Light projecting and receiving device, and distance measuring system

Abstract

To provide a light projecting and receiving device that can expand a measurable range and is robust to external light.SOLUTION: A light projecting and receiving device according to an aspect of the present disclosure comprises: a first light emitting unit that emits first light and second light in quantum entanglement with each other; a second light emitting unit that emits third light being classic light; and a light receiving unit. At least one of the first light and the second light is reflected on an object to be first reflected light. The third light is reflected on the object to be second reflected light. The light receiving unit receives the first reflected light and the second reflected light.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a light projecting and receiving device and a distance measuring system. [Background technology]

[0002] Distance measuring systems such as LiDAR (Light Detection and Ranging) are known that project pulsed light emitted from a laser light source, receive light reflected by an object of the projected light, and measure the distance to the object based on the time difference between projecting the pulsed light and receiving the reflected light.

[0003] Furthermore, a light projection and reception technology has been disclosed in which, for a pair of frequency-entangled photons, a first photon is transmitted along a first optical path and a second photon is transmitted along a second optical path, and the photon transmitted along the first optical path is detected by a first detector, and the photon transmitted along the second optical path is detected by a second detector (see, for example, Patent Document 1). Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the light projection and reception technology described in Patent Document 1 is applied to a measurement system such as a distance measuring system, the measurable range may become narrow.

[0005] An object of the present disclosure is to provide a light projecting and receiving device and a distance measuring system that can widen the measurable range and is resistant to external light. [Means for solving the problem]

[0006] A light-emitting / receiving device according to one embodiment of the present disclosure includes a first light-emitting unit that emits first light and second light that are in a quantum entangled state with each other, a second light-emitting unit that emits third light that is classical light, and a light-receiving unit, wherein at least one of the first light and the second light is reflected by an object to become a first reflected light, and the third light is reflected by the object to become a second reflected light, and the light-receiving unit receives the first reflected light and the second reflected light.

[0007] A ranging system according to one embodiment of the present disclosure includes an analysis unit that receives first information including time-of-flight information of a first reflected light generated when at least one of a first light and a second light in a quantum entangled state is reflected by an object, and second information including time-of-flight information of a second reflected light generated when a third light, which is classical light, is reflected by the object, and the analysis unit outputs at least one of first distance information based on the first information and second distance information based on the second information. Effect of the Invention

[0008] According to the present disclosure, it is possible to provide a light projecting and receiving device and a distance measuring system that can widen the measurable range and are resistant to external light. [Brief description of the drawings]

[0009] [Figure 1] 1 is a block diagram showing a configuration of a light emitting and receiving device according to a first embodiment. [Diagram 2] 3 is a block diagram showing the functional configuration of a control unit according to the first embodiment. FIG. [Diagram 3] FIG. 4 is a block diagram showing a configuration of a light projecting and receiving device according to a modified example of the first embodiment. [Figure 4] FIG. 11 is a block diagram showing the configuration of a distance measuring system according to a second embodiment. [Diagram 5] FIG. 11 is a block diagram showing a hardware configuration of an analysis unit according to the second embodiment. [Figure 6] FIG. 11 is a block diagram showing the functional configuration of an analysis unit according to the second embodiment. [Figure 7] FIG. 11 is a flowchart showing a process performed by an analysis unit according to the second embodiment. [Figure 8] FIG. 13 is a block diagram showing a configuration of a distance measuring system according to a modified example of the second embodiment. [Figure 9] FIG. 13 is a block diagram showing the configuration of a distance measuring system according to a third embodiment. [Figure 10] FIG. 13 is a block diagram showing the configuration of a distance measuring system according to a modified example of the third embodiment. [Figure 11] FIG. 13 is a block diagram showing the configuration of a distance measuring system according to a fourth embodiment. [Figure 12] FIG. 13 is a block diagram showing the functional configuration of an analysis unit according to the fourth embodiment. [Figure 13] FIG. 13 is a flowchart showing a process performed by an analysis unit according to the fourth embodiment. [Figure 14] FIG. 13 is a block diagram showing the configuration of a distance measuring system according to a fifth embodiment. [Figure 15] FIG. 13 is a block diagram showing the functional configuration of an analysis unit according to the fifth embodiment. [Figure 16] FIG. 13 is a block diagram showing the functional configuration of a control unit according to the fifth embodiment. [Figure 17] FIG. 13 is a flowchart showing the operation of the distance measuring system according to the fifth embodiment. [Figure 18] FIG. 13 is a flowchart showing the operation of a distance measuring system according to a modified example of the fifth embodiment. [Figure 19] FIG. 13 is a block diagram showing the configuration of a distance measuring system according to a sixth embodiment. [Figure 20] FIG. 13 is a block diagram showing the functional configuration of an analysis unit according to the sixth embodiment. [Figure 21] FIG. 13 is a flowchart showing the operation of the distance measuring system according to the sixth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. In this specification and the drawings, components having substantially the same functional configurations are denoted by the same reference numerals, and redundant description will be omitted as appropriate.

[0011] The light projecting and receiving device according to the embodiment is mounted on a measurement system such as a distance measuring system, projects light used in measurement, and receives light reflected by an object to be measured. A distance measuring system according to the embodiment includes the light projecting and receiving device according to the embodiment, projects pulsed light from the light projecting and receiving device, receives the reflected light of the pulsed light by the object, and measures the distance to the object based on the time difference between projecting the pulsed light and receiving the reflected light.

[0012] [First embodiment] <Configuration of the light emitting and receiving device according to the first embodiment> The configuration of the light projecting and receiving device according to the first embodiment will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a block diagram showing an example of the configuration of the light projecting and receiving device 100 according to the first embodiment. Fig. 2 is a block diagram showing an example of the functional configuration of a control unit 300 included in the light projecting and receiving device 100.

[0013] As shown in FIG. 1, the light emitting / receiving device 100 includes a light emitting section 200, a control section 300, and a light receiving section 400. The light emitting / receiving device 100 includes a light emitting section 200, a control section 300, and a light receiving section 400.

[0014] The light-emitting unit 200 includes a first light-emitting unit 201 that emits a first light L1 and a second light L2 that are in a quantum entangled state with each other. The light-emitting unit 200 generates, for example, a quantum entangled photon pair including the first light L1 and the second light L2. The quantum entangled photon pair is composed of a signal light and an idler light, and the signal light and the idler light are in a quantum entangled state with each other. Here, the first light L1 corresponds to the signal light, and the second light L2 corresponds to the idler light.

[0015] The light emitting unit 200 may employ, for example, spontaneous parametric down-conversion (SPDC). The light emitting unit 200 includes a laser light source 21 and a nonlinear optical crystal 22. The laser light source 21 is, for example, a semiconductor laser, and emits pumping light L0 toward the nonlinear optical crystal 22. The nonlinear optical crystal 22 is a type I nonlinear optical crystal, and emits first light L1 and second light L2 coaxial with the pumping light. The first light L1 and second light L2 have the same wavelength. The pumping light L0, the first light L1, and the second light L2 are each pulsed light. The laser light source 21 does not need to be a semiconductor laser, and may be a solid-state laser.

