Measurement device, irradiation device, and bandpass filter

Abstract

A measurement device is provided with: a light-emitting unit (12) that emits light having a wavelength corresponding to the temperature in a predetermined wavelength range; an optical filter through which light of a predetermined wavelength band passes and through which reflected light of the light irradiated from the light-emitting unit (12) passes; a light-receiving sensor (22) having a plurality of light-receiving elements (222); and a dispersion element (25) that is disposed between the filter and the light-receiving sensor (22) and disperses the light that has passed through the filter toward the two or more light-receiving elements.

Description

Technical Field

[0001] The present disclosure relates to an assay device, an illumination device, and a bandpass filter. Background Art

[0002] Patent Document 1 describes a distance measuring device that measures the distance to a reflecting object based on the flight time of light from emitting pulse light to receiving reflected light.

[0003] Prior art literature

[0004] Patent Document 1: Japanese Patent Application Publication No. 2021-152536 Summary of the invention

[0005] Technical problem to be solved by the invention

[0006] In order to reduce the influence of interference caused by background light such as sunlight, a bandpass filter is sometimes provided in the optical system for receiving light. However, when the wavelength of light emitted from the light emitting unit changes according to the temperature, it is necessary to expand the passband of the bandpass filter. As a result, the interference mixed into the light receiving data of the light receiving element may increase, and the measurement accuracy may decrease.

[0007] In addition, when a light emitting unit (light source) is formed by two-dimensionally arranging VCSELs as light emitting elements, a plurality of light emitting elements are arranged at intervals due to gaps between emitters. As a result, gaps are generated in the light irradiated to the measurement area, resulting in an area that cannot be measured.

[0008] A first object of the present disclosure is to suppress the influence of interference.

[0009] A second object of the present disclosure is to suppress the generation of a region where light cannot be irradiated.

[0010] Technical solutions for solving technical problems

[0011] One method of the present disclosure for achieving the above-mentioned first purpose is a measuring device, comprising: a light-emitting unit, which irradiates light of a wavelength corresponding to a temperature within a specified wavelength band; a filter, which allows the light of the specified wavelength band to pass through and allows the reflected light of the light irradiated from the light-emitting unit to pass through; a light-receiving sensor, which has a plurality of light-receiving elements; and a dispersion element, which is arranged between the light filter and the light-receiving sensor, so as to disperse the light passing through the filter to two or more of the light-receiving elements.

[0012] Another method of the present disclosure for achieving the above-mentioned first purpose is a measuring device, comprising: a light-emitting unit that irradiates light of a wavelength corresponding to temperature; a bandpass filter that allows reflected light of the light irradiated from the light-emitting unit to pass; and a light-receiving sensor that receives light that has passed through the bandpass filter so that the wavelength of the light that can pass through the bandpass filter changes according to the temperature.

[0013] One method of the present disclosure for achieving the above-mentioned second purpose is a measuring device, comprising: a light-emitting unit, which has a plurality of light-emitting elements arranged at intervals; an optical system, which has a plurality of super lenses that offset the optical axis, and between the lights of the plurality of light-emitting elements irradiated through a certain super lens, the light from the light-emitting elements is irradiated through another of the super lenses.

[0014] In addition, the technical problems disclosed in the present application and their solutions are clarified through specific implementations and drawings.

[0015] Effects of the Invention

[0016] According to the present disclosure, the influence of interference can be suppressed.

[0017] In addition, according to the present disclosure, it is possible to suppress the generation of a region where light cannot be irradiated. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is an explanatory diagram of the overall structure of the measuring device 1.

[0019] Figure 2 It is a schematic explanatory diagram of the measuring device 1.

[0020] Figure 3 This is a timing chart for explaining an example of a measurement method.

[0021] Figure 4 It is an explanatory diagram of the light receiving unit 20 of this embodiment.

[0022] Figure 5 It is an explanatory diagram of the light receiving unit 20 of a reference example.

[0023] Figure 6 This is a correspondence table used for the first measurement method.

[0024] Figure 7 This is an explanatory diagram of the first measurement method.

[0025] Figure 8 This is an explanatory diagram of the first measurement method.

[0026] Fig. 9 This is an explanatory diagram of the first measurement method.

[0027] Fig.10 This is a table used for the second measurement method.

[0028] Fig.11 It is an explanatory diagram of the second measurement method.

[0029] Fig.12 It is an explanatory diagram of the correspondence relationship between the light emitting element 121 and the light receiving element 222 .

[0030] Fig.13 It is an explanatory diagram of another correspondence relationship between the light emitting element 121 and the light receiving element 222 .

[0031] Fig.14 It is an explanatory diagram of the overall structure of the measuring device 1001.

[0032] Fig.15 It is a schematic diagram for explaining the measuring device 1001.

[0033] Fig.16 This is a timing chart for explaining an example of a measurement method.

[0034] Fig.17 It is an explanatory diagram of the light receiving unit 1020 .

[0035] Fig.18 It is an explanatory diagram of the light receiving unit 1020 .

[0036] Fig.19 It is a schematic explanatory diagram showing the characteristics of the band pass filter BPF according to the present embodiment.

[0037] Fig. 20 It is an enlarged explanatory diagram of the structure of the band pass filter BPF.

[0038] Fig.21 It is an enlarged explanatory diagram of the structure of the band pass filter BPF.

[0039] Fig. 22 It is a graph showing the characteristics of the band pass filter BPF.

[0040] Fig.23 is a graph showing another characteristic of the band pass filter BPF.

[0041] Fig.24 It is an explanatory diagram of a modified example of the arrangement of the bandpass filter BPF.

[0042] Fig.25 It is an explanatory diagram of the configuration of another band pass filter BPF'.

[0043] Fig.26 It is an explanatory diagram of the configuration of another band pass filter BPF'.

[0044] Fig. 27 It is an explanatory diagram of the configuration of another band pass filter BPF'.

[0045] Fig.28 It is an explanatory diagram of the overall structure of the measuring device 2001.

[0046] Fig.29 It is a schematic diagram for explaining the measuring device 2001.

[0047] Fig.30 This is a timing chart for explaining an example of a measurement method.

[0048] Fig.31 The diagram is an explanatory diagram of the arrangement of the light emitting elements 2121 of the light emitting unit 2012 .

[0049] Fig.32 2050 is a reference diagram for explaining light irradiated to the measurement region 2050 .

[0050] Fig.33 This is an explanatory diagram of light irradiated to the measurement region 2050 according to this embodiment.

[0051] Fig.34 It is an explanatory diagram of the lens unit 2015 .

[0052] Fig.35 1 is an explanatory diagram of an image of a light emitting point (irradiation spot) of the light emitting element 2121 formed by one super lens 2016 .

[0053] Fig.36 2016 is an explanatory diagram of an image of a light emitting point of the light emitting element 2121 (a group of irradiated light spots).

[0054] Fig.37 2016 is an explanatory diagram of images of light-emitting points of a plurality of light-emitting elements 2121 (a plurality of irradiation spot groups).

[0055] Fig.38 This is a diagram for explaining the optical conditions for causing two irradiation spots adjacent to each other in a predetermined direction to partially overlap.

[0056] Fig.39 This is a diagram for explaining the optical conditions for partially overlapping two irradiation spot groups adjacent to each other in a predetermined direction. DETAILED DESCRIPTION

[0057] Hereinafter, the mode for implementing the present disclosure will be described with reference to the drawings. In addition, in the following description, the same reference numerals are sometimes attached to the same or similar structures, and the repeated description is omitted.

[0058] [First embodiment]

[0059] <Overall structure>

[0060] Figure 1 It is an explanatory diagram of the overall structure of the measuring device 1. Figure 2 It is a schematic explanatory diagram of the measuring device 1.

[0061] In the following description, Figure 2Each direction is determined as shown. The Z direction is a direction along the optical axis of the light receiving optical system 24. In addition, the object 90 to be measured by the measuring device 1 is separated from the measuring device 1 in the Z direction. In addition, the X direction and the Y direction are directions perpendicular to the Z direction. In addition, the plurality of light emitting elements 121 constituting the light emitting unit 12 are arranged two-dimensionally along the X direction and the Y direction. The plurality of pixels 221 of the light receiving sensor 22 are also arranged two-dimensionally along the X direction and the Y direction.

[0062] The measuring device 1 is a device for measuring the distance to the object 90. The measuring device 1 is a device having a function as a so-called LiDAR (Light Detection and Ranging). The measuring device 1 emits measuring light, detects reflected light reflected from the surface of the object 90, and measures the time from the emission of the measuring light to the reception of the reflected light, thereby measuring the distance to the object 90 in a TOF (Time of flight) method. The measuring device 1 has an irradiation unit 10, a light receiving unit 20, and a control unit 30. In addition, the measuring device 1 of this embodiment has a temperature sensor 41.

[0063] The irradiation unit 10 is an irradiation device for irradiating the object 90 with measurement light. The irradiation unit 10 irradiates the measurement area 50 (see Figure 2 ) irradiates the measuring light. The irradiation unit 10 includes a light emitting unit 12 and an optical system for projecting light 14. The light emitting unit 12 is a component (light source) that emits light. For example, the light emitting unit 12 is composed of a vertical surface emitting laser (VCSEL) array chip. The light emitting unit 12 includes a plurality of light emitting elements 121 (for example, a vertical surface emitting laser; VCSEL), and the plurality of light emitting elements 121 are two-dimensionally arranged along the X direction and the Y direction. The optical system for projecting light 14 is an optical system that irradiates the light emitted from the light emitting unit 12 to the measuring area 50. The light emitting unit 12 is capable of causing each light emitting element 121 to emit light individually. Each light emitting element 121 of the light emitting unit 12 is associated with a specified area of ​​the measuring area 50 via the optical system for projecting light 14. The light emitted from a certain light emitting element 121 is irradiated to the corresponding area of ​​the measuring area 50 via the optical system for projecting light 14. However, the irradiation unit 10 may also be configured to emit light from the entire light emitting surface of the light emitting unit 12 and irradiate the entire measuring area 50 with light. In addition, the wavelength of the light emitted by the light emitting element 121 changes according to the temperature. This will be described later.

[0064] The light receiving unit 20 receives reflected light from the object 90. The light receiving unit 20 receives reflected light from the measurement area 50 (see Figure 2) of the measurement area 50. The light receiving unit 20 includes a light receiving sensor 22 and a light receiving optical system 24. The light receiving sensor 22 includes a plurality of pixels 221 arranged two-dimensionally. For example, in the case of a VGA light receiving sensor 22, 480×640 pixels 221 are arranged two-dimensionally. Each pixel 221 includes a light receiving element 222, and the light receiving element 222 outputs a signal (light receiving data) corresponding to the amount of light received. The light receiving optical system 24 is an optical system that enables the light receiving unit 20 to receive reflected light from the measurement area 50. The light receiving optical system 24 forms an image of the measurement area 50 on the light receiving surface of the light receiving sensor 22. Each pixel 221 of the light receiving sensor 22 is associated with a specified area of ​​the measurement area 50 via the light receiving optical system 24. A certain pixel 221 of the light receiving sensor 22 receives light (reflected light and background light) from a corresponding area of ​​the measurement area 50 via the light receiving optical system 24. In addition, each pixel 221 of the light receiving sensor 22 is associated with a predetermined light emitting element 121 of the light emitting unit 12. Light emitted from a certain light emitting element 121 is received by the corresponding pixel 221 via the light projection optical system 14 and the light receiving optical system 24. The light receiving sensor 22 and the light receiving optical system 24 will be described later.

[0065] The control unit 30 is responsible for controlling the measuring device 1. The control unit 30 controls the irradiation unit 10 and controls the light irradiated from the irradiation unit 10. In addition, the control unit 30 measures the distance to the object 90 in a TOF (Time of flight) manner based on the output result of the light receiving unit 20. The control unit 30 has a computing device and a storage device, which are not shown in the figure. The computing device is, for example, a computing processing device such as a CPU or a GPU. A part of the computing device can also be composed of an analog computing circuit. The storage device is composed of a main storage device and an auxiliary storage device, and is a device for storing programs and data. By executing the program stored in the storage device by the computing device, various processes for measuring the distance to the object 90 are performed. Figure 1 Functional blocks for various processes are shown.

[0066] The control unit 30 includes a setting unit 32, a timing control unit 34, and a distance measuring unit 36. The setting unit 32 performs various settings. The timing control unit 34 controls the processing timing of each unit. For example, the timing control unit 34 controls the timing of emitting light from the light emitting unit 12. The distance measuring unit 36 ​​measures the distance to the object 90. The distance measuring unit 36 ​​includes a signal processing unit 362, a time detection unit 364, and a distance calculation unit 366. The signal processing unit 362 processes the output signal (light receiving data) of the light receiving sensor 22. The time detection unit 364 detects the flight time of light (the time from the irradiation of light to the arrival of reflected light). The distance calculation unit 366 calculates the distance to the object 90.

[0067] Figure 3This is a timing chart for explaining an example of a measurement method.

[0068] The control unit 30 (timing control unit 34 ) causes the light emitting unit 12 of the irradiation unit 10 to emit pulse light at a predetermined cycle. Figure 3 The upper side of represents the timing (emission timing) of the light emitting unit 12 emitting pulsed light. The light emitted from the light emitting unit 12 is irradiated to the measurement area 50 via the light projection optical system 14. The light reflected from the surface of the object 90 in the measurement area 50 is received by the light receiving sensor 22 via the light receiving optical system 24. The pixel 221 of the light receiving sensor 22 receives the pulsed reflected light. Figure 3 The center of represents the arrival timing of the pulsed reflected light (arrival timing). Figure 3 The lower side of represents pixel data S of a certain pixel 221 of the light receiving sensor 22 (light receiving data of the light receiving element 222 of a certain pixel 221 ). The pixel data S of the light receiving sensor 22 is data indicating the amount of light received by the pixel 221 .

