In-vehicle camera device

Abstract

To provide an on-vehicle camera device that has a substrate and an optical system adhered with high strength and with high accuracy.SOLUTION: An on-vehicle camera device of the present invention is the on-vehicle camera device that comprises: a camera module; and a housing having the camera module attached. The camera module has: a lens barrel that includes a plurality of optical lenses; a substrate that has an imaging element anchored; and an adhesive that anchors the lens barrel and substrate. The lens barrel has, when viewing a cross section: a bottom face part that is parallel with the substrate; and a lateral face side that surrounds the imaging element. The lateral face part has a tapering part formed so that a wall of the lens barrel tapers toward an outer side of the lens barrel from the bottom face part. The taper part has a surface structure that is obtained by a surface activation treatment.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an in-vehicle camera device. [Background technology]

[0002] Background art in this technical field is Patent Document 1. Patent Document 1 describes "an adhesive structure comprising a first member, a second member having a support part including an opposing surface facing the first member and a side surface inclined outward when viewed from the first member side, and an adhesive interposed between the first member and the support part, extending from the opposing surface to the side surface, having a fillet shape at an end on the side surface side, and fixing the first member to the second member." [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-5104 Summary of the Invention [Problem to be solved by the invention]

[0004] The aforementioned Patent Document 1 describes a structure that improves fracture strength when an imaging device mounted on a circuit board is fixed to an imaging optical system, such as a lens, using an adhesive. The configuration described in Patent Document 1 includes a tapered portion that slopes outward on the side of the support portion of the lens case that holds the lens, a liquid reservoir connected to the tapered portion, and adhesive filling the tapered portion and the liquid reservoir to form a fillet for bonding. However, while this configuration effectively improves strength by forming a large fillet at the adhesive joint, it also causes significant cure shrinkage of the adhesive, making it more likely to cause optical axis misalignment or pin misalignment during fixation. Therefore, in an in-vehicle camera that requires high-strength and high-precision fixation of the lens and imaging device, there is a risk of reduced three-dimensional detection accuracy.

[0005] In view of the above circumstances, an object of the present invention is to provide an in-vehicle camera device in which a substrate and an optical system are bonded with high strength and high precision. [Means for solving the problem]

[0006] In order to achieve the above object, the vehicle-mounted camera device of the present invention comprises: An in-vehicle camera device comprising a camera module and a housing to which the camera module is attached, the camera module comprising a lens barrel including a plurality of optical lenses, a substrate to which an imaging element is fixed, and an adhesive for fixing the lens barrel and the substrate. Preparation When viewed in cross section, the lens barrel has a bottom surface parallel to the substrate, a side surface surrounding the image sensor, and consists of , the side part is When the surface on the imaging element side is the inner surface and the surface on the outside side is the outer surface, From the bottom of the telescope tube Outer surface The wall of the lens barrel is tapered to become thicker toward the Department tapered portion The surface of Surface activation treatment The adhesive applied to the substrate spreads from the bottom surface to the tapered portion to fix the substrate and the lens barrel together, and a step portion that connects to the tapered portion is provided at the end of the outer circumferential surface of the lens barrel at the tapered portion. It is characterized by:

[0007] More specific configurations of the present invention are set forth in the claims. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an in-vehicle camera device in which a substrate and an optical system are bonded with high strength and high precision.

[0009] Problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view of a camera module included in an in-vehicle camera device according to a first embodiment of the present invention; [Figure 2] 1A and 1B are cross-sectional views ((a) plasma irradiation to the lens barrel, (b) bonding the substrate and lens barrel) illustrating a manufacturing process of a camera module compared with Example 1 of the present invention. [Figure 3]1A to 1C are cross-sectional views schematically illustrating a manufacturing process of a camera module according to a first embodiment of the present invention ((a) plasma irradiation to a lens barrel, (b) bonding a substrate and a lens barrel together). [Figure 4] FIG. 6 is a cross-sectional view of a camera module constituting an in-vehicle camera device according to a second embodiment of the present invention. [Figure 5] FIG. 10 is a schematic perspective view of a camera module constituting an in-vehicle camera device according to a third embodiment of the present invention. [Figure 6] FIG. 10 is a schematic perspective view of a camera module constituting an in-vehicle camera device according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. [Example]

[0012] 1 is a cross-sectional view of a camera module constituting an in-vehicle camera device of Example 1. In-vehicle camera device 1a of Example 1 includes a camera module 2a and a housing 3 that houses camera module 2a. Camera module 2a includes a substrate 7 and a lens barrel 5 fixed to substrate 7 using adhesive 8. An imaging element 6 is mounted on substrate 7, and adhesive 8 is applied to the substrate 7 around imaging element 6.

