Scanning switch means 21 to 2m can connect scanning lines S1 to Sm freely
to a first potential or a second potential. Drive switch means 71 to 7n
can connect drive lines D1 to Dn freely to a drive current source 70 or
an off potential. Control means 8 connects the scanning switch means 21
to 2m sequentially with the first potential to select the scanning lines
S1 to Sm sequentially and to control the connected states of the drive
switch means 71 to 7n. In accordance with the number of the drive lines
D1 to Dn to be connected to the drive current source 70, the control
means 8 changes the resistances of the scanning switch means 21 to 2m
corresponding to the scanning lines S1 to Sm connected to the second
potential to become the unselected state, into at least two stages.