Patent Publication Number: US-8531419-B2

Title: Information processing apparatus, operation input method, and sensing device

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 11/812,672 entitled “Information processing apparatus, operation input method, and sensing device”, filed Jun. 20, 2007, now U.S. Pat. No. 7,903,094, which is based upon application number P2006-174196 filed on Jun. 23, 2006 in Japan, the complete disclosures of each of which are incorporated herein by reference and to which priority is claimed. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to an information processing apparatus and an operation input method usable with a personal computer apparatus, and a sensing device for detecting an input operation of the information processing apparatus. More particularly, the present invention relates to an information processing apparatus, an operation input method, and a sensing device in which a personal computer apparatus can be operated by touching a display surface with a finger, a pen (e.g., stylus), or the like. 
     BACKGROUND OF THE INVENTION 
     Various operation input devices have been used with an information processing apparatus, such as a notebook-sized computer. For example, a keyboard having keys corresponding to the alphabet, numbers, and symbols has been used. Additionally, a touch panel which can be operated when a user touches the panel with a finger or the like has also been used with the information processing apparatus. 
     When a user touches the touch panel with a finger or the like, it is possible to change a display position of a pointer displayed on a screen of the information processing apparatus. A plurality of electrodes may be embedded in an operation surface of the touch panel and a touched position may be determined by detecting electrostatic capacity changes between the electrodes when the user touches the operation surface with the finger or the like. 
     Alternatively, an operation input device different from the touch panel may be used with the information processing apparatus. For example, an operation input device called a “pen tablet” may be used. In this case, a user touches an operation surface with a pen-shaped input device (stylus) designed for use with the pen tablet so that a user is able to perform an input operation which corresponds to the position touched with the stylus. 
     The pen tablet may be an electromagnetic induction type pen tablet in which a plurality of loop coils are embedded in an operation surface and a magnetic field is generated from the loop coils. The stylus which serves as a position pointing device includes coils that react with a magnetic field generated by the loop coils of the pen tablet. The electromagnetic induction type pen tablet is able to detect the position of the stylus based on an electromagnetic interaction generated between the magnetic field generated by the loop coils of the pen tablet and the stylus, when the stylus contacts or approaches the operation surface of the pen tablet. 
     Here, when the touch panel and the pen tablet are installed in a portable personal computer apparatus, considering the limited space and small size of the portable personal computer, respective position detecting mechanisms located under a common operation surface have been used to detect an input operation of both a finger of a user and a stylus. 
     Japanese Published Patent Application No. 9-1387730 describes a technology in which a detecting unit which serves as an electrostatic capacity type touch panel and a detecting unit which serves as an electromagnetic induction type pen tablet are disposed under a common operation surface. 
     However, when two operation input mechanisms (i.e., both detecting units) are located under the common operation surface, it becomes necessary to switch between the two operation input mechanisms. For example, when the display position of the pointer on the display screen of the personal computer apparatus is affected by these two operation input mechanisms, if it is detected that the electrostatic capacity type touch panel is also touched with the stylus when the personal computer apparatus is being operated by touching the operation surface with the stylus, then detected data from the two operation input mechanisms are both supplied to the personal computer apparatus. As a result, operation of the personal computer apparatus will be adversely affected. In particular, the pointer in the display screen may be moved erroneously. 
     For this reason, switch processing is used to select between the two operation input mechanisms. However, if the two operation input mechanisms are switched by using a manual switch, then operability will be reduced. Hence, the personal computer apparatus may include an automatic switching mechanism. 
     The Japanese Published Patent Application No. 9-1387730 describes switch processing in which, when the stylus approaches the operation surface within a certain distance, the electromagnetic induction type pen tablet is used with priority, and, in the meantime, the electrostatic capacity type touch panel is de-energized. However, this switch processing described in the Japanese Published Patent Application No. 9-1387730 describes is not able to switch the two operation input mechanisms satisfactorily. 
     More specifically, the switch processing described in the Japanese Published Patent Application No. 9-1387730 requires that a user should operate the stylus in constant contact with the operation surface. 
     However, some pen tablets can be operated in a state in which a tip of the stylus is not directly in contact with the operation surface, but instead the stylus and/or tip of the stylus is close or approaching the operation surface. 
     If the pen tablet can be operated by moving the tip of the stylus close to the operation surface, then a detection operation of the pen tablet to detect the approach of the tip of the stylus is used in both a switching operation and an input operation. Thus, when the pen tablet is operated with the stylus which is not in contact with the operation surface but is close to the operation surface, there is a possibility that the electromagnetic induction type pen tablet and the electrostatic capacity type touch panel will be switched unintentionally. This unintentional switching is problematic. 
     Also, when a display panel and the operation input device described above are formed as one body so that the personal computer apparatus may be operated by touching a display surface with a finger or stylus, operability of the personal computer apparatus can be improved. However, if the touch panel type operation input device described above and the pen tablet type operation input device described above are attached to the same display panel, then a problem arises in that switch processing to switch the above two operation input devices is required. 
     While a problem arising when the electrostatic capacity type touch panel and the electromagnetic induction type pen tablet are located at the same position has been described above, a similar problem also arises when two types of detecting units with other types of operation input mechanisms are disposed at the same place. Accordingly, there is a need for improved switch processing used to switch between input mechanisms. 
     SUMMARY OF THE INVENTION 
     The present invention provides an information processing apparatus, an operation input method, and a sensing device in which two types of operation detecting mechanisms can be switched and operated satisfactorily when the two types of operation detecting mechanisms are disposed near a display surface such that the information processing apparatus may be operated by touching the display surface. 
     An information processing apparatus includes an operation surface and a first sense unit for detecting whether the operation surface is directly touched. The information processing apparatus further includes a second sense unit for detecting whether a position pointing device approaches or contacts the operation surface based on an electromagnetic interaction generated between the second sense unit and the position pointing device. The information processing apparatus further includes an approach detecting unit for detecting whether the position pointing device is inside of a first detection range from the operation surface and whether the position pointing device is inside of a second detection range based on an output from the second sense unit. The first detection range extends further from the operation surface than the second detection range. The information processing apparatus further includes a display control unit for disabling display processing based on a detected output from the first sense unit and for enabling display processing based on a detected output from the second sense unit if the approach detecting unit determines that the position pointing device is inside of the second detection range. 
     An information processing apparatus is provided. The information processing apparatus includes a first sense unit for electrically detecting whether an operation surface is directly touched, a second sense unit for detecting whether a position pointing device approaches or contacts the operation surface based on an electromagnetic interaction generated between the second sense unit and the position pointing device, and an approach detecting unit for detecting whether the position pointing device is inside of a first detection range from the operation surface and whether the position pointing device is inside of a second detection range based on an output from the second sense unit. The first detection range extends further from the operation surface than the second detection range. The information processing apparatus further includes a display control unit for enabling display processing to be performed based on a detection output from the first sense unit if the approach detecting unit determines that the position pointing device is not inside of the first detection range, for disabling display processing based on the detection output from the first sense unit if it is determined that the position pointing device is inside of the first detection range from the operation surface, and for enabling display processing to be performed based on a detection output from the second sense unit if it is determined that the position pointing device lies within the second detection range. 
     An operation input method for accepting an input at an operation surface of an information processing apparatus is also provided. The method includes first detection processing for electrically detecting whether the operation surface is directly touched, second detection processing for detecting whether a position pointing device approaches or contacts the operation surface based on an electromagnetic interaction with the position pointing device, approach detection processing for detecting whether the position pointing device approaches within a first detection range from the operation surface and whether the position pointing device approaches within a second detection range based on an output from the second detection processing. Here, the first detection range extends further from the operation surface than the first detection range. The method further includes display control processing for disabling display processing based on a detection output from the first detection processing if the approach detection processing determines that the position pointing device approaches the second detection range, and enabling display processing based on a detection output from the second detection processing if the approach detection processing determines that the position pointing device approaches within the second detection range. 
     An operation input method for accepting an input at an operation surface of an information processing apparatus is also provided. The operation input method includes first detection processing for detecting whether the operation surface is directly touched, second detection processing for detecting whether a position pointing device approaches or contacts the operation surface based on an electromagnetic interaction with the position pointing device. The method further includes display control processing for enabling display processing based on a detected output of the first detection processing to be performed if the second detection processing determines that the position pointing device does not approach within a first detection range from the operation surface, for disabling display processing based on the detected output of the first detection processing if it is determined that the position pointing device approaches within the first detection range from the operation surface, and for enabling display processing based on a detected output of the second detection processing to be performed if it is determined that the position pointing device is within a second detection range which is closer to the operation surface than the first detection range. 
     A sensing device located under an operation surface of an information processing apparatus is also provided. The sensing device includes a first sense unit for electrically detecting whether the operation surface is directly touched, and a second sense unit for detecting whether a position pointing device approaches or contacts the operation surface based on an electromagnetic interaction generated between the second sense unit and the position pointing device. It is determined whether the position pointing device approaches within a first detection range from the operation surface and whether the position pointing device approaches within a second detection range based on an output from the second sense unit and processing based on an output from one of the first sense unit and the second sense unit is selected based on a position of the position pointing device with reference to the first and second detection ranges. The second detection range is closer to the operation surface than the first detection range. 
