Imaging device and method for controlling imaging device

Abstract

To provide a handy type terahertz imaging device capable of simultaneously controlling an irradiation angle and adjusting a focus.SOLUTION: An imaging device includes: an imaging optical system including a light emitting element for emitting a terahertz wave, an imaging element for detecting the reflected terahertz wave and a focus lens and for imaging the terahertz wave on the imaging element; a support member for supporting the light emitting element; posture change means for changing the posture of the support member; focus change means for changing a position of the focus lens; input means for inputting information on a set distance; and execution means for changing the posture of the support member and changing the position of the focus lens on the basis of the information on the set distance.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an imaging device that utilizes terahertz waves. [Background technology]

[0002] Recently, preventing crimes involving concealed dangerous goods has become an issue at airports and other locations, creating a demand for technologies to detect such goods. One such inspection technology is an imaging device that uses terahertz waves. Terahertz waves are generally defined as electromagnetic waves with frequencies between 30 GHz and 30 THz, and their long wavelengths allow them to penetrate clothing and other materials. In addition to large, stationary gate-type imaging devices, handheld imaging devices are also desired as a non-contact alternative to conventional body checks.

[0003] Patent Document 1 discloses a configuration in which terahertz waves are irradiated from an illumination unit toward a subject and the terahertz waves reflected from the subject are acquired by an imaging unit, for the purpose of inspecting concealed items during body checks and other similar activities in public places. When attempting to configure a handheld terahertz imaging device using this prior example, the following problems arise. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-81443 Summary of the Invention [Problem to be solved by the invention]

[0005] Because terahertz waves have a wavelength relatively longer than the unevenness of the subject's surface, terahertz waves irradiated onto the subject's surface are specularly reflected rather than scattered by the surface. Therefore, the angle of the illumination must be set so that the terahertz waves specularly reflected by the subject enter the camera unit. With handheld cameras, the user can change the shooting range as needed, so the distance between the subject and the imaging device is not necessarily constant. For example, a user might photograph the subject from a distance, check the entire subject, and then move the imaging device closer to the subject to capture a close-up of a portion of the subject. Therefore, the angle of the illumination must be readjusted each time the distance between the subject and the imaging device changes.

[0006] Furthermore, if the distance between the subject and the imaging device changes, the focus must also be readjusted. Therefore, the user must both adjust the lighting angle and focus, which takes time to capture the intended image. More specifically, the user must first adjust the lighting angle so that the lighting hits the subject, but the subject will not be visible in the camera until the lighting is properly applied, making it impossible to adjust the focus in advance. In other words, even if the lighting angle is adjusted, the subject will appear out of focus and out of focus. With a blurred subject, it is difficult to determine whether the intended range has been captured, so after focusing, the user must again fine-tune the lighting angle. Therefore, it takes time to capture the intended image. [Means for solving the problem]

[0007] In order to solve the above problem, an imaging device according to one aspect of the present invention comprises a light-emitting element that irradiates a subject with terahertz waves, an imaging element that detects the terahertz waves reflected by the subject, an imaging optical system that has a focus lens and images the terahertz waves reflected by the subject on the imaging element, a support member that supports the light-emitting element, a housing that supports the support member, an attitude change means that changes the attitude of the support member relative to the housing, a focus change means that is provided in the imaging optical system and changes the position of the focus lens, an input means that inputs set distance information that is a set value of the distance from the imaging element to the subject, and an execution means that changes the attitude of the support member by the attitude change means and changes the position of the focus lens by the focus change means based on the set distance information. [Effects of the Invention]

[0008] According to the present invention, in a terahertz imaging device, adjustment of the illumination angle and focus can be performed simultaneously, thereby shortening the time required to start capturing images as intended by the user. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a diagram showing functional blocks of the imaging apparatus of the first embodiment. [Figure 2] FIG. 1 is a diagram illustrating a hardware configuration of an imaging apparatus according to a first embodiment. [Figure 3] 1 is a diagram showing the appearance of an imaging device according to a first embodiment. [Figure 4] 1 is an explanatory diagram showing the internal configuration of the imaging device of the first embodiment as viewed from above. [Figure 5] 4A and 4B are diagrams illustrating a rotating means of a second support member in the first embodiment. [Figure 6] 2 is a diagram illustrating the positional relationship between a light emitting element, an imaging element, and a subject according to the first embodiment. FIG. [Figure 7] 2 is a diagram illustrating the positional relationship between a light emitting element, an imaging element, and a subject according to the first embodiment. FIG. [Figure 8]2 is a diagram illustrating the positional relationship between a light emitting element, an imaging element, and a subject according to the first embodiment. FIG. [Figure 9] FIG. 3 is a diagram showing an operation flow of the imaging apparatus of the first embodiment. [Figure 10] FIG. 2 is a diagram illustrating an example of a display means of the imaging device of the first embodiment. [Figure 11] FIG. 10 is an explanatory diagram showing the internal configuration of the imaging device of the second embodiment as viewed from above. [Figure 12] 10A and 10B are diagrams illustrating a rotating means for a first support member and a second support member in the second embodiment. [Figure 13] FIG. 10 is a diagram showing functional blocks of a third embodiment. [Figure 14] FIG. 11 is an explanatory diagram showing the internal configuration of an imaging device according to a third embodiment as viewed from above. [Figure 15] 10A and 10B are diagrams illustrating a rotating means of a support member according to a third embodiment. [Figure 16] 10A and 10B are diagrams illustrating the positional relationship between the light emitting element and the image sensor before and after the movement of the subject in the third embodiment. [Figure 17] 10A and 10B are diagrams illustrating the positional relationship between the light emitting element and the image sensor before and after the movement of the subject in the third embodiment. [Figure 18] 10A and 10B are diagrams illustrating the positional relationship between the light emitting element and the image sensor before and after the movement of the subject in the third embodiment. [Figure 19] 10A and 10B are diagrams illustrating the positional relationship between the light emitting element and the image sensor before and after the movement of the subject in the third embodiment. [Figure 20] FIG. 10 is a diagram showing functional blocks of an imaging apparatus according to a fourth embodiment. [Figure 21] FIG. 10 is a diagram illustrating a hardware configuration of an imaging apparatus according to a fourth embodiment. [Figure 22] FIG. 10 is a diagram showing the appearance of an imaging device according to a fourth embodiment. [Figure 23] FIG. 10 is an explanatory diagram showing the internal configuration of an imaging device according to a fourth embodiment as viewed from above. [Figure 24] 10 is a diagram illustrating the positional relationship between a light emitting element, an image sensor, a subject, and a distance measuring sensor according to a fourth embodiment. FIG. [Figure 25] FIG. 10 is a diagram showing the appearance of an imaging device according to a fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] The following describes in detail embodiments of the present invention. Note that the embodiments described below are examples for realizing the present invention, and should be modified or adjusted as appropriate depending on the configuration of the device to which the present invention is applied and various conditions, and the present invention is not limited to the following embodiments. Furthermore, parts having the same functions in all figures are designated by the same numerals, and repeated explanations thereof will be omitted. <Embodiment 1> (Functional configuration)