[0016] The nonlinear optical crystal 22 may be a type II nonlinear optical crystal that emits a first light L1 and a second light L2 that are not coaxial with the pump light L0. The first light L1 and the second light L2 may have different wavelengths. In this case, the first light L1 and the second light L2 are in a non-degenerate state and have wavelengths different from those in a degenerate state. For example, the first light L1 may be visible light, and the second light L2 may be infrared light.

[0017] In any of the examples of the light emitting section 200, the law of conservation of energy and the phase matching condition expressed by the following (Equation 1) and (Equation 2) using the Dirac constant are satisfied.

[0018]

number

[0019] Here, ω p , ω s , ω i are the angular frequencies of the pump light, signal light, and idler light, respectively, and k p , k s , k iThe vectors are the wave vectors of the pump light, the signal light, and the idler light, respectively. For example, by using pump light with a wavelength of 355 nm, it is possible to generate a quantum entangled photon pair of degenerate signal light and idler light with a wavelength of 710 nm. It is also possible to generate signal light and idler light with different wavelengths while satisfying the law of energy conservation and the phase matching condition. As an example, it is possible to generate signal light with a wavelength of 1000 nm and idler light with a wavelength of 667 nm from pump light with a wavelength of 400 nm.

[0020] It should be noted that the light emitting unit 200 does not need to include the nonlinear optical crystal 22, and may instead include a semiconductor element capable of generating quantum entangled photon pairs. Examples of the semiconductor element capable of generating quantum entangled photon pairs include a semiconductor element having a quantum dot and a semiconductor element having a waveguide structure.

[0021] The control unit 300 controls the light emitting and receiving device 100, such as by controlling the on / off of the light emitting unit 200 and the light receiving unit 400. A control instruction to the control unit 300 may be given based on an operation input to the light emitting and receiving device 100, or may be given by transmitting a signal from an external device to the control unit 300 based on an operation input to the external device. The external device here is a personal computer or the like connected to the light emitting and receiving device 100 by wire or wirelessly. The control unit 300 is constituted by an electric circuit, a processor, or the like.

[0022] 2, the control unit 300 includes a light emission control unit 31 and an input / output unit 32. The functions of the light emission control unit 31 and the input / output unit 32 are realized by an electric circuit, a processor, or the like.

[0023] The light emission control unit 31 gives the laser light source 21 the timing to emit the excitation light L0 to the nonlinear optical crystal 22, thereby giving the light emission unit 200 the timing of light projection. The light emission control unit 31 also gives the light emission unit 200 information such as the number of repetitions of light projection together with the timing of light projection. The light emission unit 200 projects the first light L1 and the second light L2 onto the object S based on the information indicated by the light emission control unit 31.

[0024] The input / output unit 32 controls communication with a controlled object such as the light-emitting unit 200, thereby enabling transmission and reception of various information with the controlled object.

[0025] 1, the light receiving unit 400 includes a first light receiving unit 401. The first light receiving unit 401 may be, for example, a high-sensitivity image sensor including a SPAD (Single Photon Avalanche Diode) as a quantum entanglement light receiving unit. The light receiving unit 400 may include an area sensor in which pixels are two-dimensionally arranged, or may include a line sensor in which pixels are one-dimensionally arranged.

[0026] At least one of the first light L1 and the second light L2 emitted from the light emitting unit 200 is reflected by the object S to become a first reflected light R1. The reflection by the object S includes specular reflection by the object S, diffuse reflection by the object S, scattering by the object S, and the like. The first light receiving unit 401 acquires multiple frames obtained by receiving the first reflected light R1 at a single photon level in a time series, and outputs a first received light image Im1 captured from the multiple frames. The analysis unit or the like that receives the first received light image Im1 from the light receiving unit 400 can acquire measurement information such as distance information by calculation based on the first received light image Im1.

[0027] Not only quantum entangled photon pairs, but also classical light that is not in a quantum entangled state and ambient light that is not used for distance measurement may be incident on the light receiving unit 400. In order to detect quantum entangled photon pairs from among these photons, coincidence measurement can be used. Coincidence measurement is a method of counting as detection of a quantum entangled photon pair only when an event in which a photon is detected by the first detection unit coincides with an event in which a photon is detected by the second detection unit. For example, when the first light L1 and the second light L2 follow approximately the same optical path, it is considered that the first light L1 and the second light L2 are incident on the first light receiving unit 401 approximately at the same time. The analysis unit, etc. can obtain quantum correlation information by processing the first received light image Im1 output from the first light receiving unit 401. The quantum correlation information refers to information regarding a correlation that may occur due to the existence of a quantum entangled state. The analysis unit, etc. can obtain, for example, an image including quantum correlation information as the quantum correlation information.

[0028] The light projecting and receiving device 100 may further include an irradiation unit including optical elements such as a lens, a diffractive optical element, and a diffusion plate, and a scanning mirror. The irradiation unit irradiates divergent light generated by a lens or the like from the light projecting and receiving device 100 to the object S. When the irradiation unit includes a lens that diverges the first light L1 and the second light L2, the surrounding space can be illuminated at once by a collective illumination method. The irradiation unit can also include an optical scanning mechanism including a scanning mirror or the like. Each of the first light L1 and the second light L2 emitted from the light emitting unit 200 is scanned by a scanning mirror that is rotatable around a rotation axis and is irradiated to the object S. When the irradiation unit includes an optical scanning mechanism, the partial irradiation location can be mechanically moved by a scanning illumination method that scans the light projected at a narrow angle.

[0029] The light projecting and receiving device 100 may further include a light receiving and guiding section that includes an optical element such as a lens or a diffractive optical element, a scanning mirror, and the like, and guides the first reflected light R1 to the first light receiving section 401.

[0030] <Main Effects of the Light Emitter / Receiver Device 100> As described above, in this embodiment, the light projecting and receiving device 100 projects photon pairs including the first light L1 and the second light L2 in a quantum entangled state with each other, and outputs the first received light image Im1 obtained by receiving the first reflected light R1 of the projected photon pairs by the object S. By having an analysis unit or the like acquire measurement information such as distance information based on the first received light image Im1, it is possible to realize measurement that is highly robust against disturbance light.

[0031] <Modification of the first embodiment> Next, a modified example of the first embodiment will be described. Note that the same names and symbols as those in the already described embodiments indicate the same or similar members or components, and detailed descriptions will be omitted as appropriate. This also applies to the modified examples and embodiments described below.

[0032] In this modified example, the first light L1 is emitted to the outside, and the second light L2 is emitted to an optical path that is guided to the light receiving unit 400, and the main difference from the first embodiment is that of the first light L1 and the second light L2, only the first light L1 is reflected by the object S to become the first reflected light R1.

[0033] Fig. 3 is a block diagram showing an example of the configuration of a light projecting and receiving device 100a according to a modified example of the first embodiment. As shown in Fig. 3, in the light projecting and receiving device 100a, of the first light L1 and the second light L2 emitted from the first light emitting unit 201, only the first light L1 is projected to the outside, and the second light L2 is guided to the first light receiving unit 401 without passing through the outside, and is received by the first light receiving unit 401. Note that the first light receiving unit 401 may include a first detector that receives the first light L1 and a second detector that receives the second light L2.

