JPH0340616A - Optical space transmission equipment - Google Patents

Abstract

PURPOSE:To always ensure the space transmission line of an optical signal, and to prevent the intermission of an optical signal by providing a light reflection section having a shape reflecting an optical signal being radiated from an optical transmission section into free space in the direction of an optical reception section, at a position between the optical transmission section and the optical reception section. CONSTITUTION:An electric signal being a voice signal of a device 11 is converted into an optical signal 20 at an optical transmission section 12, and radiates from a light emitting element 13 into free space. When an obstacle 19 such as a person crosses an optical path in a space transmission path of the optical signal 20, the optical signal 20 made incident in a light receiving element 14 is shut out, part of an optical signal 21 being radiated in a direction of a ceiling 17 in a room from the light emitting element 13 reaches an optical reflection section 18, the optical signal 21 reaching the optical reflection section 18 is a reflected light, and part of the optical signal 22 reaches the rear side of the obstacle 19. As a result, the optical signal 22 is made incident in the element 14 and the signal transmission system is ensured.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an optical space transmission device that transmits a signal by emitting an optical signal modulated by an electrical signal into free space.

Background of the Invention In recent years, optical space transmission devices have been used as optical remote controllers for video equipment,
It is widely used for remote control of audio equipment, air conditioning equipment, etc., and for spatial transmission of audio signals from audio equipment.

FIG. 3 shows the configuration of a conventional optical space transmission device for transmitting audio signals. In FIG. 3, 1 is a device such as an audio equipment used indoors, 2 is an optical transmitter built into the device 1, 3 is a light emitting element of the optical transmitter 2, 5 is an optical receiver, and 4
is a light receiving element of the optical receiver 5, and 6 is a headphone that converts an audio signal into sound.

In the figure, an optical signal 8 modulated by, for example, an audio signal is emitted from a light emitting element 3 of an optical transmitter 2 into free space. After this optical signal 6 propagates in space, a part of it enters the light receiving element 4. The incident optical signal is converted back into an electrical signal by the optical receiver 5, and reproduced into audio by the headphones 6, completing the signal transmission. As described above, an optical space transmission device has been constructed in the past.

Problem to be Solved by the Invention However, in such a conventional configuration, as shown in FIG. 3, when an obstacle 7 such as a person passes through the optical path of the optical signal 8 transmitted in space, the optical path is interrupted. There was a problem in that the audio signal was blocked by the obstacle 7 and the transmission of the audio signal was interrupted.

The present invention solves these problems, and aims to provide an optical space transmission device for indoor use that ensures signal transmission even when obstacles occur from time to time. This is what I did.

Means for Solving the Problems In order to solve the problems, the present invention specifies a part of the optical signal emitted from the optical transmitter using a light reflecting section provided in a place where it is not affected by obstacles. The reflected optical signal is reflected in a direction within the range of , and a part of the reflected optical signal is incident on the optical receiver.

Effect of the present invention With the above-described configuration, a part of the optical signal emitted from the optical transmitter is reflected by a light reflecting section provided on the ceiling of the room, which is not affected by the obstacle, and is reflected behind the obstacle. As a result, even if an obstacle occasionally occurs between the optical transmitter and the optical receiver, it functions as an excellent optical space transmission device that ensures optical signal transmission.

Embodiments Hereinafter, embodiments of the present invention will be explained using the drawings of FIG. 1 and FIG. 2.

FIG. 1 shows the configuration of an optical space transmission device in an embodiment of the present invention. In the figure, 11 is a device such as audio equipment or video equipment installed indoors, 12 is an optical transmitter that converts an audio electrical signal into an optical signal, 13 is a light emitting element that emits an optical signal into free space, 14 is a light emitting element 13
15 is a light receiving unit that amplifies the electrical signal from the light receiving element 14 and converts it into an audio signal; 16 is a headphone that converts the audio signal into sound; 18 is attached to the indoor ceiling 17,
A part of the optical signal emitted from the optical transmitter 13 is sent to the optical receiver 15.
19 is an obstacle such as a person, and 20 to 22 are arrows indicating optical signals propagating in space.

The operation of the optical space transmission device configured as described above will be described below.

