Imaging device

Abstract

An imaging device according to one aspect of the present invention is provided with: a circuit board; an imaging element mounted on the circuit board; a lens barrel which is provided on the circuit board so as to cover the periphery of the imaging element, holds a lens, and has a dent part formed by the extrusion of an extrusion pin for extruding a molded article from a mold; and a coating member which is provided in the lens barrel and covers at least a portion of the dent part when viewed from the optical axis direction of the lens.

Description

Imaging device

[0001] The present technology relates to an imaging device mounted on, for example, a vehicle.

[0002] In an imaging device, if dust adheres to the light-guiding space between the imaging element mounted on a circuit board and the lens, or if scratches occur on the imaging element or lens, this will lead to a deterioration in image quality, and various countermeasures have been proposed.

[0003] For example, Patent Document 1 discloses an imaging device in which a semiconductor imaging element is mounted on a substrate, and a lens barrel including a light-transmitting member and a lens is arranged across an optical space from the imaging area of ​​the semiconductor imaging element, and a gap that allows an adhesive-containing liquid to penetrate outside the space surrounded by the semiconductor imaging element, the light-transmitting member, and the substrate so that an adhesive area can be formed outside the optically effective area that can be imaged in the imaging area within the optical space.

[0004] Japanese Patent Application Laid-Open No. 2008-172350

[0005] In the image pickup device described above, the lens barrel is manufactured using a molding machine that uses an injection mold. In the molding machine, parts are released after molding by pushing them out with an ejector pin. When the lens barrel is pushed out with the ejector pin, a small step is created in the dent, which can cause a part of the lens barrel to peel off and adhere to the image pickup element.

[0006] In view of the above circumstances, an object of the present technology is to provide an imaging device that can prevent dust from adhering to an imaging element.

[0007] An imaging device according to one aspect of the present technology includes a circuit board, an imaging element, a lens barrel, and a covering member. The imaging element is mounted on the circuit board. The lens barrel is provided on the circuit board so as to cover the periphery of the imaging element, holds a lens, and has an indentation caused by the extrusion of an ejector pin that pushes a molded product out of a mold. The covering member is provided on the lens barrel and covers at least a portion of the indentation when viewed from the optical axis direction of the lens.

[0008] The dent may be provided at a position on the lens barrel adjacent to the image sensor when viewed from the optical axis direction.

[0009] The lens barrel may have a filter mounting portion on which an infrared cut filter is mounted, and the dent portion may be provided on the filter mounting portion around the infrared cut filter when viewed from the optical axis direction.

[0010] The covering member may cover a peripheral edge of the dent.

[0011] The covering member may be an adhesive.

[0012] The adhesive may be provided inside the dent and on the periphery of the dent.

[0013] The lens barrel may be formed by die casting or injection molding.

[0014] The dent may be provided in a space formed by the lens barrel and the circuit board.

[0015] The adhesive may be an ultraviolet curable resin.

[0016] Fig. 1 is an exploded perspective view showing the relationship between a front case and a lens barrel of an imaging device according to a first embodiment of the present technology; Fig. 2 is an exploded perspective view showing the relationship between a circuit board and a rear case in the imaging device; Fig. 3 is a side cross-sectional view showing the lens barrel of the imaging device; Fig. 4 is a rear view showing the lens barrel of the imaging device; Fig. 5 is a diagram showing how a covering member is applied to the lens barrel of the imaging device; Fig. 6 is a rear view of a conventional lens barrel;

[0017] Hereinafter, embodiments of the present technology will be described with reference to the drawings.

[0018] First Embodiment Fig. 1 is an exploded perspective view showing the relationship between a front case 11 and a lens barrel 60 of an imaging device 100 according to a first embodiment of the present technology, and Fig. 2 is an exploded perspective view showing the relationship between a sensor board 20 and a rear case 12 in the imaging device 100. The imaging device 100 of this embodiment is configured as a camera module for in-vehicle use. In each figure, the X-axis, Y-axis, and Z-axis indicate three axial directions that are orthogonal to one another, and the Z-axis corresponds to the optical axis direction C of the imaging device 100. Of course, the directions are not limited to these settings.

[0019] The imaging device 100 is configured to be attachable to a vehicle. The imaging device 100 is disposed, for example, outside a vehicle body (attachment object) (not shown) and captures images of the front, rear, or side of the vehicle depending on the attachment position. For example, an imaging device 100 attached to the front part of the vehicle body (e.g., the front grille) captures images of the environment in front of the vehicle. An imaging device 100 attached to the rear part (e.g., above the license plate) captures images of the environment behind the vehicle. An imaging device 100 attached to the side of the vehicle (e.g., the top of a pillar (A pillar, B pillar, or the rearmost pillar of the vehicle (C pillar, D pillar)) or a side mirror) captures images of the environment to the side of the vehicle.

