Measuring device and measuring method

Abstract

The high-speed object measuring device of the present invention comprises: a light irradiation unit that irradiates a moving object with light whose wavelength varies over time; and a camera unit that captures light from the object receiving light irradiated by the light irradiation unit and acquires wavelength information for each pixel; and the camera unit continuously acquires the time-varying wavelength.

Description

Measuring device and measuring method One aspect of this invention relates to a measuring device and a measuring method. Reference 1 describes a high-speed photography method capable of continuously photographing single phenomena changing within an ultra-short time range of sub-nanoseconds. Specifically, it describes a high-speed photography system that continuously illuminates an object with a plurality of flashes of different wavelengths. For the light from the object (the plurality of light beams of different wavelengths), while maintaining image information, each wavelength is spatially separated, and the separated light beams are incident on different positions on the light-receiving surface of an imaging element and detected. Based on this high-speed photography system, dynamic phenomena are measured using the image information of each detected light beam (each wavelength). [Prior Art Documents] [Patent Documents] Patent Document 1: Japanese Patent Application Publication No. 2015-41784 [The problem the invention aims to solve] Here, in the high-speed photography system described above, multiple lights of different wavelengths from the object are spatially separated for each wavelength. When using this method of light separation, the measurement of dynamic phenomena based on the image information of each detected light (each wavelength) is discrete rather than continuous. Therefore, there is a risk that the dynamic phenomena of the object cannot be measured with high precision. This invention was developed in view of the above-mentioned practical situation, and its purpose is to measure the dynamic phenomena of an object with high precision. [Technical Means for Solving the Problem] The present invention provides a measuring device comprising: a light irradiation unit that irradiates a moving object with light whose wavelength varies over time; and a camera unit that captures light from the object receiving light irradiated by the light irradiation unit and acquires wavelength information for each pixel; and the camera unit continuously acquires the time-varying wavelength. In the one-dimensional measurement device of the present invention, light with a wavelength that varies over time is irradiated onto a moving object, the light from the object is captured, and wavelength information is obtained for each pixel. Furthermore, in this measurement device, for light with a wavelength that varies over time, wavelength information is obtained for each pixel as is, rather than being spatially separated, thereby obtaining the temporal wavelength change continuously rather than discretely. Therefore, based on the changes in the obtained wavelength information, the location of the object at any given time can be estimated with high precision. As described above, the one-dimensional measurement device of the present invention can measure the dynamic phenomena of an object with high precision. Furthermore, in methods that spatially separate light whose wavelength varies over time and incident the separated light at different positions on the light-receiving surface of the camera unit, consideration is given to minimizing the dispersion of time (i.e., wavelength) through fine separation. However, in such methods, the finer the time separation, the larger the light-receiving area of ​​the camera unit must be, resulting in limitations on the number of frames, narrower field of view, or fewer pixels in the image. In other words, there is a trade-off between increasing the number of time separations to measure the dynamic phenomena of an object with high precision and reducing the light-receiving area, and previously, it was difficult to balance both. Regarding this point, as described above, the measuring device according to the present invention, since it detects wavelength information for each pixel as is, rather than spatially separating and detecting light whose wavelength varies over time, can measure the dynamic phenomena of an object with high precision without causing the problems caused by the aforementioned light-receiving area. The light irradiation unit can irradiate light whose wavelength changes at a period of one or more cycles within the exposure time of the aforementioned imaging unit. Based on this configuration, within one frame of the imaging unit, the dynamic phenomena of an object can be measured (stored) by measuring the time width of light whose wavelength changes over time. The illumination unit can be configured such that the optical axis of the light from the illumination unit to the object is orthogonal to the optical axis of the light from the object to the imaging unit. With this configuration, when the object moves in the same direction as the optical axis of the light from the illumination unit to the object, light can be irradiated onto a point on the object (e.g., an edge), and the wavelength change of the light from that point over time can be detected by different pixels in the imaging unit. That is, while avoiding light entering the same pixel multiple times, the dynamic phenomena of the object can be measured with high precision based on the detection results of each pixel. It is feasible to configure the light irradiation unit in such a way that the optical axis of the light from the light irradiation unit to the object and the optical axis of the light from the object to the imaging unit are obliquely intersected. The measuring device further includes a slot disposed on the optical axis of the light from the object to the imaging unit, and the area through which the light passes changes in response to the passage of time. In the case where the two optical axes are obliquely intersected, when light is irradiated onto the surface of a moving object, multiple light rays at different times may enter the same pixel. Regarding this point, by arranging a slot on the optical axis of the light from the object to the imaging unit, the area through which the light passes changes in response to the passage of time, thereby preventing multiple light rays at