Image acquisition device and image acquisition method

Abstract

The image acquisition device (100) includes an illumination system unit (110) that irradiates a measurement target with an illumination pattern provided with a two-dimensional pattern formed using a plurality of sections and a shifted illumination pattern obtained by shifting the illumination pattern along an irradiation surface, a reception unit (130) that receives light from the measurement target when the measurement target is irradiated with the illumination pattern and the shifted illumination pattern by the illumination system unit via a single-pixel photodetector, and a signal processing unit (150) that acquires a reception signal based on the light received by the reception unit and generates a two-dimensional image of the measurement target based on changes in the reception signal when the measurement target passes over the illumination pattern and changes in the reception signal when the measurement target passes over the shifted illumination pattern.

Description

Technical Field

[0001] The disclosed technology relates to an image acquisition technology for acquiring an image of a measurement object by irradiating an illumination pattern formed using a two-dimensional pattern.

Background Art

[0002] Among image acquisition technologies, there is a technology called single pixel imaging (SPI). In SPI, a large number of two-dimensional illumination patterns are irradiated onto a measurement object, and the reflected light and scattered light from the measurement object are recorded by a single-pixel detector. By associating the illuminated two-dimensional pattern with the received signal intensity and applying signal processing to that information, it is possible to acquire a two-dimensional image of the measurement object even though only a single-pixel detector is used. SPI is a particularly useful technology in wavelength bands where two-dimensional array detectors are expensive or difficult to implement. On the other hand, in order to generate a large number of two-dimensional patterns, it requires a spatial light modulator such as a digital micromirror device (DMD) that can dynamically control the display pattern.

[0003] In contrast, Non-Patent Document 1 describes a technology for acquiring a two-dimensional image of a measurement object by simply irradiating a single illumination pattern onto a measurement object moving at a constant speed. As the measurement object moves at a constant speed, the positional relationship between the measurement object and the illumination pattern changes. As a result, the apparent illumination pattern (hereinafter also referred to as the illumination frame) irradiated onto the measurement object changes, so a two-dimensional image can be acquired based on the same principle as general SPI. In this configuration, since a single illumination pattern is sufficient, there is no need to dynamically change the illumination pattern, and a spatial light modulator such as a DMD becomes unnecessary.

Prior Art Documents

Non-Patent Documents

[0004]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when performing SPI with a configuration as shown in Non-Patent Document 1, the number of apparent illumination patterns (illumination frames) is proportional to the length of the measurement target moving direction of the illumination pattern. Therefore, there is a problem that the size of the illumination pattern increases as the number of illumination frames increases in order to ensure image acquisition accuracy.

[0006] This disclosure solves the above problems, and when acquiring a two-dimensional image of a measurement target using a single illumination pattern, it suppresses an increase in the size of the illumination pattern while increasing the number of apparent illumination patterns (illumination frames). The purpose is to provide a technology.

Means for Solving the Problems

[0007] The image acquisition device of this disclosure is An illumination system unit that irradiates a measurement target with an illumination pattern provided with a two-dimensional pattern formed using a plurality of sections and a shifted illumination pattern obtained by shifting the illumination pattern along an irradiation surface, A receiving unit that receives light from the measurement target when the illumination pattern and the shifted illumination pattern are irradiated on the measurement target by the illumination system unit through a single-pixel photodetector, A signal processing unit that acquires a reception signal based on the light received by the receiving unit, and generates a two-dimensional image of the measurement target based on the change in the reception signal when the measurement target passes over the illumination pattern and the change in the reception signal when the measurement target passes over the shifted illumination pattern, is provided.

Effects of the Invention

[0008] According to the present disclosure, when acquiring a two-dimensional image of a measurement object using a single illumination pattern, it is possible to increase the number of apparent illumination patterns (illumination frames) while suppressing an increase in the size of the illumination pattern, and this has the effect of making it possible.

Brief Description of the Drawings

[0009]

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Embodiments for Carrying Out the Invention

[0010] The image acquisition device of the present disclosure utilizes the SPI technology to illuminate a measurement object with a two-dimensional pattern and capture the reflection and scattering of the illumination light from the measurement object with a single-pixel detector to obtain a two-dimensional image of the measurement object. In general SPI, a large number of illumination patterns are irradiated onto the measurement object, and the corresponding received signal intensities are recorded. Classically, in order to completely acquire the image of the measurement object, the number of illumination patterns needs to be larger than the total number of pixels of the image to be acquired (if the resolution is 640x480, the total number of pixels is 640x480). Although it is possible to reduce the number of necessary illumination patterns by applying a signal processing method using the principle of compressive sensing, in order to improve the image acquisition accuracy, still a certain number or more of illumination patterns are required. Also, as already described, when performing SPI with the configuration as shown in Non-Patent Document 1, since the number of apparent illumination patterns (illumination frames) is proportional to the length of the measurement object in the moving direction of the illumination pattern, the larger the number of illumination frames is increased to ensure the image acquisition accuracy, the larger the size of the illumination pattern becomes. The image acquisition device of the present disclosure enables an increase in the number of apparent illumination patterns (illumination frames) while suppressing an increase in the size of the illumination pattern when acquiring a two-dimensional image of a measurement object using a single illumination pattern. Hereinafter, in order to explain the present disclosure in more detail, embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0011] Embodiment 1. In Embodiment 1, the basic form of the present disclosure will be described.

[0012] [Configuration] A configuration example of the image acquisition device according to Embodiment 1 of the present disclosure will be described. FIG. 1 is a diagram showing a basic configuration example of the image acquisition device according to Embodiment 1 of the present disclosure.

[0013] The image acquisition device 100 irradiates a measurement object with an illumination pattern provided with a two-dimensional pattern formed using a plurality of sections, and a shifted illumination pattern obtained by shifting the illumination pattern along the irradiation surface, and receives light from the measurement object when the illumination pattern and the shifted illumination pattern are irradiated on the measurement object via a single-pixel photodetector, obtains a reception signal based on the received light, and generates a two-dimensional image of the measurement object based on a change in the reception signal when the measurement object passes over the illumination pattern and a change in the reception signal when the measurement object passes over the shifted illumination pattern. The image acquisition device 100 shown in FIG. 1 includes an illumination system unit 110, a reception unit 130, and a signal processing unit 150.

[0014] The illumination system unit 110 irradiates a measurement object with an illumination pattern provided with a two-dimensional pattern formed using a plurality of sections, and a shifted illumination pattern obtained by shifting the illumination pattern along the irradiation surface. The irradiation surface is, for example, the same or substantially the same surface as the surface where the measurement object, which is the object for which an image is to be acquired by the image acquisition device 100, exists or passes through. Also, for example, it is the same or substantially the same surface as the moving surface for moving the measurement object. The irradiation surface may be set so that the illumination pattern and the shifted illumination pattern can be irradiated onto an area where an image of the measurement object for which an image is to be acquired by the image acquisition device 100 can be acquired.

[0015] The illumination pattern has, for example, a two-dimensional pattern structure given using a plurality of sections into which the rectangular irradiation region is periodically divided in a rectangular irradiation region. The illumination pattern is formed in such a form that light is passed or not passed for each of the plurality of sections. The shift illumination pattern is one that is irradiated with the illumination pattern shifted along the irradiation surface. The shift illumination pattern is, for example, when the measurement object, which is the object for which an image is to be acquired by the image acquisition device 100, is moving, shifted in a direction perpendicular to the moving direction of the moving surface of the measurement object (the moving direction 250 shown in FIG. 3 and the like described later) (the direction α shown in FIG. 3 and the like described later) and irradiated. That is, the horizontal relative position between the measurement object and the illumination pattern and the horizontal relative position between the measurement object and the shift illumination pattern do not change. The illumination pattern and the shift illumination pattern are formed by imparting a single two-dimensional pattern to light.

[0016] The illumination system unit 110 includes, for example, a light source, a configuration for imparting a pattern to light, and an illumination optical system.

[0017] When the illumination pattern and the shift illumination pattern are irradiated onto the measurement object by the illumination system unit, the receiving unit 130 receives light from the measurement object via a single-pixel photodetector. The receiving unit 130 includes, for example, a single-pixel photodetector.

[0018] The signal processing unit 150 acquires a reception signal based on the light received by the receiving unit, and generates a two-dimensional image of the measurement object based on the change in the reception signal when the measurement object passes over the illumination pattern and the change in the reception signal when the measurement object passes over the shift illumination pattern.

[0019] In addition to the above configuration, the image acquisition device 100 includes a control unit (not shown), a storage unit (not shown), and a communication unit (not shown). A control unit (not shown) controls the entire image acquisition device 100 and each component. For example, the control unit (not shown) activates the image acquisition device 100 according to an external command. Further, the control unit (not shown) controls the state of the image acquisition device 100 (operation states such as activation, shutdown, sleep). A storage unit (not shown) stores each data used in the image acquisition device 100. For example, the storage unit (not shown) stores the output (output data) by each component in the image acquisition device 100, and outputs the data requested for each component to the component that is the request source. A communication unit (not shown) communicates with an external device. For example, communication is performed between the image acquisition device 100 (100A) and a peripheral device (for example, a display device). For example, when the image acquisition device 100 and the display device are not wired-connected, the communication unit (not shown) has a function of performing communication between the image acquisition device 100 and the display device. Further, the communication unit (not shown) has a function of performing communication with a server device which is an external device. The control unit (not shown), the storage unit (not shown), and the communication unit (not shown) are the same also in the embodiments described later.

[0020] [Operation] A processing example of the image acquisition device will be described.

[0021] FIG. 2 is a diagram showing an example of the basic operation of the image acquisition device 100 according to Embodiment 1 of the present disclosure. The process shown in FIG. 2 is an image acquisition method by the image acquisition device 100. For example, the image acquisition device shown in FIG. 1 starts the process shown in FIG. 2 when instructed to start operating from outside the device. Or, when it is detected that a measurement target exists, the process shown in FIG. 2 is started.

[0022] The image acquisition device 100 first irradiates light with a 2D pattern. In the irradiation process, the illumination system unit 110 of the image acquisition device 100 irradiates an illumination pattern and a shift illumination pattern (step ST1100). Specifically, the illumination system unit 110 irradiates a measurement target with an illumination pattern provided with a two-dimensional pattern formed using a plurality of sections, and a shifted illumination pattern obtained by shifting the illumination pattern along the irradiation surface.

[0023] The image acquisition device 100 then receives light (step ST1200). In step ST1200, the light receiving unit 130 of the image acquisition device 100 receives light from the measurement target when the illumination pattern and the shifted illumination pattern are irradiated onto the measurement target by the illumination system unit 110, via a single-pixel photodetector. The light receiving unit 130 outputs the received light to the signal processing unit 150 as a received signal.

[0024] The image acquisition device 100 then performs received signal processing (step ST1300). In the received signal processing, the signal processing unit 150 of the image acquisition device 100 acquires a received signal based on the light received by the light receiving unit 130, performs signal processing on the received signal related to the illumination pattern, and performs signal processing on the received signal related to the shifted illumination pattern. The signal processing unit 150 associates a virtual illumination pattern (illumination frame) in which an imaging target is likely to exist in the entire illumination pattern with the pixels indicated in the illumination pattern received signal. In addition, the signal processing unit 150 associates a virtual illumination pattern (illumination frame) in which an imaging target is likely to exist in the entire shifted illumination pattern with the pixels indicated in the received signal related to the shifted illumination pattern.

[0025] The image acquisition device 100 then performs signal integration processing (step ST1400). In signal integration processing, the signal processing unit 150 of the image acquisition device 100 integrates the received signal related to the illumination pattern after reception signal processing and the received signal related to the shifted illumination pattern after reception signal processing. For example, the signal processing unit 150 integrates the received signal related to the illumination pattern after reception signal processing and the received signal related to the shifted illumination pattern after reception signal processing by simply concatenating them before and after.

[0026] The image acquisition device 100 then executes image generation processing (step ST1500). In the image generation processing, the signal processing unit 150 of the image acquisition device 100 generates an image using the received signal after signal integration processing.

[0027] The image acquisition device 100 then executes image output processing (step ST1600). In the image output processing, the signal processing unit 150 of the image acquisition device 100 outputs the generated image. The image acquisition device 100 outputs it to the outside of the device, for example. Or it outputs it to a display device (not shown).

[0028] The image acquisition device then proceeds to end determination processing (step ST1700). In the end determination processing, a control unit (not shown) of the image acquisition device determines whether to end the processing of the image acquisition device. For example, the control unit (not shown) determines whether to end the processing of the image acquisition device according to an end command from the outside or an execution program. If the control unit (not shown) determines not to end the processing of the image acquisition device (step ST1700 “NO”), the process proceeds to the processing of step ST1200, and repetitive processing is performed from the processing of step ST1200. If the control unit (not shown) determines to end the processing of the image acquisition device (step ST1700 “YES”), the image acquisition device ends the processing.

