JP2015184620A - Light splitting device and optical measurement device provided therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light splitting device that makes it possible to downsize the whole device and an optical measurement device provided with the same.SOLUTION: An optical measurement device 1 comprises: a microscope optical system 3 for forming an optical image on an image-forming face upon receiving light from a subject S; a relay lens 17 for relaying the pupil surface of the microscope optical system 3 upon receiving light from the image-forming face; a diffraction grating 15 for dividing light from the image-forming face into a 0'th order diffraction light L0 for generating the optical image of fluorescence occurring on the subject S and a first order diffraction light L1 for generating the optical image of excitation light; an image-forming optical element 21 having two optical axes A3, A2 each corresponding to the first order diffraction light L1 and 0'th order diffraction light L0, and forming each of the first order diffraction light L1 and 0'th order diffraction light L0 into an optical image G3 and an optical image G2; optical elements 19a, 19b for selecting the wavelength components of the first order diffraction light L1 and 0'th order diffraction light L0; and an image-capturing element 7 for capturing the images of the optical images G2, G3.

Description

  The present invention relates to a light splitting device used for observing light from a sample and an optical measuring device including the same.

  In the life science field, light such as fluorescence from a sample is divided according to wavelength, and an optical image obtained as a result of the division is captured. For example, in Patent Document 1 below, light reflected and scattered by a sample is combined with light from a light source and then guided to a detection system, and fluorescence emitted from the sample is branched and guided to another detection system. A scanning microscope is described which forms an optical path.

JP 2000-292705 A

  However, in the scanning microscope described in Patent Document 1, an optical element and a detection system for fluorescence observation and an optical element and a detection system for observation of light having a wavelength other than the fluorescence wavelength are separately provided. Tend to be complicated. Therefore, it is difficult to reduce the size of the entire apparatus.

  Therefore, the present invention has been made in view of such problems, and an object thereof is to provide an optical splitting device that facilitates downsizing of the entire device and an optical measurement device including the same.

  That is, in order to solve the above-described problem, a light splitting device according to an aspect of the present invention receives light from an imaging surface of an objective lens for observing an object and relays a pupil plane of the objective lens And a second light for generating a first light and a second light image for generating a first light image including a fluorescence wavelength component corresponding to the fluorescence generated in the object. A diffraction grating that divides the light into two light axes and two optical axes respectively corresponding to the first light and the second light, and the first light and the second light, respectively, An imaging optical element that forms an optical image and a second optical image, and a wavelength selection unit that selects a wavelength component of the second light are provided.

  Alternatively, an optical measurement device according to another aspect of the present invention includes an objective lens that receives light from an object and forms an optical image on an imaging surface, and an objective lens that receives light from the imaging surface. A first lens and a second light for generating a first light image including a fluorescence wavelength component corresponding to the fluorescence generated in the object from the relay lens that relays the pupil plane of A diffraction grating that divides into second light for generating an image, and two optical axes that respectively correspond to the first light and the second light, and the first light and the second light, The imaging optical element that forms the first light image and the second light image, the wavelength selection unit that selects the wavelength component of the second light, the first light image and the second light image, respectively. An image pickup device for picking up an optical image.

  In such a light splitting device or an optical measuring device, the pupil plane of the objective lens that images light from the object is relayed by the relay lens, and the light from the imaging surface of the objective lens is a diffraction grating. Is divided into first light for generating a first light image including a fluorescence wavelength component and second light for generating a second light image. Further, the first and second lights divided by the diffraction grating are respectively formed into first and second light images by the imaging optical element, and a desired wavelength component is selected for the second light. Is done. Such a configuration facilitates the common use of the optical element for dividing the light from the object and the imaging element for observing the light, and as a result, the entire apparatus can be easily downsized. The

  In the light splitting device or the optical measuring device, it is preferable that the wavelength selection unit selects a wavelength component of excitation light that causes fluorescence. In this case, the fluorescence emitted from the object and the excitation light can be observed at the same time, and the light image of the object is acquired by the excitation light at the same time that the fluorescence is detected. It becomes easy.

  It is also preferable that the diffraction grating is disposed between the imaging surface of the objective lens and the relay lens. By adopting such a configuration, it becomes easy to design to shorten the entire length of the optical system.

