U.S. patent application number 10/633684 was filed with the patent office on 2004-02-26 for power management system for a communication device.
This patent application is currently assigned to AISIN AW CO., LTD.. Invention is credited to Naitou, Mitsuhiro, Ogawa, Satoshi, Yamada, Kunihiro.
Application Number | 20040039951 10/633684 |
Document ID | / |
Family ID | 30447684 |
Filed Date | 2004-02-26 |
United States Patent
Application |
20040039951 |
Kind Code |
A1 |
Naitou, Mitsuhiro ; et
al. |
February 26, 2004 |
Power management system for a communication device
Abstract
A power management system for a communication device, including
an accessory-signal generating device; the communication device;
and a power management device for supplying electric power to the
communication device if the accessory-signal generating device is
not generating accessory signals and the communication device is in
a communication-ready state.
Inventors: |
Naitou, Mitsuhiro; (Okazaki,
JP) ; Yamada, Kunihiro; (Okazaki, JP) ; Ogawa,
Satoshi; (Okazaki, JP) |
Correspondence
Address: |
OLIFF & BERRIDGE, PLC
P.O. BOX 19928
ALEXANDRIA
VA
22320
US
|
Assignee: |
AISIN AW CO., LTD.
Aichi
JP
|
Family ID: |
30447684 |
Appl. No.: |
10/633684 |
Filed: |
August 5, 2003 |
Current U.S.
Class: |
713/300 |
Current CPC
Class: |
Y02D 30/70 20200801;
H04W 52/028 20130101 |
Class at
Publication: |
713/300 |
International
Class: |
G06F 001/26 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 9, 2002 |
JP |
2002-232656 |
Aug 9, 2002 |
JP |
2002-232699 |
Claims
What is claimed is:
1. A power management system for a communication device,
comprising: an accessory-signal generating device; the
communication device; and a power management device for supplying
electric power to the communication device if the accessory-signal
generating device is not generating accessory signals and the
communication device is in a communication-ready state.
2. The power management system according to claim 1, wherein the
power management device supplies electric power to the
communication device if there exists an access point through which
communication with the communication device is established.
3. The power management system according to claim 2, wherein the
access point authenticates the communication device.
4. The power management system according to claim 3, wherein the
power management device supplies electric power to the
communication device if a volume of communication traffic between
the communication device and the access point is greater than a
predetermined volume.
5. The power management system according to claim 2, wherein the
power management device supplies electric power to the
communication device if a volume of communication traffic between
the communication device and the access point is greater than a
predetermined volume.
6. The power management system according to claim 2, wherein the
power management device determines whether the communication device
is in a communication-ready state at substantially the instant that
the accessory-signal generating device is turned off.
7. The power management system according to claim 2, wherein the
communication device is a wireless LAN.
8. The power management system according to claim 1, wherein the
power management device determines whether the communication device
is in a communication-ready state at substantially the instant that
the accessory-signal generating device is turned off.
9. A power management system for a communication device,
comprising: an accessory-signal generating device; a first
communication device; a second communication device; a power
management device for supplying electric power to the second
communication device if the accessory-signal generating device is
not generating accessory signals and the first communication device
is in a communication-ready state; and a startup management device
for activating at least the first communication device upon receipt
of startup-signals from the second communication device.
10. The power management system according to claim 9, wherein the
power management device supplies electric power to the second
communication device when there is an access point through which
communication with the first communication device is
established.
11. The power management system according to claim 10, wherein the
access point authenticates the first communication device.
12. The power management system according to claim 11, wherein the
power management device supplies electric power to the first
communication device if a volume of communication traffic between
the first communication device and the access point is greater than
a predetermined volume.
13. The power management system according to claim 10, wherein the
power management device supplies electric power to the first
communication device if a volume of communication traffic between
the first communication device and the access point is greater than
a predetermined volume.
14. The power management system according to claim 10, wherein the
power management device determines whether the first communication
device is in a communication-ready state at substantially the
instant that the accessory-signal generating device is turned
off.
15. The power management system according to claim 10, wherein the
first communication device is a wireless LAN.
16. The power management system according to claim 10, wherein the
second communication device is a specific low-power radio
communication device.
17. The power management system according to claim 9, wherein the
power management device determines whether the first communication
device is in a communication-ready state at substantially the
instant that the accessory-signal generating device is turned
off.
18. The power management system according to claim 9, further
comprising: a storage device for storing data transmitted from the
first communication device, wherein, the startup management device
activates the first communication device and the storage device
upon receipt of the startup-signals from the second communication
device.
19. The power management system according to claim 9, wherein the
startup-signals are generated by the second communication device
when the second communication device receives a transmission from a
remote device.
20. A method for managing a power supply for communication device,
comprising; determining if an accessory-signal generating device is
generating accessory signals; determining if the communication
device is in a communication-ready state; and if the
accessory-signal generating device is not generating accessory
signals and the communication device is in a communication-ready
state, supplying electric power to the communication device.
21. A method for managing a power supply for a communication
device, comprising: determining if an accessory-signal generating
device is generating accessory signals; determining if the first
communication device is in a communication-ready state; sending
startup signals from the second communication device to a startup
management device; and if the accessory-signal generating device is
not generating accessory signals and the first communication device
is in a communication-ready state, activating at least the first
communication device upon the startup management device receiving
the startup signals.
Description
INCORPORATION BY REFERENCE
[0001] The disclosures of Japanese Patent Application No.
2002-232656 filed Aug. 9, 2002, and Japanese Patent Application No.
2002-232699 filed Aug. 9, 2002, including the specifications,
drawings and claims are incorporated herein by reference in their
entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] The invention relates to a power management system for a
communication device.
[0004] 2. Description of Related Art
[0005] There are conventional on-board navigation systems, wherein
route guidance data is preliminarily transmitted to the on-board
navigation system prior to a user's departure and the user is
provided with route guidance based on the transmitted route
guidance data at his or her departure (please refer to Japanese
patent laid-open H6-243395 and H9-189566.) In this conventional
system, the user operates a personal computer at home or at work in
order to input a destination, a route search criterion, and the
like. As a result, a route is searched and route guidance data is
transmitted to a navigation apparatus over wireless communication.
With such conventional system, the user is provided with the route
guidance from the beginning of his or her drive. However,
inconveniently, inputting a destination, a route search criterion,
and the like; searching the route; and transmitting the data must
be carried out while the vehicle is stopped or parked.
SUMMARY OF THE INVENTION
[0006] In the conventional systems, an on-board vehicle navigation
apparatus or an on-board audio apparatus is designed to receive
data while the vehicle is parked and the power thereof is off. In
order to receive the data, however, the on-board apparatus must be
powered. Usually when the vehicle is parked, both the engine of the
vehicle and an alternator attached thereto are stopped. Therefore,
a vehicle battery is used as a power supply for the on-board
apparatus. However, the capacity of the vehicle battery is limited
and there is a possibility that the battery will die if the
on-board apparatus is only powered by a vehicle battery. This is a
problem with the conventional system.
[0007] For solving the above-described problems peculiar to the
conventional systems, the invention provides a new system, wherein
the flow of electric power to the communication device is
controlled when no accessory-signal is generated. Such control
minimizes the power consumption of the communication device,
reducing a discharge of the electric power supplied from the
vehicle battery.
[0008] Therefore, the invention provides a power management system
for a communication device, including an accessory-signal
generating device; the communication device; and a power management
device for supplying electric power to the communication device if
the accessory-signal generating device is not generating accessory
signals and the communication device is in a communication-ready
state.
