JP2009157194A - Optical apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent degradation of image quality when an optical apparatus (onboard camera 11 or the like) is used outdoors by smoothly draining rainwater or the like around an optical member (lens 21 or the like). <P>SOLUTION: This onboard camera 11 comprises the lens 21 held with its surface exposed to the outside air, and a lens barrel 31 for holding the periphery of the lens 21. The lens barrel 31 has a slit 33 extending outward from an inner end for holding the lens 21. The slit 33 drains water-drop such as raindrop adhering to the periphery of the lens 21 out of the optical effective diameter. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical device that includes an optical member that is held in a state where the surface is exposed to the outside air, and a holding member that holds the peripheral edge of the optical member. More specifically, the present invention relates to a technique that can prevent water droplets from being reflected in an effective field angle region of an optical element member due to water droplets such as raindrops adhering and staying on the peripheral edge of the optical member.

  2. Description of the Related Art Conventionally, as an optical device used outdoors, for example, an in-vehicle camera, a monitoring camera, and the like are known. And in-vehicle cameras, surveillance cameras, etc. are optical members (for example, a lens, a light transmissive optical filter disposed on the front side of the lens, a hood, etc.) held in a state where the surface is exposed to the outside air when it rains. Rainwater may adhere to the surface as water droplets. Then, if the adhering water droplet is within the optically effective angle of view, the image of the vehicle-mounted camera or the surveillance camera is distorted or the image becomes unclear due to the influence of the reflection. If the area to be imaged is distorted, the sense of distance to the object is impaired.

Therefore, a technique that can prevent such adhesion of water droplets is disclosed. In other words, the surface of the optical member is coated with a hydrophilic film such as porous silica so that rainwater does not accumulate on the surface as water droplets (see, for example, Patent Document 1 and Patent Document 2).
JP-A-8-11631 JP 10-36144 A

FIG. 7 is a perspective view and a cross-sectional view showing such a conventional in-vehicle camera 111.
As shown in FIG. 7A, the in-vehicle camera 111 is one in which the peripheral portion of the lens 121 is held by a lens barrel 131. A lens barrel 131 holding the lens 121 is accommodated in the camera housing 141. Further, as shown in FIG. 7B, the in-vehicle camera 111 is installed such that the depression angle is about 45 °.

  When such a vehicle-mounted camera 111 is used in rainy weather, rainwater adheres to the surface of the hemispherical lens 121 as water droplets. When the amount of water drops reaches a certain level due to the effect of the film coated on the surface of the lens 121 and the gravity acting on the water drops due to the inclination of the optical axis of the lens 121, the water drops do not stay on the surface of the lens 121. Flows down along the surface of the. Then, as shown in FIG. 7B, the water droplets that have flowed down accumulate at the lower edge of the lens 121 and become a water pool. If the surface of the lens 121 is coated with a hydrophilic coating, water droplets flow down to the outer peripheral portion below the lens 121, but the water droplets that have lost their escape are within the range where the forces due to their own weight are balanced. Will stay.

  Therefore, in the in-vehicle camera 111 shown in FIG. 7 using the technique of Patent Document 1 or Patent Document 2 described above, since water droplets are only flowed to the lower edge portion of the lens 121, water droplets remain attached to the lower edge portion. It becomes. As a result, the image projected on the monitor inside the vehicle is refracted by a part of the optical path due to water droplets, and the image formation point is shifted, and the image becomes unclear. In addition, the image is distorted and the field of view is shifted without growing into large droplets. In addition, when the raindrops and the remaining water droplets evaporate, inorganic salts such as calcium contained in the water droplets are precipitated in white, so that the image quality deteriorates even after raining.

