Patent Publication Number: US-2006017703-A1

Title: Input apparatus

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention generally relates to an input apparatus, and more particularly to an input apparatus for input by operating an operation unit.  
      2. Description of the Related Art  
      A conventional input apparatus, which is operated with an operation unit such as an operation lever, includes a magneto-electric transducer such as a permanent magnet and a Hall element. Here, the permanent magnet is mechanically mounted in an oscillatable manner on the magneto-electric transducer.  
      As a conventional example of a thin-sized coordinate inputting apparatus, there is a touch panel. As shown in Japanese Laid-Open Patent Application No. 61-259324, the touch panel has a pair of resistance sheets having a predetermined space therebetween, in which a contact position is detected by applying a voltage on one of the resistance sheets and measuring the electric potential of the other resistance sheet.  
      However, as described above, since the conventional input apparatus, which is operated with an operation unit such as an operation lever, has a structure where the permanent magnet is mechanically mounted in an oscillatable manner on the magneto-electric transducer, it is difficult to form the conventional input apparatus, for example, into a thin size.  
      Although the touch panel can be formed into a thin-size, the touch panel has a structure that is unsuitable for input using an operation unit such as an operation lever since the touch panel is designed for direct input with use of a finger or a pen.  
     SUMMARY OF THE INVENTION  
      It is a general object of the present invention to provide an input apparatus that substantially obviates one or more of the problems caused by the limitations and disadvantages of the related art.  
      Features and advantages of the present invention will be set forth in the description which follows, and in part will become apparent from the description and the accompanying drawings, or may be learned by practice of the invention according to the teachings provided in the description. Objects as well as other features and advantages of the present invention will be realized and attained by an input apparatus particularly pointed out in the specification in such full, clear, concise, and exact terms as to enable a person having ordinary skill in the art to practice the invention.  
      To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention provides an input apparatus including: a touch panel upper member for outputting a detection signal corresponding to an input position at which an input operation is executed; a moveable lower member disposed with respect to the touch panel upper member; an operation unit for executing the input operation; and an operation mechanism which, in accordance with the input operation of the operation unit, is operable to urge the moveable lower member into contact with the touch panel upper member at the input position to thereby transmit the input position to the touch panel upper member and output the detection signal corresponding to the input position.  
      In an input apparatus according to an embodiment of the present invention, the moveable lower member may include a flexible sheet lower member, and wherein the flexible sheet lower member is spaced from the touch panel upper member.  
      In an input apparatus according to an embodiment of the present invention, the operation mechanism may include a head part, and wherein the head part and the flexible sheet lower member may be disposed at opposite sides of the touch panel upper member.  
      In an input apparatus according to an embodiment of the present invention, the operation mechanism may be operable to urge the head part and the flexible sheet lower member towards one another to thereby urge the flexible sheet lower member into contact with the touch panel upper member.  
      In an input apparatus according to an embodiment of the present invention, the urging may be by magnetic attraction forces between the head part and the flexible sheet lower member.  
      In an input apparatus according to an embodiment of the present invention, the head part may be magnetized.  
      In an input apparatus according to an embodiment of the present invention, the head part may be disposed between the operation unit and the touch panel upper member.  
      In an input apparatus according to an embodiment of the present invention, the head part may be moveable by the operation unit along the touch panel upper member.  
      In an input apparatus according to an embodiment of the present invention, the input apparatus may further include a moving mechanism for oscillatably guiding the operation unit along a surface of the touch panel upper member.  
      In an input apparatus according to an embodiment of the present invention, the moving mechanism may be detachably attached to the touch panel upper member.  
      In an input apparatus according to an embodiment of the present invention, the head part may have a bottom face formed as a round shape.  
      In an input apparatus according to another embodiment of the present invention, the touch panel upper member and the flexible sheet lower member may form a touch panel unit, and wherein the operation mechanism may include a head part and a moveable bending member disposed at opposite sides of the touch panel unit.  
      In an input apparatus according to another embodiment of the present invention, the operation mechanism may be operable to urge the head part and moveable bending member towards one another to thereby draw the flexible sheet lower member into contact with the touch panel upper member.  