[0009] Furthermore, the invention provides a power management
system for a communication device, including an accessory-signal
generating device; a first communication device; a second
communication device; a power management device for supplying
electric power to the second communication device if the
accessory-signal generating device is not generating accessory
signals and the first communication device is in a
communication-ready state; and a startup management device for
activating at least the first communication device upon receipt of
startup-signals from the second communication device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Embodiments according to the invention will be described
hereinafter in detail with reference to the accompanying drawings,
wherein:
[0011] FIG. 1 illustrates composition of a power management system
for a communication device according to a first embodiment of the
present invention;
[0012] FIG. 2 illustrates composition of a communication system
wherein a vehicle navigation apparatus and an operating terminal
are communicated with each other according to the first embodiment
of the present invention;
[0013] FIG. 3 illustrates composition of a vehicle navigation
apparatus serving as an on-board apparatus according to the first
embodiment of the present invention;
[0014] FIG. 4 is a flowchart showing the operation of a power
management system for the communication device having no function
of user-authentication, according to the first embodiment of the
present invention;
[0015] FIG. 5 is a flowchart showing the operation of a power
management system for the communication device having a function of
user-authentication, according to the first embodiment of the
present invention;
[0016] FIG. 6 is a flowchart showing process of the startup
management according to the first embodiment of the present
invention; and
[0017] FIG. 7 illustrates composition of a power management system
for a communication device according to a second embodiment of the
present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0018] FIG. 2 illustrates the composition of a communication system
wherein a vehicle navigation apparatus and an operating terminal
are communicated with each other according to a first embodiment of
the invention.
[0019] FIG. 2 shows a vehicle navigation apparatus 15 aboard a
passenger vehicle, a truck, a bus, or a motorcycle. A wireless LAN
(Local Area Network) device 58 is coupled to an interface 63 in the
vehicle navigation apparatus 15. The wireless LAN device 58 is, for
example, a wireless LAN card. The interface 63 is, for example, a
card slot to which the wireless LAN card is loaded. The wireless
LAN device 58 may be preliminarily built in the vehicle navigation
apparatus. In the interest of the simplicity, the detailed
composition of the vehicle is omitted from FIG. 2. However, there
is shown a vehicle battery serving as a main electric power supply
55. The main electric power supply 55 is coupled to the vehicle
navigation apparatus 15, so as to supply the vehicle navigation
apparatus 15 with electric power. Further there is shown an
accessory-signal generating device 56 to generate accessory-signals
that could be received by the vehicle navigation apparatus 15. The
vehicle navigation apparatus 15 is activated upon receipt of the
accessory-signals.
[0020] FIG. 2 shows the communication system while the vehicle (not
shown) is parked at a user's garage 62 owned by any one of a
driver, a fellow passenger, and an owner of the vehicle. Further,
there shown in FIG. 2, a user's house 61, furnished with a radio
communication device 65, serving as an access point through which
communication with the wireless LAN device 58 is established under
a wireless LAN system. Either the user's garage 62 or the user's
house 61 furnished with the radio communication device 65 is
registered as a registered point with a power management unit 59
(described later). In the registration, the user's garage 62 and
the user's house 61 are classified into a category "House."
[0021] The radio communication device 65 is, for example, a
wireless LAN adaptor by which communication with the vehicle
navigation apparatus 15 is established under the wireless LAN
system at, for example, an ISM frequency band (2.4[GHz]), a
frequency band (5.2[GHz]), a quasi-extremely high frequency band
(19[GHz]), or infrared rays. Here, the wireless LAN system can be
one of conforming to IEEE standards, for example, IEEE802.11a,
IEEE802.11b, IEEE802.11e, or IEEE802.11g. Alternatively, the
wireless LAN system can be one of adopting "Bluetooth" the personal
home-use radio communication system.
[0022] In most cases, the main electric power supply 55 is a
vehicle battery. However, the main electric power supply 55 is not
limited to such a case. The main electric power supply 55 may be a
double-layer electrolytic capacitor, a fuel cell, or the like.
Although voltage applied to open terminals on the main electric
power supply 55, serving as the vehicle battery, can be any
voltage, the description here, for example, assumes a 12v-vehicle
battery for a compact car. While the engine is running, the
alternator, attached to the engine, can charge the main electric
supply 55 with the electric power. The main electric power supply
55 is not supplied with the power from the alternator when the
engine is stopped.
[0023] Under the ordinary wireless LAN system, in which
communication between the wireless LAN device 58 and the radio
communication device 65 is established, communication coverage is
typically inside a 10 m-radius to 100 m-radius of the radio
communication device 65. To communicate with the radio
communication device 65, the wireless LAN device 58 should be
within the coverage range.
[0024] An operating terminal 14 is a kind of a user-operable
computer, comprising main operation means, such as a CPU or a MPU;
storage means, such as a semiconductor memory or a magnetic disk;
display means, such as a liquid crystal display, a LED (Light
Emitting Diode) display, or a CRT; input means, such as a keyboard,
a joystick, a touch panel, a tablet, a push-button, a rotary dial,
or a remote control; and an input/output interface. The operating
terminal 14 may be any of the following: a personal computer, a
stationary telephone, a portable telephone, a personal handy phone
(used in PHS: Personal Handy-Phone System constructed by NTT, or
Nippon Telegraph and Telephone Corporation), a PDA (Personal
Digital Assistant), an electronic hand-held organizer, a portable
information terminal, a game machine, a digital television, or the
like. The operating terminal 14 is connected to the radio
communication device 65 over a wired line or wirelessly, whereby it
may communicate with the vehicle navigation apparatus 15 via the
radio communication device 65.
[0025] According to the invention, a cellular terminal used in a
cellular mobile phone system may be employed in place of the
wireless LAN device 58 and the radio communication device 65. Here,
the cellular mobile phone system can be any one of the following: a
first-generation cellular mobile phone system, a second-generation
cellular mobile phone system, a third-generation cellular mobile
phone system, IMT-2000, or the like. These systems are generically
described as a mobile communication system wherein communication is
established through a cellular terminal such as a cellular phone or
the personal handy phone for PHS. The cellular terminal may be a
mobile phone that uses a prepaid-card. Under the ordinary mobile
communication system, the vehicle navigation apparatus 15 and the
operating terminal 14 communicate with each other over a general
mobile phone network or PHS network. To establish communication
between the vehicle navigation apparatus 15 and the operating
terminal 14, the cellular terminal should be within the
communication coverage of a base station in the cellular phone
system.
[0026] For communication with the vehicle navigation apparatus 15,
the operating terminal 14 is designed to be accessible to a network
51. The network 51 may be, for example, any one of the following
communication lines: the Internet, a LAN, a WAN (Wide Area
Network), an intranet, a wired/wireless public switched
communication line network, a dedicated communication line network,
or a certain combined network comprised of the various networks. It
is desirable that the user can access a web server, acting as an
information provision device that provides various data such as
cartographic data, music data, image data, or text data, via the
network 51. For such data, it is desirable that the network 51
should support a high-capacity high-speed transmission system. For
example, if the network 51 is the Internet, a broadband network
with data transfer rates in excess of at least one Mbps (Mega bit
per second) is preferable. However, the high-capacity high-speed
transmission system is not limited to such a broadband network. Any
kind of high-capacity high-speed transmission system or method may
be applicable to the invention.
[0027] When the operating terminal 14 is accessible to the network
51, the radio communication device 65 serves as a relay between the
operating terminal 14 and the vehicle navigation apparatus 15.
Alternatively, the radio communication device 65 works as an access
point through which the vehicle navigation apparatus 15 is
authenticated to the network 51.
[0028] FIG. 2 further shows an application server 52 that is
accessible from the network. The application server 52 is a kind of
computer comprising arithmetic means, such as a CPU or a MPU;
storage means, such as a semiconductor memory or a magnetic disk;
display means, such as a CRT, a liquid crystal display, or a LED
(Light Emitting Diode) display; input means, such as a keyboard, a
touch-sensitive panel, a tablet, a push-button, or a mouse; and a
input-output interface. The application server 52 may be, for
example, a web server on the Internet. However, the application
server 52 is not limited to the web server. Rather, it may be a
personal computer, a workstation, or any other kind of computer.
