Measuring apparatus and measuring module

Abstract

To provide a measuring apparatus and a measuring module that can simplify a structure.SOLUTION: A measuring apparatus comprises: an interference filter 12; an imaging element 42 for receiving light transmitted through the interference filter 12; a posture adjustment mechanism 13 allowing a posture of the interference filter 12 to be manually changed; and a processing unit 6 which acquires image information for a plurality of frames obtained according to imaging using the imaging element 42, in a state that the posture of the interference filter 12 changes chronologically by the posture adjustment mechanism 13, and which specifies a posture parameter associated with a wavelength band that is targeted, based on correlation information indicating a correlation relationship between the posture parameter and a wavelength band of light transmitted through the interference filter 12, after associating the image information respectively for the plurality of frames with the posture information acquired in the same period as the acquisition time of the image information, following acquisition of the posture information indicating a plurality of posture parameters, and which further, extracts the image information associated with the posture information indicating the specified posture parameter.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a measurement device and a measurement module. [Background technology]

[0002] An optical module has been proposed that includes an imaging optical system that focuses light from an object on an imaging plane, a tunable interference filter that has a pair of opposing reflective films that receives light from the imaging optical system and emits light with a wavelength corresponding to the gap size between the pair of reflective films, and a light receiving unit that is disposed on the imaging plane of the imaging optical system and receives light from the object via the interference filter, where the interference filter is disposed so that its optical axis is tilted with respect to the optical axis of the imaging optical system (see Patent Document 1). This optical module can change the wavelength band of light that passes through the tunable interference filter by controlling the gap size between the pair of reflective films. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-15650 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the optical module described in Patent Document 1 has a complex structure of the wavelength tunable filter, and high precision is required in controlling the gap dimension between the pair of reflective films.

[0005] The present invention has been made in view of the above circumstances, and has an object to provide a measurement device and a measurement module that can simplify the structure. [Means for solving the problem]

[0006] In order to achieve the above object, a measuring device according to the present invention comprises: an optical system that forms an image of light emitted from the measurement object on an image plane; an interference filter that is interposed in the optical system, has a pair of reflective films facing each other, and when light emitted from the measurement object is incident, transmits light of a wavelength band that is set based on the distance between the pair of reflective films; an imaging element disposed on the imaging plane, for capturing an image formed on the imaging plane by receiving light emitted from the object to be measured and transmitted through the interference filter; an attitude adjustment mechanism that can manually change the angle between an optical axis of the optical system that intersects with the interference filter and a thickness direction of the interference filter; an image acquisition unit that acquires image information for a plurality of frames obtained by capturing images using the image sensor at a predetermined first sampling period while the attitude of the interference filter is changed over time by the attitude adjustment mechanism; an attitude information acquisition unit that acquires, at a second sampling period set in advance, attitude information indicating attitude parameters that reflect the attitudes of the plurality of interference filters while the attitudes of the interference filters are being changed over time by the attitude adjustment mechanism; an image association unit that, after acquiring the image information for a plurality of frames and a plurality of pieces of posture information, associates the image information with the posture information acquired at the same time as the acquisition of the image information; and an image selection unit that identifies the posture parameter corresponding to a target wavelength band based on correlation information indicating the relationship between the posture parameter and a wavelength band of light that passes through the interference filter when the interference filter is maintained in a posture reflected in the posture parameter, and selects the image information associated with the posture information indicating the identified posture parameter. [Effects of the Invention]

