Lens unit, camera module, imaging system, and mobile object

Abstract

Provided are a lens unit in which a heater can bear pressure and a shift of an O-ring to the image side can be prevented when a first lens is crimped, a camera module, an imaging system, and a mobile object.　This lens unit comprises: a plurality of lenses that are arranged along an optical axis; a lens barrel (12) that accommodates and holds the plurality of lenses: a first lens (13) that is located closest to the object side; a second lens (24) that adjoins the first lens (13) in the optical axis direction; a heater (40) that is provided between the first lens and the second lens and can heat the first lens; and a heater device (50) that houses the heater (40). The heater (40) is inserted between the first lens (13) and the second lens (14) in a state of being housed in the heater device (50).

Description

Lens unit, camera module, imaging system and mobile object

[0001] The present invention particularly relates to a lens unit, a camera module, an imaging system, and a moving body equipped with an imaging system, which constitute an on-board camera mounted on a vehicle such as an automobile.

[0002] In recent years, automobiles have been equipped with on-board cameras to assist with parking and prevent collisions through image recognition, and attempts have also been made to apply these to autonomous driving. The camera module of such on-board cameras generally includes a lens unit having a lens group consisting of a plurality of lenses arranged along an optical axis, a lens barrel that houses and holds the lens group, and an aperture member disposed between at least one of the lenses in the lens group (see, for example, Patent Document 1).

[0003] Lens units (camera modules) having the above configuration can be used in various optical devices, not just in vehicle-mounted cameras. However, when exposed to the external environment in cold regions, freezing of the lens surface and accumulation of snow on the lens are anticipated, and therefore, such lens units are generally provided with a snow-melting function. Specifically, as shown in FIG. 10 , such lens units have a planar heater 40 interposed between a flange 13f of the first lens 13 and a flange 14f of a second lens 14 adjacent to the first lens 13, in order to heat the first lens 13, which is located closest to the object among the lens group L housed and held in the lens barrel 12 and exposed from the lens barrel 12 (exposed to the external environment). Note that hatching of the first lens 13 and the second lens 14 is omitted in FIG. 10 . Furthermore, a ring-shaped protrusion 14p that protrudes toward the object side (upper side in FIG. 10 ) is provided on the inner diameter portion of the flange portion 14f of the second lens 14, and by abutting this protrusion 14p against the flange portion 13f of the first lens 13, a gap is formed between the flange portions 13f, 14f, and a heater 40 is inserted into this gap. A power supply unit 41 made of a flexible printed circuit board or the like is connected to the heater 40, and supplies power to the heater 40. Furthermore, an O-ring (sealing member) 26 is provided between the first lens 13 and the lens barrel 12 to seal the gap.

[0004] The heater 40 thus incorporated in the lens barrel 12 is widely used as the most effective heating means capable of efficiently transferring the generated heat to the surface of the first lens 13 .

[0005] JP 2013-231993 A

[0006] When assembling the lens unit as described above, multiple lenses are sequentially inserted through the opening on the object side of the lens barrel (upper side in FIG. 10 ), and after inserting the second lens 14, a planar heater 40 is placed on the flange portion 14f of the second lens 14, and the first lens 13 is placed on the second lens 14 so as to sandwich the heater 40. Finally, the multiple lenses including the lenses 13, 14 (FIG. 10 shows only the first lens 13 and the second lens 14 among the multiple lenses) are fixed to the lens barrel 12 by crimping the crimping portion 23 provided on the object side end of the lens barrel. During this crimping, the first lens 13 is pressed toward the image side (lower side in FIG. 10 ), and the heater 40 is pressed toward the image side by the first lens 13. However, to prevent the heater 40 from receiving excessive pressure, the protrusion 14p is provided on the inner diameter portion of the flange portion 14f of the second lens 14, as described above.

[0007] The larger the radial width w of the protrusion 14p, the more firmly the protrusion 14p can withstand the pressing force of the first lens 13 due to crimping. However, since the radial width of the heater 40 becomes smaller by the amount of increase in the width w of the protrusion 14p, the width w of the protrusion 14p cannot be made larger than necessary.

