JPH08190004A - Composite optical lens - Google Patents

Abstract

PURPOSE: To easily produce a composite optical lens formed by joining two or more lens bodies at a low cost and to obtain such a new composite optical lens that a special shape such as an aspherical lens can be easily formed and further the lens can be rapidly formed. CONSTITUTION: This composite optical lens is produced by joining a convex lens 1 having low refractive index and a concave lens 2 having high refractive index. The convex lens and the concave lens consist of one of optical glass, thermosetting resin, and thermoplastic resin. One of these lenses is formed by injection molding. Especially, it is preferable that after one of them is formed, the formed lens is set as an insert in the die for injection molding and then insert molding is performed to join both lenses.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite optical lens suitable for correcting chromatic aberration, spherical aberration and the like by combining two or more lens bodies.

[0002]

2. Description of the Related Art Conventionally, achromatic lenses and apochromatic lenses from which chromatic aberration and the like are removed, and compound lenses from which spherical aberration and the like are corrected are usually made of optical glass. In this type of compound lens, for example, the refracting surfaces of two single lenses (a total of four surfaces) are molded by polishing, and the cemented surfaces of the two lenses are joined so that the optical axes of the two single lenses are aligned with each other. It is made to adhere with an adhesive. As this adhesive, a thermosetting adhesive, a solvent volatilizing adhesive (balsam), an ultraviolet curable adhesive, or the like is used.

On the other hand, in recent years, plastic lenses using synthetic resin instead of glass have been actively manufactured, and the demand is increasing because they are inexpensive and lightweight. In addition, several proposals have been made in recent years for a compound lens using this plastic lens, such as one in which a glass lens and a plastic lens are joined together, one in which plastic lenses are joined together, and the like.
09326, JP-A-60-2358, JP-A-60-
56544, JP-A-63-89343, JP-A-63.
-110410, Actual Kaihei 1-81601, Actual Kaihei 2
No. 119601.

In manufacturing these compound optical lenses, in the case of joining a glass lens and a plastic lens, for example, after polishing the glass lens, the glass lens is set in a casting mold and synthetic resin is added. After the injection, the synthetic resin is temporarily hardened and brought into close contact with the glass lens, and after that, the optical axes of the glass lens and the synthetic resin lens are adjusted so that the synthetic resin is fully hardened. When joining plastic lenses together, for example,
One side of the acrylic plate is cut and polished to form a desired refracting surface, which is set in a casting mold, the styrene resin prepolymer is poured onto the refracting surface, defoamed, and then heat-cured. This is taken out of the mold and, after removing the strain by annealing, a surface different from the refraction surface is processed by cutting and polishing to obtain a desired shape.

[0005]

Among the above-mentioned conventional composite optical lenses, when optical glass is used, it takes a lot of time and a high skill to process a single lens, resulting in high manufacturing cost. However, it is extremely difficult and expensive to manufacture an aspherical lens used for correcting aberrations.

On the other hand, when the glass single lens and the plastic single lens are cemented together, the defoaming treatment must be completely performed during the casting, which requires skill and technical management. There is a point. Further, since the ultraviolet curable resin material is expensive and has a semi-fluid state, it is difficult to handle, and there is a problem that the storage thereof needs to be careful. Furthermore, since many plastics do not easily transmit ultraviolet rays, it is difficult to cure when two or more plastic lenses are joined, especially when the wall thickness is large, and the desired shape, hardness, and performance cannot be obtained. There is.

Further, when the plastic lenses are joined together, it is necessary to completely perform the defoaming treatment at the time of casting as in the above case, which requires skillful techniques and is troublesome to manage. In addition, there is a problem that it takes a long time for molding. Further, since it is necessary to add a polymerization initiator and an ultraviolet curing agent to the prepolymer, there is a problem that the management and handling of the prepolymer require attention.

[0008] Further, as a common problem in each of these manufacturing techniques, it is necessary to align the optical axes of the lenses to be cemented, and this optical axis alignment work requires skill in the above manufacturing method, and is troublesome. There is a problem of this.

Therefore, the present invention is to solve the above-mentioned problems, and the problem is that it can be manufactured easily and at low cost, and that special shapes such as aspherical lenses can be easily formed, and the formation is quicker. It is to realize a possible new compound optical lens.

[0010]

Means for Solving the Problems The means taken by the present invention to solve the above-mentioned problems is a composite optical system having a lens body having a predetermined optical surface and another lens body bonded to the lens body. In a lens, at least one of the lens bodies
One is formed by injection molding using a synthetic resin.