different times from entering the same pixel, and enabling high-precision measurement of the dynamic phenomena of the object even when light is irradiated onto the surface of a moving object. The light irradiation unit may include: a first irradiation unit that irradiates light within a first wavelength range, using the period of wavelength change as the first period; and a second irradiation unit that irradiates light within a second wavelength range, different from the first wavelength range, using the period of wavelength change as the second period, different from the first period. In this way, by irradiating the object with light of different wavelength ranges and different periods of wavelength change, the location of the object can be estimated based on the wavelength information of the two lights. Therefore, compared to estimation based on only one light, the time resolution can be improved, and the dynamic phenomena of the object can be measured with higher accuracy. The imaging unit may include: a first camera that captures light from an object receiving light from a first illumination unit; and a second camera that captures light from an object receiving light from a second illumination unit. With this configuration, information on the wavelengths of the two light sources can be captured by the two cameras respectively, and an image based on the changes in the wavelengths of the two light sources can be appropriately generated. This allows for more precise measurement of the dynamic phenomena of the object. The light irradiation section can have a white light source, and by optically selecting the wavelength of the white light, the wavelength can be made to change over time. Based on this configuration, light with a wavelength that changes over time can be generated with a simple setup. The light irradiation unit can have a pulsed light source, which disperses the wavelength of the pulsed light to make the wavelength change over time. Based on this configuration, light with a wavelength that changes over time can be generated with a simple setup. The camera unit may have a separating optical element that separates light from an object by transmitting or reflecting it according to wavelength. The width of the wavelength band, i.e., the edge shift width, which varies with wavelength, has a specific width. Light transmitted through the separating optical element is captured in a first imaging area, and light reflected through the separating optical element is captured in a second imaging area. With this configuration, light separated by the separating optical element, whose transmittance and reflectance vary with wavelength, can be captured separately, and the wavelength can be appropriately detected based on the individual imaging results. The present invention provides a method for measuring a state of matter, comprising the following steps: irradiating a moving object with light whose wavelength varies over time; capturing an image of the light received from the object, and acquiring wavelength information for each pixel; and continuously acquiring the temporal variation of the wavelength during the step of acquiring wavelength information. [Effects of the Invention] According to the measuring device and method of the present invention, the dynamic phenomena of an object can be measured with high precision. Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, the same or equivalent parts will be given the same reference numerals in each drawing, and repeated descriptions will be omitted. Figure 1 is a schematic diagram showing the high-speed object measuring device 1 of this embodiment. The high-speed object measuring device 1 measures the dynamic phenomena of the object 100 by irradiating a high-speed moving object (object 100) with light whose wavelength varies over time, capturing the light from the object 100, and recording the movement of the object 100 on a two-dimensional image. That is, in the high-speed object measuring device 1, by establishing a correspondence between time and wavelength for the irradiated light, when capturing the light from the object 100 and specifying the wavelength, it is possible to estimate the position of the object 100 at any given time, and thus measure the dynamic phenomena of the object 100. The object 100 may be, for example, a flying object or debris, and the dynamic phenomena of the object 100 may include, for example, the phenomenon of a flying object passing by or even bouncing back, or the phenomenon of multiple fragments scattering. As shown in Figure 1, the high-speed object measuring device 1 includes a camera system 2 and a control device 80. The camera system 2 includes a light irradiation unit 10 and an imaging unit 20 (image capture unit). Details of the camera system 2 will be described with reference to Figures 2 to 4. The light irradiation unit 10 is configured to irradiate a moving object 100 with light whose wavelength varies over time (wavelength sweep, wavelength scanning). In Figure 1, the wavelength variation of the light L emitted from the light irradiation unit 10 is displayed as a color difference over time. In the example of Figure 1, the wavelength variation of the light L is shown as a periodic fraction, with the initial wavelength L1 of the period being the shortest wavelength, gradually increasing in length, and the final wavelength L2 of the period being the longest wavelength. The light irradiation unit 10, as an example, irradiates light in the wavelength range of 600 nm to 700 nm, but is not limited to this; it can irradiate light in any wavelength range contained within, for example, the visible light wavelength range (380 nm to 780 nm). As shown in FIG. 1, the light irradiation unit 10 is arranged in a manner orthogonal to the optical axis (first optical axis) of the light from the light irradiation unit 10 to the object 100 and the optical axis (second optical axis) of the light from the object 100 to the imaging unit 20. Furthermore, the direction of the first optical axis is approximately the same as the direction of movement of the object 100. The first and second optical axes are orthogonal as long as they are orthogonal at any time during the period of irradiating the moving object 100. For example, the light irradiation unit 10 can, by continuously scanning light onto the object 100, trigger the imaging unit 20 at a specific time during the scanning, thereby synchronizing the exposure of the imaging unit 20 with the light whose wavelength varies over