Patent Publication Number: US-2012041678-A1

Title: Position information detecting apparatus, position information detecting method, position information detecting program and storage medium

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a division of co-pending application Ser. No. 12/531,893 filed on Sep. 18, 2009, which is a National Stage of PCT/JP2007/056237 filed on Mar. 26, 2007. The entire content of each of these applications is hereby expressly incorporated by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a method of detecting position information corresponding to an address. 
     BACKGROUND TECHNIQUE 
     Conventionally, there is known a navigation apparatus which estimates a position of a facility corresponding to a range of a lot number, by using an address range data associating a link with a range of lot numbers along the link (For example, see. Patent Reference-1). 
     Patent Reference-1: Japanese Patent Application Laid-open under No. 2006-214965 
     DISCLOSURE OF INVENTION 
     Problem to be Solved by the Invention 
     However, in the above navigation apparatus, the estimated facility position may include an error when the lot numbers of the address range data are not equally allocated. 
     The above is an example of the problem to be solved by the present invention. It is an object of this invention to provide a position information detecting apparatus capable of detecting the position information corresponding to an address with high accuracy. 
     Means for Solving the Problem 
     According to the invention of claim  1 , a position information detecting apparatus includes: a pinpoint information storing means which stores pinpoint information including address information including a first address part and a second address part, and position information corresponding to the address information; a range information storing means which stores range information including range information of the address information and position information corresponding to the range information of the address information; a pinpoint information searching means which searches the pinpoint information storing means for the pinpoint information including the first address part which coincides with the first address part of inputted address information; a pinpoint information detecting means which detects the pinpoint information including the second address part which coincides with the second address part of the inputted address information; a range information searching means which searches the range information storing means for the range information including the first address part which coincides with the first address part of the inputted address information; an estimated position information calculating means which calculates estimated position information by estimating the position information corresponding to the inputted address information, by using the range information searched by the range information searching means and the pinpoint information searched by the pinpoint information searching means; and a detection-object position information determining means which determines the position information of the pinpoint information as a detection-object position information when the pinpoint information detecting means detects the pinpoint information, and determines the estimated position information calculated by the estimated position information calculating means as the detection-object position information when the pinpoint information detecting means does not detect the pinpoint information. 
     According to the invention of claim  3 , a position information detecting method includes: a pinpoint information storing process which stores pinpoint information including address information including a first address part and a second address part, and position information corresponding to the address information; a range information storing process which stores range information including range information of the address information and position information corresponding to the range information of the address information; a pinpoint information searching process which searches the pinpoint information storing process for the pinpoint information including the first address part which coincides with the first address part of inputted address information; a pinpoint information detecting process which detects the pinpoint information including the second address part which coincides with the second address part of the inputted address information; a range information searching process which searches the range information storing process for the range information including the first address part which coincides with the first address part of the inputted address information; an estimated position information calculating process which calculates estimated position information by estimating the position information corresponding to the inputted address information, by using the range information searched by the range information searching process and the pinpoint information searched by the pinpoint information searching process; and a detection-object position information determining process which determines the position information of the pinpoint information as a detection-object position information when the pinpoint information detecting process detects the pinpoint information, and determines the estimated position information calculated by the estimated position information calculating process as the detection-object position information when the pinpoint information detecting process does not detect the pinpoint information. 
     According to the invention of claim  4 , a position information detecting program executed by an apparatus includes a computer, the program makes the computer to function as: a pinpoint information storing means which stores pinpoint information including address information including a first address part and a second address part, and position information corresponding to the address information; a range information storing means which stores range information including range information of the address information and position information corresponding to the range information of the address information; a pinpoint information searching means which searches the pinpoint information storing means for the pinpoint information including the first address part which coincides with the first address part of inputted address information; a pinpoint information detecting means which detects the pinpoint information including the second address part which coincides with the second address part of the inputted address information; a range information searching means which searches the range information storing means for the range information including the first address part which coincides with the first address part of the inputted address information; an estimated position information calculating means which calculates estimated position information by estimating the position information corresponding to the inputted address information, by using the range information searched by the range information searching means and the pinpoint information searched by the pinpoint information searching means; and a detection-object position information determining means which determines the position information of the pinpoint information as a detection-object position information when the pinpoint information detecting means detects the pinpoint information, and determines the estimated position information calculated by the estimated position information calculating means as the detection-object position information when the pinpoint information detecting means does not detect the pinpoint information. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a conceptual diagram of a navigation apparatus according to an embodiment; 
         FIG. 2  is a block diagram showing a schematic configuration of a position information detecting apparatus; 
         FIG. 3  is a conceptual diagram of data structure of a pinpoint information DB; 
         FIG. 4  is a conceptual diagram of data structure of a range information DB; 
         FIGS. 5A and 5B  show examples of dividing the range information; 
         FIGS. 6A and 6B  show effects in a case that the position is estimated by using divided range information; 
         FIG. 7  is a flowchart showing a position information detecting process; and 
         FIG. 8  is a flowchart showing a position information detecting process (range information division). 
