Patent Publication Number: US-8125450-B2

Title: Operating device for vehicle

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is based on Japanese Patent Application No. 2008-58029, which is filed on Mar. 7, 2008, the disclosure of which is incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The present invention relates to an operating device for a vehicle, which outputs a signal corresponding to a pushing force applied to an operating portion. 
     BACKGROUND OF THE INVENTION 
     A joystick device (a joystick type input device) is conventionally known in the art, for example as disclosed in Japanese Patent Publication No. 2002-207553, according to which a signal corresponding to an operating direction (an upward direction, a downward direction, a left-hand direction, a right-hand direction) and an operating amount of a joystick is outputted. In addition, a push detecting signal is outputted from the joystick device, when a pushing force is applied to the joystick in its axial direction. 
     According to the above joystick type input device, the joystick is operated in the respective directions (up-and-down direction, and left-and-right direction), and a forward end of the joystick is pushed by a thumb in the axial direction of the joystick, so that a decision of operation is done. According to such joystick device, however, it is required for an operator to correctly push the joystick in a direction of a supporting axis. Otherwise, the joystick may be inclined and a displacement may occur, resulting in a malfunction. 
     The above joystick type input device, in which the forward end of the joystick is pushed by the thumb, may be suitable for game machines. Such input device, however, is not adequate to be applied to an input device for a vehicle. 
     Since the input device for the vehicle is generally located at a center console of the vehicle, it is not adequate to push the forward end of the joystick by the thumb. Such an input device is desirable for the vehicle, which an operator may operate by his one hand not only to decide direction and but also to carry out a decision operation. 
     In the case that the input device is located at the center console of a vehicle, in particular of a right-handle vehicle, it is necessary for a vehicle driver to operate such input device with his left hand. And thereby, it is further undesirable in view of operationality, for the driver, to change the direction of the joystick and to push the forward end of the joystick. 
     SUMMARY OF THE INVENTION 
     The present invention is made in view of the above problems. It is an object of the present invention to provide an operating device for a vehicle having an improved operationality. 
     According to a feature of the invention, an operating device for a vehicle has an operating portion, a signal outputting portion for outputting a signal in accordance with pushing force from the operating portion, and a supporting portion for movably supporting the operation portion and the signal outputting portion, such that the operation portion and the signal outputting portion move along an operation surface. In such operating device, the operating portion moves in a direction perpendicular to the operation surface and transmits the pushing force to the signal outputting portion, when the operating portion receives the pushing force in the direction perpendicular to the operation surface. 
     According to such a structure, the signal outputting portion moves together with the operating portion along the operation surface. The operating portion moves in the direction perpendicular to the operation surface and transmits pushing force to the signal outputting portion, when the operating portion receives the pushing force in the direction perpendicular to the operation surface. Accordingly, it is possible for a vehicle driver to put his one hand on the operating device to move the operating portion along the operation surface and applies the pushing force to the operating portion in the direction perpendicular to the operation surface, so that the signal outputting portion may output a signal corresponding to the pushing force. As a result, operationality is improved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings. In the drawings: 
         FIG. 1  is a schematic perspective view showing an operating device for a vehicle according to an embodiment of the present invention; 
         FIG. 2  is a schematic exploded perspective view showing the operating device for the vehicle; 
         FIG. 3  is a view showing an inside structure of the joystick device; 
         FIG. 4  is a view explaining a concavo-convex portion formed on an operation knob; 
         FIG. 5  is a top plan view showing the operating device for the vehicle, from which the operation knob and a bezel are removed; 
         FIG. 6A  is a cross sectional view of the operating device, taken along a line VI-VI in  FIG. 5 , in which the operation knob is positioned at its center; 
         FIG. 6B  is a cross sectional view of the operating device, taken along the line VI-VI in  FIG. 5 , in which the operation knob is moved in X direction; 
