JP2983600B2 - Optical space transmission equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an optical space transmission apparatus according to a data transmission technique between a moving body such as a train and a fixed body on the ground side.

[Conventional technology]

As a light source for an optical space transmission device that performs data communication between a moving body such as a train and a fixed body such as a platform, an infrared light emitting diode or a semiconductor laser is generally used.
These light sources have low output. For this reason, on the light-emitting side, an optical system such as a lens is used to narrow down the light beam and most of the light emitted is directed to the light-receiving side. On the light-receiving side, a large-diameter optical system is used to reduce the emitted light beam. In order to capture as much as possible, the conventional optical space transmission apparatus is put to practical use by narrowing down the emitted light beam and limiting the light receiving field. However, in the case of a device configuration in which the optical axis of the emitted light beam or the light-receiving field of optical space transmission is substantially perpendicular to the traveling direction, in an optical system where the light-emitting beam is narrow and the light-receiving field is narrow, the moving body stops. If it shifts, transmission cannot be performed.

Therefore, in general, in the case of optical space transmission between the train 50 and the fixed body side 51, since the emitted light beam B is narrowed and the light receiving field of view E is also narrowed as described above, it is easy to match the emitted light beam B with the light receiving field of view E. As shown in FIG.
The devices are arranged so that the optical axes of the 2,53 emitted light beams B and the light receiving field E are substantially parallel to the line 54.

[Problems to be solved by the invention]

However, in such a configuration, the installation on the fixed body side must be arranged so as not to interfere with the train operation, so the train
The distance 1 between the emitter / receiver 52 on the 50 side and the emitter / receiver 53 on the fixed body side 51 is from 50 m to 100 m.

Also, in this type of optical space transmission device, the transmitter / receiver 52 for the mobile body is installed in the driver's seat at the head of the train 50, and the transmitter / receiver 53 on the fixed body side is installed next to the line 54. Therefore, devices that are not necessary for driving the train are installed in the driver's seat, which obstructs a part of the driver's view, which is not preferable for safe driving. In addition, rain and snow adhere to the window glass in front of the train, which directly affects the weather, such as attenuating or blocking the light emitted from the optical space transmission device (wiper for securing the driver's view). However, the field of view of the optical space transmission device is not secured.) Therefore, it cannot be said that the installation place is the most suitable place.

In addition to the installation in the driver's seat, installation under the floor is also conceivable, but in this case, since the optical space transmission device on the fixed body side is installed at a low position, it can be used in a bad environment atmosphere such as railway-specific iron adhesion. For reasons such as having problems placed,
It is not preferable to perform optical space transmission in the traveling direction.

The present invention has been made in view of the above problems,
It is an object of the present invention to provide an optical space transmission device that has a short communication distance, has excellent communication performance, and is economical in terms of installation space and operation cost.

[Means for solving the problem]

In order to achieve the above object, the optical space transmission apparatus according to the present invention comprises a transmitter / receiver on the fixed body side and a transmitter / receiver mounted on the side of the movable body facing the transmitter / receiver, respectively. A light distribution that is longer in the traveling direction of the moving body is configured by a cylindrical lens that can obtain an appropriate light emission angle in the detector, and the light emission is also performed in the light receiver through a light receiving element and a light receiving range limiting unit including a cylindrical lens. A light-receiving field of view that is longer in the traveling direction of the moving body in opposition to the light receiving device is configured to receive light emitted from each of the light-receiving devices when the light-emitting and light-receiving devices face each other. Things.

Then, a plurality of light emitting elements are arranged in parallel so that the light emitting / receiving device on the fixed body side and the light emitting / receiving device mounted on the side surface on the moving body side facing the light emitting / receiving device can obtain an appropriate light emitting angle in each light emitting device. The light distribution is configured to be longer in the traveling direction of the moving body, and the light receiver is also opposed to the light emitter through the light receiving range limiting means by a light receiving element and a field stopper. It is possible to configure a light-receiving field of view that is longer in the direction, and to take measures to receive light emitted from each of the light-receiving devices when the light-emitting and light-receiving devices face each other.

