Abstract:
Provided is a rotation detection device that detects a rotational direction and amount of a rotatable operation member. The detection device manages to reduce the rotation detection pitch while maintaining sufficient clearance for a rotation detection switch to operate. In other words, sufficient distance is given between rotation detection members such that the switch can accurately detect the movement from one member to the next. The rotatable operation member generally includes a plurality of switch driving sections that rotate in unison. A rotation detection switch generally includes a portion that moves in a first and second direction opposite to each other when coming into contact with the rotatable operation members, and is configured to output a detection signal at each movement. The switch and rotatable operation members are configured so that the movement direction of the detector is in a direction orthogonal to the circumferential direction of rotation.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is the national stage application of PCT/JP2010/006650, international filing date Nov. 12, 2010, and claims priority to JP 2010-004501, filed in Japan on Jan. 13, 2010, the entire disclosure of which are hereby incorporated by reference in its entirety. 
     BACKGROUND 
     The present disclosure relates to a rotation detection device that is disposed on a panel in an automobile interior or the like. 
     Typically, a rotation detection device disposed in an automobile interior or the like includes a rotatable operation member that can be moved, for example rotated while being held with fingers, and a detection device that outputs a detection signal corresponding to the direction and the amount of that relative movement. Although a rotary encoder can be used as the detection device, such a rotary encoder is generally expensive, and, thus, the possibility of detecting the rotation using other devices such as inexpensive switches is being investigated. 
     Conventionally, a rotation detection device using a switch as shown in  FIG. 14  is known (see, e.g., Japanese Patent No. 4066037). This device includes a rotatable operation member  80  that is rotated and a rotation detection switch  84  that is for detecting the rotation. 
     The rotatable operation member  80  is configured to be rotated while being held with fingers for example and a plurality of driving protrusions  82  that protrude outward in the radial directions from an outer circumferential face of the rotatable knob  81 . The driving protrusions  82  are arranged on the outer circumferential face of the rotatable knob  81  at constant intervals in the circumferential direction of the outer circumferential face, and rotate unitarily with the rotatable knob  81 . 
     The rotation detection switch  84  is provided with a switch body  86  and a detector  88  that is attached to the switch body  86  such that the detector  88  can move upward and downward (swing) to the left and right. The driving protrusions  82  are sequentially brought into contact with the detector  88  as the rotatable knob  81  is being rotated, and, at each contact, an operation is repeated in which the detector  88  moves downward from an origin position (upright position) in a direction corresponding to the rotational direction of the rotatable knob  81  (a circumferential direction of rotation of the rotatable knob  81 ) and then returns to the original origin position. That is to say, the rotation detection switch  84  is disposed in an orientation in which the upward and downward directions of the movement (the directions of swing) of the detector  88  match the circumferential directions of rotation of the rotatable knob  81  and the driving protrusions  82 . The switch body  86  generates a detection signal each time the detector  88  moves downward and returns. 
     Well known switches can be used as the rotation detection switch  84 , and Japanese Patent No. 4066037 describes an example of a switch  84  of a two-direction three-contact type as shown in  FIG. 15 . The switch body  86  of the rotation detection switch  84  shown in  FIG. 15  is provided with a casing  90  that has a bottom wall  90   a , a switch spring  92  that is accommodated in the casing  90 , a central contact point  94 C and left and right contact points  94 A and  94 B that are arranged on the bottom wall  90   a , terminals  95 A,  95 B, and  95 C that respectively correspond to the contact points  94 A,  94 B, and  94 C, a support shaft  96  that is disposed in the upper portion of the casing  90  and forms a swing shaft of the detector  88 , and a pair of left and right cam sections  98 A and  98 B that rotate unitarily with the support shaft  96 . This switch is merely exemplary of the type of switches that can be used. 
     The switch spring  92  can be made of a metal plate capable of being elastically deflected, and both end portions thereof respectively form spring contact points  92   a  and  92   b  that are pressed against the bottom wall  90   a . The shape of the switch spring  92  is generally set so as to achieve the following operability. That is to say, the switch spring  92  is set so as to be in uniform contact with the cam sections  98 A and  98 B from below, so that the detector  88  is held at the origin position as shown in the drawing, and, in this state, the spring contact point  92   a  is positioned between the contact points  95 A and  95 C, and the spring contact point  92   b  is positioned between the contact points  95 B and  95 C. 
     In this device, if the rotatable knob  81  is for example rotated in a direction indicated by the arrow  89 A in  FIGS. 14 and 15 , the driving protrusions  82  that rotate unitarily with the rotatable knob  81  are sequentially brought into contact with the detector  88  of the rotation detection switch  84  and move the detector  88  downward in a direction corresponding to the rotational direction (right direction in  FIG. 15 ) (see the dashed double dotted line  88 A in  FIG. 15 ). Accordingly, the cam section  98 A linked to the support shaft  96  of the detector  88  is lowered, elastically deflecting the switch spring  92  in the direction indicated by the arrow  93 A in  FIG. 15 , and, thus, the two spring contact points  92   a  and  92   b  of the switch spring  92  are caused to slide along the bottom wall  90   a  and are brought into contact with the contact points  94 A and  94 C. In this manner, conduction is established between the terminal  95 A corresponding to the contact point  94 A and the terminal  95 C corresponding to the contact point  94 C via the switch spring  92 , and a detection signal indicating that the rotatable knob  81  has been rotated in the direction indicated by the arrow  89 A is generated. Subsequently, when the driving protrusion  82  moves past the detector  88 , the detector  88  returns to the original origin position due to the elastic return force of the switch spring  92 , and the two spring contact points  92   a  and  92   b  of the switch spring  92  are moved away from the contact points  94 A and  94 C. 
