JP5022274B2 - Observation device - Google Patents

Description

  The present invention relates to an apparatus for observing a phase image of an inspection object.

A technique described in Non-Patent Document 1 is known as a technique for observing a phase image of an inspection object. The technique described in this document splits light into inspection light and reference light, causes inspection light that has passed through the inspection object and reference light to interfere with each other, and forms interference light. And the phase image of the inspection object is observed by analyzing the interference fringe image.
Mitsuo Takeda, Hideki Ina and Seiji Kobayashi, “Fourier-transformmethod of fringe-pattern analysis for computer-based topography and interferometry”, J. Opt. Soc. Am., Vol.72, No.1, pp.156-160 (1982 ).

  The technique described in Non-Patent Document 1 acquires the entire interference fringe image of the interference light incident on the imaging surface of the imaging unit, performs a nonlinear operation on the entire interference fringe image, and performs inspection. Since a phase image of an object is obtained, processing takes a long time. Therefore, when this technique is used, there is a limit in speeding up the flow of the phase image of the inspection object contained in the fluid flowing through the flow cell. For example, considering the case where cancer cells are identified based on the phase image of the cells contained in the blood flowing through the flow cell and the cancer cells are removed or collected, human blood (about approx. It takes a long time to process all of 5000 mL), which is not realistic.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide an observation apparatus capable of observing a phase image of an inspection object contained in a fluid flowing through a flow cell with high throughput. And

  The observation apparatus according to the present invention includes (1) a flow cell for flowing a fluid containing an inspection object, (2) a light source unit that outputs light, and (3) an inspection light that is divided into two light beams output from the light source unit. And (4) an inspection optical system for guiding the inspection light so that the optical path of the inspection light output from the branching section intersects the flow of fluid in the flow cell, and (5) output from the branching section. (6) Interference between the inspection light guided by the inspection optical system and the reference light guided by the reference optical system, and crossing in the direction of fluid flow in the flow cell An interference unit that generates fringes and outputs the interference light; and (7) an interference fringe that acquires an image of interference light in a limited range in a direction orthogonal to the interference fringes among the interference light output from the interference unit. A flow cell in an image obtained by an acquisition unit and (8) an interference fringe acquisition unit A one-dimensional spatial Fourier transform is performed on the intensity distribution of the interference fringes in the second direction orthogonal to the first direction at each position in the first direction orthogonal to the fluid flow direction in And an analysis unit for obtaining a phase image of the inspection object contained in the flowing fluid.

  In this observation apparatus, the light output from the light source unit is branched into two by the branching unit and output as inspection light and reference light. The inspection light output from the branching portion is guided by the inspection optical system, and the optical path of the inspection optical system intersects with the flow of fluid in the flow cell. The reference light output from the branching unit is guided by the reference optical system. The inspection light guided by the inspection optical system and the reference light guided by the reference optical system are caused to interfere with each other by the interference unit, and the interference light is output from the interference unit. In this interference light, an interference fringe crossing in the direction of fluid flow in the flow cell is generated. The interference fringe acquisition unit acquires an image of interference light in a range limited in the direction orthogonal to the interference fringes out of the interference light output from the interference unit. Then, the intensity of the interference fringes in the second direction orthogonal to the first direction at each position in the first direction orthogonal to the fluid flow direction in the flow cell in the image obtained by the interference fringe acquisition unit by the analysis unit. A one-dimensional spatial Fourier transform is performed on the distribution to obtain a phase image of the inspection object contained in the fluid flowing through the flow cell.

  In the observation apparatus according to the present invention, the light source unit outputs light having a coherence length shorter than 10 times the output wavelength, and the interference fringe acquisition unit displays an image of interference light in a range limited according to the coherence length. It is preferable to acquire. Alternatively, the interference fringe acquisition unit may: (a) a filter that selectively transmits interference light in a limited range in a direction orthogonal to the interference fringe among interference light output from the interference unit; and (b) It is also preferable to include an imaging unit that captures an image of the transmitted interference light. Alternatively, the interference fringe acquisition unit includes (a) an imaging unit that captures an image of interference light output from the interference unit, and (b) processes an image obtained by imaging by the imaging unit to obtain an interference fringe. And an image processing unit that acquires an image of interference light in a limited range with respect to the orthogonal direction. In the observation apparatus according to the present invention, it is preferable that the interference fringe acquisition unit includes an imaging unit having an imaging surface in which a plurality of pixels are two-dimensionally arranged in the first direction and the second direction.

