Processing apparatus, optical measurement apparatus, optical measurement method, and optical measurement program

Abstract

To provide a processing apparatus that projects rays of light with a plurality of wavelengths on an object, and acquires images of the object from detection signals with respective light intensities.SOLUTION: According to an embodiment, a processing apparatus has a processing unit that projects, toward an object, a plurality of rays of projection light different from each other including a plurality of wavelengths different from each other, in a stage for processing, for every signal, intensity values of the rays of light with the plurality of wavelengths from the object caused by the projection of the plurality of rays of projection light, acquires the plurality of wavelengths as detection signals not having information on positions, performs transform processing on numerical values by using parameters independent for every wavelength from the intensity values of the detection signals, takes a result as first conversion signals corresponding respectively to the plurality of wavelengths, and acquires an image of the object on the basis of the first conversion signals corresponding to the plurality of wavelengths and signals related to the plurality of rays of projection light.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] Embodiments of the present invention relate to a processing device, an optical measurement device, an optical measurement method, and an optical measurement program.

Background Art

[0002] Ghost imaging (hereinafter referred to as GI) has high detection sensitivity but generally takes a long time for measurement. Therefore, when rapid measurement is required, such as real-time inspection of an object, speeding up GI is an issue. As a countermeasure for speeding up GI, utilization of GI that simultaneously acquires signals for multiple wavelengths can be mentioned.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Non-Patent Documents

[0004]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The problem to be solved by the present invention is to provide a processing device, an optical measurement device, an optical measurement method, and an optical measurement program that project light of a plurality of wavelengths onto an object and acquire an image of the object from detection signals of respective light intensities.

Means for Solving the Problem

[0006] According to an embodiment, a processing device projects a plurality of different projection lights each including a plurality of different wavelengths toward an object, and intensity values of light of a plurality of wavelengths from the object due to each projection of the plurality of projection lights are respectively acquired as detection signals having no information regarding position of the plurality of wavelengths at a stage of respectively processing the signals, numerical values are subjected to conversion processing using parameters independent for each wavelength with respect to the intensity values of the detection signals, this is used as a first conversion signal corresponding to each of the plurality of wavelengths, and an image of the object is acquired based on the first conversion signals corresponding to the plurality of wavelengths and signals regarding the plurality of projection lights. The processing device has a processing unit.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0008] Hereinafter, the optical measurement apparatus 10 according to the present embodiment will be described with reference to the drawings. The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the ratio of the sizes between parts, etc. are not necessarily the same as those in reality. Also, even when representing the same part, the dimensions and ratios may be represented differently in the drawings. Regarding the already described content, detailed descriptions will be omitted as appropriate.

[0009] In the present embodiment, light is defined as an electromagnetic wave. Light is, for example, visible light, X-rays, ultraviolet rays, infrared rays, near-infrared rays, far-infrared rays, microwaves. The light source of the illumination unit 12 may be one that emits any of, for example, visible light, ultraviolet rays, and infrared rays. Visible light is light having a wavelength of, for example, 420 nm or more and 760 nm or less.

[0010] FIG. 1 shows a configuration diagram of an optical measurement apparatus 10 for ghost imaging (hereinafter referred to as GI) according to the present embodiment.

[0011] As shown in FIG. 1, the GI of the optical measurement apparatus 10 according to the present embodiment projects a plurality of two-dimensional pattern lights Ε αnk onto a sample (object) S, and the two-dimensional pattern light Ε αnkAn optical element (lens) 14 that passes the transmitted light or the reflected light from the sample S when projected onto the sample S, a detector 16 that detects the intensity of the transmitted light or the reflected light that has passed through the optical element 14, and a processing device (optical processing device) 18 that processes signals.

[0012] The light source of the illumination unit 12 is, for example, an LED (Light-emitting diode). Note that a projector may be used as the illumination unit 12.

[0013] The illumination unit 12 irradiates the surface of the sample S with two-dimensional pattern light. The illumination unit 12 can emit a plurality of light rays having different wavelengths from each other. In the present embodiment, the illumination unit 12 can emit light rays of at least two wavelengths (for example, a first light ray having a first wavelength, a second light ray having a second wavelength, and a third light ray having a third wavelength). In one example, the first wavelength is, for example, 450 nm (blue light), the second wavelength is, for example, 650 nm (red light), and the third wavelength is, for example, 550 nm (green light). In the present embodiment, the illumination unit 12 can simultaneously project illumination light of three wavelengths (the first wavelength, the second wavelength, the third wavelength) onto the sample S. The illumination light projected by the illumination unit 12 is pattern light having a two-dimensional pattern. Here, the two-dimensional pattern (pattern light) of the illumination light is light having a distribution of intensities that varies depending on the position in a cross-section orthogonal or substantially orthogonal to the propagation direction of the illumination light. That is, the two-dimensional pattern of the illumination light has a spatial intensity distribution. The pattern light projected by the illumination unit 12 includes at least two of light having different first wavelengths W1, light having a second wavelength W2, and light having a third wavelength W3, and has different patterns from each other.

