Patent Description:
The present disclosure relates to a method of bonding, a lens, an optical assembly, a camera device and a moving body.

In a vehicle-mounted camera device, and the like, optical members such as a lens and an infrared cut filter are fixed to a holder that holds the optical members. An adhesive may be used to bond an optical member and a holder to each other (see, for example, Patent Literature <NUM> (PTL1) and Patent Literature <NUM> (PTL <NUM>)). Further, unused areas of the optical member that are not used optically may be black painted with antireflection paint (see, for example, Patent Literature <NUM> (PTL3)). <CIT> discloses a lens barrel comprising: a first lens; and a lens frame which holds the first lens. The lens frame comprises: a barrel plate which contacts with the first lens to regulate the position of the first lens in a thrust direction; and a through hole which is arranged from outside of the lens frame to the barrel plate to apply an adhesive agent. Ultraviolet rays are applied from an ultraviolet irradiation device to the adhesive agent to harden. <CIT> discloses a lens array that has a plurality of lens parts, and a substrate part by which the plurality of the lens parts are integrally connected to each other. This lens array includes: a groove formed in an area excluding a portion intersecting with an optical axis of the lens part; a light-shielding material filled into the groove; and a stepped bank formed in the boundary between the lens surface of the lens part and the groove. <CIT> discloses a method for manufacturing the lens unit can inexpensively mass-produce a lens unit having excellent optical characteristics, because an adhesive injected between two lens array plates is developed between surfaces having a space Δ2 using a capillary phenomenon, but is not developed between optical surfaces having a space Δ1 larger than the space Δ2.

According to the present disclosure, a method of bonding according to claim <NUM>, an optical assembly according to claim <NUM>, a camera device according to claim <NUM>, and a moving body according to claim <NUM> are provided. A further embodiment is defined in dependent claim <NUM>.

Adhesion and black painted treatment to an optical member such as a lens and an infrared cut filter preferably have high adhesion and are hard to peel off. Further, it is not easy to dispose a liquid material such as an adhesive and an antireflection paint on an optical member in a desired shape. Such liquid materials may move before they solidify and protrude from their intended position. If a groove is provided in the optical member or the holder to allow the liquid to escape, the shape of the optical member or the holder will be complicated. Further, liquid materials applied to undesired areas may come off after their solidification. If an adhesive or an antireflection paint pee peels off inside a housing of the camera device, the performance of the optical system of the camera device may be deteriorated.

A method of bonding, a lens, an optical assembly, a camera device and a moving body according to the present disclosure change the contact characteristics of a surface of at least one of an optical member and a holder at least partially. The contact characteristics include wettability and slipperiness. Thus, the above described various problems regarding bonding between the holder and the optical member in the camera device can be improved.

Before describing an embodiment of the present disclosure, the wettability and the slipperiness, which are the premise of the present disclosure, will be described.

Wettability represents the affinity between a solid surface and a liquid. When the liquid is water, the wettability is also referred to as hydrophilic or hydrophobic. The wettability is generally evaluated using a contact angle θ as an index. As illustrated in <FIG>, the contact angle θ is an angle formed by the surface of a droplet <NUM> and the surface of a solid <NUM> when the droplet <NUM> is disposed on the surface of the solid <NUM>. It is said that the smaller the contact angle θ, the better the wettability, and the larger the contact angle θ, the poorer the wettability. If the wettability is good, the droplet <NUM> spreads widely on the surface of the solid <NUM>. In general, when the contact angle θ is smaller than <NUM> degrees, the wettability is considered to be good, and when the contact angle θ is greater than <NUM> degrees, the wettability is considered to be poor. In the present disclosure, the contact angle θ is measured by a measuring machine typified by a dynamic contact angle measuring machine manufactured by First Ten Angstroms Inc. under the condition of dropping <NUM>µl of liquid onto a solid surface.