[0029] The image acquisition device according to the present disclosure of the present embodiment is configured as follows, for example. An illumination system unit that irradiates a measurement target with an illumination pattern provided with a two-dimensional pattern formed using a plurality of sections, and a shifted illumination pattern obtained by shifting the illumination pattern along an irradiation surface. A receiving unit that receives light from the measurement target when the illumination pattern and the shifted illumination pattern are irradiated on the measurement target by the illumination system unit through a single-pixel photodetector. A signal processing unit that acquires a reception signal based on the light received by the receiving unit, and generates a two-dimensional image of the measurement target based on a change in the reception signal when the measurement target passes over the illumination pattern and a change in the reception signal when the measurement target passes over the shifted illumination pattern. An image acquisition device comprising the above. Accordingly, the present disclosure can provide an image acquisition device that has an effect of being able to increase the number of apparent illumination patterns (illumination frames) while suppressing an increase in the size of the illumination pattern when acquiring a two-dimensional image of a measurement target using a single illumination pattern.

[0030] The image acquisition method of the present disclosure according to the present embodiment is configured as follows, for example. An image acquisition method by an image acquisition device, wherein the image acquisition device irradiates a measurement target with an illumination pattern provided with a two-dimensional pattern formed using a plurality of sections, and a shifted illumination pattern obtained by shifting the illumination pattern along a pattern surface, the image acquisition device receives light from the measurement target irradiated with the illumination pattern and the shifted illumination pattern through a single-pixel photodetector, the image acquisition device acquires a reception signal based on the light received through the single-pixel photodetector, and generates a two-dimensional image of the measurement target based on a change in the reception signal when the measurement target passes over the illumination pattern and a change in the reception signal when the measurement target passes over the shifted illumination pattern. Image acquisition method. Accordingly, the present disclosure has the effect of being able to provide an image acquisition method that enables increasing the number of apparent illumination patterns (illumination frames) while suppressing an increase in the size of the illumination pattern when acquiring a two-dimensional image of a measurement object using a single illumination pattern.

[0031] Embodiment 2. Embodiment 2 describes a more detailed example of Embodiment 1. In Embodiment 2, among the components according to Embodiment 2, for components that are the same as or similar to the components according to Embodiment 1 that have already been described, the same names and the same or similar reference numerals are given, and duplicate descriptions are omitted as appropriate.

[0032] [Configuration] FIG. 3 is a diagram showing a configuration example of an image acquisition device 100A according to Embodiment 2 of the present disclosure, and a configuration example when the image acquisition device 100A is applied to a measurement system. The measurement system has a configuration for moving a measurement object, acquires an image of the measurement object using an image acquisition device, performs measurement and inspection of the measurement object using the acquired image, and outputs an inspection result. The image acquisition device 100A shown in FIG. 3 includes an illumination system unit 110A, a reception unit 130A, and a signal processing unit 150A.

[0033] The illumination system unit 110A irradiates while switching between the illumination pattern and one or more shifted illumination patterns obtained by shifting the illumination pattern by the illumination pattern shift unit over time. The relative position in the horizontal direction between the measurement object and the illumination pattern, and the relative position in the horizontal direction between the measurement object and the shifted illumination pattern do not change with the switching between the illumination pattern and the shifted illumination pattern. The horizontal direction is the same as the moving direction 250 of the moving surface that moves the measurement target in a state where the image acquisition device 100A is installed to acquire an image of the measurement target that moves. The illumination system unit 110A shown in FIG. 3 includes an illumination control unit 111A, a time-division multiplexed light source unit 112A, a fixed pattern generation unit 113, a pattern multiplexing unit 114, and an illumination optical system 115.

[0034] The illumination control unit 111A has a function of controlling the switching of the wavelength of the output light from the time-division multiplexed light source unit 112 and a function of transmitting the timing of the wavelength switching to the signal processing unit 150A.

[0035] The time-division multiplexed light source unit 112A has a function of irradiating the fixed pattern generation unit 113 while switching two lights having different wavelengths based on the control from the illumination control unit 111A. The time-division multiplexed light source unit 112A constitutes the light source unit in the present disclosure.

[0036] The fixed pattern generation unit 113 has a function of imparting a spatial modulation pattern to the light irradiated from the time-division multiplexed light source unit 112. The spatial pattern generated by the fixed pattern generation unit 113 is always the same and does not have a function of dynamically changing the pattern like a spatial light modulator typified by a DMD. That is, the fixed pattern generation unit 113 is configured by a static structure. Thereby, the fixed pattern generation unit 113 and the surrounding optical system and control system are miniaturized, cost-reduced, and highly reliable. The fixed pattern generation unit 113 constitutes the pattern generation unit of the present disclosure. The pattern generation unit (fixed pattern generation unit 113) imparts a two-dimensional pattern to the light emitted from the light source unit (time-division multiplexed light source unit 112A). The pattern generation unit (fixed pattern generation unit 113) is configured by a static structure that imparts a single two-dimensional pattern to the light emitted from the light source unit (time-division multiplexed light source unit 112A).

[0037] The illumination optical system 115 has a function of transferring the spatial modulation pattern imparted to the light that has passed through the fixed pattern generation unit 113 onto the measurement target 200. The modulation pattern to be transferred is the illumination pattern 410 or the shifted illumination pattern 420. The illumination optical system 115 is an imaging optical system composed of lenses and mirrors, and the shape and number of lenses and mirrors are not limited. The illumination optical system 115 of the present disclosure projects the light to which a two-dimensional pattern has been imparted by the pattern generation unit (fixed pattern generation unit 113) onto the measurement target.

[0038] The pattern multiplexing unit 114 has a function of switching the modulation pattern transferred to the measurement target 200 to either the illumination pattern 410 or the shifted illumination pattern 420 according to the wavelength of the light by imparting wavelength-dependent refraction to the light that has passed through the fixed pattern generation unit 113. The pattern multiplexing unit 114 is a wavelength dispersion element such as a prism or a diffraction grating. The pattern multiplexing unit 114 constitutes the illumination pattern shift unit of the present disclosure. The illumination pattern shift unit (pattern multiplexing unit 114) shifts the illumination pattern generated by the illumination optical system 115.

[0039] The illumination pattern 410 shown in FIG. 3 is a two-dimensional spatial modulation pattern transferred onto the measurement target 200 by the illumination optical system 115. The illumination pattern 410 has a structure that is two-dimensionally and periodically divided by a large number of sections. The luminance of each section may have a physical meaning such as a wavelet or Fourier, or may be random. Also, there may be a luminance distribution within the section.

[0040] The shift illumination pattern 420 is the one obtained by shifting the illumination pattern 410 by the pattern multiplexing unit 114. The shift amount is one section of the illumination pattern 410 in the direction α perpendicular to the movement of the measurement target 200 (hereinafter simply referred to as the perpendicular direction α). By setting the shift amount in this way, each section of the shift illumination pattern 420 in the perpendicular direction α coincides with each section of the illumination pattern 410 in the perpendicular direction α. Note that since it is a condition that the sections of the illumination pattern 410 of the shift illumination pattern 420 coincide, the shift amount is not limited to one section and may be an integer multiple thereof. Also, in order to compensate for the shift in the direction horizontal to the movement of the measurement target 200 (hereinafter simply referred to as the horizontal direction) due to the movement of the measurement target 200 during switching, the shift illumination pattern 420 may have a horizontal shift amount that coincides with the movement distance of the measurement target 200.

[0041] The number of sections of the illumination pattern 410 in the perpendicular direction α is the vertical resolution of the output image from this device plus the shift amount (one section in this embodiment) or more. Thereby, it is guaranteed that the measurement target 200 also fits within the illumination pattern in the shift illumination pattern 420. Also, the number of sections of the illumination pattern 410 in the horizontal direction is sufficiently larger than the horizontal resolution of the finally output image. This is because the number of sections of the illumination pattern 410 in the horizontal direction corresponds to the number of illumination frames. When this device outputs an image with a resolution of 32x32, the resolution of the illumination pattern 410 is, for example, 33x231. In this case, the number of illumination frames is 200.

[0042] The measurement target 200 is the target for which an image is acquired by the image acquisition device according to the present disclosure. The size of the measurement target 200 is smaller than the area of the illumination pattern corresponding to the output image from the device. For example, when outputting an image with a resolution of 32x32, it is smaller than the range of 32x32 sections on the illumination pattern.

[0043] The object driving unit 300 has a function of moving the measurement target 200 at a constant speed. The moving direction 250 is perpendicular to the paper surface in FIG. 3. The object driving unit 300 is, for example, a belt conveyor used on a factory line.

[0044] The light receiving unit 130A receives the light from the measurement target when the illumination pattern and the shift illumination pattern are irradiated onto the measurement target by the illumination system unit via a single-pixel photodetector. The light receiving unit 130A includes a light receiving optical system 131 and a single-pixel light detection unit 132.

[0045] The light receiving optical system 131 has a function of condensing the illumination pattern 410 or the shift illumination pattern 420 reflected and scattered by the measurement target 200 onto the single-pixel light detection unit 132. "Reflection and scattering" represents reflection, scattering, or both reflection and scattering. The light receiving optical system 131 is an imaging optical system composed of lenses and mirrors, and the shape and number of lenses and mirrors are not limited.

[0046] The single-pixel light detection unit 132 has a function of converting the light condensed by the light receiving optical system 131 into an electrical signal. The signal is acquired at a period that is half or less of the time it takes for the measurement target 200 to pass through one section of the illumination pattern 410. The single-pixel light detection unit 132 is a so-called photodetector. For example, in the visible wavelength band, those made of Si, and in the short infrared wavelength band, those made of InGaAs or Ge are generally used.

[0047] The signal processing unit 150A acquires a reception signal based on the light received by the light receiving unit 130A, and generates a two-dimensional image of the measurement target based on the change in the reception signal when the measurement target passes over the illumination pattern and the change in the reception signal when the measurement target passes over the shift illumination pattern. The signal processing unit 150A receives the electrical signal from the single-pixel light detection unit 132 and the timing signal from the illumination control unit 111A, and has a function of reconstructing an image of the measurement target 200.

[0048] FIG. 4 is a diagram showing a configuration example of the illumination system unit 110A in the image acquisition device 100A according to Embodiment 2 of the present disclosure. FIG. 4 is a diagram showing a specific configuration of the illumination system unit 110A. The illumination system unit 110A includes an illumination control unit 111A, a single-color laser 112A-1, a single-color laser 112A-2, a beam combiner 112A-3, an illumination pattern mask 113-1, a prism 114-1, and an illumination lens 115-1.

[0049] The single-color laser 112A-1 and the single-color laser 112A-2 are laser light sources having different output wavelengths and have a function of emitting light at a timing specified by the illumination control unit 111A. The wavelengths of the single-color laser 112A-1 and the single-color laser 112A-2 are set so that the illumination patterns generated by both lasers obtain a desired shift amount in consideration of the wavelength dispersion characteristics and the installation angle of the prism 114-1.

[0050] The beam combiner 112A-3 has a function of combining the light output from the single-color laser 112A-1 and the single-color laser 112A-2.

[0051] The illumination pattern mask 113-1 has a function of imparting a spatial modulation pattern to the light from the beam combiner 112A-3. The illumination pattern mask 113-1 is composed of a large number of sections arranged periodically in two dimensions. For example, in some sections, small holes are opened in the center. Thereby, a binary pattern such as 1 in the section with a small hole and 0 in the section without a small hole is imparted. Since such an illumination pattern mask 113-1 can be mass-produced by laser processing, it is excellent in manufacturing cost.

[0052] The prism 114-1 has a function of separating the propagation directions of the light of the single-color laser 112A-1 and the single-color laser 112A-2. By configuring in this way, the illumination pattern 410 and the shifted illumination pattern 420 can be switched in a configuration that does not include a mechanical drive unit.

[0053] The illumination lens 115-1 has a function of transferring the illumination pattern mask 113-1 onto the measurement object 200.

[0054] FIG. 5 is a diagram showing a configuration example of a signal processing unit 150A in the image acquisition device 100A according to Embodiment 2 of the present disclosure. FIG. 5 is a configuration diagram of the signal processing unit 150A, and includes an AD conversion unit 151, a time synchronization unit 152, a signal separation unit 153, an illumination frame group holding unit 154, an illumination frame group synchronization unit 155, a shifted illumination frame group synchronization unit 156, a calibration processing unit 157, a signal integration unit 158, an image reconstruction unit 159, and an image output unit 160.