[0014] As shown in FIG. 1, the illumination unit 12 sequentially projects, for example, two or more two-dimensional pattern lights onto the sample S. After projecting the first pattern light PR1 onto the sample S, the illumination unit 12 sequentially projects the second pattern light PR2, the third pattern light PR3, …, the nth pattern light PRn (n is a natural number of 2 or more) onto the sample S. The first pattern light PR1 to the nth pattern light PRn are not correlated with each other. Here, n is preferably 3 or more.

[0015] The optical element (lens) 14 images or condenses, for example, the transmitted light of the sample S or the reflected light from the sample S onto the detector 16.

[0016] The GI of the optical measurement device 10 sequentially projects two-dimensional patterns (pattern lights PR1, PR2, … PRn) each including a plurality of wavelengths W1, W2, W3 onto the sample S, and the detector 16 having spectroscopic performance detects the signal intensities of a plurality of wavelengths n times respectively. Hereinafter, this is called multi-wavelength GI. With this multi-wavelength GI, the number of detections per detection increases by the number of superimposed wavelengths according to the number of spectroscopic performances, and the measurement time of GI is shortened compared to single-wavelength GI.

[0017] In the optical measurement device 10 according to this embodiment, for example, a single pixel detector is used as the detector 16. The single pixel detector 16 here refers to a detector that can detect light of at least two different wavelengths as detection signals and does not have information regarding position at the stage of processing the detection signals. For example, a single detector such as a photodetector or a photomultiplier tube corresponds to this. The single pixel detector 16 according to this embodiment can receive intensity values of light of a plurality of wavelengths from the sample S by projecting each of a plurality of two-dimensional pattern lights (projected lights) including at least two different wavelengths projected toward the sample (object) S. The processing device 18 causes each of them to be acquired as a set of detection signals having no information regarding position at the stage of processing the signals, with respect to at least two different wavelengths. An example of a set of detection signals is the light intensity values of R, G, and B. Therefore, in this embodiment, the detector 16 can acquire, as detection signals, a set of light intensity values of R, G, and B as at least two different wavelengths.

[0018] Also, in the general spectroscope 116 shown in FIG. 2, a plurality of detectors 116a, 116b, and 116c are arranged inside the device (inside the spectroscope 116). The spectroscope 116 can detect light of at least two different wavelengths as detection signals. Since the plurality of detectors 116a, 116b, and 116c of the spectroscope 116 do not have information regarding position at the stage of signal processing by the processing device 18, this can also be regarded as one of the single pixel detectors.

[0019] Similarly, FIG. 3 shows an image sensor 216 (color camera) in which a number of pixels are arranged in a predetermined order. An example of the image sensor 216 is a CMOS, a CCD, or the like. The image sensor 216 can detect light of at least two different wavelengths as detection signals at each pixel. Even when the processing device 18 extracts one pixel in the image sensor 216 shown in FIG. 3 and uses the signal acquired by that one pixel for processing, that pixel (one pixel) 216a can be processed as not including information on the array (Bayer array) of color filters of the image sensor 216. For this reason, when the processing device 18 extracts and uses one pixel 216a in the image sensor 216, the image sensor 216 can be regarded as one of the single pixel detectors.

[0020] Furthermore, FIG. 4 shows an image sensor 316 (color camera) in which a number of pixels are arranged in a predetermined order. An example of the image sensor 316 is a monochrome camera or a color camera. The image sensor 316 can detect light of at least two different wavelengths as detection signals. Also, with respect to a spatial imaging device such as the image sensor (monochrome camera or color camera) 316 shown in FIG. 4, the processing device 18 can calculate the sum of the light intensity values of all the pixels at the signal processing stage, and when processing the information acquired by this image sensor 316, it can be processed as not having information regarding position. In this case, the image sensor 316 can be treated as one of the single pixel detectors.

[0021] Hereinafter, the processing device 18 will be described. The processing device 18 can control the light source of the illumination unit 12 and the detector 16. Also, the processing device 18 can perform various operations based on signals regarding a plurality of two-dimensional pattern lights (projected lights) emitted from the illumination unit 12 and signals input from the detector 16.

[0022] The processing device 18 is composed of, for example, a computer or the like, and includes a processor (processing unit) and a storage medium. The processor includes any one of a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), a microcomputer, an FPGA (Field Programmable Gate Array), a DSP (Digital Signal Processor), and the like. The storage medium may include a non-temporary auxiliary storage device in addition to a main storage device such as a memory. Examples of the storage medium include an HDD (Hard Disk Drive), an SSD (Solid State Drive), a magnetic disk, an optical disk (CD-ROM, CD-R, DVD, etc.), a magneto-optical disk (MO, etc.), and a non-volatile memory such as a semiconductor memory that can be written to and read from at any time.