[0008] Therefore, if the protrusion 14p is deformed and crushed by the pressure during crimping, a large pressure acts on the heater 40 from the first lens 13 and the second lens 14, preventing the heater 40 from achieving its intended heating performance. If the heater 40 is, for example, a PTC heater, the electrical resistance value increases due to the pressure described above even in the initial stage when no power is applied, preventing the heater 40 from heating up to the desired temperature and reducing its heating performance. Furthermore, because the heater 40 is thin, if the heater 40 is damaged by the pressure described above, the heater 40 will not be able to achieve its intended heating performance.

[0009] Furthermore, since the gap below the O-ring 26 is large and there is no support for the O-ring 26, there is a concern that the O-ring 26 may come off if it shifts downward (towards the image), or that the first lens 13 may be displaced during a high-pressure car wash.

[0010] The present invention has been made in consideration of the above circumstances, and aims to provide a lens unit, a camera module, an imaging system, and a moving body that enable a heater to withstand the pressure applied when the first lens is crimped, and that can prevent the O-ring from shifting toward the image side.

[0011] In order to solve the above problem, the lens unit of the present invention comprises a plurality of lenses arranged along an optical axis, a lens barrel that houses and holds the plurality of lenses, a first lens that is located closest to the object, a second lens that is adjacent to the first lens in the optical axis direction, and a heater that is provided between the first lens and the second lens and is capable of heating the first lens, and is characterized in that the lens unit further comprises a heater device that houses the heater, and the heater is inserted between the first lens and the second lens while housed in the heater device.

[0012] Here, the heater device may be made of metal, ceramic, or engineering plastic resin such as polycarbonate, as long as it has the strength to prevent excessive pressure from acting on the heater even when it is subjected to pressure when crimping the first lens.

[0013] In the present invention, the heater is housed in a heater device and inserted between the first lens and the second lens, so the heater device can withstand the pressure applied when the first lens is crimped. This allows the heater to withstand the pressure applied when the first lens is crimped, thereby enabling the heater to exhibit its inherent performance.

[0014] In the above-described configuration of the present invention, a seal member may be provided to seal between the first lens and the lens barrel, and the outer periphery of the heater element may be located directly below the image side of the seal member.

[0015] With this configuration, the outer periphery of the heater element is located directly below the image side of the seal member, so the gap that previously existed below the seal member can be filled by the outer periphery of the heater element, preventing the seal member from shifting toward the image side and coming off, and preventing displacement of the first lens during high-pressure car washes.

[0016] In the above-described configuration of the present invention, the heater device may be provided with an opening on a surface facing the object side, through which the heater is exposed.

[0017] According to this configuration, an opening is provided on the surface of the heater device facing the object side, and the heater can be exposed through this opening, so that the first lens can be efficiently heated by the heater.

[0018] The present invention also provides a camera module having the lens unit, an imaging system having the camera module, and a mobile object equipped with the imaging system. The camera module, imaging system, and mobile object can achieve the same effects as the lens unit described above. Note that the term "mobile object" refers to any object that can move, such as a vehicle.

[0019] According to the present invention, the heater can withstand the pressure applied when the first lens is caulked, and the O-ring can be prevented from shifting toward the image side.

[0020] 1 is a schematic cross-sectional view of a lens unit according to an embodiment of the present invention. It is a cross-sectional view of a main part of the same. It is a schematic cross-sectional view of a main part of a heater and a heater unit of the same. It is a cross-sectional view taken along line A-A in FIG. 1. It is a cross-sectional view of a unit body of a heater unit of the same. (a) is a cross-sectional view of a main part of a heater and a heater unit of a first modified example, (b) is a cross-sectional view of a main part of a heater and a heater unit of a second modified example, (c) is a cross-sectional view of a main part of a heater and a heater unit of a third modified example, (d) is a cross-sectional view of a main part of a heater and a heater unit of a fourth modified example, and (e) is a cross-sectional view of a main part of a heater and a heater unit of a fifth modified example. It is a schematic cross-sectional view of a camera module according to an embodiment of the present invention. It is a schematic diagram of a vehicle as a moving body on which an imaging system (on-board system) equipped with a camera module according to an embodiment of the present invention is mounted. It is a block diagram showing the configuration of an imaging device constituting the imaging system shown in FIG. It is a schematic cross-sectional view of a main part of an example of a conventional lens unit.

