Patent Publication Number: US-2022216868-A1

Title: Input device and input system

Description:
TECHNICAL FIELD 
     The present disclosure relates to an input device used to input an operation to various electronic equipment, and to an input system including the input device. 
     BACKGROUND ART 
     PTL 1 discloses a conventional input device including a pressure sensor. The input device includes an elastic body and the pressure sensor disposed inside the elastic body. An operator presses the elastic body with a finger, which is an operation body, to cause the elastic body to elastically deform. The input device detects the elastic deformation of the elastic body by the pressure sensor, and outputs a result of detection as an electric signal. 
     The input devices may include a movable electrode and a fixed electrode provided inside the pressure sensor. In this case, a capacitance is formed between the movable electrode and the fixed electrode. The displacement of the movable electrode in response to the pressing by a finger changes the capacitance. An electric signal containing the change in the capacitance is output from the fixed electrode. The pressure sensor senses the pressing by the finger based on the electric signal output from the fixed electrode. 
     CITATION LIST 
     Patent Literature 
     PTL 1: Japanese Patent Laid-Open Publication No. 2012-004129 
     SUMMARY 
     An input device includes a detection surface configured to be operated by an operation body, a first fixed electrode, a movable electrode, first and second terminals configured to be connected to an outside of the input device, and a direct-connection line electrically connecting the movable electrode to the second terminal via no capacitor. The movable electrode has a lower surface facing an upper surface of the first fixed electrode to be capacitively coupled to the first fixed electrode. The movable contact is displaceable to approach the first fixed electrode in response to a pressing of the detection surface by the operation body. The first terminal is configured to output, to the outside of the input device, a first electric signal containing a change in a capacitance between the first fixed electrode and the movable electrode. The second terminal is configured to output, from the movable electrode to the outside of the input device, a second electric signal containing a change in a capacitance between the operation body and the movable electrode. 
     This input device improves the detection sensitivity to detect approximating or contacting the input device by the operation body. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of an input device according to an exemplary embodiment. 
         FIG. 2  is a schematic block diagram of an input system according to the embodiment. 
         FIG. 3  is an exploded perspective view of the input device according to the embodiment. 
         FIG. 4  is a plan view of a fixed electrode of the input device according to the embodiment. 
         FIG. 5  is a schematic sectional view of the input device along line A 1 -A 1  shown in  FIG. 1 . 
         FIG. 6  is a schematic sectional view of the input device along line A 2 -A 2  shown in  FIG. 1 . 
         FIG. 7A  is a schematic sectional view of the input device along line A 3 -A 3  shown in  FIG. 1 . 
         FIG. 7B  is a schematic sectional view of the input device along the line A 3 -A 3  shown in  FIG. 1 . 
         FIG. 8A  schematically illustrates an operation of a proximity-detection process of the input system according to the embodiment. 
         FIG. 8B  schematically illustrates another operation of the proximity-detection process of the input system according to the embodiment. 
         FIG. 9A  schematically illustrates an operation of a pressure-detection process of the input system according to the embodiment. 
         FIG. 9B  schematically illustrates another operation of the pressure-detection process of the input system according to the embodiment. 
         FIG. 9C  schematically illustrates still another operation of the pressure-detection process of the input system according to the embodiment. 
         FIG. 10A  schematically illustrates a manipulation of the operation body on the input device according to the embodiment. 
         FIG. 10B  schematically illustrates another manipulation of the operation body on the input device according to the embodiment. 
         FIG. 10C  schematically illustrates still another manipulation of the operation body on the input device according to the embodiment. 
         FIG. 10D  schematically illustrates a further manipulation of the operation body on the input device according to the embodiment. 
         FIG. 11  is a plan view of a fixed electrode of an input device according to Modification 1 of the embodiment. 
         FIG. 12A  is a plan view of a fixed electrode of an input device according to Modification 2 of the embodiment. 
         FIG. 12B  schematically illustrates an operation of the input device according to Modification 2 of the embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Each of the figures explained in the following exemplary embodiment is schematically drawn. Therefore, the ratio of the size and thickness of each component in each Figure does not necessarily reflect the actual dimensional ratio. 
     (1) Entire Structure 
     An entire structure of input device  1  and input system  100  according to an exemplary embodiment will be described below.  FIG. 1  is a perspective view of input device  1 .  FIG. 2  is a schematic block diagram of input system  100 . 
     Input system  100  includes input device  1  and detection circuit  9 , as shown in  FIGS. 1 and 2 . 
     Input system  100  is applicable to various electronic equipment. Input system  100  is configured to receive an operation made by operation body U 1 , determine a manipulation input by operation body U 1 , and output a result of the determination to an outside of the input device, e.g., a circuit module inside the electronic equipment having input system  100  installed therein. T manipulation input by operation body U 1  include, for example, the pressing of detection surface S 0  of input device  1  by operation body U 1 , approximating and contacting of detection surface S 0  by operation body U 1 . 
     The approximating means that operation body U 1  approximating detection surface S 0  without contacting detection surface S 0 . The contacting means that operation body U 1  contacts detection surface S 0  without causing detection surface S 0  to elastically deform. The pressing means that operation body U 1  presses detection surface S 0  to cause detection surface S 0  to elastically deform. 
     Detection surface S 0  of input device  1  is directed in upward direction Du in  FIG. 1 , an actual direction of detection surface S 0  may not necessarily be this direction. Operation body U 1  is, for example, a human fingertip (a part of a living body), operation body U 1  may not be limited to the human fingertip. Operation body U 1  may include a part of a living body and a device, such as a glove, covering the part of the living body. Operation body U 1  may include a device, such as a pen-type manipulator, held by a living body. Input device  1  may not only be directly pressed or touched by operation body U 1 , but also be indirectly pressed or touched by operation body U 1  via an operation plate disposed above detection surface S 0 . 
     Input device  1  accepts an operation input by operation body U 1  and outputs an electric signal corresponding to the input operation to an outside, such as detection circuit  9 , of input device  1 . Input device  1  may be held in a housing of electronic equipment. 
     Detection circuit  9  is configured to determine a manipulation of an operation input by operation body U 1  to input device  1  based on the electric signal output from input device  1 , and to output a result of the determination to an outside of input system  100 , such as a circuit module in the electronic equipment. Detection circuit  9  may be enclosed inside the housing of the electronic equipment. 
     (2) Input Device 
       FIG. 3  is an exploded perspective view of input device  1 . As shown in  FIG. 3 , input device  1  includes pressure-sensitive part  2 , one or more detection parts  5 , housing  10 , and push member  13 . The number of detection parts  5  is two as an example. 
     (2.1) Housing 
     Housing  10  of input device  1  constitutes an outer shell accommodating pressure-sensitive part  2 , two detection parts  5 , and push member  13  therein, as shown in  FIGS. 1 and 3 . Housing  10  includes cover  11  and body  12 . Body  12  has a box shape having, for example, a flat rectangular shape (e.g., a square shape). Openings  121   p  and  122   p  are provided in upper surface  120  of body  12 . Cover  11  is made of a film having, for example, a rectangular shape (e.g., a square shape). Cover  11  is mounted onto upper surface  120  of body  12  so as to cover openings  121   p  and  122   p  of body  12 . 
     Cover  11  and body  12  have an electrical insulation property. Cover  11  and body  12  may be made of, for example, resin material having an electrical insulation property. Particularly, cover  11  is flexible, consequently allowing operation body U 1  (refer to  FIG. 1 ) to press, via cover  11 , pressure-sensitive part  2  accommodated in housing  10 . 
     Pressure-sensitive part  2  and two detection parts  5  are provided on a lower surface of cover  11 . The upper surface of cover  11  opposite to the lower surface thereof constitutes detection surface S 0  of input device  1 . A region of detection surface S 0  of input device  1  positioned above pressure-sensitive part  2  to correspond to pressure-sensitive part  2  will be referred to as detection surface S 1 , and two respective regions of detection surface S 0  that are positioned above two detection parts  5  to correspond to two detection parts  5  will be referred to as detection surfaces S 2  below. Detection surfaces S 1  and S 2  are virtually denoted by dashed-dotted lines in  FIG. 3 . 