For this reason, a technique is known in which rainwater or the like is not collected at the lower edge of the lens 121. That is, a pipe is arranged on the lower surface of the lens barrel 131 that holds the lens 121 coated with a hydrophilic film, and rainwater or the like collected on the peripheral edge of the lens 121 is sucked from the opening of the pipe and drained. (For example, refer to Patent Document 3).
JP 2006-313312 A

  However, since the technique disclosed in Patent Document 3 requires a pipe to be disposed on the lower surface of the lens barrel 131, the in-vehicle camera 111 is increased in size. The lens barrel 131 holding the lens 121 is accommodated in the camera casing 141. However, if a pipe is disposed on the lower surface of the lens barrel 131, it is difficult to accommodate in the camera casing 141. Furthermore, since there is a certain distance between the peripheral edge of the lens 121 and the opening of the pipe, rainwater collected at the peripheral edge of the lens 121 is not smoothly sucked into the pipe, and the drainage performance of water drops is also improved. There's a problem.

  Therefore, the problem to be solved by the present invention is to smoothly drain rainwater and the like collected at the peripheral portion of the optical member (lens 121, etc.) without arranging a pipe on the lower surface of the holding member (lens barrel 131, etc.). It is possible to prevent the deterioration of the video quality when the optical device (the vehicle-mounted camera 111 or the like) is used outdoors.

The present invention solves the above-described problems by the following means.
Invention of Claim 1 of this invention is an optical apparatus provided with the optical member hold | maintained in the state where the surface was exposed to external air, and the holding member for hold | maintaining the peripheral part of the said optical member, The holding member is formed with a water conduit that extends outward from the inner end portion that holds the optical member, and the water conduit is configured to remove water droplets such as raindrops attached to the peripheral portion of the optical member with an optical effective diameter. Characterized by escape to the outside.

(Function)
According to the first aspect of the present invention, the holding member is formed with a water conduit extending outward from the inner end holding the optical member. And this water conduit allows water droplets, such as a raindrop adhering to the peripheral part of an optical member, to escape outside an optical effective diameter. Therefore, water droplets such as raindrops can be drained directly from the peripheral portion of the optical member without arranging a pipe as in the technique of Patent Document 3 described above.

  According to said invention, water droplets, such as a raindrop adhering to an optical member, can be directly drained from the peripheral part by the water conduit formed in the holding member. Therefore, the optical device does not become large or complicated. In addition, since rainwater or the like collected at the peripheral edge of the optical member is smoothly drained, it is possible to prevent deterioration in image quality when the optical device is used outdoors.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
In the following embodiments, as an optical device of the present invention, the in-vehicle camera 11 (first embodiment), the in-vehicle camera 12 (second embodiment), and the in-vehicle camera 13 (third embodiment) are taken as examples. Yes. The in-vehicle camera 11, the in-vehicle camera 12, and the in-vehicle camera 13 of each embodiment display a back view of the vehicle in the vehicle, and therefore, the garnish and the spoiler near the rear license plate are positioned below the horizontal direction. Installed.

FIG. 1 is a front view and a perspective view showing the in-vehicle camera 11 of the first embodiment.
As shown in FIG. 1, in the vehicle-mounted camera 11 of the first embodiment, the periphery of a hemispherical lens 21 (corresponding to an optical member in the present invention) corresponds to a lens barrel 31 (corresponding to a holding member in the present invention). )). The lens barrel 31 holding the lens 21 becomes a lens casing, and this lens casing is screwed into the camera casing 41 (corresponding to the casing in the present invention) and is accommodated in the camera casing 41. ing. However, the lens barrel 31 may be formed integrally with the camera casing 41.

  Here, the lens 21 may impart water repellency to the surface thereof, and water droplets such as raindrops may move to the outer peripheral side of the optical effective diameter by their own weight. In addition, for example, a two-layer film is coated with a photocatalyst film such as titanium oxide and a hydrophilic film such as porous silica, thereby imparting hydrophilicity to the surface of the lens 21, and water droplets such as raindrops are self-weighted. You may make it move to the outer peripheral side of an optical effective diameter. The lens 21 is held at the tip of the lens barrel 31 with such a surface exposed to the outside air. Hereinafter, a case where hydrophilicity is imparted to the surface of the lens 21 will be described. However, the effect of the present invention is not limited to the lens 21 having hydrophilicity.