[0069] The control unit 30 (timing control unit 34) may emit light from all the light emitting elements 121 of the light emitting unit 12 and irradiate the entire measurement area 50 with light, or may emit light from a part of the light emitting elements 121 of the light emitting unit 12 (for example, one light emitting element 121) and irradiate only a predetermined area of ​​the measurement area 50 with light. When light is emitted from a part of the light emitting elements 121 of the light emitting unit 12 (for example, one light emitting element 121), the control unit 30 (signal processing unit 362) acquires the pixel data S of the pixel 221 corresponding to the light emitting element 121 that emits light. The pixel data S acquired by the control unit 30 will be described later.

[0070] The distance measuring unit 36 ​​(signal processing unit 362) of the control unit 30 detects the arrival timing of the reflected light based on the pixel data S of each pixel 221. For example, the signal processing unit 362 detects the arrival timing of the reflected light based on the timing of the peak value of the pixel data of each pixel 221.

[0071] The distance measuring unit 36 ​​(time detection unit 364) detects the time Tf from the irradiation light to the arrival of the reflected light based on the emission timing of the light and the arrival timing of the light. The time Tf corresponds to the time for the light to go back and forth between the measuring device 1 and the object 90. Then, the distance measuring unit 36 ​​(distance calculation unit 366) calculates the distance L to the object 90 based on the time Tf. In addition, when the time from the irradiation light to the arrival of the reflected light is set to Tf and the speed of light is set to C, the distance L is L=C×Tf / 2. The control unit 30 calculates the distance to the object 90 for each pixel 221 based on the time Tf detected for each pixel 221 of the light receiving unit 20, thereby generating a distance image.

[0072] <About the light receiving unit 20>

[0073] Figure 5 It is an explanatory diagram of the light receiving unit 20 of a reference example.

[0074] The light receiving optical system 24 has a focusing lens 241 and a bandpass filter BPF. The focusing lens 241 is an optical element that forms an image of the measurement area 50 on the light receiving surface of the light receiving sensor 22. The bandpass filter BPF is a filter that allows light of a specific wavelength to pass through and cuts off light other than the specific wavelength. In the following description, the wavelength band of light passing through the bandpass filter BPF is sometimes referred to as a "passband", and the wavelength band of light cut off by the bandpass filter BPF is sometimes referred to as a "cutoff band". The bandpass filter BPF needs to transmit reflected light, so it can at least transmit the wavelength of light irradiated from the light emitting unit 12. That is, the passband of the bandpass filter BPF needs to include at least the wavelength of light emitted from the light emitting unit 12. Since the light receiving optical system 24 is equipped with a bandpass filter BPF, it can cut off the light of the cutoff band in the background light such as sunlight, so the influence of interference caused by the background light can be suppressed.

[0075] On the other hand, the wavelength λ of the light emitted from the light emitting section 12 changes according to the temperature. For example, when the temperature of the light emitting section 12 rises, the wavelength λ of the light emitted from the light emitting section 12 becomes longer. Here, as an example, the wavelength λ of the light emitted from the light emitting section 12 changes in the range of 875 to 935 nm according to the temperature. In addition, it is assumed that the temperature of the light emitting section 12 changes in the range of T1 to T3, the wavelength λ1 at the temperature T1 is 875 nm, the wavelength λ2 at the temperature T2 is 905 nm, and the wavelength λ3 at the temperature T3 is 935 nm. The light emitting section 12 emits light of a wavelength λ corresponding to the temperature within the wavelength band of λ1 (=875 nm) to λ3 (=935 nm).

[0076] The bandpass filter BPF needs to transmit the wavelength of the light irradiated from the light emitting section 12. Therefore, when the wavelength of the light emitted from the light emitting section 12 changes within a specified band (the range of λ1 (=875nm) to λ3 (=935nm)) depending on the temperature, the bandpass filter BPF needs to transmit the light in the band (the range of λ1 to λ3). That is, the passband of the bandpass filter BPF needs to be expanded to include the entire band of light emitted from the light emitting section 12 (the range of λ1 to λ3). However, as a result of the passband expansion of the bandpass filter BPF, the background light (the light in the passband of the background light) passing through the bandpass filter BPF increases. Therefore, in the case of the structure shown in the reference example, the interference contained in the pixel data S (data representing the amount of light received by the pixel 221) increases.

[0077] Figure 4 It is an explanatory diagram of the light receiving unit 20 of this embodiment.

[0078] The light receiving optical system 24 of this embodiment has a bandpass filter BPF and a dispersion element 25. In addition, the light receiving optical system 24 in the figure has a condenser lens 241, but as described later, the light receiving optical system 24 may not have the condenser lens 241. In this embodiment, the passband of the bandpass filter BPF is also set to include the entire wavelength band of light emitted from the light emitting unit 12 (the range of λ1 (=875nm) to λ3 (=935nm)).

[0079] The dispersion element 25 is an optical element that disperses light. The dispersion element 25 is arranged between the bandpass filter BPF and the light receiving sensor 22. The light that has passed through the bandpass filter BPF enters the dispersion element 25, and the light dispersed by the dispersion element 25 enters the light receiving element 222 of the light receiving sensor 22. The dispersion element 25 of the present embodiment is set to disperse the light that has passed through the bandpass filter BPF (the light of the passband of the bandpass filter BPF) across a plurality of light receiving elements 222. In other words, the dispersion element 25 splits the light that has passed through the bandpass filter BPF into a plurality of light receiving elements 222. Here, sometimes three light receiving elements 222 are associated with a certain light emitting element 121, and these three light receiving elements 222 are respectively referred to as a first light receiving element 222A, a second light receiving element 222B, and a third light receiving element 222C. In addition, the light receiving data of the first light receiving element 222A is sometimes expressed as S1, the light receiving data of the second light receiving element 222B is expressed as S2, and the light receiving data of the third light receiving element 222C is expressed as S3. The dispersion element 25 disperses the light reaching from a predetermined area of ​​the measurement area 50 corresponding to the light emitting element 121 (the area on the measurement area 50 irradiated with the light emitted from the light emitting element 121), that is, the light of the passband of the bandpass filter BPF, over the three light receiving elements 222 (the first light receiving element 222A, the second light receiving element 222B, and the third light receiving element 222C) corresponding to the light emitting element 121.

[0080] The range in which the dispersion element 25 disperses the light in the passband of the bandpass filter BPF is not limited to the range covering three light receiving elements 222 , and may be any range covering two or more light receiving elements 222 .

[0081] The dispersion element 25 may be composed of a prism, a diffraction grating, a metamaterial, etc. A metamaterial is an optical element in which a microstructure smaller than the wavelength of light is arranged on a substrate (e.g., a glass substrate). The dispersion element 25 may be composed of a metamaterial in which microstructures are arranged in three dimensions, or may be composed of a metamaterial (metasurface) in which microstructures are arranged in two dimensions.

[0082] By using metamaterials, it is possible to construct an optical element (superlens) having a light-focusing function. Therefore, in the case where the dispersive element 25 of the present embodiment is constructed by metamaterials, the dispersive element 25 can also have the function of focusing the light that has passed through the bandpass filter BPF on the light-receiving sensor 22 (light-focusing function). Thus, the miniaturization of the light-receiving optical system 24 can be achieved. In addition, in the case where the dispersive element 25 constructed by metamaterials has a light-focusing function, the light-receiving optical system 24 may not have the focusing lens 241 in the figure. On the other hand, since the light-receiving optical system 24 has the focusing lens 241, it is not necessary to make the dispersive element 25 also have a light-focusing function, so the design constraints of the dispersive element 25 are reduced, and it is easy to construct the dispersive element 25 by metamaterials.

[0083] In addition, metamaterials can be used to form an optical element with a polarization filtering function. Therefore, in the case where the dispersive element 25 of the present embodiment is formed by a metamaterial, the dispersive element 25 can have the function of passing light vibrating in a specified direction and absorbing light vibrating in a direction intersecting the specified direction (polarization filtering function). For example, in the case where the light emitted by the light emitting unit 12 is light vibrating in a specified direction, the dispersive element 25 formed by the metamaterial passes light vibrating in a specified direction and absorbs light vibrating in a direction intersecting the specified direction, thereby suppressing the influence of interference. In addition, for example, the dispersive element 25 has a polarization filtering function with a polarization axis in a vertical direction and an absorption axis in a horizontal direction, thereby allowing reflected light directly arriving from the object 90 to pass through and absorbing reflected light reflected on the road surface (light vibrating in a horizontal direction). In this way, since the dispersive element 25 has a polarization filtering function, the influence of interference caused by unnecessary light can be suppressed.

[0084] The dispersion element 25 may also be formed of a prism or a diffraction grating. However, in the case where the dispersion element 25 is formed of a prism, the deflection angle of light is small, so in order to disperse the light to a plurality of light receiving elements 222, the interval between the dispersion element 25 and the light receiving sensor 22 needs to be set longer. In addition, in the case where the dispersion element 25 is formed of a diffraction grating, if the number of lines of the diffraction grating is small, then, like a prism, the interval between the dispersion element 25 and the light receiving sensor 22 needs to be set longer. In addition, even if the dispersion element 25 is formed of a diffraction grating having a large number of lines, the intensity of light received by the light receiving element 222 is reduced due to the loss of light corresponding to the diffraction efficiency. In contrast, in the case where the dispersion element 25 is formed of a metamaterial, the interval between the dispersion element 25 and the light receiving sensor 22 can be set short, and the reduction in the intensity of light received by the light receiving element 222 can also be suppressed. For example, when the dispersion element 25 is composed of a prism, the distance between the dispersion element 25 and the light receiving sensor 22 needs to be set to about tens of mm. In contrast, when the dispersion element 25 is composed of a metamaterial, the distance between the dispersion element 25 and the light receiving sensor 22 can be set to about 10 μm.

[0085] For example, when the temperature is T1, the light emitting unit 12 emits light of wavelength λ1 (=875nm), and the reflected light of wavelength λ1 is split toward the first light receiving element 222A by the dispersion element 25. Also, when the temperature is T2, the light emitting unit 12 emits light of wavelength λ2 (=905nm), and the reflected light of wavelength λ2 is split toward the second light receiving element 222B by the dispersion element 25. Also, when the temperature is T3, the light emitting unit 12 emits light of wavelength λ3 (=935nm), and the reflected light of wavelength λ3 is split toward the third light receiving element 222C by the dispersion element 25. In this way, the dispersion element 25 splits the reflected light (the light of the wavelength emitted by the light emitting unit 12) toward the light receiving element 222 in the direction corresponding to the wavelength.

[0086] Among the background light, the background light with wavelengths in the range of wavelengths λ1 to λ3 passes through the bandpass filter BPF. In the present embodiment, the background light that has passed through the bandpass filter BPF is incident on the dispersion element 25 and dispersed over the three light receiving elements 222. Therefore, in the case of the structure shown in the present embodiment, the influence of interference contained in the pixel data S (data indicating the amount of light received by the pixel 221; light receiving data of the light receiving element 222 that receives the reflected light) can be reduced to about 1 / 3 compared with the reference example. In the case of the structure shown in the present embodiment, the SN ratio is improved to about 3 times compared with the reference example.

[0087] like Figure 1As shown, the measuring device 1 includes a temperature sensor 41. The temperature sensor 41 is a sensor for measuring the temperature of the measuring device 1 (particularly the temperature of the light emitting unit 12). The temperature sensor 41 outputs temperature data indicating the measurement result to the control unit 30. The control unit 30 measures the distance based on the light receiving data of the light receiving element 222 corresponding to the temperature data of the temperature sensor 41. This point will be described below.

[0088] <First measurement method>

[0089] Figure 6 This is a correspondence table used for the first measurement method.

[0090] The signal processing unit 362 of the control unit 30 stores in advance Figure 6 In the correspondence table, the temperature T and the light receiving data to be used as the pixel data S are associated with each other.

[0091] In addition, when the temperature is T1 to T12, the light emitting unit 12 emits light with a wavelength of 875 to 895 nm, and the dispersion element 25 separates the light of this wavelength band to the first light receiving element 222A. When the temperature is T12 to T23, the light emitting unit 12 emits light with a wavelength of 895 to 915 nm, and the dispersion element 25 separates the light of this wavelength band to the second light receiving element 222B. When the temperature is T23 to T3, the light emitting unit 12 emits light with a wavelength of 915 to 935 nm, and the dispersion element 25 separates the light of this wavelength band to the third light receiving element 222C.

[0092] Figure 7 to Figure 9 This is an explanatory diagram of the first measurement method.

[0093] The signal processing unit 362 refers to the correspondence table based on the temperature data obtained from the temperature sensor 41 and determines the light receiving data to be used as the pixel data S. For example, when the temperature data of the temperature sensor 41 is in the range of T1 to T12 (here, greater than T1 and less than T12), Figure 7 As shown in FIG. 1 , the signal processing unit 362 obtains the light receiving data S1 of the first light receiving element 222A from the three light receiving elements 222 (the first light receiving element 222A, the second light receiving element 222B, and the third light receiving element 222C) corresponding to the light emitting element 121 emitting light based on the correspondence table. Similarly, when the temperature data of the temperature sensor 41 is in the range of T12 to T23, the control unit 30 Figure 8 As shown in FIG. 1 , the light receiving data S2 of the second light receiving element 222B is obtained based on the correspondence table. In addition, when the temperature data of the temperature sensor 41 is in the range of T23 to T3, the control unit 30 Fig. 9As shown, based on the correspondence table, the light receiving data S3 of the third light receiving element 222C is obtained. The signal processing unit 362 obtains the pixel data S of the pixel 221 corresponding to the light emitting element 121 by obtaining the light receiving data from the light receiving element 222 selected according to the temperature.

