Abstract:
The present invention relates to a vehicle navigation system that uses a portable information terminal. The navigation system displays route guidance information by receiving GPS satellite radio waves, and includes a navigation unit that generates route guidance information, a meter panel of a meter unit, which displays only part of the route guidance information, and a display panel of the navigation unit, which displays every selected item of the route guidance information. The meter panel of the meter unit is disposed within the visual field of the driver when in driving the vehicle. On the other hand, the display panel of the navigation unit is disposed outside of the visual field of the driver when in driving the vehicle. The resulting configuration provides a vehicle navigation system that can provide the driver with the minimum necessary information when driving the vehicle, along with additional detailed information when needed, combined in a system that affords excellent operability.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
         [0001]    The present application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2001-083182, filed on Mar. 22, 2001, the entire contents thereof are hereby incorporated by reference.  
         BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to a vehicle navigation system. More particularly, the present invention relates to a vehicle navigation system that uses a portable information terminal (hereinafter, to be referred to as “PDA”).  
           [0004]    2. Description of Background Art  
           [0005]    In recent years, many vehicles use vehicle navigation systems that guide the drivers to their goals on a map on which the current position of the vehicle is displayed respectively. Such navigation systems are realized by combining a global positioning system (GPS) and map information.  
           [0006]    Conventionally, vehicle navigation systems have been developed mainly for four-wheel cars. In recent years, however, it is under examination whether or not it is possible to install these systems also in small cars such as auto-bicycles, irregular ground buggies, etc. For example, the official gazette of Published Unexamined Patent Application No. 11-321754 discloses an auto-bicycle in which a navigation system is installed.  
           [0007]    Conventional navigation systems have employed large display screens so as to provide the drivers with as much information as possible. For such small vehicles as auto-bicycles, etc., therefore, it has been difficult to secure a space for mounting such a display panel in the visual field of the driver.  
           [0008]    In order to solve such the technical problem, the official gazette of Published Unexamined Patent Application No. 11-14391 or No. 10-122885 proposes a method that displays only the minimum necessary information, such as a direction of and a distance to a goal, in a small area of the vehicle meter panel as in a small portable GPS unit.  
           [0009]    According to the above-described conventional techniques, operation switches must be disposed in a limited area on or around the meter panel, making the units difficult to operate. This, then, presents another problem with conventional devices.  
           [0010]    In addition, because it is difficult to provide the driver with enough information on the above-described rough display, the navigation system must be able to prepare a dedicated map on which longitude and latitude lines are described in detail, and further, must also provide a portable GPS unit to let the driver know his/her current position with accuracy.  
           [0011]    Under such circumstances, it is an object of the present invention to provide a vehicle navigation system with excellent operability that can provide the driver with the minimum necessary route guidance information when driving the vehicle, thus solving the conventional technical problems described above.  
         SUMMARY AND OBJECTS OF THE INVENTION  
         [0012]    In order to achieve the above object, the vehicle navigation system of the present invention that displays route guidance information by receiving GPS satellite radio waves is provided with following means:  
           [0013]    (1) A first display block that displays only part of route guidance information, and a second display block that displays every selected item of the route guidance information.  
           [0014]    (2) A first display block that displays the route guidance information roughly, and a second display block that displays the route guidance information in detail.  
           [0015]    According to the features described in (1) and (2), the first display block displays only indispensable information selected from among the mass of route guidance information items, while the second display block displays other information items and detailed information. As a result, the space of the first display block can be minimized. Consequently, the first display block can be disposed in the visual field of the driver with no obstacle between them, and the second display block can be formed so as to display detailed information that will overflow the first display block.  
