Patent Publication Number: US-8531407-B2

Title: Input apparatus

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention mainly relates to an input apparatus used for the operation of various electronic devices in an automobile. 
     2. Background Art 
     In recent years, many drivers of an automobile uses his or her fingers to operate an input apparatus such as a switch attached in the vicinity of a steering wheel, while still holding the steering wheel, to operate an electronic device such as an audio device or an air conditioner. In order to realize the application as described above, an input apparatus is preferred that is free from an operational error and that can be operated easily. 
     The conventional input apparatus as described above will be described with reference to  FIG. 8  and  FIG. 9 . 
       FIG. 8  is a cross-sectional view illustrating a conventional input apparatus. The following section will describe the configuration of input apparatus  7  with reference to  FIG. 8 . Case  1  has a substantially box-like shape and is made of insulating resin. Operation body  2  is also made of insulating resin. An upper face of operation body  2  has display section  2 C. Display section  2 C is formed so that transparent or light-colored translucent section  2 B having a predetermined shape (e.g., character, symbol, picture) for example is exposed out of non-translucent section  2 A colored with black for example. Non-translucent section  2 A is formed by a laser processing or a two-color molding for example. Operation bodies  2  are attached in opening holes of the upper face of case  1  so as to be movable in the up-and-down direction. 
     Switch  3  is a push switch for example that is formed so as to be turned ON or OFF when operation axis  3 A protruding to the upper side is moved in the up-and-down direction. Operation axis  3 A is abutted to projection  2 D at the lower face of operation body  2 . 
     Wiring substrate  4  has, at the upper and lower faces thereof, a plurality of wiring patterns (not shown). Switches  3 , light-emitting elements  5  such as light-emitting diode, and control section  6  such as a microcomputer are mounted on the upper face of wiring substrate  4 . Wiring substrate  4  is structured so that switch  3  and light-emitting element  5  are connected to control section  6  via the wiring pattern. In this manner, input apparatus  7  is configured so that case  1  covers wiring substrate  4  and control section  6  for example. 
       FIG. 9  is a front view illustrating a steering wheel including a conventional input apparatus. As shown in  FIG. 9 , input apparatuses  7  are attached to left and right spokes  9 B sandwiched between steering wheel  9  and pad  9 A accommodating the center air bag or the like so that operation bodies  2  are provided at the front faces of left and right spokes  9 B. Control section  6  is electrically connected to an electronic circuit or an electronic device (not shown) of a vehicle via a connector, a lead wire (not shown) or the like. 
     When a driver uses the configuration as described above to extend a thumb for example, while holding steering wheel  9 , to depress and operate operation body  2  on which a function that the driver intends to carry out is displayed, projection  2 D at the back face of operation body  2  presses operation axis  3 A to turn ON or OFF switch  3 . Then, an electric signal is outputted from control section  6  to an electronic circuit or an electronic device of the vehicle to control various devices provided in the automobile (e.g., to increase or decrease the volume level of an audio device or the temperature of an air conditioner). 
     When a headlight or the like is lit to illuminate the periphery of the vehicle at night for example, control section  6  controls light-emitting elements  5  to emit light. This light illuminates operation body  2  from the lower face. Light passes translucent section  2 B and illuminates display section  2 C of the upper face. This allows, even when the periphery of the vehicle is dark, the driver to visually recognize the characters, symbol, picture or the like on display section  2 C to easily identify or operate operation body  2 . 
     In other words, the driver can, without separating his or her hand(s) from steering wheel  9  on which input apparatuses  7  are attached, extend only a thumb for example to operate any of operation bodies  2  to control a device in the vehicle, thus realizing an easy operation of the device while driving. 
     A technique regarding the above-described conventional input apparatus is disclosed in Japanese Patent Unexamined Publication 2005-347193 for example. In the conventional input apparatus, operation bodies  2  have functions for operation displayed by display sections  2 C. When the periphery of the vehicle is dark, display sections  2 C are illuminated by light-emitting elements  5 . This conventional structure however had a disadvantage in that operation bodies  2  arranged to have a similar shape tended to cause an operational error such as the depression of a wrong operation body. 
     SUMMARY OF THE INVENTION 
     The input apparatus of the present invention includes: a display plate having a plurality of display sections; an electrostatic touch panel provided at a lower face of the display plate; an operation body on which the display plate and the electrostatic touch panel are placed; a plurality of light-emitting elements for illuminating the plurality of display sections of the display plate from a lower side of the display plate through the electrostatic touch panel; and a control section that is electrically connected to the electrostatic touch panel and the plurality of light-emitting elements, and that controls light emission of the plurality of light-emitting elements in accordance with touch operation to the electrostatic touch panel. 
