Transmitting devices, measurement systems, camera systems

Abstract

To provide a suitable optical system for a transmitter device using terahertz waves.SOLUTION: A transmitter device includes: a plurality of transmitter sections each of which has a plurality of oscillating elements oscillating terahertz waves and a coupling line connecting the plurality of oscillating elements; and an optical section provided over the plurality of transmitter sections and having a plurality of optical elements. Each of the plurality of transmitter sections has a face on the side of the optical section that includes an oscillation region in which the plurality of oscillation elements are arranged, and the optical section is located in a far field of terahertz waves with respect to the face.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a transmitting device, a measurement system, and a camera system. [Background technology]

[0002] Patent Document 1 discloses a configuration related to a camera system using terahertz waves. The camera system described in Patent Document 1 has a set of one illumination unit equipped with multiple terahertz generating elements and one illumination optical system provided corresponding to the illumination unit. Terahertz waves generated from the terahertz generating elements are imaged on each subject by the illumination optical system. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2018-087725 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to increase the output of terahertz waves, it has been considered to increase the number of pairs of illumination units and illumination optical systems. However, Patent Document 1 does not provide a detailed consideration of what to do with the illumination optical systems when multiple pairs are provided.

[0005] Therefore, an object of the present invention is to provide an optical system suitable for a transmitter, a measurement system, and a camera system that use terahertz waves. [Means for solving the problem]

[0006] One aspect of the present invention is a plurality of transmitting units each having a plurality of oscillation elements that oscillate terahertz waves and coupling wires that connect the plurality of oscillation elements; an optical unit that is provided on the plurality of transmitting units and has a plurality of optical elements; a support unit that supports the optical unit; and a first member on which the support unit is arranged, wherein each of the plurality of transmitting units has a surface on the optical unit side that includes an oscillation region in which the plurality of oscillation elements are arranged, and the distance between the surface and the optical unit is 2D 2 Another aspect of the present invention is a transmitting device comprising: a plurality of transmitting units each having a plurality of oscillation elements that oscillate terahertz waves and a coupling wire connecting the plurality of oscillation elements; and an optical unit provided on the plurality of transmitting units and having a plurality of optical elements, wherein the number of the plurality of transmitting units is equal to the number of the plurality of optical elements, and each of the plurality of transmitting units has a surface on the optical unit side that includes an oscillation region in which the plurality of oscillation elements are arranged, and the distance between the surface and the optical unit is within a range of 2D / λ, where λ is the wavelength of the terahertz waves and D is the length of the oscillation region. 2 / λ or more . [Effects of the Invention]

[0007] According to the present invention, it is possible to provide an optical system suitable for a transmitter, a measurement system, and a camera system that use terahertz waves. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram for explaining the configuration of a camera system according to a first embodiment. [Figure 2] FIG. 10 is a schematic diagram illustrating the configuration of a camera system according to a second embodiment. [Figure 3] FIG. 10 is a flowchart illustrating the operation of the camera system according to the second embodiment. [Figure 4] FIG. 10 is a flowchart illustrating the operation of the camera system according to the second embodiment. [Figure 5] FIG. 10 is a schematic diagram illustrating the configuration of a camera system according to a third embodiment. [Figure 6] FIG. 10 is a flowchart illustrating the operation of the camera system according to the third embodiment. [Figure 7] FIG. 10 is a schematic diagram for explaining the configuration of a camera system according to a fourth embodiment. [Figure 8] FIG. 10 is a flowchart illustrating the operation of the camera system according to the fourth embodiment. [Figure 9] 1 is a schematic diagram illustrating the configuration of a transmitting device according to a first embodiment. [Figure 10] FIG. 10 is a schematic diagram illustrating the configuration of a transmitting device according to a fifth embodiment. [Figure 11] FIG. 10 is a schematic diagram illustrating the configuration of a transmitting device according to a fifth embodiment. [Figure 12] FIG. 10 is a schematic diagram for explaining the configuration of a measurement system according to a sixth embodiment. [Figure 13] FIG. 13 is a schematic diagram for explaining a camera system according to a seventh embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a transmitter, a measurement system, and a camera system using terahertz waves will be described in detail with reference to the drawings. In the description of each embodiment, a description of the same configuration as in other embodiments may be omitted. Furthermore, each embodiment can be appropriately modified or appropriately combined with other embodiments.

[0010] In the following description, terahertz waves refer to electromagnetic waves in a frequency range of 10 GHz to 100 THz, more preferably 30 GHz to 30 THz.

[0011] When increasing the number of pairs of illumination units and illumination optical systems to increase the output of terahertz waves, the inventors have discovered the following. As the number of pairs of illumination units and illumination optical systems increases, multiple light source patterns originating from the illumination units are imaged on the subject. At this time, light source unevenness occurs due to the multiple light source patterns. Light source unevenness refers to the variation in intensity on any surface, in this case the surface of the subject. Because terahertz waves have a long wavelength, they are specularly reflected by many subjects. Therefore, the camera system detects not only the image of the subject, but also the light source unevenness imaged on the subject. Therefore, in many applications using terahertz waves, it is important to reduce the effects of this light source unevenness. An embodiment will be described below.

[0012] (Embodiment 1) The camera system according to this embodiment will be described with reference to FIGS.

[0013] Fig. 1 is a schematic diagram for explaining the configuration of a camera system according to embodiment 1. Fig. 1(a) is a schematic diagram for explaining the system configuration, and Fig. 1(b) shows the irradiation pattern of terahertz waves in Fig. 1(a). The configuration of the terahertz camera system will first be explained using Fig. 1(a).

[0014] The terahertz camera system has a detection device 101, which is a terahertz camera, and a transmission device 102. Terahertz waves 112 are emitted from the transmission device 102 and irradiated onto an object 111. The detection device 101 detects the terahertz waves 112 from the object 111. In FIG. 1(a), the object 111 is shown as an arrow indicating the direction for the sake of explanation, but it may be any object. Surface 113 is the observation plane of the terahertz camera.

