Patent Publication Number: US-8118071-B2

Title: Pencil sharpener

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims benefit of and priority to U.S. patent application Ser. No. 12/360,368, filed on Jan. 27, 2009, entitled “Pencil Sharpener”, invented by Charles Sued and Aron Abramson, and is hereby incorporated by reference herein as if set forth in its entirety. 
     BACKGROUND 
     The present invention is generally directed to pencil sharpeners and, more specifically, to an automated pencil sharpener. 
     Conventional pencil sharpeners are difficult to operate and require monitoring and/or manipulation by a user. It would be advantageous to provide a pencil sharpener that simplifies and/or facilitates the sharpening of pencils. 
     SUMMARY 
     Briefly speaking, one embodiment of the present invention is directed to an automatic pencil sharpener including a housing defining a bore configured to receive a pencil therein. A selectable control is configured to allow selection of a degree of sharpness to which the pencil will be sharpened. A cutting mechanism is disposed in the housing and is adapted to sharpen the pencil in the bore. The cutting mechanism is configured to sharpen the pencil to any one of a plurality of degrees of sharpness depending on the selectable control. Wherein the cutting mechanism is configured to secure the pencil inserted in the bore, automatically advance the pencil during the sharpening thereof, and then to at least partially eject the pencil after sharpening. The automatic pencil sharpener is adapted for a pencil to be placed in the bore to be automatically sharpened and at least partially ejected without manual manipulation of the pencil during sharpening and at least partial ejection. 
     In a separate aspect, one embodiment of the present invention is an automatic pencil sharpener including a housing defining a bore configured to receive a pencil therein. A cutting mechanism is disposed in the housing and is adapted to sharpen the pencil in the bore. The cutting mechanism is configured to secure the pencil inserted in the bore, automatically advance the pencil during the sharpening thereof, and then to at least partially eject the pencil after sharpening. A sensor is positioned proximate the bore to detect a portion of a person&#39;s body. A controller is in communication with the sensor and the cutting mechanism. When the sensor determines a portion of a person&#39;s body is touching a portion of the housing proximate to the bore, the controller stops the cutting mechanism to prevent injury. The automatic pencil sharpener is adapted for a pencil to be placed in the bore to be automatically sharpened and at least partially ejected without manual manipulation thereof. 
     In a separate aspect, one embodiment of the present invention is directed to a method of automatically sharpening a pencil. The method includes: providing a housing defining a bore adapted to receive the pencil for automatic sharpening; selecting a degree of sharpness to which to sharpen the pencil; inserting the pencil into the bore; automatically advancing the pencil without requiring manual manipulation to sharpen the pencil; automatically sharpening the pencil to one of a plurality of degrees of sharpness; and automatically at least partially ejecting the pencil after the completion of the sharpening operation. 
     In another aspect, one embodiment of the present invention is directed to a method of automatically sharpening a pencil. The method including: providing a housing defining a bore adapted to receive the pencil for automatic sharpening; automatically monitoring the housing proximate the bore to detect a portion of a person&#39;s body and stopping the sharpening operation to prevent injury if the portion of the person&#39;s body is detected. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following detailed description of the preferred embodiments of the present invention will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings embodiments which are presently preferred. It is understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings: 
         FIG. 1  is a front elevational view of a pencil sharpener according to a preferred embodiment of the present invention; The pencil sharpener preferably includes an LCD screen with a status indicator that may indicate “READY” when the pencil sharpener is ready to operate; The pencil sharpener can include any one or combination of time, date, and temperature indicators; The pencil sharpener preferably includes a pencil shavings bin gauge that illustrates how close to full is the bin; A countdown timer may also be included that alerts a user as to how much time remains for a pencil sharpening operation to be completed; The pencil sharpener preferably includes selectable sharpness controls to allow a user to select whether pencils should be sharpened to a regular, sharp, or very sharp point; Similarly, the sharpener may include selectable variable sharpness controls that allow the amount of sharpness to be varied in small increments; The sharpener may use a power conduit, be powered by batteries, or use any suitable power source; The pencil sharpener preferably automatically secures a pencil during the sharpening process to prevent a user from having to push the pencil inwardly during sharpening; A light may be located around the bore into which the pencil is loaded; This automates the process and allows a user to simply load the pencil and then attend to other matters; 
