Observation device, optical deflection unit, and image forming method

Abstract

To realize high observation performance irrespective of a container that accommodates a sample.SOLUTION: An observation device 10 includes a housing 12 having a transmission window 11, for accommodating a light source unit 14 and an imaging unit 15. The observation device 10 comprises the light source unit 14, the imaging unit 15 and a light deflection unit 100. The imaging unit 15 includes an imaging element and an optical system for condensing light having entered the inside of the housing 12 by passing through the transmission window 11 in order to form the image of a sample in a culture vessel C. The light source unit 14 emits light toward the outside of the housing 12 not passing through the optical system of the imaging unit 15. The light deflection unit 100 deflects the light emitted from the light source unit 14 to the outside of the housing 12 in a first direction heading toward the transmission window 11. An emission angle which is the angle formed between the first direction and the optical axis of the optical system of the imaging unit 15 is different from an incidence angle which is the angle between a second direction in which the light emitted to the outside of the housing 12 enters the light deflection unit 100 and the optical axis.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The disclosure of the present specification relates to an observation device, an optical deflection unit, and an image forming method. [Background technology]

[0002] The cultivation of biological samples such as cells is carried out in an incubator to maintain a culture environment. The condition of the biological samples is periodically checked during cultivation, but removing the biological samples from the incubator each time a check is performed may adversely affect the growth of the biological samples.

[0003] A technology related to such a problem is described, for example, in Patent Document 1. By using an observation device employing the oblique illumination described in Patent Document 1, it is possible to observe samples such as cells without increasing the size of the device. This makes it possible to continuously observe the biological sample being cultured in the limited space inside the incubator without removing the biological sample from the incubator. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US Patent Application Publication No. 2019 / 0187450 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, Patent Document 1 describes conditions for achieving both compactness of the device and high contrast. By satisfying the conditions described in Patent Document 1, it is possible to three-dimensionally observe a sample with high contrast. However, since this condition includes the height of the reflecting surface, which is restricted by the container that holds the sample, there is a possibility that the container that can satisfy the condition is limited.

[0006] In view of the above circumstances, an object of one aspect of the present invention is to provide a technique that realizes high observation performance regardless of the container that holds the sample. [Means for solving the problem]

[0007] An observation device according to one aspect of the present invention includes a housing having a transmission window, and an imaging unit housed in the housing, the imaging unit including an imaging element and an optical system that collects light that has entered the housing by passing through the transmission window to form an image of a sample in a container placed on the transmission window on the imaging element, a light source unit housed in the housing, the light source unit emitting light toward the outside of the housing without passing through the optical system, and an optical deflection unit that deflects the light emitted from the light source unit to the outside of the housing in a first direction toward the transmission window, wherein an emission angle that is an angle between the first direction and an optical axis of the optical system is different from an incidence angle that is an angle between a second direction in which the light emitted to the outside of the housing is incident on the optical deflection unit and the optical axis. The optical deflection unit includes at least one reflecting surface that reflects light incident on the optical deflection unit, and at least one refracting surface that refracts the light incident on the optical deflection unit, and the at least one refracting surface is provided on an optical path between the at least one reflecting surface and the transmission window. do.

[0008] The present invention Another Related to the aspect The observation device includes a housing having a transmission window, an imaging unit housed in the housing, the imaging unit including an imaging element and an optical system that collects light that has entered the housing by passing through the transmission window to form an image of a sample in a container placed on the transmission window on the imaging element, a light source unit housed in the housing, the light source unit emitting light toward the outside of the housing without passing through the optical system, and an optical deflection unit that deflects the light emitted from the light source unit to the outside of the housing in a first direction toward the transmission window, the first direction and the optical system and an optical deflection unit in which an exit angle, which is the angle between the optical axis of the first direction and the second direction in which the light emitted to the outside of the housing is incident on the optical deflection unit, is different from an entrance angle, which is the angle between the optical axis and a second direction in which the light emitted to the outside of the housing is incident on the optical deflection unit, the optical deflection unit including at least one reflecting surface that reflects the light incident on the optical deflection unit, and a prism plate having a plurality of refracting surfaces aligned in a direction intersecting the optical axis, each of the plurality of refracting surfaces being refracting surfaces inclined with respect to the optical axis and refracting the light incident on the optical deflection unit, and being provided on the optical path between the at least one reflecting surface and the transmission window.

[0009] An image forming method according to one embodiment of the present invention includes emitting light from inside a housing to outside the housing, deflecting the light emitted outside the housing in a first direction toward a transparent window of the housing using an optical deflection unit, and focusing the light that has entered the housing by passing through the transparent window using an optical system inside the housing to form an image of a sample in a container placed on the transparent window on an imaging element, wherein an emission angle, which is the angle between the first direction and the optical axis of the optical system, is different from an incidence angle, which is the angle between a second direction in which the light emitted outside the housing enters the optical deflection unit and the optical axis, and the optical deflection unit includes at least one reflective surface that reflects the light that enters the optical deflection unit and at least one refracting surface that refracts the light that enters the optical deflection unit, and the at least one refracting surface is arranged on the optical path between the at least one reflective surface and the transparent window. An image forming method according to another aspect of the present invention includes emitting light from inside a housing to outside the housing, deflecting the light emitted outside the housing in a first direction toward a transmission window of the housing by an optical deflection unit, and concentrating the light that has entered the housing by passing through the transmission window by an optical system inside the housing to form an image of a sample in a container placed on the transmission window, and an emission angle, which is the angle between the first direction and an optical axis of the optical system, is different from an incidence angle, which is the angle between a second direction in which the light emitted outside the housing enters the optical deflection unit and the optical axis. The optical deflection unit includes at least one reflecting surface that reflects light incident on the optical deflection unit, and a prism plate having a plurality of refracting surfaces aligned in a direction intersecting the optical axis, each of the plurality of refracting surfaces being inclined with respect to the optical axis and refracting the light incident on the optical deflection unit, and being provided on an optical path between the at least one reflecting surface and the transmission window. . Effect of the Invention

[0010] According to the above aspect, it is possible to provide a technique that realizes high observation performance regardless of the container that holds the sample. [Brief description of the drawings]