  The lens barrel 31 has a cylindrical shape formed of a synthetic resin, and holds the lens 21 by applying heat to the lens frame 32 at the tip thereof to deform (heat caulking). The lens frame 32 (heat caulking portion) is not uniform in height, but has a plurality of slits 33 (water conduits in the present invention) extending radially outward from the inner end holding the lens 21 at regular intervals. The slits 33 allow water droplets such as raindrops adhering to the peripheral edge of the lens 21 to escape outside the optical effective diameter.

  In this way, the plurality of slits 33 are formed radially at regular intervals so that when the in-vehicle camera 11 is installed, at least one or more slits 33 are positioned on the lower edge side of the inclined lens 21. It is to make it. That is, the in-vehicle camera 11 is often installed near the rear garnish of the vehicle so that the depression angle is about 45 °. Further, when the lens case is screwed into the camera case 41, the position where the lens case stops due to the screwing rotation is not specified. Therefore, by forming a plurality of slits 33 in a radial pattern at a predetermined interval in advance, the lens 21 of the in-vehicle camera 11 installed with a depression angle of about 45 ° no matter where the lens housing stops at the screwing position. Any one of the slits 33 is surely positioned on the lower edge side.

  Further, each slit 33 does not necessarily have an uneven step, and in order to make the surface of the lens barrel 31 into a slit-like hydrophilic modification, the resin surface can be modified by making the resin surface partially hydrophilic by laser ablation. Then, a treatment agent for making the resin hydrophilic is applied onto the slits by tampo printing or the like to form a water conduit, and water droplets such as raindrops adhering to the periphery of the lens 21 can smoothly escape to each slit 33. Yes. Furthermore, the water conduit for releasing water droplets such as raindrops is not limited to the slit 33, but may be a step extending radially outward from the inner end of the lens barrel 31 that holds the lens 21. And it is preferable that an inner edge part is an acute angle shape, and a level | step difference is a shape from which a contact state with water droplets, such as a raindrop, becomes more than the contact angle of water.

FIG. 2 is a cross-sectional view illustrating the flow of water droplets in the in-vehicle camera 11 of the first embodiment.
FIG. 3 is a side view showing a water drop dropping experiment on a resin plane.
As shown in FIG. 2, the in-vehicle camera 11 is installed so that the depression angle is about 45 °. Therefore, the optical axis of the lens 21 is inclined downward from the horizontal direction. When the in-vehicle camera 11 is used in rainy weather, rainwater adheres to the surface of the lens 21 as water droplets. The water droplets do not stay on the surface of the hemispherical lens 21 due to the gravity acting on the water droplets due to the inclination of the optical axis of the lens 21, and flow down downward along the surface of the lens 21 as shown in FIG. .

  Here, the boundary portion between the lower edge portion of the lens 21 and the lens frame 32 holding the lens 21 is almost horizontal in the in-vehicle camera 11 installed with a depression angle of about 45 °. Therefore, the water droplets that have flowed down along the surface of the lens 21 are likely to accumulate at the lower edge of the lens 21 (near the boundary between the lens 21 and the lens frame 32). And if it becomes a puddle, a puddle will be reflected in the image | video of the vehicle-mounted camera 11 projected on the monitor in a vehicle, and the visibility of the back view of a car will worsen. In addition, when rain falls and the puddle dries, inorganic salts such as calcium contained in the rainwater precipitate white, which not only narrows the field of view of the back view but also degrades the quality of the image.

