JP6844944B2 - Junction lens, lens unit and camera - Google Patents

Description

The present invention relates to a bonded lens and a camera in which lenses are bonded with an adhesive.

In order to correct chromatic aberration and the like with a smaller number of lenses, a bonded lens in which the lens surfaces of different lenses are bonded with an adhesive may be used. One of the problems of the bonded lens is the mixing of air bubbles in the adhesive layer. The presence of air bubbles in the adhesive layer may cause ghosts / flares, making it impossible to obtain the desired optical performance. Further, when the lens becomes relatively hot, the air expansion in the bubbles may cause adhesive peeling starting from the bubbles.

One factor in the generation of air bubbles is the amount of adhesive. That is, a predetermined amount of highly viscous adhesive may not sufficiently wrap around between the lenses, and bubbles may be generated. Here, when the amount of the adhesive is increased in the adhesion of the lens, the adhesive overflows from between the adhesive surfaces of the lens to the outside. In this case, the adhesive that overflows to the reference surface of the outer peripheral portion of the lens that determines the position of the lens is solidified, and the adhesive that is solidified on the reference surface deteriorates the accuracy when installing the lens. Therefore, it has been proposed to provide an adhesive reservoir that prevents the adhesive overflowing from the adhesive portion from leaking to the outside even if the amount of the adhesive is increased in order to prevent the generation of air bubbles (for example, patent). Refer to Documents 1 and 2).

Japanese Unexamined Patent Publication No. 2014-19707 Japanese Unexamined Patent Publication No. 5-19104

By the way, the factor of bubble generation is not necessarily only the amount of the adhesive, but the bubbles generated at the time of injecting the adhesive may remain between the lenses to which they are adhered to each other. In this case, if the amount of adhesive is large and the adhesive overflows from the adhesive portion, there is a high possibility that air bubbles will be expelled. For example, when the air bubbles are near the center of the lens, It is difficult to expel air bubbles out of the effective diameter range described below for the lens.

Here, as shown in FIGS. 7 and 8, the two lenses 1 and 2 are arranged one above the other and adhered to each other, and the adhesive is injected into the upwardly facing concave surface 4 of the lower lens 2. A case where the convex surface 3 facing downward of the upper lens 1 is adhered to the concave surface 4 will be described. In FIGS. 7 and 8, the curvature of the concave surface 4 of the lens 2 is deformed to be larger than the curvature of the convex surface 3 of the lens 1 in order to clarify the problem. Further, the lenses 1 and 2 are shown only in the effective diameter portion. The effective diameter indicates a portion of the lens that is set in the lens, has acceptable optical characteristics, and can actually be used as a lens, and is a circle centered on the optical axis of the lens. Shown as the diameter of.

As shown in FIG. 7, the adhesive 7 injected into the concave surface 4 of the lower lens 2 is in a state of being accumulated in the central portion on the lower side of the concave surface 4. In this state, if bubbles 5 and 6 are generated in the adhesive 7 at the time of injecting the adhesive 7 or at the start of adhesion, the bubbles 5 and 6 are present in the central portion of the concave surface 4 where the adhesive 7 is located. In this state, as shown in FIG. 8, when the upper lens 1 is lowered with respect to the concave surface 4 of the lower lens 2 to bring the convex surface 3 closer to the concave surface 4, the adhesive 7 is applied to the concave surface 4 and the central portion of the convex surface 3. Will spread to the periphery. At this time, the bubbles 6 on the peripheral edge of the adhesive 7 accumulated in the central portion of the concave surface 4 are likely to be pushed out to the peripheral edges of the lenses 1 and 2 at the time of adhesion, but are located in the central portion of the accumulated adhesive 7. Even if the amount of the adhesive 7 is increased to some extent, the bubbles 6 may remain inside the effective diameters of the lenses 1 and 2. In particular, as described above, when the curvature of the concave surface 4 is larger than the curvature of the convex surface 3, the gap between the lenses 1 and 2 narrows from the center of the lenses 1 and 2 toward the peripheral edge, so that the gap between the lenses 1 and 2 becomes closer to the center of the lenses 1 and 2. The bubble 5 remains within the effective diameter of the lenses 1 and 2 without expelling the bubble 5 in the lens 1. Further, in a situation where the adhesive is thick on the central side of the lenses 1 and 2 and the adhesive is thin on the peripheral side, the moving speed of the adhesive is slow in the central part of the adhesive and the moving speed of bubbles in the central part of the adhesive. Slows down. Even if the curvatures of the concave surface 4 and the convex surface 3 are substantially the same and the shape of the concave surface 4 and the shape of the convex surface 3 substantially overlap, the central portion of the adhesive 7 accumulated in the central portion of the concave surface 4 There is a high possibility that the bubbles 5 cannot be expelled and remain within the effective diameters of the concave surface 4 and the convex surface 3. In FIG. 8, the lens 1 and the lens 2 have not yet moved to the bonding position, and are in a state of being slightly separated from each other at the time of bonding.

