JPH01259615A - Channel presetting system - Google Patents

Abstract

PURPOSE:To always receive broadcasting of good sensitivity based on a preset channel by providing a roadside transmitter and transmitting a wave to display the frequency of a broadcasting wave of high electric field intensity in the moving direction of a moving body. CONSTITUTION:A roadside transmitter 1 to transmit the wave to show a signal to display the broadcasting frequency of comparatively high electric field intensity in the direction of the moving body is set up on a roadside. When a moving body 3 comes near the roadside transmitter 1, a channel setter 7 loaded in the moving body receives and demodulates the wave, identifies the frequency of the broadcasting wave and presets it automatically. In this case, the broadcasting wave of high electric field intensity broadcasted in the area is preset, therefore, as moving by the moving body, the broadcasting of good sensitivity in the traveling direction can be always viewed based on the preset frequency.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a channel preset system, and more specifically, to radio receivers and televisions mounted on vehicles, aircraft, ships, etc. (hereinafter referred to as "mobile objects"). The present invention relates to a channel presetting method that automatically presets the tuning frequency of a tuner of a broadcast receiver such as a receiver to match the broadcast frequency of an area where a mobile object moves.

<Conventional technology> When a car is driving and receives broadcast radio waves using a broadcast receiver installed in the car, the sensitivity gradually decreases as the car moves away from the broadcast station, resulting in a worsening of the S/N ratio. A phenomenon occurs. If you move further away, you will no longer be able to hear the broadcast content at all, and only noise will be heard. In such cases, the crew member presses the channel button on the broadcast receiver and changes the tuner channel to tune to the broadcast station that can be listened to with good sensitivity.

<Problem to be solved by the invention> However, the preset channels are usually selected from the channels of broadcasting stations whose service area is the area where the car is daily driving. (As you drive, the number of broadcast waves that you can hear with good sensitivity will continue to decrease even if you change various channels.) When driving for a long distance, etc., the number of broadcast waves that can be heard with good sensitivity will continue to decrease. Even if all the broadcasts are combined, a situation may arise in which the broadcast cannot be received at all.

In this case, the driver has to redo the channel preset or turn the tuning dial by hand to tune the vehicle, which is cumbersome and prevents the driver from concentrating on driving.

This invention was made in view of the above-mentioned problems, and the crew member does not have to redo channel presets or turn the tuning dial by hand to tune in, and the crew can always listen to broadcasts in the moving area with good sensitivity. The purpose of the present invention is to provide a channel preset method that can be used to receive radio waves.

Means for Solving the Problems> The channel presetting method of the present invention to achieve the above object uses a roadside transmitter that transmits radio waves that display broadcasting frequencies with relatively high electric field strength in the direction in which a mobile object is moving. In addition to being installed on the roadside, the mobile object is equipped with a channel setting device that receives and demodulates the radio waves, identifies the broadcast frequency, and automatically presets the tuning frequency of the tuner of the broadcast receiver mounted on the mobile object. This is what I did.

Function> The roadside transmitter transmits radio waves that display a broadcast wave frequency selected from broadcast wave frequencies with relatively high electric field strength in the direction in which the moving object is moving as seen from the point where the roadside transmitter is installed. When the mobile unit comes near the roadside transmitter, the channel setting device installed on the mobile unit will
It receives and demodulates the radio wave, identifies the frequency of the broadcast wave, and automatically presets it.

Therefore, the broadcast radio waves with high electric field strength broadcast in that area will be preset, so the crew members can
While moving with a mobile object, it is possible to always watch broadcasts with good sensitivity in the direction of travel based on the preset frequency without performing manual presetting or the like.

<Example> Next, an example of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram showing a channel presetting method. (6) is an expressway or major arterial road, and roadside antennas (5) are erected at the boundaries of the two broadcasting station service areas (A) and (B). machine (1) is connected.

The car (3) has an on-board antenna (4) that receives broadcast waves and radio waves emitted from the roadside antenna (5), and an on-board receiver that receives the radio waves incident on the on-board antenna (4).
is installed.

FIG. 2 is a block diagram showing the internal configuration of the roadside transmitter (1), in which the code signal generator (13 ), a transmitter (12) that generates a radio frequency signal, and a modulator (11) that modulates the radio frequency signal with the code signal. Therefore, the roadside transmitter (1) can always transmit radio waves containing a code signal that displays a broadcast frequency with a relatively high electric field strength in the direction of travel.

FIG. 3 shows an example of the code structure of the code signal. The code consists of a start bit (ST), an information bit (I), and a stop bit (SP). The start bit (ST) and stop bit (SP) are bits for synchronizing signals and indicating the beginning and end of information, respectively. Information bit (1) is a broadcast frequency (f'1.f2.f) with relatively high electric field strength in the direction of travel.
3-) and the broadcast frequency (rl.

f'2, f3...) and channel numbers (Chl, 2.3...) for identifying them.

FIG. 4 is a block diagram showing the internal configuration of the in-vehicle receiver (2), and the in-vehicle receiver (2) has a channel setting device (
It consists of a power source and a television/radio receiver (8). The channel setting device (7) is a roadside antenna (5)
a decoder (71) that decodes radio waves emitted from a tuner (71), and a decoder (71) that decodes radio waves emitted from
1) Channel settings that generate a signal that gives a reverse voltage value if (82) uses a varactor diode method for tuning, or a signal that gives a frequency division ratio if it uses a synthesizer method for tuning. (72). The channel setting section (72) includes a microcomputer (73) and a channel number (ChL, 2.3).
-') and frequency (H, f'2.1'3-) in its own preset table, a tuning operation unit (75) for specifying a channel, and a ROM (74) that stores any frequency (H, f'2.1'3-) f'l, f2, f3, . .

