Patent Publication Number: US-2023162557-A1

Title: Pushbutton switch, pushbutton switch unit, operating unit, and amusement machine

Description:
FIELD 
     The present invention relates to a pushbutton switch, a pushbutton switch unit, an operating unit, and an amusement machine. 
     BACKGROUND 
     Patent Literature 1 describes a known pushbutton assembly. The pushbutton assembly described in Patent Literature 1 includes a display and at least one pushbutton switch. The display includes a transparent material on its display surface to support the pushbutton switch. The transparent material is a support for the pushbutton switch. 
     CITATION LIST 
     Patent Literature 
     
         
         Patent Literature 1: U.S. patent Ser. No. 10/431,037 
       
    
     SUMMARY 
     Technical Problem 
     In the pushbutton assembly described in Patent Literature 1, the pushbutton switch is received in an attachment opening in the transparent material. However, the structure with an opening may lower the strength of the transparent material. The pushbutton switch may be included in a machine such as an amusement machine and operated by a user with strong force. In this case, in particular, the transparent material may fracture with cracks extending from the opening. 
     The inventor has developed a pushbutton switch including an operable portion attached to one surface of a transparent material and a detector attached to the other surface of the transparent material. The operable portion includes a press portion to be operated by a user. The detector detects the pressed state of the press portion. The pushbutton switch is installable on the transparent material without an attachment opening. The pushbutton switch includes consumable components, specifically the press portion or other moving components, or components that support these components. Such components are to be replaceable. 
     The pushbutton switch is thus to allow easy attachment and removal of the operable portion. The operable portion may be attachable and removable at the front surface of the transparent material to facilitate replacement. In this case, however, the operable portion is to be prevented from being removed by the user with, for example, ill intentions. 
     In response to the above issue, an aspect of the present invention is directed to a technique for preventing an operable portion from being removed from a pushbutton switch by a person other than the manager. 
     Solution to Problem 
     A switch, a unit, and a machine according to one or more aspects of the present invention have the structures described below. A pushbutton switch according to an aspect of the present invention includes an attachment fixed to one surface of a support being a plate, an operable portion removably engaged with the attachment, and a detector attached to another surface of the support and facing the operable portion. The operable portion includes a press portion and a movable magnet movable in a pressing direction from the operable portion toward the detector and in a direction opposite to the pressing direction. The operable portion is rotatable about an axis aligned with the pressing direction to be engaged with the attachment. The attachment has a loose-fitting hole to loosely receive the movable magnet with the operable portion being engaged with the attachment. 
     An operating unit according to an aspect of the present invention includes a transparent support and a display together serving as a touchscreen, and a pushbutton switch. The pushbutton switch includes an attachment fixed to a surface of the transparent support opposite to the display, an operable portion removably engaged with the attachment, and a detector attached to a surface of the transparent support adjacent to the display. The detector faces the operable portion. The operable portion includes a press portion and a movable magnet movable in a pressing direction from the operable portion toward the detector and in a direction opposite to the pressing direction. The operable portion is rotatable about an axis aligned with the pressing direction to be engaged with the attachment. The attachment has a loose-fitting hole to loosely receive the movable magnet with the operable portion being engaged with the attachment. 
     An amusement machine according to an aspect of the present invention includes a first display that displays an image for amusement, a transparent support and a second display together serving as a touchscreen, and a pushbutton switch. The pushbutton switch includes an attachment fixed to a surface of the transparent support opposite to the second display, an operable portion removably engaged with the attachment, and a detector attached to a surface of the transparent support adjacent to the second display. The detector faces the operable portion. The operable portion includes a press portion and a movable magnet movable in a pressing direction from the operable portion toward the detector and in a direction opposite to the pressing direction. The operable portion is rotatable about an axis aligned with the pressing direction to be engaged with the attachment. The attachment has a loose-fitting hole to loosely receive the movable magnet with the operable portion being engaged with the attachment. 
     Advantageous Effects 
     The technique according to the above aspects of the present invention prevents the operable portion from being removed from the pushbutton switch by a person other than the manager. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is an external perspective view of an amusement machine according to a first embodiment. 
         FIG.  2    is a plan view a button deck that is an operating unit of the amusement machine shown in  FIG.  1   . 
         FIG.  3    is a cross-sectional view taken along line A-A as viewed in the direction indicated by arrows in  FIG.  2   . 
         FIG.  4    is an exploded perspective view of the button deck shown in  FIG.  2   . 
         FIG.  5    is a bottom view of the button deck shown in  FIG.  2   . 
         FIG.  6    is a view showing example display on the button deck shown in  FIG.  2   . 
         FIG.  7    is an exploded perspective view of an operable portion of the pushbutton switch in the button deck shown in  FIG.  2   . 
         FIG.  8    is a perspective view of a base supporting multiple components in the operable portion shown in  FIG.  7   . 
         FIG.  9    is an exploded perspective view of a detector in the pushbutton switch in the button deck shown in  FIG.  2   . 
