Distance measurement module
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- SONY SEMICON SOLUTIONS CORP
- Filing Date
- 2026-01-07
- Publication Date
- 2026-07-30
Smart Images
Figure JP2026000203_30072026_PF_FP_ABST
Abstract
Description
Distance measurement module
[0001] The present disclosure relates to a distance measurement module, and more particularly to a distance measurement module capable of improving the light shielding performance between a first light receiving unit that receives measurement light and a second light receiving unit that receives reference light.
[0002] In a distance measurement module that measures distance by the ToF (Time-of-Flight) method, there is proposed a distance measurement module including a first light receiving unit that receives measurement light and a second light receiving unit that receives reference light, and measuring the distance to an object based on the time difference in the light receiving timings of the measurement light and the reference light (see, for example, Patent Document 1). Here, the measurement light is reflected light obtained by reflecting light emitted from a light emitting element by an object, and the reference light is light that has passed through the module.
[0003] Japanese Patent Application Laid-Open No. 2019-132640
[0004] As described above, in order to accurately measure distance in a distance measurement module that receives measurement light and reference light, it is important to sufficiently shield the measurement light and the reference light so that they do not leak into each other.
[0005] The present disclosure has been made in view of such a situation, and aims to improve the light shielding performance between a first light receiving unit that receives measurement light and a second light receiving unit that receives reference light.
[0006] A distance measurement module according to one aspect of the present disclosure includes: a light source unit that emits irradiation light; a first light receiving unit that receives, as measurement light, reflected light obtained by reflecting the irradiation light by an object to be measured; a second light receiving unit that receives, as reference light, a part of the irradiation light that passes through an optical path in the device; a first light shielding wall that shields a light emitting space in which the light source unit is disposed and a light receiving space in which the first light receiving unit and the second light receiving unit are disposed; and a second light shielding wall that shields the first light receiving unit and the second light receiving unit in the light receiving space.
[0007] In one aspect of this disclosure, the device includes a light source unit that emits irradiating light, a first light receiving unit that receives reflected light from an object to be measured as measurement light, a second light receiving unit that receives a portion of the irradiating light passing through a light guide path within the device as reference light, a first light-shielding wall that shields the light-emitting space in which the light source unit is located and the light-receiving space in which the first light-receiving unit and the second light-receiving unit are located, and a second light-shielding wall that shields the first light-receiving unit and the second light-receiving unit in the light-receiving space.
[0008] The distance measuring module may be a standalone device or a module integrated into another device.
[0009] This is a block diagram showing an example of the configuration of an electronic device to which this technology is applied. Figure 1 is a schematic cross-sectional view illustrating the first configuration of the distance measuring module. This is a plan view showing the arrangement of the first and second light-shielding walls. This is a view of the first light-shielding wall from the light-emitting space side. This is a perspective view showing a second configuration of the distance measuring module. This is a plan view and cross-sectional view showing a third configuration of the distance measuring module. This is a plan view and cross-sectional view showing a fourth configuration of the distance measuring module. This is a plan view and cross-sectional view showing a fifth configuration of the distance measuring module. This is a plan view and cross-sectional view showing a sixth configuration of the distance measuring module. This is a block diagram showing an example of the schematic configuration of a vehicle control system. This is an explanatory diagram showing an example of the installation positions of the external information detection unit and the imaging unit.
[0010] The following describes embodiments for implementing the technology of this disclosure (hereinafter referred to as "embodiments") with reference to the attached drawings. The description will proceed in the following order: 1. Example of electronic device configuration 2. First configuration example of distance measuring module 3. Second configuration example of distance measuring module 4. Third configuration example of distance measuring module 5. Fourth configuration example of distance measuring module 6. Fifth configuration example of distance measuring module 7. Sixth configuration example of distance measuring module 8. Application example to a mobile device
[0011] In the drawings referenced in the following explanation, identical or similar parts are denoted by the same or similar reference numerals, thereby omitting redundant explanations as appropriate. The drawings are schematic, and the relationship between thickness and planar dimensions, the ratio of the thickness of each layer, etc., may differ from the actual figures. Furthermore, there may be parts where the dimensional relationships and ratios differ between drawings.
[0012] <1. Example of Electronic Device Configuration> Figure 1 is a block diagram showing an example of the configuration of an electronic device to which this technology is applied.
[0013] The electronic device 11 in Figure 1 is a device equipped with a distance measuring function that measures the distance to the object 12 to be measured using the Time of Flight (ToF) method. The electronic device 11 may, for example, have only a distance measuring function, or it may have other functions. If it has other functions, the electronic device 11 may consist of electronic devices such as a smartphone, mobile phone, or digital camera.
[0014] The electronic device 11 includes an operation unit 21, a control unit 22, a distance measuring module 23, a display unit 24, and a storage unit 25.
[0015] The operation unit 21 includes various operating devices for operating the electronic device 11, such as switches, buttons, keyboards, and touch panels. The operation unit 21 supplies operation signals indicating the operation content to the control unit 22.
[0016] The control unit 22 includes, for example, a processor such as a CPU. The control unit 22 performs predetermined processing by, for example, controlling each part of the electronic device 11 based on operation signals from the operation unit 21, or by executing programs stored in the storage unit 25. For example, the control unit 22 performs processing to calculate the distance to the object 12 based on the output from the distance measuring module 23.
[0017] The distance measuring module 23 is a module that measures the distance to object 12. The distance measuring module 23 comprises a light source unit 31, a light source lens 32, an imaging lens 33, and a distance measuring sensor 34. The distance measuring sensor 34 comprises a timing control circuit 41, a light source control circuit 42, a light receiving unit 43, a signal change detection circuit 44, and a time measurement circuit 45.
