Measuring device and measuring method

Abstract

To provide a wave front measuring device and a wave front measuring method that can measure, with a simple configuration, wave fronts of rays of light with a plurality of wavelengths at the same time.SOLUTION: A wave front measuring device has: a light source unit that irradiates an object with irradiation light including rays of light with a plurality of wavelengths different from each other; a sensor that includes a plurality of types of pixels different from each other in spectral sensitivity; an optical system that forms spot images of the object on the sensor; and a calculation unit that calculates the positions of the spot images for the plurality of wavelengths by using a pixel value obtained from the pixels when the sensor is irradiated with the irradiation light through the object, and a conversion factor for converting the pixel value into the intensities of light for the plurality of wavelengths based on sensitivity for the plurality of wavelengths of the pixels.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a wavefront measuring device and a wavefront measuring method. [Background technology]

[0002] Conventionally, a method has been proposed to evaluate chromatic aberration using wavefronts measured by a wavefront sensor in order to evaluate the wavelength-dependent characteristics of an optical system. Patent Document 1 discloses a wavefront measuring device that measures the wavefronts of light for multiple wavelengths by separating the light incident on the wavefront sensor by wavelength in time or space. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2009-192411 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] In the wavefront measuring device described in Patent Document 1, the configuration becomes complex in order to simultaneously measure the wavefronts of light at multiple wavelengths.

[0005] The present invention aims to provide a wavefront measurement device and wavefront measurement method that can simultaneously measure the wavefronts of light at multiple wavelengths with a simple configuration. [Means for solving the problem]

[0006] As one aspect of the present invention TotalThe measuring device is characterized by comprising: a light source unit that irradiates an object with illumination light containing light of multiple different wavelengths; a sensor that includes multiple types of pixels with different spectral sensitivities; an optical system that forms a spot image of the object on the sensor; and a calculation unit that calculates the position of the spot image at multiple wavelengths using pixel values ​​obtained from the pixels when the illumination light is irradiated onto the sensor via the object, and conversion coefficients for converting the pixel values ​​into light intensity for each of the multiple wavelengths, based on the sensitivity of the pixels to each of the multiple wavelengths.

[0007] Furthermore, another aspect of the present invention is Total The measurement method includes the steps of: irradiating an object with illumination light containing light of multiple different wavelengths; forming a spot image of the illumination light on a sensor containing multiple types of pixels with different spectral sensitivities; and calculating the position of the spot image for multiple wavelengths using pixel values ​​obtained from the pixels when the illumination light is irradiated onto the sensor via the object, and conversion coefficients for converting the pixel values ​​into light intensity for each of the multiple wavelengths, based on the sensitivity of the pixels to each of the multiple wavelengths. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a wavefront measuring device and a wavefront measuring method that can simultaneously measure the wavefronts of light for multiple wavelengths with a simple configuration. [Brief explanation of the drawing]

[0009] [Figure 1] This is a configuration diagram of a wavefront measuring device according to an embodiment of the present invention. [Figure 2] This figure shows the spectral sensitivity of pixels in a color sensor. [Figure 3] This flowchart shows the method for calculating the wavefronts of light at multiple wavelengths in Example 1. [Figure 4] This flowchart shows the method for calculating the wavefronts of light at multiple wavelengths in Example 2. [Figure 5] This flowchart shows the method for calculating the wavefronts of light at multiple wavelengths in Example 3. [Figure 6] It is a flowchart showing a method for calculating the wavefronts of light for a plurality of wavelengths in Example 4.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same members are denoted by the same reference numerals, and duplicate descriptions are omitted.

[0011] FIG. 1 is a configuration diagram of a wavefront measurement apparatus 1 according to an embodiment of the present invention. The wavefront measurement apparatus 1 includes a light source unit 11, a wavefront sensor 12, and a calculation unit 13. In FIG. 1, a test object 14 is installed between the light source unit 11 and the wavefront sensor 12. Hereinafter, the case where the wavefront measurement apparatus 1 measures the transmitted wavefront of the test object 14 will be described.

