JPWO2006018979A1 - Information recording medium, map data update device - Google Patents

Abstract

The information recording medium (100) is an information recording medium used for updating map data, and (i) an acquisition program (111) for acquiring difference data (123) used for updating map data. (Ii) an update program (112) for updating the map data based on the acquired difference data, a read-only first area (104) recorded in advance, and the acquired difference data And a second area (106) for recording.

Description

  The present invention relates to a technical field of an information recording medium such as a DVD, and a map data updating apparatus that performs a map data updating process using such an information recording medium.

  At present, navigation devices, particularly vehicle navigation devices, are widely used, and their development is progressing day by day. The navigation device displays the current position of a navigation target object such as a host vehicle on a display device such as a display using map data stored in a CD-ROM, DVD-ROM or hard disk, and guides a route, etc. Provides various functions.

  Moreover, there exists a technique which enables update of map data by enabling rewriting of the map data used for such a navigation apparatus (refer patent document 1). In addition, there is a technology that can use map data reflecting the latest road data by rewriting map data with difference data. Here, “difference data” related to map data refers to data portions (map data portions) that are different from each other between two map data before and after update. In this technology, the map data produced at a given point in time is used as original data, and changes in actual road conditions from the time of production are separately created as difference data. When actually using the map data, The change in road conditions indicated by the difference data is reflected in the data. By using such difference data, map data reflecting the latest road conditions can be used relatively efficiently.

JP 2002-5669 A

  However, in the technique for updating the map data in this way, it is necessary to obtain a recording medium on which the difference data is recorded every time the user updates the map data. If this recording medium is a write-once type recording medium such as a DVD-R, for example, it is necessary to obtain a new recording medium every time it is updated, which has the problem of increasing the burden on the user. On the other hand, if this recording medium is a rewritable recording medium such as a DVD-RW, it is sufficient to prepare a single recording medium. However, each time it is updated, it is necessary to record (or overwrite) the difference data on the recording medium based on the user's own operation and the like.

  The present invention has been made in view of, for example, the above-described conventional problems. For example, an object of the present invention is to provide an information recording medium and a map data update device that can update map data relatively easily.

(Information recording medium)
The information recording medium of the present invention is an information recording medium used for updating map data in order to solve the above-mentioned problem, and (i) acquisition for acquiring difference data used for updating the map data A read-only first area in which an update program, (ii) an update program for updating the map data based on the acquired difference data, and the acquired difference data are recorded 2nd area for doing.

  According to the information recording medium of the present invention, each of the acquisition program and the update program is recorded in advance in the first area, for example, by embossed pits or recording marks. The first area is read-only, and no new data can be recorded. On the other hand, in the second area, difference data indicating the update status of the map data is recorded. In particular, in the second area, differential data acquired by executing the acquisition program is recorded.

  Then, if the information recording medium is loaded on, for example, a data update device described later, the update program recorded in the first area is executed, and the map data is updated using the difference data recorded in the second area. Is done. In addition, the recording of the difference data in the second area (that is, the acquisition of the difference data) can be performed by loading the information recording medium into a data acquisition device, which will be described later, and the acquisition program recorded in the first area. It can be executed by being executed. For this reason, if the update program or the like is executed, the update of the map data can be completed, so that the user can update the map data with less burden. That is, the user can enjoy a great advantage that there is no need to perform special operations and processing (or troublesome operations and settings).

  In addition, if the difference data recorded in the second area is appropriately rewritten, the map data can be repeatedly updated a plurality of times using the same information recording medium. Therefore, it is not necessary to obtain a new information recording medium every time the map data is updated. Thereby, since the information recording medium is not discarded every time the map data is updated, there is an advantage that the global environment is not adversely affected. Of course, it is needless to say that the rewriting of the difference data does not require the user to perform a special operation or processing by the operation of the acquisition program or the like. In addition, since the update program is recorded in the read-only first area, it has an advantage that it is not tampered with.

  As a result, according to the information recording medium of the present invention, it is possible to update the map data relatively easily and appropriately.

  According to one aspect of the information recording medium of the present invention, the difference data is encrypted and recorded in the second area, and the encrypted data is decrypted in the first area. A decryption program is recorded in advance.

