Patent Publication Number: US-2009228194-A1

Title: Navigation apparatus, data updating method, and data updating program

Description:
TECHNICAL FIELD 
     The present invention relates to a navigation apparatus mounted on vehicles, etc., a data updating method, and a data updating program. However, the present invention is not limited to the above navigation apparatus, the data updating method, and the data updating program. 
     BACKGROUND ART 
     Recently, for example, navigation systems equipped with a plurality of recording media (storage units) such as a DVD (Digital Versatile Disc) and a HD (Hard Disc) from which map data can be read are provided offering highly convenient navigation operation for users by accessing the storage units, which are optimal for reading necessary map data. 
     For example, such navigation systems are configured as follows. That is, when a target file of map data is read out in the navigation system, a priority flag is referred to. If the priority flag is set for DVD, the target file is read from the DVD and if the priority flag is set for HD, an HD management area is accessed to read the target file from the HD, provided that the target file is stored in the HD and the update date and time thereof are not old. On the other hand, if the target file is read from the DVD, the target file is stored in the HD after ensuring an available space in the HD. In this configuration, necessary map data can be read from a plurality of storage units and used for the navigation operation, and the optimal map data can be selectively used even during the navigation (see, for example, Patent Document 1). 
     This navigation system also determines the update date and time of the map data recorded in the plurality of the storage units and selectively accesses the storage unit having the map data with the latest determined update date and to read the corresponding map data. In this configuration, the most recent map data can be selectively utilized from among map data that are continuously updated having different recentness. 
     Patent Document 1: Japanese Patent Application Laid-Open Publication No. 2001-165675DISCLOSURE OF INVENTION 
     PROBLEM TO BE SOLVED BY THE INVENTION 
     However, in a navigation system of the above conventional technology, for example, when map data are updated, utilization of a navigation function must be stopped to update the data and an example of a problem is that the navigation function cannot be utilized until the updating of data has been completed for a portion of the data that is required to activate the navigation function. 
     For example, since data are updated by writing updated (new) data while non-updated (old) data are left in a storage unit and then deleting the old data after the data update is completed, a given amount of work area is necessary and an example of a problem is that it is difficult to reduce the required capacity of the storage unit. In this case, an example of a problem is that the control of the timing of deletion is troublesome when deleting the old data after the data update is completed. 
     MEANS FOR SOLVING PROBLEM 
     A navigation apparatus according to the invention of claim  1  includes a storage unit that stores, in a plurality of areas, data necessary for navigation operation; an acquiring unit that acquires the data from an external recording medium; a comparing/identifying unit that compares and identifies the data stored in the storage unit and the data acquired by the acquiring unit; an updating unit that controls, based on comparison/identification results of a comparison and an identification by the comparing/identifying unit, an update of the data in the plurality of areas of the storage unit; and a control unit that, at least while the updating unit is performing the update of the data, performs navigation operation utilizing data that are not being subjected to the update among the data stored in the storage unit and the data acquired by the acquiring unit. 
     Further, a data update method according to the invention of claim  5  includes a storing step of storing, in a plurality of areas, data necessary for navigation operation; an acquiring step of acquiring the data from an external recording medium; a comparing/identifying step of comparing and identifying the data stored in the storage unit and the data acquired by the acquiring unit; an updating step of controlling, based on comparison/identification results of a comparison and an identification by the comparing/identifying unit, an update of the data in the plurality of areas of the storage unit; and a control step of performing navigation operation utilizing data that are not being subjected to the update among the data stored in a storage unit and the data acquired at the acquiring step at least while the updating unit is performing the update of the data. 
     Moreover, a data update program according to the invention of claim  9  causes a computer to execute the date update method according to any one of claims  5  to  8 . 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a block diagram of an example of a functional configuration of a navigation apparatus according to an embodiment; 
         FIG. 2  is a flowchart of an example of a data updating process of the navigation apparatus according to the embodiment; 
         FIG. 3  is a block diagram of an example of the hardware configuration of the navigation apparatus according to the example; 
         FIG. 4  is a schematic view of the navigation operation process and a data update process of the navigation apparatus according to the example; 
         FIG. 5  is a flowchart of the data update process of the navigation apparatus according to the example of the present invention; 
         FIG. 6  is an explanatory view of an overview of the data update process of the navigation apparatus according to the example; 
         FIG. 7  is an explanatory view of an overview of the data update process of the navigation apparatus according to the example; 
         FIG. 8  is an explanatory view of an overview of the data update process of the navigation apparatus according to the example; 
         FIG. 9  is an explanatory view of an overview of the data update process of the navigation apparatus according to the example; 
         FIG. 10  is an explanatory view of the overview of the navigation operation of the navigation apparatus according to the example; 
         FIG. 11  is an explanatory view of the overview of the navigation operation of the navigation apparatus according to the example; 
         FIG. 12  is an explanatory view of the overview of the navigation operation of the navigation apparatus according to the example; and 
         FIG. 13  is an explanatory view of the overview of the navigation operation of the navigation apparatus according to the example. 