[0012] The light source unit 11 irradiates an object with irradiation light including light of a plurality of different irradiation wavelengths. In the present embodiment, the light source unit 11 includes three light sources 11r, 11g, and 11b, and is configured such that the light from the three light sources 11r, 11g, and 11b is irradiated as one light. The light sources 11r, 11g, and 11b irradiate light having wavelengths λr (= 635 nm), λg (= 532 nm), and λb (= 450 nm), respectively. In the present embodiment, the light having wavelength λ is narrow-band light having a bandwidth of approximately 50 nm or less centered on wavelength λ.

[0013] Note that the irradiation wavelengths are not limited to wavelengths λr, λg, and λb, and may be, for example, wavelength λy (= 588 nm) or wavelength λb' (= 488 nm). Further, the number of irradiation wavelengths is not limited to three, and may be two or four or more.

[0014] Furthermore, in this embodiment, the light source unit 11 is configured to couple light from each light source using a fiber 111 to produce illumination light. The light source unit 11 may also be configured to align the optical paths of light from multiple light sources using a prism, a dichroic mirror, and a diffraction grating to produce illumination light. Alternatively, the light source unit 11 may be configured to produce illumination light by passing light from a white light source through a multiband filter that transmits only light of the illumination wavelength. Furthermore, the light source unit 11 may be configured to emit illumination light of a selectable wavelength. In addition, the light source unit 11 may be configured to emit light of only one wavelength when determining the reference position described later.

[0015] Light emitted from the light source 11 is incident on the wavefront sensor 12. In Figure 1, the light emitted from the light source 11 is incident on the test object 14 as diffused light, passes through the test object 14, and is incident on the wavefront sensor 12 as approximately parallel light. The light that has passed through the test object 14 has the wavefront aberration of the test object 14 added to it. Therefore, the wavefront aberration of the test object 14 can be determined by measuring the wavefront of the light that has passed through the test object 14.

[0016] Note that the configuration of the light source unit 11, wavefront sensor 12, and test object 14 shown in Figure 1 is an example and can be changed. For example, the test object 14 may be configured to receive parallel light or focused light. In addition, an optical system that changes the diameter of the light beam or an optical system that changes the degree of divergence or convergence of the light beam may be placed between the test object 14 and the wavefront sensor 12.

[0017] The wavefront sensor 12 comprises a microlens array 121 and a color sensor 122. The microlens array 121 is an element in which multiple microlenses are arranged in a two-dimensional array, and is positioned on the light-incident side of the color sensor 122 at a distance of approximately the focal length of the microlenses. Light incident on the wavefront sensor 12 is focused by each microlens of the microlens array 121, forming multiple spot images on the color sensor 122. The focusing position of each spot image changes according to the inclination of the incident wavefront at the position of each microlens. Therefore, the incident wavefront can be calculated by determining the focusing position of each spot image as its relative position to the focusing position (reference position) of each spot image when a known wavefront is incident. The reference position can be, for example, the focusing position of each spot image when a plane wave is incident, or the focusing position of each spot image when measuring a test object with known wavefront aberration.

[0018] The light of multiple wavelengths incident on the wavefront sensor 12 has different wavefronts for each wavelength due to chromatic aberration, etc., of the test object 14, and the inclination of the incident wavefront at the position of each microlens differs for each wavelength. Therefore, each spot image is an image of light with a different focal point for each wavelength. However, the shift in the focal point position for each wavelength in each spot image is usually small compared to the range of the intensity distribution of light for each wavelength, and each spot image is a state in which light of each wavelength overlaps.

[0019] The color sensor 122 is an image sensor in which multiple types of pixels with different spectral sensitivities are arranged in a two-dimensional array. In this embodiment, the color sensor 122 is an image sensor in which three types of pixels (R pixels, G pixels, and B pixels) are arranged in a Bayer array. Figure 2 is a diagram showing the spectral sensitivity of each pixel. The R pixels, G pixels, and B pixels have different spectral sensitivities. The R pixels are sensitive to wavelengths λr and λg, while the G pixels and B pixels are sensitive to wavelengths λr, λg, and λb. In this embodiment, the wavelengths in which sensitivity is defined as wavelengths that are approximately 5% or more of the maximum value of sensitivity to each wavelength included in the irradiated light.

