In-vehicle camera

Abstract

To provide an imaging apparatus which can reduce dew condensation of a lens.SOLUTION: An imaging apparatus according to an aspect of the embodiment comprises a lens barrel, a substrate, a housing and a first heat radiation member. The lens barrel stores a lens. The substrate is mounted with a sensor which converts light received via the lens into an image signal. The housing stores the lens barrel and the substrate. The first heat radiation member is provided between the lens barrel and the housing and thermally connects the lens barrel and the housing.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to In-vehicle camera .

Background Art

[0002] In recent years, with the spread of vehicle driving support systems, cameras are increasingly being mounted on vehicles. In addition, since clearer images are required for the images captured by the cameras mounted on vehicles (hereinafter also referred to as in-vehicle cameras), the number of pixels of the image sensors (hereinafter simply referred to as sensors) provided in in-vehicle cameras has a tendency to increase.

[0003] By the way, as the number of pixels increases, the amount of heat radiation from the sensor increases, so the temperature of the in-vehicle camera tends to rise. When the internal temperature of the in-vehicle camera rises, the temperature difference between the internal temperature of the in-vehicle camera and the outside air becomes larger, so there is a possibility of condensation occurring on the lens exposed to the outside. Conventionally, efforts have been made to prevent condensation by increasing airtightness with the outside air, such as providing an O-ring in the gap between the lens and the lens barrel or sealing it with an adhesive (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the above-described conventional technology, although airtightness with respect to the outside air can be increased, a temperature difference may occur between the inside of the lens barrel and the sensor inside the in-vehicle camera, and condensation may occur.

[0006] The problem to be solved by the present disclosure is to provide In-vehicle camera that can reduce condensation on the lens.

Means for Solving the Problems

[0007] One aspect according to the present embodiment In-vehicle camera includes a lens barrel, a sensor, a substrate, a housing, and a first heat dissipation member. The lens barrel which is cylindrical, accommodates lenses. The sensor converts the light received through the lens into an image signal. The substrate has a first surface and a second surface opposite to the first surface, and the sensor is disposed on the first surface. The housing has an inner peripheral side surface and an outer peripheral side surface, The lens barrel the sensor and the substrate. The first heat dissipation member thermally connects the lens barrel the outer peripheral surface of, and the inner peripheral side surface of the housing to is disposed, the lens barrel and the housing. also, the first heat dissipation member is sheet-shaped, wound around the outer peripheral surface of the lens barrel, and in contact with the outer peripheral surface of the lens barrel and the inner peripheral side surface of the housing.

Advantages of the Invention

[0008] According to the present disclosure, condensation on the lens can be reduced.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings as appropriate. However, a more detailed description may be omitted as necessary. Note that the accompanying drawings and the following description are provided for those skilled in the art to fully understand the present disclosure, and it is not intended to limit the subject matter described in the claims.

[0011] (First Embodiment) The imaging device according to the first embodiment is, for example, an in-vehicle camera mounted on a vehicle and can be used for vehicle driving assistance. The imaging device for driving assistance plays a major role in the vehicle driving assistance system by detecting objects such as vehicles, pedestrians, and obstacles through image processing by an internal ISP (Image Signal Processor), and giving warnings to the driver or forcibly stopping the vehicle.

[0012] FIG. 1 is an external view of the imaging device 100 according to the first embodiment. FIG. 2 is a longitudinal sectional view of the imaging device 100 according to the first embodiment.

[0013] In the drawings described below, for convenience, the X-axis and Z-axis orthogonal to each other are shown, and the vertical direction (X direction) and the left-right direction (Z direction) in the imaging device 100 of the embodiment are described using the X-axis and Z-axis. In the following description, when simply described as the X direction or the Z direction, they are the respective axial directions and include two opposite directions.

[0014] Also, when specified as the positive direction of the X-axis, it is a single direction from the lower side to the upper side, and when specified as the positive direction of the Z-axis, it is a single direction from the left side to the right side. When specified as the negative direction of the X-axis, it is a single direction from the upper side to the lower side, and when specified as the negative direction of the Z-axis, it is a single direction from the right side to the left side.