[0018] The light source unit 31 is equipped with a VCSEL (Vertical Cavity Surface Emitting Laser) array, which is a plurality of VCSELs arranged in a planar configuration, as a light source, and emits pulsed light, which is the irradiation light, under the control of the light source control circuit 42 of the distance measuring sensor 34. A portion of the irradiation light is reflected within the distance measuring module 23 and incident on the light receiving unit 43 of the distance measuring sensor 34 as reference light. Another portion of the irradiation light passes through the light source lens 32 and irradiates the object 12, is reflected by the object 12 and passes through the imaging lens 33, and incident on the light receiving unit 43 as measurement light. Depending on the application of the distance measuring module 23, any wavelength of light such as visible light or infrared light can be used as the irradiation light, but in this embodiment, for example, near-infrared light (NIR light) with a wavelength of approximately 940 nm is used.
[0019] The light source lens 32 is a lens for the light source unit 31 and is used for focusing and shaping the light emitted from the light source unit 31.
[0020] The imaging lens 33 is a lens for the light-receiving unit 43, and it causes the image of the measurement light from the object 12 to be formed on the light-receiving surface of the light-receiving unit 43.
[0021] The distance measuring sensor 34 is a light-receiving element that receives measurement light and reference light and measures the distance to object 12.
[0022] The timing control circuit 41 is a circuit that controls the distance measurement timing of the distance measuring module 23 under the control of the control unit 22. For example, the timing control circuit 41 supplies an emission control signal to the light source control circuit 42 that controls the timing of emitting light from the light source unit 31. Also, for example, the timing control circuit 41 supplies a clock signal, as well as start and stop signals to the time measurement circuit 45 to start and stop the measurement of distance measurement time.
[0023] The light source control circuit 42 controls the timing of emission of irradiation light from the light source unit 31, as well as the amount of irradiation light.
[0024] As will be described later in Figure 2, the light-receiving unit 43 includes a first light-receiving unit 51A for measurement light and a second light-receiving unit 51B for reference light. Each pixel of the first light-receiving unit 51A receives measurement light and supplies a pixel signal corresponding to the amount of light received to the signal change detection circuit 44. Each pixel of the second light-receiving unit 51B receives a portion of the light passing through the light guide path in the device as reference light and supplies a pixel signal corresponding to the amount of light received to the signal change detection circuit 44. The first light-receiving unit 51A has a plurality of pixels arranged in two dimensions. The second light-receiving unit 51B has fewer pixels than the first light-receiving unit 51A and may be configured to be arranged in two dimensions or one dimension. The signal detected by the second light-receiving unit 51B is used to correct "distance errors" in distance information calculated from the light-receiving results of the first light-receiving unit 51A, which are derived from voltage fluctuations, temperature fluctuations, and reliability fluctuations, as well as to correct the breakdown voltage.
[0025] The signal change detection circuit 44 detects the timing (change timing) when the pixel signal changes significantly by receiving measurement light, based on a judgment level supplied from an external source, and supplies a signal indicating the detection result to the time measurement circuit 45.
[0026] The time measurement circuit 45 detects the detection time (reception time) of the measurement light based on the timing of the change in the pixel signal detected by the signal change detection circuit 44. The time measurement circuit 45 supplies a signal indicating the detection time of the measurement light for each pixel to the control unit 22.
[0027] The display unit 24 includes, for example, a display device such as a display. The display unit 24 displays, for example, the measurement results of the distance to each part of the object 12, and an operation screen for performing distance measurement.
[0028] The storage unit 25 stores data and programs necessary for processing by the control unit 22, as well as data obtained from the processing by the control unit 22. For example, the storage unit 25 stores three-dimensional distance data showing the measurement results of the distance to each part of the object 12.
[0029] <2. First Configuration Example of Distance Measuring Module> Figure 2 is a schematic cross-sectional view showing the first configuration example of the distance measuring module 23 shown in Figure 1.
[0030] In addition to the light source unit 31, light source lens 32, imaging lens 33, and distance measuring sensor 34 shown in Figure 1, the distance measuring module 23 includes a substrate 61, lens holder 62, diffractive optical element (DOE) 63, and infrared transmission filter 64. The distance measuring module 23 also includes a first light-shielding wall 71 and a second light-shielding wall 72.
[0031] A light source unit 31, a distance measuring sensor 34, and a lens holder 62 are mounted on the substrate 61. The substrate 61 is made up of, for example, a printed wiring board (PWB) or a printed circuit board (PCB) on which components such as capacitors are mounted.
[0032] Above the light source unit 31, in the direction of light emission, a light source lens 32 and a diffractive optical element 63 are fixedly positioned in a lens holder 62. The diffractive optical element 63 expands the illumination area by duplicating the irradiated light that has passed through the light source lens 32 in a direction perpendicular to the optical axis. The light source lens 32 and the diffractive optical element 63 may be metasurface elements.
[0033] The distance measuring sensor 34 has a first light receiving unit 51A for measurement light and a second light receiving unit 51B for reference light. Above the first light receiving unit 51A, an imaging lens 33 and an infrared transmission filter 64 are fixed to a lens holder 62. The measurement light, which has been reflected by the object 12, is focused by the imaging lens 33, passes through the infrared transmission filter 64, and enters the first light receiving unit 51A. The infrared transmission filter 64 is a filter plate that transmits only near-infrared wavelengths.
[0034] The lens holder 62 forms a first space, the light-emitting space 65A, and a second space, the light-receiving space 65B. The light-emitting space 65A contains the light source unit 31, the light source lens 32, and the diffractive optical element 63. The light-receiving space 65B contains the distance measuring sensor 34, the imaging lens 33, and the infrared transmission filter 64.
[0035] The lens holder 62 is integrally formed with the first light-shielding wall 71 and the second light-shielding wall 72. The first light-shielding wall 71 separates the light-emitting space 65A and the light-receiving space 65B and shields them from light. The second light-shielding wall 72 separates the light-receiving space 65B, where the distance-measuring sensor 34 is located, into the space above the first light-receiving section 51A and the space above the second light-receiving section 51B and shields them from light.