Further, in order to suppress the generation of air bubbles, a certain amount of adhesive is required. In this case, it is necessary to provide an adhesive reservoir as described above in the vicinity of the outer periphery of the effective diameter of the lens. However, the adhesive that overflows on the adhesive reservoir side may make it difficult to align the lenses with each other at the time of adhesion.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a bonded lens and a camera capable of suppressing air bubbles from being mixed into an adhesive when the lenses are bonded together.

The bonded lens of the present invention is a bonded lens in which lenses are bonded to each other with an adhesive.
The adhesive layer between the bonded lenses is thickened from the center side of the effective diameter to the peripheral edge side of the effective diameter range within the optically effective diameter of the lens, and is said to be outside the effective diameter. It is characterized by being thinner than the thickest part within the effective diameter range.

According to such a configuration, when the lenses are joined to each other, the adhesive is thin on the center side of the effective diameter and thick on the peripheral side, and the whole gradually becomes thin and spreads. As a result, the bubbles of the adhesive move so as to be pushed out from the thin central side to the thick peripheral side as the lenses to be bonded approach each other, and are easily discharged to the outside of the effective diameter.

In addition, a lens composed of a combination of concave and convex surfaces is formed by shifting the centers of the lenses to be bonded to each other, for example, by tilting the central axis of the other lens with respect to the central axis of one lens or shifting it substantially in parallel. When the distance between lenses differs depending on the direction based on the shape between the lenses, the highly viscous adhesive flows in the direction where the distance is wide and easy to flow, so that the adhesive spreads to the side where the distance is narrow. There is a risk that bubbles will be generated without this. In the present invention, by thinning the adhesive layer outside the effective diameter, it is possible to prevent the adhesive from flowing only in a biased direction and further suppress the generation of bubbles.

In the configuration of the present invention, it is preferable that the thickness of the adhesive layer gradually increases in the range of the effective diameter from the center of the effective diameter toward the peripheral edge of the range of the effective diameter.

According to such a configuration, the distance between the lenses to be bonded gradually increases from the center of the effective diameter range toward the peripheral edge, so that the bubbles of the adhesive move without stagnation when the lenses are bonded. The possibility is high, and it becomes easy to discharge the air bubbles to the outside of the effective diameter.

In the configuration of the present invention, it is preferable that an adhesive reservoir in which the adhesive overflowing from the adhesive layer flows into the outside of the effective diameter between the bonded lenses is formed so as to communicate with the adhesive layer. ..

According to such a configuration, even if more adhesive is used than the amount of the adhesive that fills the adhesive layer, the adhesive flows into the adhesive reservoir and does not overflow to the outside, so that the amount of the adhesive is large. As a result, the above-mentioned bubbles can be easily discharged out of the effective diameter range.

Further, in the configuration of the present invention, it is preferable that a positioning structure for determining the axial position and the radial position of the lenses is provided outside the adhesive reservoir of the bonded lenses.

According to such a configuration, the adhesive is prevented from infiltrating into the positioning structure portion, the deterioration of the alignment accuracy is suppressed, and the adhesive is infiltrated into the positioning structure, which makes the bonding difficult. Can be prevented.