     An information processing apparatus having a display device with a display surface operable as an operation surface is also provided. The information processing apparatus includes a first sense unit disposed on a display surface of the display device to electrically detect whether the display surface is directly touched, a second sense unit disposed at a back side of the display device to detect whether a position pointing device approaches or contacts the display surface based on an electromagnetic interaction generated between the second sense unit and the position pointing device, an approach detecting unit for detecting whether the position pointing device approaches within a first detection range from the display surface and whether the position pointing device approaches a second detection range based on the output from the second sense unit. The second detection range is closer to the display surface than the first detection range. The information processing apparatus further includes a display control unit for disabling display processing at the display device based on an output from the first sense unit and for enabling the display device to perform display processing based on an output from the second sense unit if it is determined by the approach detecting unit that the position pointing device approaches within the second detection range. 
     An information processing apparatus having a display device with a display surface operable as an operation surface is also provided. The information processing apparatus includes a sense unit formed on a transparent substrate and having a first sensor electrode disposed on the display surface of the display device to electrically detect whether the display surface is directly touched and a second sensor electrode to detect whether a position pointing device approaches or contacts the display surface based on an electromagnetic interaction generated between the second sensor electrode and the position pointing device, and an approach detecting unit for detecting whether the position pointing device approaches within a first detection range from the display surface and whether the position pointing device approaches within a second detection range based on an output from the second sensor electrode. The second detection range is closer to the display surface than the first detection range. The information processing apparatus further includes a display control unit for disabling display processing at the display device based on an output from the first sensor electrode and enabling the display device to perform display processing based on an output from the second sensor electrode if the approach detecting unit determines that the position pointing device is within the second detection range. 
     An operation input method of accepting an input for an information processing apparatus having a display device with a display surface operable as an operation surface is also provided. The method includes first detection processing for electrically detecting whether the operation surface is directly touched, second detection processing for detecting whether a position pointing device approaches or contacts the operation surface based on an electromagnetic interaction generated the position pointing device, approach detection processing for detecting whether the position pointing device approaches a first detection range from the operation surface and whether the position pointing device approaches a second detection range based on an output from the second detection processing. The second detection range is closer to the operation surface than the first detection range. The method further includes display control processing for disabling display processing based on an output from the first detection processing and for enabling display processing to be performed based on an output from the second detection processing if the approach detection processing determines that the position pointing device approaches within the second detection range. 
     A sensing device for detecting approach or contact on a display surface of a display device is also provided. The sensing device includes a first sense unit for electrically detecting whether the display surface is directly touched, and a second sense unit for detecting whether a position pointing device approaches or contacts the display surface based on an electromagnetic interaction generated between the second sense unit and the position pointing device. Based on an output from the second sense unit, it is detected whether the position pointing device approaches within a first detection range from the display surface and whether the position pointing device approaches a second detection range. The second detection range is closer to the display surface than the first detection range. Processing based on an output from one of the first sense unit and the second sense unit is selected based on a position of the position pointing device with reference to the first and second detection ranges. 
     A sensing device usable with an information processing apparatus is also provided. The sensing device includes an operation surface having a predefined first detection region and a predefined second detection region disposed thereabove, and a sensing unit having a plurality of detection mechanisms to sense a position of a position pointing device with reference to the first and second detection regions and to selectively operate the detection mechanisms based on the sensed position of the position pointing device with reference to the first and second detection regions. 
     A method of controlling a sensing device having at least two detecting mechanisms disposed below an operation surface in an information processing apparatus is also provided. The method includes detecting a distance of a pointing device from the operation surface using a first detection mechanism with reference to first and second detection regions above the operation surface, and, if the position pointing device is in the first detection region, preparing the first detection mechanism to determine a coordinate position of the position pointing device with respect to the operation surface. If the position pointing device is in the second detection region, enabling the first detection mechanism to determine the coordinate position of the position pointing device with respect to the operation surface and enabling processing the determined coordinate position. If the position pointing device is in neither of the first and second detection regions, enabling a second detection mechanism to determine a coordinate position of contact on the operation surface and enabling processing of the determined coordinate position of the contact. 
     According to embodiments of the present invention, two types of detections are used to detect whether a position pointing device lies within a first detection range from an operation surface or display surface and to detect whether the position pointing device lies within a second detection range which is closer to the operation surface or display surface than the first range to detect a range in which the position pointing device is approaching the operation surface or display surface. Accordingly, a first sense unit and a second sense unit can be switched and operations based on detections of the respective sense units can be accepted and processed reliably. 
     In this case, an area of the first sense unit may be substantially equal to an area of the operation surface or display surface, and an area of the second sense unit is wider than the area of the first sense unit. As a result, the first and second detection ranges of the second sense unit are wider than the first sense unit. Accordingly, an input operation to directly touch the operation surface or display surface and an input operation to move the position pointing device close to the operation surface or display surface can be reliably performed. In particular, it becomes possible to detect the position pointing device as it approaches the operation surface or display surface even when the position pointing device is located at a position distant from an edge of a display surface. 
     Also, when the position pointing device is moved outside of the second detection range from when the position pointing device is located within the second detection range, and if the first sense unit determines that the operation surface or display surface is touched, then display processing based on the detected output from the first sense unit can be continuously disabled. If it is detected that the first sense unit detects that the operation surface or display surface is not being touched, then display processing based on the detected output from the first sense unit can be performed. For example, when the information processing apparatus is operated with the position pointing device, even if the operation surface or display surface is touched with a finger, an input operation based on the detected output from the first sense unit may not be resumed so long as the finger remains in contact with the operation surface or display surface temporarily. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and/or other aspects of the present invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which: 
         FIG. 1  is an perspective view illustrating a computer apparatus according to an embodiment of the present invention; 
         FIGS. 2A and 2B  are exploded assembly views illustrating a position detecting unit of the computer apparatus of  FIG. 1  according to an embodiment of the present invention; 
         FIG. 3  is a functional block diagram illustrating a computer apparatus according to an embodiment of the present invention; 
         FIG. 4  is a block diagram illustrating an electrostatic capacity position detecting unit according to another embodiment of the present invention; 
         FIG. 5  is a schematic block diagram illustrating an electromagnetic position detecting unit according to an embodiment of the present invention; 
         FIGS. 6A to 6D  are fragmentary cross-sectional views taken along the line I-I in  FIG. 2A  and illustrate states in which a position pointing device is approaching the detection ranges; 
         FIG. 7  is a flowchart illustrating a method of processing a detection operation according to an embodiment of the present invention; 
         FIG. 8  is a flowchart illustrating a method of processing a detection operation according to an embodiment of the present invention; 
         FIG. 9  is a flowchart illustrating a method of processing a detection operation when a stylus is approaching an operation surface according to an embodiment of the present invention; 
         FIG. 10  is a flowchart illustrating a method of processing a detection operation when a stylus is approaching an operation surface according to an embodiment of the present invention; 
         FIG. 11  is a flowchart illustrating a method of processing a detection operation when a touch input is being detected by an electrostatic capacity position detecting unit according to an embodiment of the present invention; 
         FIG. 12  is a flowchart illustrating a method of processing a detection operation when a stylus input is being detected by an electromagnetic position detecting unit according to an embodiment of the present invention; 
         FIG. 13  is an perspective view illustrating a computer apparatus according to another embodiment of the present invention; 
         FIG. 14  is a perspective view illustrating a layout of the computer apparatus of  FIG. 13 , according to another embodiment of the present invention; 
         FIGS. 15A to 15D  are cross-sectional views illustrating states in which a position pointing device is approaching detection ranges according to an embodiment of the present invention; 
         FIG. 16  is a perspective view illustrating parts of a computer apparatus according to another embodiment of the present invention; and 
         FIG. 17  is a perspective view illustrating parts of a computer apparatus according to an embodiment of the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT(S) 
     Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.  FIG. 1  illustrates a computer apparatus  1  according to an embodiment of the present invention. The computer apparatus  1  in  FIG. 1  may be a notebook-sized computer apparatus including an upper casing or housing  11  and a lower casing or housing  12  that can be folded in the same manner as a flip-type mobile phone. 
     The upper casing  11  has a display  13  formed of a liquid-crystal display (LCD) panel provided thereon. The display  13  includes a movable pointer  13   a  which may be controlled using various input devices. 
     The lower casing  12  includes a key input unit  14  having various keys that are operable by a user, a position detecting unit  3 , and switches  33  and  34 . 
     The key input unit  14  includes various function keys such as number keys, character keys, and symbol keys. The key input unit  14  is adapted to detect depression operations of the keys. 
     The position detecting unit  3  detects a contact position (e.g., absolute position or relative position) at which a user touches the position detecting unit  3  with a finger. An upper surface of the position detecting unit  3  is formed of a flat surface which may be substantially flush with an upper surface of the lower casing  12 . Alternatively, the upper surface of the position detecting unit  3  may be a flat surface slightly recessed with respect to the upper surface of the lower casing  12 . The upper surface of the position detecting unit  3  serves as an operation surface which can accept position input operations performed by a user&#39;s finger or other objects. 
