Optical device

Abstract

To provide an optical device in which the length of the part of an optical path which passes through a measurement target can be easily changed while the influence on the measurement target is being suppressed.SOLUTION: An optical device 1 according to the present disclosure includes: an optical element block 10 having an optical element for forming an optical path P of light used for an optical measurement and arranged around a measurement target S so that the optical path P intersects with the measurement target S; and a rotary mechanism 20 for changing a relative angle between the measurement target S and the optical element block 10 so that the total length of the part of the optical path P which overlaps with the measurement target S will be changed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to optical devices. [Background technology]

[0002] Conventionally, techniques for optically measuring a measurement target including a liquid to be measured have been known. Such optical measurements are performed while changing the optical path length of the light used in the optical measurement in the measurement target. For example, Patent Document 1 discloses a variable optical path length cell that allows the optical path length to be changed without modifying the device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-194775 Summary of the Invention [Problem to be solved by the invention]

[0004] In the variable optical path length cell described in Patent Document 1, it is necessary to insert an optical path length changing block into the liquid to be measured inside the cell, which obstructs the flow of the liquid to be measured and changes the pressure loss. In other words, when the length of the portion of the optical path in the variable optical path length cell that passes through the object to be measured is changed, a physical effect is exerted on the liquid to be measured, which is the object to be measured.

[0005] An object of the present disclosure is to provide an optical device that can easily change the length of the portion of the optical path that passes through the object to be measured while suppressing the influence on the object to be measured. [Means for solving the problem]

[0006] In some embodiments, the spectroscopic measurement device includes an optical element block having an optical element that forms an optical path of light used in optical measurement, and that is arranged around the measurement object so that the optical path intersects with the measurement object, and a rotation mechanism that changes the relative angle between the measurement object and the optical element block so that the total length of the portion of the optical path that overlaps with the measurement object changes.

[0007] This makes it possible to easily change the length of the portion of the optical path that passes through the measurement object while suppressing the influence on the measurement object. The optical device can easily change the overall length of the portion of the optical path that overlaps with the measurement object by changing the relative angle between the measurement object and the optical element block arranged outside the measurement object. The optical device arranges the optical elements that form the optical path around the measurement object, and does not arrange any elements inside the liquid to be measured, for example, which is the measurement object, so it is possible to suppress the influence on the measurement object. The optical device can suppress physical influences such as changes in pressure loss and flow rate in the measurement object.

[0008] In one embodiment of the optical device, the optical element block may have a frame to which the optical elements are attached and which surrounds the measurement target, with the measurement target being positioned at the center of the frame. This allows the optical device to further reduce the impact on the measurement target when changing the optical path length of the portion of the optical path that overlaps with the measurement target. The optical device can easily and quickly change the optical path length to perform optical measurements without the need to, for example, change the size of a cell containing the liquid to be measured or make other design changes. The optical device can flexibly change the optical path length.

[0009] In one embodiment of the optical device, the rotation mechanism may be attached to the optical element block and may rotate the optical element block to change the angle of the optical element block relative to the measurement object. This allows the optical device to change the optical path length by manipulating only the optical element block without performing any operation on the measurement object. This allows the optical device to further reduce the impact on the measurement object when changing the optical path length. In addition, the optical device can change the optical path length simply by rotating the optical element block. Therefore, the optical device can easily and quickly change the optical path length to perform optical measurements.

[0010] In one embodiment of the optical device, the optical element block may include a first block and a second block that rotates by the rotation mechanism, and the first block may include a first lens that directs parallel light toward the object to be measured, and a first mirror that reflects the parallel light that has passed through the object to be measured toward the second block.

[0011] This allows the optical device to significantly change the optical path length of the portion of the optical path that overlaps with the measurement target. For example, by rotating the second block using a rotation mechanism, the optical device can change the optical path length by an integer multiple of the width of the cell along the optical path due to normal incidence and normal emission of light to the cell. More specifically, the optical device can change the optical path length between one and two times the width of the cell along the optical path.

[0012] In one embodiment, the second block may include a second mirror that further reflects the collimated light, and a second lens that condenses the reflected collimated light.

[0013] This allows the optical device to limit the optical elements through which light passes and causes light loss to a pair of lenses. Therefore, the optical device can maintain a substantially constant optical loss even when the optical path length of the portion of the optical path that overlaps with the measurement object is changed. Therefore, the optical device can suppress a decrease in the signal strength and S / N ratio of light detected after passing through the optical device. This allows the optical device to easily obtain a desired signal strength for light used in optical measurement, and easily maintain measurement accuracy in optical measurement.

[0014] In one embodiment, the second block may include a third mirror that further reflects the collimated light and makes it incident on the measurement object, and a third lens that focuses the collimated light that has passed through the measurement object. This allows the optical device to limit the optical elements through which light passes and causes light loss to just the pair of lenses. Therefore, the optical device similarly achieves the above-described effect regarding measurement accuracy in optical measurement.

[0015] In one embodiment of the optical device, the optical element block further includes a third block, the second block includes a fourth mirror that further reflects the parallel light to make it further incident on the measurement object, and a fifth mirror that further reflects the parallel light that has passed through the measurement object toward the third block, and the third block includes a sixth mirror that further reflects the parallel light to make it further incident on the measurement object, and a fourth lens that focuses the parallel light that has passed through the measurement object.

[0016] This allows the optical device to significantly change the optical path length of the portion of the optical path that overlaps with the measurement target. For example, by rotating the second block using a rotation mechanism, the optical device can change the optical path length by an integer multiple of the width of the cell along the optical path caused by normal incidence and normal emission of light to and from the cell. More specifically, the optical device can change the optical path length between 1, 2, and 3 times the width of the cell along the optical path.

[0017] In one embodiment of the optical device, the frame may include a first frame, a second frame, and a third frame, the first block may have the first frame in a rectangular shape, the second block may have the second frame in a hexagonal shape, and the third block may have the third frame in a rectangular shape.

[0018] This allows the optical device to improve the rotational symmetry of each frame with respect to the cell, and therefore the optical device can easily realize a plurality of different optical systems by rotating the frame using the rotation mechanism.

[0019] In one embodiment, the measurement object may include a liquid to be measured contained in a cell, which allows the optical device to easily perform optical measurement using an optical path on the liquid to be measured flowing in one direction through the cell, for example.

[0020] In one embodiment, the cross section of the cell when viewed from the extension direction of the cell may have a square shape, thereby improving the rotational symmetry of the optical device including the cell and each frame. [Effects of the Invention]

[0021] According to the present disclosure, it is possible to provide an optical device that can easily change the length of the portion of the optical path that passes through the object to be measured while suppressing the influence on the object to be measured. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a schematic diagram illustrating a schematic configuration of an optical device according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a schematic diagram showing an example of the configuration of a first block in FIG. 1. [Figure 3] FIG. 2 is a schematic diagram showing an example of the configuration of a second block in FIG. 1. [Figure 4]1. FIG. 4 is a schematic diagram corresponding to FIG. 1, illustrating another example of an optical system in the optical device of FIG. [Figure 5] 1. FIG. 4 is a schematic diagram corresponding to FIG. 1 and showing a schematic configuration of an optical device according to a second embodiment of the present disclosure. [Figure 6] 1. FIG. 4 is a schematic diagram corresponding to FIG. 1 and showing a schematic configuration of an optical device according to a third embodiment of the present disclosure. [Figure 7] 10 is a schematic diagram corresponding to FIG. 2 and illustrating an example of a schematic configuration of an optical device according to a fourth embodiment of the present disclosure. [Figure 8] 10 is a schematic diagram corresponding to FIG. 2 and illustrating another example of the schematic configuration of the optical device according to the fourth embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0023] The background and problems of the prior art will now be described in more detail.