[0034] In this modification, the timing of receiving the first light L1 and the second light L2 by the first light receiving unit 401 is different because the optical paths of the first light L1 and the second light L2 are different. In this modification, quantum correlation information can be obtained based on the first light L1 and the second light L2 even in this case. In this modification, robustness against external light can be increased by using the second light L2 that does not pass through the object S. Note that the second light L2 may be projected to the outside, and the first light L1 may be guided to the first light receiving unit 401 without passing through the outside. Other effects and advantages are almost the same as those of the first embodiment.

[0035] [Second embodiment] Next, a distance measuring system according to the second embodiment will be described. The distance measuring system according to this embodiment differs from the first embodiment mainly in that, in addition to the light projecting and receiving device according to the embodiment, the system includes an analysis unit that acquires distance information to an object by calculation based on a first received light image output from the light projecting and receiving device. The light projecting and receiving device included in the distance measuring system according to the second embodiment mainly differs from the light projecting and receiving device according to the first embodiment in that the light projecting and receiving device includes a second light emitting unit that emits a third light, which is classical light, and the third light is reflected by the object S to become a second reflected light, and the light receiving unit receives the first reflected light and the second reflected light.

[0036] <Configuration example of distance measuring system according to the second embodiment> Fig. 4 is a block diagram showing an example of the configuration of a distance measuring system according to the second embodiment. As shown in Fig. 4, the distance measuring system 1000 according to the second embodiment includes a light projecting and receiving device 100b and an analysis unit 500. The light projecting and receiving device 100b also includes a light emitting unit 200b, a control unit 300, and a light receiving unit 400b. The light emitting unit 200b further includes a second light emitting unit 202 in addition to a first light emitting unit 201.

[0037] The second light-emitting unit 202 emits a third light L3, which is classical light. The second light-emitting unit 202 includes a laser light source 21, a beam splitter 23, and a reflecting mirror 24. The laser light source 21 is shared by the first light-emitting unit 201 and the second light-emitting unit 202. The beam splitter 23 reflects a part of the light emitted from the laser light source 21 and transmits the rest. The light transmitted through the beam splitter 23 is incident on the nonlinear optical crystal 22 as excitation light L0. On the other hand, the light reflected by the beam splitter 23 is reflected by the reflecting mirror 24 and then projected to the outside as the third light L3. The third light L3 projected to the outside is reflected by the object S to become the second reflected light R2.

[0038] The light receiving unit 400b further includes a second light receiving unit 402 that receives light including the second reflected light R2 in addition to the first light receiving unit 401. The first light receiving unit 401 may include a single photon detector that detects a single photon, and the second light receiving unit 402 may include a light amount detector that detects the amount of received light by accumulating for a predetermined period or a predetermined number of times. The light amount detector may be a photo diode (PD), an avalanche photo diode (APD), a SPAD, an electron multiplying (EM)-charge coupled device (CCD), or the like. An EM-CCD is a CCD with an electron multiplication function. When a single photon level detector such as a SPAD is used as the light amount detector, a light intensity image is generated by accumulating a received light image.

[0039] The first light receiving unit Im1 outputs the first received light image Im1 to the analysis unit 500. The second light receiving unit Im2 outputs the second received light image Im2 to the analysis unit 500. The light receiving unit 400b includes the first light receiving unit 401 and the second light receiving unit 402, and thus can acquire, in parallel, the first received light image Im1 derived from light in a quantum entangled state and the second received light image Im2 derived from classical light.

[0040] The analysis unit 500 receives the first received light image Im1 from the first light receiving unit 401, and also receives the second received light image Im2 from the second light receiving unit 402. The analysis unit 500 outputs distance information D2 including at least one of first distance information based on the first received light image Im1 and second distance information based on the second received light image Im2.

[0041] <Example of hardware configuration of analysis unit 500> Fig. 5 is a block diagram showing an example of a hardware configuration of the analysis unit 500. As shown in Fig. 5, the analysis unit 500 includes a CPU (Central Processing Unit) 501, a ROM (Read Only Memory) 502, and a RAM (Random Access Memory) 503. The analysis unit 500 also includes an HDD / SSD (Hard Disk Drive / Solid State Drive) 504, and a communication I / F (Interface) 505. These are connected to each other via a system bus A so as to be able to communicate with each other.

[0042] The CPU 501 executes control processing including various types of arithmetic processing. The ROM 502 stores programs used to drive the CPU 501, such as an IPL (Initial Program Loader). The RAM 503 is used as a work area for the CPU 501. The HDD / SSD 504 stores various types of information, such as programs and data.

[0043] The communication I / F 505 is an interface for the analysis unit 500 to communicate with various external devices in a wired or wireless manner. The external devices here are the light-emitting unit 200b, the light-receiving unit 400b, etc. The analysis unit 500 can transmit signals to the light-emitting unit 200b, the light-receiving unit 400b, etc., and receive signals and data from the light-emitting unit 200b, the light-receiving unit 400b, etc., via the communication I / F 505. The communication I / F 505 can also communicate with an external device via a communication network, etc. For example, the analysis unit 500 can connect to the Internet via the communication I / F 505 and communicate with an external device via the Internet.

[0044] <Example of functional configuration of analysis unit 500> 6 is a block diagram showing an example of a functional configuration of the analysis unit 500. The analysis unit 500 includes an input unit 51, a first distance calculation unit 52, a second distance calculation unit 53, a selection unit 54, and an output unit 55. The functions of the input unit 51 and the output unit 55 are realized by a communication I / F 505 or the like. The functions of the first distance calculation unit 52, the second distance calculation unit 53, and the selection unit 54 are realized by a processor such as a CPU 501 executing a process defined in a program stored in a non-volatile memory such as a ROM 502, or the like.

[0045] Each function of the analysis unit 500 may be realized by one or more processing circuits. The processing circuit here includes a processor such as the CPU 501, as well as devices such as an application specific integrated circuit (ASIC), a digital signal processor (DSP), a field programmable gate array (FPGA), and a conventional circuit module designed to execute each of the above functions. Some of the functions of the analysis unit 500 may be realized by distributed processing between the analysis unit 500 and an external device.

[0046] The input unit 51 receives a first received light image Im1 from the first light receiving unit 401 by controlling communication with the first light receiving unit 401, and receives a second received light image Im2 from the second light receiving unit 402 by controlling communication with the second light receiving unit 402. The input unit 51 outputs the first received light image Im1 to the first distance calculation unit 52, the second received light image Im2 to the second distance calculation unit 53, and the second received light image Im2 to the selection unit 54.

[0047] The first distance calculation unit 52 calculates first distance information Ds1 to the object S based on the first received light image Im1 received via the input unit 51, and outputs the calculated first distance information Ds1 to the selection unit 54. For example, the first distance calculation unit 52 can identify an object frame from multiple frames capturing the first received light image Im1, and calculate the first distance information Ds1 to the object S based on the flight time of light obtained from the identified object frame. The object frame refers to a frame in which reflected light from the object S is received, in other words, a frame in which the object S is detected.