The television/radio receiver (8) also includes a television tuner section (81), a radio tuner section (82), a television demodulation section (83), a radio demodulation section (84), and a television output section (85).
), and a radio output section (86). In addition, (41) is a branching filter, and in-vehicle antenna (4)
It separates the radio waves emitted from the roadside antenna (5) and the broadcast radio waves included in the radio waves incident on the roadside antenna (5).

According to the configuration shown in FIG. 4, the radio waves emitted from the roadside antenna (5) are demultiplexed by the demultiplexer 41) and enter the decoder (71) in the channel setting device (7). The decoding section (71) decodes this radio wave and outputs the channel information included in the radio wave in the form of a baseband signal to the channel setting section (72). Channel setting section (72)
reads the channel information included in the baseband signal and receives the read channel number (Chl, 2.
3.) and frequency (N, f2.r3-) in ROM (74
) in the preset table. At the same time, the microcomputer (73) outputs from the output section (76) a tuning signal corresponding to the frequency of the channel specified by the operation of the tuning operation section (75).

On the other hand, the broadcast radio waves directly enter the tuner sections (81) (82) of the TV/radio receiver (8) from the splitter (41), and are tuned in the tuner sections (81) (82).
The tuned signals are demodulated by each demodulation section (83) (84), and are input to a CRT or speaker as an image signal and an audio signal through each output section (85) (86).

Next, while referring to the flowchart (see Figure 5),
The function of the channel setting section (72) will be explained.

The channel setting section (72) constantly monitors the baseband signal input from the decoding section (71) (step ■), and when channel information comes in (step ■
), the channel number (Chl, 2.3...) and the broadcast frequency (['l, 1'2...) are identified (step ■). Meanwhile, check the channel number currently in use,
Channel number identified above (Chi, 2.3...)
It is determined whether there is a channel number in use in (Step ■). If there is, the process moves to step (2), and the currently used frequency (not necessarily f'L) is applied to the currently used channel (for example, chl) (step (2)). If not, the identified channel number (Chl, 2.3...) and broadcast frequency (fL
, f2. ...) is sent as is to the ROM (74).

In this way, the ROM (74) stores the channel number (Ch) sent from the microcomputer (73).
1, 2.3-) and the broadcast frequency (rl, f2. . .) in its own preset table, the contents of the preset table are updated. In this case, as in step (2) above, the frequency currently in use is preset as is for the channel currently in use.

Therefore, even if the occupant passes by the roadside transmitter, he or she does not realize that he or she has passed by the roadside transmitter, and while watching the content of the broadcast that he or she is currently watching, he or she may compare the contents of the channel preset and the electric field strength in the direction in which the moving object is moving. can automatically change to a higher broadcast frequency. Therefore, broadcasts in the current driving area can always be viewed with good sensitivity. Furthermore, the user will not feel uncomfortable if the broadcast he or she is currently viewing is suddenly switched to another broadcast.

Note that the broadcast that is currently being played will no longer be audible as the car continues to drive, so the occupants should switch to another channel. Therefore, by installing a roadside transmitter at another location and resetting the preset when the vehicle passes by, it is possible to switch the preset contents for all channels without giving the occupants an unnatural feeling.

In this way, even if the antenna power and installation location of each broadcasting station is different, and the service area is different, by installing roadside transmitting devices in various locations, it will not give an unnatural feeling to the passengers. You can easily switch all broadcast frequencies.

Note that this invention is not limited to the above embodiments. In the above embodiment, the identified channel number (Ch
i, 2.3...), if there is a channel number currently in use, the preset is not updated for that channel and you can continue to listen to the frequency currently in use. Presets may be updated all at once. Moreover, it goes without saying that this invention can be applied not only to automobiles but also to ships and aircraft. Various other design changes can be made without changing the gist of the invention.

<Effects of the Invention> As described above, according to the channel presetting method of the present invention, the roadside transmitter transmits radio waves that display the frequency of broadcast waves with relatively high field strength in the direction in which the mobile object is moving. Therefore, when a car equipped with the above-mentioned in-vehicle TV/radio receiver passes by the roadside transmitting device, the channel setting device receives and demodulates the above-mentioned radio waves, and can automatically preset a frequency with good sensitivity. therefore,
While moving in a mobile vehicle, occupants can always receive broadcasts with good sensitivity in the area they are driving based on the preset channel, without having to manually re-preset the channel or operate the tuning dial as in the past. It has the unique effect of being able to receive

[Brief explanation of the drawing]

Figure 1 is a schematic diagram showing the channel preset method, Figure 2 is a block diagram showing the internal configuration of the roadside transmitter, and Figure 3 is an example of the code structure of the code signal included in the radio waves transmitted from the roadside transmitter. 4 is a block diagram showing the internal configuration of the on-vehicle receiver, and FIG. 5 is a flowchart showing the channel presetting procedure. (1)...roadside transmitter, (3)...car, (5)
...Roadside antenna, (7)...Channel setting device, (8)...Broadcast receiver, (81), (82)...
Tuner, (Chi~4)...Channel number, (('1~4)
...Broadcast frequency patent applicant Sumitomo Electric Industries, Ltd. Figure 5

Claims (1)

[Claims] 1. Electric field strength in the direction of movement of the moving object A signal that displays a relatively high broadcast frequency. The roadside transmitter that transmits the radio waves representing In addition to receiving the above radio waves, demodulates, identifies the above broadcast frequency, and transfers it. The tuner of a broadcast receiver mounted on a moving object A channel that automatically presets the tuning frequency. Installing a channel setting device on a mobile object Channel preset method featuring formula. 2. Roadside as described in Claim 1 above Transmitting device. 3. The feature set forth in claim 1 above. channel setting device.