Slipperiness represents the removal performance of the droplet <NUM> on the surface of the solid <NUM>. As illustrated in <FIG>, when the droplet <NUM> is attached onto the horizontal surface of the solid <NUM> and the surface of the solid <NUM> is gradually tilted, the droplet <NUM> starts sliding downward at a certain tilt angle. The tilt angle at this time is referred to as a sliding angle α. In general, the slipperiness is evaluated using the sliding angle α as an index. When evaluating the removal performance of the droplet <NUM> using the sliding angle α, it is necessary to set predetermined conditions for the amount of liquid. In the present disclosure, the sliding angle is measured by a measuring machine typified by a dynamic contact angle measuring machine made by First Ten Angstroms Inc. under the condition of dropping <NUM> to <NUM>µl of liquid on the solid surface.

An embodiment of the present disclosure will be described with reference to the drawings below. The drawings used in the following description are schematic. The dimensional ratios on the drawings do not always match the actual ones.

The holding mechanism of a camera device <NUM> will be described with reference to <FIG>. As illustrated in <FIG>, the camera device <NUM> includes a lens <NUM>, a holder <NUM>, an O-ring <NUM> and an imaging circuit <NUM>. The area surrounded by the dashed-dotted line illustrated in <FIG> is enlarged and displayed in <FIG>. The holding mechanism can be rephrased as an optical assembly or can be included in an optical assembly of the camera device <NUM>.

The lens <NUM> is an optical member configured to form an object image on an image sensor of an imaging circuit <NUM>. The lens <NUM> is not limited to one lens, and may be composed of a plurality of lenses. <FIG> is a view of the lens <NUM> viewed from the image sensor side. Hereinafter the image sensor side is appropriately referred to as an "image side. " The central portion of the lens <NUM> is an optical use area 11a through which light rays involved in imaging pass. The outer periphery of the lens <NUM>, which is not included in the optical use area 11a, is an unused area through which light lays involved in imaging do not pass.

The image side of the outer periphery of the lens <NUM> is a flat joint surface S. A black antireflection paint <NUM> is applied to the joint surface S so as to circle the optical use area 11a. The antireflection paint <NUM> is applied to reduce phenomena such as ghost or flare caused when the unnecessary light incident from the lens <NUM> is reflected inside the camera device <NUM>.

Moreover, on a part of this joint surface S, a narrow annular sliding treatment area <NUM>, to which the antireflection paint <NUM> is not applied, is formed, in the area where the antireflection paint <NUM> is applied, so as to circle the optical use area 11a. The sliding treatment area <NUM> is a surface-treated area in which the sliding angle of the antireflection paint in a liquid state before solidifying to the lens <NUM> is less than <NUM> degrees.

In the present application, the surface treatment includes surface coating and surface modification. The surface treatment can be applied onto a coating such as an existing antireflection film. In the present application, the state in which the surface treatment is applied includes having a coating layer on the surface and having a surface modification layer. These layers may also be referred to as surface treatment layers. It is known that, when the solid surface has a structure of a predetermined shape, the slipperiness of the solid surface increases. Thus, as a treatment of adjusting the sliding angle with the antireflection paint, surface modification can be applied to the surface of the lens <NUM> to form a structure of a predetermined shape.

Instead of the sliding treatment area <NUM>, the joint surface S may be subjected to surface treatment that reduces wettability in which the contact angle of the antireflection paint in a liquid state before solidification exceeds a predetermined value. The surface treatment that reduces wettability includes coating the surface with a material with poor wettability. As a material with poor wettability with respect to water or the like, a fluorine compound with a trifluoromethyl group, a silicone resin in which a hydrophobic methyl group is oriented, or the like can be used. Furthermore, when the solid surface has a fine uneven structure, it is known that the surface with good wettability will have better wettability. Further, it is known that the surface with poor wettability will have poorer wettability. Thus, surface modification that produces a fine uneven structure is applied to a material with poor wettability so as to form a surface with a particularly poor wettability having a contact angle of more than <NUM> degrees. As a method of generating a fine uneven structure, a method of forming a fractal structure surface by self-organization, a method by laser ablation, a method by microwave plasma CVD method, a method by etching with use of a corrosive fluid, etc. are known.

