JP5734528B2 - Map data storage device, map display device - Google Patents

Description

  The present invention relates to a map data storage device and a map display device using the map data storage device.

  Usually, since map data has a large amount of data, map data is managed by dividing a space in which map data including backgrounds and roads exist into rectangles of a predetermined range called a mesh.

  Further, in order to execute map display of map data, route search, and the like at high speed, map data management is performed by hierarchizing (layering) map data according to a reduced scale.

  In such a map data management method, names used between layers or between meshes of the same layer often overlap. Therefore, for example, in Patent Document 1, among the name data included in the map data, the name data common between layers or between meshes of the same layer is collected as common name data, thereby reducing the data amount of the entire map data. The technology to do is proposed.

JP 2004-126036 A

  However, the map data management method disclosed in Patent Document 1 does not disclose the data structure of the common name data and does not adopt a spatial management form, and thus there is a problem in accessibility to desired data. It was. For example, when acquiring a plurality of name data, there is a possibility that desired data may be scattered in the common name data, so access (disk access when the common name data is stored on the disk) is performed. There is a problem that it occurs randomly and degrades the data access performance.

  In view of the above-described problems, an object of the present invention is to provide a map data storage device capable of efficiently accessing data and a map display device using the map data storage device.

The map data storage device of the present invention is hierarchized for each scale, partitioned into meshes of a size determined for each hierarchy, the mesh is identified by a mesh number for each hierarchy, and the lowest mesh is used as a reference mesh, In the map data, a map data storage unit that stores map data representing features for each mesh, and a name information storage unit that stores a name list composed of name records set for the features for displaying names, Each feature belongs to the mesh of each level from the lowest level to the level defined for each feature, and the name list is the name or symbol of the feature other than the highest level and below the predetermined division level other than the lowest level. Including a first name list that represents name information including at least one of the above and a second name list that represents name information of features above the division hierarchy, and the name represented by the first name list The information does not overlap each other, the name information represented by the second name list overlaps with the name information represented by the first name list, the first name record of the first name list includes the name information, and the name information of the feature. The maximum display hierarchy number indicating the maximum display hierarchy, which is the maximum display hierarchy, and if the maximum display hierarchy number exceeds the split hierarchy number indicating the split hierarchy, the split display maximum hierarchy number and the feature Is the data associated with the belonging reference mesh number indicating the belonging reference mesh that is the belonging reference mesh, and the first name list is a hierarchy in which the first name record indicates the divided display maximum hierarchy number and the divided display maximum hierarchy number. It is the list | wrist sorted by the priority of the division | segmentation display maximum hierarchy affiliation mesh number which is the affiliation mesh number in a certain division | segmentation display maximum hierarchy, and the affiliation reference | standard mesh number .

The name list stored in the name information storage unit of the map data storage device of the present invention represents name information including at least one of the names or symbols of features below a predetermined division hierarchy other than the uppermost layer and other than the lowermost layer. A first name list and a second name list representing name information of features above the division hierarchy are included. The first name record included in the first name list includes name information, a display maximum hierarchy number indicating a maximum display hierarchy, which is a maximum hierarchy in which feature name information is displayed, and a display maximum hierarchy number indicating a division hierarchy. The first name list is data associated with the division display maximum hierarchy number as the division hierarchy number when the division hierarchy number to be shown is exceeded and the affiliation reference mesh number indicating the affiliation reference mesh that is the reference mesh to which the feature belongs. Is the priority of the division display maximum hierarchy number, the division display maximum hierarchy affiliation mesh number which is the affiliation mesh number in the division display maximum hierarchy which is the hierarchy indicated by the division display maximum hierarchy number, and the affiliation reference mesh number. A sorted list.

  Therefore, when displaying a map, name information can be efficiently acquired from the name list. In particular, when displaying a map for meshes below the division hierarchy, it is possible to obtain necessary name records by referring to the meshes of the division hierarchy. The name can be acquired.

  Objects, features, and advantages of the present invention will become more apparent from the following detailed description and the accompanying drawings.

It is a block diagram which shows the structure of a navigation apparatus. It is a figure explaining the concept of the hierarchy of map data, and a mesh. It is a figure which shows the data structure of map information. It is a figure which shows the presence hierarchy range and display hierarchy range of a feature. It is a figure which shows the data structural example of a 1st name list. It is a figure which shows the specific example of a 1st name list. It is a figure showing the state where a feature straddles a plurality of meshes. It is a figure which shows the specific example of a 1st name list. It is a figure which shows the data structural example of a 1st name reference list. It is a figure which shows the specific example of a 1st name reference list. It is a data structural example of a 2nd name list. It is a figure which shows the specific example of a 2nd name list. It is an example of a data structure of a 2nd name reference list. It is a figure which shows the specific example of a 2nd name reference list. It is a flowchart which shows a map display process. It is a flowchart which shows a name acquisition process. It is a flowchart which shows a name drawing process. It is a figure which shows the specific example of background data.

<A. Embodiment 1>
<A-1. Configuration>
FIG. 1 is a block diagram showing a configuration of a navigation device 10 including a map data storage device and a map display device of the present invention. The navigation device 10 is mounted on a moving body such as a vehicle.

  The navigation device 10 includes an input unit 1, a position detection unit 2, a map information storage unit 3, a control unit 4, a display unit 5, and an audio output unit 6.

  The input unit 1 is a group of operation switches to which a user's operation and instruction are input, and a signal corresponding to the input operation and instruction is given to the control unit 4.

  The position detection unit 2 is a unit that detects the current position of a moving body on which the navigation device 10 is mounted, and is configured using, for example, a GPS (Global Positioning System) receiver, a vehicle speed sensor, an acceleration sensor, an angular velocity sensor, or the like. . Position information indicating the current position detected by the position detector 2 (hereinafter referred to as current position information) is given to the controller 4. The position detection unit 2 may be configured as a device different from the navigation device 10.

  The map information storage unit 3 is a storage medium for storing map information, and is realized by, for example, a hard disk drive, a DVD and its drive device, a Blu-ray disc and its drive device, a semiconductor memory, and the like.

  The control unit 4 uses the instruction signal from the input unit 1, the current position information from the position detection unit 2, and the map information read out from the map information storage unit 3 to perform various types of map display and route guidance around the current location. Perform the navigation process. The control unit 4 includes, for example, a processor, and includes a drawing processing unit 41 that performs drawing processing, a drawing memory 42 that stores drawing data of the drawing processing unit, and a display control unit 43 that controls display of the display unit 5. Yes.

  The display unit 5 displays the content drawn in the drawing memory 42 by the drawing processing unit 41 of the control unit 4 according to the control of the display control unit 43, and is configured by a liquid crystal display, for example.

  The voice output unit 6 presents information obtained as a result of various navigation processes by the control unit 4 to the user by voice. The information to be output by voice includes, for example, guidance information for performing guidance from the departure point to the destination according to the route to the destination obtained by the route search process on the map, and the destination information obtained by the search process. Facility information. The display unit 5 and the audio output unit 6 may be configured as devices different from the navigation device 10.

<A-2. Map information>
FIG. 3 shows the data structure of the map information stored in the map information storage unit 3. The map information has map management information, map data, feature name information, and search information for searching for various information. That is, the map information storage unit 3 is a map data storage unit that stores map data. The map data is managed in a hierarchical (layered) and meshed manner, and FIG. 2 shows the situation.

  FIG. 2 shows map data composed of four layers with layer numbers 0 to 3. The map data of each hierarchy shown here is map data for drawing the same range on the map at different scales. In the following description, the layer having the layer number n is also simply referred to as “layer n”.

