Patent Publication Number: US-2013241579-A1

Title: Input device

Description:
CLAIM OF PRIORITY 
     This application claims benefit of Japanese Patent Application No. 2012-057418 filed on Mar. 14, 2012, which is hereby incorporated by reference in its entirety. 
     BACKGROUND OF THE DISCLOSURE 
     1. Field of the Disclosure 
     The present disclosure relates to an input device having an operating body capable of at least a rotating operation, and in particular to an input device provided with a capacitive sensor which detects an operator&#39;s approach to or touch on the rear surface side of the operating body. 
     2. Description of the Related Art 
     As an input device provided on a center console of vehicles and the like, there is a known device which performs an input together with a rotating operation of a operating body using an operator&#39;s approach or touch with respect to a top side portion of the operating body, in such a manner that the operating body capable of the rotating operation with respect to a base member is provided, the operating body is formed in a bottomed cylinder shape which has the top side portion, and a capacitive sensor which detects the operator&#39;s approach or touch with respect to the top side portion is provided on the rear surface side of the top side portion configuring the operating body. Such an input device may include the one disclosed in PCT Japanese Translation Patent Publication No. 2011-526385. 
     An enhanced design for an input device can be realized using metal plating on an operating body made of resin materials, by allowing at least a portion of the surface of the operating body to have a metallic appearance. However, if the operating body has a metal portion, an operator&#39;s touch on the metal portion affects the operation of a capacitive sensor. This is because the capacitance value between the metal portion having conductivity and the ground is changed from an extremely small state to a state passing through the human body and consequently affects the capacitance value of the capacitive sensor as well, which may lead to a malfunction of the capacitive sensor. 
     Originally, this matter can be avoided by constantly grounding the metal portion formed on the operating body. However, it is difficult to constantly ground the metal portion formed on the operating body capable of a rotating operation with respect to a base member. Therefore, in the input device having the capacitive sensor, the metal portion could not have been formed for the operating body capable of the rotating operation. In addition, without being limited to the rotating operation, even the operating body freely movable with respect to the capacitive sensor has the similar problem. 
     SUMMARY 
     An input device includes a capacitive sensor which detects an operator&#39;s approach or touch; and an operating body which is movably supported with respect to the capacitive sensor. 
     The operating body is arranged so as to surround the capacitive sensor, at least a portion of the operating body has a conductive material portion exposed to a surface, and a base member unmovable with respect to the capacitive sensor has a capacitive coupling portion opposing the conductive material portion and the capacitive coupling portion is grounded. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front view of a center console having an input device according to an embodiment. 
         FIG. 2  is an enlarged view of an input device portion in the cross section A-A in  FIG. 1 . 
         FIG. 3  is an enlarged view of an input device portion in the cross section B-B in  FIG. 1 . 
         FIG. 4  is an exploded perspective view of an operating body, a base member, a capacitive sensor, a flexible substrate, a first substrate, a second substrate and a rotating support member. 
         FIG. 5  is a schematic plan view illustrating the positional relationship of a capacitive sensor, a conductive material portion and a capacitive coupling portion. 
     
    
    
     DESCRIPTION OF THE EXEMPLARY EMBODIMENTS 
     Embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG.  1  illustrates a front view of a center console  1  having an input device  2  according to an embodiment. The center console  1  is arranged between the driver&#39;s seat and the front passenger&#39;s seat, and the input device  2  performing various inputs is arranged on the surface thereof. 
     The input device  2  of the present embodiment is configured such that an operating body  10  having a bottomed cylinder shape is exposed inside a vehicle, the operating body  10  is capable of a rotating operation along the circumferential direction, and additionally capable of a pressing operation in the direction perpendicular to the surface of the center console  1 , and a capacitive sensor  15  provided on the rear side of a top side portion  10   a  can detect the approach or touch of the operator&#39;s fingers with respect to the surface of the top side portion  10   a  of the operating body  10 . 