[0013] Furthermore, optical lens 4 is fixed integrally to lens barrel 5, and optical lens 4 and lens barrel 5 form an optical system. Although only one optical lens is shown in Fig. 1, it is also possible to mount multiple optical lenses.

[0014] With the above configuration 、 The optical lens 4 forms an image of visual information obtained from the outside world onto the image sensor 6. the law of nature, In-vehicle camera device 1a obtains an image of the outside world.

[0015] Next, the structure of the lens barrel 5 will be described in detail. When viewed in cross section, the lens barrel 5 has a bottom surface 9 that is substantially parallel to the substrate 7, and a side surface 10 that surrounds the image sensor 6. and, It has. The side surface 10 of the lens barrel 5 is 6 When the surface facing the lens barrel 5 is defined as an inner peripheral surface 11 and the surface facing the outside is defined as an outer peripheral surface 12, the lens barrel 5 has a tapered portion 13 formed so that the wall of the lens barrel 5 becomes thicker from the bottom portion 9 toward the outer peripheral surface 12.

[0016] The surface of the tapered portion 13 has been subjected to a surface activation treatment, and the adhesive 8 applied to the substrate 7 spreads from the bottom surface 9 to the tapered portion 13, thereby fixing the substrate 7 and the lens barrel 5 together. Example In the example, the surface of substrate 7 on which adhesive 8 is provided faces tapered portion 13 of lens barrel 5, and tapered portion 13 serves as the main adhesive surface with substrate 7.

[0017] The adhesive 8 can be a photo-curable adhesive containing a photo-curing agent that is activated by irradiation with light energy such as UV and undergoes a curing reaction, or a thermo-curable adhesive containing a thermo-curing agent that is activated by heating and undergoes a curing reaction, with a photo- and thermo-combined adhesive that contains both a photo-curing agent and a thermo-curing agent being the most suitable.

[0018] Adhesive 8 is attached to the camera module 2 a During manufacturing, the lens barrel 5 is applied in a liquid state onto the substrate 7, and the lens barrel 5 and the substrate 7 are fixed in a state where the fixed positions of the lens barrel 5 and the substrate 7 are determined. At this time, the lens barrel 5 and the substrate 7 are fixed in a state where the optical axis of the optical lens 4 integrated with the lens barrel 5 is approximately perpendicular to the imaging surface of the imaging element 6, and the focal point of the optical lens 4 is aligned with the imaging element 6. 6 It is fixed at a position roughly corresponding to the

[0019] next 、 The plasma irradiation process will be described with reference to Fig. 2 and Fig. 3. Fig. 2 and Fig. 3 are cross-sectional schematic diagrams showing the manufacturing process of a camera module ((a) lens barrel). 5 (b) Plasma irradiation on the substrate 7 and the telescope 5FIG. 2 shows a camera module having a lens barrel (without a tapered portion) to be compared with Example 1, and FIG. 3 shows the camera module of Example 1. 2a is.

[0020] As shown in FIG. 2, in the configuration without the tapered portion 13, 7 and the telescope 5 As shown in the structure after adhesive fixation (b), the adhesive 8 is fixed to the bottom surface 9 of the lens barrel 5, and some adhesive 8 The adhesive forms the fillet portion 20 and is fixed together with the side portion 10. 8 The greater the amount of fillet 20, the greater the area of ​​fixation with the side surface portion 10, resulting in higher strength, but the greater the cure shrinkage of the fillet portion 20. In an in-vehicle camera device that requires high precision, the fillet portion 20 should be made smaller to reduce cure shrinkage, that is, 、 glue 8 It is preferable to reduce the amount used.

