Abstract: The leak detection device comprises a plurality of measuring cells (10) in whose interior the absorption of a laser beam (17) is influenced by the presence of tracer gas. All of said measuring cells (10) are connected to a host unit (25) via light-conducting fibers (28,34). In the host unit (25), a laser (26) designed for modulation and a photodetector (37) are arranged. Modulation of the laser radiation is preferably performed by two-tone frequency modulation. This has the effect that the fiber length cannot significantly skew the result of the measurement.

Abstract: A leak detector comprises a cell provided with a tracer gas inlet preferably permeable to a tracer gas. In the cell, the tracer gas is caused to assume an energetically higher metastable state. By means of laser spectroscopy the absorption spectrum of the metastable tracer gas is sampled in an optical measuring section, whereby the presence of tracer gas is detected.

Abstract: A membrane selectively permeable to light gases comprises a membrane body formed by a first plate and a second plate. The second plate comprises a thin layer that is selectively gas-permeable. In the region of windows, this layer is exposed. There, support is provided by a porous bottom wall in the first plate or by narrow bores in the second plate. A heating device causes a radiation heating of the windows.

Abstract: A membrane selectively permeable to light gases comprises a membrane body formed by a first plate and a second plate. The second plate comprises a thin layer that is selectively gas-permeable. In the region of windows, this layer is exposed. There, support is provided by a porous bottom wall in the first plate or by narrow bores in the second plate. A heating device causes a radiation heating of the windows.

Abstract: A membrane selectively permeable to light gases comprises a membrane body formed by a first plate and a second plate. The second plate comprises a thin layer that is selectively gas-permeable. In the region of windows, this layer is exposed. There, support is provided by a porous bottom wall in the first plate or by narrow bores in the second plate. A heating device causes a radiation heating of the windows.

Abstract: For leak testing, a tracer gas is advanced to the outer wall (11) of the hollow test object (10) while the test object (10) is in an evacuated state. The tracer gas is discharged from a blower device (14) in the form of soap bubbles (21). When contacting the outer wall (11), the soap bubbles will burst, thus forming a cloud (27) of tracer gas immediately on the outer wall (11). By the invention, it is made easier to localize the invisible tracer gas in the ambient air. Further, the tracer gas can be used more effectively so that the costs for performing the testing process are reduced.

Abstract: The leak detection device comprises a plurality of measuring cells (10) in whose interior the absorption of a laser beam (17) is influenced by the presence of tracer gas. All of said measuring cells (10) are connected to a host unit (25) via light-conducting fibers (28,34). In the host unit (25), a laser (26) designed for modulation and a photodetector (37) are arranged. Modulation of the laser radiation is preferably performed by two-tone frequency modulation. This has the effect that the fiber length cannot significantly skew the result of the measurement.

Abstract: A leak detector comprises a cell provided with a tracer gas inlet preferably permeable to a tracer gas. In the cell, the tracer gas is caused to assume an energetically higher metastable state. By means of laser spectroscopy the absorption spectrum of the metastable tracer gas is sampled in an optical measuring section, whereby the presence of tracer gas is detected.

Abstract: A membrane selectively permeable to light gases comprises a membrane body formed by a first plate and a second plate. The second plate comprises a thin layer that is selectively gas-permeable. In the region of windows, this layer is exposed. There, support is provided by a porous bottom wall in the first plate or by narrow bores in the second plate. A heating device causes a radiation heating of the windows.

Abstract: For leak testing, a tracer gas is advanced to the outer wall (11) of the hollow test object (10) while the test object (10) is in an evacuated state. The tracer gas is discharged from a blower device (14) in the form of soap bubbles (21). When contacting the outer wall (11), the soap bubbles will burst, thus forming a cloud (27) of tracer gas immediately on the outer wall (11). By the invention, it is made easier to localize the invisible tracer gas in the ambient air. Further, the tracer gas can be used more effectively so that the costs for performing the testing process are reduced.

