DE102012205722B4 - Imaging color splitter module, microscope with such a color splitter module and method for imaging an object field in a first and a second image plane - Google Patents

Abstract

Imaging color splitter module with an imaging optics (4) having a first lens (2) and a second lens (3) for imaging an object field (5) into a first and a second image plane (6, 7) and a color splitter (10) which moves one of the Object field (5) up to the color splitter (10) common beam path (14) into a first beam path (15), which extends to the first image plane (6), and into a second beam path (16), which extends up to the second image plane (7 ), divided, the common beam path (14) and the first beam path (15) each running non-axially through the first lens (2) and the second beam path (16) running axially through the second lens (3).

Description

The present invention relates to an imaging color splitter module, a microscope with such a color splitter module and a method for imaging an object field in a first and a second image plane.

Such imaging color splitter modules are e.g. used in fluorescence microscopy of biological samples to simultaneously excite multi-colored samples and to observe or record two fluorescence images at the same time. For this purpose, monochrome cameras are preferably used so that a color division is carried out by means of a color divider module. Such a known color splitter module usually includes imaging optics and a 45 ° beam splitter and two emission filters, the beam splitter e.g. is arranged in a parallelized or a convergent beam path. As a result, the light strikes the beam splitter with a different angle spectrum for different points of the object field to be imaged. This means that both the beam splitter and the emission filter must be designed as dielectric elements, which lead to high costs for the color splitter module due to the high cost of such dielectric elements. Furthermore, the sensitivity is reduced by the finite efficiency of the dielectric elements and there are many interfering interfaces (of the three dielectric elements).

The properties of such a dielectric beam splitter are angle-dependent and have e.g. a [1-cos (a)] characteristic of the spectral properties as a function of the angle of incidence of light, which consequently leads to a spectrally inhomogeneous division over the field. Furthermore, the location of the transition between the reflection and transmission bands is generally different for the p and the s polarization. Since the light to be detected is mostly unpolarized in fluorescence applications, there is disadvantageously a spectral spread of the transition region.

The DE 10 2006 056 429 B3 describes a laser microscope with a spatially separating beam splitter and the US 2009/0316258 A1 describes a microscope with a color divider.

Based on this, it is an object of the invention to provide an imaging color divider module with improved properties. Furthermore, an improved method for spectrally selective imaging of an object field in a first and a second image plane is to be made available.

The object is achieved by an imaging color splitter module with an imaging optics having a first and a second lens for imaging an object field in a first and a second image plane and a color splitter which converts a common beam path extending from the object field to the color splitter into a first beam path which extends to runs to the first image plane, and divides into a second beam path that extends to the second image plane, the common beam path and the first beam path each running off-axis through the first lens and the second beam path running off-axis through the second lens.

An off-axis passage through the first or second lens is understood here in particular to mean that the corresponding beam path is not symmetrical to the optical axis of the imaging optics or that the corresponding beam path is adjacent to or spaced from the optical axis so that the optical axis ( in the area of the corresponding lens) is not in the corresponding beam path. The beam path is understood here in particular to mean that this is the area in which the light propagates when the intended imaging is intended.

The imaging color splitter module according to the invention is also referred to below as an imaging spectral multi-channel system.

The color splitter can be a special dielectric filter that combines the functionalities of a color splitter and an emission filter in a single element due to its special arrangement in the beam path and design. This is referred to below as a combination filter.

In the color splitter module according to the invention, the color splitter can thus advantageously combine the properties of a color splitter and an emission filter (preferably for the second beam path).

A spectrally selective imaging of the object field into the first and second image planes can thus be carried out with the imaging optics, the spectral splitting being carried out by means of the color splitter or the combination filter, so that no additional beam splitter, as in conventional color splitter modules, is necessary. The color splitter module according to the invention can therefore also be referred to as a beam splitter-free color splitter module or a beam splitter-free multi-channel system.

