JP2020030335A - Lens unit - Google Patents

Abstract

To provide a lens unit the lens barrel of which is composed of an inside cylindrical part and an outside cylindrical part, in which assembly work is simplified and reduced in cost without causing an increase in component counts while suppressing the occurrence of shrinkage cavities during resin molding, even when a structure for attaching other members is provided.SOLUTION: The lens unit comprises a wide angle lens composed of a plurality of lenses and a lens barrel 3. The lens barrel 3 includes an inside cylindrical part 31 for accommodating the wide angle lens, an outside cylindrical part 32 separated from the inside cylindrical part 31 toward the radial outside, and a plurality of ribs 40 extending in radial form from an outer circumferential surface 31a of the inside cylindrical part 31 toward the radial outside. There are two types of ribs 40: a rib 41 for locking that has a positioning part 42 at an edge of an image side L2 and locks an electronic member 99 in position and a basic rib 43 not provided with the positioning part 42.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a lens unit, for example, to a lens unit including a plurality of lenses and a lens barrel that holds the plurality of lenses.

  A lens unit including a lens barrel that holds a plurality of lenses is arranged on the object side of a counterpart member such as a substrate on which an image sensor is mounted. In recent years, in the lens unit market, demands for higher resolution have been increasing, and simplification and cost reduction of assembly work by reducing the number of parts have been demanded.

  Various techniques are known as techniques for holding a substrate such as an image sensor (for example, see Patent Documents 1 and 2). In the technique disclosed in Patent Document 1, a cylindrical imaging element holder is fitted on the outer peripheral surface of a lens holder by a screw mechanism. In the technique disclosed in Patent Literature 2, positioning is performed by fitting a mating member (circuit board) into a support provided at an image side end of a lens holder.

WO 2015/119296 International Publication No. WO2018 / 062298

  By the way, in the technique disclosed in Patent Document 1, the lens holder and the imaging element holder are formed as separate members. In the technique disclosed in Patent Document 2, although the mating member is positioned by the support portion, since the thickness of the support portion is large, sink occurs at the time of resin molding, and the accuracy of the support portion cannot be increased. There was a problem that it was not possible to meet the demand for higher resolution.

  The present invention has been made in view of the above circumstances, and in a lens unit including a lens barrel holding a plurality of lenses, a structure is provided in which sinking during resin molding is suppressed and other members are attached. Even in such a case, it is an object of the present invention to provide a technique capable of simplifying the assembly work and reducing the cost without increasing the number of parts.

  The lens unit of the present invention includes a plurality of lenses, an inner cylindrical portion in which the plurality of lenses are housed, an outer cylindrical portion radially outwardly spaced from the inner cylindrical portion, the inner cylindrical portion, and the outer cylindrical portion. And a plurality of ribs extending radially between the lens barrel, and at least one of the plurality of ribs has a positioning portion for positioning with an opposing member on an image-side end surface. It is a rib for. By forming a plurality of ribs between the inner tubular portion and the outer tubular portion, a function as a thinning between the inner tubular portion and the outer tubular portion is provided. As a result, sink marks during resin molding can be suppressed, and molding accuracy of the lens barrel can be improved. That is, the resolution of the lens unit can be further increased. In addition, since the rib has a locking rib provided with a positioning portion for positioning with another member, simplification and cost reduction of the assembling work by reducing the number of parts can be achieved.

  The plurality of ribs may be separated between an outer peripheral surface of the inner cylindrical portion and an inner peripheral surface of the outer cylindrical portion.

  The plurality of ribs may extend radially outward from an outer peripheral surface of the inner cylindrical portion, and an annular groove may be formed between the plurality of ribs and the outer cylindrical portion. Since the inner tubular portion is reinforced by the plurality of ribs, the strength of the inner tubular portion is ensured.

  The plurality of ribs may extend radially inward from the inner peripheral surface of the outer cylindrical portion, and an annular groove may be formed between the plurality of ribs and the inner cylindrical portion. . Since the annular groove is formed between the plurality of ribs and the inner cylindrical portion and the rib and the inner cylindrical portion are not connected, the deformation of the inner cylindrical portion due to the rib does not occur. Therefore, the wide-angle lens can be more accurately held on the inner cylindrical portion, and the resolution of the lens unit can be further increased. Further, since the plurality of ribs extend radially inward from the inner peripheral surface of the outer tubular portion, the strength of the outer tubular portion can be improved.

  The positioning portion may include a mounting surface on which the mating member is mounted, and a protruding portion that regulates a position in a radial direction.