Furthermore, the application server 52 is not limited to the single
computer, but may be a so-called a decentralized server in which a
plurality of computers are systematically connected one after the
other. Further, the application server 52 may be one of the systems
constructed within a mainframe computer. The application server 52
distributes the following data, programs, and software programs:
navigational data comprised of the cartographic data, road data,
photographic data, and facility data about facilities, such as
hotels, service stations, and tourist information centers, all of
which are used in the vehicle navigation apparatus 15; update
programs for the vehicle navigation apparatus 15; a personal
information management software program usable in the vehicle
navigation apparatus 15; and application programs such as game
software and entertainment software like music data and video
data.
[0029] When the application server 52 functions to search for a
route, retrieve a point or facilities, and the like, it is possible
for the operator to input from the operating terminal 14 a
departure point and a destination, and define search criteria and
retrieval criteria, in order that the application server 52 might
carry out the search, retrieval, and the like. The results of the
route search and the point or facilities retrieval can be
transmitted back to the operating terminal 14.
[0030] Data can be downloaded together with the search results and
the retrieval results to the apparatus 15 by actuating the
operating terminal 14. Here, the data includes the navigational
data, the update program, and the application programs such as game
software and entertainment software.
[0031] If the application server 52 is able to distribute the
navigational data, for example, the latest version cartographic
data, it is possible for the user to download his or her desired
cartographic data from the application server 52 to the operating
terminal 14 over the network 51. Furthermore, such cartographic
data, downloaded into the operating terminal 14, can be transferred
to the vehicle navigation apparatus 15 through the radio
communication device 65 and therewith the old cartographic data,
having already been stored in the apparatus 15, is updated.
Otherwise, the cartographic data can be downloaded directly from
the application server 52 to the vehicle navigation apparatus 15
without having to use the operating terminal 14.
[0032] If the vehicle navigation apparatus 15 is able to rewrite a
startup program, the latest startup program can be downloaded to
the vehicle navigation apparatus 15 from the application server 52.
If the vehicle navigation apparatus 15 functions as an onboard
audio device, the user may edit and compile his or her favorite
music by manipulating the operating terminal 14 and then store the
compiled music into the vehicle navigation apparatus 15. If the
application server 52 distributes music, it is possible for the
user to download his or her favorite music from the application
server 52 to the operating terminal 14 over the network 51.
Furthermore, the music downloaded to the operating terminal 14 can
be transferred to the vehicle navigation apparatus 15 through the
radio communication device 65, and therewith the music can be
downloaded and stored into the vehicle navigation apparatus 15.
Otherwise, the music is downloaded directly from the application
server 52 to the vehicle navigation apparatus 15 without using the
operating terminal 14.
[0033] If the vehicle navigation apparatus 15 functions as a
playback device that can replay still-frame images or video images,
the image data may be stored into the vehicle navigation apparatus
15 just as in the case of storing the music data. Specifically, the
still-frame images or the video images taken with a digital camera
or a video camera can be transferred from the operational terminal
14 and stored into the vehicle navigation apparatus 15.
[0034] Furthermore, if the vehicle navigation apparatus 15 is
capable of organizing and displaying a timetable or a schedule, the
timetable or schedule organized by using the personal information
management software program is transferred from the operating
terminal 14 and stored into the vehicle navigation apparatus
15.
[0035] Even if the vehicle is parked in a place other than the
user's garage 62, it is possible to download data to the vehicle
navigation apparatus 15. Here, assume that the vehicle is parked at
a parking lot (for example, a parking lot of a commercial facility,
such as a department store, a supermarket, or a convenience store;
a parking lot of recreational facility, such as an amusement park
or a game center; a parking lot of a fast-food restaurant or a
coffee shop; a parking lot of public transportation, such as a
railroad station or an airport; and a parking lot of a gas station)
provided with a wireless communication device similar to the radio
communication device 65 that is communicable with the network 51.
Here, just as in the case where the vehicle is parked in the user's
garage 62, the cartographic data, the music, the video data, or the
like can be downloaded from the application server 52 to the
vehicle navigation apparatus 15 over the wireless LAN. This allows
the user to download his or her desired data to the vehicle
navigation apparatus 15 even if the or she is away from home.
[0036] Furthermore, if the parking lot is a toll car park, that is
provided with the wireless communication device communicable with a
central computer that controls the toll car park and compiles data
as to both time and charges for parking, such data can be
downloaded from the wireless communication device to the vehicle
navigation apparatus 15.
[0037] If the central computer provides information about the
facilities such as a department store or an amusement park located
around the toll car park, the facility information may include a
map of the facility, information about or a grand sale day or a
free gift offered by the facility, business hours of the facility,
and an area for special sales within the facility. These pieces of
information can be downloaded to the vehicle navigation apparatus
15 over the wireless LAN. Thus, the user may be provided with the
information about the various facilities located around the toll
car park.
[0038] Further, assume that the vehicle is parked in a roadside
parking space provided with a wireless communication device like
the radio communication device 65 that is communicable with the
network 51. Again, just as in the case where the vehicle is parked
in the user's garage 62, the cartographic data, the music, the
video data, or the like can be downloaded from the application
server 52 to the vehicle navigation apparatus 15 over the wireless
LAN. This allows the user to download his or her desired data to
the vehicle navigation apparatus 15 even if he or she is away from
home.
[0039] Additionally, assume that the vehicle is parked in a parking
lot of the user's office and the parking lot is provided with a
wireless communication device like the radio communication device
65 communicable with the network 51. Once again, just as in the
case where the vehicle is parked in the user's garage 62, the
cartographic data, the music, the video data, or the like can be
downloaded from the application server 52 to the vehicle navigation
apparatus 15 over the wireless LAN. This allows the user to
download his or her desired data to the vehicle navigation
apparatus 15 even during his or her working hours.
[0040] Next, the composition of the vehicle navigation apparatus 15
according to the first embodiment will be detailed with reference
to FIG. 3. FIG. 3 illustrates the vehicle navigation apparatus 15,
serving as a kind of computer, comprising a vehicle positional
information output unit 18, by which a present position of the
vehicle is detected and the positional information of the vehicle
is outputted; a data storage unit 16, serving as storage medium on
which road data and so on are stored; a navigation-processing unit
17, by which arithmetic processing is carried out based on inputted
information; an input unit 34; a display unit 35; a voice input
unit 36; a voice output unit 37; and a communication unit 38.
Additionally, a vehicle-speed sensor 41 is coupled to the
navigation-processing unit 17.
[0041] The vehicle positional information output unit 18 comprises
a GPS (Global Positioning System) sensor 21, a terrestrial
magnetism sensor 22, a distance sensor 23, a steering sensor 24, a
beacon sensor 25, a gyro sensor 26, and an altimeter (not shown).
As one thinks proper, one or more of these components may be left
out from the vehicle positional information output unit 18 in view
of production costs.
[0042] The GPS sensor 21 detects a present position of the vehicle
on the surface of the Earth by receiving radio waves generated by
artificial satellites. The terrestrial magnetism sensor 22 detects
vehicle bearings by measuring the terrestrial magnetism. The
distance sensor 23 detects a distance between one specific position
and another position on a road. The distance sensor 23 may be one
of measuring a rotational frequency of wheels, whereby a distance
is detected. Alternatively, the distance sensor 23 may be one of
measuring acceleration of the vehicle so as to detect a distance by
integrating twice the measured acceleration.
[0043] The steering sensor 24 detects a steering angle. The
steering sensor 24 may be, for example, any one of the following
sensors fixed to a rotating-part of the wheels: an optical
rotational sensor, a rotational resistance sensor, or an angle
sensor.