         FIG. 2  is a front elevational view of a second preferred embodiment of the pencil sharpener according to the present invention; The sharpener may include a touch sensitive sensor that surrounds the bore to determine when a user&#39;s finger is too close to the bore; The touch sensitive sensor preferably deactivates the pencil sharpener cutting operation when it detects a portion of a person&#39;s body; The pencil sharpener preferably includes an LCD screen with a status indicator that may indicate “READY” when the pencil sharpener is ready to operate and which may include an identification of the current sharpness setting (in this case the sharpener is shown to be set for medium sharpness as shown by the icon to the right of the READY icon); The pencil sharpener can include any one or combination of time, date, and temperature indicators; The pencil sharpener preferably includes a pencil shavings bin gauge that illustrates how close to full is the bin; A countdown timer may also be included that alerts a user as to how much time remains for a pencil sharpening operation to be completed; The pencil sharpener preferably includes selectable sharpness controls to allow a user to select whether pencils should be sharpened to a medium, sharp, or very sharp point; Similarly, the sharpener may include selectable variable sharpness controls that allow the amount of sharpness to be varied in small increments; The pencil sharpener preferably automatically secures a pencil during the sharpening process to prevent a user from having to push the pencil inwardly during sharpening; A light may be located around the bore into which the pencil is loaded; This automates the process and allows a user to simply load the pencil and then attend to other matters; 
         FIG. 3  is a side elevational view of the pencil sharpener of  FIG. 2  illustrating the pencil shavings bin in an extended position; The pencil shavings bin preferably slidably retracts from the rear of the sharpener housing; 
         FIG. 4  is a perspective view of one type of cutting mechanism that may be used with any embodiment of the pencil sharpener of the present invention; This cutting mechanism may use a single set of paired cutters to sharpen pencils to varying degrees as desired; Polymer wheels are preferably spring loaded to grasp a pencil once it is inserted into the sharpener; At least one of the wheels is driven by a wheel motor to adjust the pencil position; The pencil is guided to the paired cutters that sharpen the pencil; A cutting motor is linked to the paired cutters via gears; A sensor that uses multiple light beams may be used to monitor how far into the paired cutters the pencil has been driven which allows the level of sharpness to be controlled; Alternatively, the wheel motor may be a step motor that moves the pencil an incremental distance depending on the desired level of sharpness; and 
         FIG. 5  is a perspective view of another type of cutting mechanism that may be used with any embodiment of the pencil sharpener of the present invention; This cutting mechanism may use multiple sets of paired cutters to sharpen pencils to varying degrees as desired; Polymer wheels are preferably spring loaded to grasp a pencil once it is inserted into the sharpener; At least one of the wheels is driven by a wheel motor to adjust the pencil position; The paired cutters are preferably arranged in pairs on a carousel and configured to provide different degrees of sharpening; The carousel may be driven by a carousel motor; The pencil is guided to the paired cutters that are aligned therewith by the carousel; The cutting motor is linked to the paired cutters that will sharpen the pencil; Each of the paired cutters may be linked to a separate gear that is engaged with the cutter gear when the paired cutters are moved into position for use in a sharpening operation; A sensor (not shown) that uses multiple light beams may also be used to monitor how far into the paired cutters the pencil has been driven which allows the level of sharpness to be further modified; Similarly, the wheel motor may be a step motor that moves the pencil an incremental distance depending on the desired level of sharpness; 
