JPH07140364A - Method for fixing lens and lens device - Google Patents

Abstract

PURPOSE:To fix a lens to a holding member with high productivity, with sufficient strength, and with high accuracy and to miniaturize the holding member by giving ultrasonic vibration and fixing the lens to the holding member. CONSTITUTION:A positioning part 1a is provided on a lens barrel 1 as the holding member for holding the lens, and a chamfered part 2a for preventing a crack is provided on a first lens 2. The ultrasonic vibration in a direction around an optical axis being a direction (i) is given to the lens 2, so that the inside wall of the lens barrel 1 is softened by being heated by frictional heat with the external periphery of the lens 2. Furthermore, force in a direction A is added to the lens 2, so that the lens 2 is pused and fixed to be embeded in the lens barrel 1. The force to push the lens 2 into the lens barrel 1 is set to be specified force, so that an accurate position can be easily obtained in the case the lens 2 abuts on the positioning part 1a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing method and a lens device for fixing a lens to a holding member.

[0002]

2. Description of the Related Art Conventionally, there are the following means for fixing and holding a lens in a lens barrel.

Lenses L1 to L3 are provided in a lens barrel B1 having a fixing ring 20 having an external thread portion 20a on its outer periphery as shown in FIG. A fixed ring system in which the fixed ring 20 and the lens barrel B1 are fixedly held by meshing with each other.

Further, a C ring 22 as shown in FIG.
In the lens barrel B2 in which the groove 23 into which the C ring 22 is inserted is provided inside the lens barrel B2, the lenses L4 and L5 are the C ring 22.
The C-ring system in which is inserted into the groove 23 to be fixedly held.

On the other hand, in the plastic lens barrel B3 as shown in FIG. 6, the lens barrel end portion 24 is heated and deformed after the lens is mounted, and the lenses L6 to L8 are fixed and held in the lens barrel B3.

Further, when the heating deformation method as shown in FIG. 7 is used, a spacer 26 is provided between the lenses L10 and L11.
A spacer method is also used in which the lenses L9 to L11 are fixedly held by the lens barrel B4 by sandwiching the lens.

[0007]

However, in the fixing ring system described above, since the female screw portion 21 is provided inside the lens barrel B1, in the lens barrel made of plastic, the lenses L1 to L are used.
It is not possible to obtain sufficient strength for fixing and holding No. 3, the manufacturing process becomes complicated, and the productivity is significantly reduced.

Further, in the C-ring system, the work for mounting the C-ring 22 is unstable, and the adjustment after assembling becomes difficult. Further, the outer diameter of the lens barrel B2 is increased because the groove 23 into which the C ring 22 is inserted is provided inside the lens barrel B2, and the lenses L4 and L5 are used to shield the peripheral portions of the lenses L4 and L5 by the C ring 22. Will reduce the effective diameter.

On the other hand, in the heat deformation method, the lens barrel end portion 24 deformed when the lens barrel end portion 24 is deformed by heating has the lenses L6 to L.
In some cases, sufficient strength for holding and holding the lenses L6 to L8 cannot be obtained because the volume that affects the effective diameter of 8 or deforms is insufficient. Further, as shown in FIG. 6, since the space 25 in which the heating tool is inserted must be provided inside the lens barrel, the lens barrel B3 becomes large.

In the spacer method, the outer dimensions and position of the spacer 26 determine the positions of the lenses L10 and L11. Therefore, the dimensional accuracy and the position accuracy of the spacer 26 are required, so that the manufacturing process of the spacer 26 and the lens barrel B are performed.
The assembly process of No. 4 becomes complicated and the productivity is remarkably reduced.

In view of the above problems, the present invention provides a lens fixing method and a lens device which are highly productive and have sufficient strength, and which make it possible to downsize the holding member.

[0012]

According to the present invention, a lens is fixed to a holding member with high productivity, sufficient strength and high accuracy by fixing the lens to the holding member by applying ultrasonic vibration. In addition, the holding member can be downsized.

Further, according to the present invention, by fixing the lens to the holding member by applying ultrasonic vibration in the direction around the optical axis of the lens, the lens can be fixed at a position in the optical axis direction with high accuracy.

Further, according to the present invention, the lens is ultrasonically welded to the holding member in which the area of the lens mounting portion of the holding member is changed according to the outer diameter of the lens, and the same ultrasonic vibration is applied to a plurality of lenses having different outer diameters. Even if it is welded, it can be fixed to the holding member.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1A shows a lens barrel as a lens device embodying the present invention, and FIG.
It is a lens barrel viewed from the direction A in (a). Figure 1 (a)
In the figure, 1 is a lens barrel as a holding member for holding the lens, and a positioning portion 1a is provided. Reference numeral 2 is a first lens fixed to the lens barrel 1 by ultrasonic welding, and has a chamfered portion 2a for preventing cracking. A second lens 3 is ultrasonically welded to the lens barrel 1 like the first lens. A third lens 4 is ultrasonically welded to the lens barrel 1 like the first lens and the second lens. Reference numeral 5 denotes a fourth lens, which is fixed to the lens barrel 1 by thermal deformation of a heating deformation portion 6 provided at the end of the lens barrel 1.