[0024] The variable optical path length cell described in Patent Document 1 has a cell body that has a light entrance window and a light exit window made of transparent flat plates arranged parallel to each other and through which the liquid to be measured is contained or flows. The variable optical path length cell has a plurality of pairs of flat surfaces and an optical path length changing block made of a transparent material that is detachably inserted into the cell body.

[0025] The optical path length can be changed in multiple steps by selecting a pair of planes with any thickness from the multiple pairs of planes that the optical path length changing block has and inserting the optical path length changing block into the optical path inside the cell. The absorbance measurement method using the above-mentioned variable optical path length cell enables absorbance measurement at multiple optical path lengths by fixing the cell body with respect to the optical path of the measurement light and moving the optical path length changing block in a direction crossing the optical path of the measurement light.

[0026] However, the variable optical path length cell described in Patent Document 1 has the following problems.

[0027] In the variable optical path length cell described in Patent Document 1, it is necessary to insert an optical path length changing block into the cell body while immersed in the liquid to be measured, which impedes the flow of the liquid to be measured and changes the pressure loss. In other words, when the length of the portion of the optical path in the variable optical path length cell that passes through the object to be measured is changed, a physical effect is exerted on the liquid to be measured.

[0028] In the variable optical path length cell described in Patent Document 1, if the optical path length changing block immersed in the liquid to be measured becomes contaminated by the liquid, the optical path length changing block needs to be cleaned. Therefore, a great deal of effort is required for maintenance work on devices related to optical measurements using the variable optical path length cell.

[0029] In the variable optical path length cell described in Patent Document 1, an optical path length changing block serving as a transmissive optical member is arranged across the optical path. Therefore, optical loss occurs due to interfacial reflection caused by the difference in refractive index between the optical path length changing block serving as a transmissive optical member and the liquid to be measured, and absorption caused by the optical absorption characteristics of the optical path length changing block itself, resulting in a decrease in measurement accuracy in optical measurements.

[0030] In order to solve the above problems, the present disclosure aims to provide an optical device that can easily change the length of the portion of the optical path that passes through the object to be measured while suppressing the influence on the object to be measured. Another aim of the present disclosure is to provide an optical device that can flexibly change the optical path length in the object to be measured and can easily obtain a desired signal strength for the light used in optical measurement.

[0031] Hereinafter, one embodiment of the present disclosure will be mainly described with reference to the accompanying drawings.

[0032] (First embodiment) Fig. 1 is a schematic diagram showing a general configuration of an optical device 1 according to a first embodiment of the present disclosure. In Fig. 1, for ease of understanding, only optical elements that directly contribute to forming an optical path P of light used in optical measurement are shown, out of multiple optical elements described later with reference to Figs. 2 and 3. Fig. 1 shows the optical device 1 and the cell C as viewed from the side along the extension direction D of the cell C, through which the measurement object S flows in one direction.

[0033] The optical device 1 is used to form an optical path P of light used in optical measurement of a measurement target S. In this disclosure, the "measurement target S" includes, for example, a measurement target liquid contained in a cell C and flowing in one direction. "Optical measurement" includes, for example, measuring the light absorption characteristics of the measurement target S, which are indicated by an absorption spectrum. "Light" includes, for example, measurement target light from an arbitrary light source located outside the optical device 1, and measurement target light as transmitted light that enters the optical device 1 and passes through the measurement target S. The "optical path P" includes, for example, the entire path of light formed by the optical device 1.

[0034] The optical device 1 includes an optical element block 10 and a rotation mechanism 20 .

[0035] The optical element block 10 has optical elements that form an optical path P of light used in optical measurement, and is arranged around the measurement object S so that the optical path P intersects with the measurement object S. The measurement object S is housed, for example, in a cell C and exists in the internal space of the cell C. The optical element block 10 is arranged around the cell C that houses the measurement object S, and is located outside the cell C. In the first embodiment, the optical element block 10 has a first block 11 and a second block 12 that is rotated by a rotation mechanism 20.

[0036] FIG. 2 is a schematic diagram showing an example of the configuration of the first block 11 in FIG. 1. FIG. 3 is a schematic diagram showing an example of the configuration of the second block 12 in FIG. 1. Unlike FIG. 1, FIGS. 2 and 3 show the optical device 1 and the cell C as viewed from the front in the extension direction D of the cell C. While the test liquid as the measurement target S flows from left to right inside the cell C in FIG. 1, in FIGS. 2 and 3, the test liquid flows inside the cell C, for example, from the front to the back of the paper. As shown in FIGS. 2 and 3, the cross section of the cell C when viewed from the extension direction D of the cell C has a square shape. With primary reference to FIGS. 2 and 3, examples of the configuration of the first block 11 and the second block 12 in FIG. 1 will be described, respectively.

[0037] The optical element block 10 has a frame F to which optical elements are attached and which surrounds the periphery of the measurement target S. The frame F is made of, for example, any metal material or resin material used in optical systems. The optical element block 10 positions the measurement target S at the center of the frame F. In the first embodiment, the frame F has a first frame F1 and a second frame F2.

[0038] As shown in Fig. 2, the first block 11 has a rectangular first frame F1. The first block 11 is hollow and has a cell C located at its center. The four sides of the first frame F1 of the first block 11 are arranged around the cell C located at the center of the first block 11 so as to surround the cell C from four directions. The first frame F1 has a first side F11 located on the upper side in Fig. 2, a second side F12 located on the right side, a third side F13 located on the lower side, and a fourth side F14 located on the left side.

[0039] The first block 11 is a hollow square block that holds, on each side of the first frame F1, a plurality of optical elements, including, for example, a light-collecting optical element and a reflecting optical element, etc. The first block 11 holds the plurality of optical elements by, for example, properly attaching the plurality of optical elements to the plurality of holders in a state where the plurality of holders are integrally attached to the first frame F1.

[0040] More specifically, the first block 11 has a mirror 11a attached to the first side F11. The first block 11 has a mirror 11b attached to the second side F12. The first block 11 has a lens 11c attached to the third side F13. The first block 11 has a mirror 11d attached to the fourth side F14. The mirrors 11a, 11b, and 11d are attached to the first frame F1 so as to be inclined at 45° to the right or left with respect to the extension direction D of the cells C in a side view as shown in FIG.

[0041] As shown in FIG. 3, the second block 12 has a hexagonal second frame F2. The second block 12 is hollow and has a cell C located at its center. The six sides of the second frame F2 of the second block 12 are arranged around the cell C located at the center of the second block 12, surrounding the cell C from six directions. The second frame F2 has a first side F21 located at the top, a second side F22 located at the top right, a third side F23 located at the bottom right, a fourth side F24 located at the bottom, a fifth side F25 located at the bottom left, and a sixth side F26 located at the top left in FIG. 3.