[0015] The transmitting device 102 has a plurality of transmitting units 103, a member 104, and an optical unit 105. Each of the plurality of transmitting units 103 has a plurality of oscillation elements. Details of the oscillation elements will be described with reference to FIG. 9. The transmitting device 102 has a plurality of transmitting units 103, each having a plurality of oscillation elements that oscillate terahertz waves, and an optical unit 105 provided on the plurality of transmitting units 103. Each of the plurality of oscillation elements oscillates terahertz waves. An oscillation element capable of oscillating terahertz waves includes, for example, a negative resistance element and a resonator. The oscillation element includes, for example, a resonant tunneling diode (RTD) as a negative resistance element and an antenna. The oscillation element is not limited to this, and any semiconductor having gain for the terahertz waves used can be used. For example, a Gunn diode, an IMPATT diode, etc. can be used. A detailed configuration of the transmitting unit 103 will be described later. FIG. 1(a) schematically illustrates a portion of the multiple transmitters 103 arranged in an arbitrary one row and three columns. The member 104 can also be referred to as a circuit board. The member 104 can be, for example, a printed circuit board. Alternatively, a ceramic substrate or a silicon-based semiconductor substrate can be used. The member 104 may be arranged with multiple transmitters 103 and may also be arranged with a circuit section for operating the multiple transmitters 103. The optical section 105 has at least one optical element, for example, multiple optical elements 106. The optical section 105 has a portion extending across the multiple optical elements 106 and is configured to form a so-called lens plate so that the multiple optical elements 106 are integrated. The optical element 106 is, for example, a lens, and in this case, is an upwardly convex lens array. The optical element 106 is preferably formed from a material transparent to terahertz waves. Examples of transparent materials include high-density polyethylene (HDPE), high-resistivity silicone, and Teflon (registered trademark) (Poly Tetra Fluoro Ethylene: PTFE). The multiple optical axes 129 represent the optical axes of the multiple optical elements 106. The optical axes 129 may coincide with the center of the region where emission of the emission unit 103 occurs in a plan view of the member 104.In a cross-sectional view, the upper surface of transmitting unit 103 may coincide with the front focal point of optical element 106. Here, the upper surface of transmitting unit 103 can also be said to be the surface on the optical unit side.

[0016] The detection device 101 includes an optical unit 107, a detection unit 108, and a member 109. The optical unit 107 includes an optical element, such as a lens, of an imaging optical system. The detection unit 108 includes a detection element capable of detecting terahertz waves. The detection element capable of detecting terahertz waves is, for example, an antenna including a rectifying element and a conductor. The rectifying element may be a rectifying diode such as a Schottky barrier diode or a diode using a pn junction. The member 109 can also be referred to as a circuit board. For example, a printed circuit board or the like may be used for the member 109. Multiple detection units 108 are arranged on the member 109, and a circuit unit for operating the multiple detection units 108 may also be arranged thereon. The multiple detection units 108 correspond to each pixel in a terahertz camera. In addition to a printed circuit board, a ceramic substrate or a silicon-based semiconductor substrate may also be used for the member 109. The optical unit 107 includes at least one optical element. For example, the optical element may be a lens of an imaging optical system. The optical element can be formed from, for example, the above-mentioned high-density polyethylene, high-resistivity silicon, Teflon, etc. Optical axis 116 represents the optical axis of the optical element of optical unit 107. Optical axis 116 may coincide with the center of the detectable area of ​​detection unit 108 in a plan view of member 109.

[0017] The irradiation pattern will be described using FIG. 1(b). In the camera system, terahertz waves 112 are emitted via the optical unit 105. An example of the irradiation pattern at this time is shown as irradiation pattern 121. The irradiation pattern 121 is the spatial intensity distribution of the terahertz waves. Terahertz waves emitted from multiple emitters 103 are combined to form a single irradiation pattern 121. The top surface of the emitter 103 is the generation surface of the terahertz waves. If the top surface of the emitter 103 is located on the optical element 106 side with respect to the front focal point of the optical element 106, the terahertz waves generated from each optical element 106 spread and propagate as spherical waves. At this time, if the subject 111 or the detection device 101 is sufficiently far from the optical unit 105, the radius of the sphere becomes large, and for example, it can be considered as a plane wave near the optical axis 116. Therefore, the irradiation pattern 121 can be considered as a superposition of multiple plane waves emitted by multiple transmitters 103, and can be approximated to a uniform line (surface) as shown in Fig. 1(b). With this configuration, the irradiation pattern 121 can be considered as a superposition of multiple plane waves, and therefore, intensity variations in the irradiation pattern 121, which are caused by light source unevenness, can be suppressed.

[0018] In the above configuration, of the terahertz waves 112 propagating as spherical waves, a portion of the terahertz waves 112 near the optical axis 116, which can be considered as plane waves, is used for imaging. To improve the utilization efficiency of the generated terahertz waves, the upper surface of the transmitting unit 103 may be disposed at the front focal point of the optical element 106. In this case, the terahertz waves generated from the optical element 106 propagate as plane waves approximately parallel to the optical axis 129. The irradiation pattern 121 is a collective pattern of multiple terahertz waves generated from each optical element 106 and propagating as parallel light, and can be approximately parallel to the emission surface. In other words, the collective pattern is formed by adjacent terahertz waves propagating as parallel light, and has an intensity distribution that follows the profile of the irradiation pattern 121 as a whole.

[0019] In the present invention, parallel light is light having an intensity of 1 / e 2The terahertz wave propagates with a beam divergence angle of 15 degrees or less, which is attenuated at a certain angle. In this case, a typical terahertz camera system is obtained (for example, the distance between the transmitter 102 and the detector 101 is several meters, and the diameter of the optical section 105 of the detector 101 is several tens to several hundreds of mm). With this configuration, the majority of the light rays of the generated terahertz wave 112 can be taken into the detector 101, which makes it easy to improve the signal-to-noise ratio (SNR) of the system. More preferably, the intensity is 1 / e 2 The beam divergence angle at which this occurs is 2 degrees or less. In this case, it can be assumed that the transmitting device 102 is located at almost infinity when viewed from the detecting device 101, which improves the degree of freedom in setting the distance between the transmitting device 102 and the detecting device 101. Also, parallel light is light that is parallel to the transmitting device 102 when the distance between adjacent optical axes 129 is d and the distance between the transmitting device 102 and the detecting device 101 is A, and the intensity is 1 / e 2 The beam divergence angle at which the beam convergence occurs may be defined as an angle at which the beam divergence angle is 2×Atan(d / A) or less. In this case, the interference of the terahertz waves in the irradiation pattern 121 can be limited to adjacent terahertz waves or simplified for the terahertz waves output from the optical unit 105, making it easier to predict and control the intensity distribution of the irradiation pattern 121. This makes it easier to suppress unevenness in the light source. In addition, the diameter of the propagating optical element 106 is set to the beam diameter (intensity 1 / e 2 It is preferable that the spacing between adjacent optical axes 129 is approximately equal to the diameter of the beam (a diameter defined by the beam width such that .gtoreq..times ...

