Light projection unit and distance measuring device

Abstract

To provide a distance measuring device which can be easily miniaturized while increasing the number of light projection devices.SOLUTION: A light projection unit comprises a plurality of light projection devices and a housing that holds the light projection devices. The plurality of light projection devices is arranged along a first axis. The housing includes a pair of attachment portions that are arranged on both sides of the plurality of light projection devices along the first axis and to which a pair of outer light projection devices are respectively attached. The light projection device includes a base provided on a first side along the first axis, a first fixing element provided on the first side of the base, a first fixing element provided on a second side, and a pair of adjustment shafts coaxially protruding from the first side and the second side for adjusting a projection direction of light. The housing includes a bearing portion that receives the adjustment shaft. The attachment portion has a shaft hole for receiving the outer adjustment shaft of the light projection device, and a through-hole for passing a second fixing element engaged with the first fixing element.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] FIELD An embodiment of the present invention relates to a light projecting unit and a distance measuring device. [Background technology]

[0002] Conventionally, a distance measuring device has been disclosed in which a scanning type light projecting device and a light receiving device are configured non-coaxially. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-164543 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to extend the measurement distance of a distance measuring device while maintaining eye safety, it is necessary to increase the number of projectors. However, increasing the number of projectors makes it difficult to miniaturize the distance measuring device.

[0005] The problem to be solved by the present invention is to provide a distance measuring device that can be easily miniaturized while increasing the number of light projecting devices. [Means for solving the problem]

[0006] A light-projecting unit according to an embodiment includes a plurality of light-projecting devices that project light and a housing that holds the light-projecting devices. The plurality of light-projecting devices are identical in structure and arranged side by side along a first axis. The housing has a pair of mounting portions that are arranged on both sides of the plurality of light-projecting devices along the first axis and to which a pair of outer light-projecting devices are respectively attached by fasteners including a first fixing element and a second fixing element that engage with each other. The light-projecting devices include a base provided on a first side along the first axis, a first fixing element commonly provided on the first side of the base, a first fixing element provided on a second side along the first axis opposite the base, and a pair of adjustment shafts that protrude coaxially from the first side and the second side to adjust the light projection direction around an axis parallel to the first axis. The housing has a bearing portion that receives one of the pair of adjustment shafts. The mounting portion has a shaft hole that receives an adjustment shaft on the outside of the floodlight device adjacent to the mounting portion, and a through hole through which one of the first fixing element and the second fixing element passes. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing a distance measuring device according to the first embodiment, illustrating a state before adjustment of the irradiation area of ​​a light projecting device and the image plane area of ​​a light receiving device. [Figure 2] FIG. 2 is a schematic diagram showing the distance measuring device according to the first embodiment, illustrating the state after adjustment of the irradiation area of ​​the light projecting device and the image plane area of ​​the light receiving device. [Figure 3] FIG. 3 is a perspective view of the distance measuring device according to the first embodiment. [Figure 4] FIG. 4 is a diagram showing the optical system of the light projecting device. [Figure 5] FIG. 5 is a perspective view of the left-side floodlight device. [Figure 6] FIG. 6 is another perspective view of the left-side floodlight device as seen from a different direction than that of FIG. [Figure 7] FIG. 7 is a perspective view of the right-side floodlight device. [Figure 8] 8 is a perspective view showing a part of the right-hand floodlight device shown in FIG. 7 in an exploded manner. [Figure 9]FIG. 9 is an exploded perspective view of the distance measuring device shown in FIG. [Figure 10] FIG. 10 is another exploded perspective view of the distance measuring device as seen from a different direction than that of FIG. [Figure 11] FIG. 11 is a front view of the distance measuring device according to the second embodiment. [Figure 12] FIG. 12 is a perspective view of the distance measuring device shown in FIG. [Figure 13] FIG. 13 is an exploded perspective view of the distance measuring device shown in FIG. [Figure 14] FIG. 14 is another exploded perspective view of the distance measuring device as seen from a different direction than that of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments will be described with reference to the drawings. In the drawings used in the following description of the embodiments, some configurations may be omitted in order to make the description easier to understand.

