Scan driver and driving method thereof
AssigneeSamsung Display Co., Ltd.
InventorSeong-Il Park
Life of this patent
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Abstract
A display device includes a plurality of scan lines and a scan driver. The scan driver includes a plurality of stages for transmitting a scan signal having a first voltage to the plurality of scan lines, and each of the stages includes a sequential switching unit, a sequential output unit, a concurrent switching unit, and a concurrent output unit. The concurrent output unit includes a first transistor for transmitting a second control signal to the output terminal according to a first control signal during a concurrent driving period before the scan signal is converted from a first level to a second level according to the second control signal, and a gate voltage of the first transistor is controlled by a voltage that is different from the first voltage according to the first control signal.
Claims31
A scan driver comprising a plurality of stages being configured to transmit a scan signal to a plurality of scan lines of a display device,
- wherein each of the stages comprises:
- a sequential switching unit for receiving the scan signal from an output terminal of a previous stage;
- a sequential output unit connected to an output terminal of a same stage of the stages;
- a concurrent switching unit;
- and
- a concurrent output unit connected to the output terminal,
- wherein the sequential switching units of the stages are configured to sequentially scan the scan signal having a first voltage in a first period, and the sequential output units of the stages are configured to sequentially output the scan signal having the first voltage,
- wherein the concurrent switching units of the stages are configured to concurrently output the scan signal having a same voltage in a second period, and the concurrent output units of the stages are configured to concurrently output the scan signal having the same voltage, and
- wherein the concurrent output unit comprises a first transistor for transmitting a second control signal to the output terminal according to a first control signal during the second period, and a gate voltage of the first transistor is controlled by a second voltage that is different from the first voltage according to the first control signal before the scan signal is changed from a first level to a second level according to the second control signal.
A scan driver comprising a plurality of stages being configured to transmit a scan signal to a plurality of scan lines of a display device,
- wherein each of the stages comprises:
- a first transistor connected between a first control terminal supplied with a voltage of a first level or a second level and an output terminal for outputting a scan signal having a voltage according to the voltage of the first control terminal, the first transistor having a gate connected to a first node;
- a second transistor connected between a second control terminal supplied with the voltage of the first level or the second level and the first node, the second transistor having a gate connected to the second control terminal;
- a third transistor connected to a first voltage terminal supplied with a first voltage and the output terminal, the third transistor having a gate connected to a second node;
- a fourth transistor connected between the output terminal and a clock terminal supplied with the voltage of the first level or the second level, the fourth transistor having a gate connected to a third node;
- a sequential driver connected to an input terminal for receiving a scan signal from a previous stage, the first voltage terminal, a second voltage terminal for supplying the second voltage, and the first node to the third node, the sequential driver being configured to operate the third and fourth transistors to sequentially output the scan signal having the second voltage to the output terminal of the plurality of stages during a first period;
- and
- a concurrent driver connected to the first voltage terminal, the second control terminal, the second node, and the third node, the concurrent driver being configured to concurrently turn on the first and second transistors such that the scan signal of a same voltage is concurrently output to the output terminals of the plurality of stages during a second period,
- wherein before the scan signal of the same voltage is changed from a first level to a second level according to the voltage of the first control terminal, each of the stages is configured to control a voltage of the first node to be a third voltage that is different from the second voltage.
A method for driving a scan driver of a display device comprising a plurality of scan lines, the method comprising:
- in sequential driving, in response to a plurality of clock signals each alternately having a first level and a second level, sequentially transmitting a scan signal having a voltage corresponding to the second level to the plurality of scan lines;
- and
- in concurrent driving, concurrently applying the scan signal having the voltage corresponding to the first level or the second level to the plurality of scan lines according to a second control signal having the voltage corresponding to the first level or the second level, in a state in which the plurality of clock signals are maintained as the first level and a first control signal is maintained as the second level,
- wherein in the concurrent driving, before the scan signal is changed from the first level to the second level according to the second control signal, a gate voltage of a first transistor for transmitting the second control signal to an output terminal according to the first control signal is controlled at a first voltage that is different from the voltage corresponding to the second level.
Dependencies are inferred from the claim text.