The optical space transmission apparatus according to the present invention includes
It is preferable to adopt an optical space transmission method in which the light source of the light emitting device is turned on when the light emitting / receiving device on the moving body side approaches the light receiving device.

Further, in the optical space transmission apparatus according to the present invention, when the light emitting / receiving device on the moving body side receives the light emitted from the light emitting device on the fixed body side, the light source of the light emitting device for the moving body is turned on. It is preferable to adopt the optical space transmission method described above.

It should be noted that the detection of the state where "the light emitting / receiving device on the moving body side is close to the light emitting / receiving device on the fixed body side" described above can use a train approach signal at a station which has been conventionally used.

[Action]

The optical space transmission device turns on a light source for optical space transmission during a period immediately before or after a time during which transmission is possible or a time when transmission becomes possible, when the light emitting / receiving device on the moving body side approaches the light emitting / receiving device on the fixed body side. Or, when the emitter / receiver on the moving body side approaches the emitter / receiver on the fixed body side, it receives the optical space transmission optical signal from the emitter / receiver on the fixed body side and emits / receives the light on the mobile body side.
The light source for optical space transmission of the light receiver is turned on to emit an optical signal. At this time, the emission light beam and the light receiving field of the light emitting / receiving device on the moving body side and the fixed body side are widened through the cylindrical lens, the plurality of light receiving elements or the light receiving range limiting means,
Transmission is possible even if the stop position of the moving body is shifted, and the optical transmission distance can be drastically shortened, so that the received light intensity increases (the reaching energy of the optical signal is inversely proportional to the square of the distance). Thus, the influence of disturbance can be easily eliminated, and the reliability of communication can be improved.

〔Example〕

Hereinafter, an embodiment of the free-space optical transmission apparatus according to the present invention will be described as a first embodiment.
The description will be made with reference to FIGS.

In the drawing, 1 is a track 3 laid along a platform 2
This is a train running on the upper side. The train 1 is a moving body side, and the platform 2 is a fixed body side.

The moving body-side light emitting / receiving device 4 is fixed to an upper portion of the side of the train 1 near the door closing confirmation light 6, for example, and the fixed body side emitting / light receiving device 5 is a mounting position of the destination guide plate 7 of the platform 2, a speaker or the like. It is fixed opposite to a nearby passenger at a height that does not hinder passengers.

The two-beam / light receivers 4 and 5 (see FIG. 4) have a light-emitting beam B and a light-receiving field E which are wide in the horizontal direction and narrow in the vertical direction.
In FIG. 2A, an optical system composed of a cylindrical lens 10 is arranged on the front optical axis L of the light emitting element 9 in FIG. Form P1. In FIG. 3A, a plurality of light emitting elements 9, 9... Are arranged in parallel in the horizontal direction to form a horizontally long optical pattern P2 as shown in FIG. 3B. Reference numeral 11 denotes a light receiver. The light receiver 11 forms a field stopper (aperture) 13 on the optical axis L in front of the light receiving element 12. At this time, the spread angle θ2 of the light receiving field is changed by changing the distance l1 between the light receiving element 12 and the field stopper 13 or opening the field stopper 13.
The desired light receiving field of view can be obtained by changing the width l2 of 14, and the same light receiving field can be obtained by using a cylindrical lens as shown in FIG. it can.

That is, according to the above configuration, the emitted light beam B and the received light field of view E are configured to have the spread angles θ1 and θ2 in the traveling direction F of the train, and such an optical configuration that is wide in the horizontal direction and narrow in the vertical direction. In the horizontal direction, a distance (about 2 to 3 m) that can cover the stopping error of the moving object, and in the vertical direction, if there is a light emitting beam that can respond to the angle at which the moving object tilts or moves up and down (about 1 m), if the light receiving field of view expands Good. As a result, optical space transmission between the train 1 and the platform 2 is enabled, and the transmission distance L is shorter than that of the conventional optical space transmission apparatus, and is 3 to 3 hours.
6m.