     On the other hand, if the rotatable knob  81  is rotated in a direction indicated by the arrow  89 B in  FIG. 14 , the detector  88  is moved downward in the direction opposite the previous direction, that is, to the left in  FIG. 15 . Accordingly, the cam section  98 B is lowered, elastically deflecting the switch spring  92  in the direction indicated by the arrow  93 B in  FIG. 15 , and, thus, the spring contact points  92   a  and  92   b  are this time brought into contact with the contact points  94 C and  94 B respectively, and conduction is established between the terminals  95 C and  95 B. Accordingly, a detection signal different from the above-described detection signal is generated. 
     That is to say, in this device, if the rotatable operation member  80  is rotated, detection signals that vary depending on the rotational direction are intermittently generated, and the rotational direction and the rotational amount are recognized based on the type and the number of the detection signals generated. 
     In rotation detection devices of this sort, it is an important issue to reduce a rotation detection pitch for the rotatable operation member, that is, an arrangement pitch Pt of the driving protrusions  82  for driving the rotation detection switch  84  in the device shown in  FIG. 15  (interval between the driving protrusions  82  shown in  FIG. 15 ). A reduction in the rotation detection pitch, that is, the arrangement pitch Pt enables greater precision in detecting the rotational amount with the rotation detection switch  84  without increasing the size of the entire rotatable operation member including the driving protrusions  82 . Furthermore, in the case where a click mechanism that generates a click feel in accordance with the rotation detection pitch is provided, it is possible to improve a sense of operation given to the user by reducing the click feel generation pitch. 
     However, in this device, there is a strict limitation as to the ability to reduce the pitch Pt of the driving protrusions  82  corresponding to the rotation detection pitch, which is based on providing sufficient distance so as to allow a proper swing movement of the detector  88 . If the arrangement pitch Pt is too small, then, after one of the driving protrusions  82  is brought into contact with the detector  88  and moves it downward and then releases the detector  88 , the next driving protrusion  82  is brought into contact with the detector  88  before the detector  88  returns to the proper origin position (position indicated by the solid line in  FIG. 15 ). Accordingly, a proper return movement of the detector  88  is inhibited, which causes erroneous detection. In other words, in order to ensure a proper downward movement and return movement of the detector  88 , the interval between the driving protrusions  82  that are adjacent to each other, that is, the arrangement pitch Pt has to be set larger to some extent than the swing stroke of the detector  88  (the maximum movement distance of the detector  88  in directions orthogonal both to the direction of the support shaft  96 , which is a shaft about which the detector  88  swings, and to the radial direction of swing). Accordingly, a strict limitation is imposed on the reduction in the arrangement pitch Pt. 
     SUMMARY 
     In view of these circumstances, it is an object of the present disclosure to provide a rotation detection device, including a rotatable operation member and a rotation detection switch that detects rotation of the rotatable operation member, wherein the rotation detection pitch can be reduced while a proper operation of the rotation detection switch is ensured. 
     The rotation detection device provided by the present disclosure includes a rotatable operation member that is configured to be rotated in both a first rotational direction and a second rotational direction, which is opposite the first rotational direction, about a given operation central axis, and a rotation detection switch that detects a rotational direction and a rotational amount of the rotatable operation member. The rotatable operation member includes a plurality of switch driving sections that are intermittently arranged in a circumferential direction of rotation that corresponds to the rotational direction of the rotatable operation member. The rotation detection switch is provided with a detector and a switch body. The switch body holds the detector such that the detector can move in both a first movement direction and a second movement direction, which are opposite each other, from an origin position at which the detector is in an upright posture, biases the detector toward the origin position, and, each time the detector moves in the first movement direction or the second movement direction by a predetermined amount, outputs a detection signal corresponding to the movement direction. The rotation detection switch is disposed in a posture in which the first movement direction and the second movement direction of the detector are preferably closer to a direction (a radial direction of rotation of the rotatable operation member, or a direction parallel to the operation central axis) orthogonal to the circumferential direction of rotation of the rotatable operation member than to the circumferential direction of rotation at a position where the switch driving sections of the rotatable operation member can be brought into contact with the detector. In other words, the rotation detection switch is preferably configured such that it operates (i.e., swings) in a direction oblique to the relative movement it is attempting to detect. By doing so, at least a portion of the movement of the rotation detection switch is in a direction that is not parallel to the movement direction. Thus, the pitch between the switch driving members can be reduced. Additionally, the switch driving sections of the rotatable operation member are each shaped such that, when brought into contact with the detector as the rotatable operation member is being rotated in the first rotational direction, the switch driving sections move the detector in the first movement direction by at least the predetermined amount and then release the detector, and such that, when brought into contact with the detector as the rotatable operation member is being rotated in the second rotational direction, the switch driving sections move the detector in the second movement direction by at least the predetermined amount and then release the detector. 