[0009] (First embodiment) A distance measuring device 1 according to the first embodiment will be described with reference to Figures 1, 2, and 3. Figures 1 and 2 are schematic diagrams showing the distance measuring device 1 according to this embodiment. Figure 3 is a perspective view of the distance measuring device 1 according to this embodiment.

[0010] For convenience, an XYZ coordinate system is set as shown in Figures 1 and 2. The X axis is perpendicular to the paper surface of Figures 1 and 2. The Y axis is perpendicular to the X axis and extends up and down. The Z axis is perpendicular to the X axis and extends left and right. Hereinafter, the Z direction may be referred to as the forward direction, and the Y direction as the upward direction.

[0011] The distance measuring device 1 is a device for acquiring distance information to a target. The distance measuring device 1 includes light projecting devices 21 and 22 and a light receiving device 3.

[0012] As clearly shown in Fig. 3, the distance measuring device 1 is configured to have two light projecting devices 21 and 22 for one light receiving device 3. The reason that the distance measuring device 1 has two light projecting devices 21 and 22 is to extend the measurement distance while ensuring eye safety immediately after light irradiation.

[0013] That is, in a configuration in which the distance measuring device 1 has only one light projector, the light intensity of the light projector needs to be increased to extend the measurement distance, but this makes it difficult to ensure eye safety immediately after irradiation.

[0014] The distance measuring device 1 ensures eye safety immediately after irradiation by synchronizing the irradiation positions of the two light-projecting devices 21, 22 to increase the amount of light on the image plane (object) while suppressing the increase in the amount of light from each of the light-projecting devices 21, 22. One possible method for synchronizing the irradiation positions of the two light-projecting devices 21, 22 is to provide an encoder on the polygon mirror and align the irradiation positions based on that encoder.

[0015] The light projecting devices 21 and 22 scan in the X direction while projecting light that spreads along the Y axis in the Z direction. The light projecting devices 21 and 22 also scan in the Y direction. Hereinafter, the X direction will also be referred to as the main scanning direction, and the Y direction will also be referred to as the sub-scanning direction. For example, the light projecting devices 21 and 22 create one of three irradiation areas TAa, TAb, and TAc that partially overlap in the sub-scanning direction by one scan in the main scanning direction. The light projecting devices 21 and 22 form the irradiation area TA as a whole by three scans in the main scanning direction.

[0016] The light receiving device 3 receives light from the image plane area IA. The light receiving device 3 has an imaging lens 4 and a two-dimensional sensor 5. The imaging lens 4 forms an image of the image plane area IA on the two-dimensional sensor 5. The two-dimensional sensor 5 acquires and outputs information about the image formed by the imaging lens 4.

[0017] The distance measuring device 1 also has a control circuit 9. The control circuit 9 controls the light projecting devices 21 and 22 and the light receiving device 3. The control circuit 9 also calculates the distance to a target in front of the distance measuring device 1 based on the scanning information of the light projecting devices 21 and 22 and the light receiving information of the light receiving device 3.

[0018] The light-projecting devices 21, 22 and the light-receiving device 3 are housed in a cover 6. The cover 6 has a cover glass 7 in front of the light-projecting devices 21, 22 and the light-receiving device 3. The cover glass 7 transmits light projected forward from the light-projecting devices 21, 22 and transmits light traveling from the image surface area IA toward the light-receiving device 3.

[0019] In the distance measuring device 1, it is necessary to align the irradiation area TA of the light projecting devices 21 and 22 with the image plane area IA of the light receiving device 3.

[0020] Fig. 1 shows the state before adjustment of the illumination area TA of the light-projecting devices 21 and 22 and the image plane area IA of the light-receiving device 3. In detail, Fig. 1 shows, as an example of the state before adjustment, a state in which the optical axes of the light-projecting devices 21 and 22 and the optical axis of the light-receiving device 3 are parallel. In this case, the illumination area TA of the light-projecting devices 21 and 22 does not cover the image area IA of the light-receiving device 3, and therefore there are areas where the distance cannot be measured.

[0021] To avoid such a situation, the light projecting devices 21 and 22 are designed to be able to adjust the light projection angle in the sub-scanning direction. That is, the light projecting devices 21 and 22 have a pair of rotation adjustment shafts 2011 and 2012 for adjusting the light projection angle in the sub-scanning direction. In FIGS. 1 to 3, only one of the rotation adjustment shafts 2011 is depicted, and the other rotation adjustment shaft 2012 is not visible and is therefore not depicted. For details about the rotation adjustment shaft 2012, see, for example, FIG. 6.

