Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B21/00—Microscopes
  • G02B21/0004—Microscopes specially adapted for specific applications
  • G02B21/002—Scanning microscopes
  • G02B21/0024—Confocal scanning microscopes (CSOMs) or confocal "macroscopes"; Accessories which are not restricted to use with CSOMs, e.g. sample holders
  • G02B21/0036—Scanning details, e.g. scanning stages
  • G02B21/0048—Scanning details, e.g. scanning stages scanning mirrors, e.g. rotating or galvanomirrors, MEMS mirrors
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
  • G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
  • G02B26/0816—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements
  • G02B26/0833—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
  • G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
  • G02B26/10—Scanning systems
  • G02B26/101—Scanning systems with both horizontal and vertical deflecting means, e.g. raster or XY scanners
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
  • G02B27/64—Imaging systems using optical elements for stabilisation of the lateral and angular position of the image
  • G02B27/642—Optical derotators, i.e. systems for compensating for image rotation, e.g. using rotating prisms, mirrors

Definitions

• Scanning device for scanning an object for use in a
• the invention relates to a scanning device for scanning an object for use in a scanning microscope. Furthermore, the invention relates to a scanning microscope with a scanning device arranged in the beam path of the scanning microscope.
• MEMS scanners in the form of microelectromechanical systems
• laser scanning microscopes in particular confocal laser scanning microscopes.
• US 2008/0143196 A1 and the document US 2008/0143196 A1 are known in the prior art and are used in laser scanning microscopes, in particular confocal laser scanning microscopes.
• EP 1 719 012 B1 MEMS scanner known tilt a micromechanical mirror about two mutually perpendicular axes of rotation (2D scanner). Such MEMS scanners are also known, for example, from the company Mirrorcle Technologies, Inc.
• FIG. 4 shows a schematic diagram for illustrating a reflection of a
• the 2D scanner 12 ' is part of a scanning device 10'. Furthermore, it is shown in FIG. 4 that the 2D scanner 12 'comprises a scanning mirror 18'. With the aid of the scanner 12 ', the scanning mirror 18' is tilted about one or more axes, as is known, for example, from the document US 2008/0143196 AI. In this case, the scanner 12 'usefully arranged so that the generated
• Reflection angle ao ' between the incoming laser beam 110' and the
• reflected laser beam 112 'in a scanner rest position is always greater than the maximum optical scanning angle a s ' of the scanner 12' (see Figure 4). Especially corresponds to the maximum optical scanning angle a s ' one on the reflected
• reflection angles ao 'of greater than or equal to 45 °, often 90 °, are usually used.
• Further micromechanical scanners, so-called deformable mirror devices (DMD), are known, for example, from the document Larry J.
• the scanning mirror 18' of the known MEMS scanner 12 ' is usually elliptically shaped.
• the projected mirror surface is circular in the direction of the incoming and outgoing laser beams 110 ', 112'. This has the advantage that both main axes 32 ', 34' of the ellipse shown in Figure 4
• an optical field rotator is known from the prior art, as used in high-quality laser scanning microscopes.
• an optical field rotator is described in document EP 0 950 206 B1.
• This known field rotator is an optical module which comprises a rotatable Abbe or Dove prism. The operation of these prisms is known in the art and, for example, in the document William L. Wolfe: Chapter 4.
• image field rotation is important in scanning microscopes, so that the position of the scan field can be ideally adapted to the sample structure of interest in rectangular image formats of widely differing edge lengths (i.e., the smallest possible scan field adapted to the sample structure of interest).
• This enables small scan fields, which ensure a sample-sparing and, above all, a fast image acquisition, since non-interest areas do not have to be scanned.
• a single cell fiber may be mentioned, for example a tubulin or actin fiber running diagonally through the sample.
• the advantage of using an optical image rotator is that the sample itself does not have to be moved, which increases the stability of the microscope. In particular, this avoids having to rotate the sample about an arbitrary axis, i. around the current image field center.
• the known field rotators have the disadvantage that they are comparatively large dimensions. Therefore, they are particularly suitable for use in
• the known field rotators have the disadvantage that they have a relatively complicated structure and high costs.