      In an input apparatus according to another embodiment of the present invention, the urging may be by magnetic attraction forces between the head part and the moveable bending member.  
      In an input apparatus according to another embodiment of the present invention, the movable bending member may be spherical in shape.  
      In an input apparatus according to another embodiment of the present invention, the head part may be magnetized.  
      In an input apparatus according to another embodiment of the present invention, the head part may be disposed between the operation unit and the touch panel upper member.  
      In an input apparatus according to another embodiment of the present invention, the head part may be moveable by the operation unit along the touch panel upper member.  
      In an input apparatus according to another embodiment of the present invention, the input apparatus may further include a moving mechanism for oscillatably guiding the operation unit along a surface of the touch panel upper member.  
      In an input apparatus according to another embodiment of the present invention, the moving mechanism may be detachably attached to the touch panel upper member.  
      In an input apparatus according to another embodiment of the present invention, the head part may have a bottom face formed as a round shape.  
      In an input apparatus according to another embodiment of the present invention, the input apparatus may further include a base plate having a recess part on which the moveable bending member is disposed.  
      In an input apparatus according to an embodiment of the present invention, the touch panel upper member and the moveable lower member may form a resistance film touch panel.  
      In an input apparatus according to an embodiment of the present invention, the touch panel upper member may include an optical touch panel.  
      Other objects and further features of the present invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a schematic diagram showing an exemplary configuration of a system according to a first embodiment of the present invention;  
       FIG. 2  is an exploded perspective diagram showing an input apparatus according to the first embodiment of the present invention;  
       FIG. 3  is a cross-sectional diagram showing an input apparatus according to the first embodiment of the present invention;  
       FIG. 4  is an exploded perspective diagram showing a touch panel according to the first embodiment of the present invention;  
       FIG. 5  is a flowchart showing a detection process of a CPU according to the first embodiment of the present invention;  
       FIG. 6  is an exploded perspective diagram showing an input apparatus according to a second embodiment of the present invention;  
       FIG. 7  is a cross-sectional diagram showing an input apparatus according to the second embodiment of the present invention;  
       FIG. 8  is an exploded perspective diagram showing an input apparatus according to a third embodiment of the present invention;  
       FIG. 9  is a cross-sectional diagram showing an input apparatus according to the third embodiment of the present invention;  
       FIG. 10  is an exploded perspective diagram showing an input apparatus according to a fourth embodiment of the present invention;  
       FIG. 11  is a cross-sectional diagram showing an input apparatus according to the fourth embodiment of the present invention;  
       FIG. 12  is an exploded perspective diagram showing an input apparatus according to a fifth embodiment of the present invention; and  
       FIG. 13  is a cross-sectional diagram showing an input apparatus according to the fifth embodiment of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      In the following, embodiments of the present invention will be described with reference to the accompanying drawings.  
      [Information Processing System  1 ] 
       FIG. 1  is a diagram showing an exemplary structure of a system according to an embodiment of the present invention.  
      In this embodiment of the present invention, an information processing system  1  (e.g. game device or a personal computer) using an input system  11  is described.  
      The information processing system  1  includes the input system  11  and a host apparatus  12 .  
      The input system  11  generates input information in accordance with input operations (maneuvers) of an operation unit  32  (e.g. operation lever) of an input apparatus  21 , and sends the input information to the host apparatus  12 . The host apparatus  12 , in accordance with the input information sent from the input system  11 , executes a process of moving, for example, a pointer or a cursor displayed on a display apparatus.  
      [Input System  11 ] 
      The input system  11  includes the input apparatus  21  and a circuit board (printed circuit board)  22 .  
      The input apparatus  21  includes a touch panel  31  for outputting a detection signal(s) corresponding to an operation location of an operation face, the operation unit  32  for executing an input operation(s), and an operation mechanism  33  for transmitting the input operation of the operation unit  32  to a touch panel  31 . The touch panel  31 , employing, for example, a resistance film type touch panel, outputs a detection signal(s) corresponding to the input operation of the operation unit  32  and sends the detection signal(s) to the circuit board  22 . It is to be noted that the structure of the input apparatus  21  is described in more detail below.  