[0011] [Figure 1] 1 is a diagram illustrating a configuration of a system 1 according to a first embodiment. [Diagram 2] 1 is a diagram illustrating the configuration of an observation device 10 according to a first embodiment. [Diagram 3] FIG. 13 is a diagram for explaining the relationship between the height of a culture vessel and a light flux. [Figure 4] 4 is a diagram for explaining the relationship between the angle of incidence of a ray bundle on a sample and the distribution of the ray bundle on a pupil plane. FIG. [Diagram 5] FIG. 2 is a diagram showing the external appearance of an observation device 10 to which a light deflection unit is attached. [Figure 6] 3A and 3B are diagrams illustrating an example of a configuration of a light deflection unit. [Figure 7] 4 is a flowchart for explaining an example of an image forming method performed by the observation device 10. [Figure 8] 10A and 10B are diagrams for explaining another example of the configuration of the optical deflection unit. [Figure 9] 13 is a diagram for explaining still another example of the configuration of the optical deflection unit. FIG. [Figure 10] 13 is a diagram for explaining still another example of the configuration of the optical deflection unit. FIG. [Figure 11] FIG. 13 is a diagram illustrating the configuration of an observation device 10a according to a second embodiment. [Figure 12] 13 is a diagram for explaining still another example of the configuration of the optical deflection unit. FIG. [Figure 13] FIG. 13 is a diagram illustrating the configuration of an observation device 10b according to a third embodiment. [Figure 14] 13 is a diagram for explaining still another example of the configuration of the optical deflection unit. FIG. [Figure 15] 13 is a diagram for explaining still another example of the configuration of the optical deflection unit. FIG. [Figure 16] 13 is a diagram for explaining still another example of the configuration of the optical deflection unit. FIG. [Figure 17] 13 is a diagram for explaining still another example of the configuration of the optical deflection unit. FIG. [Figure 18] 13 is a diagram for explaining still another example of the configuration of the optical deflection unit. FIG. [Figure 19] 13 is a diagram for explaining still another example of the configuration of the optical deflection unit. FIG. [Figure 20] FIG. 13 is a diagram illustrating the configuration of an observation apparatus 10c according to a fourth embodiment. [Figure 21] 13 is a diagram for explaining still another example of the configuration of the optical deflection unit. FIG. [Figure 22] 10A and 10B are diagrams for explaining uses of the observation device 10c. [Diagram 23] 11A and 11B are diagrams illustrating a method of using the optical deflection unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] [First embodiment] Fig. 1 is a diagram illustrating an example of the configuration of a system 1 according to this embodiment. The system 1 shown in Fig. 1 is an observation system that observes a sample contained in a culture container C. The system 1 includes an observation device 10 that acquires an image of the sample being cultured in the culture container C, and a control device 30 that controls the observation device 10.

[0013] In order to observe the sample without removing it from the incubator 20, the observation device 10 is used while being placed in the incubator 20, for example, as shown in Fig. 1. More specifically, the observation device 10 is placed in the incubator 20 with the culture container C placed on the transmission window 11 of the observation device 10, and acquires an image of the sample in the culture container C according to instructions from the control device 30. The transmission window 11 is a transparent top plate that constitutes the upper surface of the housing 12 of the observation device 10, and is made of, for example, glass or transparent resin.

[0014] The control device 30 transmits an image acquisition instruction to the observation device 10 placed in the incubator 20, and receives an image acquired by the observation device 10. The control device 30 may display the image acquired by the observation device 10 on a display device provided in the control device 30. The control device 30 may communicate with client terminals (client terminal 40, client terminal 50), and may display the image acquired by the observation device 10 on a display device provided in the client terminal. Note that the control device 30 may be a general computer or a dedicated device as long as it includes one or more processors and one or more non-transitory computer-readable media.

[0015] 1 shows an example in which the observation device 10 and the control device 30 are connected by wire. However, it is sufficient if the observation device 10 and the control device 30 can exchange data. Therefore, the observation device 10 and the control device 30 may be connected wirelessly, not limited to being connected by wire.

[0016] Fig. 2 is a diagram illustrating the configuration of the observation device 10 according to this embodiment. Fig. 3 is a diagram for explaining the relationship between the height of the culture vessel and the light beam. Fig. 4 is a diagram for explaining the relationship between the incident angle of the light beam to the sample and the distribution of the light beam on the pupil plane. The configuration and operation of the observation device 10 will be described below with reference to Figs. 2 to 4.

[0017] The observation device 10 includes a box-shaped housing 12 having a transparent transmission window 11 on the upper surface in which a culture vessel C is placed. The culture vessel C contains a sample S and a culture solution CL. The observation device 10 further includes a light source unit 14 that illuminates the sample and an imaging unit 15 that captures an image of the sample, both of which are housed inside the housing 12. The light source unit 14 and the imaging unit 15 are installed on a stage 13, and move relative to the culture vessel C as the stage 13 moves within the housing 12. In this way, the observation device 10 can illuminate a sample present at an arbitrary position in the culture vessel C with the light source unit 14, and capture an image of the sample with the imaging unit 15.

[0018] Note that Figure 2 shows an example in which the light source unit 14 and the imaging unit 15 are installed on the stage 13 and, as a result, move together within the housing 12; however, the light source unit 14 and the imaging unit 15 may also move independently within the housing 12.

[0019] As shown in Fig. 3, the light source unit 14 includes a light source 16 and a diffusion plate 17. The light source 16 includes, for example, a light emitting diode (LED). The light source 16 may include a white LED, or may include a plurality of LEDs that emit light of a plurality of different wavelengths, such as R (red), G (green), and B (blue). The light emitted from the light source 16 is incident on the diffusion plate 17. The configuration of the light source 16 is not particularly limited, but if an LED is used, it can have a longer life and be less expensive than a general halogen lamp or the like.

[0020] The diffusion plate 17 diffuses the light emitted from the light source 16. The diffusion plate 17 is not particularly limited, but may be, for example, a frosted diffusion plate having an uneven surface. However, the diffusion plate 17 may be an opal diffusion plate having a coated surface, or may be another type of diffusion plate. Furthermore, a mask 17a may be formed on the diffusion plate 17 to limit the emission area of ​​the diffused light. The light emitted from the diffusion plate 17 travels in various directions.

[0021] As shown in FIG. 3, the imaging unit 15 includes an optical system 18 and an image sensor 19. The optical system 18 collects light that is incident on the housing 12 by passing through the sample S and the transmission window 11. The optical system 18 is not particularly limited, but may be, for example, a finite correction type objective lens that forms an image at a finite position. However, the optical system 18 may include an infinity correction type objective lens, and the optical system 18 as a whole may constitute a finite correction optical system. The optical system 18 focuses on the inner bottom surface of the culture vessel C in which the sample S is present, and collects light that is incident on the housing 12 onto the image sensor 19, thereby forming an optical image of the sample S on the image sensor 19.

[0022] The imaging element 19 is an optical sensor that converts detected light into an electrical signal. The imaging element 19 is specifically an image sensor, and is not particularly limited, but may be, for example, a CCD (Charge-Coupled Device) image sensor or a CMOS (Complementary MOS) image sensor.

[0023] In the observation device 10 configured as above, oblique illumination is adopted to visualize the sample S in the culture vessel C, which is a phase object. Specifically, as shown in FIG. 3, the light emitted by the light source 16 is diffused by the diffusion plate 17 and emitted outside the housing 12 without passing through the optical system 18. That is, the light source unit 14 emits light traveling in various directions toward the outside of the housing 12 without passing through the optical system 18. Then, a part of the light emitted outside the housing 12 is reflected, for example, by the upper surface of the culture vessel C, and is deflected above the sample S. Furthermore, a part of the light deflected above the sample S is irradiated onto the sample S and enters the housing 12 by passing through the sample S and the transmission window 11. Then, a part of the light entering the housing 12 is collected by the optical system 18 to form an image of the sample on the image sensor 19. That is, the optical system 18 collects light that has passed through the transmission window 11 and entered the housing 12, in order to form an image of the sample S in the culture vessel C placed on the transmission window 11 on the imaging element 19. Finally, the observation device 10 generates an image of the sample S based on the electrical signal output from the imaging element 19, and outputs the image to the control device 30.