[0036] The surface of the lens holder 62, including the first light-shielding wall 71 and the second light-shielding wall 72, is coated with an absorbent material that absorbs light of the wavelength of the irradiated light. For example, the surface of the lens holder 62 can be treated with black anodizing, black electroless plating, or black chrome plating as the absorbent material. The material of the lens holder 62 itself may also be an absorbent material that absorbs light of the wavelength of the irradiated light. Examples of absorbent materials that absorb near-infrared light include lanthanum hexaboride (LaB6), cesium-doped tungsten oxide, tin-doped indium oxide (ITO), antimond-doped tin oxide (ATO), and black acrylic resin.
[0037] Figure 3 is a plan view showing the arrangement of the first light-shielding wall 71 and the second light-shielding wall 72.
[0038] The first light-shielding wall 71 has an opening 81 located on a straight line connecting the second light-receiving unit 51B for the reference light and the light source unit 31. The opening 81 forms a light guide path that directs a portion of the light emitted from the light source unit 31 to the second light-receiving unit 51B as the reference light. No components such as diodes, transistors, or integrated circuits (ICs) are placed on the substrate 61 along the straight line connecting the second light-receiving unit 51B and the light source unit 31.
[0039] The second light-shielding wall 72 separates the space above the first light-receiving section 51A from the space above the second light-receiving section 51B in the light-receiving space 65B. The thickness of the first light-shielding wall 71 and the second light-shielding wall 72 is set to a thickness that does not transmit light of the wavelength of the irradiated light, for example, a thickness of 0.2 mm or more.
[0040] Figure 4 shows the first light-shielding wall 71 as viewed from the light-emitting space 65A side.
[0041] The first light-shielding wall 71 is connected to the substrate 61 by an adhesive resin 82. The adhesive resin 82 can adopt a material having a sufficiently low reflectivity at the wavelength of the irradiated light, for example, a thermosetting or ultraviolet-curable epoxy-based adhesive resin, an acrylic-based adhesive resin, or the like. The color of the adhesive resin material is preferably black. The second light-shielding wall 72 and the substrate 61 are also connected by the same adhesive resin as the adhesive resin 82. The first light-shielding wall 71 serving as an adhesive surface to the substrate 61 and the bottom surface of the first light-shielding wall 71 may be subjected to uneven processing such as embossing to provide an antireflection function.
[0042] The opening 81 formed in the first light-shielding wall 71 is sized to guide the reference light to the second light-receiving portion 51B in an appropriate amount of light, and is formed in a rectangle with a width W1 and a height H1. The adhesive resin 82 has an opening width W2 wider than the width W1 of the opening 81 directly below the opening 81. This prevents the adhesive resin 8 from entering the opening 81. The height H1 of the opening 81 has a height that at least exceeds the upper surface position of the distance measuring sensor 34.
[0043] In the first configuration example of the distance measuring module 23 configured as described above, the reference light is guided through the opening 81 of the first light-shielding wall 71 to the second light-receiving portion 51B in an appropriate amount of light. The first light-receiving portion 51A and the second light-receiving portion 51B are completely shielded by the second light-shielding wall 72, preventing the reference light from leaking into the first light-receiving portion 51A and affecting the distance measuring accuracy. The second light-shielding wall 72 can improve the light-shielding performance between the first light-receiving portion 51A that receives the measurement light and the second light-receiving portion 51B that receives the reference light, and can improve the distance measuring accuracy.
[0044] <3. Second Configuration Example of Distance Measuring Module> FIG. 5 is a perspective view showing a second configuration example of the distance measuring module 23.
[0045] In the second configuration example, the arrangement configurations of the lens holder 62, the imaging lens 33, the diffractive optical element 63, and the infrared transmission filter 64 provided on the substrate 61 are the same as those in FIG. 2 shown in the first configuration example, and thus are omitted.
[0046] In the first configuration example described above, an opening 81 is provided in the first light-shielding wall 71, and a part of the irradiation light is guided as reference light to the second light-receiving part 51B.
[0047] In contrast, in the second configuration example, a light guide member 101 that forms a light guide path for guiding reference light from the light-emitting space 65A to the second light-receiving part 51B in the light-receiving space 65B is provided at a predetermined position of the first light-shielding wall 71. The light guide member 101 has an incident port 102A into which the reference light is incident and an exit port 102B from which the reference light exits. The incident port 102A is provided on the upper surface of the light guide member 101 in the light-emitting space 65A, and the exit port 102B is located above the second light-receiving part 51B in the light-receiving space 65B and is provided on the lower surface of the light guide member 101. An absorber that absorbs light of the wavelength of the irradiation light is coated on the outer peripheral surface (the portion marked in gray) of the light guide member 101 other than the incident port 102A and the exit port 102B, similar to the surface of the lens holder 62.
[0048] The light source unit 31 is disposed on the substrate 61 directly below the light source lens 32. The light guide member 101 is disposed on the substrate 61 such that the incident port 102A is arranged at a predetermined interval from the light source unit 31. Therefore, the light source unit 31 and the incident port 102A are disposed on the same plane, and a part of the irradiation light emitted from the light source unit 31 and reflected by the light source lens 32 or a diffractive optical element 63 (not shown), as indicated by the arrow in FIG. 5, for example, is incident on the incident port 102A as reference light. The reference light incident on the incident port 102A exits from the exit port 102B and is incident on the second light-receiving part 51B. The amount of the reference light is adjusted by the sizes (opening areas) of the incident port 102A and the exit port 102B.