[0011] 1 is a functional block diagram of an imaging device 100 according to embodiment 1. The imaging device 100 includes an imaging optical system 101 equipped with a focus changing unit 102, an imaging unit 103 that is sensitive to terahertz waves, and an illumination unit 105 that irradiates a subject with terahertz waves.

[0012] It also includes a first rotation means 106 which is a first attitude change means for changing the angle of the illumination unit 105 relative to the housing, a second rotation means 104 which is a second attitude change means for changing the angle of the imaging unit 103 relative to the housing, and a control unit 107 which is an execution means.

[0013] Furthermore, the imaging device 100 is equipped with an input unit 109, which is an input means by which the user can input setting distance information when changing the angle between the lighting unit 105 and the imaging unit 103 relative to the housing, and a display unit 108, which is a display means by which the user can check the captured image.

[0014] The imaging optical system 101 causes the focus changing means 102 to form an image of a subject on the imaging unit 103, and the imaging unit 103 captures the subject image, converts it into an image signal, and transfers it to the control unit 107. The control unit 107 processes the received image signal, converts it into image data, and displays it on the display unit 108 as a captured image.

[0015] Furthermore, the control unit 107 receives set distance information from the input unit 109 according to a user operation, and instructs the second rotation means 104 and the first rotation means 106 to change the angle according to the set distance information. The second rotation means 104 and the first rotation means 106 drive the imaging unit 103 and the illumination unit 105 so that they are at the instructed angle.

[0016] Furthermore, the control unit 107 changes the position of the focus lens 406 through the focus changing means 102 in accordance with the angle between the image capturing unit 103 and the illumination unit 105 .

[0017] 1, the control unit 107 and the display unit 108 are incorporated inside the imaging device 100, but they may also be provided outside the imaging device 100 and data may be transferred from the imaging device 100 via a cable or wireless communication. Furthermore, one functional block of the functional blocks shown in Fig. 1 may be made up of multiple functional blocks, or multiple functional blocks may be combined into one functional block. (Hardware configuration)

[0018] 2 is a diagram showing the hardware configuration of the imaging device 100 according to embodiment 1. A second support member 201, which is a camera module, supports a lens 202 with a focus mechanism and an imaging element 203, which is an element for capturing an image of terahertz waves.

[0019] The focus lens 406 of the lens with focus mechanism 202 is made of, for example, high-density polyethylene (HDPE) as a material. High-resistance silicon, Teflon (registered trademark) (Poly Tetra Fluoro Ethylene: PTFE), etc. may also be used as the material.

[0020] The focus lens 406 of the lens with focus mechanism 202 may be a fixed focal length lens or a zoom lens whose focal length is variable. It may also be equipped with an aperture. An actuator 204 for changing the position of the focus lens 406 is connected to the lens with focus mechanism 202.

[0021] The actuator 204 is composed of a motor, gears, a motor driver, etc., and can change the focus position by changing the position of the focus lens 406. The lens with focus mechanism 202 and the actuator 204 correspond to the imaging optical system 101 and the focus changing means 102 in the functional block diagram of FIG.

[0022] The image sensor 203 corresponds to the image sensor 103 in the functional block diagram of FIG. 1, and is configured using, for example, a Schottky barrier diode, a bolometer, an MEMS resonator, and the like.

[0023] An actuator 205 for changing the angle is connected to the second support member 201. The actuator 205 is composed of a motor, gears, a motor driver, etc. The actuator 205 corresponds to the second rotation means 104 in FIG. 1, and is composed of a motor, gears, a motor driver, etc., just like the actuator 204. More specific details will be described later with reference to FIGS. 4 and 5.

[0024] The light emitting element 207 that emits terahertz light corresponds to the illumination unit 105 in the functional block diagram of FIG. 1, and is equipped with, for example, an antenna consisting of a negative differential resistance element and a resonant circuit. The negative differential resistance element may be a resonant tunneling diode or the like. The light emitting element 207 may also be composed of multiple light emitting elements. The emission intensity can be increased by resonantly driving the multiple light emitting elements.

[0025] The light emitting element 207 is supported by a first support member 404 , and an actuator 206 for changing the angle of the light emitting element 207 is connected to the first support member 404 .

[0026] 1, and is composed of a motor, gears, motor driver, etc., similar to actuators 204 and 205. The specific configuration will be described later with reference to FIGS.

[0027] Furthermore, the first support member 404 and the second support member 201 are movably supported on the housing of the imaging device 100. The light emitting element 207 may be provided with a lens for controlling the light collection range. The lens may be made of high density polyethylene, high resistance silicon, or Teflon (registered trademark), similar to the focus lens 406 of the lens with focus mechanism 202. When a lens is provided, it is preferable to configure the actuator 206 so that the angles of both the lens and the light emitting element 207 can be changed.

[0028] The ring member 208 and sensing element 209 correspond to the input unit 109 in the functional block diagram of Fig. 1, and are operation units that allow the user to input set distance information, which is a set value for the distance from the image sensor 203 to the subject. The ring member 208 is used when the user changes the attitude, such as the angle, of the first support member 404 and the second support member 201. The user rotates the ring member 208, and a signal corresponding to the amount of rotation is output from the sensing element 209 and sent to a CPU (Central Processing Unit) 210, which will be described later.

