It might be impossible to foresee the future in absolute terms, but experts in a given field can discuss general trends with a degree of accuracy. For this special Display Week issue, Information Display invited an expert analyst who has covered the display industry for many years to predict the progress of trends in five key areas: flexible substrates, display standards, 3-D, high resolution, and touch panels. Read on to find out what display capabilities you will be using, buying, and manufacturing in years to come.
by Mark Fihn
IT IS SOMEWHAT AMAZING to realize that only a decade ago, top display industry analysts had debates about whether or not mobile-phone displays would shift from monochrome to color, TV market pundits debated about whether or not HDTV would become a reality, and even leading computer companies such as Apple scoffed at Microsoft's vision of a world filled with tablet PCs that could be manipulated with touch-based inputs.
This article draws on many years of participation, observation, and writing about the display industry. While unlikely to serve as a predictive tool, many of the ensuing observations attempt to draw attention to those areas where it is desirable for display performance to better mimic the human visual experience. The article is divided into five segments, drawing from insights gained through Veritas et Visus publications that cover flexible substrates, dis-play standards, 3-D, high resolution, and touch panels. Each segment, somewhat provocatively, suggests five trends to watch for in the future – a total of 25 predictions in all.
Flexible Substrates
The notion of a flexible display is fascinating, with many forward-thinking people envisioning a world where displays essentially displace paper both in function and form. Over the years, however, the appeal of flexible displays has largely been overshadowed by a focus on enabling electronic devices to be manufactured on flexible substrates. With displays at the top end of the electronics food chain, recent attention related to flexible substrates has shifted to somewhat simpler devices such as sensors, ID tags, batteries, lighting, and photovoltaics. While flexible displays still evoke considerable interest, simpler devices are already starting to lead what is going to be a fundamental shift in the way electronic devices are manufactured and used.
1. In the race to enable big images from small packages, pico-projectors are winning. The original promise of flexible-display technologies was to unfold or unroll a small device so that a much larger image might be displayed. Although pico-projection still has some hurdles, it is becoming increasingly clear that at least for the next few years, the promise of big images from tiny devices is best fulfilled by projection technologies and not by rollable or foldable displays.
2. The Kindle/Nook stand-alone e-Book phenomenon will fade. Certainly, mono-chrome e-Book readers are going to put up a good fight against the likes of the iPad, but the era of single-function devices is coming to an end. e-Book makers must quickly recognize the desire by users to not only read books, but to browse the Internet, play games, jot down notes, show off photo albums, link to TVs, etc. These multiple demands on the device make it particularly difficult to shift to flexible displays. Ever seen a rollable DVD drive?
3. Integrated devices. To this point in the electronics industry, most devices have remained stand-alone solutions. Processors have remained processors; memory has remained memory; mass storage, optical storage, batteries, input devices, etc., have all been manufactured independently from one another, and then combined by another party to create a PC, or a TV, or a mobile phone. The new manufacturing processes being developed in the emerging printed electronics industry will increasingly enable several of these devices to be manufactured simultaneously. The "system-on-glass" process that has been proposed by several LCD makers over the past decade will be fulfilled, not on glass, but on substrates that utilize printing processes similar to those used to print on paper.
4. Wearable displays. While evening gowns with interwoven optical fibers and t-shirts that brightly proclaim your emotions might not suit everyone, there is no question that wearable electronics is coming very quickly. And this will certainly include displays. Think of military clothing that enables adjustable camouflage; clothing accessories that can change color depending on the outfit; clothing with embedded ID badges; or clothing that reacts to dangerous situations by changing color in the presence of a certain chemical or a certain medical condition.
5. e-skins. One of the most exciting developments in the world of displays is related to e-skin technology. The ability to change a surface electronically, from one color to another, or even in a matrix of colors, really serves to redefine the notion of a "display." This is much more than changing the color of the casing on your mobile phone; it ultimately includes the ability to change almost any surface. If wallpaper, upholstery, carpeting, flooring, and indeed paint itself can be changed with the push of a button, or based on the time of day or the intensity of the sun, it suddenly becomes hard to put a limit on what we describe as a display. Such solutions, however, will not emerge out of multi-billion-dollar fabs based on glass substrates dependent on vacuum deposition and photolithographic processes. e-skins belong to the world of printed electronics, utilizing flexible substrates that someday will be printable in an inexpensive home environment.
Display Standards
Discussions about standards usually make their way into the press either when a standard fails or when conflicting "standards" result in a "war." Display-related standards and regulations fall into a broad range of activities – from metrology to performance, to environmental considerations, to interface factors, to industry-specific documentation, and to government-specific political aims. In most cases, the biggest issues related to standardization arise because of too many standards bodies and not because the world lacks standards.