[0021] An embodiment of the present invention will be described below with reference to the drawings. This embodiment can realize a highly reliable system, particularly in a sensing system, and contributes to the development of resilient infrastructure. This contributes to "9. Build resilient infrastructure, promote inclusive and sustainable development, and promote sustainable industrialization." This contributes to "9.1 Develop quality, reliable, sustainable, and resilient infrastructure, including regional and transborder infrastructure, to support economic development and human well-being, with a focus on affordable and equitable access for all," one of the Sustainable Development Goals (SDGs) advocated by the United Nations. The lens unit incorporating the heater of this embodiment described below is particularly intended for a camera module, such as an in-vehicle camera, and is, for example, fixed to the exterior surface of the vehicle, with wiring drawn into the vehicle and connected to a display or other device. Hatching is omitted for multiple lenses in FIGS. 1, 2, and 7.

[0022] FIG. 1 shows a lens unit 11 according to a first embodiment of the present invention. As shown, the lens unit 11 includes a cylindrical lens barrel 12 and an internal storage space S of the lens barrel 12. The six lenses, for example, include a first lens 13, a second lens 14, a third lens 15, a fourth lens 16, a fifth lens 17, and a sixth lens 18. The third lens 15 is supported by an intermediate ring 19 along with an IRCF (infrared cut filter) 20, forming a subassembly 21 in which the lenses and filters are integrated into a unit. The fourth lens 16 and the fifth lens 17 are cemented together to form a cemented lens 24. An aperture member 22A and an intermediate ring 27 are interposed between the second lens 14 and the third lens 15 in a superimposed state. An aperture member 22B is also interposed between the fifth lens 17 and the sixth lens 18. The aperture members 22A and 22B are either "aperture diaphragms" that limit the amount of transmitted light and determine the F-number, which is an index of brightness, or "light-blocking diaphragms" that block light rays that cause ghosts or light rays that cause aberrations. An in-vehicle camera equipped with such a lens unit 11 includes the lens unit 11, a substrate (not shown) having an image sensor, and an installation member (not shown) that installs the substrate on a vehicle such as an automobile.

[0023] In this embodiment, the first lens 13, which can be exposed to the outside, is a glass lens, and the other inner lenses 14 to 18, the second to sixth lenses 14 to 18, are all resin lenses made of resin (plastic), but this is not limiting. Furthermore, the lens barrel 12 that houses these lenses 13 to 18 is made of resin in this embodiment, but it may also be made of metal. Furthermore, the shape of the lens barrel and the lenses, the number of lenses, and the like can be set as desired depending on the application, etc.

[0024] The multiple lenses 13 to 18 fixed to and supported by the lens barrel 12 are arranged with their optical axes aligned, and the lenses 13, 14, 15, 16, and 17 are aligned along a single optical axis O to form a group of lenses L used for imaging. Furthermore, the surfaces of these lenses 13 to 18 may be provided with an anti-reflection film, a hydrophilic film, a water-repellent film, or the like, as needed.

[0025] In this embodiment, an O-ring (sealing member) 26 is interposed between the first lens 13, which is located closest to the object, and the lens barrel 12 to prevent water and dust from entering the lens group L inside the lens barrel 12. In this case, a stepped reduced-diameter portion 13b, the diameter of which is reduced at the image-side portion of the first lens 13, is provided on the outer circumferential surface 13a of the first lens 13. An O-ring 26 is attached to this reduced-diameter portion 13b, and the O-ring 26 is compressed radially between the outer circumferential surface 13a of the first lens 13 and the inner circumferential surface 12a of the lens barrel 12, thereby sealing the object-side end of the lens barrel 12. Note that the sealing member interposed between the first lens 13 and the lens barrel 12 is not limited to the O-ring 26, and may be any shape as long as it is an annular body that can seal the gap between the first lens 13 and the lens barrel 12.

[0026] Furthermore, with the lens group L assembled and housed within the internal housing space S of the lens barrel 12, a crimped portion 23 at the object-side end (the upper end in FIG. 1 ) of the lens barrel 12 is thermally crimped radially inward, thereby fixing the first lens 13, which is located closest to the object side of the lens group L, to the object-side end of the lens barrel 12 in the optical axis direction by this crimped portion 23. In this case, to ensure stable crimping, the portion of the first lens 13 that is pressed against the crimped portion 23 is formed as a flat portion 13c that is cut obliquely into a plane. Note that the means for fixing the first lens 13 to the object-side end of the lens barrel 12 in the optical axis direction is not limited to the crimped portion 23. For example, if the lens barrel 12 is made of metal, the first lens 13 may be fixed to the object-side end of the lens barrel 12 in the optical axis direction by a cap that is screwed onto the object-side end of the lens barrel 12.

