Camera Module

Abstract

A camera module (1) is configured to capture an optical image (3) of a target area and includes a lens member (10), an imager (20), a light transmission member (40) and a base (60). The lens member is configured to receive light from the target area. The imager has a curved portion (203) protruding in a direction away from the lens member and is configured to capture an optical image formed on the curved portion by light passing through the lens member. The light transmission member optically couples the lens member and the imager and allows light from the lens member to be transmitted toward the imager. The base has a support portion (601) supporting an outer edge of the imager and a fluid space (602) defined inside the support portion. A heat dissipation fluid (603, 2603) undergoes convection in the fluid space. The support portion and the fluid space of the base are located on a side of the curved portion opposite to the light transmission member.

Description

Technical Field

[0001] The present disclosure relates to a camera module. Background Art

[0002] Camera modules configured to capture an optical image of a target area are widely known. For example, a camera module disclosed in Patent Document 1 (JP2015-192074A) is configured to capture an optical image formed on a curved portion of an imager protruding in a direction away from an incident window.

[0003] In the camera module disclosed in Patent Document 1, a space is defined between the sealing glass of the incident window and the curved portion of the imager. Heat generated in the imager can be dissipated into the space. However, in the space on the incident side of the curved portion on which an optical image is formed, the refractive index of the air heated by the heat dissipation from the imager may change, and thus the optical characteristics of the incident light may change. In this case, the accuracy of capturing the optical image may deteriorate. Summary of the invention

[0004] An object of the present disclosure is to provide a camera module that achieves both capturing accuracy and heat dissipation.

[0005] According to a first aspect of the present disclosure, a camera module is configured to capture an optical image of a target area and includes a lens member, an imager, an optical transmission member, and a base. The lens member is configured to receive light from the target area. The imager has a curved portion that protrudes in a direction away from the lens member and is configured to capture an optical image formed on the curved portion by light passing through the lens member. The optical transmission member optically couples the lens member and the imager and allows light from the lens member to be transmitted toward the imager. The base has a support portion and a fluid space, wherein the support portion supports an outer edge of the imager, and the fluid space is defined on an inner side of the support portion. The heat dissipation fluid undergoes convection in the fluid space. The support portion and the fluid space of the base are located on a side of the curved portion opposite to the optical transmission member.

[0006] According to the first aspect, the lens member into which light from the target area enters and the imager in which an optical image is formed on the curved portion are optically coupled to each other through the light transmission member, wherein the light transmission member allows the light from the lens member to be transmitted through the light transmission member to the imager. Accordingly, on the incident side of the curved portion (from which light enters the curved portion), changes in optical characteristics of light can be suppressed by the light transmission member whose refractive index may be stabilized.

[0007] According to the first aspect, on the opposite side of the bent portion opposite to the light transmission member, the fluid space in which the heat dissipation fluid undergoes convection is defined inside the support portion supporting the outer edge of the imager. Accordingly, since the heat dissipated from the bent portion to the fluid space is transferred to the heat dissipation fluid, the heat dissipation fluid undergoing convection exhibits heat dissipation.

[0008] According to the first aspect, high capture accuracy can be achieved by suppressing changes in optical characteristics, and heat dissipation can be achieved at the same time.

[0009] According to a second aspect of the present disclosure, the camera module is configured to capture a target area outside a vehicle. According to the second aspect, even in a vehicle that tends to heat up, high capture accuracy can be achieved by suppressing changes in optical characteristics due to the principle described in the first aspect, and high heat dissipation performance can be achieved at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a cross-sectional view of a camera module according to the first embodiment.

[0011] Figure 2 is a schematic diagram showing an optical image captured by the camera module according to the first embodiment.

[0012] Figure 3 is a schematic diagram for explaining the optical structure of the camera module according to the first embodiment.

[0013] Figure 4 is a cross-sectional view of a camera module according to a second embodiment.

[0014] Figure 5 yes Figure 1 A cross-sectional view of a modified example of .

[0015] Figure 6 yes Figure 1 A cross-sectional view of a modified example of .

[0016] Figure 7 yes Figure 1 A cross-sectional view of a modified example of .