[0007] According to the present invention, the image matching unit acquires image information for multiple frames and multiple pieces of orientation information, and then matches the image information with orientation information acquired at the same time as the acquisition of the image information, and the image selection unit identifies orientation parameters corresponding to a target wavelength band based on correlation information indicating the correlation between the orientation parameters and the wavelength band of light transmitted through the interference filter, and selects image information associated with orientation information indicating the identified orientation parameters. This eliminates the need to maintain the orientation of the interference filter so that the wavelength band of light transmitted through the interference filter matches the target wavelength band, thereby simplifying the orientation adjustment mechanism for the interference filter and ultimately simplifying the structure of the measurement device. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic configuration diagram of a measurement device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a functional block diagram of a processing unit according to the embodiment. [Figure 3] 5A to 5C are diagrams illustrating the operation of the measuring device according to the embodiment. [Figure 4] 1 is a flowchart showing an example of the flow of a measurement method according to an embodiment. [Figure 5] FIG. 10 is a schematic diagram illustrating the configuration of a measurement device according to a modified example. [Figure 6] FIG. 10 is a functional block diagram of a processing unit according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] A measuring device according to an embodiment of the present invention will be described below with reference to the drawings. The measuring device according to this embodiment is used to measure the two-dimensional distribution of the intensity of each of light in multiple wavelength bands emitted from a measurement object. As shown in FIG. 1, the measuring device according to this embodiment includes a light source 5, an objective lens unit 2, a measurement module 1, an imaging device 4, and a processing unit 6. The light source 5 is, for example, a tungsten lamp or an LED (Light Emitting Diode) light source, and irradiates light toward the measurement object SP. Here, the measurement object SP is, for example, a light absorption biosensor chip that utilizes localized surface plasmon resonance (LSPR).

[0010] The objective lens unit 2 has a lens barrel 21 and a lens 22 disposed inside the lens barrel 21, and collimates the light emitted from the light source 5 and transmitted through the measurement object SP. As the lens 22, for example, a telecentric lens can be used.

[0011] The measurement module 1 includes a housing 11, an interference filter 12 disposed inside the housing 11, an attitude adjustment mechanism 13 that allows a user to manually adjust the attitude of the interference filter 12, and a linear sensor 14 disposed within the housing 11. The interference filter 12 is inserted into an optical system consisting of a lens 22 of the objective lens unit 2 and a lens 43 of the imaging device 4 (described later). The interference filter 12 has a pair of opposing reflective films (not shown). When light emitted from a measurement target SP is incident on the interference filter 12, the interference filter 12 transmits light of a wavelength band determined based on the distance between the pair of reflective films. The reflective film may be, for example, a metal film made of Ag or an Ag alloy, or a dielectric multilayer film formed by stacking TiO2 and SiO2 layers. The interference filter 12 transmits light of a different wavelength band depending on the angle θ1 between the optical axis J1 of the optical system formed by the lenses 22 and 43 and the thickness direction of the interference filter 12.

[0012] The attitude adjustment mechanism 13 can manually change the angle θ1 between an optical axis J1, which intersects with the interference filter 12 of the optical system formed by the lenses 22 and 43, and the thickness direction of the interference filter 12. The attitude adjustment mechanism 13 has a holding frame 131 that holds the interference filter 12 on the inside, a support shaft 132 that extends in a direction perpendicular to the optical axis J1 and rotatably supports the interference filter 12 at an end of the holding frame 131 on one side perpendicular to the thickness direction of the interference filter 12, and an operating lever 133 that is fixed to the interference filter 12 via the holding frame 131 and is operated by a user when the interference filter 12 is rotated around the support shaft 132. The angle θ1 between the optical axis J1 and the thickness direction of the interference filter 12 can be changed by the user operating the operating lever 133 as indicated by arrow AR1.

[0013] The linear sensor 14 has a plurality of light receiving elements arranged in a row, and is arranged so that reflected light from the interference filter 12 is incident on one of the plurality of light receiving elements via the lens 15. The light receiving element is, for example, a photodiode. The linear sensor 14 outputs information indicating the position of at least one light receiving element, of the plurality of light receiving elements, onto which reflected light from the interference filter 12 is incident, to the processing unit 6 as attitude information indicating an attitude parameter reflecting the attitude of the interference filter 12.

