Patent Publication Number: US-10768658-B2

Title: Multi-directional input device

Description:
BACKGROUND OF THE INVENTION 
     (1) Field of the Invention 
     The present invention relates to a multi-directional input device. 
     (2) Description of Related Art 
     As shown in JP 2000-112552 A, a conventional multi-directional input device includes a case, a pair of upper and lower arms, an operation shaft, an actuating member, a compression coil spring, and a plurality of electric components. The case has a bottom plate. The pair of upper and lower arms are movably supported in two directions orthogonal to each other in the case, and each has an elongated hole extending in a direction orthogonal to a moving direction. The operation shaft is rotatable in a state of passing through each elongated hole. The actuating member is movably supported in an axial direction of the operation shaft at a lower end of the operation shaft projecting downward of the lower arm, and is provided with a downward convex spherical trapezoidal portion whose diameter decreases downward. The compression coil spring presses the spherical trapezoidal portion of the actuating member against the bottom plate to return the operation shaft to a neutral state. The plurality of electric components are operated through each of the arms by rotation of the operation shaft. 
     Here, the operation shaft is rotatably supported by the lower arm in a direction where the elongated hole extends, in order to prevent the operation shaft from coming off. In addition, in consideration of assemblability, the operation shaft is rotatably supported by the lower arm in the direction where the elongated hole extends, by snap-engaging a projecting shaft support portion provided on an outer surface of the operation shaft with a recessed engaging portion provided in the elongated hole of the lower arm. 
     PRIOR ART DOCUMENT 
     Patent Document 
     Patent Document 1: JP 2000-112552 A 
     SUMMARY OF THE INVENTION 
     However, in the conventional multi-directional input device as described above, since the snap-engaging portion between the operation shaft and the lower arm serves as a rotation center of the operation shaft, it becomes difficult to reduce the entire height of the device when the rotation radius of the operation shaft is increased. Further, in order to ensure the assemblability, it is difficult to provide sufficient strength to the snap-engaging portion between the operation shaft and the lower arm. 
     The present invention has been made in view of the problems as described above, and an object of the present invention is to provide a multi-directional input device, in which the entire height of the device can be reduced even when the rotation radius of an operation shaft is increased and the device can be downsized without lowering the strength of the operation shaft and a lower arm. 
     In order to achieve the above object, according to a first aspect of the present invention, there is provided a multi-directional input device, including: a case having a bottom plate; a pair of upper and lower arms supported to be movable in two orthogonal directions in the case, the pair of upper and lower arms each having an elongated hole extending in a direction orthogonal to a moving direction; an operation shaft that is rotatable in a state of penetrating each elongated hole, an actuating member that is supported to be movable in an axial direction of the operation shaft at a lower end of the operation shaft projecting downward of the lower arm, and is provided with a downward convex spherical trapezoidal portion whose diameter decreases downward; a compression coil spring that is provided between the operation shaft and the actuating member, and presses the downward convex spherical trapezoidal portion against the bottom plate to return the operation shaft to a neutral state; and a plurality of electric components operated via each arm by rotation of the operation shaft. An upward convex spherical trapezoidal portion whose diameter decreases upward is provided at a lower end of the operation shaft projecting downward of the lower arm. A receiving portion for the upward convex spherical trapezoidal portion is provided in the case. The receiving portion has a receiving surface that is configured with a spherical surface having a radius of curvature identical to a radius of curvature of a spherical zone of the upward convex spherical trapezoidal portion, the receiving surface against which a spherical zone of the upward convex spherical trapezoidal portion is pressed from downward by the compression coil spring. The operation shaft is supported to be rotatable about a center of curvature of the receiving surface. 
     Further, according to a second aspect of the present invention, there is provided a multi-directional input device, including: a case having a bottom plate; a pair of upper and lower arms supported to be movable in two orthogonal directions in the inside of the case, the pair of upper and lower arms each having an elongated hole extending in a direction orthogonal to a moving direction; an operation shaft that is rotatable in a state of penetrating each elongated hole; an actuating member that is supported to be movable in an axial direction of the operation shaft at a lower end of the operation shaft projecting downward of the lower arm, and is provided with a downward convex spherical trapezoidal portion whose diameter decreases downward; a compression coil spring that is provided between the operation shaft and the actuating member, and presses the downward convex spherical trapezoidal portion against the bottom plate to return the operation shaft to a neutral state; and a plurality of electric components operated via each arm by rotation of the operation shaft. The actuating member is supported at a lower end of the operation shaft projecting downward of the lower arm in a state of reducing rotation around an axis of the operation shaft and is provided with a protrusion projecting radially outward from an upper end of the downward convex spherical trapezoidal portion. The protrusion is inserted to be movable vertically in a guide groove that extends in a vertical direction on an inner wall of the case, so that rotation around an axis of the operation shaft of the actuating member is reduced. 
     Further, according to a third aspect of the present invention, there is provided a multi-directional input device, including: a case having a bottom plate; a pair of upper and lower arms supported to be movable in two orthogonal directions in the case, the upper and lower arms each having an elongated hole extending in a direction orthogonal to a moving direction; an operation shaft that is rotatable in a state of penetrating each elongated hole, an actuating member that is supported to be movable in an axial direction of the operation shaft at a lower end of the operation shaft projecting downward of the lower arm, and is provided with a downward convex spherical trapezoidal portion whose diameter decreases downward; a compression coil spring that is provided between the operation shaft and the actuating member, and presses the downward convex spherical trapezoidal portion against the bottom plate to return the operation shaft to a neutral state; and a plurality of electric components operated via each arm by rotation of the operation shaft. An upward convex spherical trapezoidal portion whose diameter decreases upward is provided at a lower end of the operation shaft projecting downward of the lower arm. A receiving portion for the upward convex spherical trapezoidal portion is provided in the case. The receiving portion has a receiving surface that is configured with a spherical surface having a radius of curvature identical to a radius of curvature of a spherical zone of the upward convex spherical trapezoidal portion, the receiving surface against which a spherical zone of the upward convex spherical trapezoidal portion is pressed from downward by the compression coil spring. The operation shaft is supported to be rotatable about a center of curvature of the receiving surface. The lower arm has a curved upper surface provided along a cylindrical surface arranged coaxially on one horizontal axis that passes through the center of curvature of the receiving surface and extends in a moving direction of the lower arm. The operation shaft is provided with an engaging portion with the lower arm. The engaging portion has a downward engaging surface that is curved along the curved upper surface of the lower arm and is movable on the curved upper surface of the lower arm when the operation shaft rotates. 
     Further, according to a fourth aspect of the present invention, there is provided the multi-directional input device according to the third aspect, further including: a pusher that is supported to be vertically movable in the case; and a pressing switch that detects pressing movement of the operation shaft. The pusher is moved by the lower arm that is moved downward with pressing movement of the operation shaft. The pressing switch is operated via the pusher. 
     According to the present invention, an upward convex spherical trapezoidal portion whose diameter decreases upward is provided at the lower end of the operation shaft projecting downward of the lower arm, and the receiving portion for the upward convex spherical trapezoidal portion is provided in the case. The receiving portion has a receiving surface that is configured with a spherical surface having the same radius of curvature as the radius of curvature of the spherical zone of the upwardly convex spherical trapezoidal portion, the receiving surface against which a spherical zone of the upward convex spherical trapezoidal portion is pressed from downward by the compression coil spring. The operation shaft is supported to be rotatable about the curvature center of the receiving surface. In this manner, since the operation shaft is supported to be rotatable about the curvature center of the receiving surface of the receiving portion while being prevented from coming off by the receiving portion positioned downward of the lower arm, the entire height of the device is reduced even if the rotation radius of the operation shaft is increased, and the device can be downsized without lowering the strength of the operation shaft and the lower arm. 
     Further, the actuating member is supported by the lower end of the operation shaft in a state in which the rotation around an axis of the operation shaft is regulated, and is provided with a protrusion projecting radially outward from an upper end of the downward convex spherical trapezoidal portion. The protrusion is inserted so as to be movable vertically in a guide groove that extends in a vertical direction on an inner wall of the case, so that rotation around an axis of the operation shaft of the actuating member is regulated. In this manner, rotation around an axis of the operation shaft is regulated via the actuating member. Therefore, degree of freedom in a shape of the lower arm is increased, the lower arm can be downsized, and the device can be downsized. 
