Optical device

Abstract

Provided is an optical device in which a two-dimensionally distributed sample, a single condenser lens, a dichroic mirror array in which a plurality of dichroic mirrors are arranged, and an area sensor are arranged in this order along the optical axis of the condenser lens, the direction in which the plurality of dichroic mirrors are arranged is perpendicular to the optical axis, and an image of a measurement area on the sample is measured by dividing the image into a plurality of images having different wavelength components on the area sensor. The dichroic mirror array is closer to the area sensor in comparison to the condenser lens.

Description

[Technical field]

[0001] The present invention relates to an optical system and image Spectral imaging is performed by imaging a measurement target distributed in two or three dimensions using a sensor, while simultaneously acquiring the spectral information of each pixel. optics Regarding the device. [Background technology]

[0002] Spectral imaging is an important technology that is used in various scientific and industrial fields, such as identifying foreign substances mixed in food manufacturing processes, detecting strong ultraviolet rays emitted from galaxies 10 billion light years away, identifying the location of nuclei, mitochondria, and actin in cells, mapping the types of minerals on the Earth's surface from satellites, and identifying the area to be resected during colon cancer surgery.

[0003] Any optical system can be used for spectral imaging, including a microscope objective lens, a telescope telephoto lens, or a general camera lens. In the fields of bioanalysis and in vitro diagnosis, spectral imaging using a microscope objective lens is widely used and is applied to next-generation sequencers, digital PCR, flow cytometers, immunohistochemistry, etc.

[0004] For example, next-generation sequencers can perform large-scale DNA sequencing by imaging a sample in which many colonies are distributed on a two-dimensional plane with a fluorescence microscope and identifying which of the four fluorophores corresponding to the four bases each colony emits fluorescence from.In addition, in immunohistochemistry, cancer is diagnosed and treatment plans are determined by imaging the presence and localization of multiple tumor markers in tissue sections with an optical microscope.

[0005] Various methods have been proposed and put to practical use for spectral imaging. Spectral imaging measurement methods can be classified into four types: (1) point scanning method, (2) line scanning method, (3) wavelength scanning method, and (4) snapshot method.

[0006] In the point scan method, the light from one point in the measurement area is measured spectroscopically at one time. Location across the entire measurement area distributed two-dimensionally Two-dimensional By scanning, spectral information of the entire measurement area distributed two-dimensionally is obtained. In the line scanning method, the light from one line in the measurement area distributed two-dimensionally is measured at a time, and the spectral information of the one line is obtained. Location across the entire measurement area distributed two-dimensionally One-dimensional By scanning, spectral information of the entire two-dimensionally distributed measurement area is obtained. With the wavelength scanning method, the light from the entire two-dimensionally distributed measurement area is measured for one wavelength at a time, and by scanning this one wavelength across all measurement wavelengths, spectral information of the entire two-dimensionally distributed measurement area is obtained. With the snapshot method, spectral information of the light from the entire two-dimensionally distributed measurement area is obtained at one time without scanning.

[0007] When described in this way, the snapshot method seems to be the best, but this is not necessarily the case. In all of these measurement methods, there is a trade-off between various performances such as time resolution, spatial resolution, wavelength resolution, and field of view size. For example, Image Sensor When comparing the snapshot method and the wavelength scanning method using the same spatial and wavelength resolution, the snapshot method has a better time resolution, but the field of view size of the measurement area is smaller.

[0008] In addition, there are various methods within each measurement method, and depending on the configuration of each device, there are advantages and disadvantages in terms of the size and cost of the device, in addition to the above-mentioned performance. Therefore, it is important to select an appropriate measurement method and device depending on the purpose of spectral imaging.

[0009] As one of the snapshot methods, an image splitting method using a dichroic mirror has been put to practical use. The image splitting method is characterized by high sensitivity because it can use both the transmitted and reflected light of the light incident on the dichroic mirror with high efficiency.

[0010] As spectral imaging devices using the image splitting method, for example, CAIRN Research's MultiSplit V2 and Optical Insights' Quad-View are commercially available. Digital camera, or image sensor In contrast, by inserting these devices between the microscope and the digital camera, i.e., the microscope, the image division type spectral imaging device, Image Sensor By connecting the three-dimensional and two-dimensionally distributed sample measurement area in this order, it is possible to divide the area into up to four images with four different wavelength bands and measure them simultaneously.

[0011] In this specification, different wavelength bands are sometimes called different colors, and four different wavelength bands are sometimes called four colors. Samples are distributed in two or three dimensions measurement area , or, Samples distributed in two or three dimensions of , and onwards is 2 These devices are sometimes called two-dimensionally distributed samples, or simply samples. In other words, in this specification, "two-dimensionally distributed" does not exclude three-dimensional distribution. Image Sensor It is characterized by its ability to simultaneously perform up to four-division, four-color imaging of the sample measurement area.

[0012] The configuration of the above-mentioned image-splitting type spectral imaging device is shown in Figure 9 of Patent Document 1. Light from a two-dimensionally distributed measurement area O of a sample is focused by a first focusing lens 14 and a first imaging lens 16, and a primary image 18 of the measurement area O is formed on a first aperture 20. A first aperture of an appropriate size is provided at an appropriate position on the first aperture 20.

[0013] Of the light from the primary image 18, the light that can pass through the first aperture is collimated by the second condenser lens 24, passes through the second aperture provided in the second diaphragm 29, and enters the dichroic mirror (dichroic filter) 60 that is inclined at 45° to the light traveling direction. 60 The two split transmitted and reflected lights are then focused by the second imaging lens 34 via the mirror 28 and the filter 30. Image Sensor Two secondary images with different wavelength components of the measurement area O are imaged at different positions on the Image Sensor 36, they are formed at different positions so as not to overlap each other. That is, FIG. 9 shows one dichroic mirror and one Image Sensor 9, two-part two-color imaging of the measurement area of ​​the sample distributed two-dimensionally is performed. Here, as shown in Fig. 9, each of the two-part transmitted light and reflected light is incident on the second imaging lens 34 at an angle to the optical axis A by the mirror 28.

[0014] In a device configuration similar to that shown in FIG. 9, the number of splits and the number of colors can be increased by increasing the number of dichroic mirrors. For example, by combining two dichroic mirrors, the incoming light can be split into three outgoing lights with different wavelength components, so that the number of splits and the number of colors can be increased by combining two dichroic mirrors. Image Sensor By using a dichroic mirror, it is possible to simultaneously perform three-division, three-color imaging of the measurement area of ​​a sample distributed two-dimensionally. Alternatively, by combining three dichroic mirrors, the incoming light can be split into four outgoing lights with different wavelength components, so that one Image Sensor By using this method, it is possible to simultaneously perform four-division, four-color imaging of the measurement area of ​​a two-dimensionally distributed sample.

[0015] One of the features of the above-mentioned spectral imaging device using the image splitting method with a dichroic mirror is that the light from the measurement area of ​​the sample distributed two-dimensionally is imaged first just before it enters the dichroic mirror, and an aperture and stop are provided at that position. Image Sensor This is because different divided images overlap on the screen, making it impossible to measure each divided image independently.

[0016] Patent document 2 shows an apparatus configuration in which the measurement target is not a two-dimensionally distributed sample, but multiple samples that are multiple light-emitting points that make up an array of light-emitting points, and by using a dichroic mirror array in which multiple dichroic mirrors are arranged, the light emitted from each light-emitting point is detected in multiple colors with high sensitivity and independently.

[0017] That is, the multicolor detection device of Patent Document 2 is different from the image-splitting type spectral imaging device of Patent Document 1, but they have in common the point that they split the light from the measurement object into light of multiple wavelength components by combining multiple dichroic mirrors, and perform high-efficiency and simultaneous multicolor detection. Furthermore, Patent Document 2 has achieved a miniaturized and low-cost multicolor detection device.

[0018] FIG. 7 of Patent Document 2 shows an example of the configuration of a four-color detection device. As shown in FIG. 7(a), light emitted from four light-emitting points 1 (light-emitting point array) arranged at equal intervals on a straight line is focused by four similarly arranged focusing lenses 2 (focusing lens array) to become light beams 9, which are transmitted through one long-pass filter 10. Also, as shown in FIG. 7(b), the four light beams 9 are split into light beams 21, 22, 23, and 24 each having four different wavelength components by a dichroic mirror array (four types of dichroic mirrors 17, 18, 19, and 20 are arranged in a direction perpendicular to both the direction in which the four focusing lenses 2 are arranged and the optical axis direction of the focusing lenses 2), and a total of 16 light beams are split into one long-pass filter 10. Image Sensor It enters at 30.

[0019] Furthermore, as shown in Fig. 7(c), each of the 16 light beams is Image Sensor Over 30 different positions 4 sets Emitting point images 25, 26, 27, and 28 are formed and are measured independently and simultaneously. In other words, four-color detection of the emission from the four emitting points is performed simultaneously. In order to measure the emission from each emitting point with high sensitivity, it is effective to reduce the focal length of the condenser lens, for example, as shown in [Equation 6]. Also, in order to measure the emission from each emitting point independently, it is effective to reduce the optical path length of the light beam with the longest optical path length among the multiple split light beams, and to reduce the image magnification of each emitting point image, for example, as shown in [Equation 17]. In other words, the emitting point array, condenser lens array, dichroic mirror array, Image Sensor It is effective to place the color sensors close to each other and reduce the size of the multi-color detection device composed of them.

[0020] In addition, as described in

[0065] of Patent Document 2, the aperture width is defined as the maximum width of the parallel light beam that can be divided by the dichroic mirror array as designed, that is, the maximum width of the parallel light beam that can be divided without vignetting inside the dichroic mirror array. Increasing the aperture width is important for ensuring the amount of light and improving sensitivity.

[0021] As is clear from a comparison of Figures 14 and 15 of Patent Document 2, when multiple dichroic mirrors of the same size are arranged at equal intervals, it has been shown that the aperture width can be made larger by arranging the dichroic mirrors in a staggered stepped pattern rather than arranging them on the same plane.

[0022] On the other hand, in Patent Document 2, as shown in FIG. 24(a), the multiple split lights generated by the dichroic mirror array are Image Sensor Since the optical path length to the target is different, the images of all the split lights are On the image sensor It is not possible to focus the images of all the split lights. However, as shown in Figure 24(b), by inserting optical path length adjustment elements of different lengths into the optical paths of the multiple split lights, it is possible to adjust each optical path length to be equal, and to focus the images of all the split lights.

[0023] In the multi-color detection device of Patent Document 2, increasing the number of dichroic mirrors and increasing the number of divisions and the number of colors to be detected simultaneously increases the maximum optical path length among the optical path lengths of the multiple divided lights and also increases the optical path length difference, which is the difference between the maximum optical path length and the minimum optical path length, making it impossible to measure the light emission from the multiple light-emitting points independently or making it difficult to focus on all of the divided images of the light emission from the multiple light-emitting points.

[0024] In contrast, in Patent Document 3, in order to solve the above problem, as shown in FIG. 2 In this case, instead of arranging them in one direction as in the case of the dichroic mirror array, they are arranged in two opposite directions. In a multicolor detection device using a dichroic mirror array with this configuration, the maximum optical path length and optical path length difference can be halved, so it is possible to use a larger number of dichroic mirrors and increase the number of divisions and the number of colors to be detected simultaneously.

[0025] FIG. 29 of Patent Document 3 shows an example of the configuration of a nine-color detection device. Five dichroic mirrors are arranged in the first row from the center to the right, and five dichroic mirrors are arranged in the second row from the center to the left. In other words, a dichroic mirror array including a total of 10 dichroic mirrors is shown. Patent Document 2 Similarly, a large aperture width is ensured by arranging each dichroic mirror in a stepped manner. [Prior art documents] [Patent documents]

[0026] [Patent Document 1] U.S. Pat. No. 5,982,497 [Patent Document 2] Patent No. 6820907 [Patent Document 3] International Publication No. 2020 / 075293 Brochure Summary of the Invention [Problem to be solved by the invention]

[0027] Image-splitting spectral imaging devices, such as that shown in Figure 9 of Patent Document 1, have been commercialized and put to practical use. Since they use one or more dichroic mirrors to split the light, they are characterized by high light utilization efficiency and high sensitivity.

[0028] However, the problem is that the device is large, complex, and expensive. Color The maximum number is four, and it is difficult to increase the number to five or more.

[0029] The reason for this will be explained below using as an example the case where FIG. 9 of Patent Document 1 is expanded to four-split, four-color imaging by using a combination of three dichroic mirrors.

[0030] The primary image 18 of the measurement area O of the two-dimensionally distributed sample is a microscope image, Image Sensor The image is enlarged to a size of 36, for example, 10 mm square. To perform 4-division 4-color imaging, the size of the first aperture is Image Sensor The size of the primary image 18 is 1 / 4 of that of the primary image 36, for example, 5 mm square, and the secondary image is made to be an equal-magnification image of the primary image 18 by the second condenser lens 24 and the second imaging lens. In other words, four 5 mm square secondary images having four types of wavelength components are projected onto a 10 mm square image. Image Sensor 36, so as not to overlap each other.

[0031] Here, in Figure 9 of Patent Document 1, a total of four 5 mm square secondary images are arranged, two in the vertical direction (y-axis direction) and two in the depth direction (x-axis direction). Therefore, since the second focusing lens 24 needs to efficiently and uniformly collimate the light emitted from the 5 mm square area, the diameter of the collimated light beam must be at least 10 mm. Also, in order to split a collimated light beam with a diameter of 10 mm or more into four light beams with diameters of 10 mm or more so that they do not overlap each other, the central axis of each split light beam needs to be at least 5 mm away from the optical axis A.

[0032] Since each dichroic mirror is tilted at 45° with respect to the optical axis A, each must be at least 14 mm square. In this case, the space within 15 mm from the optical axis A is almost filled with one of the four light beams. Furthermore, as shown in Figure 9 of Patent Document 1, each of the split light beams is incident on the second imaging lens 34 from a position 10 mm or more away from the optical axis A, at an angle to the optical axis A. As a result, Second The four secondary images formed by the imaging lens 34 are Image Sensor 36 in different positions on the screen, so that they do not overlap each other.

[0033] Starting from the above conditions, let us assume that at least one dichroic mirror is added and 5-split 5-color imaging is performed. In order to split a collimated light beam with a diameter of 10 mm or more into 5 light beams with diameters of 10 mm or more without overlapping each other, the central axis of one of the split light beams must be at least 20 mm away from the optical axis A.

[0034] In this case, the angle at which the light beam is incident on the second imaging lens 34 becomes significantly larger than in the case of four-division four-color imaging. As a result, the secondary image of the light beam is partially Image Sensor It doesn't fit into 36, Image Sensor The image distortion is large even in the portion that is within 36, and the image quality is reduced. The same applies to imaging with 5 divisions and 5 colors or more.

[0035] Patent Document 2 provides a multi-color detection device that measures multiple samples of an array of light-emitting points, rather than spectral imaging of a measurement area of ​​a sample distributed two-dimensionally. When this multi-color detection device is used for spectral imaging of the measurement areas of multiple samples, each of which is distributed two-dimensionally, , minutes Divided Measurement area The image is On the image sensor They overlap each other, making it impossible to measure each divided image independently.

[0036] The above reasons will be explained using the detailed configuration of the multi-color detection device shown in FIGS. 7 and 15 in accordance with the specification of Patent Document 2.

[0037] Four light-emitting points 1 with a diameter of 0.075 mm are arranged at intervals of 1 mm, and four condenser lenses 2 with a focal length of 1.5 mm and an effective diameter of 1 mm are arranged at intervals of 1 mm, and the light emitted from each light-emitting point 1 is condensed by each condenser lens 2. Each condensed light beam passes through a long-pass filter 10 with a width of 2.5 mm, a thickness of 1 mm, and a depth of 5 mm, and is divided into four by a dichroic mirror array consisting of dichroic mirrors 17, 18, 19, and 20 with a width of 2.5 mm, a thickness of 1 mm, and a depth of 5 mm.

[0038] In FIG. 15 of Patent Document 2, the horizontal arrangement interval of dichroic mirrors 17, 18, 19, and 20 is x=2.5 mm, dichroic mirror 18 is shifted upward (toward the focusing lens 2) by y=0.7 mm from dichroic mirror 17, dichroic mirror 19 is shifted upward by z=0.3 mm from dichroic mirror 18, and dichroic mirror 20 is shifted upward by z=0.3 mm from dichroic mirror 19. In this case, the aperture width 63 of the dichroic mirror array is 1.3 mm. The aperture width in the direction perpendicular to the paper surface of FIG. 15 of Patent Document 2 (depth direction) is 5 mm, which is the same as the depth of each dichroic mirror. Therefore, it is possible to increase the aperture width in the depth direction by increasing the depth of each dichroic mirror.

[0039] As a result of the above, condenser lens 2 and Image Sensor The maximum optical path length 64 between the two points 30 is 21 mm. In this case, each light emitting point 1 with a diameter of 0.075 mm has an image magnification of 13 times. Image Sensor The light-emitting point images are focused on the surface of the substrate 30, and each light-emitting point image has a diameter of 0.98 mm. The spacing between the 16 light-emitting point images in total is 1 mm in the light-emitting point array direction (the vertical direction in Fig. 7(c) of Patent Document 2), and 2.5 mm in the division direction (the horizontal direction in Fig. 7(c)). Therefore, the light-emitting point images do not overlap with each other, and each can be measured independently.

[0040] However, when the diameter of the light-emitting point 1 becomes 0.085 mm or more, the diameter of the light-emitting point image becomes 1.1 mm or more, so the light-emitting point images in the light-emitting point array direction overlap each other. Also, when the diameter of the light-emitting point 1 becomes 0.2 mm or more, the diameter of the light-emitting point image becomes 2.6 mm or more, so the light-emitting point images in the division direction also overlap each other. When the light-emitting point images overlap each other in this way, it becomes impossible to measure them independently.

