Japan's public broadcaster showed off some bleeding-edge display technologies on Thursday that could one day lead to flexible TVs that roll up and slip in the pocket, and to smaller high resolution plasma displays than are available today.
Broadcasting company Nippon Hoso Kyokai (NHK) has developed a flexible display that measures 5 inches in diagonal using a new type of "high-brightness" ink. It is the biggest display developed to date using the ink, and the technology could be used to create a flexible TV in as little as seven years, according to Shizuo Tokito, a senior research scientist at NHK's Science and Technical Research Laboratories (STRL), during an open day in Tokyo on Thursday.
The phosphorescent ink is printed in spots on the display and sandwiched between electrodes. When a current is passed through the screen, the ink creates white light which is turned into colors using filters, creating an image on the screen.
The 5-inch screen has a resolution of only 160 pixels by 120 pixels, far below that of conventional LCD screens. NHK needs to refine the technology in order to reach its next target -- a 12-inch screen that it hopes to develop by 2010, Tokito said. The TV tuner and controls will be embedded in the rollable display, the researchers said. NHK must also find a partner to manufacture the products.
The ink can shine four times brighter than other inks being used to develop flexible displays, according to Tokito. This allows displays to be built that use far less electricity. "If you are talking about portability for flexible TVs, low power consumption is essential," he said.
The company's roadmap calls for 15-inch flexible panels with resolution of 640 pixels by 480 pixels being ready for commercial production in about 2012, and 23-inch panels with 1920 pixels by 1080 pixels resolution by 2017.
Researchers at STRL are also trying to shrink the size of pixels to bring HDTV to flat panels that are smaller than those on sale today, they said. To that end, the laboratory is working on two technologies: one that refines today's plasma TV technology, and another based on a new technology called FED (field emission display).
Working with Japan's Pioneer, a big maker of plasma TVs, NHK has shrunk the pitch of plasma display pixels to 0.3 millimeters, about a third that of many of today's plasma televisions, according to Yasushi Motoyama, a senior research engineer at STRL. Pixel pitch refers to the distance from the center of one pixel to the center of an adjacent pixel.
Decreasing the pixel pitch makes it possible to build panels that can show increasingly higher definition pictures on smaller and smaller screens, according to Lee Soo Kun, a consumer digital electronics analyst at Data Garage KK, a Tokyo-based consultancy. The pixel pitch of the most advanced plasma HDTVs is currently moving to 0.8 mm, he said.
Within five to 10 years, the technology should lead to plasma displays capable of showing HD pictures that have 1080 rows of pixels on TVs as small as 26 inches in diagonal, Motoyama said. Most plasma TVs today are greater than 40 inches, although some are smaller.
NHK also showed a 1.6-inch FED screen with a 0.24 mm pixel pitch, but can reduce this to 0.15 mm, according to Mizumoto Ushirozawa, a senior researcher at STRL. The technology should enable flat-panel HD screens only 13 inches along the diagonal in less than 10 years, he said.