Abstract:
A multi-contact inputting device has a center switch (S 1 ) and plural side switches (S 2 ) that are placed around the center switch (S 1 ). The multi-contact inputting device is used for inputting and outputting different signals by operating an operation member ( 7 ). The movable electrodes ( 41, 42 ) are placed so as to overlap with each other in the thickness direction of the body ( 1 ). Arranging the movable electrodes ( 41, 42 ) in the manner described above, realizes miniaturization and compaction of the multi-contact inputting device. Each of the center switch (S 1 ) and the side switches (S 2 ) is formed by a stationary electrode ( 31, 32 ) and a movable electrode ( 41, 42 ) configured by a snap plate. The movable electrode ( 41 ) of the center switch (S 1 ) and the movable electrodes ( 42 ) of the side switches (S 2 ) are placed so as to overlap with each other in the thickness direction of the body ( 1 ), and hence the size of the body ( 1 ) can be reduced by a degree corresponding to the overlapping width (D).

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a multi-contact inputting device, and more particularly to a multi-contact inputting device which has a center switch and plural side switches that are placed around the center switch, and in which the center switch and the side switches are individually opened and closed by operating an operation member. 
     2. Description of the Prior Art 
     A multi-contact inputting device is used for inputting and outputting different signals by operating one or plural operation members. Among conventional art multi-contact inputting devices of this kind, a device is employed in which each of the center switch and the side switches is formed by combining a stationary electrode, and movable electrodes each configured by a snap plate covering the stationary electrode. In such a device, spaces for respectively accommodating the movable electrodes each configured by a snap plate are formed by partitioning the body so as not to overlap with each other. 
     In the multi-contact inputting device of the conventional art, the body in which the center switch and the side switches are placed must be formed into a size which allows the movable electrodes each configured by a snap plate to be placed so as not to overlap with each other in the thickness direction of the body. Consequently, there arises a situation in which the size of the body is determined by the size and the number of the snap plates forming the movable electrodes. As a result, the concept that the movable electrodes each configured by a snap plate are placed so as not to overlap with each other in the thickness direction of the body constitutes one of obstacles to reduce the size of the body so as to attain miniaturization and compaction of the whole shape of a multi-contact inputting device. 
     SUMMARY OF THE INVENTION 
     The present invention has been conducted in view of the above-mentioned circumstances under the concept that, unlike the conventional art, movable electrodes constituting a center switch and plural side switches and each configured by a snap plate are placed so as to overlap with each other in the thickness direction of the body. 
     It is an object of the invention to arrange movable electrodes in the manner described above, whereby miniaturization and compaction of the whole shape of a multi-contact inputting device are easily realized. 
     It is another object of the invention to prevent movable electrodes of a center switch and side switches from being positionally deviated, to enhance their operation reliability. 
     It is a further object of the invention to enable such movable electrodes to be positioned without increasing the number of parts. 
     It is a still further object of the invention to prevent a situation in which a movable electrode of each of side switches that is placed overlapping with a movable electrode of a center switch interferes with the movable electrode of the center switch to damage the movable electrodes, from occurring even when the movable electrode of the side switch is operated via an operation member to be flexurally deformed. 
     Referring to the accompanying drawings, the multi-contact inputting device of the invention will be described. The reference numerals in the figures are used in this paragraph in order to facilitate the understanding of the invention, and the use of the reference numerals is not intended to restrict the contents of the invention to the illustrated embodiments. 
     The multi-contact inputting device according to the invention has a center switch S 1 , and plural side switches S 2  which are placed around the center switch S 1 . Each of the center switch S 1  and the plural side switches S 2  is formed by: a stationary electrode  31  or  32  disposed in a body  1 ; and a stationary electrode  41  or  42  configured by a snap plate which is placed so as to be separable from and contactable with the stationary electrode  31  or  32 , and to cover the stationary electrode  31  or  32 . The device further comprises an operation member  7  which can individually open and close the center switch S 1  and the side switches S 2 . A plurality of such operation members may be provided for each of the center switch and the side switches. Alternatively, a single operation member which can individually operate the center switch and the plural side switches may be provided. 
     In the multi-contact inputting device according to the invention, the plural side switches S 2  are placed so that a part of the movable electrode  42  of each of the side switches overlaps with the movable electrode  41  of the center switch S 1  in a thickness direction of the body  1 . When this configuration is employed, the spaces for respectively accommodating the movable electrodes  41  and  42  can be narrowed by a length corresponding to the overlapping width D of the electrodes, as compared with a configuration such as that of the conventional multi-contact inputting device described in the beginning, in which the movable electrode of the center switch and the movable electrodes of the plural side switches are placed so as not to overlap with each other in the thickness direction of the body. This is useful for reducing the size of the body  1  to expedite miniaturization and compaction of the whole shape of a multi-contact inputting device. In the invention, the movable electrode of the center switch S 1  may be placed so as to overlap above the movable electrodes of the plural side switches S 2 , or alternatively the movable electrodes of the plural side switches S 2  may be placed so as to overlap above the movable electrode of the center switch S 1 . 