     
    
    
     EXPLANATIONS OF LETTERS OR NUMERALS 
     
         
         
           
               101  storage unit 
               102  acquiring unit 
               103  comparing/identifying unit 
               104  updating unit 
               105  control unit 
               106  output unit 
               302  ROM 
               303  RAM 
               304  HDD 
               305  HD 
               306  DVD drive 
               307  DVD 
               308  video/audio I/F 
               311  input I/F 
               314  communication I/F 
           
         
       
    
     BEST MODE(S) FOR CARRYING OUT THE INVENTION 
     With reference to the accompanying drawings, an exemplary embodiment of a navigation apparatus, a data updating method, and a data updating program according to the present invention is explained in detail. 
     Embodiment 
     (Functional Configuration of Navigation Apparatus) 
     Details of a navigation apparatus according to an embodiment of the present invention will be described.  FIG. 1  is a block diagram of an example of a functional configuration of the navigation apparatus according to the embodiment of the present invention. A shown in  FIG. 1 , the navigation apparatus is mounted on a moving object such as a vehicle (including four-wheel vehicles and two-wheel vehicles) and includes a storage unit  101 , an acquiring unit  102 , a comparing/identifying unit  103 , an updating unit  104 , and a control unit  105 , and an output unit  106  is further included. 
     The storage unit  101  stores, in a plurality of areas, data necessary for the navigation operation. Specifically, the data required for the navigation operation include map data and program data used with the navigation operation. The areas of the storage unit  101  is configured by a data area storing the map data and the program data and a user area storing user data related to the navigation operation, and the data area is may be further divided into a plurality of areas. 
     The acquiring unit  102  acquires the data required for the navigation operation from an external recording medium. The external recording medium is a recording medium removable from the navigation apparatus and specifically includes optical discs such as DVDs (Digital Versatile Disc) and CDs (Compact Disc). For example, PC cards and memory cards may be used for the external recording medium. 
     The comparing/identifying unit  103  compares and identifies the data required for the navigation operation stored in the storage unit  101  and the data required for the navigation operation acquired by the acquiring unit  102 . Specifically, the comparison and identification of the data by the comparing/identifying unit  103  are performed by comparing the update date/time and versions of the data in the areas of the storage unit  101  to identify the newer data. 
     The updating unit  104  controls the update of the data required for the navigation operation in the areas of the storage unit  101  based on the comparison/identification results of the comparison and identification by the comparing/identifying unit  103 . That is, the data update by the updating unit  104  is performed for each of areas of the storage unit  101 . The updating unit  104  controls the update such that if the comparing/identifying unit  103  identifies, by comparison, the data required for the navigation operation acquired by the acquiring unit  102  to be newer, the data required for the navigation operation acquired by the acquiring unit  102  are written into the area to be updated among the areas of the storage unit  101  after the data required for the navigation operation stored in the storage unit  101  are deleted. 
     At least while the updating unit  104  is updating the data required for the navigation operation, the control unit  105  performs the navigation operation with the use of data not in the process of being updating among the data required for the navigation operation stored in the storage unit  101  and the data required for the navigation operation acquired by the acquiring unit  102 . Therefore, regardless of whether the updating unit  104  is updating the data required for the navigation operation, the control unit  105  can perform the navigation operation using the data required for the navigation operation from the storage unit  101  or the acquiring unit  102 . 
     If the comparing/identifying unit  103  identifies, by comparison, the data required for the navigation operation acquired by the acquiring unit  102  to be newer, the control unit  105  performs the navigation operation utilizing program data included in the acquired data. Therefore, the control unit  105  can perform the navigation operation with the data required for the navigation operation acquired from the external recording medium. 
     The updating unit  104  adds index information indicating update states of the data required for the navigation operation stored in the areas of the storage unit  101 , and the control unit  105  refers to the index information added by the updating unit  104  and can preferentially use the updated data necessary for the navigation operation stored in the areas of the storage unit  101  to perform the navigation operation if the index information indicates that the data are updated. 