     
    
    
     BRIEF DESCRIPTION OF REFERENCE NUMBERS 
     
         
         
           
               101  Pinpoint information searching unit 
               102  Pinpoint information detecting unit 
               103  Range information searching unit 
               104  Estimated position information calculating unit 
               105  Detection-object position information determining unit 
               106  Map searching unit 
               120  Pinpoint information DB 
               140  Range information DB 
               200  Navigation apparatus 
               300  Position information detecting apparatus 
           
         
       
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     According to one aspect of the present invention, there is provided a position information detecting apparatus including: a pinpoint information storing means which stores pinpoint information including address information including a first address part and a second address part, and position information corresponding to the address information; a range information storing means which stores range information including range information of the address information and position information corresponding to the range information of the address information; a pinpoint information searching means which searches the pinpoint information storing means for the pinpoint information including the first address part which coincides with the first address part of inputted address information; a pinpoint information detecting means which detects the pinpoint information including the second address part which coincides with the second address part of the inputted address information; a range information searching means which searches the range information storing means for the range information including the first address part which coincides with the first address part of the inputted address information; an estimated position information calculating means which calculates estimated position information by estimating the position information corresponding to the inputted address information, by using the range information searched by the range information searching means and the pinpoint information searched by the pinpoint information searching means; and a detection-object position information determining means which determines the position information of the pinpoint information as a detection-object position information when the pinpoint information detecting means detects the pinpoint information, and determines the estimated position information calculated by the estimated position information calculating means as the detection-object position information when the pinpoint information detecting means does not detect the pinpoint information. 
     The above position information detecting apparatus is specifically applicable to a car navigation apparatus and a personal computer. The position information detecting apparatus stores the pinpoint information and the range information, in advance. The pinpoint information includes address information including a first address part (city name and street name) and a second address part (house number), and position information corresponding to the address information (latitude and longitude information). The range information includes the range information of the address information, and the position information corresponding to the range information of the address information. 
     The position information detecting apparatus obtains the pinpoint information which coincides with the first address part of the inputted address information, from the pinpoint information storing means, and thereafter detects the pinpoint information which coincides with the inputted second address information. If the position information detecting apparatus can detect the pinpoint information, it determines the position information included in the detected pinpoint information as the detection-object position information. If the position information detecting apparatus cannot detect the pinpoint information, it searches for the range information which coincides with the first address part of the inputted address information. Then, the position information detecting apparatus estimates the position information corresponding to the inputted address information by using the searched range information and the searched pinpoint information. 
     As described above, the position information detecting apparatus determines the position information of the pinpoint information as the detection-object position information if the pinpoint information coinciding with the inputted address information exists, and estimates the inputted position information by using the pinpoint information coinciding with the first address part of the inputted address information and the range information coinciding with the first address part of the inputted address information if the pinpoint information coinciding with the inputted address information does not exist. 
     Therefore, since the position information detecting apparatus estimates the position of the inputted address information from the range information including the inputted information in the address range, by using the pinpoint information storing the position information corresponding to the address information, the estimation accuracy of the position information can be improved, in comparison with the case in which the position of the inputted address information is estimated by using only the range information. 
     According to one feature of the above position information detecting apparatus, the estimated position information calculating means generates divided range information by dividing the range information searched by the range information searching means by using the pinpoint information searched by the pinpoint information searching means, and calculates the estimated position information based on the divided range information. In this case, by dividing the existing range information by using the pinpoint information, the position information detecting apparatus narrows the address range of the existing range information (the range of the house numbers). Therefore, if the inputted position information is estimated by using the divided range information, the detection accuracy of the position information can be improved, in comparison with the case in which the position information is estimated by the existing range information. 