     Respectively,  FIG. 2  illustrates an enlarged view of the input device  2  portion in the cross section A-A in  FIG. 1 ,  FIG. 3  illustrates an enlarged view of the input device  2  portion in the cross section B-B in  FIG. 1 , and  FIG. 4  illustrates an exploded perspective view of the operating body  10 , a base member  11 , the capacitive sensor  15 , a flexible substrate  21 , s first substrate  16 , a second substrate  17  and a rotating support member  19 . The input device  2  is configured by the base member  11  fixed to the vehicle and supporting the capacitive sensor  15 , and the operating body  10  supported so as to be rotatably movable with respect to the base member  11 . That is, the operating body  10  configures a side rotatably movable with respect to the capacitive sensor  15 , and the base member  11  configures a side not rotatably movable with respect to the capacitive sensor  15 . Here, the base member  11  holds the capacitive sensor  15  by means not illustrated. 
     The base member  11  configuring the side not rotatably movable with respect to the capacitive sensor  15  is formed of three components of a support portion  12 , a cylindrical portion  13  and a bottom surface portion  14 . The support portion  12  supports the capacitive sensor  15  on the upper surface side and is formed so as to have a substantially ring shape. The cylindrical portion  13  is formed so as to have a substantially columnar shape and the capacitive sensor  15  is in a housed state in the upper end portion of the inner peripheral surface thereof. 
     The first substrate  16  is fixed to the lower surface side of the support portion  12 . In addition, the second substrate  17  is fixed below the first substrate  16 . Electrical components required for operating the capacitive sensor  15 , a light emitter emitting light during the operation or the like are arranged on the first substrate  16 . The electrical components or the like for detecting the rotation of the operating body  10  are arranged on the second substrate  17 . The bottom surface  14  supports the lower surface side of the second substrate  17  and is formed so as to have a substantially disk shape. 
     The rotating support member  19  rotatable together with the operating body  10  is arranged at the lower portion of the bottom surface portion  14 . The rotating support member  19  is rotatably supported with respect to the vehicle and is fixedly fitted to the operating body  10 . That is, the rotating support member  19  configures the side rotatably movable with respect to the capacitive sensor  15 . The rotating support member  19  has convex portions  19   a  on its upper surface. The convex portions  19   a  are plurally formed along the circumferential direction of the rotating support member  19 . 
     As illustrated in  FIG. 2 , a rotating detection portion  18  with a concave cross section is provided at two places of the lower surface side of the second substrate  17  and is arranged so as to insert the convex portions  19   a  of the rotating support member  19  to the rotating detection portion  18 . The rotating detection portion  18 , where optical sensors are arranged on both inner side surfaces with a concave shape, can detect that the rotating support member  19  is rotated together with the operating body  10  and the convex portions  19   a  passes through the inside of the rotating detection portion  18 . During the rotation of the rotating support member  19 , the convex portions  19   a  are arranged so as to pass through each rotating detection portion  18  at a different timing, and the rotating direction of the rotating body  10  can be determined from a phase difference of detected signals. In addition, it is possible to detect the rotation amount of the operating body  10  by counting the number of passes of the convex portions  19   a.    
     The cylindrical portion  13  configuring the base member  11  allows the inside thereof to accommodate the capacitive sensor  15  and the first substrate  16 , and the second substrate  17  are arranged at the lower surface side thereof. Then, the operating body  10  is arranged so as to surround the outer peripheral surface  13   a  of the cylindrical portion  13  and the capacitive sensor  15 . 
     The operating body  10  includes the top side portion  10   a  and the lateral side portion  10   b  configuring in a cylindrical shape. A plurality of irregularities is formed on the lateral side portion  10   b  along the circumferential direction to facilitate the rotating operation for the operator. In the present embodiment, the top side portion  10   a  and the lateral side portion  10   b  are configured as separate components. However, they may be integrated. The clearance gap portion  25  spaced over the entire periphery is formed between the inner peripheral surface  10   d  of the lateral side portion  10   b  and the outer peripheral surface  13   a  of the cylindrical portion  13 . 