[0049] In the second configuration example of the distance measuring module 23 configured as described above, light reflected by the light source lens 32 and the diffractive optical element 63 is guided to the second light receiving unit 51B with an appropriate amount of light through the light guide member 101 as reference light. The light-emitting space 65A and the light-receiving space 65B are separated by the first light-shielding wall 71, so there is no risk of any part of the irradiated light leaking into the second light receiving unit 51B other than through the light guide member 101. Since the first light receiving unit 51A and the second light receiving unit 51B are completely shielded by the second light-shielding wall 72, there is no risk of the reference light emitted from the output port 102B leaking into the first light receiving unit 51A. Therefore, the light-shielding performance of the first light receiving unit 51A that receives the measurement light and the second light receiving unit 51B that receives the reference light can be improved, and the distance measuring accuracy can be improved.
[0050] In the second configuration example described above, the light reflected by the light source lens 32 or the diffractive optical element 63 is incident on the light guide member 101 as reference light and guided to the second light receiving unit 51B. However, the reflective object that reflects the irradiated light may be an object other than the light source lens 32 or the diffractive optical element 63.
[0051] <4. Third Configuration Example of Distance Measuring Module> Figure 6 is a plan view showing a third configuration example of the distance measuring module 23, and a cross-sectional view taken along the line X-X' on the plan view.
[0052] In the third configuration example shown in Figure 6, the light guide member 141 that guides the reference light to the second light receiving unit 51B differs from the light guide member 101 in the second configuration example shown in Figure 5. The light guide member 101 in the second configuration example was configured to guide the reflected light, which is reflected by a predetermined reflective object such as the light source lens 32 and the diffractive optical element 63, to the second light receiving unit 51B as the reference light. In contrast, the light guide member 141 in the third configuration example is positioned between the light source unit 31 and the light source lens 32, and is configured to guide a portion of the illuminated light from the light source unit 31 toward the light source lens 32 to the second light receiving unit 51B. The light guide member 141 is made up of a single plate and is positioned to overlap the light source unit 31 and the second light receiving unit 51B in a plan view. The light source unit 31 and the second light receiving unit 51B are provided at different planar positions below the light guide member 141. The light guided by the light guide member 141 to the second light receiving unit 51B as a reference light may include, in addition to a portion of the irradiated light from the light source unit 31 toward the light source lens 32, reflected light from the irradiated light reflected by the light source lens 32, etc.
[0053] In the third configuration example of the distance measuring module 23 configured as described above, a portion of the light emitted from the light source unit 31 toward the light source lens 32 is guided to the second light receiving unit 51B with an appropriate amount of light through the light guide member 141 as a reference light. The light-emitting space 65A and the light-receiving space 65B are separated by the first light-shielding wall 71, so there is no risk of any portion of the emitted light leaking into the second light receiving unit 51B other than through the light guide member 141. Since the first light receiving unit 51A and the second light receiving unit 51B are completely shielded by the second light-shielding wall 72, there is no risk of the reference light leaking into the first light receiving unit 51A. Therefore, the light-shielding performance of the first light receiving unit 51A that receives the measurement light and the second light receiving unit 51B that receives the reference light can be improved, and the distance measuring accuracy can be improved.
[0054] <5. Fourth Configuration Example of the Distancing Module> Figure 7 is a plan view showing the fourth configuration example of the distance measuring module 23, and a cross-sectional view taken along the line X-X' on the plan view.
[0055] In the third configuration example shown in Figure 6, the light guide member 141 that guides the reference light to the second light receiving unit 51B and the light source lens 32 were provided separately. In contrast, the light guide member 151 in the fourth configuration example shown in Figure 7 is composed of a single plate that has a light guiding function that guides the reference light to the second light receiving unit 51B and a lens function of the light source lens 32. In plan view, the light guide member 151 includes a region in which at least the light source unit 31 and the second light receiving unit 51B overlap. In the region of the light guide member 151 that overlaps with the light source unit 31 in plan view, the same lens function (e.g., collimation function) as the light source lens 32 is realized by patterning, uneven shape, etc. The lens function of the light guide member 151 may also include the diffraction function and diffusion function of the diffractive optical element 63.
[0056] In the fourth configuration example of the distance measuring module 23 configured as described above, a portion of the irradiated light is guided to the second light receiving unit 51B with an appropriate amount of light through the light guide member 151 as a reference light. The light-emitting space 65A and the light-receiving space 65B are separated by the first light-shielding wall 71, so there is no risk of any portion of the irradiated light leaking into the second light receiving unit 51B other than through the light guide member 151. Since the first light receiving unit 51A and the second light receiving unit 51B are completely shielded by the second light-shielding wall 72, there is no risk of the reference light leaking into the first light receiving unit 51A. Therefore, the light-shielding performance of the first light receiving unit 51A, which receives the measurement light, and the second light receiving unit 51B, which receives the reference light, can be improved, and the distance measuring accuracy can be improved.
[0057] <6. Fifth Configuration Example of the Distancing Module> Figure 8 is a plan view showing the fifth configuration example of the distance measuring module 23, and a cross-sectional view along the X-X' and Y-Y' lines on the plan view.
[0058] In the fifth configuration example shown in Figure 8, the light guide member 161 has a light guiding function that guides the reference light to the second light receiving unit 51B, a lens function of the light source lens 32, and a lens function of the imaging lens 33. The light guide member 161 is made up of a single plate and is positioned in a location where the light source unit 31, the first light receiving unit 51A, and the second light receiving unit 51B overlap in a plan view. In the cross-sectional view along the line X-X', the light source unit 31 is not on the line X-X' in the plan view, but it is shown to indicate the positional relationship. In the region of the light guide member 161 that overlaps with the light source unit 31 in a plan view, the same lens function (e.g., collimation function) as the light source lens 32 is realized by patterning, uneven shape, etc. The lens function of the light guide member 161 may also include the diffraction function and diffusion function of the diffractive optical element 63. In a plan view, the region of the light guide member 161 that overlaps with the first light receiving portion 51A has the same lens function (e.g., imaging function) as the imaging lens 33, realized by patterning, uneven shapes, etc. The first light-shielding wall 71 is located between the light guide member 161 and the substrate 61 in a cross-sectional view, and is provided between the light source portion 31 and the second light receiving portion 51B in a plan view. The second light-shielding wall 72 is located between the light guide member 161 and the substrate 61 in a cross-sectional view, and is provided between the first light receiving portion 51A and the second light receiving portion 51B in a plan view.
