JP2021005022A - Lens unit and manufacturing method of the same - Google Patents

Abstract

To improve position accuracy between lenses in a lens unit in which a glass-made lens and a plastic-made lens are combined.SOLUTION: A fifth lens L5 is configured integrally with an optically functioning fifth lens main body L5A, and fifth lens flange part L5B surrounding a periphery of the fifth lens main body L5A around an optical axis, and is molded by a glass mold. The fifth lens L5 directly abuts on a cementing lens L60 not via other member in a direction along an optical axis A, and thereby, a position relationship between the fifth lens L5 and the cementing lens L60 is accurately determined. In this case, the cementing lens L60 directly abuts on a lens barrel 10 in the direction along the optical axis A and thereby a position of the cementing lens in the direction along the optical axis A is determined, and thus, a position relationship in the direction along the optical axis A between the cementing lens L60 and the lens barrel 10 is also accurately determined. Therefore, a position relationship (an interval) in the direction along the optical axis A between the fifth lens L5, the cementing lens L60 and the lens barrel 10 can be determined, in particular, with accuracy.SELECTED DRAWING: Figure 1

Description

The present invention relates to a lens unit including a plurality of lenses and a lens barrel for fixing them on the outside, and a method for manufacturing the same.

For example, as an optical system used in an image pickup device mounted on an automobile, a surveillance camera, etc., a plurality of lenses are set as optical axes (optical axis of the image pickup device) from the object side to the image side (image sensor side). Lens units arranged in the direction are used. This lens unit is designed so that an image of an object by visible light can be imaged well on an image sensor. Therefore, it is required that the positional relationship between each lens, the positional relationship between each lens and the lens barrel, and the positional relationship between the lens unit and the image sensor are fixed with high accuracy.

Among the plurality of lenses used, there are those made of glass and those made of resin material (plastic). The glass lens has advantages such as being hard to be scratched and the temperature dependence of the refractive index is small, whereas the plastic lens has an advantage that various shapes can be manufactured at low cost. Therefore, for example, a plastic lens is preferable as the aspherical lens. Further, it is possible to form a structure in the lens itself for fixing the positional relationship between adjacent lenses or between the lens and the lens barrel, but in a plastic lens, an optically functional spherical surface or an aspherical surface can be formed. It is also easy to integrally form the lens surface of the above and such a structure. As the material of the plastic lens, an amorphous plastic such as polycarbonate having good optical properties is used. For this reason, in the lens unit as described above, it is preferable that only the lens unit preferably made of glass is made of glass and the other lenses are made of plastic in order to make the image pickup apparatus inexpensive.

A lens unit in which a plastic lens and a glass lens are combined and housed in a lens barrel is described in, for example, Patent Document 1. In this lens unit, the first to seventh lenses are sequentially provided from the object side to the image side, and among them, the first lens that is exposed to the outside and is particularly vulnerable to scratches and the position particularly close to the aperture. A glass lens is used as the fourth lens, which is required to have a small temperature dependence of the refractive index.

Of these, the fourth lens in particular is made of glass itself, but is actually fixed in the lens barrel with its periphery fixed to the plastic glass lens holding portion. Therefore, in reality, the structure in which the fourth lens and the glass lens holding portion are integrated can be treated as the same as the plastic lens. The lens barrel, the structure for fixing the positional relationship between the adjacent plastic lens and this structure are all formed in the glass lens holding portion. At this time, this structure is configured so that the positional relationship can be finely adjusted. Therefore, by using this lens unit, it is possible to inexpensively obtain an image pickup apparatus capable of obtaining good image pickup characteristics.

JP-A-2018-54922

In the structure described in Patent Document 1, the positional relationship between the fourth lens, which is a glass lens, and the adjacent lens is indirectly determined via the glass lens holding portion. Therefore, the position accuracy between the adjacent lens and the glass lens actually largely depends on the position accuracy between the glass lens holding portion of the fourth lens. Therefore, in this structure, it is difficult to stably increase the accuracy of the positional relationship between the fourth lens and the adjacent lens.

The present invention has been made in view of such a situation, and an object of the present invention is to improve the positional accuracy between lenses in a lens unit in which a glass lens and a plastic lens are combined.

The lens unit according to the present invention is a mirror in which a first lens, which is the most object side, and a plurality of lenses arranged on the image side of the first lens are laminated along the optical axis from the object side to the image side. A lens unit fixed to a cylinder, one of a plurality of the lenses is a lens body configured to include an optical path and a radial outside of the lens body as viewed from the optical axis. The flange portion formed in the above is a glass lens made of glass integrally formed, and the glass lens is supported on the outer side in the radial direction by a lens holder made of a resin material. The two adjacent lenses, which are the lenses housed inside the lens and adjacent to the glass lens in the direction along the optical axis, come into contact with the lens holder to form the glass lens in the direction along the optical axis. The positional relationship between the two is determined, and one of the two adjacent lenses abuts on the flange portion to determine the positional relationship with the glass lens in the direction along the optical axis. There is.

In this configuration, the glass lens is fixed in the lens barrel while being supported by the lens holder, and the adjacent adjacent lenses adjacent to the glass lens on the object side and the image side in the direction along the optical axis are both lens holders. Contact with. However, by directly contacting one of the adjacent lenses with the flange portion of the glass lens, the positional relationship with the glass lens in the direction along the optical axis is determined. Thereby, the positional relationship between the adjacent lens and the glass lens can be determined particularly precisely. Further, a glass lens having such a shape can be easily manufactured by a glass mold.

At this time, the one adjacent lens is formed in an annular shape on the outer side in the radial direction from the lens surface so as to protrude from the lens surface on the glass lens side so as to abut the flange portion. A flange portion on the lens side may be provided.

In this case, in the adjacent lens on the side that directly contacts the glass lens, the adjacent lens side flange portion for locking the glass lens is formed without affecting the lens surface. If the adjacent lens is made of a resin material, such a shape can be easily formed by molding.

At this time, one of the lens holder and the one adjacent lens is press-fitted and fixed to the lens barrel, and the other one of the lens holder and the one adjacent lens is said. By engaging the engaging structures formed with each other with one, the mutual positional relationship in the radial direction may be determined.

In this case, one of the adjacent lenses that are in direct contact with the lens holder and the glass lens is in contact with the inner surface of the lens barrel. On the other hand, the other one of them is positioned in the radial direction by engaging this one with the engaging structure. Thereby, the positional relationship in the radial direction between the glass lens and the adjacent lens can be precisely determined.

At this time, the one adjacent lens is arranged on the image side of the glass lens, is press-fitted and fixed to the lens barrel, and engages with each other formed engaging structures with the lens holder. By matching, the positional relationship in the radial direction with respect to the lens holder may be determined.
In this case, the adjacent lens on the side that directly contacts the glass lens is the adjacent lens on the image side. In this case, when the manufacturing method described later is executed, the force in the direction of separating the glass lens and the adjacent lens is suppressed, and the glass lens is particularly suppressed from falling off from the lens holder during assembly.