  According to this aspect, when the decryption program recorded in the first area is executed, the differential data is decrypted without performing any special operation or processing. Therefore, it is possible to reduce the burden on the user who updates the map data using the information recording medium. Furthermore, the update program may be configured to be able to execute differential data encryption processing.

  In addition, since the difference data is recorded in the second area in an encrypted state, the difference data is not recorded unless the decryption program records the difference data on the information recording medium recorded in the first area. Cannot be decrypted. Therefore, even if there is a user who has illegally acquired the encrypted difference data, the difference data cannot be used, so that it is possible to effectively prevent unauthorized copying or outflow of the difference data. it can.

  Note that, from the viewpoint of preventing this illegal duplication or outflow, it is preferable that the decoding of the difference data is set to be executable only by the update program recorded in the first area.

(Map data update device)
In order to solve the above-mentioned problem, a map data update device of the present invention is a map data update device that updates map data using the above-described information recording medium of the present invention (including various aspects thereof). A storage means for storing the map data; a reading means for reading the update program and the difference data recorded on the information recording medium; and executing the update program to obtain the read difference data. And updating means for updating the map data stored in the storage means.

  According to the map data update device of the present invention, the difference data and the update program are read by the operation of the reading means. Then, by executing the read update program, the update of the map data is performed based on the read difference data by the operation of the update means. Therefore, it is possible to update the map data relatively easily and appropriately while enjoying the various benefits of the information recording medium according to the present invention described above.

  Incidentally, in response to the various aspects of the information recording medium of the present invention described above, the map data updating apparatus of the present invention can also adopt various aspects.

  In one aspect of the map data updating device of the present invention, the difference data is encrypted and recorded in the second area, and the encrypted difference data is decrypted in the first area. A decryption program to be recorded is recorded in advance, and further includes decryption means for decrypting the encrypted difference data by executing the decryption program, and the update means is configured to decrypt the decrypted data. The map data is updated based on the difference data.

  According to this aspect, when the decryption program is executed, the differential data is decrypted by the operation of the decryption means without any special operation or processing by the user. Therefore, even if the difference data is encrypted in order to prevent unauthorized duplication or outflow of the difference data, the map data can be updated relatively easily and appropriately.

  According to another aspect of the map data update device of the present invention, the map data update device further includes a selection unit that selects a part of the difference data, and the update unit includes the selected part of the difference data. The map data is updated based on the portion.

  According to this aspect, if the difference data includes unnecessary data, a part of the data part necessary for the update is selected by the operation of the selection unit, and based on the part of the data part, the map data Updates are made. Therefore, it is not necessary to perform unnecessary updating using unnecessary difference data, and the convenience for the user can be further improved.

  These effects and other advantages of the present invention will become more apparent from the embodiments described below.

  As described above, the information recording medium of the present invention includes the read-only first area in which the update program is recorded in advance and the second area in which the difference data is recorded. Accordingly, it is possible to update the map data relatively easily and appropriately.

  In addition, according to the map data updating apparatus of the present invention, the reading means and the updating means are provided. Accordingly, it is possible to update the map data relatively easily and appropriately.

It is a schematic plan view of the optical disc according to the above embodiment. It is a data structure figure which shows notionally the data structure of the optical disk (especially reproduction-only area) based on a present Example. FIG. 2 is a schematic plan view of an optical disc after predetermined difference update data is recorded on the optical disc according to the embodiment. It is a data structure figure which shows notionally the data structure of the said optical disk (especially recordable area) after recording predetermined difference update data with respect to the optical disk which concerns on a present Example. It is explanatory drawing which shows notionally the basic composition of the map data update system which concerns on a present Example. It is a flowchart which shows notionally the flow of the operation | movement regarding download of difference update data among the update operations of the map data in the map data update system which concerns on a present Example. It is a flowchart which shows notionally the flow of actual update operation | movement among the update operations of the map data in the map data update system which concerns on a present Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Optical disk 104 Read-only area 106 Recordable area 111 Automatic download program 112 Automatic update program 113 Decoding program 114 Initial difference update data 121 Area code 122 Version code 123 Difference update data 200 Data acquisition apparatus 201 CPU
203 Optical disk drive 300 Navigation device 301 CPU
303 Optical disk drive 304 Hard disk 500 Map data update system

  Hereinafter, the best mode for carrying out the present invention will be described for each embodiment in order with reference to the drawings.

