Sharp Kabushiki Kaisha Corporation

Kyocera Mita Corporation

Ken Inada

Asahi Yamato

Taketoshi Nakano

Toshihiro Yanagi

Akizumi Fujioka

Fumiyuki Kobayashi

Hiroyuki Furukawa

Hidekazu Miyata

Yasuhiro Yoshida

Kazuyoshi Yoshiyama

Kohzoh Takahashi

Shinji Nakagawa

Takuya Tsuda

Kohji Saitoh

Kazuki Takahashi

Takafumi Kawaguchi

Jun Nakata

Maki Sasagawa

The occurrence of flicker is effectively suppressed particularly in a liquid crystal display device that performs low-frequency driving. Provided are a gradation-to-voltage value conversion table for converting a gradation to a voltage value, a correction value map for storing a correction value, and a voltage value-to-gradation conversion table for converting a voltage value to a gradation. A gradation of an input image signal is converted to a first voltage value, using the gradation-to-voltage value conversion table. The correction value specified in accordance with a location of a pixel to be processed is added to or subtracted from the first voltage value so that a second voltage value is obtained. The second voltage value is converted to an output gradation, using the voltage value-to-gradation conversion table. A driving video signal is applied to a source bus line, based on the output gradation.

Liquid crystal display device and method for driving same

A liquid crystal display device that performs intermittent driving involving a driving period and an idle period includes a gray scale level control unit that generates, from an input image signal, an image signal for display and an image signal for correction. A signal line control unit writes the image signal for correction to the plurality of signal lines before writing the image signal for display during a driving period. An LUT stores a correction gray scale value associated with a gray scale value of at least a current frame. An adding circuit corrects the input image signal based on the correction gray scale value read from the LUT. The subtracting circuit specifies, in a pixel region, a regular image pattern including at least a first pixel and a second pixel and changes an output from the adding circuit for the first image by a predetermined gray scale width.

Liquid crystal display device and method of driving the same

The invention provides a liquid crystal display device capable of preventing a reduction in display quality by suppressing the occurrence of flicker during alternating-voltage drive, as well as a method for driving the same. Overshoot drive is performed during a first frame period, which is shortened to such an extent that a 'positive effective area' and a 'negative effective area' are approximately equal in size. The duration of the first frame period is set to be greater than or equal to a quarter of one frame period at a refresh rate of 60 Hz but less than one frame period. This renders it possible to make adjustments such that luminance is inhibited from abruptly dropping immediately after a polarity change, and also luminance is prevented from becoming excessively high due to overshoot drive, and therefore, the occurrence of flicker due to flexoelectric polarization during alternating-voltage drive can be suppressed.

Liquid crystal display device and driving method therefor

The present invention provides a liquid crystal display device capable of suppressing a decrease in display quality when pause drive is performed in an alternating-voltage drive mode, as well as a method for driving the same. In a first drive frame, overshoot drive is performed using correction values provided by an LUT to apply overshoot voltages whose absolute values are higher than absolute values of signal voltages to data signal lines. Subsequently, in a second drive frame, normal drive is performed to write signal voltages of the same polarity as the overshoot drive voltages to the data signal lines. Thereafter, a pause period in which an image written by normal drive is displayed continues until the start of a drive period in the next pause drive period. As a result, a decrease in luminance immediately after the signal voltages are written during the second drive frame is suppressed significantly, so that the viewer barely recognizes flicker.

There is provided an image display device, in which a pixel includes sub-pixels of four or more colors that include a color in addition to the three primary colors, and which can display a high-quality image in which false colors or artifacts are suppressed. The image display device includes a pixel area in which a plurality of pixels P are arranged in a matrix shape, and each of the pixels P includes m (m is an integer which is equal to or greater than 4) sub-pixels SP. When it is assumed that the colors of the m sub-pixels SP included in one pixel are C, C, . . . , and Cm, the m sub-pixels SP which are sequentially arrayed from an arbitrary position include all of the colors of C, C, . . . , and Cm in both the vertical direction and the horizontal direction in the pixel area.

Image display device

Grayscale values for previous and current frames are different, and therefore, an overshoot voltage, which has a higher absolute value than a signal voltage, are applied to a data signal line. Next, in a second drive frame, normal drive is performed, so that a signal voltage of the same polarity as the overshoot voltage is written to the data signal line. Moreover, in a first drive frame of a third pause drive period, the grayscale values for the previous and current frames are equal, and also greater than or equal to a boundary value, and therefore, undershoot drive is performed. An undershoot voltage, which has a lower absolute value than a signal voltage, is applied to the data signal line. Next, in a second drive frame, normal drive is performed, so that a signal voltage of the same polarity as the undershoot voltage is written to the data signal line.

An image determination part configured to determine whether or not an image based on an input image signal is an image analogous to a polarity reversal pattern in a reversal driving scheme employed by default and to output a determination result, and a reversal pattern decision part configured to decide a reversal driving scheme based on the determination result are provided as constituent elements anterior to a liquid crystal drive unit. With regard to each unit area where the determination by the image determination part is made, the reversal pattern decision part decides the reversal driving scheme in the unit area, as a reversal driving scheme different from the reversal driving scheme employed by default, when the determination result indicates that the image based on the input image signal is the image analogous to the polarity reversal pattern in the reversal driving scheme employed by default.

