Map display apparatus storing data of physically adjacent map sections in physically adjacent storage locations

• US 4,937,572 A
• Filed: 08/09/1988
• Issued: 06/26/1990
• Est. Priority Date: 04/27/1985
• Status: Expired due to Term

• Current Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Original Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Inventors: Yamada, Takeshi, Fujii, Norihisa, Fujii, Tomoyasu, Ito, Kenzo
• Primary Examiner(s): Orsino, Joseph A.
• Assistant Examiner(s): SWARTHOUT, BRENT
• Application Number:
  US07/231,642
• Time in Patent Office: 686 Days
• Field of Search: 340/988, 340/990, 340/995, 364/424, 364/444, 364/449, 364/460, 73/178 R, 353/12, 358/108
• US Class Current: 340/995.18
• CPC Class Codes: G01C 21/3878 Hierarchical structures, e.g. layering
• CPC Class Codes: G01C 21/3881 Tile-based structures

Abstract

A map display apparatus displays a map of a desired district in accordance with stored map data. The apparatus includes a recording medium storing map data of a map to be displayed in a manner that the whole area of the map is divided into a plurality of districts and the map data are successively stored starting from the nearest district, a display district selecting device for selecting the desired map district to be displayed, a control unit for reading the map data of the selected district from the recording medium and generating a control signal for displaying the thus read map data, and a display responsive to the control signal to display the map of the selected district. The map data of each district includes duplicate map data of the boundary parts of the adjoining districts. Map data of adjacent districts are stored in adjacent memory locations. Thus, the map data of the desired district can be displayed quickly.

Claims

1. A map display apparatus for displaying a map in accordance with stored data comprising:

map data recording means for storing map data indicative of said map to be displayed, a whole area of said map being divided into a plurality of districts, said map data recording means storing map data representing each of said districts in a successive, one-dimensional sequence at map data storage locations, wherein each of said plurality of districts is further subdivided into a plurality of sections, said map data recording means recording said plurality of sections such that map data representing each of said sections are successively stored in sequence and map data of physically adjacent districts are stored in physically adjacent memory locations even where adjacent sections are from different districts, and said map data recording means also storing an adjoining portion map data which represents a portion of at least one adjoining district to said each district said adjoining portion map data being indicative of same information as a portion of map data representing said adjoining district which is stored in a map data storage location for said adjoining district and being different from said map data storage location of said each district;

indicating means for indicating a predetermined area of said map to be displayed;

map display control means for;

(1) determining if said predetermined area indicated by said indicating means is entirely included within one of said plurality of districts, and one dimensionally reading out map data from a plurality of said sections of said one of said plurality of districts from said map data recording means if so to retrieve said data indicating said plurality of sections as display data for said one district, and

(2) determining when said predetermined area indicated by said indicating means extends from one of said districts into an adjacent district thereto, and one dimensionally reading out map data for (a) said one of said districts and (b) said adjoining portion map data for a portion of said adjacent district from a map data storage location for said adjoining district to said one district to retrieve said map data for a first portion of said one district and for a second portion of said adjacent district as display data; and

display means responsive to said display data from said map display control means for combining said map data indicating said sections included in said display data to display a map of said indicated area based thereon.

2. A map display apparatus for displaying a map in accordance with stored data comprising:

map data recording means for storing map data indicative of said map to be displayed, a whole area of said map being divided into a plurality of districts, said map data recording means storing map data representing each of said districts in a successive, one-dimensional sequence at map data storage locations, wherein each of said plurality of districts is divided into a plurality of sections, each of said plurality of sections being further subdivided into a plurality of subsections, and wherein said map data recording medium records map data representing each of said subsections successively in sequence such that map data from adjoining subsections are recorded in adjoining memory locations even where adjacent subsections belong to different sections, and said map data recording means also storing an adjoining portion map data which represents a portion of at least one adjoining district to said each district said adjoining portion map data being indicative of same information as a portion of map data representing said adjoining district which is stored in a map data storage location for said adjoining district and being different from said map data storage location of said each district;

indicating means for indicating a predetermined area of said map to be displayed;

map display control means for;