     In the invention, it is preferable to dispose positioning means for positioning the movable electrode  41  of the center switch S 1  and the movable electrodes  42  of the side switches S 2  to predetermined positions which are formed by partitioning the body  1 . According to this configuration, positional relationships among the movable electrodes  41  and  42  of the center switch S 1  and the side switches S 2  are suitably defined, and hence a situation in which any one of the movable electrodes  41  and  42  is positionally deviated to impair the operation reliability does not occur. 
     In the invention, preferably, a recess  22  into which the movable electrode  41  of the center switch S 1  is to be fitted, and recesses  21  into which the movable electrodes  42  of the side switches S 2  are to be respectively fitted are disposed in the body  1 , and the positioning means is formed by the recesses  22  and  21 . When the movable electrodes  41  and  42  are fitted into the recesses  22  and  21  formed in the body  1  so as to perform positioning as described above, extra parts for positioning the movable electrodes  41  and  42  are not necessary, and hence it is possible to prevent the body structure from being complicated. 
     In the case where the positioning means for the movable electrodes  41  and  42  is formed by the recesses  22  and  21  as described above, preferably, the movable electrode  41  of the center switch S 1  and the movable electrodes  42  of the side switches S 2  have an arcuate section shape which upward swells, an outer peripheral edge of the movable electrode  41  of the center switch S 1  is seated on a bottom face of the recess  22  for positioning the movable electrode  41  of the center switch S 1 , outer peripheral edges of the movable electrodes  42  of the side switches S 2  are seated on bottom faces of the recesses  21  for positioning the movable electrode  42  of the side switches S 2 , respectively, and steps H are formed between the bottom face of the recess  22  for positioning the movable electrode  41  of the center switch S 1  and the bottom faces of the recesses  21  for positioning the movable electrode  42  of the side switches S 2 , respectively. According to this configuration, the outer peripheral edge of the movable electrode  41  of the center switch S 1  is placed with being separated in the thickness direction of the body from the outer peripheral edges of the movable electrodes  42  of the side switches S 2 . Therefore, the outer peripheral edge of the movable electrode  41  of the center switch S 1 , and the outer peripheral edges of the movable electrodes  42  of the side switches S 2  can be placed so as to overlap with each other in the thickness direction of the body  1 . 
     In the invention, it is possible to employ a configuration in which the bottom faces of the recesses  21  into which the movable electrodes  42  of the side switches S 2  are to be fitted, respectively are higher in level than the bottom face of the recess  22  into which the movable electrode  41  of the center switch S 1  is to be fitted. 
     In the invention, it is possible to employ a configuration in which a common terminal  33  is placed on the bottom face of the recess  22  into which the movable electrode  41  of the center switch S 1  is to be fitted, and the bottom faces of the recesses  21  into which the movable electrode  42  of the movable electrode  42  are to be fitted, respectively, so as to be electrically connected to each other, and the outer peripheral edge of the movable electrode  41  of the center switch S 1  and the outer peripheral edges of the movable electrodes  42  of the side switches S 2  are in contact with the common terminal  33 . According to this configuration, there arises no obstacle even when the movable electrode  41  of the center switch S 1  and the movable electrodes  42  of the side switches S 2  which are placed so as to overlap with each other are in contact with each other to be electrically connected. 
     In the invention, preferably, gaps U are formed between an upper face of the movable electrode  41  of the center switch S 1  and the outer peripheral edges of the movable electrodes  42  of the side switches S 2 , respectively, each of the gaps having an area which can absorb displacement of the outer peripheral edge of the movable electrode  42  of corresponding one of the side switches S 2  due to flexural deformation that is caused when the movable electrode  42  is pressed down by the operation member  7 . According to this configuration, even when the movable electrode  42  of the side switch S 2  is operated via the operation member  7  to be flexurally deformed, a situation in which the movable electrode  42  of the side switch S 2  interferes with the movable electrode  41  of the center switch S 1  to damage the movable electrodes  41  and  42  does not occur. 
