Renesas Electronics Corporation

Renesas Technology Corp.

Synaptics Japan Gk

Synaptics Display Devices Gk

Synaptics Display Devices Kk

Yasuhito Kurokawa

Kunihiko Tani

Goro Sakamaki

Kei Tanabe

Takatoshi Uchida

Yoshikazu Yokota

Shigeru Ohta

Toshiyuki Hikichi

Masashi Takata

Shutaro Ichikawa

The display device includes display drivers including first and second ones operable to output, based on display data, gradation signals to source lines of display panel regions. The display device is arranged to be able to suppress the variation in output voltage between display drivers while minimizing the increases in chip area of the display drivers and in wiring area of a display panel and keeping high noise resistance. Each display driver can generate gray scale reference voltages for producing gradation signals corresponding to display data. The first display driver can sequentially transmit gray scale reference voltages generated by itself to the second display driver. Based on the transmitted gray scale reference voltages, the second display driver makes the first display driver execute calibration for decreasing the absolute value of difference between gray scale reference voltages generated by the first and second display drivers, or executes the calibration by itself.

Display device and display driver with sequential transfer of gray scale reference voltages

A display device is arranged so as to be able to conduct a touch detection action for sensing a region where a touch operation on a touch panel has been performed, to stop the touch detection action in the touch panel, and to specify a touch-detection-stop region. The display device includes an image-display-direction register. A processor writes parameters designating an image-display direction into the image-display-direction register based on a result of detection by a tilt detector. On condition that parameters stored in the image-display-direction register have been changed, the display device changes the touch-detection-stop region based on the parameters. The above function is mounted on a semiconductor integrated circuit device included in the display device.

Semiconductor integrated circuit device, display device and information technology device

A display control drive device sequentially reads display data from a display memory in which the display data is stored, produces three primary color image signals that are applied to pixel locations in a dot-matrix color display device, and transmits the signals through a common external output terminal in a time-sharing manner. The display control drive device produces control signals applied to selection switching elements in the display device and that selectively apply an input image signal to any of three source lines. The display control drive device includes: a unit that determines one horizontal period based on a clock received from outside synchronously with display data; and a signal production circuit that produces and transmits the control signals, applied to the selection switching elements, so that the control signals will have a pulse duration equivalent to a time calculated by trisecting one horizontal period.

Display control drive device and display system

In a system including a color liquid crystal panel, a liquid crystal display drive control device for driving the panel, and a microprocessor, the display drive control device of the invention lightens the burden imposed on a microprocessor as well as reduces the power consumption of the system. In the liquid crystal display drive control device that incorporates a memory for storing image data displayed on a color liquid crystal panel, reads out the image data sequentially from the memory, generates image signals of the three primary colors for each pixels of the color liquid crystal panel, and outputs the image signals from external output terminals, the display drive control device includes a transparency arithmetic circuit that applies a calculation processing to two image data read out from the built-in memory and generates data for a transparent display, supplies display data generated by the transparency arithmetic circuit to a driver, and makes the driver generate and output drive signals to the liquid crystal panel.

Display drive control device and electric device including display device

In a display control drive device that displays an image on a display device, a data transfer rate may vary depending on received image data because of a difference in an image size. Assuming that driving force with which a driver or an amplifier is driven is designed based on a maximum data transfer rate and the driver or amplifier is operated with the driving force, when the transfer rate is low, an unnecessary current is consumed. According to the present invention, a display control drive device sequentially reads display data from a display memory in which the display data is stored, produces three primary color image signals that are applied to pixel locations in a dot-matrix color display device, and transmits the signals through a common external output terminal in a time-sharing manner. Moreover, the display control drive device produces control signals to be applied to selection switching elements that are incorporated in the display device and that selectively apply an input image signal to any of three source lines. The display control drive device includes: a unit that determines one horizontal period on the basis of a clock received from outside synchronously with display data; and a signal production circuit that produces and transmits the control signals, which are applied to the selection switching elements, so that the control signals will have a pulse duration equivalent to a time calculated by trisecting one horizontal period.

There is provided a display driver control circuit which is just suitable for display drive including display with a small amount of change and display with a large amount of change and can realize saving of chip area and reduction of power consumption and cost. In this display driver control circuit, memory capacity of an internal display memory is set smaller than amount of data of one display picture of a display panel as the drive object, and the display data can be transferred with the system in which externally inputted display data is once stored in the display memory and is then sent of a drive circuit to output a drive signal and with the system in which the display data is sent in direct to the drive circuit by way of no display memory to output a drive signal. Moreover, both transfer methods can be executed on the time division basis.

Display driver control circuit and electronic equipment with display device

In a system including a color liquid crystal panel, a drive control device for driving the panel, and a microprocessor, the drive control device reduces the burden on the microprocessor as well as power consumption. In a liquid crystal display drive control device that incorporates a memory for storing image data displayed on a color liquid crystal panel, reads out the image data sequentially from the memory, generates image signals of the three primary colors for each pixel of the panel, and outputs the image signals from external output terminals, the drive control device includes a transparency arithmetic circuit that applies calculation processing to two image data read out from built-in memory and generates data for a transparent display, supplies display data generated by the transparency arithmetic circuit to a driver, and makes the driver generate and output drive signals to the liquid crystal panel.

Growing community of inventors

Higashimurayama, Japan

Yasuhito Kurokawa