time. Alternatively, the light irradiation unit 10 can, by receiving a trigger from the imaging unit 20, begin scanning light whose wavelength varies over time, synchronously with the exposure of the imaging unit 20. The wavelength of light irradiated by the light irradiation unit 10 changes for more than one cycle within the exposure time of the imaging unit 20. Figure 2 is a schematic diagram of an example of the light illumination unit 10 included in the camera system 2. As shown in Figure 2, the light illumination unit 10 may, for example, include a pulsed light source 11 and a dispersion compensation module 12. The pulsed light source 11 is, for example, a femtosecond laser light source. Since femtosecond lasers have a wavelength width of several hundred nm, the pulsed light source 11 can be used to construct a wavelength scanning light source with a time width exceeding 200 ns. The dispersion compensation module 12 extends the broadband pulsed light emitted from the pulsed light source 11, imparting a different delay (difference in arrival time) for each wavelength. The dispersion compensation module 12 is constructed, for example, of highly dispersed optical fiber, which causes the wavelength to vary over time by dispersing the pulsed light. For example, in single-mode fiber, a delay of approximately 17 ps / nm occurs per wavelength per 1 km. In the highly dispersed optical fiber used for compensation, typically in a 100 km long-running fiber, a delay of approximately 1700 ps / nm can occur. In the two figures shown in Figure 2, the left side displays the state of the pulsed light emitted from the pulsed light source 11, and the right side displays the state of the light passing through the dispersion compensation module 12. In the two figures shown in Figure 2, the horizontal axis represents time, and the vertical axis represents luminance. In the right figure of Figure 2, for light L, the wavelength change over time is displayed as a difference in color. As shown in the right figure of Figure 2, the light emitted from the pulsed light source 11 passes through the dispersion compensation module 12, and the light has a time width, giving different delays to each wavelength. That is, the light passing through the dispersion compensation module 12 is light whose wavelength changes over time. In addition, high-brightness pulsed light at the picosecond level is converted into light with a wavelength width using a nonlinear effect, and the converted light is input into the dispersion compensation module 12, thereby obtaining light whose wavelength changes over time. The configuration of the light irradiation unit 10, which irradiates light with wavelengths varying over time, is not limited to the configuration shown in FIG2. For example, the light irradiation unit 10 may be configured to include a white light source and a plurality of bandpass filters arranged sequentially in space. In such a light irradiation unit 10, by moving and switching the plurality of bandpass filters, the wavelength of white light is optically selected to obtain light with wavelengths varying over time. Alternatively, the light irradiation unit 10 may be configured to include a white light source and a single bandpass filter. In such a light irradiation unit 10, by rotating, for example, a single bandpass filter, the wavelength of white light is optically selected to obtain light with wavelengths varying over time. Furthermore, the light irradiation unit 10 may be configured with a plurality of light irradiation units having different wavelengths of emitted light. In such a light irradiation unit 10, by switching the plurality of light irradiation units over time, light with wavelengths varying over time is obtained. When the object 100 has a certain reflectivity within the observation wavelength range, multiple light irradiation sections with different wavelengths simultaneously irradiate light. By continuously changing the ratio of their light intensity, light with wavelengths varying over time can be obtained. Furthermore, the light irradiation section 10 can be configured to include a white light source and a diaphragm. Referring back to Figure 1, the imaging unit 20 captures light from the object 100 that receives light from the illumination unit 10, and acquires wavelength information for each pixel. In addition to the usual image information, the imaging unit 20 also acquires wavelength information for each pixel. The imaging unit 20 continuously acquires the temporal changes in wavelength. Figure 3 is a schematic diagram showing the imaging unit 20 included in the camera system 2. As shown in Figure 3, the imaging unit 20 is configured to include an imaging element 21, an infinity correction lens 22, a tilting dichroic mirror 23 (separate optical element), a total reflection mirror 24, and an imaging lens 25. The infinity correction lens 22 is a collimating lens that converts light from the object 100 into parallel light. The infinity correction lens 22 performs aberration correction to obtain parallel light. The light output from the infinity correction lens 22 is incident on the tilted dichroic mirror 23. The tilted dichroic mirror 23 is a mirror made of special optical materials that separates light from the object 100 by transmitting or reflecting it according to its wavelength. The tilted dichroic mirror 23 reflects, for example, light of a specific wavelength and transmits light of other wavelengths. Figure 4 illustrates the characteristics of the tilted dichroic mirror 23. In Figure 4, the horizontal axis represents wavelength, and the vertical axis represents transmittance. As shown in Figure 4, the characteristics of the tilted dichroic mirror 23, in a specific wavelength band (wavelength λ), the tilted dichroic mirror 23... 1~λ Within the wavelength band of 2, the transmittance (and reflectance) of light changes gradually with the wavelength. In wavelength bands outside this specific wavelength band (i.e., wavelengths shorter than λ), the transmittance (and reflectance) changes more gently. 