Abstract:
An interactive whiteboard system allows a user to interact, using a stylus, with a computer and a display. The interactive whiteboard system includes a monitor or projector that duplicates or replaces the computer display, and a capture bar that facilitates, via the stylus and the monitor or projected display, interaction between the user and the computer. One or more transmitters integrated with the capture bar operate to control a power state of a projector or display monitor. The integrated transmitters may operate according to the power state of the mobile device, or may operate according to a command from a button integrated in the mobile device or a command from the computer.

Description:
TECHNICAL FIELD 
       [0001]    The present disclosure relates generally to an interactive whiteboard system. More particularly, the disclosure is directed to a digitizing system for facilitating interaction between a computer and a whiteboard surface, in which the digitizing system operates to control an associated projector or screen. 
       BACKGROUND 
       [0002]    Interactive whiteboard technologies allow a user to interact with a presentation display. In some instances, the interactive whiteboard also allows the capture and storage of handwritten notes. These systems generally accomplish interaction using a digitized writing surface and/or a spatial recognition pen. Typically, electronic whiteboards having digitized surfaces either photocopy the entire writing surface or serve as the actual input device, recording the movements of a pen or stylus along the surface of the board. Spatial recognition pens record the movement of the pen (or other stylus) across a writing surface, which surface typically must include special marking for the pen to recognize its position. Newer systems track the movement of a stylus across any surface using technology embedded in the stylus. One such system, which uses ultrasonic position tracking, is described in U.S. Pat. No. 7,109,979, entitled “System and Method for Recording Writing Performed on a Surface,” and is hereby incorporated herein by reference. In some interactive whiteboard systems, a projector attached to a computer projects an image onto a whiteboard surface, allowing a user to interact with the computer using the stylus. In other interactive whiteboard systems, a flat-panel monitor duplicates or replaces the display of the attached computer, and also allows the user to interact with the computer using the stylus. Additional features of interactive whiteboard systems are described in U.S. Pat. Nos. 6,100,877, 6,104,387, 6,124,847, 6,147,681, 6,177,927, 6,191,778, 6,211,863, 6,217,686, 6,232,962, 6,292,180, 6,310,615, and 7,109,979, each of which is hereby incorporated herein by reference. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0003]      FIG. 1A  depicts an exemplary writing surface, capture bar, charging tray, and stylus that may be used with the presently described system; 
           [0004]      FIG. 1B  depicts a more detailed view of the capture bar depicted in  FIG. 1A ; 
           [0005]      FIG. 1C  illustrates the functionality of the capture bar depicted in  FIG. 1B ; 
           [0006]      FIG. 2  illustrates an embodiment of the presently described system; 
           [0007]      FIG. 4  depicts a block diagram of an embodiment of the presently described system; and 
           [0008]      FIG. 5  depicts a cross-sectional view of the capture bar depicted in  FIG. 1B . 
       
    
    
     DETAILED DESCRIPTION 
       [0009]    The present disclosure relates to a digitizing system for recording movements of a stylus across a surface and, in particular, to a capture bar for use with the system, which capture bar includes an infrared transmitter for transmitting commands to a projector or display associated with the digitizing system. The digitizing system digitizes the movement of the stylus across the surface by tracking the stylus using signals such as infrared signals, ultrasonic signals, and the like. The movements of the stylus across the surface may include the formation or modification of any type of image by the stylus, including printing, drawings, sketching, erasing, etc. The surface across which the digitizing system tracks movement of the stylus may be any suitable surface including, but not limited to, dry erase boards, chalk boards, clipboards, desktops, walls, projection screens, flip chart tablets, and glass panels, regardless of whether any of these surfaces is covered by a material such as paper, glass, metal, or plastic, which can be written upon. The surface is preferably relatively smooth and relatively flat, though the surface may have a small degree of curvature. 