     In this rotatable operation device, the rotation detection switch is disposed such that the movement directions of the detector of the rotation detection switch are preferably closer to a direction orthogonal to the circumferential direction of rotation of the rotatable operation member than to the circumferential direction of rotation, and the switch driving sections of the rotatable operation member are arranged so as to move the detector in the movement directions, and, thus, the required movement distance of the detector in the circumferential direction of rotation is short. Accordingly, while a proper movement of the detector is ensured, the arrangement pitch of the switch driving sections, that is, the rotation detection pitch can be reduced, and the precision in detecting the rotation can be improved. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1A  is a side view of a rotation detection device according to a first embodiment of the present disclosure, and  FIG. 1B  is a cross-sectional view taken along the line  1 B- 1 B in  FIG. 1(   a ). 
         FIG. 2  is a perspective view showing a state where a detector of a rotation detection switch is at its origin position in the rotatable operation device. 
         FIG. 3  is a perspective view showing a state where the detector has been moved downward from the origin position. 
         FIG. 4A  is a side view showing a state where the detector of the rotation detection switch is at the origin position, and  FIG. 4B  is a cross-sectional view taken along the line  4 B- 4 B in  FIG. 4A . 
         FIG. 5A  is a side view showing a state where a switch driving section of a rotatable operation member has been brought into contact with the detector of the rotation detection switch and the detector starts to move downward from the origin position in a first downward direction, and  FIG. 5B  is a cross-sectional view taken along the line  5 B- 5 B in  FIG. 5A . 
         FIG. 6A  is a side view showing a state where the detector of the rotation detection switch starts to surmount the switch driving section, and  FIG. 6B  is a cross-sectional view taken along the line  6 B- 6 B in  FIG. 6A . 
         FIG. 7A  is a side view showing a state where the detector of the rotation detection switch is about to completely surmount the switch driving section, and  FIG. 7B  is a cross-sectional view taken along the line  7 B- 7 B in  FIG. 7A . 
         FIG. 8  is a side view of a rotation detection device according to a second embodiment of the present disclosure. 
         FIG. 9  is a cross-sectional view taken along the line  9 - 9  in  FIG. 8 . 
         FIG. 10A  is a side view showing a state where the detector of the rotation detection switch is at its origin position in the rotation detection device shown in  FIG. 8 , and  FIG. 10B  is a cross-sectional view taken along the line  10 B- 10 B in  FIG. 10A . 
         FIG. 11A  is a side view showing a state where a switch driving section of a rotatable operation member has been brought into contact with the detector of the rotation detection switch and the detector starts to move downward from the origin position in a first downward direction in the rotation detection device shown in  FIG. 8 , and  FIG. 11B  is a cross-sectional view taken along the line  11 B- 11 B in  FIG. 11A . 
         FIG. 12A  is a side view showing a state where the detector of the rotation detection switch starts to surmount the switch driving section in the rotation detection device shown in  FIG. 8 , and  FIG. 12B  is a cross-sectional view taken along the line  12 B- 12 B in  FIG. 12A . 
         FIG. 13A  is a side view showing a state where the detector of the rotation detection switch is about to completely surmount the switch driving section in the rotation detection device shown in  FIG. 8 , and  FIG. 13B  is a cross-sectional view taken along the line  13 B- 13 B in  FIG. 13A . 
         FIG. 14  is a perspective view showing an example of a conventional rotatable operation device. 
         FIG. 15  is a cross-sectional view showing an example of the structure of a rotation detection switch. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     A rotation detection device according to a first embodiment of the present disclosure will be described with reference to  FIGS. 1 to 7 . 
     The rotation detection device shown in  FIGS. 1 to 3  is disposed in an automobile interior or the like, and, when it is subjected to a rotational operation, outputs a detection signal corresponding to the direction and the amount of that rotation. This rotation detection device is provided with a rotatable operation member  10  is configured to rotate about an axis, a click mechanism  12  that is configured to generate a click feel in accordance with the rotation ( FIGS. 2 and 3 ), and a rotation detection switch  14  that is configured to detect the rotational direction and the rotational amount of the rotatable operation member  10 . 
     The rotatable operation member  10  is provided with a rotatable knob  16 , a click generating section  18 , and a plurality of switch driving sections  20 . The rotatable operation member  10  is supported by a panel  22  as shown in  FIG. 1  or by a circuit board  24  behind the panel  22  such that the entire rotatable operation member  10  can be rotated. 
     The rotatable knob  16  in substantially in the shape of a cylinder, is disposed so as to protrude from the rear side of the panel  22  (the right side in  FIG. 1 ) to the front side (the left side in  FIG. 1 ), and is configured to be rotated while being held with fingers for example from the front side. Specifically, taking the central axis of the rotatable knob  16  as an operation central axis X ( FIGS. 2 and 3 ), the rotatable knob  16  can be rotated in a first rotational direction indicated by the arrow A 1  in  FIGS. 1B ,  2 , and  3  and in its opposite direction, i.e., a second rotational direction indicated by the arrow A 2  in  FIGS. 1B ,  2 , and  3 . 
     The click generating section  18  is disposed behind the rotatable knob  16 , and generates in cooperation with the click mechanism  12  a click feel as the rotatable knob  16  is being rotated. Specifically, in the disclosed embodiment, the click generating section  18  is configured with an outer circumferential face provided with smoothly linked concave and convex portions in which a convex portion  18   a  and a concave portion  18   b  are repeated in a circumferential direction of rotation, which is a direction corresponding to the rotational directions of the rotatable operation member  10 , and a back face (a face on which the switch driving sections  20  described below are arranged)  18   c  that is a flat face orthogonal to the operation central axis X. Meanwhile, in the disclosed embodiment, the click mechanism  12  is provided with a contact ball  26  that is in contact with the outer circumferential face of the click generating section  18  and a body section  28  that holds and presses the contact ball  26  against the outer circumferential face, and, when the contact ball  26  moves back and forth in the radial directions of the rotatable operation member  10  along the concave and convex portions of the click generating section  18 , a click feel is given to the user, that is, the person who is holding the rotatable knob  16 . 
