JPS59202414A - Plastic lens and lens holder - Google Patents

Abstract

PURPOSE:To allow lenses to determine an optical axis mutually and to maintain performance without any secondary work, and to facilitate assembling operation, by fitting a lens support piece which is united with a synthetic resin lens in a cut part, and deciding the optical axis deviation of a lens group by the clearance. CONSTITUTION:When synthetic resin lenses A-C are assembled, respective support pieces 21 of the lens A are positioned at cut parts 33 among left-side lens support pieces 31 of the lens B in the order of A-C. Then, support pieces of the both are fitted in cut parts 33 and 32 at the same interval, and the lens A is jointed to the left side of the lens B at the interval corresponding to the length of the support pieces 21 and 31. Similarly, the lens C is attached to the right side of the lens B by fitting supporting pieces 32 and 42 in cut parts 36 and 42 to fit them at the interval corresponding to the length of the support pieces 32 and 42, constituting the specific lens group consisting of the three mutually-coupled lenses A-C.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plastic lens, and more particularly to a fixing structure for a plastic lens in a lens group including the plastic lens.

A photographic lens of a camera, an eyepiece of a finder, etc. are constructed by combining two or more lenses, and each lens is arranged at a predetermined distance apart. Traditionally, glass lenses have often been used for these lenses, but recently plastic lenses have been adopted.

This plastic lens, for example, which constitutes the eyepiece of a finder optical system, has three plastic lenses 1, 2, and 3 implanted on the left side, as shown in Figure 1a. A convex lens 1 is placed on the right side, a convex lens 3 is placed on the right side, and a concave lens 2 is placed between the biconvex lenses 1.3. In order to fix each lens 1.2.3 adjacent to each other so as to maintain a predetermined separation distance, flat surface portions 2a perpendicular to the lens optical axis, 2'b is provided, and a short cylindrical distance maintaining part 1 & extending parallel to the optical axis is integrated on the outer peripheral edge of the side of the left convex lens 1 facing the four lenses 2. On the other hand, a short cylindrical distance maintaining portion 3a extending parallel to the optical axis is integrally formed on the outer peripheral edge of the surface of the right convex lens 3 facing the concave lens 2. The holding portions 1a, 3. of each convex lens 1.3. Each lens 'p1.2.3 is inserted into the fixing tube 5 with the tip surfaces of the lens 'p1.2.3' brought into contact with the flat surface portions 2a) and 2b of the concave lens 2, respectively. In this state, each lens 1.2.
The outer circumferential surface of the convex lens 3 fits tightly into the inner circumferential surface of the fixing tube 5, the outer circumferential edge of the convex lens 1 abuts the lens grouping part 5a of the fixing tube 5, and the outer circumferential edge of the convex lens 3 The optical axes of each lens are aligned and a predetermined distance is maintained by being held down by a lens grouping frame 6 screwed onto the fixing tube 5.

As another known configuration, the lens group shown in FIG. In the figure, from the left, a convex lens 11 made of plastic, a concave lens 12 made of glass, and a convex lens 13 made of plastic are arranged in this order.
and is fixed by a lens group frame 16.

In the first FXI b, the plastic lens 11
．． 13, its outer peripheral edge extends parallel to the optical axis of the lens, and the tip surfaces 11b%1 of the extending portions 11t, , 13a
3b is the outer periphery 9 portion 1 of the curved surface of the glass lens 12, respectively.
2a, 12b, and are part of the curved surface of the glass lens 12.
and are in perfect contact with each other.

Furthermore, FIGS. 2a and 2b show a conventional example different from that shown in FIG. 1 a1b, in which the conventional example shown in FIG. The plastic lenses 17 and 19 are provided with protrusions 17a and 19a, respectively, and these protrusions 17d and 119d are in contact with the lens support end surfaces 188 and 180 of the plastic lens 18 disposed in the middle.

Further, in FIG. 2, only one plastic lens 19 is provided with a protrusion 19,1, and this protrusion 19d is in contact with an end surface 180 of a lens support portion of another plastic lens 18 arranged adjacently. .

The other fixing cylinder 15 and presser frame 16 have the same structure as shown in FIG. In the above conventional technology, when the lens is inserted into the lens frame using a seven-lunge-shaped ring integrally formed on the plastic lens or a rod-shaped foot formed in the thrust direction,
This lens holding device has determined lens spacing and is more efficient than the normal drop-in method.

