JPH1096842A - Lens device and method for assembling lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To guarantee the high positional accuracy of a lens with a simple manufacturing process in a lens device deforming the part of a lens holding member to hold the lens. SOLUTION: Thermoplastic adhesive 4 is previously applied on the recessed part 2C of the inside peripheral surface of the thermally deformed part 2B of the cylindrical lens holding member 2. After the lens 1 is inserted in the lens receiving part 2S of the member 2, the part 2B is pressurized while being heated by a jig 5, so that the leading end part of the member 2B is bent to press the lens 1, and also the adhesive 4 is melt by utilizing heat for heating the part 2B so as to stick the lens 1 to the member 2. The lens 1 is stuck simultaneously with calking operation, so that the position of the lens 1 does not shifted even though the lens 1 receives disturbance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a lens device and a lens assembling method.

[0002]

2. Description of the Related Art Conventionally, in a lens device in which a lens group consisting of one or more lenses (hereinafter, simply referred to as a lens) is held by a cylindrical lens holding member, a method of holding the lens by the lens holding member. As a known method, a method of bonding a lens to a lens holding member using an adhesive, and a method of deforming a part of the lens holding member by heat or pressure and caulking to hold the lens on the lens holding member are known. .

In a conventional method of holding a lens on a lens holding member with an adhesive, for example, as shown in a sectional view of FIG. 1, a lens 1x is placed in a lens receiving portion 2y at a predetermined position in a cylinder of a cylindrical lens holding member 2x. By inserting and injecting an adhesive between the lens 1x and the lens holding member 2x, a strong adhesive force is given between the lens 1x and the lens holding member 2x, and the lens 1x is held by the lens holding member 2x.

However, according to the method using the adhesive, when the lens 1x is thin, the outer peripheral surface of the lens to which the adhesive is applied becomes small. . Furthermore, in the method using an adhesive, the productivity is poor because it is necessary to control the amount of the adhesive to be injected when manufacturing the lens device.

On the other hand, in a conventional method of holding a lens on a lens holding member by swaging, as shown in a sectional view of FIG. 2, for example, a lens receiving portion 2y of a lens holding member 2x.
The lens 1x is inserted into the lens 1x by deforming the tip of the deformed portion 2Bx of the lens holding member 2x provided adjacent to the lens receiving portion 2y so as to fall down to the lens 1x side and fitting the lens 1x. Is held by the lens holding member 2x. This method is suitable for making the lens device compact. Further, since the management of the deformation of the deformed portion 2Bx of the lens holding member 2x is easier than the management of the amount of the adhesive, this method is also excellent in productivity.

However, unlike the method using an adhesive, the method using caulking merely deforms the lens in the direction of the optical axis because a deformed part of the lens holding member merely presses the lens in the optical axis direction. It may shift in the radial direction, and it is difficult to guarantee high positional accuracy of the lens. Therefore, the method of holding a lens by deforming a part of the lens holding member satisfies the high positional accuracy required for each lens as the number of lenses decreases due to the recent compactness of the lens device. That is difficult.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and relates to a lens device for holding a lens by deforming a part of a lens holding member by a simple manufacturing process. It is an object of the present invention to provide a lens device and a lens assembling method that can guarantee a high positional accuracy of a lens.

[0008]

In order to solve the above technical problems, the present invention provides a lens device and a lens assembling method having the following configurations.

In the lens device, the lens is held at a predetermined position in the cylinder of the cylindrical lens holding member by being pressed in the optical axis direction by the heat deforming portion of the lens holding member. A thermoplastic adhesive is interposed at a fitting portion between the thermally deformed portion of the lens holding member and the lens, and the thermoplastic adhesive bonds the thermally deformed portion of the lens holding member to the lens. . The shape of the lens holding member may be any shape as long as it covers the periphery of the space through which the light beam passes, and includes a ring shape.

A lens device for holding a lens as described above is manufactured by assembling the lens as follows.