[0027] Furthermore, an inner flange portion 28 having an opening with a diameter smaller than that of sixth lens 18, which is positioned closest to the image side in lens group L, is provided at the end (lower end in FIG. 1) of lens barrel 12. This inner flange portion 28 and crimped portion 23 hold and fix the multiple lenses 13-18 and diaphragm members 22A and 22B that make up lens group L within lens barrel 12 in the optical axis direction.

[0028] 1 and 2, this embodiment also includes a heater 40 disposed between the first lens 13 and the second lens 14 and capable of heating the first lens 14. The heater 40 is a PTC (positive temperature coefficient) heater that generates heat when powered and is formed in a thin ring shape. A power supply unit 41, formed of a flexible printed circuit board or the like, is connected to the heater 40 and supplies power to the heater 40. A guide groove 12g extending parallel to the optical axis O is formed on the inner surface 12a of the lens barrel 12. The guide groove 12g is formed in the side wall of the lens barrel 12 and communicates with a through-hole 12k that is perpendicular to the guide groove 12g. The power supply unit 41 passes through the guide groove 12g and then through the through-hole 12k to be drawn to the outside and connected to a power source via a connector.

[0029] 3 and 4 , the heater 40 includes a base 40a formed in the shape of an annular plate and a convex portion 40b protruding upward (toward the object) from the base 40a. The convex portion 40b is formed in the shape of an annular plate coaxial with the base 40a and serves as a heat-generating portion. The heater 40 is housed in a heater unit 50. The heater unit 50 is formed in the shape of an annular plate from a relatively hard metal such as steel or an aluminum alloy. The heater unit 50 includes a main body 50a formed in the shape of an annular plate, an outer diameter convex wall 50b formed on the outer diameter of the main body 50a in the circumferential direction and protruding upward (toward the object), and an inner diameter convex wall 50c formed on the inner diameter of the main body 50a in the circumferential direction and protruding upward (toward the object), with an opening 50d formed on the top surface. The depth d of the heater device 50 is greater than the height h of the heater 40, so that when the heater 40 is stored in the heater device 50, the upper surfaces of the outer diameter convex wall 50b and the inner diameter convex wall 50c of the heater device 50 are higher than the upper surface of the heater 40.

[0030] The heater 40 is housed in the heater device 50 and inserted between the flange portion 13f of the first lens 13 and the flange portion 14f of the second lens 14. In this state, the outer peripheral surface of the outer diameter convex wall 50b of the heater device 50 abuts against the inner peripheral surface 12a of the lens barrel 12, thereby positioning the heater device 50 in the radial direction. The heater device 50 housing the heater 40 is sandwiched between the flange portions 13f, 14f in the optical axis direction, thereby positioning the heater device 50 in the optical axis direction. When assembling the lens unit 11, the crimping portion 23 is crimped so that the heater device 50 receives pressure (pressing force) from the flange portions 13f, 14f of the upper and lower first lens 13 and second lens 14, preventing excessive pressure from acting on the heater 40.

[0031] An opening 50d is provided on the upper surface of the heater unit 50, and the upper surface of the convex portion 40b is in close contact with the flange portion 13f of the first lens 13 through this opening 50d. The outer periphery of the heater unit 50 is located directly below the image side of the O-ring (sealing member) 26, and the upper portion of the O-ring 26 is close to or in contact with the outer diameter convex wall 50b of the heater unit 50. Furthermore, as shown in Figures 3 and 5, a through hole 50e is formed in the unit body 50a of the heater unit 50, penetrating the unit body 50a in the thickness direction, and the power supply portion 41 connected to the heater 40 is inserted into this through hole 50e and led to the guide groove 12g.

[0032] According to this embodiment, the heater 40 is housed in the heater device 50 and inserted between the first lens 13 and the second lens 14, so the pressure applied when the first lens 13 is crimped can be received by the heater device 50. Therefore, the heater 40 can withstand the pressure applied when the first lens 13 is crimped, and can therefore exhibit its inherent heater performance.