[0023] In the processing device 18, only one or a plurality of each of the processor and the storage medium may be provided. In the processing device 18, the processor performs processing by executing a program or the like stored in the storage medium or the like. Further, the program executed by the processor of the processing device 18 may be stored in a computer (server) connected to the processing device 18 via a network such as the Internet, or a server in a cloud environment. In this case, the processor downloads the program via the network.

[0024] In the processing device 18, various calculation processes based on the signal acquisition from the detector 16, the signal acquired from the detector 16, and the signals related to the plurality of two-dimensional pattern lights (projection lights) from the illumination unit 12 are executed by a processor or the like, and the storage medium functions as a data storage unit.

[0025] Further, at least a part of the processing by the processing device 18 may be executed by a cloud server configured in a cloud environment. The infrastructure of the cloud environment is configured by virtual processors such as virtual CPUs and cloud memory. In one example, signal acquisition from the detector 16, signals acquired from the detector 16, and various calculation processes based on signals related to a plurality of two-dimensional pattern lights (projection lights) from the illumination unit 12 are executed by the virtual processor, and the cloud memory functions as a data storage unit.

[0026] Here, for the following description, several variables are defined. In the multi-wavelength GI of the optical measurement device 10 according to the present embodiment, the processing device 18 controls the light source of the illumination unit 12 and irradiates the sample S with two-dimensional pattern lights (projection lights) having no correlation from the illumination unit 12, that is, while changing the two-dimensional pattern lights, the detector 16 measures the intensity value for each two-dimensional pattern light. Let the total number of such measurements be N. Also, let the random pattern of the two-dimensional pattern light projected from the illumination unit 12 at the n-th measurement be Ε αnk Let the subscript α correspond to the wavelength and k correspond to each pixel of the two-dimensional pattern. Let the reflectance of the sample be ρ αk and let the signal intensity detected by the detector 16 at the n-th time be Β αn This signal (detected signal intensity) Β αn is used for the normalization process (first conversion process) described later.

[0027] Note that the processing device 18 synchronizes the detection of the signal intensity Β αnk of the detector 16 with respect to the irradiation of a certain two-dimensional pattern light Ε αn And the processing device 18 detects the signal intensity Β αnk of the detector 16 with respect to the irradiation of each two-dimensional pattern light Ε αn The processing device 18 receives from the illumination unit 12 what kind of two-dimensional pattern light Ε αnk has been projected. This signal (two-dimensional pattern light) Ε αnk is used for the normalization process (second conversion process) described later.

[0028] For a general function Ax that depends on the variable x,<ax>x represents the average with respect to the variable x of Ax. Specifically, when the variable x takes on the values of a total of X, such as x = x1, x2, x3, …, x X it can be expressed as in Equation (1).

[0029]

Equation

[0030] First, Figure 5 shows the projection pattern light Ε using a random pattern including three wavelengths (W1, W2, W3) for the sample S αnk when projected, the signal intensity Β acquired by the detector 16 at the multi-wavelength GI αn example, and the signal intensity Β αn obtained from the example of this signal intensity Β αn histogram. As can be seen from Figure 5, generally the detected signal intensity Β αn and the signal histogram have different distributions for each wavelength. This is because the detected signal intensity Β αn has a correlation with the wavelength due to the wavelength characteristics of the light receiving elements of the illumination unit 12 and the detector 16. When reconstructing an image at the multi-wavelength GI, in order to effectively utilize all the signal intensities Β αn it is necessary to handle the signal intensities Β αn of each of these wavelengths in an uncorrelated and equivalent manner. Therefore, even if the same image reconstruction process as the conventional single-wavelength GI as described below is applied to the detected signal intensity Β αn of the multi-wavelength GI, generally the image of the sample (object) S cannot be reconstructed.

[0031] Note that the symbol Δ in the following Equations (2), (3), (4), etc. represents taking the difference of each signal.

[0032] Equation (2) is for the signal intensity Β αn in each detection round, taking the difference between the signal intensity Β αn in each detection round and the average value of the signal intensity Β αn in each detection round.

[0033]

Equation

[0034] Equation (3) takes the difference between the two-dimensional pattern light Ε corresponding to each detection time and the average value of the two-dimensional pattern light Ε at each detection time. αnk Regarding the two-dimensional pattern light Ε at each detection time, αnk and the two-dimensional pattern light Ε of each detection time αnk

[0035]

Number

[0036] Equation (4) is an equation for obtaining the reconstructed image G of the sample S of the conventional single-wavelength GI.