[0024] Incidentally, in order to visualize the sample S, which is a phase object, with high contrast by using oblique illumination and to make it possible to recognize cells and the like, it is important to form an image of the sample S by concentrating light rays incident on the sample S at an appropriate angle. In the observation device 10, light that is diffused by the diffuser plate 17 and travels in various directions is deflected above the sample S and enters the optical system 18 from various angles, but the angular distribution of light that enters the optical system 18 depends on the height of the deflection surface, for example, the height of the top surface of the culture vessel. More specifically, the higher the height of the top surface of the culture vessel, which is the deflection surface, the more light with a small angle of incidence there is.

[0025] For example, assume that an image of a sample S is formed using light reflected from the top surface of a culture vessel. In this case, as shown in Figures 3 and 4, when comparing a light beam L1 passing through a point P on the sample S when a culture vessel C of a standard height (e.g., 60 mm) is used, and a light beam L2 passing through a point P on the sample S when a culture vessel C1 that is taller than the culture vessel C is used, the light beam L2 is distributed at a smaller angle of incidence on the object surface than the light beam L1.

[0026] The incident angle on the object plane is converted by the optical system 18 into a distance from the optical axis on the pupil plane of the optical system 18. Therefore, the light beam L1, which has a relatively large incident angle on the object plane, passes through a position on the pupil plane that is relatively far from the optical axis. As a result, the light beam L1 is distributed across the outer edge of the pupil PL of the optical system 18 on the pupil plane, as shown in FIG. 4. The light beams of the light beam L1 that are incident on the outside of the pupil PL are vignetted in the optical system 18 and do not reach the image sensor 19. Therefore, the light beams of the light beam L1 that reach the image sensor 19 have a discontinuous intensity distribution in the angular direction, that is, a steep change in the intensity distribution. As a result, when the culture vessel C is used, a shadow is generated in the image of the sample S, and a three-dimensional image with high contrast can be obtained.

[0027] On the other hand, the light beam L2, whose incident angle on the object plane is distributed at a relatively small angle, passes through a position on the pupil plane that is relatively close to the optical axis. Therefore, as shown in FIG. 4, the entire light beam L2 passes through the inside of the pupil PL on the pupil plane and reaches the image sensor 19. Since the intensity distribution of the light beam L2 changes continuously in the angular direction, the light beam reaching the image sensor 19 does not experience a steep change in intensity distribution in the angular direction. As a result, when the culture vessel C1 is used, it is difficult to generate sufficient shading in the image of the sample S compared to when the culture vessel C is used, and therefore it is difficult to obtain an image with high contrast.

[0028] In this way, when the sample S is visualized by relying on the reflected light on the top surface of the culture vessel, the contrast changes depending on the height of the culture vessel, and the observation performance of the observation device 10 may not be fully demonstrated. To address this issue, it is possible to increase the distance between the light source unit 14 and the imaging unit 15 to increase the angle of incidence. However, such a solution would increase the size of the observation device 10 (particularly the housing 12), and is not a desirable solution for a device that is expected to be used in a limited space such as an incubator 20. Therefore, the observation device 10 according to this embodiment is provided with an optical deflection unit to solve this technical issue and achieve high observation performance without increasing the size of the observation device 10 and regardless of the culture vessel.

[0029] Fig. 5 is a diagram showing the external appearance of the observation device 10 to which the optical deflection unit is attached. Fig. 6 is a diagram for explaining an example of the configuration of the optical deflection unit. Fig. 7 is a flow chart for explaining an example of an image forming method performed by the observation device 10. Hereinafter, the observation device 10 and the image forming method performed by the observation device 10 will be described with reference to Figs. 5 to 7, focusing on the optical deflection unit 100.

[0030] The optical deflection unit 100 is, for example, a detachable unit attached to the observation device 10. In Figs. 5 and 6, an example in which the optical deflection unit 100 is installed on the transmission window 11 of the housing 12 is shown, but the position at which the optical deflection unit 100 is installed is not limited to this example. The optical deflection unit 100 may be installed on a side surface of the housing 12. In addition, an example in which the optical deflection unit 100 is detachably installed on the housing 12 is shown, but the optical deflection unit 100 may be fixed to the housing 12 so as not to be detachable, and may have, for example, a stretchable structure or a foldable structure for storing the optical deflection unit in the housing 12 when not in use. This makes it possible to prevent the optical deflection unit from being unintentionally moved by the user during transportation of the equipment, experimental operation, etc., causing a deviation in the observation optical system. In addition, in Figs. 5 and 6, an example in which the optical deflection unit 100 is installed on the housing 12 is shown, but the optical deflection unit 100 may be included in the observation device 10, and may be disposed away from the housing 12, for example.

[0031] As shown in FIG. 6, the optical deflection unit 100 includes a support 101 and a reflecting surface 102. The support 101 has a shape bent between a base end fixed to the transmission window 11 and a free end, and includes a first portion including the base end and extending vertically, and a second portion including the free end and extending obliquely from the first portion. More specifically, the first portion extends to a sufficient height so that even if a tall culture vessel is placed on the transmission window 11, the culture vessel does not come into contact with the second portion. Moreover, the second portion extends upward from the first portion in the horizontal direction in order to optimize the angular distribution of light incident on the imaging unit 15. The optical deflection unit 100 may be configured without the support 101.

[0032] The reflecting surface 102 is formed on a surface of the second portion of the support 101 facing the transmission window 11. Since the second portion extends upward relative to the horizontal direction, the reflecting surface 102 is inclined with respect to the optical axis of the optical system 18 included in the imaging unit 15. The reflecting surface 102 being inclined with respect to the optical axis means that the normal to the reflecting surface 102 is oriented in a direction different from the optical axis. The reflecting surface 102 may include, for example, a metal thin film mirror or a dielectric multilayer film mirror formed on the surface of the support 101, which is a base material, or may be configured to reflect incident light without any particular reflection processing.

[0033] In the observation device 10 configured as above, an optical image is formed on the imaging element 19 by the image forming method shown in Fig. 7. Specifically, first, the light source unit 14 emits light from inside the housing 12 toward the outside of the housing 12 (step S1). After that, the optical deflection unit 100 deflects the light emitted to the outside of the housing 12 in a direction toward the transmission window 11 (hereinafter, the first direction) (step S2).

[0034] Specifically, in step S2, the reflecting surface 102 inclined with respect to the optical axis reflects the light that has passed through the upper surface of the culture vessel C and entered the optical deflection unit 100. That is, the optical deflection unit 100 deflects the light that has been emitted from the light source unit 14 to the outside of the housing 12 in a first direction toward the transmission window 11 at an exit angle θex different from the incident angle θin, more specifically, at an exit angle θex larger than the incident angle θin. As shown in FIG. 6, the incident angle θin is the angle between the direction in which the light emitted to the outside of the light source unit 14 enters the optical deflection unit 100 (hereinafter referred to as the second direction) and the optical axis of the optical system 18, and the exit angle θex is the angle between the first direction and the optical axis of the optical system 18.

[0035] As a result, even when a tall culture vessel is used, the light is deflected at a position high enough not to come into contact with the culture vessel, but a ray bundle consisting of light deflected by the light deflection unit 100 and passing through a point on the sample S is distributed across the outer edge of the pupil PL of the optical system 18 on the pupil plane of the optical system 18, just as when a culture vessel of standard height is used. That is, in the light deflection unit 100, the inclination angle of the reflecting surface 102 is determined in advance so that a ray bundle passing through a point on the sample S is distributed across the outer edge of the pupil PL on the pupil plane of the optical system 18.