      A switch circuit  41 , an analog/digital converter (ADC)  42 , and a CPU  43  are mounted on the circuit board  22 .  
      The switch circuit  41  switches voltage applied to an electrode provided to the touch panel  31  in accordance with an instruction(s) from the CPU  43 .  
      The analog/digital converter  42  converts a detected signal selected by the switch circuit  41  into digital data. The digital data converted in the analog/digital converter  42  is supplied to the CPU  43 .  
      The CPU  43  includes a calculation part  51 , a clock generation part  52 , a memory part  53 , and an interface (I/F) part. The calculation part  51  performs a process of generating input information based on the data provided from the analog/digital converter  42  by using a program stored in the memory part  53 . Here, the calculation part  51  performs this process based on a clock(s) from the clock generation part  52 . The input information generated in the calculation part  51  is provided to the interface part  54 . The interface part  54 , which serves as an interface with respect to the host apparatus  12 , provides the input information to the host apparatus  12 .  
      [Input Apparatus  21 ] 
       FIG. 2  is a perspective view showing the input apparatus  21  according to an embodiment of the present invention, and  FIG. 3  is a cross-sectional view showing the input apparatus  21  according to an embodiment of the present invention.  
      The touch panel  31  is disposed on a base plate  61 . The operation unit  32  is disposed at an upper part of the touch panel  31  in an arrow Z 1  direction. In this embodiment of the present invention, a head part  142  which is disposed between the operation unit  32  and the touch panel  31  serves as the operation mechanism.  
      First, a structure of the touch panel  31  is described below.  
       FIG. 4  is an exploded perspective view showing the touch panel  31  according to an embodiment of the present invention.  
      Here, the touch panel  31  is a resistant film type touch panel having a lower substrate  121  and an upper substrate  122  stacked with a spacer  123  interposed therebetween at its periphery.  
      The lower substrate  121  is formed of a flexible film-like magnetic material having a conductive property. The lower substrate  121  is connected to the upper substrate  122  in a manner described in greater detail below. Thereby, the lower substrate  121  can bend and attach to a magnet or the like.  
      The upper substrate  122  has a configuration in which a resistance film  132 , electrodes  133 - 136 , and a wiring pattern(s)  137  are stacked on a glass substrate  131 . The resistance film  132  is made from, for example, indium tin oxide (ITO), and is formed substantially on the entire face of the glass substrate  131  facing the lower substrate  121 , that is, substantially on the entire face of the glass substrate  131  facing toward arrow direction Z 2 . The electrode  133  is made from, for example, silver (Ag), and is formed on the resistance film  132  at an edge part thereof toward arrow direction X 1  in a manner extending parallel to arrow direction Y 1 , Y 2 . The electrode  134  is made from, for example, silver (Ag), and is formed on the resistance film  132  at an edge part thereof toward arrow direction X 2  in a manner extending parallel to arrow direction Y 1 , Y 2 .  
      The electrode  135  is made from, for example, silver (Ag), and is formed on the resistance film  132  at an edge part thereof toward arrow direction Y 2  in a manner extending parallel to arrow direction X 1 , X 2 . The electrode  136  is made from, for example, silver (Ag), and is formed on the resistance film  132  at an edge part thereof toward arrow direction Y 1  in a manner extending parallel to arrow directions X 1 , X 2 .  
      The wiring patterns  137  are formed on the resistance film  132  and/or the glass substrate  131  via an insulation layer, in which one end of the wiring patterns  137  is connected to one of the electrodes  133 - 136  and a connection pad  139 , and the other end of the wiring patterns  137  is connected to one end of cable  140 . The connection pad  139  is connected to the upper substrate  121 . It is to be noted that the other end of cable  140  is connected to the circuit board  22 .  
      Next, the operation unit  32  is described.  
      The operation unit  32  includes, for example, an operation knob  141 . A moving mechanism  150  is in slidable engagement with the operation unit  32  by disposing the moving mechanism  150  between the operation knob  141  and the head part  142  and fastening the head part  142  to the operation knob  141 .  
