KEYWORDS: Sensors, Calibration, Cameras, 3D acquisition, 3D metrology, Sensor calibration, Projection systems, Digital Light Processing, Image resolution, 3D image processing
We present new developments in optical 3d sensors using pico DLP as well as DSP technology. We
use enhanced, high-powered pico DLP projection units and compact processing hardware to create
likewise compact, light-weight measuring heads, which can perform the acquisition as well as the
evaluation of 3D data without external computing power. Moreover, their drastically reduced cost and
their networking ability also allows for an economical combination of a multitude of individual sensors
into complex configurations. The entire form even of large and complex shapes can hereby be scanned
in a very short time. New calibration strategies, integrating all individual sensor coordinate systems into
a single, calibrated, global one, lead to an immediate combination of all sensor data into a single,
complete point cloud. We show the principle and actual realization of sensors, calibration strategies
and procedures, and examples of first realized multi-sensor measuring systems utilizing this new technology.
The skin is not only the largest organ of the human body, but it is also a barrier to the environment. The major part of the human skin is in constant contact with textile materials. The objective of this study was to characterize textile materials and to investigate their influence on the skin properties. For this purpose, two different textile materials (polyamide and polyester) were objectively characterized by optical coherence tomography and surface structure 3D-profilometry. In addition, subjective textile properties like haptic sensation and stiffness, as tactile characteristics felt by volunteers, were analyzed. The objective textile characteristics and subjective parameters were compared to the barrier properties measured by in vivo laser scanning microscopy . Comparable results were achieved between barrier properties and subjective assessment in relation to the textile characteristics in favor of the polyester fabric. Consequently, the optical method used in dermatology for the analysis of the skin can be applied to characterize and evaluate textile fabrics and their interaction with human skin in vivo.
KEYWORDS: 3D image processing, Sensors, 3D metrology, 3D acquisition, Cameras, Inspection, Digital signal processing, Digital Light Processing, Image processing, Data acquisition
GFM has developed and constructed DLP-based optical 3D measuring devices based on structured
light illumination. Over the years the devices have been used in industrial metrology and life sciences
for different 3D measuring tasks. This lecture will discuss integration of DLP Pico technology and
DSP technology from Texas Instruments for mass market optical 3D sensors. In comparison to existing
mass market laser triangulation sensors, the new 3D sensors provide a full-field measurement of up to
a million points in less than a second. The lecture will further discuss different fields of application and
advantages of the new generation of 3D sensors for: OEM application in industrial measuring and inspection;
3D metrology in industry, life sciences and biometrics, and industrial image processing.
Since the mid-eighties, a fundamental idea for achieving measuring accuracy in projected fringe technology
was to consider the projected fringe pattern as an interferogram and evaluate it on the basis of
advanced algorithms widely used for phase measuring in real-time interferometry. A fundamental requirement
for obtaining a sufficiently high degree of measuring accuracy with this so-called "phase
measuring projected fringe technology" is that the projected fringes, analogous to interference fringes,
must have a cos2-shaped intensity distribution. Until the mid-nineties, this requirement for the projected
fringe pattern measurement technology presented a basic handicap for its wide application in 3D
metrology. This situation changed abruptly, when in the nineties Texas Instruments introduced to the
market advanced digital light projection on the basis of micro mirror based projection systems, socalled
DLP technology, which also facilitated the generation and projection of cos2-shaped intensity
and/or fringe patterns. With this DLP technology, which from its original approach was actually
oriented towards completely different applications such as multimedia projection, Texas Instruments
boosted phase-measuring fringe projection in optical 3D metrology to a worldwide breakthrough both
for medical as well as industrial applications. A subject matter of the lecture will be to present the fundamental
principles and the resulting advantages of optical 3D metrology based on phase-measuring
fringe projection using DLP technology. Further will be presented and discussed applications of the
measurement technology in medical engineering and industrial metrology.
KEYWORDS: 3D metrology, Facial recognition systems, Biometrics, 3D scanning, 3D acquisition, Micromirrors, Light sources, Glasses, Safety, Control systems
Facial recognitions of people can be used for the identification of individuals, or can serve as verification e.g. for access
controls. The process requires, that the facial data is captured and then compared with stored reference data.
In this context, far better recognition performances can be expected from 3-dimensional facial recognition systems than
can be from the 2-dimensional systems which are currently used. The accuracy with which the facial profile can be captured, depends on the speed off the measuring data acquisition i.e. the scanning speed and on the measuring accuracy of the measuring device i.e. the 3D scanner.
