JP2007004203A - Light transmission body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light transmission body using an optical fiber which does not make a person feel so much dazzling without the need for provision of a light source within a room. <P>SOLUTION: The light radiated from the light source 12 is made incident on the optical fiber 13, conducts the optical fiber 13 and is made incident on a light scattering body 14 provided at the end of the optical fiber 13. The light scattering body 14 has an approximately hemispherical shape to scatter the light made incident from the optical fiber 13, and the scattered light is radiated therefrom. The scattered light provides illumination light as it is. Also, the illumination light can be used for communication. If the modulated light is received in a photodetecting section 22 of a signal receiver 21 and is demodulated by a demodulation section 23, the information sent by the illumination light can be received. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a light guide using an optical fiber.

  Conventionally, optical fibers have been used for communication and illumination. FIG. 6 is an explanatory diagram of an example of a lighting device using a conventional optical fiber. In the figure, 1 is a light source and 2 is an optical fiber. As shown in FIG. 6, a conventional luminaire using an optical fiber 2 receives light emitted from a light source 1 such as a halogen lamp, an LED, or a laser from one end of the optical fiber 2 and from the other end. Release light into space. This emitted light is used as illumination.

  In this system, light is emitted from a point light source that is one end of the optical fiber 2 and light having good straightness is emitted, so that a large amount of light is emitted in a narrow viewing angle. Therefore, when the end of the optical fiber 2 is viewed directly with the eyes, it becomes quite dazzling. In addition, there is a drawback that a wide range cannot be illuminated. For this reason, a diffusion plate is provided at the exit end of the optical fiber 2 to diffuse the light emitted from the end of the optical fiber 2 to radiate light over a wide range and reduce glare.

  On the other hand, with the progress of high-speed communication technology, indoor wireless communication technology using light has come to be used. In particular, LANs using infrared rays are becoming popular not only in offices but also in homes. However, in order to use the infrared LAN, it is necessary to install a transceiver as an access point on the ceiling. In general, if there is an obstacle between the access point and the terminal, transmission / reception becomes impossible. Furthermore, there is a problem that high-quality communication cannot be performed at a high speed because it is necessary to suppress power from the influence on the human body such as eye-safe.

  As a communication method for solving such a problem, a communication method using illumination light is considered. For example, it is described in Non-Patent Document 1. However, conventionally, only lighting fixtures that directly illuminate in the same way as existing lighting devices have been considered.

Toshihiko Komine, Yuichi Tanaka, Masao Nakagawa, “Fusion system of white LED illumination signal transmission and power line signal transmission”, IEICE technical report, The Institute of Electronics, Information and Communication Engineers, March 12, 2002, Vol. 101, no. 726, pp. 99-104

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a light guide body that does not require a light source in a room and does not feel so much glare.

  The present invention is a light guide, which is an optical fiber that conducts light emitted from a light source, and a substantially hemispherical shape that scatters and emits light provided at an end of the optical fiber and conducted through the optical fiber. It has the light-scattering body of this.

  The optical fiber and the light scatterer can be made of a plastic material. Further, the optical fiber and the light scatterer can be integrally configured. Furthermore, a reflecting portion whose surface facing the light scatterer is a mirror surface can be provided on the plane portion of the light scatterer.

  When a light source that emits ultraviolet light or blue light is used as the light source, the light scatterer may be mixed with a fluorescent material and illuminated with fluorescent light.

  According to the present invention, it is only necessary to install a light scatterer in the room, and there is no need to install a large-sized fixture like a conventional lighting fixture. Further, wherever the light source is present, it is only necessary to send light through an optical fiber, so there is no need to provide a light source in the room as in a conventional lighting fixture. Further, since the light that has passed through the optical fiber is emitted as scattered light by the light scatterer, even if it is viewed directly, it does not feel so much glare, and a wide range can be illuminated.

