3D ranging module and 3D ranging system

Abstract

A three-dimensional ranging module (1) comprises: a light source (10) for emitting laser light; a lens module (20) that includes a lens (21) for condensing light obtained when the emitted laser light has been reflected by a subject, an imaging element (23) for receiving the light condensed by the lens (21), and a lens barrel (22) that encloses the space between the lens (21) and the imaging element (23) and supports the lens (21); and a lens cover (30) that is located between the lens module (20) and the subject, and is transparent to the wavelength of the laser light. In a cross-sectional view in which the lens barrel (22) is sectioned by a plane that includes an optical axis (A1) of the lens (21), a first surface (221), of the lens barrel, (22) facing the subject includes a first inclined section that becomes further distanced from the lens cover (30) as the distance of the inclined section from the optical axis (A1) increases.

Description

Technical Field

[0001] The present disclosure relates to a three-dimensional distance measurement module and a three-dimensional distance measurement system.

Background Art

[0002] By using ToF (Time of Flight), a distance measurement imaging device (ToF camera) that measures the distance to an object is known.

[0003] For example, in Patent Document 1, a ToF camera includes a three-dimensional distance measurement module having a light source, a lens module, and a lens base that holds the lens module. In this ToF camera, the lens module receives the light emitted from the light source, and the distance to the object is measured by calculating the distance from the time difference between the irradiation and the reception.

Prior Art Documents

Patent Documents

[0004]

Patent Document ⑴

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, the three-dimensional distance measurement module may have a lens cover between the object and the lens module for protecting the lens module. In this case, an incorrect calculation of the distance may sometimes occur.

[0006] Therefore, the present disclosure provides a three-dimensional distance measurement module in which the occurrence of incorrect calculation of the distance is suppressed. <0000​​​​​The three-dimensional distance measuring module of this disclosure includes a light source that emits laser light, a lens module that includes a lens barrel that surrounds the space between the lens and the image sensor and supports the lens, and a lens cover that is located between the lens module and the object and is transparent to the wavelength of the laser light, wherein in a cross-sectional view when the lens barrel is cut along a plane including the optical axis of the lens, the first surface of the lens barrel facing the object includes a first inclined portion that is inclined away from the lens cover as it moves away from the optical axis.

[0008] Furthermore, the three-dimensional distance measuring module of this disclosure comprises a light source that emits laser light, a lens that focuses the light reflected by an object from the emitted laser light, an image sensor that receives the light focused by the lens, a lens cover located between the lens and the object and transparent to the wavelength of the laser light, and a member having an opening that encloses the lens when the lens is viewed from the lens cover in the direction of the optical axis of the lens. In a cross-sectional view when the lens is cut by a plane including the optical axis, the distance between the outer end of the lens and the outer end of the opening is B, the distance between the lens cover and the center of the lens is H1, the distance between the lens cover and the second surface of the member facing the lens cover is H2, and the angle between the line connecting the center of the lens and the outer end of the image sensor and the optical axis is θ, such that the relationship (H1+H2)·tanθ≦B is satisfied.

[0009] Furthermore, the three-dimensional distance measuring module of this disclosure includes a light source that emits laser light, a lens module that includes a lens barrel that surrounds the space between the lens and the image sensor and supports the lens, a third surface of the lens cover that faces the lens module and includes a third inclined portion that is inclined to move away from the lens module as it moves away from the optical axis of the lens.

[0010] Furthermore, the three-dimensional distance measuring system of this disclosure includes the three-dimensional distance measuring module described above, and the three-dimensional distance measuring module has a calculation unit that calculates the distance from the light source to the object based on the travel time of the laser beam.

[0011] These comprehensive or specific embodiments may be implemented as a system, method, integrated circuit, computer program, or recording medium such as a computer-readable CD-ROM, or as any combination of a system, method, integrated circuit, computer program, and recording medium. [Effects of the Invention]

[0012] According to one aspect of this disclosure, a 3D distance measuring module, etc., can suppress the occurrence of distance miscalculations. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 shows a distance image in which an intensity flare region occurred. [Figure 2] Figure 2 is a block diagram showing an example configuration of a 3D distance measuring module according to Embodiment 1. [Figure 3] Figure 3 is a top view and two cross-sectional views of a three-dimensional distance measuring module according to Embodiment 1. [Figure 4] Figure 4 is an enlarged cross-sectional view of the area around the lens barrel according to Embodiment 1. [Figure 5] FIG. 5 is a cross-sectional view showing the behavior of the laser beam according to Embodiment 1. [Figure 6] FIG. 6 is a diagram showing the influence on the flare light amount when the inclination angle of the first inclined portion according to Embodiment 1 is changed. [Figure 7] FIG. 7 is a diagram showing the relationship between the distance between the three-dimensional ranging module according to Embodiment 1 and the object and the distance between the three-dimensional ranging module and another object. [Figure 8] FIG. 11 is a cross-sectional view showing another behavior of the laser beam according to Embodiment 1. [Figure 9] FIG. 9 is another diagram showing the influence on the flare light amount when the inclination angle of the first inclined portion according to Embodiment 1 is changed. [[ID=​​​​​​​​​​​​​​​​​​​​​​​​FIG. 18 is a top view of a lens barrel and a lens and a cross-sectional view of the lens barrel according to Modified Example 1 of Embodiment 1. [Figure 19] FIG. 19 is a diagram showing the relationship between δ and β according to Modified Example 1 of Embodiment 1. [Figure 20] FIG. 20 is a top view and two cross-sectional views of a three-dimensional distance measurement module according to Modified Example 2 of Embodiment 1. [Figure 21] FIG. 21 is a cross-sectional view showing the behavior of laser light according to Modified Example 2 of Embodiment 1. [Figure 22] FIG. 22 is a cross-sectional view showing another behavior of laser light according to Modified Example 2 of Embodiment 1. [Figure 23] FIG. 23 is a cross-sectional view of a three-dimensional distance measurement module according to Modified Example 3 of Embodiment 1. [Figure 24] FIG. 24 is a diagram showing the influence on the flare light amount when the tilt angle of the first inclined portion according to Modified Example 3 of Embodiment 1 is changed. [Figure 25] FIG. 25 is another diagram showing the influence on the flare light amount when the tilt angle of the first inclined portion according to Modified Example 3 of Embodiment 1 is changed. [Figure 26] FIG. 26 is another diagram showing the influence on the flare light amount when the tilt angle of the first inclined portion according to Modified Example 3 of Embodiment 1 is changed. [Figure 27] FIG. 27 is another diagram showing the influence on the flare light amount when the tilt angle of the first inclined portion according to Modified Example 3 of Embodiment 1 is changed. [Figure 28] FIG. 28 is another diagram showing the influence on the flare light amount when the tilt angle of the first inclined portion according to Modified Example 3 of Embodiment 1 is changed. [Figure 29] FIG. 29 is a top view and a cross-sectional view of a three-dimensional distance measurement module according to Embodiment 2. [Figure 30] FIG. 30 is a diagram showing the influence on the flare light amount when D, B, H1, and H2 according to Embodiment 2 are changed. [Figure 31]Figure 31 is another figure showing the effect on flare light intensity when D, B, H1, and H2 in Embodiment 2 are changed. [Figure 32] Figure 32 is another figure showing the effect on flare light intensity when D, B, H1, and H2 in Embodiment 2 are changed. [Figure 33] Figure 33 is another figure showing the effect on flare light intensity when D, B, H1, and H2 in Embodiment 2 are changed. [Figure 34] Figure 34 is a top view and two cross-sectional views of a three-dimensional distance measuring module according to a modified example 1 of Embodiment 2. [Figure 35] Figure 35 is a top view of a substrate according to a modified example 1 of Embodiment 2. [Figure 36] Figure 36 is a cross-sectional view of a three-dimensional distance measuring module according to the sixth embodiment. [Figure 37] Figure 37 is a top view and a cross-sectional view of a three-dimensional distance measuring module according to a modified example 2 of Embodiment 2. [Figure 38] Figure 38 is a cross-sectional view of a three-dimensional distance measuring module according to Embodiment 3. [Figure 39] Figure 39 shows the effect on the amount of flare light when the inclination angle of the third inclined section according to Embodiment 3 is changed. [Figure 40] Figure 40 is another figure showing the effect on the amount of flare light when the inclination angle of the third inclined section according to Embodiment 3 is changed. [Figure 41] Figure 41 is a top view and two cross-sectional views of a three-dimensional distance measuring module according to a modified example 1 of Embodiment 3. [Figure 42] Figure 42 is a cross-sectional view showing the behavior of light in a three-dimensional distance measuring module according to a modified example 1 of Embodiment 3. [Figure 43] Figure 43 shows the effect on the amount of flare light when the inclination angle of the third inclined section is changed in a modified example 1 of Embodiment 3. [Figure 44] Figure 44 is another figure showing the effect on the amount of flare light when the inclination angle of the third inclined section is changed in a modified example 1 of Embodiment 3. [Figure 45] Figure 45 is a top view and a cross-sectional view of a three-dimensional distance measuring module according to a modified example 2 of Embodiment 3. [Figure 46] Figure 46 shows the relationship between δ and ζ in a modified example 2 of Embodiment 3. [Figure 47] Figure 47 is a top view and two cross-sectional views of a three-dimensional distance measuring module according to a modified example 3 of Embodiment 3. [Figure 48] Figure 48 is a cross-sectional view of a three-dimensional distance measuring module according to a modified example 4 of Embodiment 3. [Figure 49] Figure 49 is a top view and a cross-sectional view of a three-dimensional distance measuring module according to Embodiment 4. [Figure 50] Figure 50 is a cross-sectional view of a three-dimensional distance measuring module according to Embodiment 5. [Modes for carrying out the invention]

[0014] (Knowledge obtained to obtain one aspect of this disclosure) The inventors have found that the following problems arise with the 3D distance measuring module.

[0015] A 3D ranging module may have a lens cover between the object and the lens module. When a ranging imaging device equipped with a 3D ranging module is used outdoors, a lens cover is provided to protect the lens module, which consists of the lens and the lens barrel that supports the lens. In addition, to minimize the visibility of the 3D ranging module itself, a lens cover that is transparent to wavelengths of light emitted by a light source, such as infrared light, and opaque to visible light is used.

[0016] When light emitted for distance measurement reflects off an object and returns, the object will be observed as a bright spot of high brightness if it is close to the object or if the object has a highly reflective surface (especially if the object is concave, and that concave shape has a focal point, and the focal length of that focal point coincides with the distance to the object).

[0017] Let's explain this in more detail using Figure 1.

[0018] Figure 1 shows a distance image where an intensity flare region occurs. More specifically, Figure 1(a) is a distance image where no intensity flare light is generated, and Figure 1(b) is a distance image where intensity flare light is generated. Here, in the distance image, darker colors indicate greater distance. Note that areas where the object is far away or where the reflectivity of the object is extremely low, resulting in light returning from the object being too weak to calculate the distance, are shown in white. As shown in Figure 1(b), intensity flare light is generated when an object with a highly reflective surface (object X) is placed in the center of the screen.

[0019] Light emitted from the distance-measuring light source is reflected by an object (object X), and this reflected light passes through the lens cover and directly enters the lens of the lens module, forming an image at a single point on the image sensor of the 3D distance-measuring module.

[0020] Furthermore, some of the reflected light from object X, which does not directly enter the lens but is reflected (scattered) by the surface of the lens barrel facing object X (top surface), may be re-reflected by the surface of the lens cover facing the lens module (bottom surface), enter the lens, and form an image on the image sensor. At this time, the light re-reflected by the bottom surface and entering the lens will be imaged at a different point on the image sensor than the light that directly entered the lens. This state is described as the generation of high-intensity flare light. In Figure 1(b), a ring-shaped high-intensity flare region is generated by high-intensity flare light.

[0021] On the other hand, at the point where the intense flare light forms an image, light reflected by another object (object Y) separate from object X, that is, light that reaches the image sensor from a different direction than the light that was re-reflected from the lower surface of the lens cover and entered the lens, also directly enters the lens and forms an image. Therefore, at the point where the intense flare light forms an image, the distance is calculated based on the travel times of light from two different locations.

[0022] In 3D ranging modules, the reflectivity of the lens barrel and lens cover is generally designed to be low to avoid stray light, resulting in relatively weak intensity flare. However, since the reflected light intensity decreases inversely proportional to the square of the distance ratio, when object Y is farther away from object X, the reflected light intensity from object Y becomes significantly smaller, and there are times when the intensity of the flare from object X becomes stronger than the reflected light intensity from object Y.

[0023] In this case, the distance to object Y is calculated based on the intensity flare light from object X, which is stronger, relative to the direction in which object Y is located. This leads to a problem where the distance is miscalculated (an intensity flare region is created).

[0024] Therefore, this disclosure provides a 3D distance measuring module in which the occurrence of distance miscalculations is suppressed.

[0025] A three-dimensional distance measuring module according to one aspect of the present disclosure includes a light source that emits laser light, a lens module including a lens barrel that surrounds the space between the lens and the image sensor and supports the lens, and a lens cover located between the lens module and the object and transparent to the wavelength of the laser light, wherein in a cross-sectional view when the lens barrel is cut along a plane including the optical axis of the lens, the first surface of the lens barrel facing the object includes a first inclined portion that is inclined away from the lens cover as it moves away from the optical axis.

[0026] According to this, when laser light reflected by an object corresponding to a bright spot is reflected by the first surface (first inclined portion), the light (intensity flare light) reaching the lens and image sensor is suppressed. In other words, since the amount of intensity flare light reaching the lens and image sensor is suppressed, a 3D distance measuring module can be realized that suppresses the occurrence of distance miscalculations.

[0027] For example, the first inclined portion may be formed over the entire first surface.

[0028] According to this, when laser light reflected by an object corresponding to a bright spot is reflected by the first surface (first inclined portion), the laser light is more likely to be reflected from the first surface (first inclined portion) in the direction away from the lens and image sensor. In other words, the amount of intensity flare light reaching the lens and image sensor is further suppressed, making it possible to realize a 3D distance measuring module that further suppresses the occurrence of distance miscalculations.

[0029] For example, the half-width of the light scattering angle of the laser beam on the first surface may be 45 degrees or more.

[0030] According to this, the laser light reflected by the object corresponding to the bright spot is diffusely reflected by the first surface (first inclined portion). Therefore, the light (intensity flare light) reaching the lens and image sensor is further suppressed. In other words, since the amount of intensity flare light reaching the lens and image sensor is further suppressed, it is possible to realize a 3D distance measuring module in which the occurrence of distance miscalculations is further suppressed.

[0031] For example, in the cross-sectional view, the angle between the first inclined portion and the surface of the lens cover facing the lens module may be 30 degrees or more.

[0032] According to this, because the angle between the first inclined portion and the surface of the lens cover facing the lens module is sufficiently large, the light (intensity flare light) reaching the lens and image sensor is further suppressed. In other words, because the amount of intensity flare light reaching the lens and image sensor is further suppressed, a 3D distance measuring module can be realized that further reduces the occurrence of distance miscalculations.

[0033] For example, in the cross-sectional view, the first inclined portion may be linear.

[0034] According to this, the amount of high-intensity flare light reaching the lens and image sensor is further suppressed, making it possible to realize a 3D distance measuring module that further reduces the occurrence of distance miscalculations.

[0035] For example, when viewed from the direction of the optical axis, the outer shape of the lens barrel may be similar in shape to the outer shape of the image sensor, and the degree of inclination of the first inclined portion from a plane perpendicular to the optical axis may have a positive correlation with the distance between the optical axis and the outer end of the lens barrel.

[0036] According to this, the amount of flare light reaching the image sensor is further suppressed, making it possible to realize a 3D distance measuring module that further reduces the occurrence of distance miscalculations.

[0037] For example, the half-width of the light scattering angle of the laser light on the first surface may be 7 degrees or less.

[0038] According to this, the laser light reflected by the object corresponding to the bright spot is reflected at the first surface (first inclined portion) in a state where light diffusion is suppressed. Even in this case, the light (intensity flare light) reaching the lens and image sensor is further suppressed. In other words, since the amount of intensity flare light reaching the lens and image sensor is further suppressed, a 3D distance measuring module can be realized that further suppresses the occurrence of distance miscalculations.

[0039] For example, when viewing the lens from the object side of the lens cover, if ε is the maximum angle between the optical axis and the direction in which the front side of the lens can be seen, the angle between the first inclined portion and the plane perpendicular to the optical axis may be ε / 2 or greater.

[0040] When laser light reflected by an object corresponding to a bright spot is reflected by the first surface (first inclined portion) in a state where light diffusion is suppressed, there is a possibility that light (intensity flare light) reaching the lens and image sensor may be generated due to reflection within the 3D distance measuring module. If the angle between the first inclined portion and the plane perpendicular to the optical axis of the lens is within the above-mentioned angular range, the laser light reflected by the object is reflected by the components of the 3D distance measuring module (e.g., light-shielding members), making it difficult for it to reach the lens and image sensor. In other words, the amount of intensity flare light reaching the lens and image sensor is further suppressed, making it possible to realize a 3D distance measuring module that further suppresses the occurrence of distance miscalculations.

[0041] For example, when viewing the lens from the lens cover in the direction of the optical axis of the lens, the lens may have a member having an opening that encloses the lens, and in the cross-sectional view when the lens barrel is cut along a plane containing the optical axis of the lens, the distance between the outer end of the lens and the outer end of the opening is B, the distance between the lens cover and the center of the lens is H1, the distance between the lens cover and the second surface of the member facing the lens cover is H2, and the angle between the line connecting the center of the lens and the outer end of the image sensor and the optical axis is θ, such that the relationship (H1+H2)·tanθ≦B is satisfied.

[0042] According to this, when laser light reflected by an object corresponding to a bright spot is diffusely reflected by the second surface, the light (intensity flare light) reaching the lens and image sensor is suppressed. In other words, since the overall amount of intensity flare light reaching the lens and image sensor is suppressed, a 3D distance measuring module can be realized that suppresses the occurrence of distance miscalculations.

[0043] For example, the third surface of the lens cover facing the lens module may include a third inclined portion that is inclined to move away from the lens module as it moves away from the optical axis.

[0044] According to this, when laser light reflected by an object corresponding to a bright spot is reflected by the third surface (third inclined section), the light (intensity flare light) reaching the lens and image sensor is suppressed. In other words, since the amount of intensity flare light reaching the lens and image sensor is suppressed, a 3D distance measuring module can be realized that suppresses the occurrence of distance miscalculations.

[0045] Furthermore, a three-dimensional distance measuring module according to one aspect of the present disclosure includes a light source that emits laser light, a lens that focuses the light reflected by an object from the emitted laser light, an image sensor that receives the light focused by the lens, a lens cover located between the lens and the object and transparent to the wavelength of the laser light, and a member having an opening that encloses the lens when the lens is viewed from the lens cover in the direction of the optical axis of the lens, wherein in a cross-sectional view when the lens is cut by a plane including the optical axis, the distance between the outer end of the lens and the outer end of the opening is B, the distance between the lens cover and the center of the lens is H1, the distance between the lens cover and the second surface of the member facing the lens cover is H2, and the angle between the line connecting the center of the lens and the outer end of the image sensor and the optical axis is θ, the relationship (H1+H2)·tanθ≦B is satisfied.