  The map data of the hierarchy 3 consists of 4 meshes. The map data of level 2 is composed of 16 meshes obtained by dividing each mesh in the map data of level 3 into four. The map data of the hierarchy 1 consists of 64 meshes obtained by dividing each mesh in the map data of the hierarchy 2 into four. The map data of the hierarchy 0 is composed of 256 meshes obtained by dividing each mesh in the map data of the hierarchy 1 into four. In addition, although the square mesh is shown in FIG. 2, the shape of the mesh is not limited to this, and may be another shape such as a rectangle or a rhombus.

  In FIG. 2, the numbers in the square frames indicating the meshes represent the mesh numbers assigned to the meshes. A mesh number is assigned to zigzag and 0, 1, 2, 3 in the order of lower left, lower right, upper left, and upper right in the mesh of level 3. In the following, the mesh having the mesh number n is also simply referred to as “mesh n”.

  In the mesh of layer 2, mesh numbers are given in the order of mesh numbers of the corresponding meshes of the upper layer (hierarchy 3), and for the four meshes having the same mesh number of the corresponding mesh of the upper layer, the lower left, Mesh numbers are assigned in the order of lower right, upper left, and upper right. In this specification, “mesh corresponds” means that the two-dimensional coordinates of the mesh between different layers are the same.

  In the hierarchy number 2, mesh numbers 0, 1, 2, and 3 are assigned to the four meshes corresponding to the mesh 0 of the hierarchy number 3 in the order of lower left, lower right, upper left, and upper right. Also, mesh numbers 4, 5, 6, and 7 are assigned to the four meshes of the layer number 2 corresponding to the mesh 1 of the layer number 3 in the order of lower left, lower right, upper left, and upper right. Similarly, a mesh number 2 is assigned to the mesh of layer number 2 corresponding to the meshes 2 and 3 of layer number 3, as shown in FIG.

  A mesh number is assigned to the meshes of the hierarchy numbers 1 and 0 as well as the hierarchy number 2. Note that the mesh with the layer number 0 is also called a reference mesh, and the mesh number is called a reference mesh number.

  When the mesh number is assigned in this way, the mesh number of the mesh corresponding to the reference mesh in each layer can be obtained for an arbitrary reference mesh.

  Returning to FIG. 3, the information included in the map information will be described.

  The map management information includes version information indicating the version of map information, hierarchy management information for managing map data for each hierarchy, name management information for managing feature name information and search information, search information management information, and the like. Yes. The hierarchy management information has information such as the mesh number of each mesh, the storage position of the map data in the map information, and the data size for each hierarchy.

  The map data includes a map data header, road data, background data, route guidance data, and the like. That is, the map information storage unit 3 is a map data storage unit that stores map data.

  The map data header has information for managing each data in the map data.

  The road data is a set of road records provided corresponding to roads in the mesh. The road record has information representing the position, shape, type, and the like of the road in addition to the connection relationship between the roads and the feature ID for identifying the road.

  The background data is data representing each feature (background) other than the road in the mesh, and is a set of background records for displaying each background in the mesh. The background record includes information representing a feature ID for identifying the background, the position and shape of the background, the type of background, and the like. Examples of backgrounds include planes representing rivers, seas, etc., linear rivers, lines representing railways, points representing representative positions of facilities, and the like.

  The route guidance data includes information necessary for route guidance at an intersection or the like.

  The feature name information includes a name information header for managing various data in the feature name information, a name list representing the names of the features, a name reference list for referring to a desired name of the name list, and the like. The name list includes a first name list used for map display below a predetermined division hierarchy and a second name list used for map display above the division hierarchy. The name reference list includes a first name reference list for referring to the name of the first name list and a second name reference list for referring to the name of the second name list. Details of the name list and the name reference list will be described later.

  When the map is displayed, which level of map data is used is determined by the display scale. At the most detailed (narrow area) scale, the map data of the lowest layer mesh is used, and at the coarsest (wide area) scale, the map data of the uppermost layer mesh is used to display the map. For example, in FIG. 2, when the scale is 1 / 50,000 or more to 1 / 25,000, the hierarchy is 0, and when the scale is 1 / 100,000 or more to less than 1 / 50,000, the hierarchy 1 is 1/2000 or more to 1 The map data of the layer 2 is used when it is less than 100,000, and the mesh data of the layer 3 is used when it is 1/4000 or more to 1 / 200,000.

  The feature represented by the map data of each layer is obtained by thinning out the feature represented by the lower-level map data. The map data in the lowest layer represents all the features on the map, but up to which level (existing level range) differs depending on the features.

  For example, in the example of the map data shown in FIG. 2, the feature that exists only in the hierarchy 0, the feature that exists in the hierarchy 0, 1, the feature that exists in the hierarchy 0, 1, 2, and the hierarchy 0, 1, 2, 3 Divided into features that exist in

  In the map display, the shape of the feature and the name or symbol of the feature may be shown. A symbol is a mark (icon) that directly represents a feature. The display of feature names will be described below. However, when only the name of the feature is actually displayed, when only the symbol is displayed, both the name and the symbol may be displayed. .

  If the names are displayed for all the features present in each layer, the characters are overlapped and the map display becomes complicated, and therefore the display layer range of the names may be limited to a layer lower than the existing layer range of the features. For example, for a feature whose existence hierarchy range is 0 to 3, the display hierarchy range of the feature name may be 0 to 2. Thus, the feature existing hierarchy range and the name display hierarchical range do not necessarily match. The maximum hierarchy number in the display hierarchy range is called the display maximum hierarchy number.

  In addition, there may be a feature having no name such as a rural farm road.

  FIG. 4 shows the features and their names in each layer of the map data. The feature F0, the feature F5, and the feature F8 exist only in the hierarchy 0, and their names N0, N1, and N8 are displayed only in the hierarchy 0. Therefore, the existence hierarchy range is 0, and the display hierarchy range is 0. The maximum hierarchy number is 0. Since the features F1 and F6 exist in the hierarchy 0 and 1, and their names N1 and N6 are displayed in the hierarchy 0 and 1, the existence hierarchy range is 0 and 1, the display hierarchy range is 0 and 1, and the maximum display hierarchy number Is 1. The features F2 and F7 are present in the hierarchy numbers 0 to 2, and their names N2 and N7 are displayed in the hierarchy numbers 0 to 2, their existence hierarchy range is 0 to 2, and the display hierarchy range is 0 to 2. The maximum display hierarchy number is 2. Since the feature F4 exists in the hierarchy numbers 0 to 3 and the name N4 is displayed in the hierarchy numbers 0 to 3, the existence hierarchy range is 0 to 3, the display hierarchy range 0 to 3, and the maximum display hierarchy number is 3. The feature F3 exists in the hierarchy numbers 0 to 3, but since the name N3 is displayed in the hierarchy numbers 0 to 2, the existence hierarchy range is 0 to 3, the display hierarchy range is 0 to 2, and the display maximum hierarchy The number is 2.

<A-3. First name list>
FIG. 5 is a data configuration example of the first name list included in the feature name information. The first name list is an array of first name records representing names used for map display. The first name record is set on a one-to-one basis for the feature displaying the name, and is composed of a feature ID, a divided display maximum hierarchy number, a divided display maximum hierarchy belonging mesh number, an belonging reference mesh number, a name character string, and a symbol code. Is done. That is, the map information storage part 3 is also a name information storage part which memorize | stores the 1st name list which consists of a 1st name record.