     Further, an upward convex spherical trapezoidal portion whose diameter decreases upward is provided at the lower end portion of the operation shaft projecting downward of the lower arm, and a receiving portion for the upward convex spherical trapezoidal portion is provided in the case. The receiving portion has a receiving surface that is configured with a spherical surface having the same radius of curvature as radius of curvature of a spherical zone of the upward convex spherical trapezoidal portion, the receiving surface against which a spherical zone of the upward convex spherical trapezoidal portion is pressed from downward by the compression coil spring. The operation shaft is supported so as to be rotatable about the center of curvature of the receiving surface. The lower arm has a curved upper surface provided along a cylindrical surface arranged coaxially on one horizontal axis that passes through the center of curvature of the receiving surface and extends in a moving direction of the lower arm. The operation shaft is provided with an engaging portion with the lower arm. The engaging portion has a downward engaging surface that is curved along the curved upper surface of the lower arm and is movable on the curved upper surface of the lower arm when the operation shaft rotates. In this manner, the operation shaft in a state of being inserted through an elongated hole of the lower arm from downward is rotated by 90° so that a downward engaging surface of the engaging portion of the operation shaft is arranged to face the curved upper surface of the lower arm for assembly. Accordingly, the operation shaft and the lower arm can be provided with enough strength, and the device can be downsized without lowering of the strength of the operation shaft and the lower arm. 
     Further, the pusher supported movably in the vertical direction and the pressing switch for detecting the pressing movement of the operation shaft are further included in the case, the lower arm moving downward with the pressing movement of the operation shaft moves downward the pusher, and the pressing switch is operated via the pusher. In this manner, before the pusher is incorporated, the lower arm has degree of freedom in a downward direction, and there is no possibility of interference between the downward engaging surfaces of the engaging portions of the operation shaft and the curved upper surface of the lower arm even if the operation shaft is rotated by 90° and assembled. For this reason, a gap (clearance) between the downward engaging surface of the engaging portion of the operation shaft and the curved upper surface of the lower arm can sufficiently be reduced, and the pressing switch can be operated with a short stroke. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded perspective view of a multi-directional input device according to an embodiment of the present invention; 
         FIG. 2  is a perspective view of the multi-directional input device according to the embodiment of the present invention; 
         FIG. 3  is a perspective view of a state in which a frame and a cover of  FIG. 2  are transparent; 
         FIG. 4  is a perspective view of a state in which an upper arm and a lower arm in  FIG. 3  are transparent; 
         FIG. 5  is a perspective view of a state in which a body of  FIG. 4  is transparent; 
         FIG. 6  is a perspective view of a state in which an operation shaft, first and second sliders, and a pusher in  FIG. 5  are transparent; 
         FIG. 7  is a plan (top) view of the multi-directional input device according to the embodiment of the present invention; 
         FIG. 8  is a cross-sectional view taken along line A-A of  FIG. 7 ; 
         FIG. 9  is a cross-sectional view taken along line B-B in  FIG. 7 ; 
         FIG. 10  is a cross-sectional view taken along line C-C of  FIG. 7 ; 
         FIG. 11  is a cross-sectional view taken along line D-D of  FIG. 7 ; 
         FIG. 12  is a cross-sectional view taken along line E-E of  FIG. 7 ; 
         FIG. 13  is a cross-sectional view taken along line F-F of  FIG. 7 ; 
         FIG. 14  is a view showing an operation system of a pressing switch; 
         FIG. 15  is a cross-sectional plan view of an operation shaft accommodation hole of the body; 
         FIG. 16  is a plan (top) view for explaining operation of the multi-directional input device according to the embodiment of the present invention; and 
         FIG. 17  is a cross-sectional view taken along line A-A of  FIG. 16 . 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Hereinafter, a multi-directional input device according to an embodiment of the present invention will be described based on the drawings. 
     As shown in  FIGS. 1 to 17 , the multi-directional input device according to the embodiment of the present invention includes a case  100 , a pair of upper and lower arms  200  and  300 , an operation shaft  400 , an actuating member  500 , a compression coil spring  600 , first and second sliders  700  and  800 , a pusher  900 , first and second variable resistors  1000  and  1100  which are first and second electric components, a pressing switch  1200  which is a third electric component, and a substrate  1300 . 
     In coordinate axes shown in  FIGS. 1 to 17 , a Y 1 -Y 2  direction is a front-rear direction (depth direction) of the multi-directional input device, an X 1 -X 2  direction is a lateral direction (width direction) of the multi-directional input device, and a Z 1 -Z 2  direction is a vertical direction (height direction) of the multi-directional input device. The Y 1 -Y 2  direction intersects the X 1 -X 2  direction at right angles, and the Z 1 -Z 2  direction intersects the Y 1 -Y 2  direction and the X 1 -X 2  direction at right angles. The Y 1 -Y 2  direction and the X 1 -X 2  direction correspond to the “two orthogonal directions” in the claims. The Z 1 -Z 2  direction corresponds to the “vertical direction” in the claims. 
     As shown in  FIG. 1 ,  FIG. 2 , and  FIG. 7  to  FIG. 13 , the case  100  is provided with a cuboid shaped body  110  made of insulating synthetic resin, a cover  120  that is made of insulating synthetic resin, has a dome-like shape which is convex upward and a diameter decreasing upward, is provided with a circular opening  121  for inserting the operation shaft  400  at the top, and is placed on a top surface of the body  110 , and a frame  130  that is made of sheet metal and has a rectangular bottom plate  131  covering a lower surface of the body  110 . The cover  120  and the frame  130  are positioned and connected to and assembled with the body  110 . 
     As shown in  FIGS. 1 to 4, 8 to 13, and 15 , the body  110  has an operation shaft accommodation portion  111  for rotatably accommodating a lower end of the operation shaft  400 , a receiving portion  112  for rotatably supporting the lower end of the operation shaft  400  while also serving to prevent the operation shaft  400  from coming off, a guide groove  113  for regulating rotation of the operation shaft  400  about the axis via the actuating member  500 , a first slider accommodation portion  114  for accommodating the first slider  700  movably in the front-rear direction, a second slider accommodation portion  115  for accommodating the second slider  800  movably in the lateral direction, a pressing switch accommodation portion  116  for accommodating the pressing switch  1200 , a pusher accommodation portion  117  for movably accommodating the pusher  900  in the vertical direction, a pair of left and right guide plates  118   a  and  118   b  for moving the upper arm  200  in an arc shape in the front-rear direction, and a pair of front and rear guide plates  119   a  and  119   b  for moving the lower arm  300  in an arc shape in the lateral direction. 
     As shown in  FIGS. 8 to 10 and 15 , the operation shaft accommodation portion  111  is a cylindrical hole penetrating a central portion of the body  110  in the vertical direction. 
     As shown in  FIGS. 8 to 10 , the receiving portion  112  is a receiving portion of an upward convex spherical trapezoidal portion  410  provided at a lower end of the operation shaft  400  projecting downward of the lower arm  300  and having a diameter decreasing upward. The receiving portion  112  is formed into an upward concave spherical shape whose diameter decreases upward in a state of being projecting inward from an upper end opening edge of the operation shaft accommodation portion  111 . The receiving portion  112  has a receiving surface  112   a , which is a receiving portion configured with a surface of a spherical zone shape having the radius of curvature same as the radius of curvature of a spherical zone  411  of a side surface portion of the upward convex spherical trapezoidal portion  410 , and against which the spherical zone  411  of the upward convex spherical trapezoidal portion  410  is pressed downward by the compression coil spring  600 . The receiving portion  112  supports the operation shaft  400  so as to be rotatable around the center of curvature of the receiving surface  112   a , while also serving to prevent the operation shaft  400  from coming off. 
     As shown in  FIGS. 10 and 15 , the guide groove  113  is a groove having a U-shaped cross section, which is provided on a peripheral wall of the operation shaft accommodation portion  111  to extend in the vertical direction. A plurality of the guide grooves  113  are provided at equal intervals in a circumferential direction on the peripheral wall of the operation shaft accommodation portion  111 . One of the guide grooves  113  is provided in each of four directions which are diagonal directions of the body  110 . 