     According to another aspect of the present invention, there is provided a position information detecting method including: a pinpoint information storing process which stores pinpoint information including address information including a first address part and a second address part, and position information corresponding to the address information; a range information storing process which stores range information including range information of the address information and position information corresponding to the range information of the address information; a pinpoint information searching process which searches the pinpoint information storing process for the pinpoint information including the first address part which coincides with the first address part of inputted address information; a pinpoint information detecting process which detects the pinpoint information including the second address part which coincides with the second address part of the inputted address information; a range information searching process which searches the range information storing process for the range information including the first address part which coincides with the first address part of the inputted address information; an estimated position information calculating process which calculates estimated position information by estimating the position information corresponding to the inputted address information, by using the range information searched by the range information searching process and the pinpoint information searched by the pinpoint information searching process; and a detection-object position information determining process which determines the position information of the pinpoint information as a detection-object position information when the pinpoint information detecting process detects the pinpoint information, and determines the estimated position information calculated by the estimated position information calculating process as the detection-object position information when the pinpoint information detecting process does not detect the pinpoint information. 
     In this method, since the position of the inputted address information is estimated from the range information including the inputted information in the address range, by using the pinpoint information storing the position information corresponding to the address information, the estimation accuracy of the position information can be improved, in comparison with the case in which the position of the inputted address information is estimated by using only the range information. 
     According to still another aspect of the present invention, there is provided a position information detecting program executed by an apparatus including a computer, the program makes the computer to function as: a pinpoint information storing means which stores pinpoint information including address information including a first address part and a second address part, and position information corresponding to the address information; a range information storing means which stores range information including range information of the address information and position information corresponding to the range information of the address information; a pinpoint information searching means which searches the pinpoint information storing means for the pinpoint information including the first address part which coincides with the first address part of inputted address information; a pinpoint information detecting means which detects the pinpoint information including the second address part which coincides with the second address part of the inputted address information; a range information searching means which searches the range information storing means for the range information including the first address part which coincides with the first address part of the inputted address information; an estimated position information calculating means which calculates estimated position information by estimating the position information corresponding to the inputted address information, by using the range information searched by the range information searching means and the pinpoint information searched by the pinpoint information searching means; and a detection-object position information determining means which determines the position information of the pinpoint information as a detection-object position information when the pinpoint information detecting means detects the pinpoint information, and determines the estimated position information calculated by the estimated position information calculating means as the detection-object position information when the pinpoint information detecting means does not detect the pinpoint information. 
     By executing the program on various apparatuses, the position information detecting apparatus according to the present invention can be realized. The position information detecting program can preferably be handled in a stated recorded on a storage medium. 
     Embodiment 
     Now, a description will be given of a preferred embodiment of the present invention with reference to attached drawings. The following explanation shows such an example that the present invention is applied to an on-vehicle navigation apparatus. 
     [Navigation Apparatus] 
       FIG. 1  shows a configuration of a navigation apparatus  200  according to an embodiment of the present invention. As shown in  FIG. 1 , the navigation apparatus  200  includes a stand-alone position measurement device  10 , a GPS receiver  18 , a system controller  20 , a disc drive  31 , a data storage unit  36 , a communication interface  37 , a communication device  38 , a display unit  40 , a sound output unit  50 , and an input device  60 . 
     The stand-alone position measurement device  10  includes an acceleration sensor  11 , an angular velocity sensor  12  and a distance sensor  13 . The acceleration sensor  11  includes a piezoelectric element, for example, and detects the acceleration degree of the vehicle and outputs the acceleration data. The angular velocity sensor  12  includes a vibration gyroscope, for example, and detects the angular velocity of the vehicle at the time of changing the direction of the vehicle and outputs the angular velocity data and the relative direction data. The distance sensor  13  measures vehicle speed pulses including a pulse signal generated with the wheel rotation of the vehicle. 
     The GPS receiver  18  receives an electric wave  19  for transmitting downlink data including position measurement data from plural GPS satellites. The position measurement data is used for detecting the absolute position of the vehicle from longitude and latitude information. 
     The system controller  20  includes an interface  21 , a CPU  22 , a ROM  23  and a RAM  24 , and controls the entire navigation apparatus  200 . 
     The interface  21  executes the interface operation with the acceleration sensor  11 , the angular velocity sensor  12 , the distance sensor  13  and the GPS receiver  18 . Then, the interface  21  inputs the vehicle speed pulse, the acceleration data, the relative direction data, the angular velocity data, the GPS measurement data and the absolute direction data into the system controller  20 . The CPU  22  controls the entire system controller  20 . The ROM  23  includes a non-volatile memory (not shown) in which a control program for controlling the system controller  20  is stored. The RAM  24  readably stores various kinds of data such as route data preset by the user via the input device  60 , and supplies a working area to the CPU  22 . 
