HK1105468A - Finger guide device for use with stylus or pen - Google Patents

Description

Finger guide device for a stylus or pen

Technical Field

The present invention relates generally to a finger guide, referred to as a finger guide device, for positioning a finger, thumb or digit containing a unique detail on a scanner or sensor or other device to capture an image of the minute features of the major and relevant portions of the detail, also equivalently referred to as a fingerprint. Such finger guide devices may be used with electronic, optical, electroluminescent, electromagnetic, capacitive, pressure-based or similar scanners or sensors that require repeated and suitably precise positioning of the finger in alignment with the scanner or sensor, which is placed in a stylus or pen. Applications include the accurate identification or recognition of an individual or a particular finger of an individual to minimize the number of false rejects or iterations of the process for scanning, sensing or capturing the relevant and previously enrolled portions of the fingerprint.

Background

U.S. patent application No.2004101172(Lane) discloses a finger imaging system for a recipient's finger that acquires its fingerprint using an automated fingerprint reader. The system includes a finger imaging device having a finger receiving portion for receiving a finger of an acquired fingerprint. The locator bar extends outwardly from the finger receiving surface and engages a skin fold of the subject finger when the finger is approximately in the desired position. Us patent application 2004101171(Lane et al) discloses a finger imaging system for receiving and holding a human finger, the fingerprint of which is acquired with an automatic fingerprint reader. The system includes a finger imaging device having a finger receiving portion and a finger positioning portion that together form a reduced size recess so that a subject finger forcibly inserted therein is held in a stable position. And finally, U.S. patent application No.2004076314(Cheng) discloses an apparatus that includes a fingerprint sensor and a guide device. The sensing portion of the fingerprint sensor forms an opposite and obtuse angle with the guide plane of the guide means.

Traditionally, to record a fingerprint, ink is applied to a finger and then the finger is "rolled" across a paper or other ink receiving surface to print a fingerprint image. Fingerprints left by contacting the surface and leaving residual oil are captured by various techniques, which "lift" and reveal the fingerprint.

In recent years, alternative techniques have been proposed that can reveal fine features in a fingerprint and capture the fingerprint directly from the finger or from living tissue beneath the surface of the finger's skin that grows outward to form finger minutiae. Electronic sensing techniques include holding a finger on a sensing system while the system detects skin or tissue differences through the finger area or only a portion of the finger area to reveal an image of the fingerprint or to form an electronic representation of the fingerprint, for example as a digital file. Examples include optical scanners, electroluminescent pressure sensing systems, integrated circuits capable of measuring capacitance of individual pixel sizes, and the like.

The cost of production of some types of fingerprint scanning systems is driven by the size of the finger area being sensed. This is particularly true for silicon-based or Integrated Circuit (IC) type sensors. Like most ICs, the larger the IC, the higher its production cost if the device geometry and number of layers are equal. The production cost of the sensor is directly related to the sensing area, and mass production of the sensor, the thumb size is not optimal when only the relevant portion of the finger needs to be scanned to create a fingerprint authentication system. If only the relevant portion of the fingerprint is used to reduce system cost, it is important that for each authentication or identification event, nearly the same portion of the finger as was originally enrolled is placed on the sensor.

Obviously smaller sensors are less costly and the best solution would be such smaller sensors, not considering most of the entire fingerprint area, provided that the relevant area of the finger being sensed still has to be large enough to provide an acceptable matching capability or security level. The finger guide device of the present invention is one that can be used to reliably reposition the finger on a small sensor for more efficient identification. The device reduces false rejects caused by not positioning the finger sufficiently close to the location or locations at which it was initially registered. The finger guide device ensures that the sensor is able to read the relevant portions of the fingerprint match, which is used to ensure that the relevant portions are read substantially identical to those captured and stored in the template for comparison and matching. The finger guide device reduces the occurrence of false rejects by naturally (e.g., comfortably or intuitively) and non-forcibly guiding the subject finger to substantially (substantially) the same and initial enrollment position each time the fingerprint recognition system is used.

When using smaller sensors, if a finger is enrolled in such a way that a relevant portion of the finger, or possibly multiple overlapping portions of the finger's printed area, is scanned and then electronically assembled by a computer into a complete "template" representing a larger portion of the original subject's fingerprint than any individual scan could produce alone, the system relies on the subject user being able to consistently touch the sensor in the same approximate location so that the matching relevant portion of the finger is read by the sensor to enable accurate authentication. Failure to precisely reposition the finger in substantially the same location results in false rejects; or in other words, because the sensor sees different and non-relevant areas of the finger, it cannot match data from previously enrolled relevant fingerprint portions in the template, and it rejects known acceptable subject users. This is a false rejection. The subject is accepted (identified or "authenticated") if the system makes additional attempts, and if a second or subsequent attempt finally aligns minutiae containing relevant portions of the fingerprint that match the portions originally stored during enrollment. By providing a simple, substantially oval or rectangular funnel-like guide for the finger that actually urges the finger into the correct position, and providing the subject user with various tactile feedback means to make it easier to "find" the correct position again, the finger guide device reduces the average number of attempts to authenticate a known subject even though a long time has passed between enrollment and the next authentication event. In contrast, with basic flat surface sensors or sensors surrounded by a substantially flat surface or even poorly designed sensors, this false rejection rate ranges from ten to fifteen percent of all attempts for untrained subjects, or even higher for different system settings.

