Map display unit

• US 6,307,485 B1
• Filed: 09/24/1999
• Issued: 10/23/2001
• Est. Priority Date: 09/25/1998
• Status: Expired due to Fees

• Current Assignee: Transtechnology Ltd.
• Original Assignee: Jatco Limited (Nissan Motor Co., Ltd.)
• Inventors: Hasegawa, Shinichi
• Primary Examiner(s): Lee, Benjamin C.
• Application Number:
  US09/404,761
• Time in Patent Office: 760 Days
• Field of Search: 340/995, 340/988, 340/997, 701/212, 701/211, 701/208, 701/213
• US Class Current: 340/995.15
• CPC Class Codes: G01C 21/20 Instruments for performing navigational calculations G01C21/24, G01C21/26 take precedence
• CPC Class Codes: G01S 19/13 Receivers

Abstract

A map display unit is provided with a set uni that sets a rule for extracting map information from a storage device. The set unit sets a first rule for most preferentially extracting map information on the largest scale and a second rule for most preferentially extracting map information on a specified scale. For this reason, if the first rule is set, a map on the largest scale having detailed information can be displayed, even if a map were switched. Therefore, the accuracy of route guidance can be enhanced by displaying a map suitable when passing through complicated geographical features or city. On the other hand, if the second rule is set, an arbitrary scale can be specified. For example, if a map on the smallest scale is specified, it can overlook a wide range of area and therefore the entire planed route can easily be grasped.

Claims

1. A map display unit comprising:

position detection means for detecting its present position;

storage means for storing map information on various scales including a predetermined map on a predetermined scale which must overcome a barrier in order to move out of said predetermined map;

extraction means for extracting map information including said present position detected by said position detection means from said storage means in accordance with a predetermined extracting rule;

display control means for synthesizing a mark representing said present position and the extracted map information and then displaying them on display means; and

set means for setting said extracting rule;

wherein said set means sets a first rule for most preferentially extracting map information on the largest scale and a second rule for most preferentially extracting map information on a specified scale.

2. The map display unit as set forth in claim 1, wherein said set means further sets a third rule for having a user select displayed scales of corresponding maps and also extracting map information on the selected scale.

3. The map display unit as set forth in claim 1, wherein said set means sets a fourth rule for extracting a map on the second-largest scale in corresponding maps when a map on the largest scale is not present in the corresponding maps in setting said first rule, and also displays a message indicating that the scale of the map has been changed.

4. The map display unit as set forth in claim 1, wherein said set means sets a fifth rule for having a user select one of displayed scales of corresponding maps when a map on a specified scale is not present in the corresponding maps in setting said second or third rule and also for extracting a map on the selected scale, and said set means also sets a sixth rule for displaying only the present-position mark without extracting the corresponding maps when the scales of the corresponding maps are not selected.

5. The map display unit as set forth in claim 4, wherein said set means displays information indicating a relative relation between a mark position on a map being displayed just before and the newest mark position in setting said sixth rule.

6. A map display unit comprising:

position detection means for detecting its present position;

storage means for storing map information on various scales;

extraction means for extracting map information including said present position detected by said position detection means from said storage means in accordance with a predetermined extracting rule;

display control means for synthesizing a mark representing said present position and the extracted map information and then displaying them on display means; and

set means for setting said extracting rule;

wherein said set means sets a first rule for most preferentially extracting map information on the largest scale and a second rule for most preferentially extracting map information on a specified scale.

7. The map display unit as set forth in claim 6, wherein said set means further sets a third rule for having a user select displayed scales of corresponding maps and also extracting map information on the selected scale.

8. The map display unit as set forth in claim 7, wherein said set means sets a fifth rule for having a user select one of displayed scales of corresponding maps when a map on a specified scale is not present in the corresponding maps in setting said second or third rule and also for extracting a map on the selected scale, and said set means also sets a sixth rule for displaying only the present-position mark without extracting the corresponding maps when the scales of the corresponding maps are not selected.

9. The map display unit as set forth in claim 6, wherein said set means sets a fourth rule for extracting a map on the second-largest scale in corresponding maps when a map on the largest scale is not present in the corresponding maps in setting said first rule, and also displays a message indicating that the scale of the map has been changed.

10. The map display unit as set forth in claim 6, wherein said set means sets a fifth rule for having a user select one of displayed scales of corresponding maps when a map on a specified scale is not present in the corresponding maps in setting said second or third rule and also for extracting a map on the selected scale, and said set means also sets a sixth rule for displaying only the present-position mark without extracting the corresponding maps when the scales of the corresponding maps are not selected.

11. The map display unit as set forth in claim 10, wherein said set means displays information indicating a relative relation between a mark position on a map being displayed just before and the newest mark position in setting said sixth rule.