Abstract:
An input operation system for use in a vehicle has a protruding marking on a surface of a touch panel, and displays a composite image generated by superposing an outline of user&#39;s finger on a switch operation screen. The composite image of the switch operation screen is backed by an image of the protruding marking on the surface of the touch panel, and the user&#39;s finger receives a tactile feedback from the protruding marking on the surface of the touch panel to cause sensations of an intuitive positioning in the switch operation screen for controlling a menu item that is displayed on a display unit for an input operation of vehicular devices.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application is based on and claims the benefit of priority of Japanese Patent Application No. 2006-133879 filed on May 12, 2006, the disclosure of which is incorporated herein by reference. 
       FIELD OF THE INVENTION 
       [0002]    The present invention generally relates to an input operation system for use in a vehicle. 
       BACKGROUND INFORMATION 
       [0003]    In recent years, various techniques are disclosed for easily locating a button in a switch operation screen displayed on a touch sensitive panel of a display unit. For example, Japanese patent document JP-A-H07-319623 discloses a touch panel that has a transparent sheet disposed thereon with a protrusion for indicating a button position. Further, Japanese patent document JP-A-H10-269012 discloses an apparatus including a touch panel for sensing a touching finger of a user in combination with a display unit for displaying a switch operation screen with a superposed outline of a touching finger image. The outline image of the touching finger is derived from imaging the touching finger actually touching the separately positioned touch panel for providing a no-lookaway operability of the switch operation screen on the touch panel. 
         [0004]    The disclosure in Japanese patent document JP-A-H07-319623 improves user operability for indicating the button position in the switch operation screen by having the transparent sheet on the touch panel. However, when menus in the switch operation screen is hierarchically structured and variably arranged for controlling, for example, a navigation system, having plural transparent sheets for accommodating respective menus is difficult. 
         [0005]    Further, the disclosure in Japanese patent document JP-A-H10-269012 not only requires the protrusion on the surface of the touch panel, but also requires an associated operation of the touch panel and the switch operation screen due to its separate positioning of the display unit away from the touch panel. In addition, a flat surface of the touch panel without any positioning structure for the touching finger requires user&#39;s look and attention distracted away from a traveling direction of a vehicle, thereby deteriorating the operability of the touch panel. 
       SUMMARY OF THE INVENTION 
       [0006]    In view of the above and other problems, the present invention provides an input operation system that provides an improved operability for a user who uses a touch panel for controlling vehicular devices in a vehicle. 
         [0007]    In one aspect of the present invention, the input operation system for use in a vehicle includes a touch panel that senses a touching finger of a user, an imaging unit that images the touch panel, an outline extraction unit that extracts an outline image of the touching finger of the user based on an image of the touch panel, an image generation unit that generates a composite image by superposing the outline image of the touching finger extracted by the outline extraction unit on a switch operation screen, and a display control unit that displays the composite image generated by the image generation unit on a display panel. The touch panel of the input operation system has a touch sensitive surface having a protrusion disposed thereon, and the image generation unit generates the composite image by superposing the outline image of the touching finger on the switch operation screen that is backed by an image of the protrusion. In this manner, the protrusion on the surface of the touch panel is displayed as a background of the switch operation screen, thereby enabling the user to intuitively position the touching finger relative to a menu item of the switch operation screen without looking at the touch panel for an improved operability 
         [0008]    In another aspect of the present invention, the touch panel is automatically lit up by a backlight after a certain period of out-of-contact condition with a vehicular device such as a steering wheel or the like, thereby enabling the user to easily located the touch panel, based on an assistance of an operation detection unit and a lamp control unit for detecting the condition and controlling the backlight. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    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 which: 
           [0010]      FIG. 1  shows a block diagram of an input operation system in an embodiment of the present disclosure; 
           [0011]      FIGS. 2A and 2B  show illustrations of a touch panel of the input operation system; 
           [0012]      FIGS. 3A and 3B  show illustrations of the touch panel under control of a user&#39;s hand and an outline image superposed on a switch operation screen; 
           [0013]      FIGS. 4A and 4B  show illustrations of the touch panel with markers formed thereon; 
           [0014]      FIG. 5  shows a block diagram of the input operation system in another embodiment of the present disclosure; and 
           [0015]      FIG. 6  shows a flowchart of a control process of the input operation system in the another embodiment of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    Embodiments of the present invention will now be described with reference to the accompanying the drawings. 