         FIG.  10    is a block diagram of the amusement machine shown in  FIG.  1   , showing a control system. 
         FIG.  11    includes views each showing a structure for detecting the pressed state of a button in the pushbutton switch in the button deck shown in  FIG.  2   . 
         FIG.  12    is a plan view of a first attachment in the button deck shown in  FIG.  4   . 
         FIG.  13    is a cross-sectional view showing tabs on a first attachment in the button deck shown in  FIG.  4   . 
         FIG.  14    includes cross-sectional views each showing an engagement portion of the base for engagement with the corresponding tab shown in  FIG.  13   . 
         FIG.  15    includes views each showing a lock assembly for the operable portion shown in  FIG.  7   . 
         FIG.  16    is a perspective view of the button deck shown in  FIG.  2    and a fixture. 
         FIG.  17    is a perspective view of the button deck shown in  FIG.  2    and the fixture attached to the pushbutton switch. 
         FIG.  18    is a view showing a lock assembly for the operable portion shown in  FIG.  7    and the fixture unlocking the operable portion. 
         FIG.  19    is a perspective view of a button deck in a second embodiment and a fixture attached to a pushbutton switch. 
         FIG.  20    is a diagram of magnets in the operable portion of the pushbutton switch in the button deck shown in  FIG.  19    and magnets in the fixture, showing their arrangements. 
     
    
    
     DETAILED DESCRIPTION 
     First Embodiment 
     One or more embodiments of the present invention (hereafter also referred to as the present embodiment) will now be described with reference to the drawings. In the present embodiment, a pushbutton switch and an operating unit according to an aspect of the present invention are included in an amusement machine. 
     The present invention is not limited to the embodiments described below, and may be variously designed without departing from the spirit and scope of the invention. The pushbutton switch and the operating unit according to an aspect of the present invention can also be used for industrial equipment and consumer equipment, as well as for various amusement machines. 1. Example Use 
     As shown in  FIG.  1   , a pushbutton switch  15  and a button deck  10 , which is an operating unit including the pushbutton switch  15 , may be included in an amusement machine  1 . As shown in  FIGS.  3  and  4   , the button deck  10  includes the pushbutton switch  15  and a display input unit  11 . The display input unit  11  includes a transparent support plate  13  and a display  12  and serves as a touchscreen. 
     The pushbutton switch  15  includes, as separate portions, an operable portion  20  and a detector  30 . The operable portion  20  includes a button (a press portion)  21 . The detector  30  detects the pressed state of the button  21 . The operable portion  20  is attached to one surface of the transparent support plate  13 . The detector  30  is attached to the other surface of the transparent support plate  13 . The operable portion  20  and the detector  30  face each other with the transparent support plate  13  in between. The detector  30  includes sensors for detecting the pressed state of the button  21  through the transparent support plate  13  (with the transparent support plate  13  in between). 
     As shown in  FIG.  4   , the operable portion  20  is attached to a first attachment  41  fixed to a first surface  13   a  of the transparent support plate  13 . The operable portion  20  is removably engaged with the first attachment  41 . As shown in  FIG.  7   , the operable portion  20  includes a locking magnet  27 . The locking magnet  27  is a movable magnet movable in the pressing direction of the button  21  and in the direction opposite to the pressing direction. 
     As shown in  FIGS.  12  and  15   , the first attachment  41  has a loose-fitting hole  41   h  for loosely receiving the locking magnet  27  with the operable portion  20  being engaged with the first attachment  41 . When the operable portion  20  is engaged with the first attachment  41 , the locking magnet  27  is loosely fitted in the loose-fitting hole  41   h  to lock the engaged operable portion  20 . This prevents the operable portion from being removed by a person other than the manager of the amusement machine  1 , such as a player. 
     2. Example Structure 
     1. Amusement Machine 
     The schematic structure of the amusement machine according to the present embodiment will now be described with reference to  FIG.  1   .  FIG.  1    is an external perspective view of the amusement machine  1  according to the present embodiment. 
     As shown in  FIG.  1   , the amusement machine  1  includes a main display unit (a first display)  2 , a button deck (an operating unit)  10 , and a housing  3  supporting these components. 
     The main display unit  2  displays images for a game played on the amusement machine  1  and includes, for example, a liquid crystal display (LCD). The main display unit  2  has its display surface facing the front of the amusement machine  1 . 
     The button deck  10  receives the player&#39;s operations in a game on the amusement machine  1 . In the present example, the button deck  10  is located below the main display unit  2  at the front of the amusement machine  1 . The button deck  10  is rectangular and elongated laterally. The button deck  10  includes the display input unit  11  as a touchscreen, and the pushbutton switch  15 . 
     For the amusement machine  1  providing slot machine gaming involving spinning reels, for example, the main display unit  2  displays multiple reels with multiple types of symbols. The button deck  10  receives the player&#39;s instruction for spinning the multiple reels, and receives the number of paylines and the number of bets selected by the player. 