         [0010]      FIG. 1A  illustrates an exemplary portion of a digitizing system  10  in accordance with the present description. The digitizing system  10  includes a capture bar  12  (also known as a tracking and communication unit (TCU)), a writing surface  14 , a stylus  16 , and a stylus charging station  18 .  FIG. 1A  depicts the writing surface  14  as a dry erase board (i.e., a “whiteboard”) though, as noted above, the writing surface  14  may be any desired surface. Although  FIG. 1A  illustrates the writing surface  14  as a vertical surface, it should be noted that the writing surface  14  could also be a horizontal surface, as the orientation of the surface is irrelevant to operation of the digitizing system  10 . The digitizing system  10  tracks the movements of the stylus  16  across the writing surface  14 . However, it is not necessary that the movement of the stylus  16  creates any mark on the writing surface  14  for the system  10  to operate to digitize the movements of the stylus  16 . Moreover, while many of the embodiments described herein are described with reference to a dry erase board such as that depicted in  FIG. 1A , and an accompanying dry erase stylus, the stylus  16  may be any desired stylus. For example, in some embodiments, the stylus  16  operates as a pointing device (e.g., a mouse) and not a marking device, and the system  10  digitizes the movement of the stylus  16  across a projector screen (not shown), which allows the system  10  to be used with a computer (not shown) and a projector (not shown). 
         [0011]    In any event, the stylus  16  is preferably wireless, to facilitate easy movement of the stylus  16  across the writing surface  14 . As described below, the digitizing system  10 , through the capture bar  12 , processes signals received from the stylus  16  in order to track the movement of the stylus  16  across the writing surface  14 . Of course, generation of the signals requires a transmitter and a power source for the transmitter. Thus, the stylus  16  may also include a battery and, in particular, a rechargeable battery. The system  10  includes the charging tray  18  for this purpose. Alternatively, the transmitter in the stylus  16  may receive power through a cable (i.e., a wired stylus). 
         [0012]    Each of the capture bar  12  and the charging tray  18  may be mounted to the writing surface  14 , though the charging tray  18  may also be mounted to any convenient surface, as its presence is not strictly required for proper operation of the digitizing system  10 . In one embodiment, the writing surface  14  is a magnetic surface, such as a dry erase board that includes a steel plate, and one or both of the capture bar  12  and the charging station  18  are mounted to the writing surface  14  by an array of rare earth magnets (not shown). The rare earth magnets preferably exert a strong magnetic force over a short distance, providing sufficient force to hold the capture bar  12  and/or the charging station  18  to the writing surface  14  (or other surface), but allowing relatively easy removal of the capture bar  12  and/or the charging station  18  from the writing surface  14  (or other surface). Of course, the capture bar  12  and/or the charging station  18  may be adhered to the writing surface  14  using any known method including, but not limited to, suction cups, hook-and-loop material, one or more individual magnets, adhesive tape, etc., depending on the writing surface  14 , the permanence of the installation, cost, etc. For example, if the writing surface  14  is a glass window pane, suction cups may be preferable. 
         [0013]      FIG. 1B  illustrates in greater detail an embodiment of the capture bar  12 . In the illustrated embodiment, the capture bar  12  tracks the position and/or movement of the stylus  16  across the writing surface  14  using ultrasonic and infrared signals transmitted by the stylus  16 , and also receives additional information about the stylus  16  in the infrared signal. The capture bar  12  includes two ultrasonic sensors  20  and  22  separated by a fixed distance, D 1 , and an infrared sensor  24 . When the stylus  16  is pressed against the writing surface  14 , the stylus  16  emits both infrared and ultrasonic signals. The infrared sensor  24  receives the infrared signal, which identifies which stylus touched the surface (the system  10  may include numerous styli including, for example, different colors of writing styli, styli using different types of writing elements, styli with different width writing tips, a mouse stylus, etc.) using an encoded signal. The infrared signal received by the infrared sensor  24  also indicates to the capture bar  12  that the stylus  16  transmitted an ultrasonic signal. Meanwhile, the ultrasonic sensors  20  and  22  receive the ultrasonic signal transmitted by the stylus  16 . The capture bar also includes various control buttons  21 , and an infrared (IR) transmitter  23 . The function of the IR transmitter  23  will be described in detail below. 