[0029] The sensing element 209 may be, for example, a rotary encoder, a photointerrupter, or a magnetic sensor. The ring member 208 and the sensing element 209 may be configured with other elements as long as they are capable of detecting the amount of operation by the user. For example, the ring member 208 may have a structure similar to a zoom lever in a video camera or a jog dial used in AV equipment. Alternatively, the ring member 208 may have a structure similar to a cross key or a stick lever. When a zoom lever-type structure is used, the sensing element 209 may be configured with a magnetic sensor, a photointerrupter, or multiple electrical contacts. In this embodiment, a case where a ring member and a rotary encoder are used will be described as an example.

[0030] The CPU 210 is configured with a dedicated circuit such as an ASIC (Application Specific Integrated Circuit) or a processor such as an FPGA (Field Programmable Gate Array). The memory 211 is configured with a volatile memory such as a RAM (Random Access Memory) and a non-volatile memory such as a ROM (Read Only Memory). Some of the functional blocks of the imaging device 100 shown in Fig. 1 are realized by having the CPU 210, which is an execution means (execution unit), execute a computer program stored in the memory 211.

[0031] 1 and is configured with a liquid crystal display, an organic EL display, a cathode ray tube, etc. The display 212 may be provided outside the imaging device 100, and display data may be transferred from the imaging device 100 via wired or wireless communication.

[0032] 3 shows an example of the appearance of the imaging device 100. The imaging device 100 is composed of a camera head 301, which is a housing, and a handle 304. A first support member 404 and a second support member 201 are arranged inside the camera head 301 (not shown). The internal structure of the camera head will be explained in detail with reference to FIG. 4.

[0033] The camera head 301 is provided with an opening window 302 for the light emitting element 207 and an opening window 303 for the image pickup element 203. The opening windows 302 and 303 may be made of, for example, high density polyethylene, high resistance silicon, or Teflon (registered trademark), or may simply be cut-out holes.

[0034] The handle 304 is provided with a ring member 208 that is operated by the user. When the user rotates the ring member 208, which is the input unit 109, information corresponding to set distance information, which is a set value of the distance from the image sensor 203 to the subject, is input. A rotary encoder (not shown) that senses the amount of rotation is provided inside the ring member 208. The angle between the first support member 404 and the second support member 201 inside the camera head 301 is configured to change depending on the amount of rotation of the ring member 208.

[0035] Fig. 4 is a perspective view looking down from above at the camera head 301 in Fig. 3. Inside the camera head 301, the light emitting element 207, the image sensor 203, and the focus lens 406 are arranged as shown in the figure. The light emitting element 207 is supported by a first support member 404.

[0036] A motor 401 is disposed in the housing, and the first rotation unit 106 rotates the first support member 404 relative to the housing by rotation of the motor 401. The angle of the light emitting element 207 supported by the first support member 404 relative to the housing is changed. In FIG. 4, a line connecting the center P01 of the light emitting element 207 and the center P02 of the image sensor 203 is denoted as LN1. The rotation axis 411 of the first support member 404 passes through the midpoint P03 of the line LN1, is perpendicular to a plane including a line LN2 extending toward the subject, and passes through the center P01 of the light emitting element 207. Here, the center of the light emitting element 207 refers to the center of an area in which multiple light emitting elements are arranged when the light emitting element 207 has multiple light emitting elements. Details of the first rotation unit 106 will be described later with reference to FIG. 5.

[0037] 4, an image sensor 203 and a lens with a focus mechanism 202 are supported by a second support member 201. A motor 402 is disposed in the housing, and second rotation means 104 rotates the second support member 201 relative to the housing by rotation of the motor, and the angle of the image sensor 203 relative to the housing is changed.

[0038] 4, the rotation axis 412 of the second support member 201 passes through the center P02 of the image sensor 203 and is parallel to the rotation axis 411. The center of the image sensor 203 means the center of the area in which the multiple light receiving elements of the image sensor 203 are arranged. Details of the second rotation means 104 will be described later with reference to FIG. The shooting direction is changed by rotating the second support member 201 by the second rotation means 104.

[0039] 4, the lens with focus mechanism 202 is provided with a focus lens 406 and a motor 403 for driving the focus lens 406. The focus position is changed by the motor 403 moving the focus lens 406 in the direction of the optical axis of the lens.

[0040] Figure 5 is a diagram for explaining the rotation means in Figure 4. Figure 5(A) is a diagram showing the second support member 405 in Figure 4 as seen from the side, and shows the structure when viewed from the front of the second support member 201 toward the imaging element 203. Figure 5(B) is a diagram showing the second support member 201 as seen from below.

[0041] 5(A), as explained in FIG. 4, the lens 202 with a focus mechanism and the image sensor 203 are supported by the second support member 201. A member 405 provided integrally with the second support member 201 is provided with a helical gear 501, and a worm 502 connected to the shaft of the motor 401 is engaged with the helical gear 501.

[0042] 5(B), the second rotating means 104 has a motor 402 as a driving source, and a worm 502 and a helical gear 501 as a transmission mechanism that transmits the rotation of the motor 402 to the second support member 201. Similarly, the first rotating means 106 of the first support member 404 has a motor 401 as a driving source, and a worm and a helical gear as a transmission mechanism that transmits the rotation of the motor 401 to the first support member 404.

[0043] 6 is a diagram illustrating the positional relationship between the light-emitting element 207, image sensor 203, and subject when capturing an image using terahertz light. The light-emitting element 207 and image sensor 203 are arranged at an angle facing the subject 601, that is, in a V-shape when viewed from the subject 601. In the figure, θ indicates the angle formed by the light-emitting element 207 and the image sensor 203, with a straight line LN1 connecting the center P01 of the light-emitting element 207 and the center P02 of the image sensor 203. Hereinafter, θ will be referred to as the flapping angle.

[0044] In the drawing, D represents the distance from the midpoint P03 of the line LN1 connecting the center P01 of the light-emitting element 207 and the center P02 of the image sensor 203 to the subject 601. In the drawing, L represents the length of the line connecting the center P01 of the light-emitting element 207 and the center P02 of the image sensor 203. In the drawing, A represents the distance between the center P02 of the image sensor 203 and the subject 601.

