Sharp Develops Autostereoscopic 3D Touchscreen Display
April 5th, 2010Sharp Corporation has developed a 3D touchscreen LCD that can switch between 2D and 3D modes. Users can view 3D images without the need to wear glasses, making this LCD panel a likely candidate for mobile devices such as digital cameras, mobile phones, and smartphones. The new 3.4-inch panel has WVGA resolution (480 x 854 pixels), a contrast ratio of 1000:1, and a brightness of 500 cd/m2, which Sharp says is the industry’s highest brightness display for 3D LCD modules aimed at mass-produced mobile devices.
Aldo Cugnini
Insight Media Consultant
The newly developed 3D LCD uses a "parallax barrier" system to display 3D images. This parallax barrier has a series of vertical slits, somewhat similar to a lenticular 3D display, and is incorporated into an ordinary LCD to control the path of light reaching the right and left eyes, thus creating a sense of depth. Rumors point to mass production in about 6 months, putting devices in time for the holiday market. Sharp has also developed a non-touchscreen 3D LCD and will start mass production in the first half of fiscal 2010.
In the past, conventional 3D LCDs using this system had difficulty in displaying high-quality images in 3D mode. The new panel developed by Sharp is said to significantly improve image quality–achieving both high brightness and low crosstalk–by using advances in CG-Silicon technology and optimization of the parallax barrier. CG-Silicon technology is an LCD process technology that uses high-performance, crystalline silicon with electron mobility up to 600 times faster than ordinary amorphous silicon and up to six times faster than low-temperature polysilicon.
These advances in CG-Silicon technology have shrunk the wiring width within the LCD panel, allowing more light to pass, and producing double the brightness compared to the conventional model LCD that Sharp began mass-producing in 2003. In addition, optimizing the parallax barrier design has increased the efficiency of light, thereby reducing crosstalk. The thickness of the LCD module is about the same as conventional 2D displays, even though it is a touchscreen display.
And, Sharp says 3D images can be displayed in both portrait and landscape screen orientations, making it ideal for sophisticated mobile devices such as smartphones. This is interesting as it would imply that barrier stripes run both vertically and horizontally and that they can be switched on and off at will. This also means an active barrier solution (essentially another LCD panel) to control the barriers. The active barrier also helps improve 2D image quality while the 500 nits of brightness helps overcome the light loss when the barrier is on. If the implementation is as speculated, this addresses many of the key concerns about the barrier approach — albeit at the expense of more cost.
Internet chatter suggests that the 3D-effect works best when the device is held about one foot from the user’s eyes–just about where a cell phone would be held during use. (It’s not known how well the technology scales up to larger displays.) The combination of touch panel and horizontal-vertical 3D functionality make it a good fit for how the devices are used. We know that Nintendo has a 3D DS in development, and with Sharp already supplying panels for existing DS products, it’s possible that the 3D panel may show up there as well, although pricing would be a critical factor.
Another unknown is how the content would be delivered to a device; video to a cellphone uses one of various 3GPP industry standards, but none so far have specific 3D support. A proprietary format could be used, but that works against universal acceptance. There are also other ways to get video onto a handheld (WiFi, SD card, etc.), but they similarly have compatibility issues. Nonetheless, the field is not lacking for user interest in commercial content.
Avatar director James Cameron, speaking recently at the CTIA cell phone conference, said, "It’s all about mobility." Count on 3D showing up on phones before too long.