[0017] Figure 8 yes Figure 1 A cross-sectional view of a modified example of .

[0018] Fig. 9 yes Figure 1 A cross-sectional view of a modified example of .

[0019] Fig.10 yes Figure 1 A cross-sectional view of a modified example of . DETAILED DESCRIPTION

[0020] Hereinafter, various embodiments will be described with reference to the accompanying drawings. In the following description, the same reference symbols are assigned to the corresponding parts in each embodiment to avoid repeated descriptions. When only a part of a configuration is described in the corresponding embodiment, the configuration of other embodiments described before can be applied to the other parts of the configuration. In addition, not only the combination of each configuration is clearly shown in the description of the corresponding embodiment, but also the configurations of multiple embodiments can be partially combined together if there is no specific problem in the combination, even if multiple configurations are not clearly shown.

[0021] (First embodiment)

[0022] Figure 1 The camera module 1 of the first embodiment shown is configured to capture an optical image 3 of a target area. The camera module 1 is mounted on a vehicle to capture the exterior of the vehicle as a target area. The camera module 1 includes a lens member 10, an imager 20, an imaging substrate 30, a light transmission member 40, a lens barrel 50, and a base 60.

[0023] The lens member 10 is located on the optical path of the light from the target area. The lens member 10 is made of a transparent hard material (such as glass) with a low thermal expansion coefficient and a high refractive index. The lens member 10 has a single lens structure in front of the imager 20. One side of the lens member 10 is an input lens surface 100, which is a convex lens surface convex toward the target area. The other side of the lens member 10 is an output lens surface 101, which is a convex lens surface convex in a direction away from the target area. The lens surfaces 100, 101 are arranged in a direction including Figure 1 Any of the cross sections shown has a curved shape including a non-spherical shape and a spherical shape. That is, the lens member 10 of the first embodiment is a biconvex lens having two convex surfaces.

[0024] The optical axis of the lens member 10 coincides with the optical axis A1 of light from the target area to the imager 20. The light from the target area enters the lens member 10 along the optical axis A1. The lens member 10 passes through Figure 3 The combined use of lens surfaces 100, 101 as shown provides optical positive power to light from the target area and allows light to be transmitted through lens member 10 to imager 20. Output lens surface 101 of lens member 10 may be a curved optical surface convex toward imager 20.

[0025] Figure 1The imager 20 shown is arranged on the optical path of light from the target area and is located on the opposite side of the lens member 10 opposite to the target area. The imager 20 is a thin semiconductor device in which an imaging element 200 is mounted on a silicon wafer or the like. The imager 20 has a curved portion 203. The curved portion 203 has an arcuate shape with a substantially constant thickness. The curved portion 203 protrudes in a direction away from the lens member 10. The curved portion 203 of the first embodiment is composed of the entire imager 20. Therefore, the imager 20 has an arcuate shape as a whole.

[0026] One side of the curved portion 203 is an input concave surface 204 that is concave in the direction away from the lens member 10. The other side of the curved portion 203 is a heat dissipation convex surface 205 that is convex in the direction away from the lens member 10. The surfaces 204 and 205 include Figure 1 Any of the cross-sections shown have a curved shape including non-spherical and spherical shapes. The input concave surface 204 has a curved shape that is substantially complementary to the output lens surface 101 of the lens member 10. The input concave surface 204 may have a gradual or abrupt curved shape.

[0027] The imaging element 200 is a color or monochrome type semiconductor device, such as a CCD or a CMOS. The imaging element 200 has pixels arranged in a matrix. The imaging element 200 is included in a curved portion 203. The imaging surface of the imaging element 200 is recessed to become a part of the input concave surface 204. The effective imaging area of ​​the imaging element 200 capable of detecting light is positioned substantially coaxially with the optical axis Al of the light from the target area to the imager 20. The imaging element 200 of the first embodiment has an effective imaging area on the inner side of the outer edge 206 of the curved portion 203 that coincides with the outer edge 202 of the imager 20. That is, the effective imaging area of ​​the imaging element 200 is formed at a portion of the curved portion 203 excluding the outer edge 206.