  Further, it is also preferable that the first light is 0th order diffracted light and the second light is nth order diffracted light (n is a positive or negative integer). In this way, by setting the 0th-order diffracted light to the fluorescence wavelength, the spread of the fluorescence image in the diffraction direction can be suppressed.

  Furthermore, it is also preferable that the optical axis of the imaging optical element at the portion where the 0th-order diffracted light is imaged is shifted from the optical axis of the relay lens. By adopting such a configuration, it is possible to obtain a good image in each of the 0th order diffracted light and the nth order diffracted light (n is a positive or negative integer) with a reasonable arrangement.

  It is also preferable that the optical system further includes an optical element disposed between the relay lens and the imaging optical element, and the relay lens relays the pupil plane of the objective lens with respect to the optical element. With this configuration, it is possible to observe an optical image that is freely adjusted by the optical element.

  It is also preferable that the wavelength selection unit is disposed between the relay lens and the imaging optical element, and the relay lens relays the pupil plane of the objective lens with respect to the wavelength selection unit. By so doing, it is possible to observe an optical image whose wavelength component is freely adjusted by the wavelength selector.

  It is also preferable that at least one of the diffraction grating, the relay lens, the wavelength selection unit, and the imaging optical element is inclined with respect to the optical axis of the objective lens. In this case, a good observation image can be obtained by correcting the curvature of field.

  The imaging optical element preferably includes a first lens that forms the first light on the first optical image and a second lens that forms the second light on the second optical image. It is. The imaging optical element is integrated with the first lens unit that forms the first light into the first optical image and the first lens unit that forms the second light into the second optical image. It is also preferable to have the second lens portion formed into a second shape. If such an imaging optical element is provided, the structure of the imaging optical element is simplified, and further miniaturization of the entire apparatus is facilitated.

  In the above light splitting device, it is preferable that the image pickup device is disposed in a state inclined with respect to the optical axis of the objective lens. In this case, a good observation image can be obtained by correcting the curvature of field.

  According to the present invention, it is possible to provide a light splitting device that facilitates downsizing of the entire device and an optical measuring device including the same.

It is a perspective view which shows the internal structure of the optical measuring device 1 of one Embodiment of this invention. FIG. 2A is a front view showing a detailed structure of the imaging optical element 21 in FIG. 1, and FIG. 2B is a side view showing a detailed structure of the imaging optical element 21 in FIG. It is a perspective view which shows the internal structure of 1 A of optical measuring devices of other embodiment of this invention. It is a perspective view which shows the internal structure of the optical measuring device 1B of other embodiment of this invention. (A) is a front view showing a detailed structure of an imaging optical element 21A according to a modification, and (b) is a side view showing a detailed structure of the imaging optical element 21A. (A) is a front view showing a detailed structure of an imaging optical element 21B according to a modification, and (b) is a side view showing a detailed structure of the imaging optical element 21B. It is a perspective view which shows the internal structure of 1 C of optical measuring devices of other embodiment of this invention.

  Embodiments of a light splitting device according to the present invention will be described below in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Each drawing is made for the purpose of explanation, and is drawn so as to particularly emphasize the target portion of the explanation. Therefore, the dimensional ratio of each member in the drawings does not necessarily match the actual one.

  FIG. 1 is a perspective view showing an internal configuration of an optical measurement device 1 according to an embodiment of the present invention. The optical measurement device 1 according to the present embodiment is an optical device for dividing observation light of a sample (object) and observing two divided light images.

  As shown in the figure, the optical measuring device 1 includes a sample holding member (not shown), an excitation light source (not shown), a microscope optical system 3, a light splitting device 5, and an image sensor 7. Yes. The microscope optical system 3 is an optical system that receives light from the object S and forms a light image G1 on an image forming surface, and is configured by an objective lens 9 and an image forming lens 11. The light splitting device 5 is an optical device that is attached to the microscope optical system 3, splits the light input from the microscope optical system 3, and focuses the split light on different positions on the light receiving surface 7 a of the image sensor 7. . The image sensor 7 is attached to the light splitting device 5 and picks up the light images G2 and G3 formed at different positions on the light receiving surface 7a by the light splitting device 5 to obtain the light images G2 and G3. Convert to electrical signal and output.