  Embodiments of the present invention will be described below with reference to the drawings.

(Information recording medium)
First, with reference to FIG. 1 to FIG. 4, an optical disc 100 that is an embodiment of the information recording medium of the present invention will be described. FIG. 1 is a schematic plan view of the optical disc 100 according to the present embodiment, and FIG. 2 is data conceptually showing the data structure of the optical disc 100 according to the present embodiment (particularly, the reproduction-only area 104). FIG. 3 is a structural diagram, and FIG. 3 is a schematic plan view of the optical disc 100 after predetermined difference update data is recorded on the optical disc 100 according to the present embodiment. FIG. 4 is according to the present embodiment. 3 is a data structure diagram conceptually showing the data structure of the optical disc 100 (particularly, the recordable area 106) after recording predetermined difference update data on the optical disc 100. FIG.

  As shown in FIG. 1, the optical disc 100 according to the present embodiment has a disk shape with a diameter of about 12 cm, for example, like a CD or DVD. A read-only area 104 (that is, a specific example of “first area” in the present invention) in which various programs to be described later are recorded in advance is provided on the relatively inner periphery side of the optical disc 100. These various programs are recorded in advance in the read-only area 104 by using, for example, embossed pits having a predetermined physical shape or premarks formed by irradiating the recording surface with laser light.

  On the relatively outer peripheral side of the optical disc 100, a recordable area 106 (that is, in the present invention) in which data can be recorded only once or a plurality of times by various recording methods such as a magneto-optical method and a phase change method. A specific example of “second area” is provided. In particular, the recordable area 106 is preferably configured such that various data can be recorded a plurality of times (that is, rewritable) like a recording area such as a DVD-RW.

  The optical disc 100 according to the present embodiment is particularly used for updating map data used by, for example, a navigation device. The update of the map data is performed by the operation of various programs recorded in the reproduction-only area 104. That is, for example, it is used to update map data including information indicating roads, intersections, buildings, etc., to newer (or latest) map data. In this embodiment, a difference update indicating a newly added road, a lost road, or a road with some changes compared to the map data creation time (or a predetermined time). Map data is updated using the data 123 (see FIG. 4).

  In the reproduction-only area 104, as shown in FIG. 2, an automatic download program 111, an automatic update program 112, and a decryption program 113 are recorded as various programs.

  The automatic download program 111 constitutes one specific example of the “acquisition program” in the present invention, and is a program executed to automatically download the difference update data 123 from, for example, a map data update server described later. is there. In addition, the downloaded difference update data 123 may be configured to be recordable in the recordable area 106.

  The automatic update program 112 constitutes a specific example of the “update program” in the present invention, and actually updates (updates) the map data using the difference update data 123 recorded in the recordable area 106. A program that is executed to do. In other words, the program is executed to create new (or latest) map data by combining the difference update data 123 with the map data used by the navigation device or the like.

  The decryption program 113 constitutes a specific example of the “decryption program” in the present invention, and is a program executed to decrypt the difference update data 123 that has been encrypted and recorded in the recordable area 106. is there. The difference update data 123 may be already encrypted when the automatic download program 111 is downloaded, or by the operation of the decryption program 113 (or encryption program) recorded in the reproduction-only area 104, It may be configured to be encrypted after being downloaded.

  In the recordable area 106, for example, the difference update data 123 downloaded by the automatic download program 111 described above is recorded. However, the difference update data 123 may be recorded in advance when the optical disc 100 is manufactured, or may be configured to be recorded after the user obtains it by himself.

  For example, when predetermined difference update data 123 is recorded in this recordable area 106 (or a part thereof), for example, as shown in FIG. 3, a part of the inner circumference side of the recordable area 106 is recorded. The difference update data 123 is recorded in the recording area 106a, and the remaining part of the recording area 106b is not recorded.

  As shown in FIG. 4, the area code 121 and the version code 122 may be recorded in the recordable area 106 in addition to the difference update data 123.