     Detection surface S 0  may have, for example, substantially a rectangular shape. Detection surface S 0  is a convex surface slightly protruding in upward direction Du, or in a direction away from pressure-sensitive part  2 . Detection surface S 1  may be, for example, substantially a square region. Detection surface S 1  is positioned at the center of detection surface S 0  in a longitudinal direction of detection surface S 0 . Detection surface S 1  has a circular flat region at the center of detection surface S 1 . Push member  13  is stably positioned on the lower surface of cover  11  at a position at the center of detection surface S 1 . Each of two detection surfaces S 2  is a region having substantially a rectangular shape. Two detection surfaces S 2  are positioned at both sides of detection surface S 1  in the longitudinal direction of detection surface S 0 , respectively. 
     Accommodating recess  121  opened at opening  121   p  and two accommodating recesses  122  respectively opened at openings  122   p  are provided in upper surface  120  of body  12 . Accommodating recess  121  accommodates pressure detection part  2  therein. Each of two accommodating recesses  122  accommodates a corresponding one of two detection parts  5 , therein. 
     Accommodating recess  121  and two accommodating recesses  122  are arranged in the order of one accommodating recess  122 , accommodating recess  121  and the other accommodating recess  122  in the longitudinal direction of housing  10 . Detection parts  5  is arranged adjacent to detection part  2  in housing  10  when viewed from above detection part  2 , or from above pressing surface  30 . Two detection parts  5  are disposed at both sides of pressure-sensitive part  2  so that pressure-sensitive part  2  is positioned between two detection parts  5  when viewed from above pressure-sensitive part  2 . 
     Depths of two accommodating recesses  122  are identical to each other. The depth of accommodating recess  121  is larger than the depths of two accommodating recesses  122 . Body  12  has five openings K 1 -K 5  therein. Openings K 1 -K 3  are provided in side surface  12   a  of body  12 . Openings K 4  and K 5  are provided in side surface  12   b  of body  12  opposite to side surface  12   a . Side surfaces  12   a  and  12   b  are a pair of side surfaces extending in the longitudinal direction of body  12 . Respective terminals  51 ,  711 ,  721  and  731  of fixed electrodes  50 ,  71 ,  72  and  73  are lead out from the inside to the outside of body  12  through openings K 1 -K 5 . 
     (2.2) Pressure-Sensitive Part Pressure-sensitive part  2  is configured to sense a pressure applied by operation body U 1  to detection surface S 1  in detection surface S 0  of input device  1 , as shown in  FIGS. 1 and 3 . Pressure-sensitive part  2  includes click part  3 , pressure sensor  4 , and direct-connection line TD 1 . Pressure sensor  4  is a capacitive sensor. Pressure sensor  4  is configured to output an analog electric signal containing a change in a capacitance generated between movable electrode  6  and fixed electrode  7 . Pressure sensor  4  is disposed opposite to pressing surface  30  of click part  3  (below click part  3  in  FIG. 3 ). Specifically, pressure sensor  4  includes movable electrode  6 , elastic body  14 , insulator  15 , and fixed electrode  7 . Insulator  15  has a sheet shape. Movable electrode  6 , elastic body  14 , insulator  15 , and fixed electrode  7  are arranged in this order in a direction away from click part  3 . Movable electrode  6  is closest to click part  3  among the components of pressure sensor  4 . 
       FIG. 4  is a plan view of fixed electrode  7 .  FIG. 5  is a schematic sectional view of input device  1  along line A 1 -A 1  shown in  FIG. 1 . Movable electrode  6  is movable (displaceable) with respect to fixed electrode  7  in downward direction Dd (upward and downward directions D 1 , or a displacing direction) by pressing detection surface S 0  of input device  1  in downward direction Dd with operation body U 1 . In accordance with the embodiment, movable electrode  6  is movable in its thickness direction, or upward direction Du (downward direction Dd), or in the thickness direction of housing  10 . In other words, each of upward and downward directions D 1  is the thickness direction of movable electrode  6 . Movable electrode  6  moves against the elastic force of elastic body  14  in downward direction Dd toward fixed electrode  7  by the above-mentioned pressing operation. After that, when the above-mentioned pressing operation is released, Movable electrode  6  is displaced in upward direction Du toward click part  3  by the elastic force of elastic body  14  to return to the original position. 
     Movable electrode  6  is made of an electric, conductive material, such as a metal plate, having a rectangular plate shape. Hole  61  passes through the center of movable electrode  6  in the thickness direction, or in upward and downward directions D 1 . Hole  61  has a substantially circular shape and is opened as viewed from above movable electrode  6 . 
     Fixed electrode  7  is made of electrically-conductive material, such as gold, and has substantially a rectangular flat plate shape as a whole. Fixed electrode  7  in accordance with the embodiment is divided to three pieces: fixed electrodes  71 ,  72  and  73 . In other words, fixed electrodes  71 ,  72  and  73  face movable electrode  6  across elastic body  14  and insulator  15 . Fixed electrodes  71 ,  72  and  73  are substantially flush with the same plane. Fixed electrode  7 , i.e., each of fixed electrodes  71 ,  72  and  73 , is fixed onto a bottom surface of accommodating recess  121  of body  12 . 
     Fixed electrode  7  may be regarded as that fixed electrode  7  is divided to two divisional pieces: fixed electrodes  71  and  74 , and that fixed electrode  74  is further divided to two divisional pieces: fixed electrodes  72  and  73  (see  FIG. 4 ). In other words, fixed electrode  7  includes fixed electrodes  71  and  74  which are divisional pieces of fixed electrode  7 . Fixed electrode  74  which itself is a divisional piece of fixed electrode  7  is composed of fixed electrodes  72  and  73  which are divisional pieces. 
     Fixed electrode  71  has substantially a rectangular plate shape. Fixed electrode  71  in ludes main body  712  and terminal  711  which is an output part. Main body  712  has substantially a rectangular plate shape. Main body  712  has semi-circular cutout  712   c  in the center of an edge thereof facing fixed electrode  72 . Terminal  711  is an output part outputting analog electric signal SG 1  containing a change in a capacitance between movable electrode  6  and fixed electrode  71  to an outside of input device  1 . Terminal  711  is provided at an edge of main body  712  which is opposite to the edge of main body  712  having the cutout provided therein, and projects from main body  712  substantially in a direction away from fixed electrode  72 . 
     Fixed electrode  71  is disposed in accommodating recess  121  of body  12 . In detail, main body  712  is disposed on the bottom surface of accommodating recess  121  so that almost only the upper surface out of the surfaces of main body  712  is exposed from the bottom surface of accommodating recess  121 . Terminal  711  projects from body  12  through opening K 2  provided in side surface  12   a  of body  12 . 
     Fixed electrodes  71  and  72  are arranged, for example, in a width direction perpendicular to the longitudinal direction and the thickness direction (upward and downward directions D 1 ) of housing  10 . This arranging direction is perpendicular to both the thickness direction of housing  10  and the direction in which pressure-sensitive part  2  and detection parts  5  are arranged. 
     Fixed electrode  72  has substantially a rectangular plate shape. Fixed electrode  72  has main body  723 , tongue  722 , and terminal  721  which is an output part. The length of main body  723  in the longitudinal direction of housing  10  is shorter than the length of main body  712  of fixed electrode  71  in the longitudinal direction of housing  10 . Semi-circular cutout  723   c  is provided in an edge of main body  723  facing fixed electrode  71 . Cutout  723   c  of main body  723  faces cutout  712   c  of main body  712  of fixed electrode  71  so that cutouts  712   c  and  723   c  form substantially a circular shape as a whole. Terminal  721  is an output part outputting analog electric signal SG 2  containing a change in a capacitance between movable electrode  6  and fixed electrode  72  to the outside of input device  1 . Terminal  721  is provided at an edge of main body  723  opposite to the edge of main body  723  having cutout  723   c  provided therein. Terminal  721  projects from main body  723  substantially in a direction away from fixed electrode  71 . 
