When most folks hear the words “virtual reality”, they have visions of wearing a headpiece with goggles that transports them, figuratively, to other worlds, dimensions, or desirable realities. Or they recollect the revered “holodeck” from one of the endless variations of the Star Trek commodity, a holographic chamber that would recreate scenes and situations of one’s choosing and then allow one to physically participate.
Virtual reality headgear with goggles
Star Trek holodeck
Few would equate the aforementioned common visions of virtual reality with a cell or smart phone. However, Infineon Technologies AG and pmdtechnologies gmbh have developed 3D image sensor ICs they claim will in fact bring virtual reality to mobile devices. But don’t expect to be having any full- or outer-body experiences normally associated with virtual reality.
According to the companies, future mobile devices using the 3D image sensor chips will be able to realistically detect their surroundings in three dimensions. Dubbed the REAL3 family, the chips promise extremely realistic virtual and augmented reality game experiences that involve the interaction of the gamer’s own hands and his living environment within the game via head-mounted devices. Besides games, other applications will include the spatial measurement of rooms and objects, indoor navigation, and special photo effects.
Three REAL3 3D image sensor chips, capable of delivering 19,000, 38,000, and 100,000 pixels
integrate microlenses. They each differ in resolution: the IRS1125C works with 352 x 288 pixels, the IRS1645C with 224 x 172 pixels, and the IRS1615C with 160 x 120 pixels. In this respect, the IRS1645C and IRS1615C are produced on half the chip area of the IRS1125C.
REAL3 3D image sensor chips
The IRS1645C is suitable for use in mobile devices. Infineon and pmdtechnologies are joint partners in Google’s Project Tango. With Tango, cell phones and tablets are equipped with a special optical sensor system for 3D perception, which includes a 3D camera with Infineon’s IRS1645C 3D image sensor chip. Applications are augmented reality, indoor navigation, and three-dimensional measurement.
The complete 3D camera for Google Tango consists of the IRS1645C and an active infrared laser illumination, residing in approximately 10 mm x 20 mm worth of space. With a range up to 4m (13 ft.), a measuring accuracy of 1% of the distance and a frame rate of 5 fps, the 3D camera subsystem consumes less than 300 mW in active mode.
The 3D image sensor chips operate with infrared light and use the time-of-flight measuring principle, meaning for each pixel, the image sensor measures the time the infrared light takes to travel from the camera to the object and back again. Simultaneously, each pixel also detects the brightness value of the objects.
Apparently, the focus here is more on 3D perception and presentation. Although 3D, or even 4D, is an integral part of the virtual reality experience, a 3D visual event is not totally one of virtual reality. Of course, this depends on one’s definition of “virtual reality”. According to Wikipedia, “Virtual reality or virtual realities (VR), which can be referred to as immersive multimedia or computer-simulated reality, replicates an environment that simulates a physical presence in places in the real world or an imagined world, allowing the user to interact in that world. Virtual realities artificially create sensory experiences, which can include sight, hearing, touch, and smell.”
Somehow, being able to play games in 3D on a smartphone, though a highly impressive achievement, does not quite fit the definition of a virtual reality experience. Perhaps we need a truly operational definition. ~MD
Further technical information on the Infineon 3D image sensor chips is available at http://www.infineon.com/3d-imaging
Information about prototype cameras and the pmd technology is available at http://www.pmdtec.com