  More specifically, the light splitting device 5 includes a diaphragm member 13, a diffraction grating 15, a relay lens 17, optical elements (wavelength selection units) 19a and 19b, and an imaging optical element 21 arranged in this order. Yes. The aperture member 13 is disposed on the primary imaging surface of the microscope optical system 3 including the objective lens 9, and the size of the optical images G3 and G4 formed on the light receiving surface 7a of the image sensor 7 is such that the light receiving surface 7a. , The light incident from the object S via the microscope optical system 3 is narrowed down so as to be less than half the size of the light receiving surface 7a.

  The diffraction grating 15 is disposed between the primary imaging plane of the microscope optical system 3 and the relay lens 17. The diffraction grating 15 divides the light that has passed through the diaphragm member 13 into a plurality of divided lights by a diffraction phenomenon. The 0th-order diffracted light L0 and the 1st-order diffracted light L1 among the plurality of divided lights divided by the diffraction grating 15 pass on a later-described relay lens 17 and the imaging optical element 21, and thus on the light receiving surface 7 a of the image sensor 7. Is imaged. Both the 0th-order diffracted light L0 and the 1st-order diffracted light L1 divided by the diffraction grating 15 include a wavelength component corresponding to the fluorescence generated in the object S. Here, the combination of the divided lights to be imaged on the image sensor 7 may be other than the above combination. For example, a combination of 0th order diffracted light and nth order diffracted light (n is a positive or negative integer other than 0) may be used. Further, since the relay lens 17 receives a plurality of lights divided by the diffraction grating 15, there is an advantage that the design for shortening the optical system becomes easy.

  The relay lens 17 receives the light from the microscope optical system 3 through the diffraction grating 15 and refracts the 0th-order diffracted light L0 and the first-order diffracted light L1 divided by the diffraction grating 15, thereby the objective lens of the microscope optical system 3. The pupil plane corresponding to the divided light of 9 is relayed to optical elements 19b and 19a described later. The relay lens 17 may be formed of an aspheric lens, or may be configured by a combination of a plurality of lenses. The relay lens 17 may relay the divided light as a parallel light flux.

  The imaging optical element 21 is disposed between the relay lens 17 and the imaging element 7 and has two different optical axes A2 and A3 corresponding to the 0th-order diffracted light L0 and the 1st-order diffracted light L1 relayed by the relay lens 17, respectively. The zero-order diffracted light L0 and the first-order diffracted light L1 are formed on the light images G2 and G3 at different positions on the light receiving surface 7a, respectively. FIG. 2 shows a detailed structure of the imaging optical element 21, (a) is a front view of the objective lens 9 viewed from the direction along the optical axis A0, and (b) is a view of the objective lens 9. It is the side view seen from the direction perpendicular | vertical to optical axis A0. As shown in the figure, the imaging optical element 21 includes two imaging lenses 21 a and 21 b that are separated from each other in the direction along the light receiving surface 7 a of the imaging element 7. Each imaging lens 21a, 21b has two optical axes A3, A2 corresponding to the first-order diffracted light L1 and the 0th-order diffracted light L0, respectively. As described above, the imaging optical element 21 includes a plurality of lenses corresponding to a plurality of divided lights, so that the optical system can be easily adjusted, and the purpose is to shorten the optical system and improve the image characteristics. Design becomes easy. In the present embodiment, the two imaging lenses 21a and 21b are the same element, but they may be different elements. Further, the two imaging lenses 21a and 21b may be arranged so that their ends are in contact with each other. Here, the optical axis A2 of the image forming lens 21b that forms the 0th-order diffracted light L0 is set so as not to be coaxial with the optical axis A0 of the relay lens 17 and to deviate from the optical axis A0. By setting the optical axis A2 in this way, there is an advantage that a good image can be obtained for each of the 0th-order diffracted light L0 and the 1st-order diffracted light L1. The imaging optical element 21 may form a double-sided telecentric optical system in the light splitting device 5 together with the relay lens 17.

