Other

Renesas Electronics Corporation

Renesas Technology Corp.

Hitachi, Ltd.

Hitachi Device Engineering Co., Ltd.

Kimihiko Sugiyama

Yoshikazu Yokota

Kazuhisa Higuchi

Kunihiko Tani

Gorou Sakamaki

Takashi Yoneoka

Katsuhiko Yamamoto

Satoru Tsunekawa

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.

A liquid crystal display device includes a liquid crystal display panel and a semiconductor integrated circuit for driving and controlling the liquid crystal display panel. The number of input/output wires connected to I/O terminals (bonding pads) of the semiconductor integrated circuit is reduced so as to simplify wiring patterns of the I/O wires, whereby degrees of freedom in arranging the I/O wiring patterns are enhanced. The panel has a pair of insulating substrate, and the semiconductor integrated circuit is mounted on one of the paired substrates. The semiconductor integrated circuit has a mode terminal which is fixed to a power supply potential or to a reference potential during operation of the integrated circuit, and power supply dummy terminals connected to the power supply potential or reference potential inside the semiconductor integrated circuit. The wiring patterns formed on the paired insulating substrates connect the mode terminal to the power supply dummy terminals.

Liquid crystal display device, method for fabricating the same, and portable telephone using the same

A liquid crystal display device comprises a liquid crystal display panel and a semiconductor integrated circuit for driving and controlling the liquid crystal display panel. The number of input/output wires connected to I/O terminals (bonding pads) of the semiconductor integrated circuit is reduced so as to simplify wiring patterns of the I/O wires, whereby degrees of freedom in arranging the I/O wiring patterns are enhanced. The panel has a pair of insulating substrate, and the semiconductor integrated circuit is mounted on one of the paired substrates. The semiconductor integrated circuit has a mode terminal which is fixed to a power supply potential or to a reference potential during operation of the integrated circuit, and power supply dummy terminals connected to the power supply potential or reference potential inside the semiconductor integrated circuit. The wiring patterns formed on the paired insulating substrates connect the mode terminal to the power supply dummy terminals.

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.

The liquid-crystal display control apparatus provided by the present invention comprises a display RAM unit for storing character codes, character-generator RAM and ROM units and for storing character font patterns and a segment RAM unit for storing picture patterns such as marks and icons. When displaying a character, the following display control is carried out. First of all, a character code is read out from the display RAM unit at a display address generated by a display-address counter . The character code is then used in conjunction with a raster address output by a line-address counter for reading out a character font pattern from the character-generator RAM unit or the character-generator ROM unit . When displaying a picture pattern such as a mark or an icon, on the other hand, the following display control is carried out. Display control information is read out from the segment RAM unit at an address generated by the display-address counter . Dot-matrix characters and picture patterns such as marks and icons are displayed on the same screen on a time-division basis.

Liquid-crystal display control apparatus

Liquid crystal display device, production method thereof and mobile telephone

The liquid-crystal display control apparatus provided by the present invention includes a display RAM unit for storing character codes, character-generator RAM and ROM units for storing character font patterns, and a segment RAM unit for storing picture patterns such as marks and icons. When displaying a character, the following display control is carried out. First of all, a character code is read out from the display RAM unit at a display address generated by a display-address counter. The character code is then used in conjunction with a raster address output by a line-address counter for reading out a character font pattern from the character-generator RAM unit or the character-generator ROM unit. When displaying a picture pattern such as a mark or an icon, on the other hand, the following display control is carried out. Display control information is read out from the segment RAM unit at an address generated by the display-address counter. Dot-matrix characters and picture patterns such as marks and icons are displayed on the same screen on a time-division basis.

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

Matsudo, Japan

Kimihiko Sugiyama