A system reads a desired circuit parameter from a pixel circuit that includes a light emitting device, a drive device to provide a programmable drive current to the light emitting device, a programming input, and a storage device to store a programming signal. One embodiment of the extraction system turns off the drive device and supplies a predetermined voltage from an external source to the light emitting device, discharges the light emitting device until the light emitting device turns off, and then reads the voltage on the light emitting device while that device is turned off. The voltages on the light emitting devices in a plurality of pixel circuits may be read via the same external line, at different times.

An active matrix organic light-emitting diode (AMOLED) display device and a controlling method thereof. The AMOLED display device (100) comprises a system power IC (110), a driver IC (120), an AMOLED panel (130), a power line (111) and a feedback line (112). The AMOLED panel (130) includes a plurality of pixel circuits. The system power IC (110) outputs a positive power supply voltage (ELVdd1) to the plurality of pixel circuits via the power line (111), and the driver IC (120) detects a positive power supply voltage (ELVdd2) actually applied to the plurality of pixel circuits via the feedback line (112) and compensates for data voltages (Vdata) based on the positive power supply voltage (ELVdd2) actually applied to plurality of pixel circuits. The driving chip detects the positive power supply voltage (ELVdd2) actually applied to plurality of pixel circuits, and automatically adjusts a minimum grayscale voltage (VREG1) and a maximum grayscale voltage (VGS) based on the positive power supply voltage (ELVdd2) actually applied to the plurality of pixel circuits, such that a certain difference value can be maintained between the data voltage (Vdata) and the positive power supply voltage (ELVdd2) actually applied to the plurality of pixel circuits, thus eliminating Gamma offset.

A method of displaying an image by using a display device. The method includes: grouping pixels included in a display unit into pixel blocks, generating a first accumulated stress map representing a degree of a deteriorated performance of the pixels included in the pixel blocks based on first image data of a current frame image, and determining a shiftable range of the current frame image by analyzing the first accumulated stress map. The first image data is corrected to second image data in which the current frame image is shifted within the shiftable range.

A display device includes a first switching element including a second electrode and a first gate electrode, a second switching element including a third electrode connected with the first gate electrode, a third switching element including a fifth electrode connected with the second electrode, and sixth electrode, a fourth switching element including a seventh electrode connected with the second electrode, and an eighth electrode, a fifth switching element including a ninth electrode connected with the second electrode, and a tenth electrode, a first light emitting diode connected with the sixth electrode and the eighth electrode, a second light emitting diode connected with the eighth electrode and the sixth electrode, and a switch selectively connecting a common power source line with the sixth electrode or the eighth electrode. The first light emitting diode and the second light emitting diode have different polarities from each other with respect to a same direction.

A voltage converter includes an input voltage line; an inductor coupled to the input voltage line; transistors coupled to the inductor; an output voltage line coupled to at least one of the transistors; a current sensor coupled to at least one of the input voltage line, the inductor, or the output voltage line; and a comparator coupled between the current sensor and the transistors. A DC-DC converter may include a voltage converter having an inductor and a plurality of transistors and configured to convert an input voltage into a power voltage and output the power voltage to an output terminal, an input current sensor configured to sense the input current of the converter, and a controller configured to change the slew rate of an inductor voltage in response to the input current of the converter and a preset reference current.

Video displayers are provided for detecting image freezing in a video displayer with a multi-layer panel including a front layer and a pixel layer emitting pixel light in emitting direction towards the front layer. Front layer and pixel layer are configured to let light through. Video displayers further include a light reflector arranged in the multi-layer panel between pixel layer and front layer to reflect the pixel light from pixel layer in reflection direction towards pixel layer; a light sensor arranged to receive the reflected pixel light at receiving location and sense light variations in received reflected pixel light; and a control unit to receive light variations sensed by light sensor and to detect image freezing depending on received sensed light variations. Methods and computer programs implementing such methods are also provided which are performable by proposed video displayers.

In a display apparatus, a display panel includes a pixel array of pixels, each pixel disposed on one of a plurality of row lines and including a plurality of inorganic LEDs, and a sub pixel circuit corresponding to each of the plurality of LEDs. Each sub pixel circuit includes a PMOSFET driving transistor, and drives a corresponding LED based on an applied image data voltage. A sensing part senses a current through the driving transistor of at least one sub pixel circuit based on a specified voltage applied to the sub pixel circuit, and outputs corresponding sensing data. A correcting part corrects an image data voltage applied to the sub pixel circuit based on the sensing data. In each LED, an anode electrode is coupled to a common node to which a driving voltage is applied, and a cathode electrode is coupled to a source terminal of the driving transistor.

A display device comprises: a display module including a display panel; a control board for controlling the display module; and a power board for outputting direct current voltage to the display module. The power board changes the pulse frequency of a control signal so as to output direct current voltage adjusted according to changes in the load of the display panel.

The present disclosure provides a device and a method for detecting a screen freeze error of a display of a vehicle. The method comprises monitoring a drive pattern of at least one pixel in a porch area during a time period corresponding to a plurality of image frames, wherein the porch area including at least one of a front porch area and a back porch area of a display panel driven according to the plurality of image frames; and determining occurrence of a screen freeze error by comparing the drive pattern of the at least one pixel with a preset drive pattern.

There are provided methods for driving an electro-optic display having a plurality of display pixels, a such method includes detecting a white-to-white graytone transition on a first pixel; and determining whether a threshold number of cardinal neighbors of the first pixel are not making a graytone transition from white to white, or if the first pixel is a color pixel, and apply a first waveform.