           [0016]    Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:  
         [0018]    [0018]FIG. 1 is a perspective view of an astride type buggy car used for irregular grounds, with a vehicle navigation system of the present invention installed therein;  
         [0019]    [0019]FIG. 2 is a navigation box with its cover opened;  
         [0020]    [0020]FIG. 3 is a block diagram of a navigation system;  
         [0021]    [0021]FIG. 4 is a top view of a display panel in a configuration;  
         [0022]    [0022]FIG. 5 is a display example of a meter panel;  
         [0023]    [0023]FIG. 6 is a display example (title screen) of a display panel of a navigation unit;  
         [0024]    [0024]FIG. 7 is a display example (map guidance screen) of the display panel of the navigation unit;  
         [0025]    [0025]FIG. 8 is a display example (satellite location screen) of the navigation unit;  
         [0026]    [0026]FIG. 9 is a display example (latitude/longitude display screen) of the navigation unit;  
         [0027]    [0027]FIG. 10 is a display example (guidance with arrows display screen) of the navigation unit;  
         [0028]    [0028]FIG. 11 is a display example (framed map guidance screen) of the navigation unit;  
         [0029]    [0029]FIG. 12 is a side view of an auto-bicycle in which the navigation system of the present invention is installed;  
         [0030]    [0030]FIG. 13 is a rear front view of the auto-bicycle shown in FIG. 12;  
         [0031]    [0031]FIG. 14 is a top view of a meter panel of the auto-bicycle shown in FIG. 12;  
         [0032]    [0032]FIG. 15 is a display example (radio operation screen) of the sub-panel;  
         [0033]    [0033]FIG. 16 is a display example (audio operation screen) of the sub-panel;  
         [0034]    [0034]FIG. 17 is a display example (warning screen) of the sub-panel; and  
         [0035]    [0035]FIG. 18 is a display example (warning screen) of the sub-panel. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0036]    Hereinafter, an example of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows a perspective view of an astride type buggy car  100  used for irregular grounds. The vehicle navigation system of the present invention is installed in the buggy car  100 . The buggy car  100  provided with large-diameter wheels  101 , an under-cover  102 , a four-wheel driving mechanism, etc., is excellent in hill-climbing and running properties.  
         [0037]    A meter unit  107  is disposed in the center of handlebars  106  and a helical GPS receiving antenna  103  is erected from the top of the meter unit  107 . Since the astride type buggy car  100  is often used on irregular grounds, the car  100  changes its posture bewilderingly when in a running state. For this reason, a helical receiving antenna  103  with a wide orientation is employed. With a helical receiving antenna, GPS radio waves can be received satisfactorily regardless of the posture changes of the vehicle.  
         [0038]    A front carrier  104  and a rear carrier  108  are disposed at the front side and at the rear side of the car  100  respectively. A navigation box  105  (to be described later) is mounted in the backward upper portion of the front carrier  104 .  
         [0039]    [0039]FIG. 2 shows a navigation box  105  with its cover  1051  opened. A cushion material (not shown) is put up all over the inner walls of the box  105  and a navigation unit  1  is housed in the box  105 . This navigation unit  1  is a portable information terminal, such as a portable PDA (Personal Digital Assistant), a lap-top PC, or the like in which a navigation program is downloaded.  
         [0040]    A relay unit  2  is connected to the navigation box  105 . The relay unit  2  includes a multiple-pole connector  24  at one end. The connector  24  is connected/disconnected to/from an I/O port  17  of the navigation unit  1 . The navigation unit  1  can be removed from the navigation box  105  by disconnecting the connector  24  of the relay unit  2  from the I/O port  17  and unfastening a predetermined fastening mechanism.  
         [0041]    Consequently, the navigation unit  1  can be connected to the connector  24  so as to be used as a navigation system when in driving. Alternatively, the navigation unit  1  can be disconnected from the connector  24  so as to be used as a normal portable information terminal in other occasions.  
         [0042]    Furthermore, when this portable information terminal is combined with a handy GPS or GPS smart antenna, or when a GPS-installed PDA is employed as the navigation unit  1 , the terminal can be used as a small GPS unit.  
         [0043]    The navigation box  105  should preferably have a size large enough to house a PDA, a lap-top PC, and A4/B5-size regular files.  
         [0044]    In this example, the navigation unit  1  is housed in the navigation box  105  so that it is secure from robbery. Also, when appropriate, however, the unit can be removed from the box and used as a portable unit. The navigation unit  1  is also usable as a multi-function information terminal. As such, it can be used to store address lists, and dictionaries, etc.  
         [0045]    Because an electrical junction between the navigation unit  1  and the navigation box  105  is located in the box  105 , it is protected from contamination and damages by rain, wind, dust, and other elements.  
         [0046]    [0046]FIG. 3 shows a block diagram of a navigation system installed in the astride type buggy car  100 . The same reference numerals are given to the same components as those described above.  
         [0047]    The navigation system in this example includes a portable navigation unit  1  housed in the navigation box  105 ; a meter panel  3  that roughly displays part of route guidance information obtained from the navigation system; a relay unit  2  for connecting the navigation unit  1  to the meter panel  3 ; and a GPS receiver  4  that receives GPS radio waves via a receiving antenna  103  and translates received waves to electrical signals.  
         [0048]    In the navigation unit  1 , the navigation program storage  13  stores a navigation program. A CPU  10  executes the navigation program under the control of a control program stored in a ROM  11 . A RAM  12  is used as a work area of the CPU  10 .  
