A User Interface Using Fingerprint Recognition- Holding Commands and Data Objects on Fingers -Atsushi Sugiura Yoshiyuki KosekiC&C Media Research Laboratories, NEC Corporation4-1-1 Miyazaki, Miyamae-ku, Kawasaki 216-8555, JAPANE-mail: [email protected] paper describes a new user interface, called afingerprint user interface (FUI), which employsfingerprint recognition. While the unique feature patternsof fingerprints have mainly been used for personalidentification, the FUI is unique in that it uses not onlythe differences among fingerprint patterns of differentpersons, but also the differences among the ten fingers ofa single person. In the FUI, the system identifies thefinger that has operated (touched) an input devicethrough pattern matching of fingerprints and it performsthe task assigned to the identified finger. Since users areable to specify different tasks by using different fingers,they feel as if commands and data objects were actuallyheld on their fingers.KEYWORDS: Fingerprint recognition, multimodal userinterfaces, multi-computer user interfaces, input devices.INTRODUCTIONMost electronic machines, such as computers, industrialcontrol systems and appliances, are designed so that theycan be operated by pushing buttons (keys) or by touchingtouch-sensitive screens with fingers. Although there are alot of opportunities that fingers touch input devices, theinteractions between the fingers and the input devices arevery poor. On a button-based human machine interface,for example, a user’s finger simply provides a trigger forexecuting commands assigned to the button.This paper proposes a new user interface, called afingerprint user interface (FUI), that enhances finger-machine interaction capability by using fingerprintrecognition technique. The system identifies which fingeris being used to manipulate (touch) an input device withfingerprint recognition, and it performs the task that hasbeen assigned to that finger. This framework of a FUIenables a user to virtually hold commands in his/her ownfingers. Since a user is able to indicate differentcommands through the choice of the finger even inpressing a single button, the user can operate the systemas if he/she could transfer the commands, attached tohis/her fingers, to the system. Similarly, the fingers canvirtually hold data objects. With the FUI, an objectselected on an editor can be assigned to a specific fingerthat touches a “store in finger” button and it can beinserted into the editor only when the same finger touchesa “get from finger” button. In this case, user’s fingers canfunction as a data storage that exchanges data objectswith the system.In order for the FUI to be able to capture the fingerprintpattern when a finger has touched an input device,fingerprint scanners would naturally have to be includedin the construction of such devices, e.g. on the buttonsurfaces. At present, however, fingerprint scanners areoften too large to be included in that ways within the userinterfaces of such systems as hand-held computers andportable telephones. Nonetheless, in order to test theeffectiveness of the FUI concept, we have developed aprototype FUI system consisting of a notebook computerand an optical-type fingerprint scanner.In the following sections, we first consider the FUI in thelight of related work, and next explain its concept, design,and usage. We also describe our prototype system, andfinally discuss the usability and operability of the FUI.RELATED WORKSince fingerprints have unique feature patterns, they havebeen used for personal identification and authentication.Many security systems and entrance management systemsare based on the fingerprint recognition technique [5] [6].The FUI is the first attempts to apply the fingerprintrecognition technique to the user interface field. It differsfrom the personal identification systems in that it uses notonly the uniqueness of the fingerprint patterns ofdifferent persons but also that of the ten fingers of asingle person.From the viewpoint of user interfaces, a FUI can becategorized as a multimodal user interface [8] thatenables a user to interact with a computer using suchmodalities as speech, gestures, facial expressions and eyedirection [1] [2] [3] [11]. The FUI introduces a newLEAVE BLANK THE LAST 2.5cmOF THE LEFT COLUMNON THE FIRST PAGEFOR US TO PUT INTHE COPYRIGHT NOTICE!Permission to make digital or hard copies of all or part of this work forpersonal or classroom use is granted without fee provided that copies are notmade or distributed for profit or commercial advantage and that copies bearthis notice and the full citation on the first page. To copy otherwise, torepublish, to post on servers or to redistribute to lists, requires prior specificpermission and/or a fee.UIST ’98. San Francisco, CA 1998 ACM 0-58113-034-1/98/11... $5.0071modality, finger types.In the multimodal systems, the speech has been the mostwidely used modality. This is because it is the mostnatural means for human communications and it is able toconvey various types of information. However, thespeech-based interface is inappropriate for the use inpublic places, because it might disturb others and it mightleak the contents of user’s work. Although FUI has lesscapability for conveying information than the speech-based interface, it can be used in public without anytrouble.Pick-and-Drop [10] is a pen-based direct manipulationtechnique for multi-computer environments, whichallows a user to virtually hold a data object in a pen thatdoes not have storage capabilities. In Pick-and-Drop, anobject, pointed by the pen on one display, is bound to thepen ID. When the pen next touches another display, thatobject is moved/copied to it via a network. That is to say,the user can manipulate the object as if it were stored inthe pen.Although the concept of a FUI for object manipulation issimilar to that of Pick-and-Drop, it has severaladvantages. First, the FUI does not require special toolsto manipulate objects, because users’ fingers can be usedin place of the ID-recognizable pen of Pick-and-Drop.Moreover, the FUI does not need the ID management,which is required in Pick-and-Drop. It becomesincreasingly laborious to guarantee the uniqueness ofpen-IDs, when the number of pens increases. Thenecessity of such an ID management task is eliminatedwith the FUI, because of the inherent uniqueness offingerprints; this is an important advantage.Another advantage of FUIs is that a