However, it has the following drawbacks.

Plastic lenses are molded using a variety of methods, but the surface that fits into the lens frame (the outer circumferential surface of the lens) is prone to cracks and other irregularities due to gate processing. Also, making it a perfect circle is extremely unsightly. Therefore, when the lenses are inserted and held in the lens frame, the relative positions between the lenses are determined by the tilted state with respect to the lens frame, which causes optical axes to shift in the lens group. This optical axis misalignment of the lens group causes a significant deterioration in the performance of the lens system, and usually requires deburring and peripheral processing after molding for a single lens.

Furthermore, in the prior art, even if a mistake occurs in assembling the lens group, such as inserting the lenses into the lens frame in the wrong order, or holding the lenses in the wrong order, the lens group is assembled as is. If the wrong lens group is inserted, the performance will not only deteriorate, but the lens will not function as a lens at all. As a result, post-assembly inspections were required, defective products were often produced, and workability was extremely poor.

Therefore, the present invention has been developed to eliminate the various drawbacks of the prior art.

Below, embodiments of the plastic lens and lens holding device of the present invention will be explained in detail with reference to the drawings.

First, FIGS. 3 to 5 show three plastic lenses A, B, and O that are to be held in the lens holding device of the present invention.

Therefore, the plastic lenses A, B, 0 have outer j, j1 parts 20a, 30a in the lens body 20.40 consisting of a convex lens and the lens body 30 consisting of a concave lens, respectively.
, 40a and each outer peripheral portion 20a, 30a, 4
0a respectively in the thrust direction, each lens body 20.
A plurality of fan-shaped lens support pieces 21, 31, 32, and 41 having the optical axis of 30.40 as the center point 0 are arranged, and are integrally molded from an optical resin material.

Further, the plastic lens A is adjacent to the left side of the plastic lens B, and the plastic lens C is adjacent to the right side of the plastic lens B to constitute a lens system, and each of the plastic lenses A, B, O each lens support piece 21.31.32
．． Reference numeral 41 indicates that the lens support pieces are arranged in a mutual relationship corresponding to the order in which the plastic lenses A, B, and O are held.

That is, each 1/lens holding piece 2 of plastic lens A
1 is each lens support piece 31 on the left side of the plastic lens B
corresponding to each lens support piece 41 of the plastic lens a.
has a corresponding relationship with each lens support piece 32 on the right side of the plastic lens B, and each lens support piece 21.31.32.4
1 will be explained in detail with reference to FIGS. 3 to 5.

First, each lens support piece 21 of the plastic lens A is
Consisting of three lens support pieces 21a, 21b%210, each lens support piece 21a121b, 21c is the third
As shown in FIG.
a, 21 b, 21 Q are composed of fan-shaped pieces having a sector angle β1 with the optical axis as the center point 0, and both end surfaces 23 thereof as well as the end surfaces 23 of the lens support piece 21 and each lens support piece 31 on the left side of the plastic lens B Therefore, the interval angle α1 between each lens support piece 21a, 21b% 210
The inner dimension (α1) of each notch 22 is formed to correspond to the outer dimension (fan-shaped angle β2) of each lens support piece 31 on the left side of the plastic lens B, which will be described later.

In addition, each lens support piece 21 &
The diameter of the inner peripheral surface 25 of % 21 bs 21 c is larger than the effective diameter of the lens system, and the length in the thrust direction of each lens support piece 21 &% 21C is the same as that of other plastic lenses B. , O with a length necessary for a predetermined lens spacing required when configuring a lens system with O, and furthermore, the tip surface of each lens support piece 31 forms a joint surface 24 with another lens B. It is.

On the other hand, regarding plastic lens B, Fig. 4 a r
As shown in y eL, each lens support piece 31 on the left side has three lens support pieces 31a, 31bs31c, each lens support piece 21aN21b of the plastic lens A described above,
210, and a fan-shaped angle β2 (see FIG. 4C) corresponding to the inner dimension (α1) of each notch 22 formed between 210, and a notch with an interval angle α2 between each lens support piece 31a, 31b). The part 33 is the outer size of each lens support piece 21a, 211) and 21Q of the plastic lens A (
It is formed in correspondence with β1).