[0042] The second block 12 is a hollow regular hexagonal block that holds, on each side of the second frame F2, a plurality of optical elements, including, for example, a light-collecting optical element, a reflecting optical element, and a combination thereof. The second block 12 holds the plurality of optical elements by, for example, properly attaching the plurality of optical elements to the plurality of holders in a state where the plurality of holders are integrally attached to the second frame F2.

[0043] More specifically, the second block 12 has a combination of a mirror 12a and a lens 12b attached to the first side F21. The second block 12 has a mirror 12c attached to the second side F22. The second block 12 has a lens 12d attached to the third side F23. The second block 12 has a mirror 12e attached to the fifth side F25. The second block 12 has a mirror 12f attached to the sixth side F26. The mirrors 12a, 12c, 12e, and 12f are attached to the second frame F2 so as to be inclined 45° to the right or left with respect to the extension direction D of the cell C in a side view as shown in FIG. 1.

[0044] The rotation mechanism 20 changes the relative angle between the measurement target S and the optical element block 10 so as to change the overall length of the portion of the optical path P that overlaps with the measurement target S. For example, the rotation mechanism 20 is attached to the optical element block 10 and rotates the optical element block 10 to change the angle of the optical element block 10 with respect to the measurement target S. As shown in FIG. 1 , in the first embodiment, the rotation mechanism 20 is attached to, for example, the second block 12 of the optical element block 10 and rotates the second block 12 to change the angle of the second block 12 with respect to the measurement target S.

[0045] 1, the optical device 1 forms an optical path P while maintaining a predetermined angle for each of the first block 11 and the second block 12. For example, the second block 12 maintains the angle shown in FIG. 1 after being rotated by the rotation mechanism 20.

[0046] In the side view of FIG. 1 , a first side F11 of the first block 11 is located above the cell C. A second side F12 of the first block 11 is located in front of the cell C. A third side F13 of the first block 11 is located below the cell C. A fourth side F14 of the first block 11 is located behind the cell C.

[0047] Mirror 11a attached to the first side F11 of first block 11 is disposed above cell C at an angle facing second block 12. Lens 11c attached to the third side F13 of first block 11 is disposed below cell C so as to face cell C. In FIG. 1, mirrors 11b and 11d are located on the front and back sides of cell C, respectively, but these optical elements that do not directly contribute to the formation of optical path P are not shown.

[0048] In the side view of FIG. 1 , a first side F21 of the second block 12 is located above the cell C. A second side F22 of the second block 12 is located above the front of the cell C. A third side F23 of the second block 12 is located below the front of the cell C. A fourth side F24 of the second block 12 is located below the cell C. A fifth side F25 of the second block 12 is located below the back of the cell C. A sixth side F26 of the second block 12 is located above the back of the cell C.

[0049] The combination of mirror 12a and lens 12b attached to first side F21 of second block 12 is disposed above cell C. Mirror 12a is disposed at an angle so as to face first block 11 and lens 12b. In FIG. 1, mirror 12c, lens 12d, mirror 12e, and mirror 12f are located on the upper front side, lower front side, lower back side, and upper back side of cell C, respectively, but these optical elements that do not directly contribute to the formation of optical path P are not shown.

[0050] The optical device 1 allows light to enter from the third side F13 of the first block 11, where a lens 11c is attached as a collimating means. The lens 11c converts the light entering the optical device 1 into collimated light and causes the collimated light to enter the measurement target S. The lens 11c corresponds to the "first lens" described in the claims. The optical device 1 transmits the collimated light through a cell C containing a liquid to be measured as the measurement target S.

[0051] The optical device 1 causes the parallel light transmitted through the cell C to be incident on a mirror 11a attached to the first frame F1 in the first block 11 so as to be tilted 45° to the left with respect to the extension direction D of the cell C. The mirror 11a reflects the parallel light transmitted through the measurement target S toward the second block 12. The mirror 11a corresponds to the "first mirror" recited in the claims. The mirror 11a reflects the parallel light back by 90° and causes it to be incident on the second block 12.

[0052] In the optical device 1, the collimated light reflected by the mirror 11a at 90° is incident on the mirror 12a, which is attached to the second frame F2 in the second block 12 so as to be tilted 45° to the left with respect to the extension direction D of the cells C. The mirror 12a further reflects the collimated light toward the lens 12b. The mirror 12a corresponds to the "second mirror" recited in the claims. The mirror 12a reflects the collimated light by 90° and makes it incident on the lens 12b.

[0053] The lens 12b focuses the parallel light reflected by the mirror 12a. The lens 12b corresponds to the "second lens" in the claims. The lens 12b focuses the parallel light and guides it to a detector such as a photodetector located outside the optical device 1 or to an optical transmission path such as an optical fiber.

[0054] The optical device 1 adjusts the angle of the second block 12 using the rotation mechanism 20 so that the pair of sides parallel to the cell C is the first side F21 and the fourth side F24. In this way, the optical device 1 forms an optical path P through which light is transmitted once through the cell C containing the liquid to be measured as the measurement target S. The optical path P is perpendicular to the cell C. In other words, in one transmission, the parallel light enters one surface of the cell C perpendicularly and exits from the other surface perpendicularly.

[0055] Fig. 4 is a schematic diagram corresponding to Fig. 1, showing another example of the optical system in the optical device 1 of Fig. 1. In Fig. 4, the angle of the first block 11 relative to the cell C is the same as the angle shown in Fig. 1, but the angle of the second block 12 relative to the cell C is different from the angle shown in Fig. 1.

[0056] 4, the optical device 1 forms the optical path P while maintaining a predetermined angle for each of the first block 11 and the second block 12. For example, the second block 12 maintains the angle shown in FIG. 4 after being rotated by the rotation mechanism 20.

[0057] In the side view of FIG. 4, the sixth side F26 of the second block 12 is located above the cell C. The first side F21 of the second block 12 is located above the front of the cell C. The second side F22 of the second block 12 is located below the front of the cell C. The third side F23 of the second block 12 is located below the cell C. The fourth side F24 of the second block 12 is located below the back of the cell C. The fifth side F25 of the second block 12 is located above the back of the cell C.

[0058] Mirror 12f attached to the sixth side F26 of second block 12 is disposed above cell C. Mirror 12f is disposed at an angle so as to face the first block 11 and cell C. Lens 12d attached to the third side F23 of second block 12 is disposed below cell C so as to face cell C. In FIG. 4, the combination of mirror 12a and lens 12b, mirror 12c, and mirror 12e are located on the upper front side, lower front side, and upper back side of cell C, respectively, but these optical elements that do not directly contribute to the formation of optical path P are not shown.

[0059] The optical device 1 allows light to be incident on the third side F13 of the first block 11, where a lens 11c serving as a collimating means is attached. The lens 11c converts the light incident on the optical device 1 into collimated light and causes the collimated light to be incident on the measurement target S. The optical device 1 transmits the collimated light through a cell C containing a liquid to be measured as the measurement target S.

[0060] The optical device 1 causes the parallel light that has passed through the cell C to be incident on a mirror 11a that is attached to the first frame F1 in the first block 11 so as to be inclined at 45° to the left with respect to the extension direction D of the cell C. The mirror 11a reflects the parallel light that has passed through the measurement target S toward the second block 12. The mirror 11a turns the parallel light back by 90° and causes it to be incident on the second block 12.