[0028] like Figure 3 As shown, the imaging element 200 receives light from the target area that has passed through the lens member 10 along the optical axis A1. Therefore, due to the positive optical power of the lens member 10, the optical image 3 is formed on the effective imaging area of ​​the imaging element 200 in the curved portion 203. In contrast, the optical image 3 of the target area is not formed on the outer edge 206 of the curved portion 203 that is located outside the effective imaging area of ​​the imaging element 200. The imaging element 200 is configured to capture the optical image 3 of the target area formed on the effective imaging area and output a capture signal.

[0029] Figure 1The imaging substrate 30 shown is arranged outside the optical path of the light from the target area to the imager 20. The imaging substrate 30 is located on the opposite side of the imager 20 relative to the lens member 10. The imaging substrate 30 is a circuit board having a flat shape extending in a direction perpendicular to the optical axis A1 of the light from the target area. The imaging substrate 30 includes a base substrate 300 and a soft flexible printed circuit board (FPC) 301 integrated with each other. The base substrate 300 is made of a hard material with high thermal conductivity, such as stainless steel (SUS). An imaging circuit 302 as a part of the imaging substrate 30 is included in the flexible printed circuit board 301 of the imaging substrate 30 or is mounted on the flexible printed circuit board 301 of the imaging substrate 30.

[0030] The imaging circuit 302 includes a plurality of circuit elements. The imaging circuit 302 is wire-bonded to a portion 303 of the imager 20 located on the outside of the outer edge 202 of the imager 20. In the first embodiment, the portion 303 is located on the outside of the outer edge 206 of the bend 203. Therefore, the imaging circuit 302 is electrically connected to the imaging element 200 of the imager 20. The imaging circuit 302 is configured to control the capture performed by the imaging element 200. Therefore, the imaging circuit 302 is configured to process the capture signal output from the imaging element 200. In addition, the imaging circuit 302 can be configured to generate an image signal indicating a capture result of the target area by performing image processing on the capture signal output from the imaging element 200.

[0031] The light transmission member 40 is located on the optical path of the light from the target area and between the lens member 10 and the imager 20. The light transmission member 40 is made of a transparent hard material (such as glass) with a low thermal expansion coefficient. The light transmission member 40 has a thick sheet shape and is sandwiched by the lens member 10 and the imager 20.

[0032] One side of the light transmission member 40 is an input concave surface 400 that is concave toward the imager 20 in a direction away from the lens member 10. The other side of the light transmission member 40 is an output convex surface 401 that is convex toward the imager 20 in a direction away from the lens member 10. The surfaces 400 and 401 are arranged in a direction including Figure 1 Any of the cross sections shown have a curved shape including aspherical and spherical shapes. Input concave surface 400 has a curved shape substantially complementary to output lens surface 101 of lens member 10. Output convex surface 401 has a curved shape substantially complementary to input concave surface 204 of imager 20.

[0033] The input concave surface 400 is coaxially aligned with and in close contact with the output lens surface 101. The input concave surface 400 of the first embodiment is physically bonded and fixed to the output lens surface 101 of the lens member 10 by an optical adhesive or the like, whereby the light-transmitting member 40 is integrated with the lens member 10. In contrast, the output convex surface 401 is coaxially aligned with and in close contact with the input concave surface 204. The output convex surface 401 of the first embodiment is physically separated from and stacked on the input concave surface 204 of the imager 20.

[0034] Therefore, the light transmission member 40 optically couples the lens member 10 and the imager 20 to each other. The light transmission member 40 allows light from the target area, which has passed through the lens member 10 , to reach the imager 20 through the light transmission member 40 along the optical axis A1 .

[0035] The lens barrel 50 is arranged so as to extend from the periphery of the optical path of the light toward the imager 20 from the target area to the portion outside the optical path. The lens barrel 50 is located outside the component 10-40. The lens barrel 50 is made of a light-shielding hard material (e.g., a thermosetting resin) with a low thermal expansion coefficient. The lens barrel 50 has a stepped cylindrical shape with openings on both sides.