     The system controller  20 , the disc drive  31  such as a CD-ROM drive or a DVD-ROM drive, the data storage unit  36 , the communication interface  37 , the display unit  40 , the sound output unit  50  and the input device  60  are connected to each other via a bus line  30 . 
     Under the control of the system controller  20 , the disc drive  31  reads contents data such as sound data and video data from a disc  33  such as a CD and a DVD to output the contents data. The disc drive  31  may be the CD-ROM drive or the DVD-ROM drive, or may be a drive compatible between the CD and the DVD. 
     The data storage unit  36  includes HDD, for example, and stores various kinds of data used for a navigation process such as map data and facility data. 
     The communication device  38  includes an FM tuner, a beacon receiver, a mobile phone and a dedicated communication card, for example, and obtains various information via the communication interface  37 . 
     The display unit  40  displays various kinds of display data on a display device such as a display under the control of the system controller  20 . Concretely, the system controller  20  reads the map data from the data storage unit  36 . The display unit  40  displays, on a display screen such as a display, the map data read from the data storage unit  36  by the system controller  20 . The display unit  40  includes a graphic controller  41  for controlling the entire display unit  40  on the basis of the control data transmitted from the CPU  22  via the bus line  30 , a buffer memory  42  having a memory such as a VRAM (Video RAM) for temporarily storing immediately displayable image information, a display control unit  43  for controlling a display  44  such as a liquid crystal and a CRT (Cathode Ray Tube) on the basis of the image data outputted from the graphic controller  41 , and the display  44 . The display  44  is formed by a liquid crystal display device of the opposite angle 5-10 inches, and is mounted in the vicinity of a front panel of the vehicle. 
     The sound output unit  50  includes a D/A converter  51  for executing D/A conversion of the sound digital data transmitted from the disc drive  31  or the RAM  24  via the bus line  30  under the control of the system controller  20 , an amplifier (AMP)  52  for amplifying a sound analog signal outputted from the D/A converter  51 , and a speaker  53  for converting the amplified sound analog signal into the sound and outputting it to the vehicle compartment. 
     The input device  60  includes keys, switches, buttons, a remote controller and a sound input device, which are used for inputting various kinds of commands and data. The input device  60  is arranged in the vicinity of the display  44  and a front panel of a main body of an on-vehicle electric system loaded on the vehicle. Additionally, in such a case that the display  44  is a touch panel system, a touch panel provided on the display screen of the display  44  functions as the input device  60 , too. 
     [Position Information Detecting Apparatus] 
       FIG. 2  shows a functional configuration of a position information detecting apparatus  300 . Substantially, the position information detecting apparatus  300  is formed by the constitutional elements of the navigation apparatus  200 . As shown, the position information detecting apparatus  300  includes the system controller  20 , the data storage unit  36  and the input unit  60 . The data storage unit  36  includes a pinpoint information DB  120 , a range information DB  140  and a map information DB  160 . The system controller  120  includes a pinpoint information searching unit  101 , a pinpoint information detecting unit  102 , a range information searching unit  103 , an estimated position information calculating unit  104 , a detection-object position information determining unit  105  and a map searching unit  106 . Namely, by executing a predetermined program, the system controller  20  realizes the pinpoint information searching unit  101 , the pinpoint information detecting unit  102 , the range information searching unit  103 , the estimated position information calculating unit  104 , the detection-object position information determining unit  105  and the map searching unit  106 . 
     The pinpoint information DB  120  is a database storing pinpoint information  121 .  FIG. 3  shows an example of the pinpoint information DB  120 . The pinpoint information  121  is information including a city name  122 , a street name  123 , a house number  124  and a position information (latitude and longitude information)  125  corresponding to address information. It is noted that, in this embodiment, the word “address information” includes the city name, the street name and the house number. 
     If the position information detecting apparatus  300  can search the pinpoint information  121  that coincides with the inputted address information, it can obtain the position information of the inputted address information. 
     The range information DB  140  is a database storing the range information  141  which is position information corresponding to a predetermined address range. The range information  141  is set to every link. The “link” is latitude and longitude vector data sequence indicating the shape of a road segment. An example of the range information DB  140  is shown in  FIG. 4 . 