     In the above input apparatus, when the display plate is being touched by a finger of a user for example, a plurality of display sections showing characters, a symbol, a picture or the like is illuminated. A different display section is illuminated in accordance with the movement of the finger of the user. This allows the user to clearly determine the function that the user intends to carry out. Thus, an input apparatus can be obtained that suppresses an operational error and that can be operated easily. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross-sectional view illustrating an input apparatus according to one embodiment of the present invention. 
         FIG. 2  is an exploded perspective view illustrating the input apparatus. 
         FIG. 3  is a perspective view illustrating the input apparatus. 
         FIG. 4  is a front view illustrating a steering wheel including the input apparatus. 
         FIG. 5  is a perspective view illustrating when the input apparatus is touched and operated. 
         FIG. 6  is a perspective view illustrating when the input apparatus is touched and operated. 
         FIG. 7  is a cross-sectional view illustrating when the input apparatus is depressed and operated. 
         FIG. 8  is a cross-sectional view illustrating a conventional input apparatus. 
         FIG. 9  is a front view illustrating a steering wheel including the input apparatuses. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The following section will describe an embodiment of the present invention with reference to  FIG. 1  to  FIG. 7 . 
     Embodiment 
       FIG. 1  is a cross-sectional view illustrating an input apparatus according to one embodiment of the present invention.  FIG. 2  is an exploded perspective view illustrating the input apparatus.  FIG. 3  is a perspective view illustrating the input apparatus.  FIG. 1  shows a cross section taken along the line  1 - 1  of  FIG. 3 . As shown in  FIG. 1  and  FIG. 2 , display plate  11  includes light-blocking section  11 A and cover section  11 B. Cover section  11 B has a substantially circular arc-like shape. Cover section  11 B is made of insulating resin such as acryl or Acrylonitrile-Butadiene-Styrene (ABS) that has a dark color such as brown or black and that is translucent. At the lower face of cover section  11 B, dark and non-translucent light-blocking section  11 A is provided by printing or the like. First display section  12  functioning as a display section is formed by removing a predetermined shape from light-blocking section  11 A. Second display section  13  functioning as a display section is formed by removing a substantially circular dot-like shape from light-blocking section  11 A. 
     As shown in  FIG. 3 , first display section  12  in display plate  11  shows characters, a symbol, a picture or the like representing a function for operation. At the outer side vicinities of first display sections  12 , substantially circular dot-like second display sections  13  are formed, respectively. 
     As shown in  FIG. 1  and  FIG. 2 , substantially circular arc-like electrostatic touch panel  14  is provided at the lower face of display plate  11 . Electrostatic touch panel  14  is formed by adhering lower substrate  15 , lower conductive layer  15 A, upper substrate  16 , upper conductive layer  16 A, and cover sheet  17  by adhesive agent (not shown) such as acryl or rubber, respectively. Electrostatic touch panel  14  is structured so that the upper face of film-like lower substrate  15  has thereon stripe-shaped lower conductive layers  15 A. The upper face of lower conductive layer  15 A has thereon upper substrate  16 . The upper face of upper substrate  16  has thereon stripe-shaped upper conductive layers  16 A extending in a direction orthogonal to lower conductive layer  15 A. The upper face of upper conductive layer  16 A has thereon film-like cover sheet  17 . 
     Cover  18  is made of insulating resin such as polycarbonate or ABS. Operation body  19  is also made of insulating resin. Substantially circular arc-like end section of substantially circular arc-like operation body  19  is attached within substantially circular arc-like opening hole  18 A at an end portion of cover  18  so that operation body  19  is movable in the up-and-down direction. At an end section of substantially circular arc-like operation body  19 , translucent holes  19 A are provided. At an upper face close to the end of operation body  19 , display plate  11  and electrostatic touch panel  14  are superposed and are adhered to each other by adhesive agent for example. 
     Light-guiding body  20  is made of insulating resin such as polycarbonate or ABS. Wiring substrate  21  is made of paper phenol or glass-mixed epoxy for example. Light-guiding body  20  includes light-guiding holes  20 A penetrating light-guiding body  20  in the up-and-down direction. At the upper and lower faces of wiring substrate  21 , wiring patterns (not shown) are formed by a copper foil or the like. Switch  22  such as a push switch, first light-emitting element  23 A and second light-emitting element  23 B functioning as a light-emitting element such as a light-emitting diode, and control section  24  such as a microcomputer are mounted on the upper face of wiring substrate  21 . First light-emitting elements  23 A are provided at positions corresponding to first display sections  12 , respectively. Second light-emitting elements  23 B are provided at positions corresponding to second display sections  13 , respectively. 
