WO2008026677A1

WO2008026677A1 - Lens holding device

Info

Publication number: WO2008026677A1
Application number: PCT/JP2007/066860
Authority: WO
Inventors: Eiji Kurimoto
Original assignee: Sharp Kabushiki Kaisha
Priority date: 2006-08-31
Filing date: 2007-08-30
Publication date: 2008-03-06

Abstract

A lens holding device having a lens housing (12) with one opening (14) in the direction of the optical axis (J) and a lens (11) press-fitted into the lens housing (12) from the opening (14). The lens housing (12) has a tapered inner peripheral surface (16), a holding surface (17), and a positioning section (18). The lens (11) is press-fitted into the lens housing (12) from the one opening (14) into the direction in which the inner diameter of the tapered inner peripheral surface (16) increases. The lens (11) stops at a predetermined position, or at a contact surface (18A) of the positioning section (18), and a holding surface (17) engages an outer peripheral surface (11A) of the lens (11) to hold it.

Description

Specification

Lens holding device

Technical field

[0001] The present invention relates to a lens holding device for holding a lens in a lens barrel.

Background art

In various optical devices such as cameras, a lens barrel structure is used as an efficient structure for fixing a lens with high accuracy. For example, as a method of fixing a lens having a circular shape, a lens barrel having an inner diameter that is approximately equal to the diameter of the lens or smaller than the diameter of the lens is used.

[0003] Further, a structure shown in FIG. 7 is used for fixing a lens used in an optical device or the like that requires extremely high-precision assembly (see Japanese Patent Laid-Open No. 2002-250853). In this conventional example, an inclined portion 103 inclined in the direction of the optical axis K is provided on the inner wall portion of the lens barrel 102, and the lens 101 is pushed into the optical axis direction from the opening 107 larger than the lens outer diameter (press-fit). . Then, the lens 101 is held in the lens barrel 102 by engaging the inclined surface of the outer peripheral portion 105 of the lens 101 with the inclined portion 103 of the inner wall portion of the lens barrel 102 at a position where the lens 101 is fixed. .

In this holding structure, an opening 107 that is an entrance into which the lens 101 is pushed is wider than an opening 108 on the opposite side, and the lens fixing portion 104 between the openings 107 and 108 is a lens outer peripheral portion 105. Engage with. As a result, the lens 101 does not move relative to the lens barrel 102, and the lens 101 can be easily fixed to the lens barrel 102.

[0005] However, in the conventional example, it is necessary to process the outer peripheral portion 105 of the lens 101 and the inner wall portion 102A of the lens barrel 102 with extremely high accuracy. The reason for this is that if an error occurs in the angle between the outer peripheral portion 105 of the lens 101 and the fixing portion 104 of the lens barrel 102 that is inclined with respect to the optical axis direction, This is because the fixed position at the position is greatly deviated from the predetermined position.

[0006] In the conventional example described above, although the operation of assembling the lens 101 to the lens barrel 102 is easy, the high-precision processing increases the cost and the overall processing is not easy. Assembling work is not efficient! /

[0007] When the lens 101 is made of glass and the lens barrel 102 is made of a soft material such as resin, the lens 101 is assembled from a wide diameter portion of the inner wall portion 102A to a narrow location. In the course of going, there is a risk that the inner wall 102A of the lens barrel 102 will be scraped at the point where the lens 101 contacts the inner wall 102A of the lens barrel 102. When the inner wall 102A of the lens barrel 102 is shaved, the tilt and eccentricity of the lens 101 with respect to the lens barrel 102 are unexpectedly affected by the accumulation of shore IJ grime and the like generated from the lens barrel 102. The lens cannot be fixed at the position. In addition, the shavings may adhere to the lens surface and cause a decrease in optical performance.

Disclosure of the invention

Problems to be solved by the invention

[0008] Therefore, an object of the present invention is to provide a lens holding device capable of improving the positional accuracy for fixing the lens to the lens barrel.

Means for solving the problem

In order to solve the above-described problem, a lens holding device according to the present invention is fixed to a lens barrel having an opening at least in one of the optical axis directions, and press-fitted into the lens barrel from the one opening. With at least one lens,

The lens barrel extends from the one opening portion toward the other side in the optical axis direction, and has a tapered inner peripheral surface extending from the tapered inner peripheral surface to the other in the optical axis direction. And a holding surface that contacts the outer peripheral surface of the lens and holds the lens, and further extends inward in the radial direction intersecting the holding surface and in the optical axis direction of the lens. And a positioning portion including a contact surface for positioning the lens in the optical axis direction by coming into contact with the other surface from the outside in the radial direction.

According to the lens holding device of the present invention, the lens is press-fitted into the lens barrel in a direction in which the inner diameter of the tapered inner peripheral surface increases from one opening, and the positioning portion abuts at a predetermined position. The lens stops at the surface and the holding surface comes into contact with the outer peripheral surface of the lens to hold the lens. Therefore, the holding state of holding the lens at a predetermined position in the lens barrel can be easily and surely achieved, and the positioning of the lens can be made highly accurate. [0011] Further, when the lens is press-fitted from one opening in the optical axis direction of the lens barrel, the tapered inner peripheral surface of the lens barrel is expanded in diameter toward the other in the optical axis direction. The risk of the inner peripheral surface of the lens barrel being shaved at the outer edge of the lens can be reduced. Therefore, stable lens press-fitting and lens holding with respect to the lens barrel can be realized. At the same time, it is possible to suppress the possibility of lens tilting or shavings adhering to the lens surface due to the influence of Shaw IJ grime, etc., and to prevent deterioration of optical characteristics.

[0012] In addition, a lens holding device according to an embodiment includes a plurality of lenses press-fitted and fixed in the lens barrel, and is further disposed between two lenses adjacent in the optical axis direction. A spacer is provided to define the distance between the two lenses.