     As shown, the range information  141  includes a city name  142 , a street name  143 , left-side range information  145 , right-side range information  149  and a link shape  153 . The left-side range information  145  includes a left-side start point house number  146  and a left-side endpoint house number  147  and a left-side regularity  148 . The right-side range information  149  includes a right-side start point house number  150 , a right-side endpoint house number  151  and a right-side regularity  152 . 
     The left-side range information  145  relates to the house numbers on the left side of the road corresponding to the link. The left-side house number corresponding to the start point of the link is set to the left-side start point house number  146 , and the left-side house number corresponding to the end point of the link is set to the left-side endpoint house number  147 . The regularity (for example, odd number, even number, small-to-large order, etc.) of the arrangement order of the left-side house numbers is set to the left-side regularity  148 . 
     The right-side range information  149  relates to the house numbers on the right side of the road corresponding to the link. The right-side house number corresponding to the start point of the link is set to the right-side start point house number  150 , and the right-side house number corresponding to the end point of the link is set to the right-side end point house number  151 . The regularity of the arrangement order of the right-side house numbers is set to the right-side regularity  152 . 
     The link shape  153  includes the position information (latitude and longitude) of the start point and the end point of the link. If the link has an interpolating point, the link shape  153  includes the position information of the interpolating point. 
     In this embodiment, the information including the city name  142 , the street name  143 , the left-side range information  145  and the right-side range information  149  is referred to as “the range information of the address information” of the range information  141 . 
     The pinpoint information searching unit  101  searches the pinpoint information DB  120  for the pinpoint information  121  having the city name and the street name (hereinafter, the city name and the street name is referred to as “first address part”) coinciding with the first address part of the address information inputted by the input device  60 . 
     The pinpoint information detecting unit  102  detects the pinpoint information  121  including the house number  124  coinciding with the house number of the inputted address information (hereinafter, the house number is referred to as “second address part”), from the pinpoint information  121  searched by the pinpoint information searching unit  101 . 
     The range information searching unit  103  searches the range information DB  140  for the range information  141  having the first address part coinciding with the first address part of the inputted address information. 
     The estimated position information calculating unit  104  estimates the position information corresponding to the inputted address information by using the range information  141  searched by the range information searching unit  103 . The methods of estimating the position information corresponding to the inputted address information includes: a method of using only the range information  141  in which the range information of the address information includes the inputted address information, and another method of using the range information  141  (hereinafter referred to as “divided range information”) divided by using the pinpoint information  121  searched by the pinpoint information searching unit  101  and the range information  141  in which the range information of the address information includes the inputted address information. The estimated position information calculating unit  104  estimates the position information corresponding to the inputted address information on the premise that the positions from the start point house number to the end point house number in the range information  141  are equally allocated. 
     The detection-object position information determining unit  105  determines the position information of the pinpoint information  121  as the detection-object position information when the pinpoint information detecting unit  102  detects the pinpoint information  121  having the address information coinciding with the inputted address information, and determines the estimated position information calculated by the estimated position information calculating unit  104  as the detection-object position information when the pinpoint information detecting unit  102  does not detect the pinpoint information  121  having the address information coinciding with the inputted address information. 
     The map searching unit  106  performs the map search, by using the map information DB  160 , for the detection-object position information determined by the detection-object position information determining unit  105 . 
     The pinpoint information DB  120  in this embodiment functions as the pinpoint information storing means, and the range information DB  140  functions as the range information storing means. 
     [Division of Range Information] 
     Next, the division of the range information  141  will be described with reference to  FIGS. 5A and 5B . 
     The division of the range information  141  is to generate two range information  141  by using the pinpoint information  121  as the border, when there exists a pinpoint information  121  having the house number  124  coinciding with the house number included in the left-side range information  145  or the right-side range information  149  of the range information  141  searched by the range information searching unit  102 . 
     First, it is assumed that the range information searching unit  103  is searching for the range information  141 A in which the left-side start point house number  146 A is “1”, the left-side end point house number  147 A is “99”, the left-side regularity  148 A includes “Odd number” and “small-to-large”, as shown in  FIG. 5A . 
     In addition, it is assumed that the pinpoint information searching unit  101  searches the pinpoint information  121 A whose the house number  124 A is “15” and the pinpoint information  121 B whose house number  124 B is “57”. 
     In this case, the house number  124 A of the pinpoint information  121 A and the house number  124 B of the pinpoint information  121 B are located between the left-side start point house number  146  and the left-side end point house number  147  in the left-side range information  145  of the range information  141 A, and therefore the estimated position information calculating unit  104  divides the range information  141 A by using the house number  124 A and the house number  124 B. 