The imaging optics can in particular be designed as 1: 1 imaging optics.

The imaging optics can have a pupil and the color divider is preferably in the pupil arranged. In particular, the color divider is arranged in the pupil between the two lenses.

In the color splitter module according to the invention, the color splitter can cause reflection for the first beam path and transmission for the second beam path.

The imaging optics can preferably be designed as telecentric 4f imaging optics.

A further color filter is preferably arranged between the first lens and the first image plane. Furthermore, a further color filter can be arranged between the second lens and the second image plane.

The color filter or combination filter and / or the further color filter or the further combination filter can in particular be designed as an interference filter and / or as an emission filter.

Furthermore, the color divider can be provided interchangeably in the imaging color divider module.

The imaging color splitter module can be designed as a camera adapter, so that the first and second images can be recorded simultaneously. This can be done by one or two cameras.

In the color splitter module according to the invention, a second imaging color splitter module can be provided, which has a second imaging optics having a third lens for imaging a further object field in a third and fourth image plane and a further color splitter, which extends a further common beam path running from the further object field into a third beam path. which extends to the third image plane, and divides into a fourth beam path which extends to the fourth image plane, the further common beam path and the third beam path running through the third lens, and either a) the further object field with the first or second image plane coincides or is mapped onto this or b) the object field coincides with the third or fourth image plane or is mapped onto this.

An intermediate imaging optics can be provided between the two color splitter modules.

The second color splitter module can be designed and developed in the same way as the color splitter module according to the invention. Furthermore, it is possible that, in the second color splitter module, the further color splitter is followed by a reflective element which causes the fourth beam path to fold, so that the fourth beam path runs through the further color splitter and the third lens. In this case, the second imaging optics preferably comprises only the third lens. Furthermore, the further color splitter and the reflective element are preferably arranged such that after the beam path folding caused by both elements, the third and fourth beam paths do not coincide, but e.g. include a predetermined angle.

In particular, at least a third color splitter can be arranged between the further color splitter and the reflective element, which causes a further beam path folding for a fifth beam path (or further beam paths) for a predetermined wave range, which does not coincide with the third or the fourth beam path . In this way, the object field can be spectrally selectively imaged in five or more image planes by means of the color splitter module according to the invention.

In the second color divider module, the third and fourth image planes can also coincide.

In general, more than two color splitter modules (according to the invention) can also be connected in series. Of course, an intermediate image can also be used for this, which maps the image into the object field of the respective color divider module.

Furthermore, the color splitter module according to the invention can be used in a microscope. In particular, a microscope, in particular a light scanning microscope or a laser scanning microscope, is thus also provided with an ink splitter module according to the invention.

The object is further achieved by a method for spectrally selective imaging of an object field in a first and a second image plane with an imaging optics having a first and a second lens and a color splitter, in which a common beam path extending from the object field to the color splitter in is used by the color splitter a first beam path, which extends to the first image plane, and is divided into a second beam path, which extends to the second image plane, such that both the common beam path and the first beam path each run off-axis through the first lens and the second beam path off-axis runs through the second lens.

The method according to the invention can be developed in the same way as the color divider module according to the invention.

It goes without saying that the features mentioned above and those yet to be explained not only in the combinations indicated, but also in other combinations or in Can be used alone without leaving the scope of the present invention.

• 1 eine schematische Ansicht einer ersten Ausführungsform des erfindungsgemäßen Farbteilermoduls 1;
• 2 eine schematische Draufsicht der Linse 2 von 1;
• 3 eine schematische Detailansicht zur Erläuterung der Abbildung des Objektfeldes 5 in die erste Bildebene 6;
• 4 schematisch die Kombination mehrerer Farbteilermodule,
• 5 eine schematische Ansicht einer Ausführungsform eines weiteren Farbteilermoduls 1';
• 6 eine weitere Ansicht zur Erläuterung der Ausführungsform gemäß 5;
• 7 eine Draufsicht der Linse 2' der Ausführungsform gemäß 5 und 6;
• 8 eine Ansicht zur Erläuterung der Abbildung des Objektfeldes in die erste Bildebene bei der Ausführungsform gemäß 5 bis 7;
• 9 eine Ansicht zur Erläuterung einer Abwandlung der Ausführungsform gemäß 5-8;
• 10-14 verschiedene Möglichkeiten der Ausbildung der Farbfilter 10 bzw. 10' und 13 bzw. 13', und
• 15 eine schematische Darstellung eines Mikroskops mit einem erfindungsgemäßen Farbteilermodul.

