JP3679676B2 - Navigation device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a navigation apparatus for displaying VICS information transmitted from an FM multiplex broadcasting station.
[0002]
[Prior art]
On April 23, 1996, a VICS (Vehicle Information and Communication System) service for transmitting traffic jam information to a navigation device was started. This service provides three levels of information: level 1 (character display), level 2 (simple graphic display), and level 3 (map display). This service information is performed by three communication means of FM multiplex broadcasting, radio wave beacon and optical beacon.
[0003]
There are 15 FM multiplex broadcasting stations as of December 21, 1999. Since there are a plurality of FM multiplex broadcasting stations, the navigation device displays the name of the currently receiving broadcasting station and the reception frequency. The broadcast station to receive changes as the vehicle moves. Normally, when the electric field strength of the currently receiving broadcast station falls below a predetermined value, another broadcast station is automatically searched for and switched to the broadcast station with the strongest electric field strength above a predetermined level.
[0004]
Conventionally, based on the current frequency of the FM tuner, the frequency of the currently receiving broadcast station is displayed. For this reason, the numbers change at high speed during the search, and characters or symbols indicating that the search is in progress are displayed.
[0005]
[Problems to be solved by the invention]
However, since the VICS information before the search is displayed during the search, the frequency of the currently displayed VICS information cannot be notified to the user.
[0006]
[Means for Solving the Problems]
The navigation device of the present invention has been made in view of such points, and when displaying the reception frequency, when displaying the level 1 or level 2 VICS information, display the frequency when the displayed VICS information is received, When displaying level 3 VICS information, a frequency display means for displaying the current frequency of the FM tuner is provided.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the present invention will be described with reference to the drawings. The navigation apparatus of the present embodiment receives FM multiplex broadcasting and displays VICS information.
[0009]
As described above, VICS is a service that transmits traffic jam information to a navigation device. This service has three levels of information, level 1 (character display, see FIG. 6), level 2 (simple graphic display, see FIG. 7), and level 3 (map display, see FIGS. 8 and 10), depending on usage fees. Is provided. At level 1, character data to be displayed is transmitted. In level 2, simple graphic data to be displayed is transmitted. At level 3, the map data itself is not transmitted, and the map database provided in the navigation device is used. The main roads are classified and numbered in advance, and the traffic congestion status is transmitted for each segment. It is left to the navigation device how to display this traffic jam information on the map.
[0010]
This service information is performed by three communication means of FM multiplex broadcasting, radio wave beacon and optical beacon. Either communication means provides the above three levels of information. FM multiplex broadcasting is broadcast from NHK (Japan Broadcasting Corporation) facilities borrowed by the VISC center, radio beacons are installed on highways led by the Ministry of Construction, and optical beacons are led by the National Police Agency in general except for highways. Installed on the road. An FM receiver is required to display VICS information in FM multiplex broadcasting, a radio beacon receiver is required to display VICS information in radio beacons, and an optical beacon to display VICS information in optical beacons. A receiver is required. The present embodiment displays VICS information by FM multiplex broadcasting, and has an FM receiver.
[0011]
FIG. 1 is a block diagram showing the configuration of the main part of the first embodiment. This device comprises an FM receiver (FM tuner) (1) and a current position indicator (2).
[0012]
In the FM receiver (1), the FM front end (11) amplifies the signal received from the antenna (12) to form a high frequency signal, and mixes this high frequency signal with the oscillation signal from the PLL circuit (13). Output an intermediate frequency signal. The FM-IF detector (14) performs FM detection on the intermediate frequency signal output from the FM front end (11).
[0013]
(15) is a multiplex signal detection circuit, which comprises a multiplex filter (not shown) and a data demodulation circuit (not shown). The multiplexing filter removes an audio signal and a noise component from the output signal of the FM-IF detector (14), and extracts an LMSK (Level controlled Minimum Shift Keying) signal multiplexed at 76 kHz. LMSK is a modulation method for controlling the size of a multiplexed signal in accordance with the size of a stereo audio signal. The data demodulation circuit demodulates the LMSK signal into a displayable data signal and sends it to the control circuit (16) of the FM receiver (1). The control circuit (16) of the FM receiver (1) instructs the frequency to be set in the PLL circuit (13).