  However, in the in-vehicle camera 11 of the first embodiment, water drops that have flowed downward along the surface of the lens 21 do not collect on the lower edge portion of the lens 21, and the slit 33 located on the lower edge side of the lens 21 has a water guide channel. This acts to allow water droplets to escape outside the optical effective diameter. That is, as shown in FIG. 2B, the slit 33 located on the lower edge side of the lens 21 has a slightly higher inside for holding the lens 21 in the in-vehicle camera 11 installed with a depression angle of about 45 °. In this state, it is inclined downward toward the outside. Therefore, when a water droplet that has flowed down along the surface of the lens 21 contacts the slit 33 there, the contact area of the water droplet on the same plane is reduced, the surface tension is reduced, and a synergistic effect with gravity acting on the water droplet. As a result, water droplets escape from the lower edge of the lens 21 to the slit 33.

  The slit 33 is formed by subjecting the surface layer of the lens barrel 31 to hydrophilic treatment by a laser ablation method. Further, it is confirmed that the water droplet contact angle θ (see FIG. 2B and FIG. 3B) is reduced (improves hydrophilicity) due to the surface modification effect by the laser ablation method on the lens barrel 31. That is, on the resin surface subjected to surface modification by ablation with laser irradiation having energy capable of carbonizing the surface of the synthetic resin constituting the lens barrel 31, an untreated resin plane as shown in FIG. As shown in FIG. 3B, the water droplet contact angle θ with respect to the water droplet contact angle θ decreases to about 30 °. Furthermore, the drainage effect of water droplets with an oblique inclination angle is that when surface modification is performed by laser irradiation, drainage starts with the weight of about 0.3 ml of water droplets, whereas when laser irradiation is not performed. In this case, drainage will not be started until it becomes about 0.4 ml.

  The effect of the hydrophilic treatment of the resin surface by the laser ablation method depends on the ionization degree of the bond end of the resin by the irradiation light, and therefore has an irradiation light wavelength dependency and a resin material dependency. It is necessary to optimize the irradiation conditions for each resin to be implemented.

  From such experimental results, if the surface layer of the lens barrel 31 is subjected to hydrophilic treatment by laser ablation method to form the slit 33 which is a water conduit, in a state where it is mounted on an actual vehicle where raindrops continuously fall. It can be said that water droplets such as raindrops easily flow down to the slit 33.

  Accordingly, water droplets such as raindrops adhering to the peripheral portion of the lens 21 can smoothly escape by the slits 33 which are water conduits whose surfaces are modified by laser irradiation. Note that the water conduit is not limited to each of the slits 33 as described above, and the surface layer of the lens barrel 31 is formed by applying a hydrophilic treatment by locally applying or printing a hydrophilic treatment agent, or the surface layer of the lens barrel 31. By forming a step on the water droplets, the movement of water droplets from the peripheral edge of the lens 21 to the water conduit may be smooth.

  As described above, in the in-vehicle camera 11 of the first embodiment, the slit 33 serves as a water conduit for water droplets, and water is not collected on the lower edge portion of the lens 21 and is drained from the surface of the lens 21. No water droplets are reflected on the 11 images, and the image is not distorted by the water droplets. Moreover, the view of the back view is not narrowed or the quality of the video is not deteriorated by the inorganic salt which is dried and drops white.

FIG. 4 is a front view and a perspective view showing the in-vehicle camera 12 of the second embodiment.
As shown in FIG. 4, the in-vehicle camera 12 of the second embodiment is the one in which the peripheral portion of the lens 22 is held by a lens barrel 31, similarly to the in-vehicle camera 11 (see FIG. 1) of the first embodiment. is there. The lens 22 is held at the tip of the lens barrel 31 with the surface of the lens 22 exposed to the outside air.