     The operating body  10  is formed from a resin material, but metal plating is applied to the surface of the lateral side portion  10   b . The metal plating is formed over the entire surface of the outer peripheral surface  10   c  and the inner peripheral surface  10   d  of the lateral side portion  10   b , which configures a conductive material portion  20  exposed to the surface, in the operating body  10 , which is the side rotatably movable with respect to the capacitive sensor  15 . 
     In the clearance gap portion  25  formed between the base member  11  and the operating body  10 , on the outer peripheral surface  13   a  of the cylindrical portion  13 , which opposes the inner peripheral surface  10   d  of the operating body  10 , a capacitive coupling portion  22  in capacitive coupling with the conductive material portion  20  is provided along the circumferential direction. The capacitive coupling portion  22  is formed as a conductive pattern on a flexible substrate  21  which is freely deformable with flexibility, and is arranged at the side not rotatably movable with respect to the capacitive sensor  15 , proximately opposing the conductive material portion  20  of the operating body  10 . In addition, since the capacitive coupling portion  22  is provided over the entire periphery of the cylindrical portion  13 , regardless of the rotating movement of the rotating body  10 , the capacitive coupling portion  22  opposes the conductive material portion  20  in a constant distance. In addition, the capacitive coupling portion may not be in the conductive pattern, and may be the one which can be capacitively coupled with the conductive material portion  20 . 
     As illustrated in  FIG. 4 , the flexible substrate  21  includes a winding portion  21   a , which forms a ring shape along the outer peripheral surface  13   a  of the cylindrical portion  13 , and an extending portion  21   b , which is extended from one end portion of the winding portion  21   a  toward the second substrate  17  side. Then, the capacitive coupling portion  22  formed of the continuous conductive pattern from the winding portion  21   a  to the extending portion  21   b  is formed on the surface thereof. 
     In  FIG. 3 , the extending portion  21   b  of the flexible substrate  21  is illustrated. The extending portion  21   b  is drawn from the outer peripheral surface  13   a  of the cylindrical portion  13  to the lower surface side of the second substrate  17 , and the end portion thereof is inserted and fixed with respect to the bottom surface portion  14 . The capacitive coupling portion  22  of the extending portion  21   b  is conductively in contact with a ground terminal of the second substrate  17 , and is in a state of being grounded in the input device  2 . 
     The capacitive sensor  15  is configured such that two electrodes proximately opposing each other forms one pair and multiple pairs of the electrodes are respectively arranged along two directions orthogonal to each other. Then, the capacitive sensor  15  can detect the presence or absence of the operation and operating places by detecting capacitance between the electrodes which is changed due to the approach or touch of the operator&#39;s fingers on the surface of the capacitive sensor  15 . 
     Here, in a case where the conductive material of the grounding object is present in the vicinity of the capacitive sensor  15 , the conductive material is coupled with the ground with very small amount of stray capacitance. However, if the user touches the conductive material, a capacitance value between the conductive material and the ground is changed to a state passing through the human body and consequently the changed capacitance value also causes the change of the capacitance in the capacitive sensor  15 . Accordingly, there is a possibility that the capacitive sensor  15  may erroneously detect the operation. By keeping a sufficiently larger capacitive coupling in advance between the conductive material and the ground than the capacitance value between the conductive material and the capacitive sensor  15 , it is possible to suppress the change of the capacitance in the capacitive sensor  15  when the operator touches the conductive material. 
     In the present embodiment, the conductive material portion  20  formed on the surface of the operating body  10  corresponds to the conductive material, which is present in the vicinity of the capacitive sensor  15 . The operator&#39;s touching on this leads to in the change of the capacitance in the capacitive sensor  15 . Therefore, the capacitive coupling portion  22  capacitively coupled with the conductive material portion  20  is provided on the base member  11 , which is grounded.  FIG. 5  is a schematic plan view illustrating the positional relationship of the capacitive sensor  15 , the conductive material portion  20  and the capacitive coupling portion  22 . 
