Abstract: An LED is used as a light source of the emergency light. Data are normally received through a power line, demodulated at a modem section, and stored in a data memory. In an emergency, a change sectio switches the power line to a battery, and LED emits light and functions as the emergency light. At this time, the data stored in the data memory is read and demodulated at a light modulation section, and used to control blinking of the LED and the light intensity. Thereby, the data can be transmitted by the light. In an emergency, information on an emergency exit, an escape route, etc. can be received, if a mobile terminal having a light-receiving section receives the light from the emergency light.

Abstract: An light source control unit controls the flashing of a light source and the light amount of a light source according to information to be transmitted. Thus, light, which is modulated according to the information to be transmitted, is emitted from the light source. The light emitted from the light source is made to enter an optical fiber to pass therethrough and enter a light-scattering body which scatters and radiates the modulated light incident from the optical fiber. The scattered light serves as illumination light as it is. Furthermore, if the illumination light is decoded by a decoding unit after being received by a photoreceptor unit of a receiving set, then information carried by the illumination light can be received.

Abstract: Information received from a wired network terminal on the wall face, or the like, is delivered as a light signal from a light transmitting/receiving section of a light communication unit. A lighting fixture is provided with a light transmitting/receiving section where light is received from the light communication unit in order to acquire information, and a light emitting element emits illumination light modulated according to that information. A terminal can acquire the information by receiving the illumination light at a light transmitting/receiving section. Since communication is performed from the light communication unit to the terminal by irradiating light into the space, a convenient illumination light communication system requiring no communication cable or laying work of optical fibers can be constructed.

Abstract: An LED is used as a light source of the emergency light. Data are normally received through a power line, demodulated at a modem section, and stored in a data memory. In an emergency, a change sectio switches the power line to a battery, and LED emits light and functions as the emergency light. At this time, the data stored in the data memory is read and demodulated at a light modulation section, and used to control blinking of the LED and the light intensity. Thereby, the data can be transmitted by the light. In an emergency, information on an emergency exit, an escape route, etc. can be received, if a mobile terminal having a light-receiving section receives the light from the emergency light.

Abstract: In the case of performing communication by using illumination light when the illumination is on, switches are turned on, a signal modulated in an optical modulation part in accordance with information is superposed to a power waveform for the illumination with a power distributor and the illumination 16 is driven in a modulated state. When the illumination is off, the switches are turned off, a switch is turned on and a communication part is driven in a modulated state by the optical modulation part. The communication part can be constituted so as to include an infrared light emitting element part to perform infrared communication when the illumination is off. Consequently communication can be performed not only when the of illumination is on but also when the lighting is kept off. The communication device can be constituted of one element integrating the illumination part and the communication part, so that a compact system can be constituted.

Abstract: The illuminating end communication device is equipped with an illuminating light source. An electric power fed to the light source is modulated with a modulating unit responding to transmission data, and the modulated light is sent out as illuminating light. The illumination light is received by the light receiving unit of a terminal end communication device to maintain a downlink. Light emitted from the light emitting unit of the terminal end communication device is received by the light receiving unit of the illuminating end communication device to keep an uplink. Or, illuminating light is modulated on the basis of data when it is reflected, whereby data can be transmitted to the illuminating end communication device. It is preferable that illuminating light is reflected by CCR. A high-quality communication is realized using illuminating light of high power.

Abstract: The present invention has been developed considering the above-described problems and aims to provide various structures and applications for illuminative light communication. According to the first aspect of the prevent invention, a broadcast system includes an LED light source 115 for lighting, a power line 103 that supplies electric power to the LED light source 115, a data modulator 102 that modulates and multiplexes a plurality of pieces of data, superimposes the resulting signal on an electric power waveform, and then transmits the resulting superimposed signal waveform to the power line 103, and a filter 112 that selectively separates one or more of a plurality of pieces of modulated data on the power line so as to control light intensity or blinking of the LED light source. Data is transmitted through changes in light intensity or blinking of the LED light source.