The invention is explained in more detail below, for example with reference to the accompanying drawings, which also disclose features essential to the invention. Show it:

• 1 is a schematic view of a first embodiment of the color divider module according to the invention 1 ;
• 2nd a schematic plan view of the lens 2nd from 1 ;
• 3rd a schematic detailed view to explain the mapping of the object field 5 in the first image plane 6 ;
• 4th schematically the combination of several color divider modules,
• 5 is a schematic view of an embodiment of a further color divider module 1';
• 6 another view to explain the embodiment according to 5 ;
• 7 a top view of the lens 2 ' according to the embodiment 5 and 6 ;
• 8th a view for explaining the mapping of the object field in the first image plane in the embodiment according to 5 to 7 ;
• 9 a view for explaining a modification of the embodiment according to 5-8 ;
• 10-14 different ways of forming the color filter 10th or. 10 ' and 13 or. 13 ' , and
• 15 a schematic representation of a microscope with a color divider module according to the invention.

At the in 1 The embodiment shown comprises the imaging color divider module according to the invention 1 a first and second lens 2nd , 3rd that have an imaging optics 4th form.

The imaging optics 4th is designed to be an object field 5 , which can be an intermediate image of a microscopic image, for example, in a first image plane 6 as well as a second image layer 7 maps.

The first and second lens 2nd , 3rd each have the same focal length f and lie on a common optical axis 8th . The distance between the two lenses 2nd , 3rd is 2f . The distance of the object field or the plane in which the object field 5 lies to the first lens 2nd is f. The distance between the first image plane is the same 6 and the first lens 2nd again f and also the distance between the second lens 3rd and the second image plane 7 is f. The imaging optics 4th is therefore designed as a 1: 1 imaging optics and can also be called a telecentric 4f imaging optics.

The imaging optics 4th points between the two lenses 2nd , 3rd a pupil 9 on in which a first color filter 10th is arranged, which transmits light of a predetermined wavelength range and reflects light outside the predetermined wavelength range. Furthermore, in the pupil 9 another aperture 11 intended.

As in 1 is indicated, the light of the object field runs 5 off-axis through the first lens 2nd and meets the first color filter 10th . This color filter 10th can be, in particular, a special dielectric filter which combines the functionalities of a color splitter and an emission filter in a single element due to its special arrangement in the beam path and design. This is referred to below as a combination filter. That from the first color filter 10th reflected light with a wavelength outside the predetermined wavelength range thus passes through the first lens again 2nd , meets a deflecting mirror 12th , runs through a second color filter 13 and then hits the first image layer 6 . The second color filter 13 is designed so that it only transmits light of a first wavelength range that is different from the predetermined wavelength range (hereinafter also referred to as the second wavelength range).

That from the first color filter 10th transmitted light hits the second lens 3rd off-axis and is from this to the second image plane 7 pictured.

The color divider module according to the invention 1 thus has a common beam path 14 on that of the object field 5 through the first lens 2nd up to the first color filter 10th running. In this common beam path 14 Both light of the first wavelength range and light of the second wavelength range are contained. The first color filter 10th In addition to its property as a color filter, it now also serves as a divider that shares the common beam path 14 in a first beam path 15 from the first color filter 10th over the first lens 2nd , the deflecting mirror 12th , the second color filter 13 up to the first image level 6 runs, and in a second beam path 16 from the first color filter 10th over the second lens 3rd up to the second image level 7 runs, divides.