  The area code 121 is information that can identify the area of the map data updated by the difference update data 123. For example, when Hokkaido map data is updated by one difference update data 123, in addition to the one difference update data 123, an area code 121 indicating that the difference update data 123 is data related to Hokkaido is displayed. It is recorded in the recordable area 106. Or when the map data of Tokyo 23 wards are updated by other difference update data 123, in addition to the other difference update data 123, it shows that the said difference update data 123 is data regarding Tokyo 23 wards. An area code 121 is recorded in the recordable area 106.

  The version code 122 is information indicating the version of the difference update data 123. That is, the content of the difference update data 123 can vary greatly depending on when the map data serving as the update reference is created and when the difference update data 123 is created. Therefore, the map data is preferably updated by selectively using the desired difference update data 123 based on the version code 122.

  By using such an optical disc 100, for example, old map data recorded on a hard disk or the like in the navigation apparatus can be updated to newer (or latest) map data. This makes it possible to perform more suitable navigation processing (for example, route search processing, route guidance processing, etc.) using newer (or latest) map data.

  Particularly in the present embodiment, the map data can be updated automatically and relatively easily by executing the automatic download program 111, the automatic update program 112, and the decryption program 113 recorded in the reproduction-only area 104. . Therefore, for example, the map data can be updated appropriately without causing a user such as a navigation device to perform a special operation or process, or to place an excessive burden. In other words, a user-friendly service can be provided to the user.

  In addition, since the difference update data 123 is recorded in the recordable area 106, the difference update data 123 once recorded can be erased and new difference update data 123 can be recorded many times. In other words, it is possible to update the map data that is expected to be frequently updated a plurality of times by using one optical disk 100. For this reason, it is not necessary to obtain an optical disc for updating every time map data is updated, which is convenient for the user. Further, it is not necessary for the producer of map data (that is, the manufacturer) to manufacture an optical disc for updating every time map data is updated, which is excellent in terms of cost and labor. Further, the map data can be updated a plurality of times by repeatedly using one optical disk 100 without discarding the optical disk 100 by one update. For this reason, the amount of waste can be reduced, and it has a great advantage that it does not adversely affect the global environment.

  In addition, the difference update data 123 is downloaded in an encrypted state and recorded in the recordable area 106. In order to decrypt the encrypted difference update data 123, the decryption program 113 recorded in the reproduction-only area 104 is required. Therefore, even if there is a person who obtains the difference update data 123 illegally, if the difference update data 123 is not recorded on the regular optical disc 100 in which the decryption program 113 is recorded in advance, the decryption cannot be performed. As a result, the map data cannot be updated. As a result, it is possible to effectively prevent unauthorized use and unauthorized duplication of the differential update data 123.

  At this time, the encrypted difference update data 123 can be decrypted only by the decryption program 113 recorded in advance in the reproduction-only area 104 from the viewpoint of effectively preventing unauthorized use and unauthorized duplication. Depending on other programs, it is preferable that the decryption is impossible.

  In addition, the automatic download program 111, the automatic update program 112, and the decryption program 113 are recorded in the reproduction-only area 104 in advance. For this reason, it is possible to suitably prevent the inconvenience that these various programs are rewritten into a state where unauthorized use is possible by a malicious user.

  The automatic download program 111, the automatic update program 112, and the decryption program 113 may be recorded in the recordable area 106. Further, from the viewpoint of simply reducing the burden on the user when updating the map data, it is sufficient if the automatic download program 111, the automatic update program 112, and the decryption program 113 are recorded in advance. Therefore, the optical disk may be provided with only the recordable area 106 and without the reproduction-only area 104. Alternatively, it is an optical disk that has only the reproduction-only area 104 and does not have the recordable area 106, and is an optical disk on which the automatic download program 111, the automatic update program 112, the decryption program 113, the difference update data 123, etc. are recorded in advance. Also good.

  Further, as shown in FIG. 2, the initial difference update data 114 may be recorded in the reproduction-only area 104 in advance. The initial difference update data 114 compares the creation time (or predetermined time) of the map data with the time when the optical disc 100 according to the present embodiment is manufactured, newly added roads, lost roads, etc. Or it is difference update data which shows the road etc. to which some change was added. Furthermore, in the present embodiment, the initial difference update data 114 is recorded in the reproduction-only area 104, but may be configured so as to be recorded in advance in the recordable area 106.

