Key RealD 3D Patents Nearing Expiration, But Newer Ones Have Legs

The building blocks of 3D video are becoming public property as basic patents die of old age, a Consumer Electronics Daily patent search has found. Much like what happened with stereo sound, where master patents filed in the U.S. and U.K. in the 1930s had expired by the time stereo standards were set in the 1950s, 3D pioneers were so far ahead of their time that key patents are expiring before home 3D product sales even begin to take off.

Some of those expiring patents are held by 3D technology developer RealD. But, we've also found that newer patent filings -- not immediately apparent from routine searches and not identified to us by RealD -- break new ground and might pave the way for intriguing legal battles in the future. Our investigation was prompted by recent announcements from RealD that it has licensed its technology to CE companies JVC, Panasonic, Samsung, Sony and Toshiba -- and the lack of technical detail in those announcements. It’s the latest in a series of reports profiling the patent portfolios of 3D’s leading IP holders, like Sensio Technologies (CED Feb 3 p1) and Sony (CED April 9 p1).

Anyone searching for patents under the RealD name is unlikely to find any, for two reasons. RealD’s original patents came with its acquisition of Stereographics Corp. in February 2005. Stereographics’ patent filings date back to 1981 and in the U.S., like most other countries, patents usually can’t last longer than 20 years from the date of filing. Several dozen more recent filings are under a name that is different enough from RealD’s customary trading-name to elude standard patent searches. Because of the large number of patents, we'll deal with the before-and-after IP folios in separate reports.

We found 31 U.S. patents from Stereographics filed since the 1980s. Among them, U.S. patent 5,193,000 for “Multiplexing technique for stereoscopic video” delivers frame-sequential 3D, using existing transmission and recording channels with standard 2D bandwidth, so only a new TV is needed to watch 3D. This is achieved by digitally squeezing the left and right images side-by-side into a single picture frame. The horizontal lines of both images are compressed to half length, so that both the images fit into the width normally occupied by one image. The “stereoplexed” images are un-squeezed to restore them to full, normal width for sequential display. The patent was filed in August 1991, and like all StereoGraphics’ patents, names Lenny Lipton as sole or joint inventor. This basic patent on “side by side” compression, as used by 3D broadcasters, can be expected to expire in August 2011.

StereoGraphics’ U.S. patent 4,523,226 was filed in 1983, and protected the basic idea of “top and bottom” or “above and below” 3D coding. The left and right images are vertically squashed so they can fit one above the other in a standard picture frame, and are separated electronically by extra sync pulses. The vertically, anamorphically-squashed images are separated and expanded to full height to fill a full picture frame, and alternately displayed at 120 Hz -- twice the normal rate -- for flicker-free 3D viewed either by active-shutter or passive-polarized glasses. This, the inventors said in later patents, became a standard approach for computer display because a PC graphics card easily converts the 60Hz double-image signal to a 120 Hz field-sequential stream. Based on the 20-year rule, this patent has already expired.

An alternative approach, covered by U.S. patent 4,562,463 for a “Stereoscopic Television System with field storage for sequential display of right and left images,” was filed in 1981. The left and right images are captured without compression, but at half the target display-rate of 120 Hz. So, existing bandwidths can cope. To avoid fatiguing flicker and motion artifacts, memory in the playback device stores each picture and displays it twice. Based on the 20 year rule, this patent also has expired.

Two more recent StereoGraphics patents have many years of life left to run in RealD’s U.S. portfolio. One, U.S. 7,002,618 filed in 2002, covers a “Plano-stereoscopic DVD movie.” The 3D is recorded on a DVD using the side-by-side format, which works well with MPEG-2 compression and benefits from DVD’s rich horizontal resolution. So-called Stereoscopic Media Player software is installed on the PC to convert the side-by-side images from the DVD, to the top-bottom/above-below format suited to PC display, on the fly.

Another 2002 patent, U.S. 7,184,002, for “Above and Below stereoscopic format with signifier,” refines above-below/top-bottom coding by burying “signifier” codes in the picture. A few carefully sequenced, carefully placed and not—too-bright red, green and blue pixels should be invisible to the viewer, but recognizable by the PC as clear instruction to treat only a 3D signal as 3D. This prevents the PC from mistaking full-frame 2D material for top-bottom 3D, so it doesn’t incorrectly process the images as 3D and generate an unusable picture.

We asked RealD to comment on the expiry of key patents and to point us to any other patents or applications that the company regards as significant. The company only would say “RealD has an extensive IP portfolio covering both patents and proprietary knowhow related to many areas of our business. This includes innovation across display, projection, content delivery, eyewear and more. While it is company policy to not discuss our technology development, we feel strongly about our technology platform and the companies we have partnered with including Sony, Panasonic, Samsung, JVC and Toshiba for the upcoming launch of 3D in the home is an endorsement for our innovative technology.”

RealD’s reply didn’t mention that it has been filing patent applications of its own invention under the name “Real D.” We only discovered that independently while searching 3D patents of yet another company. At last count, there were 36 applications filed by “Real D” that we'll cover in a follow-up report.

Meanwhile, we then conducted further searches of the StereoGraphics IP acquired by RealD, and found a pending U.S. application (2007/0263169) filed in 2006 for “3-D Eyewear,’ which describes 3D glasses that can be clipped onto prescription spectacles. We also found 13 international filings by StereoGraphics, several of them for autostereoscopic or glasses-free systems. The applications include WO 2007/043988 from 2005 for a “Method and apparatus for optimizing the viewing of a lenticular stereogram,” WO 2007/040471 from 2005 for an “Autostereoscopic lens sheet with planar areas,” WO 2000/043821 from 2000 for a “Method and apparatus for maximizing the viewing zone of a lenticular stereogram,” WO 2000/028517 from 1999 for a “Parallax panoramagram having improved depth and sharpness” and WO 1998/027456 from 1997 for a “Synthetic panoramagram."

Other StereoGraphics filings include a “Stereoscopic format converter” from 2005 (WO 2007/040472), a “Camera controller for stereoscopic video system” from 1994 (WO 1994/021086), a top-and-bottom/above-and-below “Stereoscopic television system (WO 1983/002706) from 1983. There also are filings on active lenses -- WO 1998/054614 from 1998 on “Electrostereoscopic eyewear,” WO 1998/044746 from 1998 for a “Polarizing modulator for an electronic stereoscopic display,” WO 1996/013129 from 1995 for “Universal electronic stereoscopic display,” WO 1995/022074 from 1994 for “Wireless active eyewear for stereoscopic applications” and WO 1989/004504 from 1988 for an “An achromatic liquid crystal shutter for stereoscopic and other applications."

Although patents expire, the know-how learned from practical experience, and often bundled into a patent license, can be as valuable as the patents themselves. Trademarks that consumers already know and trust can be very valuable too, as evidenced by Dolby Labs’ tight control of the Dolby name on audio and video hardware and theater systems. Industry insiders commend RealD’s strategy of making 3D bolt-on hardware that is quick and easy for theaters to install.