In the past year, several major consumer-electronics companies have aggressively marketed 3DTVs and related equipment (such as 3D-enabled Blu-ray players), particularly in the United States. But despite aggressive marketing and a substantial amount of media hype, 3DTV sales have been very slow during the first half of 2010, and analysts now project that final 2010 sales will only reach about 4 million (a minuscule fraction of total projected TV sales). Although analysts project that 3DTV sales will increase substantially in the next several years, rising to 78.1 million by 2015, users may not necessarily view much 3D content on these sets, considering that the price premium for 3D capability is low and could become negligible. In fact, the additional manufacturing cost necessary to allow 3DTVs to interface with the active-shutter glasses that are necessary to view the 3D effect is very low, and nearly all high-end digital televisions already have the capability to display images at a sufficiently high frame rate to support 3D. It is very easy to imagine a future in which manufacturers eliminate the "3D-ready premium" and tens of millions of people buy 3DTVs without 3D capability's ever factoring into their purchase decisions. Many of these same purchasers, for whom 3D capability is an afterthought, will never go on to buy even a single pair of active-shutter glasses. Currently, such glasses cost $100 and up for a single pair, and cost-reduction opportunities are somewhat limited because of use of LCD lenses. Even if the average selling price of shutter glasses falls to, say, $25 as a result of volume production, households with children—which may be the best potential market for 3D content—may resist buying multiple pairs of eyewear. Accordingly, even if analysts' 3DTV sales projections prove accurate, 3DTV might still end up being effectively a market failure.

Even so, the potentially lackluster future for 3DTV may not spell doom for 3D-display technology in the home. Single-user, eyewear-free 3D technology promises to become cost reduced fairly rapidly with the emergence of autostereoscopic personal devices. Manufacturers are targeting emerging small-scale 3D displays toward cell phones, portable gaming systems, and other portable electronics. Such displays can offer a combination of low cost and high performance, and, critically, can produce convincing 3D effects without requiring the viewer to wear any special eyewear. Personal devices and energy appliances alike strongly tend to be for one user at a time, and the user typically views those devices' screens from a predictable distance. The current generation of small 3-D screens appears to be well suited for such personal interfaces. Such displays could find use in handheld remote controls, dedicated home-automation control surfaces, energy appliances such as smart thermostats, home-security consoles, digital photo frames, and other human-machine interfaces. As a result, developers face opportunities to design user interfaces that could be unique and compelling and could enhance the value proposition for a wide range of connected-home technologies.

For example, small 3D screens could work very well in personal information displays (PIDs) like the popular Chumby. PIDs' widget-based interfaces could benefit from the illusion of depth that 3D technology could provide, allowing programmers to create widgets that convincingly resemble physical objects. Similarly, 3D screens could make home energy monitors more compelling to view and easier to read at a glance. Many home energy monitors are to be decorative as well as functional, and 3D displays allow designers far more freedom to create decorative effects than do 2D displays. The extent to which digital displays can seamlessly fit into a home's décor can be critical to many users' purchasing decisions for a wide range of devices besides home energy monitors. For example, wall-mounted information, communication, and home-control displays might become far more appealing for many potential users if the devices' 3D displays allow them to "disappear" into the décor when not in active use (for example, serving as a mirror) or when providing ambient information displays that complement modern interior designs.

Early signals indicate that autostereoscopic 3D displays for portable devices have a high chance of market success in the near term, which means that economies of scale for such displays should quickly develop that will make the displays feasible for inclusion in home-automation, energy-management, and related devices. An important early signal of success is Nintendo's (Kyoto, Japan) using Sharp's (Tokyo, Japan) autostereoscopic 3D display in Nintendo's upcoming 3DS portable video-game system, which the company debuted at the 2010 Electronic Entertainment Expo (E3; Las Vegas, Nevada). Many hundreds of E3 attendees were able to test the device, typically after waiting many hours in lines that snaked around the E3's enormous exhibition hall. Reportedly, the 3DS 3D display capabilities worked extremely well, producing a convincing sense of depth that positively affected game play in subtle but important ways. For example, one reviewer commented that the 3D effect significantly improved his ability to position objects within a game's virtual space. Nintendo has been extremely successful in the portable gaming market; its current handheld platform, the Nintendo DS, has sold over 130 million units since its 2004 debut, and its previous handheld platforms (the Gameboy Advance and the Gameboy) sold over 80 million and 125 million units, respectively. Given the company's track record and the very positive initial response to the 3DS, the platform will likely become another sales success upon its release and will almost certainly inspire other portable device makers (including cell-phone makers) to add autostereoscopic 3D displays to their platforms.

Some companies are already actively pursuing autostereoscopic 3D displays for cell phones; for example, cellular carrier NTT DoCoMo (Tokyo, Japan) recently demonstrated a prototype autostereoscopic display that the company plans to incorporate into smartphone models within the next several years. The NTT DoCoMo unit uses a lenticular array to produce 3D display effects that are visible from eight viewing angles. Lenticular arrays already find use in some portable electronic-device screens; for example, Fujifilm's (Tokyo, Japan) 3D point-and-shoot digital camera uses such a display. The 3DS uses a different display technology—parallax barrier—that is currently most common in automobiles (where the technology does not create a 3D effect but instead allows a single center-mounted screen to display a different image to a driver and a passenger). Although neither lenticular lenses nor parallax barriers require a user to wear special glasses to enjoy the 3D effect, they both suffer from significant disadvantages. Parallax-barrier technology transmits light through small vertical slits, dimming the overall display significantly. Lenticular arrays transmit light through fixed microlenses, allowing for more light transmission at the expense of versatility. Both types of autostereoscopic displays can render ordinary 2D images, but lenticular arrays tend to present poor resolution in 2D mode. Both display technologies also have very limited angles within which a viewer can experience a 3D effect because they both rely on transmitting a distinct image to each eye. If a viewer moves too far out of alignment, the effect fails, and the display looks blurry. It is possible to improve viewing angles through using multiple redundant sets of parallax barriers or greater numbers of lenses in an array, each of which is tuned to a different viewing angle. But doing so quickly increases the overall display's resolution requirements (or it greatly decreases the resolution of the resulting images). On cell-phone-scale and other relatively small personal displays, the increased resolution requirement is relatively low, because even at low resolutions, small displays tend to appear sharp. For example, NTT DoCoMo's lenticular display supports eight simultaneous viewing angles with a 1024-x-768 screen; the final effective resolution for each viewing angle is comparable to that of an average cell-phone screen. For larger screens (such as TV-scale displays), the effective resolution needs to be much higher to deliver the level of image detail that audiences consider to be normal. As a result, the display's physical resolution must be very high, greatly increasing cost to the point at which serving a mass market is not feasible absent a generational leap in technology. Conversely, 3- to 4-inch displays already reach or exceed the resolution necessary to support one or a few autostereoscopic 3D viewing angles while remaining cheap enough to integrate into a range of home display devices.