LIQUID CRYSTAL DISPLAY DEVICE
First Claim
1. A liquid crystal display device comprising:
- a first scan line and a second scan line arranged in parallel or substantially parallel to each other;
a first signal line and a second signal line arranged in parallel or substantially parallel to each other; and
a liquid crystal element surrounded by the first scan line, the second scan line, the first signal line, and the second signal line,wherein the first signal line intersects with the first scan line so that a first step is formed in the first signal line due to the first scan line,wherein the first signal line intersects with the second scan line so that a second step is formed in the first signal line due to the second scan line, andwherein the whole of an upper surface of the first signal line exists coplanarly or substantially coplanarly in a region which is interposed between the first step and the second step.
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Accused Products
Abstract
An object is to reduce parasitic capacitance of a signal line included in a liquid crystal display device. A transistor including an oxide semiconductor layer is used as a transistor provided in each pixel. Note that the oxide semiconductor layer is an oxide semiconductor layer which is highly purified by thoroughly removing impurities (hydrogen, water, or the like) which become electron suppliers (donors). Thus, the amount of leakage current (off-state current) can be reduced when the transistor is off. Therefore, a voltage applied to a liquid crystal element can be held without providing a capacitor in each pixel. In addition, a capacitor wiring extending to a pixel portion of the liquid crystal display device can be eliminated. Therefore, parasitic capacitance in a region where the signal line and the capacitor wiring intersect with each other can be eliminated.
110 Citations
21 Claims
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1. A liquid crystal display device comprising:
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a first scan line and a second scan line arranged in parallel or substantially parallel to each other; a first signal line and a second signal line arranged in parallel or substantially parallel to each other; and a liquid crystal element surrounded by the first scan line, the second scan line, the first signal line, and the second signal line, wherein the first signal line intersects with the first scan line so that a first step is formed in the first signal line due to the first scan line, wherein the first signal line intersects with the second scan line so that a second step is formed in the first signal line due to the second scan line, and wherein the whole of an upper surface of the first signal line exists coplanarly or substantially coplanarly in a region which is interposed between the first step and the second step. - View Dependent Claims (2, 3, 4, 5)
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6. A liquid crystal display device comprising:
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a first scan line and a second scan line arranged in parallel or substantially parallel to each other; a first signal line and a second signal line arranged in parallel or substantially parallel to each other; a liquid crystal element surrounded by the first scan line, the second scan line, the first signal line, and the second signal line; and a transistor including a gate, an insulating layer, a semiconductor layer, a source, and a drain, wherein the first signal line intersects with the first scan line so that a first step is formed in the first signal line due to the first scan line, wherein the first signal line intersects with the second scan line so that a second step is formed in the first signal line due to the second scan line, and wherein the whole of an upper surface of the first signal line exists coplanarly or substantially coplanarly in a region which is interposed between the first step and the second step. - View Dependent Claims (7, 8, 9, 10, 11, 12)
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13. A liquid crystal display device comprising a plurality of pixels, at least one of the plurality of pixels comprising:
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a scan line; a signal line; a transistor comprising a gate, a source, and a drain, wherein the gate is electrically connected to the scan line, and one of the source and the drain is electrically connected to the signal line; and a liquid crystal element electrically connected to the other of the source and the drain, wherein the signal line intersects with the scan line so that a step is formed in the signal line due to the scan line, and wherein the whole of an upper surface of the signal line exists coplanarly or substantially coplanarly in a region between the step and the step which is located in a neighboring pixel. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21)
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Specification