Imaging device

Abstract

To provide an imaging device capable of reducing optical axis misalignment of an optical lens relative to an imaging element caused by thermal deformation of components.SOLUTION: An imaging device comprises: a lens holder 110; a substrate 120; and a joint part 130. The lens holder 110 includes: a barrel 111 that holds the optical lens 101; and a holder base part 112 that supports the barrel 111, is joined to the substrate 120 via the joint part 130 and surrounds an imaging element 102. The substrate 120 includes: a narrow-width part 121 which surrounds a portion of the outer periphery of the imaging element 102 on the inner side of the holder base part 112; and a wide-width part 122 which is wider than the narrow-width part 121 and surrounds the remaining part of the outer periphery of the imaging element 102 on the inner side of the holder base part 112. The imaging device comprises a displacement adjustment part 160 which makes relative displacement between the barrel 111 and the substrate 120 in a direction where the imaging element 102 moves from the narrow-width part 121 toward the wide-width part 122 easier than relative displacement between the barrel 111 and the substrate 120 in the opposite direction.SELECTED DRAWING: Figure 4B

Description

[Technical field]

[0001] The present disclosure relates to an imaging device. [Background technology]

[0002] Stereo imaging devices that capture images of the same measurement target from different viewpoints have been known for some time. The stereo imaging device described in Patent Document 1 below is provided with a pair of cameras with optical lenses and imaging elements spaced apart at a certain distance, and the area where the imaging areas of the cameras overlap is the field of view. The parallax between the cameras is detected by a corresponding point search, and distance data is calculated from the parallax by an image processing means using the principle of triangulation.

[0003] In the imaging device of Patent Document 1, the center of the imaging element is offset in a predetermined direction with respect to the optical axis of the optical lens so as to enlarge the field of view. A corresponding point confirmed in one of the images captured by each camera is used as a reference point for starting a search for a corresponding point in the image of the other camera. This ensures a sufficient field of view and enables high-speed processing without increasing the cost associated with computational processing.

[0004] The camera module described in Patent Document 2 below includes a camera lens unit having a lens, a camera housing supporting the camera lens unit, and a substrate fixed to the camera housing via an adhesive. An image sensor facing the lens is attached to the substrate. The camera module includes a first notch formed in the camera housing or the substrate, an inner adhesive region to which adhesive is applied, and an outer adhesive region to which adhesive is applied.

[0005] The inner adhesive region is set on the side of the camera housing or the substrate on which the first cutout is formed that is closer to the image sensor than the first cutout. The outer adhesive region is set on the side of the camera housing or the substrate on which the first cutout is formed that is farther from the image sensor than the first cutout. This makes it possible to appropriately set the adhesive region and suppress optical axis deviation caused by the contraction of the adhesive during thermal curing. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2014-238558 A [Patent Document 2] JP 2022-165432 A Summary of the Invention [Problem to be solved by the invention]

[0007] In the above-mentioned imaging element (or image sensor), the performance of the imaging device (or camera module) has been improved, such as a wider angle of view, higher precision, and faster processing speed, resulting in a noticeable increase in the number of pixels, a decrease in the tolerance for optical axis misalignment of the optical lens, and an increase in the amount of heat generated, etc. As a result, the amount of thermal deformation of the components constituting the imaging device has increased, making it easier for the optical axis of the optical lens to be misaligned with the imaging element.

[0008] The present disclosure provides an imaging device capable of reducing misalignment of the optical axis of an optical lens with respect to an imaging element caused by thermal deformation of components. [Means for solving the problem]

[0009] One aspect of the present disclosure is an imaging device comprising a lens holder that holds an optical lens, a substrate on which an imaging element having an imaging surface that intersects the optical axis of the optical lens is mounted, and a joint that joins the lens holder to the substrate, wherein the lens holder has a barrel that holds the optical lens, and a holder base that supports the barrel and is joined to the substrate via the joint to surround the imaging element, wherein the substrate has a narrow portion that surrounds a part of the outer periphery of the imaging element inside the holder base, and a wide portion that is wider than the narrow portion and surrounds the remainder of the outer periphery of the imaging element inside the holder base, and further comprising a displacement adjustment portion that makes the relative displacement between the barrel and the substrate in the direction in which the imaging element moves from the narrow portion to the wide portion easier than the relative displacement between the barrel and the substrate in the direction in which the imaging element moves from the wide portion to the narrow portion. Effect of the Invention

[0010] According to the above aspect of the present disclosure, it is possible to provide an imaging device capable of reducing misalignment of the optical axis of an optical lens with respect to an imaging element caused by thermal deformation of components. [Brief description of the drawings]