  The optical elements 19a and 19b are respectively arranged in the vicinity of the pupil plane related to the first-order diffracted light L1 and the 0th-order diffracted light L0 between the relay lens 17, the imaging lens 21a, and the imaging lens 21b. Each of the optical elements 19a and 19b is a wavelength selection filter that selects the wavelength components of the first-order diffracted light L1 and the 0th-order diffracted light L0, and is, for example, a band-pass filter, a low-pass filter, or a high-pass filter that transmits a desired wavelength. The optical element 19b is configured to receive the 0th-order diffracted light L0 and select a wavelength component including the fluorescence wavelength of the sample. The optical element 19a is configured to receive the first-order diffracted light L1 and select a wavelength component including the wavelength of the excitation light of the sample. In addition, since the 0th-order diffracted light L0 is a wavelength component including a fluorescence wavelength, the optical element 19b is not necessarily required.

  The imaging device 7 is a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal-Oxide Semiconductor) image sensor that converts the optical images G2 and G3 formed on the light receiving surface 7a by the imaging optical element 21 into electrical signals. And so on. The image sensor 7 may detect the light images G2 and G3 separately formed at different positions on the light receiving surface 7a, or may be formed at positions overlapping with each other within a range that does not interfere with detection. The optical images G2 and G3 may be detected.

  According to the optical measuring device 1 described above, the relay lens 17 relays the pupil plane of the microscope optical system 3 that forms an image of light from the object S including the fluorescence wavelength component, and also forms an image of the microscope optical system 3. The light from the surface is split by the diffraction grating 15 into 0th order diffracted light L0 and 1st order diffracted light L1. Further, the 0th-order diffracted light L0 divided by the diffraction grating 15 is selected as a wavelength component including the fluorescence wavelength by the optical element 19b, and is imaged on the optical image G2 by the imaging optical element 21. On the other hand, for the first-order diffracted light L1 divided by the diffraction grating 15, a wavelength component including the wavelength of the excitation light is selected by the optical element 19a, and is imaged on the optical image G3 by the imaging optical element 21. With such a configuration, the fluorescence emitted from the object S and the excitation light can be observed at the same time, so that the part of the object S in which the fluorescence is generated can be easily identified.

  Further, in the optical measuring device 1, the diffraction grating 15 is disposed between the imaging surface of the microscope optical system 3 and the relay lens 17. By allowing the relay lens 17 to receive the light divided by the diffraction grating 15, the pupil corresponding to the 0th-order diffracted light and the pupil corresponding to the nth-order diffracted light can be divided and relayed. Arrangement of certain optical elements 19a and 19b is facilitated. As a result, the design for shortening the entire length of the optical system becomes easy.

  Further, the optical measuring device 1 divides the fluorescence wavelength component of the light from the imaging plane into the 0th order diffracted light L0, and divides the excitation light wavelength component of the light into the nth order diffracted light (n is a positive or negative integer). . In this way, by setting the 0th-order diffracted light L0 to the fluorescence wavelength, the spread of the fluorescence image in the diffraction direction can be suppressed. Further, the excitation light component having a single wavelength is divided as the n-th order diffracted light, and the wavelength is selected by the optical element 19, so that the spread of the image in the diffraction direction can be suppressed even when the image is formed by the imaging lens. As a result, it is possible to acquire a highly accurate fluorescent image and object image.

  In addition, since the optical axis A2 of the imaging lens 21b in the portion where the 0th-order diffracted light is imaged is shifted from the optical axis A0 of the relay lens 17, it is possible to obtain a good image in each of the 0th-order diffracted light and the nth-order diffracted light. it can.

  In addition, this invention is not limited to embodiment mentioned above.

  For example, the optical measuring device 1 selects the wavelength component including the fluorescence wavelength from the 0th-order diffracted light divided by the diffraction grating 15 by the wavelength selection filter, while the excitation light from the first-order diffracted light divided by the diffraction grating 15. However, the present invention is not limited to such a configuration. For example, the wavelength component including the wavelength of the excitation light may be selected from the 0th-order diffracted light by the wavelength selection filter, while the wavelength component including the wavelength of the fluorescence may be selected from the 1st-order diffracted light. Further, the wavelength component selected by the optical element 19a is not limited to the wavelength component including the wavelength of the excitation light, and for example, the wavelength component including the fluorescence wavelength of the sample may be selected in the same manner as the optical element 19b. Other wavelength components may be selected. When fluorescence of a plurality of wavelengths is output from the sample, the optical element 19a selects a wavelength component including one fluorescence wavelength, and the optical element 19b selects a wavelength component including the other fluorescence wavelength. You may comprise. The light split by the diffraction grating 15 is not limited to the 0th order diffracted light and the nth order diffracted light, but is an nth order diffracted light and an mth order diffracted light (m is a positive or negative integer (however, excluding n)). There may be. Further, when the object S is irradiated with illumination light in a wavelength region that is neither the excitation light wavelength nor the fluorescence wavelength in addition to the excitation light, the optical measuring device 1 receives the scattered light or reflected light of the illumination light and receives the light. The light may be divided so that a light image of the light can be detected.