     The output unit  106  outputs data related to the progress of the data update performed by the updating unit  104  and data related to the navigation operation performed by the control unit  105 . The data output of the output unit  106  is performed through display output or audio output. 
     In the navigation apparatus with this configuration, the control unit  105  can use the data not in the process of being updated to perform the navigation operation even when the updating unit  104  is updating the data required for the navigation operation. Therefore, with this navigation apparatus, the navigation function can be utilized even during the data update and the convenience for users can be improved. 
     In the area to be updated among the areas of the storage unit  101 , new data can be written after stored data are deleted. Therefore, a conventionally required given amount of work area of the storage unit  101  is not needed for the data update, and the capacity of the storage unit  101  can be reduced. Since the updating unit  104  adds the index information, if the data update is interrupted, the data update can easily be resumed. Since the navigation operation can be performed utilizing the updated data stored in the areas of the storage unit  101  by reference to the index information, high-speed navigation operation can easily be continued. 
     (Data Updating Process Procedure of Navigating Apparatus) 
     The data updating process of the navigation apparatus according to the embodiment of the present invention will be described.  FIG. 2  is a flowchart of an example of the data updating process of the navigation apparatus according to the embodiment of the present invention. In  FIG. 2 , the data required for the navigation operation are referred to as “data”. 
     In the flowchart shown in  FIG. 2 , first, the acquiring unit  102  acquires data from an external recording medium (step S 201 ). The comparing/identifying unit  103 , using the data stored in the storage unit  101  and the data acquired by the acquiring unit  102 , compares both data and identifies the newer data (step S 202 ). 
     After comparing and identifying both data, the updating unit  104  controls the update of the data in the areas of the storage unit  101  based on the comparison/identification results (step S 203 ). At least while the updating unit  104  is updating the data, the control unit  105 , using the data stored in the storage unit  101  and the data acquired by the acquiring unit  102  to perform the navigation operation, uses data not in the process of being updated among both data (step S 204 ), thereby terminating the data update process in this flowchart. 
     Although not shown, the output unit  106  may output data related to progress of the data update at step S 203  and data related to the navigation operation at step S 204  by display or audio output. Through the execution of this data updating process, the navigation operation can be performed utilizing data not in the process of being updating even when the data update is in progress, and the convenience for users can be improved since the navigation function can be utilized even during the data update. 
     As described above, with the navigation apparatus according to the embodiment of the present invention, the navigation operation can be performed utilizing data not in the process of being updating even when the update of the data required for the navigation operation is in progress. Therefore, the navigation function can be utilized even during the update of the data required for the navigation operation and the convenience for users can be improved. 
     An example according the embodiment of the present invention will then be described. A data updating method according to the embodiment will be described here by exemplifying the case of implementing the data updating method according to the embodiment in a vehicle-mounted navigation apparatus. 
     Example 
     Hardware Configuration of Navigation Apparatus 
     A hardware configuration of the navigation apparatus according to the example of the present invention will be described.  FIG. 3  is a block diagram of an example of the hardware configuration of the navigation apparatus according to the example of the present invention. 
     As shown in  FIG. 3 , the navigation apparatus includes a CPU  301 , a ROM  302 , a RAM  303 , an HDD (hard disc drive)  304 , an HD (hard disc)  305 , a DVD drive  306 , a DVD  307  that is an example of a removable recording medium, a video/audio I/F (interface)  308 , a speaker (or headphone)  309 , a display (or touch panel)  310 , an input I/F (interface)  311 , input keys  312 , a remote controller  313 , a communication I/F (interface)  314 , a GPS receiver  315 , and a sensor  316 . The constituent units  301  to  316  are connected through a bus  320  to each other. 
     The CPU  301  executes predetermined calculation processes and is responsible for the overall control of the navigation apparatus. Specifically, the CPU  301  executes processes related to the navigation operation for the navigation and executes processes related to the data update for the data update. The navigation operation and the data update may concurrently be performed with the CPU  301 , and a plurality of the CPUs  301  may be disposed. 
     The ROM  302  stores so-called static data, such as a boot program. In this case, specifically, the ROM  302  stores a basic processing program of the navigation apparatus. Although the data stored in the ROM  302  can be rewritten, for example, by user operations, the data are not erased by power-off. 