[0011] [Figure 1] 1 is a perspective view showing a first embodiment of an imaging device according to the present disclosure. [Diagram 2] FIG. 2 is a perspective view showing the internal structure of the housing of the imaging device of FIG. [Diagram 3] 2 is a perspective view of a lens holder, a substrate, and a joint of the imaging device of FIG. 1. [Figure 4A] FIG. 4 is a cross-sectional view of the imaging device taken along line IV(A)-IV(A) in FIG. 3 . [Figure 4B] FIG. 4 is a cross-sectional view of the imaging device taken along line IV(B)-IV(B) in FIG. 3 . [Figure 5A] FIG. 4B is a cross-sectional view corresponding to FIG. 4A of a conventional imaging device. [Figure 5B] FIG. 4B is a cross-sectional view corresponding to FIG. 4A of a conventional imaging device. [Figure 6]4B is a cross-sectional view showing a first modified example of the imaging device of the first embodiment, corresponding to FIG. 4A. [Figure 7] 4B is a cross-sectional view showing a second modified example of the imaging device of the first embodiment, corresponding to FIG. 4A. [Figure 8] 4B is a cross-sectional view showing a third modified example of the imaging device of the first embodiment, corresponding to FIG. 4A. [Figure 9] 4 is a perspective view showing a fourth modified example of the imaging device of the first embodiment, the perspective view corresponding to FIG. [Figure 10] FIG. 10 is a cross-sectional view of the imaging device taken along line XX in FIG. [Figure 11] 4B and shows a cross-sectional view corresponding to FIG. 4B of a second embodiment of an imaging device according to the present disclosure. [Figure 12] 4B and shows a cross-sectional view corresponding to FIG. 4B of a third embodiment of an imaging device according to the present disclosure. [Figure 13] 4 is a perspective view corresponding to FIG. 3 and illustrating a fourth embodiment of an imaging device according to the present disclosure. [Figure 14] 13 is a perspective view showing a first modified example of the imaging device of the fourth embodiment, which corresponds to FIG. 3. [Figure 15] 13 is a perspective view showing a second modified example of the imaging device of the fourth embodiment, the perspective view corresponding to FIG. [Figure 16] 13 is a perspective view showing a third modified example of the imaging device of the fourth embodiment, the perspective view corresponding to FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, embodiments of an imaging device according to the present disclosure will be described with reference to the drawings.

[0013] [Embodiment 1] FIG. 1 is a perspective view showing an embodiment 1 of an imaging device according to the present disclosure. FIG. 2 is a perspective view showing an internal structure of a housing 150 of the imaging device 100 of FIG. 1. FIG. 3 is a perspective view of a lens holder 110, a substrate 120, and a joint 130 constituting a camera module CM of the imaging device 100 of FIG. 1. FIG. 4A is a cross-sectional view of the imaging device 100 taken along line IV(A)-IV(A) in FIG. 3, and FIG. 4B is a cross-sectional view of the imaging device 100 taken along line IV(B)-IV(B) in FIG. 3. Note that in FIG. 2, the lens holder 110 and the joint 130 are omitted in order to show the substrate 120 in the housing 150.

[0014] The imaging device 100 of this embodiment is, for example, a camera device that is attached to an autonomous vehicle or a vehicle equipped with an advanced driver assistance system (ADAS) and detects objects around the vehicle. Each figure shows a three-dimensional orthogonal coordinate system consisting of an X-axis along the width direction of the vehicle, a Y-axis along the height direction of the vehicle, and a Z-axis along the front-rear direction of the vehicle. In the following, the positional relationship of each part of the imaging device 100 may be explained using this three-dimensional orthogonal coordinate system.

[0015] The imaging device 100 includes a camera module CM including, for example, a lens holder 110 that holds an optical lens 101, a substrate 120 on which an imaging element 102 is mounted, and a joint 130 that joins the lens holder 110 to the substrate 120. The imaging elements 102 mounted on each substrate 120 have imaging surfaces 102a that are perpendicular to or intersect with the optical axes 101a of the optical lenses 101 held by the respective lens holders 110.

[0016] The imaging device 100 is, for example, a stereo camera device including a pair of left and right camera modules CM. The imaging device 100 also includes, for example, a circuit board 140 disposed between the pair of left and right camera modules CM, and a housing 150 that houses and fixes the circuit board 140 and the pair of left and right camera modules CM.

[0017] The lens holder 110 has a lens barrel 111 that holds the optical lens 101, and a holder base 112 that supports the lens barrel 111 and is joined to the substrate 120 via a joint 130 to surround the image sensor 102. The lens barrel 111 is provided, for example, in a cylindrical shape whose central axis coincides with the optical axis 101a of the optical lens 101. The holder base 112 is provided, for example, in a quadrangular tubular shape that surrounds the rectangular image sensor 102.

[0018] Furthermore, lens holder 110 has, for example, a flange portion 113 provided between lens barrel 111 and holder base portion 112. Flange portion 113 is, for example, a plate-like portion that protrudes in the radial direction of lens barrel 111, and is fixed to housing 150 of imaging device 100. Lens holder 110 is molded from a resin material such as polyphenylene sulfide (PPS) or polyphthalamide (PPA).

[0019] The substrate 120 is an imaging element substrate on which the imaging element 102 is mounted. The substrate 120 is made of a material such as glass epoxy. As shown in FIG. 4A, the substrate 120 has a narrow portion 121 that surrounds a part of the outer periphery of the imaging element 102 inside the holder base 112, and a wide portion 122 that is wider than the narrow portion 121 and surrounds the remaining part of the outer periphery of the imaging element 102 inside the holder base 112. More specifically, the narrow portion 121 surrounds two adjacent sides of the rectangular imaging element 102, and the wide portion 122 surrounds the other two adjacent sides of the rectangular imaging element 102.

[0020] More specifically, the lens barrel 111 of the lens holder 110 holds the optical lens 101 with the optical axis 101a of the optical lens 101 offset from the center 102c of the imaging surface 102a of the imaging element 102. The holder base 112 of the lens holder 110 is provided coaxially with the lens barrel 111. The narrow portion 121 of the substrate 120 surrounds a part of the outer periphery of the imaging element 102 on the opposite side to the offset side of the optical axis 101a of the optical lens 101 with respect to the center 102c of the imaging surface 102a of the imaging element 102. The wide portion 122 surrounds the remaining part of the outer periphery of the imaging element 102 on the offset side of the optical axis 101a.

