Geodetic instrument with diffractive optical elements

Patent metadata

Field	Value
Publication number	US-2016004073-A1
Application number	US-201514710446-A
Country	US
Kind code	A1
Filing date	May 12, 2015
Priority date	May 13, 2014
Publication date	Jan 7, 2016
Grant date	—

Abstract

The invention relates to a geodetic instrument, in particular a geodetic telescope, for example for a theodolite, or geodetic overview, photogrammetry or axial camera, comprising an imaging optical system which defines an optical axis and comprises an observation beam path for imaging a target object by an eyepiece and/or on a camera sensor, for registering and/or providing an image of the sighted target object. According to the invention, the imaging optical system comprises at least two diffractive optical elements in the observation beam path.

First claim

1 - 15 . (canceled)

16 . A geodetic telescope for a theodolite or total station, a leveling device or a laser scanner, comprising:
an imaging optical system which defines an optical axis and comprises an observation beam path for imaging a sighted target object on an intermediate image plane observable by an eyepiece and/or on a camera sensor for providing and/or registering an image of the sighted target object, wherein: the imaging optical system has at least two diffractive optical elements in the observation beam path.

17 . The geodetic telescope according to claim 16 , wherein:
at least one of the at least two diffractive optical elements is embodied as a hybrid lens made of a refractive lens with a diffractive structure.

18 . The geodetic telescope according to claim 16 , wherein:
at least one of the at least two diffractive optical elements is embodied as a hybrid lens made of a aspherical lens or spherical lens with a diffractive structure.

19 . The geodetic telescope according to claim 16 , wherein:
the at least two diffractive optical elements is formed from glass, plastic or combinations of glass and plastic and/or are produced by replication technology.

20 . The geodetic telescope according to claim 16 , wherein:
the telescope comprises an objective assembly and a focusing member, wherein:
the objective assembly comprises a first one of the at least two diffractive optical elements as a diffractive objective component, and
the focusing member contains a second one of the at least two diffractive optical elements as diffractive focusing component, wherein this is movably arranged along the optical axis.

21 . The geodetic telescope according to claim 20 , wherein:
the objective component comprises an objective lens embodied as a hybrid lens.

22 . The geodetic telescope according to claim 20 , wherein:
the diffractive objective component comprises a material made of crown glass and/or a diffractive structure that comprises a layer material with a layer thickness of less than 0.15 mm applied by replication technology.

23 . The geodetic telescope according to claim 20 , wherein:
the diffractive objective component comprises a material made of crown glass and/or a diffractive structure that comprises a layer material with a layer thickness of less than 0.05 mm applied by replication technology.

24 . The geodetic telescope according to claim 20 , wherein:
the focusing member comprises flint glass and elements produced by replication technology or a diffractive plastic lens and a spherical flint glass lens.

25 . The geodetic telescope according to claim 20 , wherein:
the objective assembly overall includes only one optical element which is provided by one of the at least two diffractive optical elements.

26 . The geodetic telescope according to claim 20 , wherein:
the focusing member overall includes at most two optical elements of which one is provided by one of the at least two diffractive optical elements, wherein the focusing member overall includes only one optical element which is provided by one of the at least two diffractive optical elements.

27 . The geodetic telescope according to claim 16 , wherein:
the observation beam path has an eyepiece and the optical system is embodied for imaging the sighted target object on an intermediate image plane observable through the eyepiece for providing an image of the sighted target object.

28 . The geodetic telescope according to claim 20 , wherein:
the eyepiece has one of the at least two diffractive optical elements, at least three diffractive optical elements are present, and the eyepiece comprises a third one of the at least three diffractive optical elements.

29 . The geodetic telescope according to claim 16 , wherein:
at least one of the at least two diffractive optical elements has diffractive and aspherical structures, which are produced by embossing or injection molding, wherein the asphericities have small dimensions.

30 . The geodetic telescope according to claim 16 , wherein:
the at least two diffractive optical elements are embodied for chromatic corrections by means of the first order of diffraction thereof and, simultaneously, for suppressing the zero and/or higher orders of diffraction.

31 . The geodetic telescope according to claim 16 , wherein:
the at least two diffractive optical elements are embodied for chromatic corrections by means of the first order of diffraction thereof and, simultaneously, for suppressing the zero and/or higher orders of diffraction by means of generating large circles of confusion in the case of diffraction for these orders of diffraction

32 . The geodetic telescope according to claim 16 , wherein:
the at least two diffractive optical elements are embodied for chromatic corrections by means of the first order of diffraction thereof and, simultaneously, for suppressing the zero and/or higher orders of diffraction for imaging remaining intensity of higher orders of diffraction with a component of less than 5% of an overall imaging intensity.

33 . The geodetic telescope according to claim 16 , wherein:
a superposed asphere is used in at least one of the at least two diffractive optical elements for correcting spherical aberrations.

34 . The geodetic telescope according to claim 16 , wherein:
at least one lens aperture has different zones with different properties in at least one of the at least two diffractive optical elements, wherein different zones have different focal lengths, specifically for near-field optics for an electronic rangefinder.

35 . The geodetic telescope according to claim 16 , wherein:
the at least two diffractive optical elements are embodied for fulfilling different functionalities.

36 . The geodetic telescope according to claim 16 , wherein:
the at least two diffractive optical elements are embodied for imaging on different optical sensors by means of an extended focal range.

Assignees

• Leica Geosystems Ag

Inventors

• Kipfer Peter
• Lais Josef

Classifications

• G02B13/18

  with lenses having one or more non-spherical faces, e.g. for reducing geometrical aberration {(G02B13/002 takes precedence)} · CPC title

• G02B5/1814

  structurally combined with one or more further optical elements, e.g. lenses, mirrors, prisms or other diffraction gratings (G02B5/189 takes precedence) · CPC title

• G01S17/08

  for measuring distance only (indirect measurement G01S17/46; active triangulation systems G01S17/48) · CPC title

• G01S17/86

  Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders · CPC title

• G02B25/001

  Eyepieces · CPC title