Disclosure of Invention

Much like a substantially circular, oval, square or rectangular funnel directs fluid into a container; a finger guide device or finger "dimple" (recess) is used to guide the finger in a repeatable manner towards the same location on the sensor. Another simple analogy is to describe a ball located on the apex of a cone, which is unstable compared to a ball located at the global minimum of an inverted cone or recess, where the ball always rolls to the same global minimum position by gravity and the recess sidewalls. In the case of the finger guide device, the less pronounced action is initiated by muscles, applying the appropriate force to easily slide the finger towards the sensor area, which natural movement is also achieved by tactile feedback from the ergonomically designed side wall of the device, guided by the described and disclosed physical, material and tactile elements in the finger guide device to guide the finger to the same position each time, through communication with the subject user and natural movement towards said position. The sensor will sit in a window at the bottom of the finger guide device in the correct position adjacent to the ideal finger area to "see" a preferred portion (bump) of the fingerprint.

Previous devices for positioning a finger for fingerprint imaging focused on the requirement to hold (nearly squeeze) the finger onto a flat scanning surface and tended to roughly position the finger from the leading edge of the nail or skin wrinkles located under the first joint in the finger. This intent appears to replace the effect of rolling a fingerprint and the pressure used to flatten the finger appears to be an important element. Modern semiconductors or sensors require only light contact and, as observed, often focus on repeatedly scanning or capturing substantially the same relevant portion of the fingerprint over and over as long as the finger remains substantially actively aligned with the sensor. The present invention provides an effective aid and a learning mechanism that helps the subject position the finger in the correct position on a repeatable basis with the relevant part of the finger aligned with the scanner or sensor and also makes the correct contact (pressure) through a set of approaches including physical shape, feedback means and material properties. Furthermore, the device is designed to optionally reposition the fingerprint region, which is located a distance of approximately between 0.20 and 0.90 inches from the underside of the fingernail, and thus, from the tip of the finger below the fingernail rather than the ridge below the first joint in the finger. In addition, the finger guide device ridge at the front has a low enough profile to avoid contacting the fingernail. This contact will introduce errors because different subjects will sometimes trim their nails to different lengths at different times, and most will also find the pressure on the nail tips uncomfortable, both of which were present in previous devices to position the finger on a fingerprint reader or scanner.

The physical design of the finger guide device enables the placement of relevant portions of the finger on the center of the sensor with sufficient accuracy to significantly increase the percentage of first time acceptance (of enrolled subjects). This includes a relatively short concave radius (or relatively steep slope) at the front of the finger guide device where the tip of the finger just below the fingernail touches or is near the front of the finger guide device; and a longer radius concave shape (or less steep slope) adjacent the opposite side of the sensor where the cup extends along the finger toward the person. The sides on either side of the scanner or sensor area are very steep to keep the relevant part of the finger centered laterally on the scanner or sensor. In general, the finger guide device is sized for a typical finger, yet accommodates a wide range of finger sizes, as it only contacts a small relevant portion of the finger or finger.

The tolerance allowed for placing a finger on a small electronic sensor mounted on a flat surface is quite forgiving, however locating the relevant part of the finger on these devices that do not have the benefit of the finger guide device is difficult for untrained subjects. This may be limited to approximately half to two-thirds of the fingerprint area to be scanned overlapping the prior scan and other relevant portions of the fingerprint present in the template, depending on the algorithm used and the accuracy of the system. The low accuracy system may operate such that less than half of the sensor window is set to overlap between the authentication scan and its corresponding relevant portion in the stored template. The actual relevant part for the security matching requirement depends on the algorithm and, in the algorithm, the security level or security setting actually required. This relates to the relevant portion of the fingerprint of the scanned subject that is associated with the enrolled template for that subject.

The ability to place the same relevant portion of the fingerprint on the active area (window) of the sensor on a consistent and repeatable basis facilitates a fast and accurate first attempt match and this significantly reduces the false reject rate. In enrolled but unskilled subjects, the finger guide device invention reduces false rejects to ten percent. Practice using the finger guide device or system optimization or a combination of both will further reduce the false rejection rate; and in the ideal case of using an optimized system, a finger guide in a stylus or pen can reduce the false rejection rate to less than two percent.

The reduction in false rejection rates from within 10% and 20% of the trials and with an average of about 15% to below 2% is of great significance in pen or stylus based security system acceptance and market acceptance. Frustration in the subject user population is significantly reduced if one does not need to touch the sensor multiple times and is therefore accepted. This is particularly important in pen or stylus applications where specific user dexterity is often required to lift and replace the finger for each additional authentication attempt. As an aid to reducing the need for special dexterity and facilitating the practical operation of such required devices, some fingerprint equipped pens include special pliable grip or non-slip grip surfaces.

