What determines TV Sizes

LCDs are made, several at a time on larger sheets of glass (called a mother-glass) and “cookie cut” into smaller displays. Determining how many LCDs to cut from a mother-glass is a balance of pricing and geometry. In general, larger displays sell for more per square inch than smaller displays, so there is an incentive to make as few cuts as possible. However with current quality requirements, the bigger the display, the lower the yield, as it is more likely to contain a visual defect. Further, for whatever size is chosen, the manufacturer must have orders for that size. In general, sizes are chosen so that at least 6 individual displays (cuts) come from each mother-glass but usually less than 25. An LCD maker with a yield issue may choose to do more.

There are a number of geometric considerations as well. Of course the size of the manufacturer’s equipment is a starting point, the length and width of the mother-glass it was designed to take. LCD fabrication equipment (fabs) comes in generations or gens. Early on, the gen of a fab did describe when it was made. However as the size of LCDs diversified with the types of products using flat panels, gen has taken on a meaning more related to the size of the equipment than when it was produced. An LCD maker may install a Gen 6 fab to make monitors and the fab may be newer than their Gen 8 fab making TVs. Within a Gen, sizes may vary somewhat; a slightly large Gen 6 fab may be termed a Gen 6.5. As with all manufacturing equipment, products change, screen sizes change, and a fab will eventually be making a different product in a different size from what it was originally designed for.

Aspect ratio is another consideration. TVs are generally 16:9. Notebooks may be 16:9 or 16:10. Cell phones and monitors can have substantial variances from square to 21:9. In addition to the display itself, a small border area is needed to cut the mother-glass into individual displays. The size of this border depends on the manufacturer. Finally, LCDs are usually made with all the displays on one mother-glass being the same type. The arrangement of these displays on the mother-glass is termed the lay-up. The layup does not necessarily use every square inch of glass, in fact usually not. However, makers like to maximize glass utilization from the standpoint of getting the most out of their equipment and maximizing the number of cuts.

Sometimes very small differences in equipment or display size can mean the difference between getting an extra cut or two. For instance, when the Standard Panels Working Group (SPWG) settled on a business notebook size of 16:10, 14.1” diagonal vs. the competing 15:9 14.0”, two sizes that cannot be differentiated except by actually measuring them, there were substantial manufacturing implications. While all of the fabs that could make a 14.1” could make the 14.0” as well, two of the fabs that could make a 14.0” could not make the 14.1” without making it with fewer cuts. This meant that those fabs were uneconomic at that size. The 14.1” size was chosen to be consistent with previous aspect ratios and with the long term planning for Windows regarding screen content.

So, very small differences in equipment size may cause an LCD maker to choose one particular screen size vs. another. This is why TVs are often termed 42” (or some other size) class vs having every maker make a screen that is precisely 42”. Sometimes when it seems that the industry has settled on a standard size such as 40”, an individual LCD maker will determine that he can get the same number of cuts and consequently virtually identical costs, on a 42” or larger screen size and start offering that size. Even when the industry seems to standardize on sizes (32”, 40”, 55”) other sizes will proliferate. For a particular sized fab originally designed to make 12 cuts from a mother-glass, only certain sizes of larger screens will fit well on that equipment. In this example, trying to make a slightly larger screen may mean going from 6 cuts to 3.

Recently there was a story of some TV brands selling smaller than advertised TVs. The article tended to blame the retailers for the problem. However, large retailers sell multiple brands and multiple models; they cannot inspect every TV model to ensure that it is in compliance. Most Retailers actually do keep tape measures behind their TV counters; however this is mostly to ensure that the TV physically fits where the consumer is intending to place it. Short of actually measuring the screen diagonal yourself, the best guarantee that you are getting the screen size advertised is to buy a trusted name brand.

The New IBM

When DisplayWriter, by IBM, was still the dominant word processing software, my company was faced with a decision on upgrading. I don't recall what decision was made, but I do recall that it wasn't DisplayWriter. DisplayWriter was ruled out because it could not write to an Ascii file which was the universal word processing file type at the time. It could read Ascii, it just couldn't output to Ascii, meaning that once you modified a report in DisplayWriter, future modifications had to be done with Displaywriter. Rather than cementing the IBM software as the only choice, the Ascii situation cemented Displaywriter as a definitely not. Personal tech decisions can be less pragmatic. However, repeated instances of not putting the consumer first can wear on a company's brand and, eventually, marketshare.

