Sharp Kabushiki Kaisha Corporation

Takuya Sone

Noriyuki Tanaka

Kouji Kumada

Tatsuhiko Suyama

Norio Ohmura

Jin Miyazawa

Kazuo Nakamura

Daiji Kitagawa

Kentaroh Uemura

The power consumption of an apparatus including a touch panel is reduced. In a touch panel control device () including a sensor drive section () and a liquid crystal drive controller (), the sensor drive section () makes a detection sensitivity during a pause period lower than a detection sensitivity during an update period, the pause period being a period in which the liquid crystal drive controller () does not update the image that is displayed on a liquid crystal display panel (), the update period being a period in which the liquid crystal drive controller () updates the image that is displayed on the liquid crystal display panel ().

Touch panel control device and information processing apparatus

In the present invention, occurrence of abnormality such as display misalignment at the time of image update is prevented even when pause drive is performed in a display device where data signal lines are driven by a plurality of driver ICs. In a liquid crystal display device which includes a master IC (L) and a slave IC (R) as driver ICs and performs pause drive, upon detection of refresh start timing by a REF (Half) of the master IC (L), the master IC (L) transmits a refresh control signal RfC to the slave IC (R), and upon receipt of a refresh detection signal RfD indicating refresh start timing detected by a REF (Half) of the slave IC (R), the master IC (L) transmits the refresh control signal RfC to the slave IC (R) as well as starts refreshing on the left active area based on data in a 1/2 RAM (L). Upon receipt of the refresh control signal RfC, the slave IC (R) starts refreshing on a right active area based on data in a 1/2 RAM (R).

Display device and method for driving same

An object of the present invention is to prevent occurrence of abnormality such as display misalignment at the time of image update even when pause drive is performed in a display device where data signal lines are driven by a plurality of driver ICs. In a liquid crystal display device which includes a master IC (L) and a slave IC (R) as driver ICs and performs pause drive, upon detection of refresh start timing by a REF (Half) of the master IC (L), the master IC (L) transmits a refresh control signal RfC to the slave IC (R), and starts refreshing a left active area of a display portion. Upon receipt of a refresh detection signal RfD indicating refresh start timing detected by a REF (Half) of the slave IC (R), the master IC (L) transmits the refresh control signal RfC to the slave IC (R), and starts refreshing the left active area of the display portion. Upon receipt of the refresh control signal RfC, the slave IC (R) starts refreshing a right active area of the display portion.

A scanning line drive unit selects a plurality of scanning lines in order, and controls the operation of a thin-film transistors. A timing control unit controls the scanning line drive unit on the basis of a display signal that includes a horizontal synchronization signal, a vertical synchronization signal, and an image signal. The timing control unit is provided with: a first terminal to which the display signal is input; a second terminal to which a sub-synchronization signal, which is a signal other than the horizontal synchronization signal and the vertical synchronization signal, is input; and a notification unit that outputs a notification signal in a case where a period while only the sub-synchronization signal, among the horizontal synchronization signal, the vertical synchronization signal, and the sub-synchronization signal, is input is longer than a prescribed period.

Liquid crystal display device

Provided are a liquid crystal display device and a drive method thereof, capable of promptly making an afterimage, which is visually recognized during pause drive, visually unrecognizable while suppressing power consumption. When updated image data is transmitted, a first refresh is performed by used of this image data, and a refresh pauses based on Ref_int just in the next two-frame period. Then, the second and third refreshes are consecutively performed, and a refresh pause is repeated until the next updated image data is transmitted. In this case, since a refresh can be performed three times in a short period after reception of the updated image data, it is possible to make liquid crystal molecules oriented in a direction corresponding to an applied voltage in a short time and make an afterimage visually unrecognizable.

Liquid-crystal display device and drive method thereof

Based on a REF/NREF signal coming from a REF/NREF determination circuit, a polarity bias calculation circuit updates a polarity bias count value Nb indicating a degree of a polarity bias of an applied voltage to a liquid crystal layer, and based on this polarity bias count value Nb, a bias movement determination circuit determines a moving direction of the polarity bias. Upon receiving an OFF signal Soff instructing OFF of the power supply, a balance control circuit controls a drive unit based on a result of the determination of the polarity bias moving direction and on the polarity bias count value Nb at a point of time when the OFF signal Soff is inputted so that the polarity bias can be resolved before a power supply is turned off.

Liquid-crystal display device and method for driving same

Provided are a liquid crystal display device and a drive method thereof, capable of promptly making an afterimage, which is visually recognized at refresh time, visually unrecognizable and reducing power consumption during and after a shift to a target refresh rate. At pause drive time until a target refresh rate is reached, a refresh is performed in divided periods of a first refresh period for performing a refresh at least twice, and a second refresh period for performing a refresh while increasing the number of frames in a non-refresh period from a refresh rate at the end of the first refresh period until the refresh rate becomes the target refresh rate, and the second refresh period is finished when the refresh rate in the second refresh period reaches the target refresh rate, and the pause drive is continued at the target refresh rate.

A scanning line drive unit sequentially selects a plurality of scanning lines, and utilizes a drive voltage generated by the booster circuit to control the operation of a thin-film transistor. A timing control unit controls the scanning line drive unit on the basis of a display signal, which includes a horizontal synchronization signal, a vertical synchronization signal and an image signal. A reference synchronization signal is input to the booster circuit during a period in which the scanning line drive unit selects none of the plurality of scanning lines. A booster circuit generates a non-selection voltage in synchronization with the reference synchronization signal in the abovementioned period. The scanning line drive unit outputs the non-selection voltage generated by the booster circuit to the plurality of scanning lines in the abovementioned period.

