RPTV RIP

The headline is, “Mitsubishi Drops DLP Displays: Goodbye RPTVs Forever”. Like 3D, projection TV got off to a bad start. The first widely available projection TV was the Kloss Videobeam (Henry Kloss was the K in KLH). It was based on a single color CRT (driven very hard) and projected on a specialty curved screen. The product had a number of difficulties. Being front projection, it had to be viewed in the dark. Even so it was dim. The curved screen had multiple problems as well. It could not be cleaned with conventional cleaners without leaving a lasting residual in the image on the screen… and it was added expense.

One by one, these problems all were fixed; but not by Kloss as they were immediately displaced from the market by the Japanese with a 3 tube projector design. Due to the loss of energy and light caused by the shadow mask in a color tube, a monochrome tube can be 5 times as bright as a color tube. Having three monochrome tubes (a red, green and blue) in a projection set made for an image that was 15 times brighter. Improved optics did away with the curved screen and switching from a front projection to a rear projection format meant that it could be viewed in a lit room; RPTV was born.

These improvements eliminated the initial problems with projection TV but created new ones as well. Early RPTVs were difficult to align and the sets in consumers’ homes were frequently not aligned. Also the lenticular front screens did a great job of spreading out the light from left to right but had little effect distributing light vertically. Many projection sets were used as public displays in bars and placed up high where the primary light from the display went over the heads of the viewers. The result was in your neighbor’s house and in public, when you saw an RPTV, it usually looked terrible. One other aspect remained as well, driving a CRT very hard meant that it necessarily had a short life span, significantly shorter than consumers were used to.

By the mid 1990’s, after 20 years of fine tuning, projection TVs had gotten to the point where consumers did have a hard time telling them from direct view CRTs. In consumer surveys taken at the time, many consumers reported buying 45” and 55” direct view sets even though direct view was never sold in these sizes; they were obviously projection sets. In addition to improving the screen and making alignment much easier, RPTV makers had incorporated clever folded optical paths, decreasing the RPT set thicknesses from feet to inches. Further, as HDTV with the transition to 16:9 was in the offing, RPTV looked forward to a bright future as CRTs were fundamentally ill-suited for the wider format.

Also beginning in the 90’s, new RPTV image engines were being developed. Most famously, TI developed the DLP, a micro-mirror technology using an external light source. Also Liquid Crystal on Silicon (LCOS) showed promise. The first DLP sets were expensive, and in-part to hold down costs, it was designed as a field sequential color set with a color wheel, as were the first color TV set designs from CBS. Of course, introducing a mechanical component into what had been a purely solid state device meant that these sets had maintenance issues. As with the original Kloss Videobeam, these single imager designs were rapidly dropped for 3 imagers. However even the improved design had maintenance issues as well as the high performance light source tended to have a life of only 2-3 years. This meant that the set still had to be actively maintained. Though makers took to packaging an extra bulb in the sets that they shipped, Consumers were frequently not aware of this and had to spend $200 to replace their bulbs the first time they burned out. Even so, replacing the bulb could be tricky as oils from your hand could cause early failure of the bulbs and even when the first bulb was used and installed correctly, the owner was still faced with making significant purchase every few years to maintain their set.

In spite of all of these issues, RPTV sales grew as they were actually a great value compared with large sized Plasma at the time. However, as Plasma got cheaper and LCDs grew in size and capability, RPTVs value story diminished. The loss of value was exacerbated by, in my opinion, a failure to tell a good marketing story to consumers. TI made some direct efforts to promote DLP but their commercials were ineffective and lacked a clear message to the consumer about why RPTV sets were better for them. Even today, with the HDTV transition having well passed, the average size LCD set being sold is only about 38”, much smaller than what is needed to fully take advantage of HDTV resolution. There have been significant pushes by the set industry as a whole on each new feature, frequently this in opposition to getting the consumer the proper sized set. Though both LCD and Plasma offer very thin sets, thinner than what can be made in RPTV, most American homes are not at a loss for space. American consumers really need to have larger sets and telling them this should have been the mission of the RPTV industry.

Mitsubishi positioned itself as “the large screen TV Company” and was the last maker of RPTV. However, lacking the marketshare and marketing dollars to make an impact, it was only a matter of time. The RPTV story has several lessons for other technologies as well. Being introduced with obvious visual problems, it took a couple of decades for the technology to shake off its initial bad impression. Plasma still suffers from a perception of image burn-in. Some of the initial 3D sets had bad flicker issues.

Most RPTV sales were in the US; in the beginning, virtually all RPTV sales were in the US. Though I sometimes criticize pyrrhic marketshare battles, there is significant value to a technology having a global appeal. Though the US is unique in being both wealthy and having large homes, the public information display/digital signage market is global. Significant numbers of RPTVs were bought here as public information displays, maybe as much as half in its early years. The set makers, in general never recognized this as a significant market until recently but the market has always been there. If RPTV had built some momentum in the early years it could have been doing fine in digital signage as well. But of course, in the US with the ADA requirement of nothing sticking out from the wall by more than 4” any RPTV installation has to be either high up or floor standing both of which are not particularly well suited to a retail environment.

How RCA Lost the LCD

From the IEEE Spectrum article, "Today, companies in Japan, South Korea, and Taiwan dominate the LCD industry. Meanwhile, the corporation that started it all has faded from memory, purchased by General Electric in 1986. Nevertheless, RCA’s technological legacy can be seen in every LCD wristwatch, calculator, laptop, and television. All of these screens trace their origins to that firm’s laboratories and factories. As much as they are portals to the digital future, liquid crystal displays are also reminders of a past filled with possibilities for the once-dominant American electronics industry. And in their story are lessons for any technology company willing to learn them."