     As shown in  FIGS. 8 and 11 , the first slider accommodation portion  114  is provided between the operation shaft accommodation portion  111  of the body  110  and a left side surface of the body  110 , and has a first lower movement path  114   a , a first fixing surface  114   b , a first upper movement path  114   c , and a first concave portion  114   d . The first lower movement path  114   a  is provided on a lower surface of the body  110  between the operation shaft accommodation portion  111  of the body  110  and the left side surface of the body  110 . The first lower movement path  114   a  is a rectangular bottomed hole whose longitudinal direction is the front-rear direction, and a rectangular flat bottom surface of the hole, that is, a flat top surface of the first lower movement path  114   a  is the first fixing surface  114   b . The first upper movement path  114   c  is provided at the center of the first fixing surface  114   b . The first upper movement path  114   c  is a rectangular hole whose longitudinal direction is the front-rear direction, and penetrates an upper surface of the body  110  to connect the first lower movement path  114   a  and the inside of the cover  120 . 
     The first concave portion  114   d  is a fitting portion to be fitted with a first convex portion  760  provided on the first slider  700  when the first slider  700  is at a neutral position, and is provided on each of the first fixing surface  114   b  located closer to a front side relative to the first upper movement path  114   c  and the first fixing surface  114   b  located closer to a rear side relative to the first upper movement path  114   c . A fitting shape of the first concave portion  114   d  with the first convex portion  760  is a cylindrical surface formed in a cylindrical surface extending in the lateral direction orthogonal to a moving direction (front-rear direction) of the first slider  700 , and has an upward convex arc-like cross-sectional shape. 
     As shown in  FIGS. 9 and 12 , the second slider accommodation portion  115  is provided between the operation shaft accommodation portion  111  of the body  110  and a rear side surface of the body  110 , and has a second lower movement path  115   a , a second fixing surface  115   b , a second upper movement path  115   c , and a second concave portion  115   d . The second lower movement path  115   a  is provided on a lower surface of the body  110  between the operation shaft accommodation portion  111  of the body  110  and the rear side surface of the body  110 . The second lower movement path  115   a  is a rectangular bottomed hole whose longitudinal direction is the lateral direction, and a rectangular flat bottom surface of the hole, that is, a flat top surface of the second lower movement path  115   a  is the second fixing surface  115   b . The second upper movement path  115   c  is provided at the center of the second fixing surface  115   b . The second upper movement path  115   c  is a rectangular hole whose longitudinal direction is the lateral direction, and penetrates the upper surface of the body  110  to connect the second lower movement path  115   a  and the inside of the cover  120 . 
     The second concave portion  115   d  is a fitting portion to be fitted with a second convex portion  860  provided on the second slider  800  when the second slider  800  is at a neutral position, and is provided on each of the first fixing surface  114   b  located closer to a left side relative to the second upper movement path  115   c  and the second fixing surface  115   b  located closer to a right side relative to the second upper movement path  115   c . A fitting shape of the second concave portion  115   d  with the second convex portion  860  is a cylindrical surface formed in a cylindrical surface extending in the front-rear direction orthogonal to a moving direction (lateral direction) of the second slider  800 , and has an upward convex arc-like cross-sectional shape. 
     As shown in  FIGS. 9 and 13 , the pressing switch accommodation portion  116  is provided on the lower surface of the body  110  between the operation shaft accommodation portion  111  of the body  110  and the front side surface of the body  110 . The pressing switch accommodation portion  116  is a rectangular bottomed shallow hole whose longitudinal direction is the lateral direction. 
     As shown in  FIGS. 9 and 13 , the pusher accommodation portion  117  is provided between the operation shaft accommodation portion  111  of the body  110  and the front side surface of the body  110 . The pusher accommodation portion  117  is provided on a rectangular bottom surface of the hole which is the pressing switch accommodation portion  116 , that is, on a top surface of the pressing switch accommodation portion  116 . The pusher accommodation portion  117  is a rectangular hole whose longitudinal direction is the lateral direction and penetrates the upper surface of the body  110  to connect the pressing switch accommodation portion  116  and the inside of the cover  120 . 
     As shown in  FIGS. 4 and 8 , the left and right guide plates  118   a  and  118   b  are upward convex, bow-shaped plates which are raised from both left and right ends of the upper surface of the body  110  and opposed in the lateral direction. Arc-shaped left and right arm hooks  118   c  and  118   d , which are arc-shaped step surfaces one step lower, are provided inside arc-shaped upper end surfaces of the left and right guide plates  118   a  and  118   b . The arc-shaped upper end surfaces of the left and right guide plates  118   a  and  118   b  and the arc-shaped left and right arm hooks  118   c  and  118   d  are provided along a cylindrical surface coaxially arranged on one horizontal axis (hereinafter referred to as “X axis”) that passes through the center of curvature of the receiving surface  112   a  and extends in the lateral direction. On the upper surface of the body  110 , the first upper movement path  114   c  is opened along an inner surface of the left guide plate  118   a.    
     As shown in  FIGS. 4 and 9 , the front and rear guide plates  119   a  and  119   b  are upward convex, bow-shaped plates which are raised from both front and rear ends of the upper surface of the body  110  and opposed in the front-rear direction. An arc-shaped rear arm hook  119   c , which is an arc-shaped step surface lower by one step, is provided only inside the arc-shaped upper end of the rear guide plate  119   b  between the arc-shaped upper ends of the front and rear guide plates  119   a  and  119   b . The arc-shaped upper ends of the front and rear guide plates  119   a  and  119   b  and the arc-shaped rear arm hook  119   c  of the rear guide plate  119   b  are provided along a cylindrical surface coaxially arranged on one horizontal axis (hereinafter referred to as “Y axis”) that passes through the center of curvature of the receiving surface  112   a  and extends in the front-rear direction. On the upper surface of the body  110 , the second upper movement path  115   c  is opened along an inner surface of the rear guide plate  119   b , and the pusher accommodation portion  117  is opened along an inner surface of the front guide plate  119   a.    
     The cover  120  is provided with a pair of left and right guide holes  121   a  and  121   b  for moving the upper arm  200  in an arc shape in the front and rear direction, and a pair of front and rear guide holes  122   a  and  122   b  for moving the lower arm  300  in an arc shape in the lateral direction. 
     As shown in  FIGS. 1 and 8 , the left and right guide holes  121   a  and  121   b  are upward convex, bow-shaped notches which are opposed in the lateral direction in which the left and right guide plates  118   a  and  118   b  are fitted when the cover  120  is placed on the upper surface of the body  110 . In the case  100 , a pair of left and right arc-shaped guide grooves  101   a  and  101   b  for moving the upper arm  200  in an arc shape in the front-rear direction are formed between end surfaces of the left and right guide plates  118   a  and  118   b  and end surfaces of the left and right guide holes  121   a  and  121   b  with the left and right arm hooks  118   c  and  118   d  interposed between them. The left and right guide grooves  101   a  and  101   b  have a U-shaped cross-sectional shape and are opened in the case  100 . The left and right guide grooves  101   a  and  101   b  are provided along a cylindrical surface coaxially arranged on the X axis. 
     As shown in  FIGS. 1 and 9 , the front and rear guide holes  122   a  and  122   b  are upward convex, bow-shaped notches which are opposed in the front-rear direction in which the front and rear guide plates  119   a  and  119   b  are fitted when the cover  120  is placed on the upper surface of the body  110 . In the case  100 , an arc-shaped rear guide groove  102  for moving the lower arm  300  in an arc shape in the lateral direction is formed between an end surface of the rear guide plates  119   b  and an end surface of the rear guide holes  122   b  with the rear arm hook  119   c  interposed between them. The rear guide groove  102  has a U-shaped cross-sectional shape and is opened in the case  100 . The rear guide groove  102  is provided along a cylindrical surface coaxially arranged on the Y-axis. 
     In the inside of the case  100  configured as described above, a pair of the upper and lower arms  200  and  300 , a lower portion of the operation shaft  400 , the actuating member  500 , the compression coil spring  600 , the first and second sliders  700  and  800 , the pusher  900 , the first and second variable resistors  1000  and  1100 , the pressing switch  1200 , and the substrate  1300  are accommodated. At the same time, an upper portion of the operation shaft  400  projects from the inside of the case  100  to the outside of the case  100  through the opening  121  of the cover  120 . 
