JPS6211813A - Lens having aligning mechanism - Google Patents

Abstract

PURPOSE:To center automatically and correctly a lens by screwing a holding ring for fixing a lens into a lens frame so that it abuts on a spherical part which is formed separately from an effective area of the lens on the outside peripheral part of the lens. CONSTITUTION:A lens holding part 6 whose one face and opposite face form a flat surface and a spherical surface 6a, respectively is formed in the outside peripheral part of an effective area 1a of a lens 1. The flat surface side of the lens holding part 6 is made to abut on a step difference part 4 which has been formed on the inside peripheral surface of a lens frame 2. A screw 7 is provided on the outside peripheral part of an annular holding ring 3, matched spirally to a screw 5 of the inside peripheral surface of the lens frame and screwed in, and a projecting end part 3a of the holding ring 3 is made to contact with the spherical surface 6a. In such a way, when assembling, the lens 1 is brought to centering automatically and exactly.

Description

[Detailed description of the invention] The present invention relates to a lens having an alignment mechanism.

Conventionally, as a structure for assembling a lens to a lens frame (lens support frame), a fitting concave portion having a diameter slightly larger than the outer diameter of the lens is provided on the lens frame side, and a lens body portion is also provided, and the fitting recess is provided on the lens frame side. After the lens is fitted into the recessed portion, the lens is fixed to the lens frame via a retaining ring, so that the lens can be assembled to the lens frame. In particular, in the case of a plastic lens, a structure is adopted in which a barrel portion that connects to the lens frame is provided on the outer periphery of the lens body so that the lens can be fixedly held on the lens frame.

However, the lens assembly according to the above-mentioned conventional structure has many optical points as follows. That is, first of all, in the conventional configuration described in (2), the amount of centering of the lens after it is assembled into the lens frame is only the amount of fitting clearance between the fitting recess in the lens frame and the outer peripheral surface of the lens. After lens assembly, it was impossible to perform optical axis alignment (centering) work. This is because the fitting clearance between the fitting recess in the lens frame and the outer circumferential surface of the lens is generally set to a small amount because it is necessary to precisely assemble the two.

In addition, even if the fitting slit lance is set somewhat larger, the conventional configuration described in I-1 does not have an alignment mechanism, so alignment operation after lens assembly is impossible. Setting a large fitting clearance for this would only result in more misalignment. Second, when assembling a plastic lens into a lens frame, it is necessary to set a large fitting clearance between the lens frame and the lens to absorb the expansion of the lens body at temperatures of -R. For this reason, there was a drawback that the center misalignment at room temperature became large, making it impossible to obtain the desired lens performance. Thirdly,
When plastic is used as the lens frame material 1, there is a problem that the entire lens frame expands and contracts in response to temperature changes, which increases or decreases the fitting clearance with the lens. If it is too small, the lens body will be tightened when it contracts, so the fitting clearance had to be set large in advance. As a result, there was a drawback that the center misalignment at room temperature became large, making it impossible to obtain the desired lens performance. Fourthly, high precision is required for pressurizing the fitting portion between the lens frame and the lens, which increases production costs. This drawback is the same even when the lens frame and lens are made of plastic.

The present invention has been made in view of the problems in the prior art as described above, and includes a structure in which one side of the lens can be freely joined to a lens support surface portion of a lens frame, and a ring that holds the lens joined to the support surface portion. In a lens configured to be fixedly supported on a lens frame via a lens, a spherical part having a spherical surface for centering the lens is provided on either the joining side with the support surface or the holding ring side of the lens. In addition, by providing a friction damping portion on the joint surface side with the support surface portion of the lens frame, various problems in the prior art described in I-1 are solved. Embodiments of the present invention will be described in detail below with reference to the drawings.

What is shown in FIG. 1 is a lens l according to the present invention, a lens frame 2 that holds this lens l, a presser ring 3 for pressing and fixing the lens l in the thrust direction of the lens frame 2, etc. It is.

As shown in the figure, the lens 1 is configured such that its negative side can be freely joined to the lens support surface 4 of the lens frame 2, and the lens 1 joined to the support surface 4 is screwed into the female thread 5 of the lens frame 2. It is constructed so that it can be fixedly held on the lens frame 2 via a presser ring 3 attached thereto.

