JP2020030372A - Polarization observation device - Google Patents

Abstract

To detect an observation object for causing small retardation according to a difference in a hue.SOLUTION: A polarization observation device 1 includes: a light source S and a polarizer PO for generating complete polarization applied to a retarder RE; an analyzer AN for transmitting a polarization component having a specific vibration direction; a phase plat PP disposed on an optical path between the polarizer PO and the analyzer AN; and a color filter CC. The phase plate PP gives a predetermined phase difference between two polarization components having mutually orthogonal vibration directions, and converts an interference color of transmission light transmitted through the analyzer AN to a sharp color according to a predetermined phase difference. The color filter CC brings an interference color of transmission light through the analyzer AN close to an achromatic color.SELECTED DRAWING: Figure 7

Description

  The disclosure herein relates to a polarization observation device.

  Microinsemination is known as one of the markets for inverted microscopes. Microinsemination is a method of fertilizing sperm and eggs under a microscope. Microinsemination is generally performed by an intracytoplasmic sperm injection (ICSI) method in which sperm is directly injected into an egg by piercing a micropipette containing sperm into an egg fixed with a holding pipette.

  By the way, the ovum has an intracellular structure called a spindle. The spindle has birefringence, and when the egg matures, the retardation generated in the spindle in the egg increases, and as a result, the spindle can be observed by the polarization observation method.

  If the spindle is damaged, the egg will not fertilize. For this reason, in recent microscopic fertilization, spindle observation using a polarization observation method is mainly performed for the purpose of determining the maturity of an egg and avoiding damage to the spindle in ICSI. Techniques related to spindle observation are described in, for example, Patent Documents 1 and 2.

  Patent Literature 1 describes an observation apparatus that performs observation by switching between a polarization observation method, a differential interference observation method, and a relief contrast observation method during microinsemination. In the polarization observation method performed by the observation device described in Patent Literature 1, the contrast can be adjusted by using a compensator.

  Patent Literature 2 proposes a polarization observation method for observing a weakly birefringent material that causes a retardation of less than 100 nm. In the polarization observation method, an interference color corresponding to retardation generated between the polarizer and the analyzer is observed. Among these interference colors, a color whose hue changes greatly with a change in retardation is called a sensitive color, and a polarization observation method using the sensitive color is called a sensitive color observation method. Patent Literature 2 discloses a technique of observing a weakly birefringent material by increasing retardation sensitivity in a sensitive color observation method.

International Publication No. 2012/150689 U.S. Pat. No. 5,559,630

  The retardation of the spindle is about 5 nm even when the egg is fully matured. In contrast, in a general sensitive color observation method, as shown in FIG. 1, a change in hue angle Δh (that is, retardation sensitivity) with respect to a change in retardation ΔR of 5 nm generated in an object to be observed (retarder) is 5 °. Only about 10 ° from More specifically, in the orthogonal Nicol sensitive color observation method, Δh / ΔR is about 5 °. Under these conditions, it is estimated that the retardation that can be detected by a human as a change in hue is about 20 nm. Further, even in the parallel Nicol sensitive color observation method, Δh / ΔR is about 10 °. Under these conditions, it is estimated that the retardation that can be detected by a human as a change in hue is about 10 nm. Note that the hue angle refers to a hue angle in the L * a * b * color space.

  In the technique described in Patent Document 2, the change Δh of the hue angle with respect to the change ΔR of the retardation of 5 nm is about 25 °. However, near the retardation of 0 nm, the brightness of the interference color becomes extremely dark. For this reason, the retardation that can be detected by a human as a change in hue is estimated to be about 10 nm.

  Therefore, in the sensitive color observation method of the related art, it is extremely difficult to detect an observation target that causes a small retardation, such as a spindle, due to a difference in hue.

  In view of the above circumstances, an object according to one aspect of the present invention is to provide a technique for detecting an observation target that causes small retardation based on a difference in hue.

  The polarization observation device according to one aspect of the present invention is a polarization generation unit that generates completely polarized light that irradiates an observation target, an analysis unit that transmits a polarization component having a specific vibration direction, the polarization generation unit, and the polarization generation unit. A phase delay means disposed on an optical path between the light analyzing means and providing a predetermined phase difference between two polarization components having vibration directions orthogonal to each other, wherein interference of transmitted light transmitted through the light analyzing means is provided. The image processing apparatus includes: a phase delay unit that converts a color into a sharp color by the predetermined phase difference; and a saturation adjustment unit that brings an interference color of the transmitted light closer to an achromatic color.

  According to the above aspect, it is possible to detect an observation target that causes small retardation based on a difference in hue.

FIG. 9 is a diagram showing retardation sensitivity in a conventional sensitive color observation method. FIG. 1 is a diagram illustrating a configuration of a polarization observation device 100. FIG. 2 is a diagram showing an axial arrangement in the polarization observation device 100. FIG. 3 is a diagram illustrating a relationship between retardation and interference colors in the polarization observation device 100. FIG. 2 is a diagram illustrating a configuration of a polarization observation device 200. FIG. 3 is a diagram showing an axial arrangement in the polarization observation device 200. FIG. 1 is a diagram illustrating a configuration of a polarization observation device 1 according to a first embodiment. FIG. 4 is a diagram illustrating a relationship between retardation and an interference color before applying a color filter CC in the polarization observation device 1. FIG. 3 is a diagram illustrating a relationship between retardation and interference colors after applying a color filter CC in the polarization observation device 1. FIG. 3 is a diagram illustrating a relationship between retardation and saturation of an interference color in the polarization observation device 1. FIG. 2 is a diagram illustrating retardation sensitivity of the polarization observation device 1. It is the figure which illustrated the configuration of the polarization observation device 2 according to the second embodiment. FIG. 3 is a diagram illustrating an axial arrangement in the polarization observation device 2. FIG. 4 is a diagram illustrating a relationship between retardation and interference colors in the polarization observation device 2. FIG. 4 is a diagram illustrating a relationship between retardation and saturation of an interference color in the polarization observation device 2. FIG. 3 is a diagram illustrating retardation sensitivity of the polarization observation device 2. It is a figure which illustrated the composition of the polarization observation device 3 concerning a 3rd embodiment. It is the figure which illustrated the configuration of the polarization observation device 4 according to the fourth embodiment. It is a figure which illustrated the composition of the polarization observation device 5 concerning a 5th embodiment. FIG. 3 is a diagram illustrating an axial arrangement in a polarization observation device 5. It is a figure which illustrated the composition of the polarization observation device 6 concerning a 6th embodiment. It is the figure which illustrated the configuration of the polarization observation device 7 according to the seventh embodiment. FIG. 3 is a diagram showing an axial arrangement in a polarization observation device 7.