[0094] The distance measuring unit 36 ​​(signal processing unit 362) of the control unit 30 generates a signal based on the light receiving data (pixel data S of the pixel 221; see Figure 3 ), and detects the arrival timing of the reflected light. Then, the distance measuring unit 36 ​​(time detecting unit 364) detects the time Tf from the irradiation light to the arrival of the reflected light based on the emission timing of the light and the arrival timing of the light. In addition, the distance measuring unit 36 ​​(distance calculating unit 366) calculates the distance L to the object 90 based on the time Tf.

[0095] However, in the case of the measuring device 1 using the first measuring method, when the temperature data of the temperature sensor 41 is changed under the condition (reference condition) that the first light receiving element 222A to the third light receiving element 222C output predetermined light receiving data, the control unit 30 outputs different distances. This point will be described below.

[0096] First, the light emitting unit 12 is set to a specified temperature (reference temperature), a specified distance (reference distance) is set between the measuring device 1 and the object 90, and the first light receiving element 222A to the third light receiving element 222C output a specified light receiving data S1 to S3, and this condition is used as the reference condition. In addition, the reference temperature and the reference distance can be set arbitrarily. For example, when the reference temperature is T2, the light emitting unit 12 emits light of wavelength λ2 (=875nm), the dispersion element 25 splits the reflected light of wavelength λ2 to the second light receiving element 222B, and disperses the light of wavelengths λ1 to λ3 passing through the band pass filter BPF to the three light receiving elements 222 according to the wavelength, and the three light receiving elements 222 respectively output the light receiving data S1 to S3 corresponding to the reference condition. In addition, since the temperature T2 is within the temperature range of T12 to T23, the control unit 30 Figure 8 As shown, the light receiving data S2 of the second light receiving element 222B is obtained as the pixel data S, and the distance calculated based on the pixel data S is output.

[0097] Next, under the above-mentioned reference condition, the temperature data of the temperature sensor 41 is changed. In addition, here, only the temperature data obtained by the control unit 30 is changed (in other words, only the virtual temperature data is input to the control unit 30), the wavelength of the light emitted by the light emitting unit 12 is the same as that in the reference condition, and the light receiving data output by the light receiving element 222 is also the same as that in the reference condition. For example, when the reference temperature is T2, even when the temperature data of the temperature sensor 41 is changed to T1, the light emitting unit 12 emits light of wavelength λ2 (=875nm), and the three light receiving elements 222 respectively output the same light receiving data S1 to S3 as those in the reference condition. If the temperature data of the temperature sensor 41 is changed under the reference condition, the light receiving data obtained by the control unit 30 changes, so the control unit 30 outputs a different distance. For example, if the temperature data of the temperature sensor 41 is changed from T2 to T1 under the reference condition, the temperature of the light emitting unit 12 and the distance between the measuring device 1 and the object 90 are maintained, and although the light receiving data S1 to S3 outputted by the first to third light receiving elements 222A to 222C are the same, the control unit 30 changes the outputted distance from the distance corresponding to the light receiving data S2 of the second light receiving element 222B to the distance corresponding to the light receiving data S1 of the first light receiving element 222A. In this way, in the case of the measuring device 1 using the first measuring method, if the temperature data of the temperature sensor 41 is changed under the condition (reference condition) that the light receiving element 222 outputs the predetermined light receiving data, the control unit 30 outputs a different distance. That is, by changing the temperature data of the temperature sensor 41 under the condition (reference condition) that the light receiving element 222 outputs the predetermined light receiving data, it is possible to verify that the distance is measured based on the light receiving data of the light receiving element 222 corresponding to the temperature data of the temperature sensor 41.

[0098] <Second measurement method>

[0099] The angle of the light emitted from the dispersion element 25 to the light receiving element 222 gradually changes according to the wavelength. Therefore, sometimes the dispersion element 25 reflects the light to the boundary portion of two light receiving elements 222 (for example, the first light receiving element 222A and the second light receiving element 222B), and the two light receiving elements 222 receive the reflected light. In such a case, it is advantageous to measure the distance based on the light receiving data of the two light receiving elements 222 that receive the reflected light, rather than measuring the distance based on the light receiving data of one of the three light receiving elements 222 as in the first measurement method. In the second measurement method, the distance can be measured based on the light receiving data of two or more light receiving elements 222 according to the temperature data.

[0100] Fig.10 is a graph for the second measurement method. Fig.11 It is an explanatory diagram of the second measurement method.

[0101] The storage unit (not shown) of the control unit 30 stores in advance Fig.10 The weight table shown. In the weight table, the temperature T corresponds to the weight coefficient. The weight coefficient is equivalent to the weight data corresponding to the temperature data of the temperature sensor 41. The weight coefficient includes a first weight coefficient W1, a second weight coefficient W2 and a third weight coefficient W3. The first weight coefficient W1 is a weight coefficient for the light receiving data S1 of the first light receiving element 222A. The second weight coefficient W2 is a weight coefficient for the light receiving data S2 of the second light receiving element 222B. The third weight coefficient W3 is a weight coefficient for the light receiving data S3 of the third light receiving element 222C.

[0102] The signal processing unit 362 obtains the weight coefficient (weight data) corresponding to the temperature data obtained from the temperature sensor 41 from the weight table stored in the storage unit. That is, the signal processing unit 362 refers to the weight table based on the temperature data obtained from the temperature sensor 41, and obtains the weight coefficients (first weight coefficient W1, second weight coefficient W2, and third weight coefficient W3) corresponding to the temperature data. Then, the signal processing unit 362 respectively obtains the light receiving data S1 to S3 of the three light receiving elements 222 (first light receiving element 222A, second light receiving element 222B, and third light receiving element 222C) corresponding to the light emitting element 121 emitting light, and weights the light receiving data S1 to S3 of each light receiving element 222 according to the weight coefficient, thereby calculating the pixel data S. Specifically, the signal processing unit 362 calculates the pixel data S based on the following formula.

[0103] [Formula 1]

[0104] SS=S1××W1+S2×W2+S3×W3

[0105] For example, in the case of temperature T1 (when reflected light of wavelength λ1 (=875nm) is split by the dispersion element 25 toward the first light receiving element 222A), the weight coefficients are set to W1=1, W2=0, and W3=0, respectively. In addition, in the case of temperature T2 (when reflected light of wavelength λ2 (=905nm) is split by the dispersion element 25 toward the second light receiving element 222B), the weight coefficients are set to W1=0, W2=1, and W3=0, respectively. In addition, in the case of temperature T3 (when reflected light of wavelength λ3 (=935nm) is split by the dispersion element 25 toward the third light receiving element 222C), the weight coefficients are set to W1=0, W2=0, and W3=1, respectively. Furthermore, when temperature T is an intermediate temperature between T1 and T2, W1 and W2 are set so that temperature T is closer to T1 than T2 and W1 becomes larger than W2 (W3 is set to zero). Thus, even in a state where the dispersion element 25 directs reflected light toward the boundary between the first light receiving element 222A and the second light receiving element 222B, the distance can be measured with high accuracy. In addition, when the temperature T is an intermediate temperature between T2 and T3, W2 and W3 are set (W1 is set to zero) so that W2 becomes larger than W3 as the temperature T approaches T3 relative to T2. Thus, even in a state where the dispersion element 25 directs reflected light toward the boundary between the second light receiving element 222B and the third light receiving element 222C, the distance can be measured with high accuracy.

[0106] Furthermore, the distance measuring unit 36 ​​(signal processing unit 362) of the control unit 30 detects the arrival timing of the reflected light based on the calculated pixel data S (see Figure 3 Then, the distance measuring unit 36 ​​(time detecting unit 364) detects the time Tf from the irradiation light to the arrival of the reflected light based on the emission timing of the light and the arrival timing of the light. In addition, the distance measuring unit 36 ​​(distance calculating unit 366) calculates the distance L to the object 90 based on the time Tf.

[0107] However, even in the case of the measuring device 1 that adopts the second measuring method, if the temperature data of the temperature sensor 41 changes under the condition (reference condition) that the light receiving element 222 outputs the prescribed light receiving data, the control unit 30 outputs a different distance. That is, by changing the temperature data of the temperature sensor 41 under the condition (reference condition) that the light receiving element 222 outputs the prescribed light receiving data, it is possible to verify that the distance is measured based on the light receiving data of the light receiving element 222 corresponding to the temperature data of the temperature sensor 41. In addition, in the case of the measuring device 1 that adopts the second measuring method, when the temperature data of the temperature sensor 41 is gradually changed, the distance output by the control unit 30 gradually changes.

[0108] <About irradiation method>

[0109] Fig.121 is an explanatory diagram of the corresponding relationship between the light emitting element 121 and the light receiving element 222. Fig.12 It is also a diagram for explaining the correspondence between the pixels 221 and the light receiving elements 222 .

[0110] As described above, the light emitting unit 12 includes a plurality of light emitting elements 121. Two adjacent light emitting elements 121 (#1, #2) among the plurality of light emitting elements 121 of the light emitting unit 12 are shown in the figure. In addition, the figure shows regions (#1, #2) on the measurement region 50 corresponding to the two light emitting elements 121 (#1, #2). In addition, the figure shows two pixels 221 (#1, #2) of the light receiving sensor 22 corresponding to the two light emitting elements 121 (#1, #2) or the two regions (#1, #2) on the measurement region 50. The two pixels 221 (#1, #2) correspond to the two light emitting elements 121 (#1, #2) of the light emitting unit 12, respectively. The light emitted from the light emitting element 121#1 is irradiated to the region #1 on the measurement region 50, and the light (reflected light and background light) from the region #1 is received by the pixel 221#1. In addition, the light emitted from the light emitting element 121 # 2 irradiates the region # 2 on the measurement region 50 , and the light from the region # 2 (reflected light and background light) is received by the pixel 221 # 2 .

[0111] exist Fig.12 In the illustrated embodiment, a plurality of (here, three) light receiving elements 222 are included in one pixel 221 of the light receiving sensor 22. Here, the dispersion element 25 of the light receiving optical system 24 disperses the light (reflected light and background light) arriving from the region #1 on the measurement region 50 over the plurality of light receiving elements 222 (here, the first light receiving element 222A to the third light receiving element 222C) belonging to the pixel 221 #1. Similarly, the dispersion element 25 of the light receiving optical system 24 disperses the light (reflected light and background light) arriving from the region #2 on the measurement region 50 over the plurality of light receiving elements 222 belonging to the pixel 221 #2.

[0112] exist Fig.12 In the embodiment, the multiple light receiving elements 222 corresponding to the light emitting element 121#1 (the multiple light receiving elements 222 belonging to the pixel 221#1) and the multiple light receiving elements 222 corresponding to the light emitting element 121#2 (the multiple light receiving elements 222 belonging to the pixel 221#2) are different and do not overlap. In this way, when the multiple light receiving elements 222 corresponding to one of the two light emitting elements 121 are different from the multiple light receiving elements 222 corresponding to the other light emitting element 121, the control unit 30 (timing control unit 34) can emit light from the two light emitting elements 121 at the same time. In addition, Fig.12In the case shown, the control unit 30 (timing control unit 34) can either emit light from all the light-emitting elements 121 of the light-emitting unit 12 and irradiate the entire measurement area 50 with light, or emit light from a part of the light-emitting elements 121 of the light-emitting unit 12 (for example, one light-emitting element 121) and irradiate the light only to a specified area of ​​the measurement area 50.

[0113] Fig.13 1 is a diagram for explaining another correspondence relationship between the light emitting element 121 and the light receiving element 222 . Fig.13 This is also a diagram for explaining another correspondence relationship between the pixels 221 and the light receiving elements 222 .

[0114] exist Fig.13 In the illustrated embodiment, one pixel 221 of the light receiving sensor 22 is composed of one light receiving element 222. Here, the dispersive element 25 of the light receiving optical system 24 separates the light (reflected light and background light) arriving from the region #1 on the measurement region 50 over the three light receiving elements 222 composed of the three pixels 221. In addition, the dispersive element 25 of the light receiving optical system 24 separates the light (reflected light and background light) arriving from the region #2 on the measurement region 50 over the three light receiving elements 222 composed of the three pixels 221.

[0115] exist Fig.13 In the embodiment, the plurality of light receiving elements 222 corresponding to the light emitting element 121#1 and the plurality of light receiving elements 222 corresponding to the light emitting element 121#2 partially overlap. Thus, when the plurality of light receiving elements 222 corresponding to the two light emitting elements 121 respectively partially overlap, the control unit 30 (timing control unit 34) does not emit light from the two light emitting elements 121 at the same time. In this case, the control unit 30 emits light from a part of the light emitting elements 121 (for example, one light emitting element 121) of the light emitting unit 12, and irradiates the light only to the prescribed area of ​​the measurement area 50. In addition, when light is emitted from two or more light emitting elements 121 at the same time, the control unit 30 (timing control unit 34) irradiates light from the plurality of light emitting elements 121 whose corresponding plurality of light receiving elements 222 do not overlap.

[0116] In addition, if Figure 4 As shown in FIG. 1 , it is preferred to arrange a condenser lens 241 in front of the dispersion element 25 (on the measurement region 50 side), and the condenser lens 241 is used to condense the light (reflected light and background light) arriving from different regions (#1, #2) on the measurement region 50 at different positions of the dispersion element 25. Fig.12 As shown, it is easy to configure the light receiving optical system 24 so that the plurality of light receiving elements 222 belonging to the pixel 221 # 1 and the plurality of light receiving elements 222 belonging to the pixel 221 # 2 do not overlap.

