JP6349281B2 - Optical device and method for assembling the same - Google Patents

Description

  The present invention relates to an optical device including a lens and a lens holding member, and an assembling method thereof.

  The camera lens and the projector lens are attached to a barrel that holds them. In the lens mounting structure described in Patent Document 1, a cylindrical portion provided with a regular polygonal hole is used in order to suppress deviation of the center of the lens after mounting, and the outer peripheral edge of the lens is the hole. The center of the lens is positioned by the side portion. Further, in the optical element holding device described in Patent Document 2, a lens barrel and a first member whose coefficient of thermal expansion and dimensions are set in advance so as to maintain stable optical performance against temperature change and posture change. The optical element is held by the member of the second member.

JP 2006-133695 A JP 2010-97069 A

  In an optical device provided with a lens and a lens holding member, a difference occurs in the expansion amount of each component with a change in temperature due to a difference in thermal expansion coefficient between components and nonuniformity. As a result, the lens is decentered. In the lens mounting structure described in Patent Document 1, it is considered that a difference in expansion occurs between the lens and the cylindrical portion due to a temperature change, and therefore the eccentricity of the lens cannot be prevented. In addition, in the optical element holding structure described in Patent Document 2, the thermal expansion coefficient and dimensions are set in advance so that the displacement amounts of different parts due to temperature changes coincide with each other, but this setting stabilizes the optical element. Since the first member and the second member are necessary in addition to the lens barrel in order to hold them, the number of parts increases. Moreover, since the structure for engaging the first member or the second member with the lens barrel is necessary, the size of the lens barrel is increased. For this reason, there has been a demand for an optical device that can suppress the decentration of the lens accompanying a temperature change with a simple configuration.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide an optical device and an assembling method thereof that can suppress decentration of a lens accompanying a temperature change with a simple configuration.

An optical device according to an aspect of the present invention is an optical device including a lens and a holding member that holds the lens in a cylindrical cavity, and an outer diameter portion of the lens is provided on an outer periphery of the lens. And a plurality of concave portions formed so that the radial distance of the lens between the holding member and the outer diameter portion is wider than the outer diameter portion, and the concave portion is provided in the cavity. The concave portion and the inner peripheral surface of the holding member are bonded and fixed via an adhesive portion, and the inner peripheral surface of the holding member from the concave portion of the lens in each of the plurality of adhesive portions adjacent in the circumferential direction. The maximum value of the length in the radial direction is equal in all of the plurality of adhesive portions adjacent in the circumferential direction, and the outer diameter portion of the lens provided in the cavity portion and the inner circumference of the holding member A gap is provided between the surface .

An optical device assembling method according to an aspect of the present invention is an optical device assembling method including a lens and a holding member that holds the lens in a cylindrical cavity, and the holding member is a predetermined reference. A holding member fixing step that is installed and fixed at a position; an outer diameter portion of the lens; and a concave portion that is formed so that a radial distance between the lens and the holding member is wider than the outer diameter portion; A lens insertion step of inserting the plurality of lenses formed in the circumferential direction into the cavity of the holding member, and diameters from the plurality of recesses provided on the outer periphery of the lens to the inner peripheral surface of the holding member. Lens position adjustment for adjusting the position of the lens with respect to the holding member so that the directional distances are equal and a gap is provided between the outer diameter portion of the lens and the inner peripheral surface of the holding member Step and Adhesive that supplies the adhesive between the concave portion and the inner peripheral surface of the holding member while fixing the position of the lens with respect to the holding member adjusted in the lens position adjusting step, and bonds the lens and the holding member Steps.

  ADVANTAGE OF THE INVENTION According to this invention, the optical apparatus which can suppress the eccentricity of the lens accompanying a temperature change with a simple structure, and its assembly method can be provided.

It is a perspective view which shows the structure of the optical apparatus of one Embodiment which concerns on this invention. It is the front view which looked at the optical apparatus shown in FIG. 1 from the opening side. It is the III-III sectional view taken on the line shown in FIG. It is a figure which shows typically the process in the assembly method of the optical apparatus of one Embodiment. It is a figure which shows typically the process in the assembly method of the optical apparatus of one Embodiment. It is a figure which shows typically the process in the assembly method of the optical apparatus of one Embodiment. It is the front view of the other example which looked at the optical apparatus from the opening side. It is the front view of the other example which looked at the optical apparatus from the opening side. It is the front view of the other example which looked at the optical apparatus from the opening side. It is the front view of the other example which looked at the optical apparatus from the opening side. It is the front view of the other example which looked at the optical apparatus from the opening side. It is the front view of the other example which looked at the optical apparatus from the opening side. It is the front view of the other example which looked at the optical apparatus from the opening side. It is the III-III sectional view taken on the line shown in FIG. 2 in the optical apparatus of other embodiment. It is a figure explaining arrangement | positioning of the several recessed part provided in a lens.