Here, it is preferable that the lens body is formed by insert molding using another lens body as an insert.

Further, it is preferable to form a concavo-convex portion which becomes an undercut portion at the time of mold release in the injection molding on the joint surface between the lens body and the other lens body.

In this case, it is preferable that the uneven portion is provided with a non-undercut surface formed on the center side of the lens body and an undercut surface formed on the opposite center side of the lens body. .

Further, the lens body is extended from a joint surface with the other lens body to cover the outer periphery of the other lens body, and further, the other lens body is provided on the opposite side of the joint surface. It is preferably formed so as to extend to the outer edge of the surface.

Then, the lens body is formed on each of the front surface and the back surface of the other lens body, and the lens body on the front surface side and the lens body on the back surface side are formed on the other lens body. It is preferable that they are integrally connected via the penetrating portion.

Alternatively, the lens bodies are formed on both the front surface and the back surface of the other lens body, and the lens body on the front surface side and the lens body on the back surface side are provided on the outer circumference of the other lens body. It is preferable that the outer peripheral coating portion covering the upper portion is integrally connected.

[0017]

According to the present invention, by forming at least one lens body of the composite optical lens by injection molding with synthetic resin, the handling and management of the resin becomes easy, and the desired shape, hardness and performance are compared. Since it can be realized easily and molding can be performed quickly and easily, the manufacturing cost can be reduced.

According to the second aspect, by manufacturing by insert molding using another lens body as an insert,
The resin has a relatively high adhesiveness and can be manufactured with high molding efficiency. In this case, it is preferable that the insert is supported and molded by a supporting member such as a supporting pin protruding from the cavity in the insert molding, and in particular, the supporting member is retracted from the inside of the cavity after the resin is injected and before the resin is cured. desirable. Further, it is preferable that the withdrawal of the support member is performed in conjunction with the pressure of the injected resin, and it is effective that the tip end surface of the support member is aligned with the inner surface of the cavity.

According to the third aspect of the present invention, by forming an uneven portion which becomes an undercut portion at the time of mold release of injection molding on the joint surface of both lens bodies, it is possible to enhance the adhesion force between both lens bodies, so that peeling is performed. It is possible to reduce the risk of

According to the present invention, the uneven portion is provided with the non-undercut surface formed on the center side of the lens body and the undercut surface formed on the opposite center side of the lens body, so that when molding Since stress is not applied to the center side of the lens body during the mold release, it is possible to prevent the center portion of the lens body from being deformed.

According to the fifth aspect, the lens body is extended from the joint surface with the other lens body to cover the outer periphery of the other lens body, and further, it is provided on the side opposite to the joint surface of the other lens body. By forming it so as to extend to the outer edge portion of the surface, the adhesion of both lens bodies can be increased, and therefore the risk of peeling can be reduced.

According to the sixth aspect, the lens bodies are formed on both the front surface and the back surface of the other lens body, and the front surface side lens body and the rear surface side lens body are formed on the other lens body. By integrally connecting through the penetrating portion, the adhesion between both lens bodies can be increased, and therefore the risk of peeling can be almost eliminated.

According to the seventh aspect, the lens bodies are formed on both the front surface and the back surface of the other lens body, and the lens body on the front surface side and the lens body on the back surface side are formed on the outer circumference of the other lens body. By integrally connecting with the outer peripheral covering portion that covers the lens, the adhesion of both lens bodies can be increased, and therefore the risk of peeling can be almost eliminated.

[0024]

EXAMPLES Examples of compound optical lenses according to the present invention will now be described with reference to the drawings.

Example 1 In Example 1, as shown in FIG. 1, a convex (positive) lens 1 and a concave (negative) lens 2 are cemented together. The convex lens 1 is made of a material having a low refractive index, and the concave lens 2 is made of a material having a high refractive index, and by joining them, a positive achromatic lens in which chromatic aberration and spherical aberration are corrected is formed.
Table 1 below shows combinations of materials of the convex lens 1 and the concave lens 2.

[0026]

[Table 1] Convex lens 1 Concave lens 2 1 PMMA SF2 2 PMMA PC 3 BK7 PC 4 CR-39 PC 5 PMMA Sulfur-containing urethane

Here, PMMA is methacrylic resin, PC
Is a polycarbonate resin, which is a thermoplastic resin.
CR-39 and sulfur-containing urethane are thermosetting resins. BK
7, SF2 is optical glass. The optical properties of the materials listed in Table 1 above are shown in Table 2 below together with the materials used in each of the examples described below.

