In the case where processing is implemented in a medium mode, by interconnecting connectors 10 and 28, processing of information to be displayed on a memory type display panel 2 is implemented by a host display processing device 21; in the case where processing is implemented in a stand-alone mode, by disconnecting the connectors 10 and 28 from each other, processing of information to be displayed on the memory type display panel 2 is implemented by an information display sheet 1 itself.