LG at CES to Demo 3D TV Beamed to Glasses-Free Mobile DTV Receiver

LG Electronics said it plans to demonstrate at CES this week 3D broadcasts and reception to a prototype mobile DTV receiver with a seven-inch LCD screen that requires no 3D eyewear. The demonstrations, coordinated by LG engineers in South Korea, will include beaming 3D TV signals from at least one Las Vegas commercial station to the CES exhibit floor, said company spokesman John Taylor.

The demonstrations are among the innovations that LG plans to show at the CES Unveiled event Tuesday afternoon at the Venetian Hotel, Taylor said. The LG demonstrations are being trumpeted by the Open Mobile Video Coalition, which is promoting the adoption of free over-the-air DTV to mobile devices.

The CES demonstrations come nine months after LG at the NAB Show staged the first public demonstrations of ATSC 2.0-compatible “non-real-time” (NRT) broadcasting and reception, including of 3D TV (CED April 15 p6). While viewers are watching live ATSC 2.0 DTV broadcasts, the NRT function can simultaneously “cache” other broadcasts in the background onto hard drives or USB drives, so the content can be viewed later, LG said then. Though LG described the NAB demonstrations as somewhat more advanced than a “concept prototype,” it said ATSC 2.0 3D TV products and services were a long way from commercialization.

Few technical details were available at our deadline about the glasses-free mobile 3D DTV demonstrations LG plans at CES. But patent filings by the company show that it has been working for many years on autostereoscopic, glasses-free 3D TV and mobile 3D TV. For example, US 2007/0047058, dating to 2005, was filed by LG.Philips LCD, a former joint venture.

Eun Jung Lim of Korea is named in that filing as the sole inventor of a way to improve the well-known autostereoscopic system, in which a mesh of thin vertical lenticular strip lenses or optical slits is placed in front of a TV screen and the image on screen is vertically sliced into left- and right-eye views. Parallax then lets the viewer’s left eye see only the left slices and the right eye only the right slices. But inevitably the parallax barrier reduces resolution of the screen, so it’s not good for conventional 2D displays, the patent filing says.

The LG.Philips filing tells how the passive barrier may be replaced with a mesh of photochromic chemical strips, which can be switched from clear to opaque state by an ultraviolet light radiator built into the screen. One screen can be used for full-resolution 2D display or reduced-resolution no-glasses 3D display, simply by flicking a switch to turn the UV radiator on or off, the filing says. Five years later, well after the dissolution of LG.Philips, evidence shows that Lim was still refining the idea. His US 2010/0118379 filing on behalf of LG Display claims that “the 2D or 3D image mode switching barrier with the photochromic layer can be easily manufactured using simple processes."

Another LG filing, US 2007/0081208, refines autostereoscopic 3D TV viewing through mobile devices. Though a stationary living room 3D TV screen is viewed only in landscape mode, mobile devices can be used either for portrait or landscape viewing, depending on the program content or the user’s preference, the filing says. The number of view slices may need to be increased from two to three in landscape mode, it says. So a conventional vertical parallax barrier will not work, it says. LG’s idea is to cover the screen with a symmetrical criss-cross parallax barrier and optically align the screen pixels with the barrier, so it can produce a 3D effect from either two or three views, in either a horizontal or a vertical direction, depending solely on how the pixels are electrically switched to display the image, the filing says.

Other LG filings on autostereoscopic 3D TV, or 3D viewing on mobile devices: (1) International filing W0/2010/079921 refines depth coding, the system for transmitting a 2D picture along with depth information from which a display screen can construct 3D either as a left-right stereo pair or as a range of left-right views for multi-view autostereoscopic 3D TV. (2) International filings W0 2010/064853, 2010/079880 and W0 2010/085074 all tell how subtitles and closed caption text can be broadcast along with depth control signals that let a 3D receiver display titles and captions at depths that match the main picture content.

(3) US 2009/0195539 tells how LG hopes to help low-cost 3D mobile devices with limited processing power mimic the performance of dedicated videogame consoles or high-powered PCs. The trick is to use the mobile’s camera instead of a joystick or cursor for game control. The camera is taught to recognize a simple pattern, such as two brightly colored fingertip pads, it says. This pattern is mapped into a stored 3D character image such as a fighter or war machine, it says. When the user’s finger tips are moved in front of the camera, the fighter throws punches or the machine attacks. Collision detection software then makes a stored 3D character “fall down or frown,” it says. So the game requires far less processing power than is needed to trace all character movement, it says.