[0015] The imaging device 100 according to the first embodiment includes a first housing 10, a second housing 20, a lens barrel 30, a lens 40, an IR (Infrared Rays) cut filter 46, a substrate 50, a first fixing member 54, a second fixing member 55, and a sensor 56.

[0016] The first housing 10 and the second housing 20 are made of a conductive material such as metal. The first housing 10 and the second housing 20 are made of, for example, aluminum die-casting (as an example, an aluminum alloy such as ADC12), etc. The first housing 10 and the second housing 20 house a part of the lens barrel 30 and the substrate 50 inside the space formed by combining the first housing 10 and the second housing 20.

[0017] The lens barrel 30 is a cylindrical member with both ends open. The lens barrel 30 is formed of, for example, a member having moisture absorption such as resin. A part of the lens barrel 30 is housed in a concave portion 31 provided in the first housing 10. More specifically, the lens barrel 30 is housed in the concave portion 31 of the first housing 10 with the tip portion (the first lens 41 side) of the lens barrel 30 exposed. Note that the concave portion 31 of the lens barrel 30 has a shape corresponding to the diameter of the lens barrel 30.

[0018] Also, inside the lens barrel 30, the lens 40 and the IR cut filter 46 are arranged at predetermined positions. Specifically, the lens barrel 30 arranges the first lens 41, the second lens 42, the third lens 43, the fourth lens 44, the fifth lens 45, and the IR cut filter 46, which will be described later, in the order in which they enter the lens barrel 30.

[0019] The lens 40 has the first lens 41, the second lens 42, the third lens 43, the fourth lens 44, and the fifth lens 45. The lens 40 is formed of plastic or glass, etc. Also, air is held between the lenses of the lens 40 housed in the lens barrel 30. Note that the number of lenses of the lens 40 is not limited to this.

[0020] The IR cut filter 46 cuts the infrared rays incident from the lens 40 and transmits only visible light to a sensor 56, which will be described later. Note that the configuration of the lens barrel 30 and the lens 40 and the IR cut filter 46 arranged inside the lens barrel 30 is also collectively referred to as a lens unit.

[0021] The substrate 50 is housed inside the space formed by the first housing 10 and the second housing 20. The substrate 50 has a first substrate 51, a second substrate 52, and a flexible wiring 53, which will be described later. The substrate 50 mounts a sensor 56, which will be described later, for imaging the subject image formed on the imaging surface by the lens 40.

[0022] The first substrate 51 is the substrate 50 on which the sensor 56, which will be described later, is mounted. The first substrate 51 is the substrate 50 fixed to the first housing 10 via a first fixing member 54 and a second fixing member 55. The second substrate 52 has a mounting board connector for fitting an output mechanism (not shown) and is the substrate 50 electrically connected to the first substrate 51 via the flexible wiring 53. The flexible wiring 53 is a wiring for electrically connecting the first substrate 51 and the second substrate 52.

[0023] The first fixing member 54 and the second fixing member 55 are, for example, screws made of a metal material (as an example, stainless steel) or the like, and fix the first substrate 51 to the first housing 10. Specifically, the first fixing member 54 and the second fixing member 55 are inserted into holes provided in the first substrate 51 from the first housing 10 to fix the first substrate 51 to the first housing 10.

[0024] The method of fixing the first substrate 51 is not particularly limited. For example, it may be fixed using an adhesive. When using an adhesive, for example, a UV semi-curing adhesive is applied (filled) to a first tray 541 in contact with the first fixing member 54 provided on the first substrate 51 and a second tray 542 in contact with the second fixing member 55. Then, after adjusting the arrangement position and arrangement angle of the first substrate 51 with respect to the lens barrel 30, the adhesive is cured.