  Moreover, the lens barrel 31 in the vehicle-mounted camera 12 of the second embodiment is the same as the vehicle-mounted camera 11 (see FIG. 1) of the first embodiment. That is, the lens barrel 31 has a cylindrical shape made of synthetic resin, and holds the lens 22 by applying heat to the lens frame 32 at the tip thereof to deform (thermal crimping). . The lens frame 32 (heat caulking portion) is formed with a plurality of slits 34 that extend radially outward from the inner end holding the lens 22 at regular intervals, and each slit 34 is a peripheral edge of the lens 22. This is a water conduit that allows water droplets such as raindrops attached to the part to escape outside the optical effective diameter.

  Furthermore, in the in-vehicle camera 12 of the second embodiment, the lens barrel 31 holding the lens 22 serves as a lens case. This lens case is the same as that of the in-vehicle camera 11 of the first embodiment (see FIG. 1). It is screwed into a camera housing 42 different from the camera housing 41 (see FIG. 1) and is accommodated in the camera housing 42. That is, unlike the camera casing 41, the camera casing 42 has a lower edge portion of the lens 22 when the in-vehicle camera 12 is installed near the rear garnish of the vehicle so that the depression angle is about 45 °. A plurality of concave grooves 43 (corresponding to the auxiliary water conduits in the present invention) are formed at positions on the side.

  Here, since a plurality of slits 34 are formed radially from the center of the lens barrel 31 at regular intervals, the lens housing stops at any position when the lens housing is screwed into the camera housing 42. Even so, one of the slits 34 is always positioned on the lower edge side of the lens 22. The concave groove 43 formed in the camera housing 42 corresponds to the slit 34 located on the lower edge side of the lens 22. Note that, as with the slit 34, a plurality of the concave grooves 43 can be formed radially from the center of the camera housing 42 at regular intervals.

FIG. 5 is a cross-sectional view illustrating the flow of water droplets in the in-vehicle camera 12 of the second embodiment.
As shown in FIG. 5, the in-vehicle camera 12 is installed so that the depression angle is about 45 °. Therefore, the optical axis of the lens 22 is inclined downward from the horizontal direction. When the in-vehicle camera 12 is used in rainy weather, rainwater adheres to the surface of the lens 22 as water droplets. The water droplets do not stay on the surface of the hemispherical lens 22 due to the gravity acting on the water droplets due to the inclination of the optical axis of the lens 22, but flow down downward along the surface of the lens 22 as shown in FIG. . That is, the surface of the lens 22 is not coated with a hydrophilic film. However, if water droplets adhering to the surface of the lens 22 become larger than a certain level, the lens 22 flows down due to gravity.

  The water droplets that have flowed down along the surface of the lens 22 in this way tend to collect on the lower edge of the lens 22 (near the boundary between the lens 22 and the lens frame 32), but are located on the lower edge side of the lens 22. The slit 34 to be used becomes a water conduit and allows water droplets to escape. That is, the slit 34 located on the lower edge portion side of the lens 22 is a state in which the inside holding the lens 22 is slightly high and is inclined downward toward the outside in the in-vehicle camera 12 installed with a depression angle of about 45 °. It has become. Therefore, when a water drop that has flowed down along the surface of the lens 22 contacts the slit 34 there, the contact area of the water drop on the same plane is reduced, the surface tension is reduced, and a synergistic effect with gravity acting on the water drop. As a result, water droplets escape from the lower edge of the lens 22 to the slit 34.

  Further, as shown in FIG. 5B, the water droplets that have escaped to the slit 34 enter the concave groove 43 formed on the extension line at a position corresponding to the slit 34. Therefore, in the vehicle-mounted camera 12 of the second embodiment, the slit 34 and the concave groove 43 serve as a water conduit for water droplets. That is, since the water droplets are drained from the surface of the lens 22 more effectively, the water droplets do not accumulate at the lower edge portion of the lens 22.

  Therefore, according to the vehicle-mounted camera 12 of 2nd Embodiment, it can prevent more reliably that a water droplet is reflected in the image | video of the vehicle-mounted camera 12, or a video is distorted by a water droplet. In addition, the view of the back view is not narrowed and the quality of the video is not deteriorated by inorganic salts such as calcium which are dried out from the water droplets.