  FIG. 2 is a diagram illustrating the configuration of the polarization observation device 100. FIG. 3 is a diagram showing the axial arrangement in the polarization observation device 100. FIG. 4 is a diagram illustrating a relationship between retardation and interference colors in the polarization observation device 100. First, the polarization observation method will be described with reference to FIGS.

  The polarization observation device 100 illustrated in FIG. 2 is a device that visualizes retardation generated in an object. The observation object of the polarization observation device 100 is an object having birefringence, and is called a retarder in the sense that it causes retardation. In this specification, the retardation generated by the retarder is simply referred to as the retarder retardation.

  As shown in FIG. 2, the polarization observation apparatus 100 used in the polarization observation method includes at least a polarizer PO and an analyzer AN on an optical axis AX connecting the light source S and the eyes E of the observer. Then, observation using a polarization observation method (hereinafter, referred to as polarization observation) is performed in a state where the retarder RE for causing retardation is disposed between the polarizer PO and the analyzer AN. Although not shown, a condenser lens is arranged between the polarizer PO and the retarder RE, and an objective lens is arranged between the retarder RE and the analyzer AN.

  The light source S is a light source including at least light in the visible region, and is, for example, a halogen lamp, a tungsten lamp, a white LED, or the like. In polarized light observation, interference colors are observed when light of different wavelengths interferes with each other. For this reason, it is desirable that the light source S is a white light source that emits white light in which light in the visible region is mixed.

  Each of the polarizer PO and the analyzer AN is a polarization element that transmits a polarization component having a specific vibration direction. This specific vibration direction is a direction coincident with the transmission axis of the polarizing element. The polarizer PO is a polarizing element that is disposed closer to the light source S than the retarder RE and acts on illumination light that irradiates the retarder RE. The polarizer PO is an example of a polarization unit of the polarization observation device 100. The analyzer AN is a polarizing element that is disposed closer to the eye E than the retarder RE and acts on light transmitted through the retarder RE. The analyzer AN is an example of an analyzing unit of the polarization observation device 100.

  Further, the light source S and the polarizer PO are an example of a polarization generation unit of the polarization observation device 100 that generates perfect polarization for irradiating the retarder RE that is the observation target. In this example, the fully polarized light is linearly polarized light and includes light in the visible range.

  In the orthogonal Nicol observation method, which is the most basic polarization observation method, as shown in FIG. 3A, the polarizer PO and the analyzer AN are arranged such that the transmission axis of the polarizer PO and the transmission axis of the analyzer AN are orthogonal to each other. Is done. The retarder RE is arranged such that the slow axis of the retarder RE and the transmission axis of the polarizer PO form an angle of 45 degrees. In this configuration, if no retardation occurs in the optical path between the polarizer PO and the analyzer AN, the light blocked by the analyzer AN will pass through the analyzer AN due to the retardation of the retarder RE.

  For this reason, in the orthogonal Nicol observation method, an interference color corresponding to the retardation of the retarder RE is observed, and as a result, the retarder RE can be recognized by a difference in color. The interference color in the orthogonal Nicol observation method changes on the chromaticity diagram as shown in FIG. 4A according to the retardation of the retarder RE. Here, the interference color is represented by coordinates in the L * a * b * color space established by CIE1976. The coordinates in the rectangular coordinate system with a * and b * as axes are called chromaticity, the distance from the origin of the rectangular coordinate system is called saturation C, and the angle from the a * axis in the rectangular coordinate system is called hue angle h . The saturation C is a numerical value representing the vividness of the color, and the hue angle h is a numerical value representing the hue.

  In the parallel Nicol observation method, which is also a basic polarization observation method, as shown in FIG. 3B, the polarizer PO and the analyzer AN are arranged such that the transmission axis of the polarizer PO and the transmission axis of the analyzer AN are parallel. Is done. The retarder RE is arranged such that the slow axis of the retarder RE and the transmission axis of the polarizer PO form an angle of 45 degrees. In this configuration, if no retardation occurs in the optical path between the polarizer PO and the analyzer AN, the light transmitted through the analyzer AN is blocked by the analyzer AN due to the retardation of the retarder RE.

  Therefore, in the parallel Nicol observation method, similarly to the orthogonal Nicol observation method, an interference color corresponding to the retardation of the retarder RE is observed, and as a result, the retarder RE can be recognized by a difference in color. Note that the interference color in the parallel Nicol observation method changes on the chromaticity diagram as shown in FIG. 4B according to the retardation of the retarder RE.

  Thus, in the polarization observation method, when the retardation of the retarder RE is X, the background portion in the visual field is represented by a color having a chromaticity specified by R = 0 nm, and the retarder RE is specified by R = Xnm. Chromaticity. Therefore, the retarder RE can be observed depending on the difference between the color of R = 0 nm and the color of R = Xnm.

  However, in the polarization observation device 100, when the retardation of the retarder RE is small, the difference between the color of R = 0 nm and the color of R = Xnm is also small, so that it is difficult to distinguish the retarder RE from the background portion. When observing such a retarder RE having a small retardation, a sensitive color observation method, which is a polarization observation method using a sensitive color, is preferable.

  A sharp color is an interference color whose hue changes greatly with a change in retardation. In FIG. 4A and FIG. 4B, points at which the retardation differs by a fixed amount are plotted, but the chromaticity differences between the points are not the same. For example, referring to FIG. 4A in which points having different retardations by 50 nm are plotted, it can be seen that in the orthogonal Nicol observation method, the interference color becomes the most sensitive sharp color near 550 nm. That is, the chromaticity changes the most with respect to the change in the retardation, and as a result, the hue also changes greatly. Also, referring to FIG. 4B in which the points where the retardations differ by 20 nm are plotted, it can be seen that in the parallel Nicol observation method, the interference color becomes the most sensitive and sensitive color near 280 nm. That is, the chromaticity changes the most with respect to the change in the retardation, and as a result, the hue also changes greatly.

  FIG. 5 is a diagram illustrating the configuration of the polarization observation device 200. FIG. 6 is a diagram showing the axial arrangement in the polarization observation device 200. Hereinafter, the sensitive color observation method will be described with reference to FIGS.

