JP2011093151A - Method for manufacturing plastic lens and injection compression molding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing plastic lens which can simultaneously mold a plurality of plastic lenses having respectively different optical surface shapes and different volumes without spoiling their molding accuracy by one mold, and to proved an injection compression molding machine used in the method. <P>SOLUTION: The conditions of a molding cycle in which after a mold 50 is clamped, a raw material resin is injected/packed into/in the cavities 3a and 3b of the mold 50, and after that the mold 50 is opened are set to be the same as those when only a plastic lens having the largest volume is molded, so that a plurality of the plastic lenses different in volumes are molded simultaneously by one mold. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a plastic lens having different optical surface shapes and simultaneously molding a plurality of plastic lenses having different volumes, and an injection compression molding apparatus used in such a method.

  Conventionally, an injection compression molding method using a thermoplastic resin such as a polycarbonate resin or a methacrylic resin is known as a method for molding a plastic lens for spectacles. For example, Patent Document 1 discloses an example of such an injection compression molding method. By further compressing a resin injected and filled in a cavity of a mold, optical distortion and surface accuracy due to resin shrinkage are disclosed. I'm trying to control the decline.

In addition, as a method of manufacturing a plastic lens for spectacles, a lens is molded in a state of a semi-finished product that is thicker than the finished dimensions, and this semi-finished product called a semi-finished lens is finally processed by post-processing. It is also known to finish in shape.
Such a method is mainly employed in the manufacture of progressive power lenses used for bifocal glasses, and many of the progressive power lenses are a plurality of semi-finished lenses formed to have different optical surface shapes. Are prepared, a suitable lens is selected from these according to the prescription of the user, processed so as to satisfy the prescription, and finished to a final shape.

JP2000-6216

  By the way, when manufacturing a progressive power lens, a lens design is made by taking into account the addition power in addition to the distance diopter, and the optimum prescription is determined for each user, and further on the left and right eyes of the same user. But it ’s different. For this reason, as described above, the progressive power lens is finished from the semi-finished lens, so that the range that can be handled is widened. If so, the number of semi-finished lenses to be prepared becomes extremely large.

Also, when molding such a semi-finished lens, if it is frequently used, it is possible to increase its production efficiency by simultaneously molding many using one mold. If the frequency is low, it is not preferable to mold a large number of them at the same time from the viewpoint of inventory management.
For this reason, even if the optical surface shape and volume are different so that it can be used for a variety of small-quantity production regardless of the frequency of use, it is possible to mold multiple plastic lenses simultaneously with a single mold. It is desired to increase production efficiency.

  However, although Patent Document 1 shows an example of molding two plastic lenses, this example is premised on molding plastic lenses having the same shape.

Therefore, as a result of repeated studies by the present inventors, various conditions in the molding cycle are set to be the same as the conditions in the case where only the plastic lens having the largest volume is molded. It has been found that even if the optical surface shapes and volumes are different, a plurality of plastic lenses can be molded simultaneously without impairing the molding accuracy, and the present invention has been completed.
That is, the present invention provides a plastic lens manufacturing method capable of simultaneously molding a plurality of plastic lenses having different optical surface shapes and different volumes with a single mold without impairing the molding accuracy thereof, and the like. It is an object of the present invention to provide an injection compression molding apparatus used for such a method.

  In the plastic lens manufacturing method according to the present invention, in simultaneously molding a plurality of plastic lenses having different optical surface shapes and different volumes with one molding die, the molding die is closed, and then the molding die The same conditions as in the case of molding only the plastic lens with the largest volume among the plastic lenses are the same as those in the molding cycle until the molding resin is injected and filled into the cavity of the mold and then the mold is opened. There is a way to set.

  The injection compression molding apparatus according to the present invention is an injection for compressing and compressing a raw material resin injected and filled in a cavity and simultaneously molding a plurality of plastic lenses having different optical surface shapes with a single mold. In the compression molding apparatus, the volume of the cavity formed when the mold is closed is set to a volume obtained by adding a compression allowance to the volume of the plastic lens to be molded. The cavity is designed such that the volume of the cavity is variable and the plastic lenses to be molded have different volumes.

  According to the present invention, a plurality of plastic lenses having different optical surface shapes and different volumes can be simultaneously molded with one molding die without impairing molding accuracy.