[0061] The optical device 1 causes the collimated light reflected by the mirror 11a at 90° to be incident on a mirror 12f attached to the second frame F2 in the second block 12 so as to be tilted at 45° to the right with respect to the extension direction D of the cell C. The mirror 12f further reflects the collimated light toward the cell C, causing the collimated light to be incident on the measurement target S. The mirror 12f corresponds to a "third mirror" recited in the claims. The mirror 12f reflects the collimated light by 90° and causes it to be incident on the measurement target S.

[0062] The lens 12d focuses the parallel light that has passed through the measurement target S. The lens 12d corresponds to the "third lens" in the claims. The lens 12d focuses the parallel light and guides it to a detector such as a photodetector located outside the optical device 1 or to an optical transmission path such as an optical fiber.

[0063] The optical device 1 adjusts the angle of the second block 12 using the rotation mechanism 20 so that the set of sides parallel to the cell C is the sixth side F26 and the third side F23. As a result, the optical device 1 forms an optical path P through which light is transmitted twice through the cell C containing the liquid to be measured as the measurement target S. The optical path P is orthogonal to the cell C. That is, in both of the two transmissions, the parallel light enters perpendicularly to one surface of the cell C and exits perpendicularly from the other surface.

[0064] According to the optical device 1 of the first embodiment described above, it is possible to easily change the length of the portion of the optical path P that passes through the measurement object S while suppressing the influence on the measurement object S. The optical device 1 can easily change the overall length of the portion of the optical path P that overlaps with the measurement object S by changing the relative angle between the measurement object S and the optical element block 10 arranged outside the measurement object S. The optical device 1 arranges the optical elements that form the optical path P around the measurement object S, and does not arrange any elements inside the liquid to be measured, which is the measurement object S, so it is possible to suppress the influence on the measurement object S. The optical device 1 can suppress physical influences on the measurement object S, such as changes in pressure loss and flow rate.

[0065] The optical device 1 does not immerse any element in the liquid to be measured, which is the measurement target S, and therefore does not require the work of cleaning any element contaminated by the liquid to be measured. This reduces the need for significant labor in the maintenance work of devices related to optical measurements using the optical device 1. The optical device 1 does not require any element to be directly incorporated into the cell C, and therefore can also prevent leakage of the liquid to be measured from the cell C due to the incorporation.

[0066] The optical device 1 can further suppress the influence on the measurement target S when changing the optical path length of the portion of the optical path P that overlaps with the measurement target S, by positioning the measurement target S at the center of the frame F using the optical element block 10. When changing the optical path length, the optical device 1 can easily and quickly change the optical path length to perform optical measurement without needing to, for example, change the size of the cell C that contains the liquid to be measured as the measurement target S or make other design changes. The optical device 1 can flexibly change the optical path length.

[0067] The optical device 1 can change the optical path length by operating only the optical element block 10 without performing any operation on the measurement object S, by using the rotation mechanism 20 to rotate the optical element block 10 and change the angle of the optical element block 10 with respect to the measurement object S. This allows the optical device 1 to further reduce the influence on the measurement object S when changing the optical path length. In addition, the optical device 1 can change the optical path length by simply rotating the optical element block 10. Therefore, the optical device 1 can easily and quickly change the optical path length to perform optical measurement.

[0068] The optical device 1 has a first block 11 and a second block 12 that is rotated by a rotation mechanism 20, and thus can greatly change the optical path length of the portion of the optical path P that overlaps with the measurement target S, as shown in FIGS. 1 and 4. For example, by rotating the second block 12 by the rotation mechanism 20, the optical device 1 can change the optical path length by an integer multiple of the width of the cell C along the optical path P, which is caused by normal incidence and normal emission of light to the cell C. More specifically, the optical device 1 can change the optical path length between one and two times the width of the cell C along the optical path P.

[0069] In the optical device 1, the first block 11 has a lens 11c and a mirror 11a, and the second block 12 has a mirror 12a and a lens 12b, so that the optical elements through which light passes and causes light loss can be limited to the pair of lenses 11c and 12b. Therefore, the optical device 1 can maintain a substantially constant optical loss even if the optical path length of the portion of the optical path P that overlaps with the measurement target S is changed, for example, between the optical systems shown in FIGS. 1 and 4. Therefore, the optical device 1 can suppress a decrease in the signal intensity and the S / N ratio of light that passes through the optical device 1 and is detected. This makes it possible for the optical device 1 to easily obtain a desired signal intensity for the light used in optical measurement and easily maintain measurement accuracy in the optical measurement.

[0070] In the optical device 1, the first block 11 has the lens 11c and the mirror 11a, and the second block 12 has the mirror 12f and the lens 12d, so that the optical elements through which light passes and through which light loss occurs can be limited to the pair of lenses 11c and 12d. Therefore, the optical device 1 similarly achieves the above-mentioned effect on the measurement accuracy in optical measurement.

[0071] In the optical device 1, the first block 11 has a rectangular first frame F1, and the second block 12 has a hexagonal second frame F2, thereby improving the rotational symmetry of each frame F with respect to the cell C. This makes it possible for the optical device 1 to easily realize a plurality of different optical systems as shown in FIGS. 1 and 4 by rotating the frame F using the rotation mechanism 20.

[0072] The optical device 1 can easily perform optical measurements using an optical path P on the liquid to be measured flowing in one direction through the cell C, for example, by including the liquid to be measured contained in the cell C as the measurement target S.

[0073] In the optical device 1, the cross section of the cell C when viewed from the extension direction D of the cell C has a square shape, so that the rotational symmetry of the components including the cell C and each frame F can be improved.

[0074] In the first embodiment, the measurement target S is described as including, for example, a liquid to be measured that is contained in a cell C and flows in one direction, but is not limited to this. The measurement target S may also include, for example, a liquid to be measured that is contained in a cell C and does not flow in one direction but remains in a fixed position. The measurement target S is not limited to liquids such as the liquid to be measured, but may also include solids having any cross-sectional shape, such as a rectangle, square, other polygon, circle, or ellipse, or may also include a gas.

[0075] In the first embodiment, the optical measurement has been described as including, for example, measuring the light absorption characteristics of the measurement object S, which are indicated by an absorption spectrum, but is not limited to this. The optical measurement may also include, for example, measuring the fluorescence characteristics of the measurement object S, which are indicated by a fluorescence spectrum. The optical measurement may also include, for example, measuring the light scattering characteristics of the measurement object S, which are indicated by a scattered light spectrum.

[0076] In the first embodiment, the light is measured light from, for example, an arbitrary light source located outside the optical device 1, and includes measured light as transmitted light that enters the optical device 1 and passes through the measurement target S. However, the present invention is not limited to this. The light may also include, for example, excitation light for generating fluorescence or scattered light from the measurement target S. In this case, the optical device 1 may be configured such that some of the mirrors serving as reflecting means in the optical elements of the first block 11 and the second block 12 are replaced with wavelength separation elements, and signal light from the measurement target S based on the excitation light is extracted from each wavelength separation element. This makes the optical device 1 applicable to optical measurement techniques for the measurement target S not only as a transmission measurement device, but also as a fluorescence measurement device or a scattered light measurement device.