[0020] [Overall Configuration of Imaging Apparatus] First, a description will be given of the overall configuration of the imaging apparatus 100. As shown in Figures 1 and 2, the imaging apparatus 100 of this embodiment includes a housing 10, a sensor board 20, a shield case 50, a lens barrel 60, and the like.

[0021] The housing 10 is configured by combining a front case 11 and a rear case 12 in the Z direction. The front case 11 and the rear case 12 are typically configured as injection-molded bodies made of synthetic resin material. The imaging device 100 is fixed to a vehicle body (not shown) via a harness (not shown) attached to the rear case 12.

[0022] 1 , the front case 11 has a front surface 111 formed substantially perpendicular to the Z direction, and side surfaces 112 extending from the periphery of the front surface 111 toward the rear case 12. In this embodiment, the shape of the front surface 111 when viewed from the Z direction is substantially rectangular. The front case 11 is hollow, and a space is formed in the area surrounded by the front surface 111 and the side surfaces 112 to accommodate the sensor board 20, the shield case 50, the lens barrel 60, etc.

[0023] The front case 11 has an opening 113 at one end and an open end 114 at the opposite end. The opening 113 is formed in the center of the front surface 111. The open end 114 is formed at the end of the side surface 112 on the rear case 12 side. The open end 114 is formed in a substantially rectangular shape that corresponds to the outer shape of the front surface 111. Note that the shapes of the front surface 111 and the open end 114 are not limited to rectangular, and may be formed in other shapes such as circular or triangular.

[0024] The rear case 12 is fixed between the front case 11 and a harness (not shown). As shown in FIG. 2 , the rear case 12 is an electromagnetic shielding case, and has a rear surface 121 disposed substantially perpendicular to the optical axis Z direction, and side surfaces 122 extending from the periphery of the rear surface 121 toward the front case 11. The rear case 12 has a shape similar to that of the front surface 111, and in this embodiment, the shape of the rear surface 121 as viewed from the Z direction is substantially rectangular. The rear case 12 is hollow, and the area surrounded by the rear surface 121 and the side surfaces 122 forms a space.

[0025] The front case 11 and the rear case 12 are connected to each other by laser welding. This forms an internal space including a space in the front case 11 and a space in the rear case 12. The sensor board 20 and other components are disposed in this internal space. The welding method is not limited to laser welding and may be, for example, ultrasonic welding.

[0026] 2, the lens barrel 60 is disposed inside the front case 11. The lens barrel 60 has a lens barrel portion 601 made of synthetic resin that fits into the opening 113 in the Z direction via a seal ring O. The lens barrel portion 601 is a cylindrical portion that supports a photographing lens 602, and protrudes from the opening 113 to the front of the front case 11. Although not shown, multiple lenses (photographing lenses 602) are disposed inside the lens barrel portion 601.

[0027] The lens barrel 60 has a substantially rectangular flange portion 603 that protrudes outward from the end of the lens barrel portion 601 on the rear case 12 side. The lens barrel 60 further has a pair of legs 604 that are provided on the flange portion 603 and joined to the sensor substrate 20. As shown in FIG. 2 , the pair of legs 604 are plate-shaped wall portions that extend in the Z direction and face each other in the Y axis direction, and in this embodiment, are provided so as to sandwich the sensor element (image pickup element 22A). The tips of the pair of legs 604 are fixed to the sensor substrate 20 (front substrate 20A) via an adhesive or the like. The lens barrel 60 will be described in detail below.

[0028] The sensor substrate 20 is disposed within the imaging device 100. The sensor substrate 20 includes a front substrate 20A and a rear substrate 20B, which are electrically connected via a B-to-B connection (connector connection) or a flexible connection. The front substrate 20A includes a circuit board 21A and an imaging element 22A (as a sensor element) mounted on the surface of the circuit board 21A facing the lens barrel 601 (see FIG. 2). The sensor substrate 20 further includes a spacer substrate 20C, which is disposed between the front substrate 20A and the rear substrate 20B during this connection by snap-fitting, adhesive bonding, or the like. A solid-state imaging element 22A, such as a CMOS (Complementary Metal-Oxide Semiconductor) or CCD (Charge Coupled Device) image sensor, is mounted on the front substrate 20A as a sensor element. The solid-state imaging element 22A captures subject light through the lens barrel 60. The front substrate 20A and the rear substrate 20B are mounted with peripheral circuits such as a drive circuit for driving the solid-state image sensor 22A and a signal processing circuit for processing an output signal from the solid-state image sensor 22A.

