46results about How to "Luminance can be corrected" patented technology

In a driving circuit of a spontaneous light emitting display device driven as an active matrix, a noise current is prevented from flowing in a light emitting element when compensating for a threshold voltage of a transistor for controlling current flowing to the emitting element, enhancing precision in luminance. A switching element for short-circuiting electrodes of the spontaneous light emitting element for a period in which the noise current flows in the light emitting element bypasses the noise current.

A light emitting device is provided, in which a change of luminance of an OLED is suppressed and a desired color display can be stably performed even if an organic light emitting layer is somewhat deteriorated or an environmental temperature is varied. Separately from a pixel portion for displaying an image, a pixel portion for measuring a driving current of the OLED is provided in the light emitting device. The driving current is measured in the pixel portion for measuring the driving current of the OLED, and a value of the voltage supplied to the above two pixel portions from a variable power supply is corrected such that the measured driving current has a reference value. With the above-described structure, a reduction of the luminance accompanied with the deterioration of the organic light emitting layer can be suppressed. As a result, a clear image can be displayed.

A luminance correction system includes an image pickup device configured to pick up a test image and generate pickup data, a parameter calculation device configured to calculate a first target luminance that is a maximum luminance of a reference area in a display panel and a detected maximum luminance that is a luminance of a correction target sub-pixel based on the pickup data with respect to a maximum grayscale, determine a second target luminance by correcting the first target luminance, and calculate correction parameters, and a display device including the display panel, the display device configured to compensate the input grayscale of the correction target sub-pixel to a target grayscale based on the correction parameters and generate a data voltage by adjusting upward a gamma voltage corresponding to the target grayscale.

A unit equivalent value acquiring unit acquires a normal-temperature unit equivalent use time Δtn by using a temperature sensor, first to third LUTs, and a first multiplying unit. An integration unit acquires an equivalent cumulative use time to by integrating the normal-temperature unit equivalent use time Δtn. A maximum value detecting unit detects a maximum equivalent cumulative use time tnmax. A dividing unit acquires a correction coefficient Kcmp by dividing total degradation E(tnmax,Tn) acquired by a fourth LUT by total degradation E(tn,Tn) acquired by a fifth LUT. Accordingly, there is provided a data processing device for a display device capable of preventing burn-in while suppressing time degradation of an electro-optical element and increase in the number of wires.

A display device and a driving method thereof. The display device includes a plurality of pixels, each receiving a predetermined on-bias voltage transferred through a data line during one frame, receiving a first image data signal corresponding to the corresponding frame through the data line and storing the same, and emitting light according to a driving current that corresponds to a second image data signal that corresponds to the previous frame of the corresponding frame, and a first period for storing the first image data signal and a second period for light emission according to a driving current corresponding to the second image data signal overlap each other in one frame.

Aspects of the invention can provide a digital-to-analog converting circuit capable of, after converting digital data into an analog current, correcting the current value based on digital current correction data without any complex processing. The exemplary digital-to-analog converting circuit can include a first digital-to-analog converting circuit portion and a second digital-to-analog converting circuit portion. First digital data (image data) can input to the first digital-to-analog converting circuit portion, and second digital data (current correction data) can input to the second digital-to-analog converting circuit portion. After the first digital-to-analog converting circuit portion converts the image data into a first analog current, the second digital-to-analog converting circuit portion can correct the first analog current based on the current correction data, and outputs the corrected current as a second analog current.

A luminance correction system comprises: a data applying unit coupled to a panel of the flat panel display, and configured to apply data including center gamma value information according to a selected luminance mode to the panel; an image analyzing unit configured to analyze an image displayed on the panel according to the data and output at least one analyzed result; an offset value setting unit coupled to the image analyzing unit, and configured to generate a reference offset value corresponding to a center gamma value for a reference luminance and the at least one analyzed result, and to generate an additional offset value corresponding to the second luminance mode and the at least one analyzed result when a second luminance mode is selected; and a data adjusting unit coupled to the offset value setting unit, and configured to adjust the data according to the reference offset value and supply the adjusted data to the data applying unit.

A display device includes: an LED control section (4) for carrying out control in which (i) an output luminance of an LED (10) whose measured luminance is deviated from a reference luminance or (ii) output luminances of peripheral LEDs (10) which are provided around the LED (10) is or are corrected, respectively, by using control information of the plurality of LEDs, which control information contains (a) information on measured luminances of the plurality of LEDs, the information being obtained by the plurality of photosensors (11) and (b) positional information of the plurality of LEDs, the positional information being obtained by the plurality of photosensors (11), and a liquid crystal display control section (3) for controlling, based on (i) video signals which have been subjected to the video signal process and are supplied from a video signal processing section (2) and (ii) the control information supplied from the LED control section (4), (a) levels of video signals to be supplied to pixels corresponding to the LED (10), whose output luminance is corrected or (b) levels of video signals to be supplied to pixels corresponding to the peripheral LEDs, whose output luminances are corrected, the reference luminance being a luminance which is originally expected to be outputted from each of the plurality of LEDs.

