired networks including wide area networks (WAN), metropolitan area networks (MAN), local area networks (LAN), Internet area networks (IAN), campus area networks (CAN), wireless personal area network (PAN) (e.g., Bluetooth, Bluetooth Low Energy), global area networks (GAN), like the Internet, and virtual private networks (VPN). Hereinafter, network refers to any combination of wireless, wired, public and private data networks that are typically interconnected through the Internet, to provide a unified networking and information access system.

[0189] Cellular communication may encompass technologies such as GSM, PCS, CDMA or GPRS, W-CDMA, EDGE or CDMA2000, LTE, WiMAX, and 5G networking standards. Some wireless network deployments combine networks from multiple cellular networks or use a mix of cellular, Wi-Fi, and satellite communication. In some variations, the systems, devices, and methods described herein may include a radiofrequency receiver, transmitter, and / or optical (e.g., infrared) receiver and transmitter to communicate with one or more devices and / or networks.

[0190] While various embodiments above have been particularly shown and described with references to embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the embodiments. For all of the embodiments described above, the steps of the methods need not be performed sequentially.

[0191] 41

[0192] 4921-1033-1530'1

Claims

P324457.US.01WHAT IS CLAIMED IS:

1. A fingerprint input system, comprising:a housing, comprising:an interface hub, the hub comprising:an imaging opening;an annular surface surrounding the imaging opening;an imaging assembly inside the housing and comprising an imaging axis;a lighting assembly inside the housing;a multi -aperture top configured to releasably attach to and to form a rotational interface with the interface hub, the multi -aperture top comprising:a lower annular surface configured to form a complementary rotational interface with the annular surface of the interface hub;a plurality of finger receiving apertures, wherein each aperture is a different size; anda prism top configured to releasably attach to and to form a non-rotational mechanical interfit interface with the interface hub; the prism top comprising:a prism;a prism housing with an outer prism opening and wherein the prism housing is configured to retain the prism at the outer prism opening;an annular surface configured to form a complementary interface with the annular surface of the interface hub.

2. The system of claim 1, wherein the prism is triangular prism.

3. The system of claim 1, wherein the prism is an irregular or scalene prism.

4. The system of claim 1, wherein the prism is a porro prism.

5. The system of claim 1, wherein the outer prism opening of the prism housing is configured to intersect the imaging axis of the imaging assembly when the prism housing is attached to the interface hub.

6. The system of claim 5, wherein the prism housing further comprises an inner prism opening, and wherein the inner prism opening is configured to intersect the imaging axis of the imaging assembly when the prism housing is attached to the interface hub.

7. The system of claim 6, wherein the prism housing further comprises a light baffle structure at least partially surrounding the inner prism opening and configured to block light from the lighting assembly when the prism housing is attached to the interface hub.424921-1033-1530'1P324457.US.01 8. The system claim 6, wherein the prism housing comprises an upper prism top shell comprising the upper prism opening and further comprising an upper prism frame to retain the prism, and a lower prism top shell comprising the lower prism opening and the light baffle, and comprising a lower prism frame to retain the prism.

9. The system of claim 8, wherein the lower annular surface of the prism top is integrally formed with the low er prism housing.

10. The system of claim 1, wherein the prism comprises an outer prism surface configured to be positioned at the outer prism opening, a base prism surface configured to be positioned at the inner prism opening.

11. The system of claim 10, wherein the prism further comprises an intermediate prism surface coated with a light absorbing material.

12. The system of claim 10, wherein a surface area of the outer prism opening is greater than a surface area of the outer prism surface.

13. The system of claim 10, wherein the outer prism surface is configured to be oriented at an angle of incidence of 42 degrees or less when the prism housing is attached to the interface hub.

14. The system claim 10, wherein the angle of incidence of the outer prism surface is in the range of 10 degrees to 30 degrees with respect to the imaging axis.

15. The system of claim 14, wherein the angle of incidence of the outer prism surface is in the range of 15 degrees to 25 degrees with respect to the imaging axis.

16. The system of claim 14, wherein the angle of incidence of the outer prism surface is in the range of 20 degrees to 25 degrees with respect to the imaging axis.

17. The system of claim 10, wherein the base prism surface is, relative to the imaging axis of the imaging assembly, angled in the range of 20 to 60 degrees.

18. The system of claim 17, wherein the base prism surface is, relative to the imaging axis of the imaging assembly, angled in the range of 30 to 50 degrees.

19. The system of claim 17, wherein the base prism surface is, relative to the imaging axis of the imaging assembly, angled in the range of 35 to 45 degrees.

20. The system of claim 7, wherein the light baffle comprises an inferior vertical wall.

21. The system of claim 20, wherein the light baffle further comprises at least one horizontal wall projecting transversely from the vertical wall.