         [0014]      FIG. 1C  illustrates the concept behind the method used by the capture bar  12  to track the stylus  16 .  FIG. 1C  depicts the stylus  16  at a position, P, on the writing surface  14 . As described above, upon being pressed against the writing surface  14 , the stylus  16  transmits both an infrared signal and an ultrasonic signal. The infrared signal arrives at the infrared sensor  24  before the ultrasonic signals arrive at the ultrasonic sensors  20  and  22  because, of course, light travels faster than sound. The infrared signal, in addition to indicating to the capture bar  12  which stylus is in contact with the writing surface  14 , also activates the ultrasonic sensors  20  and  22 . The capture bar  12  uses the known time at which the stylus  16  transmitted the ultrasonic signals (i.e., the time at which the infrared sensor  24  received the infrared signal) and the time at which each of the ultrasonic sensors  20  and  22  received the ultrasonic signal to calculate the distance between the stylus  16  and the ultrasonic sensors  20  and  22 . The capture bar  12  employs a computer processor (not shown) to calculate the location of the stylus  16  using basic trigonometric formulas. That is, knowing that the stylus  16  is a distance A from the ultrasonic sensor  20  and a distance B from the ultrasonic sensor  22 , and knowing that a distance, D 1 , separates the ultrasonic sensors  20  and  22 , the capture bar  12  can calculate the angles of the resulting triangle and, by doing so, the precise location of the stylus  16  on the writing surface  14 . 
         [0015]    In some instances, the digitizing system  10  may be employed as an interface between a user and a computer (e.g., for controlling the computer or inputting information into the computer).  FIG. 2  illustrates one such embodiment. In  FIG. 2 , a capture bar  26  is mounted on a surface  28 , depicted as a projector screen or whiteboard onto which a projector  30  projects an image  32 . The image  32  corresponds to an image  34  generated by a computer  36 . The image  34  is transmitted to the projector  30  and may, additionally, be displayed on a display  35  associated with the computer  36 . A connection  38  (e.g., a USB 1.0 connection, USB 2.0 connection, USB 3.0 connection, an IEEE-1394 connection, or any other suitable communication connection) may communicatively couple the capture bar  26  to the computer  36 , and a connection  40  (e.g., a DVI connection, an S-video connection, a VGA or SVGA connection, or any other suitable communication connection) may communicatively couple the computer  36  to the projector  30 . While each of the connections  38  and  40  is depicted as a wired connection, either or both of the connections  38  and  40  may, alternatively, be wireless connections. For example, a wireless connection, such as a wireless USB connection or a Bluetooth® connection, may implement the connection  38 . Similarly, a protocol capable of transmitting video wirelessly (e.g., Wireless Home Digital Interface) may implement the connection  40 . Of course, for a wireless connection, respective transceivers (not shown) would attach to (or be integrated with) the capture bar  26  and the computer  36  and/or the projector  30 . 
         [0016]    Moreover, in some embodiments, the connection  38  may include multiple connection segments. For example, and with reference to  FIGS. 3A-3D , the capture bar  26  may include a connection bar  25  coupling the capture bar  26  to the charging tray  18  ( FIGS. 3A ,  3 B). The connection bar  25  also ensures a correct relative positioning of the capture bar  26  and the charging tray  18 . A wired (or wireless) connection may communicatively couple the charging tray  18  to the computer  36 . In some embodiments in which the connection  38  is wireless ( FIGS. 3B ,  3 D), a transceiver dongle  27  may be connected directly to the capture bar  26  to provide wireless communication with a similar transceiver  27  attached to, or incorporated within, the computer  36 . By way of example, the transceiver dongle  27  may connect to the capture bar  26  via a USB connector  29  to establish the connection  38  with the computer  36 . In some embodiments that include the charging tray  18 , the connection bar  25  may be communicatively coupled to the capture bar  26  via the USB connector  29 , and may be communicatively coupled to the charging tray  15  via a USB connector  31 . A wired or wireless connection may, in turn, communicatively couple the charging tray  18  to the computer  36 . In this manner, a user may easily choose to implement wired communication ( FIGS. 3A ,  3 C) or wireless communication ( FIGS. 3B ,  3 D) for the connection  38 , and may also easily choose to include the charging tray  18  ( FIGS. 3A ,  3 B) or not include the charging tray  18  ( FIGS. 3C ,  3 D) in the system. 