[0020] The color sensor 122 is an image sensor in which at least one of several types of pixels is sensitive to at least two of several wavelengths included in the irradiated light. By using a color sensor 122 that includes such pixels, the selectivity of measurable wavelengths can be improved compared to using a color sensor equipped with a filter that transmits only specific wavelengths. For example, when using a color sensor 122 with spectral sensitivity as shown in Figure 2, it is possible to simultaneously irradiate with light of three wavelengths out of five wavelengths λr, λy, λg, λb', and λb and determine the wavefront of light at each wavelength.

[0021] Furthermore, in addition to R, G, and B pixels, the pixels may also include complementary color pixels (cyan, magenta, and yellow), white pixels that exhibit high spectral sensitivity across the entire visible light spectrum, and pixels sensitive to infrared and ultraviolet light. The number of pixel types is not limited to three; it may also be two, four, or more. However, to calculate the wavefronts of all wavelengths of light contained in the irradiated light, it is desirable that the number of pixel types be equal to or greater than the number of wavelengths of the irradiated light. It is also desirable that the pixels be sensitive to all wavelengths of the irradiated light. Moreover, it is desirable that all pixels be sensitive to multiple wavelengths of the irradiated light.

[0022] When light of multiple wavelengths is incident on the color sensor 122 simultaneously, the pixel value obtained at each pixel is obtained by multiplying the intensity of the spot image at each pixel by the spectral sensitivity of each pixel, and is expressed by the following equation (1).

[0023]

number

[0024] Here, C is the pixel value obtained from the pixel. cλ This is the sensitivity of the pixel to the wavelength λ. λn n is the intensity of the spot image at wavelength λ. n represents the pixel position.

[0025] The calculation unit 13 calculates the wavefronts of multiple wavelengths of light contained in the irradiated light from the pixel values ​​obtained by the wavefront sensor 12 and the spectral sensitivity of the pixels. [Examples]

[0026] Figure 3 is a flowchart showing the method by which the calculation unit 13 of this embodiment calculates the wavefronts of light for multiple wavelengths.

[0027] In step S11, the calculation unit 13 calculates interpolated pixel values ​​by interpolating the pixel values ​​of each pixel acquired by the color sensor 122. In the following description, the interpolated RGB pixel values ​​at each pixel position obtained by interpolating the pixel values ​​of the R, G, and B pixels will be denoted as R', G', and B', respectively.

[0028] In step S12, the calculation unit 13 calculates the intensity of light at wavelengths λr, λg, and λb at each pixel position. λn Calculate (n=r,g,b). Specifically, intensity I λn This is calculated using the interpolated pixel values ​​R', G', B' calculated in step S11 and a conversion coefficient for converting the interpolated pixel values ​​into the intensity of light at each wavelength, which is calculated based on the sensitivity of each pixel to each of the multiple irradiation wavelengths. In this embodiment, the calculation unit 13 calculates the representative value f of the sensitivity of the R pixel, G pixel, and B pixel to each of the wavelengths λr, λg, and λb. cλ Using (C=R,G,B λ=r,g,b) as the conversion coefficients, the intensity I is calculated using the following equation (2). λn Calculate.

[0029]

number

[0030] In this embodiment, the representative value f cλ The average spectral sensitivity of each pixel of the color sensor 122 is used as the spectral sensitivity. Alternatively, the median value or the spectral sensitivity of any single pixel may be used. Furthermore, it may be changed for each spot image, or, for example, the average value of the pixel range for which the centroid is calculated in step S13 described later may be used.

[0031] In step S13, the calculation unit 13 calculates the condensing position of the light of each wavelength for each spot image from the intensity of the light of each wavelength calculated in step S12. In the present embodiment, the calculation unit 13 uses, as the condensing position of the light of each wavelength, the center of gravity w iλ (=(w iλx ,w iλy )) of each wavelength of light, which is calculated using the following equations (3) and (4).