[0021] glue 8 If the adhesive 8 The adhesive hardly spreads onto the side surface 10, and the bottom surface 9 becomes the adhesive surface mainly, and the lens barrel 5 is fixed to the substrate 7. In this case, however, a decrease in strength becomes an issue. Therefore, by performing a surface activation process on the adhesive surface (bottom surface 9 in the case of Figure 2) and adding fine irregularities and hydrophilic functional groups to the surface, it is possible to improve the bonding strength between the lens barrel 5 and the adhesive 8, thereby increasing the strength.

[0022] However, in order to obtain the effect of the plasma treatment, it is necessary to perform plasma irradiation immediately before bonding the substrate 7 and the lens barrel 5. 13 In the configuration of FIG. 2, where there is no plasma 18, it is necessary to irradiate the bottom surface 9, which is the adhesive surface, with the 5 This results in irradiation from below, which may affect the optical lens 4 fixed to the lens barrel 5.

[0023] Book Example In this configuration, as shown in Figure 3, of 5 The tapered portion 13 formed on the outer peripheral surface 12 is the main adhesive surface, so that the plasma from the side of the lens barrel 5 18This allows irradiation and plasma processing without affecting the optical lens 4.

[0024] Examples of surface activation treatment methods for the tapered portion 13 include UV ozone treatment, corona discharge treatment, and plasma treatment. The effectiveness of plasma treatment varies depending on the type of treatment gas, and when an epoxy adhesive is used, nitrogen plasma treatment using nitrogen gas is most preferable.

[0025] next 、 Book Example Due to the composition of 8 in optics lens 4 and image sensor 6 High strength 、 and 、 The mechanism that enables high-precision fixation and the verification results will be explained.

[0026] In this embodiment In-vehicle camera device 1a Now, optical lenses 4 The optical axis of the image sensor 6 perpendicular to the imaging plane of the optical lens 4 The focal position of the image sensor 6 The optical lens is designed to match the imaging surface of the 4 and image sensor 6 The positional relationship is ideal.

[0027] Therefore, in order to achieve the above positional relationship, In this embodiment In-vehicle camera device 1a teeth 、 At the time of manufacturing Light Academic Lens 4 and image sensor 6 The positional relationship of the adhesive agent and the adhesive agent that were in a liquid state at the adjusted position were adjusted. 8 Solidify Rua The desired optical performance is achieved by using an active alignment process. 8 By completely solidifying the material, it can be made strong enough for practical use. can .

[0028] However, adhesive8 When the adhesive hardens, it may shrink and cause misalignment. 8 The amount of coating is large, and the fillet area 20 This is likely to occur when large particles are formed. Therefore, high precision is required. In this embodiment In-vehicle camera device 1a So, filleting is used to reduce hardening shrinkage. Part 20 Smaller, that is, 、 glue 8 It is preferable to reduce the amount used.

[0029] glue 8 If the amount of use is reduced, in order to improve the adhesive strength, Example Like, the telescope tube 5 Outer surface of 12 A tapered portion 13 is formed in the tapered portion of 13 It is effective to perform a surface activation treatment on the surface and use this tapered portion 13 as the main adhesive surface with the substrate 7.

[0030] In the adhesive structure described in Patent Document 1, a tapered portion is formed on the second member, but the tapered portion of the second member does not face the surface of the first member on which the adhesive body is provided, and the tapered portion does not form a main adhesive surface with the first member. In addition, the tapered portion is not surface-activated, and if the amount of adhesive is insufficient, the adhesive does not wet and spread across the tapered portion, resulting in poor strength.

[0031] On the other hand, Example The composition of , the tapered portion 13 Surface activation treatment ensures adhesive 8 is the tapered part 13 As a result of the inventor's experiments, it was found that the tapered portion 13 When surface activation treatment was performed, the strength was improved by about 2 times compared to the camera module without surface activation treatment, and the fracture mode was similar to that of the lens barrel. 5 It is known that the fracture has changed to fracture of the base material. In other words, it is thought that the improved adhesive strength has eliminated fracture due to hardening shrinkage of the adhesive 8.