1 represents the lower wavelength side and the longer wavelength λ. 2. On the higher wavelength side, regardless of wavelength variation, the transmittance (and reflectance) of light are assumed to be constant. Since transmittance and reflectance are negatively correlated—if one increases, the other decreases—hereafter, it will sometimes be simply stated as "transmittance" rather than "transmittance (and reflectance)." Furthermore, "regardless of wavelength variation, the transmittance of light is constant" includes not only cases where it is completely constant, but also cases where, for example, the change in transmittance relative to a 1 nm wavelength change is less than 0.1%. At a higher wavelength λ... 1 represents the low-wavelength side; regardless of wavelength variations, the light transmittance is approximately 0%. At higher wavelengths, λ... 2 represents the high-wavelength side, where the light transmittance is approximately 100% regardless of wavelength variations. Furthermore, "light transmittance approximately 0%" includes transmittance of approximately 0% + 10%, while "light transmittance approximately 100%" includes transmittance of approximately 100% - 10%. Additionally, below, the width of the wavelength band where light transmittance changes with wavelength will sometimes be described as the "edge shift width." As described above, the tilted dichroic reflector 23 has a specific width (wavelength λ) for the width of the wavelength band where transmittance changes with wavelength. 1~λ Separate optical elements (width 2). The total reflection mirror 24 is an optical element that reflects the light reflected from the tilted dichroic mirror 23 toward the imaging lens 25. The imaging lens 25 images the light passing through the tilted dichroic mirror 23 and the light reflected in the tilted dichroic mirror 23 and further reflected in the total reflection mirror 24, and guides the light to the lens of the imaging element 21. The imaging element 21 captures light passing through the tilted dichroic mirror 23 in a first imaging area, and captures light reflected in the tilted dichroic mirror 23 and further reflected in the total reflection mirror 24 in a second imaging area different from the first imaging area. The imaging element 21 captures the light passing through the tilted dichroic mirror 23 and the light reflected in the total reflection mirror 24 by detecting the image formed by the imaging lens 25. The imaging element 21 is an imaging element used to capture light within a specific wavelength range, and is a region image sensor such as a CCD or MOS. Furthermore, the imaging element 21 can be composed of a linear sensor or a TDI (Time Delay Integration) sensor. In this embodiment, it is assumed that the imaging element 21 is a single imaging element having a first imaging area and a second imaging area, but the imaging element in the first imaging area and the imaging element in the second imaging area can be set separately (two sets can be set). In this case, two sets of imaging lenses are also provided corresponding to the imaging element. The imaging element 21 outputs the imaging result, i.e., the image, to the control device 80. Figure 5 shows an example of an image P1 captured. Image P1 displays an image DI of the dynamic phenomenon of object 100. In the image DI of the dynamic phenomenon, the movement of object 100 is displayed by changes in color (changes in wavelength). Since a correspondence between time and wavelength is established in advance for the irradiated light, when the wavelength is determined based on the image DI of the dynamic phenomenon, the position of object 100 at which time sequence it is located can be estimated, and the dynamic phenomenon of object 100 can be measured. Returning to Figure 1, the control device 80 is a computer, physically comprising memory such as RAM and ROM, a processor (processor circuit) such as a CPU, a communication interface, and storage units such as a hard disk. The control device 80 functions by executing programs stored in memory using the computer system's CPU. The control device 80 can be constructed from a microcomputer or an FPGA. The control device 80 calculates and outputs the wavelength (centroid of emission wavelength) based on the light intensity of each pixel in the image (each pixel of the image formed within the field of view) obtained in the camera system 2. The following is a detailed explanation of one example of the calculation principle for the centroid of emission wavelength. As described above, the tilted dichroic mirror 23 is positioned at a wavelength λ. 1 represents the reflection of all light on the lower wavelength side, at a higher wavelength λ. 2 allows all light to pass through the higher wavelength side, at wavelength λ. 1~λ The transmittance of light in the wavelength band 2 varies linearly with wavelength. In this case, it is related to the wavelength λ. 1. λ The relationship between the two is as follows: transmittance h(λ) is expressed by equation (1), and reflectance 1-h(λ) is expressed by equation (2). h(λ) = (λ-λ) / 2 1) / (λ 2-λ 1) (1) 1-h(λ)=(λ 2-λ) / (λ 2-λ 1) (2) Furthermore, it can be clearly stated that the wavelength λ with a reflectivity of 50% is... 50% It is expressed using the following equation (3). λ 50% =(λ 2+λ 1) / 2 (3) For a certain emission spectrum f(λ) located at λ 1 and λ Between 2, in the more λ 1 represents a shorter wavelength and a smaller λ. 2. When the wavelength is negligible at longer wavelengths (e.g., when the wavelength band of the emission spectrum f(λ) is limited by a bandpass filter (not shown), etc.), if we assume that the amount of reflected light is equal to the amount of transmitted light, then the following equation (4) holds. ∫f(λ)h(λ)dλ=∫f(λ)(1-h(λ))dλ (4) If equation (4) is transformed, it becomes the following equation (5). 2∫f(λ)h(λ)dλ=∫f(λ)dλ (5) If we substitute equation (1) into equation (5), then 2∫f(λ)(λ-λ) 1) / (λ 2-λ 1) dλ = ∫f(λ)dλ, and further, if we divide both sides by 2∫f(λ)dλ / (λ) 2-λ 1), then ∫f(λ)(λ-λ) 1) dλ / ∫f(λ)dλ= (λ 2-λ 1) / 2 ∫f(λ)λdλ / ∫f(λ)dλ= (λ 2+λ 1) / 2 (6). If we consider equation (3), it becomes clear that the right side of equation (6) is λ. 50%The left side is generally the centroid of any function, i.e., f(λ). Let the left side of equation (6) be λ. f Based on the above, for any arbitrary spectrum transmitted through a dichroic mirror with transmittance linearly tilted relative to wavelength, when the transmitted light and reflected light are equal, the centroid λ of the spectrum... f With λ 50% express. Furthermore, we consider the second emission spectrum g(λ). The entire spectrum of the emission spectrum g(λ) is contained within λ. 1 and λ Between 2. Currently, for the emission spectra f(λ) and g(λ), the difference between the transmitted and reflected light after normalization is calculated. Let the transmitted light of f(λ) be T. f Set the reflected light as R f Set the total light intensity to A. f