[0045] As described above, the wavelength of terahertz waves is relatively longer than the unevenness of the surface of the subject, so the terahertz waves irradiated onto the surface of the subject are not scattered by the surface but are specularly reflected. In other words, the image sensor 203 can acquire only the component of the terahertz waves irradiated from the light-emitting element 207 that is specularly reflected by the surface of the subject 601.

[0046] 6, most of the terahertz waves specularly reflected by the subject 601 can be incident on the image sensor 203. If the subject 601 moves closer to or farther away from the image sensor 100 and moves away from the position shown in FIG. 6, the terahertz waves emitted from the light emitting element 207 will no longer hit the subject 601. Furthermore, even if the terahertz waves hit the subject 601, only a portion of the specularly reflected terahertz light will enter the image sensor 203. In other words, the subject may not be captured at all or only a portion of it may be captured within the capture range. Fig. 7 shows the case where the subject is farther away than in Fig. 6 (D'>D). Only a portion of the terahertz waves emitted from the light emitting element 207 hits the subject and is specularly reflected, and only a portion of the reflected light enters the image sensor 203, so only a portion of the subject 601 can be captured.

[0047] In FIG. 8, the tilt angles of the light-emitting element 207 and the image sensor 203 are changed (θ'<θ) so that the subject 601 at the position shown in FIG. 7 can be photographed. Changing the tilt angle in this way makes it possible to photograph the subject 601 that has moved away. While an illustration of the case where the subject 601 approaches is omitted, it is possible to photograph the subject 601 by increasing the tilt angle. However, even without changing the tilt angle θ', the image sensor 203 can still photograph the subject 601 because terahertz waves specularly reflected by the subject 601 are incident thereon. In other words, by changing the tilt angle of the light-emitting element 207 but not the image sensor 203, it is possible to simultaneously adjust the illumination angle and focus, thereby shortening the time required to start photographing as intended by the user. Therefore, the configuration of the first embodiment includes the following configuration in which the tilt angle of the light-emitting element 207 is changed but the tilt angle of the image sensor 203 is not changed. The imaging device includes a light-emitting element, an image sensor, a focus lens, an imaging optical system, a support member, and a housing. Then, based on the set distance information input to the input means, the execution means of the imaging device changes the attitude of the support member by the attitude changing means and changes the position of the focus lens by the focus changing means.

[0048] On the other hand, since the terahertz waves are incident on the imaging element 203 at an angle, shading may occur. For this reason, it is desirable to change the tilt angle of the imaging element 203 to θ'. In other words, it is desirable to make the angle by which the first support member 404 is rotated by the first rotating means 106 the same as the angle by which the second support member 201 is rotated by the second rotating means 104. Furthermore, as is clear from FIGS. 6 and 8, the direction in which the first support member 404 is rotated by the first rotating means 106 is opposite to the direction in which the second support member 201 is rotated by the second rotating means 104.

[0049] Next, the focus position will be described with reference to FIGS. 6 and 8. θ and L in FIG. 6 are known values ​​because they are design values ​​of the image pickup device 100. The distance A between the object 601 and the image pickup element 203 is A = L / (2 sinθ) (1) Even when the subject position changes as shown in FIG. 8, the new elevation angle θ' can be used to calculate the elevation angle θ using equation (1). In other words, the position of the focus lens 406 required for focusing can be uniquely determined from the value calculated using equation (1). How the elevation angle θ itself is set will be described with reference to FIG. 9.

[0050] 9 is a flowchart showing the internal processing of the imaging device 100 when a user takes a picture using the imaging device 100. The explanation will be made assuming that the subject 601 is at a distance that cannot be photographed with the initial value of the flapping angle. (S1) CPU 210 performs automatic calibration on imaging device 100 when it is started up, and transmits the elevation angle θ at the start of imaging and the distance A to the subject to memory 211. The flag is positioned in advance so that the elevation angle θ when a sensor provided on the housing detects the flag attached to second support member 405 is a predetermined angle. (S2) While checking the photographed image displayed on the display 212, the user rotates the ring member 208 of the handle 304 so that the subject 601 appears on the display 212. (S3) At this time, the amount of rotation of the ring member 208 from the start is converted into a signal by the rotary encoder, which is the sensing element 209, and is sent to the CPU 210, which is the execution means. (S4) The CPU 210 calculates the amount of change in the tilt angle θ of the light emitting element 207 and the image sensor 203 according to the amount of rotation, and issues a drive command to the motors 401 and 402. At the same time, the CPU 210 calculates the distance A' corresponding to the new tilt angle θ' using equation (1), and issues a drive command to the motor 403 to move the focus lens 406 to a position where the focus is set to the distance A'.

[0051] Any value can be set for the amount of change in the flap angle relative to the amount of rotation of the ring member 208. If the set value is large, the user can quickly change the flap angle, but fine adjustments become difficult. Conversely, if the set value is small, fine adjustments to the flap angle become easier, but large changes in the flap angle take time. (S5) The CPU 210 rotates the motors 401 and 402 to rotate the first support member 404 and the second support member 201, setting the tilt angle to θ'. At the same time, the motor 403 is rotated to move the focus lens 406 to a position where it focuses on the image sensor 203 at a distance A'. (S6) If the subject 601 is not displayed on the display 212, the process returns to S1, and the user again turns the ring member 208. If an appropriate flapping angle according to the distance to the subject 601 has been set, the subject 601 will appear on the display 212 in this step. As the subject 601 gradually appears on the display 212 during the transition from (S5) to (S6), the focus will gradually approach in-focus, allowing the user to view a captured image that is nearly in focus, and allowing fine adjustment of the shooting range at this point. (S7) At the same time that the subject 601 is captured on the display 212, the subject 601 is also brought into focus, making it possible to take a photograph as intended by the user.

[0052] 9, the user searches for an appropriate flap angle by trial and error, but to enable the user to set an appropriate flap angle more quickly, the photographable distance at the current flap angle may be displayed on the display 212. Also, an icon or message may be displayed so that the user can see the direction in which the ring member 208 is rotated and the direction in which the photographing distance changes.