[0022] The pair of rotation adjustment shafts 2011, 2012 extend coaxially parallel to the X-axis. The pair of rotation adjustment shafts 2011, 2012 are fitted into a pair of shaft holes (not shown) provided in the housing 8. This allows the angle of the light projecting devices 21, 22 to be adjusted in the sub-scanning direction around the rotation adjustment shafts 2011, 2012. After the angle adjustment, the light projecting devices 21, 22 are fixed to the housing 8 by, for example, screws. The light projecting devices 21, 22 and the housing 8 constitute a light projecting unit.

[0023] The light receiving device 3 is also fixed to the housing 8. The light receiving device 3 has a two-dimensional sensor 5 inside its main body, and an imaging lens 4 is mounted on the main body. For example, the main body of the light receiving device 3 is fixed to the housing 8 with screws.

[0024] The housing 8 to which the light projecting devices 21 and 22 and the light receiving device 3 are fixed is covered with a cover 6 and a cover glass 7, ensuring waterproof and dustproof properties.

[0025] That is, the light-emitting unit having light-emitting devices 21, 22 and a housing 8 forms the main part of the distance measuring device 1 when a light-receiving device 3 is added, and further, a cover 6 and a cover glass 7 are added to form the distance measuring device 1.

[0026] 2 shows the state after adjustment of the illumination area TA of the light-projecting devices 21 and 22 and the image plane area IA of the light-receiving device 3. In the state after adjustment, by adjusting the angles of the light-projecting devices 21 and 22 in the sub-scanning direction, the illumination area TA of the light-projecting devices 21 and 22 covers the image area IA of the light-receiving device 3. As a result of this adjustment, it is possible to measure the distance to the target in any of the image areas of the light-receiving device 3.

[0027] Next, the optical systems of the light projecting devices 21 and 22 will be described with reference to Fig. 4. Fig. 4 is a diagram showing the optical systems of the light projecting devices 21 and 22. The optical systems of the light projecting devices 21 and 22 are the same.

[0028] The light projecting devices 21 and 22 each include a light source 203 that emits light, an optical scanner 210 that scans the light, and a pre-scanning optical system that guides the light from the light source 203 to the optical scanner 210 .

[0029] The pre-scanning optical system has a collimator lens 204, a folding mirror 205, and a cylindrical lens 206. The collimator lens 204 collimates the light emitted from the light source 203. The folding mirror 205 changes the traveling direction of the light that has passed through the collimator lens 204. The cylindrical lens 206 converges the incident light in one direction and shapes it into an elongated shape.

[0030] The optical scanner 210 includes a polygon mirror 207 and a drive motor 209. The polygon mirror 207 is a rotatable reflector having a plurality of reflecting surfaces on its circumferential surface. The drive motor 209 rotates the polygon mirror 207.

[0031] At least two of the multiple reflective surfaces of the polygon mirror 207 have different angles with respect to the rotation axis of the polygon mirror 207. For example, all of the multiple reflective surfaces have different angles with respect to the rotation axis of the polygon mirror 207.

[0032] The pre-scanning optical system (collimator lens 204, folding mirror 205, cylindrical lens 206) guides the light emitted from the light source 203 to the polygon mirror 207 of the optical scanner 210. That is, the optical axis OAa of the pre-scanning optical system is folded back by the folding mirror 205 toward the polygon mirror 207.

[0033] The optical scanner 210 scans the light in the main scanning direction by rotating the polygon mirror 207, and scans the light in the sub-scanning direction by changing the angle of the reflecting surface.

[0034] Next, details of floodlight device 21, which is located on the left side when viewed from the front, will be described with reference to Fig. 5 and Fig. 6. Fig. 5 is a perspective view of floodlight device 21. Fig. 6 is another perspective view of floodlight device 21, seen from a different direction than Fig. 5.

[0035] The light projecting device 21 has an optical scanner 210 and a light projecting device base 211 that holds the optical scanner 210. The optical scanner 210 is fixed to the light projecting device base 211 by, for example, screws.