     The multiple reels start spinning in response to the player&#39;s instruction for spinning received by the button deck  10 . The reels automatically stop spinning under the control of a main controller  60  (refer to  FIG.  10   , described later). The pattern is determined by the combination of symbols on paylines and by the symbols appearing when the multiple reels are stopped. The player is rewarded based on the determined pattern and the number of bets. 
     2. Button Deck 
       FIG.  2    is a plan view of the button deck  10 .  FIG.  3    is a cross-sectional view taken along line A-A as viewed in the direction indicated by arrows in  FIG.  2   .  FIG.  4    is an exploded perspective view of the button deck  10 .  FIG.  5    is a bottom view of the button deck  10 . 
     As shown in  FIG.  2   , the display input unit  11  is rectangular and elongated laterally. The display input unit  11  includes the pushbutton switch  15  on its display surface. In the present example, the pushbutton switch  15  is circular and at the right end as viewed in plan (refer to  FIG.  1   ). 
     As shown in  FIG.  3   , the display input unit  11  includes a display (a second display)  12  and a transparent support plate (a support)  13  located on the display surface of the display  12 . In the present example, the transparent support plate  13  is a position input device. The transparent support plate  13  and the display  12  together serve as a touchscreen. The display  12  displays images of keys for receiving inputs to the amusement machine  1 , images for a game, or other images. 
     The pushbutton switch  15  includes the operable portion  20  and the detector  30 . The operable portion  20  is attached to one surface, specifically a first surface  13   a , of the transparent support plate  13 . The first surface  13   a  is opposite to the surface facing the display  12 . The operable portion  20  includes the button (a press portion)  21  to receive a pressing operation. The button  21  is transparent. 
     The detector  30  is attached to the other surface, specifically a second surface  13   b , of the transparent support plate  13  and faces the operable portion  20 . The second surface  13   b  is adjacent to the display  12 . The detector  30  includes sensors for detecting the pressed state of the button  21  through the transparent support plate  13 . 
     In the present example, the sensors are reflective sensors  34  (refer to  FIG.  9   ). However, the sensors may be any sensors other than the reflective sensors  34 , such as range sensors, that can detect the pressed state of the button  21  through the transparent support plate  13 . Electronic components for detecting a pressing operation may be located in the operable portion  20 . Such a structure allows a wider choice of sensors. 
     In the present example, the detector  30  is formed from a transparent material in its area facing the button  21  to allow the display surface of the display  12  to be viewed through the transparent button  21 . The detector  30  may have an opening in its area facing the button  21 . 
     In the present example, the pushbutton switch  15  is located above the display  12 . The support is the transparent support plate  13  that is entirely transparent except for its outer edge portion. However, the pushbutton switch  15  may not be located above the display  12 . In this case, the support may be transparent simply in its area receiving the operable portion  20  and the detector  30 , or more specifically in its area through which the sensors in the detector  30  detect the pressed state of the button  21 . 
     In the present example, as shown in  FIG.  4   , the pushbutton switch  15  includes the first attachment  41  (an attachment), a second attachment  43 , and a locking member  45 . The operable portion  20  is attached to the first surface  13   a  of the transparent support plate  13  with the first attachment  41  in between. The operable portion  20  is removably engaged with the first attachment  41 . 
     The first attachment  41  has an annular shape corresponding to the shape of a bezel  22  (refer to  FIG.  7   , described later) in the operable portion  20 . The first attachment  41  is fixed to the first surface  13   a  using a double-sided tape piece  42  in the present example. Attaching the operable portion  20  to the first attachment  41  is described later. 
     The detector  30  is attached to the second surface  13   b  of the transparent support plate  13  with the second attachment  43  in between. The detector  30  is removably engaged with the second attachment  43 . In the present example, the second attachment  43  together with the locking member  45  allows attachment of the detector  30  to the transparent support plate  13 . Each of the second attachment  43  and the locking member  45  has an annular shape and is fitted on the outer periphery of the detector  30 . The second attachment  43  receives the detector  30  on its inner periphery, and the locking member  45  is fitted on the outer periphery of the detector  30 . 
     The locking member  45  is rotated relative to the second attachment  43  and engaged with the second attachment  43 . This attaches the detector  30  to the second surface  13   b . The second attachment  43  is fixed to the second surface  13   b  using a double-sided tape piece  44  in the present example. Further, as shown in  FIGS.  3  and  5   , the display  12  in the display input unit  11  has its back surface connected to a relay board (a controller)  47  (described later). The relay board  47  is connected to the detector  30  through a flexible printed circuit (FPC)  37 . 
       FIG.  6    is a view showing example display on the button deck  10 . The example display in  FIG.  6    shows an operation screen for a slot machine game played on the amusement machine  1 . The pushbutton switch  15  serves as a SPIN button that receives the instruction for spinning the multiple reels. The display  12  displays the letters SPIN indicating the SPIN button at the position corresponding to the button  21 . The letters SPIN are viewable through the transparent button  21 . The display input unit  11  displays LINE buttons  17  for selecting the number of paylines and BET buttons  18  for selecting the number of bets. 