     Tongue  722  is connected to main body  723  at cutout  723   c  of fixed electrode  72 , and projects toward fixed electrode  71  when viewed from above. Tongue  722  has substantially a circular plate shape. The position of tongue  722  in the thickness direction of movable electrode  6  (upward and downward directions D 1 ) is different from the position of the rectangular main body  723  of fixed electrode  72  in the thickness direction. That is, when viewed in a direction perpendicular to upward and downward directions D 1 , the position of tongue  722  deviates from the position of main body  723  of fixed electrode  72  along upward and downward directions D 1 . Tongue  722  is slightly bent to extend in the direction approaching click part  3  and further extend parallel to the upper surface of main body  723 . A surface of tongue  722  is positioned substantially within hole  61  of movable electrode  6  (see  FIG. 4 ). Apex portion  311  of dome body  31  of click part  3  contacts tongue  722  through insulator  15  (see  FIG. 3 ). 
     Fixed electrode  72  is disposed on the bottom surface of accommodating recess  121 . In detail, main body  723  and tongue  722  are disposed on the bottom surface of accommodating recess  121 . Only the upper surfaces of main body  723  and tongue  722  out of the surfaces of main body  723  and tongue  722  are exposed from the bottom surface of accommodating recess  121 . Terminal  721  projects to the outside of body  12  from opening K 4  provided in side surface  12   b  of body  12 . 
     Fixed electrode  73  has substantially a rectangular plate shape. Fixed electrode  73  includes main body  732  and terminal  731 . Main body  732  has substantially a rectangular plate shape. The length of main body  732  in the longitudinal direction of housing  10  is smaller than the length of main body  712  of fixed electrode  71  in the same direction. The width of main body  732  in the width direction perpendicular to both the longitudinal direction and the thickness direction (upward and downward directions D 1 ) of housing  10  is substantially identical to the width of main body  723  of fixed electrode  72  in the width direction. Terminal  731  is an output part outputting analog electric signal SG 3  containing a change in a capacitance between movable electrode  6  and operation body U 1  to the outside of input device  1 . Terminal  731  projects d from main body  732  substantially in a direction away from fixed electrode  71 . 
     Fixed electrode  73  is disposed on the bottom surface of accommodating recess  121 . In detail, main body  732  is disposed on the bottom surface of accommodating recess  121 . Almost only the upper surface of main body  732  out of the surfaces of main body  732  is exposed from the bottom surface of accommodating recess  121 . Terminal  731  projects to the outside of body  12  from opening K 5  provided in side surface  12   b  of body  12 . 
     In accordance with the embodiment, as shown in  FIG. 4 , the entire shape composed of main bodies  723  and  732  of fixed electrodes  72  and  73  in plan view is plane symmetrical to the shape of main body  712  of fixed electrode  71  in plan view with respect to virtual plane PL that is positioned between fixed electrode  71  and each of fixed electrodes  72  and  73  and that extends in both the longitudinal direction and the thickness direction (upward and downward directions D 1 ). 
     Elastic body  14  has, for example, a rectangular sheet shape, as shown in  FIG. 3 . Elastic body  14  has electrical conductivity. Elastic body  14  may be made of, for example, an electrically-conductive rubber sheet. Elastic body  14  has hole  140  provided therein at the center thereof and passing through elastic boy  14  penetrating in the thickness direction. Hole  140  has substantially a circular shape and opens when viewed from upper surface  141  of elastic body  14 . The outer shape of elastic body  14  is substantially identical to the outer shape of movable electrode  6 . The thickness of elastic body  14  is substantially identical to the thickness of movable electrode  6 . The diameter of hole  140  is almost identical to the diameter of hole  61  of movable electrode  6 . Upper surface  141  of elastic body  14  substantially surface-contacts lower surface of movable electrode  6 . 
     Insulator  15  is made of insulative (dielectric) material, and has, for example, a rectangular sheet shape, as shown in  FIG. 3 . The outer shape of insulator  15  is almost identical to the outer shape of movable electrode  6 . Insulator  15  has cutout  151  therein. Cutout  151  is provided at one of the four corners of the rectangular shape of the insulator. Cutout  151  is provided at a position corresponding to main body  732  of fixed electrode  73 , or above main body  732 . The shape of cutout  151  is almost identical to the shape of main body  732 , and has, e.g. substantially a rectangular shape. In accordance with the embodiment, the thickness of insulator  15  is smaller than the thickness of movable electrode  6 . 
     Insulator  15  is separated to central portion  15   a  and main body  15   b . Central portion  15   a  overlaps tongue  722  of fixed electrode  7 , and has, for example, a circular shape. Central portion  15   a  separated from main body  15   b  is easy disposed along the shape of the upper surface of tongue  722 . Insulator  15  includes central portion  15   a  in accordance with the embodiment, insulator  165  may not necessarily include central portion  15   a.    
     Insulator  15  is disposed between movable electrode  6  and fixed electrode  7 . Insulator  15  covers the upper surface of main body  712  of fixed electrode  71  and the upper surfaces of main body  723  and tongue  722  of fixed electrode  72  which are surfaces exposed from the bottom surface of accommodating recess  121 . The upper surface of main body  732  of fixed electrode  73  exposed from the bottom surface of accommodating recess  121  is exposed from cutout  151  provided in insulator  15 . This configuration allows elastic body  14  to electrically contact fixed electrode  73  through cutout  151  of insulator  15 , thus allowing movable electrode  6  to electrically contact fixed electrode  73  elastic body  14  via no capacitor. 
     In order to allow elastic body  14  electrically contact fixed electrode  73  securely, elastic body  14  may include a projection projecting toward fixed electrode  73  from a portion of elastic body  14  contacting fixed electrode  73 . Fixed electrode  73  may include a projection projecting toward elastic body  14  from a portion of fixed electrode  73  contacting elastic body  14 . Even in the case that a gap corresponding to the thickness of insulator  15  is produced between elastic body  14  and the fixed electrode, the above-described projection allows elastic body  14  to electrically and securely contact fixed electrode  73 . 
     Click part  3  has pressing surface  30  which is an upper surface thereof, and is configured to provide operation body U 1  that presses pressing surface  30  with a click feeling of touch. Click part  3  deforms elastically. Click part  3  includes dome body  31  made of a dome-shaped plate having an upper surface constituting pressing surface  30 . Dome body  31  is made of an elastic material, such as a metal plate. Dome body  31  is a so-called metal dome. 
     Pressing surface  30  of click part  3  is a convex surface. Pressing force P 1  applied by operation body U 1  to pressing surface  30  causes click part  3  to elastically deform and generate a click feeling. In detail, this elastic deformation causes the central portion of dome body  31  to be reversed from the convex shape to a concave shape (buckling). When the pressing force is applied to pressing surface  30 , click part  3  reacts to have pressing surface  30  elastically deform to sag downward to provide operation body U 1  with the click feeling. 
     Dome body  31  includes circumferential portion  310  and apex portion  311 , as shown in  FIG. 3 . Dome body  31  is disposed on the upper surface of movable electrode  6  of pressure sensor  4 . 
     In response to the pressing of dome body  31  by operation body U 1 , circumferential portion  310  of dome body  31  presses movable electrode  6  toward fixed electrode  7 . In other words, movable electrode  6  receiving the pressing force through dome body  31  moves in downward direction Dd to approach fixed electrode  7  while pressing elastic body  14  and insulator  15 . When dome body  31  is buckled in response to the pressing force from operation body U 1 , apex portion  311  moves through hole  61  of movable electrode  6  to approach tongue  722  of fixed electrode  7  and contact a portion of insulator  15  located above tongue  722  to press tongue  722  in downward direction Dd. In other words, apex portion  311  presses tongue  722  via insulator  15 . 
     Push member  13  is configured to cause click part  3  to elastically deform easily. Push member  13  has a disk shape, as shown in  FIG. 3 . The outer shape of push member  13  is smaller than the outer shape of click part  3 . Push member  13  is disposed between apex portion  311  of dome body  31  and cover  11  (see  FIG. 5 ). Push member  13  may be fixed to cover  11  or click part  3 . Push member  13  is preferably fixed to cover  11 . Push member  13  has an electrical insulation property. 