     As shown in  FIG. 5B , the estimated position information calculating unit  104  divides the range information  141 A into the divided range information  141 B, the divided range information  141 C and the divided range information  141 D. The divided range information  141 B has the left-side start point house number  146 B of “1” and the left-side end point house number  147 B of “15”. The divided range information  141 C has the left-side start point house number  146 C of “17” and the left-side end point house number  147 C of “57”. The divided range information  141 D has the left-side start point house number  146 D of “59” and the left-side end point house number  147 D of “99”. 
     The estimated position information calculating unit  104  calculates the position information of the left-side start point house number  146 C by using the link shape  153  and the position information  125  of the pinpoint information  121 . Specifically, the estimated position information calculating unit  104  calculates the distance from the position of the left-side start point house number  146 B to the position of the left-side end point house number  147 B, thereafter calculates the distance of one segment (for example, from the house number “1” to “3”, etc.), and determines the position one segment remote from the left-side endpoint house number  147 B along the link shape  153  of the range information  141 A as the position of the left-side start point house number  146 C. 
     In a case that the positions from the left-side start point house number  146 A of “1” to the left-side end point house number  147 A of “99” are not equally spaced, that the space for one segment from the house number “1” to the house number “15” is longer than other spaces, and that the house number of the inputted address information is “19”, as shown in  FIG. 6A , the estimated position information calculating unit  104  determines the position which is remote from the start point house number “17” in the divided range information  141 C by the one segment of the divided range information  141 C as the estimated position. 
     It is noted that, if the estimated position information calculating unit  104  does not generate the divided range information  141 , the position of the house number “19” of the inputted address information is estimated as the position indicated by  FIG. 6B . In this case, since the positions from the left-side start point house number  146 A of “1” to the left-side end point house number  147 A of “99” are not equally spaced, a larger error takes place. 
     However, even if the house numbers are not equally allocated, if the estimated position calculating unit  104  divides the range information  141  by using the pinpoint information  121 , the range of the house numbers of the left-side range information  145  of the divided range information  141  is narrowed, and the error between the estimated position and the actual position can be reduced. 
     [Position Information Detecting Process] 
     Next, “the position information detecting process” according to this embodiment will be described. 
     In the position information detecting process according to this embodiment, the position information detecting apparatus  300  detects the position information corresponding to the inputted address information by using the pinpoint information  121  and the range information  141 . 
       FIG. 7  shows a flowchart of the position information detecting process according to this embodiment. This process is realized by the system controller  20  in the position information detecting apparatus  300 , which executes a program prepared in advance. 
     First, when the system controller  20  detects that a user inputs an address by the input operation and instructs the address search (step S 1 ), the pinpoint information searching unit  101  searches the pinpoint information DB  120  for the pinpoint information  121  which coincides with the first address part of the inputted address information inputted via the input device  60  (step S 2 ). 
     Then, the pinpoint information detecting unit  102  detects the pinpoint information  121  having the second address part which coincides with the second address part of the inputted address information, from the pinpoint information  121  searches by the pinpoint information searching unit  101  (step S 3 ). 
     When the pinpoint information detecting unit  102  detects the pinpoint information  121  having the second address part which coincides with the second address part of the inputted address information (step S 4 ; Yes), the detection-object position information determining unit  105  determines the position information  125  of the pinpoint information  121  detected by the pinpoint information detecting unit  102  as the position information of the detection-object (step S 5 ). 
     On the other hand, when the pinpoint information detecting unit  102  does not detect the pinpoint information  121  having the second address part which coincides with the second address part of the inputted address information (step S 4 ; No), the range information searching unit  103  searches the range information DB  140  for the range information having the first address part which coincides with the first address part of the inputted address information (step S 6 ). 
     When the range information  141  searched by the range information searching unit  103  does not include the range information  141  including the inputted address information in the range information of the address information (step S 7 ; No), it means that the position information corresponding to the inputted address information cannot be determined. Therefore, the system controller  20  performs the warning requesting the user to input again (step S 8 ). 
     On the other hand, when the range information  141  searched by the range information searching unit  103  includes the range information  141  including the inputted address information in the range information of the address information (step S 7 ; Yes), the estimated position information calculating unit  104  determines the start point house number and the end point house number of the range information  141  including the inputted address information in the range information of the address information as the positions of the both end points of the link shape  153 , and determines the position information corresponding to the second address part of the inputted address information in a case that the house numbers between the start point house number and the end point house number are arranged in an equally-spaced manner along the link shape  153  as the estimated position information (step S 9 ). 