[0055] The AD conversion unit 151 has a function of converting an electrical signal from the single-pixel light detection unit 132 into a digital signal.

[0056] The time synchronization unit 152 has a function of associating the received signal from the AD conversion unit 151 with the position of the measurement target 200 (the illumination pixel number on the illumination pattern). For example, characteristic patterns are provided at the left and right ends in the horizontal direction of the illumination pattern 410, and by identifying the timing when the characteristic pattern passes in the received signal, the time axis of the received signal can be associated with the position of the measurement target 200.

[0057] The signal separation unit 153 has a function of determining and separating signals corresponding to the illumination pattern 410 and the shifted illumination pattern 420 from the received signal from the time synchronization unit 152 using the timing information from the illumination control unit 111. Further, it also has a function of transmitting the part corresponding to the illumination pattern 410 to the illumination frame group synchronization unit 155 and the part corresponding to the shifted illumination pattern 420 to the shifted illumination frame group synchronization unit 156, respectively.

[0058] The illumination frame group holding unit 154 has a function of holding an illumination frame group corresponding to the illumination pattern 410 and the shift illumination pattern 420. The illumination frame is an apparent illumination pattern irradiated on the measurement object 200, and corresponds to a portion cut out from the illumination pattern in the range corresponding to the measurement object 200. The illumination frame group is obtained by virtually moving the measurement object 200 one section at a time, extracting the illumination frames at each position of the measurement object 200, and collecting them. For example, when the number of sections of the illumination pattern 410 is 33x301 and the size of the measurement object 200 corresponds to 32x32 sections, the illumination frame group has 270 illumination frames with a resolution of 32x32. Therefore, the illumination frame group has an arrangement of 32x32x270.

[0059] The illumination frame group synchronization unit 155 has a function of associating each point of the received signal corresponding to the illumination pattern 410 with each illumination frame of the illumination frame group output from the illumination frame group holding unit 154.

[0060] The shift illumination frame group synchronization unit 156 has a function of associating each point of the received signal corresponding to the shift illumination pattern 420 with each illumination frame of the illumination frame group output from the illumination frame group holding unit 154.

[0061] The calibration processing unit 157 has a function of calibrating the received signals output from the illumination frame group synchronization unit 155 and the shift illumination frame group synchronization unit 156. Specifically, it includes removing offsets, correcting if the illumination power is different between the illumination pattern 410 and the shift illumination pattern 420, and so on.

[0062] The signal integration unit 158 has a function of concatenating the illumination frame groups and the received signals output from both the illumination frame group synchronization unit 155 and the shift illumination frame group synchronization unit 156 to create an integrated received signal and an integrated illumination frame group.

[0063] The image reconstruction unit 159 has a function of performing image reconstruction processing on the integrated reception signal and the integrated illumination frame group output from the signal integration unit 158, and generating a two-dimensional image of the measurement target 200.

[0064] The image output unit 160 has a function of outputting the image generated by the image reconstruction unit 159. The output destination is a display, an image inspection device, or the like.

[0065] [Operation] A processing example of the signal processing unit in the image processing apparatus according to Embodiment 2 of the present disclosure will be described. FIG. 6 is a flowchart showing a processing example of the signal processing unit 150A in the image acquisition apparatus 100A according to Embodiment 2 of the present disclosure. The signal processing unit 150A starts processing when receiving a signal from the receiving unit 130A, for example.

[0066] The signal processing unit 150A executes an AD conversion process (step ST2110). In the AD conversion process, the AD conversion unit 151 of the signal processing unit 150A converts the electrical signal from the single-pixel light detection unit 132 into a digital signal. The AD conversion unit 151 outputs the digitized reception signal to the time synchronization unit 152.

[0067] The signal processing unit 150A then executes a time synchronization process (step ST2120). In the time synchronization process, the time synchronization unit 152 of the signal processing unit 150A associates the reception signal from the AD conversion unit 151 with the position of the measurement target 200 (the illumination pixel number on the illumination pattern).

[0068] The signal processing unit 150A then executes a signal separation process (step ST2130). In the signal separation process, the signal separation unit 153 of the signal processing unit 150A determines and separates the signals corresponding to the illumination pattern 410 and the shift illumination pattern 420 from the reception signal from the time synchronization unit 152 using the timing information from the illumination control unit 111.

[0069] The signal processing unit 150A then executes illumination frame group synchronization processing (step ST2140). In the illumination frame group synchronization processing, the illumination frame group synchronization unit 155 of the signal processing unit 150A associates each point of the received signal corresponding to the illumination pattern 410 with each illumination frame of the illumination frame group output from the illumination frame group holding unit 154.

[0070] The signal processing unit 150A then executes calibration processing (step ST2150). In the calibration processing, the calibration processing unit 157a of the signal processing unit 150A calibrates the received signal output from the illumination frame group synchronization unit 155. Specifically, the calibration processing unit 157a performs offset removal, correction if the illumination power is different between the illumination pattern 410 and the shifted illumination pattern 420, and the like.

[0071] Also, the signal processing unit 150A executes shifted illumination frame group synchronization processing (step ST2160) in parallel with the illumination frame group synchronization processing. In the shifted illumination frame group synchronization processing, the shifted illumination frame group synchronization unit 156 of the signal processing unit 150A associates each point of the received signal corresponding to the shifted illumination pattern 420 with each illumination frame of the illumination frame group output from the illumination frame group holding unit 154.

[0072] The signal processing unit 150A then executes calibration processing (step ST2170). In the calibration processing, the calibration processing unit 157b of the signal processing unit 150A has a function of calibrating the received signal output from the shifted illumination frame group synchronization unit 156. Specifically, the calibration processing unit 157b is offset removal, correction if the illumination power is different between the illumination pattern 410 and the shifted illumination pattern 420, and the like.

[0073] The signal processing unit 150A then executes signal integration processing (step ST2180). In signal integration processing, the signal integration unit 158 of the signal processing unit 150A concatenates the illumination frame groups output from both the illumination frame group synchronization unit 155 and the shifted illumination frame group synchronization unit 156 with the received signal, respectively, to create an integrated received signal and an integrated illumination frame group.

[0074] The signal processing unit 150A then executes image reconstruction processing (step ST2190). In the image reconstruction processing, the image reconstruction unit 159 of the signal processing unit 150A performs image reconstruction processing on the integrated received signal and the integrated illumination frame group output from the signal integration unit 158 to generate a two-dimensional image of the measurement target 200.

[0075] The signal processing unit 150A then executes image output processing (step ST2200). In the image output processing, the image output unit 160 of the signal processing unit 150A outputs the image generated by the image reconstruction unit 159.

[0076] The image acquisition device 100A then proceeds to end determination processing (step ST2210). In the end determination processing, a control unit (not shown) of the image acquisition device 100A determines whether to end the processing of the image acquisition device 100A. The control unit (not shown) determines whether to end the processing of the image acquisition device 100A, for example, according to an end command from the outside or an execution program. If the control unit (not shown) determines not to end the processing of the image acquisition device 100A (step ST2210 “NO”), the process proceeds to the process of step ST2110, and repeated processing is performed from the process of step ST2110. If the control unit (not shown) determines to end the processing of the image acquisition device (step ST2210 “YES”), the image acquisition device ends the processing.

[0077] A processing example of the image acquisition device according to Embodiment 2 of the present disclosure will be described in more detail. FIGS. 7 and 8 are operation explanatory diagrams of Embodiment 1.

[0078] FIG. 7 is a diagram for explaining the operation related to the acquisition of a reception signal in the image acquisition device A according to Embodiment 2 of the present disclosure. In response to the control from the illumination control unit 111, the illumination system unit 110 irradiates the illumination pattern 410 or the shifted illumination pattern 420. The switching is periodic, and the illumination pattern 410 and the shifted illumination pattern 420 are switched at regular intervals. Here, the shifted illumination pattern 420 is obtained by shifting the illumination pattern 410 by one section in the vertical direction α, but the pattern itself is the same. Since it is shifted by one section, the sections in the vertical direction α of the illumination pattern 410 and the shifted illumination pattern 420 match. That is, the relative position in the horizontal direction between the measurement target and the illumination pattern, and the relative position in the horizontal direction between the measurement target and the shifted illumination pattern do not change.

[0079] The measurement target 200 moves horizontally on the illumination pattern 410 or the shifted illumination pattern 420. Then, as the measurement target 200 moves, the apparent illumination pattern (= illumination frame) irradiated on the measurement target 200 changes. Although the illumination pattern is single, since the illumination frame changes, processing equivalent to general SPI can be performed.

[0080] Even when the position of the measurement target 200 is the same, the apparent illumination pattern (= illumination frame) irradiated on the measurement target 200 is different between the illumination pattern 410 and the shifted illumination pattern 420. Therefore, compared with the case where only the illumination pattern 410 is used, the number of illumination frames can be doubled. As described above, the shifted illumination pattern 420 is only a shifted version of the illumination pattern 410, and ultimately only a single illumination pattern is being used. Therefore, only one fixed pattern generation unit 113 is sufficient, and dynamic control and driving such as that of a spatial light modulator are not required.

[0081] The scattered light and reflected light at each position of the measurement target 200 are converted into a continuous electrical signal by the reception optical system 131 and the single-pixel light detection unit 132, and transmitted to the signal processing unit 150A. "Reflected light and scattered light" represents reflected light, scattered light, or both reflected light and scattered light.

[0082] FIG. 8 is a diagram for explaining the processing related to the signal processing unit 150A in the image acquisition device 100A according to Embodiment 2 of the present disclosure.

[0083] First, the AD conversion unit 151 converts the electrical signal from the single-pixel light detection unit 132 into a digital signal (step ST2110).

[0084] Next, the time synchronization unit 152 associates the digital signal output by the AD conversion unit 151 with the position of the measurement target 200 (= illumination pattern 410 section number) (step ST2120). At the time when it is output to the AD conversion unit 151, the correspondence between the time axis of the signal and the position of the measurement target 200 is unknown. For example, by providing characteristic patterns at the left and right ends in the horizontal direction of the illumination pattern 410 and identifying the timing when the measurement target 200 passes through this characteristic pattern in the received signal, the time axis can be associated with the position of the measurement target 200.

[0085] Next, the signal separation unit 153 separates the output signal of the time synchronization unit 152 into two parts: a part corresponding to the illumination pattern 410 and a part corresponding to the shifted illumination pattern 420 (step ST2130). By using the pattern switching timing information transmitted from the illumination control unit 111, it can be determined which of the illumination pattern 410 and the shifted illumination pattern 420 each region in the same output signal corresponds to.

[0086] The two separated signals output from the signal separation unit 153 are associated with the corresponding illumination frame groups by the illumination frame group synchronization unit 155 and the shifted illumination frame group synchronization unit 156, respectively (step ST2140, step ST2160). Usually, the separated signal is a continuous signal, but only the data points (= hereinafter simply referred to as data points) corresponding to each illumination frame included in the illumination frame group are taken by synchronization with the illumination frame group, resulting in a discrete signal. At this time, for example, noise can be reduced by averaging the points around the corresponding data points.

[0087] The data points output from the illumination frame group synchronization unit 155 and the shifted illumination frame group synchronization unit 156 are calibrated by the calibration processing unit 157 (step ST2150, step ST2170). In addition to removing the offset, since the wavelengths of the illumination pattern 410 and the shifted illumination pattern 420 are different, if there are differences in the output power of the light source and the efficiency of the optical system, they are corrected.

[0088] The illumination frame groups (500A, 500B) corresponding to the illumination pattern 410 and the shifted illumination pattern 420, and the corresponding data points output from the calibration processing unit 157 are integrated by the signal integration unit 158 (step ST2180). Specifically, the illumination frame groups and the data points are concatenated with each other, and new illumination frame groups and data points are generated. By performing this process, illumination frame groups and data points that are twice as many as when only the illumination pattern 410 is used can be obtained. This process is possible because the sections of the illumination pattern 410 and the shifted illumination pattern 420 match. If the sections do not match (= the shift amount is not an integer multiple of the section size), the positions of the measurement target 200 will be shifted by substantially less than one section between the illumination frame corresponding to the illumination pattern 410 and the illumination frame corresponding to the shifted illumination pattern 420. As a result, problems such as failure in the image reconstruction process or blurring of the measurement target 200 in the output image will occur.

[0089] In order to acquire an image with high precision by SPI, it is necessary to secure a sufficient number of illumination frames. In the SPI using a single illumination pattern described in Non-Patent Document 2, since there is a correspondence relationship between the number of illumination frames and the horizontal size of the illumination pattern, there is a problem that the horizontal size of the illumination pattern increases when acquiring an image with high precision. On the other hand, in the present disclosure, as described above, while using a single illumination pattern, the number of substantial illumination frames can be increased by shifting the illumination pattern in the vertical direction. As a result, even when the horizontal size of the illumination pattern is reduced, high-precision image acquisition becomes possible.