According to the lens assembling method, basically, the lens is arranged at a predetermined position in the cylinder of the cylindrical lens holding member, and then the heat is provided around the predetermined position in the cylinder of the lens holding member. The deformable portion is heated, and the heat deformable portion deforms the heat deformable portion so as to press the lens in the optical axis direction, thereby holding the lens at a predetermined position in the cylinder of the lens holding member. Then, in the lens assembling method, a thermoplastic adhesive is previously provided on an inner peripheral surface of the heat deformable portion of the lens holding member. Heating the heat deformable portion of the lens holding member, heat deforming the heat deformable portion, pressing the lens in the optical axis direction, and utilizing the heat transmitted to the heat deformable portion, the thermoplastic bonding As the agent is melted and cooled, the thermally deformed portion of the lens holding member and the lens are bonded by the thermoplastic adhesive. In addition, the above-mentioned heat deformation part is not only a part deformed by heating, but also a part heated but not deformed.
(For example, a portion indicated by reference numeral 2K in FIG. 4).

The lens device having the above-described structure manufactured as described above is provided with a thermoplastic adhesive on the inner peripheral surface of the thermally deformed portion of the lens holding member. At the same time as the step of heating and deforming the deformed part,
The step of heating and melting the thermoplastic adhesive can be performed using heat for heating the thermally deformed portion. Then, after cooling, the lens can be pressed in the optical axis direction by the thermally deformed portion of the lens holding member, and the lens can be bonded to the lens holding member with the cured thermoplastic adhesive. That is, the lens can be held by the lens holding member by performing the bonding simultaneously with the heat staking. The lens is fixed to the lens holding member not only by caulking but also by bonding, so that the lens does not shift with respect to the lens holding member even when subjected to disturbance. Therefore, the positional accuracy of the lens can be improved.

Therefore, with the lens device and the lens assembling method having the above-described configurations, it is possible to guarantee a high positional accuracy of the lens in a simple manufacturing process for the lens device that holds the lens by partially deforming the lens holding member.

[0014] Preferably, the thermoplastic adhesive is provided at least on an inner peripheral surface of the heat deformable portion of the lens holding member facing the outer peripheral surface of the lens.

That is, the thermoplastic adhesive is provided at least in the thermal deformation portion of the lens holding member which faces the outer peripheral surface of the lens when the lens is disposed at a predetermined position in the cylinder of the lens holding member. On the inner surface of the
It is provided in advance.

In the above configuration, the thermoplastic adhesive bonds the outer peripheral surface of the lens to the inner peripheral surface of the thermally deformed portion of the lens holding member. A uniform clearance is formed between the outer peripheral surface of the lens and the inner peripheral surface of the heat deforming portion of the lens holding member, and the outer peripheral surface of the lens is formed on the inner peripheral surface of the heat deforming portion of the lens holding member. Can be bonded uniformly and strongly. Further, since the lens is bonded to the outer peripheral surface of the lens which is the outermost in the radial direction, the rotation is efficiently prevented.

Therefore, the lens can be securely and efficiently bonded to the lens holding member.

In the above configuration, the thermoplastic adhesive can be provided in advance on the inner peripheral surface of the thermally deformed portion of the lens holding member in the following two modes.

In the first aspect, the thermoplastic adhesive is previously applied to the inner peripheral surface of the thermally deformed portion of the lens holding member.

In the above configuration, an appropriate amount of thermoplastic adhesive having desired characteristics can be easily provided at a desired position on the inner peripheral surface of the heat deformable portion of the lens holding member.

In the second mode, a ring-shaped thermoplastic adhesive sheet is fitted in advance on the inner peripheral surface of the heat deformable portion of the lens holding member.

In the above configuration, it is not necessary to apply a thermoplastic adhesive to the lens holding member. Constant shape
When a thermoplastic adhesive sheet having a dimension is used, the amount of the thermoplastic adhesive becomes constant, so that the amount of the thermoplastic adhesive can be easily controlled.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a lens device and a lens holding method according to each embodiment of the present invention shown in FIGS. 3 to 7 will be described in detail.

First, a first embodiment of the present invention will be described with reference to FIGS.

The lens device of the present embodiment has a lens 1 and a lens holding member 2 as shown in a sectional view of a main part of FIG. The lens holding member 2 has a lens receiving portion 2S on the inner peripheral surface at the end of the cylindrical tube wall 2A, and the lens 1 is positioned and stored in the axial direction and the radial direction. The lens holding member 2 has a thermally deformed portion 2B that protrudes in the axial direction at the end of the lens holding member 2 and around the lens receiving portion 2S. A concave portion 2C is formed on the inner peripheral surface of the thermally deformed portion 2B. A part of the concave portion 2C corresponds to the outer peripheral surface 1B of the lens 1 arranged in the lens receiving portion 2S.
To be opposed. As shown in the perspective view of FIG. 6, the thermoplastic adhesive 4 is applied to the concave portion of the lens holding member 2 in an appropriate amount 2C by using a brush 6.