[0013] According to the lens holding device of this embodiment, since the spacer defines the distance between two lenses adjacent in the optical axis direction, a lens in which a plurality of lenses are accurately positioned in the lens barrel. Can be realized.

[0014] In the lens holding device according to one embodiment, the lens is press-fitted into the tapered inner peripheral surface from one opening in the optical axis direction of the lens barrel, and is elastically deformed by the holding surface. It is held in the lens barrel.

According to the lens holding device of this embodiment, even when the lens is held on the holding surface of the lens barrel, the lens is fixed by the elastic force of the lens barrel, so that the lens is fixed with reference to the inner diameter of the lens barrel. Will be. Therefore, in the range where the elastic force of the lens barrel is not lost, it is possible to hold the lens with less eccentricity regardless of the deviation of the outer diameter of the lens.

In the lens holding device of one embodiment, since the spacer is integrated with the lens barrel, assembly is easy.

[0017] In the lens holding device of one embodiment, since the spacer is separate from the lens barrel, the distance between lenses can be changed by replacing the spacer.

[0018] Further, in the lens holding device of one embodiment, since the positioning portion is integrated with the lens barrel, there is no fear that the positioning portion is displaced from or detached from the lens barrel.

In the lens holding device of one embodiment, since the positioning unit is separate from the lens barrel and attached to the lens barrel, the lens is removed by removing the positioning unit from the lens barrel. The lens is mirrored by pushing it further in the optical axis direction from the holding surface. It can be easily taken out from the other opening of the tube.

[0020] In addition, in the lens holding device of one embodiment, the inner peripheral surface of the one opening in the optical axis direction has a chamfered portion, so that it is easy to press-fit the lens.

In the lens holding device of one embodiment, since the lens is made of glass or resin, when made of glass, the refractive index is high, the thickness can be reduced, and the secular change is small. When it becomes a lens and is made of a resin lens, it is light and hard to break and easy to process.

[0022] In the lens holding device of one embodiment, the lens barrel has an inner peripheral surface showing a substantially circular shape in a cross section by a surface orthogonal to the optical axis, and the lens is orthogonal to the optical axis. The cross section by the surface has a cross section that is substantially circular.

[0023] According to this embodiment, a substantially circular lens barrel and a substantially circular lens are provided, and a lens holding device having a substantially cylindrical shape as a whole is obtained.

[0024] In the lens holding device according to one embodiment, the lens barrel has an inner peripheral surface showing a substantially elliptical shape in a cross section by a surface orthogonal to the optical axis, and the lens is orthogonal to the optical axis. The cross section by the surface has a cross section that is substantially elliptical.

[0025] According to this embodiment, a substantially elliptical lens barrel and a substantially elliptical lens are provided, and the lens holding device has a substantially elliptical cylindrical shape as a whole.

[0026] In the lens holding device of one embodiment, the lens barrel has an inner peripheral surface showing a substantially square shape in a cross section by a surface orthogonal to the optical axis, and the lens is orthogonal to the optical axis. The cross section by the surface has a cross section having a substantially square shape.

[0027] According to this embodiment, the substantially square lens barrel and the substantially quadrangular lens are provided, and the lens holding device has a substantially quadrangular prism shape as a whole.

[0028] Further, in the lens holding device of one embodiment, the outer diameter of the lens is Dl (mm), and the inner diameter of one opening in the optical axis direction of the lens barrel for press-fitting the lens is D2 (mm) If the inner diameter of the holding surface of the lens barrel is D3 (mm) while holding the lens! /, N! /, 0.990D1 <D2 0.995D3 (1)

0.995DK D3 <D1 (2)

Meet the above formulas (1) and (2)!

[0029] According to this embodiment, the inner diameter of one opening of the lens barrel exceeds 99% of the outer diameter of the lens. Therefore, when the lens is press-fitted into one opening of the lens barrel, the lens can be press-fitted only by elastically deforming the opening by a dimension smaller than 1% of the outer diameter of the lens. Also, since the inner diameter of one opening of the lens barrel is less than 99.5% of the inner diameter of the lens barrel holding surface when the lens is not held, the tapered inner peripheral surface of the lens barrel holds the lens. In the absence, the shape is tapered from the holding surface toward the opening. Furthermore, since the inner diameter of the holding surface without holding the lens exceeds 99.5% of the outer diameter of the lens and less than 100% of the outer diameter of the lens, the holding surface does not hold the lens. The outer peripheral surface of the lens is held from the radially outer side by elastic deformation.

[0030] In the lens holding device of one embodiment, the holding surface of the lens barrel has at least one concave portion that is recessed outward in the radial direction and that extends by a predetermined dimension in the optical axis direction and the circumferential direction. Have.

[0031] According to this embodiment, even if there is a difference between the shape of the holding surface and the shape of the outer peripheral surface of the lens, the presence of the concave portion makes it easier to absorb the difference in shape between the holding surface and the outer peripheral surface of the lens. .

In the lens holding device of one embodiment, since the lens has a chamfered edge, it is easy to press-fit into the lens barrel from the opening.

[0033] In the lens holding device of one embodiment, the lens holding device is disposed between at least two lenses press-fitted into the lens barrel and the two lenses adjacent in the optical axis direction. And two lens surfaces facing each other and three or more spheres contacting the inner peripheral surface of the lens barrel, the spheres including a magnetic material.

[0034] According to this embodiment, the three or more spheres serve as a spacer that defines the distance between two lenses adjacent in the optical axis direction. Can be positioned accurately. Further, by disposing a magnet that exerts a magnetic force on the sphere outside the barrel, it is possible to restrict the movement of the sphere in the circumferential direction and the radial direction. In other words, the magnetic force of the magnet can position the sphere at a predetermined position and prevent the spheres from moving. For example, during assembly, the interval between the lenses can be maintained with high accuracy. This makes it possible to maintain the lens and suppress the lens collapse.

