US 7,352,133 B2 · Light emitting device

Abstract

An object of the present invention is to provide a light emitting device that is able to suppress power consumption while a balance of white light is kept, without making a configuration of a power source circuit complicated. A power source potential corresponding to each color of a light emitting element is used as a higher electric potential of a video signal and an electric potential of a power source line in the case that a transistor for controlling a supply of electric current to the light emitting element is a p-channel TFT. Conversely, a power source potential corresponding to each color of a light emitting element is used as a lower electric potential of a video signal and an electric potential of a power source line in the case that a transistor for controlling a supply of electric current to the light emitting element is an n-channel TFT.

Claims21

Dependent claims

An active matrix light emitting device comprising:

a pixel portion in which a light emitting element is provided in a pixel, the pixel portion comprising:
a source line;
a power source line;
a gate line;
and
a first TFT having a first gate electrode, a first source region and a first drain region;
a second TFT having a second gate electrode, a second source region and a second drain region;
a gate line driving circuit connected to the gate line;
and
a source line driving circuit connected to the source line,
wherein the first gate electrode is connected to the gate line,
wherein one of the first source region and the first drain region is connected to the source line,
wherein the other of the first source region and the first drain region is connected to the second gate electrode,
wherein one of the second source region and the second drain region is connected to the power source line,
wherein the other of the second source region and the second drain region is connected to the light emitting element, and
wherein an electric potential of the power source line is the same as one of a higher electric potential and a lower electric potential of a video signal when the second TFT is turned off.

13 more elements

An active matrix light emitting device comprising:

a pixel portion in which a light emitting element is provided in a pixel, the pixel portion comprising:
a source line;
a power source line;
a gate line;
and
a first TFT having a first gate electrode, a first source region and a first drain region;
a second TFT having a second gate electrode, a second source region and a second drain region;
a gate line driving circuit connected to the gate line;
and
a source line driving circuit connected to the source line,
wherein the first gate electrode is connected to the gate line,
wherein one of the first source region and the first drain region is connected to the source line,
wherein the other of the first source region and the first drain region is connected to the second gate electrode,
wherein one of the second source region and the second drain region is connected to the power source line,
wherein the other of the second source region and the second drain region is connected to the light emitting element,
wherein an electric potential of the power source line is the same as one of a higher electric potential and a lower electric potential of a video signal when the second TFT is turned off, and
wherein the electric potential of the power source line is different in accordance with a corresponding color of the light emitting element.

14 more elements

Dependencies are inferred from the claim text.

Light emitting device

Life of this patent

Light emitting device

Life of this patent

Abstract

Claims21