Abstract:
A remote controller, which enables secure pressing operation of operational buttons, includes a top case ( 10 ) having a plurality of through holes ( 12 ) and a plurality of operational buttons ( 31 ) exposed respectively from the through holes of the top case, so that each of the operational buttons is pressed for controlling equipment. Ribs ( 13 ) protrude from the inner surface of the top case along circumferences of the through holes.

Description:
[0001]     This application is based on Japanese Patent Application No. 2006-252204 filed on Sep. 19, 2006, the contents of which are hereby incorporated by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a remote controller for remote control of various types of equipment.  
         [0004]     2. Description of Related Art  
         [0005]     There are various types of equipment that can be controlled by using a remote controller. In particular, general electric equipment that can be controlled by a remote controller includes a television set that receives broadcasting programs and displays them, a moving image recording and reproducing device that records moving image information (including sound information) such as a broadcasting program or the like on a recording medium and reads the recording information so that the moving image can be reproduced like an HDD (Hard Disk Drive) recorder, a DVD (Digital Versatile Disk) recorder or a video tape recorder, an audio visual device such as a stereo set that reproduces music and sounds, an air conditioner and the like. Control of the electric equipment by using the remote controller is performed when a user presses a desired operational button on the remote controller and then an instruction signal assigned to the operational button is transmitted from the remote controller.  
         [0006]     As shown in  FIGS. 5 and 6 , a conventional ordinary remote controller has a casing made up of a top case  110  and a bottom case  120 , in which an operational button body  130 , a circuit board  140 , a transmitter (not shown), a battery (not shown) and the like are disposed (see JP-A-H5-205559 and JP-A-2006-19880, for example). The circuit board  140  is supported in the state sandwiched between a lower column  121  protruding from the inner surface of the bottom case  120  and an upper column (not shown) protruding from the inner surface of the top case  110 . The bottom case  120  and the top case  110  are fastened to each other with screws.  
         [0007]     In addition, the operational button body  130  is made of an elastic material such as silicone rubber. It has integrally a plurality of operational buttons  131  arranged with a predetermined space and a base portion  132  disposed among the operational buttons  131  and connected to neighboring operational buttons  131 . This operational button body  130  is supported in the state where its base portion  132  is put on the circuit board  140  and pushed by a grid-like rib  111  protruding from the inner face of the top case  110  (see  FIG. 6 ) onto the circuit board  140 .  
         [0008]     The top case  110  is provided with through holes  112  formed at positions corresponding to the operational buttons  131 , and the operational buttons  131  are exposed from the through holes  112 . Each of the operational buttons  131  is floated from the circuit board  140  slightly, and switch contacts are disposed on the circuit board  140  directly below the operational buttons  131 .  
         [0009]     According to this structure, when the operational button  131  is pressed by a light force, a connection portion between the operational button  131  and the base portion  132  is deformed elastically as it is, and the operational button  131  contacts with the circuit board  140  so that the switch contact disposed there is made. In this case, if the operational button  131  is pressed by a strong force right down, the operational button  131  itself is further deformed elastically to compress as shown in  FIG. 7 . When the switch contact is made, an infrared signal of an instruction assigned to the switch contact is transmitted from the transmitter, so that the signal controls the target electric equipment. When the press operation of the operational button  131  is cancelled, the operational button  131  returns to its original position by its elastic restoring force (see  FIG. 5 ), so that the switch contact is broken.  
         [0010]     Although pressing operation by a light force or a strong force right down is expected naturally as the operation of the operational button  131 , some users may press it by a strong force in a slanting direction. In this case, a state of so-called button stuck may occur in the above mentioned conventional remote controller as shown in  FIG. 8 , in which the operational button  131  pressed by a strong force in a slanting direction enters lower than the through hole  112  so that a corner of its upper surface enters along the inner surface of the top case  110  locally. Even if the pressing operation is cancelled in this state, the corner of the upper surface of the pressed bottom is caught by the inner surface of the top case  110  so that the pressed state of the bottom remains. If such a button stuck state occurs, not only the stuck operational button  131  but also other operational buttons  131  cannot be operated because the switch contact of the stuck operational button remains in the connected state.  
