Abstract:
The operating member is constructed by supporting the button members with the thin sheet member without integrally constructing the button members, and therefore, the device can be downsized and slimmed. The key tops of the button members can be individually surface-treated before assembly, and therefore, a user can easily recognize the kinds of buttons at the time of operation, and an operation mistake can be prevented.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an operating member, and particularly relates to an operating member which performs operation input by pressing a button. 
     2. Description of the Related Art 
     Conventionally, a panel switch with a plurality of buttons integrally constructed by a hinge portion to be mounted to a case having a button opening is proposed (for example, Japanese Utility Model Application Laid-open No. 5-33428). 
     However, since a plurality of buttons are integrally constructed in the panel switch as described above, in order to perform surface treatment (for example, plating, coating, polishing) individually for each button, it is necessary to apply masking to the other portions than the buttons for which the surface treatment is performed, and therefore, the treatment becomes troublesome. The buttons are sometimes placed at the positions separated from each other for design of the apparatuses and enhancement in operability. In this case, if each of the buttons is integrally constructed, there is the problem that the component such as the hinge portion increases in size and cost of the material increases. Further, the hinge portion requires enough strength to hold a plurality of buttons, and therefore, there is the problem that slimming is difficult. 
     SUMMARY OF THE INVENTION 
     The present invention is made in view of the above circumstances, and has an object to provide an operating member which makes it possible to work buttons individually, and makes it possible to reduce cost and thickness of components. 
     In order to achieve the above-described object, a first aspect of the present invention provides an operating member comprising: a button member having a key top and a key stem, an apparatus casing having a button opening from which the key top is exposed, a sheet member which is formed of a material having elasticity, has a key stem opening through which the key stem is penetrated, and holds the button member by pressing the button member to the button opening, and a base board on which a switch which constructs a transmission path of a signal when the key top is pressed and the switch is pressed by the key stem is placed. 
     The operating member according to the first aspect is constructed by supporting the button member with the thin sheet member without integrally constructing button members, and therefore, the device can be downsized and slimmed. 
     The operating member according to a second aspect is, in the first aspect, characterized in that the sheet member is formed of any one of polyester, polycarbonate and vinyl chloride. The second aspect limits the material of which the sheet member is formed. 
     The operating member according to a third aspect is, in the first or the second aspect, characterized in that at least one of coating, plating, polishing, and embossing is applied to a surface of the key top of the button member. 
     According to the operating member of the third aspect, surface treatment is individually applied to the key top of the button member, and therefore, the user easily recognizes the kind of button, and an operation mistake can be prevented. 
     The operating member according to a fourth aspect is, in any one of the first to the third aspects, characterized in that shapes of the key stem and the key stem opening are paired. 
     According to the operating member of the fourth aspect, the button member can be prevented from being mistakenly disposed at the time of assembly. 
     The operating member according to a fifth aspect is, in the first to the fourth aspects, characterized in that the sheet member has electrical conductivity, and when the sheet member is charged with static electricity, the sheet member discharges the static electricity to an outside. 
     According to the operating member of the fifth aspect, the static electricity which occurs by friction or the like at the time of pressing the button member can be discharged, and malfunction of the circuit of the apparatus can be prevented. 
     The operating member according to a sixth aspect is, in the first to the fifth aspects, characterized by further comprising a sheet support member which presses the sheet member against the apparatus casing. 
     According to the operating member of the sixth aspect, the sheet member is reliably pressed against the apparatus casing, and therefore, malfunction of the apparatus which is caused by the sheet member sagging to bring the button member into contact with the switch can be prevented. 
     The operating member according to a seventh aspect is, in the first to the sixth aspects, characterized in that the sheet support member is a bent part which is bent to a side of the base board on which the switch is placed by cutting a part of the sheet member, and that the bent part is biased to the apparatus casing side by the base board. The seventh aspect limits the sheet support member of the sixth aspect. 
     According to the present invention, the operating member is constructed by supporting the button members with the thin sheet member without integrally constructing the button members, and therefore, the device can be downsized and slimmed. According to the present invention, the key tops of the button members can be individually surface-treated before assembly, and therefore, a user can easily recognize the kinds of buttons at the time of operation, and an operation mistake can be prevented. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded perspective view showing an operating member according to an embodiment of the present invention; 
         FIG. 2  is an enlarged sectional view of a part of an operating member  10 ; 
         FIG. 3  is a sectional view schematically showing an operating method of the operating member  10 ; 
         FIG. 4  is a plane view showing an example of a shape of a key stem opening; 
         FIGS. 5A to 5E  are perspective views showing an example of a shape of the key stem; 
         FIG. 6  is a perspective view showing a support structure of a sheet member  16 ; 
         FIG. 7  is a sectional view taken along the line  7  to  7  in  FIG. 6 ; 
         FIG. 8  is a sectional view showing another embodiment of a fixing method of the sheet member  16 ; 
         FIG. 9  is a plane view showing a cross button; 
         FIG. 10  is a plane view showing a key stem opening for the cross button; 
         FIG. 11  is a sectional view of the cross button; and 
         FIG. 12  is a plane view showing another embodiment of a shape of the key stem opening for the cross button. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Preferred embodiments of an operating member according to the present invention will be described with reference to the attached drawings. The operating member of the present invention can be applied to apparatuses having operation buttons such as digital cameras, key boards, and video/audio apparatuses. 