• One Another disadvantage of the known field rotators is that the
• Scanning beam for scanning the object and at the same time allows field rotation.
• a scanning device having the features of claim 1.
• Advantageous developments are specified in the dependent claims.
• a scanning device with the features of claim 1 an optimized beam path for a scanning beam for scanning the object and at the same time an image field rotation is possible, since at least one scanning unit and at least one rotating device are provided.
• the scanning unit is used for two-dimensional scanning of the object by means of a light beam.
• Rotation device is used to rotate the scanning unit about an axis of rotation to allow field rotation.
• the scanning unit comprises at least one deflection element for deflecting a light beam impinging on the deflection element.
• the deflection element has a rotationally symmetrical shape.
• the rotationally symmetrical shape is a circular shape.
• a preferred direction or a predetermined deflection angle of the scanning beam can be provided, which on the one hand is comparatively small and, on the other hand, greater than a maximum
• Scanning angle is.
• an optimized in terms of its dimensioning Beam path for the scanning beam reached.
• This allows in particular the use of the scanning device in miniaturized scanning microscopes.
• At the same time can be advantageous by a rotation of the scanning unit about the axis of rotation
• Image field rotation are generated.
• an optimized beam path for a scanning beam for scanning the object and at the same time an image field rotation can be realized.
• the axis of rotation about which the scanning unit is rotatable is perpendicular to a plane in which the scanning unit extends.
• a rotation of the scanning unit in a plane thereof can be achieved.
• the deflecting element is pivotable about a first pivot axis and / or about a second pivot axis corresponding to a maximum scanning angle.
• the first pivot axis and the second pivot axis extend parallel to a plane in which the scanning unit extends.
• a scanning beam for two-dimensional scanning of the object can be provided.
• the first pivot axis and the second pivot axis each extend through a center of the deflection element.
• the deflection element is gimbaled.
• the rotationally symmetrical shape refers to a center of the deflecting element.
• the axis of rotation about which the scanning unit is rotatable extends through this center of the deflection element.
• the scanning unit is rotatable about the axis of rotation at least in an angular range of 0 ° to 180 °. Upon rotation of the scanning unit in this angular range, the pivot axes can be brought into any rotational position between a horizontal rotational position and a vertical rotational position in order to achieve a complete scanning of the object.
• the deflecting element is a reflecting element for reflecting a light beam incident thereon.
• the deflection element is a reflecting element for reflecting a light beam incident thereon.
• the scanning unit preferably has an M EMS ("microelectromechanical systems”) scanner or a DMD ("deformable mirror device”) scanner.
• M EMS microelectromechanical systems
• DMD deformable mirror device
• Scanning unit i.e., scanner
• the MEMS scanner is a monolithic 2D scanner.
• a two-dimensional scanning of the object can be achieved with the aid of a single MEMS scanner.
• the rotation device comprises a gear arrangement which can be driven by means of a drive unit.
• the gear arrangement is designed to rotate the scanning unit about the axis of rotation.
• a reliable drive for rotation of the scanning unit about the rotation axis can be provided.
• Another aspect of the invention relates to a scanning microscope with an im
• Beam path of the scanning microscope arranged according to the invention Scanning device.
• the scanning device is a laser scanning microscope, preferably a confocal laser scanning microscope.
• the scanning unit is arranged such that the on the
• Ablenkelement incident light beam is deflected in a rest position of the scanning unit such that the deflected light beam and the impinging
• Light beam form a predetermined deflection angle.
• the predetermined deflection angle is greater than a maximum scanning angle to the two-dimensional
• the optimized, compared to the prior art, i. Minimized beam path for the scanning beam for scanning the object can be achieved.
• the predetermined deflection angle is less than or equal to 35 °, less than or equal to 30 °, less than or equal to 25 °, less than or equal to 20 °, less than or equal to 15 °, or less than or equal to 10 °.
• the preferred direction or the predetermined deflection angle of the scanning beam can be provided in different angular ranges.
