Level shifter for simultaneous reset and sensing line selection, display apparatus including the same, and driving method thereof
Embodiments relate to a level shifter including a first circuit unit configured to output a start signal, a reset signal, and a node charge signal to a gate driver in response to a start control signal and a node charge control signal that are input from a timing controller, a second circuit unit configured to output an output erase signal and a clock shift stop signal in response to the start signal and the reset signal, and a third circuit unit configured to generate a clock signal based on a clock control signal input from the timing controller and output the generated clock signal to the gate driver in response to the output erase signal and the clock shift stop signal that are output from the second circuit unit, a display device including the same, and a method of driving the display device.
1 . A level shifter, comprising:
a first circuit unit configured to output one or more of a start signal, a reset signal, or a node charge signal to a gate driver in response to one or more of a start control signal or a node charge control signal received from a timing controller;
a second circuit unit configured to output one or more of an output erase signal or a clock shift stop signal in response to one or more of the start signal or the reset signal; and
a third circuit unit configured to, in response to the output erase signal, initiate counting a number of pulses of a clock control signal received from the timing controller while the reset signal output on turn-on level, generate and output a clock signal having a phase corresponding to a pixel line selected based on the counted number of the pulses of the clock control signal to the gate driver.
2 . The level shifter of claim 1 , wherein the first circuit unit is configured to output the start signal and the node charge signal at turn-on levels in response to receiving the start control signal and the node charge control signal at turn-on levels, and is configured to output the reset signal at a turn-on level in response to receiving the start control signal at the turn-on level without the node charge control signal.
3 . The level shifter of claim 1 , wherein the first circuit unit includes a logic gate, which is connected to receive the start control signal and an inverted signal of the node charge control signal and is configured to output the reset signal at the turn-on level in response to the start control signal and the inverted signal of the node charge control signal are both at turn-on levels.
4 . The level shifter of claim 1 , wherein the second circuit unit is configured to output the clock shift stop signal to rise in synchronization with a falling edge of the reset signal and to fall in synchronization with a rising edge of the start signal.
5 . The level shifter of claim 1 , wherein the second circuit unit includes a digital logic gate, and is configured to output the clock shift stop signal at a turn-on level in response to receiving the reset signal at a turn-on level and to output the clock shift stop signal at a turn-off level in response to receiving the start signal at a turn-on level.
6 . The level shifter of claim 1 , wherein the third circuit unit is configured to stop an output of the clock signal in response to receiving the output erase signal at a turn-on level, generate the clock signal having the phase corresponding to the selected pixel line in response to receiving the clock shift stop signal at a turn-on level, and output the clock signal to the gate driver.
7 . A display device, comprising:
a display panel on which pixels are disposed;
a gate driver configured to provide a gate signal to the pixels;
a timing controller configured to control an operating timing of the gate driver; and
a level shifter configured to provide a clock signal to the gate driver based on a clock control signal input from the timing controller,
wherein in operation, when the level shifter outputs a reset signal at a turn-on level to the gate driver during a blank time within a frame, the timing controller applies the clock control signal to the level shifter,
wherein, when the reset signal transitions to a turn-off level, the gate driver provides a gate signal to a pixel line selected based on a number of pulses of the clock control signal to sense characteristics of pixels on the selected pixel line.
8 . The display device of claim 7 , wherein the level shifter is configured to apply the reset signal at a turn-on level to the gate driver to initialize the gate driver.
9 . The display device of claim 7 , wherein, while the reset signal at the turn-on level is output, the pixel line of which characteristic values are sensed is selected based on the clock control signal.
10 . The display device of claim 9 , wherein, while the level shifter outputs the reset signal at a turn-off level for the blank time, the gate driver provides the gate signal to the selected pixel line based on the clock signal provided from the level shifter.
11 . The display device of claim 7 , wherein the level shifter includes:
a first circuit unit configured to output one or more of a start signal, the reset signal, or a node charge signal to the gate driver in response to one or more of a start control signal or a node charge control signal that are input from the timing controller;
a second circuit unit configured to output one or more of an output erase signal or a clock shift stop signal in response to the one or more of the start signal or the reset signal; and
a third circuit unit configured to generate the clock signal based on the clock control signal input from the timing controller and output the generated clock signal to the gate driver in response to the one or more of the output erase signal or the clock shift stop signal that are output from the second circuit unit.
12 . The display device of claim 11 , wherein the first circuit unit is configured to output the start signal and the node charge signal at turn-on levels in response to receiving the start control signal and the node charge control signal at turn-on levels, and is configured to output the reset signal at a turn-on level in response to receiving the start control signal at the turn-on level without the node charge control signal.
13 . The display device of claim 11 , wherein the second circuit unit is configured to output the output erase signal at a turn-on level in response to the reset signal at a turn-on level output from the first circuit unit.
14 . The display device of claim 11 , wherein the second circuit unit is configured to output the clock shift stop signal to rise in synchronization with a falling edge of the reset signal and to fall in synchronization with a rising edge of the start signal.
15 . The display device of claim 11 , wherein the second circuit unit is configured to obtain a pulse counting number from the clock control signal received from the timing controller in response to receiving the reset signal at a turn-on level and to select the pixel line to be sensed based on the pulse counting number.
16 . The display device of claim 15 , wherein the third circuit unit is configured to stop an output of the clock signal in response to receiving the output erase signal at a turn-on level, generate the clock signal having a phase corresponding to the selected pixel line in response to receiving the clock shift stop signal at a turn-on level, and output the clock signal to the gate driver.
17 . A method of driving a display device including a gate driver configured to provide a gate signal to pixels, a timing controller configured to control an operation of the gate driver, and a level shifter configured to provide a clock signal to the gate driver based on a clock control signal input from the timing controller, the method comprising:
a reset and line selection operation of initializing the gate driver in response to a reset signal provided from the level shifter to the gate driver and selecting a pixel line to be sensed based on a number of pulses of the clock control signal applied to the level shifter from the timing controller for a blank time within a frame; and
a sensing operation of applying, by the gate driver, the gate signal to the selected pixel line to sense characteristics of pixels on the selected pixel line based on the clock signal provided from the level shifter to the gate driver, in response to the reset signal transitioning to a turn-off level.
18 . The method of claim 17 , wherein the reset and line selection operation includes:
applying, by the timing controller, a start control signal at a turn-on level to the level shifter;
outputting, by the level shifter, a reset signal at a turn-on level to the gate driver in response to the start control signal;
outputting, by the timing controller, the clock control signal to the level shifter while the reset signal is output by the level shifter at the turn-on level;
counting, by the level shifter, the clock control signal; and
selecting the pixel line to be sensed based on the counting.