[0044] The beacon sensor 25 detects the present position of the
vehicle by receiving positional information transmitted from the
beacons placed along roads. The gyro sensor 26 detects rotational
angular speed (traverse angle) by using a gas-rate gyro, a
vibrating gyro, or the like. By integrating the detected rotational
angular speed, the vehicle's bearing can be detected.
[0045] The present position can be detected by means of the GPS 21
alone or the beacon sensor 25 alone. In other circumstances, the
present position may be detected based on a combination of the
distance, the vehicle bearing, and the rotational angular speed
respectively detected by the distance sensor 23, the terrestrial
magnetism sensor 22, and the gyro sensor 26. Furthermore, the
present position may be detected based on a combination of the
distance and the steering angle respectively detected by the
distance sensor 23 and the steering sensor 24.
[0046] The data storage unit 16 has a database comprised of the
following data files: a cartographic data file, an intersection
data file, a node data file, a road data file, a photographic data
file, and a facility information data file (information about
hotels, service stations, tourist information centers, and so on).
Furthermore, the data storage unit 16 contains the following data:
data for searching for a route, data for visually providing the
operator with route guidance onto the screen in the display unit
35, data for displaying pictures or frame shots of the
intersections and/or the routes, data for indicating distance to
the next intersection or indicating a direction to be taken at the
next intersection, data for displaying various guidance information
onto a screen, and the like. Furthermore, the data storage unit 16
contains some data used in outputting predetermined information
from the voice output unit 37.
[0047] The intersection data file contains intersection data
concerning respective intersections. The node data file contains
node data concerning node points located along roads. The road data
file contains road data concerning respective roads and/or road
links. Based on the data in the intersection data file, the node
data file, and the road data file, a state of the road is indicated
on the screen. The intersection data may include intersection type
data that represents the type of the intersection. The intersection
type is, for example, an intersection with traffic lights or an
intersection without traffic lights. The node data consists of
sub-data about road junctions (including intersections and T-square
intersections), node points, and node links connecting respective
nodes with each other. The node points can represent at least a
location of a curve point.
[0048] The road data concerns data about the road itself, e.g.,
width, gradient, cants, elevation, banks, corners, road surface
conditions, existence of a center divider (center strip), the
number of traffic lanes, a point where the number of the traffic
lanes is reduced, a point where the width of the road is narrowed.
In the case of the expressways or arterial roads having up-lanes
and down-lanes, such up-lanes and down-lanes are separately
contained in the road data file, and therewith such expressways or
arterial roads are determined to be a two-way road. Specifically,
when the expressway in which both the up-lane and the down-lane
respectively have more than one lane, such expressway is determined
to be a two-way road. In this case, the up-lanes and the down-lanes
are separately contained in the road data. As for the corners of
the road, it is desirable that the road data should contain
detailed data as to a curvature radius of the corner, a corner of
the intersection, a corner of a T-square intersection, and an
entrance to a corner. Further, the road data may contain the
following road attributes: a railroad crossing, an expressway
entrance or exit ramp, a tollgate, a climbing lane, and a descent
lane, road types (national highways, principal municipal roads,
local minor roads, expressways), and the like.
[0049] The navigation-processing unit 17, includes: a processor 31,
serving as an arithmetic processing means such as a CPU or MPU to
control the vehicle navigation apparatus 15 as a whole; a RAM
(Random Access Memory) 32, serving as a working memory when the
processor 31 processes various data; and a ROM (Read Only Memory)
33, serving as a storage medium for storing navigational programs
such as a control program, a program for searching a route to a
destination, a program for carrying out route guidance along a
route, a program for determining a specific road segment, and a
program for retrieving a certain point or a facility. The input
unit 34, the display unit 35, the voice input unit 36, the voice
output unit 37, and the communication unit 38 are all coupled to
the navigation processing unit 17. According to this composition,
various navigational processes may be carried out including route
searches, guidance along routes, determination of a specific road
segment, retrieval of a point, or retrieval of a facility. As one
thinks proper, at least one of the input unit 36 and the output
unit 37 may be left out from previously described first embodiment
in view of production costs.
[0050] A computer-readable storage medium, that stores the
navigational programs, can be employed in the navigation apparatus
in addition to the ROM 33 and may be any one of the following: a
magnetic core, a semiconductor memory, a magnetic tape, a magnetic
disk, a magnetic drum, a CD-R/RW, an MD (Mini Disk), a DVD-RAM, a
DVD-R/RW, an MO (magneto-optical) disk, an IC card, an optical
card, a memory card, or any other possible media.
[0051] Furthermore, each of the data storage unit 16 and the ROM 33
consists of a magnetic core, a semiconductor memory, and the like.
However, each of the data storage unit 16 and the ROM 33 is not
limited to such a case. Each of the storage unit 16 and the ROM 33
may be any one of the following: a magnetic tape, a magnetic disk,
a magnetic drum, a CD-R/RW, an MD, a DVD-RAM, a DVD-R/RW, an MO
disk, an IC card, an optical card, a memory card, or any other
possible medium. These storage media may be stationary or
user-installable.
[0052] According to the first embodiment, the ROM 33 and the data
storage unit 16 respectively store the programs and the data.
However, the invention is not limited to such a case. Both the
programs and the data may be stored together in a single external
storage medium. In this case, for example, the programs and the
data are read out from the single external storage medium and then
written into a flash memory (not shown) in the
navigation-processing unit 17. Both the programs and the data in
the flash memory can be updated by swapping one external storage
medium for another. Based on the programs and data stored in the
various storage mediums, the various navigational processing is
carried out. The external storage medium may be any one of the
following: a magnetic tape, a magnetic disk, a magnetic drum, a
CD-R/RW, an MD, a DVD-RAM, a DVD-R/RW, an MO disk, an IC card, an
optical card, a memory card, or any other possible medium.
[0053] As shown in FIG. 2, the vehicle navigation apparatus 15 and
the operating terminal 14 are connected with each other via the
radio communication device 65 so that bi-directional communication
can be established between them. As shown in FIG. 2, the
communication unit 38 in the vehicle navigation apparatus 15 is
provided with a card expansion slot that serves as the interface 63
for this bi-directional communication. In such case, a wireless LAN
card (not shown) serving as the wireless LAN device 58 could be
loaded to the communication unit 38. The communication unit 38 and
the radio communication device 65 are communicated with each other
via the wireless LAN card. Furthermore, the communication unit 38
can include an information sensor (not shown). By means of the
information sensor, the communication unit 38 can receive various
data, for example, traffic information such as traffic congestion
information, traffic accidents information, and D-GPS information
to be used in finding an error in detection by the GPS 21.
Moreover, according to a second embodiment (described later), the
communication unit 38 may be provided with a specific low-power
radio communication device (not shown).
[0054] According to the first embodiment, when the data distributed
from the application server 52 is received in the communication
unit 38, such received data is downloaded onto the storage medium,
for example, a readable/writable memory such as the RAM 32, the
flash memory, or a hard disk in the vehicle navigation apparatus
15. Otherwise, according to the first embodiment, the data
distributed from the application server 52 may be downloaded to the
operating terminal 14 (shown in FIG. 2), and then that data is
transferred from the operating terminal 14 and stored onto the
storage medium in the vehicle navigation apparatus 15.
[0055] Returning to FIG. 3, the input unit 34 comprises, for
example, an operation key, a push-button, a rotary-dial button,
and/or a cross-key, each of which are located on the body of the
vehicle navigation apparatus 15. Alternatively, the input unit 34
may be a remote control unit. With the operation of keys or
buttons, a position on departure is calibrated and a facility or
destination is input. If the display unit 35 is a touch-sensitive
panel, it is desirable that the input unit 34 should take the
displayable form including operation switches, such as the
operation keys or operation menus. Therefore, input can be done at
the touch of those switches on the touch-sensitive panel.