[0117] ===Conclusion===

[0118] The measuring device 1 of this embodiment includes a light emitting unit 12, a bandpass filter BPF (equivalent to a filter), a light receiving sensor 22, and a dispersion element 25. The light emitting unit 12 irradiates light of a wavelength corresponding to the temperature within a predetermined wavelength range. The bandpass filter BPF allows light of a predetermined wavelength range to pass, and allows reflected light of the light irradiated from the light emitting unit 12 to pass. The light receiving sensor 22 has a plurality of light receiving elements 222. The dispersion element 25 is arranged between the bandpass filter BPF and the light receiving sensor 22, and disperses the light that has passed through the bandpass filter BPF to two or more light receiving elements 222. According to such a structure, light of a wavelength corresponding to the temperature is irradiated from the light emitting unit 12, and after passing through the bandpass filter BPF, the light is dispersed by the dispersion element 25 to specific light receiving elements 222 corresponding to the wavelength. On the other hand, the background light that has passed through the bandpass filter BPF is dispersed by the dispersion element 25 over two or more light receiving elements 222. Therefore, the background light received by the light receiving element 222 that receives the reflected light can be reduced, and the influence of noise included in the light receiving data output from the light receiving element 222 that receives the reflected light can be suppressed.

[0119] The measuring device 1 of this embodiment further includes a temperature sensor 41 and a control unit 30, and the control unit 30 measures the distance based on the light receiving data of the light receiving element 222 corresponding to the temperature data of the temperature sensor 41. Thus, the distance can be measured based on the light receiving data with the influence of noise suppressed, so the measurement accuracy is improved.

[0120] In addition, the measuring device 1 of the present embodiment further includes a temperature sensor 41 and a control unit 30, and when the temperature data of the temperature sensor 41 changes under the condition (reference condition) that the light receiving element 222 outputs the predetermined light receiving data, the control unit 30 outputs a different distance. That is, by changing the temperature data of the temperature sensor 41 under the condition (reference condition) that the light receiving element 222 outputs the predetermined light receiving data, it is possible to verify that the distance is measured based on the light receiving data of the light receiving element 222 corresponding to the temperature data of the temperature sensor 41.

[0121] In addition, the measuring device 1 of the present embodiment includes a storage unit (refer to Fig.10 ). Then, the control unit 30 obtains the weight coefficient (weight data) corresponding to the temperature data of the temperature sensor 41 from the storage unit, and weights the light receiving data of each of the two or more light receiving elements 222 according to the weight coefficient, thereby calculating the light receiving data S, and measuring the distance based on the light receiving data S. Thus, even in a state where the dispersion element 25 directs the reflected light to the boundary portion of the light receiving element 222, the distance can be measured with high accuracy.

[0122] In addition, the dispersive element 25 of the present embodiment is made of a metamaterial. This allows the distance between the dispersive element 25 and the light receiving sensor 22 to be set short, and the measurement device 1 can be miniaturized.

[0123] When the dispersive element 25 is formed of a metamaterial, it is preferred that the dispersive element 25 has a light focusing function (a function of focusing light that has passed through the filter on the light receiving sensor 22). This allows the light receiving optical system 24 to be miniaturized. In addition, when the dispersive element 25 is formed of a metamaterial, it is preferred that the dispersive element 25 has a polarization filtering function (a function of allowing light vibrating in a predetermined direction to pass through and absorbing light vibrating in a direction intersecting the predetermined direction). This allows the influence of interference caused by unnecessary light to be suppressed.

[0124] Furthermore, the dispersion element 25 may be formed of a prism or a diffraction grating. In this way, the dispersion element 25 can be formed at low cost.

[0125] Furthermore, the measuring device 1 of the present embodiment includes a condenser lens 241 disposed between the bandpass filter BPF and the dispersion element 25. As a result, the dispersion element 25 does not need to also have a condenser function, and thus the constraints on the design of the dispersion element 25 can be reduced.

[0126] [Second embodiment]

[0127] <Overall structure>

[0128] Fig.14 It is an explanatory diagram of the overall structure of the measuring device 1001. Fig.15 It is a schematic diagram for explaining the measuring device 1001.

[0129] In the following description, Fig.15 The directions are determined as shown. The Z direction is a direction along the optical axis of the light receiving optical system 1024. In addition, the object 1090 to be measured by the measuring device 1001 is separated from the measuring device 1001 in the Z direction. In addition, the X direction and the Y direction are directions perpendicular to the Z direction. The X direction is the direction in which the optical axis of the light projecting optical system 1014 and the optical axis of the light receiving optical system 1024 are arranged. The Y direction is a direction perpendicular to the X direction and the Z direction.

[0130] The measuring device 1001 is a device for measuring the distance to the object 1090. The measuring device 1001 is a device having a function as a so-called LiDAR (Light Detection and Ranging). The measuring device 1001 emits measuring light, detects reflected light reflected from the surface of the object 1090, and measures the time from the emission of the measuring light to the reception of the reflected light, thereby measuring the distance to the object 1090 using the TOF method (Time of Flight). The measuring device 1001 includes an irradiation unit 1010, a light emitting unit 1020, and a control unit 1030.

[0131] The irradiation unit 1010 is an irradiation device for irradiating the object 1090 with measurement light. The irradiation unit 1010 irradiates the measurement area 1050 (see Fig.15 ) irradiates the measuring light. The irradiation unit 1010 includes a light emitting unit 1012 and an optical system for projecting light 1014. The light emitting unit 1012 is a component (light source) that emits light. For example, the light emitting unit 1012 is composed of a vertical surface emitting laser (VCSEL) array chip. The light emitting unit 1012 includes a plurality of light emitting elements 1121 (for example, a vertical surface emitting laser; VCSEL), and the plurality of light emitting elements 1121 are two-dimensionally arranged along the X direction and the Y direction. The optical system for projecting light 1014 is an optical system that irradiates the light emitted from the light emitting unit 1012 to the measuring area 1050. The light emitting unit 1012 is capable of causing each light emitting element 1121 to emit light individually. Each light emitting element 1121 of the light emitting unit 1012 is associated with a specified area of ​​the measuring area 1050 via the optical system for projecting light 1014. The light emitted from a certain light emitting element 1121 is irradiated to the corresponding area of ​​the measuring area 1050 via the optical system for projecting light 1014. However, the irradiation unit 1010 may also be configured to emit light from the entire light emitting surface of the light emitting unit 1012, and irradiate the entire measurement area 1050 with light. In addition, the light projection optical system 1014 may also include a rotatable reflector (e.g., a polygonal mirror), and the light of the light emitting unit 1012 is irradiated to the measurement area 1050 by rotating the reflector. In addition, the wavelength of the light irradiated by the light emitting unit 1012 changes according to the temperature. This point will be described later.

[0132] The light emitting unit 1020 receives reflected light from the object 1090. The light emitting unit 1020 receives reflected light from the measurement area 1050 (see Fig.15) of the measurement area 1050. The light-emitting unit 1020 has a light-receiving sensor 1022 and a light-receiving optical system 1024. The light-receiving sensor 1022 has a plurality of pixels 1221 arranged in two dimensions. For example, in the case of a VGA light-receiving sensor 1022, 480×640 pixels 1221 are arranged in two dimensions. Each pixel 1221 has a light-receiving element, and the light-receiving element outputs a signal (light-receiving data) corresponding to the amount of light received. The light-receiving optical system 1024 is an optical system that enables the light-emitting unit 1020 to receive reflected light from the measurement area 1050. The light-receiving optical system 1024 forms an image of the measurement area 1050 on the light-receiving surface of the light-receiving sensor 1022. Each pixel 1221 of the light-receiving sensor 1022 is associated with a specified area of ​​the measurement area 1050 via the light-receiving optical system 1024. A certain pixel 1221 of the light receiving sensor 1022 receives light (reflected light and background light) from a corresponding area of ​​the measurement area 1050 via the light receiving optical system 1024. In addition, each pixel 1221 of the light receiving sensor 1022 is associated with a predetermined light emitting element 1121 of the light emitting unit 1012. Light emitted from a certain light emitting element 1121 is received by the corresponding pixel 1221 via the light projecting optical system 1014 and the light receiving optical system 1024. The light receiving optical system 1024 will be described later.

[0133] The control unit 1030 is responsible for controlling the measuring device 1001. The control unit 1030 controls the irradiation unit 1010 and controls the light irradiated from the irradiation unit 1010. In addition, the control unit 1030 measures the distance to the object 1090 in a TOF (Time offlight: time of flight) manner based on the output result of the light emitting unit 1020. The control unit 1030 has a computing device and a storage device, which are not shown in the figure. The computing device is, for example, a computing processing device composed of a CPU, a GPU, an MPU, an ASIC, etc. A part of the computing device can also be composed of an analog computing circuit. The storage device is composed of a main storage device and an auxiliary storage device, and is a device for storing programs and data. Various processes for measuring the distance to the object 1090 are performed by executing the program stored in the storage device by the computing device. Fig.14 Functional blocks of various processes are shown.

[0134] The control unit 1030 includes a setting unit 1032, a timing control unit 1034, and a distance measuring unit 1036. The setting unit 1032 performs various settings. The timing control unit 1034 controls the processing timing of each unit. For example, the timing control unit 1034 controls the timing of emitting light from the light emitting unit 1012. The distance measuring unit 1036 measures the distance to the object 1090. The distance measuring unit 1036 includes a signal processing unit 1362, a time detection unit 1364, and a distance calculation unit 1366. The signal processing unit 1362 processes the output signal (light receiving data) of the light receiving sensor 1022. The time detection unit 1364 detects the flight time of light (the time from the irradiation of light to the arrival of reflected light). The distance calculation unit 1366 calculates the distance to the object 1090.

[0135] Fig.16 This is a timing chart for explaining an example of a measurement method.

[0136] The control unit 1030 (timing control unit 1034 ) causes the light emitting unit 1012 of the irradiation unit 1010 to emit pulse light at a predetermined cycle. Fig.16 The upper side of shows the timing of emitting pulse light (measurement light) from the light emitting unit 1012. The light emitted from the light emitting unit 1012 is irradiated to the measurement area 1050 via the light projection optical system 1014. The light reflected from the surface of the object 1090 in the measurement area 1050 is received by the light receiving sensor 1022 via the light receiving optical system 1024. The pixel 1221 of the light receiving sensor 1022 receives the pulsed reflected light. Fig.16 The center of the shows the timing when the pulsed reflected light arrives. Fig.16 The lower side of shows pixel data S of a certain pixel 1221 of the light receiving sensor 1022 (light receiving data of a light receiving element of a certain pixel 1221 ). The pixel data S of the light receiving sensor 1022 is data indicating the amount of light received by the pixel 1221 .

[0137] The control unit 1030 (timing control unit 1034) may emit light from all the light emitting elements 1121 of the light emitting unit 1012 and irradiate the entire measurement region 1050 with light, or may emit light from a part of the light emitting elements 1121 of the light emitting unit 1012 (for example, one light emitting element 1121) and irradiate only a predetermined region of the measurement region 1050 with light. When light is emitted from a part of the light emitting elements 1121 of the light emitting unit 1012 (for example, one light emitting element 1121), the control unit 1030 (signal processing unit 1362) obtains the pixel data S of the pixel 1221 corresponding to the light emitting element 1121 that emits light.

[0138] The distance measuring unit 1036 (signal processing unit 1362) of the control unit 1030 detects the arrival timing of the reflected light based on the pixel data S of each pixel 1221. For example, the signal processing unit 1362 detects the arrival timing of the reflected light based on the timing of the peak of the pixel data S.

[0139] The distance measuring unit 1036 (time detecting unit 1364) detects the time Tf from the irradiation light to the arrival of the reflected light based on the emission timing of the light and the arrival timing of the light. The time Tf corresponds to the time for the light to go back and forth between the measuring device 1001 and the object 1090. Then, the distance measuring unit 1036 (distance calculating unit 1366) calculates the distance L to the object 1090 based on the time Tf. In addition, when the time from the irradiation light to the arrival of the reflected light is set to Tf and the speed of light is set to C, the distance L is L=C×Tf / 2. The control unit 1030 calculates the distance to the object 1090 for each pixel 1221 based on the time Tf detected for each pixel 1221 of the light emitting unit 1020, thereby generating a distance image.

[0140] <About the light emitting unit 1020>

[0141] Fig.17 and Fig.18 It is an explanatory diagram of the light emitting unit 1020 .

[0142] The light receiving optical system 1024 has a focusing lens 1241 and a bandpass filter BPF. The focusing lens 1241 is an optical element that forms an image of the measurement area 1050 on the light receiving surface of the light receiving sensor 1022. The bandpass filter BPF is a filter that allows light of a specific wavelength to pass through and cuts off (attenuates) light other than the specific wavelength. In the bandpass filter BPF, the transmittance of light of a specific wavelength is high, and the transmittance of light other than the specific wavelength is low (the attenuation rate of light other than the specific wavelength is high). In the following description, the wavelength band of light passing through the bandpass filter BPF is sometimes referred to as a "passband", and the wavelength band of light cut off (attenuated) by the bandpass filter BPF is sometimes referred to as a "cutoff band". For example, the passband is a wavelength band in which the transmittance of the bandpass filter BPF is 50% or more, and the cutoff band is a wavelength band in which the transmittance is less than 50%. The bandpass filter BPF needs to transmit the reflected light, and therefore can transmit at least the light of the wavelength emitted from the light emitting unit 1012 (with a high transmittance relative to the wavelength of the light emitted from the light emitting unit 1012). That is, the passband of the bandpass filter BPF needs to include at least the wavelength of the light emitted from the light emitting unit 1012. Since the light receiving optical system 1024 includes the bandpass filter BPF, it is possible to cut off the light of the cutoff band in the background light such as sunlight, and thus suppress the influence of interference caused by the background light.