[0046] According to this, when laser light reflected by an object corresponding to a bright spot is diffusely reflected by the second surface, the light (intensity flare light) reaching the lens and image sensor is suppressed. In other words, since the overall amount of intensity flare light reaching the lens and image sensor is suppressed, a 3D distance measuring module can be realized that suppresses the occurrence of distance miscalculations.

[0047] For example, when viewed from the direction of the optical axis, the outer shape of the aperture may be barrel-shaped.

[0048] According to this, the amount of high-intensity flare light reaching the lens and image sensor is further suppressed, making it possible to realize a 3D distance measuring module that further reduces the occurrence of distance miscalculations.

[0049] For example, in the cross-sectional view, the second surface may include a second inclined portion that slopes away from the lens cover as it moves away from the optical axis.

[0050] According to this, when laser light reflected by an object corresponding to a bright spot is reflected by the second surface (second inclined section), the laser light is more likely to be reflected from the second surface (second inclined section) in the direction away from the lens and image sensor. In other words, the amount of intensity flare light reaching the lens and image sensor is further suppressed, making it possible to realize a 3D distance measuring module that further suppresses the occurrence of distance miscalculations.

[0051] Furthermore, a three-dimensional distance measuring module according to one aspect of the present disclosure includes a light source that emits laser light, a lens module that includes a lens barrel that surrounds the space between the lens and the image sensor and supports the lens, a third surface of the lens cover facing the lens module that is inclined away from the lens module as it moves away from the optical axis of the lens.

[0052] According to this, when laser light reflected by an object corresponding to a bright spot is reflected by the third surface (third inclined section), the light (intensity flare light) reaching the lens and image sensor is suppressed. In other words, since the amount of intensity flare light reaching the lens and image sensor is suppressed, a 3D distance measuring module can be realized that suppresses the occurrence of distance miscalculations.

[0053] For example, when viewed from the direction of the optical axis, the third inclined portion may be formed over the entire region in which the third inclined portion and the lens module overlap.

[0054] According to this, when laser light reflected by an object corresponding to a bright spot is reflected by the third surface (third inclined section), the laser light is more likely to be reflected from the third surface (third inclined section) in the direction away from the lens and image sensor. In other words, the amount of intensity flare light reaching the lens and image sensor is further suppressed, making it possible to realize a 3D distance measuring module that further suppresses the occurrence of distance miscalculations.

[0055] For example, the fourth surface of the lens cover facing the object may be flat.

[0056] In an environment where a 3D distance measuring module is used, if a person, who is an example of the object being measured, looks at the module, they may feel uncomfortable if there are irregularities on the fourth surface of the lens cover. Therefore, making the fourth surface flat eliminates this discomfort.

[0057] For example, when viewed from the direction of the optical axis, the outer shape of the third inclined portion may be similar in shape to the outer shape of the image sensor, and the degree of inclination of the third inclined portion from a plane perpendicular to the optical axis may have a positive correlation with the distance between the optical axis and the outer end of the third inclined portion.

[0058] According to this, the amount of high-intensity flare light reaching the lens and image sensor is further suppressed, making it possible to realize a 3D distance measuring module that further reduces the occurrence of distance miscalculations.

[0059] For example, a cavity may be provided in the space between the third surface of the lens cover and the fourth surface of the lens cover facing the object, and in a cross-sectional view when the lens cover is cut along the plane including the optical axis, the thickness from the third surface to the fourth surface in the direction of the optical axis, excluding the cavity, may be constant in the region where the cavity is provided.

[0060] According to this, image distortion in distance images obtained by a 3D ranging module can be suppressed.

[0061] For example, the shape of the third surface may include a lens shape, and the optical axis of the lens cover may coincide with the optical axis of the lens.

[0062] According to this, image distortion in distance images obtained by a 3D ranging module can be suppressed.

[0063] A three-dimensional distance measuring system according to one aspect of the present disclosure comprises the three-dimensional distance measuring module described above, the three-dimensional distance measuring module having a calculation unit that calculates the distance from the light source to the object based on the travel time of the laser beam.

[0064] Since the above-mentioned 3D distance measuring module can suppress the occurrence of distance miscalculations, a 3D distance measuring system equipped with such a 3D distance measuring module can suppress the occurrence of distance miscalculations.

[0065] The embodiments will be described in detail below with reference to the drawings.

[0066] The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement and connection configurations of components, manufacturing processes, and the sequence of manufacturing processes shown in the following embodiments are examples only and are not intended to limit this disclosure. Furthermore, any components in the following embodiments that are not described in an independent claim will be described as optional components.

[0067] Furthermore, each figure is a schematic diagram and not necessarily a strictly accurate representation. Therefore, for example, the scale may not necessarily match in each figure. Also, in each figure, substantially identical components are given the same reference numerals, and redundant explanations are omitted or simplified.

[0068] Furthermore, in this specification, terms indicating relationships between elements such as parallel or perpendicular, terms indicating the shape of elements such as rectangles or circles, and numerical ranges do not represent only strict meanings, but also include substantially equivalent ranges, such as differences of a few percent.

[0069] Furthermore, in this specification, the terms "up" and "down" in the configuration of the 3D ranging module do not refer to the upward (vertically upward) and downward (vertically downward) directions in absolute spatial perception, but rather are used as terms defined by the relative positional relationship based on the stacking order in the stacked configuration. Moreover, the terms "up" and "down" apply not only when two components are spaced apart and another component exists between them, but also when two components are placed in close proximity and touching each other.

[0070] Furthermore, in this specification and the drawings, the x-axis, y-axis, and z-axis represent the three axes of a three-dimensional Cartesian coordinate system. In each embodiment, the direction parallel to the lens of the 3D distance measuring module is defined as the z-axis direction, and the plane perpendicular to the z-axis direction is defined as the xy-plane. In addition, in the embodiments described below, the positive z-axis direction may be described as upward, and the negative z-axis direction may be described as downward.

[0071] (Embodiment 1) [composition] First, an example of the configuration of the 3D distance measuring module 1 included in the 3D distance measuring system 100 according to this embodiment will be explained with reference to Figure 2.

[0072] Figure 2 is a block diagram showing an example configuration of the 3D distance measuring module 1 according to this embodiment. In addition to the 3D distance measuring module 1, an object X is also shown in Figure 2. Object X is an example of an object to be measured for distance.

[0073] As shown in Figure 2, the 3D distance measuring system 100 includes a 3D distance measuring module 1, which comprises a light source 10, an image sensor 23, and a control unit 60. The control unit 60 includes a drive control unit 61, a frame control unit 62, a calculation unit 63, and a distance image generation unit 64.

[0074] The 3D distance measuring module 1 (3D distance measuring system 100) measures the distance between the 3D distance measuring module 1 and the object X as follows: The time of flight (ToF) of the light emitted from the light source 10, reflected by the object X, and returning to the image sensor 23 as reflected light is calculated from the amount of signal exposed by the image sensor 23, and the distance is derived by multiplying this by an appropriate coefficient.

[0075] The light source 10 emits pulsed light at the timing of the light emission control pulse included in the light emission control signal from the drive control unit 61 of the control unit 60. If there are people in the vicinity, infrared light is preferable, but if there are no people in the vicinity, other types of light may be used.

[0076] The image sensor 23 exposes the reflected light from the object irradiated with pulsed light at the timing of the exposure control pulse, and outputs an exposure signal indicating the amount of signal charge generated by the exposure. The image sensor 23 includes a solid-state image sensor called an image sensor. The image sensor 23 captures images with a resolution of, for example, 20,000 to 2 million pixels. The image sensor 23 may be divided into one for image acquisition and one for distance measurement.

[0077] The drive control unit 61 outputs a light emission control signal including a light emission control pulse that instructs the timing of light emission, and an exposure control signal including an exposure control pulse that instructs the timing of exposure. The drive control unit 61 generates a light emission control signal based on the timing of the light emission control pulse. The image sensor 23 outputs an exposure signal indicating the amount of signal charge generated by exposure using the exposure control pulse. The calculation unit 63 of the control unit 60 converts the ratio of the signal charge amounts of the exposure signal into travel time and outputs distance information. In other words, the calculation unit 63 calculates the distance from the light source 10 to the object based on the travel time of the laser beam. The frame control unit 62 outputs a frame identification signal related to distance measurement to the drive control unit 61 and the distance image generation unit 64. The distance image generation unit 64 generates a distance image based on the acquired frame identification signal and distance information.

[0078] Furthermore, the 3D distance measuring module 1 will be explained using Figure 3.

[0079] Figure 3 shows a top view and two cross-sectional views of the 3D distance measuring module 1 according to this embodiment.

[0080] More specifically, Figure 3(a) is a top view of the 3D ranging module 1, and Figure 3(b) is a cross-sectional view of the 3D ranging module 1 along the line IIIb-IIIb in Figure 3(a). Figure 3(c) is a cross-sectional view of the 3D ranging module 1 along the line IIIc-IIIc in Figure 3(a).

[0081] Note that in Figure 3(a), a top view is shown with the lens cover 30 removed for clarity. The same applies to the subsequent top views.

[0082] As described above, the 3D distance measuring module 1 comprises a light source 10, an image sensor 23, and a control unit 60. More specifically, as shown in Figure 3, it comprises a light source 10, a lens module 20, a lens cover 30, a control unit 60, a substrate 40, a light-shielding member 51, a substrate holder 52, a housing side portion 53, and a housing bottom portion 54.

[0083] Light source 10 is a light source that emits laser light and is a semiconductor laser device.

[0084] The laser light emitted by light source 10 is in the infrared region, and for example, the peak wavelength of the laser light is 850 nm or 940 nm. The wavelength full width at half maximum (FWHM) of the laser light is 3 nm. Light source 10 is a surface-emitting semiconductor laser device, and the size of the emission surface is 3.5 mm × 3.5 mm. The output power of the laser light is 1 W. Note that the wavelength, wavelength full width at half maximum, emission surface, and output power of the laser light emitted by light source 10 are not limited to those described above.

[0085] The light source 10 may have a component that diffuses (scatters) the laser light. For example, the light source 10 may have a light-diffusing glass component, which diffuses the laser light and controls its light distribution.

[0086] The laser light emitted from the light source 10 is reflected by the object X, passes through the lens cover 30, and reaches the lens 21 of the lens module 20. More specifically, a portion of the laser light emitted from the light source 10 reaches the lens 21.

[0087] Lens 21 is an optical component that focuses the light reflected by the object X from the laser beam irradiated by the light source 10. As shown in Figure 3, lens 21 is a plano-convex lens, but other lens shapes are also acceptable as long as they can focus the reflected light.

[0088] Lens 21 has a lens radius of 5 mm and a focal length of 2 mm, but is not limited to these. Also, the half-angle of view of lens 21 is 70 degrees, but is not limited to these. The half-angle of view is half the value of the angle of view, which indicates the range that the image sensor 23 can capture. Furthermore, the point through which the optical axis A1 of lens 21 passes on the plane (bottom surface) of lens 21 is defined as the center 211 of lens 21. Light focused by such lens 21 reaches the image sensor 23.

[0089] The image sensor 23 in the lens module 20 is an element that receives light focused by the lens 21. The image sensor 23 includes pixels for distance measurement and pixels for images, more specifically, 640 × 480 or 320 × 240 pixels for distance measurement and 640 × 480 or 320 × 240 pixels for images. The top view shown in Figure 3(a) is a view from the direction of the optical axis A1 of the lens 21, and in the top view, the outer shape of the image sensor 23 is rectangular, more specifically, rectangular. The shape of the image sensor 23 is flat and arranged parallel to the xy plane.

[0090] Next, the lens barrel 22 of the lens module 20 will be described. As shown in Figure 3, the lens barrel 22 has a bottomless cylindrical shape and is cylindrical in shape. A cylindrical cavity is formed inside the lens barrel 22. The lens barrel 22 also surrounds the space between the lens 21 and the image sensor 23. In other words, the space between the lens 21 and the image sensor 23 is located inside the lens barrel 22. The lens barrel 22 extends along the optical axis A1 of the lens 21, and the optical axis A1 of the lens 21 and the axis of the lens barrel 22 coincide. As described above, the lens barrel 22 is cylindrical, and the cross-section when cut by a plane perpendicular to the optical axis A1 is annular. Figure 3(b) corresponds to a cross-sectional view when the lens barrel 22 is cut by a plane containing the optical axis A1 of the lens 21.

[0091] For example, the lens barrel 22 has an inner diameter D of 5 mm radius and an outer diameter of 6 mm to 9 mm radius, meaning that the thickness (wall thickness) A in the direction perpendicular to the optical axis A1 is 1 mm to 4 mm. In the cross-sectional view shown in Figure 3(b), D and A are the values ​​described above. Furthermore, in this embodiment, no matter which plane the lens barrel 22 is cut on as long as it contains the optical axis A1 of the lens 21, D and A remain constant in the resulting cross-sectional view.

[0092] The material constituting the lens barrel 22 is not particularly limited, but in this case it is aluminum. Furthermore, the surface of the lens barrel 22 is preferably capable of absorbing the wavelength of laser light, and more preferably capable of absorbing both the wavelength of laser light and visible light, in order to suppress stray light, and in this case it is black. More specifically, the surface of the lens barrel 22 may be provided with a black layer by black powder coating, or it may be treated with black anodizing.

[0093] Furthermore, the lens barrel 22 will be explained in more detail using Figures 3 and 4.

[0094] Figure 4 is an enlarged cross-sectional view of the area around the lens barrel 22 according to this embodiment. For simplicity, the lens 21 is omitted in Figure 4.

[0095] Here, the surface of the lens barrel 22 facing the object X (top surface) is referred to as the first surface 221. In a cross-sectional view when the lens barrel 22 is cut along the plane containing the optical axis A1 of the lens 21, the first surface 221 includes a first inclined portion 222 that slopes away from the lens cover 30 as it moves away from the optical axis A1. Note that this cross-sectional view means viewing a plane that includes the optical axis A1 and is perpendicular to the light-receiving surface (top surface) of the image sensor 23. Thus, the first surface 221 includes a first inclined portion 222 that slopes downward as it moves away from the optical axis A1. More specifically, the first inclined portion 222 is formed over the entire first surface 221. In the cross-sectional view shown in Figure 3(b), when the lens barrel 22 is cut along the plane containing the optical axis A1 of the lens 21, the first inclined portion 222 is linear. In this embodiment, the first inclined portion 222 is linear in the cross-sectional view obtained by cutting the lens barrel 22 on any plane that includes the optical axis A1 of the lens 21. However, it is not limited to this, and the first inclined portion 222 may be formed on a part of the first surface 221. Furthermore, since the first surface 221 includes the first inclined portion 222, it can be said that the first surface 221 is macroscopically inclined. Macroscopically inclined means to the extent that the inclination is visible to the naked eye.

[0096] As shown in Figure 4, the inclination angle, which is the angle between the first inclined portion 222 and the plane perpendicular to the optical axis A1 (i.e., the xy-plane), is β. A larger β is better, but if it is too large, the thickness of the tip of the lens barrel 22 will be insufficient and the structure will become weak, so 80 degrees or less is preferable. In this embodiment, β is preferably between 10 degrees and 80 degrees, more preferably between 30 degrees and 70 degrees, and even better between 45 degrees and 60 degrees. Furthermore, no matter which plane the lens barrel 22 is cut on as long as it contains the optical axis A1 of the lens 21, the first inclined portion 222 is linear in the resulting cross-sectional view, and β is constant in any cross-sectional view.

[0097] Furthermore, the first surface 221 is a light-diffusing reflecting surface that diffuses (scatters) the laser light. For example, the full width at half maximum (FWHM) of the laser light scattering angle at the first surface 221 is 45 degrees or more. The FWHM of the light scattering angle refers to the angle between the direction in which light with half the intensity of the light reflected from the front is reflected when light incident from the front is diffusely reflected, and the front direction. In uniform diffuse reflection, the FWHM of the light intensity is 60 degrees.

[0098] The full width at half maximum (FWHM) of the laser light scattering angle on the first surface 221 should be between 45 degrees and 60 degrees, and preferably between 50 degrees and 60 degrees. If the FWHM of the laser light scattering angle on the first surface 221 is within the above range, the first surface 221 can sufficiently diffuse (scatter) the laser light.

[0099] Furthermore, as shown in Figure 4, the image sensor 23 is surrounded by the inner surface 223 of the lens barrel 22.

[0100] Furthermore, as shown in Figure 3, the lens 21 is supported by the lens barrel 22. For example, the lens 21 may be mounted so that its plane is in contact with the upper end of the lens barrel 22 (the upper end of the first surface 221), or the lens 21 may be housed and fixed in a cylindrical cavity inside the lens barrel 22.

[0101] Next, the lens cover 30 will be described. The lens cover 30 is a plate-shaped component located between the lens module 20 and the object X, and has a thickness of 1 mm. The lens cover 30 is provided so as to cover the light source 10 and the lens module 20. The lens cover 30 only needs to be transparent to the wavelength of laser light (i.e., wavelengths in the infrared region).

[0102] The lens cover 30 has a transmittance of 60% or more, more preferably 80% or more, and even better 90% or more, but is not limited to these values. Furthermore, the lens cover 30 has a transmittance of 50% or less, more preferably 30% or less, and even better 10% or less, but is not limited to these values, for wavelengths in the visible light region. Because the transmittance of the lens cover 30 for wavelengths in the visible light region is within the above range, the inside of the 3D distance measuring module 1 cannot be seen by people in the vicinity when the 3D distance measuring module 1 is in use. Therefore, it is expected that the appearance of the 3D distance measuring module 1 will be improved and the person using it will not be subjected to the stress of feeling like they are being monitored.

[0103] Such a lens cover 30 is made of, for example, PMMA (acrylic resin). In this case, the transmittance of the lens cover 30 is 92% for the wavelengths of laser light (here, 850 nm and 940 nm), and the transmittance is 1% or less for wavelengths in the visible light region. The lens cover 30 also has a third surface 31 which is the lower surface facing the lens module 20 and a fourth surface which is the upper surface facing the object X, and it is preferable that a light reflection suppression film is provided on each of the third surface 31 (the lower surface) and the fourth surface (the upper surface). For example, the frontal reflectance of the two light reflection suppression films with respect to the wavelength of laser light is 1% or less. The material constituting the lens cover 30 is not limited to the above, and may be glass, for example. Also, the half-width of the light scattering angle of the laser light on the third surface 31 is 7 degrees or less.

[0104] Furthermore, in this embodiment, since the third surface 31 of the lens cover 30 is a surface parallel to the xy plane, the angle between the first inclined portion 222 and the third surface 31 is the same as β described above.

[0105] The light source 10 and lens module 20 are arranged inside the housing, which is composed of the lens cover 30, the housing side portion 53, and the housing bottom portion 54. For example, the dimensions of the housing, which is composed of the lens cover 30, the housing side portion 53, and the housing bottom portion 54, are 84 mm (x-axis direction) × 40 mm (y-axis direction) × 30 mm (z-axis direction).