     The RAM  303  stores so-called variable data in a rewritable manner and is used as a work area of the CPU  301 . For example, the RAM  303  may be a volatile memory where stored data are erased by power-off or may be a non-volatile memory which is backed up by a battery, etc. 
     The HDD  304  controls read/write of data to/from the HD  305  under the control of the CPU  301 . The HD  305  stores the data written under the control of the HDD  304 . Specifically, for example, the HDD  305  stores the map data used for the navigation. The HD  305  also stores various program data necessary for implementing the navigation function, for example. 
     The map data stored in the HD  305  include background data indicating geographic objects, for example, buildings, rivers, and ground surfaces, and road-shape data indicating the shapes of roads, and are data depicted two-dimensionally or three-dimensionally on the display (or touch panel)  310  described hereinafter. 
     The background data include background-shape data indicating shapes of the background and background-type data indicating types of the background. The background-shape data include data indicating representative points of geographic objects, polylines, polygons, and coordinates of geographic objects, for example. The background-type data include text data indicating names, addresses, and telephone numbers of geographic objects, for example, and type data indicating types of geographic objects such as buildings and rivers. 
     The road-shape data are data related to a road network having pluralities of nodes and links. The node is data indicating an intersection where roads intersect, such as three-way intersections, crossroads, and five-way intersections. The link is data indicating a road linking the nodes. Some links include supplemental-shape points that enable representation of curved roads. 
     The road-shape data also include traffic condition data. The traffic condition data are data indicating characteristics of intersections, lengths (distances) of the links, vehicle widths, movement directions, road types, etc. The characteristics of intersections include intersections having complicated shapes such as three-way intersections and five-way intersections, intersections formed by roads branched at a shallow angle, intersections in the vicinity of a destination, approaches/exits and junctions of expressways, and intersections with a high route deviation rate. The route deviation rate can be calculated from past travel histories of a vehicle, for example. The road types include expressways, toll roads, and general roads, for example. 
     The DVD drive  306  controls read/write of data to/from the DVD  307  under the control of the CPU  301 . The DVD  307  is a writable and removable recording medium in the form having recorded thereon the data written under the control of the DVD drive  306  and enabling the recorded data to be read in accordance with the control of the DVD drive  306 . Specifically, the DVD  307  stores the map data similar to the data stored in the above HD  305 , for example, and various program data. The data recorded on the DVD  307  include data newer than those stored in the HD  305 . 
     For example, various recording media such as CD-ROMs (CD-R, CD-RW), MOs (Magneto-Optical disc), and memory cards can be utilized for the removable recording medium along with the above DVD  307 . When utilizing these recording media, dedicated drive apparatuses capable of writing data onto the various recording media and reading data recorded on the various recording media may arbitrarily be used instead of the DVD drive  306  or in addition to the DVD drive  306 . The map data and the various program data stored (recorded) on the HD  305  and the DVD  307  may permanently or temporarily be stored in the ROM  302  or the RAM  303 . 
     The video/audio I/F  308  is connected to the speaker (or headphone, the same applies hereinafter)  309  for audio output and the display (or touch panel, the same applies hereinafter)  310  for video display. Specifically, the video/audio I/F  308  includes, for example, a D/A converter that converts audio digital signals into audio analog signals, an amplifier that amplifies the audio analog signals output from the D/A converter, and an A/D converter that converts the audio analog signals into the audio digital signals for audio control. 
     Specifically, the video/audio I/F  308  includes, for example, a graphic controller that generally controls the display  310 , a buffer memory such as VRAM (Video RAM) that temporarily stores data such as images that can immediately be displayed, and a control IC or GPU (Graphics Processing Unit) that controls image display on the display  310  based on data output from the graphic controller for video control. 
     Specifically, the speaker  309  outputs navigation guide sounds for the navigation, for example. The speaker  309  also outputs sounds based on audio data acquired through the communication I/F  314  described hereinafter. If a headphone is employed as the speaker  309 , the output style of the guide sounds and the sounds can adaptively be changed such that the entire inner portion of the vehicle equipped with the navigation apparatus does not become the sound field for the output sounds 
     The display  310  can be any one of a variety of displays such as CRTs (Cathode Ray Tubes), TFT (Thin Film Transistor) liquid crystal displays, organic EL (Electroluminescence) displays, and plasma displays. Specifically, the display  310  can be configured by a display apparatus for video display connected to the video/audio I/F  308 , for example. The display  310  displays icons, cursors, menus, windows, or various types of information such as texts and images. 