[0053] An example of the display is shown in Fig. 10. Fig. 10 is a view of the imaging device 100 of Fig. 3 seen from behind. The display 212 is disposed on the back of the camera head 301. The display "current shooting distance" may be a distance D that can be calculated from the current elevation angle θ using the following equation (2): D=L / (2tanθ) (2) The rotation direction of the ring member 208 and the direction of change in the perspective of the shooting distance may be displayed on the display 212 as shown in Figure 10, or they may not be displayed on the display 212 but may be printed or engraved on the housing of the camera head 301, for example. <Embodiment 2>

[0054] In the second embodiment, a case will be described in which one motor is removed from the second embodiment. Fig. 11 is a perspective view of the camera head 301 as viewed from above. The motor 402 in Fig. 4 has been removed, and the motor 401 now drives both the first support member 404 and the second support member 405. The rest is the same as in Fig. 4, so a description thereof will be omitted.

[0055] 12(A) when viewed from the side, the motor 401, first support member 404, and second support member 201 have the configuration shown in Fig. 12(A). Worm 503 connected to the shaft of motor 401 meshes with both helical gear 501 and helical gear 504. The angles of helical gear 501 and helical gear 504 are opposite so that they rotate in opposite directions.

[0056] 12(B) shows the structure of Fig. 12(A) viewed from below. When worm 503 rotates, helical gear 501 and helical gear 504 rotate in opposite directions. First rotating means 106, which rotates first support member 404, has motor 401, which is a rotatable drive source, and helical gear 504, which is a first transmission mechanism, which transmits the rotation of motor 401 to first support member 404.

[0057] In addition, the second rotating means 104 that rotates the second support member 201 has a helical gear 501 that is a transmission mechanism that transmits the rotation of the motor 401 to the second support member 201. With this configuration, one motor can be eliminated compared to the first embodiment, thereby enabling miniaturization and cost reduction. <Embodiment 3>

[0058] 13 is a functional block diagram of embodiment 3. In embodiment 3, the light emitting element 207 and the image sensor 203 are not rotated by a rotating means, but are moved by a first moving means 716 and a second moving means 714.

[0059] 14 shows a perspective view of the camera head 301 of embodiment 3. The first support member 701 supports the light emitting element 207, and the second support member 201 supports the image sensor 203 and the focus lens 406.

[0060] In the third embodiment, the first attitude changing means is a first moving means 716, which moves the first support member 701 by a motor 401, a pinion 703, and a rack. The second attitude changing means is a second moving means 714, which moves the second support member 702 by a motor 402, a pinion, and a rack.

[0061] The first support member 701 and the second support member 201 are moved in the movement directions indicated by the two-way arrows by first moving means 716 and second moving means 714, respectively. Details of the mechanism and operation of the moving means will be explained below with reference to Figure 15. The rest of the configuration is the same as in embodiment 1, so explanations will be omitted.

[0062] FIG. 15 is a view of the second support member 201 as seen from the front. The underside of the second support member 201 is toothed to form a rack. A pinion 703 meshes with the rack of the second support member 201, and the pinion 703 is attached to a motor shaft 704 of a motor 402 (not shown) located at the back of the figure. When the motor 402 rotates the pinion 703, the second support member 201 moves left and right in the figure according to the direction of rotation. The first support member 701 has a similar configuration, so its description is omitted. Changing the distance from the image sensor 203 to the subject using this movement means will be described with reference to FIG. 16.

[0063] 16(A) and (B) are diagrams for explaining the movement of the positions of the first support member 701 and the second support member 201 when the distance between the subject 601 and the imaging device 100 changes. Fig. 16(A) shows a state in which it is possible to photograph the subject 601 at a certain distance. Fig. 16(B) shows the changed positions of the first support member 701 and the second support member 201 when the subject 601 moves closer to the imaging device 100 from the position in Fig. 16(A).

[0064] 17 is a diagram illustrating the change in the positional relationship between the light emitting element 207 and the image sensor 203 before and after movement by the first moving means 716 and the second moving means 714. The movement direction of the light emitting element 207 and the movement direction of the image sensor 203 will be described with reference to FIG.

[0065] 17, the line connecting the center P01 of the light-emitting element 207 and the center P02 of the image sensor 203 is designated as LN1, the midpoint of the line LN1 is designated as P03, and the line passing through the midpoint P03 and extending in the direction of the subject 601 is designated as a first line LN2. In this embodiment, the direction of movement of the center of the light-emitting element 207 is a direction VT1 that is parallel to a plane including the line LN1 and the first line LN2 and intersects with the first line LN2.

[0066] The direction of movement of the center of the image sensor 203 is a direction VT2 that is parallel to a plane including the straight line LN1 and the first straight line LN2 and intersects with the first straight line LN2. The lengths of VT1 and VT2 respectively indicate the movement distance of the center of the light-emitting element 207 and the movement distance of the center of the image sensor 203. That is, VT1 and VT2 respectively indicate the movement direction and movement distance of the center of the light-emitting element 207 and the movement direction and movement distance of the center of the image sensor 203.

[0067] As shown in Figure 17, the direction and distance of movement of the center of the light-emitting element 207 by the first moving means 716 are in a line-symmetric relationship with the direction and distance of movement of the center of the image sensor 203 by the second moving means 714 about the first straight line LN2.

[0068] With this configuration, when the first support member 701 and the second support member 201 are moved in a direction in which they approach each other, the terahertz waves hit the approaching subject 601, and the reflected terahertz waves can be made incident on the image sensor 203.

[0069] Furthermore, the movement distance of the focus lens 406 can be calculated as follows. The distance L between the center of the light-emitting element 207 and the center of the image sensor 203, and the direction and movement distance of the first movement unit 716 and the second movement unit 714 are known. Therefore, the position (movement distance) to which the focus lens 406 should be moved can be uniquely calculated using the above-mentioned formula (1). In this way, as in the first embodiment, after the user inputs the set distance information, it is possible to move the light-emitting element 207 and the image sensor 203 and focus the subject image on the image sensor without any time delay.

[0070] Furthermore, in the third embodiment, even if the subject moves laterally relative to the imaging device 100, it is possible to capture the subject.

