JP2603516Y2 - Jig for plastic lens production - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic lens manufacturing jig used in a plastic lens manufacturing process, particularly, an annealing process.

[0002]

2. Description of the Related Art In the production of plastic lenses,
Preventing the occurrence of internal distortion is a major issue. This internal distortion is caused by cooling when it is cooled and solidified after injection molding in the injection molding, and causes lens aberration. Therefore, conventionally, in order to prevent the occurrence of internal distortion, cooling has been performed for a long time (about 20 minutes to 1 hour) in the molding die after injection molding, or immediately after being taken out of the molding die after the molding, and annealed. However, long-time cooling in a molding die has a disadvantage that productivity is low. On the other hand, the annealing treatment is a method in which the plastic lens after polymerization is immediately taken out of the mold and heated again to remove internal strain. When the annealing treatment is completed, the lens molding step is completed and sent to the inspection step.

[0003] In this annealing method, in the casting polymerization method, a released plastic lens is placed on a flat plate or a net-like plate with the convex surface facing upward and the lens is heated while maintaining the stability of the lens. Was. In the case of an injection-molded plastic lens, for example, Japanese Patent Laid-Open No.
As disclosed in JP-A-115321, a method is disclosed in which a plastic lens is immersed in hot water of 70 ° C. or higher for a required time using a hollow lens holder that covers and holds the peripheral portion of the lens, and is gradually cooled. . In such a lens holder, since heat radiation from the peripheral portion can be suppressed,
In the manufacture of the convex lens, there is an advantage that the lens peripheral portion and the central portion having different thicknesses can be uniformly cooled.

[0004]

However, in the lens holder disclosed in Japanese Patent Laid-Open Publication No. 57-115321, a pair of peripheral portions formed in a ring shape and whose outer peripheries are connected to each other by hinges. Since it is necessary to clamp the peripheral edge of the lens with the cover, one holder is required for one lens, and the number of holders is increased, and the operation of attaching and detaching the lens is troublesome, resulting in poor handling. There was a problem. Further, in the case of a lens having a toric surface such as an astigmatic lens, and particularly in the case of a deep toric curve, it is difficult to hold the lens because the lens peripheral thickness is not constant. Furthermore, in the case of a lens having a low glass transition point, such as a polyurethane-based lens, the instability of the holding state has a problem that the deformation and optical distortion of the lens are promoted by heating during annealing.

The present invention has been made in view of the above-mentioned conventional problems, and has as its object the purpose of simple and easy operation of attaching / detaching a lens, excellent handleability, and the fact that the lens is slightly It is an object of the present invention to provide a jig for manufacturing a plastic lens which can cope with deformation and contraction and can stably support a lens having a low glass transition point.

[0006]

In order to achieve the above object, a plastic lens manufacturing jig according to the present invention is a jig used for manufacturing a plastic lens, and this jig is opened up and down. At least two lens mounting portions formed on the inner surface of the cylindrical body and provided on the inner peripheral surface in the axial direction and having an upper side larger than a lower side, and these lens mounting portions are reduced in diameter toward the lower side to have a plastic lens. Each of the jigs has a tapered lens mounting surface that supports an outer peripheral edge, and one end of the jig is open to an upper end opening of the jig and the other end is the same as the lowermost lens mounting portion. At least one lens removal concave portion is provided at the height position or below and communicates the inside and outside of the jig, and the height from the lower end side opening surface of the jig to the lowermost lens mounting portion is On the lens mounting part When Las tic lens is placed in the convex surface to the bottom, in which the lens convex surface is set at a height not protruding from the lower end opening surface.

[0007]

In the present invention, the lens mounting portion having the tapered lens mounting surface supports the lower surface of the peripheral portion of the plastic lens. The lens removal recess allows removal of the plastic lens by a finger.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings. FIG. 1 is an external perspective view showing an embodiment of a jig for manufacturing a plastic lens according to the present invention, and FIG. 2 is a sectional view of the jig. In these figures, 1 is a jig for manufacturing a plastic lens (hereinafter referred to as a jig), 2 is a base on which the jig 1 is installed, and 3A and 3B are placed in the jig 1 with their convex surfaces facing downward. The lenses are inserted sequentially from the one with the smaller outer diameter.