     Direct-connection line TD 1  electrically connects movable electrode  6  to terminal  731  via no capacitor to electrically connect movable electrode  6  to detection circuit  9  via no capacitor. Direct-connection line TD 1  outputs analog electric signal SG 3  from movable electrode  6  to detection circuit  9 . Direct-connection line TD 1  includes elastic body  14  and a part of fixed electrode  73 , i.e., main body  732  and terminal  731 . 
       FIG. 6  is a sectional view of input device  1  along line A 2 -A 2  shown in  FIG. 1 . In pressure-sensitive part  2 , as shown in  FIG. 6 , movable electrode  6  always electrically contacts fixed electrode  73  via electrically conductive elastic body  14  regardless of whether or not operation body U 1  provides detection surface S 0  of input device  1  with a manipulation. Electric signal SG 3  containing a change in the electric potential of movable electrode  6  is transferred consecutively from movable electrode  6  to direct-connection line TD 1  (elastic body  14  and fixed electrode  73 ) to output electric signal SG 3  to the outside of input device  1  from terminal  731  of fixed electrode  73 . A proximity, touch or pressing manipulation by operation body U 1  on detection surface S 0  causes operation body U 1  and movable electrode  6  to form a capacitor in between to be capacitively coupled with each other. While operation body U 1  continues the proximity, touch or pressing manipulation on detection surface S 0 , electric signal SG 3  containing the change in the electric potential of movable electrode  6  contains a change in a capacitance of the above capacitor. Electric signal SG 3  containing a change in the capacitance of the capacitor is output from terminal  731  to the outside of input device  1 . 
       FIG. 7A  is a sectional view of input device  1  along line A 3 -A 3  shown in  FIG. 1  in which no pressing force by operation body U 1  is applied to detection surface S 0  of input device  1 , or before the central portion of dome body  31  is buckled. In this state, capacitor C 1  is formed between movable electrode  6  and fixed electrode  71 , and capacitor C 2  is formed between movable electrode  6  and fixed electrode  72 . Capacitors C 1  and C 2  are connected in series to each other via conductive dome body  31 . 
     Operation body U 1  contacts detection surface  51  of detection surface S 0  and presses click part  3  to compress elastic body  14 , thereby changing the distance between movable electrode  6  and fixed electrode  7  and changing the areas of respective regions of movable electrode  6  and fixed electrode  7  facing each other. This configuration changes a total capacitance of capacitors C 1  and C 2  accordingly. Electric signal SG 12  containing the change in the capacitance is output through terminals  711  and  721  to the outside of input device  1 . In  FIG. 7A , terminal  711  is grounded, thus constituting a grounding point, so that electrostatic charges stored in capacitors C 1  and C 2  flow into the grounding point. In  FIG. 7A , the diode connected to one electrode of capacitor C 2  visually illustrates that the electrostatic charges stored in capacitors C 1  and C 2  flow only to the grounding point, and does not actually exist. 
       FIG. 7B  is a sectional view of input device  1  along line A 3 -A 3  shown in  FIG. 1  in which a pressing force by operation body U 1  is applied to detection surface S 0  of input device  1 , or after the central portion of dome body  31  is buckled. In this state, the central portion of dome body  31  contacts tongue  722  of fixed electrode  7  via central portion  15   a  of insulator  15 . This situation will be referred to as an ON-state of a contact), so that dome body  31  and tongue  722  form capacitor C 3 . Capacitor C 2  is connected in parallel to capacitor C 3 . After the ON-state of the contact is started, analog electric signal SG 12  containing a change in the total capacitance of capacitors C 1 -C 3  caused due to an additional load is output to the outside of input device  1  through terminals  711  and  721 . 
     When pressing force P 1  by operation body U 1  is applied to pressing surface  30 , click part  3  elastically deforms, as shown in  FIG. 7B , to generate a click feeling that acts on operation body U 1  as described above. 
     In accordance with the embodiment, an entire of the upper surface of main body  712  of fixed electrode  71  is an opposing region facing movable electrode  6 , as shown in  FIG. 4 . Also, the entire upper surface of main body  723  of fixed electrode  72  is an opposing region that faces movable electrode  6 . Also, the entire upper surface of main body  732  of fixed electrode  73  is an opposing region that facing movable electrode  6 . Movable electrode  6  is indicated by dotted lines in  FIG. 4 . In accordance with the embodiment, the area of the opposing region of fixed electrode  71  is substantially equal to the sum of the area of the opposing region of fixed electrode  72  and the area of the opposing region of fixed electrode  73 . This configuration provides input device  1  with preferable sensitivity in a pressure-sensitive range of pressure-sensitive part  2 . The pressure-sensitive range is a possible range of depressed quantity in which operation body U 1  is configured to press click part  3 , or a range in which click part  3  is configured to deform from its normal, a convex shape to the buckled, a concave shape by the depression. 
     (2.3) Detection Part 
     Each of two detection parts  5  ( 5 L,  5 R) detects a proximity and a touch of detection surface S 2  in detection surface S 0  of input device  1  (see  FIG. 1 ) by operation body U 1 . Each of two detection parts  5  is a capacitive sensor. Two detection parts  5  are disposed at opposite sides of pressure-sensitive part  2 , respectively, when viewed from the upper surface of pressure-sensitive part  2  as shown in  FIG. 3 . In other words, two detection parts  5  are disposed at opposite sides of pressure detection part  2  in a direction intersecting upward and downward directions D 1 , or in a direction intersecting the movable direction of movable electrode  6 . In accordance with the embodiment, two detection parts  5  are disposed at opposite sides of pressure detection part  2  in a direction perpendicular to upward and downward directions D 1 . In accordance with the embodiment, the direction intersecting upward and downward directions D 1  is, for example, the longitudinal direction of housing  10 . Two detection parts  5  are disposed adjacent to pressure-sensitive part  2 . Two detection parts  5  have the same structure, but may not have the same structure. 
     Each detection part  5  includes auxiliary fixed electrode  50 , as shown in  FIG. 3 . Detection part  5 L includes auxiliary fixed electrode  50 L. Detection part  5 R includes auxiliary fixed electrode  50 R. Each detection part  5  is a self-capacitive sensor including a single auxiliary fixed electrode  50 , and detects a change in a capacitance generated between auxiliary fixed electrode  50  and operation body U 1 . Two auxiliary fixed electrodes  50  ( 50 L,  50 R) are fixed to two accommodating recesses  122  of body  12 , respectively. 
     Auxiliary fixed electrode  50  ( 50 L,  50 R) is made of electrically conductive material, such as metal, and has a rectangular flat plate shape. Auxiliary fixed electrode  50  includes main body  52  and auxiliary terminal  51 . 
     Auxiliary fixed electrode  50 L includes main body  52 L and auxiliary terminal  51 L. Auxiliary fixed electrode  50 R has includes main body  52 R and auxiliary terminal  51 R. Main body  52  ( 52 L,  52 R) has substantially a rectangular plate shape extending slenderly in the width direction perpendicular to both the longitudinal direction and the thickness direction of housing  10 . Auxiliary terminal  51  ( 51 L,  51 R) is an output part outputting, the outside of input device  1 , analog auxiliary electric signal SG 0  (SG 0 L, SG 0 R) containing a change in a capacitance between auxiliary fixed electrode  50  ( 50 L,  50 R) and operation body U 1 . Auxiliary terminal  51  ( 51 L,  51 R) projects from one edge of main body  52  ( 52 L,  52 R) extended in the longitudinal direction of main body  52  ( 52 L,  52 R), or in the width direction of the housing. Auxiliary terminal  51  ( 51 L,  51 R) projects from main body  52  ( 52 L,  52 R) in a direction away from cover  11 , and is further extended from main body  52  ( 52 L,  52 R) in a direction away from main body  52  ( 52 L 52 R) in the longitudinal direction of main body  52  ( 52 L,  52 R). 
     Each detection part  5  ( 50 L,  50 R), or each auxiliary fixed electrode  50  ( 50 L,  50 R), is accommodated in a corresponding accommodating recess  122  of body  12 . In detail, main body  52  ( 52 L,  52 R) is disposed on the bottom surface of a corresponding accommodating recess  122  so that almost only the upper surface of main body  52  ( 52 L,  52 R) out of the surfaces of main body  52  ( 52 L,  52 R) is exposed from upper surface  120  of body  12  (see  FIG. 3 ). The upper surface of main body  52  ( 52 L,  52 R) is substantially flush with upper surface  120 . Auxiliary terminals  51 L and  51 R project to outside of body  12  from openings K 1  and K 3  formed in side surface  12   a  of body  12 , respectively. 