[0032] End This embodiment described The composition of the adhesive of 8 By reducing the amount of adhesive, the positional accuracy between the substrate 7 and the lens barrel 5 can be improved while still ensuring sufficient adhesive strength, enabling the camera module to have high accuracy and strength. 8 This allows for a reduction in the amount of adhesive used during manufacturing. of 8 Cost reduction is also possible. [Example]

[0033] The present invention The second embodiment will be described with reference to FIG. 、 The matters described in the first embodiment but not described in the present embodiment are also applicable to the present embodiment unless there are special circumstances. 1b Camera module that configures 2b 1 is a cross-sectional view of the present embodiment. In-vehicle camera device 1b In teeth , a step 14 is provided between the end of the outer peripheral surface 12 side of the lens barrel 5 and the tapered portion 13. In a structure in which the tapered portion 13 is formed on the outer peripheral surface 12 of the lens barrel 5, if a surface activation treatment is performed on the tapered portion 13, the wettability of the adhesive 8 is improved, and the adhesive 8 wets and spreads over the tapered portion 13, making it possible to firmly fix the lens barrel 5 and the substrate 7. Here, if the wet spread of the adhesive 8 is large and the adhesive 8 spreads over the tapered portion 13 onto the outer peripheral surface 12 of the lens barrel 5, the balance of the curing contraction forces becomes poor, and the optical axis of The deviation may be large.

[0034] Therefore, according to the configuration of this embodiment, by providing step portion 14 at the end of tapered portion 13 on the outer circumferential surface 12 side of barrel 5, the spreading of adhesive 8 can be stopped by step portion 14, and the amount of spreading can be controlled. By controlling the amount of spreading, even if there is unevenness in the application of adhesive 8, for example, the spreading height becomes constant, and deviation of the optical system during cure shrinkage can be suppressed. [Example]

[0035] The present invention The third embodiment will be described with reference to FIG.、 The matters described in the first or second embodiment but not described in the present embodiment are also applicable to the present embodiment unless there are special circumstances. 2c In this embodiment, the vehicle-mounted camera device 1c includes a camera module 2c and a housing 3. Although not shown, the camera module 2c includes an optical lens, as in the first embodiment. 4 The telescope tube that holds 5 , an imaging element provided on the substrate 7 6 and the substrate 7 and the lens barrel 5 adhesive to fix 8 It has.

[0036] Here, when the direction perpendicular to the direction of the optical axis 19 of the camera module 2c is defined as the normal direction, the tapered portion 13 formed on the outer peripheral surface of the lens barrel of the camera module 2c is of 5 Outer surface 12 Among these, the conductors are arranged approximately parallel to the perpendicular direction. Approximately parallel to the perpendicular direction It is formed on the surface 15, the surface of which has been subjected to a surface activation treatment.

[0037] One method for calculating the distance to a subject based on an image obtained from a single camera module is to use the imaging height and camera height. This method uses height information to calculate the distance to the subject, so in order to improve distance measurement performance, it is important to prevent optical axis misalignment, particularly in the perpendicular direction. According to the configuration of this embodiment, optical axis misalignment in the perpendicular direction is less likely to occur, thereby suppressing a decrease in distance measurement accuracy due to optical axis misalignment. [Example]

[0038] The present invention The fourth embodiment will be described with reference to FIG. 、 The matters described in the first to third embodiments but not described in this embodiment are also applicable to this embodiment unless there are special circumstances. 1d Camera module that configures 2In this embodiment, the vehicle-mounted camera device 1d has a second camera module 16 having the same structure as the camera module (first camera module) 2, and the second camera module 16 is composed of a second lens barrel that holds a second optical lens (not shown), a second substrate 7 that has a second imaging element mounted thereon, and a second adhesive that fixes the second lens barrel and the second substrate 7 together.

[0039] The camera module 2 and the second camera module 16 are attached to the housing 3 with their optical axes 19 approximately parallel to each other, and the vehicle-mounted camera device 1d measures the distance to the subject by comparing the image information acquired by the camera module 2 and the second camera module 16.