[0036] The optical scanner 210 has a bracket 216. The bracket 216 is a cubic box-shaped body that houses the polygon mirror 207 and holds the drive motor 209.

[0037] The bracket 216 has a pair of rotation adjustment shafts 2011 and 2012. As described above, the pair of rotation adjustment shafts 2011 and 2012 extend coaxially parallel to the X-axis. One rotation adjustment shaft 2012 protrudes from the side of the bracket 216 facing the floodlight device base 211, and the other rotation adjustment shaft 2011 protrudes from the opposite side of the bracket 216.

[0038] Hereinafter, for convenience, the side of the bracket 216 that faces the floodlight device base 211 (i.e., the +X side) may be referred to as the first side, and the opposite side may be referred to as the second side (i.e., the -X side). The terms first side and second side may also be used for the floodlight device base 211. Furthermore, the second side of the floodlight device base 211 may be referred to as the component mounting side, and the first side of the floodlight device base 211 may be referred to as the side opposite to component mounting.

[0039] As described above, the pair of rotation adjustment shafts 2011, 2012 are fitted into a pair of shaft holes (not shown) provided in the housing 8. Therefore, the rotation adjustment shaft 2012 on the first side of the bracket 216 penetrates the floodlight base 211 and protrudes to the first side.

[0040] 5, bracket 216 of optical scanner 210 has two protrusions 222 protruding toward the second side. Furthermore, floodlight device base 211 has a columnar portion 223 extending toward the second side (i.e., the component mounting side). Protrusions 222 of bracket 216 and the end faces on the second side of columnar portion 223 of floodlight device base 211 are located on the same plane.

[0041] The floodlight device 21 has three pairs of fixing screw holes 2021 to 2026. The three pairs of fixing screw holes 2021 to 2026 include three fixing screw holes 2021 to 2023 on a first side and three fixing screw holes 2024 to 2026 on a second side. One of the three fixing screw holes 2021 to 2023 on the first side and the three fixing screw holes 2024 to 2026 on the second side is used to fix the floodlight device 21 to the housing 8 with a screw.

[0042] As shown in Fig. 5, one fixing screw hole 2021 on the second side is formed in the columnar portion 223 of the floodlight base 211. The remaining two fixing screw holes 2022 and 2023 on the second side are respectively formed in the two protruding portions 222 of the bracket 216. All three fixing screw holes 2024 to 2026 on the first side are formed on the first side (i.e., the side opposite to the component mounting side) of the floodlight base 211, as shown in Fig. 6.

[0043] Next, details of the floodlight device 22 located on the right side as viewed from the front will be described with reference to Figures 7 and 8. Figure 7 is a perspective view of the floodlight device 22. Figure 8 is a perspective view showing a part of the floodlight device 22 in an exploded state.

[0044] The right-side floodlight device 22 has a configuration in which a reinforcing member 212 is added to the left-side floodlight device 21. That is, in addition to the components of the floodlight device 21, the floodlight device 22 has the reinforcing member 212 and screws 2131 to 2133 that fix the reinforcing member 212 to the floodlight device 21.

[0045] When floodlight device base 211 is fixed to housing 8, floodlight device 21 is in a cantilever state. In other words, the second sides of bracket 216 and columnar portion 223 are free ends. Therefore, floodlight device 21 is vulnerable to vibrations and the like on the second side. In other words, vibration resistance is reduced.

[0046] The reinforcing member 212 is intended to reinforce the projector base 211 against a decrease in vibration resistance that occurs when the projector base 211 is fixed to the housing 8 in this manner. For example, the reinforcing member 212 is made of a flat metal plate, a resin mold, or the like.

[0047] The reinforcing member 212 has a hole 214 through which the rotation adjustment shaft 2011 passes, and holes 2151 to 2153 through which the screws 2131 to 2133 pass, respectively.

[0048] The reinforcing member 212 is fixed to the floodlight device 21 by passing a screw 2131 through a hole 2151 and tightening it into the fixing screw hole 2021, passing a screw 2132 through a hole 2152 and tightening it into the fixing screw hole 2021, and passing a screw 2133 through a hole 2153 and tightening it into the fixing screw hole 2021. As a result, the floodlight device 22 is completed.