     Also, the position detecting unit  3  is able to detect position input operations performed not only by a user&#39;s finger but also a position pointing device  2 . 
     As best shown in  FIG. 1 , the position pointing device  2  includes a pen-like casing or housing  21  and a pen-point  22  projecting from an end, i.e., a tip end, of the casing  21 . Switches  23  and  24 , which may be depressed by a user&#39;s finger, are arrayed on a side surface of the casing  21 . When the position pointing device  2  is in use, a user may hold the position pointing device  2  in the same manner in which an ink pen is held. The user holding the position pointing device  2  may press the pen-point  22  against the operation surface of the position detecting unit  3 . 
     When operated by a user, the position pointing device  2  is able to transmit a wireless signal to the position detecting unit  3  due to functions of a resonance circuit  26  and an IC (integrated circuit)  25  which will be described below with reference to  FIG. 5 . The position detecting unit  3  is able to detect a position pointed to or indicated by the position pointing device  2  by receiving the wireless signal (i.e., a position pointing signal) transmitted from the position pointing device  2 . 
     Also, using the functions of the IC  25  and the resonance circuit  26 , the position pointing device  2  can detect a pushing force (stylus pressure) applied to the pen-point  22  of the stylus when the position pointing device  2  is operated, can generate a signal indicative of the stylus pressure level and transmit the generated signal to the position detecting unit  3  together with the position pointing signal. 
     Further, using the functions of the IC  25  and the resonance circuit  26 , the position pointing device  2  can detect operational states of the switches  23  and  24 , can generate a signal indicative of the operational states of the switches  23  and  24  and transmit this signal to the position detecting unit  3  together with the position pointing signal. 
     When receiving the position pointing signal transmitted from the position pointing device  2 , the position detecting unit  3  detects the position pointed to by the position pointing device  2 . The position detecting unit  3  also detects the stylus pressure applied to the pen-point  22  of the position pointing device  2  and the operational states of the switches  23  and  24 . 
     Switches  33  and  34  are adjacent to the position detecting unit  3  and are provided on the upper surface of the lower casing  12 . The switches  33  and  34  are activated when depressed and can be operated in combination with the position detecting unit  3 . 
     Here, the operational surface of the position detecting unit  3  may be substantially rectangular and have an imaginary X-Y orthogonal coordinates system set for reference. A longer side may be assumed to correspond to an X direction and a shorter side may be assumed to correspond to a Y direction. The position detecting unit  3  may detect a position touched with a user&#39;s finger and the position pointed to by the position pointing device  2  as an absolute position or a relative position in the X-Y orthogonal coordinates system. 
     The computer apparatus  1  of  FIG. 1  is able to perform various functions by executing various application programs in accordance with instructions input by operating the key input unit  14 , the position detecting unit  3 , and the switches  33  and  34 . When the application programs are executed, various display screens relating to data being processed are displayed on the display  13 . 
     When a position pointing (input) operation is detected by the position detecting unit  3 , a position of the pointer  13   a  displayed on the display  13  is controlled/changed in response to the detected position. The change of the displayed position is performed based on control of a CPU (central processing unit)  41  (see  FIG. 3 ) which will be described below. 
       FIGS. 2A and 2B  are exploded perspective views illustrating the position detecting unit  3  of the computer apparatus  1 .  FIG. 2A  illustrates an arrangement in which a plurality of sense units are separate from each other, and  FIG. 2B  illustrates an arrangement in which a plurality of sense units are integrated with each other. 
     As illustrated in  FIG. 2A , a first sense unit  31  is located on a lower side of a surface protecting layer  311  which serves as the operation surface disposed on the surface of the lower casing  12 . The first sense unit  31  may detect whether the surface protecting layer  311  is directly touched or contacted with a user&#39;s finger or the like. The first sense unit  31  may be used to indicate a relative position. 
     A second sense unit  32  is located under the first sense unit  31 . The second sense unit  31  may detect operations performed by the position pointing device  2  (see  FIG. 1 ). The second sense unit  32  may be used to indicate an absolute position. 
     Further, a shield plate  326  is located under the second sense unit  32 . It should be noted that an auxiliary conductor plate (not shown) that can function as a ground electric potential unit of the first sense unit  31  may be disposed between the first and second sense units  31  and  32 . 
     The first sense unit  31  may have substantially the same area as that of the surface protecting layer  311 . The second sense unit  32  and the shield plate  326  may have areas that are larger than that of the first sense unit  31  in order to extend a detection range along a peripheral portion of the surface protecting layer  311 . 
       FIG. 2B  illustrates an arrangement in which a plurality of sense units are integrated with each other as one body. In this case, a composite sense unit  35  is located on the lower side of the surface protecting layer  311  as a position detecting unit  3 ′. This composite sense unit  35  is formed by integrating the first sense unit  31  and the second sense unit  32  illustrated in  FIG. 2A  as one body. 
     In this integrated arrangement, an electrode of the first sense unit  31  (see  FIG. 2A ), for example, and a loop coil of the second sense unit  32  (see  FIG. 2A ) may be alternately located in the same plane. The shield plate  326  is located under the composite sense unit  35 . 
     It should be noted that, when the first sense unit  31  and the second sense unit  32  are combined as illustrated in  FIG. 2A , the first and second sense units  31  and  32  can be constructed as an integrated sensing device. Also, the sensing device may incorporate therein circuit components operable as an electrostatic capacitance position detecting unit  50  (see  FIG. 3 ) and an electromagnetic position detecting unit  60  (see  FIG. 3 ) which will be described below. Further, the sensing device may incorporate therein a component that functions as an input unit  45  (see  FIG. 3 ) which will be described below. 
       FIG. 3  is a functional block diagram illustrating the computer apparatus  1 . 
     As illustrated in  FIG. 3 , the computer apparatus  1  includes the CPU (central processing unit)  41  for controlling respective units of the computer apparatus  1  by executing various control programs, a ROM (read-only memory)  42  for storing control programs executed by the CPU  41 , a RAM (random-access memory)  43  which serves as a work area to temporarily store programs and data processed by the CPU  41 , and a storage unit  44  for storing control programs, application programs executed by the CPU  41  and data relating to the application programs. 
     The computer apparatus  1  includes the key input unit  14  and the input unit  45 . The input unit  45  is connected to the electrostatic capacity position detecting unit  50  to detect a position of a user&#39;s finger in the position detecting unit  3  and the electromagnetic position detecting unit  60  to detect a position input operation performed by the position pointing device  2  in the position detecting unit  3 . 
     The electrostatic capacitance position detecting unit  50  detects a touch of a user&#39;s finger using the first sense unit  31  of the position detecting unit  3  and generates an operation signal indicative of the detected position. The electrostatic capacitance position detecting unit  50  may then output this operation signal to the input unit  45 . 
     Also, the electromagnetic position detecting unit  60  detects a position input operation performed by the position pointing device  2  using the second sense unit  32  of the position detecting unit  3  and generates operation signals indicative of a detected position, the stylus pressure in the position pointing device  2 , and the operational states of the switches  23  and  24 . The electromagnetic position detecting unit  60  may then output the operation signals to the input unit  45 . 
     It should be noted that when the position input operation of the position pointing device  2  is detected using the second sense unit  32 , a state in which the end (that is, pen-point  22 ) of the position pointing device  2  touches the surface protecting layer  311  may be detected and a state in which the end of the position pointing device  2  is moved close to the surface protecting layer  311  may also be detected. When the end of the position pointing device  2  is moved close to the surface protecting layer  311 , a control circuit  601  (see  FIG. 5 ) of the electromagnetic position detecting unit  60  is able to determine a rough distance between the end of the position pointing device  2  and the surface protecting layer  311 . 
     By detecting the rough distance as described above, the input unit  45  is able to perform processing operations to accept any input operation when the input operation of either of the electrostatic capacity detecting unit  50  and the electromagnetic detecting unit  60  are possible at the same time. This processing will be described in detail below. 
     It should be understood that embodiments of the present invention are not intended to be limited to the arrangement in which the control circuit  601  of the electromagnetic position detecting unit  60  performs approach detecting processing for detecting a distance in which the end of the position pointing device  2  is moved close to the surface protecting layer  311 . The CPU  41  of the computer apparatus  1  may alternatively function as an approach detecting unit by detecting when the end of the position pointing device  2  is moved close to the surface protecting layer  311 . 
     The input unit  45  generates operation information corresponding to keys in the key input unit  14  that are operated by a user. Also, the input unit  45  generates operation information indicative of a detection operation performed by the electrostatic capacitance position detecting unit  50  and the electromagnetic position detecting unit  60  based on the operation signals provided by these detection units  50  and  60 . The CPU  41  is able to execute various operations by acquiring the operation information generated by the input unit  45 . 