It is explanatory drawing which shows the outline of embodiment of the injection compression molding apparatus which concerns on this invention. It is sectional drawing which shows the outline of the shaping | molding die with which embodiment of the injection compression molding apparatus which concerns on this invention is provided. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is explanatory drawing which shows an example of a lens shape. It is explanatory drawing which shows the example of the molded article shape | molded in embodiment of the manufacturing method of the plastic lens which concerns on this invention.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

First, the overall configuration of the injection compression molding apparatus according to the present embodiment will be described.
FIG. 1 is an explanatory view showing an outline of an injection compression molding apparatus according to the present embodiment. The injection compression molding apparatus shown in FIG. 1 includes a mold 50 having a movable mold 1 and a fixed mold 2 divided by a parting line PL, and a mold clamping that opens and closes and molds the mold 50 by a toggle link mechanism 65. An apparatus 60 and an injection apparatus 80 that plasticizes, kneads, and measures the raw material resin charged from the hopper 81 and injects it from the nozzle 85 are provided.
In FIG. 1, the vicinity of the nozzle 85 of the injection device 80 is cut out. As the raw material resin, a thermoplastic resin such as a polycarbonate resin or an acrylic resin generally used for molding this type of plastic lens can be used.

The mold clamping device 60 has a plurality of tie bars 63 installed between a fixed die plate 61 and a rear plate 62 erected on a gantry 66 at predetermined intervals, and the movable die plate 64 is guided by the tie bar 63 and moved. It is configured to be possible. A molding die 50 is attached between the fixed die plate 61 and the movable die plate 64, and a toggle link mechanism 65 is attached between the rear plate 62 and the movable die plate 64.
As a result, when the toggle link mechanism 65 is driven, the movable die plate 64 is guided by the tie bar 63 to advance and retreat, and accordingly, the mold 50 is opened and closed and the mold is clamped.

  Here, the toggle link mechanism 65 is configured so that the screwed crosshead 73 moves along the ball screw 72 as the ball screw 72 connected to a motor (not shown) rotates. When the cross head 73 moves to the movable die plate 64 side, the toggle links 71A and 71B extend linearly by the connecting links 74A and 74B, and the movable die plate 64 moves so as to approach the fixed die plate 61 (advance). To do. On the contrary, when the cross head 73 moves to the rear plate 62 side, the toggle links 71A and 71B are bent inward by the connecting links 74A and 74B so that the movable die plate 64 is separated from the fixed die plate 61. Move (retreat).

Next, the mold 50 provided in the injection compression molding apparatus according to the present embodiment will be described.
2 is a cross-sectional view showing a cross section of the molding die 50 included in the injection compression molding apparatus shown in FIG. 1 taken along a plane perpendicular to the paper surface passing through the central axis. FIG. 3 is a cross-sectional view taken along line AA in FIG. Sectional drawing and FIG. 4 are BB sectional drawings of FIG.

  In the examples shown in these drawings, the mold body 4 of the movable mold 1 is fixed to the movable die plate 64 via the mold attachment member 16, and the mold body 8 of the fixed mold 2 is attached to the mold attachment member 15. It is being fixed to the fixed die plate 61 via. As a result, the mold 50 is attached between the fixed die plate 61 and the movable die plate 64 of the mold clamping device 60.

  The mold body 4 of the movable mold 1 has two insert guide members 5a and 5b and mold plates 6 and 7 for holding them. The insert guide members 5a and 5b accommodate inserts 11a and 11b as cavity forming members. The inserts 11a and 11b include one surface of a plastic lens to be molded (in the example shown, a concave surface). A molding surface corresponding to the side surface) is formed.

  On the other hand, the mold body 8 of the fixed mold 2 has two insert guide members 9 a and 9 b and a mold plate 10, and the insert guide members 9 a and 9 b are held by the mold plate 10 and the mold mounting member 15. Has been. The insert guide members 9a and 9b accommodate inserts 12a and 12b as cavity forming members. The inserts 12a and 12b include the other surface of the plastic lens to be molded (in the example shown, a convex surface). A molding surface corresponding to the side surface) is formed.