[0056] The screen in the display unit 35 displays operation
guidance, operation menus, operation keys explanation, a searched
route from a present position to the destination, and guidance
information along the searched route. The display unit 35 may be,
for example, a CRT display, a liquid crystal display, a LED
display, or a plasma display. Alternatively, the display unit 35
may be one of using a hologram device that projects a hologram onto
a windshield of the vehicle.
[0057] The voice input unit 36, from which necessary information is
inputted by voice comprises a microphone and related structure (not
shown). The voice output unit 37 includes a voice synthesizer and a
speaker (both not shown) and outputs synthesized voice information
from the speaker to the operator. Here, the synthesized voice
information includes the guidance information, speed-change
information, and other navigation related information. The speaker
outputs not only the synthesized voices but also various sounds
including any guidance-related information prerecorded on a tape or
a memory.
[0058] Hereinafter, a power management system for a communication
device according to embodiments of the invention will be
described.
[0059] FIG. 1 shows the composition of the power management system
for a communication device, focusing on activation control of each
device in the vehicle navigation apparatus 15 under the power
management system. FIG. 1 shows a startup management unit 74
serving as a gate circuit that controls the activation of each
device in the vehicle navigation apparatus 15. The startup
management unit 74 further carries out a voltage transformation
process in which voltage of the electric power supplied from the
main electronic power supply 55 is transformed. As a result, each
device in the vehicle navigation apparatus 15 is provided with such
voltage-transformed electric power.
[0060] Further, FIG. 1 shows a storage device 72 working as a
data-receipt processing device in which the data downloaded to the
vehicle navigation apparatus 15 is stored. According to the first
embodiment, the storage device 72 may be a hard disk including the
magnetic disks, a DRAM (Dynamic Random Access Memory), a flash
memory, or the like. Other devices 73 represent the components,
except the processor 31, the input unit 34, the display unit 35,
and the storage device 72, in the vehicle navigation apparatus
15.
[0061] FIG. 1 shows a power input line 42a along which the electric
power flows from the main electronic power supply 55 into the
startup management unit 74 and a power output line 42b along which
the voltage-transformed electric power flows from the startup
management unit 74 into each of the processor 31, the input unit
34, the display unit 35, the storage device 72, and the other
devices 73. Further, FIG. 1 shows an accessory-signal input line
43a along which accessory-signals are transmitted from an
accessory-signal generating device 56 to the startup management
unit 74, and an accessory-signal output line 43b along which the
accessory-signals are transmitted from the startup management unit
74 to each of the processor 31, the input unit 34, the display unit
35, the storage device 72, and the other devices 73. Furthermore,
FIG. 1 shows a communication-signal input line 44a along which
in-communication signals are transmitted from the wireless LAN
device 58 to the startup management unit 74, as well as a
startup-signal output line 44b along which the startup-signals are
transmitted from the startup management unit 74 to the storage
device 72. Moreover, FIG. 1 shows a data line 45 and an electric
power input line 46. Data sent from the radio communication device
65 to the wireless LAN device 58 is transmitted along the data line
45 to the storage device 72. The electric power flows from the main
electronic power supply 55 to a power management unit 59 along the
electric power input line 46.
[0062] According to the first embodiment, a voltage of about 12
volts, sent along the power input line 42a from the main electronic
power supply 55, and the startup management unit 74, is transformed
to, for example, a voltage of about 5 volts suited for operating
each of the processor 31, the input unit 34, the display unit 35,
the storage device 72, and the other devices 73. The transformed
voltage is sent along the power output line 42b into each of the
processor 31, the input unit 34, the display unit 35, the storage
device 72, and the other devices 73.
[0063] The accessory-signal generating device 56, installed in the
vehicle, is designed to generate accessory-signals when switched on
by the user. Usually, a switch of the accessory-signal generating
device 56 is integrated with an engine switch of the vehicle.
Therefore, when the user switches on the accessory-signal
generating device 56, the engine is started. If need be, the
accessory-signal generating device 56 is designed to be switched on
separately from the engine. Once switched on, the accessory-signal
generating device 56 starts to generate the accessory-signals. The
startup management unit 74, receiving the accessory-signals
transmitted along the line 43a, determines that the startup-signals
for activating the vehicle navigation apparatus 15 are inputted.
Upon this determination, the startup management unit 74 starts to
transmit the accessory-signals along the accessory-signal output
line 43b to each of the processor 31, the input unit 34, the
display unit 35, the storage device 72, and the other devices
73.
[0064] In detail, the accessory-signals are direct current, e.g., a
constant voltage of about 5 volts. All of the processor 31, the
input unit 34, the display unit 35, the storage device 72, and the
other devices 73 are activated only when the electric power flows
along the power output line 42b from the startup management unit 74
into them. At the same time, the accessory-signals are transmitted
along the accessory-signal output line 43b. All of the processor
31, the input unit 34, the display unit 35, the storage device 72,
and the other devices 73 are deactivated when either the flow of
the electric power or the transmission of the accessory-signal into
them is interrupted.
[0065] The wireless LAN device 58 is under control of the power
management unit 59. Thereby, the wireless LAN device 58 can be
activated whether the accessory-signal generating device 56 is on
or off. For example, take a case where the wireless LAN device 58
is a wireless LAN card. In this case, the wireless LAN card being
inserted to the interface 63 is automatically activated. The
wireless LAN device 58 is switched into an intermittent deactivated
state when the accessory-signal generating device 56 is off. Under
the intermittent standby state, even if there is no communication
with the radio communication device 65, the wireless LAN device 58
can be intermittently activated in order to receive the signals
generated by the radio communication device 65. That is, the
wireless LAN device 58 is activated and deactivated cyclically
under the intermittent standby state. If the wireless LAN device 58
does not receive the signals from the radio communication device 65
during a predetermined activation time, for example, about a half
of a second, the device 58 is switched into the deactivated state
for a predetermined time, for example, about a half of a second.
Therefore, the wireless LAN device 58 is activated and deactivated
at a certain intermittent intervals. Intermittent activation will
lead to the reduction of power consumption. The intermittent
intervals, i.e., activation and deactivation time of the wireless
LAN device 58, can be varied at the user's discretion. For example,
the intermittent intervals can be set from 0.5-second intervals to
5-second intervals.
[0066] If the wireless LAN device 58 receives signals from the
radio communication device 65 during the activation time, the
wireless LAN device 58 is switched from the intermittent standby
state to a continuous activation state. Under the continuous
activation state, the wireless LAN device 58 is continuously
activated so as to communicate with the radio communication device
65. Upon being activated, the wireless LAN device 58 transmits the
in-communication signals along the communication-signal input line
44a to the startup management unit 74 indicating the
in-communication signals indicate that the LAN device 58 is being
activated upon receipt of the signals from the radio communication
device 65.
[0067] For the convenience of explanation of the first embodiment,
the description takes a case where the wireless LAN device 58 is a
wireless LAN card. When the accessory-signal generating device 56
is off, the supply of the electric power to the wireless LAN device
58 is controlled by means of the power management unit 59. In other
words, the power management unit 59 is designed to supply the
wireless LAN device 58 with electric power if the wireless device
58 is in a communication-ready state and the accessory-signal
generating device 56 is switched off. Here, the communication-ready
state is brought about when there exists the radio communication
device 65 (serving as an access point) through which communication
with the wireless LAN device 58 is established.
