33results about How to "Difference in luminance" patented technology

A liquid crystal device having a display section provided with a plurality of X electrodes and a plurality of Y electrodes, a master X driver IC and a slave X driver IC for driving the X electrodes, and a Y driver for driving the Y electrodes. The master IC has a display control signal generation section which generates a display control signal based on a signal from an external MPU and an output terminal (or input / output terminal) which outputs the display control signal. Each of the master IC and slave IC has an input terminal for receiving the display control signal from the master IC through an external wiring. This liquid crystal device can eliminate a luminance difference within the display screen driven by the master IC and the slave IC.

Each pixel includes first and second subpixels and two switching elements provided for those subpixels. Each subpixel includes a liquid crystal capacitor and a storage capacitor. The storage capacitor counter electrodes of the first and second subpixels are electrically independent. A storage capacitor counter voltage applied to each storage capacitor counter electrode by way of its associated storage capacitor line has a first period (A) with a first waveform during one vertical scanning period. The first waveform oscillates between multiple voltage levels in a first cycle time (PA) that is an integral number of times (and at least four times) as long as one horizontal scanning period (H). Each of the voltage levels has a flat portion with a duration TP. While the two switching elements are ON, a display signal voltage is applied to the respective subpixel electrodes and respective storage capacitor electrodes of the first and second subpixels. After the two switching elements have been turned OFF, voltages at the storage capacitor counter electrodes of the first and second subpixels change. And if an interval between a point in time when the two switching elements in ON state have just been turned OFF and a point in time when the storage capacitor counter voltage changes for the first time is βH, TP / 4≦β<3·TP / 4 is satisfied. Consequently, even if a still picture is presented, the difference in luminance between the subpixels is hardly sensible as unevenness, thus achieving good display quality.

A method for driving a display device includes: dividing an entire gray-scale region corresponding to a data gray scale into a first gray-scale region and a second gray-scale region and setting a first gamma value of the first gray-scale region and a second gamma value of the second gray-scale region, the first gamma value being smaller than the second gamma value; providing a first gray-scale display voltage corresponding to the data gray scale to a display panel during a first section of one horizontal period by using the first gamma value or the second gamma value selected by an inputted data gray scale; and providing a second gray-scale display voltage corresponding to a black gray scale to the display panel during a second section of the one horizontal period.

This invention presents a YUV to RGB conversion method which preserves high precision of luminance information in an original YUV image signal when converting it to RGB signal. The method can be used to convert the original YUV signal to arbitrary quantization levels in RGB space. In addition, this invention presents methods of pre-quantization and re-quantization as to compensate conventional YUV to RGB color conversion.

Disclosed herein is an active-matrix display apparatus, wherein if any particular one of N light emitting sub-devices pertaining to any specific one of pixel circuits is defective, the particular light emitting sub-device is electrically disconnected from the specific pixel circuit and the magnitude of a driving current supplied to the (N−1) remaining light emitting sub-devices pertaining to the specific pixel circuit is adjusted so that the (N−1) remaining light emitting sub-devices receive a driving current from a device driving transistor with a magnitude suppressed to a value equal to ((N−1) / N) times the magnitude of a driving current which is supplied to a normal pixel circuit not including a defective light emitting sub-device.

A liquid crystal display device includes a liquid crystal display panel, a light source configured to provide the liquid crystal display panel with a light, a vertical blank detector circuit configured to calculate a counting value of a vertical blank period of a frame by counting a synchronization signal, a luminance correction value calculator circuit configured to calculate a luminance correction value by comparing the counting value of the vertical blank period with a plurality of reference counting values, and a light source driver configured to generate a light source driving signal and provide the light source driving signal to the light source. The light source driving signal has a normal level corresponding to a normal luminance value in an active period of the frame and has a correction level corresponding to the luminance correction value in the vertical blank period of the frame.

A display apparatus includes a display panel comprising a plurality of gate lines connected to a plurality of pixel rows, a plurality of data lines connected to a plurality of a pixel columns, at least one dummy pixel row disposed in a peripheral area surrounding a display area in which the plurality of pixel rows and the plurality of a pixel columns are disposed, and at least one dummy gate line connected to the dummy pixel row and a data driver circuit configured to provide the dummy pixel row with a dummy data signal, the dummy data signal having a level that differs from a data signal of a pixel column adjacent to the dummy pixel row.