         [0049]    A display controller  15  includes a rough display controller  15   a  and a map display controller  15   b . The meter panel  3  of the meter unit  107  receives only the minimum necessary rough information, such as a direction of and a distance to each goal among the various kinds of route guidance information items obtained in accordance with the execution of the navigation program via an interface  14 , the I/O port  17 , and the relay unit  2 .  
         [0050]    The map information controller  15   b  displays all the selected route guidance information items, such as detailed map information, etc., obtained in accordance with the execution of the navigation program.  
         [0051]    The relay unit  2  includes connection terminals for a digital camera  22  and a portable phone/PHS  23 . The relay unit  2  functions as a data path between the navigation unit  1  and the meter panel 3/GPS receiver  4 . Relay unit  2  also functions to transfer image data photographed by the digital camera  22  to the navigation unit, and further, functions to transfer data collected by the navigation unit  1  from a portable phone/PHS  23  to a predetermined base station through radio communications.  
         [0052]    [0052]FIG. 4 shows a top view of the meter panel  3  of the meter unit  107  in a configuration. The meter panel  3  includes a speed display area  61 ; a running distance display area  63  that functions as both of an odometer and a trip meter; a sensitivity display area  62  used to display the receiving status of the GPS radio waves; and a direction display area  64  used to display a direction of a relay point (way point: WP) roughly in 16 points. The running distance display area  63  displays a rough distance up to a way point WP exclusively from the running distance.  
         [0053]    The meter panel  3  further includes a “MODE” switch  65  used to switch among operation modes of the navigation system; a “WPT” switch  66  used to register the current position of the subject car as a new way point WP; and an “INC” switch  67   a  and a “DEC” switch  67   b  used to select a desired WP from among a plurality of registered WPs. Other display items are not necessary to understand the present invention, so the description for them will be omitted here.  
         [0054]    When the navigation system in such a configuration is powered, the navigation program in the navigation unit  1  is started up. The navigation system then begins route guidance. When in a running state, the meter unit  107  displays the minimum necessary route guidance information such as the direction of and the distance to a currently selected way point WP. The meter unit  107  also receives sensitivity status of the GPS radio waves among various kinds of guidance information items, received from the display controller  15  and the rough display controller  15   a.    
         [0055]    As shown in FIG. 5, meter panel  3  of the meter unit  107  displays the receiving sensitivity status in the sensitivity display area  62 , an identification number “1” of the way point WP and a distance “1,23 (miles)” up to the way point WP 1  in the running distance display area  63 , and a direction of the way point WP 1  in the direction display area  64  respectively, according to the received information.  
         [0056]    On the other hand, when the driver wants to refer to further detailed map information, the driver can stop the car and open the navigation box  105  to start up the detailed display of the navigation unit  1 .  
         [0057]    The display panel  16  of the navigation unit  1  displays a title screen as shown in FIG. 6, then a map navigation screen with a running trace as shown in FIG. 7. An arrow N 8  in FIG. 6 denotes a position and running direction of the subject car and the running trace is displayed with a dot N 9 .  
         [0058]    The display panel  16  can also display a satellite location map as shown in FIG. 8, as well as both longitude and latitude lines for denoting the position of the car as shown in FIG. 9 in accordance with the driver&#39;s operation of the navigation unit  1 .  
         [0059]    The route guidance that uses way points as described above will therefore be especially effective when the buggy car  100  is dispatched to a disaster-stricken site for state checking, or to a recovery works, for example.  
         [0060]    Often, rescue members, etc. dispatched to a disaster-stricken site/recovery working site may not be familiar with geographical information of the area. In addition, when the disaster is a serious one, the scene might be changed completely, making it difficult to identify the target position accurately. At such a disaster-stricken site, the rescue staff may be required to take an unavoidable detour route on the way back, since the outward traffic may be blocked.  
         [0061]    Even in such a case, on the way back the driver will be able to refer to the direction display area  64  and the running distance display area  63  on the meter panel  3  to easily recognize both the distance to, and the direction of, each way point registered on the way forward. The driver can thus return to each way point on the way back, then to the starting point via the detour route.  
         [0062]    Furthermore, when it is difficult for the driver to go to a way point displayed in the direction display area  64  of the meter panel  3 , the driver can refer to the detailed map information displayed on the display panel  16  of the navigation unit  1 . With this capability, the driver can examine detour routes to each way point, and determine the way back to the starting point.  
         [0063]    On the other hand, when the driver removes the navigation unit  1  from the navigation box  105  and carries it with him/her, either a guidance screen with arrows as shown in FIG. 10, or a framed map guidance screen as shown in FIG. 11, can be displayed.  