[0032]

Equation

[0033]

Equation

[0034] Here, the subscript i represents the spot image for which the center of gravity is calculated, and ni represents the position of the pixel used for the center of gravity calculation. Also, x and y each represent the coordinates in the x-axis direction and the y-axis direction, respectively. The x-axis and the y-axis are each defined along the direction in which the pixels are arranged in the color sensor 122.

[0035] In the present embodiment, the range of the pixels used for the center of gravity calculation is the region covered by the microlenses forming each spot image, but it may be changed as appropriate. Also, only the pixels whose pixel values are greater than or equal to a predetermined threshold value may be used for the center of gravity calculation. By not using the pixels with small pixel values for the center of gravity calculation, the acquisition error due to noise can be suppressed.

[0036] In step S14, the calculation unit 13 calculates the wavefront using the amount of movement dw i of the center of gravity w i calculated in step S13 with respect to the reference position. In the present embodiment, the condensing position when parallel light is incident on the wavefront sensor 12 is used as the reference position. The reference position is assumed to be calculated and stored in advance. The calculation unit 13 calculates the inclination in the x-axis direction and the y-axis direction of the wavefront S i of the light of wavelength λ using the amount of movement dω λ by the following equations (5) and (6).

[0037]

number

[0038]

number

[0039] Here, L is the distance between the microlens array 121 and the color sensor 122.

[0040] The calculation unit 13 calculates the wavefront S using equations (5) and (6). λ The wavefront of light at each wavelength is calculated by integrating the slope of the curve.

[0041] As described above, with the configuration of this embodiment, it is possible to calculate the wavefront of light for multiple wavelengths using multiple pixel values ​​obtained in a single image. In other words, it is possible to simultaneously measure the wavefront of light for multiple wavelengths with a simple configuration. Furthermore, if the irradiation wavelength is changed, the wavefront of light for each wavelength can be measured without changing the wavefront sensor 12 by changing the conversion coefficient used in the processing of step S12 to a conversion coefficient corresponding to the irradiation wavelength. [Examples]

[0042] Figure 4 is a flowchart showing the calculation method for calculating the wavefronts of light for multiple wavelengths by the calculation unit 13 of this embodiment. The method for calculating the wavefronts of light for multiple wavelengths in this embodiment differs from the calculation method of Embodiment 1 in the method for calculating the conversion coefficients for converting pixel values ​​into the intensity of light for each wavelength. In Embodiment 1, a common conversion coefficient is used for each pixel, but in this embodiment, different conversion coefficients are used for each pixel.

[0043] In step S21, the calculation unit 13 calculates an interpolated pixel value by interpolating the pixel value of each pixel acquired by the color sensor 122. In this embodiment, the calculation unit 13 calculates the interpolated pixel value using the interpolation coefficient km according to the following equation (7).

[0044]

number

[0045] Here, the subscript 'm' represents the position of the pixel used for interpolation, and the position of the pixel used for interpolation differs depending on the position of the pixel from which the interpolated pixel value is calculated.

[0046] In step S22, the calculation unit 13 calculates a conversion coefficient using the spectral sensitivity and interpolation coefficient of the pixel used for interpolation in step S21. The calculation unit 13 calculates the spectral sensitivity f of the color C pixel at position m. cλm Using the following equation (8), the transformation coefficient f' of the pixel at position n is obtained. cλn Calculate.

[0047]

number

[0048] In step S23, the calculation unit 13 uses the interpolated pixel values ​​calculated in step S21 and the conversion coefficients calculated in step S22 to calculate the intensity of light at each wavelength using the following equation (9).

[0049]

number

[0050] Since the processes in steps S24 and S25 are the same as those in steps S13 and S14 in Figure 3, a detailed explanation will be omitted.

[0051] In this embodiment, by calculating the conversion coefficient using the spectral sensitivity and interpolation coefficient of the pixels used for interpolation, it is possible to calculate the wavefront of light at each wavelength while suppressing errors due to variations in spectral sensitivity.