Thus the object field 5 both in the first and in the second image plane 6 , 7 mapped, with the image in the first image plane 6 there is a folded beam path and the first lens 2nd is run through twice and in the image in the second image plane 7 there is no folded beam path and the first lens 2nd as well as the second lens 3rd going through exactly once. This is particularly possible because the first and second lenses 2nd , 3rd each run off-axis, as in 1 is shown. The optical structure of the color divider module 1 can therefore be described as a laterally asymmetrical, telecentric structure.

With the color divider module according to the invention 1 can thus the object field 5 as the first picture 17th only with light of the first wavelength range in the first image plane 6 and as a second picture 18th only with light of the second wavelength range in the second image plane 7 be mapped.

In 2nd is a top view of the first lens 2nd shown, schematically showing the passage areas for the object field 5 and the first picture 17th and thus for the common beam path 14 and the first ray path 15 are drawn. As can be seen from this illustration, the beam paths go 14 and 15 off-axis through the first lens. The second beam path 16 goes off-axis through the second lens 3rd , as in 1 is shown.

In 3rd is only the common beam path 14 as well as the first beam path 15 drawn in to the imaging property of the imaging optics 4th to clarify.

In the color divider module according to the invention 1 Compared to conventional color splitter modules, no additional beam splitter is necessary in addition to the two color filters, since the first color filter 10th in the color divider module according to the invention 1 also serves as a beam splitter. The number of components can thus be reduced, which means that the color splitter module according to the invention can be produced more cost-effectively 1 enables. The color divider module according to the invention thus has 1 also fewer surfaces, so that fewer losses occur.

Because the first color filter 10th in the parallel beam path between the two lenses 2nd and 3rd there is no increased susceptibility to astigmatism. After the angle of incidence on the two color filters 10th and 13 The color filters can be smaller than 45 ° or much smaller than 45 ° 10th , 13 have steeper spectral edges due to less polarization splitting of the transition regions. Furthermore, there is less angular dependence of the spectral division properties, so that a spectrally constant division over the image field is possible.

It is also possible to use two color splitter modules 1 and 1' according to 1 to 3rd arrange so that the first image 17th in the first image plane 6 of the first color divider module 1 according to 1 to 3rd then the object field for the second color splitter module 1' according to 1 to 3rd is like in 4th is shown schematically. In the same way, the second image can additionally or alternatively 18th of the color divider module 1 as an object field of another color splitter module 1' according to 1 to 3rd serve. The order of the color divider modules 1 , 1' can of course also be turned over so that a color divider module 1 a color divider module 1' is subordinate.

The following are further possible designs of a further color divider module 1' described.

In 5 to 8th is a possible embodiment of a further color divider module 1' shown that according to the training 1 to 3rd is similar. The main difference is that the imaging optics 4 ' just a single lens 2 ' has both the common beam path 14 ' as well as from the first and second beam path 15 ' and 16 ' is going through. Due to the similar design, similar elements are designated with reference numerals, which are only identified with the character 'to distinguish them.

How best 5 can be seen, passes through the common beam path 14 ' the first lens 2 ' off-axis and meets the first color filter 10 ' which is now with the optical axis 8th' encloses an angle of not equal to 90 °, behind the first color filter 10th a mirror tilted in opposite directions 19 ' is arranged ( 6 ). There is also a second deflecting mirror 20 ' for the second beam path 16 ' intended.

By tilting the first color filter 10 ' is achieved that the first beam path 15 ' when passing through the first lens 20 ' in both the x and y directions to the common beam path 14 ' when passing through the first lens 2 ' is staggered.

If you look at the lens 2 ' in four imaginary quadrants 21 , 22 , 23 and 24th divides as in 7 the common beam path is shown 14 ' in the quadrants 22 ' and 23 ' and lies the first ray path 15 ' in the quadrant 24 ' .