[0059] In the adhesive 173 of region 171 (the gray-marked region), which is part of the adhesive area on the lower surface of the light guide member 161 and is bonded to the first light-shielding wall 71 and the second light-shielding wall 72, a material having a sufficiently low reflectivity at the wavelength of the irradiated light is used, similar to the adhesive resin 82 used for bonding to the substrate 61. On the other hand, in the adhesive area between the light guide member 161 and the first light-shielding wall 71, a material having a sufficiently low reflectivity at the wavelength of the irradiated light is not used for the adhesive 174 of region 172 (the dotted region), which is other than region 171. As a result, the reference light is guided to the second light-receiving unit 51B with an appropriate amount of light through region 172 within the light guide member 161. Of the reference light propagating within the light guide member 161, the light passing through region 171 is absorbed by the adhesive 173 and does not propagate to the first light-receiving unit 51A. Therefore, there is no risk of the reference light leaking into the first light-receiving unit 51A.
[0060] In the fifth configuration example of the distance measuring module 23 configured as described above, a portion of the irradiated light is guided to the second light receiving unit 51B with an appropriate amount of light as a reference light, passing through the region 172 of the light guide member 161. The light-emitting space 65A and the light-receiving space 65B are separated by the first light-shielding wall 71, so there is no risk of any portion of the irradiated light leaking into the second light receiving unit 51B from areas other than the region 172 within the light guide member 161. The first light receiving unit 51A and the second light receiving unit 51B are completely shielded by the second light-shielding wall 72, and the light propagating within the light guide member 161 is absorbed by the adhesive 173 in the region 171, so there is no risk of the reference light leaking into the first light receiving unit 51A. Therefore, the light-shielding performance of the first light receiving unit 51A, which receives the measurement light, and the second light receiving unit 51B, which receives the reference light, can be improved, and the distance measuring accuracy can be improved.
[0061] Furthermore, markings may be applied to both the upper and lower surfaces of the light guide member 161 in region 171 by laser processing, utilizing crack formation due to thermal effects. Alternatively, markings may be applied to the inside of the light guide member 161 in region 171 by laser processing (inner marking). Both markings on the upper and lower surfaces of region 171 of the light guide member 161 and inner markings may be applied. This can further reduce the amount of light propagating through region 171 within the light guide member 161.
[0062] <7. Sixth Configuration Example of the Distancing Module> Figure 9 is a plan view showing the sixth configuration example of the distance measuring module 23, and a cross-sectional view along the X-X' and Y-Y' lines on the plan view.
[0063] In the sixth configuration example shown in Figure 9, the light guide member 181 has a light guiding function that guides the reference light to the second light receiving unit 51B, a lens function of the light source lens 32, and a lens function of the imaging lens 33. The light guide member 181 is made up of a single plate and is positioned in a location where the light source unit 31, the first light receiving unit 51A, and the second light receiving unit 51B overlap in a plan view. In the cross-sectional view along the line X-X', the light source unit 31 is not on the line X-X' in the plan view, but it is shown to indicate the positional relationship. In the region of the light guide member 181 that overlaps with the light source unit 31 in a plan view, the same lens function (e.g., collimation function) as the light source lens 32 is realized by patterning, uneven shape, etc. The lens function of the light guide member 181 may also include the diffraction function and diffusion function of the diffractive optical element 63. In the region of the light guide member 181 that superimposes the first light-receiving unit 51A in a plan view, the same lens function (e.g., imaging function) as the imaging lens 33 is realized by patterning, uneven shape, etc. The first light-shielding wall 71 is located between the light guide member 181 and the substrate 61 in a cross-sectional view, and is provided between the light source unit 31 and the second light-receiving unit 51B in a plan view. The second light-shielding wall 72 is located between the light guide member 181 and the substrate 61 in a cross-sectional view, and is provided between the first light-receiving unit 51A and the second light-receiving unit 51B in a plan view.
[0064] The light guide member 181 has a notch 182 formed in at least a portion of the area that overlaps with the first light-shielding wall 71 in a plan view, and the path connecting the light source 31 and the first light-receiving unit 51A is divided by the notch 182. In the light guide member 181, the connection portion 183 (area marked in gray) that connects the light-emitting space 65A side and the light-receiving space 65B side is formed in the area close to the second light-receiving unit 51B in the area that overlaps with the first light-shielding wall 71 in a plan view. As a result, the reference light is guided to the second light-receiving unit 51B with an appropriate amount of light through the connection portion 183 in the light guide member 181. Since the path connecting the light source 31 and the first light-receiving unit 51A in the light guide member 181 is divided by the notch 182, there is no risk of the reference light leaking into the first light-receiving unit 51A. If the amount of light from the reference light passing through the connection portion 183 in the light guide member 181 is large and there is a risk of light leaking into the first light receiving portion 51A, a diffraction structure may be formed on both the upper and lower surfaces of the connection portion 183 of the light guide member 181 so that the amount and direction of the reference light are directed toward the second light receiving portion 51B.