[0106] The housing bottom portion 54 is a substrate on which the lens module 20 is mounted. As shown in Figure 3, the lens module 20 and the control unit 60 are mounted in contact with the upper part of the housing bottom portion 54, which is the substrate. It can also be said that the image sensor 23 is stacked on top of the housing bottom portion 54. Thus, the housing bottom portion 54 is a mounting substrate for mounting the lens module 20. A black resist is provided on the surface of the housing bottom portion 54 on which the lens module 20 is mounted, and the frontal reflectance of this surface with respect to the wavelength of laser light is 10% or less. The housing bottom portion 54 is made of glass epoxy material, but is not limited to this.

[0107] The housing side portion 53 is provided adjacent to the upper part of the housing bottom portion 54 and, when viewed from above, is arranged to surround the light source 10 and the lens module 20. In other words, when viewed from above, the housing side portion 53 has a rectangular frame shape. The material constituting the housing side portion 53 is not particularly limited, but in this case it is aluminum. Furthermore, the surface of the housing side portion 53 may be provided with a black layer by black powder coating, or it may be treated with black anodizing.

[0108] The substrate 40 is an example of a component having an opening 41 that encloses the lens 21 when the lens 21 is viewed from the lens cover 30 in the direction of the optical axis A1 of the lens 21, that is, when viewed from above. The substrate 40 has a second surface 42 which is the upper surface facing the lens cover 30 and a lower surface which is facing the bottom surface 54 of the housing.

[0109] In this embodiment, the shape of the aperture 41 is circular when viewed from above, but is not limited to this. The diameter of the aperture 41 should be large enough to enclose the lens 21 and large enough to enclose the lens module 20. For example, the diameter of the aperture 41 should be 10 mm or less, which is larger than the outer diameter of the lens barrel 22.

[0110] The substrate 40 is a substrate component on which the light source 10 is mounted. As shown in Figure 3, the light source 10 is mounted in contact with the upper part of the substrate 40. In other words, the substrate 40 is a mounting substrate for mounting the light source 10. A dark blue resist is provided on the surface of the substrate 40 on which the light source 10 is mounted. The substrate 40 is made of glass epoxy material, but is not limited to this. The substrate 40 is also held in place by a substrate holder 52.

[0111] The substrate holder portion 52 is provided in contact with the upper part of the housing bottom portion 54 and is a member that supports the substrate 40 in contact with the lower surface of the substrate 40.

[0112] The substrate holder 52 has a rectangular frame shape when viewed from above and supports the edges of the substrate 40. The material constituting the substrate holder 52 is not particularly limited, but in this case it is aluminum. The surface of the substrate holder 52 is also provided with a black layer by black powder coating.

[0113] The light-shielding member 51 is a member provided in contact with the upper part of the substrate 40. The light-shielding member 51 is provided between the light source 10 and the lens module 20. In the top view shown in Figure 3(a), the light-shielding member 51 is an elongated rectangular member. The material constituting the light-shielding member 51 is not particularly limited, but in this case it is aluminum. The surface of the light-shielding member 51 is provided with a black layer made of black powder coating.

[0114] The light-shielding member 51 is a member that prevents laser light emitted from the light source 10 from reaching the image sensor 23 by reflection inside the 3D distance measuring module 1 (that is, inside the housing composed of the lens cover 30, the housing side portion 53, and the housing bottom portion 54). As shown in Figure 3, the inside of the 3D distance measuring module 1 (that is, inside the housing) is separated into two spaces by the light-shielding member 51, the substrate 40, and the substrate holder portion 52. The lens module 20 and the control unit 60 are located in one of the two spaces, and the light source 10 is located in the other space.

[0115] Furthermore, Figure 5 will be used to explain the behavior of the laser light when the laser light emitted from the light source 10 is reflected by the object X.

[0116] Figure 5 is a cross-sectional view showing the behavior of laser light according to this embodiment. Note that the cross-sectional view shown in Figure 5 corresponds to the cross-sectional view in Figure 3(b).

[0117] Furthermore, the light reflected by the object X from the laser beam emitted from the light source 10 is described as reflected light L. In Figure 5, one of the two reflected light beams L shown in Figure 5 overlaps with the optical axis A1 shown in Figure 3, etc., so the optical axis A1 is omitted. In subsequent drawings as well, the optical axis A1 may be omitted for the same reason.

[0118] As shown in Figure 5, let H be the distance from the center 211 of the lens 21 to the third surface 31, which is the lower surface of the lens cover 30. In other words, H is the length in the z-axis direction from the plane of the lens 21 to the third surface 31.

[0119] As explained above in (Knowledge leading to one aspect of this disclosure), when the object X has a highly reflective surface, the object X is observed as a bright spot by the image sensor 23. In other words, the object X corresponds to a bright spot. In Figure 5, the object X (bright spot) is located in the direction of the optical axis A1 (z-axis direction). More specifically, the direction connecting the object X and the image sensor 23 is parallel to the direction of the optical axis A1 (z-axis direction).

[0120] The following two reflected light sources L will be explained.

[0121] First, one of the two reflected light rays L enters the lens 21 of the lens module 20 through the lens cover 30 and forms an image at a single point on the image sensor 23.

[0122] Furthermore, one of the two reflected light rays L does not directly enter the lens 21, but is reflected (scattered) by the first surface 221 of the lens barrel 22, re-reflected by the third surface 31 of the lens cover 30, enters the lens 21, and forms an image at another point on the image sensor 23. At this other point, an intense flare light is generated. The angle between the direction in which the other of the two reflected light rays L propagates and the optical axis A1 direction (z-axis direction) is θ. In other words, the angle of incidence of the other of the two reflected light rays L to the image sensor 23 is θ.

[0123] Furthermore, the intensity of this flare light (hereinafter referred to as flare light intensity) is calculated using the following method.

[0124] As described above, the object X (bright spot) is located in the direction of the optical axis A1 (z-axis direction). The amount of flare light is proportional to (area of ​​the first surface 221 of the lens barrel 22) / (area of ​​the lens 21 when viewed from above × reflectance of the first surface 221 × reflectance of the third surface 31), with respect to one of the two reflected lights L described above.

[0125] As described above, the inclination angle of the first inclined portion 222 is β. The first surface 221 is a light-diffusing reflective surface that diffuses (scatters) the laser light.

[0126] Furthermore, let R1 be the frontal reflectance of the first surface 221, and R2 be the frontal reflectance of the third surface 31. For example, R1 of the first surface 221 is 1%.

[0127] As shown in Figure 5, one of the two reflected rays L reaches the first surface 221. At this time, the angle of incidence is β. The light that reaches the first surface 221 is diffusely reflected. Furthermore, the light diffusely reflected at an angle of reflection of θ+β is reflected again by the third surface 31, passes through the lens 21, and is incident on the image sensor 23. As described above, the angle of incidence of the light reflected by the third surface 31 to the image sensor 23 is θ.

[0128] Here, the amount of flare light is expressed by equation (1).

[0129]

number

[0130] Equation (1) is based on an empirical approximation for diffuse reflection with a full width at half maximum of 45 degrees when light is incident at an oblique angle of incidence β.

[0131] Furthermore, when θ is small, the light reflected by the third surface 31 may be reflected again by the first surface 221 (more specifically, the first surface 221 on the positive x-axis side as shown in Figure 5) and may not reach the lens 21. This is what is known as the light being obscured by the first surface 221 of the lens barrel 22. The amount of flare light corresponding to the case where θ in equation (1) is smaller than θ1 that satisfies equation (2) is subtracted from the amount of flare light calculated in equation (1).

[0132]

number

[0133] Furthermore, when θ is large, the light reflected by the third surface 31 may be reflected again by the first surface 221 (more specifically, the first surface 221 on the negative x-axis side as shown in Figure 5) and may not reach the lens 21. This is also a state in which the light is obscured by the first surface 221 of the lens barrel 22. The amount of flare light corresponding to the case where θ in equation (1) is greater than θ2 that satisfies equation (3) is subtracted from the amount of flare light calculated in equation (1).

[0134]

number

[0135] As described above, the amount of flare light is calculated. Next, we will examine the effect on the amount of flare light when the inclination angle β of the first inclined section 222 is changed.

[0136] Figure 6 shows the effect on the amount of flare light when the inclination angle of the first inclined section 222 according to this embodiment is changed.

[0137] In Figure 6, the flare light intensity is calculated for the three-dimensional distance measuring modules according to the first, second, third, and fourth embodiments, which correspond to the three-dimensional distance measuring module 1 according to this embodiment, with β values ​​of 15, 30, 45, and 60 degrees, respectively. The three-dimensional distance measuring module with β value of 0 degrees shown in Figure 6 is the three-dimensional distance measuring module according to the first study example and does not correspond to the three-dimensional distance measuring module 1 according to this embodiment. The three-dimensional distance measuring module according to the first study example has the same configuration as the three-dimensional distance measuring module 1 according to this embodiment, except that β is 0 degrees, meaning the first surface 221 is parallel to the xy plane.

[0138] Furthermore, Figure 6(a) shows the amount of flare light when the incident angle θ is changed for the 3D distance measuring modules relating to the first to fourth embodiments and the first study example. Figure 6(b) is a distance image when β is 0 degrees. Also in Figure 6(b), an object X that is closer to the 3D distance measuring module 1 and an object Y that is further away from the 3D distance measuring module 1 are shown. As explained in (Knowledge leading to obtaining one aspect of this disclosure), object X has a high reflectivity surface.

[0139] When β is 0 degrees, that is, in the 3D ranging module related to the first example, the flare light quantity exhibits the following behavior.

[0140] When θ is between 0 and 27 degrees, that is, when it is smaller than θ1 satisfying equation (2), the amount of flare increases mainly because the reflected light L is less likely to be blocked by the first surface 221 of the telescope tube 22 as θ increases.

[0141] When θ is between 27 and 68 degrees, the reflected light L is not blocked by the first surface 221 of the telescope tube 22. However, as θ increases, the diffuse reflectance decreases, and the amount of flare decreases.

[0142] When θ is between 68 degrees and 72 degrees, that is, when it is greater than θ2 satisfying equation (3), the amount of flare decreases mainly because the reflected light L is more often blocked by the first surface 221 of the telescope tube 22.

[0143] Furthermore, when θ is an angle greater than or equal to half the angle of view of the lens 21, the reflected light L does not form an image on the image sensor 23, so the amount of flare light is below the detection limit. As mentioned above, half the angle of view is half the angle of view that the image sensor 23 can capture, and in this embodiment it is 70 degrees.

[0144] Furthermore, the behavior of flare intensity is similar regardless of the value of β. In other words, as θ increases from 0 degrees, the flare intensity initially increases, then decreases, and when θ becomes sufficiently large, the flare intensity falls below the detection limit.

[0145] Furthermore, a comparison is made between the 3D distance measuring module according to the first study example, in which the first surface 221 does not include the first inclined portion 222 (i.e., β is 0 degrees), and the 3D distance measuring modules according to the first to fourth embodiments, in which the first surface 221 includes the first inclined portion 222 (i.e., β is 15 degrees or more). Compared to the 3D distance measuring module according to the first study example, in which the first surface 221 does not include the first inclined portion 222, the 3D distance measuring modules according to the first to fourth embodiments, in which the first surface 221 includes the first inclined portion 222, show a reduction in flare light intensity.

[0146] Furthermore, it has been shown that the larger β is, the lower the flare intensity. In the distance image shown in Figure 6(b), an annular intensity flare region was observed, but as shown in Figure 6(a), increasing β results in a distance image in which the occurrence of the intensity flare region is suppressed. Also, the larger β is, the smaller the angle indicating the peak value of the flare intensity.

[0147] Furthermore, the distance between the 3D ranging module 1 and object X, and the distance between the 3D ranging module 1 and object Y when high-intensity flare light is generated will be explained using Figure 7.

[0148] Figure 7 shows the relationship between the distance between the 3D ranging module 1 and object X, and the distance between the 3D ranging module 1 and object Y, according to this embodiment. For calculation purposes, it is assumed that the reflectances of object X and object Y are the same.

[0149] In Figure 7, the vertical axis represents the distance between the 3D ranging module 1 and object Y divided by the distance between the 3D ranging module 1 and object X (distance ratio), and the horizontal axis represents the angle of incidence, θ.

[0150] In this case, if the value on the vertical axis is larger than the curve corresponding to the value of β shown in Figure 7, it means that the amount of flare light based on the reflected light L from object X is greater than the amount of light that is reflected by object Y and directly incident on lens 21 and image sensor 23. In other words, if the value on the vertical axis is larger than the curve corresponding to the value of β shown in Figure 7, it means that a miscalculation of distance has occurred.

[0151] As shown in Figure 7, the larger β is, the narrower the range in which miscalculations occur. In other words, compared to the 3D distance measuring module according to the first study example in which the inclination angle β of the first inclined section 222 is 0 degrees, the 3D distance measuring modules according to the first to fourth embodiments in which the inclination angle β of the first inclined section 222 is larger can suppress the occurrence of miscalculations of distance.

[0152] Furthermore, if we consider the object Y to be, for example, the sky (up in the air), and the distance between the 3D ranging module 1 and object Y to be infinite, then, because the distance between the 3D ranging module 1 and object Y is infinite, a miscalculation of the distance will occur if the amount of flare light exceeds the detection limit.

[0153] The above explanation described the case where the object X (bright spot) is located in the direction of the optical axis A1 (z-axis direction). Here, we will further explain the case where the direction connecting the object X (bright spot) and the 3D ranging module 1 is positioned at an angle to the direction of the optical axis A1 (z-axis direction), using Figure 8.

[0154] Figure 8 is a cross-sectional view showing other behaviors of the laser light according to this embodiment. Note that the cross-sectional view shown in Figure 8 corresponds to the cross-sectional view in Figure 3(b).

[0155] Here, the direction connecting the object X (bright spot) and the 3D ranging module 1 is positioned at an angle with the optical axis A1 direction (z-axis direction). More specifically, the angle between the direction connecting the object X and the image sensor 23 and the optical axis A1 direction (z-axis direction) is α.

[0156] The following two reflected light sources L will be explained.

[0157] First, one of the two reflected light beams L enters the lens module 20 through the lens cover 30 and directly enters the lens 21, forming an image at a single point on the image sensor 23. At this time, the angle of incidence is α.

[0158] Furthermore, one of the two reflected light beams L does not directly enter the lens 21 but reaches the first surface 221. At this time, the angle of incidence is β-α. The light that reaches the first surface 221 is diffusely reflected. The light that has been diffusely reflected with a reflection angle of θ+β is further reflected by the third surface 31, passes through the lens 21, and enters the image sensor 23. The angle of incidence of the light reflected by the third surface 31 to the image sensor 23 is θ.

[0159] Here, using the same method as that used to calculate Figure 6(a), we will examine the effect of changes in the values ​​of α and β on the amount of flare light, using Figures 9 to 12.

[0160] Figures 9 to 12 are other diagrams showing the effect on the amount of flare light when the inclination angle of the first inclined section 222 according to this embodiment is changed.

[0161] Here, as in Figure 6(a), the 3D distance measuring module according to the first to fourth embodiments and the first study example is used. In Figure 9, α is 0 degrees, in Figure 10, α is 15 degrees, in Figure 11, α is 30 degrees, and in Figure 12, α is 45 degrees. Note that Figure 9 is the same figure as Figure 6(a).

[0162] In all of Figures 9 to 12, the behavior of the flare intensity is similar regardless of the value of β. That is, the flare intensity initially increases as θ increases from 0 degrees, then decreases, and when θ becomes sufficiently large, the flare intensity falls below the detection limit. As shown in Figures 9 to 12, it became clear that the effect of changing the value of α on the flare intensity is small.

[0163] Next, we will examine the effect of changing the thickness A of the telescope tube 22 on the amount of flare light, using Figure 13.

[0164] Figure 13 is another figure showing the effect on the amount of flare light when the inclination angle of the first inclined section 222 according to this embodiment is changed.

[0165] Here, we examine the effect of changes in the values ​​of A and β on the amount of flare light, using the same method as in Figure 6(a) where the values ​​were calculated. Also, as in Figure 6(a), the 3D distance measuring module related to the first to fourth embodiments and the first study example is used. In Figure 13(a), A is 1 mm, in Figure 13(b), A is 2 mm, and in Figure 13(c), A is 4 mm.

[0166] Furthermore, in Figure 13, the dashed-dotted lines and double-dotted lines, which represent approximately the same amount of flare light, are shown spanning Figures 13(a) to (c).

[0167] The greater the thickness A of the telescope tube 22, the larger the angle (θ) that indicates the peak value of the flare light. In other words, the greater the thickness A of the telescope tube 22, the further the intensity of the flare light is generated from the optical axis A1.

[0168] As shown in Figure 13, the larger β is, the smaller the effect on the flare intensity even when A, which is the thickness of the telescope tube 22, changes. When β is 30 degrees or more, the effect on the flare intensity is sufficiently small even when A changes, and when β is 45 degrees or more, the effect on the flare intensity is almost negligible even when A changes.

[0169] Furthermore, when comparing identical 3D distance measuring modules, the flare intensity is approximately the same for the same θ in the range where θ is 0 degrees or greater and less than or equal to the angle that shows the peak value of the flare intensity. For example, in the 3D distance measuring module according to the first embodiment where β is 15 degrees, the flare intensity is approximately the same regardless of the value of A, specifically around 7 to 8.

[0170] Furthermore, as described above, in the cross-sectional view obtained by cutting the lens barrel 22 with respect to the plane containing the optical axis A1 of the lens 21, the first inclined portion 222 is linear. The effect of the first inclined portion 222 being linear will be explained using Figures 14 to 16.

[0171] Figures 14 to 16 are diagrams illustrating the effect of the linearity of the first inclined portion 222 according to this embodiment. More specifically, Figures 14 to 16(a) are enlarged cross-sectional views showing parts of the lens 21 and lens barrel 22, respectively. Figures 14 to 16(b) are diagrams showing the effect on the amount of flare light when the inclination angle of the first inclined portion 222 is changed, and the same method used to calculate Figure 6(a) is employed. Also, as with Figure 6(a), the 3D distance measuring module according to the first to fourth embodiments and the first study example is used. Note that in all of Figures 14 to 16(b), the amount of flare light is calculated assuming that the inner diameter D is 5 mm, the thickness A is 2 mm, and the distance H is 2 mm.

[0172] Figures 14 through 16 each show five examples where the value of β has been changed.

[0173] Figure 14 describes the three-dimensional distance measuring module according to the first to fourth embodiments and the first study example. Specifically, Figure 14 shows a three-dimensional distance measuring module in which the first inclined portion 222 is linear in a cross-sectional view.

[0174] Figure 15 shows five examples of 3D distance measuring modules according to the first to fourth embodiments and the first study example, in which the first surface 221, which is the surface (top surface) of the lens barrel 22 facing the object X, is concave (curved and concave in the negative z-axis direction).

