A keyboard for a mobile communication device includes a first set of alphanumeric keys that is arranged in a two column by three row array. It is basically constituted by a first stopper member and a second stopper member, which are normally separated from each other and which are respectively attached to a prescribed part of the keyboard instrument and a backend portion of the fall board at a prescribed position. This eliminates the need for bonding adhesive. Based on the profile selection, a set of instructions is retrieved from the profile memory. Two ends of the pivot are connected with the host and the display monitor respectively. An image compression unit performs a compression encoding of the image data based on a result of the determination of the document type judgment unit.