[0041] On the other hand, the measurement area of ​​the sample distributed two-dimensionally is the above-mentioned emission point 1. Increased Therefore, when the above multi-color detector is used for spectral imaging of a measurement area of ​​a sample distributed in two dimensions, Image Sensor The images divided above overlap each other, making it impossible to measure each divided image independently.

[0042] Next, consider applying the dichroic mirror array shown in Patent Document 2 to the image-splitting type spectral imaging device of Patent Document 1. Specifically, in Figure 9 of Patent Document 1, the set of second diaphragm 29 and second aperture, dichroic mirror 60, mirror 28, and filter 30 is replaced with the set of long-pass filter 10 shown in Figure 15 of Patent Document 2, and the dichroic mirror array consisting of dichroic mirrors 17, 18, 19, and 20.

[0043] 9 of Patent Document 1, the light beam collimated by the second focusing lens 24 traveling to the right (positive direction of the z-axis) is first arranged to be perpendicularly incident on the long-pass filter 10, and then incident on the dichroic mirror 17 at 45°. In other words, the long-pass filter 10 and the dichroic mirror 17 are arranged on the optical axis A, and the dichroic mirrors 18, 19, and 20 are arranged in this order below the optical axis A (negative direction of the y-axis).

[0044] The light beam that passes through the long-pass filter 10 is Divided into four by a dichroic mirror array 。The light beam transmitted through the dichroic mirror 17 travels to the right on the optical axis A, while the other three light beams travel to the right below the optical axis A along the optical axis A. Image Sensor The 36 positions are arranged so that their centers coincide with the centers of the four quartered light beams.

[0045] When performing four-division, four-color imaging of a measurement area of ​​a two-dimensionally distributed sample using an apparatus configured as described above, the following problems arise.

[0046] The first problem is that the light beam collimated by the second condenser lens 24 has a diameter of 10 mm or more, as mentioned above, while the aperture width 63 of the dichroic mirror array is only 1.3 mm, as mentioned above, so the utilization efficiency is 13% or less. Spectral Imaging Device The sensitivity is reduced. Since the aperture width in the depth direction (x-axis direction) in FIG. 9 of Patent Document 1 can be expanded to 10 mm or more, it is assumed that there is no reduction in utilization efficiency due to the aperture width in the depth direction.

[0047] The second problem is that the four divided light beams are all parallel to the optical axis A, so they are focused by the second imaging lens 34. Image Sensor The problem with this method is that the four divided secondary images are superimposed on one another, resulting in the inability to measure each divided image independently.

[0048] Next, to avoid the second problem, the second imaging lens 34 is eliminated, and the primary image 18 is directly captured by the second focusing lens 24. Image Sensor It is assumed that the image is formed at 1:1 magnification on the 36. The secondary image is divided into four parts. (i.e., in this case, the primary image divided into four parts) The size of the 4-part secondary stencil is 5 mm square, as mentioned above. (1st order) The image spacing is 2.5 mm, which is the same as the spacing between the four dichroic mirrors. (1st order)The problem is that the images overlap each other, making it impossible to measure each divided image independently. [Means for solving the problem]

[0049] An example of an optical device according to the present invention is A two-dimensionally distributed sample, a single focusing lens, and a dichroic mirror array with multiple dichroic mirrors. Image Sensor are arranged in this order along the optical axis of the condenser lens, The direction in which the plurality of dichroic mirrors are arranged is perpendicular to the optical axis, An image of a measurement area on the sample is Image Sensor The measurement is divided into multiple images with different wavelength components. In optical devices, The dichroic mirror array is arranged to focus the light more precisely than the condenser lens. Image Sensor It is characterized by its close proximity to

[0050] An example of an optical device according to the present invention is In the right-handed XYZ Cartesian coordinate system, The sample is distributed two-dimensionally parallel to the YZ plane, a single focusing lens whose optical axis coincides with the X axis, a dichroic mirror array in which m dichroic mirrors are arranged in parallel to each other in the Y axis direction, where m is an integer equal to or greater than 2, and Image Sensor and are arranged in the above order along the positive X-axis direction. An image of a measurement area on the sample is Image Sensor In the optical device that divides the image into m images with different wavelength components and measures them, The aperture of the dichroic mirror array provided in the diaphragm is located on the X-axis, on the side of the condenser lens, and adjacent to the dichroic mirror array; The condenser lens and Image Sensor Let h be the distance in the X-axis direction, and x be the distance in the X-axis direction between the condenser lens and the aperture.

number

[0051] The present invention enables spectral imaging using the snapshot method, in which an image containing spectral information for each point in a measurement area of ​​a two-dimensionally distributed sample is obtained in one go without scanning, using equipment that is smaller, simpler, and lower cost than conventional methods.

[0052] Also, this optics The device is capable of highly sensitive spectral imaging because it utilizes light from the measurement area with high efficiency.

[0053] Furthermore, optics The device is equipped with five or more colors in five or more wavelength bands. Spectrum Imaging is possible.

[0054] Therefore, this optics The device can be applied to spectral imaging carried out in various scientific and technological fields and industrial sectors, and can contribute to the development of these fields.

[0055] Problems, configurations and effects other than those described above will become apparent from the following description of the embodiments. [Brief description of the drawings]

[0056] [Figure 1] Schematic of the optical setup with three light-emitting regions imaged [Diagram 2] Schematic of an optical setup with an aperture in the center of the optical setup, in which three emitting regions are imaged. [Diagram 3] Schematic diagram of an optical setup with an aperture and a dichroic mirror in the center, in which three light-emitting regions are imaged. [Figure 4] Schematic diagram of an optical setup with an aperture and two dichroic mirrors in the center, in which three light-emitting regions are imaged. [Diagram 5] Schematic diagram of an optical setup with an aperture and three dichroic mirrors in the center, in which three light-emitting regions are imaged. [Figure 6] Schematic diagram of an optical setup with an aperture near the image sensor, in which three luminous regions are imaged. [Figure 7] Schematic diagram of an optical setup in which an aperture and a dichroic mirror are placed near the image sensor, imaging three light-emitting regions. [Figure 8] Schematic diagram of an optical setup in which an aperture and two dichroic mirrors are placed near an image sensor, imaging three light-emitting regions. [Figure 9] Schematic diagram of an optical setup in which an aperture and three dichroic mirrors are placed near an image sensor, imaging three light-emitting regions. [Figure 10] First notational setting of a schematic diagram of an optical device with an aperture and an emitting region imaged [Figure 11] A modified version of FIG. 7 of Patent Document 2 aligned with the first notation setting [Figure 12] Second representation of a schematic diagram of an optical device with an aperture and an emitting region imaged [Figure 13] Schematic diagram of a snapshot-based spectral imaging device that combines laser excitation and epifluorescence microscopy. [Figure 14] Detailed view of the spectral imaging device in Figure 13 [Figure 15] 4-dichoric mirror array and peripheral details [Figure 16] A graph showing the change in E versus x with y as a parameter [Figure 17] A graph showing the change in E with respect to y, with x as a parameter [Figure 18] Schematic diagram of two-dimensionally distributed sample planes [Figure 19] Schematic diagram of measurement areas 50 distributed two-dimensionally on a sample plane [Figure 20] Schematic diagram of a four-part image of the measurement area 50 [Figure 21] Schematic diagram of a four-color, four-division image of the measurement area 50 [Figure 22] Schematic diagram of measurement areas 56 distributed two-dimensionally on a sample plane [Figure 23] Schematic diagram of 4-color 4-division image of measurement area 56 [Figure 24] Schematic diagram of two-dimensionally distributed measurement areas 56(1) on a sample plane [Diagram 25] Schematic diagram of two-dimensionally distributed measurement areas 56(2) on a sample plane [Figure 26] Schematic diagram of two-dimensionally distributed measurement areas 56(3) on a sample plane [Figure 27] Schematic diagram of two-dimensionally distributed measurement areas 56(4) on a sample plane [Figure 28] Schematic diagram of two-dimensionally distributed measurement areas 56(5) on a sample plane [Figure 29] Schematic diagram of the four-part image of measurement area 56(1) [Diagram 30] Schematic diagram of the four-part image of measurement area 56(2) [Diagram 31] Schematic diagram of the four-part image of measurement area 56(3) [Diagram 32] Schematic diagram of the four-part image of measurement area 56(4) [Diagram 33] Schematic diagram of the four-part image of measurement area 56(5) [Diagram 34] A detailed view of the 4-division dichroic mirror array with an optical path length adjustment element inserted and the surrounding area [Diagram 35] A detailed view of the 4-dichoric mirror array and its periphery, with an optical path length adjustment element with a light-absorbing thin film inserted. [Diagram 36] 9-dichroic mirror array and peripheral details [Figure 37] A detailed view of the 9-segment dichroic mirror array and its periphery, with an optical path length adjustment element with a light-absorbing thin film inserted. [Figure 38] Optical path length adjustment element with a light absorbing thin film observed from the image sensor side [Figure 39]Schematic diagram of measurement areas 84 distributed two-dimensionally on a sample plane [Diagram 40] Schematic diagram of 9-division image of measurement area 84 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0057] [overview] The light from the measurement area of ​​the sample distributed two-dimensionally is collected by a single condenser lens. Image Sensor Optical imaging of the measurement area by focusing an image onto the Device In this case, a single focusing lens and Image Sensor A dichroic mirror array is arranged between the measurement area and the measurement area, and m dichroic mirrors (m is an integer of 2 or more) are arranged between the measurement area and the measurement area. The light from the measurement area is divided into m light beams having different wavelength components. Image Sensor Spectral imaging of the measurement area is performed by imaging at different positions on the

[0058] In optical devices , a dichroic mirror array and Image Sensor No lens is placed between the dichroic mirrors. Image Sensor More specifically, the aperture of the dichroic mirror array is positioned closer to the Image Sensor The m dichroic mirrors of the dichroic mirror array are arranged close to each other. The aperture diameter in the direction in which the m dichroic mirrors are arranged is made smaller than the effective diameter of a single focusing lens. The m dichroic mirrors may include simple mirrors with low wavelength dependency. A single focusing lens does not necessarily mean a single lens, but may also mean a structure equivalent to a single focusing lens (for example, a compound lens or a combination lens that combines multiple single lenses).

[0059] In this specification, the right-handed XYZ Cartesian coordinate system is defined as follows: optics The structure of the device is clarified. The principal point of the single condenser lens is the origin. The optical axis of the single condenser lens is the X-axis, and the positive direction of the X-axis is the direction from the measurement area of ​​the sample toward the single condenser lens, and the positive direction of the X-axis is the direction from the measurement area of ​​the sample toward the single condenser lens. Image Sensor The direction is defined as the direction toward the x-axis. Also, the y-axis and z-axis are taken perpendicular to the optical axis of a single focusing lens, and the direction in which the m dichroic mirrors that make up the dichroic mirror array are arranged is defined as the y-axis. The incidence surface of each dichroic mirror is inclined at 45° with respect to the x-axis and y-axis, and is parallel to the z-axis. Also, a dichroic mirror array may include a filter whose incidence surface is perpendicular to the x-axis, or a filter whose incidence surface is perpendicular to the y-axis.

[0060] The effective diameter of a single condenser lens is D. Image Sensor The distance is the sensor distance h. That is, Image Sensor The X coordinate of is h. An opening is provided at the entrance where the light beam formed by condensing the light from the measurement area with a single condenser lens enters the dichroic mirror array, that is, on the side of the single condenser lens rather than the dichroic mirror array. The dichroic mirror array and the opening are assumed to be close to each other.

[0061] In addition, "the dichroic mirror array and the aperture are close to each other" means that, for example, the distance between the dichroic mirror array and the aperture is Image Sensor This means, but is not limited to, that the distance is sufficiently shorter than the distance between the dichroic mirror array and the focusing lens or the distance between the dichroic mirror array and the focusing lens.

[0062] Generally, an "aperture" is a "physical hole" that is provided in an "aperture" that blocks light and that allows light to pass through. In this specification, the part that blocks light is called the "aperture" and the part that passes light is called the "aperture" to distinguish between the two. The aperture and the aperture are on the same plane perpendicular to the X-axis. The aperture and the dichroic mirror into which the light beam is first incident out of the m dichroic mirrors are placed on the X-axis.

[0063] On the other hand, in Patent Document 2, the "aperture width" of the dichroic mirror array is defined as follows: "Aperture width" is the width at which the dichroic mirror array can split the incoming light beam as designed. parallelIt is the maximum width of the light beam. In other words, the maximum width of the parallel light beam that is split and emitted without being partially vignetted inside the dichroic mirror array is the "aperture width."

[0064] An opening equivalent to this aperture width is called a "virtual hole" in contrast to a "physical hole." The "virtual hole" is also assumed to be placed in the same position and in the same orientation as the "physical hole." In other words, the "virtual hole" and "physical hole" are perpendicular to the X-axis and are located at the entrance where the light beam formed when the light from the measurement area is focused by a single focusing lens enters the dichroic mirror array, that is, on the side of the single focusing lens rather than the dichroic mirror array, and the dichroic mirror array, the "virtual hole" and the "physical hole" are in close proximity to each other.

[0065] Based on the above, in this specification, the smaller of the "physical hole" and the "virtual hole" is defined as the "aperture." In other words, the smaller of the size of the "physical hole" and the size of the "virtual hole" is defined as the "aperture width."

[0066] However, the size and width of the hole are defined separately in the Y-axis and Z-axis directions. In other words, the "aperture width" in one direction may be the size of a "physical hole," and the "aperture width" in the other direction may be the size of a "virtual hole." Also, even when the "aperture" is a "virtual hole," there is a "virtual aperture" outside the "virtual hole" that blocks light. Hereinafter, the expressions "physical" and "virtual" will be omitted. Here, the distance between a single focusing lens and the aperture is defined as the aperture distance x. In other words, the X coordinate of the aperture is x. The width of the aperture in the Y-axis direction is defined as the aperture width w, and the width of the aperture in the Z-axis direction is defined as the aperture width v.

[0067] With the above definition, the above-mentioned "dichroic mirror array is more efficient than a single focusing lens" Image Sensor"Placing it closer" can be expressed as h / 2 < x < h. Also, "making the aperture diameter in the arrangement direction of the m dichroic mirrors in the dichroic mirror array smaller than the effective diameter of a single condenser lens" can be expressed as D > w.

[0068] In this specification, the distances h and x strictly mean the optical path lengths. That is, when light is bent, the optical path length becomes the distance along the bend, and the optical path length changes according to the refractive index of the medium through which the light passes. However, as shown in FIG. 14 (described later), in this specification, since both the bending of light and the passage of light through a medium other than air are relatively small percentages, the distances h and x can be approximated by the physical distances, that is, The medium of the optical path the shortest distances without considering the refractive index.

[0069] The above optics device (this optics device), while suppressing a decrease in the utilization efficiency of light from the measurement region of a two-dimensionally distributed sample, enables the m-divided m-color images of the measurement region to be stored without overlapping each other Image Sensor inside, and enables spectral imaging by the high-sensitivity snapshot method in the measurement region.

[0070] The light from a point near the optical axis in the measurement region of a two-dimensionally distributed sample is condensed by the condenser lens, expanded to the effective diameter D, and then Image Sensor constricted as it approaches Image Sensor and forms an image at a point above. Therefore, when the dichroic mirror array is Image Sensor placed closer, the above light is constricted at the position of the aperture of the dichroic mirror array, and since the constricted light is located near the center of the aperture, most of the above light can pass through the aperture.

[0071] Also, the light from a point away from the optical axis in the measurement region of a two-dimensionally distributed sample is similarly condensed by the condenser lens, expanded to the effective diameter D, and then Image Sensor constricted as it approaches , which is focused on one point on the image sensor. but the constricted light is open Mouth Because it is located far away from the Light is emitted Depending on the distance from the optical axis of a point, the percentage of the above light that can pass through the aperture decreases. Image Sensor The measurement area of ​​the sample imaged by the optics is limited to the vicinity of the optical axis. Therefore, by making the arrangement interval of the m dichroic mirrors in the Y-axis direction larger than the image size of this measurement area, it is possible to prevent the m divided images of this measurement area from overlapping with each other. Image Sensor This makes it possible to measure each of them simultaneously, with high sensitivity, and independently.

[0072] Books optics The device is characterized by being small, simple, and low-cost compared to conventional spectral imaging devices, including those described in Patent Document 1. Furthermore, it is easy to increase the number of divisions m and the number of colors m to 5 or more. For example, optics If the dichroic mirror array shown in FIG. 29 of Patent Document 3 is used in the device, nine colors (m=9) can be detected.

[0073] Below, book optics The configuration of the device is shown in FIG. 9 of Patent Document 1. optics Compare with the device configuration.

[0074] Conventional optics In the device, the measurement area of ​​the sample distributed two-dimensionally is imaged on the first aperture by the first condenser lens and the first imaging lens, and then imaged on the first aperture by the second condenser lens and the second imaging lens. Image Sensor In addition, multiple dichroic mirrors are placed between the second focusing lens and the second imaging lens.

[0075] In response to this optics In the device, the measurement area of ​​the sample distributed two-dimensionally is focused only by the first focusing lens. Image Sensor The primary imaging is performed on the surface of the object. In addition, multiple dichroic mirrors are used as the first focusing lens. Image Sensor It is placed in the middle of the book. optics Equipment Image Sensor The position of optics This corresponds to the position of the first aperture 20 of the device. optics The size of the device is optics The size of the device can be significantly reduced. The optical device The size of each dichroic mirror can be significantly reduced. The optical device The number of parts can be significantly reduced.

[0076] Below, book optics The configuration of the device is shown in FIG. 7 and FIG. 15 of Patent Document 2. Conventional Optics Compare with the device configuration.