     Further, the computer apparatus  1  includes a display unit  46  to drive the display  13  based on screen display data input from the CPU  41  to display various screens on the display  13 . The computer apparatus  1  further includes an interface (I/F)  47  connected to various e components outside of the computer apparatus  1  to transmit and receive information between these components. The CPU  41 , the ROM  42 , the RAM  43 , the storage unit  44 , the input unit  45 , the display unit  46 , and the I/F  47  are connected to one another via a bus  48 . 
     The CPU  41  may control units of the computer apparatus  1  by executing a control program stored in the ROM  42 . The CPU  41  may also read an application program from the storage unit  44  and execute the application program in the work area provided by the RAM  43  to process various data. 
     During execution of the control program and the application program, the CPU  41  may generate the screen display data for display screens relating to the programs being executed and output the same to the display unit  46 . Accordingly, the display screens can be displayed on the display  13 . 
     Also, when the operation information which corresponds to the position input operation performed by a user&#39;s finger or the position input operation performed by the position pointing device  2  is provided to the CPU  41  by the input unit  45 , the CPU  41  may determine (or discriminate among) content being pointed to or indicated based on the operation information and the screen display data of the display screen being output to the display unit  46 . In this manner, the CPU  41  may execute functions and processing operations based on the content which is being pointed to or indicated by the position input operation. 
       FIG. 4  is a functional block diagram illustrating the electrostatic capacitance position detecting unit  50 . As illustrated in  FIG. 4 , the electrostatic capacitance position detecting unit  50  includes the first sense unit  31  of the position detecting unit  3  and an electrostatic capacitance detecting unit (circuit)  51  connected to electrodes of the first sense unit  31 . 
     The electrostatic capacitance detecting circuit  51  applies a predetermined voltage to each of a plurality of electrodes in the first sense unit  31  such that a predetermined electrostatic capacitance is generated between opposing electrodes. When a user&#39;s finger touches the operation surface of the position detecting unit  3 , the electrostatic capacitance between the opposing electrodes is changed. Based on the change in electrostatic capacitance, the electrostatic capacitance detecting circuit  51  may specify the electrodes having the respective electrostatic capacitancey changed considerably. Accordingly, the position at which a user&#39; finger touches the operation surface of the position detecting unit  3  may be obtained by executing calculations based on the corresponding position and a degree to which the electrostatic capacitance is changed. The electrostatic capacitance detecting circuit  51  may also calculate corresponding coordinates (e.g., absolute position coordinates or relative position coordinates). Further, the electrostatic capacitance detecting circuit  51  generates an operation signal indicative of the calculated coordinates and outputs the operation signal to the input unit  45  (see  FIG. 3 ). 
       FIG. 5  is a schematic block diagram illustrating the electromagnetic position detecting unit  60 . As illustrated in  FIG. 5 , the electromagnetic position detecting unit  60  includes first loop coils  322  and second loop coils  324  of the position detecting unit  3  connected to an electromagnetic detecting circuit (unit)  600 . 
     It should be noted that the position pointing device  2  is also shown in  FIG. 5  together with the electromagnetic position detecting unit  60  in order to describe the present invention more clearly. 
     The position detecting device  2  includes the resonance circuit  26  having a coil (not shown) and a capacitor (not shown), and the IC (integrated circuit)  25  connected to the resonance circuit  26 . 
     The electromagnetic detecting circuit  600  includes a selecting circuit  602  to select a loop coil from among the plurality of loop coils  322  and  323  of the position detecting unit  3 . The electromagnetic detecting circuit  600  further includes a transmission and reception switching circuit  603  to switch between a transmission mode to transmit a signal via the loop coil selected by the selecting circuit  602  and a reception mode to receive a signal from the position pointing device  2  via the loop coil selected by the selecting circuit  602 . 
     The electromagnetic detecting circuit  600  further includes a control circuit  601  to control units/components of the electromagnetic detecting unit  600 , an amplifying circuit  601  to amplify a signal output from the transmission and reception switching circuit (detector)  603 , a BPF (bandpass filter)  605  to pass only a signal component of a predetermined frequency band with respect to the signal amplified by the amplifying circuit  604 , a detecting circuit  606  to convert the signal component passed through the BPF  605  into a voltage value, a sample-and-hold (S/H) circuit  607  to hold this voltage value during a predetermined time period, an A/D (analog-to-digital) converting circuit  608  to convert the voltage value held in the sample-and-hold circuit  607  into digital data and to output the digital data to the control circuit  601 , a signal generating circuit  609  for generating an oscillation signal with a predetermined frequency based on control of the control circuit  601 , and an amplifying circuit  610  to amplify the signal generated by the signal generating circuit  609  and to output the amplified signal to the transmission and reception switching circuit  603 . 
     The manner in which the electromagnetic detecting circuit  600  detects a position input operation performed by the position pointing device  2  will now be described. 
     First, the control circuit  601  controls the selecting circuit  602  to select one loop coil and controls the transmission and reception switching circuit  603  to switch the operation mode to the transmission mode. 
     The control circuit  601  then controls the signal generating circuit  609  to generate a signal with a predetermined frequency. The signal is amplified by the amplifying circuit  610  and provided through the transmission and reception switching circuit  603  to the selecting circuit  602 . Accordingly, an electric current corresponding to the amplified signal is provided to the loop coil selected by the selecting circuit  602 . The electric current flows through the selected loop coil, and as a result, a magnetic field (alternating field) is generated around the selected loop coil. 
     Here, in the position pointing device  2 , an induced electric current may flow to the resonance circuit  26  due to the magnetic field generated around the selected loop coil of the electromagnetic detecting circuit  600  to enable the IC  25  to begin operation. The IC  25  generates a signal with a predetermined frequency relative to the resonance circuit  26  and provides the generated signal to the resonance circuit  26  to be transmitted to the electromagnetic detecting circuit  600 . 
     The control circuit  601  of the electromagnetic detecting circuit  600  switches the operation mode to the reception mode by controlling the transmission and reception switching circuit  603  after operating in the transmission mode for a predetermined time period. When the operation mode is switched to the reception mode as described above, the signal from the signal generating circuit  609  is no longer output to the selecting circuit  602 . 
     In the reception mode, the signal transmitted from the position pointing device  2  due to operation of the IC  25  is received by the loop coil selected by the selecting circuit  602 . More specifically, when the IC  25  is operated, the signal is applied to the resonance circuit  26  and an electric current corresponding to the signal generated by the IC  25  flows through the resonance circuit  26 . As a result, a magnetic field is generated around the resonance circuit  26 , which causes an induced electric current to flow through the loop coils  322  and  324 . 
     The electric current flowing through the selected loop coil is amplified by the amplifying circuit  604  and only the signal component of the predetermined frequency band is output to the detecting circuit (detector)  606  by the BPF  605 . The signal component in the passband of the BPF  605  is then converted into a voltage value by the detecting circuit  606  and held in the sample-and-hold (S/H) circuit  607 . The voltage value held in the sample-and-hold circuit  607  is then converted into digital data by the A/D converting circuit  608  and output to the control circuit  601 . 
     Then, while the loop coils  322  and  324  are sequentially being selected by the selecting circuit  602 , the control circuit  601  may specify the loop coil closest to the position pointed to by the position pointing device  2  and may determine coordinates of the pointed position by processing the digital data input from the A/D converting circuit  608 . 
     Also, while the electric current is flowing through the resonance circuit  26 , the IC  25  in the position pointing device  2  detects the stylus pressure applied to the pen-point  22  (see  FIG. 1 ) and the operational states of the switches  23  and  24  (see  FIG. 1 ). Based on the stylus pressure and the operational states of the switches  23  and  24 , the IC  25  may change transmission timing and transmission time of the oscillation signal provided to the resonance circuit  26 . The changes in the transmission timing and the transmission time may subsequently be detected during the processing performed when the voltage value held in the sample-and-hold circuit  607  is converted into digital data by the A/D converting circuit  608 . 
     Accordingly, the control circuit  601  in the electromagnetic detecting circuit  600  may acquire the stylus pressure and the operational states of the switches  23  and  24  by calculating or otherwise processing the digital data input from the A/D converting circuit  608 . 
     The control circuit  601  then generates an operation signal indicative of the position pointed to by the position pointing device  2 , the stylus pressure in the position pointing device  2 , and the operational states of the switches  23  and  24  and outputs the operation signal to the input unit  45  (see  FIG. 3 ). 
     It should be noted that while the pen-shaped position pointing device  2  includes the IC  25  in the arrangement illustrated in  FIG. 5 , the present invention is not intended to be limited to this type of arrangement. The pen-shaped position pointing device  2  may, in some embodiments, not include the IC  25 . 
     The computer apparatus  1  includes the electrostatic capacitance position detecting unit  50  to detect the input operation performed by a user&#39;s finger and the electromagnetic position detecting unit  60  to detect the position input operation performed by the position pointing device  2 . As a result, the computer apparatus  1  is able to individually detect an input operation on the operation surface of the position detecting unit  3  performed by a user&#39;s finger or the position pointing device  2 . Consequently, it becomes possible for a user to perform input operations using a plurality of methods with different feels of operation, and operability can be improved. 