  In addition, the arrangement and size of the reproduction-only area 104 and the recordable area 106 shown in FIG. 1 are merely specific examples, and needless to say, the arrangement is not limited to this. For example, the read-only area 104 may be provided on the relatively outer peripheral side, and the recordable area 106 may be provided on the relatively inner peripheral side, or may be configured in any other manner. Each of the recordable areas 106 may be provided. Further, a plurality of reproduction-only areas 104 and a plurality of recordable areas 106 may be provided.

  Further, the optical disc 100 according to the present embodiment is not limited to an optical disc having a single recording layer, and may be two-layer single-sided (ie, dual layer) or double-layer double-sided (ie, dual-layer double side). Furthermore, the optical disc is not limited to an optical disc having two recording layers, and may be a multilayer optical disc having three or more layers.

  In the above-described embodiment, since the difference update data 123 is acquired by downloading, the automatic download program 111 is recorded in the reproduction-only area 104, but the mode of acquiring the difference update data is limited to download. Is not to be done. For example, the difference update data 123 may be obtained from another information recording medium such as a hard disk. At that time, instead of the automatic download program 111, for example, an automatic copy program or the like may be recorded in the reproduction-only area 104 in advance.

(Map data update system)
Subsequently, a map data update system for updating map data (that is, for example, download of difference update data or upload of map data) using the optical disc 100 according to the above-described embodiment will be described with reference to FIGS. While explaining.

(1) Basic Configuration First, the map data update system 500 will be described with reference to FIG. FIG. 5 is an explanatory diagram conceptually showing the basic structure of the map data updating system 500 according to this embodiment.

  As shown in FIG. 5, the map data update system 500 includes a data acquisition device 200, a navigation device 300, and a map data update server 400.

  The data acquisition device 200 includes, for example, a personal computer and a workstation, and is configured to be able to download the differential update data 123 from the map data update server 400. More specifically, the data acquisition apparatus 200 includes a CPU 201, a memory 202, an optical disk drive 203, and an external interface 204.

  The CPU 201 is connected to the memory 202, the optical disk drive 203, and the external interface 204 via a bus, and controls the entire data acquisition apparatus 200 by giving instructions to various control means. In particular, when the automatic download program 111 recorded in advance on the optical disc 100 is executed on the CPU 201, the difference update map data 123 can be downloaded from the map data update server 400 via the external interface 204.

  The memory 202 includes a RAM area for temporarily storing data, for example, in the entire data processing in the data acquisition apparatus 200. Further, the memory 202 includes a ROM area in which a program (that is, firmware) for performing an operation as the data acquisition device 200 is stored. In particular, the automatic download program 111 recorded in advance on the optical disc 100 is temporarily stored in the RAM area of the memory 202 during execution.

  The optical disc drive 203 records various data on the optical disc 100 or reads various data recorded on the optical disc 100. In particular, the automatic download program 111 or the like recorded in advance on the optical disc 100 is read, and the downloaded difference update map data 123 is recorded on the optical disc 100.

  The external interface 204 includes, for example, a modem, a DSU, a router, and the like, and is configured to be able to execute transmission / reception of various data with the map data update server 400 via a wired or wireless network capable of bidirectional communication. .

  The navigation device 300 is configured to be able to execute navigation processing for automobiles, for example. And it is comprised so that the map data currently recorded on the hard disk etc. with which the said navigation apparatus 300 is provided can be updated using the difference update data 123. FIG. More specifically, the navigation device 300 includes a CPU 301, a memory 302, an optical disk drive 303, a hard disk 304, and a navigation processing unit 305.

  The CPU 301 constitutes one specific example of “update means” and “decryption means” in the present invention, and is connected to the memory 302, the optical disk drive 303, the hard disk 304, and the navigation processing unit 305 via a bus, and various control means. The navigation device 300 is controlled as a whole. In particular, the automatic upload program 112 recorded in advance on the optical disc 100 is executed on the CPU 301 so that the map data can be updated using the difference update map data 123 recorded on the optical disc 100. Yes. Further, the decryption program 113 recorded in advance on the optical disc 100 is executed on the CPU 301 so that the encrypted difference update map data 123 recorded on the optical disc 100 can be decrypted. .