  The polarization observation device 200 illustrated in FIG. 5 is a polarization observation device that observes the retarder RE in a sharp color. The polarization observation device 200 differs from the polarization observation device 100 in that a phase plate PP is provided on the optical axis AX between the polarizer PO and the analyzer AN. The other points are the same as those of the polarization observation device 100. The phase plate PP is an example of a phase delay unit of the polarization observation device 200.

  The phase plate PP is an optical element that generates a predetermined retardation, and converts an interference color of transmitted light transmitted through the analyzer AN into a sharp color by the predetermined retardation. The predetermined retardation generated by the phase plate PP can be converted into a predetermined phase difference using the reference wavelength of the phase plate PP. Therefore, the phase plate PP is an optical element that gives a predetermined phase difference between two polarization components having vibration directions orthogonal to each other, and the interference color of the transmitted light transmitted through the analyzer AN is sharpened by the predetermined phase difference. It is also an optical element that converts color. In many cases, the predetermined retardation generated by the phase plate PP has wavelength dispersion, and the predetermined phase difference generated by the phase plate PP also has wavelength dispersion. Further, in the present specification, the phase difference is obtained by standardizing the retardation with a reference wavelength. The unit of retardation is length, and the unit of phase difference is wave number or angle.

  As shown in FIGS. 6A and 6B, the phase plate PP is parallel to the slow axis of the retarder RE, that is, in any of the orthogonal Nicol observation method and the parallel Nicol observation method. , At an angle of 45 degrees with the transmission axis of the polarizer PO.

  With this arrangement, the retardation generated by the retarder RE and the retardation generated by the phase plate PP have the same effect on the interference color. Therefore, in the sensitive color observation method, the retardation of the phase plate PP is selected such that the total of the retardation of the retarder RE and the retardation of the phase plate PP is about 550 nm in the orthogonal Nicol observation method and about 280 nm in the parallel Nicol observation method. Is desirable.

  According to the polarization observation device 200, the retarder RE can be observed in a sensitive color using the sensitive color observation method. For this reason, even when the retardation of the retarder RE is small, the difference in the retardation between the background portion and the retarder RE appears as a large hue difference, so that the retarder RE with a small retardation can be observed. Specifically, it is possible to observe a retarder RE with a small retardation of about 20 nm by the orthogonal Nicol sensitive color observation method and about 10 nm by the parallel Nicol sensitive color observation method.

  Hereinafter, embodiments of the present invention will be described. The polarization observation device according to the embodiment of the present invention has a common feature in that the polarization observation device includes a saturation adjustment unit that makes an interference color of transmitted light transmitted through the analyzer AN closer to an achromatic color.

  As shown in FIG. 4, in a sharp color, a change in chromaticity is large with respect to a change in retardation, and as a result, a hue is also greatly changed. Further, it should be noted that a sharp color has a high saturation. Considering that the saturation is represented by the distance from the origin of the coordinate system, it is clear that the larger the saturation, the smaller the change in the hue angle for a given change in chromaticity. From the above, the sensitive color observation method has room for further improvement in the efficiency of reflecting a change in chromaticity to a change in hue angle.

  The embodiment of the present invention greatly improves the ratio of the change of the hue angle to the change of the chromaticity by bringing the interference color closer to the achromatic color by the saturation adjusting means. In addition, since the human eye tends to have low sensitivity to chromaticity in a high-saturation region, the sensitivity to chromaticity can be improved by bringing the interference color closer to an achromatic color by the saturation adjusting means. it can. As a result, the retardation sensitivity is greatly improved, so that even a retarder that generates a small retardation, such as a spindle, can be detected as a change in hue.

  Note that the saturation adjusting means adjusts the saturation of the interference color to an achromatic color so that the saturation C in the L * a * b * color space is 20 or less in the background portion of the retarder RE, that is, in the portion where the retardation is 0 nm. Is desirable. By reducing the saturation to this extent, the hue can be sufficiently changed with respect to the chromaticity change, so that a change in the 5 nm retardation generated by the spindle can be detected by a human as a hue change. . A sufficiently large change in hue is, for example, a change between hues having hue angles different by 90 ° or more. If the hue changes by 90 ° or more, a human can reliably detect the hue. Therefore, it is desirable that the saturation adjustment unit brings the saturation of the interference color closer to an achromatic color so that the hue angle changes by 90 ° or more with respect to the change of the retardation of 5 nm.

[First Embodiment]
FIG. 7 is a diagram illustrating a configuration of the polarization observation device 1 according to the present embodiment. The polarization observation device 1 shown in FIG. 7 is a device for visualizing the retardation of the retarder RE. The polarization observation device 1 is different from the polarization observation device 200 shown in FIG. 5 in that a color filter CC is provided on an optical axis AX connecting the light source S and the eyes E of the observer. The other points are the same as those of the polarization observation device 200.

  The color filter CC is an optical filter having a predetermined spectral transmittance characteristic. The color filter CC is an example of a saturation adjustment unit of the polarization observation device 1 that makes an interference color of light transmitted by the analyzer AN closer to an achromatic color. More specifically, the color filter CC attenuates a part of the wavelength range of the incident light in accordance with the spectral intensity distribution of the incident light, thereby transmitting transmitted light more than when the polarization observation device 1 does not have the color filter CC. Reduce the saturation of the interference color.

  FIG. 8 is a diagram showing the relationship between retardation and interference color before applying the color filter CC in the polarization observation device 1. FIG. 9 is a diagram illustrating a relationship between retardation and interference colors after the application of the color filter CC in the polarization observation device 1. In FIGS. 8 and 9, the interference color generated by the retardation from 450 nm to 600 nm is regarded as a sensitive color.

  For example, if the polarizer PO and the analyzer AN are arranged in a crossed Nicols state and the phase plate PP has a retardation of about 450 to 500 nm, the chromaticity shown in FIG. The distribution can be shifted in the direction indicated by the solid line CC (B). Thereby, a chromaticity change indicated by a solid line CC (B) in FIG. 9 can be realized with respect to a change in retardation. If the phase plate PP has a retardation of about 500 nm to 550 nm, the chromaticity distribution shown in FIG. 8 is moved in the direction shown by the long broken line CC (G) by using the green color filter CC. Can be. Thereby, the chromaticity change indicated by the long broken line CC (G) in FIG. 9 can be realized with respect to the change in the retardation. Further, if the phase plate PP has a retardation of about 550 nm to 600 nm, the chromaticity distribution shown in FIG. 8 is moved in the direction shown by the short broken line CC (Y) by using the yellow color filter CC. Can be. Thus, a change in chromaticity indicated by a short broken line CC (Y) in FIG. 9 can be realized with respect to a change in retardation.