     Each detection surface S 2  of cover  11  has substantially a shape identical to that of upper surface of main body  52  of a corresponding auxiliary fixed electrode  50  to overlap the upper surface of main body  52  when viewed from the upper surface of cover  11 . Operation body U 1  approximating or contacting detection surface S 2  of cover  11  causes auxiliary electric signal SG 0  containing a change in a capacitance of capacitor C 4  formed by auxiliary fixed electrode  50  and operation body U 1  (see  FIG. 5 ) to be output through auxiliary terminal  51 . In  FIG. 5 , the grounding point connected with capacitor C 4  denotes operation body U 1 . Also, in  FIG. 5 , the diode connected to one electrode of capacitor C 4  visually illustrates that the electrostatic charges stored in capacitor C 4  flow only toward the grounding point, and does not actually exist. 
     (2.4) Detection Circuit 
     Detection circuit  9  is electrically connected to input device  1 , as shown in  FIG. 2 . 
     Detection circuit  9  is configured to obtain electric signals SG 1  and SG 2  output from terminals  711  and  721  of pressure sensor  4  of pressure-sensitive part  2 , respectively. Detection circuit  9  is further configured to obtain electric signal SG 3  output from terminal  731  of pressure sensor  4 . Detection circuit  9  is further configured to obtain auxiliary electric signals SG 0 L and SG 0 R output from auxiliary terminals  51 L and  51 R of two detection parts  5 L and  5 R, respectively. Detection circuit  9  is configured to perform a proximity-detection process and/or a pressure-detection process based on the obtained electric signals. In the proximity-detection process, the detection circuit  9  detects whether or not operation body U 1  approximates or contacts detection surface S 0  of input device  1 . In the pressure-detection process, the detection circuit detects whether or not operation body U 1  presses detection surface S 0  of input device  1 . Detection circuit  9  determines a manipulation by operation body U 1  to detection surface S 0  based on a result of the proximity-detection process and the pressure-detection process, and outputs a result of the determination to the outside of input system  100 , for example, to a circuit module in electronic equipment having input system  100  installed thereto. 
     Electric signals SG 1 , SG 2 , SG 3 , SG 0 L and SG 0 R output from terminals  711 ,  721 ,  731 ,  51 L and  51 R, respectively, will be expressed as electric signals SG 1 , SG 2 , SG 3 , SG 0 L and SG 0 R output from fixed electrodes  71 ,  72 ,  73 ,  50 L and  50 R, respectively below. 
     Detection circuit  9  has plural detection modes. Detection circuit  9  selects one of the detection modes, and switches a processing from one of the proximity-detection process and the pressure-detection process based on the selected detection mode. Detection circuit  9  includes proximity detection circuit  91 , pressure detection circuit  92 , controller  93 , and determination unit  94 . 
     Proximity detection circuit  91  executes the proximity-detection process based on a control by controller  93 . Pressure detection circuit  92  executes the pressure-detection process based on a control by controller  93 . Controller  93  selects one detection mode from the detection modes, selects either one or both of proximity detection circuit  91  and pressure detection circuit  92  based on the selected detection mode, and causes the selected circuit to execute the corresponding process. In accordance with the embodiment, controller  93  has a switching function to switch a process between the pressure-detection process and the proximity-detection process. 
     The detection modes may include a Far mode, a Near mode, and a Touch mode. The Far mode and the Near mode are examples of the proximity-detection process. The Touch mode is an example of the pressure-detection process. 
     First, the proximity-detection process will be described.  FIGS. 8A and 8B  schematically illustrates an operation of input system  100  in the proximity-detection process. 
     In the Far mode, a proximity or a contact of detection surface S 0  by operation body U 1  is detected in a case where operation body U 1  approximates detection surface S 0  from far away. This mode is executed by proximity detection circuit  91 . In this mode, proximity detection circuit  91  executes the proximity-detection process employing both auxiliary fixed electrode  50  of detection part  5  and movable electrode  6  of pressure-sensitive part  2 . In detail, as shown in  FIG. 8A , proximity detection circuit  91  obtains electric signals SG 0 L, SG 0 R and SG 3  from fixed electrodes  50 L,  50 R and  73 , respectively, based on a control by controller  93 . Then, proximity detection circuit  91  processes each of the obtained electric signals to detect whether or not operation body U 1  approximates or contacts fixed electrodes  50 L,  50 R and  73 . In this mode, since the proximity-detection process is executed employing both auxiliary fixed electrode  50  of detection part  5  and movable electrode  6  of pressure-sensitive part  2 , the proximity or touch of detection surface S 0  by operation body U 1  is sensitively detected in the case where operation body U 1  approximates detection surface S 0  from far away. In this mode, the proximity-detection process is executed based on only electric signals SG 0 L, SG 0 R and SG 3  from fixed electrodes  50 L,  50 R and  73  out of electric signals SG 0 L, SG 0 R, SG 1 , SG 2  and SG 3  from fixed electrodes  50 L,  50 R,  71 ,  72  and  73  not on electric signals SG 1  and SG 2  from fixed electrodes  71  and  72 . 
     In the Near mode, the detection circuit detects a direction from which operation body U 1  approximates. This mode is executed by proximity detection circuit  91 . In this mode, proximity detection circuit  91  executes the proximity-detection process employing only detection part  5  of detection part  5  and pressure-sensitive part  2  without using pressure-sensitive part  2 . In detail, as shown in  FIG. 8B , proximity detection circuit  91  obtains electric signals SG 0 L and SG 0 R from fixed electrodes  50 L and  50 R, respectively, based on a control by controller  93 . Then, proximity detection circuit  91  processes the obtained electric signals to detect whether or not operation body U 1  approximates or contacting fixed electrodes  50 L and  50 R. In this mode, proximity detection circuit  91  opens the line from terminal  721 . This configuration suppresses a stray capacitance between fixed electrodes  50 L and  7  and a he stray capacitance between fixed electrodes  50 R and  7 , thereby increasing the detection sensitivity of detection parts  5 L and  5 R. As a result, the detection circuit detects sensitivity whether operation body U 1  approximates to detection surface S 1  from a direction on the side of auxiliary fixed electrode  50 L or from a direction on the side of auxiliary fixed electrode  50 R. In the case shown in  FIG. 8B , operation body U 1  in a direction on the side of auxiliary fixed electrode  50 R. In this mode, proximity detection circuit  91  executes the proximity-detection process using only electric signals SG 0 L and SG 0 R from fixed electrodes  50 L and  50 R out of electric signals SG 0 L, SG 0 R, SG 1 , SG 2  and SG 3  from fixed electrodes  50 L,  50 R,  71 ,  72  and  73 , without using electric signals SG 1 , SG 2  and SG 3  from fixed electrodes  71 ,  72  and  73 . 
     The pressure-detection process of input system  100  will be described below.  FIGS. 9A-9C  schematically illustrates operations of input system  100  in the pressure-detection process. 
     In the Touch mode, the detection circuit the input system executes the pressure-detection process. The Touch mode is executed by pressure detection circuit  92 . In this mode, pressure detection circuit  92  executes the pressure-detection process based on electric signals SG 1  and output SG 2  from fixed electrodes  71  and  72 , respectively. 
     The Touch mode includes a Touch mode #1, a Touch mode #2, and a Touch mode #3. 
     In the Touch mode #1, as shown in  FIG. 9A , pressure detection circuit  92  consecutively connects terminal  731  to the ground and electrically connects terminals  711  and  721  to each other. Pressure detection circuit  92  executes the pressure-detection process based on electric signals SG 1  and SG 2  obtained from terminals  711  and  721  electrically connected to each other, respectively. 