At this time, the lens holder has a lens built-in hole which is a through hole along the optical axis and to which the glass lens is mounted, and an object side lens holder which is a plane perpendicular to the optical axis formed on the object side. A surface and an adhesive groove, which is a plurality of grooves locally dug from the lens holder surface on the object side, are provided around the lens incorporating hole so as to be connected to the lens incorporating hole on the object side. An adhesive layer for fixing the glass lens and the lens holder may be formed in the adhesive groove.
In this case, the adhesive in the groove for the adhesive can be used to firmly fix the glass lens and the lens holder, and this work becomes easy.

At this time, a diaphragm is provided between the other of the two adjacent lenses and the glass lens, and the diaphragm is formed with a plurality of positioning holes in the circumferential direction around the optical axis, and the lens holder On the object side, a plurality of convex portions protruding from the lens holder surface on the object side toward the object side are formed corresponding to the positioning holes, and the diaphragm engages the convex portions with the positioning holes. It may be mounted on the lens holder in a state of being locked to the lens holder surface on the object side.
In this case, since the aperture is further fixed to the lens holder, the positional relationship between the glass lens and the aperture is precisely determined. In addition, the work of attaching the diaphragm is easy.

The method for manufacturing a lens unit according to the present invention includes a lens holder positioning step of arranging the lens holders with respect to the one adjacent lens in a state where the engaging structures formed are engaged with each other. After the lens holder positioning step, the lens insertion step of inserting the glass lens into the lens incorporating hole in the lens holder and the adhesive groove after the lens insertion step are filled with the adhesive before solidification to solidify. It includes a bonding step and a lens assembly fixing step of press-fitting and fixing the structure in which the one adjacent lens, the lens holder, and the glass lens are integrated to the lens barrel after the bonding step. ..
In this case, after the positional relationship between the adjacent lens on the side that directly contacts the glass lens and the lens holder is determined by the lens holder positioning step, the positional relationship between the glass lens and this adjacent lens is lens-inserted. It is determined in the process, and then the glass lens and the lens holder are fixed by the bonding process. After that, when the adjacent lens, the lens holder, and the glass lens are integrally press-fitted and fixed to the lens barrel, the positional relationship between them is maintained and the lens is prevented from falling off from the lens holder.

Further, the method for manufacturing a lens unit according to the present invention is a lens holder positioning step of arranging the lens holders with respect to the one adjacent lens in a state where the engaging structures formed are engaged with each other. And the lens insertion step of inserting the glass lens into the lens incorporating hole in the lens holder after the lens holder positioning step, and the adhesive before solidification is put into the adhesive groove after the lens insertion step. The aperture is placed on the lens holder surface on the object side in a state where each of the plurality of positioning holes is engaged with each of the plurality of convex portions in the lens holder after the solidification step and the lens holder. A lens that press-fits and fixes the structure in which the one adjacent lens, the lens holder, the glass lens, and the aperture after the aperture fixing step are integrated with the lens barrel. It includes a set fixing step.
Also in this case, as in the above manufacturing method, when the adjacent lens, the lens holder, and the glass lens are integrally press-fitted and fixed to the lens barrel, the positional relationship between them is maintained and from the lens holder. The lens is prevented from falling off. At this time, the aperture is also fixed in this, and the positional relationship between the glass lens and the aperture is precisely determined.

According to the present invention, in a lens unit in which a glass lens and a plastic lens are combined, the positional accuracy between the lenses can be improved.

It is sectional drawing of the lens unit which concerns on embodiment. It is sectional drawing (a) and perspective view (b) of the lens barrel used in the lens unit which concerns on embodiment. It is an exploded assembly drawing of the lens unit which concerns on embodiment. It is a perspective view seen from the object side (a) and the image side (b) of the fifth lens (glass lens) in the lens unit which concerns on embodiment. It is a perspective view seen from the object side (a) and the image side (b) of the lens holder in the lens unit which concerns on embodiment. It is a perspective view seen from the object side (a) and the image side (b) of the 5th lens body in the lens unit which concerns on embodiment. It is a perspective view seen from the object side (a) and the image side (b) of the adjacent lens (junction lens) in the lens unit which concerns on embodiment. It is a process sectional view which shows the manufacturing method of the lens unit which concerns on embodiment. It is a figure explaining the diaphragm fixing process in the manufacturing method of the lens unit which concerns on embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view of the lens unit 1 according to the present embodiment along the optical axis A. Here, the object (Ob) side is the upper side in the figure, the image (Im) side is the lower side in the figure, and the image sensor 100 is located at the lowermost part in the figure. Each of the lenses L1 to L7 is directly or indirectly fixed to the lens barrel 10. In FIG. 1, a configuration for fixing between each lens or between each lens and the lens barrel 10 is mainly described, and a structure for fixing the positional relationship between the image sensor 100 and the lens barrel 10 is actually described. Is also provided, but the description is omitted. Further, in FIG. 1, the positional relationship between the members is described, and the state of accurate contact between the adjacent members in FIG. 1 will be described later. For this reason, for example, in FIG. 1, it is described that all the members that are not actually in contact with each other or that are in contact with each other only locally are in contact with each other for convenience.

The image sensor 100 is a two-dimensional CMOS image sensor, and each pixel is arranged two-dimensionally in a plane perpendicular to the optical axis A. In reality, the image sensor 100 is covered with a cover glass (not shown). There is. In FIG. 1, a lens unit 1 including a first lens L1 to a seventh lens L7 is configured. The lens unit 1 is configured to form an image of visible light to be imaged on an image pickup device 100 (image plane) in a desired field of view and in a desired form.

In FIG. 1, the first lens L1 provided on the most object side (upper side in the drawing) is a fisheye lens, which mainly determines the field of view of the image pickup apparatus. A second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, and a seventh lens L7 are sequentially arranged on the image sensor 100 side (image side). Each lens has a substantially symmetrical shape around the optical axis A. Further, the diaphragm 20 for limiting the luminous flux is arranged between the fifth lens L5 and the fourth lens L4. Further, a light-shielding plate for actually removing unnecessary light is also provided between the second lens L2 and the third lens L3, but the description thereof is omitted in FIG.

2 (a) is a cross-sectional view taken along the optical axis A of the lens barrel 10 only, and FIG. 2 (b) is a perspective view of the lens barrel 10 viewed from the diagonally upper side (object side) in FIG. On the object side (upper side in the drawing) of the lens barrel 10, a first accommodating portion 10A having a substantially cylindrical inner peripheral surface is provided, and the bottom surface of the first accommodating portion 10A on the image side is the first lens L1. This is the first mounting portion 11 that comes into contact with the lens. Further, on the image side (lower side in the figure) of the first mounting portion 11, a substantially cylindrical cavity portion coaxial with the first accommodating portion 10A and having a smaller diameter than the first accommodating portion 10A. Two accommodating portions 10B are provided, and the bottom surface of the second accommodating portion 10B on the image side is a second mounting portion (mounting surface) 12 that comes into contact with the bonding lens L60 (image side lens described later). The central axis of the first accommodating portion 10A and the second accommodating portion 10B is common and is equal to the optical axis A. Further, as shown in FIG. 2A, the inner peripheral surface of the second accommodating portion 10B is actually gradually reduced from the object side to the image side.