[0175] In Figure 15, the inclination angle of the first surface 221 increases as you move from the outside of the lens barrel 22 towards the lens 21. At the outer end of the lens barrel 22, the inclination angle of the first surface 221 is 0 degrees. Furthermore, at the first surface 221, the inclination angle β is the angle between the direction connecting the lens 21 side end of the lens barrel 22 (i.e., the inside of the lens barrel 22) and the outer end of the lens barrel 22 and the plane perpendicular to the optical axis A1 (i.e., the xy plane). The inclination angle at a predetermined point on the first surface 221 is proportional to the distance between that predetermined point and the outer end of the lens barrel 22. Therefore, in the first example of consideration, when β is 0 degrees, the first surface 221 is a straight line.

[0176] Figure 16 shows five examples of 3D distance measuring modules relating to the first to fourth embodiments and the first study example, in which the first surface 221, which is the surface (top surface) of the lens barrel 22 facing the object X, is convex (a shape that curves and protrudes in the positive z-axis direction).

[0177] In Figure 16, the inclination angle of the first surface 221 decreases as you move from the outside of the lens barrel 22 towards the lens 21. At the inner end of the lens barrel 22, the inclination angle of the first surface 221 is 0 degrees. Furthermore, at the first surface 221, the inclination angle β is the angle between the direction connecting the lens 21 side end of the lens barrel 22 (i.e., the inner end of the lens barrel 22) and the outer end of the lens barrel 22, and the plane perpendicular to the optical axis A1 (i.e., the xy plane). The inclination angle at a predetermined point on the first surface 221 is proportional to the distance between that predetermined point and the inner end of the lens barrel 22. Therefore, in the first example of consideration, when β is 0 degrees, the first surface 221 is a straight line.

[0178] As shown in Figures 14 to 16(b), in the range where β is between 15 degrees and 60 degrees, the 3D distance measuring module in which the first inclined portion 222 is linear in the cross-sectional view, as shown in Figure 14, can suppress the amount of flare light compared to the examples shown in Figures 15 and 16.

[0179] [Manufacturing method] Here, we will briefly describe the manufacturing method of the 3D distance measuring module 1 according to this embodiment.

[0180] First, the lens 21 is connected to the lens barrel 22. The lens barrel 22 and lens 21 are installed above the image sensor 23 on the bottom surface 54 of the housing where the image sensor 23 and control unit 60 are installed (mounted).

[0181] Furthermore, the light source 10 is installed (mounted) on the substrate 40. The substrate 40 is aligned so that the position of the opening 41 on the substrate 40 coincides with the positions of the lens barrel 22 and the lens 21, and the substrate 40 is installed on the bottom surface 54 of the housing via the substrate holder 52, and the wiring is connected. Furthermore, the light shielding member 51 is installed. Finally, the lens cover 30 is installed on the bottom surface 54 of the housing via the side surface 53 of the housing.

[0182] [Effects, etc.] The three-dimensional distance measuring module 1 according to this embodiment includes a light source 10, a lens module 20, and a lens cover 30. The light source 10 emits laser light. The lens module 20 includes a lens 21 that focuses the light reflected by the object from the emitted laser light, an image sensor 23 that receives the light focused by the lens 21, and a lens barrel 22 that encloses the space between the lens 21 and the image sensor 23 and supports the lens 21. The lens cover 30 is located between the lens module 20 and the object and is transparent to the wavelength of the laser light. In a cross-sectional view when the lens barrel 22 is cut along a plane containing the optical axis A1 of the lens 21, the first surface 221 of the lens barrel 22 facing the object includes a first inclined portion 222 that inclins away from the lens cover 30 as it moves away from the optical axis A1.

[0183] As a result, when laser light reflected by an object X corresponding to a bright spot is reflected by the first surface 221 (first inclined portion 222), the amount of light (intensity flare light) reaching the lens 21 and image sensor 23 is suppressed. For example, as explained in Figure 6(a), we compare a 3D distance measuring module according to the first study example in which the first surface 221 does not include the first inclined portion 222 (i.e., β is 0 degrees) with a 3D distance measuring module according to the first to fourth embodiments in which the first surface 221 includes the first inclined portion 222 (i.e., β is 15 degrees or more). Compared to the 3D distance measuring module according to the first study example in which the first surface 221 does not include the first inclined portion 222, the amount of flare light is reduced in the 3D distance measuring modules according to the first to fourth embodiments in which the first surface 221 includes the first inclined portion 222. The 3D distance measuring modules according to the first to fourth embodiments correspond to the 3D distance measuring module 1 according to this embodiment. In this way, the amount of high-intensity flare light reaching the lens 21 and the image sensor 23 is suppressed, making it possible to realize a 3D distance measuring module 1 in which the occurrence of distance miscalculations is suppressed.

[0184] Furthermore, the first inclined portion 222 is formed over the entire surface 221.

[0185] As a result, when laser light reflected by an object X corresponding to a bright spot is reflected by the first surface 221 (first inclined portion 222), the laser light is more likely to be reflected from the first surface 221 (first inclined portion 222) in the direction opposite to the lens 21 and image sensor 23. In other words, the amount of intensity flare light reaching the lens 21 and image sensor 23 is further suppressed, making it possible to realize a 3D distance measuring module 1 in which the occurrence of distance miscalculations is further suppressed.

[0186] Furthermore, the half-width of the light scattering angle of the laser beam on the first surface 221 is 45 degrees or more.

[0187] As a result, the laser light reflected by the object X corresponding to the bright spot is diffusely reflected by the first surface 221 (first inclined portion 222). Therefore, the light (intensity flare light) reaching the lens 21 and image sensor 23 is further suppressed. In other words, since the amount of intensity flare light reaching the lens 21 and image sensor 23 is further suppressed, a 3D distance measuring module 1 can be realized in which the occurrence of distance miscalculations is further suppressed.

[0188] Furthermore, in the cross-sectional view described above, the angle between the first inclined portion 222 and the surface of the lens cover 30 facing the lens module 20 is 30 degrees or more.

[0189] This ensures that the angle between the first inclined portion and the surface of the lens cover facing the lens module becomes sufficiently large. For example, as explained in Figure 6(a), the larger β is, the less flare light there is. When β is 30 degrees or more, the light (intensity flare light) reaching the lens 21 and the image sensor 23 is further suppressed. In other words, since the amount of intensity flare light reaching the lens 21 and the image sensor 23 is further suppressed, a 3D distance measuring module 1 can be realized that further suppresses the occurrence of distance miscalculations.

[0190] Furthermore, as explained in Figure 13, when β is 30 degrees or greater, the effect on the flare intensity is sufficiently small even if A changes, and when β is 45 degrees or greater, the effect on the flare intensity is almost negligible even if A changes. This increases the design flexibility of the shape of the telescope tube 22.

[0191] Furthermore, in the cross-sectional view described above, the first inclined portion 222 is linear.

[0192] As a result, as shown in Figures 14 to 16, the amount of intensity flare light reaching the lens 21 and image sensor 23 is suppressed more than when the first inclined portion 222 is curved, thus enabling the realization of a 3D distance measuring module 1 in which the occurrence of distance miscalculations is further suppressed.

[0193] Furthermore, the 3D distance measuring system 100 includes the 3D distance measuring module 1 described above, and the 3D distance measuring module 1 has a calculation unit 63 that calculates the distance from the light source 10 to the object based on the travel time of the laser beam.

[0194] Since the above-mentioned 3D distance measuring module 1 can suppress the occurrence of distance miscalculations, a 3D distance measuring system 100 equipped with such a 3D distance measuring module 1 can suppress the occurrence of distance miscalculations.

[0195] (Modification 1 of Embodiment 1) Next, Modification 1 of Embodiment 1 will be described. In Modification 1 of Embodiment 1, the shapes of the lens barrel 22a and the aperture 41a differ from those of Embodiment 1. In the following, the differences from Embodiment 1 will be explained in detail, and the explanation of the common points will be omitted or simplified.

[0196] [composition] A configuration example of the 3D distance measuring module 1a according to a modified example 1 of Embodiment 1 will be explained with reference to Figure 17.

[0197] Figure 17 shows a top view and two cross-sectional views of the three-dimensional distance measuring module 1a according to this modified example.

[0198] More specifically, Figure 17(a) is a top view of the 3D ranging module 1a, Figure 17(b) is a cross-sectional view of the 3D ranging module 1a along the line XVIIb-XVIIb in Figure 17(a), and Figure 17(c) is a cross-sectional view of the 3D ranging module 1a along the line XVIIc-XVIIc in Figure 17(a).

[0199] The three-dimensional distance measuring module 1a according to this modified example has the same configuration as the three-dimensional distance measuring module 1 according to Embodiment 1, except that it includes a lens module 20a instead of a lens module 20, and a substrate 40a instead of a substrate 40.

[0200] The lens module 20a has the same configuration as the lens module 20, except that it has a lens barrel 22a instead of a lens barrel 22.

[0201] The telescope tube 22a has the same configuration as the telescope tube 22, except for its shape.

[0202] The lens barrel 22a has a bottomless cylindrical shape and is rectangular in shape. A cylindrical cavity is formed inside the lens barrel 22a. The lens barrel 22a extends along the optical axis A1 of the lens 21, and the optical axis A1 of the lens 21 and the axis of the lens barrel 22a coincide. As described above, since the lens barrel 22a is rectangular in shape, the cross-section when cut with a plane perpendicular to the optical axis A1 has a rectangular outer shape, and the part corresponding to the cylindrical cavity is circular. In other words, in the top view shown in Figure 17(a), that is, when viewed from the direction of the optical axis A1, the outer shape of the lens barrel 22a is rectangular and similar in shape to the outer shape of the image sensor 23.

[0203] Here, the surface (top surface) of the lens barrel 22a facing the object X is defined as the first surface 221a. In a cross-sectional view when the lens barrel 22a is cut along the plane containing the optical axis A1 of the lens 21, the first surface 221a includes a first inclined portion 222a that slopes away from the lens cover 30 as it moves away from the optical axis A1. In other words, the first surface 221a includes a first inclined portion 222a that slopes downward as it moves away from the optical axis A1. More specifically, the first inclined portion 222a is formed over the entire first surface 221a. In the cross-sectional view shown in Figure 17(b), when the lens barrel 22a is cut along the plane containing the optical axis A1 of the lens 21, the first inclined portion 222a is linear. In this modified example, the first inclined portion 222a is linear in the cross-sectional view obtained by cutting the lens barrel 22a along any plane containing the optical axis A1 of the lens 21. However, the invention is not limited to this, and a first inclined portion 222a may be formed on a part of the first surface 221a.

[0204] As shown in Figure 4, the inclination angle, which is the angle between the first inclined portion 222a and the plane perpendicular to the optical axis A1 (i.e., the xy-plane), is β. In this modified example, β is preferably between 10 degrees and 80 degrees, more preferably between 30 degrees and 70 degrees, and even better between 45 degrees and 60 degrees.

[0205] Substrate 40a has the same configuration as substrate 40, except that it has an opening 41a instead of an opening 41.

[0206] In this modified example, the shape of the aperture 41a is rectangular when viewed from above. When viewed from above, the aperture 41a is large enough to enclose the lens 21 and the lens barrel 22a, and it is also large enough to enclose the lens module 20a.

[0207] Furthermore, using Figure 18, the inclination angle of the first inclined portion 222a of the first surface 221a will be explained.

[0208] Figure 18 is a top view of the lens barrel 22a and lens 21 according to this modified example, as well as a cross-sectional view of the lens barrel 22a.

[0209] More specifically, Figure 18(a) is a top view of the lens barrel 22a and lens 21, Figure 18(b) is a cross-sectional view of the lens barrel 22a along the line XVIIIb-XVIIIb in Figure 18(a), Figure 18(c) is a cross-sectional view of the lens barrel 22a along the line XVIIIc-XVIIIc in Figure 18(a), and Figure 18(d) is a cross-sectional view of the lens barrel 22a along the line XVIIId-XVIIId in Figure 18(a).

[0210] As described above, when viewed from the direction of the optical axis A1, the outer shape of the lens barrel 22a is rectangular and similar in shape to the outer shape of the image sensor 23. At this time, the degree of inclination of the first inclined portion 222a from a plane perpendicular to the optical axis A1 is represented by the inclination angle β of the first inclined portion 222a. This degree of inclination (i.e., β) has a positive correlation with the distance between the optical axis A1 and the outer end of the lens barrel 22a. In other words, in a top view, the β of the first inclined portion 222a in the direction connecting the optical axis A1 and a point on the outer end of the lens barrel 22a has a positive correlation with the distance between the optical axis A1 and the outer end of the lens barrel 22a.

[0211] Here, the positive y-axis direction is defined as the reference direction. Let δ be the angle between this reference direction and the lines XVIIIb-XVIIIb and XVIIIc-XVIIIc, respectively.

[0212] For example, in Figure 18(b), δ is 0, A, which is the thickness of the telescope tube 22a, is 1 mm, β is 15 degrees, and the half-angle of view is 14 degrees.

[0213] For example, in Figure 18(c), δ is greater than 0, A, which is the thickness of the telescope tube 22a, is 4 mm, β is 30 degrees, and the half-angle of view is 30 degrees.

[0214] Thus, in Figure 18(c) A is larger than in Figure 18(b), meaning the distance between the optical axis A1 and the outer end of the telescope tube 22a is larger. For this reason, β is larger in Figure 18(c) than in Figure 18(b). Also, in the cross-sectional view shown in Figure 18(d), the first surface 221a is curved convexly in the positive z-axis direction.

[0215] Figure 19 shows the relationship between δ and β in this modified example. As δ changes, A changes. In other words, the distance between the optical axis A1 and the outer end of the lens barrel 22a changes. Consequently, the value of β also changes.

[0216] Here, we will again use Figures 13(a) and (c) of Embodiment 1 for explanation. Figure 13 shows that the thicker A of the telescope tube 22, the higher the flare light intensity, and the angle (θ) indicating the peak value of the flare light intensity shifts to a higher angle. Furthermore, as β increases, the flare light intensity decreases.

[0217] In this modified example, when viewed from above (i.e., in the top view), the outer shape of the lens barrel 22a is similar to the outer shape of the image sensor 23, and the degree of inclination (β) of the first inclined portion 222a from the plane perpendicular to the optical axis A1 has a positive correlation with the distance between the optical axis A1 and the outer end of the lens barrel 22a. In other words, in this modified example, β increases according to A, which is the thickness of the lens barrel 22a. Considering the relationship between A and β shown in Figure 13, as β increases with A, the angle (θ) at which intense flare light is generated can be increased while the peak value of the flare light is kept constant. That is, the angle at which intense flare light is generated can be moved outside the field of view. As a result, the amount of flare light is suppressed uniformly within the plane, and the occurrence of distance miscalculations is suppressed.

[0218] [Effects, etc.] In the three-dimensional distance measuring module 1a according to this modified example, the outer shape of the lens barrel 22a is similar to the outer shape of the image sensor 23 when viewed from the direction of the optical axis A1. The degree of inclination of the first inclined portion 222a from a plane perpendicular to the optical axis A1 has a positive correlation with the distance between the optical axis A1 and the outer end of the lens barrel 22a.

[0219] As shown in Figure 13, the thicker the lens barrel 22 (A), the higher the flare light intensity, and the angle (θ) at which the peak value of the flare light intensity is observed shifts to a higher angle. Here, β increases according to the thickness A of the lens barrel 22a. This allows the angle (θ) at which intense flare light is generated to be increased while the peak value of the flare light intensity remains constant. In other words, the angle at which intense flare light is generated can be moved outside the field of view. In this way, the amount of intense flare light reaching the image sensor 23 is suppressed more uniformly within the plane, making it possible to realize a 3D ranging module 1a in which the occurrence of distance miscalculations is uniformly suppressed with respect to angle δ.

[0220] (Modification 2 of Embodiment 1) Next, a modified example of Embodiment 1, Part 2, will be described. In Modified Example 2 of Embodiment 1, the first surface 221b reflects light (so-called specular reflection) while suppressing the occurrence of light diffusion (light scattering), which is a difference from Embodiment 1. In the following, the differences from Embodiment 1 will be explained in detail, and the explanation of the common points will be omitted or simplified.

[0221] A configuration example of the 3D distance measuring module 1b according to a modified example 2 of Embodiment 1 will be explained with reference to Figure 20.

[0222] Figure 20 shows a top view and two cross-sectional views of the 3D distance measuring module 1b according to this modified example.

[0223] More specifically, Figure 20(a) is a top view of the 3D ranging module 1b, and Figure 20(b) is a cross-sectional view of the 3D ranging module 1b along the line XXb-XXb in Figure 20(a). Furthermore, Figure 20(c) is a cross-sectional view of the 3D ranging module 1b along the line XXc-XXc in Figure 20(a).

[0224] The three-dimensional distance measuring module 1b according to this modified example has the same configuration as the three-dimensional distance measuring module 1 according to Embodiment 1, except that it includes a lens module 20b instead of a lens module 20.

[0225] The lens module 20b has the same configuration as the lens module 20, except that it has a lens barrel 22b instead of a lens barrel 22.

[0226] The lens barrel 22b has the same configuration as the lens barrel 22, except that it has a first surface 221b, which is the surface (top surface) of the lens barrel 22b that faces the object X, instead of the first surface 221.

[0227] As described above, the first surface 221 in Embodiment 1 was a light-diffusing reflective surface that diffuses (scatters) the laser light, but the first surface 221b is a reflective surface in which the occurrence of light diffusion (scattering) of the laser light is suppressed, and more specifically, the full width at half maximum of the light scattering angle of the laser light on the first surface 221b is 7 degrees or less. Note that the full width at half maximum of the light scattering angle of the laser light on the first surface 221b only needs to be 7 degrees or less, it is better if it is 5 degrees or less, and even better if it is 3 degrees or less.

[0228] Furthermore, using Figures 21 and 22, we will explain the behavior of the laser light when the laser light emitted from the light source 10 is reflected by the object X.

[0229] Figures 21 and 22 are cross-sectional views showing the behavior of the laser light according to this modified example. The cross-sectional views shown in Figures 21 and 22 correspond to Figure 20(b). As in Embodiment 1, the inclination angle, which is the angle between the first inclined portion 222b and the plane perpendicular to the optical axis A1 (i.e., the xy-plane), is β.

[0230] Furthermore, in Figure 21, the object X (bright spot) is located in the direction of the optical axis A1 (z-axis direction). More specifically, the direction connecting the object X and the image sensor 23 is parallel to the direction of the optical axis A1 (z-axis direction).

[0231] Furthermore, in Figure 22, the direction connecting the object X (bright spot) and the 3D ranging module 1b is positioned at an angle with the optical axis A1 direction (z-axis direction). More specifically, the angle between the direction connecting the object X and the image sensor 23 and the optical axis A1 direction (z-axis direction) is α.

[0232] First, let's explain Figure 21.

[0233] One of the two reflected light rays L enters the lens 21 directly through the lens cover 30 and forms an image at a single point on the image sensor 23.