     Terminals  711  and  721  connected to each other connects capacitor C 1  formed by movable electrode  6  and fixed electrode  71  parallel to capacitor C 2  formed by movable electrode  6  and fixed electrode  72 . This configuration increases the sensitivity of pressure detection part  2  in the pressure-detection process. As a result, the detection circuit sensitively detects whether or not operation body U 1  presses movable electrode  6 . Since the line from terminal  731  is continuously grounded, the detection circuit sensitively detects whether or not operation body U 1  presses movable electrode  6 . 
     The Touch mode #2 is different from the Touch mode #1 in that terminals  711  and  721  are not connected to each other and that each of electric signals SG 1  and SG 2  from fixed electrodes  71  and  72  are processed individually (i.e., independently of each other). In detail, as shown in  FIG. 9B , pressure detection circuit  92  continuously connects terminal  731  to the ground. Pressure detection circuit  92  alternately employs electric signals SG 1  and SG 2  from respective terminals  711  and  721  to execute the pressure-detection process on fixed electrodes  71  and  72 . For example, pressure detection circuit  92  connects the line from terminal  721  to the ground to execute the pressure-detection process employing electric signal SG 1  from terminal  711 . On the other hand, pressure detection circuit  92  connects the line from terminal  711  to the ground to execute the pressure-detection process employing electric signal SG 2  from terminal  721 .  FIG. 9B  shows the state in which pressure detection circuit  92  executes the pressure-detection process employing electric signal SG 2  from terminal  721  and connects the line from terminal  711  to the ground. In this mode, since terminal  731  is continuously grounded, the detection circuit sensitively detects whether or not operation body U 1  presses movable electrode  6 . 
     The Touch mode #3 is different from the Touch mode #2 in that both of electric signals SG 1  and SG 2  from fixed electrodes  71  and  72 , respectively, are processed independently of each other. In detail, as shown in  FIG. 9C , pressure detection circuit  92  continuously connects terminal  731  to the ground. Pressure detection circuit  92  obtains electric signals SG 1  and SG 2  from terminals  711  and  721  in parallel and independently of each other, and executes the pressure-detection process on fixed electrode  71  and the pressure-detection process on fixed electrode  72  in parallel. In this mode, since terminal  731  is continuously grounded, the detection circuit sensitively detects whether or not operation body U 1  presses movable electrode  6 . 
     Detection circuit  9  executes the proximity-detection process and the pressure-detection process in a time-divisional manner. In other words, controller  93  causes proximity detection circuit  91  and pressure detection circuit  92  to time-divisionally execute their respective detection processes. For example, controller  93  causes proximity detection circuit  91  to execute the proximity-detection process while causing pressure detection circuit  92  not to execute the pressure-detection process for 0.5 seconds within each of periodically repeated detection periods of 1 second, and then, causes pressure detection circuit  92  to execute the pressure-detection process while causing proximity detection circuit  91  not to execute the proximity-detection process for the remaining 0.5 seconds within each of the detection period. 
     When detection circuit  9  detects a proximity or a touch of detection surface S 0  by operation body U 1  in the proximity-detection process, detection circuit  9  changes the time-division processing to decrease the processing period of the proximity-detection process and increase the processing period of the pressure-detection process by the time corresponding to the decreased time of the proximity-detection process. In other words, when proximity detection circuit  91  detects a proximity or a touch of detection surface S 0  by operation body U 1 , controller  93  decreases, in the time-division processing, the processing period of the proximity-detection process executed by proximity detection circuit  91  by a predetermined decreasing time. At this moment, controller  93  increases, in the time-division processing, the processing period of the pressure-detection process executed by pressure detection circuit  92  by the time corresponding to the predetermined decreasing time. For example, controller  93  causes proximity detection circuit  91  to execute the proximity-detection process while causing pressure detection circuit  92  not to execute the pressure-detection process for 0.1 seconds during each of periodically repeated detection periods of 1 second, and then, causes pressure detection circuit  92  to execute the pressure-detection process while causing proximity detection circuit  91  not to execute the proximity-detection process for the remaining 0.9 seconds. 
     The reason for this control is because, after operation body U 1  approximates or contacts detection surface S 0 , operation body U 1  tends to press detection surface S 0 , and thus, it is reasonable to change the time-division processing to put more weight on the pressure-detection process. In this manner, the detection circuit effectively executes the proximity-detection process and the pressure-detection process depending on the manipulation of operation body U 1 . 
     In accordance with the embodiment, as described above, after detecting a proximity or a touch of detection surface S 0  by operation body U 1  in the proximity-detection process, detection circuit  9  is configured to decrease the processing period of the proximity-detection process in the time-division processing by a predetermined decreasing time and increase the processing period of the pressure-detection process by the predetermined decreasing time. However, after detecting a proximity or a touch of detection surface S 0  by operation body U 1  in the proximity-detection process, detection circuit  9  may stop the time-division processing to execute only the pressure-detection process out of the proximity-detection process and the pressure-detection process without executing the proximity-detection process. In other words, when proximity detection circuit  91  detects a proximity or a touch of detection surface S 0  by operation body U 1 , controller  93  may stop the time-division processing and cause only pressure detection circuit  92  out of proximity processing circuit  91  and pressure detection circuit  92  to execute the pressure-detection process without causing proximity detection circuit  91  to execute the proximity-detection process. 
     Determination unit  94  determines various manipulations (operation inputs) of operation body U 1  based on combinations of detection results of proximity detection circuit  91  and pressure detection circuit  92 . The above determination results may include a touch, a push, and a click on pressure-sensitive part  2  and a touch on each detection part  5 . The push on pressure-sensitive part  2  is larger in load (larger in the change capacitance) than the touch, which means that the contact point does not reach the ON-state, or the state of generating the click feeling. The above manipulations include a moving direction of operation body U 1  with respect to pressure detection part  2 . 
       FIGS. 10A to 10D  schematically illustrates manipulations of operation body U 1  on input device  1 . In  FIGS. 10A to 10D , operation plate T 1  is positioned above pressure-sensitive part  2  and detection part  5  of input device  1 . Projection T 10  projecting toward pressure-sensitive part  2  is provided on the lower surface of operation plate T 1 . The manipulations include a state regarding at least one of a first operation process and a second operation process that will be described below. In the first operation process, operation body U 1  approximates detection surface S 0  until giving a pressing force (touch, push or click) to detection surface S 0 . In the second operation process, operation body U 1  moves away from detection surface S 0  after giving the pressing force to detection surface S 0 . The manipulations include the following seven manipulations. Operation plate T 1  may be employed in the following description, but may not necessarily be employed. 
     A first manipulation is a series of manipulations in which, as shown in  FIG. 10A , operation body U 1  contacts two detection parts  5  ( 5 L,  5 R) via operation plate T 1 , e.g. substantially simultaneously, and clicks pressure detection part  2  via projection T 10 . A pressing force is applied to detection surface S 1  by projection T 10 . 
     A second manipulation is a series of manipulations in which, as shown in  FIG. 10B , operation body U 1  first contacts, e.g. detection plate  5 L on the left side among detection parts  5  and pressure-sensitive part  2  via operation plate T 1 , then clicks pressure-sensitive part  2  via projection T 10 , and then moves to the right along an arcuate locus about projection T 10  to contact detection part  5 R on the right side. The movement of operation body U 1  along the arcuate locus causes operation plate T 1  also slightly rotates in an arcuate locus about projection T 10 . 
     A third manipulation is a series of manipulations in which, oppositely to the second manipulation, operation body U 1  moves along an arcuate locus to contact, via operation plate T 1 , e.g. detection part  5 R on the right side and detection part  5 L on the left side in this order. 
     A fourth manipulation is a series of manipulations in which, as shown in  FIG. 10C , operation body U 1  contacts detection parts  5  and pressure-sensitive part  2  via operation plate T 1  by, e.g. sliding on the upper surface of operation plate T 1  in a direction from detection part  5 L on the left side to pressure-sensitive part  2  and then to detection part  5 R on the right side. That is, in the fourth manipulation, operation body U 1  moves while contacting (or pushing) pressure-sensitive part  2  without the click operation. 
