JP2862849B2 - Navigation device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a navigation device. 2. Description of the Related Art In recent years, digitized map data is stored in a memory, and while a current position of the vehicle is recognized, map data of a certain range including the current position is read out from the memory to read the current position of the vehicle. In-vehicle navigation devices have been developed that project a map of the surrounding area 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] 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 reduction of power consumption. [0005] The invention according to claim 1 provides
Reading means for reading map information from a storage medium storing map information; storage means for temporarily storing map information read by the reading means; recognition means for recognizing the current location of the vehicle; And display means for displaying map information from the storage means, power supply means for selectively supplying power to the display means, and determination means for determining update of map information stored in the storage means. Control means for controlling the reading means to read the map information in accordance with the result of the determining means, in order to update the map information in the storage means, wherein the control means comprises: Even when the power supply unit turns off the display unit, the reading unit reads the map information in accordance with the result of the determination unit so as to update the map information in the storage unit. And controlling to take. Further, the invention according to claim 2 is the navigation device according to claim 1, further comprising a power switch for selectively supplying power to the reading means, and The power switch is turned on / off in response to the request. According to the present invention, power can be selectively supplied to the display device, and the function of an unnecessary portion can be stopped while the current position is recognized. The power can be reduced. An embodiment 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 5.
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 written in advance. (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. According to the first aspect of the present invention, the operation state of the reading unit is controlled so that the control unit can stop the function of the unnecessary part while performing the current position recognition, and the unnecessary operation by the reading unit is performed. Can be suppressed. Further, the power supply can be selectively supplied to the display means, and even when power is not supplied to the display means, the control means suppresses unnecessary operations by the reading means and updates the map information in the storage means. Is performed so that the reading means reads the map information in accordance with the result of the determination means, so that the map can be displayed instantaneously when power is supplied to the display means. According to the second aspect of the invention, in addition to the effects of the first aspect, the control means controls the supply of power to the reading means so that unnecessary operations are not performed. The power consumption of the device can be reduced.

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. [Description of Signs] 1 ··· Azimuth sensor 2 ··· Distance sensor 3 ··· GPS device 4 ··· System controller 10 ··· External storage device 11 ··· Power supply relay 12 ··· Display device 17: Power switch

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) G01C 21/00 G08G 1/0969 G09B 29/10

Claims (1)

(57) [Claims] Reading means for reading map information from a storage medium storing map information; storage means for temporarily storing map information read by the reading means; recognizing means for recognizing the current location of the vehicle; Display means for displaying the map information from the storage means; power supply means for selectively supplying power to the display means; and determination means for determining update of the map information stored in the storage means. A control unit that controls the reading unit to read the map information in accordance with a result of the determination unit so as to update the map information in the storage unit, wherein the control unit includes: Even when the power supply unit turns off the display unit, the reading unit sets the map information in accordance with the result of the determination unit so as to update the map information in the storage unit. A navigation device that controls to read information. 2. 2. The navigation device according to claim 1, further comprising a power switch for selectively supplying power to said reading means, wherein said control means switches on / off of said power switch in accordance with a result of determination by said determination means. A navigation device characterized by the above-mentioned.