     If the display  310  is a touch panel, the display  310  is connected to the input I/F  311  described hereinafter, and press-down/non-press-down of the touch panel is detected and input into the input I/F  311 . In this case, the touch panel is superimposed and used on the display  309 , for example. The CPU  301  manages the display timing of images on the display  309  and the timing of user operations and the position coordinates thereof through the input I/F  311  to recognize information input by input operations. The touch panel can be any one of various known touch panels such as a resistive-film type and a pressure-sensitive type. 
     The input I/F  311  outputs to the CPU  301  the information input through user operations such as characters, numeric values, and various instructions transmitted from the input keys  312  or the remote controller  313  including some or all of the input keys  312 . The input keys  312  are configured by and the functions thereof are implemented by various known forms such as push-button switches physically detecting press-down/non-press-down, a keyboard, a joystick, a track ball, a mouse, and input buttons included in the navigation apparatus, and combinations thereof. 
     A microphone that inputs external sounds may be employed instead of the input keys  312  or along with the input keys  312  to enable input operations to be performed through sounds. The remote controller  313  transmits information to the input I/F  311  from a position that is remote from the navigation apparatus. As described above, if a touch panel superimposed on the display  310  is employed and information can be input from the touch panel to the input I/F  311 , a large amount of information can be input without increasing the size of the input keys  312 . 
     The communication I/F  314  has, for example, an antenna not shown and a function of a communication interface (I/F), and is connected to the GPS receiver  315  and the sensor  316 . The communication I/F  314  communicates various data between the apparatuses or devices mounted on the vehicle and the navigation apparatus. The communication I/F  314  also communicates with other navigation apparatuses and communicates with an external server not shown through a network  330  such as the Internet. Therefore, the communication I/F  314  can be implemented as a communication device. 
     The transmission/reception of various data may be performed by the communication I/F  314  regardless of whether it is in a wired or wireless form. The communication I/F  314  may be a communication module such as a mobile phone that performs communication with a communication server through a base station not shown or may be a communication module that performs wireless communication directly with other navigation apparatuses. 
     The wireless communication of the communication I/F  314  is communication performed by using radio wave, infrared light, supersonic wave, etc., without using wire lines acting as communication media. For example, standards enabling such wireless communication include various technologies such as wireless LAN (Local Area Network), IrDA (Infrared Data Association), HomeRF (Home Radio Frequency), and BlueTooth, and in this example, various known wireless communication technologies can be employed. The wireless LAN can be used as a preferred example from the viewpoint of data transfer rate. 
     For the navigation, the communication I/F  314  may regularly (or irregularly) receive traffic information such as congestion and traffic regulations. Specifically, the communication I/F  314  may receive the traffic information according to the timing of delivery of the traffic information from the VICS (Vehicle Information and Communication System) center or by regularly requesting the VICS center to deliver the traffic information. In this case, the communication I/F  314  includes a VICS/beacon receiver, for example. 
     Although detailed description will be omitted as the technology is conventionally known, the “VICS” is an information communication system that transmits traffic information such as congestion and traffic regulations edited/processed in the VICS center in real time to display the traffic information with characters and graphics on vehicle-mounted devices such as navigation apparatuses. Modes for delivering the traffic information edited/processed in the VICS center (VICS information) to navigation apparatuses include a mode of utilizing “beacons” disposed over roads and a mode of utilizing the “FM multiplex broadcasting”. 
     The “beacons” include “radio beacons” mainly used over expressways and “optical beacons” used over main general roads. If the “FM multiple broadcasting” is utilized, a broad-area traffic information can be received. If the “beacons” are utilized, the received information can be traffic information necessary for the position where the own vehicle is located, such as detailed information of nearby roads based on the current position of the vehicle (vehicle position). When receiving the map data and the traffic information from other navigation apparatuses, the communication I/F  314  may include a plurality of communicating units respectively corresponding to the communication mode used in the other navigation apparatuses if different. 
     The GPS receiver  315  receives radio waves, for example, from satellites to acquire current position information (latitude/longitude information) of the vehicle. The current position information is information for obtaining a geometric position relative to the satellites when receiving radio waves from the satellites as described above, and the measurement can be performed anywhere on the earth. The GPS receiver  315  includes a GPS antenna not shown. 
     The GPS (Global Positioning System) is a system that receives radio waves from four or more satellites to precisely obtain a position on the ground. Detailed description of the GPS is omitted herein as the technology is conventionally known. As the radio waves from the satellites, carrier waves of 1.57542 GHz and the L1 carrier wave, which carries the C/A (Coarse and Access) codes and navigation messages, are used; thereby enabling the detection of the current position (latitude and longitude) of the vehicle equipped with the navigation apparatus. 
