323results about How to "Suppress flicker" patented technology

The EL display apparatus according to this invention is provided with an EL light emitting element, a current driving device for driving the EL light emitting element by a current responsive to a source signal represented by a current, and a signal current source (634) for outputting the source signal in response to image signal to the current driving device via a source signal line, the EL display apparatus being further provided with a precharge voltage source (631) for outputting a predetermined voltage and a switching and connecting unit (636, 637) capable of selectively connecting either the signal current source or the precharge voltage source to the source signal line (638).

There are provided a light-emitting device and a driving method thereof capable of suppressing an image blur and a flicker. The light-emitting device includes: a display unit in which a plurality of pixel circuits for allowing light-emitting elements to emit light with brightness corresponding to a data signal is arranged; an image acquiring unit for acquiring a first image and a second image corresponding to times different from each other in a frame period of time, respectively; a data-line driving unit for supplying a data signal corresponding to the first image to the pixel circuits belonging to a first group among the plurality of pixel circuits and supplying a data signal corresponding to the second image to the pixel circuits belonging to a second group other than the first group; and a light-emission control unit for allowing the light-emitting elements of the pixel circuits belonging to the first group to emit light in a first period of the frame period of time and allowing the light-emitting elements of the pixel circuits belonging to the second group to emit light in a second period other than the first period of the frame period of time.

A lighting device for high-pressure discharge lamp for lighting the high-pressure discharge lamp by lowering or raising a DC voltage applied to an input side by a DC / DC converter circuit, then converting the DC power into an AC power by a DC / AC inverter circuit, supplying the AC power to the high-pressure discharge lamp and lighting the high-pressure discharge lamp, wherein when the polarity of the current of the high-pressure discharge lamp lit by the substantially rectangular wave is inverted, the output voltage of the DC / DC converter circuit is set to 1.5 times or more as large as the voltage at the stable lighting time of the high-pressure discharge lamp.

A setting unit selects and sets one of a plurality of commercial power frequencies. A frame rate setting unit sets a frame rate corresponding to the commercial power frequency set by the setting unit. A control unit controls an imaging unit such that imaging is carried out at the frame rate set by the frame rate setting unit to thereby acquire image data successively. A detection unit detects a scanning line part at which luminance changes to differ between image data items successively acquired by the control unit. A changing unit changes the commercial power frequency set by the setting unit in accordance with a detection result obtained by the detection unit.

An image pickup apparatus includes a solid-state imaging device, an accumulating section, first and second imaging parameter setting sections, a calculating section, a flicker detecting section, and a switching section. The accumulating section calculates a projection output value of a predetermined line in a frame. The calculating section calculates inter-frame variations of the projection output values, and calculates a flicker index from the variations of a predetermined number of frames. The flicker detecting section detects the flicker from the index, and controls the switching section in response to the detection result of the flicker, so that the switching section selects either the setting signals from the first imaging parameter setting section or the setting signals from the second imaging parameter setting section. Thus, the charge storage time of the solid-state imaging device is set at either an integer multiple of 1 / 100 second or an integer multiple of 1 / 120 second in response to the frequency (50 Hz or 60 Hz) of a power supply of the fluorescent lighting. The image pickup apparatus can solve a problem of a conventional apparatus in that it is difficult for the conventional apparatus to suppress the flicker in regions where the frequency of the power supply differ from each other.

A look-up table stores a plurality of polarity pattern tables for setting the polarities of pixel voltages of pixel formation portions on a display screen. The plurality of polarity pattern tables are set such that when each of the polarity pattern tables is selected once, the number of positive polarities appearing at each of the pixel formation portions is the same as the number of negative polarities. The polarity instruction signal generation circuit selects one of the polarity pattern tables based on a random number that is outputted from a random number generation circuit, and outputs a polarity instruction signal based on the selected polarity pattern table. Then, the video signal line driving circuit outputs video signals such that a voltage with a polarity in accordance with the polarity instruction signal is applied to each of the pixel formation portions.