In the lens holding device of one embodiment, at least two lenses press-fitted into the lens barrel, the contact surface of the positioning unit, and the positioning unit are adjacent to each other in the optical axis direction. The lens has a contact surface, the lens surface of the lens facing the contact surface, and three or more spheres that contact the inner peripheral surface of the lens barrel. The sphere includes a magnetic material.

[0036] According to this embodiment, the three or more spheres are arranged between the positioning portion and the lens, and have a lens surface shape (curved surface shape, planar shape, etc.) or a positioning portion shape of the lens. Regardless, it contacts the lens surface, the inner peripheral surface of the lens barrel, and the contact surface of the positioning portion. Therefore, it is possible to maintain a state in which the distance between the lens and the positioning portion is maintained with high accuracy, and to suppress lens collapse.

The invention's effect

According to the lens holding device of the present invention, the lens is press-fitted into the lens barrel in a direction in which the inner diameter of the tapered inner peripheral surface increases from one opening, and the positioning portion abuts at a predetermined position. The lens stops at the surface and the holding surface comes into contact with the outer peripheral surface of the lens to hold the lens. Therefore, it is possible to easily and surely achieve a holding state in which the lens is held at a predetermined position in the lens barrel, and to highly accurately position the lens. When the lens is press-fitted from one opening in the optical axis direction of the lens barrel, the tapered inner peripheral surface of the lens barrel expands toward the other in the optical axis direction. This can reduce the risk of the inner peripheral surface of the lens barrel being shaved. Therefore, stable lens press-fitting and lens holding with respect to the lens barrel can be realized. At the same time, it is possible to suppress the possibility of lens tilting or shaving due to the influence of shading and the like, and the deterioration of optical characteristics.

[0038] Further, in the case of having three or more spheres containing a magnetic material as a spacer for defining the distance between the lenses, it is possible to control the position of the sphere from the outside of the lens barrel by magnetic force. In addition, it is possible to suppress the lens collapse caused by the positional deviation of the sphere without being related to the shape of the lens surface (curved surface shape or planar shape). In addition, one opening of the lens barrel serves as an entrance for press-fitting, so that the force S is narrow, and when there are three or more spheres as the spacer, compared to the case with a ring-shaped spacer, It becomes easy to arrange in the lens barrel.

Brief Description of Drawings

FIG. 1 is a cross-sectional view showing a first embodiment of the lens holding device of the present invention.

FIG. 2 is a cross-sectional view showing a modification of the first embodiment. FIG. 3 is a cross-sectional view showing another modification of the first embodiment.

FIG. 4 is a cross-sectional view showing a second embodiment of the lens holding device of the present invention.

FIG. 5 is a cross-sectional view showing a third embodiment of the lens holding device of the present invention.

FIG. 6 is a cross-sectional view showing a fourth embodiment of the lens holding device of the present invention.

FIG. 7 is a cross-sectional view of a conventional lens holding device.

FIG. 8 is a cross-sectional view showing a fifth embodiment of the lens holding device of the invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

[0041] (First embodiment)

FIG. 1 shows a longitudinal section of a lens holding device as a first embodiment of the present invention. Here, the longitudinal section is a section by a plane including the optical wheel. In this lens holding device, one lens 11 is held in a lens barrel 12.

As shown in FIG. 1, the lens 11 is a biconvex lens having one convex lens surface 11B and the other convex lens surface 11C in the optical axis direction. The lens barrel 12 is hollow and has one opening 14 in the optical axis direction and the other opening 15 in the optical axis direction. The opening 15 is narrower than the opening 14. Further, the lens barrel 12 extends from the opening 14 to the other side in the optical axis direction, and from the tapered inner peripheral surface 16 to the other side in the optical axis direction. And a holding surface 17 that holds the lens 11 in contact with the outer peripheral surface 11 A of the lens 11 from the outside in the radial direction.

Further, the lens barrel 12 has a positioning portion 18 that forms the other opening 15. The positioning portion 18 has an abutting surface 18A that forms the other end portion of the lens barrel 12 in the optical axis direction and extends inward in the radial direction substantially orthogonal to the holding surface 17. The contact surface 18A contacts the other convex lens surface 11C in the optical axis direction of the lens 11 to position the lens 11 in the optical axis direction.

In this embodiment, the inner peripheral surface of the lens barrel 12 has a substantially cylindrical shape. The outer peripheral surface 11A of the lens 11 is also substantially cylindrical. The inner diameter of the opening 14 is smaller than the outer diameter of the lens 11 by a predetermined dimension. The holding surface 17 that forms the inner wall of the lens barrel 12 holds the outer peripheral surface 11 A of the lens 11 by pressing the outer peripheral surface 11 A of the lens 11 radially inward with an elastic restoring force radially inward. And! Note that, as shown in FIG. 2, an adhesive 25 is applied to a portion where the peripheral edge of the convex lens surface 11B of the lens 11 and the inner peripheral surface 16 are in contact with each other, and the holding state of the lens 11 on the lens barrel 12 is further strengthened. You may do it. Further, the holding state of the lens 11 on the lens barrel 12 may be further strengthened by force, crimping or the like.

In this embodiment, the lens 11 is pressed into the tapered inner peripheral surface 16 from the opening 14 of the lens barrel 12. The lens 11 may be a resin lens or a glass lens. The outer diameter Dl (mm) of the lens 11 is larger than the inner diameter D2 (mm) of the opening 14 of the lens barrel 12 by a predetermined dimension, but the difference between the inner diameter of the opening 14 and the outer diameter of the lens 11 (D1 —D2) and the material of the lens barrel 12 can be made suitable to eliminate the possibility of the lens barrel 12 being scraped when the lens 11 is press-fitted. That is, the lens 11 without plastic deformation of the lens barrel 12 can be inserted into the lens barrel 12, and the lens barrel 12 is limited to elastic deformation. An example of the material of the lens barrel 12 is resin, but it may be made of metal.

