JPH0529717U - Mold for plastic lens molding - Google Patents

Abstract

(57) [Abstract] [Purpose] Keeping the core of the assembly part to the optical core highly
And, a mold for molding a plastic lens which can be manufactured relatively easily is obtained. [Structure] The mold 1 includes a movable mold plate 2 and a fixed mold plate 3. The movable mold plate 2 is provided with a movable sleeve 4, a movable insert 5, and an ejector pin 6. The fixed mold plate 3 is provided with a fixed sleeve 7 and a fixed insert 8. A taper 11 and a non-taper 13 are formed on the movable optical surface 9 of the movable insert 5.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a mold for molding a plastic lens.

[0002]

[Prior Art]

 Injection-molded plastic lenses have the characteristic that they can be manufactured at a lower cost than glass lenses made by polishing, and that aspherical surfaces, which are difficult to make by glass polishing, can be made relatively easily. There is.

However, the precision of each part of the plastic lens is harder to obtain than that of the glass lens, and the accuracy of matching (eccentricity) of the outer diameter (assembly part) core to the optical core cannot be sufficiently accurate in the related art. It was Particularly in the case of a lens having an aspherical surface, excellent optical performance can be obtained if the decentering is sufficiently small, but if the decentering is large, the optical performance may be extremely deteriorated.

The following methods are known to solve the above-mentioned drawbacks. One is the method of adjusting the core when the plastic lens is installed in the frame. As another method, for example, in the invention described in JP-A-64-57430, as shown in FIG. 12, in order to increase the eccentricity accuracy of the mold, the fixed side insert 81, the movable side insert 82, and the movable side sleeve are provided. A method for improving the machining accuracy and assembling accuracy in 83 etc. has been proposed.

[0005]

[Problems to be solved by the device]

 However, the above-mentioned prior art has the following drawbacks. In other words, the method of adjusting the core when incorporating the plastic lens into the frame requires man-hours for adjustment and is not preferable in terms of cost.

Further, in the invention described in the above-mentioned Japanese Patent Laid-Open No. 64-57430, improving the processing and assembling accuracy causes a cost increase. Further, as shown in FIG. The accuracy errors of the parts are accumulated, and it is not always possible to obtain satisfactory accuracy. A method in which the movable-side insert 82 and the movable-side sleeve 83 are made into an integral part may be considered, but this is difficult in terms of processing the optical surface. Further, since the roundness of the outer diameter portion of the molded plastic lens is often deteriorated in general, the core of the outer diameter portion 84 of the fixed side insert 81, the movable side insert 82, and the movable side sleeve 83 is temporarily assumed. Even if they match well, the optical core of the molded plastic lens and the outer diameter core do not always match.

Therefore, the present invention was developed in view of the above-mentioned drawbacks of the prior art. For molding a plastic lens, the core of the assembly portion with respect to the optical core can be maintained with high accuracy and can be manufactured relatively easily. The purpose is to provide the type of.

[0008]

[Means for Solving the Problems]

 The present invention relates to a mold for molding a plastic lens in which three or more assembling parts for assembling are provided outside the optically effective surface, in a mold for molding the optical surface of the plastic lens and a mold for molding the assembling part. And are integrated.

[0009]

[Action]

 Since the optical surface of the plastic lens molded by the mold of the present invention and the assembling part for assembly are formed as a single insert, the relative position of both can be maintained with high accuracy.

[0010]

Embodiment 1 FIGS. 1 to 4 show the present embodiment, FIG. 1 is a sectional view of a main part of a mold, FIG. 2 is a front view of a molded plastic lens, and FIG. 3 is a vertical section of a molded plastic lens. FIG. 4 is a vertical sectional view showing an assembled state.

Reference numeral 1 denotes a mold, which is composed of a movable side mold plate 2 and a fixed side mold plate 3. A movable side sleeve 4 is attached to the movable side template 2, a movable side insert 5 is provided inside the movable side sleeve 4, and an ejector pin 6 for taking out a molded product is provided inside. A stationary sleeve 7 is attached to the stationary template 3, and a stationary insert 8 is provided in the stationary sleeve 7.

A taper 11 forming a taper portion 10 and a non-taper 13 forming an assembly portion 12 are formed outside the optically effective surface of the movable side optical surface 9 of the movable side insert 5. The pars 13 are provided at three places at equal intervals. The runner 14 is connected to the cavity 16 via the gate 15.

A taper portion 10 and an assembling portion 12 are formed on the inner periphery of the collar 18 of the plastic lens 17 molded by the mold 1 having the above-described structure. Since the assembled part 12 of the molded plastic lens 17 is formed by the movable side insert 5 which is the same as the movable side optical surface 9, the plastic lens 17 in which the relative positions of the two are kept with high precision is molded. .. (See FIG. 2 and FIG. 3.)

Then, the glass lens 20 is inserted into the inner circumference of the collar 18. Then, the outer circumferences of the plastic lens 17 and the glass lens 20 are in contact with each other at the mounting portion 12. In this state, the plastic lens 17 and the glass lens 20 are fixed by means of adhesion or the like to complete the assembly of both.

According to the present embodiment, both the assembly portion 12 that contacts the glass lens 20 and the movable-side optical surface 9 are formed by the movable-side insert 5, so that the inscribed circles ( That is, the core between the glass lens 20) and the movable side optical surface 9 can be maintained with high accuracy. If the roundness of the brim 18 is poor and the cores between the inscribed circles of the three mounting parts 12 and the movable side optical surface 9 cannot be obtained with sufficient accuracy, the plastic lens 17 will come out. By removing the non-taper 13 of the movable side insert 5 in accordance with the above, it is possible to adjust the cores of the inscribed circles of the three assembly parts 12 and the movable side optical surface 9.