         FIG. 7  is an enlarged view showing a portion VII indicated in  FIG. 6B ; 
         FIG. 8A  is a cross sectional view of the operating device, taken along a line VIII-VIII in  FIG. 5 , in which the operation knob is positioned at its center; 
         FIG. 8B  is a cross sectional view of the operating device, taken along the line VIII-VIII in  FIG. 5 , in which the operation knob is moved in Y direction; 
         FIG. 9  is an enlarged view showing a portion IX indicated in  FIG. 8B ; 
         FIG. 10A  is a schematic view showing relative positions between the operation knob and the bezel, wherein the operation knob is positioned at a center of the opening; 
         FIG. 10B  is a schematic view showing the relative positions between the operation knob and the bezel, in which the operation knob is moved to an end of the opening; 
         FIG. 11  is a schematic view showing a display system having an operating apparatus with the operating device for the vehicle; 
         FIG. 12  is a schematic view showing an example of a main menu panel; 
         FIG. 13  is a schematic cross-sectional view showing portions of the bezel and the operation knob, in which flanged portions are formed; 
         FIG. 14  is a schematic perspective view showing the operation knob, in which a circular concave portion is formed on an upper side thereof; 
         FIG. 15  is a schematic perspective view showing the operation knob, in which a meshed concavo-convex portion is formed on the upper surface of the operation knob; and 
         FIGS. 16A and 16B  are schematic views showing a hinge provided on X-direction sliding unit. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  is a schematic perspective view showing an operating device for a vehicle according to an embodiment of the present invention. As shown in  FIG. 1 , the operating device  1  for the vehicle has a lower casing  10  for accommodating a joystick device  20 , a base member  30  fixed to the lower casing  10 , an upper casing  70  fixed to the base member  30 , a bezel  72  fixed to the base member  30  together with the upper casing  70 , and an operation knob  80  arranged at an upper surface of the bezel  72 . 
     The bezel  72  is fixed to the base member  30 , but the operation knob  80  is movable not only in a horizontal direction (in an X direction in the drawing) but also in a cross section (in a Y direction in the drawing), wherein an upper surface of the bezel  72  is serving as an operation surface, so that the operation knob  80  is moved downwardly, i.e. in a direction perpendicular to the operation surface, depending on an operation of an operator. 
       FIG. 2  is a schematic exploded perspective view showing the operating device  1  for the vehicle. A structure of the operating device  1  will be explained with reference to the drawing. 
     The lower casing  10  accommodates the joystick device  20 . 
     The joystick device  20  outputs a signal, which corresponds to a movement of a forward end of an axial rod  21 , from a connector  22 . 
       FIG. 3  shows an inside structure of the joystick device  20 . The joystick device  20  has an X-axis encoder  23  for detecting rotational displacement of a supporting axis, wherein axial rod  21  is rotated around the supporting axis and the rotational displacement depends on an operation in a direction of the X-axis of the axial rod  21 . The joystick device  20  further has a Y-axis encoder  24  for detecting rotational displacement of a supporting axis, wherein the rotational displacement depends on an operation in a direction of the Y-axis of the axial rod  21 . Then, the joystick device  20  outputs a signal depending on respective rotational displacements detected by the X-axis encoder  23  and the Y-axis encoder  24 . 
     In some kinds of the joystick devices, an operating load for the X-axis is made to be different from that for the Y-axis. In the joystick device  20  according to the embodiment, the operating load for the X-axis and the operating load for the Y-axis are made to be equal to each other. 
     The base member  30  is fixed to the lower casing  10  by means of screws  32 , after the joystick device  20  is accommodated in the lower casing  10 . 
     An opening is formed at a center of the base member  30 , through which the axial rod  21  of the joystick device  20  passes. A pair of rails  31  (Y-direction rails), which is in parallel with the Y direction, is formed at a periphery of the opening. 
     Four cylindrical rollers  42  are rotatably assembled to four corners of a lower surface of a Y-direction sliding unit  40 . Then, the Y-direction sliding unit  40  is assembled to an upper surface of the base member  30 , such that each of the rollers  42  rotates on and moves along the Y-direction rails  31 . As above, the Y-direction sliding unit  40  is movable in the Y direction on the upper surface, wherein the pair of the Y-direction rails  31  is arranged in parallel to each other. Since the rollers  42  are assembled to the Y-direction sliding unit  40 , friction generated when the Y-direction sliding unit  40  moves in the Y direction is decreased, so that the Y-direction sliding unit  40  can smoothly move. 