[0014] The imaging device 4 has a housing 41, an imaging element 42 disposed inside the housing 41, and a lens 43. The imaging element 42 is a solid-state imaging element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal-Oxide-Semiconductor) image sensor. The lens 43 forms an image on the imaging element 42 using light transmitted through the interference filter 12.

[0015] The processing unit 6 includes, for example, an MPU (Micro Processing Unit) and a memory. As shown in FIG. 2 , the processing unit 6 also includes an input unit 605 that is operated when the user starts measurement, and a display unit 604 on which the measurement results are displayed. The input unit 605 includes, for example, a measurement start button that the user presses when starting measurement, and a measurement end button that the user presses when ending measurement. When the measurement start button is pressed, the input unit 605 responsively acquires a measurement start notification signal and sends it to the trigger generating unit 613. When the measurement end button is pressed, the input unit 605 responsively outputs a measurement end notification signal to the trigger generating unit 613. The display unit 604 is, for example, a liquid crystal display device. In the processing unit 6, the MPU executes a pre-set program stored in memory to function as an image acquisition unit 611, a posture information acquisition unit 612, a trigger generation unit 613, an image matching unit 614, an image selection unit 615, and a display control unit 616.

[0016] The memory also includes an image storage unit 631 that stores, in chronological order, image information for multiple frames captured by the image sensor 42, and an attitude information storage unit 632 that stores, in chronological order, multiple pieces of attitude information indicating attitude parameters detected by the linear sensor 14. The memory also includes a period storage unit 633 that stores information indicating a predetermined first sampling period of the image information acquired by the image acquisition unit 611 and information indicating a predetermined second sampling period of the attitude information acquired by the attitude information acquisition unit 612, a correlation information storage unit 634 that stores correlation information indicating a correlation between the attitude parameters and the wavelength bands of light that transmit through the interference filter 12 when the interference filter 12 is maintained in an attitude reflected by the attitude parameters, and a selected image storage unit 635 that stores single-wavelength image information that indicates a two-dimensional distribution of light in at least one targeted wavelength band selected by the image selection unit 615. The memory also includes an image attitude information storage unit 636 that stores image information for each of different wavelength bands and attitude information in association with each other.

[0017] When the image acquisition unit 611 receives measurement start trigger information from the trigger generation unit 613, it accordingly starts acquiring image information input from the image sensor 42 at a first sampling period and stores the acquired image information in chronological order in the image storage unit 631. Furthermore, when the image acquisition unit 611 receives measurement end trigger information from the trigger generation unit 613, it accordingly stops acquiring image information. When the orientation information acquisition unit 612 receives trigger information from the trigger generation unit 613, it accordingly starts acquiring orientation information input from the linear sensor 14 at a second sampling period and stores the acquired orientation information in chronological order in the orientation information storage unit 632. Furthermore, when the orientation information acquisition unit 612 receives measurement end trigger information from the trigger generation unit 613, it accordingly stops acquiring orientation information.

[0018] When a measurement start notification signal is input from the input unit 605, the trigger generating unit 613 generates measurement start trigger information in response and notifies the image acquiring unit 611 and the posture information acquiring unit 612 simultaneously. On the other hand, when a measurement end notification signal is input from the input unit 605, the trigger generating unit 613 generates measurement end trigger information in response and notifies the image acquiring unit 611, the posture information acquiring unit 612, and the image correlating unit 614 simultaneously.

[0019] After acquiring multiple frames of image information and multiple pieces of posture information, the image association unit 614 refers to the period information stored in the period memory unit 633, and associates the image information with posture information acquired at the same time as the acquisition of the image information, and stores the associated image information in the image posture information memory unit 636. For example, as shown in Fig. 3, the image association unit 614 assumes that the image acquisition unit 611 continuously acquires image information at a first sampling period ΔT1, and the posture information acquisition unit 612 continuously acquires posture information at a second sampling period ΔT2. In this case, the image association unit 614 associates the image information with the posture information, assuming that the image information first acquired by the image acquisition unit 611 and stored in the image memory unit 631 and the posture information first acquired by the posture information acquisition unit 612 and stored in the posture information memory unit 632 were acquired at the measurement start trigger information occurrence time T[0]. Here, it is assumed that the second sampling period ΔT2 is N (N is a positive integer) times the first sampling period ΔT1, that is, N frames of image information are acquired during the second sampling period ΔT2. In this case, the image association unit 614 associates the M (M is a positive integer)-th acquired posture information with the M×N-th acquired image information.