[0020] Terahertz waves 112 are reflected by the object 111 and enter the optical unit 107 of the detection device 101. When irradiation pattern 121 of terahertz waves 112 is parallel light, it can be assumed that the transmission device 102 is located at infinity relative to the detection device 101. In this case, irradiation pattern 121 is imaged as irradiation pattern 122 on the back focal plane 114 of the optical unit 107, and irradiation pattern 123 is incident on the imaging plane 115 of the optical unit 107. The detection unit 108 is located on the imaging plane 115. Irradiation pattern 122 has an intensity pattern with a concave-convex shape that follows the shape of the transmission device 103. Irradiation pattern 123 appears on the imaging plane 115 as a pattern in which the concave-convex shape of the light source that follows the shape of the transmission device 103 is defocused. In other words, the light source pattern transferred to the irradiation pattern 122 is a secondary light source, and the light source pattern that spreads and propagates from this secondary light source is incident on the imaging plane 115 as the irradiation pattern 123. The subject image 110 is an image of the subject 111 that is formed on the imaging plane 115 by the optical unit 107. Here, the transmitting device 102 having a uniform linear irradiation pattern can also be called a line light source. If the transmitting unit 103 is provided in the depth direction in FIG. 1(b), the irradiation pattern becomes a surface. The transmitting device 102 having a planar irradiation pattern can also be called a surface light source. The irradiation pattern 123 is incident on the detecting unit 108 in a defocused state. In other words, the intensity unevenness, which is the intensity pattern of the uneven light source that follows the shape of the transmitting unit 103, is incident on the detecting unit 108 in a defocused state. Because the intensity unevenness is defocused, the intensity variation of the irradiation pattern can be reduced.

[0021] The following describes details of the transmitting device 102. Fig. 9 is a schematic diagram for explaining the configuration of the transmitting device 102 according to this embodiment.

[0022] FIG. 9(a) is a schematic cross-sectional view of the transmitting device 102, and FIG. 9(b) is a schematic top view of the transmitting device 102. FIGS. 9(a) and 9(b) correspond to each other. One transmitting unit 103 is arranged corresponding to one optical element 106. The optical unit 105 has multiple optical elements 106, and the number of multiple transmitting units 103 is equal to the number of multiple optical elements 106. The optical elements 106 are upwardly convex lenses, and there are no gaps between adjacent lenses. Although the lenses are shown to have a circular shape when viewed from above, this is not limiting. There may be gaps between the lenses, and the lenses may have a rectangular, elliptical, or hexagonal shape.

[0023] FIG. 9(c) is a schematic and projected view of the transmitting device 102. FIG. 9(c) is a view of the main components projected from above, with the direction from the member 104 toward the optical element 106 in FIG. 9(a) as the top. FIG. 9(c) can also be considered a more detailed view of FIG. 9(b). In this embodiment, the multiple transmitting units 103 and the multiple optical elements 106 are arranged at equal pitches. Specifically, the distance between the center of one transmitting unit 103 and the center of another adjacent transmitting unit 103 is approximately equal to the distance between the center of one optical element 106 and the center of another adjacent optical element 106. Here, the centers of the transmitting units 103 and the optical elements 106 are located at point 124, but they do not have to coincide. The multiple optical elements 106 are arranged so as to be in contact with each other, but may also be arranged so as to be spaced apart. The multiple transmitting units 103 are arranged so as to be spaced apart from each other, but may also be arranged so as to be in contact with each other. 9(c), the boundary of optical element 106 is located in the space between transmitting units 103, that is, in the gap portion. In addition, in plan view, optical element 106 includes member 118 of transmitting unit 103. With this configuration, terahertz waves can be emitted without leakage.

[0024] FIG. 9(c) shows the detailed configuration of the transmitting unit 103. Two or more oscillators 127 are arranged in each transmitting unit 103. Here, the oscillators 127 are arranged in three rows and three columns. The oscillators 127 are connected to each other by bond lines 128, and can operate by synchronizing the phases of the terahertz waves oscillated by the oscillators 127. In detail, by adjusting the phase synchronization state, it is possible to use the characteristics of radio waves to adjust the beam directivity (beam divergence angle and front intensity) of the terahertz waves generated from the transmitting unit 103. In our investigation, with a single oscillator 127, the terahertz waves are isotropically diffused, and therefore, for example, the intensity is 1 / e 2The beam divergence angle is approximately 100 degrees. However, by synchronizing several dozen oscillators 127 via coupling wires 128, the beam divergence angle can be reduced to approximately one-fifth of the original size. By reducing the beam divergence angle, the size of optical element 106 can be reduced while suppressing eclipse of the terahertz waves near the boundaries of optical element 106. As a result, the mounting density of transmitter 103 and optical element 106 can be increased, making it easier to increase the power density of the terahertz waves. This differs from mounting an array lens on a light-emitting diode (LED). With LEDs, it is difficult to synchronize multiple LEDs and adjust the beam directionality. Even with multiple LEDs, the beam divergence angle remains approximately 100 degrees, which increases the lens diameter of the array lens. Therefore, it is difficult to achieve both increased power density and compactness of the device. While focusing the beam with a microlens and arranging a lens array is considered as a means to increase the power density of LEDs, a separate process for fabricating the microlenses is required. In other words, the transmitting unit 103 of the present invention achieves the function of converging a beam with this microlens by synchronizing multiple oscillation elements 127, and the device configuration is simpler than that of an LED device. The area where multiple oscillation elements 127 are arranged can also be called the oscillation area. The center or center of gravity of the oscillation area is preferably located at point 124. It is desirable to arrange the oscillation area so that the center of the oscillation area is aligned with the optical axis of the optical element 106. The number of oscillation elements 127 in each transmitting unit 103 is not limited to the number shown in Figure 9(c). The top surface of the transmitting unit 103 may be the top surface of the oscillation area.

[0025] Furthermore, one oscillation element 127 can be arranged to be located at the center of the oscillation region. The oscillation element 127 can also be arranged so that the center of the resonator and the center of the oscillation region are aligned.

[0026] FIG. 9(d) is a schematic diagram showing a cross section of an embodiment of the transmitting device 102. The configuration of the transmitting device 102 is not limited to this. FIG. 9(d) can also be considered a more detailed version of the configuration of FIG. 9(a). The transmitting device 102 has multiple transmitting units 103 arranged therein, and a support unit 120 arranged on a member 104. The optical unit 105 is connected to the member 104 via the support unit 120. The optical unit 105 and the support unit 120 may be connected using a resin such as an adhesive between them, or may be connected using another member. The optical unit 105 may be fixed to the support unit 120. As described above, multiple transmitting units 103 are provided on the member 104. The transmitting unit 103 has a member 118 on which multiple oscillation elements 127 are arranged, and a member 117 on which a circuit for operating the multiple oscillation elements 127 is arranged. The transmitting unit 103 includes a member 119 on which the members 118 and 117 are arranged. Here, the term "member" refers to a semiconductor substrate or a circuit board. A member having a function different from members 118 and 117 may be disposed on member 119 of transmitting unit 103.