[0143] On the other hand, the wavelength λ of the light emitted from the light emitting unit 1012 changes according to the temperature. For example, when the temperature of the light emitting unit 1012 rises, the wavelength λ of the light emitted from the light emitting unit 1012 becomes longer. Here, as an example, the light emitting unit 1012 emits light of wavelength λ1 (for example, λ1=940nm) when the temperature is T1 (for example, T1=25°C), and emits light of wavelength λ2 (for example, λ2=946nm) when the temperature is T2 (for example, T2=105°C). That is, the light emitting unit 1012 emits light of wavelength λ corresponding to the temperature in the wavelength band range of λ1 to λ2 within the operating temperature range of T1 to T2.

[0144] The bandpass filter BPF needs to transmit the light irradiated from the light emitting section 1012 with high transmittance. Assuming that the passband of the bandpass filter BPF is constant and independent of temperature, it is required to have high transmittance with respect to the entire wavelength band (λ1 to λ2) of the light emitted from the light emitting section 1012 within the range of operating temperature T1 to T2. That is, it is necessary to expand the passband of the bandpass filter BPF to include the entire wavelength band (range of λ1 to λ2) of the light emitted from the light emitting section 1012. However, as a result of the expansion of the passband of the bandpass filter BPF, the background light (the light of the passband in the background light) passing through the bandpass filter BPF increases. Therefore, when the passband of the bandpass filter BPF is constant and independent of temperature, the interference contained in the pixel data S (data representing the amount of light received by the pixel 1221) increases.

[0145] Therefore, in this embodiment, the wavelength of light that can pass through the bandpass filter BPF changes according to temperature. In other words, the bandpass filter BPF of this embodiment changes its characteristics according to temperature (the bandpass filter BPF has temperature dependence). This point will be described below.

[0146] Fig.19 1 is a schematic diagram showing the characteristics of the bandpass filter BPF of the present embodiment. The horizontal axis of the graph in the figure represents the wavelength (unit: nm), and the vertical axis represents the transmittance (unit: %). The two graphs in the figure represent the relationship between the wavelength and the transmittance of the bandpass filter BPF at two different temperatures. The thick line in the figure is a graph showing the characteristics of the bandpass filter BPF at temperature T11. The thin line in the figure is a graph showing the characteristics of the bandpass filter BPF at temperature T12 (>T11).

[0147] As shown in the figure, the passband of the bandpass filter BPF (the wavelength band of light passing through the bandpass filter BPF) changes according to the temperature. Here, when the temperature rises, the wavelength of the passband of the bandpass filter BPF becomes longer. That is, when the temperature of the passband of the bandpass filter BPF becomes higher, the curve graph shifts to the right side (long wavelength side) in the figure. In the figure, the center wavelength (peak wavelength at which the transmittance is the peak) of the passband of the bandpass filter BPF when the temperature is T11 is λ11, while, on the other hand, the center wavelength of the passband of the bandpass filter BPF when the temperature is T12 (>T12) is λ12 (>λ12). The transmittance of the bandpass filter BPF with respect to the wavelength λ11 is higher when the temperature is T11 than when the temperature is T12 (>T11). In addition, the transmittance of the bandpass filter BPF with respect to the wavelength λ12 is higher when the temperature is T12 (>T11) than when the temperature is T11.

[0148] Fig.19 The temperature T11 is set to the same level as the aforementioned temperature T1 (for example, T1 = 25°C), and λ11 is set to the same level as the aforementioned wavelength λ1 (for example, λ1 = 940nm). In addition, the temperature T12 is set to the same level as the aforementioned temperature T2 (for example, T2 = 105°C), and λ11 is set to the same level as the aforementioned λ2 (for example, λ2 = 946nm). Thus, when the temperature is T1 (for example, T1 = 25°C) and the light emitting unit 1012 emits light of wavelength λ1 (for example, λ1 = 940nm), the transmittance of the bandpass filter BPF with respect to the wavelength λ1 becomes high, and the reflected light of wavelength λ1 easily passes through the bandpass filter BPF. In addition, when the temperature is T2 (for example, T2 = 105°C) and the light emitting unit 1012 emits light of wavelength λ2 (for example, λ2 = 946nm), the transmittance of the bandpass filter BPF with respect to wavelength λ2 becomes high, and the reflected light of wavelength λ2 easily passes through the bandpass filter BPF. In addition, the structure of the bandpass filter BPF for setting the center wavelength (peak wavelength) of the passband of the bandpass filter BPF at temperature T1 (≈T11) to λ1 and setting the center wavelength (peak wavelength) of the passband of the bandpass filter BPF at temperature T2 (≈T12) to λ2 will be described later.

[0149] As described above, if the temperature of the light emitting unit 1012 rises, the wavelength λ of the light emitted from the light emitting unit 1012 becomes longer, so in this embodiment, a bandpass filter BPF is used in which the wavelength (central wavelength) that becomes the peak value of the transmittance becomes longer when the temperature rises. Thus, even if the wavelength λ of the light emitted from the light emitting unit 1012 changes according to the temperature, the transmittance of the bandpass filter BPF with respect to the wavelength λ becomes higher, and the transmittance of the bandpass filter BPF with respect to wavelengths other than the wavelength becomes lower. As a result, the influence of the noise included in the pixel data S can be reduced, and the SN ratio is improved.

[0150] <Structure of Band Pass Filter BPF>

[0151] Fig. 20 and Fig.21 It is an enlarged explanatory diagram of the structure of the band pass filter BPF. Fig. 20 It is a top view of the bandpass filter BPF. Fig.21 is a cross-sectional view of the bandpass filter BPF. Fig. 20 Only seven protrusions 1027 are depicted, but on the surface of the bandpass filter BPF, Fig. 20 The configuration pattern shown is configured with numerous protrusions 1027 .

[0152] The band pass filter BPF is composed of a substrate 1025 and a thin film 1026 .

[0153] The substrate 1025 is made of a light-transmitting component. For example, the substrate 1025 is made of a glass substrate (here, organic glass). A thin film 1026 is formed on the surface of the substrate 1025. For example, the substrate 1025 is made of a light-transmitting resin (resin with high transmittance), and here, the substrate 1025 is made of PMMA (Poly Methyl Methacrylate). However, the substrate 1025 may also be made of other organic glasses. In addition, here, the substrate 1025 is made of a material having a larger linear expansion coefficient than the film 1026. However, the substrate 1025 may have a linear expansion coefficient equal to that of the film 1026, or may not have a linear expansion coefficient larger than that of the film 1026.

[0154] The thin film 1026 is formed on the surface of the substrate 1025. In addition, the thin film 1026 is made of a material having a different refractive index from that of the substrate 1025. For example, the thin film 1026 is made of a material with a high refractive index, so that the refractive index n2 of the thin film 1026 is higher (larger) than the refractive index n1 of the substrate 1025. Here, the thin film 1026 is made of titanium oxide (TiO2). However, the thin film 1026 is not limited to titanium oxide (TiO2), and may be made of amorphous silicon (α-Si), for example. In addition, here, the thin film 1026 is made of a material (inorganic material) having a smaller linear expansion coefficient than that of the substrate 1025. However, the thin film 1026 may have a linear expansion coefficient that is the same as that of the substrate 1025, or may not be a material having a smaller linear expansion coefficient than that of the substrate 1025.

[0155] A plurality of protrusions 1027 are provided on the surface of the film 1026. The protrusions 1027 on the surface of the film 1026 are microscopic structures smaller than the wavelength of light, and are sometimes referred to as nanopillars. The protrusions 1027 are configured in a columnar shape. Here, the protrusions 1027 are configured in a cylindrical shape. However, the protrusions 1027 may also be configured in a prism shape (e.g., a hexagonal prism shape, an octagonal prism shape, etc.). The plurality of protrusions 1027 are arranged in a predetermined pattern. Here, as Fig. 20 As shown, the columnar protrusions 1027 are arranged in a lattice. In other words, a nanocolumn array is formed on the surface of the film 1026. By arranging the plurality of protrusions 1027 in a lattice, the protrusions 1027 can be arranged at a predetermined interval. In addition, by arranging the columnar protrusions 1027 in a lattice, the polarization dependence of the bandpass filter BPF can be reduced. In addition, as Fig. 20 As shown, by arranging the plurality of protrusions 1027 in a triangular lattice (equilateral triangular lattice), each protrusion 1027 can be arranged at a high density in a manner equal to the intervals between the surrounding six protrusions 1027. In addition, the arrangement pattern of the protrusions 1027 is not limited to Fig. 20 For example, the plurality of protrusions 1027 may be arranged in a hexagonal lattice with equal spacing to the surrounding three protrusions 1027. The protrusions 1027 are made of the same material as the thin film 1026, and are made of titanium oxide (TiO2) in this case.

[0156] By configuring the protrusions 1027 smaller than the wavelength of the light in a prescribed pattern, the phase and direction of the light are controlled, and the wavelengths that reinforce each other (or the wavelengths that weaken each other) are controlled. In the present embodiment, the substrate 1025 and the film 1026 (and the protrusions 1027) expand and contract according to temperature changes, so the spacing between the protrusions 1027 changes according to the temperature (the density of the protrusions 1027 changes). Thus, according to the temperature, the wavelength of the light that can pass through the bandpass filter BPF changes, and the center wavelength of the passband of the bandpass filter BPF changes. In the present embodiment, when the temperature rises, the spacing between the protrusions 1027 expands, so the center wavelength of the passband of the bandpass filter BPF becomes longer (shifted to the long wavelength side). Therefore, when the temperature rises, the passband of the bandpass filter BPF can be changed in a manner that adapts to the lengthening of the wavelength λ of the light emitted from the light-emitting portion 1012. In addition, the shape of the protrusion 1027 (the height and diameter of the cylinder) also changes according to the temperature, and even if the wavelength of light that can pass through the bandpass filter BPF changes due to this influence, the center wavelength of the passband of the bandpass filter BPF changes. In this embodiment, by adjusting the intervals between the protrusions 1027, the characteristics (temperature dependence) of the bandpass filter BPF can be adjusted. In addition, by adjusting the height and diameter of the protrusion 1027, the characteristics of the bandpass filter BPF (the wavelength of the passband and the cutoff band, etc.) can be adjusted.

[0157] In addition, in the present embodiment, the thin film 1026 having the protrusions 1027 is formed on the substrate 1025 having a large linear expansion coefficient. Thus, even if the linear expansion coefficient of the protrusions 1027 (thin film 1026) is small, the change in the interval between the protrusions 1027 according to the temperature can be increased. However, the linear expansion coefficient of the substrate 1025 may not be greater than the linear expansion coefficient of the thin film 1026 (and the protrusions 1027), and for example, the linear expansion coefficient of the substrate 1025 may be of the same degree as the linear expansion coefficient of the thin film 1026 (and the protrusions 1027).

[0158] Fig. 22 It is a graph showing the characteristics of the bandpass filter BPF. The thick line in the figure is a graph showing the characteristics of the bandpass filter BPF when the temperature is 25°C (equivalent to the aforementioned T1 and T11). The thin line in the figure is a graph showing the characteristics of the bandpass filter BPF when the temperature is 105°C (equivalent to the aforementioned T2 and T12).

[0159] exist Fig. 22 In the bandpass filter BPF shown in the figure, the substrate 1025 is made of PMMA (Poly Methyl Methacrylate) and the film 1026 (and the protrusion 1027) is made of titanium oxide (TiO2). The linear expansion coefficient of the substrate 1025 is 56×10 －6 / ℃, the linear expansion coefficient of film 1026 is 10×10 －6 / °C. In addition, the refractive index of the substrate 1025 is 1.49, and the refractive index of the film 1026 is 2.5. The thickness of the film 1026 is 146nm. Fig. 20 In the pattern arrangement shown, the interval between the protrusions 1027 is 557 nm. In addition, the radius of the cylindrical protrusion 1027 is 185 nm, and the height of the protrusion 1027 is 145 nm.

[0160] Fig. 22 The transmittance of the bandpass filter BPF shown becomes higher at 25°C with respect to 940nm (equivalent to the aforementioned λ1, λ11). The light-emitting portion 1012 of this embodiment emits light with a wavelength of 940nm at 25°C, so the bandpass filter BPF easily transmits reflected light. In addition, the transmittance of the bandpass filter BPF becomes higher at 105°C with respect to 946nm (equivalent to the aforementioned λ2, λ12). The light-emitting portion 1012 of this embodiment emits light with a wavelength of 946nm at 105°C, so the bandpass filter BPF easily transmits reflected light.

[0161] In addition, it is assumed here that the light emitting section 1012 emits light of a wavelength of 940 nm at 25° C. and emits light of a wavelength of 946 nm at 105° C. However, the temperature characteristics of the light emitting section 1012 may differ depending on the structure of the light emitting section 1012. In this case, the arrangement (interval of the protrusions 1027) and shape (height, diameter) of the protrusions 1027 of the band pass filter BPF are changed according to the temperature characteristics of the light emitting section 1012 (in addition, the materials of the substrate 1025 and the film 1026 may also be changed).

[0162] Fig.23 : is a graph showing another characteristic of the band pass filter BPF. In addition, it is assumed here that the light emitting unit 1012 emits light with a wavelength of 1298 nm at 25°C and emits light with a wavelength of 1308 nm at 105°C.

[0163] exist Fig.23 In the bandpass filter BPF shown, the linear expansion coefficient of the substrate 1025 is 56×10 －6 / ℃, the linear expansion coefficient of film 1026 is 10×10 －6 / °C. In addition, the refractive index of the substrate 1025 is 1.49, and the refractive index of the film 1026 is 3.48. The thickness of the film 1026 is 270nm. Fig. 20 In the pattern arrangement shown, the interval between the protrusions 1027 is 860 nm. In addition, the diameter of the cylindrical protrusion 1027 is 210 nm (radius is 105 nm), and the height of the protrusion 1027 is 160 nm.