[0036] Finally, the optical system 18 of the imaging unit 15 collects the light that has passed through the transmission window 11 and entered the housing 12, so as to form an image of the sample S in the culture vessel C placed on the transmission window 11 on the imaging element 19 (step S3). As a result, an optical image of the sample S is formed on the imaging element 19, and the image of the sample S is acquired.

[0037] In the observation device 10 according to this embodiment, an optical image of the sample S can be formed by light deflected by the optical deflection unit 100 at an exit angle θex larger than the incident angle θin. Therefore, according to the observation device 10 according to this embodiment, it is possible to visualize the sample S with high contrast regardless of the culture vessel that contains the sample S, and it is possible to demonstrate high observation performance of the observation device 10. Therefore, it is possible to satisfactorily observe a sample contained in any culture vessel, not limited to the standard culture vessel C.

[0038] Moreover, in the observation device 10 according to this embodiment, the reflecting surface 102 includes a mirror with high reflectance, so that the optical deflection unit 100 can efficiently deflect the incident light. Therefore, the observation device 10 according to this embodiment can obtain a bright image with high contrast.

[0039] Fig. 8 is a diagram for explaining another example of the configuration of the optical deflection unit. Fig. 9 is a diagram for explaining yet another example of the configuration of the optical deflection unit. Fig. 10 is a diagram for explaining yet another example of the configuration of the optical deflection unit. In the above, an example has been described in which the observation device 10 includes the optical deflection unit 100, but the observation device 10 may include an optical deflection unit 110, an optical deflection unit 120, and an optical deflection unit 130 shown in Figs. 8 to 10 instead of the optical deflection unit 100.

[0040] 8 includes a support 111, a movable piece 112 having an axis 114 and supported by the support 111 so as to be rotatable, and a reflecting surface 113 formed on the movable piece 112. The movable piece 112 is an example of an adjustment unit that adjusts the angle of the reflecting surface 113 with respect to the optical axis.

[0041] Even when the observation device 10 includes the optical deflection unit 110 instead of the optical deflection unit 100, it can achieve high observation performance regardless of the culture vessel. Furthermore, by including the optical deflection unit 110, the angle of the reflecting surface 113 with respect to the optical axis can be adjusted using the movable piece 112 to adjust the angular distribution of light incident on the optical system 18. Therefore, it is also possible to adjust the contrast of the image according to the sample S or the observer's preference. Furthermore, the angle of the reflecting surface 113 may be adjusted according to the specifications of the optical system 18 (e.g., observation magnification, numerical aperture), etc. to adjust the contrast of the image.

[0042] 9 includes a support 121, a movable piece 122 having an axis 124 and a surface 125 and supported by the support 121 so as to be rotatable, and a reflecting surface 123 formed on the movable piece 122. The movable piece 122 is an example of an adjustment unit that adjusts the angle of the reflecting surface 123 with respect to the optical axis. The optical deflection unit 120 is similar to the optical deflection unit 110 in that the support 121 has a shape that is bent between a base end fixed to the transmission window 11 and a free end. However, the optical deflection unit 120 differs from the optical deflection unit 110 in that the support 121 includes a first portion that includes the base end and extends in the vertical direction, and a second portion that includes the free end and extends in the horizontal direction from the first portion.

[0043] The observation device 10 can achieve high observation performance regardless of the culture vessel, even when it includes the optical deflection unit 120 instead of the optical deflection unit 100. Furthermore, by including the optical deflection unit 120, the angular distribution of light incident on the optical system 18 can be adjusted, similarly to the optical deflection unit 110, so that the contrast can be adjusted according to the sample S, the observer's preferences, and the like, and according to the specifications of the optical system 18.

[0044] Furthermore, since the support 121 includes the optical deflection unit 120 that is bent in the horizontal direction, the surface 125, which is the upper surface of the support 121, becomes horizontal. Therefore, a culture vessel can be placed on the surface 125. This makes it possible to efficiently utilize the limited space inside the incubator 20.

[0045] The surface 125 is an example of a first surface that does not face the transmission window 11 of the optical deflection unit 120. FIG. 9 shows an example in which the entire surface 125 is horizontal, that is, a plane parallel to the transmission window 11, but it is sufficient that at least a part of the surface 125 is a plane parallel to the transmission window 11 so that the culture vessel can be placed thereon, and it is sufficient that the culture vessel can be supported horizontally. If the culture vessel can be supported horizontally, for example, a positioning member may be provided to make it easy to place the culture vessel, or part of the surface 125 may be provided with irregularities. In the optical deflection units described below, the surface on which the culture vessel can be placed without facing the transmission window of the optical deflection unit is an example of a first surface.

[0046] 10 includes a support 131 having a surface 133, and a reflecting surface 132 formed on the support 131. The optical deflection unit 130 differs from the optical deflection unit 100 in that the surface 133, which is the upper surface of the second portion of the support 131, is a horizontal plane. Other points are similar to those of the optical deflection unit 100.

[0047] Even when the observation device 10 includes the optical deflection unit 130 instead of the optical deflection unit 100, it can achieve high observation performance regardless of the culture vessel. Furthermore, by including the optical deflection unit 130, it is possible to place a culture vessel on the surface 133. This makes it possible to efficiently utilize the limited space inside the incubator 20, similar to the optical deflection unit 120.

[0048] [Second embodiment] Fig. 11 is a diagram illustrating the configuration of an observation device 10a according to this embodiment. The observation device 10a according to this embodiment differs from the observation device 10 according to the first embodiment in that it includes an optical deflection unit 140 instead of the optical deflection unit 100. More specifically, the observation device 10a and the optical deflection unit 140 differ from the observation device 10 and the optical deflection unit 100 in that they have a refracting surface that refracts the light incident thereon by the optical deflection unit in addition to a reflecting surface. A specific description will be given below with reference to Fig. 11.

[0049] The optical deflection unit 140 includes a support 141 having a surface 145, a reflecting surface 142 formed on the support 141, and a prism 143 arranged to cover the reflecting surface 142. The configuration of the optical deflection unit 140 except for the prism 143 is the same as that of the optical deflection unit 130.

[0050] The prism 143 has a wedge shape, and in combination with the second portion of the support 141, forms a flat plate with a uniform thickness. The prism 143 also has a surface 144 facing the transmission window 11. The surface 144 is a refracting surface that refracts the light incident on the light deflection unit 140, and is provided on the light path between the transmission window 11 and the reflecting surface 142. Therefore, the surface 144 acts on the light twice, once before and once after reflection on the reflecting surface 142. In particular, the surface 144 is reflected by the reflecting surface 142, and as a result, the light traveling at a larger angle to the optical axis compared to when it entered can be deflected so that it travels at an even larger angle to the optical axis, so that the incident angle θin and the exit angle θex on the light deflection unit 140 can be made to differ greatly.

[0051] The observation device 10a according to this embodiment can also form an optical image of the sample S by light deflected by the optical deflection unit 140 at an exit angle θex larger than the incident angle θin. Therefore, according to the observation device 10a according to this embodiment, like the observation device 10, it is possible to visualize the sample S with high contrast, and it is possible to demonstrate high observation performance of the observation device 10a regardless of the culture vessel that contains the sample S. Therefore, it is possible to satisfactorily observe a sample contained in any culture vessel, not limited to the standard culture vessel C.