[0029] The circuit board 21A is configured as a double-sided wiring board (a wiring board on which electric circuits are formed on the front and back surfaces) having rigidity, such as a glass epoxy board.

[0030] The image sensor 22A is an image sensor such as a CMOS (Complementary Metal-Oxide Semiconductor) or a CCD (Charge Coupled Device). The image sensor 22A abuts against the lens barrel 601 via the dustproof rubber 30, and has an image pickup surface at a position corresponding to the focal position of the photographing lens 602.

[0031] A connector section 123 is provided on the rear surface section 121 of the rear case 12. The connector section 123 is electrically connected to the sensor board 20 via, for example, an FPC (flexible printed circuit board), and supplies power from the vehicle body side to the sensor board 20 or outputs an image signal from the sensor board 20 to the vehicle body side. The sensor board 20 is not limited to the example in which it is composed of two boards, the front board 20A and the rear board 20B, and may be composed of a single board.

[0032] Between the rear substrate 20B and the rear surface 121 of the rear case 12, there are arranged a heat dissipation sheet 40 for dissipating heat generated by the sensor substrate 20 and a spacer cushion 70 for urging the sensor substrate 20 toward the front case 11 and the lens barrel 60.

[0033] A seal ring O is disposed around the entire periphery inside the front case 11. This seal ring O functions to seal the gap between the front case 11 and the lens barrel 60. This prevents raindrops and the like from entering the inside of the casing through the opening 113 of the front case 11. The seal ring O may be made of any elastic material, such as rubber or plastic.

[0034] The shield case 50 is configured as a substantially rectangular cylinder and has four sides that cover the periphery of the sensor board 20 (front board 20A) including the image sensor 22A. The shield case 50 is typically configured from a metal material such as stainless steel, aluminum alloy, or copper alloy, and is one of the EMC (Electromagnetic Compatibility) countermeasure components that protect the sensor board 20 from electromagnetic noise. The shield case 50 is a press-formed sheet metal made from the above-mentioned metal material. The shield case 50 is disposed inside the front case 11 so as to be sandwiched between the lens barrel 60 and the rear case 12.

[0035] The dustproof rubber 30 is annular and is sandwiched between the lens barrel 60 and the front substrate 20A and arranged around the image sensor 22A. When the front substrate 20A and the lens barrel 60 are joined, the dustproof rubber 30 is sandwiched between the front substrate 20A and the lens barrel 60, thereby stably maintaining the opposing distance between the taking lens 602 and the image sensor 22A. Furthermore, because the dustproof rubber 30 covers the periphery of the image sensor 22A in an annular shape, the dustproof properties of the image sensor 22A can be ensured.

[0036] Fig. 3 is a side cross-sectional view showing the lens barrel 60 of the imaging device 100, Fig. 4 is a rear view showing the lens barrel 60 of the imaging device 100, and Fig. 5 is a diagram showing the application of the covering member 80 to the lens barrel 60 of the imaging device 100. Note that the dustproof rubber 30 is omitted from Fig. 3.

[0037] (Lens barrel) As described above, the lens barrel 60 has the lens barrel portion 601, the photographing lens 602, and the flange portion 603. As shown in Fig. 3, the lens barrel 60 further has a filter mounting portion 605 on which a square infrared cut filter F is mounted in an inner region W (space) surrounded (formed) by the circuit board 21A and the lens barrel 60 (pair of legs 604) when viewed from the X direction.

[0038] Here, the inner region W is a region located inside the flange portion 603 (on the infrared cut filter F side or the image sensor 22A side when viewed from the Z-axis direction), or in other words, a region facing the photographing lens 602 in the Z direction. The infrared cut filter F is a filter that blocks infrared rays that pass through the photographing lens 602 and is provided between the photographing lens 602 and the image sensor 22A, as the sensitivity of the image sensor 22A ranges from the visible region to the infrared region.

[0039] 3 and 4, the filter mounting portions 605 are disposed opposite each other in the Y-axis direction and are each formed in an arc shape. The filter mounting portion 605 has a filter placement portion 607 on which an infrared cut filter F is disposed, and each of the four corners of the infrared cut filter F is disposed. The filter placement portion 607 is recessed toward the photographing lens 602 in the Z-axis direction, which facilitates positioning of the infrared cut filter F when it is disposed.

[0040] The filter mounting portion 605 has a dent 606 that is created when it is pushed out by the ejector pin. Here, a method for manufacturing the lens barrel 60 will be described. Figure 5 is a diagram showing how the coating member 80 is applied to the lens barrel 60 of the imaging device 100.