A molding die 50 having such a movable die 1 and a fixed die 2 includes an insert 11a, 11b on the movable die 1 side and an insert 12a, 12b on the fixed die 2 side between the movable die 1 and the fixed die 2. Cavities 3a and 3b including the molding surfaces formed in each are formed. In the present embodiment, a plurality of plastic lenses having different optical surface shapes and different volumes are to be molded, and the cavities 3a and 3b are designed so that the optical surface shapes and volumes of the plastic lenses to be molded are different. Has been.
A runner 49 as a resin flow path connected to each cavity 3a, 3b through the gate G is formed between the movable mold 1 and the fixed mold 2 together with the cavities 3a, 3b. Yes. A sprue bush 47 that forms a sprue 48 connected to the runner 49 at a right angle is attached to the template 10 of the fixed mold 2.

  Here, the mold attachment member 16 on the movable mold 1 side is provided with a hydraulic cylinder 19 corresponding to each of the inserts 11 a and 11 b, and a piston rod 21 connected to the piston 20 is connected to one end of the hydraulic cylinder 19. It penetrates through the back insert 22 fixed to the side. A T-shaped clamp member 23 provided at the tip of each piston rod 21 is formed in a T-shaped groove 24 formed on the back surface (surface opposite to the surface on which the molding surface is formed) of the inserts 11a and 11b. Engageable and detachable.

  As a result, the piston rods 21 of the respective hydraulic cylinders 19 are moved forward with the molds 50 opened, and the T-shaped clamp members 23 provided at the tips of the piston rods 21 are moved from the insert guide members 5a and 5b. By projecting, the inserts 11a and 11b can be exchanged according to the plastic lens to be molded. When the piston rod 21 of each hydraulic cylinder 19 is retracted, the inserts 11a and 11b attached to the T-shaped clamp member 23 are accommodated inside the insert guide members 5a and 5b.

  Similarly, the die mounting member 15 on the fixed die 2 side is also provided with a hydraulic cylinder 26 corresponding to each of the inserts 12 a and 12 b, and a piston rod 28 connected to the piston 27 is provided in the die mounting member 15. It penetrates. A T-shaped clamp member 29 provided at the tip of each piston rod 28 is formed in a T-shaped groove 30 formed on the back surface of the inserts 12a and 12b (the surface opposite to the surface on which the molding surface is formed). Engageable and detachable.

  As a result, the piston rods 28 of the respective hydraulic cylinders 26 are advanced in a state where the mold 50 is opened, and the T-shaped clamp members 29 provided at the tips of the respective piston rods 28 are removed from the insert guide members 9a and 9b. By projecting, the inserts 12a and 12b can be exchanged according to the plastic lens to be molded. When the piston rod 28 of each hydraulic cylinder 26 is retracted, the inserts 12a and 12b attached to the T-shaped clamp member 29 are accommodated inside the insert guide members 9a and 9b.

  When the mold body 4 of the movable mold 1 is fixed to the movable die plate 64, the mold body 4 is bolted to the mold mounting member 16 composed of the first member 16A and the second member 16B, as shown in FIG. 17 is attached. At this time, a plurality of disc springs 17 </ b> A inserted on the outer periphery of the bolt 17 are interposed between the mold body 4 of the movable mold 1 and the mold mounting member 16, and the mold body 4 and the mold of the movable mold 1 are interposed. A gap S is formed between the mounting member 16 and the mounting member 16.

The gap S is generated when the movable die plate 64 further advances after the molding die 50 is closed, and the die mounting member 16 guided by the guide pins 18 is pressed against the elastic force of the disc spring 17A. It is designed to be closed. Accordingly, in the illustrated example, each of the hydraulic cylinders 19 provided on the mold attachment member 16 presses the inserts 11 a and 11 b via the back insert 22. Thereby, the volume of the cavities 3a and 3b when mold clamping is made variable, and the raw material resin injected and filled in the cavities 3a and 3b can be pressurized and compressed by the inserts 11a and 11b.
The guide pin 18 protrudes toward the fixed mold 2 so as to guide the opening / closing operation of the mold 50 and is inserted through an insertion hole formed in the fixed mold 2.

A pressure receiving member 32 is attached to the other end side of the hydraulic cylinder 19 provided on the die attaching member 16 on the movable die 1 side. When the eject rod 34 inserted from the hole 33 formed in the mold attachment member 16 presses the pressure receiving member 32, the hydraulic cylinder 19, the back insert 22 and the insert 11 are also pressed, and the lens molded in the cavity 3 is Extruded.
At the same time, an eject pin 35 is disposed at the center of the mold attachment member 16 so as to be movable back and forth in parallel with the opening / closing direction of the mold 50. When the pressure receiving member 36 attached to the eject pin 35 is pressed by the eject rod 38 inserted from the hole 37 formed in the mold attaching member 16, the eject pin 35 is pushed out.
Therefore, when the mold is opened, the ejected rods 34 and 38 are advanced to take out the molded product.