[0048] In order to identify the object frame, the first distance calculation unit 52 can use, for example, a JPD (Joint Probability Distribution) algorithm based on a joint probability distribution. The JPD algorithm is a calculation method that uses the correlation between multiple pixels in the same frame and the correlation between multiple pixels between adjacent frames in the time direction based on multiple frames obtained in a time series to produce quantum correlation information. For details of the JPD algorithm, see, for example, "Hugo Defienne et al., "PHYSICAL REVIEW A 103, 042608 (2021)", March 17, 2021, available on the Internet. <URL:https: / / arxiv.org / pdf / 2106.10689.pdfhttps: / / www.physics.gla.ac.uk / xtremelight / publications / PRA-SPADs-Hugo%282021%29.pdf> " or "Han Liu et al., "Enhancing LIDAR performance metrics using continuous-wave photon-pair sources", 14, Apr. 2020, Internet<https: / / arxiv.org / pdf / 2004.06754.pdf> However, the method of calculating the first distance information Ds1 based on the first received-light image Im1 is not limited to using the JPD algorithm, and other calculation methods may be used.

[0049] The second distance calculation unit 53 calculates second distance information Ds2 to the object S based on the second received light image Im2 received via the input unit 51, and outputs the calculated second distance information Ds2 to the selection unit 54. The second distance calculation unit 53 can calculate the second distance information Ds2 by a Time Of Flight (TOF) method based on the time difference between when the third light L3 is projected and when the first reflected light R2 is received.

[0050] The selection unit 54 selects at least one of the first distance information Ds1 and the second distance information Ds2 based on the amount of received light in the second received light image Im2, and outputs the selection result as distance information Ds to the output unit 55. For example, the selection unit 54 selects the first distance information Ds1 when the amount of received light is a first value, and selects the second distance information Ds2 when the amount of received light is a second value greater than the first value. Information such as the average value of luminance of at least some of the pixels in the second received light image Im2, or the maximum or minimum value of pixels in at least some of the pixels can be used as the information on the amount of received light.

[0051] The first value, which is the threshold value of the amount of received light, can be determined in advance by experiment, simulation, etc. For example, a distance at which a distance measurement accuracy equal to or higher than a desired distance measurement accuracy can be determined using a first received light image Im1 using light in a quantum entangled state, and the amount of received light of a second received light image Im2 at this distance can be determined as the first value.

[0052] The output unit 55 controls communication with an external device to output the distance information Ds received from the selection unit 54 to the external device. The external device here may be an ECU (Electronic Control Unit) of an automobile that uses the distance measurement result by the distance measurement system 1000.

[0053] <Example of processing by the analysis unit 500> Fig. 7 is a flow diagram showing an example of processing by the analysis unit 500. Fig. 7 shows processing by the analysis unit 500 from receiving the first received light image Im1 and the second received light image Im2 from the light receiving unit 400b via the input unit 51 to outputting distance information Ds.

[0054] First, in step S11, the analysis section 500 causes the first distance calculation section 52 to acquire the first distance information Ds1 by calculation based on the first received-light image Im1.

[0055] Next, in step S12, the analysis section 500 causes the second distance calculation section 53 to acquire second distance information Ds2 by calculation based on the second received-light image Im2.

[0056] The order of steps S11 and S12 may be changed as appropriate, and steps S11 and S12 may be executed in parallel.

[0057] Next, in step S13, the analysis unit 500 acquires information on the amount of received second reflected light R2 by the selection unit 54 based on the second received light image Im2.

[0058] Next, in step S14, the analysis unit 500 determines, by the selection unit 54, whether or not the amount of the second reflected light R2 received is equal to or less than a first value.

[0059] In step S14, if it is determined that the amount of the second reflected light R2 received is equal to or less than the first value (step S14, YES), in step S15, the analysis unit 500 selects the first distance information Ds1 as the distance information Ds using the selection unit 54.

[0060] On the other hand, if it is determined in step S14 that the amount of received light of the second reflected light R2 is not less than the first value, that is, that the amount of received light of the second reflected light R2 is a second value greater than the first value (step S14, NO), in step S16, the analysis unit 500 selects the second distance information Ds2 as the distance information Ds by the selection unit 54.

[0061] Next, in step S17, the analysis unit 500 outputs the distance information Ds via the output unit 55 to an external device.

[0062] In this manner, the analysis section 500 can receive the first received light image Im1 and the second received light image Im2 from the light projecting and receiving device 100b, and output the distance image Ds.

[0063] <Main Effects of the Light Projecting and Receiving Device 100b and the Distance Measuring System 1000> As described above, the light projector / receiver 100b according to this embodiment includes the first light emitter 201 that emits the first light L1 and the second light L2 that are in a quantum entangled state with each other, the second light emitter 202 that emits the third light L3 that is classical light, and the light receiver 400b. At least one of the first light L1 and the second light L2 is reflected by the object S to become the first reflected light R1, and the third light L3 is reflected by the object S to become the second reflected light R2. The light receiver 400b receives the first reflected light R1 and the second reflected light R2.

[0064] The light projecting and receiving device 100b according to this embodiment can realize measurement with high robustness against disturbance light by acquiring measurement information such as distance information based on the first received light image Im1. On the other hand, since each of the first light L1 and the second light L2 is weak light at a single photon level, if the distance from the light projecting and receiving device 100b to the object S is long, the measurement range of the measurable distance may be narrowed due to attenuation during propagation through space. In contrast, the light projecting and receiving device 100b acquires the second distance information Ds2 by the third light L3 in addition to the first distance information Ds1 obtained by the first light L1 and the second light L2. Since the third light L3 has a larger light amount than the first light L1 and the second light L2, the measurement range of the measurable distance can be widened. As described above, in this embodiment, a light projecting and receiving device 100b can be provided that can widen the measurable range and is resistant to external light.

[0065] The distance measuring system 1000 according to this embodiment includes the light projecting and receiving device 100b, and an analysis unit 500 that receives the first received light image Im1 from the first light receiving unit 401 and receives the second received light image Im2 from the second light receiving unit 402. The analysis unit 500 outputs at least one of the first distance information Ds1 based on the first received light image Im1 and the second distance information Ds2 based on the second received light image Im2. The first distance information Ds1 based on the first received light image Im1 uses the first light L1 and the second light L2, and therefore has high robustness against disturbance light. On the other hand, the second distance information Ds2 based on the second received light image Im2 uses the third light L3, and therefore the range in which distance can be measured can be widened. Therefore, in this embodiment, it is possible to provide a distance measuring system 1000 that has a wide range in which distance can be measured and is resistant to external light.

[0066] Furthermore, the analysis unit 500 may output at least one of the first distance information Ds1 and the second distance information Ds2 selected based on the amount of received light in the second received light image Im2. For example, the analysis unit 500 may output the first distance information Ds1 when the amount of received light is a first value, and output the second distance information Ds2 when the amount of received light is a second value greater than the first value. With this, even if the desired distance measurement accuracy cannot be obtained by using the first distance information Ds1 as the distance information Ds when the distance to the object to be measured is long, the desired distance measurement accuracy can be ensured by using the second distance information Ds2 as the distance information Ds.