     3. Pushbutton Switch Structure 
     3-1. Operable Portion 
     The operable portion  20  will now be described with reference to  FIGS.  3 ,  7   , and  8 .  FIG.  7    is an exploded perspective view of the operable portion  20  of the pushbutton switch  15  in the button deck  10 .  FIG.  8    is a perspective view of a base  23  supporting multiple components in the operable portion  20 . 
     As shown in  FIG.  7   , the operable portion  20  includes the button  21 , the bezel  22 , the base  23 , multiple springs  24 , multiple tactile-sensation rubber pieces  25 , the locking magnet  27 , and multiple reflective flappers  26 . The button  21  is supported between the bezel  22  and the base  23  and can receive a pressing operation. In the pushbutton switch  15 , the operable portion  20  is located substantially horizontally, and the button  21  has the pressing direction being downward and the returning direction being upward. 
     The button  21  is formed from a transparent material and is circular in the present example (refer to  FIG.  2   ). The button  21  includes a flange  21   a  on its outer periphery. The button  21  can be pressed with the flange  21   a  being held between the base  23  and the bezel  22  attached to the base  23 . The bezel  22  has an opening  22   a  through which an upper surface  21   b  of the button  21  is exposed. 
     The base  23  supports, for example, the button  21 , the bezel  22 , the multiple springs  24 , the multiple tactile-sensation rubber pieces  25 , the locking magnet  27 , and the multiple reflective flappers  26 . The base  23  is fastened to the transparent support plate  13  with the first attachment  41  in between. The base  23  is rotatable about an axis aligned with the pressing direction from the operable portion  20  toward the detector  30  for engagement with the first attachment  41 . The base  23  being engaged with the first attachment  41  can tightly fasten the operable portion  20  to the first attachment  41 . 
     As shown in  FIG.  8   , the base  23  includes an annular component compartment  23   a  in an outer peripheral portion. The component compartment  23   a  accommodates the multiple springs  24 , the multiple tactile-sensation rubber pieces  25 , the locking magnet  27 , and the multiple reflective flappers  26 . The multiple springs  24  return the pressed button  21  to the position before pressing. The multiple tactile-sensation rubber pieces  25  provide a tactile sensation to the player pressing the button  21 . In the present example, three springs  24  and three tactile-sensation rubber pieces  25  are included. 
     The multiple springs  24  and the multiple tactile-sensation rubber pieces  25  are in contact with the flange  21   a  on the outer periphery of the button  21  (refer to  FIG.  3   ). The multiple springs  24  in contact with the flange  21   a  can return the pressed button  21  to its original position. The multiple tactile-sensation rubber pieces  25  in contact with the flange  21   a  can provide a tactile sensation to the player pressing the button  21 . 
     The reflective flappers  26  are used when the detector  30  detects the pressed state of the button  21 . In the present example, three (multiple) reflective flappers  26  are included. The reflective flappers  26  are supported pivotally on support portions  23   b  of the component compartment  23   a . Each reflective flapper  26  includes a shaft  26   a  extending in the circumferential direction of the component compartment  23   a.    
     Each reflective flapper  26  includes a press piece  26   b  located inward from the shaft  26   a  and a reflective portion  26   c  located outward from the shaft  26   a . The press piece  26   b  comes in contact with and is pressed by a lower end  21   d  (refer to views  1000  and  1001  in  FIG.  11   ) of an outer peripheral portion of the button  21 . The reflective portion  26   c  has its lower surface being a reflective surface. The reflective flapper  26  changes its orientation in accordance with the pressed or unpressed state of the button  21  and thus changes the orientation of the reflective surface (refer to the views  1000  and  1001  in  FIG.  11   ). 
     The component compartment  23   a  has openings at the bottom to allow passage of light from the reflective sensors  34  in the detector  30  and allow passage of light reflected by the reflective flappers  26  toward the reflective sensors  34 . The first attachment  41  also has such openings, specifically openings  41   t  (refer to  FIG.  12   ). 
     The locking magnet  27  is rod-like and has the direction of magnetization parallel to the pressing direction of the button  21 . The locking magnet  27  is a movable magnet movable in the pressing direction of the button  21  and in the direction opposite to the pressing direction. The locking magnet  27  is loosely fitted in the loose-fitting hole  41   h  (refer to  FIG.  15   ) in the first attachment  41  to lock the operable portion  20  and prevent removal from the first attachment  41 . 
     The locking magnet  27  is fitted loosely in a hole  23   c  in the bottom of the component compartment  23   a . The locking magnet  27  includes a head with a larger diameter than the other portion. The locking magnet  27  is prevented from falling out of the hole  23   c  with its head stuck in the hole  23   c.    
     The component compartment  23   a  includes an inner peripheral wall  23   d  defining the component compartment  23   a . The wall  23   d  guides the button  21  to move vertically when the button  21  is pressed or returns. As shown in  FIG.  3   , the button  21  has a groove  21   c  on its lower surface to receive the upper end of the wall  23   d.    
