Lens unit

Abstract

The invention provides a lens unit. The lens unit includes: a plurality of lenses including a first lens and a second lens; a lens barrel that accommodates the plurality of lenses; and a pressing member provided between the first lens and the second lens. The pressing member includes: a side wall portion having a cylindrical shape centered on an optical axis of the plurality of lenses; a contact surface located at an end portion of one end side of the side wall portion in a direction along the optical axis, the contact surface being in contact with the first lens; a holding part which is provided on the other end side of the side wall part in the direction of the optical axis, and which holds the second lens by being in contact with the second lens; a coupling portion provided along the outer periphery of the other end side of the side wall portion and screwed to a first region of the inner peripheral wall surface of the lens barrel; and a connecting part forming surface, which is different from the contact surface, and is provided with a connecting part that is connected to a tool that rotates the pressing member about the optical axis.

Description

Technical Field

[0001] This invention relates to lens units. Background Technology

[0002] Previously, lens units were known where the position of the optical axis of the lens was adjusted within a fixed cylinder using an adjustment tool during manufacturing. Patent Document 1 discloses a lens unit comprising a fixed cylinder, a lens held within the fixed cylinder via a holding member, and a pressing member that presses the lens against the holding member in the optical axis direction. An adjustment tool is inserted into a hole formed in the pressing member and engages with a locking portion of the holding member. By rotating the adjustment tool about the optical axis, the holding member rotates relative to the fixed cylinder, thereby adjusting the position of the optical axis of the lens held against the holding member.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2023-90252

[0004] However, if burrs fall off during adjustment, depending on where the burrs are attached, it may adversely affect the positional accuracy of the lens's optical axis. Summary of the Invention

[0005] One embodiment of the lens unit includes: a plurality of lenses, including a first lens and a second lens; a lens barrel housing the plurality of lenses; and a pressing member disposed between the first lens and the second lens. The pressing member has: a sidewall portion that is cylindrical about the optical axis of the plurality of lenses; a contact surface located at one end of the sidewall portion along the optical axis, contacting the first lens; a holding portion disposed at the other end of the sidewall portion along the optical axis, holding the second lens by contacting it; a connecting portion disposed along the outer periphery of the other end of the sidewall portion, threadedly engaging with a first region of the inner peripheral wall of the lens barrel; and a connecting portion forming surface, different from the contact surface, having a connecting portion for connecting to a tool that rotates the pressing member about the optical axis.

[0006] According to the present invention, lenses can be configured with high precision within the lens barrel. Attached Figure Description

[0007] Figure 1 This is a perspective view of the lens unit in the embodiment.

[0008] Figure 2 It is along Figure 1 A cross-sectional view of the lens unit along the AA line.

[0009] Figure 3A This is a 3D view of the pressing component.

[0010] Figure 3B This is a side view of the pressing component.

[0011] Figure 4A This is a cross-sectional view of the pressing component in the first modified example.

[0012] Figure 4B This is a cross-sectional view of the pressing component of another example of the first variation.

[0013] Figure 5 This is an external view of the lens unit in the second modified example.

[0014] Label Explanation

[0015] 10: Lens unit; 20: Lens barrel; 30: Optical component; 40: Pressing component; 41: Side wall portion; 42: Holding portion; 43: Connecting portion; 60, 70: Through hole; 61, 71: First hole portion; 62, 72: Recessed portion; 63, 73: Second hole portion; 201: Outer peripheral wall surface; 202: Inner peripheral wall surface; 203: First region; 204: Second region; 301, 302, 303, 304, 305, 306, 307, 308: Lens; 302: First lens; 303: Second lens; 410: Contact surface; 411: Outer peripheral surface; 412: Joint portion; 413: Fixing portion; 415, 421: Front side surface; 422: Rear side surface; 423: Inclined surface; Ax: Optical axis. Detailed Implementation

[0016] <Implementation Method>

[0017] Hereinafter, the lens unit of the embodiment will be described in detail with reference to the accompanying drawings.

[0018] Figure 1 This is a perspective view of the lens unit 10 according to the embodiment. Figure 2 It is along Figure 1 The image shows a cross-sectional view of the lens unit 10 along line AA. The lens unit 10 includes a lens barrel 20, an optical component 30, and a pressing component 40. The lens unit 10 is used, for example, by mounting it in a measuring instrument, a camera device, or the like.

[0019] Additionally, for ease of explanation, an x-axis parallel to the optical axis Ax of the optical component 30 and a x-axis perpendicular to the x-axis and along... Figure 2 The x-axis is an orthogonal coordinate system formed by the z-axis (vertical direction) and the y-axis (perpendicular to the x-axis and z-axis). Additionally, in the following explanation, the x-axis + side is sometimes referred to as the front, and the x-axis - side as the back.

[0020] <Optical Components 30>

[0021] The optical component 30 is housed inside the lens barrel 20, which will be described later. The optical component 30 consists of a plurality of lenses 301, 302, 303, 304, 305, 306, 307, and 308 arranged along the x-axis inside the lens barrel 20. The eight lenses 301, 302, 303, 304, 305, 306, 307, and 308 are arranged from the x-axis+ side in the order described above. As mentioned above, each lens 301, 302, 303, 304, 305, 306, 307, and 308 is arranged with the optical axis Ax parallel or substantially parallel to the x-axis. Furthermore, the number of lenses in the optical component 30 is not limited to eight; it can be two or more, and may be seven or fewer, or nine or more.