[0037]

Number

[0038] In addition, in Equation (4), in the conventional single-wavelength GI, a two-dimensional pattern light (projection pattern) is projected onto the sample S, and the intensity of the transmitted or reflected light is detected by a single light-receiving element. Then, the correlation with the two-dimensional pattern light (projection pattern) corresponding to the signal at each time is calculated to reconstruct the image of the sample S.

[0039] As described above, since the signal intensity Β generally has a correlation with the wavelength, generally, even if Equation (4) is applied with multi-wavelength GI, the image of the sample (object) S cannot be reconstructed. This indicates that C is a proportionality coefficient that does not depend on the position k or the wavelength α, as shown in the following Equation (5). αn

[0040]

Number

[0041] ​​That is, when the same image reconstruction process as that of the conventional single-wavelength GI is applied to the multi-wavelength GI, the function G related to the image reconstruction process does not result in being proportional to the reflectance ρ of the object. Therefore, in the multi-wavelength GI, in the process using Equation (4), a good result has not been obtained for the reconstructed image G of the sample S.

[0042] In the multi-wavelength GI according to the present embodiment, for the detected optical signal intensity Β αn a detection signal (conversion signal) β αn obtained by performing a normalization process (conversion process) described later is used. Also, for the two-dimensional pattern light Ε αnk a conversion signal (normalization signal) ε αnk obtained by performing a normalization process (conversion process) described later is used, whereby the object image Γ k can be reconstructed from the detection signals of the multi-wavelength GI. Specifically, by using Equation (6), Equation (7), and Equation (8), the object image Γ αn can be reconstructed from the detection signal intensity Β k .

[0043] Equation (6) is for the conversion signal β αn obtained by performing a normalization process (conversion process) on the signal intensity Β αn in each detection round, and takes the difference between the conversion signal β αn obtained by performing a normalization process on the signal intensity Β αn in each detection round and the average value of the conversion signal β αn obtained by performing a normalization process on the signal intensity Β αn in each detection round.

[0044]

Equation

[0045] Equation (7) is for the conversion signal (normalization signal) ε αnk obtained by performing a normalization process (conversion process) on the two-dimensional pattern light Ε αnk corresponding to each detection round, and for the conversion signal ε αnk obtained by performing a normalization process on the two-dimensional pattern light Ε αnk in each detection round and the two-dimensional pattern light Ε αnk The converted signal ε subjected to the normalization process αnk is taking the difference from the average value.

[0046]

Number

[0047] Equation (8) is an equation for obtaining the reconstructed image Γ k of the sample S of multi-wavelength GI. That is, "Γ" k (gamma) represents a function related to the image reconstruction process of multi-wavelength GI.

[0048]

Number

[0049] However, Equation (8) assumes that the reflectance ρ of the sample (object) S does not depend on the wavelength α.

[0050] Subsequently, the normalization process (conversion process) of the detection signal intensity Β αn detected by the detector 16 will be described. In the multi-wavelength GI using the optical measurement device 10 according to the present embodiment, pattern light Ε αnk is projected onto the sample S, and the detection signal intensity Β αn of the transmitted light or reflected light for each wavelength (W1, W2, W3) such as R, G, B from the sample S is detected by, for example, 1 pixel of the detector 16. However, as described above, since the detection signal intensity Β αn has a correlation depending on the wavelength characteristics of each detector 16, the detection signal intensities Β αn for each wavelength are not equivalent (see Fig. 5).

[0051] When solving such problems, generally, as shown in FIG. 6, after measuring the intensity of each wavelength (e.g., R, G, B) from the light source of the illumination unit 12 incident on the detector 16, the intensity of each wavelength from the light source is adjusted. When the intensity ratio of each wavelength emitted from the light source of the illumination unit 12 is detected by a certain detector 16, it is often made constant, for example. However, for such adjustment, as the illumination unit 12, a light source capable of adjusting the intensity for each wavelength is essential. Moreover, since it is necessary to readjust the intensity ratio every time the sample S is changed, the restrictions on the experimental apparatus and the complexity of the setup become problems.

[0052] FIG. 7 shows the sample S, the detection signal, and the conversion signal (normalized signal). The detection signal is the detection signal intensity Β detected by the detector 16 αn , and the detection signal intensity Β αn before normalization processing is performed on the detection signal intensity Β αn shows a histogram. Also, the conversion signal (normalized signal) shows the signal intensity and the histogram regarding the conversion signal β αn after normalization processing is performed on the detection signal intensity Β αn . As shown in FIG. 7, by normalizing the detection signal intensity Β αn , the distributions of each wavelength of the signal β αn can be approximately matched. Such approximate matching of the distributions of each wavelength of the conversion signal β αn means that the conversion signals β αn of each wavelength obtained by normalizing the detection signal intensity Β αn are uncorrelated and equivalent. The key point here is that the conversion signals β αn of each wavelength obtained by normalizing the detection signal intensity Β αn are signals obtained by post-processing of the detection signal intensity Β αn , and it is not necessary to measure and adjust the intensity ratio in advance of the light source of the illumination unit 12.

