E Ink Tricks the Eye with Color -- and Paper

By Jenny Donelan

The E Ink booth is always a fun place to visit at Display Week, probably because it features so many different products, some “real,” some prototypes. E Ink is a versatile material and designers are still figuring out what they can do with it. This year, the range of products on display included shelf labels, smartphones, blood sugar monitors, and decorative pillars featuring dynamic color displays that were part of the actual booth.

One of E Ink’s big announcements at the show was the addition of yellow to its Spectra product line. Last year, Spectra debuted in black, white, and red. This year, you can get black, white, and yellow as well. The product has various uses, including electronic signage and dynamic shelf labeling. E Ink was demonstrating the latter with an exterior booth wall that featured a life-sized photo of shirts on shelves, as if at a store, with actual Spectra shelf labels next to them. From a distance, the whole eye-catching display looked real, as if there were actual shirts on shelves, What’s really interesting, said E Ink’s Giovanni Mancini, was that more than one attendee asked him what kind of display the shirts were being shown on -- to which he had to answer that it was one of the oldest display materials in the world – paper.

There’s been a lot of talk recently about how the e-Reader market has matured, and it has, but E Ink is still shipping 10 to 12 million panels a year, noted Mancini. No doubt many companies would be happy to be serving a “mature” market in that capacity.

Still, E ink has obviously seen fit to diversify its offerings, with a recent emphasis on the electronic signage market. And in January, it announced Prism, which the company describes as a “dynamic architecture product.” Prism uses electronic ink to decorate surfaces such as walls, artwork, pillars, and so forth, much as LEDs are now being used, but with a softer look and of course, with less power consumption. At the show, two different colors of Prism were used to decorate the sides of pillars in one corner of the booth. The colors changed in intensity: one pillar started out as nearly white, became pink, and then red before fading out to start over again.

Prism is available in a wide range of colors, some of which are shown here.

Silicon Hot Melt Is Alternative to Polyurethane Hot Melt and DS Tape

By Ken Werner

At a Display Week poster session on Thursday, June 4, Ryan Schneider, Glenn Gordon, and colleagues from Dow Corning presented their paper, "Silicon Hot-Melt Adhesive Providing Protection, Waterproofing and Reworkability for Precision Assembly of Electronic Devices" -- a title that leaves little to the imagination.

The material, Dow Corning EA-4600 HM RTV Black, was initially developed as an alternative to double-sided tape (and polyurethane hot melt) in the assembly of cell phones and other electronic devices. In this role, the adhesive can run about 20% of the cost of tape in large-volume applications. Because the material requires dispensing equipment that costs in the vicinity of $100,000, it takes high volumes for the much lower material cost to deliver its maximum savings.

One advantage of the silicon hot melt is that it can be used to make beads of 0.5mm or less in, for example, a peripheral seal on cellphone window glass, where maximum screen visibility is crucial. It is, said Gordon, impossible to cut DS tape that fine.

Although the original conception was to use the hot melt as an adhesive for assembly, if you deposit a peripheral bead on only one surface and allow it to cure, it forms a gasket that can be used to provide water- and dust-proofing to a snap-on cover -- and the cover can be removed and re-snapped indefinitely while still retaining its water-proofing characteristics. This approach was used to waterproof the back cover of a recent, popular smartphone model. Although Schneider and Gordon would not identify the model in question, reliable industry sources tell me it was the Samsung Galaxy S5. Dow Corning is talking to other manufacturers about adopting the technique.

Ryan F. Schneider (R) and  Glenn V. Gordon of Dow Corning seemed pleased at the reception of their poster paper.  (Photo:  Ken Werner)

The View From The Standards Podium

 By Tom Fiske

I had the privilege to chair a session at the Symposium Thursday morning on display standards and transparent displays. This session was run by the Display Measurement topical subcommittee, part of the program committee that puts together the conference. Marja Salmimaa from Nokia Technologies (Finland) was my co-chair.

It’s always satisfying when a session that you assembled back in January at the paper selection meeting really comes together at the conference in June. This one demonstrated one of the best things about the conference -- its international nature. Five countries and three continents were represented.