A liquid crystal display device according to an embodiment of the present invention includes an active matrix type liquid crystal display panel, in which a set value of a common voltage applied to a common electrode of the liquid crystal display panel is determined based on input image data, and a timing of changing the common voltage to the preset value in accordance with a timing of driving at least one of a scan line and a signal line of the liquid crystal display panel.

A light source device includes a high-pressure discharge lamp for performing electric discharge emission between a pair of electrodes, a lighting device for lighting the high-pressure discharge lamp by supplying a driving current of a predetermined frequency to the high-pressure discharge lamp, and a control device for controlling the lighting device, wherein the control device controls the frequency of the driving current supplied to the high-pressure discharge lamp from the lighting device and includes a frequency variance controlling section which supplies a low-frequency driving current having a low frequency and two or more types of high-frequency driving currents having frequencies higher than the low frequency to the high-pressure discharge lamp.

In the first display mode, a first tone converting circuit and a second tone converting circuit of a control LSI divide one frame period of an input image signal into a plurality of sub-frame periods to perform output to a display panel, thus realizing image display performed by time-division driving (pseudo-impulse driving). In the second display mode, the control LSI directly outputs an input image signal to the display panel, thus realizing image display performed by hold driving. In at least one embodiment, switching between the first display mode and the second display mode is performed by changing output of an output data selector according to a mode switching signal. This realizes an image display apparatus which effectively obtains the effect of suppressing blurring of a moving image and alleviates the problem of flickers caused by pseudo-impulse driving.

The polarity inversion cycle of a voltage applied to a liquid crystal layer is set to at least 2-frame cycle, or more preferably to as long as about 10 sec. Accordingly, a flicker that could not have been prevented at a polarity inversion cycle of about one frame can be prevented, and a longer inversion cycle can reduce power consumption. A material low in ion reactivity and small in residual polarization is used as a liquid crystal material or an orientation film material, thereby preventing the occurrence of a residual DC component in a liquid crystal layer and the deterioration of display quality despite a longer polarity inversion cycle. In the case of an LCD provided with a minimal transmittance with respect to an applied voltage, black can be accurately displayed by, for example, regulating a common electrode potential so that an applied voltage at which the transmittance of a liquid crystal shows a minimum value during an anodic application period is equal to that during a cathodic application period.

An electro-optical device includes: a plurality of scanning lines; a plurality of data lines; and a plurality of pixels that are provided at positions corresponding to intersections of the scanning lines and the data lines and include pixels each having a red color filter and pixels each having a blue color filter. A plurality of frames are set as a reference frame, the pixels are displayed with either a first gray-scale or a second gray-scale whose level is higher than that of the first gray-scale by one gray-scale level, in each frame, and image signals are supplied to the plurality of data lines such that adjacent pixels nave phases opposite to each other at a spatial frequency among the pixels each having the red color filter and the pixels each having the blue color filter.

Viewing angle characteristics on the entire display surface are improved while suppressing harmful effects such as flicker and banding caused by viewing angle improvement control. A liquid crystal display apparatus (1) includes: a liquid crystal panel (11) which includes a plurality of pixels arranged in a matrix; a drive control unit (24) which performs viewing angle improvement processing by converting a gradation of a video signal input to the pixel; and a processing object determination unit (22) which determines whether or not an image displayed on each of the pixels of the liquid crystal panel (11) is an image having an intermediate color. The drive control unit (24) is configured to perform the viewing angle improvement processing on the pixel determined by the processing object determination unit (22) such that the pixel displays the image having the intermediate color.

There is provided a display device including a first measurement portion that measures information relating to luminance of a first image signal, and outputs a first measurement result, a second measurement portion that measures information relating to luminance of a second image signal, and outputs a second measurement result, a comparison portion that compares the first measurement result with the second measurement result and outputs differential data, a correction amount determination portion that determines, based on the differential data, a correction amount for at least one of the first image signal and the second image signal and a correction portion that corrects, based on the correction amount, the luminance of at least one of the first image signal and the second image signal.