[0027] The position of the optical unit 105 will be described using FIG. 9(d). The position of the optical unit 105 is desirably located in the "far field" with respect to the terahertz waves emitted by the transmitting unit 103. The transmitting unit 103 has a surface 125. Surface 125 may be the upper surface of the oscillation region, the upper surface of the member 118, i.e., the upper surface of the transmitting unit 103. The lower surface of the optical unit 105 is surface 126. If the length between surfaces 125 and 126 is L, for example, if the length of the oscillation region of the transmitting unit 103 is D and the wavelength of the terahertz waves is λ, then L is 2D. 2 / λ or more. By placing the optical unit 105 in the "far field," the beam shape of the terahertz waves generated from the oscillation region can be controlled independently of the physical properties of the materials constituting the optical unit 105. Then, similar to beam shaping of visible light, the terahertz waves can be adjusted to be approximately parallel rays via the optical unit 105. By making the terahertz waves from the transmitting device 102 resemble parallel rays, the transmitting device 102 can be virtually placed at infinity from the viewpoint of the detecting device 101. Therefore, the intensity unevenness originating from the light source is incident on the detecting unit 108 in a defocused state, and the intensity unevenness of the detected signal can be reduced.

[0028] Furthermore, if the directivity of the terahertz wave beam can be designed including the components of the optical unit 105, the position of the optical unit 105 may be in the "near field." In this case, the length L is 2D 2 In this case, optical element 106 of optical unit 105 is located close to transmitting unit 103, so optical element 106 can be made smaller. This is advantageous in that the mounting density of transmitting unit 103 can be increased, and power density can be increased.

[0029] Here, surface 125 may be, for example, the upper surface of a conductor that constitutes the antenna of oscillation element 127 of transmitting unit 103. Therefore, when determining the position of optical unit 105, the distance from the upper surface of the conductor that constitutes the antenna to optical unit 105 can be used. Note that, although wavelength is used when determining the position of optical unit 105, there is generally variation in the emitted wavelength. The variation is, for example, ±1% of the desired wavelength. The position of optical unit 105 can be determined with a margin corresponding to the variation.

[0030] The intensity distribution emitted from the transmitting unit 103 having multiple oscillation elements 127 represents the shape of the oscillation region (a square shape in the case of FIG. 9 ), and by arranging multiple transmitting units 103, the intensity distribution becomes the shape of a collection of multiple oscillation regions. When the detecting device 101 acquires all the terahertz wave light beams, the irradiation pattern 122 has an intensity distribution that follows this shape. However, if some of the light beams are eclipsed, the shape of the oscillation region cannot be reproduced, and the irradiation pattern becomes a collection of so-called Gaussian distributions. This configuration makes it possible to provide a stronger transmitting device 102. Furthermore, by including an optical unit 105 in such a transmitting device 102, it becomes easier to provide the desired waveform as described above.

[0031] The configuration of this embodiment can provide an optical section suitable for a transmitter using terahertz waves.

[0032] (Embodiment 2) The camera system according to this embodiment will be described with reference to FIGS. 2, 3, and 4. FIG.

[0033] FIG. 2 is a schematic diagram illustrating the configuration of a camera system according to a second embodiment. FIG. 2 is a schematic diagram corresponding to FIG. 1(b). In this embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and their description will be omitted. In FIG. 2, the camera system includes an intensity correction unit 231 and a correction lookup table 232 in addition to the components of the first embodiment. The intensity correction unit 231 is configured, for example, by a computing device such as a PC (Personal Computer) or a dedicated processing board equipped with an FPGA (Field Programmable Gate Array). The intensity correction unit 231 can also be considered a processing unit. The intensity correction unit 231 may be located inside or outside the detection device 101. The correction lookup table 232 may be configured, for example, by a database and stored in the cloud. The correction lookup table 232 manages correction data and coefficients for correcting terahertz images, such as the sensitivity, noise level, and reference signal intensity of the multiple detection units 108 (each pixel of the terahertz camera), corresponding to each pixel. The operation of such a camera system will be described with reference to FIGS.

[0034] 3 is a flow diagram for explaining the operation of the camera system of this embodiment, and simply shows the flow for creating or updating information for image processing. The camera system can perform the operations of steps S301 to S303.

[0035] Step S301 is a reference image acquisition step. In step S301, a reference image is acquired. The reference image is an image obtained of a reference object. The reference image is also an image obtained by directly observing a reference terahertz light source. Acquiring an image can also be referred to as acquiring image information, for example. The reference object is an object whose contents and constituent materials are known, and which has, for example, a uniform structure. The reference image includes an image of the terahertz waves emitted from the transmitting device 102 and an image showing the intensity distribution. Intensity distribution information can be acquired from the reference image. In step S301, image information 310 is acquired. The image information 310 includes information on an image 311 corresponding to the irradiation pattern 123 shown in FIG. 2.

[0036] Step S302 is an intensity correction information acquisition step. In step S302, intensity distribution information of the terahertz wave is acquired from a reference image. This information is used to create correction information. Based on information about an image 311 contained in image information 310, intensity correction information 312 is created. The intensity correction information 312 has, for example, a correction pattern 323 corresponding to the irradiation pattern 123. The correction pattern 323 includes coefficients for intensity correction and coordinate information of the image.

[0037] Step S303 is a lookup table creation or update step. In step S303, the intensity correction information acquired in step S302 is input to the correction lookup table 232. Step S303 shows the case where a new table is created and the case where an existing table is updated.

[0038] Through the above steps, information for image processing is created or updated. Steps S301 to S303 may be performed as an operation when the camera system is started up, or may be performed after a given period of time has elapsed since the camera system started operating. They may also be performed when the camera system is shipped. Steps S301 to S303 may also be repeatedly performed at any timing. For example, steps S301 to S303 may be performed by operating the transmitting device 102 under given conditions, and steps S301 to S303 may be performed by operating the transmitting device 102 under different conditions.

[0039] 4 is a flow diagram for explaining the operation of the camera system of this embodiment, and shows a simplified flow of image processing. The camera system is capable of performing the operations of steps S401 to S403.

[0040] Step S401 is a terahertz image acquisition step. Step S401 is a so-called imaging step. The acquired terahertz image is an image obtained by detecting the reflected terahertz waves transmitted by transmitting device 102 in FIG. 2 by subject 111 and then detected by detecting device 101. The acquired terahertz image can also be referred to as image information 410. The image information 410 includes image 311 including irradiation pattern 123 shown in FIG. 3 and subject image 110.