         [0064]    The guidance screen with arrows shown in FIG. 10 displays an arrow N 1  and a dot mark N 2  for denoting the direction of a way point; a way point name N 3 ; a long-range distance number N 4  up to the way point N 4 ; and a graphic item N 5  that displays a distance up to the way point N 4  as a bar graph. The framed map guidance screen shown in FIG. 11 displays a large arrow N 6  for both way point shape and moving direction and a small arrow N 7  for the direction of each way point.  
         [0065]    When a general-purpose portable PDA used as the navigation unit  1  is connected to the navigation system removably and used for the irregular ground buggy car  100 , the system will be used more effectively at disaster-stricken sites/recovery working sites.  
         [0066]    Generally, when the buggy car  100  is sent out to a disaster-stricken site, image data of the site photographed by the digital camera  22  is transferred to the navigation unit  1  via the relay unit  2 . The navigation unit  1  transfers image data with position and date/time information of the photographed site added thereto to the headquarters, etc., from the portable phone/PHS  23  by using its own navigation function. Consequently, the necessary information can be recognized quickly and in detail.  
         [0067]    Information related to the photographing date and time can be added to the image data so that the trace data stored in the navigation system, and thus the date-and-time information can be collated with each other. This feature is useful, for instance, in identifying the photographing point.  
         [0068]    In this example, the navigation unit  1  can be removed from the vehicle body and carried by a rescue member. As such, it is possible to drive the buggy car  100  up to a place close to the target site, and remove the navigation unit  1  from the car  100 , so that the rescue member can carry the unit  1  with him/her to go to the site. The removed navigation unit  1  may be connected to a general-purpose PDA and a handy GPS/GPS smart antenna, or to a GPS-installed PDA so that the navigation unit  1  is provided with all the navigation functions. The user can thus go forward under the guidance of the navigation system and send the disaster-stricken site image photographed by the digital camera  22  to the headquarters as in the case described above.  
         [0069]    While the navigation box  105  is mounted on the front carrier  104  of the vehicle  100  in the above example, the navigation box  105  may be mounted on the rear carrier  108  or around the driver&#39;s seat.  
         [0070]    In this example, the system is provided with two display panels that share the main functions of the navigation system. The meter panel  3  of the vehicle displays only the minimum necessary information, such as the direction of and the direction to each relay point (WP), and the GPS wave receiving sensitivity status for the driver. It is thus possible to reduce the display space. On the other hand, because the display panel  16  of the navigation unit  1  housed in the navigation box  105  can display detailed map information, the driver can obtain both of rough and detailed information items.  
         [0071]    Furthermore, according to this example, the navigation unit  1  can be removed from the vehicle, so that the navigation unit  1  can be used effectively.  
         [0072]    [0072]FIG. 12 shows a side view of an auto-bicycle  200  in which the navigation system of the present invention is installed.  
         [0073]    The vehicle in this example includes a horizontally opposed 6-cylinder engine  201 . An exhaust manifold  211  is led out from the engine  201  to the rear and this exhaust manifold  211  is connected to a muffler  212 .  
         [0074]    The front wheel FW is supported rotationally at the lower end of a front fork  202 . The front part of the vehicle is covered by a front fairing (cowl)  203  and a wind screen  204  is provided on the top surface. The driver&#39;s seat  206  and a fellow passenger seat  207  are disposed in the rear of a fuel tank  205 .  
         [0075]    The fellow passenger seat  207  with a back rest  208  is united with the driver&#39;s seat  206 . A rear trunk  210  is provided at the rear side of the back rest  208 . Side trunks  210 L and  210 R are provided in the lower portion of the rear trunk  210  and at the both sides of the rear wheels RW. In this example, the navigation unit  1  is housed in the rear trunk  210 .  
         [0076]    [0076]FIG. 13 shows a rear front view of the vehicle  200 . In FIG. 13, the same reference numerals are given to the same and equivalent items described above.  
         [0077]    In this vehicle, the cover of the trunk  210  is opened upward and the covers  220 L and  220 R of the side trunks  210 L and  210 R are opened to the side respectively. Each of the trunks  210 ,  210 L, and  210 R are locked/unlocked by turning an engine key inserted in a key cylinder  221  located at the trunk  210 .  
         [0078]    Three opening/closing levers  23 L,  23 C, and  23 R are provided in the lower portion of the rear trunk  210 . Each of those levers  23 L,  23 C, and  23 R is operated after the rear trunk  210  is unlocked so as to open the cover  220 L of the side trunk  210 L, the cover  220  of the rear trunk  210 , and the cover  220 R of the side trunk  210 R.  
