Abstract:
A composite switch utilizing a single button to perform two or more switching functions including a rotational direction switch operation and a push-button switch operation. Rotational movement of the button elastically deforms a first contact spring by a rotation of a cam fixed to the button via a button shaft so as to connect the contact spring to a first electrode. Axial movement (push-button operation) elastically deforms a second contact spring provided at a lower end portion of the button shaft in response to a pressing down operation of the button so as to connect the second contact spring to a second electrode. A rotational direction returning spring and a pressing down direction returning spring are provided in an inner portion of the button for biasing the button in a neutral position and automatically returning the button to the neutral position. A waterproof packing is slidably disposed between the button shaft and a case in which the switches and button shaft are disposed. To avoid erroneous operation of the switch function, the switch is configured so that a pressing down operation of the button can not be performed while a rotating operation of the button is being performed.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a composite switch for an electronic apparatus having a plurality of switch functions in one switch mechanism. 
     2. Description of the prior Art 
     In a conventional switch, in order to obtain a plurality of switch functions, a rotational direction switch and a pressing down direction switch are separately and independently provided, respectively. 
     For example, at the time of an input operation for inputting information in a portable information apparatus, in order to select letters and symbols to be input and corrected, the number of switches for moving a cursor must be at least three switches comprising two switches for searching forward and searching rearward and, a switch for determining a letter and, or a symbol to be input and corrected, so that it is necessary to frequently switch fingers at each time of operation. Further, the frequency is of this increased as the amount of information to be input and corrected is increased. 
     In the structure of the conventional switch, since the moving direction of the switch is different between the rotational direction and the pressing down direction, it is unavoidable that separate switches for each independently exist. Accordingly, it is troublesome to switch the fingers and it is complex to operate the button. Further, there is the problem that a restriction in the design of a product is increased due to the need to include a plurality of buttons. 
     SUMMARY OF THE INVENTION 
     In order to solve the problems mentioned above, in accordance with a switch mechanism of the present invention, a switch provided which is structured such that a switch operation in a rotational direction is obtained by elastically deforming a contact spring by a cam fixed in such a manner as to follow to a button shaft so as to connect the contact spring to an electrode. Further, the switch is structured such that a switch operation in a pressing down direction is obtained by elastically deforming a contact spring provided at a lower end portion of the button shaft by pressing down the button so as to connect the contact spring to the electrode. Still further, the switch is structured such that a rotational direction returning spring and a pressing down direction returning spring are provided in an inner portion of the button, thereby automatically returning the button to a predetermined position. 
     Further, the switch is structured such that a waterproof packing is provided in a sliding portion between the button shaft and a case corresponding to a holding member of the button (hereinafter, refer red to as a case), thereby providing a water proof performance. 
     Still further, in order to avoid an erroneous operation of the switch function, the switch is structured such that the pressing down of the button can not be performed at a time of the rotating operation of the button. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A preferred form of the present invention is illustrated in the accompanying drawings in which: 
     FIG. 1 is a cross sectional view of a normal state of a composite switch for an electronic apparatus; 
     FIG. 2 is a cross sectional view which shows a state of pressing down the composite switch for the electronic apparatus; 
     FIG. 3 is a cross sectional view as seen from a line  3 - 3 ′ in FIG. 1 which shows the normal state of the composite switch for the electronic apparatus; 