         [0017]    A first embodiment of an input operation system  1  in the present disclosure is described with reference to  FIGS. 1 to 4B . The input operation system  1  is for use in a vehicle. The system  1  includes a touch switch  2 , a camera  3 , a control unit  4 , a display  5 , and a navigation unit  6 . 
         [0018]    The touch switch  2  includes a touch panel  7  for sensing a touching finger of a user, and a backlight  8  for lighting the touch panel  7 . The touch switch  2  is, for example, disposed on a center console or the like for an access by the user in a driving position with his/her left hand without releasing a right hand from a steering wheel. When the touch switch  2  is sensing the touching finger, the switch  2  outputs, to the control unit  4 , position coordinates that represents a position of the touching finger on the touch panel  7 . In this case, a sensing surface  7   a  of the touch panel  7  has a logotype of DENSO formed thereon as shown in  FIG. 2A . The logotype of ‘D’‘E’‘N’‘S’‘O’ is formed in a protruding manner on the surface  7   a , and respective letters of ‘D’  9 , ‘E’  10 , ‘N’  11 , ‘S’  12 , ‘O’  13  (protrusions  9 - 13 ) have a predetermined protrusion amount that does not obstruct smooth transitional movement of the touching finger on the surface  7   a.    
         [0019]    The camera  3  is a CCD camera, CMOS camera or the like in the present embodiment, and is disposed on a roof in the vehicle, a back of an instrument panel/a backlight  8  or the like. In this manner, the camera  3  images an entire area of the touch panel  7 , and outputs image data to the control unit  4 . The camera  3  may also be an infrared camera or the like. 
         [0020]    The display  5  is, for example, a liquid crystal display positioned in a normal forward view of a driver, and displays a composite image that is inputted from the control unit  4 . The size of the display  5  is preferably the same as the size of the touch panel  7 . The navigation unit  6  outputs a switch operation screen such as a menu screen, a destination setting screen, a search screen or the like to the control unit  4 , and performs an operation according to a switch control signal from the control unit  4  when the switch control signal is provided. 
         [0021]    The control unit  4  includes a CPU, a RAM, a ROM and other components, and the respective components perform their own function for rendering functions of an outline extraction processing module, a touch detection processing module, a composite image generation processing module, and a display control processing module. In this manner, the control unit  4  controls an entire operation of the input operation system  1 . More practically, the control unit  4  executes the outline extraction processing module upon having an input of the image data from the camera  3 , and extracts an outline of the touching finger of the user&#39;s hand based on the image of the user&#39;s hand. The image of the touching finger of the user&#39;s hand is processed by using, for example, Chromakey process. In this case, the surface color of the touch panel  7  is set to have the color of blue as a complementary color of skin, and the backlight  8  lights the touch panel  7 . In this manner, an influence of ambient light is decreased. 
         [0022]    The control unit  4  executes the touch detection processing module upon having an input of the position coordinates of the touching finger from the touch switch  7  for detecting a touching position of the user&#39;s hand. Further, the control unit  4  executes the composite image generation module for generating a composite image of the switch operation screen by having the outline image of the touching finger superposed on the switch operation screen with the DENSO logo background. That is, the composite image displays the positions of the protrusions  9 - 13  on the surface  7   a  of the touch panel  7  as a background image of the switch operation screen. Then, the control unit  4  executes the display control processing module to display the composite image on the display  5  as shown in  FIG. 2B . In this case, the positions (i.e., the coordinates) of the protrusions  9 - 13  of the DENSO logo in the touch panel  7  are substantially same as the positions (i.e., the coordinates) of a display position of the DENSO logo on the display  5 . 