Let D be the difference between transmitted light and reflected light. f Furthermore, let the transmitted light of g(λ) be T. g Set the reflected light as R g Set the total light intensity to A. g Let D be the difference between transmitted light and reflected light. g Furthermore, let the centroid of g(λ) be λ. g At this moment, T f R f T g R g The measured value is A. f A g D f D g These are values ​​that can be directly calculated from measured values. These values ​​can also be expressed using the following formulas: T f =∫f(λ)h(λ)dλ=∫f(λ)(λ-λ 1) / (λ 2 - λ 1)dλ (7) T g = ∫g(λ)h(λ)dλ = ∫g(λ)(λ - λ 1) / (λ 2 - λ 1)dλ (8) R f = ∫f(λ)(1 - h(λ))dλ = ∫f(λ)(λ 2 - λ) / (λ 2 - λ 1)dλ (9) R g = ∫g(λ)(1 - h(λ))dλ = ∫g(λ)(λ 2 - λ) / (λ 2 - λ 1)dλ (10) A f = ∫f(λ)dλ (11) A g = ∫g(λ)dλ (12) D f = T f - R f = 2 / (λ 2 - λ 1)*∫λf(λ)dλ - (λ 2 + λ 1) / (λ 2 - λ 1)*∫f(λ)dλ (13) D g = T g - R g = 2 / (λ 2 - λ 1)*∫λg(λ)dλ - (λ 2 + λ 1) / (λ 2 - λ 1)*∫g(λ)dλ (14) Here, by normalizing the difference between the transmitted light and the reflected light, it is equivalent to making D f Divide by A f D g Divide by A g If this arithmetic progression is set as R, then equation (15) holds true. R = D g / A g -D f / A f ={∫g(λ)λdλ / ∫g(λ)dλ-∫f(λ)λdλ / ∫f(λ)dλ}*2 / (λ 2-λ 1) =2(λ g -λ f ) / (λ 2-λ 1) (15) If the centroid of the wavelength of the emission spectrum f(λ) is λ f and the wavelength centroid λ of the emission spectrum g(λ) g Let the difference be δλ, then equations (16) and (17) below hold. R = 2δλ / (λ 2-λ 1) (16) δλ=R(λ 2-λ 1) / 2 (17) As above, it shows that the difference between the centroids of two arbitrary spectra f(λ) and g(λ) is obtained by calculation considering the amount of transmitted light and the amount of reflected light. Moreover, the centroid of f(λ) is λ. 50% At that time, since the amount of reflected light is equal to the amount of transmitted light, D f The value is 0. That is, the centroid of any spectrum g(λ) and wavelength λ is zero. g It is expressed using the following equation (18). λ g =δλ+λ 50% (18) Thus, the centroid of the emission spectrum can be calculated based on the filter design values, the amount of transmitted light, and the amount of reflected light. Based on the above principle, the wavelength of light incident on each pixel (centroid of emission wavelength) can be obtained with high precision. Moreover, by specifying the wavelength of light incident on each pixel, as described above, the location of the object 100 at any given time can be determined, and the dynamic phenomena of the object 100 can be measured. Secondly, the effects of this implementation will be explained. The high-speed object measuring device 1 of this embodiment includes: a light irradiation unit 10, which irradiates a moving object 100 with light whose wavelength varies over time; and an imaging unit 20, which captures the light received by the object 100 from the light irradiation unit 10, and acquires wavelength information for each pixel; and the imaging unit 20 continuously acquires the time-varying wavelength. In the high-speed object measuring device 1 of this embodiment, a moving object 100 is irradiated with light whose wavelength varies over time, the light from the object is captured, and wavelength information is obtained for each pixel. Furthermore, in this high-speed object measuring device 1, for light whose wavelength varies over time, wavelength information is obtained for each pixel as is, rather than being spatially separated and detected. This allows for the continuous rather than discrete acquisition of temporal wavelength changes. Based on the acquired changes in wavelength information, the position of the object 100 at any given time can be accurately estimated. As described above, the high-speed object measuring device 1 of this embodiment can measure the dynamic phenomena of the object 100 with high precision. Furthermore, in methods that spatially separate light whose wavelength varies over time and incident the separated light at different positions on the light-receiving surface of the camera unit, consideration is given to minimizing the dispersion of time (i.e., wavelength) through fine separation. However, in such methods, the finer the time separation, the larger the light-receiving area of ​​the camera unit must be, resulting in limitations on the number of frames, narrower field of view, or fewer pixels in the image. In other words, there is a trade-off between increasing the number of time separations to measure the dynamic phenomena of the object with high precision and reducing the light-receiving area, and previously, it was difficult to balance both. Regarding this point, as described above, the high-speed object measuring device 1 according to this embodiment obtains wavelength information for each pixel as is, rather than spatially separating and detecting light whose wavelength varies over time, thus enabling high-precision measurement of the dynamic phenomena of the object 100 without causing the problems caused by the aforementioned light-receiving area. The light irradiation unit 10 can irradiate light whose wavelength changes at a period of more than one cycle within the exposure time of the imaging unit 20. Based on this configuration, the dynamic phenomena of the object 100 can be measured (stored) within one frame of the imaging unit by measuring the time width of the light whose wavelength changes over time. The light irradiation unit 10 can be arranged in a manner orthogonal to the optical axis of the light from the light irradiation unit 100 to the object 100 and to the optical axis of the light from the object 100 to the imaging unit 20. With this configuration, when the object 100 moves in the same direction as the optical axis of the light from the light irradiation unit 100 to the object 100, light can be irradiated onto a point (e.g., an edge portion) of the object 100, and the wavelength change of the light from that point over time can be detected by different pixels in the imaging unit 20. That is, while avoiding light entering the same pixel multiple times, the dynamic phenomena of the object 100 can be measured with high precision based on the detection results of each pixel. The light irradiation unit 10 may have a white light source, and by optically selecting the wavelength of the white light, the wavelength changes over time. Based on this configuration, light with a wavelength that changes over time can be generated with a simple configuration. The light irradiation unit 10 may