That from the first color filter 10 ' transmitted light (i.e. light of the second wavelength range) hits the mirror 19 ' , is reflected on it and runs through the first color filter again 10 ' in such a direction that the second beam path 16 ' the first lens 2 ' in the quadrant 21 ' penetrates ( 7 ). This is the second beam path 16 ' in the lens 2 ' to the common beam path 14 ' offset in both the x and y directions. The offset in the x direction is the same as for the first beam path 15 ' . The offset in the y direction is equal to the absolute amount, but in the opposite Direction compared to the first beam path 15 ' , as in 7 can be seen.

In 8th is again the beam path for imaging in the first image plane 6 ' in the same way as in 3rd shown.

In the embodiment according to 6 to 8th is therefore a telecentric structure with only a single lens 2 ' before, being to the object field 5 ' there is a lateral displacement. This enables a very compact design to be achieved. Furthermore, correction errors of the first lens are raised 2 ' due to the double passage for the image in the first as well as in the second image plane 6 ' , 7 ' on. Different imaging ratios can also be caused by focal length tolerances of the lenses, which in the embodiment according to FIG 1 to 3rd can occur can be avoided.

In addition to the first color filter, for example, another color filter with a slightly different tilt between the color filter 10 ' and the mirror 19 ' be arranged so that there is a cascading of several tilted color filters. This allows the embodiment according to 6 to 8th can be expanded to more than two channels.

A modification of the embodiment according to 5 to 8th will be used in conjunction with 9 explained, the representation in 9 the representation in 6 corresponds. This modification differs from the embodiment according to 5 to 8th essentially only in that the first color filter 10 ' as a mirrored color filter 10 ' is formed with a defined wedge-angled substrate and thus monolithic. Otherwise, the structure is the same as in the embodiment according to 5 to 8th , so that on the corresponding description of the 5 to 8th can be referred.

The color splitter module according to the invention can be designed, for example, as a camera adapter. For example, in the first and second image level 6 , 7 Cameras (not shown) can be provided to view the spectrally different images 17th , 18th to record.

The color divider modules 1' according to 5 - 8th and 9 can also be designed so that the two spectrally different images 17 ' , 18 ' can be recorded with a single camera chip. For example, the two mirrors 12 ' and 20 ' be omitted so that the first and second image plane 6 ' , 7 ' coincide and lie in the xy plane, causing the first and second images in the xy plane 17 ' , 18 ' lie side by side in the y direction. A correspondingly arranged camera chip 38 ' is schematically in 5 and 8th and the corresponding beam path is shown in dashed lines. Of course, it is also possible with this variant, an intermediate image of the image planes 6 ' and 7 ' into the camera chip 38 ' perform.

The color filters 10th , 13 or. 10 ' , 13 ' are in particular interference filters or emission filters. They can each be designed as long, band or short pass filters.

Furthermore, the color filter 10th , 13 or. 10 ' , 13 ' interchangeable and / or provided with changeable filter properties. For example, a rotating filter wheel 25th ( 10th ) with several different filters 26 , 27 , 28 , 29 be provided, with one of the filters in the working position as the first color filter always by rotating the filter wheel 10th or. 10 ' or second color filter 13 or. 13 ' can be brought and the arrow P1 in the direction of the incident light.

Furthermore, two filter wheels 30th , 31 be arranged one behind the other, as in 11 is indicated. One of the two filter wheels 30th , 31 can with several different long pass filters and the other of the two filter wheels 30th , 31 can be equipped with several different short pass filters. The filter wheels 30th and 31 can be rotated in such a way that one of the filters can be brought into the working position, so that an adjustable bandpass filter is provided by a combination of the filters then arranged one behind the other.

Of course, no filter wheels have to be provided. For example, a linear long-pass filter 32 in front of a linearly extending short pass filter 33 be arranged relative to each other (double arrow P2 ) can be moved so that an adjustable bandpass filter is available ( 12th ).