[0234] Furthermore, one of the two reflected light beams L does not directly enter the lens 21, but reaches the first surface 221b, which includes the first inclined portion 222b. At this time, the angle of incidence is β. The light that reaches the first surface 221b is reflected. The angle of reflection of this reflected light is β. This reflected light does not reach the lens 21, nor does it enter the image sensor 23.

[0235] Thus, when the object X (bright spot) is located in the direction of the optical axis A1 (z-axis direction), no intense flare light is generated.

[0236] Next, we will explain Figure 22. In Figure 22, we will further explain using reflected light L1 and θ3, which is the angle of incidence of the reflected light L1 onto the image sensor 23.

[0237] Reflected light L1 is defined as the light reflected by object Y from the laser beam emitted from light source 10. Furthermore, this reflected light L1 enters the lens 21 directly through the lens cover 30 and forms an image at a single point on the image sensor 23. The angle of incidence of this reflected light L1 to the image sensor 23 is denoted as θ3.

[0238] Furthermore, the reflected light L shown in Figure 22 is light reflected from the object X (bright spot) and reaches the first surface 221b without directly entering the lens 21. At this time, the angle of incidence is α-β. The light that reaches the first surface 221b is reflected at a reflection angle of α-β. Furthermore, the reflected light enters the third surface 31 at an angle of incidence of α-2β, is reflected at a reflection angle of α-2β, passes through the lens 21, and enters the image sensor 23. The point at which this light enters the image sensor 23 is the same point at which the reflected light L1 entered the image sensor 23 (the point mentioned above). In other words, at this point, an intense flare light is generated.

[0239] Furthermore, Figure 22 shows an auxiliary line 80, which is a dashed line passing through the center point of the upper surface of the image sensor 23, where the optical axis A1 passes through the image sensor 23, and the upper end of the lens barrel 22b. The angle between this auxiliary line 80 and the optical axis A1 corresponds to the half-angle of view and is shown as θ4.

[0240] As shown in Figure 22, when α is greater than half the field of view (θ4), an intense flare is generated at that point.

[0241] As shown in Figure 21, in the three-dimensional distance measuring module 1b according to this modified example, the half-width of the light scattering angle of the laser beam on the first surface 221b is 7 degrees or less.

[0242] As a result, the laser light reflected by the object X corresponding to the bright spot is specularly reflected by the first surface 221b (first inclined portion 222b). Even in this case, the light (intensity flare light) reaching the lens 21 and the image sensor 23 is further suppressed. In other words, since the amount of intensity flare light reaching the lens 21 and the image sensor 23 is further suppressed, a 3D distance measuring module 1b can be realized in which the occurrence of distance miscalculations is further suppressed. That is, when the object X is located in the direction of the optical axis A1, intensity flare light is not generated. However, as shown in Figure 22, when the angle between the direction connecting the object X and the image sensor 23 and the direction of the optical axis A1 is α, intensity flare light may be generated.

[0243] The inventors then conducted further studies and arrived at the following modification 3 of Embodiment 1.

[0244] (Modification 3 of Embodiment 1) Next, a modification 3 of Embodiment 1 will be described. In modification 3 of Embodiment 1, the degree of inclination of the first inclined portion 222c formed on the first surface 221c differs from that of modification 2 of Embodiment 1. In the following, the differences from modification 2 of Embodiment 1 will be explained in detail, and the explanation of the common points will be omitted or simplified.

[0245] [composition] Figure 23 is a cross-sectional view of the three-dimensional distance measuring module 1c according to this modified example.

[0246] The three-dimensional distance measuring module 1c according to this modified example has the same configuration as the three-dimensional distance measuring module 1b according to modified example 2 of Embodiment 1, except that it includes a lens module 20c instead of the lens module 20.

[0247] The lens module 20c has the same configuration as the lens module 20b, except that the lens barrel 22b is replaced with a lens barrel 22c.

[0248] The lens barrel 22c has the same configuration as the lens barrel 22b, except that the first surface 221b is replaced with a first surface 221c.

[0249] The first surface 221c includes a first inclined portion 222c that inclines away from the lens cover 30. That is, the first surface 221c includes a first inclined portion 222c that inclines downward as it moves away from the optical axis A1. More specifically, the first inclined portion 222c is formed over the entire first surface 221c. The inclination angle, which is the angle formed by the first inclined portion 222c and the plane perpendicular to the optical axis A1 (i.e., the xy plane), is β.

[0250] In this modification, β, which is the angle formed by the first inclined portion 222c and the plane perpendicular to the optical axis A1 (i.e., the xy plane), that is, the inclination angle, is ε / 2 or more.

[0251] Here, ε will be described.

[0252] First, consider the case of viewing the lens 21 from the object X side of the lens cover 30. That is, this case is when viewing the lens 21 from the upper surface side of the lens cover 30. As an example, the case of viewing the lens 21 from the positive x-axis side and the positive z-axis side (i.e., the direction in which the reflected light L is incident) shown in FIG. 23 will be described.

[0253] In this case, let ε be the maximum angle formed by the optical axis A1 and the direction in which the front side of the lens 21 can be visually recognized. More specifically, "the front side of the lens 21 can be visually recognized" means that the front side of the lens 21 can be visually recognized without being blocked by components other than the lens 21 included in the three-dimensional distance measurement module 1c. The front side of the lens 21 is, as described above, the point on the lens 21 that is the farthest in the positive x-axis direction when looking at the lens 21. Since the light-shielding member 51 is provided between the light source 10 and the lens module 20c, within the range not blocked by the light-shielding member 51, the maximum angle formed by the optical axis A1 and the direction in which the front side of the lens 21 can be visually recognized is ε. Similar to the second modification example of the first embodiment, in this modification example as well, the angle formed by the direction connecting the object X and the imaging element 23 and the optical axis A1 direction (z-axis direction) is α, and an example where α is ε is shown in FIG. 23.

[0254] Here, let C be the distance between the inner surface 223 of the lens barrel 22c and the light-shielding member 51. Further, let H0 be the distance between the second surface 42, which is the upper surface of the substrate 40 facing the lens cover 30, and the third surface 31 of the lens cover 30.

[0255] Here, regarding the influence on the flare light amount when the values of α and β change, we will examine it using FIGS. 24 to 28. Considering the point that the first surface 221c is a specular reflection surface with a scattering half-value width of 3 degrees, D is 5 mm, H0 is 2 mm, and C is infinite, the flare light amounts for FIGS. 24 to 28 were calculated in the same method as the method by which (a) in FIG. 6 was calculated. Note that the front reflectance R1 of the first surface 221c is set to 10%.

[0256] FIGS. 24 to 28 are diagrams showing the influence on the flare light amount when the tilt angle of the first inclined portion 222c according to this modification example is changed.

[0257] In Figure 28, the flare light quantity is calculated for the 3D distance measuring module according to the fifth embodiment, which corresponds to the 3D distance measuring module 1c according to this modified example, and in which β is 45 degrees. The 3D distance measuring modules shown in Figures 24 to 27, in which β is 0 degrees, 15 degrees, 30 degrees, and 44 degrees, respectively, are the 3D distance measuring modules according to the second, third, fourth, and fifth study examples, and do not correspond to the 3D distance measuring module 1c according to this modified example. The 3D distance measuring modules according to the second to fifth study examples have the same configuration as the 3D distance measuring module 1c according to this modified example, except for the value of β.

[0258] Figures 24 to 27 show that a peak in flare light intensity occurs in the 3D ranging modules related to the second to fifth study examples. In other words, high-intensity flare light is generated.

[0259] However, as shown in Figure 28, the 3D ranging module according to the fifth embodiment does not produce a peak in flare light intensity. In other words, the intensity of flare light is suppressed, or more specifically, no intensity of flare light is generated.

[0260] In other words, under the conditions where D is 5 mm, H0 is 2 mm, and C is infinite, ε is 90 degrees, and the intensity of the flare light is suppressed because β is greater than or equal to ε / 2. Also, β is a value that satisfies equation (4).

[0261]

number

[0262] [Effects, etc.] In the three-dimensional distance measuring module 1c according to this modified example, when viewing the lens 21 from the object side of the lens cover 30, ε is defined as the maximum angle between the optical axis A1 and the direction in which the front side of the lens 21 can be seen. At this time, the angle between the first inclined portion 222c and the plane perpendicular to the optical axis A1 is ε / 2 or greater.

[0263] When laser light reflected by an object X corresponding to a bright spot is specularly reflected by the first surface 221c (first inclined portion 222c), reflection within the 3D distance measuring module 1c may generate light (intensity flare light) that reaches the lens and image sensor. Because the angle between the first inclined portion 222c and the plane perpendicular to the optical axis A1 of the lens 21 is within the above-mentioned angular range, the laser light reflected by the object X is reflected by components of the 3D distance measuring module 1c (e.g., light-shielding member 51), making it difficult for it to reach the lens 21 and image sensor 23. In other words, the amount of intensity flare light reaching the lens 21 and image sensor 23 is further suppressed, making it possible to realize a 3D distance measuring module 1c that further suppresses the occurrence of distance miscalculations.

[0264] (Embodiment 2) Next, Embodiment 2 will be described. In the following, the differences from Embodiment 1 will be the main focus of the explanation, and the similarities will be omitted or simplified.

[0265] [composition] An example of the configuration of the 3D distance measuring module 1d according to Embodiment 2 will be explained with reference to Figure 29.

[0266] Figure 29 is a top view and a cross-sectional view of the 3D distance measuring module 1d according to this embodiment.

[0267] More specifically, Figure 29(a) is a top view of the 3D ranging module 1d, and Figure 29(b) is a cross-sectional view of the 3D ranging module 1d along the line XXIXb-XXIXb in Figure 29(a).

[0268] The 3D distance measuring module 1d according to this embodiment has the same configuration as the 3D distance measuring module 1 according to Embodiment 1, except that it includes a substrate 40d instead of a substrate 40.

[0269] Since the three-dimensional distance measurement module 1d includes the lens module 20 having the lens barrel 22, it can be said that the three-dimensional distance measurement module 1d includes the lens barrel 22. However, the three-dimensional distance measurement module 1d may not include the lens barrel 22. Further, in the present embodiment, the first surface 221 of the lens barrel 22 is a light diffusion reflecting surface that diffuses the laser light and includes the first inclined portion 222. However, the present invention is not limited to this, and the first surface 221 may not include the first inclined portion 222. For example, in the present embodiment, β may be 0 degrees.

[0270] When the substrate 40d views the lens 21 in the direction of the optical axis A1 of the lens 21 from the lens cover 30, that is, in the top view shown in FIG. 29(a), the substrate 40d is a member having an opening 41d so as to enclose the lens 21. The substrate 40d has a second surface 42d which is an upper surface facing the lens cover 30 and a lower surface facing the bottom surface portion 54 of the housing.

[0271] In the present embodiment, the shape of the opening 41d is circular in a top view, but is not limited thereto. The diameter of the opening 41d may be such that the opening 41d can enclose the lens 21, or the opening 41d can enclose the lens module 20.

[0272] The substrate 40d is a substrate member on which the light source 10 is provided. The light source 10 is provided in contact with the upper side of the substrate 40d. That is, the substrate 40d is a mounting substrate for mounting the light source 10. The substrate 40d has the same configuration as the substrate 40 except for the shape.

[0273] Further, the second surface 42d of the substrate 40d is a light diffusion reflecting surface that diffuses (scatters) the laser light. For example, the half-value width of the light scattering angle of the laser light on the second surface 42d may be 30 degrees or more and 60 degrees or less, more preferably 40 degrees or more and 60 degrees or less, and even more preferably 50 degrees or more and 60 degrees or less.

[0274] Here, the positional relationship of the components of the three-dimensional distance measurement module 1d according to the present embodiment will be described in more detail.

[0275] The cross-sectional view shown in Figure 29(b) can also be described as a cross-sectional view of the lens 21 when it is cut by a plane containing the optical axis A1 of the lens 21.

[0276] In this cross-sectional view, the following B, H1, H2, and θ5 are defined.

[0277] First, let B be the distance between the outer end of lens 21 and the outer end of aperture 41d. For example, as shown in Figure 29(b), the outer end of lens 21 is the end of lens 21 closest to the positive x-axis, and the outer end of aperture 41d is the edge of aperture 41d. Also, in a cross-sectional view, the outer end of lens 21 and the inner surface 223 of lens barrel 22 coincide on the x-axis. Furthermore, the distance between the outer end of lens 21 and the outer end of aperture 41d can also be said to be the distance between the closest points of lens 21 and substrate 40d to each other.

[0278] Furthermore, let H1 be the distance between the lens cover 30 and the center 211 of the lens 21. In other words, H1 is the length in the z-axis direction from the plane of the plano-convex lens 21 to the third surface 31.

[0279] Furthermore, let H2 be the distance between the lens cover 30 and the second surface 42d of the substrate 40d, which is an example of a component, that faces the lens cover 30. In other words, H2 is the length in the z-axis direction from the third surface 31 to the second surface 42d.

[0280] Next, let θ5 be the angle between the line connecting the center 211 of the lens 21 and the outer edge of the image sensor 23 and the optical axis A1 of the lens 21. Here, the outer edge of the image sensor 23 in the cross-sectional view is, for example, the point on the upper surface of the image sensor 23 that is furthest to the negative x-axis. In Figure 29(b), the line connecting the center 211 of the lens 21 and the outer edge of the image sensor 23 coincides with the direction of propagation of the light reflected by the second surface 42d and the third surface 31 of the reflected light L.

[0281] In this embodiment, B, H1, H2, and θ5 as defined above satisfy the following equation (5).

[0282] (H1+H2)×tanθ5≦B Equation (5)

[0283] Here, we will explain the behavior of reflected light L, which is the light reflected by object X from the laser beam emitted from light source 10.

[0284] Figure 29(b) shows three reflected light sources L.

[0285] One of the three reflected light rays L enters the lens 21 of the lens module 20 directly through the lens cover 30 and forms an image at a single point on the image sensor 23.

[0286] Furthermore, one of the three reflected light rays L does not directly enter the lens 21, but reaches the first surface 221 where it is diffusely reflected, is further reflected by the third surface 31, passes through the lens 21, and enters the image sensor 23.

[0287] Furthermore, one of the three reflected light rays L exhibits the following behavior.

[0288] This light does not directly enter the lens 21 but reaches the second surface 42d. The light that reaches the second surface 42d is diffusely reflected. Furthermore, the light diffusely reflected at a reflection angle of θ5 is reflected again by the third surface 31, passes through the lens 21, and enters the image sensor 23. The angle of incidence of the light reflected by the third surface 31 to the image sensor 23 is θ5.

[0289] Here, using the same method as that used to calculate Figure 6(a), we will examine the effect of changes in the values ​​of D, B, H1, and H2 on the amount of flare light, using Figures 30 to 33.

[0290] Figures 30 to 33 show the effects on the amount of flare light when D, B, H1, and H2 in this embodiment are changed, respectively. For calculation purposes, A, which is the thickness of the telescope tube 22, is set to 0 mm, meaning that the amount of flare light caused only by reflection from the second surface 42d is calculated.

[0291] Here, in FIGS. 30 to 32, D is 5 mm, and in FIG. 33, D is 10 mm. H1 and H2 are 1 mm in FIG. 30, 2 mm in FIGS. 31 and 33, and 4 mm in FIG. 32.

[0292] In FIGS. 30 to 33, if the flare light quantity value is below the detection lower limit at θ5 less than half-width angle, it means that no intensity flare light occurs in the imaging element 23.

[0293] In FIG. 30 (i.e., D is 5 mm, H1 and H2 are 1 mm), the flare light quantity is below the detection lower limit at 2 < B for a half-width angle of 45 degrees, 3.5 < B for a half-width angle of 60 degrees, and 5.5 < B for a half-width angle of 70 degrees.

[0294] In FIG. 31 (i.e., D is 5 mm, H1 and H2 are 2 mm), the flare light quantity is below the detection lower limit at 4 < B for a half-width angle of 45 degrees, 7 < B for a half-width angle of 60 degrees, and 11 < B for a half-width angle of 70 degrees.

[0295] In FIG. 32 (i.e., D is 5 mm, H1 and H2 are 4 mm), the flare light quantity is below the detection lower limit at 8 < B for a half-width angle of 45 degrees, 14 < B for a half-width angle of 60 degrees, and 22 < B for a half-width angle of 70 degrees.

[0296] A generalized formula for these corresponds to formula (5). That is, when formula (5) is satisfied, the flare light quantity becomes below the detection lower limit, and the generation of intensity flare light is suppressed.

[0297] Furthermore, compare FIGS. 31 and 33. From this comparison, it became clear that when only D has different values, the change in the flare light quantity is small.

[0298] Furthermore, for the manufacturing of the 3D ranging module 1d, A is required to be 1 mm or more. As shown in Figure 13(a), in the first example of the 3D ranging module where D is 5 mm, A is 1 mm, H1 and H2 are 2 mm, and β is 0 degrees, the peak value of the flare light amount due to the lens barrel was 10. Therefore, if the peak value of the flare light amount due to reflection from the second surface 42d is 10 or less, it can be said that the generation of high-intensity flare light is suppressed more effectively than in the first example of the 3D ranging module. For example, although the corresponding graphs for B are not shown in Figures 30-33, by setting B < 2.8 for a half-angle of view of 45 degrees, B < 5 for a half-angle of view of 60 degrees, or B < 8 for a half-angle of view of 70 degrees, the flare light originating from the second surface 42d becomes smaller than the flare light originating from the lens barrel 22, and the overall increase in the generation of high-intensity flare light is suppressed.

[0299] [Effects, etc.] The 3D distance measuring module 1d according to this embodiment includes a light source 10, a lens 21, an image sensor 23, a lens cover 30, and a component (substrate 40d).

[0300] Light source 10 emits laser light.

[0301] Lens 21 focuses the light reflected by the object from the emitted laser beam.

[0302] The image sensor 23 receives light that has been focused by the lens 21.

[0303] The lens cover 30 is positioned between the lens 21 and the object and is transparent to the wavelength of the laser light. The component (substrate 40d) has an aperture 41d that encloses the lens 21 when the lens 21 is viewed from the lens cover 30 in the direction of the optical axis A1 of the lens 21. In a cross-sectional view when the lens 21 is cut by a plane containing the optical axis A1, let B be the distance between the outer end of the lens 21 and the outer end of the aperture 41d, and let H1 be the distance between the lens cover 30 and the center of the lens 21. Furthermore, in the above cross-sectional view, let H2 be the distance between the lens cover 30 and the second surface 42d of the component (substrate 40d) that faces the lens cover 30, and let θ be the angle between the line connecting the center of the lens 21 and the outer end of the image sensor 23 and the optical axis A1, then the relationship (H1 + H2)·tanθ ≤ B is satisfied. The second surface 42d is, for example, a surface that diffusely reflects light.