         [0023]    When the protrusions  9 - 13  on the surface  7   a  of the touch panel  7  are displayed as the background image of the switch operation screen, the user is enabled to have a tactile feedback from the touching finger on the touch panel  7  without actually looking at the touch panel  7  as shown in  FIGS. 3A and 3B . More practically, the DENSO logo in the background image provides the user with a clue for positioning the touching finger at a right controlling position of respective menu items on the switch operation screen relative to the position of protrusions  9 - 13  formed on the surface  7   a  of the touch panel  7 . 
         [0024]    The protrusions  9 - 13  formed on the surface  7   a  of the touch panel  7  may be replaced with marking protrusions  14 - 16  of a star, a disk, and a square as shown in  FIG. 4A . In this case, the background image of the switch operation screen in the composite image is changed to the background image with corresponding shapes of the marking protrusions  14 - 16  as shown in  FIG. 4B . 
         [0025]    Further, the positions of the protrusions  9 - 16  in the image derived from the camera  3  may be utilized for accurately positioning the outline image of the user&#39;s hand in the composite image based on an analysis that compares the positions of the protrusions  9 - 16  in the image data from the camera  3  with the positions of the protrusions  9 - 16  in the composite image outputted to the display  5 . In this case, the colors of the protrusions  9 - 16  may be changed from the surface color of the touch panel  7  for securely extracting the positions of the protrusions  9 - 16 . 
         [0026]    The advantage of the input operation system  1  in the present embodiment is summarized in the following. That is, the input operation system  1  for use in the vehicle has the protrusions  9 - 16  on the surface  7   a  of the touch panel  7  in association with the protrusion-marked background image of the switch operation screen in the composite image, thereby providing the user with an improved operability based on an intuitive tactile feedback from the touching finger for positioning respective menu items in the touch panel  7  without a glance. Further, the protrusions  9 - 16  formed on the surface  7   a  of the touch panel  7  provides an aesthetic improvement by being in an industrially and ergonomically reasonable shape. 
         [0027]    A second embodiment of the present disclosure is described with reference to  FIGS. 5 and 6 . The description of the second embodiment is mainly focused to the difference of the second embodiment relative to the first embodiment. An input operation system  21  in the present embodiment includes a touch switch  22 , a camera  23 , a control unit  24 , a display  25 , and a navigation unit  26 . 
         [0028]    The touch switch  22  includes a touch panel  27  and a backlight  28 , and outputs to the control unit  24  an operation detection signal that represents either of an in-contact condition or an out-of-contact condition of the touching finger of the user with the touch panel  27 . The touch panel  27  also outputs contact position coordinates of the touching finger to the control unit  24  when the touching finger is touching the touch panel  27 . The touch switch  22  lights itself by the backlight  28  according to a lamp control signal upon having an input of the lamp control signal from the control unit  24 . 
         [0029]    A steering wheel  29  for steering the vehicle has an operation detection sensor  30  for detecting an in-contact condition and an out-of-contact condition of the touching finger with the steering wheel  29 . The operation detection sensor  30  outputs an operation detection signal that represents respective contact conditions of the touching finger of the user with the steering wheel  29  to the control unit  24 . 
         [0030]    The control unit  24  executes a steering operation detection module, a touch panel operation detection module, and a lamp control module beside executing other modules described in the first embodiment. The control unit  24  determines whether the touching finger of the user is in the in-contact or the out-of-contact condition with the steering wheel  29  by executing the steering operation detection module for analyzing the operation detection signal from the operation detection sensor  30 , and also determines whether the touching finger of the user is in the in-contact or the out-of-contact condition with the touch panel  22  by executing the touch panel operation detection module for analyzing the operation detection signal from the touch switch  22 . Further, the control unit  24  controls lighting operation of the backlight  28  by executing the backlight control module. 
         [0031]    A control process of the input operation system  21  in the present embodiment is described with reference to a flowchart in  FIG. 6 . 
         [0032]    The control unit  24  determines whether the touching finger of the user has lost contact with the steering wheel  29  in step S 1 , and start a clock to measure a first lapse time in step S 2  when the user is out of contact with the steering wheel  29  is detected (step S 1 :YES) based on the operation detection signal from the detection sensor  30 . Then, in step S 3 , whether a preset first lapse time has passed is determined, and whether the touching finger of the user is touching the steering wheel  29  again is determined in step S 4 . 