  The memory 302 includes a RAM area and a ROM area in the same manner as the memory 202 included in the data acquisition device 200 described above. In particular, the automatic upload program 112 and the decryption program 113 recorded in advance on the optical disc 100 are temporarily stored in the RAM area of the memory 202 during execution. The memory 302 may be used for temporarily storing data during the navigation process.

  The optical disk drive 303 constitutes one specific example of the “reading unit” in the present invention. Like the optical disk drive 203 provided in the above-described data updating apparatus, various types of data are recorded on the optical disk 100 or recorded on the optical disk 100. Read various recorded data. In particular, the automatic upload program 111, the decryption program, or the difference update map data 123 recorded on the optical disc 100 is read.

  The hard disk 304 constitutes a specific example of “storage means” in the present invention, and records map data actually used for navigation processing. The map data may be map data conforming to the KIWI format including, for example, node data indicating points on the map and link data indicating a relationship between at least two points.

  The navigation processing unit 305 includes, for example, a GPS processing unit, an independent positioning processing unit, a route search processing unit, a route guidance processing unit, and the like, and performs various navigation processing using updated map data recorded on the hard disk 304. Is configured to run. Note that the navigation processing unit 305 may be configured to be integrated with the CPU 301.

  Note that the data acquisition device 200 may be included in a part of the navigation device 300. That is, the navigation apparatus 300 may download the difference update data 123 and perform an update process.

  The map data update server 400 includes, for example, a large server such as a personal computer, a workstation, or a mainframe, and is configured to be able to distribute the difference update data 123 to the data acquisition device 200 (or the navigation device 300). . In addition, a difference update map data DB (database) 401 for storing the difference update data 123 is provided. The map data update server 400 and the data acquisition device 200 (or the navigation device 300) are connected by a wired or wireless network capable of bidirectional communication.

(2) Operation Example Next, the map data update operation will be described in more detail with reference to FIGS. 6 and 7. FIG. 6 is a flowchart conceptually showing the flow of the operation related to the download of the differential update data 123 in the update operation of the map data, and FIG. 7 is the flow of the actual update operation in the update operation of the map data. Is a flowchart conceptually showing.

  As shown in FIG. 6, when the difference update data 123 is downloaded, the optical disc 100 is first loaded into the optical disc drive 203 of the data acquisition device 200 (step S101). Subsequently, the automatic download program 111 recorded in the read-only area 104 of the loaded optical disc 100 is read by the operation of the optical disc drive 203 under the control of the CPU 201 (step S102).

  Subsequently, it is determined under the control of the CPU 201 whether or not the download of the difference update data 123 is actually started (step S103). For example, if the user gives an instruction to execute the download, it may be determined that the download is started.

  As a result of this determination, if it is determined that the download has not started yet (step S103: No), the difference update data 123 is not downloaded, and the process proceeds to step S107.

  On the other hand, when it is determined to start downloading (step S103: Yes), the automatic download program 111 read in step S102 is on the data acquisition device 200 (more specifically, on the CPU 201 included in the data acquisition device 200). The difference update data 123 is downloaded through the external interface 204 (step S104). That is, under the control of the CPU 201 in which the automatic download program 111 is executed, a download request is made from the data acquisition device 200 to the map data update server 400, and the difference update data 123 is received from the map data update server 400 correspondingly. It is transmitted to the data acquisition device 200. At this time, the difference update data 123 is preferably already encrypted. However, the data may be transmitted without being encrypted, and may be configured to be encrypted by the operation of the decryption program 113 on the data acquisition apparatus 200 side, for example.

  Then, the downloaded difference update data 123 is recorded in the recordable area 106 of the optical disc 100 by the operation of the optical disc drive 203 under the control of the CPU 201 executing the automatic download program 111 (step S105).

  Thereafter, it is determined whether or not the download is completed under the control of the CPU 201 (step S106). That is, it is determined whether or not all of the difference update data 123 to be downloaded has been downloaded.

  If it is determined that the download is not completed as a result of the determination (step S106: No), the process returns to step S104 again, and the download of the difference update data 123 and the recording to the optical disc 100 are continuously performed.

  On the other hand, when it is determined that the download has been completed (step S106: Yes), the optical disc 100 is ejected from the data acquisition device 200 (step S107).