[0053] Thus, in the processing device 18 of the optical measurement device 10 according to the present embodiment, by performing normalization processing (conversion processing) on the detection signal intensity Β αn , the signals of each wavelength are converted into the conversion signal β αn can be treated as approximately equivalent. In multi-wavelength GI, the conversion signal β αn that can be equivalently treated is used instead of the detection signal intensity Β αn .

[0054] The normalization process of the conversion signal β αn here refers to the conversion process such as the following formula (9) using the ensemble average <Β αn > αn of the detection signal Β n and the standard deviation σ αn of the detection signal intensity Β Β α . Such a conversion process (the first conversion process) is equivalent to performing a conversion process on the intensity value Β αn of the detection signal using independent parameters for each wavelength, and obtaining the first conversion signal β αn corresponding to each of the plurality of wavelengths. αn

[0055]

Equation

[0056] Here, ε αnk obtained by normalizing the pattern light intensity Ε αnk is defined in the same way. By normalizing the pattern light intensity Ε αnk , the distributions of each wavelength of the conversion signal ε αnk are approximately matched. The approximate match of the distributions of each wavelength of such a conversion signal ε αnk means that the conversion signals ε αnk of each wavelength obtained by normalizing the pattern light intensity Ε αnk are uncorrelated and equivalent. The key point here is that the conversion signals ε αnk of each wavelength obtained by normalizing the pattern light intensity Ε αnk are signals obtained by post-processing of the projected pattern light (projected light), and it is not necessary to measure or adjust the intensity ratio in advance of the light source of the illumination unit 12.

[0057] In the processing device 18 of the optical measurement device 10 according to the present embodiment, the pattern light intensity Ε, which is a signal regarding each projection light obtained from the illumination unit 12, αnk is subjected to a normalization process (second conversion process) to convert the signals of each wavelength into conversion signals ε αnk and can be treated approximately equivalently. In multi-wavelength GI, the conversion signal ε αnk that can be treated equivalently is used instead of the pattern light intensity Ε αnk .

[0058] Here, the normalization process of the conversion signal ε αnk refers to a conversion process such as the following formula (10) using the ensemble average <Ε αnk > αnk of the pattern light intensity Ε n and the standard deviation σ αnk of the pattern light intensity Ε Ε αk . Such a conversion process (second conversion process) numerically converts the values (pattern light intensity Ε αnk ) for each wavelength of the pattern light intensity Ε αnk using independent parameters, and this is equivalent to performing this to obtain second conversion signals ε αnk corresponding to each of the plurality of wavelengths.

[0059]

Equation

[0060] As described above, by defining the conversion signal β αn obtained by normalizing the detection signal intensity Β αn and the conversion signal ε αnk obtained by normalizing the pattern light intensity Ε αnk , the function Γ k of the reconstruction process represented by formula (8) can be made proportional to the reflectance distribution ρ k of the sample S.

[0061] As shown in FIG. 8, this means that when reconstructing an object image from the detection signal intensity Β αn , the normalized conversion signals β αn , ε αnk By using this, it is shown that, similar to the equation in which the function G of the reconstruction process is proportional to the reflectance distribution ρ of the sample S as in the conventionally known above-mentioned single-wavelength GI equation (4), it can be treated in the same way.

[0062] Therefore, in the multi-wavelength GI according to the present embodiment, the function Γ of the reconstruction process represented by Equation (8) k is input with the converted signal β obtained by performing a normalization process so that the signals of each wavelength of the detection signal intensity Β αn can be equivalently treated, αn and the converted signal ε obtained by performing a normalization process so that the signals of each wavelength of the pattern light intensity Ε αnk can be equivalently treated. αnk By doing so, the reflectance distribution ρ of the sample S k , that is, an image of the multi-wavelength GI of the sample S can be obtained.

[0063] Therefore, by applying the converted signals β αn , ε αnk to Equation (8), a function Γ k , that is, an image (reconstructed image) proportional to the reflectance ρ of the sample S of the multi-wavelength GI is obtained. At this time, the function Γ k includes performing a process of calculating the average value of the pixel product when the product of the converted signal (first converted signal) β k converted from the intensity value of the detection signal acquired by the detector 16 and the converted signal (second converted signal) ε αn converted from the signals regarding a plurality of projection lights is referred to as the pixel product. αnk

[0064] Note that, compared with the reconstructed image (see FIG. 5) by the conventional method in the multi-wavelength GI using three wavelengths, it is clear that the image (see FIG. 8) reconstructed using the processing device 18 of the optical measurement device 10 according to the present embodiment can reconstruct the state of the sample S (see FIG. 7) better. Therefore, by using the optical measurement device 10 according to the present embodiment, the standardized signals β αn , Ε αn are obtained from the detection signals Β αn , Ε αnk of the multi-wavelength GI, and the standardized signal β αn , ε αnk Based on this, it can be seen that the image Γ of the sample S k has been reconstructed. That is, it can be said that by using the optical measurement device 10 according to this embodiment, high-speed GI due to multi-wavelength can be realized.

