Imaging device, image generation method, and program

Abstract

An imaging device (100) is provided with: a light source unit (131); a digital micromirror device (133) that modulates light output by the light source unit; an interference light detection unit (150) that detects interference light, which results from interference between scattered light or reflected light and reference light, the scattered light or the reflected light resulting from scattering or reflection by an object under measurement in a state in which the object under measurement is irradiated with modulated light, which results from modulation by the digital micromirror device, and the reference light being the modulated light when the object under measurement is not irradiated therewith; an interference light detection control unit (110) that instructs that the optical path length of the reference light interfering with the scattered light or the reflected light is to be changed and that instructs a plurality of prestored modulation patterns to the digital micromirror device for each optical path length changed; and an image generation unit (170) that generates a three-dimensional image of the object under measurement on the basis of pattern information indicating each of the plurality of modulation patterns and interference light detected individually by using modulated light modulated with each of the plurality of modulation patterns for each optical path length.

Description

Imaging device, image generation method, and program

[0001] The disclosed technology relates to an imaging technology for generating a three-dimensional image of an object to be measured.

[0002] Among the technologies for generating an image of an object to be measured (imaging technologies), there is a technology that combines ghost imaging technology and optical coherence tomography (OCT) technology to generate a three-dimensional image of the object by three-dimensionally imaging not only the front of the object but also the inside and rear of the object (Patent Document 1). The "object imaging device" in Patent Document 1 is composed of a spatial light modulator (SLM: Spatial Light Modulator) that uses liquid crystal to temporally and spatially fluctuate and modulate laser light output from a laser light source as a light source, a camera or a computing unit for acquiring a reference signal when the laser light modulated by the SLM is not irradiated onto the object to be measured, and many other optical components.

[0003] International Publication No. 2017 / 187484 (WO2017 / 187484)

[0004] The "object imaging device" of Patent Document 1 mentioned above has a problem in that the device is large in size due to the large number of devices and parts that make up the entire device.

[0005] The present disclosure is intended to solve the above-mentioned problems, and aims to make an apparatus for generating a three-dimensional image of a measurement object smaller than conventional apparatuses.

[0006] The imaging device of the present disclosure includes: a light source unit; a digital micromirror device that modulates light output by the light source unit; an interference light detection unit that detects interference light, which is light generated when modulated light, which is light modulated by the digital micromirror device, is irradiated onto the object to be measured, and reference light, which is the modulated light when not irradiated onto the object to be measured; an interference light detection control unit that commands the digital micromirror device to change the optical path length of the reference light that interferes with the scattered light or reflected light, and commands the digital micromirror device to use multiple pre-stored modulation patterns for each changed optical path length; and an image generation unit that generates a three-dimensional image of the object to be measured based on pattern information indicating each of the multiple modulation patterns and the interference light detected using modulated light modulated by each of the multiple modulation patterns for each optical path length.

[0007] According to the present disclosure, it is possible to achieve an effect of making a device for generating a three-dimensional image of a measurement object smaller than conventional devices.

[0008] FIG. 1 is a diagram illustrating an example configuration of an imaging device according to a first embodiment of the present disclosure. FIG. 2 is a diagram illustrating a schematic diagram of the concept of the imaging device according to the present disclosure. FIG. 3 is a diagram illustrating a schematic diagram of an image restoration algorithm of the imaging device according to the present disclosure. FIG. 4 is a flowchart illustrating an example of processing of the imaging device according to the present disclosure. FIG. 5 is a diagram illustrating an example configuration of an imaging device according to a second embodiment of the present disclosure. FIG. 6 is a diagram illustrating a first example of a hardware configuration for realizing functions according to the configuration of the present disclosure. FIG. 7 is a diagram illustrating a second example of a hardware configuration for realizing functions according to the configuration of the present disclosure.

[0009] In order to explain the present disclosure in more detail, embodiments of the present disclosure will be described below with reference to the accompanying drawings.

[0010] First Embodiment In a first embodiment, a configuration example of a basic form for realizing the imaging technology of the present disclosure will be described.

[0011] An example configuration of an imaging device according to a first embodiment of the present disclosure will be described. Fig. 1 is a diagram illustrating an example configuration of an imaging device according to a first embodiment of the present disclosure. The imaging device 100 shown in Fig. 1 includes an interference light detection control unit 110, an optical transmission unit 130, an interference light detection unit 150, and an image generation unit 170.

[0012] The optical transmitting unit 130 outputs light that is the basis for obtaining scattered light or reflected light from the object to be measured 200 and reference light for generating an image. The optical transmitting unit 130 shown in FIG. 1 includes a light source unit 131 and a digital micromirror device (DMD) 133.

[0013] A light source according to the performance required of the imaging device is used for the light source unit 131. For example, by using a superluminescent diode (SLD) for the light source unit 131, collimated light with a uniform wavefront can be used, and the imaging device can be configured with good cost-effectiveness.

[0014] The digital micromirror device (DMD) 133 modulates the light output by the light source unit 131. The digital micromirror device (DMD) 133 is composed of multiple micromirrors, and can control each of the multiple micromirrors to be on or off. The digital micromirror device (DMD) 133 is controlled by a command including a value indicating whether each micromirror is on or off. The digital micromirror device (DMD) 133 can randomly modulate the phase of incident light.

[0015] The interference light detection unit 150 detects interference light, which is light obtained by interference between scattered light or reflected light by the object to be measured 200 in a state in which modulated light, which is light modulated by the digital micromirror device 133, is irradiated onto the object to be measured 200, and reference light, which is the modulated light when not irradiated onto the object to be measured 200. The interference light detection unit 150 shown in FIG. 1 is configured to include a light splitting and light combining unit 151, a reference mirror unit 153, and a detection unit 155.

[0016] The light splitting and light combining unit 151 splits the light modulated by the digital micromirror device (DMD) 133. The light splitting and light combining unit 151 also combines scattered light, which is modulated light scattered by the object to be measured 200, or reflected light, which is modulated light reflected by the object to be measured 200, with light reflected by the reference mirror 153a of the reference mirror unit 153. The light splitting and light combining unit 151 is configured, for example, by a beam splitter. In this case, the beam splitter receives modulated light, which is light modulated by the digital micromirror device 133, and splits the modulated light into light directed toward the object to be measured 200 (which can also be expressed as a "sample arm") and light directed toward the reference mirror unit 153 (which can also be expressed as a "reference arm"), and combines the scattered light or reflected light with the reference light.