  Further, in the optical measurement device 1, the image sensor 7 may be disposed in a state of being inclined with respect to the optical axis A 0 of the objective lens 9 of the microscope optical system 3. FIG. 3 is a perspective view showing an internal configuration of an optical measurement device 1A according to another embodiment of the present invention. As shown in the figure, the image sensor 7 is disposed such that the light receiving surface 7a is inclined by an angle θ1 with respect to a surface perpendicular to the optical axis A0. Since the image plane of the n-th order diffracted light is inclined with respect to the image plane of the light incident on the light splitting device 5, the image plane is curved as the distance from the optical axis A0 of the incident light is increased. According to the configuration of the optical measurement device 1 </ b> A, the curvature of field can be reduced by arranging the image sensor 7 at an angle. As a result, good imaging characteristics can be obtained. In addition to the imaging element 7, any or all of the diffraction grating 15, the relay lens 17, the optical elements 19a and 19b, and the imaging optical element 21 may be arranged to be inclined with respect to the optical axis A0. Good. In this case, even better imaging characteristics can be obtained.

  Further, in the optical measurement devices 1 and 1A, the diffraction grating 15 may be arranged at different positions. FIG. 4 is a perspective view showing an internal configuration of an optical measurement device 1B according to another embodiment of the present invention. As shown in the figure, the diffraction grating 15 may be disposed between the relay lens 17 and the imaging optical element 21.

  Further, the configuration of the imaging optical element 21 may take various configurations other than the configuration shown in FIG. 5 and 6 respectively show the detailed structures of the imaging optical elements 21A and 21B according to the modified example of the present invention. Each of the imaging optical elements 21A and 21B has an optical image in which imaging lens portions having two different optical axes are integrally formed. That is, the imaging optical element 21A includes an imaging lens unit 21Aa that forms the first-order diffracted light L1 into the optical image G3, and an imaging lens unit 21Ab that forms the zero-order diffracted light L0 into the optical image G2. These imaging lens portions 21Aa and 21Ab are formed integrally at the end portions. The imaging optical element 21B includes an imaging lens unit 21Ba that forms the first-order diffracted light L1 into the optical image G3, and an imaging lens unit 21Bb that forms the zero-order diffracted light L0 into the optical image G2. The imaging lens unit 21Ba is integrally formed inside the imaging lens unit 21Bb. If such imaging optical elements 21A and 21B are provided, the structure of the imaging optical element is simplified, and further downsizing of the entire apparatus is facilitated. Although the imaging lens portions 21Aa and 21Ab in FIG. 5 are integrated at the ends, the imaging optical element 21A in FIG. 5 may be configured by contacting two imaging lenses. Good.

Further, although the optical elements 19a and 19b are configured to be wavelength selection units, various configurations can be adopted. For example, a wavelength selection unit 23 may be provided separately from the optical elements 19a and 19b as in an optical measurement device 1C according to another embodiment of the present invention illustrated in FIG. In the wavelength selection unit 23 in the figure, a wavelength selection filter 23a is disposed at a position for receiving light from the imaging lens 21a, and a wavelength selection filter 23b is disposed at a position for receiving light from the imaging lens 21b. The positions of the wavelength selection filters 23a and 23b are not limited to this, and may be disposed between the relay lens 17 and the optical elements 19a and 19b, or between the optical elements 19a and 19b and the imaging lenses 21a and 21b. . Further, when observing an optical image having the same wavelength component, it may be disposed between the diaphragm member 13 and the relay lens 17. Furthermore, the wavelength selection coating may be applied to the relay lens 17 and the imaging optical element 21, and a wavelength selection filter may be provided on the light receiving surface 7 a of the imaging element 7.
In these cases, the optical elements 19a and 19b can be optical elements other than the wavelength selection filter. For example, the polarization direction may be changed by configuring the optical elements 19a and 19b with polarizing plates, the luminous flux may be limited by configuring with a diaphragm member, or by configuring with lenses. The focal position may be changed.