  The feature ID is an identifier for identifying a feature for which name information is displayed. The division display maximum hierarchy number is a value obtained by applying a cap to the display maximum hierarchy number with a predetermined division hierarchy number. The division display maximum hierarchy affiliation mesh number represents the mesh number of the mesh to which the feature belongs in the hierarchy indicated by the division display maximum hierarchy number. The belonging reference mesh number represents the reference mesh number of the reference mesh to which the feature belongs. The name character string is a character string that represents the name of the feature and is displayed when the map is displayed. A plurality of languages may be supported by providing a language code and a character string in the language for each language. The symbol code is a code representing a feature symbol. Symbol image information (not shown) in the map information stores symbol image data provided corresponding to the symbol code, and the control unit 4 refers to the symbol code from the name list when the map is displayed. The corresponding image data is acquired and the symbol is displayed. Note that an invalid value (for example, 0xFFFF) is stored for a feature having no symbol.

  Since the relationship between meshes in each layer is determined in advance as shown in FIG. 2, the divided display maximum layer affiliation mesh number can be obtained from the display maximum layer number and affiliation reference mesh number. There is no need to hold. As will be described later, since the name records are sorted based on the divided display maximum hierarchy affiliation mesh number, it is necessary to obtain by calculation at that time, but it is not necessary to retain the data after sorting. However, when a name record is acquired from the first name list using a first name reference list to be described later, the name information needs to be linked to the divided display maximum hierarchy affiliation mesh number.

  A 1st name record is provided corresponding to the name or symbol of the feature which exists in the map data of the lowest layer. The first name records are sorted in descending order of the divided display maximum hierarchy number. The first name records having the same division display maximum hierarchy number are sorted in ascending order of the division display maximum hierarchy affiliation mesh number. Further, the first name records having the same divided display maximum hierarchy number and the same divided display maximum hierarchy belonging mesh number are sorted in ascending order of the belonging reference mesh number. That is, the first name list is a list sorted in the priority order of the divided display maximum hierarchy number, the divided display maximum hierarchy belonging mesh number, and the belonging reference mesh number.

  FIG. 6 shows a specific example of the first name record representing the feature shown in FIG. The division hierarchy number is 1. Corresponding to the features F0 to F8 of the hierarchy 0 shown in FIG. 4, first name records # 0 to # 8 are provided, and the first name records # 0 to # 8 are sorted according to the above rules. In the example shown in FIG. 6, the number of first name records is set to only nine for easy understanding, but actually, a larger number of first name records are provided. As the number of first name records increases, data reduction and access efficiency improvement, which are the effects of the present invention, become more prominent.

  Since the first name record is provided corresponding to the lowest layer feature, the first name record is duplicated and stored for the same feature even though the same feature appears across multiple hierarchies. The amount of data in the first name list is reduced. For example, in FIG. 4, the name N2 of the feature F2 is used redundantly in each of the layers 0 and 1, but is stored only once as the first name record # 1 in the first name list of FIG. The amount of data in the name list can be reduced.

  In addition, since the first name records are sorted according to the above-described rules, the first name records storing the names of the meshes in the respective layers are continuously arranged and stored in a distributed manner on the map information storage unit 3. Therefore, the control unit 4 can acquire the first name record necessary for displaying the mesh map at high speed.

  For example, consider the case where the names N1, N2, N3, N4, N6, and N7 of the features F1, F2, F3, F4, F6, and F7 shown in the mesh 0 of the hierarchy 1 in FIG. 4 are displayed. These names are respectively stored in the first name records # 0 to # 5 having the division display maximum hierarchy number 1 and the division display maximum hierarchy affiliation mesh number 0 in the first name list of FIG. Since the first name records are stored continuously, they can be acquired together.

  Consider the case where the names N0, N1, N2, N3, N4, and N8 of the features F0, F1, F2, F3, F4, and F8 shown in the mesh 0 of the hierarchy 0 in FIG. 4 are displayed. The names N0 and N8 are respectively stored in first name records # 6 and # 7 in the first name list of FIG. 6 where the divided display maximum hierarchy number is 0 and the divided display maximum hierarchy affiliation mesh number is 0. Since the first name records are stored continuously, they can be acquired together. The names N1 to N4 are respectively stored in the first name records # 0 to # 4 in the first name list of FIG. 6 where the divided display maximum hierarchy number is 1 and the divided display maximum hierarchy affiliation mesh number is 0. Since these first name records are stored continuously, they can be acquired together.

  Up to this point, the name record has been described for the case where a feature is included in one reference mesh. When a feature belongs across a plurality of reference meshes, one first name record is provided for this feature, and one of the reference meshes that the feature straddles is selected and the first name record Use the belonging reference mesh. This selected reference mesh is referred to as a representative reference mesh. In other words, the belonging reference mesh number in the first name record of the feature belonging across the plurality of reference meshes is the mesh number of the representative reference mesh that is one of the plurality of reference meshes.

  As the representative reference mesh, for example, the reference mesh at the leftmost end and the lowest end among the reference meshes including the feature is set as the belonging reference mesh. As a result, duplicate name records are not stored for the same feature.

  FIG. 7 shows an example in which a feature straddles a plurality of meshes. In FIG. 7, the feature F10 straddles the reference mesh with the reference mesh numbers 0 and 1, and the belonging reference mesh is the reference mesh with the reference mesh number 0. Hereinafter, the reference mesh whose reference mesh number is n is simply referred to as reference mesh n. The feature F11 extends over the reference meshes 2, 3, 6, and 7, and the belonging reference mesh is the reference mesh 2.

  FIG. 8 is obtained by adding the first name records of the features F10 and F11 to the first name list of FIG. However, the division display maximum hierarchy number of the feature F10 is set to 0, and the division display maximum hierarchy number of the feature F11 is set to 1. The reference mesh number (affiliation reference mesh number) of the representative reference mesh of the feature F10 is set to 0, and the first name record # 6A is stored for the reference mesh 0 including the feature F10. On the other hand, the first name record is not stored for the reference mesh 1 including the feature F10. Further, the reference mesh number (affiliation reference mesh number) of the representative reference mesh of the feature F11 is set to 2, and the first name record # 5A is stored for the reference mesh 2 including the feature F11. On the other hand, the first name record is not stored for the reference meshes 3, 6 and 7 including the feature F11.

  Thus, when a feature belongs across a plurality of meshes, that is, when a feature has a plurality of belonging reference meshes, one representative reference mesh is determined from the belonging reference meshes, Since the first name record is provided, the first name record is not stored redundantly.

<A-4. First name reference list>
Next, the first name reference list constituting the feature name information will be described. The first name reference list is provided in order for the control unit 4 to obtain a necessary first name record from the first name list more quickly, and is not an essential configuration for the navigation device 10.

  FIG. 9 shows a data configuration example of the first name reference list. The first name reference list is a list of first name reference records provided corresponding to the meshes of the respective layers.

  The first name reference record includes a reference hierarchy number, a reference mesh number, a reference head feature ID, a reference first name record number, an external representative reference mesh number, and an external representative reference mesh number sequence. The reference hierarchy number represents a hierarchy number to be referred to when displaying the map. The reference mesh number represents the mesh number of the mesh to be referred to when displaying the map among the meshes of the hierarchy indicated by the reference hierarchy number. Hereinafter, the mesh represented by the reference mesh number in the layer represented by the reference layer number is referred to as a reference mesh.