[0025] The sensor 56 is mounted on the first substrate 51. The sensor 56 is an imaging device, for example, a CMOS (Complementary Metal Oxide Semiconductor) type image sensor. The sensor 56 receives the light that has passed through the lens 40 and the IR cut filter 46 in the lens barrel 30, forms an image of the received light, and converts it into an image signal. The sensor 56 is arranged on the optical axis of the lens barrel 30 and the lens 40. Also, the sensor 56 generates heat when it operates. That is, the sensor 56 is a heat generation source that generates heat.

[0026] The sealing member 60 is provided between the lens barrel 30 and the first lens 41. The sealing member 60 is, for example, an O-ring. The imaging device 100 realizes a waterproof function by providing the sealing member 60.

[0027] The sealant 61 is provided between the first lens 41 and the second lens 42. The sealant 61 is, for example, a resin such as an adhesive, and more preferably an ultraviolet curable resin or the like is used. Since the sealant 61 and the second lens 42 form a sealing structure, the inflow of fluid from the second lens 42 side to the first lens 41 side (-Z-axis direction) can be blocked.

[0028] Also, the sealant 61 is provided between the fifth lens 45 and the IR cut filter 46. Since the sealant 61 and the IR cut filter 46 form a sealing structure, the inflow of fluid from the IR cut filter 46 side to the fifth lens 45 side (-Z-axis direction) can be blocked. The fluid is, for example, hot and humid air. Note that the sealing structure may be a heat insulation structure.

[0029] Incidentally, in the above configuration, when the imaging device 100 operates, the sensor 56 generates heat. When the sensor 56 generates heat, the temperature inside the first housing 10 rises. When the temperature inside the first housing 10 rises, the temperature difference between the temperature inside the first housing 10 and the outside air becomes larger, so dew condensation may occur on the lens 40 exposed to the outside. Although the above-described sealing member 60 and sealant 61 can enhance the airtightness of the imaging device 100 against the outside air, they cannot block the heat inside the first housing 10, and there is room for further improvement.

[0030] Therefore, in the imaging device 100 of the first embodiment, in order to reduce dew condensation on the lens 40 due to the temperature difference between the above-described first housing 10 and the lens barrel 30, the following configuration is provided.

[0031] The imaging device 100 of the first embodiment includes a first heat dissipation member 71. The first heat dissipation member 71 is formed of a member having thermal conductivity (for example, a heat dissipation sheet, heat dissipation grease, etc.).

[0032] The first heat dissipation member 71 is provided between the first housing 10 and the lens barrel 30. Specifically, the first heat dissipation member 71 is provided between the concave portion 31 of the first housing 10 and the outer peripheral surface of the lens barrel 30, and thermally connects the first housing 10 and the lens barrel 30. For example, the first heat dissipation member 71 is provided (wrapped) along the outer peripheral surface of the lens barrel 30. By providing the first heat dissipation member 71 between the first housing 10 and the lens barrel 30, the heat from the inside of the first housing 10 is conducted to the outer peripheral surface of the lens barrel 30 via the first heat dissipation member 71. By the conduction of heat, the temperature difference between the inside of the first housing 10 and the inside of the lens barrel 30 is less likely to occur.

[0033] Thereby, the first heat dissipation member 71 can make the temperature difference between the inside of the first housing 10 and the inside of the lens barrel 30 small and substantially uniform. Therefore, the imaging device 100 can reduce dew condensation on each lens 40 housed in the lens barrel 30. The first heat dissipation member 71 may be provided on the bottom surface of the concave portion 31 of the first housing 10.

[0034] In addition, the imaging device 100 of the first embodiment further includes a second heat dissipation member 72. The second heat dissipation member 72 is provided between the first substrate 51 and the second substrate 52. Specifically, the second heat dissipation member 72 is provided between the back surface side of the substrate surface of the first substrate 51 on which the sensor 56 is mounted and the back surface side of the mounting substrate connector that fits the output mechanism of the second substrate 52, and thermally connects the first substrate 51 and the second substrate 52.

[0035] Further, the second heat dissipation member 72 is in contact with the side surface of the first housing 10. Specifically, the second heat dissipation member 72 is in contact with the inner peripheral side surface and the inner peripheral bottom surface of the first housing 10 inside the space formed by the first housing 10 and the second housing 20 in which the substrate 50 (the first substrate 51 and the second substrate 52) is accommodated, and thermally connects the first housing 10 and the substrate 50.

