Small, Steady Steps for AS Displays

The bulk of the 3D displays on the Display Week 2013 exhibit floor were small autostereoscopic (no glasses) LCDs.  Most were unsurprising, but left-right crosstalk is improving on average, and some of the displays were based on native-FHD (1920 x 1080), which does a lot for the quality of the autosteroscopic image if the other engineering details are taken care of properly.

Here are a couple of the more interesting small AS-3D displays on the show floor last week:

NLT Technologies, formerly NEC LCD Technologies,  was demonstrating its multiview AS-3D HxDP displays in which the horizontal sub-pixel density is x times that of the vertical subpixel density.  In addition, each of the red, green, and blue sub-pixels are arranged in rows instead of the traditional columns.  The arrangement, an extension of the company's HDDP (Horizontally Double-Density Pixels) arrangement, can display both 3D and 2D images simultaneously by simply changing the input data.  And, says NLT, it displays "perfect 2D images" without 3D/2D switching, as well as delivering multiple views without reducing the display's native resolution.

NLT showed a 7.2-inch HDDP 2D/3D prototype with viewing angles of 80/80 horizontally and 80/60 vertically, a contrast ratio of 600:1, and a luminance of 370 nits.  In addition, the display incorporated glass lenticular lenses instead of polymer.  The result, said 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-inch 2D/3D display with 1280 x 720 pixels in 2D and 640 x 720 in 3D.  Luminance in 2D was 450 nits and 225 nits in 3D.  The interesting thing about the display was that it could show a 3D image in both landscape and portrait modes simply if you rotated it 90 degrees.  The display used a 2D/3D switchable barrier.

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

It is clear that eye-tracking is the way to go for larger, single-user 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? –Ken Werner