JPS60214318A - Lens holding device - Google Patents

Abstract

PURPOSE:To absorb internal stress due to the contraction in setting of an adhesive and the temperature variation in the use of a lens through deformation, and to maintain a high optical characteristic of the lens by allowing the adhesive sticking on the outer peripheral part of the lens to deform in the gap part formed of the inner peripheral surface of a lens storage part. CONSTITUTION:The lens 8 is stored in the lens storage part 12 provided to a lens frame 9 and positioned in its optical axis direction by abutting on a lens holding stage part 13. The inner diameter of the lens storage part 12 is made properly larger than the outer diameter of the lens 8, which is adhered fixedly to the lens frame 9 with the adhesive 10 applied between the outer peripheral surface 8a and the inner peripheral surface of the lens storage part 12. The adhesive 10 when not set is held in an L-sectioned shape through a fixing jig 11 of annular or split constitution as shown in a left-side cross section. When the fixing jig 11 is removed after setting, a proper space 14 is formed between the outer surface of the ahdesive 10 and the inner peripheral surface of the lens storage part 12 as shown in a left-side cross section and the adhesive layer of the adhesive 10 deforms freely in the space 14 in radial directions of the lens 8.

Description

TECHNICAL FIELD The present invention relates to a lens holding device, and more particularly to a lens holding device that fixes and holds a lens to a lens frame via an adhesive.

PRIOR ART Conventionally, a structure as shown in FIGS. 1 and 2, for example, has been adopted as a structure for fixing and holding a lens to a mirror frame via an adhesive. That is, the lens holding structure shown in FIG. 1 is such that the lens 1 is dropped into the lens storage part 3 of the lens frame 2, and the lens 1 is held in a lens holding part that protrudes 1" from inside the lens frame 2 in the radial direction. 4, and by filling an annular gap between the lens 1 and the inner peripheral surface of the lens storage portion 3 in the lens frame 2 with an adhesive 5 and hardening the lens 1. is fixedly held on the lens frame 2.Means for filling the annular gap 9 with the adhesive 5 include, for example, injecting the adhesive 5 through a syringe having a needle at the tip; A means of filling the adhesive through a rod-like member having a sharply shaped portion is adopted.Furthermore, FIG. 1 shows an example in which the adhesive 5 is filled after the lens 1 is stored in the lens storage portion 3. However,
As shown in FIG. 2, a means for applying (adhering) an adhesive 5 to the lens 1 before housing it in the lens frame 2 is also generally used. That is, as shown in FIG. 2, the lens 1 is rotated about the optical axis, the adhesive 5 is applied to the outer peripheral surface of the lens 1 via the needle-like member 6, and then the lens 1 is attached to the lens frame 2. This is a means for storing the lens 1 in the lens storage section 3 of the lens 1 and fixing and holding the lens 1 to the lens frame 2 by curing the adhesive 5. In this lens 1 holding structure, the lens 1 can be fixedly held on the lens frame 2 in exactly the same manner as in FIG. 1.

However, the conventional lens holding structure described above has the following problems and is not satisfactory as a lens holding device.

(1) Since the outer periphery of the lens 1 was directly fixed and held on the lens frame 2 via the adhesive 5, when the adhesive 5 hardens and contracts, the outer periphery of the lens 1 moves toward the inner periphery of the lens frame 2. As a result of the strong pulling, distortions (backslashes, cracks) occurred in the precision of one surface of the lens, and the optical characteristics of the lens 1 were significantly deteriorated.

(2) In the above conventional configuration, the centering of the lens 1 may be adjusted before the adhesive 5 hardens; Lens 1 after the adhesive 5 has hardened due to misalignment.
The centering could not be performed accurately.

As a configuration other than the above configuration, JP-A-58-19581
There is a technique described in Publication No. 1, but even in this configuration, the lens is directly fixed to the lens frame with adhesive, so the difference in linear expansion between the lens and the lens frame due to temperature changes is reduced. There is a problem in that internal stress is generated due to this, causing large distortion on the lens surface and significantly deteriorating the optics 41 of the lens.