[0022] Lenses 301 and 302 are included in the first lens group 31. The diameters of lenses 301 and 302 are equal or approximately equal to each other. Lenses 303, 304, and 305 are included in the second lens group 32. The diameters of lenses 303, 304, and 305 are equal or approximately equal to each other. Lenses 306, 307, and 308 are included in the third lens group 33. The diameters of lenses 306, 307, and 308 are equal or approximately equal to each other.

[0023] The diameters of lenses 301 and 302 included in the first lens group 31 are larger than the diameters of lenses 303, 304, and 305 included in the second lens group 32. The diameters of lenses 306, 307, and 308 included in the third lens group 33 are larger than the diameters of lenses 303, 304, and 305 but smaller than the diameters of lenses 301 and 302.

[0024] Furthermore, the number of lenses contained in each of the first lens group 31, the second lens group 32, and the third lens group 33 is not limited to the examples described above.

[0025] <Binoculars 20>

[0026] The lens barrel 20 houses the optical component 30. The lens barrel 20 is a hollow cylinder with the optical axis Ax of the housed optical component 30 as its central axis. The lens barrel 20 is made of, for example, resin or metal. The lens barrel 20 has a first housing section 21, a second housing section 22, and a third housing section 23 formed therein to house the optical component 30 (described later). Furthermore, through holes 60 and 70 are formed on the sidewalls of the lens barrel 20.

[0027] A first storage portion 21 is formed near the end of the lens barrel 20 on the x-axis + side. A third storage portion 23 is formed near the end of the lens barrel 20 on the x-axis - side. A second storage portion 22 is formed between the first storage portion 21 and the third storage portion 23. The x-axis + side of the second storage portion 22 is connected to the x-axis - side of the first storage portion 21. The x-axis - side of the second storage portion 22 and the x-axis + side of the third storage portion 23 are connected via a connecting space 24. The diameters of the first storage portion 21, the second storage portion 22, and the third storage portion 23 are different.

[0028] <Section 1 Storage 21>

[0029] The first storage section 21 houses the lenses 301 and 302 included in the first lens group 31, and the pressing member 40 (described later). Specifically, in the first storage section 21, the lenses 301 and 302, and the pressing member 40 (described later) are arranged sequentially from the x-axis + side. The diameter of the first storage section 21, that is, the inner diameter of the lens barrel 20 at the location where the first storage section 21 is formed, is equal to or approximately equal to the diameter of the lenses 301 and 302.

[0030] Lens 301 is pressed from the front (x-axis + side) to the rear by the front pressing ring 34. The rear end (x-axis - side) of lens 301 is in partial contact with the front end (x-axis + side) of lens 302. A portion of the rear end of lens 302 is in contact with the front side of the pressing member 40.

[0031] A portion of the rear side of the pressing member 40 contacts a portion of the front end of the lens 303 included in the second lens group 32. That is, the pressing member 40 is disposed at the rear end of the first storage portion 21. In the following description, the lens 302 is referred to as the first lens 302, and the lens 303 is referred to as the second lens 303.

[0032] A through hole 60 is formed near the rear end of the first storage portion 21, penetrating the wall of the lens barrel 20. That is, the through hole 60 is formed in the x-axis direction at a position overlapping with the location where the pressing member 40 is disposed. The through hole 60 will be described in detail later. Furthermore, "near the rear end of the first storage portion 21" refers to a position that separates from the rear end of the first storage portion 21 towards the x-axis + side, depending on the shape of the pressing member 40 described later.

[0033] An internal thread is formed in a first region 203 at the rear end of the inner peripheral wall surface 202 of the first storage portion 21. The pressing member 40, described later, is installed in the first storage portion 21 by threading into the internal thread formed in the first region 203. Furthermore, a second region 204 is formed at the rear end of the inner peripheral wall surface 202 at a position closer to the x-axis than the first region 203 (see reference). Figure 3BThe pressing member 40, described later, is fixed within the first storage section 21 by engaging with the second region 204.

[0034] <Second Storage Section 22>

[0035] In the second storage section 22, lenses 303, 304, and 305, included in the second lens group 32, are arranged sequentially from the x-axis + side. The diameter of the second storage section 22, i.e., the inner diameter of the lens barrel 20 at the location where the second storage section 22 is formed, is equal to or approximately equal to the diameter of lenses 303, 304, and 305. The diameters of lenses 303, 304, and 305 are smaller than the diameters of lenses 301 and 302; therefore, the diameter of the second storage section 22 is smaller than the diameter of the first storage section 21.

[0036] The front side of lens 303 protrudes from the second receiving portion 22. Furthermore, a portion of the front end of lens 303 contacts the rear side of the pressing member 40 housed within the first receiving portion 21. The rear end of lens 303 partially contacts the front end of lens 304. The rear end of lens 304 partially contacts the front end of lens 305. The rear end of lens 305 partially contacts the rear wall surface 220 of the second receiving portion 22.

[0037] <Part 3 Storage 23>

[0038] The third receiving section 23 houses lenses 306, 307, and 308, and hollow cylindrical spacers 50 and 51, which are included in the third lens group 33. Specifically, lenses 306, 307, and 308 are arranged sequentially from the x-axis + side. Spacer 50 is disposed between lenses 306 and 307. Spacer 51 is disposed between lenses 307 and 308. The diameter of the third receiving section 23, i.e., the inner diameter of the lens barrel 20 at the location where the third receiving section 23 is formed, is equal to or approximately equal to the diameters of lenses 306, 307, and 308 and the outer diameters of spacers 50 and 51.

