JPH06252815A - In-vehicle video image re-transmission device - Google Patents

Abstract

PURPOSE:To watch a TV broadcast by selecting a preferred channel in a moving vehicle and to receive an excellent picture without being affected of interference of a regular TV broadcast wave. CONSTITUTION:A regular TV broadcast wave is received by a reception antenna 2 installed at the outside of a vehicle and inputted to a head end device 3. The head end device 3 distributes the received signal by a distributor 31 and uses converters 32-34 to convert a frequency channel individually. The converters 32-34 convert the received signal into a signal of a frequency channel different from a TV broadcast wave such as an intermediate mid-band frequency between a 3rd channel and a 4th channel. The signals converted by the converters 32-34 are synthesized by a synthesizer 35 and amplified by an amplifier 36 and outputted into a vehicle as a re-transmission wave 41 through a leakage coaxial cable 4. Thus, passengers in the vehicle select a retransmission wave 41 by a TV set 5 freely and watch the broadcast.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-vehicle image retransmitting device for receiving TV radio waves normally broadcast in a train or the like and retransmitting them in the car.

[0002]

2. Description of the Related Art A conventional retransmitting device provides a radio broadcasting service to an automobile passing in a tunnel or the like, but retransmits an ordinary TV (television) broadcast wave, particularly a train. Has not been retransmitted to mobiles such as.

[0003]

When retransmitting a radio broadcast in the tunnel or the like, the broadcast wave and the retransmitted frequency are transmitted at the same frequency. However, in a re-transmission facility inside a moving body such as a train, there is a problem in re-transmission with the same frequency due to a dive signal from the outside of the car. In particular, when retransmitting TV broadcast waves, mutual interference due to a dive signal of TV broadcast waves becomes a particularly serious problem.

Recently, equipment for receiving a video signal such as a satellite broadcast on the vehicle and broadcasting the signal inside the vehicle has been put into practical use. However, broadcasting is performed by connecting a fixed monitor TV or the like in the vehicle by wire. However, the system does not allow passengers to freely select and listen to broadcast waves. As described above, it is difficult for the conventional retransmission equipment to retransmit the TV broadcast wave.

The present invention has been made in consideration of the above circumstances, and allows passengers to arbitrarily select and watch a desired TV channel in a moving vehicle, and is free from the interference of the original TV broadcast wave. It is an object of the present invention to provide an in-vehicle image retransmitting device that can receive excellent images.

Further, according to the present invention, in-vehicle image re-transmission capable of re-transmitting good TV radio waves into the vehicle even in a place where the vehicle cannot directly receive the TV broadcast waves, for example, in a section where the TV broadcast waves do not reach such as in a tunnel The purpose is to provide a device.

[0007]

SUMMARY OF THE INVENTION The present invention provides an in-vehicle image retransmitting device for receiving a TV broadcast wave in a train or the like and retransmitting it in a car, and an antenna provided outside the car for receiving the TV broadcast wave. The signal received by this antenna is T
It is provided with one or a plurality of converters for converting to a frequency different from the V broadcast wave, an amplifier for multiplexing and amplifying the output of this converter, and a transmitting means for transmitting the output of this amplifier into the vehicle. And

Further, according to the present invention, in the in-vehicle image retransmitting apparatus, an antenna installed outside a tunnel for receiving a TV broadcast wave, and a signal received by this antenna are transmitted to a TV.
It is characterized by comprising an amplifier for amplifying at the same frequency as the broadcast wave, and a transmitting means for transmitting the output of this amplifier to a vehicle passing through the tunnel.

[0009]

[Operation] Normal TV by receiving antenna installed outside the vehicle
Receives broadcast waves and inputs them to the headend device. In this headend device, a distributor distributes a received signal, and a converter individually converts frequency channels. In this converter, the received signal is a frequency channel different from the TV broadcast wave, for example, an intermediate midpoint between the TV channel 3 (102 to 108 MHz) and the channel 4 (170 to 176 MHz), which is not used for normal TV broadcasting. Convert to band frequency. The signal converted by this converter is combined and amplified, and then output as a retransmitted wave in the vehicle through, for example, a leaky coaxial cable installed in the vehicle. Therefore, passengers in the car can retransmit the TV
It is possible to freely select and watch the set.

Further, in a place such as a tunnel where the TV broadcast wave does not reach, a receiving antenna is installed at a place where the TV broadcast wave can be received, and the TV broadcast wave received by this receiving antenna is amplified and, for example, by a leaky coaxial cable. Retransmit into the tunnel. The retransmitted wave at this time uses the same frequency channel as the TV broadcast wave. As a result, it becomes possible to satisfactorily watch TV even in a section where the TV broadcast wave does not reach, such as in a tunnel.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an in-vehicle image retransmitting apparatus according to an embodiment of the present invention. In this in-vehicle image retransmitting device, a receiving antenna 2 is installed outside the vehicle 1, for example, on a roof, and a normal TV broadcast wave 2 is generated by this antenna 2.
Receive 1 In addition, tunnel 1 where TV broadcast wave does not reach
In a place such as 0, the receiving antenna 6 is installed in a place where the TV broadcast wave 21 can be received, and the TV broadcast wave 21 received by the receiving antenna 6 is amplified by the amplifier 61 in the tunnel 10.
It is amplified by and is retransmitted into the tunnel 10 by the leaky coaxial cable 62. At this time, the retransmitted wave 22 from the leaky coaxial cable 62 is retransmitted on the same frequency channel as the TV broadcast wave.

