Some Thoughts on RealD’s Passive 3DTV Technology
The catalyst for today’s Display Daily article was a comment offered by Josh Greer, the President and Co-founder of RealD at the 3rd Annual 3D Entertainment Summit recently held in Burbank. Greer stated that consumer electronics companies are targeting April 2011 for an initial offering of LCD 3DTV’s utilizing passive polarized glasses and based on RealD’s ZScreen technology.
This article is a "think-through" of the prospects for this technology as a competitor in the home 3DTV marketplace. Let’s start with a quick lay-of-the-land.
The current state of the art in 3DTV technology is based on the use of shutter glasses. The advantages of this approach include the production of a decent 3D image and the fact that the technology can be integrated into current generation LCD and plasma displays at little additional cost. The consumer is basically buying a conventional, albeit higher end, 2DTV. If they want to enable the 3D option, then they spend the money to buy "expensive" shutter glasses. The other disadvantage is, of course, the awkwardness associated with wearing shutter glasses.
At the other extreme, the Holy Grail in 3DTV is a glasses free technology. Despite recent developments in such technologies, the simple fact is that it is just not ready for prime time and commercial products are likely years off.
This leaves the middle ground: 3DTV based on passive glasses. Such an approach has users wearing inexpensive and presumably comfortable glasses. These glasses do not require batteries or an IR emitter.
One such passive technology has been around for a while. It is called patterned retarder or MicroPol. To implement this technology, a sheet consisting of an array of waveplate stripes is precisely positioned on the front of the LCD. This is an expensive component. Adding to the expense is that fact that the logistics of the supply chain are very unfavorable with fabrication and application of the patterned retarder sheet currently available principally from a single supplier based in Japan. Other disadvantages of the approach include the fact that the vertical resolution of the 3D image is reduced by half and the vertical viewing cone is quite restricted. Although undesirable, neither of these later disadvantages are necessarily killer problems.
RealD’s flat screen ZScreen approach is likely a descendent of the computer monitor ZScreen developed by the seminal 3D company, StereoGraphics, which was acquired by RealD in 2005. It is basically a screen-sized electro-optical polarization switch. As was the case for the patterned retarder sheet, the addition of a ZScreen constitutes an expensive modification to a conventional LCD 2DTV.
The ZScreen approach does, however, have an important advantage. Since the ZScreen operates in a time sequential mode, the resolution in the 3D mode is not reduced from that presented by the display in the 2D mode. Another potential advantage is that in principle, it can be cost effectively produced by existing manufacturers of LCDs and assembled by existing module makers.
On the down side, the addition of the ZScreen does introduce a reduction in image brightness, as well as some angular dependence to the quality of the 3D image.
When the advantages and disadvantages are added up, the patterned retarder approach has not been able to capture any market share. The story for the ZScreen may be different. Greer set reasonable expectations by stating that he does not anticipate the RealD passive 3D approach to replace current shutter glasses based 3DTV offerings but, rather, to co-exist and carve out a portion of the market. I would agree, the combination of advantages and trade-offs offered by the ZScreen approach should allow it to achieve this modest level of success.
By Art Berman, Display Daily
