Shift register circuit, gate driver and display apparatus
Provided is a shift register circuit including a single conductive transistor which performs overlap scanning without increasing the number of clock signals and reduces power consumption by avoiding an ineffective through current, a gate driver, and a display apparatus. The shift register circuit includes: a shift register unit having a first output transistor which connects an output terminal and a first power supply; and a first gate control circuit of which an output terminal is connected to a gate terminal of the first output transistor, wherein the first gate control circuit includes a timing generation unit and a buffer unit, the buffer unit is a bootstrap circuit, and an output of the timing generation unit to which an input signal is inputted is used as an input of the buffer unit and an output of the buffer unit is used as an output of the first gate control circuit.
1. A shift register circuit including a single conductivity type transistor, comprising:
a shift register unit having a first output transistor which connects an output terminal and a first power supply; and
a first gate control circuit of which an output terminal is connected to a gate terminal of the first output transistor,
wherein the first gate control circuit includes a timing generation unit and a buffer unit,
wherein the buffer unit is a bootstrap circuit,
wherein an output of the timing generation unit to which an input signal is inputted is used as an input of the buffer unit and an output of the buffer unit is used as an output of the first gate control circuit, and
wherein the buffer unit is a bootstrap circuit including at least:
a second transistor which connects the output of the buffer unit and a first clock signal;
a third transistor which connects a gate terminal of the second transistor and an output of the timing generation unit and is gate-controlled by a second clock signal; and
a fourth transistor which connects the output of the buffer unit and the first power supply and is gate-controlled by the second clock signal.
2. The shift register circuit of claim 1 , wherein
the timing generation unit includes:
a fifth transistor which is gate-controlled by an input of the first gate control circuit and connects the first power supply and an input of the buffer unit; and
a first capacitor which connects the input of the buffer unit and the second clock signal.
3. The shift register circuit of claim 1 , wherein
the timing generation unit includes:
a sixth transistor which is gate-controlled by an input of the first gate control circuit and connects the first power supply and an input of the buffer unit; and
a seventh transistor which connects the input of the buffer unit and a second power supply and has a gate terminal connected to the second power supply.
4. The shift register circuit of claim 1 , wherein
the shift register unit includes:
an eighth output transistor having a source terminal connected to an output terminal of the shift register circuit and a drain terminal connected to a second power supply; and
a ninth transistor having a gate terminal to which the first clock signal is inputted, a drain terminal to which an additional input signal is inputted, and a source terminal connected to a gate terminal of the eighth output transistor.
5. The shift register circuit of claim 1 ,
wherein the shift register unit includes a tenth output transistor which connects the output terminal of the shift register circuit and the first power supply,
further comprising a second gate control circuit of which an output terminal is connected to a gate terminal of the tenth output transistor, and
wherein the second gate control circuit includes a timing generation unit and a buffer unit, and
wherein an output of the timing generation unit included in the second gate control circuit to which an input signal is inputted is used as an input of the buffer unit included in the second gate control circuit and an output of the buffer unit included in the second gate control circuit is used as an output of the second gate control circuit.
6. The shift register circuit of claim 1 ,
wherein the shift register unit includes a tenth output transistor which connects the output terminal of the shift register circuit and the first power supply,
further comprising a second gate control circuit of which an output terminal is connected to a gate terminal of the tenth output transistor, and
wherein the second gate control circuit includes a timing generation unit and a buffer unit, and
wherein an output of the timing generation unit included in the second gate control circuit to which an input signal is inputted is used as an input of the buffer unit included in the second gate control circuit and an output of the buffer unit included in the second gate control circuit is used as an output of the second gate control circuit.
7. The shift register circuit of claim 6 , wherein
the buffer unit included in the first gate control circuit is a bootstrap circuit configured to output the first clock signal, and the buffer unit included in the second gate control circuit is a bootstrap circuit configured to output the second clock signal.
8. A gate driver in which a plurality of stages of the shift register circuits of claim 5 are connected, wherein
an output of the shift register circuit of an (n−2)-th (n is an integer of 3 or more) stage is used as an input of the shift register unit and the first or second gate control circuit of an (n−1)-th stage, and
an output of the first or second gate control circuit of the (n−1)-th stage is used as an input of the shift register unit of the (n−1)-th stage and the shift register unit of the n-th stage.
9. The shift register circuit of claim 1 , wherein
the shift register circuit is a shift register circuit of an n-th (n is an integer of 3 or more) stage of a gate driver, and
the buffer unit of the first gate control circuit is a bootstrap circuit, which has at least a second output, and includes: an eleventh transistor which connects the second output of the buffer unit and the first power supply; a twelfth transistor which connects the second output of the buffer unit and the output of the buffer unit; and a thirteenth transistor which connects a gate terminal of the twelfth transistor and an output of the shift register circuit of an (n+2)-th stage, and in which the eleventh transistor is controlled by the second clock signal, and the thirteenth transistor is controlled by a second power supply.
10. A shift register circuit, comprising:
the first gate control circuit of claim 9 of which the second output is connected to the gate terminal of the first output transistor.
11. A gate driver in which a plurality of stages of the shift register circuits of claim 9 are connected, wherein
an output of the shift register circuit of an (n−2)-th stage is used as an input of the shift register unit and the first gate control circuit of an (n−1)-th stage,
an output of the shift register circuit of an (n+2)-th stage is used as an input of the first gate control circuit of the (n−1)-th stage,
a first output of the first gate control circuit of the (n−1)-th stage is used as an input of the shift register unit of the (n−1)-th stage and the shift register unit of the n-th stage, and
a second output of the first gate control circuit of the (n−1)-th stage is used as an input of the shift register unit of the n-th stage.
12. A matrix type display apparatus in which the gate driver of claim 8 is mounted, comprising:
a display unit having pixel elements disposed at portions in which a plurality of gate lines and a plurality of data lines intersect,
wherein an output of the gate driver is connected to the gate line,
wherein overlap scanning having a period in which the plurality of gate lines are simultaneously selected is performed, and
wherein the selection period of the gate line is controlled by a pulse width of a start signal.
13. A matrix type display apparatus in which the gate driver of claim 11 is mounted, comprising:
a display unit having pixel elements disposed at portions in which a plurality of gate lines and a plurality of data lines intersect,
wherein an output of the gate driver is connected to the gate line,
wherein overlap scanning having a period in which the plurality of gate lines are simultaneously selected is performed, and
wherein the selection period of the gate line is controlled by a pulse width of a start signal.
14. A shift register circuit including a single conductivity type transistor, comprising:
a shift register unit having a first output transistor which connects an output terminal and a first power supply; and
a first gate control circuit of which an output terminal is connected to a gate terminal of the first output transistor,
wherein the first gate control circuit includes a timing generation unit and a buffer unit,
wherein the buffer unit is a bootstrap circuit,
wherein an output of the timing generation unit to which an input signal is inputted is used as an input of the buffer unit and an output of the buffer unit is used as an output of the first gate control circuit, and
wherein the buffer unit is a bootstrap circuit including at least:
a second transistor and a twelfth transistor which connect an output of the buffer unit and a first clock signal in series; and
a third transistor which connects a gate terminal of the second transistor and an output of the timing generation unit, and
a thirteenth transistor which connects a gate terminal of the twelfth transistor and an output of the shift register circuit of an (n+2)-th stage.