     When the current position of the vehicle is detected, in addition to the current position information acquired by the GPS receiver  315 , the sensor  316  detects various pieces of information that are taken into consideration. That is, the sensor  316  is configured, for example, by a speed sensor that detects the speed of the traveling vehicle, an incline sensor that detects an incline angle of the vehicle, an acceleration sensor that detects acceleration of the vehicle, a lateral G sensor that detects the lateral G (gravity), which is an outward force (gravity) generated by the lateral acceleration at the time of cornering, and a gyroscopic sensor that detects the traveling direction of the vehicle. 
     Although not shown, the navigation apparatus includes a navigation control unit, a guide sound output unit, a position searching unit, a route acquiring unit, a route guiding unit, and a guide sound generating unit, in addition to the above constituent units. The navigation control unit outputs, to the display  310 , information, e.g., a location on a map where the vehicle is traveling, based on the current vehicle position information (vehicle position information) acquired by the GPS receiver  315  through the communication I/F  314  and the map data read from the HD  305  or the DVD  307  through the HDD  304  or the DVD drive  306 , for example. 
     The guide sound output unit controls output to one or a plurality of the speakers  309  through the video/audio I/F  314  to output (reproduce) the guide sounds for the navigation, for example. A point searching unit searches and outputs an arbitrary point to the display  310  based on the information input through the input I/F  311 , for example. The route acquiring unit calculates the optimal route, etc., to the point based on the point information acquired by the point searching unit. A route guiding unit generates real-time route guidance information based on the information related to the route acquired by the route acquiring unit and the vehicle position information. 
     For example, the guide sound generating unit generates data of tones and sounds corresponding to various guide patterns for the navigation. That is, based on the route guide information generated by the route guiding unit, the guide sound generating unit performs setting of a virtual sound source corresponding to the guide points and generates the sound guidance data, which are output to the guide sound output unit. 
     Specifically, for example, the function of the storage unit  10  shown in  FIG. 1  is implemented by the RAM  303  and the HD  305  and the function of the acquiring unit  102  is implemented by the DVD drive  306  and the DVD  307 . Specifically, for example, the function of the comparing/identifying unit  103  shown in  FIG. 1  is implemented by the CPU  301 , and the function of the output unit  106  shown in  FIG. 1  is implemented by the speaker  309  and the display  310 . 
     (Overview of Navigation Operation Process and Data Update Process of Navigation Apparatus) 
     An overview of a navigation operation process and a data update process of the navigation apparatus according to the example of the present invention will be described.  FIG. 4  is a schematic view of the navigation operation process and the data update process of the navigation apparatus according to the example of the present invention. Specifically, the process shown in  FIG. 4  is implemented by the CPU  301  executing the program stored (recorded) in the ROM  302 , the RAM  303 , the HD  305 , the DVD  307 , etc., of the navigation apparatus shown in  FIG. 3 , for example. 
     In  FIG. 4 , the CPU  301  includes functions of a data update processing unit  401  and a navigation control unit  402 . The HD  305  includes a data area  403  storing the map data and the program data (hereinafter, “data”), which are required for the navigation operation, and a user area  404  storing the user data related to the navigation operation. The DVD drive  306  includes the DVD  307  having recorded thereon the data related to the navigation operation. 
     The CPU  301  can concurrently execute the data update process of the data update processing unit  401  and the navigation operation process of the navigation control unit  402 . That is, in the data update process executed by the data update processing unit  401 , the data stored in the data area  403  of the HD  305  and the data recorded on the DVD  307  are compared to identify the newer data, for example. 
     If the data recorded on the DVD  307  are newer, the data update processing unit  401  deletes, from the data area  403  of the HD  305 , update target data corresponding to relevant updatable data and reads the update target data from the DVD  307  as shown by an arrow  410 . The update target data read from the DVD  307  are written into the data area  403  of the HDD  305  to execute the data update process as shown by an arrow  411 . At this time, the data update processing unit  401  adds, to the HD  305 , index information indicating a data update state. 
     On the other hand, at least while the data update processing unit  401  is updating the data, the navigation operation process executed by the navigation control unit  402  is executed by reading data not in the process of being updating among the data stored in the data area  403  of the HDD  305 , as shown by an arrow  412 , and the data recorded in the DVD  307 , as shown in an arrow  413 . 