[0020] 2, the image selection unit 615 identifies an attitude parameter corresponding to at least one target wavelength band based on the correlation information stored in the correlation information storage unit 634. The image selection unit 615 also selects at least one piece of image information associated with each piece of attitude information indicating the identified at least one attitude parameter from the image information stored in the image attitude information storage unit 636. The image selection unit 615 then stores the selected at least one piece of image information in the selected image storage unit 635.

[0021] The display control unit 616 forms an image for displaying the measurement results based on at least one image information item stored in the selected image storage unit 635 and displays the image on the display unit 604. Here, for example, the display control unit 616 uses multiple pieces of image information stored in the selected image storage unit 635 to identify the position of the pixel with the maximum intensity in multiple images corresponding to each of the multiple pieces of image information, and forms a so-called peak wavelength distribution image using the position information of the identified pixel for each of the multiple images. Alternatively, if the measurement object SP is a biosensor, the display control unit 616 identifies the pixel values ​​of multiple pixels constituting each of two images represented by image information corresponding to two wavelength bands selected based on the intended use of the biosensor, and calculates the intensity ratio as the ratio of the pixel values ​​of the identified multiple pixels. Then, the display control unit 616 forms an intensity ratio image showing the distribution of the calculated intensity ratio. Alternatively, the display control unit 616 aggregates the peak wavelength distribution image and the intensity ratio image for each pixel region corresponding to a predetermined portion of the measurement object SP, and forms an image showing the obtained numerical values ​​or an image graphing the numerical values.

[0022] Next, a method for measuring a two-dimensional distribution of light in a single wavelength region emitted from a measurement target SP using the measurement device according to this embodiment will be described with reference to FIG. 4. First, when a user presses the measurement start button on the input unit 605 (step S101), the image acquisition unit 611 of the processing unit 6 starts acquiring image information output from the image sensor 42, and the attitude information acquisition unit 612 starts acquiring attitude information output from the linear sensor 14 (step S102). Next, the user continuously moves the operation lever 133 (step S103). At this time, the image acquisition unit 611 acquires multiple frames of image information in a first sampling period while the attitude of the interference filter 12 changes over time as the operation lever 133 is moved. Furthermore, the attitude information acquisition unit 612 acquires multiple frames of attitude information in a second sampling period while the attitude of the interference filter 12 changes over time as the operation lever 133 is moved. Next, when the user presses the measurement end button of the input unit 605 (step S104), in response, the image acquisition unit 611 ends acquisition of image information, and the posture information acquisition unit 612 ends acquisition of posture information (step S105).

[0023] Thereafter, after acquiring image information for a plurality of frames and a plurality of pieces of orientation information, the image association unit 614 of the processing unit 6 refers to the period information stored in the period memory unit 633, associates the image information with orientation information acquired at the same time as the acquisition of the image information, and stores the associated image information in the image orientation information memory unit 636 (step S106). Next, the image selection unit 615 of the processing unit 6 identifies orientation parameters corresponding to at least one target wavelength band based on the correlation information stored in the correlation information memory unit 634, and selects at least one piece of image information associated with orientation information indicating the identified orientation parameter from the image information stored in the image orientation information memory unit 636, and stores the selected image information in the selected image memory unit 635 (step S107).

