Abstract:
A computer keyboard supports an ultrasonic user presence detector (UPD) that is rotatable and supported on the upper surface of the keyboard, adjacent to the uppermost row of keys and located adjacent to one corner of the keyboard. The UPD is aimed at an elevation of 20°, and rotates to sweep through an angle of approximately +35° to −20° to be selectively directed toward the most-likely position of an individual using the keyboard, so that the proximity detection error rate is very low. In one embodiment the UPD housing is rotatably supported on a modular interchangeable top secured to the keyboard at the upper margin thereof adjacent to the uppermost row of keys.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation-in-part of U.S. application Ser. No. 13/652,732, filed Oct. 16, 2012, which claims the benefit of filing date priority based on U.S. application Ser. No. 13/136,358, filed Jul. 28, 2011, which claims filing date priority based on Provision Application No. 61/369,301, filed Jul. 30, 2010. 
     
    
     FEDERALLY SPONSORED RESEARCH 
       [0002]    Not applicable. 
       SEQUENCE LISTING, ETC ON CD 
       [0003]    Not applicable. 
       BACKGROUND OF THE INVENTION 
       [0004]    1. Field of the Invention 
         [0005]    This invention relates to a keyboard for use with a computer system, particularly a computer system that requires secure log-in arrangements and the ongoing presence of the logged-in individual at the keyboard. 
         [0006]    2. Description of Related Art 
         [0007]    As computer systems have become more and more essential to the operation of businesses and institutions, there has been a concomitant increase in the number of terminals, work stations, desktop computers and the like that are connected to the computer system that serves the business or institution. One of the many uses of a central computer system is the storage of records that should be held confidential, such as medical data regarding individuals, personnel records, financial records and transactions of the business or institution, payroll records, and the like. For this and other reasons there is a definite need for some form of security system to limit access to confidential information, not to mention access to computerized functions such as payroll, billing, and the like. On the other hand, it is necessary to grant access of some sort to a large number of individuals so that they may carry out their assigned tasks which often involve interaction with the computer system. The confluence of the requirement for confidentiality and the need to grant access has lead to a proliferation of security measures and systems that are designed to recognize individuals who are authorized to have access to the computer system and at least some portion of its records and functions, while denying access to those individuals who endeavor to gain access to the system without authorization. 
         [0008]    The most common security devices and measures currently in use include passwords assigned individually to each employee, biometric sensors such as fingerprint readers, iris scanners, facial recognition, and the like, electronic scanners such as RFID or NFC-RFID for security cards or badges, and auto locking sonar transceivers to detect whenever an authorized individual leaves the vicinity of the computer or terminal where authorized access took place. See for example the description of an auto-locking sonar system in U.S. application Ser. No. 13/136,358, filed Jul. 28, 2011, which is incorporated by reference herein in its entirety. In this system the ultrasonic user presence detector is mounted on the keyboard that is used in conjunction with a computer system or computer terminal, and is aimed in a fixed direction toward the expected position of the keyboard user. 
         [0009]    However, it has been observed that in some situations the keyboard user may move laterally away from the keyboard while continuing to use the keyboard and wanting to remain logged in to the system. For example, making or answering a telephone call in an office setting may entail moving away from the axis of the detector. In a medical setting, operators of medical test equipment may use one hand to operate the test device while entering control commands and data on the keyboard with the other hand. Likewise, it is now commonplace for medical personnel to interview and examine a patient while entering data into a keyboard to generate accurate electronic medical records as information is developed. Such movement away from the user detector axis may easily cause the system to command a log-out, requiring the user to log in to the system repeatedly. This is both inefficient and annoying to the user. 
       BRIEF SUMMARY OF THE INVENTION 
       [0010]    The present invention generally comprises a computer keyboard for use with a terminal or workstation or desktop computer setup. A salient feature of the keyboard is that it supports an ultrasonic user presence detector (UPD) that is rotatable and may be aimed by the user as needed when the user changes locations adjacent to the keyboard. 