[0077] Patent Document 2 optics In the device, the light emitting point array is used as multiple samples, and the light from the multiple light emitting points is focused by multiple focusing lenses. Image Sensor The dichroic mirror array is used as a condenser lens. Image Sensor However, in order to shorten the maximum optical path length, optics In order to reduce the size of the device, the aperture of the dichroic mirror array is Image Sensor In order to efficiently cause the light beams collected by each collecting lens to enter the dichroic mirror array, the aperture width in the direction in which the multiple dichroic mirrors are arranged is made equal to or larger than the effective diameter of each collecting lens.

[0078] In response to this optics The device focuses the measurement area of ​​the sample distributed two-dimensionally with a single condenser lens. Image Sensor The dichroic mirror array is used as a condenser lens. Image Sensor However, in order to efficiently direct the light beam collected by the condenser lens to the dichroic mirror array, the aperture of the dichroic mirror array is made larger than that of a single condenser lens. Image Sensor In addition, multiple divided images are arranged close to each other. Image SensorIn order to prevent overlapping on the surface, the aperture width in the direction in which the multiple dichroic mirrors are arranged is made smaller than the effective diameter of a single condenser lens. optics The apparatus and the apparatus shown in FIG. 7 and FIG. 15 of Patent Document 2 Conventional Optics The devices have different purposes and are fundamentally different in configuration.

[0079] [Formulation] The schematic diagrams of Figures 1 to 10 and 12 are used to deepen understanding of the above-mentioned [Problems to be Solved by the Invention] and [Summary], and to provide an example of the present invention. optics Formulate the device configuration.

[0080] Figure 1 shows the imaging of the measurement area of ​​a two-dimensionally distributed sample. optics A schematic diagram of the device. The center of the measurement area 1 of the sample distributed two-dimensionally is located on the optical axis 4 of the condenser lens 2. Image Sensor The centers of the three lenses 3 are positioned on either side of the focusing lens 2.

[0081] There are three light-emitting regions 5, 6, and 7 on the measurement area 1 of the sample, and they are indicated by △, ○, and □, respectively. The light-emitting region 6 is on the optical axis 4, and the light-emitting regions 5, 6, and 7 are arranged at equal intervals. The focusing lens 2 focuses the light emitted from the light-emitting regions 5, 6, and 7, respectively, Image Sensor Light emitting area images 8, 9, and 10 are formed on the light emitting area 3, and are indicated by △, ○, and □, respectively. The light emitting area image 9 is on the optical axis 4, and the light emitting area images 8, 9, and 10 are arranged at equal intervals. Here, a magnifying optical system that magnifies the light emitting area image of the light emitting area is shown, but a 1:1 optical system or a reduction optical system may also be used.

[0082] Furthermore, the left contour 11 and the right contour 12 of the light beam 11-12 which is emitted from the light-emitting region 5 and forms the light-emitting region image 8 are shown by dashed lines. The left contour 13 and the right contour 14 of the light beam 13-14 which is emitted from the light-emitting region 6 and forms the light-emitting region image 9 are shown by solid lines. The left contour 15 and the right contour 16 of the light beam 15-16 which is emitted from the light-emitting region 7 and forms the light-emitting region image 10 are shown by solid lines. point Shown by lines.

[0083] FIG. 2 shows the condenser lens 2 and the Image Sensor The aperture 17 and the aperture 18 are located in the center between the three. optics A schematic diagram of the device. The plane formed by the diaphragm 17 and the aperture 18 is perpendicular to the optical axis 4, and the center of the aperture 18 is aligned with the optical axis 4. At this time, a part of the light beams 11-12, 13-14, and 15-16 is blocked by the diaphragm 17, and the rest passes through the aperture 18. Image Sensor As a result, the luminous region images 8, 9, and 10 become weak luminous region images 19, 20, and 21, respectively. To show this change diagrammatically, the outline of each luminous region image has been changed from a solid line to a dashed line.

[0084] FIG. 3 shows the structure of the opening 18 in FIG. Image Sensor 3 18 openings facing the A dichroic mirror A is placed on the side of the optics This is a schematic diagram of the device. The incident surface of the dichroic mirror A is inclined at 45° with respect to the optical axis 4, and the center of the dichroic mirror A is aligned with the optical axis 4. The size of the dichroic mirror A is set so that the entire light beams 11-12, 13-14, and 15-16 that have passed through the opening 18 are just incident on it. At this time, the light beams 11-12, 13-14, and 15-16 that have passed through the dichroic mirror A are Part of but Image Sensor 3, the weak light emission area images 19, 20, and 21 become weak A light emission area images 19A, 20A, and 21A, each of which has components in the transmission wavelength band of the dichroic mirror A. To show this change diagrammatically, the pattern of each light emission area image is changed from white to dots.

[0085] Figure 4 shows the dichroic mirror A in Figure 3. left Dichroic mirror B is placed at optics This is a schematic diagram of the device. The incident surface of dichroic mirror B is parallel to the incident surface of dichroic mirror A. The size of dichroic mirror B is set so that the entire light beams 11-12, 13-14, and 15-16 reflected by dichroic mirror A are incident on dichroic mirror B. At this time, the light beams 11-12, 13-14, and 15-16 transmitted through dichroic mirror A are incident on dichroic mirror B. Part of In addition to the above, light beams 11-12, 13-14, and 15-16 are reflected by dichroic mirror A and dichroic mirror B. Part of but Image Sensor 3, the weak light emission region images 19, 20, 21 are divided into two images, weak A light emission region images 19A, 20A, 21A, each of which has a component in the transmission wavelength band of dichroic mirror A, and weak B light emission region images 19B, 20B, 21B, each of which has a component in the wavelength band obtained by multiplying the reflection wavelength band of dichroic mirror A by the reflection wavelength band of dichroic mirror B. The pattern of the weak B light emission region image is indicated by diagonal lines.

[0086] Note that a wavelength band obtained by "multiplying" two or more wavelength bands means, for example, a wavelength band represented by a spectrum obtained by multiplying the spectra representing each of the two or more wavelength bands. The same applies below.

[0087] The distance between the two divided images, for example, the distance between the weak A light emission area image 19A and the weak B light emission area image 19B, is equal to the distance between the dichroic mirror A and the dichroic mirror B. Compared with the mutual distance between the weak light emission area images 19, 20, and 21, the distance between the two divided images is smaller, so the two divided images are measured with some overlapping each other. Note that in this specification, the distance between the two images refers to the distance between corresponding points in each image. Get away It may mean.

[0088] Figure 5 shows the dichroic mirror in Figure 4. -B of left Dichroic mirror C is placed at optics This is a schematic diagram of the device. The incident surface of dichroic mirror C is parallel to the incident surfaces of dichroic mirrors A and B. The size of dichroic mirror C is set so that the entire light beams 11-12, 13-14, and 15-16 that are reflected by dichroic mirror A and transmitted through dichroic mirror B are incident on dichroic mirror C. At this time, the light beams 11-12, 13-14, and 15-16 that are transmitted through dichroic mirror A are incident on dichroic mirror C. Part of , and light beams 11-12, 13-14, and 15-16 reflected by dichroic mirror A and dichroic mirror B. Part of In addition, light beams 11-12, 13-14, and 15-16 are reflected by dichroic mirror A, transmitted by dichroic mirror B, and reflected by dichroic mirror C. Part of but Image Sensor 3, the weak light emission area images 19, 20, 21 are divided into three parts: weak A light emission area images 19A, 20A, 21A having as their component the transmission wavelength band of dichroic mirror A; weak B light emission area images 19B, 20B, 21B having as their component the wavelength band obtained by multiplying the reflection wavelength band of dichroic mirror A with the reflection wavelength band of dichroic mirror B; and weak C light emission area images 19C, 20C, 21C having as their component the wavelength band obtained by multiplying the reflection wavelength band of dichroic mirror A with the transmission wavelength band of dichroic mirror B with the reflection wavelength band of dichroic mirror C. The pattern of the weak C light emission area images is indicated by a check.

[0089] The mutual distances between the three divided images, for example, the distance between the weak A light emission region image 19A and the weak B light emission region image 19B, or the distance between the weak B light emission region image 19B and the weak C light emission region image 19C, are equal to the distance between dichroic mirror A and dichroic mirror B, or the distance between dichroic mirror B and dichroic mirror C. Compared with the mutual distances between the weak light emission region images 19, 20, and 21, the mutual distances between the three divided images are smaller, so the three divided images are measured overlapping each other.

[0090] In Figures 4 and 5, spectral imaging is performed to obtain split images of multiple different wavelength bands, i.e., multiple different colors, but there are two problems as follows. One is that, as is clear from a comparison between Figures 1 and 2, only a portion of the light beams 11-12, 13-14, and 15-16 focused by the focusing lens 2 is measured, resulting in weak signal strength and low sensitivity. The other is that, as is clear from Figures 4 and 5, multiple split images of different colors are measured while overlapping with each other, so each split image cannot be measured independently. Both problems are fatal in performing spectral imaging.

[0091] Figure 6 shows ,figure The positions of the aperture 17 and the aperture 18 in Image Sensor3, and placed parallel to the optical axis 4. optics 2 and 6 are schematic diagrams of the device. That is, the width of the aperture 18 in FIG. 2 is the same as that in FIG. 6. At this time, most of the light beams 13-14 pass through the aperture 18. Image Sensor While the light beams 11-12 and 15-16 reach the aperture 17, all of them are blocked by the aperture 17. Image Sensor 1, while the light emitting area image 9 is measured in the same manner as in FIG.

[0092] FIG. 7 shows that the opening 18 in FIG. 6 is followed by a Image Sensor 3 18 openings facing the A dichroic mirror A is placed on the side of the optics A schematic diagram of the device. At this time, the light beam 13-14 transmitted through the dichroic mirror A is Part of Only Image Sensor 3, the light emitting area image 9 becomes a light emitting area image 9A having components in the transmission wavelength band of the dichroic mirror A.

[0093] Figure 8 shows the same results as in Figure 4 for the dichroic mirror A in Figure 7. left Dichroic mirror B is placed at optics A schematic diagram of the device. Light beam 13-14 transmitted through dichroic mirror A. Part of In addition to the above, the light beam 13-14 is reflected by dichroic mirror A and then by dichroic mirror B. Part of but Image Sensor 3, the light-emitting area image 9 is divided into two images: an A-light-emitting area image 9A, whose component is the transmitted wavelength band of dichroic mirror A, and a B-light-emitting area image 9B, whose component is the wavelength band obtained by multiplying the reflected wavelength band of dichroic mirror A and the reflected wavelength band of dichroic mirror B.

[0094] The distance between these two divided images is equal to the distance between dichroic mirror A and dichroic mirror B. Since the distance between these two divided images is greater than the size of the light-emitting area image 9, that is, the size of the A-light-emitting area image 9A and the B-light-emitting area image 9B, these two divided images are measured without overlapping with each other.

[0095] Figure 9 shows the same as Figure 5 in Figure 8, except that the dichroic mirror -B of left Dichroic mirror C is placed at optics A schematic diagram of the device. Light beam 13-14 transmitted through dichroic mirror A. Part of , and the light beam 13-14 reflected by dichroic mirror A and then by dichroic mirror B Part of In addition, the light beam 13-14 is reflected by dichroic mirror A, transmitted by dichroic mirror B, and reflected by dichroic mirror C. Part of but Image Sensor 3, the light-emitting area image 9 is divided into three parts: an A-light-emitting area image 9A whose component is the transmitted wavelength band of dichroic mirror A; a B-light-emitting area image 9B whose component is the wavelength band obtained by multiplying the reflected wavelength band of dichroic mirror A with the reflected wavelength band of dichroic mirror B; and a C-light-emitting area image 9C whose component is the wavelength band obtained by multiplying the reflected wavelength band of dichroic mirror A with the transmitted wavelength band of dichroic mirror B with the reflected wavelength band of dichroic mirror C.

[0096] The mutual distances between these three divided images are equal to the distances between dichroic mirror A and dichroic mirror B, and between dichroic mirror B and dichroic mirror C. Since the mutual distances between these three divided images are greater than the size of the light-emitting area image 9, that is, the size of the A light-emitting area image 9A, the B light-emitting area image 9B, and the C light-emitting area image 9C, these three divided images are measured without overlapping with each other.

[0097] In Figures 8 and 9, spectral imaging is performed to obtain split images of multiple different wavelength bands, i.e., multiple different colors. Unlike the cases of Figures 4 and 5, most of the light beams 13-14 focused by the focusing lens 2 are measured, so the signal strength is strong and the sensitivity is high. Also, as is clear from Figures 8 and 9, multiple different color split images are measured without overlapping with each other, so each split image can be measured independently. Both sensitivity and independent measurement of split images are basic performance of spectral imaging, and achieving high levels of these is suitable and advantageous for spectral imaging.

[0098] Figure 10 is a schematic diagram for formulating the conditions suitable for spectral imaging. In Figure 10, a right-handed XYZ orthogonal coordinate system is defined. . collection The principal point of the optical lens is the origin, the optical axis 4 is the X-axis, the direction perpendicular to the optical axis 4 and parallel to the paper surface is the Y-axis, and the direction perpendicular to the paper surface is the Z-axis. The positive directions of the X-axis are upward on the paper surface, the Y-axis are rightward on the paper surface, and the Z-axis are toward the back of the paper surface.

[0099] The effective diameter D of the condenser lens 2 is expressed as D (not shown), the focal length as f (not shown), the distance between the condenser lens 2 and the measurement area 1 as g (the absolute value of the X coordinate of the measurement area 1 as g), and the distance between the condenser lens 2 and the measurement area 1 as g (the absolute value of the X coordinate of the measurement area 1 as g). Image Sensor The distance between 3 and h( Image Sensor The X-coordinate of condenser lens 3 is h), the distance between condenser lens 2 and aperture 17 and aperture 18 is x (the X-coordinate of aperture 17 and aperture 18 is x), the width of aperture 18 in the Y-axis direction is w, and the width of aperture 18 in the Z-axis direction is v (not shown in FIG. 10).

[0100] 10 omits the light-emitting regions 5 and 6, their emitted light beams, and their light-emitting region images in Fig. 2, and focuses on the light-emitting region 7, its emitted light beams 15-16, and its weak light-emitting region image 21. The size of the light-emitting region 7 in the Y-axis direction is d, the Y coordinate of the light-emitting region 7 (the distance between the light-emitting region 7 and the optical axis 4) is y, the size of the weak light-emitting region image 21 in the Y-axis direction is d', the absolute value of the Y coordinate of the weak light-emitting region image 21 is y' (the distance between the weak light-emitting region image 21 and the optical axis 4), and the image magnification is m.

[0101] Furthermore, when multiple dichroic mirrors (not shown in Figure 10) are arranged, multiple divided images are obtained, and the distance between any two adjacent divided images, i.e., the division pitch, is defined as p. Basically, p is considered to be approximately constant regardless of the divided images. Furthermore, if the distance between two adjacent divided images is not constant, the average value or the most frequent value of the distance between the two adjacent divided images is defined as the division pitch p. Alternatively, the minimum value of the distance between the two adjacent divided images is defined as the division pitch p. Meanwhile, the distance between two adjacent divided images is often equal to the distance between the two dichroic mirrors through which the light beams generating each divided image are ultimately transmitted or reflected, but this may not necessarily be equal depending on the structure.

[0102] The following can be derived from the geometric optics in Figure 10.

number

[0103] As is clear from a comparison of FIG. 5 and FIG. 9, the positions of the diaphragm 17 and the aperture 18 are the same as those of the condenser lens 2. Image Sensor Between the three, more central, Image Sensor A position close to 3 is advantageous for spectral imaging. This condition can be expressed by the following equation.

number

number

[0104] Figures 11(a) and (b) are respectively Figures 7(a) and (b) of Patent Document 2, with the notation modified to conform to this specification. For example, the four light-emitting points correspond to the four samples and correspond to light-emitting region 6 in Figure 9, so light-emitting region 6 is represented as a light-emitting point. In addition, the diaphragm and aperture, which were omitted in Figure 7 of Patent Document 2, are represented as diaphragm 17 and aperture 18.

[0105] The light emitted from the four light-emitting regions 6 (light-emitting point array) is focused by four focusing lenses 2 (focusing lens array) with an effective diameter D, passes through one long-pass filter 38, and is divided into four colors by four types of dichroic mirrors M1, M2, M3, and M4 (dichroic mirror array). Image Sensor 3. Connect the four color quadrant images J1, J2, J3, and J4 at different positions on the screen.

[0106] The focal length of the condenser lens 2 is f (not shown), the distance between the condenser lens 2 and the light emitting area 6 is g, and the distance between the condenser lens 2 and the light emitting area 6 is Image Sensor The distance in the X-axis direction of 3 is h, the distance in the X-axis direction of condenser lens 2 and aperture 17 and aperture 18 is x, the width of aperture 18 in the direction in which four types of dichroic mirrors M1, M2, M3, and M4 are arranged is w, and the width of aperture 18 in the direction in which four condenser lenses 2 are arranged is v. 4 pieces The arrangement interval of the four divided images, which corresponds to the arrangement interval of the dichroic mirrors M1, M2, M3, and M4, is defined as p.

[0107] As described in the [Background Art] section, in order to detect the light emitted from each light emitting point independently and with high sensitivity, a light emitting point array, a condenser lens array, a dichroic mirror array, Image Sensor It is important to place the multi-color detectors close to each other to reduce the size of the multi-color detector that they are made of, and to ensure that the aperture width of the dichroic mirror array is large so that each condenser lens can measure most of the light condensed by it. Therefore, as is clear from Figure 11,

number

[0108] [Example 1] FIG. 12 is a schematic diagram for formulating conditions more suitable for spectral imaging. In FIG. 10, the X coordinates of the aperture 17 and the aperture 18 are changed, and the case of the aperture 17a and the aperture 18a and the case of the aperture 17b and the aperture 18b are displayed superimposed.

