Renesas Electronics Corporation

Renesas Technology Corp.

Other

Hitachi, Ltd.

Synaptics Display Devices Gk

Synaptics Display Devices Kk

Kunihiko Tani

Yoshikazu Yokota

Gorou Sakamaki

Kazuhisa Higuchi

Kimihiko Sugiyama

Takashi Yoneoka

Katsuhiko Yamamoto

Yasuhito Kurokawa

Goro Sakamaki

Shigeru Ohta

Kei Tanabe

Takashi Ohyama

Masashige Harada

Sosuke Suji

A display control device and technique for controlling displays on a display unit, in which a plurality of display segments are two-dimensionally arranged (e.g. a dot matrix type display unit), is provided. The technique is effectively applicable to a write data latch circuit of a memory for storing display data in the display control device, such as, for example, a liquid crystal display control device, a mobile electronic apparatus, etc. A display drive control technique for controlling a moving picture display mode of a display device is also provided. The display drive control circuit controls a picture display mode of a display device for displaying still pictures and moving pictures to a liquid crystal display device, such as, for example, a dot matrix type display devices, an organic EL display device, etc.

Display control device and mobile electronic apparatus

The display driver includes an image memory which is configured by including a plurality of memory mats, a plurality of power supply switches which can perform an ON and OFF control of power supply to each of the plurality of memory mats, and a control circuit which turns on or off the power supply switches. The control circuit turns on the plurality of power supply switches in such a manner that the power supply to the memory mat to which the image data is written at an initial time, among the plurality of memory mats, becomes stable earlier than the power supply to the other memory mats.

Display driver

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 conventional liquid crystal display controllers, the display is reduced in the stand-by state but the liquid crystal display duty is not changed, i.e., even the common electrodes of the rows that are not producing display are scanned, and the consumption of electric power is not decreased to a sufficient degree in the stand-by state. A liquid crystal display controller includes a drive duty selection register capable of being rewritten by a microprocessor, and a drive bias selection register. When the display is changed from the whole display on a liquid crystal display panel to a partial display on part of the rows only, the preset values of the drive duty selection register and of the drive bias selection register are changed, so that the display is selectively produced on a portion of the liquid crystal display panel at a low voltage with a low-duty drive.

Liquid crystal display controller and liquid crystal display device

In conventional liquid crystal display controllers such as for portable telephone sets, the display is reduced in the stand-by state but the liquid crystal display duty is not changed, i.e., even the common electrodes of the rows that are not producing display are scanned, and the consumption of electric power is not decreased to a sufficient degree in the stand-by state. A liquid crystal display controller () includes a drive duty selection register () capable of being rewritten by a microprocessor (), and a drive bias selection register (). When the display is changed from the whole display on a liquid crystal display panel () to a partial display on part of the rows only, the preset values of the drive duty selection register and of the drive bias selection register are changed, so that the display is selectively produced on a portion of the liquid crystal display panel at a low voltage with a low-duty drive.

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 conventional liquid crystal display controllers such as for portable telephone sets, the display is reduced in the stand-by state but the liquid crystal display duty is not changed, i.e., even the common electrodes of the rows that are not producing display are scanned, and the consumption of electric power is not decreased to a sufficient degree in the stand-by state. A liquid crystal display controller ( ) includes a drive duty selection register ( ) capable of being rewritten by a microprocessor ( ), and a drive bias selection register ( ). When the display is changed from the whole display on a liquid crystal display panel ( ) to a partial display on part of the rows only, the preset values of the drive duty selection register and of the drive bias selection register are changed, so that the display is selectively produced on a portion of the liquid crystal display panel at a low voltage with a low-duty drive.

Growing community of inventors

Kodaira, Japan

Kunihiko Tani