[0049] The rotation adjustment shaft 2011 passes through the hole 214 of the reinforcing member 212 and protrudes to the second side. The rotation adjustment shaft 2011 is designed to have a length sufficient to enter and be supported in the shaft hole provided in the housing 8 even when the reinforcing member 212 is fixed to the floodlight device 21.

[0050] Next, details of the distance measuring device 1 according to this embodiment will be described with reference to Fig. 9 and Fig. 10. Fig. 9 is an exploded perspective view of the distance measuring device 1. Fig. 10 is another exploded perspective view of the distance measuring device 1 seen from a different direction than Fig. 9.

[0051] The housing 8 has a middle plate frame 801 in the center, a top plate frame 804, a bottom plate frame 805, a right side plate frame 806, and a left side plate frame 807.

[0052] The light receiving device 3 is fixed to the lower side of the middle plate frame 801 by, for example, screws.

[0053] The middle plate frame 801 has a bracket 802 on the upper side. The bracket 802 has a common shaft hole 803 that penetrates from left to right. A rotation adjustment shaft 2012 of the floodlight device 21 and a rotation adjustment shaft 2011 of the floodlight device 22 reinforced by a reinforcing member 212 are inserted into the common shaft hole 803 of the bracket 802 from both sides and precisely fitted together.

[0054] The rotation adjustment shaft 2012 of the right floodlight device 22 is inserted into and precisely fitted into the shaft hole 808 of the right side plate frame 806. The rotation adjustment shaft 2011 of the left floodlight device 21 is inserted into and precisely fitted into the shaft hole 809 of the left side plate frame 807.

[0055] The right side plate frame 806 is fixed to the middle plate frame 801 by passing a pair of screws 836 through the pair of through holes 816 and fastening them to a pair of screw holes 8011 in the middle plate frame 801. The side plate frame 806 is also fixed to the bottom plate frame 805 by passing a pair of screws 838 through the pair of through holes 818 and fastening them to a pair of screw holes 8051 in the bottom plate frame 805. The side plate frame 806 is also fixed to the top plate frame 804 by passing a pair of screws 840 through the pair of through holes 820 and fastening them to a pair of screw holes 8041 in the top plate frame 804.

[0056] Similarly, the left side plate frame 807 is fixed to the middle plate frame 801 by passing a pair of screws 837 through a pair of through holes 817 and fastening them to a pair of screw holes 8012 in the middle plate frame 801. The side plate frame 807 is also fixed to the bottom plate frame 805 by passing a pair of screws 839 through a pair of through holes 819 and fastening them to a pair of screw holes 8052 in the bottom plate frame 805. The side plate frame 807 is also fixed to the top plate frame 804 by passing a pair of screws 841 through a pair of through holes 821 and fastening them to a pair of screw holes 8042 in the top plate frame 804.

[0057] In this state, the pair of rotation adjustment shafts 2011 and 2012 of the light projecting device 22 are supported by the bracket 802 and the side plate frame 806, respectively, making it possible to adjust the light projection angle in the sub-scanning direction. After adjusting the light projection angle, the light projecting device 22 is fixed to the side plate frame 806 by passing a screw 830 through the through hole 810 and tightening it into the fixing screw hole 2024, passing a screw 831 through the through hole 811 and tightening it into the fixing screw hole 2025, and passing a screw 832 through the through hole 812 and tightening it into the fixing screw hole 2026. The through holes 810, 811, and 812 are elongated so as not to hinder the angle adjustment of the light projecting device 22.

[0058] Similarly, the light projecting device 21 has a pair of rotation adjustment shafts 2011 and 2012 that are respectively supported by the side plate frame 807 and the bracket 802, making it possible to adjust the light projection angle in the sub-scanning direction. After adjusting the light projection angle, the light projecting device 21 is fixed to the side plate frame 807 by passing a screw 833 through the through hole 813 and fastening it into the fixing screw hole 2021, passing a screw 834 through the through hole 814 and fastening it into the fixing screw hole 2022, and passing a screw 835 through the through hole 815 and fastening it into the fixing screw hole 2023. The through holes 813, 814, and 815 are elongated so as not to hinder the angle adjustment of the light projecting device 21.