FIG. 6 is a front view and a perspective view showing the in-vehicle camera 13 of the third embodiment.
As shown in FIG. 6, in the in-vehicle camera 13 of the third embodiment, the periphery of the lens 21 is held at the tip of the lens barrel 35 with the surface of the lens 21 exposed to the outside air. The lens barrel 35 holding the lens 21 serves as a lens case. The lens case is screwed into the camera case 44 and is accommodated in the camera case 41.

  Here, the lens barrel 35 in the in-vehicle camera 13 of the third embodiment is different from the lens barrel 31 (see FIG. 1) in the in-vehicle camera 11 (see FIG. 1) of the first embodiment. The lens 21 is held by the lens frame 36 of the body. That is, the lens 21 is sandwiched between a lens barrel 35 and a lens frame 36 which is a separate part from the lens barrel 35, and is fixed by screwing the lens frame 36 into the lens barrel 35. The lens frame 36 is formed with a plurality of slits 37 extending radially outward from the inner end holding the lens 21 at regular intervals.

  In this way, the plurality of slits 37 are formed radially at regular intervals so that when the in-vehicle camera 13 is installed, at least one slit 37 is positioned on the lower edge side of the inclined lens 21. Because. That is, the in-vehicle camera 13 is often installed near the rear garnish of the vehicle so that the depression angle is about 45 °. Further, when the lens frame 36 is screwed into the lens barrel 35, the position where the lens frame 36 stops due to the screwing rotation is not specified. Therefore, by forming a plurality of slits 37 in a radial pattern in advance, the lens 21 of the in-vehicle camera 13 installed with a depression angle of about 45 ° no matter where the lens frame 36 stops at any position of screwing. Any one of the slits 37 is surely located on the lower edge side of.

  In addition, the slit 37 positioned on the lower edge side of the lens 21 in this manner serves as a water conduit for allowing water droplets such as raindrops attached to the peripheral edge of the lens 21 to escape outside the optical effective diameter. That is, water droplets that have flowed down along the surface of the hemispherical lens 21 tend to collect on the lower edge of the lens 21 (near the boundary between the lens 21 and the lens frame 36), but on the lower edge side of the lens 21. The slits 37 that are positioned serve as water conduits and act to release water droplets.

  Therefore, in the in-vehicle camera 13 according to the third embodiment, the slit 37 serves as a water conduit for water droplets, and water is not collected on the lower edge of the lens 21 and is drained from the surface of the lens 21. Water drops are not reflected on the image, and the image is not distorted by the water drops. In addition, the view of the back view is not narrowed and the quality of the video is not deteriorated by inorganic salts such as calcium which are dried out from the water droplets.

The embodiment of the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and various modifications such as the following are possible.
(1) In each embodiment, as the optical device, the vehicle-mounted camera 11, the vehicle-mounted camera 12, and the vehicle-mounted camera 13 used outdoors are given as examples. However, the optical device is limited to such a vehicle-mounted camera 11 and the like. I can't. That is, in addition to the lens 21 and the lens 22 having a surface exposed to the outside air, various lens devices including optical members such as a light-transmitting optical filter, a hood, and a mirror that are held in a state where the surface is exposed to the outside air, and light transmission An optical device such as a neutral optical filter device, a hood, or a mirror device may be used.

  (2) In each embodiment, the on-vehicle camera 11 etc. in which the lens 21 etc. directly touch the outside air is taken as an example. It is also applicable to an optical device in which an optical member such as a cover glass is installed in front of the lens 21 or the like. In this case, a water conduit is formed in a holding member that holds a cover glass or the like.

