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US 6,714,183 B2Granted
Semiconductor display device and driving circuit therefor
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsShunpei Yamazaki, Jun Koyama
Life of this patent
Estimating the term…
Abstract
A semiconductor display device with low power consumption, low electromagnetic noise, and low unwanted radiation is provided. In a peripheral driving circuit, a clock signal with a voltage level increased by a level shifter circuit is input to a shift register circuit. Then a timing signal from the shift register circuit is input to a level shifter circuit, and the voltage level is thus raised in two stages.
Claims26
A method of operating a semiconductor device comprising:
- increasing a voltage of a signal which is input to a first level shifter circuit, to a voltage amplitude level at which it is sufficient for a shift register circuit to operate, and inputting increased signal to the shift register circuit;
- creating a timing signal by the shift register circuit, based on the input signal from the first level shifter, and inputting the timing signal to a second level shifter circuit;
- increasing a voltage amplitude level of the timing signal by the second level shifter circuit, and inputting the timing signal to a sampling circuit;
- and
- sampling image signals in accordance with the timing signal by the sampling circuit, and supplying sampled signals to source signal lines.
2 more elements
A method of operating a semiconductor device comprising:
- increasing a voltage of a clock signal which is input to a first level shifter circuit, to a voltage amplitude level at which it is sufficient for a shift register circuit to operate, and inputting increased signal to the shift register circuit;
- creating a timing signal by the shift register circuit, based on the signal from the first level shifter, and inputting the timing signal to a second level shifter circuit;
- increasing a voltage amplitude level of the timing signal to a certain fixed margin voltage in addition to a saturation voltage of a liquid crystal by the second level shifter circuit, and inputting the timing signal to a sampling circuit;
- and
- sampling image signals in accordance with the timing signal from the second level shifter by the sampling circuit, and supplying sampled signals to source signal.
2 more elements
A method of operating a semiconductor device comprising:
- increasing a voltage of a signal which is input to a first level shifter circuit, to a voltage amplitude level at which it is sufficient for a shift register circuit to operate, and inputting increased signal to the shift register circuit;
- creating a selection signal by the shift register circuit, based on the signal from the first level shifter, and inputting the selection signal to a second level shifter circuit;
- and
- increasing a voltage amplitude level of the selection signal by the second level shifter circuit to a voltage amplitude level at which it is sufficient for all pixel TFTs to operate, and supplying the increased selection signal to gate signal lines.
1 more element
A method of operating a semiconductor device comprising:
- increasing a voltage of a clock signal which is input to a first level shifter circuit, to a voltage amplitude level at which it is sufficient for a shift register circuit to operate, and inputting increased signal to the shift register circuit;
- creating a selection signal by the shift register circuit, based on the signal from the first level shifter, and inputting the selection signal to a second level shifter circuit;
- and
- increasing a voltage amplitude level of the selection signal by the second level shifter circuit to a voltage amplitude level at which it is sufficient for all pixel TFTs to operate, and supplying the increased selection signal to gate signal lines.
1 more element
A semiconductor device comprising at least one pixel region and driving circuits, at least one of driving circuits comprising:
- a source signal line driving circuit comprising a first level shifter circuit, a second level shifter circuit, a shift register circuit, and a sampling circuit,
- wherein the first level shifter circuit increases a voltage of an input signal, which is input to the first level shifter circuit, to a voltage amplitude level at which it is sufficient for the shift register circuit to operate, and inputs a signal to the shift register circuit,
- wherein the shift register circuit creates a timing signal, based on the input signal input from the first level shifter circuit, and inputs the timing signal to the second level shifter circuit,
- wherein the second level shifter circuit increases a voltage amplitude level of the timing signal, and inputs increased timing signal to the sampling circuit,
- wherein the sampling circuit samples an image signal in accordance with input timing signal, and supplies a signal to source signal lines connected to the source signal line driving circuit, and
- wherein the driving circuits comprise a plurality of thin film transistors, each thin film transistor comprising at least one semiconductor island, and at least one gate electrode adjacent to the semiconductor island with a gate insulating film interposed therebetween.
3 more elements
A semiconductor device comprising at least one pixel region and driving circuits, at least one of driving circuits comprising:
- a gate signal line driving circuit comprising a first level shifter circuit, a second level shifter circuit, and a shift register circuit,
- wherein the first level shifter circuit increases a voltage of an input signal, which is input to a voltage amplitude level at which it is sufficient for the shift register circuit to operate, and inputs a signal to the shift register circuit,
- wherein the shift register circuit creates a selection signal, based on the input signal from the first level shifter circuit, and inputs the selection signal to the second level shifter circuit,
- wherein the second level shifter circuit increases a voltage amplitude level of the input selection signal, to a voltage amplitude level at which it is sufficient for all pixel TFTs connected to gate signal lines to operate, and supplies the increased selection signal to the gate signal lines, and
- wherein the driving circuits comprise a plurality of thin film transistors, each thin film transistor comprising at least one semiconductor island, and at least one gate electrode adjacent to the semiconductor island with a gate insulating film interposed therebetween.
2 more elements
Dependencies are inferred from the claim text.