• the maximum scanning angle is ⁇ 25 °, ⁇ 20 °, ⁇ 15 °, ⁇ 10 ° or ⁇ 5 °.
• the scanning microscope comprises an image acquisition unit for acquiring a digital image of the scanned object and an image processing unit for processing the digital image.
• the image processing unit for example, reflections and rotations of the digital image in the memory of a Calculator (PC) can be performed to any image position in one
• FIG. 1A shows a schematic representation of a scanning device with a scanning device
• Figure 1B is a schematic representation of the scanning device of Figure 1A with the
• Figure 2 is a schematic side view of a scanning microscope with the
• Figure 3 is a schematic diagram illustrating a reflection of a light beam on the scanning device of Figure 1A.
• Figure 4 is a schematic diagram illustrating a reflection of a laser beam to a 2D scanner according to the prior art.
• FIG. 1A shows a schematic representation of a scanning device 10 with a scanning unit 12 in a first rotational position according to an exemplary embodiment.
• the scanning device 10 of Figure 1A is used to scan an object 122 for the Use in a scanning microscope 100, as shown by way of example in FIG.
• the scanning device 10 comprises the scanning unit 12, which is arranged on a rotary device 14.
• the scanning unit 12 is used for two-dimensional scanning of the object 122 by means of a light beam.
• the rotary device 14 serves to rotate the scanning unit 12 by one
• Rotation axis 16 to generate an image field rotation. Furthermore, it is shown in FIG. 1A that the scanning unit 12 comprises a deflection element 18 which has a rotationally symmetrical shape. The deflection element 18 serves to deflect a light beam incident on the deflection element 18.
• a first rotational position of the scanning unit 12 is shown in particular. For example, this first rotational position corresponds to a rotational angle of 0 °.
• a rotation of the scanning unit 12 about the axis of rotation 16 is shown schematically in Figure 1A by the double arrow Ri.
• the deflector 18 has a circular shape.
• the rotary device 14 comprises a drive unit 30 with the aid of which a gear arrangement can be driven.
• the gear arrangement comprises a first gear 24 and a second gear 26.
• the first gear 24 is drivable by means of the drive unit 30.
• the second gear 26 is connected to the scanning unit 12 and is engaged with the first gear 24 such that when driving the first gear 24, the scanning unit 12 connected to the second gear 26 is rotated about the rotation axis 16.
• the axis of rotation 16 is perpendicular to a plane P in which the scanning unit 12 extends.
• the axis of rotation 16 passes through a center M of the deflection element 18. ssen this center M corresponds to a center of the Kreisfo
• the deflector 18 is pivotable about a first pivot axis 22A and about a second pivot axis 22B. With the aid of these pivot axes 22A, 22B, the deflecting element 18 can each be pivoted in accordance with a maximum scanning angle a s , as shown by way of example in FIG. Furthermore, it is shown in FIG. 1A that the two pivot axes 22A, 22B extend parallel to the plane P in which the scanning unit 12 extends. A pivoting of the deflecting element 18 about the respective pivot axis 22A, 22B is shown schematically in Figure 1A by the double arrows R 2 and R3.
• the scanning unit 12 includes a first frame 20A and a second frame 20B.
• the first frame 20A surrounds the second frame 20B.
• the second frame 20B is connected to the first frame 20a and rotatably mounted thereon about the second pivot axis 22B.
• the deflection element 18 is connected to the second frame 20B and is rotatably mounted thereon about the first pivot axis 22A.
• the scanning unit 12 comprises in particular a cardanic suspension for mounting the deflecting element 18. In this gimbal
• the two pivot axes 22A, 22B extend through the center M of the deflector 18th
• the deflector 18 is a reflective element for reflecting an impinging thereon
• the deflection element 18 is used in particular for polarization-maintaining reflection of the incident light beam (such as a load beam).
• the deflector 18 is a mirror with a circular mirror surface.
• the scanning unit 12 is provided with a cable 28 for
• FIG. 1B shows a schematic illustration of the scanning device 10 according to FIG. 1A with the scanning unit 12 in a second rotational position.
• this second rotational position corresponds to a rotational angle within an angular range of 0 ° to 180 °.