[0033] Furthermore, because the outer periphery of the heater device 50 is located directly below the image side of the O-ring (sealing member) 26, the outer periphery of the heater device 50 can fill the gap that previously existed below the sealing member. This prevents the O-ring 56 from shifting toward the image side and coming off, and also prevents displacement of the first lens 13 during high-pressure car washing. Furthermore, an opening 50d is provided on the surface of the heater device 50 facing the object side, allowing the heater 40 to be exposed through this opening 50d. This allows the heater 40 to heat the first lens 13 efficiently.

[0034] In this embodiment, the heater 40 is housed in the heater unit 50, but the heater may be housed in a heater unit as follows: Figures 6(a) to 6(e) are cross-sectional views showing modified examples of the heater unit.

[0035] 6A, a heater unit 51 is used, which is the heater unit 50 of the above-described embodiment, turned upside down. The heater unit 51 has a unit body 51a formed in the shape of an annular plate, an outer diameter convex wall 51b formed on the outer diameter portion of the unit body 50a, extending in the circumferential direction, and protruding downward (toward the image), and an inner diameter convex wall 51c formed on the inner diameter portion of the unit body 50a, extending in the circumferential direction, and protruding downward (toward the image), with the underside forming an opening 51d. In the first modification, the heater 40 is housed in the heater unit 51 by being placed over the heater 40 from above (toward the object).

[0036] According to the first modified example, the upper surface of the heater 40 is covered by the unit body 51a, so the flange portion 13b of the first lens 13 does not come into contact with the heater 40. This reduces the pressing force acting on the heater 40 from the flange portion 13b of the first lens 13. Furthermore, because the lower surface of the heater unit 51 is open, the power supply unit 41 can be directly connected to the heater 40 without providing a through-hole 50e as in the embodiment.

[0037] 6(b), the shape of the heater unit 52 is different from that of the heater unit 51 of the first modified example. That is, in the first modified example, as shown in FIG. 6(a), a gap S exists between the heater 40 and the heater unit 51, but in the second modified example, a protrusion 52e for filling the gap S is formed integrally with the heater unit 52.

[0038] According to this second modified example, the same effect as the first modified example can be obtained, and since the gap S is filled with the convex portion 52e, the strength of the heater element 52 can be increased compared to the heater element 51.

[0039] 6(b), the heater 40 is covered with the heater unit 52, but in the third modified example shown in Fig. 6(c), the heater 40 is covered with the heater unit 52, and the heater 40 and the heater unit 52 are bonded and integrated with each other by an adhesive layer L. The adhesive layer L is formed on the joint surface between the heater 40 and the heater unit 52.

[0040] According to this third modified example, it is possible to obtain the same effect as the second modified example, and in addition, since the heater 40 and the heater unit 52 are integrated by the adhesive layer L, it is possible to form an integrated subassembly 60 in which the heater 40 is firmly fixed to the heater unit 52, and the integrated subassembly 60 can be easily incorporated between the flange portion 13f of the first lens 13 and the flange portion 14f of the second lens 14.

[0041] (Fourth Modification) In the second modification shown in Fig. 6(b), the heater 40 is covered with a heater unit 52, and the heater unit 52 completely covers the upper surface of the heater 40. However, in the fourth modification shown in Fig. 6(d), the heater unit 53 has an opening 53a on its upper surface, which exposes the upper surface of the convex portion 40b, which is the heat-generating portion of the heater 40. In addition, the upper surface (the surface facing the object) of the heater unit 53 is higher than the upper surface of the convex portion 40b of the heater 40. Therefore, by inserting the heater unit 53 containing the heater 40 between the flange portion 13f of the first lens 13 and the flange portion 14f of the second lens 14, the upper surface of the convex portion 40b of the heater 40 comes close to the flange portion 13f.

[0042] According to the fourth modified example, it is possible to obtain the same effect as the second modified example, and in addition, since the convex portion 40b, which is the heat generating portion of the heater 40, is exposed and is directly adjacent to the flange portion 13f of the first lens 13, the first lens 13 can be heated by the heater 40 more efficiently than in the second modified example.