[0059] The screws 830 to 835 and the fixing screw holes 2021 to 2025 respectively constitute fasteners for fixing the floodlight devices 21 and 22 to the side plate frames 806 and 807, or for fixing the reinforcing member 212 to the floodlight device 21. The screws 830 to 835 and the fixing screw holes 2021 to 2025 are merely one example of fasteners. In other words, the fasteners are not limited to the screws 830 to 835 and the fixing screw holes 2021 to 2025. For example, the fasteners may be constituted by bolts extending from the floodlight devices 21 and 22 and nuts threadedly engaged with the bolts. Furthermore, the fasteners may be constituted by other known structures.

[0060] The rotation adjustment shaft 2012 of the light projecting device 21 and the rotation adjustment shaft 2011 of the light projecting device 22 are commonly borne by a bracket 802 of the middle plate frame 801. Therefore, the light projecting device 21 and the light projecting device 22 are disposed close to each other. In other words, the horizontal dimension of the distance measuring device 1 is suppressed, and the distance measuring device 1 is configured to be compact.

[0061] In the left-side floodlight device 21, the columnar part 223 extending from the floodlight device base 211 and the bracket 216 of the optical scanner 210 are fixed to the side plate frame 807 with screws 833 to 835. Therefore, the floodlight device 21 has a structure that is resistant to vibrations and the like.

[0062] Furthermore, the floodlight device 21 is fixed to the side plate frame 807 only on the second side by screws 833 to 835, but on the first side, the rotation adjustment shaft 2012 is supported by the bracket 802 to suppress displacement, which also makes the structure resistant to vibrations, etc.

[0063] Furthermore, the right-side floodlight 22 has a floodlight base 211 fixed to the side plate frame 806 with screws 830 to 832. Therefore, the floodlight 22 would normally be in a cantilevered state and vulnerable to vibrations and the like, but the reinforcing member 212 is fixed to the columnar part 223 and the bracket 216 with screws 2131 to 2133. Therefore, the floodlight 22 is prevented from decreasing in vibration resistance.

[0064] Similarly, the right-side floodlight device 22 is fixed to the side plate frame 806 by screws 830 to 832 only on the first side, but on the second side, the rotation adjustment shaft 2011 is supported by the bracket 802 to suppress displacement, which also makes the structure resistant to vibrations, etc.

[0065] That is, although the distance measuring device 1 has two light projecting devices 21 and 22, it is configured to be small in size and the decrease in vibration resistance is also suppressed.

[0066] (Second embodiment) Next, a distance measuring device 11 according to a second embodiment will be described with reference to Fig. 11 and Fig. 12. Fig. 11 is a front view of the distance measuring device 11 according to the second embodiment. Fig. 12 is a perspective view of the distance measuring device 11 shown in Fig. 11.

[0067] In the distance measuring device 1 according to the first embodiment, the two light projecting devices 21 and 22 are arranged above the light receiving device 3. In contrast, in the distance measuring device 11 according to the second embodiment, the two light projecting devices 21 and 22 are arranged on both the left and right sides of the light receiving device 3. In this respect, the distance measuring device 11 according to the second embodiment differs from the distance measuring device 1 according to the first embodiment.

[0068] The distance measuring device 11 according to this embodiment has one light receiving device 3 and two light projecting devices 21 and 22. The configurations of the light receiving device 3 and the light projecting devices 21 and 22 are the same as those in the first embodiment. The two light projecting devices 21 and 22 are disposed on both the left and right sides of the light receiving device 3, respectively.

[0069] The light receiving device 3 is fixed to the housing 850. The light projecting devices 21 and 22 are supported by the housing 850 so that the light projection angle can be adjusted in the sub-scanning direction, and after the angle is adjusted, the light projecting devices 21 and 22 are fixed to the housing 850 by, for example, screws. The light projecting devices 21 and 22 and the housing 850 constitute a light projecting unit.

[0070] Next, details of the distance measuring device 11 according to this embodiment will be described with reference to Fig. 13 and Fig. 14. Fig. 13 is an exploded perspective view of the distance measuring device 11. Fig. 14 is another exploded perspective view of the distance measuring device 11, seen from a different direction than Fig. 13.

[0071] The housing 850 has a bottom frame 851 , a top frame 854 , a right side frame 856 , and a left side frame 857 .

[0072] The light receiving device 3 is fixed to the center of the upper side of the bottom plate frame 851 by, for example, a screw.