• the scanning unit 12 can also be rotated by means of the rotary device 14 by larger angles of rotation, for example greater than or equal to 180 °, or greater than or equal to 360 °.
• the rotation by the cable 28 connected to the scanning unit 12 should not be impaired.
• the rotational positions of the scanning unit 12 shown in FIGS. 1A and 1B can be obtained with the aid of the rotary device 14. These rotational positions are each assigned to different settings for the image field rotation.
• FIG. 2 shows a schematic side view of a scanning microscope 100 with the scanning device 10 according to FIG. 1A according to an exemplary embodiment.
• the scanning microscope 100 shown in FIG. 2 is in particular a confocal laser scanning microscope.
• the scanning device 10 is arranged in the beam path of the scanning microscope 100.
• the scanning microscope 100 includes a laser light source 102 that generates a scanning beam 104 for scanning the object 122.
• the object 122 is arranged on a stage 124.
• a beam splitter 108 is arranged between the scanning device 10 and the laser light source 102.
• lenses 106a, 106b are arranged, through which the scanning beam 104 extends.
• a mirror 116 is arranged, which arranged the scanning beam 104 in the direction of one above the stage 124 Lens 120 reflects.
• an imaging optics is formed, which is formed by lenses 118a, 118b. With the aid of this imaging optics, the scanning beam 104 is imaged onto a focal plane 121 of the objective 120.
• the detection beam 126 (such as fluorescence radiation) emanating from the scanned object 122 and running essentially counter to the scanning beam 104 is detected by means of a detector 132. In the direction of the detection beam 126 behind the beam splitter 108 is a
• Detection optics arranged, which is formed by lenses 128 a, 128 b and a pinhole 130. This detection optics serves to image the object 122 onto the detector 132.
• the scanning beam 104 comprises a first beam section 110 in the direction of the scanning beam 104 in front of the scanning device 10 and a second beam section 112 (or 114a, 114b) in the direction of the scanning beam 104 after the scanning device 10.
• the first beam section corresponds to this 110 a light beam incident on the deflection element 18 of the scanning unit 12, while the second beam section 112 or 114a, 114b corresponds to a deflected from the deflection element 18 of the scanning unit 12 light beam.
• the two-dimensional scanning of the object 122 carried out with the aid of the scanning unit 12 is shown schematically in FIG.
• the beam section 112 corresponds to a deflected in a rest position of the scanning unit 12 light beam, while the
• Beam sections 114a, 114b each corresponds to a deflected in a working position of the scanning unit 12 light beam. Further, the beam portion 112 has a preferential direction defined by a predetermined deflection angle ao (i.e., angle between the beam portions 110, 112) while the beam portion 112 has a preferred direction
• Beam sections 114a, 114b each have a direction defined by a maximum scan angle a s .
• the maximum scanning angle A s corresponds to a positive or negative rotation angle which is incident on the beam section 112 the preferred direction is related. Further details on the angles ao and a s are described below with reference to FIG.
• FIG. 3 shows a schematic diagram for illustrating a reflection of a
• the scanning unit 12 is arranged such that the beam portion 110 in a
• this predetermined deflection angle ao is in particular greater than a maximum scanning angle (ie, a s ) and preferably less than 45 °.
• the comparatively small deflection angle ao can be achieved with the aid of the rotationally symmetrical deflection element 18.
• the deflection element 18 is circular, the two half-axes 32, 34 of the corresponding circular shape are the same size.
• Scanning device for example, a first scanning unit for scanning the object one-dimensionally, a second scanning unit for scanning the object one-dimensionally, a first rotating device for rotating the first scanning unit, and a second rotating device for rotating the second scanning unit.
• the first rotation device and the second rotation device are designed to the first scanning unit and the second scanning unit to rotate such that their rotational movements are synchronized.
• Embodiments of the invention provide a purely optical, cost-effective field rotator in a miniaturized optical structure of a scanning laser microscope 100 by means of a 2D scanner 12.
• a field rotator known from the prior art, the inventive
• Field rotators are miniaturized and does not require a complex beam path.