[0036] The open end portion 500 on the small diameter side of the lens barrel 50 is externally fitted and fixed to the lens member 10 and the light transmission member 40. The end surface on the large diameter side of the lens barrel 50 is attached to and adhered to the surface 304 of the flexible printed circuit board 301 facing away from the base substrate 300. Therefore, the lens member 10 and the light transmission member 40 supported by the lens barrel 50 are also indirectly supported by the imaging substrate 30 through the lens barrel 50.

[0037] Figure 1 The base 60 shown is disposed outside the optical path of light from the target area to the imager 20. The base 60 is located on the opposite side of the curved portion 203 of the imager 20, which is opposite to the lens member 10 and the light transmission member 40. The base 60 is located between the curved portion 203 and the flexible printed circuit board 301 of the imaging substrate 30. The base 60 is made of a light-shielding hard material (e.g., a thermosetting resin) having a low thermal expansion coefficient. The base 60 has a straight cylindrical shape with openings on both sides. The base 60 includes a support portion 601 and a fluid space 602.

[0038] The support portion 601 is a cylindrical wall or a side wall of the base 60. One side end surface of the support portion 601 is attached to and adhered to the outer edge 202 of the heat dissipation convex surface 205 of the imager 20 (the outer edge 206 of the bent portion 203 in the first embodiment). Therefore, the support portion 601 supports the outer edge 202 of the imager 20, and the optical image 3 of the target area is not substantially formed on the outer edge 202 of the imager 20. The other side end surface of the support portion 601 is attached to and adhered to the surface 304 of the flexible printed circuit board 301 of the imaging substrate 30. The lens barrel 50 is also adhered to the surface 304. Therefore, the imager 20 supported by the support portion 601 is also indirectly supported by the imaging substrate 30.

[0039] The fluid space 602 is defined inside the support portion 601. The fluid space 602 is defined by the support portion 601, the bent portion 203 of the imager 20, and the flexible printed circuit board 301 of the imaging substrate 30. The heat dissipation convex surface 205 of the bent portion 203 completely covers one opening of the support portion 601 and is exposed to the fluid space 602 defined inside the support portion 601. The surface 304 of the flexible printed circuit board 301 completely covers the other opening of the support portion 601 and is exposed to the fluid space 602. Therefore, the heat generated in the imaging element 200 is dissipated from the heat dissipation convex surface 205 to the fluid space 602. In addition, the heat generated in the imaging substrate 30 is dissipated from the surface 304 to the fluid space 602. The heat dissipation fluid that undergoes convection due to the heat dissipated from the heat dissipation convex surface 205 and the surface 304 is enclosed in the fluid space 602. In the first embodiment, air is used as the heat dissipation fluid 603.

[0040] According to the first embodiment described above, the lens member 10 into which light from the target area enters and the imager 20 in which the optical pattern 3 is formed on the curved portion 203 are optically coupled to each other through the light transmission member 40, and the light transmission member 40 allows the light from the lens member 10 to be transmitted through the light transmission member 40 to be transmitted to the imager 20. Accordingly, on the incident side of the curved portion 203 (from which the light enters the curved portion 203), changes in the optical characteristics of the light can be suppressed by the light transmission member 40 whose refractive index may be stable.

[0041] According to the first embodiment, on the opposite side of the bent portion 203 opposite to the light-transmitting member 40, a fluid space 602 in which the heat dissipation fluid 603 undergoes convection is defined inside the support portion 601 supporting the outer edge 202 of the imager 20. According to this, since the heat dissipated from the bent portion 203 to the fluid space 602 is transferred to the heat dissipation fluid 603, the heat dissipation fluid 603 undergoing convection exhibits heat dissipation.

[0042] According to the first embodiment, high capturing accuracy can be achieved by suppressing changes in optical characteristics, and heat dissipation can be achieved at the same time.

[0043] In the fluid space 602 of the first embodiment, air is enclosed as the heat dissipation fluid 603. This can improve the manufacturing capability and productivity of the heat dissipation structure.

[0044] The support portion 601 of the first embodiment supports the outer edge 202 of the imager 20 on which the optical image 3 is not formed. According to this, in addition to the outer edge 202 on which the optical image 3 is not formed, a part of the curved portion 203 on which the optical image 3 is formed can be exposed to the fluid space 602. Therefore, high capture accuracy and high heat dissipation can be obtained.