  The blue, green, and yellow color filters are color filters that attenuate wavelength ranges other than blue, green, and yellow, respectively. For example, a blue color filter is a color filter having the highest transmittance in the blue wavelength region.

  It is desirable that the phase plate PP minimize the saturation after applying the color filter CC by the retardation generated in the phase plate PP. For example, when the color filter CC is a blue color filter, the polarization observation device 1 includes the phase plate PP that generates the 488 nm retardation, thereby reducing the saturation of transmitted light to the minimum point MP. be able to. In this case, since the chromaticity changes along the solid line CC (B) from the minimum point MP due to the small retardation of the retarder RE, the hue angle greatly changes as compared with the case where there is no color filter CC.

  FIGS. 10A and 10B are diagrams showing the relationship between retardation and the saturation of the interference color in the polarization observation device 1. FIG. 10A shows the relationship in the orthogonal Nicol sensitive color observation method, and FIG. The relationship in the color observation method is shown. FIG. 11 is a diagram showing the retardation sensitivity of the polarization observation device 1. FIG. 11 (a) shows the retardation sensitivity in the orthogonal Nicol sensitive color observation method, and FIG. 11 (b) shows the retardation in the parallel Nicol sensitive color observation method. Shows the sensitivity.

  As shown in FIGS. 10A and 10B, by using a phase plate PP that generates an appropriate retardation in accordance with the color filter CC, the saturation of the interference color is reduced when the retardation of the retarder RE is around 0 nm. This can be minimized, and the saturation of the interference color can be greatly reduced as compared with the case where the color filter CC is not provided. As a result, as shown in FIGS. 11A and 11B, the retardation sensitivity can be greatly improved as compared with the case where there is no color filter CC. As a result, the retardation that can be detected by a human as a change in hue can be reduced to about 4 nm by the orthogonal Nicol sensitive color observation method and to about 2 nm by the parallel Nicol sensitive color observation method.

  Therefore, according to the polarization observation device 1 according to the present embodiment, it is possible to detect an observation target that causes a small retardation based on a difference in hue.

  In the present embodiment, the color filters CC are arranged between the light source S and the polarizer PO, but the arrangement of the color filters CC is not limited to this example. The color filter CC can be arranged at any position as long as it is arranged on AX between the light source S and the eye E.

  Further, in the present embodiment, the phase plate PP is arranged between the retarder RE and the analyzer AN, but the arrangement of the phase plate PP is not limited to this example. The phase plate PP can be arranged at any position as long as it is arranged on the AX between the polarizer PO and the analyzer AN.

  Further, in the present embodiment, the case where the phase plate PP has a desired retardation is illustrated, but the retardation of the phase plate PP may be different from the designed retardation due to a manufacturing error. In such a case, a compensator may be further provided on the optical axis AX. The compensator is an optical element that provides a variable phase difference between two polarization components having vibration directions orthogonal to each other, and is an example of a second phase delay unit of the polarization observation device 1. The compensator is, for example, a Senarmont compensator, a Berek compensator, a brace scaler compensator, or the like. By adjusting the retardation of the compensator, the saturation may be minimized while the retardation of the retarder RE is 0 nm. In particular, the brace scaler is advantageous in that the retardation can be adjusted more finely. Thereby, even if there is a manufacturing error in the retardation of the phase plate PP, the retarder RE can be detected with high retardation sensitivity.

  Note that the desired retardation of the phase plate PP is desirably n × λ when the polarizer PO and the analyzer AN are arranged so that their transmission axes are orthogonal to each other. When the polarizer PO and the analyzer AN are arranged such that their transmission axes are parallel to each other, it is preferable that the polarizer PO and the analyzer AN be (n−1 / 2) × λ. Here, λ is a reference wavelength of the phase plate PP, and n is an integer of 1 or more.

[Second embodiment]
FIG. 12 is a diagram illustrating a configuration of the polarization observation device 2 according to the present embodiment. FIG. 13 is a diagram showing the axial arrangement in the polarization observation device 2. The polarization observation device 2 shown in FIG. 12 is a device for visualizing the retardation of the retarder RE.

  As shown in FIG. 13, the polarization observation device 2 is in a state where the polarizer PO and the analyzer AN are slightly deviated from the state of orthogonal Nicols, specifically, the transmission axis of the polarizer PO and the transmission axis of the analyzer AN have a small angle β. This point is different from that of the polarization observation device 200 in that the angle is shifted only from 90 °. That is, the polarizer PO has a transmission axis directed in a direction different from a direction orthogonal to the transmission axis of the analyzer AN. In the present embodiment, the polarizer PO that can adjust the angle of the transmission axis is an example of the saturation adjustment unit of the polarization observation device 200, and adjusts the saturation by adjusting the angle of the transmission axis of the polarizer PO. .

  By disposing the polarizer PO in a state slightly deviated from the orthogonal Nicol state, in the orthogonal Nicol state, a part of the light blocked by the combination of the polarizer PO and the analyzer AN is transmitted, and the transmitted light is transmitted. Will be partially cut off. For this reason, by changing the direction of the transmission axis of the polarizer PO, it is possible to adjust the spectral intensity distribution of the transmitted light as in the case of the color filter CC of the polarization observation device 1, and the transmission intensity is higher than in the orthogonal Nicol state. The saturation of light interference color can be reduced. As a result, the retardation sensitivity is improved, and it is possible to detect the retarder RE having a small retardation.

  Further, the polarization observation device 2 is different from the polarization observation device 200 shown in FIG. 5 in that a compensator CO is provided on an optical axis AX connecting the light source S and the observer's eyes E. The compensator CO is an optical element that provides a variable phase difference between two polarization components having vibration directions orthogonal to each other, and is an example of a second phase delay unit of the polarization observation device 2.

  By adjusting the retardation generated between the polarizer PO and the analyzer AN by the compensator CO, the saturation of the interference color of the transmitted light can be minimized when the retardation of the retarder RE is around 0 nm. This makes it possible to detect the retarder RE with the highest retardation sensitivity of the polarization observation device 2.