  As shown in FIG. 3, the spring force of the spring 40 wound around the outer periphery of the eject return pin 39 acts on the pressure receiving member 32 in the left direction in FIG. In addition, as shown in FIG. 4, the spring force of the spring 42 wound around the outer periphery of the eject return pin 41 also acts on the pressure receiving member 36 in the left direction in FIG. 4. Thus, when the eject rods 34 and 38 are retracted, the pressure receiving members 32 and 36 are also retracted and returned to the standby position.

  Moreover, the shaping | molding die 50 has the nozzle shut mechanism 90 which obstruct | occludes the nozzle 85 of the injection apparatus 80, as shown in FIG. The nozzle shut mechanism 90 has a nozzle shut pin 91 as a blocking member protruding into the sprue 48 formed by the sprue bush 47. The nozzle shut pin 91 is connected to a piston rod 94 of a hydraulic cylinder 93 via a connecting piece 92, and the hydraulic cylinder 93 is fixed to the mold mounting member 15 by a cylinder mounting plate 95. Thus, when the hydraulic cylinder 93 is driven in a state where the nozzle 85 is in pressure contact with the sprue bush 47, the nozzle shut pin 91 protrudes into the sprue 48 and closes the nozzle 85, thereby preventing back flow of the raw material resin. ing.

In the present embodiment, by using the injection compression molding apparatus as described above, a plurality of plastic lenses having different optical surface shapes and different volumes are simultaneously molded with one molding die 50. Although the specific aspect is demonstrated below, the plastic lens shape | molded in this embodiment is a meniscus lens which has a convex surface and a concave surface, More specifically, the lens for spectacles shape | molded as a semi-finished lens In this case, the convex surface side is formed as a different optical surface shape, and the concave surface side is formed by a common concave surface.
For convenience, the plastic lens molded in the cavity 3a is a first molding target lens, and the plastic lens molded in the cavity 3b is a second molding target lens.

In designing the cavities 3a and 3b, the optical surface shape of each lens is determined based on lens design information relating to the optical surface shapes of the first lens to be molded and the second lens to be molded simultaneously. The lens design information related to the optical surface shape includes, for example, a base curve, a near power, a far power, and an addition power in the case of a progressive power lens, and these determine the optical surface shape of each lens. At this time, it is preferable that the optical surface shape of each lens is formed from the same base curve so that the optical surface shape is not greatly different.
Then, the center thickness CT is set in consideration of the processing allowance when finishing to the final shape, and the lens shapes of the first molding target lens and the second molding target lens are set so that each is molded to the same diameter. The cavities 3a and 3b are designed based on the lens shape at this time.
Here, FIG. 5 shows an example of the lens shapes of the first molding target lens and the second molding target lens that are simultaneously molded in the present embodiment.
In addition, the example shown to Fig.5 (a) is a 1st shaping | molding target lens, and the example shown in FIG.5 (b) is a 2nd shaping | molding target lens.

  The raw material resin is injected and filled into the cavities 3a and 3b designed in this way and molded into a predetermined lens shape. For this purpose, first, the toggle link mechanism 65 is driven to advance the cross head 73. Let Thus, the mold 50 is closed. At this time, even after the movable mold 1 and the fixed mold 2 are brought into close contact with each other at the parting line PL, the cross head 73 is further advanced to form a gap formed between the mold body 4 of the movable mold 1 and the mold mounting member 16. By appropriately adjusting the interval of S, the volume of the cavities 3a and 3b formed between the movable mold 1 and the fixed mold 2 is set to a volume obtained by adding a compression allowance to the volume of the plastic lens to be molded. To.

Next, the raw material resin weighed to a predetermined amount is injected from the nozzle 85 of the injection device 80 and filled into the cavities 3a and 3b through the sprue 48, the runner 49 and the gate G. At this time, the raw material resin is weighed so that the volume of the sprue 48 and the runner 49 is added to the volume of the plastic lens to be molded.
Next, immediately before the injection filling of the raw material resin is completed, the cross head 73 is further advanced. Then, after the injection filling is completed, the nozzle shut pin 91 is protruded into the sprue 48 by the nozzle shut mechanism 90 and the nozzle 85 is closed. As a result, the raw material resin is contained in the mold 50 in a compressed and pressurized state.