22. The system of claim 20, wherein the inferior vertical w all is angled tow ard the imaging axis by 0 to 10 degrees.

23. The system of claim 1, further comprising:434921-1033-1530'1P324457.US.01 a plurality of ferromagnetic hub elements located along the annular surface of the interface hub; anda plurality' of ferromagnetic top elements located along the annular surface of the multiaperture top;wherein at least one of the plurality’ of ferromagnetic hub elements and the plurality of ferromagnetic top elements comprises magnets.

24. The system of claim 23, wherein the plurality of ferromagnetic hub elements comprises a plurality of hub magnet elements.

25. The system of claim 23, further comprising a plurality of ferromagnetic prism top elements located along the annular surface of the prism top.

26. The system of claim 1, wherein the prism top comprises a lower protective window below the prism.

27. The system of claim 1, wherein the annular surface of the interface hub comprises an arrangement of alternating ramp and stop surfaces, and wherein the annular surface of the multi-aperture top comprises an arrangement of alternating ramp and stop surfaces complementary to the arrangement of alternating ramp and stop surfaces of the interface hub.

28. The system of claim 27, further comprising:a plurality' of ferromagnetic hub elements located along the annular surface of the interface hub; anda plurality of ferromagnetic top elements located along the annular surface of the multiaperture top.

29. The system of claim 28, wherein the plurality of ferromagnetic hub elements and the plurality of ferromagnetic top elements are located at their corresponding stop surfaces.

30. The system of claim 29, wherein the plurality of ferromagnetic hub elements and the plurality of ferromagnetic top elements have an angled or offset arrangement configured to rotationally or horizontally bias the complementary stop surfaces of the uni-directional interface toward each other.

31. A fingerprint input system, comprising:a main housing, comprising:an elongate handle comprising a longitudinal axis; andan interface hub coupled to the elongate handle, the hub comprising:an inner annular surface surrounding an imaging opening;444921-1033-1530'1P324457.US.01 an outer annular surface surrounding the inner annular surface;a plurality of peripheral hub magnets equally spaced around the outer annular surface and each of the plurality of hub magnets located a same hub radial distance from a center of the interface hub;an actuator located on the elongate handle;an imaging assembly inside the elongate handle and comprising an imaging axis;a lighting assembly inside the elongate handle;a multi -aperture top configured releasably attach to and to form a rotational interface with the interface hub, the multi -aperture top comprising:a lower annular surface configured to form a complementary rotational interface with the outer annular surface of the interface hub;a plurality of finger receiving apertures, wherein each aperture is a different size; anda plurality of aperture top magnets equally spaced around the lower annular surface of the multi-aperture top and each of the plurality of aperture magnets located a same top radial distance from a center of the multi-aperture top and comprising a complementary alignment to the plurality of hub magnets in the interface hub; anda prism top configured to releasably attach to and to form a non-rotational interface with the interface hub; the prism top comprising:a prism;a prism housing with an outer prism opening and wherein the prism housing is configured to retain the prism against the outer prism opening;a lower annular surface configured to form a complementary' interface with the outer annular surface of the interface hub;a plurality of prism top magnets spaced around the lower annular surface of the prism top and each of the plurality of prism magnets located a same top radial distance from a center of the prism top and comprising a complementary' alignment to the plurality' of hub magnets in the interface hub.

32. The system of claim 31, wherein the interface hub further comprises a retention ledge offset from the inner annular surface and from the outer annular surface, wherein the retention ledge is configured to resist dislodgement of the multi-aperture top or the prism top when attached to the interface hub.

33. The system of claim 31, wherein the prism is triangular prism.

34. The system of claim 31, wherein the prism is an irregular or scalene prism.454921-1033-1530'1P324457.US.01 35. The system of claim 31, wherein the prism is a porro prism.

36. The system of claim 30, wherein the outer prism opening of the prism housing is configured to intersect the imaging axis of the imaging assembly when the prism housing is attached to the interface hub.

37. The system of claim 36, wherein the prism housing further comprises an inner prism opening, and wherein the inner prism opening is configured to intersect the imaging axis of the imaging assembly when the prism housing is attached to the interface hub.

38. The system of claim 37, wherein the prism housing further comprises a light baffle structure at least partially surrounding the inner prism opening and configured to block light from the lighting assembly when the prism housing is attached to the interface hub.

39. The system claim 37, wherein the prism housing comprises an upper prism top shell comprising the upper prism opening and further comprising an upper prism frame to retain the prism, and a lower prism top shell comprising the lower prism opening and the light baffle, and comprising a lower prism frame to retain the prism.

40. The system of claim 39, wherein the lower annular surface of the prism top is integrally formed with the lower prism housing.

41. The system of claim 31, wherein the prism comprises an outer prism surface configured to be positioned at the outer prism opening, a base prism surface configured to be positioned at the inner prism opening.

42. The system of claim 41, wherein the prism further comprises an intermediate prism surface coated with a light absorbing material.

43. The system of claim 41, wherein a surface area of the outer prism opening is greater than a surface area of the outer prism surface.

