Abstract:
A signaling pen of improved construction includes an actuator that functions generally independent of a bias and stop arrangement. Preferably an antenna is fixed to a PCB board secured within a body. This provides an efficient signal communication path. Preferably the PCB board is secured within an inner casing that also houses the ON/OFF actuator. An extension of the displaceable pen tip extends into said casing and controls the ON/OFF actuator.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a digital pen for use in association with a digitizing surface.  
       BACKGROUND OF THE INVENTION  
       [0002]     An electronic signaling device in the form of a pen or stylus has been used for many years in association with a digitizing surface. Basically, the stylus cooperates with the digitizing surface to determine the particular pattern of movement of the pen as it moves across the surface and provides a digital record thereof. These types of devices are used for a host of applications but have particular application in association with check writing and/or digital signatures.  
         [0003]     The technology for using a digital pen is quite well known and requires a user to place the pen on the appropriate surface and displaces a tip portion to activate the device as part of the normal writing process. The pen transmits or receives a signal depending on the particular application and in any event, the particular position of the pen on the surface is determined. As the pen is moved across the surface, the particular pattern is recorded and typically visually reproduced on the device.  
         [0004]     Although digital pens have been known for many years, the construction of the pens is complicated and the assembly of the components of the pen requires considerable precision and time.  
         [0005]     The present invention provides a simplified electronic pen which is cost effective to manufacture.  
       SUMMARY OF THE INVENTION  
       [0006]     An electronic signaling pen according to the present invention comprises an antenna and a pen tip movable relative to a casing which secures a printed circuit board (PCB). The pen tip is movable between an OFF position and an ON position with a spring bias urging the pen tip to the OFF position. The pen tip includes an actuator independent of the antenna that cooperates with a contact point of a circuit of the PCB board and changes the state of the circuit dependent upon the position of the pen tip in the ON or OFF position. The pen tip includes a stop arrangement that limits the extent that the tip moves towards the casing.  
         [0007]     According to an aspect of the invention, the PCB board includes an antenna fixed to the PCB board.  
         [0008]     According to a further aspect of the invention the pen tip moves relative to the antenna as the pen tip moves between the OFF position and the ON position.  
         [0009]     In yet a further aspect of the invention, the movement of the pen tip between the ON and OFF positions is less than 1 mm.  
         [0010]     In yet a further aspect of the invention, the actuator includes compressible material secured on an end portion of the pen tip.  
         [0011]     In yet a further aspect of the invention, the compressible material includes an electrical conducting portion at a free end thereof that engages and completes an electrical condition with the PCB board when the pen tip is in the ON position.  
         [0012]     In a different aspect of the invention, the pen includes an outer protective sleeve about the casing of the pen and the pin tip is movable relative to the outer protective sleeve.  
         [0013]     In yet a different aspect of the invention, the signaling pen has a split plastic molded casing about the circuit board and secures the circuit board. This plastic mold casing is plated with an electrically conducted material and includes a ground arrangement for grounding of the PCB board.  
         [0014]     In yet a different aspect of the invention, the casing adjacent the pen tip includes a port extending through the casing and the pen tip includes an extension member connected to the pen tip and extending into the casing. The extension member includes a compressible switch actuator engaging the PCB board when the pen tip is in the ON position.  
         [0015]     An electronic pen according to the present invention comprises a pen body, an electronic circuit secured in the body with the electronic circuit including a stationary part of an ON/OFF actuator. A movable pen tip is secured at one end of the body and is spring biased to an extended position relative to the pen body. The pen tip is movable to an actuating position partially telescoped within the pen body. The pen body includes a moving part of the ON/OFF actuator. This moving part includes an electrical conducting member that forms an electrical connection with the stationary part turning the actuator ON when the pen tip is in the actuating position. The moving part breaks any electrical connection with the stationary part as the pen tip moves from the actuating position to the extended position. The electronic circuit includes antenna preferably having a fixed connection with the electronic circuit.  
         [0016]     According to an aspect of the invention, the moving part of the actuator is a compressible member fixed on the pen tip interior to the pen body.  
         [0017]     In a different aspect of the invention, the pen tip cooperates with a structural element of the pen body to provide a stop surface defining the actuating position.  
         [0018]     In a different aspect of the invention, the pen includes a stop surface separate from said ON/OFF actuator that defines said actuating position. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]     Preferred embodiments of the invention are shown in the drawings, wherein:  
         [0020]      FIG. 1  is a partial perspective cutaway view of the electronic pen;  
         [0021]      FIG. 2  is a sectional view through the electronic pen;  
         [0022]      FIG. 3  is a partial sectional view showing the cooperation of the movable pen tip and pen body;  
         [0023]      FIG. 4  is a sectional view similar to  FIG. 2  but with the pen tip in an actuating position;  
         [0024]      FIG. 5  is a partial sectional view showing the pen tip in the actuating position;  
         [0025]      FIG. 6  is an exploded view showing the various components of the electronic pen;  
         [0026]      FIG. 7  is a partial perspective view of pen tip and pen body; and  
         [0027]      FIG. 8  is a partial perspective view of the pen casings. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0028]     The electrical pen  2  includes an outer pen body  4  housing an inner casing  6 . The inner casing is positioned within the outer pen body by guides and houses the PCB circuit board  8 . The displaceable tip  10  telescopes within the outer pen body  4  and moves between an extended position as shown in  FIGS. 1 and 3  to an actuating position or ON position as shown in  FIGS. 4 and 5 .  