     As shown in  FIGS. 1, 5, 6, and 8 to 13 , the substrate  1300  is a rectangular flexible printed circuit (FPC), sandwiched between the lower surface of the body  110  and the bottom plate  131 , and is arranged in a state of being positioned with respect to the body  110 . A circular opening  1310  for exposing the central portion of the bottom plate  131  to the operation shaft accommodation portion  111  is provided at the central portion of the substrate  1300 . The substrate  1300  is provided with a tail portion  1320  for external connection. The tail portion  1320  extends in a band shape from the central portion of a left edge of the substrate  1300  to the left and is pulled out to the left of the case  100 . 
     As shown in  FIGS. 1, 3, 8 to 10, and 11 , the upper arm  200  has an upward convex arch shape (an arc-like shape as viewed from the front-rear direction) made of insulating synthetic resin. The upper arm  200  has an elongated hole  210 , a pair of left and right legs  220   a  and  220   b , a pair of left and right slide parts  230   a  and  230   b , and an engagement protrusion  240 . 
     The elongated hole  210  has a width as wide as a diameter of the operation shaft  400  and is provided in a longitudinal direction (lateral direction) of an arched portion of the upper arm  200 . The arched portion of the upper arm  200  is provided along a cylindrical surface coaxially arranged on the Y-axis. The left and right legs  220   a  and  220   b  are portions extending downward from both left and right ends of the arched portion of the upper arm  200 . The left and right slide parts  230   a  and  230   b  protrude outward from lower ends of the left and right legs  220   a  and  220   b  to the left and right, and are arc-shaped protruding parts when viewed from the lateral direction. The left and right slide parts  230   a  and  230   b  are provided along a cylindrical surface coaxially arranged on the X axis. As shown in  FIG. 11 , the engagement protrusion  240  is a protrusion having an Ω shape in cross section projecting downward from a central portion in the front-rear direction on a lower surface of the left leg  220   a.    
     The upper arm  200  is bridged in the lateral direction at the top of the case  100  by slidably fitting the left and right slide parts  230   a  and  230   b  to the left and right guide grooves  101   a  and  101   b , and in this state, is supported movably in an arc shape in the front-rear direction along the left and right guide grooves  101   a  and  101   b . The upper arm  200  moves along a cylindrical surface coaxially arranged on the X-axis. 
     As shown in  FIGS. 1, 3, 8 to 10 , and  FIGS. 12 to 14 , the lower arm  300  has an upward convex bow shape (a bow shape as viewed from the lateral direction) made of insulating synthetic resin. The lower arm  300  has an elongated hole  310 , a pair of front and rear slide parts  320   a  and  320   b , and an engagement protrusion  330 . 
     The elongated hole  310  has a width as wide as a diameter of the operation shaft  400  and is provided in a longitudinal direction (front-rear direction) of a bow-shaped portion of the lower arm  300 . An upper surface of the bow-shaped portion of the lower arm  300  is provided along a cylindrical surface coaxially arranged on the X-axis. The lower arm  300  has a curved upper surface  300   a  that is formed of the upper surface of the bow-shaped portion, and is provided along a cylindrical surface coaxially arranged on one horizontal axis that passes through the center of curvature of the receiving surface  112   a  and extends in a moving direction (lateral direction) of the lower arm  300 , that is, the X axis. The front and rear slide parts  320   a  and  320   b  project from both front and rear ends of the bow-shaped part of the lower arm  300  to outer sides in the front-rear direction, and are arc-shaped projecting parts as viewed from the front-rear direction. The front and rear slide parts  320   a  and  320   b  are provided along a cylindrical surface coaxially arranged on the Y axis. The front slide part  320   a  is formed thicker than the rear slide part  320   b . As shown in  FIG. 12 , the engagement protrusion  330  is a protrusion having an Ω shape in cross section projecting downward from a central portion in the lateral direction on a lower surface of the rear slide part  320   b.    
     As shown in  FIGS. 9 and 14 , the rear slide part  320   b  is fitted slidably in the rear guide groove  102 , while the front slide part  320   a  is slidably placed on a front arm hook  910  formed of an upper end surface provided along a cylindrical surface coaxially arranged on the Y axis of the pusher  900  in a state where its front end face slidably abuts on an inner surface of the front guide plate  119   a , so that the lower arm  300  is bridged in the front-rear direction in a state of being orthogonal to the upper arm  200  right below the upper arm  200  in the case  100 , and in that state, the lower arm  300  is supported movably in an arc shape in the lateral direction along the rear guide groove  102 . The lower arm  300  moves along a cylindrical surface coaxially arranged on the Y axis. 
     In the lower arm  300 , a front slide part  310   a  on a front end side of the lower arm  300  can be pressed and moved downward with a rear slide part  320   b  on a rear end side of the lower arm  300  as a fulcrum, by a slight gap (clearance) between the rear slide part  320   b  and the rear guide groove  102 . 
     As described above, a pair of the upper and lower arms  200  and  300  are supported movably in two directions orthogonal to each other in the case  100  having the bottom plate  131 , and each has the elongated holes  210  and  310  extending in a direction orthogonal to a moving direction. 
     As shown in  FIGS. 1 to 5  and  FIGS. 7 to 10 , the operation shaft  400  is a round rod-shaped member made of insulating synthetic resin having a diameter that is the same as a width of the elongated holes  210  and  310  of the upper and lower arms  200  and  300 . The operation shaft  400  is arranged in the case  100  in a state where, as a middle portion in an axial direction of the operation shaft  400  penetrates the elongated holes  210  and  310  of the upper and lower arms  200  and  300 , an upper end portion of the operation shaft  400  protruding above the upper arm  200  is inserted through the opening  121  of the cover  120  and protrudes to the outside of the case  100 , and a lower end portion of the operation shaft  400  protruding downward of the lower arm  300  is inserted through an inner diameter of the receiving portion  112  of the body  110  and inserted into the operation shaft accommodation portion  111  of the body  110 . 
     The operation shaft  400  has the spherical trapezoidal portion  410  for rotatably supporting the lower end of the operation shaft  400  while also serving to prevent the operation shaft  400  from coming off, a stepped shaft hole  420  for supporting the actuating member  500  in the lower end of the operation shaft  400  so as to be movable in the axial direction of the operation shaft  400  in a state in which rotation around the axis of the operation shaft  400  is restricted, and also for providing the compression coil spring  600  between the operation shaft  400  and the actuating member  500 , a pair of left and right engaging portions  430   a  and  430   b  for pressing and moving the lower arm  300  at the time of pressing and moving the operation shaft  400 , an attaching hole  440  for screwing, for example, a disk-like key top, at the upper end of the operation shaft  400 , and a two-sided cut portion  450  for locking the key top. 
     The spherical trapezoidal portion  410  is arranged in the operation shaft accommodation portion  111  of the case  100 . The spherical trapezoidal portion  410  is formed in an upward convex spherical trapezoidal shape, in which the diameter decreases upward, in the lower end portion of the operation shaft  400 , a radius of an upper surface of the spherical trapezoidal portion  410  is equal to a radius of the operation shaft  400 , and the spherical zone  411  of a side surface portion of the spherical trapezoidal portion  410  can be fitted to the receiving surface  112   a  of the receiving portion  112  of the case  100  from below. 
     The stepped shaft hole  420  is provided coaxially with the operation shaft  400  in an axial center portion of the operation shaft  400 , and has a ceiled hole opened on a lower end surface (lower end surface of the operation shaft  400 ) of the spherical trapezoidal portion  410 . The stepped shaft hole  420  has, from bottom to top, a shaft hole  421  having a rectangular cross section, a shaft hole  422  having a rectangular cross section smaller (having a smaller diameter) and longer than the shaft hole  421 , a shaft hole  423  having a circular cross section that has the same diameter as the shaft hole  422 , the same length as the shaft hole  422 , and is capable of accommodating the compression coil spring  600 , and a shaft hole  424  having a circular cross section that has a diameter smaller than the shaft hole  423  and is shorter than the shaft hole  423 . Downward step surfaces  425 ,  426 , and  427  are provided between the shaft hole  421  and the shaft hole  422 , between the shaft hole  422  and the shaft hole  423 , and between the shaft hole  423  and the shaft hole  424 , respectively. 
