Organic light emitting display device and a method for generating scan signals for driving an organic light emitting display device having a scan driver
AssigneeSamsung Display Co., Ltd.
InventorBo-Yong Chung
Life of this patent
Estimating the term…
Abstract
A system on panel (SOP)-type scan driver for an organic light emitting display (OLED) device. The scan driver includes flip-flops. Each of the flip-flops receives an input signal, a clock signal, and an inverted clock signal and outputs a scan signal. The scan signal is shifted and input to an adjacent flip-flop. Each of the flip-flops includes three transistors of the same conductivity type and a capacitor. Thus, layout area is minimized owing to simplification of circuits, and static current is cut off to reduce power consumption.
Claims16
An organic light emitting display device comprising:
- a display region comprising pixels for displaying an image;
- a scan driver comprising scan signal circuits for applying a scan signal to select the pixels;
- a data driver for applying a data signal to the selected pixels;
- and
- an emission control driver for applying an emission control signal for controlling an emission operation of the pixels,
- wherein at least one of the scan signal circuits of the scan driver includes a three-transistor flip-flop having only three transistors, two of which are configured to be driven by a same control signal, the three-transistor flip-flop including:
- a first transistor, coupled between
- a constant positive power supply voltage terminal configured to supply a constant positive power supply voltage, and
- a signal line for the scan signal, and configured to turn on/off by the same control signal being applied to a gate terminal of the first transistor;
- a second transistor, connected between the signal line for the scan signal and either a signal line for a clock signal or a signal line for an inverted clock signal, and configured to turn on/off according to a voltage at a gate terminal of the second transistor;
- a third transistor comprising a first electrode coupled to the gate terminal of the second transistor, and a second electrode configured to transmit an input signal to the first electrode by the same control signal being applied to a gate terminal of the third transistor;
- and
- a control signal input portion, commonly coupled to the gate terminal of the first transistor and the gate terminal of the third transistor, and for applying the same control signal of a low or high level in response to either a clock signal or an inverted clock signal.
An organic light emitting display device comprising:
- a data driver for generating data signals corresponding to an image to be displayed by the device;
- and
- an electroluminescent panel coupled to the data driver, the electroluminescent panel comprising:
- a scan driver for generating scan signals, the scan driver comprising:
- scan signal circuits, each scan signal circuit comprising a three-transistor flip-flop having only three transistors, two of the three transistors being configured to be driven by a same control signal,
- wherein the three-transistor flip-flops are coupled together, a first three-transistor flip-flop of the three-transistor flip-flops for receiving a clock signal as the same control signal and a start pulse as an input signal and generating a first scan signal, a second three-transistor flip-flop of the three-transistor flip-flops for receiving an inverted clock signal as another same control signal and the first scan signal as an input signal and generating a second scan signal, the second scan signal being shifted by a half cycle of the clock signal with respect to the first scan signal;
- an emission control driver for generating emission control signals;
- and
- a display region including pixels coupled to the data driver, the scan driver and the emission control driver, for receiving the data signals, the scan signals and the emission control signals, the pixels being controlled by the scan signals and the emission control signals, the pixels for generating light according to the data signals,
- wherein each of the three-transistor flip-flops includes three transistors of a first conductivity type and a capacitor.
A method for generating scan signals for driving an organic light emitting display device having a scan driver comprising scan signal circuits, each scan signal circuit comprising a three-transistor flip-flop having only three transistors, two of the three transistors being driven by a same control signal, wherein the three-transistor flip-flops are coupled together in series, a first one of the three-transistor flip-flops for receiving a start pulse as input and each of the three-transistor flip-flops after the first one of the three-transistor flip-flops for receiving an output signal of a previous one of the three-transistor flip-flops as input, and the output signal of each one of the three-transistor flip-flops being one of the scan signals, the method comprising:
- providing a clock signal having a low level during a first half clock cycle as the same control signal to the first one of the three-transistor flip-flops;
- providing the start pulse having the low level during the first half clock cycle as the input to the first one of the three-transistor flip-flops;
- generating a first one of the scan signals by the first one of the three-transistor flip -flops, the first one of the scan signals having a high level during the first half clock cycle and the low level during a second half clock cycle;
- providing an inverted clock signal having the low level during the second half clock cycle as another same control signal to a second one of the three-transistor flip-flops coupled to the first one of the three-transistor flip-flops;
- providing the first one of the scan signals as the input to the second one of the three -transistor flip-flops;
- and
- generating a second one of the scan signals by the second one of the three-transistor flip -flops, the second one of the scan signals having the high level during the first half clock cycle and the second half clock cycle and the low level during a third half clock cycle,
- wherein the three-transistor flip-flops include transistors of only a first conductivity type.
An organic light emitting display device comprising:
- a display region comprising pixels for displaying an image;
- a scan driver comprising three-transistor flip-flops for applying a scan signal to select the pixels;
- a data driver for applying a data signal to the selected pixels;
- and
- an emission control driver for applying an emission control signal to control an emission operation of the pixels,
- wherein at least one of the three-transistor flip-flops of the scan driver has only three transistors, two of which are configured to be driven by a same control signal, the at least one of the three-transistor flip-flops including:
- a first transistor, coupled between
- a constant positive power supply voltage terminal configured to supply a constant positive power supply voltage, and
- a signal line for the scan signal, and configured to turn on/off by the same control signal being applied to a gate terminal of the first transistor;
- a second transistor, connected between the signal line for the scan signal and a signal line for an inverted same control signal, and configured to turn on/off according to a voltage at a gate terminal of the second transistor;
- and
- a third transistor comprising a first electrode coupled to the gate terminal of the second transistor, and a second electrode configured to transmit an input signal to the first electrode by the same control signal being applied to a gate terminal of the third transistor.
Dependencies are inferred from the claim text.