  The inner peripheral surface of the inner cylindrical portion includes a plurality of centering protrusions protruding radially inward, and each of the plurality of centering protrusions is adjacent ribs of the plurality of ribs. May be formed between them. If the rib extends radially outward from the outer peripheral surface of the inner cylinder, the resin forming the inner cylinder is pulled toward the rib during resin molding, and the accuracy of the inner peripheral surface of the inner cylinder near the rib is reduced. It may be difficult to put out. Therefore, even if the resin forming the inner cylindrical portion is pulled toward the ribs during molding, by forming the centering protrusion between the adjacent ribs having little influence, it is possible to suppress the decrease in accuracy due to the above. Therefore, the resolution of the lens unit can be increased.

  The shape of the mating member may be substantially rectangular, and the plurality of ribs may be formed at eight or more locations. In the case where the mating member is substantially rectangular, the positioning accuracy can be improved by using eight or more ribs so that positioning can be performed at the center or near the corner of the side of the mating member.

  According to the present invention, in the lens unit, by forming a plurality of ribs between the inner cylindrical portion and the outer cylindrical portion, a function is provided as lightening between the inner cylindrical portion and the outer cylindrical portion, and resin molding is performed. The occurrence of sink marks at the time can be suppressed, and the molding accuracy of the lens barrel can be improved. In addition, since the rib has a locking rib provided with a positioning portion for positioning with another member, simplification and cost reduction of the assembling work by reducing the number of parts can be achieved.

FIG. 2 is a diagram illustrating the entire lens unit according to the first embodiment. FIG. 2 is a longitudinal sectional view (YZ sectional view) of the lens unit according to the first embodiment. FIG. 2 is a perspective view of a lens barrel according to the first embodiment. FIG. 2 is a perspective view of the lens barrel according to the first embodiment as viewed from the bottom surface side. FIG. 3 is a bottom view of the lens barrel according to the first embodiment. FIG. 2 is a longitudinal sectional view (YZ sectional view) of the lens barrel according to the first embodiment. It is a longitudinal section perspective view of a lens barrel concerning a 1st embodiment. It is a cross section perspective view of a lens barrel concerning a 1st embodiment. FIG. 7 is an enlarged view of a region A1 in FIG. 6 according to the first embodiment. FIG. 3 is a cross-sectional view of an inner tube portion of the lens barrel according to the first embodiment. It is the figure which expanded the area | region A2 of FIG. 10 concerning 1st Embodiment. FIG. 3 is a diagram illustrating a mold manufacturing process according to the first embodiment. It is a bottom view of a lens barrel concerning a 2nd embodiment. It is a bottom view of a lens barrel concerning a 3rd embodiment.

<First embodiment>
Hereinafter, embodiments for carrying out the invention (hereinafter, referred to as “embodiments”) will be described with reference to the drawings. FIG. 1 is a view showing the entire lens unit 1 according to the present embodiment, wherein FIG. 1A is a front view and FIG. 1B is a perspective view. FIG. 2 is a longitudinal sectional view, which corresponds to a YZ section in the drawing.

  The lens unit 1 is a lens assembly incorporated in an in-vehicle peripheral monitoring camera, a monitoring camera, a door phone, and the like. The “object side L1” and the “image side L2” in the present embodiment refer to the object side and the image side in the optical axis L direction, and the “optical axis direction” refers to a direction parallel to the optical axis L.

(overall structure)
The lens unit 1 includes a lens group 2 in which a plurality of disc-shaped lenses are arranged coaxially, and a lens barrel 3 that houses the lens group 2. For example, as shown in FIG. 2, the lens group 2 includes a first lens 21, a second lens 22, and a third lens 23 which are arranged in close contact from the object side L <b> 1 to the image side L <b> 2 along the optical axis L. The fourth lens 24, the fifth lens 25, and the sixth lens 26 are configured by six lenses.

  Among the lenses constituting the lens group 2, the first lens 21 is disposed closest to the object side L1. The second lens 22 is located on the image side L2 of the first lens 21. The third lens 23 is located on the image side L2 of the second lens 22. The fourth lens 24 is located on the image side of the third lens 23. The fourth lens 24 is disposed in the lens barrel 3 in a state where it is press-fitted and fixed to the lens holder 4 made of resin and further reinforced and fixed by an adhesive. The fifth lens 25 is located on the image side L2 of the fourth lens 24. The sixth lens 26 is located on the image side L2 of the fifth lens 25. The fifth lens 25 and the sixth lens 26 are cemented lens elements, respectively, and constitute a cemented lens. A light-shielding sheet 27 is provided between the second lens 22 and the third lens 23, and a diaphragm 28 is provided between the third lens 23 and the fourth lens 24.