In FIG. 1, the lens surfaces on the object side and the image side (the surface through which the light forming the image passes) in each lens are appropriately curved surfaces (convex curved surface, concave curved surface) so that the lens unit 1 provides desired imaging characteristics. ) It has been processed. Hereinafter, the lens surface on the object side of each lens is referred to as a first surface R1, and the lens surface on the image side is referred to as a second surface R2. Further, as the shape of the lens surface (convex curved surface or concave curved surface), the shape of the first surface R1 means the shape seen from the object side, and the shape of the second surface R2 means the shape seen from the image side. To do.

In general, there are two types of materials constituting a lens in such a small image pickup apparatus: glass and resin material. The former has high mechanical strength but is expensive, and the latter has low mechanical strength but is inexpensive. In addition, since the coefficient of thermal expansion of glass is smaller than that of resin materials, glass is used for lenses in which minute changes in shape and position due to thermal expansion at high temperatures have a large effect on imaging characteristics (changes in focal position, etc.). It is preferably made of. Therefore, in order to make the lens unit 1 high-performance and inexpensive, it is preferable that only the lens made of glass is made of glass and the other lenses are made of resin material.

From this point of view, in the present embodiment, since the first lens L1 arranged on the object side is located on the outermost surface of the image pickup apparatus 1, it is made of glass that is not easily scratched. Further, since the change in the focal length due to the temperature change appears remarkably in the lenses (fourth lens L4 and fifth lens L5) adjacent to the aperture 20, one of them (the fifth lens L5 in the present embodiment). Is made of glass. As the other lens, one made of an inexpensive resin material is used.

The first lens L1 is a negative lens in which the lens surface L1R1 on the object side is a convex curved surface and the lens surface L1R2 on the image side is a concave curved surface. On the upper surface side of the first lens L1, the lens surface L1R1 occupies almost the entire surface. On the lower surface side (image side) of the first lens L1, outside the lens surface L2R2, a first lens first lower surface L1A formed by a plane perpendicular to the optical axis A is provided. Further outside the first lower surface L1A of the first lens, a first lower surface L1B of the first lens located parallel to the first lower surface L1A of the first lens and closer to the object side (upper side in the drawing) than the first lower surface L1A is provided. Further, the outermost peripheral portion of the first lens L1 constitutes a cylindrical first lens outer peripheral surface L1C centered on the optical axis A. Of these surfaces, the lens surfaces L1R1 and L1R2 are optically used, and the other surface is used for fixing the first lens L1 to the lens barrel 10.

In FIG. 1, the upper end side of the lens barrel 10 is a first lens locking portion 13 that is bent toward the optical axis A (center) side so as to restrict the movement of the first lens L1 toward the object side. .. Further, the first lower surface L1A of the first lens comes into contact with the first mounting surface 11 of the lens barrel 10. Therefore, the positional relationship of the first lens L1 with respect to the lens barrel 10 in the optical axis A direction is determined by the first lens locking portion 13 on the object side (upper side in the figure) and first on the image side (lower side in the figure). It is determined by the mounting surface 11. At this time, on the outer side of the first lower surface L1A of the first lens, the gap between the second lower surface L1B of the first lens and the first mounting surface 11 was compressed and elastically deformed in the direction perpendicular to the optical axis A direction. By arranging the ring-shaped O-ring 30, a waterproof function inside the lens barrel 10 can be obtained. The shape of the first lens locking portion 13 as described above is the shape after processing (heat caulking) to fix the first lens l1 to the lens barrel 10, and the upper end of the lens barrel 10 before fixing. As shown in FIG. 2A, the shape of the portion side is such that the first lens L1 can be inserted into the lens barrel 10 from above as shown in FIG.

Further, the outer peripheral surface L1C of the first lens comes into contact with the inner peripheral surface of the first accommodating portion 10A in the lens barrel 10. As a result, the positional relationship between the first lens L1 and the lens barrel 10 in the direction perpendicular to the optical axis A (diameter direction) is determined. That is, according to the above configuration, the first lens L1 is fixed to the lens barrel 10.

The second lens L2 is a negative lens in which the lens surface L2R1 on the object side is a convex curved surface and the lens surface L2R2 on the image side is a concave curved surface. On the object side (upper side in the figure) of the second lens L2, the outer side of the lens surface L2R1 is a plane that is perpendicular to the optical axis A and is located on the image side (lower side in the figure) with respect to the lens surface L2R1. The first upper surface L2A of the lens is provided. Further, on the image side (lower side in the drawing) of the second lens L2, a stepped portion (engagement structure) L2B composed of a surface parallel to the optical axis A and a surface perpendicular to the optical axis A is located outside the lens surface L2R2. Provided. The outer peripheral surface L2C of the second lens, which is the outermost surface of the second lens L2, comes into contact with the inner peripheral surface of the second accommodating portion 10B. The outer peripheral surface L2C of the second lens is formed in a substantially conical surface shape so that the inner diameter around the optical axis A gradually decreases toward the image side. As a result, the positional relationship between the second lens L2 and the optical axis A of the lens barrel 10 in the radial direction is determined.

Further, in the region inside the first mounting portion 11 (the side closer to the optical axis A) and outside the lens surface L1R2 and the lens surface L2R1, the second lens first upper surface L2A and the first lens second lower surface L1B An elastic member 40 which is composed of an elastic body and is thin in the direction of the optical axis A is arranged between them. That is, the first lens L1 and the second lens L2 do not come into direct contact with each other in the direction along the optical axis A, and an elastic member 40 is provided between them.

The third lens L3 is a positive lens in which the lens surface L3R1 on the object side is a concave curved surface and the lens surface L3R2 on the image side is a convex curved surface. On the object side (upper side in the drawing) of the third lens L3, a step portion (engagement structure) L3A formed so as to engage with the step portion L2B of the second lens L2 is provided on the outside of the lens surface L3R1. .. Further, on the image side (lower side in the drawing) of the third lens L3, a stepped portion (engagement structure) L3B composed of a surface parallel to the optical axis A and a surface perpendicular to the optical axis A is located outside the lens surface L3R2. Provided. Further, the outer peripheral surface L3C of the third lens, which is a substantially cylindrical surface forming the outermost outer circumference of the third lens L3, is not in contact with the inner peripheral surface of the second accommodating portion 10B.

The fourth lens L4 is a positive lens in which the surface L4R1 on the object side is a concave curved surface and the surface L4R2 on the image side is a convex curved surface. On the object side (upper side in the drawing) of the fourth lens L4, a step portion (engagement structure) L4A formed so as to engage with the step portion L3B of the third lens L3 is provided on the outside of the lens surface L4R1. .. Further, on the image side (lower side in the drawing) of the fourth lens L4, a stepped portion (engagement structure) L4B composed of a surface parallel to the optical axis A and a surface perpendicular to the optical axis A is located outside the lens surface L4R2. Provided. Further, the outer peripheral surface L4C of the fourth lens, which is a substantially cylindrical surface forming the outermost outer circumference of the fourth lens L4, is not in contact with the inner peripheral surface of the second accommodating portion 10B. That is, the third lens L3 and the fourth lens L4 are not in contact with the lens barrel 10.

