An apparatus and method for applying digital pre-distortion technology in an electronic device which uses an envelope tracking method is provided. The printing system includes: a computer for preparing printing information, and a gateway server connected to the computer, which are provided to a printed matter preparer; and a printing apparatus having an allocated IP address, which is provided to a printed matter customer. The imaging device has an eye positioned adjacent to the open end of the body. Upon receipt of an impact vibration or an impact force at a predetermined magnitude or more, the tension of the cushioning member provided as the tension structure lowers to be able to exhibit high damping characteristics.