As the world waits with bated breath for an Apple tablet, one thing is for certain: the rumored tablet with a 10-inch touchscreen won't be cheap. \n\nMost new-fangled Apple products cost the proverbial arm and leg, and it's unlikely an Apple tablet (which the blogosphere calls the iSlate) will break this \n\ntrend.One of the more sensible arguments about the price of an Apple tablet comes from NextWindow, which makes touchscreens for PC makers like \n\nDell, Hewlett-Packard and Sony. An Apple tablet will be on the high-end in price, NextWindow executives say \u2014 not because of Apple's \n\npropensity to jack up prices, rather a 10-inch touchscreen is going to be expensive to deliver.[ Check out five moves Apple should make this year, reports CIO.com. | Mobclix predicts a wild decade for mobile. ]It's a pretty good bet that an Apple tablet is just around the corner. Sources told the Wall Street Journal's AllThingsD reporters that Apple plans to \n\nannounce "a major new product on January 27." And that the likely price point is under $1000. If \n\nApple holds true to form, that will mean $999. Apple, of course, is fully aware of the tablet rumors but as of yet has done little to quell them. It would be a \n\nmajor disappointment if Apple's major new product turned out not to be a tablet.How much would you pay for an Apple tablet? A Barclays report last week predicts Apple will sell at least a million tablets per year and that the tablet has the potential to be one of the major Mac \n\nlines over time. But Manish Rathi, co-founder of Retrevo, a consumer electronics shopping site, says the tablet would need to hit the $600 price point to \n\nbe really successful.This price point would convince a good number of PC users to jump to an Apple product, according to findings from a recent Retrevo survey. "If the \n\ntablet can get to something like the iPhone, then shipments go over the top, which means you have to go beyond your Mac loyalists and get to the PC \n\nusers \u2014 the people who are willing to switch."Meanwhile, Freescale Semiconductor just showcased reference designs of a tablet with a 7-inch touchscreen set to hit the market later this year. The cost: $200.But Apple won't be able to get anywhere near that and will be lucky to get to the $600 price point, according to NextWindow executives. \n\nNextWindow does not make the particular touchscreens that Apple uses today.NextWindow CEO Al Monro and product marketing manager Geoff Walker, who has been involved with mobile computing and touchscreen \n\ntechnology for two decades, told CIO.com about the challenges Apple faces when moving from the 3.5-inch touchscreen of the iPhone to a 10-inch \n\ntouchscreen of an iSlate. They also share some insight on where touchscreens are headed next.NextWindow CEO Al MonroNextWindow Product Market Manager Geoff Walker \n\n\nWhat size touchscreens do you make?\nMonro: The touchscreen size for the desktop is predominately 18.5 to 24-inch. In the large format, increasingly most of our stuff is over 65-inch \n\nfor education \u2014 an interactive whiteboard. \n\nWhat's the technology used in the small iPhone screen?\nWalker: The technology that's in the iPhone is called projected capacitive, or Pro Cap. Prior to the iPhone, the worldwide market for Pro Cap \n\nwas about $20 million. This year it'll be somewhere around a half a billion mainly due to the influence of the iPhone. Now almost all of the mobile phones \n\nhave at least one Pro Cap touchscreen in their product lines. \n\nIn layman's terms, how does the technology work?\nWalker: Projected capacitive is made from an X-Y grid of transparent conductors. Imagine a bunch of horizontal and vertical lines, say, 20 by \n\n15. Every place those lines cross is a potential touch point. The controller measures the capacitance between those two conductors, which is a very tiny \n\nnumber. When you put your finger on [a touch point], your body has a lot of capacity to ground because of the water in your body. So you change the \n\ncapacitance between those two transparent conductors. The controller continuously measures the change in the capacitance between every intersection. \n\nOn the [3.5 diagonal inch] iPhone screen, there may be 200 to 300 intersections that the controller is scanning. When you're dealing with such a \n\nscreen, the length of the connections to the touchscreen are quite short. The actual transparent conductor in the screen itself is pretty small.\n\nWhat are the challenges with scaling it up?\nWalker: As you scale it up to 10 or 12 inches, the lines and connections get longer and they become more sensitive to noise. The absolute \n\nlargest [Pro Cap] touchscreen on the market today is 19 inches. It gets really difficult to measure the tiny changes in the capacitors at a distance. If you're \n\nin the middle of the screen, there's a long connection between you and the controller. That problem of trying to measure the very small change in the capacitance as the wires get longer and longer really makes Pro Cap stop at about 24 \n\ninches \u2014 and that's really pushing it. Where you tend to the notice the difference is around the edges. If you're drawing a line with your finger, at \n\nthe edges you might have a jagged line. As the screen gets bigger, the transparent conductors pick up more noise. At some point, you can't tell the change in the capacitance from the noise. \nBut a 10-inch Pro Cap touchscreen is still doable.Walker: The touchscreen in the iPhone today costs about $3 per diagonal inch. As you go to the netbook size with, say, a 10-inch \n\ntouchscreen, it goes to $4 per diagonal inch. For a 19-inch desktop, it's $5 per diagonal inch. The current market price for the iPhone [touchscreen] is \n\n$10 or $11, while a 10-inch touchscreen [for a tablet] will be about $40. That's getting pretty expensive.\n\nCan Apple use a different, cheaper touchscreen technology?\nWalker: At this point, Apple would need something that was multi-touch because they've set the standard with the iPhone. In the laptop space, \n\nthere's really very little [vendors] that do multi-touch other than Pro Cap. Also, on the iPhone, two-finger touches are reasonable. But on a larger 10-inch screen it's possible that Apple will want to support more touches. \n\nThis means a more complex controller. That may mean \u2014 and I'm speculating here \u2014 that an application would have to ask the OS how \n\nmany touches you support and then adjust itself accordingly.\n\nNextWindow makes big touchscreens. Can you make smaller ones?\nWalker: Our touchscreens work by the fingers causing a shadow in the light source that is distributed around the edge of the screen. It's a \n\ncompletely different technology. One of the key advantages of our technology is that it scales up very nicely. You still have the two same optical sensors. \n\nAll you do is expand the size of the reflector that goes around the edge. To go from a 30-inch touchscreen to a 50-inch screen is very little in cost.For us to [make smaller touchscreens], it's technically possible but economically not that good. Our optical sensors take a fixed amount of space. On \n\na 22-inch screen, it's insignificant. On a 10-inch screen, it's significant. And on a 5-inch screen, it's too much. Monro: There's no perfect touchscreen. And there's not just these two technologies, either. They all have their strengths and weaknesses. \n\nThe other thing that makes the [Pro Cap] technology ideal for the iPhone is that it only triggers with the finger. If it's in your pocket, it doesn't get \n\ninadvertent touches. Walker: That also means you can't use a stylus \u2014 it's easier to write with a stylus than a finger, and Pro Cap is finger only.\n\nWhere is touchscreen technology headed?\nMonro: There's a lot of research being done, and the iPhone has triggered it. We're looking at it more broadly, not just touch but user \n\nexperience. We're being challenged by our customers to think beyond just touch and towards gestures, maybe integrating touch with other features and \n\nfunctionalities on your PC such as the webcam.Tom Kaneshige is a senior writer for CIO.com in Silicon Valley. Send him an email at email@example.com. Or follow him on Twitter @kaneshige. Follow everything from CIO.com on Twitter @CIOonline.