[0021] In this embodiment, the offset direction of the optical axis 101a of the optical lens 101 with respect to the center 102c of the imaging surface 102a of the imaging element 102 is, for example, the inner side in the width direction (X-axis direction) of the vehicle and the lower side in the vertical direction (Y-axis direction) of the vehicle. In addition, the two sides of the imaging element 102 adjacent to the narrow width portion 121 of the substrate 120 are, for example, the upper end edge of the imaging element 102 along the width direction of the vehicle and the side end edge of the imaging element 102 along the vertical direction of the vehicle on the outer side of the width direction of the vehicle. In addition, the two sides of the imaging element 102 adjacent to the wide width portion 122 of the substrate 120 are, for example, the lower end edge of the imaging element 102 along the width direction of the vehicle and the side end edge of the imaging element 102 along the vertical direction of the vehicle on the inner side of the width direction of the vehicle.

[0022] The joint 130 can be formed using, for example, an adhesive, a solder, or the like, depending on the material of the lens holder 110. In this embodiment, the joint 130 is provided, for example, around the entire circumference of the open end of the holder base 112, and joins the entire circumference of the open end of the holder base 112 to the substrate 120.

[0023] The circuit board 140 includes, for example, a plurality of circuit elements 141 and 142. The circuit element 141 includes, for example, a signal processing element such as a microcontroller that processes an image captured by the image sensor 102, a field programmable gate array (FPGA), or an application specific integrated circuit (ASIC). The circuit element 142 includes, for example, a memory such as a ROM or a RAM.

[0024] The housing 150, for example, houses the CM camera module and the circuit board 140, and supports and fixes the CM camera module and the circuit board 140. That is, the camera module CM and the circuit board 140 are each housed in the housing 150 and fixed to the housing 150. The housing 150 includes, for example, a plurality of heat dissipation fins 151. Furthermore, by forming the housing 150 from a metal such as aluminum, it is possible to improve the heat dissipation and electromagnetic shielding properties in addition to the dustproofness. Although not shown, the housing 150 has, for example, an opening through which a wire connecting the circuit board 140 to an electronic control device of the vehicle is inserted.

[0025] 4A and 4B, the imaging device 100 includes a displacement adjustment unit 160. The displacement adjustment unit 160 makes the relative displacement between the lens barrel 111 and the substrate 120 in the direction in which the imaging element 102 moves from the narrow portion 121 to the wide portion 122 easier than the relative displacement between the lens barrel 111 and the substrate 120 in the direction in which the imaging element 102 moves from the wide portion 122 to the narrow portion 121. In this embodiment, the displacement adjustment unit 160 includes, for example, a thin portion 161 in which the thickness of a portion of the holder base 112 of the lens holder 110 adjacent to the narrow portion 121 of the substrate 120 is reduced compared to the thickness of the other portions.

[0026] For example, a wall portion constituting one side of rectangular holder base 112 facing one side of rectangular substrate 120 adjacent to narrow portion 121 can be made into thin portion 161 having a thickness thinner than the wall portions constituting the other three sides of holder base 112. More specifically, an upper wall portion of rectangular holder base 112 facing the upper edge of rectangular imaging element 102 adjacent to narrow portion 121 can be made into thin portion 161 having a thickness thinner than the left and right side wall portions and bottom wall portion of holder base 112.

[0027] The difference in thickness between the thin portion 161 and other portions of the holder base 112 can be made proportional to, for example, the offset amounts X1, Y1 of the optical axis 101a of the optical lens 101 from the center 102c of the imaging surface 102a of the imaging element 102. More specifically, for example, the difference in thickness between the thin portion 161 and other portions of the holder base 112 is increased as the offset amounts X1, Y1 of the optical axis 101a from the center 102c of the imaging surface 102a increase.

[0028] The operation of the imaging device 100 of this embodiment will be described below in comparison with a conventional imaging device.

[0029] In recent years, autonomous vehicles have been put to practical use and vehicles equipped with ADAS have become more widespread, aiming to realize a safe and comfortable automobile society. These vehicles are equipped with an imaging device 100 such as a monocular camera device or a stereo camera device that detects objects around the vehicle in order to realize functions such as an Active Emergency Braking System (AEBS), Adaptive Cruise Control (ACC), Lane Departure Prevention (LDP), and Traffic Sign Recognition (TSR).

[0030] The stereo camera device extracts feature points common to the left and right images captured by the left and right camera modules, and measures the distance to the feature points based on the parallax, which is the positional shift of the feature points in the left and right images expressed in terms of the number of pixels. Therefore, if a shift other than the parallax occurs between the left and right images, an error occurs in the measurement result of the distance to the feature points. One of the causes of the shift other than the parallax occurring between the left and right images is, for example, thermal deformation of the components of the stereo camera device due to heat from sunlight or heat from circuit elements inside the device. If the components of the stereo camera device are thermally deformed, the difference in the linear expansion coefficient between the components may cause a shift in the position of the optical axis of the optical lens on the imaging surface of the imaging element.

[0031] In addition, as the performance of stereo camera devices improves, including wider angles of view, higher accuracy, and faster processing, the tolerance for misalignment of the optical axis of the optical lens on the imaging surface of the imaging element becomes smaller, and further reduction in the optical axis misalignment is required. Furthermore, the number of pixels of the imaging element increases, and the amount of heat generated by the circuit elements that process images increases. Meanwhile, as the stereo camera device becomes smaller, the surface area of ​​the housing decreases, and the heat dissipation performance decreases. Therefore, the temperature of the components of the stereo camera increases, making them more susceptible to thermal deformation.

