Sharp Kabushiki Kaisha Corporation

The Secretary of State for Defence in Her Britannic Majesty's Government

The Secretary of State for Defense in Her Britannic Majesty's Government

Shigetsugu Okamoto

Michiyuki Sugino

Tadao Kyomoto

Hirofumi Katsuse

A display element, provided at each point of intersections of a plurality of signal lines and a plurality of scanning lines, includes an optical modulation elementand an active element, wherein, when a scanning is carried out not less than once in one field period at a predetermined intervals, a memory elementwhich can store M-bit (M&#x2267;1) information at the maximum is provided so that the optical modulation elementkeeps the display with 2-level gray scale until the next scanning. On this account, it is possible to supply gray scale signal data Dm to the optical modulation elementso as to keep the display condition, without attenuating the data after the scanning of pixels. Moreover, since the level of the gray scale display is kept by outputting the information stored in the memory element, the gray scale level in each time division sub field can be in concordance with the number of memory bits.

Display element and gray scale driving method thereof

A display-unit-use display control method controls display of pixels in a display unit including a large number of light emitting elements in a row direction and a column direction, the light emitting elements having brightness, which changes in accordance with a value of current supplied thereto. A current is supplied, the current supplying conductor from one or each end part thereof in a column direction, the current supplying conductor supplying the current to the light emitting elements. The pixels are displayed line by line in accordance with a selection timing, and the display of pixels is deleted line by line in accordance with a deletion timing. It is so arranged that with respect to a certain line, a period from a time at which the pixels get displayed in accordance with the selection timing to a time at which the display of the pixels gets deleted is shorter than a period between start and end of the selection timing.

Display unit operating control method, display control method, and display apparatus

A display element included in a display device is provided with a TFT circuit portion and a pixel aperture portion to which an organic EL element material is applied and which emits light in accordance with a current from the TFT circuit portion, as well as a scanning signal line electrode, a data signal line electrode and a power source line electrode. The resistance Re of the power source line electrode can be reduced, because the electrode width at a portion where the power source line electrode is in contact with the pixel aperture portion is larger than the electrode width at other portions. The resistance ratio Rx/Re between the electrode resistance Re and a combined resistance Rx of a current path from the power source line electrode through the pixel aperture portion is at least 10. Thus, a display element and a display device are realized, which have little luminance variation within the display screen, which have a high numerical aperture, a high light emission efficiency and a long lifetime.

Display element and display device

When reproducing an image by a display apparatus having a plurality of pixels, in an average signal level operation circuit is performed an operation to obtain an average signal level which is an average level of all the pixel signals in a picture signal including a pixel signal representing information of a pixel, then, according to this average signal level, in an input signal-output brightness property setting circuit is set an input signal-output brightness property representing variations in brightness of a pixel with respect to a level of the pixel signal, then, the compensation of the picture signal is performed either to satisfy the input signal-output brightness property thus set in a signal compensation section or to allow variations in maximum output brightness of a pixel of the display apparatus according to the average signal level in a maximum output brightness adjustment circuit, so as to output the picture signal subject to compensation to the display apparatus.

Image reproducing method, image display apparatus and picture signal compensation device

A gray level shift is detected as to adjacent pixels in the same field as that of an original signal inputted, so that gray level information is obtained. Concurrently with this step, a motion speed of the picture is detected as to each pixel of the original signal, so that motion information is obtained. A correction gray level signal according to the foregoing gray level information and motion information is obtained, and the correction gray level signal is outputted to the original signal. It therefore results in that a motion picture pseudo contour is detected as to two factors of space and time, and hence, not only the magnitude of gray level turbulence but also a range of pixels affected by the gray level turbulence can be accurately detected.

Motion picture pseudo contour correcting method and image display device using the method

In each pixel of a display element, a memory circuit is made up of two complementary inverters which are connected to each other in a loop manner, and stores whether or not to light an Organic Emission Diode, according to a potential which is given via a select circuit in a select period. An output end of one of the inverters is directly connected to an anode of the Organic Light Emission Diode, and both TFTs of the inverter drive the Organic Light Emission Diode. Thus, even though dispersion in manufacturing occurs, it is possible to light/unlight the Organic Light Emission Diode at the same luminance level. As a result, even though dispersion occurs in characteristics of elements which make up a pixel, it is possible to realize a memory-integrated display element which can light the optical modulation element at the same luminance level.

Memory-integrated display element

A liquid crystal display element is arranged so that a scanning line electrode group and a signal line electrode group, which are formed by arranging a plurality of electrodes parallel, are placed in a direction where they intersect each other, and liquid crystal intervenes between these electrode groups, and input directions of signal voltages to be applied to the signal line electrode group are opposite in some electrode. As a result, nonuniformity of temperature on a display screen, which is caused by heat generation according to driving of the liquid crystal and causes variations of a driving property of the liquid crystal, is suppressed, and thus a satisfactory display state is realized.

Liquid crystal display element having opposite signal voltage input

A ferroelectric liquid crystal display element is structured so that ferroelectric liquid crystal is provided between a plurality of signal line electrodes and a plurality of scanning line electrodes running perpendicular to one another, and includes a signal line electrode driving circuit made up of a gray-scale signal amplifying circuit and a gray-scale signal producing circuit, and a scanning line electrode driving circuit made up of a scanning signal amplifying circuit and a scanning signal producing circuit. The signal line electrode driving circuit applies to the signal line electrodes gray-scale signals including pulses which are phase modulated in accordance with a gray-scale level, and the scanning line electrode driving circuit selectively applies to the scanning line electrodes scanning signals including, in each scanning period, an erasure voltage, a selection voltage, and a non-selection voltage. Driving characteristics obtained by these means are more stable than those obtained using amplitude-modulated or frequency-modulated gray-scale signals. As a result, intermediate shades can be stably displayed in a display element using ferroelectric liquid crystal.

Driving method and driving circuit for ferroelectric liquid crystal

A liquid crystal display apparatus using a ferroelectric liquid crystal with negative dielectric anisotropy in which a blanking pulse having a width that is at least twice of a selecting period and a polarity opposite to a strobe pulse to be applied to a scanning electrode in the selecting period is applied to the scanning electrode before the selecting period during one frame period. Another liquid crystal display apparatus using a ferroelectric liquid crystal with negative dielectric anisotropy in which a strobe pulse is applied to a scanning electrode in a trailing part of the selecting period and a predetermined period that follows the selecting period. A blanking pulse of opposite polarity to the strobe pulse is applied to the scanning electrode before the selecting period in one frame period. A non-selecting period which is at least three times longer than the selecting period is provided between the blanking pulse and the selecting period.

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Nara, Japan

Shigetsugu Okamoto