[0017] The reference mirror unit 153 reflects the modulated light to generate reference light. The reference mirror unit 153 can also change the optical path length in response to a command. The reference mirror unit 153 shown in FIG. 1 includes a reference mirror 153a and an optical path length adjustment mechanism 153b. The reference mirror 153a functions to reflect modulated light when not irradiating the object under measurement 200 and return it to the light splitting and light combining unit 151 as reference light. The optical path length adjustment mechanism 153b changes the optical path length of the reference light in response to a command from the interference light detection control unit ("optical path length b"). The optical path length adjustment mechanism 153b is configured to move the reference mirror 153a in the same direction as the optical axis of the modulated light received by the reference mirror 153a ("variation amount a").

[0018] The detection unit 155 detects interference light, which is light resulting from the convergence and interference of the scattered light or the reflected light with the reference light. Specifically, for example, the detection unit 155 detects interference light, which is light resulting from the convergence and interference of the scattered light or the reflected light with the reference light. The detection unit 155 detects interference light between the scattered light or the reflected light and the reference light according to the optical path length b, due to interference of light from a position where the optical path lengths of the sample arm and the reference arm are equal. The detection unit 155 detects the interference light using a single-pixel detector. The single-pixel detector detects one pixel. Note that, although a single-pixel detector is used in the description, it may also be configured to detect a smaller number of pixels, as in Patent Document 1.

[0019] The interference light detection control unit 110 controls the detection of interference light by instructing the optical path length and modulation pattern of the interference light transmitted by the optical transmitting unit 130 and detected by the interference light detection unit 150. In other words, the interference light detection control unit 110 controls the measurement position measured by the interference light on the measurement object 200. The interference light detection control unit 110 instructs the digital micromirror device (DMD) 133 to sequentially change the optical path length of the reference light that interferes with the scattered light or the reflected light, and instructs the digital micromirror device (DMD) 133 to sequentially use multiple pre-stored modulation patterns for each changed optical path length. The interference light detection control unit 110 shown in FIG. 1 includes a DMD control unit 111 and an optical path length control unit 113. The DMD control unit 111 controls the digital micromirror device (DMD) 133. The DMD control unit 111 outputs pattern information including a modulation pattern for modulating the light output from the light source unit 131. The pattern information is stored in advance in a storage unit (not shown), and is used sequentially by the DMD control unit 111. The pattern information includes values ​​indicating the on / off status of each micromirror constituting the digital micromirror device (DMD) 133. This makes it easier to program the pattern information than conventional methods. The DMD control unit 111 also issues commands to the digital micromirror device 133 and outputs the pattern information to the image generation unit 170. The optical path length control unit 113 commands the optical path length of the reference light. The optical path length control unit 113 commands the optical path length adjustment mechanism 153b of the reference mirror unit 153 to sequentially change the optical path length b within a measurable range. The interference light detection control unit 110 may be configured to control the on / off of the light output from the light source unit 131 in the optical transmission unit 130. In this case, the interference light detection control unit 110 includes a light source control unit.

[0020] The image generating unit 170 generates a three-dimensional image of the object to be measured 200. The image generating unit 170 generates a three-dimensional image of the object to be measured 200 based on pattern information indicating each of the plurality of modulation patterns and the interference light detected for each optical path length using modulated light modulated with each of the plurality of modulation patterns. The image generating unit 170 shown in FIG. 1 includes an image calculating unit 171, an image temporary storage unit 173, and an image restoring unit 175.

[0021] The image calculation unit 171 calculates an image of the object to be measured 200 based on interference light detected for each optical path length using modulated light modulated by each of the plurality of modulation patterns, based on pattern information indicating each of the plurality of modulation patterns. The image calculated by the image calculation unit 171 corresponds to an image of a cross section at a position of the object to be measured 200 corresponding to each optical path length. When the fluctuation amount a of the changing optical path length b is stored in advance, the image calculation unit 171 calculates an image for each optical path length b that fluctuates according to the pre-stored fluctuation amount a. When the fluctuation amount a of the changing optical path length b is not stored in advance, the image calculation unit 171 can acquire and use the optical path length b or the fluctuation amount a from the optical path length control unit 113 to calculate an image for each optical path length b that fluctuates according to the fluctuation amount a.

[0022] The image temporary storage unit 173 stores and holds the images calculated by the image calculation unit 171. The image temporary storage unit 173 stores an image corresponding to a cross section of the object to be measured 200 and an image corresponding to the rear of the object to be measured 200.

[0023] The image restoration unit 175 reconstructs and restores a three-dimensional image of the object to be measured 200 using all images of the object to be measured 200 stored in the image temporary storage unit 173 during measurement of the object to be measured 200. Note that the image generation process by the image generation unit 170 can use known technology, and therefore further detailed description thereof will be omitted here.

[0024] In addition to the above components, the imaging device 100 also includes a general control unit (not shown), a storage unit (not shown), and a communication unit (not shown). The general control unit (not shown) controls the entire imaging device 100 and each of its components. The general control unit (not shown), for example, starts up the imaging device 100 in response to an external command. The general control unit (not shown) also controls the state of the imaging device 100 (operating state, such as startup, shutdown, or sleep). The storage unit (not shown) stores various data used by the imaging device 100. For example, the storage unit (not shown) stores output (output data) from each component of the imaging device 100 and outputs data requested for transmission or acquisition by each component to the component corresponding to the request. The communication unit (not shown) communicates with external devices. For example, the communication unit (not shown) communicates between the imaging device 100 and a peripheral device (e.g., an input / output device (not shown). For example, if the imaging device 100 and the input / output device are not connected by wire, the communication unit (not shown) functions to communicate between the imaging device 100 and the input / output device. Furthermore, when a terminal device having the functions of the imaging device 100 and a server (server device, cloud server) cooperate to realize the assistance technology of the present disclosure, a communication unit (not shown) has a function of communicating between the terminal device and the server device. The overall control unit (not shown), the storage unit (not shown), and the communication unit (not shown) each have the same functions in the embodiments described below.

[0025] Here, the concept of the imaging technique of the present disclosure will be explained. Fig. 2 is a diagram schematically illustrating the concept of the imaging device of the present disclosure. Fig. 2 shows that the imaging technique of the present disclosure is a combination of the ghost imaging 300 technique and the interferometer 400 technique.

[0026] The ghost imaging 300 technique shown in FIG. 2 uses a plurality of modulation patterns 310 (a plurality of modulation patterns) to irradiate a measured object 320 with light for each modulation pattern 310, receives the light reflected by the measured object 320 to obtain a received signal 330, and obtains irradiation surface information 340 from the correlation between the modulation pattern 310 and the received signal 330.

[0027] The technology of the interferometer 400 shown in Figure 2 divides the light output from a light source 410 into a sample arm and a reference arm, and detects the interference light between the reference light reflected from a mirror 420 on the reference arm side and the light reflected from the object to be measured 430 on the sample arm side while varying the optical path length of the reference light by a variation amount Δz, thereby obtaining cross-sectional information 440 of the object to be measured 430.