Abstract: An optical information storage medium has multiple information layers. On each layer, information is stored in the form of an electroluminescent material. The pits are organized into regions called pages. A specific page on a specific layer can be addressed through electrodes integrated into the medium. The medium can be read-only or WORM. For the WORM embodiment, a recordable electroluminescent material is combined with a quencher and a free radical generating compound that, when thermally degraded, generates free radicals to bleach the quencher. To amplify the light from an information layer, a photoconductive layer and an additional electroluminescent layer can be provided.

Abstract: An optical information storage medium has multiple information layers. On each layer, information is stored in the form of an electroluminescent material. The pits are organized into regions called pages. A specific page on a specific layer can be addressed through electrodes integrated into the medium. The medium can be read-only or WORM. For the WORM embodiment, a recordable electroluminescent material is combined with a quencher and a free radical generating compound that, when thermally degraded, generates free radicals to bleach the quencher. To amplify the light from an information layer, a photoconductive layer and an additional electroluminescent layer can be provided.

Abstract: An optical information is stored in the form of an electroluminescent material. The pits are organized into regions called pages. A specific page on a specific layer can be addressed through electrodes integrated into the medium. The medium can be read-only or WORM. For the WORM embodiment, a recordable electroluminescent material is combined with a quencher and a free radical generating compound that, when thermally degraded, generates free radicals to bleach the quencher. To amplify the light from an information layer, a photoconductive layer and an additional electroluminescent layer can be provided.

Abstract: An optical information storage medium has multiple information layers. On each layer, information is stored in the form of an electroluminescent material. The pits are organized into regions called pages. A specific page on a specific layer can be addressed through electrodes integrated into the medium. The medium can be read-only or WORM. For the WORM embodiment, a recordable electroluminescent material is combined with a quencher and a free radical generating compound that, when thermally degraded, generates free radicals to bleach the quencher. To amplify the light from an information layer, a photoconductive layer and an additional electroluminescent layer can be provided.

Abstract: In an optical memory device, an electroluminescent matrix has a plurality of individually electrically addressable electroluminescent cells, each having a stack of memory cells. The electroluminescent cells are addressable by applying a biased voltage through a grid of light-transparent electrodes.

Abstract: A reverse bias voltage in combination with selective illumination can selectively write data into optical memory. The writing process can be completed quickly since parallel writing of data may be performed. The writing process generates an avalanche current that is used to change an element. The change can be destruction of the element or may be the alteration of property such as conductance or work function.

Abstract: A reverse bias voltage in combination with selective illumination can selectively write data into optical memory. The writing process can be completed quickly since parallel writing of data may be performed. The writing process generates an avalanche current that is used to change an element. The change can be destruction of the element or may be the alteration of property such as conductance or work function.

Abstract: An electroluminescent device useful as an optical memory or display. The device includes one or more device layers or elements 100. The device layers each include a substrate 200 with indentations 202, a cathode electrode layer 204 having a transparent conductor sub-layer 206 and an electron emission sub-layer 208, a pit pillar structure layer 210 with pixel pits 212, an n-type light emitting pixel material 214, a p-type light emitting pixel material 216 and anodes 218. The light emitting materials 214, 216 in the pixel pits 212 are deposited by a liquid deposition such as molecular adhesion and electro-polymerized. The pixel pits 212 may have dimensions of less than 10 &mgr;m with the smaller pixels having dimensions of less than half a micron.

Abstract: In an optical memory device, an electroluminescent matrix has a plurality of individually electrically addressable electroluminescent cells, each having a stack of memory cells. The electroluminescent cells are addressable by applying a biased voltage through a grid of light-transparent electrodes.

Abstract: An apparatus and method for reproducing information stored in a fluorescent multilayer information carrier. The apparatus utilizes auto-focusing and auto-framing techniques when reading the information to enable parallel reading from uniformly moving carrier. To avoid discontinuity in motion, an actuator with an objective lens performs periodic motion following a specific moving information page and, after the end of reading of this page, returns back to follow the next page.