  (3) In each embodiment, although the slit 33, the slit 34, and the slit 37 were mentioned as an example of a water conduit, a water conduit is not restricted to such a slit 33 grade | etc.,. For example, a wavy step or the like may be used, and the cross section thereof may be V-shaped or semicircular in addition to the concave shape. In addition, it is most effective to perform a hydrophilic film treatment on such a step and the holding member on which the step is formed. Furthermore, the hydrophilic treatment or the water repellent treatment may be applied to the entire camera casing 41 or the like, or the concave groove 43 formed in the camera casing 42.

  (4) In each embodiment, a plurality of slits 33, slits 34, and slits 37 are radially formed at regular intervals as water conduits. However, when the vehicle-mounted camera 11 or the like is installed, at least the lens 21 or the like What is necessary is just to form in the position used as the lower edge part side.

  (5) In each embodiment, the lens barrel 31 or the like holding the lens 21 or the like serves as a lens casing, and this lens casing is screwed into the camera casing 41 or the like. 41 and the like may be not only separate but also one (for example, a camera housing that also serves as the lens barrel 31). The lens barrel 31 and the like can be formed not only of a synthetic resin but also of a metal such as stainless steel or aluminum.

It is the front view and perspective view which show the vehicle-mounted camera of 1st Embodiment. It is sectional drawing explaining the flow of the water droplet in the vehicle-mounted camera of 1st Embodiment. It is a side view which shows the water drop dripping experiment on the resin plane. It is the front view and perspective view which show the vehicle-mounted camera of 2nd Embodiment. It is sectional drawing explaining the flow of the water droplet in the vehicle-mounted camera of 2nd Embodiment. It is the front view and perspective view which show the vehicle-mounted camera of 3rd Embodiment. It is the perspective view and sectional drawing which show the conventional vehicle-mounted camera.

Explanation of symbols

11, 12, 13 Car-mounted camera 11 (optical device)
21,22 Lens (optical member)
31, 35 Lens barrel (holding member)
33, 34, 37 Slit (water conduit)
41, 42, 44 Camera housing (housing)
43 Groove (auxiliary waterway)
θ Water drop contact angle

Claims (10)

An optical member that is held with the surface exposed to the outside air;
A holding member for holding a peripheral edge of the optical member,
The holding member is formed with a water conduit extending outward from an inner end holding the optical member,
The optical apparatus according to claim 1, wherein the water guide channel allows water droplets such as raindrops attached to a peripheral portion of the optical member to escape outside the optical effective diameter. The optical device according to claim 1.
The said water conduit is a level | step difference extended in the radial direction toward the outer side from the inner edge part holding the said optical member. The optical apparatus characterized by the above-mentioned. The optical device according to claim 1.
The water conduit is a step extending radially from the inner end holding the optical member toward the outer side,
The optical device is characterized in that the step has an acute end shape at the inner end and a contact state with water droplets such as raindrops is equal to or greater than the contact angle of water. The optical device according to claim 1.
The said water conduit is a slit extended in a radial direction toward the outer side from the inner edge part holding the said optical member. The optical apparatus characterized by the above-mentioned. The optical device according to claim 1.
The optical apparatus is characterized in that a plurality of the water conduits extend radially from the inner end portion holding the optical member to the outside at regular intervals. The optical device according to claim 1.
The optical member is held with the optical axis inclined downward from the horizontal direction,
The said water conduit is formed in the lower edge part side of the said inclined optical member. The optical apparatus characterized by the above-mentioned. The optical device according to claim 1.
A housing for housing the holding member holding the optical member;
The optical device, wherein the housing has an auxiliary water conduit formed on an extended line at a position corresponding to the water conduit formed in the holding member. The optical device according to claim 1.
The optical apparatus, wherein the water conduit is subjected to a hydrophilic treatment. The optical device according to claim 1.
The optical conduit is formed by subjecting the surface layer of the holding member to a hydrophilic treatment by a laser ablation method. The optical device according to claim 1.
The optical conduit is formed by subjecting a surface layer of the holding member to a hydrophilic treatment by locally applying or printing a hydrophilic treatment agent.

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