[0067] From another perspective, the first received light image Im1 corresponds to first information including time-of-flight information of the first reflected light R1 generated when at least one of the first light L1 and the second light L2, which are in a quantum entangled state with each other, is reflected by the object S. The second received light image Im2 corresponds to second information including time-of-flight information of the second reflected light R2 generated when the third light L3, which is classical light, is reflected by the object S. The analysis unit 500 may output at least one of the first distance information Ds1 based on the first information and the second distance information Ds2 based on the second information. The analysis unit 500 may output at least one of the first distance information Ds1 and the second distance information Ds2 selected based on the second information. The second information includes information regarding the amount of the second reflected light R2 received by the light receiving unit 400b, and the analysis unit 500 may output first distance information Ds1 when the amount of received light is a first value, and output second distance information Ds2 when the amount of received light is a second value greater than the first value.

[0068] <Modification of the second embodiment> Next, a distance measuring system according to a modification of the second embodiment will be described. This modification is mainly different from the second embodiment in that the first light L1, the second light L2, and the third light L3 are extracted from the nonlinear optical crystal 22 in the light emitting section.

[0069] 8 is a block diagram showing an example of the configuration of a distance measuring system 1000c according to a modification of the second embodiment. The distance measuring system 1000c includes a light projecting and receiving device 100c. The light projecting and receiving device 100c includes a light emitting unit 200c.

[0070] The light emitting unit 200c makes the excitation light L0 from the laser light source 21 incident on the nonlinear optical crystal 22, and extracts the third light L3, which is classical light, together with the first light L1 and the second light L2 from the nonlinear optical crystal 22. For example, the light emitting unit 200c can extract the light that is the excitation light L0 transmitted through the nonlinear optical crystal 22 as the third light L3.

[0071] In this modification, the third light L3 is extracted without disposing the beam splitter 23 and the reflecting mirror 24 (see FIG. 4) in the second embodiment, so that the size of the light-emitting unit 200c can be reduced and alignment adjustment of the light-emitting unit 200c can be simplified.

[0072] [Third embodiment] Next, a distance measuring system according to a third embodiment will be described. In this embodiment, the first light L1 is emitted to the outside, the second light L2 is emitted to an optical path that is guided to the light receiving unit 400b, and only the first light L1 of the first light L1 and the second light L2 is reflected by the object S to become the first reflected light R1, which is a main difference from the second embodiment.

[0073] <Configuration example of distance measuring system according to the third embodiment> Fig. 9 is a block diagram showing an example of the configuration of a distance measuring system 1000d according to the third embodiment. As shown in Fig. 9, of the first light L1 and the second light L2 emitted from the first light emitting unit 201, only the first light L1 is projected to the outside, and the second light L2 is guided to the first light receiving unit 401 without passing through the outside, and is received by the first light receiving unit 401.

[0074] In this modification, the timing of receiving the first light L1 and the second light L2 by the first light receiving unit 401 is different because the optical paths of the first light L1 and the second light L2 are different. In this modification, quantum correlation information can be obtained based on the first light L1 and the second light L2 even in this case. In this modification, robustness against external light can be increased by using the second light L2 that does not pass through the object S. Note that the second light L2 may be projected to the outside, and the first light L1 may be guided to the first light receiving unit 401 without passing through the outside. Other effects and advantages are almost the same as those of the second embodiment.

[0075] <Modification of the third embodiment> Next, a distance measuring system according to a modification of the third embodiment will be described. This modification is mainly different from the third embodiment in that the first light L1, the second light L2, and the third light L3 are extracted from the nonlinear optical crystal 22 in the light emitting section.

[0076] 10 is a block diagram showing an example of the configuration of a distance measuring system 1000e according to a modification of the third embodiment. The distance measuring system 1000e includes a light projecting and receiving device 100e. The light projecting and receiving device 100e includes a light emitting unit 200c.

[0077] The light emitting unit 200c makes the excitation light L0 from the laser light source 21 incident on the nonlinear optical crystal 22, and extracts the third light L3, which is classical light, together with the first light L1 and the second light L2 from the nonlinear optical crystal 22. For example, the light emitting unit 200c can extract the light that is the excitation light L0 transmitted through the nonlinear optical crystal 22 as the third light L3.

[0078] In this modified example, the third light L3 is extracted without disposing the beam splitter 23 and the reflecting mirror 24 in the third embodiment (see FIG. 9), so that the size of the light-emitting unit 200c can be reduced and alignment adjustment of the light-emitting unit 200c can be simplified.

[0079] [Fourth embodiment] Next, a distance measuring system according to a fourth embodiment will be described. In this embodiment, the distance measuring system according to the fourth embodiment mainly differs from the above-mentioned embodiments and modifications in that the analysis unit includes an inference unit that inputs quantum correlation information acquired by the first light and the second light in a quantum entangled state, performs inference based on the quantum correlation information, and outputs an inference result.

[0080] <Configuration example of distance measuring system according to the fourth embodiment> Fig. 11 is a block diagram showing an example of the configuration of a distance measuring system 1000f according to the fourth embodiment. As shown in Fig. 11, the distance measuring system 1000f includes an analysis unit 500f.

[0081] Fig. 12 is a block diagram showing an example of a functional configuration of the analysis unit 500f. The analysis unit 500f includes an input unit 51f, a calculation unit 56, and an inference unit 57. The function of the input unit 51f is realized by the communication I / F 505 in Fig. 5, etc. Each function of the calculation unit 56 and the inference unit 57 is realized by a processor such as the CPU 501 in Fig. 5 executing a process defined in a program stored in a non-volatile memory such as the ROM 502, etc.

[0082] The input unit 51 receives a first received light image Im1 as a received light image from the first light receiving unit 401 by controlling communication with the first light receiving unit 401, and outputs the received first received light image Im1 to the inference unit 57. The first received light image Im1 is obtained by the first light receiving unit 401 receiving light including a first reflected light R1 generated when at least one of the first light L1 and the second light L2 is reflected by the object S.

[0083] The calculation unit 56 calculates quantum correlation information Qc (coincidence image) based on the input first received light image Im1 using a JPD algorithm or the like. The quantum correlation information Qc may be a plurality of spatial correlation images acquired by the first light L1 and the second light L2 at different times. The quantum correlation information Qc is output to the inference unit 57.

[0084] The inference unit 57 receives the quantum correlation information from the calculation unit 56, performs inference based on the quantum correlation information, and outputs an inference result. The inference unit 57 may output information about an object frame, which is a frame in which the object S is detected, as the inference result.

[0085] The inference unit 57 can perform inference using artificial intelligence (AI). The inference unit 57 is provided with a trained model that has been previously subjected to machine learning by a learning device. The learning device can generate the trained model using, for example, quantum correlation information Qc. The inference unit 57 may infer the object frame based on the quantum correlation information Qc and the trained model. Note that the learning device may further learn based on the first received light image Im1 (illumination image) in addition to the quantum correlation information Qc, and the inference unit 57 may perform inference based on the quantum correlation information Qc, the first received light image Im1, and the trained model. This can improve the inference accuracy.