The image display quality is improved by reducing the afterimage phenomenon of a display image on a plasma display panel. For this purpose, the image display region of the panel is divided into a plurality of regions, the difference between the luminance gradation value in the present field and that in the field immediately before the present field is calculated as the inter-field luminance difference. Then, the number of pixels where the inter-field luminance difference is lower than a predetermined luminance comparison value is counted, and the counting result is set as a first count value. The number of edges where the difference between the luminance gradation values of adjacent pixels is equal to a predetermined edge comparison value or larger is counted, and the counting result is set as a second count value. The afterimage strength level region is calculated based on the first and second count values.

To provide a video signal processing apparatus capable of generating video signals that enable displaying and recording of a high-quality picture. A video signal processing apparatus according to an embodiment of the present invention includes a decoder decoding an input TS to generate a video signal having a field frequency fv of 60 Hz or a video signal having a field frequency fv of 59.94 Hz, and a converter converting the respective video signals into NTSC video signals having a color subcarrier the phase of which is inverted for each frame.

Provided is a liquid crystal display device with which it is possible to suppress degradation of image quality during video display or three-dimensional display without causing gradational luminance irregularities. Writing of an image to be displayed is sequentially performed from one side of a panel to the other side thereof during each frame period, and writing of a black image is sequentially performed from the one side of the panel to the other side thereof during the vertical blanking period in each frame period. A plurality of LEDs composing a backlight are divided into a plurality of segments so that a group of LEDs arrayed in a line in the direction in which scanning signal lines extend belong to the same segment. A segment lighting control circuit in a backlight control circuit controls emission intensities of the LEDs segment by segment so that the intensity of light irradiating the panel increases gradually from the one side of the panel to the other side thereof.

Disclosed herein is a display device including a pixel array configured to include pixel circuits arranged in a matrix having a light emitting element, driving transistor, sampling transistor, and hold capacitor. The display device further includes a signal selector, driving control scanner, and writing scanner. The signal selector alternately carries out supply of a video signal voltage in order from a beginning line to an end line in a unit and supply of a video signal voltage in order from an end line to a beginning line in a unit. The writing scanner outputs the pulse to the writing control lines in such a way that input of a video signal voltage in order from a beginning line to an end line in a unit and input of a video signal voltage in order from an end line to a beginning line in a unit are alternately carried out.

A display device includes a substrate, a gate line connected to a gate driver, a reference voltage line, a data line crossing the gate line and the reference voltage line, a first thin film transistor including a first drain electrode and connected to the gate line and the data line, a second thin film transistor including a second drain electrode, a third thin film transistor connected to the gate line, the reference voltage line, and the second thin film transistor, and a pixel electrode including a first sub-pixel electrode connected to the first thin film transistor and a second sub-pixel electrode connected to the second thin film transistor. The first drain electrode overlaps the reference voltage line, and an area of a region in which the first drain electrode and the reference voltage line overlap each other increases in a direction toward the gate driver.

A display apparatus includes a display panel comprising a plurality of gate lines connected to a plurality of pixel rows, a plurality of data lines connected to a plurality of a pixel columns, at least one dummy pixel row disposed in a peripheral area surrounding a display area in which the plurality of pixel rows and the plurality of a pixel columns are disposed, and at least one dummy gate line connected to the dummy pixel row and a data driver circuit configured to provide the dummy pixel row with a dummy data signal, the dummy data signal having a level that differs from a data signal of a pixel column adjacent to the dummy pixel row.

An error diffusion method and apparatus using an area ratio of candidate colors in a CMYKRGBW cube, wherein the candidate colors are determined in response to an input value, and the CMYKRGBW cube is converted into a color space consisting of only four colors so that the candidate colors can be evenly distributed. The color space is then expressed using the area ratio of the candidate colors. Accordingly, it is possible to evenly distribute candidate colors in all gray-scale regions, including a highlight region, thereby obtaining a soft image that does not have a pattern that is strenuous on the eye of an observer.