In the tunnel 10, the receiving antenna 2 installed in the vehicle 1 receives the retransmitted wave 22 instead of the TV broadcast wave 21. The signal received by the receiving antenna 2 is sent to the headend device 3. In this headend device 3, first, a converter 3 that distributes a received signal by a distributor 31 and individually converts frequency channels
Input to 2, 33, 34.

In each converter 32, 33, 34,
The received signal is a frequency channel different from the TV broadcast wave 21 and the retransmitted wave 22 in the tunnel 10, for example, the third TV channel (1) which is not used for normal TV broadcasting.
02-108MHz) and 4th channel (170-17)
6 MHz) to convert to an intermediate mid-band frequency.

The signals converted by the converters 32, 33 and 34 are combined by the multiplexer 35 and input to the amplifier 36. Then, the output of the amplifier 36 is transmitted to the inside of the vehicle through the leaky coaxial cable 4 installed in the vehicle, and the retransmitted wave 41 is transmitted.
Sent as. Therefore, passengers in the vehicle can
1 can be freely selected and viewed on the TV set 5.

Further, the output of the multiplexer 35 is the amplifier 3
7 is transmitted to the adjacent vehicle 11 via the coaxial cable 71 and the coupler 72 that connects the connecting portion of the vehicle, is retransmitted into the vehicle by the leaky coaxial cable 74 which is amplified by the amplifier 73 and is installed in the vehicle. Send as wave 42. This allows passengers in the vehicle to freely select and watch the retransmitted wave 42 on the TV set 5.

In addition, since some general TV sets cannot be tuned in the entire midband band, the tunable range is widened so that the TV set 5 can receive the midband band. You need to use one.

FIG. 2 shows an example of allocation of frequencies used for each signal transmission, and shows the first channel, the third channel, and the fourth channel as targets of frequency conversion. There are mid-band channels M1 to M10 between the third channel (102 to 108 MHz) and the fourth channel (170 to 176 MHz), and in this embodiment, the channels M2 (114 to 120 MHz) and the channel M4.
(126 to 132 MHz), channel M6 (138 to
144 MHz) is used to convert the first channel to channel M2, the third channel to channel M4, and the fourth channel to channel M6.

By the above conversion, the retransmitted waves 41,
42 is a frequency channel different from the TV broadcast wave 21, and even if the TV broadcast wave 21 jumps directly into the vehicle, the passenger receives the retransmitted wave of another frequency channel on the TV set 5, so that the interference occurs. There is no adverse effect.

In the above embodiment, the signal to be retransmitted has three channels (three converters), but the present invention is not limited to this, and converters are installed according to the number of channels of broadcast waves. Therefore, the number of channels to be retransmitted can be freely set.

Further, in the present invention, a leaky coaxial cable is used both in the tunnel and in the vehicle for re-transmission.
The present invention is not limited to this, and a transmission antenna may be used.

[0022]

As described in detail above, according to the present invention, the signal received by the antenna provided outside the vehicle is retransmitted into the vehicle through the frequency channel different from the TV broadcast wave.
In the moving car of passengers, a desired channel can be arbitrarily selected to watch TV, and a received signal can receive a good image without being interfered with an original TV broadcast wave.

Further, in a non-arrival section of TV broadcast waves such as in a tunnel, a signal received at a receivable point is retransmitted into the tunnel in advance, so that the TV can be viewed well even in the tunnel. You can

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an in-vehicle image retransmission device according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of frequency arrangement in the embodiment.

[Explanation of symbols]

1, 11 ... Vehicle, 2, 6 ... Receiving antenna, 3 ... Headend device, 4 ... Leakage coaxial cable, 5 ... TV set, 1
0 ... tunnel, 21 ... TV broadcast wave, 22 ... retransmission wave, 3
1 ... Distributor, 32, 33, 34 ... Converter, 35 ... Combiner, 36, 37 ... Amplifier, 41, 42 ... Retransmitted wave, 6
1, 73 ... Amplifier, 62 ... Leaky coaxial cable, 71 ... Coaxial cable, 72 ... Coupler, 74 ... Leaky coaxial cable.

Claims (2)

[Claims] 1. A train or the like receives TV broadcast waves,
In an in-vehicle image retransmitting device for retransmitting in a vehicle, an antenna provided outside the vehicle for receiving a TV broadcast wave, and one or a plurality of converters for converting a signal received by this antenna into a frequency different from the TV broadcast wave An in-vehicle image retransmitting device comprising: an amplifier that multiplexes and amplifies the output from the converter, and a transmitting unit that transmits the output of the amplifier into the vehicle. 2. The in-vehicle image retransmitting device according to claim 1, wherein the antenna is installed outside the tunnel and receives a TV broadcast wave, and an amplifier that amplifies a signal received by this antenna at the same frequency as the TV broadcast wave. And an in-vehicle image retransmitting device comprising: an output of the amplifier; and a transmitting means for transmitting the output of the amplifier to a vehicle passing through a tunnel.