         [0017]      FIG. 4  depicts a block diagram of an embodiment of the system illustrated in  FIG. 2 . As described above, the capture bar  26  may include one or more receivers  42 ,  44 ,  46  for receiving signals from the stylus  16 . In the depicted embodiment, the receivers  42 ,  44 ,  46  include two ultrasonic receivers  42 ,  44  and an infrared receiver  46 . Each of the receivers  42 ,  44 ,  46  may be communicatively coupled to a processor  48 . The processor  48  may receive data from each of the receivers  42 ,  44 ,  46  and may use the received data to calculate a current location of the stylus  16 , determine an action associated with the stylus  16  (e.g., a button press), determine that a user is using the stylus, etc. The processor  48  may be communicatively coupled to (or integrated with) a memory  50  for storing instructions for executing various features and/or functions of the capture bar, information related to the data received from the receivers  42 ,  44 ,  46 , including results of calculations in which the data are used, etc. 
         [0018]    Additionally, the processor  48  may be communicatively coupled to an IR transmitter  52 . The processor  48  may cause the IR transmitter  52  to transmit signals or codes, which signals or codes may cause a projector (such as the projector  30 ) or a display (not shown) to power on, to power off, to change modes, etc., in accordance with various conditions. For example, the processor  48  may cause the IR transmitter  52  to transmit a “power on” code when the processor  48  detects (e.g., via the IR receiver  46 ) that a user is using the stylus  16 , or to transmit a “power off,” “sleep,” or “standby” code when the processor  48  detects a predetermined period of inactivity. Such pre-determined period of inactivity may, for example, be programmed by a user. As another example, the processor  48  may cause the IR transmitter  52  to transmit a “power on” code (or a “toggle power” code, a “toggle standby” code, or any other code) in accordance with a user command received from the computer  36  or from a button (not shown) on the capture bar  26 . Of course, the capture bar  26  may implement appropriate hardware configuration and/or software algorithms to prevent the IR receiver  46  from detecting and/or responding to the signal output by the IR transmitter  52 . 
         [0019]    The processor  48  may also be communicatively connected to an interface  54  for connecting the capture bar to the computer  36  (i.e., via the connection  38 ). As described above, the connection  38  may be any appropriate connection known in the art including, by way of example and not limitation, a USB connection, a wireless USB connection, a Bluetooth® connection, etc. Accordingly, the interface  54  may include any appropriate hardware (or combination of hardware) for implementing the connection  38 , and the memory  50  may include any appropriate instructions for implementing the connection  38  between the capture bar  26  and the computer  36 . 
         [0020]    The computer  36  may be any personal computer or workstation, as generally known in the art. While depicted in  FIG. 2  as a laptop computer, the computer  36  may be a laptop computer, a desktop computer, a “netbook” computer, a workstation, a server, a hand-held computer such as a personal digital assistant or a smart phone, etc. The connection  38  communicatively connects the capture bar  26  to the computer  36  through the interface  54  and an interface  56 , respectively. Like the interface  54 , the interface  56  may include any appropriate hardware (or combination of hardware) for implementing the connection  38 . 
         [0021]    The interface  56  may be communicatively coupled to a processor  58  in the computer which may, in turn, be communicatively coupled to a memory  60 , a video interface  62 , and a peripheral interface  64 . As a person of ordinary skill in the art would readily appreciate, the memory  60  may include one or more volatile memory devices, one or more non-volatile memory devices, and/or a combination of volatile and non-volatile memory devices. The memory  60  stores computer-readable instructions and/or data executed by the processor  58  as one or more programs or applications including, by way of example and not limitation, an operating system, device drivers, word processors, Internet browsers, etc. The memory  60  may also store computer-readable instructions and/or data for operating and/or using the digitizing system  10 . For example, the memory  60  may include computer-readable instructions allowing the processor  58 , in some embodiments, to control the IR transmitter  52  directly, or to upload to the memory  50  codes for the IR transmitter  52 . 