44. The system of claim 41, wherein the outer prism surface is configured to be oriented at an angle of incidence of 42 degrees or less when the prism housing is attached to the interface hub.

45. The system claim 41, wherein the angle of incidence of the outer prism surface is in the range of 10 degrees to 30 degrees with respect to the imaging axis.

46. The system of claim 45, wherein the angle of incidence of the outer prism surface is in the range of 15 degrees to 25 degrees with respect to the imaging axis.

47. The system of claim 45, wherein the angle of incidence of the outer prism surface is in the range of 20 degrees to 25 degrees w ith respect to the imaging axis.

48. The system of any one of claims 11 to 17, wherein the base prism surface is, relative to the imaging axis of the imaging assembly, angled in the range of 20 to 60 degrees.464921-1033-1530'1P324457.US.01 49. The system of claim 48, wherein the base prism surface is, relative to the imaging axis of the imaging assembly, angled in the range of 30 to 50 degrees.

50. The system of claim 48, wherein the base prism surface is, relative to the imaging axis of the imaging assembly, angled in the range of 35 to 45 degrees51. The system of claim 48, wherein the light baffle comprises an inferior vertical wall.

52. The system of claim 51, where in the light baffle further comprises at least one horizontal wall projecting transversely from the vertical wall.

53. The system of claim 51, wherein the inferior vertical wall is angled toward the imaging axis by 0 to 10 degrees.

54. The system of claim 31, wherein the prism top further comprises elongate projections and the interface hub comprises elongate cavities configured to receive the elongate projections of the prism top.

55. The system of claim 54, where the elongate projections are located on the lower annular surface of the prism top and the elongate cavities are located on the outer annular surface of the interface hub.

56. The system of claim 31, wherein the prism top further comprises a hood structure overlying the outer prism opening, and forming a finger insertion opening lateral to the outer prism opening.

57. The system of claim 56, wherein the hood structure comprises a fixed structure and a movable structure.

58. The system of claim 57, wherein the fixed structure and movable structure comprises a translatable tongue-in-groove interface.

59. The system of claim 58, wherein the tongue-in-groove interface comprises retention blocks to resist complete separation of the movable structure from the fixed structure.

60. The system of claim 58, wherein the fixed structure is configured with a second groove or a flange to releasably receive the movable structure in a different location and / or orientation from the tongue-in-groove interface.

61. The system of claim 57, wherein fixed structure and movable structure comprises a rotatable joint configured to allow the movable structure to flip away from the outer prism opening.

62. The system of claim 57, wherein the fixed structure and movable structure comprises a releasable latch interface that is configured to allow complete removal of the movable structure from the fixed structure.

63. The system of claim 31, wherein the rotational interface between the multi-aperture top and the interface hub is a uni-directional rotational interface.474921-1033-1530'1P324457.US.01 64. The system of claim 63, wherein the uni-directional interface comprises a ratchet configuration comprising an arrangement of alternating ramp and stop surfaces located on each of the multi -aperture top and the interface hub.

65. The system of claim 64, wherein the plurality of aperture top magnets of the multiaperture top and the plurality of hub magnets in the interface hub are located at the corresponding stop surfaces.

66. The system of claim 65, wherein the plurality of aperture top magnets and the plurality of hub magnets have an angled or offset arrangement configured to rotationally or horizontally bias the complementary stop surfaces of the uni-directional interface toward each other.

67. The system of claim 65, wherein the prism top comprises a lower protective window below the prism.

68. A fingerprint input system, comprising:a main housing, comprising:an elongate handle comprising a longitudinal axis; andan interface hub coupled to the elongate handle, the hub comprising:an inner annular surface surrounding an imaging opening;an outer annular surface surrounding the inner annular surface;a plurality of peripheral hub magnets equally spaced around the outer annular surface and each of the plurality of hub magnets located a same hub radial distance from a center of the interface hub;an actuator located on the elongate handle;an imaging assembly inside the elongate handle and comprising an imaging axis;a lighting assembly inside the elongate handle;a multi -aperture top configured releasably attach to and to form a ratchet interface with the interface hub, the multi -aperture top comprising:an arrangement of alternating ramp and stop surfaces located on each of the multi-aperture top and the interface hub;a plurality of finger receiving apertures, wherein each aperture is a different size; anda plurality of aperture top magnets equally spaced around the low er annular surface of the multi-aperture top and each of the plurality of aperture magnets located a same top radial distance from a center of the multi-aperture top and comprising a complementary alignment to the plurality of hub magnets in the interface hub.484921-1033-1530'1P324457.US.01 69. The system of claim 68, wherein the plurality of aperture top magnets of the multiaperture top and the plurality of hub magnets in the interface hub are located at the corresponding stop surfaces.

70. The system of claim 69, wherein the plurality of aperture top magnets and the plurality of hub magnets have an angled or offset arrangement configured to rotationally or horizontally bias the complementary stop surfaces of the uni-directional interface toward each other.494921-1033-1530'1

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