[0052] In this embodiment, the process in step S22 is executed after the process in step S21, but if the interpolation coefficients and the pixels used for interpolation are predetermined, it may be executed before the process in step S21. Alternatively, the conversion coefficients that have been calculated and saved in advance may be read out in step S23. In this embodiment, the conversion coefficients are calculated using the same coefficients as the interpolation coefficients, but different coefficients may be used. For example, the absolute value of the interpolation coefficients may be used, or a coefficient for calculating the conversion coefficients as the average value of the spectral sensitivity of the pixels used for interpolation may be used. [Examples]

[0053] Figure 5 is a flowchart showing the calculation method for calculating the wavefronts of light for multiple wavelengths by the calculation unit 13 of this embodiment. In this embodiment, the centroid of the pixel value for each color is calculated, and the centroid of the light for each wavelength is calculated using the centroid of the pixel value for each color. In other words, the method for calculating the focusing position of light for each wavelength differs from the calculation methods of Embodiments 1 and 2.

[0054] In step S31, the calculation unit 13 uses the pixel values ​​of each color to calculate the centroid W of the pixel values ​​of each color using the following equations (10) and (11). iC (=(W iCx ,W iCy Calculate )).

[0055]

number

[0056]

number

[0057] In each spot image, different pixels are used to calculate the centroid of the pixel values ​​for each color.

[0058] In step S31, the centroid of the pixel values ​​for each color is calculated using the pixel values ​​of each color, but it may also be calculated using the interpolated pixel values ​​of each color.

[0059] In step S32, the calculation unit 13 uses the centroid of the pixel values ​​of each color calculated in step S31 to calculate the centroid W of light of each wavelength using the following equations (12) and (13). iλ (=(W iλx ,W iλy Calculate )).

[0060]

number

[0061]

number

[0062] Here, N iC This is the centroid W of the pixel values ​​of color C. iC This is the number of pixels used when calculating F. Cλ This is a conversion coefficient from the pixel value of each color to the intensity of light at each wavelength, and is calculated as the inverse matrix of the spectral sensitivity matrix using the following equation (14).

[0063]

number

[0064] Equations (12) and (13) show the transformation coefficient F Cλ and the centroid W of the pixel values ​​of color C iC The centroid W is weighted by the product of the average pixel values ​​of the pixels used in its calculation. iC The centroid W of light at each wavelength is the weighted average of these. iλ This is the formula for calculating it.

[0065] In step S33, the calculation unit 13 calculates the wavefront of light for each wavelength, using the centroid of the light for each wavelength calculated in step S32 as the focusing position of the light for each wavelength.

[0066] In Examples 1 and 2, the conversion from color to wavelength is performed for each pixel, but in this example, the conversion is performed for each spot image, which reduces the amount of computation required to calculate the wavefront of light for each wavelength, thus speeding up processing and enabling more real-time measurement. [Examples]

[0067] Figure 6 is a flowchart showing the calculation method for calculating the wavefronts of multiple wavelengths of light by the calculation unit 13 of this embodiment. In this embodiment, the focal position of light of each wavelength is calculated using the spot image obtained when the reference position was calculated. Specifically, the focal position of each spot image when light of wavelengths included in the illumination light is sequentially irradiated one by one is calculated as the reference position. In addition, the intensity of light of each wavelength at each pixel is calculated from equation (1) using the pixel values ​​of each spot image. When light of wavelengths included in the illumination light is incident one by one, the brightness value of light of wavelengths other than the incident wavelength becomes 0, so the intensity of light of each wavelength at each pixel is calculated by dividing the obtained pixel value by the spectral sensitivity. The intensity distribution of light of each wavelength obtained in this way is retained as the reference image for each spot image.

[0068] In step S41, the calculation unit 13 calculates spot images by shifting the reference image of each spot image in the xy direction for each wavelength. The initial value of the shift amount is the distance from the reference position to the pixel position that gives the maximum pixel value at the pixel with the maximum spectral sensitivity of light for each wavelength.

[0069] In step S42, the calculation unit 13 calculates the pixel value of each pixel using the spectral sensitivity of each pixel from the spot image calculated in step S41, according to equation (1).