Ultrasonic welding in the lens barrel shown in FIGS. 1A and 1B will be described. The first lens 2 has a superposition in the direction around the optical axis, which is the i direction shown in FIG. 1B. By applying the sound wave vibration, the inner wall of the lens barrel 1 is heated by the frictional heat with the outer circumference of the first lens 2 to be softened. Then, the first lens 2 is fixed so as to be embedded in the lens barrel 1 by applying a force in the direction A of FIG.

Further, if the force for pushing the first lens 2 into the lens barrel 1 is set to a predetermined force, the accurate position can be easily obtained by hitting the positioning portion 1a.

FIG. 2 is a diagram showing a second embodiment.
2A is a cross-sectional view of a lens barrel in which the present invention is implemented, FIG.
2B is a view of the lens barrel viewed from the direction B in FIG.

In FIGS. 2A and 2B, 1
Reference numeral 1 denotes a lens barrel which is a holding member and has a first first lens mounting portion 11a and a second lens mounting portion 11b.
12 is a first lens mounting portion 11a formed by ultrasonic welding.
The first lens 13 is fixed to the second lens 13 and the second lens 13 is ultrasonically welded to the second lens mounting portion 11b.
5 is a third lens fixed by heat deformation, 16
Is a heat-deformation part that fixes the third lens.

In fixing a lens by ultrasonic welding as described above, when fixing a lens having a large outer diameter as shown in FIG. 2 to the lens barrel 11 which is a lens holding member, the output of the ultrasonic welding device is constant. Even if it is set to, in order to properly fix the lens regardless of the outer diameter of the lens, the area of the first lens mounting portion 11a and the second lens mounting portion 11b of the lens barrel 11 is equal to the outer diameter of the lens to be mounted. It was set to be inversely proportional.

That is, even if the torque output of the ultrasonic welding device applied to the center of the lens is constant, the area of the lens mounting portion that contacts the outer periphery of the lens is set small when the outer diameter of the lens is large. On the other hand, when the outer diameter of the lens is small, the area of the lens mounting portion is set large.

Further, even if the number of lens mounting portions is changed according to the outer diameter of the lens as shown in FIG. 3, the same effect can be obtained.

On the other hand, even if the lens is ultrasonically welded by applying ultrasonic vibration in the circumferential direction of the lens barrel 1 of FIG. 1A, the same effect can be obtained.

[0024]

As described above, in the lens fixing method of fixing the lens to the holding member for holding the lens, the lens is moved by applying ultrasonic vibration to at least one of the lens and the holding member. By using the lens fixing method characterized in that the lens is fixed to the holding member, the lens can be fixed to the holding member with high productivity and sufficient fixing strength and high accuracy, and at the same time, the holding member can be greatly expanded. The lens device manufactured by the fixing method can be downsized, and the holding member is small, and has sufficient lens fixing strength and high accuracy.

In the lens fixing method of fixing the lens to a holding member for holding the lens, ultrasonic vibration is applied to the lens or at least one of the holding members in the direction around the optical axis. By using the lens fixing method characterized in that the lens is fixed to the holding member, in addition to high productivity and sufficient strength, particularly the position in the optical axis direction can be determined with high accuracy, and the holding member can be fixed. Can be significantly downsized.

Further, by applying ultrasonic vibration in a direction around the optical axis to the lens, the lens is fixed to a holding member in which the area of the lens mounting portion is changed according to the outer diameter of the lens. Since it is possible to weld a plurality of different lenses with the same ultrasonic vibration, it is possible to improve productivity.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a second embodiment of the present invention.

FIG. 3 is a diagram for explaining another lens barrel according to the second embodiment of the present invention.

FIG. 4 is a diagram illustrating a lens fixing method using a fixing ring.

FIG. 5 is a diagram illustrating a lens fixing method using a C ring.

FIG. 6 is a diagram illustrating a lens fixing method by heat deformation.

FIG. 7 is a diagram illustrating a lens fixing method by heat deformation using a spacer.

[Explanation of symbols]

 1, 11 Lens barrel (holding member) 1a Positioning portion 2 Ultrasonic welded first lens 2a Crack preventing chamfer 3 Ultrasonic welded second lens 4 Ultrasonic welded third lens 5 Fourth lens 6 fixed by heat deformation 6 Heat deformation portion 11a First lens attachment portion 11b Second lens attachment portion

Claims (6)

[Claims] 1. A lens fixing method for fixing a lens to a holding member for holding the lens, wherein the lens is fixed to the holding member by applying ultrasonic vibration to at least one of the lens and the holding member. A lens fixing method, which is characterized in that 2. A lens device in which a lens is fixed to a holding member by ultrasonic welding. 3. A lens fixing method for fixing a lens to a holding member for holding the lens, wherein ultrasonic vibration is applied to at least one of the lens and the holding member in a direction around the optical axis of the lens. A lens fixing method comprising fixing a lens to the holding member. 4. A fixing method for fixing a lens to a holding member for holding the lens, wherein the lens is fixed to the holding member by applying ultrasonic vibration in a direction around the optical axis to the lens. The characteristic lens fixing method. 5. A lens device having a lens and a holding member for holding the lens, wherein the lens is ultrasonically changed to a holding member in which an area of a lens mounting portion of the holding member is changed according to an outer diameter of the lens. A lens device characterized by being fixed by welding. 6. The lens device according to claim 5, wherein the area of the lens mounting portion of the holding member is made inversely proportional to the outer diameter of the lens.