  The first lens 21 includes a glass lens from the viewpoint that the object side lens surface of the first lens 21 is hardly damaged even when the object side lens surface of the first lens 21 located closest to the object side is exposed. Used. For the second lens 22, the third lens 23, the fifth lens 25, and the sixth lens 26, plastic lenses are used because they are excellent in lens workability and economic efficiency. A glass lens is used for the fourth lens 24 from the viewpoint of excellent optical characteristics such as surface accuracy of the lens and refractive index with respect to temperature change.

  The outer peripheral surface of the cemented lens composed of the first lens 21, the second lens 22, the third lens 23, the lens holder 4, the fifth lens 25 and the sixth lens 26 constituting the lens group 2 has a lens barrel 3 It is positioned in the optical axis L direction by being supported by the inner peripheral surface 60 of the (inner cylindrical portion 31).

  The flat portion 25a formed on the periphery of the image side L2 surface of the fifth lens 25 is placed on the annular flat portion 61 extending inward in the circumferential direction on the image side L2 of the lens barrel 3. A fourth lens 24, a third lens 23, and a second lens 22 are sequentially arranged thereon. Thereafter, the peripheral edge of the object-side L1 surface of the second lens 22 is locked by a caulking portion 35 provided at the end of the inner peripheral surface 60 of the lens barrel 3 on the object-side L1.

  In this way, the second lens 22, the third lens 23, the lens holder 4 (the fourth lens 24), and the fifth lens 25 (and the sixth lens 26 joined thereto) are positioned in the optical axis L direction. Here, from the viewpoint of preventing the insertion order of the second lens 22, the third lens 23, the lens holder 4 (the fourth lens 24), and the fifth lens 25 from being erroneously inserted, the outer diameter of the lens on the image side L2 is smaller, and , The inner peripheral surface is formed narrow.

  A sixth lens accommodating portion 69 is formed at the end (bottom surface) of the image side L2 of the inner peripheral surface 60, and an opening 69a is formed at the center of the bottom thereof, so that the image side lens surface of the sixth lens 26 is formed. It is exposed on the image side L2. An infrared cut filter 38 is attached to the image side L2 from the opening 69a at a position not in contact with the sixth lens 26. Further, an image sensor or the like is provided on the image side L2 of the infrared cut filter 38 by a locking rib 41 described later. The electronic member 99 which is a mating member provided with is positioned.

  After arranging the O-ring 5 in the concave portion 64 of the step formed on the upper surface of the lens barrel 3, the first lens 21 is disposed above the step. At this time, the first lens 21 is mounted on the receiving portion 34 formed in the step portion via the spacer 39 as necessary.

  After the position of the first lens 21 in the radial direction is adjusted, the peripheral end of the first lens 21 is caulked from the object side L1 by the caulking portion 36 formed at the end of the lens barrel 3 on the object side L1. Thereby, the first lens 21 is positioned in the optical axis L direction. The O-ring 5 is compressed and sealed by the pressing force on the image side L2 at this time. Thereby, invasion of water or the like from the outside is suppressed.

  Although the lens group 2 of the lens unit 1 in the present embodiment is constituted by the six lenses, the number of lenses is not limited, and the material of the lenses is not limited. Further, a configuration without a cemented lens may be adopted.

(Characteristics of lens barrel structure)
Subsequently, the structure of the lens barrel 3 will be described focusing on the characteristic portions of the present embodiment. FIG. 3 is a perspective view of the lens barrel 3, showing the lens unit 2 removed from the perspective view of the lens unit 1 of FIG. 1B. FIG. 4 is a perspective view of the lens barrel 3 as viewed from the bottom side. FIG. 5 is a bottom view of the lens barrel 3. FIG. 6 is a sectional view of the lens barrel 3 taken along the line YZ, and shows the lens unit 1 of FIG. 2 with the lens group 2 removed. FIG. 7 is a sectional perspective view (XZ section) of the lens barrel 3. FIG. 8 is an XY cross-sectional perspective view.

  The lens barrel 3 is a cylindrical lens frame made of resin. An inner peripheral surface 60 is formed along the outer peripheral surface of each lens constituting the lens group 2 toward the image side L2. More specifically, the lens barrel 3 includes an inner cylindrical portion 31 on which an inner peripheral surface 60 is formed, an outer cylindrical portion 32 radially outwardly separated from the inner cylindrical portion 31, and an outer peripheral surface 31a of the inner cylindrical portion 31. (Here, twelve) ribs 40 radially outwardly extending from the outside.

  In the present embodiment, the end 33 of the outer cylindrical portion 32 on the image side L2 has a substantially square outer shape when viewed from above. As shown in FIG. 5, on the end 33 of the outer cylindrical portion 32, gate marks G indicating that the gate position (gate opening) was at the time of resin molding are formed at a total of four places at the center of each side. I have.