[0164] Fig.23 The transmittance of the bandpass filter BPF shown in FIG. 1 is higher at 25° C. with respect to 1298 nm (equivalent to the aforementioned λ1 and λ11). In addition, the transmittance of the bandpass filter BPF is higher at 105° C. with respect to 1308 nm (equivalent to the aforementioned λ2 and λ12). In this way, by appropriately changing the shape and arrangement of the protrusion 1027 of the bandpass filter BPF, a bandpass filter BPF that adapts to the temperature characteristics of the light-emitting unit 1012 can be manufactured.

[0165] In addition, the protrusions 1027 are configured as columns (cylindrical or prism-shaped), but the shape of the protrusions 1027 is not limited to columns. For example, the protrusions 1027 may also be configured as convex strips (strip-shaped convex portions). In this case, a plurality of protrusions 1027 are arranged at predetermined intervals in a predetermined direction on the surface of the film 1026. The bandpass filter BPF in which the protrusions 1027 of the convex strips are arranged in a predetermined direction is different from the bandpass filter BPF in which the columnar protrusions 1027 are arranged in a lattice shape (see Fig. 20), the polarization dependence of the bandpass filter BPF becomes stronger. Therefore, it is preferred that the bandpass filter BPF in which the protrusions 1027 of the convex strips are arranged in a specified direction is used to pass or cut off light vibrating in a specific direction. In addition, even if the protrusions 1027 are configured as convex strips, by adjusting the intervals between the protrusions 1027 (the intervals between the convex strips) or the shapes of the protrusions 1027 (the height and width of the convex strips), the characteristics of the bandpass filter BPF (the wavelengths of the passband and the cutoff band, etc.) can be adjusted.

[0166] Fig.24 It is an explanatory diagram of a modified example of the arrangement of the bandpass filter BPF.

[0167] In the modified example, the bandpass filter BPF is arranged between the condenser lens 1241 and the light receiving sensor 1022. By arranging the bandpass filter BPF on the rear side of the condenser lens 1241 (the side opposite to the object 1090 when viewed from the condenser lens 1241), the influence of the angle dependence of the bandpass filter BPF can be suppressed (in other words, the angle of the light incident on the bandpass filter BPF can be suppressed). In addition, when the bandpass filter BPF is arranged on the front side of the condenser lens 1241 (the side of the object 1090), the light enters the bandpass filter BPF from a wider angle, and is therefore easily affected by the angle dependence of the bandpass filter BPF. In the case where the bandpass filter BPF is configured in a manner such that the transmittance changes according to the temperature as in the present embodiment, the angle dependence of the bandpass filter BPF can be strengthened, so it is particularly effective to arrange the bandpass filter BPF between the condenser lens 1241 and the light receiving sensor 1022 as in the modified example.

[0168] Figure 25 to Figure 27 It is an explanatory diagram of the configuration of another band pass filter BPF'.

[0169] When the bandpass filter BPF is configured in such a manner that the transmittance varies according to the temperature as in the present embodiment, the cutoff band of the bandpass filter BPF can be narrowed. Therefore, the light receiving optical system 1024 preferably further includes a bandpass filter BPF' different from the aforementioned bandpass filter BPF. Another bandpass filter BPF' allows light of the wavelength band irradiated by the light emitting unit 1012 to pass through, and cuts off (attenuates) light outside the wavelength band. For example, when the light emitting unit 1012 emits light of a wavelength λ corresponding to the temperature in the wavelength band of λ1 to λ2 within the operating temperature range, the other bandpass filter BPF' allows light of the wavelength band of λ1 to λ2 to pass through, and attenuates light of the wavelength band smaller than λ1 and the wavelength band larger than λ2. Thus, even if the cutoff band of the bandpass filter BPF whose passband varies according to the temperature is narrow, background light such as sunlight can be cut off by the other bandpass filter BPF', thereby suppressing the influence of interference caused by the background light.

[0170] The other bandpass filter BPF′ may be arranged on the front side (the object 1090 side) of the bandpass filter BPF, or on the rear side (the side opposite to the object 1090 when viewed from the bandpass filter BPF) of the bandpass filter BPF. Figure 25 to Figure 27 As shown in FIG. 1 , when the other band-pass filter BPF′ is arranged on the front side (the object 1090 side) of the band-pass filter BPF, only the light that has passed through the other band-pass filter BPF′ can be incident on the band-pass filter BPF, and the light of the wavelength cut off by the other band-pass filter BPF′ is not incident on the band-pass filter BPF. In addition, when the band-pass filter BPF is arranged between the focusing lens 1241 and the light receiving sensor 1022, the other band-pass filter BPF′ can be as shown in FIG. Fig.26 As shown in FIG. 1 , the condenser lens 1241 may be arranged at a position closer to the front side (the side of the object 1090) than the condenser lens 1241. Fig. 27 As shown in FIG. 1 , the optical filter 1090 is arranged on the rear side of the condenser lens 1241 (the side opposite to the object 1090 when viewed from the condenser lens 1241; here, between the condenser lens 1241 and the bandpass filter BPF). Fig. 27 When another band pass filter BPF' is arranged as shown, the influence of the angle dependency of the band pass filter BPF' can be suppressed.

[0171] ===Conclusion===

[0172] The measuring device 1001 of this embodiment includes a light emitting unit 1012, a band pass filter BPF, and a light receiving sensor 1022. The light emitting unit 1012 emits light of a wavelength corresponding to the temperature. The band pass filter BPF allows reflected light of the light irradiated from the light emitting unit 1012 to pass through. The light receiving sensor 1022 receives the light that has passed through the band pass filter BPF. In this embodiment, the wavelength of light that can pass through the band pass filter BPF is changed according to the temperature. According to such a structure, even if light of a wavelength corresponding to the temperature is irradiated from the light emitting unit 1012, the band pass filter BPF can pass the light, and the light receiving sensor 1022 can reduce the background light received by the light receiving sensor 1022 that receives the reflected light, and the influence of interference caused by the background light can be suppressed.

[0173] In addition, in this embodiment, the band pass filter BPF includes a substrate 1025 and a thin film 1026 formed on the substrate 1025. A plurality of protrusions 1027 are arranged in a predetermined pattern on the surface of the thin film 1026, and the intervals between the protrusions 1027 vary according to the temperature. Thus, the characteristics of the band pass filter BPF can be varied according to the temperature.

[0174] In the present embodiment, the linear expansion coefficient of the substrate 1025 is larger than the linear expansion coefficient of the film 1026. Thus, even if the linear expansion coefficient of the film 1026 is small, the change in the interval between the protrusions 1027 according to the temperature can be increased.

[0175] In this embodiment, the base material 1025 is made of a light-transmitting resin, so that the linear expansion coefficient of the base material 1025 can be easily made larger than the linear expansion coefficient of the film 1026 .

[0176] In addition, in the present embodiment, the protrusions 1027 are configured in a columnar shape, and a plurality of protrusions 1027 are arranged in a lattice shape. This can reduce the polarization dependency of the band pass filter BPF.

[0177] On the other hand, the protrusion 1027 may be formed as a convex strip, and a plurality of convex strips may be arranged in a predetermined direction to form a bandpass filter BPF whose characteristics change according to temperature. Thus, the bandpass filter BPF can be formed in a manner that allows light vibrating in a specific direction to pass or cut off.

[0178] In addition, if Fig.24 As shown in FIG. 1 , the band pass filter BPF is preferably disposed between the condenser lens 1241 and the light receiving sensor 1022. This can suppress the influence of the angle dependency of the band pass filter BPF.

[0179] In addition, it is preferable to further include another bandpass filter BPF that passes light of the wavelength band irradiated by the light emitting unit 1012. Thus, even if the cutoff frequency band of the bandpass filter BPF whose passband changes according to temperature is narrow, the background light such as sunlight can be cut off by using another bandpass filter BPF', thereby suppressing the influence of interference caused by the background light.

[0180] In addition, the bandpass filter BPF of this embodiment includes a substrate 1025 and a thin film 1026 formed on the substrate 1025. A plurality of protrusions 1027 are arranged in a predetermined pattern on the surface of the thin film 1026, and the intervals between the protrusions 1027 vary according to the temperature. Thus, a bandpass filter whose characteristics vary according to the temperature can be realized.

[0181] [Third Embodiment]

[0182] <Overall structure>

[0183] Fig.28 It is an explanatory diagram of the overall structure of the measuring device 2001. Fig.29 It is a schematic diagram for explaining the measuring device 2001.

[0184] In the following description, Fig.29The directions are determined as shown. The Z direction is a direction along the optical axis of the projection optical system 2014. In addition, the object 2090 to be measured by the measuring device 2001 is separated from the measuring device 2001 in the Z direction. In addition, the X direction and the Y direction are directions perpendicular to the Z direction. In addition, the plurality of light emitting elements 2121 constituting the light emitting unit 2012 are arranged two-dimensionally along the X direction and the Y direction (described later; refer to Figure 31 to Figure 33 ). The plurality of pixels 2221 of the light emitting unit 2020 are also arranged two-dimensionally along the X direction and the Y direction.

[0185] The measuring device 2001 is a device for measuring the distance to the object 2090. The measuring device 2001 is a device having a function as a so-called LiDAR (Light Detection and Ranging). The measuring device 2001 emits measuring light, detects reflected light reflected from the surface of the object 2090, and measures the time from the emission of the measuring light to the reception of the reflected light, thereby measuring the distance to the object 2090 using the TOF method (Time of Flight). The measuring device 2001 includes an irradiation unit 2010, a light emitting unit 2020, and a control unit 2030.

[0186] The irradiation unit 2010 is an irradiation device that irradiates the measurement light to the object 2090. The irradiation unit 2010 irradiates the measurement area 2050 (see Fig.29 ) irradiates the measuring light. The irradiation unit 2010 includes a light emitting unit 2012 and an optical system 2014 for projecting light. The light emitting unit 2012 is a component (light source) that emits light. For example, the light emitting unit 2012 is composed of a vertical surface emitting laser (VCSEL) array chip. The optical system 2014 for projecting light is an optical system that irradiates the light emitted from the light emitting unit 2012 to the measuring area 2050. The detailed structure of the irradiation unit 2010 will be described later.

[0187] The light emitting unit 2020 receives reflected light from the object 2090. The light emitting unit 2020 receives reflected light from the measurement area 2050 (see Fig.29) of the measurement area 2050. The light emitting unit 2020 includes a light receiving sensor 2022 and a light receiving optical system 2024. The light receiving sensor 2022 includes a plurality of pixels 2221 arranged two-dimensionally. For example, in the case of a VGA light receiving sensor 2022, 480×640 pixels 2221 are arranged two-dimensionally. Each pixel 2221 includes a light receiving element, and the light receiving element outputs a signal corresponding to the amount of light received. The light receiving optical system 2024 is an optical system that enables the light emitting unit 2020 to receive reflected light from the measurement area 2050. The light receiving optical system 2024 forms an image of the measurement area 2050 on the light receiving surface of the light receiving sensor 2022.

[0188] The control unit 2030 is responsible for controlling the measuring device 2001. The control unit 2030 controls the irradiation unit 2010 and controls the light irradiated from the irradiation unit 2010. In addition, the control unit 2030 measures the distance to the object 2090 in a TOF (Time offlight: time of flight) manner based on the output result of the light emitting unit 2020. The control unit 2030 has a computing device and a storage device not shown in the figure. The computing device is, for example, a computing processing device such as a CPU and a GPU. A part of the computing device can also be composed of an analog computing circuit. The storage device is a device composed of a main storage device and an auxiliary storage device and stores programs and data. By executing the program stored in the storage device by the computing device, various processes for measuring the distance to the object 2090 are performed. Fig.28 Functional blocks of various processes are shown.

[0189] The control unit 2030 includes a setting unit 2032, a timing control unit 2034, and a distance measuring unit 2036. The setting unit 2032 performs various settings. The timing control unit 2034 controls the processing timing of each unit. For example, the timing control unit 2034 controls the timing of emitting light from the light emitting unit 2012. The distance measuring unit 2036 measures the distance to the object 2090. The distance measuring unit 2036 includes a signal processing unit 2362, a time detection unit 2364, and a distance calculation unit 2366. The signal processing unit 2362 processes the output signal of the light receiving sensor 2022. The time detection unit 2364 detects the flight time of light (the time from the irradiation of light to the arrival of reflected light). The distance calculation unit 2366 calculates the distance to the object 2090.

[0190] Fig.30 This is a timing chart for explaining an example of a measurement method.

[0191] The control unit 2030 (timing control unit 2034 ) causes the light emitting unit 2012 of the irradiation unit 2010 to emit pulse light at a predetermined cycle. Fig.30The upper side of represents the timing (emission timing) of the light emitting unit 2012 emitting pulsed light. The light emitted from the light emitting unit 2012 is irradiated to the measurement area 2050 via the light projection optical system 2014. The light reflected from the surface of the object 2090 in the measurement area 2050 is received by the light receiving sensor 2022 via the light receiving optical system 2024. Each pixel 2221 of the light receiving sensor 2022 receives the pulsed reflected light. Fig.30 The center of shows the timing when the pulsed reflected light arrives (arrival timing). Fig.30 The lower side of shows an output signal of a certain pixel 2221 of the light receiving sensor 2022. Each pixel 2221 of the light receiving sensor 2022 outputs a signal according to the amount of received light.

[0192] The control unit 2030 (timing control unit 2034) may emit light from all the light emitting elements 2121 of the light emitting unit 2012 and irradiate the entire measurement region 2050 with light, or may emit light from a part of the light emitting elements 2121 of the light emitting unit 2012 (for example, one light emitting element 2121) and irradiate only a predetermined region of the measurement region 2050 with light. When light is emitted from a part of the light emitting elements 2121 of the light emitting unit 2012 (for example, one light emitting element 2121), the control unit 2030 obtains a signal output from a pixel 2221 corresponding to the light emitting unit 2012 that emits light (the signal of the pixel 2221 that does not correspond to the light emitting unit 2012 that emits light is not processed). The irradiation unit 2010 of this embodiment can emit light from a part of the light emitting elements 2121 of the light emitting unit 2012 (for example, one light emitting element 2121) and irradiate a predetermined region (corresponding to the irradiation spot group described later) of the measurement region 2050 with light.