Further, in the above-mentioned configuration of the present invention, between the bonded lenses, an annular shape in which the adhesive layer and the annular adhesive reservoir surrounding the adhesive layer are communicated with each other on the outer peripheral side of the adhesive layer. Adhesive passage is provided,
The peripheral edge of the curved adhesive layer, which is convex on one side and concave on the other side, inclines toward the other as it goes outward, whereas the adhesive passage has one side toward the outside. It is preferable that there is a portion that slopes toward it.

According to such a configuration, as described above, the central axis of the other lens is tilted or substantially parallel to the central axis of one lens, so that the lenses are composed of a combination of concave and convex surfaces. When the distance between the lenses is different depending on the direction based on the shape between the lenses, the adhesive layer has a portion in the inclined direction opposite to the inclined direction of the peripheral edge portion of the adhesive layer. In the peripheral portion of the lens, the distance is narrowed in the portion where the inclination of the adhesive passage on the outside of the portion where the distance is wider than the others is reversed.
As a result, when the two lenses are bonded together, when the adhesive preferentially flows to the portion where the distance between the two lenses is widened as described above, the outer side thereof is described above. In, the adhesive passage becomes narrow and the adhesive becomes difficult to flow. Therefore, it is possible to more efficiently prevent the adhesive from flowing preferentially to the wider side of the adhesive layer and the adhesive is not sufficiently filled on the narrow side of the adhesive layer.

The camera of the present invention is characterized by including a junction lens having the above configuration. According to such a configuration, for example, in an in-vehicle camera or a camera incorporated in a mobile device for which high resolution and miniaturization are desired, the image quality is regulated by restricting the mixing of air bubbles into the adhesive layer of the bonded lens with a small number of lenses. It is possible to suppress the variation of the lens and increase the resolution.

According to the present invention, it is possible to prevent air bubbles from being mixed into the adhesive layer within the effective diameter of the bonded lens.

It is sectional drawing which shows the lens unit of the camera which has the junction lens of embodiment of this invention. It is sectional drawing which shows the junction lens. The same is a cross-sectional view showing a bonded lens having a deformed curvature in order to explain the movement of air bubbles during manufacturing of the bonded lens. It is a figure for demonstrating the bonding of the lens which deformed the two curvatures which become the bonding lens. It is a figure for demonstrating the bonding of the lens which deformed the two curvatures which become the bonding lens. It is a figure for demonstrating the misalignment of two lenses serving as a junction lens. It is a figure for demonstrating the bubble of the adhesive at the time of manufacturing a conventional bonded lens. It is a figure for demonstrating the bubble of the adhesive at the time of manufacturing a conventional bonded lens.

Hereinafter, embodiments of the present invention will be described.
The lens unit 11 having the bonded lens 18 of the present embodiment shown in FIG. 1 is for, for example, an in-vehicle camera, and is installed on the outside of an automobile with at least the end portion of the lens unit 11 on the object side exposed. ..

As shown in FIG. 1, the lens unit 11 of this embodiment includes a cylindrical lens barrel 12 and a plurality of (for example, four) lenses 13, 14, 15, 18 arranged in the lens barrel 12. It is provided with two drawing members 21 and 22. An in-vehicle camera including the lens unit 11 includes the above-mentioned lens unit 11, a substrate having an image sensor (not shown), and an installation member (not shown) for installing the substrate in a vehicle such as an automobile.

The plurality of lenses 13.14.15.18 fixed and supported by the lens barrel 12 are arranged in a state where their respective optical axes are aligned with each other, and the respective lenses 13 and 14 are arranged along one optical axis. , 15 and 18 are arranged side by side to form one group of lenses used for imaging. Further, the lens 18 is a bonded lens 18, and the lens 16 and the lens 17 are bonded to each other.

