Abstract: An antenna includes: a case body having a bottom plate portion, side plate portions extending from the bottom plate portion, and an opening portion surrounded by the side plate portions; a magnetic resonance antenna portion placed in the case body; and a magnetic shield body disposed on a side closer to the opening portion than the magnetic resonance antenna portion.

Abstract: An electric power transmission system includes: a transmitting-side system that includes switching elements that convert a direct-current voltage to an alternating-current voltage and that output the alternating-current voltage and a transmitting-side magnetic resonance antenna unit that has a first inductor and a first capacitor directly coupled to each other and to which the output alternating-current voltage is input; and a receiving-side system that includes a second inductor and a second capacitor directly coupled to each other and that resonates with the transmitting-side magnetic resonance antenna unit via electromagnetic field to thereby receive electric energy output from the transmitting-side magnetic resonance antenna unit.

Abstract: An audio reproducer that can be preferably used to practice to play a musical instrument is disclosed. The audio reproducer includes an audio reproduction part and a processing part. The audio reproduction part reproduces a first audio signal recorded in a recording medium. The processing part performs a special reproduction operation on the reproduced first audio signal under control over the audio reproduction part as well as a special effect operation on a second audio signal supplied via an input terminal. Then the processing part synthesizes the resulting first audio signal and the resulting second audio signal to generate an output audio signal.