PURPOSE: To rapidly perform the display of pattern and the change of pattern and to accomplish flexible operation with small quantity of information by displaying a pattern stored in a fixed pattern storage part and a variable pattern storage part based on the command of pattern from a communication part.

CONSTITUTION: The pattern stored in the fixed pattern storage part 21 or the variable pattern storage part 22 is displayed on the display part 3 based on a pattern command signal given from the communication part 1. A selection circuit 4 selects one of the fixed patterns 1-m stored in the storage part 21 and the variable patterns 1-n stored in the storage part 22 based on the pattern command signal from the communication part 1. The fixed or variable pattern which is selected is displayed on the display part 3. Meanwhile, the patterns stored in the storage parts 21 and 22 can be rewritten based on a command signal from the communication part 1.