Display device

A display device having a driving circuit and a pixel portion,

• wherein the driving circuit has a first scanning circuit and a second scanning circuit,
• wherein the first scanning circuit has first to x-th stages of units (x stages in total, x is a natural number and satisfies x≧2),
• wherein the x stages of units each have a shift register, a level shifter, and a constant current source, the shift register sequentially outputting pulses in response to a first clock signal, the level shifter converting the voltage amplitude of a signal inputted, the constant current source supplying a current to the level shifter,
• wherein the second scanning circuit has a shift register for sequentially outputting pulses in response to a second clock signal, and
• wherein the constant current source in the a-th stage unit (a is a natural number and satisfies 1≦a≦x) supplies a current only while the pulses sequentially outputted from the second scanning circuit are inputted to the constant current source in the a-th stage unit.

A display device having a driving circuit and a pixel portion,

• wherein the driving circuit has a scanning circuit and a selecting circuit,
• wherein the scanning circuit has a shift register, a level shifter, and a constant current source, the shift register sequentially outputting pulses in response to a clock signal, the level shifter converting the voltage amplitude of a signal inputted, the constant current source supplying a current to the level shifter,
• wherein the selecting circuit has a decoder that outputs a selecting pulse to an arbitrary terminal out of a plurality of output terminals upon input of a selecting signal, and
• wherein the constant current source supplies a current only while the selecting pulse is inputted from the decoder to the constant current source.

A display device having a driving circuit and a pixel portion,

• wherein the driving circuit has a scanning circuit and a selecting circuit,
• wherein the scanning circuit has first to x-th stages of units (x stages in total, x is a natural number and satisfies x≧2),
• wherein the x stages of units each have a shift register, a level shifter, and a constant current source, the shift register sequentially outputting pulses in response to a clock signal, the level shifter converting the voltage amplitude of a signal inputted, the constant current source supplying a current to the level shifter,
• wherein the selecting circuit has a decoder that outputs a selecting pulse to an arbitrary terminal out of a plurality of output terminals upon input of a selecting signal,
• wherein each of the plural output terminals of the decoder is connected to the constant current source in one of the units, with no two terminals being connected to the constant current source in the unit of the same stage, and
• wherein the constant current source in the a-th stage unit (a is a natural number and satisfies 1≦a≦x) supplies a current only while the selecting pulse is inputted from the decoder to the constant current source in the a-th stage unit.

A display device having a driving circuit and a pixel portion,

• wherein the driving circuit has a scanning circuit and a selecting circuit,
• wherein the scanning circuit has first to x-th stages of units (x stages in total, x is a natural number and satisfies x≧2),
• wherein the x stages of units each have a shift register, a level shifter, a constant current source, and a constant current source switch circuit, the shift register sequentially outputting pulses in response to a clock signal, the level shifter converting the voltage amplitude of a signal inputted, the constant current source supplying a current to the level shifter, the constant current source switch circuit inputting a pulse to the constant current source to control a current supply period and a current stop period,
• wherein the selecting circuit has a decoder that outputs a selecting pulse to an arbitrary terminal out of a plurality of output terminals upon input of a selecting signal,
• wherein the constant current source switch circuit in the a-th stage unit (a is a natural number and satisfies 1≦a≦x) outputs a pulse to the constant current source in the a-th stage unit only while one of selecting pulses outputted from the decoder is inputted or an output pulse from the last stage shift register in the (a−1)-th unit is inputted, and
• wherein the constant current source in the a-th stage unit supplies a current only while a pulse is inputted from the constant current source switch circuit in the a-th stage unit.

A display device comprising:

• a plurality of gate lines extending in parallel over a substrate;
• a plurality of signal lines extending across the plurality of the gate lines;
• a plurality of switching elements provided at each intersection of the plurality of gate lines and the plurality of signal lines;
• a driving circuit for supplying signals to the plurality of signal lines, the driving circuit comprising a plurality of unit circuits, each comprising a plurality of shift registers and a level shifter circuit,
• wherein each of the unit circuits is connected to at least two of the plurality of signal lines.

A display device comprising:

• a plurality of gate lines extending in parallel over a substrate;
• a plurality of signal lines extending across the plurality of the gate lines;
• a plurality of switching elements provided at each intersection of the plurality of gate lines and the plurality of signal lines;
• a driving circuit for supplying signals to the plurality of signal lines, the driving circuit comprising:
• a first scanning circuit comprising a plurality of unit circuits, each comprising a plurality of first shift registers, a level shifter circuit operationally connected to the plurality of first shift registers;
• and
• a second scanning circuit comprising a plurality of second shift registers, each connected to corresponding one of the plurality of unit circuits,
• wherein each of the unit circuits is connected to at least two of the plurality of signal lines.

A display device comprising:

• a plurality of gate lines extending in parallel over a substrate;
• a plurality of signal lines extending across the plurality of the gate lines;
• a plurality of switching elements provided at each intersection of the plurality of gate lines and the plurality of signal lines;
• a driving circuit for supplying signals to the plurality of signal lines, the driving circuit comprising:
• a first scanning circuit comprising a plurality of unit circuits, each comprising a plurality of first shift registers, a level shifter circuit operationally connected to the plurality of first shift registers and a current constant source operationally connected to the level shifter circuit and corresponding one of a plurality of second shift registers;
• and
• a second scanning circuit comprising the plurality of second shift registers;
• wherein each of the plurality of unit circuits connected to at least two of the plurality of source signal lines.