[0090] Using the illumination frame group newly generated by the signal integration unit 158 and the corresponding data points, the image reconstruction unit 159 reconstructs the image 600 of the measurement target 200 (step ST2190, step ST2200). The process of image acquisition by SPI can be described as follows. y = Ax ···(1) Here, "y" in Equation (1) is the measurement value vector (Nx1, data points corresponding to the illumination frame group), "x" is the measurement target vector (M 2 x1, obtained by rearranging and vectorizing the elements of the measurement target 200 (resolution MxM)), and "A" is the measurement matrix (NxM 2 ). Note that "N" is the number of illumination frames included in the illumination frame group, and "M" is the resolution of one side of the measurement target 200. If the illumination frames are I1, I2, ···, I N , the measurement matrix A can be expressed as Equation (2) below. A = [vec[I1] vec[I2] ··· vec[I N t ···(2) Here, in Equation (2), "vec[ ]" is an operator for rearranging and vectorizing the elements of a matrix, and "[ t " represents transpose. In SPI, it is necessary to solve the inverse problem of estimating the measurement target "x" using the known "y" and "A".

[0091] As methods for solving the above, methods similar to ghost imaging that obtain the correlation between data points and frame groups, and methods similar to compressive sensing that transform the above equation into an optimization problem are known. The method of compressive sensing has the feature that it can reproduce the image of the measurement target even under the condition that the data points are limited, such as N < M 2 , and is particularly effective in a configuration such as the present disclosure where the number of data points (= number of illumination frames) is limited by the illumination pattern size.

[0092] [Effects according to Embodiment 2]

[0093] ​ By configuring as in this embodiment, since the number of illumination frames is doubled, the horizontal size of the illumination pattern can be reduced, and the size of the apparatus can be miniaturized.

[0094] Since the above can be performed with only a single illumination pattern, the pattern generation unit that generates the illumination pattern can be configured without including dynamic driving and control such as a spatial light modulator. Also, the illumination frame is increased by a factor of two with a configuration that does not require a mechanical drive unit, and these contribute to miniaturization, cost reduction, and high reliability of the apparatus.

[0095] An increase in the number of illumination frames can also be realized, for example, by using two pattern generators that generate different illumination patterns. However, according to this embodiment, since only one pattern generator is required, the apparatus configuration can be simplified compared to the above configuration.

[0096] The image acquisition apparatus of the present disclosure according to this embodiment is further configured as follows, for example. The illumination system unit includes a light source unit, a pattern generation unit that imparts a two-dimensional pattern to the light emitted from the light source unit, an illumination optical system that projects the light imparted with the two-dimensional pattern by the pattern generation unit onto the measurement target, an illumination pattern shift unit that shifts the illumination pattern generated by the illumination optical system, and is provided with The pattern generation unit is configured with a static structure that imparts a single two-dimensional pattern to the light emitted from the light source unit, The illumination system unit irradiates while switching between the illumination pattern and one or more shifted illumination patterns obtained by shifting the illumination pattern by the illumination pattern shift unit in accordance with the passage of time. An image acquisition apparatus characterized by the above.

[0097] [Other Modification Examples]

[0098] The pattern multiplexing unit 114 may be installed between the receiving optical system 131 and the single-pixel light detection unit 132. Even in this case, the same functions and effects as those of the present embodiment can be obtained. Also, a relay optical system may be inserted between the pattern multiplexing unit 114 and the single-pixel light detection unit 132.

[0099] For switching between the illumination pattern 410 and the shift illumination pattern 420, not only the wavelength of light but also the polarization of light can be used. For example, by configuring the time-division light source unit 112 with a laser light source and a polarization switch, and the pattern multiplexing unit 114 with an element (birefringent crystal) that gives different refractive angles according to polarization, and controlling the illumination control unit 111 to switch the polarization of the output light from the time-division light source unit 112, the same functions and effects as those of the present embodiment can be obtained.

[0100] The shift direction of the shift illumination pattern 420 does not have to be the vertical direction. When a shift vector representing the magnitude and direction of the shift is defined, by setting the vertical component of the vector to an integer multiple of the section and the horizontal component of the vector to a magnitude corresponding to the movement amount of the measurement target 200, the deviation due to the horizontal movement of the measurement target 200 during the shift of the illumination pattern can be compensated.

[0101] The shift illumination pattern 420 may be provided with a mechanism that can easily adjust the shift direction. This can be realized, for example, by attaching a mechanism capable of adjusting the tilt angle and the rotation angle around the optical axis of the wavelength dispersion element inside the pattern multiplexing unit 114 to the outside of the housing of the illumination system unit 110. Since the moving speed of the measurement target 200 may vary depending on the installation environment, having the above mechanism enables corresponding to any moving speed of the measurement target 200.

[0102] Embodiment 3. Embodiment 3 will be described. In Embodiment 3, among the components according to Embodiment 3, for components that are the same as those in Embodiment 1 or Embodiment 2 that have already been described, the same names and the same reference numerals are given, and duplicate descriptions are omitted as appropriate.

[0103] [Configuration] A configuration example of the image acquisition device according to Embodiment 3 of the present disclosure will be described. FIG. 9 is a diagram showing a configuration example of the image acquisition device 100B according to Embodiment 3 of the present disclosure, and a configuration example when the image acquisition device 100B is applied to a measurement system. Hereinafter, for the same components as those in Embodiments 1 and 2, the same names and the same or similar symbols are given, and the configuration will be described focusing on the differences from Embodiments 1 and 2. The image acquisition device 100B shown in FIG. 9 includes an illumination system unit 110B, a reception unit 130B, and a signal processing unit 150B.

[0104] The illumination system unit 110B in the image acquisition device 100B includes an illumination control unit 111B, a time-division multiplexed light source unit 112B, a fixed pattern generation unit 113, a pattern multiplexing unit 114, and an illumination optical system 115. The illumination system unit 110B simultaneously irradiates the illumination pattern and one or more shifted illumination patterns obtained by shifting the illumination pattern by the illumination pattern shift unit (fixed pattern generation unit 113).

[0105] The time-division multiplexed light source unit 112B has a function of always irradiating the fixed pattern generation unit 113 with two lights having different wavelengths. The time-division multiplexed light source unit 112B constitutes the light source unit of the present disclosure.

[0106] The fixed pattern generation unit 113 has a function of imparting a spatial modulation pattern to the light irradiated from the time-division multiplexed light source unit 112B. The fixed pattern generation unit 113 constitutes the pattern generation unit of the present disclosure. The pattern generation unit (fixed pattern generation unit 113) imparts a two-dimensional pattern to the light emitted from the light source unit (time-division multiplexed light source unit 112B). The pattern generation unit (fixed pattern generation unit 113) is configured by a static structure that imparts a single two-dimensional pattern to the light emitted from the light source unit (time-division multiplexed light source unit 112B).

[0107] The pattern multiplexing unit 114 has a function of simultaneously generating an illumination pattern 410 and a shifted illumination pattern 420 in which the illumination pattern 410 is shifted, according to the wavelength of light, by imparting wavelength-dependent refraction to the light that has passed through the fixed pattern generation unit 113. The pattern multiplexing unit 114 constitutes the illumination pattern shift unit of the present disclosure. The illumination pattern shift unit (pattern multiplexing unit 114) shifts the illumination pattern generated by the illumination optical system. The illumination pattern shift unit (pattern multiplexing unit 114) simultaneously generates and outputs the illumination pattern 410 and the shifted illumination pattern 420. The pattern generation unit (pattern multiplexing unit 114) is configured by a static structure that imparts the single two-dimensional pattern to the light emitted from the light source unit (time-division multiplexed light source unit 112B).

[0108] The illumination optical system 115 projects the light to which the two-dimensional pattern has been imparted by the pattern generation unit (pattern multiplexing unit 114) onto the measurement target.

[0109] The receiving unit 130B includes a receiving optical system 131, a single-pixel light detection unit 132B-1, a single-pixel light detection unit 132B-2, and a pattern separation unit 133.

[0110] The receiving optical system 131 has a function of transmitting the illumination pattern 410 and the shifted illumination pattern 420 reflected and scattered by the measurement target 200 to the pattern separation unit 133.

[0111] The pattern separation unit 133 has a function of separating and transmitting the illumination pattern 410 to the single-pixel light detection unit 132B-1 and the shifted illumination pattern 420 to the single-pixel light detection unit 132B-2 according to the wavelength of the incident light. Specifically, it is composed of a beam splitter or the like having transmission characteristics / reflection characteristics dependent on the wavelength.

[0112] The single-pixel light detection unit 132B-1 and the single-pixel light detection unit 132B-2 have the function of converting the light transmitted from the pattern separation unit 133 into an electrical signal. The single-pixel light detection unit 132B-1 and the single-pixel light detection unit 132B-2 are so-called photodetectors, and those made of Si in the visible wavelength band and those made of InGaAs or Ge in the short infrared wavelength band are generally used.

[0113] That is, the receiving unit 130B of the present disclosure includes a plurality of the single-pixel photodetectors (single-pixel light detection unit 132B-1 and single-pixel light detection unit 132B-2) that receive the light from the measurement target when the illumination pattern and the shifted illumination pattern are irradiated on the measurement target by the illumination system unit 110B. The plurality of single-pixel photodetectors separately detect the illumination pattern and the shifted illumination pattern.

[0114] The signal processing unit 150B has the function of receiving the electrical signals from the single-pixel light detection unit 132B-1 and the single-pixel light detection unit 132B-2, and reproducing (hereinafter, "reproducing" may also be described as "generating" or "reconstructing") and outputting an image of the measurement target 200.

[0115] FIG. 10 is a diagram showing a configuration example of the illumination system unit 110B in the image acquisition device 100B according to Embodiment 3 of the present disclosure. Hereinafter, for the same components as those in Embodiments 1 and 2, the same names and the same or similar symbols are given, and the configuration will be described focusing on the differences from Embodiments 1 and 2.

[0116] The single-color laser 112-1B and the single-color laser 112B-2 are laser light sources having different output wavelengths and continuously output light.

[0117] The beam combiner 112B-3 has the function of combining the light output from the single-color laser 112B-1 and the single-color laser 112B-2.

[0118] Prism 114-1 has a function of separating the propagation directions of the lights of monochromatic laser 112B-1 and monochromatic laser 112B-2. By configuring in this way, the illumination pattern 410 and the shift illumination pattern 420 can be generated simultaneously.

[0119] FIG. 11 is a diagram showing a configuration example of the signal processing unit 150B in the image acquisition device 100B according to Embodiment 3 of the present disclosure. Hereinafter, for the components similar to those in Embodiments 1 and 2, the same names and the same or similar symbols are given, and the configuration will be described focusing on the differences from Embodiments 1 and 2.

[0120] The AD conversion unit 151 has a function of converting the electrical signals from the single-pixel light detection unit 132B-1 and the single-pixel light detection unit 132B-2 into digital signals.

[0121] The illumination frame group synchronization unit 155 has a function of associating each point of the received signal corresponding to the illumination pattern 410 output from the time synchronization unit 152 with each illumination frame of the illumination frame group output from the illumination frame group holding unit 154.

[0122] The shift illumination frame group synchronization unit 156 has a function of associating each point of the received signal corresponding to the shift illumination pattern 420 output from the time synchronization unit 152 with each illumination frame of the illumination frame group output from the illumination frame group holding unit 154.

[0123] [Operation] A processing example of the image acquisition device according to Embodiment 3 of the present disclosure will be described. FIGS. 12 and 13 are operation explanatory diagrams of Embodiment 2. Hereinafter, for the components the same as those in Embodiments 1 and 2, the same names and the same or similar symbols are given, and the configuration will be described focusing on the differences from Embodiments 1 and 2.

[0124] FIG. 12 is a diagram for explaining the operation related to the acquisition of the received signal in the image acquisition device 100B according to Embodiment 3 of the present disclosure. The difference from Embodiment 2 is only that the illumination pattern 410 and the shift illumination pattern 420 are simultaneously irradiated from the illumination system unit 110B. At each position of the measurement object 200, the scattered light and reflected light from the illumination pattern 410 are converted into continuous electrical signals by the single-pixel light detection unit 132B-1, and the scattered light and reflected light from the shift illumination pattern 420 are converted into continuous electrical signals by the single-pixel light detection unit 132B-2, and then transmitted to the signal processing unit 150B.