[0028] The imaging device 100 shown in Figure 2 combines the technology of ghost imaging 300 and the technology of interferometer 400, modulating the light output by the SLD serving as the light source unit 131 for each modulation pattern using a digital micromirror device (DMD) 133, and splitting the modulated light, which is the modulated light, into a sample arm and a reference arm via a beam splitter serving as the light division and light combination unit 151.The detector serving as the detection unit 155 detects the interference light between the scattered light or reflected light from the object to be measured 200 (the object to be measured 200 is, for example, a cloud, a living body, etc.) on the sample arm side and the reference light, which is the modulated light when not irradiated onto the object to be measured 200, for each optical path length b obtained by changing the optical path length b by a fluctuation amount a, and the image generation unit 170 reconstructs the light intensity 530 of the detected interference light using images of the cross section of the object to be measured 200 at each position corresponding to the optical path length b based on the correlation between the light intensity 530 of the detected interference light and the multiple modulation patterns 510, thereby generating a three-dimensional image of the object to be measured 200.

[0029] Next, an example of the operation of the imaging device according to the first embodiment of the present disclosure will be described. The imaging device 100 operates, for example, as follows.

[0030] Step ST1: Operation from Optical Transmission to Modulation When the imaging device 100 first starts processing, it outputs collimated light with a uniform wavefront from, for example, a superluminescent diode (SLD) serving as the light source unit 131 shown in FIG. 2 to the digital micromirror device (DMD) 133. The imaging device 100 then spatiotemporally modulates the light using the digital micromirror device (DMD) 133 according to a pre-stored modulation pattern, and outputs the modulated light. As a result, the phase of the modulated light is randomly modulated.

[0031] Step ST2: Splitting and Combining Modulated Light The imaging device 100 then causes the modulated light to be incident on a beam splitter serving as the light splitting and light combining unit 151, which splits the modulated light into a sample arm and a reference arm, one after another. As a result, the modulated light, which is light modulated by the digital micromirror device 133, is split into a sample arm and a reference arm, one after another. One of the split modulated lights is scattered or reflected by the object to be measured 200, and the other of the split modulated light is reflected by the reference mirror 153a of the reference mirror unit 153. The light splitting and light combining unit 151 receives the scattered light or reflected light by the object to be measured 200 and the reference light reflected by the reference mirror 153a, and combines the scattered light or reflected light with the reference light.

[0032] Step ST3: Detection of Interfered Light In the imaging device 100, interference occurs when the optical path lengths of the sample arm and the reference arm are approximately equal. The imaging device 100 moves the reference mirror in the optical axis direction so that the optical path length is equal to the optical path length at each depth in the depth direction of the measured object 200 according to each optical path length, and detects the light intensity of the interference light between the reference light and the scattered light or reflected light by the measured object 200 for each depth position of the measured object 200 according to the optical path length using a single detector. The imaging device 100 irradiates each cross section of the measured object 200 with the same light pattern group (plural types of light patterns), and detects the interference light between the reflected light by each slice of the measured object 200 (the minimum measurable slice thickness depends on the spectral width of the SLD) and the reference light using a single detector.

[0033] Step ST4: Image Generation The imaging device 100 generates a three-dimensional image by three-dimensionally reconstructing the internal structure or its rear information of the object 200 using ghost imaging technology that utilizes light intensity correlation (modulation patterns and light intensities for each modulation pattern) in the image generation unit 170 as shown in Fig. 3. This allows the imaging device 100 to perform imaging of a multilayer structure of a scattering medium such as a living body or a laminated film.

[0034] 3 is a diagram illustrating an image restoration algorithm of the imaging device of the present disclosure. In the image restoration algorithm 500 shown in the upper part of FIG. 3, an image of the position of the cross-sectional pattern of the object 520 can be calculated using a modulation pattern 510 (plural modulation patterns) and a light intensity 530 for each pattern indicating the measurement result of the position of the cross-sectional pattern of the object 520. In the image restoration algorithm 500 shown in the lower part of FIG. 3, a ghost imaging process can be performed using a correlation between a light intensity 570 and a pattern 580 using a DMD chip pattern 550 (a modulation pattern formed by the DMD chip) and a light intensity 560 indicating the measurement result of the position of the cross-sectional pattern of the object 520.

[0035] Next, a processing example of the imaging device according to the first embodiment of the present disclosure will be described. Fig. 4 is a flowchart showing an example of processing of the imaging device according to the present disclosure. The processing shown in Fig. 4 is an image generation method performed by the imaging device 100. The imaging device 100 starts the processing shown in Fig. 4 ("Start"), for example, in response to a command operation by a user, an external imaging start command, or in accordance with a pre-stored program.

[0036] The imaging device 100 then executes a light source control process (step ST1010). In the light source control process, the interference light detection control unit 110 of the imaging device 100 commands the light source unit 131 of the optical transmission unit 130 to output light to the digital micromirror device 133. This causes the light source unit 131 to output light.

[0037] The imaging apparatus 100 then executes an optical path length initial value selection process (step ST1020 ("optical path length n=1")). In the optical path length initial value selection process, the interference light detection control unit 110 of the imaging apparatus 100 acquires an initial value of the optical path length and sets a first optical path length. Specifically, the optical path length control unit 113 of the interference light detection control unit 110 sets, for example, the optical path length corresponding to the position on the object 200 closest to the detection unit 155 as the first optical path length ("optical path length n=1").

[0038] The imaging apparatus 100 then executes optical path length command processing (step ST1030 (“command optical path length n”)). In the optical path length command processing, the optical path length control unit 113 of the interference light detection control unit 110 in the imaging apparatus 100 commands the optical path length adjustment mechanism 153b to set the nth optical path length. In the imaging apparatus 100, the optical path length b of the reference light is adjusted to the nth optical path length. The optical path length control unit 113 also outputs the nth optical path length to the image generation unit 170.

[0039] The imaging apparatus 100 then executes a pattern initial value selection process (step ST1040 ("pattern m=1")). In the pattern initial value selection process, the interference light detection control unit 110 of the imaging apparatus 100 selects an initial value for the pattern. Specifically, the DMD control unit 111 of the interference light detection control unit 110 sets the pattern identification number m to its initial value ("pattern m=1").

[0040] The imaging apparatus 100 then executes a pattern command process. In the pattern command process, the interference light detection control unit 110 of the imaging apparatus 100 performs the following process (step ST1050 (“command pattern m”)). Specifically, the DMD control unit 111 of the interference light detection control unit 110 commands the digital micromirror device 133 to execute the modulation pattern of pattern m.

