Renesas Technology Corp.

Renesas Electronics Corporation

Hitachi, Ltd.

Synaptics Display Devices Gk

Hitachi Displays, Ltd.

Kazuo Okado

Yasuyuki Kudo

Akihito Akai

Hiroki Aizawa

Toshimitsu Matsudo

Takuya Eriguchi

Tatsuya Ishii

Atsuhiro Higa

Naoki Takada

Masaru Kokubo

Takesada Akiba

Tsuyoshi Kuroiwa

Yusuke Uchida

Yusuke Takeuchi

Keizo Yabuta

Kunihiko Watanabe

Gaku Masumoto

Toshio Mizuno

Hisayoshi Kajiwara

Atuko Kenmoku

An impedance measuring semiconductor circuit that measures impedance of a specimen. The impedance measuring semiconductor circuit includes an operational amplifier, a resistance coupled between a negative input terminal and an output terminal of the operational amplifier, a D/A converter coupled to a positive input terminal, a switch; an A/D converter that is coupled with the output terminal of the operational amplifier and a one-side terminal of a specimen and measures an output voltage from the operational amplifier and a one-side terminal voltage, and a controller that controls an output voltage from the D/A converter based on a one-side terminal voltage measured by the A/D converter.

Impedance measuring semiconductor circuit and blood-sugar level meter

The touch panel controller activates a touch panel having a detection plane superposed on a display plane of a display device, and performs a touch detection. The touch panel controller uses a cycle of 1/n (n is a positive integer) of a display frame cycle on the display plane as the detection frame cycle of the detection plane. The touch panel controller decides an order of driving the detection-scan electrodes in each detection frame cycle according to predetermined phase-delay and phase-advance positions with respect to a display-scan electrode drive position of the display device so as to correspond to an order of the detection-scan electrode array of the touch panel. The touch panel controller makes possible to avoid the coincidence of display-scan and touch-detection positions without thinning touch detections even with the detection frame cycle of a touch sensor shorter than the display frame cycle of a liquid crystal panel.

Touch panel controller and semiconductor device

It becomes possible to use drive pulses having different pulse widths for one kind of drive pulse signal period. Therefore, even if a voltage acting on a crossing part of drive and detection electrodes is periodically changed through a stray capacitance attributed to an external object such as a finger in an undesired manner, the pulse width of the drive pulse is never fixed with respect to the period, and the periodic buildup of a certain voltage on a detection signal, which would make appreciable noise, is suppressed. Thus, the reduction of detection signals can be suppressed in quantity without switching the pulse signal frequency of the drive pulse of a touch panel.

Capacitive touch panel device with differing drive pulse widths

In consideration of the current leakage path of a liquid crystal panel and a signal line voltage fluctuation due to the current leakage path, a &#x3b3; adjusting function (second driving method) is applied for each divided period in the first driving method. In a signal line driving unit, a gray scale voltage obtained by adding or subtracting a voltage fluctuation value different in each of the output periods of each gray scale is generated, and a gray scale voltage taking the voltage fluctuation value into consideration is applied to a signal line.

Display driver

A light control circuit that makes it possible to, when the light intensity of the area surrounding a display screen varies in a relatively short time, prevent the brightness of a backlight from being erroneously adjusted as the result of the variation being detected is provided. The light control circuit controls the backlight of a display panel. This light control circuit is provided with functions of performing the following operation: detection signals from multiple optical sensors are taken into a common sampling means in a time division manner to acquire multiple sampling values temporally dispersed; a surrounding light intensity is determined by majority decision based on the multiple sampling values, and the result of determination is externally outputted.

Light control circuit and a liquid-crystal-display control drive device

A liquid crystal display is provided with: a tap adjustment register for adjusting a gray scale level to a gray scale voltage in intermediate portions close to the end portions of the gamma characteristic; and a partial-voltage-ratio adjustment register for adjusting a ratio of a gray scale voltage among a plurality of gray scale levels in the intermediate portions close to the end portions of the gamma characteristic, in addition to an amplitude adjustment register for adjusting an amplitude of a gamma characteristic which determines a relation between gray scale levels and gray scale voltages or brightness levels on a display panel; a gradient adjustment register for adjusting a gradient of intermediate portions of the gamma characteristic while fixing end portions of the gamma characteristic; and a fine adjustment register for finely adjusting the intermediate portions of the gamma characteristic for each gray scale level.