  Further, as shown in FIG. 13, the polarization observation device 2 sets the phase plate PP such that the slow axis of the phase plate PP is not parallel to the slow axis of the retarder RE but forms a small angle α with the transmission axis of the polarizer PO. It is also different from the polarization observation device 200 in that the PP is arranged.

  By adjusting the direction of the slow axis of the phase plate PP, the retardation sensitivity is improved as described in Patent Document 2. This makes it possible to detect a retarder RE having a smaller retardation.

  FIG. 14 is a diagram showing the relationship between retardation and interference colors in the polarization observation device 2. FIG. 15 is a diagram illustrating a relationship between retardation and saturation of an interference color in the polarization observation device 2. FIG. 16 is a diagram illustrating the retardation sensitivity of the polarization observation device 2. Here, the light source S is a CIE standard light source with a color temperature of 5000 K, the phase plate PP has a retardation of 532 nm, is arranged at α = 4 °, and the compensator CO is a brace scaler compensator with a retardation of 30 nm.

  By rotating the polarizer PO from the orthogonal Nicol state by the angle β = 3.6 °, the saturation of transmitted light can be reduced as shown in FIGS. 14 and 15, and the retardation can be reduced as shown in FIG. Sensitivity can be improved. Specifically, the retardation sensitivity is increased about 7 times as compared with the case where β = 0 °. As a result, the retardation that can be detected by a human as a change in hue is reduced to about 2 nm. Note that the state of β = 0 corresponds to the technique described in Patent Document 2.

  Further, as shown in FIGS. 15 and 16, when the compensator CO is not used, the retardation of the retarder RE when the saturation becomes minimum is out of 0 nm. By using the compensator CO, the saturation can be minimized when the retardation of the retarder RE is 0 nm. Specifically, the slow axis of the compensator CO is inclined by 4.5 ° with respect to the transmission axis of the analyzer AN.

  Therefore, also with the polarization observation device 2 according to the present embodiment, similarly to the polarization observation device 1, it is possible to detect an observation target that causes small retardation based on a difference in hue. Further, in the polarization observation device 2, since the polarizer PO and the analyzer AN are out of the orthogonal Nicol state, the background portion where no retardation occurs is observed brighter than in the orthogonal Nicol state. This makes it easier to observe the retarder RE than when the background portion is in the dark Nicol state. Specifically, the spindle can be observed while checking the whole image of the ovum serving as the background.

  Note that, in the present embodiment, an example in which the polarizer PO and the analyzer AN are out of the orthogonal Nicol state is shown. Even when the polarizer PO and the analyzer AN are out of the parallel Nicol state, similar effects can be obtained. Can be. Further, although the example in which the polarizer PO is rotated from the orthogonal Nicol state is shown, the analyzer AN may be rotated from the orthogonal Nicol state. That is, the saturation adjusting means of the polarization observation device 2 may be any one of the polarizer PO and the analyzer AN, and may be directed in a direction different from a direction orthogonal to and parallel to the transmission axis of the other of the polarizer PO and the analyzer AN. What is necessary is just to have the transmission axis set.

  Further, in the present embodiment, an example in which the compensator CO is used has been described, but the compensator CO may be provided as needed. Further, in the present embodiment, an example has been described in which the slow axis of the phase plate PP is different from the slow axis of the retarder RE. However, the slow axis of the phase plate PP and the slow axis of the retarder RE may be changed as necessary. May be different.

  Further, the slow axis of the phase plate PP is directed in a direction shifted from a direction parallel to the transmission axis of one of the polarizer PO and the analyzer AN, n is an integer of 1 or more, and λ is a reference wavelength of the phase plate PP. In this case, the phase difference of the phase plate PP may be (n / 2) × λ.

[Third Embodiment]
FIG. 17 is a diagram illustrating a configuration of the polarization observation device 3 according to the present embodiment. The polarization observation device 3 shown in FIG. 17 is a device for visualizing the retardation of the retarder RE.

  As shown in FIG. 17, the polarization observation device 3 is different from the polarization observation device 200 in that a light source SA is provided instead of the light source S. The light source SA includes a plurality of LED light sources (LED light source Sr, LED light source Sg, and LED light source Sb) that emit illumination lights of different colors. The light source SA can emit illumination light having a predetermined spectral intensity distribution by adjusting the intensity of the illumination light emitted from each LED light source. The illumination light for reducing the color saturation is emitted.

  Note that the light source SA and the polarizer PO are examples of a polarization generation unit of the polarization observation device 3, and the light source SA is also a saturation adjustment unit of the polarization observation device 3. That is, the polarization observation device 3 is different from the polarization observation device 1 that realizes an arbitrary spectral intensity distribution by a combination of the light source S and the color filter CC in that an arbitrary spectral intensity distribution is realized by the light source SA alone.

  Also in the polarization observation device 3, since the saturation of the interference color is reduced by the saturation adjusting means, the retardation sensitivity can be improved. Therefore, similarly to the polarization observation device 1 and the polarization observation device 2, it is possible to detect an observation target that causes a small retardation based on a difference in hue.

  In the present embodiment, the example in which the light source SA includes a plurality of LED light sources has been described, but the light source SA may include a plurality of light sources that emit illumination lights of different colors. Therefore, the light source SA may include, for example, a plurality of laser light sources instead of the plurality of LED light sources.

[Fourth embodiment]
FIG. 18 is a diagram illustrating a configuration of the polarization observation device 4 according to the present embodiment. The polarization observation device 4 shown in FIG. 18 is a device for visualizing the retardation of the retarder RE.

  As shown in FIG. 18, the polarization observation device 4 differs from the polarization observation device 1 in that it includes a phase plate PPa and a phase plate PPb instead of the phase plate PP. The phase plate PPa and the phase plate PPb are a plurality of wavelength plates having different dispersions. By combining wavelength plates having different dispersions, the retardation sensitivity can be further improved.

  The phase plate PPa is, for example, a zero-order phase plate having a retardation of 133 nm, and a wavelength plate having a phase delay amount of / 4 wavelength. The phase plate PPb is, for example, an achromatic wavelength plate having a phase delay amount of / 4 wavelength. When the polarizer PO and the analyzer AN are arranged in a quadratic Nicols arrangement, the phase plates PPa and PPb are arranged such that their slow axes are orthogonal to each other. Accordingly, the retardation generated by the phase plate PPa and the phase plate PPb at the center wavelength cancel each other, and the background portion is extinguished. On the other hand, the amount of dispersion of the retardation of the combination of the phase plate PPa and the phase plate PPb is smaller than that of the phase plate having a zero-order phase delay amount of 1 wavelength and 1/2 wavelength, and thus has a higher retardation sensitivity than the polarization observation device 1. Can be realized. For example, as compared with the case where the polarizer PO and the analyzer AN are arranged in a parallel Nicols configuration and a zero-order phase plate with a retardation of 266 nm is used, retardation sensitivity about twice as high can be realized.