[0052] Furthermore, in the observation device 10a, the angle difference between the incident angle θin and the exit angle θex can be obtained by reflection on the reflecting surface as well as refraction on the refracting surface. Therefore, even when an optical system having a larger numerical aperture is used, the optical performance can be fully exhibited. In addition, since a sufficient angle difference can be obtained even if the inclination of the reflecting surface 142 is suppressed, the thickness of the second portion of the support 141 can also be suppressed.

[0053] Fig. 12 is a diagram for explaining yet another example of the configuration of the optical deflection unit. In the above, the observation device 10a includes the optical deflection unit 140. However, the observation device 10a may include an optical deflection unit 150 shown in Fig. 12 instead of the optical deflection unit 140.

[0054] 12 includes a support 151 having a surface 155, a reflecting surface 152 formed on the support 151, and a prism 153 arranged to cover the reflecting surface 152. These points are similar to those of the optical deflection unit 140.

[0055] Prism 153 is similar to prism 143 in that it has a wedge shape, but differs from prism 143 in that the wedge angle is larger than that of prism 143. As a result, prism 153 also differs from prism 143 in that a surface 154 facing the transmission window 11 (more strictly, the normal to surface 154) is inclined with respect to the optical axis. The inclination direction of surface 154 is opposite to the inclination direction of reflecting surface 152. When reflecting surface 152 is inclined upward with respect to the horizontal direction, surface 154 is inclined downward with respect to the horizontal direction.

[0056] Even if the observation device 10a includes the light deflection unit 150 instead of the light deflection unit 140, it can achieve high observation performance regardless of the culture vessel. In addition, by including the light deflection unit 150 including a refracting surface inclined with respect to the optical axis, as shown in FIG. 12, the light traveling in the vertical direction, where the intensity is expected to be the strongest, and incident on the light deflection unit 150 can be refracted on the surface 154 both before and after reflection on the reflecting surface 152, so that a larger refraction effect can be generated on the refracting surface (surface 154). Therefore, even if an optical system having a larger numerical aperture is used, it is possible to fully exhibit its optical performance.

[0057] [Third embodiment] FIG. 13 is a diagram illustrating the configuration of an observation device 10b according to this embodiment. The observation device 10b according to this embodiment differs from the observation device 10a according to the second embodiment in that it includes an optical deflection unit 160 instead of the optical deflection unit 140. The observation device 10b and the optical deflection unit 160 differ from the observation device 10a and the optical deflection unit 140 according to the second embodiment in that it includes a linear prism plate 163 having multiple refracting surfaces instead of the prism 143 having a refracting surface. Hereinafter, a specific description will be given with reference to FIG. 13.

[0058] The optical deflection unit 160 includes a support 161 having a surface 165, a reflecting surface 162 formed on the support 161, and a linear prism plate 163 arranged to cover the reflecting surface 162. The support 161 includes a first portion extending in the extension direction from the base end, and a second portion extending in the horizontal direction from the first portion, and the reflecting surface 162 is parallel to the transmission window 11.

[0059] The linear prism plate 163 includes a plurality of surfaces 164 that are refracting surfaces aligned in a direction intersecting the optical axis. Each of the surfaces 164 is a refracting surface inclined with respect to the optical axis that refracts the light incident on the light deflection unit 160, and is provided on the optical path between the reflecting surface 162 and the transmission window 11. The plurality of refracting surfaces have the same inclination angle and are formed at regular intervals. That is, the light deflection unit 160 has a periodic structure in a direction intersecting the optical axis. By having such a periodic structure, the linear prism plate 163 can be formed relatively thin while having a sufficient refraction effect that greatly differs the incident angle θin and the exit angle θex on the light deflection unit 160.

[0060] 13, each of the surfaces 164 acts on light in the same manner as the surface 154 shown in FIG. 12, so that the observation device 10b according to this embodiment can also form an optical image of the sample S by the light deflected by the optical deflection unit 160 at an exit angle θex larger than the incident angle θin. Therefore, according to the observation device 10b according to this embodiment, like the observation device 10a, it is possible to visualize the sample S with high contrast, and it is possible to demonstrate high observation performance of the observation device 10b regardless of the culture vessel that contains the sample S. Therefore, it is possible to observe a sample contained in any culture vessel, not limited to the standard culture vessel C, well.

[0061] Furthermore, in the observation device 10b, since the reflection surface 162 is horizontal and not inclined, the thickness of the light deflection unit 160 can be made thin. Even if the light source unit 14 and the imaging unit 15 move within the housing 12 depending on the observation position, the distances from the light source unit 14 and the imaging unit 15 to the surface 164 and the reflection surface 162 do not change substantially. Therefore, the sample S can be observed under the same conditions regardless of the observation position. In addition, since the second part has a horizontal upper surface, an additional culture vessel can be placed on the second part. This makes it possible to efficiently utilize the incubator 20, which has limited space.

[0062] 14 to 19 are diagrams for explaining still another example of the configuration of the optical deflection unit. In the above, the observation device 10b includes the optical deflection unit 160, but the observation device 10b may include any one of the optical deflection units 170 to 220 shown in FIGS. 14 to 19 instead of the optical deflection unit 160.

[0063] The light deflection unit 170 shown in FIG. 14 includes a support 171 having a surface 175, a reflecting surface 172 formed on the support 171, and a linear prism plate 173. The light deflection unit 170 is different from the light deflection unit 160 in that the linear prism plate 173 is oriented in a direction that is upside down compared to the linear prism plate 163 of the light deflection unit 160. That is, in the light deflection unit 170, a plurality of surfaces 174 that function as refracting surfaces are provided close to the reflecting surface 172, and a horizontal surface 176 faces the transmission window 11. The inclination direction of the surface 174 is opposite to the inclination direction of the surface 164 of the light deflection unit 160. If the surface 164 is inclined downward with respect to the horizontal direction, the surface 174 is inclined upward with respect to the horizontal direction.

[0064] Even if the observation device 10b includes the optical deflection unit 170 instead of the optical deflection unit 160, as shown in FIG. 14, each of the surfaces 174 acts on light in the same manner as the surface 164 shown in FIG. 12, so that an optical image of the sample S can be formed by the light deflected by the optical deflection unit 170 at an output angle θex larger than the incident angle θin. Furthermore, in addition to the surface 174, the surface 176 also acts as a refracting surface that increases the output angle θex with respect to the incident angle θin, so that a larger magnitude angle difference can be generated than in the optical deflection unit 160. Therefore, even if the observation device 10b includes the optical deflection unit 170, the observation device 10b according to this embodiment can visualize the sample S with high contrast, and can exhibit high observation performance regardless of the culture vessel that contains the sample S. Therefore, it is possible to observe a sample contained in any culture vessel, not limited to the standard culture vessel C, well. Also, like the case including the optical deflection unit 160, the thickness of the optical deflection unit 170 can be made thin, and the sample S can be observed under the same conditions regardless of the observation position. Furthermore, in the optical deflection unit 170, the multiple surfaces 174 are provided inside the optical deflection unit 170 and are not exposed to the outside. As a result, only the flat surfaces need to be cleaned, which makes cleaning of the optical deflection unit 170 easy.

[0065] 15 includes a support 181 having a surface 182 and a surface 183, and a linear prism plate 184 supported at a distance from the support 181. Note that the linear prism plate 184 may be substantially the same as the linear prism plate 163, and includes a surface 186 which is a plurality of refracting surfaces aligned in a direction intersecting the optical axis, and a surface 185 which faces the surface 183.