The optical transmission distance L is approximately 1/10 of the optical transmission distance (50 to 100 m) under the installation conditions (the optical system is directed substantially parallel to the traveling direction) as in the conventional optical space transmission device. , The received light intensity increases approximately 100 times.

〔The invention's effect〕

Since the optical space transmission apparatus according to the present invention is configured as described above, the optical transmission distance is significantly higher than the optical transmission distance when the communication direction is directed substantially parallel to the traveling direction of the moving object. Since the length can be shortened, the intensity of received light can be increased, the influence of disturbance can be easily eliminated, and the reliability of communication can be improved. In addition, by limiting the communication time, the life can be extended as compared with the case where the light source is always turned on, and the reliability of electronic components and devices can be obtained by suppressing heat generation. It is possible to improve the reliability of the light source and save power. Furthermore, when not using a focusing optical system such as a lens,
In addition to being free from the effects of burnout due to sunlight, etc., it also has a wide field of emitted light and light, so it is possible to transmit even if the stop position of a moving object such as a train is shifted, and it is easy to adjust. Therefore, the effect of the present invention is extremely large.

[Brief description of the drawings]

FIG. 1 is a schematic plan view (a) and an elevation view (b) showing the principle of the free-space optical transmission device according to the present invention, and FIG. 2 is a plan sectional view showing one embodiment of a light emitting / receiving device. (A) and an explanatory diagram (b) showing a light distribution pattern, FIG. 3 is a plan sectional view (a) showing another embodiment of a light emitting / emitting device of a light emitting / receiving device, and an explanatory diagram (b) showing a light distribution pattern. FIG. 4 is a plan sectional view showing one embodiment of the photodetector, and FIG. 5 is a schematic diagram showing the principle of a conventional optical space transmission device. DESCRIPTION OF SYMBOLS 1 ... Train, 2 ... Home 3 ... Track, 4 ... Movable body side light emitting / receiving device 5 ... Fixed body side emitting / light receiving device 6 ... Door closing confirmation light, 7 ... Destination guide plate 8 ... Light emission Device 9 Light-emitting device 10 Cylindrical lens 11 Light-receiving device 12 Light-receiving device 13 Field stopper

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B61L 1/00-29/32

Claims (4)

(57) [Claims] 1. A light emitting / receiving device on a fixed body side and a light emitting / receiving device mounted on a side surface on a moving body side opposed to the light emitting / receiving device are each formed by a cylindrical lens capable of obtaining an appropriate emission angle in the light emitting device. The light distribution is configured to be longer in the traveling direction of the moving body, and also in the light receiving device, through the light receiving element and the light receiving range limiting means by the cylindrical lens, the light is longer in the traveling direction of the moving body facing the light emitting device. An optical spatial transmission device having an optical spatial transmission system, wherein the optical spatial transmission system has a light receiving field of view and receives light emitted from each of the light receiving devices when the two light emitting and light receiving devices face each other. 2. A light emitting element in which a light emitting / receiving device on the fixed body side and a light emitting / receiving device mounted on the side surface on the moving body side opposite to the light emitting / receiving device so that an appropriate emission angle can be obtained in the light emitting device. A plurality of light sources are arranged in parallel to form a light distribution that is longer in the traveling direction of the moving body, and the light receiver is also opposed to the light emitter by a light receiving element and a light receiving range limiting means by a field stopper. It has an optical space transmission system that has a light-receiving field of view that extends in the body's direction of travel, and receives light emitted from each light-receiving device when both light-emitting and light-receiving devices face each other. Optical space transmission equipment. 3. The optical space according to claim 1, wherein the light source of the light emitter is turned on when the light emitter / receiver on the movable body approaches the light emitter / receiver on the fixed body side. Optical space transmission equipment with a transmission system. 4. The light source of the light emitter for the movable body is turned on when the light emitting / receiving device on the movable body side receives a light beam emitted from the light emitter on the fixed body side. An optical space transmission apparatus having one, two, or three optical space transmission systems.