  The first name record (group) having the reference hierarchy number as the divided display maximum hierarchy number and the reference mesh number as the divided display maximum hierarchy belonging mesh number is referred to as a first name record (group) in the reference mesh. The first name records of the first name record group in the reference mesh are continuously arranged in the first name list, and the feature ID of the first name record at the head is used as the reference head feature ID. In the reference head feature ID, instead of the feature ID, the record number of the first name record and the offset of the first name record (number of bytes from the head of the first name list to the first name record) May be represented.

  The reference first name record number represents the number of first name records constituting the first name record group in the reference mesh. The external representative standard mesh spans the reference mesh and the other meshes, and the belonging standard mesh represents the representative standard mesh of features that are not included in the reference mesh standard mesh, and the number of external representative standard meshes represents the number. ing. The external representative reference mesh number sequence is obtained by arranging reference mesh numbers of external representative reference meshes by the number of external representative reference meshes.

  FIG. 10 is a specific example of the first name reference list for referring to the first name list of FIG. 8, and includes first name reference records # 0 to # 319.

  The first name reference record # 0 is a first name reference record used when displaying a map of a mesh having a hierarchy number of 1 and a mesh number of 0. 1 is set to the reference layer number and 0 is set to the reference mesh number. The first name record group in the reference mesh (the first name record group in which the divided display maximum hierarchy number is 1 and the divided display maximum hierarchy affiliation mesh number is 0) is the first name records # 0 to # 5 and # 5A. . Therefore, ID0 which is the ID of the first name record # 0 is set as the reference head feature ID, and 7 is set as the number of reference first name records. Since there are no features included in the reference mesh of the first name reference record # 0 that straddle other meshes, the number of external representative reference meshes is 0, and there is no external representative reference mesh number sequence.

  The first name reference record # 1 is a first name reference record used when displaying a map of a mesh having a hierarchy number of 1 and a mesh number of 1. 1 is set for the reference layer number and 1 is set for the reference mesh number. There is no first name record group in the reference mesh (the first name record group in which the divided display maximum hierarchy number is 1 and the divided display maximum hierarchy affiliation mesh number is 1). Therefore, a null value (for example, 0xFFFFFFFF) is set as the reference head feature ID, and 0 is set as the reference first name record number. The feature F11 included in the reference mesh of the first name reference record # 1 straddles a mesh having a hierarchical number of 1 and a mesh number of 0. As shown in the name record # 5A, the representative reference mesh number (affiliation reference mesh number) of the feature F11 is 2, which is outside the reference mesh corresponding to the reference mesh of the name reference record, so the number of external representative reference meshes is 1 and 2 is set as the external representative reference mesh number string.

  The first name reference record # 64 is a first name reference record used when displaying a map of a mesh having a hierarchy number of 0 and a mesh number of 0. The reference layer number is set to 0 and the reference mesh number is set to 0. The first name record group in the reference mesh (the first name record group in which the division display maximum hierarchy number is 0 and the division display maximum hierarchy affiliation mesh number is 0) is the first name record # 6, # 6A, # 7. is there. Therefore, ID6 which is the feature ID of the first name record # 6 is set as the reference head feature ID, and 3 is set as the reference first name record number. The feature F10 included in the reference mesh of the first name reference record # 64 straddles the mesh with the hierarchical number 0 and the mesh number 1, and the first name record # 6A representing the name of the feature F10 is the first name in the reference mesh. Since it is included in the record group, the number of external representative reference meshes is 0, and there is no external representative reference mesh number sequence.

  The first name reference record # 65 is a first name reference record used when displaying a map of a mesh having a hierarchy number of 0 and a mesh number of 1. The reference layer number is set to 0 and the reference mesh number is set to 1. The first name record group in the reference mesh (the first name record group in which the divided display maximum hierarchy number is 0 and the divided display maximum hierarchy affiliation mesh number is 1) is the first name record # 8. Therefore, ID8 which is the feature ID of the first name record # 8 is set as the reference head feature ID, and 1 is set as the reference first name record number. The feature F10 included in the reference mesh of the first name reference record # 65 straddles the mesh with the hierarchical number 0 and the mesh number 0, and the representative reference mesh number of the feature F10 as shown in the first name record # 6A. Since (affiliation standard mesh number) is 0 and is outside the standard mesh corresponding to the reference mesh, the number of external representative standard meshes is 1, and 0 is set as the external representative standard mesh number string.

  Other first name reference records are set in the same manner as described above.

  The first name reference list can obtain the first feature ID and the reference first name record number of the first name record necessary for map display for an arbitrary mesh in an arbitrary hierarchy. The first name record is obtained continuously. Even when a feature straddles a plurality of meshes, the affiliation reference mesh number of the first name record is known, so that the first name record can be acquired.

<A-5. Second name list>
FIG. 11 is a data configuration example of the second name list included in the feature name information. The second name list is a list in which second name records representing names or symbols used for map display above the division hierarchy are arranged, and the names stored in the first name list are duplicated. Is also stored. For example, when the division hierarchy is 1 in FIG. 4, the names of the features F2, F3, F4, and F7 stored in the second name list are also stored in the first name list.

  The second name record is set for a feature that displays a name, and includes a feature ID, a display hierarchy number, a display hierarchy affiliation mesh number, a name character string, and a symbol code. That is, the map information storage part 3 is also a name information storage part which memorize | stores the 2nd name list which consists of a 2nd name record.

  A display hierarchy number represents the hierarchy number which displays the name or symbol of a feature. The display hierarchy affiliation mesh number represents the mesh number of the mesh to which the feature having the name belongs in the hierarchy indicated by the display hierarchy number. Since the feature ID, the name character string, and the symbol code are the same as those in the first name record, description thereof is omitted here.

  The second name record is provided corresponding to the name or symbol used for the map display of each mesh in each mesh unit of each layer higher than the divided layer. In the second name list, the second name records are sorted and arranged in descending order of the display hierarchy number, and the second name records having the same display hierarchy number are sorted and arranged in ascending order of the display hierarchy belonging mesh number. Therefore, when displaying a map for an arbitrary mesh above the divided hierarchy or an arbitrary adjacent mesh group, the necessary second name records exist continuously on the second name list, and these are acquired together. Name information can be acquired at high speed.

  FIG. 12 shows a specific example of the second name record provided for the map data of FIG. However, the division hierarchy number is 1.

  The second name record # 0 is provided corresponding to the name or symbol of the feature F4 belonging to the mesh 0 in the hierarchy 3 shown in FIG. 4, and the names or symbols of the features F2, F3, F4, F7 of the mesh 0 in the hierarchy 2 are provided. The second name record # 1 to the second name record # 4 are provided corresponding to the above, and these second name records are sorted according to the above rules.

  Here, in order to make the explanation easy to understand, the number of the second name records is only five, but actually, a larger number of second name records are provided. As the number of second name records increases, the reduction of data and the improvement of access efficiency, which are the effects of the present invention, become more remarkable.

<A-6. Second name reference list>
Next, the second name reference list constituting the feature name information will be described. The second name reference list is provided in order for the control unit 4 to obtain a necessary second name record from the second name list more quickly, and is not an essential configuration for the navigation device 10.

  FIG. 13 shows a data configuration example of the second name reference list. The second name reference list is a list in which second name reference records provided corresponding to the meshes of the layers above the division layer are arranged.

  The second name reference record includes a reference hierarchy number, a reference mesh number, a reference head feature ID, and a reference second name record number. The reference hierarchy number represents a hierarchy number to be referred to when displaying the map. The reference mesh number represents the mesh number of the mesh to be referred to when displaying the map among the meshes of the hierarchy indicated by the reference hierarchy number.