[0041] The imaging apparatus 100 then executes interference light detection processing (step ST1060 ("interference light detection")). In the interference light detection processing, the interference light detection unit 150 of the imaging apparatus 100 detects interference light, which is light obtained by interference between scattered light or reflected light by the object to be measured 200 in a state in which the object to be measured 200 is irradiated with modulated light, which is light modulated by the digital micromirror device 133, and reference light, which is the modulated light when the object to be measured 200 is not irradiated. Specifically, the detection unit 155 of the interference light detection unit 150 detects interference light, which is light obtained by interference between the scattered light or reflected light and the reference light, and outputs the light intensity of the interference light to the image generation unit 170.

[0042] The imaging device 100 then executes an image calculation process (step ST1070 ("image calculation")). In the image calculation process, the image generation unit 170 of the imaging device 100 calculates an image from the correlation between the modulation pattern and the light intensity of the interference light. Specifically, the image calculation unit 171 of the image generation unit 170 calculates an image of the object to be measured 200 based on the interference light detected using the modulated light modulated by each of the multiple modulation patterns for each optical path length, based on pattern information indicating each of the multiple modulation patterns. The image calculation unit 171 stores the calculated image together with the position corresponding to the optical path length in the image temporary storage unit 173.

[0043] The imaging apparatus 100 then executes a pattern selection process. In the pattern selection process, the interference light detection control unit 110 of the imaging apparatus 100 selects the next pattern (step ST1080 (“pattern m=m+1”)). Specifically, the DMD control unit 111 of the interference light detection control unit 110 increments the number that identifies the pattern (“pattern m=m+1”).

[0044] The imaging apparatus 100 then executes an all-pattern selection determination process. In the all-pattern selection determination process, the interference light detection control unit 110 of the imaging apparatus 100 determines whether, for example, the mth pattern to be newly selected is stored in a storage unit (not shown) (step ST1090 (“Pattern m>Mmax?”).

[0045] If the interference light detection control unit 110 of the imaging device 100 determines that the mth pattern is stored in a memory unit not shown and that all patterns have not been selected (step ST1090 ("Pattern m > Mmax?" "NO")), the imaging device 100 acquires the mth pattern from the memory unit not shown, transitions to processing of step ST1050, and repeats the process from commanding pattern m.

[0046] If the interference light detection control unit 110 of the imaging apparatus 100 determines that all patterns have been selected (step ST1090 ("Pattern m>Mmax?" "YES")), the imaging apparatus 100 then executes an optical path length update process. In the optical path length update process, the interference light detection control unit 110 of the imaging apparatus 100 (step ST1100 ("optical path length n=n+1")). Specifically, the optical path length control unit 113 of the interference light detection control unit 110 increments the optical path length number n.

[0047] The imaging apparatus 100 then executes a total optical path length detection and determination process. In the total optical path length detection and determination process, the interference light detection control unit 110 of the imaging apparatus 100 performs step ST1110 ("Optical path length n>Nmax?"). Specifically, the optical path length control unit 113 of the interference light detection control unit 110 determines whether detection has been performed for all optical path lengths stored in a storage unit (not shown).

[0048] If the interference light detection control unit 110 of the imaging device 100 determines that detection has not been performed for all optical path lengths (step ST1110 ("Optical path length n>Nmax?" "NO")), it transitions to the processing of step ST1030 and repeats the processing from commanding the optical path length n. In this way, the interference light detection control unit 110 of the imaging device 100 commands the optical path length adjustment mechanism 153b to sequentially change the optical path length of the reference light that interferes with the scattered light or the reflected light, and commands the digital micromirror device 133 sequentially to use a plurality of pre-stored modulation patterns for each changed optical path length.

[0049] When the interference light detection control unit 110 of the imaging device 100 determines that detection has been performed for all optical path lengths (step ST1110 ("Optical path length n>Nmax?" "YES")), the imaging device 100 then executes image restoration processing (step ST1120 ("Image restoration")). In the image restoration processing, the image restoration unit 175 of the image generation unit 170 in the imaging device 100 reconstructs and restores a three-dimensional image of the object to be measured 200 using all images of the object to be measured 200 stored in the image temporary storage unit 173 during measurement of the object to be measured 200.

[0050] In this way, the image generation unit 170 of the imaging device 100 generates a three-dimensional image of the measured object 200 based on pattern information indicating each of the multiple modulation patterns and the interference light detected using modulated light modulated with each of the multiple modulation patterns for each optical path length.

[0051] Once imaging device 100 has performed the image restoration process, it then ends the process shown in FIG. 4 ("End").

[0052] The "object imaging device" of Patent Document 1 described at the beginning not only has a large number of devices and components, but also tends to be large in size and expensive. Furthermore, the "object imaging device" of Patent Document 1 uses an SLM, which is more expensive than a DMD, resulting in higher costs. In contrast, the imaging device 100 of the present disclosure can reduce costs compared to conventional devices.

[0053] This embodiment describes an embodiment including the following configuration: [1] An imaging apparatus including: a light source unit; a digital micromirror device that modulates light output by the light source unit; an interference light detection unit that detects interference light, which is light generated by interference between scattered light or reflected light by a measurement object in a state in which the measurement object is irradiated with modulated light, which is light modulated by the digital micromirror device, and reference light, which is the modulated light when the measurement object is not irradiated; an interference light detection control unit that commands the digital micromirror device to change the optical path length of the reference light interfering with the scattered light or the reflected light, and commands the digital micromirror device to use multiple pre-stored modulation patterns for each changed optical path length; and an image generation unit that generates a three-dimensional image of the measurement object based on pattern information indicating each of the multiple modulation patterns and the interference light detected using modulated light modulated with each of the multiple modulation patterns for each optical path length. This makes it possible to provide an imaging apparatus that enables a device for generating a three-dimensional image of a measurement object to be made smaller than conventional devices.

[0054] This embodiment shows an embodiment including the following configuration: [6] An image generation method using an imaging device, wherein a light source control unit of the imaging device commands a light source unit to output light to a digital micromirror device, an interference light detection unit of the imaging device detects interference light, which is light generated by interference between scattered light or reflected light by a measurement object in a state in which the measurement object is irradiated with modulated light, which is light modulated by the digital micromirror device, and reference light, which is the modulated light when the measurement object is not irradiated, an interference light detection control unit of the imaging device commands an optical path length adjustment mechanism to change the optical path length of the reference light interfering with the scattered light or reflected light, and commands the digital micromirror device to use a plurality of pre-stored modulation patterns for each changed optical path length, and an image generation unit of the imaging device generates a three-dimensional image of the measurement object based on pattern information indicating each of the plurality of modulation patterns and the interference light detected for each optical path length using modulated light modulated with each of the plurality of modulation patterns. As a result, the present disclosure has the effect of providing an image generation method that enables a device for generating a three-dimensional image of a measurement object to be made smaller than conventional devices.

