Dr. Johannes Heidenhain Gmbh

Johannes Heidenhain Gmbh

Karsten Saendig

Wolfgang Holzapfel

Michael Hermann

Johannes Trautner

Gerhard Bock

An optical position-measuring device for sensing a position of two relatively movable objects includes a scale connected to one object and having a measuring graduation. A scanning unit is disposed on the other object and has optical elements. An arrangement and design of the optical elements of the scanning unit results in a scanning beam path in which split and subsequently interfered sub-beams propagate mirror-symmetrically with respect to a plane of symmetry and either impinge on and/or are reflected back from the scale in a V-shape. The plane of symmetry is tilted by a defined tilt angle relative to the scale about an axis of rotation that is oriented parallel to a surface of the scale and extends perpendicular to the graduation direction. The sub-beams that are interfered are deflected at the measuring graduation into symmetric diffraction orders. The sub-beams travel identical optical path lengths between splitting and recombination.

Optical position-measuring device

An optical position-measuring device includes a scanning unit and a material measure that is movable relative thereto in a measuring direction. The scanning unit includes a splitting device and an optoelectronic detector arrangement. The splitting device is configured to separate sub-beams incident thereon as a function of wavelength. The splitting device is configured as an asymmetrical interferometer that includes two interferometer arms having different optical path lengths, within which the sub-beams propagate between splitting and recombination until the recombined sub-beams arrive at the detector arrangement. The optical position-measuring device is configured to generate a plurality of phase-shifted scanning signals indicative of a relative position of the scanning unit and of the material measure, wherein phase relations of the generated phase-shifted scanning signals are wavelength-dependent.

Optical position measuring device for generating wavelength-dependent scanning signals

The present invention relates to an optical position-measuring device for generating a plurality of phase-shifted scanning signals regarding the relative position of a fiber optic scanning head and a reflection measuring standard movable relative thereto in at least one measuring direction. In the fiber optic scanning head, a scanning reticle is disposed before the measuring standard end of an optical fiber. The scanning signals are coded in a wavelength-dependent manner. To this end, a beam incident on the scanning reticle is split into at least two sub-beams which strike the reflection measuring standard and are subsequently recombined to interfere with each other so as to generate the phase-shifted scanning signals. The sub-beams travel different optical path lengths between splitting and recombination.

A position-measuring device includes a cylindrical object rotatable about a longitudinal axis and having a circumferential annular reflection measuring graduation. A stationary scanning unit is disposed opposite the cylindrical object and has a light source, a transmission grating and a detector. The scanning unit is configured to optically scan the reflection measuring graduation by beams of light emitted from the light source passing through the transmission grating and then striking the reflection measuring graduation, from where the beams of light are reflected back toward the detector, which is configured to generate rotation-dependent position signals. An optically effective perpendicular distance between the detector and the reflection measuring graduation is selected to be one of greater or less than an optically effective perpendicular distance between the transmission grating and the reflection measuring graduation depending on a radius of the cylindrical object.

Position-measuring device

A measuring device for determining the relative offset between two components in a z-direction includes two measuring members. A first measuring member is affixable on a first component, and the second measuring member is affixable on a second component. Furthermore, the measuring device includes a sensor device for determining the relative position of the two measuring members. The first measuring member and the second measuring member are affixable on the first components at a rigid angle. At least one of the measuring members is able to be brought into adhesive contact with the first component or the second component. The measuring device includes support members for at least one measuring member so that the measuring member is able to assume a parking or an operating position. The measuring members are precisely and reproducibly aligned in space relative to each other in the parking position.

Measuring device for determining the relative offset between two components

A position-measuring device includes a scanning unit and a measuring graduation that is displaceable thereto in at least one measuring direction. The measuring graduation includes two incremental-graduation tracks extending in parallel in the measuring direction, between which a reference-marking track having at least one reference marking at a reference position extends. The scanning unit includes a first scanning device for generating the reference-pulse signal and a second scanning device for generating the incremental signals. To generate the incremental signals, a scanning beam acts at least once upon each incremental graduation in an incremental-signal scanning field.

A position-measuring device for generating a reference-pulse signal at at least one reference position includes a scanning unit and also a reflection-measuring graduation displaceable relative thereto in at least one measuring direction. The scanning unit for generating the reference-pulse signal includes a plurality of optical elements, including at least one imaging optics as well as at least two diaphragm structures, which are disposed in a diaphragm plane and have a plurality of diaphragm openings in each case. Furthermore, a light source as well as at least two detector elements are assigned to the scanning unit. The reflection-measuring graduation has a reference marking at the at least one reference position. It includes at least one set of first structure elements, which is arranged in the plane of the reflection-measuring graduation, perpendicular to the measuring direction, periodically at a first transversal periodicity. Furthermore, the reference marking has at least one set of second structure elements, which is arranged in the plane of the reflection-measuring graduation, perpendicular to the measuring direction, periodically at a second, different transversal periodicity. The structure elements are arranged as diffractive structure elements, which, in the measuring direction, optically act like a cylinder lens having a specific focal length and, perpendicular to the measuring direction, act like a deflecting grating having the graduation period.

A position-measuring device for generating a measuring signal includes a track, which has an incremental graduation having a specified graduation period that extends along a measuring direction, having at least one discontinuity of the incremental graduation at a reference position for generating a reference signal and having a scanning unit movable relative to the track along the measuring direction, for scanning the incremental graduation, the at least one discontinuity formed by a modification of a transverse substructure of the incremental graduation that extends perpendicular to the measuring direction, and that deflects radiation beams originating from the scanning unit. The deflection direction at the discontinuity deviates from the deflection direction in other regions of the incremental graduation. The scanning unit includes at least two reference-pulse detectors provided for receiving radiation beams having a different deflection direction. Upstream of the reference-pulse detectors, at least one imaging optics system is arranged in the beam path of the respective deflected radiation beam.

In a position measuring system and a method for operating such a position measuring system, e.g., for the purpose of producing at least one reference pulse signal, the position measuring system includes a gauge with a track in which a periodic incremental scale is disposed and extends in one direction of measurement. The track displays a discontinuity with respect to an optical property in at least one defined reference position. The position measuring system further a scanner unit that may be displaced across a predetermined measuring length relative to the gauge in the direction of measurement and that is provided, in addition to a light source, with a plurality of detector elements for the photoelectric scanning of the incremental scale. In adjacent sections of the measuring length, the incremental scale has different transverse substructures that deflect incident ray beams in first and second directions in space. Reference pulse detectors are disposed in the various directions in space on the scanning unit end and are supplied with partial reference pulse signals or area signals which are processed to give the reference pulse signal.

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Palling, Germany

Karsten Saendig