In a communication system of a subscriber extension line system, there is provided a communication controller whereby the load of an unnecessary process to be applied on a communication controller relating to a destination of a mobile telephone is eliminated and the processing efficiency for communication control is enhanced. The invention further relates to a plastic element producing machine and a method for the manufacture of a plastic element having a surface with a positive microstructure. Also, a line direction connecting the source and drain region of a thin film transistor is aligned to the line direction of the linear laser light.