First, an audio electrical signal from the device 11 is converted into an optical signal 20 by the optical transmitter 12, and is emitted from the light emitting element 13 into free space. Under normal conditions, a part of the optical signal 20 traveling straight in free space is directly incident on the light receiving element 14, and the light receiving unit 1
After being converted into an electrical signal again in step 5, the signal is output as audio from the headphones 16. However, if an obstacle 19 such as a person crosses the optical path during the spatial transmission path of the optical signal 20, the optical signal 20 entering the light receiving element 14 is blocked.

On the other hand, a part of the optical signal 21 emitted toward the indoor ceiling 17 from the same light emitting element 13 reaches the light reflecting section 18 . The light reflecting section 18 is provided on the ceiling at a position between the optical transmitting section 12 and the optical receiving section 15, and reflects the optical signal 21 from the light emitting element 13 while diffusing it in the direction of the optical receiving section 15. It is made in the shape of a surface. Therefore, the optical signal 21 reaching the light reflecting section 18 becomes reflected light, and a part of the optical signal 22 reaches the rear side of the obstacle 19. the result,
The optical signal 22 enters the light receiving element 14, and a signal transmission system is established.

In the embodiment shown in FIG.
Since the intensity (power) of the light is different between the two, the optical receiver 1
5 has a function of outputting an electric signal of a constant magnitude even if the intensity of the optical signal incident on the light receiving element 14 changes.

As described above, the feature of this embodiment is that the optical signal 21 emitted from the light emitting element 13 is placed between the optical transmitter 12 and the optical receiver 15 at a position on the indoor ceiling 17 that is not affected by the obstacle 19.
An optical space transmission device is constructed by providing a light reflecting section 18 that reflects the light toward the optical receiving section 15.

With this configuration, even if an obstacle 19 occurs on the optical path between the optical transmitter 12 and the optical receiver 15, the optical signal 2 is emitted from the light emitting element 13 of the optical transmitter 12 in a direction free of the obstacle 19.
1 is reflected by the light reflecting section 18 and reaches the rear side of the obstacle 19. As a result, the effect of always securing the transmission path of the optical signal is obtained, and the sound from the headphones 16 is not interrupted. It functions as an excellent optical space transmission device.

Note that in this embodiment, a part of the optical signal 21 emitted from the light emitting element 13 is reflected by the light reflecting section 21, but in consideration of the attenuation of the intensity of light due to reflection, The intensity of the light emitted in the direction of the light reflecting section 21 may be made larger than that in other directions.

Furthermore, in this embodiment, the light reflecting section 1 that reflects the optical signal is
8 has been described as one installed on the ceiling of the room, but the installation position is such that it is not affected by obstacles 19 and can reflect the optical signal 21 from the optical transmitter 12 in the direction of the optical receiver 15. It goes without saying that the light reflecting portions 18 may be provided at any position, and any number of light reflecting portions 18 may be provided as required.

A second embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a diagram illustrating the configuration of a light reflecting section used in the optical space transmission apparatus of the present invention shown in the embodiment of FIG. 1. In the figure, 12 is an optical transmitter that emits an optical signal into free space, 15 is an optical receiver that receives the optical signal propagated in free space, 17 is a ceiling in the room, and 19 is an optical transmitter 12 and an optical receiver. 23 is a lighting fixture attached to the ceiling 17; 24 is a lighting tube; here, it is a fluorescent lamp;
5 is a cover for the fluorescent lamp 24; 21 and 22 are arrows indicating optical signals; and 26 is an arrow indicating visible light for illumination. The cover 25 of the lighting fixture 23 shown in the figure has the same function as the light reflecting section 18 described in FIG. 1.

The operation of the light reflecting section configured as described above will be described below.

First, visible light 26 from the fluorescent lamp 24 passes through the cover 25 and illuminates the room. The cover 25 of the lighting fixture 23 is coated with a thin vapor-deposited film of a material, such as aluminum, that transmits visible light 26 with almost no loss of light and reflects infrared light, so that the infrared light propagated in free space is It has a shape that allows it to receive light and reflect it in a specific range of directions.

Furthermore, in an optical space transmission device that propagates an optical signal in free space, infrared light is generally used as the optical signal. Therefore, a part of the optical signal 21 emitted from the optical transmitter 12 of the optical space transmission device enters the surface of the cover 25 and is then reflected in the direction of the optical receiver 15 located behind the obstacle 19. A part of the optical signal 22 enters the optical receiver 15 to establish an optical signal spatial transmission system.

Note that the light receiving section 15 is configured to detect only infrared light of a specific wavelength, and is not affected by the visible light 26 emitted from the fluorescent lamp 24 at all.