[0065] In the sixth configuration example of the distance measuring module 23 configured as described above, a portion of the irradiated light is guided to the second light receiving unit 51B with an appropriate amount of light as a reference light through the connection portion 183 of the light guide member 181. The light-emitting space 65A and the light-receiving space 65B are separated by the first light-shielding wall 71 and the notch 182 of the light guide member 181, so there is no risk of any portion of the irradiated light leaking into the second light receiving unit 51B other than the connection portion 183 in the light guide member 181. The first light receiving unit 51A and the second light receiving unit 51B are completely shielded by the second light-shielding wall 72, so there is no risk of the reference light leaking into the first light receiving unit 51A. Therefore, the light-shielding performance of the first light receiving unit 51A that receives the measurement light and the second light receiving unit 51B that receives the reference light can be improved, and the distance measuring accuracy can be improved.
[0066] <8. Examples of Application to Mobile Devices> The technology disclosed herein (the technology) can be applied to a variety of products. For example, the technology disclosed herein may be implemented as a device mounted on any type of mobile device such as an automobile, electric vehicle, hybrid electric vehicle, motorcycle, bicycle, personal mobility device, airplane, drone, ship, or robot.
[0067] Figure 10 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a mobile control system to which the technology described herein may be applied.
[0068] The vehicle control system 12000 comprises a plurality of electronic control units connected via a communication network 12001. In the example shown in Figure 10, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an external information detection unit 12030, an internal information detection unit 12040, and an integrated control unit 12050. The functional configuration of the integrated control unit 12050 is shown in the figure, which includes a microcomputer 12051, an audio / image output unit 12052, and an in-vehicle network interface 12053.
[0069] The drivetrain control unit 12010 controls the operation of devices related to the vehicle's drivetrain according to various programs. For example, the drivetrain control unit 12010 functions as a control device for a drivetrain generating device that generates driving force for the vehicle, such as an internal combustion engine or a drive motor; a drivetrain transmission mechanism that transmits driving force to the wheels; a steering mechanism that adjusts the steering angle of the vehicle; and a braking device that generates braking force for the vehicle.
[0070] The body system control unit 12020 controls the operation of various devices mounted on the vehicle body according to various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window system, or various lamps such as headlights, reverse lights, brake lights, turn signals, or fog lights. In this case, the body system control unit 12020 may receive radio waves transmitted from a portable device that replaces a key or signals from various switches. The body system control unit 12020 receives these radio waves or signals and controls the vehicle's door lock system, power window system, lamps, etc.
[0071] The external information detection unit 12030 detects information from outside the vehicle equipped with the vehicle control system 12000. For example, an imaging unit 12031 is connected to the external information detection unit 12030. The external information detection unit 12030 causes the imaging unit 12031 to capture images of the outside of the vehicle and receives the captured images. Based on the received images, the external information detection unit 12030 may perform object detection processing such as detecting people, cars, obstacles, signs, or characters on the road surface, or distance detection processing.
[0072] The imaging unit 12031 is a light sensor that receives light and outputs an electrical signal corresponding to the amount of light received. The imaging unit 12031 can output the electrical signal as an image or as distance measurement information. The light received by the imaging unit 12031 may be visible light or invisible light such as infrared light.
[0073] The in-vehicle information detection unit 12040 detects information inside the vehicle. The in-vehicle information detection unit 12040 is connected to, for example, a driver status detection unit 12041 that detects the driver's state. The driver status detection unit 12041 includes, for example, a camera that captures images of the driver, and the in-vehicle information detection unit 12040 may calculate the driver's level of fatigue or concentration, or determine whether the driver is drowsy, based on the detection information input from the driver status detection unit 12041.
[0074] The microcomputer 12051 can calculate control target values for the drive force generator, steering mechanism, or braking device based on information inside and outside the vehicle acquired by the external information detection unit 12030 or the internal information detection unit 12040, and output control commands to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing ADAS (Advanced Driver Assistance System) functions, including collision avoidance or impact mitigation, following driving based on distance between vehicles, maintaining vehicle speed, vehicle collision warning, or vehicle lane departure warning.
[0075] Furthermore, the microcomputer 12051 can perform cooperative control for purposes such as autonomous driving, where the vehicle drives autonomously without driver intervention, by controlling the drive force generating device, steering mechanism, or braking device, etc., based on information about the vehicle's surroundings acquired by the external information detection unit 12030 or the internal information detection unit 12040.
[0076] Furthermore, the microcomputer 12051 can output control commands to the body system control unit 12020 based on external information acquired by the external information detection unit 12030. For example, the microcomputer 12051 can control the headlights according to the position of a preceding or oncoming vehicle detected by the external information detection unit 12030, and perform coordinated control aimed at reducing glare, such as switching from high beams to low beams.
[0077] The audio-image output unit 12052 transmits at least one of audio and image output signals to an output device capable of visually or audibly notifying information to the vehicle's occupants or to those outside the vehicle. In the example shown in Figure 10, the output devices include an audio speaker 12061, a display unit 12062, and an instrument panel 12063. The display unit 12062 may include, for example, at least one of an onboard display and a head-up display.
[0078] Figure 11 shows an example of the installation position of the imaging unit 12031.
[0079] In Figure 11, the imaging unit 12031 includes imaging units 12101, 12102, 12103, 12104, and 12105.
[0080] The imaging units 12101, 12102, 12103, 12104, and 12105 are installed, for example, on the front nose, side mirrors, rear bumper, back door, and the upper part of the windshield inside the vehicle 12100. The imaging unit 12101 installed on the front nose and the imaging unit 12105 installed on the upper part of the windshield inside the vehicle mainly acquire images of the front of the vehicle 12100. The imaging units 12102 and 12103 installed on the side mirrors mainly acquire images of the sides of the vehicle 12100. The imaging unit 12104 installed on the rear bumper or back door mainly acquires images of the rear of the vehicle 12100. The imaging unit 12105 installed on the upper part of the windshield inside the vehicle is mainly used for detecting preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, or lanes.