[0045] In the first embodiment, the imaging substrate 30 connected to the imager 20 by wire bonding is exposed to the fluid space 602 defined in the cylindrical support portion 601 from the other side opposite to the bent portion 203. According to this, since the heat dissipated from the imaging substrate 30 to the fluid space 602 is transferred to the heat dissipation fluid 603, the heat dissipation fluid 603 undergoing convection exhibits heat dissipation performance. Therefore, high capture accuracy can be achieved by suppressing changes in optical characteristics, and high heat dissipation performance can be achieved at the same time.

[0046] According to the first embodiment, the lens member 10 and the light transmission member 40 are supported by the lens barrel 50 fixed to the imaging substrate 30 in addition to the base 60 supporting the curved portion 203 of the imager 20. According to this, the lens member 10 and the imager 20 sandwiching the light transmission member 40 can be accurately optically positioned. Therefore, the capture accuracy can be improved in combination with suppressing the change in optical characteristics.

[0047] According to the first embodiment, the lens member 10 having the output lens surface 101 convex toward the imager 20 provides positive power to light. Accordingly, by cooperating with the curved portion 203 curved in a direction away from the lens member 10, the angle of view for determining the target area can be widened even with a small imager 20. Therefore, it is possible to suppress changes in the optical characteristics of light from a wide target area and improve capture accuracy.

[0048] According to the light transmission member 40 of the first embodiment, the input concave surface 400 is in contact with the output lens surface 101 of the lens member 10, and the output convex surface 401 is in contact with the curved portion 203 of the imager 20. According to this, the lens member 10 and the imager 20 sandwiching the light transmission member 40 can be optically accurately positioned. In addition, the shape of the curved portion 203 of the imager 20, which is required to have a widened viewing angle, can be fixed. Therefore, the capture accuracy can be improved in combination with the suppression of the change in the optical characteristics.

[0049] According to the first embodiment, the input concave surface 400 of the light transmission member 40 is physically bonded to the output lens surface 101 of the lens member 10. According to this, the lens member 10 and the imager 20 sandwiching the light transmission member 40 can be accurately positioned. Therefore, the capture accuracy can be improved in combination with the suppression of the change in optical characteristics.

[0050] The camera module 1 of the first embodiment is configured to capture a target area outside a vehicle. According to the above principle, even in a vehicle that tends to heat up, high capture accuracy can be achieved by suppressing changes in optical characteristics, and high heat dissipation performance can be achieved at the same time.

[0051] (Second embodiment)

[0052] Figure 4 The second embodiment shown is a modification of the first embodiment.

[0053] In the second embodiment, the heat dissipation fluid 2603 is enclosed in the fluid space 602, and undergoes convection as heat is dissipated from the heat dissipation convex surface 205 of the bent portion 203 of the imager 20 and from the surface 304 of the flexible printed circuit board 301 of the imaging substrate 30. The heat dissipation fluid 2603 may be a liquid metal having a high thermal conductivity of 10 W / m·K or more, such as a liquid Ga—In—Sn alloy.

[0054] As described above, the heat dissipation fluid 2603 is enclosed in the fluid space 602 of the second embodiment. This allows high heat dissipation.

[0055] (Other embodiments)

[0056] Although a plurality of embodiments have been described above, the present disclosure is not construed as being limited to these embodiments, and may be applied to various embodiments and combinations within the scope not departing from the gist of the present disclosure.

[0057] In a modified example of the first and second embodiments, the lens member 10 may be a single convex lens, in which only the output lens surface 101 is convex, such as Figure 5 In this case, the input lens surface 100 may be as shown Figure 5 The flat surface as shown, or a concave surface (not shown), is acceptable as long as lens element 10 provides positive optical power to light passing therethrough.

[0058] In another modified example of the first and second embodiments, as Figure 6 As shown, the outer edge 202 of the imager 20 supported by the support portion 601 of the base 60 may be flat. In this case, the curved portion 203 of the imager 20 is located on the inner side of the outer edge 202, as shown in FIG. Figure 6In addition, in this case, the effective imaging area of ​​the imaging element 200 is formed in at least a portion of the curved portion 203 located inside the outer edge 202 of the imager 20 .

