JP2010214763A - Method and apparatus for molding thermoplastic resin lens, thermoplastic resin lens and frame for molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for molding a thermoplastic resin lens which hardly cause problems associated with the high fluidity of an injected resin material even when an ejector pin structure for mold release is employed, a molded lens and a frame for molding used in the method. <P>SOLUTION: There is prepared the frame 30 for molding which has an escape opening 31 corresponding to a lens forming space in a pair of split molds 10 and 20 and connection protrusions (32 and 33) formed so as to protrude from the escape opening 31 toward the lens forming space. The frame 30 for molding is held between the pair of split molds 10 and 20 so that the position of the escape opening 31 coincides with that of the lens molding space. The method for molding a thermoplastic resin lens comprises injecting a thermoplastic resin into the lens molding space, heating the thermoplastic resin to harden so as to mold a thermoplastic resin lens 40 bonded to the connection protrusions (32 and 33), bringing an ejection release member 23 into contact with the frame 30 for molding outside the lens molding space, with the pair of split molds 10 and 20 opened, and releasing the lens 40 molded through the connection protrusions (32 and 33) within the lens molding space from the split molds. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for molding (molding) a thermosetting resin lens, a molding apparatus, a thermosetting resin lens, and a molding frame.

  As is well known, molding resin materials for lenses are roughly classified into thermoplastic resins and thermosetting resins. Among these, the thermosetting resin is made by injecting a highly fluid resin material such as water into a mold, and heating and curing the mold to form a molded lens.

JP 2001-194511 A

  As is clear from the fact that a typical epoxy resin is used as an adhesive, the thermosetting resin exhibits strong adhesiveness, and therefore has a high degree of adhesion to the mold during heat curing and poor release properties. On the other hand, since it exhibits high fluidity when injected into the mold, it also enters a slight gap in the mold. For this reason, in order to separate the molded lens from the mold, if a protruding pin structure generally used in thermoplastic resin molds is adopted, the gap between the protruding pin and its sliding hole (advance / retreat hole) Since the resin material also enters and adheres to (clearance) and hardens, frequent cleaning (burr removal) work is required. For this reason, the actual situation is that a molded lens made of a thermosetting resin material has a low yield and is difficult to manufacture efficiently. This difficulty is particularly remarkable in a micro lens having a diameter of several millimeters.

  The present invention is based on the above-mentioned problem consciousness about the molding method of the thermosetting resin lens, and even if an extruding pin structure for mold release is adopted, molding due to the high fluidity of the injected resin material does not easily occur. The object is to obtain a method, a molding device, a molded lens and a molding frame used for molding.

  The present invention provides a method for molding a thermosetting resin lens, the step of preparing a pair of split molds for forming a lens molding space for injecting a thermosetting resin; a relief opening corresponding to the lens molding space; Preparing a molding frame having a connecting projection formed by projecting from the relief opening toward the lens molding space; between the pair of split molds, the position of the relief opening is set to the position of the lens molding space. A step of fitting and molding a molding frame; a step of injecting a thermosetting resin into the lens molding space, heating and curing, and molding a thermosetting resin lens coupled to the connecting protrusion. And with the pair of split molds opened, the mold release member is brought into contact with the molding frame outside the lens molding space, and the lens molding is performed via the connecting projection. It is characterized by having: a step for releasing the split mold a molded lens within between.

  In a preferred embodiment of the molding method according to the present invention, the molding method further includes the step of cutting the connecting projection of the molding frame outside the lens molded in the lens molding space to separate the molding lens and the molding frame.

  The relief opening of the molding frame has a flat circular shape like the lens molding space, and a constricting ring part concentric with the relief opening and a bridging part connecting the outside of the relief opening and the restricting ring part as a connecting protrusion. The formed lens and the molding frame can be separated by providing and cutting the bridge portion.

  Alternatively, the relief opening of the molding frame is similarly made into a flat circle, and the connecting projection is configured by a radially extending portion extending from the inner peripheral edge of the relief opening into the lens molding space. By cutting the direction extending portion, the molded lens and the molding frame can be separated.

  The connecting projection of the molding frame is bonded to the surface of the molded lens when the molding of the lens is finished, and can be peeled off from the molded lens later.

  In the aspect of the thermosetting resin lens, the present invention is characterized in that the connecting protrusion is present in the lens formed by the above-described method for forming a thermosetting resin lens.

