JPH1068627A - Navigation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lower power consumption by selectively supplying a power source only at a specified timing to a display device and a reading means. SOLUTION: It is sufficient to read a map data from an external memory 10 only when a need arises. A power source of the external memory 10 turned ON only for the operation of reading the map data and, otherwise, it is turned OFF. A power source switch 17 is provided to selectively supply the power source to a display device 12 for showing the position of own vehicle on a display 13 together with a map in the perimeter of the own vehicle based on the map data read out of the external memory 10. This allows stopping of the supply of the power source to the display device 12 while accomplishing accurate recognition of the current location when any navigation operation is required by a user's will thereby enabling lowering of power consumption significantly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a navigation device.

[0002]

2. Description of the Related Art In recent years, digitized map data has been stored in a memory, and while recognizing the current position of a vehicle, map data of a certain range including the current position is read out from the memory to obtain a map around the current position of the vehicle. In-vehicle navigation devices have been developed that project the image on a display and automatically display the position of the vehicle on the map.

In such a navigation device, the map data is digitized data, and a large-capacity semiconductor memory and a high-speed operation are used to display a map around the vehicle on a display based on the data. Display device is indispensable. Therefore, a navigation device having these devices consumes a large amount of power and has a limited power supply capacity of the vehicle. Therefore, it is desired to reduce the power consumption of the navigation device mounted on the vehicle.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to provide a navigation device that can contribute to a reduction in power consumption.

[0005]

According to the present invention, there is provided a navigation apparatus comprising: a recognition unit for recognizing a current position of a vehicle; a reading unit for reading map information from a recording medium; and a display unit for displaying a map based on the map information. A first power supply means for selectively supplying power to the reading means, and a second power supply means for selectively supplying power to the display means.

[0006]

According to the present invention, power can be selectively supplied to the display device and reading means for reading map information, so that the function of unnecessary portions can be stopped while the current location is recognized. The power consumption of the navigation device can be reduced.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention. In the figure, 1 is, for example, geomagnetism (earth magnetic field)
Direction sensor for detecting the running direction of the vehicle by
2 is a distance sensor for detecting the traveling distance of the vehicle, and 3 is a G for detecting the current position of the vehicle from the latitude and longitude information.
It is a PS (Global Positioning System) device, and the detection outputs of these sensors (devices) are supplied to a system controller 4.

A system controller 4 receives an output of each of the sensors (devices) 1 to 3 as an input and performs an A / D (analog / digital) conversion or the like interface
And various sensors (devices) 1-3 sequentially transmitted from the interface 5 while performing various image data processing.
(Central Processing Circuit) 6 for calculating the rate of change of the traveling distance and the traveling azimuth of the vehicle based on the output data of the CPU, and a ROM in which various processing programs of the CPU 6 and other necessary information are previously written. (Read only memory) 7, a RAM (random access memory) 8 for writing and reading information necessary for executing a program, and an external storage device 1 to be described later.
And a drive circuit 9 for driving a power supply relay 11 as a switching means for selectively supplying power to 0. The system controller 4 is directly supplied with power from a battery power supply via a power supply line L.

The external storage device 10 is a read-only nonvolatile storage medium, for example, a large-capacity CD (compact disk).
Disc) -ROM and a CD-ROM decoder for driving this. The external storage device 10 is selectively supplied with power from a power supply line L via a power supply relay 11. CD-RO in external storage device 10
M stores digitized (digitized) map data.

When the vehicle is running, the CPU 6 calculates the azimuth of the vehicle based on the output data of the azimuth sensor 1 at fixed time intervals by a timer interrupt, and calculates the azimuth of the vehicle from the mileage and the azimuth by the interruption of the distance sensor 2. Is obtained from the storage device 10, and the collected data is temporarily stored in the RAM 8 and supplied to the display device 12, and further, from the external storage device 10. The power supply relay 11 is driven via the drive circuit 9 to supply power to the storage device 10 only when the map data is read.