[0070] In step S43, the calculation unit 13 determines whether the pixel values ​​calculated in step S42 match the pixel values ​​obtained by the color sensor 122. In this embodiment, the calculation unit 13 calculates an evaluation value as the sum of the squares of the differences between the pixel values ​​of the spot image calculated in step S42 and the pixel values ​​of the spot image obtained by the color sensor 122. If this evaluation value is less than or equal to a separately defined reference value, it determines that the two spot images match. If it is determined that the pixel values ​​calculated in step S42 match the pixel values ​​obtained by the color sensor 122, the process proceeds to step S44; otherwise, it returns to step S41.

[0071] In step S44, the calculation unit 13 calculates the wavefront of light for each wavelength, using the shift amount of light for each wavelength as the focusing position of light for each wavelength.

[0072] Unlike Examples 1 and 2, this embodiment calculates the wavefront without converting the interpolated pixel values ​​obtained from the color sensor 122. Therefore, the wavefront of light at each wavelength can be calculated while eliminating the effects of interpolation errors.

[0073] This embodiment includes the following configurations and methods. (Configuration 1) A wavefront measuring device comprising: a light source unit that irradiates an object with irradiation light containing light of multiple wavelengths that are different from each other; a sensor that includes multiple types of pixels having different spectral sensitivities; an optical system that forms a spot image of the object on the sensor; and a calculation unit that calculates the position of the spot image for each of the multiple wavelengths using a pixel value obtained from the pixel when the irradiation light is irradiated onto the sensor via the object, and a conversion coefficient for converting the pixel value into the intensity of light for each of the multiple wavelengths, based on the sensitivity of the pixel to each of the multiple wavelengths. (Configuration 2) The wavefront measuring device according to Configuration 1, characterized in that at least one of the plurality of types of pixels is sensitive to at least two of the plurality of wavelengths. (Configuration 3) The wavefront measuring device according to Configuration 1 or 2, characterized in that the optical system forms a plurality of spot images of the object, and the conversion coefficient is calculated for each of the plurality of spot images based on the sensitivity of the pixels used to calculate the position of each of the plurality of spot images for each of the plurality of wavelengths to each of the plurality of wavelengths. (Configuration 4) The wavefront measuring device according to Configuration 1 or 2, characterized in that the calculation unit calculates the position of the spot image for each of the multiple wavelengths using the interpolated pixel values ​​of each color in the pixel obtained by interpolating the pixel values ​​and the conversion coefficients calculated for each of the multiple pixels based on the sensitivity of each of the multiple wavelengths for each of the multiple pixels used to calculate the interpolated pixel values. (Configuration 5) The wavefront measuring device according to Configuration 4, characterized in that the conversion coefficient is calculated for each of the plurality of pixels based on the interpolation coefficient used to calculate the interpolated pixel value and the sensitivity of each of the plurality of pixels to each of the plurality of wavelengths. (Configuration 6) The wavefront measuring device according to any one of Configurations 1 to 5, characterized in that the calculation unit calculates the centroid of the pixel values ​​of each color using the pixel values, and calculates the position of the spot image for each of the multiple wavelengths using the centroid of the pixel values ​​of each color and the conversion coefficient. (Configuration 7) The wavefront measuring device according to Configuration 1 or 2, characterized in that the calculation unit calculates the position of the spot image for each of the multiple wavelengths when the spot image for each of the multiple wavelengths is moved as a reference image when the spot image for each of the multiple wavelengths is sequentially irradiated, and the pixel value at the pixel calculated based on the sensitivity of the pixel to each of the multiple wavelengths matches the pixel value obtained from the pixel. (Configuration 8) The wavefront measuring device according to any one of Configurations 1 to 7, characterized in that the sensor includes R pixels, G pixels, and B pixels. (Configuration 9) The wavefront measuring device according to any one of Configurations 1 to 8, characterized in that the number of the plurality of wavelengths is equal to the number of types of pixels. (Configuration 10) The wavefront measuring device according to any one of Configurations 1 to 9, characterized in that the optical system is a microlens array in which a plurality of microlenses are arranged in two dimensions. (Method 1) A wavefront measurement method comprising the steps of: irradiating an object with illumination light containing light of multiple different wavelengths; forming a spot image of the illumination light on a sensor containing multiple types of pixels having different spectral sensitivities; and calculating the position of the spot image for each of the multiple wavelengths using a pixel value obtained from the pixel when the illumination light is irradiated onto the sensor via the object, and a conversion coefficient for converting the pixel value into the intensity of light for each of the multiple wavelengths, based on the sensitivity of the pixel to each of the multiple wavelengths.