[0041] Step S402 is an intensity correction step. In step S402, the image information 410 is corrected using intensity correction information in the correction lookup table 232. The intensity correction information is, for example, the correction pattern 323 in FIG. 3, and for example, processing is performed to remove information about the correction pattern 323 from the image information 410. The removal processing is, for example, a subtraction process.

[0042] Step S403 is a terahertz image output step. In step S403, a corrected terahertz image is output. Specifically, in step S403, image information 411 corrected in step S402 is output. In the image information 411, the portion of the correction pattern 323 is corrected, and the subject image 110 can be obtained.

[0043] The camera system of this embodiment can suppress information about light source unevenness from a terahertz image in which the light source unevenness, the irradiation pattern 123, and the subject image 110 are mixed, thereby making it possible to obtain a more suitable terahertz image that mainly consists of the subject image 110.

[0044] (Embodiment 3) The camera system according to this embodiment will be described with reference to FIGS.

[0045] FIG. 5 is a schematic diagram illustrating the configuration of a camera system according to a third embodiment. FIG. 5 is a schematic diagram corresponding to FIG. 2. In this embodiment, the same components as those in the second embodiment are denoted by the same reference numerals, and their description will be omitted. In FIG. 5, the camera system includes a position monitoring unit 533 in addition to the components of the second embodiment. The position monitoring unit 533 is configured, for example, using image processing technology related to position detection and position monitoring with reference to the terahertz image output by the camera system. It is sufficient for the position monitoring unit 533 to at least detect the position. The operation of such a camera system will be described with reference to FIG. 6. Regarding the flow in FIG. 6, detailed description of the same flows as those in FIGS. 3 and 4, for example, steps with similar names, may be omitted.

[0046] 6 is a flow diagram for explaining the operation of the camera system of this embodiment, and simply shows the flow for updating information for image processing. The camera system can perform the operations of steps S601 to S605.

[0047] Step S601 is a terahertz image acquisition step. Step S601 is a so-called imaging step. The acquired terahertz image is an image obtained by detecting the reflected terahertz waves transmitted by the transmitting device 102 in FIG. 5 after they are reflected by the object 111 using the detecting device 101. The acquired terahertz image can also be referred to as image information 610. The image information 610 includes the image 311 including the irradiation pattern 123 shown in FIG. 3 and the object image 110. In the image information 610, the correction region derived from the intensity correction information obtained in the flow of FIG. 3 is shown as correction region 624.

[0048] Step S602 is a correction area acquisition step. In step S602, a correction area 625 is acquired from the image 311 of the image information 611. Then, position information of the correction area 625 is acquired, and the amount of deviation from the position of the correction area 624 is acquired.

[0049] Step S603 is a lookup table update processing step. Based on the deviation amount obtained in step S602, at least the position information of the intensity correction information in the correction lookup table 232 is updated. If the deviation amount is zero, the position information of the intensity correction information in the correction lookup table 232 does not need to be updated.

[0050] Step S604 is an intensity correction step. The image information 610 is corrected using the intensity correction information in the updated correction lookup table 232. Here, the intensity correction information is, for example, the correction pattern 323 in FIG. 3, and since the position information has been updated, the area corresponding to the correction area 625 in the image information 611 corresponds to the position of the correction pattern 323.

[0051] Step S605 is a terahertz image output step. In step S605, image information 612 corrected in step S604 is output. In the image information 612, the portion of the correction pattern 323 is corrected, and the subject image 110 can be obtained.

[0052] 5 shows a signal path that directly connects the position monitoring unit 533 and the correction lookup table 232, but it may also be a signal path in which the intensity correction unit 231 is disposed between the position monitoring unit 533 and the correction lookup table 232. Furthermore, the position monitoring unit 533 and the intensity correction unit 231 may be configured on the same processing chip or processing board.

[0053] The configuration of this embodiment makes it possible to provide a camera system that can accurately correct a terahertz image even when the terahertz image is displaced from the intended correction area due to a change in the position or posture of the subject 111, for example.

[0054] (Embodiment 4) The camera system according to this embodiment will be described with reference to FIGS.

[0055] FIG. 7 is a schematic diagram illustrating the configuration of a camera system according to a fourth embodiment. FIG. 7 is a schematic diagram corresponding to FIG. 2. In this embodiment, the same components as those in the second embodiment are assigned the same reference numerals, and their description will be omitted. In FIG. 7, the camera system includes, in addition to the components of the second embodiment, an irradiation pattern prediction unit 735, a monitoring unit, specifically, a drive status monitoring unit 734, and a database 736. The drive status monitoring unit 734 may be configured with a sensor that measures the drive status of the transmitting device 102 (e.g., drive frequency, drive bias, internal device temperature, ambient temperature, etc.). The database 736 may be configured with a storage device that stores changes in the output beam shape and directivity of the terahertz wave in response to changes in the drive status. The irradiation pattern prediction unit 735 may be configured with a computing device that recalculates, for example, the intensity distribution and shape of the irradiation pattern 121 by referring to the drive status of the drive status monitoring unit 734 and information related to the terahertz wave in the database 736. The operation of such a camera system will be described with reference to FIG. 8. Regarding the flow in FIG. 8, detailed explanations of the same flows as those in FIGS. 3 and 4, for example, steps with similar names, may be omitted.

[0056] 8 is a flow diagram for explaining the operation of the camera system of this embodiment, and simply shows the flow for updating information for image processing. The camera system can perform the operations of steps S801 to S804.

[0057] Step S801 is a driving status information acquisition step. In step S801, the driving status monitoring unit 734 acquires driving status information of the transmitting device 102. The driving status information includes information that may cause a change in the output of the transmitting device 102, such as operating time, operating conditions, and changes in operating temperature.

[0058] Step S802 is an output prediction step. In step S802, the irradiation pattern prediction unit 735 refers to the driving state information to predict a change in the output of the transmitting device 102 and a change in the intensity distribution of the irradiation pattern 121. The irradiation pattern prediction unit 735 predicts changes in the output, beam shape, and directivity of the terahertz waves emitted by the transmitting unit 103 based on the operating state information acquired in step S801 and information on changes in the characteristics of the terahertz waves corresponding to the driving state stored in the database 736. The database 736 may be stored in a storage unit.

[0059] Step S803 is an irradiation pattern prediction step in which the irradiation pattern prediction unit 735 predicts the intensity distribution of the irradiation pattern, which is the light source unevenness, from the information on the plurality of terahertz waves obtained in step S802.

[0060] Step S804 is a lookup table updating step, in which the intensity correction information in the correction lookup table 232 is updated based on the irradiation pattern obtained in step S804.