It is also possible to use a linearly extending segment filter 34 with multiple segments 35 to provide ( 13 ), which each have predetermined filter properties (eg long, band or short pass filters). By positioning the corresponding segment 35 the desired filter property can then be achieved.

In 14 is a linear gradient filter 36 provided the as by the double arrow P2 is indicated, can be moved and thus a predetermined section in the work area by the bracket 37 is indicated, is brought.

The described displacements or rotations can be done either manually or by motor.

In 15 is the color divider according to the invention 1 designed as a dual camera adapter, with the color divider 1 two cameras 39 and 40 to take the first and second picture 17th , 18th are attached. The color divider module 1 with the two cameras 39 and 40 is used for microscopic observation of a multi-colored sample 41 with simultaneous excitation by means of a lighting module 42 . For this purpose, the entire device is designed as a microscope and has a main divider 43 as well as a lens 44 on.

The use of the color divider module according to the invention thus provides a microscope in which two color channels can be detected simultaneously. This avoids image artifacts caused by sample movement and / or changes during the otherwise usual color channel change. The load, in particular of rapidly bleaching or phototoxically sensitive samples (in particular living cells) can also be reduced. Furthermore, the simultaneous detection of two color channels can halve the duration of the experiment, which is particularly important in the case of data-intensive microscopy techniques.

Furthermore, sensitive, monochrome cameras can be used 39 and 40 be used.

The representation of the microscope in 15 is to be understood purely as an example. In particular, the microscope can be designed as a light scanning microscope (for example a laser scanning microscope). It also becomes a microscope with the color splitter module according to the invention 1 disclosed.

Claims (9)

Color divider module with an imaging optics (4) having a first lens (2) and a second lens (3) for imaging an object field (5) into a first and a second image plane (6, 7) and a color splitter (10) which detects one from the object field ( 5) up to the color splitter (10) common beam path (14) into a first beam path (15), which extends to the first image plane (6), and into a second beam path (16), which extends up to the second image plane (7) splits wherein the common beam path (14) and the first beam path (15) each run off-axis through the first lens (2) and the second beam path (16) runs off-axis through the second lens (3). Color divider module after Claim 1 , in which the imaging optics (4) are designed as 1: 1 imaging optics. Color divider module after Claim 1 or 2nd , in which the imaging optics (4) have a pupil (9) and the color divider (10) is arranged in the pupil (9). Color splitter module according to one of the above claims, in which the color splitter (10) causes reflection for the first beam path (15) and transmission for the second beam path (16). Color splitter module according to one of the above claims, in which the imaging optics (4) are designed as telecentric 4f imaging optics. Color divider module according to one of the above claims, in which a further color filter (13) is arranged between the first lens (2) and the first image plane (6). Color splitter module according to one of the above claims, in which a second color splitter module (1 ') is provided which has a second imaging optics (4') having a third lens (2 ') for imaging a further object field in a third and fourth image plane (6', 7 ') and a further color splitter (10') which converts a further common beam path (14 ') from the further object field into a third beam path (15') which extends to the third image plane (6 ') and into a fourth Beam path (16 '), which extends to the fourth image plane (7'), divides, the further common beam path (14 ') and the third beam path running through the third lens (2') and wherein either a) the further object field coincides with the first or second image plane or is mapped onto this or b) the object field (5) coincides with the third or fourth image plane (6 ', 7') or is imaged on this. Microscope, in particular light scanning microscope, with a color splitter module according to one of the above claims. Method for imaging an object field in a first and a second image plane with an imaging optic having a first and a second lens and a color splitter, in which the color splitter is used to run a common beam path from the object field to the color splitter into a first beam path that extends to the first image plane runs, and is divided into a second beam path, which extends to the second image plane, such that both the common beam path and the first beam path each run off-axis through the first lens and the second beam path runs off-axis through the second lens.

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