As described above, the fifth lens L5 is made of glass, and the surface L5R1 on the object side is a convex curved surface, and the surface L5R2 on the image side is a convex curved surface. Further, the fifth lens L5 is a fifth lens body (lens body) L5A that serves as an optical path and optically functions by the lens surfaces L5R1 and L5R2, and an annular fifth lens body L5A that surrounds the fifth lens body L5A around the optical axis. It is configured by integrating the lens flange portion (flange portion) L5B. The fifth lens flange portion L5B does not serve as an optical path and does not function optically, and is used for positioning the fifth lens L5. The fifth lens L5 is formed by a glass mold in which the fifth lens body L5A and the fifth lens flange portion L5B are integrated.

Further, unlike other lenses, the fifth lens (glass lens) L5 is housed in the lens barrel 10 in a state of being a fifth lens body L50 which is press-fitted and fixed to a lens holder 51 made of a resin material and integrated. Will be done. That is, the fifth lens L5 is treated as a lens in the same state as the third lens L3 and the fourth lens L4 made of the resin material in the state of being the fifth lens body L50.

On the object side (upper side in the drawing) of the fifth lens body L50, a step portion (engagement) formed so as to engage with the step portion L4B of the fourth lens L4 on the outer lens holder 51 of the fifth lens L5. Structure) L50A is provided. On the other hand, also on the image side (lower side in the drawing) of the fifth lens body L50, the outer lens holder 51 of the fifth lens L5 is formed so as to engage with the step portion L6B of the sixth lens L6 described later. A stepped portion (engagement structure) L50B is provided. Further, the outer peripheral surface L50C of the fifth lens body, which is the outermost surface of the fifth lens body L50, comes into contact with the inner peripheral surface of the second accommodating portion 10B. The outer peripheral surface L50C of the fifth lens body is formed in a substantially conical surface shape so that the inner diameter around the optical axis A gradually decreases toward the image side. As a result, the positional relationship between the fifth lens body L50 (fifth lens L5) and the optical axis A of the lens barrel 10 in the radial direction is determined. The detailed structure of the fifth lens body 50 will be described later.

The sixth lens L6 is a negative lens in which the surface L6R1 on the object side is a concave curved surface and the surface L6R2 on the image side is a concave curved surface. The seventh lens L7 is a positive lens having an outer diameter smaller than that of the sixth lens L6, the surface L7R1 on the object side having a convex curved surface, and the surface L7R2 on the image side having a convex curved surface. Further, the sixth lens L6 and the seventh lens L7 are set so as to form a bonded lens (image side lens: adjacent lens) L60 that is closest to the image side by fitting and joining the opposing lens surfaces. Will be done. That is, the image-side lens, which is substantially the most image-side lens, is a junction in which the image-side lens surface L6R2 of the sixth lens L6 and the object-side lens surface L7R1 of the seventh lens L7 are fitted and joined. It becomes the lens L60.

On the object side (upper side in the drawing) of the bonded lens L60 (sixth lens L6), on the outside of the lens surface L6R1, the sixth lens flange portion (adjacent) protruding toward the object side so as to abut the fifth lens flange portion L5B. Lens side flange portion) L6A is provided. Further, a step portion (engagement structure) L6B is provided so as to engage with the step portion L50B of the fifth lens body L50 (lens holder 51).

Further, on the image side (lower side in the drawing) of the bonded lens L60 (sixth lens L6), a bonded lens lower surface L6C which is a plane perpendicular to the optical axis A is provided outside the lens surface L7R2. The lower surface L6C of the bonded lens comes into contact with the second mounting portion (mounting surface) 12. The sixth lens outer peripheral surface L6D, which is the outermost surface of the bonded lens L60 (sixth lens L6), comes into contact with the inner peripheral surface of the second accommodating portion 10B. The outer peripheral surface L6D of the sixth lens is formed in a substantially conical surface shape so that the inner diameter around the optical axis A gradually decreases toward the image side. Therefore, the position of the bonded lens L60 in the direction along the optical axis A is limited by the lens barrel 10 (second mounting portion 12) on the image side. The detailed configuration of the junction lens L60 will be described later.

By engaging the stepped portion L50B formed on the image side of the lens holder 51 with the stepped portion L6B provided on the object side of the sixth lens L6, the lens holder 51A and the junction lens L60 (sixth lens L6) are brought into contact with each other. The positional relationship between the lenses along the optical axis A and the radial direction of the optical axis A is determined. As described above, since the positional relationship between the bonded lens L60 and the lens barrel 10 is determined, the positional relationship between the lens holder 51 and the lens barrel 10 is determined accordingly.

Further, according to the above configuration, the position of the fourth lens L4 in the direction along the optical axis A is such that the step portion L4B and the step portion L50A engage with each other, so that the fifth lens body L50 and the junction lens L60 are placed on the image side. Limited by the lens barrel 10 through. On the other hand, the radial position of the optical axis A of the fourth lens L4 is determined by the inner peripheral surface of the second accommodating portion 10B via the lens holder 51 by engaging the step portion L4B and the step portion L50A. Similarly, the position of the third lens L3 in the direction along the optical axis A is determined by the engagement of the step portion L3B and the step portion L4A via the fourth lens L4, the lens holder 51, and the junction lens L60 on the image side. Is limited by the lens barrel 10. On the other hand, the position of the third lens L3 in the radial direction of the optical axis A is such that the step portion L3B and the step portion L4A engage with each other, so that the inner circumference of the second accommodating portion 10B passes through the fourth lens L4 and the lens holder 51. Determined by the surface.

Further, according to the above configuration, the position of the second lens L2 in the direction along the optical axis A is such that the step portion L2B and the step portion L3A engage with each other, so that the third lens L3 and the fourth lens L4 on the image side. It is limited by the lens barrel 10 via the lens holder 51 and the junction lens L60. On the other hand, the position of the second lens L2 in the radial direction of the optical axis A is determined by the inner peripheral surface of the second accommodating portion 10B as described above.

That is, in the above configuration, of the second lens L2 to the junction lens L60 (seventh lens L7), the second lens L2, the fifth lens L5 (fifth lens body L50), and the junction lens L60 have outer peripheral portions thereof. It is a contact lens that comes into contact with the inner peripheral surface of the second accommodating portion 10B of the lens barrel 10. As a result, these contact lenses have a fixed positional relationship with the lens barrel 10 in the radial direction of the optical axis A. On the other hand, the third lens L3 and the fourth lens L4 are non-contact lenses that do not come into direct contact with the inner peripheral surface of the second accommodating portion 10B. The non-contact lens has the diameter of the optical axis A between the non-contact lens and the contact lens by directly or indirectly engaging with the contact lens on the object side or the image side via the step portion (engagement structure) as described above. By fixing the positional relationship in the direction, the positional relationship with the lens barrel 10 in this direction is fixed. As a result, the positional relationship between all the second lens L2 to the junction lens L60 (seventh lens L7) and the lens barrel 10 in the radial direction of the optical axis A is fixed.