     As shown in  FIGS. 1, 9, and 14 , the left and right engaging portions  430   a  and  430   b  are protrusions having a right-angled triangular cross-section projecting toward the left and right sides from an outer surface of the middle portion in the axial direction of the operation shaft  400  in the elongated hole  210  of the upper arm  200 , and have engaging surfaces  431   a  and  431   b  facing each other with a slight gap (clearance) from above on left and right side edge portions of the elongated hole  310  in the curved upper surface  300   a  of the lower arm  300  in a bottom portion of the left and right engaging portions  430   a  and  430   b . The engaging surfaces  431   a  and  431   b  are provided along a cylindrical surface coaxially arranged on the X axis, and are engaging surfaces facing downward that are curved along the curved upper surface  300   a  of the lower arm  300 , are movable on a curved upper surface of the lower arm  300  when the operation shaft  400  rotates, and move the lower arm  300  along with the pressing movement of the operation shaft  400 . 
     The attaching hole  440  is a bottomed hole provided coaxially with the operation shaft  400  in the axial center portion of the operation shaft  400  and opened on the upper end surface of the operation shaft  400 . The two-sided cut portion  450  is provided at the upper end of the operation shaft  400 , and the upper end of the operation shaft  400  is formed in a shaft portion having an oblong cross section and a two-surface width. 
     As shown in  FIGS. 1, 6 , and  FIGS. 8 to 10 , the actuating member  500  is made of insulating synthetic resin, and has a spherical trapezoidal portion  510 , a stepped shaft portion  520 , and a protrusion  530 . 
     The spherical trapezoidal portion  510  is provided at the lower end of the actuating member  500 , and is placed in the central portion of the bottom plate  131  exposed in the operation shaft accommodation portion  111  of the case  100 . The spherical trapezoidal portion  510  is formed in a downward convex spherical shape whose diameter decreases downward. When the operation shaft  400  is rotated about the center of curvature of the receiving surface  112   a  of the receiving portion  112  of the case  100  from a neutral state shown in  FIGS. 8 to 10  in which the shaft direction is perpendicular to the bottom plate  131  of the case  100 , that is, tilted in an optional direction around the operation shaft  400  from the neutral state, a spherical zone  511  of a side surface portion of the spherical trapezoidal portion  510  abuts against the bottom plate  131  of the case  100  as shown in  FIG. 17 , and, when the operation shaft  400  is returned to the neutral state, a flat lower surface  512  of the spherical trapezoidal portion  510  abuts against the bottom plate  131  of the case  100  as shown in  FIGS. 8 to 10 . 
     The stepped shaft portion  520  is vertically provided at the center of the upper surface of the spherical trapezoidal portion  510 , and is inserted in the shaft hole  420  of the operation shaft  400  so as to be movable in the axial direction of the operation shaft  400 . The shaft portion  520  includes, from bottom to top, a square shaft portion  521  having a square cross section fitted in the shaft hole  421 , a square shaft portion  522  having a square cross section fitted in the shaft hole  422 , and a round shaft portion  523  having a circular cross section that is inserted into the shaft hole  423  together with the compression coil spring  600  in a state of being inserted into an inner diameter of the compression coil spring  600  and has an upper end portion as a spring guide fitted in the shaft hole  424 . Upward step surfaces  524  and  525  are provided between the square shaft portion  521  and the square shaft portion  522  and between the square shaft portion  522  and the round shaft portion  523 , respectively. 
     The actuating member  500  is provided with the downward convex spherical trapezoidal portion  510  whose diameter decreases downward at the lower end of the shaft portion  520 , and the shaft portion  520  is movably inserted and arranged in the shaft hole  420  of the operation shaft  400  in the axial direction of the operation shaft  400 , so that the downward convex spherical trapezoidal portion  510  is movably supported in the axial direction of the operation shaft  400  directly below the upward convex spherical trapezoidal portion  410  provided at the lower end of the operation shaft  400  with the shaft portion  520  interposed between them. 
     The compression coil spring  600  is made of a metal wire, and, as shown in  FIGS. 8 to 10 , is inserted into the shaft hole  420  of the operation shaft  400  together with the shaft portion  520  of the actuating member  500  in a state of being fitted to the outer periphery of the round shaft portion  523  of the shaft portion  520  of the actuating member  500  to be accommodated in the shaft hole  423 . Upper and lower wound ends are respectively brought into contact with the downward step surface  427  of the shaft hole  420  and the upward step surface  525  of the shaft portion  520 , so as to bias the actuating member  500  downward along the axial direction of the operation shaft  400  in such a manner as pressing the spherical zone  511  and the lower surface  512  of the spherical trapezoidal portion  510  of the actuating member  500  against the bottom plate  131  of the case  100  from above, and to bias the operation shaft  400  upward along the axial direction in such a manner as pressing the spherical zone  411  of the spherical trapezoidal portion  410  of the operation shaft  400  from below against the receiving surface  112   a  of the receiving portion  112  of the case  100  from below. 
     As described above, as shown in  FIGS. 8 to 10 , the operation shaft  400  is rotatable in a state of penetrating the elongated holes  210  and  310  of the upper and lower arms  200  and  300 . By the compression coil spring  600 , the spherical trapezoidal portion  510  of the actuating member  500  is pressed against the bottom plate  131  of the case  100  from above, and the spherical zone  411  of the spherical trapezoidal portion  410  of the operation shaft  400  is pressed against the receiving surface  112   a  of the receiving portion  112  of the case  100  from below. In this manner, while being in a state of being prevented from coming off by the receiving portion  112  of the case  100 , the operation shaft  400  is supported so as to be rotatable about the center of curvature of the receiving surface  112   a  of the receiving portion  112  of the case  100  together with the actuating member  500 , and so as to be able to be pressed and movable in the axial direction. 
     The first slider  700  is made of insulating synthetic resin. The first slider  700  has, as shown in  FIGS. 8 and 11 , a first slider main body  710 , a first engagement piece  720 , a first engagement groove  730 , a first engagement protrusion  740 , a first movable surface  750 , and a first convex portion  760 . The first slider main body  710  is a cuboid shaped block. The first engagement piece  720  is provided upright at the center of a flat upper surface of the first slider main body  710 . The first engagement groove  730  is provided at the upper end of the first engagement piece  720 . The first engagement protrusion  740  is a cylinder that projects downward from the central portion of the flat lower surface of the first slider main body  710 . 
     The first slider  700  is arranged in the first slider accommodation portion  114  so as to be movable in the front-rear direction in a state where the first slider main body  710  is accommodated in the first lower movement path  114   a , the first engagement piece  720  is inserted through the first upper movement path  114   c , and the upper end of the first engagement piece  720  projects to the inside of the cover  120 . Further, when the engagement protrusion  240  of the upper arm  200  is engaged with the first engagement groove  730  and the upper arm  200  moves in an arc shape in the front-rear direction, the first engagement piece  720  is pressed against the engagement protrusion  240  of the upper arm  200 , so that the first slider  700  is movable in the front-rear direction. 
     The first movable surface  750  is a flat upper surface of the first slider main body  710 . The first movable surface  750  faces the first fixing surface  114   b  of the first slider accommodation portion  114 , and is slidable in the front-rear direction along the first fixing surface  114   b  in a state of being elastically pressed against the first fixing surface  114   b  by an elastic force of a first contact described later. The first convex portion  760  is fitted to the first concave portion  114   d  provided in the first slider accommodation portion  114  when the first slider  700  is positioned at the neutral position. One of the first convex portion  760  is provided on each of the first movable surface  750  located closer to the front side relative to the first engagement piece  720  and the first movable surface  750  located closer to the rear side relative to the first engagement piece  720 . A fitting shape of the first convex portion  760  with the first concave portion  114   d  is a cylindrical surface formed in a cylindrical surface extending in the lateral direction orthogonal to a moving direction (front-rear direction) of the first slider  700 , and has an upward convex arc-like cross-sectional shape. 
     The second slider  800  is made of insulating synthetic resin. The second slider  800  has, as shown in  FIGS. 9 and 12 , a second slider main body  810 , a second engagement piece  820 , a second engagement groove  830 , a second engagement protrusion  840 , a second movable surface  850 , and a second convex portion  860 . The second slider main body  810  is a cuboid block. The second engagement piece  820  is provided upright at the center of the flat upper surface of the second slider main body  810 . The second engagement groove  830  is provided at the upper end of the second engagement piece  820 . The second engagement protrusion  840  is a cylinder that projects downward from the central portion of the flat lower surface of the second slider main body  810 . 