have a pulsed light source, which disperses the wavelength of the pulsed light to make the wavelength change over time. With this configuration, light with a wavelength that changes over time can be generated with a simple configuration. The camera unit 20 may include a tilted dichroic mirror 23, which separates light from the object 100 by transmitting or reflecting light according to wavelength. The width of the wavelength band, i.e., the edge shift width, which varies with wavelength, has a specific width. Light transmitted through the tilted dichroic mirror 23 is captured in a first camera area, and light reflected from the tilted dichroic mirror 23 is captured in a second camera area. With this configuration, light separated by the tilted dichroic mirror 23, whose transmittance and reflectance vary with wavelength, can be captured separately, and wavelength can be appropriately detected based on these imaging results. The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments. Hereinafter, variations 1 to 3, which differ from the above embodiments, will be described. Figure 6 schematically shows the camera system 2A of the high-speed object measuring device in the first variation example. The camera system 2A has two illumination units: a first illumination unit 10A and a second illumination unit 10B. The first illumination unit 10A illuminates light within a first wavelength range, using the period of wavelength change as the first period. The second illumination unit 10B illuminates light within a second wavelength range, different from the first wavelength range, using the period of wavelength change as the second period, which is different from the first period. Specifically, the first illumination unit 10A illuminates light within, for example, a wavelength range of 600 nm to 700 nm, using the period of wavelength change as the first period. The second illumination unit 10B illuminates light within, for example, a wavelength range of 400 nm to 500 nm, using the period of wavelength change as the second period. As described above, the first period and the second period are different from each other. For example, the first and second periods can be set as follows: while the first irradiation unit 10A scans light in the wavelength range of 600 nm to 700 nm once within one exposure time, the second irradiation unit 10B scans light in the wavelength range of 400 nm to 500 nm ten times within one exposure time. Furthermore, this is just one example; as long as the first and second periods are different, the individual periods are not limited to the above. Furthermore, the camera system 2A shown in Figure 6 has two cameras, a first camera 20A and a second camera 20B, as imaging units. The first camera 20A captures light from an object 100 that receives light from the first irradiation unit 10A. The second camera 20B captures light from the object 100 that receives light from the second irradiation unit 10B. Both cameras 20A and 20B can capture light within non-overlapping wavelength ranges. That is, the first camera 20A captures light irradiated by the first irradiation unit 10A, i.e., light with a wavelength range of 600 nm to 700 nm. For the first camera 20A, a bandpass filter can be set to not capture light outside this wavelength range. The second camera 20B captures light irradiated by the second irradiation unit 10B, i.e., light with a wavelength range of 400 nm to 500 nm. For the second camera 20B, a bandpass filter can be set to not capture light outside this wavelength range. This configuration improves the temporal resolution of measurements of the dynamic phenomena of the object 100. For example, in a configuration where the illumination unit and the imaging unit are each a single unit, the resolution within a single frame is approximately 1 / 100 due to factors such as the size of the camera's well, the shot noise limit, and readout noise. This is because the shot noise limit of the S / N ratio is the square root of the number of electrons in the well; if the image is sufficiently bright, the readout noise is negligible and below the shot noise level. Furthermore, since the well size of a camera used for measurement is typically tens of thousands of electrons, the actual image brightness is used at less than half of that to avoid image saturation. As a solution to exceed this limit, as shown in Figure 6, by illuminating the object 100 with light of different wavelength ranges at different wavelength variation periods (scanning wavelengths at different speeds), the location of the object can be determined based on the information from the wavelengths of the two lights, thus improving the temporal resolution. As described above, when the first irradiation unit 10A scans light in the wavelength range of 600 nm to 700 nm once in one exposure time, and the second irradiation unit 10B scans light in the wavelength range of 400 nm to 500 nm ten times in one exposure time, the time resolution can be increased by 10 times compared to the case where it is estimated based on only one light, and the dynamic phenomena of the object 100 can be measured with higher precision. Figure 7 schematically shows the camera system 2B of the high-speed object measuring device in the second variation. In the camera system 2B, the illumination unit 10 is arranged such that the optical axis (first optical axis) of the light from the illumination unit 10 to the object 100 and the optical axis (second optical axis) of the light from the object 100 to the imaging unit 20 are obliquely intersected. The oblique intersection of the first and second optical axes means that at any time during the illumination of the moving object 100, the first and second optical axes are obliquely intersected. Furthermore, the direction of the first optical axis is not the same as the direction of movement of the object 100. In the example shown in Figure 7, the object 100 moves in the horizontal direction, and the illumination unit 10 and the imaging unit 20 are both positioned above the object 100. When the first and second optical axes are obliquely intersecting, if light is shone onto the surface of a moving object 100, light rays at different times may enter the same pixel of the imaging element 21 of the imaging unit 20 that captures the light from the object 100. That is, light from multiple positions of the moving object 100 may sometimes overlap and enter the same pixel. In this case, it may be impossible to accurately obtain the timing of the object 100's movement, and