[0028]

[Table 2] Glass material Refractive index (nd) Abbe number (νd) BK7 1.516 64 FK01 1.470 67 SF2 1.648 34 Thermosetting resin CR-39 1.500 58 Sulfur containing urethane 1.660 32 Heat Plastic resin PS 1.592 31 PC 1.584 30 AS 1.565 37 MH resin 1.510 57 (Arton) PMMA 1.492 58

The PS is polystyrene resin and AS is acrylonitrile / styrene copolymer resin. At least one of the convex lens 1 and the concave lens 2 of this embodiment is formed by injection molding. The manufacturing method of this example is as follows.

(In the case of a compound optical lens formed by joining optical glass and a thermoplastic resin) In order to form either the convex lens 1 or the concave lens 2, the optical glass is ground, polished, centered, or surface-coated by a known method. Processed into a predetermined shape and specifications through steps, set it in the injection mold, clamp the mold, inject the predetermined resin into the mold cavity, cool and solidify the resin, then take it out .

(In the case of a compound optical lens made by joining synthetic resins) Either the convex lens 1 or the concave lens 2 is formed by injection molding or transfer molding, and this is set as an insert in a mold for injection molding, After tightening, a predetermined resin is injected into the cavity of the mold, and the resin is cooled and solidified, and then taken out.

Here, when manufacturing a composite optical lens by joining a thermosetting resin and a thermoplastic resin, first, an insert is formed from the thermosetting resin, and the insert is set in a mold to set the thermoplastic resin. Is poured and solidified by cooling. By doing so, a highly accurate compound lens can be formed without the shape of the thermosetting resin being broken during insert molding.

In the case of a composite optical lens formed by joining thermoplastic resins together, basically either one may be molded as an insert. However, if the insert is formed by using a resin with a low melting temperature and insert molding is performed with a resin with a high melting temperature, the thermal decomposition of the insert occurs. It is necessary to use a resin having a high melting point as an insert and a resin having a low melting temperature for insert molding. In the case of joining resins with a small difference in melting temperature, if only the surface portion of the insert is slightly melted during insert molding, the bonding strength will improve due to melting, so the shape accuracy will be slightly inferior, but the lens On the contrary, it is preferable from the viewpoint of prevention of peeling.

[Second Embodiment] FIG. 2 shows a second embodiment according to the present invention.
It shows the structure of. Example 2 is a compound optical lens having a three-lens structure, and includes a convex lens 3 and the convex lens 3.
The concave lenses 4 and 5 are cemented one by one on the front and back. The convex lens 3 is made of a material having a low refractive index, the concave lenses 4 and 5 are made of a material having a high refractive index, and a cemented lens forms a positive achromatic lens in which chromatic aberration and spherical aberration are corrected. Table 3 below shows combinations of materials of the convex lens 1 and the concave lens 2.

[0035]

[Table 3] Convex lens 3 Concave lens 4 Concave lens 5 6 BK7 PC AS 7 PMMA PC PS 8 PMMA PC PC 9 MH resin SF2 PC 10 CR-39 PS PC 11 BK7 Sulfurized urethane PS 12 CR-39 PC Sulfur containing urethane

These compound optical lenses include one glass lens and two thermoplastic lenses, one thermosetting plastic lens and two thermoplastic lenses.
It is made up of a combination of three lenses or three thermoplastic lenses. Also, a combination of 2 thermosetting plastic lenses and 1 thermoplastic lens, glass lens, thermosetting plastic lens,
It is also possible to combine a single thermoplastic lens and the like.

The manufacturing method of this embodiment is as follows. First, in the case of a combination of optical glass and a thermoplastic resin, the optical glass is ground, polished, by a known method.
By forming the shape and specifications through the steps of centering and surface coating, setting it in the injection molding die and clamping it, injecting the resin and cooling and solidifying it,
A compound lens consisting of one glass lens and one plastic lens is manufactured. Next, this compound lens is set in another injection molding die and molded in the same manner as above to form a compound optical lens having a three-element structure.

In the case of a combination of one lens made of a thermosetting resin and two lenses made of a thermoplastic resin, first, a thermosetting resin is used to form a plastic lens by transfer molding, Similarly to the above, two plastic lenses are joined by two-step injection molding using a thermoplastic resin.

In the case of a combination of two lenses made of a thermosetting resin and one lens made of a thermoplastic resin, first, a thermosetting resin is used to form a plastic lens by transfer molding. Then, the compound lens is set in another transfer molding die and transfer molding is performed using a thermosetting resin to form a composite lens. Finally, the compound lens is set in a mold for injection molding and injection-molded using a thermoplastic resin to form a compound optical lens having a three-element structure.