  FIG. 1 is a conceptual diagram showing a first embodiment of the present invention. In the figure, 11 is a light source controller, 12 is a light source, 13 is an optical fiber, 14 is a light scatterer, 15 is a reflector, 21 is a receiver, 22 is a light receiver, and 23 is a demodulator. The light source 12 emits light for illumination, and an element having high-speed response characteristics such as an LED or a laser diode is used.

  The light source control unit 11 controls blinking or light amount of the light source 12 according to information to be transmitted. As a result, modulated light is emitted from the light source 12.

  The optical fiber 13 conducts light from the light source 12 from one end to the other end. As the type of the optical fiber 13, both glass fiber and plastic optical fiber (POF) can be used. When both are compared, since the POF is lighter and generally the fiber diameter can be increased, the energy density of light per unit cross-sectional area of the POF is lower than that of the glass fiber. Therefore, higher power light energy can be sent. POF is easier to connect and more flexible than glass fiber.

  The light scatterer 14 is provided at the end of the optical fiber 13 and scatters and radiates light that has been conducted through the optical fiber 13. As the light scatterer 14, a high-intensity light-scattering polymer light guide can be used. The high-intensity light-scattering polymer light guide can be composed of a high-intensity light-scattering light guide (HSOT) polymer in which, for example, a micron-order heterogeneous structure is formed in a photonics polymer, and is highly efficient as a lighting fixture It becomes a scatterer of visible light. When POF is used as the optical fiber 13, the light scatterer 14 and the optical fiber 13 are made of plastic, so that both can be integrated. For example, both can be manufactured separately and integrated, or can be manufactured integrally by adjusting additives and manufacturing conditions during manufacturing. The shape of the light scatterer 14 is arbitrary. For example, in FIG. 1, the light scatterer 14 has a hemispherical shape, and the end of the optical fiber 13 is connected to the center thereof.

  The reflecting plate 15 has a mirror surface on the surface facing the light scatterer 14, returns the scattered light from the upper part of the light scatterer 14 to the light scatterer 14 again, and scatters from the lower part of the light scatterer 14. Increasing light. The reflection plate 15 may be provided as a separate member, or the reflection surface may be formed by applying or vapor-depositing a reflection material on the reflection surface. In this example, it is assumed that the hemispherical light scatterer 14 as shown in FIG. 1 is used to illuminate, for example, from the indoor ceiling. In such a case, the planar portion of the hemisphere is on the ceiling side, and it is not necessary to emit scattered light from this surface. Therefore, the reflector 15 is provided on the planar portion of the light scatterer 14 to improve the illumination efficiency. However, in the case where it is not necessary to improve the illumination form or the illumination light rate, the reflector 15 can be provided without being provided.

  The receiver 21 receives the modulated scattered light received from the light scatterer 14 through the optical fiber 13 as described above, and receives the transmitted information. As a configuration for that, the light receiving unit 22 and the demodulating unit 23 are included. The light receiving unit 22 receives the modulated scattered light emitted from the light scatterer 14 through the optical fiber 13, converts it into an electrical signal, and sends it to the demodulation unit 23. The demodulator 23 demodulates the electrical signal corresponding to the amount of light received by the light receiver 22 and extracts the original information. As a result, the transmitted information can be received.

  An example of the operation in the above-described first embodiment of the present invention will be described. In the present invention, when information is not sent, it can be used as it is as a lighting device. That is, light emitted from the light source 12 is incident on the optical fiber 13, and the optical fiber 13 is conducted and incident on the light scatterer 14. The light scatterer 14 scatters light incident from the optical fiber 13 and emits scattered light. The light emitted from the hemispherical upper plane is reflected by the reflecting plate 15 and incident on the light scatterer 14 again to be scattered and emitted. Thus, the emitted light scattered and emitted by the light scatterer 14 may be used as illumination light.