         FIG. 6  is a cross-sectional view of a pencil sharpener similar to that illustrated in  FIGS. 1 and 2  that shows one preferred method of determining the amount of pencil shavings that have accumulated in the pencil shavings bin; The pencil may be held in position by polymer wheels and driven toward a set of paired cutters; The cutter motor drives the paired cutters to sharpen the pencil; During the sharpening process pencil shavings may fall into the bin; The pencil shavings bin may include a sensor that comprises a horizontal light curtain; As the amount of pencil shavings in the bin increases, light beams that are positioned below the level of accumulated pencil shavings in the bin are interrupted. This provides a mechanism for the pencil sharpener to determine what amount of the pencil shavings bin capacity has been used; 
         FIG. 7  is a front elevational view of a third preferred embodiment of the pencil sharpener according to the present invention; The sharpener may include a touch sensitive sensor that surrounds the bore to determine when a user&#39;s finger is too close to the bore; The touch sensor illustrated in this embodiment uses interspersed conductive layers; However, the pencil sharpener may use any suitable sensor without departing from the present invention; The touch sensitive sensor preferably deactivates the pencil sharpener cutting operation when it detects a portion of a person&#39;s body; A light may be located around the bore into which the pencil is loaded; This automates the process and allows a user to simply load the pencil and then attend to other matters; 
         FIG. 8  is a block diagram of the pencil sharpener of  FIG. 1 ; and 
         FIG. 9  is a circuit diagram of a preferred controller for a pencil sharpener. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Certain terminology is used in the following description for convenience only and is not limiting. The words “right,” “left,” “top,” and “bottom” designate directions in the drawings to which reference is made. The words “inwardly” and “outwardly” refer to directions toward and away from, respectively, the geometric center of the pencil sharpener and designated parts thereof. The term “control”, as used in the claims and the corresponding portions of the specification, means “any one of a physical switch, a touch switch, a button, a voice activated switch, a control knob, a remote control switch, or any other known operating mode selection device”. The term “activated state”, as used with selectable control, means that the selectable control has been manipulated so that the selectable control is set for a particular function. For example, if the selectable control is a simple switch, then the activated state may be having the switch turned to another position and if the selectable control is a touch sensor, then the activated state may be initiated by depressing or touching the sensor in a predetermined manner. The language “at least one of ‘A’, ‘B’, and ‘C’,” as used in the claims and in corresponding portions of the specification, means “any group having at least one ‘A’; or any group having at least one ‘B’; or any group having at least one ‘C’;—and does require that a group have at least one of each of ‘A’, ‘B’, and ‘C’.” Additionally, the words “a” and “one” are defined as including one or more of the referenced item unless specifically stated otherwise. The terminology includes the words above specifically mentioned, derivatives thereof, and words of similar import. 
     Referring to  FIGS. 1-9 , wherein like numerals indicate like elements throughout, there are shown preferred embodiments of a pencil sharpener  10 . Briefly speaking, the pencil sharpener  10  preferably allows a user to automatically sharpen a pencil  54  without holding or pushing the pencil  54  during the sharpening operation. The pencil sharpener  10  is preferably adapted for a pencil  54  placed in the bore  14  to be automatically sharpened and at least partially ejected without further manual manipulation of the pencil  54  during sharpening and at least partial ejection. The pencil sharpener  10  may be configured to allow a user to select the degree of sharpness to which the pencil  54  is sharpened. It is preferable that the sharpener  10  is configured to allow any one of at least two degrees of sharpness to be selected for the pencil  54  to be inserted into the bore  14 . The pencil sharpener  10  may include a pencil shavings bin full indicator/gauge  30  and/or may include a time remaining indicator  32  to indicate the remaining time until completion of a sharpening operation. The pencil sharpener  10  is preferably configured to automatically stop any sharpening operation if a portion of a person&#39;s body touches the sharpener  10  proximate the bore  14  that receives the pencil  54 . The pencil sharpener  10  can be configured to automatically secure the pencil  54  when it is inserted in the bore  14  so that the pencil  54  can be sharpened without a user having to hold or push the pencil  54 . It is also preferred that the pencil sharpener  10  automatically eject the pencil  54  at the completion of the pencil sharpening operation. Those of ordinary skill of the art will appreciate that the pencil sharpener  10  of the present invention may include any one or all of the above functions without departing from the scope of the present invention. 