In a pixel circuit 100, a driving TFT 110, a switching TFT 115, and an organic EL element 130 are provided between a power supply wiring line Vp and a common cathode Vcom and a capacitor 120 and a switching TFT 111 are provided between a gate terminal of the driving TFT 110 and a data line Sj. A switching TFT 112 is provided between a connection point B between the capacitor 120 and the switching TFT 111 and the power supply wiring line Vp, a switching TFT 113 is provided between the gate and drain terminals of the driving TFT 110, and a switching TFT 114 is provided between the gate terminal of the driving TFT 110 and a reference supply wiring line Vs. A potential that brings the driving TFT 110 into a conduction state is applied to the reference supply wiring line Vs. Thus, variations in the threshold voltage of a drive element can be properly compensated for and unwanted light emission from an electro-optical element can be prevented.

In order to keep the luminance of a light emitting element constant, the correction is performed by an external device such as a computer, in which case a display device is inevitably complicated and increased in size. Even when degradation characteristics of the light emitting element are previously stored in a computer, the degradation characteristics vary at random depending on hysteresis of the light emitting element; therefore, changes in luminance cannot be corrected. According to the invention, a display device includes a displaying light emitting element provided in a display portion and a plurality of monitoring light emitting elements having the similar characteristics as the displaying light emitting element. At least one of the monitoring light emitting elements is operated under a condition different from the displaying light emitting element, and the ratio of the total amount of charge flowing through the displaying light emitting element to that flowing through the monitoring light emitting element is controlled to satisfy a certain relation in view of luminance degradation. When the one monitoring light emitting element reaches a predetermined voltage or time, the connection is switched from the one monitoring light emitting element to another monitoring light emitting element that has been operated under the same condition as the displaying light emitting element.

An LCD driver compares an image signal with a count of a counter repeatedly counting a clock. Based on the result of the comparison, the LCD driver outputs pulses each having a duty factor in accord with the image signal. When the count is not between first and second predetermined numbers, the frequency of the clock supplied to the counter is switched from a fundamental frequency to a low-frequency, thereby controlling the width of a drive voltage of a liquid crystal display cell and correcting the image signal in association with the S-shape characteristic of optical transmittance of the liquid crystal display cell. This LCD driver is advantageously simple in structure.

A liquid crystal display device capable of correcting variation in luminance in a drive beginning period of the liquid crystal display device with a simple configuration by a microcomputer 15 referring to a luminance stabilization program and a look-up table recorded on a ROM 16 and executing contrast adjustment of the video signal by the video circuit 12 based on the look-up table, and a liquid crystal television using the liquid crystal display device are provided.

An LED display apparatus includes an LED aging unit, a correction factor computing unit, and a luminance correction circuit. The LED aging unit includes an LED aging display that includes at least one second LED, a luminance measurer that measures luminance decrease rates of the second LED per color correspondently to lighting periods of first LEDs, and a luminance decrease rate storage that stores the luminance decrease rates. The correction factor computing unit computes correction factors for correcting luminances of the first LEDs per color in accordance with cumulative lighting periods of the first LEDs of corresponding colors and the luminance decrease rates of corresponding colors. The luminance correction circuit corrects the luminance of the first LEDs per color in accordance with the correction factors.

An LED driver circuit includes a power controller, a voltage regulator, a detecting resistor, a light emitting device, and a voltage detecting circuit. The voltage detecting circuit has a first input end connected to a higher potential end of the detecting resistor, and a second input end thereof is connected to a lower potential end of the detecting resistor. The output end of the voltage detecting circuit is connected to a feedback end of the power controller so as to output a detected voltage signal to the power controller for adjusting the output voltage and supplying a stable and proper value of current to the light emitting device. The voltage detecting circuit is a differential amplifier capable of detecting the voltage difference between the detecting resistor and amplifying it as a feedback to the power controller. Therefore, the output current from the power controller is precisely controlled.

A method and a system for adaptively (dynamically) reducing quantization layer reduction for removing quantization artifacts in quantized video signals is provided. Adaptively reducing quantization layer reduction involves detecting if a selected pixel in a quantized image belongs to a ramp area in each of multiple pre-defined directions, dynamically selecting a quantization level for each of the pre-defined directions based on the corresponding detection results, and refining the pixel based on the selected quantization levels.