1. The ICDM will improve, but not solve, display-related specsmanship issues. Specsmanship involves the creative use of standards to overstate performance. In the display industry, specsmanship has made a meaningless hash out of performance parameters such as contrast ratio, color gamut, viewing angle, brightness, and numerous other measures. Although the long-awaited ICDM metrology specifications should help reduce the specsmanship, it is greatly feared that the creativity of marketers will continue to confuse the marketplace, rather than providing users with meaningful performance comparisons.
2. The battle for a unified digital interface. For decades, displays relied on an analog interface, which has some benefits, but has become increasingly cumbersome in a digital world. The CE industry has largely migrated to the HDMI digital solution, with devices counting not if HDMI is supported, but how many HDMI ports are included on each device. Until recently, the telecommunications industry has not really needed much in the way of external interfaces, but now with cameras, video, e-mail access, etc., mobile phones seem to be migrating to some form of the HDMI standard. The PC industry, however, continues to flounder with a mishmash of analog and digital solutions. VGA, HDMI, and DisplayPort co-exist on many PCs, (along with a huge variety of dongles to connect one interface to another). The PC industry seems intent on making it difficult to interoperate with CE and telecommunications devices, to the detriment of consumers. As more and more CE and telecommunications companies start to compete in the PC space (watch the tablet space carefully), one of the predictable results is that traditional PC companies are going to find it increasingly difficult to compete simply because they make it so awkward to interoperate with CE and telecommunications devices. Traditional PC companies such as Dell and HP have tried and failed in the TV space and are not faring well in the mobile-phone space. As a result, traditional CE companies such as Sony and Samsung (and perhaps newly Apple), which are enabling interoperability across very broad product lines, are likely to really start encroaching into the PC space.
3. "Green." It is often noted that a company's declarations about "green" technologies and caretaking of our environment seem to be largely marketing tools rather than major development efforts. The point is becoming increasingly moot, as it seems clear that voluntary efforts to develop green products will be trumped by government mandate. There will undoubtedly be howling by many companies about such regulatory efforts (particularly when the efforts are not unified from country to country), but the smart companies will recognize that "green" is here to stay and that they will best benefit by turning their green marketing hype into product reality.
4. The politics of e-waste. A potent part of the green revolution has to do with the handling of e-waste. The practice of first-world countries exporting electronic waste to third-world countries will not be tolerated much longer. Smart companies will not only develop energy-efficient products made in environmentally friendly factories, but they will also strive to create ways to easily and profitably recycle and dispose of their older products. This, too, will be mandated, and delaying the inevitable will be a costly mistake.
5. Political interests will diminish display-related innovation. The recent U.S. Justice Department actions against numerous LCD manufacturers for price-fixing has certainly succeeded in improving the bank accounts of a good many attorneys and has supposedly benefited the American consumer in the form of some $900+ million in fines. The litigation has now spread to other jurisdictions – with numerous U.S. states, at least two class-action suits, and some suits by specific companies – all claiming damages from LCD manufacturers. Now the legislation has crossed the Atlantic to the EU, and it is expected that other courts around the world will also stake their claims. While price-fixing regulations are probably appropriate in order to protect the consumer from monopolistic pricing practices, the predictable consequence of substantial fines, enormous energies spent in courts, and the imprisonment of key executives in the display industry is that prices will increase and profit-ability will shift from innovation to litigation avoidance.
Third Dimension
Representing 3-D images on a 2-D surface is inherently problematic, often resulting in criticism of the results. But we live in a 3-D world, such that 3-D displays are inevitable as a primary viewing technology. Once relegated to niche markets (medical imaging, bio-science, CAD/CAM, system design, and petroleum exploration), 3-D displays are moving quickly into the cinema, home television, PCs, mobile phones, gaming systems, and really virtually all display-based systems. While there are specific applications that do not benefit from 3-D imaging, a 3-D mode will almost certainly be a feature that is offered on most devices within the next few years.
1. The 3-D invasion is unstoppable. Despite more than a little negative press highlighting some of the issues related to stereoscopic 3-D, both in the cinema and the home, it is mostly noise – akin to those who dismissed talking movies as never being able to find a significant position against silent movies, or to those who predicted that color TV would be short-lived due to the lack of color content. 3-D is coming, to most applications, and faster than even the most aggressive tend to imagine. And the improvements in both the science and the art of 3-D will be continuous and very impressive.