     Referring to  FIG. 1 , one embodiment of the pencil sharpener  10  of the present invention includes a pencil sharpener housing  36 . The housing  36  preferably defines at least one bore  14  for receiving a pencil to be automatically sharpened. The front of the housing preferably has a generally semicircular upper portion and a generally rectilinear lower portion to form a generally upside down “U”. Referring to  FIGS. 1-3 , while preferred housings  36  have been shown, those of ordinary skill in the art will appreciate from this disclosure that the pencil sharpener housing  36  can have any shape without departing from the scope of the present invention. 
     The pencil sharpener  10  preferably receives power from an outlet via a power conduit, such as an electrical cord,  12 . However, the pencil sharpener can be powered by batteries or any other suitable power source. 
     Referring to  FIGS. 1 and 2 , the pencil sharpener  10  preferably includes a selectable control  22 , such as a power switch, that is in communication with the pencil sharpener  10  and has an activated state adapted to configure the pencil sharpener  10  to automatically grasp any pencil that is inserted into the bore  14  of the housing  36 . A light  16  may be located around the bore into which the pencil  54  is loaded. The light  14  can be configured to blink once a pencil  54  has been sharpened and is ready for removal or can change colors depending on the stage of the sharpening operation. The light  14  is preferably disposed proximate to the bore  14  to give a visual alert when the sharpening process is complete. The light  14  can be, but is not necessarily, adapted to change at least one colors and illumination intensity to indicate the status of the sharpening process. For example the light  14  may be blue while the sharpener  10  is waiting for the pencil  54  to be loaded; change to red during sharpening; and change to green once the pencil  54  has been sharpened and the sharpening operation has ceased. Any combination of colors or illumination patterns may be used to indicate the status of a pencil sharpening operation without departing from the scope of the present invention. Additionally, audible indicators including a recorded voice can be used to indicate the status of a cutting operation. 
     Referring to  FIG. 1 , the pencil sharpener preferably includes an display, such as a liquid crystal display (LCD) or any other suitable display. It is preferably that the display include a countdown timer therein that represents the time for the sharpening process to be completed. Alternatively, light emitting diodes can be used to transmit information without departing from the scope of the present invention. 
     The display preferably includes a status indicator  34  that may indicate “READY” when the pencil sharpener is ready to operate. A selected sharpness indicator  44  (shown in  FIG. 2 ) may also be displayed. The pencil sharpener  10  can include any one or combination of time, date, and temperature indicators,  26 ,  28 , and  24  respectively. Additional parameters, such as remaining battery life, barometric pressure, etc. may also be displayed without departing from the scope of the present invention. 
     The pencil sharpener preferably includes a pencil shavings bin gauge  30  that illustrates how close to full is the pencil shavings bin  48 . A sensor may be configured to determine when the pencil shavings bin is full and a display may indicate when the sensor detects a full pencil shavings bin. Referring to  FIG. 3 , the pencil shaving bin may be extendable from the rear  50  of the sharpener housing  36 . The pencil sharpener  10  may be configured to automatically extend the bin  48  and halt sharpening operations when the bin  48  is full or just to activate an alarm or warning signal. The alarm or warning signal can be any one or combination of an audible alarm and a visual alarm. Alternatively, the bin  48  may auto open and close due to selection of a control (not shown). A countdown timer  32  may also be included in the pencil sharpener  10  that alerts a user as to how much time remains for a pencil sharpening operation to be completed. Any of the countdown timers, gauges, icons, buttons, controls, etc. that are discussed in this application and which may be illustrated in the drawings in connection with the pencil sharpener  10  can be varied or reconfigured using any suitable display, configuration, alarm, indicator, or mechanism to convey the necessary information or receive the necessary input without departing from the scope of the present invention. 
     The pencil sharpener  10  preferably includes selectable sharpness controls  18 A,  18 B, and  18 C (also referred to as a “selectable control” or “selectable controls” in the claims) to allow a user to select whether pencils should be sharpened to a medium, sharp, or very sharp point. That is the selectable control  18 A,  18 B, and  18 C may be configured to allow selection of the degree of sharpness to which a pencil is sharpened. For example only, the control  18 A for a regular point may result in a pencil point having a central cross-sectional angle through the apex of approximately sixty degrees; the control  18 B for a sharp point may result in a pencil point having a central cross-sectional angle through the apex of approximately forty degrees; and the control  18 C for a very sharp point may result in a pencil point having a central cross-sectional angle through the apex of approximately thirty degrees. Similarly, the sharpener  10  may include selectable variable sharpness controls  20 A,  20 B, and  20 C that allow the amount of sharpness to be varied in increments. Those of ordinary skill in the art will appreciate from this disclosure that the degree of sharpness can be varied along with the possible incremental adjustment without departing from the scope of the present invention. 