The display device 12 renders a display 13 such as a CRT, a graphic memory 14 such as a V (Video) -RAM or the like, and map data sent from the system controller 4 on the graphic memory 14 as image data. A graphic controller 15 for outputting the image data;
5 based on the image data output from
A display controller 16 for controlling the display of a map on the display 3
It is composed of

The display device 12 is selectively supplied with power from a power supply line L via a power switch 17. When the display of the map on the display 13 is unnecessary, the user can stop the power supply to the display device 12 by turning off (opening) the power switch 17.

The input device 18 comprises a keyboard or the like,
Various commands and the like are issued to the system controller 4 by key input by the user.

Next, a processing procedure for controlling the power supply relay 11 executed by the CPU 6 will be described with reference to the flowchart of FIG.

The CPU 6 first finds the current position of the vehicle based on the output data of the azimuth sensor 1, the distance sensor 2 and the GPS device 3 (step S1), and then stores the current position in the map data RAM 8 in a certain range including the current position. It is determined whether or not the data has been captured (step S2).

If it is determined that the map data around the own vehicle has been taken in, the flow ends without doing anything.

If it is determined that map data around the position of the vehicle has not been captured, the power supply relay 11 is turned on (closed) to supply power to the external storage device 10 (step S3), and the current position of the vehicle is determined. The necessary map data centering on the map data is sequentially read out from the external storage device 10 and loaded into the RAM 8 (step S4). After the loading of the map data is completed, the power supply relay 11 is turned off (open) to supply power to the external storage device 10. Stop. Then, a series of operations ends.

In the navigation device having the external storage device 10, the power consumption is increased and the power supply capacity of the vehicle is limited. In view of this, in the present embodiment, in consideration of the fact that the map data can be read from the external storage device 10 only when it is needed, as described above, the external storage device 10 is read only when the map data is read. The power supply is turned on, and the power supply is turned off otherwise. As a result, the power consumption of the entire navigation device can be reduced.

In the present invention, the external storage device 1
Display 1 based on map data read from 0
3 is provided with a power switch 17 for selectively supplying power to the display device 12 for displaying the position of the vehicle together with a map around the vehicle, so that navigation can be performed according to the user's intention while performing accurate current position recognition. When the operation is not required, the power supply to the display device 12 can be stopped, which can further contribute to reduction in power consumption.

In the case of an in-vehicle navigation device, the current position of a vehicle is often recognized based on map data. In this case, it is necessary to always estimate the current position while the vehicle is running. It is necessary to always supply power to the system controller 4.

[0022]

According to the present invention, power can be selectively supplied to the display device and the reading means for reading map information, so that functions of unnecessary portions can be stopped while the current position is recognized. Therefore, the power consumption of the navigation device can be reduced.

Further, since the present position is always estimated during running, when a navigation operation is required during running, a map around the current position of the vehicle can be displayed immediately after the power is turned on.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a flowchart showing a processing procedure for controlling a power relay.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Orientation sensor 2 ... Distance sensor 3 ... GPS device 4 ... System controller 10 ... External storage device 11 ... Power supply relay 12 ... Display device 17 ...・ Power switch

Claims (4)

[Claims] 1. A recognition device for recognizing a current position of a vehicle, a reading device for reading map information from a recording medium, a display device for displaying a map based on the map information, and selectively supplying power to the reading device. A first power supply means for supplying power to the display means; and a second power supply means for selectively supplying power to the display means. 2. The navigation apparatus according to claim 1, wherein even when power is not supplied to said display means, power is supplied to said recognizing means to recognize a current position. 3. The navigation apparatus according to claim 1, wherein even when power is not supplied to said reading means, power is supplied to said recognizing means to recognize a current position. 4. The navigation device according to claim 1, wherein when the vehicle is running, power is supplied to said recognition means to recognize a current position.