  Also in the polarization observation device 4, the saturation of the interference color is reduced by the saturation adjustment means, so that the retardation sensitivity can be improved as in the polarization observation device 1. In addition, by providing a plurality of phase plates having different dispersions, the total amount of dispersion can be reduced, and higher retardation sensitivity than the polarization observation device 1 can be realized. Therefore, according to the polarization observation device 4, it is possible to detect an observation target that causes a small retardation based on a difference in hue.

  In the present embodiment, an example is described in which one achromatic wavelength plate having substantially the same amount of phase delay in the visible region is included, but it is sufficient that at least one achromatic wavelength plate is included.

  Further, in the present embodiment, a case has been described where the polarizer PO and the analyzer AN are arranged in orthogonal Nicols, but the polarizer PO and the analyzer AN may be arranged in parallel Nicols. In that case, the same effect can be obtained by arranging the phase plate PPa and the phase plate PPb such that their slow axes are parallel to each other. That is, the plurality of wavelength plates having different dispersions may be arranged so as to extinguish light at the center wavelength (reference wavelength).

[Fifth Embodiment]
FIG. 19 is a diagram illustrating a configuration of the polarization observation device 5 according to the present embodiment. FIG. 20 is a diagram showing the axial arrangement in the polarization observation device 5.

  The polarization observation device 5 is an inverted microscope, and can switch and use a plurality of microscopy methods by rotating a turret TR to change an optical element arranged on an optical path. More specifically, the polarization observation device 5 can switch and use a bright field observation method, a polarization observation method, and a modulation contrast observation method.

  As shown in FIG. 19, the polarization observation device 5 includes a light source S and a condenser CD that irradiates the retarder RE with illumination light from the light source S. In addition, the polarization observation device 5 includes a turret TR and a polarizer PO3 between the light source S and the condenser CD. The polarizer PO3 is a polarizer used in the modulation contrast observation method, and is rotatably arranged to change the transmission axis direction. Furthermore, since the observation method other than the modulation contrast observation method is unnecessary, it is arranged so that it can be removed from the optical path.

  The polarization observation device 5 further includes a plurality of objective lenses mounted on the revolver R and an analyzer AN. The plurality of objective lenses include, for example, an objective lens OB1 and an objective lens OB2. The objective lens OB2 is an objective lens used in the modulation contrast observation method, and includes a modulator M at a pupil position of the objective lens OB2. The modulator M has three regions having different transmittances. The transmittances of the three regions are, for example, 100%, 25%, and 0%. The objective lens OB1 is an objective lens used for a method other than the modulation contrast observation method.

  The turret TR is a system condenser turret and houses four sets of optical elements that are selectively placed on the optical path. In this example, the turret TR accommodates one set of optical elements for modulation contrast observation, two sets of optical elements for polarization observation, and one set of optical elements for bright field observation. .

  The optical element S1 for the modulation contrast observation method is a modulator in which a part of the opening of the aperture plate AP1 is covered with a phase plate PP3. The optical element S1 is housed in the turret TR so as to be located at a position optically conjugate with the modulator M when arranged on the optical path.

  In the polarization observation device 5, the retarder RE can be observed by the modulation contrast observation method by arranging the objective lens OB2 and the optical element S1 for the modulation contrast observation method on the optical path. In the modulation contrast observation method, the retarder RE can be three-dimensionally observed by a modulation effect of a modulator arranged at an optically conjugate position.

  The polarization observation optical element S2 includes a color filter CC, a polarizer PO1, and a phase plate PP1. The color filter CC, the polarizer PO1, and the phase plate PP1 of the polarization observation device 5 correspond to the color filter CC, the polarizer PO, and the phase plate PP of the polarization observation device 1.

  The polarizer PO1 is an example of a polarization unit of the polarization observation device 5, and the polarizer PO1 and the analyzer AN are arranged such that the transmission axis of the polarizer PO1 is orthogonal to the transmission axis of the analyzer AN as shown in FIG. Is located.

  The phase plate PP1 is an example of a phase delay unit of the polarization observation device 5, and as shown in FIG. 20A, the slow axis of the phase plate PP1 and the transmission axis of the polarizer PO1 form an angle of 45 degrees. Is located. The phase plate PP1 is a one-wavelength plate that generates one-wave retardation with respect to the center wavelength of the light source S.

  The color filter CC is an example of a saturation adjusting unit of the polarization observation device 5. The color filter CC is, for example, a blue color filter.

  In the polarization observation device 5, the retarder RE can be observed by the polarization observation method by arranging the objective lens OB1 and the optical element S2 for the polarization observation method on the optical path. In particular, in this case, a retarder RE that causes a small retardation of about 4-5 nm can be detected as a difference in hue.

  The polarization observation optical element S3 includes a polarizer PO2 and a phase plate PP2. Note that the polarizer PO2 and the phase plate PP2 of the polarization observation device 5 correspond to the polarizer PO and the phase plate PP of the polarization observation device 2.

  The polarizer PO2 is an example of a polarizing unit of the polarization observation device 5. The polarizer PO2 and the analyzer AN are arranged such that the transmission axis of the polarizer PO2 is orthogonal to the transmission axis of the analyzer AN as shown in FIG. Oriented away from the More specifically, the polarizer PO2 is oriented in a direction rotated counterclockwise by 4 ° from an orthogonal direction.

  The phase plate PP2 is an example of a phase delay unit of the polarization observation device 5, and is arranged such that the slow axis of the phase plate PP2 and the transmission axis of the polarizer PO2 are parallel as shown in FIG. Have been. The phase plate PP2 is a one-wavelength plate that generates one wavelength of retardation with respect to the center wavelength of the light source S.

  In the polarization observation device 5, the retarder RE can be observed by the polarization observation method by arranging the objective lens OB1 and the optical element S3 for the polarization observation method on the optical path. In particular, in this case, a retarder RE that causes a small retardation of about 2 nm can be detected as a difference in hue.