[0077] In the first embodiment, the optical element block 10 is described as positioning the measurement target S at the center of the frame F, but this is not limiting. The optical element block 10 may position the measurement target S at a position other than the center within the frame F.

[0078] In the first embodiment, the first block 11 has been described as having optical elements arranged as shown in Fig. 2, but this is not limiting. The arrangement and type of optical elements in the first block 11 may be any that can change the overall length of the portion of the optical path P that overlaps with the measurement target S. For example, the first block 11 does not need to have the lens 11c. In this case, any lens that has the function of making parallel light incident on the measurement target S may be arranged immediately outside the optical device 1.

[0079] In the first embodiment, the second block 12 has optical elements arranged as shown in Fig. 3, but this is not limiting. The arrangement and type of optical elements in the second block 12 may be any that can change the overall length of the portion of the optical path P that overlaps with the measurement target S. For example, the second block 12 does not need to have at least one of the lenses 12b and 12d. In this case, any lens that has the function of focusing parallel light may be arranged immediately outside the optical device 1.

[0080] In the first embodiment, the first block 11 has been described as having a rectangular first frame F1, but this is not limiting. The first frame F1 may have any shape, such as a polygon, a circle, or an ellipse, instead of a rectangular shape such as a rectangle or a square.

[0081] In the first embodiment, the second block 12 has been described as having a hexagonal second frame F2, but this is not limiting. The second frame F2 may have any shape, such as a regular hexagon, a polygon, a circle, or an ellipse, instead of a hexagonal shape.

[0082] In the first embodiment, the cross section of the cell C when viewed from the extension direction D of the cell C has a square shape, but is not limited to this. The cross section of the cell C when viewed from the extension direction D of the cell C may have any shape other than a square, such as any other quadrangle, any other polygon, a circle, or an ellipse.

[0083] In the first embodiment, the rotation mechanism 20 is attached to, for example, the second block 12 of the optical element block 10, and is described as changing the angle of the second block 12 with respect to the measurement target S by rotating the second block 12. However, the present invention is not limited to this. The rotation mechanism 20 may be attached to the first block 11 instead of or in addition to the second block 12.

[0084] (Second embodiment) 5 is a schematic diagram corresponding to FIG. 1 showing a schematic configuration of an optical device 1 according to a second embodiment of the present disclosure. The configuration and functions of the optical device 1 according to the second embodiment will be mainly described with reference to FIG. The optical device 1 according to the second embodiment differs from the first embodiment in that the optical element block 10 further includes a third block 13.

[0085] Other configurations, functions, effects, and modifications are the same as those of the first embodiment, and the corresponding explanations also apply to the optical device 1 according to the second embodiment. In the following, components that are the same as those in the first embodiment are given the same reference numerals, and their explanations will be omitted. Differences from the first embodiment will be mainly explained.

[0086] In the second embodiment, the optical element block 10 further includes a third block 13. The third block 13 is exactly the same as the first block 11 shown in Fig. 2, but is arranged relative to the cell C in a state rotated 180° with respect to the first block 11 in Fig. 5. In the second embodiment, the frame F further includes a third frame F3 included in the third block 13, in addition to the first frame F1 included in the first block 11 and the second frame F2 included in the second block 12. The third frame F3 is exactly the same as the first frame F1 and has a rectangular shape.

[0087] As shown in Figure 5, in the second embodiment, the rotation mechanism 20 is attached to, for example, the second block 12 of the optical element block 10, and changes the angle of the second block 12 relative to the measurement object S by rotating the second block 12.

[0088] 5, the optical device 1 forms an optical path P while maintaining a predetermined angle for each of the first block 11, the second block 12, and the third block 13. For example, the second block 12 maintains the angle shown in FIG. 5 after being rotated by the rotation mechanism 20.

[0089] In the side view of FIG. 5, the fifth side F25 of the second block 12 is located above the cell C. The sixth side F26 of the second block 12 is located above the front of the cell C. The first side F21 of the second block 12 is located below the front of the cell C. The second side F22 of the second block 12 is located below the cell C. The third side F23 of the second block 12 is located below the back of the cell C. The fourth side F24 of the second block 12 is located above the back of the cell C.

[0090] Mirror 12e attached to the fifth side F25 of second block 12 is disposed above cell C. Mirror 12e is disposed at an angle so as to face toward first block 11 and cell C. Mirror 12c attached to the second side F22 of second block 12 is disposed below cell C. Mirror 12c is disposed at an angle so as to face toward third block 13 and cell C. In FIG. 5, mirror 12f, the combination of mirror 12a and lens 12b, and lens 12d are located on the upper front side, lower front side, and lower back side of cell C, respectively, but these optical elements that do not directly contribute to the formation of optical path P are not shown.

[0091] In the side view of FIG. 5 , a third side F13 of the third block 13 is located above the cell C. A fourth side F14 of the third block 13 is located in front of the cell C. A first side F11 of the third block 13 is located below the cell C. A second side F12 of the third block 13 is located behind the cell C.

[0092] Mirror 11a attached to first side F11 of third block 13 is disposed below cell C at an angle so as to face the second block 12 and cell C. Lens 11c attached to third side F13 of third block 13 is disposed above cell C so as to face cell C. In FIG. 5, mirrors 11b and 11d are located on the rear and front sides of cell C, respectively, but these optical elements that do not directly contribute to the formation of optical path P are not shown.

[0093] The optical device 1 allows light to be incident on the third side F13 of the first block 11, where a lens 11c serving as a collimating means is attached. The lens 11c converts the light incident on the optical device 1 into collimated light and causes the collimated light to be incident on the measurement target S. The optical device 1 transmits the collimated light through a cell C containing a liquid to be measured as the measurement target S.

[0094] The optical device 1 causes the parallel light that has passed through the cell C to be incident on a mirror 11a that is attached to the first frame F1 in the first block 11 so as to be inclined at 45° to the left with respect to the extension direction D of the cell C. The mirror 11a reflects the parallel light that has passed through the measurement target S toward the second block 12. The mirror 11a turns the parallel light back by 90° and causes it to be incident on the second block 12.

[0095] The optical device 1 causes the collimated light reflected by the mirror 11a at 90° to be incident on the mirror 12e attached to the second frame F2 in the second block 12 so as to be tilted at 45° to the right with respect to the extension direction D of the cell C. The mirror 12e further reflects the collimated light toward the cell C, causing the collimated light to be further incident on the measurement target S. The mirror 12e corresponds to the "fourth mirror" recited in the claims. The mirror 12e reflects the collimated light by 90° and causes it to be incident on the measurement target S.

[0096] The optical device 1 causes the collimated light that has passed through the cell C to be incident on a mirror 12c that is attached to the second frame F2 in the second block 12 so as to be inclined at 45° to the right with respect to the extension direction D of the cell C. The mirror 12c further reflects the collimated light that has passed through the measurement target S toward the third block 13. The mirror 12c corresponds to the "fifth mirror" recited in the claims. The mirror 12c reflects the collimated light back by 90° and causes it to be incident on the third block 13.