[0065] The processing device 18 of the optical measurement device 10 according to this embodiment can operate along the flow shown in FIG. 9.

[0066] As shown in FIG. 9, the processing device 18 projects a plurality of different projection lights, each including a plurality of different wavelengths, toward the sample S (step S1).

[0067] The processing device 18 causes the detector 16 to obtain, as detection signals each having no information regarding the position of a plurality of wavelengths, the detection signal intensities (intensity values) Β of the light of a plurality of wavelengths from the sample S due to each projection of the plurality of projection lights (step S2). Further, the processing device 18 causes a signal regarding the projection light projected onto the sample S at each time from the illumination unit 12 to be obtained. αn The processing device 18 causes the detection signals of each wavelength to be obtained (step S3). At this time, the detection signal intensity Β for each of the measurement times N

[0068] is obtained. Note that the signal regarding the projection light projected onto the sample S at each time from the illumination unit 12 described above may be obtained here. αn The processing device 18 performs a normalization process (first conversion process) on the detection signal intensity Β

[0069] to obtain a conversion signal (first conversion signal) β αn and performs a normalization process (second conversion process) on the pattern light intensity Ε αn to obtain a conversion signal (second conversion signal) ε αnk (step S4). αnk The processing device 18 converts the function Γ of formula (8)

[0070] to the conversion signal (first conversion signal) β k and αn and the conversion signal (second conversion signal) ε αnk are input, and the sample S is reconstructed (step S5). That is, the processing device 18 standardizes the detection signal intensity Β αn by performing a standardization process (first conversion process) to obtain a first conversion signal β αn and the pattern light intensity Ε αnk by performing a standardization process (second conversion process) to obtain a second conversion signal ε αnk and calculates the correlation therebetween, and reconstructs the sample S.

[0071] In this way, the processing device 18 of the optical measurement device 10 according to the present embodiment obtains an image of the sample S based on the function Γ k of Equation (8) (step S6).

[0072] In this manner, the processing device (processing unit) 18 of the optical measurement device 10 according to the present embodiment projects a plurality of different projection lights each including a plurality of different wavelengths onto the sample (object) S. Then, the processing device 18 causes the intensity values of the lights of the plurality of wavelengths from the sample S due to the projection of each of the plurality of projection lights to be respectively obtained as detection signals having no information regarding the position of the plurality of wavelengths at the stage of processing the signals respectively. The processing device 18 performs a numerical conversion process (for example, a standardization process) on the intensity values of the detection signals using parameters independent for each wavelength, and uses this as a first conversion signal (for example, a standardization signal) corresponding to each of the plurality of wavelengths. Further, the processing device 18 performs a conversion process (for example, a standardization process) on the signals regarding the plurality of projection lights projected onto the sample S, and uses this as a second conversion signal (for example, a standardization signal) corresponding to each of the plurality of wavelengths. The processing device 18 obtains an image of the sample S based on the first conversion signal (for example, the first standardization signal) corresponding to the plurality of wavelengths and the second conversion signal (for example, the standardization signal) as the signal regarding the plurality of projection lights.

[0073] The optical measurement method according to this embodiment is performed in accordance with the processing of the above-described processing device 18. The optical measurement method includes projecting a plurality of different projection lights each including a plurality of different wavelengths toward an object, obtaining intensity values of light of a plurality of wavelengths from the object due to each projection of the plurality of projection lights as detection signals each having no information regarding position for the plurality of wavelengths at a stage of processing the signals respectively, performing numerical conversion processing on the intensity values of the detection signals using parameters independent for each wavelength, and using this as a first conversion signal corresponding to the plurality of wavelengths, and obtaining an image of the object based on the first conversion signal corresponding to the plurality of wavelengths and a signal regarding the plurality of projection lights.

[0074] The optical measurement program according to this embodiment is performed in accordance with the processing of the above-described processing device 18. The optical measurement program causes a computer to perform projecting a plurality of different projection lights each including a plurality of different wavelengths toward an object, obtaining intensity values of light of a plurality of wavelengths from the object due to each projection of the plurality of projection lights as detection signals each having no information regarding position for the plurality of wavelengths at a stage of processing the signals respectively, performing numerical conversion processing on the intensity values of the detection signals using parameters independent for each wavelength, and using this as a first conversion signal corresponding to the plurality of wavelengths, and obtaining an image of the object based on the first conversion signal corresponding to the plurality of wavelengths and a signal regarding the plurality of projection lights.