In the end of 2003, a new keyboard was introduced to approximately 250,000 users and had no finger guide solution. There is considerable frustration in the user base and the companies that deploy the system face severe criticism. This problem causes the user to question the performance of the system even if it is technically considered as a mistake or user error in the user's inaccurate finger placement (misalignment of the sensor) during the authentication process. The finger guide device reduces such anticipated user error and increases the likelihood that the subject is accepted in the first contact. This saves a lot of time over the life of the system and is a key element for developing biometric systems, which can be consistently compared to passwords or PINs in terms of user time and efficiency.

In practice and application, the use of the finger guide device for enrollment and authentication improves the efficacy of the finger guide device. This is because the natural feel of the finger guide device ergonomically guides the user to approximately the same position or aligns the relevant portion of the finger over the active sensing area each time. This guidance process is physical and neutral, providing tactile feedback for first use and subsequent learning.

During enrollment, the system may require the subject to move the finger and contact the finger with the scanner or sensor multiple times (e.g., to "lift and replace" the finger). The finger guide device is basically designed to accommodate the fingers or thumb of the left or right limb. This means that it facilitates such multiple placement but does not strictly limit such placement to accurate and precisely repeatable accurate placement, it only allows such placement to be within the tolerance of the sensor and algorithm so that the relevant portion of the subject's finger is aligned with the scanner or sensor. This allows the template to exceed the strict limits of the ideal or "right" window frame (protrusion) and thus form a guard band designed to accommodate, within tolerances, the appropriate level of misalignment in the future and the guiding capabilities of the finger guide device. This functionality is important for long-term, repeatable performance, and the alignment capability facilitated by the finger guide device need only be raised to the limits required by the matching system, including but not limited to template size and safety level of the algorithm.

Some sensors drive electrical potentials or electromagnetic signals into the finger tissue. This may be a radio frequency signal. The finger guide device or a surface thereof may be electrically conductive to facilitate such application during enrollment and subsequent authentication events. The finger guide device may be designed with a preferred embodiment of a substantially parabolic shape to focus the reflected electromagnetic energy onto the relevant part of the finger and improve the characteristics of the sensed information in a process called illumination.

The surface characteristics and materials selected for the finger guide device are important to performance. Because the finger should slide easily into place, a low coefficient of friction (sliding coefficient and static coefficient) is useful to allow the finger to rest at its natural global minimum position at the bottom of a finger guide device properly positioned on the scanner or sensor. The surface properties and resulting process constantly position the finger in the same proximal location. Examples of materials with suitably low coefficients of friction include, but are not limited to, smooth metals, smooth plastics, and even painted, polished, or waxed surfaces. The utility and function of the finger guide device may be reduced or impaired if the surface material has a high coefficient of friction, such as rubber, polyurethane-based materials, or rough plastics. Wet or dry lubricants and waxes may also be applied and suitable lubricants may even be mixed into the cleaning solution or special cleaning wipes.

Other feedback means may be included in preferred or even alternative embodiments of the invention. When they gain the experience of using the finger guide device, one will create the ability to feel the correct position. The finger guide device may be made of a material with high thermal conductivity to provide tactile feedback and speed up the learning process. Examples include, but are not limited to, metals, certain ceramics, or certain carbon-based materials. In this case, the finger guide device will feel cooler to touch at room temperature (relative to the rest of the pen or stylus), not due to its absolute temperature, but because it has a thermal conductivity that conducts heat quickly away from the skin when touched, thus quickly cooling the sensitive surface of the finger when touched. If the finger guide device is made of metal, this characteristic will make it feel like a metal touch (e.g., a cold feel). By feeling colder than the rest of the pen compared to the silicon sensor and its surface coating, the subject will perceive the correct "feel" of the finger guide device and will also feel the sensor better.

Additional projections may be added to help orient the fingers or to cause the subject to "fine tune" their finger position. These may not be necessary for normal or average sized fingers, but are valuable in applications where the body has very small fingers that contact very little of the finger guide device surface area.

Braille may be added to the finger guide device to facilitate blind or visually impaired users.

The finger guide device may also use physical elements and material properties to prevent inaccurate use. For example, one preferred method of practicing the present invention surrounds the finger guide device with a relatively hard and distinct ridge. Rather than being a "sharp" object that is perceived as dangerous, such ridges are intended to provide discomfort to the subject user. When a finger is placed on this ridge, although harmless, it is uncomfortable because it applies high pressure Per Square Inch (PSI) to the skin over the narrow ridge line. This high pressure per square inch indicates in the touch sensor that the pen is not properly grasped. The feel of the misaligned grip is an unnatural feel and the user will instinctively reposition his or her grip to achieve a more natural and comfortable feel. The natural tendency is to avoid holding the pen on the outer ridge of the finger guide but to slide the finger or thumb down into the finger guide and onto the sensor (ideally positioned). It is in this correct position that the feeling of holding the stylus is natural and safe (stable) for the subject user. Sometimes used interchangeably and as the wording of an equivalent stylus or pen, herein intended to include any elongate tool which is held or gripped by a user and which is capable of writing on a surface.