  And the raw material resin enclosed in the shaping | molding die 50 is cooled in the state compressed and pressurized. Then, the raw material resin injected and filled in the cavity 3 is solidified and contracted as the cooling proceeds in a compressed state, and a plastic lens having a predetermined volume is molded. With the shrinkage of the raw material resin at this time, the volumes of the cavities 3a and 3b are also reduced, and a plastic lens having a desired volume is molded.

Thereafter, the crosshead 73 of the toggle link mechanism 65 is moved backward to open the mold 50. When the mold is opened, the eject rods 34 and 38 are moved forward to take out the molded product 101 formed in the form shown in FIG.
Here, the molded product 101 shown in FIG. 6 is molded by the cavities 3a and 3b, respectively, the first molding target lens lens 102a, the second molding target lens 102b, and the connecting portion 103 molded by the runner 49. And a rod-shaped portion 104 formed by the sprue 48. As described above, in the present embodiment, the first molding target lens lens 102a and the second molding target lens 102b are molded as semi-finished lenses and are taken out from the molding die 50 as needed. After being subjected to post-treatment such as abrasion treatment, and finished into a final shape, it is put on the market as a spectacle lens.

In molding the plastic lens as described above, in this embodiment, the molding die 50 is closed, and then the raw material resin is injected and filled into the cavities 3a and 3b of the molding die 50. The conditions in the molding cycle until the mold is opened are set to be the same as the conditions when only the plastic lens having the largest volume is molded.
Specifically, the injection speed and injection pressure when injecting the raw material resin from the injection device 80, the temperature management of the mold 50, and the time to start pressurizing and compressing the raw material resin injected and filled in the cavities 3a and 3b In addition, the molding lens having the larger volume is molded by comparing the molding conditions such as the pressing force, the cooling time, and the time from the completion of the injection to the mold opening to compare the first molding target lens and the second molding target lens. It is set to a condition suitable for the case.

  Usually, the molding cycle time for molding a plastic lens becomes longer as its volume increases. Therefore, by setting the molding conditions based on the plastic lens with the largest volume, the plastic lens with a smaller volume than this does not run out of time required for each process during molding. Molding takes a sufficient amount of time. Thereby, it is considered that a plurality of differently shaped plastic lenses 102a and 102b having a good optical surface shape can be simultaneously molded without impairing the molding accuracy.

  In addition, it is preferable that each plastic lens shape | molded simultaneously is shape | molded by the same diameter. The plastic lens having the smallest volume is preferably 80% or more of the volume of the plastic lens having the largest volume.

  Further, in this embodiment, after a predetermined amount of the raw material resin is injected, a blocking member is projected into the sprue to close the nozzle, thereby preventing convection of the raw material resin filled in the cavities 3a and 3b. can do. In this state, the volume of the cavity can be varied during mold clamping, and a plastic lens is molded by injection compression molding, so that the pressure applied to the raw material resin in the cavity is made uniform, and different optical surfaces can be made more accurately. A plurality of plastic lenses having a shape can be molded.

  Hereinafter, the present invention will be described in more detail with reference to specific examples.

[Example 1]
Each lens shape was designed for lens A and lens B having different optical surface shapes. The lens design information regarding the optical surface shapes of the lens A and the lens B is as follows. The center thickness of the lens A is 9.90 mm, and the center thickness of the lens B is 10.50 mm.
(Lens A)
Base curve: 2.00, distance power: +2.25, near power: +3.25, addition power: +1.0
(Lens B)
Base curve: 7.00, distance power: +7.76, near power: +10.76, addition power: +3.0

A molding die was prepared which was designed based on the lens shapes of the lens A and the lens B and in which two cavities having different volumes and shapes for molding the respective lenses were formed.
Using the prepared mold, Lens A and Lens B were simultaneously molded using polycarbonate resin as a raw material resin. The same molding was repeated three times, and three lenses A and B were molded. Various conditions regarding the molding at this time were set to be the same as the conditions when only the lens B having a large volume was molded (that is, the molding conditions of Reference Example 2 below).