  In the present embodiment, the lens barrel 3 is formed by injection molding. The injection position of the resin (gate mark G shown in FIG. 5) when the lens barrel 3 is injection-molded is apart from the inner cylindrical portion 31. According to such a configuration, when the resin reaches the inner cylindrical portion 31 from the gate (that is, the gate mark G) during the resin molding, the flow of the resin is sufficiently settled down. As a result, deformation caused by the strength of the resin flow and the disturbance of the resin flow can be suppressed, and the roundness of the inner peripheral surface 60 of the inner cylindrical portion 31 can be improved.

  On the inner peripheral surface 60 of the inner cylindrical portion 31, a plurality of (12 in this case) alignment projecting portions 80 projecting radially inward are formed. As will be described in detail later, each of the alignment protrusions 80 is formed between adjacent ribs 40 of the plurality of ribs 40 in a circumferential positional relationship.

  The inner tubular portion 31 and the outer tubular portion 32 are separated by an annular groove 49. That is, an annular groove 49 recessed from the image side L2 is formed between the outer peripheral surface 31a of the inner cylindrical portion 31 and the inner peripheral surface 32a of the outer cylindrical portion 32. For example, as shown in FIG. 2, when the lens group 2 is disposed, the deepest portion of the concave (that is, the distal end portion of the object side L1) has the third lens 23 and the fourth lens 24 in the optical axis L direction. It is greater than the boundary, that is, the position where the diaphragm 28 is arranged.

  In the annular groove 49, from the outer peripheral surface 31a of the inner cylindrical portion 31 toward the inner peripheral surface 32a of the outer cylindrical portion 32, the plurality of ribs 40 described above, more specifically, in the circumferential direction (on the XY plane). Twelve ribs 40 are formed at intervals of 30 degrees. The ribs 40 include two types, namely, a locking rib 41 having a positioning portion 42 having a locking shape at the end of the image side L2, and a basic rib 43 having no positioning portion 42. For example, as shown in FIGS. 3 and 4, two ribs 40 extending in a direction parallel to the X axis are basic ribs 43, and ten other ribs 40 are locking ribs 41.

  The mating member is locked and fixed to the locking rib 41 directly or via a spacer member. The partner member is, for example, an electronic member 99 including an image sensor mounted on the board, a holding member for holding the board, and the like. The outer shape of the electronic member 99 is substantially square in plan view. By providing the ribs 40 at eight or more positions, it is possible to accurately position the vicinity of the center or the corner of the outer shape of the electronic member 99. As a result, the positional accuracy of the electronic member 99 can be improved. Further, since the electronic member 99 can be fixed to the image-side L2 end (actually, the locking rib 41 of the rib 40) of the inner cylindrical portion 31 apart from the outer cylindrical portion 32, an external impact or the like can be prevented. Direct action on the member 99 can be prevented, and failure can be suppressed.

  In addition, since the annular groove 49 functions as a hollow between the inner cylindrical portion 31 and the outer cylindrical portion 32, sink can be suppressed when the lens barrel 3 is formed. That is, the molding accuracy of the lens barrel 3 can be improved, and the resolution of the lens unit 1 can be further increased. In addition, since the rib 40 is provided with the positioning portion 42 for the electronic member 99, there is no need to provide a member or structure for fixing the electronic member 99, and the number of components is reduced, thereby simplifying the assembly work and reducing the cost. be able to.

  Further, since the inner cylindrical portion 31 is reinforced by the plurality of ribs 40, the strength of the inner cylindrical portion 31 that accommodates the lens group 2 can be secured. In addition, the resonance phenomenon of the inner cylindrical portion 31 due to external vibration can be suppressed. By adjusting the shape and the like of the rib 40, it is possible to cope with various resonances (resonance frequencies).

  The positioning part 42 includes a mounting surface 44 on which the electronic member 99 is mounted, and a protruding part 45 that regulates a position in the radial direction. The two locking ribs 41 parallel to the Y-axis direction (the locking ribs 41 extending in the vertical direction in FIG. 5) are such that only the protruding portion 45 partially hangs on the end surface of the inner cylindrical portion 31 on the image side L2. Is formed. The mounting surface 44 and the end surface of the image side L2 of the inner cylindrical portion 31 are formed on the same plane, and the electronic member 99 is mounted on the mounting surface 44 and the end surface of the image side L2 of the inner cylindrical portion 31. Fixed. The fixed electronic member 99 is positioned on the XY plane by the protrusion 45. Note that the electronic member 99 may be configured to be mounted only on the mounting surface 44.