In first and second display devices () both during pause drive (intermittent drive), an instantaneous increase in consumption power is suppressed by means of a configuration to perform control such that the scanning period in one of the two display panels is inserted during the scanning-stopped period in the other display panel, namely during the drive operation (for writing into the pixel circuit) of one of the two display panels, the drive operation (for writing) of the other display panel is not performed. Accordingly, even when a limit value of a current supply capability of a battery is low, the display device can be driven, so that a battery service life is prolonged and the operable time of a portable terminal () at the time of driving by the battery is increased.

Display device and display method

There is provided an image display device, in which a pixel includes sub-pixels of four or more colors that include a color in addition to the three primary colors, and which can display a high-quality image in which false colors or artifacts are suppressed. The image display device includes a pixel area in which a plurality of pixels P are arranged in a matrix shape, and each of the pixels P includes m (m is an integer which is equal to or greater than 4) sub-pixels SP. When it is assumed that the colors of the m sub-pixels SP included in one pixel are C1, C2, . . . , and Cm, the m sub-pixels SP which are sequentially arrayed from an arbitrary position include all of the colors of C1, C2, . . . , and Cm in both the vertical direction and the horizontal direction in the pixel area.

There is provided a display device capable of suppressing brightness change which can occur at the time of image update in intermission driving. A display control circuit () includes a frame memory (), a coercive refreshing determination section (), a refreshing circuit (), and an undershoot circuit (). The coercive refreshing determination section () outputs an active coercive refreshing signal and an active correction instruction signal upon determining that an image is updated. The refreshing circuit () receives the active coercive refreshing signal, and then outputs an active output control signal. The frame memory () receives the active output control signal, and then outputs an image data. The undershoot circuit () performs, if in reception of the active correction instruction signal, a correction by making a subtracting operation to the image data received from the frame memory (), and then outputs corrected image data.

Display device and method for driving the same

An LCD device includes: an LC panel which exhibits different gamma curves under different view angles, and a display control circuit which divides a single frame period into first and second display periods and divides a display region of the LC panel into first and second regions. The display control circuit has a luminance computing section which computes A to D so that A to D satisfies A+C=B+D and A&#x2260;B&#x2260;D as well as C&#x2260;B&#x2260;D, where A and C are gray-level luminances, A and B are the white luminances of pixel data displayed in the first and second regions, respectively, during the first display period, and C and D are the white luminances of pixel data displayed in the first and second regions, respectively, during the second display period.

Liquid crystal display, display method, program, and recording medium

Disclosed is a display device that (i) converts an input image formed of R, G, and B into a converted image formed of R, G, B, and W to display the converted image and that (ii) compresses the luminance of an input image for the subsequent frame on the basis of an adjustment value C which is corrected in correspondence with the number of, among all pixels in a converted image for the current frame, pixels in a state of luminance saturation and that then converts the input image into a converted image, the display device including a luminance oscillation detecting section () for detecting, while input images identical to each other are being inputted each as the above input image, whether converted images corresponding to the respective input images have an oscillating luminance, the display device, in the case where the luminance oscillation detecting section () has detected that the converted images have an oscillating luminance, stopping correction of the adjustment value C to fix the adjustment value C to a certain value, thereby preventing the converted images from having an oscillating luminance as a result of oscillation of the adjustment value C.

Display device and control method for display device

A display device includes a display panel having pixels each constituted by red, green, blue, and white subpixels and a backlight, further including: a grayscale ratio calculating section acquiring RGB data and calculating a ratio of the lowest to the highest of RGB grayscales in each pixel; a detection section detecting, from the RGB data, a ratio of the number of target pixels in one frame; a conversion coefficient calculating section acquiring, by using the detected ratio, a conversion coefficient for converting the RGB data into RGBW data; a RGB data conversion section converting the RGB data into the RGBW data per pixel by using the conversion coefficient; and a display control section generating, from the RGBW data, an image to be displayed on the display panel and causing the display panel to display the image.

Display device, method for controlling display device, program, and recording medium

In an intermittent drive mode of a display device in which driving and pausing of the driving are repeated, an image identification section identifies an input image as a still image or a moving image. In a case where the moving image is identified, a drive/pause control section generates a drive/pause control signal with a period ratio in accordance with the moving image. A timing control section generates a driver control signal so that intermittent driving is carried out. Then, a source driver and a gate driver drives a display section so that the drive period and the pause period are repeated with a predetermined period ratio, so that the input image is displayed. The drive/pause control section sets a time ratio between the drive period and the pause period to be variable for each of the moving image and the still image.

Display device and method for driving same

A liquid crystal display device has pixels containing first to fourth subpixels ('SPs') having four different colors, respectively, arranged in a two-by-two matrix. In displaying a font on a pixel composed of three SPs having three different colors, respectively, arranged in three columns of stripes, the SP in the first column of stripes takes on a tone Tx, the SP in the second column of stripes takes on a tone Ty, and the SP in the third column of stripes takes on a tone Tz. Each of the first and fourth SPs takes on a tone which is obtained by performing rounding on (Tx&#xd7;&#x2154;)+(Ty&#xd7;&#x2153;)=p and that each of the second and third SPs takes on a tone which is obtained by performing rounding on (Ty&#xd7;&#x2153;)+(Tz&#xd7;&#x2154;)=v.

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Osaka, Japan

Ken Inada