As a conventional art, there is an illumination light communication apparatus which performs communication using a light source, which emits visible light used for illumination and infrared light not used for illumination, while causes information, which is to be transmitted, to be included in the visible light and the infrared light. One example of such an illumination light communication apparatus is disclosed in Patent Document 1. FIG. 14 is a view showing a configuration of an illumination light communication apparatus 600 in the Patent Document 1. The following will briefly describe the operation of the illumination light communication apparatus 600 with reference to FIG. 14. First, in the case of performing communication using illumination light (visible light) when the illumination is on, the illumination light communication apparatus 600 causes switches 512 and 513 to be in the connection state. Then, a light modulation section 511 generates a signal obtained by modulating information which is to be transmitted. An electric power distributor 515 superimposes this signal on the waveform of electric power, which is used for performing illumination, and activates an illumination section 516. Thus, the illumination light communication apparatus 600 is capable of performing optical communication using visible light while causing the communication operation to be included in the illumination operation. On the other hand, in the case of performing communication when the illumination is off, the illumination light communication apparatus 600 causes the switches 512 and 513 to be in the disconnection state and a switch 514 to be in the connection state. Then, the light modulation section 511 activates a communication section 517 which emits infrared light. Thus, the illumination light communication apparatus 600 is capable of performing communication using infrared light even when the illumination is off.
As described above, the illumination light communication apparatus 600 is capable of not only performing communication when the illumination is on and but also performing communication while keeping the illumination off when the illumination is off. It is noted that because the illumination section 516 and the communication section 517 can be combined into one light-emitting element, a compact system configuration is possible.    [Patent Document 1] Japanese Patent Laid-open Publication No. 2004-282389