Patent Publication Number: US-2009234575-A1

Title: Navigation device and method

Description:
BACKGROUND 
     1. Field of the Invention 
     The present invention relates to satellite navigation devices. 
     2. Description of Related Art 
     A navigation device is an electronic product which combines a positioning capability, such as Global Positioning System (GPS), and navigation functions. Conventionally, a navigation device will search for an optimized route between a starting location and a destination point using mapping data. When a route including destination information is requested, a current location of the navigation device is computed according to the GPS satellite signals. Then, the optimized route to the destination is selected according to the starting location and destination point of the mapping data. Finally, navigational information may be visually provided through a display screen. 
     Referring to  FIG. 3 , when a user driving a car reaches a crossroad  40 , and does not know how to go to destination  44 , he/she may input a route request to a navigation device. The navigation device shows a route from the crossroad  40  to the destination  44  labeled by a line  43  on an electronic map. However, the navigation device does not show the exact heading (orientation/positioning) of the car at the crossroad  42 . If the user is not familiar with the area, and does not know the orientation, the user may not know whether to turn left, right, go straight, or turn around. The problem also arises when the user is on a straight road and does not know whether or not to go straight ahead or turn around. 
     Therefore, an improved navigation device and method are needed to address the aforementioned deficiency and inadequacies. 
     SUMMARY 
     A navigation device includes a route generator, a travel log recorder, a traveled route generator, and a display module. The route generator is used for generating a route from a current position to a destination based on predetermined mapping data when receiving a route request. The travel log recorder is used for recording a traveled log of the navigation device before receiving the route request. The traveled route generator is configured for generating traveled route information according to the traveled log recorded in the travel log recorder when receiving the route request. The display module is used for displaying the route and the traveled route information simultaneously for guiding a user to the destination. A related navigation method is also provided. 
     Other advantages and novel features of the present invention will become more apparent from the following detailed description of preferred embodiment when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic block diagram of a navigation device in accordance with an exemplary embodiment. 
         FIG. 2  is a schematic diagram of an electronic map showing a route in accordance with an exemplary embodiment. 
         FIG. 3  is a schematic diagram of an electronic map showing a route in accordance with the related art. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Reference will now be made to the drawings to describe an exemplary embodiment of the present navigation device and method. 
     The navigation device records a traveled log before a route request is inputted. When the route request is inputted to the navigation device, the navigation device shows navigational information including the traveled log and a route to a destination simultaneously. Therefore, a better, clearer (more informed) navigational information with respect to the traveled log can be shown/displayed by the navigational device. 
     Referring to  FIG. 1 , a navigation device  20  includes a positioning module  22 , a storage module  23 , a display module  24 , a route generator  25 , an input module  26 , a travel log recorder  27 , and a traveled route generator  28 . The storage module  23  is used for storing mapping data. 
     The positioning module  22  is configured for receiving satellite positioning signals, and determining a current position of the navigation device  20  based on the satellite positioning signals. The satellite positioning signals may be supplied by the Global Positioning System (GPS), or the Global Navigation Satellite Systems (GNSS). Information of the current position of the navigation device  20  includes longitudinal and latitudinal values. 
     The input module  26  is used for receiving the route request. The route request includes information of the destination. The input module  26  may be a keyboard, a touchscreen, or a handwriting input device (such as a drawing tablet or a tablet-PC). 
     The route generator  25 , coupled to the positioning module  22 , the storage module  23 , and the input module  26 , is used for generating a route according to the mapping data, the current position, and the destination. 
     The travel log recorder  27  is configured for recording the traveled log of the navigation device  20 . In detail, the positioning module  22  generates a current position of the navigation device  20  in real time based on the satellite positioning signals, and the travel log recorder  27  records the current positions at that moment. In the exemplary embodiment, the travel log recorder  27  only keeps the latest traveled record over a predetermined time period. That is, only the traveled log recorded during the predetermined time period of the navigation device  20  is stored in the travel log recorder  27 . For example, last fifteen minutes. As a result, storage usage of the travel log recorder  27  is controlled and can be kept to a minimum. In other alternative embodiments, the travel log recorder  27  only keeps the latest traveled record over a predetermined distance, half a mile for example. 
     The traveled route generator  28  is configured for generating traveled route information according to the traveled log stored in the travel log recorder  27 . In the exemplary embodiment, the traveled route information includes a traveled direction up to the current position of the  20 . 
     The display module  24  is used for displaying the route to the destination and the traveled route information simultaneously to more clearly show the route to the destination. Referring to  FIG. 2 , in the exemplary embodiment, the requested route is shown as a line  53  on an electronic map displayed by the navigation device  20 . The current position  52  and the destination  54  are respectively illustrated as large dots. The traveled route information is shown as a line  51  with an arrowhead for indicating the traveled route up to the current position. Therefore, more clearly displaying a direction to advance to the destination  54  at a crossroad  50 . The traveled route information makes the navigation device  20  more usable. 
     In other embodiment, the traveled route information may only include a latest recorded trace of the navigation device  20 , the last 5 minutes for example, and the traveled route information may just be shown as a line different from the line  53  for indicating the route the navigation device traversed recently. 
     It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.