[0039] As described above, the diameters of lenses 306, 307, and 308 are larger than the diameters of lenses 303, 304, and 305 in the second lens group 32, but smaller than the diameters of lenses 301 and 302 in the first lens group 31. Therefore, the diameter of the third storage portion 23 is larger than the diameter of the second storage portion 22, but smaller than the diameter of the first storage portion 21.

[0040] The front side of lens 306 partially contacts the front wall surface 230 of the third receiving portion 23. The rear side of lens 306 partially contacts the front side of spacer member 50. The front side of lens 307 partially contacts the rear side of spacer member 50, and the rear side of lens 307 partially contacts the front side of spacer member 51. The front side of lens 308 partially contacts the rear side of spacer member 51. Lens 308 is pressed from the rear to the front by rear pressing ring 35.

[0041] A through hole 70 is formed in the lens barrel 20 within the area where the third receiving portion 23 is formed, penetrating the wall of the lens barrel 20. Specifically, the through hole 70 is formed in the x-axis direction at a position overlapping with the position of the placement spacer member 50. Furthermore, the through hole 70 will be described in detail later.

[0042] Alternatively, the through hole 70 may be formed in the x-axis direction at a position overlapping with the position of the spacer 51. Alternatively, the through hole 70 may be provided in the x-axis direction at a position overlapping with at least one of the positions of the lenses 306, 307, and 308, instead of the positions of the spacers 50 and 51.

[0043] <Through Hole 60>

[0044] As described above, the through hole 60 is formed in the x-axis direction at a position overlapping with the location where the pressing member 40 is disposed. Specifically, the through hole 60 is formed in the x-axis direction at a position overlapping with the fixing portion 413 (described later) that forms the pressing member 40. Figure 3A , Figure 3B The position of the through hole 60 overlaps with the second region 204 of the inner peripheral wall surface 202 of the first receiving part 21 in the x-axis direction. More specifically, the position of the through hole 60 overlaps with the second region 204 of the inner peripheral wall surface 202 of the first receiving part 21 in the x-axis direction.

[0045] The through hole 60 is used to assemble the lenses 301 and 302 with high precision into the first storage section 21 during the manufacturing process of the lens unit 10. Specifically, the pressing member 40 is aligned by means of a fixture or the like inserted into the through hole 60. Then, an adhesive or the like is applied into the through hole 60 to fix the pressing member 40 into the first storage section 21.

[0046] Multiple through holes 60 are formed along the circumference of the lens barrel 20. For example, three through holes 60 are provided at 120° intervals along the circumference of the lens barrel 20. In addition, the number of through holes 60 is not limited to three, and may be four or more.

[0047] The through-hole 60 penetrates the outer peripheral wall 201 of the lens barrel 20 and the inner peripheral wall 202 of the first receiving portion 21. More specifically, the through-hole 60 penetrates the outer peripheral wall 201 and the second region 204 of the first receiving portion 21. That is, the through-hole 60 is formed along the radial direction of the lens barrel 20. In addition, the radial direction of the lens barrel 20 refers to the direction that is perpendicular or substantially perpendicular to the optical axis Ax (x-axis).

[0048] The through hole 60 is composed of a first hole portion 61, a recess portion 62, and a second hole portion 63. The first hole portion 61 is formed on the outer peripheral wall surface 201 side of the lens barrel 20. The recess portion 62 is formed on the second region 204 side. Alternatively, the recess portion 62 can be a hole formed on the inner peripheral wall surface 202 or a groove along the circumferential direction. The second hole portion 63 connects the first hole portion 61 and the recess portion 62.

[0049] The first hole 61 is formed as a cone with a diameter that decreases as it approaches the second region 204 from the outer peripheral wall 201. The length of the recess 62 in the x-axis direction, i.e., along the optical axis Ax, is different from the diameter of the second hole 63. Specifically, the length of the recess 62 in the x-axis direction is greater than the diameter of the second hole 63. The radial length of the recess 62 is greater than the length of the burr protruding from the end of the second hole 63 toward the optical axis Ax. Therefore, the burr generated at the end of the second hole 63 is contained within the recess 62. Furthermore, the burr is generated during the opening process of the through hole 60 in the manufacturing process of the lens barrel 20.

[0050] Furthermore, the length of the recess 62 in the x-axis direction is greater than that of the fixing portion 413 of the pressing member 40 described later (see reference). Figure 3A , Figure 3B The length of the through-hole 60 in the x-axis direction is short. Therefore, the end of the through-hole 60 on the Ax side of the optical axis is blocked by the fixing part 413. Thus, it is possible to suppress external light from entering the interior of the lens barrel 20 through the through-hole 60. As a result, it is unnecessary to configure a component for blocking the light from the through-hole 60, or to allow light-blocking adhesive to flow into the through-hole 60.

[0051] <Through Hole 70>

[0052] As described above, the through hole 70 is formed in the x-axis direction at a position overlapping with the position where the spacer member 50 is disposed. The through hole 70 is used to assemble the lenses 306, 307, and 308 into the third receiving portion 23 with high precision during the manufacturing process of the lens unit 10. Specifically, the spacer member 50 is aligned by means of a fixture or the like inserted into the through hole 70. Then, an adhesive or the like is applied into the through hole 70 to fix the spacer member 50 into the third receiving portion 23.