     In  FIGS. 5 , X 1  to X 8  represent the electrodes arranged along the direction X of the drawing and Y 1  to Y 6  represent the electrodes arranged along the direction Y of the drawing. In this manner, the electrodes detecting the capacitance value are arrayed to form a lattice pattern on the surface of the capacitive sensor  15 . 
     The electrode of the capacitive sensor  15 , which is closest to the conductive material portion  20 , represents X 1  and the distance from this to the conductive material portion  20  represents L 1 . On the other hand, the capacitive coupling portion  22  is formed on the outer peripheral surface  13   a  of the cylindrical portion  13  proximately opposing the inner peripheral surface  10   d  of the operating body  10 , on which the conductive material portion  20  is formed, and the distance from the conductive material portion  20  represents L 2 , which is shorter than L 1 . 
     In addition, the electrode of the capacitive sensor  15  is formed with a very small diameter. Accordingly, an area S 1  opposing the conductive material portion  20  is small. In contrast, the capacitive coupling portion  22  is formed to fit the width of the flexible substrate  21  and thereby the area S 2  opposing the conductive material portion  20  is larger than S 1 . 
     The capacitance value C of the electrodes opposing each other can be expressed by “Capacitance Value C=εS/L”. In other words, the capacitance value C is proportional to an opposing area S of the two and is inversely proportional to a distance L. Accordingly, the capacitance value C 1  of the conductive material portion  20  and the capacitive coupling portion  22 , in which the opposing area S 2  is large and the distance L 2  is short, comes to have the small opposing area S 1 , and becomes larger than the capacitance value C 2  of the conductive material portion  20  and the capacitive sensor  15 , in which the opposing area S 1  is small and the distance L 1  is long. 
     In this way, the operating body  10  having the conductive material portion  20  on its surface is movably provided with respect to the capacitive sensor  15 , and the capacitive coupling portion  22  opposing the conductive material portion  20  regardless of the movement of the operating body  10  is provided on the base member  11  which is the side not movable with respect to the capacitive sensor  15 . By the capacitive coupling portion  22  being grounded, even if the metal portion is provided on the rotating body  10 , the influence due to capacitance fluctuations applied to the capacitive sensor  15  can be decreased and thereby malfunction of the capacitive sensor  15  can be prevented. 
     In the present embodiment, the cylindrical portion  13  is provided on the base member  11  and the capacitive coupling portion  22  is provided on the outer peripheral surface  13   a  of the cylindrical portion  13 . However, the configuration may not include the cylindrical portion  13  in the base member  11 . In any case, even in such a manner that the clearance gap portion is formed between the side not movable with respect to the capacitive sensor and the conductive material portion provided on the operating body, and the capacitive coupling portion is provided in the clearance gap portion, the capacitive coupling portion may be configured to oppose the conductive material portion. 
     In addition, in the present embodiment, the capacitive coupling portion  22  is provided on the outer peripheral surface  13   a  of the cylindrical portion  13 . However, if the capacitance value C 1  of the conductive material portion  20  and the capacitive coupling portion  22  can be sufficiently secured compared to the capacitance value C 2  of the conductive material portion  20  and the capacitive sensor  15 , the capacitive coupling portion may be provided along the lateral surface of the capacitive sensor  15 , alternatively, along the lateral surface of the first substrate  16  or the second substrate  17 . 
     The operating body  10  is not limited to the one which is freely rotatable. A sliding or swinging one may be adopted. Even in those cases, it is possible to suppress the influence with respect to the capacitive sensor by providing and grounding the capacitive coupling portion opposing the conductive material portion on the side not movable with respect to the capacitive sensor. 
     Hitherto, the embodiment of the present invention has been described, but an application of the present invention is not limited to the present embodiment, and the present invention may be variously adopted within the scope of the technical spirit thereof. 
     It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims of the equivalents thereof.