[0032] 5A and 5B are cross-sectional views of a conventional imaging device corresponding to FIG. 4A. In the conventional imaging device shown in FIG. 5A, the center 102c of the imaging surface 102a of the imaging element 102 and the optical axis 101a of the optical lens 101 are aligned, and the width of the substrate 120 between the holder base 112 of the lens holder 110 and the imaging element 102 is substantially constant over the entire circumference of the imaging element 102. In this case, the thermal stress TS acting on the substrate 120 between the imaging element 102 and the holder base 112 from the holder base 112 is symmetrical in the vertical and horizontal directions, and the optical axis 101a of the optical lens 101 does not shift relative to the imaging element 102.

[0033] In the conventional imaging device shown in Fig. 5B, the position of the optical axis 101a of the optical lens 101 is offset by a predetermined offset amount X1, Y1 from the center 102c of the imaging surface 102a of the imaging element 102. In this case, for example, in the vertical direction (Y-axis direction) of the vehicle, a difference occurs in the widths W1, W2 of the substrate 120 between the holder base 112 of the lens holder 110 and the imaging element 102. Also, for example, in the width direction (X-axis direction) of the vehicle, a difference occurs in the widths W3, W4 of the substrate 120 between the holder base 112 of the lens holder 110 and the imaging element 102.

[0034] 5B, the width W1 of the substrate 120 above the imaging element 102 is narrower than the width W2 of the substrate 120 below the imaging element 102 in the vertical direction of the vehicle. Also, the width W3 of the substrate 120 on the outer side of the imaging element 102 is narrower than the width W4 of the substrate 120 on the inner side in the width direction of the vehicle. In this case, when the temperatures of the substrate 120, the imaging element 102, and the lens holder 110 rise, a thermal stress TS that is approximately equal acts on the substrate 120 between the holder base 112 and the imaging element 102 in all directions from the holder base 112 outward due to the difference in the linear expansion coefficient of each part.

[0035] Furthermore, in the substrate 120, a difference in rigidity and linear expansion coefficient occurs between a portion on which the imaging element 102 is mounted and a portion between the holder base 112 and the imaging element 102. As a result, an expansion amount ΔW1 of the substrate 120 in a portion of width W1 above the imaging element 102 becomes smaller than an expansion amount ΔW2 of the substrate 120 in a portion of width W2 below the imaging element 102 (ΔW1<ΔW2). Furthermore, in the width direction of the vehicle, an expansion amount ΔW3 of the substrate 120 in a portion of width W3 on the outer side of the imaging element 102 becomes smaller than an expansion amount ΔW4 of the substrate 120 in a portion of width W4 on the inner side of the imaging element 102 (ΔW3<ΔW4).

[0036] As a result, the positions of the imaging element 102 and the center 102c of the imaging surface 102a move upward in the vertical direction of the vehicle and outward in the width direction of the vehicle. Meanwhile, since the holder base 112 of the lens holder 110 is thermally deformed uniformly in the vertical and horizontal directions, the position of the optical axis 101a of the optical lens 101 held by the lens holder 110 remains almost unchanged. As a result, an optical axis shift occurs in which the offset amounts X1 and Y1 of the optical axis 101a of the optical lens 101 with respect to the center 102c of the imaging surface 102a of the imaging element 102 increase, and the accuracy of measuring the distance and direction of the object by the imaging device decreases.

[0037] In order to solve the problems of the conventional imaging devices, the imaging device 100 of this embodiment has the following configuration. The imaging device 100 includes a lens holder 110 that holds an optical lens 101, a substrate 120 on which an imaging element 102 having an imaging surface 102a that intersects with an optical axis 101a of the optical lens 101 is mounted, and a joint 130 that joins the lens holder 110 to the substrate 120. The lens holder 110 includes a lens barrel 111 that holds the optical lens 101, and a holder base 112 that supports the lens barrel 111 and is joined to the substrate 120 via the joint 130 to surround the imaging element 102. The substrate 120 includes a narrow portion 121 that surrounds a part of the outer periphery of the imaging element 102 inside the holder base 112, and a wide portion 122 that is wider than the narrow portion 121 and surrounds the remaining part of the outer periphery of the imaging element 102 inside the holder base 112. The imaging device 100 further includes a displacement adjustment section 160 that makes the relative displacement between the lens barrel 111 and the substrate 120 in the direction in which the imaging element 102 moves from the narrow portion 121 toward the wide portion 122 easier than the relative displacement between the lens barrel 111 and the substrate 120 in the direction in which the imaging element 102 moves from the wide portion 122 toward the narrow portion 121.

[0038] With this configuration, in the imaging device 100 of this embodiment, when the temperatures of the lens holder 110 and the substrate 120 rise, thermal stress acts on the substrate 120 from the holder base 112 due to the difference in the linear expansion coefficient between the lens holder 110 and the substrate 120. Then, thermal stress acts on the narrow portion 121 and the wide portion 122 to expand their widths, but because the width of the narrow portion 121 is narrower than the width of the wide portion 122, the amount of deformation of the narrow portion 121 becomes smaller than the amount of deformation of the wide portion 122, and the imaging element 102 tries to move from the wide portion 122 toward the narrow portion 121. However, the imaging device 100 of this embodiment has a displacement adjustment unit 160.