     In a similar manner to the base member  30 , an opening is formed at a center of the Y-direction sliding unit  40 , through which the axial rod  21  of the joystick device  20  passes. And a pair of rails  41  (X-direction rails), which is in parallel with the X direction, is formed at a periphery of the opening. 
     In a similar manner to the Y-direction sliding unit  40 , four cylindrical rollers  52  are rotatably assembled to four corners of a lower surface of an X-direction sliding unit  50 . Then, the X-direction sliding unit  50  is assembled to an upper side of the Y-direction sliding unit  40 , such that each of the rollers  52  rotates on and moves along the X-direction rails  41 . As above, the X-direction sliding unit  50  is movable in the X direction on the upper side, wherein the pair of the X-direction rails  41  is arranged in parallel to each other. Since the rollers  52  are assembled to the X-direction sliding unit  50 , friction generated when the X-direction sliding unit  50  moves in the X direction is decreased, so that the X-direction sliding unit  50  can smoothly move. 
     According to the embodiment, the X-direction sliding unit  50  is arranged above the Y-direction sliding unit  40  so that a load of the X-direction sliding unit  50  is applied to the Y-direction sliding unit  40 . The operating load for the X-direction sliding unit  50  in the horizontal direction of the operation knob  80  is made smaller than the operating load for the Y-direction sliding unit  40  in the cross direction of the operation knob  80 . 
     In general, an operating screen is landscape. Therefore, a moving operation in the X direction is carried out more often than a moving operation in the Y direction. Accordingly, as explained above, when the operating load for the X-direction sliding unit  50  in the horizontal direction of the operation knob  80  is made smaller than the operating load for the Y-direction sliding unit  40  in the cross direction of the operation knob  80 , an operating burden for moving the operation knob  80  in the X direction can be reduced. 
     When the operation knob  80  is moved on the operation surface, a movement in the cross direction (in the Y direction) is generally slower, whereas a movement in the horizontal direction (in the X direction) becomes faster. Due to this fact, the operating load for the operation knob  80  in the horizontal direction is made smaller in order to make inertia in the horizontal direction of the operation knob  80  smaller. On the other hand, the operating load for the operation knob  80  in the cross direction is made larger in order to make inertia in the cross direction of the operation knob  80  larger. As a result, operationality of the operation knob  80  is improved. 
     Furthermore, materials for the X-direction rails  41  and the Y-direction rails  31  are different from each other, so that coefficient of dynamic friction in case of the X-direction sliding unit  50  moving on the X-direction rails  41  is made smaller than coefficient of dynamic friction in case of the Y-direction sliding unit  40  moving on the Y-direction rails  31 . For example, the material for the base member  30  on which the Y-direction rails  31  are formed is ABS resin, whereas the material for the Y-direction sliding unit  40  on which the X-direction rails  41  are formed is POM resin. The POM resin has a lower coefficient of friction than that of the ABS resin, so that the POM resin is more slippery than the ABS resin. 
     Accordingly, in the case that the ABS resin is selected as the material for the Y-direction rails  31  and the POM resin is selected as the material for the X-direction rails  41 , the coefficient of dynamic friction for the X-direction rails  41  is made smaller than that for the Y-direction rails  31 , when compared with a case in which the ABS resin is used for both of them. 
     A ball bearing  54  is formed into a spherical shape made of metal or synthetic resin. A though-hole, through which the axial rod  21  of the joystick device  20  passes, is formed in the ball bearing  54 . When the axial rod  21  is inserted into the through-hole, the axial rod  21  is movable in an axial direction with respect to the through-hole. 
     A lower sliding cover  53  of a patelliform is fixed to a lower surface of the X-direction sliding unit  50  by means of bolts  57 , so that the ball bearing  54  is interposed therebetween and rotatbly supported. 
     Guide portions  51   a  are formed at an upper side, such that the guide portions  51   a  are held by a stem  56  and the stem  56  is guided by the guide portions  51   a  to move in a vertical direction. 