     Referring to  FIGS. 4 and 5 , a cutting mechanism is disposed in the housing  36  and adapted to sharpen the pencil  54  in the bore  14 . The cutting mechanism is preferably configured to sharpen the pencil  54  to any one of a plurality of degrees of sharpness depending on the selectable control  18 A,  18 B,  18 C. The cutting mechanism is preferably configured to secure the pencil  54  inserted in the bore  14 , automatically advance the pencil  54  during the sharpening thereof, and then to at least partially eject the pencil  54  after sharpening. The cutting mechanism may include wheels  52  configured to secure the pencil  54  in the bore  14 . The wheels  52  are preferably configured to transport the pencil  54  during the sharpening process and during ejection from the automatic pencil sharpener  10 . 
     The pencil sharpener  10  preferably automatically secures a pencil  54  during the sharpening process to prevent a user from having to push the pencil  54  inwardly during sharpening. This automates the process and allows a user to simply load the pencil  54  and then attend to other matters. 
     Referring to  FIG. 2 , The sides of the sharpener housing  36  may flare generally outwardly when moving along the perimeter of the housing  36  generally upwardly away from the base  38  of the sharpener  10 . Then, the housing  36  goes through a gentle arc to form the upper contour of the sharpener  10 . 
     The sharpener  10  may include a touch sensitive sensor  40  that surrounds the bore  14  to determine when a user&#39;s finger is too close to the bore. The touch sensitive sensor preferably deactivates the pencil cutting operation when it detects a portion of a person&#39;s body. 
     Referring to  FIG. 3 , it is preferable that the side of the sharpener bends slightly inwardly to form a fold. The pencil shavings bin  48  may be able to extend from the rear  50  of the housing  36  to simplify the disposal of pencil shavings. 
     Referring to  FIG. 4 , one type of cutting mechanism that may be used with any embodiment of the pencil sharpener  10  of the present invention uses a single set of paired cutters  58  to sharpen pencils  54  to varying degrees of sharpness, as desired. It is preferable that wheels  52  are spring loaded to grasp a pencil  54  once it is inserted into the sharpener. The wheels may be formed of polymer or any suitable material. An electronic sensor may be used to determine when the pencil  54  is inserted into the bore  14 . Three wheels  52  may be used to ‘grasp’ the pencil  54 . At least one of the wheels  52  can be driven by a wheel motor  56  to adjust the pencil position. This allows the pencil  54  to be guided to the paired cutters  58  that for sharpening. While one structure has been described for securing a pencil  54  during a sharpening operation, those of ordinary skill in the art will appreciate from this disclosure that any suitable structure or method of securing the pencil  54  may be used without departing from the scope of the present invention. 
     Referring still to  FIG. 4 , a cutting motor  64  is preferably linked to the paired cutters  58  via gears  66 ,  62 , and  60 . The cutting motor  64  may be concentrically mounted with a cutting gear  66 . The cutting gear  66  drives intermediate gear  62  which drives cutter gears  60  on the paired cutters  58 . 
     A sensor  68  that uses multiple light beams  70  may be used to monitor how far into the paired cutters  58  the pencil  54  has been driven which allows the level of sharpness to be controlled. However, those of ordinary skill in the art will appreciate from this disclosure that any suitable type of sensor can be used without departing from the scope of the present invention. Alternatively, the wheel motor  56  may be a step motor that moves the pencil  54  an incremental distance depending on the desired level of sharpness. 