[0081] Figure 11 shows an example of the imaging range of imaging units 12101 to 12104. Imaging range 12111 indicates the imaging range of imaging unit 12101 located on the front nose, imaging ranges 12112 and 12113 indicate the imaging ranges of imaging units 12102 and 12103 located on the side mirrors, respectively, and imaging range 12114 indicates the imaging range of imaging unit 12104 located on the rear bumper or back door. For example, by superimposing the image data captured by imaging units 12101 to 12104, an overhead view image of the vehicle 12100 can be obtained.
[0082] At least one of the imaging units 12101 to 12104 may have a function for acquiring distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera consisting of multiple image sensors, or an image sensor having pixels for phase difference detection.
[0083] For example, the microcomputer 12051, based on distance information obtained from imaging units 12101 to 12104, can determine the distance to each object within the imaging range 12111 to 12114 and the temporal change of this distance (relative speed to the vehicle 12100). In particular, it can extract the closest object on the vehicle 12100's path that is traveling in approximately the same direction as the vehicle 12100 at a predetermined speed (e.g., 0 km / h or more) as the preceding vehicle. Furthermore, the microcomputer 12051 can set a predetermined distance to be maintained before the preceding vehicle and perform automatic braking control (including follow-and-stop control) and automatic acceleration control (including follow-and-start control), etc. In this way, cooperative control aimed at autonomous driving, where the vehicle drives autonomously without driver intervention, can be performed.
[0084] For example, the microcomputer 12051 can use distance information obtained from imaging units 12101 to 12104 to classify and extract three-dimensional object data related to three-dimensional objects, such as motorcycles, passenger cars, large vehicles, pedestrians, utility poles, and other three-dimensional objects, and use this data for automatic obstacle avoidance. For example, the microcomputer 12051 identifies obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. The microcomputer 12051 then determines the collision risk, which indicates the degree of risk of collision with each obstacle. If the collision risk is above a set value and there is a possibility of collision, the microcomputer 12051 can provide driving assistance to avoid collisions by outputting a warning to the driver via the audio speaker 12061 or the display unit 12062, or by performing forced deceleration or evasive steering via the drive system control unit 12010.
[0085] At least one of the imaging units 12101 to 12104 may be an infrared camera that detects infrared light. For example, the microcomputer 12051 can recognize pedestrians by determining whether or not pedestrians are present in the images captured by the imaging units 12101 to 12104. Such pedestrian recognition is performed, for example, by a procedure to extract feature points from the images captured by the imaging units 12101 to 12104 as infrared cameras, and a procedure to perform pattern matching on a series of feature points that indicate the contour of an object to determine whether or not it is a pedestrian. When the microcomputer 12051 determines that a pedestrian is present in the images captured by the imaging units 12101 to 12104 and recognizes a pedestrian, the audio-image output unit 12052 controls the display unit 12062 to superimpose a rectangular contour line for emphasis on the recognized pedestrian. The audio-image output unit 12052 may also control the display unit 12062 to display an icon indicating a pedestrian at a desired position.
[0086] The above describes an example of a vehicle control system to which the technology of this disclosure may be applied. The technology of this disclosure can be applied to the imaging unit 12031, etc., among the configurations described above. Specifically, for example, the electronic device 11 or the distance measuring module 23 in Figure 1 can be applied to the imaging unit 12031. The imaging unit 12031 is, for example, a LIDAR and is used to detect objects around the vehicle 12100 and the distance to those objects. By applying the technology of this disclosure to the imaging unit 12031, the detection accuracy of objects around the vehicle 12100 and the distance to those objects is improved. As a result, for example, collision warnings for the vehicle can be issued at an appropriate time, making it possible to prevent traffic accidents.
[0087] In this specification, a system refers to a collection of multiple components (devices, modules (parts), etc.), regardless of whether all components are located in the same enclosure. Therefore, multiple devices housed in separate enclosures and connected via a network, and a single device containing multiple modules within a single enclosure, are both considered systems.
[0088] Furthermore, the embodiments of the technology described herein are not limited to those described above, and various modifications are possible without departing from the gist of the technology described herein.
[0089] Furthermore, the effects described herein are merely illustrative and not limiting, and other effects may also occur.