The abutment surface of the lens l with the presser ring 3 is integrally provided along the outer periphery of the lens body 1a at the outer diameter part of the effective field of view of the lens body la, and this abutment surface has a A spherical surface 6 different (separate) from the spherical shape of the portion 1a
The spherical surface part 6 for alignment operation formed in the lens body part 1a is
It is integrated with. This spherical surface part 6 for centering operation is set at a position that does not affect the performance of the lens 1, and the lens 1 is automatically aligned (centered) by the cooperation between the spherical surface 6a and the presser ring 3. ). That is, the spherical surface 6 of the spherical surface portion 6 for alignment operation in the lens 1
a has a spherical shape concentric with the axis of the lens body 1a, and the male threaded portion 7 of the retainer ring 3 and the contact portion 3a of the retainer ring 3 with the spherical surface 6a are connected to the lens frame 2. Processed and formed concentrically with the shaft core. Therefore, when the lens 1 is fixed by being pressed in the axial direction of the lens frame 2 via the presser ring 3 screwed onto the male threads 1 and 5 of the lens frame 2, the lens l is attached to the presser ring 3. It is configured to be automatically aligned by the alignment action between the contact portion 3a and the spherical surface 6a. In other words, the structure is such that the lens 1 cannot be securely fixed unless it is perfectly centered.

It is preferable that the radius of curvature of the spherical surface 6a of the spherical surface section 6 for alignment operation be set relatively small so as to improve alignment accuracy. Further, it goes without saying that the spherical surface section 6 for alignment operation may be provided all around the lens body section 1a, or may be equally distributed around the lens body section 1a and divided into a plurality of parts.

According to the configuration described above, the lens l is inserted into the lens frame 2, and then the retainer ring 3 is screwed onto the female threaded portion 5 of the lens frame 2, and the lens l is inserted through the contact portion 3a of the retainer ring 3. By pressing the lens l in the thrust direction and fixing it to the lens frame 2, the lens l can be automatically aligned.

Therefore, according to the lens l according to the present invention, the outer diameter dimension of the lens l and the inner diameter dimension of the lens holding part in the lens frame 2,
Even if the difference between the lens 1 and the lens frame 2, that is, the clearance between the lens 1 and the lens frame 2 is large, the alignment of the lens 1 can always be performed reliably regardless of the magnitude of this clearance amount. Also,
Since alignment can be performed regardless of the amount of clear rice between the lens 1 and the lens frame 2, it is possible to align the lens 1 and the lens frame 2 regardless of the amount of clear rice.
Even when both are made of plastic materials, it is possible to set a large amount of clearance between the lens l and the lens frame 2, which is the -0 dimension, and to prevent expansion of each member due to temperature changes.

Shrinkage deformation can be reliably absorbed. Moreover, even if the clearance amount (n+n') is set to a large value in this way, the center deviation does not occur as in the conventional case, so there is an advantage that a predetermined lens performance can be reliably maintained. Also,
According to the lens 1 according to the present invention, it is only necessary to process the lens 1, the lens frame 2, and the presser ring by adjusting the degree of rotation of the lens 1, the fitting part between the lens 1 and the lens frame 2, unlike the conventional method. No precision is required, thus reducing production costs.

27 and 3 show a second embodiment of the present invention. The feature of this embodiment is that a thin stress absorbing section 8 is formed between the lens main body section 1a and the spherical section 6 for adjusting and centering.

According to the above configuration, even if an unreasonable force is applied to the lens body la side while centering the lens 1 through the presser ring 3 and fixing the lens l to the lens frame 2, this Since the stress is absorbed by deforming the stress absorbing portion 8, no unreasonable force is applied to the lens body portion 1a. Therefore, the optical characteristics of the lens body portion 1a are always maintained at a predetermined level. Further, the alignment operation spherical surface part 6 and the stress absorbing part 8 may be provided all around the lens body part 1a, but as shown in FIG. Of course, it may be arranged. child? In some cases, when aligning lens 1? Care must be taken to prevent unbalanced forces from acting on the lens 1. It should be noted that the action of the Deaf e-Kokai 2 is the same as that of the first embodiment, so the explanation thereof will be omitted. - FIG. 4 shows a third embodiment of the invention. The feature of this embodiment is that a friction reduction sheet 9 is interposed between the lens support surface portion 4 of the lens frame 2 and the joint Q'lb of the lens support surface portion 4 of the lens l to reduce frictional resistance. The point is that it was constructed as follows.