     The stem  56  moves in the vertical direction along the guide portions  51   a . The stem  56  has a projection  56   b  which is engaged with a recess (not shown) formed at a lower side of the operation knob  80 . 
     A push switch  55  is arranged at a center of the guide portions  51   a . The push switch  55  closes its contacts when the push switch  55  receives a pushing force from the operation knob  80  in a vertical and downward direction via the stem  56 . On the other hand, the push switch  55  opens its contacts by spring force of a return spring when the pushing force disappears. And the operation knob  80  as well as the stem  56  is brought back to their initial positions. As above, the push switch  55  is turned on or turned of, depending on the pushing force. 
     The push switch  55  has two terminals, one of which is connected to a battery via a pull-up resistor and the other of which is grounded. When the push switch  55  is turned off, the terminals are opened, so that a voltage equal to battery voltage is outputted from the terminal connected to the battery via the pull-up resistor. When the push switch  55  is turned off, the two terminals are short-circuited, and grounded voltage is outputted from the terminal connected to the pull-up resistor. 
     An upper sliding cover  60  prevents the X-direction sliding unit  50  from falling away. The upper sliding cover  60  is fixed to the Y-direction sliding unit  40  by means of bolts  61 , wherein the X-direction sliding unit  50  is arranged between the bolts  61 . 
     The upper casing  70  prevents the Y-direction sliding unit  40 . The upper casing  70  is fixed to the base member by means of bolts  71 , wherein the Y-direction sliding unit  40  is arranged between the bolts  71 . 
     The bezel  72  is formed of resin and formed into a plate shape. The bezel  72  is slightly bent in the cross direction (in the X direction) so that the operation surface is formed into a curved surface having a predetermined curvature radius in the X direction. The operation surface is also bent in the Y direction, so that the curved surface also has a predetermined curvature radius in the Y direction. The curvature of radius of the curved surface in the Y direction is larger than that in the X direction. 
     The above explained curved surface is more desirable than the flat surface, because such curved surface fits better to movements of a hand and/or fingers of the operating person. According to the embodiment, therefore, the operation surface is formed as the curved surface in view of the operationality. 
     An opening  72   a , though which the stem  56  passes, is formed at a center of the bezel  72 . 
     The operation knob  80  may be made of resin or metal, and a concavo-convex portion is formed in the horizontal direction (the X direction) and in the cross direction (the Y direction), as shown in  FIG. 4 . Any slippage is prevented by such concavo-convex portion to improve the operationality. In  FIGS. 1 ,  2 ,  6  to  10 ,  13  and  16 , illustration for the concavo-convex portion is omitted. 
     The projection  56   b  of the stem  56  is press-fitted into the recess (not shown) formed at the lower side of the operation knob  80  in order that the operation knob  80  is assembled to the stem  56 , after the bezel  72  is fixed to the base member  30 . The stem  56  may be connected to the lower side of the operation knob  80  by means of screws. 
     According to the embodiment, a curvature of an upper surface of the X-direction rails  41  formed on the Y-direction sliding unit  40  is made to be equal to a curvature of the bezel  72  in the X direction, so that the operation knob  80  moves along the curved surface of the bezel  72  when the operation knob  80  is operated in the X direction. In a similar manner, a curvature of an upper surface of the Y-direction rails  31  formed on the base member  30  is made to be equal to a curvature of the bezel  72  in the Y direction, so that the operation knob  80  moves along the curved surface of the bezel  72  when the operation knob  80  is operated in the Y direction. 
     The opening  72   a  formed in the bezel  72  has such a size that the stem  56  does not interfere with the opening  72   a  even when the operation knob  80  is moved in the X direction or Y direction to respective maximum movable end positions. 
       FIG. 5  is a top plan view showing the operating device  1  for the vehicle, from which the operation knob  80  and the bezel  72  are removed.  FIG. 6  is a cross-sectional view taken along a line VI-VI in  FIG. 5 .  FIG. 6A  shows the cross sectional view of the operating device  1 , in which the operation knob  80  is positioned at its center, and  FIG. 6B  shows the cross sectional view of the operating device  1 , in which the operation knob  80  is moved in the X direction. 
