3-D

Display Week 2013 Review: 3-D

Display Week 2013 Review: 3-D

The 3-D technology on the show floor this year was represented primarily by small, glasses-free displays with improved image quality.

by Ken Werner

THE topic of 3-D did not have a promising start at SID’s Display Week 2013.  In his keynote address, Bill Buxton of Microsoft Research said, “3-D [television] was a demonstrably bad idea before it even started.”  He was referring to the industry’s hope that 3-D could enable a new generation of high-margin products that would induce customers to replace the largely commoditized 2-D LCD and plasma TVs they had already bought.  Said Buxton:  “It didn’t work out that way.”

It is widely accepted that 3-D TV is all but dead in the North American market, and three weeks after Buxton made his comment, ESPN put a large additional nail in the coffin by announcing it would discontinue its ESPN 3-D sports channel by the end of this year.

Large-Screen 3-D Largely Absent

One area in which you might think medium- and large-screen 3-D could work is digital signage for advertising.  Of course, the 3-D would have to be autostereoscopic, that is, glasses-free.  And for several years, large autostereoscopic (AS) 3-D demonstration displays could be seen at Display Week and elsewhere.  But there was no AS 3-D signage at the Digital Display Expo in late February and very little at InfoComm in Orlando, which followed Display Week by 3 weeks.

The Display Week exhibition did not deviate from this pattern.  I saw only a modest number of large 3-D screens on the show floor.  Two of these were LG Display’s 55-in. AMOLEDs, in both the flat and curved versions.  Only the curved version was showing 3-D content when I was at the booth, and both versions used passive glasses.

Another 3-D example was from a more surprising source.  Fraunhofer’s Heinrich Hertz Institute (HHI) was showing a moderately large (TV-sized) sample autostereoscopic display with “viewpoint adaptation.”  Although AS 3-D displays often have several viewing zones for different angles of view, they are all best viewed from a specific distance predetermined by the display’s design.  HHI uses an Adobe After Effects plug-in suite to generate multiple sets of views from the standard stereoscopic inputs.  These multiview images are compatible with many existing AS 3-D displays, according to HHI Research Associate Bernd Duckstein.  For the demo at Display Week, there were three fixed viewing distances that Duckstein selected manually, but it is possible to automate the process by detecting the viewer’s distance from the display.

Although the large 3-D displays at this year’s show were not the highlights, there was an assortment of small–to–medium-sized AS 3-D screens, some of which were interesting.

The most compelling 3-D display at Display Week was shown at the I-Zone, the area designated for committee-reviewed table-top exhibits for prototypes and innovative demonstrations.   Space is free to the chosen exhibitors, thanks to the sponsorship of E Ink and the efforts of the volunteers on the selection committee.

The device in question was the HoloVizio Model 80WLT light-field display made by Holografika Kft. in Budapest, Hungary (Fig. 1).

 

Fig. 1:  The author’s finger points to imagery in Holografika’s HoloVizio light-field display.  (Photo:  Ken Werner)

 

The display consisted of 80 projection engines, each producing a 720p image, according to Holografika CTO Peter Tamas Kovacs, but the image on the exhibit floor appeared to have considerably less resolution than 720 lines.  Kovacs said that may have been the result of misalignment produced by jostling in transit.

The display was driven by four GPUs contained in two computers that sat inside the display’s large pedestal and which were connected to the display with 20 dual-DVI cables.  Ideally, said Kovacs, each of the 80 projection engines would show an independently captured image, but a studio session with 80 video cameras is clearly not realistic.  So, the company uses four cameras and synthesizes the 80 separate views from them.

The result of this heavy-duty video processing is a 3-D display with a field of view of 180° and continuous motion parallax that permits the viewer to “look behind” elements of the image.  The 3-D image is viewable from any position in front of the display; there are no dead zones.  The 80WLT is available for €60,000 by special order.  Expect your unit to be shipped 3 months after it is ordered, said Kovacs.