[0125] Also, since the illumination pattern 410 and the shift illumination pattern 420 are simultaneously irradiated, it is not necessary to consider the horizontal shift of the shift illumination pattern 420 for compensating for the movement of the measurement object 200.

[0126] FIG. 13 is a diagram for explaining the processing related to the signal processing unit 150B in the image acquisition device 100B according to Embodiment 3 of the present disclosure. The difference from Embodiment 2 is that, at the time of input to the signal processing unit 150B, the received signals corresponding to the illumination pattern 410 and the shift illumination pattern 420 are separated. Therefore, there is no processing corresponding to the signal separation unit 153 or the timing synchronization processing by the illumination control unit 111, and only the processing corresponding to the AD conversion unit 151 and the time synchronization unit 152 is performed on each received signal. Therefore, the detailed description of the processing from step ST3310 to step ST3400 shown in FIG. 13 is omitted.

[0127] [Effects according to Embodiment 3]

[0128] By configuring as in this embodiment, compared with Embodiment 1, it is not necessary to synchronize the pattern switching timing, so there is an advantage that signal processing becomes easier.

[0129] Furthermore, since both patterns are continuously irradiated simultaneously, it is easy to increase the exposure time, and there is also an advantage that the signal-to-noise ratio is improved.

[0130] In addition, since the illumination pattern 410 and the shift illumination pattern 420 are irradiated simultaneously, there is no need to consider the horizontal shift of the shift illumination pattern 420 for compensating for the movement of the measurement target 200.

[0131] The image acquisition device of the present disclosure according to the present embodiment is further configured as follows, for example. The illumination system unit includes a light source unit, a pattern generation unit that imparts a two-dimensional pattern to the light emitted from the light source unit, an illumination optical system that projects the light with the two-dimensional pattern imparted by the pattern generation unit onto the measurement target, an illumination pattern shift unit that shifts the illumination pattern generated by the illumination optical system, and is provided with The receiving unit includes a plurality of the single-pixel photodetectors that receive light from the measurement target when the illumination pattern and the shift illumination pattern are irradiated onto the measurement target by the illumination system unit. The pattern generation unit is configured by a static structure that imparts a single two-dimensional pattern to the light emitted from the light source unit. The illumination system unit irradiates the illumination pattern and one or more shift illumination patterns obtained by shifting the illumination pattern by the illumination pattern shift unit simultaneously. The plurality of single-pixel photodetectors respectively detect the illumination pattern and the shift illumination pattern separately. The image acquisition device according to claim 1, characterized in that. Accordingly, the present disclosure can provide an image acquisition device that does not need to synchronize the pattern switching timing, and the like. Furthermore, by applying the above configuration to the above image acquisition method, the present disclosure exhibits the same effects as the above effects.

[0132] [Other Modification Examples]

[0133] Similar to Embodiment 2, the pattern multiplexing unit 114 may be installed after the receiving optical system 131.

[0134] Similar to Embodiment 2, not only the wavelength of light but also the polarization of light can be used to generate the shift illumination pattern 420. For example, with two laser light sources having orthogonal polarizations in the time-division light source unit 112B, an element (birefringent crystal) that gives different refraction angles to the pattern multiplexing unit 114 according to polarization, and the pattern separation unit 133 is configured with a polarization beam splitter or the like, functions and effects equivalent to those of this embodiment can be obtained.

[0135] Embodiment 4. Embodiment 4 will be described. In Embodiment 4, among the components according to Embodiment 4, for components similar to those in Embodiment 1, Embodiment 2, or Embodiment 3 that have already been described, the same names and the same reference numerals are given, and duplicate descriptions are omitted as appropriate.

[0136] [Configuration] A configuration example of the image acquisition device according to Embodiment 4 of the present disclosure will be described. FIG. 14 is a diagram showing a configuration example of the image acquisition device 100C according to Embodiment 4 of the present disclosure, and a configuration example when the image acquisition device 100C is applied to a measurement system. Hereinafter, for the same components as in Embodiments 1, 2, and 3, the same names and the same or similar reference numerals are given, and the configuration will be described focusing on the differences from Embodiments 1, 2, and 3.

[0137] The time-division light source unit 112C has a function of irradiating the fixed pattern generation unit 113 while temporally switching three lights with different wavelengths based on the control from the illumination control unit 111C.

[0138] The pattern multiplexing unit 114 has a function of switching the modulation pattern transferred to the measurement object 200 to any one of the illumination pattern 410, the shift illumination pattern 420 (the second illumination pattern, the first shift illumination pattern), and the shift illumination pattern 430 (the third illumination pattern, the second shift illumination pattern) according to the wavelength of light by imparting wavelength-dependent refraction to the light that has passed through the fixed pattern generation unit 113. Here, the number of illumination patterns is arbitrarily set to three for convenience, but as shown in the specific configuration of the illumination system unit 110C, it can be four or more.

[0139] The shift illumination pattern 430 is obtained by shifting the illumination pattern 410 in a direction perpendicular to the movement of the measurement object 200 (hereinafter simply referred to as the perpendicular direction) by the pattern multiplexing unit 114. Here, a shift amount corresponding to two sections of the illumination pattern 410 is assumed. By setting the shift amount in this way, the vertical sections of the shift illumination pattern 430, the shift illumination pattern 420, and the illumination pattern 410 coincide. Since it is important that the vertical sections of these three illumination patterns coincide, the shift amounts of the shift illumination pattern 430 and the shift illumination pattern 420 only need to be an integer multiple of the section size, and are not limited to two sections.

[0140] The number of vertical sections of the illumination pattern 410 is obtained by adding the shift amount (two sections in this embodiment) or more to the number of pixels in the vertical direction of the output image from this apparatus. Thereby, it is ensured that the measurement object 200 is also within the illumination pattern in the shift illumination pattern 430. When this apparatus outputs an image with a resolution of 32x32, the resolution of the illumination pattern 410 is, for example, 34x231. In this case, the number of illumination frames is 200.

[0141] FIG. 15 is a diagram showing a first configuration example of the illumination system unit 110C in the image acquisition apparatus 100C according to Embodiment 4 of the present disclosure. Hereinafter, for the same components as those in Embodiments 1, 2, and 3, the same names and the same or similar symbols are given, and the configuration will be described focusing on the differences from Embodiments 1, 2, and 3.

[0142] The multi-wavelength laser 112C-1 is a laser light source capable of outputting light of three or more different wavelengths, and has a function of emitting light at a specified wavelength at a timing specified by the illumination control unit 111C.

[0143] The prism 114-1 has a function of separating the propagation direction of light according to the wavelength of the output light of the multi-wavelength laser 112C-1. By configuring in this way, the illumination pattern 410, the shift illumination pattern 420, and the shift illumination pattern 430 can be switched in a configuration that does not include a mechanical drive unit.

[0144] By changing the control signal to the multi-wavelength laser 112C-1 output from the illumination control unit 111C, it is also possible to realize four or more types of illumination patterns.

[0145] FIG. 16 is a diagram showing a second configuration example of the illumination system unit 110C in the image acquisition device 100C according to Embodiment 4 of the present disclosure. Hereinafter, for the same components as those in Embodiments 1, 2, and 3, the same names and the same or similar symbols are given, and the configuration will be described focusing on the differences from Embodiments 1, 2, and 3.

[0146] The single-color laser 112C-2 is a laser light source having a single output wavelength and continuously outputs light.

[0147] The illumination pattern mask 113-1 has a function of imparting a spatial modulation pattern to the light from the single-color laser 112C-2.

[0148] The illumination pattern mask moving unit 116 has a function of moving the illumination pattern mask 113-1 in one axis or two axes according to a control signal from the illumination control unit 111C-2. By configuring in this way, the illumination pattern 410, the shift illumination pattern 420, and the shift illumination pattern 430 can be switched. The illumination pattern mask moving unit 116 may be configured to be controllable from the outside of the image acquisition device 100C, for example. The illumination pattern mask moving unit 116 constitutes the pattern moving unit of the present disclosure. The pattern moving unit (illumination pattern mask moving unit 116) changes the shift direction of the shift illumination pattern.

[0149] It is also possible to realize four or more types of illumination patterns by changing the control signal from the illumination control unit 111C-2 to the illumination pattern mask moving unit 116.

[0150] FIG. 17 is a diagram showing a configuration example of the signal processing unit 150C in the image acquisition device 100C according to Embodiment 4 of the present disclosure. Hereinafter, for the same components as those in Embodiments 1, 2, and 3, the same names and the same or similar symbols are given, and the configuration will be described focusing on the differences from Embodiments 1, 2, and 3.

[0151] The signal separation unit 153 has a function of determining and separating signals corresponding to the illumination pattern 410, the shift illumination pattern 420, and the shift illumination pattern 430 from the received signal from the time synchronization unit 152 using the timing information from the illumination control unit 111. Further, it also has a function of transmitting the part corresponding to the illumination pattern 410 to the illumination frame group holding unit 154, the part corresponding to the shift illumination pattern 420 to the shift illumination frame group synchronization unit 156C-1, and the part corresponding to the shift illumination pattern 430 to the shift illumination frame group synchronization unit 156C-2, respectively.

[0152] The illumination frame group holding unit 154 has a function of holding the illumination frame groups corresponding to the illumination pattern 410, the shift illumination pattern 420, and the shift illumination pattern 430.

[0153] Similar to the shift illumination frame group synchronization unit 156, the shift illumination frame group synchronization unit 156C-1 has a function of associating each point of the received signal corresponding to the shift illumination pattern 420 output from the time synchronization unit 152 with each illumination frame of the illumination frame group output from the illumination frame group holding unit 154. The shift illumination frame group synchronization unit 156C-2 has a function of associating each point of the received signal corresponding to the shift illumination pattern 430 with each illumination frame of the illumination frame group output from the illumination frame group holding unit 154.

[0154] The calibration processing unit 157 has a function of calibrating the received signals output from the illumination frame group holding unit 154, the shift illumination frame group synchronization unit 156C-1, and the shift illumination frame group synchronization unit 156C-2. Specifically, it includes removing offsets, correcting if the illumination power is different for each pattern, etc.

[0155] The signal integration unit 158 concatenates the illumination frame group and the received signal output from the illumination frame group holding unit 154, the shift illumination frame group synchronization unit 156C-1, and the shift illumination frame group synchronization unit 156C-2 respectively, and creates an integrated received signal and an integrated illumination frame group.

[0156] [Operation] A processing example of the image acquisition device according to the fourth embodiment of the present disclosure will be described. FIG. 18 is a diagram for explaining the operation related to the acquisition of the received signal in the image acquisition device 100C according to the fourth embodiment of the present disclosure. Hereinafter, the configuration will be described focusing on the differences from the first, second, and third embodiments.

[0157] The difference from other embodiments is that the number of patterns output from the illumination system unit 110C has increased. The scattered light / reflected light corresponding to the illumination pattern 410, the shift illumination pattern 420, and the shift illumination pattern 430 is irradiated. The scattered light / reflected light from the illumination pattern 410 is converted into a continuous electrical signal by the single pixel light detection unit 132, and the scattered light / reflected light from the shift illumination pattern 420 is converted into a continuous electrical signal by the single pixel light detection unit 132B-2, and then transmitted to the signal processing unit 150C. In the signal processing unit 150C, after each illumination pattern is separated, the same processing as in the second embodiment is performed.

[0158] [Effects of the Fourth Embodiment]

[0159] By configuring as in this embodiment, since the number of substantial illumination frames is tripled, the horizontal size of the illumination pattern can be further reduced.

[0160] Also, by simply changing the signal from the illumination control unit 111, the number of illumination patterns can be increased to four or more without changing the device configuration.

[0161] When configuring the illumination system unit 110 as shown in FIG. 15, the illumination pattern can be shifted in a form that does not include a mechanical drive unit. This contributes to cost reduction, miniaturization, and high reliability of the device.

[0162] When configuring the illumination system unit 110 as shown in FIG. 16, since the prism 114-1 can be removed, the optical system can be simplified. Furthermore, when driving the illumination pattern mask moving unit 116 in two axes, there is an advantage that the tilt angle in the shift direction of the illumination pattern can be adjusted only by changing the control signal to the illumination pattern mask moving unit 116.

[0163] The image acquisition device of the present disclosure according to this embodiment is further configured as follows, for example. Comprising a pattern moving unit that changes the shift direction of the shift illumination pattern An image acquisition device characterized by this.

[0164] [Other Modification Examples] When configuring the illumination system unit 110 as shown in FIG. 15, the multi-wavelength laser 112C-1 may have a function of continuously changing the output wavelength. In that case, by finely adjusting the output wavelength, the positions of the shift illumination pattern 420 and the shift illumination pattern 430 can be changed, so there is an advantage that the requirement for the installation accuracy of the pattern multiplexing unit 114 can be lowered.

