LG, RealD Mum on Possible 3D TV Collaboration at CES

Further patent details are emerging about LG’s development work on active 3D TV displays that can be viewed with the type of inexpensive passive polarization glasses that RealD hands out in theaters (CED Dec 17 p1). Used instead of expensive active-shutter glasses, the displays deliver full 1080p HD to both eyes instead of the half-resolution HD available from existing LG polarizing sets which cover the display with passive filter strips.

The main filing on this idea (US 2010/0007716) names three Korean inventors, Seung-Chul Lee, Hoon Kang and Sung-Min Jung, and describes how an auxiliary active panel is secured over an otherwise conventional LCD, plasma or OLED screen. The auxiliary panel is rapidly switched on and off to rotate the circular polarization of the screen picture by 90 degrees, the filing says. The screen displays a synchronized sequence of alternate left- and right-eye images at extremely high speeds to avoid flicker, it says.

Viewers wear passive polarization glasses that let the left eye see only the left screen image, while the right eye sees only the right screen image. So LG is in essence making a TV set behave like a RealD theater projector. LG and RealD representatives were mum when we asked them by e-mail whether the companies plan to discuss at next week’s CES any collaborations that involve developing a full HD 3D TV display that’s compatible with the passive glasses that RealD distributes at movie theaters. RealD is “working with our licensees to incorporate RealD branding in their consumer electronics product advertising, marketing and packaging and to have our brand featured prominently on our patented RealD eyewear used in the 3D consumer electronics market,” RealD said in recent registration statements filed at the SEC.

Unlike LG’s existing passive polarization sets, which display the left and right images simultaneously as interlaced lines, the new system lets each eye see a full HD image with all its lines, the patent filing says. It gives a better balance between horizontal and vertical viewing angles, the filing says. It also avoids any unwanted “pseudoscopic phenomenon” when the limited vertical viewing angle of passive filter screens can force the left eye to see the right-eye image and vice versa, it says. It also lets the screen perform better as a 2D display, it says. For 2D, the auxiliary panel is held in one switched state, with improved 2D luminance because there are no permanently attached filter strips to reduce the screen’s light output, it says. Factory construction, says LG, is facilitated by alignment films that are secured to the display panels.

After this key filing, which was first lodged in July 2008 by LG Display, six engineers working for sister company LG Chem Ltd. of Seoul filed for international patents on methods of making optical alignment filters for 3D screens by irradiating polymer film with ultraviolet light (WO 2010/090429). This, say the inventors, improves manufacturing yield rate and productivity.