[0041] In this embodiment, the lens barrel 60 is made of plastic and is manufactured using a molding machine that uses an injection mold. In the molding machine, the lens barrel 60, which is a molded product, is released from the mold by pushing with an ejector pin to release the lens barrel 60 after molding. In this way, the lens barrel 60 is molded.

[0042] As described above, when the lens barrel 60 is released from the mold, it is pushed by the ejector pins, and dents 606, 606' are formed in the areas (filter mounting portion 605, flange portion 603) that are pushed by the ejector pins, so as to be recessed toward the taking lens 602 in the Z-axis direction.

[0043] The dents 606, 606' caused by the ejector pin are roughly circular, with a diameter of approximately 0.8 mm to 1 mm, which is roughly the same as the diameter of the ejector pin. In this embodiment, the depth of the dents 606, 606' in the Z-axis direction is approximately 0.1 mm.

[0044] In this embodiment, as shown in Figures 3 and 4, three dents 606 are provided around the infrared cut filter F in the filter mounting portion 605. Of course, the number of dents 606 is not limited to this and may be two, or four or more. Also, as shown in Figure 4, six dents 606' are provided in the flange portion 603. Of course, the number of dents 606' is not limited to this and may be five or less, or seven or more.

[0045] As shown in Figures 3 and 4, the dent 606 is covered by a covering member 80 when viewed from the Z-axis direction. In this embodiment, the covering member 80 is an ultraviolet curing resin. Since ultraviolet curing resin takes a short time to harden, the time required for the manufacturing process can be shortened. In addition, since it can be irradiated onto a base material that is sensitive to heat, it can harden without deformation. However, the covering member 80 is not limited to this, and a thermosetting resin may also be used.

[0046] In the dent 606 formed in the inner region W (the space formed by the lens barrel 60 and the circuit board 21A), there has been a problem in that a portion of the lens barrel 60 (burrs) easily peels off from the main body of the lens barrel 60 at the recessed portion. In response to this problem, in this embodiment, as shown in FIG. 5 , the recessed dent 606 and an injection device 800 that injects the coating material 80 are aligned in the Z-axis direction, and the coating material 80 is injected into the dent 606. At this time, as shown in FIG. 3 , the coating material 80 is injected (applied) so as to cover the peripheral portion 606A of the dent 606 when viewed from the Z-axis direction. In other words, the coating material 80 is injected into the dent 606 and overflows to cover the peripheral portion 606A. By covering the dent 606 with the coating material 80 as described above, it is possible to prevent a portion of the dent 606 from peeling off from the lens barrel 60. In this way, it is possible to prevent the generation of dust in the inner region W, a space where dust and other foreign matter should be prevented from entering.

[0047] Here, a conventional lens barrel 60' will be described. FIG. 6 is a rear view of the conventional lens barrel 60'. In the conventional lens barrel 60', there are no dents pressed by ejector pins in the inner region W where the filter mounting portion 605' is provided. In the conventional lens barrel 60', there are multiple dents 606'' in the flange portion 603 of the lens barrel 60'. In other words, in the case of the conventional lens barrel 60', when the lens barrel 60' is released from the injection molding die, the flange portion 603 is pressed by an ejector pin to release the lens barrel 60' from the die.

[0048] On the other hand, in this embodiment, the molded lens barrel 60 can be released from the mold by the ejector pin not only at the flange portion 603, but also at a position (filter mounting portion 605) adjacent to the infrared cut filter F and image sensor 22A when viewed from the optical axis position C and the Z-axis direction. As a result, when the lens barrel 60 is released from the mold, it can be pushed out by the ejector pin at a position close to the optical axis position C, which makes it possible to prevent the lens barrel 60 from tipping or warping.

[0049] Furthermore, since it is possible to prevent the lens barrel 60 from tipping or warping as described above, the photographic lens 602 can be accurately assembled into the lens barrel 60. This makes it possible to improve and stabilize lens resolution.

[0050] Furthermore, since it is possible to improve and stabilize lens resolution, it can be used as an in-vehicle camera to output high-definition images for applications such as autonomous driving, rearview monitor recognition, and automatic parking recognition.

[0051] The technology according to the present disclosure can be applied to various products. For example, the technology according to the present disclosure may be realized as an imaging device mounted on any type of moving body, such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, personal mobility, an airplane, a drone, a ship, a robot, construction machinery, or agricultural machinery (tractor).

[0052] In addition, in the above embodiment, a camera module has been described as an example of the imaging device 100, but the present technology is not limited to this. For example, the present technology can also be applied to a sensor module equipped with a distance measurement sensor such as a LIDAR (Light Detection and Ranging) sensor or a TOF (Time of Flight) sensor as a sensor element.