         [0011]    In one preferred embodiment, the UPD comprises an ultrasonic detector that is a transceiver that emits an ultrasonic beam and detects reflected energy returned to the transceiver. The ultrasonic detector is mounted in a small housing that is rotatably supported on the upper surface of the keyboard, adjacent to the uppermost row of keys and located adjacent to one corner of the keyboard. The ultrasonic detector is aimed at an elevation angle of approximately 20°. The housing is rotatable and may be selectively directed to sweep through an included angle of approximately +35° to −20° with respect to an axis extending transversely to the midpoint of the keyboard. In this way the sensor is directed toward the most-likely position of an individual using the keyboard, so that the proximity detection error rate is very low. 
         [0012]    In another embodiment the invention provides a keyboard assembly having a unique modular system, designed to have custom-designed interchangeable tops to accommodate various discrete input technologies, as described in copending U.S. application Ser. No. 13/652,732, filed Oct. 16, 2012, which is incorporated herein in its entirety. This modular design is tooled to accommodate up to seven different combinations of technologies, as well as the UPD described above. In this embodiment the UPD housing is rotatably supported on a flexible interchangeable top that is secured to the keyboard at the upper margin thereof adjacent to the uppermost row of keys. The housing is rotatable and may be selectively directed to sweep through an included angle of approximately +35° to −20° with an axis extending transversely to the midpoint of the keyboard. In this way the sensor may be directed toward the most-likely position of an individual using the keyboard, so that unintended log-out from the system is avoided. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0013]      FIG. 1  is a plan view showing one embodiment of the angularly articulatable ultrasonic user proximity sensor of the present invention. 
           [0014]      FIG. 2  is an exploded perspective view showing the major components of the articulatable ultrasonic user proximity sensor of the invention. 
           [0015]      FIG. 3  is a plan view of one embodiment of the invention in which the articulatable ultrasonic user proximity sensor is mounted on a replaceable, customizable keyboard cover. 
           [0016]      FIG. 4  is an enlarged partial perspective view of the keyboard cover depicted in  FIG. 3 . 
           [0017]      FIG. 5  is a perspective view of the bottom of the outer housing component of the invention. 
           [0018]      FIG. 6  is a perspective view of the bottom of the component assembly of the articulatable ultrasonic user proximity sensor. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0019]    The present invention generally comprises a computer keyboard for use with a terminal or workstation or desktop computer setup. An important aspect of the keyboard is an ultrasonic user presence detector (UPD) extending from the upper surface thereof and that is rotatable to be aimed by the user as needed when the user changes position adjacent to the keyboard. 
         [0020]    With regard to  FIG. 1 , a computer keyboard  11  has a full complement of alphanumeric keys  12 , a numerical keypad  13 , and a row of function keys  14  adjacent to the top edge  16  of the keyboard. This keyboard layout is typical but not necessarily limiting. The keyboard  11  also includes opposed sides  17  and a bottom edge  18 . A salient feature of the keyboard  11  is the provision of an ultrasonic user presence detector  21  projecting upwardly from the upper surface of the keyboard. The detector  21  is located in an area of the keyboard that is adjacent to the corner formed by the top edge  16  and one of the sides  17 . 
         [0021]    The detector  21  has a beam axis A along which the ultrasonic beam is generated, and thus defines the direction of maximum sensitivity of the detector  21 . The axis A is directed at an elevation angle of approximately 20° (with respect to the horizontal surface that supports the keyboard). Furthermore, the detector is rotatable about a generally vertical axis through the range of azimuth positions that a typical user would occupy while using the keyboard. Thus, as shown in  FIG. 1 , the axis A 1  of the detector may be directed along a line that intersects the central portion of the keyboard user&#39;s body B 1  (the head and torso as viewed from above) when the user is generally centered in front of the keyboard, thus forming an included angle of approximately 35° with an axis M that bisects the top and bottom edges of the keyboard  11 . However, the user may move laterally to the left (as seen in  FIG. 1 ) to a new position B 7 , in which the user&#39;s right hand may operate the keyboard  11  while the left hand is used for other tasks; e.g., operating another electronic or medical device, holding a telephone receiver, or the like. In such circumstance the detector  21  may be rotated by the user so that the detector axis (A 2 ) remains directed to the central portion of the user&#39;s body B 7 , thus forming an included angle of approximately −20° with the transposed axis M. This angular range is illustrative rather than limiting in scope, and is provided to suggest a practical range of rotation for diverse keyboard uses. 