Additional embodiments of the present invention may include active feedback mechanisms, including feedback designed to alert (and train) subjects as to the correct positioning of their fingers or to alert subjects to the fact that they have been accepted in the system (i.e., their fingerprints have been scanned, compared and correctly matched). The sound may be used to "guide" the finger to the sensor. Visual indicators may also be used. Finally, physical motion such as vibration can be used in a manner very similar to a stick shaker that alerts the pilot of a stall warning when flying an airplane. In another preferred embodiment of the finger guide device, a pressure responsive motion with a feedback "click" may be used as a tactile (and audible) feedback signal to inform the user when the finger is in the guide and applying the appropriate range of contact pressure.

These feedback mechanisms may also be used to correct for misuse of the system. For example, extreme pressure on the sensor or lack of contact pressure may cause scanning problems. Sometimes the subject user may be disappointed by the false rejection rate and may incorrectly conclude that higher finger pressure will cause the system to work better. Too high a pressure can flatten the detail and saturate the sensor and make it unable to accurately resolve the detail. Conversely, a lack of pressure in the form of too light a contact may cause the details to be indistinguishable by the sensor and not produce a good image. In either case, voice commands or sounds or other feedback means known to those skilled in the art may be used to communicate the need to relax the grip or even squeeze more strongly. A voice or sound or other feedback device may communicate to the subject the need to relieve the contact pressure or lift the finger slightly. Another possibility is to move the sensor up and down slightly in the finger guide device sensor window, either manually or automatically using a feedback control loop and actuator system, such devices being known to those skilled in the art of electromechanical feedback control systems.

A preferred method of implementing the invention is to assemble the sensor and finger guide device designed to work together as a unit, i.e. a system. This requires that the sensor be constructed to operate on a circuit board that likewise contains additional supporting circuitry for its application. The combination of the finger guide device, sensor, sealing gasket and printed wiring board with mounting means may be mounted in the housing of a stylus or pen. Thus, the subassembly can be placed in a variety of different types of stylus or pen housings for its application.

The finger guide device and system for author fingerprint matching of the present invention may be combined with other biometric matching methods to provide a more secure overall result. Examples include, but are not limited to, facial recognition, additional fingerprints, iris recognition, or retinal scanning. In another example, dynamic signature authentication or "DSV" captures and digitizes a plurality of static and dynamic signature elements during the actual provision of a signature (signature) and statistically analyzes individual parameter indicators of these elements for comparison with identified stored parameter data compiled with previously provided signature data (signature template or even a set of identified signature templates). A match may result in the authentication or identification of the subject by the signature he provides. Various methods are known to those skilled in the art to perform such dynamic signature recognition, one example of which is given and claimed in U.S. Pat. No. 5,559,895(Lee et al), entitled "adaptive method and System for real-time authentication of dynamic signatures", in which measurements in the form of "personalized features" measured statically and dynamically are compared with registered signature features to provide "accurate signature recognition". And the patent and prior art are incorporated herein by reference.

There also arises a need to verify from a remote location that a known signer has actually provided its signature rather than an alternative non-ideal wording such as the sentence, "i object" or "i do not agree". In 2002, the company fraud and liability act, also known as the Sarbanes-Oxley law, included a requirement that certain officers in the public community warrant the required financial statement documents; also, the community may require support authentication of key management personnel at the remote operating location. Such documents often have a strict time frame and therefore need to be completed with the ability to support the electronic signature process. The internet-driven need to facilitate many other forms of remote commerce provides an equally acute incentive to require a method of certifying that a truly legitimate signature has been provided, including the "requirement for federal agencies to adopt and utilize digital signatures and encourage the use of digital signatures in private electronic transactions" performed by the united states law, known as usessignbill, which supports the validity of electronic or "digital" signatures, which was passed in 10 months of 2000. Using a paperless system, a fingerprint sensing pen system would not itself prevent such an individual from writing "i refuse to sign" or some other sentence rather than expressing a signature that he agrees to thus express his will. Detecting such anomalies would require manual review of each of the provided signatures (and perhaps even comparison of submitted "signature cards"), which is also prone to manual error or negligence. Accordingly, another preferred embodiment of the finger guide device of the present invention resides in the combination of a fingerprint authentication and identification system with a dynamic signature verification system for confirming that the authenticated subject actually signed a valid version of his signature.

The signatory may be coerced in writing or signing; for example, a crime may be underway in which the author is under the gunpoint and forced to sign. In this case, it is desirable for the author to have a different emergency finger registered as an emergency signal indicating that writing is under duress or even illegally forced. In this case, the system cannot match the enrolled fingerprint, but it will recognize a match with the writer's emergency finger and recognize that such a match indicates that the subject writer is in distress. The subject author may refer to this specially registered finger as his "911" finger. Such an emergency or 911 finger match may be processed as an instruction to trigger a so-called "silent alert" to provide assistance (e.g. police assistance) to the subject author. Furthermore, the system, rather than denying the author, can alternatively be equipped to fail or otherwise delay the transaction for urgent assistance (e.g., police) for reasons other than the subject's author being unable to authenticate, such that the transaction cannot be completed or delayed, which reduces the risk to the subject's author.

