Electronic device, display device, and semiconductor device and method for driving the same

A semiconductor device comprising:

• a first transistor;
• a first storage capacitor;
• a second storage capacitor;
• a first switch;
• a second switch;
• a third switch;
• a fourth switch;
• and
• a fifth switch,
• wherein one of a source and a drain of the first transistor is directly connected to a first electrode of a light-emitting element,
• wherein the one of the source and the drain of the first transistor is electrically connected to a gate of the first transistor through the second storage capacitor,
• wherein the other of the source and the drain of the first transistor is electrically connected to a first wiring through the second switch,
• wherein the other of the source and the drain of the first transistor is electrically connected to the gate of the first transistor through the third switch,
• wherein the other of the source and the drain of the first transistor is directly connected to the second switch and the third switch,
• wherein the gate of the first transistor is electrically connected to a second wiring through the first storage capacitor and the fourth switch,
• wherein the gate of the first transistor is electrically connected to a third wiring through the first storage capacitor and the first switch,
• wherein the one of the source and the drain of the first transistor is electrically connected to a fourth wiring through the fifth switch, and
• wherein a potential of the fourth wiring is lower than a potential of a second electrode of the light-emitting element.

A semiconductor device comprising:

• a transistor;
• a first storage capacitor;
• a load;
• a second storage capacitor configured to hold a gate-source voltage of the transistor;
• a first switch electrically connected between an electrode of the first storage capacitor and a second wiring;
• and
• a second switch electrically connected between a first electrode of the transistor and a first wiring,
• wherein a circuit is configured such that:
• when the first switch is turned off and the second switch is turned on, a first voltage is held in the first storage capacitor and a second voltage is held in the second storage capacitor,
• when the first switch is in a non-conducting state and the second switch is turned off, the second storage capacitor is discharged so that a voltage of the second storage capacitor changes from the second voltage to a threshold voltage of the transistor,
• when the first switch is turned on and the second switch is in a non-conducting state, which occurs after the first switch is in a non-conducting state and the second switch is turned off, a potential in accordance with a video signal is input to the first storage capacitor from the second wiring, and
• when the first switch is turned off and the second switch is turned on, a current which is set by the transistor is supplied to the load from the first wiring.

A method for driving a semiconductor device that comprises:

• a transistor;
• a first storage capacitor wherein a second electrode of the first storage capacitor is electrically connected to a gate of the transistor;
• a load electrically connected to a source of the transistor;
• a second storage capacitor configured to hold a gate-source voltage of the transistor;
• a first switch electrically connected between a first electrode of the first storage capacitor and a second wiring;
• a second switch, a first terminal of the second switch being electrically connected to a drain of the transistor and a second terminal of the second switch being electrically connected to a first wiring, and
• a third switch electrically connected between the source of the transistor and a fourth wiring, comprising the steps of:
• holding a first voltage in the first storage capacitor and a second voltage in the second storage capacitor while the third switch is in a conducting state in a first period;
• discharging the second storage capacitor so that a voltage between the first electrode and the second electrode of the second storage capacitor changes from the second voltage to a third voltage which corresponds to a threshold voltage of the transistor while the first switch and the third switch are in a non-conducting state in a second period after the first period;
• supplying a video signal to the second wiring so that a fourth voltage in accordance with the video signal and the third voltage of the transistor are applied to the gate of the transistor in a third period after the second period;
• and
• supplying a current to the load through the transistor in accordance with at least the fourth voltage in a fourth period after the third period.