[0014]
In the current position indicator (2), (21) is a control circuit, which performs display based on a program written in the ROM (22). Reference numeral (23) denotes a RAM which stores information necessary for the operation of the control circuit (21), for example, the update time of the displayed VICS information and the frequency of the FM multiplex broadcast station. (24) is a GPS (Global Positioning System) positioning means that receives radio waves from GPS satellites, measures the current position, and outputs the measurement data to the control circuit (21) of the current position indicator (2). (25) is a map reproducing means, which reads the map information from the DVD in which the map information is written and outputs it to the control circuit (21). Reference numeral (26) denotes a liquid crystal display unit which displays a map, a current position, and VICS information based on the control of the control circuit (21). (27) is an input unit for performing various inputs related to the current position display and VICS.
[0015]
The operation of the first embodiment will be described. FIG. 2 is a flowchart showing the operation of the control circuit (21) of the current position indicator (2).
[0016]
When the vehicle is running outside the area of the FM multiplex broadcasting station and when the user intentionally sets the VICS function to OFF, the FM frequency display is not performed. In such a case (N of S1), when a map display is instructed from the input means, the control circuit (21) of the current position indicator (2) is output from the GPS positioning means of the scale specified by the input means. The map including the current position is retrieved from the map reproducing means (25) and output to the display unit (26). Then, the current position is displayed on the displayed map. At this time, the control circuit (21) does not perform FM frequency display.
[0017]
When the vehicle is traveling in the area of the FM multiplex broadcasting station and the user has set the VICS function to ON, the FM frequency is displayed. In this case (Y in S1), when the frequency setting screen is instructed by the input means, the frequency setting screen is displayed without displaying the VICS information (N in S2). On this screen, it is necessary to display the current reception frequency so that the user can manually designate the desired FM broadcast station. Therefore, on this screen, the frequency indicated by the control circuit (16) of the FM receiver (1) to the PLL circuit (13) is output to the control circuit (21) of the current position indicator (2) (S3). . Then, the control circuit (21) of the current position indicator (2) causes the display unit (26) to display a frequency based on this frequency. For example, when the frequency setting screen is displayed, as shown in FIGS. 3 and 5, the current frequency is displayed unless searching is being performed. As shown in FIG. 4, when searching manually or when moving to another broadcast station area automatically as the vehicle moves, the current frequency is not displayed but the text “searching” is displayed.
[0018]
While searching, the user cannot read the frequency, but at this time there is no problem because the VICS information is not displayed. During the search, the specified frequency may be displayed on the PLL circuit (13). However, since the displayed number changes quickly, it is difficult for the user to read.
[0019]
When the mode for displaying the VICS information is instructed from the input means (Y in S2), the control circuit (21) of the current position indicator (2) stores the frequency when the currently displayed VICS information is received in the RAM. Read from (23) and display the frequency on the display unit (26) based on this frequency (S4). At this time, the frequency is displayed regardless of the search. For example, at levels 1 and 2, the control circuit (21) of the current position indicator (2) displays the received VICS information on the entire screen as shown in FIGS. However, the frequency is displayed based on the frequency when the VICS information is received. At level 3, as shown in FIG. 8, first, a map and the current position are displayed, and a congested road is displayed in a conspicuous color based on the traffic information of the main road received from the broadcast station. Even during the search, the frequency is displayed based on the frequency when the VICS information is received.
[0020]
As a result, even when the reception frequency is changed because the search is in progress, the user can check the frequency of the reception information (VICS information) broadcasted by FM multiplex broadcasting.