The first aperture member 21 of the two aperture members 21 and 22 from the object side (one end of the lens barrel 12) is arranged between the second lens 14 and the third lens 15 from the object side. Has been done. The second aperture member 22 from the object side is arranged between the third lens 15 and the fourth lens 16 from the object side. The diaphragm members 21 and 22 are an "aperture diaphragm" that limits the amount of transmitted light and determines an F value that is an index of brightness, or a "light-shielding diaphragm" that blocks light rays that cause ghosts and light rays that cause aberrations. ..

The inner diameter of the lens barrel 12 is reduced by caulking one end on the object side, and the end on the object side of the lens barrel 12 is smaller than the outer diameter of the lens 13 on the most object side that is expropriated inside. The inner diameter of is reduced. Further, at the other end of the lens barrel 12 on the image side, a frame portion 24 having an opening having a diameter smaller than that of the junction lens 18 is provided. A plurality of lenses 13, 14, 15, 18 and aperture members 21 and 22 forming a lens group are held in the lens barrel 12 by these frame portions 23.24. The frame portion 23 may be attached to the end portion of the lens barrel 12 on the object side after the lenses 13, 14, 15, and 18 are housed in the lens barrel 12.

On the outer peripheral surface of the lens 13 on the most object side, a reduced diameter portion having a smaller diameter is provided on the image side portion of the lens 13, and an O ring 26 as a sealing member is provided on the reduced diameter portion. The outer peripheral surface of the lens barrel 12 and the inner peripheral surface of the lens barrel 12 are sealed by the object-side end of the lens barrel 12. This makes it possible to prevent fine particles such as water and dust from entering the lens barrel 12 from the end of the lens unit 11 on the object side.

The inner diameter of the lens barrel 12 gradually decreases from the object side to the image side. Correspondingly, the outer diameters of the lenses 13, 14, 15, and 18 become smaller as their arrangement positions move from the object side to the image side. Basically, the outer diameters of the lenses 13, 14, 15, and 18 are substantially equal to the inner diameters of the portions of the lens barrel 12 on which the lenses 13, 14, 15, and 18 are supported. However, as shown in FIG. 2, the inner peripheral surface of the lens barrel 12 is not a cylinder but a polygon such as a dodecagon. Further, on the outer peripheral surface of the lens barrel 12, a flange portion 25 used for installing the lens barrel 12 on an in-vehicle camera is provided on the outer peripheral surface of the lens barrel 12 in a flange shape.

In the present embodiment, the lens 13 exposed to the outside of the vehicle (outside the lens barrel 12) on the most object side of the lenses 13, 14, 15, 18 is a glass lens, and the lenses 14, 15, 18 are resin lenses. There is.

The image-side bonded lens 18 has a surface on the image-side of the outer peripheral portion that is orthogonal to the optical axis as a reference surface. The reference surface of the bonded lens 18 is provided at the image side end of the lens barrel 12 described above, and abuts on the reference surface on the inner surface side of the frame portion 23 having an opening having an inner diameter smaller than the outer diameter of the bonded lens 18. It has become like.

In the present embodiment, as shown in FIG. 2, the bonded lens 18 is formed by bonding a concave lens 16 on the object side and a convex lens 17 on the image side with an adhesive 7 (shown in FIG. 4 and the like). In FIGS. 2 to 6 below, these are shown with the concave lens 16 facing down and the convex lens 17 facing up, as in the state when the lens 16 and the lens 17 are bonded together. The top and bottom in the following description are based on the above-mentioned vertical relationship at the time of bonding. In FIGS. 2 to 6, the upper side is the image side and the lower side is the object side.

The concave lens 16 has a concave surface 31 on the image side and a convex surface 36 on the object side. Further, the concave lens 16 includes a lens portion 16b within the range of its optical effective diameter r and an annular flange portion 16a formed on the outside of the outer peripheral edge thereof. Note that FIG. 2 shows the range of the effective diameter r. Further, when the concave lens 16 and the convex lens 17 are bonded to each other, the adhesive 7 is injected into the concave surface 31 with the concave surface 31 of the concave lens 16 facing up.