[0055] This embodiment shows an embodiment including the configuration expressed below: [7] A program causing a computer to operate as an imaging apparatus comprising: a light source control unit that commands a light source unit to output light to a digital micromirror device, an interference light detection unit that detects interference light that is light obtained by interference between scattered light or reflected light by a measurement object in a state in which the measurement object is irradiated with modulated light that is light modulated by the digital micromirror device, and reference light that is the modulated light when the measurement object is not irradiated with the measurement object, an interference light detection control unit that commands an optical path length adjustment mechanism to change the optical path length of the reference light interfering with the scattered light or the reflected light, and commands the digital micromirror device to use a plurality of pre-stored modulation patterns for each changed optical path length, and an image generation unit that generates a three-dimensional image of the measurement object based on pattern information indicating each of the plurality of modulation patterns and the interference light detected for each optical path length using modulated light modulated with each of the plurality of modulation patterns. As a result, the present disclosure has the effect of providing a program that enables a device for generating a three-dimensional image of a measurement object to be made smaller than conventional devices.

[0056] This embodiment further illustrates an example embodiment including the following configuration: [3] An imaging device, characterized in that the pattern information includes a value indicating whether each micromirror constituting the digital micromirror device is on or off. This provides an imaging device that can be easily controlled and can easily use information used for control in processing to generate a three-dimensional image, thereby enabling a device for generating a three-dimensional image of a measurement object to be made smaller than conventional devices. Furthermore, the present disclosure provides the same effect as the above by applying the above configuration to a system including the imaging device, the image generation method, or the program.

[0057] This embodiment further shows an example embodiment including the following configuration: [4] An imaging device characterized in that the interference light detection unit includes: a reference mirror unit having a reference mirror that reflects the modulated light when it is not irradiated onto the object to be measured and an optical path length adjustment mechanism that changes the optical path length of the reference light in response to a command from the interference light detection control unit; a beam splitter that receives modulated light modulated by the digital micromirror device and splits the modulated light into light directed toward the object to be measured and light directed toward the reference mirror unit, and combines the scattered light or the reflected light with the reference light; and a detection unit that detects, by a single-pixel detector, the interference light that is light generated by the combination and interference of the scattered light or the reflected light with the reference light. Thus, the present disclosure further achieves the effect of providing an imaging device that, with a suitable configuration, enables a device for generating a three-dimensional image of a measurement object to be made smaller than conventional devices. Furthermore, the present disclosure achieves the same effects as those described above by applying the above configuration to a system including an imaging device, the above image generating method, or the above program.

[0058] This embodiment further illustrates an example embodiment including the following configuration: [5] An imaging device, wherein the interference light detection unit detects the interference light using a single-pixel detector. This provides an advantage that the present disclosure can provide an imaging device with a simple configuration that enables a device for generating a three-dimensional image of a measurement object to be made smaller than conventional devices. Furthermore, the present disclosure provides the same advantage as the above by applying the above configuration to a system including the imaging device, the image generation method, or the program.

[0059] Embodiment 2 In embodiment 2, a configuration example will be described in which the precision of image generation is improved by changing the light intensity in addition to the modulation pattern in embodiment 1. In embodiment 2, among the components according to embodiment 2, components similar to the components according to embodiment 1 already described will be given the same names and the same reference numerals, and duplicated explanations will be omitted as appropriate.

[0060] Next, a configuration example of an imaging device according to a second embodiment of the present disclosure will be described. FIG. 5 is a diagram illustrating a configuration example of an imaging device according to the second embodiment of the present disclosure. The imaging device 100 (100B) illustrated in FIG. 5 includes an interference light detection control unit 110 (110B), an optical transmission unit 130 (130B), an interference light detection unit 150, and an image generation unit 170. The imaging device 100 (100B) illustrated in FIG. 5 differs from the imaging device 100 already described mainly in the functions of the interference light detection control unit 110 (110B) and the optical transmission unit 130 (130B). Therefore, the following description will mainly focus on the different functions of the interference light detection control unit 110 (110B) and the optical transmission unit 130 (130B).

[0061] The interference light detection control unit 110 (110B) controls the detection of interference light by commanding the optical path length and modulation pattern for the interference light detected by the interference light detection unit 150 based on the modulated light transmitted by the optical transmission unit (130B). In other words, the interference light detection control unit 110 (110B) controls the measurement position measured by the interference light on the measurement object 200. The interference light detection control unit 110 (110B) also controls the intensity of light output by the light source unit 131 (131B) of the optical transmission unit (130B). The interference light detection control unit 110 (110B) commands the optical path length of the reference light that interferes with the scattered light or the reflected light to be sequentially changed, and for each changed optical path length, commands the light source unit 131 (131B) to specify the light intensity using multiple combinations of light intensity and modulation patterns stored in advance, and commands the digital micromirror device (DMD) 133 to specify the modulation pattern. The interference light detection control unit 110 (110B) shown in FIG. 5 includes a DMD control unit 111, an optical path length control unit 113, and a light source control unit 115. The light source control unit 115 controls the intensity of light output by the light source unit 131 (131B). Based on pattern information previously stored in a storage unit (not shown), the light source control unit 115 commands the light intensity to the light source unit 131 (131B) for each pattern indicated in the pattern information. The DMD control unit 111 controls a digital micromirror device (DMD) 133. The DMD control unit 111 outputs pattern information including a modulation pattern for modulating the light output from the light source unit 131 (131B). The pattern information is stored in advance in a storage unit (not shown), for example, for all pattern information used for measurement, and is used sequentially by the DMD control unit 111. The pattern information includes a value indicating the on / off state of each micromirror constituting the digital micromirror device 133. This makes it easier to program pattern information than in the past. Furthermore, the DMD control unit 111 issues commands to the digital micromirror device 133 and outputs pattern information to the image generation unit 170. The optical path length control unit 113 issues commands to the optical path length of the reference light.The optical path length control unit 113 commands the optical path length adjustment mechanism 153b of the reference mirror unit 153 to sequentially change the optical path length b within a measurable range. The interference light detection control unit 110 may be configured to control the on / off of the light output from the light source unit 131 (131B) in the optical transmitter 130. In this case, the interference light detection control unit 110 includes a light source control unit.