[0304] As a result, when the laser light reflected by the object X corresponding to the bright spot is diffusely reflected by the second surface 42d, the light (intensity flare light) reaching the lens 21 and image sensor 23 is suppressed. For example, as described above, in a 3D distance measuring module where D is 5 mm, A is 1 mm, H1 and H2 are 2 mm, and β is 0 degrees, the peak value of the flare light amount due to the lens barrel is 10. However, in this embodiment, as shown in Figures 30 to 33, a 3D distance measuring module 1d can be realized in which the peak value of the flare light amount due to reflection at the second surface 42d is 10 or less. In other words, since the flare light caused by the second surface 42d can be made smaller than the flare light caused by the lens barrel 22, the overall increase in the generation of intensity flare light can be suppressed, and a 3D distance measuring module 1d in which the increase in the occurrence of distance miscalculations can be suppressed can be realized.

[0305] Furthermore, the 3D distance measuring module 1d includes a light source 10, a lens module 20 including a lens 21, an image sensor 23, and a lens barrel 22 that encloses the space between the lens 21 and the image sensor 23 and supports the lens 21, a lens cover 30, and a component (substrate 40d). In a cross-sectional view when the lens barrel 22 is cut by a plane containing the optical axis A1 of the lens 21, the first surface 221 of the lens barrel 22 facing the object includes a first inclined portion 222 that inclins away from the lens cover 30 as it moves away from the optical axis A1. Also, the relationship (H1+H2)·tanθ≦B is satisfied.

[0306] As a result, when the laser light reflected by the object X corresponding to the bright spot is reflected by the first surface 221 (first inclined portion 222), the light (intensity flare light) reaching the lens 21 and image sensor 23 is suppressed. Furthermore, when the laser light reflected by the object X corresponding to the bright spot is diffusely reflected by the second surface 42d, the light (intensity flare light) reaching the lens 21 and image sensor 23 is also suppressed. In other words, the amount of intensity flare light reaching the lens 21 and image sensor 23 as a whole is suppressed, making it possible to realize a 3D distance measuring module 1d in which the occurrence of distance miscalculations is suppressed.

[0307] (Modification 1 of Embodiment 2) Next, we will describe Modification 1 of Embodiment 2. In Modification 1 of Embodiment 2, the shape of the opening 41f differs from that of Embodiment 2. In the following, we will focus on explaining the differences from Embodiment 2, and omit or simplify the explanation of the common points.

[0308] [composition] A configuration example of the 3D distance measuring module 1f according to a modified example 1 of Embodiment 2 will be explained with reference to Figure 34.

[0309] Figure 34 shows a top view and two cross-sectional views of the 3D distance measuring module 1f according to this modified example.

[0310] More specifically, Figure 34(a) is a top view of the 3D distance measuring module 1f, and Figure 34(b) is a cross-sectional view of the 3D distance measuring module 1f along the line XXXIVb-XXXIVb in Figure 34(a). Figure 34(c) is a cross-sectional view of the 3D distance measuring module 1f along the line XXXIVc-XXXIVc in Figure 34(a).

[0311] The three-dimensional distance measuring module 1f according to this modified example has the same configuration as the three-dimensional distance measuring module 1d according to Embodiment 2, except that it includes a substrate 40f instead of a substrate 40d.

[0312] Substrate 40f has the same configuration as substrate 40d, except that it has an opening 41f instead of the opening 41d.

[0313] In this modified example, the shape of the aperture 41f is rectangular when viewed from above. When viewed from above, the aperture 41f should be large enough to enclose the lens 21 and the lens barrel 22, and also large enough to enclose the lens module 20.

[0314] In addition, as with Embodiment 2, in the 3D distance measuring module 1f according to this modified example, B, H1, H2, and θ5 satisfy the relationship in equation (5) above.

[0315] Furthermore, the 3D distance measuring module 1f may be equipped with a substrate 40ff instead of such a substrate 40f. The substrate 40ff will be explained with reference to Figure 35.

[0316] Figure 35 is a top view of the substrate 40ff according to this modified example.

[0317] More specifically, Figure 35(a) is a top view of substrate 40ff, and Figure 35(b) is a top view of opening 41ff. Substrate 40ff has the same configuration as substrate 40f, except that it has opening 41ff instead of opening 41f.

[0318] Furthermore, for the 3D distance measuring module 1f equipped with substrate 40ff, B, H1, H2, and θ5 also satisfy the relationship in equation (5) above.

[0319] In the top view, the lens 21 is circular in shape, and the image sensor 23 is rectangular (more specifically, rectangular in shape). In this case, regardless of the angle of rotation, if B, H1, H2, and θ5 satisfy the relationship in equation (6) below, then when viewed from the direction of the optical axis A1, that is, the shape of the aperture 41ff in the top view is barrel-shaped.

[0320] (H1+H2)×tanθ5=B Equation (6)

[0321] As described above, the shape of the aperture 41ff in the top view is barrel-shaped; in other words, the shape of the aperture 41ff is intermediate between the circular shape of the lens 21 and the rectangular shape of the image sensor 23. Furthermore, in Figure 35(b), a rectangle 231 similar in shape to the image sensor 23 is shown by a dashed line, indicating that the aperture 41ff is formed to be inscribed on the outer edge or vertex of the rectangle 231 that is in contact with the lens 21. With such a shape, the probability of flare light generation is the same regardless of the angle of rotation.

[0322] As shown in Figures 31 and 33, even if D is different, the dependence of the flare light on the value of B remains almost unchanged if other conditions are the same. For example, if B satisfies equation (6), that is, if the distance between the outer shape of the aperture 41ff and the lens 21 is sufficiently large, the generation of high-intensity flare light caused by reflection from the second surface 42d of the substrate 40ff can be suppressed.

[0323] Furthermore, the 3D distance measuring module 1x according to the sixth embodiment will be explained with reference to Figure 36.

[0324] Figure 36 is a cross-sectional view of the 3D distance measuring module 1x according to the sixth embodiment.

[0325] The 3D distance measuring module 1x according to the sixth embodiment has the same configuration as the 3D distance measuring module 1d according to the second embodiment, except that it includes a substrate 40x instead of a substrate 40d.

[0326] Substrate 40x has the same configuration as substrate 40d, except that it has an opening 41x instead of an opening 41d.

[0327] The shape of aperture 41x is larger than aperture 41d when viewed from above. In other words, in the sixth embodiment, B is larger than in embodiment 2. As a result, as shown in Figure 36, reflected light L is incident on the upper surface of the housing bottom portion 54 and reflected, further reflected by the lens cover 30, and reaches the image sensor of the lens module 20. However, most of this light is reflected by the outer surface of the lens barrel of the lens module 20. In other words, it is blocked by the outer surface of the lens barrel. As a result, the generation of high-intensity flare light is suppressed.

[0328] [Effects, etc.] In the three-dimensional distance measuring module 1f according to this modified example, the outer shape of the aperture 41ff is barrel-shaped when viewed from the direction of the optical axis A1.

[0329] As described above, when the lens 21 is cut by a plane containing the optical axis A1, and the distance between the outer end of the lens 21 and the outer end of the aperture 41ff is B, then B satisfies equation (6) regardless of the angle of rotation. In other words, the distance between the outer shape of the aperture 41ff and the lens 21 can be uniformly and sufficiently large, so the generation of high-intensity flare light caused by reflection from the second surface 42d of the substrate 40ff can be suppressed most efficiently. Therefore, since the amount of high-intensity flare light reaching the lens 21 and the image sensor 23 is further suppressed, a 3D distance measuring module 1f can be realized in which the occurrence of distance miscalculations is further suppressed.

[0330] (Modification 2 of Embodiment 2) Next, a modified example of Embodiment 2 will be described. Modified example 2 of Embodiment 2 differs from Embodiment 2 in that the second surface 42g of the substrate 40g includes a second inclined portion 422g. In the following, the differences from Embodiment 2 will be explained in detail, and the explanation of the common points will be omitted or simplified.

[0331] [composition] Figure 37 shows a top view and a cross-sectional view of the three-dimensional distance measuring module 1g according to this modified example.

[0332] More specifically, Figure 37(a) is a top view of the 3D ranging module 1g, and Figure 37(b) is a cross-sectional view of the 3D ranging module 1g along the line XXXVIIb-XXXVIIb in Figure 37(a).

[0333] The three-dimensional distance measuring module 1g according to this modified example has the same configuration as the three-dimensional distance measuring module 1d according to Embodiment 2, except that it includes a substrate 40g instead of a substrate 40d.

[0334] The substrate 40g has a second surface 42g which is the upper surface facing the lens cover 30.

[0335] In a cross-sectional view when the lens 21 is cut along a plane containing the optical axis A1, that is, in the cross-sectional view shown in Figure 37(b), the second surface 42g includes a second inclined portion 422g that slopes away from the lens cover 30 as it moves away from the optical axis A1. In other words, the second surface 42g includes a second inclined portion 422g that slopes downward as it moves away from the optical axis A1. More specifically, the second inclined portion 422g is formed over the entire second surface 42g around the aperture 41g. In the cross-sectional view shown in Figure 37(b), when the lens 21 is cut along a plane containing the optical axis A1, the second inclined portion 422g is linear. In this modified example, the second inclined portion 422g is linear in the cross-sectional view obtained when the lens 21 is cut along any plane containing the optical axis A1.

[0336] As shown in Figure 37(b), the inclination angle, which is the angle between the second inclined portion 422g and the plane perpendicular to the optical axis A1 (i.e., the xy-plane), is η. In this modified example, a larger η is better, but if it is too large, it will not be considered an upper surface but will take on the properties of a side surface, so an angle of about 60 degrees or less is a realistic upper surface. That is, η is good if it is between 1 degree and 60 degrees, and even better if it is between 15 degrees and 60 degrees, and tan -1It is even better if the angle is greater than or equal to ((H1+H2) / (D+A)) and less than or equal to 60 degrees. Furthermore, no matter which plane the lens 21 is cut on as long as it contains the optical axis A1 of the lens 21, the second inclined portion 422g is linear in the resulting cross-sectional view, and η is constant in any cross-sectional view.

[0337] Furthermore, for the 3D distance measuring module 1g related to this modified example, B, H1, H2, and θ5 also satisfy the relationship in equation (5) above. Here, H2 is defined as the distance between the lens cover 30 and the uppermost end of the second surface 42g (second inclined portion 422g).

[0338] [Effects, etc.] In the modified 3D distance measuring module 1g, the second surface 42g in the cross-sectional view described above includes a second inclined portion 422g that tilts away from the lens cover 30 as it moves away from the optical axis A1.

[0339] As a result, when the laser light reflected by the object X corresponding to the bright spot is reflected by the second surface 42g (second inclined portion 422g), the laser light is more likely to be reflected from the second surface 42g (second inclined portion 422g) in the direction opposite to the lens 21 and image sensor 23. In other words, the amount of intensity flare light reaching the lens 21 and image sensor 23 is further suppressed, making it possible to realize a 3D distance measuring module 1g in which the occurrence of distance miscalculations is further suppressed. In particular, when the inclination angle is tan -1 If the value is greater than or equal to ((H1+H2) / (D+A)), the flare caused by the above can be eliminated, so the effect is significant.

[0340] (Embodiment 3) Next, Embodiment 3 will be described. Embodiment 3 differs from Embodiment 1 mainly in that the third surface 31h of the lens cover 30h includes a third inclined portion 311h. In the following, the differences from Embodiment 1 will be explained in detail, and the explanation of the common points will be omitted or simplified.

[0341] [composition] An example of the configuration of the 3D distance measuring module 1h according to Embodiment 3 will be explained with reference to Figure 38.

[0342] Figure 38 is a cross-sectional view of the 3D distance measuring module 1h according to this embodiment.

[0343] The 3D distance measuring module 1h according to this embodiment has the same configuration as the 3D distance measuring module 1 according to Embodiment 1, except that it includes a lens module 20h instead of a lens module 20, and a lens cover 30h instead of a lens cover 30. The 3D distance measuring module 1h according to this embodiment includes a substrate 40, but is not limited to this, and may not include a substrate 40.

[0344] The lens module 20h has the same configuration as the lens module 20, except that it has a lens barrel 22h instead of a lens barrel 22.

[0345] The telescope tube 22h has the same configuration as the telescope tube 22, except for its shape.

[0346] The lens barrel 22h has a bottomless cylindrical shape and is cylindrical in shape. A cylindrical cavity is formed inside the lens barrel 22h. The lens barrel 22h extends along the optical axis A1 of the lens 21, and the optical axis A1 of the lens 21 and the axis of the lens barrel 22h coincide. As described above, since the lens barrel 22h is cylindrical, the outer shape of the cross section cut by a plane perpendicular to the optical axis A1 is annular.

[0347] Here, the surface (top surface) of the lens barrel 22h facing the object X is defined as the first surface 221h. Unlike Embodiment 1, the first surface 221h is parallel to the xy plane and does not include an inclined portion. Furthermore, the first surface 221h is a light-diffusing reflective surface that diffuses (scatters) the laser light.

[0348] Lens cover 30h has the same configuration as lens cover 30, except for its shape.

[0349] Furthermore, the lens cover 30h has a third surface 31h which is the lower surface facing the lens module 20h and a fourth surface 32h which is the upper surface facing the object X.

[0350] The third surface 31h includes a third inclined portion 311h that inclins away from the lens module 20h as it moves away from the optical axis A1 of the lens 21. In other words, the third surface 31h includes a third inclined portion 311h that inclins upward as it moves away from the optical axis A1. In this embodiment, the third inclined portion 311h is formed over the entire third surface 31h above the lens module 20h, more specifically above the aperture 41. More specifically, when viewed from the direction of the optical axis A1, for example in the top view, the third inclined portion 311h is formed over the entire region where the third inclined portion 311h and the lens module 20h overlap. In the cross-sectional view shown in Figure 38, when the lens cover 30h is cut along the plane containing the optical axis A1 of the lens 21, the third inclined portion 311h is linear. In this embodiment, regardless of which plane the lens cover 30h is cut on, as long as it includes the optical axis A1 of the lens 21, the third inclined portion 311h will be linear in the resulting cross-sectional view.

[0351] As shown in Figure 38, the inclination angle, which is the angle between the third inclined portion 311h and the plane perpendicular to the optical axis A1 (i.e., the xy-plane), is ζ. In this embodiment, ζ is preferably between 5 degrees and 45 degrees, more preferably between 10 degrees and 45 degrees, and even better between 20 degrees and 45 degrees. Furthermore, no matter which plane containing the optical axis A1 of the lens 21 the lens cover 30h is cut, the third inclined portion 311h is linear in the resulting cross-sectional view, and ζ remains constant in any cross-sectional view.

[0352] Furthermore, on the third surface 31h, the point where the optical axis A1 of the third inclined portion 311h coincides is the point located furthest below the z-axis, and is the lowest end of the third surface 31h. Here, the distance from this lowest end to the center 211 of the lens 21 is denoted as H3. Moreover, the distance in the z-axis direction between the plane passing through this lowest end and perpendicular to the optical axis A1 (i.e., the plane parallel to the xy-plane) and the third inclined portion 311h is denoted as ΔH.

[0353] Furthermore, the fourth surface 32h of the lens cover 30h includes a fourth inclined portion 321h that is inclined upward as it moves away from the optical axis A1 in the region where the third inclined portion 311h is provided. The fourth inclined portion 321h is linear, just like the third inclined portion 311h. The degree of inclination of the third inclined portion 311h and the fourth inclined portion 321h, that is, the inclination angle which is the angle made between each of the third inclined portion 311h and the fourth inclined portion 321h and the plane perpendicular to the optical axis A1 (i.e., the xy plane), is the same.

[0354] Next, the behavior of light according to this embodiment will be described.

[0355] The reflected light L1 is the light reflected by the object Y from the laser beam emitted from the light source 10. The angle between this reflected light L1 and the optical axis A1 is θ6, which means that the angle of incidence of the reflected light L1 to the image sensor 23 is θ6. This reflected light L1 forms an image at a single point on the image sensor 23.

[0356] Furthermore, the reflected light L shown in Figure 38 does not directly enter the lens 21, but passes through the fourth inclined portion 321h and the third inclined portion 311h of the lens cover 30h and reaches the first surface 221h. Refraction occurs when the reflected light L passes through the third inclined portion 311h and the fourth inclined portion 321h.

[0357] Furthermore, some of the light that reaches the first surface 221h is reflected at a reflection angle of θ6+2ζ. The reflected light then reaches the third surface 31h (more specifically, the third inclined portion 311h), is reflected again, passes through the lens 21, and enters the image sensor 23. The point at which some of this light enters the image sensor 23 is the same point at which the reflected light L1 entered the image sensor 23 (the point mentioned above). In other words, at this point, an intense flare is generated.

[0358] Furthermore, the amount of this flare light intensity (hereinafter referred to as flare light intensity) is calculated using the following method.

[0359] Similar to Embodiment 1, the object X (bright spot) is located in the direction of the optical axis A1 (z-axis direction). As described above, the inclination angle of the third inclined portion 311h is ζ. The frontal reflectance of the first surface 221h is R1, and the frontal reflectance of the third surface 31h is R2.

[0360] Here, the amount of reflected light L1, which is light reflected by the object Y, is expressed by equation (7).

[0361]

number

[0362] In equation (7), losses in the lens cover 30 and lens 21 are ignored. Furthermore, the amount of flare light is expressed by equation (8).

[0363]

number

[0364] Furthermore, when θ6 is small, the light reflected by the third surface 31h may be reflected again by the first surface 221h (more specifically, the first surface 221h on the positive x-axis side as shown in Figure 38) and may not reach the lens 21. This is what is known as the light being obscured by the first surface 221h of the lens barrel 22h. The amount of flare light corresponding to the case where θ6 in equation (8) is smaller than θ7 that satisfies equation (9) is subtracted from the amount of flare light calculated in equation (8).

[0365] (H3-ΔH)tanθ7+(H3-ΔH)tan(θ7+2ζ)=A Equation (9)

[0366] Furthermore, when θ6 is large, the light reflected by the third surface 31h may be reflected again by the first surface 221h (more specifically, the first surface 221h on the negative x-axis side as shown in Figure 38) and may not reach the lens 21. This is also a state in which the light is obscured by the first surface 221h of the lens barrel 22h. The amount of flare light corresponding to the case where θ6 in equation (8) is greater than θ8 that satisfies equation (10) is subtracted from the amount of flare light calculated in equation (8).

[0367] (H3-ΔH)tanθ8+(H3-ΔH)tan(θ8+2ζ)=2D+A Equation (10)

[0368] As described above, the flare intensity is calculated. Next, we will examine the effect on the flare intensity when the tilt angle ζ of the third inclined section 311h is changed.

[0369] Figures 39 and 40 show the effect on the amount of flare light when the inclination angle of the third inclined section 311h according to this embodiment is changed.

[0370] In Figure 39, the flare light intensity is calculated for a 3D distance measuring module without the substrate 40, while in Figure 40, the flare light intensity is calculated for a 3D distance measuring module with the substrate 40. In Figures 39 and 40, D is 5 mm, H3 is 2 mm, and A is 2 mm, while in Figure 40, B is 3 mm.