The convex lens 17 includes a convex surface 41 on the object side through which light passes and a convex surface 46 on the image side. Further, the convex lens 17 includes a lens portion 17b within the range of its effective diameter r and an annular flange portion 17a formed on the outside of the outer peripheral edge thereof.
When the concave lens 16 and the convex lens 17 are bonded to each other, the convex surface 41 on the object side of the convex lens 17 is bonded to the concave surface 31 on the image side of the concave lens 16 with an adhesive 7.

In this case, the adhesive layer 51 is formed between the concave surface 31 of the concave lens 16 and the convex surface 41 of the convex lens 17. Although the adhesive 7 is not shown in FIG. 2, the adhesive layer 51 is filled with the adhesive 7. The range of the adhesive layer 51 is wider than the range of the effective diameter r through which light rays pass.

An annular recess 43 serving as an adhesive reservoir 53 is formed in the flange portion 17a on the outer side of the effective diameter r of the lens 17. The adhesive reservoir 53 is formed by a concave portion 43 of the convex lens 17 and a flat lid portion 33 of the concave lens 16 facing the concave portion 43. Further, these are communicated between the adhesive reservoir 53 and the adhesive layer 51. An adhesive passage 52 is formed in which the adhesive overflowing from the adhesive layer 51 at the time of joining flows into the adhesive reservoir 53. The adhesive passage 52 is a portion outside the effective diameter r and can be regarded as a part of the adhesive layer 51.

The adhesive passage 52 includes a passage surface 32 which is an annular convex surface in which the cross section between the concave surface 31 of the concave lens 16 and the lid portion 33 is bent in an inverted V shape, and the convex surface 41 and the concave portion 43 of the convex lens 17. It is formed by facing the passage surface 42, which is an annular concave surface whose cross section is bent in an inverted V shape, at a distance. The adhesive passage 52 has an inverted V-shaped cross section, but is longer on the outside than the apex of the effective diameter r from the outer edge to the apex of the inverted V-shape, and further forms an inverted V-shaped portion. On the outside of the inclined portion, there is a passage portion substantially orthogonal to the optical axis direction, and this portion is connected to the adhesive reservoir 53.

In other words, between the bonded lenses 16 and 17, an annular adhesive that communicates the adhesive layer 51 and the annular adhesive reservoir 53 surrounding the periphery of the adhesive layer 61 on the outer peripheral side of the adhesive layer 51. A passage 52 is provided. The peripheral edge of the curved adhesive layer 51, which is convex on one side and concave on the other side, inclines toward the other as it goes outward, whereas the adhesive passage 52 has one side as it goes outward. There is a part that slopes toward you.

With such a configuration, when the lenses 16 and 17 are joined, the adhesive 7 that overflows from the disc-shaped adhesive layer 51 to the outside along the substantially radial direction is circular on the outside of the adhesive layer 51 in a plan view. It reaches the adhesive passage 52 formed in an annular shape, and further flows so as to spread the adhesive outward in the radial direction to reach the adhesive reservoir 53 provided on the outside of the adhesive passage 52. The amount of the adhesive 7 used is greater than or equal to the amount of the adhesive 7 filling the adhesive layer 51 and the adhesive passage 52 and overflowing into the adhesive reservoir 53, and less than the amount further overflowing from the adhesive reservoir 53. Is set to. Further, the thickness of the adhesive passage 52 is thinner than the thickness of the adhesive reservoir 53. Here, the thickness is the length of the lenses 16 and 17 along the optical axis direction.

Further, a step is formed on the outside of the adhesive reservoir 53 of the concave lens 16 so that the outside of the flat surface serving as the lid portion 33 is displaced toward the object side, and a step is formed along the substantially optical axis direction of the corner portion of the step. The surface is a cylindrical radial positioning surface (positioning structure) 34 that determines a position in the radial direction (radial direction) orthogonal to the optical axis direction of the lenses 16 and 17 to be joined. The portion of the radial positioning surface 34 is a columnar convex portion having a short axial length. Further, the outer surface of the radial positioning surface 34, which is a step of the concave lens 16, is the optical axis direction positioning surface (positioning) orthogonal to the optical axis that determines the position of the lenses 16 and 17 to be joined in the optical axis direction (thrust direction). Structure) 35.