  In addition, a front circular lens formed by molding a thermosetting resin is characterized in that a circular aperture ring portion serving as an aperture stop of the lens is embedded (embedded) in the lens.

  The present invention provides a molding frame for use in the molding method for a thermosetting resin lens as described above, wherein the molding frame for a thermosetting resin lens has a plurality of relief openings and connecting protrusions. Yes.

  In the aspect of the thermosetting resin lens molding apparatus according to the present invention, a pair of split molds forming a lens molding space for injecting a thermosetting resin; the pair of split molds sandwiched between the pair of split molds A molding frame made of a member different from the split mold; a relief opening formed in the molding frame corresponding to the lens molding space, and a lens formed by projecting from the relief opening toward the lens molding space A connecting protrusion that is at least partially coupled to the thermosetting resin lens molded in the molding space; and at least one of the pair of split molds, and is positioned outside the lens molding space of the molding frame to advance and retract An extruding mold release member that is supported in such a manner that the lens molded in the lens molding space is released from the split mold through the connecting projections in contact with the molding frame. .

  The relief opening of the molding frame has a flat circular shape like the lens molding space, and a constricting ring part concentric with the relief opening and a bridging part connecting the outside of the relief opening and the restricting ring part as a connecting protrusion. The formed lens and the molding frame can be separated by providing and cutting the bridge portion.

  Alternatively, the relief opening of the molding frame is similarly made to be a flat circle, and the connecting protrusion is configured by a radially extending portion extending from the inner peripheral edge of the relief opening into the lens molding space. The forming portion can be cut to separate the molding lens and the molding frame.

  According to the present invention, even when an extruding pin structure for mold release is adopted in molding a thermosetting resin lens, burrs are frequently generated due to the inflow of the thermosetting resin to the sliding portion of the extruding pin. Therefore, the thermosetting resin lens can be efficiently manufactured with a high yield.

It is a top view which shows one Embodiment of the shaping | molding apparatus of the thermosetting resin lens by this invention. It is sectional drawing which follows the II-II line of FIG. It is a partially expanded sectional view of FIG. It is a top view which shows one Embodiment of the flame | frame for shaping | molding used for the shaping | molding apparatus of the thermosetting resin lens by this invention. FIG. 5 is an enlarged plan view of a part of FIG. 4 (one escape opening portion of the molding frame) showing a state where a lens is molded on the molding frame of FIG. 4. FIG. 6 is a plan view corresponding to FIG. 5, showing another embodiment of a molding frame. FIG. 6 is a plan view corresponding to FIG. 5, showing another embodiment of a molding frame. It is an expanded sectional view which shows another embodiment of the shaping | molding apparatus of the thermosetting resin lens by this invention. It is an enlarged plan view which shows the state which shape | molded the lens to the frame for shaping | molding of the shaping | molding apparatus of FIG. FIG. 10 is a plan view corresponding to FIG. 9 showing another embodiment of the molding frame.

  1 to 3 show an embodiment of a thermosetting resin lens molding apparatus according to the present invention. The upper mold (movable mold) 10 and the lower mold 20 (fixed mold) that form a pair of split molds that move toward and away from the parting line PL are a plurality (four in the illustrated example) of the same shape facing each other. Lens molding recesses (lens molding spaces) 11 and 21 are provided. The lens molding recesses 11 and 21 in the illustrated example form a biconvex lens having a flat (front) circular shape. The effective diameter forming recesses 11E and 21E through which a light beam passes and the non-effective diameter forming recesses 11F and 21F surrounding the same are formed. And have. The effective diameter forming recesses 11 </ b> E and 21 </ b> E form a convex lens portion 41 of the thermosetting resin lens 40, and the non-effective diameter forming recesses 11 </ b> F and 21 </ b> F form an annular flat plate portion 42 that surrounds the convex lens portion 41.

  The lower mold 20 is formed with a frame housing recess 22 for housing a molding frame (plate) 30 having a size that covers all four lens molding recesses 21. In this embodiment, the bottom height of the frame housing recess 22 is shallower than the bottom height of the ineffective diameter forming recess 21F of the lower mold 20 (see FIG. 3).