On the other hand, the outer peripheral surfaces of the third lens L3 and the fourth lens L4 are not in contact with the inner peripheral surface of the second accommodating portion 10B. Therefore, it is suppressed that a force is applied to the third lens L3, the fourth lens L4 (lens system), and the lens barrel 10 due to the difference in thermal expansion between the third lens L3, the fourth lens L4, and the lens barrel 10. Will be done. Therefore, distortion of the lens due to the difference in thermal expansion is suppressed, and the adverse effect of the temperature change on the imaging characteristics is reduced.

FIG. 3 is an exploded perspective view of the lens unit 1, and here, a light-shielding plate 21 whose description is omitted in FIG. 1 is also described. Here, the junction lens L60, the fifth lens body L50, the aperture 20, the fourth lens L4, the third lens L3, the shading plate 21, the second lens L2, the elastic member 40, the O-ring 30, and the first lens L1 are shown in the drawing. It is sequentially attached to the lens barrel 10 from the upper side (object side). As shown, the elastic member 40 and the O-ring 30 are annular.

As the material of the lens barrel 10, crystalline plastics (polyethylene, polyamide, polytetrafluoroethylene) having excellent weather resistance are preferably used. On the other hand, the second lens L2, the third lens L3, the fourth lens L4, the sixth lens L6, and the seventh lens L7 are amorphous plastics (polycarbonate, etc.) having excellent lens performance (light transmission and moldability). Consists of. Further, since the lens holder 51 is made of the same amorphous plastic as the fourth lens L4 and the like, the fifth lens body L50 can be treated as a plastic lens similar to the fourth lens L4 and the like as a whole. As described above, the first lens L1 and the fifth lens L5 are made of glass.

In the lens unit 1, in particular, the fifth lens L5 and the structure around it are shaped so as to facilitate maintaining their positional relationship appropriately. This point will be described below. In the above description, the description is mainly based on the structure after assembly of FIG. 1, whereas in the following, each component before assembly will be mainly described. At this time, the optical axis A, the object side, the image side, etc. mean those in the case where each component is arranged in FIG.

FIG. 4 is a perspective view (a) seen from the object side of the fifth lens L5 and a perspective view (b) seen from the image side, and FIG. 5 is a perspective view (a) seen from the object side of the lens holder 51. It is a perspective view (b) seen from the image side, and FIG. 6 is a perspective view (a) seen from the object side of the fifth lens body L50 and a perspective view (b) seen from the image side. Further, FIG. 7 is a perspective view (a) seen from the object side and a perspective view (b) seen from the image side of the bonded lens L60.

As described above, the fifth lens L5 is configured by integrating the fifth lens body L5A and the annular fifth lens flange portion L5B. As shown in FIG. 5, the lens holder 51 is formed with a lens built-in hole 51A that penetrates the lens holder 51 in the direction of the optical axis A. As shown in FIGS. 1 and 6, in the fifth lens L5, the fifth lens outer peripheral surface L5B1 which is the outer peripheral surface of the fifth lens flange portion L5B is the inner peripheral surface of the lens built-in hole 51A in the lens holder 51. It is fixed in contact with the inner peripheral surface 51A1 of the lens holder. However, the inner peripheral surface A1 of the lens holder that comes into contact with the outer peripheral surface L5B1 of the fifth lens does not have to be formed over the entire circumference, and may be formed so that they abut at, for example, three or more locations. Further, the fifth lens L5 is mounted in the lens built-in hole 51A in a light press-fitted state, and the fifth lens L5 is not fixed to the lens holder 51 only by this press-fitting, and an adhesive is used as described later. The positional relationship of the fifth lens L5 with respect to the lens holder 51 in the radial direction of the optical axis A is fixed between them. As described above, since the positional relationship of the lens holder 51 with respect to the lens barrel 10 in the radial direction of the optical axis A is fixed, the positional relationship of the fifth lens L5 with respect to the lens barrel 10 is fixed.

As shown in FIG. 5A, a diaphragm which is a plane perpendicular to the optical axis A formed at equal intervals by being divided into six in the circumferential direction around the lens built-in hole 51A on the object side of the lens holder 51. A mounting surface (object side lens holder surface) 51B is provided. Between the diaphragm mounting surfaces 51B adjacent to each other in the circumferential direction, there is an adhesive groove 51C dug down toward the image side. Further, convex portions 51D are formed on three of the diaphragm mounting surfaces 51B that are evenly spaced. As will be described later, the adhesive groove 51C is used for fixing the fifth lens L5 to the lens holder 51, and the convex portion 51D is used for fixing the diaphragm 20 to the lens holder 51 (fifth lens body L50). In addition, in FIG. 1, the cross section of the part where the adhesive groove 51C is present in the circumferential direction is shown.

Further, as shown in FIG. 1, the image-side surface of the fifth lens flange portion L5B is the object-side surface of the sixth lens flange portion L6A in the bonded lens L60 (sixth lens L6) shown in FIG. Contact with. As a result, the positional relationship of the fifth lens L5 with respect to the junction lens L60 (sixth lens L6) in the direction along the optical axis A is fixed. Further, as described above, since the positional relationship of the bonded lens L60 with respect to the lens barrel 10 in the direction along the optical axis A is fixed, this causes the fifth lens L5 to be in the direction along the optical axis A with respect to the lens barrel 10. The positional relationship is fixed.

In this structure, the fifth lens L5 and the junction lens L60 come into direct contact with each other in the direction along the optical axis A without interposing other members, so that the positional relationship between the fifth lens L5 and the junction lens L60 (Interval) is precisely determined. At this time, the position of the bonding lens L60 is determined by directly contacting the lens barrel 10 (second mounting portion 12) with the lens barrel 10 in the direction along the optical axis A without using other members. The positional relationship between the lens L60 and the lens barrel 10 in the direction along the optical axis A is also precisely determined. Therefore, the positional relationship (interval) between the fifth lens L5, the junction lens L60, and the lens barrel 10 in the direction along the optical axis A can be determined particularly precisely.

Further, in this structure, the positional relationship between the fifth lens L5, the bonding lens L60, and the lens barrel 10 in the direction along the optical axis A is precisely defined as described above, and the lens barrel 10 has a position. 5 It is necessary to fix the lens L5 to the lens holder 51 with an adhesive or the like. The manufacturing method for this can be easily carried out as described below. FIG. 8 is a process sectional view schematically showing this manufacturing method. This cross section corresponds to the cross section in FIG.

First, as shown in FIG. 8A, the lens holder 51 is arranged on the bonded lens L60, and the positioning between them is performed between the stepped portion L50B on the lens holder 51 side and the stepped portion L6B on the bonded lens L60 side. It is performed by engaging with (lens holder positioning process). Thereby, the positional relationship between the lens holder 51 and the junction lens L60 is determined.