         [0033]    When the control unit  24  detects that the preset first lapse time has passed before detecting the contact of the touching finger of the user with the steering wheel  29  (step S 3 :YES), that is, when the out-of-contact condition of the touching finger with the steering wheel  29  has exceeded the preset first lapse time, the control unit  24  outputs the lamp control signal to the touch switch  22  for turning on the backlight  28  to a normal level of brightness in step S 5 . Then, the control unit  24  starts the clock to measure a second and third lapse time in steps S 6  and S 7 , and determines whether the touching finger has contacted the touch panel  27  in step S 8  as well as determines whether the preset second lapse time has passed in step S 9 . In this case, the present third lapse time is configured to be longer than the preset second lapse time. 
         [0034]    When the control unit  24  detects that the preset second lapse time has passed before detecting the contact of the touching finger of the user with the touch panel  27  (step S 8 :YES), that is, when the out-of-contact condition of the touching finger with the touch panel  27  after turning-on of the backlight  28  in the normal level of brightness has exceeded the preset second lapse time, the control unit  24  determines whether the brightness of the backlight  28  has reached the maximum level in step S 10 , and increases the brightness of the backlight  28  by one level in step S 11  upon detecting that the brightness of the backlight  28  has not reached the maximum level (step S 10 :NO). Then, the control unit  24  resumes measurement of the second lapse time in step S 12 , and returns to step S 8  for continuing the control process. 
         [0035]    When the control unit  24  detects that the touching finger of the user has contacted the touch panel  27  before the elapse of the preset second lapse time (step S 8 :YES), that is, when the user has contacted the touch panel  27  with the touching finger before the elapse of the preset second time after turning-on of the backlight  28  in the normal level of brightness, the control unit determines the brightness level of backlight  28  at the time of the detection of the contact with the touch panel in step S 13 . When the brightness level of the backlight  28  is not in the normal level (step S 13 :NO), the control unit  24  puts the brightness level of the backlight  28  back to the normal level in step S 14 . 
         [0036]    Then, the control unit  24  determines whether the touching finger of the user has lost contact with the touch panel  27  in step S 15  and whether the touching finger of the user has contacted with the steering wheel in step S 16 , and concludes the input system control process with turning-off of the backlight  28  in step S 17  after having a determination result in step S 15  that the user has lost contact with the touch panel  17  (step S 15 :YES) and a determination result in step S 16  that the user has contacted the touching finger with the steering wheel  29  (step S 16 :YES). 
         [0037]    The advantage of the second embodiment of the input operation system  21  is summarized in the following. That is, the operation system  21  lights the touch panel  27  with the backlight  28  lit in the normal brightness level after the preset first lapse time of the loss of the contact of the touching finger with the steering wheel  29 , thereby providing an improved operability of the touch panel in terms of positioning the touch panel  27  without causing a look-away from a front direction of the vehicle, or with a minimum amount of a look-away from the front direction. Further, the brightness of the backlight  28  is configured to be back to the normal level after the preset second lapse time of the out-of-contact condition of the touching finger with the touch panel  27  for suppressing unnecessary battery consumption. Furthermore, unnecessary battery consumption is further suppressed by having the preset third lapse time for turning off the backlight upon detecting the out-of-contact condition of the touching finger with the touch panel or upon detecting the combined conditions of the loss-of-contact with the touch panel  27  and the contact with the steering wheel  29  by the touching finger. 
         [0038]    Although the present invention has been fully described in connection with the preferred embodiment thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art. 
         [0039]    For example, the control units  1  and  21 , the displays  5  and  25 , the navigation units  6  and  26  may be integrally formed as a navigation system of the vehicle. 
         [0040]    The logos and protrusions in the first embodiment may have other forms and other quality. 
         [0041]    The operation detection sensor may be provided on a shift knob in the second embodiment, and the backlight control may be provided based on the in- and out-of-contact conditions of the touching finger with the shift knob in combination with the contact conditions with the steering wheel. 
         [0042]    Such changes and modifications are to be understood as being within the scope of the present invention as defined by the appended claims.