Level shifter

A level shifter comprising:

• a first MOS transistor of a first conductive type having a source connected to a first power source, and a gate to which a first input signal is inputted;
• a second MOS transistor of a same conductive type as said first conductive type, having a source connected to said first power source, and a gate to which a second input signal is inputted, wherein said second input signal is an inverted signal of said first input signal;
• a third MOS transistor of a second conductive type different from said first conductive type, having a drain connected to a drain of said first MOS transistor, and a gate connected to a drain of said second MOS transistor:
• a fourth MOS transistor of a same conductive type as said second conductive type, having a drain connected to a drain of said second MOS transistor, and a gate connected to a drain of said first MOS transistor;
• a first voltage regulating circuit connected between a source of said third MOS transistor and a second power source;
• and
• a second voltage regulating circuit connected between a source of said fourth MOS transistor and said second power source,
• wherein said first and second input signals of a first voltage amplitude is converted to a signal of a second voltage amplitude to thereby output a signal from at least one of said drains of said first MOS transistor or said second MOS transistor.

An active matrix type display device comprising:

• a plurality of pixel thin film transistors over a substrate;
• and
• a driver circuit over said substrate for driving said pixel thin film transistors, said driver circuit comprising at least a level shifter,
• wherein said level shifter comprising:
• a first thin film transistor of a first conductive type having a source connected to a first power source, and a gate to which a first input signal is inputted;
• a second thin film transistor of a same conductive type as said first conductive type, having a source connected to said first power source, and a gate to which a second input signal is inputted, wherein said second input signal is an inverted signal of said first input signal;
• a third thin film transistor of a second conductive type different from said first conductive type, having a drain connected to a drain of said first thin film transistor, and a gate to which said first input signal is inputted;
• a fourth thin film transistor of a same conductive type as said second conductive type, having a drain connected to a drain of said second thin film transistor, and a gate to which said second input signal is inputted;
• a fifth thin film transistor of a same conductive type as said second conductive type, having a drain connected to a source of said third thin film transistor, and a gate connected to a drain of said second thin film transistor;
• a sixth thin film transistor of a same conductive type as said second conductive type, having a drain connected to a source of said fourth thin film transistor, and a gate connected to a drain of said first thin film transistor;
• a first voltage regulating circuit connected between a source of said fifth thin film transistor and a second power source;
• and
• a second voltage regulating circuit connected between a source of said sixth thin film transistor and said second power source,
• wherein said first and second input signals of a first voltage amplitude is converted to a signal of a second voltage amplitude to thereby output a signal from at least one of said drains of said first thin film transistor or said second thin film transistor.

An active matrix type display device comprising:

• a plurality of pixel thin film transistors over a substrate;
• and
• a driver circuit over said substrate for driving said pixel thin film transistors, said driver circuit comprising at least a level shifter,
• wherein said level shifter comprising:
• a first thin film transistor of a first conductive type having a source connected to a first power source, and a gate to which a first input signal is inputted;
• a second thin film transistor of a same conductive type as said first conductive type, having a source connected to said first power source, and a Gate to which a second input signal is inputted, wherein said second input signal is an inverted signal of said first input signal;
• a third thin film transistor of a second conductive type different from said first conductive type, having a drain connected to a drain of said first thin film transistor, and a gate connected to a drain of said second thin film transistor;
• a fourth thin film transistor of a same conductive type as said second conductive type, having a drain connected to a drain of said second thin film transistor, and a gate connected to a drain of said first thin film transistor:
• a first voltage regulating circuit connected between a source of said third thin film transistor and a second power source;
• and
• a second voltage regulating circuit connected between a source of said fourth thin film transistor and said second power source,
• wherein said first and second input signals of a first voltage amplitude is converted to a signal of a second voltage amplitude to thereby output a signal from at least one of said drains of said first thin film transistor or said second thin film transistor.