Although the HoloVizio unit is undoubtedly interesting, you will not be seeing very many of them given the price and production rate.  So, it is perhaps fortunate that the bulk of the 3-D displays on the exhibit floor were small AS 3-D LCDs.  Most were unsurprising, but left–right crosstalk is improving on average, and some of the displays were based on native-FHD (1920 × 1080) displays, which does a lot for the image quality of the AS image if the other engineering details are taken care of properly.

Small AS 3-D Displays at the Show

NLT Technologies, formerly NEC LCD Technologies, was demonstrating its multiview AS 3-D H×DP displays in which the horizontal subpixel density is × times that of the vertical subpixel density.  In addition, each of the red, green, and blue subpixels is arranged in rows instead of the conventional columns.  The arrangement, an extension of the company’s Horizontally Double-Density Pixels (HDDP) arrangement, can display both 3-D and 2-D images simultaneously by simply changing the input data.  And, says NLT, it displays “perfect 2-D images” without 3-D/2-D switching and delivers multiple views without reducing the display’s native resolution.

NLT showed a 7.2-in. HDDP 2-D/3-D prototype with viewing angles of 80/80 horizontally and 80/60 vertically, a contrast ratio of 600:1, and a luminance of 370 nits (Fig. 2).

 

Fig. 2:  NLT’s autostereoscopic 7.2-in. 2-D/3-D prototype exhibited very low cross-talk thanks to its glass lenticular lens.  (Photo:  Ken Werner)

 

In addition, the display incorporated glass lenticular lenses instead of polymer.  The result, explained NLT’s Engineering Manager Bob Dunhouse, is less left–right cross-talk because glass is more dimensionally stable under prolonged heating by the backlight than is polymer.  The claim was supported by a side-by-side comparison and an analysis that showed that the Qualified Binocular Viewing Space (QBVS) of a display with the glass lens is twice that of conventional displays.

Innolux showed a 4.5-in. 2-D/3-D display with 1280 × 720 pixels in 2-D and 640 × 720 in 3-D.  Luminance in 2-D was 450 nits and 225 nits in 3-D.  The interesting thing about the display was that it could show a 3-D image in both landscape [Fig. 3(a)] and portrait [Fig. 3(b)] modes simply by being rotated 90°.  The display used a 2-D/3-D switchable barrier.

 

    

Fig. 3:  Innolux 4.5-in. 2-D/3-D autostereoscopic display was able to show 3-D images in both (a) landscape and (b) portrait orientations.  (Photo:  Ken Werner)

 

Next on the Innolux counter was a similar display with eye tracking.  The angular range over which the 3-D eye tracking operated was rather limited, but an icon in the corner indicated when the image left the active range and had automatically defaulted to 2-D.

Japan Display, Inc.  (JDI) showed an automotive display in which an LC parallax barrier was switched by tracking the viewer’s head position, so the viewer’s (presumably the driver’s) head was always in the display’s sweet spot.  The display was 12.2 in. on the diagonal with a native 1920 × 720 pixels; the 3-D resolution was 960 × 720 (Fig. 4).

 

Fig. 4:  JDI’s 12.2-in. autostereoscopic automotive display utilized head tracking to keep the driver’s eyes in the display’s sweet spot.  (Photo:  Ken Werner)

 

Tianma Microelectronics showed a WVGA parallax-barrier 3-D module that produced 350 nits in 2-D and 180 nits in 3-D with a contrast ratio of 800.

So, there was quite a bit of 3-D at Display Week after all if you looked at the industrial purveyors of smaller displays.  And these purveyors are learning how to make displays with less cross-talk and more forgiving 3-D sweet spots.  It is clear that eye tracking is the way to go for larger (but not large), single-user AS 3-D displays, but is it needed for a hand-held display in which the user can readily – even unconsciously – adjust the angle of view with a slight rotation of his or her hand.?  Consumers will make that decision for themselves – if head-tracking AS 3-D displays get enough design wins to give consumers the chance.  •

 


Ken Werner is Principal of Nutmeg Consultants, specializing in the display industry, display manufacturing, display technology, and display applications.  He serves as Director of Marketing for Tannas Electronic Displays and is a regular contributor to HDTVexpert.com and Insight Media’s Display Daily.  He can be reached at kwerner@nutmegconsultants.com..