In this lens device, as follows:
The lens 1 is incorporated and held in the lens holding member 2.

That is, first, as shown in FIG. 3, the lens 1 is inserted into the lens receiving portion 2S of the lens holding member 2, and the lens 1 is positioned in the optical axis direction and the radial direction.

Next, as shown in the sectional view of the main part of FIG. 4, a heat deformation jig 5 heated to about 200 ° C. is brought into contact with the heat deformation part 2B of the lens holding member 2, and By pressing while heating, the tip portion of the thermal deformation portion 2B is deformed so as to fall on the lens surface 1A of the lens 1,
The lens 1 is pressed in the optical axis direction at the tip of the thermal deformation portion 2B. At this time, at the same time, the thermal deformation portion 2B of the lens holding member 2
The thermoplastic adhesive 4 in the concave portion 2C is heated and melted by the heat transmitted to the heat deforming portion 2B, and is formed between the lens surface 1A and the outer peripheral surface 1B of the lens 1 and the inner peripheral surface of the deformed heat deforming portion 2B. Placed between.

Next, as shown in the sectional view of the main part of FIG. 5, the heat deforming jig 5 is removed from the lens holding member 2 and cooled, so that the heat of the lens holding member 2 is maintained while the lens 1 is held down. While curing the deformed portion 2B, the lens 1
The thermoplastic adhesive 4 between the lens and the thermally deformable portion 2B of the lens holding member 2 is hardened to exert an adhesive force, and the lens 1 is bonded to the thermally deformable portion 2B of the lens holding member 2.

The lens 1 incorporated in the lens device as described above is not only prevented from moving in the optical axis direction by the heat deforming portion 2B of the lens holding member 2, but also is made of a lens holding member made of a thermoplastic adhesive 4. The rotation and radial movement are prevented by the adhesion with the second member. Therefore, lens 1
Does not move even when subjected to a disturbance, so that high positional accuracy can be guaranteed. Further, since the space 3 for inserting the adhesive and the member for injecting the adhesive is unnecessary, it is easy to save space near the end of the lens 1. Furthermore, since the heat deformation portion 2B of the lens holding member 2 is thermally deformed and bonded at the same time, the manufacturing process can be simplified and the productivity can be improved. A uniform clearance is formed between the outer peripheral surface 1B of the lens 1 and the inner peripheral surface of the thermally deformed portion 2B of the lens holding member 2, and the outermost outer peripheral surface 1B of the lens 1 is It is easy to adhere with a strong adhesive force.

In the first embodiment, the thermoplastic adhesive 4
Is applied to the concave portion 2C on the inner peripheral surface of the lens holding member 2. However, as in the second embodiment described below, a thermoplastic adhesive 4A can be provided independently of the lens holding member 2 independently. It is.

That is, the lens 1 and the lens holding member 2 are constructed in substantially the same manner as in the first embodiment, but as shown in the perspective view of FIG. 7, the thermoplastic adhesive 4A is a ring-shaped sheet. It has a thin cylindrical shape and is provided independently of the lens holding member 2. This thermoplastic adhesive 4
A, instead of the thermoplastic adhesive 4 applied to the concave portion 2C of the thermally deformed portion 2B of the lens holding member 2 in the first embodiment, is fitted to the inner peripheral surface of the concave portion 2C.

In this embodiment, the lens 1 is assembled and fixed to the lens holding member 2 as follows. That is, the lens 1 is moved to the lens receiving portion 2 of the lens holding member 2.
S, a ring-shaped thermoplastic adhesive 4A is arranged on the inserted lens 1, and fitted into the concave portion 2C of the thermally deformed portion 2B of the lens holding member 2. After that, it is the same as the first embodiment, and heats the heat deformable portion 2B of the lens holding member 2 with the heat deforming jig 5 to deform the heat deformable portion 2B and press the lens 1 in the optical axis direction. , Thermoplastic adhesive 4
After A is melted and cooled, the lens 1 is fixed to the lens holding member 2 by caulking and bonding.