  DESCRIPTION OF SYMBOLS 1,1A, 1B, 1C ... Optical measuring device, 3 ... Microscope optical system, 5 ... Light splitting device, 7 ... Imaging element, 7a ... Light-receiving surface, 9 ... Objective lens, 15 ... Diffraction grating, 17 ... Relay lens, 19a , 19b ... Optical element (wavelength selection unit) 21, 21A, 21B ... Imaging optical element, 21Aa, 21Ab, 21Ba, 21Bb ... Imaging lens unit, 21a, 21b ... Imaging lens, 23 ... Wavelength selection unit, 23a , 23b ... wavelength selection filter, A0, A2, A3 ... optical axis, G1, G2, G3 ... optical image, L0 ... 0th order diffracted light, L1 ... first order diffracted light, S ... object.

Claims (15)

A relay lens that receives light from the imaging surface of the objective lens for observing the object and relays the pupil plane of the objective lens;
A first light for generating a first light image and a second light image for generating a first light image including a fluorescence wavelength component corresponding to the fluorescence generated in the object from the light from the imaging plane. A diffraction grating that divides into two light beams;
The first light and the second light respectively have two optical axes corresponding to the first light and the second light, respectively, and the first light image and the second light, respectively. An imaging optical element that forms an optical image of 2;
A wavelength selection unit that selects a wavelength component of the second light;
A light splitting device. The wavelength selection unit selects a wavelength component of excitation light that causes the fluorescence.
The light splitting device according to claim 1. The diffraction grating is disposed between the imaging surface of the objective lens and the relay lens.
The light splitting device according to claim 1 or 2. The first light is zero-order diffracted light, and the second light is n-order diffracted light (n is a positive or negative integer).
The light splitting device according to claim 1. The optical axis of the imaging optical element of the portion that forms the 0th-order diffracted light is shifted from the optical axis of the relay lens,
The light splitting device according to claim 4. Further comprising an optical element disposed between the relay lens and the imaging optical element;
The relay lens relays the pupil plane of the objective lens to the optical element;
The light splitting device according to any one of claims 1 to 5. The wavelength selection unit is disposed between the relay lens and the imaging optical element, and the relay lens relays the pupil plane of the objective lens to the wavelength selection unit,
The light splitting device according to any one of claims 1 to 5. At least one of the diffraction grating, the relay lens, the wavelength selection unit, and the imaging optical element is tilted with respect to the optical axis of the objective lens,
The light splitting device according to claim 1. The imaging optical element includes a first lens that forms the first light on the first optical image and a second lens that forms the second light on the second optical image. Have
The light splitting device according to claim 1. The imaging optical element includes a first lens unit that forms the first light on the first optical image, and the first lens that forms the second light on the second optical image. A second lens unit integrated with the lens unit,
The light splitting device according to claim 1. An objective lens that receives light from the object and forms an optical image on the imaging surface;
A relay lens that receives light from the imaging plane and relays the pupil plane of the objective lens;
A first light for generating a first light image and a second light image for generating a first light image including a fluorescence wavelength component corresponding to the fluorescence generated in the object from the light from the imaging plane. A diffraction grating that divides into two light beams;
The first light and the second light respectively have two optical axes corresponding to the first light and the second light, respectively, and the first light image and the second light, respectively. An imaging optical element that forms an optical image of 2;
A wavelength selection unit that selects a wavelength component of the second light;
An image sensor that captures the first optical image and the second optical image;
An optical measurement device comprising: The wavelength selection unit selects a wavelength component of excitation light that causes the fluorescence.
The optical measurement device according to claim 11. The diffraction grating is disposed between the imaging surface of the objective lens and the relay lens.
The optical measuring device according to claim 11 or 12. The first light is zero-order diffracted light, and the second light is n-order diffracted light (n is a positive or negative integer).
The optical measuring device according to claim 11. The image sensor is disposed in a state inclined with respect to the optical axis of the objective lens.
The optical measuring device of any one of Claims 11-14.

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