Sharp Develops New Chip for Dual-screen Mobile Devices

Jul 27, 2010
Hideyoshi Kume, Nikkei Electronics
The "LR388G9" can display two different 1,024 x 480-pixel (equivalent to Half XGA) movies on two LCD panels even when the panels have different sizes.
The "LR388G9" can display two different 1,024 x 480-pixel (equivalent to Half XGA) movies on two LCD panels even when the panels have different sizes.
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A demonstration of outputting 1,920 x 1,080-pixel (full-HD) video to an LCD TV
A demonstration of outputting 1,920 x 1,080-pixel (full-HD) video to an LCD TV
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A prototype of a dual-screen electronic book reader
A prototype of a dual-screen electronic book reader
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Sharp Corp developed a chip that controls liquid-crystals for mobile devices and can simultaneously display two different 1,024 x 480-pixel (equivalent to Half XGA) movies on two LCD panels.

The chip, "LR388G9," can also output 1,920 x 1,080-pixel (full-HD) video to an LCD TV, a projector, etc that are externally connected via an HDMI cable.

In July 2008, Sharp announced the LR388D8, which can display two different 864 x 480-pixel (equivalent to Wide VGA) movies on two screens. This time, the company enhanced the image quality by increasing the memory capacity from 16 Mbits to 32 Mbits and improving the image processing speed.

Aiming at new markets

Sharp does not consider that the LR388G9 is just a successor to the LR388D8.

"By improving the image qualities of two displays that have been used as a main display and a sub-display, both of the displays can be used as main displays," the company said.

Sharp aims to sell the new chip not only in the smartphone market but also in the electronic book reader, digital photo frame and netbook markets.

For those markets, Sharp employed several interfaces in addition to the HDMI connectivity that is for outputting full-HD video. For example, the LR388G9 is compatible with the MIPI (Mobile Industry Processor Interface), which is a high-speed serial interface. The LR388D8 only supports the MDDI (Mobile Display Digital Interface) 1.0/1.1, a serial interface standard that is for mobile phones and promoted by Qualcomm Inc. The new chip also supports the MDDI 1.1/1.2/Type2, ensuring a high versatility.

Furthermore, the LR388G9 comes with an interface that is for LCD panels and compatible with the MIPI as well as the SVDI (Sharp Video Display Interface), which was developed by Sharp.

As for the interface for still images, its maximum pixel count was increased from eight million to 14 million. And the LR388G9 supports other interfaces such as the IrSimple high-speed infrared communication standard and SD/SDHC memory cards.

The new chip comes in a 261-pin WFBGA package that measures 8 x 8mm. Sharp has already started sample shipments. The price of the sample is ¥2,400 (approx US$27.6). The company plans to start volume production at a monthly rate of 100,000 units Sept 1, 2010.