The second embodiment has the same effect as the first embodiment, but the concave portion 2C of the lens holding member 2
It is easier to control the amount of the thermoplastic adhesive 4A than in the case where the thermoplastic adhesive 4 is applied to the substrate.

The present invention is not limited to the above embodiment, but can be implemented in various other modes. For example, the thermal deformation portion 2B of the lens holding member 2
May be provided continuously or partially, that is, intermittently. In addition, the heat deforming portion 2B includes the lens holding member 2
May be provided not at the end but at an intermediate portion in the axial direction. Further, the heat deformation portion 2B may extend obliquely with respect to the axial direction, and the heat deformation jig 5 may press the heat deformation portion 2B in a direction perpendicular to the axis, that is, in a radial direction.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part of a conventional lens device that holds a lens with an adhesive.

FIG. 2 is a sectional view of a main part of a lens device that holds a lens by partially deforming a conventional lens holding member.

FIG. 3 is a sectional view of a main part of a lens device according to an embodiment of the present invention before thermal deformation.

4 is a cross-sectional view of a main part of the lens device of FIG. 3 during thermal deformation.

FIG. 5 is a cross-sectional view of a main part of the lens device of FIG. 3 after thermal deformation.

FIG. 6 is a perspective view showing a state where a thermoplastic adhesive is applied to a lens holding member.

FIG. 7 is an exploded perspective view of a lens device according to another embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 lens 1A lens surface 1B outer peripheral surface 2 lens holding member 2A cylindrical wall 2B thermal deformation portion 2C concave portion (inner peripheral surface) 2S lens receiving portion (predetermined position) 4,4A thermoplastic adhesive 5 thermal deformation jig 6 brush

Claims (6)

[Claims] 1. A predetermined position in a cylinder of a cylindrical lens holding member (2).
(2S) a lens device in which the lens (1) is pressed and held in the optical axis direction by a thermally deformed portion (2B) of the lens holding member (2); A thermoplastic adhesive (4, 4) is attached to a fitting portion (2C) between the deformed portion (2B) and the lens (1).
4A), and the thermoplastic adhesive (4, 4A) and the heat-deformed portion (2B) of the lens holding member (2) and the lens
(1) A lens device characterized by bonding. 2. The thermoplastic adhesive (4, 4A) is provided at least in the thermal deformation portion (2B) of the lens holding member (2) facing the outer peripheral surface (1B) of the lens (1). Surrounding surface (2
The lens device according to claim 1, wherein the lens device is provided in part C). 3. A predetermined position in the cylinder of the cylindrical lens holding member (2).
(2S), the lens (1) is disposed, and then the heat deforming portion (2B) provided around the predetermined position (2S) in the cylinder of the lens holding member (2) is heated. (2B) is the lens (1)
A lens assembling method for deforming the thermal deformation portion (2B) so as to press the lens in the optical axis direction, and holding the lens (1) at the predetermined position (2S) in the cylinder of the lens holding member (2). Inner peripheral surface of the heat deformable portion (2B) of the lens holding member (2)
(2C), a thermoplastic adhesive (4, 4A) is provided in advance, and the heat deformable portion (2B) of the lens holding member (2) is heated to thermally deform the heat deformable portion (2B). Let the above lens (1)
In the direction of the optical axis, and utilizing the heat transmitted to the thermally deformed portion (2B), the thermoplastic adhesive (4, 4A).
Is melted, and after cooling, the thermoplastic adhesive (4) and the thermally deformed portion (2B) of the lens holding member (2) and the lens
(1) A method of assembling a lens, characterized by bonding: 4. The heat deformable portion of the lens holding member (2)
(2B) on the inner peripheral surface (2C), the thermoplastic adhesive (4)
4. The lens device according to claim 3, wherein is applied in advance. 5. The thermal deformation portion of the lens holding member (2)
4. The lens assembling method according to claim 3, wherein a ring-shaped thermoplastic adhesive sheet (4A) is previously fitted to the inner peripheral surface (2C) of (2B). 6. The thermoplastic adhesive (4, 4A) is provided at least at a predetermined position in the cylinder of the lens holding member (2).
When the lens (1) is arranged in (2S), the lens
The lens holding member (2) facing the outer peripheral surface (1B) of (1).
The lens device according to claim 3, wherein the lens device is provided in advance on a portion of an inner peripheral surface (2C) of the thermal deformation portion (2B).