[0073] The bottom plate frame 851 has a pair of brackets 8521, 8522 on the upper side. The bracket 8521 is located on the right side of the light receiving device 3 and close to the light receiving device 3. The bracket 8522 is located on the left side of the light receiving device 3 and close to the light receiving device 3. The brackets 8521, 8522 have shaft holes 8531, 8532 that penetrate from left to right. The rotation adjustment shaft 2011 of the light projecting device 22, which is reinforced by the reinforcing member 212, is inserted into the shaft hole 8531 of the bracket 8521 and precisely fits thereto. The rotation adjustment shaft 2012 of the light projecting device 21 is inserted into the shaft hole 8532 of the bracket 8522 and precisely fits thereto.

[0074] The rotation adjustment shaft 2012 of the right floodlight device 22 is inserted into and precisely fitted into the shaft hole 858 of the right side plate frame 856. The rotation adjustment shaft 2011 of the left floodlight device 21 is inserted into and precisely fitted into the shaft hole 859 of the left side plate frame 857.

[0075] The right side plate frame 856 is fixed to the bottom plate frame 851 by passing a pair of screws 886 through a pair of through holes 866 and fastening them to a pair of screw holes 8511 in the bottom plate frame 851. The side plate frame 856 is also fixed to the top plate frame 854 by passing a pair of screws 890 through a pair of through holes 870 and fastening them to a pair of screw holes 8541 in the top plate frame 854.

[0076] Similarly, the left side plate frame 857 is fixed to the bottom plate frame 851 by passing a pair of screws 887 through a pair of through holes 867 and fastening them to a pair of screw holes 8512 in the bottom plate frame 851. The side plate frame 857 is also fixed to the top plate frame 854 by passing a pair of screws 891 through a pair of through holes 871 and fastening them to a pair of screw holes 8542 in the top plate frame 854.

[0077] In this state, the pair of rotation adjustment shafts 2011, 2012 of the light projecting device 22 are supported by the bracket 8521 and the side plate frame 856, respectively, making it possible to adjust the light projection angle in the sub-scanning direction. After adjusting the light projection angle, the light projecting device 22 is fixed to the side plate frame 856 by passing a screw 880 through the through hole 860 and into the fixing screw hole 2024, passing a screw 881 through the through hole 861 and into the fixing screw hole 2025, and passing a screw 882 through the through hole 862 and into the fixing screw hole 2026. The through holes 860, 861, and 862 are elongated so as not to hinder the angle adjustment of the light projecting device 22.

[0078] Similarly, the light projecting device 21 has a pair of rotation adjustment shafts 2011 and 2012 that are respectively supported by the side plate frame 857 and a bracket 8522, making it possible to adjust the light projection angle in the sub-scanning direction. After adjusting the light projection angle, the light projecting device 21 is fixed to the side plate frame 857 by passing a screw 883 through the through hole 863 and tightening it into the fixing screw hole 2021, passing a screw 884 through the through hole 864 and tightening it into the fixing screw hole 2022, and passing a screw 885 through the through hole 865 and tightening it into the fixing screw hole 2023. The through holes 863, 864, and 865 are elongated so as not to hinder the angle adjustment of the light projecting device 21.

[0079] The screws 880 to 885 and the fixing screw holes 2021 to 2025 respectively constitute fixing devices for fixing the light projecting devices 21 and 22 to the side plate frames 856 and 857, or for fixing the reinforcing member 212 to the light projecting device 21. The fixing devices are not limited to the screws 880 to 885 and the fixing screw holes 2021 to 2025. The fixing devices may be constituted by other known structures.

[0080] The rotation adjustment shaft 2012 of the light projecting device 21 is supported by a bracket 8522 of the bottom plate frame 851. In addition, the rotation adjustment shaft 2011 of the light projecting device 22 is supported by a bracket 8521 of the bottom plate frame 851. Therefore, the light projecting device 21 and the light projecting device 22 are disposed close to the light receiving device 3. In other words, the distance measuring device 11 is configured to be compact with a reduced horizontal dimension.

[0081] In the left-side light-projecting device 21, the columnar part 223 extending from the light-projecting device base 211 and the bracket 216 of the optical scanner 210 are fixed to the side plate frame 857 with screws 883 to 885. Therefore, the light-projecting device 21 has a configuration that is resistant to vibrations and the like.