     In the invention, it is possible to employ a configuration in which the side switches S 2  are placed in four positions at regular angular intervals around the single center switch S 1 , respectively, the movable electrode  41  of the center switch S 1  and the movable electrodes  42  of the side switches S 2  are configured by dome-like snap plates which have a circular shape in a plan view, and which have the same shape and size, respectively, the recesses  21  for positioning the movable electrodes  42  of the side switches S 2  are separated from one another by four partition walls  13  which form the recesses  21 , and a recess surrounded by inner end faces  14  of the partition walls  13  is formed as the recess  22  for positioning the movable electrode  41  of the center switch S 1 . According to this configuration, the one center switch S 1  and the four side switches S 2  are selectively used so that plural kinds (for example, five kinds) of signals can be input and output. 
     As descried above, according to the invention, while exerting the same inputting and outputting abilities as those of a multi-contact inputting device of the conventional art, miniaturization and compaction of the whole shape of the device can be easily realized. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a plan view showing the structure of the body of a multi-contact inputting device which is an embodiment of the invention; 
     FIG. 2 is a section view taken along the line II—II of FIG. 1; 
     FIG. 3 is a section view taken along the line III—III of FIG. 1; 
     FIG. 4 is a section view taken along the line IV—IV of FIG. 1; 
     FIG. 5 is an enlarged section view taken along the line V—V of FIG. 1; 
     FIG. 6 is a schematic plan view of a state where movable electrodes are placed in predetermined positions of the body  1  of FIG. 1; 
     FIG. 7 is a section view taken along the line VII—VII of FIG. 6; 
     FIG. 8 is a diagram exemplarily showing an arrangement pattern of stationary electrodes, a common terminal, and the like which are embedded into the body; 
     FIG. 9 is a section view of the multi-contact inputting device in the case where an operation member maintains a neutral posture; 
     FIG. 10 is a section view of the multi-contact inputting device in the case where the operation member is pressed down; and 
     FIG. 11 is a section view of the multi-contact inputting device in the case where the operation member is tilted. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     As shown in FIGS. 1 to  4 , a body  1  is configured by a flat synthetic resin molded piece which has a substantially square shape in a plan view. The body  1  comprises a peripheral wall  12  which forms the outer peripheral edge of the body  1 . The body  1  further comprises four partition walls  13  which inward protrude from four positions of the peripheral wall  12  and arranged at regular angular intervals, respectively. Four recesses  21  which are located at regular angular intervals are formed by the inner face of the peripheral wall  12 , and the both side faces of the four partition walls  13 . A single center recess  22  is formed in a portion surrounded by the inner end faces  14  of the four partition walls  13 . 
     As seen from FIG. 1, each of the four recesses  21  separated by the four partition walls  13  is a circular recess in which the inner face is formed as an arcuate face. Furthermore, the inner end faces  14  of the partition walls  13  forming the single center recess  22  are formed as arcuate faces the center of which coincide with one another. Therefore, also the recess  22  is a circular recess. The single center recess  22  communicates with the four surrounding recesses  21  through spaces between adjacent ones of the partition walls  13 . 
     In a region including the single center recess  22  and the four surrounding recesses  21  shown in FIG. 1, steps H shown in FIG. 5 are formed in boundary portions  23  between the substantially square region including the whole of the center recess  22  and the regions outsides the square region, respectively. Across each of the boundary portions  23 , the substantially square region including the whole of the center recess  22  is stepwise lower than the outer region. According to this configuration, bottom faces  21   a  of the four surrounding recesses  21  are located at a level which is higher by one step than a bottom face  22   a  of the center recess  22 . 
     As shown in FIGS. 1 to  4 , a stationary electrode  31  is placed on the bottom face  22   a  of the single center recess  22 . The face of the stationary electrode  31  is flush with the bottom face  22   a  of the center recess  22 . Stationary electrodes  32  are placed on the bottom faces  21   a  of the four surrounding recesses  21  which are located at a higher level than the bottom face  22   a  of the center recess  22 , respectively. The faces of the stationary electrodes  32  are flush with the bottom faces  21   a  of the recesses  21 . On the bottom face  22   a  of the center recess  22  and the bottom faces  21   a  of the four surrounding recesses  21 , a common terminal  33  which is formed by a single metal plate is placed with being electrically insulated from the stationary electrodes  31  and  32 . The upper face of the common terminal  33  is flush with the bottom faces  21   a  and  22   a.    