      The operation knob  141  includes a knob part  143  and an engagement part  144 . The operation knob  141  is disposed toward arrow direction Z 1  of the moving mechanism  150 . The engagement part  144  is slidably engaged to the moving mechanism  150 .  
      The moving mechanism  150  has a first moving mechanism part  151  and a second moving mechanism part  152 .  
      The first moving mechanism part  151  includes a frame part  161  and a guide part  162 . The frame part  161 , having a rectangular shape, is provided with guiding grooves  171  and  172 . The guiding grooves  171  and  172  are formed extending parallel to arrow directions X 1 , X 2  at a lower inner peripheral part of the frame part  161  toward arrow direction Z 2 .  
      The guide part  162  is disposed between and in sliding engagement with the guide grooves  171 ,  172  in a direction parallel to arrow directions Y 1 , Y 2 . The guide part  162  is movable in arrow directions X 1 , X 2  by having both of its ends guided by the guiding grooves  171 ,  172 .  
      A guiding slot  173  is formed at a center portion of the guide member  162  along arrow directions Y 1 , Y 2 . The engagement part  144  of the operation knob  141  is slidably inserted in the guiding slot  173 . The operation knob  141  is engaged to the guiding slot  173  in a movable manner towards arrow directions Y 1  and Y 2 .  
      A second moving mechanism part  152  includes a frame part  181  and a guide part  182 . The frame part  181  is provided with guiding grooves  191  and  192 . The guiding grooves  191  and  192  are formed extending parallel to arrow directions Y 1 , Y 2  at an upper inner peripheral part of the frame part  181  toward arrow direction Z 1 .  
      The guide part  182  is disposed between and in sliding engagement with the guide grooves  191 ,  192  in a direction parallel to arrow directions X 1 , X 2 . The guide part  182  is movable in arrow directions X 1 , X 2  by having both of its ends guided by the guiding grooves  191 ,  192 .  
      A guiding slot  193  is formed at a center portion of the guide member  182  along arrow directions X 1 , X 2 . The engagement part  144  of the operation knob  141  is slidably inserted in the guiding slot  193 . The operation knob  141  is engaged to the guiding slot  193  in a movable manner towards directions X 1  and X 2 .  
      The engagement part  144  of the operation knob  141  is inserted through the guiding slots  173  and  193  from direction Z 1  to direction Z 2 . A thread hole  145  is formed in the engagement part  144 . The head part  142  is formed with a screw part  146  corresponding to the thread hole  145  of the engagement part  144 . The head part  142  is fixed to the operation knob  141  by having the screw part  146  screwed to the thread hole  145  of the engagement part  144 .  
      The head part  142 , which in the illustrated embodiment serves as the operation mechanism, is magnetized in arrow directions Z 1 , Z 2  to form a permanent magnet. The head part  142  is formed with a substantially round shape, in which its end surface projecting toward arrow direction Z 2  has a substantially rounded conical shape or a semi-spherical shape, for example.  
      By inserting the engagement part  144  of the operation knob  141  through the guiding slots  173 ,  193  and fastening the screw part  146  of the head part  142  through the threaded hole  145  of the engagement part  144 , the operation unit  32  is engaged to the moving mechanism  150  in a movable manner in directions X 1 , X 2 , Y 1 , and Y 2 . Furthermore, the first and second moving mechanisms  151 ,  152  and the touch panel  31  are fixed to a base plate  61  by inserting screws  201  through the through-holes  174 ,  194 , and  124  and fastening the screws  201  into respective thread holes  211  in the base plate  61 .  
      Thus structured, the moving mechanism  150  guides the movement of the operation unit  32  in directions X 1 , X 2 , Y 1 , Y 2  along an operation face (face facing toward direction Z 1 ) of the touch panel  31 . It is to be noted that since both the first and second moving mechanism parts  151  and  152  are employed for guiding the movement of the operation unit  32 , the operation knob  141  can be moved smoothly.  
