Sharp Kabushiki Kaisha Corporation

Katsuya Otoi

Hiroyuki Furukawa

Noritaka Kishi

Tamotsu Sakai

Kazuyoshi Yoshiyama

Naoko Gotoh

Katsuteru Hashimoto

Kohji Fujiwara

Naoko Goto

Noboru Noguchi

Shigetsugu Yamanaka

Masaaki Moriya

Takayuki Murai

Yoshimitsu Murahashi

Kensuke Takai

Hideaki Kawamura

Zhang Xiaomang

An organic EL display device includes: a pixel circuit drive unit configured to drive pixel circuits while performing a property measuring process in which a property of circuit elements is measured; a parameter table configured to store parameter values derived from monitoring data obtained in the property measuring process; a compensation computation unit configured to correct externally provided image data based on the parameter values stored in the parameter table, so as to generate a digital video signal to be fed to the pixel circuits; a temperature sensor configured to sense temperature; and a monitoring control section configured to control an execution frequency of the property measuring process in accordance with the sensed temperature. The monitoring control section increases the execution frequency of the property measuring process with an increase in the sensed temperature.

Display device and driving method therefor

In a data line drive/current measurement circuit, m measurement units are disposed in a plurality of semiconductor chips such that the m measurement units are distributed among the plurality of semiconductor chips. A display apparatus includes transistors such that one transistor is provided for two adjacent semiconductor chips. Inter-chip correction data indicating a variation among the semiconductor chips in terms of characteristics of elements in the measurement units is determined based on a result of a current measurement performed for the same transistor using measurement units disposed in different semiconductor chips. The inter-chip correction data is stored in a storage unit and is used in correcting an image signal. The inter-chip correction data may be determined based on a result of measuring a current flowing through a common cathode of organic EL elements for each semiconductor chip. Thus, a variation in the characteristic of the element among the semiconductor chips is compensated for and high image quality is achieved in displaying.

Display apparatus and driving method therefor

A measurement circuit includes a plurality of measurement units, performs, at a same timing, a main measurement for measuring a current or a voltage with respect to a pixel circuit with supplying a measurement voltage to a part of the measurement units and a dummy measurement for measuring a current or a voltage with supplying a dummy signal to remaining measurement units, and performs a calculation on a result of the main measurement and a result of the dummy measurement. As the dummy signal, a signal with which a value to be measured is approximately zero is used. The measurement result of the current or the voltage is used for correcting a video signal. With this, a display device which can remove noise in measurement when measuring the current or the voltage with respect to the pixel circuit is provided.

Display device and drive method therefor

A current measurement circuit measures a current flowing through a drive transistor when a plurality of measurement voltages are written to a pixel circuit in a switching manner, and a current flowing through an organic EL element when another plurality of measurement voltages are written to the pixel circuit in a switching manner. A correction unit obtains a threshold voltage and a gain of the drive transistor and the organic EL element with respect to each pixel circuit based on a measured current, determines in which operation region the drive transistor operates between a saturation region and a triode region with respect to each pixel circuit based on the video signal, and corrects the video signal in accordance with the operation region of the drive transistor. Since the drive transistor operates both in the saturation region and the triode region, it is possible to reduce a power supply voltage and reduce power consumption of a display device.

It is possible to realize a liquid crystal display devicewhich is provided with a down-converter, a local dimming control circuit, and an upscaling control circuitincluding a luminance ratio calculation circuit and a gradation conversion circuit, and thus, capable of processing an image having an image size that is not assumed, and further, reducing a storage area, a processing load and a circuit size.

Liquid crystal display device

In a current measurement period of a pixel circuit (), a measurement voltage is applied to a non-inverting input terminal of an operational amplifier (), switches () turn on, and a switch () turns off. Next, the switch () turns off, and a capacitor () is charged with charge of a current flowing through the pixel circuit (). Next, the switch () turns off, the switch () turns on, a constant current flows through a current source (), and a voltage of a second terminal (terminal connected to an output terminal of the operational amplifier ()) of the capacitor () decreases. A voltage comparator () and a counter () measure the current flowing through the pixel circuit () by measuring time until a voltage of the second terminal of the capacitor reaches a voltage Vcomp. A video signal VSis corrected based on a current measurement result. With this, it is possible to compensate for capacitance variation of a capacitance in a current measurement circuit and perform high image quality display.

A video processing device detects, as a characteristic region, a region having a prescribed characteristic in each frame of a video and performs specific image processing on either the characteristic region in the frame or a region other than the characteristic region in the frame with a specified processing strength. The processing strength is specified so as to be altered stepwise in at least two steps that involve an intermediate value between a minimum value and a maximum value when there is a change in whether or not a characteristic region has been detected.

Video processing device

Control sections of displayseach determine control information Pi used when area-active driving is performed individually and transmit the control information Pi to a multi-display control section. The multi-display control sectiondetermines control information Ps for the entire device on the basis of the received pieces of control information Pi and transmits the control information Ps to the control sections of the displays. All the displaysperform area-active driving on the basis of the same control information Ps. In this way, occurrence of a luminance difference or chromaticity difference among display screens of the displaysis prevented and the quality of a displayed image is improved.

Image display device and image display method of a multi-display type with local and global control

In an image display device which performs area-active drive, backlight sources are emitted with appropriate luminances while inhibiting increase in power consumption and inhibiting reduction of image quality. An emission luminance calculation section divides an input image into a plurality of areas, and obtains luminances upon emission (first emission luminances) of LEDs in the areas. A plurality of correction modes are prepared as methods for correcting the first emission luminances, and a correction mode that is applied to an emission luminance correction process (selected correction mode) is stored to a correction mode storage section. For any LED units whose flag data stored in a correction-enabled map has the value of 1, an emission luminance correction section corrects their first emission luminances to obtain second emission luminances in accordance with the selected correction mode, with reference to correction value data stored in correction value tables.

Image display device having a plurality of image correction modes for a plurality of image areas and image display method

An image display device which performs area-active drive suppresses occurrence of flickering that is caused when displaying dynamic images due to the emission luminance of each area being determined on the basis of a maximum or mean value of pixel luminances within that area. An emission luminance calculation section () divides an input image () into a plurality of areas, and obtains luminances upon emission of LEDs (first emission luminances) () in the areas. A maximum luminance position eccentricity coefficient calculation section () obtains maximum luminance position eccentricity coefficients () indicating maximum luminance positions in the areas. An emission luminance correction section () corrects the first emission luminances () on the basis of the maximum luminance position eccentricity coefficients () and contribution ratios () stored in an LED filter (). At this time, luminances of areas positioned in the same direction as the maximum luminance positions are set to be relatively high, and luminances of areas positioned in the opposite direction to the maximum luminance positions are set to be relatively low.

Image display device and image display method

An image processing apparatus for processing complementary color image data output from an image capturing element including a complementary-color filter is provided. The apparatus comprises a middle-high-range luminance component compensation section for compensating for a middle-high-range luminance component of a low-frequency luminance signal generated based on the complementary color image data such that the low-frequency luminance signal has substantially an ideal frequency characteristic which is lower than or equal to a predetermined frequency.

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Sakai, Japan

Katsuya Otoi