     The switch driving sections  20  are respectively arranged at a plurality of positions that are intermittently arranged in the circumferential direction of rotation of the rotatable operation member  10 , and protrude rearward (in a direction parallel to the operation central axis X) from the back face  18   c  of the click generating section  18 . The switch driving sections  20  drive the rotation detection switch  14  such that, as the rotatable operation member  10  is being rotated, the rotation detection switch  14  intermittently outputs a rotation detection signal corresponding to the rotational direction. Their specific shape will be described later. 
     The switch driving sections  20  may protrude forward. For example, the outer diameter of the click generating section  18  may be set larger than the outer diameter of the rotatable knob  16 , and the switch driving sections  20  may protrude from a portion of the front face of the click generating section  18  protruding outward in the radial directions beyond the rotatable knob  16 . Alternatively, even in the case where the click generating section  18  and the click mechanism  12  are omitted, it is sufficient that the switch driving sections  20  are arranged at appropriate locations on the rotatable operation member  10 . 
     The rotation detection switch  14  in the disclosed embodiment is disposed behind (on the rear side of) the rotatable operation member  10 , is mounted on the circuit board  24  behind the panel  22 , and includes a detector  30  and a switch body  32 . 
     The detector  30  is driven through sequential contact with the switch driving sections  20  when the rotatable operation member  10  is being rotated. The detector  30  according to this embodiment has a tip end and a base end, and is shaped such that the cross-sectional area becomes smaller from the base end toward the tip end. 
     The switch body  32  can be provided with a box-like casing. This casing is fixed to the circuit board  24 , and holds the detector  30  in a swingable manner. Specifically, the base end of the detector  30  is held such that the detector  30  moves in both a first downward direction and a second downward direction that are mutually opposite (that is, is swung) about an origin position at which the detector  30  is in an upright posture. Furthermore, this casing accommodates a spring mechanism (not shown) that is for biasing the detector  30  toward the origin position and a signal generating section that generates a detection signal. The signal generating section outputs a first detection signal each time the detector  30  moves downward in the first downward direction by at least a predetermined amount, and outputs a second detection signal, which is different from the first detection signal, each time the detector  30  moves downward in the second downward direction, which is opposite the first downward direction, by at least the predetermined amount. These detection signals are input to the circuit board  24  as detection signals of the rotational direction and the rotational amount of the rotatable operation member. 
     As the rotation detection switch  14 , for example, a well-known bidirectional switch as shown in  FIG. 15  may be used as it is. That is to say, the rotation detection switch according to present disclosure may be any switch including a detector that can move to both sides from a predetermined origin position and a switch body that holds the detector in such a manner that the movement of the detector is allowed, wherein the switch body outputs a detection signal corresponding to a rotational direction and a rotational amount of the detector. 
     Furthermore, the movement of the detector  30  of the rotation detection switch  14  is not limited to the above-described upward and downward movement (swing movement). For example, the movement may be parallel movement (e.g., linear movement) from the origin position in a first movement direction on one side and in a second movement direction on the other side. 
     The arrangement position and the arrangement posture of the rotation detection switch  14  are set so as to satisfy the following conditions: a. the switch driving sections  20  are sequentially brought into contact with the detector  30  as the rotatable operation member is being rotated; and b. the first downward direction and the second downward direction of the detector  30  match the radial directions of rotation of the rotatable operation member  10 , that is, directions orthogonal to the circumferential direction of rotation and along the radius of rotation of the rotatable operation member  10 . In this embodiment, the directions are set such that the first downward direction matches a direction that is along a radial direction of rotation toward the outer side, and the second downward direction matches a direction that is along a radial direction of rotation toward the inner side. 
     Meanwhile, the shape of the switch driving sections  20  is set so as to satisfy the following conditions. 
     a. When brought into contact with the detector  30  as the rotatable operation member  10  is being rotated in the first rotational direction (the arrow A 1  direction), a switch driving section  20  moves the detector  30  downward in the first downward direction by at least the predetermined amount. Subsequently, the switch driving section  20  moves away from and releases the detector  30 . 
     b. When brought into contact with the detector  30  as the rotatable operation member  10  is being rotated in the second rotational direction (the arrow A 2  direction), a switch driving section  20  moves the detector  30  downward in the second downward direction by at least the predetermined amount. Subsequently, the switch driving section  20  moves away from and releases the detector  30 . 
     Specifically, the switch driving sections  20  according to this embodiment are each in the shape of a blade that extends in a direction inclined with respect to both the circumferential direction of rotation and the radial direction of rotation of the rotatable operation member  10 . As shown in  FIG. 4B , the two side faces in the width direction of the switch driving section  20  form a first guide face  20   a  and a second guide face  20   b  in the shape of mutually parallel plates, one end portion in the longitudinal direction forms an outer end face  20   c  positioned on the outer side in the radial direction of rotation of the rotatable operation member  10 , and the other end portion forms an inner end face  20   d  positioned on the inner side in the radial direction of rotation. 