  According to the present invention, the phase image of the inspection object contained in the fluid flowing through the flow cell can be observed with high throughput.

  The best mode for carrying out 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.

  (First embodiment)

First, a first embodiment of an observation apparatus according to the present invention will be described. FIG. 1 is a configuration diagram of an observation apparatus 1A according to the first embodiment. Observation apparatus 1A shown in this figure, the light source unit 10, imaging unit 20, the analyzing unit 30, a display unit 40, the flow cell 90, half mirror _HM 11, _{HM 12,} the lens _L 11 _{~L 15} and the mirror _{M 11, M 12} Is provided. This observation apparatus 1 </ b> A has a Mach-Zehnder interferometer optical system between the half mirror HM ₁₁ and the half mirror HM ₁₂ .

The light source unit 10 outputs white light having a short coherence length, and is, for example, a halogen lamp. The coherence length of the light output from the light source unit 10 is shorter than 10 times the output wavelength. The lens L ₁₁ collimates the light output from the light source unit 10 and outputs the collimated light to the half mirror HM ₁₁ . Half mirror HM ₁₁ acts as a bifurcation of the light collimated by the lens L ₁₁ is outputted from the light source unit 10 2 branches and outputs as the inspection light and the reference light.

The light (inspection light) reflected by the half mirror HM ₁₁ is reflected by the mirror M ₁₁ and is input to the half mirror HM ₁₂ through the lens L ₁₂ and the objective lens L ₁₃ . The mirror M ₁₁ , the lens L ₁₂ and the objective lens L ₁₃ constitute an inspection optical system that guides inspection light. The optical path of the inspection light between the lens L ₁₂ and the objective lens L ₁₃ intersects the fluid flow in the flow cell 90.

The light (reference light) transmitted by the half mirror HM ₁₁ passes through the lens L ₁₄ and the objective lens L ₁₅ , is reflected by the mirror M ₁₂ , and is input to the half mirror HM ₁₂ . The lens L ₁₄ , the objective lens L ₁₅ and the mirror M ₁₂ constitute a reference optical system that guides reference light. This reference optical system is an optical system equivalent to that obtained by removing the flow cell 90 from the inspection optical system, and has the same optical path length.

The half mirror HM ₁₂ causes the inspection light guided by the inspection optical system and the reference light guided by the reference optical system to interfere with each other, thereby generating interference fringes crossing in the direction of fluid flow in the flow cell 90. The interference light is output to the imaging unit 20 and acts as an interference unit.

The imaging unit 20 functions as an interference fringe acquisition unit that acquires an image of interference light in a range limited in a direction orthogonal to the interference fringe among the interference light output from the half mirror HM ₁₂ . In the present embodiment, since the coherence length of light output from the light source unit 10 is short, an image of interference light in a range limited according to the coherence length is acquired by the imaging unit 20.

  For each position in the first direction orthogonal to the direction of fluid flow in the flow cell 90 in the image obtained by the imaging unit 20, the analysis unit 30 calculates the intensity distribution of the interference fringes in the second direction orthogonal to the first direction. Is subjected to a one-dimensional spatial Fourier transform to obtain a phase image of the inspection object contained in the fluid flowing through the flow cell 90. The processing in the analysis unit 30 will be described in detail later. The display unit 40 displays the phase image obtained by the analysis unit 30 and performs input / output necessary for the operation of the observation apparatus 1A.

Figure 2 is a perspective view of the objective lens L ₁₃ and the flow cell 90 included in the observation apparatus 1A according to the first embodiment. FIG. 3 is a side view of the lens L ₁₂ , the objective lens L ₁₃ and the flow cell 90 included in the observation apparatus 1A according to the first embodiment. The fluid 91 flowing through the flow cell 90 includes an inspection object 92. For example, the fluid 91 is blood, and the test object 92 is red blood cells, white blood cells, cancer cells, and the like.