  Even when used as an illumination device in this way, the light scatterer 14 is provided at the exit end of the optical fiber 13, and the light that has passed through the optical fiber 13 is emitted as scattered light. Therefore, the luminance per unit area is lower than the method of directly irradiating from the end of the optical fiber 13. Therefore, even if it looks directly, it does not feel so much glare. Further, the light scatterer 14 can illuminate a wide range.

  Further, when the light scatterer 14 and the optical fiber 13 are integrated, it is only necessary to install the light scatterer 14 in the room, and there is no need to install a large instrument as in a conventional lighting fixture. Further, wherever the light source 12 is present, it is only necessary to send the light through the optical fiber 13, and thus it is not necessary to provide a light source in the room as in a conventional lighting fixture. Therefore, for example, when using in a place where an electrical short circuit or the like becomes a problem, it is possible to provide the light source 12 in a separate room and lay the optical fiber 13 up to the place to use it as illumination. As a result, problems such as electric leakage and short circuit do not occur, and illumination can be performed safely.

  When transmitting information, the information to be transmitted is given to the light source control unit 11. The light source control unit 11 controls blinking or light amount of the light source 12 according to the received information to be transmitted, and light modulated in accordance with the information to be transmitted is emitted from the light source 12. As in the case of the illumination described above, the modulated light emitted from the light source 12 is incident on the optical fiber 13, is conducted through the optical fiber 13, and is incident on the light scatterer 14. The light scatterer 14 scatters the modulated light incident from the optical fiber 13 and emits scattered light. Even if scattering occurs in the light scatterer 14, the light scatterer 14 is not affected as long as the modulation frequency is lower than the light frequency. Therefore, the modulated scattered light is emitted from the light scatterer 14.

  Further, since the element having the high-speed response characteristic is used as the light source 12 as described above, the light source control unit 11 can perform high-speed blinking or light amount control, and modulated scattered light emitted from the light scatterer 14. However, it blinks at high speed or the light quantity fluctuates. However, even if blinking or light quantity fluctuation is performed, if it is high speed, blinking or light quantity fluctuation is not perceived by human eyes, and it appears to shine with a substantially constant light quantity. Therefore, even if the scattered light emitted from the light scatterer 14 is modulated, it can be used as illumination light as it is.

  When information is received, the modulated scattered light emitted from the light scatterer 14 may be received by the light receiving unit 22 of the receiver 21. The light received by the light receiving unit 22 is converted into an electrical signal and passed to the demodulation unit 23. Information can be acquired by demodulating by the demodulator 23.

  In this way, illumination can be performed and information can be transmitted. In communication using a conventional optical fiber, it is necessary to route the optical fiber to the receiver, and it is difficult to move the receiver. However, in the present invention, information can be received anywhere where illumination light can be received. In addition, the receiver is movable because it is not necessary to be directly connected to the optical fiber. For example, the receiver 21 can be used in combination with a portable terminal. In the case of existing infrared communication or wireless communication, it is necessary to provide a dedicated transmitter separately from the lighting fixture. However, in the present invention, the light scatterer 14 is usually provided as a lighting fixture provided indoors, and communication can be performed together with illumination by laying the optical fiber 13 instead of the electric wire.

  Further, since the scattered light is emitted by the light scatterer 14, the illumination range can be widened, so that the communicable range can be widened. Further, high power of several watts to several tens of watts is required to perform illumination, but since the power can be used for communication, high-speed and high-quality communication can be performed.

  FIG. 2 is a conceptual diagram showing a modification of the first embodiment of the present invention. The reference numerals in the figure are the same as those in FIG. Reference numeral 16 denotes a phosphor. In the second modification, an ultraviolet or blue LED or laser diode is used as the light source 12. Further, the phosphor 16 is mixed in the light scatterer 14.