Fingerprint sensors or scanners use various schemes to sense and capture image data detailing fingerprint features. In this discussion, the use of the words finger and fingerprint is the same and equivalent to the use of the word thumb or thumb fingerprint and refers to the growth of minutiae or living tissue outward to become surface minutiae on any finger of any left or right appendage of the subject user. In this discussion, if the subject user is referred to as he or she or his or her, the use of these words is the same and equivalent, without any designation of gender.

For a fuller understanding of the finger guide device of the present invention, reference is made to the following detailed description and accompanying drawings, in which the presently preferred embodiments of the invention are shown by way of example. As the present invention may be embodied in many forms without departing from the spirit of the essential characteristics thereof, it is expressly understood that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention. Throughout the description, like reference numerals refer to like parts throughout the several views.

Brief description of the drawings

FIG. 1 is an exploded view assembly of a preferred embodiment of the finger guide device of the present invention including a finger cup, gasket, sensor and printed circuit board for mounting over the ink cartridge in the upper and lower housings of an ink pen stylus;

FIG. 2 discloses a preferred embodiment of the finger guide device of FIG. 1 mounted in a stylus used to authenticate and identify a subject user writing, wherein the subject uses the finger guide device to position substantially the same relevant portion of a finger on a fingerprint sensor when holding a pen;

FIG. 3A discloses a side view of a preferred embodiment of a finger guide device for use with the stylus of FIG. 1 that includes the finger guide device of the present invention, the stylus being wireless; and FIG. 3B discloses a side view of a second preferred embodiment of a finger guide device for use with the stylus of FIG. 1 that includes the finger guide device of the present invention, the stylus being wired;

FIG. 4A discloses a top view of a preferred embodiment of the finger guide device for use with the stylus or pen of FIG. 1 and a finger placed thereon, the finger being optionally and naturally positioned on the finger guide device to enable matching of relevant portions of a fingerprint aligned with the fingerprint sensor; and FIG. 4B discloses a side view of a steeply sloping forward slope of the finger guide device aligning the finger such that the relevant portion of the finger is aligned with the fingerprint sensor;

FIG. 5A discloses a preferred embodiment of a stylus that includes the finger guide device of the present invention and a fingerprint sensor mounted to the grip of the stylus for signature capture pads; and FIG. 5B discloses a preferred embodiment of a pen for use in a point-of-sale payment terminal to sign a shopping receipt, including a finger guide device and a fingerprint sensor mounted to a grip of a stylus of the pen;

FIG. 6A discloses an additional preferred embodiment of an assembly drawing of an electronic stylus that includes the finger guide device of the present invention and a fingerprint sensor mounted in alignment with and mounted to the stylus holder to be used with a computer's handwriting digitizing pad; and figure 6B discloses a further preferred embodiment of figure 6A comprising an electronic stylus comprising a finger guide device and a fingerprint sensor mounted to the grip of the electronic stylus for use with an electronic digitizer pad.

Detailed Description

Referring now to the drawings, in FIG. 1, the finger guide device 12 is shown directly beneath the upper cover 22 at the top of the exploded view and contains a number of preferred elements. These include the left and right sides which are steeper than the front and rear and have concave features, particularly in the area adjacent the fingerprint sensor 16. The front of the finger guide device is concave from the sensor window to the top ridge and has a shape derived from a set of short radii to form its substantially concave profile. The posterior radius creates the least steep concave profile and serves to cup the preferred fingerprint and the finger or finger portion between the rest of the finger near the body. The end of the finger guide device furthest from the fingernail contains a continuous feedback ridge but is not intended to use the finger joint or the skin ridge underneath the joint as a way to locate the finger adjacent to the sensor 16.

The sides of the finger guide device form a recess to receive a user's finger. Accordingly, the side of the finger guide device has the same basic shape as the finger. In a first preferred embodiment of the finger guide device of the present invention, the sides are concave with varying radii of curvature. This includes a relatively short concave radius (or relatively steep slope) at the front of the finger guide device where the tip of the finger just below the nail contacts or is near the front of the finger guide device, and a longer radius concave shape (or less steep slope) adjacent the opposite side of the sensor where the guide extends over the finger toward the body. In the area of the fingerprint sensor, the sides are very steep to keep the finger centered laterally. In summary, the finger guide device is sized for a typical finger, but is adaptable to a wide range of finger sizes, as it only contacts a small portion of the finger or digit. The finger guide device 12 contains a window for the sensor 16 and a drive ring 17 to reveal these elements aligned with the relevant portion of the subject digit or finger. An AES3400 sensor or an AES3500 sensor, both produced by AuthenTec corporation of melbourne, florida, may be equally suitable for use as a fingerprint sensor to sit in this window. This window may be sufficient for housing the drive ring required for the particular type of sensor (shown) or it may cover the drive ring and replace the conductivity provided by the drive ring with its own conductivity. In the field of possible preferred embodiments, this may also be the case, and its performance is equivalent, the only significant difference being aesthetics. In fig. 1, the drive ring 17 is equally exposed and the finger guide device 12 is used as a supplement to the drive ring 17 and is conductive. In the field of possible preferred embodiments, a window opening may not be necessary for a particular type of fingerprint scanner or sensor; however, alignment is a necessary factor for all preferred embodiments.