      The first and second moving mechanism parts  151 ,  152 , and the touch panel  31  are fixed to the base plate  61  by threading the screw  201  into the thread hole  211  of the base plate  61  via the through-holes  174 ,  194 , and  124 . Thereby, the head part  142  contacts a side of the upper substrate  122  of the touch panel  31  facing toward direction Z 1 . As described above, the head part  142  is formed of a permanent magnet magnetized in directions Z 1 , Z 2 , and the lower substrate  121  of the touch panel  31  is formed of a flexible magnetic material. Therefore, when the head part  142  contacts the face of the upper substrate  122  facing toward direction Z 1 , the lower substrate  121  bends (projects) toward direction Z 1  at a portion where the head part  142  is situated, as shown in  FIG. 3 . Accordingly, the operation mechanism according to this embodiment of the present invention is formed of the head part  142 .  
      By the contact of the lower substrate  121  and the upper substrate  122 , the touch panel  31  sends a detection signal(s) corresponding to the position of the contact via the cable  140  ( FIG. 4 ).  
      In the circuit board  22 , the detection signal is converted into digital data by the analog/digital converter  42 . Then, the digital data is sent to the CPU  43 . Then, the CPU  43  executes a detection process.  
      Next, the detection process executed by the CPU  43  is described with reference to  FIG. 5 .  
      First, the CPU  43  applies a predetermined voltage between electrodes  133  and  134  of the touch panel  31  (Step S 1 - 1 ). Then, the CPU  43  detects the potential (electric potential) of the lower substrate  121  of the touch panel  31  (Step S 1 - 2 ). This potential of the lower substrate  121  is the potential corresponding to the contact position of the lower substrate  121  with respect to the upper substrate  122  in the directions X 1  and X 2 . In accordance with the detected potential, the coordinate in the directions X 1  and X 2  can be obtained.  
      Then, the CPU  43  applies a predetermined voltage between electrodes  135  and  136  (Step S 1 - 3 ). Then, the CPU  43  detects the potential of the lower substrate  121  of the touch panel  31  (Step S 1 - 4 ). This potential of the lower substrate  121  is the potential corresponding to the contact position of the lower substrate  121  with respect to the upper substrate  122  in the directions Y 1  and Y 2 . In accordance with the detected potential, the coordinate in the directions Y 1  and Y 2  can be obtained.  
      Then, the CPU  43  generates coordinate data in accordance with a signal(s) of the detected potential for the directions X 1 , X 2  obtained in Step S 1 - 2  and a signal(s) of the detected potential for the directions Y 1 , Y 2  obtained in Step S 1 - 4  (Step S 1 - 5 ). Then, the CPU  43  outputs the generated coordinate data (Step S 1 - 6 ).  
      According to the first embodiment of the present invention, since the touch panel  31  is provided to the input apparatus  21  using the operation unit  32  as the executing input, the touch panel  31  can be formed into a thin size. Furthermore, with the operation mechanism, the contact position can be accurately detected. Furthermore, by forming the bottom side of the head part  162  into a curved face such as a spherical shape (round), the contact area can be reduced for enabling position to be detected more precisely.  
      Furthermore, since the moving mechanism  150  has a detachable structure, the touch panel  31  can be removed therefrom to be used as an ordinary touch panel. Therefore, owing to the detachable structure of the moving mechanism  150 , the touch panel  31  can be used as a touch panel dedicated for the input apparatus  21  using the operation unit  32  when attached to the moving mechanism  150 . On the other hand, the touch panel  31  can be used as an ordinary touch panel when detached from the moving mechanism  150 .  
      Although an analog resistance film type touch panel is used as the touch panel  31  according to the embodiment of the present invention, a matrix resistance film type touch panel may alternatively be used. Furthermore, the touch panel  31  according to the embodiment of the present invention is not limited to a five-wire type touch panel, but other types, for example, a seven-wire type or an eight-wire type, may alternatively be employed. As will be appreciated, the touch panel  31  is not to be limited based on the type (method) of detection.  
      Although the lower substrate  121  of the touch panel  31  according to the embodiment of the present invention is formed of a flexible sheet-like magnetic material, a flexible magnetic sheet may alternatively be disposed under the lower substrate  121  of the touch panel for enabling the flexible magnetic sheet under the lower substrate  121  to bend the lower substrate of the touch panel when contact is made with the head part for executing position detection.  