[0068] Authentication of the wireless LAN device 58 is performed at
the radio communication device 65. To begin the authentication
process, the wireless LAN device 58 searches for the radio
communication device 65 serving as the access point. Then, a
determination is made whether the wireless LAN device 58 is in a
communication-ready state so as to communicate with the radio
communication device 65. If it is determined that the wireless LAN
device 58 is in the communication-ready state, the power management
unit 59 starts to supply the wireless LAN device 58 with electric
power. For example, there is a case where the vehicle is parked at
a location provided with the radio communication device 65 serving
as the access point (e.g., the user's garage 62; a parking lot of
the user's office; a parking lot of a commercial facility, such as
a department store, a supermarket, or a convenience store; a
parking lot of a recreational facility, such as an amusement park
or a game center; a parking lot of a fast-food restaurant or a
coffee shop; a parking lot located around public transportation,
such as a railroad station or an airport; and a gas station). In
such case, the power management unit 59 is allowed to supply the
wireless LAN device 58 with the electric power because the radio
communication device 65 is communicable with the wireless LAN
device 58.
[0069] Furthermore, the power management unit 59 may measure the
volume of communication traffic that flows between the wireless LAN
devices 58 and the radio communication device 65. For example,
where communication is made between one radio communication device
65 and a plurality of the wireless LAN devices 58, the intensity of
the communication traffic between the wireless LAN devices 58 and
the radio communication device 65 increases to such an extent that
the traffic cannot virtually cover high-volume data. The power
management unit 59 is designed to be able to measure the volume of
the communication traffic and determine whether the measured volume
falls within a predetermined volume, i.e., whether the traffic can
cover a predetermined volume of data. Such a determination is made
when the accessory-signal generating device 56 is switched off.
When it is determined that the measured volume falls within the
predetermined volume, the power management unit 59 supplies the
wireless LAN device 58 with the electric power.
[0070] Further, the power management unit 59 may be one of having a
user authentication function. To be authenticated, the user should
be registered with the power management unit 59. Specifically, the
registration is conducted by inputting authentication codes such as
a name, passwords, personal identification numbers, or the like
from the input unit 34. When the accessory-signal generating device
56 is switched off, the display unit 35 shows the user a message to
input the authentication codes. Alternatively, this message can be
delivered to the user by voice from the voice output unit 37. Upon
input of the authentication codes (name, password, personal
identification number, and the like), the power management unit 59
performs the user authentication by checking the inputted
authentication codes against the already-registered authentication
codes. When the user is authenticated and validated as an eligible
user, the power management unit 59 starts to supply the wireless
LAN device 58 with electric power. On the contrary, if the
authentication does not confirm the identity of the user, the unit
59 does not supply the wireless LAN device 58 with electric power.
However, the user authentication is not limited to
previously-described case. The user authentication can be performed
according to a biometric method in which statistical analysis of
biological data about the user is conducted. To use the biometric
method in the user authentication, the biological data about the
user, for example, fingerprints, voiceprints, iris patterns, facial
features, or the like, should be registered with the power
management unit 59 in advance. Upon input of the user's biological
data, an authentication device such as a fingerprint ID system
performs the user authentication by checking the inputted
biological data against already-registered biological data about
the registered user. Thus, the power management unit 59, having the
user authentication function, ensures against unauthorized access
under an assumed name thereby preventing data leakage.
[0071] Upon receipt of the signals from the radio communication
device 65, the wireless LAN device 58 is switched from the
intermittent standby state to the continuous activation state.
Under the continuous activation state, the wireless LAN device 58
can continuously communicate with the radio communication device 65
and transmit the in-communication signals to the startup management
unit 74. The startup management unit 74 receiving the
in-communication signals transmitted along the communication-signal
input line 44a determines that the received in-communication
signals are startup-signals for activating the vehicle navigation
apparatus 15. Upon this determination, the startup management unit
74 starts to transmit the startup-signals along the startup-signal
output line 44b to the storage device 72. In detail, the
startup-signals, similar to the accessory-signals, are direct
current, e.g., a constant voltage of predetermined volts. Such
startup-signals are generated based on the electric power that
flows along the startup-signal output line 44b from the main
electronic power supply 55, and transformed through the startup
management unit 74.
[0072] Because the startup-signals are similar to the
accessory-signals, just as in the case where the device 72 receives
accessory-signals transmitted along the accessory-signal output
line 43b, the storage device 72 can also be activated upon the
receipt of the startup-signals transmitted along the startup-signal
output line 44b. Because of the similarity between the
accessory-signals and the startup-signals, input terminals on the
startup-signal output line 44b to the device 72 and input terminals
on the accessory-signal output line 43b to the device 72 are
practically combined with each other. Therefore, the storage device
72 is activated upon receipt of either the accessory-signals or the
startup-signals on the condition the electric power flows from the
startup management unit 74 along the power input line 42b.
[0073] While the storage device 72 is activated, data sent from the
radio communication device 65 to the wireless LAN device 58 is
transmitted to the storage device 72 through the data line 45 and
stored into the storage device 72. In the first embodiment, it is
desirable that the storage device 72 should work on a standalone
basis, like a DRAM, a flash memory, or a hard disk that has a
special processor workable independent of the working of processor
31.
[0074] However, though less desirable, the storage device 72 may be
a processor-dependent hard disk, i.e., a hard disk controlled by
the processor 31. In this case, the processor 31 serves as a
data-receipt processing device for data received from the wireless
LAN device 58, and therefore the startup management unit 74
supplies the processor 31 with the startup-signals upon receipt of
the startup-signals from the wireless LAN device 58 along the
communication-signal input line 44a.
[0075] Therefore, even if the accessory-signal generating device 56
is switched off while the vehicle is parked in the user's garage
62, it is possible to download the data distributed from the
application server 52 to the vehicle navigation apparatus 15 and to
store such downloaded data into the storage device 72. Furthermore,
according to the invention, only the wireless LAN device 58 is
activated until the download process is started. This leads to the
reduction of power consumption and the prevention of a discharge of
the electric power from the main electronic power supply 55.
[0076] Still further, the wireless LAN device 58 in the
intermittent standby state will facilitate the reduction of power
consumption. Even when the download process is started, the power
consumption will be reduced because only the storage device 72, or
only both the storage device 72 and the processor 31, are
activated. This will also lead to the reduction of power
consumption as well as the prevention of a wasteful discharge of
the electric power from the main electronic power supply 55.
[0077] The flow of electric power to the wireless LAN device 58 in
the intermittent standby state is under the control of the power
management unit 59. Under the control of the power management unit
59, the electric power flows into the wireless LAN device 58 only
when the wireless LAN device 58 is in the communication-ready
state. That is, the power management unit 59 can control the power
consumption of the wireless LAN device 58 to a moderate level. This
will result in the reduction of power consumption of the wireless
LAN device 58.
[0078] Next, the operation of the power management system for a
communication device with previously-described composition will be
detailed with reference to FIG. 4 and FIG. 5, wherein FIG. 4 is a
flowchart showing the operation of a power management system for a
communication device having no user authentication function,
according to the first embodiment of the invention, and FIG. 5 is a
flowchart showing the operation of a power management system for a
communication device having a user authentication function,
according to the first embodiment of the invention. When the
vehicle navigation apparatus 15 is activated as a result of the
accessory-signal generating device 56 being switched on, electric
power flows from the main electronic power supply 55 in order to
activate the wireless LAN device 58.
[0079] Upon detection of the accessory-signal generating device 56
being switched off, the power management unit 59 determines whether
the wireless LAN device 58 is in the communication-ready state.
Specifically, just before the accessory-signal generating device 56
turns off, the power management unit 59 instantaneously determines
whether an access point exists through which communication with the
wireless LAN device 58 is established.
[0080] If it is determined that the wireless LAN device 58 is in
the communication-ready state, the power management unit 59 starts
to supply the wireless LAN device 58 with the electric power. Then,
the wireless LAN device 58 is switched into the intermittent
standby state so as to receive the signals from the radio
communication device 65. On the contrary, if it is determined that
the wireless LAN device 58 is not in the communication-ready state,
the power management unit 59 interrupts the flow of the electric
power to the wireless LAN device 58 and thereby the wireless LAN
device 58 is deactivated.