[0053] Multiple through holes 70 are formed along the circumference of the lens barrel 20. For example, three through holes 70 are provided at 120° intervals along the circumference of the lens barrel 20. However, the number of through holes 70 is not limited to three; it can be four or more. The through holes 70 penetrate the outer peripheral wall surface 201 of the lens barrel 20 and the inner peripheral wall surface 205 of the third receiving portion 23. That is, the through holes 70 are formed along the radial direction of the lens barrel 20.

[0054] The through hole 70 is composed of a first hole portion 71, a recess portion 72, and a second hole portion 73. The first hole portion 71 is formed on the outer peripheral wall surface 201 side of the lens barrel 20. The recess portion 72 is formed on the inner peripheral wall surface 205 side. Alternatively, the recess portion 72 can be a hole formed on the inner peripheral wall surface 205 or a groove along the circumferential direction. The second hole portion 73 connects the first hole portion 71 and the recess portion 72.

[0055] The first hole 71 is formed as a cone with a diameter that decreases as it approaches the inner peripheral wall 205 from the outer peripheral wall 201. The length of the recess 72 in the x-axis direction is different from the diameter of the second hole 73. Specifically, the length of the recess 72 in the x-axis direction is greater than the diameter of the second hole 73. The radial length of the recess 72 is greater than the length of the burr protruding from the end of the second hole 73 toward the optical axis Ax. Therefore, the burr generated at the end of the second hole 73 is contained within the recess 72. Furthermore, the burr is generated during the opening process of the through hole 70 in the manufacturing process of the lens barrel 20.

[0056] Furthermore, the length of the recess 72 in the x-axis direction is shorter than the length of the spacer member 50 in the x-axis direction. Therefore, the end of the through-hole 70 on the optical axis Ax side is blocked by the spacer member 50. Thus, it is possible to suppress external light from entering the interior of the lens barrel 20 through the through-hole 70. As a result, it is unnecessary to configure a component for blocking the through-hole 70 or to allow light-blocking adhesive to flow into the through-hole 70.

[0057] <Pressing component 40>

[0058] Figure 3A This is a perspective view of the pressing component 40. Figure 3B yes Figure 2 The section view shown is a magnified partial section view of the vicinity of the pressing member 40. (See diagram below.) Figure 3A , Figure 3B As shown, the pressing component 40 is formed into a hollow cylindrical shape with the optical axis Ax as the central axis.

[0059] The pressing member 40 has a side wall portion 41, a holding portion 42, and a connecting portion 43. The connecting portion 43 is formed in the holding portion 42.

[0060] <Side wall portion 41>

[0061] The sidewall portion 41 is cylindrical with the optical axis Ax as its center. The outer diameter of the sidewall portion 41 is equal to or approximately equal to the inner diameter of the first receiving portion 21. A contact surface 410 is formed at one end of the sidewall portion 41, i.e., the front (x-axis + side), which intersects (perpendicularly or approximately perpendicularly) the optical axis Ax (x-axis). Specifically, the contact surface 410 is located at the x-axis + side end of the sidewall portion 41 and is an annular plane centered on the optical axis Ax. When the first lens 302 and the pressing member 40 are received in the first receiving portion 21, the contact surface 410 contacts a portion of the rear end of the first lens 302.

[0062] On the other end side (x-axis side) of the outer peripheral surface 411 of the sidewall portion 41, a connecting portion 412, which is an external thread, is formed along the outer peripheral surface 411. When the pressing member 40 is housed in the first housing portion 21, the connecting portion 412 is threadedly engaged with the first region 203 of the first housing portion 21. Thus, the pressing member 40 is installed in the first housing portion 21.

[0063] A fixing portion 413 is formed on the outer peripheral surface 411 of the sidewall portion 41 at a position closer to the x-axis (front side) than the connecting portion 412. When the pressing member 40 is housed in the first housing portion 21, the fixing portion 413 engages with the second region 204 of the first housing portion 21. Thus, the pressing member 40 is fixed and housed within the first housing portion 21.

[0064] <Maintenance Section 42>

[0065] The retaining part 42 is formed on the radial inner side of the sidewall part 41. The retaining part 42 is cylindrical with the optical axis Ax as the central axis. The retaining part 42 is formed by a front side surface 421, a rear side surface 422, and an inclined surface 423.

[0066] A front side surface 421 is formed at the front end of the retaining portion 42. The front side surface 421 intersects (perpendicularly or substantially perpendicular) the optical axis Ax. The front side surface 421 is located further rearward than the contact surface 410 formed at the front end of the sidewall portion 41.

[0067] A rear surface 422 is formed at the rear end of the retaining portion 42. The rear surface 422 intersects (perpendicularly or substantially perpendicular to) the optical axis Ax. The rear surface 422 is located in front of the rear end of the sidewall portion 41. The distance between the rear surface 422 and the contact surface 410 in the x-axis direction is set to be equal to or substantially equal to the designed distance in the x-axis direction of the first lens 302 and the second lens 303.

[0068] When the pressing member 40 is housed in the first housing portion 21, the rear side surface 422 contacts the second lens 303 housed in the second housing portion 22. As a result, the retaining portion 42 retains the second lens 303 at the other end (rear side) of the side wall portion 41 along the x-axis. Furthermore, the inner diameter of the rear side surface 422 is smaller than the inner diameter of the front side surface 421.