The sensor surface lies on a plane and the window top is in the lowest part of the recess of the finger guide device 12 and on the same adjacent plane; however, the exact positioning using this plane is not critical to performance, as long as the subject finger is able to contact the finger guide device 12 and the sensor 16. The compliant nature of a live finger facilitates this within appropriate limits. In some cases, performance may be further improved by adjusting the fingerprint sensor plane up or down to change the fingerprint image characteristics. Slight utility is gained from the best choice of vertical position, and the finger guide device of the present invention works well over a range of positions.

A gasket 14 (or equivalent protective means) is provided to keep oil, fluid, dirt, or other undesirable material away from the sensor lens and circuit board. The sensor 16 is made of a material that is impervious to solvents and other undesirable contaminants. Other protective materials may be used in place of the gasket, such as a conformal coating applied in liquid form that cures or partially cures to form a protective barrier. The present invention may operate with a variety of circuit board protection devices available and known to those skilled in the art. The invention may not have a protection device.

The finger guide device 12 contains one or more mounting projections, which in the exemplary preferred embodiment are shown as opposing and adjacent. These projections are used to align the finger guide device 12 with the sensor 16 and the gasket 14 with its printed circuit board 18 or other mounting means, and to mount the subassembly of the sensor 16, gasket 14 and finger guide device 12 in a pen or stylus housing, including the upper cover 22 and the mating lower cover 26. This may be assisted by any suitable mounting means known to those skilled in the art.

The front portion of the guide serves as a stop and position reference designed to contact the fingertip or thumb under the nail and avoid positional differences that may be caused by differences in the length of the finger or thumb nail. This is a significant advantage over devices that clip on or through the top (fingernail) side of the finger.

Figure 2 shows the finger guide device 12 and fingerprint sensor 16 system in the housing of the stylus 10. The finger guide device 12 is shown and the elements shown include left and right sides steeper than the front and back sides adjacent the sensor and having a concave feature. The front portion is concave from the sensor window to the top ridge and has a shape taken from a set of short radii to form its substantially concave profile. The fingertip will contact this front portion of the finger guide device 12. The posterior radius creates the least steep concave profile and serves to cup the preferred fingerprint and the finger or finger portion between the rest of the finger near the body. The end of the finger guide device 12 furthest from the fingernail contains a continuous feedback ridge but is not intended to use the finger joint or the skin ridge underneath the joint as a way to locate the finger adjacent to the sensor 16.

The finger guide device 12 contains a window for the sensor 16 to reveal itself to the subject digit or finger. This window may be sufficient for housing the drive ring required for the particular type of sensor (shown) or it may cover the drive ring and replace the conductivity provided by the drive ring with its own conductivity. In the preferred embodiment, this may also be the case, and its performance is equivalent, the only significant difference being aesthetics. In FIG. 2, the drive ring surrounding the fingerprint sensor 16 is equally exposed and the finger guide device 12 is used as a supplement to the drive ring and is conductive. The present invention does not have an open window for a particular type of scanner or sensor. Examples may include, but are not limited to, optical scanners or sensors and certain ultrasonic sensors.

FIG. 3A discloses a side view of the preferred embodiment of the stylus of FIG. 1, including the finger guide device 12 of the present invention, a wireless stylus 10A; and FIG. 3B discloses a side view of a second preferred embodiment of the stylus of FIG. 1 that includes the finger guide device 12 of the present invention, with the stylus 10B wired. The finger guide device is disclosed as being off the top of the upper cover 22. A grip pad 29 made of a soft and frictional (relatively high coefficient of friction) material intended to provide a more comfortable and stable grip is disclosed. This non-slip gripping surface attached to the lower cover 26 helps prevent stylus mobility when the user removes and replaces a finger in the finger guide during registration or on a second attempt after being mistakenly rejected. Suitable flexible materials having a high coefficient of friction are known to those skilled in the art and include, but are not limited to, rubber, polyurethane-based materials, and suede leather.

FIG. 4A discloses a top view of the preferred embodiment of the finger guide device 12 of FIG. 1 with a finger placed thereon, the finger being positioned onto the finger guide device 12 so that the relevant partial images can be matched; and figure 4B discloses a side view of the steep front slope 27 of the finger guide device that is aligned with the finger so that the relevant part of the finger will be aligned with the fingerprint sensor.

FIG. 5A discloses another preferred embodiment of a stylus 10 comprising a finger guide device 12 and a fingerprint sensor 16 mounted to the stylus holder for signature capture pads typically used as part of a payment processing system; and FIG. 5B discloses another preferred embodiment of a pen 34 that includes the finger guide device 12 and the fingerprint sensor 16 mounted to the pen grip for use in a point-of-sale payment terminal where the purchaser signs a receipt using a pen stylus while positioning a finger using the finger guide device of the present invention.