[0193] The distance measuring unit 2036 (signal processing unit 2362) of the control unit 2030 detects the arrival timing of the reflected light based on the output signal of each pixel 2221. For example, the signal processing unit 2362 detects the arrival timing of the reflected light based on the timing of the peak value of the output signal of each pixel 2221. In addition, in order to remove the influence of interfering light (such as sunlight), the signal processing unit 2362 may also obtain the arrival timing of the reflected light based on the peak value of the signal after the DC component of the output signal of the pixel 2221 is cut off.

[0194] The distance measuring unit 2036 (time detecting unit 2364) detects the time Tf from the irradiated light to the arrival of the reflected light based on the emission timing of the light and the arrival timing of the light. The time Tf corresponds to the time for the light to go back and forth between the measuring device 2001 and the object 2090. Then, the distance measuring unit 2036 (distance calculating unit 2366) calculates the distance L to the object 2090 based on the time Tf. In addition, when the time from the irradiated light to the arrival of the reflected light is set to Tf and the speed of light is set to C, the distance L is L=C×Tf / 2. The control unit 2030 calculates the distance to the object 2090 for each pixel 2221 based on the time Tf detected for each pixel 2221 of the light emitting unit 2020, thereby generating a distance image.

[0195] <About the Irradiation Department 2010>

[0196] Fig.31 The diagram is an explanatory diagram of the arrangement of the light emitting elements 2121 of the light emitting unit 2012 .

[0197] The light emitting unit 2012 is composed of, for example, a surface emitting laser (VCSEL) array chip. The light emitting unit 2012 has a plurality of light emitting elements 2121 (e.g., surface emitting laser; VCSEL), and the plurality of light emitting elements 2121 are arranged two-dimensionally. The plurality of light emitting elements 2121 are arranged at intervals in the X direction and the Y direction. In this way, when the VCSELs serving as the light emitting elements 2121 are arranged two-dimensionally, the plurality of light emitting elements 2121 are arranged at intervals by the gaps between the emitters. In the figure, three light emitting elements 2121 are arranged in the X direction and three in the Y direction, respectively, but in reality, more than three light emitting elements 2121 are arranged along the X direction and the Y direction.

[0198] Fig.32 2121 (one light emitting element 2121) is a reference diagram for explaining light irradiating the measurement region 2050. One circle in the diagram indicates a range in which light emitted from a certain light emitting element 2121 (one light emitting element 2121) irradiates the measurement region 2050 via one lens. One circle in the diagram corresponds to an image of a light emitting point of one light emitting element 2121.

[0199] like Fig.31 As shown in FIG. 1 , when a plurality of light emitting elements 2121 are arranged at intervals, if the light projection optical system 2014 directly projects the image of the light emitting point of the light emitting element 2121 onto the measurement area 2050, as shown in FIG. Fig.32 As shown, there may be a gap in the light irradiated to the measurement region 2050. As a result, an area where the light cannot be irradiated is generated in the measurement region 2050, and an area where the measurement cannot be performed is generated in the measurement region 2050.

[0200] Fig.33 This is an explanatory diagram of light irradiated to the measurement region 2050 according to this embodiment.

[0201] The light projection optical system 2014 of this embodiment has a plurality of lenses that shift the optical axis in a predetermined direction (X direction and Y direction). Fig.33 As shown, the occurrence of a region where light cannot be irradiated is suppressed in the measurement region 2050. This point will be described below.

[0202] Fig.34 It is an explanatory diagram of the lens unit 2015 .

[0203] The optical system 2014 for projection light has a lens unit 2015 having a plurality of lens elements. In this embodiment, the lens element is composed of a super lens 2016, and the lens unit 2015 has a plurality of super lenses 2016 (the optical system 2014 for projection light has a plurality of super lenses 2016). The super lens 2016 is an optical element that changes the transmission intensity and phase of light by arranging micro structures smaller than the wavelength of light in a predetermined pattern and functions as a lens (a convex lens in this case).

[0204] The figure shows a configuration pattern of microstructures composed of a plurality of superlenses 2016. The microstructures that constitute the superlens 2016 are arranged on a plane (XY plane) parallel to the X direction and the Y direction. The superlens 2016 of this embodiment is composed of microstructures arranged on the surface of a substrate (e.g., a glass substrate). That is, the superlens 2016 of this embodiment is composed of a supersurface. However, the superlens 2016 is not limited to a supersurface, and may also be composed of a metamaterial with microstructures arranged in three dimensions.

[0205] In the lens unit 2015, a plurality of super lenses 2016 are arranged along the X direction and the Y direction, respectively. In the figure, two super lenses 2016 are arranged along the X direction, and two super lenses 2016 are arranged along the Y direction. However, the number of super lenses 2016 arranged in the X direction or the Y direction may be two or more.

[0206] The plurality of super lenses 2016 are arranged with their optical axes shifted in the X direction and the Y direction. The figure shows a case where the super lenses 2016 are arranged at intervals t in the X direction and the Y direction. The optical axis of each super lens 2016 is parallel to the Z direction.

[0207] In this embodiment, a plurality of super lenses 2016 are arranged on a common plane by arranging microstructures on a common plane (e.g., on the same glass substrate). In addition, assuming that a plurality of convex lenses are arranged in two dimensions, the convex lenses are shaped in which the thickness varies according to the distance from the optical axis, and therefore strip-shaped recesses are formed at the boundaries of adjacent convex lenses, and shadows may be formed in the measurement area 2050 due to the influence of the strip-shaped recesses. In contrast, in the case where a plurality of super lenses 2016 are provided on a common plane as in this embodiment, the boundaries of the lenses can be made flat, and thus shadows can be prevented from being formed in the measurement area 2050. In addition, by using the super lens 2016, the diameter of the lens can be set smaller, or the offset of the optical axis of the lens can be set smaller. For example, the distance t between the optical axes in the figure can be set smaller.

[0208] Fig.35 This is an illustration of an image of a light emitting point of a light emitting element 2121 formed by a super lens 2016. The circle in the figure indicates the range of light irradiated by a certain light emitting element 2121 (a light emitting element 2121) to a measurement area 2050 via a certain super lens 2016 (a super lens 2016). In the following description, the range (equivalent to the range of a circle in the figure) of light irradiated by a certain light emitting element 2121 (a light emitting element 2121) to a measurement area 2050 via a certain super lens 2016 (a super lens 2016) is referred to as an "irradiation spot". Fig.35 As shown, the light emission point of one light emitting element 2121 forms one image (irradiation spot) in the measurement area 2050 via one super lens 2016 .

[0209] Fig.36 2016 is an explanatory diagram of an image of a light emitting point of a light emitting element 2121 formed by a plurality of super lenses 2016. Fig.36 As shown in FIG. 1 , the light emitting point of one light emitting element 2121 forms multiple images (irradiation spots) in the measurement area 2050 via multiple super lenses 2016. In the following description, multiple images (irradiation spots) formed by a certain light emitting element 2121 (one light emitting element 2121) via multiple super lenses 2016 are referred to as an irradiation spot group. Fig.34As shown in FIG. 1 , when two super lenses 2016 are arranged in the X direction and two super lenses 2016 are arranged in the Y direction, the light emitting point of a certain light emitting element 2121 forms a plurality of images (irradiation spot group) arranged two in the X direction and two in the Y direction on the measurement region 2050. That is, the irradiation spot group in this case is composed of a plurality of irradiation spots arranged in 2×2. In addition, when a plurality of super lenses 2016 are arranged in N numbers in the X direction and N numbers in the Y direction, a certain light emitting element 2121 (one light emitting element 2121) forms an image (irradiation spot group) arranged N numbers in the X direction and N numbers in the Y direction on the measurement region 2050. That is, the irradiation spot group in this case is composed of a plurality of irradiation spots arranged in N×N.

[0210] like Fig.36 As shown, two irradiation spots adjacent in the X direction and the Y direction (two images of the light emitting point of a certain light emitting element 2121 formed by two super lenses 2016 adjacent in a predetermined direction) partially overlap. By overlapping adjacent irradiation spots, it is possible to suppress the formation of a gap between the two adjacent irradiation spots, and it is possible to suppress the generation of an area that cannot be irradiated with light on the measurement area 2050.

[0211] Fig.38 This is an explanatory diagram of optical conditions for making two irradiation spots (images of light-emitting points of a certain light-emitting element 2121 formed by two super lenses 2016 adjacent to each other in a predetermined direction) overlap partially. The figure depicts a situation where two irradiation spots belonging to the same irradiation spot group overlap partially.

[0212] S1 in the figure represents the light-emitting point of a certain light-emitting element 2121 (for the purpose of explanation, the light-emitting point is drawn in a direction perpendicular to the paper, but the light-emitting point is perpendicular to the Z direction). In addition, L1 and L2 in the figure represent two super lenses 2016 adjacent to each other in a specified direction (X direction or Y direction) (for the purpose of explanation, the super lens is drawn as a convex lens shape). In the following description, these two super lenses are sometimes referred to as the first super lens L1 and the second super lens L2. I in the figure represents the image (irradiation spot) formed in the measurement area 2050 via the super lens 2016 (for the purpose of explanation, the image is drawn in a direction perpendicular to the paper, but the image is perpendicular to the Z direction). In the following description, the image (irradiation spot) of the light-emitting point S1 of the first super lens L1 is sometimes referred to as image I 11 The image (irradiation spot) of the light emitting point S1 of the first super lens L2 is called image I 12 .

[0213] Here, let the focal length of the super lens 2016 be f, let the diameter of the light emitting point of the light emitting element 2121 be D, and let the interval (distance between optical axes) of the super lenses 2016 arranged in a predetermined direction (X direction or Y direction) be t.

[0214] θ1 in the figure is the distance between the center of the first super lens L1 and the image I 11 The line connecting the center of the first super lens L1 and the image I 11 The upper end (adjacent image I 12 In addition, the center of the first super lens L1 and the image I 11 The line connecting the center of the light emitting point S1 and the center of the first super lens L1 (the dot-dashed line in the figure) is located on the extension line of the line connecting the center of the light emitting point S1 and the center of the first super lens L1. 11 The line connecting the upper ends of is located on the extension line of the line connecting the lower end of the light emitting point S1 and the center of the first super lens L1. The angle θ1 is equivalent to half of the viewing angle of the irradiation spot. The angle θ1 can be expressed as follows.

[0215] [Formula 2]

[0216]

[0217] In addition, θ2 in the figure is the distance between the center of the first super lens L1 and the image I 11 The line connecting the center of the second metalens L2 and the image I (the dot-dash line in the figure) 12 The lower end (adjacent image I 11 In addition, the center of the second super lens L2 and the image I 12 The line connecting the lower ends of is located on the extension line of the line connecting the upper end of the light-emitting point S1 and the center of the second super lens L2. The angle θ2 can be expressed as follows.

[0218] [Formula 3]

[0219]

[0220] When the angle θ2 is smaller than the angle θ1 (θ2<θ1), the image I 11 Like I 12 Therefore, for I 11 and like I 12 The conditions for partial overlap are as follows.

[0221] [Formula 4]

[0222]

[0223] In addition, since the magnitude relationship in the parentheses of the above formula is (2t-D) / 2f<D / 2f, the image I 11 Like I 12 The condition that a part of overlaps can also be expressed as t<D.

[0224] By satisfying the condition of the above formula (or t<D), two adjacent irradiation spots (two irradiation spots belonging to the same irradiation spot group) partially overlap. As a result, it is possible to suppress the formation of a gap between two adjacent irradiation spots, and it is possible to suppress the generation of an area in the measurement area 2050 where light cannot be irradiated. Therefore, it is preferable to satisfy the condition of the above formula. In addition, in this embodiment, by using a super lens 2016, the diameter of the lens can be set smaller, or the offset of the optical axis of the lens can be set smaller, so even if the diameter D of the light emitting point of the light emitting element 2121 is small, it is easy to realize a projection optical system 2014 that satisfies the condition of the above formula.

[0225] Fig.37 This is an explanatory diagram of the images of the light emitting points of the plurality of light emitting elements 2121 formed by the plurality of super lenses 2016 (a plurality of irradiation light spot groups). The plurality of circular images (irradiation light spots) in the figure are Fig.33 Same as shown.

[0226] in addition, Fig.37 The area surrounded by the thick line in the figure is an image of a certain light-emitting point (one light-emitting point) formed by multiple super lenses 2016, which represents the irradiation spot group. Fig.36 Here, since two super lenses 2016 are arranged in the X direction and two irradiation spots are arranged in the Y direction in the area surrounded by the bold line in the figure. In addition, when N super lenses 2016 are arranged in the X direction and N irradiation spots are arranged in the X direction and N irradiation spots are arranged in the Y direction in the area surrounded by the bold line in the figure. Fig.31 As shown, the plurality of light emitting elements 2121 are arranged two-dimensionally along the X direction and the Y direction, so that the plurality of irradiation spot groups ( Fig.37 The area surrounded by the thick line) is also arranged two-dimensionally along the X direction and the Y direction.

[0227] in addition, Fig.37 The multiple images (multiple irradiation spots arranged at intervals) with shadows are the images (irradiation spots) of the light-emitting points of the multiple light-emitting elements 2121 formed by a certain super lens 2016 (one super lens 2016). Fig.32The image shown is the same as the image shown. The image shown by the white circle (irradiation spot) is arranged between the images shown by the hatched lines. Here, since two super lenses 2016 are arranged in the X direction and the Y direction, an image represented by a white circle is arranged between the two images shown by the hatched lines. In addition, when N super lenses 2016 are arranged in the X direction and the Y direction, N-1 images (images represented by white circles) are arranged between the two images shown by the hatched lines.