[0043] (Fifth Modification) In the fifth modification shown in Fig. 6(e), the thickness of the upper surface of the heater element 54 is thicker than the thickness of the upper surface of the heater element 53 of the fourth modification shown in Fig. 6(d) (the heater element 54 is accordingly thicker than the heater element 53), and a step 54d is provided on the rear side of the upper surface. This step 54d makes the heater 40 thicker than the heater 40 of the fourth modification. The heater element 54 has an opening 54a on the upper surface side, which exposes the upper surface of the protrusion 40b, which is the heat-generating portion of the heater 40, but the exposed area is smaller than in the fourth modification. By inserting the heater device 54 containing the heater 40 between the flange portion 13f of the first lens 13 and the flange portion 14f of the second lens 14, a gap is created between the upper surface of the convex portion 40b of the heater 40 and the flange portion 13f, and the flange portion 13b of the first lens 13 does not abut against the convex portion 40b of the heater 40.

[0044] According to the fifth modified example, it is possible to obtain the same effect as the fourth modified example, and in addition, since the flange portion 13b of the first lens 13 does not abut against the convex portion 40b of the heater 40 and the heater element 54 is thicker than the heater element 53, the pressing force acting from the flange portion 13b of the first lens 13 on the heater 40 can be reduced compared to the fourth modified example.

[0045] 7 is a schematic cross-sectional view of a camera module 300 of this embodiment having the lens unit 11 configured as described above. As shown in the figure, the camera module 300 includes an upper case (camera case) 301, which is an exterior component, and a mount (base) 302 that holds the lens unit 11. The camera module 300 also includes a seal member 303 and a package sensor (imaging element; image sensor) 304.

[0046] The upper case 301 is a member that engages with a flange portion 25 that is provided like a brim on the outer peripheral surface of the lens barrel 12, and that covers the other portions of the lens unit 11, leaving the object-side end of the lens unit 11 exposed. The mount 302 is disposed inside the upper case 301, and has an internal thread 302a that screws into the external thread 11a of the lens unit 11. The sealing member 303 is a member that is interposed between the inner surface of the upper case 301 and the outer peripheral surface of the lens barrel 12 of the lens unit 11, and is a member that maintains airtightness inside the upper case 301.

[0047] The package sensor 304 is disposed inside the mount 302 and is positioned to receive the image of the object formed by the lens unit 11. The package sensor 304 is equipped with a CCD, CMOS, or the like, and converts the light that is collected and reaches the package sensor 304 through the lens unit 11 into an electrical signal. The converted electrical signal is then converted into analog data or digital data, which are components of the image data captured by the camera.

[0048] FIG. 8 schematically illustrates a vehicle 240 as a moving object equipped with an in-vehicle system (imaging system) including an imaging device 250 including the camera module 300 shown in FIG. 7 . As illustrated, the imaging device 250 can be mounted on the vehicle 240, and FIG. 8 illustrates an example of the mounting position of the imaging device 250 on the vehicle 240. The imaging device 250 mounted on the vehicle 240 can also be referred to as an in-vehicle camera and can be installed in various locations on the vehicle 240. For example, the first imaging device 250a may be disposed on or near the front bumper as a camera for monitoring the front of the vehicle 240 while the vehicle 240 is traveling. The second imaging device 250b for monitoring the front may be disposed near an inner rearview mirror inside the vehicle 240. The third imaging device 250c may be disposed on the dashboard or in the instrument panel as a camera for monitoring the driver's driving status. The fourth imaging device 250d may be installed at the rear of the vehicle 240 to monitor the rear of the vehicle 240. The imaging devices 250a and 250b can be called front cameras. The third imaging device 250c can be called an in-camera. The fourth imaging device 250d can be called a rear camera. The imaging device 250 is not limited to these, and can include imaging devices installed in various positions, such as a left side camera that captures images of the left rear side and a right side camera that captures images of the right rear side.

[0049] An image signal of an image captured by the imaging device 250 may be output to an information processing device 242 and / or a display device 243 in the vehicle 240. The information processing device 242 and the display device 243, together with the imaging device 250, constitute an in-vehicle system. The information processing device 242 in the vehicle 240 includes a device that processes the image signal acquired by the imaging device 250, recognizes the image, and assists the driver in driving. Examples of the information processing device 242 include, but are not limited to, a navigation system, a collision damage mitigation braking system, a vehicle-to-vehicle distance control system, and a lane departure warning system. The display device 243 displays the image processed and output by the information processing device 242, but can also receive an image signal directly from the imaging device 250. The display device 243 may be, but is not limited to, a liquid crystal display (LCD), an organic electroluminescence (EL) display, or an inorganic EL display. The display device 243 can display to the driver (can output information to the occupants) an image signal output from an imaging device 250 that captures an image from a position that is difficult for the driver to see, such as a rear camera.