(Inner surface structure)
With reference to FIGS. 9 to 12, the centering protrusion 80 formed on the inner peripheral surface 60 will be specifically described. FIG. 9 is an enlarged view of the area A1 in FIG. FIG. 10 is a diagram showing the inner cylindrical portion 31 in the XY cross section. FIG. 11 is an enlarged view showing a region A2 of FIG. 10, that is, one alignment protrusion 80. As shown in FIG. FIG. 12 is a diagram illustrating a process of forming the shape of the lens barrel mold 90 corresponding to the alignment protrusion 80.

  The inner peripheral surface 60 includes a cylindrical second lens housing portion 72 for housing the second lens 22 and a third lens 23 from the object side L1 to the image side L2 (for example, from top to bottom in FIG. 9). , A cylindrical fourth lens housing 74 that houses the fourth lens 24 (actually the lens holder 4), and a cylindrical fifth housing 25 that houses the fifth lens 25. It has a lens housing 75.

  In the second to fifth lens housing portions 72 to 75, the outer shape of the second lens housing portion 72 on the object side L1 is the largest corresponding to the outer shape of the above-described lens, and the outer shape gradually decreases toward the image side L2. Has become. Each of the second to fifth lens housing portions 72 to 75 has a centering projection 80 at equal intervals in the circumferential direction.

  As described above, the centering protrusions 80 are provided at a plurality of positions at equal intervals in the circumferential direction, here at 12 positions at 30 ° intervals, and the centering protrusions 80 project inward in the radial direction (the bulging shape). ). The ribs 40 are also formed at intervals of 30 degrees. The centering projection 80 is formed not at the position where the ribs 40 are formed but at a position shifted by 15 degrees, that is, between adjacent ribs 40 in the circumferential positional relationship.

  The centering projection 80 includes a first centering projection 81 projecting (bulging) radially inward from the inner peripheral surface 60, and a second centering projection 81 projecting radially inward from the first centering projection 81. And a centering projection 82. Here, the second alignment protrusion 82 is formed so as to be sandwiched between the two first alignment protrusions 81 from the left and right. As described above, the centering protrusion 80 has a two-step protrusion structure in which the protrusion amount from the inner peripheral surface 60 is different.

  As described above, twelve alignment protrusions 80 are provided at intervals of 30 degrees. Therefore, for example, when a gate cut portion is provided like the second lens 22, the third lens 23, the fourth lens 24 (the lens holder 4), and the fifth lens 25, the number of the alignment protrusions 80 is 12 or more. By doing so, even when the alignment protrusion 80 does not hit the gate cut portion, a sufficient alignment function can be exerted by the remaining alignment protrusion 80.

  Here, when the plurality of ribs 40 extend radially outward from the outer peripheral surface 31a of the inner cylindrical portion 31, the resin forming the inner cylindrical portion 31 may be pulled toward the rib 40 during molding. In such a case, the roundness accuracy of the inner peripheral surface 60 of the inner cylindrical portion 31 near the rib 40 may not be easily obtained. Therefore, even if the resin forming the inner cylindrical portion 31 is pulled toward the ribs 40 during molding, the centering protrusions 80 are formed between the adjacent ribs 40 that have little influence. As a result, the lens group 2 can be housed in the lens barrel 103 with high accuracy by the alignment projection 80, so that the resolution of the lens unit 1 can be increased.

  In addition, even if the alignment projection 80 is formed in any of the second to fifth lens housings 72 to 75, the basic structure is the same, but the structure and shape of the housed lens and the mirror It is easily conceived by those skilled in the art that the difference depends on the manufacturing process of the mold parts of the cylinder 3 and the like.

  The two first centering projections 81 project inward from the arc-shaped inner peripheral surface 60, but are formed on the same plane C1. Further, a second alignment protrusion 82 having a curved surface C2 is formed on the first alignment protrusion 81 formed on the plane C1. That is, the second centering projection 82 projects as a long-axis rib extending in parallel to the optical axis direction. The lenses (the second lens 22, the third lens 23, the lens holder 4, and the fifth lens 25) are press-fitted into the second alignment protrusions 82 and are firmly held.

  Here, the first centering projection 81 is formed on the plane C1, but more specifically, the twelve first centering projections 81 formed in the circumferential direction make the first centering projection 81 the most. Twelve positions C3 protruding inward are located on a concentric circle Rx centered on the optical axis L, that is, on the outer periphery of the lens. In addition, the projection amounts of the first alignment projections 81 as the plurality of flat portions may be different from each other in order to match the intended concentric circle Rx. Further, the concentric circle Rx does not necessarily need to be on the outer periphery of the lens. For example, a virtual circle having a gap of about several microns from the outer periphery of the lens may be used as the concentric circle Rx.

  In this way, by forming the first alignment protrusions 81 as a plurality of plane portions so as to have the target concentric circle Rx, perfect circle correction is facilitated. That is, since the first centering projection 81 is a flat portion (the flat surface C1), it is easy to take a reference when manufacturing and correcting a mold for manufacturing, and it is easy to obtain accuracy.

