Sensor Instruments Gmbh

Logitex Reinstmedientechnik Gmbh

Ernst Georg Frisch

Walter Braumandl

Hans Lettner

Xaver Kollmer

G&uuml;nther Schindler

The invention relates to a monitoring system for a conveying device for flat articles, especially wafers, which conveying device is provided with a carriage ( ) that is movable along a predetermined path next to a flat article ( ) that is located at a predetermined removal location, the carriage having a receiving device for the accommodation of the flat article ( ), which monitoring system contains a light source ( ) having a light-exit window and a light receiver ( ) having a light-admission window, whereby the light-exit window and the light-admission window are positioned in such a way that a light beam ( ) directed form the light-exit window to the light-admission window is partially covered by the carriage ( ) during its movement through the light beam, and an evaluation unit that is connected to the light receiver and that compares a target signal derived from its movement of the carriage along a target path with an actual signal derived from an actual movement of the carriage, and indicates a deviation.

Monitoring system for a conveying device for flat articles, especially wafers

In a method for determining the length of a light guide light of two different wavelengths or wavelength ranges is passed through a light guide whose length is to be measured. The ratio of incident light intensity to exit light intensity for each one of the wavelengths or wavelength ranges of the light passing through the light guide is determined. The length of the light guide is calculated based on wavelength-dependent attenuation coefficients of the light guide and the ratios of incident light intensity to exit light intensity for each one of the wavelengths or wavelength ranges of the light. The device for determining the length of a specimen light guide has a light source emitting a light beam, a device for introducing the light beam emitted by the light source into a light window of the specimen light guide, a first measuring device for determining of ratio of incident light intensity of the light beam at the light window for two different wavelengths or two wavelength ranges, and a second measuring device for determining a ratio of exit light intensity for the two different wavelengths or the two different wavelength ranges of light exiting from the exit window of the specimen light guide.

Method and device for measuring the length of a light guide

An apparatus for measuring deformation of a body includes a transmitting optical fiber for connection to a light source and having a light exit face for radiating light, and at least first and second receiving optical fibers which have their light entrance faces adjacent to each other and which can each be connected to a respective input of an evaluation unit. The optical fibers are so arranged that upon deformation of the body there is a change in the difference between the amounts of light impinging on the light entrance faces of the receiving optical fibers.

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München, Germany

Ernst Georg Frisch