Unit and program for displaying map

• US 20040066316A1
• Filed: 08/08/2003
• Published: 04/08/2004
• Est. Priority Date: 08/09/2002
• Status: Active Grant

• Current Assignee: Aisin AW Company Limited (Aisin Corp.)
• Original Assignee: Aisin AW Company Limited (Aisin Corp.)
• Inventors: Ogawa, Tsuyoshi
• Granted Patent: US 7,199,800 B2
• Time in Patent Office: Days
• US Class Current: 340/995.1
• CPC Class Codes: G01C 21/367 Details, e.g. road map scale, orientation, zooming, illumination, level of detail, scrolling of road map or positioning of current position marker
• CPC Class Codes: G01C 21/3673 Labelling using text of road map data items, e.g. road names, POI names
• CPC Class Codes: G01C 21/3852 Data derived from aerial or satellite images
• CPC Class Codes: G08G 1/0969 having a display in the form of a map

Abstract

The invention provides a map display unit including a first memory for storing map data and a drawing memory for drawing the map data and displaying display-area data and a display. The map display unit includes a unit to read and decompress compressed map data stored in blocks in a data storage medium and to store the decompressed map data in the first memory; a unit to draw the stored map data in the drawing memory; and a unit to determine the display area and to display the display-area data of the drawing area in the drawing memory on the display. When there is no display-area data in the first memory, compressed map data is read and decompressed from the data storage medium by the data decompression unit. The map display unit further includes an environmental change sensor and controllers to vary the color tone of the map data with the environmental change, thereby displaying easily viewable map data.

Claims

1. A map display unit including a first memory for storing map data and a drawing memory for drawing the map data and displaying display-area data of a drawing area in the drawing memory on a display, comprising:

data-decompressing means for reading and decompressing compressed map data stored in a data storage medium and storing the decompressed map data in the first memory;

drawing means for drawing the map data stored in the first memory in the drawing memory; and

display-control means for determining the display area and displaying the data on the display area of the drawing area in the drawing memory on the display, wherein, when there is no display-area data in the first memory, compressed map data including the display area is read out and decompressed from the data storage medium by the data-decompressing means.

2. The map display unit according to claim 1, wherein the compressed map data is raster data divided into blocks and having positional information for each block.

3. The map display unit according to claim 1, wherein, when there is no display-area data in the first memory, the compressed map data including the display area, which is read out from the data storage medium, is compressed map data obtained on the basis of the positional information of the compressed map data and the coordinates of the display area.

8. The map display unit according to claim 2, wherein the raster data is satellite photograph data.

9. The map display unit according to claim 1, wherein the data-decompressing means manages the use history of the map data stored in the first memory, erases the map data in early order, and stores the decompressed map data in the first memory.

4. A map display unit including a first memory for storing map data and a drawing memory for drawing the map data and displaying display-area data of a drawing area in the drawing memory on a display, comprising:

data-decompressing means for reading and decompressing compressed map data stored in a data storage medium and storing the decompressed map data in the first memory;

drawing means for drawing the map data stored in the first memory in the drawing memory; and

display-control means for determining the display area and displaying the display-area data of the drawing area in the drawing memory on the display, wherein, when there is no display-area data in the drawing area of the drawing memory, map data on the display area is read out from the first memory and is drawn in the drawing memory by the drawing means.

5. A map display unit including a first memory for storing map data and a drawing memory for drawing the map data and displaying display-area data of a drawing area in the drawing memory on a display, comprising:

data-reading means for selectively reading compressed map data and uncompressed map data from a data storage medium;

data-decompressing means for decompressing the compressed map data read out by the data-reading means and storing the decompressed map data in the first memory;

drawing means for drawing either of the uncompressed map data read out by the data-reading means or the map data stored in the first memory in the drawing memory;

display-control means for determining the display area and displaying the display-area data of the drawing area in the drawing memory on the display; and

map-selecting means for selecting a map to be displayed, wherein the map-selecting means switches which of the uncompressed map data or the map data the drawing means draws in the drawing memory.

6. The map display unit according to claim 5, wherein the map-selecting means includes means for determining the velocity of a vehicle and switches the map to be displayed depending on whether the velocity has exceeded a threshold.

7. The map display unit according to claim 5, wherein the compressed map data is raster data and the uncompressed map data is vector data.

10. A map display program, comprising:

reading and decompressing compressed map data stored in a data storage medium;

storing the decompressed map data in a first memory;

drawing the map data stored in the first memory in a drawing memory; and

determining a display area and displaying the display-area data of a drawing area in the drawing memory on a display, wherein in the step of displaying the data on the display, when there is no display-area data in the first memory, the compressed map data including the display area is read out and decompressed from the data storage medium in the step of reading and decompressing the compressed map data.

11. A map display unit, comprising:

storage means for storing raster map data;

environmental-change sensing means for sensing a change in the environment;

control means for changing the color tone of the raster map data depending on the change in environment sensed by the environmental-change sensing means; and

display means for displaying the map data changed by the control means.

12. The map display unit according to claim 11, wherein the map data is divided into blocks and each of the divided raster data has positional information on a representative point.

13. The map display unit according to claim 11, wherein the environmental-change sensing means senses a change in the environment on the basis of the information of the global positioning system (GPS).

14. The map display unit according to claim 11, wherein the environmental-change sensing means determines whether the time is daytime or nighttime depending on whether a vehicle light is lit.

15. The map display unit according to claim 11, wherein the environmental-change sensing means determines the current season on the basis of GPS information.

16. The map display unit according to claim 11, wherein the control means changes the RGB value of the map data on the basis of predetermined color information and transmittance information.

17. The map display unit according to claim 11, wherein the storage means further includes vector map data and current-location-mark information, and the control means overwrites vector map data for a destination guidance route on the raster map data whose color tone has been changed.

18. The map display unit according to claim 11, wherein the control means changes the color tone of the raster map data when the map data is drawn in the drawing memory.

19. The map display unit according to claim 11, wherein the control means changes the color tone of the raster map data drawn in the drawing memory when the map data is outputted to the display means.

20. A map display program for displaying a map on the basis of raster map data stored in storage means and a change in the environment sensed by environmental-change sensing means, comprising:

sensing a change in the environment by the environmental-change sensing means;

changing the color tone of the raster map data depending on the change in the environment sensed in the step of sensing the change in environment; and

displaying the map data changed in the step of changing the color tone.