[0061] Furthermore, if an output change is recognized when the output is predicted in step S802, it is also preferable to carry out the operation shown in FIG.

[0062] 8 shows a signal path that directly connects the irradiation pattern prediction unit 735 and the correction lookup table 232, but it may also be a signal path in which the intensity correction unit 231 is disposed between the irradiation pattern prediction unit 735 and the correction lookup table 232. The correction lookup table 232 and the database 726 may be stored in the same memory, and the irradiation pattern prediction unit 735 and the intensity correction unit 231 may be configured on the same processing chip or processing board.

[0063] The configuration of this embodiment makes it possible to provide a camera system that can correct for changes in light source unevenness that occur as the state of the device changes during operation.

[0064] (Embodiment 5) In this embodiment, a modified example of transmitting device 102 will be described with reference to Fig. 10 and Fig. 11. Fig. 10 and Fig. 11 are schematic diagrams for explaining the configuration of transmitting device 102 according to this embodiment. In Fig. 10 and Fig. 11, the same components as those in other drawings are given the same reference numerals, and their explanation will be omitted.

[0065] Modifications shown in Figures 10(a) and 10(b) are described below. Figure 10(a) is a schematic diagram showing a cross section of the transmitting device 102. Figure 10(b) is a schematic diagram of the transmitting device 102 corresponding to Figure 10(a). Figure 10(b) can also be considered a projection view. Figure 10(a) corresponds to Figure 9(a), and Figure 10(b) corresponds to Figure 9(b). The configuration of this example differs from Figures 9(a) and 9(b) in that the transmitting units 103 and corresponding optical elements 106 are arranged in two rows and three columns. The transmitting units 103 and corresponding optical elements 106 can be arranged two-dimensionally. With this configuration, the terahertz waves from the transmitting device 102 can function as a surface light source. Terahertz wave imaging is a specular reflection image, and the number of light rays traveling from the transmitting device 102 to the object 111 is equal to the number of light rays traveling from the object 111 to the detecting device 101. Therefore, by using the transmitting device 102 as a surface light source, the number of light rays can be increased, making it easier to grasp the shape of the subject 111. In the configuration of this example, similar to Figures 9(a) and 9(b), the optical unit 105 has multiple optical elements 106, and the number of multiple transmitting units 103 is equal to the number of multiple optical elements 106.

[0066] Modifications shown in Figures 10(c) and 10(d) will be described. Figure 10(c) is a schematic diagram showing a cross section of the transmitting device 102. Figure 10(d) is a schematic diagram of the transmitting device 102 corresponding to Figure 10(c). Figure 10(d) can also be considered a projection view. The optical element 106 in this example uses a semi-cylindrical lens. By using such an optical element 106, it is easier to align the optical element 106 with the transmitting unit 103 compared to an upwardly convex lens as shown in Figure 10(a). Note that the cross-sectional shape of the cylindrical lens does not have to be an upwardly convex curved surface, and may be trapezoidal or rectangular. Furthermore, the optical element 106 may be a lens with different curvatures in the vertical and horizontal directions in Figure 10(d). By varying the curvature in the vertical and horizontal directions and increasing the parameters for adjusting the beam shape, the degree of freedom in beam adjustment is improved, making it easier to adjust to the desired irradiation pattern 121, even if the directivity of the terahertz waves emitted by the transmitter 103 has anisotropic characteristics, for example.

[0067] Modifications shown in Fig. 10(e) and Fig. 10(f) will be described. Fig. 10(e) is a schematic diagram showing a cross section of the transmitting device 102. Fig. 10(f) is a schematic diagram of the transmitting device 102 corresponding to Fig. 10(e). Fig. 10(f) can also be considered a projection view. The optical element 106 of this example uses an upwardly convex lens having a groove structure 1041. Here, the groove structure 1041 is a concave-convex structure. The width and height difference of the concave-convex structure can be calculated, for example, by assuming that the terahertz wave is λ, 1 / 30λ or more and 1 / 10λ or less For example, the width and the height difference may be 5 μm or more and 35 μm or less, and more preferably 15 μm or more and 25 μm or less. In such groove structure 1041, weak diffusion of the terahertz wave occurs, so that the intensity distribution inside irradiation pattern 121 of the terahertz wave can be made uniform while maintaining the directivity and shape of irradiation pattern 121. Note that groove structure 1041 of this example can be applied to other optical elements.

[0068] Modifications shown in Figures 10(g) and 10(h) will be described. Figure 10(g) is a schematic diagram showing a cross section of a transmitting device 102. Figure 10(h) is a schematic diagram of the transmitting device 102 corresponding to Figure 10(g). Figure 10(h) can also be considered a projection view. In this example, the number of transmitting units 103 is smaller than the number of optical elements 106. That is, as shown in Figure 10(h), two transmitting units 103 are arranged and three optical elements 106 are arranged. Specifically, the three optical elements 106 include optical elements 1043, 1044, and 1045, which are arranged in this order along the first direction. The two transmitting units 103 include transmitting units 1046 and 1047, which are arranged in this order along the first direction. Optical element 1043 is located above transmitting unit 1046, optical element 1045 is located above transmitting unit 1047, and optical element 1044 is located on the boundary between transmitting units 1046 and 1047. For example, assume that due to misalignment between optical unit 105 and transmitting unit 1046, part of the terahertz waves that should be emitted from transmitting unit 1046 and input to optical element 1043 are input to optical element 1044. In this case, the misalignment state can be confirmed by monitoring the terahertz waves output from optical element 1044. In detail, alignment in the 1042 direction can be performed by minimizing the intensity of the terahertz waves output by optical element 1044. 10(h), emitting units 1046 and 1047 are disposed on both sides of optical element 1044, and alignment can be performed in the direction 1042 and the direction opposite to the direction 1042 by monitoring the intensity of the terahertz waves output from optical element 1044. With this configuration, for example, by monitoring the terahertz waves generated from optical element 1044, alignment of multiple emitting units with multiple optical elements can be facilitated.