The holder <NUM> is a member that holds the lens <NUM>. The holder <NUM> includes, for example, a lens holding ring 12a and a lens barrel 12b. The lens holding ring 12a can be screwed to the lens barrel 12b. The lens <NUM> can be held with its outer periphery sandwiched between the lens holding ring 12a and the lens barrel 12b. At that time, the O-ring <NUM> is disposed between the joint surface S of the lens <NUM> and the lens barrel 12b. A groove that receives the O-ring <NUM> is formed, for example, in the surface of the lens barrel 12b facing the joint surface S. In this manner, the O-ring <NUM> is positioned. The inner part of the lens barrel 12b along the optical axis of the lens <NUM> is hollow and can house the imaging circuit <NUM>. Other optical elements such as an infrared cut filter and a diaphragm may be disposed between the lens <NUM> and the imaging circuit <NUM>.

The O-ring <NUM> is disposed between the joint surface S of the lens <NUM> and the lens barrel 12b so as to circle the outside of the optical path of an image captured by the camera device <NUM>. The O-ring <NUM> is provided to seal the space in the lens barrel 12b in which the imaging circuit <NUM> is housed. The O-ring <NUM> comes in contact with the sliding treatment area <NUM> of the lens <NUM> to which the antireflection paint <NUM> is not applied. As a result, the lens <NUM> and the O-ring <NUM> are closely attached to each other, and the waterproof property in the lens barrel 12b is improved. If the antireflection paint <NUM> is applied to the surface of the lens <NUM> with which the O-ring <NUM> comes in contact, the adhesion between the lens <NUM> and the O-ring <NUM> will be reduced when the antireflection paint <NUM> peels off during manufacture or due to change over time. Thus the waterproof property may not be ensured.

The width of the O-ring <NUM> in contact with the joint surface S of the lens <NUM> when the lens <NUM> and the holder <NUM> are bonded to each other can be set to be substantially the same as the width of the annular sliding treatment area <NUM>. Here, substantially the same width means a width in which an error is less than <NUM>% with respect to the width of the sliding treatment area <NUM>. When the O-ring <NUM> is black, high adhesion can be obtained between the O-ring <NUM> and the lens <NUM> by making the sliding treatment area <NUM> and the width of the O-ring <NUM> in contact with the joint surface S substantially the same. Moreover, since the entire joint surface S is covered with a black area that does not transmit light, the same effect of reducing ghosts and flares as when the entire joint surface S is black painted can be obtained.

The imaging circuit <NUM> includes an image sensor. The image sensor has a plurality of pixels arranged in two dimensions. The image sensor may include, for example, a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor. The imaging circuit <NUM> converts an object image formed by the image sensor into an electric signal to generate an image, and outputs the image to outside the camera device <NUM>.

Next, a method of bonding the lens <NUM> to the holder <NUM> according to the first embodiment will be described with reference to <FIG>.

First, on the joint surface S of the lens <NUM> before the antireflection paint <NUM> is applied, surface treatment that enhances the slipperiness of the antireflection paint <NUM> is applied to the annular area corresponding to the position and the thickness of the O-ring <NUM> (step S101). The area where this surface treatment is applied is referred to as the sliding treatment area <NUM>. The sliding angle of the antireflection paint <NUM> in a liquid state in the sliding treatment area <NUM> is less than <NUM> degrees.

Next, the antireflection paint <NUM> in a liquid state is applied to the joint surface S (step S102). As the antireflection paint <NUM>, various commercially available black paints for optics can be used. After the antireflection paint <NUM> is applied, the joint surface S is tilted from the horizontal direction to slide the antireflection paint <NUM> in a liquid state located on the sliding treatment area <NUM> (step S103). Therefore, the antireflection paint <NUM> dries and solidifies on the joint surface S other than the sliding treatment area <NUM>.

After the antireflection paint <NUM> solidifies, the lens holding ring 12a is fitted into the lens barrel 12b with the O-ring <NUM> in contact with the sliding treatment area <NUM> onto which the antireflection paint <NUM> is not applied, and the lens <NUM> and the holder <NUM> are bonded to each other (step S104).

As described above, according to this embodiment, when the lens <NUM> and the holder <NUM> are bonded to each other, the O-ring <NUM> comes in contact with the joint surface S of the lens <NUM> without coming in contact with the antireflection paint <NUM>, and thus a high sealing property can be achieved in the space in the lens barrel 12b. Further, the risk that the antireflection paint <NUM> peels off inside the housing of the camera device <NUM> and the performance of the optical system of the camera device <NUM> is degraded can be reduced.