[0109] The aperture 17a and the aperture 18a indicate the aperture and the aperture when the right contour 16 of the light beam 15 - 16 from the light emitting region 7 passes through the right end of the aperture 18a. If the X coordinate of the aperture 17a and the aperture 18a is xt, [Number] it is. The aperture 17 and the aperture 18 show an example when the X coordinate is x < xt, and the aperture 17b and the aperture 18b show an example when the X coordinate is x > xt.

[0110] As shown in FIG. 12, if the width in the Y - axis direction of the light beam 15 - 16 at an arbitrary x of the X coordinates of the aperture 17 and the aperture 18 is Q, [Number] it is. Also, as shown in FIG. 12, if the width in the Y - axis direction of the portion of the light beam 15 - 16 passing through the aperture 18 at an arbitrary x where the X coordinates of the aperture 17 and the aperture 18 are x ≧ xt is R, [Number] it is. If the ratio of the light beam 15 - 16 passing through the aperture 18 is defined as the detection efficiency E, as is clear from FIG. 12, when the X coordinates of the aperture 17 and the aperture 18 are x < xt, [Number] When the X coordinate of the aperture 17 and the aperture 18 is x ≥ xt,

number

[0111] When the size of the light-emitting region 7 in the Y-axis direction is sufficiently small, such as when the light-emitting region 7 is a light-emitting point, it can be approximated as d = 0. In this case, (Equation 9), (Equation 10), and (Equation 11) can be rewritten as follows.

number

number

number

number

number

[0112] Figure 13 is a schematic diagram of a snapshot-type spectral imaging device constructed by combining a laser-excited epifluorescence microscope with a dichroic mirror array. A right-handed XYZ orthogonal coordinate system is defined as shown in the figure. Note that the coordinate system symbols have been altered from their exact locations in Figure 13 for clarity. 10, the origin is placed at the principal point of the condenser lens 2. The optical axis 4 of the condenser lens 2 is the X-axis.

[0113] Measurement area 1 of a sample distributed two-dimensionally, and measurement area 1 is imaged Image Sensor 3 are arranged perpendicular to the X-axis. The condenser lens 2 is an objective lens of a fluorescence microscope, and is actually a combination of multiple single lenses, but in this specification it is represented as a single lens equivalent to the combination lens.

[0114] A laser beam 45 emitted from a laser light source 44 travels in the negative direction of the Y axis and is incident on a dichroic mirror 46 whose incident surface is tilted 45° with respect to the X and Y axes. The reflected light travels in the negative direction of the X axis and is collected by a collecting lens 2, and is irradiated onto a measurement area 1 of a sample distributed two-dimensionally. The dichroic mirror 46 reflects the laser beam incident at an incident angle of 45°. 45 A laser beam that reflects light of wavelengths of 1000 nm or shorter and is incident at an angle of 45° 45 light with a wavelength longer than that of a laser beam 45 The fluorescent light emitted by excitation at the .lambda.

[0115] The laser beam 45 is reflected or scattered in the measurement area 1, and is focused by the focusing lens 2, enters the dichroic mirror 46 along the positive direction of the X-axis, and is reflected in the positive direction of the Y-axis. Fluorescence emitted from an arbitrary point (light-emitting point) on the measurement area 1 is focused by the focusing lens 2 to become a light beam C0, which travels in the positive direction of the X-axis, passes through the dichroic mirror 46, and Image Sensor 3. On top (Fluorescence image) The size of the above light emitting point in the Y-axis direction is d=0 mm, and the Y coordinate is y. In this way, a fluorescent image of the measurement area 1 is formed. Image Sensor 3 is formed on top.

[0116] However, in Figure 13, in addition to the above, Image Sensor In the first paragraph of 3 ( Image Sensor 3 X-axis negative side In addition, a diaphragm 17, an aperture 18, and a dichroic mirror array 43 consisting of four types of dichroic mirrors are arranged. That is, a two-dimensionally distributed sample, a single condenser lens 2, and a dichroic mirror array 43 in which multiple dichroic mirrors are arranged, Image Sensor 3 are arranged in this order along the optical axis 4 of the condenser lens 2. As a result, a four-part fluorescent image of the measurement area 1 is Image Sensor 3 is formed on top.

[0117] In other words, in a right-handed XYZ orthogonal coordinate system, a sample is distributed two-dimensionally parallel to the YZ plane, a single condenser lens 2 whose optical axis 4 coincides with the X axis, a dichroic mirror array 43 in which m dichroic mirrors are arranged in parallel to each other in the Y-axis direction, where m is an integer equal to or greater than 2, and a Image Sensor 3 are arranged in the above order along the positive direction of the X-axis.

[0118] In FIG. 14, the dichroic mirror array 43 and Image SensorA detailed view of the periphery of 3 has been added, and the same notation as in Fig. 10 has been added. The detailed view 14(a) in the upper right is a view observed from the negative direction of the Z axis, and the detailed view 14(b) below it is a view observed from the negative direction of the Y axis. In Fig. 14, the laser light source 44, the laser beam 45, and the dichroic mirror 46 have been omitted.

[0119] The focal length of the condenser lens 2 is f (not shown), the distance between the condenser lens 2 and the measurement area 1 is g, and the distance between the condenser lens 2 and the measurement area 1 is Image Sensor The distance between the focusing lens 2 and the aperture 17 is defined as h, and the distance between the focusing lens 2 and the aperture 17 and the aperture 18 is defined as x. In this embodiment, a focusing lens 2 with f=9.52 mm and D=10 mm is used, and h=200 mm is set based on the design of the focusing lens 2. In this case, g=1 mm from (Equation 1), and m=20 from (Equation 2).

[0120] Image Sensor The size of aperture 18 is 10 mm (width in the Y-axis direction) × 10 mm (width in the Z-axis direction). The width of aperture 18 in the Y-axis direction is w, and the width of aperture 18 in the Z-axis direction is v. Dichroic mirror array 43 is composed of four types of dichroic mirrors M1, M2, M3, and M4.

[0121] The light beam C0 passes through the aperture 18 and is divided into four by the dichroic mirror array 43, becoming four divided light beams C1, C2, C3, and C4. Image Sensor The four dichroic mirrors M1, M2, M3, and M4 are arranged at intervals p in the Y-axis direction, and the four split beams C1, C2, C3, and C4 are 4-part image The distance between them is also p.

[0122] From Figure 14, optics The device clearly satisfies (Equation 5). That is, the dichroic mirror array 43 is more efficient than the condenser lens 2. Image Sensor 3. Furthermore, from Figure 14, optics The device clearly satisfies (Equation 6). In addition, the direction in which the multiple dichroic mirrors M1, M2, M3, and M4 are arranged is perpendicular to the optical axis 4.

[0123] In the example of FIG. 14, the dichroic mirror array 43 Image Sensor There is no lens between 3. optics The configuration of the device is simple.

[0124] FIG. 15 shows an improved and detailed view of the dichroic mirror array 43 of FIG. Hereinafter, this improved type will also be referred to as the dichroic mirror array 43. As in FIG. 14, a right-handed XYZ orthogonal coordinate system is defined in the figure. Note that, as with Figures 13 and 14, the coordinate system symbols have been altered from their exact locations in Figure 15 for clarity. The long-pass filter 47 is located immediately after the aperture 18 ( Opening 18 X-axis positive side), and then the next stage ( Long pass filter 47 A dichroic mirror M1 is arranged on the right side (positive direction of the X-axis) of the optical axis 4. Starting from the dichroic mirror M1, dichroic mirrors M2, M3, and M4 are arranged at equal intervals on the right side (positive direction of the Y-axis). The entrance and exit surfaces of the dichroic mirrors M1, M2, M3, and M4 are arranged perpendicular to the straight line Y=-X on the XY plane. Also, following FIG. 15 of Patent Document 2, the aperture width is increased by shifting the four dichroic mirrors M1, M2, M3, and M4 in a stepped manner in the X-axis direction. For this reason, the direction in which the dichroic mirrors M1, M2, M3, and M4 are arranged is not strictly perpendicular to the optical axis 4 but is approximately perpendicular, but such a direction is also included in the perpendicular direction in this specification.

[0125] In FIG. 14, the contours of the light beam C0 and the divided light beams C1 to C4 are shown, whereas in FIG. 15, the optical axes of the light beam C0 and the divided light beams C1 to C4 are shown. and a virtual parallel light beam 48 Shown Be Each parallel light beam 48 is made up of 11 light beam elements arranged parallel to each other and at equal intervals. composition The width of the entire parallel light beam 48 is set to coincide with the aperture width w of the dichroic mirror array 43.

[0126] The light beam C0 passes through the opening 18 along the optical axis 4 as in FIG. 14, and is transmitted through the long-pass filter 47. The reflected or scattered light of the laser beam 45 is blocked by the dichroic mirror 46 as in FIG. 13 (it is reflected without passing through the dichroic mirror 46), but is further blocked by the long-pass filter 47. The light beam C0 that has transmitted through the long-pass filter 47 enters the dichroic mirror M1, and is split into reflected light traveling in the positive direction of the Y axis, and transmitted light traveling in the positive direction of the X axis. This transmitted light is the split light beam C1, Image Sensor 3 is incident perpendicularly to Imaged The light beam reflected by the dichroic mirror M1 enters the dichroic mirror M2 and is split into a transmitted light beam traveling in the positive direction of the Y axis and a reflected light beam traveling in the positive direction of the X axis. This reflected light is a split light beam C2, Image Sensor 3 is incident perpendicularly to Imaged The light beam transmitted through the dichroic mirror M2 enters the dichroic mirror M3 and is split into a transmitted light beam traveling in the positive direction of the Y axis and a reflected light beam traveling in the positive direction of the X axis. This reflected light is the split light beam C3, Image Sensor 3 is incident perpendicularly to Imaged The light beam transmitted through the dichroic mirror M3 enters the dichroic mirror M4 and becomes reflected light traveling in the positive direction of the X-axis. This reflected light is the split light beam C4, Image Sensor 3 is incident perpendicularly to Imaged do.

[0127] In this way, the image of the measurement area on the sample is Image Sensor On the 3, the light is split into multiple images (m=4 images, where m=4 is the number of dichroic mirrors) having different wavelength components and measured.

[0128] The long-pass filter 47 and the dichroic mirrors M1, M2, M3, and M4 are made of quartz glass with a refractive index of 1.46, and the dimensions are width a = 3 mm (parallel to the XY plane and Filter or The dimension parallel to the incidence surface of the dichroic mirror), thickness b = 1 mm (parallel to the XY plane and Filter orThe dichroic mirror has a diameter c = 15 mm (dimension perpendicular to the incident surface of the dichroic mirror) and a depth c = 15 mm (dimension parallel to the Z axis, not shown). The arrangement interval in the Y-axis direction of dichroic mirrors M1, M2, M3, and M4 is 2.5 mm. However, as can be seen from a detailed analysis of Figure 15, the distance between the divided images of C2 and C3, and the distance between the divided images of C3 and C4 are 2.5 mm, but the distance between the divided images of C1 and C2 is slightly smaller at 2.1 mm. In this embodiment, the most frequent value of 2.5 mm is used as the division pitch, and p = 2.5 mm.

[0129] Also, the dichroic mirror array 43 is shifted in a staircase-like manner (step arrangement). That is, the dichroic mirror M2 is shifted 0.7 mm in the negative X-axis direction from the dichroic mirror M1, the dichroic mirror M3 is shifted 0.3 mm in the negative X-axis direction from the dichroic mirror M2, and the dichroic mirror M4 is shifted 0.3 mm in the negative X-axis direction from the dichroic mirror M3. These shift amounts are designed, for example, based on (Formula B) or (Formula D) described below so that the dichroic mirror array 43 functions appropriately.

[0130] With the above configuration, an aperture width w = 1.4 mm is obtained as shown in Fig. 15. The aperture width in the depth direction is v = 15 mm. If the total width of the parallel light beam 48 is made larger than 1.4 mm, at least a part of the parallel light beam 48 will be vignetted inside the dichroic mirror array 43, and the entire parallel light beam 48 will be Image Sensor 3. Incidentally, if the dichroic mirror array 43 is not shifted in a stepped manner, that is, if the above shift is set to 0 mm, the aperture width is significantly reduced to w = 0.03 mm.

[0131] Ensuring a large opening width w is Image Sensor 3 is important for increasing the amount of light received and improving the sensitivity of the measurement. On the other hand, the aperture width w = 1.4 mm is smaller than the effective diameter D = 10 mm of the focusing lens 2, and (Equation 6) is satisfied. Therefore, the basic performance of the spectral imaging can be improved.

[0132] In this way, the aperture 17 The aperture 18 of the dichroic mirror array 43 is provided in Dichroic mirror array 43 Condenser lens 2 side It is preferable that the aperture 18 is located close to the dichroic mirror array 43, and the width of the aperture 18 in the direction in which the multiple dichroic mirrors M1, M2, M3, and M4 are arranged is smaller than the effective diameter of the condenser lens 2. Also, the aperture 18 of the dichroic mirror array 43 provided in the diaphragm 17 is located on the X-axis as follows: Dichroic mirror array 43 Condenser lens 2 side It is located close to the dichroic mirror array 43 and is connected to the condenser lens 2. Image Sensor When the distance in the X-axis direction of 3 is h and the distance in the X-axis direction between the focusing lens and the opening is x, it is preferable that formula 5 is satisfied.

[0133] For the above reasons, it is undesirable for the opening width to be either too small or too large, and it is preferable for it to be within an appropriate range.

[0134] On the other hand, as shown in Figure 15 ,distance Separate (i.e., condenser lens 2 and Image Sensor The distance between the condenser lens 2 and the aperture 17 or The difference between the distance of the aperture 18 and the distance of the aperture 18 is set to hx = 10 mm or 15 mm (hx = 10 mm in Figure 15). In this case, since h = 200 mm, x = 190 mm or 185 mm, and x / h = 95% or 92.5%, respectively. In either case, (Equation 5) is satisfied. Therefore, the basic performance of spectral imaging can be improved.

[0135] Below, a suitable structure of the above dichroic mirror array will be generalized following Patent Document 2.

[0136] In a right-handed XYZ Cartesian coordinate system, m≧2, in a dichroic mirror array in which m dichroic mirrors D1 to Dm are arranged parallel to each other along the positive direction of the Y axis, (1) The incident planes of the dichroic mirrors D1 to Dm are perpendicular to the XY plane. (2) The inclination of the line projected onto the XY plane from the normal to the incident surface of the dichroic mirrors D1 to Dm is negative, and the angle between the normal and the X axis is θ 0 year, (3) Let the refractive index of the substrate of the dichroic mirrors D1 to Dm be n 0 , the average width parallel to the XY plane and perpendicular to the normal to the incident surface is a, and the average width parallel to the XY plane and parallel to the normal to the incident surface is b. (4) When comparing the positions of two adjacent dichroic mirrors Dj and D(j+1) (where 1≦j≦(m-1)) on the XY plane, the Y coordinate of the dichroic mirror D(j+1) is larger, and the X coordinate of the dichroic mirror Dj is larger. (5) When the average arrangement interval of two adjacent dichroic mirrors Dj and D(j+1) (where 2≦j≦(m-1)) in the Y-axis direction is Δy and the average arrangement interval in the X-axis direction is Δx, Dichroic Mirror Array of The aperture width in the Y-axis direction is enlarged, and the dichroic mirror array is I To reduce the optical path length, θ 0 ,n 0 , a, b, Δy, and Δx satisfy a specified relationship.

[0137] It should be noted that dichroic mirror D1 is on the X-axis, and the m dichroic mirrors are named D1, D2, ..., Dm in order from the negative direction to the positive direction of the Y-axis.

[0138] in particular,

number

number

number

number

[0139] The four-division dichroic mirror array shown in FIG. 15 of course satisfies (Equation A) to (Equation D). 0 In many cases, a setting of θ = 45° is most effective. 0 If ≠ 45°, Image Sensor is not parallel to the YZ plane, for example, θ 0 or θ 0 In some cases, tilting it by -45° is sufficient.

[0140] The graph in FIG. 16 shows the results of calculating the change in E when x is changed in the range of 0 to 200 mm, using (Equation 17) and (Equation 18) and y as a parameter. On the vertical axis of the graph Although E is shown in the range of 0.0 to 1.0, in this specification, this is interpreted as 0% to 100%. E=100% is the detection efficiency obtained when there is absolutely no light loss (blockage) due to the diaphragm 17 and the aperture 18, E=50% is half the detection efficiency, and E=0% means no detection at all. The conditions were the same as above except for x. That is, D=10 mm, w=1.4 mm, p=2.5 mm, h=200 mm, d=0 mm, and m=20. These conditions are also shown below the graph in Figure 16.

[0141] First, when we look at y=0 mm, E rises with x from E=14% at x=0 mm, and then increases to x=xt0 At y=173 mm, E reaches 100% and is maintained at 100% thereafter. Next, when we look at y=0.04 mm, E increases with x from 14% at x=0 mm, as in the case of y=0 mm, but at x=xt 0 At x=148 mm, E=54%, and then E starts to decrease along with x, and at x=197 mm, E=0%, x>197 mm In general, when y is increased, xt 0 As a result, the x at which E changes from increasing to decreasing decreases, and E=0% x The minimum value of also decreases.

[0142] FIG. 17 is a graph in which the horizontal axis and parameters of FIG. 16 are interchanged, that is, it shows the results of calculating the change in E when y is changed in the range of 0 to 0.14 mm with x as the parameter.