     Second Embodiment  
       FIG. 6  is an exploded perspective view of an input apparatus  300  according to a second embodiment of the present invention.  FIG. 7  is a cross-sectional view of the input apparatus  300  according to the second embodiment of the present invention. In these drawings, like components are denoted by like numerals as of  FIGS. 2 and 3  in the first embodiment of the present invention, and will not be further explained.  
      The input apparatus  300  according to the second embodiment of the present invention includes a touch panel  311  and a flexible sheet-like magnetic material  312  and has a configuration which is different from the input apparatus  21  according to the first embodiment of the present invention. The touch panel  311  has a lower substrate  321  provided with a structure similar to that of a typical resistance film type touch panel. The lower substrate  321  includes a conductive film  332  formed on a resin sheet  331 . The flexible magnetic sheet  312  is disposed between a base plate  61  and the touch panel  311 .  
      In the input apparatus  300  according to the second embodiment of the present invention, a portion of the flexible magnetic sheet  312  is attracted to a head part  142  via the touch panel  311 . Here, the portion of the flexible magnetic sheet  312  bends (projects), and urges the lower substrate  321  toward direction Z 1 , to thereby force the lower substrate  321  to contact the upper substrate  122 .  
      In the operation mechanism  33  described in the first and second embodiments of the present invention, although a flexible magnetic sheet is provided as the lower substrate  121  or as the flexible magnetic sheet  312  disposed under the touch panel  311 , other magnetic materials (magnetic members) may alternatively be employed for magnetic attraction to the head part  142  of the operation unit  32 .  
     Third Embodiment  
       FIG. 8  is an exploded perspective view of an input apparatus  400  according to the third embodiment of the present invention.  FIG. 9  is a cross-sectional view of the input apparatus  400  according to the third embodiment of the present invention. In these drawings, like components are denoted by like numerals as of  FIGS. 2, 3 ,  6 , and  7  in the first and second embodiments of the present invention, and will not be further explained.  
      The input apparatus  400  has a base plate  411  that is different from that of the input apparatus  21  in the first embodiment of the present invention.  
      As shown in the cross-sectional view in  FIG. 9 , the base plate  411  is formed with a recess part  421 . A magnetic spherical member  412  is provided in the recess part  421  of the base plate  411 . It is to be noted that the diameter of the magnetic spherical member  412  is substantially equal to the depth of the recess part  421  in the base plate  411 .  
      Similar to the touch panel  311  of the second embodiment of the present invention, the lower substrate  321  includes the conductive film  332  formed on the resin sheet  331  (i.e. on a plane of the resin sheet facing the upper substrate  122 ). In the operation unit  413  according to the third embodiment of the present invention, the illustrated exemplary head part  431  has a bottom end plane (toward direction Z 2 ) that is flat ( FIG. 9 ).  
      With the input apparatus  400  according to the third embodiment of the present invention, the magnetic spherical member  412  is attracted to the head part  431  via the touch panel  311 . Here, the magnetic spherical member  412  forces a portion of the lower substrate  321  to bend (project), to thereby enable the portion of the lower substrate  321  to contact the upper substrate  122 . Furthermore, when the operation unit  413  is moved, the magnetic spherical member  412  correspondingly follows the movement of the operation unit  413 . Here, since the magnetic spherical member  412  has a spherical shape, the magnetic spherical member  412  can rollingly move, thereby providing a smooth movement.  
      In the input apparatus  400  according to the third embodiment of the present invention, the magnetic spherical member  412  can be firmly attracted to the head part  431  by forming the bottom end plane (toward direction Z 2 ) of the head part  431  as a flat plane. Furthermore, the contact area with respect to the touch panel  311  can be small by employing a magnetic spherical member  412  to be attracted to the head part  431 . Thereby position detection can be executed with more precision.  
     Fourth Embodiment  
       FIG. 10  is an exploded perspective view of an input apparatus  500  according to a fourth embodiment of the present invention.  FIG. 11  is a cross-sectional view of the input apparatus  500  according to the fourth embodiment of the present invention. In these drawings, like components are denoted by like numerals as of  FIGS. 2 and 3  in the first embodiment of the present invention, and will not be further explained.  