     At this time, the navigation control unit  402  writes, into the user area  404  of the HD  305 , the user data associated with the user operation input as shown by an arrow  414 . As described above, the CPU  301  can concurrently execute the data update process of the data update processing unit  401  and the navigation operation process of the navigation control unit  402 . As shown by an arrow  415 , the data related to the processes executed by the CPU  301  are output to and displayed on the display  310  after a drawing process. 
     (Data Update Process of Navigation Apparatus) 
     A data update process of the navigation apparatus according to the example of the present invention will be described as a premise of the navigation operation process and the data update process described above.  FIG. 5  is a flowchart of the data update process of the navigation apparatus according to the example of the present invention.  FIGS. 6 to 9  are explanatory views of an overview of the data update process of the navigation apparatus according to the example of the present invention. Specifically, the process shown in  FIG. 5  is implemented by the CPU  301  executing the program stored (recorded) in the ROM  302 , the RAM  303 , the HD  305 , the DVD  307 , etc., of the navigation apparatus shown in  FIG. 3 , for example. In the following description, the same reference numerals are given to elements identical to the elements already described and the description thereof will be omitted. 
     As shown in  FIG. 5 , the CPU  301  determines whether the DVD  307  has been inserted through the DVD drive  306  (step S 501 ). If it is determined that the DVD  307  has not been inserted (step S 501 : NO), the process is repeated. If it is determined that the DVD  307  has been inserted (step S 501 : YES), the CPU  301  compares and identifies the data stored (recorded) in the data area  403  of the HD  305  and the data recorded on the DVD  307  to determine whether the update target data exist on the DVD  307  (step S 502 ). 
     If it is determined that the update target data exist (step S 502 : YES), the data update processing unit  401  of the CPU  301  starts the data update process (step S 503 ). When the data update process is started, the data update processing unit  401  of the CPU  301  refers to the index information of the HD  305  to determine whether the update target data have been updated (step S 504 ). 
     If it is determined that the update target data have not updated (step S 504 : NO), the data update processing unit  401  of the CPU  301  reads the update target data from the DVD  307 , writes the data into the data area  403  of the HD  305  (step S 505 ), and rewrites the index information to indicate “not-updated (not done)→updated (done)” (step S 506 ). 
     That is, specifically, as shown in  FIG. 6 , at the step S 504 , the data update processing unit  401  of the CPU  301  refers to the index information stored in an index area  601  of the HD  305  as shown by an arrow  602 . The data update processing unit  401  then compares program data and map data (A) to (C) recorded on the DVD  307  and program data and map data (A) to (C) recorded in the data area  403  of the HD  305 . If the update target data are present on the DVD  307 , the data update processing unit  401  reads the update target data from the DVD  307  and writes the data into the data area  403  of the HD  305  at the aforementioned step S 505  as shown by an arrow  603 . The data update is performed starting from the program data in this case. 
     When the data update of the program data is completed, the data update processing unit  401  of the CPU  301  rewrites the index information in the index area  601  of the HD  305  to indicate “not-updated (not done)→updated (done)” as shown in  FIG. 7  at step S 506 . After the index information is rewritten at step S 506 , the process goes to step S 504  to execute a determination process. If it is determined at step S 502  that no update target data are present (step S 502 : NO) and if it is determined at step S 504  that the update target data have been updated (step S 504 : YES), the data update process of this flowchart is terminated. 
     Therefore, as shown in  FIGS. 8 and 9 , the data update processing unit  401  of the CPU  301  executes the abovementioned data update process for the map data (A) to (C) stored in the data area  403  of the HD  305  after the update of the program data has been completed. For example, as shown in  FIG. 8 , the data update has been completed for the program data and the map data (A) in the data area  403  of the HD  305 , and the index information of the index area  601  has been rewritten to indicate “not-updated (not done)→updated (done)”. As shown in  FIG. 9 , the data update has been completed from the program data to the map data (B) in the data area  403  of the HD  305  and the index information of the index area  601  has been rewritten to indicate “not-updated (not done)→updated (done)”. 
     (Overview of Navigation Operation of Navigation Apparatus) 
     An overview of the navigation operation of the navigation apparatus according to the example of the present invention will be described.  FIGS. 10 to 13  are explanatory views of the overview of the navigation operation of the navigation apparatus according to the example of the present invention. Specifically, processes shown in  FIGS. 10 to 13  are implemented by the CPU  301  executing the program stored (recorded) in the ROM  302 , the RAM  303 , the HD  305 , the DVD  307 , etc., of the navigation apparatus shown in  FIG. 3 , for example. This navigation operation process is concurrently executed with the abovementioned data update process. 