A display driver used in common for a first screen and a second screen. The display driver includes a data line drive circuit which supplies gray scale voltages to the first and second screens in accordance with display data via data lines in common for the first and second screens, and a scan line drive circuit which supplies scan signals to the first and second screens via scan lines, with the scan lines in the first screen being different from the scan lines in the second screen. The scan line drive circuit scans the second screen in one of a one-line-at-a-time operation and a plural-line-at-a-time operation by using the scan signals every time the scan line drive circuit scans at least one frame of the first screen in a one-line-at-a-time operation by using the scan signals.

Device for driving a display apparatus

A display driver for outputting gradation voltages corresponding to gradation data from an external device to pixels. The display driver includes a generator for generating a plurality of gradation voltages having a plurality of levels based on a reference voltage, and a selector for selecting at least one gradation voltage corresponding to the gradation data from the plurality of gradation voltages generated by the generator. The gradation data includes multi-bits for each color of red, green and blue, and the generator outputs or stops outputting each gradation voltage according to data for color reduction from the external device. The generator stops outputting at least one gradation voltage that is unnecessary for displaying as a result of the color reduction, when the color of the gradation data is reduced according to the data for color reduction.

Display device and driving circuit for displaying

A driving circuit provided by the present invention is characterized in that the driving circuit selects a gray-scale voltage in accordance with high-order bits of display data from a group of gray-scale voltages with their voltage level varying step by step from fractional time period to fractional time period, which are set in advance, and outputs the selected gray-scale voltage during a time period between the start of a scanning period and a time at which a number assigned to a fractional time period matches quantitative information contained in low-order bits of the display data. In addition, the driving circuit provided by the present invention is also characterized in that the time ratio of the first fractional time period is set at a relatively high value while the time ratios of the second and subsequent fractional time periods are each set at a relatively low value.

Driving circuits for display device

An object of the present invention is to provide a signal line driving circuit capable of easily and optimally adjusting the gamma characteristics of R, G, and B self-emitting element groups (e.g., organic EL element groups) such that each gamma characteristic matches the characteristics of the self-emitting panel by accommodating variations among the characteristics of the R, G, and B self-emitting element groups, thereby providing enhanced image quality and versatility. A self-emitting display driving circuit (a signal line driving circuit)includes 3 gray-scale voltage generating circuitsand 3 control registersfor R, G, and B self-emitting element groups, respectively, and these gray-scale voltage generating circuits and control registers can be adjusted separately. This arrangement makes it possible to accommodate variations among the characteristics of the R, G, and B self-emitting element groups and thereby provide enhanced image quality on the self-emitting display.

Circuit for adjusting gray-scale voltages of a self-emitting display device

A display apparatus includes a data driver that is common to a main screen and a sub screen, and the data driver applies, to the main screen, a tone voltage corresponding to display data from a CPU, and during a vertical blanking time-period of the main screen, the data driver applies, to the sub screen, a tone voltage corresponding to black data or white data, and also includes a scan driver scans the main screen and scans the sub screen during the vertical blanking time-period of the main screen.

Display apparatus

There is provided a device for driving a display apparatus. A data line drive section is common to a main screen and a sub-screen, supplies to the main screen gray scale voltages corresponding to display data from CPU, and supplies to the sub-screen a gray scale voltage corresponding to black or white data during a vertical blanking period of the main screen. A scan line drive section scans the main screen, and also scans the sub-screen during the vertical blanking period of the main screen.

A frame memorystores the original image data received from a higher-level devicevia an interface. Color reduction processing means receives color reduction rate data through a transfer from an upper-level deviceor manual setting means such as a switch or jumper settings. Based on this color reduction rate data, the number of colors in the gradation data of the original image is reduced, and the color count of the original image is simulated using the reduced color count. Also included are a timing generating circuitand a gradation voltage generating circuit. A gradation voltage selectorperforms a partial halting of driver operations based on the color reduction rate.

A sending data buffer for holding sending data temporarily and transmitting the data to an echo canceler section is installed between a sending section and an echo canceler section of an echo canceler integrated circuit included in a subscriber line circuit of an integrated service digital network. The sending data buffer is operated in a shift register mode during a sending training mode, and operated in FIFO (first in-first out) mode during a sending/receiving training mode. Also, an adjustment function of the delay amount corresponding to the use setting is added.

Growing community of inventors

Kokubunji, Japan

Kazuo Okado