  Subsequently, as shown in FIG. 7, when the map data recorded on the hard disk or the like of the navigation device 300 is actually updated, the optical disc 100 is first loaded into the optical disc drive 203 of the navigation device 300 (step S201). ).

  Subsequently, the automatic update program 112 recorded in the read-only area 104 of the loaded optical disc 100 is read by the operation of the optical disc drive 303 under the control of the CPU 301 (step S202).

  Subsequently, it is determined under the control of the CPU 301 whether to actually start updating (updating) the map data using the difference update data 123 (step S203). For example, if the user has issued an instruction to actually execute the update, it may be determined that the update of the map data is started.

  As a result of this determination, if it is determined that the update of the map data has not yet started (step S203: No), the map data is not updated using the difference update data 123, and the process proceeds to step S208.

  On the other hand, when it is determined that the update of the map data is actually started (step S203: Yes), the decoding program 113 recorded in the reproduction-only area 104 of the optical disc 100 is executed by the operation of the optical disc drive 303 under the control of the CPU 301. It is read (step S204). Subsequently, when the decryption program 113 is executed on the navigation device 300 (more specifically, on the CPU 301 included in the navigation device 300), the difference update data 123 recorded in the recordable area 106 of the optical disc 100 is updated. Decoding is performed (step S205).

  Thereafter, the automatic update program 112 read in step S202 is executed on the navigation device 300 (more specifically, on the CPU 301 included in the navigation device 300), and the difference update data 123 decrypted in step S205 is used. The map data already recorded on the hard disk 304 is updated (step S206). That is, for example, in the map data, the data portion corresponding to the point added, changed, or deleted indicated by the differential update map data 123 is rewritten and recorded on the hard disk 304 as new (or latest) map data. Is done.

  Subsequently, it is determined whether the update of the map data is completed under the control of the CPU 301 (step S207). As a result of this determination, when it is determined that the update of the map data is not completed (step S207: No), the process returns to step S204 again, and the update of the map data is continuously performed. On the other hand, when it is determined that the update of the map data has been completed (step S207: Yes), the optical disc 100 is ejected from the navigation device 300 (step S208).

  As described above, in order to update the map data, the user only needs to load the optical disc 100 into the data acquisition device 200 or the navigation device 300. Accordingly, it is possible to reduce the burden on the user when updating the map data, and to enjoy various benefits of the optical disc 100 according to the above-described embodiment.

  In addition, even if it does not update map data using the whole difference update data 123 currently recorded on the recordable area 106, for example, you may update selectively using a part. Specifically, for example, it is assumed that difference update data 123 relating to map data of Hokkaido and Kanto is recorded in the recordable area 123. At this time, if the user lives in Hokkaido, for example, the map data may be updated by selectively using the difference update data 123 regarding the map data of Hokkaido.

  The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit or idea of the invention that can be read from the claims and the entire specification. The map data update device is also included in the technical scope of the present invention.

The information recording medium and the map data update device according to the present invention can be used for a high-density optical disk such as a DVD, for example, and can be used for a map data update process using such a high-density optical disk.

Claims (5)

An information recording medium used for updating map data,
(i) an acquisition program for acquiring difference data used for updating the map data; and (ii) an update program for updating the map data based on the acquired difference data. A read-only first area,
An information recording medium comprising: a second area for recording the acquired difference data. The difference data is encrypted and recorded in the second area,
The information recording medium according to claim 1, wherein a decryption program for decrypting the encrypted difference data is recorded in the first area in advance. A map data update device that updates map data using the information recording medium according to claim 1,
Storage means for storing the map data;
Reading means for reading the update program and the difference data recorded in the information recording medium;
An updater for updating the map data stored in the storage means based on the read difference data by executing the update program. The difference data is encrypted and recorded in the second area, and a decryption program for decrypting the encrypted difference data is recorded in advance in the first area,
Further comprising decryption means for decrypting the encrypted difference data by executing the decryption program;
4. The map data update device according to claim 3, wherein the update means updates the map data based on the decoded difference data. Further comprising a selection means for selecting a part of the difference data.
The map data updating apparatus according to claim 3, wherein the updating means updates the map data based on the selected partial data portion of the difference data.

Images