[0143] As a first example, when x is fixed at 190 mm (x / h = 95%), E = 100% at y = 0 mm and 0.02 mm, E = 38% at y = 0.04 mm, and E = 0% at y ≧ 0.06 mm. Using (Equation 20), the Y coordinate of the light-emitting point where E = 0% is The minimum value of To get a detailed look at y m = 0.05 mm. In other words, since the optical system is symmetrical with respect to the optical axis 4, light-emitting points with y ≦ ±0.05 mm are measured, and light-emitting points with y > ±0.05 mm are not measured. In other words, the range of the sample that is y ≦ ±0.05 mm and has a width of 0.1 mm in the Y-axis direction is imaged as the measurement area 1, but the range of the sample that is y > ±0.05 mm is no longer the measurement area 1 and is not imaged. In general, the width in the Y-axis direction of the measurement area 1 of each divided image is 2 × y m It is.

[0144] In this specification, -0.05 mm≦y≦0.05 mm will be expressed as y≦±0.05 mm, and y<-0.05 mm or y>0.05 mm will be expressed as y>±0.05 mm.

[0145] As a second example, when x is fixed at 185 mm (x / h = 93%), E = 100% at y = 0 mm, E = 94% at y = 0.02 mm, E = 45% at y = 0.04 mm, and E = 0% at y ≥ 0.06 mm. Using (Equation 20), the Y coordinate of the light-emitting point where E = 0% is The minimum value of To get a detailed look at y m = 0.06 mm. In other words, light-emitting points with y ≦ ±0.06 mm are measured, and light-emitting points with y > ±0.06 mm are not measured. In other words, the range of the sample in the range of y ≦ ±0.06 mm and the range of 0.12 mm in the Y-axis direction becomes measurement area 1 and is imaged, but the range of the sample in the range of y > ±0.06 mm is no longer measurement area 1 and is not imaged.

[0146] As a third example, when x is fixed at 180 mm (x / h=90%), E=100% at y=0 mm, E=84% at y=0.02 mm, E=48% at y=0.04 mm, E=12% at y=0.06 mm, and E=0% at y≧0.08 mm. Using (Equation 20), the Y coordinate of the light-emitting point where E=0% is The minimum value of To get a detailed look at y m = 0.07 mm. In other words, light-emitting points with y ≦ ±0.07 mm are measured, and light-emitting points with y > ±0.07 mm are not measured. In other words, the range of the sample in the y ≦ ±0.07 mm range with a width of 0.14 mm in the Y-axis direction becomes measurement area 1 and is imaged, but the range of the sample in the y > ±0.07 mm range is no longer measurement area 1 and is not imaged.

[0147] As a fourth example, when x is fixed at 155 mm (x / h=78%), E=62% at y=0 mm and 0.02 mm, E=54% at y=0.04 mm, E=40% at y=0.06 mm, E=26% at y=0.08 mm, E=12% at y=0.1 mm, and E=0% at y≧0.12 mm. Using (Equation 20), the Y coordinate of the light-emitting point where E=0% is The minimum value of To get a detailed look at y m= 0.12 mm. In other words, light-emitting points with y ≦ ±0.12 mm are measured, and light-emitting points with y > ±0.12 mm are not measured. In other words, the range of the sample in the y ≦ ±0.12 mm range with a width of 0.24 mm in the Y-axis direction becomes measurement area 1 and is imaged, but the range of the sample in the y > ±0.12 mm range is no longer measurement area 1 and is not imaged.

[0148] As described above, as x / h increases (as x / h approaches 100%), the area of ​​the measurement area 1 imaged width The area of ​​the light emitted from each light source is limited, and the signal strength and contrast of the measured image are increased. This is an ideal condition for simultaneously measuring images divided into multiple different colors. In other words, the signal strength of each light-emitting point is strong, the sensitivity is high, and multiple divided images of different colors are measured without overlapping with each other, so each divided image can be measured independently.

[0149] Based on the above considerations, we clarify more suitable conditions than (Equation 5) in order to improve the basic performance of spectral imaging.

[0150] The first condition is that there is at least a part of the divided images that do not overlap each other. The width of each divided image in the Y-axis direction is 2 × y m ×m, while the spacing between the divided images is p, so this condition m ≦p / m, and using (Equation 20),

number

[0151] The second condition is that the detection efficiency of at least the center of each of the multiple divided images is maintained at E = 100%. This condition is expressed as E 0 ≧1,

number

[0152] The third condition is that there are no overlapping parts of the divided images. m ≦p / m / 2, and using (Equation 20),

number

[0153] Under the above conditions, i.e., D=10 mm, w=1.4 mm, p=2.5 mm, and h=200 mm, the first condition is 155 mm≦x≦200 mm, i.e., 78%≦x / h≦100%, the second condition is 175 mm≦x≦200 mm, i.e., 88%≦x / h≦100%, and the third condition is 185 mm≦x≦200 mm, i.e., 93%≦x / h≦100%. Therefore, the above first and second examples satisfy the first to third conditions, the third example satisfies the first and second conditions, and the fourth example satisfies only the first condition.

[0154] [Example 2] Under the conditions shown in Example 1, laser-excited four-color fluorescence spectrum imaging of a sample is performed using the configuration shown in FIGS.

[0155] 18 shows a two-dimensionally distributed area of ​​0.5 mm×0.5 mm on sample surface 49. As shown in the figure, a right-handed XYZ Cartesian coordinate system common to FIGS. 13 to 15 is defined. Note that the coordinate system symbols have been altered from their exact locations in Figure 18 for clarity. The horizontal right direction is the positive Y-axis direction ,Tare The downward direction is the positive direction of the Z axis ,Oku The direction of travel is the positive direction of the X-axis. For convenience, this area is divided into 400 0.025 mm x 0.025 mm sections arranged in a 20 row x 20 column grid, but the boundaries of each section are not illuminated.

[0156] The letters written in each section indicate the local distribution of four types of phosphors, and each letter emits fluorescence when irradiated with a laser beam. Although each letter has no meaning, since a different letter is written in each section, it is possible to identify the section that corresponds to the imaged letter. Each section has two letters, the first of which is an uppercase alphabet and the second is a lowercase alphabet. The first letter changes from the first row to the twentieth row as A, B, ..., T, and the second letter changes from the first column to the twentieth column as a, b, ..., t.

[0157] Each letter in the first row (first letter is A), fifth row (first letter is E), ninth row (first letter is I), thirteenth row (first letter is M), and seventeenth row (first letter is Q) is labeled with the first fluorophore. The emitted fluorescence of the first fluorophore is measured only in the first divided image (image of divided beam C1) of the four divided images.

[0158] Each of the letters in the second line (first letter is B), the sixth line (first letter is F), the tenth line (first letter is J), the fourteenth line (first letter is N), and the eighteenth line (first letter is R) is labeled with a second fluorophore. The emitted fluorescence of the second fluorophore is measured only in the second divided image (image of divided beam C2) of the four divided images.

[0159] Each of the letters in the third row (first letter is C), seventh row (first letter is G), eleventh row (first letter is K), fifteenth row (first letter is O), and nineteenth row (first letter is S) is labeled with a third fluorophore. The emitted fluorescence of the third fluorophore is measured only in the third divided image (image of divided beam C3) of the four divided images.

[0160] Each of the letters in the 4th line (first letter is D), 8th line (first letter is H), 12th line (first letter is L), 16th line (first letter is P), and 20th line (first letter is T) is labeled with a fourth fluorophore. The emitted fluorescence of the fourth fluorophore is measured only in the fourth divided image (image of divided beam C4) among the four divided images.

[0161] In reality, the fluorescence spectrum of each fluorophore is wide, so each emitted fluorescence is measured in multiple divided images (in multiple different wavelength bands). This is called spectral overlap. The fluorescence intensity ratio of the emitted fluorescence of each fluorophore measured in each divided image is calculated in advance, and the measured value is calculated based on that information. ,Fluorescence from multiple fluorophores It is possible to cancel the spectral overlap that exists in multiple divided images. This process is called color conversion, deconvolution, or unmixing. In this embodiment, this process is omitted. S Spectral overlap Cancelled It is assumed that the segmented images are obtained directly.

[0162] In Fig. 19, the range of the measurement area 50 to be imaged on the sample surface 49 in Fig. 18 is shown by a thick dashed line in the second example of the first embodiment, that is, when D = 10 mm, w = 1.4 mm, p = 2.5 mm, h = 200 mm, d = 0 mm, m = 20, and x = 185 mm. These conditions are also shown at the bottom of Fig. 19. The width of the measurement area 50 in the Y-axis direction is, as mentioned above, 2 × y m = 0.12 mm. The width of the measurement area 50 in the Z-axis direction is 0.5 mm, which is the total width of the sample, because the opening width is sufficiently large (v = 15 mm).

[0163] Figure 20 shows a 10 mm x 10 mm Image Sensor The imaging area 51 of 3 is shown by a solid line, and the first divided image 52, the second divided image 53, the third divided image 54, and the fourth divided image 55, which are four divided images of the above-mentioned measurement area 50 with an image magnification m = 20, are shown by thick dashed lines. However, for ease of understanding, it is assumed here that each divided image can measure light of all wavelength bands equally.

[0164] As shown in the figure, a right-handed XYZ orthogonal coordinate system common to FIG. 19 is defined. Note that the coordinate system symbols have been altered from their exact locations in Figure 20 for clarity. The horizontal left direction is the positive Y-axis direction ,Tare The upward direction is the positive direction of the Z axis ,OkuThe forward direction is the positive direction of the X-axis. Assuming that the image magnification m=1, the measurement area 50 and its four-divided images 52, 53, 54, and 55 are point-symmetric with respect to the intersections with the optical axis 4, and therefore, when the coordinate system is defined as above, the measurement area 50 and its four-divided images 52, 53, 54, and 55 appear to be identical, and the same characters are observed. In this embodiment, m=20, but since FIG. 20 shows FIG. 19 at a reduced size of 1 / 20, the measurement area 50 in FIG. 19 and the four-divided images 52, 53, 54, and 55 in FIG. 20 are identical (the same characters are written in the corresponding sections).

[0165] The width of each of the four divided images 52, 53, 54, and 55 in the Y-axis direction is 2×y m 20, the distance between the divided images is p=2.5 mm. The width of each divided image in the Z-axis direction is 0.5×m=10 mm. Thus, the four divided images 52, 53, 54, and 55 are measured simultaneously and independently without overlapping with each other, and it can be confirmed from FIG. 20 that the third condition is satisfied.

[0166] In Fig. 21, the above assumption in Fig. 20 is removed, and divided images 52, 53, 54, and 55 are made to selectively measure the emission fluorescence of the first phosphor, the second phosphor, the third phosphor, and the fourth phosphor, respectively. That is, the first divided image measures only the emission fluorescence of the first phosphor, the second divided image measures only the emission fluorescence of the second phosphor, the third divided image measures only the emission fluorescence of the third phosphor, and the fourth divided image measures only the emission fluorescence of the fourth phosphor.

[0167] As a result of the above, a 2.4 mm x 10 mm image of a 0.12 mm x 0.5 mm measurement area 50 on the sample surface 49, in which four types of phosphors are distributed two-dimensionally, is enlarged 20 times and divided into four parts in four colors, and these divided images are measured simultaneously and independently without overlapping with each other, making it possible to identify the two-dimensional distribution of each of the four types of phosphors on the measurement area 50.

[0168] By displaying these divided images 52, 53, 54, and 55 in an overlapping manner, it is possible to show the two-dimensional distribution of the four types of phosphors on the measurement area 50 in a single image.

[0169] In Fig. 22, the range of the measurement area 56 to be imaged on the sample surface 49 in Fig. 18 is shown by a thick dashed line in the first example of the first embodiment, that is, when D = 10 mm, w = 1.4 mm, p = 2.5 mm, h = 200 mm, d = 0 mm, m = 20, and x = 190 mm. These conditions are also shown in the lower part of Fig. 22. The width of the measurement area 56 in the Y-axis direction is, as mentioned above, 2 × y m = 0.1 mm. The width of the measurement area 56 in the Z-axis direction is 0.5 mm, which is the total width of the sample, because the opening width is sufficiently large (v = 15 mm).

[0170] Figure 23 shows a 10 mm x 10 mm Image Sensor The imaging area 51 of FIG. 3 is indicated by a solid line, and the first divided image 57, the second divided image 58, the third divided image 59, and the fourth divided image 60, which are four divided images of the measurement area 56 with an image magnification m=20, are indicated by thick dashed lines. As in FIG. 21, each divided image measures four colors of light in different wavelength bands.

[0171] As shown in the figure, a right-handed XYZ orthogonal coordinate system is defined, which is common to Figure 22. As in Figure 21, ,water The horizontal left direction is the positive Y-axis direction ,Tare The upward direction is the positive direction of the Z axis ,Oku The direction of travel is the positive X-axis direction. The width of each of the four divided images 57, 58, 59, and 60 in the Y-axis direction is 2×y m ×m=2 mm, and the mutual spacing is p=2.5 mm. Therefore, there is more space between the divided images compared to Figure 21. The width of each divided image in the Z-axis direction is 0.5×m=10 mm.

[0172] In this way, the four divided images 57, 58, 59, and 60 are measured simultaneously and independently without any overlap with each other, and it can be confirmed from FIG. 23 that the third condition is satisfied.

[0173] Divided images 57, 58, 59, and 60 selectively measure the emission fluorescence of the first phosphor, the second phosphor, the third phosphor, and the fourth phosphor, respectively. That is, the first divided image measures only the emission fluorescence of the first phosphor, the second divided image measures only the emission fluorescence of the second phosphor, the third divided image measures only the emission fluorescence of the third phosphor, and the fourth divided image measures only the emission fluorescence of the fourth phosphor.

[0174] As a result of the above, a 2 mm x 10 mm image of a 0.1 mm x 0.5 mm measurement area 56 on the sample surface 49, in which four types of phosphors are distributed two-dimensionally, is magnified 20 times and divided into four parts in four colors, and these divided images are measured simultaneously and independently without overlapping with each other, making it possible to identify the two-dimensional distribution of each of the four types of phosphors on the measurement area 56.

[0175] By displaying these divided images 57, 58, 59, and 60 in an overlapping manner, it is possible to show the two-dimensional distribution of the four types of phosphors on the measurement area 56 in a single image.

[0176] In Fig. 22 and Fig. 23, the spectral imaging of the snapshot method is performed on a measurement area 56 of 0.1 mm × 0.5 mm on a sample surface 49 distributed two-dimensionally. optics In order to perform spectral imaging of a wider range of measurement areas under the same instrument configuration and conditions, a scanning method was used. and the above snapshot method For example, in FIG. 13 and FIG. 14, by moving the sample including the measurement area 1 in the Y-axis direction, ,stomach Imaged measurement area 1 of Position On sample surface 49This allows for spectral imaging of a wider range of measurement areas on the sample.

[0177] Figures 24 to 28 ,stomach Imaged measurement area 56 Place of Place On sample surface 49 26 shows an example in which the measurement area 56 is changed. In Fig. 22, the measurement area 56 is fixed in the center of the sample surface 49. In contrast, in Figs. 24 to 28, the measurement area 56 moves from the left side (negative direction of the Y axis) to the right side (positive direction of the Y axis) on the sample surface 49 without overlapping or leaking. However, the measurement area 56 in Fig. 26 is the same as the measurement area 56 in Fig. 22.

[0178] Figures 29 to 33 show, For four-color spectral imaging of the sample surface, Measurement area 56 in each of Figures 24 to 28 4 of 4 Split image However, Figure 31 is the same as Figure 23. The results of Figures 29 to 33 are combined. Let By doing so, With one statue Four-color spectral imaging of the entire sample surface 49 is possible.

[0179] [Example 3] As shown in Examples 1 and 2, the spectral imaging of the snapshot method, which obtains an image having the spectral information of each point in the measurement area of ​​a two-dimensionally distributed sample at one time without scanning, is performed in the conventional manner as shown in Figs. 13 to 15. optical equipment Smaller, simpler, and less expensive than optics This can be achieved by the device configuration. optical equipment The high light utilization efficiency enables highly sensitive spectral imaging.

[0180] However, there may be a problem of slight focus shift between multiple split images that measure light of different wavelength bands (different colors). This is because the optical path lengths of the light beams that form the multiple split images are different from each other. SlightlyFor example, referring to FIG. 15, it is clear that the optical path length of C1 is smaller than the optical path length of C2, and the optical path length of C3 is smaller than the optical path length of C4.

[0181] These optical path length differences are Image Sensor The entire optical path length from the focusing lens 2 to the focusing lens 3, or the focusing lens 2 and Image Sensor Since this is small compared to the distance of 3, it can often be ignored. However, if all the divided images of C1 to C4 are Image Sensor The inability to focus precisely on one object can be problematic if multiple images with higher resolution need to be acquired simultaneously.

[0182] Patent Document 2 proposes to eliminate the above-mentioned optical path length difference by inserting optical path length adjustment elements of different thicknesses into each divided optical path. However, when optical path length adjustment elements of different thicknesses made of a transparent material with a refractive index of 2 were actually inserted into each divided optical path according to Figure 24(b) of Patent Document 2, it was found that, contrary to expectations, the focus deviation between the multiple divided images was rather amplified. A detailed investigation revealed that the configuration of Figure 24(b) of Patent Document 2 increases the optical path length difference between each divided optical path. It should be noted that in this specification, the position at which the image in each optical path is focused is and an image sensor The difference in distance is sometimes called the optical path difference.

[0183] Therefore, we reconsidered the principle of the method of eliminating the optical path length difference using an optical path length adjustment element, and at the same time, considered how to implement it simply, robustly, and at low cost, thereby devising a new method that functions as expected.

[0184] First, let us take a closer look at Figure 15. For example, Image Sensor On 3, focus on the split image of C1 but If Adjustment do.