[0040] Here, if the direction in which the camera module 2 and the second camera module 16 are aligned is defined as the base length direction, the lens barrels of the camera module 2 and the second camera module 16 are and the second telescope Outer surface of and a second outer peripheral surface The tapered portion 13 formed in and the second tapered portion 13 is the outer surface and a second outer peripheral surface In this case, the slits are arranged along a direction substantially parallel to the base line length direction. Approximately parallel to the baseline direction Face 17 and a surface 17 substantially parallel to the second base length direction. The surface is subjected to a surface activation treatment.

[0041] Parallax matching is a commonly used method for calculating the distance to a subject based on images obtained from two camera modules. This is a distance measurement method based on the principle of triangulation, in which the parallax in the baseline length direction of the two images is inversely proportional to the distance to the subject.

[0042] In this method, the distance from the subject of several tens of meters is converted into a parallax of several micrometers and detected, so in order to improve distance measurement accuracy, it is important to prevent optical axis misalignment, particularly in the baseline length direction. According to the configuration of this embodiment, optical axis misalignment in the baseline length direction is unlikely to occur, so that a decrease in distance measurement accuracy due to optical axis misalignment can be suppressed.

[0043] As explained above, this Example According to the method, the substrate 7 and the optical system are connected with high strength. 、 and 、 It has been shown that it is possible to provide an in-vehicle camera device that can be bonded with high precision.

[0044] The present invention is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with other configurations. [Explanation of symbols]

[0045] 1a, 1b , 1c, 1d ...In-vehicle camera device, 2、 2a, 2b, 2 c… Camera module, 3... housing, 4... optical lens, 5... lens barrel, 6... imaging element, 7... substrate, a second substrate; 8...adhesive, 9...bottom surface of the lens barrel, 10...side surface of the lens barrel, 11...inner peripheral surface of the lens barrel, 12...outer peripheral surface of the lens barrel, 13...tapered portion, a second tapered portion; 14...step portion, 15...surface substantially parallel to the perpendicular direction, 16...second camera module, 17...surface substantially parallel to the base length direction, a surface substantially parallel to the second base line length direction, 18...plasma, 19...optical axis of the camera module, optical axis of the second camera module, 20...Adhesive fillet area.

Claims

1. An in-vehicle camera device comprising a camera module and a housing to which the camera module is attached, the camera module includes a lens barrel including a plurality of optical lenses, a substrate to which an imaging element is fixed, and an adhesive that fixes the lens barrel and the substrate; the lens barrel, when viewed in cross section, comprises a bottom surface portion parallel to the substrate and a side surface portion surrounding the image sensor, and the side surface portion has a tapered portion formed such that the wall of the lens barrel becomes thicker from the bottom surface portion toward the outer peripheral surface of the lens barrel, when the surface on the image sensor side is the inner peripheral surface and the surface on the outside side is the outer peripheral surface, a surface of the tapered portion is subjected to a surface activation treatment, and the adhesive applied to the substrate spreads from the bottom surface portion to the tapered portion, thereby fixing the substrate and the lens barrel together; The vehicle-mounted camera device is characterized in that a step portion that is continuous with the tapered portion is provided at an end of the outer peripheral surface of the lens barrel of the tapered portion.

2. The vehicle-mounted camera device according to claim 1, The vehicle-mounted camera device is characterized in that the adhesive contains a light curing agent and a heat curing agent.

3. The vehicle-mounted camera device according to claim 1, The vehicle-mounted camera device is characterized in that the adhesive is an epoxy adhesive composition, and the surface activation treatment is a nitrogen plasma treatment.

4. The vehicle-mounted camera device according to claim 1, The vehicle-mounted camera device is a monocular camera, and the tapered portion is formed on a pair of surfaces around the periphery of the lens barrel that are approximately parallel to a perpendicular line perpendicular to the optical axis of the monocular camera.

5. The vehicle-mounted camera device according to claim 1, the in-vehicle camera device is a stereo camera, and includes a first camera module and a second camera module as the camera modules; the first camera module and the second camera module are fixed to the housing so that their optical axes are substantially parallel to each other; When the direction in which the first camera module and the second camera module are aligned is defined as a baseline length direction, the tapered portion is arranged on the outer surface of the lens barrel so as to be approximately parallel to the baseline length direction.

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