Abstract: A data communication system capable of controlling the brightness of light sensed by the human eye and quality communication using an illuminative light is provided. A PWM circuit 11 adjusts pulse width in conformity with a light intensity control signal corresponding to a desired light intensity, resulting in a PWM signal. The PWM signal is then transmitted to a phase inverter 12. The phase inverter 12 outputs the PWM signal as is when a data signal to be transmitted is 0, for example, while it inverts the phase of the PWM signal and then outputs the resulting inverted PWM signal when the data signal is 1. A light source driver circuit 13 drives, a light source 14 such as an LED, organic electroluminescence, or the like in conformity with the phase inverted signal to emit light. In a data reception unit 2, an optical sensor 21 converts light emitted from an illuminating device 1 to an electric signal. A phase detection circuit 22 detects the phase of the signal and then outputs a received data signal.

Abstract: The present invention provides a power supply for a semiconductor light emitting device capable of efficiently modulating and driving a current-driven semiconductor light emitting device. An LED 31, a switching element 32, which modulates and drives the LED 31, and an average current detector 12, which detects an average current flowing through the LED 31, are connected to a voltage source 11. When the LED 31 is modulated and driven by the switching element 32, blinking or light quantity of the LED is controlled, and the LED 31 then emits modulated light. The average current detector 12 detects an average light quantity emitted from the LED 31 and then controls the voltage source to output a voltage so that the average current flowing through the LED 31 can be almost constant. As a result, the average light quantity may be kept almost constant with or without modulation of the LED 31.

Abstract: Near-distance interconnection of cellular phone terminals, which can easily correct axis misalignment. In two cellular phone terminals (130, 140), a visible light receiver (131) and a visible light emitter (132), and a visible light receiver (141) and a visible light emitter (142) are respectively provided side by side and oriented in the same direction. The visible light emitter (132) and the visible light receiver (141) face each other, and the visible light emitter (142) and the visible light receiver (131) also face each other, allowing visible light communication between near-distant cellular phones. Since the users can see the visible light used for communication, they can check whether the two terminals are coupled without axis misalignment. The visible light receivers (131, 141) can emit sufficiently strong visible light, using lasers or super luminescent diodes (SLDs), which can generate visible light modulated by data.

Abstract: The objective of the present invention is to provide accurate position data of a cellular phone utilizing illuminative light based radio communication. In FIG. 1, an emergency light or guided light (illuminating device) (10) on for 24 hours, for example, emits a visible light (illuminative light) modulated based on information of its position. A cellular phone (20) having a visible light receiving unit (a camera, for example) may obtain position data by receiving and demodulating that visible light. When conducting emergency communication (emergency telephone number 110 or 119) with the obtained position data, the position data may be automatically added for data communication in addition to the information by voice.

Abstract: A communications system implementing high-speed, high-quality communication in an oblong communication range such as mobile communication, and a leaky optical fiber preferably used in such communications system are provided. An optical fiber (2) is a GI-type optical fiber having a core structured such that the refractive index at the center is large, gradually decreasing as it approaches the periphery, and may have scatterers mixed therein. When modulated light enters the optical fiber (2) from a transmitter (1), the modulated light proceeds through the optical fiber (2) while a part of the light leaks from the side thereof. A receiver (3) receives this leaked light, and demodulates it so as to obtain data. Since the optical fiber (2) is a GI type, high-speed, high-quality mobile communication is possible with little waveform deformation.

Abstract: The present invention provides a camera-equipped cellular terminal capable of receiving visible light communication. In order to receive information from visible light, a light receiving unit (24) for visible light pointing to the same direction as a light receiving lens of the camera (21) is provided other than a camera (21) of a conventional camera-equipped cellular terminal (20). This light receiving unit (24) receives information from the visible light. This light receiving unit (24) may be configured by a photodiode or the like. When the camera (21) is used as a finder to display an illuminating device conducting visible light communication in a display of the camera, whether the light receiving unit 24 can receive information through visible light communication is determined.