[0185] In this case, since the optical path length of C1 is less than the optical path length of C2, the division image of C2 is Image Sensor Before 3 ( From Image Sensor 3 Therefore, if a transparent member with a refractive index greater than 1 is inserted only into the optical path of C2, the position in the X-axis direction (X coordinate) where the divided image of C2 is focused will be Image Sensor 3 (the X coordinate becomes larger). Here, no transparent member is inserted in the optical path of C1. In other words, no transparent member (e.g., a transparent solid member) is inserted in the optical path of the light beam with the shortest optical path length. In this way, the influence of the transparent member on the optical path can be avoided. In this way, by appropriately selecting the refractive index and thickness of the transparent member, Image Sensor On 3, it is possible to focus on the split image of C2.

[0186] Similarly, by inserting transparent members into the optical paths of C3 and C4, Image Sensor On the other hand, it is possible to focus the split images of C3 and C4 on the optical path of C3. However, the thickness of the transparent member inserted in the optical path of C3 is thicker than the thickness of the transparent member inserted in the optical path of C2. Also, the thickness of the transparent member inserted in the optical path of C4 is thicker than the thickness of the transparent member inserted in the optical path of C3.

[0187] In contrast, referring again to FIG. 24(b) of Patent Document 2, the thickness of the transparent member inserted in each optical path and the corresponding optical path length It can be seen that the relationship is the opposite of that described above. That is, no transparent member is inserted in the optical path of the light beam 24 (C4) having the longest optical path length, the thinnest transparent member is inserted in the optical path of the light beam 23 (C3) having the second longest optical path length, the second thinnest transparent member is inserted in the optical path of the light beam 22 (C2) having the third longest optical path length, and the thickest transparent member is inserted in the optical path of the light beam 21 (C1) having the shortest optical path length. For this reason, as described above, when the configuration of FIG. 24(b) of Patent Document 2 is implemented, the focus deviation between the multiple divided images is rather amplified, resulting in the opposite effect.

[0188] Based on the above considerations, a more suitable transparent member, that is, a more suitable optical path length adjustment element, is devised.

[0189] Condenser lens 2 and Image Sensor Among the multiple split light beams generated by the dichroic mirror array 43 disposed between the condenser lens 2 and Image Sensor The optical path length of the split beam with the shortest optical path length between 3 For, Let the optical path length difference of any divided light beam be Δh. Shortest The optical path length is Image Sensor The distance h between the light beams can be approximated by the distance h in the figure. Therefore, the optical path length of any split light beam can be expressed as h + Δh.

[0190] The position in the X-axis direction (X coordinate) where the split image of any split light beam is focused is displaced toward the front stage (negative direction of the X-axis) with Δh. On the other hand, if a refractive index n x ,When a transparent member with a thickness of t is inserted, the position in the X-axis direction (X coordinate) where the divided image is focused is (1-1 / n x ) × t to the rear stage (positive direction of the X-axis). Therefore, Δh = (1-1 / n x ) × t, i.e.,

number

[0191] As can be seen from (Equation 24), it is important to change t according to the Δh of the split light beam, more specifically, to increase t in proportion to the Δh of the split light beam. Image Sensor When the optical path length difference obtained by subtracting the shortest optical path length from any optical path length among the m optical path lengths between 3 is Δh, it is preferable that a transparent solid member of thickness t in the optical axis direction of the light beam having any optical path length is inserted in the optical path of the light beam having that any optical path length, and t and Δh are proportional to each other.

[0192] Also, the refractive index n xBy using a transparent member having a larger φ, the thickness t of the transparent member can be made thinner, making it easier to mount the optical path length adjustment element.

[0193] As described later, using a thicker transparent optical path length adjustment element is advantageous in terms of the aperture 17 and the aperture 18. Image Sensor Increasing the distance hx in 3, i.e. decreasing x and x / h, makes it difficult to satisfy the conditions (7), (21) to (23) suitable for spectral imaging. Therefore, the refractive index n x It is effective to use a transparent member having a larger diameter.

[0194] The transparent material may be, for example, glass or resin. Its refractive index is n x ≧1.60 is desirable, n x ≧1.80 is more preferable. Furthermore, the refractive index is n x It is more desirable to have a refractive index of n ≧ 2.00. Of course, it is also important to select a transparent material with high transmittance for the wavelength of the measurement target. In recent years, manufacturers such as AGC, Nippon Electric Glass, Corning, HOYA, and Sumita Optical Glass have released products with high transparency (transmittance) and a refractive index of n x Glass with a refractive index of ≥ 2.00 has been developed and is now on sale. It is effective to use such glass materials. Of course, it is also effective to use a highly transparent, high-refractive index resin.

[0195] The above-mentioned preferable optical path length adjusting element is shown in FIG. Dichroic mirror array In fact, when calculating the optical path length when using the dichroic mirror array 43 in Fig. 15, the optical path length is "optical path length of C2" - "optical path length of C1" = 2.1 mm, "optical path length of C3" - "optical path length of C1" = 4.6 mm, and "optical path length of C4" - "optical path length of C1" = 7.1 mm.

[0196] Here, the reduction in the optical path length of each beam is taken into consideration when it passes through the quartz glass with a refractive index of 1.46, which is the base material of each dichroic mirror. Therefore, if the optical path length of C1, which is the split beam with the shortest optical path length, is used as the reference, the optical path length difference of C1 is Δh = 0 mm, the optical path length difference of C2 is Δh = 2.1 mm, the optical path length difference of C3 is Δh = 4.6 mm, and the optical path length difference of C4 is Δh = 7.1 mm.

[0197] If a high refractive index glass with a refractive index of n = 2.00 is used as the material for the optical path length adjustment element, then according to (Equation 24), the thickness of the optical path C1 is t = 0 mm, the thickness of the optical path C2 is t = 4.2 mm, the thickness of the optical path C3 is t = 9.2 mm, and the thickness of the optical path C4 is t = 1.2 mm. 4 By inserting a high refractive index glass with a thickness of t = 14.2 mm into the optical path of C1, C2, C3, and C4, all the split images are Image Sensor It is now possible to focus on three simultaneously.

[0198] In the above, a high refractive index glass with a thickness of t=0 mm is inserted into the optical path of C1. In other words, no optical path length adjustment element is inserted into the optical path of C1. 0 When inserting high refractive index glass (≠0), the thickness of the C2 optical path is t=t 0 +4.2 mm, the thickness of the optical path of C3 is t=t 0 +9.2 mm, the thickness of the optical path of C4 is t=t 0 If a high refractive index glass of +14.2 mm is inserted, the same effect as above can be obtained. However, compared to the above, the diaphragm 17 and the aperture 18 are Image Sensor Distance hx to t 0 In other words, it is necessary to decrease x and x / h by the same amount. This makes it difficult to satisfy the conditions (7), (21) to (23) that are suitable for spectral imaging, so this method is not necessarily preferable.

[0199] In general, it is preferable not to insert an optical path length adjustment element into the optical path of the split beam having the shortest optical path length, but to insert an optical path length adjustment element into the optical paths of the other split beams. Also, it is preferable to increase the thickness of the optical path length adjustment element according to the difference between the optical path length of the split beam of the optical path to be inserted and the optical path length of the split beam having the shortest optical path length, more specifically, to increase the thickness in proportion to the difference.

[0200] Although (Equation 24) gives an optimal solution for the optical path length adjustment element, it goes without saying that the effect can be obtained even under conditions slightly different from this optimal solution.

number

number

[0201] It goes without saying that the above-mentioned configuration of the optical path length adjustment element will have the same effect when applied to any optical device, including the multi-color detection device as in Patent Document 2 and Patent Document 3, not limited to the spectral imaging device. In other words, a combination of any dichroic mirror array and the above-mentioned configuration of the optical path length adjustment element will produce the same effect. optics The device effectively cancels the optical path length difference inherent in the dichroic mirror array, making it possible to obtain good optical performance.

[0202] FIG. 34 shows the configuration of the dichroic mirror array 43 in FIG. Image Sensor The optical path length adjustment element is inserted between the aperture 17 and the aperture 18. Image SensorThe distance hx in 3 is expanded from 10 mm to 20 mm. That is, since h = 200 mm, x is reduced from 190 mm (x / h = 95%) to 180 mm (x / h = 90%). Also, in Figure 34, In Figure 15 The imaginary collimated light beam 48 is not shown.

[0203] The optical path length adjustment element is made of a transparent solid material. That is Refractive index n x = 2.00. The thickness of the optical path length adjustment element in the X-axis direction is calculated by (Equation 24). No optical path length adjustment element is inserted in the optical path of C1. The thickness in the X-axis direction of optical path length adjustment element 61 inserted in the optical path of C2 is t = 4.2 mm. The thickness in the X-axis direction of optical path length adjustment element 62 inserted in the optical path of C3 is t = 9.2 mm. The thickness in the X-axis direction of optical path length adjustment element 63 inserted in the optical path of C4 is t = 14.2 mm. The width in the Y-axis direction of optical path length adjustment elements 61, 62, and 63 is all 2.5 mm, and the depth in the Z-axis direction is all 15 mm.

[0204] In this way, a transparent solid member whose thickness changes according to the optical path length difference of the m light beams may be inserted in the optical path of any one of the m light beams that form the image divided into m pieces.

[0205] Optical path length adjusting elements 61, 62, and 63 Enter The entrance surface and the exit surface are each perpendicular to the X-axis, and the direction of the entrance surface of each optical path length adjustment element is the negative direction of the X-axis (the direction toward the dichroic mirror array 43), and the direction of the exit surface is the positive direction of the X-axis ( Image Sensor (direction toward 3).

[0206] At least these Optical path length adjustment element It is also important to optically polish the incident and exit surfaces to suppress reflection and scattering of light at the incident and exit surfaces. However, it is not necessary for the entire incident and exit surfaces to be optically polished, and it is advisable to at least optically polish the areas on the incident and exit surfaces through which each divided light beam passes.

[0207] The optical path length adjustment elements 61 and 62, and the optical path length adjustment elements 62 and 63 are joined at their sides perpendicular to the Y axis, respectively, and the optical path length adjustment elements 61, 62, and 63 are integrated together. In this manner, any two adjacent transparent solid members may be joined. ,Multiple Alternatively, multiple transparent solid members may be integrated into one body. These joining surfaces (surfaces where two adjacent transparent solid members are joined) are transparent, allowing the light beam to pass through the joining surfaces. It is preferable that the side surfaces perpendicular to the Y axis other than the joining surfaces, specifically, the side surface in the negative Y-axis direction of the optical path length adjustment element 61, the side surface in the negative Y-axis direction of the optical path length adjustment element 62, and both side surfaces in the negative Y-axis direction and the positive Y-axis direction of the optical path length adjustment element 63, are optically polished. In addition, as shown in FIG. 34, the X coordinates of the emission surfaces of the optical path length adjustment elements 61, 62, and 63 are aligned, and the emission surfaces are aligned on the same plane.

[0208] In contrast to the above, in Fig. 24(b) of Patent Document 2, the optical path length adjustment elements 77, 78, and 79 are not integrated. In this respect as well, the configurations of Fig. 34 and Fig. 24(b) of Patent Document 2 differ.

[0209] Integrating the optical path length adjusting elements 61, 62, and 63 in this manner brings about the following effects.

[0210] First, the optical path length adjustment elements can be easily handled and aligned. If the optical path length adjustment elements 61, 62, and 63 are not integrated, they must be handled and aligned individually. However, as described above, each optical path length adjustment element is minute, so it is difficult to handle and align each one individually, and there is a high possibility that the mechanism for implementing this will become large and expensive.

[0211] Next, the width in the Y-axis direction of the optical path length adjustment elements 61, 62, and 63 can be expanded to the same as the arrangement interval p=2.5 mm in the Y-axis direction of the dichroic mirrors M1, M2, M3, and M4. This makes it possible to avoid, for example, optical vignetting caused by the optical path length adjustment elements due to the insertion of the optical path length adjustment elements, which would effectively reduce the width w in the Y-axis direction of the opening 18 of the dichroic mirror array 43. Alternatively, when the positions of the split light beams C1 to C4 are displaced in the Y-axis direction for some reason, or when the optical path length adjustment elements are displaced in the Y-axis direction, each split light beam may come off the optical path length adjustment element, Image Sensor It is possible to reduce the risk of a reduction in the amount of light reaching 3 and to measure each divided image well.

[0212] In addition, aligning the exit surfaces of the optical path length adjustment elements 61, 62, and 63 on the same plane brings about the following effects. First, the angle of the optical path length adjustment elements is reduced, thereby reducing the risk of each divided light beam being scattered at the angle. Second, it becomes easier to perform optical polishing of at least the exit surface. These effects can also be obtained by aligning the entrance surfaces, rather than the exit surfaces, of the optical path length adjustment elements 61, 62, and 63 on the same plane. The unique effects of aligning the exit surfaces of the optical path length adjustment elements 61, 62, and 63 on the same plane are as follows: A stepped arrangement of the incident surfaces of the optical path length adjusting elements 61, 62, and 63; Dichroic Mirror Array 43 Each dichroic mirror stepped of array And Bringing it close, specifically, the optical path length adjustment element 63 can be brought close to the dichroic mirror M4, and hx can be reduced.

[0213] Furthermore, making the coupling surfaces of the optical path length adjustment elements 61, 62, and 63 transparent brings about the following effect. At least a part of each split light beam passes through the coupling surface. Image SensorSince an image can be formed on the dichroic mirror array 43, it is possible to avoid an effective reduction in the width w of the opening 18 in the Y-axis direction of the dichroic mirror array 43 due to the insertion of the optical path length adjustment element. Alternatively, when the positions of the split light beams C1 to C4 are displaced in the Y-axis direction for some reason, or when the optical path length adjustment element is displaced in the Y-axis direction, each split light beam may come off the optical path length adjustment element, Image Sensor It is possible to reduce the risk of a reduction in the amount of light reaching 3 and to measure each divided image well.

[0214] The integrated optical path length adjustment element of FIG. 34 can be fabricated in the following three ways.

[0215] The first method is injection molding. In particular, when the transparent member is made of resin, injection molding can be used to mass-produce integrated optical path length adjustment elements at low cost. In recent years, injection molding has also become possible when the transparent member is made of glass, as shown in Figure 34.

[0216] The second method is to cut a block of a transparent material. With this method, it is somewhat difficult to optically polish the entire incident surface and exit surface of the integrated optical path length adjustment element after finishing into the shape of Fig. 34. Specifically, it is physically difficult to optically polish the area of ​​the incident surface of optical path length adjustment element 61 near optical path length adjustment element 62, and the area of ​​the incident surface of optical path length adjustment element 62 near optical path length adjustment element 63. However, since it is easy to prevent each split light beam from passing through these areas, these areas may be excluded from the target of optical polishing.

[0217] The third method is a method of bonding the joint surfaces of the separately manufactured optical path length adjustment elements 61, 62, and 63 with an adhesive or the like. With this method, it is easy to optically polish the entire entrance and exit surfaces or side surfaces of the optical path length adjustment elements 61, 62, and 63 before bonding. In addition, the joint surfaces can be made transparent by using a transparent adhesive to make the adhesive layer sufficiently thin. The higher the refractive index of the adhesive, the better, and the closer it is to the refractive index of the optical path length adjustment elements. In the third method, a method may be used in which the optical path length adjustment elements 61, 62, and 63 manufactured separately are compressed in a stacked state using a dedicated device without using an adhesive. The integrated optical path length adjustment element in FIG. 34 is manufactured by the third method.

[0218] In the above, the same refractive index n x Although transparent members with different thicknesses t are inserted, this is not necessarily required. That is, different refractive indices n x However, in this case, it is better to satisfy (Equation 24) to (Equation 26). For example, the thickness t of the transparent member inserted in the optical path of the other light beams, except for the light beam with the shortest optical path length, should be the same. According to (Eq. 24) to (Eq. 26), Refractive index n x In this way, unlike the stepped optical path length adjustment elements 61, 62, and 63 in FIG. 34, the optical path length adjustment elements 61, 62, and 63 become rectangular parallelepipeds, and thus the handling and alignment of the optical path length adjustment elements 61, 62, and 63 become easier.

[0219] In Fig. 35, the bonding surfaces and side surfaces of the optical path length adjustment elements 61, 62, and 63 in Fig. 34 are made opaque. In this way, the surface where any two adjacent transparent solid members are bonded may be opaque. Specifically, a black light absorbing thin film 64 is provided on the bonding surface and the side surface perpendicular to the Y axis. This configuration makes it possible to avoid interference between different split light beams, making it easier to measure the image of each split light beam independently. Alternatively, it is possible to avoid a deterioration in the quality of the split image caused by each split light beam being reflected by the bonding surface and side surface and overlapping with its own split image.

[0220] Instead of the spectral imaging device according to the configurations of Example 2, FIGS. 13, 14, and 15, the spectral imaging device according to the configurations of Example 2, FIGS. 13, 14, and 34 is used, so that all of the four-division images can be captured. Image Sensor It is now possible to focus on 3.

[0221] The conditions in the configurations of Example 2, Figures 13, 14, and 15 are D=10 mm, w=1.4 mm, p=2.5 mm, h=200 mm, d=0 mm, m=20, x=185 mm or 190 mm (x / h=93% or 95%), and the third condition of (Equation 23) is satisfied. On the other hand, the conditions in the configurations of Example 2, Figures 13, 14, and 34 are D=10 mm, w=1.4 mm, p=2.5 mm, h=200 mm, d=0 mm, m=20, x=180 mm (x / h=90%), and the second condition of (Equation 22) is satisfied, but the third condition of (Equation 23) is not satisfied. Therefore, at least a part of the four-part images overlap each other. In order to solve this newly occurring problem, the following ideas were added.