[0047] As a specific example, when the lens 11 is made of glass and the lens barrel 12 is also made of resin such as polycarbonate, the lens outer diameter D1 is 4.0 (mm), and the inner diameter D2 of the opening 14 is 3.6-3. In the case of 8 mm, the lens 11 can be press-fitted without cutting the lens barrel 12. This is due to the selection of an appropriate lens material and lens barrel material, and the setting of the difference between the lens outer diameter D1 and the lens barrel inner diameter D2.

The lens 11 is inserted into the tapered inner peripheral surface 16 of the lens barrel 12 whose inner diameter is increased from the opening 14 having the inner diameter D2 in the optical axis direction until the lens 11 contacts the contact surface 18A of the positioning portion 18. It is done. Here, since the inner diameter of the taper inner peripheral surface 16 increases toward the other side in the optical axis direction in which the lens 11 is inserted, the case where the lens is pushed in the direction in which the inner diameter is narrowed as in a conventional lens barrel and In contrast, it is possible to reduce the risk of the peripheral edge (edge) of the convex lens surface 11C of the lens 11 strongly rubbing the inner wall of the lens barrel 12, and to reduce the risk of scraping the inner wall of the lens barrel 12. As a result, it is possible to eliminate the influence on the tilt and decentering of the lens 11 and the stain on the lens surface due to the occurrence of the shore IJ mark.

In the above specific example, it is desirable that the inner diameter D3 (mm) of the holding surface 17 adjacent to the contact surface 18A of the positioning portion 18 of the lens barrel 12 is 3.8 to 4.0 (mm). In the range, the lens 11 is in a state in which the inner wall of the lens barrel 12 is only elastically deformed and the lens can be held by elastic force. In the lens holding device of this embodiment, the outer diameter of the lens 11 is Dl (mm), and the inner diameter of one opening 14 in the direction of the optical wheel of the lens barrel 12 into which the lens 11 is press-fitted is D2 ( mm), and when the inner diameter of the holding surface 17 of the lens barrel 12 without holding the lens 11 is D3 (mm), it is desirable to satisfy the following expressions (1) and (2).

0.990D1 <D2 0.995D3… (1)

0.995DK D3 <D1 (2)

[0051] When the expressions (1) and (2) are satisfied, the inner diameter D2 of the one opening 14 of the lens barrel 12 exceeds 99% of the outer diameter D1 of the lens 11. Therefore, the lens barrel 12 When the lens 11 is pressed into one of the openings 14, the lens 11 can be press-fitted only by elastically deforming the opening 14 by a dimension smaller than 1% of the outer diameter D1 of the lens 11. In addition, the inner diameter D2 of one opening 14 of the lens barrel 12 is less than 99.5% of the inner diameter D3 of the lens 12 on the holding surface 17 of the lens barrel 12 when the lens 11 is not held. When the lens 11 is not held, the inner peripheral surface 16 is directed toward the opening 14 from the holding surface 17 and has a tapered shape. In addition, the inner diameter D3 of the holding surface 17 in the state of holding the lens 11 in a smooth state exceeds 99.5% of the outer diameter D1 of the lens 11! /, And is less than 100% of the outer diameter D1 of the lens 11. Therefore, the holding surface 17 holds the outer peripheral surface 11A of the lens 11 from the outside in the radial direction by elastic deformation when the lens 11 is held.

[0052] Further, as shown in Fig. 3, the inner peripheral surface of the opening portion 14 of the lens barrel 12 is chamfered as a structure of the lens barrel 12 that allows the lens 11 to be pushed and pressed more smoothly. A chamfered portion 36 may be formed. The chamfered portion 36 can reduce the difference between the inner diameter D2 of the lens barrel 12 and the outer diameter D1 of the lens 11 at the opening portion 14, and can reduce the pushing pressure required for press-fitting, so that the lens 11 is held more easily. It is possible to push it in.

The size and angle of the chamfer 36 of the opening 14 shown in FIG. 3 are not particularly limited, but the optical axis of the lens 11 overlaps the central axis of the lens barrel 12 in the opening 14 at the entrance. In addition, it is desirable that the posture of the lens 11 can be controlled. It is appropriate that the inner diameter D2 of the opening 14 of the lens barrel 12 is approximately equal to the outer diameter D1 of the lens 11 by the chamfered portion 36 of the opening 14. If the inner diameter D2 of the opening 14 of the lens barrel 12 is too small than the outer diameter D1 of the lens 11, the effect of the chamfer 36 will be reduced.If the inner diameter D2 of the opening 14 is larger than the outer diameter D1 of the lens 11, The tilt 11 is easily pushed into the lens barrel 12 in a tilted state, and tilt control becomes difficult.

[0054] In the first embodiment, the force described with the lens 11 as a biconvex lens can be applied to any lens shape of the lens 11. For example, the lens can be a plano-convex lens, a meniscus lens, An aspherical lens may be used. Further, in the above embodiment, the inner peripheral surface of the lens barrel 12 has a cylindrical shape, but the inner peripheral surface of the lens barrel 12 may have an elliptical cylindrical shape or a substantially rectangular cylindrical shape. In the above embodiment, the lens 11 is circular, but may be elliptical or substantially rectangular. Further, a circumferential groove (not shown) extending in the circumferential direction may be formed on the holding surface 17 of the lens barrel 12. In this case, the positional deviation of the lens 11 can be suppressed by the circumferential groove of the holding surface 17. Further, chamfering may be performed on the peripheral edge of at least one of the convex lens surface 11B and the convex lens surface 11C of the lens 11. In this case, it becomes easy to press-fit the lens 11 into the lens barrel 12 from the opening 14.