  Ultraviolet or blue light emitted from the light source 12 enters the light scatterer 14 through the optical fiber 13. Then, similarly to a fluorescent lamp or the like, the phosphor 16 in the light scatterer 14 is excited by the incident ultraviolet light or blue light, and white light is emitted. This white light is emitted from the light scatterer 14. Illumination can be performed using the light emitted from the light scatterer 14 as illumination light. In addition, if the modulated ultraviolet light or blue light is emitted from the light source 12 by blinking or controlling the amount of light according to the information to be transmitted, the white light modulated from the light scatterer 14 is emitted. If this is received by the light receiving unit 22 of the receiver 21, information can be transmitted.

  FIG. 3 is a conceptual diagram showing a second embodiment of the present invention. The reference numerals in the figure are the same as those in FIG. In the second embodiment, an example in which a plurality of optical fibers 13 are connected to one light scatterer 14 and light of different wavelengths is conducted to each optical fiber 13 is shown. In the example shown in FIG. 3, red, green, and blue light sources are used as the light sources 12, and light of colors emitted from the respective light sources 12 is incident on the three optical fibers 13.

  Red, green, and blue light incident on the respective optical fibers 13 are incident on the light scatterers 14 through the respective optical fibers 13. The light of each color incident on the light scatterer 14 is mixed by being scattered in the light scatterer 14 and emitted as white light. Therefore, when the light emitted from the light scatterer 14 is used as illumination light, it can be used as a white light source. Of course, in addition to being used as a white light source, illumination light of any color can be created by adjusting the intensity of light of each color.

  When performing communication, in addition to simultaneously driving and controlling these light sources 12, it is also possible to drive only a part of them. In the example shown in FIG. 3, only the LED or laser diode that emits red light is driven and controlled, and the drive control is not performed for the other green and blue LEDs or laser diodes. In this way, only red light is modulated, and light of other colors is not modulated. For example, such a configuration is effective when the sensitivity of the light receiving unit 22 of the receiver 21 has a peak in red or infrared.

  When the light of some colors is modulated as described above, it is desirable that the receiver 21 receives and modulates the modulated light component. For example, when red light is modulated as in the example shown in FIG. 3, a filter that transmits red light is provided, a light receiving unit 22 having high light receiving sensitivity is used for red light, or a red light using a prism. If the red light is selectively received and demodulated by the demodulator 23 by various known methods such as spectroscopic analysis, information can be received more reliably.

  The light transmitted to the plurality of optical fibers 13 is arbitrary, and is not limited to red, green, and blue light as described above, and the intensity of the light can be freely changed. For example, it is possible to increase the amount of light by using the same color light. Further, when the red, green, and blue light sources 12 are used as described above, it may be configured such that three colors of light are incident on one optical fiber 13. Further, the color of light to be modulated when transmitting information is not limited to red, and the light of one or more other colors may be modulated.

  In the configuration shown in FIG. 3, each light source 12 can be individually driven and controlled according to different information to transmit a plurality of information. That is, information 1 can be transmitted by red light, information 2 can be transmitted by green light, and information 3 can be transmitted by blue light. Also in this case, if the color of the light received on the receiver 21 side is selected, the information transmitted by the light of the selected color can be received.

  Further, for example, in addition to one or a plurality of optical fibers 13 that transmit illumination light, an optical fiber for information transmission is provided, and information is transmitted by controlling a light source corresponding to the optical fiber. You can also In this case, for example, information can be transmitted without changing the color of the illumination light by using a white light source. Further, for example, by using infrared light, it is possible to transmit information by infrared light.

  FIG. 4 is a schematic configuration diagram showing a modification of the second embodiment of the present invention. When modulating only some of the light colors, for example, as shown in FIG. 4, the modulated light is supplied to the light scatterer 14 through the optical fiber 13 for only the light source 12 that is driven and controlled by the drive control unit 11. The light source 12 that emits other colors may have a configuration in which the emitted light is directly incident on the light scatterer 14. Even in this case, the light of the color incident in the light scatterer 14 is mixed and synthesized and can be used as illumination light. At the same time, light of a specific color is modulated, and information can be received by receiving this light component by the light receiving unit 22 of the receiver 21 and demodulating it by the demodulating unit 23. FIG. 4 shows an example in which red light is modulated. However, the present invention is not limited to this. Blue and green light may be modulated, or any two of the three colors may be modulated. Good.