     Also, since the position detecting unit  3  is arranged such that the first sense unit  31 , which detects an operation performed by a user&#39;s finger, and the second sense unit  32 , which detects an operation performed by the position pointing device  2 , are positioned upon one another in the lower casing  12  of the computer apparatus  1 , the position detecting unit  3  can be easily applied to small and portable electronic devices having a casing (housing) size that is limited. 
     An input operation based on detection at the electrostatic capacitance detecting unit  50  and an input operation based on detection at the electromagnetic position detecting unit  60  are inhibited (disabled) from being performed at the same time, and the computer apparatus  1  may accept only one of the above input operations. 
     Operational states in which two detection operations are processed (e.g., contact detection at the first sense unit  31  and contact or close detection at the second sense unit  31 ) are executed selectively will now be described. 
       FIGS. 6A to 6D  are schematic cross-sectional views taken along the line I-I in  FIG. 2A  and illustrate states in which the position pointing device  2  is approaching detection ranges of the position detecting unit  3 . As shown in  FIG. 6A , the first and second sense units  31  and  32  are located at the lower portion of the surface protecting layer  311 . 
     The first sense unit  31  is adapted to detect whether the surface protecting layer  311  is directly touched with a user&#39;s finger. The second sense unit  32  is adapted to detect whether the end  22  of the position pointing device  2  approaches or contacts the surface protecting layer  311 . 
     In order to detect whether the end  22  of the position pointing device  2  approaches the surface protecting layer  311 , as shown in  FIG. 6A , a first detection range d 1  is defined by when the end  22  is less than a first height h 1  from the surface protecting layer  311 , and a second detection range d 2  is defined by when the end  22  approaches the surface protecting layer  311  and is less than a second height h 2  from the surface protecting layer  311 . As illustrated in  FIG. 6A , the second height h 2  is less than the first height h 1 . 
     The control circuit  601  (see  FIG. 5 ) of the electromagnetic position detecting unit  60  is adapted to determine whether the end  22  of the position pointing device  2  lies within the first detection range d 1  or the second detection range d 2 . The first height h 1  may be about several centimeters, for example, and the second height h 2  may be about 1 centimeter, for example. 
     In the present embodiment, the area of the second sense unit  32  may be larger than that of the first sense unit  31 . Here, the first and second detection ranges d 1  and d 2  extend beyond a peripheral portion of the surface protecting layer  311 . 
       FIGS. 6A to 6D  illustrate the states in which the position of the end  22  of the position pointing device  2  is being changed. The control circuit  601  (see  FIG. 5 ) is able to detect and discriminate among the four states illustrated in  FIGS. 6A and 6D , respectively. 
     More specifically,  FIG. 6A  illustrates a state in which the end  22  of the position pointing device  2  lies outside the first detection range d 1 .  FIG. 6B  illustrates a state in which the end  22  of the position pointing device  2  lies within the first detection range d 1  but outside the second detection range d 2 .  FIG. 6C  illustrates a state in which the end  22  of the position pointing device  2  lies within the second detection range d 2 .  FIG. 6D  illustrates a state in which the end  22  of the position pointing device  2  is in contact with the surface protecting layer  311 . 
     It should be noted that when the end  22  of the position pointing device  2  is brought in contact with the surface protecting layer  311 , pressure (i.e., the stylus pressure) with which the end  22  of the position pointing device  2  contacts the surface protecting layer  311  can be determined based on a signal from the position pointing device  2 . 
     As illustrated in  FIGS. 6A to 6D , since the area of the second sense unit  32  is larger than that of the first sense unit  31 , the first and second detection ranges d 1  and d 2  extend slightly beyond the surface protecting layer  311  based on the differences in area. That is, the first detection range d 1  has a greater width than the second detection area d 2 . Accordingly, when the position pointing device  2  approaches the surface protecting layer  311  from a lateral direction, it is possible to reliably detect the approach of the position pointing device  2  to the surface protecting layer  311 . 
     Based on the various detection states, the control circuit  601  (see.  FIG. 5 ) issues an interrupt request to the input unit  45  of the computer apparatus  1 . When certain conditions are satisfied, input processing based on an output from the electromagnetic position detecting unit  60  is executed with a priority over input processing based on an output from the electrostatic capacity position detecting unit  50 . 
       FIG. 7  is a flowchart illustrating a method of processing a detection operation according to an exemplary embodiment of the present invention. The method of  FIG. 7  may be performed by the computer apparatus  1  of  FIG. 1  and/or the control circuit  601  of  FIG. 5 . The method of  FIG. 7  is used to select input processing based on the outputs from the two detecting units  50  and  60 . 
     It should be noted that in the description that follows, electrostatic capacitance contact detection in the first sense unit  31  will be referred to as a “touch input” and electromagnetic detection at the second sense unit  32  using the position pointing device  2  will be referred to as a “stylus input.” 
     First, referring to  FIG. 7 , it is determined at step S 11  whether the end  22  of the stylus  2  is inside of a first range (e.g., the first detection range d 1 ) shown in  FIGS. 6A to 6D . If the pen-point  22  of the stylus  2  is determined to be outside of the first detection range as represented by a “NO” at step S 11 , then the control circuit  601  of the electromagnetic position detection unit  60  is set to a standby state and an operator is able to perform a touch input. If the pen-point of the stylus is determined to be inside of the first detection range d 1  as represented by a “YES” at step S 11 , then control goes to a step S 12  and control circuit  601  of the electromagnetic position detecting unit  60  performs preparation processing and enters a state or mode in which stylus input processing can be performed. In this state, the control circuit  601  can quickly determine whether the pen-point  22  of the stylus  2  lies within the second detection range d 2 . 
     At step S 13 , it is determined whether the pen-point  22  of the stylus  2  is inside of the second detection range d 2 . If the pen-point  22  of the stylus  2  is inside of the second detection range d 2  as represented by a “YES” at step S 13 , then step S 14  is performed. At step S 14 , touch input processing is inhibited (i.e., disabled). 
     At step S 15 , stylus input processing detection data is supplied to the input unit  45  (see  FIG. 3 ) and display control is executed based on the detection data. At step S 16 , display control is performed based on an approaching distance of the pen-point  22  and the stylus pressure. At step S 17 , it is then determined whether the pen-point has moved outside of the second detection range d 2 . If the pen-point  22  has not moved outside of the second detection range d 2  (that is, the pen-point  22  still lies within the second detection range d 2 ) as represented by a “NO” at step S 17 , then the steps S 14  to S 16  are repeated. 
     If on the other hand, the pen-point of the stylus  2  lies outside of the second detection range d 2  as represented by a “YES” at step S 17 , then step S 18  is performed. At step S 18 , the detection data of the stylus input is not supplied to the input unit  45  and the control circuit  601  of the electromagnetic position detecting unit  60  is set to the standby mode. Then, the method is continued at step S 13 . 
     If the pen-point  22  of the stylus  2  lies outside of the second detection range d 2  as represented by a “NO” at step S 13 , then step S 19  is performed. At step S 19 , it is determined whether the pen-point  22  of the stylus  2  lies outside the first detection range d 1 . If the pen-point  22  of the stylus  2  is not outside of the first detection range d 1  as represented by a “NO” at step S 19 , then the method continues at step S 13 . If the pen-point  22  of the stylus  2  lies outside of the first detection range d 1  as represented by a “YES” at step S 19 , then the method continues at step S 20  in which the control circuit  601  is set to a state in which the touch input processing can be performed. At step S 21 , the stylus input preparation is stopped and the method continues at step S 11 . 
     A flowchart illustrated in  FIG. 8  illustrates another exemplary method of selecting an input processing selection state based on the outputs from the two detecting units  50  and  60 . In the flowchart of  FIG. 8 , some of the same steps as the flowchart of  FIG. 7  are represented by the same reference numbers. 
     Referring to  FIG. 8 , it is determined at step S 11  whether the pen-point  22  of the stylus  2  is inside of the first detection range d 1 . If the pen-point  22  of the stylus  2  is determined to be inside of the first detection range d 1  as represented by a “YES” at the decision step S 11 , then step S 14 ′ is performed. At step S 14 ′, the touch processing is inhibited (disabled). Once the touch processing is inhibited, step S 12  is performed, and the stylus input processing state is prepared. 
     Then, it is determined at step S 13  whether the pen-point  22  of the stylus  2  is inside of the second detection range d 2 . If the pen-point  22  of the stylus  2  is inside of the second detection range d 2  as represented by a “YES” at step S 13 , then step S 15  is performed. At step S 15 , stylus input processing detection data is supplied to the input unit  45  and display control is executed based on the detection data. Then, step S 16  is performed in which display control processing is executed according to the approaching distance of the pen-point  22  of the stylus  2  and the stylus pressure. The remaining steps of the method of  FIG. 8  may be the same as the method of  FIG. 7 . 
     Next, examples of detailed processing performed at step S 16  of the methods of  FIGS. 7 and 8  will be described with reference to flowcharts shown in  FIG. 9  and  FIG. 10 . The detailed processing of  FIGS. 9 and 10  may be performed by the computer apparatus  1  of  FIG. 1  or the control circuit  601  of  FIG. 5 . 