     The first guide face  20   a  is a face that is brought into contact with the detector  30  when the rotatable operation member  10  is rotated in the first rotational direction. The angle of inclination of the first guide face  20   a  is set such that, as the rotation progresses, the first guide face  20   a  slides along the detector  30  and guides the detector  30  in the first downward direction (the outer side in the radial direction of rotation of the rotatable operation member  10 ) ( FIGS. 5A and 5B ). Furthermore, the position of the outer end face  20   c  is set such that, after the detector  30  moves downward in the first downward direction by at least the predetermined amount, the detector  30  climbs the outer end face  20   c  ( FIGS. 6A and 6B ), and, as the rotation further progresses, surmounts the outer end face  20   c  and is released (moved away) from the switch driving section  20 . 
     The second guide face  20   b  is a face that is brought into contact with the detector  30  when the rotatable operation member  10  is rotated in the second rotational direction. The angle of inclination of the second guide face  20   b  is set such that, as the rotation progresses, the second guide face  20   b  slides along the detector  30  and guides the detector  30  in the second downward direction (the inner side in the radial direction of rotation of the rotatable operation member  10 ). Furthermore, the position of the inner end face  20   d  is set such that, after the detector  30  moves downward in the second downward direction by at least the predetermined amount, the detector  30  climbs the inner end face  20   d , and, as the rotation further progresses, surmounts the inner end face  20   d  and is released (moved away) from the switch driving section  20 . 
     The shape of the switch driving sections  20  is not limited to the above-described shape that allows the detector  30  to climb the outer end face  20   c  and the inner end face  20   d . For example, the protrusion amount of the switch driving section  20  may be set such that, as the detector  30  moves downward, the detector  30  climbs a rear end face  20   e  of the switch driving section  20 . 
     Next, the operation of an exemplary rotation detection device will be described. 
     In a state where the detector  30  of the rotation detection switch  14  is positioned between given two switch driving sections  20 , more specifically, is positioned between the first guide face  20   a  of a given switch driving section  20  and the second guide face  20   b  of its adjacent switch driving section  20  and is not in contact with either the face  20   a  or the face  20   b  as shown in  FIG. 4B , the detector  30  is held at the origin position in the upright posture as shown in  FIG. 4A . In this state, the rotation detection switch  14  outputs no detection signal. 
     In this state, if the rotatable operation member  10  is rotated in the first rotational direction indicated by the arrow A 1  in  FIGS. 2 to 4 , the first guide face  20   a  of the switch driving section  20  that is adjacent on the upstream side in the rotational direction (the right side in  FIG. 4B ) to the detector  30  is brought into contact with the detector  30 , and guides the detector  30  to the outer side in the radial direction of rotation of the rotatable operation member  10 . Specifically, while sliding along the detector  30 , the first guide face  20   a  moves the detector  30  downward in the first downward direction ( FIGS. 5A and 5B ). 
     When the rotation progresses and the amount by which the detector  30  moves downward in the first downward direction reaches the predetermined amount, the switch body  32  of the rotation detection switch  14  outputs a first detection signal. After further moving downward, the detector  30  climbs the outer end face  20   c  of the switch driving section  20  ( FIGS. 6A ,  6 B,  7 A, and  7 B), and, finally, surmounts the outer end face  20   c  and is released from the switch driving section  20 . Accordingly, the detector  30  returns to the original origin position, and returns the first detection signal from on to off. Furthermore, the detector  30  starts to be in contact with the first guide face  20   a  of the next switch driving section  20 , and repeats the above-described movement. Accordingly, the first detection signal of the rotation detection switch  14  is repeatedly turned on and off. 
     On the other hand, if the rotatable operation member  10  is rotated in the second rotational direction indicated by the arrow A 2  in  FIGS. 2 to 4 , this time, the second guide face  20   b  of the switch driving section  20  that is adjacent to the detector  30  on the side opposite the previous side is brought into contact with the detector  30 , and the detector  30  is guided to the inner side in the radial direction of rotation of the rotatable operation member  10  while sliding along the second guide face  20   b . That is to say, the detector  30  starts to move downward in the second downward direction. Then, when the amount of the downward movement reaches the predetermined amount, the rotation detection switch  14  outputs a second detection signal, which is different from the first detection signal. After further moving downward, the detector  30  climbs the inner end face  20   d  of the switch driving section  20 . Subsequently, the detector  30  surmounts the inner end face  20   d , and is thus released from the switch driving section  20 . Thus, the detector  30  returns to the original origin position, and turns the second detection signal off. Accordingly, the second detection signal is repeatedly turned on and off. 
     According to a feature of this rotatable operation device, the rotation detection switch  14  is disposed in a posture in which the movement directions of the detector  30  of the rotation detection switch  14  (the first downward direction and the second downward direction in this embodiment) match the radial directions of rotation of the rotatable operation member  10  orthogonal to the circumferential direction of rotation, and the shape of the switch driving sections  20  is set such that the detector  30  is moved downward in the above-described directions. Accordingly, it is possible to ensure a sufficient movement stroke of the detector  30  while realizing a small interval between the switch driving sections  20  arranged in the circumferential direction of rotation, that is, a small rotation detection pitch. 