[0069] A modified example shown in FIG. 10(i) will be described. FIG. 10(i) is a schematic diagram of a transmitting device 102. FIG. 10(i) can also be considered a projection view. FIG. 10(i) shows a case where the number of arrangements in FIG. 10(b) is increased. In this example, a plurality of transmitting units 103 and a plurality of optical elements 106 are arranged in one-to-one correspondence. In FIG. 10(i), in a plane including the X and Y directions, a plurality of optical elements 106 are arranged along the X and Y directions, and a plurality of transmitting units 103 are arranged along the X and Y directions. Here, the plurality of optical elements 106 include optical elements 106 arranged in a region 1002 including a position 1001 that is the center of the oscillation region, and optical elements 106 arranged in a region 1003 that is arranged from the position 1001 to the outer edge of the oscillation region. Here, the optical elements 1006 arranged in the region 1003 have a different lens power than the optical elements 1006 arranged in the region 1002. For example, the power of the optical element 1006 arranged in region 1003 is set stronger or weaker than the power of the optical element 1006 arranged in region 1002. This configuration facilitates uniforming the intensity distribution of terahertz waves from the plurality of transmitters 103 arranged in an array. Note that the number of optical elements 106 and the number of transmitters 103 in this example may be different. That is, the optical unit 105 has a plurality of optical elements 106 arranged in an array, and among the plurality of optical elements 106, the optical elements 106 arranged on the outer edge of the array have different powers from the optical elements 106 arranged inside the array. The power of the optical elements can be set appropriately in consideration of the output distribution of the plurality of transmitters 103. The power of the optical elements can be changed by appropriately setting the shape, material, curvature, etc. of the optical elements.

[0070] 10(i), instead of differentiating the powers of the multiple optical elements 106, the arrangement intervals of the multiple optical elements 106 can be different between the region 1002 and the region 1003. This configuration can also make the output distribution of the multiple transmitting sections 103 uniform. In this case, the arrangement intervals of the multiple transmitting sections 103 may be different from or may match the arrangement intervals of the multiple optical elements 106. This configuration may also be combined with a configuration in which the powers of the multiple optical elements 106 are different. These configurations can be selected as appropriate.

[0071] The following describes modified examples shown in FIGS. 11(a) and 11(b). FIG. 11(a) is a schematic diagram showing a cross section of an emitting device 102. In FIG. 11(a), multiple emitting units 103 are arranged for one optical element 106. FIG. 11(b) is a schematic diagram of the emitting device 102 corresponding to FIG. 11(a). FIG. 11(b) shows a configuration in which a groove structure is provided in the optical element 106 of FIG. 11(a). FIG. 11(c) is a schematic diagram showing a cross section of the oscillator 102. FIG. 11(d) is a schematic diagram showing the top surface of the oscillator 102, which can also be considered a projection view. This modified example differs from the examples of FIGS. 10(c) and 10(d) in the number of emitting units 103 for one optical element 106. The optical unit 105 has multiple optical elements 106, and the number of multiple emitting units 103 is greater than the number of multiple optical elements 106. For example, the optical element 106 is a cylindrical lens or the like, and three transmitters 103 are provided for one optical element 106. With this configuration, the intensity distribution of the terahertz waves from the multiple transmitters 103 can be made uniform. FIG. 11(e) is a modification of FIG. 11(d). While FIG. 11(d) has three optical elements 106, FIG. 11(e) has one optical element 106. As described above, suitable characteristics can be obtained by setting the number of optical elements and transmitters.

[0072] (Embodiment 6) The measurement system according to this embodiment will be described with reference to Fig. 12. Fig. 12 is a schematic diagram for explaining the configuration of the measurement system. Here, the subject of the measurement system may be, for example, a photosensitive drum coated with an amorphous silicon layer, a painted structure, such as a bridge, or the like.

[0073] The measurement system includes a measurement system 1201, a transmitter 1202, and a support unit 1205. The measurement system 1201 is, for example, a terahertz wave camera capable of detecting terahertz waves. The transmitter 1202 includes, for example, a plurality of transmitters 1203 that emit terahertz waves and an optical unit 1204 arranged corresponding to the transmitters 1203. The support unit 1205 is, for example, a stage, and supports an object 1206. The support unit 1205 may include a moving unit for moving the object 1206. For example, the object 1206 includes a substrate 1207 and a coating layer 1208. The transmitter 1202 of the measurement system 1201 is controlled by a control unit 1211 and can emit terahertz waves having a specific irradiation pattern 1209. The measurement system 1201 detects terahertz waves 1210 reflected by the object 1206.

[0074] The measurement system may further include a pattern determination unit 1220, a distribution measurement unit 1221, a control unit 1222, a memory unit 1223, a monitoring unit 1224, an image synthesis unit 1225, a memory unit 1226, and an inspection unit 1227. The monitoring unit 1224 monitors the posture, such as the position and direction, of the object 1206 corresponding to the state of the support unit 1205. For example, the monitoring unit 1224 is a position detection device such as a visible camera or radar, and outputs posture information of the object 1206 in the measurement area detected by the measurement system 1201. The control unit 1222 controls the state of the support unit 1205. The control unit 1222 then references the posture information of the object 1206 output by the monitoring unit 1224 and outputs coordinate information of the measurement area of ​​the object 1206. The control unit 1222 may control the state of the support unit 1205 in accordance with the posture information of the monitoring unit 1224. The pattern determination unit 1220 references the image data output from the measurement system 1201 and extracts the position and area of ​​the irradiation pattern 1209 emitted from the transmitter 1202, which are included in the image data. The distribution measurement unit 1221 outputs the intensity distribution of pixels corresponding to the irradiation pattern 1209 extracted by the pattern determination unit 1220. At this time, image processing is performed to suppress the light source unevenness described above, and an intensity distribution image derived from the physical properties and shape of the object 1206 in the measurement area is output. For example, in this embodiment, the intensity distribution image derived from the physical properties and shape of the object 1206 is an image related to the film thickness distribution of the coating layer 1208 and the surface shape and scratches of the base material 1207 below the coating layer 1208. The intensity distribution image is not limited to this. The image synthesis unit 1225 references the coordinate information of the measurement area and the intensity distribution image derived from the physical properties and shape of the object 1206, and synthesizes a wide-range intensity distribution image that follows the shape of the object 1206. At this time, the intensity distribution image may be synthesized by referring to spatial coordinate information relating to the shape of the object 1206 stored in the memory unit 1223. The memory unit 1223 can also be called an object shape information memory unit. The inspection unit 1227 inspects the shape and physical properties of the object 1206 by referring to a wide range of intensity distribution images. For example, the inspection unit 1227 judges whether the shape and physical properties are good or bad by referring to reference information on the shape and physical properties of the object 1206 stored in the memory unit 1226. The memory unit 1226 can also be called a reference data memory unit.The film thickness of the coating layer 1208 can also be measured by using information from the surface of the substrate 1207 and information from the surface of the coating layer 1208. In this case, the film thickness can be output by performing calculations in the image synthesis unit 1225, for example, based on the output from the measurement system 1201. The measurement system can also observe the surface of the substrate 1207 of the subject 1206.

[0075] The measurement system may have a support unit for the transmitting device 1202 and the measurement system 1201, and may also have a moving unit for at least one of them. That is, by moving at least one of the object 1206, the transmitting device 1202, and the measurement system 1201, the measurement position of the object 1206 can be changed.