2. The "battle of the glasses" ignores the real issue. Considerable debate has recently ensued in the press about the competing technologies related to glasses for 3-D TV (passive polarized solutions vs. active shutter-glass solutions). Both camps make compelling arguments, but the reality of the situation is that as long as glasses continue to be required at all (which is likely to be for another 8–10 years or more), the debate about glasses needs to be restructured. The problem with glasses in the living room is that not all viewers can give their exclusive attention to the TV; when wearing glasses, the 3-D TV serves as a 3-D TV, but when the glasses come off, the viewer needs to see the 3-D TV in 2-D. The need is not for switchable 2-D to 3-D, but for simultaneous 2-D and 3-D (one with glasses, one without). The first solution to enable simultaneous 2-D and 3-D will win the battle of the glasses.
3. Poor-quality 3-D filmmaking will not kill 3-D cinema. A common theme from both dissenters and advocates of stereoscopic 3-D cinema is that poor production quality will killthe popularity of 3-D. Do not believe it! Recall from your youth the hours you spent watching a TV channel with absolutely horrible reception. Did such headache-creating, stomach-churning poor quality result in the demise of TV? Hardly – you actually learned to better appreciate good quality. And most of us have a fascination with the occasional roller-coaster ride, even if it might leave us a bit queasy. To deny the occasional pop-out effect because it creates an uncomfortable negative parallax is not necessarily the right thing to do.
4. Real-time holography. The famous sequence from Star Wars of Princess Leia standing in front of R2D2 in the form of a holographic video (although in violation of the laws of physics in this example) is still quite compelling to anyone thinking of 3-D. This sort of real-time video holography is not so far away, and it will be great fun to follow as the technology starts to emerge in the next couple of years.
5. 3-D is not just displays. 3-D technologies extend far beyond the world of displays, encompassing hardware and software developments that are continuously advancing the industry. Capture devices such as 3-D cameras, videocams, and scanners; interaction devices such as 3-D mice and haptic gloves; motion-sensing tools; and output devices such as stereo-lithographic printers, lenticular printers, and architectural and scientific renderings all combine to complement the growth of 3-D displays. The peripheral technologies for 2-D displays will all see enormous innovation as they increasingly emerge to support 3-D displays.
High Resolution
This author has been a champion of high-resolution displays for many years, and in fact has been completely wrong about the growth of high-resolution displays in the PC industry for the better part of a decade. That the PC industry seems stuck at the 100-ppi level is a marvel – when the benefits of increased productivity, improved performance, and overall enhanced communications effectiveness are so easily demonstrated at higher pixel densities. But 100 ppi is about to change – finally!
1. The iPhone 4 will inspire "Retina"-like displays in virtually all applications. Apple's iPhone 4 is a beautiful display, which at 326 ppi and cleverly dubbed the "Retina display," has convinced the general consumer that pixel density is a meaningful differentiator. Not only can we increasingly expect > 300-ppi pixel densities on mobile phones, we will soon be seeing >150-ppi pixel densities on the desktop and >100-ppi pixel densities in the living room.
2. Stereoscopic displays will demand higher-than-"Retina" performance. For us to effectively view the world in 3-D, we will need even more pixels. Adding depth to an image increases our demand for enhanced image quality.
3. HDTV is just the tip of the iceberg. It is been less than 3 years since the industry had serious debates suggesting that 720pwas entirely suitable; that 1080p was just a waste of pixels. You can still occasionally read commentaries about how Blu-ray adds little over DVDs. The "science" used to justify these claims seems sorely lacking because it is truly the rare individual that cannot discern enormous differences, even at considerable viewing distances, between devices with different pixel densities. And this differentiation has not yet come close to the point of diminishing returns – we will certainly see more and more quad-HD (3840 x 2160), and then UHD (7680 x 4320). As always, bandwidth will be an issue, but do not pay attention to the market "experts" who try to tell you that today's Blu-ray is perfectly adequate. It's not.
4. Color does not matter. OK, color does matter, but it is not a question of how many colors – it is the range of colors that can be displayed on a screen. A display that shows 1 trillion different colors is meaningless if all of them are a different shade of blue. Likewise, a display that covers "90% of the CIE curve" is meaningless if it skips one key color group. Since the human visual system cannot distinguish anywhere close to 1 billion colors, let alone 1 trillion colors, the industry's current focus on bit count needs to be displaced with a focus on extending the range of colors that are reliably depicted on a display.
5. Multicolor primary displays. RGB stripes within a square box have been a great way to create flat-panel displays to this point. Moving forward, there is little question that we will increasingly see multicolor primary displays that utilize a variety of subpixel structures. Things like RGBW, RGBY, the PenTile Matrix, and a broad array of novel pixel structures will increasingly enable performance differentiation and offer improvements to our visual experience.