[0069] The inclined surface 423 connects the front side surface 421 and the rear side surface 422. The inner diameter of the rear side surface 422 is smaller than that of the front side surface 421, so the inner wall surface of the retaining part 42 is formed into a cone shape with the inner diameter decreasing towards the x-axis. The tilt angle of the inclined surface 423 relative to the optical axis Ax is set such that no black shadow, or vignetting, occurs in the corner of the image due to the light passing through the first lens 302 being blocked by the inclined surface 423.

[0070] <Link 43>

[0071] When the pressing member 40 is housed within the first housing portion 21, it is threadedly engaged with the lens barrel 20 using a jig or similar device. The connecting portion 43 is connected to the jig or similar device used at this time. Multiple connecting portions 43 are formed on the surface of the holding portion 42 along a circumferential direction centered on the optical axis Ax. Figure 3A The diagram shows two connecting parts 43 arranged at equal intervals along the circumference. However, the number and position of the connecting parts 43 are determined according to the shape of the fixture. That is, the number and position of the connecting parts 43 are not limited to a specific configuration. Figure 3A The example shown.

[0072] like Figure 3B As shown, the connecting portion 43 is a recess formed at the boundary between the front side surface 421 and the inclined surface 423. That is, the front side surface 421 and the inclined surface 423 are connecting portion forming surfaces that are different from the contact surface 410.

[0073] As described above, the front side surface 421 is located further rearward than the contact surface 410 formed on the front end of the side wall portion 41. Furthermore, the inclined surface 423 is the surface connecting the front side surface 421 and the rear side surface 422. Therefore, when the pressing member 40 is housed in the first housing portion 21, the front side surface 421 and the inclined surface 423, which are the connecting surfaces, are further away from the first lens 302 than the contact surface 410.

[0074] Alternatively, the connecting portion 43 may be a through hole that passes through the boundary between the front side surface 421 and the inclined surface 423 and the rear side surface 422. Alternatively, the connecting portion 43 may be a protrusion that protrudes forward from the boundary between the front side surface 421 and the inclined surface 423.

[0075] <Assembly of Lens Unit 10>

[0076] The assembly of the lens unit 10 will be described in two parts: the assembly of the first lens group 31 and the second lens group 32 into the lens barrel 20 and the assembly of the third lens group 33 into the lens barrel 20.

[0077] <Assembly of the first lens group 31 and the second lens group 32 into the lens barrel 20>

[0078] Within the second storage section 22, lenses 303, 304, and 305 of the second lens group 32 are arranged along the optical axis Ax. When the second lens group 32 is disposed within the lens barrel 20, a pressing member 40 is installed in the first storage section 21. In this case, a tool such as a jig is connected to the connecting section 43, and a rotational force about the optical axis Ax is applied to the tool.

[0079] By applying a rotational force to the tool, the pressing member 40, which is threadedly engaged with the first region 203 via the joint 412, moves relative to the lens barrel 20 along the x-axis. This adjusts the position of the pressing member 40 in the x-axis direction. In the pressed member 40 adjusted to the desired position, the rear side 422 of the retaining part 42 contacts the lens (second lens) 303. Furthermore, the rear side of the second lens 303 partially contacts the front side of the lens 304. The rear side of the lens 304 partially contacts the front side of the lens 305. The rear side of the lens 305 contacts the rear wall surface 220 of the second storage part 22.

[0080] When the position of the pressing member 40 is adjusted to the desired position in the x-axis direction, the lenses 303, 304, and 305 of the second lens group 32 are pressed by the pressing member 40 towards the x-axis and held in place.

[0081] Furthermore, the outer diameter of the sidewall portion 41 is equal to or approximately equal to the inner diameter of the first receiving portion 21. Therefore, when a rotational force is applied to the pressing member 40, the pressing member 40 moves along the x-axis while the fixing portion 413 slides relative to the second region 204 of the first receiving portion 21. As described above, burrs generated during the opening process of the second hole portion 63 in the through hole 60 are contained within the recess 62. Therefore, the fixing portion 413 can be fitted into the second region 204 while preventing the sliding of the fixing portion 413 relative to the second region 204 from being hindered by burrs. As a result, the pressing member 40 becomes loose within the first receiving portion 21, preventing the pressing member 40 from being stored in an inclined state. Therefore, the second lens group 32 held in the pressing member 40 can be assembled into the lens barrel 20 with high precision.

[0082] Subsequently, lenses 301 and 302 of the first lens group 31 are housed within the first housing portion 21, with lens 301 pressed from the front by the front pressing ring 34. Lens 301 is pressed rearward by the front pressing ring 34, thereby bringing the first lens 302, which contacts the rear side of lens 301, into contact with the contact surface 410 of the pressing member 40. As described above, the pressing member 40 is housed within the first housing portion 21 in a state that suppresses tilting. Therefore, the first lens 302, which contacts the contact surface 410, is configured in a state that suppresses a decrease in positional accuracy.

[0083] Furthermore, as described above, the distance between the contact surface 410 and the rear side surface 422 in the x-axis direction is equal to or approximately equal to the designed distance between the first lens 302 and the second lens 303 in the x-axis direction. Thus, the first lens 302 and the second lens 303, assembled within the lens barrel 20, are positioned with a desired distance along the x-axis direction. In other words, the pressing member 40 functions as a spacer relative to the first lens 302 and the second lens 303.