[0086] The inference unit 57 can calculate the flight time of light based on the inferred object frame, and calculate distance information Ds to the object S according to this flight time. There are various methods of machine learning in the learning device, such as reinforcement learning, semi-supervised learning, and unsupervised learning. There are no limitations on the machine learning method as long as it is possible to execute learning that handles images. From the viewpoint of enabling complex inference, a method based on deep learning is preferable.

[0087] <Example of processing by the analysis unit 500f> Fig. 13 is a flow diagram showing an example of processing by the analysis unit 500f. Fig. 13 shows processing by the analysis unit 500f from receiving the first received light image Im1 from the light receiving unit 400b via the input unit 51 to outputting distance information Ds.

[0088] First, in step S21, the analysis unit 500f causes the calculation unit 56 to calculate the quantum correlation information Qc based on the first received light image Im1.

[0089] Next, in step S22, the analysis unit 500f causes the inference unit 57 to infer an object frame based on the quantum correlation information Qc received from the calculation unit 56 and the learning model.

[0090] Next, in step S23, the analysis unit 500f causes the inference unit 57 to calculate the time of flight of light based on the inferred object frame.

[0091] Next, in step S24, the analysis unit 500f causes the inference unit 57 to obtain distance information Ds to the object S by calculation from the calculated flight time.

[0092] Next, in step S25, the analysis unit 500f outputs the distance information Ds calculated by the inference unit 57 via the output unit 55 to an external device.

[0093] In this manner, the analyzer 500f can receive the first received light image Im1 from the light projecting and receiving device 100b and output the distance image Ds.

[0094] <Main effects of the 1000f Distance Measuring System> As described above, in this embodiment, the analysis unit 500f includes an inference unit 57 that inputs quantum correlation information Qc acquired by the first light L1 and the second light L2 in a quantum entangled state, performs inference based on the quantum correlation information Qc, and outputs an inference result. The quantum correlation information Qc may be a plurality of spatial correlation images acquired by the first light L1 and the second light L2 at different times. The analysis unit 500f may also include a calculation unit 56 to which a first received light image Im1 (received light image) is input. The first received light image Im1 is obtained by receiving light including a first reflected light R1 generated when at least one of the first light L1 and the second light L2 is reflected by the object S, and the quantum correlation information Qc may be calculated by the calculation unit 56 and output to the inference unit 57. As described above, in this embodiment, a distance measuring system 1000f capable of performing inference based on light in a quantum entangled state can be provided.

[0095] The inference unit 57 may output information about the object frame, which is a frame in which the object S is detected, as an inference result. The analysis unit 500f can specify the object frame robustly against external light by the inference unit 57. In this embodiment, by using the information about the object frame specified by the inference unit 57, it is possible to provide a ranging system 1000f that is resistant to external light.

[0096] From another perspective, the distance measuring system 1000f may include an analysis unit 500f that inputs first information (first received light image Im1) including time-of-flight information of the first reflected light R1 generated when at least one of the first light L1 and the second light L2, which are in a quantum entangled state with each other, is reflected by the object S, and outputs an analysis result. The analysis result may include at least one of information on the object frame, which is a frame in which the object S is detected, time-of-flight information to the object S, and distance information to the object S. The analysis unit 500f may include an inference unit 57 that performs inference based on quantum correlation information calculated from the first information.

[0097] [Fifth embodiment] Next, a distance measuring system according to a fifth embodiment will be described. This embodiment is different from the fourth embodiment mainly in that a control unit controls the first light emitting unit and the light receiving unit, and the analysis unit calculates the driving conditions of the first light emitting unit and the light receiving unit based on the analysis result by the analysis unit and outputs a driving signal to the control unit.

[0098] 14 is a block diagram showing an example of the configuration of a distance measuring system 1000g according to the fifth embodiment. The distance measuring system 1000g includes a light projecting and receiving device 100g and an analysis unit 500g. The light projecting and receiving device 100g includes a control unit 300g.

[0099] The analysis unit 500g calculates the drive conditions of the first light-emitting unit 201 and the light-receiving unit 400 based on the analysis result by the analysis unit, and outputs a drive signal Dr to the control unit 300g. For example, the analysis unit 500g calculates, as the drive conditions, the number of frames for capturing the first received light image Im1 obtained by receiving light including the first reflected light R1. The control unit 300g can control the first light-emitting unit 201 and the light-receiving unit 400 according to the drive signal Dr from the analysis unit 500g.

[0100] 15 is a block diagram showing an example of a functional configuration of the analysis unit 500g. The analysis unit 500g includes a frame number calculation unit 58. The function of the frame number calculation unit 58 is realized by a processor such as a CPU 501 executing processing defined in a program stored in a non-volatile memory such as a ROM 502.

[0101] The frame number calculation unit 58 calculates the number of frames N for capturing the first received light image Im1 based on the quantum correlation information Qc calculated by the operation unit 56. The frame number N calculated by the frame number calculation unit 58 corresponds to, for example, the frame number N used in calculating the joint probability distribution of the JPD algorithm described above. The frame number N also corresponds to the driving conditions of the first light emitter 201 and the light receiver 400.

[0102] A drive signal Dr (see FIG. 14) corresponding to the frame number N calculated by the frame number calculation section 58 is output via the output section 55 to the control section 300g.

[0103] 16 is a block diagram showing an example of the functional configuration of the control unit 300g. The control unit 300g includes an emission control unit 31g and a light receiving control unit 33. Each function of the emission control unit 31g and the light receiving control unit 33 is realized by an electric circuit, a processor, or the like.

[0104] The light emission control unit 31g provides light emission timing to the laser light source 21 in response to the drive signal Dr from the analysis unit 500g. For example, as the number of frames N increases, the time interval at which the laser light source 21 emits pulsed light in response to the drive signal Dr becomes longer.

[0105] In response to the drive signal Dr from the analysis unit 500g, the light receiving control unit 33 sets the number of frames N for capturing the first received light image Im1 for the first light receiving unit 401. The first light receiving unit 401 can capture the first received light image Im1 using the set number of frames N.

[0106] A part of the functions of the analysis unit 500g may be provided in the control unit 300g, or a part of the functions of the control unit 300g may be provided in the analysis unit 500g. Furthermore, a part of the functions of the analysis unit 500g or a part of the functions of the control unit 300g may be realized by distributed processing of the analysis unit 500g and the control unit 300g.

[0107] <Example of operation of distance measurement system 1000g> Fig. 17 is a flow diagram showing an example of the operation of the distance measuring system 1000g. Fig. 17 shows the operation of the distance measuring system 1000g from calculating an appropriate number of frames based on the first received light image Im1 obtained by projecting the first light L1 and the second light L2, to outputting distance information S to the object S obtained by projecting the first light L1 and the second light L2 again according to the frame number. The distance measuring system 1000g starts the operation of Fig. 17 by using the projection of the first light L1 and the second light L2 as a trigger.

[0108] First, in step S31, the distance measuring system 1000g causes the first light receiving unit 401 to obtain a first received light image Im1.