[0039] This makes the relative displacement between lens barrel 111 and substrate 120 in the direction in which imaging element 102 moves from narrow portion 121 to wide portion 122 easier than the relative displacement between lens barrel 111 and substrate 120 in the direction in which imaging element 102 moves from wide portion 122 to narrow portion 121. As a result, displacement adjustment portion 160 promotes the movement of imaging element 102 in the direction from narrow portion 121 to wide portion 122, and offsets the movement of imaging element 102 in the direction from wide portion 122 to narrow portion 121 due to thermal stress.

[0040] This reduces optical axis deviation, which is the relative displacement between the optical axis 101a of the optical lens 101 held by the lens barrel 111 and the center 102c of the imaging surface 102a of the imaging element 102. This improves the measurement accuracy and reliability of the imaging device 100. Furthermore, it is possible to provide an imaging device 100 that can reduce optical axis deviation for any arrangement of the imaging element 102 and has high measurement accuracy and high reliability against temperature changes.

[0041] Furthermore, in the imaging device 100 of this embodiment, the displacement adjustment portion 160 includes a thin portion 161 in which the thickness of the portion adjacent to the narrow width portion 121 of the holder base 112 is made thinner than the thickness of the other portions.

[0042] With this configuration, in the holder base 112 of the lens holder 110, the rigidity of the thin portion 161 adjacent to the narrow portion 121 can be made lower than the rigidity of other portions adjacent to the wide portion 122. As a result, the thermal stress acting from the thin portion 161 to the narrow portion 121 can be made lower than the thermal stress acting from other portions of the holder base 112 to the wide portion 122. In addition, the substrate 120 can be made more easily displaced toward the wide portion 122. This makes it easier to make the relative displacement between the portion of the holder base 112 adjacent to the narrow portion 121 and the substrate 120 than the relative displacement between the other portion of the holder base 112 adjacent to the wide portion 122 and the substrate 120, thereby reducing the optical axis deviation.

[0043] In the imaging device 100 of this embodiment, the lens barrel 111 holds the optical lens 101 with the optical axis 101a offset from the center 102c of the imaging surface 102a of the imaging element 102. The holder base 112 is provided in a cylindrical shape coaxial with the lens barrel 111. The narrow width portion 121 surrounds a part of the outer periphery of the imaging element 102 on the side opposite to the offset side of the optical axis 101a with respect to the center 102c of the imaging surface 102a. The wide width portion surrounds the remaining part of the outer periphery of the imaging element 102 on the offset side of the optical axis 101a with respect to the center 102c of the imaging surface 102a.

[0044] With this configuration, the optical axis 101a is offset from the center 102c of the imaging surface 102a of the imaging element 102, thereby making it possible to provide the imaging device 100 with a wider angle of view. On the other hand, the amount of deformation of the substrate 120 due to thermal stress caused by the difference in linear expansion coefficient between the lens holder 110 and the substrate 120 of the imaging device 100 is greater in the wide portion 122 than in the narrow portion 121. However, the imaging device 100 of this embodiment has the displacement adjustment unit 160, and thus, as described above, it is possible to reduce the displacement of the center 102c of the imaging surface 102a of the imaging element 102 relative to the optical axis 101a of the optical lens 101 held by the lens holder 110, thereby reducing the optical axis deviation.

[0045] Furthermore, in the imaging device 100 of this embodiment, the displacement adjustment section 160 includes a thin-walled section 161 in which the thickness of a section adjacent to the narrow width section 121 of the holder base section 112 is reduced compared to the thickness of other sections. Furthermore, the difference between the thickness of the thin-walled section 161 of the holder base section 112 and the thickness of other sections is proportional to the offset amounts X1, Y1 of the optical axis 101a with respect to the center of the imaging surface 102a.

[0046] With this configuration, the difference between the thickness of the thin portion 161 of the holder base 112 and the thickness of other portions can be adjusted according to the offset amounts X1, Y1. Therefore, it is possible to more reliably reduce the displacement of the center 102c of the imaging surface 102a of the imaging element 102 with respect to the optical axis 101a of the optical lens 101 held by the lens holder 110, and more reliably reduce the optical axis deviation.

[0047] As described above, according to this embodiment, it is possible to provide the imaging device 100 capable of reducing the optical axis deviation of the optical lens 101 with respect to the imaging element 102 caused by thermal deformation of components. Note that the imaging device 100 of this embodiment is not limited to the configuration described above. Modifications 1 to 4 of the imaging device 100 of this embodiment will be described below with reference to Figs. 6 to 9.

[0048] 6 is a cross-sectional view corresponding to FIG. 4A showing Modification 1 of the imaging device 100 of the first embodiment. In this modification, the thin-walled portion 161 includes not only the upper wall portion of the rectangular holder base 112 adjacent to the narrow width portion 121, but also the upper ends of the left and right side walls of the holder base 112. In addition, a step is formed between the thin-walled portion 161 of the holder base 112 and the other portions. In this way, by having a step between the thin-walled portion 161 of the holder base 112 and the other portions, stress can be concentrated at the step, and the deformation of the upper wall portion of the rectangular holder base 112 becomes uniform and the deformation is promoted.