In this state, as shown in FIG. 8B, the fifth lens L5 is incorporated into the lens incorporating hole 51A from the upper side (object side). At this time, the fifth lens L5 can be pushed in from above until the fifth lens flange portion L5B comes into contact with the sixth lens flange portion L6A of the bonded lens L60 (lens insertion step). As a result, the positional relationship between the junction lens L60 and the fifth lens L5 in the direction along the optical axis A is determined. Further, the positional relationship of the optical axis A between the fifth lens L5 and the lens holder 51 in the radial direction is determined by the lens built-in hole 51A. However, in this state, the fifth lens L5 is lightly press-fitted into the lens holder 51, so that it is not fixed.

In this state, as shown in FIG. 8C, if an appropriate amount of the adhesive before solidification is put into the adhesive groove 51C, the adhesive layer 200 is formed in the adhesive groove 51C. It can be formed so as to be in contact with the inner fifth lens flange portion L5B and fill the gap between the inner peripheral surface of the lens incorporating hole 51A and the outer peripheral surface of the fifth lens flange portion L5B. After that, by solidifying the adhesive layer 200, the fifth lens L5 and the lens holder 51 properly maintained the positional relationship between the lens holder 51 and the bonding lens L60 and the positional relationship between the fifth lens L5 and the bonding lens L60. It is fixed in the state (adhesion process). After that, as shown in FIG. 8D, the diaphragm 20 is fixed to the fifth lens body L50 in this state (aperture fixing step).

FIG. 9 is a perspective view illustrating a diaphragm fixing step, showing a situation (a) before mounting the diaphragm 20 and a situation (b) after mounting. The thin flat diaphragm 20 is formed with three positioning holes 20A penetrating the aperture 20 in the direction of the optical axis A so as to correspond to the convex portion 51D on the outside of the central opening 20B. Therefore, the positioning hole 20A can be engaged with the convex portion 51D, and the diaphragm 20 can be fixed in a state of being mounted on the diaphragm mounting surface 51B. At this time, for example, the diaphragm 20 is fixed to the lens holder 51 (fifth lens body L50) by melting the convex portion 51D protruding from the positioning hole 20A toward the object side after mounting the diaphragm 20 and fusing it with the surroundings. Can be done. In FIG. 1, the diaphragm 20 is provided perpendicular to the optical axis A, and when this angle fluctuates, ghosts may occur in the image pickup apparatus. On the other hand, with such a configuration, the diaphragm 20 is fixed to the fifth lens body L50 in an appropriate manner, and the angle of the diaphragm 20 with respect to the optical axis A is suppressed from fluctuating. In the above example, the convex portion 51D has a circular shape, but more generally, the length of the positioning hole 20A along the circumferential direction around the optical axis A includes the case where this shape is not circular. , It may be set longer than the length of the convex portion 51D along the same direction. This facilitates the work of attaching the diaphragm to the lens holder, and does not cause an adverse effect on the imaging characteristics.

Next, as shown in FIG. 8 (e), after the diaphragm 20 is fixed in this way, the structure of FIG. 8 (d) is press-fitted into the lens barrel 10 and fixed (lens assembly fixing). Process). At this time, as described above, the lower surface L6C of the bonded lens is in contact with the second mounting portion (mounting surface) 12, and the outer peripheral surface L6D of the sixth lens is in contact with the inner peripheral surface of the second accommodating portion 10B. , The positional relationship of the bonded lens L60 with respect to the lens barrel 10 is determined. Further, in the lens holder 51, the positional relationship of the optical axis A with the lens barrel 10 in the radial direction is determined by the contact of the outer peripheral surface L50C of the fifth lens body with the inner peripheral surface of the second accommodating portion 10B. By engaging the stepped portion L50B and the stepped portion L6B, the positional relationship between the bonding lens L60 in the direction along the optical axis A and the radial direction of the optical axis A is determined. Therefore, this determines the positional relationship between the lens barrel 10, the junction lens L60, the fifth lens L5, the lens holder 51, and the aperture 20.

According to the above manufacturing method, particularly when the bonded lens L60 and the fifth lens body L50 are press-fitted (FIG. 8 (e)), the fifth lens body L50 (lens holder 51) and the bonded lens L60 are between the bonded lens L60. It is suppressed that the positional relationship and the positional relationship between the fifth lens L5 and the bonded lens L60 are out of order, or the lens holder 51 is prevented from coming off the bonded lens L60, and the positional relationship between them is maintained properly. Dripping.

The fourth lens L4 in FIG. 1 is mounted on the upper side of the fifth lens body L50 so as to engage the step portion L4B and the step portion L50A in the state of FIG. 8 (e), thereby causing the fifth lens body. The positional relationship with L50 is fixed. After that, the members of the third lens L3 and above shown in FIG. 3 can also be sequentially mounted in a state where the positional relationship with each other is fixed. Finally, after the first lens L1 is attached to the lens barrel 10 after the elastic member 40 and the O-ring 30 are arranged, the first lens locking portion 13 is caulked as shown in FIG. Once formed, all the components are fixed to the lens barrel 10 and the lens unit 1 is obtained.

In the lens unit 1, in particular, the positional relationship between the fifth lens L5, which is a glass lens, and a lens and a lens barrel adjacent thereto is maintained with high accuracy at the time of manufacture. Therefore, good imaging characteristics can be obtained.

In the above example, the fifth lens L5 is a glass lens, and the fifth lens flange portion (flange portion) L5B provided in the glass lens and the junction lens (adjacent lens) L60 adjacent to the image side thereof. The positional relationship between the fifth lens and the junction lens L60 in the direction along the optical axis A is determined by the contact between the sixth lens flange portion (adjacent lens side flange portion) L6A flange portion. On the contrary, such a configuration may be applied between the glass lens and the lens adjacent to the object side (the fourth lens L4 in the above example). Even in such a case, the positional relationship (interval) between the glass lens, the fourth lens, and the lens barrel in the direction along the optical axis can be determined particularly precisely.

However, when the mounting surface (second mounting portion 12) that supports the lens system on the lens barrel side is formed so as to face the object side on the image side as described above, it is shown in FIG. 8 (e). As a result, when the entire structure of FIG. 8D is press-fitted into the lens barrel 10, when a force is applied to the image side of the entire structure, the glass lens (fifth lens L5) becomes It is always locked by the adjacent lens side flange portion (sixth lens flange portion L6A). Therefore, even if a large force is applied to the glass lens during this operation, the glass lens is prevented from falling off from the lens holder. On the other hand, when the above structure is applied between the glass lens and the adjacent lens on the object side and the glass lens, the glass lens and the adjacent lens side flange portion are separated from each other, contrary to the above case. Since a force that causes the glass lens to act may act, the glass lens is more likely to fall off than in the above case. For this reason, the above example in which the above configuration is applied between the glass lens and the adjacent lens adjacent to the image side and the glass lens is particularly preferable. However, if there is no risk of the glass lens falling off, such as when the adhesion between the glass lens and the lens holder is strong, the above configuration is provided between the glass lens and the adjacent lens adjacent to the object side and the glass lens. May be applied.