[0371] In Figure 39, the flare light intensity is calculated for the 3D distance measuring modules according to the 7th, 8th, 9th, and 10th embodiments, which correspond to the 3D distance measuring module 1h without a substrate 40, and whose ζ is 5, 10, 15, and 20 degrees, respectively. Also, the 3D distance measuring module with ζ of 0 degrees shown in Figure 39 is the 3D distance measuring module according to the 6th study example and does not correspond to the 3D distance measuring module 1h according to this embodiment. The 3D distance measuring module according to the 6th study example has the same configuration as the 3D distance measuring module 1h without a substrate 40, except that ζ is 0 degrees, that is, the third surface 31h is parallel to the xy plane.

[0372] In Figure 40, the flare light intensity is calculated for the 3D distance measuring modules according to the 11th, 12th, 13th, and 14th embodiments, where ζ is 5, 10, 15, and 20 degrees, respectively, and which correspond to the 3D distance measuring module 1h equipped with the substrate 40 (i.e., the 3D distance measuring module 1h shown in Figure 38). Furthermore, the 3D distance measuring module with ζ of 0 degrees shown in Figure 40 is the 3D distance measuring module according to the 7th study example and does not correspond to the 3D distance measuring module 1h according to this embodiment. The 3D distance measuring module according to the 7th study example has the same configuration as the 3D distance measuring module 1h equipped with the substrate 40, except that ζ is 0 degrees, that is, the third surface 31h is parallel to the xy plane.

[0373] Figures 39 and 40 show the amount of flare light when the incident angle θ6 is changed.

[0374] We compare the 3D distance measuring modules according to the 6th and 7th study examples, in which the third surface 31h does not include the third inclined portion 311h (i.e., ζ is 0 degrees), with the 3D distance measuring modules according to the 7th to 14th embodiments, in which the third surface 31h includes the third inclined portion 311h (i.e., ζ is 5 degrees or more). Compared to the 3D distance measuring modules according to the 6th and 7th study examples, the 3D distance measuring modules according to the 7th to 14th embodiments, in which the third surface 31h includes the third inclined portion 311h, show a reduction in flare light intensity.

[0375] Furthermore, it is clear that in both Figure 39 and Figure 40, the amount of flare light is suppressed as ζ increases. Also, comparing Figure 39 and Figure 40, it is shown that when the 3D ranging module 1h does not have the substrate 40, the amount of flare light can be effectively suppressed in the range of θ6 from 30 to 70 degrees.

[0376] [Effects, etc.] The three-dimensional distance measuring module 1h according to this embodiment includes a light source 10, a lens module 20h, and a lens cover 30h.

[0377] Light source 10 emits laser light.

[0378] The lens module 20h includes a lens 21 that focuses the light reflected by the object from the irradiated laser beam, an image sensor 23 that receives the light focused by the lens 21, and a lens barrel 22h that encloses the space between the lens 21 and the image sensor 23 and supports the lens 21.

[0379] The lens cover 30h is positioned between the lens module 20h and the object and is transparent to the wavelength of the laser light. The third surface 31h of the lens cover 30h facing the lens module 20h includes a third inclined portion 311h that is inclined away from the lens module 20h as it moves away from the optical axis A1 of the lens 21.

[0380] As a result, when laser light reflected by an object X corresponding to a bright spot is reflected by the third surface 31h (third inclined portion 311h), the amount of light (intensity flare light) reaching the lens 21 and image sensor 23 is suppressed. For example, as explained in Figures 39 and 40, the amount of flare light is reduced in the 3D distance measuring modules according to the 7th to 14th embodiments, in which the third surface 31h includes the third inclined portion 311h, compared to the 3D distance measuring modules according to the 6th and 7th study examples. In other words, since the amount of intensity flare light reaching the lens 21 and image sensor 23 is suppressed, a 3D distance measuring module 1h can be realized in which the occurrence of distance miscalculations is suppressed. However, 3D distance measuring modules with a tilt angle ζ that is too large are undesirable because the captured image is greatly distorted near the center, and in practical terms, it was acceptable when ζ was 45 degrees or less.

[0381] In the three-dimensional distance measuring module 1h according to this embodiment, when viewed from the direction of the optical axis A1, the third inclined portion 311h is formed over the entire region in which the third inclined portion 311h and the lens module 20h overlap.

[0382] As a result, when laser light reflected by an object X corresponding to a bright spot is reflected by the third surface 31h (third inclined portion 311h), the laser light is more likely to be reflected from the third surface 31h (third inclined portion 311h) in the direction opposite to the lens 21 and image sensor 23. In other words, the amount of intensity flare light reaching the lens 21 and image sensor 23 is further suppressed, making it possible to realize a 3D distance measuring module 1h in which the occurrence of distance miscalculations is further suppressed.

[0383] (Modification 1 of Embodiment 3) Next, a modification 1 of Embodiment 3 will be described. Modification 1 of Embodiment 3 differs from Embodiment 3 in that the fourth surface 32j does not include the fourth inclined portion. In the following, the differences from Embodiment 3 will be explained in detail, and the explanation of the common points will be omitted or simplified.

[0384] [composition] An example of the configuration of the 3D distance measuring module 1j according to a modified example 1 of Embodiment 3 will be explained with reference to Figures 41 and 42.

[0385] Figure 41 shows a top view and two cross-sectional views of the 3D distance measuring module 1j according to this modified example.

[0386] More specifically, Figure 41(a) is a top view of the 3D ranging module 1j, and Figure 41(b) is a cross-sectional view of the 3D ranging module 1j along the XLIb-XLIb line in Figure 41(a). Figure 41(c) is a cross-sectional view of the 3D ranging module 1j along the XLIc-XLIc line in Figure 41(a).

[0387] Figure 42 is a cross-sectional view showing the behavior of light in the three-dimensional distance measuring module 1j according to this modified example.

[0388] The three-dimensional distance measuring module 1j according to this modified example has the same configuration as the three-dimensional distance measuring module 1h according to Embodiment 3, except that it is equipped with a lens cover 30j instead of a lens cover 30h. The three-dimensional distance measuring module 1j according to this modified example includes a substrate 40, but is not limited to this; it may be equipped without a substrate 40.

[0389] The lens cover 30j has a third surface 31j which is the lower surface facing the lens module 20h and a fourth surface 32j which is the upper surface facing the object X.

[0390] Furthermore, the third surface 31j has the same configuration as the third surface 31h according to Embodiment 3, and the third inclined portion 311j included in the third surface 31j also has the same configuration as the third inclined portion 311h according to Embodiment 3.

[0391] The fourth face 32j is flat, that is, a plane, and does not have a fourth inclined portion. The fourth face 32j is a plane parallel to the xy-plane.

[0392] Next, we will explain the behavior of light in this modified example.

[0393] The reflected light L1 behaves the same as in Embodiment 3, and this reflected light L1 is imaged at a single point on the image sensor 23.

[0394] Furthermore, the reflected light L shown in Figure 42 does not directly enter the lens 21, but enters and passes through the third inclined portion 311j in the lens cover 30j. At this time, the angle of incidence to the third inclined portion 311j is ζ, and the angle of exit from the third inclined portion 311j is γ. The light that has passed through the third inclined portion 311j reaches the first surface 221h.

[0395] Furthermore, some of the light that reaches the first surface 221h is reflected at a reflection angle of θ6+2ζ. The reflected light then reaches the third surface 31j (more specifically, the third inclined portion 311j), is reflected again, passes through the lens 21, and enters the image sensor 23. The point at which some of this light enters the image sensor 23 is the same point at which the reflected light L1 entered the image sensor 23 (the point mentioned above). In other words, at this point, an intense flare is generated.

[0396] Furthermore, the amount of this flare light intensity (hereinafter referred to as flare light intensity) is calculated using the following method.

[0397] Similar to Embodiment 3, the object X (bright spot) is located in the direction of the optical axis A1 (z-axis direction). As described above, the inclination angle of the third inclined portion 311j is ζ. The frontal reflectance of the first surface 221h is R1, and the frontal reflectance of the third surface 31j is R2.

[0398] Here, the amount of reflected light L1, which is light reflected by the object Y, is expressed by equation (7) above.

[0399] Furthermore, since the light scattering at the upper surface (first surface 221h) of the telescope tube 22 is uniform diffuse reflection, it does not depend on the angle γ of incidence to the uniform diffuse reflection surface, but only on the angle between the vertical line of the upper surface (first surface 221h) of the telescope tube 22 and the scattering direction. As a result, the amount of flare light is expressed by equation (11).

[0400]

number

[0401] Here, if the lens cover 30j is made of glass with a refractive index of 1.5 as an example, then ζ and γ satisfy equation (12).

[0402] sinγ=sinζ×(n1 / n2) Equation (12)

[0403] Note that n1 is the refractive index of the lens cover 30 (e.g., 1.5), and n2 is the refractive index of air (1.0). Furthermore, when ζ is 10 degrees, the emission angle γ is calculated by equation (13) and is approximately 15 degrees.

[0404] Asin(sin(10)×1.0 / 1.5) Equation (13)

[0405] Furthermore, when θ6 is small, the light reflected by the third surface 31j may be reflected again by the first surface 221h (more specifically, the first surface 221h on the positive x-axis side as shown in Figure 42) and may not reach the lens 21. This is what is known as the light being obscured by the first surface 221h of the lens barrel 22h. The amount of flare light corresponding to the case where θ6 in equation (11) is smaller than θ9 that satisfies equation (14) is subtracted from the amount of flare light calculated in equation (11).

[0406] (H3-ΔH)tanθ9+(H3-ΔH)tan(θ9+2ζ)≒A Equation (14)

[0407] Furthermore, when θ6 is large, the light reflected by the third surface 31j may be reflected again by the first surface 221h (more specifically, the first surface 221h on the negative x-axis side as shown in Figure 42) and may not reach the lens 21. This is also a state in which the light is obscured by the first surface 221h of the lens barrel 22h. The amount of flare light corresponding to the case where θ6 in equation (11) is greater than θ10 that satisfies equation (15) is subtracted from the amount of flare light calculated in equation (11).

[0408] (H3-ΔH)tanθ10+(H3-ΔH)tan(θ10+2ζ)≒2D+A Equation (15)

[0409] As described above, the flare intensity is calculated. Next, we will examine the effect on the flare intensity when the tilt angle ζ of the third inclined section 311j is changed.

[0410] Figures 43 and 44 show the effect on the amount of flare light when the inclination angle of the third inclined section 311j in this modified example is changed.

[0411] In Figure 43, the flare light intensity is calculated for a 3D distance measuring module without the substrate 40, and in Figure 44, it is calculated for a 3D distance measuring module with the substrate 40. In Figures 43 and 44, D is 5 mm, H3 is 2 mm, and A is 2 mm, while in Figure 44, B is 3 mm.

[0412] In Figure 43, the flare light intensity is calculated for the 3D distance measuring modules according to the 15th, 16th, 17th, and 18th embodiments, which correspond to the 3D distance measuring module 1j without a substrate 40, and whose ζ is 5, 10, 15, and 20 degrees, respectively. Furthermore, the 3D distance measuring module with ζ of 0 degrees shown in Figure 43 is the 3D distance measuring module according to the 8th study example and does not correspond to the 3D distance measuring module 1j according to this modified example. The 3D distance measuring module according to the 8th study example has the same configuration as the 3D distance measuring module 1j without a substrate 40, except that ζ is 0 degrees, that is, the third surface 31j is parallel to the xy plane.

[0413] In Figure 44, the flare light intensity is calculated for the 3D ranging modules according to the 19th, 20th, 21st, and 22nd embodiments, where ζ is 5, 10, 15, and 20 degrees, respectively, corresponding to the 3D ranging module 1j equipped with a substrate 40 (i.e., the 3D ranging module 1j shown in Figure 42). Furthermore, the 3D ranging module with ζ of 0 degrees shown in Figure 44 is the 3D ranging module according to the 9th study example and does not correspond to the 3D ranging module 1j according to this modified example. The 3D ranging module according to the 9th study example has the same configuration as the 3D ranging module 1j equipped with a substrate 40, except that ζ is 0 degrees, that is, the third surface 31j is parallel to the xy plane.

[0414] Figures 43 and 44 show the amount of flare light when the incident angle θ6 is changed. In both Figures 43 and 44, it is clear that the amount of flare light is suppressed as ζ increases. Furthermore, comparing Figures 43 and 44, it is shown that when the 3D distance measuring module 1j does not have the substrate 40, the amount of flare light can be effectively suppressed in the range of θ6 from 30 to 70 degrees.

[0415] [Effects, etc.] In the modified 3D distance measuring module 1j, the fourth surface 32j of the lens cover 30 facing the object is flat.

[0416] In an environment where the 3D distance measuring module 1j is used, if a person, who is an example of a distance measurement target, looks at the 3D distance measuring module 1j, and there are irregularities on the fourth surface 32j of the lens cover 30j, the person may feel uncomfortable. Therefore, if the fourth surface 32j is flat, this discomfort is eliminated, and the same effect as in Embodiment 3 is obtained. However, a 3D distance measuring module with a tilt ζ of too large an angle is undesirable because the captured image is not only greatly distorted near the center, but also has the effect of being magnified compared to Embodiment 3. In practical terms, an acceptable level was when ζ was 40 degrees or less.

[0417] (Modification 2 of Embodiment 3) Next, a modified example 2 of Embodiment 3 will be described. In modified example 2 of Embodiment 3, the fourth surface 32k does not include the fourth inclined portion, and the shape of the third inclined portion 311k in the top view differs from Embodiment 3. In the following, the differences from Embodiment 3 will be explained in detail, and the explanation of the common points will be omitted or simplified.

[0418] [composition] A configuration example of the 3D distance measuring module 1k according to a modified example 2 of Embodiment 3 will be explained with reference to Figure 45.

[0419] Figure 45 shows a top view and a cross-sectional view of the 3D distance measuring module 1k according to this modified example.

[0420] More specifically, Figure 45(a) is a top view of the 3D distance measuring module 1k, and Figure 45(b) is a cross-sectional view of the 3D distance measuring module 1k along the XLVb-XLVb line in Figure 45(a). Figure 45(c) is a cross-sectional view of the 3D distance measuring module 1k along the XLVc-XLVc line in Figure 45(a), and Figure 45(d) is a cross-sectional view of the 3D distance measuring module 1k along the XLVd-XLVd line in Figure 45(a).

[0421] The three-dimensional distance measuring module 1k according to this modified example has the same configuration as the three-dimensional distance measuring module 1h according to Embodiment 3, except that it is equipped with a lens cover 30k instead of the lens cover 30h.

[0422] Furthermore, the lens cover 30k has a third surface 31k which is the lower surface facing the lens module 20h and a fourth surface 32k which is the upper surface facing the object X.

[0423] Note that the fourth surface 32k has the same configuration as the fourth surface 32j in the modified example 1 of Embodiment 3.

[0424] The third surface 31k includes a third inclined portion 311k that slopes away from the lens module 20h as it moves away from the optical axis A1 of the lens 21. In other words, the third surface 31k includes a third inclined portion 311k that slopes upward as it moves away from the optical axis A1. When viewed from the direction of the optical axis A1, for example in the top view, the third inclined portion 311k is formed over the entire region where the third inclined portion 311k and the lens module 20h overlap. In the cross-sectional view shown in Figure 45, when the lens cover 30k is cut along a plane containing the optical axis A1 of the lens 21, the third inclined portion 311k is linear. In this modified example, the third inclined portion 311k is linear in the cross-sectional view obtained when the lens cover 30k is cut along any plane containing the optical axis A1 of the lens 21.

[0425] As shown in Figures 45(b) and (c), the inclination angle, which is the angle between the third inclined portion 311k and the plane perpendicular to the optical axis A1 (i.e., the xy-plane), is ζ. In this modified example, ζ is preferably between 5 degrees and 40 degrees, more preferably between 10 degrees and 40 degrees, and even better between 20 degrees and 40 degrees.

[0426] When viewed from the direction of the optical axis A1, that is, in the top view, the shape of the third inclined portion 311k is similar in shape to the shape of the image sensor 23. As described above, when viewed from the direction of the optical axis A1, the shape of the image sensor 23 is rectangular. Also, in Figure 45(a), the shape of the third inclined portion 311k, which is similar in shape to the shape of the image sensor 23 (rectangular), is shown by a rectangular dashed line.

[0427] The degree of inclination of the third inclined section 311k from a plane perpendicular to the optical axis A1 (i.e., the xy-plane) is represented by the inclination angle ζ of the third inclined section 311k. This degree of inclination (i.e., ζ) has a positive correlation with the distance between the optical axis A1 and the outer end of the third inclined section 311k. The outer end of the third inclined section 311k coincides with the outline of the third inclined section 311k (dashed rectangle) shown in Figure 45(a). In other words, in the top view, ζ of the third inclined section 311k in the direction connecting the optical axis A1 and one point on the outer end of the third inclined section 311k has a positive correlation with the distance between the optical axis A1 and the outer end of the third inclined section 311k. Furthermore, it is desirable that the tangent of ζ of the third inclined portion 311k in the direction connecting the optical axis A1 and a point at the outer end of the third inclined portion 311k be proportional to the distance between the optical axis A1 and the outer end of the third inclined portion 311k.

[0428] Here, the positive y-axis direction is defined as the reference direction. Let δ be the angle between this reference direction and the XLVb-XLVb line and the XLVc-XLVc line, respectively.

[0429] For example, in Figure 45(b), δ is 0, A, which is the thickness of the 22h telescope tube, is 1 mm, ζ is 10 degrees, and the half-angle of view is 14 degrees.

[0430] For example, in Figure 45(c), δ is greater than 0 degrees and ζ is 20 degrees, so the half-angle is greater than 14 degrees and reaches its maximum value. Also, in the cross-sectional view shown in Figure 45(d), the third surface 31k is curved convexly in the negative z-axis direction.

[0431] Figure 46 shows the relationship between δ and ζ in this modified example. As δ changes, the distance between the optical axis A1 and the outer end of the third inclined portion 311k changes. Consequently, the value of ζ also changes. For example, in the case of Figure 45(c), where the half-angle of view is larger than in Figure 45(b), the intensity of the flare light due to reflection from the second surface 42 of the substrate 40 becomes larger. In such a shape, the probability of flare light generation is the same regardless of the angle of rotation. Therefore, in Figure 45(c), where the half-angle of view is larger, increasing ζ makes it possible to reduce the amount of flare light uniformly in the direction of angle δ.

[0432] [Effects, etc.] In the three-dimensional distance measuring module 1k according to this modified example, the external shape of the third inclined portion 311k is similar to the external shape of the image sensor 23 when viewed from the direction of the optical axis A1. The degree of inclination of the third inclined portion 311k from a plane perpendicular to the optical axis A1 has a positive correlation with the distance between the optical axis A1 and the outer end of the third inclined portion 311k.

[0433] As described above, when the half-angle of view is larger (for example, Figure 45(c)), increasing ζ makes it possible to reduce the amount of flare light intensity uniformly in the angular δ direction. Therefore, since the amount of flare light intensity reaching the lens 21 and the image sensor 23 is suppressed more uniformly, a 3D distance measuring module 1k can be realized that further suppresses the occurrence of distance miscalculations. However, a 3D distance measuring module with a tilt ζ of too large an angle is undesirable because, in addition to the captured image being greatly distorted near the center, the image also has the added effect of the magnification amount differing depending on the direction compared to Embodiment 3, and in practical terms, it was only acceptable when ζ was 40 degrees or less.