[0062] The image generation unit 170 generates a three-dimensional image of the object to be measured. The image generation unit 170 generates a three-dimensional image of the object to be measured 200 based on pattern information indicating each combination of light intensities and modulation patterns and the interference light detected using modulated light modulated with each of the multiple modulation patterns for each optical path length. The image generation unit 170 shown in FIG. 5 includes an image calculation unit 171, an image temporary storage unit 173, and an image restoration unit 175. The image calculation unit 171 calculates an image of the object to be measured 200 based on the interference light detected using modulated light output at each of the multiple light intensities and modulated with each of the multiple modulation patterns for each optical path length, based on pattern information indicating each combination of multiple light intensities and multiple modulation patterns. The image calculated by the image calculation unit 171 corresponds to an image of a cross section at a position on the object to be measured 200 corresponding to each optical path length. Furthermore, because the light intensity is changed, the accuracy of the generated image can be further improved compared to the first embodiment. If the amount of change a of the changing optical path length b is stored in advance, the image calculation unit 171 calculates an image for each optical path length b that changes according to the amount of change a stored in advance. If the amount of change a of the changing optical path length b is not stored in advance, the image calculation unit 171 can acquire the optical path length b or the amount of change a from the optical path length control unit 113 and use it to calculate an image for each optical path length b that changes according to the amount of change a. The image temporary storage unit 173 stores and holds the images calculated by the image calculation unit 171. The image temporary storage unit 173 stores an image corresponding to a cross section of the object 200 and an image corresponding to the rear of the object 200. The image restoration unit 175 reconstructs and restores a three-dimensional image of the object 200 using all images of the object 200 stored in the image temporary storage unit 173 during measurement of the object 200. Note that the image generation process by the image generation unit 170 can use known technology, and therefore further detailed description thereof will be omitted here.

[0063] Next, a processing example of the imaging device according to the second embodiment of the present disclosure will be described. The description will be made with reference to the flowchart shown in Fig. 4. The imaging device 100 (100B) starts the processing shown in Fig. 4 ("Start"), for example, in response to a command operation by a user, an external imaging start command, or in accordance with a pre-stored program.

[0064] The imaging device 100 (100B) then executes light source control processing (step ST1010). In the light source control processing, the light source control unit 115 of the interference light detection control unit 110 (110B) in the imaging device 100 (100B) commands the light source unit 131 (131B) of the optical transmission unit 130 (130B) to output light to the digital micromirror device 133. This causes the light source unit 131 (131B) to output light.

[0065] The imaging device 100 (100B) then executes an optical path length initial value selection process (step ST1020 (“optical path length n=1”)). In the optical path length initial value selection process, the interference light detection control unit 110 (110B) of the imaging device 100 (100B) acquires an initial value of the optical path length and sets a first optical path length. Specifically, the optical path length control unit 113 of the interference light detection control unit 110 (110B) sets, for example, the optical path length corresponding to the position of the object 200 closest to the detection unit 155 as the first optical path length (“optical path length n=1”).

[0066] The imaging device 100 (100B) then executes optical path length command processing (step ST1030 ("command optical path length n")). In the optical path length command processing, the optical path length control unit 113 of the interference light detection control unit 110 in the imaging device 100 (100B) commands the optical path length adjustment mechanism 153b to set the nth optical path length. In the imaging device 100 (100B), the optical path length b of the reference light is adjusted to the nth optical path length. In addition, the optical path length control unit 113 outputs the nth optical path length to the image generation unit 170.

[0067] The imaging apparatus 100 (100B) then executes a pattern initial value selection process (step ST1040 ("pattern m=1")). In the pattern initial value selection process, the interference light detection control unit 110 (110B) of the imaging apparatus 100 (100B) selects an initial value for the pattern. Specifically, the DMD control unit 111 of the interference light detection control unit 110 (110B) sets the pattern identification number m to its initial value ("pattern m=1").

[0068] The imaging device 100 (100B) then executes pattern command processing. In the pattern command processing, the interference light detection control unit 110 (110B) of the imaging device 100 (100B) acquires pattern information for pattern m from a storage unit (not shown) and commands pattern m indicated in the pattern information (step ST1050 ("command pattern m")). Specifically, the DMD control unit 111 of the interference light detection control unit 110 (110B) commands the digital micromirror device 133 to modulate the pattern m. In addition, the light source control unit 115 commands the light intensity of pattern m to the light source unit 131 (131B). That is, the interference light detection control unit 110 (110B) commands the light path length of the reference light that interferes with the scattered light or the reflected light to be changed in sequence, and for each changed light path length, commands the light intensity to the light source unit 131 (131B) and commands the modulation pattern to the digital micromirror device 133 using multiple combinations of light intensity and modulation patterns that have been stored in advance in sequence.

[0069] The imaging device 100 (100B) then executes interference light detection processing (step ST1060 (“interference light detection”)). In the interference light detection processing, the interference light detection unit 150 of the imaging device 100 (100B) detects interference light, which is light obtained by interference between scattered light or reflected light by the object 200 when the object 200 is irradiated with modulated light, which is light modulated by the digital micromirror device 133, and reference light, which is the modulated light when the object 200 is not irradiated with the modulated light. Specifically, the detection unit 155 of the interference light detection unit 150 detects interference light, which is light obtained by interference between the scattered light or reflected light and the reference light, and outputs the light intensity of the interference light to the image generation unit 170.

[0070] The imaging device 100 (100B) then executes an image calculation process (step ST1070 (“image calculation”)). In the image calculation process, the image generation unit 170 of the imaging device 100 (100B) calculates an image based on the correlation between the light intensity and modulation pattern and the light intensity of the interference light. Specifically, the image calculation unit 171 of the image generation unit 170 calculates an image of the object 200 to be measured based on the interference light detected using light output at multiple light intensities and modulated by each of the multiple modulation patterns for each optical path length, based on pattern information indicating each combination of multiple light intensities and multiple modulation patterns. The image calculation unit 171 stores the calculated image and a position corresponding to the optical path length in the image temporary storage unit 173.

[0071] The imaging device 100 (100B) then executes a pattern selection process. In the pattern selection process, the interference light detection control unit 110 (110B) of the imaging device 100 (100B) selects the next pattern (step ST1080 (“pattern m=m+1”)). Specifically, the DMD control unit 111 of the interference light detection control unit 110 increments the number identifying the pattern (“pattern m=m+1”).

[0072] The imaging device 100 (100B) then executes an all-pattern selection determination process. In the all-pattern selection determination process, the interference light detection control unit 110 (110B) of the imaging device 100 (100B) determines whether the mth pattern to be newly selected is stored in a storage unit (not shown) (step ST1090 (“Pattern m>Mmax?”)).

[0073] If the interference light detection control unit 110 (110B) of the imaging device 100 (100B) determines that the mth pattern is stored in a memory unit not shown and that all patterns have not been selected (step ST1090 ("Pattern m > Mmax?" "NO")), the imaging device 100 (100B) acquires the mth pattern from the memory unit not shown, transitions to processing of step ST1050, and repeats the process from commanding pattern m.