As shown in FIG. 3, the principal ray of the inspection light between the lens L ₁₂ and the objective lens L ₁₃ is inclined with respect to the lens L ₁₂ and the objective lens L ₁₃ of each optical axis. Lens _{L 12} and the principal ray, the lens _{L 12} and the objective lens _{L 13} the optical axes of the inspection light between the objective lens _{L 13,} and, the direction of flow of the fluid 91 in the flow cell 90, a common plane (Fig. 3 Parallel to the paper surface). By doing so, interference fringes crossing in the direction of the flow of the fluid 91 in the flow cell 90 are formed on the imaging surface of the imaging unit 30. Flow - interference fringes that cross the direction of flow of the fluid 91 in the cell 90 to be formed on the imaging surface of the imaging unit 30 adjusts the orientation of the reflecting surface of the mirror M ₁₁ or mirror M ₁₂ or, the lens L ₁₂ ~ it may be to adjust the optical axis of any lens of the L _15. Preferably, the direction of the interference fringes is orthogonal to the direction of the flow of the fluid 91 in the flow cell 90.

  4 and 5 are diagrams illustrating examples of interference light images acquired by the imaging unit 20 of the observation apparatus 1A according to the first embodiment. In any of these cases, a state in which an image of interference light (interference fringes) in a limited range in a direction orthogonal to the interference fringes is acquired is shown by simulation. FIG. 4 shows the interference fringes when the inspection object 92 does not exist in the region where the interference fringes are observed in the flow cell 90. FIG. 5 shows the interference fringes when the inspection object 92 is present in the region where the interference fringes are observed in the flow cell 90, and the inspection object 92 is indicated by a broken line.

  As shown in FIG. 4, when the inspection object 92 does not exist in the region where the interference fringes are observed in the flow cell 90, each lattice of the interference fringes is linear. On the other hand, as shown in FIG. 5, when the inspection object 92 exists in the region where the interference fringes are observed in the flow cell 90, the lattices of the interference fringes are deviated from the straight lines at the locations where they exist. The amount of deviation from this straight line reflects the optical thickness of the inspection object 92.

  Therefore, in order to quantitatively determine the amount of interference fringe deviation from the straight line, the analysis unit 30 performs processing including Fourier transform as follows. The analysis performed by the analysis unit 30 described below may be performed in parallel with the image capturing performed by the image capturing unit 20. In addition, it is preferable that the imaging surface of the imaging unit 20 has a plurality of pixels two-dimensionally arranged in a first direction (a direction orthogonal to the fluid flow direction) and a second direction. Such an arrangement is advantageous for the following processing.

  FIG. 6 is a diagram for explaining the contents of processing in the analysis unit 30 of the observation apparatus 1A according to the first embodiment. 5A is the same as FIG. 5 and shows the interference fringes in the case where the inspection object 92 exists in the region where the interference fringes are observed in the flow cell 90. FIG. In this image, an XY orthogonal coordinate system is set with the first direction orthogonal to the fluid flow direction as the X-axis direction and the second direction perpendicular thereto as the Y-axis direction. The luminance value at the position (X, Y) is represented as A (X, Y).

  FIG. 6B shows the intensity distribution A (X, Y) in the Y-axis direction at a certain position (a certain X value) in the X-axis direction indicated by a broken line in the interference fringe image shown in FIG. Show. FIG. 6C shows a phase distribution φ (X) obtained by performing Fourier transform on the intensity distribution A (X, Y) in FIG. FIG. 6D shows the phase distribution φ (X) in FIG. 6C converted into a range of ± π or more by unwrapping.

  The phase distribution φ (X) is obtained by the following equation (1). Here, j is an imaginary unit. N is the number of pixels in the Y-axis direction. ω is the main spatial frequency of the interference fringes. The right side of the following equation (1a) represents the complex spectral component of the spatial frequency ω. This phase distribution φ (X) represents the X-axis direction distribution of the optical thickness at a certain position in the Y-axis direction (flow direction) of the inspection object 92. Then, the fluid 91 including the inspection object 92 is caused to flow in the Y-axis direction in the flow cell 90, and the phase distribution φ (X) is repeatedly acquired to obtain a two-dimensional phase distribution (phase image) of the inspection object 92. be able to.

  When acquiring a phase image in the present embodiment, the processing is simple and the processing speed is high. Therefore, the phase image of the inspection object 92 contained in the fluid flowing through the flow cell 90 can be observed with high throughput.