[0049] Furthermore, by adjusting the length Ly of the thin-walled portion 161 at the upper end of the left and right sidewall portions of the rectangular holder base 112, the amount of movement of the imaging element 102 relative to the holder base 112 can be adjusted even if the temperatures of the lens holder 110 and the substrate 120 of the imaging device 100 change. Therefore, in this modified example, the same effect as in the above-mentioned embodiment 1 can be achieved, and an imaging device 100 can be provided that can reduce the optical axis deviation of the optical lens 101 relative to the imaging element 102 caused by thermal deformation of components. Note that it is desirable to provide the displacement adjustment portion 160 including the thin-walled portion 161 in the width direction of the vehicle, which has a smaller tolerance for optical axis deviation.

[0050] 7 is a cross-sectional view corresponding to FIG. 4A showing Modification 2 of the imaging device 100 of the first embodiment. In this modification, the wall portions constituting the two sides of the rectangular holder base 112 facing the two sides of the rectangular substrate 120 adjacent to the narrow width portion 121 are made into thin-walled portions 161 having a thickness thinner than the wall portions constituting the other two sides of the holder base 112. More specifically, the upper wall portion and the side wall portion of the rectangular holder base 112 facing the upper end edge of the rectangular imaging element 102 adjacent to the narrow width portion 121 and the side end edge on the outer side in the width direction of the vehicle can be made into thin-walled portions 161 having a thickness thinner than the bottom wall portion of the holder base 112 and the side wall portion on the inner side in the width direction of the vehicle.

[0051] With this configuration, the thin-walled portion 161 can promote not only the downward displacement of the imaging element 102 relative to the holder base 112, but also the inward displacement of the imaging element 102 relative to the holder base 112 in the width direction of the vehicle. This can reduce the optical axis deviation in both the vertical and width directions of the vehicle. Therefore, this modification can also achieve the same effect as the above-mentioned embodiment 1, and can provide the imaging device 100 that can reduce the optical axis deviation of the optical lens 101 relative to the imaging element 102 caused by thermal deformation of the parts. The thickness of the wall portions constituting each side of the rectangular holder base 112 can be individually made different in order to realize an arbitrary rigidity difference between the walls.

[0052] Fig. 8 is a cross-sectional view corresponding to Fig. 4A showing Modification 3 of the imaging device 100 of the embodiment 1. In this modification, parts of the walls constituting the two sides of the rectangular holder base 112 facing the two sides of the rectangular substrate 120 adjacent to the narrow width portion 121 are made into thin-walled parts 161 that are thinner than the other parts of those walls and the walls constituting the other two sides of the holder base 112. Here, the lengths Ly, Lx of the thin-walled parts 161 in the width direction and up-down direction of the vehicle can be adjusted according to the offset amounts X1, Y1.

[0053] With this configuration, the thickness of the thin-walled portion 161 and other portions of the holder base 112 is fixed, and the lengths Ly, Lx of the thin-walled portion 161 are adjusted according to the offset amounts X1, Y1, thereby reducing the optical axis deviation. This eliminates the need for fine thickness adjustment of each wall portion of the holder base 112, facilitating dimensional control during manufacturing and improving dimensional accuracy. Therefore, this modification can also achieve the same effects as the above-mentioned first embodiment, and can provide an imaging device 100 that can reduce the optical axis deviation of the optical lens 101 relative to the imaging element 102 caused by thermal deformation of parts.

[0054] FIG. 9 is a perspective view corresponding to FIG. 3 showing a fourth modified example of the imaging device 100 of the first embodiment. FIG. 10 is a cross-sectional view of the imaging device 100 along the line XX in FIG. 9. In this modified example, the holder base 112 of the lens holder 110 has a cylindrical shape instead of a rectangular tubular shape. In this modified example, the displacement adjustment unit 160 also includes a thin-walled portion 161 in which the thickness of a portion adjacent to the narrow width portion 121 of the holder base 112 is reduced compared to the thickness of the other portions. Therefore, in this modified example, the same effect as in the first embodiment can be obtained, and an imaging device 100 can be provided that can reduce the optical axis deviation of the optical lens 101 with respect to the imaging element 102 caused by thermal deformation of the parts.

[0055] [Embodiment 2] Hereinafter, a second embodiment of the imaging device according to the present disclosure will be described with reference to Fig. 11. Fig. 11 is a cross-sectional view corresponding to Fig. 4B showing the second embodiment of the imaging device according to the present disclosure. In an imaging device 100A of this embodiment, the configuration of a displacement adjustment section 160A is different from the configuration of the displacement adjustment section 160 of the imaging device 100 of the above-mentioned first embodiment. Since the other configuration of the imaging device 100A of this embodiment is similar to that of the imaging device 100 of the above-mentioned first embodiment, similar parts are denoted by the same reference numerals and description thereof will be omitted.

[0056] In the imaging device 100A of this embodiment, the displacement adjustment section 160A includes a rib 162 protruding from the outer circumferential surface of a portion adjacent to the wide portion 122 of the holder base 112. With this configuration, the rigidity of the portion adjacent to the wide portion 122 of the holder base 112 becomes higher than the rigidity of the portion adjacent to the narrow portion 121 of the holder base 112.

[0057] As a result, the relative displacement between the substrate 120 and a part of the holder base 112 adjacent to the narrow portion 121 can be made easier than the relative displacement between the substrate 120 and a part of the holder base 112 having the rib 162 adjacent to the wide portion 122. Therefore, according to this embodiment, it is possible to provide the imaging device 100A that can achieve the same effect as the above-mentioned first embodiment and can reduce the optical axis deviation of the optical lens 101 with respect to the imaging element 102 caused by thermal deformation of components.