     As shown in  FIG. 6A , in which the operation knob  80  is positioned at its center, each center of the operation knob  80 , the stem  56  and the ball bearing  54  is positioned on a reference line, which extends in the vertical direction from the supporting axis of the axial rod  21  of the joystick device  20 . 
     When the operation knob  80  is moved in the X direction together with the X-direction sliding unit  50 , the stem  56  as well as the ball bearing  54  is moved in the X direction together with the operation knob  80 , as shown in  FIG. 6B . During such movement, the ball bearing  54  rotates on the sliding cover  53  and slides in the axial direction of the axial rod  21  of the joystick device  20 . At the same time, the forward end of the axial rod  21  of the joystick device  20  is moved in the X direction together with the ball bearing  54 . Then, the signal corresponding to such movement of the forward end of the axial rod  21  is outputted from the connector  22 . 
     A turning-radius of the forward end of the axial rod  21  is defined by a length of the axial rod  21  of the joystick device  20 . The forward end of the axial rod  21  moves on a surface having a relatively small curvature. However, as explained above, because of a structure in which the ball bearing  54  moves in the axial direction of the axial rod  21  of the joystick device  20 , it becomes possible to move the operation knob  80  on the operation surface having a larger curvature. The forward end of the axial rod  21  of the joystick device  20  can be moved in accordance with the movement of the operation knob  80 . 
       FIG. 7  is an enlarged view showing a portion VII indicated in  FIG. 6B . When the operation knob  80  receives the pushing force in the direction perpendicular to the operation surface, the pushing force is transmitted to the push-switch  55  via the stem  56 , so that the push-switch  55  is turned on. 
     Since the operation knob  80  is so arranged to move downwardly in accordance with a pushing operation in the vertical and downward direction to the operation surface, it is possible even for an inexperienced person to operate the operation knob  80  without causing displacement thereof. 
     The upper surfaces of the pair of the Y-direction rails  31 , which are formed on the surface of the base member  30  in parallel to each other, are respectively inclined toward the inside of the Y-direction rails  31 . Accordingly, the Y-direction sliding unit  40  is centered by its own weight and weight of the operation knob  80 , because the upper surfaces of the Y-direction rails  31  are inclined. Furthermore, the Y-direction sliding unit  40  moves while it is always in contact with the Y-direction rails  31 . As a result, saccadic movement can be reduced when the Y-direction sliding unit  40  moves on the Y-direction rails  31 . 
       FIG. 8  is a cross-sectional view taken along a line VIII-VIII in  FIG. 5 .  FIG. 8A  shows the cross sectional view of the operating device  1 , in which the operation knob  80  is positioned at its center, whereas  FIG. 8B  shows the cross sectional view of the operating device  1 , in which the operation knob  80  is moved in the Y direction. 
     As shown in  FIG. 8A , in which the operation knob  80  is positioned at its center, each center of the operation knob  80 , the stem  56  and the ball bearing  54  is positioned on a reference line, which extends in the vertical direction from the supporting axis of the axial rod  21  of the joystick device  20 . 
     When the operation knob  80  is moved in the Y direction, the stem  56  and the ball bearing  54  are moved in the Y direction together with the operation knob  80 , as shown in  FIG. 8B . During such movement, the ball bearing  54  rotates on the sliding cover  53  and slides in the axial direction of the axial rod  21  of the joystick device  20 . At the same time, the forward end of the axial rod  21  of the joystick device  20  is moved in the Y direction together with the ball bearing  54 . Then, the signal corresponding to such movement of the forward end of the axial rod  21  is outputted from the connector  22 . 
       FIG. 9  is an enlarged view showing a portion IX indicated in  FIG. 8B . When the operation knob  80  receives the pushing force in the direction perpendicular to the operation surface, the pushing force is transmitted to the push-switch  55  via the stem  56 , so that the push-switch  55  is turned on. 