  FIG. 5 is an explanatory diagram of an application example of the present invention. In this example, information is distributed to a plurality of rooms. As described above, the present invention can also be used as a lighting fixture. Therefore, the example which installed the light-scattering body 14 in the indoor ceiling is shown. When communication is performed using illumination light, communication quality deteriorates when shadows are formed. When the light scatterer 14 is installed on the ceiling in this way, it is difficult to make a shadow by a person or an object, so that the problem of shadowing can be avoided as much as possible.

  In the room A, an example in which a plurality of light scatterers 14 are installed is shown. By installing a plurality of light scatterers 14 in this way, it is possible to further reduce the influence of shadows. When a plurality of light scatterers 14 are installed in this way, modulated light can be sent from the same light source to the plurality of light scatterers 14 through the optical fiber 13. Therefore, it is not necessary to provide the light source control unit 11 and the light source for each lighting device, and the installation cost of the transmitter can be greatly reduced. Of course, it is also possible to transmit different information from the plurality of light scatterers 14, and in this case, it is possible to select information to be received by selecting illumination light received on the receiver 21 side. it can.

  Furthermore, the light scatterer 14 is similarly installed in the B room. At this time, the modulated light can be sent to the B chamber from the same light source as the A chamber. Therefore, the same information can be distributed even if the rooms are different. In this case, the light source control unit 11 can be shared even if the rooms are different, and further the light source 12 can be shared.

  In the first and second embodiments described above, it has been described that information is transmitted in one direction. However, since the optical fiber 13 conducts light in both directions, bidirectional communication is also possible. That is, the light emitted from the light source existing outside the light scatterer 14 is emitted from the end of the light source 12 through the optical fiber 13 from the light scatterer 14. By utilizing this, a light source existing outside the light scatterer 14 is driven and controlled to emit modulated light. This modulated light is emitted from the end of the light source 12 through the optical fiber 13. For example, a light separation means such as a half mirror is provided between the light source 12 and the end of the optical fiber 13, and the light emitted from the end of the optical fiber 13 on the light source 12 side is separated and received. The received information can be received. This enables bidirectional communication. Note that the amount of light incident on the optical fiber 13 through the light scatterer 14 becomes very weak due to the scattering of the light scatterer 14, but can be sufficiently realized by improving the light receiving sensitivity and the signal identification technique.

It is a conceptual diagram which shows the 1st Embodiment of this invention. It is a conceptual diagram which shows the modification in the 1st Embodiment of this invention. It is a conceptual diagram which shows the 2nd Embodiment of this invention. It is a schematic block diagram which shows the modification of the 2nd Embodiment of this invention. It is explanatory drawing of the example of application of this invention. It is explanatory drawing of an example of the illuminating device using the conventional optical fiber.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Light source, 2 ... Optical fiber, 11 ... Light source control part, 12 ... Light source, 13 ... Optical fiber, 14 ... Light scatterer, 15 ... Reflector, 16 ... Phosphor, 21 ... Receiver, 22 ... Light receiving part, 23: Demodulator.

Claims (5)

  An optical fiber that conducts light emitted from a light source, and a substantially hemispherical light scatterer that is provided at an end of the optical fiber and scatters and emits light that has conducted through the optical fiber. Light guide.   The light guide according to claim 1, wherein the optical fiber and the light scatterer are made of a plastic material.   The light guide according to claim 1, wherein the optical fiber and the light scatterer are integrated.   The light guide according to any one of claims 1 to 3, wherein a phosphor is mixed in the light scatterer.   5. The guide according to claim 1, wherein a reflection portion having a mirror surface as a surface facing the light scatterer is provided on the planar portion of the light scatterer. Light body.

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