     The cutting mechanism may include a carousel  74  rotateably positioned within the housing  36  and supporting a plurality of paired cutters  72 A,  72 B,  72 C. Each of the plurality of paired cutters  72 A,  72 B,  72 C being configured to sharpen a pencil  54  to a different degree of sharpness. Referring to  FIG. 5 , another type of cutting mechanism that may be used with any embodiment of the pencil sharpener  10  of the present invention uses multiple sets of paired cutters  72 A,  72 B, and  72 C to sharpen pencils  54  to varying degrees as desired. The paired cutters  72 A,  72 B, and  72 C are preferably arranged in pairs on a carousel  74  and can each be configured to provide different degrees of sharpening. The carousel  74  may be driven by a carousel motor  76 . The carousel  74  may align one of the plurality of paired cutters  72 A,  72 B,  72 C with the bore  14  depending on the degree of sharpness selected via the selectable control(s)  18 A,  18 B,  18 C. 
     The wheels  52  can guide the pencil  54  to the paired cutters  72 A that are aligned under the wheels  52  by the carousel  74 . While the carousel is shown as having three paired cutters  72 A,  72 B, and  72 C, those of ordinary skill in the art will appreciate from this disclosure that any number of paired cutters can be used without departing from the scope of the present invention. For example, one, two, four or more paired cutters can be used by the cutter mechanism. 
     The cutting motor  64  may be linked to the paired cutters  72 A,  72 B, or  72 C that will sharpen the pencil via gears  66 ,  62 ,  60 . The cutting gear  66  drives the adjacent intermediate gear  62  which drives cutter gears  60  on the paired cutters  72 A,  72 B, or  72 C. A sensor (not shown) that uses multiple light beams may also be used to monitor how far into the paired cutters the pencil  54  has been driven which allows the level of sharpness to be further modified. Similarly, the wheel motor  56  may be a step motor that moves the pencil  54  an incremental distance depending on the desired level of sharpness. While preferred embodiments of the cutting mechanism have been described above, those of ordinary skill in the art will appreciate from this disclosure that any suitable cutting mechanism, linkage arrangement or the like can be used without departing from the scope of the present invention. As such, the present invention includes using a single rotary cutter rather than a cutter pair without departing from the scope of the present invention. 
     Referring to  FIG. 6 , a cross-sectional view of a pencil sharpener  10  according to the present invention is shown and illustrates one preferred method of determining the amount of pencil shavings that have accumulated in the pencil shavings bin  48 . As shown in the upper right portion of  FIG. 6 , the pencil  54  may be inserted inwardly into the pencil sharpener  10  and held in position by wheels  52 . The wheels  52  may drive the pencil generally leftwardly into the paired cutters  58  which sharpen the pencil  54 . The pencil shavings then fall generally downwardly from the pencil  54  and into the pencil shavings bin  48 . It is preferred that a senor  78  which comprises a horizontal light curtain positions a number of light beams  80  at different heights in the bin  48 . As the amount of pencil shavings in the bin  48  increase, light beams  80  that are at a lower height than the accumulated pencil shavings are interrupted. This provides a mechanism for the pencil sharpener  10  to determine what amount of the pencil shavings bin capacity has been used. While one preferred method of determining the fullness of the bin  48  has been disclosed, those of ordinary skill in the art will appreciate from this disclosure that any suitable method may be used without departing from the scope of the present invention. For example, the pencil sharpener may monitor weight to determine the amount of capacity remaining in the bin  48 . 
     Referring to  FIGS. 7-9 , touch detection circuitry  170  and sharpener control circuitry  160  is preferably disposed at least partially along and/or within the pencil sharpener housing  36 . When the sharpener detects an inserted pencil  54 , at least one of the touch detection circuitry and the sharpener control circuitry activates the cutting motor  64  to sharpen the pencil. It is preferred, that the cutters  58  rotate upon activation. However, vibratory movement, reciprocating movement, or any other suitable cutting movement can be used when the cutters  58  are activated. 
     Referring still to  FIGS. 7-9 , the sharpener  10  includes a first conductive layer  141  disposed on at least a portion of the outer surface  36  of the sharpener housing  36 . Referring to  FIGS. 7 and 8 , it is preferable that the first conductive layer  141  is disposed on at least a portion of the inner surface of the walls of the bore  14  or along a portion of the housing  36  proximate to the bore  14 . 
