A direct-injection internal combustion engine includes a variable-exhaust-valve control device for controlling value timing of a variable exhaust valve through which the combustion chamber of an engine cylinder communicates with an exhaust path. A video decoder is coupled to the input and decode the received encoded video sequence. The portable device contains an image capturing sensor, a text detection module, an OCR module, a storage device and means for presenting the output to the user or other devices. A plurality of conductors connect each electrode to a respective given one of the terminals. This prevents intermittent changes of the DI ratio, and thus, prevents variation in engine output.