[0222] The specifications of the condenser lens 2 are changed from f=9.52 mm, D=10 mm to f=19.05 mm, D=10 mm. Image SensorThe distance 3 is changed from h=200 mm to h=400 mm. At this time, g=20 mm from (Equation 1), and m=20 from (Equation 2). Also, as shown in FIG. 34, since hx=20 mm, x=380 mm, and x / h=95%. Therefore, by these changes, the third condition of (Equation 23) is satisfied while using the configuration shown in FIG. 34, and it is possible to prevent the four-part images from overlapping each other at all. Also, since m=20 is maintained, it is possible to obtain the same four-part images as those in FIG. 23, FIG. 29 to FIG. 33. Furthermore, it is possible to focus on all the four-part images even more precisely than in the case of the second embodiment.

[0223] [Example 4] In the above embodiment, four-color spectral imaging is performed using a four-division dichroic mirror array, whereas in the present embodiment, nine-color spectral imaging is performed using a nine-division dichroic mirror array.

[0224] The device configuration follows Figures 13 and 14, except for the dichroic mirror array. That is, a condenser lens 2 with f = 9.52 mm and D = 10 mm is used, and h = 200 mm is set based on the design of the condenser lens 2. In this case, g = 1 mm from (Equation 1), and m = 20 from (Equation 2). However, Image Sensor The size of 3 is expanded to 15 mm (width in the Y-axis direction) x 10 mm (width in the Z-axis direction).

[0225] FIG. 36 shows a nine-division dichroic mirror array 65, a diaphragm 17 and an aperture 18, which are similar to FIG. 29 of Patent Document 3. Image Sensor 15, a right-handed XYZ orthogonal coordinate system is defined in the figure. Note that the coordinate system symbols have been altered from their exact locations in Figure 36 for clarity. Only the optical axes of the light beam C0 entering the dichroic mirror array 65 and the nine split light beams C1 to C9 that are split and emitted from the dichroic mirror array 65 are shown; the virtual parallel light beam 48 is not shown.

[0226] The bandpass filter BP is placed just after the aperture 18 ( Opening 18 X-axis positive side), and further behind it ( Bandpass filter BP Dichroic mirror M1 is placed on the right side (positive direction of the X-axis). Next, starting from dichroic mirror M1, four dichroic mirrors M2, M3, M4, and M5 are arranged at equal intervals to the right (positive direction of the Y-axis) and are offset in a stepped manner in the X-axis direction. The entrance and exit surfaces of dichroic mirrors M1 to M5 are arranged so as to be perpendicular to the straight line Y = -X on the XY plane.

[0227] On the other hand, the rear stage of the dichroic mirror M1 ( Dichroic mirror M1 Dichroic mirror M6 is placed on the left side (positive direction of the X-axis). Next, starting from dichroic mirror M6, four dichroic mirrors M7, M8, M9, and M10 are arranged at equal intervals to the left (negative direction of the Y-axis) and are offset in a staircase-like manner in the X-axis direction. The entrance and exit surfaces of dichroic mirrors M6 to M10 are arranged so as to be perpendicular to the straight line Y=X on the XY plane.

[0228] The light beam C0 passes through the aperture 18 along the optical axis 4, as in FIG. 15, and is transmitted through the bandpass filter BP. Laser beam 4 of 5 The reflected or scattered light is blocked by the dichroic mirror 46 in the same manner as in FIG. 13 (is reflected without passing through the dichroic mirror 46), but is further blocked by the bandpass filter BP.

[0229] The light beam C0 that passes through the bandpass filter BP enters the dichroic mirror M1 and is split into reflected light traveling in the positive direction of the Y axis and transmitted light traveling in the positive direction of the X axis. The light beam reflected by the dichroic mirror M1 enters the dichroic mirror M2 and is split into transmitted light traveling in the positive direction of the Y axis and reflected light traveling in the positive direction of the X axis. This reflected light is the split light beam C1, Image Sensor 3 is incident perpendicularly to Imaged The light beam transmitted through the dichroic mirror M2 enters the dichroic mirror M3 and is split into a transmitted light beam traveling in the positive direction of the Y axis and a reflected light beam traveling in the positive direction of the X axis. This reflected light is the split light beam C2, Image Sensor 3 is incident perpendicularly to ImagedThe light beam transmitted through dichroic mirror M3 enters dichroic mirror M4 and is split into a transmitted light beam traveling in the positive direction of the Y axis and a reflected light beam traveling in the positive direction of the X axis. This reflected light is a split light beam C3, Image Sensor 3 is incident perpendicularly to Imaged The light beam transmitted through the dichroic mirror M4 is incident on and reflected by the dichroic mirror M5, becoming reflected light traveling in the positive direction of the X-axis. This reflected light is the split light beam C4, Image Sensor 3 is incident perpendicularly to Imaged do.

[0230] On the other hand, the light beam transmitted through the dichroic mirror M1 enters the dichroic mirror M6 and is split into a transmitted light beam traveling in the positive direction of the X-axis and a reflected light beam traveling in the negative direction of the Y-axis. This transmitted light is a split light beam C5, Image Sensor 3 is incident perpendicularly to Imaged The light beam reflected by the dichroic mirror M6 enters the dichroic mirror M7 and is split into a transmitted light beam traveling in the negative direction of the Y axis and a reflected light beam traveling in the positive direction of the X axis. This reflected light is a split light beam C6, Image Sensor 3 is incident perpendicularly to Imaged The light beam transmitted through the dichroic mirror M7 enters the dichroic mirror M8 and is split into a transmitted light beam traveling in the negative direction of the Y axis and a reflected light beam traveling in the positive direction of the X axis. This reflected light is a split light beam C7, Image Sensor 3 is incident perpendicularly to Imaged The light beam transmitted through the dichroic mirror M8 enters the dichroic mirror M9 and is split into a transmitted light traveling in the negative direction of the Y axis and a reflected light traveling in the positive direction of the X axis. This reflected light is a split light beam C8, which is perpendicularly incident on the image sensor 3. Imaged The light beam transmitted through the dichroic mirror M9 is incident on and reflected by the dichroic mirror M10, becoming reflected light traveling in the positive direction of the X-axis. This reflected light is the split light beam C9, Image Sensor 3 is incident perpendicularly to Imaged do.

[0231] The substrate of the bandpass filter BP and the dichroic mirrors M1 to M10 is quartz glass with a refractive index of 1.46, and the size is width a = 1.9 mm (parallel to the XY plane and Filter or The dimension parallel to the incidence surface of the dichroic mirror), thickness b = 0.5 mm (parallel to the XY plane and Filter or The dichroic mirror has a diameter of 15 mm (dimension perpendicular to the incidence surface of the dichroic mirror) and a depth c = 15 mm (dimension parallel to the Z axis, not shown).

[0232] The arrangement intervals of the dichroic mirrors M1 to M5 and the dichroic mirrors M6 to M10 in the Y-axis direction are each 1.6 mm. However, as can be seen by analyzing FIG. 36 in detail, the distance between the divided image of C1 and the divided image of C2, the distance between the divided image of C2 and the divided image of C3, the distance between the divided image of C3 and the divided image of C4, the distance between the divided image of C6 and the divided image of C7, the distance between the divided image of C7 and the divided image of C8, and the distance between the divided image of C8 and the divided image of C9 are each 1.6 mm, and the distance between the divided image of C1 and the divided image of C5, and the distance between the divided image of C5 and the divided image of C6 are slightly smaller than 1.6 mm. In this embodiment, the most frequent value of 1.6 mm is set as the division pitch, and p=1.6 mm.

[0233] Also, the dichroic mirror array 65 is shifted in a step-like manner in the X-axis direction. That is, the dichroic mirror M2 is shifted 0.35 mm in the negative X-axis direction from the dichroic mirror M1, the dichroic mirror M3 is shifted 0.16 mm in the negative X-axis direction from the dichroic mirror M2, the dichroic mirror M4 is shifted 0.16 mm in the negative X-axis direction from the dichroic mirror M3, and the dichroic mirror M5 is shifted 0.16 mm in the negative X-axis direction from the dichroic mirror M4. Also, the dichroic mirror M7 is shifted 0.35 mm in the negative X-axis direction from the dichroic mirror M6, the dichroic mirror M8 is shifted 0.16 mm in the negative X-axis direction from the dichroic mirror M7, the dichroic mirror M9 is shifted 0.16 mm in the negative X-axis direction from the dichroic mirror M8, and the dichroic mirror M10 is shifted 0.16 mm in the negative X-axis direction from the dichroic mirror M9. With the above configuration, an aperture width w = 1 mm is obtained, as shown in Fig. 36. The aperture width in the depth direction is v = 15 mm (not shown). Since the effective diameter of the focusing lens 2 is D = 10 mm, (Equation 6) is satisfied.

[0234] On the other hand, as shown in Figure 36, hx = 10 mm and h = 200 mm, so x = 190 mm and x / h = 95%. Therefore, the third condition (Equation 23) is satisfied, and it is possible to simultaneously measure nine divided images without overlapping each other. In other words, it is possible to perform spectral imaging using the snapshot method to measure nine wavelength bands (nine colors).

[0235] Below, a suitable structure of the above dichroic mirror array will be generalized following Patent Document 3.

[0236] In the right-handed XYZ Cartesian coordinate system, In the dichroic mirror array, m dichroic mirrors DA1 to DAm, where m is 2 or more, are arranged parallel to each other along the positive direction of the Y axis, and are ordered as DA1, DA2, ..., DAm from the negative to the positive direction of the Y axis. The dichroic mirror array further includes n dichroic mirrors DB1 to DBn, where n is an integer of 2 or more, and are arranged parallel to each other from the positive to the negative direction of the Y axis, DB1, DB2, ..., DBn. .D The ichroic mirror DA1 and the dichroic mirror DB1 are arranged along the X-axis. In this dichroic mirror array, (1) The incident planes of the dichroic mirrors DA1 to DAm and DB1 to DBn are perpendicular to the XY plane, (2) On the XY plane The inclination of the straight line projected onto the XY plane from the normal to the incident surface of the dichroic mirrors DA1 to DAm is negative. On the XY plane The inclination of the straight line projected onto the XY plane from the normal to the incident surface of the dichroic mirrors DB1 to DBn is positive, and the angle that the normal to the incident surface of the dichroic mirrors DA1 to DAm and the dichroic mirrors DB1 to DBn make with the X-axis is θ 0 year, (3) Let the refractive index of the substrate of the dichroic mirrors DA1 to DAm and DB1 to DBn be n. 0, the average width parallel to the XY plane and perpendicular to the normal to the incident surface is a, and the average width parallel to the XY plane and parallel to the normal to the incident surface is b. (4) When comparing the positions of two adjacent dichroic mirrors DAj and DA(j+1) (where 1≦j≦(m-1)) on the XY plane, the Y coordinate of the dichroic mirror DA(j+1) is larger, and the X coordinate of the dichroic mirror DAj is larger. (5) Comparing the positions of two adjacent dichroic mirrors DBj and DB(j+1) (where 1≦j≦(n-1)) on the XY plane, the Y and X coordinates of the dichroic mirror DBj are both larger. (6) Two adjacent dichroic mirrors, DA1 and DB1, are on the X-axis, and the X-coordinate of the dichroic mirror DB1 is larger than the X-coordinate of the dichroic mirror DA1. (7) When the average arrangement interval in the Y-axis direction of two adjacent dichroic mirrors DAj and DA(j+1) (where 2≦j≦(m-1)) and the average arrangement interval in the X-axis direction of two adjacent dichroic mirrors DBj and DB(j+1) (where 2≦j≦(n-1)) is Δy and Δx, respectively, In order to enlarge the aperture width of the dichroic mirror array in the Y-axis direction and reduce the optical path length of the dichroic mirror array, θ 0 ,n 0 , a, b, Δy, and Δx satisfy a specified relationship. Specifically, it is better to satisfy (Formula A) or (Formula B). (8) The average of the arrangement interval in the Y-axis direction of two adjacent dichroic mirrors DA1 and DA2 and the arrangement interval in the Y-axis direction of two adjacent dichroic mirrors DB1 and DB2 is Δy 0 The average of the arrangement interval in the X-axis direction of two adjacent dichroic mirrors DA1 and DA2 and the arrangement interval in the X-axis direction of two adjacent dichroic mirrors DB1 and DB2 is Δx 0 When this is done, it is advisable to satisfy (Equation C) or (Equation D). 0 In many cases, a setting of θ = 45° is most effective. 0If ≠ 45°, Image Sensor is not parallel to the YZ plane, for example, θ 0 or θ 0 In some cases, tilting it by -45° is sufficient.

[0237] However, as in Figure 15, the optical path lengths of the light beams forming the nine divided images are different from each other, Image Sensor It is difficult to precisely focus all nine divided images on the focusing lens 3. Therefore, as in Figures 34 and 35, an optical path length adjustment element is used to cancel the difference in optical path length between the light beams, thereby solving the above-mentioned difficulty. In addition, as in Example 3, the specifications of the focusing lens 2 are changed from f=9.52 mm, D=10 mm to f=19.05 mm, D=10 mm, and the focusing lens 2 and Image Sensor Change the distance of 3 from h=200 mm to h=400 mm.

[0238] In the dichroic mirror array 43 shown in Fig. 15, multiple dichroic mirrors are arranged in one direction (positive direction of the Y-axis). In contrast, in the dichroic mirror array 65 shown in Fig. 36, multiple dichroic mirrors are arranged in two mutually opposite directions (positive direction of the Y-axis and negative direction of the Y-axis). Therefore, when comparing dichroic mirror arrays with the same number of divisions, the maximum optical path length difference can be made smaller in the case of Fig. 36. This effect is described in detail in Patent Document 3.

[0239] Therefore, by using the optical path length adjustment element proposed in this specification, In the dichroic mirror array according to FIG. This is even more advantageous since the thickness of the optical path length adjustment element can be made thinner when canceling the optical path length difference. In other words, the effect is even greater when the method disclosed in this specification is combined with the method of Patent Document 3.

[0240] The optical path length difference of each divided light beam is calculated when the dichroic mirror array 65 in Fig. 36 is used. Taking C5, which has the shortest optical path length, as the reference, and assuming that the optical path length difference of C5 is Δh = 0 mm, the optical path length difference of C1 is Δh = 1.7 mm, the optical path length difference of C2 is Δh = 3.2 mm, the optical path length difference of C3 is Δh = 4.8 mm, the optical path length difference of C4 is Δh = 6.3 mm, the optical path length difference of C6 is Δh = 1.4 mm, the optical path length difference of C7 is Δh = 2.9 mm, the optical path length difference of C8 is Δh = 4.5 mm, and the optical path length difference of C9 is Δh = 6.0 mm.

[0241] Here, the reduction in the optical path length when each light beam passes through the quartz glass with a refractive index of 1.46, which is the base material of each dichroic mirror, is taken into consideration. x If we use high refractive index glass with a refractive index of 2.00, then, according to (Equation 24), we can insert high refractive index glass with a thickness of t = 3.4 mm in the optical path of C1, a thickness of t = 6.5 mm in the optical path of C2, a thickness of t = 9.6 mm in the optical path of C3, a thickness of t = 12.7 mm in the optical path of C4, a thickness of t = 0.0 mm (no high refractive index glass is inserted) in the optical path of C5, a thickness of t = 2.7 mm in the optical path of C6, a thickness of t = 5.8 mm in the optical path of C7, a thickness of t = 8.9 mm in the optical path of C8, and a thickness of t = 12.1 mm in the optical path of C9, thereby achieving the desired splitting of all the divisions C1 to C9. luminous flux of Image Sensor It is now possible to focus on three objects at the same time.

[0242] FIG. 37 shows the configuration of FIG. 36 with the dichroic mirror array 65. Image Sensor The optical path length adjustment element is inserted between the aperture 17 and the aperture 18. Image Sensor The distance hx in 3 is expanded from 10 mm to 20 mm. In this case, g = 20 mm from (Equation 1), and m = 20 from (Equation 2). Also, since h = 400 mm, x = 380 mm, and x / h = 95%. Therefore, Configuration of Figure 37 Therefore, the third condition of (Eq. 23) is satisfied, and the nine divided images do not overlap each other at all.

[0243] The material of the optical path length adjustment element has a refractive index of n x =2.00. The thickness in the X-axis direction of the optical path length adjustment element 75 inserted in the split optical path of C1 is t=3.4 mm. The thickness in the X-axis direction of the optical path length adjustment element 76 inserted in the split optical path of C2 is t=6.5 mm. The thickness in the X-axis direction of the optical path length adjustment element 77 inserted in the split optical path of C3 is t=9.6 mm. The thickness in the X-axis direction of the optical path length adjustment element 78 inserted in the split optical path of C4 is t=12.7 mm. No optical path length adjustment element is inserted in the split optical path of C5. The thickness in the X-axis direction of the optical path length adjustment element 79 inserted in the split optical path of C6 is t=2.7 mm. The thickness in the X-axis direction of the optical path length adjustment element 80 inserted in the split optical path of C7 is t=5.8 mm. The thickness in the X-axis direction of the optical path length adjustment element 81 inserted in the split optical path of C8 is t=8.9 mm. The thickness in the X-axis direction of the optical path length adjustment element 82 inserted in the split optical path of C9 is t = 12.1 mm. The width in the Y-axis direction of each of the optical path length adjustment elements 75 to 82 is 1.6 mm, and the depth in the Z-axis direction is each 15 mm.

[0244] Optical path length adjustment element 75~82 Enter The entrance surface and the exit surface are each perpendicular to the X-axis, and the direction of the entrance surface of each optical path length adjustment element is the negative direction of the X-axis (the direction toward the dichroic mirror array 64), and the direction of the exit surface is the positive direction of the X-axis ( Image Sensor (direction toward 3).