     To prepare the operable portion  20 , the button  21  and the bezel  22  are fitted from above in this order onto the component compartment  23   a  accommodating the above various components. The base  23  and the bezel  22  are then fastened together with multiple screws  28 . 
     3-2. Detector 
     The detector  30  will now be described with reference to  FIGS.  3  and  9   .  FIG.  9    is an exploded perspective view of the detector  30  in the pushbutton switch  15  in the button deck  10 . As shown in  FIG.  9   , the detector  30  includes a case  31 , a mounting board  32 , a lower cover  33 , the multiple reflective sensors  34 , and the FPC  37 . 
     The multiple reflective sensors  34  are mounted on the mounting board  32 . In the present example, three reflective sensors  34  are included to correspond to the three reflective flappers  26  in the operable portion  20 . Each reflective sensor  34  faces the corresponding reflective flapper  26  with the operable portion  20  and the detector  30  being attached to the transparent support plate  13 . 
     The reflective sensor  34  is an optical sensor including a light emitter  34   a  and a light receiver  34   b . The light emitter  34   a  emits light toward the reflective flapper  26  through the transparent support plate  13 . The reflective flapper  26  reflects the light that is then received by the light receiver  34   b . The light receiver  34   b  receives light with intensity changeable in accordance with the orientation of the reflective flapper  26 . The change in light intensity thus allows detection of the pressed state of the button  21 . 
     As shown in  FIG.  9   , the mounting board  32  incorporates multiple light-emitting diodes (LEDs) (light emitters or electronic components)  38  as well as the multiple reflective sensors  34 . The detector  30  can thus emit light when the multiple LEDs  38  is on. The FPC  37  has one end connected to the mounting board  32  and the other end connected to the relay board  47  (refer to  FIG.  3   ) attached to the back surface of the display  12 . The FPC  37  electrically connects the mounting board  32  and the relay board  47 . 
     The case  31  supports, for example, the mounting board  32  and the multiple reflective sensors  34 . The lower cover  33  is fitted to the case  31  and covers the bottom of the detector  30 . To prepare the detector  30 , the lower cover  33  is fitted onto the bottom of the case  31  accommodating, for example, the mounting board  32  and the multiple reflective sensors  34 . The case  31  and the lower cover  33  are then fastened together with multiple screws  39 . 
     4. Control System in Amusement Machine 
       FIG.  10    is a block diagram of the amusement machine  1 , showing a control system. As shown in  FIG.  10   , the amusement machine  1  includes the main controller  60  and the relay board  47  as a controller. The main controller  60  is connected to the main display unit  2  and causes the main display unit  2  to display images for a game to perform the game. 
     The main controller  60  is also connected to the relay board  47  and receives, using the relay board  47 , an instruction input on the button deck  10 . The main controller  60  also controls the button deck  10  using the relay board  47 . The relay board  47  controls the operation of the button deck  10 , and is connected to the detector  30  through the FPC  37  and also connected to the display input unit  11  as a touch screen. 
     As described above, the button deck  10  in the present example includes the pushbutton switch  15  including, as separate portions, the operable portion  20  and the detector  30 . The electronic components are located in the detector  30  alone attached to the second surface  13   b  of the transparent support plate  13  adjacent to the inside of the machine. The relay board  47  is thus unconnected to the operable portion  20 . 
     5. Detecting Pressing Operation with Pushbutton Switch 
       FIG.  11    includes views each showing a structure for detecting the pressed state of the button  21  in the pushbutton switch  15  in the pushbutton switch  15 . FIG.  11  includes a cross-sectional view  1000  of the main part of the pushbutton switch  15  with the button  21  being unpressed, and includes a cross-sectional view  1001  of the main part of the pushbutton switch  15  with the button  21  being pressed.  FIG.  11    also includes a cross-sectional view  1002  of the main part of the pushbutton switch  15  being unpressed. The view  1002  is taken along a line different from the line for the view  1001 . 
     As shown in the views  1000  and  1002  in  FIG.  11   , when the button  21  is unpressed, each reflective flapper  26  in the operable portion  20  is in a first orientation to reflect light from the corresponding reflective sensor  34  in the detector  30  in the direction back toward the reflective sensor  34 . In the first orientation, the reflective surface reflects light from the light emitter  34   a  in the direction for entry into the light receiver  34   b.    
     The light receiver  34   b  receives, through the transparent support plate  13 , light L emitted from the light emitter  34   a  and reflected by the reflective flapper  26  in the first orientation. The light receiver  34   b  outputs an electrical signal corresponding to the intensity of the received reflected light, and allows detection of the button  21  being unpressed based on the electrical signal. 
     As shown in the view  1001  in  FIG.  11   , when the button  21  is pressed, each reflective flapper  26  in the operable portion  20  is in a second orientation to reflect light from the corresponding reflective sensor  34  in the detector  30  in a direction different from the direction toward the reflective sensor  34 . In the second orientation, the reflective surface reflects light from the light emitter  34   a  in a direction different from the direction for entry into the light receiver  34   b.    