     The second slider  800  is arranged in the second slider accommodation portion  115  so as to be movable in the lateral direction in a state where the second slider main body  810  is accommodated in the second lower movement path  115   a , the second engagement piece  820  is inserted through the second upper movement path  115   c , and the upper end of the second engagement piece  820  projects to the inside of the cover  120 . Further, when the engagement protrusion  330  of the lower arm  300  is engaged with the second engagement groove  830  and the lower arm  300  moves in an arc shape in the lateral direction, the second engagement piece  820  is pressed against the engagement protrusion  330  of the lower arm  300 , so that the second slider  800  is movable in the lateral direction. 
     The second movable surface  850  is a flat upper surface of the second slider main body  810 . The second movable surface  850  faces the second fixing surface  115   b  of the second slider accommodation portion  115 , and is slidable in the lateral direction along the second fixing surface  115   b  in a state of being elastically pressed against the second fixing surface  115   b  by an elastic force of a second contact described later. The second convex portion  860  is fitted to the second concave portion  115   d  provided in the second slider accommodation portion  115  when the second slider  800  is positioned at the neutral position, and is provided on each of the second movable surface  850  located closer to the front side relative to the second engagement piece  820  and the second movable surface  850  located closer to the rear side relative to the second engagement piece  820 . A fitting shape of the second convex portion  860  with the second concave portion  115   d  is a cylindrical surface formed in a cylindrical surface extending in the front-rear direction orthogonal to a moving direction (front-rear direction) of the second slider  800 , and has an upward convex arc-like cross-sectional shape. 
     The first variable resistor  1000  can detect a moving direction and a movement amount of the upper arm  200  by detecting a moving direction and a movement amount of the first slider  700  as a change in a resistance value. The first variable resistor  1000  has a first contact  1010  and a first resistance circuit  1020  as shown in  FIGS. 1, 6, and 11 . The first resistance circuit  1020  is formed on the substrate  1300 . The first contact  1010  is a metal plate spring piece. The first contact  1010  is fixed to the lower surface of the first slider main body  710  with the first engagement protrusion  740  interposed between them. The first contact  1010  is in contact with the first resistance circuit  1020  and makes the first resistance circuit  1020  conductive. The first contact  1010  is slidable on the first resistance circuit  1020  according to the movement of the first slider  700  in the front-rear direction. As the first contact  1010  slides on the first resistance circuit  1020  in this manner, a resistance value of the first variable resistor  1000  changes. 
     The second variable resistor  1100  can detect a moving direction and a movement amount of the lower arm  300  by detecting a moving direction and a movement amount of the second slider  800  as a change in a resistance value. The second variable resistor  1100  has a second contact  1110  and a second resistance circuit  1120  as shown in  FIGS. 1, 6, and 12 . The second resistance circuit  1120  is formed on the substrate  1300 . The second contact  1110  is a metal plate spring piece. The second contact  1110  is fixed to the lower surface of the second slider main body  810  with the second engagement protrusion  840  interposed between them. The second contact  1110  is in contact with the second resistance circuit  1120  and makes the second resistance circuit  1120  conductive. The second contact  1110  is slidable on the second resistance circuit  1120  according to the movement of the second slider  800  in the lateral direction. As the second contact  1110  slides on the second resistance circuit  1120  in this manner, a resistance value of the second variable resistor  1100  changes. 
     The pressing switch  1200  detects a pressing movement of the operation shaft  400 . The pressing switch  1200  has a metal dome sheet  1210  and a switch circuit  1220  as shown in  FIGS. 1, 5, 6, 9, and 13 . The metal dome sheet  1210  has a cover sheet  1211  and a metal dome  1212 . The cover sheet  1211  is a single-sided adhesive sheet. The metal dome  1212  is a movable contact made of an upward convex dome-shaped metal plate, and, as shown in  FIG. 14 , biases the pusher  900  upward. The upper surface of the metal dome  1212  is adhered to the lower surface of the cover sheet  1211  to form the metal dome sheet  1210 . The switch circuit  1220  has a central fixed contact  1221  and an outer fixed contact  1222 . The central fixed contact  1221  has a circular shape and is formed on the upper surface of the substrate  1300  which is the lower surface of the pressing switch accommodation portion  116 . The central fixed contact  1221  is arranged immediately below the pusher accommodation portion  117 . The outer fixed contact  1222  is formed in the shape of a horseshoe to surround the central fixed contact  1221  with space and is formed on the upper surface of the substrate  1300 . 
     In the pressing switch  1200 , the metal dome sheet  1210  is adhered to the upper surface of the substrate  1300 , which is the lower surface of the pressing switch accommodation portion  116 , the metal dome  1212  is fixed on the outer fixed contact  1222  across the central fixed contact  1221 , both ends in the lateral direction of the metal dome  1212  are in contact with the outer fixed contact  1222 , and the top of the metal dome  1212  is separated from and faces the central fixed contact  1221  immediately below with a gap between them. 
     The pusher  900  is a drive member for transmitting a pressing movement of the operation shaft  400  to the top of the metal dome  1212  together with the lower arm  300 . As shown in  FIGS. 1, 5, 9, 13, and 14 , the pusher  900  is formed of insulating synthetic resin in a rectangular plate shape, and has a front arm hook  910  on which the front slide part  320   a  of the lower arm  300  is placed slidably and a pressing portion  920  for pressing the pressing switch  1200 . The pusher  900  is vertically movably supported in the case  100 . The pusher  900  is vertically movably fitted and held in the pusher accommodation portion  117 , and while the upper end of the pusher  900  projects to the inner surface side of the front guide plate  119   a  to face the rear guide plate  119   b , the lower end surface of the pusher  900  is exposed to the inside of the pressing switch accommodation portion  116  to face the metal dome sheet  1210 . The front arm hook  910  is provided along a cylindrical surface coaxially arranged on the Y-axis, and is formed of an upper end surface of the upward convex arc-shaped curved pusher  900 . The pressing portion  920  is a conical boss provided at the center of the lower end surface of the pusher  900  and having a diameter decreasing downward, and the lower end surface abuts on the top of the metal dome sheet  1210  corresponding to the top of the metal dome  1212 . The pusher  900  is interposed between the front slide part  320   a  of the lower arm  300  and the pressing switch  1200 . 
     Next, the operation of the multi-directional input device according to the embodiment of the present invention will be described. 
     First, when no operating force is applied to the upper end of the operation shaft  400 , as shown in  FIGS. 8 and 9 , the flat lower surface  512  of the downward convex spherical trapezoidal portion  510  of the actuating member  500  is pressed against the bottom plate  131  of the case  100  by a biasing force (elastic force) of the compression coil spring  600  so as to be in a horizontal state with respect to the bottom plate  131 , and the operation shaft  400  is held in a neutral state where the axial direction of the operation shaft  400  is perpendicular to the bottom plate  131  of the case  100 . 
     When the upper end of the operation shaft  400  in the neutral state is pressed in the left direction along the elongated hole  210  of the upper arm  200 , the operation shaft  400  rotates around the center of curvature of the receiving surface  112   a  of the receiving portion  112  of the case  100  together with the actuating member  500  and tilts left along the elongated hole  210  of the upper arm  200  in a state where the operation shaft  400  is prevented from coming off by the receiving portion  112  of the case  100  as shown in  FIGS. 16 and 17 . 
     Then, an arched portion of the lower arm  300  is pressed in the left direction orthogonal to the longitudinal direction of the elongated hole  310  by the operation shaft  400 , and the lower arm  300  is guided by the rear guide groove  102  of the case  100  to move leftward in an arc shape. At this time, since the operation shaft  400  moves leftward in the elongated hole  210  of the upper arm  200 , the upper arm  200  and the first slider  700  are held at their neutral positions (initial positions). 
     On the other hand, with the movement of the lower arm  300 , the second engagement piece  820  of the second slider  800  is pressed against the engagement protrusion  330  of the lower arm  300 , and the second slider  800  is guided to the second slider accommodation portion  115  to move in the inside of the second slider accommodation portion  115  to the left. 
     At this time, the second convex portion  860  provided on the second slider  800  comes off the second concave portion  115   d  provided on the second slider accommodation portion  115  of the case  100  against the elastic force of the second contact  1110  of the second variable resistor  1100 , and moves under the flat second fixing surface  115   b  located on the left side of the second concave portion  115   d.    