  The molding frame 30 (frame housing recess 22) is made of a metal material or a heat-resistant synthetic resin material (withstands the temperature at which the thermoplastic resin material is heat-cured), and has a flat rectangular shape as shown in FIG. The upper mold 10 and the lower mold 20 are provided with four circular relief openings 31 corresponding to the four lens molding recesses 11 and the lens molding recesses 21. The inner diameter of the relief opening 31 is the same as the maximum diameter of the lens molding recess 11 (21) (the outer diameter of the ineffective diameter forming recess 11F (21F)). In the escape opening 31, a throttle ring portion 33 connected by a radial bridge portion 32 is located. A plurality (three in this example) of the bridging portions 32 are arranged at equal angular intervals in the circumferential direction. The bridging portion 32 and the narrowing ring portion 33 constitute a buried protrusion (connecting protrusion) that is buried (embedded) in the annular flat plate portion 42 of the thermosetting resin lens 40, and the narrowing ring portion 33. (Inner diameter) constitutes the aperture stop of the convex lens portion 41 of the thermosetting resin lens 40 (set to the diameter). Further, two positioning holes 34 are formed in the molding frame 30.

  In the lower mold 20, sliding holes 24 for a plurality of (many) protruding release rods (extruded release members) 23 are formed at positions sufficiently separated from the four lens molding recesses 21. The protruding release rod 23 can be slid from the outside of the lower mold 20 independently of the lower mold 20. The extrusion release rod of a normal injection mold protrudes a molded product, whereas the extrusion release rod 23 of the present embodiment does not protrude a molded thermosetting resin lens 40, but a bridge. The molding frame 30 coupled to the thermosetting resin lens 40 is protruded through the entangled portion 32 and the narrow ring portion 33.

  A resin injection port (gate) 12 is formed in the upper mold 10 so as to communicate with the ineffective diameter forming recesses 11F of the lens molding recesses 11.

  A molding method of the thermosetting resin lens having the above-described configuration by the molding apparatus is as follows. In a state where the upper mold 10 and the lower mold 20 are separated from each other with the parting line PL as a boundary, the molding frame 30 is set in the frame housing recess 22 of the lower mold 20. When the molding frame 30 is set, two positioning holes 34 can be used (for example, the lower mold 20 can be provided with a protrusion that fits in the positioning hole 34). Thereafter, when the upper mold 10 and the lower mold 20 are brought close to each other and clamped, the lower surface of the upper mold 10 and the upper surface of the lower mold 20 (frame housing recess 22) are brought into close contact with the front and back surfaces of the molding frame 30. At this time, a slight gap may occur between the front and back surfaces of the molding frame 30 and the lower surface of the upper mold 10 and the upper surface of the lower mold 20 (frame housing recess 22). The (sliding hole 24) is located far from the lens molding recess 21 to the extent that the resin material does not reach even if a highly fluid thermosetting resin material enters the gap.

  In the above mold clamping state, the thermosetting resin material in a fluid state is injected from the resin injection port 12 of the upper mold 10 into the lens molding space formed by the lens molding recesses 11 and 21. At this time, the thermosetting resin material is injected into the lens molding space so as to sandwich the bridging portion 32 and the aperture ring portion 33 of the molding frame 30. After the injection, when the upper mold 10 and the lower mold 20 are heated to a predetermined temperature (for example, about 150 ° C.) and cured, the thermosetting resin lens 40 is molded by the lens molding recesses 11 and 21. In this molding completed state, as shown in FIG. 5, the bridging portion 32 and the aperture ring portion 33 of the molding frame 30 are buried and integrated in the annular flat plate portion 42 of the thermosetting resin lens 40. .

  When the above molding is completed, the upper mold (movable mold) 10 is moved away from the lower mold (fixed mold) 20 to separate (open) the upper mold 10 and the lower mold 20. The upper mold 10 and the lower mold 20 are provided with means so that the molded thermosetting resin lens 40 remains on the lower mold 20 side. For example, a means for providing a pressing frame 30 and a thermosetting resin lens 40 to the lower mold 20 side on the upper mold 10 side and applying a release agent to the upper mold 10 is possible. Next, when a plurality of protruding release rods 23 are simultaneously protruded in the direction of the parting line PL, the molding frame 30 is pressed in the direction of the upper mold 10 to be separated (released) from the frame housing recess 22 of the lower mold 20. The thermosetting resin lens 40 connected to the molding frame 30 via the bridging portion 32 and the narrowing ring portion 33 is separated (released) from the lower mold 20.

  Finally, the bridging portion 32 of the molding frame 30 is cut by the cutting portion 32 </ b> C (FIG. 5), and the thermosetting resin lens 40 is taken out from the molding frame 30. The thermosetting resin lens 40 includes a diaphragm ring portion 33 and can be used as it is as a molded lens having an aperture diaphragm.