     The light receiver  34   b  does not receive light L emitted from the light emitter  34   a  and reflected by the reflective flapper  26  in the second orientation, and thus receives light with reduced intensity. The light receiver  34   b  outputs a lower electrical signal in accordance with the reduced intensity of received light. This change in the electrical signal allows detection of the button  21  being pressed. 
     6. Tabs  41   a  on First Attachment  41   
       FIG.  12    is a plan view of the first attachment in the button deck shown in FIG.  4 .  FIG.  13    is a cross-sectional view showing tabs  41   a  on the first attachment  41  in the button deck  10  shown in  FIG.  4   .  FIG.  14    includes cross-sectional views each showing an engagement portion  20   a  of the base  23  for engagement with the corresponding tab  41   a  shown in  FIG.  13   . 
     As shown in  FIGS.  12  and  13   , the first attachment  41  includes the multiple tabs  41   a  protruding upward. Each tab  41   a  is an L-shaped hook. As shown in  FIG.  14   , the base  23  includes the engagement portion  20   a  engageable with the tab  41   a . The engagement portion  20   a  is circumferentially adjacent to an arc-shaped hole in the bottom surface of the base  23  extending along the outer edge of the base  23 . 
     The engagement portion  20   a  of the base  23  in the operable portion  20  is engaged with the tab  41   a  on the first attachment  41  to engage the operable portion  20  with the first attachment  41 . The base  23  in the operable portion  20  includes multiple engagement portions  20   a  corresponding to the multiple tabs  41   a.    
     In the state shown in a view  1101  in  FIG.  14   , the tab  41   a  is spaced from the engagement portion  20   a . When the base  23  is rotated to engage with the first attachment  41 , the engagement portion  20   a  engages with the tab  41   a  as shown in a view  1102  in  FIG.  14   . The engagement portion  20   a  being engaged with the tab  41   a  can securely engage the operable portion  20  with the first attachment  41 . 
     7. Lock Assembly for Operable Portion  20   
       FIG.  15    includes views each showing a lock assembly for the operable portion  20  shown in  FIG.  7   . As shown in  FIGS.  12  and  15   , the first attachment  41  has the loose-fitting hole  41   h  for loosely receiving the locking magnet  27  with the operable portion  20  being engaged with the first attachment  41 . 
       FIG.  15    includes a view  1201  showing the operable portion  20  not at the position for engagement with the first attachment  41 , or more specifically showing the engagement portion  20   a  of the base  23  out of engagement with the tab  41   a  on the first attachment  41 . In this case, the locking magnet  27  is in contact with the upper surface of the first attachment  41 , and the operable portion  20  is rotatable about an axis aligned with the pressing direction. 
       FIG.  15    includes a view  1202  showing the operable portion  20  rotated from the position shown in the view  1201  and engaged with the first attachment  41 . More specifically, the view  1202  shows the engagement portion  20   a  of the base  23  at the position for engagement with the tab  41   a  on the first attachment  41 . 
     In the state shown in the view  1202 , the locking magnet  27  in the operable portion  20  is aligned with the loose-fitting hole  41   h  in the first attachment  41  and falls into the loose-fitting hole  41   h  under its weight. This locks the operable portion  20  in the engaged state and is unrotatable about an axis aligned with the pressing direction. The operable portion  20  is thus unremovable from the first attachment  41  fixed to the transparent support plate  13 . 
     Unlocking the operable portion  20  in the engaged state will now be described. With the operable portion  20  being engaged with the first attachment  41 , the locking magnet  27  is movable in the pressing direction and in the direction opposite to the pressing direction. 
       FIG.  16    is a view of the button deck  10  (the transparent support plate  13  and the operable portion  20 ) shown in  FIG.  2    and a fixture  50  for unlocking the operable portion  20  in the engaged state.  FIG.  17    is a view of the fixture  50  attached to the operable portion  20 .  FIG.  18    is a cross-sectional view of the fixture  50  attached to the operable portion  20 . 
     As shown in  FIGS.  16  and  17   , the fixture  50  is annular and can cover the component compartment  23   a  in the base  23  in the operable portion  20  from above. The fixture  50  is not limited to being annular but may be, for example, circular. The fixture  50  includes an unlocking magnet  51  (a removal magnet) at a position corresponding to a position above the locking magnet  27  when the fixture  50  is attached to the operable portion  20 . 
     In this state, the unlocking magnet  51  has the direction of magnetization parallel to the pressing direction of the button  21  and has a polarity to attract the locking magnet  27 . When the fixture  50  is attached to the operable portion  20  engaged with the first attachment  41  as shown in  FIG.  18   , the locking magnet  27  is attracted by the unlocking magnet  51  and removed from the loose-fitting hole  41   h . This unlocks the operable portion  20  and allows rotation of the operable portion  20  for removal from the first attachment  41  fixed to the transparent support plate  13 . 