     Ends of lower conductive layer  15 A and upper conductive layer  16 A of electrostatic touch panel  14  are connected to control section  24  via a connector (not shown) for example. Switch  22  and first light-emitting elements  23 A and second light-emitting elements  23 B are connected to control section  24  via the wiring pattern. Operation axis  22 A protruding from switch  22  to the upper side is abutted to projection  19 B provided at the lower face of the end of operation body  19 . 
     Case  25  is made of insulating resin such as polycarbonate or ABS. On the upper face of case  25 , light-guiding body  20  and wiring substrate  21  are superposed. The end section of operation body  19  is rotatably retained by pin  26  in support hole  25 A. The upper face of case  25  is covered by cover  18  and is fixed to cover  18  by screws  27 . In this manner, input apparatus  30  is constituted. 
       FIG. 4  is a front view illustrating a steering wheel including the input apparatus according to one embodiment of the present invention. As shown in  FIG. 4 , input apparatuses  30  are attached, when seen from the upper face of display plate  11 , to left and right spokes  31 B sandwiched between steering wheel  31  and pad  31 A accommodating the center air bag or the like. Steering wheel  31  is attached to an automobile. Control section  24  is electrically connected to an electronic circuit or an electronic device (not shown) of the vehicle via a connector or a lead wire (not shown) for example. 
       FIG. 5  is a perspective view illustrating when the input apparatus is touched and operated according to one embodiment of the present invention. As shown in  FIG. 5 , the driver extends his or her thumb to touch display plate  11  while holding steering wheel  31 . Then, the capacitance of the finger causes a change in the voltage between lower conductive layer  15 A and upper conductive layer  16 A of electrostatic touch panel  14  at the lower face of display plate  11  at the position in display plate  11  touched and operated by the driver. Then, this change in the capacitance is detected by control section  24  to detect the position in display plate  11  touched by the finger. 
     At the same time, control section  24  causes first light-emitting element  23 A and second light-emitting element  23 B to emit light. This light passes light-guiding hole  20 A of light-guiding body  20 , translucent hole  19 A of operation body  19 , and electrostatic touch panel  14  to illuminate first display section  12  and second display section  13  of display plate  11  from its lower side. Then, control section  24  causes, among first light-emitting elements  23 A and second light-emitting elements  23 B, predetermined first light-emitting element  23 A and predetermined second light-emitting element  23 B to emit light. 
     With regards to first display sections  12  displaying functions for operation by characters, symbols, or pictures for example, not only first display section  12 A at a position currently touched by the finger but also the rest of first display sections  12  are also all illuminated by first light-emitting elements  23 A as shown in  FIG. 5 . 
     On the other hand, with regards to substantially circular dot-like second display sections  13  arranged at the outer side of first display sections  12 , control section  24  controls the light emission by second light-emitting elements  23 B so that only second display section  13 A at a position currently touched by the finger is illuminated and the rest of second display sections  13  are not illuminated. 
       FIG. 6  is a perspective view illustrating when the input apparatus is touched and operated according to one embodiment of the present invention. As shown in  FIG. 6 , when the driver touches first display section  12 B for example by moving the finger while still touching display plate  11  by the finger, control section  24  detects a change in the position touched by the finger as described above. Then, while all of first display sections  12  being illuminated, second display sections  13  not touched by the finger are not illuminated and only second display section  13 B touched by the finger is illuminated. 
     Specifically, when the driver touches and operates display plate  11 , first display sections  12  displaying functions for operation are all illuminated regardless of the position touched by the finger. Thus, the driver can visually recognize all function displays for operation. On the other hand, only second display section  13  touched by the finger of the driver is illuminated among second display sections  13 . Thus, the driver can easily determine on which function display the finger is currently placed. 
     Specifically, when the driver touches and operates display plate  11 , control section  24  controls the light emission of first light-emitting element  23 A and second light-emitting element  23 B to illuminate all first display sections  12 . Thus, the driver can easily visually recognize all function displays even when the periphery is slightly dark. Furthermore, among second display sections  13  arranged with first display sections  12 , only second display section  13  currently touched by the finger of the driver is illuminated. Thus, the driver can select a function for operation easily. Thus, an operational error can be prevented and an easy input operation can be realized. 
       FIG. 7  is a cross-sectional view illustrating when the input apparatus is depressed and operated according to one embodiment of the present invention.  FIG. 7  illustrates when the input apparatus is depressed and operated in the cross-sectional view of the input apparatus of  FIG. 1 . 
     When the driver depresses and operates a function display for operation in display plate  11  in the direction shown by arrow  32  as shown in  FIG. 7  while touching first display section  12 B of  FIG. 6  by the finger, operation body  19  whose upper face has thereon display plate  11  and electrostatic touch panel  14  is oscillated and rotated around support hole  25 A of case  25  as a supporting point. Then, projection  19 B provided at the lower face of operation body  19  presses operation axis  22 A of switch  22 , thereby turning ON or OFF switch  22 . 
