Patent ID: 8416622
Filing Date: 2013-04-09
Classification: G11C

Abstract:
1. A driving method of a semiconductor device comprising the steps of: in a writing period, applying a first potential to a gate of a first transistor, turning on the first transistor, and accumulating a positive electric charge in a node through the first transistor, wherein the node electrically is connected to one of a source and a drain of the first transistor; in an inverted period following the writing period, applying a second potential to the gate of the first transistor, and turning off the first transistor, wherein the second potential is a negative potential; and in a retention period following the inverted period, applying a third potential to the gate of the first transistor, maintaining an off state of the first transistor, and retaining positive electric charge accumulated in the node, wherein the third potential is lower than the first potential and higher than the second potential, wherein a channel region of the first transistor is comprised in an oxide semiconductor layer.