A holding mechanism <NUM> according to a second embodiment of the present disclosure will be described with reference to <FIG>. The holding mechanism <NUM> includes a lens <NUM>, which is an optical member, a holder <NUM>, and an adhesive <NUM> that bonds the lens <NUM> and the holder <NUM> to each other.

The lens <NUM> can have various shapes. The lens <NUM> is, for example, a plano-convex lens that is convex toward the object as illustrated in <FIG>. The convex surface and the flat surface of the lens <NUM> are separated by a predetermined distance in terms of outer periphery. The outer peripheral side 21a between the convex surface and the flat surface of the lens <NUM> is a cylindrical surface. The outer peripheral side 21a of the lens <NUM> is treated with a surface treatment that improves wettability in which the contact angle with the liquid adhesive <NUM> before solidification is smaller than the contact angle between the base material of the lens <NUM> and the liquid adhesive <NUM> before solidification. In other words, the outer peripheral side 21a of the lens <NUM> has better wettability to the adhesive <NUM> than the base material of the lens <NUM>. The base material of the lens means a material of the lens. The base material of the lens includes glass and resin.

The holder <NUM> has a circular ring shape with a hollow center 22a centered on the optical axis O of the lens <NUM>. The holder <NUM> is also provided with a circular stepped portion 22b that receives the lens <NUM> in the center, when viewed in the direction along the optical axis O. Furthermore, the holder <NUM> is provided with four adhesive recesses 22c toward the outside in the radial direction at positions displaced by <NUM> degrees in the circumferential direction of the circular step portion 22b. In each recess for adhesion 22c, the outer peripheral side 21a of the lens <NUM> is in contact with the adhesive <NUM>. It is to be noted that the number and the arrangement of the recesses for adhesion 22c are examples, and are not limited to the above example.

Each adhesive <NUM> is in contact with the outer peripheral side 21a of the lens <NUM> and the holder <NUM> in each of the four recesses for adhesion 22c. In this manner, the lens <NUM> is fixed to the holder <NUM>.

Next, a method of bonding the lens <NUM> to the holder <NUM> according to the second embodiment will be described with reference to <FIG>.

First, the outer peripheral side 21a of the lens <NUM> is subjected to surface treatment that improves the wettability of the adhesive <NUM> (step S201). The side surface subjected to surface treatment to improve the wettability can be the entire outer peripheral side 21a of the lens <NUM> or only the part to which the adhesive <NUM> is applied. This surface treatment makes the contact angle between the adhesive <NUM> in a liquid state and the surface-treated outer peripheral side 21a smaller than the contact angle between the adhesive <NUM> in a liquid state and the base material of the lens <NUM>. The contact angle between the adhesive <NUM> in a liquid state and the surface-treated outer peripheral side 21a may be less than <NUM> degrees.

The surface treatment that improves the wettability includes coating the surface with a material with good wettability. As a material with good wettability to water or the like, a titanium oxide film coating agent, a silicone resin in which a silanol group is oriented, or the like can be used. Furthermore, as described above, it is known that, when a solid surface has a fine uneven structure, a surface having good wettability has better wettability, and a surface having poor wettability has poorer wettability. Therefore, a surface having particularly good wettability with a contact angle of less than <NUM> degrees can be formed by applying surface modification that produces a fine uneven structure to the material having good wettability. In this embodiment, it is particularly advantageous that the surface treatment is surface modification.

Next, the lens <NUM> is received in the recess of the holder <NUM>, the four recesses for adhesion 22c are filled with the adhesive <NUM>, and the outer peripheral side 21a of the lens <NUM> and the holder <NUM> are bonded to each other (step S202). Since the outer peripheral side 21a of the lens <NUM> is surface-treated to improve the wettability to the adhesive <NUM>, it has high adhesion to the adhesive <NUM>. Therefore, the lens <NUM> and the holder <NUM> are firmly bonded to each other.

As described above, according to this embodiment, since the outer peripheral side 21a of the lens <NUM> is surface-treated to improve the wettability to the adhesive <NUM>, the lens <NUM> and the holder <NUM> are firmly bonded to each other via the adhesive <NUM>. As a result, the bonding strength between the lens <NUM> and the holder <NUM> is improved, and they are less likely to peel off.