Masahiro Kadomatsu, the former chairman of Asahi Glass used to remark about how US scientists could be so inventive while US management could be so awful, particularly being short sighted. At one point in time, Kodak was the world's sole source for liquid crystal, Corning's sunglases plant in Harrodsburg, KY was the sole source of LCD substrate glass. RCA developed the liquid crystal chemistry as well as switching mechanisms such as IPS and Westinghouse, invented the active matrix driving technique. Of these 4, only Corning retains a place in the LCD manufacturing supply chain. For the others, particularly for RCA, bad results from management decisions overwhelmed great technology coming out of their labs. There was a period of at least 50 years when every new major consumer technology went through a period where it only existed at RCA's Sarnoff Labs, now Sarnoff is no more. For a more complete history of LCD development see "Liquid Gold: The story of Liquid Crystal Displays and the Development of an Industry", there is an Amazon link to the book in the Recommended section on the sidebar. The book was written by Joe Castellano, a former RCA researcher and the inventor of IPS.

Batteries

Batteries are something of a conundrum. On the one hand, there is the continuing need for better batteries in mobile devices, longer last, storing more energy in a smaller space and with reduced weight. On the other hand, batteries can sometimes fail catastrophically. The higher the energy density (the more energy stored per gram or per unit volume) the greater the consequences of a catastrophic failure. In fact a bomb can be considered something of a battery, lots of energy stored in a compact space. Though the reaction that releases the energy is not reversible and it is hard, though not theoretically impossible to power a car with gunpowder (per Huygens), it is an efficient energy storage device. Today's batteries are less efficient but still share some properties with explosives, especially when they fail. With rechargeable batteries, dependent on a reversible chemical reaction, there is always the possibility that physical structures embodied in the two chemistries (anode and cathode)will bridge, resulting in a short. They can generate high temperatures, melting themselves, melting the device they are in, and potentially starting fires. This is a rare event, but, again, major increases in energy density would make a catastrophic battery failure much more consequential.

Of course, aside from better batteries, the best way to deal with battery life is to lower the energy drain. As the most energy intensive part of most mobile devices, the primary focus has been on the display and display related subsystems. Monumental progress has been made here and further progress continues to come. A second path has been to remove the mechanical components from the device, specifically the optical drive. Spinning up the drive, takes substantial energy. Further, as removable storage is more a form of communication, simply relying on the internet rather than a disc makes sense along several factors.

Battery improvements and reductions in power drain can carry battery life only so far. Most likely, in the future, there will be more ubiquitous application of wireless battery charging. However, wireless battery charging only gets rid of the power connector, not the need to access a wired power source. The original "One Laptop per Child" design had a hand crank to generate power as a wired source for the intended user set might be unavailable not just inconvenient. Of course, cars used to be hand cranked to get them started and watches had to be wound. There is another watch technology that might be relevant as well, energy harvesting. Self winding watches are less popular, as watch batteries have gotten better, but it is still viable. With improvements in micro-machining and 3D printing, energy harvesters can be mad very small and durable, I would think just the thing for a mobile device. As with better sunlight viewability, I expect someone will at least try marketing a device more adapted to actual usage models. Perhaps energy harvesting will not show up until the mobile market fully turns its attention to wearable computing.

More is Better

Today's lead article in VentureBeat discusses the new iPad Mini. Though the term "display" is used 5 times in the article, extolling the importance of the display, the lead-in photo (shown here) shows just how challenging it is using a mobile device outdoors. As seen in the photo, the contrast could not be much more than 10 to 1. In "Wither Pixel Qi" I discuss my surprise that the mobile industry does not move toward displays with better outdoor visibility. Though generating good color in an outdoor display is something of a challenge, there are alternatives to a standard LCD that provide trade-offs that might be more appropriate for a mobile device.

The author also goes on to give a generic definition of a "retina display","...instead of the lush Retina Display resolutions of 2048 by 1536, we get the same 1024 by 768 resolution we were so happy to run away from two years ago. (Since the iPad Mini’s screen is smaller, its resolution still looks sharper than on previous iPads.) It is described as a pixel format rather than a pixel density (pixels per inch) or a brand name. In, "Your existing HDTV is already a true 'Retina Display' ” in August's High Resolution Raymond Soneira explains the human factors of the pixel density perspective on classifying displays. In describing how the display "looks sharper than previous iPads" the VentureBeat author also makes reference to the human factors but at the same time ascribes the 2048 x 1536 resolution as "lush" apparently independent of screen size or pixel density.

As display professionals, we know, that especially in small displays, more pixels = less aperture which equals a dimmer screen. The challenged performance of the screen in daylight, as seen in the image would be that much worse with a "retina display" per the author's terms. However, in the minds of many, more is always better even when their eye's tell them such is not the case.

In "Trinitron, Retina, & What do you call an Apple TV" I compare the Trinitron name with the marketing mojo in "retina display". In a large sense, Trintron had an advantage in that most consumers had no idea what a Trintron was, only that it was better. Others could introduce sets using the trinitron technology (such as Mitsubishi's Diamondtron); however, because they could not use the Trintron trade name, Sony was in an unassailable position. If consumers have a specific idea what "retina" means, a specific number, then it is a small matter to equal or even out-do "retina" with a "more is better" spec.

Even better, someone can fix or improve the daylight performance. As I have related before, in TV set marketing, frequently the industry will focus on a specific spec, pushing it to performance levels beyond human comprehension.... until someone steps out of line and starts pushing a different spec. Brightness wars, were followed by contrast wars until the CRT industry settled on Black level. In the mobile wars, fixing the resolution issue was an obvious first step to enabling smartphones as a platform. Now that the issue is fixed, I expect that the device makers will move on. If more is better, how about some more outdoor contrast.