The jig 1 is a lens 3A that has been released from a molding die after casting polymerization (including injection molding, injection compression molding, pressure molding, etc.) in the manufacturing process of plastic spectacle lenses. , 3B, which is used in an annealing process for removing optical distortion, and is opened vertically by a light metal such as an aluminum alloy so that the upper end opening 1a becomes the lower end opening 1a.
It is formed in a cylindrical body larger than b. The dimensions of the jig 1 are, for example, outer diameter D = 86 mmφ, upper end side opening diameter D
1 = 81 mmφ, and the lower end side opening diameter D2 = 69 mmφ. In the center of the inner peripheral surface of the jig 1, two large and small lenses 3A,
Two lens mounting portions 4 and 5 each supporting 3B are provided apart from each other in the axial direction. The outer diameters of the lenses 3A and 3B are, for example, 80 mmφ and 75 mmφ. The upper lens mounting portion 4 has a tapered lens mounting surface 6 which is reduced in diameter downward and is inclined at an appropriate angle to support the lower surface of the outer peripheral edge of the lens 3A.
The maximum diameter of the lens mounting surface 6 is the upper end side opening diameter D1.
And the minimum diameter is set smaller than the outer diameter of the lens 3A. The lens mounting portion 5 located below has a tapered lens mounting surface 7 which also has a diameter reduced downward and supports the lower surface of the outer peripheral edge of the lens 3B. The maximum diameter of the lens mounting surface 7 is equal to the minimum diameter of the lens mounting surface 6, and the minimum diameter is equal to the lower end side opening diameter D2. When the lens 3B is inserted into the jig 1 with the convex surface facing down and mounted on the lens mounting surface 7, the lower lens mounting portion 5 has the lower end opening 1b of the jig 1. The jig 1 is formed at a predetermined height from the lower surface of the jig 1 so as not to protrude from the jig 1. Further, four jigs 8 are formed in the peripheral wall of the jig 1 so as to be equally arranged in the circumferential direction. The lens extraction recess 8 is formed by a notch groove in the axial direction formed downward from the upper end surface of the jig 1, thereby communicating the inside and the outside of the jig 1. The concave portion 8 for taking out the lens has a groove width enough to allow a finger to enter, and is formed so that the lower end reaches the lower lens mounting portion 5. The jig 1 having such a configuration is used for annealing the lenses 3A and 3A during annealing.
B can be supported. The bottom surface 9 of the jig 1 is a flat surface, so that the jig 1 can maintain the levelness with the base 2. Further, a corner portion of the jig 1 is subjected to thread chamfering.

(Molding of Lenses 3A and 3B) As a polyurethane lens monomer, 484 parts by weight of m-xylene diisocyanate, 305 parts by weight of pentaerythritol tetrakis 3-mercaptopropionate, 90 parts by weight of monothioglycerol, and 0.1 part of dibutyltin diurarate. 3 parts by weight As a UV absorber, 0.5 parts by weight of 2- (2'-hydroxy-5'-t-octylphenyl) benzotriazole were mixed and sufficiently stirred, and then 1 mmH
Degassed under vacuum of 60 g for 60 minutes. Next, the spherical power-
3.00 ヂ optry (D), astigmatic power -1.00 ヂ optry (D), lens outer diameter 80 mmφ, center thickness 1.
To obtain a prescription lens of 8 mm, a lens mold made of upper and lower glass is prepared, a lens mold is assembled with a resin gasket, and the mixed solution is poured into the mold.
The temperature was continuously raised to 0 ° C over 20 hours, and further increased by 12 hours.
The polymerization was carried out at 0 ° C. for 2 hours. The gasket was removed, a wedge was driven between the lower mold and the molded lens to separate them, and the upper mold was peeled from the lens to take out the polyurethane lens.

(Annealing Step) Next, the lens obtained in the releasing step was inserted and arranged in a jig 1 and annealed at 60 ° C. to 120 ° C. FIG. 2 shows a state where the lenses 3A and 3B are housed in the jig 1 with their convex surfaces facing down. The two lenses 3A and 3B are housed in a non-contact manner and supported by the lens mounting surfaces 6 and 7. .

In the above embodiment, the jig 1 is made of an aluminum alloy. However, the present invention is not limited to this, and the light weight and heat resistance in a predetermined temperature range are considered. Plastics, ceramics, metals other than aluminum and the like may be used as long as they are made. Further, in this embodiment, two lens mounting portions 4 and 5 are provided, but two or more lens mounting portions may be provided. Further, the number of the concave portions 8 for taking out the lens may be any number as long as one or more can hold the lens sufficiently. In addition, lens holding is not two pieces at a time,
Of course, one sheet may be used.

[0013]

As described above, the jig for manufacturing a plastic lens according to the present invention comprises a cylindrical body, and at least two lens mounting portions are provided on the inner peripheral surface thereof in the axial direction.
A plastic lens is inserted from the upper end opening and its peripheral edge is supported by the lens mounting portion, and a concave portion for taking out the lens is formed in the peripheral wall, so that the structure is simple and the plastic lens mounting and demounting operation is quick and easy. It can be carried out. In addition, since the lens mounting portion has a tapered lens mounting surface, it can cope with slight deformation or contraction of the lens during annealing, and stably supports a polyurethane lens having a low glass transition point. be able to. Further, in the present invention, a plurality of lenses can be supported by one jig, and the number of jigs can be reduced, so that the practical effect is great.

[Brief description of the drawings]

FIG. 1 is an external perspective view showing one embodiment of a jig for manufacturing a plastic lens according to the present invention.

FIG. 2 is a sectional view of the jig.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Jig 2 Base 3A lens 3B lens 4 Lens mounting part 5 Lens mounting part 6 Lens mounting surface 7 Lens mounting surface 8 Lens taking-out recess

Claims (1)

(57) [Scope of request for utility model registration] 1. A jig used for manufacturing a plastic lens, wherein the jig is formed in a cylindrical body which is opened up and down, and an upper side provided on an inner circumferential surface in an axial direction is lower than a lower side. At least two large lens mounting portions, each of which has a tapered lens mounting surface that is reduced in diameter downward and supports an outer peripheral edge of the plastic lens; One end of the peripheral wall portion is open to the upper end opening of the jig, and the other end is located at the same height position or below the lowermost lens mounting portion, and communicates with the inside and outside of the jig for at least one lens removal. The concave portion is provided, and the height from the lower end side opening surface of the jig to the lowermost lens mounting portion is such that when the plastic lens is mounted on the lens mounting portion with the convex surface facing down, the lens convex surface is Projects from the lower end side opening surface A jig for manufacturing a plastic lens, wherein the jig is set at a height not to be changed.