[0090] The technology disclosed herein may adopt the following configurations: (1) A distance measuring module comprising: a light source unit that emits irradiating light; a first light receiving unit that receives reflected light from an object to be measured as measurement light; a second light receiving unit that receives a portion of the irradiating light passing through a light guide path within the device as reference light; a first light-shielding wall that shields the light-emitting space in which the light source unit is located from the light-receiving space in which the first light-receiving unit and the second light-receiving unit are located; and a second light-shielding wall that shields the first light-receiving unit and the second light-receiving unit from light in the light-receiving space. (2) The distance measuring module according to (1), further comprising a lens holder formed integrally with the first light-shielding wall and the second light-shielding wall. (3) The distance measuring module according to (2), wherein the lens holder is formed of an absorbing material that absorbs light of the wavelength of the irradiating light, or is coated with the absorbing material. (4) A distance measuring module according to any one of (1) to (3), further comprising a light guide member that forms the light guide path. (5) A distance measuring module according to (4), wherein the light guide member has an inlet into which the light reflected by an object in the device is incident as the reference light, and an outlet into which the reference light is emitted, the inlet being arranged on the same plane as the light source unit, and the outlet being arranged above the second light receiving unit. (6) A distance measuring module according to (5), wherein the surface of the light guide member other than the inlet and outlet is coated with an absorbing material that absorbs light of the wavelength of the light. (7) A distance measuring module according to any one of (5) to (6), further comprising a light source lens in the direction of emission of the light source unit, wherein the light reflected by the light source lens in the device is incident into the inlet as the reference light. (8) The distance measuring module according to any one of (4) to (7), wherein the light source unit further comprises a light source lens in the direction of emission, and the light guide member is disposed between the light source unit and the light source lens, and is configured to guide a portion of the irradiated light from the light source unit toward the light source lens toward the second light receiving unit. (9) The distance measuring module according to any one of (4) to (8), wherein the light guide member is composed of a single plate and is positioned to overlap with the light source unit and the second light receiving unit in a plan view.(10) The distance measuring module according to (9), wherein the plate further comprises the lens function of a light source lens. (11) The distance measuring module according to any one of (4) to (10), wherein the light guide member is composed of a single plate and is positioned to overlap with the light source unit, the first light receiving unit, and the second light receiving unit in a plan view. (12) The distance measuring module according to (11), wherein the plate further comprises the lens function of a light source lens and the lens function of an imaging lens. (13) The distance measuring module according to any one of (11) to (12), wherein the adhesive region between the plate and the second light-shielding wall and a part of the adhesive region between the plate and the first light-shielding wall are marked by laser processing. (14) The distance measuring module according to any one of (11) to (12), wherein the plate has a notch in the path connecting the light source unit and the first light receiving unit in at least a part of the region that overlaps with the first light-shielding wall in a plan view. (15) The distance measuring module according to any one of (1) to (14), wherein the first light-shielding wall has an opening that forms the light guide path. (16) The distance measuring module according to (15), wherein the opening is located on a straight line connecting the second light-receiving unit and the light-emitting unit. (17) The distance measuring module according to any one of (15) to (16), wherein the first light-shielding wall is connected to a substrate with adhesive resin, and the adhesive resin has an opening width wider than the width of the opening. (18) The distance measuring module according to any one of (15) to (17), wherein the height of the opening is greater than the upper surface position of the distance measuring sensor having the first light-receiving unit and the second light-receiving unit.
[0091] 11 Electronic device, 12 Object, 23 Distance measuring module, 31 Light source unit, 32 Light source lens, 33 Imaging lens, 34 Distance measuring sensor, 43 Light receiving unit, 51A First light receiving unit, 51B Second light receiving unit, 61 Substrate, 62 Lens holder, 63 Diffractive optical element, 64 Infrared transmission filter, 65A Light emission space, 65B Light receiving space, 71 First light shielding wall, 72 Second light shielding wall, 81 Aperture, 82 Adhesive resin, 101 Light guide member, 102A Entrance port, 102B Exit port, 141 Light guide member, 151 Light guide member, 161 Light guide member, 171, 172 Area, 173, 174 Adhesive, 181 Light guide member, 182 notch, 183 connection part
Claims
1. A distance measuring module comprising: a light source unit that emits irradiating light; a first light receiving unit that receives reflected light from an object to be measured as measurement light; a second light receiving unit that receives a portion of the irradiating light passing through a light guide path within the device as reference light; a first light-shielding wall that shields the light-emitting space in which the light source unit is located from the light-receiving space in which the first light-receiving unit and the second light-receiving unit are located; and a second light-shielding wall that shields the first light-receiving unit and the second light-receiving unit from light in the light-receiving space.
2. The distance measuring module according to claim 1, further comprising a lens holder integrally formed with the first light-shielding wall and the second light-shielding wall.
3. The distance measuring module according to claim 2, wherein the lens holder is formed of an absorbing material that absorbs light of the wavelength of the irradiated light, or is coated with the absorbing material.
4. The distance measuring module according to claim 1, further comprising a light guide member that forms the light guide path.
5. The distance measuring module according to claim 4, wherein the light guide member has an inlet into which the light reflected by an object in the device is incident as the reference light, and an outlet into which the reference light is emitted, the inlet being arranged on the same plane as the light source unit, and the outlet being arranged above the second light receiving unit.
6. The distance measuring module according to claim 5, wherein the surface of the light guide member other than the entrance and exit ports is coated with an absorbing material that absorbs light of the wavelength of the irradiated light.
7. The distance measuring module according to claim 5, further comprising a light source lens in the emission direction of the light source unit, wherein the irradiated light is reflected by the light source lens in the device and the resulting light is incident on the entrance port as the reference light.
8. The distance measuring module according to claim 4, further comprising a light source lens in the direction of emission of the light source unit, wherein the light guide member is positioned between the light source unit and the light source lens, and is configured to guide a portion of the irradiated light from the light source unit toward the light source lens toward the second light receiving unit.
9. The distance measuring module according to claim 4, wherein the light guide member is composed of a single plate and is positioned to overlap with the light source and the second light receiving unit in a plan view.
10. The distance measuring module according to claim 9, wherein the plate further comprises a lens function for a light source lens.
11. The distance measuring module according to claim 4, wherein the light guide member is composed of a single plate and is positioned to overlap with the light source, the first light receiving unit, and the second light receiving unit in a plan view.
12. The distance measuring module according to claim 11, wherein the plate further comprises the lens function of a light source lens and the lens function of an imaging lens.
13. The distance measuring module according to claim 11, wherein the bonding area between the plate and the second light-shielding wall and a portion of the bonding area between the plate and the first light-shielding wall are marked by laser processing.
14. The distance measuring module according to claim 11, wherein the plate has a notch in at least a portion of the area that overlaps with the first light-shielding wall in a plan view, in a path connecting the light source and the first light-receiving unit.
15. The distance measuring module according to claim 1, wherein the first light-shielding wall has an opening that forms the light guide path.
16. The distance measuring module according to claim 15, wherein the opening is provided at a position on a straight line connecting the second light receiving unit and the light source unit.
17. The distance measuring module according to claim 16, wherein the first light-shielding wall is connected to the substrate with an adhesive resin, and the adhesive resin has an opening width wider than the width of the opening.
18. The distance measuring module according to claim 15, wherein the height of the opening exceeds the upper surface position of the distance measuring sensor having the first light receiving unit and the second light receiving unit.