[0055] (Second embodiment)

Next, FIG. 4 shows a longitudinal section of a second embodiment of the lens holding device of the present invention. The lens barrel 42 included in the lens holding device of the second embodiment has a hollow cylindrical shape, and has one opening 43 in the optical axis direction and the other opening 44 in the light $ direction. One opening 43 serves as an entrance for press-fitting the lens 41 into the lens barrel 42.

In the second embodiment, an annular positioning portion 45, which is a separate body from the lens barrel 42, is attached to the inner peripheral surface of the opening 44 of the lens barrel 42. This second embodiment differs from the first embodiment described above in that it has a positioning portion 45 that is separate from the lens barrel 42.

On the other hand, the opening 43 of the lens barrel 42 of the second embodiment has the same configuration as the opening 14 of the lens barrel 12 of the first embodiment, and the lens barrel 42 of the second embodiment has the same structure. The tapered inner peripheral surface 46 and the holding surface 47 have the same configuration as the tapered inner peripheral surface 16 and the holding surface 17 of the first embodiment. The lens 41 included in the second embodiment has the same configuration as the lens 11 included in the first embodiment.

In the second embodiment, the positioning portion 45 separate from the lens barrel 42 has a contact surface 45 A extending inward in the radial direction substantially orthogonal to the holding surface 47. The contact surface 45A contacts the other convex lens surface 41C in the optical axis direction of the lens 41 to position the lens 41 in the optical axis direction. In the second embodiment, the positioning portion 45 is a separate member from the lens barrel 42. The material of the positioning part 45 can be different from the material of the lens barrel 42. Then, the positioning portion 45 having the contact surface 45A subjected to extremely high precision processing is installed independently of the lens barrel 42.

[0059] In general, the lens barrel is mainly manufactured by molding from the viewpoint of cost and ease of manufacture. Further, the lens barrel in the present invention can be mainly manufactured by molding which is desirably made of a relatively elastic material such as resin.

However, in the molding process, in the structure in which the contact surface of the positioning portion is formed on the inner peripheral surface of the lens barrel, the manufacturing cost increases due to the complicated shape of the inner peripheral surface of the lens barrel. The demand for the degree also increases.

On the other hand, in the second embodiment, since the positioning portion 45 having the contact surface 45A is a separate structure from the lens barrel 42, the lens barrel 42 may be a simple cylindrical shape. Can be made easily.

[0062] In the second embodiment, the contact surface 45A is provided as a step before the lens 41 is press-fitted from one opening 43 of the lens barrel 42 into the holding position by the holding surface 47 through the tapered inner peripheral surface 46. The positioning portion 45 is attached to the inner peripheral surface of the other opening 44 of the lens barrel 42. In this second embodiment, the positioning portion 45 has a ring-shaped contact surface 45A, and this ring-shaped contact surface 45A has the same function as the contact surface 18A of the positioning portion 18 of the first embodiment. It is possible to have

[0063] Note that the shape of the positioning portion is not limited to the ring shape, and may be various shapes such as a film shape, a wire rod shape, a cube shape, and a spherical shape as long as it plays a role of positioning. The power to do S.

[0064] In this embodiment, the positioning portion 45 having the contact surface 45A is made of metal, and the thickness and shape of the positioning portion 45 are processed with extremely high accuracy. However, the positioning part 45 having the abutment surface 45A is not limited to metal, and it is possible to freely select a material such as resin, metal, glass, etc., and it is optimal depending on the required accuracy and shape. The power is selected by selecting the material.

In this embodiment, the positioning portion 45 having the contact surface 45A is disposed and attached to the inner peripheral surface of the other opening 44 of the lens barrel 42, and then the lens 41 is made in the same manner as in the first embodiment. ,mirror The tube 42 is inserted and pressed into the holding surface 47 through the tapered inner peripheral surface 46 from the opening 43. As a result, the second embodiment can realize the holding state of the lens 41 as shown in FIG.

In the second embodiment, as in the first embodiment, the lens 41 can be held by the inertial force of the lens barrel 42, and the positioning portion 45 having the contact surface 45A is provided. Both material and shape can be freely selected. Therefore, the positioning unit 45 can serve as a diaphragm in the optical system, for example. In the second embodiment, a member having a shirter function or the like can be used as the positioning portion 45 having the contact surface 45A. Further, if the contact surface 45A of the positioning portion 45 is a contact surface having a complicated curved surface that is in close contact with the lens surface 41C of the lens 41, the positioning function for the lens 41 can be improved.

Further, when the positioning portion 45 having the contact surface 45A is separated from the lens barrel 42 as in the second embodiment, the positioning portion 45 having the contact surface 45A is provided on the inner wall of the lens barrel 42. A state in which the lens barrel 42 is held on the inner peripheral side by an elastic force may be employed. In this case, the lens 41 press-fitted into the holding surface 47 from one opening 43 is further pushed toward the other opening 44, so that the positioning portion 45 and the lens 41 forming the contact surface 45A are removed from the lens barrel 42. It can be easily removed. Therefore, the lens 41 can be easily reused.

[0068] (Third embodiment)

Next, FIG. 5 shows a longitudinal section of a third embodiment of the lens holding device of the present invention. The lens holding device according to the third embodiment has a structure that holds two lenses 51 and 52 in a lens barrel 53. The lens barrel 53 of the third embodiment has a hollow cylindrical shape and has one opening 56 in the direction of the optical wheel and the other opening 57 in the optical axis direction. One opening 56 serves as an entrance for press-fitting the lenses 51 and 52 into the lens barrel 53.

