Storage medium for map information for navigation system and system for offering map information for navigation system

• US 5,515,284 A
• Filed: 04/19/1995
• Issued: 05/07/1996
• Est. Priority Date: 09/25/1991
• Status: Expired due to Term

• Current Assignee: TomTom International BV (TomTom NV)
• Original Assignee: Zexel Corporation (Robert Bosch GmbH)
• Inventors: Abe, Tatsuhiko
• Primary Examiner(s): PARK, COLLIN
• Application Number:
  US08/425,353
• Time in Patent Office: 384 Days
• Field of Search: 364/443, 364/444, 364/449, 340/990, 340/995, 73/178 R
• US Class Current: 701/202
• CPC Class Codes: G01C 21/3881 Tile-based structures

Abstract

A storage medium for map information for a navigation system includes an IC memory chip or an IC memory card of a small memory capacity. This storage medium stores detailed map information of a limited region including part of a highway network and information of the highway network covering a predetermined area which includes the limited region and is wider than the limited region. A system for offering map information for a navigation system includes two storage media. One storage medium is the same as the above-mentioned storage medium and the other storage medium has a small memory capacity. The other storage medium stores detailed map information of a limited region different from the limited region whose information is stored in the one storage medium.

Claims

1. A navigation system, comprising:

(a) a first memory for storing first map information, said first map information including (i) information of a highway network covering the whole of a predetermined area and (ii) map information of only a first limited region more detailed than the information of the highway network, said detailed map information of said first limited region including an ordinary road network, and said predetermined area including said first limited region and being wider than said first limited region;

(b) a second memory for storing second map information, said second memory being separate from said first memory, said second map information including (i) information of at least a part of said highway network in a second limited region and (ii) map information of only a second limited region more detailed than the information of the highway network of only said second limited, said detailed map information of said second limited region including an ordinary road network, and said predetermined area including said second limited region and being wider than said second limited region;

(c) one of said first and second memory being in a form of an IC memory chip mounted on a circuit board and the other being in a form of an IC memory card;

(d) read means for reading said first and second map information from said first and second memory, said read means having a slot portion for electrical connection with said IC memory card; and

(e) a microcomputer for computing, based on said first and second map information read by said read means an optimum route from a starting point to a destination, said starting point being inside one of said first and second limited regions, and said destination being inside the other of said first and second limited regions.

2. A system according to claim 1, in which said second memory further contains the information of said highway network covering said predetermined area.

3. A system according to claim 1, further comprising a map information-offering IC memory card, and write means for writing the map information of said map information-offering IC memory card, connected to said slot portion, onto said IC memory chip.

4. A system according to claim 1, further comprising a map information-writing IC memory card, and write means for writing the map information of said IC memory chip onto said map information-writing IC memory card connected to said slot portion.

5. A navigation system, comprising:

(a) a first memory for storing first map information, said first map information including (i) information of a highway network covering the whole of a predetermined area and (ii) map information of only a first limited region more detailed than the information of the highway network, said detailed map information of said first limited region including an ordinary road network, and said predetermined area including said first limited region and being wider than said first limited region;

(b) a second memory for storing second map information, said second memory being separate from said first memory, said second map information including (i) information of at least a part of said highway network in a second limited region and (ii) map information of only a second limited region more detailed than the information of the highway network, said detailed map information of said second limited region including an ordinary road network, and said predetermined area including said second limited region and being wider than said second limited region;

(c) said first and second memory being in the form of IC memory chips mounted on a circuit board;

(d) read means for reading said first and second map information from said first and second memory; and

(e) a microcomputer for computing an optimum, based on said first and second map information read by said read means, an optimum route from a starting point to a destination, said starting point being inside one of said first and second limited regions, and said destination being inside the other of said first and second limited regions.

6. A system according to claim 5, further comprising a map information-offering IC memory card, slot means for electrical connection with said IC memory card, and write means for writing the map information of said IC memory card, connected to said slot means, onto at least one of said two IC memory chips.

7. A system according to claim 5 in which said second memory further contains the information of said highway network covering said predetermined area.

8. A system for offering map information for a navigation system, comprising:

(a) a first memory for storing first map information, said first map information including (i) information of a highway network covering the whole of a predetermined area and (ii) map information of only a first limited region more detailed than the information of the highway network, said detailed map information of said first limited region including an ordinary road network, and said predetermined area including said first limited region and being wider than said first limited region;

(b) a second memory for storing second map information, said second memory being separate from said first memory, said second map information including (i) information of at least a part of said highway network in a second limited region and (ii) map information of only a second limited region more detailed than the information of the highway network, said detailed map information of said second limited region including an ordinary road network, and said predetermined area including said second limited region and being wider than said second limited region;

(c) said first and second memory being in the form of IC memory cards;

(d) read means for reading said first and second map information from said first and second memory, said read means having two slot portions for electrical connection with said first and second memory, respectively; and

(e) a microcomputer for computing, based on said first and second map information read by said read means, an optimum route from a starting point to a destination, said starting point being inside one of said first and second limited regions, and said destination being inside the other of said first and second limited regions.

9. A system according to claim 8 in which said second memory further contains the information of said highway network covering said predetermined area.