[0076] The measurement system shown in this embodiment makes it possible to safely observe the substrate 1207 covered with the coating layer 1208. In addition, since the posture of the object is referenced and an intensity distribution image is synthesized along the shape of the object for inspection, it is easily applicable to objects with free-form surfaces.

[0077] (Embodiment 7) The measurement system according to this embodiment will be described with reference to Fig. 13. Fig. 13 is a schematic diagram for explaining the configuration of a camera system 1300 using terahertz waves.

[0078] Camera system 1300 includes a transmitting device 1301, a detecting device 1302, and a processing unit 1303. Terahertz waves emitted from transmitting device 1301 are reflected by a subject 1305 and detected by detecting device 1302. Processing unit 1303 processes the signal detected by detecting device 1302. Image data generated by processing unit 1303 is output from output unit 1304. With this configuration, a terahertz image can be acquired.

[0079] The optical unit 105 in each embodiment can have any configuration, such as a Fresnel lens, a cylindrical lens, an elliptical lens, a convex lens, a concave lens, or a biconvex lens. The optical unit 105 may also be an optical element such as a prism. The optical unit 105 may be made up of multiple layers containing at least one material that is transparent to terahertz waves, such as polyethylene, Teflon, high-resistivity silicon, or polyolefin resin. Although the optical unit 105 has been shown as having a configuration in which multiple optical elements 106 are integrated into one unit, it may also have independent optical elements 106.

[0080] (Other embodiments) The optical unit 105 in each embodiment may have an anti-reflection film or anti-reflection structure on at least one of its upper and lower outer edges to reduce reflection of terahertz waves. The upper outer edge can also be called the outer edge on the output side, and the lower outer edge can also be called the outer edge on the input side.

[0081] The image processing in each embodiment may be performed by AI processing (artificial intelligence processing). Also, the image processing in each embodiment can be modified as appropriate, such as performing part of the AI ​​processing in a processing circuit or the like and performing the remaining processing in the cloud.

[0082] In the second embodiment, the operation of the transmitting device 102 may be controlled according to the measured intensity distribution result. The operating conditions, such as the power of each transmitting unit 103 or each oscillation element 127, may be controlled individually so that the intensity distribution becomes a desired distribution.

[0083] The camera systems described in the respective embodiments are merely examples, and other configurations may be used. In particular, the information acquired by the system is not limited to image information, and may be a detection system that detects signals.

[0084] The embodiments are merely examples of specific implementations of the present invention, and should not be construed as limiting the technical scope of the present invention. In other words, the present invention can be implemented in various forms without departing from its technical concept or main features. [Explanation of symbols]

[0085] 101 Detection device 102 Transmitting Device 103 Transmission Department 104 Components 105 Optics Department 106 Optical Elements 111 Subject

Claims

1. a plurality of transmitting units each including a plurality of oscillation elements that oscillate terahertz waves and coupling wires that connect the plurality of oscillation elements; an optical unit provided on the plurality of transmitting units and having a plurality of optical elements; a support portion that supports the optical portion; a first member on which the support portion is disposed, each of the plurality of transmitting units has a surface on the optical unit side that includes an oscillation region in which the plurality of oscillation elements are arranged; The distance between the surface and the optical unit is 2D, where λ is the wavelength of the terahertz wave and D is the length of the oscillation region. ２ / λ or more.

2. 2. The transmitting device according to claim 1, wherein a space is provided between the plurality of transmitting units and the optical unit.

3. The transmitting device according to claim 1 , wherein the number of the plurality of transmitting units is greater than the number of the plurality of optical elements.

4. The transmitting device according to claim 1 , wherein the number of the plurality of transmitting units is smaller than the number of the plurality of optical elements.

5. the plurality of optical elements include a first optical element, a second optical element, and a third optical element arranged in this order along a first direction; the plurality of transmitting units include a first transmitting unit and a second transmitting unit arranged in this order along the first direction, 5. The transmitting device of claim 4, wherein the first optical element is positioned above the first transmitting portion, the third optical element is positioned above the second transmitting portion, and the second optical element is positioned above the area between the first transmitting portion and the second transmitting portion.

6. The transmitting device according to claim 1 , wherein the number of the plurality of transmitting units is equal to the number of the plurality of optical elements.

7. The plurality of optical elements are arranged in an array, 7. The transmitting device according to claim 1, wherein, of the plurality of optical elements, optical elements arranged on the outer edge of the array and optical elements arranged inside the array have different powers.

8. Each of the plurality of transmitters has a second member, 8. The transmitting device according to claim 1, wherein the second member includes a third member on which the plurality of oscillation elements are arranged, and a fourth member on which a circuit for operating the plurality of oscillation elements is arranged.

9. The plurality of transmitters are arranged along a first direction, The transmitting device according to claim 1 , wherein the plurality of optical elements are arranged along the first direction.

10. A plurality of transmitters, each having a plurality of oscillation elements that oscillate terahertz waves and coupling wires that connect the plurality of oscillation elements; an optical unit provided on the plurality of transmitting units and having a plurality of optical elements; the number of the plurality of transmitting units is equal to the number of the plurality of optical elements, each of the plurality of transmitting units has a surface on the optical unit side that includes an oscillation region in which the plurality of oscillation elements are arranged; The transmitting device, wherein the distance between the surface and the optical unit is 2D 2 / λ or more, where λ is the wavelength of the terahertz wave and D is the length of the oscillation region.

11. 11. The transmitting device according to claim 1, wherein the optical unit is at least one of a Fresnel lens, a cylindrical lens, an elliptical lens, a convex lens, and a concave lens.

12. 12. The transmitting device according to claim 1, wherein the optical section includes at least one of polyethylene, high-resistivity silicon, Teflon, and polyolefin.

13. the optical portion has a concave-convex structure on the surface, The transmitting device according to claim 1 , wherein the height and width of the concave-convex structure are 1 / 30λ or more and 1 / 10λ or less, where λ is the wavelength of the terahertz wave.

14. A transmitting device according to any one of claims 1 to 13; a detection device for detecting the terahertz waves emitted from the transmission device; and a support portion for supporting a subject, A measurement system having at least one of a first moving unit for moving the object and a second moving unit for moving the transmitter.

15. the subject has a first portion and a second portion covering the first portion; The measurement system according to claim 14 , further comprising a processing unit that outputs the film thickness of the second portion based on an output from the detection device.

16. A transmitting device according to any one of claims 1 to 15; a detection device for detecting the terahertz waves emitted from the transmission device; and a processing unit that processes signals from the detection device.

Images