         [0029]     The displaceable tip  10  protects the fixed antenna  12 . Preferably the antenna is a wire soldered on the PCB circuit board  8 . This provides an effective electrical connection of the antenna  12  to the PCB board. Other electrical connections of the antenna to the PCB board are possible, however, it is preferred that the antenna be fixed on the board to provide an effective signal path. There is no movement of the antenna relative to the PCB board during movement of the displaceable tip  10  from the extended position to the actuating position. In a preferred embodiment the wire antenna is a conventional wire. For example, 24 awg wire performs well.  
         [0030]     The displaceable tip  10  is preferably an injection molded plastic member and carries a movable part  20  of the ON/OFF actuator  16 . The PCB board  8  includes a stationary part defined by two spaced conductors  18  which cooperate with the electrical conducting surface  22  of the movable part  20 . As the pen tip moves from the extended position of  FIG. 1  to the actuating position of  FIGS. 4 and 5 , the movable part  20  which is a compressible member moves with the pen tip and applies a low pressure force on the two spaced conductors  18  due to compression of the movable member. The resilient compression of member  20  provides an efficient connection of the electrical conducting surface  22  with the electrical conductors  18  of the ON/OFF actuator  16 .  
         [0031]     With the present design, the movable part  20  undergoes compression and thus a pressure force is exerted to provide an effective connection of the two electrical connectors  18  of the stationary part of the actuator  16 . Compressible member  20  does not significantly act to stop the movement of the displaceable tip  10 . This movement is stopped due to an interference contact between the displaceable tip  10  and in this case, the end of the inner casing  6 . The bias spring  30  produces a force much greater (at least an order of magnitude greater) than the compression force generated by member  30 . Thus the resilient compression force of member  30  does not significantly influence the bias force of the spring.  
         [0032]     As shown in  FIG. 5 , extension  52  of the pen tip bottoms against the end  54  of the casing  8 . The bias spring  30  provides some resistance, however, it is the engagement of extension  52  and  54  of the casing that provides the positive stop and determines the actuating position of the pen tip. When pressure on the pen tip is removed, i.e. the pen tip is not in writing contact with a surface, the bias spring  30  forces the displaceable pen tip  10  to the extended position as shown in  FIGS. 1, 2  and  3 .  
         [0033]     As shown in the partial sectional view of  FIG. 3 , electrical conducting surface  22  of the movable part  20  is now spaced from the electrical conductors  18  of the stationary part of the ON/OFF actuator  16 .  
         [0034]     The inner casing  6  includes a first casing  66  and a second casing  68  and these casings include a port  60  through which the projecting arm  62  of the pen tip  10  extends. With this arrangement, the movable part  20  is located within the casing  6  and is quickly actuated by means of the movement of the pen tip to the actuating position. It can also be appreciated that the antenna  12  is stationary and includes an excellent electrical connection with the PCB board  8 .  
         [0035]     As shown in  FIG. 6 , the first casing  66  includes a guide tube  70  which is sized to receive the antenna  12 . The antenna is secured on the PCB board  8  and is then located together with the PCB board between the two casings. The first casing  66  and the second casing  68  cooperate to positively secure the PCB board  8  in a fixed position within the casing. Each of the casings  66  and  68  are a plastic molded component that is electrically plated with a conductive metal. The PCB extends across the two casings such that the split lines are above and below the PCB board. The metal plated casings act as a shield electrically protecting the PCB board from extraneous signals. Only the portion of the antenna beyond the casing is outside the shield whereby improved performance is achieved.  
         [0036]     The casings cooperate, as shown in  FIGS. 2 and 4 , where the grounding flanges  78  and  80  of the casings engage appropriate electrical contact portions  9  on the PCB board  8 . This provides a common voltage reference to the PCB board and the assembled casing. A ground sleeve  74  is then applied over the metal plating of the casings (see  FIG. 8 ).  
         [0037]     The PCB board  8  and the casings are assembled in a simple manner and the displaceable tip  12  is also assembled on the casings. This is required as the movable compressible part  20  is located within the casing. Therefore, the displaceable tip  10 , the spring  30  and the movable part  20  are assembled on the cooperating first and second casings  66  and  68 . Once this arrangement has been assembled, it can then be inserted into the open end  90  of the outer body pen portion  4 . The inner casing  6  is moved to the bottom end of the outer pen body  4  until it engages a stop or locating flange such as flange  32 . The spring relief provided by the rubber portion of the electrical conductor  100  closes the end of the pen body and locks the casing  6  in position.  
         [0038]     The general assembly of the pen is as follows: The electrical power conductor  100  and the antenna  12  are soldered to the PCB board. The PCB board is then positioned in the casing  66  and the antenna is placed in the tube  70  (see  FIG. 7 ). A bare portion of the antenna extends beyond the casing. The pen tip and actuator are assembled on the casing  66 . The other casing  68  is then assembled to enclose the PCB board. The assembled unit is inserted into the pen body and locks therewith.  
         [0039]     The metal plate casing and PCB board are grounded when the pen is actuated and a sinusoidal signal is provided to the casing when the pen is not actuated.  
         [0040]     This particular arrangement has proven to be effective partially due to the effective electrical connection of the antenna to the PCB board as well as the action of ON/OFF actuator  16  that operates essentially independently of a stop mechanism. The number of moving parts has been reduced and the ability to provide high quality control is realized. The ON/OFF actuator and the pen tip operate quickly without any large movement of the displaceable pen tip. This improves the feel of the pen to a user.  
         [0041]     Although various preferred embodiments of the present invention have been described herein in detail, it will be appreciated by those skilled in the art that variations may be made thereto without departing from the spirit of the invention or the scope of the appended claims.