Michael Becker from Instrument Systems (Germany) gave the first invited paper, a very nice overview of the main emphases of the various major standards organizations concerned with displays. Why do we need standards? They fill the need for clear communication between different groups and countries by supplying precise terminology and the taxonomy that provides structure for the terminology. The CIE concerns itself with the fundamentals of photometry and colorimetry. The IEC provides data sheets and standards for display components and devices. The ISO deals with the ergonomics of human-system interaction. He covered some highlights of recent work by those organizations, including measurements for non-planar (curved) light sources and displays, OLED performance in various ambient lighting environments, transparent displays, and the characterization of speckle in optical systems. He concluded his talk by remarking on the complementary topics emphasized by each organization and how cooperation between them is good for the standards setting enterprise.

Kei Hyodo (pictured above) of Konica Minolta (Japan) is Assistant Secretary for IEC TC 110, the group that covers electronic display devices. In the second invited paper, he discussed the history and structure of the IEC TC 110 and highlighted some of the new topics that the working groups are currently engaged in, including touch, lasers, curved displays, and wearable displays. He emphasized the good working relationship with SID and the ICDM.

Xin-Li Ma from BOE (China) gave a nice talk about optical measurement methods for transparent LCDs. He focused mainly on the effect of the display on objects that are viewed behind the display. He discussed the effect on MTF, level of transparency, and color distortion.

The session finished up with a pair of talks from John Penczek and Paul Boynton from NIST (USA). They covered a general framework for characterizing transparent displays and suggested measurement techniques. These were extensions and applications of techniques found in the Reflection Measurements section of the IDMS. They emphasized that reflectance and transmittance factors can be measured and then used to predict the performance of transparent displays in a variety of lighting environments. In other words, take advantage of linear superposition and don’t try to recreate specific lighting environments in order to characterize display performance in various conditions.

CSOT Brings Curved 110-in, Set to Display Week

 By Steve Sechrist 

Not to be outdone by rival Chinese fab BOE, Shenzhen-based China Star Optoelectronics Technology (CSOT for short) was at Display Week showing off its 110-inch curved 4K TV, claiming it as the “world’s largest" curved LCD TV, with dimensions of 2.4 x 1.4 meters. The set includes a 3840 x 2160 pixel (4K x 2K) pixel display in a 110-inch diagonal curved format that offers a sizeable color gamut with 10 bit color at 60 Hz refresh, and a whopping 50K:1 contrast. CSOT product engineer Yuming Mo told us that at its thinnest point, the curved set reached 20mm in thickness (at the edges), growing to 45 cm with a curve radius of 5500 mm total.     

The company also showed a UHD (3840 x 2160 pixel) 55-inch diagonal TV. The set incorporates QD Vision's Quantum Dot technology and claims a 63% boost to color gamut, achieving an extremely impressive color standard with what the company is calling its Super Color Gamut technology. 

Clearly Chinese fabs are serious in their efforts to step up their technology offerings and many experts believe they have reached image parity with some of the best displays in the industry. We agree, and look forward to the consumer benefits from these awesome displays.

Author Steve Sechrist (third from right) stands with the team from CSOT in front of the company’s 110-in. display.

Android Wear Offers Timely Advice to Display Makers

By Ken Werner

On Thursday morning at Display Week, The Special Wearables Address in the business track was given by Sidney Chang, Head of Business Development for Android Wear, whose topic was "Android Wear Overview and Google's Wish List." (Chang replaced Fossil CTO Philip Thompson, whose scheduled talk was "Why Wearables with a Display Will Not Succeed with Today's Display Companies." I have ​been assured that the switch was due to a scheduling conflict and not because Thompson was planning on telling us, quite accurately, that display and computer companies can't be trusted to design watches.)

Chang's approach was not confrontational, but he had interesting things to say, some of them aimed directly at display makers. The first was that display makers should think very hard about "improving" traditional display parameters if they impact battery life. Although outdoor visibility is essential, it should be done in ways other than cranking up the luminance. The display must always be on, but it doesn't always have to be on in the same way.  Chang described two modes. The "interactive mode" has full animation and full refresh rate. "Ambient mode" has reduced color depth, reduced brightness, and reduced refresh rate for showing basic information, like the time, whenever the user looks. (Pixtronix and Sharp, are you listening?)

Chang specifically discouraged display makers from going to 300 ppi for watch displays. The extra pixel density isn't needed for most watch apps, he said, and most watches can't tolerate the hit on battery life. 

