Verfahren zum Verguss von einer LED-Leuchte für den Einsatz in der Tiefsee und LED-Leuchte

Die Erfindung betrifft eine Tiefsee- LED-Leuchte-Vergussverfahren mit den Schritten: Konfigu- ration einer LED-Leuchte mit mindestens einer LED mit je- weiliger elektrisch kontaktierender Zuleitung; Einbringung der konfigurierten LED-Leuchte in eine Vergussform und Fixierung zumindest einer Zuleitung an der Vergussform, wobei zu vergießende Bauteile der LED-Leuchte die Wan- dungen der Vergussform nicht berühren; Verschwenken der Vergussform relativ zur Umgebung in einem Schwerkraft- system; Einbringen einer Vergussmasse in die Verguss- form bis die zu vergießenden Bauteile der LED-Leuchte voll- ständig mit der Vergussmasse umschlossen sind; optische Qualitätskontrolle auf Blasenfreiheit der Vergussmasse wäh- rend des Aushärtens und bedarfsweise wiederholendes Ver- schwenken der Vergussform, so dass innerhalb der Ver- gussmasse befindliche Blasen bzw. Gaseinschlüsse aus der Vergussmasse herausgefördert sind. Ferner betrifft die Erfindung eine LED-Leuchte mit mindes- tens einer LED, mindestens einer die LED elektrisch kon- taktierenden und mit Energie versorgenden Zuleitung, wobei die LED in einer Vergussmasse angeordnet ist, wobei die mindestens eine LED sowie optionale Bauteile der Tiefsee- LED-Leuchte und/oder gemeinsame oder jeweilige Träger und/oder Schnittstellen und/oder elektronische Bauteile voll- ständig von der Vergussmasse umschlossen sind

Optical Underwater Communication: The Potential of Using Converted Green LEDs in Coastal Waters

Compared to the open ocean where blue light-emitting diodes (LEDs) perform well for data communications, in coastal and harbor environments optical transmission becomes worse and the color of lowest attenuation shifts to green. Another problem concerns the “green–yellow gap” of LEDs, as the quantum efficiency of current commercially available green LEDs is poor. Since energy consumption is an important factor, particularly for battery-powered systems, using blue LEDs is a tradeoff. Recently, phosphor-converted green LEDs, which are pumped by highly efficient blue LEDs, have been introduced to the market, and this type of LED promises better performance. This paper compares the use of blue, green, and converted green LEDs for applications in optical underwater communication systems in coastal waters. Theoretical aspects of the overall LED-water-detector channel are presented. A method for determining individual system coefficients is developed, and the impact on the communication system performance is explained. Practical approaches are introduced, complemented by measurements in the Baltic Sea

Experimental Characterization of Single-Color Power LEDs Used as Photodetectors

Semiconductor-based light emitting diodes can be used for photon emission as well as for detection of photons. In this paper, we present a fair comparison between off-the-shelf power Light emitting diodes (LEDs) and a silicon photodetector with respect to their spectral, temporal, and spatial properties. The examined LED series features unexpected good sensitivity and distinct optical bandpass characteristic suitable for daylight filtering or color selectivity. Primary application is short range optical underwater communication, but results are generally applicable

Verfahren und Vorrichtung zur Herstellung von in Vergussmasse vergossenen Leuchten

Die Erfindung betrifft ein Leuchten-Vergussverfahren mit den Schritten: Einbringen einer konfigurierten und mit einer optisch-transparenten Vergussmasse zu vergießenden Leuchte in eine wenigstens teilweise optisch-transparente Vergussform (16), wobei die Vergussform (16) in einer Vakuumkammer (11) angeordnet ist und die Leuchte in der Vergussform (16) derart fixiert wird, dass die Leuchte die Wandungen der Vergussform nicht berühren; Einbringen einer optisch-transparenten Vergussmasse (18) in die Vergussform (16) bis die Leuchte umschlossen ist; Detektion einer Quantität und Qualität einer Blasenfreiheit der optisch-transparenten Vergussmasse (18) durch einen optischen Sensor oder Bilddetektor (14), wobei eine Regelung des Druckes in der Vakuumkammer (11) zur Beeinflussung der Blasen und/oder eine Regelung einer Schwenk-/Neigevorrichtung (12) zur Bewegung der Vakuumkammer (11) und/oder der Vergussform (16) zur Austreibung detektierter Gas-/Luftblasen (19) aus der optisch-transparenten Vergussmasse (18) erfolgt. Ferner betrifft die Erfindung eine Verguss-Leuchten-Herstellungsvorrichtung mit: einer Vakuumkammer (11), einer wenigstens teilweise optisch-transparenten Vergussform (16) zur Aufnahme einer mit einer optisch-transparenten Vergussmasse zu vergießenden Leuchte, einer Druckmesseinrichtung (15) mit einer Druckregelung für den Druck innerhalb der Vakuumkammer (11), einem Bilddetektor (14) zur Detektion von Gas-/Luftblasen innerhalb der wenigstens teilweise optisch-transparenten Vergussform (16), eine Schwenk-/Neigevorrichtung (12) zum direkten oder indirekten Schwenken und Neigen der wenigstens teilweise optisch-transparenten Vergussform (16) durch Verschwenken und/oder Neigen der wenigstens teilweise optisch-transparenten Vergussform (16) oder der Vakuumkammer (11), einer Auswerte-, Speicherungs- und Regelungseinheit zur Regelung der Schwenk-/Neigevorrichtung (12) und/oder des Druckes innerhalb der Vakuumkammer (11)