the dynamic phenomena of the object 100 may not be measured with high precision. As a component for solving such a problem, the camera system 2B further includes: a slot 60 disposed on the optical axis (second optical axis) of the light from the object 100 to the imaging unit 20, and a lens 50 disposed between the slot 60 and the object 100. The area through which light passes through the slot 60 changes in response to the passage of time. Figure 8 is a schematic diagram showing the slot 60 included in the camera system 2B of Figure 7. Figure 8 is a top view of the slot 60. As shown in Figure 8, the slot 60 is generally circular in top view, and light-passing portions 60a are formed at specific intervals along the circumference of the slot 60. The area through which light passes through the slot 60 changes in response to the passage of time by rotating. The exposure time of the imaging unit 20 is set to be less than or equal to the time it takes for the slot 60 to rotate and advance one step (advance to the next light-passing portion 60a). Furthermore, the rotation of the slot 60 and the imaging unit 20 may be asynchronous. By setting such a slot 60, even when the first and second optical axes are obliquely intersecting (when light is irradiated onto the surface of the moving object 100), multiple time-series lights can be prevented from entering the same pixel, and the dynamic phenomena of the object 100 can be measured with high precision. So far, an example of irradiating a moving object 100 with light whose wavelength varies over time has been described. However, the high-speed object measuring device is not limited to this configuration. That is, the high-speed object measuring device may include: an illumination unit that irradiates a moving object 100 with light whose state varies over time; and an imaging unit that captures light from the object receiving light from the illumination unit, and acquires the state of light for each pixel; and the imaging unit continuously acquires the temporal changes in the state of light. Based on this configuration, the position of the object 100 at any given time can be accurately estimated based on the acquired state of light, and the dynamic phenomena of the object 100 can be measured with high precision. For example, the high-speed object measuring device includes: an illumination unit that irradiates a moving object 100 with light whose polarization direction varies over time; and an imaging unit that captures light from the object 100 receiving light from the illumination unit, and acquires the polarization direction for each pixel; and the imaging unit continuously acquires the temporal changes in the polarization direction. The following description, using this state as a third variation example, will be based on Figure 9. Figure 9 schematically shows the camera system 2C of the high-speed object measuring device in the third variation. The camera system 2C comprises a light source 210, a polarizer 230, and a half-wave plate 240 as a light irradiation unit. The light source 210 emits linearly polarized light. The half-wave plate 240 and the frame of the polarizing camera 220 rotate continuously in sync with the start of the measurement sequence. Thus, the polarization direction of the light irradiating the object 100 changes over time. That is, it can be configured to irradiate light with a separate polarization direction at each position of the moving object 100, and it can be determined at which point in the exposure sequence the object 100 is located. The camera system 2C includes a polarizing camera 220 as an imaging unit (image unit). The polarizing camera 220 is configured, for example, as a group of four pixels, with each of the four pixels having a polarizer that differs by 45°. Furthermore, the polarizing camera 220 determines the polarization direction of the light incident on that position—whether it is linear or elliptical polarization—based on the light intensity ratio of the four pixels. According to this configuration, based on the detected polarization direction, the location of the object 100 at any given time can be accurately estimated, allowing for high-precision measurement of the object 100's dynamic phenomena. Besides rotation of the half-wavelength plate, the rotation of the polarization direction can also utilize a liquid crystal device (LCOS) or a spatial light-changing element, or the Faraday effect can be used to change the intensity of the magnetic field applied to the Faraday element through illumination. 1: High-speed object measuring device (measuring device) 2, 2A, 2B, 2C: Camera system 10: Illumination unit 10A: First illumination unit 10B: Second illumination unit 11: Pulse light source 12: Dispersion compensation module 20: Imaging unit (camera unit) 20A: First camera 20B: Second camera 21: Imaging element 22: Infinity correction lens 23: Tilted dichroic mirror (separating optical element) 24: Total reflection mirror 25: Imaging lens 50: Lens 60: Slot 60a: Light transmission part 80: Control device 100: Object 210: Light source 220: Polarizing camera 230: Polarizing element 240: 1 / 2 wavelength plate L: Light L1, L2, λ 1,λ 2: Wavelength P1: Image X4: Characteristics of tilted dichroic mirrors Figure 1 is a schematic diagram showing a high-speed object measuring device according to an embodiment of the present invention. Figure 2 is a schematic diagram showing an example of the light irradiation unit included in the camera system of the high-speed object measuring device of Figure 1. Figure 3 is a schematic diagram showing an example of the imaging unit included in the camera system of the high-speed object measuring device of Figure 1. Figure 4 is a diagram illustrating the characteristics of a tilted dichroic reflector. Figure 5 is a diagram showing an example of a captured image. Figure 6 is a schematic diagram showing the camera system of the high-speed object measuring device according to a first variation. Figure 7 is a schematic diagram showing the camera system of the high-speed object measuring device according to a second variation. Figure 8 is a schematic diagram showing the slot included in the camera system of Figure 7. Figure 9 is a schematic diagram showing the camera system of the high-speed object measuring device according to a third variation. 1: High-speed object measuring device (measuring device) 2: Camera System 10:Light irradiation part 20: Camera Unit (Camera Section) 80: Control device 100: Object L: Light L1, L2: Wavelengths