         [0022]    The keyboard may also be provided with built-in security devices  25 , such as a fingerprint reader or other biometric or electromagnetic user authentication devices, so that a user may be verified before the system grants access through the terminal After verification and log-in, the ultrasonic user presence detector operates continuously to assure that the user has not departed from the vicinity of the keyboard  11 . Following a successful log-in to the system, if the user moves laterally in front of the keyboard the detector  21  may be rotated to remain directed at the user and avoid an unintended log-out event. As soon as user presence is no longer detected (or after a preset time delay to avoid false negative actions), the ultrasonic detector will send a signal through the same channel used by the keyboard to communicate with the computer system. The UPD signal will cause the computer system to log out of the user access mode at the terminal served by the keyboard  11 , so that the opening into the system is quickly blocked before snooping or hacking can occur. 
         [0023]    The detector  21  may be located at other positions on the keyboard, such as the medial area adjacent the top edge, or at the top edge corner opposed to the one shown, as long as it is supported by the keyboard itself and is aimable at the expected range of positions of the user at the keyboard. 
         [0024]    With regard to  FIGS. 3 and 4 , another embodiment of the invention provides a keyboard assembly having a unique modular system designed to have flexible interchangeable tops  51  to accommodate various discrete input technologies, as described in copending U.S. application Ser. No. 13/652,732, filed Oct. 16, 2012, which is incorporated herein by reference in its entirety. Each cover  51  has a rectangular plan layout that fits in complementary fashion over an opening in the keyboard assembly that extends laterally therein adjacent to the uppermost row of keys. Furthermore, the interchangeable covers  51  are provided with features that either embody portions of the security sensor modules, or accommodate modules placed in the keyboard assembly, or enable communications to the module(s). 
         [0025]    In addition, any of the interchangeable covers  51  may support an ultrasonic user presence detector  21 . For this purpose, a cover  51  may be provided with a circular opening  52  adjacent to one end  54  thereof. A plurality of standoffs  53  depend from the inner surface of the cover  51  and are arrayed about the opening  52  in particular positions to support the detector assembly  21 , as described below. 
         [0026]    With regard to  FIG. 2 , the UPD assembly  21  includes a support base  61  having a generally flat cylindrical configuration, with a trio of tabs  62  extending radially outwardly therefrom. Each tab  62  includes a mounting hole  63  for securing the tab to a respective standoff  53  with screws or other fasteners, so that the base  61  is in effect secured to the underside of the cover  51  and centered with respect to opening  52 . The base includes a cylindrical sidewall  65  that defines an outer annular flat  64  extending perpendicular to the cylindrical axis. A stepped annular shoulder  66  defines an inner annular flat  68 , and there is a central opening  67  extending axially through the base  61 . Protruding upwardly from the outer annular flat  64  is a spring arm  69  that is integrally molded with the other structures of the base  61 . An annular guide track  71  is disposed concentrically within a portion of the sidewall  65  and protruding axially from the annular flat  64 . The guide track  71  subtends an angle that is substantially similar to the rotational freedom of the detector  21 , as described below. 
         [0027]    The UPD assembly  21  further includes an outer housing  70  having a disk-like base  72  with a stepped annular periphery defining an outer flange  73 . The base  72  is disposed with the stepped periphery extending close-fit through the opening  52  in cover  51  in slidable rotating fashion, and the outer flange  73 , which is wider than the diameter of opening  52 , is disposed within the cover  51 . This engagement prevents removal of the UPD assembly  21  from the cover  51 . With additional reference to  FIG. 5 , the base  72  includes a quadrilateral opening  74 , and a pair of opposed sidewalls  76  extend upwardly from opposed sides of the opening  74 . A cylindrically arched top  77  joins the sidewalls  76 , and rear end wall  78  spans the sidewalls and top. The sidewalls  76 , end wall  78  and arched top  77  define an enclosure that extends upwardly from the cover  51  and has a front opening. 