[0024] Next, the display control unit 616 of the processing unit 6 forms an image based on the image information stored in the selected image storage unit 635, and displays it on the display unit 604 (step S108). Here, the display control unit 616 forms the peak wavelength distribution image and the intensity ratio image described above, and displays them on the display unit 604.

[0025] As described above, according to the measurement device of this embodiment, the image matching unit 614 acquires multiple frames of image information and multiple pieces of attitude information, and then matches the image information with attitude information acquired at the same time as the acquisition of the image information, and the image selection unit 615 identifies attitude parameters corresponding to the target wavelength band based on correlation information indicating the correlation between the above-mentioned attitude parameters and the wavelength band of light transmitted through the interference filter 12, and selects image information associated with the attitude information indicating the identified attitude parameters. This eliminates the need to maintain the attitude of the interference filter 12 so that the wavelength band of light transmitted through the interference filter 12 matches the target wavelength band, thereby simplifying the attitude adjustment mechanism 13 for the interference filter 12 and ultimately simplifying the structure of the measurement device.

[0026] For example, methods for measuring the two-dimensional distribution of the intensity of light transmitted through a light absorption biosensor chip typically employ so-called spatial scanning measurement methods and wavelength scanning measurement methods using a spectroscopic camera. In the spatial scanning measurement method, the spectroscopic camera is moved horizontally while sequentially detecting light, which can result in long measurement times. On the other hand, wavelength scanning measurement methods typically utilize a bandpass filter with a variable wavelength of transmitted light. However, these bandpass filters often have a complex and expensive structure, which can lead to complex and expensive measurement devices. In addition, wavelength scanning measurement methods can use a bandpass filter with a fixed transmitted light wavelength band and a tilt control mechanism that controls the tilt of the bandpass filter, thereby controlling the transmitted light wavelength band by changing the tilt of the bandpass filter. However, this wavelength scanning measurement method requires highly accurate control of the tilt of the bandpass filter, which is difficult to achieve.

[0027] In contrast, the measurement device according to this embodiment can realize a so-called low-cost measurement device because it does not need to control the tilt of interference filter 12 with high precision and can simplify the structure of measurement module 1. Therefore, for example, it is relatively easy to realize a disposable test kit in which measurement module 1 is integrated with a biosensor chip, which is the measurement object SP.

[0028] Although the present invention has been described above with reference to an embodiment, it is not limited to the above embodiment. For example, as shown in FIG. 5, the measurement module 2001 may include a secondary optical system consisting of mirrors 2151 and 2152 and a lens 2153 for guiding reflected light from the interference filter 12 to the lens 43 of the image capture device 4. Note that in FIG. 5, the same components as those in the embodiment are denoted by the same reference numerals as in FIG. 1. The processing unit 2006 has the same hardware configuration as the processing unit 6 described in the embodiment. The MPU executes a preset program stored in memory, thereby functioning as an image acquisition unit 611, a posture information generation unit 2612, a trigger generation unit 613, an image matching unit 614, an image selection unit 615, and a display control unit 616, as shown in FIG. 6. Note that the same components as those in the embodiment are denoted by the same reference numerals as in FIG. 2.

[0029] The orientation information generation unit 2612 identifies the imaging position of the reflected light incident on the image sensor 42 via the aforementioned secondary optical system in the image indicated by the image information stored in the image storage unit 631. Then, the orientation information generation unit 2612 generates orientation information indicating the identified imaging position and stores it in the orientation information storage unit 632.

[0030] According to this configuration, the linear sensor 14 is not necessary, and therefore the structure of the measurement module 2001 can be simplified accordingly.

[0031] In the embodiment, an output unit (not shown) may be provided for outputting at least one piece of image information stored in selected image storage unit 635 to another analysis device. The output unit may include, for example, a connection terminal for storing at least one piece of image information stored in selected image storage unit 635 in an external recording medium such as a memory card.