     Then, when the second contact  1110  of the second variable resistor  1100  slides on the second resistance circuit  1120  as the second slider  800  moves, a resistance value of the second variable resistor  1100  changes. In this manner, the second variable resistor  1100  detects a moving direction and a movement amount of the second slider  800  as a moving direction and a movement amount of the lower arm  300 . These are input from the tail portion  1320  of the substrate  1300  to a control unit of an electronic device via a connector and detected as a rotating direction and a rotation amount of the operation shaft  400  by the control unit. 
     When the pressing of the operation shaft  400  is released, the operation shaft  400  returns to the neutral state together with the actuating member  500  while the flat lower surface  512  of the downward convex spherical trapezoidal portion  510  of the actuating member  500  is returned to the horizontal state by the biasing force of the compression coil spring  600 . 
     When the operation shaft  400  returns to the neutral state, the lower arm  300  returns to the neutral position, and when the lower arm  300  returns to the neutral position, the second slider  800  returns to the neutral position. 
     At this time, the second slider  800  is moved so as to be guided to the neutral position immediately before its movement to the neutral position while the second concave portion  115   d  and the second convex portion  860  are fitted by the elastic force of the second contact  1110  of the second variable resistor  1100 , and the second slider  800  is accurately returned to its neutral position without error while parts manufacturing tolerance and the like are absorbed. 
     Further, when the upper end of the operation shaft  400  in the neutral state is pressed in the front direction along the elongated hole  310  of the lower arm  300 , the operation shaft  400  rotates around the center of curvature of the receiving surface  112   a  of the receiving portion  112  of the case  100  together with the actuating member  500  and tilts front along the elongated hole  310  of the lower arm  300  in a state where the operation shaft  400  is prevented from coming off by the receiving portion  112  of the case  100 . 
     Then, the arched portion of the upper arm  200  is pressed forward by the operation shaft  400 , and the upper arm  200  is guided by the left and right guide grooves  101   a  and  101   b  of the case  100  to move in an arc shape in the front direction. At this time, since the operation shaft  400  moves in the front direction in the elongated hole  310  of the lower arm  300 , the lower arm  300  and the second slider  800  are held at their neutral positions (initial positions). 
     On the other hand, with the movement of the upper arm  200 , the first engagement piece  720  of the first slider  700  is pressed against the engagement protrusion  240  of the upper arm  200 , and the first slider  700  is guided to the first slider accommodation portion  114  to move in the inside of the first slider accommodation portion  114  in the front direction. 
     At this time, the first convex portion  760  provided on the first slider  700  comes off the first concave portion  114   d  provided on the first slider accommodation portion  114  of the case  100  against the elastic force of the first contact  1010  of the first variable resistor  1000 , and moves under the flat first fixing surface  114   b  located on the front side of the first concave portion  114   d.    
     Then, when the first contact  1010  of the first variable resistor  1000  slides on the first resistance circuit  1020  as the first slider  700  moves, a resistance value of the first variable resistor  1000  changes. In this manner, the first variable resistor  1000  detects a moving direction and a movement amount of the first slider  700  as a moving direction and a movement amount of the upper arm  200 . These are input from the tail portion  1320  of the substrate  1300  to a control unit of an electronic device via a connector and detected as a rotating direction and a rotation amount of the operation shaft  400  by the control unit. 
     When the pressing of the operation shaft  400  is released, the operation shaft  400  returns to the neutral state together with the actuating member  500  while the flat lower surface  512  of the downward convex spherical trapezoidal portion  510  of the actuating member  500  is returned to the horizontal state by the biasing force of the compression coil spring  600 . 
     When the operation shaft  400  returns to the neutral state, the upper arm  200  returns to the neutral position, and when the upper arm  200  returns to the neutral position, the first slider  700  returns to the neutral position. 
     At this time, the first slider  700  is moved so as to be guided to the neutral position immediately before its movement to the neutral position while the first concave portion  114   d  and the first convex portion  760  are fitted by the elastic force of the first contact  1010  of the first variable resistor  1000 , and the first slider  700  is accurately returned to its neutral position without error while parts manufacturing tolerance and the like are absorbed. 
     Furthermore, in a state of being prevented from coming off by the receiving portion  112  of the case  100 , the operation shaft  400  can rotate (tilt) around the center of curvature of the receiving surface  112   a  of the receiving portion  112  of the case  100  together with the actuating member  500  in all directions 360° around the operation shaft  400 , and, in a tilting state, the operation shaft  400  can rotate by changing a tilt position in a direction along the opening  121  of the cover  120 . 
     At this time, an end of each of the protrusions  530  of the actuating member  500  moves in the vertical direction in the guide groove  113  of the case  100 , and the spherical zone  511  of the downward convex spherical trapezoidal portion  510  of the actuating member  500  comes into rolling contact with the bottom plate  131  of the case  100  without slipping. 
     Further, when the upper end of the operation shaft  400  is pressed downward, the operation shaft  400  is pressed down to separate the spherical zone  411  of the spherical trapezoidal portion  410  of the operation shaft  400  from the receiving surface  112   a  of the receiving portion  112  of the case  100  while pressing the shaft portion  520  of the actuating member  500  into the shaft hole  420  of the operation shaft  400  against the compression coil spring  600 . The left and right sided edge portions of the elongated hole  310  on the curved upper surface  300   a  of the lower arm  300  are pressed downward by the left and right engaging surfaces  431   a  and  431   b  of the left and right engaging portions  430   a  and  430   b  of the operation shaft  400 . 
     In this manner, the front slide part  310   a  on the front end side of the lower arm  300  slidably mounted on the upper end surface (front arm hook  910 ) of the pusher  900  is pressed and moved with the rear slide part  320   b  on the rear end side of the lower arm  300  slidably fitted in the rear guide groove  102  of the case  100  as a fulcrum. Along with the above, the pusher  900  moves downward. 
     Then, with the downward movement of the pusher  900 , the top of the metal dome  1212  of the pressing switch  1200  is pressed down by the pressing portion  920  of the pusher  900 , the top of the metal dome  1212  is elastically deformed in a downward convex shape with a click feeling and comes into contact with the central fixed contact  1221  of the switch circuit  1220  of the pressing switch  1200 , and a switch-on state in which the central fixed contact  1221  and the outer fixed contact  1222  are electrically connected via the metal dome  1212  is established, so that the pressing movement of the operation shaft  400  is detected. 
     At this time, the lower arm  300  functions as a “lever”, and a fulcrum (the rear slide part  320   b  of the lower arm  300 ) is placed in a location that is on an outer side of a force application point (the left and right engaging portions  430   a  and  430   b  of the operation shaft  400 ) and an action point (the front slide part  310   a  of the lower arm  300 ) and close to the force application point, so that a small movement applied to the force application point becomes a large movement at the action point and a smaller force than the applied force is transmitted. In this manner, a pressing movement amount of the operation shaft  400  for operating the pressing switch  1200  can be reduced, and an excellent click feeling can be obtained. 
     When the pressing of the operation shaft  400  is released, the operation shaft  400  is pressed up and moved so as to press the spherical zone  411  of the spherical trapezoidal portion  410  of the operation shaft  400  against the receiving surface  112   a  of the receiving portion  112  of the case  100  while the shaft portion  520  of the actuating member  500  is pulled out from the shaft hole  420  of the operation shaft  400  by the biasing force of the compression coil spring  600 , and returns to the state before the pressing movement. 
     On the other hand, the top of the metal dome  1212  returns to the original upward convex shape. Along with the above, the top of the metal dome  1212  is separated from the central fixed contact  1221  of the switch circuit  1220 , and a switch-off state in which the central fixed contact  1221  and the outer fixed contact  1222  are electrically disconnected is established. The biasing force of the metal dome  1212  causes the pusher  900  to move upward and return to the original position, and the lower arm  300  returns to the original horizontal state accordingly. 