  Hereinafter, an optical apparatus according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view showing a configuration of an optical apparatus according to an embodiment of the present invention. FIG. 2 is a front view of the optical device shown in FIG. 1 viewed from the opening side. 3 is a cross-sectional view taken along line III-III shown in FIG.

  As shown in FIGS. 1 to 3, the optical device 10 of this embodiment includes a lens 11 and a metal barrel 12 as a holding member that holds the lens 11 in a cylindrical cavity 12 h. On the outer periphery of the lens 11, an outer diameter portion 11a constituting the outer diameter of the lens 11 and a concave portion 11b recessed toward the optical axis side of the lens 11 with respect to the outer diameter portion 11a are formed in the circumferential direction. Three portions 11a and three concave portions 11b are alternately arranged. The outer diameter portion 11a has an arc shape similar to the circumferential shape of the inner peripheral surface 12i of the barrel 12 forming the cavity portion 12h, and its diameter length at room temperature is smaller than the diameter of the cavity portion 12h of the barrel 12 . Moreover, the recessed part 11b is a linear form which connects the both ends of the boundary of the recessed part 11b and the outer diameter part 11a. The recesses 11b are arranged at equal intervals in the circumferential direction around the optical axis of the lens 11.

  The lens 11 is provided in the cavity 12 h of the barrel 12 so that the optical axis of the lens 11 is parallel to the central axis of the cavity 12 h of the barrel 12. Each concave portion 11b of the lens 11 provided in the hollow portion 12h and the inner peripheral surface 12i of the barrel 12 are bonded and fixed via an adhesive portion 13 in which the adhesive is cured. Therefore, in the example shown in FIGS. 1 to 3, the lens 11 is supported at three points in the hollow portion 12 h of the barrel 12.

  In the hollow portion 12h of the barrel 12, as shown in FIG. 2, the maximum value of the length in the radial direction from each concave portion 11b of the lens 11 to the inner peripheral surface 12i of the barrel 12 is equal in all the concave portions 11b. Thus, the lens 11 is positioned. For this reason, the maximum value Lmax in the radial direction from the concave portion 11b of the lens 11 to the inner peripheral surface 12i of the barrel 12 in each of the three adhesive portions 13 adjacent in the circumferential direction is all of the three adhesive portions 13. Are equal. If the error of the maximum value Lmax between the three adhesive portions 13 is less than the allowable eccentricity of the lens 11 (for example, 10 μm), the maximum value Lmax is considered to be equal in all the three adhesive portions 13. .

Further, the adhesive portion 13 is formed so that the cross-sectional area perpendicular to the optical axis of the lens 11 is equal in all three adhesive portions 13 adjacent in the circumferential direction. Note that the cross-sectional area S of the adhesive portion 13 is considered to be equal within a range that does not deviate from a × S. The value a is a value at which the eccentricity of the lens 11 caused by the variation in the cross-sectional area S of the adhesive portion 13 does not exceed the allowable amount. That is, the value a is represented by the following formula (1).
a = (r × α × ΔT) / (r × α × ΔT ± x) (1)
r: Radius of lens 11 α: Linear expansion coefficient of lens 11 ΔT: Difference between normal temperature and upper limit temperature for guaranteeing performance x: Allowable eccentricity of lens 11 (for example, 10 μm)

As the adhesive constituting the adhesive portion 13, one having a Young's modulus after curing lower than the Young's modulus of the lens 11 and the barrel 12 is used. In particular, it may be lower than the Young's modulus of the lens 11, and the lower limit value Emin is expressed by the following equation (2). That is, the lower limit value Emin is a value at which the eccentricity generated by the deformation of the adhesive portion 13 due to the weight of the lens 11 does not exceed an allowable value (for example, 10 μm).
Emin = (L × W) / (2 × S × x) (2)
L: length of the adhesive portion 13 in the radial direction from the optical axis of the lens 11 W: weight of the lens 11 S: cross-sectional area of the adhesive portion 13 x: allowable eccentricity of the lens 11 (for example, 10 μm)

  Next, a method for assembling the optical device according to the present embodiment will be described with reference to FIGS.