Chang showed the results of user studies done by Android Wear. Not surprisingly, users want the thinnest watch they can get. Many women feel that current watches, although arguably appropriate for men's generally larger wrists, are too large for theirs. Average wrist diameters are 17.5cm for men and 15.0cm for women. Average wrist breadths are 5.8cm for men and 5.2cm for women. When a group of users (presumably both male and female) were asked whether they preferred a watch diameter of 1.0, 1.1, 1.2, or 1.3 inches, there was a strong bi-modal preference of 1.0 and 1.2 inches.  Of these, participants over 40 years old preferred the smaller size, while participants under 40 preferred the larger. (Display makers, don't try to sell 1.5-inch displays to watchmakers!)

A general issue is trying to meld the very different approaches of watchmakers and people from the display and mobile systems communities. Chang noted that watchmakers and watch users prefer choice and variety. In 2014 Fossil had 8000 watch SKUs under 15 different brands. Typical sales for each SKU were thousands to tens of thousands. Since Google Wear released its API, the most popule apps have been different watch faces, with one app allowing the user to take a selfie of his or her clothing and then match the color of the watch face to the color of the clothes.

Forging compatibility between the watchmakers' need for variety and the display- and system-makers need for volume will be an ongoing topic of conversation.

The ICDM Seeks to Raise The Bar - But Will It Be High Enough?

By Tom Fiske

The International Committee for Display Metrology (ICDM) is one of the strongest groups working on standardizing display metrology procedures and techniques. Its members are some of the best display evaluation and characterization experts in the world.

On Tuesday evening, the ICDM had its main meeting. The meeting started with an update of organization activities and proposals for a potential quality certification program and the institution of a student award for metrology.

Things really got going with a number of presentations and proposals from various members for a variety of methods to address some of the most pressing issues in display metrology. A couple of members talked about various problems with and offered some suggestions to improve current methods for measuring and reporting contrast ratio -- especially as it relates to projectors and High Dynamic Range (HDR) displays. There are a couple of ways that ANSI (checkerboard) contrast gives misleading results for projectors -- especially as it relates to typical cinema content. Current contrast methods don’t adequately address dual resolution HDR displays, either.

We also had a couple of good reports about how to evaluate light field and other types of 3D displays. Light field displays are becoming more prominent lately, so this is a welcome development. We had a proposal to update the flicker measurement method in the current IDMS. The new method will be simpler to calculate and be more general. There was a presentation proposing a display quality metric that combines resolution, contrast, luminance, display size, and color gamut. This was nicely correlated to a set of very thorough subjective assessment results.

One of our guests had a nice rant on the evils of specsmanship. He enjoined the ICDM members to join with other parts of the industry to combat misleading reports of display performance. My own view is that part of the reason the IDMS was adopted was to give the industry a definitive set of display evaluation methods. That’s a great starting point, but the ICDM can only do so much. We can certainly raise the banner of how to measure displays properly, but it’s up to the industry as a whole to embrace “no misleading” behavior. What are the chances of that, I wonder?

The ICDM welcomes participation from those interested in these topics. It is a committee within the SID and publishes the Information Display Measurements Standard (IDMS).

10K from BOE Debuts at Display Week

By Steve Sechrist

BOE showed off an impressive 10K display at Display Week. The 10240 x 4320 pixel display (in 21:9 format) is a “technical development” model that comes in a large 82-inch diagonal display, according to development engineer XinXin Mu of BOE. She told us the panel is a one-off that demonstrates the cutting edge of the high-resolution capabilities of BOE as the company begins looking downstream at the future of both display size and resolution. The panel uses a direct LED backlit scheme that is the major reason this behemoth set consumes a whopping 1100W of power. She also said pixel addressing is done from both top and bottom, and uses a standard ASi backplane.   

Even at close-in distance, individual pixels were beyond human visual acuity (at least this human’s pair of eyes) and close inspection of the amazing video images (provided by an upscaled NHK source) revealed such minute detail like a single bird discernable in a wide city view shot, sitting atop the Brandenburg Gate, or details of the rotating restaurant from a distance shot of the Berlin tower. The images are simply stunning. 

BOE PR rep Aly Langfeifei told us the display is meant to underscore just how far China based fabs, (and BOE in particular) have progressed in their technology development, 

So take the opportunity to treat your eyes to the future of displays with this 10K beauty. We were also told work is going on to modify the technology and prepare it for commercial release in the (not too distant) future.

Xinxin Mu, Lt, Aly Langfeifei