In addition, other configurations, namely, each lens support piece 31 a
, 31 b% Length of 310, inner peripheral surface 34, both end surfaces 35
The structure is formed to correspond to each lens support piece 21 and notch 22 of the plastic lens A.

Reference numeral 39 denotes the end surface of each lens support piece 31, 32, which is the joint surface with the plastic lens A10.

Furthermore, each lens support piece 41 of the plastic lens O has four lens support pieces 41a141t)% 4ics 4
1d and at a constant interval α3 when viewed from the lens plane.
Each lens support piece 41a541b, 41c, 41d is formed of a =tV piece with a fan-shaped angle β3 with the optical axis as the center point 0, and its both end surfaces 4
3 is the fitting surface with each lens support piece 32 on the right side of the plastic lens B, which will be described later, together with the end surface 43 of another lens support piece 41. The inner dimension (α3) of the notches 42 between the lens support pieces 41 is determined by the inner dimension (α4) of each cutout 36 between the right lens support pieces 32 of the plastic lens B (described later) and the outer size of each lens support piece (α3).
It is formed to correspond to the fan-shaped angle β4).

Therefore, each lens support piece 3 on the right side of the plastic lens B with respect to each lens support piece 41 of the plastic lens O.
2 is 4 lenses, support piece 32&% 32b% 320
% 32d, and each lens support piece 32&, 32
b, 320% 32d is also a sector angle β with the optical axis as the center point 0
A notch 36 consisting of 4 sector-shaped pieces and having a constant interval α4.
It is placed with

In addition, other configurations, namely, each lens support piece 32.41
The length of lens B and lens O is formed to have the required length, and the inner circumferential surfaces 37 and 44 are formed to have a larger diameter than the effective diameter of the lens system. Reference numeral 45 denotes a joint surface with the lens B, which is formed by the tip end surface of each lens support piece 41.

Reference numeral 38 indicates both end surfaces of each lens support piece 32 of the plastic lens B.

As is clear from the above description, plastic lenses A and O are connected adjacently to the left and right sides of plastic lens B.
For this, the number of each lens support piece 21.31 on the former and left side was changed to 3, while the number of each lens support piece 41.32 on the latter and right side was changed to 4, so that each plastic The lenses A, B, and O are configured so that they can be accurately combined according to the combination required for the combination of lens systems at all times.

That is, each plastic lens A having the above configuration,
When assembling B and O, as shown in FIG. 6, place the plastic lens A on the left side of the plastic lens B, and the plastic lens O on the right side thereof, and place each lens support piece 21 of the plastic lens A on the plastic lens B. After aligning with each notch 33 between each lens support piece 31 on the left side of (by this alignment, each lens support piece 31 can be aligned with the notch 22 conversely), The pieces 21.31 can be fitted onto each other with a fitting fit in the recesses 33.22 between their spacings, and at the same time, with a distance corresponding to the length of each lens support piece 21.31, a plastic lens A can be bonded to the left side of the plastic lens B.

In the same way, attach the plastic lens 0 to the right side of the plastic lens B by attaching each lens support piece 32, 41 to the notch 3.
6.42, the distance corresponding to the length of each lens support piece 32.41 is set to 117.
The three plastic lenses A, E, I:! A predetermined lens group can be constructed by connecting the lenses to each other.

Figs. γ a, b are explanatory diagrams regarding the misalignment of the lens group consisting of plastic lenses A, B, and 0, in which each lens support piece 21.31. Fitting surface 2 between 32 and 41
3.35.43.38 Among comrades, to some extent? The clearance δ causes a shift in the radial direction between each lens ASE and Q, and the amount of shift is the amount of deviation δ of the optical axis of the lens group.
'. In other words, the optical axis deviation δ′ is for each lens AXBX
Fitting surface 23 of lens support piece 21.31.32.41 of O
．． 35.43.38 is determined by the mutual clearance δ.

In addition, in the above explanation, three plastic lenses AXB,
Although the embodiment in which the O's are connected to each other has been described, it is of course possible to form a lens group by connecting two or four or more lenses, and the lens support piece protruding from the outer periphery of the plastic lens is Plastic lenses A, O
As in the case of plastic lens B-, there are cases where it is configured by protruding only on one side, and cases where it is configured by protruding only on one side, and cases where it is configured by protruding on only one side, and cases where it is configured by protruding on only one side, and cases where it is configured by protruding on only one side, and cases where it is configured by protruding on only one side, and cases where it is configured by protruding on only one side.
) in some cases.