In the case of a combination of a glass lens, a thermosetting resin and a thermoplastic resin, the optical glass is processed in the same manner as above to form a glass lens, which is set in a transfer molding die and heated. Fill with a curable resin to form a glass-thermoset resin composite lens. Next, this composite lens is set in an injection molding die, and similarly to the above, a composite optical lens having a three-piece structure is formed by injection molding using a thermoplastic resin.

[Third Embodiment] Next, a third embodiment according to the present invention will be described with reference to FIG. The third embodiment includes a convex lens 6 having a low refractive index and a concave lens 7 having a high refractive index,
The combination of the materials of these two lenses is a thermosetting resin and a thermoplastic resin, or thermoplastic resins. Also in this embodiment, one of the convex lens 6 and the concave lens 7 is formed in advance as an insert, and then the other is formed by insert molding. The third embodiment is manufactured by the same manufacturing method as the first embodiment. The combinations of materials of the convex lens 6 and the concave lens 7 in this embodiment are as shown in Table 4 below.

[0042]

[Table 4] Convex lens 6 Concave lens 7 13 PMMA PC 14 MH resin PC 15 PMMA AS 16 CR-39 PS 17 PMMA Sulfur containing urethane

In this embodiment, a convex portion 6a is formed on the convex lens 6 and a concave portion 7a corresponding to the convex portion 6a is formed on the concave lens 7 outside the optically effective diameter, and they are joined together. By joining the convex portion 6a and the concave portion 7a,
The adhesion between the convex lens 6 and the concave lens 7 is improved. As for the planar shape of the convex portion and the concave portion, a plurality of circular or angular shapes may be formed on the outer circumference of the optically effective diameter, or a ring shape may be formed on the outer circumference. This convex portion 6
By fitting a with the recess 7a, the joint area of both lenses is increased and a joint surface in a direction different from the joint direction is formed, so the adhesion force between both lenses is increased and the risk of peeling is reduced. To be done.

In addition to this structure, the cross-sectional shape of the convex portion 6a is formed so as to widen in the protruding direction as shown in the figure, and the concave portion 7a correspondingly widens in the depth direction. Is formed. Therefore, when this embodiment is formed by injection molding, whichever of the convex lens 6 and the concave lens 7 is molded as an insert, an undercut portion is formed during molding, and the two are prevented from peeling off during mold release. . Further, as described above, the durability of the manufactured composite optical lens can be improved, and peeling due to heat or impact can be prevented.

In the above embodiment, when the insert is formed by resin molding, the convex portion 6a or the concave portion 7a is formed.
Since there is an undercut portion when forming, the mold release is difficult. However, since these undercut portions are formed outside the optically effective diameter, they do not affect the optical surface even if they are forcibly removed.

[Fourth Embodiment] FIG. 4 shows a fourth embodiment according to the present invention.
Is shown. This embodiment comprises a three-lens structure of a convex lens 8 having a low refractive index and concave lenses 9 and 10 having a high refractive index. Recesses 8a are formed on the outer peripheral portions of the front and back surfaces of the convex lens 8, and the protrusions 9a corresponding to the recesses 8a,
10a is formed on the outer peripheral portion of the inner surfaces of the concave lenses 9 and 10. In this embodiment, one lens of thermosetting resin and two lenses of thermoplastic resin, two lenses of thermosetting resin and one lens of thermoplastic resin, or three lenses of thermoplastic resin are combined. It is preferable to manufacture. In addition, this embodiment is manufactured by the same manufacturing method as that of the second embodiment. The combinations of materials of the convex lens 8 and the concave lenses 9 and 10 of this embodiment are as shown in Table 5 below.

[0047]

[Table 5] Convex lens 8 Concave lens 9 Concave lens 10 18 MH resin PC AS 19 PMMA PC AS 20 MH resin PC PC 21 PMMA Sulfur-containing urethane PC 22 CR-39 Sulfur-containing urethane PC

In this embodiment, the concave portion 8a and the convex portions 9a, 1
Regarding the shape of the fitting portion consisting of 0a, the fitting surface A on the center side (optically effective diameter side) of the convex lens 8 is formed parallel to the mold release direction (horizontal direction in the figure) so that undercut does not occur. However, the fitting surface B on the outer peripheral side of the convex lens 8, that is, on the side opposite to the center, is formed to have an angle with respect to the releasing direction so as to form an undercut portion. In this case, the fitting surface A does not necessarily have to be horizontal, and may be inclined so as to open with respect to the mold release direction so that an undercut portion does not occur.