         [0079]    [0079]FIG. 14 shows a top view of the meter panel  230  of the auto-bicycle  200  from the driver&#39;s seat  206  side. A GPS rough display block  230   a  is united with the meter panel  230  in the lower portion of the panel  230 .  
         [0080]    A speed meter  110  is provided in the center of the meter panel  230  and a tachometer  120  is provided at the left side of the speed meter. And, a fuel gauge  130  and an engine temperature gauge  140  are disposed at the right of the speed meter  110  respectively. Winker indicators  170  and  171  are disposed at both sides above the speed meter  110 .  
         [0081]    At the speed meter  110  are disposed an oil indicator  111 , a security indicator  112 , a high beam indicator light  113 , a light volume sensor  114  for the meter  110 , an ABS (Anti-lock Braking System) warning light  115 , and an FI (fuel injection) warning light  116  together. An auto-cruising indicator light  131  and an auto-cruising set indicator light  132 , a transmission reverse indicator light  141 , a neutral indicator light  142 , and an over-drive indicator light  143  are disposed in a vertical line between the fuel indicator  130  and the engine temperature gauge  140 .  
         [0082]    Furthermore, a light blink indicator  144  is disposed at the left side of each indicator light of the transmission and a fuel empty indicator  145  is disposed at the right side. A clock  121  is disposed in the lower portion of the tachometer  120 .  
         [0083]    A sub-panel  160  is disposed in the center of the GPS rough display block  230   a  and the “WPT” switch, the “INC” switch, and the “DEC” are disposed in the lower portion of the block  230   a  just like the buggy car  100 .  
         [0084]    On the sub-panel  160  of the auto-bicycle  200 , the sensitivity display area  62  displays the receiving sensitivity status of the GPS radio waves, in a manner similar to that in the buggy car  100 . The direction display area  64  displays the direction of a way point, and the running distance display area  63  displays “1” as an identification number of the way point and “1.23 (miles)” as the distance up to the way point WP respectively. When the navigation system operation is disabled, the sub-panel  160  displays the radio operation screen shown in FIG. 15, or alternatively, the audio operation screen shown in FIG. 16.  
         [0085]    In this example, a sensor monitors whether or not each trunk cover is opened/closed. For example, when all the covers  220 ,  220 L, and  220 R are kept opened, the warning screen shown in FIG. 1 is displayed. When only the cover  220 R of the right side trunk  210 R is kept opened, the warning screen shown in FIG. 18 is displayed. Each warning screen can break into the display of the sub-panel  160  whether the navigation system is operating or not.  
         [0086]    In this example, when the car  100  passes a preset way point, the driver can trace the predetermined running route simply by referring to the sub-panel  160 . When passing a non-preset way point, however, the driver is requested to refer to the navigation unit  1  housed in the rear trunk  220  to obtain detailed information. Also in this case, the driver can enjoy comfortable touring without losing his/her way.  
         [0087]    Furthermore, when image data photographed by the digital camera  22  during running is transferred to the navigation unit  1  and stored so as to be related to the position information, it becomes easier to arrange these image data in order at a later time.  
         [0088]    As described above, also in this example, the system is provided with two display panels that share the main functions of the navigation system so that the sub-panel  160  of the vehicle displays only the minimum necessary information of the driver, thereby the display space can be minimized. On the other hand, the display panel  16  of the navigation unit  1  displays detailed map information, so that the driver can obtain both of rough and detailed information.  
         [0089]    In each of the above examples, the present invention has applied to the buggy car  100  and the large auto-bicycle  200 . However, the present invention may also apply to smaller vehicles, such as scooters, so long as the vehicle is provided with two display panels, one display panel being disposed in the driver&#39;s visual field, and the other being housed in the navigation box.  
         [0090]    When the present invention applies to a scooter, the navigation unit  1  may be housed in a housing space secured under the driver&#39;s seat, which is also used as the cover of the driver&#39;s seat or in a pocket equivalent to the navigation box, provided at the driver&#39;s seat side in the leg shield block. Otherwise, the navigation unit  1  may be housed in a glove compartment disposed between the cowling extended from the front to the rear of the vehicle and the car body.  
         [0091]    According to the present invention, the first display block space can be reduced. This is the result of the system having two display blocks that share the main functions of the navigation system, wherein the first display block displays only the minimum necessary information of the driver during running, and the second display block displays other and detailed information. Consequently, the first display block can be disposed in the visual field of the driver with no obstacles therebetween, and the second display block can display detailed information that will overflow the first display block.  
         [0092]    The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.