       SUMMARY OF THE INVENTION  
       [0011]     The present invention is made in view of the above described problem and it is an object of the present invention to provide a remote controller in which pressing operation of its operational button can be performed securely.  
         [0012]     To attain the above described object, a remote controller according to a first aspect of the present invention includes a top case having a plurality of through holes, and a plurality of operational buttons exposed respectively from the through holes of the top case, so that each of the operational buttons is pressed for controlling the equipment, the remote controller is characterized by a structure in which ribs protrude from the inner surface of the top case along circumferences of the through holes.  
         [0013]     According to this structure, even if the operational button is pressed by a strong force in a slanting direction, the inner surface of the rib that extends from the through hole prevents the button from disengagement. Therefore, it can be avoided that a corner of the upper surface of the operational button enters along the inner surface of the top case. As a result, when pressing operation is canceled, button stuck does not occur.  
         [0014]     As to a remote controller according to a second aspect of the present invention, the equipment is a television set that receives and displays a broadcasting program in the remote controller of the above mentioned first aspect.  
         [0015]     A remote controller according to a third aspect of the present invention that is for remote control of a television set that receives and displays a broadcasting program, includes a top case having a plurality of through holes, and a plurality of operational buttons exposed respectively from the through holes of the top case, so that each of the operational buttons is pressed for controlling the television set, and the remote controller is characterized by a structure in which ribs protrude from the inner surface of the top case along circumferences of the through holes.  
         [0016]     According to this structure, even if the operational button is pressed by a strong force in a slanting direction, the inner surface of the rib that extends from the through hole prevents the button from disengagement. Therefore, it can be avoided that a corner of the upper surface of the operational button enters along the inner surface of the top case. As a result, when pressing operation is canceled, button stuck does not occur.  
         [0017]     According to the present invention, it is possible to provide a remote controller that can prevent button stuck so that pressing operation of operational buttons can be performed securely. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]      FIG. 1  is a cross sectional view to show a main portion of a remote controller according to an embodiment of the present invention.  
         [0019]      FIG. 2  is a perspective view of a top case of the remote controller shown in  FIG. 1  viewed from the inside.  
         [0020]      FIG. 3  is a cross sectional view to show an example of an operating state of the remote controller shown in  FIG. 1 .  
         [0021]      FIG. 4  is a cross sectional view to show an example of an operating state of the remote controller shown in  FIG. 1 .  
         [0022]      FIG. 5  is a cross sectional view to show a main portion of a conventional remote controller.  
         [0023]      FIG. 6  is a perspective view of a top case of the remote controller shown in  FIG. 5  viewed from the inside.  
         [0024]      FIG. 7  is a cross sectional view to show an example of an operating state of the remote controller shown in  FIG. 5 .  
         [0025]      FIG. 8  is a cross sectional view to show an example of an operating state of the remote controller shown in  FIG. 5 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0026]     Hereinafter, an embodiment of a remote controller according to the present invention will be described in detail with reference to the attached drawings.  FIG. 1  is a cross sectional view to show a main portion of an remote controller according to an embodiment of the present invention,  FIG. 2  is a perspective view of a top case of the remote controller viewed from the inside, and  FIG. 3  and  FIG. 4  are cross sectional views to show an example of an operating state of the remote controller.  FIG. 3  shows the state where an operational button is pressed by a strong force right down, while  FIG. 4  shows the state where the operational button is pressed by a strong force in a slanting direction.  
         [0027]     The remote controller of this embodiment is used for controlling a television set as an example of electric equipment. The television set has an essential function to receive moving image information (including sound information) of a broadcasting program of each channel and displaying the moving image for a user to watch.  
         [0028]     As shown in  FIG. 1  and  FIG. 2 , the remote controller has a casing made up of a top case  10  and a bottom case  20 , in which an operational button body  30 , a circuit board  40 , a transmitter (not shown), a battery (not shown) and the like are disposed. The top case  10  and the bottom case  20  of this embodiment are molded of a synthetic resin such as polystylene or acrylonitrile-butadiene copolymer. The circuit board  40  is supported in the state sandwiched between a lower column  21  protruding from the inner surface of the bottom case  20  and an upper column (not shown) protruding from the inner surface of the top case  10 . The bottom case  20  and the top case  10  are fastened to each other with screws.  