Moreover, it goes without saying that the shape, number, etc. of each lens support piece of each plastic lens can be implemented while making necessary design changes. Now, using the above-described plastic lens of the present invention, a lens holding device can be constructed. The configuration will be explained with reference to FIG. 8. First, the lens frame 50 has an inner diameter corresponding to the outer diameter of the plastic lens A and a plastic lens B.
, O has a cylindrical shape with an inner circumferential surface 51 into which the plastic lenses AXB and O can be inserted, and one open end 51a of the inner circumferential surface 51 has the effective diameter of the lens group consisting of plastic lenses AXB and O secured in its inner diameter, and the plastic A protruding abutment surface 52 that abuts the outer circumference 20a of the lens person, and the other open end 51b
A screw giS54 is screwed onto the outer periphery of the holding ring 53≧j.

Therefore, the plastic lens A is inserted into the lens frame 5o, and stored while the outer peripheral part 20a of the lens body 2o is abutted against the abutting surface 52, so that the outer peripheral part 2oa of the lens A is inserted into the lens frame 5o.
Centering is performed by fitting into the inner circumferential surface 51 of o.

Next, the plastic lenses B and C are inserted into the lens frame 50, and the lens support pieces 31 and 42 of each lens BXO are fitted with the lens support pieces 21 and 32, and dropped into the lens frame 50. can be stored in the spacer connected to lens A while centering it.

Thereafter, by screwing an annular retaining ring 53 having an opening 55 with the lens effective diameter on the inner diameter onto the threaded portion 54 of the lens frame 5o,
Plastic lenses A, B, and O are in the lens frame 5o,
It is pressed in the direction of the lens abutment surface 52 and held fixed in the thrust direction.

However, if the plastic lenses AXB, 0 are housed based on the order of combination with the lens frame 50, the correspondingly protruding lens support pieces 21, 31, 32, 41 cannot be fitted to each other. , plastic lens A
, B, and O have different lengths from the distance required for a given lens group, and as shown in Figure 9, the lenses B installed at the rear protrude from the frontage 51b of the lens frame 50. As a result, the holding ring 53 cannot hold it.

Figures 10 to 12 show a second embodiment of the plastic lens of the present invention, which consists of three 7-last lenses A, B, and O, similar to the first embodiment shown in Figures 3 to 5. This shows the case where a lens group is constituted by the lenses of
1.32.41 is all 4, but its sector angle (β
), that is, the lens support piece 21) shape angle (β1
) of the lens support piece 32 to the maximum, then increase the sector angle (β2
) are made smaller (β1>β2), and lens support pieces 31 and 41 are formed to correspond to this.

The other configurations are the same as those in the first embodiment, so the same numbers are given to each part and the explanation thereof will be omitted.

Further, the structure of the lens holding device can be constructed in the same manner as shown in FIG. 8, so detailed illustration and explanation thereof will be omitted.

In general, plastic lenses are made by putting resin into a mold cavity under high pressure and high temperature and solidifying it to form a lens, so that resin entrances (gates), holes, etc. remain on the outer periphery. In the conventional structure, the relative position of the lens group is determined by the lens outer circumferential surface and the inverted state of the frame, so variations in the gate and paris cause optical axis misalignment that greatly reduces lens performance. In the present invention, the lens support piece provided integrally with the plastic lens and the notch part fit together, and the optical axis deviation of the lens group is determined by the clearance, so the lens Light with comrades! It is possible to assemble a lens group very easily by determining the 'd' and maintaining the performance of a predetermined lens system without secondary processing of individual lenses.

With conventional lens holding devices, when inserting and holding the lens in the frame, there are many defects such as the lens not being inserted properly during the sewing process, and each lens needs to be inspected one by one during the assembly process. By changing the lens support piece and notch formed on the plastic lens between adjacent lenses, it is possible to prevent incorrect insertion of lenses, maintain the performance of a given lens group, and prevent defects during assembly. Therefore, a lens holding shoulder consisting of a plurality of lens groups can be assembled very accurately and easily.