     The upper surfaces of the pair of the X-direction rails  41 , which are formed on the surface of the Y-direction sliding unit  40  in parallel to each other, are respectively inclined toward the inside of the X-direction rails  41 , as in a similar manner to the Y-direction rails  31 . As a result that the upper surfaces of the X-direction rails  41  are inclined, saccadic movement can be reduced when the X-direction sliding unit  50  moves on the X-direction rails  41 . 
     According to the embodiment, the opening  72   a  formed on the bezel  72  can not be recognized from the outside, even when the operation knob  80  is moved in the X direction or Y direction to their maximum movable end positions. In other words, the operation knob  80  is designed to have such dimension, according to which the opening  72   a  formed on the bezel  72  can not be recognized from the outside, even in the case that the operation knob  80  is moved in the X direction or Y direction to their maximum movable end positions. 
     The dimension of the operation knob  80  will be explained with reference to  FIG. 10 .  FIG. 10A  is a view showing relative positions between the operation knob  80  and the bezel  72 , wherein the operation knob  80  is positioned at a center of the opening  72   a , whereas  FIG. 10B  shows the relative positions in which the operation knob  80  is moved to an end of the opening  72   a.    
     In  FIGS. 10A and 10B , “D” designates a moving distance of the operation knob  80 , “W” designates a width of a supporting axis (corresponding to the projection  56   b  of the stem  56 ) for supporting the operation knob  80 , and “C” designates a clearance (gap) between the operation knob  80  and the operation surface of the bezel  72 . Furthermore, “θ” designates an angle formed between the surface of the bezel  72  and a direction toward an operator&#39;s eye, when the opening  72   a  is viewed through the gap between the operation knob  80  and the bezel  72 , wherein the operation knob  80  is moved to the end of the opening  72   a , as shown in  FIG. 10B . “Lmin” designates a minimum length of a side of the operation knob  80 . 
     The following formula is formed:
 
 L min/2= D+W/ 2+ C /tan θ
 
that is,  L min=2 D+W+ 2 C /tan θ
 
     In case that D=15 mm, W=12 mm, C=1 mm, and θ=30°, the minimum length of the side for the operation knob  80  is calculated as “Lmin≅46 mm”. Namely, when the length of the side for the operation knob  80  is designed to be larger than 46 mm, it becomes possible that the opening  72   a  can not be recognized from the outside. 
       FIG. 11  shows a display system having an operating apparatus  100  with the operating device  1  for the vehicle, a navigation ECU  200  and a display device  300 . 
     The operating apparatus  100  has the X-axis encoder  23  and the Y-axis encoder  24  assembled into the joystick device  20 , the push switch  55  which is turned on and off in accordance with the movement of the operation knob  80  in the vertical direction, a CPU  110  for performing calculation, and a communication interface circuit  120 . The X-axis encoder  23 , the Y-axis encoder  24  and the push switch  55  are assembled into the operating device  1 . 
     The CPU  110  calculates moving distances of the operation knob  80  on the operation surface in the X direction and the Y direction, based on the signals from the X-axis encoder  23  and the Y-axis encoder  24 . In addition, the CPU  110  determines whether the push switch  55  is turned on or off. The CPU  110  sends a signal for the moving distances of the operation knob  80  in the X and Y directions as well as a signal for turned-on or turned-off condition of the push switch  55  to the navigation ECU  200  through the communication interface circuit  120 . 
     The navigation ECU  200  displays information on the display device  300 , which correspond to the signal for the moving distances of the operation knob  80  in the X and Y directions as well as the signal for turned-on or turned-off condition of the push switch  55 . 
       FIG. 12  shows an example of a main menu panel. On the menu panel, respective switches for “Navi” (navigation), “Air Con” (air conditioner), “Audio”, “Vehicle”, “Information”, and “Setting” are displayed. In addition, a pointer “P”, which moves on the display panel in accordance with the movement of the operation knob  80  of the operating apparatus  100 , is displayed. 
     When the operator moves the operation knob  80  on the operation surface in the horizontal direction (in the X direction), the pointer “P” moves on the display panel in a left-and-right direction. When the operator moves the operation knob  80  on the operation surface in the cross direction (in the Y direction), the pointer moves on the display panel in an up-and-down direction. 