In a video display apparatus, a backlight for illuminating a liquid crystal panel is segmented into a plurality of areas. A frequency distribution processing unit calculates a dark pixel amount from the frequency distribution of the gradation values of pixels in a video image. A backlight control unit calculates a lower limit of luminance in each area included in the backlight so that the lower limit increases as the dark pixel amount becomes smaller. The backlight control unit adjusts the luminance in each area individually according to the gradation values in each portion of the video image, and adjusts the luminance in an area where the luminance is less than the lower limit to the lower limit. The difference in luminance between the areas illuminating dark portions of the video image is decreased, and the occurrence of luminance blur resulting from the difference in luminance between the areas is reduced.

Provided is a display device for carrying out seamless display so that a sense of strangeness is not given to a viewer or the sense of strangeness is reduced. In at least one example embodiment, a display device that displays an image based on image signals DAT, includes: a display panel having (i) a display area in which a plurality of display elements for displaying the image are disposed in a matrix and (ii) a frame area which is located at an end of the display panel and in which no display element is provided; a backlight device which emits light, in a form of plane emission, towards a surface opposite to a display surface of the display area; and a light guide element which is provided on the display panel and which changes a light path of part of light emitted from the plurality of display elements so that the part of light is guided to the frame area, and luminance per unit area in a light-emitting surface of the backlight device is larger in a display area end portion where the light guide element is provided than in a normal display area where the light guide element is not provided out of the display area.

A liquid crystal display includes: a first substrate and an opposing second substrate; an alignment layer formed on the first substrate and the second substrate; and a liquid crystal layer interposed between the first substrate and the second substrate. The alignment layer includes a copolymer including a dianhydride monomer and a diamine monomer.

A liquid crystal display device includes a liquid crystal display panel, a light source configured to provide the liquid crystal display panel with a light, a vertical blank detector circuit configured to calculate a counting value of a vertical blank period of a frame by counting a synchronization signal, a luminance correction value calculator circuit configured to calculate a luminance correction value by comparing the counting value of the vertical blank period with a plurality of reference counting values, and a light source driver configured to generate a light source driving signal and provide the light source driving signal to the light source. The light source driving signal has a normal level corresponding to a normal luminance value in an active period of the frame and has a correction level corresponding to the luminance correction value in the vertical blank period of the frame.

A point light source includes a body, a light-emitting unit and a fluorescent unit. The body includes a bottom portion and a protrusion portion protruded from the bottom portion. The light-emitting unit includes a light-emitting chip disposed at the protrusion to have an inclined-angle with respect to the bottom portion. The fluorescent unit covers the bottom portion, the protrusion portion and the light-emitting chip. The point light source has an emitting-angle of about 180 degrees and luminance difference between a bright-portion and a dark-portion is decreased to enhance display quality of a display device.

A backlight module that includes a lamp and a single side driving inverter that is coupled to one end of the lamp. The single side driving inverter is configured to control an operating current of the lamp to be within 80% to 100% of a saturation luminance current. The lamp has a characteristic such that when the operating current is lower than the saturation luminance current, the lamp luminance increases as the operating current increases, and when the operating current is substantially equal to or higher than the saturation luminance current, the lamp luminance does not increase as the operating current increases.

An electronic device includes a display module, a base and a keyboard module. The display module is pivoted on the base. The keyboard module is disposed on the base. The keyboard module has a plurality of keys. Each of the keys includes a main body and an imprinted structure. The main body has a top surface. The imprinted structure is disposed on the top surface of the main body and includes a light guiding portion and a light scattering portion. A light emitted by the display module illuminates the keyboard module. The light is guided towards a specific direction when the light passes through the light guiding portion, and the light is scattered in other directions when the light passes through the light scattering portion.