Further, a step is formed on the outside of the recess 43 serving as the adhesive reservoir 53 of the convex lens 17 so that the outside of the concave surface is displaced toward the object side with respect to the plane orthogonal to the optical axis. The plane along the axial direction is a cylindrical radial positioning surface (positioning structure) 44 that determines the position in the radial direction (radial direction) orthogonal to the optical axis direction of the lenses 16 and 17 to be joined. The portion of the radial positioning surface 44 is a columnar recess having a short axial length. Further, the outer surface of the radial positioning surface 44, which is a step of the convex lens 17, is the optical axis direction positioning surface (positioning) orthogonal to the optical axis that determines the position of the lenses 16 and 17 to be joined in the optical axis direction (thrust direction). Structure) 45.

At the time of joining, the radial positioning surface 34 forming the columnar convex portion of the concave lens 16 is inserted into the radial positioning surface 44 forming the cylindrical concave portion of the convex lens 17, so that the lenses 16 and 17 are joined. The position in the radial direction is determined, and in this state, the position 35 in the optical axis direction of the concave lens 16 and the positioning surface 45 in the optical axis direction of the convex lens 17 are abutted to determine each other's position along the optical axis direction. Be done.

The thickness of the adhesive layer 51 is the distance between the concave surface 31 of the concave lens 16 and the convex surface 41 of the convex lens 17 when the optical axis direction positioning surface 35 of the concave lens 16 and the optical axis direction positioning surface 45 of the convex lens 17 are butted against each other. Become. In the present embodiment, the thickness of the adhesive layer 51 is not substantially uniform as a whole, and gradually increases toward the outer side in the radial direction within the range of the effective diameter r. In FIG. 3, the change in the distance between the concave surface 31 and the convex surface 41, which is the adhesive layer 51, is shown in a deformed manner.

The concave surface 31 and the convex surface 41 are different in concave and convex, but have substantially the same shape, unlike conventional bonded lenses, which have different shapes. The concave surface 31 and the convex surface 41 are aspherical surfaces, but the curvature of the convex surface 41 is generally larger than the curvature of the concave surface 31. As a result, the distance between the concave surface 31 and the convex surface 41 gradually increases from the center toward the peripheral edge. The concave surface 31 and the convex surface 41 may be spherical surfaces.

The distance between the concave surface 31 and the convex surface 41, which is the adhesive layer 51, gradually increases from the center toward the peripheral edge as described above, but includes a portion where the distance does not change along the radial direction. You may. That is, in the distance between the concave surface 31 and the convex surface 41, there may be a portion having the same interval in a part of the portion from the center toward the peripheral edge.

Further, the outermost peripheral portion of the adhesive layer 51, that is, the adhesive passage 52 outside the portion of the adhesive layer 51 connected to the adhesive passage 52, is thicker than the portion of the adhesive layer 51 connected to the adhesive passage 52. Is getting thinner. That is, in the adhesive passage 52, for example, the thickness becomes thinner toward the adhesive reservoir 53. It is sufficient that the adhesive passage 52 has a narrowed portion so as to be thin. For example, it is preferable that the thickness of the outer side of the above-mentioned adhesive passage 52 is thinner than that of the inner side of the apex portion having an inverted V-shaped cross section.

In such a bonded lens, as shown in FIGS. 4 and 5 in which the lenses 16 and 17 are deformed in the same manner as in FIG. 3, the adhesive layer 51 gradually becomes thicker from the center to the outside. As described above, since the concave surface 31 and the convex surface 41 are formed, when the concave surface 31 and the convex surface 41 are bonded to each other at the time of joining the lenses 16 and 17, the adhesive layer is peripheral from the center side of the lenses 16 and 17. The edge side becomes thicker, and the bubbles 5 and 6 easily move to the peripheral edge side. In particular, when the concave surface 31 and the convex surface 41 are close to each other, the bubbles 5 and 6 are trapped by the hard-to-move adhesive 7 in the vicinity of the concave surface 31 and the convex surface 41 and become difficult to move. The adhesive layer 51 is extruded from the thin center side to the thick peripheral side, and the bubbles 5 and 6 can move outward. As a result, the probability that the bubbles 5 and 6 will come out of the effective diameter r of the adhesive layer 51 increases. Further, it is possible to suppress a state in which the bubbles 5 and 6 stay in the vicinity of the central portion of the adhesive layer 51.