[0081] The flowchart in FIG. 4 explains the operation of the power
management unit 59 having no user authentication function. In step
1, an accessory-signal generating device 56 is switched off. Then,
in step 2, it is determined whether there exists an access point
through which communication with the wireless LAN device 58 is
established. If the access point exists, operation of the flowchart
continues to step 3. Otherwise, if the access point does not exist,
operation jumps to step 4.
[0082] In step 3, the wireless LAN device 58 is switched to the
intermittent standby state, and operation of the flowchart
terminates. Conversely, in step 4, the flow of electric power to
the wireless LAN device 58 is interrupted and operation of the
flowchart terminates.
[0083] FIG. 5 is a flowchart explaining the operation of a power
management system for the communication device having a user
authentication function, according to the first embodiment of the
invention. Here, for simplicity of explanation, the same operations
described in FIG. 4 are not described. Therefore, only the
operations after the power management unit 59 instantaneously
determines whether there exists the radio communication device 65,
serving as the access point through which communication with the
wireless LAN device 58 is established, are described. When the
power management unit has a user authentication function, if it is
determined that the wireless LAN device 58 is not in the
communication-ready state (communication between the wireless LAN
device 58 and the radio communication device 65 is not
established), the power management unit 59 interrupts the flow of
the electric power to the wireless LAN device 58 and thereby the
wireless LAN device 58 is deactivated. However, if it is determined
that the wireless LAN device 58 is in the communication-ready state
(communication between the wireless LAN device 58 and the radio
communication 65 is established), the display unit 35 shows the
user a message to input the authentication codes, i.e., user's name
and passwords, from the input unit 34.
[0084] Upon the user's input of the authentication codes, the power
management unit 59 performs the user authentication by checking the
inputted authentication codes against the already-registered
authentication codes. If the input codes match the
already-registered codes, the user is authenticated and validated
as an eligible user and the power management unit 59 starts to
supply the wireless LAN device 58 with electric power. Then, the
wireless LAN device 58 is switched into the intermittent standby
state so as to receive the signals from the radio communication
device 65. On the contrary, if the authentication does not confirm
the identity of the user, the power management unit 59 interrupts
the flow of the electric power to the wireless LAN device 58 and
thereby the wireless LAN device 58 is deactivated.
[0085] The flowchart in FIG. 5 explains working of the power
management unit 59 having a user-authentication function. In step
11, an accessory-signal generating device 56 is switched off. Then,
in step 12, an access point is searched for. Next, in step 13, it
is determined whether the wireless LAN device 58 is within
communication coverage of the access point. If the wireless LAN
device 58 is within the communication coverage of the access point,
operation of the flowchart continues to step 14. However, if the
wireless LAN device 58 is not within the communication coverage of
the access point, operation jumps to step 17.
[0086] In step 14, a user's name and a password (authentication
codes) are input. Then, in step 15, it is determined whether the
input user's name and password are valid. If it is determined that
the input user's name and password are valid, operation of the
flowchart continues to step 16. However, if it is determined that
the input user's name and password are invalid, operation jumps to
step 17.
[0087] In step 16, the wireless LAN device 58 is switched to the
intermittent standby state, and the operation of the flowchart
terminates. In step 17, the flow of the electric power to the
wireless LAN device 58 is interrupted, and the operation of the
flowchart terminates.
[0088] According to the first embodiment, when the accessory-signal
generating device 56 is switched off, the power management unit 59
determines whether there exists an access point through which
communication with the wireless LAN device 58, serving as the
communication device, is established. If there is no such access
point, the power management unit 59 interrupts the flow of electric
power to the wireless LAN device 58 and thereby the wireless LAN
device 58 is deactivated. As a result, the wireless LAN device 58
is not activated unnecessarily. This leads to the prevention of a
wasteful discharge of electric power from the main electronic power
supply 55.
[0089] Alternatively, the communication device may be a cellular
terminal rather than the wireless LAN device 58. In this case, the
cellular terminal is intermittently activated in an intermittent
standby state, such that communication with the base station is
made on an intermittent basis. While near the base station, such
intermittent-basis communication is very helpful for continually
determining the position of the cellular terminal, i.e., the
communication device. In detail, the base station regularly checks
where in the communication coverage of the base station the
cellular terminal is located. Usually, the communication coverage
of a base station for a cellular phone has a range of at least 1.5
km to several kilometers. The communication coverage of the base
station for the mobile phones used in PHS (Personal Handy Phone
system) has a range of at least 100 m to several hundreds of
meters.
[0090] FIG. 6 is a flowchart showing the process of startup
management according to the first embodiment of the invention.
Referring to FIG. 6, the description focuses on a process through
which the vehicle navigation apparatus 15 is activated so as to
download data via the operating terminal 14 when the vehicle is
parked at the user's garage 62.
[0091] At the beginning of the process, upon receipt of the
startup-signals to activate the vehicle navigation apparatus 15,
the startup management unit 74 determines whether the
accessory-signal generating device 56 is switched on or off. When
the accessory-signals are not being transmitted to the startup
management unit 74, along the accessory-signal input line 43a, it
is determined that accessory-signal generating device 56 is
switched off. When the accessory-signals are being transmitted to
the startup management unit 74 along the accessory-signal input
line 43, it is determined that device 56 is switched on. If the
accessory-signal generating device 56 is determined to be switched
on, the startup management unit 74 starts the startup management
process.
[0092] If the accessory-signal generating device 56 is determined
to be switched off, the startup management unit 74 then determines
whether in-communication signals are received along the
communication-signal input line 44a from the wireless LAN device
58. If it is determined that the in-communication signals from the
wireless LAN device 58 are received in the startup management unit
74, the startup management unit 74 starts the startup management
process. If it is determined that the in-communication signals from
the wireless LAN device 58 are not received in the startup
management unit 74, the startup management unit 74 abandons the
startup management process.
[0093] In the startup management process (when the
accessory-signals are being transmitted to the startup management
unit 74 along the accessory-signal input line 43a such that the
device 56 is determined to be switched on), the startup management
unit 74 transmits the accessory signals along the accessory-signal
output line 43b to each of the processor 31, the input unit 34, the
display unit 35, the storage device 72, and the other devices 73.
Thereby, every device and unit in the vehicle navigation apparatus
15 is entirely activated.
[0094] When it is determined that the in-communication signals from
the wireless LAN device 58 are received in the startup management
unit 74 and the accessory-signal generating device 56 is determined
to be switched off, the startup management unit 74 transmits the
startup-signals along the startup-signal output line 44b only to
the data-receipt processing device, i.e., only the storage device
72, otherwise, only the storage device 72 and the processor 31.
Thereby, only the data-receipt processing device (the storage
device 72, otherwise, only the storage device 72 and the processor
31) is activated. In this case, any other devices or units except
the data-receipt processing device are not activated. This will
result in the reduction of power consumption as well as the
prevention of the wasteful discharge of the electric power from the
main electronic power supply 55.
[0095] Next, the flowchart in FIG. 6 will be described in detail.
In step 1, startup-signals are transmitted to the startup
management unit 74. Then, in step 2, it is determined whether the
accessory-signal generating device 56 is being switched on. If it
is determined that the accessory-signal generating device 56 is on,
then operation of the flowchart continues to step 4. However, if it
is determined that the accessory-signal generating device 56 is
off, operation jumps to step 3.
[0096] In step 3, it is determined whether the startup management
unit 74 receives the in-communication signals from the wireless LAN
device 58. If it is determined that the in-communication signals
are received in the startup management unit 74, operation of the
flowchart continues to step 4. However, if it is determined that no
in-communication signals are received in the startup management
unit 74, the startup management process is abandoned, and the
operation of the flowchart is terminated.