  As shown in FIG. 4, first, the barrel 12 is installed and fixed at a predetermined reference position, and then the lens 11 attracted by the vacuum pad 51 is inserted into the hollow portion 12 h of the barrel 12. Next, the position of the lens 11 with respect to the barrel 12 is adjusted so that the radial distances from the three recesses 11 b provided on the outer periphery of the lens 11 to the inner peripheral surface 12 i of the barrel 12 are equal. The adjustment of the position of the lens 11 is performed based on the image of the camera 52 that captures the opening of the barrel 12. Next, as shown in FIG. 5, an adhesive is supplied between the concave portion 11 b of the lens 11 and the inner peripheral surface 12 i of the barrel 12, and the gap between the concave portion 11 b and the inner peripheral surface 12 i due to adhesive force, surface tension, and the like. The adhesive portion 13 is formed by curing the adhesive by irradiating the adhesive 13a adhered to the surface with ultraviolet rays. Finally, as shown in FIG. 6, the suction by the vacuum pad 51 is completed, and the assembly of the optical device is completed.

  As described above, in the present embodiment, the outer periphery of the lens 11 is provided with a plurality of recesses 11b that are recessed closer to the optical axis side of the lens 11 than the outer diameter portion 11a at equal intervals in the circumferential direction. The inner peripheral surface 12i is bonded and fixed via an adhesive portion 13 in which the adhesive is cured. The maximum value Lmax and the cross-sectional area S of the radial length from the concave portion 11b of the lens 11 to the inner peripheral surface 12i of the barrel 12 in each of the plurality of adhesive portions 13 adjacent in the circumferential direction are the plurality of adhesives. It is equal in all of the parts 13. For this reason, even if the size of the lens 11 changes due to a temperature change, the lens 11 does not come into contact with the inner peripheral surface 12i of the barrel 12, so that the lens 11 is not subjected to a force that causes eccentricity. In addition, as the adhesive constituting the adhesive portion 13, an adhesive having a Young's modulus after curing lower than the Young's modulus of the lens 11 is used. For this reason, since the expansion of the lens 11 accompanying the temperature rise is evenly absorbed by the plurality of adhesive portions 13, the eccentricity of the lens 11 is suppressed. As described above, the optical device 10 capable of suppressing the decentration of the lens accompanying the temperature change can be realized with a simple configuration.

  Further, the diameter of the outer diameter portion 11a of the lens 11 formed in an arc shape is smaller than the diameter of the hollow portion 12h of the barrel 12 at room temperature. For this reason, in the state where the lens 11 is provided in the hollow portion 12 h of the barrel 12, a gap is provided between the outer diameter portion 11 a of the lens 11 and the inner peripheral surface 12 i of the barrel 12. For this reason, when the optical device 10 is assembled, the lens 11 adsorbed by the vacuum pad 51 can be easily inserted into the hollow portion 12 h of the barrel 12 and aligned. Even if the lens 11 expands as the temperature rises, the outer diameter portion 11 a does not contact the inner peripheral surface 12 i of the barrel 12.

  In the above description, the concave portion 11b of the lens 11 is formed in a linear shape. However, as shown in FIG. 7, even if the concave portion 11b is formed in a curved shape curved toward the optical axis side of the lens 11, FIG. As shown in FIG. 3, the concave portion 11b may be formed in a concave shape that is recessed toward the optical axis side of the lens 11. In the above description, the outer diameter portion 11a of the lens 11 is formed in an arc shape. However, as shown in FIG. 9, the outer diameter portion 11a may be formed in a linear shape as in the case of the concave portion 11b.

  In the above description, three concave portions 11b are formed on the outer periphery of the lens 11, but four concave portions 11b may be formed on the outer periphery of the lens 11, as shown in FIG. If the lens 11 having four concave portions 11b is used, the evaluation when the lens 11 is inserted into the hollow portion 12h of the barrel 12 for alignment is facilitated.

  In the above description, the adhesive portion 13 is provided between the concave portion 11b of the lens 11 and the inner peripheral surface 12i of the barrel 12. However, as shown in FIG. 11, the lens 11 including the outer diameter portion 11a of the lens 11 is provided. An adhesive portion 13 may be provided between the entire outer periphery and the inner peripheral surface 12 i of the barrel 12. In this case, the expansion of the lens 11 accompanying the temperature rise is more evenly absorbed.