[0109] Next, in step S32, the distance measuring system 1000g calculates the quantum correlation information Qc by the analysis unit 500g.

[0110] Next, in step S33, the distance measuring system 1000g calculates an optimized frame number N based on the quantum correlation information Qc by the analysis unit 500g. The distance measuring system 1000g may set a criterion for determining whether the frame number is appropriate or not in advance, and repeat the operations from projecting the first light L1 and the second light L2 to step S33 until the criterion is satisfied. The distance measuring system 1000g outputs a drive signal Dr according to the calculated frame number N to the control unit 300g by the analysis unit 500g.

[0111] Next, in step S34, the distance measuring system 1000g causes the control unit 300g to set the number of frames for capturing the first received-light image Im1 for the first light receiving unit 401 in accordance with the drive signal Dr.

[0112] Next, in step S35, the distance measuring system 1000g causes the control unit 300g to provide the laser light source 21 with the timing of light emission according to the drive signal Dr.

[0113] Next, in step S36, the distance measuring system 1000g projects the first light L1 and the second light L2 in accordance with the light emission timing given by the control unit 300g.

[0114] Next, in step S37, the distance measuring system 1000g causes the first light receiving unit 401 to obtain a first received light image Im1.

[0115] Next, in step S38, the distance measuring system 1000g calculates quantum correlation information Qc based on the first received light image Im1 by the analysis unit 500g.

[0116] Next, in step S39, the distance measuring system 1000g causes the analysis unit 500g to infer the object frame based on the quantum correlation information Qc and the learning model.

[0117] Next, in step S40, the distance measuring system 1000g calculates the time of flight of light based on the inferred object frame by the analysis unit 500g.

[0118] Next, in step S41, the distance measurement system 1000g acquires distance information Ds to the object S by calculation using the analysis unit 500g from the calculated flight time.

[0119] Next, in step S42, the distance measuring system 1000g outputs the distance information Ds to an external device by the analysis unit 500g.

[0120] In this manner, the distance measuring system 1000g can optimize the number of frames N for capturing the first received-light image Im1, and output the distance information Ds obtained according to the optimized number of frames N.

[0121] <Main effects of the 1000g Distance Measuring System> As described above, in this embodiment, the analysis unit 500g calculates the driving conditions of the first light-emitting unit 201 and the light-receiving unit 400 based on the analysis result by the analysis unit 500g, and outputs a driving signal Dr to the control unit 300g. For example, the analysis unit 500g may calculate the number of frames N for capturing the first received light image Im1 obtained by receiving light including the first reflected light R1 as the driving condition. The distance measurement system 1000g can reduce the decrease in distance measurement accuracy when the frame number N is small and reduce the increase in distance measurement time when the frame number N is large by calculating an appropriate frame number N using the frame number calculation unit 58. Other effects are almost the same as those of the fourth embodiment.

[0122] <Modification of the Fifth Embodiment> Next, a modified example of the fifth embodiment will be described. This modified example differs from the fifth embodiment mainly in that the inference unit infers an appropriate number of frames in addition to inferring an object frame.

[0123] The configuration of the distance measuring system according to the modified example of the fifth embodiment is different in that the inference unit 57 in Fig. 15 can infer an appropriate frame number N. In this case, the analysis unit 500g does not necessarily have to include the frame number calculation unit 58 in Fig. 15.

[0124] Fig. 18 is a flow diagram showing the operation of a distance measuring system according to a modification of the fifth embodiment. In step S53 of Fig. 18, the distance measuring system according to the modification of the fifth embodiment differs from the operation of the distance measuring system 1000g shown in Fig. 17 in that the inference unit 57 of the analysis unit 500g infers an optimized frame number N based on the quantum correlation information Qc. The operations of the other steps are almost the same as those of the steps shown in Fig. 17, so duplicated explanations will be omitted here.

[0125] In this modification, since the appropriate number of frames is inferred by the inference unit 57, it is possible to obtain an appropriate number of frames under various conditions.

[0126] Sixth embodiment Next, a distance measuring system according to the sixth embodiment will be described. In this embodiment, the light projecting and receiving device includes a second light emitting unit that emits a third light L3, which is classical light. The light receiving unit receives the first reflected light R1 and the second reflected light R2. A second received light image Im2 based on the second reflected light R2 is input to the analysis unit, and the analysis unit outputs an analysis result based on the first received light image Im1 and the second received light image Im2. The above points are different from the fifth embodiment.

[0127] <Configuration Example of Distance Measuring System 1000h According to Sixth Embodiment> 19 is a block diagram showing an example of the configuration of a distance measuring system 1000h according to the sixth embodiment. The distance measuring system 1000h differs from the distance measuring system 1000g according to the fifth embodiment in that the distance measuring system 1000h includes a light projecting and receiving device 100h and an analysis unit 500h. The light projecting and receiving device 100h includes a light emitting unit 200b.

[0128] 20 is a block diagram showing an example of a functional configuration of the analysis unit 500h. The analysis unit 500h differs from the analysis unit 500g according to the fifth embodiment in that the analysis unit 500h includes a second distance calculation unit 53. The analysis unit 500h can obtain second distance information Ds2 based on the second received-light image Im2 as the second information by the second distance calculation unit 53. The analysis unit 500h can output at least one of the first distance information Ds1 and the second distance information Ds2 to an external device by the output unit 55.

[0129] <Example of operation of the distance measurement system 1000h> Fig. 21 is a flow diagram showing an example of the operation of the distance measuring system 1000h. The operations of steps S71 to S80 in Fig. 21 are almost the same as the operations of steps S31 to S40 shown in Fig. 17, so a duplicated description will be omitted here.

[0130] In step S81, the distance measuring system 1000h acquires first distance information Ds1 to the object S by calculation using the analysis unit 500h from the calculated flight time.

[0131] Next, in step S82, the distance measuring system 1000h outputs the first distance information Ds1 to an external device by the analysis unit 500h.

[0132] Next, in step 83, the distance measuring system 1000h uses the second light receiving unit 402 to obtain a second received light image Im2.

[0133] Next, in step S84, the distance measuring system 1000h acquires the second distance information Ds2 by calculation using the analysis unit 500h.

[0134] Next, in step S85, the distance measuring system 1000h outputs the second distance information Ds2 to an external device by the analysis unit 500h.

[0135] In this manner, the distance measuring system 1000h can output the second distance information Ds2 obtained from the third light L3, which is classical light, in addition to the first distance information Ds1 obtained from the first light L1 and the second light L2.

[0136] <Main effects of the 1000h Distance Measuring System> As described above, the distance measurement system 1000h obtains the second distance information Ds2 from the third light L3 in addition to the first distance information Ds1 obtained from the first light L1 and the second light L2. The third light L3 has a larger amount of light than the first light L1 and the second light L2, and therefore the measurement range of the measurable distance and the like is wider. As described above, in this embodiment, it is possible to provide a distance measurement system 1000h that has a wider measurable range and is resistant to external light. Other effects are almost the same as those of the fifth embodiment.