[Brief explanation of drawings]

FIG. 1 aXb and FIGS. 2 a and b are longitudinal sectional side views showing a conventionally known lens holding device, and longitudinal sectional views with some parts omitted;
Figures 3 to 5 show the first embodiment of the plastic lens of the present invention; Figures 3, 01, 4a, and 5a are perspective views of each lens; is a longitudinal cross-sectional view of the same,
Fig. 3 01 Fig. 4 Q, a, Fig. 5 0 are plan views of the same Sakura, Fig. 6 is a perspective view showing the combined state, Fig. 7 as'b shows the 8-plane misalignment of each lens. 8 is a longitudinal sectional side view of the lens holding device of the present invention; FIG. 9 is a longitudinal sectional side view showing a state in which each lens is installed in the wrong order in the lens frame; 10th to 1st
Figure 2 shows a second embodiment of the plastic lens of the present invention,
Fig. 10 a1 Fig. 11 a1 Fig. 12 a is a vertical sectional view of each lens, Fig. 10 b1 Fig. 11 b1 c1 Fig. 121 is a plan view of each lens. AXB, 0...Plastic lens 20.30.40...Lens body 20a, 30a, 40a...Outer periphery 21.31.32.41.?・Lens support 22.33.
36.42...Q notch 23.35.38.43-@-both end surfaces (fitting surfaces) 24.
39.45-・@joining surface 50...lens frame 51...inner peripheral surface 52...butting surface 53Φ・holding ring 54e@・threaded part 55...opening patent applicant Olympus Optical Industrial Cup Company Figure 1 (G) (b) Figure 2 (Q) (b) Figure 3 (G) Figure 4 (.) (b) 81- Figure 5 (C) (b) ( G) Figure 11 (C) iG Figure 12 (a) (b) Procedural amendment (voluntary) July 20, 1988 Title of invention 2 Plastic lens and lens holding device 3. Related Patent applicant: %r/, 2-43-2 Hatagaya, Shibuya-ku, Tokyo
Name (Name) (037) Orinno (Nu Kogaku Kogyo Former Mi Shikikai) President and CEO Shigeru Kitamura Male 4 Agents (Number of inventions increased by 5 amendments to 7 Subject of amendment Sheet 2, Scope of claims (1) A plastic lens consisting of a lens body and a plurality of lens support pieces each having a fan-shaped cross section and protruding along the outer circumference of the lens body. (2) The lens support pieces are arranged along the outer circumference of the lens body. Claim 1, which is provided protrudingly from the front side and/or the rear side.
Item 1: Plastic lens included. (3) The lens support piece is 6(1) of the Mu lens body.
2. The plastic lens according to claim 1, which has a corresponding shape that can be fitted closely between the respective lens support pieces on the outer periphery of the lens to be combined on the side and/or rear side. (4) In a lens holding device for storing and fixing a plurality of lenses in a lens frame while bonding them to each other, each lens has a lens support piece having a single-sided fan shape with a valley disposed on its outer periphery.
A lens holding device characterized in that it has a weight of 4g/yet by storing and fixing the lenses while placing an iron stand in the space between each lens support piece of adjacent lenses. (5) Lens support pieces each having a fan-shaped cross section and arranged around the outer periphery of each lens are arranged with varying arrangement conditions such as number and width between the lenses bonded to both the front and back sides of each lens. A lens holding device as set forth in item 4 of the scope of the claims.

Claims (3)

[Claims] (1) Each lens has a fan-shaped lens support piece centered around the optical axis along the outer periphery of the lens body, which is combined with the front side and/or rear side of the lens body. A plastic lens characterized by being arranged to correspond to the spacing between supporting pieces. (2) In a lens holding device that houses and fixes a plurality of lenses in a lens frame while bonding them to each other, each of the lenses has a sector-shaped lens support piece disposed on the outer periphery of each lens, and each lens is attached to a lens supporting piece that is adjacent to each other. 1. A lens holding device characterized in that the lens holding device is constructed by being housed and fixed while being fitted into the space between the lens supporting pieces. (3) Lens support pieces each having a fan-shaped cross section and arranged around the outer periphery of each lens are arranged with varying arrangement conditions such as number and width between the lenses bonded to both the front and rear sides of each lens. The lens holding device according to claim 2, comprising:
10