[0074] If the interference light detection control unit 110 (110B) of the imaging device 100 (100B) determines that all patterns have been selected (step ST1090 ("Pattern m>Mmax?" "YES")), the imaging device 100 (100B) then executes an optical path length update process. In the optical path length update process, the interference light detection control unit 110 (110B) of the imaging device 100 (100B) performs the following (step ST1100 ("optical path length n=n+1")). Specifically, the optical path length control unit 113 of the interference light detection control unit 110 (110B) increments the optical path length number n.

[0075] The imaging device 100 (100B) then executes a total optical path length detection and determination process. In the total optical path length detection and determination process, the interference light detection control unit 110 (110B) of the imaging device 100 (100B) performs step ST1110 ("Optical path length n>Nmax?"). Specifically, the optical path length control unit 113 of the interference light detection control unit 110 (110B) determines whether detection has been performed for all optical path lengths stored in a storage unit (not shown).

[0076] If the interference light detection control unit 110 (110B) of the imaging device 100 (100B) determines that detection has not been performed for all optical path lengths (step ST1110 ("Optical path length n > Nmax?" "NO")), it transitions to the processing of step ST1030 and repeats the processing from commanding the optical path length n. In this way, the interference light detection control unit 110 (110B) of the imaging device 100 (100B) commands the optical path length adjustment mechanism 153b to (sequentially) change the optical path length of the reference light that interferes with the scattered light or the reflected light, and commands the digital micromirror device 133 (sequentially) to execute a plurality of pre-stored modulation patterns for each changed optical path length.

[0077] When the interference light detection control unit 110 (110B) of the imaging device 100 (100B) determines that detection has been performed for all optical path lengths (step ST1110 ("Optical path length n>Nmax?" "YES")), the imaging device 100 (100B) then executes image restoration processing (step ST1120 ("Image restoration")). In the image restoration processing, the image restoration unit 175 of the image generation unit 170 in the imaging device 100 (100B) reconstructs and restores a three-dimensional image of the object to be measured 200 using all images of the object to be measured 200 stored in the image temporary storage unit 173 during measurement of the object to be measured 200.

[0078] In this way, the image generation unit 170 of the imaging device 100 (100B) generates a three-dimensional image of the measured object 200 based on pattern information indicating each of the multiple modulation patterns and the interference light detected using modulated light modulated with each of the multiple modulation patterns for each optical path length.

[0079] After performing the image restoration process, the imaging device 100 (100B) then ends the process shown in FIG. 4 ("End").

[0080] This embodiment further shows an example of an embodiment including the following configuration: [2] An imaging apparatus comprising: a light source unit, a digital micromirror device that modulates light output by the light source unit, an interference light detection unit that detects interference light that is light generated when scattered light or reflected light by a measurement object in a state in which the measurement object is irradiated with modulated light that is light modulated by the digital micromirror device, and reference light that is the modulated light when the measurement object is not irradiated, an interference light detection control unit that commands the light source unit to change the optical path length of the reference light interfering with the scattered light or the reflected light, and that commands the light intensity to the light source unit and the modulation pattern to the digital micromirror device using a plurality of combinations of light intensities and modulation patterns that are stored in advance, for each changed optical path length, and an image generation unit that generates a three-dimensional image of the measurement object based on pattern information that indicates each combination of light intensities and modulation patterns, and the interference light detected for each optical path length using modulated light modulated with each of the plurality of modulation patterns. As a result, the present disclosure further provides an imaging device that enables a device for generating a three-dimensional image of a measurement object to be made smaller than conventional devices while improving the accuracy of the generated image. Furthermore, the present disclosure provides the same effect as the above by applying the above configuration to a system including the imaging device, the above image generation method, or the above program.

[0081] Here, a hardware configuration for realizing the functions of the present disclosure will be described. Fig. 6 is a diagram showing a first example of a hardware configuration for realizing the functions of the configuration of the present disclosure. Fig. 7 is a diagram showing a second example of a hardware configuration for realizing the functions of the configuration of the present disclosure. The imaging devices 100 and 100B of the present disclosure are each realized by the hardware shown in Fig. 6 or Fig. 7.

[0082] 6, each of the imaging devices 100 and 100B includes, for example, a processor 10001, a memory 10002, an input / output interface 10003, and a communication circuit 10004. The processor 10001 and the memory 10002 are mounted on, for example, a computer. The memory 10002 stores programs that cause the computer to function as the interference light detection control units 110 and 110B, the DMD control unit 111, the optical path length control unit 113, the light source control unit 115, part of the interference light detection unit 150, part of the reference mirror unit 153, part of the detection unit 155, the image generation unit 170, the image calculation unit 171, the image restoration unit 175, and a control unit (not shown). The processor 10001 reads and executes the programs stored in the memory 10002 to realize the functions of the interference light detection control units 110, 110B, the DMD control unit 111, the optical path length control unit 113, the light source control unit 115, part of the interference light detection unit 150, part of the reference mirror unit 153, part of the detection unit 155, the image generation unit 170, the image calculation unit 171, the image restoration unit 175, and a control unit (not shown). Furthermore, the memory 10002 or another memory (not shown) realizes the functions of the image temporary storage unit 173 and a storage unit (not shown). Furthermore, the communication circuit 10004 realizes the functions of a communication unit (not shown).

[0083] The processor 10001 is, for example, 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 RAM (Random Access Memory), ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable Read Only Memory) or flash memory, or a magnetic disk such as a hard disk or flexible disk, or an optical disk such as a CD (Compact Disc) or DVD (Digital Versatile Disc), or a magneto-optical disk. The processor 10001 and the memory 10002 or the communication circuit 10004 are connected in a state capable of transmitting data to each other. The processor 10001, memory 10002, and communication circuit 10004 are connected via an input / output interface 10003 so as to be capable of transmitting data to and from other hardware.

[0084] Alternatively, in the imaging devices 100 and 100B, the functions of the interference light detection control unit 110 and 110B, the DMD control unit 111, the optical path length control unit 113, the light source control unit 115, part of the interference light detection unit 150, part of the reference mirror unit 153, part of the detection unit 155, the image generation unit 170, the image calculation unit 171, the image restoration unit 175, and a control unit not shown may be realized by a dedicated processing circuit 20001, as shown in FIG. 7.