     A fifth manipulation is a series of manipulations in which, oppositely to the fourth manipulation, operation body U 1  contacts detection parts  5  and pressure-sensitive part  2  via operation plate T 1  by, e.g. substantially sliding on the upper surface of operation plate T 1  in a direction from detection part  5 R on the right side to detection part  5 L on the left side. 
     As described above, determination unit  94  determines not only types of manipulations (touch, push and click) on pressure-sensitive part  2 , but also the directions of the manipulations (the order of the manipulations) including the direction from which operation body U 1  approximates pressure-sensitive part  2  (from right, left, and above in the illustrated examples) and the direction in which operation body U 1  then moves away from pressure-sensitive part  2 . 
     A sixth manipulation is a series of manipulations in which, as shown in  FIG. 10D , operation body U 1  moves from a position directly above detection part  5 L on the left side in an obliquely lower direction to pressure-sensitive part  2  to click pressure-sensitive part  2  via operation plate T 1  and projection T 10 , and then further moves in an obliquely upward direction to a position directly above detection part  5 R on the right side (the hovering operation). That is, in this manipulation, operation body U 1  moves substantially on a V-shape locus. 
     A seventh manipulation is a series of manipulations in which, oppositely to the sixth manipulation, operation body U 1  moves from a position directly above detection part  5 R on the right side in an obliquely lower direction to pressure-sensitive part  2  to click pressure-sensitive part  2  via operation plate 
     T 1  and projection T 10 , and then, further moves in an obliquely upward direction to a position directly above detection part  5 L on the left side. 
     In the sixth and seventh manipulations, determination unit  94  does not determine which of detection parts  5 L and  5 R operation body U 1  contacts but determines from which of detection parts  5 L and  5 R operation body U 1  approximates pressure-sensitive part  2  or to which of detection parts  5 L and  5 R operation body U 1  moved away from pressure-sensitive part  2 . 
     In an eighth manipulation, operation body U 1  is tilted leftward to be positioned above detection part  5 L on the left side and pressure-sensitive part  2  but not above detection part  5 R. In a ninth manipulation, oppositely to the eighth manipulation, operation body U 1  is tilted rightward to be positioned above detection part  5 R on the right side and pressure-sensitive part  2  but not above detection part  5 L. That is, in the eighth and ninth manipulations, determination unit  94  determines a deviation direction of operation body U 1 , or toward which of the left-side and right-side detection parts  5  operation body U 1  is deviated to press pressure-sensitive part  2 . 
     Each of the proximity of, the touch of, and the push of detection surface S 0  by operation body U 1  is one of manipulations. 
     (3) Modifications 
     The exemplary embodiment described above is merely one of various exemplary embodiments of the present disclosure. The above-described exemplary embodiment may be modified variously depending on the design and the like as far as an object of the present disclosure can be achieved. Hereinafter, some modifications of the above-described exemplary embodiment will be described. The modifications described below may be applied in appropriate combinations. The above-described exemplary embodiment will be referred to as “the basic example”. 
     (3.1) Modification 1 
       FIG. 11  is a plan view of fixed electrode  7  of input device  1  according to a first modification of the exemplary embodiment. This modification is different from the basic example in the shapes of fixed electrodes  71 A,  72 A and  73 A. In detail, main body  712  of fixed electrode  71 A in the present modification has a plate shape substantially with a J-shape, as shown in  FIG. 11 . Terminal  711  of fixed electrode  71 A has the same structure as the basic example. Tongue  722  and terminal  721  of fixed electrode  72 A have the same structures of the basic example. Main body  723  of fixed electrode  72 A is configured to fit in a space which is not occupied by the J-shaped portion of fixed electrode  71 A without contacting fixed electrode  71 A. Fixed electrode  73 A has the same structure as the basic example. Fixed electrode  73 A is disposed in an empty space beyond the tip of the J-shape of main body  723  of fixed electrode  72 A and beside fixed electrode  72 A. 
     In the modification, similarly to the basic example, fixed electrode  7  includes fixed electrodes  71 A and  74 A, and fixed electrode  74 A is composed of fixed electrodes  72 A and  73 A. 
     In this modification, the entire upper surface of main body  712  of fixed electrode  71 A is an opposing region facing movable electrode  6  in upward and downward directions D 1 , as shown in  FIG. 11 . The entire upper surface of main body  723  of fixed electrode  72 A is an opposing region facing movable electrode  6  in upward and downward directions D 1 . The entire upper surface of main body  732  of fixed electrode  73 A is an opposing region facing movable electrode  6  in upward and downward directions D 1 . In  FIG. 11 , movable electrode  6  is indicated by dotted lines. In this modification, the area of the opposing region of fixed electrode  71 A is non-uniform, i.e., is not equal to the sum of the area of the opposing region of fixed electrode  72 A and the area of the opposing region of fixed electrode  73 A. This “non-uniformity” provides input device  1  with preferable sensitivity of pressure-sensitive part  2  in a pressure-sensitive range. Here, the pressure-sensitive range is a possible range of depressed quantity by which operation body U 1  is configured to press click part  3 , or a range in which click part  3  is configured to be reversed to a convex shape and further depressed. 
     (3.2) Modification 2 
       FIG. 12A  is a plan view of fixed electrode  7  of input device  1  according to Modification 2 of the embodiment. This modification is different from the basic example in that fixed electrode  7  is composed of two fixed electrodes  72 B and  73 B. Fixed electrode  72 B of this modification is an electrode obtained by unifying fixed electrodes  71  and  72  of the basic example. In detail, in this modification, main body  723  of fixed electrode  72 B has substantially a rectangular plate shape, as shown in  FIG. 12A . Cutout  722   k  having substantially a rectangular shape is provided in a corner of main body  723  of fixed electrode  72 B. Terminal  721  of fixed electrode  72 B has the same structure as that of the basic example. Main body  732  of fixed electrode  73 B has substantially a rectangular shape so as to be fit in a space in cutout  722   k  without contacting cutout  722   k . Terminal  731  of fixed electrode  73 B has the same structure as that of the basic example. 
       FIG. 12B  schematically illustrates an operation of input device  1  according to Modification 2. In the Touch mode according to this modification, as shown in  FIG. 12B , pressure detection circuit  92  continuously connects terminal  731  to the ground and executes the pressure-detection process based on electric signal SG 2  from terminal  721 . 
     In this modification, fixed electrode  72 B corresponds to an electrode obtained by combining fixed electrodes  71  and  72  of the basic example. Therefore, this modification does not have a gap corresponding to the gap between fixed electrodes  71  and  72  of the basic example. Accordingly, the area of fixed electrode  71 B of this modification is larger than the sum of the areas of fixed electrodes  71  and  72  of the basic example. This configuration provides pressure detection part  2  in the pressure-detection process with larger sensitivity than the basic example. 
     (3.3) Other Modifications 
     Elastic body  14  of the basic example has an electrical conductivity. Elastic body  14  may have an electrical insulation property instead. In this case, elastic body  14  may preferably be made of material, such as dielectric elastomer, having a relatively high dielectric constant. In the case where elastic body  14  has an insulation property, input device  1  may not include insulator  15 . 
     In the basic example, insulator  15  is disposed between elastic body  14  and fixed electrode  7 . In this case, it is easy to perform a laminating process (lamination) to laminate insulator  15  on fixed electrode  7 . However, this configuration may be modified. For example, the position of elastic body  14  and insulator  15  may be exchanged with each other such that elastic body  14  is disposed between insulator  15  and fixed electrode  7 . In this case, it is easy to form elastic body  14  by using fixed electrode  7  as a reference. 
     In the basic example, insulator  15  is a sheet separated from body  12  and disposed between other two members, or between elastic body  14  and fixed electrode  7 . However, insulator  15  may be formed unitarily with body  12 . The upper wall of body  12  facing elastic body  14  may be a thin film wall entirely covering the surface of fixed electrode  7 , and the thin film wall may function as an insulator. 
     In the basic example, the number of detection parts  5  is two, and two detection parts  5  are disposed on both sides, or the left and right sides, of pressure-sensitive part  2 . However, the number of detection parts  5  may be one or three or more. 
     In the basic example, operation plate T 1  is disposed on input device  1 , and the operation input to input device  1  is made via operation plate T 1 . However, operation plate T 1  may not be included, and the operation input to input device  1  may be made directly onto cover  11 . 