[0032] Although the embodiments and modifications of the present invention have been described above, the present invention is not limited to these. The present invention includes any combination of the embodiments and modifications, and any combination to which appropriate modifications have been made. [Industrial Applicability]

[0033] The present invention is suitable as a test kit that utilizes light in multiple wavelength bands emitted from an object to be measured, or as a measurement device that has functions that can replace a spectroscopic camera. [Explanation of symbols]

[0034] 1: measurement module, 2: objective lens unit, 4: imaging device, 6: processing unit, 11, 41: housing, 12: interference filter, 13: attitude adjustment mechanism, 14: linear sensor, 21: lens barrel, 22, 43: lens, 42: imaging element, 131: holding frame, 132: support shaft, 133: operation lever, 604: display unit, 605: input unit, 611: image acquisition unit, 612: attitude information acquisition unit, 613: trigger generation unit, 614: image matching unit, 615: image selection unit, 616: display control unit, 631: image storage unit, 632: attitude information storage unit, 633: period storage unit, 634: correlation information storage unit, 635: selected image storage unit, 636: image attitude information storage unit, SP: measurement object, J1: optical axis

Claims

1. an optical system that forms an image of light emitted from the measurement object on an image forming plane; an interference filter that is interposed in the optical system, has a pair of reflective films facing each other, and when light emitted from the measurement object is incident, transmits light of a wavelength band that is set based on the distance between the pair of reflective films; an imaging element disposed on the imaging plane, for capturing an image formed on the imaging plane by receiving light emitted from the object to be measured and transmitted through the interference filter; an attitude adjustment mechanism that can manually change the angle between an optical axis of the optical system that intersects with the interference filter and a thickness direction of the interference filter; an image acquisition unit that acquires image information for a plurality of frames obtained by capturing images using the image sensor at a predetermined first sampling period while the attitude of the interference filter is changed over time by the attitude adjustment mechanism; an attitude information acquisition unit that acquires, at a predetermined second sampling period, attitude information indicating attitude parameters that reflect the attitudes of the plurality of interference filters while the attitudes of the interference filters are being changed over time by the attitude adjustment mechanism; an image association unit that, after acquiring the image information for a plurality of frames and a plurality of pieces of posture information, associates the image information with the posture information acquired at the same time as the acquisition of the image information; an image selection unit that identifies the posture parameter corresponding to a target wavelength band based on correlation information indicating a relationship between the posture parameter and a wavelength band of light that passes through the interference filter when the interference filter is maintained in a posture reflected in the posture parameter, and selects the image information associated with the posture information indicating the identified posture parameter, Measuring equipment.

2. a sensor including a plurality of light receiving elements arranged in a row, the sensor being arranged so that reflected light from the interference filter is incident on any one of the plurality of light receiving elements; the attitude information indicates a position of at least one light receiving element, among the plurality of light receiving elements, on which reflected light from the interference filter is incident; The measuring device according to claim 1 .

3. a secondary optical system that guides reflected light from the interference filter to the image sensor; the attitude information indicates an image formation position on the image sensor of the reflected light that is incident on the image sensor via the secondary optical system. The measuring device according to claim 1 .

4. The attitude adjustment mechanism includes: a support shaft that extends in a direction perpendicular to an optical axis of the optical system that intersects with the interference filter and that supports the interference filter so as to be freely rotatable; an operating lever fixed to the interference filter and operated by a user when the interference filter is turned around the support shaft; The measuring device according to any one of claims 1 to 3.

5. an interference filter that is inserted in an optical system that forms an image of light emitted from a measurement object on an image plane, has a pair of reflective films facing each other, and when light emitted from the measurement object is incident, transmits light of a wavelength band that is set based on the distance between the pair of reflective films; an imaging element disposed on the imaging plane, for capturing an image formed on the imaging plane by receiving light emitted from the object to be measured and transmitted through the interference filter; and an attitude adjustment mechanism that can manually change the angle between an optical axis of the optical system that intersects with the interference filter and a thickness direction of the interference filter. Measurement module.

Images