     As best shown in  FIG. 9 , the sharpener  10  may include a second conductive layer  143  disposed on at least a portion of the outer surface of the pencil sharpener housing. It is preferred, but not necessary, that the second conductive layer  143  is separated from the first conductive layer  141 . However, those of ordinary skill in the art will appreciate from this disclosure that the locations of the first and second conductive layers  141 ,  143  can be varied in location or area without departing from the scope of the present invention. 
     Referring specifically to  FIG. 7 , it is preferred that the first and second conductive layers  141 ,  143  are interspaced in a fingered format so that both the first and second conductive layers  141 ,  143  can be contacted by a single finger touching just one and/or both of the conductive layers or one area of the sharpener housing  36 . The sharpener  10  can also be configured to allow a user to selectively activate the fingers of the first and second conductive layers  141 ,  143  so that they can either be intermeshed in one area or located in separate areas. By selecting how to activate the conductive layers  141 ,  143 , a user can alter the sensitivity of the sharpener  10  and how quickly it will deactivate the cutters  58 . 
     The first and second conductive layers  141 ,  143  are preferably only as thick as necessary for reliable electrical communication. However, those of ordinary skill in the art will appreciate from this disclosure that the conductive layers  141 ,  143  can be of any thickness or can extend through the entire thickness of the sharpener housing  36  without departing from the scope of the present invention. 
     Referring to  FIG. 8 , while first and second controllers  142 ,  144  are described below, those of ordinary skill in the art will appreciate from this disclosure that a single controller be used to operate the sharpener  10  of the present invention without departing from the scope of the present invention. The first controller  144  is preferably formed by an integrated circuit or any other suitable control mechanism. The first controller  144  is preferably in communication with the sharpener  10  and is adapted to cause the cutters  58  to deactivate when certain conditions are met. 
     A second controller  142  is preferably in communication with at least one of the first and second conductive layers  141 ,  143 . When a portion of a person&#39;s body  136  touches both the first and second conductive layers  141 ,  143 , the second controller  142  is adapted to send a signal to the first controller  144 . The controller  142 ,  144  (a single controller may serve the function of the two controllers  142 ,  144 ) is preferably in communication with the cutting mechanism and is adapted to determine when a portion of a person&#39;s body is touching a portion of the housing  36  proximate the bore  14 . The controller  142 ,  144  preferably stops the cutting mechanism when a portion of a person&#39;s body is detected to prevent injury. When the first controller  144  receives the signal, the first controller  144  deactivates the cutters  58 . The second controller can preferably differentiate between the capacitance of a human and when a metallic and/or magnetic object contacts both of the first and second conductive layers  141 ,  143 . 
     Referring to  FIG. 9 , the illustrated schematic is exemplary only. Those of ordinary skill in the art will appreciate from this disclosure that any suitable circuit(s) can be used without departing from the scope of the present invention. In the preferred circuitry, when a portion of the person&#39;s body  136  is not in contact with both the interspaced first and second conductive layers  140 , the condition of the conductive layers  141 ,  143  is constant. During this time, the second controller&#39;s  142  second pin is activated in a high electric level (bigger then ⅔ Voltage Drain Drain). The second controller  142  sends a signal via the second controller&#39;s third pin  152  output to the first controller  144 . The signal can be a high, low, or a zero voltage signal as desired. The first controller  144  maintains the sharpener  10  in normal operating condition while receiving the appropriate signal from the second controller  142 . 
     During sharpener operations, when a portion of a person&#39;s body  136  touches both the conductive layers  141 ,  143 , the capacitance of the person&#39;s body  136  is connected with a high resistance resistor  146 . This results in an interference signal detected capacitor  148  and resistor  146 . Since, at the moment conductive layers  141 ,  143  are touched, the second pin of the second controller  142  has a high input resistance, human capacitance, resistor  146 , and resistor  154  are linked through the conductions layers  141 ,  143  and the person&#39;s body which divides the voltage. A touch-off voltage is then filtered by capacitor  148 . This results in a very low voltage level being provided to the second pin of the second controller  142 . This causes the second controller  142  to send a signal to the first controller  144  which causes the first controller  144  to shut down (i.e., stop the rotation of or otherwise deactivate) the cutters  58 . 