     The ON or OFF of switch  22  is detected by control section  24 . An electric signal showing the ON or OFF and a signal showing the contact of first display section  12 B are outputted from control section  24  to the electronic circuit or the electronic device of the vehicle to control various devices provided in the automobile that correspond to the functions displayed on display plate  11 . Thus, the driver can speak through a telephone connected to the vehicle, for example. 
     In other words, control section  24  is electrically connected to electrostatic touch panel  14 , first light-emitting element  23 A, and second light-emitting element  23 B. Control section  24  controls the light emission of first light-emitting elements  23 A and second light-emitting elements  23 B in accordance with the touch operation of electrostatic touch panel  14 . 
     Even when the driver depresses and operates a function display for operation in display plate  11  while touching another first display section  12  other than first display section  12 B of  FIG. 6  by the finger, operation body  19  is rotated as described above to turn ON or OFF switch  22 . This electric signal showing ON or OFF is outputted from control section  24 . In this case, the position of display plate  11  touched and operated by the driver is different from that in the above-described case. Thus, a signal showing the position at which display plate  11  is touched is outputted to control other devices (e.g., to increase or decrease the volume level of an audio device or the temperature of an air conditioner). 
     When display plate  11  is touched by the finger of the driver and is depressed and operated, control section  24  detects the position touched and operated via electrostatic touch panel  14  and detects ON or OFF of switch  22  to output these signals. In this manner, switch  22  making ON or OFF by the up-and-down movement of operation body  19  is provided and various devices provided in the vehicle are controlled by allowing control section  24  to detect the ON or OFF of switch  22 . 
     Specifically, control section  24  detects both the touched position of electrostatic touch panel  14  and the ON or OFF of switch  22 . This eliminates the need to provide a plurality of switches. Thus, switch  22  can be used to constitute input apparatus  30 , thus realizing a simple and low-cost apparatus. 
     Furthermore, display plate  11  and electrostatic touch panel  14  or the like formed to have a substantially circular arc-like shape as described above allow input apparatus  7  to be attached to steering wheel  31  of the vehicle in an easy manner. This allows the driver to move, while holding steering wheel  31  to which input apparatus  7  is attached, the tip end of his or her thumb over display plate  11  so as to draw a substantially circular arc-like line to easily touch and operate and to depress and operate display plate  11 . 
     The above section has described the following configuration. Specifically, first display sections  12  showing functions for operation and substantially circular dot-like second display sections  13  are displayed and arranged on display plate  11 . When display plate  11  is touched and operated by the driver, all first display sections  12  are illuminated and only second display section  13  touched by the finger is illuminated. 
     However, the present invention also can be carried out in another configuration in which second display section  13  is eliminated and a touched-and-operated position of first display section  12  is illuminated instead. 
     In this case however, only the touched-and-operated position of first display section  12  is illuminated. Thus, when the position touched by the finger is not a position showing the function that the driver intends to carry out, the driver is required to further move the finger to select a position for operation. Thus, another configuration above mentioned causes, although an operational error can be avoided, a slightly-complicated operation when compared with the above-described configuration. 
     As described above, according to the input apparatus of the embodiment of the present invention, display plate  11  having first display sections  12  and second display sections  13  and electrostatic touch panel  14  are provided on operation body  19 . In accordance with the touch operation of electrostatic touch panel  14 , control section  24  controls the light emission of first light-emitting element  23 A and second light-emitting element  23 B. This allows, when display plate  11  is being touched by the finger of the user, all first display sections  12  showing functions for operation for example are illuminated. In accordance with the movement of the finger, the position at which second display section  13  is illuminated is changed. This enables the user to clearly determine a function that the user intends to carry out. Thus, input apparatus  30  can be obtained that suppresses an operational error and that can be operated easily. 
     The above section has described the configuration using a single push switch as switch  22 . However, the present invention also can be carried in another configuration that uses a switch obtained by providing a fixed contact point made of carbon or the like on the upper face of wiring substrate  21  and by placing a movable contact point made of a substantially dome-like conductive thin metal plate above the fixed contact. Also the present invention can be carried by using a switch using a substantially dome-like flexible rubber contact point whose lower face has a movable contact point for example. 
     The above section has described the configuration in which control section  24  is integrated with input apparatus  30 . However, the present invention also can be carried in another configuration in which control section  24  provided in an electronic circuit of the vehicle detects the touch operation of electrostatic touch panel  14  and the ON or OFF of switch  22  to control the light emission of first light-emitting element  23 A and second light-emitting element  23 B. 
     The input apparatus of the present invention suppresses an operational error and can be operated easily. The input apparatus of the present invention is mainly useful for the control of various electronic devices of an automobile.