Further, in the present embodiment, the convex surface 41 of the convex lens 17 to be joined and the concave surface 31 of the concave lens 16 have different shapes as described above, so that they are bonded together based on the design of these two surfaces. Aberration can be corrected with higher accuracy than when the concave surface 31 and the convex surface 41 have the same shape. As a result, for example, there is a possibility that the number of lenses used can be reduced.

Further, since the radial positioning surfaces 34, 44 and the optical axial positioning surfaces 35, 45 used for positioning are provided on the outer peripheral side of the adhesive reservoir 53, these radial positioning surfaces 34, 44 and the optical axial positioning are provided. Accurate positioning is possible because the adhesive does not penetrate into the portions where the surfaces 35 and 45 come into contact with each other. Further, when the radial positioning surface 34 forming the cylindrical convex portion of the concave lens 16 is inserted into the radial positioning surface 44 forming the cylindrical concave portion of the convex lens 17, the radial positioning surfaces 34, 44 It is possible to prevent the lenses 16 and 17 from becoming difficult to join due to the penetration of a highly viscous adhesive between them.

As shown in FIG. 6, when the concave lens 16 and the convex lens 17 are joined, the central axis of the concave lens 16 and the central axis of the convex lens 17 may be slightly deviated from each other. For example, there is a possibility that the central axis of the concave lens 16 and the central axis of the convex lens 17 are displaced so that the other obsession chrysanthemum is tilted with respect to one central axis. If the center is largely deviated, the radial positioning surface 34 forming the cylindrical convex portion of the concave lens 16 cannot be inserted into the radial positioning surface 44 forming the cylindrical concave portion of the convex lens 17, and the concave lens 16 and the convex lens cannot be inserted. 17 cannot be joined.

When the concave lens 16 and the convex lens 17 are displaced within the range in which the concave lens 16 and the convex lens 17 can be joined, the adhesive layer 51 which is oblique in the optical axis direction due to the combination of the concave surface 31 and the convex surface 41 is a lens. The thickness of the adhesive layer 51 changes due to the deviation of the centers of 16 and 17. For example, as shown in FIG. 6, when the central axis (optical axis) of the convex lens 17 is tilted to the right in the figure with respect to the central axis (optical axis) of the concave lens 16, the left side of the adhesive layer 51 in the figure is displaced. It is thicker than the right side. In this state, the highly viscous adhesive may flow on the thick side of the adhesive layer 51 and hardly flow on the thin side. In this case, in the worst case, the adhesive did not spread over the entire effective diameter range, and although the amount of the adhesive was increased by providing the adhesive reservoir, the adhesive layer 51 was caused by the lack of the adhesive as in the conventional case. There is a risk that air bubbles will be generated in the air.

In the present embodiment, the adhesive passage 52 on the outer side of the adhesive layer 51 is thinner than the thickest portion of the adhesive layer 51, and has a portion that is inclined in the opposite direction to the inclination of the peripheral portion of the adhesive as described above. As shown in 6, in the portion on the left side of the figure in which the adhesive layer 51 is thicker than the others, the portion where the inclination of the adhesive passage 52 on the outer side is reversed as described above is thinner than the others. Further, in the portion on the right side of the drawing in which the adhesive layer 51 is thinner than the others, the portion where the inclination of the adhesive passage 52 on the outer side is reversed as described above becomes thicker than the others.

