JPS6139778B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical information transmission system for vehicles moving on routes, which uses light to transmit information to vehicles moving on routes.

Radio waves are used as a medium for transmitting information to vehicles moving on routes. Radio frequencies and microwave frequency bands have already been used or allocated, making it difficult to allocate new frequencies. Furthermore, since radio waves tend to spread easily and have poor directivity, it is necessary to avoid overlapping service areas to prevent interference. Therefore, when attempting to transmit information to vehicles by radio waves, there is a natural limit to the number of transmitters that can be installed at one point in traffic. In addition, when connecting the section from the central transmitting station to the terminal transmitter using a coaxial cable or waveguide, the loss of these transmission lines increases, so in order to realize a long transmission line, it is necessary to use a repeater. This requires installation, etc., and the cost of constructing the transmission line becomes expensive.

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical information transmission system for vehicles traveling on routes, which transmits information to vehicles traveling on routes using light as a carrier.

In order to achieve the above object, the present invention provides an optical information transmission system for vehicles moving on a route, in which a vehicle traveling on a route is equipped with an optical information receiving device for receiving information carried by light, An optical information transmission system for a route-moving vehicle that transmits information sent from a central control device using optical transmitters installed at a plurality of points, wherein a vehicle equipped with the optical transmitter transmits information sent from a central control device. receive one or more information transmission units of optical information when passing near any one of the optical information receivers, store it in an information storage device of said optical information receiver, and then use said stored information display device by an information processing device. It is configured to play.

According to the above method, it is possible to significantly increase the number of transmitting stations, and a system capable of transmitting fine-grained information for each route can be obtained. Furthermore, by connecting the central control unit to the optical transmitter of the terminal using a low-loss optical fiber, the terminal can be installed far away, making it possible to significantly expand the coverage area of the system.

In other words, by effectively utilizing the broadband properties and directivity of light and modulating the light at high speed, the necessary information transmission units can be transmitted all at once in a short time, as if a moving vehicle were passing near an optical transmitter. After the received information is temporarily stored in the optical information receiving device installed in the moving vehicle, the necessary information can be transferred from the storage device even if the moving vehicle is located far from the optical transmitter. It can be played back on a display device.

Next, the system of the present invention will be explained in more detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a system constructed according to the method of the present invention.

In the figure, 1 is a central controller, and 2 is an optical transmitter. In this embodiment, optical transmitters 2 installed at key points on the route are connected to a central controller 1.
a, . . . 2d, information is transmitted through a low-loss, broadband optical fiber 3. The information to be transmitted includes road traffic information, local advertisements,
These are gazettes, directives, etc. It is possible to send the same information to each of the optical transmitters 2a, . . . 2d installed at a plurality of points on the route, or it is also possible to send different information to each point.

The optical transmitter 2 modulates the necessary information transmission unit information at high speed and repeatedly transmits it. A laser is used as the carrier light, which has excellent monochromaticity and can be easily modulated at high speed. Since the laser has good monochromaticity, it is easy to remove extraneous noise such as background light and sunlight scattered light by using a narrow band wavelength selection filter in the receiving device.

When the moving vehicle 4 passes near one optical transmitter 2, the optical information receiving device 5 mounted on the moving vehicle 4 transmits information for at least a certain amount of information transmission unit (for example, 10 Kbytes, 1 record, 1 record, etc.). Receives information about pages (such as pages) and stores them. Furthermore, when the moving vehicle 4 is located at a distance from the optical transmitter 2, the stored information is reproduced in the vehicle by images, sounds, lights, etc. at any time after the reception is completed.

FIG. 2 is a block diagram showing a detailed configuration example of the optical information receiving device 5. As shown in FIG. In FIG. 2, 50 is a light-receiving telescope that focuses a light beam for reception, and 51 is a photodetector. It is sent to the information processing device 52 and stored in the information storage device 53. 54 is an information display device. Since the received signal is high-speed, it is rapidly stored in the information storage device 53 by direct memory access from the photodetector 51. The information processing device 52 is also notified that there is new information received. Thereafter, the information processing device 52 displays the information stored in the information storage device 53 on the information display device 54 according to a predetermined procedure.

Although FIG. 1 shows that the optical information processing device 5 is mounted in one place, in practice, the information display device 54 is mounted near the operator or passenger in the vehicle, and the information display device 54 is mounted near the telescope 50 or the light detector. The device 51 is installed at a location where reception is easy, such as on the roof of a vehicle.

The laser beam emitted by the optical transmitter 2 is sent to the telescope 5.
The time it takes for a zero to cross is not very long, so in order to transmit a large amount of information without wasting it, it is better to encode the information in advance and then transmit it. Codes such as character data and predetermined image patterns are decoded by the optical information processing device 53, converted into corresponding characters and image patterns, and displayed. Further, by transmitting only the data of the changed part of the already transmitted information together with the address indicating the changed part, the length of the necessary transmission unit can be further shortened.

In the photodetector 51, when the received signal level reaches a sufficiently strong level to prevent malfunction, the photodetector 51 detects information from the start signal to the stop signal, which is one transmission unit. It is sent to the information storage device. Since a laser beam with good monochromaticity is used as a carrier,
The influence of background light noise can be minimized. Furthermore, if it is necessary to reliably transmit high-density information, it is preferable to install the optical transmitter 2 on an overpass, under a guardrail, on the roof or eaves of a station building, etc., to reduce background light.

Various modifications can be made to the embodiments described in detail above. As for vehicles, it is possible to target not only cars but also trains and trains.

According to the method of the present invention, an information transmission system that is more resistant to electrical noise than conventional systems can be obtained. It is also possible to transfer some of the functions of the central processing unit 1 to the optical transmitter 2 and perform distributed processing such as data editing.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a system configured according to the method of the present invention, and FIG. 2 is a block diagram showing a detailed example of the configuration of an optical information receiving apparatus of the system shown in FIG. 1... Central control device, 2... Optical transmitter, 3...
Optical fiber line, 4... Moving vehicle, 5... Optical receiving device, 50... Light receiving telescope, 51... Photo detecting device, 52... Information processing device, 53... Information storage device, 54... Information display device .

Claims (1)

[Claims] 1 Vehicles moving on a route are equipped with an optical information receiving device that receives information carried by light,
An optical information transmission system for route-moving vehicles that transmits information sent from a central control unit using optical transmitters installed at multiple points along the route, wherein the vehicle equipped with the optical transmitter is , receives optical information of one information transmission unit or more when passing near any one of the optical transmitters, stores it in the information storage device of the optical information receiver, and then uses the information processing device to store the optical information in the storage device. 1. An optical information transmission system for route-moving vehicles, characterized in that the information transmitted is reproduced on an information display device.