DRIVING METHOD OF AN ELECTRIC CIRCUIT

• US 20130241813A1
• Filed: 04/15/2013
• Published: 09/19/2013
• Est. Priority Date: 07/31/2000
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Tanaka, Yukio
• Granted Patent: US 9,153,187 B2
• Time in Patent Office: Days
• US Class Current: 345/92
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3688 suitable for active matrices only
• CPC Class Codes: H03K 17/145 in field-effect transistor switches
• CPC Class Codes: H03K 17/687 the devices being field-effect transistors
• CPC Class Codes: H03K 17/6872 using complementary field-effect transistors
• CPC Class Codes: H03K 17/693 Switching arrangements with several input- or output-terminals, e.g. multiplexers, distributors logic circuits H03K19/00; code converters H03M5/00, H03M7/00

Abstract

A variation in threshold may be suppressed by structuring an analog switch by a MOS transistor and forming a signal synchronized to a clock by making the clock which is a common signal in continuity or discontinuity. An object of the present invention is to reduce the variation in the signal synchronized to the clock by the variation in threshold of the MOS transistor in a circuit which is synchronized to the clock.

Claims

1. (canceled)

2. An active matrix display device comprising:

a pixel portion formed over a substrate, and comprising a first TFT; and

a driver circuit formed over the substrate, and comprising a shift register comprising;

a flip-flop comprising a second TFT;

a first analog switch; and

a second analog switch;

wherein switching of the first analog switch and switching of the second analog switch are controlled depending on an output signal of the flip-flop, and

wherein a signal through the first analog switch is an output signal of the shift register.

3. An active matrix display device according to claim 2,

wherein a first signal is output from a first output terminal of the flip-flop,

wherein a second signal is output from a second output terminal of the flip-flop, and

wherein the first signal and the second signal are always output at an opposite logic level.

4. An active matrix display device according to claim 3, wherein the flip-flop produces the first and second signals in response to one or more video signals.

5. An active matrix display device according to claim 2, wherein the first analog switch and the second analog switch comprise a MOS transistor or a MIS transistor.

6. An active matrix display device according to claim 3,

wherein a first control terminal of the first analog switch is electrically directly connected to the first output terminal,

wherein a second control terminal of the second analog switch is electrically directly connected to the second output terminal.

7. An active matrix display device according to claim 2, wherein the flip-flop comprises a first inverter, a second inverter, a first NAND and a second NAND.

8. An active matrix display device comprising:

a pixel portion formed over a substrate, and comprising a first TFT; and

a driver circuit formed over the substrate, and comprising a shift register comprising;

a flip-flop comprising a second TFT;

a first analog switch; and

a second analog switch;

wherein switching of the first analog switch and switching of the second analog switch are controlled depending on an output signal of the flip-flop,

wherein a signal through the first analog switch is an output signal of the shift register, and

wherein the first analog switch and the second analog switch comprise transistors having a same conductivity.

9. An active matrix display device according to claim 8,

wherein a first signal is output from a first output terminal of the flip-flop,

wherein a second signal is output from a second output terminal of the flip-flop, and

wherein the first signal and the second signal are always output at an opposite logic level.

10. An active matrix display device according to claim 9, wherein the flip-flop produces the first and second signals in response to one or more video signals.

11. An active matrix display device according to claim 8, wherein the first analog switch and the second analog switch comprise a MOS transistor or a MIS transistor.

12. An active matrix display device according to claim 9,

wherein a first control terminal of the first analog switch is electrically directly connected to the first output terminal,

wherein a second control terminal of the second analog switch is electrically directly connected to the second output terminal.

13. An active matrix display device according to claim 8, wherein the flip-flop comprises a first inverter, a second inverter, a first NAND and a second NAND.