A discharge lamp lighting apparatus comprising a d.c. power source section which rectifies and smoothes an a.c. voltage; a current detecting circuit which detects a current which flows through a discharge lamp; a power source ripple detecting circuit which detects a voltage change of power supplied from the d.c, power source section and outputs a voltage obtained by superimposing the detected voltage over a detected voltage which is available from the current detecting circuit; and a control circuit which controls, based on) the output voltage from the power source ripple detecting circuit, an output voltage to the discharge lamp so that the current flowing through the discharge lamp becomes a constant current. A rate of superimposition of the output voltage from the power source ripple detecting circuit may be switched in accordance with the discharge lamp voltage.

To provide a light source unit which prevents a reduction of light emitting efficiency in a luminescent material layer and a projector, a projector includes a light source unit, a display device and a projector control device, the light source unit includes an excitation light shining device, a luminescent wheel on which a luminescent material layer is laid circumferentially which receives the excitation light to emit luminescent light of a predetermined wavelength band, two types of light source devices for emitting light rays of wavelength bands which are different from the predetermined wavelength band, and a light source control device for controlling individually the emission of light by the excitation light shining device and the two types of light source devices and for controlling the rotating speed of the luminescent wheel in accordance with a period of time when the excitation light shining device is turned on.

The invention discloses a method and a system for dynamic backlight local control liquid crystal display. The method comprises the following steps of: inputting video signal images; calculating pixel luminance of the input images; calculating local luminance representative values of the input images; calculating backlight local control values on the basis of the local luminance representative values of the images and backlight distribution characteristics; calculating backlight luminance values on the basis of the backlight local control values and the backlight distribution characteristics; compensating the input images on the basis of the backlight luminance values; outputting the backlight local control values to control the backlight luminance; and outputting the compensated video signal images. According to the method and the system, the power consumption of liquid crystal display devices can be reduced to a great extent; the dynamic contrast and the static contrast of the displayed images are improved to display in a high dynamic range; the color saturation is high, and colors have high fidelity; and the image detail expressive capability of the images is obviously improved. In addition, according to the method and the system, the problem of image quality brought by dynamic backlight liquid crystal display is effectively solved, inter-frame flicking is inhibited, and image artifact is prevented.

A liquid crystal display device is provided which improves quality of images made up of moving images and images having moving images and still images in a mixed manner. Each frame of an input video signal having a specified frame frequency (60 Hz) is divided into four sub-frames each having a frequency being four times as large as the specified frame frequency and, after an overdriving operation is performed in the first sub-frame on each pixel region of a liquid crystal display panel, a normal driving operation is performed in the second sub-frame and thereafter, and in which a backlight flashes two times at a frequency being two times as large as a frame frequency (120 Hz) of the first frame frequency during one frame period in specified time intervals.

A lighting device for high-pressure discharge lamp for lighting the high-pressure discharge lamp by lowering or raising a DC voltage applied to an input side by a DC / DC converter circuit, then converting the DC power into an AC power by a DC / AC inverter circuit, supplying the AC power to the high-pressure discharge lamp and lighting the high-pressure discharge lamp, wherein when the polarity of the current of the high-pressure discharge lamp lit by the substantially rectangular wave is inverted, the output voltage of the DC / DC converter circuit is set to 1.5 times or more as large as the voltage at the stable lighting time of the high-pressure discharge lamp.

An object of the invention is to provide method of operating a projection-type system, which method is capable of suppressing flicker and minimizing gradation disorder at the same time by superimposing a pulse current on a d.c. lamp current to stabilize arc while synchronizing the superimposition of the pulse current on the d.c. lamp current with a predetermined segment. The method of operating a projection-type system configured to pass light emitted from a high-pressure discharge lamp lit by d.c. lighting through divided plural color segments sequentially to project an image onto a screen, includes superimposing a pulse current on a d.c. lamp current in the high-pressure discharge lamp in synchronism with at least one specific color segment.

In a current driving display device, a first operation in which pixel circuits in the odd rows are sequentially scanned to set a current supplied to display elements and a second operation in which pixel circuits in the even rows are sequentially scanned to set a current supplied to display elements are alternately repeated. The current set in the pixel circuits is supplied to the display elements in parallel with the first and the second operations, the number of times in the period is twice or more than the number of times in which the pixel circuit sets a current supplied to the display element. Flickers are suppressed.