     As shown in  FIG. 12 , a length of the display panel of the display device  300  in the horizontal direction is made longer than a length in the vertical direction. In accordance with such configuration of the display panel of the display device  300 , a maximum moving amount (maximum movable distance) of the operation knob  80  in the horizontal direction is made longer than a maximum moving amount (maximum movable distance) of the operation knob  80  in the cross direction. 
     A turn-on signal of the push switch  55  is inputted from the operating apparatus  100  to the navigation ECU  200 , when the operator moves the operation knob  80  on the operation surface and pushes down the operation knob  80  in the vertical direction perpendicular to the operation surface of the operating apparatus  100  after the operator locates the pointer “P” at his desired switch on the display panel. The navigation ECU  200  carries out a function related to the switch on the display panel selected by the pointer “P”, in accordance with the turn-on signal of the push switch  55 . For example, when the turn-on signal of the push switch  55  is inputted while the pointer “P” is located on the switch indicating “Navi”, a screen of the display panel is changed to other screens for carrying out various kinds of functions related to the car navigation. 
     According to the above explained structure, the push switch  55  is moved together with the operation knob  80  along the operation surface. And when the operation knob  80  receives the pushing force in the vertical direction perpendicular to the operation surface, the operation knob  80  is moved in the vertical direction so that the operation knob  80  transmits the pushing force to the push switch  55 . Accordingly, it is possible to hold by one hand the operation knob  80  in a movable manner on the operation surface and to apply the pushing force to the operation knob  80  in the vertical direction, so that the signal corresponding to the pushing force is outputted from the push switch  55 . The operationality is thereby improved. 
     The invention shall not be limited to the above embodiment, but can be modified in various ways based on the points of the invention. 
     For example, although the bezel  72  is provided in the above embodiment, the bezel  72  is not always necessary. 
     As shown in  FIGS. 10A and 10B , there is formed the gap between the operation knob  80  and the bezel  72 , wherein the gap is formed as a relatively large gap. As a result, it may happen that dust or foreign matter gets into the opening  72   a  formed in the bezel  72  through the gap. Accordingly, as shown in  FIG. 13 , a flanged portion  72   b  may be formed at the periphery of the opening  72   a  formed in the bezel  72 , wherein the flanged portion  72   b  project toward the upper side of the bezel  72 . Alternatively, a flanged portion  80   a  may be formed at a periphery of the operation knob  80  on the side to the bezel  72 , in order to prevent the dust or the foreign matter from getting into the opening  72   a.    
     As shown in  FIG. 4 , according to the above embodiment, the concavo-convex portion is formed in the horizontal direction (the X direction) and in the cross direction (the Y direction) on the upper side surface of the operation knob  80 . A circular concave may be formed at a center of the upper surface of the operation knob  80 , as shown in  FIG. 14 . Alternatively, a circular convex may be formed at the center of the upper surface of the operation knob  80 . 
     Furthermore, a meshed concavo-convex portion may be formed on the upper surface of the operation knob  80 , as shown in  FIG. 15 . 
     As shown in  FIG. 2 , according to the above embodiment, the operation knob  80  as well as the stem  56  is arranged so that they move in the vertical direction along the guide portion  51   a  formed on the upper side of the X-direction sliding unit  50 . However, as shown in  FIGS. 16A and 16B , a pivot axis  51   c  may be provided on the upper side of the X-direction sliding unit  50  and a hinge  51   b  may be provided at the pivot axis  51   c  so that the hinge  51   b  may move up and down around the pivot axis  51   c . The operation knob  80  may be so arranged that the operation knob  80  may move in the vertical direction by means of the hinge  51   c.    
     According to the above embodiment, the push switch  55  is arranged on the X-direction sliding unit  50 , and the stem  56  is interposed between the operation knob  80  and the push switch  55 . However, the push switch  55  may be provided in the operation knob  80  and the operation knob  80  may be fixed to the X-direction sliding unit  50  by any suitable supporting members (not shown). 