     When the pressure sensor of the conventional input device is used to detect a proximity or a touch by the operation body, the above-described capacitance decreases sensitivity of the detection. Therefore, the pressure sensor hardly improves the sensitivity of detecting a proximity or a touch by a finger. 
     In contrast, the input device according to the embodiment improves the sensitivity of detecting a proximity or a touch by operation body U 1 , or a finger, as described above. 
     In the above embodiment, terms, such as “upper surface”, “lower surface”, “upward direction” and “downward direction”, indicating directions indicate relative directions depending on a relative positional relationship between components of input device  1 , and thus do indicate absolute directions, such as a vertical direction. 
     (4) Summary 
     Input device  1  configured to be operated by operation body U 1  includes detection surface S 0  configured to be operated by operation body U 1 , fixed electrode  71 , movable electrode  6 , terminals  711  and  731  configured to be connected to an outside of input device  1 , and direct-connection line TD 1 . Movable electrode  6  has a lower surface facing an upper surface of fixed electrode  71  to be capacitively coupled to fixed electrode  71  and is displaceable to approach fixed electrode  71  in response to a pressing of detection surface S 0  by operation body U 1 . Terminal  711  is configured to output, to the outside of input device  1 , an electric signal SG 1  containing a change in a capacitance between fixed electrode  71  and movable electrode  6 . Terminal  731  is configured to output, from movable electrode  6  to the outside of input device  1 , an electric signal SG 3  containing a change in a capacitance between operation body U 1  and movable electrode  6 . Direct-connection line TD 1  electrically connects movable electrode  6  to terminal  731  via no capacitor. 
     This configuration allows direct-connection line TD 1  to output electric signal SG 3  from movable electrode  6  to detection circuit  9  line TD 1  without being affected by a capacitance. Accordingly, the device sensitively detects a proximity or a touch of detection surface S 0  by operation body U 1  based on electric signal SG 3  from movable electrode  6 . In other words, the device detects both a proximity and a touch of detection surface S 0  by operation body U 1  at a high sensitivity by using movable electrode  6 . 
     Direct-connection line TD 1  may include fixed electrode  73  having an upper surface facing a lower surface of movable electrode  6 . 
     In this configuration, fixed electrode  73  may constitute direct-connection line TD 1 . 
     Input device  1  may further include insulator  15  between movable electrode  6  and the fixed electrode. Insulator  15  has cutout  151  provided therein. Direct-connection line TD 1  may electrically connect movable electrode  6  to fixed electrode  73  through cutout  151 . 
     This configuration secures electrical connection between movable electrode  6  and fixed electrode  73  with direct-connection line TD 1  while securing insulation between movable electrode  6  and fixed electrode  72  by insulator  15 . 
     Input device  1  may further include fixed electrode  72  and terminal  721  that is configured to be connected to the outside of input device  1 . Fixed electrode  72  has an upper surface facing a lower surface of movable electrode  6  to be capacitively coupled to movable electrode  6 . Terminal  721  is configured to output, to the outside of input device  1 , an electric signal SG 2  that contains a change in a capacitance between fixed electrode  72  and movable electrode  6 . The area of a region of the upper surface of fixed electrode  71  facing the lower surface of movable electrode  6  is substantially identical to the sum of the area of a region of the upper surface of fixed electrode  71  facing the lower surface of movable electrode  6  and the area of a region the upper surface of fixed electrode  71  facing the lower surface of movable electrode  6 . 
     The area of the region of the upper surface of fixed electrode  71  facing the lower surface of movable electrode  6  may be different from the sum of the area of the region of the upper surface of fixed electrode  71  facing the lower surface of movable electrode  6  and the area of the region of the upper surface of fixed electrode  71  facing the lower surface of movable electrode  6 . 
     Input device  1  may further include one or more auxiliary fixed electrodes  50  and one or more auxiliary terminals  51  configured to be connected to the outside of input device  1 . Each of the one or more auxiliary fixed electrodes  50  forms a capacitance between operation body U 1  and the each of the one or more auxiliary fixed electrodes  50 . Respective one of the one or more auxiliary terminals  51  is configured to output, to the outside of input device  1 , respective of one or more auxiliary electric signals SG 0  containing a change in the capacitance between the operation body U 1  and the each of the one or more auxiliary fixed electrodes  50 . 
     This configuration allows detection circuit  9  to sensitively detect a proximity or a touch of detection surface S 0  by operation body U 1  based on auxiliary electric signal SG 0  from auxiliary fixed electrode  50 . In other words, since the above-mentioned proximity and touch can be detected employing movable electrode  6  and auxiliary fixed electrode  50 , it is possible to expand the substantial detection range of detection surface S 0 . 
     Input system  100  includes input device  1  and detection circuit  9 . Detection circuit  9  is connected to terminal  711 , terminal  731 , and one or more auxiliary terminals  51  of input device  1 . 
     Detection circuit  9  may be configured to detect whether or not operation body U 1  approximates or contacts detection surface S 0  based on electric signal SG 3  and one or more auxiliary electric signals SG 0  out of electric signal SG 1 , electric signal SG 3  and one or more auxiliary electric signals SG 0 . 
     In this configuration, the system detects a proximity or a touch of detection surface S 0  by operation body U 1  employing movable electrode  6  and auxiliary fixed electrodes  50 , or whole of the electrodes. Particularly in this case, the system sensitively detects a proximity of operation body U 1  approximating detection surface S 0  from a far distance. 
     Detection circuit  9  may detect whether or not operation body U 1  approximates or contacts detection surface S 0  based on only one or more auxiliary electric signals SG 0  out of electric signal SG 1 , electric signal SG 3  and one or more auxiliary electric signals SG 0 . 
     In this configuration, the system detects a proximity or a touch of detection surface S 0  by operation body U 1  employing auxiliary fixed electrode  50 . Particularly in this case, the system effectively identifies a direction from which operation body U 1  approximates detection surface S 0 . 
     Detection circuit  9  may be configured to execute a pressure-detection process to detect an operation of pressing detection surface S 0  by operation body U 1  based on electric signal SG 1 , to execute a proximity-detection process to detect a proximity or a touch of detection surface S 0  by operation body U 1  based on electric signal SG 3 , and to switch between the pressure-detection process and the proximity-detection process. 
     Detection circuit  9  may be configured to execute the pressure-detection process and the proximity-detection process repetitively in a time-divisional manner. 
     After detecting a proximity or a touch of detection surface S 0  by operation body U 1  by the proximity-detection process, the detection circuit  9  may decrease the time period for executing the proximity-detection process and increase the processing time period for executing the pressure-detection process. 
     In this configuration, after detecting a proximity or a touch of detection surface S 0  by operation body U 1  by the proximity-detection process, detection circuit  9  can focus on the pressure-detection process. 
     After detecting a proximity or a touch of detection surface S 0  by operation body U 1  by the proximity-detection process, the detection circuit  9  may decrease the time period for executing the proximity-detection process by a predetermined decreasing time and increase the processing time period for executing the pressure-detection process by the predetermined decreasing time. 
     After having detected a proximity or a touch of detection surface S 0  by operation body U 1  by the proximity-detection process, the detection circuit  9  may execute only the pressure-detection process without executing the proximity-detection process. 
     REFERENCE MARKS IN THE DRAWINGS 
     
         
           1  input device 
           6  movable electrode 
           9  detection circuit 
           15  insulator 
           50  auxiliary electrode 
           51  auxiliary terminal 
           71 ,  71 A fixed electrode (first fixed electrode) 
           72 ,  72 A,  72 B fixed electrode (third fixed electrode) 
           73 ,  73 A,  73 B fixed electrode (second fixed electrode) 
           711  terminal (first terminal) 
           721  terminal (third terminal) 
           731  terminal (second terminal) 
           100  input system 
         S 0  detection surface 
         SG 1  electric signal (first electric signal) 
         SG 2  electric signal (third electric signal) 
         SG 3  electric signal (second electric signal) 
         SG 0 , SG 0 L, SG 0 R auxiliary electric signal 
         TD 1  direct-connection line 
         U 1  operation body