A music reproduction device for recommending music suitable for a taste of a user is provided. By providing optical circulators, dispersion compensators, and optical filters that reflect specified wavelengths and transmit wavelengths other than the specified wavelengths from among the outputs of the dispersion compensators, and causing specified wavelengths to make round trips of the dispersion compensators, the dispersion volume of the dispersion compensators is reduced. The identifier may be used to identify the type of peripheral attached to the gaming machine. In one embodiment, a protective layer covers micro-lenses of the image sensor devices to protect the lenses from being damaged or polluted by, for example, silicon dust during wafer sawing.