[0066] In the optical deflection unit 180, the surface 186 acts in the same manner as the surface 164, thereby generating an angle difference between the incident angle θin and the exit angle θex. Moreover, the optical deflection unit 180 is provided with a plurality of reflecting surfaces (surfaces 185, 183, and 182) that generate Fresnel reflection, instead of a reflecting surface including a mirror. These reflecting surfaces act in the same manner as the reflecting surface 162, thereby deflecting light toward the transmission window 11.

[0067] Therefore, even when the optical deflection unit 180 is included, the observation device 10b according to this embodiment can visualize the sample S with high contrast, and the observation device 10b can demonstrate high observation performance regardless of the culture vessel in which the sample S is contained. Therefore, it is possible to observe a sample contained in any culture vessel, not limited to the standard culture vessel C, well. In addition, the optical deflection unit 180 can be made thin, and the sample S can be observed under the same conditions regardless of the observation position, similar to the case where the optical deflection unit 160 is included. Furthermore, since the optical deflection unit 180 has a structure that reflects light by Fresnel reflection, the observer can visually observe the culture vessel C through the optical deflection unit 180 from above the optical deflection unit 180.

[0068] 16 includes a support 191 having a surface 195, a reflecting surface 192 formed on the support 191, and a linear prism plate 193. Note that the optical deflection unit 190 differs from the optical deflection unit 170 in that the reflecting surface 192 is a partial reflecting mirror or splitter, such as a half mirror, that reflects a portion of the incident light and transmits the remainder. In other respects, the optical deflection unit 190 is similar to the optical deflection unit 170.

[0069] Therefore, even when the optical deflection unit 190 is included, the observation device 10b according to this embodiment can visualize the sample S with high contrast, similarly to the case where the optical deflection unit 170 is included, and the observation device 10b can exhibit high observation performance regardless of the culture vessel in which the sample S is contained. Therefore, it is possible to observe a sample contained in any culture vessel, not limited to the standard culture vessel C, well. In addition, similarly to the case where the optical deflection unit 170 is included, the thickness of the optical deflection unit 190 can be made thin, and the sample S can be observed under the same conditions regardless of the observation position. Furthermore, since the optical deflection unit 190 has a structure that reflects light by a partial reflection mirror, the observer can visually observe the culture vessel C through the optical deflection unit 190 from above the optical deflection unit 190. Specifically, when the operator wishes to visually check the state of the culture container C from outside the incubator 20 through a transparent window of the incubator while the culture container C is placed inside the incubator 20, even if the culture container C and the optical deflection unit 190 are placed at the bottom inside the incubator 20 (at a position where the user's line of sight is covered by the optical deflection unit), the operator can visually check the culture container C through the optical deflection unit 190, thereby improving the operator's work efficiency.

[0070] 17 includes a linear prism plate 201 on which a reflecting surface 202 is formed. In addition to the reflecting surface 202, the linear prism plate 201 includes surfaces 203 which are a plurality of refracting surfaces aligned in a direction intersecting the optical axis. Each of the surfaces 203 is a refracting surface inclined with respect to the optical axis for refracting light incident on the optical deflection unit 200, and is provided on the optical path between the reflecting surface 202 and the transmission window 11.

[0071] The optical deflection unit 200 can generate an angular difference between the incident angle θin and the exit angle θex by having the reflective surface 202 formed on the linear prism plate 201 act in the same manner as the reflective surface 162 formed on the support 161 of the optical deflection unit 160, and the surface 203 act in the same manner as the surface 164 of the optical deflection unit 160.

[0072] Therefore, even when the optical deflection unit 200 is included, the observation device 10b according to this embodiment can visualize the sample S with high contrast, similarly to the case where the optical deflection unit 160 is included, and the observation device 10b can exhibit high observation performance regardless of the culture vessel in which the sample S is contained. Therefore, it is possible to observe a sample contained in any culture vessel, not limited to the standard culture vessel C, well. In addition, by forming a reflecting surface on the surface of the linear prism plate 201, the thickness of the optical deflection unit 200 can be further reduced. Note that, like the case where the optical deflection unit 160 is included, the sample S can be observed under the same conditions regardless of the observation position.

[0073] 18 includes a linear prism plate 211. The linear prism plate 211 includes reflecting surfaces 212, which are a plurality of reflecting surfaces aligned in a direction intersecting the optical axis, and surfaces 213, which are refractive surfaces. Each of the reflecting surfaces 212 is a reflecting surface inclined with respect to the optical axis, and in the optical deflection unit 210, by reflecting light at the reflecting surfaces 212, it is possible to generate an angle difference between the incident angle θin and the output angle θex, and further, the angle difference can be widened by the surfaces 213.

[0074] Therefore, even when the optical deflection unit 210 is included, the observation device 10b according to this embodiment can visualize the sample S with high contrast, similarly to the case where the optical deflection unit 160 is included, and the observation device 10b can exhibit high observation performance regardless of the culture vessel in which the sample S is contained. Therefore, it is possible to satisfactorily observe a sample contained in any culture vessel, not limited to the standard culture vessel C. Also, similarly to the case where the optical deflection unit 200 is included, by forming a reflective surface on the surface of the linear prism plate 211, the thickness of the optical deflection unit 210 can be further reduced, and the sample S can be observed under the same conditions regardless of the observation position.

[0075] The light deflection unit 220 shown in FIG. 19 includes a linear prism plate 221. The linear prism plate 221 includes a reflecting surface 222, which is a plurality of reflecting surfaces aligned in a direction intersecting the optical axis, and a surface 223. The light deflection unit 220 is similar to the light deflection unit 210, except that the reflecting surface 222 is provided to face the transmission window 11. The inclination direction of the reflecting surface 222 is also the same as the inclination direction of the reflecting surface 212 of the light deflection unit 210. That is, if the reflecting surface 212 is inclined upward with respect to the horizontal direction, the reflecting surface 222 is inclined upward with respect to the horizontal direction. In the light deflection unit 220, it is possible to generate an angle difference between the incident angle θin and the output angle θex by reflecting light at the reflecting surface 222.

[0076] Therefore, even when the optical deflection unit 220 is included, the observation device 10b according to this embodiment can visualize the sample S with high contrast, similar to the case where the optical deflection unit 210 is included, and the observation device 10b can exhibit high observation performance regardless of the culture vessel in which the sample S is contained. Therefore, it is possible to satisfactorily observe a sample contained in any culture vessel, not limited to the standard culture vessel C. Also, similar to the case where the optical deflection unit 210 is included, the thickness of the optical deflection unit 220 can be further reduced by forming a reflective surface on the surface of the linear prism plate 221, and the sample S can be observed under the same conditions regardless of the observation position.

[0077] [Fourth embodiment] FIG. 20 is a diagram illustrating the configuration of the observation device 10c according to this embodiment. FIG. 21 is a diagram for explaining yet another example of the configuration of the optical deflection unit. As described above with reference to FIG. 3, when the sample S is visualized by relying on the reflected light on the upper surface of the culture vessel, the contrast decreases if the height of the culture vessel is too high. However, it is not necessarily the case that the lower the height of the culture vessel, the better. If the height of the culture vessel is too low, the reflected light on the upper surface of the culture vessel cannot illuminate a sufficient range, and the entire field of view of the imaging unit 15 cannot be observed. In particular, when an imaging unit 15 having a relatively low observation magnification with a wide field of view is used, this problem occurs significantly. The observation device 10c according to this embodiment solves such technical problems by using the optical deflection unit 230.

