LCD: The Next Generation | DisplaySearch Blog

Blogging Live from SID Display Week!

It is hard to believe that only five years ago, at SID International Symposium 2004, consumer LCD TV sets represented new technology. By this year’s symposium, almost all TV sets sold in developed nations were LCD units. Most TV sets selling in China are LCD units, already. Some people wrongly assume such success means LCD technology is ready for replacement by newer flat panel technology. There are certainly many interesting alternative display technologies demonstrated or described at the symposium, but none of them have the momentum of a $100 billion supply chain expanding 25% a year.

Two demonstrations at SID this week underscore this point. Engineers from Sharp’s Research and Development Group are showing a 60″ 1080p TFT LCD module using five primary colors. This is significant because they prove it possible to display 99% or more of all the surface colors found in real life. No other display technology has ever delivered such realism. Most professional monitors deliver 88% or less. In addition, they prove it is possible to preserve such realistic color when the panel is viewed off axis. Instead of conventional red, green, blue (RGB) stripes on the color filter, they added cyan, yellow and a second red stripe to create a RCGRBY six-stripe sub-pixel pattern. This means there are more than 65 thousand ways to create each color. In a conventional LCD there is only one way to create a given color, so designers must accept whatever off-axis color shift results. Not so with a five-color design, the Sharp team discovered how to minimize off-axis color shift for each color and developed a decoding algorithm that converts standard RGB image data into optimal color codes for their system.

This is indicates that accurate color reproduction can come from a simple change to the color filter. Conventional, low-cost backlights and other components can be used. Digital cameras capture far many more colors than any TV or monitor can display today and professional cameras capture even more. We may soon be able to see life-like images at no additional cost.

The potential application of five-primary systems to handheld products may be more significant. One of the barriers to implementing field-sequential color LCD as an alternative to color-filter designs has been color break-up people can see if the field rate is to slow. Using more than three primary colors tricks the eye into perceiving faster field switching, so slower liquid crystal modes may be possible. The implication is that panel makers could supply high-resolution, full-color, full-video displays using only 25% of the power required today. Handset or e-book designers could increase battery life and decrease product weight with such displays.

Samsung showed it was possible to strobe conventional CCFL backlights so fast that they could send video signals as light pulses. That should put an end to the worry that low-cost backlights were not fast enough for field sequential LCD. The Samsung demo shows that about 1Mbps is possible, more than enough to transmit coupon data or promotional URL to someone’s handset as they look at an advertisement. Alternatively, that is plenty of bandwidth to send map data to someone’s handset while they are looking at a kiosk or directory display in a train station.

All this-and more-is possible with the existing TFT LCD supply chain. In the next five years, we will see the next generation of LCD technology, everywhere.

http://www.displaysearch.com Paul Gray

While I can see the point of a 5- or 6-primary system for CAD, desktop publishing and photo-editing applications, I’m not convinced about it for TV or home usage.
1 It will further increase the level of data necessary, putting a strain on delivery systems (disk or download). Most US satellite in HD today is 1440x1080i. Why? Because it’s cheaper and few consumers can see the difference.
2 Costs of video processing will go up: more pixels, more color space, more memory and calculations.
3 Broadcasters will have to re-equip cameras, studios and production facilities, exactly at the time that TV and video production is under threat from fragmentation of advertising.
http://www.DisplaySearch.com David Barnes

I would agree with you, Paul, if the five-primary system required extra bits. It does not. The colors are mapped from the standard tri-stimulus (RGB) coordinates. All professional and many consumer cameras generate coordinates outside the sRGB color region. The same holds for many standard DVD.

If five or six primary systems became popular, we might see movie producers investing in cameras with wider gamuts. On the other hand, they may reinvest for other reasons as well, such as direct digital-to-digital distribution or 3-D creation.
http://www.linkedin.com/in/paulfredrickson Paul Fredrickson

David,

This sounds very much like the Genoa Color Technologies 5 color, multi-primary approach that has been shown at past SID exhibitions and other shows and has been promoted in variants as you describe with one color repeated using 6 sub-pixels. They have published blind consumer testing through Quixel research comparing a conventional RGB LCD a few years back showing a strong consumer preference for the multi-primary image. Is the Sharp program demonstrated at SID based on the Genoa system?

The off axis color performance sounds unique to Sharp and is certainly another welcome improvement that has not had enough attention in LCD displays.

It seems to me a multi-primary approach gives display manufacturers options to give them some real bang for the buck product differentiation (more margin!) sorely needed in the industry and one that could be implemented relatively quickly in a first stage with multi-primary sub pixels followed later by a sequential color LCD that would offer significantly more radical improvements in many dimensions.

Paul Fredrickson