  A simulation was performed to confirm the effectiveness of observation of the inspection object by the observation apparatus 1A according to the first embodiment. FIG. 7 is a diagram for explaining a simulation method for observing an inspection object by the observation apparatus 1A according to the first embodiment. In this figure, a rectangular area indicated by a broken line represents the field of view of the imaging unit 20, and interference fringes can be formed in a limited range (range near the center in the Y-axis direction) of the field area. It is assumed that a phase object flows from bottom to top with respect to such a field of view. This phase object is a phase image of an actual cell imaged by another method. In this phase image, the phase value is expressed by density. In this phase image, the upper small cells are leukocytes, and the lower large cells are cancer cells.

  FIG. 8 is a diagram illustrating a phase image used in the simulation of the observation of the inspection object by the observation apparatus 1A according to the first embodiment. FIG. 9 is a diagram showing a phase image obtained by this simulation. In these phase images, the phase value is expressed by density. FIG. 10 is a diagram showing a phase distribution in the X-axis direction at a certain Y value in the phase image of FIG. FIG. 11 is a diagram showing a phase distribution in the X-axis direction at a certain Y value in the phase image of FIG. 10 and 11 each show the phase distribution in the X-axis direction for the same Y value (horizontal line position in FIGS. 8 and 9). As can be seen by comparing them, the phase images (FIGS. 9 and 11) obtained by the simulation are in good agreement with the phase images (FIGS. 8 and 10) used in the simulation. That is, the effectiveness of observation of the inspection object by the observation apparatus 1A according to the first embodiment was confirmed.

  FIG. 12 is a configuration diagram of the cell sorting apparatus 2 including the observation apparatus 1A according to the first embodiment. This cell sorting apparatus 2 includes not only the observation apparatus 1A described above but also a supply unit 50 and flow paths 60 to 62. In this figure, the components from the light source unit 10 to the analysis unit 30 in the observation apparatus 1A are shown as one box.

  The flow path of the flow cell 90 has a Y-branch shape, the common flow path 90 c is connected to the supply unit 50 by the flow path 60, one branch flow path 90 a is connected to the flow path 61, and the other branch flow The path 90 b is connected to the flow path 62. The supply unit 50 stores blood as the fluid 91, and flows the blood from the flow channel 60 to the common flow channel 90 c of the flow cell 90.

  In the observation apparatus 1A, the inspection light is passed through the common flow path 90c of the flow cell 90, the blood (fluid 91) flowing through the common flow path 90c is observed, and the cells contained in the blood (test object 92) Are obtained by the analysis unit 30 and the phase image is displayed by the display unit 40. Further, the analysis unit 30 determines whether or not the cell represented by the obtained phase image is a cancer cell. When it is determined that the cell represented by the obtained phase image is a cancer cell, the blood containing the cell is flowed to the flow path 61, and otherwise, the blood is flowed to the flow path 62.

  In this way, the cell sorting device 2 can identify cancer cells based on the phase image of the cells contained in the blood flowing in the flow cell 90 and remove or collect the cancer cells. Due to the high processing throughput, the time to process all human blood (approximately 5000 mL) can be reduced.

  (Second Embodiment)

Next, a second embodiment of the observation apparatus according to the present invention will be described. FIG. 13 is a configuration diagram of an observation apparatus 1B according to the second embodiment. Observation apparatus 1B shown in this figure includes a light source unit 10, imaging unit 20, the analyzing unit 30, a display unit 40, the flow cell 90, half mirror _{HM 21,} the lens _L 21 _{~L 24} and the mirror _M 21 _{~M 23.} This observation apparatus 1B has a Michelson interferometer optical system. The light source unit 10, the imaging unit 20, the analysis unit 30, the display unit 40, and the flow cell 90 are the same as those in the first embodiment.

The lens L ₂₁ collimates the light output from the light source unit 10 and outputs the collimated light to the half mirror HM ₂₁ . The half mirror HM ₂₁ acts as a branching unit that splits the light output from the light source unit 10 and collimated by the lens L ₂₁ into two and outputs the light as inspection light and reference light.

The light (inspection light) transmitted through the half mirror HM ₂₁ passes through the objective lens L ₂₂ , is reflected by the mirror M ₂₂ , and passes through the objective lens L ₂₂ again and is input to the half mirror HM ₂₁ . The reciprocating optical path between the half mirror HM ₂₁ and the mirror M ₂₂ constitutes an inspection optical system that guides inspection light. The optical path of the inspection light between the objective lens L ₂₂ and the mirror M ₂₂ intersects with the fluid flow in the flow cell 90.