         [0028]    The bottom surface of the base  72  is provided with a plurality of fastener pads  79  depending from the lower surface of the base and having holes for screw fasteners or the like. An arcuate channel  81  is formed in the lower surface of the base  72  and configured in complementary fashion to guide track  71 . The guide track is engageably in the channel  81  in slidable fashion, and serves to guide and limit the angular extent of rotation of the assembly  21 . The lower surface of the base is also provided with a plurality of shallow grooves  83  extending generally radially with respect to the common cylindrical axis. The grooves are positioned to be snap-engageable with a detent pad supported on the spring arm  69 , thereby providing a position-click detent at selected angular excursions of the housing. For example, the grooves  83  may be positioned to define the +35° and −20° limits of angular motion of the housing, as well as a midpoint such as 0°. Other angular settings made be made by changing the angular spacing of the grooves  83 , as needed for particular keyboard uses and applications. 
         [0029]    Extending outwardly from the outer flange  73  is a stop lug  84  that is positioned to impinge on one of the standoffs  53  to provide a positive stop for angular motion of the detector  21  at its designed limit of rotation, as shown in  FIG. 6 . 
         [0030]    Another component of the UPD assembly  21  is an ultrasonic transceiver assembly  91  having a disk-like active transceiver face  92 . The enclosure  76 - 78  of the outer housing is formed in complementary fashion to the ultrasonic transceiver assembly  91  to surround the assembly  91  and expose the transceiver face  92  to emit an acoustic beam as shown in  FIG. 1 . A pair of mounting tabs  93  extend outwardly from opposed sides of the device  91 , and are positioned to register with two of the fastener pads  79 , so that device  91  may be joined fixedly to the outer housing  70 . The device  91  is also mounted on and secured to an underlying PCB  94  that connects to and drives the ultrasonic transceiver assembly. The PCB  94  includes a keyway  96  that engages a lug  97  ( FIG. 6 ) extending from the bottom of the assembly  91 , so that the PCB and the assembly  91  are locked in a fixed angular relationship about the cylindrical axis. A mounting tab  98  extends radially from the PCB and is disposed to register with one of the fastener pads  79  to secure the PCB  94  to the outer housing  70 . Another tab  99  extending from the PCB enables electrical connection to the circuitry and thus to the device  91 . The PCB  94  is located within the recess formed by annular shoulder  66 , and the tabs  93  are located within the recess formed by the sidewall  65 . 
         [0031]    To summarize the assembly of components, the ultrasonic transceiver assembly  91  is mounted on the PCB  94 , and that assembly is secured to the outer housing  70  by means of mounting tabs  93  and  98 . The outer housing  70  is oriented with the enclosure portion  76 - 78  extending upwardly through opening  52  and flange  73  slidably engaging the inner periphery of opening  52 . The support base  61  is secured by tabs  62  to standoffs  53  to support the assembly of components  70 ,  91 , and  94 . The annular guide track  71  engages the arcuate channel  81  of the outer cover base  72  to guide rotational motion of the outer housing  70  and its assembled components  91  and  94 , and the spring arm detent  69  is engageable with one of the shallow grooves  83  to comprise a position-click detent to indicate to the user particular angular settings. The stop lug limits rotation of the assembly in one direction, and the guide track  71  riding in the channel  81  limits rotation of the assembly in the other direction. The support base  61  supports the assembly of components  70 ,  91 , and  94  from below in rotatable fashion, and the outer flange  73  prevents removal of the assembled components upwardly from opening  52 , thus prevent removal while permitting rotation of the UPD  21  to various angles to maintain the aim of the axis of the detector  21  toward the user at the keyboard, as described previous with respect to  FIG. 1 . 
         [0032]    The construction described above with reference to  FIGS. 2-6  is substantially the same for the embodiment of  FIG. 1 , with the exception that a custom modifiable cover  51  is not used, and the opening  52  is formed in the upper surface of the housing of keyboard  12 . 
         [0033]    It may be noted that the detector  21  may be placed at any location on the keyboard that is convenient and available, and the angular range of azimuth angle may be set to encompass the expected range of motion of a keyboard user. Likewise, the elevation angle may be selected empirically to suit the keyboard user and the tasks being undertaken while positioned at the keyboard. 
         [0034]    The foregoing description of the preferred embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and many modifications and variations are possible in light of the above teaching without deviating from the spirit and the scope of the invention. The embodiment described is selected to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as suited to the particular purpose contemplated. It is intended that the scope of the invention be defined by the claims appended hereto.