[0245] At least the areas on the entrance surface and the exit surface through which each split light beam passes are optically polished. The sides perpendicular to the Y axis between the optical path length adjustment elements 75 and 76, between the optical path length adjustment elements 76 and 77, and between the optical path length adjustment elements 77 and 78 are respectively coupled, and the optical path length adjustment elements 75 to 78 are integrated. Meanwhile, the sides perpendicular to the Y axis between the optical path length adjustment elements 79 and 80, between the optical path length adjustment elements 80 and 81, and between the optical path length adjustment elements 81 and 82 are respectively coupled, and the optical path length adjustment elements 79 to 82 are integrated. As in FIG. 35, a black light absorbing thin film 64 is provided on each coupling surface and on the side perpendicular to the Y axis.

[0246] In addition, the X coordinates of the emission surfaces of the optical path length adjustment elements 75 to 82 are aligned, and the emission surfaces are aligned on the same plane. Figure 38 shows the optical path length adjustment elements 75 to 82 in Figure 37, observed from a direction perpendicular to the YZ plane. The optical path length adjustment elements 75 to 78 and the optical path length adjustment elements 79 to 82 are Optical path length adjustment element Perpendicular to the Z axis Face At Bridge 83 By fixing The optical path length adjustment elements 75 to 82 are coupled together to form an integrated whole. Integrating the optical path length adjustment elements 75 to 82 in this manner brings about the same effects as in the third embodiment.

[0247] In Fig. 39, similar to Fig. 22, the range of the measurement area 84 to be imaged when D = 10 mm, w = 1 mm, p = 1.6 mm, h = 400 mm, d = 0 mm, m = 20, and x = 380 mm is shown by a thick dashed line on the sample surface 49. These conditions are also shown at the bottom of Fig. 39.

[0248] At this time, from (Equation 20), y m = 0.04 mm, the width of the measurement area 84 in the Y-axis direction is 2 × y m = 0.08 mm. The width of the measurement area 84 in the Z-axis direction is 0.5 mm, which is the total width of the sample, because the opening width is sufficiently large (v = 15 mm).

[0249] The notation of the sample surface 49 is the same as that in FIG. 18. However, the letters written in each section indicate the local distribution of nine types of phosphors, and each letter emits fluorescence when irradiated with a laser beam. Specifically, it is as follows. Each of the letters in the first line (first letter is A), the tenth line (first letter is J), and the 19th line (first letter is S) is labeled with a first phosphor, and the emitted fluorescence of the first phosphor is measured only in the divided image of C1. Each of the letters in the second line (first letter is B), the eleventh line (first letter is K), and the 20th line (first letter is T) is labeled with a second phosphor, and the emitted fluorescence of the second phosphor is measured only in the divided image of C2. Each of the letters in the third line (first letter is C) and the twelfth line (first letter is L) is labeled with a third phosphor, and the emitted fluorescence of the third phosphor is measured only in the divided image of C3. The letters in the 4th line (first letter is D) and the 13th line (first letter is M) are labeled with the 4th fluorophore, and the emission fluorescence of the 4th fluorophore is measured only in the segmented image of C4. The letters in the 5th line (first letter is E) and the 14th line (first letter is N) are labeled with the 5th fluorophore, and the emission fluorescence of the 5th fluorophore is measured only in the segmented image of C5. The letters in the 6th line (first letter is F) and the 15th line (first letter is O) are labeled with the 6th fluorophore, and the emission fluorescence of the 6th fluorophore is measured only in the segmented image of C6. The letters in the 7th line (first letter is G) and the 16th line (first letter is P) are labeled with the 7th fluorophore, and the emission fluorescence of the 7th fluorophore is measured only in the segmented image of C7. The letters in the 8th row (first letter is H) and the 17th row (first letter is Q) are labeled with the 8th fluorophore, and the emission fluorescence of the 8th fluorophore is measured only in the segmented image of C8. The letters in the 9th row (first letter is I) and the 18th row (first letter is R) are labeled with the 9th fluorophore, and the emission fluorescence of the 9th fluorophore is measured only in the segmented image of C9.

[0250] Figure 40 shows a 15 mm × 10 mm square tube similar to Figure 23. Image Sensor The imaging area 51 of 3 is shown by a solid line, and the imaging area 51 of C1 is a 9-division image of the above measurement area 84 with an image magnification m = 20. 1. Split image 85, C2 Second Split image 86, C3 ThirdDivision image 87, C4 Fourth Split image 88, C5 Fifth Division image 89, C6 Sixth Split image 90, C7 Seventh Split image 91, C8 8th Split image 92, C9 9th The divided images 93 are indicated by thick dashed lines. Each divided image measures nine colors of light in different wavelength bands.

[0251] The width of each of the 9-division images 85 to 93 in the Y-axis direction is 2×y m ×m=1.6 mm, and the mutual interval is p=1.6 mm. Therefore, the 9-division images 85-93 are measured simultaneously and independently without overlapping each other, and it can be confirmed from Figure 40 that the third condition is satisfied. In addition, the total width in the Y-axis direction of the 9-division images 85-93 is 1.6×9=14.4 mm, Image Sensor 3 falls within the 15 mm width in the Y-axis direction of the imaging area 51.

[0252] C1 1. In the split image, only the emission fluorescence of the first phosphor is measured, and the fluorescence of C2 Second In the split image, only the emission fluorescence of the second phosphor is measured, and the fluorescence of C3 Third In the split image, only the emission fluorescence of the third phosphor was measured, and the fluorescence of C4 Fourth In the split image, only the emission fluorescence of the fourth phosphor was measured, and the fluorescence of C5 Fifth In the split image, only the emission fluorescence of the fifth fluorophore was measured, and the fluorescence of C6 Sixth In the split image, only the emission fluorescence of the sixth fluorophore was measured, and the fluorescence of C7 Seventh In the split image, only the emission fluorescence of the seventh phosphor was measured, and the fluorescence of C8 8th In the split image, only the emission fluorescence of the eighth phosphor was measured, and the fluorescence of C9 9th In the split image, only the emitted fluorescence of the ninth fluorophore is measured.

[0253] As described above, a 1.6 mm x 10 mm image of a 0.08 mm x 0.5 mm measurement area 84 on the sample surface 49, in which nine types of phosphors are distributed two-dimensionally, is magnified 20 times and divided into nine parts for nine colors, and these divided images are measured simultaneously and independently without overlapping each other, making it possible to identify the two-dimensional distribution of each of the nine types of phosphors on the measurement area 84. By displaying these divided images 85 to 93 in an overlapping manner, it is also possible to show the two-dimensional distribution of the nine types of phosphors on the measurement area 84 in a single image. Furthermore, since all nine divided images can be precisely focused, spectral imaging with high resolution and high analytical accuracy is possible. [Explanation of symbols]

[0254] 1 Measuring area 2 Condenser lens 3 Image Sensor 4 Optical axis 5~7 Light Emitting Region 8~10 Light-emitting area image 9A A light emitting area image 9B B light emitting area image 9C C luminous area image 11-12 From light emitting area 5 Light bundle 11 Left contour of light beam 11-12 12 Right-side contour of light beam 11-12 13-14 From luminous area 6 Light bundle 13 Left contour of light beam 13-14 14 Right-side contour of light beam 13-14 15-16 From luminous area 7 Light bundle 15 Left contour of beam 15-16 16 Right-side contour of beam 15-16 17 Aperture 18 Aperture 19~21 Weak emission area image 19A~21A Weak A light emission area image 19B~21B Weak B emission area image 19C~21C Weak C emission area image 43 Dichroic Mirror Array 44 Laser light source 45 Laser Beam 46 Dichroic Mirror 47 Longpass Filter 48 Parallel beam 49 Sample Surface 50 measurement fixed area 51 Image Sensor 3. Imaging Area 52~55 Four-division image of measurement area 50 56 measurement fixed area 57~60 4-division image of measurement area 56 61-63 Optical path length adjustment element 64 Black Light absorbing thin film 65 Dichroic Mirror Array 75~82 Optical path length adjustment element 83 Bridge 84 Measurement area 85~93 Measurement area 84 9 Divided image A Dichroic Mirror B Dichroic mirror BP Bandpass Filter C Dichroic Mirror C0 luminous flux C1~C4 split luminous flux D Effective diameter of condenser lens D1~Dm Dichroic mirror E detection efficiency M1~M10 Dichroic mirrors a each The width of the dichroic mirror parallel to the plane of incidence on the plane that contains the optical axis of the split light beam b each The width of the dichroic mirror in the direction perpendicular to the plane of incidence, on the plane that contains the optical axis of the split light beam. d Size of the light-emitting area in the direction of the dichroic mirror array d' Size of the weak emission area image in the direction of the dichroic mirror array g Distance between the condenser lens and the sample h Condenser lens and Image Sensor Distance m Image magnification p Division pitch v A plane perpendicular to the optical axis of each split beam Aperture width of dichroic mirror array in the direction w is the aperture width of the dichroic mirror array in the direction in which the dichroic mirror array is aligned x Distance between the focusing lens and the aperture y Distance between the light emitting area and the optical axis y' Distance between the weak emission area image and the optical axis

Claims

1. A two-dimensionally distributed sample, a single condensing lens, a dichroic mirror array in which a plurality of dichroic mirrors are arranged, and an image sensor are arranged in this order along the optical axis of the condensing lens; The direction in which the plurality of dichroic mirrors are arranged is perpendicular to the optical axis, Light emitted from a measurement area on the sample and collected by the collecting lens is incident on the dichroic mirror array, and the incident light is divided by the dichroic mirror array into a plurality of light beams having different wavelength components; The image of the measurement area is divided into a plurality of images having different wavelength components on the image sensor and measured. In optical devices, An optical device, characterized in that an entrance of the dichroic mirror array, where the light first enters the dichroic mirror array, is closer to the image sensor than the focusing lens.

2. The optical device according to claim 1, An optical device, characterized in that there is no lens between the dichroic mirror array and the image sensor.

3. The optical device according to claim 1, the entrance is an aperture of the dichroic mirror array disposed within a stop; the aperture is disposed proximate to a side of the dichroic mirror array facing the focusing lens; 13. An optical device comprising: a first aperture having a width in a direction in which the dichroic mirrors are arranged, the width being smaller than an effective diameter of the focusing lens.

4. In the right-handed XYZ Cartesian coordinate system, A sample distributed two-dimensionally parallel to the YZ plane, a single focusing lens whose optical axis coincides with the X-axis, a dichroic mirror array in which m dichroic mirrors are arranged in parallel to each other in the Y-axis direction, where m is an integer equal to or greater than 2, and an image sensor parallel to the YZ plane are arranged in the above order along the positive direction of the X-axis, Light emitted from a measurement area on the sample and collected by the collecting lens is incident on the dichroic mirror array, and the incident light is divided by the dichroic mirror array into m light beams having different wavelength components; In an optical device for measuring an image of the measurement area by dividing the image into m images having different wavelength components on the image sensor, An aperture of the dichroic mirror array, through which the light is initially incident on the dichroic mirror array, is disposed in the aperture and adjacent to a side of the dichroic mirror array facing the focusing lens on the X-axis; Let h be the distance in the X-axis direction between the focusing lens and the image sensor, and x be the distance in the X-axis direction between the focusing lens and the aperture. [0010] An optical device characterized in that:

5. The optical device according to claim 4, An optical device, characterized in that there is no lens between the dichroic mirror array and the image sensor.

6. The optical device according to claim 4, Let D be the effective diameter of the focusing lens, and w be the width of the opening in the Y-axis direction. [0025] An optical device characterized in that:

7. The optical device according to claim 4, Let D be the effective diameter of the focusing lens, w be the width of the aperture in the Y-axis direction, and p be the average spacing between the m divided images. [0030] An optical device characterized in that:

8. The optical device according to claim 4, Let D be the effective diameter of the focusing lens, and w be the width of the opening in the Y-axis direction. [0045] An optical device characterized in that:

9. The optical device according to claim 4, Let D be the effective diameter of the focusing lens, w be the width of the aperture in the Y-axis direction, and p be the average spacing between the m divided images. [0050] An optical device characterized in that:

10. The optical device according to claim 4, The m dichroic mirrors are, in order from the negative direction to the positive direction of the Y axis, D1, D2, ..., Dm, the m dichroic mirrors have incident surfaces perpendicular to an XY plane, and the slope of a straight line obtained by projecting the normals of the m dichroic mirrors onto the XY plane is negative, The angle between the normal of the incidence surface of the m dichroic mirrors and the X-axis is θ 0 year, The refractive index of the substrate of the m dichroic mirrors is n 0 , the average width parallel to the XY plane and perpendicular to the normal to the incident surface is a, and the average width parallel to the XY plane and parallel to the normal to the incident surface is b. The dichroic mirror D1 is on the X-axis, When comparing the positions of two adjacent dichroic mirrors Dj and D(j+1) (where 1≦j≦(m-1)) on the XY plane, the Y coordinate of the dichroic mirror D(j+1) is larger, and the X coordinate of the dichroic mirror Dj is larger, The arrangement interval between the two adjacent dichroic mirrors D1 and D2 in the Y-axis direction is Δy 0 , the array spacing in the X-axis direction is Δx 0 year, When the average arrangement interval of the adjacent two dichroic mirrors Dj and D(j+1) (where 2≦j≦(m−1)) in the Y-axis direction is Δy and the average arrangement interval in the X-axis direction is Δx, In order to increase the width of the aperture in the Y-axis direction and reduce the optical path length of the dichroic mirror array, θ 0 , n 0 , a, b, Δy 0 , Δy, Δx 0 , Δx satisfy a predetermined relationship.

11. 11. The optical device according to claim 10, [006] An optical device characterized in that:

12. 11. The optical device according to claim 10, θ 2 = sin -1 (1 / n 0 ×sin(θ 0 )) when [0070] An optical device characterized in that:

13. In a right-handed XYZ orthogonal coordinate system, A sample is distributed two-dimensionally parallel to the YZ plane, and a single focusing lens whose optical axis coincides with the X axis. a dichroic mirror array in which m dichroic mirrors DA1, DA2, ..., DAm, where m is an integer of 2 or more, are arranged parallel to one another in order from the negative direction to the positive direction of a Y axis, and n dichroic mirrors DB1, DB2, ..., DBn, where n is an integer of 2 or more, are arranged parallel to one another in order from the positive direction to the negative direction of the Y axis; An image sensor parallel to the YZ plane, the sample, the dichroic mirror array, and the image sensor are arranged in the above order along the positive direction of the X-axis; Light emitted from a measurement area on the sample and collected by the collecting lens is incident on the dichroic mirror array, and the incident light is divided by the dichroic mirror array into (m+n-1) light beams having different wavelength components; (m+n-1) divided images having different wavelength components of the measurement area are formed on the image sensor and measured; an aperture of the dichroic mirror array, through which the light is initially incident on the dichroic mirror array, provided in a diaphragm, is disposed adjacent to a side of the dichroic mirror array facing the focusing lens on the X-axis; Let h be the distance in the X-axis direction between the focusing lens and the image sensor, and x be the distance in the X-axis direction between the focusing lens and the aperture. [0080] An optical device characterized in that:

14. 14. The optical device according to claim 13, the m dichroic mirrors and the n dichroic mirrors have incident surfaces perpendicular to an XY plane, the inclination of a straight line obtained by projecting a normal to the incident surfaces of the m dichroic mirrors onto the XY plane is negative, and the inclination of a straight line obtained by projecting a normal to the incident surfaces of the n dichroic mirrors onto the XY plane is positive, The angle that the normals of the incidence surfaces of the m dichroic mirrors and the n dichroic mirrors make with the X-axis is defined as θ 0 year, The refractive index of the base material of the m dichroic mirrors and the n dichroic mirrors is n 0 , the average width parallel to the XY plane and perpendicular to the normal to the incident surface is a, and the average width parallel to the XY plane and parallel to the normal to the incident surface is b. The two adjacent dichroic mirrors DA1 and DB1 are on the X-axis, and the X-coordinate of the dichroic mirror DB1 is greater than the X-coordinate of the dichroic mirror DA1; When comparing the positions of two adjacent dichroic mirrors DAj and DA(j+1) (where (1≦j≦(m-1))) on the XY plane, the Y coordinate of the dichroic mirror DA(j+1) is larger, and the X coordinate of the dichroic mirror DAj is larger. When comparing the positions of the two adjacent dichroic mirrors DBj and DB(j+1) (where (1≦j≦(n-1))) on the XY plane, the dichroic mirror DBj has larger Y and X coordinates. The average of the arrangement interval in the Y-axis direction between the two adjacent dichroic mirrors DA1 and DA2 and the arrangement interval in the Y-axis direction between the two adjacent dichroic mirrors DB1 and DB2 is Δy 0 The average of the arrangement interval in the X-axis direction of the two adjacent dichroic mirrors DA1 and DA2 and the arrangement interval in the X-axis direction of the two adjacent dichroic mirrors DB1 and DB2 is Δx 0 year, When the average arrangement interval in the Y-axis direction of the two adjacent dichroic mirrors DAj and DA(j+1) (where (2≦j≦(m-1))) and the average arrangement interval in the X-axis direction of the two adjacent dichroic mirrors DBj and DB(j+1) (where (2≦j≦(n-1))) is Δy and Δx, respectively, The aperture width of the dichroic mirror array in the Y-axis direction is enlarged, and the optical path length of the dichroic mirror array is shortened by adjusting the θ 0 , n 0 , a, b, Δy 0 , Δy, Δx 0 , Δx satisfy a predetermined relationship.

15. 15. The optical device according to claim 14, [0097] An optical device characterized in that:

16. 15. The optical device according to claim 14, θ 2 = sin -1 (1 / n 0 ×sin(θ 0 )) when [0089] An optical device characterized in that:

17. The optical device according to any one of claims 10 to 16, θ 0 = 45°.

Images