The light (reference light) reflected by the half mirror HM ₂₁ is reflected by the mirror M ₂₁ , passes through the objective lens L ₂₃ , is reflected by the mirror M ₂₃ , passes through the objective lens L ₂₃ and the mirror M ₂₁ again, and is then a half mirror. is input to the HM _21. The reciprocating optical path between the half mirror HM ₂₁ and the mirror M ₂₃ constitutes a reference optical system that guides the reference light. This reference optical system is an optical system equivalent to that obtained by removing the flow cell 90 from the inspection optical system, and has the same optical path length.

The half mirror HM ₂₁ causes the inspection light guided by the inspection optical system and the reference light guided by the reference optical system to interfere with each other to generate interference fringes that cross in the direction of fluid flow in the flow cell 90. The interference light is output to the imaging unit 20 and acts as an interference unit. The imaging unit 20 functions as an interference fringe acquisition unit that acquires an image of interference light in a range limited in a direction orthogonal to the interference fringe among the interference light output from the half mirror HM ₂₁ . The analysis unit 30 performs the same processing as that of the first embodiment on the image obtained by the imaging unit 20.

FIG. 14 is a perspective view of the lens L ₂₂ , the flow cell 90 and the mirror M ₂₂ included in the observation apparatus 1B according to the second embodiment. FIG. 15 is a side view of the lens L ₂₂ , the flow cell 90 and the mirror M ₂₂ included in the observation apparatus 1B according to the second embodiment. The fluid 91 flowing through the flow cell 90 includes an inspection object 92. For example, the fluid 91 is blood, and the test object 92 is red blood cells, white blood cells, cancer cells, and the like.

As shown in FIG. 15, the principal ray of the inspection light between the objective lens L ₂₂ and the mirror M ₂₂ is inclined with respect to the optical axis of the objective lens L ₂₂ . The principal ray of the inspection light between the objective lens L ₂₂ and the mirror M ₂₂ , the optical axis of the objective lens L ₂₂ , and the direction of the flow of the fluid 91 in the flow cell 90 are parallel to a common plane (the paper surface of FIG. 15). It is. By doing so, interference fringes crossing in the direction of the flow of the fluid 91 in the flow cell 90 are formed on the imaging surface of the imaging unit 30. In order to form interference fringes crossing in the flow direction of the fluid 91 in the flow cell 90 on the imaging surface of the imaging unit 30, the orientation of the reflecting surface of any one of the mirrors M _{21 to} M ₂₃ is adjusted. The optical axis of any one of the lenses L _{21 to} L ₂₄ may be adjusted. Preferably, the direction of the interference fringes is orthogonal to the direction of the flow of the fluid 91 in the flow cell 90.

  The observation apparatus 1B according to the second embodiment can also achieve the same effects as the observation apparatus 1A according to the first embodiment. Further, the observation apparatus 1B according to the second embodiment can also be used in place of the observation apparatus 1A in the cell sorting apparatus 2 shown in FIG.

  (Third embodiment)

Next, a third embodiment of the observation apparatus according to the present invention will be described. FIG. 16 is a configuration diagram of an observation apparatus 1C according to the third embodiment. Observation apparatus 1C shown in this figure, the light source unit 11, a filter 21, an imaging unit 20, the analyzing unit 30, a display unit 40, the flow cell 90, half mirror _HM 11, _{HM 12,} the lens _L 11 _{~L 15} and the mirror _{M 11} , equipped with a _{M 12.} Compared to the configuration of the observation apparatus 1A according to the first embodiment shown in FIG. 1, the observation apparatus 1C according to the third embodiment is different in that the light source unit 11 is provided instead of the light source unit 10, and imaging is performed. The difference is that a filter 21 provided in front of the imaging surface of the unit 20 is further provided.

The light source unit 11 may output light having a long coherence length such as laser light. The filter 21 is a spatial filter that selectively transmits interference light in a limited range in the direction orthogonal to the interference fringes among the interference light output from the half mirror HM ₁₂ . The transmittance distribution in the filter 21 is uniform in the direction parallel to the interference fringes (first direction), and is preferably unimodal (for example, Gaussian type or Lorentz type) in the direction orthogonal thereto. . The imaging unit 20 captures an image of interference light transmitted by the filter 21.