[0084] The connecting portion 43 is located on a connecting portion forming surface different from the contact surface 410. Therefore, even if burrs are generated during the machining of the connecting portion 43 or during the connection between the tool and the connecting portion 43, no burrs will be generated on the contact surface 410 that contacts the first lens 302. Therefore, it is possible to suppress the first lens 302 from tilting or deviating from its desired position due to the influence of burrs. As a result, the reduction in the positional accuracy of the first lens 302 within the first storage portion 21 is suppressed.

[0085] Furthermore, the front surface 421 and the inclined surface 423, which form the connecting portion, are located at a position farther away from the first lens 302 than the contact surface 410. Therefore, even if burrs fall off during adjustment, it is possible to prevent the fallen burrs from adhering to the contact surface 410. As a result, the positional accuracy of the first lens 302 within the first receiving portion 21 is suppressed.

[0086] Furthermore, when the first lens group 31, the second lens group 32, and the pressing member 40 are assembled inside the lens barrel 20, an adhesive or similar substance is applied inside the through hole 60. As a result, the first lens group 31, the second lens group 32, and the pressing member 40 are housed and fixed inside the lens barrel 20.

[0087] <Assembly of the third lens group 33 within the lens barrel 20>

[0088] Within the third storage section 23, the lenses 306, 307, and 308 of the third lens group 33 and the spacers 50 and 51 are arranged along the optical axis Ax. When the third lens group 33 and the spacers 50 and 51 are arranged within the lens barrel 20, a rear pressing ring 35 is installed on the rear side of the lens 308.

[0089] At this time, by using a fixture or the like inserted into the through hole 70, the position of the spacer 50 in the x-axis direction and its tilt relative to the optical axis Ax are adjusted. As a result, the lenses 306, 307, and 308 disposed in the third storage section 23 can be assembled in a manner that allows the position and tilt to be in the desired state.

[0090] As described above, the inner diameter of the third receiving portion 23 is equal to or approximately equal to the outer diameter of the spacer member 50. However, the radial length of the recess 72 of the through hole 70 is larger than the burr generated during the opening machining of the second hole portion 73. Therefore, during the above adjustment, it is possible to prevent the spacer member 50 from being hindered in the x-axis direction by the burr. As a result, the spacer member 50 becomes loose within the third receiving portion 23, preventing the spacer member 50 from being stored in an inclined state. Therefore, the third lens group 33 can be assembled into the lens barrel 20 with high precision.

[0091] Furthermore, when the third lens group 33 and the spacers 50 and 51 are assembled inside the lens barrel 20, an adhesive or similar substance is applied inside the through hole 70. As a result, the third lens group 33 and the spacers 50 and 51 are housed and fixed inside the lens barrel 20.

[0092] According to the above-described embodiments, at least one of the following effects can be obtained.

[0093] (1) The lens unit 10 has a pressing member 40 disposed between a first lens 302 and a second lens 303 among a plurality of lenses 301 to 308. The pressing member 40 has a sidewall portion 41, a contact surface 410, a holding portion 42, a connecting portion 412, a linking portion 43, and a front surface 421 and an inclined surface 423 forming the linking portion. The contact surface 410 is located at one end (front side) of the sidewall portion 41 in the direction along the optical axis Ax and contacts the first lens 302. The holding portion 42 is disposed at the other end (rear side) of the sidewall portion 41 in the direction along the optical axis Ax and contacts the second lens 303 to hold the second lens 303. The connecting portion 412 is disposed along the outer periphery of the rear side of the sidewall portion 41 and is threadedly engaged with the first region 203 of the inner peripheral wall surface 202 of the lens barrel 20. A tool for rotating the pressing member 40 about the optical axis Ax is connected to the linking portion 43. The connecting part 43 is provided on the connecting part forming surface, namely the front side surface 421 and the inclined surface 423, which are different from the contact surface 410.

[0094] Therefore, the pressing member 40, as a single component, can fulfill both the function of holding the second lens group 32, which includes the second lens 303, and the function of acting as a spacer to ensure a desired distance between the first lens 302 and the second lens 303. As a result, it is not necessary to provide a spacer on top of the pressing member 40, thus reducing the number of components.

[0095] In this pressing member 40, the contact surface 410 that contacts the first lens 302 and the connecting surface where the connecting portion 43 is provided are different surfaces. Therefore, when adjusting the tool by connecting it to the connecting portion 43, no burrs are generated on the contact surface 410. Even if burrs generated by connecting the tool to the connecting portion 43 fall off, burrs can be prevented from adhering to the contact surface 410. Therefore, tilting or deviation of the first lens 302 from its desired position can be prevented. As a result, the reduction in the positional accuracy of the first lens 302 inside the lens barrel 20 is suppressed. That is, the first lens 302 and the second lens 303 can be positioned with good positional accuracy in the x-axis direction.

[0096] (2) The front surface 421 and the inclined surface 423, which form the connecting part, are located at a position farther away from the first lens 302 than the contact surface 410. As a result, even if burrs fall off during adjustment, it is possible to prevent the fallen burrs from adhering to the contact surface 410. As a result, the positional accuracy of the first lens 302 within the first receiving part 21 is suppressed.