     8. Effects 
     As described above, the operable portion  20  with the above structure is difficult to remove from the transparent support plate  13  without the dedicated fixture  50  for unlocking the operable portion  20  in the engaged state. This prevents the operable portion  20  from being removed from the pushbutton switch  15  by a person other than the manager of the amusement machine  1 . 
     The pushbutton switch  15  includes, as fully separate portions, the operable portion  20  and the detector  30  that are located on different surfaces, specifically the front and back surfaces, of the transparent support plate  13 . The transparent support plate  13  thus eliminates an opening for receiving the pushbutton switch and avoids fracture due to a decrease in strength. 
     The above structure eliminates work for producing an opening in the transparent support plate  13  and facilitates attachment of the pushbutton switch  15 . The above structure also reduces restrictions on the attachment position of the pushbutton switch  15 , increasing flexibility in attachment. 
     A known pushbutton switch, which includes an operable portion  20  and a detector  30  integral with each other, is to have a different thickness for a transparent support plate  13  with a different thickness (or with a different depth of the attachment opening). In contrast, the pushbutton switch with the above structure is attachable to the transparent support plate  13  with a different thickness that allows the detector  30  to detect the pressed state of the button  21 . 
     In the above structure, the electronic components for detecting the pressed state of the button  21  can be included without being located in the operable portion  20 . More specifically, the multiple LEDs  38  for lighting the pushbutton switch  15  are located in the detector  30 . The operable portion  20  uses no electricity and eliminates, for example, wiring, thus facilitating maintenance. The transparent support plate  13  also eliminates openings for wiring. 
     In the above structure, the button  21  includes a transparent portion. The detector  30  has an opening or is formed from a transparent material in its area corresponding to the button  21 . This allows the screen of the display  12  to be viewed through the button  21 . The first attachment  41  and the second attachment  43  facilitate attachment of the operable portion  20  and the detector  30  to the transparent support plate  13 . 
     Second Embodiment 
     Another embodiment of the present invention will now be described. For ease of explanation, the components having the same functions as the components described in the above embodiment are given the same reference numerals as those components and will not be described. 
     In a pushbutton switch  15  according to a second embodiment, an operable portion  20  includes multiple locking magnets  27 , and a first attachment  41  has multiple loose-fitting holes  41   h  for the respective locking magnets  27 . The other features in the second embodiment are the same as or similar to those in the first embodiment. In the second embodiment, a fixture  50  also includes multiple unlocking magnets  51  for the respective multiple locking magnets  27 . 
       FIG.  19    is a view of a button deck  10  (a transparent support plate  13  and the operable portion  20 ) in the second embodiment and the fixture  50  for unlocking the operable portion  20  in the engaged state.  FIG.  19    shows the fixture  50  attached to the operable portion  20 . As illustrated, the fixture  50  includes, for example, four unlocking magnets  51 . The operable portion  20  also includes four locking magnets  27  corresponding to the four unlocking magnets  51 . 
     In the second embodiment, when the operable portion  20  is engaged with the first attachment  41 , the locking magnets  27  are fitted in the respective loose-fitting holes  41   h  to lock the engaged operable portion  20 . When the fixture  50  is attached to the operable portion  20  engaged with the first attachment  41 , the locking magnets  27  are attracted by the respective unlocking magnets  51  and removed from the loose-fitting holes  41   h.    
     This unlocks the operable portion  20  and allows rotation of the operable portion  20  for removal from the first attachment  41  fixed to the transparent support plate  13 . An operable portion  20  including a single locking magnet  27  may be unlocked and removed with a common magnet without the fixture. In contrast, the operable portion  20  including the multiple locking magnets  27  at appropriate positions is more difficult to unlock without the dedicated fixture. 
       FIG.  20    is a schematic diagram of the locking magnets  27  in the operable portion  20  and the unlocking magnets  51  in the operable portion  20 , showing their polarity arrangements. The numbers in the figure indicate positions in the operable portion  20  and in the operable portion  20 . 
     In the example of  FIG.  20   , in the operable portion  20 , the poles of the locking magnets  27  adjacent to the fixture  50  are the N pole, the N pole, the S pole, and the S pole in numerical order. In the fixture  50 , the poles of the unlocking magnets  51  adjacent to the operable portion  20  are the S pole, the S pole, the N pole, and the N pole in numerical order to correspond to the poles in the operable portion  20 . Thus, the locking magnets  27  in the operable portion  20  are arranged to attract the corresponding unlocking magnets  51  in the fixture  50 . 
     However, the polarity arrangement of the multiple locking magnets  27  is not limited to the example of  FIG.  20   . The polarity arrangement may be any one of the arrangements below, where a first pole is the S pole or the N pole, and a second pole is the pole opposite to the first pole. The arrangement may be, in numerical order, the first pole, the first pole, the first pole, and the first pole; the first pole, the first pole, the first pole, and the second pole; the first pole, the first pole, the second pole, and the second pole; and the first pole, the second pole, the first pole, and the second pole. Similarly to the above example, the unlocking magnets  51  in the fixture  50  are orientated to have polarities to magnetically attract the corresponding locking magnets  27  for the corresponding numbers. 