     As described above, the multi-directional input device according to an embodiment of the present invention includes the case  100  having the bottom plate  131 , a pair of the upper and lower arms  200  and  300  supported to be movable in two orthogonal directions in the inside of the case  100 , the arms having the elongated holes  210  and  310  extending in a direction orthogonal to a moving direction, the operation shaft  400  that is rotatable in a state of penetrating the elongated holes  210  and  310 , the actuating member  500  that is supported so as to be movable in an axial direction of the operation shaft  400  at a lower end of the operation shaft  400  projecting downward of the lower arm  300 , and is provided with the downward convex spherical trapezoidal portion  510  whose diameter decreases downward, the compression coil spring  600  that is provided between the operation shaft  400  and the actuating member  500 , and presses the downward convex spherical trapezoidal portion  510  against the bottom plate  131  to return the operation shaft  400  to a neutral state, and a plurality of the electric components  1000  and  1100  operated via the arms  200  and  300  by rotation of the operation shaft  400 . An upward convex spherical trapezoidal portion  410  whose diameter decreases upward is provided at a lower end of the operation shaft  400  projecting downward of the lower arm  300 . The receiving portion  112  for the upward convex spherical trapezoidal portion  410  is provided in the case  100 . The receiving portion  112  has the receiving surface  112   a  that is configured with a spherical surface having the same radius of curvature as radius of curvature of the spherical zone  411  of the upward convex spherical trapezoidal portion  410 , the receiving surface  112   a  against which the spherical zone  411  of the upward convex spherical trapezoidal portion  410  is pressed from downward by the compression coil spring  600 . The operation shaft  400  is supported to be rotatable about the center of curvature of the receiving surface  112   a.  In this manner, since the operation shaft  400  is supported so as to be rotatable about the curvature center of the receiving surface  112   a  of the receiving portion  112  while being prevented from coming off by the receiving portion  112  positioned downward of the lower arm  300 , the entire height of the device is reduced even if the rotation radius of the operation shaft  400  is increased, and the device can be downsized without lowering the strength of the operation shaft  400  and the lower arm  300 . 
     Further, the case  100  having the bottom plate  131 , a pair of the upper and lower arms  200  and  300  supported so as to be movable in two orthogonal directions in the inside of the case  100 , the arms having the elongated holes  210  and  310  extending in a direction orthogonal to a moving direction, the operation shaft  400  that is rotatable in a state of penetrating the elongated holes  210  and  310 , the actuating member  500  that is supported so as to be movable in an axial direction of the operation shaft  400  at a lower end of the operation shaft  400  projecting downward of the lower arm  300 , and is provided with the downward convex spherical trapezoidal portion  510  whose diameter decreases downward, the compression coil spring  600  that is provided between the operation shaft  400  and the actuating member  500 , and presses the downward convex spherical trapezoidal portion  510  against the bottom plate  131  to return the operation shaft  400  to a neutral state, and a plurality of the electric components  1000  and  1100  operated via the arms  200  and  300  by rotation of the operation shaft  400  are included. The actuating member  500  is supported at a lower end of the operation shaft  400  in a state of reducing rotation around an axis of the operation shaft  400  and is provided with the protrusion  530  projecting radially outward from an upper end of the downward convex spherical trapezoidal portion  510 . The protrusion  530  is inserted to be movable vertically in the guide groove  113  that extends in the vertical direction on an inner wall of the case  100 , so that rotation around an axis of the operation shaft  400  of the actuating member  500  is reduced. In this manner, rotation around an axis of the operation shaft  400  is reduced via the actuating member  500 . Therefore, degree of freedom in a shape of the lower arm  300  is increased, the lower arm  300  can be downsized, and the device can be downsized. 
     Further, the case  100  having the bottom plate  131 , a pair of the upper and lower arms  200  and  300  supported so as to be movable in two orthogonal directions in the inside of the case  100 , the arms having the elongated holes  210  and  310  extending in a direction orthogonal to a moving direction, the operation shaft  400  that is rotatable in a state of penetrating the elongated holes  210  and  310 , the actuating member  500  that is supported so as to be movable in an axial direction of the operation shaft  400  at a lower end of the operation shaft  400  projecting downward of the lower arm  300 , and is provided with the downward convex spherical trapezoidal portion  510  whose diameter decreases downward, the compression coil spring  600  that is provided between the operation shaft  400  and the actuating member  500 , and presses the downward convex spherical trapezoidal portion  510  against the bottom plate  131  to return the operation shaft  400  to a neutral state, and a plurality of the electric components  1000  and  1100  operated via the arms  200  and  300  by rotation of the operation shaft  400  are included. The upward convex spherical trapezoidal portion  410  whose diameter decreases upward is provided at a lower end of the operation shaft  400  projecting downward of the lower arm  300 . The receiving portion  112  for the upward convex spherical trapezoidal portion  410  is provided in the case  100 . The receiving portion  112  has the receiving surface  112   a  that is configured with a spherical surface having the same radius of curvature as radius of curvature of the spherical zone  411  of the upward convex spherical trapezoidal portion  410 , the receiving surface against which the spherical zone  411  of the upward convex spherical trapezoidal portion  410  is pressed from downward by the compression coil spring  600 . The operation shaft  400  is supported so as to be rotatable about the center of curvature of the receiving surface  112   a . The lower arm  300  has the curved upper surface  300   a  provided along a cylindrical surface arranged coaxially on one horizontal axis (X axis) that passes through the center of curvature of the receiving surface  112   a  and extends in a moving direction of the lower arm  300 . The operation shaft  400  is provided with the engaging portions  430   a  and  430   b  with the lower arm  300 . The engaging portions  430   a  and  430   b  have the downward engaging surfaces  431   a  and  431   b  that are curved along the curved upper surface  300   a  of the lower arm  300  and are movable on the curved upper surface  300   a  of the lower arm  300  when the operation shaft  400  rotates. In this manner, the operation shaft  400  in a state of being inserted through the elongated hole  310  of the lower arm  300  from downward is rotated by 90° so that the downward engaging surfaces  431   a  and  431   b  of the engaging portions  430   a  and  430   b  of the operation shaft  400  are arranged to face the curved upper surface  300   a  of the lower arm  300  for assembly. Accordingly, the operation shaft  400  and the lower arm  300  can be provided with enough strength, and the device can be downsized without lowering of the strength of the operation shaft  400  and the lower arm  300 . 
     Note that, in a case where the pressing switch  1200  is not included, the lower arm  300  does not have to be moved downward, and the pusher  900  does not have to be included. Therefore, in the lower arm  300 , while the rear slide part  320   b  is slidably fitted into the rear guide groove  102 , the front slide part  320   a  is slidably fitted to a front guide groove that is formed between an end surface of the front guide plate  119   a  provided with a front arm hook, which is provided in the front guide plate  119   a  in place of the front arm hook  910  formed of the upper end surface of the pusher  900 , and an end surface of the front guide hole  122   a  of the cover  120 . In this manner, the lower arm  300  is bridged in the front-rear direction at a right angle to the upper arm  200  directly below the upper arm  200  in the case  100 , and, in this state, is supported to be movable in an arc shape in the lateral direction along the front and rear guide grooves  102 , and can move along a cylindrical surface coaxially arranged on the Y axis. Then, in a case where the pressing switch  1200  is not included, the engaging portions (the engaging portions  430   a  and  430   b  and the curved upper surface  300   a ) of the operation shaft  400  and the lower arm  300  prevent the operation shaft  400  from moving downward needlessly. 
     Further, the pusher  900  supported movably in the vertical direction and the pressing switch  1200  for detecting the pressing movement of the operation shaft  400  are further included in the case  100 , the lower arm  300  moving downward with the pressing movement of the operation shaft  400  moves downward the pusher  900 , and the pressing switch  1200  is operated via the pusher  900 . In this manner, before the pusher  900  is incorporated, the lower arm  300  has degree of freedom in a downward direction, and there is no possibility of interference between the downward engaging surfaces  431   a  and  431   b  of the engaging portions  430   a  and  430   b  of the operation shaft  400  and the curved upper surface  300   a  of the lower arm  300  even if the operation shaft is rotated by 90° and assembled. For this reason, a gap (clearance) between them is sufficiently reduced, and the pressing switch  1200  can be operated with a short stroke. 
     In the description of the multi-directional input device according to one embodiment of the present invention, a fitting shape between the shaft hole  420  of the operation shaft  400  and the shaft portion  520  of the actuating member  500  is a polygon as a section for locking the axial movement of the operation shaft  400  between the operation shaft  400  and the actuating member  500 . However, spline fitting may be employed.