[0097] (3) The front surface 421 and the inclined surface 423, which form the connecting part, are positioned further inward than the contact surface 410 in a radial direction intersecting the optical axis Ax. Therefore, even if burrs fall off during adjustment, not only can the detached burrs be prevented from adhering to the contact surface 410, but the contact area between the first lens 302 and the contact surface 410 can also be increased, thus suppressing the tilting of the first lens 302. As a result, the reduction in the positional accuracy of the first lens 302 can be suppressed.

[0098] (4) The connecting part 43 is a hole provided in the front side surface 421 and the inclined surface 423, which are the forming surfaces of the connecting part. As a result, the tool used for adjustment can be connected to the pressing member 40.

[0099] (5) On the pressing member 40, a fixing part 413 is provided along the outer periphery of the side wall portion 41 at a position different from the connecting part 412 in the direction along the optical axis Ax. The fixing part 413 fits into a second region 204 of the inner peripheral wall surface 202 of the lens barrel 20, which is different from the first region 203. As a result, the pressing member 40 is loosened in the first storage portion 21, and the pressing member 40 is prevented from being stored in an inclined state. Therefore, the second lens group 32 held in the pressing member 40 can be assembled in the lens barrel 20 with high precision. In addition, the second lens 303 and the first lens 302 that contacts the contact surface 410 of the pressing member 40 can be arranged at a desired distance in the x-axis direction.

[0100] (6) A radially extending through-hole 60 is provided in the lens barrel 20. The position of the through-hole 60 overlaps with the second region 204 in the direction along the optical axis Ax. As a result, the through-hole 60 used for adjusting the position of the pressing member 40 is blocked by the fixing part 413 of the pressing member 40. As a result, external light is prevented from entering the interior of the lens barrel 20 and adversely affecting the optical characteristics of the lens unit 10.

[0101] (7) The through hole 60 is composed of a first hole 61 provided on the outer peripheral wall surface 201 of the lens barrel 20, a recess 62 provided on the inner peripheral wall surface 202 of the lens barrel 20, and a second hole 63 connecting the first hole 61 and the recess 62. The length of the recess 62 along the optical axis Ax is larger than the diameter of the second hole 63. As a result, burrs generated in the second hole 63 extending toward the optical axis Ax are contained within the recess 62. Therefore, the loosening of the pressing member 40 in the first receiving portion 21 due to burrs generated in the through hole 60 is suppressed, and the pressing member 40 is stored in an inclined state. As a result, the second lens group 32 held in the pressing member 40 can be assembled in the lens barrel 20 with high precision. In addition, the second lens 303 and the first lens 302 can be arranged with a desired distance along the x-axis direction.

[0102] <Example 1>

[0103] The pressing component 40 is not limited to having Figure 3A , Figure 3B The shape shown. Specifically, the connecting portion 43 of the pressing member 40 may not be formed on the radial inner side of the side wall portion 41.

[0104] Figure 4A This is a cross-sectional view of the pressing component 40 in the first modified example. (See attached image.) Figure 4A As shown, the connecting portion 43 is provided on the flange 414 formed on the outer peripheral surface 411 of the sidewall portion 41. Specifically, the flange 414 is provided on the fixing portion 413 of the sidewall portion 41. That is, the connecting portion 43 is formed on the radially outer side of the sidewall portion 41. The connecting portion 43 is provided on the front side surface 415 of the flange 414. That is, the front side surface 415 is the connecting portion forming surface. Similar to the embodiment, the connecting portion 43 can be a through hole, a recess, or a protrusion. In addition, the other structures of the pressing member 40 are the same as those in the embodiment.

[0105] Figure 4B This is a cross-sectional view of other examples of the pressing component 40 in the first modified example. (See also...) Figure 4BAs shown, the connecting portion 43 is disposed radially outward of the sidewall portion 41 and at a position closer to the x-axis + side than the contact surface 410. Specifically, the flange 414 is connected to the connecting portion 44 formed on the outer peripheral surface 411 of the sidewall portion 41. The connecting portion 44 is cylindrical in shape with an inner diameter larger than the outer diameter of the contact surface 410 and a wall surface extending from the end of the outer peripheral surface 411 on the x-axis + side along the x-axis direction toward the x-axis + side.

[0106] The flange 414 is connected to the end of the connecting portion 44 on the x-axis + side. The inner diameter of the flange 414 is larger than the outer diameter of the contact surface 410. In this case, the connecting portion 43 is also provided on the front surface 415 of the flange 414. That is, the front surface 415 is the connecting portion forming surface. Similar to the embodiment, the connecting portion 43 can be a through hole, a recess, or a protrusion. In addition, the other structures of the pressing member 40 are the same as in the embodiment.

[0107] In addition, Figure 4B In the example shown, the front side 415 of the flange 414 is positioned closer to the x-axis than the contact surface 410. However, the front side 415 and the contact surface 410 may also be formed at equal or approximately equal positions in the x-axis direction.

[0108] With the above-described structure, the position of the pressing member 40 along the x-axis can be adjusted using the connecting portion 412 of the sidewall portion 41. Furthermore, the pressing member 40 is fixed and stored within the first storage portion 21 by engaging the fixing portion 413 of the sidewall portion 41 with the second region 204 of the first storage portion 21. As a result, in the first modified example, the same effects (1), (4) to (7) as those obtained by the embodiment can also be obtained.