  The second name record (group) having the reference hierarchy number as the display hierarchy number and the reference mesh number as the display hierarchy affiliation mesh number is referred to as a second name record (group) in the reference mesh. Each 2nd name record of the 2nd name record group in a reference mesh is located in a line in the 2nd name list, and makes feature ID of the 2nd name record in the head the reference top feature ID. In the reference head feature ID, instead of the feature ID, the record number of the second name record and the offset of the second name record (number of bytes from the head of the second name list to the second name record) May be represented.

  The reference second name record number represents the number of second name records constituting the second name record group in the reference mesh.

  FIG. 14 shows a specific example of the second name reference list for referring to the second name list of FIG. The second name reference list is composed of second name reference records # 0 to # 19.

  The second name reference record # 0 is a second name reference record used when displaying a map of a mesh having a hierarchy number of 3 and a mesh number of 0. 3 is set for the reference layer number and 0 is set for the reference mesh number. The second name record group in the reference mesh (the second name record group in which the display hierarchy number is 3 and the display hierarchy affiliation mesh number is 0) is only the second name record # 0. Therefore, ID3 which is the feature ID of the second name record # 0 is set as the reference head feature ID, and 1 is set as the reference second name record number.

  The second name reference record # 4 is a second name reference record used when displaying a map of a mesh having a hierarchy number of 2 and a mesh number of 0. 2 is set for the reference layer number and 0 is set for the reference mesh number. The second name record group in the reference mesh (the second name record group in which the display hierarchy number is 2 and the display hierarchy affiliation mesh number is 0) is the second name records # 1 to # 4. Therefore, ID1 that is the feature ID of the second name record # 1 is set as the reference head feature ID, and 4 is set as the reference second name record number.

  In this manner, by providing the first name list and the second name list, when performing map display below the division hierarchy, necessary name information can be acquired only from the first name list. In the first name list, the first name records are sorted by the division display maximum hierarchy number obtained by applying the cap of the division hierarchy to the maximum display hierarchy of the feature. If the name records are simply sorted by the maximum display hierarchy number, it is necessary to refer to the mesh above the reference mesh to obtain the necessary name records when displaying the lower layer map. By sorting by the maximum display hierarchy number, it is only necessary to refer to the mesh of the division hierarchy, so that the number of times of obtaining discontinuously arranged name records can be reduced, and the names can be obtained at higher speed.

  For example, when the division hierarchy number is set to 3 in the map data shown in FIG. 4, that is, when the second name list is not provided, when displaying the mesh 0 of the hierarchy 0, the name information of the feature F3 is the maximum division display. On the other hand, the name information of the feature F4 is stored in the name record B having the division display maximum hierarchy number 3 while being stored in the name record A having the hierarchy number 2. In order to display the names of the features F3 and F4, it is necessary to acquire name records A and B that are not guaranteed to be stored continuously in the name list.

  However, when the division hierarchy number is 1 and the name list is divided into the first name list and the second name list, the names of the features F1, F2, F3, and F4 are displayed when the mesh 0 of the hierarchy 0 is displayed. The information is stored in each first name record whose division display maximum hierarchy number is 1. Since these first name records are continuously stored in the first name list, they can be acquired together at high speed.

<A-7. Operation>
FIG. 15 is a flowchart showing map display processing of the navigation device 10. Below, the operation | movement which displays the map centering on the present position of the mobile body carrying the navigation apparatus 10 with the display scale designated by the user is demonstrated.

  First, the control part 4 acquires the display scale which the user input from the input part 1 (step ST100). Moreover, the control part 4 acquires the positional information on the present location from the position detection part 2, and map information from the map information storage part 3, and calculates the present position of a moving body by a map matching process (step ST110).

  Next, the control unit 4 calculates the mesh (hierarchical number and mesh number) necessary for displaying the map centered on the current position acquired in step ST110, based on the display scale acquired in ST100 (step ST120). . The hierarchy (number) and mesh (number) calculated here are referred to as a display target hierarchy (number) and a display target mesh (number).

  Which hierarchy is used at which display scale is determined in advance. Based on this, a hierarchy to be used at the display scale obtained in ST100 is selected, and a necessary mesh is calculated from the current position, the size of the display screen of the display unit 5, and the size of the mesh of the selected hierarchy.

  For example, the display scale acquired in ST100 corresponds to level 2 in FIG. 2, the size of the display screen corresponds to the size of one mesh in level 2, and the current position calculated in ST110 is level 2. 0, 1, 2, and 3 are calculated as the mesh numbers of the necessary meshes.

  Next, the control unit 4 reads the map data of the display target mesh one by one from the map information storage unit 3 every time it comes to the step (step ST130). In the specific example of ST120, the map data of the meshes 0, 1, 2, and 3 in the hierarchy 2 are sequentially read one by one every time the step is reached.

  When the map data is read in step ST130, the drawing processing unit 41 draws, for example, a background of rivers, seas, railways, etc. in the drawing memory 42 based on the map data, and further draws a road in the drawing memory 42 (step ST140). . The drawing position of each feature in the background is calculated from information representing the feature position and shape stored in the background data in the map data, and the drawing position of each road is stored in the road data in the map data. It is calculated from information representing the position and shape of the road. The drawing color is determined by the type of each background in the background data and the type of each road in the road data.

  Next, it is checked whether or not the display target hierarchy number obtained in step ST120 is equal to or less than the division hierarchy number (step ST150). If it is equal to or less than the division hierarchy number, the process proceeds to step ST160, and otherwise, the process proceeds to ST165. For example, when the division hierarchy number is 1, when the display target hierarchy number is 0 or 1, the process proceeds to step ST160, and when the display target hierarchy number is 2 or 3, the process proceeds to step ST165.

  In step ST160, every time it comes to the step, a required name is acquired from the first name list of the map information storage unit 3 based on the first name reference list of the map information storage unit 3 for each display target mesh. Then, the process proceeds to step ST170. The display target mesh (number) subjected to name acquisition processing in step ST160 is referred to as the current display target mesh (number). In addition, when not using a 1st name reference list, the control part 4 acquires the name of a feature directly from the 1st name list of the map information storage part 3. FIG.

  In step ST165, every time it comes to the step, a required name is acquired from the second name list of the map information storage unit 3 based on the second name reference list of the map information storage unit 3 for each display target mesh. Then, the process proceeds to step ST170.

  The name acquisition process in step ST165 will be described below. First, the second name reference record in which the reference hierarchy number and the reference mesh number of the second name reference list are the display target hierarchy number and the display target mesh number, respectively, is acquired. Then, second name records corresponding to the number of reference second name records are acquired from the second name list from the second name record having the feature ID as the reference head feature ID of the acquired second name reference record.

  More specifically, when the display target hierarchy number is 2 and the display target mesh number is 0, the second name reference having the reference hierarchy number of 2 and the reference mesh number of 0 from the second name reference list shown in FIG. Record # 4 is acquired. Since the reference head feature ID of the second name reference record # 4 is ID1 and the number of reference second name records is 4, the second name record # 1 (ID1), the second name record from the second name list shown in FIG. 2 name record # 2 (ID2), 2nd name record # 3 (ID3), 2nd name record # 4 (ID5) are acquired.

  When the display target hierarchy number is 3 and the display target mesh number is 0, the second name reference record # 0 with the reference hierarchy number 3 and the reference mesh number 0 is acquired from the second name reference list shown in FIG. To do. Since the reference top feature ID of the second name reference record # 0 is ID3 and the number of reference second name records is 1, the second name record # 0 (ID3) is acquired from the second name list shown in FIG. .

  In this way, a name record having name information necessary for the map display of the display target mesh of the display target hierarchy is obtained.