[0050] Fig. 9 shows the configuration of an imaging device that constitutes the in-vehicle system shown in Fig. 8. As shown in the figure, an imaging device 250 according to the embodiment includes a control unit 252, a storage unit 254, and the camera module 300 shown in Fig. 5 described above.

[0051] The control unit 252 controls the camera module 300 and processes the electrical signals output from the image sensor 304 of the camera module 300. The control unit 252 may be configured as, for example, a processor. The control unit 252 may also include one or more processors. The processor may include a general-purpose processor that loads a specific program to execute a specific function, and a dedicated processor specialized for a specific process. The dedicated processor may include an application-specific integrated circuit (IC). An application-specific IC is also called an application-specific integrated circuit (ASIC). The processor may include a programmable logic device. A programmable logic device is also called a programmable logic device (PLD). A PLD may include a field-programmable gate array (FPGA). The control unit 252 may be either a system-on-a-chip (SoC) or a system-in-a-package (SiP) in which one or more processors work together.

[0052] The storage unit 254 stores various information or parameters related to the operation of the imaging device 250. The storage unit 254 may be configured with, for example, a semiconductor memory or the like. The storage unit 254 may function as a work memory for the control unit 252. The storage unit 254 may store captured images. The storage unit 254 may store various parameters and the like that are used by the control unit 252 to perform detection processing based on the captured images. The storage unit 254 may be included in the control unit 252.

[0053] As described above, the camera module 300 captures an image of a subject formed through the lens unit 11 with the image sensor 304 and outputs the captured image. The image captured by the camera module 300 is also referred to as a captured image.

[0054] The imaging element 304 may be configured, for example, as a complementary metal oxide semiconductor (CMOS) image sensor or a charge coupled device (CCD). The imaging element 304 has an imaging surface on which multiple pixels are arranged. Each pixel outputs a signal specified by a current or voltage according to the amount of incident light. The signal output by each pixel is also referred to as imaging data.

[0055] The imaging data may be read by the camera module 300 for all pixels and captured by the control unit 252 as a captured image. A captured image read by all pixels is also referred to as a maximum captured image. The imaging data may be read by the camera module 300 for some pixels and captured as a captured image. In other words, the imaging data may be read from pixels in a predetermined capture range. The imaging data read from pixels in the predetermined capture range may be captured as a captured image. The predetermined capture range may be set by the control unit 252. The camera module 300 may acquire the predetermined capture range from the control unit 252. The imaging element 304 may capture an image of a predetermined capture range from the subject image formed via the lens unit 11.

[0056] The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, the shapes of the lenses, lens barrels, etc. are not limited to those of the above-described embodiments. Furthermore, without departing from the spirit of the present invention, some or all of the above-described embodiments may be combined, or part of the configuration of one of the above-described embodiments may be omitted.

[0057] REFERENCE SIGNS LIST 11 lens unit 12 lens barrel 13 first lens 14 second lens 26 sealing member 40 heater 50, 51, 52, 53, 54 heater device 50d, 53a, 54a opening 300 camera module 240 vehicle (moving body) L lens group O optical axis

Claims

1. A lens unit comprising a plurality of lenses arranged along an optical axis, a lens barrel that houses and holds the plurality of lenses, a first lens located closest to the object, a second lens adjacent to the first lens in the optical axis direction, and a heater disposed between the first lens and the second lens and capable of heating the first lens, further comprising a heater device that houses the heater, the heater being inserted between the first lens and the second lens while housed in the heater device.

2. The lens unit according to claim 1, further comprising a seal member for sealing between the first lens and the lens barrel, and the outer periphery of the heater device is located directly below the image side of the seal member.

3. The lens unit according to claim 1, wherein the heater device has an opening on a surface facing the object side through which the heater is exposed.

4. A camera module comprising the lens unit according to any one of claims 1 to 3, and an image sensor that converts light focused through the lens group of the lens unit into an electrical signal.

5. An imaging system comprising: an imaging device having a camera module as claimed in claim 4; a control unit for controlling said camera module and processing electrical signals output from the imaging element of said camera module; a processing device for processing image signals acquired by said imaging device; and a display device for displaying images processed and output by said processing device.

6. A vehicle equipped with the imaging system according to claim 5, wherein information is output to a passenger by the display device.

Images