As described above, the feature of this embodiment is that it consists of a member that transmits visible light and reflects infrared light, receives an optical signal propagated in free space, and reflects this optical signal in a specific range of directions. The light reflecting portion of the shaped optical space transmission device is configured as a part of the lighting fixture 23.

With this configuration, even if an obstacle 19 occurs on the optical path between the optical transmitter 12 and the optical receiver 15, as in the embodiment shown in FIG. The optical signal 21 emitted from the lamp is reflected by the cover 25 of the lighting fixture 23, which functions as a light reflecting part, and reaches the rear side of the obstacle 19. As a result, the optical signal transmission path is always blocked. The effect of ensuring this can be achieved.

Furthermore, since the cover 25 of the lighting fixture also serves as a light reflecting part, there is no need to provide a special light reflecting part in the room where the optical space transmission device is used, and the lighting fixture is generally placed in the center of the room. Since it is installed on the ceiling of the
9, the effect of being provided at a suitable position as an optical signal reflecting section between the optical transmitting section 12 and the optical receiving section 15 can be obtained, and it functions as an excellent light reflecting section.

In the embodiment shown in FIG. 2, the light reflecting part was explained as a material that reflects infrared light and transmits visible light. Any reflective member may be used.

Furthermore, in the embodiment shown in FIG. 2, the light reflecting section was provided on the cover 25 of the lighting fixture 23, but the light reflecting section was
If it has a shape that receives an optical signal propagated in free space and reflects this optical signal in a specific range of directions, it can be used as a part of a lighting equipment, whether it is a reflector of a lighting equipment or a decorative part of a jump rear. If so, you can place it anywhere.

Furthermore, in the embodiments shown in FIGS. 1 and 2, it has been explained that the optical signal propagating in free space is one type of optical signal emitted from the device in one direction, but two or more types of optical signals can be transmitted in one direction. Needless to say, it may be used or transmitted in both directions.

Effects of the Invention As described above, according to the present invention, a shape is provided between the optical transmitter and the optical receiver to reflect the optical signal emitted from the optical transmitter into free space in the direction of the optical receiver. By providing a light reflecting section with Since the optical signal is reflected by the object and reaches the rear side of the obstacle, it always ensures a spatial transmission path for the optical signal and has the effect that the optical signal is not interrupted, making it a superior optical spatial transmission device compared to conventional methods. This is something that can be achieved.

Furthermore, in the above embodiment, the light reflecting part is a part of the lighting equipment, and is made of a member that reflects light with a wavelength in the infrared region, and receives an optical signal propagated in free space and converts this optical signal into a part of the lighting equipment. Since it is composed of a part with a shape that reflects light in a specific range of directions, in other words, a part of the lighting equipment also serves as a light reflection part, so it is possible to have a light reflection part in the room where the optical space transmission device is used. There is no need for special installation, and since lighting equipment is generally mounted on the ceiling in the center of the room, it is not affected by obstacles and can be used as a reflection part for optical signals between the optical transmitter and the optical receiver. The effect can be obtained by placing it in a suitable position, and it functions as an excellent light reflection part.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a spatial optical transmission device according to an embodiment of the present invention, FIG. 2 is a schematic diagram of a spatial optical transmission device according to another embodiment of the present invention, and FIG. 3 is a diagram of a conventional spatial optical transmission device. It is a configuration explanatory diagram. 11... Device, 12... Optical transmitter, 1
3... Light emitting element, 14... Light receiving element,
15... Light receiving section, 16... Headphones, 17... Ceiling, 18... Light reflecting section, 19... Obstacle , 20-22...
Arrow indicating optical signal, 23...Lighting equipment, 24.
...Fluorescent light, 25...Cover 26...
...This is an arrow indicating visible light.

Claims (2)

[Claims] (1) An optical transmitter that converts an electrical signal into an optical signal and emits this optical signal into free space; and an optical transmitter that receives a part of the optical signal propagated in space and transmits the optical signal in a specific range direction. A light comprising: a light reflecting section having a shape to reflect the light; and an optical receiving section receiving a part of the optical signal reflected by the reflecting section and converting the optical signal into an electrical signal. Spatial transmission device. (2) The light reflecting part is a part of the lighting equipment, and this part is made of a material that reflects light with wavelengths in the approximately infrared region. The optical space transmission device according to claim 1, which has a shape that reflects the optical signal in the direction of the range.