A holding mechanism <NUM> according to a third embodiment will be described with reference to <FIG> is the holding mechanism <NUM> disposed inside the camera device as viewed from the direction along the optical axis of the camera device. The holding mechanism <NUM> includes an infrared cut filter <NUM> (optical member), a holder <NUM> and an adhesive <NUM>. In the holding mechanism <NUM>, the infrared cut filter <NUM> is held by the holder <NUM> in the camera device.

The infrared cut filter <NUM> does not transmit infrared rays and transmits visible light. The infrared cut filter <NUM> may include a dielectric multilayer film formed on a glass substrate. Inside the camera device, the infrared cut filter <NUM> is disposed in front of the lens side of the image sensor.

The holder <NUM> is a member that holds the infrared cut filter <NUM> to the housing of the camera device. The holder <NUM> may be attached to the housing of the camera device. The holder <NUM> may have a plate-like portion having a circular opening through which light rays from the object pass. In the example illustrated in <FIG>, the holder <NUM> is illustrated as a square plate member.

The adhesive <NUM> bonds the infrared cut filter <NUM> and the holder <NUM> to each other. The adhesive <NUM> may be disposed near the four corners of the square holder <NUM>. At the time of bonding, the adhesive <NUM> in a liquid state is applied to the vicinity of the four corners of the infrared cut filter <NUM>. The adhesive <NUM> in a liquid state spreads by bringing the infrared cut filter <NUM> and the holder <NUM> into close contact with each other.

The portion that overlaps the circular opening of the holder <NUM> when the infrared cut filter <NUM> is bonded to the holder <NUM> is referred to as the optical use area <NUM> of the infrared cut filter <NUM>. Before the infrared cut filter <NUM> is bonded to the holder <NUM>, the optical use area <NUM> is surface treated to reduce the wettability to the adhesive <NUM> in a liquid state before solidification. That is, the wettability of the optical use area <NUM> with respect to the adhesive <NUM> in a liquid state is worse than that of other areas of the infrared cut filter <NUM> with respect to the adhesive <NUM> in a liquid state. Therefore, the adhesive <NUM> in a liquid state is repelled with respect to the optical use area <NUM> and does not protrude into the optical use area <NUM>. As a result, after bonding, the adhesive <NUM> does not protrude into the optical use area <NUM>.

<FIG> illustrates, for comparison, an example in which the optical use area <NUM> of the infrared cut filter <NUM> is not subjected to surface treatment that reduces the wettability. In this case, a part of the adhesive <NUM> (for example, the lower right part in <FIG>) may protrude into the optical use area <NUM> of the infrared cut filter <NUM>. If the adhesive <NUM> protrudes into the optical use area <NUM>, the adhesive <NUM> may appear in the image of the camera device. Thus, the holding mechanism <NUM> in which the adhesive <NUM> protrudes into the optical use area <NUM> can be defective.

Next, a method of bonding the infrared cut filter <NUM> to the holder <NUM> according to the third embodiment will be described with reference to <FIG>.

First, a surface treatment that reduces the wettability of the adhesive <NUM> in a liquid state is applied to the optical use area <NUM> of the infrared cut filter <NUM> (step S301). It is preferable that the surface treatment that reduces the wettability has almost no effect on the transmission of visible light. The surface treatment that reduces the wettability makes the contact angle between the adhesive <NUM> in a liquid state and the surface-treated optical use area <NUM> larger than the contact angle between the adhesive <NUM> in a liquid state and the base material of the infrared cut filter <NUM>. For example, the contact angle between the adhesive <NUM> in a liquid state and the surface-treated optical use area <NUM> can be an angle exceeding <NUM> degrees.

Next, the adhesive <NUM> is applied to the four corners outside the optical use area <NUM> of the infrared cut filter <NUM>, and the infrared cut filter <NUM> and the holder <NUM> are bonded to each other (step S302). The adhesive <NUM> spreads between the infrared cut filter <NUM> and the holder <NUM>. However, the spread of this adhesive <NUM> is regulated by the surface-treated part of the infrared cut filter <NUM>, and solidifies without spreading to the optical use area <NUM>.