[0228] like Fig.37 As shown, two adjacent irradiation spot groups (areas surrounded by thick lines) in the X direction and the Y direction partially overlap. By overlapping adjacent irradiation spot groups, it is possible to suppress the formation of a gap between the two adjacent irradiation spot groups, and it is possible to suppress the generation of an area in the measurement area 2050 that cannot be irradiated with light.

[0229] Fig.39 This is a diagram for explaining the optical conditions for partially overlapping two irradiation spot groups adjacent to each other in a predetermined direction (X direction or Y direction).

[0230] S2 in the figure represents a light-emitting point adjacent to the light-emitting point S1 in a predetermined direction (X direction or Y direction). Here, the distance between the light-emitting elements 2121 adjacent in the predetermined direction (the distance between the centers of the light-emitting points) is set to P. L1, L2 in the figure N 2016 located at the end of a predetermined direction (N represents the number of the hyperlenses 2016 arranged in the predetermined direction. In the figure, for the sake of simplicity, the second hyperlens L2 is depicted as N=2). N The super lens represented by is called the Nth super lens. 1N Represents the Nth superlens L N The image of the luminous point S1. 21 : represents the image of the light emitting point S2 based on the first super lens L1. 11 ~Like I 1N Belong to the same illumination spot group, like I 21 Belongs to and like I 11 ~Like I 1N The irradiation spot group is adjacent to the irradiation spot group.

[0231] θ3 in the figure is the distance between the center of the first super lens L1 and the image I 11 The line connecting the centers of N The center and image I of the second super lens L2 1N (I 12 ) of the upper end (adjacent image I 21 In addition, the Nth super lens LN The center and image I 1N (I 12 ) is located between the lower end of the light emitting point S1 and the Nth super lens L N The angle θ3 is the extension of the line connecting the center of the second super lens L2. The angle θ3 is equivalent to half of the viewing angle of the irradiation spot group. The angle θ3 can be expressed as follows (the above formula is a formula for the angle θ3 when N=2, and the first term on the right side of the above formula represents the offset of the image center of one lens).

[0232] [Formula 5]

[0233]

[0234] In addition, θ4 in the figure is the center of the first super lens L1 and the image I 11 The line connecting the center of the first super lens L1 and the image I 21 The lower end (adjacent image I 1N In addition, the center of the first super lens L1 and the image I 21 The line connecting the lower ends of is located on the extension line of the line connecting the upper end of the light-emitting point S2 and the center of the first super lens L1. The angle θ4 can be expressed as follows.

[0235] [Formula 6]

[0236]

[0237] When the angle θ4 is smaller than the angle θ3 (θ4<θ3), the image I 1N Like I 21 Therefore, for example, I 1N Like I 21 The conditions for partial overlap of are as follows (in addition, in the following formula, it is modified in a way that the t term is retained on the right side).

[0238] [Formula 7]

[0239]

[0240] By satisfying the above condition, two adjacent irradiation spot groups partially overlap. As a result, it is possible to suppress the formation of a gap between two adjacent irradiation spot groups, and it is possible to suppress the generation of an area where light cannot be irradiated on the measurement area 2050. Therefore, it is preferable to satisfy the above condition. In addition, the condition shown in the above equation 3 (or t<D) specifies the upper limit of t, while the condition shown in the above equation 6 specifies the lower limit of t.

[0241] ===Conclusion===

[0242] The measuring device 2001 of this embodiment includes a light emitting unit 2012 and a light projection optical system 2014 for irradiating the light of the light emitting unit 2012 to a measuring area 2050. Figure 31 to Figure 33 As shown in FIG. 1 , the light-emitting unit 2012 has a plurality of light-emitting elements 2121 arranged at intervals. The light-projecting optical system 2014 has a plurality of super lenses 2016 that offset the optical axis. The light-projecting optical system 2014 of this embodiment irradiates light from the light-emitting element 2121 through another super lens 2016 between the lights of the plurality of light-emitting elements 2121 irradiated through a certain super lens 2016. That is, the light-projecting optical system 2014 of this embodiment forms a plurality of irradiation spots ( Fig.37 , and between the plurality of irradiation spots, an irradiation spot is formed by light irradiated from the light emitting element 2121 via another super lens 2016 ( Fig.37 The illumination spot is shown by the white circle in the figure). Therefore, Fig.32 Compared with the case shown in the figure, the generation of an area where light cannot be irradiated can be suppressed.

[0243] In this embodiment, the plurality of super lenses 2016 are provided on a common plane, thereby preventing shadows from being formed in the measurement region 2050 .

[0244] In this embodiment, the images of the light-emitting points of a certain light-emitting element 2121 (one light-emitting element 2121) formed by two super lenses 2016 adjacent in a predetermined direction partially overlap. That is, in this embodiment, Fig.36 In this way, the occurrence of an area where light cannot be irradiated can be further suppressed. In addition, even if the images (irradiation spots) of the light emitting points of a certain light emitting element 2121 (one light emitting element 2121) formed by two super lenses 2016 adjacent in a predetermined direction do not overlap, as long as the light (irradiation spots) of the plurality of light emitting elements 2121 irradiated via a certain super lens 2016 can be Fig.37 The light from the light emitting element 2121 is irradiated through another super lens 2016 ( Fig.37 The illumination spot shown by the white circle) is Fig.32 Compared with the case shown in the figure, the occurrence of a region where light cannot be irradiated can be suppressed.

[0245] In this embodiment, the light emitting unit 2012 and the light projection optical system 2014 satisfy the condition shown in the above equation 3 (or t<D) (see Fig.38). Thus, it is possible to overlap a portion of the image (irradiation spot) of the light emitting point of a certain light emitting element 2121 (one light emitting element 2121) formed by two super lenses 2016 adjacent in a predetermined direction, thereby suppressing the occurrence of an area where light cannot be irradiated.

[0246] In this embodiment, the images formed by the plurality of super lenses 2016 and emitted from the light emitting points of two light emitting elements 2121 adjacent in a predetermined direction partially overlap. That is, in this embodiment, Fig.37 In this way, the occurrence of an area where light cannot be irradiated can be further suppressed. In addition, even if the images (irradiation spot groups) formed by the plurality of super lenses 2016 irradiated from the light emitting points of two light emitting elements 2121 adjacent in a predetermined direction do not overlap, as long as the light of the plurality of light emitting elements 2121 irradiated via a certain super lens 2016 (see Fig.37 The light from the light emitting element 2121 is irradiated through another super lens 2016 (refer to Fig.37 The illumination spot shown by the white circle) is Fig.32 Compared with the case shown in the figure, the occurrence of a region where light cannot be irradiated can be suppressed.

[0247] In this embodiment, the light emitting unit 2012 and the light projection optical system 2014 satisfy the condition shown in the above equation 6 (see Fig.39 ). Thus, it is possible to overlap a portion of the images (irradiation spot group) formed by the plurality of super lenses 2016 and irradiated from the light emitting points of two light emitting elements 2121 adjacent in a predetermined direction, thereby suppressing the occurrence of areas where light cannot be irradiated.

[0248] In this embodiment, both the light emitting unit 2012 and the light projection optical system 2014 satisfy the conditions shown in the above equation 3 (or t<D) and equation 6 (see Fig.38 and Fig.39 ). Thus, the irradiation spots in the same irradiation spot group overlap, and the irradiation spots between adjacent irradiation spot groups can also overlap, which can prevent the occurrence of areas where light cannot be irradiated.

[0249] The embodiments of the present disclosure are described in detail above, but the present disclosure is not limited to the above embodiments, and includes various modifications. In addition, the above embodiments are embodiments that describe the structure in detail in order to easily explain the present disclosure, and are not necessarily limited to having all the structures described. In addition, with respect to a part of the structure of the above embodiments, other structures can be added, deleted, or replaced.

[0250] This application is based on the Japanese patent application (Japanese Patent Application No. 2022-106333) filed on June 30, 2022, the Japanese patent application (Japanese Patent Application No. 2022-106334) filed on June 30, 2022, and the Japanese patent application (Japanese Patent Application No. 2022-127331) filed on August 9, 2022, the contents of which are incorporated herein by reference.

Claims

1. A measuring device comprising: a light emitting unit that emits light of a wavelength corresponding to the temperature within a predetermined wavelength range; an optical filter that allows light of the predetermined wavelength band to pass therethrough and allows reflected light of the light irradiated from the light emitting unit to pass therethrough; A light receiving sensor having a plurality of light receiving elements; The dispersion element is disposed between the optical filter and the light receiving sensor and disperses the light having passed through the optical filter toward two or more of the light receiving elements.

2. The measuring device according to claim 1, wherein have: Temperature sensor; A control unit measures a distance based on light reception data of the light receiving element corresponding to the temperature data of the temperature sensor.

3. The measuring device according to claim 1, wherein have: Temperature sensor; The control unit outputs a different distance when the temperature data of the temperature sensor changes under the condition that the light receiving element outputs the predetermined light receiving data.

4. The measuring device according to claim 2 or 3, wherein: A storage unit is provided for storing weight data corresponding to the temperature data of the temperature sensor, The control unit acquires the weight data corresponding to the temperature data of the temperature sensor from the storage unit, The distance is measured by weighting the light receiving data of each of the two or more light receiving elements according to the weight data.

5. The measuring device according to claim 1, wherein The dispersive element is made of metamaterial.

6. The measuring device according to claim 5, wherein: The dispersion element has a function of focusing the light having passed through the optical filter on the light receiving sensor.

7. The measuring device according to claim 5 or 6, wherein: The dispersion element has a function of transmitting light vibrating in a predetermined direction and absorbing light vibrating in a direction intersecting the predetermined direction.

8. The measuring device according to claim 1, wherein The dispersion element is composed of a prism or a diffraction grating.

9. The measuring device according to claim 1, wherein: A condenser lens is provided, which is disposed between the optical filter and the dispersion element and condenses the light having passed through the optical filter onto the dispersion element.

10. A measuring device comprising: a light emitting unit that emits light of a wavelength corresponding to the temperature; a bandpass filter that passes reflected light of the light irradiated from the light emitting portion; a light receiving sensor for receiving light having passed through the band pass filter, The wavelength of light that can pass through the bandpass filter is changed according to temperature.

11. The measuring device according to claim 10, wherein: The bandpass filter comprises a substrate and a thin film formed on the substrate. A plurality of protrusions are arranged in a predetermined pattern on the surface of the film, The intervals between the protrusions vary depending on temperature.

12. The measuring device according to claim 11, wherein The linear expansion coefficient of the substrate is greater than the linear expansion coefficient of the film.

13. The measuring device according to claim 12, wherein: The substrate is made of a light-transmitting resin.

14. The measuring device according to claim 11 or 12, wherein The protrusion is configured as a column, The plurality of protrusions are arranged in a lattice pattern.

15. The measuring device according to claim 11 or 12, wherein The protrusion is configured as a convex strip, The plurality of convex strips are arranged side by side in a predetermined direction.

16. The measuring device according to any one of claims 10 to 12, wherein It also includes a focusing lens for focusing light onto the light receiving sensor, The bandpass filter is arranged between the condenser lens and the light receiving sensor.

17. The measuring device according to any one of claims 10 to 12, wherein The light emitting unit emits light of a wavelength corresponding to the temperature within a predetermined wavelength range. A band pass filter that allows light in the predetermined wavelength band to pass therethrough and that is different from the band pass filter is further provided.

18. A bandpass filter comprising: substrate; and a thin film formed on the substrate, A plurality of protrusions are arranged in a predetermined pattern on the surface of the film, By changing the interval between the protrusions according to the temperature, the wavelength of light that can pass therethrough is changed.

19. A measuring device comprising: a light emitting unit having a plurality of light emitting elements arranged at intervals; An optical system includes a plurality of super lenses with optical axes offset, wherein between the lights of the plurality of light emitting elements irradiated via a certain super lens, the lights from the light emitting elements are irradiated via another of the super lenses.

20. The measuring device according to claim 19, wherein A plurality of the super lenses are arranged on a common plane.

21. The measuring device according to claim 19 or 20, wherein The images of the light-emitting point of a certain light-emitting element formed by two of the super lenses adjacent to each other in a predetermined direction partially overlap.

22. The measuring device according to claim 19 or 20, wherein: When the diameter of the light emitting point of the light emitting element is set to D, When the interval between the super lenses arranged in a predetermined direction is t, The condition of t<D is satisfied.

23. The measuring device according to claim 19 or 20, wherein: Images emitted from light-emitting points of two of the light-emitting elements adjacent in a predetermined direction and formed by the plurality of super lenses partially overlap.

24. The measuring device according to claim 19 or 20, wherein When the focal length of the metalens is set to f, The diameter of the light emitting point of the light emitting element is set to D, The interval between the light emitting elements arranged in a predetermined direction is set to P, The interval between the super lenses arranged in the predetermined direction is t, When the number of the super lenses arranged in the predetermined direction is N, Satisfies [Equation 8] conditions.

25. The measuring device according to claim 19 or 20, wherein When the focal length of the metalens is set to f, The diameter of the light emitting point of the light emitting element is set to D, The interval between the light emitting elements arranged in a predetermined direction is set to P, The interval between the super lenses arranged in the predetermined direction is t, When the number of the super lenses arranged in the predetermined direction is N, satisfy t<D and [Formula 9] conditions.

26. An irradiation device comprising: a light emitting unit having a plurality of light emitting elements arranged at intervals; An optical system includes a plurality of super lenses with optical axes offset, wherein between the lights of the plurality of light emitting elements irradiated via a certain super lens, the lights from the light emitting elements are irradiated via another of the super lenses.

Images