IP Library › Granted Patent US 8,022,406
Granted Patent B2
US 8,022,406 · App. 12/358,843 · Granted Sep 20, 2011

Light emitting device

Assignee: Semiconductor Energy Laboratory Co., Ltd.
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Quick Facts
Patent No.
US 8,022,406
App. No.
12/358,843
Granted
Sep 20, 2011
Kind
B2
Abstract

While suppressing the frequency of a signal line driver circuit, a blur of a moving image of a light-emitting device using a light-emitting transistor can be prevented, without reducing a frame frequency. A switching element is provided in a path of a current which flows between a source and a drain of a light-emitting transistor, and the light-emitting transistor is made not to emit light by turning off the switching element, whereby pseudo-impulse driving is performed. Switching of the switching element can be controlled by a scan line driver circuit. In a specific structural example, the light-emitting device includes, in a pixel, a light-emitting transistor, a first switching element which controls supply of a potential of a video signal to a gate of the light-emitting transistor, and a second switching element which controls a current which flows between a source and a drain of the light-emitting transistor.

Claims (22)

1. A light-emitting device comprising: a pixel including a light-emitting transistor, a first switching element and a second switching element; wherein the light-emitting transistor, the first switching element, and the second switching element are within the pixel; and wherein the first switching element is configured to control supply of a video signal to a gate of the light-emitting transistor; and wherein the second switching element is configured to control a current flowing between a source and a drain of the light-emitting transistor.

2. The light-emitting device according to claim 1 , further comprising a signal line and a power supply line;

wherein the pixel includes both the signal line and the power supply line;

wherein the signal line is configured to supply the video signal to the light-emitting transistor through the first switching element; and

wherein the power supply line is configured to supply the current to the light-emitting transistor.

3. The light-emitting device according to claim 1 , further comprising a signal line and a power supply line;

wherein the pixel includes both the signal line and the power supply line;

wherein the signal line is electrically connected to the first switching element;

wherein the first switching element is electrically connected to the gate of the light-emitting transistor;

wherein the second switching element is electrically connected to one of the source and the drain of the light-emitting transistor; and

wherein the power supply line is electrically connected to the second switching element or the other of the source and the drain of the light-emitting transistor.

4. A light-emitting device comprising: a pixel including a light-emitting transistor, a first switching element and a second switching element; wherein the light-emitting transistor, the first switching element, and the second switching element are within the pixel; and wherein the first switching element is configured to control supply of a video signal to a gate of the light-emitting transistor; and wherein the second switching element is configured to control electrical connection between the gate and a source of the light-emitting transistor.

5. The light-emitting device according to claim 4 , further comprising a signal line and a power supply line;

wherein the pixel includes both the signal line and the power supply line;

wherein the signal line is configured to supply the video signal to the light-emitting transistor through the first switching element; and

wherein the power supply line is configured to supply a current to the light-emitting transistor.

6. The light-emitting device according to claim 4 , further comprising a signal line and a power supply line;

wherein the pixel includes both the signal line and the power supply line;

wherein the signal line is electrically connected to the first switching element;

wherein the first switching element is electrically connected to the gate of the light-emitting transistor;

wherein the second switching element is electrically connected to the source of the light-emitting transistor; and

wherein the power supply line is electrically connected to the second switching element or a drain of the light-emitting transistor.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 23, 2009
From: HONDA, TATSUYA
To: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
Reel/Frame 022149/0238 →
Priority Claims (1)
JP 2008-017188 · Jan 29, 2008 · national
Continuity (1)
Related Publication 20090189161A1 · Jul 30, 2009