According to one embodiment, a display apparatus includes a plurality of semiconductor layers, a first insulation film, a first conductive layer, a second insulation film and a display element includes a second conductive layer. The first conductive layer and the second conductive layer are opposed to each other to form a capacitance unit.

The invention provides a threshold voltage detection circuit for OLED display device, providing multiplexer (2) between detection IC (1) and pixel driver unit (3), using the second DC signal (Ovss) having the first and second levels with the first level smaller than the detection control signal (Monitor) and the second level larger than the detection control signal (Monitor), during the detection for driver TFT, the second DC signal (Ovss) being switched to the second level, and during the detection for OLED, the second DC signal (Ovss) being switched to the first level, the data signal (Data) being at the same level as the detection control signal (Monitor) to achieve one-by-one threshold voltage detection for the OLED and driver TFT of each sub-pixel driver circuit, reduce the current leakage, improve detection accuracy and prolong OLED lifespan.

The invention provides a threshold voltage detection circuit for OLED display device, providing multiplexer (2) between detection IC (1) and pixel driver unit (3), using the second DC signal (Ovss) having the first and second levels with the first level smaller than the detection control signal (Monitor) and the second level larger than the detection control signal (Monitor), during the detection for driver TFT, the second DC signal (Ovss) being switched to the second level, and during the detection for OLED, the second DC signal (Ovss) being switched to the first level, the data signal (Data) being at the same level as the detection control signal (Monitor) to achieve one-by-one threshold voltage detection for the OLED and driver TFT of each sub-pixel driver circuit, reduce the current leakage, improve detection accuracy and prolong OLED lifespan.

By a drive method, for each of a plurality of display pixels each including an EL element, a capacitor, a drive transistor, an enable switch, and a switch, a period T21 is started by switching only the enable switch to an electrically conductive state before a period T22 in which the drive transistor is initialized, and the period T22 following the period T21 is started by switching the switch to an electrically conductive state. The period T21 is longer than a period T24 in which a threshold voltage of the drive transistor is compensated.

By a drive method, for each of a plurality of display pixels each including an EL element, a capacitor, a drive transistor, an enable switch, and a switch, a period T21 is started by switching only the enable switch to an electrically conductive state before a period T22 in which the drive transistor is initialized, and the period T22 following the period T21 is started by switching the switch to an electrically conductive state. The period T21 is longer than a period T24 in which a threshold voltage of the drive transistor is compensated.

A device includes a matrix of active pixels, with each active pixel having an OLED diode having a cathode to receive a cathode voltage, and a control circuit coupled to an anode of the OLED diode. The device also includes at least one dummy pixel having a dummy OLED diode having a cathode to receive the cathode voltage, and an anode, and a dummy control circuit coupled to the anode of the OLED diode and having a power supply terminal. The dummy OLED diode and the dummy control circuit are substantially similar to the OLED diode and the control circuit. First regulation circuitry is configured to deliver a reference current to the power supply terminal to thereby generate a voltage, and second regulation circuitry is configured to regulate the cathode voltage so as to maintain the voltage at the power supply terminal at a given level.

A device includes a matrix of active pixels, with each active pixel having an OLED diode having a cathode to receive a cathode voltage, and a control circuit coupled to an anode of the OLED diode. The device also includes at least one dummy pixel having a dummy OLED diode having a cathode to receive the cathode voltage, and an anode, and a dummy control circuit coupled to the anode of the OLED diode and having a power supply terminal. The dummy OLED diode and the dummy control circuit are substantially similar to the OLED diode and the control circuit. First regulation circuitry is configured to deliver a reference current to the power supply terminal to thereby generate a voltage, and second regulation circuitry is configured to regulate the cathode voltage so as to maintain the voltage at the power supply terminal at a given level.

A pixel circuit and a display panel are disclosed. The pixel circuit comprises a first transistor, a pulse amplitude driving module, and a pulse width driving module. The pixel circuit and the display panel utilize a pulse amplitude driving module to drive the first transistor when a middle to high gray value of a frame is being displayed such that the number of frequency divisions in a high gray value could be reduced. Furthermore, the pixel circuit and the display panel utilize a pulse width driving module to drive the first transistor when a middle to low gray value of the frame is being displayed to improve the light emitting efficiency and luminance evenness in a low gray value.

A pixel circuit and a display panel are disclosed. The pixel circuit comprises a first transistor, a pulse amplitude driving module, and a pulse width driving module. The pixel circuit and the display panel utilize a pulse amplitude driving module to drive the first transistor when a middle to high gray value of a frame is being displayed such that the number of frequency divisions in a high gray value could be reduced. Furthermore, the pixel circuit and the display panel utilize a pulse width driving module to drive the first transistor when a middle to low gray value of the frame is being displayed to improve the light emitting efficiency and luminance evenness in a low gray value.

A display device that can compensate for degradation of circuit elements while suppressing an increase in circuit size is implemented. A data signal line (S(j)) is not only used as a signal line that transfers a signal for allowing an organic EL element (OLED) in each pixel circuit (11) to emit light at a desired luminance, but also used as a signal line for characteristic detection. In addition, a switch (334) is provided between the data signal line (S(j)) and an internal data line (Sin(j)). In such a configuration, during an AD conversion period during which analog data obtained for characteristic detection is converted into digital data, the switch (334) is brought into an off state and a potential of the data signal line (S(j)) obtained immediately before the AD conversion period is supplied from through a predetermined control line (CL) to the data signal line (S(j)).