     FIG. 4 is a cross sectional view as seen from a line  4 - 4 ′ in FIG. 1 which shows the normal state of the cam portion in the composite switch for the electronic apparatus; 
     FIG. 5 is a cross sectional view as seen from a line  3 - 3 ′ in FIG. 1 which shows a state at a time of a rotating operation of the composite switch for the electronic apparatus; 
     FIG. 6 is a cross sectional view as seen from a line  4 - 4 ′ in FIG. 1 which shows a state of the cam portion at a time of the rotating operation of the composite switch for the electronic apparatus; 
     FIG. 7A is a cross sectional view as seen from a line  7 - 7 ′ in FIG. 1 which shows the normal state of the composite switch for the electronic apparatus; and 
     FIG. 7B is a cross sectional view as seen from a line  7 - 7 ′ in FIG. 1 at a time of the rotating operation of the composite switch for the electronic apparatus. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The invention is structured such that a button ( 2 ) rotating or vertically moving in accordance with a movement of a user&#39;s finger is provided in an upper portion of one button shaft ( 3 ), a rotation returning spring ( 5 ) and a pressing down returning spring ( 7 ) are provided in an inner portion of the button ( 2 ), and a waterproof packing ( 4 ) is provided in a sliding portion between the button shaft ( 3 ) and a case ( 1 ). The switch is structured such that a cam ( 8 ) is fixed to a lower end portion of the button shaft ( 3 ) and an upper surface of the cam ( 8 ) is brought into contact with an inner surface of the case ( 1 ) so as to receive a spring force of the pressing down returning spring ( 7 ). Rotational direction contact springs ( 10 ,  10 ) and rotating switch electrodes ( 12 ,  13 ) are provided in an outer side of the cam ( 8 ), whereby the rotational direction contact springs ( 10 ,  10 ) are elastically deformed due to a rotation of the cam ( 8 ) in accordance with the rotation of the button shaft ( 3 ) so as to be connected to the rotating switch electrodes ( 12 ,  13 ), and a pressing down direction contact spring ( 11 ) elastically deforming due to a vertical motion of the button shaft ( 3 ) and the pressing down switch electrode. ( 14 ) are provided in a lower end portion of the button shaft ( 3 ). 
     Further, the structure is provided such that at a time of rotating the button, a lower surface ( 2   a   1 ) of an outer wall ( 2   a ) of the button comes close to an upper surface ( 15   a ) of a button receiving table ( 15 ) provided in the case ( 1 ) so as to be layered in a plane manner to prevent a pressing down operation of the button during a rotational movement thereof. 
     An embodiment will be described below with reference to the accompanying drawings. In FIG. 1, a rotation returning spring ( 5 ) is mounted to an inner portion of a button ( 2 ). A groove ( 21 )capable of receiving the rotation returning spring ( 5 ) at this time is defined in the inner portion of the button ( 2 ) by a button outer wall ( 2   a ), a button inner wall ( 2   b ) and a button top wall ( 2   c ). The rotation returning spring ( 5 ) is mounted to the groove ( 21 ) using the button shaft ( 3 ) as a guide, and a seat ( 6 ) is brought into contact with the lower surface of the button inner wall ( 2   b ) using the button shaft ( 3 ) as a guide within the groove ( 21 ), thereby pressing as a receiving member for the rotation returning spring ( 5 ). 
     Next, after setting the pressing down returning spring ( 7 ) using the button shaft ( 3 ) as a guide, the pressing down returning spring ( 7 ) is inserted to a recess portion ( 31 ) of the case ( 1 ). At this time, the pressing down returning spring ( 7 ) is held between the receiving surface ( 1   a ) of the pressing down returning spring ( 7 ) of the case ( 1 ) and the seat ( 6 ) with a spring characteristic in an axial direction. 
     The upper surface of the cam ( 8 ) fixed to the lower end portion of the button shaft ( 3 ) is brought into contact with the inner surface of the case ( 1 ) and receives a reaction force of the pressing down returning spring ( 7 ), thereby securing a normal position of the button ( 2 ). A water proof packing ( 4 ) is previously assembled at a predetermined position in the button shaft ( 3 ). The water proof packing ( 4 ) elastically deforms with respect to an inner wall ( 1   b ) of a through hole ( 41 ) of the case ( 1 ) so as to become slidable, thereby securing a water proof performance. 
     FIG. 4 is a cross sectional view as seen from  4 - 4 ′ in FIG. 1 showing a normal state of a cam portion in the composite switch for the electronic apparatus. 