     As seen from FIG. 8, a soldering terminal  34  is formed continuously with the stationary electrode  31  which is placed in the center recess  22 . Soldering terminals  35  are formed continuously with the stationary electrodes  32  which are placed in the four surrounding recesses  21 , respectively. A soldering terminal  36  is formed continuously with the common terminal  33 . With respect to the soldering terminals  34 ,  35 , and  36 , sets each configured by three soldering terminals are distributed to the right and left sides of the body  1 , respectively, and laterally protrude therefrom. In the illustrated example, the soldering terminals  34 ,  35 , and  36  are of the surface mount type. Alternatively, the soldering terminals  34 ,  35 , and  36  may be formed as those of the pin type. 
     The center recess  22  and the four surrounding recesses  21  have the same diameter. As shown in FIGS. 6 and 7, movable electrodes  41  and  42  respectively configured by dome-like snap plates which have a circular shape in a plan view, and which have the same shape and size are fitted into the recesses  21  and  22 , respectively. Outer peripheral edges of the movable electrodes  41  and  42  are seated on the bottom faces  22   a  and  21   a  of the recesses  22  and  21  under the condition that the movable electrodes are in contact with the common terminal  33 . The movable electrode  41  which is fitted into the center recess  22  is formed by stacking two snap plates of the same size and shape. The movable electrodes  41  and  42  are slightly smaller in diameter than the recesses  22  and  21 . Therefore, the movable electrode  41  which is fitted into the center recess  22  can be flexurally deformed in the center recess  22  with accompanying a snap operation, and the movable electrodes  42  which are fitted into the four surrounding recesses  21  can be flexurally deformed in the recesses  21  with accompanying a snap operation, respectively. A part of each of the movable electrodes  42  which are fitted into the four surrounding recesses  21  is placed so as to, in the thickness direction of the body  1 , overlap with respective one of four portions of the outer periphery of the movable electrode  41  which is fitted into the center recess  22 . The stationary electrode  31  on the bottom face  22   a  of the center recess  22 , and the movable electrode  41  which is fitted into the recess  22  so as to cover the stationary electrode constitute the center switch S 1 . The stationary electrodes  32  on the bottom faces  21   a  of the four surrounding recesses  21 , and the movable electrodes  42  which are respectively fitted into the recesses  21  so as to cover the stationary electrodes  32  constitute the four side switches S 2 . 
     According to this configuration, with respect to the movable electrode  41  of the center switch S 1 , the movable electrodes  42  of the four side switches S 2  surrounding the center switch are placed so as to partly overlap in the thickness direction of the body  1 . When the center switch S 1  is placed in the center of the body  1  and the four side switches S 2  are placed with being distributed with respect to the center switch S 1  in diagonal directions of the body  1  as shown in, for example, FIG. 6, therefore, the diagonal length of the body  1  can be shortened by a length corresponding to the overlapping widths D between the movable electrode  41  of the center switch S 1  and the movable electrodes  42  of the two side switches S 2  which are placed in a diagonal direction of the body, as compared with the case where the movable electrode  41  are placed so as not overlap with two the movable electrodes  42 . Each of the movable electrodes  41  and  42  of the center switch S 1  and the four side switches S 2  is individually positioned by the respective one of the recesses  22  and  21  so as not to be positionally deviated. Consequently, the operation reliability of the opening and closing operations of the center switch S 1  and the side switches S 2  can be maintained to be excellent. 
     As shown in FIGS. 9 to  11 , the body  1  is covered with a cover  5  made of a metal. A guide ridge  51  having a ring like shape in which the diameter is gradually reduced as moving upward is disposed in the center of the cover  5 . A movable member  6  is held by the movable electrodes  42  and the cover  5  via the guide ridge  51  so as to be swingable in every direction. Pressing portions  61  which respectively correspond to the movable electrodes  42  of the four side switches S 2  are disposed on the rear face of the movable member. An operation member  7  is passed through a center hole  62  of the movable member  6  so as to be axially slidable. A flange  71  which is formed integrally with a lower end portion of the operation member  7  is opposed to the lower face  63  of the movable member  6 . A pressing portion  72  corresponding to the movable electrode  41  of the center switch S 1  is disposed on the lower face of the flange  71 . 
     In the thus configured multi-contact inputting device, when an external force such as that in a swinging direction or in the pressing direction is not applied to the operation member  7 , the pressing portion  72  of the operation member  7  is supported by the movable electrode  41  of the center switch S 1  as shown in FIG. 9, and the four pressing portions  61  of the movable member  6  are supported by the movable electrodes  42  of the four side switches S 2 , respectively. Therefore, the operation member  7  maintains a neutral posture in which the member stands upright. 