[0075] Therefore, by using the processing device 18 of the optical measurement device 10 according to this embodiment, it is possible to project light of a plurality of wavelengths onto a sample (object) S and obtain an image of the sample S from the detection signals of the respective light intensities. The optical measurement device 10 according to this embodiment can reconstruct an image of a sample (object) S from signals of a plurality of wavelengths acquired by multi-wavelength GI. Therefore, according to this embodiment, it is possible to provide an optical measurement device 10, an optical measurement method, and an optical measurement for projecting light of a plurality of wavelengths onto a sample (object) S and obtaining an image of the sample S from the detection signals of the respective light intensities.

[0076] At this time, since a plurality of signals can be acquired by a single signal detection, the acquisition time when acquiring the same number of signals can be shortened compared to the case where pattern light of a single wavelength without correlation is sequentially projected onto the sample S to acquire an image of the sample S. Therefore, by using the optical measurement apparatus 10 according to the present embodiment, signals of different wavelengths can be effectively utilized, and high-speed multi-wavelength GI can be realized.

[0077] And when using the optical measurement apparatus 10 according to the present embodiment, the conversion signal ε αnk of each wavelength obtained by standardizing the pattern light intensity Ε αnk is a signal obtained by post-processing of the measurement of the pattern light intensity Ε αnk . Therefore, it is not necessary to measure and adjust the intensity ratio in advance of the light source of the illumination unit 12. Therefore, when using the optical measurement apparatus 10 according to the present embodiment, it becomes possible to acquire a reconstructed image by multi-wavelength GI using an arbitrary illumination unit 12.

[0078] Note that the method of conversion processing (standardization) can be changed according to the type of the illumination unit 12 and the sample S, and Equation (9) is merely an example. Equation (9) can be set as in Equation (11) using, for example, the median m αn > n instead of the ensemble average <Β αn of the detection signals Β Β α in all measurements.

[0079]

Equation

[0080] Also, Equation (9) can be set as in Equation (12) using, for example, the ensemble average <Β αn > n or the mode M αn of the detection signals Β Β α in all measurements.

[0081]

Equation

[0082] Alternatively, Equation (9) can be set as in Equation (13) using the variance V of the detection signal intensity Β instead of the standard deviation σ. Β α rather than the detection signal intensity Β αn of the variance V Β α can also be used.

[0083]

Number

[0084] Therefore, the processing device 18 can handle the conversion signals β of each wavelength as uncorrelated and equivalent by performing conversion processing on the intensity value Β of the detection signal using independent parameters for each wavelength. Then, as such conversion processing, the processing device 18 can handle the conversion signals β of each wavelength as uncorrelated and equivalent by performing processing to convert the intensity value Β of the detection signal using statistical information. The statistical information of the intensity value Β of the detection signal includes at least one of information related to the average value (ensemble average) <Β> of the intensity value Β of the detection signal, the median m, the mode M, the variance value V, and the standard deviation σ. αn for each wavelength of the intensity value Β using independent parameters for each wavelength αn of the intensity value Β and converting the numerical value, and when this is set as the conversion signal β corresponding to at least two different wavelengths αn of each wavelength αn can be handled as uncorrelated and equivalent. And the processing device 18 can handle the conversion signals β of each wavelength as uncorrelated and equivalent by performing processing to convert the intensity value Β of the detection signal using statistical information. And the statistical information of the intensity value Β of the detection signal αn is the average value (ensemble average) <Β> of the intensity value Β of the detection signal αn for each wavelength αn and the statistical information of the intensity value Β of the detection signal αn is the average value (ensemble average) <Β> αn > n the median m Β α the mode M Β α the variance value V Β α the standard deviation σ Β α includes at least one of the information related thereto.

[0085] This is not only for the intensity value Β of the detection signal αn but also for the two-dimensional pattern light (illuminance) Ε αnk It can also be applied to. That is, as a conversion process, the processing device 18 performs a process of converting the two-dimensional pattern light (illuminance) Ε αnk using statistical information, so that the conversion signals ε of each wavelength αnk can be treated as uncorrelated and equivalent.