[0097] The optical device 1 causes the collimated light reflected by the mirror 12c at 90° to be incident on the mirror 11a attached to the third frame F3 in the third block 13 so as to be tilted at 45° to the left with respect to the extension direction D of the cell C. The mirror 11a further reflects the collimated light toward the cell C, causing the collimated light to be further incident on the measurement target S. The mirror 11a corresponds to the "sixth mirror" recited in the claims. The mirror 11a reflects the collimated light by 90° and causes it to be incident on the measurement target S.

[0098] The lens 11c focuses the parallel light that has passed through the measurement target S. The lens 11c corresponds to the "fourth lens" in the claims. The lens 11c focuses the parallel light and guides it to a detector such as a photodetector located outside the optical device 1 or to an optical transmission path such as an optical fiber.

[0099] The optical device 1 adjusts the angle of the second block 12 using the rotation mechanism 20 so that the pair of sides parallel to the cell C is the fifth side F25 and the second side F22. As a result, the optical device 1 forms an optical path P through which light is transmitted three times through the cell C containing the liquid to be measured as the measurement target S. The optical path P is orthogonal to the cell C. That is, in each of the three transmissions, the parallel light enters one surface of the cell C perpendicularly and exits the other surface perpendicularly. The optical device 1 can also form the optical path P shown in FIGS. 1 and 4 using only the first block 11 and the second block 12 by adjusting the angle of the second block 12 using the rotation mechanism 20 as shown in FIGS. 1 and 4.

[0100] The optical device 1 further includes a third block 13 in addition to the first block 11 and the second block 12 that is rotated by the rotation mechanism 20, and is thereby able to significantly change the optical path length of the portion of the optical path P that overlaps with the measurement target S, as shown in FIG. 5 . For example, by rotating the second block 12 by the rotation mechanism 20, the optical device 1 can change the optical path length by an integer multiple of the width of the cell C along the optical path P, which is caused by normal incidence and normal emission of light to the cell C. More specifically, the optical device 1 can change the optical path length between one, two, and three times the width of the cell C along the optical path P.

[0101] In the optical device 1, the first block 11 has a lens 11c and a mirror 11a, the second block 12 has a mirror 12e and a mirror 12c, and the third block 13 has a mirror 11a and a lens 11c, so that the optical elements through which light passes and causes light loss can be limited to the pair of lenses 11c. Therefore, the optical device 1 can maintain a substantially constant optical loss even when the optical path length of the portion of the optical path P that overlaps with the measurement target S is changed. Therefore, the optical device 1 can suppress a decrease in the signal intensity and the S / N ratio of light that passes through the optical device 1 and is detected. This makes it possible for the optical device 1 to easily obtain a desired signal intensity for the light used in optical measurement and easily maintain measurement accuracy in the optical measurement.

[0102] In the optical device 1, the first block 11 has a rectangular first frame F1, the second block 12 has a hexagonal second frame F2, and the third block 13 has a rectangular third frame F3, thereby improving the rotational symmetry of each frame F with respect to the cell C. This makes it possible for the optical device 1 to easily realize a plurality of different optical systems by rotating the frame F using the rotation mechanism 20.

[0103] In the second embodiment, the third block 13 has been described as having optical elements arranged in the same manner as the first block 11 shown in FIG. 2 , but this is not limiting. The arrangement and type of optical elements in the third block 13 may be any that can change the overall length of the portion of the optical path P that overlaps with the measurement target S. For example, the third block 13 does not need to have the lens 11c. In this case, any lens that has the function of focusing parallel light may be arranged immediately outside the optical device 1.

[0104] In the second embodiment, the third block 13 has been described as having a rectangular third frame F3, but is not limited thereto. The third frame F3 may have any shape, such as a polygon, a circle, or an ellipse, instead of a rectangular shape such as a rectangle or a square.

[0105] In the second embodiment, the rotation mechanism 20 is attached to, for example, the second block 12 of the optical element block 10, and is described as changing the angle of the second block 12 with respect to the measurement target S by rotating the second block 12. However, the present invention is not limited to this. The rotation mechanism 20 may be attached to at least one of the first block 11 and the third block 13 instead of or in addition to the second block 12.

[0106] (Third embodiment) 6 is a schematic diagram corresponding to FIG. 1 showing a schematic configuration of an optical device 1 according to a third embodiment of the present disclosure. The configuration and functions of the optical device 1 according to the third embodiment will be mainly described with reference to FIG. The optical device 1 according to the third embodiment differs from the first and second embodiments in that the optical element block 10 further includes a fourth block 14.

[0107] Other configurations, functions, effects, and modifications are the same as those of the first and second embodiments, and the corresponding explanations also apply to the optical device 1 according to the third embodiment. In the following, components similar to those of the first and second embodiments are given the same reference numerals, and their explanations will be omitted. Differences from the first and second embodiments will be mainly explained.

[0108] In the third embodiment, the optical element block 10 further includes a fourth block 14. The fourth block 14 is identical to the second block 12 shown in Fig. 3, but is arranged relative to the cell C in a state rotated 60° with respect to the second block 12 in Fig. 6. In the third embodiment, the frame F further includes a fourth frame F4 included in the fourth block 14, in addition to the first frame F1 included in the first block 11, the second frame F2 included in the second block 12, and the third frame F3 included in the third block 13. The fourth frame F4 is identical to the second frame F2 and has a hexagonal shape.

[0109] As shown in Figure 6, in the third embodiment, the rotation mechanism 20 is attached to, for example, each of the second block 12 and the third block 13 of the optical element block 10, and changes the angle of the optical element block 10 relative to the measurement object S by rotating at least one of the second block 12 and the third block 13.

[0110] In the example of the optical system shown in Fig. 6, the optical device 1 forms an optical path P while maintaining a predetermined angle for each of the first block 11, the second block 12, the third block 13, and the fourth block 14. For example, the second block 12 maintains the angle shown in Fig. 6 as an example after being rotated by the rotation mechanism 20. For example, the third block 13 maintains the angle shown in Fig. 6 as an example after being rotated by the rotation mechanism 20.

[0111] In the side view of FIG. 6, the fourth side F14 of the third block 13 is located above the cell C. The first side F11 of the third block 13 is located in front of the cell C. The second side F12 of the third block 13 is located below the cell C. The third side F13 of the third block 13 is located behind the cell C.

[0112] Mirror 11b attached to the second side F12 of third block 13 is arranged at an angle below cell C so as to face the second block 12 and cell C. Mirror 11d attached to the fourth side F14 of third block 13 is arranged above cell C so as to face the fourth block 14 and cell C. In FIG. 6, mirror 11a and lens 11c are located on the front and back sides of cell C, respectively, but these optical elements that do not directly contribute to the formation of optical path P are not shown.

[0113] In the side view of FIG. 6, the sixth side F26 of the fourth block 14 is located above the cell C. The first side F21 of the fourth block 14 is located above the front of the cell C. The second side F22 of the fourth block 14 is located below the front of the cell C. The third side F23 of the fourth block 14 is located below the cell C. The fourth side F24 of the fourth block 14 is located below the back of the cell C. The fifth side F25 of the fourth block 14 is located above the back of the cell C.