Each pixel includes first and second subpixels and two switching elements provided for those subpixels. Each subpixel includes a liquid crystal capacitor and a storage capacitor. The storage capacitor counter electrodes of the first and second subpixels are electrically independent. A storage capacitor counter voltage applied to each storage capacitor counter electrode by way of its associated storage capacitor line has a first period (A) with a first waveform during one vertical scanning period. The first waveform oscillates between multiple voltage levels in a first cycle time (PA) that is an integral number of times (and at least four times) as long as one horizontal scanning period (H). Each of the voltage levels has a flat portion with a duration TP. While the two switching elements are ON, a display signal voltage is applied to the respective subpixel electrodes and respective storage capacitor electrodes of the first and second subpixels. After the two switching elements have been turned OFF, voltages at the storage capacitor counter electrodes of the first and second subpixels change. And if an interval between a point in time when the two switching elements in ON state have just been turned OFF and a point in time when the storage capacitor counter voltage changes for the first time is βH, TP / 4≦β<3·TP / 4 is satisfied. Consequently, even if a still picture is presented, the difference in luminance between the subpixels is hardly sensible as unevenness, thus achieving good display quality.

In a driving method of a plasma display panel of the present invention, plural display electrode pairs are divided into plural display electrode pair groups and one field is divided into plural sub-fields. The length of the sustain period is compared to the length of the erase period. If the sustain period is longer than the erase period, sustain discharge and erase discharge are performed for each of the display electrode pair groups, while if the sustain period is shorter than the erase period, sustain discharge and erase discharge of one display electrode pair group are synchronized with those of another display electrode pair group. For a sub-field with a largest luminance weight or a sub-field with a highest lighting ratio, sustain discharge and erase discharge of one display electrode pair group are synchronized with those of another display electrode pair group without fail.

In the present invention, there is provided a display panel driving method of the type wherein the total light emitting period length within a one-field period is controlled to variably control the peak luminance level of a display panel, the driving method including a step of variably controlling, where the one-field period has N light emitting periods disposed therein, N being equal to or greater than 2, the light emitting period length of a particular one of the light emitting periods and the other light emitting period or periods to provide a difference in luminance between the particular light emitting period and the other light emitting period or periods so that the particular light emitting period is visually observed as the center of light emission.

A plasma display panel has an improved display electrode, thereby enhancing emission luminance. The plasma display panel includes a front substrate and a rear substrate that face each other and between which a space is formed, barrier ribs that define a plurality of discharge cells in the space between the front substrate and the rear substrate, address electrodes that extend in a first direction to intersect the discharge cells, phosphor layers that are respectively formed within the discharge cells, and first electrodes and second electrodes having linear portions that are formed in a second direction to intersect the first direction and protruded portions that extend in the first direction from the linear portions and face each other in the second direction within the discharge cells so as to form discharge gaps, respectively.

A display device includes: a pixel unit including first pixels disposed in a first pixel area and second pixels disposed in a second pixel area; an image data corrector adjusting a limit grayscale of first image data corresponding to the first pixel area based on a dimming level defining a maximum luminance at which the pixel unit is able to emit light, and correcting the first image data based on the limit grayscale; a data driver supplying data signals to the pixel unit based on the corrected first image data and second image data corresponding to the second pixel area; and a scan driver supplying scan signals to the pixel unit.

A liquid crystal display includes: a first substrate and an opposing second substrate; an alignment layer formed on the first substrate and the second substrate; and a liquid crystal layer interposed between the first substrate and the second substrate. The alignment layer includes a copolymer including a dianhydride monomer and a diamine monomer.

Disclosed herein is an active-matrix display apparatus, wherein if any particular one of N light emitting sub-devices pertaining to any specific one of pixel circuits is defective, the particular light emitting sub-device is electrically disconnected from the specific pixel circuit and the magnitude of a driving current supplied to the (N−1) remaining light emitting sub-devices pertaining to the specific pixel circuit is adjusted so that the (N−1) remaining light emitting sub-devices receive a driving current from a device driving transistor with a magnitude suppressed to a value equal to ((N−1) / N) times the magnitude of a driving current which is supplied to a normal pixel circuit not including a defective light emitting sub-device.

A plasma display panel driving method in which a reset step and an address step are sequentially executed in the first subfield and second subfield of each field. A microemission step is executed in the first subfield for generating a microemission discharge between ones of the row electrodes and the column electrodes in display cells in the ON mode by applying a voltage for using the ones of the row electrodes as the anode and the column electrodes as the cathode, between the electrodes immediately after the address step. Moreover, in the microemission step, a potential lower than the voltage generated when applying a sustain pulse is respectively applied to the ones and the others of the row electrodes while applying a voltage as described above between the ones of the row electrodes and the column electrodes.