  In the above description, one adhesive portion 13 is provided between each concave portion 11 b of the lens 11 and the inner peripheral surface 12 i of the barrel 12. However, when a plastic lens manufactured by injection molding is used as the lens 11. In particular, as shown in FIG. 12, the adhesive portion 13 may be divided into two portions and provided apart from the single recess portion 11b. In this case, the adhesive portion 13 can be disposed avoiding the gate 11g of the lens 11.

  In the above description, the hollow portion 12h of the barrel 12 is cylindrical. However, as shown in FIG. 13, the inner peripheral surface 12i of the barrel 12 facing the concave portion 11b of the lens 11 is made the same as the shape of the concave portion 11b. good. In this case, the length from the recessed part 11b of one adhesive part 13 to the internal peripheral surface 12i can be made constant.

  In this embodiment, since the hollow portion 12h of the barrel 12 is cylindrical, the lens 11 is held only by the adhesive force of the adhesive portion 13. However, as shown in FIG. A step portion 12r perpendicular to the optical axis of the lens 11 may be provided at 12h. In this case, since the lens 11 inserted from the opening of the barrel 12 is engaged with the stepped portion 12r, an arrangement error of the lens 11 in the optical axis direction can be suppressed.

Further, in the lens 11 of the present embodiment, a plurality of concave portions 11b are arranged at equal intervals in the circumferential direction around the optical axis of the lens 11, and the “equal interval” is 20 degrees from an equal angle. An angle difference is allowed, preferably an angle difference of 10 degrees or less. For example, as shown in FIG. 15, a force F1 is received from the adhesive portion 13 at one location of the lens 11, and a force F2 (| F2 | = | F1 |) equivalent to the force F1 from the adhesive portion 13 at the other location. Receive. At this time, if the force F3 (= F1 + F2) applied between the two places receiving the forces F1 and F2 is an angle θ from a position opposite to the place receiving the force F1 in the lens 11 to a place receiving the force F2, the following equation is obtained. It is represented by (3).
| F3 | = | F1 | {sin ² θ + (1-cos ² θ)} ^1/2 (3)
The above “equal interval” means that a deviation within a range not exceeding the angle θ that satisfies “| F3 | ≦ 1/2 | F1 | (4)” is allowed, and 20 degrees ≧ from Equations (3) and (4) | Θ | ≧ 0.

  As described above, the optical device disclosed in the present specification is an optical device that includes a lens and a holding member that holds the lens in a cylindrical cavity, and the outer periphery of the lens includes: A plurality of outer diameter portions of the lens and recesses formed so that a radial interval of the lens between the holding member and the outer diameter portion is wider than the outer diameter portion are formed in the circumferential direction and provided in the cavity portion. The concave portion of the obtained lens and the inner peripheral surface of the holding member are bonded and fixed via an adhesive portion, and the holding from the concave portion of the lens in each of the plurality of adhesive portions adjacent to the circumferential direction. The maximum value of the radial length to the inner peripheral surface of the member is equal in all of the plurality of adhesive portions adjacent in the circumferential direction.

  Moreover, the said recessed part is the linear form which connects the both ends of the boundary of the said recessed part and the said outer diameter part.

  The concave portion has a curved shape that is curved toward the optical axis side of the lens and connects both ends of the boundary between the concave portion and the outer diameter portion.

  Moreover, the said recessed part is a concave shape which became depressed at the optical axis side of the said lens which connects the both ends of the boundary of the said recessed part and the said outer diameter part.

  The outer diameter portion has an arc shape similar to the circumferential shape of the inner peripheral surface of the holding member.

  The outer diameter portion is linear.

  Moreover, the area of the cross section perpendicular to the optical axis of the lens in each of the plurality of adhesive portions adjacent in the circumferential direction is equal in all of the plurality of adhesive portions adjacent in the circumferential direction.

  The Young's modulus after curing of the adhesive that bonds the lens and the holding member is lower than that of the lens and the holding member.

  The concave portions and the outer diameter portions are alternately arranged in the circumferential direction on the outer periphery of the lens, and the plurality of concave portions are arranged at equal intervals in the circumferential direction around the optical axis of the lens.

  Further, four concave portions are formed on the outer periphery of the recording lens.

  In addition, a gap is provided between the outer diameter portion of the lens provided in the cavity and the inner peripheral surface of the holding member.

