Sharp Kabushiki Kaisha Corporation

Jin Miyazawa

Noriyuki Tanaka

Kazuo Nakamura

Daiji Kitagawa

Tomohiko Nishimura

Takuya Sone

Kouji Kumada

Kazuki Takahashi

Tatsuhiko Suyama

Yousuke Nakamura

Daisuke Suehiro

Norio Ohmura

Kentaroh Uemura

Yuta Tanaka

A method for driving a display device capable of appropriately performing idle driving even when timing information is not transmitted to a liquid crystal module in advance is provided. In a case where, in one vertical period, a non-scanning period other than a scanning period in which a screen of a display unit is scanned once is set to a pause period, a liquid crystal module delays supply of a data signal to the display unit by a recovery period during which a source driver is recovered from a sleep state to an active state in the pause period.

Method for driving display device, and display device

A memory liquid crystal display including a liquid crystal panel with a built-in touch panel is provided with a state control circuit configured to switch a state of a pixel electrode between a floating state and a non-floating state. A pulse signal for touch detection is supplied to a common electrode in a touch detection period. The state control circuit changes the state of the pixel electrode from the non-floating state to the floating state before the start of the touch detection period, and changes the state of the pixel electrode from the floating state to the non-floating state after the end of the touch detection period.

Liquid crystal display with in-cell touch panel preventing display defect during touch detection

In a memory liquid crystal display including a liquid crystal panel with a built-in touch panel, a black voltage or a white voltage is provided to a pixel electrode in accordance with a value of binary data stored in a memory circuit, and a display voltage generation circuit changes voltage values of the black voltage and the white voltage in synchronization with a continuous pulse voltage for touch detection in a touch detection period so that an absolute value of a voltage between the pixel electrode and a common electrode is maintained at a constant magnitude in each pixel circuit throughout a period from a point in time immediately before the start of the touch detection period to a point in time immediately after the end of the touch detection period.

Liquid crystal display device and method for driving same

A display device can extend a pause period by using a preset second setting period as a unit when a length of the pause period exceeds the second setting period. Further, detection of a touch position and specification of coordinates are interrupted when a vertical synchronization signal is received while specifying the coordinates of the touch position, and coordinates remaining in a coordinate calculation unit are discarded.

Display device with built-in touch panel and driving method therefor

A touch panel display device includes an active matrix substrate and a control unit. The active matrix substrate is provided with gate lines, pixel electrodes connected to the gate lines, counter electrodes disposed to form a matrix, and touch sensor wires connected to the counter electrodes. The control unit alternately switches, during one frame period, between a gate scan period of scanning the gate lines and a sensor scan period of scanning the counter electrodes by a segment SEG and detecting electrostatic capacitance by. The one frame period includes a plurality of gate scan periods and a plurality of sensor scan periods. The control unit scans each of the segments in a first scan mode of completing touch detection of scanning all the segments in the one frame period a number of times other than an integer.

Display device with touch panel

An object of the present invention is to further reduce the power consumption of a display device adopting pause driving. In a display device that includes a display driving unit () that drives a display unit (); and a power supply circuit () that generates a plurality of operation voltages to be supplied to the display driving unit (), and performs pause driving that repeats a scanning period during which gate bus lines (GL) are scanned and a pause period during which the scanning of the gate bus lines (GL) is stopped, the display driving unit () provides a control signal (SM) indicating whether the current point in time is the scanning period or the pause period, to the power supply circuit (), and the power supply circuit () makes the voltage value of at least one of the plurality of operation voltages supplied to the display driving unit () smaller during the pause period than during the scanning period, based on the control signal (SM).

Display device that performs pause driving

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.

Provided are a liquid crystal display device and a driving method therefor that do not cause problems such as occurrence of flicker even when performing pause driving. When an off signal Soff instructing to turn off power is inputted, a polarity bias value W at the power-off is stored in a balance storage circuit. When the power is turned on again, the polarity bias value W is read from the balance storage circuit and provided to a balance control circuit. The balance control circuit starts insertion of a pause frame period to cancel out the polarity bias value W. By this, decrementing the polarity bias value W by '1' every insertion of a pause frame period is repeated. Then, at a point of time when the polarity bias value W becomes '0', insertion of a pause frame period is ceased and normal pause driving is performed.

Liquid crystal display device including display control circuitry configured to store a polarity bias value

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 is a display device with a touch sensor that can avoid the influence of noise originating from the polarity inversion of a common voltage of the display device without using special circuitry. The display device with a touch sensor includes a sensor output readout circuit () that is sequentially connected to multiple sensor electrodes in a touch sensor unit () and outputs signal voltages that correspond to the electrical characteristics of the electrodes, a sensor control circuit () that supplies a control signal to the sensor output readout circuit (), and a coordinate computation circuit () that detects a contact position based on the signal voltages. The sensor control circuit () causes a scan operation, in which the sensor output readout circuit () is sequentially connected to all of the sensor electrodes of the touch sensor unit () and outputs the signal voltages, to start after the common voltage has switched from a first polarity to a second polarity, and to end before the common voltage returns to the first polarity.

Display device with touch sensor

Provided is a touch sensor-equipped display device that is not susceptible to the effect of noise caused by the reversal of polarity of the common voltage of the display device, without using special circuits. The touch sensor-equipped display device includes: a touch sensor unithaving a plurality of sensor electrodes; a sensor output read circuitthat is sequentially connected to the respective sensor electrodes and that outputs a signal voltage corresponding to the electrical characteristics of the sensor electrode connected thereto; a sensor control circuitthat supplies a control signal to the sensor output read circuit; and a coordinate calculation circuitthat detects a contact position on the basis of the signal voltage. The coordinate calculation circuitincludes: an averaging circuitthat calculates an average value for the signal voltage values outputted from the sensor output read circuitover two cycles of the vertical synchronizing signal; and a contact position detection circuitthat detects the contact position on the basis of the average value.

Touch sensor-equipped display device

In order to provide a touch sensor-equipped display device that is not susceptible to the effect of noise caused by a polarity reversal in a common voltage of a display device without using special circuitry, the disclosed touch sensor-equipped display device is provided with: a sensor output read circuitthat is sequentially connected to a plurality of sensor electrodes of a touch sensor partand that outputs a signal voltage according to the electrical properties of each electrode; a sensor control circuitthat supplies a control signal to the sensor output read circuit; and a coordinate calculation circuitthat detects a contact position on the basis of the signal voltage. The coordinate calculation circuitis provided with: an averaging circuitthat calculates the average values of signal voltage values obtained during a scan that was started in synchronization with a horizontal synchronization signal when the common voltage is reversed from positive polarity to negative polarity, and the signal voltage values obtained during a scan that was started in synchronization with a horizontal synchronization signal when the common voltage is reversed from negative polarity to positive polarity; and a contact position detection circuitthat detects the contact position on the basis of the average values.

Growing community of inventors

Sakai, Japan

Jin Miyazawa