As shown in FIG. 5, the first lens 51 is a biconvex lens having one convex lens surface 51B and the other convex lens surface 51C in the optical axis direction. The second lens 52 is a single-convex lens having one convex lens surface 52B in the optical axis direction and the other flat lens surface 52C in the optical axis direction. In addition, one opening 56 of the lens barrel 53 is narrower than the other opening 57. The lens barrel 53 is made of a material having an appropriate elastic force, and extends from the opening 56 to the other side in the optical axis direction. A tapered inner peripheral surface 58 having an inner diameter increasing toward the other, and extending from the tapered inner peripheral surface 58 toward the other in the optical axis direction and radially outward to the outer peripheral surfaces 52A and 51A of the lenses 52 and 51. The holding surface 60 holds the lenses 52 and 51 in contact with each other with force.

In addition, the lens barrel 53 has a positioning portion 61 that forms the other opening 57. The position determining portion 61 has an abutting surface 61A that forms the other end portion of the lens barrel 53 in the optical axis direction and extends inward in the radial direction substantially orthogonal to the holding surface 60. The contact surface 61A contacts the other convex lens surface 51C in the optical axis direction of the first lens 51 to position the first lens 51 in the optical axis direction.

In the third embodiment, the inner peripheral surface of the lens barrel 53 is substantially cylindrical. The outer peripheral surfaces 51A and 52A of the lenses 51 and 52 are also substantially cylindrical. The inner diameter of one opening 56 is smaller than the outer diameters of the lenses 51 and 52 by a predetermined dimension. The holding surface 60 that forms the inner wall of the lens barrel 53 presses the outer peripheral surfaces 51A and 52A of the lenses 51 and 52 radially inward with elastic restoring force radially inward. Hold the outer peripheral surface 51 A, 52A!

In the third embodiment, the ring-shaped spacer 63 is disposed between the first lens 51 and the second lens 52. The ring-shaped spacer 63 has an upper surface 63A as a contact surface that contacts the flat lens surface 52C of the second lens 52 and a lower surface 63B as a contact that contacts the convex lens surface 51B of the first lens 51. It is a surface. This ring-shaped spacer 63 defines the distance between two lenses 51 and 52 adjacent in the optical axis direction.

[0073] Here, since the spacer 63 determines the distance between the lenses 51 and 52 and the position of the second lens 52, it is desirable that the spacer 63 be a high-precision processed product, but achieves the required required accuracy. If possible, the material is not limited and the shape need not be limited to a ring.

In the lens holding device according to the third embodiment, first, as described in the first embodiment, the first lens 51 is moved from one opening 56 through the tapered inner peripheral surface 58 to the convex lens surface 51C. Is press-fitted until it comes into contact with the contact surface 61A of the positioning portion 61, and the outer peripheral surface 51A is held by the holding surface 60. Here, the lens barrel 53 has moderate elasticity, and plastic deformation does not occur even when the first lens 51 is press-fitted. The inner diameter of the lens barrel 53 is the narrowest in the opening 56 between the one opening 56 where the lens is press-fitted and the position where the lens is fixed (that is, the holding surface 60). In other words, the lens barrel 53 has a tapered inner peripheral surface 58. The state in which the inner diameter of the lens barrel 53 increases as the lens barrel 53 progresses from one opening 56 to the other opening 57 is maintained.

[0075] Then, after the first lens 51 abuts the positioning portion 61 and is held by the holding surface 60 at a predetermined position, the ring-shaped spacer 63 is inserted from one opening 56 into the tapered inner peripheral surface. The holding surface 60 is inserted through 58, and the lower surface 63B is brought into contact with the convex lens surface 51B of the first lens 51. The upper surface 63A of the spacer 63 forms a second contact surface that determines the position of the second lens 52 in the optical axis direction, and also serves to define the distance between the first lens 51 and the second lens 52. Fulfill

Next, the second lens 52 is press-fitted from one opening 56 through the tapered inner peripheral surface 58 until it comes into contact with the upper surface 63A of the spacer 63, and the outer peripheral surface 52A is held by the holding surface 60. Here, the outer diameter of the second lens 52 is almost the same as or slightly larger than the inner diameter of the lens barrel 53 at the lens holding position (holding surface 60), and is a large lens that plastically deforms the inside of the lens barrel 53. Does not have a diameter.

As described above, the second lens 52 is also held in the lens barrel 53 in the same manner as the first lens 51. In the third embodiment, both the first lens 51 and the second lens 52 can be held with reference to the inner diameter of the lens barrel 53, and there is no indeterminate cause of tilt due to shaving of the lens barrel 53. It becomes possible to assemble so as to determine the distance between them with extremely high accuracy.

In the third embodiment, as in the second embodiment, the positioning portion 61 for positioning the first lens 51 may be formed by a member separate from the lens barrel 53.

[0079] (Fourth embodiment)

Next, a fourth embodiment of the lens holding device according to the present invention will be described with reference to FIG. FIG. 6 is a cross-sectional view of a lens barrel 72 included in the fourth embodiment. Here, the cross-sectional view is a cross-sectional view taken along a plane orthogonal to the direction of the optical wheel.

This fourth embodiment corresponds to a modification of the first embodiment, and differs from the first embodiment only in that a lens barrel 72 is provided instead of the lens barrel 12. This lens barrel 72 differs from the lens barrel 12 of the first embodiment only in that it has substantially fan-shaped concave portions 74 at three locations in the circumferential direction on the inner peripheral surface 72A. The substantially fan-shaped recess 74 extends by a predetermined dimension in the optical axis direction. Na Needless to say, the number of recesses 74 is not limited to three, and may be one or four or more. In addition, the shape of the recess 74 is not limited to a fan shape, and may be a polygonal shape or a semicircular shape.