[0058] In addition, the thickness of the portion adjacent to the narrow portion 121 of the holder base 112 and the portion adjacent to the wide portion 122 can be made the same, which facilitates dimensional control during manufacturing of the imaging device 100A, improves dimensional accuracy, and improves the reliability of the effect of reducing optical axis deviation. In this embodiment, the rib 162 has a triangular shape, but the shape and number of the rib 162 are not particularly limited. In addition, the rib 162 may be provided not only on the bottom wall of the rectangular holder base 112 adjacent to the wide portion 122, but also on the side wall of the rectangular holder base 112 adjacent to the wide portion 122. In addition, the displacement adjustment unit 160A may include a thin portion 161, similar to the displacement adjustment unit 160 of the above-mentioned embodiment 1.

[0059] [Embodiment 3] Hereinafter, an embodiment 3 of an imaging device according to the present disclosure will be described with reference to Fig. 12. Fig. 12 is a cross-sectional view corresponding to Fig. 4B showing the embodiment 3 of an imaging device according to the present disclosure. In an imaging device 100B of this embodiment, the configuration of a displacement adjustment section 160B is different from the configuration of the displacement adjustment section 160 of the imaging device 100 of the above-mentioned embodiment 1. Since the other configuration of the imaging device 100B of this embodiment is similar to that of the imaging device 100 of the above-mentioned embodiment 1, similar parts are denoted by the same reference numerals and description thereof will be omitted.

[0060] In the imaging device 100B of this embodiment, the displacement adjustment section 160B includes a bent section 163 provided in a portion adjacent to the narrow width section 121 of the holder base 112. With this configuration, the rigidity of the portion adjacent to the narrow width section 121 of the holder base 112 is lower than the rigidity of the portion adjacent to the wide width section 122 of the holder base 112.

[0061] As a result, the relative displacement between the portion of the holder base 112 having the bent portion 163 adjacent to the narrow portion 121 and the substrate 120 can be made easier than the relative displacement between the part of the holder base 112 adjacent to the wide portion 122 and the substrate 120. Therefore, according to this embodiment, it is possible to provide an imaging device 100B that can achieve the same effects as those of the above-mentioned first embodiment and can reduce the optical axis deviation of the optical lens 101 with respect to the imaging element 102 caused by thermal deformation of components.

[0062] In addition, the thickness of the portion adjacent to the narrow portion 121 of the holder base 112 and the portion adjacent to the wide portion 122 can be made the same, which facilitates dimensional control during manufacturing of the imaging device 100B, improves dimensional accuracy, and improves the reliability of the effect of reducing optical axis deviation. Furthermore, by making the bent portion 163 the thin portion 161, it is possible to more easily cause a relative displacement between the portion of the holder base 112 having the bent portion 163 adjacent to the narrow portion 121 and the substrate 120, and to expand the range in which the optical axis deviation can be reduced. In addition, the bent portion 163 may be provided not only on the upper wall portion of the rectangular holder base 112 adjacent to the narrow portion 121, but also on the side wall portion of the rectangular holder base 112 adjacent to the narrow portion 121.

[0063] [Embodiment 4] Hereinafter, a fourth embodiment of the imaging device according to the present disclosure will be described with reference to Fig. 13. Fig. 13 is a perspective view corresponding to Fig. 3 showing the fourth embodiment of the imaging device according to the present disclosure. In an imaging device 100C of this embodiment, the configuration of a displacement adjustment section 160C is different from the configuration of the displacement adjustment section 160 of the imaging device 100 of the first embodiment described above. Other configurations of the imaging device 100C of this embodiment are similar to those of the imaging device 100 of the first embodiment described above, so similar parts are denoted by the same reference numerals and description thereof will be omitted.

[0064] In the imaging device 100C of this embodiment, the displacement adjustment section 160C includes a displacement allowance section 164 in which the joint strength of a portion adjacent to the narrow width section 121 of the joint section 130 is reduced compared to the joint strength of the other portions. The displacement allowance section 164 is, for example, a portion where the joint section 130 is not provided between the holder base section 112 and the substrate 120, and is provided between the substrate 120 and a part of the holder base section 112 adjacent to the narrow width section 121. The displacement allowance section 164 is, for example, a minute gap between the holder base section 112 and the substrate 120, or a surface where the holder base section 112 and the substrate 120 come into contact with each other.

[0065] With this configuration, the relative displacement between the substrate 120 and a part of the holder base 112 adjacent to the narrow portion 121 can be made easier than the relative displacement between the substrate 120 and another part of the holder base 112 adjacent to the wide portion 122. Therefore, according to this embodiment, it is possible to provide an imaging device 100C that can achieve the same effects as the above-described first embodiment and reduce the optical axis deviation of the optical lens 101 with respect to the imaging element 102 caused by thermal deformation of components.

[0066] The displacement allowance portion 164 can be formed using an adhesive having a lower rigidity than the adhesive constituting the joint portion 130. This can ensure dustproofness between the holder base portion 112 and the substrate 120. The imaging device 100C of this embodiment is not limited to the above-mentioned configuration. Modifications 1 to 3 of the imaging device 100C of this embodiment will be described below with reference to Figs. 14 to 16.

[0067] 14 is a perspective view corresponding to FIG. 3 and showing a first modified example of the imaging device 100C of the fourth embodiment. In this modified example, the joint portion 130 is formed around the entire circumference of the open end of the holder base 112. The displacement allowance portion 164 is formed by a notch 112c formed in a portion adjacent to the narrow width portion 121 of the holder base 112. In the displacement allowance portion 164 provided in the portion adjacent to the narrow width portion 121 of the holder base 112, the holder base 112 has a gap between it and the joint portion 130 and is not joined to the substrate 120.