Although the first alignment protrusion 81 is formed in the plane C1, the present invention is not limited to this. For example, the first alignment protrusion 81 may be a rib having a curved cross section, like the second alignment protrusion 82. In this case, the shapes of the first alignment protrusion 81 and the second alignment protrusion 82 satisfy the conditional expression (1), and the first alignment protrusion 81 is larger than the second alignment protrusion 82. It is desirable to have a sufficiently gentle curved surface.
2 × R2 ≦ R1 conditional expression (1)
R1: radius of curvature of the first alignment projection 81 R2: radius of curvature of the second alignment projection 82 The first alignment projection 81 that satisfies the conditional expression (1), and the second alignment By setting the shape of the protrusion 82, even if both are ribs, it is relatively easy to obtain a desired accuracy at the position C where the first alignment protrusion 81 is the concentric circle Rx.

(About the mold)
Next, referring to FIG. 12, a mold used when the lens barrel 3 is manufactured by injection molding, in particular, a lens barrel mold 90 corresponding to the inner peripheral surface 60 and the alignment protrusion 80 formed thereon. Will be described. The lens barrel mold 90 is a cylindrical (or cylindrical) mold part having a circular cross section. It is arranged inside another mold part having a cylindrical hollow, and the resin is placed in the space between its inner peripheral surface and the outer peripheral surface of the lens barrel mold 90 (the inner peripheral surface forming surface 91 of the inner peripheral surface 60). Is introduced by injection to manufacture the inner peripheral surface 60.

  Here, as a mold shape for forming the centering protrusion 80 of the inner peripheral surface 60, as shown in FIG. 12C, the lens barrel mold 90 is formed of the first centering protrusion 81. It has a flat portion 92 corresponding to the plane C1 and a concave curved surface 93 corresponding to the second alignment projection 82.

  First, the lens barrel 3 is manufactured by injection molding in a state where the shape (the concave curved surface 93 and the flat portion 92a) corresponding to the alignment protrusion 80 is not formed in the lens barrel die 90. Thereby, the lens barrel 3 (the inner peripheral surface 60) without the alignment protrusion 80 (the first alignment protrusion 81 and the second alignment protrusion 82) is formed. In this state, the roundness of the inner peripheral surface 60 is measured and analyzed. That is, as shown in FIG. 12A, a region D1 to be cut on the plane E1 on the inner peripheral surface forming surface 91 is determined. The area D1 to be shaved, that is, the amount of projection of the first centering projection 81 corresponding thereto may be different from each other.

  Subsequently, the above-described region D1 is scraped off, and a flat portion 92 is formed on the inner peripheral surface forming surface 91 as shown in FIG. The scraped center portion E2 is located on a virtual concentric circle (corresponding to the outer periphery of the lens, ie, a concentric circle Rx in FIG. 11B) of the target lens. A predetermined number of them are formed at equal intervals in the circumferential direction, and 12 are formed at 30-degree intervals in the above example.

  Subsequently, as shown in FIG. 12C, a concave curved surface 93 having a long axis-shaped arc E3 is formed in the center of the flat portion 92 in the vertical direction. Thereby, the flat portion 92 is divided into two flat portions 92a so as to sandwich the concave curved surface 93. The concave curved surface 93 corresponds to the second alignment protrusion 82. It is desirable that the depth of the concave curved surface 93, that is, the amount of protrusion of the second alignment projection 82 used for light press-fitting is the same in all the second alignment projections 82.

  Since the flat portion 92 formed of a flat surface is formed in the lens barrel mold 90 in such a process, it is easy to take a reference and processing is easy, and it is easy to obtain a desired virtual concentric circle. That is, in the case of the perfect circular correction that realizes the position of the virtual concentric circle of the lens and the structure of the light press-fitting only by the ribs alone, it is difficult and time-consuming to adjust the precision. The adjustment is easy and the adjustment time can be greatly reduced.

<Second embodiment>
FIG. 13 is a rear view of the lens barrel 103 according to the second embodiment, and corresponds to FIG. 5 described above. Hereinafter, points different from the first embodiment will be described, and description of common configurations and the like will be omitted. The difference from the first embodiment is that the rib 140 is formed from the outer cylindrical portion 132 to the inner cylindrical portion 131. Specifically, an annular groove 149 is formed between the outer peripheral surface 131a of the inner cylindrical portion 131 and the inner peripheral surface 132a of the outer cylindrical portion 132. A rib 140 is formed from the inner peripheral surface 132a of the outer cylindrical portion 132 toward the inner cylindrical portion 131. The rib 140 is not in contact with the outer peripheral surface 131a of the inner cylindrical portion 131 but is separated therefrom.