Further, in the above example, the diaphragm 20 is fixed to the fifth lens body L50 (lens holder 51), but the method of fixing the diaphragm in the lens unit is arbitrary. Even when the diaphragm is not fixed to the lens holder, the above manufacturing method can be applied in the same manner.

Further, in the above example, the lens surface L5R2 on the image side (adjacent lens side) of the fifth lens L5 is a convex curved surface, and the lens surface L6R1 on the object side (glass lens side) of the junction lens L60 is a concave curved surface. The shapes of the flange portion on the glass lens side and the flange portion on the adjacent lens side on the adjacent lens side are appropriately set according to these shapes, and the overall shape of the glass lens and the adjacent lens is set accordingly. Further, the structure for determining the positional relationship between the glass lens, the adjacent lens, and the lens holder as described above and the structure other than the optically functioning portion are arbitrary.

(Main features of this form)
The features of this embodiment are briefly summarized as follows.
(1) The lens unit 1 is arranged along the optical axis A from the object (Ob) side to the image (Im) side with the first lens L1 which is the most object side and the image side of the first lens L1. A plurality of lenses are laminated and fixed to the lens barrel, and one of the plurality of lenses is a lens body L5A configured to include an optical path and a diameter seen from the optical axis A of the lens body L5A. The flange portion L5B formed on the outer side in the direction is a glass lens L5 made of glass integrally formed, and the glass lens L5 is supported on the outer side in the radial direction by a lens holder 51 made of a resin material. The two adjacent lenses (fourth lens L4 and junction lens L60), which are housed inside the lens barrel 10 and adjacent to the glass lens L5 in the direction along the optical axis A, come into contact with the lens holder 51. The positional relationship with the glass lens L5 in the direction along the optical axis A is determined by, and one of the two adjacent lenses (junction lens L60) comes into contact with the flange portion L5B to form a contact with the glass lens L5. The positional relationship between the lenses in the direction along the optical axis A is defined.

In this configuration, the glass lens L5 is fixed in the lens barrel 10 while being supported by the lens holder 51, and is adjacent to the glass lens L5 on the object side and the image side in the direction along the optical axis A. (4th lens L4, bonded lens L60) both come into contact with the lens holder 51. However, one of the adjacent lenses (junction lens L60) is in direct contact with the flange portion L5B of the glass lens L5, so that the positional relationship with the glass lens L5 in the direction along the optical axis A is determined. Thereby, the positional relationship between the adjacent lens (junction lens L60) and the glass lens L5 can be determined particularly precisely. Further, the glass lens L5 having such a shape can be easily manufactured by a glass mold.

(2) The one adjacent lens (junction lens L60) is formed in an annular shape on the outer side in the radial direction from the lens surface so as to abut on the flange portion L5B and to protrude from the lens surface on the glass lens L5 side. It is provided with a flange portion L6A on the adjacent lens side.

In this case, in the adjacent lens L60 on the side that directly contacts the glass lens L5, the adjacent lens side flange portion L6A for locking the glass lens L5 is formed without affecting the lens surface. When the adjacent lens L60 is made of a resin material, such a shape can be easily formed by molding.

(3) One of the lens holder 61 and the one adjacent lens L60 is press-fitted and fixed to the lens barrel 10, and the other one of the lens holder 51 and the one adjacent lens L60 is said. By engaging the engaging structures (L50B, L6B) formed with each other with one, the mutual positional relationship in the radial direction is determined.

In this case, one of the adjacent lenses that are in direct contact with the lens holder 51 and the glass lens L5 is in contact with the inner surface of the lens barrel 10. On the other hand, the position of the other one in the radial direction is determined by engaging the engaging structure (L50B, L6B) with this one. Thereby, the positional relationship in the radial direction between the glass lens L5 and the adjacent lens L60 can be precisely determined.

(4) One adjacent lens (L60) is arranged on the image side of the glass lens L5, is press-fitted and fixed to the lens barrel 10, and has an engaging structure (L50B) formed with the lens holder 51. , L6B) are engaged with each other to determine the positional relationship in the radial direction with respect to the lens holder 51.
In this case, the adjacent lens on the side that directly contacts the glass lens L5 is the adjacent lens (junction lens) L60 on the image side. In this case, when the manufacturing method described later is executed, the force in the direction of separating the glass lens L5 and the adjacent lens L60 is suppressed, and the glass lens L5 is particularly suppressed from falling off from the lens holder 51 during assembly. Will be done.

(5) The lens holder 51 has a lens built-in hole 51A which is a through hole along the optical axis A and to which the glass lens L5 is mounted, and an object side lens which is a plane perpendicular to the optical axis A formed on the object side. The holder surface 51B and the adhesive groove 51C, which are a plurality of grooves locally dug from the lens holder surface 51B on the object side around the lens incorporating hole 51A so as to be connected to the lens incorporating hole 51A on the object side, An adhesive layer 200 for fixing the glass lens L5 and the lens holder 51 is formed in the groove 51C for adhesive.
In this case, the adhesive in the adhesive groove 51C can be used to firmly fix the glass lens L5 and the lens holder 51, and this work becomes easy.

(6) A diaphragm 20 is provided between the other of the two adjacent lenses (fourth lens L4) and the glass lens L5, and the diaphragm 20 has a plurality of positioning holes 20A in the circumferential direction around the optical axis A. Is formed, and on the object side of the lens holder 51, a plurality of convex portions 51D protruding from the object side lens holder surface 51B toward the object side are formed corresponding to the positioning holes 20A, and the diaphragm 20 positions the convex portions 51D. It is mounted on the lens holder 51 in a state of being engaged with the hole 20A and locked to the lens holder surface 51B on the object side.
In this case, since the aperture 20 is also fixed to the lens holder 51, the positional relationship between the glass lens 51 and the aperture 20 is precisely determined. In addition, the work of mounting the diaphragm 20 is also easy.

(7) In the method of manufacturing the lens unit 1, a lens in which a lens holder 51 is arranged with an engaging structure (L50B, L6B) formed of each other engaged with one of the adjacent lenses L60. The holder positioning step, the lens inserting step of inserting the glass lens L5 into the lens incorporating hole 51A in the lens holder 51 after the lens holder positioning step, and the adhesive before solidification are put into the adhesive groove 51C after the lens inserting step. It includes a bonding step of solidifying the lens, and a lens assembly fixing step of press-fitting and fixing the structure in which the adjacent lens L60, the lens holder 51, and the glass lens L5 are integrated after the bonding step to the lens barrel 10.
In this case, after the positional relationship between the adjacent lens L60 on the side that directly contacts the glass lens L5 and the lens holder 51 is determined by the lens holder positioning step, the glass lens L5 and the adjacent lens L60 are separated from each other. The positional relationship is determined in the lens insertion step, and then the glass lens L5 and the lens holder 51 are fixed by the bonding step. After that, when the adjacent lens L60, the lens holder 51, and the glass lens L5 are integrated and press-fitted into the lens barrel 10, the positional relationship between them is maintained and the lens L5 falls off from the lens holder 51. Is suppressed.