According to the above configuration, it is possible to reduce the frictional resistance between the lens l and the lens support surface portion 4 when centering and fixing the lens 1 via the presser ring 3, so when fixing the lens 1, The operability and centering accuracy of the centering operation can be further improved.

Although the friction damping sheet 9 is used in the above embodiment, the invention is not limited to this. For example, the mirror surface portion 6 for alignment operation in the lens l may be made of a different material from the lens body portion 1a. , and may be composed of a member having a smaller coefficient of friction than the member of the lens body portion 1a.
Both members 1a.

The integral molding of 6 can be performed, for example, by double molding, outsert, or the like. In addition to the above, lens l
Alternatively, the lens frame 2 may be constructed by applying a powder or the like having low frictional resistance to each of the joint surfaces lb and 4. In addition, other configurations.

Since the operation is the same as that of the first embodiment, the explanation thereof will be omitted.

What is shown in FIG. 5 is a fourth embodiment of the second invention. The feature of this embodiment is that the centering action spherical portion 6 in the lenses l shown in the first to third embodiments is
The point is that the spherical surface 6a is formed on the side of the joint surface lb with the mirror finish 2. The lens support surface 411 of the lens frame 2 is configured to protrude so as to cooperate with the spherical surface 6a of the lens 1 to align the two lenses 1 as shown in FIG. 4 is about to be processed and formed concentrically with the □ axis of the lens frame 2. It was. The contact surface lc' with the presser ring 3 in the register and the slider 1 is formed into a flat surface as shown in the figure. The rest of the configuration is the same as that of the first embodiment, so the explanation thereof will be omitted.

In the above structure as well, the lens l is secured by the alignment effect between the spherical surface 6a of the alignment operation spherical surface part 6 and the lens support surface part 4, that is, the lens l cannot be securely fixed unless aligned. It becomes possible to align and fix the center. Other effects.

The effect is the same as that of the first embodiment, so the explanation thereof will be omitted.

As described above, according to the present invention, the alignment of the lens is reliably performed when the lens is fixed to the lens frame, so even if the fitting clearance between the lens and the lens frame is large, it is possible to It is possible to fix the lens while performing an accurate centering operation, and the performance of the lens after assembly can always be maintained at a predetermined level.

In addition, even if the clearance between the fitting part between the lens and the lens frame is set large, the lens can be centered accurately, so expansion and contraction of each member due to temperature changes can be absorbed, and the lens Performance can always be maintained in a normal state.

[Brief explanation of drawings]

1 is a side sectional view showing a first embodiment of a lens according to the present invention, FIG. 2 is a side sectional view showing a part of a second embodiment of a lens according to this invention, and FIG. FIG. 4 is a side sectional view showing a part of the third embodiment of the lens according to the invention, and FIG. 5 is a side sectional view showing a part of the fourth embodiment of the lens according to the invention. be. 1... Lens la... Lens body part 2... Lens frame 3... Holding ring 6... Spherical surface part for alignment operation 6a... Spherical surface 8... Stress absorbing part 9... Friction damping sheet patent applicant Olympus Optical Industry Co., Ltd. Representative Patent attorney Takeshi Nara 3, presser ring 6, spherical surface for alignment operation Fig. 2 Fig. 3

Claims (1)

[Claims] (1) In a lens configured such that one side of the lens can be freely joined to a lens support surface of a lens frame and can be fixedly held on the lens frame via a lens holding ring joined to the support surface, A spherical surface part for aligning the lens is provided on the joint surface of either the support surface part of the lens frame or the presser ring in the lens, and a friction damping part is provided on the joint surface side with the support surface part of the lens frame. 1. A lens having an alignment mechanism, characterized in that the lens is configured by providing a centering mechanism.