In Europe, cell phones are required to have a micro-USB connector. In addition to convenience for the customer, this minimizes waste from having to continually buy multiple new chargers and discard the old. Preserving connections such as preserving connections to other types of word processing software minimizes the headaches and expenses of upgrading system components without having to upgrade everything. In some sense, this is more important to the consumer as no one wants to toss all of their old peripherals in order to upgrade particularly if their peripheral is an automobile with a dock made for the old device with the old connector. I imagine the automakers are not pleased with the idea of a new connector either as they had been considering closer integration of car functions with the owners mobile device.

In Rugged Displays I mention how, although consumer cared about every bit of weight, they held little value for increasingly thinner notebooks once they got under an inch. We also now know that 80-90% of cell phone users jacket their phones, sometimes increasing the thickness by triple. As with many factors in consumer design, thinness can be pushed to the point of diminishing returns or even no value beyond bragging rights. To be sure, bragging rights are important for branding but they are easily trumped by features that carry real benefit.

The Film Rolls No More

When the IBM PC was introduced in the early 1980's the component cost of the 5 1/4" floppy drive was about $550. After some initial rapid cost reductions and a format change (with a capacity increase) around 1987, the device settled into a very regular 18% per year cost reduction. Although there were some attempts to expand the device capacity at the end of its life, the floppy basically relied on predictable annual cost reductions to remain on the PC platform. The image to the side is from an old technical paper of mine on integrated optics. Being partly a mechanical device and flash being made by photolithograpy, it was a matter of time before flash replaced the floppy; but floppies did not live that long and flash thumb drives are now used like floppies were although I am still waiting for AOL to start sending me dozens of free thumb drives in the mail. (Before net connections were standard, AOL used to send out its net connection software on floppy disk to anyone that they remotely thought might have a computer.)

Floppies were cheap enough to be considered free but lacked the capacity of a hard drive or tape. However, like tape, it was removable from the device and made for easy transfer of data from one machine to another. But therein lies the rub. Removable media are more a form of communications than they are of storage. Though the floppy was, in some ways competing with tape or a hard drive, the real competition was the internet. As files grew bigger and the internet grew more capable there was no longer any point to having a floppy disk. About the same time floppies were going away, optical discs (with a c) were on the rise. Optical discs were cheaper and much higher capacity. However, advancement of the internet and of wireless capacity has been relentless. Even the cheapest DVDs and Blu Rays today come with a WiFi connection standard and increasingly rarely get used to actually play discs.

Tape has disappeared as well. Hard drives were on a steeper cost curve and tapes inability to do random access did it in. AS on the PC platform, Tape's optical cousin, film, survived for much longer having inherently much higher data capacity. However,Fuji is now discontinuing its motion picture film business, shortly after Kodak announced its exit from the business as well. Although the decision may be credited to a general trend to have everything digital, end to end, it is really the low cost of digital transport rather than any cost advantage of digital storage. It was the combination of cheap hard drive storage and vanishingly small data delivery (as opposed to carting around 100 pound rolls of film) that spelled the end for film at the movie theater.

Film, of course, is not disappearing completely. Very high end theatrical projection such as Imax will continue as film is still top end as a theatrical display technology rather than as a communications or storage device. I earlier published a list of my favorite display related movies. There were only 9 in my top ten. Cinema Paradiso is my #10. Here's to film.

Fine

Brick and Mortar gets a Boost

Three recent stories give some solace for the brick and mortar (B&M) retailers: Showrooming Debunked By Sales Data: CEA, Sun Sets on Endless E-Commerce Summer as Sales Tax Comes to Amazon, LG Switching To A “One Price” On-Line Policy for HDTV, Blu-ray Players and More. The CEA data is a bit suspect as the internal figures given in the story don't reconcile. However, assuming that the CEA has it reasonably accurate, showrooming is not as big of a problem as was suspected, and the playing field between B&Ms and on-line has shifted in the B&Ms favor.