  When the name information is acquired from the first name list or the second name list, the drawing processing unit 41 draws the name information in the vicinity of the corresponding background or road drawn in the drawing memory 42 (step ST170).

  Thereafter, it is checked whether the name drawing process has been completed for all the display target meshes (step ST180). If not completed, the process returns to step ST130, and the name drawing process is continued for the unprocessed display target mesh.

  If the name drawing process has been completed for all the display target meshes, the display control unit 43 displays the contents of the drawing memory 42 on the display unit 5 and the map display is completed (step ST190). Then, it returns to step ST100 and repeats said process.

  FIG. 16 is a flowchart showing the name acquisition process for the current display target mesh in step ST160. Hereinafter, the name acquisition process of step ST160 will be described in detail. First, initial setting of a reference mesh is performed (step ST200). Here, the display target hierarchy number and the current display target mesh number are stored in a hierarchy number variable and a mesh number variable provided in a storage unit (not shown, for example, a memory) of the control unit 4. For example, taking the map data of FIG. 2 as an example, when the display target hierarchy number is 0 and the current display target mesh number is 0, 0 is stored in the hierarchy number variable and 0 is stored in the mesh number variable. When the display target hierarchy number is 0 and the current display target mesh number is 1, 0 is stored in the hierarchy number variable and 1 is stored in the mesh number variable.

  Next, it is determined whether or not the first name reference record of the reference mesh has already been acquired (step ST210). If it has already been acquired, step ST250 is executed, and if it has not been acquired, step ST220 is executed. The map data in FIG. 2 will be described as an example. Assume that the display target hierarchy number is 0 and the current display target mesh numbers are sequentially 0, 1, 2, and 3. When the current display target mesh number is 0, in step ST220 described later, the first name reference record of the mesh having the hierarchy number 1 and the mesh number 0 is read. Thereafter, when the current display target mesh number becomes 1, 2, and 3, the first name reference record of the mesh whose hierarchical number is 1 and whose mesh number is 0 is already stored in the control unit 4 by the above processing. Since it is stored in the storage unit, the process proceeds to step ST250. This determination process prevents duplicate reading of the same name reference record, that is, duplicate reading of the name record.

  If the name reference record of the reference mesh has not yet been acquired (NO in step ST210), the first name reference record in which the values stored in the hierarchy number variable and the mesh number variable become the reference hierarchy number and the reference mesh number, The control part 4 reads from the 1st name reference list of the map information storage part 3, and stores it in a memory | storage part (not shown) (step ST220).

  For example, when the display target hierarchy number is 0 and the current display target mesh number is 0, as described in step ST240, 0 and 1 are sequentially assigned to the hierarchy number variable and the mesh number variable is sequentially assigned to each step ST220. 0 and 0 are already stored respectively. Depending on the values of these variables, the first name reference record of FIG. 10 is stored in the storage unit of the control unit 4 as follows.

  When the hierarchy number variable is 0 and the mesh number variable is 0, the first name reference record # 64 in which the reference hierarchy number is 0 and the reference mesh number is 0 is stored. When the hierarchy number variable is 1 and the mesh number variable is 0, the first name reference record # 0 having the reference hierarchy number 1 and the reference mesh number 0 is stored.

  When the display target hierarchy number is 0 and the current display target mesh number is 1, as described in step ST240, 0 and 1 are sequentially assigned to the hierarchy number variable, 1 is assigned to the mesh number variable, and 0 is already stored. Depending on the values of these variables, the first name reference record of FIG. 10 is stored in the storage unit of the control unit 4 as follows.

  When the hierarchy number variable is 0 and the mesh number variable is 1, the first name reference record # 65 having the reference hierarchy number 0 and the reference mesh number 1 is stored in the storage unit of the control unit 4. The first name reference record # 0 when the hierarchy number variable is 1 and the mesh number variable is 0 has already been acquired in the process when the hierarchy number variable is 0 and the mesh number variable is 0. Therefore, the determination in step ST210 is YES and the process does not move to step ST220. In this way, the same first name reference record is not duplicated.

  Next, the control part 4 acquires a 1st name record from the 1st name list of the map information storage part 3 (step ST230). Here, the first name records corresponding to the number of reference first name records are read from the reference head feature ID of the first name reference record acquired in step ST220, and stored in the storage unit (not shown) of the control unit 4. That is, the control unit 4 acquires the first name record in the reference mesh. Here, since the first name record is continuously read from the first name list, it can be read at high speed.

  In addition, the first name record in which the divided display maximum hierarchy number matches the display target hierarchy number and the affiliation reference mesh number matches the reference mesh number represented by the external reference mesh number string of the first name reference record acquired in ST220. Read and store in the storage unit (not shown) of the control unit 4. That is, the control unit 4 also acquires the name record of the external representative reference mesh.

  Thus, even the first name record belonging to other than the mesh indicated by the mesh number variable can be easily obtained by referring to the external standard mesh number string of the first name reference record. Moreover, since the 1st name record with the same affiliation reference | standard mesh number is located in a line in the 1st name list, these can be read at high speed.

  In addition, in the 1st name record read by step ST230, what a affiliation reference | standard mesh is not contained in a display object mesh is not used for a map display, Therefore It is not necessary to store in the memory | storage part of the control part 4. FIG. Thereby, the capacity | capacitance of a memory | storage part can be reduced.

  A specific example of the name record acquisition process in step ST230 is shown below. When the hierarchy number variable is 0, the mesh number variable is 0, and when the first name reference record # 64 is acquired in step ST220, the reference top feature ID is ID6 and the number of reference first name records is 3. The first name record # 6 (ID6), the first name record # 6A (ID6A), and the first name record # 7 (ID7) in FIG. 8 are stored in the storage unit of the control unit 4. Thereafter, in step ST240, the hierarchy number variable is set to 1 and the hierarchy number variable is 1 and the mesh number variable is 0. Therefore, in the second step ST220, the first name reference record # 0 is acquired. Since the first head reference ID of the first name reference record # 0 is ID0 and the number of reference first name records is 7, the first name records # 0 (ID0) to # 5 (ID5) and first of FIG. Name record # 5A (ID5A) is stored in the storage unit of control unit 4.

  Through the above processing, all of the first name records representing the names necessary for map display where the display target hierarchy is 0 and the current display target mesh is 0 are acquired from the first name list. That is, the control unit 4 acquires, from the name list, a first name record having a divided display maximum hierarchy number equal to or higher than the hierarchy of the target mesh (display target mesh) to be displayed on the map and the belonging reference mesh number corresponding to the display target mesh. did.

  When the hierarchy number variable is 0, the mesh number variable is 1, and when the first name reference record # 65 is acquired in step ST220, the reference head feature ID is ID8 and the number of first reference name records is 1. The first name record # 7 (ID7) in FIG. 8 is stored in the storage unit of the control unit 4. Also, since the number of external reference meshes in the first name reference record # 65 is 1 and the external reference mesh number string is 0, the first name record in which the division display maximum hierarchy number is 0 and the belonging reference mesh number is 0 Is stored in the storage unit of the reading control unit 4. However, since the first name record # 7 (ID7) is already stored in the process when the hierarchy number variable is 0 and the mesh number variable is 0, it is not stored here.

  If a name record is acquired by step ST230, the control part 4 will update a reference mesh so that the mesh corresponding to one upper layer may be represented. Specifically, one layer number variable is added, and the mesh number of the mesh corresponding to the current reference mesh is stored in the mesh number variable in the layer represented by the layer number variable after the change (step ST240).

