Dr. Johannes Heidenhain Gmbh

Johannes Heidenhain Gmbh

Andreas Franz

Dieter Michel

Wolfgang Holzapfel

Erwin Spanner

Michael Allgauer

Elmar Josef Mayer

Walter Huber

Peter Speckbacher

Georg Flatscher

Erich Bayer

Dieter Jestel

Jurgen Thiel

An incremental position measuring system in the form of a three-grating sensor is optimized in such a way, that the degree of modulation (M) of the incremental scanning device, as well as the intensity (I) of a reference marker signal are relatively strong. To this end, a phase grating with an effective phase deviation of &lgr;/4 is embodied on a scale , as well as a reference marker (R) in the form of an amplitude structure. A compact structure is achieved by the divergent illumination of the grating located in front of the scale.

Photoelectric position measuring system that optimizes modulation of a scanning device and the intensity of a reference mark signal

The phase grating of the present invention includes a substrate with a reflective, continuous layer disposed thereon on which a structured spacer layer 3 of dielectric material is applied. To form a phase grating that can be used as a scale in photoelectric position measuring instruments, a further thin reflective surface layer is located solely on the reflective, continuous surfaces, parallel to the layer, of the structured spacer layer.

Phase grating and method of producing phase grating

An uncovered unprotected phase grating includes a substrate which has a relief structure. The relief structure includes a high-refraction material so that even if soiled with impeding ambient media an adequate difference in the index of refraction exists and the diffraction effect is preserved.

Phase grating having an unprotected relief structure with a grating

An absolute measuring interferometer having a measuring interferometer, a tunable laser emitting a laser beam and a control interferometer for adjusting the air wavelength of the laser beam. The control interferometer adjusts the air wavelength of the laser beam to a specific wavelength value at the ends of each measuring cycle. The wavelength of the tunable laser is continually tuned within the specific wavelength interval where the phase change of the interference signal is continually detected during the wavelength modulation process. An absolute measurement is determined by a simple mathematical relationship between the measured wavelength and phase changes.

Absolute interferometer measuring process and apparatus having a

A position measuring method and apparatus for obtaining signals substantially free of harmonics with the aid of a periodic graduation and a non-periodic or aperiodic scanning graduation, wherein the position of the grating lines n within the scanning graduation is determined in accordance with a statistical distribution.

Position measuring method and apparatus for generating periodic signals

A light source which emits light in strips is provided for illuminating a scale of a photoelectric position measuring system. The light modulated by the scale is converted into a sinusoidal scanning signal by a scanning plate. The scanning plate is a semiconductor substrate structured in strips. The width (A) of the light-emitting areas and the width (B) of the interspersed non-emitting areas of the light source is such that defined harmonics are filtered out of the scanning signal. The scanning plate is of such configuration that further harmonics are suppressed.

Photoelectric position measuring system using gratings having specified

An interferometer having a light source that generates a beam of light. The beam of light is directed to a beam splitter where it is split into a reference beam and a measuring beam. A pair of reflectors reflect the reference and measuring beams towards an interference point. A beam merging element is positioned at the interference point so that the reference and measuring beams interfere with each other at the interference point so that at least two pairs of partial beams which are phase-shifted in relation to each other and interfere with one another are generated. The two pairs of partial beams are received by a plurality of detectors which form directionally dependent measured values.

Dual-beam interferometer with a phase grating

Waveguide type displacement interferometer having two reference paths

A measurement device having a correction grating associated with a gauge and deflects two diffracted partial beams overlappingly, at a very small angle (.alpha.), onto a single coupling grating. From there, two waveguides located closely beside one another are used to introduce the beams into a coupler and the beams are superimposed and evaluated in a known manner. Thus, a position measuring device can be drastically reduced in its structural size with the aid of an integrated optical component.

Device for coupling and/or decoupling beams of light, with an integrated

An interference type angle measuring device has a graduated disk with a circular graduation. This circular graduation is scanned by a scanning device, which is constructed as a monolithically integrated optical circuit with two diametrical scanning areas. Simply structured coupling and decoupling grids are used as coupling elements, which have also simply constructed correction grids placed upstream or downstream thereof.

Angle measuring device with correction grid

In an arrangement with at least one waveguide coupler, two photo beam bundles are supplied to both of the inputs of the waveguide coupler by two input grids and are brought to interference in the coupling area. A damping element is provided in the coupling area of the waveguide coupler for obtaining at the two outputs two signals having a mutual phase shift of other than 180.degree. by two detectors.

Apparatus and method having at least one waveguide coupler to create at

In an integrated optical arrangement, such as a photoelectric position measuring arrangement, a diffraction grid is scanned by light beam diffraction by a scanning unit having a laser. A light beam bundle emanating from the laser is split by the diffraction grid into two diffraction beam bundles, which are inserted into the top input waveguides of a waveguide coupler by two coupling elements. The two diffraction beam bundles interfere in the waveguide coupler and impinge on three detectors located at three output waveguides of the waveguide coupler for obtaining measured values. For readjustment of the optimal emission wavelength of the laser, an additional diffraction beam bundle emanating from the diffraction grid is entered into said integrated optical sensor arrangement by an additional coupling element. The additional beam bundle triggers a detector for generating a control signal to control the optimal emission wavelength of the laser.

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Trostberg, Germany

Andreas Franz