[0165] Embodiment 5. Embodiment 5 will be described. In Embodiment 5, among the components according to Embodiment 5, for components having the same configuration as those in Embodiment 1, Embodiment 2, Embodiment 3, or Embodiment 4, which have already been described, the same names and the same reference numerals are assigned, and overlapping descriptions are omitted as appropriate.

[0166] [Configuration] A configuration example of an image acquisition device according to Embodiment 5 of the present disclosure will be described. FIG. 19 is a diagram showing a configuration example of an image acquisition device 100D according to Embodiment 5 of the present disclosure and a configuration example when the image acquisition device 100D is applied to a measurement system. Hereinafter, for the same components as in Embodiments 1, 2, 3, and 4, the same names and the same or similar symbols are assigned, and the configuration will be described focusing on the differences from Embodiments 1, 2, 3, and 4.

[0167] The image acquisition device 100D irradiates the measurement target 200 with four illumination patterns: an illumination pattern 410, a shift illumination pattern 420 (second illumination pattern, first shift illumination pattern), a shift illumination pattern 430 (third illumination pattern, second shift illumination pattern), and a shift illumination pattern 440 (fourth illumination pattern, third shift illumination pattern). The shift illumination pattern 420, the shift illumination pattern 430, and the shift illumination pattern 440 are shifted from the illumination pattern 410 at equal intervals, where the shift interval is half of the section of the illumination pattern 410. Therefore, the shift illumination pattern 420, the shift illumination pattern 430, and the shift illumination pattern 440 are obtained by shifting the illumination pattern 410 by 1 / 2, 1, and 3 / 2 sections in the vertical direction.

[0168] The single-pixel light detection unit 132 has a function of converting the light collected by the receiving optical system 131 into an electrical signal, and acquires signals at intervals of 1 / 8 of the time when the measurement target 200 passes through one pixel of the illumination pattern 410. As a result, in addition to the case where the measurement target 200 is on the illumination pattern 410, the shifted illumination pattern 420, the shifted illumination pattern 430, and the shifted illumination pattern 440 (hereinafter referred to as cases 1 to 4), when the measurement target 200 is shifted horizontally by 1 / 2 section from the illumination pattern 410, the shifted illumination pattern 420, the shifted illumination pattern 430, and the shifted illumination pattern 440 (hereinafter referred to as cases 5 to 8), signals are also acquired. By configuring in this way, an effect of doubling the resolution in the vertical and horizontal directions can be obtained by the processing in the signal processing unit 150.

[0169] FIG. 20 is a diagram showing a configuration example of a signal processing unit 150D in the image acquisition device 100D according to Embodiment 5 of the present disclosure. Hereinafter, for the same components as those in Embodiments 1, 2, 3, and 4, the same names and the same or similar symbols are attached, and the configuration will be described focusing on the differences from Embodiments 1, 2, 3, and 4.

[0170] The signal separation unit 153 has a function of determining and separating signals corresponding to cases 1 to 8 from the received signal from the time synchronization unit 152 using the timing information from the illumination control unit 111D. Further, it also has a function of transmitting the signals corresponding to each case to the illumination frame group synchronization unit 155 or the shifted illumination frame group synchronization unit 156D (156Dn: n = 1, 2, 3, 4, 5, 6, 7).

[0171] The signal integration unit 158D (158Dn: n = 1, 2, 3, 4) concatenates the input plurality of illumination frame groups and the plurality of received signals respectively, and creates an integrated received signal and an integrated illumination frame group. Embodiment 5 includes four signal integration units 158, which integrate Case 1 and Case 3, Case 2 and Case 4, Case 5 and Case 7, and Case 6 and Case 8. The corresponding illumination patterns of the integrated cases are shifted by one section in the vertical direction. Also, taking Case 1 as a reference, Case 2 is shifted by 1 / 2 section in the vertical direction, Case 5 is shifted by 1 / 2 section in the horizontal direction, and Case 7 is shifted by 1 / 2 section in both the vertical and horizontal directions.

[0172] The image reconstruction unit 159D (159Dn: n = 1, 2, 3, 4) is connected to the subsequent stage of each signal integration unit 158D (158Dn: n = 1, 2, 3, 4), and performs image reconstruction processing on the integrated received signal and the integrated illumination frame group output from the signal integration unit 158 (158Dn: n = 1, 2, 3, 4) to generate a two-dimensional image of the measurement object 200 (a total of 4 sheets). Each two-dimensional image output by the image reconstruction unit 159 (159Dn: n = 1, 2, 3, 4) is shifted by 1 / 2 pixel as described above.

[0173] The signal processing unit 150D further includes a resolution improvement unit 161 that performs resolution improvement processing on the received signal to improve the resolution of the image based on the received signal.

[0174] The resolution improvement unit 161 has a function of receiving the four two-dimensional images output from the image reconstruction unit 159 (159Dn: n = 1, 2, 3, 4) and outputting a resolution-improved image having a resolution twice as high as these images in both the horizontal and vertical directions. Since the four input images are shifted by 1 / 2 pixel in both the horizontal and vertical directions, the resolution is improved by integrating these images using a so-called sub-pixel shift method.

[0175] [Operation] A processing example of the image acquisition device according to Embodiment 5 of the present disclosure will be described. Hereinafter, the configuration will be described focusing on the differences from Embodiments 1, 2, 3, and 4. FIG. 21 is a diagram for explaining the operation related to the acquisition of a reception signal in the image acquisition apparatus 100D according to Embodiment 5 of the present disclosure. FIG. 22 is a diagram for explaining the processing related to the signal processing unit 150D in the image acquisition apparatus 100D according to Embodiment 5 of the present disclosure.

[0176] The differences from Embodiment 4 are that the number of patterns output from the illumination system unit 110D has increased, the vertical shift amount of the illumination pattern is 1 / 2 section, and eight reception signals are acquired while the measurement target 200 is one section. Since the details of the processing contents from step ST4110 to step ST4420 shown in FIG. 22 are the same as the processing contents already described, the different processing contents will be described below. Assuming that the horizontal section shift amount based on the illumination pattern 410 is ΔX and the vertical section shift amount is ΔY, signals are acquired in the following eight cases. Case 1: Section shift (ΔX, ΔY) = (0, 0) (= illumination pattern 410) Case 2: Section shift (ΔX, ΔY) = (0, 1 / 2) (= shifted illumination pattern 420) Case 3: Section shift (ΔX, ΔY) = (0, 1) (= shifted illumination pattern 430) Case 4: Section shift (ΔX, ΔY) = (0, 3 / 2) (= shifted illumination pattern 440) Case 5: Section shift (ΔX, ΔY) = (1 / 2, 0) (= illumination pattern 410 with section shift (ΔX, ΔY) = (1 / 2, 0)) Case 6: Section shift (ΔX, ΔY) = (1 / 2, 1 / 2) (= shifted illumination pattern 420 with section shift (ΔX, ΔY) = (1 / 2, 0)) Case 7: Section shift (ΔX, ΔY) = (1 / 2, 1) (= shifted illumination pattern 430 with section shift (ΔX, ΔY) = (1 / 2, 0)) Case 8: Section shift (ΔX, ΔY) = (1 / 2, 3 / 2) (= shifted illumination pattern 440 with section shift (ΔX, ΔY) = (1 / 2, 0)) Each time the measurement target 200 moves by one section, signals are acquired in the above eight cases. Therefore, by performing the same signal separation process as in the first embodiment, the received signals corresponding to each case are separated (step STST4130).

[0177] Case 1 and Case 3 are obtained by shifting the illumination pattern 410 by one section in the vertical direction. Similar to the second embodiment, they can be used to increase the substantial number of illumination frames by signal integration processing (step ST4360). The same applies to Case 2 and Case 4, Case 5 and Case 7, and Case 6 and Case 8. On the other hand, Case 2 and Case 4 are shifted by (ΔX, ΔY) = (0, 1 / 2) with respect to Case 1 and Case 3. Case 5 and Case 7, and Case 6 and Case 8 are also shifted by (ΔX, ΔY) = (1 / 2, 0) and (1 / 2, 1 / 2). Therefore, when image reconstruction is performed using these cases, output images shifted by the above amounts are obtained with respect to the output images in Case 1 and Case 3. Therefore, a total of four images taken with a half-section shift are obtained (step ST4390).

[0178] Since the four output images are so-called sub-pixel shifted images, an image with a resolution that is doubled in both the horizontal and vertical directions can be newly created by integrating the images through resolution improvement processing (resolution enhancement processing: step ST4410). If necessary, deconvolution processing or the like may be performed to improve the image quality.

[0179] In normal sub-pixel shift processing, a 1 / 2 pixel shift is sufficient, so there is no reasonable reason to set a shift amount exceeding one pixel such as in Case 3, Case 4, Case 7, and Case 8. On the other hand, in this embodiment, in addition to improving the resolution by sub-pixel shift, a process for increasing the number of illumination frames is performed. Therefore, it is characteristic to acquire signals even with a shift amount exceeding one pixel.

[0180] Below, the conditions for the above operation to hold are organized.

[0181] As a prerequisite, in a state where the image acquisition device 100D is installed so as to measure the measurement object 200 to be moved, the shift direction of the illumination pattern is the vertical direction α with respect to the movement direction 250 of the measurement object. Let the movement speed of the measurement object 200 be v, the vertical section interval of the illumination pattern 410 be d y , the horizontal section interval of the illumination pattern 410 be d x , the length on the measurement object corresponding to the vertical pixel interval of the two-dimensional image output from the signal processing unit 150 be d’ y , the length on the measurement object corresponding to the horizontal pixel interval of the two-dimensional image output from the signal processing unit 150 be d’ x be defined as such.

[0182] At this time, the improvement degree ρ of the vertical resolution y is ρ y =d y / d’ y , and the coefficient ρ representing the improvement degree of the horizontal resolution x be ρ x =d x / d’ x becomes. If there is no improvement in resolution, then d y =d’ y , dx=d’ x , so ρ y =ρ x =1.

[0183] Let the number of illumination patterns to be shifted be N. The total number of patterns including the illumination pattern 410 is N + 1. The total number of illumination patterns is restricted by the condition for improving the vertical resolution and the condition for obtaining the effect of increasing the number of illumination frames. First, in order to improve the resolution by ρ y only, it is necessary that N + 1 >= ρ y . For example, in order to double the vertical resolution, at least two types of shift amounts (ΔX, ΔY) = (0, 0) and (0, 1 / 2) are required. Furthermore, in order to obtain an increase in the illumination frames, for each shift amount, it is necessary to shift them by one section in the vertical direction. Since the minimum increase in the number of illumination frames is 2, N + 1 >= 2 * ρ yIt becomes. Therefore, the condition for the number of lighting patterns to be shifted for the present embodiment to hold is N >= 2 * ρ y -1 is obtained.

[0184] Let the vertical shift interval of the lighting pattern be Δd y and the maximum shift distance be d y,max be set. The vertical shift interval is related to the improvement degree of the vertical resolution. For example, when improving the resolution by a factor of 2 (ρ y = 2), Δd y <= d y / 2 is required. Generalizing this gives Δd y <= d y / ρ y as a constraint. On the other hand, as for d y,max , since the product of the pattern interval d y and the number of patterns N is required to be at least the minimum, using the number of patterns N, d y,max >= Δd y * N becomes a constraint.

[0185] In Configuration 5 of the present embodiment, ρ y = ρ x = 2, N = 3, Δd y = 1 / 2 * d y , d y,max = 3 / 2 * d y and the above constraints are satisfied. On the other hand, when only aiming to increase the resolution of the resolution, N = 1, d y,max = 1 / 2 * d y is sufficient and there is no reasonable reason to configure and operate to satisfy the above constraint conditions.

[0186] Note that in the configuration of Embodiment 5 of the present invention, ρ y = ρ x = 2 was set, but if configured so that the above is satisfied even when ρ y = ρ x > 2, the resolution improvement effect and the lighting frame increase effect can be obtained. When ρ y = ρ x = 1, N = 1, Δd y = d y,maxIf we set it to 1, it will match the conditions of Embodiment 1, and furthermore, the above-mentioned constraint conditions will be satisfied.

[0187] Note that the minimum number of samples required for improving the resolution and increasing the number of illumination frames is ρ times (N + 1) while the measurement target 200 moves one section. When switching the illumination pattern and acquiring signals at equal intervals, the switching period Δt of the illumination pattern x should satisfy the constraint that Δt p is Δt p <=(d x / v) / (ρ x *(N + 1)), and the signal acquisition period Δt s should also satisfy the constraint that Δt s <=(d x / v) / (ρ x *(N + 1)).