Disclosed herein is an image display apparatus, including: a plurality of scanning lines extending along rows and configured to successively supply a control signal in synchronism with a horizontal period in order to perform line-sequential scanning over one field; a plurality of signal lines extending along columns and configured to supply an image signal in accordance with the line-sequential scanning; and a plurality of pixel circuits disposed at locations at which the scanning lines and the signal lines intersect with each other and configured to form a screen.

A picture electrode of an MVA liquid crystal display device has a configuration where sub-picture electrodes are successively provided, while a cross-shaped slit is provided as an alignment restriction member on a common electrode of the side of a counter substrate. A columnar spacer is provided on a signal line of a TFT substrate in conformity to a position of a singular point of an alignment of liquid crystal molecules, the singularity occurring in a display region. This structure makes it possible, when a panel surface is depressed, to cause quick re-aligning of the liquid crystal molecules at the singular point of +1, as a base point, which has occurred at a center of the cross-shaped slit and in the vicinity of the columnar spacer, hence achieving a speedy recovery of displaying.

In one embodiment of the present invention, an active-matrix type display unit, and a drive method thereof are disclosed. Gate-bus lines are provided at both top and bottom sides of each row. Two sub-pixels are formed at a region surrounded by two adjacent source-bus lines and two adjacent gate-bus lines. At the odd-numbered rows, for the left-side sub-pixel of those two sub-pixels, a scanning signal is supplied from the top-side gate-bus line, while a video signal is supplied from the left-side source-bus line. For the right-side sub-pixel, on the contrary, a scanning signal is supplied from the bottom-side gate-bus line, while a video signal is supplied from the right-side source-bus line. At the even-numbered rows, the gate-bus line from which a scanning signal is supplied is reversed to the case of the odd-numbered rows. The gate-bus lines are sequentially selected one by one, and all the video signal polarities are made the same during each horizontal scanning period.

In the display device and the display method of the present invention, a scanning signal line driving circuit controls falls of a scanning signal line, so as to make level shifts occurring to pixel potentials substantially uniform throughout display plane, the level shifts being caused by parasitic capacitances which parasitically exist in scanning signal lines. Fall waveforms of the scanning signal change at a change rate Sx which is a change quantity per unit time, and by desirably setting the change rate Sx, a change rate Sx1 in the vicinity of an input-side end of the scanning signal line and a change rate SxN in the vicinity of the other end thereof are substantially equal to each other, not being influenced by signal delay transmission characteristic which the scanning signal line possesses, like scanning signal line waveforms Vg(1, j) and Vg(N, j).

In the display device and the display method of the present invention, a scanning signal line driving circuit controls falls of a scanning signal line, so as to make level shifts occurring to pixel potentials substantially uniform throughout display plane, the level shifts being caused by parasitic capacitances which parasitically exist in scanning signal lines. Fall waveforms of the scanning signal change at a change rate Sx which is a change quantity per unit time, and by desirably setting the change rate Sx, a change rate Sxl in the vicinity of an input-side end of the scanning signal line and a change rate SxN in the vicinity of the other end thereof are substantially equal to each other, not being influenced by signal delay transmission characteristic which the scanning signal line possesses, like scanning signal line waveforms Vg(1, j) and Vg(N, j).

A gradation voltage adjustment section for increasing a positive gradation voltage VHX of an X-th gradation and a negative gradation voltage of the X-th gradation so that the increment corresponds to a charge pull-in amount ΔV is provided in a gradation voltage generation circuit of each source driver. In at least one embodiment, a center value between the positive and negative gradation voltages is adjusted for each driver in accordance with a slant of the charge pull-in amount ΔV in a direction of a gate signal line, thereby suppressing a flicker without varying a gradation characteristic. Further, a center value between the positive and negative gradation voltages is adjusted for each horizontal line or for every plural lines in a single frame in accordance with a horizontal direction deviation and a vertical direction deviation of the charge pull-in amount ΔV in a transfer block, thereby suppressing a flicker without varying a gradation characteristic.