[0071] Consider a case where subject 601 has been captured as shown in FIG. 18(A), but then moves to the left as shown in FIG. 18(B). As mentioned above, when capturing images with terahertz waves, the specular reflection component is captured. Therefore, if subject 601 moves forward, backward, left, or right from the position of subject 601 in FIG. 18(A), the specular reflection relationship is disrupted, and subject 601 moves out of the capture range. In such a case, as shown in FIG. 18(B), light-emitting element 207 is moved downward and left in the figure, and image sensor 203 is moved upward and left by the same amount. This movement allows the terahertz waves irradiated by light-emitting element 207 to strike subject 601, which has moved laterally, and the specular reflection component can be captured by image sensor 203.

[0072] FIG. 19 is a diagram illustrating the relationship between the amount of movement of the light-emitting element 207 and image sensor 203 and the distance A from the image sensor 203 to the object 601 when the object moves laterally. FIG. 19 shows the position of the object 601 after it has moved leftward in the figure, and the dotted frame indicates the position before the object 601 moved. The amount of movement of the object 601 at this time is designated as W. The light-emitting element 207 has moved downward and leftward in the figure, and the image sensor 203 has moved upward and leftward in the figure, the same amount from their original positions indicated by the dotted frame. This amount of movement is designated as P. Because the flapping angle remains unchanged from θ before and after the movement, if the amount of movement of the light-emitting element 207 is designated as S, S can be calculated using the following equation (3): S=Pcosθ (3)

[0073] This also applies to the image sensor 203. On the other hand, the horizontal movement amounts W and P of the subject 601 satisfy the following equation (4). W=P / cosθ (4)

[0074] If the difference between the movement amount S of the light emitting element 207 and the image sensor 203 and the movement amount W of the subject 601 is set as B, the following calculation can be made from equations (3) and (4): B=W―S=P / cosθ―Pcosθ (5)

[0075] If the distance between the centers of the light-emitting element 207 and the image sensor 203 is L, then since both have moved to the left by S, the value of L remains unchanged after the movement. L is a known value because it is a design value of the image sensing device 100. If a perpendicular line is drawn from the center of the object 601 after movement in the vertical direction in the figure, and the distance from this intersection with the line connecting the centers of the light-emitting element 207 and the image sensor 203 to the image sensor 203 is Z, then Z can be calculated using the following equation (6): Z=L / 2+B (6)

[0076] Therefore, the distance A from the image sensor 203 to the subject 601 can be calculated by the following equation (7). A=Z / sinθ =(L / 2+B) / sinθ =(L / 2+P / cosθ−Pcosθ) / sinθ (7)

[0077] If, simultaneously with the movement of the light emitting element 207 and the image sensor 203, the focus lens 406 is moved to a position where the subject image is focused on the image sensor 203 at the distance A calculated by equation (7), it is possible to perform imaging similar to that of embodiment 1. In this way, in embodiment 3, by moving the light emitting element 207 and the image sensor 203, it is possible to accommodate not only the movement of the subject 601 in the forward / backward direction but also the movement in the left / right direction.

[0078] As described in the first embodiment, in the third embodiment, the terahertz waves specularly reflected by the subject 601 are incident, and therefore, it is possible to capture an image. That is, with a configuration in which the light-emitting element 207 is moved but the image sensor 203 is not moved, it is possible to simultaneously adjust the illumination position and adjust the focus, thereby shortening the time required to start capturing an image as intended by the user. Therefore, the configuration of the third embodiment includes a configuration in which the light-emitting element 207 is moved but the image sensor 203 is not moved.

[0079] 3 on the handle 304, one for operations corresponding to changes in the forward / backward direction of the subject, and the other for operations corresponding to changes in the left / right direction of the subject, which simplifies operation. Alternatively, a cross key or joystick may be provided in place of the ring member, and the configuration may be such that up / down inputs correspond to forward / backward movement of the subject, and left / right inputs correspond to left / right movement of the subject. <Embodiment 4>

[0080] The fourth embodiment has a configuration in which a distance measuring unit is added to the imaging device 100 of the first embodiment. FIG. 20 shows a functional block diagram. The imaging device 100 is equipped with a distance measuring unit 801, which is a distance measuring unit capable of measuring the distance to a subject. Set distance information input to the input unit 109 is sent to the control unit 107 and stored as a target value in the memory 211 of FIG. 21. The measurement result by the distance measuring unit 801 is sent to the control unit 107. The control unit 107 calculates an appropriate tilt angle θ and focus position based on the difference between the measurement result and the target value, and issues drive instructions to the first rotation unit 106, the second rotation unit 104, and the focus change unit 102. As a result, the imaging unit 103 and the illumination unit 105 are set to a tilt angle θ corresponding to the set distance information with respect to the subject. At the same time, it becomes possible to adjust the focus to the subject located at the position indicated by the set distance information. Since the rest of the configuration is the same as that of the first embodiment, a description thereof will be omitted.

[0081] Fig. 21 shows an example of the hardware configuration of the fourth embodiment. The imaging device 100 is provided with a TOF (Time of Flight) sensor 802, which corresponds to the distance measurement unit 801 in Fig. 20. The TOF sensor 802 may be replaced with a distance measurement sensor that uses radar or ultrasonic waves. The rest is the same as in the first embodiment, so a description thereof will be omitted.

[0082] 22 shows the external appearance of the imaging device 100 of this embodiment. An aperture 803 for the distance measurement sensor is provided between apertures 302 and 303. The aperture may be made of a material through which the light source of the TOF sensor can pass, and in the case of infrared light, it may be made of glass or resin. Alternatively, it may simply be a cut-out hole. Furthermore, although the TOF sensor is configured to be provided inside the camera head 301, the TOF sensor 802 may also be provided, for example, on top of the camera head.

[0083] 23 is a perspective view looking down on the imaging device 100. A TOF sensor 802 is provided at the midpoint between the light emitting element 207 and the imaging element 203.