[0082] Furthermore, the floodlight device 21 is fixed to the side plate frame 857 only on the second side by screws 883 to 885, but on the first side, the rotation adjustment shaft 2012 is supported by the bracket 8522 to suppress displacement, which also makes the structure resistant to vibrations, etc.

[0083] Furthermore, the right-side floodlight 22 has a floodlight base 211 fixed to the side plate frame 856 with screws 880 to 882. Therefore, the floodlight 22 would normally be in a cantilevered state and vulnerable to vibrations and the like, but the reinforcing member 212 is fixed to the columnar part 223 and the bracket 216 with screws 2131 to 2133. Therefore, the floodlight 22 is prevented from decreasing in vibration resistance.

[0084] Similarly, the right-side floodlight device 22 is fixed to the side plate frame 856 by screws 880-882 only on the first side, but on the second side, the rotation adjustment shaft 2011 is supported by a bracket 8521 to suppress displacement, which also makes the structure resistant to vibrations, etc.

[0085] That is, although the distance measuring device 11 has two light projecting devices 21 and 22, it is configured to be small in size and the decrease in vibration resistance is also suppressed.

[0086] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0087] 1... distance measuring device, 21, 22... light projecting device, 3... light receiving device, 4... imaging lens, 5... two-dimensional sensor, 6... cover, 7... cover glass, 8... housing, 9... control circuit, 11... distance measuring device, 2011, 2012... rotation adjustment shaft, 2021 to 2026... fixing screw holes, 203... light source, 204... collimator lens, 205... folding mirror, 206... cylindrical lens, 207... polygon mirror, 209... drive motor, 210... optical scanner, 211... light projecting device base, 212... reinforcing member, 2131 to 2133... screws, 214... holes, 2151 to 2153... holes, 216... bracket, 222... protrusion, 223... columnar portion, 801... middle plate frame, 8011, 8012... screw holes, 802... bracket, 803...Common shaft hole, 804...Top plate frame, 8041, 8042...Screw holes, 805...Bottom plate frame, 8051, 8052...Screw holes, 806, 807...Side plate frame, 808, 809...Shaft holes, 810-821...Through holes, 830-835...Screws, 836-841...Screws, 850...Housing, 851...Bottom plate frame, 8511, 8512...Screw holes , 8521, 8522...Bracket, 8531, 8532...Axis hole, 854...Top panel frame, 8541, 8542...Screw hole, 856, 857...Side panel frame, 858, 859...Axis hole, 860~865...Through hole, 866, 867...Through hole, 870, 871...Through hole, 880~885...Screw, 886, 887...Screw, 890, 891...Screw.

Claims

1. A light projection unit of a distance measuring device for acquiring distance information to a target, a plurality of light projecting devices that project light; a housing for holding the light projecting device, the plurality of light projecting devices have the same structure and are arranged side by side along a first axis, the housing has a pair of mounting portions disposed on both sides of the plurality of light-projecting devices along the first axis, to which an outer pair of the light-projecting devices are respectively attached by fasteners including a first fixing element and a second fixing element that engage with each other; the light projecting device has a base provided on a first side along the first axis, the first fixing element provided in common on the first side of the base, the first fixing element provided on a second side along the first axis opposite to the base, and a pair of adjustment shafts protruding coaxially from the first side and the second side to adjust the projection direction of the light around an axis parallel to the first axis; the housing has a bearing portion that receives one of the pair of adjustment shafts, the mounting portion has a shaft hole that receives the adjustment shaft on the outside of the floodlight device adjacent to the mounting portion, and a through hole through which one of the first fixing element and the second fixing element passes, Projector unit.

2. The light projecting device has the same number of first fixing elements provided coaxially on the first side and the second side. The light projection unit according to claim 1 .

3. the light projecting device further includes a reinforcing member fixed to the second side by engagement of the first fixing element and the second fixing element; The light projection unit according to claim 2 .

4. the bearing portion commonly receives the adjustment shafts of two adjacent light-projecting devices, The light projection unit according to claim 1 .

5. A light projection unit according to any one of claims 1 to 4; a light receiving device held in the housing and configured to receive light from a predetermined area; Ranging device.

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