FIG. 17 is a diagram illustrating an example of an image of interference light input to the filter 21 of the observation apparatus 1C according to the third embodiment. FIG. 18 is a diagram illustrating a transmittance distribution of the filter 21 of the observation apparatus 1C according to the third embodiment. FIG. 19 is a diagram illustrating an example of an image of interference light that is transmitted through the filter 21 of the observation apparatus 1 </ b> C according to the third embodiment and is captured by the imaging unit 20. The interference light image (FIG. 19) imaged by the imaging unit 20 is obtained by multiplying the interference light image (FIG. 17) input to the filter 21 by the transmittance distribution (FIG. 18) of the filter 21. As described above, the filter 21 and the imaging unit 20 act as an interference fringe acquisition unit that acquires an image of interference light in a limited range in a direction orthogonal to the interference fringe among the interference light output from the half mirror HM _12. . The analysis unit 30 performs the same processing as that of the first embodiment on the image obtained by the imaging unit 20.

  The observation device 1C according to the third embodiment can also achieve the same effects as the observation device 1A according to the first embodiment. Further, the observation apparatus 1C according to the third embodiment can also be used in place of the observation apparatus 1A in the cell sorting apparatus 2 shown in FIG.

  (Fourth embodiment)

Next, a fourth embodiment of the observation apparatus according to the present invention will be described. FIG. 20 is a configuration diagram of an observation apparatus 1D according to the fourth embodiment. Observation device 1D shown in this figure, the light source unit 11, imaging unit 20, the image processing unit 31, the analyzing unit 30, a display unit 40, the flow cell 90, half mirror _HM 11, _{HM 12,} the lens _L 11 _{~L 15} and mirror M ₁₁ and M ₁₂ are provided. Compared with the configuration of the observation apparatus 1A according to the first embodiment shown in FIG. 1, the observation apparatus 1D according to the fourth embodiment is different in that the light source unit 11 is provided instead of the light source unit 10, and imaging is performed. The difference is that an image processing unit 31 provided between the unit 20 and the analysis unit 30 is further provided.

The light source unit 11 may output light having a long coherence length such as laser light. The imaging unit 20 captures an image of interference light output from the half mirror HM ₁₂ . The image processing unit 31 performs a filtering process on the image obtained by imaging by the imaging unit 20 and acquires an image of interference light in a limited range in a direction orthogonal to the interference fringes. The filtering process in the image processing unit 31 is a process equivalent to the filter 21 used in the third embodiment. As described above, the imaging unit 20 and the image processing unit 31 serve as an interference fringe acquisition unit that acquires an image of interference light in a limited range in a direction orthogonal to the interference fringe among the interference light output from the half mirror HM _12. Works.

  That is, when acquiring an image of interference light in a limited range in the direction orthogonal to the interference fringes of the interference light, the third embodiment uses the filter 21 provided in front of the imaging surface of the imaging unit 20. In contrast, in the fourth embodiment, image processing is performed by the image processing unit 31 provided between the imaging unit 20 and the analysis unit 30. The analysis unit 30 performs the same processing as in the first embodiment on the image after being processed by the image processing unit 31.

  The observation apparatus 1D according to the fourth embodiment can also achieve the same effects as the observation apparatus 1A according to the first embodiment. Further, the observation apparatus 1D according to the fourth embodiment can also be used in place of the observation apparatus 1A in the cell sorting apparatus 2 shown in FIG.

  (Other embodiments)

  The observation apparatuses 1C and 1D according to the third and fourth embodiments described above have the optical system of the Mach-Zehnder interferometer, but may have the optical system of the Michelson interferometer. Even in the latter case, the light source unit that outputs light having a long coherence length such as laser light is used, and the filter 21 or the image processing unit 31 is further provided, and the analysis unit 30 performs the same processing.

In the third and fourth embodiments (or the configuration of the optical system of the Michelson interferometer), the direction orthogonal to the interference fringes of the interference light output from the half mirror HM ₁₂ is limited. When acquiring an image of interference light in a range, the limited range may be composed of a plurality of discrete ranges. In this case, the filter 21 having a plurality of transmission regions is used, or processing equivalent to this filter is performed in the image processing unit 31.