  The rib 140 is a locking rib 141, which is used to lock and fix the electronic member 99 as a mating member. A gate mark G is formed at an end 133 of the outer cylindrical portion 32 on the image side L2. The positioning portion 142 of the locking rib 41 is provided with at least one of the same structure as the mounting surface 44 and the protruding portion 45 described in the embodiment according to the structure and size of the electronic member 99 to be mounted.

<Third embodiment>
FIG. 14 shows a rear view of the lens barrel 203 according to the third embodiment, which corresponds to FIG. 5 described above, and includes an inner cylindrical portion 231, an outer cylindrical portion 232, and a cylindrical base portion 233. . Hereinafter, points different from the first and second embodiments will be described, and description of common configurations and the like will be omitted. The configuration of the present embodiment has a structure in which the lens barrel 3 of the first embodiment and the lens barrel 3 of the second embodiment are combined. That is, there are ribs 240 that go from the inner tube portion 231 to the outer tube portion 232 and ribs that go from the outer tube portion 232 to the inner tube portion 231.

  Specifically, as in the first embodiment, the electronic member 99 is attached to the end of the image side L2 as the rib 240 extending from the outer peripheral surface 231a of the inner cylindrical part 231 to the inner peripheral surface 232a of the outer cylindrical part 232. There are two types, a locking rib 241 having a locking shape (a shape corresponding to the positioning portion 42 of the first embodiment) and a basic rib 243a having no positioning portion. For example, two ribs 240 extending in a direction parallel to the X-axis are basic ribs 243a, and ten other ribs 240 are locking ribs 241. Further, a basic rib 243b is formed from the inner peripheral surface 232a of the outer cylindrical portion 232 toward the inner cylindrical portion 231. The position of the locking rib 241 differs depending on the size and shape of the electronic member 99. That is, the rib 240 may be formed on the rib 240 extending from the outer cylindrical portion 232, or may be formed on both ribs, and the amount of extension may be different from each other.

  In the lens unit having such a lens barrel 203, both effects of the first embodiment and the effects of the second embodiment can be realized.

  As described above, the present invention has been described based on the embodiment. However, this embodiment is an exemplification, and various modifications can be made to the combination of each component, and such a modification is also described in the present embodiment. It is understood by those skilled in the art that they are within the scope of the invention.

The features of the above embodiment can be summarized as follows.
The lens unit 1 includes a plurality of lenses (lens group 2), an inner cylindrical portion 31 in which the plurality of lenses (lens group 2) are housed, an outer cylindrical portion 32 radially outwardly spaced from the inner cylindrical portion 31, A lens barrel 3 having a plurality of radially extending ribs 40 between the inner cylindrical portion 31 and the outer cylindrical portion 32, and at least one of the plurality of ribs 40 is provided on the image-side end face by a mating member. The locking rib 41 includes a positioning portion 42 for positioning with the electronic member 99. All of the ribs 40 may be locking ribs 41 or some of them may be basic ribs 43 having no positioning portion 42. By forming the plurality of ribs 40 between the inner tubular portion 31 and the outer tubular portion 32, a function as a lightening between the inner tubular portion 31 and the outer tubular portion 32 is provided. As a result, the occurrence of sink marks during resin molding can be suppressed, and the molding accuracy of the lens barrel 3 can be improved. That is, the resolution of the lens unit 1 can be further increased. Further, since the ribs 40 are provided with the positioning portions 42 for the other members, the number of parts can be reduced to simplify the assembly work and reduce the cost.

  The plurality of ribs 40 are separated between an outer peripheral surface 31a of the inner cylindrical portion 31 and an inner peripheral surface 32a of the outer cylindrical portion 32. That is, the rib 40 does not connect the inner tubular portion 31 and the outer tubular portion 32.

  In the example of the first embodiment, the plurality of ribs 40 extend radially outward from the outer peripheral surface 31 a of the inner cylindrical portion 31, and are provided between the plurality of ribs 40 and the outer cylindrical portion 32. , An annular groove 49 is formed. Since the inner tubular portion 31 is reinforced by the plurality of ribs 40, the strength of the inner tubular portion 31 is ensured. In addition, the plurality of ribs 40 can suppress resonance of the inner cylindrical portion 31 due to external vibration.