[0021]
Next, a second embodiment will be described. The block diagram of the second embodiment is the same as the block diagram of the first embodiment (FIG. 1). FIG. 9 is a flowchart showing the operation of the main part of the control circuit (21) of the current position indicator (2) of the second embodiment, which differs from the flowchart of the first embodiment only in step 12. The description of the same operation as that of the first embodiment is omitted.
[0022]
In FIG. 9, when the vehicle is traveling in the area of the FM multiplex broadcasting station (Y in S1), if the input means instructs to display neither VICS information level 1 nor level 2 (N in S12). ) That is, in addition to the first embodiment, even if it is level 3, the current position indication of the frequency that the control circuit (16) of the FM receiver (1) is currently instructing to the PLL circuit (13) It outputs to the control circuit (21) of the machine (2) (S3). Then, the control circuit (21) of the current position indicator (2) causes the display unit (26) to display a frequency based on this frequency.
[0023]
When the display of level 1 or level 2 of the VICS information is instructed from the input means (Y of S12), the control circuit (21) of the current position indicator (2) displays the current display as in the first embodiment. The frequency when the received VICS information is received is read from the RAM (23), and the display unit (26) displays the frequency based on this frequency (S4).
[0024]
Thus, in the second embodiment, at level 3 for displaying the current position travel, unlike levels 1 and 2, display based on the current frequency of the FM receiver (1) is performed. Unlike levels 1 and 2 in which the entire screen performs display related to VICS, the current position is displayed at level 3. For this reason, at level 3, the currently received frequency is also displayed, and the information unified at the present time can be notified to the user. FIG. 10 shows an example of display during level 3 search. The frequency display becomes “----”, indicating that the search is being performed.
[0025]
In the first embodiment, the user cannot be notified that the search is being performed, but a search notification means may be provided. For example, as shown in FIG. 11, the user may be notified that the search is being performed by blinking the frequency.
[0026]
【The invention's effect】
Even when the reception frequency is changed because the search is in progress, the user can check the frequency of the displayed reception information (VICS information). Since the current position is displayed at level 3, the currently received frequency can also be displayed and the user can be notified of the information that is currently unified.
[0027]
Further, when emphasizing the notification of VICS information, the frequency that matches the displayed VICS information is displayed, and when emphasizing the notification of the current reception frequency, the frequency of the current FM tuner is displayed. The corresponding frequency can be displayed.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a main configuration of a first embodiment of the present invention.
FIG. 2 is a flowchart showing main operations of the first embodiment.
FIG. 3 is a diagram illustrating a frequency setting screen (before search) according to the first embodiment.
FIG. 4 is a diagram illustrating a frequency setting screen (during search) according to the first embodiment.
FIG. 5 is a diagram illustrating a frequency setting screen (after search) according to the first embodiment;
FIG. 6 is a diagram showing a VICS level 1 screen (during search) in the first embodiment;
FIG. 7 is a diagram showing a VICS level 2 screen (during search) in the first embodiment;
FIG. 8 is a diagram showing a VICS level 3 screen (during search) in the first embodiment;
FIG. 9 is a flowchart showing main operations of the second embodiment.
FIG. 10 is a diagram showing a VICS level 3 screen (during search) in the second embodiment;
FIG. 11 is a diagram showing a VICS level 3 screen (during search) according to another embodiment;
[Explanation of symbols]
1 FM receiver 13 PLL circuit 15 Multiplex signal detection circuit 16 Control circuit (FM receiver)
2 Current position detector 21 Control circuit (current position detector)
23 RAM
24 GPS positioning means 25 Map reproduction means 26 Display part 27 Input part

Claims (1)

In a navigation apparatus for receiving and displaying VICS information of level 1 (character display), level 2 (simple graphic display), and level 3 (map display) transmitted from an FM multiplex broadcasting station by an FM tuner.
When the reception frequency is displayed, when the level 1 or level 2 VICS information is displayed, the frequency when the displayed VICS information is received is displayed. When the level 3 VICS information is displayed, the FM tuner is displayed. A navigation apparatus comprising frequency display means for displaying the current frequency.

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