It is a lineblock diagram of observation device 1A concerning a 1st embodiment. It is a perspective view of the objective lens L ₁₃ and the flow cell 90 included in the observation apparatus 1A according to the first embodiment. Lens _{L 12} included in the observation apparatus 1A according to the first embodiment, it is a side view of the objective lens _{L 13} and the flow cell 90. It is a figure which shows the example of the image of the interference light acquired by the imaging part 20 of 1 A of observation apparatuses which concern on 1st Embodiment. It is a figure which shows the example of the image of the interference light acquired by the imaging part 20 of 1 A of observation apparatuses which concern on 1st Embodiment. It is a figure explaining the content of the process in the analysis part 30 of 1 A of observation apparatuses which concern on 1st Embodiment. It is a figure explaining the method of simulation of observation of the inspection subject by observation device 1A concerning a 1st embodiment. It is a figure which shows the phase image used by simulation of observation of the test target object by 1 A of observation apparatuses which concern on 1st Embodiment. It is a figure which shows the phase image obtained by simulation of observation of the test object by 1 A of observation apparatuses which concern on 1st Embodiment. It is a figure which shows the phase distribution of the X-axis direction in a certain Y value among the phase images of FIG. It is a figure which shows the phase distribution of the X-axis direction in a certain Y value among the phase images of FIG. It is a lineblock diagram of cell sorter 2 containing observation device 1A concerning a 1st embodiment. It is a block diagram of the observation apparatus 1B which concerns on 2nd Embodiment. Lens _{L 22} included in the observation apparatus 1B according to the second embodiment, a perspective view of a flow cell 90 and the mirror _{M 22.} Lens _{L 22} included in the observation apparatus 1B according to the second embodiment, a side view of the flow cell 90 and the mirror _{M 22.} It is a block diagram of the observation apparatus 1C which concerns on 3rd Embodiment. It is a figure which shows the example of the image of the interference light input into the filter 21 of 1 C of observation apparatuses which concern on 3rd Embodiment. It is a figure which shows the transmittance | permeability distribution of the filter 21 of 1 C of observation apparatuses which concern on 3rd Embodiment. It is a figure which shows the example of the image of the interference light which permeate | transmits with the filter 21 of 1 C of observation apparatuses which concern on 3rd Embodiment, and is imaged by the imaging part 20. FIG. It is a block diagram of observation apparatus 1D which concerns on 4th Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1A-1D ... Observation apparatus, 2 ... Cell sorting apparatus, 10, 11 ... Light source part, 20 ... Imaging part, 21 ... Filter, 30 ... Analysis part, 31 ... Image processing part, 40 ... Display part, 90 ... Flow cell.

Claims (5)

A flow cell for flowing a fluid containing an inspection object;
A light source unit that outputs light;
A branching unit that splits the light output from the light source unit into two to output as inspection light and reference light;
An inspection optical system that guides the inspection light so that an optical path of the inspection light output from the branch section intersects the flow of the fluid in the flow cell;
A reference optical system for guiding the reference light output from the branching unit;
The inspection light guided by the inspection optical system and the reference light guided by the reference optical system interfere with each other to generate interference fringes that cross in the direction of fluid flow in the flow cell, and output the interference light An interference part to
An interference fringe acquisition unit that acquires an image of interference light in a limited range with respect to a direction orthogonal to the interference fringe out of the interference light output from the interference unit;
For each position in the first direction orthogonal to the direction of fluid flow in the flow cell in the image obtained by the interference fringe acquisition unit, with respect to the intensity distribution of the interference fringe in the second direction orthogonal to the first direction. An analysis unit for performing a one-dimensional spatial Fourier transform to obtain a phase image of an inspection object contained in a fluid flowing through the flow cell;
An observation apparatus comprising: The light source unit outputs light having a coherence length shorter than 10 times the output wavelength;
The interference fringe acquisition unit acquires an image of interference light in a range limited according to the coherence length;
The observation apparatus according to claim 1. The interference fringe acquisition unit
A filter that selectively transmits interference light in a limited range with respect to a direction orthogonal to interference fringes among interference light output from the interference unit;
An imaging unit that captures an image of the interference light transmitted by the filter;
The observation apparatus according to claim 1, comprising: The interference fringe acquisition unit
An imaging unit that captures an image of interference light output from the interference unit;
An image processing unit that processes an image captured by the imaging unit and acquires an image of interference light in a limited range in a direction orthogonal to the interference fringes;
The observation apparatus according to claim 1, comprising: The observation apparatus according to claim 1, wherein the interference fringe acquisition unit includes an imaging unit having an imaging surface in which a plurality of pixels are two-dimensionally arranged in the first direction and the second direction.