[0036] The second heat dissipation member 72 is formed of a member having thermal conductivity (for example, heat dissipation grease, heat dissipation silicon, etc.). For example, when the second heat dissipation member 72 is a two-component mixed type heat dissipation grease, after mixing the two components, it becomes a highly viscous liquid during the pot life, so it can cope with various shapes such as the slight gaps between the electronic components mounted on the substrate 50. The first heat dissipation member 71 and the second heat dissipation member 72 are collectively referred to as the heat dissipation member 70.

[0037] Here, a method of providing the second heat dissipation member 72 on the first substrate 51 and the second substrate 52 will be described with reference to FIG. 3. FIG. 3 is a diagram showing an example of a schematic view of the inside of the imaging device 100 according to the first embodiment during assembly. In this example, a case where a two-component mixed type heat dissipation grease is used as the second heat dissipation member 72 will be described.

[0038] First, the heat dissipation grease is applied to the center of the opposite side (hereinafter also referred to as the back surface) of the substrate surface of the first substrate 51 on which the sensor 56 is mounted. Thereafter, the second substrate 52 is pressed from above so as to sandwich the heat dissipation grease applied to the back surface of the first substrate 51 between the second substrate 52 and the first substrate 51, thereby bringing the first substrate 51 and the second substrate 52 into close contact.

[0039] The heat-dissipating grease flows into the gap between the first substrate 51 and the second substrate 52 when the second substrate 52 is pressed from above, and reaches the wall surfaces (inner peripheral side surface and inner peripheral bottom surface) of the first housing 10 that have flowed out of the gap. Then, when the heat-dissipating grease naturally cures, the thermal connection between the first substrate 51 and the first housing 10 is maintained by the heat-dissipating grease (heat-dissipating member 70).

[0040] The second heat-dissipating member 72 contacts the side surface of the first housing 10, so that the heat from the sensor 56 is conducted to the side surface of the first housing 10 through the second heat-dissipating member 72. When heat is conducted, the temperature difference between the inside of the first housing 10 and the sensor 56 is less likely to occur. Thereby, the second heat-dissipating member 72 can make the temperatures of the inside of the first housing 10 and the sensor 56 uniform.

[0041] Thus, in the imaging device 100 of the first embodiment, by providing the heat-dissipating member 70 between the first housing 10 and the lens barrel 30, the heat from the first housing 10 is conducted to the lens barrel 30. Thereby, in the imaging device 100 of the first embodiment, since the temperature difference between the inside of the first housing 10 and the inside of the lens barrel 30 can be eliminated, fogging of the lens 40 can be reduced. Therefore, the imaging device 100 of the first embodiment can reduce the occurrence of dew condensation on the lens 40.

[0042] Also, in the imaging device 100 of the first embodiment, by providing the heat-dissipating member 70 between the first substrate 51 and the second substrate 52, the heat generated by the sensor 56 is conducted to the first housing 10. Thereby, in the imaging device 100 of the first embodiment, since the temperature difference between the first housing 10 and the sensor 56 can be reduced, the temperature difference between the inside of the first housing 10 and the inside of the lens barrel 30 can be reduced.

[0043] (Second Embodiment) Next, a second embodiment will be described. FIG. 4 is an external view of the imaging device 200 according to the second embodiment. FIG. 5 is a longitudinal sectional view of the imaging device 200 according to the second embodiment. Descriptions of parts common to the above-described first embodiment will be omitted as appropriate. Note that the same reference numerals are given to components similar to those in the first embodiment, and the descriptions thereof will be omitted as appropriate.

[0044] In the above-described first embodiment, the form in which a part of the lens barrel 30 is accommodated in the concave portion 31 of the first housing 10 was described. In the second embodiment, the form in which the entire lens barrel 30 is accommodated in the concave portion of the first housing 10 will be described.

