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Dr DSP
MikeLC
I would like to see some examples of complicated objects (with complex ...
Innovation at home: Inside a 3-D desktop scanner
Jeffrey Brown
9/26/2010 12:18 PM EDT
Noncontact 3-D laser scanners are broken down into two major types: time-of-flight and triangulation. Time-of-flight scanners are generally used for scanning large objects such as buildings or natural structures, with the scanner located at distances measured in kilometers from the object being scanned. The most common type of time-of-flight scanner is the laser rangefinder used in sports, hunting and the military.
Triangulation, where the distance between the scanner and the object being scanned is measured in decimeters or meters, relies on the mathematically computed length of the side of a triangle formed by a laser emitter, the laser dot projected on the solid object being scanned and a camera.
The NextEngine 3D Scanner employs a variant of triangulation scanning called structured light scanning, where a pattern of laser stripes is projected on the object being scanned. Cameras are used to examine the deformation of the laser line pattern as it is swept over the solid object, and a technique similar to triangulation is used to calculate the distance of every point on the lines. The primary advantage of structured light scanners is speed since they scan multiple points or the entire field of view at once.
NextEngine developed its own MultiStripe Laser Triangulation (MLT) technology employing four twin arrays of Class 1M, 10-mW solid-state lasers and two 3-megapixel (MP) CMOS sensor camera modules. The eight lasers are managed by two Microchip PIC16F819 enhanced flash microcontrollers and two PV324 quad-output operational amplifiers from Texas Instruments. The dedicated laser control printed-circuit board is mounted to the laser assembly and connected to each laser via a three-lead flex connector.
The two 3-MP camera modules are identical in design but differ in focal length. One provides macro image capture with a field of view 5.1 x 3.8 inches, while the other provides a wide field of view 13.5 x 10.1 inches.
Mounted inside the camera modules are Omnivision
OV3121 3-MP monochrome 1/2-inch optical format image sensors. Wrapped
around each module is a spool of copper wire, which allows the modules
to be heated in order to maintain proper focus in spite of fluctuations
in ambient temperature. The camera modules serve a dual purpose, in
that they are used to capture the deformations of the laser stripes as
they pass over the object being scanned and also to capture a color
JPEG image that can be wrapped around the wireframe file.
Color images are created from a monochrome sensor, thanks to a 7-color wheel mounted in front of the two camera modules.
The laser control board, two camera modules, a
power control board and other motor and control connections lead back
to the main pc board and a Zoran Quatro 4201M system-on-chip composed
of an ARM7 67-MHz core and a 133-MHz Quatro-4 DSP core developed by
Zoran. The Zoran Quatro line of SoCs has typically been used as the
main processor in photo printers and all-in-one devices.
Volatile memory for the Zoran processor is provided by two Nanya NT5SV32M8BS 256-Mb SDRAMs, while the host PC stores the control software and passes it to the scanner via a USB connection. The remaining ICs on the main pc board are a pair of Toshiba TD62001AFG 7-channel Darlington sink drivers for the pan motor and the 7-color wheel motor and a National Semiconductor LM339M low-offset-voltage quad comparator.
IP investigation reveals potential opportunity
Documentation provided with the NextEngine
scanner and available on the company’s Web site indicated a number of
patents pending related to its 3-D scanning technology. A brief search
on NextEngine patents revealed that one of the company’s investors,
Bigfoot Ventures Ltd., is currently auctioning off 60 of the company’s
U.S. and worldwide patents. Included with the patents are patent
licenses, software and underlying code, trademarks, service marks and
registered and unregistered copyrights.
According to the notification
of disposition of intellectual property, the company has already
conducted two public auctions, with neither auction resulting in
acceptable offers.
With a belief in NextEngine’s technology, a belief
in the increasing demand for 3-D media content, and at least US$2
million in the bank, as stipulated in the notification, it appears one
can acquire 10 years worth of intellectual property surrounding the
design and development of a desktop 3-D scanner.
Whether or not you believe 3-D is the next great
innovation or a passing fad reserved for fickle moviegoers, the
investment into 3-D technology will continue unabated for at least the
near future. Rest assured Avatar and Piranha 3-D are not the pinnacle
of three-dimensional viewing.
 Click on image to enlarge. |
About the author
Jeffrey Brown is vice president for business intelligence at UBM TechInsights. He has a bachelor of science in
industrial engineering and a masters of science in management from
Purdue University.
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MikeLC
9/30/2010 4:56 AM EDT
I would like to see some examples of complicated objects (with complex concavities, etc) and their corresponding models. Cool stuff regardless!
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Dr DSP
10/14/2010 2:49 PM EDT
What,s next- the 3D Scanner, Printer and Fax?
I'd be interested in what resolution you can get. The low resolution cameras may be a bottleneck..
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