     For example, in a conventional rotation detection device as shown in  FIG. 15 , the movement directions (swing directions) of the detector  88  of the rotation detection switch  84  match the circumferential directions of rotation of the rotatable operation member, and, thus, in order to ensure a movement stroke of the detector  88 , it is unavoidable to set a large interval between the switch driving sections  82  (the arrangement pitch Pt). On the other hand, in the device shown in  FIGS. 1 to 7 , the rotation detection switch  14  is disposed in a posture in which the movement directions (upward and downward directions, i.e., swing directions) of the detector  30  match the radial directions of rotation of the rotatable operation member  10 , or rather is orthogonal to the circumferential direction of rotation, and, thus, the required movement distance of the detector  30  in the circumferential direction of rotation becomes substantially 0. Similar configuration can be achieved for other types of detectors. For example, a linearly moving switch and accompanying detector need only be configured such that the movement direction of the detector be oblique, and more preferably, orthogonal to the linear movement of the device whose movement is being detected. Accordingly, the limitation to the reduction in the arrangement pitch of the switch driving sections  20 , that is, the rotation detection pitch in the circumferential direction of rotation, the limitation being caused by the required movement distance of the detector  30 , is eliminated, and the pitch can be significantly reduced. 
     Furthermore, in the case where the click mechanism  12  and the click generating section  18  as shown in the drawings are provided and they generate a click feel at the same pitch as the rotation detection pitch, it is also possible to improve a sense of operation given to the user by reducing the click feel generation pitch according to the reduction in the rotation detection pitch. 
     Next, a second embodiment of the present disclosure will be described with reference to  FIGS. 8 to 13 . Note that the configuration of the device according to the second embodiment is the same as that of the device according to the first embodiment, except for the specific shape and arrangement of the switch driving sections and the specific arrangement of the rotation detection switch, and, thus, the corresponding constituent elements are denoted by the same reference numerals, and their further description has been omitted. Hereinafter, mainly differences between the devices according to these embodiments will be described. 
     The differences in the configuration of the device according to the second embodiment are as follows. 
     A. Regarding the Arrangement of the Switch Driving Sections 
     In the device according to the second embodiment, a portion having a cylindrical outer circumferential face (arrangement face)  34  centered about the operation central axis X is disposed at the rear end of the click generating section  18  in the rotatable operation member  10 , and a plurality of switch driving sections  36  are arranged on the outer circumferential face  34 . The switch driving sections  36  are intermittently arranged in the circumferential direction of rotation of the rotatable operation member  10 , and protrude outward in the radial directions of rotation from the outer circumferential face  34 . 
     The switch driving sections  36  also may protrude inward in the radial directions. For example, the click generating section  18  may be in the shape of a hollow cylinder, and the switch driving sections  36  may protrude inward from the inner circumferential face of the click generating section  18 . Furthermore, even in the case where the click generating section  18  and the click mechanism  12  are omitted, it is sufficient that the switch driving sections  36  are arranged at appropriate locations on the rotatable operation member  10 . 
     B. Regarding the Arrangement of the Rotation Detection Switch  14   
     In this particular embodiment, the rotation detection switch  14  is disposed not behind (on the rear side of) the rotatable operation member  10  but at a position on the outer side in the radial direction such that the switch driving sections  36  are sequentially brought into contact with the detector  30  as the rotatable operation member  10  is being rotated. The posture of the rotation detection switch  14  is set such that the movement directions of the detector  30  (the first downward direction and the second downward direction) match directions parallel to the operation central axis X of the rotatable operation member  10 , that is, the front and rear directions. More specifically, in this embodiment, the first downward direction of the detector  30  is set so as to mach the rear direction (the direction toward the circuit board  24 ) of the directions (front and rear directions) parallel to the operation central axis X, and the second downward direction is set so as to mach the front direction (the direction toward the panel  22 ). 
     C. Regarding the Arrangement of the Switch Driving Sections 
     The shape of the switch driving sections  36  is set so as to satisfy the following conditions. 
     a. When brought into contact with the detector  30  as the rotatable operation member  10  is being rotated in the first rotational direction (the arrow A 1  direction), a switch driving section  36  moves the detector  30  downward in the first downward direction by at least the predetermined amount. Subsequently, the switch driving section  36  moves away from and releases the detector  30 . 
     b. When brought into contact with the detector  30  as the rotatable operation member  10  is being rotated in the second rotational direction (the arrow A 2  direction), a switch driving section  36  moves the detector  30  downward in the second downward direction by at least the predetermined amount. Subsequently, the switch driving section  36  moves away from and releases the detector  30 . 
     Specifically, the switch driving sections  36  according to this embodiment are each in the shape of a blade that extends in a direction inclined with respect to both the circumferential direction of rotation of the rotatable operation member  10  and the direction parallel to the operation central axis X. As shown in  FIG. 10B , the two side faces in the width direction of the switch driving section  36  form a first guide face  36   a  and a second guide face  36   b  in the shape of mutually parallel plates, one end portion in the longitudinal direction forms a rear end face  36   c  positioned on the rear side in the direction (front-and-rear direction) parallel to the operation central axis X, and the other end portion forms a front end face  36   d  positioned on the inner side in the radial direction of rotation. 