[0137] From another perspective, in this embodiment, the analysis unit 500h may further receive a second received light image Im2 (second information) including time-of-flight information of the second reflected light R2 generated when the third light L3, which is classical light, is reflected by the object S. The analysis unit 500h may output an analysis result based on the first received light image Im1 (first information) and the previous second received light image Im2.

[0138] Although the preferred embodiments have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the claims.

[0139] The ordinal numbers, quantities, and other numbers used in the description of the embodiments are all provided as examples to specifically explain the technology of the present invention, and the present invention is not limited to the exemplified numbers. Furthermore, the connection relationships between the components are provided as examples to specifically explain the technology of the present invention, and do not limit the connection relationships that realize the functions of the present invention.

[0140] The division of blocks in the functional block diagram is an example, and multiple blocks may be realized as one block, one block may be divided into multiple blocks, or some functions may be moved to other blocks. Furthermore, the functions of multiple blocks having similar functions may be processed in parallel or in time-sharing by a single piece of hardware or software. Furthermore, some or all of the functions may be distributed to multiple computers.

[0141] For example, aspects of the present invention are as follows. <1> The light-emitting / receiving device includes a first light-emitting unit that emits first light and second light that are in a quantum entangled state with each other, a second light-emitting unit that emits third light, which is classical light, and a light-receiving unit, wherein at least one of the first light and the second light is reflected by an object as a first reflected light, and the third light is reflected by the object as a second reflected light, and the light-receiving unit receives the first reflected light and the second reflected light. <2> The light receiving unit includes a first light receiving unit that receives light including the first reflected light, and a second light receiving unit that receives light including the second reflected light. <1> The light projecting and receiving device is as described above. <3> The first light receiving unit includes a single photon detector that detects a single photon, and the second light receiving unit includes a light amount detector that detects an amount of received light by integrating the amount of received light for a predetermined period or a predetermined number of times. <2> The light projecting and receiving device is as described above. <4> the first light is emitted to the outside, the second light is emitted to an optical path along which the light is guided to the light receiving unit, and only the first light of the first light and the second light is reflected by the object to become the first reflected light; <1> From the above <3> The light emitting and receiving device according to any one of the above items. <5> The above <1> From the above <4> and an analysis unit that receives a first received light image from a first light receiving unit provided in the light receiving unit and receives a second received light image from a second light receiving unit provided in the light receiving unit, wherein the analysis unit outputs at least one of first distance information based on the first received light image and second distance information based on the second received light image. <6> the analysis unit outputs at least one of the first distance information and the second distance information selected based on an amount of received light in the second received light image; <5> The present invention relates to a distance measuring system. <7> the analysis unit outputs the first distance information when the amount of received light is a first value, and outputs the second distance information when the amount of received light is a second value greater than the first value; <6> The present invention relates to a distance measuring system. <8> The distance measurement system includes an analysis unit that receives first information including time-of-flight information of a first reflected light generated when at least one of a first light and a second light in a quantum entangled state is reflected by an object, and second information including time-of-flight information of a second reflected light generated when a third light, which is classical light, is reflected by the object, and the analysis unit outputs at least one of first distance information based on the first information and second distance information based on the second information. <9> the analysis unit outputs at least one of the first distance information and the second distance information selected based on the second information; <8> The present invention relates to a distance measuring system. <10> the second information includes information regarding an amount of the second reflected light received by a light receiving unit, and the analysis unit outputs the first distance information when the amount of the received light is a first value, and outputs the second distance information when the amount of the received light is a second value greater than the first value; <9> The present invention relates to a distance measuring system. [Explanation of symbols]

[0142] 100, 100b, 100c, 100d, 100e, 100g, 100h emitter / receiver 200, 200b, 200c Light emitting part 201 First light emitting part 202 Second light emitting part 21 Laser light source 22 Nonlinear Optical Crystals 23 Beam splitter 24 Reflective Mirror 300, 300g Control section 31, 31g Light emission control unit 32 Input / output section 33 Light receiving control section 400, 400b light receiving section 401 1st light receiving section 402 2nd light receiving section 500, 500f, 500g, 500h analysis department 501 CPU 502 ROM 503 RAM 504 HDD / SSD 505 Communication I / F 51, 51f Input section 52 First distance calculation unit 53 Second distance calculation unit 54 Selection section 55 Output section 56 Arithmetic section 57 Reasoning part 58 Frame Number Calculation Unit 1000, 1000c, 1000d, 1000e, 1000f, 1000g, 1000h Distance Measuring System A System Bus Dr Drive signal Ds Distance Information Ds1 First distance information Ds2 Second distance information Im1 First received image Im2 Second received light image L0 excitation light L1 1st light L2 2nd light L3 Third Light N Number of frames Qc Quantum Correlated Information R1 1st reflected light R2 2nd reflected light S object [Prior art documents] [Patent documents]

[0143] [Patent Document 1] Special Publication No. 2012-522983

Claims

1. a first light emitting unit that emits a first light and a second light that are in a quantum entangled state with each other; A second light emitting unit that emits a third light that is classical light; A light receiving unit, At least one of the first light and the second light is reflected by an object to become a first reflected light, The third light is reflected by the object to become a second reflected light, The light receiving unit receives the first reflected light and the second reflected light.

2. The light receiving unit is a first light receiving unit that receives light including the first reflected light; The light projecting and receiving device according to claim 1 , further comprising: a second light receiving section that receives light including the second reflected light.

3. the first light receiving unit includes a single-photon detector that detects a single photon; 3. The light emitting and receiving device according to claim 2, wherein the second light receiving section includes a light amount detector that detects the amount of received light by integrating the amount of received light for a predetermined period or a predetermined number of times.

4. The first light is emitted to the outside, The second light is emitted to an optical path along which the second light is guided to the light receiving unit, 2. The light projecting and receiving device according to claim 1, wherein only the first light of the first light and the second light is reflected by the object to become the first reflected light.

5. A light projecting and receiving device according to any one of claims 1 to 4, an analyzing unit that receives a first received light image from a first light receiving unit included in the light receiving unit and receives a second received light image from a second light receiving unit included in the light receiving unit; A distance measuring system in which the analysis unit outputs at least one of first distance information based on the first received light image and second distance information based on the second received light image.

6. The distance measuring system according to claim 5 , wherein the analysis section outputs at least one of the first distance information and the second distance information selected based on an amount of received light in the second received-light image.

7. The distance measuring system according to claim 6 , wherein the analysis unit outputs the first distance information when the amount of received light is a first value, and outputs the second distance information when the amount of received light is a second value greater than the first value.

8. First information including time-of-flight information by a first reflected light generated when at least one of a first light and a second light in a quantum entangled state is reflected by an object; and and second information including time-of-flight information of a second reflected light generated when a third light, which is classical light, is reflected by the object, A ranging system in which the analysis unit outputs at least one of first distance information based on the first information and second distance information based on the second information.

9. The distance measuring system according to claim 8 , wherein the analysis unit outputs at least one of the first distance information and the second distance information selected based on the second information.

10. the second information includes information regarding an amount of the second reflected light received by a light receiving unit, The ranging system of claim 9 , wherein the analysis unit outputs the first distance information when the amount of received light is a first value, and outputs the second distance information when the amount of received light is a second value greater than the first value.

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