[0053] Furthermore, in the above embodiment, an ultraviolet curable resin has been described as an example of the covering member 80, but this is not limiting. For example, the covering member 80 may be a box-shaped or cylindrical cover member that covers the dent 606 when viewed from the Z-axis direction. In this case, the cover member is fixed to the peripheral portion 606A of the dent 606 with an adhesive. This provides the same effects as the covering member 80, which is an adhesive, described above.

[0054] Furthermore, in the above embodiment, the covering member 80 covers the entire dent 606, but of course this is not limited to this and it may cover only a portion. For example, the peripheral portion 606A of the dent 606 is likely to peel off from the lens barrel 60. In other words, the covering member 80 may be applied along the peripheral portion 606A of the dent 606 so as to cover at least the peripheral portion 606A.

[0055] Furthermore, in the above embodiment, the lens barrel 60 is molded using an injection molding die, but of course this is not limiting, and the lens barrel 60 may also be molded by die casting. Even with die casting, dents may occur and parts of the lens barrel 60 may peel off, so by using a configuration like this embodiment, it is possible to obtain the same effects as this embodiment.

[0056] Furthermore, in the above embodiment, the ejector pins (ejector pins) are round pins, but of course, this is not limitative and square pins may also be used.

[0057] The configurations of the imaging device, front case, rear case, sensor board, etc. described with reference to the drawings are merely one embodiment and can be arbitrarily modified without departing from the spirit of the present technology. In other words, any other configuration for implementing the present technology may be adopted.

[0058] The present technology can also be configured as follows. (1) An imaging device comprising: a circuit board; an imaging element mounted on the circuit board; a lens barrel provided on the circuit board so as to cover the periphery of the imaging element, holding a lens, and having an dent caused by the extrusion of an ejector pin that pushes a molded product out of a mold; and a covering member provided on the lens barrel and covering at least a portion of the dent when viewed from the optical axis direction of the lens. (2) The imaging device described in (1) above, wherein the dent is provided at a position on the lens barrel adjacent to the imaging element when viewed from the optical axis direction. (3) The imaging device described in (1) or (2) above, wherein the lens barrel has a filter mounting section that mounts an infrared cut filter, and the dent is provided on the filter mounting section around the infrared cut filter when viewed from the optical axis direction. (4) The imaging device described in any one of (1) to (3) above, wherein the covering member covers a peripheral portion of the dent. (5) The imaging device according to any one of (1) to (4) above, wherein the covering member is an adhesive. (6) The imaging device according to (5) above, wherein the adhesive is provided inside the dent portion and on the periphery of the dent portion. (7) The imaging device according to any one of (1) to (6) above, wherein the lens barrel is formed by die-casting or injection molding. (8) The imaging device according to any one of (1) to (7) above, wherein the dent portion is provided in a space formed by the lens barrel and the circuit board. (9) The imaging device according to any one of (1) to (8) above, wherein the adhesive is an ultraviolet-curing resin.

[0059] REFERENCE SIGNS LIST 10 housing 11 front case 12 rear case 20 sensor board 22A imaging element 60 lens barrel 80 covering member 100 imaging device 601 lens barrel portion 602 taking lens 603 flange portion 605 filter mounting portion 606 dent portion F infrared cut filter W inner region

Claims

1. An imaging device comprising: a circuit board; an imaging element mounted on said circuit board; a lens barrel attached to said circuit board so as to cover the periphery of said imaging element, said lens barrel having an indentation caused by the extrusion of an ejector pin that pushes a molded product out of a mold; and a covering member attached to said lens barrel that covers at least a portion of said indentation when viewed from the direction of the optical axis of said lens.

2. An imaging device according to claim 1, wherein the dent is provided at a position on the lens barrel adjacent to the imaging element when viewed in the optical axis direction.

3. An imaging device according to claim 1, wherein the lens barrel has a filter mounting section that mounts an infrared cut filter, and the dent is provided on the filter mounting section around the infrared cut filter when viewed from the optical axis direction.

4. An imaging device according to claim 1, wherein the covering member covers the periphery of the dent.

5. An imaging device according to claim 1, wherein the covering member is an adhesive.

6. An imaging device according to claim 5, wherein the adhesive is provided inside the dent and on the periphery of the dent.

7. An imaging device according to claim 1, wherein the lens barrel is formed by die casting or injection molding.

8. An imaging device according to claim 1, wherein the dent portion is provided within a space formed by the lens barrel and the circuit board.

9. An imaging device according to claim 1, wherein the adhesive is an ultraviolet curing resin.

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