Illuminating light communication device

Abstract

An illuminating light communication device is provided to construct a communication system in which, when data are transmitted by using an electric power line and illuminating light, light intensity fluctuations of the illuminating light are suppressed and communication by means of the electric power line and the illuminating light can be well carried out. When data to be transmitted are sent through an electric power line, signal components are extracted in a filter (12), they are demodulated in an electric power line modulating unit (13), so that data are obtained. The obtained data are tentatively stored in a protocol converting unit (14). The data are then converted to an optical communication protocol, a semiconductor light emitting element (16) is turned on or off, or its light quantity is controlled to modulate illuminating light in accordance with data to be transmitted by a light source controller (15). Thus, the data are transmitted by making use of the illuminating light. As a modulation system for the light communication, multiple-value PPM may be used, wherein an existing pulse is set to OFF while a non-existing pulse is set to ON.

Description

technical field [0001] The present invention relates to a communication service for transmitting data using power lines and illuminating light (visible light). Background technique [0002] In recent years, semiconductor light emitting elements such as LEDs have been used as light sources for lighting. A semiconductor light-emitting element can perform high-speed blinking or light quantity control. Using this characteristic, a technology has been developed that transmits data using illumination light by flickering or controlling light intensity of semiconductor light emitting elements for illumination according to data. If the flickering of the semiconductor light-emitting element or the change in the light quantity is fast, the flickering or the change in the light quantity cannot be detected by human eyes. Therefore, it is possible to transmit data without hindering its use as illumination light for human beings. In addition, lighting devices are well-known devices, and...

AI Technical Summary

Problems solved by technology

However, when using illumination light for communication, although broadband communication can be performed in data transmission (downlink) from the illumination light communication device to each terminal, data transmission from each terminal (uplink) ) usually uses infrared communication, and the transmission speed is lower than that of the uplink

In this way, in communication using illuminating light, the communication speed is often asymmetrical, and from this point of view, it is problematic to still perform power line communication and illuminating light communication with the same protocol

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