     Among the above arrangements, the second, third, or fourth arrangement combines different polarities and may allow more difficult unlocking with a single magnet. In other words, at least one of the multiple movable magnets may be oriented to have a polarity different from the polarity of at least another one of the multiple movable magnets. 
     Overview 
     A pushbutton switch according to an aspect of the present invention includes an attachment fixed to one surface of a support being a plate, an operable portion removably engaged with the attachment, and a detector attached to another surface of the support and facing the operable portion. The operable portion includes a press portion and a movable magnet movable in a pressing direction from the operable portion toward the detector and in a direction opposite to the pressing direction. The operable portion is rotatable about an axis aligned with the pressing direction to be engaged with the attachment. The attachment has a loose-fitting hole to loosely receive the movable magnet with the operable portion being engaged with the attachment. 
     The above structure prevents the operable portion from being removed from the pushbutton switch by a person other than the manager. The operable portion in the engaged state is locked using the movable magnet and can be unlocked by the manager. 
     In the pushbutton switch according to the above aspect, the attachment may include a tab. The operable portion may include an engagement portion. The operable portion may be engaged with the attachment through engagement of the engagement portion with the tab. The above structure can securely engage the operable portion with the attachment through engagement of the engagement portion with the tab. 
     In the pushbutton switch according to the above aspect, the operable portion may further include a base supporting the press portion. The base may include the engagement portion. The above structure can tightly fasten the operable portion to the attachment through engagement of the base supporting the press portion with the attachment. 
     A pushbutton switch unit according to an aspect of the present invention includes the pushbutton switch according to the above aspect, and a fixture detachably attachable to the operable portion. The fixture includes a removal magnet that magnetically removes the movable magnet from the loose-fitting hole when the fixture is attached to the operable portion engaged with the attachment. 
     The above structure prevents the operable portion from being removed from the pushbutton switch by a person other than the manager. The operable portion can be unlocked by the manager using the fixture. 
     In the pushbutton switch according to the above aspect, the operable portion may include a plurality of the movable magnets. The attachment may have a plurality of the loose-fitting holes for the respective plurality of movable magnets. Further, at least one of the plurality of movable magnets may be oriented to have a polarity different from a polarity of at least another one of the plurality of movable magnets. The above structure more effectively prevents the operable portion from being removed from the pushbutton switch by a person other than the manager. The operable portion can be unlocked by the manager using the fixture. 
     A pushbutton switch unit according to an aspect of the present invention includes the pushbutton switch according to the above aspect, and a fixture detachably attachable to the operable portion. The fixture includes a plurality of removal magnets for the respective plurality of movable magnets. The plurality of removal magnets magnetically remove the respective plurality of movable magnets from the respective plurality of loose-fitting holes when the fixture is attached to the operable portion engaged with the attachment. The above structure more effectively prevents the operable portion from being removed from the pushbutton switch by a person other than the manager. 
     An operating unit according to an aspect of the present invention includes a transparent support and a display together serving as a touchscreen, and a pushbutton switch. The pushbutton switch includes an attachment fixed to a surface of the transparent support opposite to the display, an operable portion removably engaged with the attachment, and a detector attached to a surface of the transparent support adjacent to the display. The detector faces the operable portion. The operable portion includes a press portion and a movable magnet movable in a pressing direction from the operable portion toward the detector and in a direction opposite to the pressing direction. The operable portion is rotatable about an axis aligned with the pressing direction to be engaged with the attachment. The attachment has a loose-fitting hole to loosely receive the movable magnet with the operable portion being engaged with the attachment. 
     The above structure prevents the operable portion from being removed from the pushbutton switch by a person other than the manager. The operable portion in the engaged state is locked using the movable magnet and can be unlocked by the manager. 
     An amusement machine according to an aspect of the present invention includes a first display that displays an image for amusement, a transparent support and a second display together serving as a touchscreen, and a pushbutton switch. The pushbutton switch includes an attachment fixed to a surface of the transparent support opposite to the second display, an operable portion removably engaged with the attachment, and a detector attached to a surface of the transparent support adjacent to the second display. The detector faces the operable portion. The operable portion includes a press portion and a movable magnet movable in a pressing direction from the operable portion toward the detector and in a direction opposite to the pressing direction. The operable portion is rotatable about an axis aligned with the pressing direction to be engaged with the attachment. The attachment has a loose-fitting hole to loosely receive the movable magnet with the operable portion being engaged with the attachment. 
     The above structure prevents the operable portion from being removed from the pushbutton switch by a person other than the manager. The operable portion in the engaged state is locked using the movable magnet and can be unlocked by the manager. 
     The present invention is not limited to the above embodiments, but may be modified variously within the spirit and scope of the claimed invention. The technical means described in different embodiments may be combined as appropriate in other embodiments within the technical scope of the invention. The technical means described in different embodiments may be combined to produce a new technical feature.