     As shown in FIG. 4, a cam ( 8 ) formed in an oval shape is eccentrically inserted and fixed to a front end portion of the button shaft ( 3 ) inserted after passing through the case ( 1 ). That is, a notch ( 3   a ) is provided in an insertion portion of the cam ( 8 ) at the front end of the button shaft ( 3 ) as shown in FIG. 4 and a rectangular hole ( 8   a ) of the cam is engaged therewith in correspondence to a shape of the notch ( 3   a ), whereby the cam ( 8 ) follows a rotational motion of the button shaft ( 3 ) and can be rotated. After inserting the cam ( 8 ) to the front end portion of the button shaft ( 3 ), the cam ( 8 ) is fixed by an E ring ( 9 ) near the front end of the button shaft ( 3 ), as shown in FIG.  1 . 
     As shown in FIGS. 1 and 4, rotational direction contact springs ( 10 ,  10 ) supporting both ends to the module ( 50 ) of the electronic apparatus and mounted as a both end supporting beam are arranged at both sides of the cam ( 8 ) in an inner portion of the case ( 1 ), and a pair of rightward rotation switching electrodes ( 12 ) mounted on a wall surface of the module ( 50 ) and a pair of leftward rotation switching electrodes ( 13 ) are arranged at an outer side thereof. Further, as shown in FIG. 1, the pressing down direction contact springs ( 11 ) respectively mounted to the module ( 50 ) are arranged in a lower portion of the front end ( 3   a ) of the button shaft ( 3 ) positioned below the cam ( 8 ), and a pair of pressing down switching electrodes ( 14 ) are arranged in a further lower portion. 
     In this case, the pressing down direction contact spring ( 11 ) is formed by an insulative elastic rubber, and a conductive sheet ( 11   a ) opposing to the pressing down switch electrode ( 14 ) is provided on the lower surface. 
     FIG. 2 is a cross sectional view at a time of a pressing down operation of the button ( 2 ). When pressing down an upper surface ( 2   e ) of the button ( 2 ) by the user&#39;s fingers, the pressed down button shaft ( 3 ) elastically deforms and presses down the pressing down direction contact spring ( 11 ) placed below the lower portion of the cam ( 8 ), and further connects a pair of pressing down switch electrodes ( 14 ) arranged in the lower portion to the conductive sheet ( 11   a ), so that the switch is turned on. 
     Thereafter, when releasing the fingers from the button ( 2 ), the button ( 2 ) is automatically returned to an original position shown in FIG. 1 due to a restoring or biasing force of the pressing down returning spring ( 7 ) compressed by the pressing down operation. 
     Further, the pressing down direction contact spring ( 11 ) is also returned to an original position shown in FIG. 1 due to an elastic restoring force of the pressing down direction contact spring ( 11 ) itself. 
     A receiving state of the rotation returning spring ( 5 ) mounted to the inner portion of the button ( 2 ) is shown in FIGS. 1 and 3. 
     At this time, both ends ( 5   a ) of the rotation returning spring ( 5 ) receive a releasing force of the spring on a spring locking surface ( 2   d ) of the button ( 2 ) and are received in a groove ( 21 ) of the button ( 2 ), and front ends of the both ends ( 5   a ) of the rotation returning spring ( 5 ) are arranged and assembled within a space portion ( 61 ) of the case ( 1 ). 
     In a series of operations, the rotation returning spring ( 5 ) is pressed in an upward direction of the inner portion of the button ( 2 ) due to a press insertion of the seat ( 6 ) and follows a vertical motion of the button ( 2 ). 
     FIG. 3 is a cross sectional view as seen from a line  3 - 3 ′ in FIG. 1 in a normal state of the button ( 2 ), and shows a neutral position of the button ( 2 ). 
     FIG. 5 is a cross sectional view as seen from a line  3 - 3 ′ in FIG. 1 which shows a state of the rotation returning spring ( 5 ) disposed in the inner portion of the button ( 2 ) at a time of a rightward rotating operation of the button ( 2 ). When the button ( 2 ) rotates in a rightward direction from the position shown in FIG. 3 showing a neutral position, an end portion ( 5   a ) of the rotation returning spring ( 5 ) is locked with the spring lock surface ( 1   d ) of the case ( 1 ), and the other end portion ( 5   a ) of the rotation returning spring ( 5 ) receives a rotational force from the spring lock surface ( 2   d ) of the button ( 2 ) and rotates to a predetermined position. 