         [0029]     In addition, the operational button body  30  is made of an elastic material such as silicone rubber. It has integrally a plurality of operational buttons  31  arranged with a predetermined space and a base portion  32  disposed among the operational buttons  31  and connected to neighboring operational buttons  31 . The operational button  31  has a cylindrical shape or a square pole shape. This operational button body  30  is supported in the state where its base portion  32  is put on the circuit board  40  and pushed by a grid-like rib  11  protruding from the inner face of the top case  10  (see  FIG. 2 ) onto the circuit board  40 .  
         [0030]     The top case  10  is provided with through holes  12  formed at positions corresponding to the operational buttons  31  to have shapes corresponding to the operational buttons  31 , and the operational buttons  31  are exposed from the through holes  12 . Each of the operational buttons  31  is floated from the circuit board  40  slightly, and switch contacts are disposed on the circuit board  40  directly below the operational buttons  31 . The switch contacts corresponding to operational buttons  31  are assigned to power on/off of the television set, channel numbers, channel up, channel down, volume up, volume down, input selection and the like, individually. A microcomputer that controls entire operation of the remote controller, a memory and the like are mounted on the circuit board  40 .  
         [0031]     In this embodiment of the present invention, a rib  13  protrudes from the inner surface of the top case  10  along circumference of each of the through holes  12 . Therefore, each of the operational buttons  31  is surrounded by the inner surface of the through hole  12  as well as the inner surface of the rib  13 .  
         [0032]     When the operational button  31  is pressed by a light force in this structure, a connection portion between the operational button  31  and base portion  32  is deformed elastically as it is, and the operational button  31  contacts with the circuit board  40  so that the switch contact disposed there is made. In this case, if the operational button  31  is pressed by a strong force right down, the operational button  31  itself is further deformed elastically to compress as shown in  FIG. 3 . When the switch contact is made, an infrared signal of an instruction assigned to the switch contact is transmitted from the transmitter, so that the signal controls the target electric equipment. When the press operation of the operational button  31  is cancelled, the operational button  31  returns to its original position by its elastic restoring force (see  FIG. 1 ), so that the switch contact is broken.  
         [0033]     In addition, if the operational button  31  is pressed by a strong force in a slanting direction, the operational button  31  contacts with the circuit board  40  to make the switch contact, and in addition, the operational button  31  itself is deformed elastically to compress and a corner of the upper surface of the operational button  31  enters inward from the through hole  12  locally as shown in  FIG. 4 . However, since there is the rib  13  continuing the through hole  12 , the operational button  31  abuts the inner surface of the rib  13  and does not enter along the inner surface of the top case  10 . Therefore, if the pressing operation is cancelled in this state, a button stuck state does not occur, and the operational button  31  returns to its original position so that the switch contact is broken. In this way, according to the remote controller of the present invention, the button stuck can be prevented, so that pressing operation of the operational button  31  can be performed securely. In addition, since the elastic deformation of the operational button  31  itself is restricted by abutting with the inner surface of the rib  13 , deformation quantity of the operational button  31  is controlled virtually to be small. As a result, improvement of life of the operational button  31  can be expected.  
         [0034]     Note that the protruding height of the rib  13  from the inner surface of the top case  10  is the extent that the upper surface of the operational button  31  does not become lower than the lower edge of the rib  13  even if the operational button  31  is pressed by a strong force in a slanting direction.  
         [0035]     The present invention is not limited to the embodiment described above, which can be modified variously in the scope of the present invention without deviating from the spirit thereof. For example, the electric equipment as a target of remote control is not limited to the television set but can be a moving image recording and reproducing device such as an HDD recorder, DVD recorder or a video tape recorder. The present invention can also be applied to other audio visual device such as a stereo set. In addition, the present invention can be applied generally to any equipment that can be controlled by a remote controller without limiting to electric equipment.  
         [0036]     The present invention is useful to a remote controller for remote control of various types of equipment.