The fitting portion configured as described above can prevent peeling at the time of mold release as well as peeling after manufacturing similarly to the third embodiment, but different from the third embodiment.
The undercut portion formed in the fitting portion has little influence on the inner side of the optical effective diameter when the convex lens 8 is molded, and deforms only the outer peripheral side. That is, since no undercut is formed on the fitting surface A, when the protrusion or the recess is forcibly removed during molding of the insert, stress is not applied to the center side of the protrusion or the recess of the insert.
There is no fear of deformation. On the other hand, since an undercut is formed on the fitting surface B, deformation due to forcible removal occurs on the outer peripheral side of the convex portion or concave portion of the insert, but this does not spread to the center side of the insert. Therefore, it is possible to configure a highly accurate optical lens, and it is not necessary to provide a large convex portion or concave portion forming region outside the optical effective diameter in order to avoid the influence of such deformation due to forced removal. The optical effective diameter of the lens can be made relatively large.

[Embodiment 5] FIGS. 5 and 6 show a composite optical lens of Embodiment 5 according to the present invention, which has a two-element construction. What is shown in FIG. 5 is a convex lens 11 having a low refractive index,
It is a combination of two lenses with a concave lens 12 having a high refractive index. In this combination, the convex lens 11 is made of optical glass, a thermosetting resin or a thermoplastic resin, and the concave lens 12 is made of a thermoplastic resin. This compound optical lens is manufactured by the same method as the manufacturing method of the first embodiment. The combinations of materials of the convex lens 11 and the concave lens 12 are as shown in Table 6 below.

[0051]

[Table 6] Convex lens 11 Concave lens 12 23 FK01 PC 24 MH resin PC 25 MH resin AS 26 CR-39 PC

In this embodiment, an outer peripheral coating portion 12a for coating the outer periphery of the convex lens 11 is formed on the outer peripheral portion of the concave lens 12 made of a thermoplastic resin, and the refraction opposite to the joint surface of the convex lens 11 is performed. An outer frame portion 12b extending to the outer edge of the surface is also formed. By extending the peripheral portion of the concave lens 12 so as to include the outer peripheral covering portion 12a and the outer frame portion 12b, the adhesive force between the two lenses is increased, and peeling between the two lenses during mold release and after manufacturing is prevented. To be done. Here, the outer frame portion 12b is limited to the outside of the lens effective diameter.

FIG. 6 shows a compound optical lens having a two-element structure consisting of a convex lens 13 having a low refractive index and a concave lens 14 having a high refractive index, but unlike the one shown in FIG. 5, the convex lens 13 is different. The outer peripheral covering portion 13a and the outer frame portion 13
b is formed. In this case, the convex lens 13 is made of thermoplastic resin, and the concave lens 14 is made of optical glass, thermosetting resin or thermoplastic resin. The manufacturing method is performed in the same manner as in Example 1. The combinations of materials of the convex lens 13 and the concave lens 14 are as shown in Table 7 below.

[0054]

Table 7 Convex lens 13 Concave lens 14 27 PMMA SF2 28 MH resin Sulfur containing urethane 29 PMMA PC

Also in the case shown in FIG. 6, the separation of both lenses is prevented as in the above case. In the embodiment shown in FIGS. 5 and 6, the outer peripheral coating portion and the outer frame portion are formed over the entire circumference of the outer edge of the other lens, but the outer peripheral coating portion and the outer frame portion are formed only on a part of the outer edge of the other lens. The outer frame portion may be formed.

[Sixth Embodiment] FIG. 7 shows a sixth embodiment according to the present invention.
Is shown. Example 6 is a composite optical lens having a three-lens structure including a convex lens 15 having a low refractive index and concave lenses 16A and 16B having a high refractive index formed on both front and back surfaces thereof. The convex lens 15 is made of a thermosetting resin or a thermoplastic resin, and the concave lenses 16A and 16B are made of a thermosetting resin or a thermoplastic resin of the same material. However, in this case, the convex lens 15 and the concave lens 16
In combination with, the combination of thermosetting resins is not preferable. These convex lens 15 and concave lens 1
The combinations of materials of 6A and 16B are as shown in Table 8 below.

[0057]

[Table 8] Convex lens 15 Concave lens 16 (16A, 16B) 30 PMMA PC 31 MH resin PC 32 PMMA AS 33 CR-39 PS 34 MH resin Sulfur containing urethane

In this embodiment, a plurality of through holes 15a are formed outside the lens effective diameter of the convex lens 15, and the concave lenses 16A and 16B are connected by the communicating portion 16a through the through holes 15a to form an integral resin. It constitutes the layer 16. Therefore, since these three lenses closely adhere to each other as if they were formed almost integrally, there is no fear of peeling.