• the polarization of the incident laser beam 104 is obtained with the aid of the field rotator according to the invention.
• the invention has the following advantages. It was recognized that the choice of a comparatively large deflection angle ao 'according to FIG. 4 is not necessary. In contrast, the optical scanning angle a s of the miniaturized 2D MEMS scanner 12, for example, less than ⁇ 20 °, preferably less than ⁇ 10 °, are selected. When choosing a reflection angle ao in scanner rest position that is only minimally greater than the maximum screen angle a s , such as less than 25 °, the projected laser beam 104 on the mirror surface has only a ratio of both half axes of the projected elliptical beam profile of about 1 ,1.
• the large semiaxis 32 'of the elliptical MEMS mirror 18' would have to be at an optimized, ie minimized size, only about 10% larger than the small semiaxis 34 '(see FIG. 4). It is in this case of no significant disadvantage, round, ie rotationally symmetric MEMS mirror 18 with equal lengths 32, 34 to use (see Figure 3). Such mirrors per se are also known and widely used in the prior art. It is thus possible, on the one hand, to use round mirrors and at the same time to keep the characteristics of the MEMS scanner (almost) ideal. This actually means a (nearly) minimized mirror size, minimized
• the invention makes use of a 2D scanner, preferably a miniaturized biaxial MEMS scanner 12.
• a 2D scanner preferably a miniaturized biaxial MEMS scanner 12.
• both scanning axes 22a, 22b are united in one element and tilt the same mirror 18 by a gimbal or almost gimbal suspension.
• Two separate scanning units for example consisting of two separate galvanometer scanners for the X and Y axes, are therefore no longer necessary.
• Rotation axis 16 which is perpendicular to the mirror plane P and this cuts centrally, to a field rotation of the microscope assembly, as shown schematically in Figure 2.
• Image field rotation leads to an azimuthal change in position of the
• Scan axes 22a, 22b in the mirror plane P For example, if the axis 22a is the fast scan axis and the image coordinate X is assigned, this is rotated. In the microscope setup, this scanning direction of the laser beam 104 is correspondingly rotated in the sample 122 while the sample 122 remains stationary. Particularly advantageous in the sense of an ideal scanning movement and image field rotation is when the axes 22a, 22b and 16 intersect at the center M of the mirror 18 (ie gimballed mirrors with an intersection of the axes 22a, 22b in the mirror center M). Instead of the gimbal, it is also possible that the axes 22a, 22b do not intersect at the center of the mirror M. However, the axis 16 should intersect the mirror 18 at or near the midpoint M of the mirror 18 to complete the operation of the scanner 12 in all rotational positions
• the image field rotation thus generated can not make 360 ° turns in the same direction as often as the cable 28 leads to signal transmission to the rotating scanner 12 and does not allow any number of revolutions. However, it is perfectly sufficient for achieving the desired effect when an image field rotation of 0 ° to 180 ° or from -90 ° to + 90 ° is realized. If desired, all other image layers in the digital representation (computer) can then be generated by a simple image processing, ie reflections and rotations of the digital image in the memory of the PC. All that is important is that each orientation of the scanning axes 22a, 22b can be achieved in the opto-mechanical structure. This is already given with a covered angle range of 180 °.
• Rotation position is then no longer defined.
• the unit used for scanning is d. H. the scanner 12, a monolithic 2D scanner that has a single mirror 18 in two
• the various rotation devices should then rotate synchronized with each other.
• other beam deflecting elements may be used instead of mirrors.
• These can be, for example, elements integrated in MEMS technology, such as lenses, lens systems or prisms, which have a
• DMD deformable mirror devices
• AOD acousto-optic deflectors
• Embodiments of the invention provide a 2D scanner which is disclosed in US Pat
• the angular range of the image field rotation is limited because of the cable feed, but this means no functional restriction.

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• Analytical Chemistry (AREA)
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• 2015
  • 2015-12-23 LU LU92924A patent/LU92924B1/de active IP Right Grant
• 2016
  • 2016-12-23 EP EP16826338.2A patent/EP3394655A1/de active Pending
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