Up to now, in state-of-the-art technologies, 3D information was captured either passively by calculating the information from pictures of different perspective angles (triangulation), e.g in stereoscopic cameras, or actively by time-of-flight measurements (ToF). Both traditional technologies use up a large amount of computing power and often require postproduction processing. Now, the BASF sensor works passively with only one lens, and it does not need triangulation for the 3D data capture; this significantly decreases the demand for computing power and makes the 3D data capture very fast: with the new BASF 3D sensor technology real-time 3D imaging may find it’s way into our daily lives."
BASF 3D Sensor |
A 120 page-long patent application WO2012110924 "Detector for optically detecting at least one object" by Mohamedi Haroun Al, Ingmar Bruder, Felix Eickemeyer, Peter Erk, Stephan Irle, Andreas Pelster, RĂ¼diger Sens, and Erwin Thiel, explains how it works:
"the invention is based generally on the hitherto unreported and surprising insight that specific optical sensors exist whose sensor signal is not only dependent on a total light power of the illumination of the sensor region, for example of the sensor area, of these sensors but in which a pronounced signal dependence on a geometry of the illumination, for example a size of a light spot of the illumination on the sensor region, for example the sensor area, also exists. This is generally not the case for most conventional optical sensors, in particular for most inorganic semiconductor sensors, since here the sensor signal is generally dependent only on a total power of the illumination, that is to say an integral over the intensity over the entire light spot which is generally independent of the size of the light spot, that is to say the geometry of the illumination, as long as the light spot lies within the limits of the sensor region. It has surprisingly been discovered, however, that in specific optical sensors, for example organic optical sensors, such a dependence of the sensor signal occurs in which the sensor signal on the one hand rises with the total power of the illumination, but on the other hand, even given a constant total power, is dependent on a geometry of the illumination. Examples of such optical sensors are explained in even greater detail below. By way of example, the sensor signal, given the same total power, can have at least one pronounced maximum for one or a plurality of focusings and/or for one or a plurality of specific sizes of the light spot on the sensor area or within the sensor region."
The application then states that the organic dye-based sensor's response changes if the light is modulated, and using a modulation at different frequencies at two sensors, one can separate illumination and geometrical data. Then the description says:
"In contrast to known detectors, in which a spatial resolution and/or imaging of objects is also generally tied to the fact that the smallest possible sensor areas are used, for example the smallest possible pixels in the case of CCD chips, the sensor region of the proposed detector can be embodied in a very large fashion, in principle, since for example the geometrical information, in particular the at least one item of location information, about the object can be generated from a known relationship for example between the geometry of the illumination and the sensor signal."
The application does not explain much about the processing and how the distance is measured:
The last part of the application is filled by rows of organic chemistry formulas, not sure what they mean:
I wonder if the detection is made by using transparent multi-sheet pixel arrays so that the illumination pattern variation can be detected by successive sensor sheets ...
ReplyDelete-yang ni
It might be easier to follow along at Google Patents in a browser.
ReplyDeletehttps://www.google.com/patents/US20120206336
The important line is: "the invention relates to a method for optically detecting at least one object and to a use of an organic solar cell as optical sensor"
The organic synthesis described at the end is an example synthesis of a dye that can be used in an solid dye sensitized solar cell for the the sensor. That sensor design is described in the second "ORGANIC SENSOR" (154).
There are no pixels involved! Well, just one. But there is no imaging involved so this isn't going to replace a gesture recognition sensor. It's a sort of rangefinder. The geometry is inferred from the change in response of the output as the illumination is changed.
The whole invention relies on the "bug/feature" of these solar cell detectors that the output varies with spot size even when the total amount of light in the spot is the same.
Interesting idea.
kgp
Thanks KGP for this explanation !
DeleteIf I understand well, this organic solar cell output changes with the light intensity distribution on the cell even the total light power is the same.
-yang ni
Thanks KGP. This was my understanding too.
DeleteWere you able to figure out why they need a light modulator in front of the sensor there, and operate it at different frequencies?
> "There are no pixels involved! Well, just one. But there is no imaging involved so this isn't going to replace a gesture recognition sensor. It's a sort of rangefinder ..."
DeleteI do not understand that, when the PDF says this:
"Now, the BASF sensor works passively [2] with only one lens, and it does not need triangulation for the 3D data capture; this significantly decreases the demand for computing power and makes the 3D data capture very fast: with the new BASF 3D sensor technology real-time 3D imaging ...".
...
"The judicious interplay of chemistry, materials science, and physics yields a system solution that is capable of tracking, imaging, and processing objects in 3D, all at about twice the rate our human eyes and brain can. With an unprecedented combination of high precision, high speed, and high resolution, "
...
"In combination with appropriate software, the sensor can also be used for purposes beyond imaging, such as autofocus, object, gesture, facial, and body expression recognition. 3D video conferencing is naturally an other possibility. "
[Footnote 2] It is not sending out any signal which is used to calculate distance
This explanation is offered here: http://www.standort-ludwigshafen.basf.de/group/corporate/site-ludwigshafen/en_GB/innovations/global-r-d-network/research-areas/biological-and-effect-systems-research
ReplyDelete"The New BASF 3D Sensor Technology
A new physical effect in combination with chemistry from BASF enables passive distance measurement, 3D position detection, and 3D imaging as never before.
Read more... (doctype pdf, 145 kb)".
http://www.standort-ludwigshafen.basf.de/group/corporate/site-ludwigshafen/en_GB/function/conversions:/publishdownload/content/innovations/global-r-d-network/research-areas/data/3D-imaging-technology.pdf
There is a new side view Image:
http://www.standort-ludwigshafen.basf.de/group/corporate/site-ludwigshafen/en_GB/function/conversions:/publish/content/innovations/global-r-d-network/research-areas/images/3D-Sensor-Technology.jpg
Interestingly, the original patent was sought through WIPO though BASF's China branch in 2012.
ReplyDeletehttp://worldwide.espacenet.com/publicationDetails/originalDocument?CC=WO&NR=2012110924A1&KC=A1&FT=D&ND=&date=20120823&DB=&locale=en_EP
-RT