      In the input apparatus  500 , an optical touch panel  541  is employed as the touch panel. As shown in the cross-sectional view in  FIG. 11 , a base plate  511  has a recess part  525 . Here, each side of the recess part  525  is provided with notch parts  521 - 524 . A flexible magnetic sheet  531  is installed in the recess part  525  of the base plate  511 . It is to be noted that the flexible magnetic sheet  531  is formed with a shape which is substantially the same as that of the bottom face of the recess part  525  of the base plate  511 . Furthermore, the touch panel  541  (dividing plane) is fixed to a top plane (plane facing direction Z 1 ) of the base plate  511 .  
      An illumination unit  551  is attached to the notch part  521  of the base plate  511 . The illumination unit  551  has, for example, illumination elements arranged in directions Y 1 , Y 2  for irradiating light toward an inner side (toward direction X 2 ) of the recess part  525 .  
      A light receiving unit  561  is attached to the notch part  522  of the base plate  511 . The light receiving unit  561  has, for example, light receiving elements arranged in directions Y 1 , Y 2  for detecting light from an inner side (from direction X 1 ) of the recess part  525 .  
      An illumination unit  552  is attached to the notch part  523  of the base plate  511 . The illumination unit  552  has, for example, illumination elements arranged in directions X 1 , X 2  for irradiating light toward an inner side (toward arrow direction Y 2 ) of the recess part  525 .  
      A light receiving unit  562  is attached to the notch part  524  of the base plate  511 . The light receiving unit  562  has, for example, light receiving elements arranged in arrow directions X 1 , X 2  for detecting light from an inner side (from arrow direction Y 1 ) of the recess part  525 .  
      As shown in  FIG. 11 , a portion of the flexible sheet-like magnetic material  531  is attracted to the head part  142  via the touch panel  541 . The portion of the flexible sheet-like magnetic material  531  bends (projects) as the flexible sheet-like magnetic material  531  is attracted to the head part  142  via the touch panel  541 . The light irradiated from the illumination units  551 ,  552  to the light receiving units  561 ,  562  is blocked at the projecting portion of the flexible sheet-like magnetic material  531 . Accordingly, the position of the operation unit  32  can be detected by detecting the location where the light is blocked.  
      It is to be noted that although the flexible sheet-like magnetic material  531  is employed for the above-described position detection, other magnetic materials (magnetic members) may alternatively be employed for magnetic attraction towards to the head part  142 .  
     Fifth Embodiment  
       FIG. 12  is an exploded perspective view showing an input apparatus  600  according to a fifth embodiment of the present invention.  FIG. 13  is a cross-sectional view showing an input apparatus  600  of the fifth embodiment of the present invention. In these drawings, like components are denoted by like numerals as of  FIGS. 10 and 11  in the fourth embodiment of the present invention, and will not be further explained.  
      In the fifth embodiment, a magnetic spherical member(s)  611  is alternatively provided in the recess part  525  of the base plate  511 . It is to be noted that the magnetic spherical member  611  has a diameter that is substantially equal to the depth of the recess part  525 .  
      As shown in  FIG. 13 , the magnetic spherical member  611  is attracted to the head part  142  having the touch panel  541  situated therebetween. The light irradiated from the illumination units  551 ,  552  to the light receiving units  561 ,  562  is blocked at a position where the magnetic spherical member  611  is attracted. Accordingly, the position of the head part  142  can be detected by detecting the location where the light is blocked.  
      In the above-described embodiments, although a resistance film type touch panel and an optical type touch panel are employed as the touch panel, other types of touch panels may alternatively be employed (e.g. electrostatic capacity method touch panel, ultrasonic touch panel). Furthermore, although a glass substrate is employed as the upper substrate of the resistance film touch panel, a resin film may alternatively be employed.  
      Further, the present invention is not limited to these embodiments, but various variations and modifications may be made without departing from the scope of the present invention.  
      The present application is based on Japanese Priority Application No. 2004-216104 filed on Jul. 23, 2004, with the Japanese Patent Office, the entire contents of which are hereby incorporated by reference.