As described above, in the holding mechanism <NUM> according to this embodiment illustrated in <FIG>, since the adhesive <NUM> does not protrude into the optical use area <NUM>, a good image can be captured when adopted to a camera device. Further, it is not necessary to provide the optical member or the holder with a complicated shape such as a groove shape for allowing liquid to escape to prevent the adhesive <NUM> from protruding. Thus the holding mechanism <NUM> can be formed easily.

A schematic configuration of a camera device <NUM> including a lens provided with a holding mechanism according to a fourth embodiment will be described with reference to <FIG>. The camera device <NUM> includes a lens <NUM>, which is an optical member, a lens holding ring <NUM>, a lens barrel <NUM>, an imaging circuit <NUM> and an infrared cut filter <NUM>.

The lens <NUM> forms an image of the object on the image sensor included in the imaging circuit <NUM>. The lens holding ring <NUM> and the lens barrel <NUM> serve as a holder that holds the lens <NUM>. That is, the lens <NUM>, the lens holding ring <NUM> and the lens barrel <NUM> constitute a holding mechanism. The holder that holds the lens <NUM> is not limited to one that includes the lens holding ring <NUM> and the lens barrel <NUM>, but can be configured in various manners. For example, the lens <NUM> can be held in a single lens barrel without providing the lens holding ring <NUM>. The imaging circuit <NUM> including an image sensor and the infrared cut filter <NUM> are housed in the lens barrel <NUM>. The imaging circuit <NUM> acquires, by an image sensor, an object image by a visible light whose wavelength in the infrared area is cut by the infrared cut filter <NUM>, converts it into an electric signal and outputs to the outside.

The lens <NUM> can be, for example, a positive meniscus lens as illustrated in <FIG>, for example. However, the shape of the lens <NUM> is not limited thereto. The lens <NUM> has a first surface 41a on the object side including the optical use area and a second surface 41b on the image side. The lens <NUM> further includes an unused area 41c, which is not optically used, on the outer periphery. The unused area 41c may include a flat edge portion 41d protruding outside the outer periphery of the lens <NUM>. At least a part of the unused area 41c is surface-treated to improve the wettability to the antireflection paint in a liquid state. The portion subjected to this surface treatment is referred to as a surface treated area <NUM>. In the example of <FIG>, the surface treated area <NUM> is a flat surface outside the second surface 41b when viewed from the optical axis O of the lens <NUM>.

A black-painted portion to which the antireflection paint is applied is formed on the above described surface treated area <NUM> of the lens <NUM>. As described above, the surface treated area <NUM> has good wettability to the antireflection paint in a liquid state before solidification. Therefore, the antireflection paint closely adheres to the surface treated area <NUM>, and peeling thereof is unlikely to occur.

Next, a method of bonding the lens <NUM> to the lens holding ring <NUM> and the lens barrel <NUM> (holder) according to the fourth embodiment will be described with reference to <FIG>.

First, a surface treatment that improves the wettability of the antireflection paint is applied to the surface treated area <NUM> outside the second surface 41b, which is a part of the optical use area of the lens <NUM> (step S401). The surface treatment that improves the wettability of the antireflection paint makes the contact angle between the antireflection paint in a liquid state and the surface-treated area <NUM> smaller than the contact angle between the antireflection paint in a liquid state and the base material of the lens <NUM>. The contact angle between the antireflection paint in a liquid state and the surface-treated area <NUM> can be less than <NUM> degrees.

Next, the antireflection paint in a liquid state is applied to the surface treated area <NUM> (step S402). Since the surface treated area <NUM> has good wettability with respect to the antireflection paint in a liquid state, the adhesion between the antireflection paint and the surface treated area <NUM> increases even after the antireflection paint solidifies. In this manner, the antireflection paint layer is formed on the surface treatment layer.

After the antireflection paint dries and solidifies, the lens <NUM> and the holder are bonded to each other (step S403). For example, the lens <NUM> is fixed with its outer periphery sandwiched between the lens holding ring <NUM> and the lens barrel <NUM>. In this manner, the lens <NUM> is positioned in the camera device <NUM>.

As described above, in the lens <NUM> according to this embodiment, since the surface to which the antireflection paint is applied is subjected to surface treatment that improves the wettability to the antireflection paint in advance, the antireflection paint is hard to peel off. Furthermore, since the holding mechanism of the lens <NUM> and the camera device <NUM> incorporating this lens <NUM> are less likely to cause peeling off of the antireflection paint from the lens <NUM>, good optical performance can be continuously maintained.