[0109] <Second Variation>

[0110] Figure 5 This is a perspective view of the lens unit 10 in the second modification. In the second modification, the lens barrel 20 does not have a through hole 60. Even in this case, the position along the x-axis can be adjusted by rotating the pressing member 40 about the optical axis Ax. Furthermore, the pressing member 40 is fixed and stored in the first storage portion 21 by engaging the fixing portion 413 with the second region 204 of the first storage portion 21. As a result, the lens unit 10 in the second modification can also achieve the same effects as those obtained through the embodiments (1) to (5).

[0111] In the second variation, a through hole 70 is formed, the same as in the embodiment. Therefore, similarly to the embodiment, the spacer 50 becomes loose within the third receiving portion 23, preventing the spacer 50 from being stored in an inclined position. Thus, the third lens group 33 can be assembled into the lens barrel 20 with high precision.

[0112] Furthermore, the length of the recess 72 along the optical axis Ax is shorter than the length of the spacer member 50 in the x-axis direction. As a result, the end of the through hole 70 on the optical axis Ax side is blocked by the spacer member 50. Therefore, it is possible to suppress external light from entering the interior of the lens barrel 20 through the through hole 70, thereby suppressing any adverse effects on the optical characteristics of the lens unit 10.

[0113] Alternatively, the lens unit 10 of the second modification may also have the pressing member 40 of the first modification.

[0114] In the foregoing, various embodiments and modifications have been described, but the present invention is not limited to these. Other embodiments considered within the scope of the technical concept of the present invention are also included within the scope of the present invention.

[0115] Alternatively, this technology can adopt the following structure.

[0116] (1) A lens unit comprising: a plurality of lenses, the plurality of lenses including a first lens and a second lens; a lens barrel housing the plurality of said lenses; and a pressing member disposed between said first lens and said second lens, said pressing member having: a sidewall portion having a cylindrical shape centered on the optical axis of the plurality of said lenses; a contact surface located at one end of the sidewall portion along the optical axis and contacting said first lens; a holding portion disposed at the other end of the sidewall portion along the optical axis and holding said second lens by contacting said second lens; a connecting portion disposed along the outer periphery of said other end of the sidewall portion and threadedly engaged with a first region of the inner peripheral wall surface of the lens barrel; and a connecting portion forming surface, which is different from said contact surface and is provided with a connecting portion for connecting to a tool for rotating said pressing member about the optical axis.

[0117] (2) The lens unit according to (1), wherein the connecting portion forming surface is disposed at a position further away from the first lens than the contact surface.

[0118] (3) The lens unit according to (1) or (2), wherein the connecting portion forming surface is disposed in a radial direction intersecting the direction along the optical axis at a position closer to the contact surface.

[0119] (4) The lens unit according to any one of (1) to (3), wherein the connecting portion is a hole provided on the forming surface of the connecting portion.

[0120] (5) The lens unit according to any one of (1) to (4), wherein the pressing member is provided with a fixing part along the outer periphery of the side wall portion at a position different from the connecting part in the direction along the optical axis, and the fixing part is fitted into a second region different from the first region on the inner peripheral wall surface of the lens barrel.

[0121] (6) The lens unit according to (5) wherein a through hole is provided on the lens barrel along the radial direction, the through hole having: a first hole portion provided on the outer peripheral wall side of the lens barrel; a recess portion provided on the inner peripheral wall side of the lens barrel; and a second hole portion connecting the first hole portion and the recess portion, wherein the length of the recess portion along the optical axis is greater than the diameter of the second hole portion.

[0122] (7) The lens unit according to (6), wherein the position of the through hole overlaps with the second region in the direction along the optical axis.

Claims

1. A lens unit, comprising: Multiple lenses, including a first lens and a second lens; A lens barrel, which houses multiple of the aforementioned lenses; and A pressing component is disposed between the first lens and the second lens. The pressing component has: The sidewall portion is cylindrical with the optical axis of the plurality of lenses centered thereon; The contact surface, located at one end of the sidewall portion along the optical axis, contacts the first lens; A holding part is provided at the other end of the sidewall portion along the optical axis, and holds the second lens by contacting the second lens; A connecting portion, which is disposed along the outer periphery of the other end side of the sidewall portion, is threadedly engaged with a first region of the inner peripheral wall surface of the lens barrel; and The connecting portion is formed on a surface that is different from the contact surface, and is provided with a connecting portion that connects to a tool that causes the pressing member to rotate about the optical axis.

2. The lens unit according to claim 1, wherein, The connecting portion forming surface is located at a position farther away from the first lens than the contact surface.

3. The lens unit according to claim 2, wherein, The connecting portion forming surface is positioned on the inner side of the contact surface in a radial direction intersecting the direction along the optical axis.

4. The lens unit according to claim 3, wherein, The connecting portion is a hole provided on the forming surface of the connecting portion.

5. The lens unit according to claim 4, wherein, The pressing component has a fixing part located at a position different from the connecting part along the optical axis on the outer periphery of the side wall portion. The fixing part is fitted into a second region on the inner peripheral wall of the lens barrel, which is different from the first region.

6. The lens unit according to claim 5, wherein, A through hole is provided on the lens barrel along the radial direction. The through hole has: The first hole is located on the outer peripheral wall of the lens tube; A recess, which is provided on the inner peripheral wall surface of the lens barrel; and The second hole connects the first hole and the recess. The length of the recess along the optical axis is greater than the diameter of the second hole.

7. The lens unit according to claim 6, wherein, Along the direction of the optical axis, the position of the through hole overlaps with the second region.

Images