     The detection-object position information determining unit  105  determines the estimated position information calculated by the estimated position information calculating unit  104  as the position information of the detection-object (step S 10 ). 
     The map searching unit  106  searches the map based on the position information determined by the detection-object position information determining unit  105 , and the displays the search result (step S 11 ). Thus, the system controller  20  ends the process. 
     As described above, the position information detecting apparatus  300  can specify the position information corresponding to the inputted address information, without estimating the position using the range information  141 , if it can search the pinpoint information  121  having the address information coinciding with the inputted address information. Also, if there is no pinpoint information  121  having the address information coinciding with the inputted address information, the position information detecting apparatus  300  estimates the position of the inputted address information by using the range information  141 . 
     [Position Information Detecting Process (Range Information Division)] 
     Next, the position information detecting process (range information division) according to this embodiment will be described. 
     In the position information detecting process (range information division), the position information detecting apparatus  300  detects the position information corresponding to the inputted address information by using the divided range information  141 . 
       FIG. 8  shows a flowchart of the position information detecting process (range information division) according to this embodiment. This process is realized by the system controller  300  in the position information detecting apparatus  300 , which executes a program prepared in advance. 
     First, when the system controller  20  detects that a user inputs an address by the input operation and instructs the address search (step S 21 ), the pinpoint information searching unit  101  searches the pinpoint information DB  120  for the pinpoint information  121  which coincides with the first address part of the inputted address information inputted via the input device  60  (step S 22 ). 
     Then, the pinpoint information detecting unit  102  detects the pinpoint information  121  having the second address part which coincides with the second address part of the inputted address information, from the pinpoint information  121  searched by the pinpoint information searching unit  101  (step S 23 ). 
     When the pinpoint information detecting unit  102  detects the pinpoint information  121  having the second address part which coincides with the second address part of the inputted address information (step S 24 ; Yes), the detection-object position information determining unit  105  determines the position information  125  of the pinpoint information  121  detected by the pinpoint information detecting unit  102  as the position information of the detection-object (step S 25 ). 
     On the other hand, when the pinpoint information detecting unit  102  does not detect the pinpoint information  121  having the second address part which coincides with the second address part of the inputted address information (step S 24 ; No), the range information searching unit  103  searches the range information DB  140  for the range information having the first address part which coincides with the first address part of the inputted address information (step S 26 ). 
     The estimated position information calculating unit  104  divides the range information  141  searched by the range information searching unit  103  by using the pinpoint information  121  searched by the pinpoint information searching unit  101  (step S 27 ). 
     Here, if there is no divided range information  141  including the inputted address information in the range information of the address information (step S 28 ; No), it means that the position information corresponding to the inputted address information cannot be determined. Therefore, the system controller  20  performs the warning requesting the user to input again (step S 29 ). 
     On the other hand, when the divided range information  141  includes the divided range information  141  including the inputted address information in the range information of the address information (step S 28 ; Yes), the estimated position information calculating unit  104  determines the start point house number and the end point house number of the divided range information  141  including the inputted address information in the range information of the address information as the positions of the both endpoints of the link shape  153 , and determines the position information corresponding to the second address part of the inputted address information in a case that the house numbers between the start point house number and the end point house number are arranged in an equally-spaced manner along the link shape  153  as the estimated position information (step S 30 ). 
     The detection-object position information determining unit  105  determines the estimated position information calculated by the estimated position information calculating unit  104  as the position information of the detection-object (step S 31 ). 
     The map searching unit  106  searches the map based on the position information determined by the detection-object position information determining unit  105 , and the displays the search result (step S 32 ). Thus, the system controller  20  ends the process. 
     As described above, if there is no pinpoint information  121  having the address information coinciding with the inputted address information, the position information detecting apparatus  300  generates the divided range information by using the pinpoint information  121  and the range information  141 , and estimates the position by using the divided range information  141 . Thereby, the position information detecting apparatus  300  narrows range of the house numbers of the range information  141 . The position information detecting apparatus can improve the detection accuracy of the position information by estimating the inputted position information by using the divided range information  141 , in comparison with the case in which the position information is estimated by using non-divided range information  141 . 