The first molded lens was the first molded product, the second molded lens was the second molded product, and the third molded lens was the third molded product, and the optical surface shape of each lens was examined. The results are shown in Table 1. As shown in Table 1, all the lenses obtained optical characteristics almost as intended, and were excellent in transferability. In addition, as shown in Reference Examples 1 and 2 below, the results are inferior compared to the case where two lenses A and two lenses B are molded simultaneously.
Table 1 also shows the weights of the molded lenses A and B together.

[Reference Example 1]
A mold was prepared which was designed to mold two lenses A of Example 1 simultaneously, and formed with two cavities having the same volume and shape.
Using the prepared mold, two lenses A were molded simultaneously using polycarbonate resin as a raw material resin. Table 2 shows the result of examining the optical surface shape of each lens by repeating the same molding five times and using the first to fifth lenses as the first to fifth molded products, respectively.
In Table 2, the weights of the molded lenses A are also shown.

[Reference Example 2]
A mold was prepared which was designed to mold two lenses B of Example 1 at the same time and was formed with two cavities having the same volume and shape.
Using the prepared mold, two lenses B were molded simultaneously using polycarbonate resin as a raw material resin. Table 3 shows the result of examining the optical surface shape of each lens by repeating the same molding five times and using the first to fifth lenses as the first to fifth molded products, respectively.
In Table 3, the weights of the molded lenses B are also shown.

  Although the present invention has been described with reference to the preferred embodiments, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention. Nor.

For example, in the above-described embodiment, an example in which two plastic lenses are molded at the same time has been described. However, the present invention can also be applied to a case where three or more plastic lenses are molded at the same time.
In the above-described embodiment, an example of a spectacle lens has been described. However, the plastic lens manufactured according to the present invention can be used for various purposes other than a spectacle lens.

  INDUSTRIAL APPLICABILITY The present invention can be used as a technique for simultaneously molding a plurality of plastic lenses having different optical surface shapes and different volumes with a single mold.

DESCRIPTION OF SYMBOLS 1 Movable type 2 Fixed type | mold 3a, 3b Cavity 48 Sprue 50 Molding type | mold 80 Injection apparatus 85 Nozzle 90 Nozzle shut mechanism 91 Nozzle shut pin (blocking member)

Claims (8)

In molding a plurality of plastic lenses having different optical surface shapes and different volumes simultaneously with a single mold,
The conditions in the molding cycle from the closing of the mold to the injection of the raw material resin into the mold cavity and the subsequent opening of the mold are as follows. A method for producing a plastic lens, characterized in that the setting is the same as the conditions for molding only a large plastic lens.   The method of manufacturing a plastic lens according to claim 1, wherein the optical surface shape is formed from the same base curve.   The method for producing a plastic lens according to claim 1, wherein the plastic lens is a meniscus lens having a convex surface and a concave surface.   The said plastic lens is a lens for spectacles shape | molded as a semi-finished lens, Comprising: The said convex surface is shape | molded as a different optical surface shape, and the said concave surface is shape | molded by a common concave surface. Method.   In filling the cavity with the raw material resin injected from the nozzle of the injection device through the resin flow path including the sprue formed in the mold, after a predetermined amount of the raw resin is injected, The manufacturing method of the plastic lens as described in any one of Claims 1-4 which make the interruption | blocking member protrude in this and obstruct | occlude the said nozzle.   The volume of the cavity formed when the mold is closed is set to a volume obtained by adding a compression allowance to the volume of the plastic lens to be molded, and the volume of the cavity is set at the time of clamping. The method for manufacturing a plastic lens according to claim 1, wherein the plastic lens is molded by injection compression molding as being variable. An injection compression molding apparatus for compressing and compressing a raw material resin injected and filled in a cavity and simultaneously molding a plurality of plastic lenses having different optical surface shapes with a single mold,
The volume of the cavity formed when the mold is closed is made to be the volume of the plastic lens to be molded plus the compression allowance, and the volume of the cavity can be changed during mold clamping. And
An injection compression molding apparatus, wherein the cavity is designed so that each volume of a plastic lens to be molded is formed differently.   In filling the cavity with the raw material resin injected from the nozzle of the injection device through the resin flow path including the sprue formed in the mold, after a predetermined amount of the raw resin is injected, The injection compression molding apparatus according to claim 7, further comprising a nozzle shut mechanism that projects a blocking member to close the nozzle.

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