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DESIGN & PRODUCTS OPTOELECTRONICS herent combination of ccd and cMOs features temporal resolution required to tackle the received are combined with a best in class detector per- signal is in the sub-nanosecond range (50ps or formance in the near Ir range. advanced, cost less). at the same time, there is an ambient light efficient packaging technologies are another overlay at several orders of magnitude higher than crucial feature to pave the road to a large field the modulated illumination. Without very powerful of applications. however, the business case still charge separation and charge handling engines, needs to be made. the depth resolution will be way beyond practi- Market shares of ccd based imagers are cal values or completely masked by the ambient crumbling. an interesting but not necessarily Fig. 4: 3D ToF camera-on-chip light signal, or both. Furthermore, the size, the relevant question is how these markets would power consumption and the cost of available have developed if there had not been such a clear separation cameras are still in a range that inhibits commercial use in larger between the two technologies. and when looking at the market volumes. the toF imagers from epc solve these problems. the figures cited in the first section, one needs to be careful to put pixel performance in terms of signal quality is superb in any re- these figures in the right context. There are still application spect. and a highly integrated soc approach results in camera- segments that heavily rely on ccd based devices such as line on-chip devices that are well compatible with the functionality scanners and high performance tdI (time-delayed-Imager) sys- and price requirements of large-scale markets – see figure 4. tems. at the same time, the market demand for imager-based With a more classical imager point of view, there are numer- system solutions is growing at a steady pace. should we as- ous options to combine intelligent pixels with system-on-chip sume that there will always remain a “ccd market”? Maybe, but designs. Think of memory-configurable TDI line scanners with again probably not a relevant question, or at least an incomplete multiple frame storage capabilities and built-in signal process- one. the sole attempt of merely improving current imagers lacks ing and amplification. Or look at the replacement of micro- vision. channel tubes or photomultiplier tubes for near Ir detection at a With the availability of new technological options, the rel- fraction of today’s system prices as well as having the capability evant questions should circle around the new options that such to output in the digital domain. With booming imaging markets steps enable. the imaging market will continue to grow but it and requirements for better performance, higher integration and will also broaden with respect to the possible new solutions lower cost, there are plenty of opportunities. Be it in established and applications. the Espros Photonic cMOs process arguably application fields such as industrial and scientific imaging, or in delivers significant but incremental performance improvements new solutions like optical gesture control, fluorescence imaging in classic imaging aspects. It has already proven to be a radical or even particle physics. the creativity of imager specialists and innovation. Prime examples are time of Flight (tOF) cameras, system designers alike will determine where these new process which find applications in many domains. In a TOF imager, the options lead to and which product innovations they yield. Enhancing automotive safety through advanced IR sensor technology By luc Buydens OccuPaNcy classIFIcatION system (Ocs) implementations sensors embedded within the seat- have become an increasingly standard part of the safety capa- ing frame, which were used to mea- bilities found in modern cars. They offer a means by which to sure the person’s weight and from ensure that, if an impact occurs, a passenger airbag is deployed this derive a rough estimate of their in the most effective way to protect the passenger and avoid height. this, along with the other injuries. this is done by using some form of sensor technology methods of a similar nature (such to determine the height and build of the occupant. the follow- as sensing the tension in the seat- ing article looks at how the progression to next generation Ocs belt) still left room for inaccuracies. is helping to assure passenger wellbeing to a much greater the correlation between weight degree. and height is not that well defined. also it is not possible to take into the basic structure of an Ocs is as follows - a sensor sys- account the possibility that instead tem will start by confirming whether or not there is a passenger of a passenger occupying the seat occupying the seat, then it assesses the passenger’s physical it could in fact be boxes that were characteristics. this information is subsequently passed to placed there, for instance, as there an electronic control unit (Ecu) which gauges the appropriate is no a way of confirming whether a response so that the air bag is triggered at full speed or at a human being or an inanimate object slower rate. Early systems tended to employ reasonably basic is in the seat. Integration of sensors sensing mechanisms. these consisted, for example, of pressure into the seating frame is also costly, especially if repair or replacement Fig. 1: the Melexis FIRray luc Buydens is Marketing Manager of Infrared sensor Products needs to be done. infrared sensor array. at Melexis – www.melexis.com 30 Electronic Engineering Times Europe September 2012 www.electronics-eetimes.com


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