[0074] Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of its gist. [Explanation of symbols]

[0075] 1. Wavefront measurement device 11 Light source section 13 Calculation Section 121 Microlens array (optical system) 122 Color Sensor (Sensor)

Claims

1. A light source unit that irradiates an object with light containing multiple wavelengths of light that are different from each other, A sensor containing multiple types of pixels with different spectral sensitivities, The sensor includes an optical system that forms a spot image of the object, A measuring device characterized by having a calculation unit that calculates the position of the spot image for each of the multiple wavelengths using a pixel value obtained from the pixel when the irradiated light is irradiated onto the sensor through the object, and a conversion coefficient for converting the pixel value into the intensity of light for each of the multiple wavelengths, based on the sensitivity of the pixel to each of the multiple wavelengths.

2. The measuring device according to claim 1, characterized in that at least one of the plurality of types of pixels is sensitive to at least two of the plurality of wavelengths.

3. The optical system forms multiple spot images of the object. The measuring device according to claim 1 or 2, characterized in that the conversion coefficient is calculated for each of the multiple spot images based on the sensitivity of the pixels used to calculate the position of each of the multiple spot images for each of the multiple wavelengths.

4. The measuring device according to claim 1 or 2, wherein the calculation unit calculates the position of the spot image for each of the multiple wavelengths using the interpolated pixel values ​​of each color in the pixel obtained by interpolating the pixel values, and the conversion coefficients calculated for each of the multiple pixels based on the sensitivity of each of the multiple pixels to each of the multiple wavelengths used to calculate the interpolated pixel values.

5. The measuring device according to claim 4, characterized in that the conversion coefficient is calculated for each of the plurality of pixels based on the interpolation coefficient used to calculate the interpolated pixel value and the sensitivity of each of the plurality of pixels to each of the plurality of wavelengths.

6. The measuring device according to claim 1 or 2, characterized in that the calculation unit calculates the centroid of the pixel values ​​of each color using the pixel values, and calculates the position of the spot image for each of the plurality of wavelengths using the centroid of the pixel values ​​of each color and the conversion coefficient.

7. The measuring device according to claim 1 or 2, wherein the calculation unit calculates the position of the spot image for each of the multiple wavelengths using the amount of movement of the reference image when the pixel value calculated based on the sensitivity of the pixel to each of the multiple wavelengths matches the pixel value obtained from the pixel when the spot image for each of the multiple wavelengths is moved as a reference image when the spot image for each of the multiple wavelengths is sequentially irradiated with light of each of the multiple wavelengths.

8. The measuring device according to claim 1 or 2, characterized in that the sensor includes R pixels, G pixels, and B pixels.

9. The measuring device according to claim 1 or 2, characterized in that the number of the plurality of wavelengths is equal to the number of types of pixels.

10. The measuring device according to claim 1 or 2, characterized in that the optical system is a microlens array in which a plurality of microlenses are arranged in a two-dimensional manner.

11. The steps include: irradiating an object with light containing multiple wavelengths of light that are different from each other, The steps include forming a spot image of the irradiated light on a sensor that includes multiple types of pixels with different spectral sensitivities, A measurement method comprising the step of calculating the position of the spot image for each of the multiple wavelengths using a pixel value obtained from the pixel when the irradiated light is irradiated onto the sensor through the object, and a conversion coefficient for converting the pixel value into the intensity of light for each of the multiple wavelengths, based on the sensitivity of the pixel to each of the multiple wavelengths.

Images