  An optical device assembling method disclosed in this specification is an optical device assembling method for holding a lens in a cylindrical cavity of a holding member, and the holding member is installed at a predetermined reference position. A holding member fixing step for fixing the lens, an outer diameter portion of the lens, and a concave portion formed so that a radial distance between the lens and the holding member is wider than the outer diameter portion in the circumferential direction. A lens insertion step of inserting a plurality of the formed lenses into the cavity of the holding member, and radial distances from the plurality of recesses provided on the outer periphery of the lens to the inner peripheral surface of the holding member are equal. A lens position adjusting step for adjusting the position of the lens with respect to the holding member, and the position of the lens with respect to the holding member adjusted in the lens position adjusting step is fixed. Supplying an adhesive between the parts and the inner peripheral surface of the holding member, having a bonding step of bonding the lens and the holding member.

DESCRIPTION OF SYMBOLS 10 Optical apparatus 11 Lens 11a Outer diameter part 11b Recessed part 12 Barrel 12h Cavity part 12i Inner peripheral surface 13 Adhesive part 13a Adhesive

Claims (11)

An optical device comprising a lens and a holding member that holds the lens in a cylindrical cavity,
On the outer periphery of the lens, a plurality of outer diameter portions of the lens and a plurality of concave portions formed so as to widen the radial distance of the lens between the holding member and the outer diameter portion are formed in the circumferential direction. And
The concave portion of the lens provided in the hollow portion and the inner peripheral surface of the holding member are bonded and fixed via an adhesive portion,
The maximum value of the radial length from the concave portion of the lens to the inner peripheral surface of the holding member in each of the plurality of adhesive portions adjacent in the circumferential direction is a plurality of the adhesions adjacent in the circumferential direction. rather than equal in all of the agent part,
An optical device in which a gap is provided between the outer diameter portion of the lens provided in the cavity and the inner peripheral surface of the holding member . The optical device according to claim 1,
The said recessed part is an optical apparatus which is a linear form which connects the both ends of the boundary of the said recessed part and the said outer diameter part. The optical device according to claim 1,
The said recessed part is an optical apparatus which is the curved shape curved to the optical axis side of the said lens which connects the both ends of the boundary of the said recessed part and the said outer diameter part. The optical device according to claim 1,
The said recessed part is an optical apparatus which is a concave shape which dents the optical axis side of the said lens which connects the both ends of the boundary of the said recessed part and the said outer diameter part. The optical device according to any one of claims 1 to 4,
The outer diameter portion is an optical device having an arc shape similar to a circumferential shape of the inner peripheral surface of the holding member. The optical device according to any one of claims 1 to 4,
The outer diameter portion is an optical device having a linear shape. The optical device according to any one of claims 1 to 6,
An optical device in which an area of a cross section perpendicular to the optical axis of the lens in each of the plurality of adhesive portions adjacent in the circumferential direction is equal in all of the plurality of adhesive portions adjacent in the circumferential direction. The optical device according to any one of claims 1 to 7,
An optical device in which a Young's modulus after curing of an adhesive that bonds the lens and the holding member is lower than that of the lens and the holding member. The optical device according to any one of claims 1 to 8,
On the outer periphery of the lens, the concave portion and the outer diameter portion are alternately arranged in the circumferential direction, and a plurality of the concave portions are arranged at equal intervals in the circumferential direction around the optical axis of the lens. . An optical device according to any one of claims 1 to 9,
An optical device, wherein four concave portions are formed on an outer periphery of the lens. An assembly method for an optical device for holding a lens in a cylindrical cavity of a holding member,
A holding member fixing step for installing and holding the holding member at a predetermined reference position;
The lens having the outer diameter portion of the lens and a plurality of concave portions formed so that a radial distance between the lens and the holding member is wider than the outer diameter portion is formed in the circumferential direction. A lens insertion step of inserting into the cavity of the member;
The outer diameter portion of the lens and the inner peripheral surface of the holding member so that the radial distances from the plurality of concave portions provided on the outer periphery of the lens to the inner peripheral surface of the holding member are equal. A lens position adjusting step for adjusting the position of the lens with respect to the holding member so that a gap is provided between
Adhesive that supplies the adhesive between the recess and the inner peripheral surface of the holding member while fixing the position of the lens with respect to the holding member adjusted in the lens position adjusting step, and bonds the lens and the holding member And a method of assembling the optical device.

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