(1) determining if said predetermined area indicated by said indicating means is entirely included within one of said plurality of districts, and one dimensionally reading out map data from a plurality of said sections of said one of said plurality of districts from said map data recording means if so to retrieve said data indicating said plurality of sections as display data for said one district, and

(2) determining when said predetermined area indicated by said indicating means extends from one of said districts into an adjacent district thereto, and one dimensionally reading out map data for (a) said one of said districts and (b) said adjoining portion map data for a portion of said adjacent district from a map data storage location for said adjoining district to said one district to retrieve said map data for a first portion of said one district and for a second portion of said adjacent district as display data; and

display means responsive to said display data from said map display control means for combining said map data indicating said sections included in said display data to display a map of said indicated area based thereon.

3. A method for displaying a map in accordance with stored data, comprising the steps of:

successively storing map data in a one dimensional sequence representing each of a plurality of districts and each of a plurality of positions within said each district by defining a map data storage location for each said portion in which to store map data representing said each portion a map data for each district including a portion of at least one physically adjoining district to said each district

said map data in said map data storage location representing said portion of each said physically adjoining district being indicative of same information as map data representing said portion of each physically adjoining district which is stored in a map data storage location for said each physically adjoining district which is different from said map data storage location of said each of said districts;

wherein the step of recording map data includes the step of dividing each of said plurality of districts into a plurality of sections such that map data representing each of said sections are successively stored in sequence starting from adjoining sections adjacent to one of said sections and map data of physically adjacent districts are stored in physically adjacent memory locations even where adjacent sections belong to different district;

indicating a predetermined area in said map to be displayed;

first determining when said predetermined area indicated by said indicating step is included in one of said plurality of districts

one-dimensionally reading out map data of said one of said plurality of districts to display said indicated area based on read-out data, when said first determining step is positive;

second determining when said predetermined area indicated by said indicating means extends from one of said districts to an adjacent district;

one-dimensionally reading out the map data of at least one portion of said one of said districts and map data of a portion of said adjacent district to display said predetermined area by combining both said map data of said at least one portion of said one of districts and said map data of said portion of said adjacent district when said second determining step is positive; and

displaying a map responsive to a combination of said read out map data.

4. A method for displaying a map in accordance with stored data, comprising the steps of:

successively storing map data in a one dimensional sequence representing each of a plurality of districts and each of a plurality of positions within said each district by defining a map data storage location for each said portion in which to store map data representing said each portion a map data for each district including a portion of at least one physically adjoining district to said each district

said map data in said map data storage location representing said portion of each said physically adjoining district being indicative of same information as map data representing said portion of each physically adjoining district which is stored in a map data storage location for said each physically adjoining district which is different from said map data storage location of said each of said districts;

wherein said step of recording map data includes the step of dividing each of said plurality of districts into a plurality of sections, and further dividing each of said plurality of sections into a plurality of subsections, map data representing each of said subsections being successively stored in sequence starting from adjoining subsections adjacent to one of said subsections and map data of physically adjacent districts are stored in physically adjacent memory locations even were adjacent subsections belong to different sections

indicating a predetermined area in said map to be displayed;

first determining when said predetermined area indicated by said indicating step is included in one of said plurality of districts

one-dimensionally reading out map data or said one of said plurality of districts to display said indicated area based on read-out data, when said first determining step is positive;

second determining when said predetermined area indicated by said indicating means extends from one of said districts to an adjacent district;

one-dimensionally reading out the map data of at least one portion of said one of said districts and map data of a portion of said adjacent district to display said predetermined area by combining both said map data of said at least one portion of said one of districts and said map data of said portion of said adjacent district when said second determining step is positive; and

displaying a map responsive to a combination of said read out map data.