  The operation of step ST240 will be described using the map data shown in FIG. 2 as an example. When the expression target hierarchy is 0, the current display target mesh number is 0, and the current hierarchy number variable is 0, 1 that is the hierarchy number higher by 1 hierarchy is stored in the hierarchy number variable. After that, among the meshes with the layer number 1 stored in the layer number variable, the mesh number 0 corresponding to the mesh with the display target layer number 0 and the current display target mesh number 0 is used as the mesh number variable. Store.

  Similarly, when the representation target hierarchy is 0 and the current display target mesh number is 1, 1 is stored in the hierarchy number variable and 0 is stored in the mesh number variable in this step.

  After updating the reference mesh in step ST240, it is determined whether name records have been acquired for all upper layer meshes corresponding to the display target mesh (step ST250). As a result of adding the layer number variable in step ST240, if the division layer number is exceeded, it is determined that the name record acquisition processing for the display target mesh and all its upper layer meshes is completed, and the processing ends. Otherwise, the process returns to ST210.

  For example, if the division hierarchy number is 1, when the hierarchy number variable exceeds 1, YES is determined in step ST250, and the process of step ST150 is terminated.

  FIG. 17 is a flowchart showing the name drawing process of the drawing processing unit 41 in step ST160. Hereinafter, the name drawing process of step ST160 will be described in detail. In the name drawing process, the road name and the background name are drawn in the same manner as shown in the flowchart of FIG. In the following description, when the feature is a road, the feature data means road data, and the feature record means a road record. When the feature is the background, the feature data means background data, and the feature record means a background record.

  In the name drawing process, first, the control unit 4 takes out a feature record (to be described later) from the feature data acquired in step ST130 of FIG. 15, and obtains a feature ID for identifying the feature (step ST300).

  Next, the first name record or the second name record (in the following description, simply abbreviated as the name record) stored in the storage unit (not shown) of the control unit 4 in step ST150 or step ST155 of FIG. Then, a name record having the feature ID acquired in step ST300 is acquired (step ST310).

  In addition, you may provide the information which shows the necessity of a name or a symbol display in a feature record. For features that do not require a name or symbol display, the process moves to step ST330 without searching for a name record.

  Next, name drawing is performed (step ST320). Here, the name character string of the name record obtained in step ST310 is obtained, and the drawing processing unit 41 draws the name character string in the drawing memory 42. Specifically, information representing the position and shape of the feature is obtained from the feature record obtained in step ST300, the drawing position of the name character string is calculated from the position and shape of the feature, and the name is calculated at the calculated position. Draw a string. As an example, the position of the center of gravity of the shape of the feature or the position along the shape of the feature is calculated as the drawing position.

  When the feature is the background and the background type is a point, the symbol code is obtained from the name record obtained in ST310, and the symbol drawing position is obtained from the information indicating the background position of the feature (background) record obtained in ST300. Draw a symbol image at that position. The name character string may be drawn together with the symbol image.

  The drawing position may be stored in advance in the feature record or name record, and the name character string or symbol may be drawn at the drawing position. As the drawing position, information representing the representative position of the feature, the position of the center of gravity, the drawing position of each character, and the like may be stored. As a result, the calculation of the drawing position is not necessary, and the map can be displayed at a higher speed. In the case where the drawing position information is stored in the name record, the position of the searched feature can be easily displayed when the feature is searched using the name list as search information.

  Further, the feature and the name information drawn in the drawing memory 42 in this way are displayed on the display unit 5 by the display control unit 43 under the instruction of the display unit 5 in a subsequent process (step ST180 in FIG. 11). In other words, the display control unit 43 of the control unit 4 operates as a map display instruction unit that instructs to display name information together with features.

  Next, it is determined whether or not the name drawing has been completed for all the features for which the feature records have been acquired in step ST300 (step ST330). If it has been completed, the process ends. If not, the process returns to step ST300.

  FIG. 18 is an example of a background record of mesh background data having a hierarchy of 0 and a mesh number of 0. The features F0 to F4 and F8 shown in FIG. 4 and the feature F10 shown in FIG. 7 are used as background features. An example of the case is shown. The background record is composed of a feature ID, a background type, and a position / shape of the feature.

  As described above, in step ST160 in FIG. 15, when the display target hierarchy is 0 and the current display target mesh number is 0, the first name record # 0 (ID0) and the first name record # 1 (ID1) in FIG. ), First name record # 2 (ID2), first name record # 3 (ID3), first name record # 4 (ID4), first name record # 5 (ID5), first name record # 5A (ID5A) ), First name record # 6 (ID6), first name record # 6A (ID6A), and first name record # 7 (ID7) are stored in the storage unit of the control unit 4. Thus, the name record is referred to by the feature ID of each background record in FIG. 18, and the name information of the features F0 to F4 and F8 shown in FIG. 4 and the feature F10 shown in FIG. 7 is drawn.

  In the above description, the feature ID is provided in the background record. However, the data representing the feature ID is not provided in the background record, and is represented by a hierarchy number, a mesh number, and a number in the order of arrangement of the background records. Also good. The same applies to road records.

  Various attributes of features such as address, telephone number, postal code, accessible time, etc. are added to the first and second name records according to the type of the feature, and the name list is used as search information. Also good.

<A-8. Effect>
The navigation device 10 that implements the map data storage device according to the present invention is hierarchized for each scale, and is divided into meshes having a size determined for each layer, and the mesh is identified by a mesh number for each layer. A map data storage unit (map information storage unit 3) for storing map data representing features for each mesh and a name list including name records set for the features for displaying names are stored. In the map data, each feature belongs to each mesh from the lowest layer to the hierarchy defined for each feature, and the name list is predetermined. A first name list representing name information including at least one of the names or symbols of features below the division hierarchy, and a second name representing name information of features above the division hierarchy The name information represented by the first name list does not overlap with each other, the name information represented by the second name list overlaps with the name information represented by the first name list, and the first name record included in the first name list Is the display maximum hierarchy number indicating the maximum display hierarchy, which is the maximum hierarchy in which the feature name information is displayed, and the split hierarchy if the display maximum hierarchy number exceeds the split hierarchy number indicating the split hierarchy It is the data linked to the division display maximum hierarchy number as a number and the affiliation reference mesh number indicating the affiliation reference mesh that is the reference mesh to which the feature belongs, and the first name record is the maximum division display of the first name list. It is the list sorted based on the division display maximum hierarchy affiliation mesh number which is the affiliation mesh number in the hierarchy number, the affiliation reference mesh number, and the division display maximum hierarchy. When drawing the mesh below the division hierarchy, the first name record is acquired from the first name list. However, the first name records for the features belonging to the same or nearby mesh are continuously displayed in the first name list. Since it is arranged, it is possible to obtain efficiently. Furthermore, since the first name records are sorted by the division display maximum hierarchy number, when drawing the mesh below the division hierarchy, the necessary first name records can be obtained by referring to the mesh from the hierarchy to the division hierarchy. Can be acquired. Therefore, it is possible to reduce the number of times that the name records arranged discontinuously are acquired, and it is possible to acquire the names at a higher speed.