The manufacturing method of this embodiment is as follows. (When the convex lens is made of thermosetting resin and the concave lens is made of thermoplastic resin) In this case, the convex lens 15 having the through hole 15a is manufactured by transfer molding of thermosetting resin, and The concave lenses 16A and 16B are set by setting in an injection molding die, injecting a thermoplastic resin as in the first embodiment, and performing insert molding.

(When the convex lens is made of a thermoplastic resin and the concave lens is made of a thermosetting resin) In this case, the convex lens 15 is formed by injection molding of a thermoplastic resin, and this is used for transfer molding. Set in the mold and mold. At this time, it is necessary to select the materials of both lenses in consideration of the heat resistant temperature of the thermoplastic resin so that the thermoplastic resin of the convex lens 15 is not deformed or deteriorated by the heat received during the transfer molding.

(When both the convex lens and the concave lens are made of thermoplastic resin) The convex lens 15 is formed by injection molding, set in another injection molding die, and the concave lenses 16A, 16B on the front and back are formed by insert molding. Form.

[Seventh Embodiment] FIG. 8 shows the structure of a seventh embodiment according to the present invention. Example 7 is a compound optical lens having a three-element configuration, and has a convex lens 17 having a low refractive index.
And the concave lenses 18A and 18B having a high refractive index, and the concave lenses 18A and 18B are made of the same material. In this embodiment, the concave lenses 18A and 18B are composed of an integral coating layer 18 having an outer peripheral coating 18a that covers the outer periphery of the convex lens 17, and the convex lens 17 is completely covered by the concave lenses 18A and 18B. The three lenses are in close contact with each other and there is no risk of peeling.

The convex lens 17 is made of optical glass, thermosetting resin or thermoplastic resin, and the concave lens 18A, 18B is formed.
Is formed of a thermosetting resin or a thermoplastic resin. Table 9 below shows combinations of materials of the convex lens 17 and the concave lenses 18A and 18B in this embodiment.

[0064]

[Table 9] Convex lens 17 Concave lens 18 (18A, 18B) 35 BK7 PC 36 FK01 PC 37 PMMA PC 38 MH resin PC 39 CR-39 PC 40 FK01 AS 41 PMMA AS 42 MH resin AS 43 CR-39 B 7 PS 44 PMMA PS 46 MH resin PS 47 CR-39 PS 48 MH resin Sulfur containing urethane

The manufacturing method of this embodiment is performed by the same method as the manufacturing method of the sixth embodiment. However, in the case where the convex lens 17 is made of optical glass and the concave lenses 18A and 18B are made of thermoplastic resin, the optical glass is processed by a well-known method, and this is set in an injection-molding die to set thermoplasticity. Mold by injection of resin. When the convex lens is made of a thermoplastic resin and the concave lens is made of a thermosetting resin as in Example 6, the same material selection as above is performed so as not to cause deformation or deterioration of the thermoplastic resin. Take note of the above.

In each of the embodiments described above, a combination of a convex lens having a low refractive index and a concave lens having a high refractive index is shown. However, in the present invention, not only a combination of a convex lens having a high refractive index and a concave lens having a low refractive index is used. ,
It can also be applied to other complex optical lenses that combine a high refractive index and a low refractive index.

Further, although each of the above-mentioned embodiments shows a compound lens having a two-lens structure and a three-lens structure, it is also clear that the present invention can be applied to a compound lens having four or more lenses. Furthermore, other treatments such as surface coating may be added to the above-mentioned compound lens, and in this case also, it belongs to the category of the present invention.

Finally, an example of the structure of an injection molding die suitable for use in the manufacture of the embodiment including the step of forming by insert molding among the above embodiments will be described with reference to FIGS. 9 and 10. . As shown in FIG. 9, a fixed die plate 102 is attached to a fixed die plate 101 of the molding machine, and a fixed core 103 is fixed in the fixed die plate 102. A mounting plate 104 and a drive plate 105 are slidably housed in the stationary core 103 in the mold opening direction.
04 and the drive plate 105, a plurality of support pins 10 between them.
7 and the pressure receiving pin 108 are sandwiched and fixed to each other. An elastic spring 106 is held in a compressed state between the drive plate 105 and the fixed die plate 101.