[0078] The observation device 10c according to this embodiment differs from the observation device 10 according to the first embodiment in that it includes an optical deflection unit 230 shown in Fig. 21 instead of the optical deflection unit 100. More specifically, the observation device 10c and the optical deflection unit 230 differ from the observation device 10 and the optical deflection unit 100 in that the exit angle θex from the optical deflection unit 230 is made smaller than the incident angle θin to the optical deflection unit 230.

[0079] The light deflection unit 230 shown in FIG. 21 includes a support 231 having a surface 233, a reflecting surface 232 formed on the support 231, and a linear prism plate 234. The light deflection unit 230 is different from the light deflection unit 170 in that the linear prism plate 234 is oriented in a direction that is the left-right inversion of the linear prism plate 173 of the light deflection unit 170. That is, in the light deflection unit 230, a plurality of surfaces 235 that function as refracting surfaces are provided close to the reflecting surface 232, and a horizontal surface 236 is oriented toward the transmission window 11. The inclination direction of the surface 235 is opposite to the inclination direction of the surface 174 of the light deflection unit 170. If the surface 174 is inclined upward with respect to the horizontal direction, the surface 235 is inclined downward with respect to the horizontal direction. This difference in orientation creates a difference in that surface 174 acts on light to increase the exit angle θex relative to the incident angle θin, whereas surface 235 acts on light to decrease the exit angle θex relative to the incident angle θin.

[0080] In the observation device 10c according to this embodiment, by reducing the exit angle θex with respect to the incident angle θin in the optical deflection unit 230, it is possible to ensure a sufficient illumination range even when the height of the optical deflection unit 230 is lowered to match the culture container C2. Therefore, according to the observation device 10c, the performance of the observation device 10c can be fully utilized, and the entire field of view can be observed while maintaining high contrast. Furthermore, since the height of the optical deflection unit 230 can be reduced, the entire observation device 10c can be made smaller.

[0081] In the above, an example in which the observation device 10c includes the optical deflection unit 230 has been described, but the observation device 10c may include another optical deflection unit that reduces the output angle θex with respect to the incident angle θin, instead of the optical deflection unit 230. Such an optical deflection unit may be, for example, an optical deflection unit whose refracting surface is inclined in the opposite direction to an optical deflection unit whose refracting surface increases the output angle θex with respect to the incident angle θin, such as the optical deflection unit 230. Also, the optical deflection unit may be an optical deflection unit whose reflective surface is inclined in the opposite direction to an optical deflection unit whose refracting surface increases the output angle θex with respect to the incident angle θin. Furthermore, a combination of these may be used. Also, such an optical deflection unit may be an optical deflection unit whose refracting surface is inclined in the same direction as an optical deflection unit whose refracting surface increases the output angle θex with respect to the incident angle θin, such as the optical deflection unit 240 shown in FIG. 22. Also, the optical deflection unit whose reflective surface is inclined in the same direction as an optical deflection unit whose refracting surface increases the output angle θex with respect to the incident angle θin.

[0082] In addition, in Figure 20, an observation device 10c is shown as an example that includes an optical deflection unit 230 that reduces the exit angle θex relative to the incident angle θin, as a configuration that can ensure a sufficiently wide field of view even when the height of the optical deflection unit is lowered to match the height of the culture vessel and configured compactly. However, an observation device including an optical deflection unit that reduces the exit angle θex relative to the incident angle θin may be used when using a culture vessel C3 with a small area for containing a sample (for example, a multi-well plate with a small area per well), as in the observation device 10d shown in Figure 22.

[0083] When a multi-well plate is used, if the light deflected by the light deflection unit has a large exit angle, it will be blocked by the side of the well before entering the imaging unit 15. On the other hand, a certain distance is required between the light source unit 14 and the imaging unit 15, and there is a limit to adjusting this distance to reduce the incident angle to the light deflection unit. For this reason, in order to achieve a small exit angle, it is desirable to use a configuration that achieves an exit angle smaller than the incident angle, such as the light deflection unit 240, and when a multi-well plate is used, the observation device 10d having the light deflection unit 240 is preferable.

[0084] Specifically, in the observation device 10d shown in Fig. 22, the illumination light emitted from the light source unit 14 passes through a gap between the well containing the sample to be observed and the imaging unit 15, travels across the optical axis of the imaging unit 15 (optical system 18), and enters the optical deflection unit 240 at a relatively large angle. The illumination light that entered the optical deflection unit 240 is then refracted by the linear prism plate 244 so that the angle with respect to the optical axis becomes smaller, and is reflected by the reflecting surface 242 formed on the support 241. The illumination light reflected by the reflecting surface 242 is refracted by the surface of the linear prism plate 244 in a direction approaching the optical axis, and exits at a smaller angle with respect to the optical axis of the imaging unit 15 (optical system 18) than when it entered.

[0085] In this way, by making the illumination light incident at a large angle with respect to the normal to the surface of the linear prism plate 244 and largely refracting the illumination light by the linear prism plate 244, the angle with respect to the optical axis of the illumination light can be made small and it can be returned to the original direction. The above-mentioned configuration that returns the illumination light to the original direction at a small angle makes it possible to return the illumination light to the optical system 18 from a narrow gap between the imaging unit 15 and the well without interfering with the side surface of the container, even in the case of a culture container with a small area of ​​the portion that contains the sample. For this reason, it is particularly suitable when a culture container such as a multi-well plate is used.

[0086] The above-mentioned embodiments are specific examples shown to facilitate understanding of the invention, and the present invention is not limited to these embodiments. Modifications of the above-mentioned embodiments and alternative forms that replace the above-mentioned embodiments may be included. That is, each embodiment can have its components modified within the scope of its purpose and scope. In addition, new embodiments can be implemented by appropriately combining multiple components disclosed in one or more embodiments. In addition, some components may be deleted from the components shown in each embodiment, or some components may be added to the components shown in the embodiment. Furthermore, the processing procedures shown in each embodiment may be performed in a different order as long as there is no contradiction. That is, the observation device, the optical deflection unit, and the image forming method of the present invention can be variously modified and changed within the scope of the claims.

[0087] In the above-described embodiment, the light deflection unit has a reflecting surface, but the light deflection unit may use a diffraction grating, for example, a reflective diffraction grating, instead of a reflecting surface. The reflective diffraction grating may largely deflect the light incident on the light deflection unit. By using a diffraction grating, it is possible to reduce the thickness of the light deflection unit compared to the case where the light deflection unit has a largely inclined reflecting surface.

[0088] In the above-mentioned embodiment, an example was described in which the culture vessel has a specific shape such as a dish or a flask, but since the sample can be visualized without relying on reflected light on the upper surface of the culture vessel, the culture vessel may have a variety of shapes, for example, a transparent or semi-transparent bag. In particular, when a bag whose container shape can be flexibly changed is used, a member for positioning the bag may be provided on the housing or the light deflection unit. This allows stable observation.