Touch Panels
When we started the Touch Panel newsletter about 6 years ago, one well-known industry analyst suggested that we would have no subscribers and that the topic was simply too narrow and very "boring." "You just cannot make a resistive touch screen seem interesting to anyone but an engineer who has been told their job depends on creating a touch-based device that almost no one will want." We ignored this pundit, and today the Touch Panel newsletter is the most popular of all our newsletters.
1. Explosion of hybrid touch-technology offerings. One of the reasons that so many touch technologies are currently competing for a position in the market is because none of the existing technologies perfectly satisfies the needs of the application. As such, numerous developments are under way to combine more than one touch technology into a single solution – thereby broadening the usage model. For example, the popular projected-capacitive technology used in Apple's iPhone and iPad does not enable pen-input and does not function with gloved hands or if the surface is wet. Likewise, the traditional tablet PC requires a stylus and does not allow for finger input. Hybrid solutions that combine digitizers with projected-capacitive touch technologies to enable both pen and finger operability are becoming popular. Another example is the recent emergence of analog multi-touch resistive (AMR, also called hybrid analog-digital). Both are alternatives to projected-capacitive technology that utilize the familiar resistive technology. There also have been recent announcements related to hybrid voltage-sensing and charge-sensing in-cell touch technologies. It is quite predictable that in the absence of technology breakthroughs that satisfy all user needs, hybrid approaches will continue to be introduced to the market.
2. Haptic feedback. Studies indicate that the human sense of touch is enhanced significantly by both audio and force-feedback cues. Without such extra-sensory feedback, touching a glass-like surface is unappealing (which helps explain the appeal of the sounds we receive from a typewriter and the keystroke responses of a typical computer keyboard). Even the sound of a pencil on a sheet of paper provides feedback cues that are helpful to the user. Most touch technologies fail to provide these natural feedback cues – making it difficult to make many inputs that we are accustomed to making with our fingers or pen-based input devices. As such, it is very likely that the touch-screen market will increasingly include haptic feedback technologies. Such solutions have been demonstrated to improve both the user's experience and the efficiency of the touch technology. Haptics have clearly been demonstrated to speed up touch recognition, reduce user errors, improve safety in mission-critical applications, and increase touch confidence in distractive environments. Moreover, haptics can help reduce screen size in applications that demand small displays – by enabling a confirming feedback cue in a small space. There are several haptic technologies competing for a share of this growing market and there will be a bit of a battle to identify the best haptic solutions for the future.
3. Non-touch interactivity. The popularity of Nintendo's Wii has demonstrated a need for enhanced motion recognition and digital interaction with display devices. Both Sony (with its newly released Move) and Microsoft (with Kinect) have signaled a substantial response to the Wii – enabling much more sophisticated interactive capabilities. We will almost certainly see these sorts of gestural solutions gain favor in the home and the workplace – ultimately replacing the traditional remote control, and perhaps even making inroads into the mouse market.
4. Indirect touch solutions. The notion of "touch-screen" technology predisposes one to consider touch technologies that directly address the surface of the display. But there are many surfaces besides the front of the screen that can be utilized to manipulate data on the screen. Consider the back side of a smart phone. Rather than obscuring the images on the display with your fingers, the touch interaction could be easily shifted to the back surface of the phone – functioning to some extent like a mouse. Many of the issues associated with fingerprints, transmissivity, scratch resistance, etc., disappear when a different surface is used. Or consider the dashboard in an automobile, including sound-system controls, air controls, GPS, etc., all of which require some level of reaching out and touching a button or knob to adjust the settings. There is no reason that these distracting touch-based interactions cannot all take place on the steering column using indirect touch solutions. Such examples of indirect touch are likely to expand even faster than solutions in which the user directly touches the display surface.
5. Interaction with 3-D displays. Stereoscopic 3-D display technologies have recently gained mass-market attention, particularly in the TV space, but also in various PC announcements. One of the biggest challenges associated with 3-D displays is that most user-interface technologies (including touch screens) register in only x/y space. Manipulating images in 3-D space has not been developed in concert with the emergence of the 3-D display market. Although 3-D mice and camera-based solutions have been developed to recognize user inputs in 3-D space, the technology is still in its infancy. It is predictable that in the coming years, we will see more and more developments related to interacting in 3-D space – across all applications.
Summary
As a practical matter, it is impossible to consistently predict the future with any meaningful accuracy, even based on the rather broad generalizations highlighted in this article. Nevertheless, certainly some of these prognostications, and perhaps even most of them, will hit the target. One thing is for sure – in the world of displays, betting against the overall capabilities and demands of the human visual system is likely to be a bad bet. Whatever display is used today will be eclipsed in terms of performance by the display used tomorrow. •