     As described above, the position information detecting apparatus  300  includes: a pinpoint information storing means which stores pinpoint information including address information including a first address part and a second address part, and position information corresponding to the address information; a range information storing means which stores range information including range information of the address information and position information corresponding to the range information of the address information; a pinpoint information searching means which searches the pinpoint information storing means for the pinpoint information including the first address part which coincides with the first address part of inputted address information; a pinpoint information detecting means which detects the pinpoint information including the second address part which coincides with the second address part of the inputted address information; a range information searching means which searches the range information storing means for the range information including the first address part which coincides with the first address part of the inputted address information; an estimated position information calculating means which calculates estimated position information by estimating the position information corresponding to the inputted address information, by using the range information searched by the range information searching means and the pinpoint information searched by the pinpoint information searching means; and a detection-object position information determining means which determines the position information of the pinpoint information as a detection-object position information when the pinpoint information detecting means detects the pinpoint information, and determines the estimated position information calculated by the estimated position information calculating means as the detection-object position information when the pinpoint information detecting means does not detect the pinpoint information. 
     As described above, the position information detecting apparatus determines the position information of the pinpoint information as the detection-object position information if the pinpoint information coinciding with the inputted address information exists, and estimates the inputted position information by using the pinpoint information coinciding with the first address part of the inputted address information and the range information coinciding with the first address part of the inputted address information if the pinpoint information coinciding with the inputted address information does not exist. 
     Therefore, since the position information detecting apparatus estimates the position of the inputted address information from the range information including the inputted information in the address range, by using the pinpoint information storing the position information corresponding to the address information, the estimation accuracy of the position information can be improved, in comparison with the case in which the position of the inputted address information is estimated by using only the range information. 
     Other Embodiments 
     In the above embodiment, the position information detecting apparatus  300  is applied to the navigation apparatus  200 . However, the present invention is not limited to this embodiment, and may be applied to various apparatuses such as a personal computer. 
     In the above embodiment, the position information  125  in the pinpoint information  121  is the latitude and longitude information. However, the present invention is not limited to this embodiment. The position information  125  may include three information, i.e., “link shape”, “position on the link” and “left/right information”. The “link shape” has the same meaning as the link shape  153  in the range information  141 . The “position on the link” indicates the position on the link by the percentage, wherein the start point and the end point of the vector data sequence of the “link shape” is expressed by “0%” and “100%”, respectively. 
     The method of determining the “position on the link” is to draw a vertical line with respect to the nearby link from the latitude and longitude position of the facility to determine the cross point as the position on the link. Since the navigation apparatus has an aim to guide to the road near the facility, the above expression is effective. The “left/right” information designates whether the corresponding facility is located on the left or right side of the link. 
     In the above position information detecting process and the position information detecting process (range information division), the detection of the position information is performed after all the “city name”, the “street” and the “house number” are inputted by the user, the present invention is not limited to this embodiment. In an example, the input of the city name can be omitted to specify the position for all the cases in which the street and the house number coincide, and then the input of the city name may be requested thereafter. 
     The above embodiment is applied to the address information including the city name, the street and the house number, the present invention is not limited to this embodiment, and may be applied to the address information of other format. For example, if the object area of the navigation apparatus  200  is broad, plural cities having the same city name may exist. In this case, an area name broader than the city may be designated to specify the city. In an actual example, the city “Detroit” exists in the state of Michigan and the state of Illinois in the United States. In this case, the “state” may be designated. As another example, the post-code may be used in place of the city name. 
     In the above embodiment, the estimated position information calculating unit  104  generates the divided range information  141  by using the pinpoint information  121 , and estimates the position information of the inputted address information by using the divided range information  141 . However, the present invention is not limited to this, and the position information of the inputted address may be estimated by using the pinpoint information  121  and the range information  141 . 
     In the above embodiment, in the position information detecting process (range information division), the estimated position information calculating unit  104  detects the divided range information  141  including the inputted address information in the range information of the address information, after dividing the range information  141 . However, the present invention is not limited to this. The range information  141  may be divided after the range information  141  including the inputted address information in the range information of the address information is detected. 
     In the above embodiment, the estimated position information calculating unit  104  in the position information detecting apparatus  300  generates the divided range information  141  by dividing the range information  141  by using the pinpoint information  121 , and estimates the position information corresponding to the inputted address information by using the divided range information  141 . However, the present invention is not limited to this embodiment. The divided range information  141 , divided in advance by using the pinpoint information  121 , may be prepared in the range information DB  140 , and the estimated position information calculating unit  104  may estimate the position information corresponding to the inputted address information by using the divided range information  141 . 
     INDUSTRIAL APPLICABILITY 
     This invention can be used for an apparatus which detects the position information corresponding to the address information.