     The first guide face  36   a  is a face that is brought into contact with the detector  30  when the rotatable operation member  10  is rotated in the first rotational direction. The angle of inclination of the first guide face  36   a  is set such that, as the rotation progresses, the first guide face  36   a  slides along the detector  30  and guides the detector  30  in the first downward direction (the rear direction of the rotatable operation member  10 ) ( FIGS. 11A and 11B ) Furthermore, the position of the rear end face  36   c  of the switch driving section  36  is set such that, after the detector  30  moves downward in the first downward direction by at least the predetermined amount, the detector  30  climbs the rear end face  36   c  ( FIGS. 12A and 12B ), and, as the rotation further progresses, surmounts the rear end face  36   c  and is released (moved away) from the switch driving section  36 . 
     The second guide face  36   b  is a face that is brought into contact with the detector  30  when the rotatable operation member  10  is rotated in the second rotational direction. The angle of inclination of the second guide face  36   b  is set such that, as the rotation progresses, the second guide face  36   b  slides along the detector  30  and guides the detector  30  in the second downward direction (the front direction of the rotatable operation member  10 ). Furthermore, the position of the front end face  36   d  of the switch driving section  36  is set such that, after the detector  30  moves downward in the second downward direction by at least the predetermined amount, the detector  30  climbs the front end face  36   d , and, as the rotation further progresses, surmounts the front end face  36   d  and is released (moved away) from the switch driving section  36 . 
     The shape of the switch driving sections  36  according to this embodiment is not limited to the above-described shape that allows the detector  30  to climb the rear end face  36   c  and the front end face  36   d . For example, the protrusion amount of the switch driving section  36  may be set such that, as the detector  30  moves downward, the detector  30  climbs an outer end face  36   e  of the switch driving section  36 . 
     Next, the operation of this rotation detection device will be described. 
     First, in a state where the detector  30  of the rotation detection switch  14  is positioned between given two switch driving sections  36 , more specifically, is positioned between the first guide face  36   a  of a given switch driving section  36  and the second guide face  36   b  of its adjacent switch driving section  36  and is not in contact with either the face  36   a  or the face  36   b  as shown in  FIG. 10B , the detector  30  is held at the origin position in the upright posture as shown in  FIG. 10A . In this state, the rotation detection switch  14  outputs no detection signal. 
     In this state, if the rotatable operation member  10  is rotated in the first rotational direction indicated by the arrow A 1  in  FIGS. 8 to 10 , the first guide face  36   a  of the switch driving section  36  that is adjacent on the upstream side in the rotational direction (the lower side in  FIG. 10B ) to the detector  30  is brought into contact with the detector  30 , and guides the detector  30  to the rear side of the rotatable operation member  10 . Specifically, while sliding along the detector  30 , the first guide face  36   a  moves the detector  30  downward in the first downward direction ( FIGS. 11A and 11B ). 
     When the rotation progresses and the amount by which the detector  30  moves downward in the first downward direction reaches the predetermined amount, the switch body  32  of the rotation detection switch  14  outputs a first detection signal. After further moving downward, the detector  30  climbs the rear end face  36   c  of the switch driving section  36  ( FIGS. 12A ,  12 B,  13 A, and  13 B), and, finally, surmounts the rear end face  36   c  and is released from the switch driving section  36 . Accordingly, the detector  30  returns to the original origin position, and returns the first detection signal from on to off. Furthermore, the detector  30  starts to be in contact with the first guide face  36   a  of the next switch driving section  36 , and repeats the above-described movement. Accordingly, the first detection signal of the rotation detection switch  14  is repeatedly turned on and off. 
     On the other hand, if the rotatable operation member  10  is rotated in the second rotational direction indicated by the arrow A 2  in  FIGS. 8 to 10 , the second guide face  36   b  of the switch driving section  36  is brought into contact with the detector  30 , and the detector  30  is guided to the front side of the rotatable operation member  10  while sliding along the second guide face  36   b  and starts to move downward in the second downward direction. Then, when the amount of the downward movement reaches the predetermined amount, the rotation detection switch  14  outputs a second detection signal, which is different from the first detection signal. After further moving downward, the detector  30  climbs the front end face  36   d  of the switch driving section  36 . Subsequently, the detector  30  surmounts the front end face  36   d , and is thus released from the switch driving section  36 . Thus, the detector  30  returns to the original origin position, and turns the second detection signal off. Accordingly, the second detection signal is repeatedly turned on and off. 
     Also in the rotation detection device according to the second embodiment, the rotation detection switch  14  is disposed in a posture in which the movement directions of the detector  30  of the rotation detection switch  14  (the first downward direction and the second downward direction in this embodiment) match the front and rear directions (the directions parallel to the operation central axis X) orthogonal to the circumferential direction of rotation of the rotatable operation member  10 , and the shape of the switch driving sections  36  is set such that the detector  30  is moved downward in the above-described directions. Accordingly, it is possible to ensure a sufficient movement stroke of the detector  30  while realizing a small interval between the switch driving sections  36  arranged in the circumferential direction of rotation, that is, a small rotation detection pitch. 
     Note that, in the present disclosure, the movement directions of the detector (downward directions in the foregoing embodiments) do not necessarily have to match directions (the radial directions of rotation in the first embodiment and the directions parallel to the operation central axis X in the second embodiment) orthogonal to the circumferential direction of rotation of the rotatable operation member, and may be any direction as long as they are oblique, and more preferably closer to a direction orthogonal to the movement direction, i.e., orthogonal to the circumferential direction of rotation than to the circumferential direction of rotation. If the movement directions of the detector are set in this manner, the limitation to the reduction in the arrangement pitch of the switch driving sections, that is, the rotation detection pitch can be alleviated compared with that in a conventional rotation detection device (i.e., device in which the movement directions of a rotation detection switch match the circumferential directions of rotation), and the degree of freedom in reducing the pitch can be accordingly increased. 