In a liquid crystal display device for performing pause driving, occurrence of flicker is effectively suppressed while an increase in power consumption is suppressed. When a frame in which an image signal (DAT) is inputted from an external portion without output of a request signal (RO) for requesting the external portion to input the image signal (DAT) is defined as a first input frame, a reversal driving control portion () sets the reversal driving technique in the first input frame to the column-reversal driving while setting the first input frame to a refresh frame defined as a first refresh frame, sets three frames subsequent to the first refresh frame to pause frames, sets a frame subsequent to the final pause frame to a refresh frame defined as a second refresh frame, and sets the reversal driving technique in the second refresh frame to the dot-reversal driving.

Liquid crystal display device and method for driving same

The purpose of the present invention is to provide a display device in which the occurrence of the crosstalk can be suppressed. A display unit includes a display panel (), a storage unit (), a confirmation unit (), and a correction unit (). The display panel displays a synthetic image. The storage unit stores respective crosstalk levels set with respect to a plurality of areas () that the display panel has. The confirmation unit that confirms in which one of the plurality of areas a pixel exists that displays an image that a viewer is supposed to see, among the plurality of images contained in the synthetic image. The correction unit reads the crosstalk level corresponding to the area, among the plurality of areas, in which the confirmation unit confirms the pixel displaying the image that a viewer is supposed to see exist, from the storage unit, and corrects the gray scale level data of the pixel displaying the image that a viewer is supposed to see, by using the crosstalk level.

Display device

Provided is a liquid crystal display device capable of reliably reducing power consumption during pause drive by controlling the timing of performing refresh. When there is an image change in externally inputted RGB data, or when the number of consecutive pause frames reaches a predetermined value, if the number of immediately preceding pause frames is less than a threshold BCTH, image signal refresh is performed once, or if the number of pause frames is greater than or equal to the threshold BCTH, boost charge refresh is performed first, and then, the image signal refresh is performed. As a result, it is rendered possible to reduce flicker due to luminance reduction, and it is also rendered possible to eliminate the need to perform refresh consecutively even if the frequency of RGB data is high (e.g., 30 Hz) during pause drive.

In a liquid crystal display device for performing pause driving, occurrence of flicker is effectively suppressed while an increase in power consumption is suppressed. When an image change determination portion () detects an image change in a period from the previous refresh frame until generation of a predetermined number of times of pause frames, a reversal driving control portion () sets the next frame after a frame where an image change has been detected to a refresh frame where a reversal driving technique is a column-reversal driving. When the image change determination portion () does not detect an image change in the period from the previous refresh frame until generation of the predetermined number of times of pause frames, the reversal driving control portion () sets the next frame after the final pause frame to a refresh frame where a reversal driving technique is a dot-reversal driving.

In a liquid crystal display device for performing pause driving, occurrence of flicker is effectively suppressed while an increase in power consumption is suppressed. A frame in which an image signal is inputted without requesting an external portion to input the image signal is set as a refresh frame by a reversal driving technique deciding portion. A pause frame counting portion counts the number of times of pause frames since the previous refresh frame as a count value. The comparison portion compares the count value with a previously set threshold. As a result, when the count value is not smaller than the threshold, the reversal driving technique deciding portion sets a reversal driving technique in the first input frame to dot-reversal driving. When the count value is smaller than the threshold, the reversal driving technique deciding portion sets a reversal driving technique in the first input frame to column-reversal driving.

The purpose of the present invention is to provide a display device in which the occurrence of crosstalk can be suppressed. A display device () includes a display unit and a separation unit (). The display unit displays a synthetic image formed by dividing each of a plurality of images that are different from one another and arraying the divisional images thus obtained in a predetermined order. The separation unit () separates the plurality of images contained in the synthetic image. The display unit includes a storage unit () and a correction unit (). The storage unit () stores crosstalk levels set with respect to respective combinations of gray scale level data including gray scale level data of a pixel displaying an image that a viewer is supposed to see, among the plurality of images contained in the synthetic image, and gray scale level data of a pixel serving as a factor that causes crosstalk. The correction unit () corrects the gray scale level data of the pixel displaying the image that a viewer is supposed to see, by using the crosstalk levels read out of the storage unit ().

Display device with crosstalk level correction

The purpose of the present invention is to provide a display device in which the occurrence of crosstalk can be suppressed. A display device () includes a display unit and a separation unit (). The display unit displays a synthetic image formed by dividing each of a plurality of images that are different from one another and arraying the divisional images thus obtained in a predetermined order. The separation unit () separates the plurality of images contained in the synthetic image. The display unit includes a storage unit () and a correction unit (). The storage unit () stores crosstalk levels used when gray scale level data of a pixel displaying an image that a viewer is supposed to see, among the plurality of images contained in the synthetic image, are corrected. The correction unit () corrects the gray scale level data of the pixel displaying the image that a viewer is supposed to see, by using the crosstalk levels stored in the storage unit (). The crosstalk levels are set for the case where a viewer is supposed to see images in a plurality of predetermined directions, respectively.

Growing community of inventors

Osaka, Japan

Takuya Sone