[0114] Mirror 12f attached to the sixth side F26 of the fourth block 14 is disposed above cell C. Mirror 12f is disposed at an angle so as to face the third block 13 and cell C. Lens 12d attached to the third side F23 of the fourth block 14 is disposed below cell C so as to face cell C. In FIG. 6, the combination of mirror 12a and lens 12b, mirror 12c, and mirror 12e are located on the upper front side, lower front side, and upper back side of cell C, respectively, but these optical elements that do not directly contribute to the formation of optical path P are not shown.

[0115] The optical device 1 allows light to be incident on the third side F13 of the first block 11, where a lens 11c serving as a collimating means is attached. The lens 11c converts the light incident on the optical device 1 into collimated light and causes the collimated light to be incident on the measurement target S. The optical device 1 transmits the collimated light through a cell C containing a liquid to be measured as the measurement target S.

[0116] The optical device 1 causes the parallel light that has passed through the cell C to be incident on a mirror 11a that is attached to the first frame F1 in the first block 11 so as to be inclined at 45° to the left with respect to the extension direction D of the cell C. The mirror 11a reflects the parallel light that has passed through the measurement target S toward the second block 12. The mirror 11a turns the parallel light back by 90° and causes it to be incident on the second block 12.

[0117] The optical device 1 causes the collimated light reflected by the mirror 11a at 90° to be incident on a mirror 12e attached to the second frame F2 in the second block 12 so as to be inclined at 45° to the right with respect to the extension direction D of the cell C. The mirror 12e further reflects the collimated light toward the cell C, causing the collimated light to be further incident on the measurement target S. The mirror 12e reflects the collimated light by 90° and causes it to be incident on the measurement target S.

[0118] The optical device 1 causes the parallel light that has passed through the cell C to be incident on a mirror 12c that is attached to the second frame F2 in the second block 12 so as to be inclined at 45° to the right with respect to the extension direction D of the cell C. The mirror 12c further reflects the parallel light that has passed through the measurement target S toward the third block 13. The mirror 12c reflects the parallel light back by 90° and causes it to be incident on the third block 13.

[0119] The optical device 1 causes the collimated light reflected by the mirror 12c at 90° to be incident on the mirror 11b attached to the third frame F3 in the third block 13 so as to be tilted at 45° to the left with respect to the extension direction D of the cell C. The mirror 11b further reflects the collimated light toward the cell C, causing the collimated light to be further incident on the measurement target S. The mirror 11b reflects the collimated light by 90° and causes it to be incident on the measurement target S.

[0120] The optical device 1 causes the parallel light transmitted through the cell C to be incident on a mirror 11d attached to the third frame F3 in the third block 13 so as to be inclined at 45° to the left with respect to the extension direction D of the cell C. The mirror 11d reflects the parallel light transmitted through the measurement target S toward the fourth block 14. The mirror 11d turns the parallel light back by 90° and causes it to be incident on the fourth block 14.

[0121] The optical device 1 causes the collimated light reflected by mirror 11d at 90° to be incident on mirror 12f, which is attached to the fourth frame F4 in the fourth block 14 so as to be inclined at 45° to the right with respect to the extension direction D of the cell C. Mirror 12f further reflects the collimated light toward the cell C, causing the collimated light to further enter the measurement target S. Mirror 12f reflects the collimated light by 90° and causes it to enter the measurement target S.

[0122] The lens 12d focuses the parallel light that has passed through the measurement target S. The lens 12d focuses the parallel light and guides it to a detector such as a photodetector located outside the optical device 1 or to an optical transmission path such as an optical fiber.

[0123] The optical device 1 forms an optical path P through a cell C containing a liquid to be measured as the measurement target S, i.e., through the measurement target S, by transmitting light four times. The optical path P is orthogonal to the cell C. That is, in each of the four transmissions, the parallel light enters one surface of the cell C perpendicularly and exits the other surface perpendicularly. The optical device 1 can also form the optical path P shown in FIGS. 1 and 4 using only the first block 11 and the second block 12 by adjusting the second block 12 to the angle shown in FIGS. 1 and 4 using the rotation mechanism 20. The optical device 1 can also form the optical path P shown in FIG. 5 using only the first block 11 to the third block 13 by adjusting the second block 12 and the third block 13 to the angle shown in FIG. 5 using the rotation mechanism 20.

[0124] By further including the fourth block 14, the optical device 1 can significantly change the optical path length of the portion of the optical path P that overlaps with the measurement target S, as shown in FIG. 6, for example. For example, the optical device 1 can change the optical path length by an integer multiple of the width of the cell C along the optical path P due to perpendicular incidence and perpendicular emission of light to the cell C. More specifically, the optical device 1 can change the optical path length between 1, 2, 3, and 4 times the width of the cell C along the optical path P.

[0125] As described above, the optical device 1 can increase the number of times that the parallel light passes through the cell C containing the measurement object S by increasing the combination of, for example, the first block 11 shown in Figure 2 and the second block 12 shown in Figure 3.

[0126] (Fourth embodiment) Fig. 7 is a schematic diagram corresponding to Fig. 2 showing an example of the schematic configuration of the optical device 1 according to the fourth embodiment of the present disclosure. Fig. 8 is a schematic diagram corresponding to Fig. 2 showing another example of the schematic configuration of the optical device 1 according to the fourth embodiment of the present disclosure. The configuration and function of the optical device 1 according to the fourth embodiment will be mainly described with reference to Figs. 7 and 8. The optical device 1 according to the fourth embodiment differs from the first to third embodiments in that the optical element block 10 has only a first block 11, and the first block 11 has only a pair of lenses as optical elements.

[0127] Other configurations, functions, effects, and modifications are the same as those of the first to third embodiments, and the corresponding explanations also apply to the optical device 1 according to the fourth embodiment. In the following, components similar to those of the first to third embodiments are given the same reference numerals, and their explanations will be omitted. Differences from the first to third embodiments will be mainly explained.

[0128] The first block 11 has a cell C at its center, the cell C having a rectangular cross section when viewed from the extension direction D of the cell C. The first block 11 has a lens 11e attached to a first side F11. The first block 11 has a lens 11c attached to a third side F13.

[0129] 7, the lens 11e attached to the first side F11 of the first block 11 is disposed above the cell C so as to face the long side of the cell C. The lens 11c attached to the third side F13 of the first block 11 is disposed below the cell C so as to face the long side of the cell C. In this case, the optical path P is formed along the short side direction of the cell C.

[0130] The rotation mechanism 20 is attached to the first block 11. The second example of the optical system shown in FIG. 8 is obtained by rotating the first block 11 by 90° using the rotation mechanism 20. At this time, the lens 11e attached to the first side F11 of the first block 11 is arranged to face the short side of the cell C on the right side of the cell C. The lens 11c attached to the third side F13 of the first block 11 is arranged to face the short side of the cell C on the left side of the cell C. At this time, the optical path P is formed along the longitudinal direction of the cell C.

[0131] As described above, the optical device 1 can change the total length of the part of the optical path P that overlaps with the measurement object S by the difference between the short side and long side of the cell C simply by rotating the first block 11 by 90° using the rotation mechanism 20.

[0132] In the fourth embodiment, the rotation mechanism 20 is attached to the first block 11 and rotates the first block 11, but this is not limiting. The rotation mechanism 20 may be attached to the cell C instead of or in addition to the first block 11. By rotating the cell C by 90° using the rotation mechanism 20, the total length of the portion of the optical path P that overlaps with the measurement target S may be changed by the difference between the short side and the long side of the cell C.