       FIG. 1  is an exploded perspective view showing an operating member according to a first embodiment of the present invention. As shown in  FIG. 1 , an operating member  10  of the first embodiment includes button members  12 A to  12 E, an apparatus casing  14 , a seat member  16  and a base board  18 . 
     The button members  12 A to  12 E are formed of, for example, metal and a resin such as plastic, and are constructed by key tops  22  of which front surfaces are fitted into the apparatus casing  14  and exposed to an outside from button openings  26 A to  26 E, and key stems  24  which are fitted into the sheet member  16 . Plating treatment is applied to the front surfaces of the key tops  22  of the button members  12 A and  12 B. Embossing treatment is applied to a top surface of the key top  22  of the button member  12 C, and coating is applied to top surfaces of the key tops  22  of the button members  12 D and  12 E. 
     The apparatus casing  14  is an outer case of the apparatus to which the operation member  10  of the first embodiment is applied, and is provided with the button openings ( 26 A to  26 E respectively) in which the key tops  22  of the button members  12 A to  12 E are fitted. 
     The sheet member  16  is formed of a high polymer material such as polyester, polycarbonate or vinyl chloride, for example, and has elasticity. The thickness of the sheet member  16  is about 0.1 mm. The sheet member  16  is provided with key stem openings ( 28 A to  28 E respectively) at positions overlapping the button openings  26 A to  26 E when the sheet member  16  is overlaid on the apparatus casing  14 . 
     On the base board  18 , a circuit of the apparatus is formed, and switches (SWA to SWE respectively) are placed at positions which are overlaid on the button openings  26 A to  26 E and the key stem openings  28 A to  28 E when the base board  18  is overlaid on the apparatus casing  14  and the sheet member  16 . 
     Note that in the following description, the button members  12 A to  12 E, the button openings  26 A to  26 E, the key stem openings  28 A to  28 E and the switches SWA to SWE are described by properly removing the subscripts A to E from them. 
       FIG. 2  is an enlarged sectional view showing a part of the operating member  10 . The key tops  22  of the button members  12  are respectively fitted into the button openings  26  of the apparatus casing  14 , and the key stems  24  are respectively fitted into the key stem openings  28  of the sheet member  16 . The sheet member  16  is bonded to an inner surface of the apparatus casing  14  by an adhesive, and is fixed to the apparatus casing  14  by a screw  30 . Thereby, the button member  12  is sandwiched and fixed by the inside surface of the apparatus casing  14  and the sheet member  16 . 
       FIG. 3  is a sectional view schematically showing an operating method of the operating member  10 . When the key top  22  of the button member  12  is pressed by the finger of a user as shown in  FIG. 3 , the sheet member  16  is bent and the button member  12  is pressed down. Then, the switch SW on the base board  18  is pressed by the key stem  24 , and a contact point not shown in the switch SW is brought into electrical conduction to perform switching. When the finger of the user is released from the key top  22 , the button member  12  is pushed up to the position in  FIG. 2  by the elasticity of the sheet member  16 . Thereby, electric conduction of the contact point in the switch SW is ceased. 
     According to the first embodiment, the button member  12  is held by the thin sheet member  16 , and therefore, the components which construct the operating member  10  can be downsized and slimmed. Surface treatment (for example, plating, coating, polishing, vapor deposition, ion plating, embossing) can be easily applied individually to the key tops  22  of the button members  12  before assembly of the operating member  10 , and therefore, discrimination of the button members  12  can be facilitated. 
     Next, the shapes of the key stems  24  and the key stem openings  28  will be described with reference to  FIGS. 4 and 5 .  FIG. 4  is a plane view showing examples of the shapes of the key stem openings. As shown in  FIG. 4 , the sheet member  16  of the first embodiment is provided with five key stem openings  28 A to  28 E, and their shapes differ from each other. 