     The second controller  142  is preferably an integrated circuit that is in communication with the first conductive layer  141 . The second conductive layer  143  preferably has first and second electrical pathways  126 ,  128  each leading to a ground  130 . The first electrical pathway  126  includes a resistor  146  and the second electrical pathway  128  includes a capacitor  148 . It is understood that any suitable circuitry can be used with the sharpener of the present invention without departing from the scope of the present invention. 
     The first and second controllers  144 ,  142  are preferably configured to deactivate the cutters  58  until the portion of the person&#39;s body  136  stops contacting both the first and second conductive layers  141 ,  143 . The first controller  144  may activate a warning light  121  while the portion of the person&#39;s body  136  touches both of the first and second conductive layers  141 ,  143 . The warning light may include multiple light emitting diodes  162 ,  164  that each emit a different color light. It is preferred that the diodes  162 ,  164  combine to cause the warning light  121  to emit a generally yellow light when activated. The sharpener may also includes a speaker  157  electrically connected to the first controller  144 . The first controller  144  may activate the speaker  157  to emit a warning sound when the portion of the person&#39;s body  136  contacts the first and second conductive layers  141 ,  143 . When contact between a person&#39;s body  136  and the conductive layers  141 ,  143  is brief, then the sharpener  10  can be stopped for a brief period such as three seconds while an alarm and warning light are activated. The length of the pause in the sharpener  10  operation can be varied as desired. 
     It is preferable that if the portion of the person&#39;s body stays in contact with both the first and second conductive layers  141 ,  143  for a predetermined amount of time, that the first controller  144  is configured to turn off the sharpener. It is preferred that the predetermined amount of time is less than or equal to thirty seconds. It is more preferable still that the predetermined amount of time is less than or equal to 3 seconds. 
     The present invention also includes methods of automatically sharpening pencils. The steps of the method need not be performed in the recited order. The methods of the present invention preferably use the sharpener  10  described above. However, the methods of the present invention may operate with pencil sharpeners having fewer or different components from those described above. 
     One preferred method of automatically sharpening a pencil according to the present invention includes providing a housing  36  defining a bore  14  adapted to receive the pencil  54  for automatic sharpening. A degree of sharpness to which to sharpen the pencil may be selected. The method may include inserting the pencil  54  into the bore  14 . 
     The pencil may be automatically advanced without requiring manual manipulation to sharpen the pencil. The pencil may be automatically sharpening to one of a plurality of degrees of sharpness. The pencil can be automatically at least partially ejected after the completion of the sharpening operation. 
     The method of the present invention may include monitoring the housing  36  proximate to the bore for contact by a portion of a person&#39;s body  136  and deactivating the cutting mechanism to prevent injury if a portion of a person&#39;s body  136  is detected. The method may include indicating at least one of the status of the sharpening operation and the time remaining for completion of the sharpening operation. 
     A second preferred method of automatically sharpening a pencil according to the present invention may include providing a housing  36  defining a bore  14  adapted to receive the pencil  54  for automatic sharpening. The method may include automatically monitoring the housing  36  proximate the bore  14  to detect a portion of a person&#39;s body  136  and stopping the sharpening operation to prevent injury if the portion of the person&#39;s body  136  is detected. 
     The method may, but does not necessarily, include: inserting the pencil into the bore; automatically advancing the pencil without requiring manual manipulation to sharpen the pencil; automatically sharpening the pencil to one of a plurality of degrees of sharpness; and automatically at least partially ejecting the pencil after the completion of the sharpening operation. 
     Stopping the sharpening operation may include at least partially ejecting the pencil located in the bore to facilitate the portion of the person&#39;s body from being caught in the bore. 
     It is recognized by those skilled in the art that changes may be made to the above described pencil sharpener  10  without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but is intended cover all modifications which are within the spirit and scope of the invention as defined by the above specification, the appended claims and/or shown in the attached drawings.