         [0022]    The video interface  62  may include hardware and/or software for receiving information from the processor  58  and rendering and outputting a display signal. The display signal may be output to the display  35 , which may include an integrated display (such as in a laptop computer) or an external display (as commonly found on desktop computers). The video interface  62  may include a second output for establishing the connection  40  to the projector  30  or display screen. Alternatively, the video interface  62  may forego outputting the display signal to the display  35  of the computer  36 . 
         [0023]    In any event, the connection  40  communicatively couples the computer  36  to the projector  30  via the video interface  62  in the computer  36  and a video interface  66  in the projector  30 . The video interface  66  may include hardware and/or software for receiving a signal from the video interface  62 . Additionally, the video interface  66  may include hardware and/or software for communicating with a processor  68  in the projector  30  and for rendering and outputting an image to projector optics  70  (e.g., lenses, focusing rings, display elements, etc.). The processor  68 , in addition to being communicatively coupled to the video interface  66 , may be communicatively coupled to one or more of a memory  72 , a user interface  74 , and an IR receiver  76 . The memory  72  may include one or more volatile memory devices, one or more non-volatile memory devices, and/or a combination of volatile and non-volatile memory devices. The memory  72  may store computer-readable instructions and/or data executed by the processor  68  to implement the projection and/or control functions of the projector  30 . 
         [0024]    The user interface  74  of the projector  30  may include any buttons and/or switches used to control the functionality of the projector  30 . The IR receiver  76  may be integrated as part of the user interface  74 , or may be a separate component connected directly to the processor  68 . In any event, the IR receiver  76  and the processor  68  cooperate to allow a user to perform (or cause the projector  30  to perform) certain functions (e.g., powering on, powering off, entering standby mode, changing resolution, etc.). In particular, if an IR signal detected by the IR receiver  76  corresponds to a control code associated with a command or function of the projector  30 , the processor  68  will cause the projector  30  to execute the command or function. Additionally, one or both of the user interface  74  and the processor  68  may be coupled, for example through the connection  40 , to the personal computer  36 , which may allow certain functions and/or features of the projector  30  to be controlled directly from the computer  36 . For example, in one embodiment, the processor  58  may send a command through the connection  40  to cause the projector  30  to power on. As another example, a change in the video signal that indicates a change in the displayed image  32  (see  FIG. 2 ) may cause the projector  30  to “wake” if the projector  30  was in a “sleep” or a power-saving standby mode. 
         [0025]    Typically, each manufacturer (i.e, each make) of audio-visual devices such as televisions, recorders, receivers, etc. has a code or set of codes, implemented by the devices produced, for controlling the device via the IR receiver. Different models and or types of devices may implement different codes of the set of codes (e.g., a projector and a television may implement different codes though manufactured by the same company). Accordingly, in order that the capture bar  26  may perform certain control functions of the projector  30  by transmitting a signal from the IR transmitter  52 , the processor  48  in the capture bar  26  (or the processor  58  in the computer  36 ) must be programmed to use the codes for the particular make and model projector  30 . The digitizing system  10  may determine which codes to use for the particular make and model projector  30  in various ways. In some embodiments, a user inputs, via a software user interface or control panel operating on the computer  36 , the make (i.e., the manufacturer) and model of the projector  30  and, accordingly which set of codes should be transmitted from the IR transmitter  52  to perform various functions. Alternatively, or in addition, computer  36  (or the processor  48 ) may execute an automatic setup routine to determine the set of codes that should be transmitted from the IR transmitter  52  to perform various functions. For example, the computer  36  may, via the connection  40 , automatically determine the make and model of the projector  30 . In some embodiments, the set of IR transmitter codes corresponding to the make and model of the projector  30  (or a subset of the set of codes) is stored on the memory  50  of the capture bar  26 . In some embodiments, the codes may be requested by and/or transmitted to the capture bar from the computer  36  each time a signal is transmitted from the IR transmitter  52 . 