     As described above, the present disclosure provides a rotatable operation device, including a rotatable operation member and a rotation detection switch that detects rotation of the rotatable operation member, wherein the rotation detection pitch can be reduced while a proper operation of the rotation detection switch is ensured. 
     Specifically, the rotation detection device provided by the present disclosure includes a rotatable operation member that can be rotated in both a first rotational direction and a second rotational direction, which is opposite the first rotational direction, about a given operation central axis, and a rotation detection switch that detects a rotational direction and a rotational amount of the rotatable operation member. The rotatable operation member includes a plurality of switch driving sections that are intermittently arranged in a circumferential direction of the rotatable operation member. The rotation detection switch is provided with a detector and a switch body. The switch body holds the detector such that the detector can move in both a first movement direction and a second movement direction, which are opposite each other, from an origin position at which the detector is in an upright posture, biases the detector toward the origin position, and, each time the detector moves in the first movement direction or the second movement direction by a predetermined amount, outputs a detection signal corresponding to the movement direction. The rotation detection switch is disposed in a posture in which the first movement direction and the second movement direction of the detector are closer to a direction (a radial direction of rotation of the rotatable operation member, or a direction parallel to the operation central axis) orthogonal to the circumferential direction of rotation of the rotatable operation member than to the circumferential direction of rotation at a position where the switch driving sections of the rotatable operation member can be brought into contact with the detector. The switch driving sections of the rotatable operation member are each shaped such that, when brought into contact with the detector as the rotatable operation member is being rotated in the first rotational direction, the switch driving sections move the detector in the first movement direction by at least the predetermined amount and then release the detector, and such that, when brought into contact with the detector as the rotatable operation member is being rotated in the second rotational direction, the switch driving sections move the detector in the second movement direction by at least the predetermined amount and then release the detector. 
     In this rotatable operation device, since the rotation detection switch is disposed in a posture in which the movement directions of the detector (the first movement direction and the second movement direction) are closer to a direction (a radial direction of rotation of the rotatable operation member, or a direction parallel to the operation central axis) orthogonal to the circumferential direction of rotation of the rotatable operation member than to the circumferential direction of rotation, it is possible to ensure a sufficient movement stroke of the detector while realizing a small interval between the switch driving sections arranged in the circumferential direction of rotation, that is, a small rotation detection pitch. That is to say, in a conventional rotatable operation device, since the rotation detection switch is disposed such that the circumferential direction of rotation of the rotatable operation member and the arrangement direction of the switch driving sections (e.g., the driving protrusions  82  in the device shown in  FIG. 15 ) match the movement directions of the detector of the rotation detection switch (the swing directions of the detector  88  in the device shown in  FIG. 15 ), a large interval between the switch driving sections has to be ensured in order to ensure a movement stroke of the detector, but, in the device according to the present disclosure, since the posture of the rotation detection switch is determined such that the movement directions of the detector are closer to a direction orthogonal to the circumferential direction of rotation of the rotatable operation member than to the circumferential direction of rotation, the required movement distance of the detector in the circumferential direction of rotation is short, and the arrangement pitch of the switch driving sections, that is, the rotation detection pitch in the circumferential direction of rotation can be accordingly reduced. 
     In particular, if the rotation detection switch is disposed such that the movement directions of the detector match directions orthogonal to the circumferential direction of rotation of the rotatable operation member, the required movement distance of the detector in the circumferential direction of rotation of the rotatable operation member becomes substantially 0. Accordingly, the arrangement pitch of the switch driving sections in the circumferential direction of rotation can be significantly reduced. 
     The specific shape of each of the switch driving sections is preferably set so as to have: a first guide face that is inclined with respect to the circumferential direction of rotation of the rotatable operation member such that, when the rotatable operation member is rotated in the first rotational direction, the first guide face is brought into contact with the detector, and guides the detector in the first movement direction while sliding along the detector; and a second guide face that is inclined with respect to the circumferential direction of rotation of the rotatable operation member such that, when the rotatable operation member is rotated in the second rotational direction, the second guide face is brought into contact with the detector, and guides the detector in the second movement direction while sliding along the detector. Such switch driving sections have a simple shape, but can move the detector in directions corresponding to the rotational directions of the rotatable operation member. 
     It is sufficient that the movement directions of the detector of the rotation detection switch with respect to the rotatable operation member are set according to the state where the switch driving sections are arranged on the rotatable operation member. For example, the rotatable operation member may have an arrangement face orthogonal to an operation central axis of the rotatable operation member, and the switch driving sections may protrude in a direction parallel to the operation central axis from the arrangement face. In this case, it is sufficient that the rotation detection switch is disposed such that, when the switch driving sections are brought into contact with the detector, the detector moves in a direction closer to a radial direction of rotation of the rotatable operation member than to the circumferential direction of rotation. Alternatively, the rotatable operation member may have a cylindrical arrangement face centered about an operation central axis of the rotatable operation member, and the switch driving sections may protrude in radial directions of rotation of the rotatable operation member from the arrangement face. In this case, it is sufficient that the rotation detection switch is disposed such that, when the switch driving sections are brought into contact with the detector, the detector moves in a direction closer to a direction parallel to the operation central axis than to the circumferential direction of rotation of the rotatable operation member.