Further, there is also the problem that the positioning in the axial direction and the holding strength are not appropriate.

Purpose of the Invention The present invention has been made in view of the problems of the prior art described above, and its purpose is to maintain the optical performance of the lens even if there is shrinkage due to curing of the adhesive or changes in the operating temperature. It is an object of the present invention to provide a lens holding device capable of holding a lens without affecting its characteristics in any way.

SUMMARY OF THE INVENTION The present invention provides a lens storage section in a lens frame whose inner diameter is larger than the outer diameter of the lens, and an adhesive interposed between the outer peripheral surface of the lens and the lens storage section to connect the lens and the lens frame. The object of the present invention is achieved by fixing the lens through the lens and maintaining and forming an appropriate space between the outer surface of the adhesive on the outer peripheral surface of the lens and the inner peripheral surface of the lens storage portion. It is.

Embodiments Hereinafter, embodiments of the present invention will be described in detail using the drawings from FIG. 3 onwards. In addition, in the following explanatory diagram, the third
In Figures 5 and 6, the right side of the optical axis shows the cross section of the adhesive before it hardens (uncured), and the left side shows the cross section of the adhesive after hardening. It shows.

FIG. 3 shows a first embodiment of the lens holding device 7 according to the present invention. Lens holding device 7 as shown in the figure
It is composed of a lens 8 as a held object, a lens frame 8 that holds the lens 8, an adhesive 10 for adhesively fixing the lens 8 to the lens frame 9, and a fixing jig 11.

The lens 8 is housed in a lens accommodating part 12 provided in the lens frame 9, and comes into contact with a lens holding step 13 formed in the lens accommodating part 12 in a direction perpendicular to the optical axis ρ direction, so that its light is The configuration is configured such that axial positioning is performed. The inner diameter of the lens accommodating portion 12 is appropriately larger than the outer diameter of the lens 8, and the lens 8 is interposed between the outer circumferential surface 8a of the lens 8 and the inner circumferential surface of the lens accommodating portion 12. It is adhesively fixed to the lens frame 9 via an adhesive 10.

When the adhesive 10 is in an uncured state, as shown in the right sectional view, the adhesive 10 is attached to a fixing jig 11 having an annular or divided structure.
For example, when the fixing jig 11 is removed after the adhesive 10 has hardened, the outer surface of the adhesive 10 and the inside of the lens housing 12 are held together as shown in the left sectional view. The structure is such that a space 14 is appropriately formed between the surface and the surface.

The fixing jig 11 has a release agent applied to the contact portion with the adhesive 10, and a lens holding portion 11a for fixing and holding the outer peripheral edge of the lens 8 is provided on the top thereof. That is, when forming the uncured adhesive 10 into a cross-sectional shape using the fixing jig 11, the lens holder 11a presses and fixes the lens 8 until the adhesive 10 is cured. It has become.

The adhesive 10 may be attached to the entire outer circumference of the lens 8, or as shown in FIG. 4, a plurality of adhesives 10 may be attached to the outer circumference of the lens 8. . Further, in order to make the bonding between the adhesive 1o and the lens frame 9 more reliable, it is preferable to form a dovetail-shaped adhesive filling part 15 in the lens holding step part 13. good.

According to the above configuration, the adhesive layer of the adhesive 10 attached to the lens outer circumferential surface 8a can freely deform within the space 14 in the radial direction of the lens 8, so that the temperature changes depending on the usage environment. Even if the lens 8 expands or contracts to some extent, it can be absorbed by the radial deformation of the adhesive layer. Therefore, the optical characteristics of the lens 8 will not deteriorate due to changes in the temperature at which the lens 8 is used. Also, lens 8
If the adhesive 10 is cured with a space 14 formed between the outer surface of the adhesive layer of the adhesive 10 attached to the outer peripheral surface 8a and the inner peripheral surface of the lens housing part 12 in the lens frame 9, the adhesive 10
Even if shrinkage occurs during curing, the adhesive layer on the outer circumferential surface 8a of the lens deforms in the radial direction, thereby preventing optical distortion of the lens 8.