[0081] The inner peripheral surface 73 of the region where the concave portion 74 of the lens barrel 72 is not formed serves as a holding surface. The inner peripheral surface 73 forming the holding surface holds the outer peripheral surface 11A of the lens 11 by pressing the outer peripheral surface 11A of the circular lens 11 radially inward with an elastic restoring force. Here, it goes without saying that the lens barrel 72 has the same positioning portion as the lens barrel 12 and its contact surface, and the lens 11 is positioned in the optical axis direction by this contact surface.

According to this embodiment, the shape of the inner peripheral surface 73 forming the holding surface and the shape of the outer peripheral surface 11A of the lens 11 match each other, and even if there is a difference, the recess 74 This makes it easier to absorb the difference in shape between the holding surface 73 and the lens outer peripheral surface 11A. For example, even if the lens outer peripheral surface 11A is not circular but polygonal (for example, quadrangular), the lens outer peripheral surface is held by the holding surface 73 and the shape that fits in the recess 74 can be within the lens barrel 72. It can be held.

Further, in the fourth embodiment, when the lens barrel 72 and the lens 11 are bonded with an adhesive, the concave portion 74 can be used as a liquid reservoir for the adhesive, and the adhesive can be easily applied. There is an advantage. Further, in the cross section shown in FIG. 6, the three inner peripheral surfaces (holding surfaces) 73 in the circumferential direction of the lens barrel 72 are circular if the outer peripheral surface 11A of the lens 11 abuts. It does not have to be, and may have a polygonal shape such as a quadrangle.

Note that the structure of the lens barrel 72 having a recess on the inner wall as in the fourth embodiment can also be adopted in the lens barrels of the second to third embodiments. In the first to fourth embodiments as described above, the lens can be positioned with extremely high precision using the contact surface of the positioning portion, and the shape of the contact surface is changed. In addition to lens positioning, the positioning unit can have a role as a diaphragm used in a lens optical system such as a camera. In addition, the lens holding device having the same effect as described above can be configured even when the cross-sectional shape of the lens and the lens barrel in the present invention is not particularly limited to an ellipse, a rectangle, or other special shapes.

[0085] (Fifth embodiment)

Next, FIG. 8 shows a longitudinal section of a fifth embodiment of the lens holding device of the present invention. This first The lens holding device according to the fifth embodiment corresponds to a modification of the above-described third embodiment. The fifth embodiment is different from the third embodiment described above in that three or more spheres 83 containing a magnetic material are provided instead of the ring-shaped spacer 63 of FIG. Therefore, in the fifth embodiment, the same parts as those in the third embodiment in FIG. 5 are denoted by the same reference numerals, and different parts from the third embodiment will be mainly described.

[0086] In the fifth embodiment, a magnetic material is included between the first lens 51 and the second lens 52.

Three or more spheres 83 were arranged. The spherical body 83 is in contact with the flat lens surface 52 C of the second lens 52, the convex lens surface 51 B of the first lens 51, and the holding surface 60 that forms the inner wall of the lens barrel 53. These three or more spheres 83 define the distance between the two lenses 51 and 52 adjacent in the direction of the optical wheel.

Here, the three or more spheres 83 forming a spacer determine the distance between the first lens 51 and the second lens 52 and the position of the second lens 82. Therefore, it is desirable that the sphere 83 is a highly accurate processed product. The material of the sphere 83 should satisfy the required accuracy and include a magnetic material.

In the lens holding device according to the fifth embodiment, first, as described in the first embodiment, the first lens 51 is moved from one opening 56 through the tapered inner peripheral surface 58 to the convex lens surface 51C. Is press-fitted until it comes into contact with the contact surface 61A of the positioning portion 61, and the outer peripheral surface 51A is held by the holding surface 60. Here, the lens barrel 53 has moderate elasticity, and plastic deformation does not occur even when the first lens 51 is press-fitted. The inner diameter of the lens barrel 53 is the narrowest in the opening 56 between the one opening 56 where the lens is press-fitted and the position where the lens is fixed (that is, the holding surface 60). In other words, the lens barrel 53 has the tapered inner peripheral surface 58, so that the inner diameter of the lens barrel 53 increases as the lens barrel 53 progresses from one opening 56 to the other opening 57. Is maintained.

Then, after the first lens 51 comes into contact with the positioning portion 61 and is held by the holding surface 60 at a predetermined position, three or more spheres 83 are inserted through one opening 86. Here, the ring-shaped magnet 88 is arranged so as to surround the outer peripheral surface of the lens barrel 53, and the ring-shaped magnet 88 is positioned at a position in the optical axis direction of the three or more spheres 83. Thus, the magnetic attraction force of the ring-shaped magnet 88 is used to replace the three or more spheres 83 with the convex lens of the first lens 51. The surface 51B is brought into contact with the holding surface 60 forming the inner wall of the lens barrel 53. The three or more spheres 83 serve to define the distance between the first lens 51 and the second lens 52.

[0090] Next, the second lens 52 is press-fitted from one opening 56 through the tapered inner peripheral surface 58 until it comes into contact with the sphere 83, and the outer peripheral surface 52A is held by the holding surface 60 that forms the inner wall of the lens barrel 53. Let Here, the outer diameter of the second lens 52 is approximately the same as or slightly larger than the inner diameter of the lens barrel 53 at the lens holding position (holding surface 60), and a large lens diameter that causes plastic deformation in the lens barrel 53. It does not have.

As described above, the second lens 52 is also held in the lens barrel 53 in the same manner as the first lens 51. In the third embodiment, both the first lens 51 and the second lens 52 can be held on the basis of the inner diameter of the lens barrel 53, and there is no uncertain cause of tilt due to shaving of the lens barrel 53 or the like. In addition, the sphere 83 that defines the lens interval is fixed in position by the magnetic attraction force from the outside of the lens barrel 53, so it is possible to assemble so that the distance between the lenses can be determined with extremely high accuracy. become.