[0133] It will be apparent to those skilled in the art that the present disclosure may be embodied in other specific forms other than the above-described embodiments without departing from the spirit or essential characteristics thereof. Therefore, the foregoing description is illustrative and not limiting. The scope of the disclosure is defined not by the foregoing description but by the appended claims. All modifications within the range of equivalents of any modifications are intended to be embraced therein.

[0134] For example, the shape, size, arrangement, orientation, and number of each of the above-described components are not limited to those illustrated in the above description and drawings. The shape, size, arrangement, orientation, and number of each component may be configured arbitrarily as long as the function can be realized. The components of the illustrated optical device 1 are functional concepts, and the specific shape of each component is not limited to those illustrated. For example, in each of the above embodiments, each mirror is illustrated as being circular, but this is not a limitation. Each mirror may have any other shape, such as a polygonal or elliptical shape. For example, in each of the above embodiments, each lens is illustrated as being elliptical, but this is not a limitation. Each lens may have any other shape, such as a polygonal or circular shape.

[0135] In each of the above embodiments, the optical device 1 may be configured to have an observation window or an imaging element attached to a predetermined side of the frame F where no optical element is attached, so that the state inside the cell C can be observed. This allows the optical device 1 to simultaneously perform both transmission measurement and image measurement.

[0136] In each of the above embodiments, the optical device 1 may be configured such that positioning pin holes are formed in the optical element block 10, and the rotation angle can be accurately reproduced by fixing the optical element block 10 with the positioning pins according to the rotation angle.

[0137] Some embodiments of the present disclosure will be described below as examples, however, it should be noted that the embodiments of the present disclosure are not limited to these examples. [Appendix 1] an optical element block having optical elements that form an optical path of light used in optical measurement, the optical element block being arranged around the measurement object so that the optical path intersects with the measurement object; a rotation mechanism that changes a relative angle between the measurement object and the optical element block so that the total length of the portion of the optical path that overlaps with the measurement object changes; Equipped with optical equipment. [Appendix 2] 10. The optical device of claim 1, the optical element block has a frame to which the optical element is attached and which surrounds the measurement object, and the measurement object is positioned at the center of the frame; optical equipment. [Appendix 3] 10. The optical device of claim 2, the rotation mechanism is attached to the optical element block and rotates the optical element block to change the angle of the optical element block with respect to the measurement target; optical equipment. [Appendix 4] 4. The optical device of claim 3, the optical element block includes a first block and a second block that is rotated by the rotation mechanism; The first block includes a first lens that makes parallel light incident on the measurement object, and a first mirror that reflects the parallel light that has passed through the measurement object toward the second block. optical equipment. [Appendix 5] 5. The optical device of claim 4, The second block includes a second mirror that further reflects the parallel light, and a second lens that condenses the reflected parallel light. optical equipment. [Appendix 6] 6. The optical device according to claim 4 or 5, The second block includes a third mirror that further reflects the parallel light to make the parallel light further incident on the measurement object, and a third lens that condenses the parallel light that has passed through the measurement object. optical equipment. [Appendix 7] 7. The optical device according to any one of claims 4 to 6, the optical element block further includes a third block; the second block includes a fourth mirror that further reflects the collimated light to make the collimated light further incident on the measurement object, and a fifth mirror that further reflects the collimated light that has passed through the measurement object toward the third block; the third block includes a sixth mirror that further reflects the collimated light and makes the collimated light further incident on the measurement object, and a fourth lens that condenses the collimated light that has passed through the measurement object. optical equipment. [Appendix 8] 8. The optical device of claim 7, the frames include a first frame, a second frame, and a third frame; the first block has the first frame in a rectangular shape, the second block has the second frame in a hexagonal shape, The third block has the third frame having a rectangular shape. optical equipment. [Appendix 9] 9. The optical device according to any one of claims 1 to 8, The measurement object includes a test liquid contained in a cell. optical equipment. [Appendix 10] 10. The optical device of claim 9, The cross section of the cell when viewed from the stretching direction of the cell has a square shape. optical equipment. [Explanation of symbols]

[0138] 1 Optical device 10 Optical element block 11 Block 1 11a Mirror (1st mirror, 6th mirror) 11b Mirror 11c lens (1st lens, 4th lens) 11d mirror 11e lens 12 Block 2 12a Mirror (2nd mirror) 12b lens (second lens) 12c Mirror (5th Mirror) 12d lens (third lens) 12e Mirror (4th Mirror) 12th floor mirror (third mirror) 13 Block 3 14 4th Block 20 Rotation mechanism C Cell D Stretching direction F Frame F1 1st Frame F11 First side F12 Second side F13 Third side F14 4th side F2 2nd frame F21 First side F22 2nd side F23 Third side F24 4th side F25 5th side F26 Side 6 F3 3rd frame F4 4th frame P light path S Measurement target

Claims

1. an optical element block including an optical element that forms an optical path of light used in optical measurement and a frame to which the optical element is attached, the optical element block surrounding the measurement object and positioning the measurement object inside the frame so that the optical path intersects with the measurement object; a rotation mechanism that changes a relative angle between the measurement object and the optical element block so that an optical path length of a portion of the optical path that overlaps with the measurement object changes, thereby changing the optical path length by an integer multiple of a width along the optical path of a cell through which the measurement object flows, or by a difference between a short side and a long side of the cell; Equipped with optical equipment.

2. 2. The optical device according to claim 1, The optical element block positions the measurement object at the center of the frame. optical equipment.

3. 3. The optical device according to claim 2, the rotation mechanism is attached to the optical element block and rotates the optical element block to change the angle of the optical element block with respect to the measurement target; optical equipment.

4. 4. The optical device according to claim 3, the optical element block includes a first block and a second block that is rotated by the rotation mechanism; the first block includes a first lens that makes parallel light incident on the measurement object, and a first mirror that reflects the parallel light that has passed through the measurement object toward the second block. optical equipment.

5. 5. The optical device according to claim 4, The second block includes a second mirror that further reflects the parallel light, and a second lens that condenses the reflected parallel light. optical equipment.

6. 6. The optical device according to claim 4, the second block includes a third mirror that further reflects the collimated light to make the collimated light further incident on the measurement object, and a third lens that condenses the collimated light that has passed through the measurement object. optical equipment.

7. 6. The optical device according to claim 4, the optical element block further includes a third block; the second block includes a fourth mirror that further reflects the collimated light to make the collimated light further incident on the measurement object, and a fifth mirror that further reflects the collimated light that has passed through the measurement object toward the third block, the third block includes a sixth mirror that further reflects the collimated light to make the collimated light further incident on the measurement object, and a fourth lens that condenses the collimated light that has passed through the measurement object. optical equipment.

8. 8. The optical device according to claim 7, the frames include a first frame, a second frame, and a third frame; the first block has the first frame having a rectangular shape, the second block has the second frame in a hexagonal shape, the third block has the third frame in a rectangular shape; optical equipment.

9. 6. An optical device according to any one of claims 1 to 5, The measurement object includes a test liquid contained in the cell. optical equipment.

10. 10. The optical device according to claim 9, The cross section of the cell when viewed from the stretching direction of the cell has a square shape. optical equipment.

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