[0097] In step 4, a startup management process is started. Thus, in
step 5, when the accessory-signal generating device 56 is
determined to be switched on, every device and unit in the vehicle
navigation apparatus 15 is entirely activated. When it is
determined that the accessory-signal generating device 56 is
switched off and in-communication signals from the wireless LAN
device 58 are received in the startup management unit 74, only the
data-receipt processing device is activated.
[0098] According to the first embodiment, the startup management
unit 74 is designed to serve as a gate circuit and perform the
startup management process, thereby controlling the activation of
each device and unit in the vehicle navigation apparatus 15.
Further, the startup management unit 74 is designed to carry out a
voltage transformation process in which the voltage of electric
power sent from the main electronic power supply 55 is transformed
and transmitted to each device and unit. With the voltage
transformation process, the startup-signals, to selectively
activate each device and unit in the vehicle navigation apparatus
15, can be generated. In spite of its simple construction, the
startup management unit 74 alone can selectively startup each
device and unit in the vehicle navigation apparatus 15 without
having to use additional control devices. Moreover, the startup
management unit 74 is designed to activate only the data-receipt
processing device when receiving the in-communication signals from
the wireless LAN device 58. Such selective activation minimizes the
power consumption by the system, reducing a wasteful discharge of
the electric power supplied from a vehicle battery 55.
[0099] Even if the accessory-signal generating device 56 is off
while the vehicle is parked in the user's garage 62, the data
distributed from the application server 52 can be downloaded to the
vehicle navigation apparatus 15 and stored into the storage device
72. In this case, according to the invention, only the wireless LAN
device 58, serving as the communication device, is activated until
the download process is started. This leads to the reduction of
power consumption as well as the prevention of a wasteful discharge
of the electric power from the main electronic power supply 55.
This is in addition to the fact that the wireless LAN device 58 in
the intermittent standby state is already contributing to the
reduction of power consumption.
[0100] Hereinafter, a second embodiment of the invention will be
described. In the interest of the simplicity of explanation, the
same compositions according to the first embodiment are not
described. Furthermore, the reference numerals used in the
description of the first embodiment are given for the same
components described in the second embodiment.
[0101] FIG. 7 illustrates the composition of a power management
system for a communication device according to a second embodiment
of the present invention.
[0102] The power management system for the communication device
according to the second embodiment includes; a wireless LAN device
58, serving as a first communication device, and a specific
low-power radio communication device 57, serving as a second
communication device. The specific low-power radio communication
device 57 is the second communication device that receives certain
signals from a specific low-power radio transmitter, such as a
remote control unit, to unlock doors of the vehicle, to start an
engine of the vehicle, or to set a warning system installed in the
vehicle. Each of the power output line 42b, the accessory-signal
output line 43b, and the startup-signal output line 44b are
connected to the wireless LAN device 58, in order that the wireless
LAN device 58 can receive in-communication signals sent from the
specific low-power radio communication device 57 to the startup
management unit 74 along the communication-signal input line
44a.
[0103] It is desirable that the operating terminal 14 (shown in
FIG. 2) should be connectable to a specific low-power radio
transmitter (not shown), thereby allowing communication with the
vehicle navigation apparatus 15 under a specific low-power radio
communication system. Under the specific low-power radio
communication system, the startup-signals are transmitted, by the
operation of the operating terminal 14, through the specific
low-power radio transmitter to the specific low-power radio
communication device 57 in the vehicle navigation apparatus 15.
This enables the wireless LAN device 58 to communicate with the
radio communication device 65 under the wireless LAN system. Here,
the low-power radio transmitter may be in the form of, for example,
a remote control unit operable on a stand-alone basis.
[0104] When the accessory-signal generating device 56 is switched
on and the vehicle navigation apparatus 15 is activated, the
wireless LAN device 58 is activated based on both the electric
power from a main electronic power supply 55 and the
accessory-signals transmitted accessory-generating device 56.
[0105] Upon detection of the accessory-signal generating device 56
being switched off, the power management unit 59 determines whether
the wireless LAN device 58 is in a communication-ready state. In
detail, just before the accessory-signal generating device 56 turns
off, the power management unit 59 instantaneously determines
whether there exists the access point through which communication
with the wireless LAN device 58 is established. Here, under the
wireless LAN system, as far as being activated, the wireless LAN
card is designed to search for the access point through which
communication can be established.
[0106] If it is determined that the wireless LAN device 58 is in a
communication-ready state, the power management unit 59 starts to
supply the specific low-power radio communication device 57 with
electric power. Then, the specific low-power radio communication
device 57 is switched into the intermittent standby state so as to
receive the signals from the radio communication device 65. On the
contrary, if it is determined that the wireless LAN device 58 is
not in a communication-ready state, the power management unit 59
interrupts the flow of the electric power to the specific low-power
radio communication device 57 and thereby the specific low-power
radio communication device 57 is deactivated.
[0107] Upon receipt of the in-communication signals transmitted by
the users operation of the specific low-power radio transmitter
(i.e., the remote control unit), the specific low-power radio
communication device 57 in the intermittent standby state is
switched to the activation state. Being activated, the specific
low-power radio communication device 57 transmits the
in-communication signals along the accessory-signal input line 44a
to the startup management unit 74. Upon receipt of the
in-communication signals, the startup management unit 74 starts to
transfer the startup-signals along the startup-signal output line
44b to both the storage device 72 and the wireless LAN device 58.
In transferring the startup-signals, the startup management unit 74
carries out a voltage transformation process in which voltage of
the electric power sent along the power input line 42a from the
main electronic power supply 55 is transformed to direct current,
and thereby generates the startup-signals similar to the
accessory-signals. That is, the startup-signals are direct current,
i.e., a constant voltage of predetermined volts.
[0108] Because the startup-signals are similar to the
accessory-signals, both the storage device 72 and the wireless LAN
device 58 can be activated upon receipt of the startup-signals
transmitted along the startup-signal output line 44b just as in the
case where they receive the accessory-signals transmitted along the
accessory-signal output line 43b. Because of the similarity between
the accessory-signals and the startup-signals, input terminals on
the startup-signal output line 44b to both the storage device 72
and the wireless LAN device 58 are practically combined with input
terminals on the accessory-signal output line 43b to both of the
storage device 72 and the wireless LAN device 58. In summary, the
storage device 72 and the wireless LAN device 58 are activated upon
receipt of either the accessory-signals or the startup-signals when
electric power flows from the startup management unit 74 along the
power output line 42b.
[0109] When the storage device 72 and the wireless LAN device 58
are activated, the data sent from the radio communication device 65
to the wireless LAN device 58 is transmitted to the storage device
72 along the data line 45 under the wireless LAN system and thereby
the data is stored into the storage device 72.
[0110] In the interest of the simplicity of explanation, further
operations other than those already described according to the
second embodiment will not be described hereinafter. Further
operations according to the second embodiment are the same as those
according to the first embodiment.
[0111] According to the second embodiment, the power management
unit 59 determines whether there exists an access point through
which communication with the wireless LAN device 58 is established
when the accessory-signal generating device 56 is switched-off. If
there exists no such access point, the power management unit 59
interrupts the flow of electric power to the specific low-power
radio communication device 57 and thereby the specific low-power
radio communication device 57 is deactivated. In other words, the
specific low-power radio communication device 57 is not activated
unnecessarily. This will lead to the prevention of wasteful
discharge of the electric power from the main electronic power
supply 55.
[0112] The foregoing invention has been described in terms of
preferred embodiments. However, those skilled in the art will
recognize that many variations of such embodiments exist. Such
variations are intended to be within the scope of the present
invention and the appended claims.
[0113] Furthermore, it should be appreciated that each example or
list contained in the detailed description of preferred embodiments
is non-exclusive and is intended to encompass any now known or
later developed members of the class represented by that example or
list.
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