Further, since the taper portion 10 (taper 11) is provided except for the assembling portion 12 (non-taper 13) that is in contact with the glass lens 20, when the molded product (plastic lens 17) is taken out from the mold after molding, it is separated. The mold resistance can be reduced, and the surface accuracy of the plastic lens 17 can be kept high. Further, since the tang 18 protrudes from the optical surface of the plastic lens 17, the optical surface is protected.

Although the assembling parts 4 are provided at three places in this embodiment, the present invention is not limited to this, and the attaching parts 12 may be provided at any number of three or more places. Further, the assembling portion or the assembling protrusion is not limited to the movable side only, and may be provided on the fixed side or both sides of the movable side and the fixed side. Further, the insert forming the assembly portion or the assembly projection does not have to be the same member as the insert forming the optical surface, and means for welding, bonding, screwing, etc. even if they are separate members. It should be integrated by.

[0018]

Embodiment 2 FIGS. 5 to 8 show the present embodiment, FIG. 5 is a sectional view of a main part of a mold, FIG. 6 is a front view of a molded plastic lens, and FIG. 7 is a vertical section of a molded plastic lens. FIG. 8 is a vertical sectional view showing an assembled state.

The present embodiment is different in that the movable side optical surface 9 of the movable side insert 5 in the first embodiment is provided with a hole, and the other components are the same components. Are assigned the same numbers and their explanations are omitted.

Reference numeral 21 is a mold, and three holes 25 are formed at equal intervals outside the optically effective surface of the movable optical surface 23 of the movable insert 22 of the mold 21 to form protrusions 24. Ejector pins 26a and 26b are provided inside the movable insert 22. The movable side optical surface 23 is formed into a concave or flat surface.

Three protrusions 24 for assembly are formed at equal intervals on the outside of the optically effective surface of the plastic lens 27 molded by the mold 21 having the above configuration. The lens surface on the side where the protrusion 24 is provided is convex or flat. (See FIG. 6 and FIG. 7.) Since the protrusion 24 is formed by the movable-side insert 22 that is the same as the movable-side optical surface 23, a plastic lens 27 in which the relative positions of the two are maintained with high precision is molded. ..

The protrusions 24 of the plastic lens 27 are inserted into the inner circumference of the frame 28 formed to have a diameter substantially equal to the circumscribing circle of the protrusions 24 at three locations. Then, the plastic lens 27 and the frame 28 are in contact with each other by the protrusion 24. In this state, by assembling the plastic lens 27 and the frame 28 by means of adhesion or the like, the assembly of both is completed.

According to the present embodiment, the core between the circumscribing circle (that is, the frame 28) of the projections 24 at three places and the movable side optical surface 23 can be maintained with high accuracy in the same manner as in the first embodiment. Moreover, the protrusion 24 protects the optical surface.

Although the projections 24 are provided at three locations in this embodiment, the present invention is not limited to this, and the projections 24 may be provided at any number of locations of three or more. Further, instead of assembling to the frame 28 on the outer periphery of the protrusion 24, it may be assembled to the frame 28 on the inner periphery of the protrusion 24.

9 to 11 show modified examples of this embodiment. FIG. 9 is a sectional view of the main part of the mold, FIG. 10 is a front view of the molded plastic lens, and FIG. 11 is a vertical sectional view of the molded plastic lens.

Reference numeral 31 denotes a mold of the above modification, in which the movable optical surface 33 of the movable insert 32 of the mold 31 is formed in a convex shape, and the biconcave lens 34 is molded. Even if the member forming the movable-side optical surface (movable-side insert 32) and the member forming the collar 35 are separate bodies, the movable-side optical surface 33 and the projection 24 are the same member (movable-side insert). Since it is formed in 32), the relative position of the two is maintained with high accuracy. According to the mold 31 of the modified example, even if the optical surface on the side where the projection for assembly is to be provided is a concave surface (convex surface in the mold insert), the mold insert can be processed relatively easily. ..

[0027]

[Effect of the device]

 As described above, according to the mold for molding a plastic lens according to the present invention, a mold for molding a plastic lens is obtained which can maintain the assembly core for the optical core with high accuracy and can be manufactured relatively easily. be able to.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of a first embodiment.

2 is a front view of the molded plastic lens of Example 1. FIG.

3 is a vertical cross-sectional view of the molded plastic lens of Example 1. FIG.

FIG. 4 is a vertical sectional view showing an assembled state of the first embodiment.

FIG. 5 is a sectional view of a main part of the second embodiment.

6 is a front view of the molded plastic lens of Example 2. FIG.

7 is a vertical sectional view of a molded plastic lens of Example 2. FIG.

FIG. 8 is a vertical sectional view showing an assembled state of the second embodiment.

FIG. 9 is a cross-sectional view of a main part showing a modified example of the second embodiment.

10 is a front view of a molded plastic lens showing a modified example of Example 2. FIG.

FIG. 11 is a vertical sectional view of a molded plastic lens showing a modified example of the second embodiment.

FIG. 12 is a cross-sectional view of a main part showing a conventional example.

[Explanation of symbols]

 1 type 2 movable side template 3 fixed side template 4 movable side sleeve 5 movable side insert 6 ejector pin 7 fixed side sleeve 8 fixed side insert 9 movable side optical surface 11 taper 13 non-taper

Claims (1)

[Scope of utility model registration request] 1. A mold for molding a plastic lens in which three or more assembling parts for assembly are provided outside the optically effective surface, and a mold for molding the optical surface of the plastic lens and a mold for molding the assembling part. A mold for molding plastic lenses, characterized by being integrated with a child.