[0068] The displacement allowance portion 164 reduces the bonding strength of the portion adjacent to the narrow width portion 121 of the joint portion 130 compared to the bonding strength of the other portions. Therefore, in this modified example, the same effect as that of the above-mentioned embodiment 1 can be achieved, and an imaging device 100 can be provided that can reduce the optical axis deviation of the optical lens 101 with respect to the imaging element 102 caused by thermal deformation of the components. The notch 112c may be filled and closed with an adhesive having a lower rigidity than the adhesive constituting the joint portion 130. This ensures dustproofness between the holder base 112 and the substrate 120. The notch 112c may be a slit.

[0069] FIG. 15 is a perspective view corresponding to FIG. 3 showing a modified example 2 of the imaging device 100C of the fourth embodiment. In this modified example, the joint 130 is not formed in a part of the wall portion constituting the two sides of the rectangular holder base 112 facing the two sides of the rectangular substrate 120 adjacent to the narrow width portion 121, and a displacement allowance portion 164 is formed. The length of each of the displacement allowance portions 164 in the width direction and the vertical direction of the vehicle can be adjusted according to the offset amounts X1 and Y1. Therefore, in this modified example, the same effect as that of the first embodiment described above can be achieved, and an imaging device 100 can be provided that can reduce the optical axis deviation of the optical lens 101 with respect to the imaging element 102 caused by thermal deformation of parts.

[0070] FIG. 16 is a perspective view corresponding to FIG. 3 showing a modified example 3 of the imaging device 100C of the embodiment 4. In this modified example, a notch 112c is provided in a part of a wall portion constituting two sides of the rectangular holder base 112 facing the two sides of the rectangular substrate 120 adjacent to the narrow width portion 121, forming a displacement allowance portion 164. The length of each of the displacement allowance portions 164 in the width direction and the vertical direction of the vehicle can be adjusted according to the offset amounts X1 and Y1. Therefore, in this modified example, the same effect as in the above-mentioned embodiment 1 can be achieved, and an imaging device 100 can be provided that can reduce the optical axis deviation of the optical lens 101 with respect to the imaging element 102 caused by thermal deformation of parts.

[0071] The above describes in detail an embodiment of the imaging device according to the present disclosure using the drawings, but the specific configuration is not limited to this embodiment, and even if there are design changes and the like within the scope that does not deviate from the gist of the present disclosure, they are included in the present disclosure. [Explanation of symbols]

[0072] 100 Imaging device 100A Imaging Device 100B Imaging device 100C Imaging device 101 Optical Lenses 101a Optical axis 102 Image sensor 102a Imaging surface 102c center 110 Lens holder 111 Telescope tube 112 Holder base 120 Substrate 121 Narrow section 122 Wide section 130 Joint 160 Displacement adjustment part 160A Displacement adjustment part 160B Displacement adjustment part 160C Displacement adjustment part 161 Thin section 162 Ribs 163 Bend 164 Displacement allowance section

Claims

1. An imaging device comprising: a lens holder for holding an optical lens; a substrate on which an imaging element having an imaging surface intersecting an optical axis of the optical lens is mounted; and a joint for joining the lens holder to the substrate, the lens holder includes a lens barrel that holds the optical lens, and a holder base that supports the lens barrel and is joined to the substrate via the joint to surround the image sensor, the substrate has a narrow portion surrounding a part of an outer periphery of the image sensor inside the holder base, and a wide portion that is wider than the narrow portion and surrounding the remainder of the outer periphery of the image sensor inside the holder base, an imaging device further comprising a displacement adjustment section that makes the relative displacement between the lens barrel and the substrate in the direction in which the imaging element moves from the narrow portion to the wide portion easier than the relative displacement between the lens barrel and the substrate in the direction in which the imaging element moves from the wide portion to the narrow portion.

2. 2. The imaging device according to claim 1, wherein the displacement adjustment portion includes a thin-walled portion having a thickness adjacent to the narrow width portion of the holder base that is thinner than the thickness of other portions.

3. The imaging device according to claim 1 , wherein the displacement adjustment portion includes a rib protruding from an outer circumferential surface of a portion of the holder base adjacent to the wide portion.

4. The imaging device according to claim 1 , wherein the displacement adjustment portion includes a bent portion provided in a portion adjacent to the narrow width portion of the holder base.

5. The imaging device according to claim 1 , wherein the displacement adjustment portion includes a displacement allowance portion in which a bonding strength of a portion adjacent to the narrow width portion of the joint is made lower than a bonding strength of the other portion.

6. the lens barrel holds the optical lens in a state where the optical axis is offset from the center of the imaging surface; the holder base is provided in a cylindrical shape coaxial with the lens barrel, the narrow portion surrounds the part of the outer periphery of the imaging element on a side opposite to an offset side of the optical axis with respect to the center of the imaging surface; 2. The imaging device according to claim 1, wherein the wide portion surrounds the remaining portion of the outer periphery of the imaging element on the offset side.

7. the displacement adjustment portion includes a thin-walled portion having a thickness adjacent to the narrow width portion of the holder base portion that is thinner than a thickness of other portions of the holder base portion, 7. The imaging device according to claim 6, wherein a difference between the thickness of the thin portion and the thickness of the other portion is proportional to an offset amount of the optical axis from the center of the imaging surface.

Images