FIG. 6A discloses another preferred embodiment of an assembly view of an electronic computer input stylus, which includes the finger guide device 12 and the fingerprint sensor 16 mounted to the stylus grip for writing a digitizing device such as an electronic digitizing pad 33 (shown in FIG. 6B) or a tablet computer; and figure 6B discloses a preferred embodiment of an assembled electronic computer input stylus, which when used with its corresponding electronic digitizing pad 33 to capture handwritten content such as drawings, text or signatures for computer processing such as image capture and storage or in conjunction with fingerprint authentication for dynamic signature authentication to biometrically authenticate a user in combination, includes the finger guide device 12 and the fingerprint sensor 16 mounted to the grip portion of the stylus 10. This further preferred embodiment of the invention uses a second secure biometric authentication method for fingerprint authentication. In another preferred embodiment of the present invention, the use of Dynamic Signature Verification (DSV) in conjunction with a finger cup device and a fingerprint authentication or identification system is intended for use in confirming that the signer of an authenticated fingerprint has indeed signed his signature to indicate a legitimate expression of his consent and willingness, rather than writing an objection sentence or providing another meaningless sentence.

In yet another preferred embodiment of the present invention, it may be desirable for the author to have a different emergency fingerprint that is registered as an emergency signal finger to signal to the system that the writing was done under duress or even illegally forced. In this case, the system will not be able to identify the expected enrolled fingerprint, but will identify a match with the author's designated emergency finger, which may be interpreted as the author requesting emergency assistance to be provided. This emergency fingerprint match will be used to trigger a "silent alert" to provide emergency assistance to the author. As an alternative to denying the subject author, the system would be programmed to fail or communicate a message explaining other reasons the author is unable to authenticate and simultaneously disable or delay approval of the signature transaction to await emergency assistance, this approach being intended to reduce the risk of harm to the subject author under duress. This additional preferred embodiment, as well as the previously disclosed alternative embodiments of the DSV, include the use of a circuit board 31 and stylus tip 32 to form a subassembly 30 that communicates wirelessly with an electronic digitizer pad 33 shown in fig. 6B. This subassembly is described in detail in U.S. patent 5,576,502 and other patents that should be referenced therein, all of which are incorporated herein by reference. Other equivalent subcomponents and subsystems designed to communicate with an electronically operated digitizing pointer and handwriting capture pad or board are known to those skilled in the art of computer handwriting capture devices and systems. This additional embodiment uses subassemblies manufactured by WACOM limited. In this further embodiment, the circuit board and stylus subassembly 30 replaces the ink cartridge 24 shown in fig. 1 and this replacement makes the finger guide device enabled electronic computer input stylus compatible with computer hand-written digitizing pads using this wireless communication method between stylus and pad. Figure 6A discloses an exploded view of the finger guide device fingerprint sensor system in a stylus housing. The finger guide device 12 is shown and the elements shown include left and right sides that are steeper than the front and back and have a concave character. The front portion is concave from the sensor window to the top ridge and has a shape taken from a set of short radii to form its substantially concave profile. The fingertip will contact this front portion of the finger guide device 12. The posterior radius creates the least steep concave profile and serves to cup the preferred fingerprint and the finger or finger portion between the rest of the finger near the body. The end of the finger guide device furthest from the fingernail contains a continuous feedback ridge but is not intended to use the finger joint or the skin ridge underneath the joint as a way to locate the finger adjacent to the sensor 16. The finger guide device 12 contains a window for the sensor 16 to reveal itself as being aligned with the subject digit or finger. This window may be sufficient for housing the drive ring required for the particular type of sensor (shown) or it may cover the drive ring and replace the conductivity provided by the drive ring 17 with its own conductivity. In a further preferred embodiment, this may also be the case, and its performance is equivalent, the only significant difference being aesthetics. In fig. 6A, the drive ring is equally exposed and the finger guide device is used as a supplement to the drive ring and is conductive.

Fig. 6B discloses the electronic computer input stylus writing mechanism of fig. 6A in radio frequency electronic communication with the electronic digitizing pad 33 of fig. 6B, which sends an electrical signal containing information about the handwriting to the computer. A stylus may be used for handwriting, which is digitally captured and transferred to a computer and in this application it is preferred to try to use a conventional computer mouse, since a mouse is not suitable for being able to provide handwriting. Furthermore, a stylus having this configuration may also be used as a computer pointing control device and a handwriting capture device, but, as observed, the mouse is limited to pointing control devices and is not a stylus. The electrical signal containing information about the fingerprint can also be transmitted to the computer via the digitizing tablet by wireless signal transmission and reception, via optical transmission of data, or by a separate cable in electronic communication with the computer, before or during use of the stylus for its purpose, and with no significant difference in the results and usefulness of the invention.

There are various patent applications referenced throughout by application number and inventor. The disclosures of these applications are hereby incorporated by reference in their entirety into this specification in order to more fully describe the prior art.

It is evident that many alternatives, modifications and variations of the positioning device of the present invention will be apparent to those skilled in the art in light of the disclosure herein. The scope of the present invention is intended to be determined by the appended claims rather than by the words of the foregoing description, and all such alternatives, modifications and variations which form a combined equivalent are intended to be included within the spirit and scope of these claims.