In the fifth embodiment, the three or more spheres 83 are arranged between the positioning portion 61 and the first lens 51, and the three or more spheres 83 are attached to the contact surface 61A. The lens surface 51C and the inner peripheral surface of the lens barrel 53 may be brought into contact with each other. In this case, the three or more spheres 83 are spacers that define the distance between the contact surface 61A of the positioning portion 61 and the first lens 51 with high accuracy. Further, the three or more spheres 83 may be disposed between the first lens 51 and the second lens 52 and between the positioning unit 61 and the first lens 51. Of course. In the fifth embodiment, the first and second lenses 51 and 52 are provided. However, three or more lenses press-fitted into the lens barrel may be provided. In this case, three or more spheres containing a magnetic material are arranged between the lenses, and the spheres are brought into contact with the facing lens surface and the inner peripheral surface of the lens barrel. In addition, the lens holding device having the same effect as described above can be configured even if the cross-sectional shape of the lens and the lens barrel in the present invention is an ellipse, a rectangle, and other special shapes that are not particularly limited.

Claims

The scope of the claims

[1] A lens barrel (12, 42, 53) having an opening (14, 43, 56) on at least one side in the optical axis direction;

Comprising at least one lens (11, 41, 51, 52) fixed by being press-fitted into the lens barrel from the one opening;

The lens barrel is

A tapered inner peripheral surface (16, 46, 58) having an inner diameter increasing from the one opening to the other in the optical axis direction;

A holding surface (17, 47, 60, 73) that extends from the inner circumferential surface of the taper to the other side in the optical axis direction and that holds the lens by contacting the outer circumferential surface of the lens from the outside in the radial direction. ) And

Further, the lens extends inward in the radial direction intersecting the holding surface and contacts the other surface (11C, 41C, 51C) in the optical axis direction of the lens to position the lens in the optical axis direction. A lens holding device comprising a positioning portion (18, 45, 61) including a contact surface (18A, 45A, 61A).

[2] The lens holding device according to claim 1! /,

A plurality of lenses (51, 52) that are press-fitted and fixed in the lens barrel (53), and further disposed between the two lenses adjacent in the optical axis direction, and the distance between the two lenses A lens holding device comprising a spacer (63) for defining

[3] The lens holding device according to claim 1! /,

The lens is characterized in that the lens is pressed into the tapered inner peripheral surface from one opening in the optical axis direction of the lens barrel, and is held in the lens barrel by elastic deformation of the holding surface. Holding device.

[4] In the lens holding device according to claim 2,

The lens holding device, wherein the spacer is integral with the lens barrel.

[5] The lens holding device according to claim 2,

The lens holding device, wherein the spacer (63) is separate from the lens barrel (12, 42, 53).

[6] In the lens holding device according to claim 1,! / The lens holding device, wherein the positioning portion (18, 61) is integral with the lens barrel (12, 53).

[7] In the lens holding device according to claim 1,! /

The lens holding device, wherein the positioning portion (45) is separate from the lens barrel (42) and is attached to the lens barrel! /.

[8] In the lens holding device according to claim 1,! /

The lens holding device, wherein an inner peripheral surface of one opening in the optical axis direction has a chamfered portion (36).

[9] In the lens holding device according to claim 1,! /

The lens holding device, wherein the lens is made of glass or resin.

[10] In the lens holding device according to claim 1,! /

The lens barrel has an inner peripheral surface showing a substantially circular shape in a cross section by a surface orthogonal to the optical axis, and the lens has a cross section in which the cross sectional shape by a surface orthogonal to the optical axis is substantially circular. A lens holding device.

[11] In the lens holding device according to claim 1,! /

The lens barrel has an inner peripheral surface showing a substantially elliptical shape in a cross section by a plane orthogonal to the optical axis,

The lens holding device according to claim 1, wherein the lens has a cross section in which a cross section taken along a plane orthogonal to the optical axis is substantially elliptical.

[12] In the lens holding device according to claim 1,! /

The lens barrel has an inner peripheral surface showing a substantially square shape in a cross section by a surface orthogonal to the optical axis,

The lens holding device according to claim 1, wherein the lens has a cross-section in which a cross-sectional shape by a plane orthogonal to the optical axis is a substantially square shape.

[13] The lens holding device according to claim 10,

The outer diameter of the lens (11) is Dl (mm), the inner diameter of one opening (14) in the optical axis direction of the lens barrel into which the lens (11) is press-fitted is D2 (mm), and the lens ( 11) does not hold When the inner diameter of the holding surface (17) of the lens barrel (12) in the state is D3 (mm),

0.990D1 <D2 0.995D3… (1)

0.995DK D2 <D1 (2)

A lens holding device characterized by satisfying the above expressions (1) and (2).

[14] In the lens holding device according to claim 1,! /

The holding surface (73) of the lens barrel (72) has at least one recess (74) that is recessed outward in the radial direction and that extends by a predetermined dimension in the optical axis direction and the circumferential direction. A lens holding device.

[15] In the lens holding device according to claim 1,! /,

The lens holding device, wherein the lens has a chamfered edge.

[16] In the lens holding device according to claim 1,! /

At least two lenses (51, 52) press-fitted into the lens barrel (53);

Two lens surfaces (51B, 52C) and the lens barrel of the two lenses (51, 52) facing each other and disposed between the two lenses (51, 52) adjacent in the optical axis direction Three or more spheres (83) abutting on the inner peripheral surface (58) of (53),

The lens holding device, wherein the sphere (83) includes a magnetic material.

[17] In the lens holding device according to claim 1,! /

At least two lenses press-fitted into the lens barrel;

The lens is disposed between a contact surface of the positioning portion and a lens adjacent to the positioning portion in the optical axis direction, and the contact surface, the lens surface of the lens facing the contact surface, and the Three or more spheres that contact the inner peripheral surface of the lens barrel,

The lens holding device, wherein the sphere includes a magnetic material.