     When the closed or opened state of the center switch S 1  is to be switched over, the operation member  7  is pressed down as indicated by the arrow a of FIG.  10 . As a result, the operation member  7  is lowered with respect to the movable member  6 , and the pressing portion  72  of the operation member  7  presses down the movable electrode  41  of the center switch S 1  to cause the electrode to be flexurally deformed while performing a snap operation. As shown in the figure, therefore, the movable electrode  41  makes contact with the stationary electrode  31  to attain electrical conduction between the electrodes  41  and  31 , whereby the closed or opened state of the center switch S 1  is switched over. 
     When the closed or opened state of the predetermined one of the side switches S 2  is to be switched over, the operation member  7  is swung toward the side switch S 2  as indicated by the arrow b of FIG.  11 . As a result, the movable member  6  is pushed by the operation member  7  to be tilted, and the predetermined one of the pressing portions  61  of the movable member  6  presses down the movable electrode  42  of the predetermined side switch S 2  to cause the electrode to be flexurally deformed while performing a snap operation. As shown in the figure, therefore, the movable electrode  42  makes contact with the stationary electrode  32  to attain electrical conduction between the electrodes  42  and  32 , whereby the closed or opened state of the side switch S 2  is switched over. When the closed or opened state of another one of the side switches S 2  is to be switched over, similar operations are performed. 
     In the embodiment, the operation member  7  is axially slidable with respect to the movable member  6 . Therefore, the operation of pressing down the operation member  7  to switch over the closed or opened state of the center switch S 1 , and that of tilting the movable member  6  together with the operation member  7  to switch over the closed or opened state of the predetermined one of the side switches S 2  can be simultaneously performed. 
     In the embodiment, the closed or opened states of the center switch S 1  and the four side switches S 2  can be independently switched over by pressing or tilting the single operation member  7 . Alternatively, operation members may be respectively disposed for the center switch S 1  and the four side switches S 2 , and the closed or opened states of the center switch S 1  and the four side switches S 2  can be independently switched over by independently operating the operation members. Each of the movable electrodes  41  and  42  of the center switch S 1  and the side switches S 2  is formed by the circular dome-like snap plate which upward swells. The movable electrodes may be formed by snap plates of another shape (for example, rectangular) and having an arcuate section shape which upward swells. 
     In the embodiment, the common terminal  33  is formed as a common terminal which is in contact with both the movable electrode  41  of the center switch S 1  and the movable electrode  42  of the corresponding one of the four side switches S 2 . Even when the overlapping portions of the movable electrodes  41  and  42  of the switches S 1  and S 2  are in contact with each other, therefore, there arises no problem in the opening and closing operations of the switches. When the overlapping portions of the movable electrodes  41  and  42  are in contact with each other, however, there is a fear that the movable electrodes  41  and  42  may be damaged because, when the movable electrode  42  of one of the side switches S 2  is flexurally deformed, for example, the movable electrode  42  rubs against the movable electrode  41  of the center switch S 1 . In order to solve this problem, it is effective to form gaps U between the upper face of the movable electrode  41  of the center switch S 1  and the outer peripheral edges of the movable electrodes  42  of the side switches S 2 , respectively. In the case where such gaps U are formed, it desirable to form the gaps U so that, when each of the movable electrodes  42  of the side switches S 2  is pressed by the operation member  7  or the movable member  6  to be flexurally deformed, displacement of the outer peripheral edge of the movable electrode  42  is absorbed by the corresponding one of the gaps U. According to this configuration, when one of the movable electrodes  42  of the side switches S 2  is flexurally deformed, the outer peripheral edge of the movable electrode  42  is prevented from rubbing against the movable electrode  41  of the center switch S 1 . Therefore, a situation in which the movable electrodes  42  and  41  are damaged does not occur. In order to form the gaps U, it is effective to increase the level difference between the bottom face  22   a  of the center recess  22  and the bottom face  21   a  of each of the surrounding recesses  21 , i.e., the step H. 
     In the multi-contact inputting device of the embodiment, the steps H are formed between the bottom face  22   a  of the center recess  22  into which the movable electrode  41  of the center switch S 1  is fitted, and the bottom faces  21   a  of the recesses  21  into which the movable electrodes  42  of the side switches S 2  are fitted, so that the movable electrodes  41  and  42  are placed in an overlapping manner. In order to place the movable electrodes  41  and  42  in an overlapping manner, it is not always necessary to form the steps H. For example, the movable electrodes  41  and  42  may be positioned by using fixation means including an adhesive tape or the like so as to be placed in an overlapping manner. The movable electrodes  42  of the side switches S 2  are individually formed. Alternatively, two or all of the electrodes may be formed as an integral member. 
     The entire disclosure of Japanese Patent Application No. 2000-92065 filed on Mar. 29, 2000 including specification, claims, drawings and summary are incorporated herein by reference in its entirety.