Claims

1. A measuring device comprising: a light irradiation unit that irradiates a moving object with light of wavelength varying over time; and a camera unit that captures light from the object receiving light irradiated by the aforementioned light irradiation unit, and acquires wavelength information for each pixel; wherein the aforementioned camera unit continuously acquires the time-varying wavelength.

2. The measuring device of claim 1, wherein the wavelength of the light irradiation unit changes by more than one cycle within the exposure time of the imaging unit.

3. The measuring device of claim 1 or 2, wherein the aforementioned light irradiation unit is arranged such that the optical axis of the light from the aforementioned light irradiation unit to the aforementioned object is orthogonal to the optical axis of the light from the aforementioned object to the aforementioned imaging unit.

4. The measuring device of claim 1 or 2, wherein the aforementioned light irradiation unit is arranged such that the optical axis of the light from the aforementioned light irradiation unit to the aforementioned object is obliquely intersected with the optical axis of the light from the aforementioned object to the aforementioned imaging unit; and the aforementioned measuring device further includes a slot disposed on the optical axis of the light from the aforementioned object to the aforementioned imaging unit; the aforementioned slot is such that the area through which light passes changes in response to the passage of time.

5. The measuring device according to claim 1 or 2, wherein the aforementioned light irradiation unit comprises: a first irradiation unit that irradiates light in a first wavelength range by using the period of wavelength change as a first period; and a second irradiation unit that irradiates light in a second wavelength range different from the aforementioned first wavelength range by using the period of wavelength change as a second period different from the first period.

6. The measuring device of claim 5, wherein the aforementioned camera unit comprises: a first camera that captures light from the object that receives light irradiated by the aforementioned first irradiation unit; and a second camera that captures light from the object that receives light irradiated by the aforementioned second irradiation unit.

7. The measuring device of claim 1 or 2, wherein the aforementioned light irradiation section has a white light source, and the wavelength of the white light is optically selected so that the wavelength varies with time.

8. The measuring device of claim 1 or 2, wherein the aforementioned light irradiation section has a pulse light source, and the wavelength varies with time by dispersing the pulse light.

9. The measuring device according to claim 1 or 2, wherein the aforementioned camera unit comprises: a separating optical element that separates light from an object by transmitting or reflecting it according to wavelength, and the width of a wavelength band whose transmittance and reflectance vary according to the wavelength, i.e., the edge shift width has a specific width; and capturing light transmitted in the aforementioned separating optical element in a first camera area, and capturing light reflected in the aforementioned separating optical element in a second camera area.

10. A measurement method comprising the steps of: irradiating a moving object with light of a wavelength varying over time; and capturing light from the object that has received the light, and acquiring wavelength information for each pixel; and in the step of acquiring the wavelength information, continuously acquiring the temporal variation of the wavelength.

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