     As shown in  FIG. 10 , the navigation control unit  402  of the CPU  301  refers to the index information stored in the index area  601  of the HD  305  as shown by an arrow  1001 . The navigation control unit  402  utilizes data not in the process of being updating (i.e., data other than the data utilized by the data update processing unit  401  for the data update) among the program data and the map data (A) to (C) recorded on the DVD  307  and the program data and the map data (A) to (C) stored in the data area  403  of the HDD  305  and performs the navigation operation while writing the user data into the user area  404  of the HD  305  as shown by an arrow  1006  regardless of whether the data update process is in progress. 
     First, the navigation control unit  402  uses (reads) the program data and the map data (A) to (C) of the DVD  307  as shown by arrows  1002  to  1005 . The navigation control unit  402  performs the navigation operation while writing the user data into the user area  404  of the HD  305  as shown by the arrow  1006 . In this case, since the program data of the DVD  307  are utilized once the program data of the DVD  307  are read into, for example, the RAM  303 , the data update processing unit  401  executes the data update process of the program data in the background. 
     The navigation control unit  402  then refers to the index information stored in the index area  601  of the HD  305  as shown by the arrow  1001 . If the data update of the program data has been completed, the navigation control unit  402  preferentially uses the program data written into the data area  403  of the HD  305  to perform the navigation operation as shown by an arrow  1007 . Therefore, in this state, the navigation control unit  402  performs the navigation operation by utilizing the program data written into the data area  403  of the HD  305  as shown by the arrow  1007  and the map data (A) to (C) of the DVD  307  as shown by the arrows  1003  to  1005 . In this case, for the map data (A) of the DVD  307 , the data update processing unit  401  executes the data update process in the background. 
     As shown in  FIG. 12 , the navigation control unit  402  refers to the index information stored in the index area  601  of the HD  305  as shown by the arrow  1001 . If the data update has been completed for the program data and the map data (A), the navigation control unit  402  uses the program data and the map data (A) written into the data area  403  of the HD  305  for the program data and the map data (A) as shown by arrows  1007  and  1008  and the map data (B) and the map data (C) recorded on the DVD  307  for the map data (B) and the map data (C) as shown by arrows  1004  and  1005  to perform the navigation operation. In this case, for the map data (B) of the DVD  307 , the data update processing unit  401  executes the data update process in the background. 
     Further, as shown in  FIG. 13 , the navigation control unit  402  refers to the index information stored in the index area  601  of the HD  305  as shown by the arrow  1001 . If the data update has been completed for the program data, the map data (A), and the map data (B), the navigation control unit  402  uses the program data, the map data (A), and the map data (B) written into the data area  403  of the HD  305  for the program data, the map data (A), and the map data (B) as shown by arrows  1007 ,  1008 , and  1009 , and uses the map data (C) recorded on the DVD  307  for the map data (C) as shown by arrow  1005  to perform the navigation operation. In this case, for the map data (C) of the DVD  307 , the data update processing unit  401  executes the data update process in the background. 
     If all the update target data recorded on the DVD  307  are written into the data area  304  of the HD  305  and the data update process of the data update processing unit  401  has been completed, the navigation control unit  402  may use the program data and the map data (A) to (C) written into the data area  304  of the HD  305  to perform the navigation operation since the HD  305  exceeds the DVD  307  in the aspect of the transfer rate. 
     By executing the data update process and the navigation operation process with the navigation apparatus according to the example of the present invention, the navigation operation can be performed utilizing data not in the process of being updating even when the data update is in progress, and the convenience for the user can be improved enabled utilization of the navigation function even during the data update. Although the data update process has been described using the DVD  307  here, any external recording medium such as a memory card and a PC card may be employed. 
     As described above, the navigation apparatus according to the example of the present invention can perform the navigation operation by utilizing data not in the process of being updating even when the data required for the navigation operation is being updated, and the navigation function can be utilized even during the update of data, thereby improving the convenience for users. 
     The data updating method described in the embodiment can be implemented by executing a preliminarily prepared program with a computer such as a personal computer and a workstation. The program is recorded on a computer-readable medium such as a hard disc, a flexible disc, a CD-ROM, an MO, and a DVD and is read from the recording medium by the computer for execution. The program may be a transmission medium distributable through a network such as the Internet.