[0085] The processing circuit 20001 may be, 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. The memory 20002 or another memory (not shown) implements the image temporary storage unit 173 and a storage unit (not shown). The memory 20002 may be a non-volatile or volatile semiconductor memory such as RAM (Random Access Memory), ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable Read Only Memory), or flash memory, or a magnetic disk such as a hard disk or flexible disk, or an optical disk such as a CD (Compact Disc) or DVD (Digital Versatile Disc), or a magneto-optical disk. The communication circuit 20004 implements a communication unit (not shown). The processing circuit 20001 and the memory 20002 or the communication circuit 20004 are connected in a state where they can transmit data to each other. The processing circuit 20001, the memory 20002, and the communication circuit 20004 are also connected in a state where they can transmit data to other hardware via the input / output interface 20003. In the imaging devices 100 and 100B, the functions of the interference light detection control units 110 and 110B, the DMD control unit 111, the optical path length control unit 113, the light source control unit 115, part of the interference light detection unit 150, part of the reference mirror unit 153, part of the detection unit 155, the image generation unit 170, the image calculation unit 171, the image restoration unit 175, and a control unit (not shown) may be realized by separate processing circuits, or may be realized collectively by a processing circuit.

[0086] Alternatively, in the imaging device 100, 100B, the functions of the interference light detection control unit 110, 110B, the DMD control unit 111, the optical path length control unit 113, the light source control unit 115, part of the interference light detection unit 150, part of the reference mirror unit 153, part of the detection unit 155, the image generation unit 170, the image calculation unit 171, the image restoration unit 175, and some of the functions of 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.

[0087] It should be noted that, within the scope of this disclosure, the embodiments may be freely combined, any component of each embodiment may be modified, or any component of each embodiment may be omitted.

[0088] The present disclosure enables devices for generating three-dimensional images of measured objects to be made smaller than conventional devices, and is therefore suitable for use in imaging devices that generate three-dimensional images of measured objects such as living organisms or clouds.

[0089] 100, 100B Imaging device, 110, 110B Interference light detection control unit, 111 DMD control unit, 113 Optical path length control unit, 115 Light source control unit, 130, 130B Optical transmission unit, 131, 131B Light source unit, 133 Digital micromirror device (DMD), 150 Interference light detection unit, 151 Light division and light combination unit, 153 Reference mirror unit, 153a Reference mirror, 153b Optical path length adjustment mechanism, 155 Detection unit, 170 Image generation unit, 171 Image calculation unit, 173 Image temporary storage unit, 175 Image restoration unit, 200 Measurement object, 300 Ghost imaging, 310 Modulation pattern (plurality of modulation patterns), 320 Measurement object, 330 Received signal, 340 Irradiation surface information, 400 Interferometer, 410 Light source, 420 Mirror, 430 Measurement object, 440 cross-sectional information, 500 image restoration algorithm, 510 modulation pattern (plural modulation patterns), 520 measurement object (cross-sectional pattern), 530 light intensity (light intensity for each pattern), 540 image (image for each cross section), 550 pattern (modulation pattern formed by DMD chip), 560 light intensity, 570 light intensity for each pattern, 580 pattern, 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 imaging device comprising: a light source unit; a digital micromirror device that modulates light output by the light source unit; an interference light detection unit that detects interference light, which is light generated when scattered light or reflected light from a measurement object when the measurement object is irradiated with modulated light, which is light modulated by the digital micromirror device, and reference light, which is the modulated light when not irradiated on the measurement object; an interference light detection control unit that commands the digital micromirror device to change the optical path length of the reference light that interferes with the scattered light or reflected light, and commands the digital micromirror device to use multiple pre-stored modulation patterns for each changed optical path length; and an image generation unit that generates a three-dimensional image of the measurement object based on pattern information indicating each of the multiple modulation patterns and the interference light detected using modulated light modulated by each of the multiple modulation patterns for each optical path length.

2. An imaging device comprising: a light source unit; a digital micromirror device that modulates light output by the light source unit; an interference light detection unit that detects interference light, which is light generated when scattered light or reflected light by a measurement object when the measurement object is irradiated with modulated light, which is light modulated by the digital micromirror device, and reference light, which is the modulated light when not irradiated on the measurement object; an interference light detection control unit that commands the light source unit to change the optical path length of the reference light interfering with the scattered light or reflected light, and commands the light intensity to the light source unit and the modulation pattern to the digital micromirror device using a plurality of combinations of light intensity and modulation patterns that are stored in advance for each changed optical path length; and an image generation unit that generates a three-dimensional image of the measurement object based on pattern information indicating each combination of light intensity and modulation pattern, and the interference light detected using modulated light modulated with each of the plurality of modulation patterns for each optical path length.

3. An imaging device according to claim 1 or 2, characterized in that the pattern information is composed of values ​​indicating whether each micromirror constituting the digital micromirror device is on or off.

4. An imaging device according to any one of claims 1 to 3, characterized in that the interference light detection unit comprises: a reference mirror unit having a reference mirror that reflects the modulated light when it is not irradiated onto the object to be measured, and an optical path length adjustment mechanism that changes the optical path length of the reference light in response to a command from the interference light detection control unit; a beam splitter that receives modulated light, which is light modulated by the digital micromirror device, and splits it into light heading towards the object to be measured and light heading towards the reference mirror unit, and merges the scattered light or the reflected light with the reference light; and a detection unit that detects the interference light, which is light caused by the convergence and interference of the scattered light or the reflected light with the reference light, using a single pixel detector.

5. An imaging device according to any one of claims 1 to 4, characterized in that the interference light detection unit detects the interference light using a single pixel detector.

6. An image generation method using an imaging device, wherein a light source control unit of the imaging device commands the light source unit to output light to a digital micromirror device; an interference light detection unit of the imaging device detects interference light, which is light generated by interference between scattered light or reflected light by the object to be measured when modulated light, which is light modulated by the digital micromirror device, is irradiated onto the object to be measured, and reference light, which is the modulated light when not irradiated onto the object to be measured; an interference light detection control unit of the imaging device commands an optical path length adjustment mechanism to change the optical path length of the reference light interfering with the scattered light or reflected light, and commands the digital micromirror device to use multiple pre-stored modulation patterns for each changed optical path length; and an image generation unit of the imaging device generates a three-dimensional image of the object to be measured based on pattern information indicating each of the multiple modulation patterns and the interference light detected for each optical path length using modulated light modulated with each of the multiple modulation patterns.

7. A program that causes a computer to operate as an imaging device comprising: a light source control unit that commands a light source unit to output light to a digital micromirror device; an interference light detection unit that detects interference light, which is light produced by interference between scattered light or reflected light by a measurement object when the measurement object is irradiated with modulated light, which is light modulated by the digital micromirror device, and reference light, which is the modulated light when not irradiated on the measurement object; an interference light detection control unit that commands an optical path length adjustment mechanism to change the optical path length of the reference light interfering with the scattered light or reflected light, and commands the digital micromirror device to use multiple pre-stored modulation patterns for each changed optical path length; and an image generation unit that generates a three-dimensional image of the measurement object based on pattern information indicating each of the multiple modulation patterns and the interference light detected using modulated light modulated with each of the multiple modulation patterns for each optical path length.

Images