         [0026]    The IR transmitter  52  may or may not be visible to the user.  FIG. 5  depicts a cross-sectional view of a capture bar  26  in accordance with the present description, taken along the line A-A in  FIG. 1B . The capture bar  26  includes a body  80 , a faceplate  82 , and a component area  84  between the body  80  and the faceplate  82 . Mounting hardware  86  and/or supports  87  may secure within the component area  84  a printed circuit board (PCB)  88  having electrically connected thereto various components (e.g., the processor  48 , the memory  50 , the receivers  42 ,  44 ,  46 , the interface  54 , etc.). The IR transmitter  52  may be mounted on a planar surface  90  of the PCB  88  that is proximate to the faceplate  82 , such that the radiation emitted from the IR transmitter  52  radiates in a direction generally orthogonal to the planar surface  90  of the PCB  88 . The faceplate  82  may have a window  92  disposed within the faceplate so as to permit the radiation emitted from the IR transmitter  52  to pass through faceplate  82  relatively unobstructed. The window  92  may be a separate piece of material, different from the material from which the faceplate  82  is formed, or the window  92  may be a portion of the faceplate  82  having a lesser thickness than the remainder of the faceplate  82 . In any event, the window  92  and the IR transmitter  52  should each be positioned to align with the other. In some embodiments, multiple IR transmitters  52  may be included to radiate in different directions, thereby accommodating various positions of the capture bar  26  relative to the projector  30 . 
         [0027]    Moreover, in some embodiments, the capture bar  26  may include one or more radio-frequency (RF) transmitters (not shown) instead of, or in addition to, the IR transmitter  52 . The RF transmitters may operate in a manner similar to the IR transmitter  52 , in that the RF transmitters may operate to control one or more remote devices, such as the projector  30 , when such devices have an RF remote control interface instead of, or in addition to, an IR remote control interface. In some embodiments, an RF device in the capture bar  26 , used to establish the connection  38 , may also serve to transmit signals for remotely controlling the projector  30 . As just one example, the digitizing system  10  may employ a Bluetooth® transceiver (not shown) in the capture bar  26  to communicate with the computer  36  (i.e., to establish the connection  38 ). In such an embodiment, the Bluetooth® transceiver may also be capable of communicating with a Bluetoote-enabled projector  30  to perform remote control of the projector  30 . 
         [0028]    Further, while the present disclosure describes the digitizer system as digitizing the movement of the stylus  16  through use of the capture bar  26 , the use of a capture bar, per se, is not a necessary aspect of the presently described system. That is, the described system may be implemented in any digitizing system for use with a whiteboard, a projected display, etc., in which an auxiliary display device is used with the digitizing system. For example, a device having a digitizing module that connects through a computer interface to a computer may have, within the digitizing module or the computer interface, a remote control transmitter for controlling a display device. The digitizing module may include, by way of example and not limitation, the capture bar described above, one or more bezel-mounted sensors, a touch-sensitive surface, one or more imaging devices, etc., or any other means for detecting a user input on a display surface. Likewise, the display device may include, by way of example and not limitation, a flat-panel display (e.g., a liquid crystal display, a plasma display, an organic light emitting diode display, a light emitting diode display, an electroluminescent display, a surface-conduction electron-emitter display, a field emission display, etc.) or a projector (e.g., a cathode ray tube projector, a liquid crystal display projector, digital light processing detector, etc.) projecting an image onto a surface such as a whiteboard or a projection screen. In some embodiments, the digitizing system may not include a stylus, or may include a stylus that does not include a transmitter, such as when the digitizing system uses reflections from the stylus, a touch sensitive surface, etc., to determine the position of the stylus or other input device (e.g., a finger). 
         [0029]    While the present disclosure describes specific embodiments intended to be illustrative only, and not limiting, it will be apparent to those of ordinary skill in the art that changes, additions, or deletions may be made to the disclosed embodiments without departing from the spirit and scope of the disclosure. Moreover, it is explicitly contemplated that each of the individual features described with reference to the various embodiments disclosed may be combined with any of the other features disclosed herein. Thus, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the disclosure as defined by the appended claims.