Parts list

10 contact pin

12 finger cup

14 gasket

16 fingerprint sensor

17 drive ring

18 printed circuit board

22 upper cover

24 ink box

26 lower cover

29 clamping pad

30 subassembly

31 circuit board

32 stylus tip

33 electronic digital pad

Claims (23)

1. A finger guide device for mounting on a fingerprint sensor placed in the grip of a stylus or pen, the finger guide device having a concave side having the same basic shape as a finger, the finger guide device guiding the finger onto the sensor in substantially the same position in an axial direction and in a transverse direction, the finger guide device enabling substantially the same relevant part of the finger to rest on the fingerprint sensor in a stable position in a repeatable manner each time the stylus or pen is used to generate writing, the finger guide device reducing the occurrence of "false rejection" situations for identifying or authenticating a user of the stylus or pen.

2. The finger guide device of claim 1 having convex sides with varying radii of curvature, such radii on the front side being designed for substantially the same relevant portion of a finger positioned on the finger in an area on the center of the sensor, the area being in the range from 0.20 inches to 0.90 inches from the underside of the nail.

3. The device of claim 1 having an outer ridge that causes a unique tactile feedback to signal to the subject that the finger is not properly positioned on the sensor.

4. The device of claim 1 having surface friction characteristics to allow the finger to easily slide towards a global minimum position and stabilize in that position, which is also approximately related to the correct position on the sensor.

5. A device according to claim 1, having a higher thermal conductivity than the rest of the pen or stylus so that heat is transferred out of the skin by the device more rapidly than through the rest of the pen, so that the device has tactile properties that feel cooler when touched than the rest of the pen, thereby indicating to the author that the finger is placed in the correct area.

6. The apparatus of claim 1 in combination with one or more mounting projections for alignment and attachment to a stylus.

7. The finger guide device of claim 1, wherein the stylus is electronic and communicates with a hand-written digital pad.

8. A finger guide device for mounting in alignment with a fingerprint sensor placed in the grip of a stylus or pen, the finger guide device enabling capture of relevant parts of a fingerprint when the pen or stylus is used during an enrollment procedure, the finger guide device having the same basic shape as a finger, the finger guide device guiding the finger onto the sensor in substantially the same position in an axial direction and in a transverse direction, the finger guide device enabling the resting of substantially the same relevant parts of the finger in a stable position in a repeatable manner each time the stylus or pen is subsequently used to generate a writing, the finger guide device reducing the occurrence of "false rejection" situations for identifying or authenticating a user of the stylus or pen.

9. A system according to claim 8, having feedback means to assist the subject in placing their finger in the correct position in the finger guide device.

10. A system according to claim 8, having feedback means to assist the subject in placing their finger in the correct position in the finger guide device and applying the correct pressure.

11. The system of claim 8 having a protrusion to assist the subject in placing their finger in the correct position in the finger guide device.

12. A system according to claim 8, having Braille to indicate to the subject to place their finger in the correct position in the finger guide device.

13. The system of claim 8, wherein the finger guide device or finger guide device surface is conductive or partially conductive to convey the necessary electrical signals, frequencies or potentials to human tissue to facilitate improved sensor operation.

14. A system according to claim 8, wherein the finger guide device or the peripheral area is marked with a visual indicator or even a drawn fingerprint to indicate where the finger is placed.

15. The finger guide device of claim 8, the stylus being electronic and in communication with a hand-written digital pad.

16. An apparatus for positioning a finger on a fingerprint scanner, the finger guide apparatus comprising:

a. a finger guide device having a substantially concave shape sized to receive a finger or thumb, the finger guide device having a front portion with at least one ramp that abuts a portion of the finger or thumb beneath a finger or thumb nail; and

b. a scanner adjacent the finger guide device;

whereby the device guides a finger onto the sensor in substantially the same position in the axial direction and in the transverse direction, the finger guide device enabling substantially the same relevant part of the finger to rest in a stable position on the fingerprint sensor in a repeatable manner each time the stylus or pen is used to generate a writing, the finger guide device reducing the occurrence of "false rejection" situations for identifying or authenticating a user of the stylus or pen.

17. The finger guide device of claim 16, wherein the guide includes a pair of sides for centering the finger or thumb on the scanner and a back for receiving a portion of the finger extending rearwardly past the sensor.

18. The finger guide device of claim 16, wherein the concave portion of the guide has the basic shape of a finger.

19. The finger guide device of claim 16, wherein the stylus is electronic and communicates with a hand-written digital pad.

20. A finger guide device according to claim 16, wherein the stylus is for use in a system capable of dynamic signature authentication for verifying that the author has signed a signature belonging to the author.

21. The finger guide device of claim 16, wherein the stylus is used in a system that enables dynamic signature authentication, wherein said dynamic signature authentication system may also be used as a way to authenticate or identify an author.

22. The finger guide device of claim 16, wherein the subject has registered a second emergency finger fingerprint for communicating an emergency distress signal, the match of which is a signal for causing the system to respond differently.

23. A finger guide device according to claim 16, wherein the stylus serves as a computer pointing control device capable of authenticating a subject user before or during control of the movement of the pointing device.