  In the example of the second embodiment, the plurality of ribs 140 extend radially inward from the inner peripheral surface 132a of the outer cylindrical portion 132, and are disposed between the plurality of ribs 140 and the inner cylindrical portion 131. Is formed with an annular groove 149. Since the annular groove 149 is formed between the plurality of ribs 140 and the inner cylindrical portion 131 and the rib 140 and the inner cylindrical portion 131 are not connected, the deformation of the inner cylindrical portion 131 due to the rib 140 does not occur. Therefore, the lens group 2 can be held on the inner cylindrical portion 131 with higher accuracy, and the resolution of the lens unit 1 can be further increased. Further, since the plurality of ribs 140 extend radially inward from the inner peripheral surface 132a of the outer tubular portion 132, the strength of the outer tubular portion 32 can be improved.

  The positioning portion 42 includes a mounting surface 44 on which the partner member (electronic member 99) is mounted, and a protrusion 45 for regulating a position in the radial direction.

  The inner peripheral surface 60 of the inner cylindrical portion 31 includes a plurality of centering protrusions 80 protruding radially inward, and each of the plurality of centering protrusions 80 is adjacent to the plurality of ribs 40. It is formed between the ribs 40. If the ribs 40 extend radially outward from the outer peripheral surface 31a of the inner cylindrical portion 31, the resin forming the inner cylindrical portion 31 is pulled toward the ribs during resin molding, and the inner cylindrical portion 31 near the ribs 40 is removed. In some cases, it is difficult to obtain the accuracy of the inner peripheral surface 31a. Therefore, even if the resin forming the inner cylindrical portion 31 is pulled toward the ribs at the time of molding, the projecting portion 80 for alignment is formed between the adjacent ribs 40 with little influence, so that the resin at the time of resin molding is formed. Since a decrease in accuracy due to rib pulling or the like can be suppressed, the resolution of the lens unit 1 can be increased.

  The shape of the mating member (electronic member 99) is substantially rectangular, and a plurality of ribs 40 are formed at eight or more places. In the case where the mating member (electronic member 99) is substantially square, the ribs at eight or more places can be positioned near the center or near the corner of the side of the mating member, so that the positioning accuracy can be improved. .

Reference Signs List 1 lens unit 2 lens groups 3, 103, 203 lens barrel 4 lens holder 5 O-ring 21 first lens 22 second lens 23 third lens 24 fourth lens 25 fifth lens 26 sixth lens 27 light shielding sheet 28 diaphragm 31, 131, 231 Inner cylindrical portion 31a, 131a, 231a Outer peripheral surface 32, 132, 232 Outer cylindrical portion 32a, 132a, 232a Inner peripheral surface 33, 133, 233 End portion 34 Receiving portion 35, 36 Caulking portion 38 Infrared cut filter 39 Spacer 40, 140, 240 Ribs 41, 141, 241 Locking ribs 42, 142 Positioning portions 43, 243a, 243b Basic ribs 44 Mounting surface 45 Projecting portion 49, 149 Annular groove 60 Inner peripheral surface 61 Flat portion 64 Recess 69 6 lens housing 69a opening 72 second lens housing 73 third lens housing 74 fourth Lens accommodating portion 75 fifth lens accommodating portion 80 alignment projection 81 first alignment projection 82 second alignment projection 90 lens barrel 91 inner peripheral surface forming surface 92, 92a flat portion 93 concave curved surface 99 Electronic member G Gate mark L Optical axis L1 Object side L2 Image side

Claims (7)

With multiple lenses,
An inner cylindrical portion in which the plurality of lenses are housed, an outer cylindrical portion radially outwardly separated from the inner cylindrical portion, a plurality of ribs radially extending between the inner cylindrical portion and the outer cylindrical portion, A lens barrel comprising: a lens barrel having at least one of the plurality of ribs is a locking rib having a positioning portion on the image side end surface for positioning with a counterpart member.   The lens unit according to claim 1, wherein the plurality of ribs are separated between an outer peripheral surface of the inner cylindrical portion and an inner peripheral surface of the outer cylindrical portion. The plurality of ribs extend radially outward from the outer peripheral surface of the inner cylindrical portion,
The lens unit according to claim 2, wherein an annular groove is formed between the plurality of ribs and the outer cylindrical portion. The plurality of ribs extend radially inward from the inner peripheral surface of the outer cylindrical portion toward the inside in the radial direction,
The lens unit according to claim 2, wherein an annular groove is formed between the plurality of ribs and the inner cylindrical portion.   The lens unit according to any one of claims 1 to 4, wherein the positioning unit includes a mounting surface on which the counterpart member is mounted, and a protruding portion that regulates a position in a radial direction. . The inner peripheral surface of the inner cylindrical portion includes a plurality of centering protrusions that protrude radially inward,
4. The lens unit according to claim 3, wherein each of the plurality of alignment protrusions is formed between adjacent ribs of the plurality of ribs. 5. The shape of the mating member is substantially square,
The lens unit according to claim 1, wherein the plurality of ribs are formed at eight or more positions.

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