  The optical element S4 for the bright-field observation method is the aperture plate AP2. In the polarization observation device 5, the retarder RE can be observed by the bright field observation method by arranging the objective lens OB1 and the optical element S4 for bright field observation on the optical path.

  Also in the polarization observation device 5, in the polarization observation method, since the saturation of the interference color is reduced by the saturation adjustment means, the retardation sensitivity can be improved as in the polarization observation device 1. Therefore, according to the polarization observation device 5, it is possible to detect an observation target that causes a small retardation based on a difference in hue.

  Furthermore, in the polarization observation device 5, in the polarization observation method, by switching between two sets of optical elements having different retardation sensitivities, the maturity of the spindle of the egg can be determined in more detail. More specifically, for example, by using the optical element S2, it is possible to detect a spindle of a mature egg that causes a retardation of about 5 nm. However, the spindle before matured sufficiently cannot be detected because the retardation is too small. On the other hand, by using the optical element S3, it is possible to detect a spindle of a mature egg that causes a retardation of about 5 nm, and a spindle that is not yet mature enough to cause a smaller retardation. However, it is not easy to distinguish between the spindle of a mature egg and the spindle of an egg before maturation. In the polarization observation device 5, by switching and using these two sets of optical elements, it is possible to distinguish and detect both the spindle of the mature egg and the spindle of the egg before maturation.

[Sixth Embodiment]
FIG. 21 is a diagram illustrating a configuration of the polarization observation device 6 according to the present embodiment. The polarization observation device 6 is an inverted microscope. By changing the optical element arranged on the optical path by rotating the turret TR, a plurality of microscopy methods can be switched and used. Same as 5.

  The polarization observation device 6 is different from the polarization observation device in that a light source SA is provided instead of the light source S, a compensator CO is provided, and an optical element S2a is accommodated in the turret TR instead of the optical element S2. It is different from the device 5. The other points are the same as those of the polarization observation device 5.

  The light source SA is the same as the light source SA of the polarization observation device 3 described in the second embodiment. That is, the light source SA is an example of the saturation adjusting unit of the polarization observation device 6.

  The compensator CO is an optical element that gives a variable phase difference between two polarization components having vibration directions orthogonal to each other, and is an example of a second phase delay unit of the polarization observation device 6. The compensator CO is, for example, a Senarumon compensator, a Berek compensator, a brace scaler compensator, or the like. By adjusting the retardation of the compensator, the saturation is minimized when the retardation of the retarder RE is about 0 nm.

  The optical element S2a is the same as the optical element S2 except that the optical element S2a does not include the color filter CC. The optical element S2a includes a polarizer PO1 and a phase plate PP1. That is, the polarizer PO1 is an example of a polarization unit of the polarization observation device 6, and the polarizer PO1 and the analyzer AN are arranged such that the transmission axis of the polarizer PO1 is orthogonal to the transmission axis of the analyzer AN. The phase plate PP1 is an example of a phase delay unit of the polarization observation device 5, and is arranged such that the slow axis of the phase plate PP1 and the transmission axis of the polarizer PO1 form an angle of 45 degrees.

  The polarization observation device 6 emits white light from the light source SA in the polarization observation method in which the optical element S3 is arranged on the optical path. On the other hand, in the polarization observation method in which the optical element S2a is disposed on the optical path, by adjusting the intensity of the illumination light emitted from each LED light source of the light source SA, the interference color of the transmitted light can be more improved than when white light is emitted. The illumination light for reducing the saturation of the illumination light is emitted.

  Also in the polarization observation device 6, in the polarization observation method, since the saturation of the interference color is reduced by the saturation adjustment means, the retardation sensitivity can be improved as in the polarization observation device 5. Therefore, according to the polarization observation device 6, it is possible to detect an observation object that causes a small retardation based on a difference in hue. Further, in the polarization observation method, the degree of maturity of the spindle of the ovum can be determined in more detail by switching between two sets of optical elements having different retardation sensitivities, similarly to the polarization observation device 5.

[Seventh Embodiment]
FIG. 22 is a diagram illustrating a configuration of the polarization observation device 7 according to the present embodiment. FIG. 23 is a diagram showing the axial arrangement in the polarization observation device 7. The polarization observation device 7 includes a color filter CC, a polarizer PO, a phase plate PP, a liquid crystal variable retarder RT, and an analyzer AN on an optical axis AX connecting the light source S and the observer's eyes E. The retarder RE is arranged on an optical path between the polarizer PO and the phase plate PP.

  The color filter CC is an example of a saturation adjusting unit of the polarization observation device 7, and attenuates a part of the wavelength range of the incident light in accordance with the spectral intensity distribution of the incident light, so that the color filter CC is less than the case without the color filter CC. Reduce the saturation of transmitted light interference color.

  The polarizer PO and the analyzer AN are examples of a polarization unit and a polarization unit of the polarization observation device 7, respectively, and are arranged so that their transmission axes are parallel to each other, as shown in FIG.

  The phase plate PP is an example of a phase delay unit of the polarization observation device 7, and is a half-wave plate that generates a half-wave retardation with respect to the center wavelength of the light source S. The phase plate PP is arranged such that the slow axis of the phase plate PP forms an angle of 45 ° with the transmission axes of the polarizer PO and the analyzer AN.

  The liquid crystal variable retarder RT is an optical element that selectively generates a certain amount of retardation. As shown in FIG. 23, the liquid crystal variable retarder RT and the phase plate PP are arranged such that their delay axes are orthogonal to each other, that is, they are arranged in a phase-reduction arrangement, and cancel each other's retardation.

  In the polarization observation device 7, the polarity of the retardation generated between the polarizer PO and the analyzer AN can be reversed by ON / OFF of the liquid crystal variable retarder RT. As a result, the chromaticity of the transmitted light is also inverted according to the sign of the retardation of the retarder RE.

  In the polarization observation device 7, as in the polarization observation device 1, the saturation of the interference color is reduced by the color filter CC, so that the retardation sensitivity can be improved. Therefore, according to the polarization observation device 7, it is possible to detect an observation target that causes a small retardation based on a difference in hue. In the polarization observation device 7, the chromaticity of the interference color can be inverted by turning on / off the liquid crystal variable retarder RT. Therefore, whether or not the coloring of the retarder RE is caused by the birefringence can be confirmed by the change in chromaticity. For example, in the spindle observation, when the chromaticity changes due to ON / OFF of the liquid crystal variable retarder RT, it can be determined that the retarder RE is an object having birefringence. For this reason, it is possible to avoid a situation where the wrong target is mistaken for the spindle.