     Furthermore, according to the above embodiment, the push switch  55  is arranged to be turned-on or turned-off depending on the pushing force applied to the operation knob  80 . Namely, the push switch  55  is provided as a signal outputting means, which generates a signal depending on the pushing force received from the operation knob  80 . A pressure sensor, a displacement sensor or any other sensors may be used as the signal outputting means, in place of the push switch  55 . 
     Furthermore, according to the above embodiment, the bezel  72  is formed as the curved surface having the predetermined curvatures not only in the horizontal direction but also on the cross direction. The bezel  72  may be formed as a curved surface having a predetermined curvature only in the horizontal direction, or the bezel  72  may be formed as a curved surface having a predetermined curvature only in the cross direction. Furthermore, the bezel  72  may be formed as a flat plate. 
     Furthermore, according to the above embodiment, the operation knob  80  is moved on the operation surface to any desired position by the Y-direction sliding unit  40  and the X-direction sliding unit  50 . The operation knob  80  may have either one of the Y-direction sliding unit  40  and the X-direction sliding unit  50 . 
     As mentioned above, the operation knob  80  is moved on the operation surface to any desired position by the Y-direction sliding unit  40  and the X-direction sliding unit  50 , according to the embodiment. The Y-direction sliding unit  40  may be arranged so that it is inclined at 45° in the horizontal direction, whereas the X-direction sliding unit  50  may be inclined at 45° in the cross direction. Then, the Y-direction sliding unit  40  may be provided on the X-direction sliding unit  50 , or vice versa, so that the operation knob  80  may be moved on the operation surface to any desired position. 
     Furthermore, according to the above embodiment, the operating load for the X-direction sliding unit  50  in the horizontal direction of the operation knob  80  is made smaller than the operating load for the Y-direction sliding unit  40  in the cross direction of the operation knob  80 . Contrary to that, the operating load for the Y-direction sliding unit  40  in the cross direction of the operation knob  80  may be made smaller than the operating load for the X-direction sliding unit  50  in the horizontal direction of the operation knob  80 . Alternatively, the operating loads for the operation knob  80  may be made substantially equal to each other in the horizontal direction and in the cross direction. 
     Furthermore, according to the above embodiment, the maximum movable distance of the operation knob  80  in the horizontal direction is made longer than the maximum movable distance of the operation knob  80  in the cross direction, in accordance with the configuration of the display panel of the display device  300 . However, the maximum movable distances of the operation knob  80  in the horizontal direction and in the cross direction may be made to be almost equal to each other. Contrary to that, the maximum movable distance of the operation knob  80  in the horizontal direction may be made shorter than the maximum movable distance in the cross direction. 
     Furthermore, according to the joystick device  20  of the above embodiment, the operating load for the X-axis and the operating load for the Y-axis are made to be equal to each other. 
     However, in the case of the joystick device  20 , in which the operating load for the X-axis and the operating load for the Y-axis are different from each other, the operating loads for the operation knob  80  may be made to be different from each other in the horizontal direction and in the cross direction. In addition, the joystick device  20  may be provided in the lower casing  10  in such a manner that the operating loads for the operation knob  80  and the operating loads for the joystick  20  are counterbalanced with each other in the X-axis and Y-axis. Contrary to that, the joystick device  20  may be provided in the lower casing  10  in such a manner that the operating load for the operation knob  80  and the operating load for the joystick  20  in a certain direction may be reinforced. 
     According to the above embodiment, the upper surfaces of the Y-direction rails  31  and the upper surfaces of the X-direction rails  41 , which are respectively formed in parallel to each other, are inclined toward the inside of the respective rails  31  and  41 . However, the upper surfaces may not be always inclined. 
     According to the above embodiment, as shown in  FIG. 2 , the X-direction sliding unit  50  is arranged above the Y-direction sliding unit  40 . Contrary to that, the Y-direction sliding unit  40  may be arranged above the X-direction sliding unit  50 . 
     According to the above embodiment, the whole area of the operation surface for the bezel  72  is formed as the curved surface having the predetermined curvatures not only in the horizontal direction but also in the cross direction. However, a portion of the operation surface for the bezel, for example, a left-hand portion, a right-hand portion, a front-side portion, a back-side portion, a center portion, may be formed as a curved surface.