Display Week 2009: ID Magazine Blog Entries: Day 4

Information Display's "roving reporters" are blogging about what they've discovered at the 47th annual Society for Information Display's Symposium, Seminar & Exhibition. Here are their reports from Day 4:

SID and the Outside World, OLEDs, E-paper
San Antonio, TX; June 4, 2009. Jam-packed days. As SID President, I need to represent the Society to the outside world from time-to-time, so I got to escort two different reporters around the exhibit floor. Us "display people" sometimes lose perspective on how cool the things we are working on truly are; explaining to people on the outside (like reporters) what the show highlights are is very energizing. We should all be getting the word out on display technology and what's going on at SID.

Here’s a link to the video clip that played on FOX News in San Antonio. http://kabb.com/vod/videoplayer.shtml. Select the clip titled Society for Information Display Convention (date is June 3, 2009).

And here's the blog entry on the show from Austin's Digital Savant. http://www.austin360.com/blogs/content/shared-gen/blogs/austin/digitalsavant/index.html

Anyway, back to the show. Today, highlights included a stop by the UDC booth, where they showed a wearable OLED display, rugged enough for military use. I also want to mention an announcement by DuPont, where they have a new green OLED solution printable material estimated to last for 1 million hours of usage – that's 100 years! If only my lightbulbs at home lasted so long….

On the e-paper side, I really liked the Reflex "skin" technology at Kent Displays, which is a liquid crystal that can be molded onto various surfaces. Imagine your cell phone color changing to red, blue, purple, or other colors, depending on who is calling. I also liked the Harry Potter-like e-paper displays over at E Ink, showing color displays that can also show animation in a window within the display. --Paul Drzaic, President, Society for Information Display

Projectors
San Antonio, TX; June 4, 2009. How small is 0.17 inches? That's about one sixth of an inch. A display with a 0.17-in. diagonal is so small that you can fit at least four of them on your little fingernail. So what would you ever do with a display so small? You'd need a microscope to see the image. Or you could use it as an imager for a projector. And that's exactly why TI created its DLP Pico HVGA chip.The 480 x 320 pixel device is designed to be incorporated in small portable devices including mobile phones, media players, and accessory projectors. It was also the Silver Award Winner of the SID 20099 Display Device of the Year. Samsung's mobile phone with a built-in projector based on the DLP Pico has been selling in Korea and will soon start selling in Europe. And Samsung's new MPB 2000 media player has just started shipping in Korea.

At SID 2009, TI was demonstrating its $349 DLP Pico Projector Development Kit. This includes a light engine based on the DLP Pico imager, along with an RGB LED light source that produces a 7 lumen image. It accepts either DVI or VGA video input. --Alfred Poor, HDTV Almanac

LCDs
San Antonio, TX; June 4, 2009. 3D displays were a popular theme in the SID 2009 Exhibit Hall (surpassed only by touch screens), with a good mix of autostereoscopic and goggle/glasses-based technologies. Many were large-format displays, but a number of companies showed small displays suitable for portable devices such as mobile handsets. One of the most intriguing approaches was an autostereoscopic display shown by 3M.

The no-goggles approach probably is best-suited for a single-viewer device like a mobile phone, but 3M has a special wrinkle in its approach. The company makes a lenticular film that presents an image to the left eye and another to the right eye. Unlike most similar designs, however, the 3M film does not have to be aligned with the display's sub-pixels and this makes the fabrication of the panel much simpler. Instead of displaying left and right images at the same time, however, it displays just a left image, then just a right image. It achieves this by using LED edge lights on both sides. A light guide causes light from one side to project only to one eye, and light from the other side to the other side. The 3D image is created by changing the image on the panel in sync with alternating the backlight from one set of LEDs to the other. The result is a time-sequenced presentation of the two images that make the 3D image. A side benefit is that if you get too far off axis from the stereoscopic "sweet spot", you still see the uninterrupted image intended for one eye. This 2D image is a bit fainter – it is only receiving half the light of the 3D image – but is a completely legible image. This simple design is very effective, and a Wide QVGA panel using this technology is expected to appear in a commercial product before the end of this year. --Alfred Poor, HDTV Almanac

Flexible Displays
San Antonio, TX; June 4, 2009. Organic semiconductors or silicon; which is better for flexible displays? If you're looking for a sure way to start an argument, toss out this question to a group of backplane engineers, preferably after a round or two of drinks on San Antonio's Riverwalk. OTFT fans will say that their compounds are better suited to low-temperature, low-tech, high-volume patterning processes like inkjetting or screen printing, while silicon supporters point out that their materials are rock-stable, and that they've been able to adapt their ordinarily high-temperature processes to work with heat-sensitive polymer substrates.

I wouldn’t have guessed there was much middle ground, until today when I attended a presentation by Professor David Allee from Arizona State University. Allee’s team has the goal of eliminating the rigid drivers from the edges of their silicon flex panel by integrating their circuitry into the panel itself. Their task was made much harder by the fact that amorphous silicon TFTs are all n-type, while CMOS ICs use both n- and p-type silicon (the “C” in CMOS stands for "complementary," in recognition of this fact). The solution to their problem came by realizing that most organic transistor materials are inherently p-type. And so, after the ASU crew complete construction on their silicon backplanes, they ship them off to the University of Texas at Dallas to receive an OTFT overcoat. The result: displays with integrated drivers that consume 60% less power than the previous, silicon-only design.

I'll leave it to the reader to determine if there's a bigger lesson here, but at the least, it sure is a clever solution that gets us a little closer to a fully flexible display module, completely free of bulky, brittle microchips. --Robert Zehner, E Ink.