Method and apparatus for displaying a night-view map

• US 20050228586A1
• Filed: 03/14/2005
• Published: 10/13/2005
• Est. Priority Date: 03/26/2004
• Status: Active Grant

• Current Assignee: Alpine Electronics Incorporated (Alps Alpine Co., Ltd.)
• Original Assignee: Alpine Electronics Incorporated (Alps Alpine Co., Ltd.)
• Inventors: Yuasa, Mizuki, Kurosawa, Takeshi
• Granted Patent: US 7,761,230 B2
• Time in Patent Office: Days
• US Class Current: 701/208
• CPC Class Codes: G08G 1/0969 having a display in the form of a map
• CPC Class Codes: G09B 29/106 using electronic means

Abstract

A navigation apparatus including a memory for storing building data of buildings; a display; a decimating unit for decimating the building data based on the unit of the bar scale of a map appearing on the display; and a display controller for displaying the buildings on a map on the display based on the building data decimated by the decimating unit.

Claims

1. An electronic device having a navigation function comprising:

memory operable to store building data;

a display;

decimating means for decimating the building data based on the unit of the bar scale of a map appearing on the display; and

display controlling means for displaying the buildings on a map on the display based on the building data decimated by the decimating means.

2. The electronic device according to claim 1, wherein the decimating means processes the building data so as to reduce the number of buildings when the unit of the bar scale exceeds a predetermined threshold value.

3. The electronic device according to claim 1, wherein the decimating means processes the building data so as to reduce the sizes of the buildings when the unit of the bar scale exceeds a predetermined threshold value.

4. The electronic device according to claim 1, wherein the decimating means processes the building data so that a predetermined number of buildings are located at random when the unit of the bar scale exceeds a predetermined threshold value.

5. The electronic device according to claim 1, wherein the decimating means processes the building data so that the number of buildings that are located in each of predetermined areas on the display does not exceed a predetermined number when the unit of the bar scale exceeds a predetermined threshold value.

6. The electronic device according to claim 1, wherein the decimating means processes the building data so that buildings that are located in a selected area on the display are displayed when the unit of the bar scale exceeds a predetermined threshold value.

7. The electronic device according to claim 1, wherein the decimating means processes the building data so that buildings that are located on a selected vertical or horizontal line on the display are displayed when the unit of the bar scale exceeds a predetermined threshold value.

8. The electronic device according to claim 1, wherein the building data includes two-dimensional location data of the buildings, the decimating means selects at least one point from a plane specified by the two-dimensional location data, and the display controlling means displays the at least one selected point.

9. The electronic device according to claim 1, wherein the decimating means consolidates building data of a plurality of buildings adjacent to each other into one building data segment.

10. The electronic device according to claim 9, wherein the decimating means weights the building data segment to determine a display color according to the number of buildings.

11. The electronic device according to claim 1, wherein the display controlling means changes the colors of the buildings depending on whether it is daytime or nighttime.

12. The electronic device according to claim 1, wherein the decimating means has a plurality of threshold values, determines the unit of the bar scale based on the plurality of threshold values, and decimates the building data according to the result of the determination.

13. A vehicle-mounted navigation apparatus comprising:

a data memory operable to store building data;

a display;

a controller operable to decimate building-shape data based on the unit of the bar scale of a map appearing on the display; and

a display controller operable to displaying a map based on the building-shape data decimated by the controller.

14. The vehicle-mounted navigation apparatus of claim 13, further comprising a sensor operable to detect if it is nighttime, wherein the controller receives the detection result from the nighttime sensor to determine whether it is nighttime and the display controller operates in a nighttime mode when the controller determines that it is nighttime.

15. The vehicle-mounted navigation apparatus of claim 14, wherein the nighttime sensor detects an on-off operation of a light switch of a vehicle.

16. The vehicle-mounted navigation apparatus according to claim 13, wherein, in the night-view map, a color of a background image is adjusted to black or a dark color corresponding to the nighttime, roads are displayed in white or a light color, and parts corresponding to the decimated building-shape data emit light.

17. A method for displaying buildings in an electronic device having a navigation function, the method comprising the acts of:

providing a map displayed on a display, the map having a bar scale and the bar scale having a unit size determining the unit size of the bar scale of a map appearing on a display;

decimating building data based on the unit size of the bar scale; and

displaying buildings based on the decimated building data.

18. The method of claim 17, wherein the act of decimating building data reduces the number of buildings when the unit of the bar scale exceeds a predetermined threshold value.

19. The method of claim 17, wherein the act of displaying buildings comprises displaying one or more buildings as light spots in nighttime driving based on the decimated building data.

20. The method of claim 19, wherein the act of displaying buildings further comprises changing the color of each light spot according to a building density based on the decimated building data.