A movable side mold plate 202 is attached to the movable side die plate 201, and a movable side core 203 is fixed inside the movable side mold plate 202. Movable core 203
A mounting plate 204 and a drive plate 205 are slidably housed inside the mold, and a plurality of support pins 207 and pressure receiving pins 208 are provided between the mounting plate 204 and the drive plate 205.
Are clamped to each other and fixed to each other. Drive plate 20
5 between the movable die plate 201 and the movable die plate 20.
6 is held in a compressed state. Movable die plate 2
A projecting rod 209 is formed so as to be retractable through a through hole provided at 01, and the tip of the projecting rod 209 is arranged so as to be able to press the drive plate 205.

Resin supplied from an injection nozzle (not shown) is introduced from the gate 303 through the introduction holes 301 and 302,
It is injected into the cavity 304 formed by the contact surfaces of the fixed core 103 and the movable core 203. Introduction hole 30
The pressure receiving surface formed at the tip of the pressure receiving pins 108 and 208 faces 1. Usually, the elastic springs 106, 20
By the elastic force of 6, the support pin 10 is inserted in the cavity 304.
When the core lens body C, which is an insert, is introduced into a state of being supported by the support pin 107 and the mold is closed, as shown in FIG. 9, the elastic spring 106 of a larger size is set. The position of the support pin 107 is held by the elastic coefficient, and the elastic spring 206 having an elastic coefficient smaller than that of the elastic spring 106 is slightly compressed and the support pin 207 is retracted to some extent. In this way, the core lens body C is sandwiched by the support pins 107 and 207 by the elastic force.

When the resin is introduced from the introduction hole 301 in this state, as shown in FIG. 10, the resin is injected from the gate 303 into the cavity 304 to fill the periphery of the core lens body C, and Since the pressure receiving surface facing the introduction hole 301 is pressed by the injection pressure, the pressure receiving pins 108 and 208 retreat, and the drive plates 105 and 205 retreat against the elasticity of the elastic springs 106 and 206. 207 is retracted from the cavity 304. In this way, the resin is hardened in the cavity 304 with the core lens body C floating in the center, and a convex lens is inserted as in the above-mentioned Embodiment 2, Embodiment 4, Embodiment 6 and Embodiment 7. As a result, even when concave lenses are formed on both front and back surfaces, molding can be performed without any trouble.

Generally, the resin injection pressure is the cavity 304.
Since the temperature rises as the resin is injected into the inside, the pressure receiving areas of the pressure receiving pins 108 and 208 and the maximum pressure of the resin are set so that the support pins retract when almost all of the periphery of the core lens body C is filled with the resin. , And the elastic coefficients of the elastic springs 106 and 206 are mutually considered and designed.

Finally, when the resin in the cavity 304 is cured, the fixed side mold plate 102 and the movable side mold plate 202 are opened, and the projecting rod 209 projects the drive plate 205, so that the support pin and the pressure receiving pin are molded. Stick out.
Here, the protrusion of the molded product may be performed by a drive plate and a protrusion pin which are separately provided.

As described above, since the support pin is automatically retracted by the resin pressure, the entire periphery can be covered without leaving the tip shape of the support pin in the molded product. However, as shown in the above embodiment, the support pin is usually arranged so as to abut on the outside of the optical effective diameter of the core lens body C. Therefore, the support pin is molded in the protruding state without protruding and retracting. It doesn't matter. When the support pin is brought into contact with the surface of the flat plate portion formed on the outer side of the optical effective diameter as described above, the tip surface of the support pin may be a flat surface, but a curved surface of the core lens body such as a convex surface or a concave surface. When the support pin is brought into contact with the top of the support pin, it is desirable that the tip end surface of the support pin is also formed into a curved surface. In particular,
By forming on the support pin a tip end surface that matches the outer surface of the molded product, the tip end surface of the retracted support pin is changed to the cavity 3
Since it can be configured so as to be continuous with the inner surface of 04, it is necessary to form the core lens body so as to leave almost no trace of the support pin even if the core lens body is not provided with a surface portion for contacting the support pin. You can

[0075]

As described above, the present invention has the following effects. According to the first aspect, at least one lens body of the composite optical lens is formed by injection molding with a synthetic resin, so that the resin can be easily handled and managed, and a desired shape, hardness, and performance can be relatively easily obtained. Since it can be realized and the molding can be performed quickly and easily, the manufacturing cost can be reduced.

According to the second aspect, by manufacturing by insert molding using another lens body as an insert,
The resin has a relatively high adhesiveness and can be manufactured with high molding efficiency. In this case, insert molding is preferably performed by supporting the insert with a support member such as a support pin protruding from the cavity, and in particular, the support member is retracted from the inside of the cavity after resin injection and before curing. desirable. Further, it is preferable that the withdrawal of the support member is performed in conjunction with the pressure of the injected resin, and it is effective that the tip end surface of the support member is aligned with the inner surface of the cavity.