     Referring to  FIG. 9 , it is determined at step S 31  whether the pen-point  22  of the stylus  2  touches the surface protecting layer  311 . If the pen-point of the stylus  2  does not touch the surface protecting layer  311  as represented by a “NO” at step S 31 , then ordinary display processing is performed to change a display position of the pointer  13   a  (see  FIG. 1 ) displayed on the screen in response to the detection position. 
     If the pen-point  22  of the stylus  2  touches the surface protecting layer  311  as represented by a “YES” at step S 31 , then step S 32  is performed. At step S 32 , processing is performed according to a contact position (i.e., a touched position) to change the display position of the pointer  13   a  and also to select the pointed position (e.g., which may correspond to display data on the display  13 ) at the same time. 
     Referring to  FIG. 10 , it is assumed that a mode is set in which a line is drawn in response to a change in the contact position at which the pen-point  22  of the stylus  2  touches the surface protecting layer  311 . In this case, at step S 33 , the stylus pressure with which the pen-point  22  of the stylus  2  touches the surface protecting layer  311  is detected. Then, step S 34  is performed in which a width of the line drawn on the display screen is changed in response to a change in the detected stylus pressure. That is, if the stylus pressure is small, then a handwritten trace corresponding to the change of stylus position is displayed by a thin trace width. If the stylus pressure is large, then the handwritten trace corresponding to the change of the stylus position is displayed by a thick trace width. 
     Next, processing performed when a touch input is being detected will be described with reference to the flowchart of  FIG. 11 , and processing performed when the stylus input is being detected will be described with reference to the flowchart of  FIG. 12 . 
     Referring to  FIG. 11 , a touch input is detected at step S 41 . Then, at step S 42 , it is determined whether the pen-point  22  of the stylus  2  is inside of the second detection range d 2 . If the pen-point of the stylus  2  is determined to be inside of the second detection range, as represented by a “YES” at step S 42 , then step S 43  is performed. In step S 43 , processing based on detection of pen-point position of the stylus  2  is performed with priority and processing based on touch input is inhibited (disabled). 
     Referring to  FIG. 12 , the pen-point  22  of the stylus  2  is detected within the second detection range d 2  and display control processing based on the stylus input is performed at step S 51 . At step S 52 , it is determined whether the pen-point  22  of the stylus  2  touches the surface protecting layer  311 . If a touch input is detected, as represented by a “YES” at step S 52 , then step S 53  is performed. In step S 53 , inhibition of touch input is continued. 
     Then, step S 54  is performed. Here, it is determined whether the pen-point  22  of the stylus  2  has moved outside of the second detection range d 2 . If the pen-point  22  of the stylus  2  is determined not to be outside of the second detection range d 2  (that is, the pen-point  22  of the stylus  2  lies within the second detection range d 2 ) as represented by a “NO” at step S 54 , then inhibition of the touch input is continued and the control circuit  601  is set to operate in the standby mode. If on the other hand, the pen-point of the stylus has moved outside of the second range, as represented by a “YES” at step S 54 , then step S 55  is performed. It is determined at step S 55  whether a touch input is being detected continuously. 
     If the touch input is being detected continuously as represented by a “YES” at step S 55 , then the method is continued at step S 53 , where inhibition of the touch input is continued, regardless of a change in position of the pen-point  22  of the stylus  2 . If on the other hand, the touch input is not detected continuously as represented by a “NO” at step S 55 , then step S 56  is performed. In step S 56 , inhibition of the touch input is cancelled. If the touch input is subsequently detected, then the control circuit  601  is set to operate in a state which accepts a touch input. 
     According to the processing illustrated  FIG. 12 , when the position pointing device  2  is brought in contact with the surface protecting layer  311 , even if the surface protecting layer  311  is touched by fingers that grip the position pointing device  2 , it is possible to effectively prevent a malfunction from occurring. 
     More specifically, even when the pen-point  22  of the pen-shaped position pointing device  2  is temporarily detached from the surface protecting layer  311  by a relatively large distance when the surface protecting layer  311  is touched by the fingers that grip the position pointing device  2 , so long as the fingers that touch the surface protecting layer  311  are once completely detached from the surface protecting layer  311 , touch input processing is not executed and the control circuit  601  is set to the standby mode in which the stylus input processing becomes possible. Accordingly, it is possible to prevent malfunction caused by the touch input according to a change in a temporary stylus input contact state. 
     While the position pointing device  2  is able to point to the specific position by transmitting and receiving a wireless signal to and from the position detecting unit  3  in the embodiments described above, the present invention is not intended to be limited to this arrangement. For example, the position pointing device  2  may include a built-in power supply apparatus so that the position pointing device  2  may transmit a signal to the position detecting unit  3  in a one-way fashion. 
     Also, while the embodiments of the present invention have been described as applied to a notebook-sized computer apparatus, it should be understood that the embodiments of the present invention can be applied to input devices connected to an information processing apparatus, such as a desktop-sized computer apparatus, among other devices. More specifically, the position detecting unit  3  including the first sense unit  31  and the second sense unit  32  may be constructed as a position detecting apparatus (input device) in which the position detecting unit  3  is housed within a single casing, and the position detecting apparatus may be connected to the information processing apparatus, such as a computer, by a suitable wire cable, such as a USB (universal serial bus) cable. Alternatively, the position detecting apparatus may transmit a signal to the information processing apparatus in a wireless fashion. 
     The embodiments of the present invention may also be applied to input units of a portable information processing apparatus, such as a PDA (personal digital assistant), an electronic dictionary, a mobile phone, and/or a portable game machine. 
     Also, while the first sense unit  31  has been described above as the electrostatic capacitance position detecting unit and the second sense unit  32  has been described as the electromagnetic position detecting unit, the embodiments of the present invention are not limited to this arrangement. The first sense unit  31  may be a position detecting unit capable of directly detecting contact or touch using other detecting mechanisms. 
       FIG. 13  is an external view illustrating a computer apparatus  1 ′ according to another embodiment of the present invention. The computer apparatus  1 ′ illustrated in  FIG. 13  may be a tablet-type computer apparatus which can be operated by stylus input. The computer apparatus  1 ′ includes a display panel  13 ′, which may be a liquid-crystal display panel or an EL (electro-luminescence) display. The display panel  13 ′ includes a first sense unit  31 ′ (see  FIG. 14 ) and a second sense unit  32 ′ as operation input devices. It should be noted that the computer apparatus  1 ′ may also include other operation input devices, such as a keyboard and a pointing device. 
     The first sense unit  31 ′ is a position detecting apparatus for detecting a contact position (e.g., an absolute position or relative position) at which a surface of the display panel  13 ′ is touched with a user&#39;s finger. 
     The second sense unit  32 ′ is able to detect a position input operation performed by the position pointing device  2 , which may be provided independently of the computer apparatus  1 ′. 
     The position pointing device  2  includes the pen-like casing  21  and the end (pen-point)  22  projecting from the end  22  of the pen-shaped casing  21 . When the position pointing device  2  is in use, a user can hold the position pointing device  2  in exactly the same manner as an ink pen or stylus. In this manner, a user presses the end (or pen-point)  22  against the display surface of the display panel  13 ′. It should be noted that the position pointing device  2  in this embodiment of the present invention may or may not include a power supply such as a battery. 
     When operated by a user, the position pointing device  2  transmits a wireless signal to the second sense unit  32 ′ due to operation of the resonance circuit  26  and the IC  25  disposed within the position pointing device  2  illustrated in  FIG. 5 . 
     The second sense unit  32 ′ detects the position pointed to by the position pointing device  2  by receiving the wireless signal transmitted from the position pointing device  2 . Also, based on the operation of the IC  25  and the resonance circuit  26 , the position pointing device  2  detects stylus pressure applied to the pen-point  22 , generates a signal indicative of stylus pressure level, and transmits the signal to the second sense unit  32 ′ together with a signal which points to the position (i.e., a position pointing signal)based on operation of the IC  25  and the resonance circuit  26 . 
     The second sense unit  32 ′ detects the position pointed to by the position pointing device  2  and detects the stylus pressure applied to the pen-point  22  when receiving the signal transmitted from the position pointing device  2 . 
     The first sense unit  31 ′ is shaped and positioned to detect contact with substantially the same area as that of the display surface of the display panel  13 ′. The second sense unit  32 ′ is shaped and positioned so as to detect whether the position pointing device  2  is approaching or contacts the display surface of the display panel  13 ′ in an area (indicated a broken line in  FIG. 13 ) slightly larger than that of the display surface of the display panel  13 ′. 
     The first and second sense units  31 ′ and  32 ′ have flat detection surfaces which may be substantially square. Additionally, the detection surfaces of the first and second sense units  31 ′ and  32 ′ may have an imaginary X-Y orthogonal coordinates system defined therein for reference, in which a long side direction is assumed to be an X direction and a short side direction is assumed to be a Y direction. 