The camera devices <NUM> and <NUM> according to the present disclosure may be mounted on a moving body. The holding mechanisms <NUM> and <NUM> of the optical member according to the present disclosure may be provided to the camera device mounted on the moving body. The moving body in the present disclosure may include, for example, vehicles, ships, aircrafts and the like. The vehicles according to the present disclosure include automobiles, track vehicles, industrial vehicles and vehicles for life, but are not limited thereto. For example, vehicles may include airplanes running on runway. The automobiles may include, for example, passenger cars, trucks, buses, two-wheel vehicles, trolleybuses and the like, but are not limited thereto, and may include other vehicles running on roads. Track vehicles may include locomotives, freight cars, passenger cars, trams, guided track railroads, ropeways, cable cars, maglev trains, and monorails, but are not limited thereto, and may include other vehicles traveling along the track. Industrial vehicles may include, for example, agricultural and construction industrial vehicles and the like. Industrial vehicles may include, for example, forklifts, golf carts, and the like, but are not limited thereto. Agricultural industrial vehicles may include, for example, tractors, tillers, transplanters, binders, combines, lawn mowers and the like, but are not limited thereto. Construction industrial vehicles may include, for example, bulldozers, scrapers, loading shovels, crane vehicles, dump trucks, road rollers and the like, but are not limited thereto. Vehicles for life may include bicycles, wheelchairs, prams, wheelbarrows, and electric standing two-wheeled vehicles, but are not limited thereto. Vehicle power engines may include diesel engines, gasoline engines, internal combustion engines including hydrogen engines, and electric engines including motors, but are not limited thereto. Vehicles may include human-powered vehicles. Vehicle classification is not limited to the above described examples. For example, automobiles may include industrial vehicles that can travel on the road, and same vehicle may be included in some categories.

<FIG> illustrates the position where a camera device <NUM> mounted on a moving body <NUM>, which is an automobile, is installed. The camera device <NUM> can be installed at any one or more positions including a vehicle rear portion <NUM>, a vehicle front portion <NUM>, and a vehicle side portion <NUM>. The vehicle rear portion <NUM> is, for example, near a rear bumper. The vehicle front portion <NUM> is, for example, near a front grille and a front bumper. The vehicle side portion <NUM> is, for example, near a side mirror. The camera device <NUM> disposed at the above positions can be referred to as a rear camera, a front camera, and a side camera, respectively. The rear camera, the front camera, and the side camera can capture the rear, front, and side areas, respectively. In many cases, the camera device <NUM> is disposed with the optical axis tilted toward the road surface than the horizontal direction. Each of the camera devices <NUM> enables wide-angle shooting, and the camera devices <NUM> disposed at a plurality of positions may be combined to capture the entire circumference of the vehicle.

Claim 1:
A method of bonding an optical member (<NUM>) and a holder (<NUM>) that holds the optical member (<NUM>), comprising:
applying a surface treatment (S101) to at least a part of a surface (S) of at least one of the optical member (<NUM>) and the holder (<NUM>) to change contact characteristics of the at least the part of the surface (S) with a liquid; and
bonding the optical member (<NUM>) and the holder (<NUM>) to each other (S104) after applying the surface treatment to the at least a part of the surface (S) of the at least one of the optical member (<NUM>) and the holder (<NUM>)
wherein the method further comprises, after the applying the surface treatment:
applying (S102) an antireflection paint (<NUM>) in a liquid state to the at least the part of the surface (S); characterized by
slipping (S103) the antireflection paint (<NUM>) applied to a predetermined surface-treated portion of the at least the part of the surface (S);
wherein the predetermined surface-treated portion includes a sliding angle (α) of the antireflection paint (<NUM>) in a liquid state that is less than <NUM> degrees, so as to circle an optically used area (11a) of the optical member (<NUM>), and
wherein the optical member (<NUM>) and the holder (<NUM>) are bonded to each other with an O-ring (<NUM>) therebetween, so that the O-ring (<NUM>) comes in contact with the predetermined surface-treated portion.