  A navigation device 10 that realizes a map display device according to the present invention includes a map data storage device, a name record acquisition unit (control unit 4) that acquires a name record from the map data storage device, and a map from the map data storage device. A map display instructing unit (control unit 4) for obtaining data and instructing display of the feature based on the data, and instructing to display name information of the name record acquired by the name record acquiring unit together with the feature. The name record acquisition unit (control unit 4) acquires a name record from the first name list when the hierarchy of the target mesh to be displayed on the map is equal to or lower than the division hierarchy, and the name record acquisition unit (control unit 4). The name record acquired from the first name list has the division display maximum hierarchy number higher than the hierarchy of the target mesh and the reference mesh number corresponding to the target mesh. . When drawing the mesh below the division hierarchy, the control unit 4 acquires the first name record from the first name list, but the first name record for the features belonging to the same or nearby mesh is the first name list. Therefore, it is possible to obtain efficiently. Furthermore, since the first name records are sorted by the division display maximum hierarchy number, when drawing the mesh below the division hierarchy, the necessary first name records can be obtained by referring to the mesh from the hierarchy to the division hierarchy. Can be acquired. Therefore, it is possible to reduce the number of times that the name records arranged discontinuously are acquired, and it is possible to acquire the names at a higher speed.

  Moreover, since the first name list is a list sorted by the priority order of the maximum display hierarchy number, the maximum display hierarchy affiliation mesh number, and the affiliation reference mesh number, the first name for features belonging to the same or nearby meshes. Records are continuously arranged in the first name list, and the control unit 4 can efficiently acquire the first name record when performing map display.

  The second name record that is a name record of the second name list is data in which name information is associated with a display hierarchy number of a feature and a display hierarchy belonging mesh number that is a belonging mesh number in the display hierarchy of the feature. In addition, since the second name list is a list in which the second name records are sorted based on the display hierarchy number and the display hierarchy affiliation mesh number, the control unit 4 can acquire the second name record at high speed.

  In addition, the name information storage unit (map information storage unit 3) has a reference hierarchy that is an arbitrary hierarchy as a divided display maximum hierarchy, and a reference mesh that is an arbitrary mesh in the reference hierarchy as a display maximum hierarchy belonging mesh. A first name reference list indicating the storage location in the first name list of the first name record in the reference mesh that is a record is further stored. Therefore, since the storage part in the 1st name list of the 1st name record required for map display is known by referring to the 1st name reference list, control part 4 can acquire the 1st name record more quickly.

  In addition, one first name record is provided for a feature belonging across a plurality of reference meshes, and the belonging reference mesh number for the feature is one of the plurality of reference meshes. This is the mesh number of the representative reference mesh. Even if the feature straddles a plurality of reference meshes, the first name record is not stored redundantly, so that the data amount of the first name list can be reduced.

  The first name reference list is a representative standard mesh of features straddling the reference mesh and other meshes, and includes information representing an external representative standard mesh that is a representative standard mesh not included in the reference mesh, and includes a name record acquisition unit (Control part 4) acquires the 1st name record in a reference mesh, and the 1st name record of an external representation standard mesh. Therefore, even if there is no representative standard mesh of features straddling a plurality of standard meshes in the first name record in the reference mesh, the first name record can be easily acquired.

  Further, the map data has a feature ID for identifying the feature, the name record is data in which the name information is linked to the feature ID, and the map display instruction unit (display control unit 43) The name information is displayed together with the feature of the corresponding feature ID. Thereby, it is possible to display name information with respect to a corresponding road and background.

  Moreover, since the display position of the name information in the map display instruction section (display control section 43) is determined based on the position and shape of the feature, the name information should be displayed at an appropriate position with respect to the corresponding road and background. Is possible.

  Further, when the first and second name records have position information for displaying the name information, calculation of the display position of the name information is not necessary, so that the map display can be performed at a higher speed. Further, when the name list is used as search information, the position of the searched feature can be easily displayed.

  In the present invention, the embodiments can be appropriately modified and omitted within the scope of the invention.

  Although the present invention has been described in detail, the above description is illustrative in all aspects, and the present invention is not limited thereto. It is understood that countless variations that are not illustrated can be envisaged without departing from the scope of the present invention.

  DESCRIPTION OF SYMBOLS 1 Input part, 2 Position detection part, 3 Map information memory | storage part, 4 Control part, 5 Display part, 6 Voice output part, 10 Navigation apparatus, 41 Drawing process part, 42 Drawing memory, 43 Display control part

Claims (9)

Layered at each scale, divided into meshes of a size determined for each layer, the mesh is identified by a mesh number for each layer, the lowest mesh is used as a reference mesh, and each mesh represents a feature A map data storage unit for storing map data;
A name information storage unit that stores a name list composed of name records set for features for displaying names, and
In the map data, each feature belongs to each mesh of each layer from the lowest layer to the layer defined for each feature,
The name list includes a first name list representing name information including at least one of the name or symbol of the feature below a predetermined division hierarchy other than the uppermost layer and other than the lowermost layer, and the upper layer above the division hierarchy A second name list representing the name information of the feature,
Name information represented by the first name list does not overlap with each other, name information represented by the second name list overlaps with name information represented by the first name list,
The first name record included in the first name list includes a display maximum hierarchy number indicating a display maximum hierarchy which is a maximum hierarchy in which the name information of the feature is displayed, and the display maximum hierarchy. When the number exceeds the division hierarchy number indicating the division hierarchy, the division display maximum hierarchy number as the division hierarchy number and the affiliation reference mesh number indicating the affiliation reference mesh that is the reference mesh to which the feature belongs are linked Data,
The first name list includes a divided display maximum hierarchy belonging mesh number that is a belonging mesh number in the divided display maximum hierarchy , wherein the first name record is the divided display maximum hierarchy number, the hierarchy indicated by the divided display maximum hierarchy number, and It is a list sorted by the priority of the affiliation reference mesh number ,
Map data storage device. A map data storage device according to claim 1;
A name record acquisition unit for acquiring the name record from the map data storage device;
A map for acquiring the map data from the map data storage device and instructing display of features based on the map data, and for instructing display of the name information of the name record acquired by the name record acquisition unit together with the features A display instruction section;
With
The name record acquisition unit acquires the name record from the first name list when the hierarchy of the target mesh for performing map display is equal to or lower than the division hierarchy,
The name record acquired by the name record acquisition unit from the first name list includes the division display maximum hierarchy number equal to or higher than the hierarchy of the target mesh, and the belonging reference mesh number corresponding to the target mesh.
Map display device. The second name record, which is a name record of the second name list, links the name information to the display hierarchy number of the feature and the display hierarchy affiliation mesh number that is the affiliation mesh number in the display hierarchy of the feature. Data
  The second name list is a list in which the second name records are sorted based on the display hierarchy number and the display hierarchy affiliation mesh number.
The map display device according to claim 2. The name information storage unit
  The first name in the reference mesh that is the first name record of the feature for which each layer in each layer below the divided layer becomes the divided display maximum layer and the mesh becomes the divided display maximum layer belonging mesh. Further storing a first name reference list indicating a storage location of the record in the first name list;
The map display device according to claim 2. One first name record is provided for a feature belonging across a plurality of reference meshes,
  The affiliation reference mesh number for the feature is a mesh number of a representative reference mesh that is one of the plurality of reference meshes.
The map display device according to claim 4. The first name reference list is:
  A representative standard mesh of features straddling the reference mesh and other meshes, including information representing an external representative standard mesh that is the representative standard mesh not included in the reference mesh,
  The name record acquisition unit acquires the first name record in the reference mesh and the first name record of the external representative reference mesh.
The map display device according to claim 5. The map data has a feature ID for identifying the feature,
  The name record is data in which the name information is associated with a feature ID,
  The map display instruction unit instructs to display the name information together with the feature of the corresponding feature ID.
The map display device according to claim 2. The display position of the name information indicated by the map display instruction unit is determined based on the position and shape of the feature.
The map display device according to claim 2. The name record has position information for displaying the name information.
The map display device according to claim 2.

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