[0089] FIG. 23 is a diagram for explaining a method of using the optical deflection unit. In the above-mentioned embodiment, an example in which the optical deflection unit is included in the observation device has been shown, but the optical deflection unit may not be a component of the observation device as long as it is used together with the observation device. For example, as shown in FIG. 23, the optical deflection unit 250 may be an auxiliary device that does not constitute the observation device 10, and may be distributed on the market separately from the observation device 10. The optical deflection unit 250 may be used in a state in which it is placed on the upper surface of the culture vessel C, and can guide the light emitted from inside the housing 12 to the outside of the housing 12 at a desired angle again into the housing 12, similar to the optical deflection unit 230 from the optical deflection unit 100. The optical deflection unit 250 may be used as an auxiliary device used when stacking a plurality of culture vessels C.

[0090] In this specification, the expression "based on A" does not mean "based only on A", but also means "based at least on A" and further means "based at least partially on A". That is, "based on A" may be based on B in addition to A, or may be based on a part of A.

[0091] In this specification, the term "substantially" means close enough to the extent that the advantage of the characteristic modified by the term is exhibited. For example, the expression "substantially parallel" does not mean completely parallel, but means approximately parallel to the extent that the advantage obtained by parallelism is exhibited.

[0092] As used herein, the terms "first," "second," and the like, modifying a noun do not limit the quantity or order of the elements described by the noun. These terms are used to distinguish between two or more elements, not less, not more. Thus, the specification of a "first" and a "second" element does not imply that the "first" element precedes the "second" element, nor does it negate the presence of a "third" element. [Explanation of symbols]

[0093] 1 system, 10, 10a, 10b, 10c, 10d observation device, 11 transparent window, 12 housing, 14 light source unit, 15 imaging unit, 16 light source, 17 diffusion plate, 18 optical system, 19 imaging element, 20 incubator, 30 control device, 40, 50 client terminal, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210 , 220, 230, 240, 250···Light deflection unit, 102, 113, 123, 132, 142, 152, 162, 172, 192, 202, 212, 222, 232, 242···Reflecting surface, 143, 153···Prism, 163, 173, 184, 193, 201, 211, 221, 234, 244···Linear prism plate, C, C1, C2, C3···Culture vessel, L1, L2···Light beam, P···Point, PL···Pupil, S···Sample

Claims

1. A housing having a transmission window; an imaging unit accommodated in the housing, the imaging unit including an imaging element and an optical system that collects light that is incident on the housing by transmitting through the transmission window to form an image of a sample in a container placed on the transmission window on the imaging element; a light source unit accommodated in the housing, the light source unit emitting light to the outside of the housing without passing through the optical system; an optical deflection unit that deflects light emitted from the light source unit to the outside of the housing in a first direction toward the transmission window, wherein an emission angle that is an angle between the first direction and an optical axis of the optical system is different from an incidence angle that is an angle between a second direction in which the light emitted to the outside of the housing is incident on the optical deflection unit and the optical axis; the optical deflection unit includes at least one reflecting surface that reflects light incident on the optical deflection unit, and at least one refracting surface that refracts the light incident on the optical deflection unit; The at least one refractive surface is disposed on an optical path between the at least one reflective surface and the transmission window. An observation device characterized by:

2. A housing having a transmission window; an imaging unit accommodated in the housing, the imaging unit including an imaging element and an optical system that collects light that is incident on the housing by transmitting through the transmission window to form an image of a sample in a container placed on the transmission window on the imaging element; a light source unit accommodated in the housing, the light source unit emitting light to the outside of the housing without passing through the optical system; an optical deflection unit that deflects light emitted from the light source unit to the outside of the housing in a first direction toward the transmission window, wherein an emission angle that is an angle between the first direction and an optical axis of the optical system is different from an incidence angle that is an angle between a second direction in which the light emitted to the outside of the housing is incident on the optical deflection unit and the optical axis; the optical deflection unit includes at least one reflecting surface that reflects light incident on the optical deflection unit, and a prism plate having a plurality of refracting surfaces aligned in a direction intersecting the optical axis; Each of the plurality of refractive surfaces is a refracting surface inclined with respect to the optical axis for refracting light incident on the optical deflection unit; a light path between the at least one reflecting surface and the transmission window; An observation device characterized by:

3. The observation device according to claim 1 or 2, A bundle of rays consisting of light deflected in the first direction by the optical deflection unit and passing through a point on the sample is distributed across an outer edge of the pupil of the optical system on a pupil plane of the optical system. An observation device characterized by:

4. The observation device according to claim 1 or 2, The exit angle is greater than the entrance angle. An observation device characterized by:

5. The observation device according to claim 1 or 2, The exit angle is smaller than the entrance angle. An observation device characterized by:

6. The observation device according to any one of claims 1 to 5, The at least one reflecting surface includes a reflecting surface tilted with respect to the optical axis. An observation device characterized by:

7. The observation device according to any one of claims 1 to 6, The optical deflection unit further includes an adjustment unit that adjusts an angle of the at least one reflecting surface with respect to the optical axis. An observation device characterized by:

8. The observation device according to any one of claims 1 to 7, The reflecting surface inclined with respect to the optical axis includes a metal thin film mirror or a dielectric multilayer mirror formed on a surface of a substrate. An observation device characterized by:

9. The observation device according to any one of claims 1 to 8, 11. An observation apparatus according to claim 10, wherein the at least one reflective surface includes a plurality of inclined surfaces aligned in a direction intersecting the optical axis.

10. The observation device according to any one of claims 1 to 9, The at least one reflective surface is a partially reflective mirror or splitter that reflects a portion of the incident light and transmits the remainder. An observation device characterized by:

11. The observation device according to any one of claims 1 to 10, the optical deflection unit further includes a first surface that does not face the transmission window, At least a portion of the first surface is a plane parallel to the transmission window. An observation device characterized by:

12. Emitting light from inside the housing to outside the housing; The light emitted to the outside of the housing is deflected in a first direction toward a transmission window of the housing by a light deflection unit; light that has passed through the transmission window and entered the housing is collected by an optical system within the housing to form an image of the sample in the container placed on the transmission window on an imaging element; an exit angle, which is an angle between the first direction and an optical axis of the optical system, is different from an incident angle, which is an angle between a second direction in which the light emitted to the outside of the housing is incident on the optical deflection unit and the optical axis; the optical deflection unit includes at least one reflecting surface that reflects light incident on the optical deflection unit, and at least one refracting surface that refracts the light incident on the optical deflection unit; The at least one refractive surface is disposed on an optical path between the at least one reflective surface and the transmission window.

1. An image forming method comprising:

13. A light emitting device for emitting light from inside a housing to outside the housing, The light emitted to the outside of the housing is deflected in a first direction toward a transmission window of the housing by a light deflection unit; light that has passed through the transmission window and entered the housing is collected by an optical system within the housing to form an image of the sample in the container placed on the transmission window on an imaging element; an exit angle, which is an angle between the first direction and an optical axis of the optical system, is different from an incident angle, which is an angle between a second direction in which the light emitted to the outside of the housing is incident on the optical deflection unit and the optical axis; the optical deflection unit includes at least one reflecting surface that reflects light incident on the optical deflection unit, and a prism plate having a plurality of refracting surfaces aligned in a direction intersecting the optical axis; Each of the plurality of refractive surfaces is a refracting surface inclined with respect to the optical axis for refracting light incident on the optical deflection unit; a light path between the at least one reflecting surface and the transmission window; 1. An image forming method comprising:

Images