[0086] Furthermore, as the illumination unit 12, when using a light source in which the pixel value of the input data (projected light) and the pattern light intensity (illuminance of the output light) Ε αnk are in a linear relationship, by setting an appropriate pattern as the input data (projected light), the input data of the illuminance Ε αnk can be treated as a signal ε αnk after normalization processing. That is, when using such a light source as the illumination unit 12, it is necessary that the pattern light is uncorrelated, but each wavelength can be processed equivalently. Therefore, when obtaining a reconstructed image of multi-wavelength GI, the normalization processing (conversion processing) of the input signal Ε αnk of the projected pattern light may not be necessary. As an example of the light source of the illumination unit 12, by using a projector, the conversion process may not be necessary for the pattern light intensity (illuminance of the output light) Ε αnk

[0087] Therefore, the processing device (processing unit) 18 of the optical measurement device 10 according to the present embodiment projects a plurality of different projected lights each including a plurality of different wavelengths toward the sample (object) S. Then, the processing device 18 causes the intensity values of the lights of a plurality of wavelengths from the sample S due to the projection of each of the plurality of projected lights to be respectively obtained as detection signals having no information regarding the position of the plurality of wavelengths at the stage of processing the signals respectively. The processing device 18 performs numerical conversion processing (for example, normalization processing) on the intensity values of the detection signals using independent parameters for each wavelength, and sets this as a first conversion signal (for example, a normalization signal) corresponding to each of the plurality of wavelengths. The processing device 18 obtains an image of the sample S based on the first conversion signals (for example, the first normalization signals) corresponding to the plurality of wavelengths and the signals regarding the plurality of projected lights.

[0088] ​According to the processing device 18, the optical measurement device 10, the optical measurement method, and the optical measurement program of at least one of the above-described embodiments, light of a plurality of wavelengths can be projected onto an object (sample) S, and an image of the object can be acquired from detection signals (light intensity values) of the respective light intensities.

[0089] As described above, the embodiments of the present invention have been described. However, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.

Explanation of Reference Numerals

[0090] 10... optical measurement device, 12... illumination unit, 14... optical element, 16... single pixel detector, 18... processing device, PR1,..., PRn... pattern light, W1... first wavelength, W2... second wavelength, W3... third wavelength.< / ax>

Claims

1. Projecting a plurality of different projection lights, each including a plurality of different wavelengths, toward an object, obtaining, for each projection of the plurality of projection lights, intensity values of light of the plurality of wavelengths from the object as detection signals that do not carry information regarding position for the plurality of wavelengths, respectively, in a stage of processing signals, performing numerical conversion processing on the intensity values of the detection signals using parameters independent for each wavelength, and using this as first conversion signals corresponding to the plurality of wavelengths respectively, obtaining an image of the object based on the first conversion signals corresponding to the plurality of wavelengths and a signal regarding the plurality of projection lights, A processing device having a processing unit.

2. When converting the intensity values of the detection signals into the first conversion signals, the processing unit performs processing of converting using statistical information of the intensity values of the detection signals. The processing device according to Claim 1.

3. The statistical information of the intensity values of the detection signals includes at least one of information regarding the average value, median value, mode value, variance value, and standard deviation of the intensity values of the detection signals. The processing device according to Claim 2.

4. The processing unit performs numerical conversion processing on the intensity value for each wavelength of the projection light projected toward the object using a parameter independent for each wavelength, and uses this as a second conversion signal corresponding to the plurality of wavelengths, When obtaining an image of the object, the processing unit obtains the image of the object based on the first conversion signal and the second conversion signal. The processing device according to any one of Claims 1 to 3.

5. When obtaining the image of the object based on the first conversion signal and the second conversion signal, the processing unit includes at least processing of calculating an average value of pixel products, where the pixel product is at least the product of the first conversion signal and the second conversion signal. The processing device according to Claim 4.

6. The processing device according to any one of Claims 1 to 3, an illumination unit that projects the projection light toward the object, a detector that obtains the detection signal, An optical measurement device having the above.

7. The illumination unit is controlled by the processing device, The projection light projected toward the object has a spatial intensity distribution. The optical measurement device according to Claim 6.

8. Projecting a plurality of different projection lights, each including a plurality of different wavelengths, toward an object Causing intensity values of light of a plurality of wavelengths from the object due to projection of each of the plurality of projection lights to be respectively obtained as detection signals having no information regarding position for the plurality of wavelengths, at a stage of processing signals respectively; Performing numerical conversion processing on the intensity values of the detection signals using parameters independent for each wavelength, and using this as a first conversion signal corresponding to the plurality of wavelengths; Obtaining an image of the object based on the first conversion signal corresponding to the plurality of wavelengths and a signal regarding the plurality of projection lights; An optical measurement method comprising the above.

9. Projecting a plurality of different projection lights each including a plurality of different wavelengths towards an object; Causing intensity values of light of a plurality of wavelengths from the object due to projection of each of the plurality of projection lights to be respectively obtained as detection signals having no information regarding position for the plurality of wavelengths, at a stage of processing signals respectively; Performing numerical conversion processing on the intensity values of the detection signals using parameters independent for each wavelength, and using this as a first conversion signal corresponding to the plurality of wavelengths; Obtaining an image of the object based on the first conversion signal corresponding to the plurality of wavelengths and a signal regarding the plurality of projection lights; An optical measurement program causing a computer to execute the above.

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