Further, according to the above configuration, it is possible to sufficiently secure the holding force of the lens 8 in the optical axis direction and the holding force between the lens 8 and the lens frame 9, and the lens 8 can be stably held.

FIG. 5 shows a second embodiment of the invention. The feature of this embodiment is that the bonding surface between the lower surface of the fixing jig 11 and the adhesive 10 is the same as that of the lens frame 9.
The point is that it is configured to be set and configured to be approximately on the same plane as the lens holding step portion 13 in . That is, the bonding surface between the lower surface of the fixing jig 11 and the adhesive 10 is approximately the same as the lens holding stepped portion 13 of the lens frame 9.
The joint surface between the lens holding step 13 and the parallel adhesive 10 in the lens storage/storage part 12 is recessed in the axial direction. Since the other configurations are the same as those shown in FIGS. 3 and 4, the same members are given the same reference numerals and their explanations will be omitted.

According to the above configuration, the adhesive 10 on the outer circumference of the lens 8 can be more easily deformed in the radial direction, and the functions and effects described in the first embodiment can be improved.

FIG. 6 shows a third embodiment of the present invention. The feature of this embodiment is that the adhesive 10 is formed to have an I-shaped cross section and is adhered and filled into the outer circumference 8a of the lens 8 and the adhesive recess 16 recessed in the lens frame 9. . The rest of the structure is the same as that of the first embodiment, so the same members are given the same reference numerals and the explanation thereof will be omitted.

Also in the above configuration, the adhesive 1o can be more easily deformed in the radial direction, and the occurrence of optical distortion in the lens 8 can be more reliably prevented. Other functions and effects are the same as those of the first embodiment, so their explanation will be omitted.

Effects of the Invention As described above, according to the present invention, the adhesive attached to the outer periphery of the lens can be deformed in the space between it and the inner periphery of the lens accommodating portion. This deformation can absorb the internal stress caused by temperature changes over time, maintaining the optical properties of the lens at high performance.
It is something.

[Brief explanation of drawings]

1 and 2 are explanatory diagrams of the prior art of the apparatus according to the present invention, FIG. 3 is a cross-sectional explanatory diagram showing the first embodiment of the present invention, and FIG. 4 is an illustration of an example of adhesive adhesion structure. A plan view, FIG. 5 is an explanatory cross-sectional view showing a second embodiment of the present invention, and FIG. 6 is an explanatory cross-sectional view showing a third embodiment of the present invention. 8... Lens 9... Lens frame 10... Adhesive 12... Lens housing section 14... Space section Fig. 1 Fig. 2 Figure 3 Figure 4 n Figure 5 Figure 6

Claims (4)

[Claims] (1) In a lens holding device for fixedly holding a lens on a lens frame, the inner diameter of the lens storage portion in the lens frame is larger than the outer diameter of the lens, and the lens and the lens frame are connected to each other. The lens is fixed via an adhesive interposed between the outer circumferential surface of the lens and the lens accommodating section, and an appropriate space is maintained between the adhesive outer surface of the outer circumferential surface of the lens and the inner circumferential surface of the lens accommodating section. A lens holding device characterized in that: (2) Claim 1, wherein the adhesive interposed between the outer peripheral surface of the lens and the lens storage portion is formed in a cross-sectional shape. Lens holding device as described. (3) A patent claim characterized in that, in the adhesive formed in a cross-sectional shape, a joint portion with a lens holding step in the lens frame is set inward of the axis line from the lens holding step. The lens holding device according to item 1 or 2. (4) A part of the anchor for preventing the adhesive from peeling off is formed on the joint surface of the lens frame with the adhesive. Third
Lens holding device as described in section. (5) The adhesive interposed between the outer circumferential surface of the lens and the lens storage portion is formed in a cross-sectional shape and is interposed, as set forth in claim 1. lens holding device.