[0188] Furthermore, constraint conditions regarding the number of sections of the illumination pattern are also specified. Let the number of sections in the vertical direction of the illumination pattern 410 be M y , the number of sections in the horizontal direction be M x , the number of pixels in the vertical direction of the two-dimensional image output from the signal processing unit be M' y and the number of pixels in the horizontal direction be M' x . The illumination pattern 410 should have a number of sections such that the measurement target 200 is within the illumination pattern 410 even when the illumination pattern 410 is shifted by d y,max . The number of sections corresponding to d y,max is d y,max / d y , and the number of sections corresponding to the measurement target 200 is M' y with the resolution improvement of M' y / ρ y . Therefore, M y should satisfy the relationship M y >=M' y / ρ y +d y,max / dy. Also, from the perspective of ensuring a sufficient number of illumination frames for M x , M x should satisfy the relationship M x >>M' x / ρ.

[0189] In a normal SPI, from the viewpoint of maximizing the resolution of the output image, M y and M' y / ρ y There is no reasonable reason not to match them. In the present disclosure, since the illumination pattern is shifted, it is necessary to satisfy the above constraints.

[0190] [Effects according to Embodiment 5]

[0191] By configuring as in the present embodiment, while maintaining the effect of increasing the substantial number of illumination frames, the effect of improving the resolution of the output image can also be obtained.

[0192] The image acquisition device of the present disclosure according to the present embodiment is further configured, for example, as follows. An illumination system unit that irradiates a measurement target with an illumination pattern provided with a two-dimensional pattern formed using a plurality of sections, and a shifted illumination pattern obtained by shifting the illumination pattern along the irradiation surface; A receiving unit that receives light from the measurement target when the illumination pattern and the shifted illumination pattern are irradiated on the measurement target by the illumination system unit via a single-pixel photodetector; A signal processing unit that acquires a reception signal based on the light received by the receiving unit, and generates a two-dimensional image of the measurement target based on a change in the reception signal when the measurement target passes over the illumination pattern and a change in the reception signal when the measurement target passes over the shifted illumination pattern; and includes The illumination system unit includes a light source unit; a pattern generation unit that imparts a two-dimensional pattern to the light emitted from the light source unit; an illumination optical system that projects the light imparted with the two-dimensional pattern by the pattern generation unit onto the measurement target; an illumination pattern shift unit that shifts the illumination pattern generated by the illumination optical system; and includes The pattern generation unit is configured by a static structure that imparts the single two-dimensional pattern to the light emitted from the light source unit. The illumination system unit irradiates while switching between the illumination pattern and one or more shifted illumination patterns obtained by shifting the illumination pattern by the illumination pattern shift unit over time. An image acquisition device, In a state where the image acquisition device is installed so as to measure the moving measurement target, the shift direction of the illumination pattern is a direction perpendicular to the moving direction of the measurement target. The illumination pattern and the shifted illumination pattern irradiated by the illumination system unit are When the moving speed of the measurement target is v, The section interval in the direction perpendicular to the moving direction of the measurement target in the illumination pattern is d y , The section interval in the horizontal direction with respect to the moving direction of the measurement target in the illumination pattern is d x , The length on the measurement target corresponding to the pixel interval in the vertical direction of the two-dimensional image output from the signal processing unit is d' y , The length on the measurement target corresponding to the pixel interval in the horizontal direction of the two-dimensional image output from the signal processing unit is d' x , Coefficient ρ y is ρ y = d y / d' y , Coefficient ρ x is ρ x = d x / d' x When defined as The number N of the shifted illumination patterns satisfies the condition N >= 2 * ρ y - 1, The vertical shift interval Δd of the shifted illumination pattern y is such that Δd y <= d y / ρ y satisfies the relationship The maximum shift distance d in the vertical direction of the shift illumination pattern y,max is d y,max >=Δd y and satisfies the relationship of *N, where N is the number of signal acquisitions while the measurement target passes through one section of the illumination pattern s is N s >=ρ x *(N + 1) times, characterized by an image acquisition device

[0193] The image acquisition device of the present disclosure according to the present embodiment is further configured as follows, for example The illumination pattern irradiated by the illumination system unit has M sections in the vertical direction of the illumination pattern y , has M sections in the horizontal direction of the illumination pattern x , the number of pixels in the vertical direction of the two-dimensional image output from the signal processing unit is M' y , the number of pixels in the horizontal direction of the two-dimensional image output from the signal processing unit is M' x When defined as the number of sections M in the vertical direction of the illumination pattern y is M y >=M' y / ρ y +d y,max / d y and satisfies the relationship of the number of sections M in the horizontal direction of the illumination pattern x is M x >>M' x / ρ x and satisfies the relationship of characterized by an image acquisition device

[0194] The image acquisition device of the present disclosure according to the present embodiment is further configured as follows, for example The coefficient ρ yand the coefficient ρ x either of which is 2 or more, The signal processing unit performs resolution improvement processing for improving the resolution of an image based on the received signal on the received signal. An image acquisition device characterized by this.

[0195] The image acquisition device of the present disclosure according to this embodiment is further configured as follows, for example. The horizontal relative position between the measurement target and the illumination pattern and the horizontal relative position between the measurement target and the shifted illumination pattern do not change with the switching between the illumination pattern and the shifted illumination pattern. An image acquisition device characterized by this.

[0196] The image acquisition device of the present disclosure according to this embodiment is further configured as follows, for example. An illumination system unit that irradiates a measurement target with an illumination pattern to which a two-dimensional pattern formed using a plurality of sections is applied, and a shifted illumination pattern obtained by shifting the illumination pattern along the irradiation surface; A receiving unit that receives light from the measurement target when the illumination pattern and the shifted illumination pattern are irradiated on the measurement target by the illumination system unit via a single-pixel photodetector; A signal processing unit that acquires a reception signal based on the light received by the reception unit and generates a two-dimensional image of the measurement target based on the change in the reception signal when the measurement target passes over the illumination pattern and the change in the reception signal when the measurement target passes over the shifted illumination pattern; and includes The illumination system unit a light source unit, a pattern generation unit that applies a two-dimensional pattern to the light emitted from the light source unit, An illumination optical system that projects light with a two-dimensional pattern imparted by the pattern generation unit onto the measurement target, An illumination pattern shift unit that shifts the illumination pattern generated by the illumination optical system, and is provided with, The receiving unit includes a plurality of the single-pixel photodetectors that receive light from the measurement target when the illumination pattern and the shifted illumination pattern are irradiated onto the measurement target by the illumination system unit, The pattern generation unit is configured by a static structure that imparts a single two-dimensional pattern to the light emitted from the light source unit, The illumination system unit simultaneously irradiates the illumination pattern and one or more shifted illumination patterns obtained by shifting the illumination pattern by the illumination pattern shift unit, The plurality of single-pixel photodetectors separately detect the illumination pattern and the shifted illumination pattern, An image acquisition device, In a state where the image acquisition device is installed so as to measure the moving measurement target, the shift direction of the illumination pattern is a direction perpendicular to the moving direction of the measurement target, The illumination pattern and the shifted illumination pattern irradiated by the illumination system unit are, The moving speed of the measurement target is v, The sectional interval in the direction perpendicular to the moving direction of the measurement target in the illumination pattern is d y , The sectional interval in the horizontal direction with respect to the moving direction of the measurement target in the illumination pattern is d x , The length on the measurement target corresponding to the pixel interval in the vertical direction of the two-dimensional image output from the signal processing unit is d' y , The length on the measurement target corresponding to the pixel interval in the horizontal direction of the two-dimensional image output from the signal processing unit is d' x , Coefficient ρ y is ρ y = d y / d' y , Coefficient ρx is ρ x = d x / d’ x、 When defined as the number N of the shift illumination patterns satisfies N >= 2 * ρ y and satisfies the condition of -1 the vertical shift interval Δd of the shift illumination patterns y is Δd y <= d y / ρ y and satisfies the relationship of the maximum shift distance d in the vertical direction of the shift illumination patterns y,max is d y,max >= Δd y * N and satisfies the relationship of An image acquisition device characterized by this

[0197] The image acquisition device of the present disclosure according to this embodiment is further configured as follows, for example The illumination pattern irradiated by the illumination system unit is the number of vertical sections of the illumination pattern is M y , the number of horizontal sections of the illumination pattern is M x , the number of pixels in the vertical direction of the two-dimensional image output from the signal processing unit is M' y , the number of pixels in the horizontal direction of the two-dimensional image output from the signal processing unit is M' x , When defined as the number of vertical sections M of the illumination pattern y is M y >= M' y / ρ y + d y,max / d y and satisfies the relationship of the number of vertical sections M of the illumination pattern x is M x >> M' x / ρ x and satisfies the relationship of An image acquisition device characterized by the following.

[0198] The image acquisition device of the present disclosure according to this embodiment is further configured as follows, for example. The coefficient ρ y and the coefficient ρ x is either 2 or more, The signal processing unit performs a resolution improvement process on the received signal to improve the resolution of an image based on the received signal. An image acquisition device characterized by the following.

[0199] Here, the hardware configuration for realizing the functions of the present disclosure will be described. FIG. 23 is a diagram showing a first example of a hardware configuration for realizing the functions according to the configuration of the present disclosure. FIG. 24 is a diagram showing a second example of a hardware configuration for realizing the functions according to the configuration of the present disclosure. In the image acquisition devices 100, 100A, 100B, 100C, 100D of the present disclosure, in particular, the illumination control units 111, 111A, 111B, 111C, 111C-1, 111C-2, 111D, and the signal processing units 150, 150A, 150B, 150C, 150D are each realized by hardware as shown in FIG. 23 or FIG. 24.

[0200] In the image acquisition devices 100, 100A, 100B, 100C, 100D of the present disclosure, in particular, the illumination control units 111, 111A, 111B, 111C, 111C-1, 111C-2, 111D, and the signal processing units 150, 150A, 150B, 150C, 150D are each composed of, for example, a processor 10001, a memory 10002, an input / output interface 10003, and a communication circuit 10004 as shown in FIG. 23. The processor 10001 and the memory 10002 are, for example, those installed in a computer. The memory 10002 stores a program for causing the computer to function as the lighting control units 111, 111A, 111B, 111C, 111C-1, 111C-2, 111D, the signal processing units 150, 150A, 150B, 150C, 150D, and a control unit (not shown). By the processor 10001 reading and executing the program stored in the memory 10002, the functions of the lighting control units 111, 111A, 111B, 111C, 111C-1, 111C-2, 111D, the signal processing units 150, 150A, 150B, 150C, 150D, and the control unit (not shown) are realized. Also, a storage unit (not shown) is realized by the memory 10002 or another memory (not shown). Also, a communication unit (not shown) is realized by the communication circuit 10004.

[0201] The processor 10001 is, for example, one using a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), a microprocessor, a microcontroller, or a DSP (Digital Signal Processor). The memory 10002 may be a non-volatile or volatile semiconductor memory such as a RAM (Random Access Memory), a ROM (Read Only Memory), an EPROM (Erasable Programmable ROM), an EEPROM (Electrically Erasable Programmable Read Only Memory), or a flash memory, or may be a magnetic disk such as a hard disk or a flexible disk, or may be an optical disk such as a CD (Compact Disc) or a DVD (Digital Versatile Disc), or may be a magneto-optical disk. The processor 10001, the memory 10002, or the communication circuit 10004 are connected in a state where they can transmit data to each other. Also, the processor 10001, the memory 10002, and the communication circuit 10004 are connected in a state where they can transmit data to and receive data from other hardware via the input / output interface 10003.

[0202] Alternatively, in the image acquisition devices 100, 100A, 100B, 100C, 100D, particularly the functions of the illumination control units 111, 111A, 111B, 111C, 111C-1, 111C-2, 111D, the signal processing units 150, 150A, 150B, 150C, 150D, and a control unit (not shown) may be implemented by a dedicated processing circuit 20001 as shown in FIG. 24.