  The embodiments described above show specific examples for facilitating the understanding of the invention, and the embodiments of the invention are not limited to these. Various modifications and changes can be made to the polarization observation device without departing from the scope of the claims.

1, 2, 3, 4, 5, 6, 7, 100, 200 Polarization observation device AP1, AP2 Aperture plate AN Analyzer AX Optical axis CC Color filter CD Capacitor CO Compensator E Eye M Modulator OB1, OB2 Objective lens PP, PP1, PP2, PP3, PPa, PPb Phase plate PO, PO1, PO2, PO3 Polarizer R Revolver RE Retarder RT Liquid crystal variable retarder S, SA light sources Sr, Sg, Sb LED light sources S1, S2, S3, S4 Optical element TR Turret

Claims (20)

Polarization generating means for generating completely polarized light to irradiate the observation object,
Analysis means for transmitting a polarized light component having a specific vibration direction,
A phase delay unit that is disposed on an optical path between the polarization generation unit and the light detection unit and provides a predetermined phase difference between two polarization components having vibration directions orthogonal to each other; Converting the interference color of the transmitted light into a sharp color by the predetermined phase difference, the phase delay unit,
And a saturation adjusting unit for bringing the interference color of the transmitted light closer to an achromatic color. The polarization observation device according to claim 1,
The saturation adjustment means,
An optical filter having a predetermined spectral transmittance characteristic,
By attenuating a part of the wavelength range of the incident light according to the spectral intensity distribution of the incident light, the saturation of the interference color of the transmitted light can be reduced as compared with a case where the polarization observation device does not include the saturation adjustment unit. A polarization observation device characterized by being reduced in size. The polarization observation device according to claim 1,
The polarization generation unit includes a polarization unit that transmits a polarization component having a specific vibration direction,
The saturation adjustment means,
One of the polarizing means and the analyzing means,
A polarization observation device having a transmission axis oriented in a direction different from a direction perpendicular to and parallel to a transmission axis of the other of the polarizing unit and the analyzing unit. The polarization observation device according to claim 1,
The saturation adjustment unit is a light source included in the polarization generation unit,
The polarization observation apparatus, wherein the light source emits illumination light that makes the saturation of the interference color of the transmitted light smaller than that of a case where white light is emitted. In the polarization observation device according to any one of claims 1 to 4,
The saturation adjusting unit is configured to make the interference color of the transmitted light closer to an achromatic color, thereby obtaining the saturation of the interference color of the transmitted light, C * being the saturation in the L * a * b * color space. A polarization observation device characterized by being adjusted to 20 or less. In the polarization observation device according to any one of claims 1 to 5,
The saturation adjustment means, so that the change of the hue angle of the interference color of the transmitted light with respect to the change of 5 nm of the phase delay amount occurring in the optical path between the polarization generation means and the light detection means is 90 ° or more, A polarized light observation apparatus, wherein an interference color of the transmitted light is made closer to an achromatic color. The polarization observation device according to any one of claims 1 to 6, further comprising:
A polarization observation device comprising: a second phase delay unit that provides a variable phase difference between two polarization components having vibration directions orthogonal to each other. The polarization observation device according to any one of claims 1 to 7,
The polarization observation device, wherein the phase delay unit includes a plurality of wave plates having different dispersions. The polarization observation device according to claim 8,
The plurality of wave plates include at least one achromatic wave plate. In the polarization observation device according to claim 8 or 9,
The polarization observation device, wherein the plurality of wave plates are arranged so as to compensate for each other's retardation at a reference wavelength. In the polarization observation device according to any one of claims 1 to 10,
The polarization observation device, wherein the completely polarized light includes light in a visible region. The polarization observation device according to claim 2,
The polarization generation unit includes a polarization unit that transmits a polarization component having a specific vibration direction,
The polarizing means and the analyzing means are arranged such that the transmission axis of the polarizing means and the transmitting axis of the analyzing means are parallel,
The phase delay unit is disposed such that the transmission axis of the polarization unit and the slow axis of the phase delay unit form an angle of 45 degrees,
When n is an integer of 1 or more and λ is a reference wavelength of the phase delay means, the predetermined phase difference is (n−1 / 2) × λ. The polarization observation device according to claim 2,
The polarization generation unit includes a polarization unit that transmits a polarization component having a specific vibration direction,
The polarizing unit and the analyzing unit are arranged such that a transmission axis of the polarizing unit and a transmission axis of the analyzing unit are orthogonal to each other,
The phase delay unit is disposed so that the slow axis of the phase delay unit and the transmission axis of the polarization unit form an angle of 45 degrees,
When n is an integer of 1 or more and λ is a reference wavelength of the phase delay means, the predetermined phase difference is n × λ. The polarization observation device according to claim 3,
The transmission axis of one of the polarizing unit and the analyzing unit is directed to a direction shifted from a direction orthogonal to the transmission axis of the polarizing unit and the other of the analyzing unit,
The slow axis of the phase delay means is directed in a direction shifted from a direction parallel to the transmission axis of the polarization means and one of the light analysis means,
When n is an integer of 1 or more and λ is a reference wavelength of the phase delay means, the predetermined phase difference is (n / 2) × λ. In the polarization observation device according to any one of claims 12 to 14,
The polarization observation device, wherein the reference wavelength is a wavelength in a visible region. The polarization observation device according to any one of claims 2 to 4, further comprising:
A turret that switches the optical element to be arranged on the optical path according to the observation method,
The polarization observation device, wherein the phase delay unit is disposed in the turret. The polarization observation device according to claim 2, further comprising:
A turret that switches the optical element to be arranged on the optical path according to the observation method,
The polarization generation unit includes a polarization unit that transmits a polarization component having a specific vibration direction,
The combination of the phase delay unit and the polarization unit is disposed in the turret. The polarization observation device according to claim 3, further comprising:
A turret that switches the optical element to be arranged on the optical path according to the observation method,
A combination of the phase delay unit and the polarization unit is disposed in the turret. In the polarization observation device according to claim 17 or 18,
A combination of the phase delay unit, the polarization unit, and the saturation adjustment unit is disposed in the turret. The polarization observation device according to claim 19,
Disposed in the turret, comprising a plurality of combinations of the phase delay unit, the polarization unit and the saturation adjustment unit,
The polarization observation apparatus, wherein the turret switches the plurality of combinations.