With such a structure, the adhesive passage 52 connected to the thicker side of the adhesive layer 51 becomes thinner, so that it is possible to prevent the highly viscous adhesive from flowing only to the thicker side of the adhesive layer 51. .. As a result, it is possible to suppress the generation of air bubbles due to the deviation of the centers of the concave lens 16 and the convex lens 17 as described above. It should be noted that the deviation of the centers of the concave lens 16 and the convex lens 17 may cause the central axes of the concave lens 16 and the convex lens 17 to be displaced in parallel rather than being tilted. In this case as well, the adhesive layer 51 becomes thinner on one side (for example, the right side) and thicker on the other side (for example, the left side) with the center as the boundary. In this case as well, in the adhesive passage 52 outside the adhesive layer 51, the adhesive layer 51 becomes thinner on the left side where it becomes thicker, and the adhesive layer 51 becomes thicker on the right side where it becomes thinner. It is possible to prevent the thinned side from becoming inaccessible.

The bonded lens of the present invention is not limited to a resin lens, and may be a glass lens. Further, the camera is not limited to the in-vehicle camera, and can be applied to various cameras.

11 Lens unit 12 Lens barrel 13, 14, 15 Lens 16, 17 Lens (lens to be joined)
18 Bonded lens 51 Adhesive layer 52 Adhesive passage 53 Adhesive layer r Effective diameter

Claims (10)

It is a bonded lens in which lenses are bonded to each other with an adhesive.
The adhesive layer between the bonded lenses is formed thicker within the optically effective diameter of the lens from the center side of the effective diameter to the peripheral edge side of the effective diameter range, and is formed outside the effective diameter. Formed thinner than the thickest part within the effective diameter range,
An adhesive reservoir into which the adhesive overflowing from the adhesive layer flows is formed on the radial outer side of the adhesive layer so as to communicate with the adhesive layer.
An adhesive passage is formed between the outer peripheral side of the adhesive layer and the adhesive reservoir.
The outer peripheral side portion of the adhesive layer is inclined to one side in the axial direction from the inside to the outside in the radial direction.
The adhesive passage has a portion that inclines from the inside to the outside in the radial direction to the side opposite to one side in the axial direction.
A bonded lens characterized in that a positioning structure for determining the positions of the lenses with respect to each other is provided on the outside of the adhesive reservoir. The bonded lens according to claim 1, wherein the thickness of the adhesive layer gradually increases in the effective diameter range from the center of the effective diameter toward the peripheral edge of the effective diameter range. The bonded lens according to claim 1 or 2, wherein the positioning structure determines mutual axial positions and radial positions of the lenses. A lens unit characterized in that a plurality of lenses including the bonded lens according to any one of claims 1 to 3 are supported in a lens barrel. A camera comprising the lens unit according to claim 4 and an image sensor that forms an image of light rays incident on the lens unit. A bonded lens in which a first lens having a concave surface and a second lens having a convex surface are bonded by an adhesive.
The adhesive layer between the concave surface of the first lens and the convex surface of the second lens that are bonded to each other is thickened from the central side of the convex surface and the concave surface to the convex surface and the outer peripheral side of the concave surface.
On the radial outer side of the adhesive layer, an adhesive passage having a portion thinner than the thickest portion on the outer peripheral side of the adhesive layer is formed so as to communicate with the adhesive layer.
On the radial outer side of the adhesive layer, an adhesive reservoir is formed in which the adhesive overflowing from the adhesive layer flows in through the adhesive passage.
The outer peripheral side portion of the adhesive layer is inclined to one side in the axial direction from the inside to the outside in the radial direction.
The adhesive passage has a portion that inclines from the inside to the outside in the radial direction to the side opposite to one side in the axial direction.
A bonded lens characterized in that a positioning structure for determining the positions of the lenses with respect to each other is provided on the outside of the adhesive reservoir. The bonding lens according to claim 6 , wherein the thickness of the adhesive layer gradually increases from the center side of the convex surface and the concave surface toward the outer peripheral side of the convex surface and the concave surface. The bonded lens according to claim 6 or 7 , wherein the positioning structure determines mutual axial positions and radial positions of the lenses. A lens unit characterized in that a plurality of lenses including the bonded lens according to any one of claims 6 to 8 are supported in a lens barrel. A camera comprising the lens unit according to claim 9 and an image sensor that forms an image of light rays incident on the lens unit.

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