[0203] The processing circuit 20001 uses, for example, a single circuit, a composite circuit, a programmed processor, a parallel-programmed processor, an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), an FPGA (Field-Programmable Gate Array), a SoC (System-on-a-Chip), or a system LSI (Large-Scale Integration), etc. Also, a storage unit (not shown) is realized by the memory 20002 or another memory (not shown). The memory 20002 may be a non-volatile or volatile semiconductor memory such as a RAM (Random Access Memory), ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable Read Only Memory), or flash memory, or it may be a magnetic disk such as a hard disk or a flexible disk, or it may be an optical disk such as a CD (Compact Disc) or a DVD (Digital Versatile Disc), or it may be a magneto-optical disk. Also, a communication unit (not shown) is realized by the communication circuit 20004. The processing circuit 20001, the memory 20002, and the communication circuit 20004 are connected in a state where they can transmit data to each other. Also, the processing circuit 20001, the memory 20002, and the communication circuit 20004 are connected in a state where they can transmit data to other hardware via the input / output interface 20003. Note that in the image acquisition devices 100, 100A, 100B, 100C, 100D, the functions of the illumination control units 111, 111A, 111B, 111C, 111C-1, 111C-2, 111D, the signal processing units 150, 150A, 150B, 150C, 150D, and the control unit (not shown) may be realized by separate processing circuits, or may be realized by a combined processing circuit. Similarly, in the passenger monitoring device 300A, the functions of the video acquisition unit 301A, the motion determination unit 302A, and the control unit (not shown) may be realized by separate processing circuits, or may be realized by a combined processing circuit. Similarly, in the server device 600E, the functions of the operation information collection unit 601E and the control unit (not shown) may be realized by separate processing circuits, or may be realized by a combined processing circuit.

[0204] Alternatively, in the image acquisition devices 100, 100A, 100B, 100C, 100D, some of the functions of, in particular, the illumination control units 111, 111A, 111B, 111C, 111C-1, 111C-2, 111D, the signal processing units 150, 150A, 150B, 150C, 150D, and the control unit (not shown) may be realized by the processor 10001 and the memory 10002, and the remaining functions may be realized by the processing circuit 20001.

[0205] Note that within the scope of this disclosure, free combinations of each embodiment, modifications of any component of each embodiment, or omissions of any component of each embodiment are possible.

Industrial Applicability

[0206] This disclosure can increase the number of apparent illumination patterns (illumination frames) while suppressing an increase in the size of the illumination pattern when acquiring a two-dimensional image of a measurement object using a single illumination pattern. Therefore, for example, it is suitable for use in a measurement device or the like that acquires a two-dimensional image of a measurement object using a single illumination pattern for measurement.

Description of Reference Numerals

[0207] 100, 100A, 100B, 100C, 100D Image acquisition devices, 110, 110A, 110B, 110C, 110C-1, 110C-2, 110D Lighting system units, 111, 111A, 111B, 111C, 111C-1, 111C-2, 111D Lighting control units, 112A, 112C Time-division multiplexed light source units (light source units), 112A-1, 112B-1 Monochromatic lasers (light source units), 112A-2, 112B-2 Monochromatic lasers (light source units), 112A-3, 112B-3 Beam combiners, 112B Multiplexed light source units, 112C-1 Multi-wavelength lasers, 113 Fixed pattern generation unit (pattern generation unit), 113-1 Lighting pattern mask (pattern generation unit), 114 Pattern multiplexing unit (lighting pattern shift unit), 114-1 Prism (lighting pattern shift unit), 115 Lighting optical system, 115-1 Lighting lens, 116 Lighting pattern mask moving unit (pattern moving unit), 130, 130A, 130B, 130C, 130D Receiving units, 131 Receiving optical system, 132, 132A Single-pixel light detection unit (single-pixel light detection device), 132B-1, 132B-2 Single-pixel light detection units (multiple single-pixel light detection devices) 133 Pattern separation unit, 150, 150A, 150B, 150C, 150D Signal processing units, 151 AD conversion unit, 152 Time synchronization unit, 153 Signal separation unit, 154 Lighting frame group holding unit, 155 Lighting frame group synchronization unit, 156, 156C-1, 156C-2, 156D(156D n : n = 1, 2, 3, 4, 5, 6, 7) Shift lighting frame group synchronization unit, 157, 157a, 157b, 157c, 157D(157D n : n = 1, 2, 3, 4, 5, 6, 7) Calibration processing unit, 158, 158D(158D n : n = 1, 2, 3, 4) Signal integration unit, 159, 159D(159D n: (n = 1, 2, 3, 4) Image reconstruction unit, 160 Image output unit, 161 Resolution improvement unit, 200 Measurement object, 250 Moving direction of the measurement object, 300 Object drive unit (object drive device), 400 Pattern light, 410 Illumination pattern (first illumination pattern), 420 Shift illumination pattern (first shift illumination pattern) (second illumination pattern), 430 Shift illumination pattern (second shift illumination pattern) (third illumination pattern), 440 Shift illumination pattern (third shift illumination pattern) (fourth illumination pattern), 500, 5001, 5002, 5003, 5004, 5005, 5006, 5007, 500A, 500B Illumination frames, 600 Images, 10001 Processor, 10002 Memory, 10003 Input / output interface, 10004 Communication circuit, 20001 Processing circuit, 20002 Memory, 20003 Input / output interface, 20004 Communication circuit.

Claims

1. An illumination system unit that irradiates a measurement target with an illumination pattern provided with a two-dimensional pattern formed using a plurality of sections, and a shifted illumination pattern obtained by shifting the illumination pattern along an irradiation surface; A receiving unit that receives light from the measurement target when the illumination pattern and the shifted illumination pattern are irradiated onto the measurement target by the illumination system unit, via a single-pixel photodetector; A signal processing unit that acquires a reception signal based on the light received by the receiving unit, and generates a two-dimensional image of the measurement target based on a change in the reception signal when the measurement target passes over the illumination pattern and a change in the reception signal when the measurement target passes over the shifted illumination pattern; An image acquisition device comprising the above.

2. The illumination system unit includes: A light source unit; A pattern generation unit that applies a two-dimensional pattern to the light emitted from the light source unit; An illumination optical system that projects the light provided with the two-dimensional pattern by the pattern generation unit onto the measurement target; An illumination pattern shift unit that shifts the illumination pattern generated by the illumination optical system; And is provided with: The pattern generation unit is configured by a static structure that applies a single two-dimensional pattern to the light emitted from the light source unit; The illumination system unit irradiates the illumination pattern and one or more shifted illumination patterns obtained by shifting the illumination pattern by the illumination pattern shift unit while switching according to the passage of time. The image acquisition device according to claim 1, characterized in that.

3. In a state where the image acquisition device is installed so as to measure the moving measurement target, the shift direction of the illumination pattern is a direction perpendicular to the moving direction of the measurement target. The illumination pattern and the shifted illumination pattern irradiated by the illumination system unit are: When the moving speed of the measurement target is v, The section interval in the direction perpendicular to the moving direction of the measurement target in the illumination pattern is d ｙ , The horizontal section interval with respect to the moving direction of the measurement target in the illumination pattern is d ｘ , The length on the measurement target corresponding to the pixel interval in the vertical direction of the two-dimensional image output from the signal processing unit is d' ｙ , The length on the measurement target corresponding to the pixel interval in the horizontal direction of the two-dimensional image output from the signal processing unit is d' ｘ , Coefficient ρ y is ρ ｙ = d ｙ / d' ｙ , Coefficient ρ ｘ is ρ ｘ = d ｘ / d' ｘ As defined by, The number N of the shift illumination patterns satisfies the condition of N >= 2 * ρ - 1 ｙ and meets the condition of - 1 The vertical shift interval Δd of the shift illumination pattern ｙ is Δd ｙ ≤ d ｙ / ρ ｙ satisfies the relationship The maximum shift distance d in the vertical direction of the shift illumination pattern ｙ，ｍａｘ is d ｙ，ｍａｘ >= Δd ｙ * N, satisfying the relationship The number of signal acquisitions N during the measurement target passing through one section of the illumination pattern ｓ is N ｓ >= ρ ｘ * (N + 1) times, satisfying the relationship The image acquisition device according to claim 2, characterized in that.

4. The illumination pattern irradiated by the illumination system unit is: The number of vertical sections of the illumination pattern is M ｙ , The number of horizontal sections of the illumination pattern is M ｘ , The number of pixels in the vertical direction of the two-dimensional image output from the signal processing unit is M' ｙ , The number of pixels in the horizontal direction of the two-dimensional image output from the signal processing unit is M' ｘ When defined by, The number of vertical sections M of the illumination pattern ｙ is M ｙ >= M' ｙ / ρ ｙ + d ｙ，ｍａｘ / d ｙ satisfies the relationship The number of horizontal sections M of the illumination pattern ｘ is M ｘ >> M' ｘ / ρ ｘ satisfying the relationship The image acquisition device according to claim 3, characterized in that.

5. the coefficient ρ ｙ and the coefficient ρ ｘ is either 2 or more, The signal processing unit performs a resolution improvement process on the reception signal to improve the resolution of an image based on the reception signal. The image acquisition device according to claim 4, characterized in that.

6. The relative position in the horizontal direction between the measurement target and the illumination pattern, and the relative position in the horizontal direction between the measurement target and the shifted illumination pattern do not change with the switching between the illumination pattern and the shifted illumination pattern, The image acquisition device according to claim 4 or claim 5, characterized in that.

7. An image acquisition device comprising a pattern moving unit that changes the shift direction of the shifted illumination pattern, The image acquisition device according to claim 6, characterized in that.

8. The illumination system unit A light source unit, A pattern generation unit that imparts a two-dimensional pattern to the light emitted from the light source unit, An illumination optical system that projects the light with the two-dimensional pattern imparted by the pattern generation unit onto the measurement target, An illumination pattern shift unit that shifts the illumination pattern generated by the illumination optical system, Comprising The receiving unit includes a plurality of the single-pixel photodetectors that receive light from the measurement target when the illumination pattern and the shifted illumination pattern are irradiated on the measurement target by the illumination system unit, The pattern generation unit is configured by a static structure that imparts a single two-dimensional pattern to the light emitted from the light source unit, The illumination system unit simultaneously irradiates the illumination pattern and one or more shifted illumination patterns obtained by shifting the illumination pattern by the illumination pattern shift unit, The plurality of single-pixel photodetectors respectively detect the illumination pattern and the shifted illumination pattern separately, The image acquisition device according to claim 1, characterized in that.

9. In a state where the image acquisition device is installed to measure the moving measurement target, the shift direction of the illumination pattern is a direction perpendicular to the moving direction of the measurement target, The illumination pattern and the shifted illumination pattern irradiated by the illumination system unit When the moving speed of the measurement target is v, The section interval in the direction perpendicular to the moving direction of the measurement target in the illumination pattern is d ｙ , The horizontal section interval with respect to the moving direction of the measurement target in the illumination pattern is d ｘ , The length on the measurement target corresponding to the pixel interval in the vertical direction of the two-dimensional image output from the signal processing unit is d' ｙ , The length on the measurement target corresponding to the pixel interval in the horizontal direction of the two-dimensional image output from the signal processing unit is d' ｘ , Coefficient ρ ｙ is ρ ｙ = d ｙ / d' ｙ , Coefficient ρ ｘ is ρ ｘ = d ｘ / d' ｘ、 When defined as The number N of the shift illumination patterns satisfies the condition N >= 2 * ρ - 1 ｙ and The vertical shift interval Δd of the shift illumination pattern ｙ is Δd ｙ ≤ d ｙ / ρ ｙ and satisfies the relationship The maximum shift distance d in the vertical direction of the shift illumination pattern ｙ，ｍａｘ is d ｙ，ｍａｘ >= Δd ｙ and satisfies the relationship of *N The image acquisition device according to claim 8, characterized in that.

10. The illumination pattern irradiated by the illumination system unit Let M be the number of vertical sections of the illumination pattern ｙ , Let the number of horizontal sections of the illumination pattern be M ｘ , Let M' be the number of pixels in the vertical direction of the two-dimensional image output from the signal processing unit ｙ , Let M' be the number of pixels in the horizontal direction of the two-dimensional image output from the signal processing unit ｘ , When defined as The number of vertical divisions M of the illumination pattern ｙ is M ｙ >= M' ｙ / ρ ｙ + d ｙ，ｍａｘ / d ｙ satisfies the relationship The number of vertical sections M of the illumination pattern ｘ is M ｘ >> M' ｘ / ρ ｘ satisfying the relationship The image acquisition device according to claim 9, characterized in that.

11. the coefficient ρ ｙ and the coefficient ρ ｘ is either 2 or more, The signal processing unit performs a resolution improvement process on the received signal to improve the resolution of the image based on the received signal, The image acquisition device according to claim 10, characterized in that.

12. An image acquisition method by an image acquisition device, The image acquisition device irradiates a measurement target with an illumination pattern provided with a two-dimensional pattern formed using a plurality of sections, and a shift illumination pattern obtained by shifting the illumination pattern along the pattern plane. The image acquisition device receives light from the measurement target irradiated with the illumination pattern and the shift illumination pattern through a single-pixel photodetector. The image acquisition device acquires a reception signal based on the light received through the single-pixel photodetector, and generates a two-dimensional image of the measurement target based on a change in the reception signal when the measurement target passes over the illumination pattern and a change in the reception signal when the measurement target passes over the shift illumination pattern. An image acquisition method.

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