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US 7,403,038 B2Granted
Semiconductor device and display device
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorMunehiro Azami
Life of this patent
Estimating the term…
Abstract
A circuit capable of reducing a consumption current is provided for a digital display device composed of unipolar TFTs. There is provided a latch circuit for holding a digital video signal. According to the latch circuit, when the digital video signal is inputted to an input electrode of a TFT (101), a non-inverting output signal is outputted from an output electrode of the TFT (101) and an inverting output signal is outputted from output electrodes of TFTs (102 and 103). Two line outputs of non-inversion and inversion are obtained. Thus, when a buffer located in a subsequent stage is operated, a period for which a direct current path is produced between a high potential and a low potential of a power source can be shortened, thereby contributing to reduction in a consumption current.
Claims42
A method of driving a semiconductor device comprising the steps of:
- inputting a first signal to gate electrodes of first and second transistors;
- inputting a second signal to a gate electrode of a third transistor and a first signal output portion through input and output electrodes of the first transistor in accordance with the input of the first signal;
- outputting an inverting signal of the second signal output to a second signal output portion from output electrodes of the second and third transistors in accordance with the input of the first signal;
- wherein the first, second, and third transistors have the same conductivity type,
- wherein a first capacitor means is located to the first signal output portion and keeps a potential of a signal outputted from the first signal output portion, and
- wherein a second capacitor means is located to the second signal output portion and keeps a potential of a signal outputted from the second signal output portion.
3 more elements
A method of driving a semiconductor device comprising the steps of:
- inputting a first signal to a gate electrode of a first transistor and gate and input electrodes of a second transistor;
- inputting a second signal to a gate electrode of a third transistor and a first signal output portion through input and output electrodes of the first transistor in accordance with the input of the first signal;
- outputting an inverting signal of the second signal output to a second signal output portion from output electrodes of the second and third transistors in accordance with the input of the first signal;
- wherein the first, second, and third transistors have the same conductivity type,
- wherein a first capacitor means is located to the first signal output portion and keeps a potential of a signal outputted from the first signal output portion, and
- wherein a second capacitor means is located to the second signal output portion and keeps a potential of a signal outputted from the second signal output portion.
3 more elements
A method of driving a semiconductor device comprising the steps of:
- inputting a first signal to gate electrodes of first and second transistors;
- inputting a second signal to a gate electrode of a third transistor and an output electrode of the first transistor through an input electrode of the first transistor in accordance with the input of the first signal;
- inputting an inverting signal of the second signal to output electrodes of the second and third transistors in accordance with the input of the first signal;
- compensating and attenuating an amplitude of the signal produced in the output electrode of the first transistor, and outputting it to a first signal output portion by an amplitude compensation buffer circuit;
- and
- compensating and attenuating an amplitude of the signal produced in the output electrodes of the second and third transistors, and outputting it to a second signal output portion by the amplitude compensation buffer circuit,
- wherein the first, second, and third transistors have the same conductivity type,
- wherein a first capacitor means is located to the output electrode of the first transistor and keeps a potential of a signal outputted from the output electrode of the first transistor, and
- wherein a second capacitor means is located to the output electrodes of the second and third transistors and keeps a potential of a signal outputted from the output electrodes of the second and third transistors.
6 more elements
A method of driving a semiconductor device comprising the steps of:
- inputting a first signal to a gate electrode of first transistor and gate and input electrodes of second transistor;
- inputting a second signal to a gate electrode of a third transistor and an output electrode of the first transistor through an input electrode of the first transistor in accordance with the input of the first signal;
- inputting an inverting signal of the second signal to output electrodes of the second and third transistors in accordance with the input of the first signal;
- compensating and attenuating an amplitude of the signal produced in the output electrode of the first transistor, and outputting it to a first signal output portion by an amplitude compensation buffer circuit;
- and
- compensating and attenuating an amplitude of the signal produced in the output electrodes of the second and third transistors, and outputting it to a second signal output portion by the amplitude compensation buffer circuit,
- wherein the first, second, and third transistors have the same conductivity type,
- wherein a first capacitor means is located to the output electrode of the first transistor and keeps a potential of a signal outputted from the output electrode of the first transistor, and
- wherein a second capacitor means is located to the output electrodes of the second and third transistors and keeps a potential of a signal outputted from the output electrodes of the second and third transistors.
6 more elements
A method of driving a semiconductor device comprising the steps of:
- inputting a first signal to gate electrodes of first and second transistors;
- inputting a second signal to a gate electrode of a third transistor and an output electrode of the first transistor through an input electrode of the first transistor in accordance with the input of the first signal;
- inputting an inverting signal of the second signal to output electrodes of the second and third transistors in accordance with the input of the first signal;
- inputting the signal produced in the output electrode of the first transistor to gate electrodes of fourth and fifth transistors;
- inputting the signal produced in the output electrodes of the second and third transistors to gate electrodes of sixth and seventh transistors
- wherein the first to seventh transistors have the same conductivity type,
- a first capacitor means is located to the output electrode of the first transistor and keeps a potential of a signal outputted from the output electrode of the first transistor,
- a second capacitor means is located to the output electrodes of the second and third transistors and keeps a potential of a signal outputted from the output electrodes of the second and third transistors,
- a third capacitor means is located between the gate electrode and the output electrode of the fourth transistor to produce capacitive coupling, and
- a fourth capacitor means is located between the gate electrode and the output electrode of the seventh transistor to produce capacitive coupling.
7 more elements
A method of driving a semiconductor device comprising the steps of:
- inputting a first signal to a gate electrode of first transistor and gate and input electrodes of second transistor;
- inputting a second signal to a gate electrode of a third transistor and an output electrode of the first transistor through an input electrode of the first transistor in accordance with the input of the first signal;
- inputting an inverting signal of the second signal to output electrodes of the second and third transistors in accordance with the input of the first signal;
- inputting the signal produced in the output electrode of the first transistor to gate electrodes of fourth and fifth transistors;
- inputting the signal produced in the output electrodes of the second and third transistors to gate electrodes of sixth and seventh transistors
- wherein the first to seventh transistors have the same conductivity type,
- a first capacitor means is located to the output electrode of the first transistor and keeps a potential of a signal outputted from the output electrode of the first transistor,
- a second capacitor means is located to the output electrodes of the second and third transistors and keeps a potential of a signal outputted from the output electrodes of the second and third transistors,
- a third capacitor means is located between the gate electrode and the output electrode of the fourth transistor to produce capacitive coupling, and
- a fourth capacitor means is located between the gate electrode and the output electrode of the seventh transistor to produce capacitive coupling.
7 more elements
Dependencies are inferred from the claim text.