[0084] 24 is a diagram illustrating the positional relationship between the light-emitting element 207, the image sensor 203, the subject 601, and the TOF sensor 802 in this embodiment. Since D in the diagram is a known value due to distance measurement by the TOF sensor 802, the elevation angle θ between the light-emitting element 207 and the image sensor 203 can be calculated from the following equation (8). θ=arktan(L / 2D) (8)

[0085] The distance A from the image sensor 203 to the subject 601 can be calculated from the above-mentioned equation (1). In this way, the flap angle θ to be set and the distance A to be focused can be calculated from the distance measurement results of the TOF sensor 802, so it is possible to change the flap angle and adjust the focus simultaneously. Here, a method for measuring the distance D using the TOF sensor 802 has been described, but the TOF sensor 802 may also be arranged adjacent to the image sensor 203 to measure the distance A. In that case, the flap angle θ can be calculated from the following equation (9). θ=arksin(L / 2A) (9)

[0086] In the fourth embodiment, a distance measuring means is added to the first embodiment, so the user does not need to search for the elevation angle θ that will fit the subject 601 on the display 212, and photography can be performed more easily. <Embodiment 5>

[0087] In the fifth embodiment, an example of a configuration in which the camera head 301 is divided will be described. Figures 25(A) and (B) show the imaging device 100 as viewed obliquely from the front. What was a single camera head 301 in Figure 3 is divided into three parts in Figure 25(A): a first camera head 901, a second camera head 902, and a fixed part 903, which is a housing. A light emitting element 207 is disposed in the first camera head 901, and a second support member 201 that supports an imaging element 203 and a lens with a focus mechanism 202 is disposed in the second camera head 902.

[0088] In this embodiment, the first support member 404 and the second support member 201 are the first camera head 901 and the second camera head 902. Rotation shafts are provided on the bottom surfaces of the first camera head 901 and the second camera head 902, respectively. The two rotation shafts pass through holes (not shown) provided in the upper part of the fixed part 903 and are connected to a rotation means provided in the fixed part 903. Therefore, the first camera head 901 and the second camera head 902 are configured to rotate as shown in FIG. 25(B) via the rotation shafts due to the rotation of the motors 401 and 402 provided in the fixed part. This configuration has the advantage that when the user sets the elevation angle θ, it is easy to recognize the direction in which the light emitting element 207 and the image sensor 203 are facing, making the setting easier. <Other>

[0089] The disclosure of the above-described embodiment includes the following configurations. (Configuration 1) a light emitting element that irradiates a subject with terahertz waves; an imaging element that detects terahertz waves reflected from a subject; an imaging optical system including a focus lens that forms an image of the terahertz waves reflected by the subject on the imaging element; a support member that supports the light-emitting element; a housing that supports the support member; a position changing means for changing the position of the support member relative to the housing; a focus changing unit provided in the imaging optical system and configured to change the position of the focus lens; an input means for inputting set distance information, which is a set value of the distance from the imaging element to the subject; an execution means for executing, based on the set distance information, changing the attitude of the support member by the attitude change means and changing the position of the focus lens by the focus change means. (Configuration 2) a light emitting element that irradiates a subject with terahertz waves; an imaging element that detects terahertz waves reflected from a subject; an imaging optical system including a focus lens that forms an image of the terahertz waves reflected by the subject on the imaging element; a first support member that supports the light emitting element; a second support member that supports the image sensor and the imaging optical system; a housing that supports the first support member and the second support member; a first position changing means for changing the position of the first support member relative to the housing; a second position changing means for changing the position of the second support member relative to the housing; a focus changing unit provided in the imaging optical system and configured to change the position of the focus lens; an input means for inputting set distance information, which is a set value of the distance from the imaging element to the subject; an execution means for executing, based on the set distance information, changing the attitude of the first support member by the first attitude change means, changing the attitude of the second support member by the second attitude change means, and changing the position of the focus lens by the focus change means. (Configuration 3) the first attitude changing means is a first rotation means that rotates the first support member relative to the housing, the second attitude changing means is a second rotation means that rotates the second support member relative to the housing, The imaging device described in configuration 2, wherein the execution means rotates the first support member using the first rotation means, rotates the second support member using the second rotation means, and changes the position of the focus lens using the focus change means, based on the set distance information. (Configuration 4) a rotation axis of the first support member is a first axis that is perpendicular to a plane that includes a straight line connecting a center of the light-emitting element and a center of the imaging element and a straight line that passes through a midpoint of the straight line and extends toward a subject, and that passes through the center of the light-emitting element; a rotation axis of the second support member is a second axis that passes through a center of the imaging element and is parallel to the first axis; The imaging device described in configuration 3, wherein the direction in which the execution means rotates the first support member by the first rotation means is opposite to the direction in which the execution means rotates the second support member by the second rotation means, and the angle in which the first support member is rotated by the first rotation means is the same as the angle in which the second support member is rotated by the second rotation means. (Configuration 5) the first rotation means includes a rotatable first drive source and a first transmission mechanism that transmits rotation of the first drive source to the first support member; The imaging device described in configuration 4, wherein the second rotation means has a rotatable second drive source and a second transmission mechanism that transmits the rotation of the second drive source to the second support member. (Configuration 6) the first rotation means includes a rotatable first drive source and a first transmission mechanism that transmits rotation of the first drive source to the first support member; 5. The imaging device according to configuration 4, wherein the second rotation means has a second transmission mechanism that transmits the rotation of the first drive source to the second support member. (Configuration 7) the first attitude changing means is a first moving means that moves the position of the first support member, the second attitude changing means is a second moving means that moves the position of the second support member, The imaging device described in configuration 2, characterized in that the execution means moves the position of the first support member using the first movement means, moves the position of the second support member using the second movement means, and changes the position of the focus lens using the focus change means, based on the set distance information. (Configuration 8) the moving direction of the first support member and the moving direction of the second support member are directions that are parallel to a plane that includes a straight line connecting the center of the light-emitting element and the center of the image sensor and a first straight line that passes through a midpoint of the straight line and extends toward a subject, and that intersect with the first straight line; The imaging device described in configuration 7, characterized in that the direction and distance of movement of the center of the light-emitting element by the first moving means are in a line-symmetric relationship with the direction and distance of movement of the center of the imaging element by the second moving means about the first straight line. (Configuration 9) 3. The imaging device according to configuration 1 or 2, further comprising a display means for displaying an image captured by the imaging element. (Configuration 10) 3. The imaging device according to configuration 1 or 2, wherein the input means is an operation unit that allows a user to input the set distance information. (Configuration 11) The imaging device described in configuration 2 further comprises a distance measurement means capable of measuring the distance to a subject, and the execution means executes the first attitude change means to change the attitude of the first support member, the second attitude change means to change the attitude of the second support member, and the focus change means to change the position of the focus lens, based on the measurement result of the distance measurement means and the set distance information. (Configuration 12) a light emitting element that irradiates a subject with terahertz waves; an imaging element that detects terahertz waves reflected from a subject; an imaging optical system including a focus lens that forms an image of the terahertz waves reflected by the subject on the imaging element; a support member that supports the light-emitting element; a housing that supports the support member; a position changer for changing the position of the support member relative to the housing; a focus changing unit provided in the imaging optical system for changing the position of the focus lens; an input means for inputting set distance information, which is a set value of the distance from the imaging element to the subject; A control method for an imaging device having a step of inputting the set distance information into the input means; changing the attitude of the support member by the attitude changing means and changing the position of the focus lens by the focus changing means based on the set distance information; 10. A method for controlling an imaging device, comprising:

[0090] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. [Explanation of symbols]

[0091] 100 Imaging device 101 Imaging optical system 102 Focus change method 103 Imaging unit 104 Second rotating means 105 Lighting Department 106 First rotating means 107 Control Unit 108 Display section 109 Input section

Claims

1. a light emitting element that irradiates a subject with terahertz waves; an imaging element that detects terahertz waves reflected from a subject; an imaging optical system including a focus lens that forms an image of the terahertz waves reflected by the subject on the imaging element; a support member that supports the light-emitting element; a housing that supports the support member; a position changing means for changing the position of the support member relative to the housing; a focus changing unit provided in the imaging optical system and configured to change the position of the focus lens; an input means for inputting set distance information, which is a set value of the distance from the imaging element to the subject; an execution means for executing, based on the set distance information, changing the attitude of the support member by the attitude change means and changing the position of the focus lens by the focus change means.

2. a light emitting element that irradiates a subject with terahertz waves; an imaging element that detects terahertz waves reflected from a subject; an imaging optical system including a focus lens that forms an image of the terahertz waves reflected by the subject on the imaging element; a first support member that supports the light emitting element; a second support member that supports the image sensor and the imaging optical system; a housing that supports the first support member and the second support member; a first position changing means for changing the position of the first support member relative to the housing; a second position changing means for changing the position of the second support member relative to the housing; a focus changing unit provided in the imaging optical system and configured to change the position of the focus lens; an input means for inputting set distance information, which is a set value of the distance from the imaging element to the subject; an execution means for executing, based on the set distance information, changing the attitude of the first support member by the first attitude change means, changing the attitude of the second support member by the second attitude change means, and changing the position of the focus lens by the focus change means.

3. the first attitude changing means is a first rotation means that rotates the first support member relative to the housing, the second attitude changing means is a second rotation means that rotates the second support member relative to the housing, 3. The imaging device according to claim 2, wherein the execution means rotates the first support member using the first rotation means, rotates the second support member using the second rotation means, and changes the position of the focus lens using the focus change means, based on the set distance information.

4. a rotation axis of the first support member is a first axis that is perpendicular to a plane that includes a straight line connecting a center of the light-emitting element and a center of the imaging element and a straight line that passes through a midpoint of the straight line and extends toward a subject, and that passes through the center of the light-emitting element; a rotation axis of the second support member is a second axis that passes through a center of the imaging element and is parallel to the first axis; 4. The imaging device according to claim 3, wherein the direction in which the execution means rotates the first support member by the first rotation means is opposite to the direction in which the execution means rotates the second support member by the second rotation means, and the angle by which the first support member is rotated by the first rotation means is the same as the angle by which the second support member is rotated by the second rotation means.

5. the first rotating means includes a rotatable first driving source and a first transmission mechanism that transmits the rotation of the first driving source to the first support member; 5. The imaging device according to claim 4, wherein the second rotation means comprises a rotatable second drive source and a second transmission mechanism that transmits the rotation of the second drive source to the second support member.

6. the first rotating means includes a rotatable first driving source and a first transmission mechanism that transmits the rotation of the first driving source to the first support member; 5. The imaging device according to claim 4, wherein said second rotation means has a second transmission mechanism for transmitting the rotation of said first drive source to said second support member.

7. the first attitude changing means is a first moving means that moves the position of the first support member, the second attitude changing means is a second moving means that moves the position of the second support member, The imaging device described in claim 2, characterized in that the execution means moves the position of the first support member using the first movement means, moves the position of the second support member using the second movement means, and changes the position of the focus lens using the focus change means, based on the set distance information.

8. a moving direction of the first support member and a moving direction of the second support member are directions that are parallel to a plane that includes a straight line connecting the center of the light-emitting element and the center of the image sensor and a first straight line that passes through a midpoint of the straight line and extends toward a subject, and that intersect the first straight line; 8. The imaging device according to claim 7, wherein the direction and distance of movement of the center of the light-emitting element by the first moving means are symmetrical with respect to the first straight line to the direction and distance of movement of the center of the imaging element by the second moving means.

9. 3. The imaging apparatus according to claim 1, further comprising a display means for displaying an image captured by the imaging element.

10. 3. The imaging apparatus according to claim 1, wherein the input unit is an operation unit that allows a user to input the set distance information.

11. 3. The imaging device according to claim 2, further comprising a distance measuring means capable of measuring the distance to a subject, wherein the execution means executes, based on the measurement result of the distance measuring means and the set distance information, changing the attitude of the first support member by the first attitude change means, changing the attitude of the second support member by the second attitude change means, and changing the position of the focus lens by the focus change means.

12. a light emitting element that irradiates a subject with terahertz waves; an imaging element that detects terahertz waves reflected from a subject; an imaging optical system including a focus lens that forms an image of the terahertz waves reflected by the subject on the imaging element; a support member that supports the light-emitting element; a housing that supports the support member; a position changer for changing the position of the support member relative to the housing; a focus changing unit provided in the imaging optical system for changing the position of the focus lens; an input means for inputting set distance information, which is a set value of the distance from the imaging element to the subject; A control method for an imaging device having a step of inputting the set distance information into the input means; changing the attitude of the support member by the attitude changing means and changing the position of the focus lens by the focus changing means based on the set distance information; 10. A method for controlling an imaging device, comprising:

Images