     The first and second sense units  31 ′ and  32 ′ are able to detect (1) the position at which a user&#39;s finger touches the display surface of the display panel  13 ′ and (2) the position pointed to by the position pointing device  2 , for example, as an absolute position or a relative position in the X-Y orthogonal coordinates system. 
     The computer apparatus  1 ′ performs various functions by executing different application programs based on instructions from operation inputs detected by the first and second sense units  31 ′ and  32 ′. When the application programs are executed, various display screens relating to data being processed are displayed on the display panel  13 ′. When the pointing of the position is detected by the first and second sense units  31 ′ and  32 ′, a displayed position of the pointer  13   a  displayed on the display panel  13 ′ may be controlled or changed in response to the detected position. The displayed position of the pointer  13   a  may be changed based on display control of the CPU  41  (see  FIG. 3 ). 
       FIG. 14  is an exploded perspective view illustrating the computer apparatus  1 ′. As illustrated in  FIG. 14 , the first sense unit  31 ′ is located on the display surface of the display panel  13 ′ and the second sense unit  32 ′ is located at a back side of the display panel  13 ′. The display panel  13 ′ may be an LCD panel or other type of display device. 
     The first sense unit  31 ′ includes a transparent substrate on which transparent electrodes are disposed. The second sense unit  32 ′ may be slightly larger in size than the display surface of the display panel  13 ′ such that its detection range is larger around a peripheral portion. 
     If the display panel  13 ′ is a liquid-crystal display panel, for example, a backlight may be housed within the display panel  13 ′, and the second sense unit  32 ′ may be located on a back side of the backlight. 
     The first and second sense units  31 ′ and  32 ′ may incorporate therein circuit assemblies operable as the electrostatic capacitance position detecting unit  50  and the electromagnetic position detecting unit  60  of  FIG. 3 . More specifically, circuit assemblies operable as the detecting units may be mounted on the peripheral portion of the substrate constructing these sense assemblies, for example. Alternatively, a relatively small substrate in which circuit assemblies operable as detecting units are mounted may be connected to the peripheral portion of the substrate constructing the sense part and thereby formed as an integrated sense part. 
     A functional arrangement of the computer apparatus  1 ′ may be the same as the arrangement that is described above with reference to  FIG. 3 . The computer apparatus  1 ′ may be different only in that the display  13  shown in  FIG. 3  is replaced with the display panel  13 ′. 
     Although not shown in  FIGS. 13 and 14 , the computer apparatus  1 ′ may include the electrostatic capacitance position detecting unit  50  described above with reference to  FIG. 4 . In this case, the electrostatic capacitance position detecting unit  50  may include the first sense unit  31 ′. Similarly, although not shown in  FIGS. 13 and 14 , the computer apparatus  1 ′ may include the electromagnetic position detecting unit  60  described above with reference to  FIG. 4 . In this case, the electromagnetic position detecting unit  60  may include the second sense unit  32 ′. The electromagnetic position detecting unit  60  includes the loop coils  322  and the loop coils  324  of the second sense unit  32 ′ connected to the electromagnetic system detecting circuit  600 . 
     The arrangement and detection operations of the electromagnetic system position detecting unit  60  are the same as those of the arrangement of the electrostatic capacitance system position detecting unit  60  that has been described so far with reference to  FIG. 5  in the first embodiment of the present invention. More specifically, as shown in  FIG. 5 , the electromagnetic system position detecting unit  60  has an arrangement in which respective loop coils  612  and respective loop coils  613  of the second sense unit  32 ′ are connected to an electromagnetic system detecting circuit (electromagnetic system detection function unit)  600 . Each loop coil  612  is a coil located in the X-axis direction and each loop coil  613  is a coil located in the Y-axis direction. 
     The computer apparatus  1 ′ includes the electrostatic capacitance position detecting unit  50  to detect position input operations performed by a user&#39;s finger and the electromagnetic position detecting unit  60  to detect position input operations performed by the position pointing device  2 . Hence, the computer apparatus  1 ′ is able to individually detect the position input operations performed by a user&#39;s finger on the display surface and the position input operations performed by the position pointing device  2 . Consequently, it is possible to perform input operations using a plurality of methods with different feels of operation and operability can be improved. 
     Also, as shown in  FIG. 14 , since the first sense unit  31 ′ which detects a user&#39;s finger and the second sense unit  32 ′ which detects the position pointing device  2  are disposed on opposite sides of the display panel  13 ′, embodiments of the present invention can be easily applied to small equipment having a casing size that is limited. 
     The input operation based on detection by the electrostatic capacitance position detecting unit  50  using the first sense unit  31 ′ and the input operation based on detection by the electromagnetic position detecting unit  60  using the second sense unit  32 ′ are prevented from being performed at the same time and only one input operation may be accepted based on operational states in order to prevent erroneous results. In some cases, both of the input operations may not be accepted. 
     Next, a state in which processing of an electrostatic capacity system contact detection at the first sense unit  31 ′ and an electromagnetic contact detection or approach detection of the position pointing device  2  at the second sense unit  32 ′ are selectively performed will be described below. 
       FIGS. 15A to 15D  are cross-sectional views illustrating the display panel  13 ′ of the computer apparatus  1 ′ according to an embodiment of the present invention. 
     As shown in  FIG. 15A , the first sense unit  31 ′ and the second sense unit  32 ′ are disposed on opposite sides (i.e., a display side and a rear side) of the display panel  13 ′. The first sense unit  31 ′ is formed as the display surface of the display panel  13 ′. 
     The first sense unit  31 ′ detects whether the surface of the display panel  13 ′ is directly touched with a user&#39;s finger. The second sense unit  32 ′ detects whether the end (pen-point)  22  of the position pointing device  2  approaches or contacts the surface of the display panel  13 ′. 
     In order to detect whether the end  22  of the pen-shaped position pointing device  2  approaches or contacts the surface of the display panel  13 ′, as shown in  FIG. 15A , the first detection range d 1  is set to detect whether the pen-point  22  of the position pointing device  2  is less than the first height h 1  from the surface of the display panel  13 ′ and the second detection range d 2  is set to detect whether the pen-point  22  of the position pointing device  2  is less than the second height h 2  from the surface of the display panel  13 ′. The second height h 2  is less than the first height h 1 . 
     Accordingly, the control circuit  601  (see  FIG. 5 ) of the electromagnetic position detecting unit  60  determines whether the end  22  of the position pointing device  2  lies within the first detection range d 1  and whether the end  22  of the position pointing device  2  lies within the second detection range d 2 . 
     The first height h 1  may be a height of approximately several centimeters and the second height h 2  may be a height of approximately 1 cm. 
     The area of the second sense unit  32 ′ is larger than that of the first sense unit  31 ′, and the first and second detection ranges d 1  and d 2  extend beyond a peripheral portion of the display panel  13 ′ where nothing is displayed. 
     The operational states shown in  FIGS. 15A to 15D  illustrate changes in positions of the end (pen-point)  22  of the position pointing device  2 . The control circuit  601  (see  FIG. 5 ) is able to discriminate among and detect these four states shown in  FIGS. 15A to 15D , respectively. 
     More specifically,  FIG. 15A  illustrates a state in which the end  22  of the position pointing device  2  lies outside of the first detection range d 1 .  FIG. 15B  illustrates a state in which the end  22  of the position pointing device  2  lies within the first detection range d 1  and outside of the second detection range d 2 .  FIG. 15C  illustrates a state in which the end  22  of the position pointing device  2  lies within the second detection range d 2 .  FIG. 15C  illustrates a state in which the end  22  of the position pointing device  2  contacts the surface of the display panel  13 ′. 
     It should be noted that when the end  22  of the position pointing device  2  contacts the surface of the display panel  13 ′ as shown in  FIG. 15D , it is possible to determine the stylus pressure using the signal from the position detecting device  2 . 
     As shown in  FIGS. 15A to 15D , since the area of the second sense unit  32 ′ is larger than that of the first sense unit  31 ′, the first and second detection ranges d 1  and d 2  extend slightly further along a plane. According to this arrangement, even when the position pointing device  2  approaches the surface of the display panel  13 ′ from a lateral direction, it is possible to positively detect the approach of the position pointing device  2  in the first and second detections ranges d 1  and d 2 . 
     Then, based on the various types of detection states shown in  FIGS. 15A to 15D , the control circuit  601  (see  FIG. 5 ) issues an interrupt request to the input unit  45  of the computer apparatus  1 ′. When certain conditions are satisfied, input processing based on an output from the electromagnetic position detecting unit  60  (see  FIG. 5 ) may be performed with priority over input processing based on an output from the electrostatic capacity position detecting unit  50  (see  FIG. 5 ). 
     The switching between the touch input and the stylus input which is described above with reference to the flowcharts shown in  FIG. 7  and/or  8  may be applied to the input processing selection states based on the outputs from the two detecting units  50  and  60 . 