The application of fast 3D measuring methods is a fundamental venture in industrial measuring technology. This paper
introduces the digital fringe projection technology based on the Digital Light Projection technology (DLP) from Texas
Instruments as a measuring method for inline 3D measurement and inspection for industrial use. In this paper in the first
part will be described the fundamental principles of the used 3D measuring method and the calibration of the measuring
devices. In the second part will be described and/or represented the special needs of the hard and software components
enabling the application of the digital fringe projection technology as a 3D inline measuring method for manufacturing
systems. In a third part of the paper is described an inline system for 3D measurement and/or inspection of electronic components.
Based on the experiences made with NanoMES the interferometric in situ measuring devices in real-time and during plasma etching of micro- and opto-electronic devices GFM designed a new optical system for interference and imaging. Also the measuring program was upgraded from a 1 dimensional analysis of interference stripes to a 2 dimensional evaluation. GFM and FBH have a Patent that makes it possible to measure distances that are much shorter than the wavelength of the used laser for the interferometer. The optical positioning of the wafers in the etching chambers poses a problem for standard optical imaging, since the objects are very far from the camera lens. Therefore it is impossible to use normal long distance microscope lenses. The new modular design allows special adaptations for special problems and variable magnifications. If required a zoom lens module could be integrated. Another problem for the interferometer are vibrations and shocks. The previous NanoMES used a pulsed laser diode for stroboscopic imaging of the interference stripes. The new measuring system is able to work with a continuous mode (cw) laser. That opens the view for new possible applications. The new NanoMES is developed and tested at the FBH.
In medicine, a change in the documentation of rendered services and therapeutic results is currently taking place. Previously, simple standards were sufficed to document the quality and effectiveness of a treatment. In the case of surgical and dermatological treatments, the therapy was initiated according to diagnosis and indication and ended with a histological examination and confirmation of the diagnosis by the pathologist. Newer therapeutic methods, e.g., laser surgery, conservatively treat and remove pathological changes in the skin surface, without the possibility of sending a specimen to the pathologist. Diagnostics must therefore be capable of documenting the dynamic effects of the treatment in the initial phase and subsequent development of the disease. To make it possible to achieve this goal, fast and exactly working 3D invivo measurement methods are necessary, which permit a direct access to the three-dimensionality of the human skin surface. With the digital fringe projection based on micromirror projectors from the Texas Instruments company and the PRIMOS technology, respectively, a new optical 3D measurement method is presented, which makes it possible to measure human skin surfaces fast and very accurately both in the micro and macro-ranges and to document treatment results objectively.
A Digital Micromirror Device (DMD) consists of an array of e.g. 1024 x786 small micromirrors. Each of these mirrors has a size of 16 μm and can be individually switched to an angle of +10° or -10°. Depending on how these micromirror pixels are switched various reflected patterns or images can be projected digitally when the DMD is properly illuminated. Whereas classical applications for DMDs include digital image- and video-projection, further applications in the field of optical metrology are possible as well. Since the DMD can also act as a pinhole, a new type of optical surface- profiler resembling a confocal microscope but using the DMD for flexible illumination and lateral scanning of the specimen has currently been set up at the Fraunhofer IPT. There are various process-parameters that influence the measurement, among these are e.g. pinhole-size, pinhole- shape, lateral step-size and the number of pinholes used simultaneously. With the presented instrument these process-parameters can not only be easily configured for individual measurements by simply programming the DMD, but also adaptive control of these parameters during the measurement may be achieved. The paper explains basics of DMD technology and confocal microscopy, illustrates the principle of the newly designed instrument, discusses difficulties and shows first results achieved with a set-up demonstrator.
The fast, contact-free and highly precise shape measurement of technical objects is of key importance in the scientific- technological area as well as the area of practical measurement technology. The application areas of contact- free surface measurement extend across widely different areas, e.g., the automation of production processes, the measurement and inspection of components in microsystem technology or the fast 3D in-vivo measurement of human skin surfaces in cosmetics and medical technology. This paper describes methodological and technological possibilities as well as measurement technology applications for fast optical 3D shape measurements using micromirror-based high-velocity stripe projection. Depending on the available projector and camera facilities, it will be possible to shoot and evaluate compete 3D surface profiles within only a few milliseconds.
Surface measurement technology's growing demand for fast and highly accurate data processing and representation results from the need to automate measuring processes and to raise quality control requirements in production. Measuring micro and macro profiles as well as surface roughness in production-related areas is a task that increasingly faces industrial production. Optical and particularly interferometrical methods of micro and macro surface investigation are especially favorable by virtue of their ability to measure without physical contact and therefore nondestructively and with high speed.
Parameters which describe the surface topoqraphy in terms are the spatial frequencies the qr of the siope They will become hiqher values f the object under investigation is a rough sample. The range of these parameters what can be detected is limited by the method o measuremnt including signal evaluation. The aim of this paper is to deal w)th the range of these parameters using the method of spatial heterodyne technique: I
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.