According to the third aspect of the present invention, since the concave and convex portions which become the undercut portions at the time of mold release of the injection molding are formed on the joint surface of both lens bodies, the adhesion force between both lens bodies can be enhanced, so that peeling can be achieved. It is possible to reduce the risk of

According to the present invention, the uneven portion is provided with the non-undercut surface formed on the center side of the lens body and the undercut surface formed on the anti-center side of the lens body. Since stress is prevented from being applied to the center side of the lens body at the time of mold release, it is possible to prevent deformation of the center portion of the lens body.

According to the fifth aspect, the lens body is extended from the joint surface with the other lens body to cover the outer circumference of the other lens body, and further, it is provided on the side opposite to the joint surface of the other lens body. By forming it so as to extend to the outer edge portion of the surface, the adhesion of both lens bodies can be increased, and therefore the risk of peeling can be reduced.

According to the sixth aspect, the lens bodies are formed on both the front surface and the back surface of the other lens body, and the front surface side lens body and the back surface side lens body are formed on the other lens body. By integrally connecting through the penetrating portion, the adhesion between both lens bodies can be increased, and therefore the risk of peeling can be almost eliminated.

According to the seventh aspect, the lens bodies are formed on both the front surface and the back surface of the other lens body, and the lens body on the front surface side and the lens body on the back surface side are formed on the outer circumference of the other lens body. By integrally connecting with the outer peripheral covering portion that covers the lens, the adhesion of both lens bodies can be increased, and therefore the risk of peeling can be almost eliminated.

[Brief description of drawings]

FIG. 1 is a sectional view showing the structure of Example 1 of the compound optical lens according to the present invention.

FIG. 2 is a sectional view showing the structure of Example 2 of the compound optical lens according to the present invention.

FIG. 3 is a sectional view showing the structure of Example 3 of the complex optical lens according to the present invention.

FIG. 4 is a sectional view showing the structure of Example 4 of the complex optical lens according to the present invention.

FIG. 5 is a sectional view showing the structure of Example 5 of the complex optical lens according to the present invention.

FIG. 6 is a sectional view showing another structure of Example 5 of the compound optical lens according to the present invention.

FIG. 7 is a cross-sectional view showing the structure of Example 6 of the complex optical lens according to the present invention.

FIG. 8 is a sectional view showing the structure of Example 7 of the complex optical lens according to the present invention.

FIG. 9 is a cross-sectional view showing the structure of an injection molding die suitable for the manufacturing process of the above embodiment.

FIG. 10 is a cross-sectional view showing a state of the injection molding die shown in FIG. 9 during molding.

[Explanation of symbols]

1,3,6,8,11,13,15,17 Convex lens 2,4,5,7,9,10,12,14,16A, 16
B, 18A, 18B concave lens 6a, 9a, 10a convex part 7a, 8a concave part 12a, 13a, 18a outer peripheral covering part 12b, 13b outer frame part A, B mating surface

Claims (7)

[Claims] 1. A composite optical lens having a lens body having a predetermined optical surface and another lens body joined to the lens body, wherein at least one of the lens bodies is formed by injection molding using a synthetic resin. Complex optical lens formed. 2. The composite optical lens according to claim 1, wherein the lens body is formed by insert molding using another lens body as an insert. 3. The concavo-convex portion which is an undercut portion at the time of releasing the injection molding is formed on a joint surface between the lens body and the other lens body. Compound optical lens. 4. The uneven portion according to claim 3, wherein the uneven portion has a non-undercut surface formed on a center side of the lens body and an undercut surface formed on an opposite center side of the lens body. Is a compound optical lens. 5. The lens body according to claim 1, wherein the lens body extends from a joint surface with the other lens body to cover an outer periphery of the other lens body, and further, the joint surface of the other lens body. A compound optical lens characterized in that it extends to the outer edge of the surface opposite to. 6. The lens body according to claim 1, wherein the lens body is formed on each of a front surface and a back surface of the other lens body, and the lens body on the front surface side and the lens body on the back surface side are different from each other. A compound optical lens, wherein the compound optical lens is integrally connected through a penetrating portion formed in the lens body. 7. The lens body according to claim 1, wherein the lens body is formed on each of the front surface and the back surface of the other lens body, and the lens body on the front surface side and the lens body on the back surface side are different from each other. A compound optical lens, characterized in that they are integrally connected by an outer peripheral coating portion that covers the outer periphery of the lens body.