[0045] The concave portion 32 of the first housing 10 accommodates the entire lens barrel 30. In a state where the lens barrel 30 is accommodated in the concave portion 32, in the optical axis direction (on the Z-axis) of the lens barrel 30, the tip of the first housing 10 and the tip of the lens barrel 30 are at substantially the same position. That is, the tip of the first housing 10 and the tip of the lens barrel 30 overlap. Here, with reference to FIG. 5, the state in which the lens barrel 30 is accommodated in the first housing 10 will be described.

[0046] As shown in FIG. 5, the entire lens barrel 30 is accommodated in the concave portion 32 of the first housing 10. By accommodating the entire lens barrel 30 in the concave portion 32 of the first housing 10, the contact area between the first housing 10 and the lens barrel 30 can be further increased. As a result, the exposed portion of the lens unit (the portion not accommodated in the first housing 10) is reduced, and thus the lens unit is less affected by the temperature from the exposed portion.

[0047] That is, the heat dissipation member 70 can conduct the heat from the first housing 10 to the entire lens barrel 30. Thereby, in the imaging device 200 of the second embodiment, the temperature difference between the first housing 10 and the inside of the lens barrel 30 can be made smaller more efficiently. Therefore, the imaging device 200 of the second embodiment can more efficiently reduce the dew condensation of the lens 40.

[0048] Incidentally, the above-described embodiments can be appropriately modified and implemented by changing a part of the configuration of the above-described apparatus. Therefore, below, some modifications according to the above-described embodiments will be described as other embodiments. Note that below, mainly the differences from the above-described embodiments will be described, and detailed descriptions of the points common to the already described content will be omitted. Also, the modifications described below may be implemented individually or in appropriate combinations.

[0049] (Modification example) In the above-described embodiment, the number of substrates 50 was described as two, but it should not be limited to this. For example, the number of substrates 50 may be one, or may be three or more. That is, regardless of the number of substrates 50, a configuration in which a heat dissipation member 70 is provided on the substrate 50 is sufficient.

[0050] Note that the above-described embodiments are presented as examples and are not intended to limit the scope of the present disclosure. The above embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. The above embodiments are included in the scope or gist of the present disclosure, and are included in the invention described in the claims and the equivalent scope thereof.

Explanation of reference numerals

[0051] 10 First housing 20 Second housing 30 Lens barrel 40 Lens 46 IR cut filter 50 Substrate 54 First fixing member 55 Second fixing member 56 Sensor 60 Sealing member 61 Sealing agent 71 First heat dissipation member 72 Second heat dissipation member 100, 200 Imaging device

Claims

**Claim 1**: A cylindrical lens barrel that houses a lens, a sensor that converts light received through the lens into an image signal, a substrate having a first surface and a second surface opposite the first surface, with the sensor disposed on the first surface, a housing having an inner peripheral side surface and an outer peripheral side surface, the housing housing the lens barrel, the sensor, and the substrate, a first heat dissipation member disposed between the outer peripheral surface of the lens barrel and the inner peripheral side surface of the housing, thermally connecting the lens barrel and the housing, comprising: The first heat dissipation member is in the form of a sheet, wound around the outer peripheral surface of the lens barrel, and in contact with the outer peripheral surface of the lens barrel and the inner peripheral side surface of the housing. An in-vehicle camera. **Claim 2** The tip of the lens barrel protrudes from the housing. The in-vehicle camera according to claim 1. **Claim 3** The tip of the lens barrel overlaps with the tip of the housing. The in-vehicle camera according to claim 1. **Claim 4** The first heat dissipation member is provided along the outer peripheral surface of the lens barrel. The in-vehicle camera according to any one of claims 1 to 3. **Claim 5** Further comprising a second heat dissipation member that thermally connects the substrate and the housing. The in-vehicle camera according to any one of claims 1 to 4. **Claim 6** The second heat dissipation member is disposed in contact with the second surface of the substrate and in contact with the inner peripheral side surface and the bottom surface of the housing. The in-vehicle camera according to claim 5.

Images