  The aperture ring portion 33 does not necessarily have a diameter as an aperture stop, or may be omitted. FIG. 6 is an embodiment in which only a plurality (three in the illustrated example at equal angular intervals) of bridging portions (radially extending portions) 32 protrude from the inner peripheral portion of the relief opening 31 of the molding frame 30. In this embodiment, the tip end portion of the bridging portion (radially extending portion) 32 is buried in the annular flat plate portion 42 of the thermosetting resin lens 40.

  The last cutting step is not always necessary. For example, in the case where one lens molding recess 11 and 21 is provided in one upper mold 10 and one lower mold 20 (single mold), an optical device that uses the thermosetting resin lens 40 as it is as the molding frame 30. It can be used as a mounting member. In such an aspect, the molding frame 30 may be a planar circle. Further, even when a plurality is taken as in the illustrated embodiment, the same is achieved by cutting the molding frame 30 into four parts each having one thermosetting resin lens 40 without cutting the bridge portion 32. Are possible.

  In the above embodiment, the bottom height of the frame housing recess 22 is set to be shallower than the bottom height of the ineffective diameter forming recess 21F of the lens molding recess 21 so as to be molded in the annular flat plate portion 42 of the thermosetting resin lens 40. Although the bridging portion 32 and the aperture ring portion 33 of the frame 30 are buried, as shown in FIG. 7, the upper surface of the molding frame 30 and the lower surface of the annular flat plate portion 42 of the molding lens 40 are flush with each other. The lower mold 20 may be configured. In this aspect, a hole is formed in the bridging portion 32 (or the narrowing ring portion 33), and a thermosetting resin material is injected therein, so that the bridging portion 32 (or the narrowing ring portion 33) and the thermosetting resin lens are injected. The integrity with 40 (annular flat plate portion 42) can be enhanced.

  Alternatively, conversely, the bridging portion 32 can be peeled off without being cut. That is, the bridging portion 32 and the aperture ring portion 33 of the molding frame 30 are joined to the annular flat plate portion 42 of the thermosetting resin lens 40 at the end of lens molding, and after the lens molding is completed, the thermosetting resin lens. It is peeled from the 40 annular flat plate portions 42. In particular, in a mode in which the aperture ring portion 33 is not provided, such peeling is possible.

  In yet another embodiment, the inner diameter of the relief opening 31 is slightly larger than the maximum diameter of the lens molding recess 11 (21) (the outer diameter of the ineffective diameter forming recess 11F (21F)), and the bridge portion 32 is cut. It is also possible to make it easier. FIG. 8 shows the embodiment. In the lower mold 20, the upper mold 10 and the lower mold 20 are clamped in the gap formed by the throttle ring 33 and the bridging portion 32 of the relief opening 31. The protrusion part 25 which penetrates is formed, and the bridge part 32 can be exposed by this protrusion part 25 in a molding completion state.

  In this finished molding state, as shown in FIG. 9, the aperture ring 33 of the molding frame 30 is buried and integrated in the annular flat plate portion 42 of the thermosetting resin lens 40, and the thermosetting resin lens 40. In the state where a part of the bridging portion 32 of the molding frame 30 is exposed in the circumferential direction from the annular flat plate portion 42, the connecting protrusion (bridging) between the thermosetting resin lens 40 (annular flat plate portion 42) and the molding frame 30. The part 32 and the aperture ring part 33) are coupled.

  In the embodiment in which the aperture ring portion 33 is not provided, as shown in FIG. 10, the inner peripheral side portion of the bridging portion (radially extending portion) 32 is buried in the annular flat plate portion 42 of the thermosetting resin lens 40. Thermosetting in a state where the outer peripheral side portion (tip portion) of the bridging portion (radially extending portion) 32 is exposed from the annular flat plate portion 42 of the thermosetting resin lens 40 in the circumferential direction. The resin lens 40 (annular flat plate portion 42) and the molding frame 30 are coupled.

  The thermosetting resin lens 40 molded in the above process is usually subjected to vapor deposition of an antireflection film in the next process. The two positioning holes 34 of the molding frame 30 can also be used in this vapor deposition step (and other steps that are necessary in a state where the thermosetting resin lens 40 is attached to the molding frame 30).