Effects and Constraints of Optical Filtering on Ambient Light Suppression in LED-Based Underwater Communications

Optical communication promises to be a high-rate supplement for acoustic communication in short-range underwater applications. In the photic zone of oceanic and coastal waters, underwater optical communication systems are exposed by remaining sunlight. This ambient light generates additional noise in photodetectors, thus degrading system performance. This effect can be diminished by the use of optical filters. This paper investigates light field characteristics of different water types and potential interactions with optical underwater communication. A colored glass and different thin film bandpass filters are examined as filter/detector combinations under varying light and water conditions, and their physical constraints are depicted. This is underlined by various spectral measurements as well as optical signal-to-noise ratio calculations. The importance of matching the characteristics of the light emitting diode (LED) light source, the photodetector, and the filter on the ambient conditions using wider angle of incidents is emphasized

TuLUMIS - a tunable LED-based underwater multispectral imaging system

Multispectral imaging (MSI) is widely used in terrestrial applications to help increase the discriminability between objects of interest. While MSI has shown potential for underwater geological and biological surveys, it is thus far rarely applied underwater. This is primarily due to the fact light propagation in water is subject to wavelength dependent attenuation and tough working conditions in the deep ocean. In this paper, a novel underwater MSI system based on a tunable light source is presented which employs a monochrome still image camera with flashing, pressure neutral color LEDs. Laboratory experiments and field tests were performed. Results from the lab experiments show an improvement of 76.66% on discriminating colors on a checkerboard by using the proposed imaging system over the use of an RGB camera. The field tests provided in situ MSI observations of pelagic fauna, and showed the first evidence that the system is capable of acquiring useful imagery under real marine conditions

DeepSurveyCam — A Deep Ocean Optical Mapping System

Underwater photogrammetry and in particular systematic visual surveys of the deep sea are by far less developed than similar techniques on land or in space. The main challenges are the rough conditions with extremely high pressure, the accessibility of target areas (container and ship deployment of robust sensors, then diving for hours to the ocean floor), and the limitations of localization technologies (no GPS). The absence of natural light complicates energy budget considerations for deep diving flash-equipped drones. Refraction effects influence geometric image formation considerations with respect to field of view and focus, while attenuation and scattering degrade the radiometric image quality and limit the effective visibility. As an improvement on the stated issues, we present an AUV-based optical system intended for autonomous visual mapping of large areas of the seafloor (square kilometers) in up to 6000 m water depth. We compare it to existing systems and discuss tradeoffs such as resolution vs. mapped area and show results from a recent deployment with 90,000 mapped square meters of deep ocean floor

Underwater Optical Wireless Communications in Swarm Robotics: A Tutorial

Underwater swarm robotics is an emerging topic.Compared to individual autonomous vehicles, high-capacity com-munication links are required between the mobile agents. In thistutorial, suitable communication technologies are studied, withemphasis on LED-based underwater optical wireless communica-tions. A comprehensive overview about challenges, advances, andpractical aspects of underwater swarm robotics employing opticalwireless communications is provided. The tutorial includes thefollowing topics: (1) Channel modeling fundamentals; (2) Physicallayer transmission techniques for underwater optical wirelesscommunications; (3) Data link layer aspects and hybrid trans-mission schemes; (4) Ambient light and interference suppression;and (5) Realization aspects. Finally, suggestions regarding futurework are given. The tutorial is intended for readers with abackground or interest in electrical and information engineering