     Referring to  FIGS. 7 and 15A  to  15 D, it is determined at step S 11  whether the end  22  of the position pointing device  2  is inside of the first detection range d 1 . If the end  22  of the position pointing device  2  lies outside of the first detection range d 1  as represented by a “NO” at step S 11 , then the control circuit  601  of the electromagnetic position detecting unit  60  (see  FIG. 5 ) is set to the standby mode in which only the touch input is enabled. If on the other hand the pen-point  22  of the position pointing device  2  is determined to be inside of the first detection range d 1  as represented by a “YES” at the decision step S 11 , then step S 12  is performed. In step S 12 , preparation processing for a stylus input is performed. The preparation processing is performed such that it can be quickly determined whether the end  22  of the position pointing device  2  lies within the second detection range d 2 . 
     Then, step S 13  is performed, in which it is determined whether the end  22  of the position pointing device  2  is inside of the second detection range d 2 . If the end  22  of the position pointing device  2  is determined to be inside of the second detection range d 2  as represented by a “YES” at step S 13 , then step S 14  is performed. In step S 14 , the touch input and touch input processing is inhibited (i.e., disabled). 
     At step S 15 , detection data of the stylus input processing is supplied to the input unit  45  and display control based on the detection data is performed. Next, step S 16  is performed in which the display control processing corresponding to a distance of the end  22  of the position pointing device  2  from the display panel  13 ′ and the stylus pressure is performed. 
     At step S 17 , it is determined whether the end  22  of the position pointing device  2  is moved outside of the second detection range d 2 . If the end  22  of the position pointing device  2  is not outside of the second detection range d 2  (that is, the end  22  of the position pointing device  2  lies within the second detection range d 2 ) as represented by a “NO” at step S 17 , then steps S 14  to S 16  are repeatedly performed. 
     If on the other hand, the end  22  of the position pointing device  2  is determined to have been moved outside of the second detection range d 2  as represented by a “YES” at step S 17 , then step S 18  is performed. At step  18 , detection data is not supplied to the input unit  45  and the control circuit  601  of the electromagnetic position detecting unit  60  (see  FIG. 5 ) is set to the standby mode and step S 13  is performed. 
     If it is determined at step S 13  that the end  22  of the position pointing device  2  does not lie within the second detection range d 2 , then step S 19  is performed. In step S 19 , it is determined whether the end  22  of the position pointing device  2  is moved outside of the first detection range d 1 . If the end  22  of the position pointing device  2  is not outside of the first detection range d 1  as represented by a “NO” at step S 19 , then step S 13  is performed again. If on the other hand, the end  22  of the position pointing device  2  is moved outside of the first detection range d 1  as represented by a “YES” at step S 19 , then step S 20  is performed. At step S 20 , the control circuit  601  of the electromagnetic position detecting unit  60  (see  FIG. 5 ) returns to the state in which the touch input processing is enabled. Then, the preparation processing for the stylus input is stopped at step S 21  and step S 11  is performed again. 
     Referring to  FIGS. 8 and 15A  to  15 D, it is determined at step S 11  whether the end  22  of the position pointing device  2  is inside of the first detection range d 1 . If the end  22  of the position pointing device  2  is determined to be inside of the first detection range d 1  as represented by a “YES” at step S 11 , then step S 14  is performed. At step S 14 , the touch processing is inhibited (i.e., disabled). Next, step S 12  is performed, in which preparation processing to enable the stylus input processing is performed. 
     At step S 13 , it is determined whether the end  22  of the position pointing device  2  is inside of the second detection range d 2 . If the end  22  of the position pointing device  2  is determined to be inside of the second detection range d 2  as represented by a “YES” at step S 13 , then step S 15  is performed. At step S 15 , detection data from the stylus input is supplied to the input unit  45  and display control based on the detection data is performed. Then, step S 16  is performed in which display control based on the distance of the end  22  of the position pointing device  2  from the display panel  13 ′ and the stylus pressure is performed. A remainder of the method of  FIG. 8  may be similar to the flowchart shown in  FIG. 7 . 
     In the present embodiment of the invention, the method shown in  FIG. 9  and the method shown in  FIG. 10  can be applied at the step S 16  in the flowcharts of  FIGS. 7 and 8  in the same manner as applied above to previous embodiments. 
     Also, the methods shown in  FIGS. 11 and 12  can be applied when the touch input is being detected in  FIG. 11  and when the stylus input is being detected in  FIG. 12 . 
     It should be noted that while the position pointing device  2  points the position by transmitting and receiving the wireless signal between it and the second sense unit  32 ′, the present invention is not limited thereto. For example, the position pointing device  2  may include a built-in power supply so that the position pointing device  2  may transmit a signal to the second sense unit  32 ′ in a one-way fashion. 
     It should be understood that while the first sense unit  31 ′ of the electrostatic capacity position detection is located on the surface of the display panel  13 ′, and the second sense unit  32 ′ of the electromagnetic position detection is located at the back side of the display panel  13 ′ as shown in  FIG. 14 , the present invention is not intended to be limited to this arrangement. The first and second sense units  31 ′ and  32 ′ may be located on the surface of the display panel  13 ′, respectively. In this case, both of the first and second sense units  31 ′ and  32 ′ may be combined together. 
       FIG. 16  illustrates an arrangement in which a combined sense unit  70  is located on the surface of the display panel  13 ′. As shown in  FIG. 16 , the combined sense unit  70  includes a transparent substrate which covers the surface of the display panel  13 ′, a plurality of X-axis coil units  71  formed of transparent electrodes, and a plurality of electrostatic capacitance sensors  73  formed of transparent electrodes disposed on the surface of the transparent substrate. 
     The X-axis coil units  71  and the electrostatic capacitance sensors  73  may be disposed in an alternating manner on the surface of the transparent substrate. The X-axis coil units  71  and the electrostatic capacity sensors  73  are each formed of an elongated transparent electrode so as not to hinder display on the display panel  13 ′. 
     A plurality of Y-axis coil units  72  is disposed at a back side of the transparent substrate of the combined sense unit  70 . The Y-axis coil units  72  may be perpendicular to the X-axis coil units  71 . The Y-axis coil units  72  may also be formed of elongated transparent electrodes. 
     The X-axis coil unit  71  and the Y-axis coil unit  72  correspond to the loop coils  322  and  324  shown in  FIG. 5 , respectively, and are connected to a circuit having an arrangement similar to that shown in  FIG. 5  to detect a position of the position pointing device  2 . 
     According to the arrangement shown in  FIG. 16 , since the combined sense unit  70  is disposed on the surface of the display panel  13 ′ and executes two detection operations, it is possible to simplify the structure of the system. 
     Also, when the combined sense unit  70  is in use, a first sense unit for the electrostatic capacitance position detection and a second sense unit for the electromagnetic position detection can use a common sensing unit. That is, the first sense unit can detect whether the surface is directly touched with a finger and the second sense unit can detect an approach and/or contact by the position pointing device  2  using the same coil disposed on the surface of the display panel  13 ′. 
     More specifically, the same coil may be alternately connected to a first sense unit detection circuit and a second sense unit detection circuit in a time-sharing manner at a relatively short cycle so that the detection of whether the surface of the display panel  13 ′ is directly touched with a finger and the detection of the position pointing device  2  can be performed substantially at the same time. Then, the switching between touch input processing and stylus input processing similar to the processing described above can be performed based on the operation of the two detecting circuits. Accordingly, it is possible to further simplify the arrangement of the coils and/or electrostatic sensors of the sense unit. 
     Also, while the display panel  13 ′ is described as being a liquid-crystal display panel in the present embodiment, the present invention is not intended to be limited to this arrangement. The display panel  13 ′ may be applied to other display devices. For example, as shown in  FIG. 17 , an electronic paper  15  may be used as the display device. The electronic paper  15  is a display device which is driven only when the display is changed and which can maintain the display without application of a signal. The electronic paper  15  may be constructed by using a flexible substrate. 
     When the electronic paper  15  is in use, as shown in  FIG. 17 , a first sense unit  31 ′ is disposed on a display surface thereof and a second sense unit  32 ′ is disposed on a back side thereof. Alternatively, as shown in  FIG. 16 , a combined sense unit may be located only on the display surface of the electronic paper  15 . The circuits connected to the first sense unit  31 ′ and the second sense unit  32 ′ may have the same arrangements as those described in previous embodiments. 
     When the electronic paper  15  is constructed using the flexible substrate, the first sense unit  31 ′ and the second sense unit  32 ′ may also be constructed using the flexible substrates. 
     When the electronic paper is in use as described above, it is possible to carry out satisfactory input detection and operation. 
     Alternatively, the devices including the display apparatus can be applied to equipment other than the computer apparatus. That is, the above-mentioned first and second sense units may be disposed on the display portion (display panel) of the information processing apparatus such as a PDA (personal digital assistant), a mobile phone and a portable game machine to which the present invention can be applied. 
     The present invention may be embodied as executable code in computer readable media including storage media such as magnetic storage media (ROMs, RAMs, floppy disks, magnetic tapes, etc.), optically readable media (CD-ROMs, DVDs, etc.), and carrier waves (transmission over the Internet). For example, operation of the computer apparatus  1  (or  1 ′) and/or the control circuit  601  of the electromagnetic position detecting unit  60  may be controlled by executable code. 
     Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.