     At this time, the cam ( 8 ) rotates in a rightward direction from a neutral position shown in FIG. 4 so as to be in a state shown in FIG. 6, and a part ( 8   a ) of the outer shape of the cam ( 8 ) is pressed to the rotational direction contact spring ( 10 ). 
     FIG. 6 is a cross sectional view of the cam ( 8 ) portion as seen from a line  4 - 4 ′ in FIG. 1 when the button ( 2 ) is rotated in a rightward direction. That is, generally explaining, the button shaft ( 3 ) rotated in an optional direction by the rotating operation of the fingers rotates the cam ( 8 ) placed in such a manner as to follow to the rotation of the button shaft ( 3 ), elastically deforms the rotational direction contact spring ( 10 ) arranged in both sides of the cam ( 8 ) so as to press down, and further the rotational direction contact spring ( 10 ) is connected to a pair of rightward rotation switching electrodes ( 12 ) arranged in the outer side thereof or a pair of leftward rotation switching electrodes ( 13 ), so that the switch is turned on. 
     Thereafter, when releasing the fingers from the button ( 2 ), the button ( 2 ) is automatically returned to the neutral position shown in FIG. 3 due to a reaction force of the rotation returning spring ( 5 ) deformed by the spring lock surface ( 2   d ) disposed in the inner portion of the button and the spring lock surface ( 1   d ) of the case by the rotating operation. 
     Further, the rotational direction contact spring ( 10 ) is returned to the original position shown in FIG. 3 due to an elastic restoring force of the rotational direction contact spring ( 10 ) itself. 
     A description will be given of a structure for preventing an erroneous operation in the switch function at a time of the rotating operation of the composite switch for the electronic apparatus with reference to FIGS. 7A and 7B. 
     FIG. 7A is a cross sectional view as seen from a line  7 - 7 ′ in FIG. 1 which shows a normal state of the composite switch for the electronic apparatus. 
     FIG. 7B is a cross sectional view as seen from a line  7 - 4 ′ in FIG. 1 at a time of a rotating operation of the composite switch for the electronic apparatus. 
     The structure is made such that at a time of the rotating operation of the button ( 2 ), a lower surface ( 2   a   1 ) of an outer wall ( 2   a ) of the button comes close to an upper surface ( 15   a ) of a button receiving table ( 15 ) provided in the case ( 1 ) so as to be layered in a plane manner, and so as not to be layered in a plane manner in the normal state of the button ( 2 ). 
     In the structure described above, the switch is made such that even when a pressing down force is accidentally applied at a time of the rotating operation of the button ( 2 ), the lower surface ( 2   a   1 ) of the outer wall ( 2   a ) of the button ( 2 ) is brought into contact with an upper surface ( 15   a ) of the button receiving table ( 15 ). 
     The invention is embodied an aspect described above, and the following effects can be obtained. 
     Since the apparatus is made compact and a waterproof structure can be realized by providing the rotation returning spring ( 5 ), the seat ( 6 ), the button ( 2 ) for receiving the pressing down returning spring ( 7 ), the waterproof packing ( 4 ) and the cam ( 8 ) on the axis of one button shaft ( 3 ), a product design is not limited and a compact and advantageous design can be performed. 
     Further, since the structure is made such that it is impossible to press down the button at a time of the rotating operation of the button and the rotating operation and the pressing down operation can be performed by one button, an erroneous operation of the switch function is prevented and it is unnecessary to replace the fingers, so that an operation can be easily and securely performed. 
     Since the button ( 2 ) is always automatically returned to the neutral position by the rotation returning spring ( 5 ) and the button ( 2 ) is always automatically returned to the predetermined position by the pressing down returning spring ( 7 ), the operation of the button can be easily performed.