[0059] In another modified example of the first and second embodiments, as Figure 7 As shown, the imaging substrate 30 can be a printed circuit board 305 having printed conductors on a base material such as resin, ceramic or alumina. In this case, the surface 304 is one side of the printed circuit board 305.

[0060] In another modified example of the first and second embodiments, as shown in FIG. Figure 8 As shown, one of the lens member 10 or the light transmitting member 40 that are physically coupled to each other is not supported by the lens barrel 50. Figure 8 , the light transmission member 40 is not supported by the lens barrel 50. In another modified example of the first and second embodiments, the light transmission member 40 may be physically separated from the lens member 10, and the input concave surface 400 of the light transmission member 40 may be stacked on the input lens surface 101 of the lens member 10.

[0061] In another modified example of the first and second embodiments, the output convex surface 401 of the light transmission member 40 may be physically bonded to the input concave surface 204 of the imager 20 by an optical adhesive or the like. In this case, Fig. 9 As shown, the lens barrel 50 may be omitted.

[0062] In a modified example of the first embodiment, Fig.10 As shown, the support portion 601 of the base 60 may have a vent hole 604, and the fluid space 602 and the outside are connected to each other through the vent hole 604. In this case, as shown in FIG. Fig.10 As shown, the lens barrel 50 may have a vent hole 501 through which the inside and the outside of the lens barrel 50 communicate with each other.

[0063] In a modified example of the second embodiment, the heat dissipation fluid 2603 may be a fluid other than liquid metal, such as water. In another modified example of the first and second embodiments, the camera module 1 may be mounted on an object other than a vehicle.

[0064] Additional advantages and modifications will readily occur to those skilled in the art.The disclosure in its broader terms is therefore not limited to the specific details, representative apparatus, and illustrative examples shown and described.

Claims

1. A camera module (1) configured to capture an optical image (3) of a target area, the camera module comprising: a lens member (10) configured to receive light from the target area; an imager (20) having a curved portion (203) convex in a direction away from the lens member, the imager being configured to capture the optical image formed on the curved portion by light passing through the lens member; a light transmission member (40) optically coupling the lens member and the imager, the light transmission member allowing light from the lens member to be transmitted toward the imager; as well as A base (60) having A support portion (601) supporting an outer edge (202) of the imager; as well as A fluid space (602) is defined inside the support portion, in which a heat dissipation fluid (603, 2603) undergoes convection, wherein The support portion of the base and the fluid space are located on a side of the curved portion opposite to the light-transmitting member, wherein The liquid is enclosed in which the fluid space (602) serving as the heat dissipation fluid is defined by the support portion (601) and the curved portion (203) of the imager (20), and The bent portion (203) has a heat dissipation convex surface (205), and the heat dissipation convex surface (205) is exposed to the fluid space (602) to dissipate heat generated by the imager (20) toward the fluid space (602).

2. The camera module according to claim 1, wherein: Air is enclosed in the fluid space as the heat dissipation fluid.

3. The camera module according to any one of claims 1 to 2, wherein: The support portion supports an outer edge of the imager on which no optical image is formed.

4. The camera module according to any one of claims 1 to 2, further comprising: an imaging substrate (30) connected to the imager by wire bonding, wherein the support portion has a cylindrical shape, and The imaging substrate is exposed to the fluid space from the other side of the support portion, the other side being the opposite side to the side where the bent portion is located.

5. The camera module according to claim 4, further comprising a lens barrel (50) configured to hold the lens member and the light transmitting member, in, The base and the lens barrel are fixed to the imaging substrate.

6. The camera module according to any one of claims 1 to 2, wherein: The lens member has an output lens surface (101) convex toward the imager, and The lens element is configured to provide positive optical power to light.

7. The camera module according to claim 6, wherein: The light transmission member has An input concave surface (400) that is in contact with the output lens surface; and A convex surface (401) is output, which is in contact with the curved portion.

8. The camera module according to claim 7, wherein: The output lens surface and the input concave surface are physically engaged with each other.

9. The camera module according to any one of claims 1 to 2, wherein: The camera module is configured to capture a target area outside the vehicle.

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