       FIGS. 5A to 5E  are perspective views showing the examples of the shapes of the key stems. The key stems  24 A to  24 E shown in  FIGS. 5A to 5E  are respectively fitted into the key stem openings  28 A to  28 E shown in  FIG. 4 . As described above, by forming the key stems  24  and the key stem openings  28  into paired shapes respectively, the button members  12  can be prevented from being mistakenly disposed when the operating member  10  is assembled. 
     Next, a support structure of the sheet member  16  will be described with reference to  FIGS. 6 and 7 .  FIG. 6  is a perspective view showing the support structure of the sheet member  16 , and  FIG. 7  is a sectional view taken along the line  7  to  7  in  FIG. 6 . As shown in  FIG. 6 , cutting is performed for a part of the sheet member  16 , and the part of the sheet member  16  is worked to have the structure bent to the base board  18  side. A bent portion  40  is biased (pressed) to the apparatus casing  14  side by the base board  18 . Thereby, the sheet member  16  can be prevented from sagging and separating from the apparatus casing  14  to bring the button member  12  into contact with the switch SW to cause malfunction of the apparatus. 
     In the first embodiment, the sheet member  16  is supported by applying cutting to a part of the sheet member  16 , but the sheet member  16  may be biased by sticking a plate spring to the sheet member  16 , or mounting a spring between the sheet member  16  and the base board  18 , for example. 
     The sheet member  16  has metal particles of iron, silver, copper lead or the like mixed therein and has electrical conductivity. Thereby, static electricity which occurs by a pressing operation for the button member  12  of the like is discharged to an outside via the apparatus casing  14 . 
     In the first embodiment, a layer in which the metal particles are mixed, or a layer of wiring or the like having elasticity may be provided on the surface of the sheet member  16 . The sheet member  16  may be electrically connected to a ground (GND) of the circuit on the base board  18 . 
     Next, another embodiment of a method for fixing the sheet member  16  to the apparatus casing  14  will be described.  FIG. 8  is a sectional view showing a second embodiment of the method for fixing the sheet member  16 . In the following explanation, the same constructions as the above described first embodiment such as the button members  12  and the like are given the same reference numerals and characters and the explanation of them will be omitted. In the example shown in  FIG. 8 , the surface on which the operating member  10  of the apparatus is placed has the structure in which an outer member  50  and an inner cabinet  52  are overlaid on each other, and the sheet member  16  is fixed by being sandwiched between the outer member  50  and the inner cabinet  52 . The base board  18  is fixed to the inner cabinet  52  with a screw or the like not shown. 
     According to the second embodiment, the sheet member  16  can be reliably held by being sandwiched between the outer member  50  and the inner cabinet  52 , and therefore, the button member  12  can be more reliably mounted. 
     Next, an example in which the operating member of the present invention is applied to a cross button will be described with reference to  FIGS. 9 to 12 .  FIG. 9  is a plane view showing the cross button,  FIG. 10  is a plane view showing a key stem opening for the cross button, and  FIG. 11  is a sectional view of the cross button. 
     A cross button  60  shown in  FIG. 9  is constructed by a center button  60 A and a cursor button  60 B. The cursor button  60 B is a multi-functional operating part capable of inputting instructions of four directions, that are left, right, up and down, and functions as an operation button which instructs selection of menu items. The center button  60 A is used at the time of entering the content selected by the cursor button  60 B, instructing execution (ensuring) of the processing and the like. Four key stems are formed at the cursor button  60 B corresponding to the direction marks  61  which show input directions. 
     As shown in  FIG. 10 , a key stem opening  62 A in which a key stem of the center button  60 A is fitted, and key stem openings  62 U,  62 B,  62 L and  62 R in which the four key stems of the cursor button  60 B are fitted are formed in the sheet member  16 . As shown in  FIG. 11 , switches SWU, SWB, SWL and SWR are placed on the base board  18  corresponding to the key stem openings  62 U,  62 B,  62 L and  62 R. When the center button  60 A is pressed by a user, the center button  60 A is pushed down, and the switch SWA is pressured. When each portion of the cursor button  60 B is pressed, the pressed portion is pushed down and the switch SWU, SWB, SWL or SWR is pressed. Thereby, the components of the cross button  60  can be downsized and slimmed. 
       FIG. 12  is a plane view showing another example of the shape of the key stem opening for the cross button. In the example shown in  FIG. 12 , a key stem opening  62 B for the cursor button  60 B is formed into a C-shape, and a region in a center where the key stem opening  62 A is formed is supported by a support portion  64 . 
     In the cross button  60 , the mode in which the sheet member  16  is given electrical conductivity and is caused to discharge static electricity, and the structure in which the casing of the apparatus is outer member and the inner cabinet which are overlaid on each other as in the example in  FIG. 8  can be applied.