Portable device settable in a host apparatus and combined system therefor

摘要

An image transmission system utilizing a portable device includes a light-receiving unit, a unit for generating image data on the basis of an output from the light-receiving unit, and a unit for transmitting the image data generated by the generating unit. The portable device includes a light-emitting unit, and a control unit for causing the light-emitting unit to emit light in accordance with call data and image data.