  In the above embodiment, the simplest biconvex lens is exemplified as a lens to be molded, but the present invention can be applied without questioning the lens shape.

  In the above embodiment, the case where the relief opening of the molding frame has a flat circular shape is exemplified, but the relief opening may have a shape corresponding to the lens molding space (at least covering the outer diameter of the lens molding space). For example, the shape may be a polygon such as a quadrangle or a pentagon, or an ellipse.

10 Upper mold (split mold)
20 Lower mold (split mold)
11 21 Lens molding recess 11E 21E Effective diameter forming recess 11F 21F Ineffective diameter forming recess 12 Resin inlet 22 Frame housing recess 23 Extrusion release rod (extrusion release member)
24 Sliding hole 25 Protruding part 30 Molding frame (plate)
31 Escape opening 32 Bridge part (connection protrusion, radial extension part)
33 Diaphragm ring (connecting protrusion)
34 Positioning hole 40 Thermosetting resin lens 41 Convex lens part 42 Annular flat plate part

Claims (11)

Providing a pair of split molds for forming a lens molding space for injecting a thermosetting resin;
Providing a molding frame having a relief opening corresponding to the lens molding space and a connecting projection formed by projecting from the relief opening toward the lens molding space;
A step of sandwiching a molding frame between the pair of split molds so that the position of the relief opening matches the position of the lens molding space;
Injecting a thermosetting resin into the lens molding space and curing it by heating to mold a thermosetting resin lens coupled to the connecting projection; and with the pair of split molds open And a step of bringing the mold release member into contact with the molding frame on the outside of the lens molding space, and releasing the lens molded in the lens molding space from the split mold via the connecting projection;
A method for molding a thermosetting resin lens, comprising: 2. The method of molding a thermosetting resin lens according to claim 1, further comprising cutting the connecting projection of the molding frame outside the lens molded in the lens molding space to separate the molding lens and the molding frame. A method for forming a thermosetting resin lens, comprising the step of: 3. The method for molding a thermosetting resin lens according to claim 2, wherein the relief opening of the molding frame has a circular shape, and the connecting projection includes a constricting ring portion concentric with the relief opening, the escape opening enveloping, and the constriction. A thermosetting resin lens molding method in which a bridging part for connecting the ring part is included, and the bridging part is cut. 3. The method of molding a thermosetting resin lens according to claim 2, wherein the relief opening of the molding frame has a circular shape, and the connecting protrusion extends in the lens molding space from the inner periphery of the relief opening. A method for forming a thermosetting resin lens comprising an extending portion, wherein the radially extending portion is cut. 3. The method of molding a thermosetting resin lens according to claim 2, wherein the connecting projection of the molding frame is joined to the surface of the molded lens at the end of molding of the lens and is later peeled off from the molded lens. A method of molding a thermosetting resin lens. A thermosetting resin lens formed by the method for forming a thermosetting resin lens according to claim 1, wherein the connecting protrusion is present in the lens. 6. A molding frame for use in the method for molding a thermosetting resin lens according to claim 1, wherein the molding frame has a plurality of relief openings and connecting projections. 7. A pair of split molds forming a lens molding space for injecting thermosetting resin;
A molding frame made of a member different from the pair of split molds, sandwiched between the pair of split molds;
A relief opening formed in the molding frame corresponding to the lens molding space, and a thermosetting resin lens molded in the lens molding space formed by projecting from the relief opening toward the lens molding space. And at least one of the pair of split molds is supported on the outside of the lens molding space of the molding frame so as to be able to advance and retreat and abut against the molding frame. A projecting mold release member for releasing the lens molded in the lens molding space from the split mold through the connecting projection;
An apparatus for molding a thermosetting resin lens, comprising: 9. The thermosetting resin lens molding apparatus according to claim 8, wherein the relief opening of the molding frame has a circular shape, the connecting protrusion includes a restriction ring portion concentric with the relief opening, the escape opening outer periphery and the restriction. A thermosetting resin lens molding apparatus having a bridging portion for connecting a ring portion. 9. The thermosetting resin lens molding apparatus according to claim 8, wherein the relief opening of the molding frame has a circular shape, and the connecting projection extends radially from the inner periphery of the relief opening toward the lens molding space. A device for molding a thermosetting resin lens comprising a mounting portion. A thermosetting resin lens, characterized in that, in a front circular lens formed by molding a thermosetting resin, a circular aperture ring portion serving as an aperture stop of the lens is embedded in the lens.

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