[0434] (Modification 3 of Embodiment 3) Next, a modification 3 of Embodiment 3 will be described. Modification 3 of Embodiment 3 differs from Modification 1 of Embodiment 3 in that the lens cover 30m has an outer lens cover 33m and an inner lens cover 34m. In the following, the differences from Modification 1 of Embodiment 3 will be explained in detail, and the explanation of the common points will be omitted or simplified.

[0435] [composition] A configuration example of a 1m three-dimensional distance measuring module according to a modified example 3 of Embodiment 3 will be explained with reference to Figure 47.

[0436] Figure 47 shows a top view and two cross-sectional views of a 1m three-dimensional distance measuring module relating to this modified example.

[0437] More specifically, Figure 47(a) is a top view of the 3D ranging module 1m, and Figure 47(b) is a cross-sectional view of the 3D ranging module 1m along the XLVIIb-XLVIIb line in Figure 47(a). Figure 47(c) is a cross-sectional view of the 3D ranging module 1m along the XLVIIc-XLVIIc line in Figure 47(a).

[0438] The three-dimensional distance measuring module 1m according to this modified example has the same configuration as the three-dimensional distance measuring module 1j according to Modified Example 1 of Embodiment 3, except that it is equipped with a lens cover 30m instead of a lens cover 30j.

[0439] The lens cover 30m has a third surface 31m which is the lower surface facing the lens module 20h and a fourth surface 32m which is the upper surface facing the object X.

[0440] Furthermore, the lens cover 30m has an outer lens cover 33m and an inner lens cover 34m. In other words, the lens cover 30m is composed of two components: an outer lens cover 33m and an inner lens cover 34m.

[0441] The upper surface of the outer lens cover 33m corresponds to the fourth surface 32m. The outer lens cover 33m is a plate-shaped member located between the lens module 20h and the object X. It can also be said that the outer lens cover 33m is the same member as the lens cover 30 according to Embodiment 1.

[0442] The inner lens cover 34m is a thin plate-like component provided between the outer lens cover 33m and the lens module 20h. The inner lens cover 34m is provided connected to the lower surface of the outer lens cover 33m. The third surface 31m, which is the lower surface of the lens cover 30m, is a surface formed by combining a part of the lower surface of the outer lens cover 33m and the lower surface of the inner lens cover 34m.

[0443] The inner lens cover 34m is a curved member that is convex toward the lens module 20h (i.e., in the negative z-axis direction). For this reason, the third inclined portion 311m of the third surface 31m is provided on the lower surface of the inner lens cover 34m.

[0444] In the lens cover 30m configured in this way, a cavity 35 is provided in the space between the third surface 31m of the lens cover 30m and the fourth surface 32m of the lens cover 30m that faces the object X. In other words, the space between the outer lens cover 33m and the inner lens cover 34m corresponds to the cavity 35.

[0445] Furthermore, the thickness of the lens cover 30m will be explained in a cross-sectional view when the lens cover 30m is cut along a plane containing the optical axis A1, that is, in the cross-sectional view shown in Figure 47(b). In this cross-sectional view, in the region where the cavity 35 is provided, the thickness from the third surface 31m to the fourth surface 32m in the direction of the optical axis A1, excluding the cavity 35, is constant.

[0446] As shown in Figure 47(b), the thickness of the outer lens cover 33m along a predetermined imaginary line parallel to the optical axis A1, i.e., the z-axis direction, is T1, and the thickness of the inner lens cover 34m is T2. The sum of T1 and T2 is constant. In this modified example, since the thickness T1 of the outer lens cover 33m is constant at any position, the value of T2 is also constant.

[0447] [Effects, etc.] In the modified 3D distance measuring module 1m, a cavity 35 is provided in the space between the third surface 31m of the lens cover 30m and the fourth surface 32m of the lens cover 30m that faces the object. In a cross-sectional view when the lens cover 30m is cut along a plane containing the optical axis A1, the thickness from the third surface 31m to the fourth surface 32m in the direction of the optical axis A1, excluding the cavity 35, is constant in the region where the cavity 35 is provided.

[0448] According to this, the 1m 3D ranging module can reduce the amount of high-intensity flare light and suppress image distortion in the resulting distance image.

[0449] (Modification 4 of Embodiment 3) Next, a modification 4 of Embodiment 3 will be described. Modification 4 of Embodiment 3 differs from Modification 1 of Embodiment 3 in that the lens cover 30n has a lens shape. Here, the lens shape includes distorted lenses whose surface is convex but does not focus at a single point. In the following, the differences from Modification 1 of Embodiment 3 will be explained in detail, and the explanation of the common points will be omitted or simplified.

[0450] [composition] A configuration example of the 3D distance measuring module 1n according to a modified example 4 of Embodiment 3 will be explained with reference to Figure 48.

[0451] Figure 48 is a cross-sectional view of the three-dimensional distance measuring module 1n according to this modified example.

[0452] The three-dimensional distance measuring module 1n according to this modified example has the same configuration as the three-dimensional distance measuring module 1j according to Modified Example 1 of Embodiment 3, except that it is equipped with a lens cover 30n instead of the lens cover 30j.

[0453] The lens cover 30n has a third surface 31n, which is the lower surface facing the lens module 20h, and a fourth surface 32n, which is the upper surface facing the object X.

[0454] The fourth surface 32n is flat, that is, a plane, and does not have a fourth inclined portion. The fourth surface 32n is a plane parallel to the xy-plane.

[0455] The lens shape is a plano-convex lens, and is convex toward the lens module 20h, that is, toward the negative z-axis direction. The convex surface of the lens shape is included in the third surface 31n and corresponds to the third inclined portion 311n. In other words, the third surface 31n includes a third inclined portion 311n that is inclined toward the lens module 20h as it moves away from the optical axis A1 of the lens 21.

[0456] Furthermore, the optical axis A2 of the lens cover, that is, the optical axis A2 of the lens shape, coincides with the optical axis A1 of the lens of the lens module 20h.

[0457] [Effects, etc.] In the three-dimensional distance measuring module 1n according to this modified example, the shape of the third surface 31n includes a lens shape, and the optical axis A1 of the lens cover 30n coincides with the optical axis A2 of the lens on the third surface 31n.

[0458] According to this, the 3D ranging module 1n can reduce the amount of high-intensity flare light and suppress image distortion in the resulting distance image. In particular, if the lens shape is such that it focuses at a single point, image distortion in the distance image can be further suppressed.

[0459] (Embodiment 4) Next, Embodiment 4 will be described. Embodiment 4 differs from Embodiment 1 mainly in that multiple light sources 10 are provided. In the following, the differences from Embodiment 1 will be explained in detail, and the explanation of the common points will be omitted or simplified.

[0460] An example of the configuration of the 3D distance measuring module 1p according to Embodiment 4 will be explained with reference to Figure 49.

[0461] Figure 49 is a top view and a cross-sectional view of the 3D distance measuring module 1p according to this embodiment.

[0462] More specifically, Figure 49(a) is a top view of the 3D ranging module 1p, and Figure 49(b) is a cross-sectional view of the 3D ranging module 1p along the XLIXb-XLIXb line in Figure 49(a).

[0463] The 3D distance measuring module 1p according to this embodiment has the same configuration as the 3D distance measuring module 1 according to Embodiment 1, except that it is equipped with a plurality of light sources 10 and is equipped with a light-shielding member 51p instead of the light-shielding member 51.

[0464] The 3D distance measuring module 1p is equipped with four light sources 10. The distance between each of the four light sources 10 and the optical axis A1 is equal to the distance between each of the other three light sources 10 and the optical axis A1.

[0465] As shown in the top view of Figure 49(a), the four light sources 10 are positioned relative to the lens module 20 on the positive x-axis and positive y-axis, on the positive x-axis and negative y-axis, on the negative x-axis and positive y-axis, and on the negative x-axis and negative y-axis, respectively.

[0466] The light-shielding member 51p is a member provided in contact with the upper part of the substrate 40. The light-shielding member 51p is provided between the four light sources 10 and the lens module 20. In the top view shown in Figure 49(a), the light-shielding member 51p is a rectangular frame-shaped member surrounding the lens module 20. Except for its shape, the light-shielding member 51p has the same configuration as the light-shielding member 51.

[0467] (Embodiment 5) Next, Embodiment 5 will be described. Embodiment 5 differs from Embodiment 1 in that it is equipped with a lens cover 30h instead of a lens cover 30. In the following, the differences from Embodiment 1 will be explained in detail, and the explanation of the common points will be omitted or simplified.

[0468] An example of the configuration of the 3D distance measuring module 1q according to Embodiment 5 will be explained with reference to Figure 50.

[0469] Figure 50 is a cross-sectional view of the 3D distance measuring module 1q according to this embodiment.

[0470] The 3D distance measuring module 1q according to this embodiment has the same configuration as the 3D distance measuring module 1 according to Embodiment 1, except that it is equipped with a lens cover 30h instead of a lens cover 30.

[0471] Thus, the 3D distance measuring module 1q comprises a light source 10, a lens module 20, and a lens cover 30h. The light source 10 emits laser light. The lens module 20 includes a lens 21 that focuses the light reflected by the object from the emitted laser light, an image sensor 23 that receives the light focused by the lens 21, and a lens barrel 22 that encloses the space between the lens 21 and the image sensor 23 and supports the lens 21. The lens cover 30h is located between the lens module 20 and the object and is transparent to the wavelength of the laser light. In a cross-sectional view when the lens barrel 22 is cut along a plane containing the optical axis A1 of the lens 21, the first surface 221 of the lens barrel 22 facing the object includes a first inclined portion 222 that inclins away from the lens cover 30h as it moves away from the optical axis A1. The third surface 31h of the lens cover 30h facing the lens module 20 includes a third inclined portion 311h that is inclined to move away from the lens module 20 as it moves away from the optical axis A1 of the lens 21.

[0472] As a result, when the laser light reflected by the object X corresponding to the bright spot is reflected by the first surface 221 (first inclined portion 222), the light (intensity flare light) reaching the lens 21 and image sensor 23 is suppressed. Furthermore, when the laser light reflected by the object X corresponding to the bright spot is reflected by the third surface 31h (third inclined portion 311h), the light (intensity flare light) reaching the lens 21 and image sensor 23 is suppressed. In other words, since the amount of intensity flare light reaching the lens 21 and image sensor 23 is suppressed, a 3D distance measuring module 1q can be realized in which the occurrence of distance miscalculations is suppressed.

[0473] Furthermore, in a cross-sectional view when the lens barrel 22 is cut along the plane containing the optical axis A1 of the lens 21, the angle between the first inclined portion 222 and the surface of the lens cover 30h facing the lens module 20 (third surface 31h) is 30 degrees or more. More specifically, the angle between the first inclined portion 222 and the third inclined portion 311h of the third surface 31h is 30 degrees or more. In other words, it is desirable that β+ζ is 30 degrees or more. In this case, the light (intensity flare light) reaching the lens 21 and the image sensor 23 is further suppressed. In other words, since the amount of intensity flare light reaching the lens 21 and the image sensor 23 is further suppressed, a 3D distance measuring module 1q can be realized in which the occurrence of distance miscalculations is further suppressed.

[0474] (Other embodiments) The three-dimensional distance measuring modules relating to one or more aspects of this disclosure have been described above based on embodiments and modifications, but this disclosure is not limited to embodiments and modifications. Without departing from the spirit of this disclosure, various modifications that a person skilled in the art can conceive of may be applied to each embodiment and modification, and forms constructed by combining components from different embodiments and modifications may also be included within the scope of one or more aspects of this disclosure.

[0475] Furthermore, the above embodiments and modifications can be modified, replaced, added, omitted, etc., within the scope of the claims or equivalents thereof. [Industrial applicability]

[0476] This disclosure is suitable for distance measuring and imaging devices, such as video cameras, digital cameras, or distance measuring systems. [Explanation of symbols]

[0477] 1, 1a, 1b, 1c, 1d, 1f, 1g, 1h, 1j, 1k, 1m, 1n, 1p, 1q, 1x 3D distance measuring module L, L1 reflected light X, Y Object 10 light source 20, 20a, 20b, 20c, 20h lens modules 21 lenses 22, 22a, 22b, 22c, 22h Telescope tube 23 Image sensor 30, 30h, 30j, 30k, 30m, 30n lens cover 31, 31h, 31j, 31k, 31m, 31n 3rd side 32h, 32j, 32k, 32n 4th side 33m outer lens cover 34m Inner Lens Cover 35 Cavity 40, 40a, 40d, 40f, 40ff, 40g, 40x substrates 41, 41a, 41d, 41f, 41ff, 41g, 41x aperture 42, 42d, 42g, side 2 51, 51p Light-shielding material 52 Board holding part 53 Side view of the enclosure 54 Bottom of the enclosure 60 control units 61 Drive control unit 62 Frame Control Unit 63 Arithmetic section 64 Distance Image Generation Unit 80 Auxiliary lines A1, A2 optical axis 100 3D Distancing Systems 211 Center 221, 221a, 221b, 221c, 221h 1st page 222, 222a, 222b, 222c 1st slope 223 Inner surface 231 rectangle 311h, 311j, 311k, 311m, 311n 3rd slope 321h 4th slope 422g 2nd slope

Claims

1. A light source that emits laser light, A lens module including a lens that focuses the light reflected by an object from the irradiated laser beam, an image sensor that receives the light focused by the lens, and a lens barrel that encloses the space between the lens and the image sensor and supports the lens, The lens module and the object are positioned and have a lens cover that is transparent to the wavelength of the laser light, In a cross-sectional view when the lens barrel is cut along a plane containing the optical axis of the lens, The first surface of the lens barrel facing the object includes a first inclined portion that slopes away from the lens cover as it moves away from the optical axis. 3D distance measuring module.

2. The first inclined portion is formed over the entire surface of the first surface. The three-dimensional distance measuring module according to claim 1.

3. The full width at half maximum of the light scattering angle of the laser beam on the first surface is 45 degrees or more. A three-dimensional distance measuring module according to claim 1 or 2.

4. In the aforementioned cross-sectional view, The angle between the first inclined portion and the surface of the lens cover facing the lens module is 30 degrees or more. The three-dimensional distance measuring module according to claim 3.

5. In the aforementioned cross-sectional view, The first inclined portion is linear. A three-dimensional distance measuring module according to claim 1 or 2.

6. When viewed from the direction of the optical axis, The outer shape of the lens barrel is similar in shape to the outer shape of the image sensor. The degree of inclination of the first inclined portion from the plane perpendicular to the optical axis has a positive correlation with the distance between the optical axis and the outer end of the lens barrel. A three-dimensional distance measuring module according to claim 1 or 2.

7. The full width at half maximum of the light scattering angle of the laser beam on the first surface is 7 degrees or less. A three-dimensional distance measuring module according to claim 1 or 2.

8. When viewing the lens from the object side of the lens cover, When ε is the maximum angle between the optical axis and the direction in which the front side of the lens can be seen, The angle between the first inclined portion and the plane perpendicular to the optical axis is ε / 2 or greater. The three-dimensional distance measuring module according to claim 7.

9. The lens cover has a member having an opening that encloses the lens when the lens is viewed from the lens cover in the direction of the optical axis of the lens, In the cross-sectional view obtained when the lens barrel is cut along a plane including the optical axis of the lens, Let B be the distance between the outer end of the lens and the outer end of the aperture. Let H1 be the distance between the lens cover and the center of the lens. Let H2 be the distance between the lens cover and the second surface of the member facing the lens cover. When the angle between the line connecting the center of the lens and the outer edge of the image sensor and the optical axis is θ, The relationship (H1 + H2) * tanθ ≤ B is satisfied. A three-dimensional distance measuring module according to claim 1 or 2.

10. The third surface of the lens cover facing the lens module includes a third inclined portion that slopes away from the lens module as it moves away from the optical axis. A three-dimensional distance measuring module according to claim 1 or 2.

11. A light source that emits laser light, A lens that focuses the light reflected by the object from the irradiated laser beam, An image sensor that receives light focused by the aforementioned lens, A lens cover, which is transparent to the wavelength of the laser light, is positioned between the lens and the object. The lens cover has a member having an opening that encloses the lens when the lens is viewed from the lens cover in the direction of the optical axis of the lens, In a cross-sectional view when the lens is cut along a plane including the optical axis, Let B be the distance between the outer end of the lens and the outer end of the aperture. Let H1 be the distance between the lens cover and the center of the lens. Let H2 be the distance between the lens cover and the second surface of the member facing the lens cover. When the angle between the line connecting the center of the lens and the outer edge of the image sensor and the optical axis is θ, The relationship (H1 + H2) * tanθ ≤ B is satisfied. 3D distance measuring module.

12. When viewed from the direction of the optical axis, The outer shape of the opening is barrel-shaped. The three-dimensional distance measuring module according to claim 11.

13. In the aforementioned cross-sectional view, The second surface includes a second inclined portion that slopes away from the lens cover as it moves away from the optical axis. A three-dimensional distance measuring module according to claim 11 or 12.

14. A light source that emits laser light, A lens module including a lens that focuses the light reflected by an object from the irradiated laser beam, an image sensor that receives the light focused by the lens, and a lens barrel that encloses the space between the lens and the image sensor and supports the lens, The lens module and the object are positioned and have a lens cover that is transparent to the wavelength of the laser light, The third surface of the lens cover facing the lens module includes a third inclined portion that slopes away from the lens module as it moves away from the optical axis of the lens. 3D distance measuring module.

15. When viewed from the direction of the optical axis, The third inclined portion is formed over the entire region where the third inclined portion and the lens module overlap. The three-dimensional distance measuring module according to claim 14.

16. The fourth surface of the lens cover facing the object is flat. A three-dimensional distance measuring module according to claim 14 or 15.

17. When viewed from the direction of the optical axis, The outer shape of the third inclined portion is similar in shape to the outer shape of the image sensor. The degree of inclination of the third inclined portion from the plane perpendicular to the optical axis has a positive correlation with the distance between the optical axis and the outer end of the third inclined portion. A three-dimensional distance measuring module according to claim 14 or 15.

18. A cavity is provided in the space between the third surface of the lens cover and the fourth surface of the lens cover facing the object. In a cross-sectional view obtained by cutting the lens cover along the plane containing the optical axis, the thickness from the third surface to the fourth surface in the direction of the optical axis, excluding the cavity, is constant in the region where the cavity is provided. A three-dimensional distance measuring module according to claim 14 or 15.

19. The shape of the third surface includes a lens shape, The optical axis of the lens cover coincides with the optical axis of the lens. A three-dimensional distance measuring module according to claim 14 or 15.

20. A three-dimensional distance measuring module according to claim 1, 2, 11, 12, 14, or 15 is provided, The three-dimensional distance measuring module has a calculation unit that calculates the distance from the light source to the object based on the travel time of the laser beam. 3D distance measuring system.

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