(8) In the method for manufacturing the lens unit 1 according to the present invention, the lens holders 51 are engaged with each other formed engaging structures (L50B, L6B) with the adjacent lens L60. The lens holder positioning step for arranging, the lens insertion step for inserting the glass lens L5 into the lens incorporating hole 51A in the lens holder 51 after the lens holder positioning step, and the adhesive before solidification in the adhesive groove 51C after the lens insertion step. The aperture 20 is placed on the lens holder surface 51B on the object side in a state where each of the plurality of positioning holes 20A is engaged with each of the plurality of convex portions 51D in the lens holder 51 after the bonding step. A lens set in which the aperture fixing step of mounting and fixing and the structure in which the adjacent lens L60, the lens holder 51, the glass lens L5, and the aperture 20 are integrated after the aperture fixing step are press-fitted and fixed to the lens barrel 10. It includes a fixing process.
Also in this case, similarly to the above-mentioned manufacturing method, when the adjacent lens L60, the lens holder 51, and the glass lens L5 are integrally press-fitted and fixed to the lens barrel 10, the positional relationship between them is maintained. Moreover, the lens L5 is prevented from falling off from the lens holder 51. At this time, the diaphragm 20 is also fixed in this, and the positional relationship between the glass lens L5 and the diaphragm 20 is precisely determined.

The present invention has been described based on an embodiment and a modification thereof, but this embodiment is an example, and various modifications can be made to the combination of each component thereof, and such a modification is also described in the present invention. It will be understood by those skilled in the art that it is within the scope of the invention.

1 Lens unit 10 Lens barrel 10A 1st accommodating part 10B 2nd accommodating part 11 1st mounting part 12 2nd mounting part (mounting surface)
13 1st lens locking part 20 Aperture 20A Positioning hole 20B Aperture 21 Shading plate 30 O ring 40 Elastic member 51 Lens holder 51A Lens built-in hole 51A1 Lens holder inner peripheral surface 51B Aperture mounting surface (object side lens holder surface)
51C Adhesive groove 51D Convex part 100 Image sensor A Optical axis Im image (side)
L1 1st lens L1A 1st lens 1st lower surface L1B 1st lens 2nd lower surface L1C 1st lens outer peripheral surface L2 2nd lens L2A 2nd lens 1st upper surface L2B, L3A, L3B, L4A, L4B, L50A, L50B, L6B Step part (engagement structure)
L2C 2nd lens outer peripheral surface L3 3rd lens L3C 3rd lens outer peripheral surface L4 4th lens L4C 4th lens outer peripheral surface L5 5th lens (glass lens)
L5A 5th lens body (lens body)
L5B 5th lens flange part (flange part)
L5B1 5th lens outer peripheral surface L6 6th lens L6A 6th lens flange part (adjacent lens side flange part)
L6C Bonded lens lower surface L6D 6th lens outer peripheral surface L7 7th lens L50 5th lens body L50C 5th lens body outer peripheral surface L60 Bonded lens (image side lens)
Ob object (side)
R1 first surface R2 second surface

Claims (8)

A lens in which the first lens, which is the most object side, and a plurality of lenses arranged on the image side of the first lens are laminated and fixed to the lens barrel along the optical axis from the object side to the image side. It ’s a unit,
In one of the plurality of lenses, a lens body configured to include an optical path and a flange portion formed on the outer side of the lens body in the radial direction with respect to the optical axis are integrated. It is a glass lens made of formed glass,
The glass lens is supported inside the lens barrel by a lens holder made of a resin material and is housed inside the lens barrel.
The two adjacent lenses, which are the lenses adjacent to each other in the direction along the optical axis, are brought into contact with the lens holder so that the positional relationship between the glass lens and the glass lens in the direction along the optical axis is changed. Fixed,
Moreover, one of the two adjacent lenses is a lens unit characterized in that a positional relationship with the glass lens in a direction along the optical axis is determined by abutting against the flange portion. The one adjacent lens is formed in an annular shape on the outer side in the radial direction from the lens surface so as to abut on the flange portion and protrude from the lens surface on the glass lens side. The lens unit according to claim 1, further comprising a portion. One of the lens holder and the one adjacent lens is press-fitted and fixed to the lens barrel.
The other one of the lens holder and the one adjacent lens has the mutual positional relationship in the radial direction by engaging the engaging structures formed with each other with the one. The lens unit according to claim 1 or 2, wherein the lens unit is defined. The one adjacent lens is arranged on the image side of the glass lens, is press-fitted and fixed to the lens barrel, and engages with each other formed engaging structures with the lens holder. The lens unit according to claim 3, wherein the positional relationship in the radial direction with respect to the lens holder is determined by the lens holder. The lens holder has a lens built-in hole which is a through hole along the optical axis and on which the glass lens is mounted, and an object-side lens holder surface which is a plane perpendicular to the optical axis formed on the object side. An adhesive groove, which is a plurality of grooves locally dug from the lens holder surface on the object side, is provided around the lens incorporating hole so as to be connected to the lens incorporating hole on the object side.
The lens unit according to claim 4, wherein an adhesive layer for fixing the glass lens and the lens holder is formed in the adhesive groove. A diaphragm is provided between the other of the two adjacent lenses and the glass lens.
A plurality of positioning holes are formed in the diaphragm in the circumferential direction around the optical axis.
On the object side of the lens holder, a plurality of convex portions projecting from the object side lens holder surface toward the object side are formed corresponding to the positioning holes.
The lens unit according to claim 5, wherein the diaphragm is mounted on the lens holder in a state where the convex portion is engaged with the positioning hole and is locked to the lens holder surface on the object side. .. The method for manufacturing a lens unit according to claim 5.
A lens holder positioning step of arranging the lens holders with respect to the one adjacent lens in a state where the engaging structures formed are engaged with each other.
A lens insertion step of inserting the glass lens into the lens incorporating hole in the lens holder after the lens holder positioning step.
An adhesive step in which the adhesive before solidification is poured into the adhesive groove after the lens insertion step to solidify the adhesive.
A lens assembly fixing step of press-fitting and fixing the structure in which the one adjacent lens, the lens holder, and the glass lens are integrated to the lens barrel after the bonding step.
A method for manufacturing a lens unit, which comprises the above. The method for manufacturing a lens unit according to claim 6.
A lens holder positioning step of arranging the lens holders with respect to the one adjacent lens in a state where the engaging structures formed are engaged with each other.
A lens insertion step of inserting the glass lens into the lens incorporating hole in the lens holder after the lens holder positioning step.
An adhesive step in which the adhesive before solidification is poured into the adhesive groove after the lens insertion step to solidify the adhesive.
A diaphragm fixing step of placing and fixing the diaphragm on the object-side lens holder surface in a state where each of the plurality of positioning holes is engaged with each of the plurality of convex portions of the lens holder after the bonding step. When,
A lens assembly fixing step of press-fitting and fixing the structure in which the one adjacent lens, the lens holder, the glass lens, and the diaphragm are integrated to the lens barrel after the diaphragm fixing step.
A method for manufacturing a lens unit, which comprises the above.