JP2014069464A - Lens, molding die, and method of manufacturing the lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens in which even when a projection part is disposed at an outer peripheral side face, when handling a lens and when lenses come in contact with one another, the lens is prevented from being damaged.SOLUTION: A lens 10 is a lens that is manufactured by a molding die 100 for injection molding using a pin-point gate mechanism 40 or a hot-runner mechanism 20, and includes: an optical part 10a; an outer periphery 10b that extends in a surrounding of the optical part 10a; and a projection part 10c that projects from an outer peripheral side face S5 of the outer periphery 10b in an outer circumferential direction. A tip face S11 of the projection part 10c separated from the outer peripheral side face S5 has four sides as outer edges of the tip faces S11, and at least three sides of four sides have chamfered parts 10f each having an R shape.

Description

  The present invention relates to a lens for controlling a luminous flux from an LED or the like, a molding die for manufacturing the lens, and a method for manufacturing the lens.

  The lens that controls the illumination light beam is also called a light beam control member, and has a special optical surface and is disposed so as to cover the light source. When forming such a lens, an injection molding method is used in which molten resin is injected and filled from a gate into a cavity (mold space) formed by closing two molding dies from the viewpoint of cost. Yes.

  Some lenses for light flux control have a gate cut mark that is cut in a state in which a gate portion serving to fill a cavity with molten resin is left (see, for example, Patent Document 1). Here, the gate cut trace is formed as a protrusion protruding in the outer peripheral direction from the outer peripheral side surface of the lens. The four corners of the tip of this projection are squared. Generally, at the time of gate cutting, the gate portion is cut with a blade. In this case, a plurality of fine acute-angled rupture protrusions are formed on the tip surface of the protrusion by shear fracture.

  Lenses such as a light flux controlling member often collide or come into contact with each other during the manufacture and distribution of the lens. For example, when the released lens is dropped from the mold apparatus and accumulated, the corners of the lens may be lost due to the impact of the drop, or collision or contact between the lenses may occur. Moreover, when many lenses are packed in one plastic bag for cost reduction, collision or contact between adjacent lenses occurs. Further, when a large number of plastic bags filled with lenses are packed in a cardboard box for distribution, damage to the lenses, collision between lenses or laceration due to contact due to impact caused by dropping of the cardboard boxes or the like occurs. If the tip of the protrusion on the gate cut mark is square or if there is a rupture protrusion as described above on the tip surface, a part of the rupture protrusion may be missing due to an impact, The tip of the protrusion of the gate cut trace may contact the optical surface of the other lens and damage the optical surface. There is a problem that this scratch causes uneven illuminance on the surface to be irradiated.

  In addition, as a method for preventing corners and fractured protrusions from being generated at the tips of the protrusions, a method of removing the gate part by cutting with a blade such as an end mill can be considered. However, there is a problem that the cost is significantly increased as compared with the method of cutting the gate portion because cutting equipment and equipment for removing cutting powder are required, and time required for cutting is required.

JP 2011-65851 A

  An object of the present invention is to provide a lens that can prevent the lens from being damaged when the lens is handled or when the lenses come into contact with each other even when the protrusion is provided on the outer peripheral side surface.

  Another object of the present invention is to provide a molding die for manufacturing the above-described lens and a method for manufacturing the lens.

  In order to achieve the above object, a lens according to the present invention is a lens manufactured by a molding die for injection molding using a pinpoint gate mechanism or a hot runner mechanism, and includes an optical part and a periphery of the optical part. An outer peripheral portion that extends, and a protruding portion that protrudes in an outer peripheral direction from the outer peripheral side surface of the outer peripheral portion, and a distal end surface that is separated from the outer peripheral side surface of the protruding portion has four sides as outer edges of the distal end surface, At least three of the four sides have an R-shaped chamfer. Here, the outer peripheral portion means an outer peripheral portion of the optical portion, and includes a case where the width is substantially or substantially zero.

  In the lens, at least three of the four sides of the tip surface of the protrusion extending from the outer periphery of the lens have an R-shaped chamfered portion, and the protrusion is not in an angular state. Thereby, even when the lenses collide and come into contact with each other, it is possible to prevent the optical surface from being damaged. In addition, by providing a protrusion on the lens, the protrusion can be used for recognizing the position of the gate portion and the lens direction. For example, when the lens is incorporated in a light emitting device, the lens can be easily handled. . For example, if the remaining one side of the tip surface is not R-shaped but linear, the remaining one side of the tip surface of the protrusion can be formed on the mold-matching surface of the mold. Mold processing becomes easy.

  According to a specific aspect or aspect of the present invention, in the lens, all four sides of the tip end surface of the protrusion have an R-shaped chamfer. In this case, since all four sides of the tip surface of the protrusion have an R shape, it is possible to further suppress the occurrence of scratches on the optical surface.

  According to another aspect of the present invention, the center of gravity is located closer to the protrusion than the optical axis of the optical part. In this case, when the lens falls, there is a high possibility that the lens will fall with the protruding portion having the R-shaped chamfered portion facing down, so that the optical surfaces of other lenses are hardly damaged.

  According to still another aspect of the present invention, the protrusion has a pair of protrusion surfaces perpendicular to the optical axis of the optical portion, and one protrusion surface of the pair of protrusion surfaces has a gate cut mark. Have. In this case, since there is no gate cut trace on the tip end side of the projection (in the outer peripheral direction of the lens), it is possible to prevent the gate cut trace from colliding with or contacting the optical surface of another lens during a drop or collision. In addition, since the protruding portion itself is not cut, it is possible to prevent a broken protrusion from being generated at the cut portion.

  According to still another aspect of the present invention, the protrusion has a pair of protrusion surfaces perpendicular to the optical axis of the optical portion, and one of the protrusion surfaces has a recess. The recess has a gate cut mark. In this case, since the gate cut trace is formed in the recess, the gate cut trace can be prevented from protruding from the surface of the protrusion.

  According to still another aspect of the present invention, the optical surface has a pair of optical surfaces, and one of the pair of optical surfaces has a convex shape. If the optical surface has a convex shape, it will be easy to hit the projection, but in the case of a lens having the projection, the optical surface will be prevented from being damaged even if it collides with or comes into contact with the optical surface of another lens. Can do.

  In order to achieve the above object, a molding die according to the present invention has a lens having an optical part, an outer peripheral part extending around the optical part, and a protruding part protruding in the outer peripheral direction from the outer peripheral side surface of the outer peripheral part. A molding die for injection molding using a pinpoint gate mechanism or a hot runner mechanism for manufacturing a first die and a second die, and at least one of the first die and the second die The mold has a concave projection transfer surface forming a projection, and at least three corners of the four corners on the tip side of the projection transfer surface with the first and second molds closed. The part has an R shape.

  In the above molding die, when a projection transfer surface is provided on one of the first die and the second die, an R shape is formed at three corners of the projection transfer surface. In addition, when the protrusion transfer surface is provided on both the first mold and the second mold, R shapes are formed at the four corners of the protrusion transfer surface. Thus, since the corner of the projection transfer surface has an R shape, R-shaped chamfered portions are formed on at least three sides of the four sides of the tip surface of the projection extending from the outer peripheral portion of the molded lens. Thereby, the corner | angular of the front end surface of a projection part is lose | eliminated, and even when lenses collide and contact, it can suppress that a damage | wound generate | occur | produces on an optical surface.

  According to another aspect of the invention, all four corners have an R shape. In this case, since the R-shaped chamfered portion is formed on all four sides of the tip end surface of the projection in the molded lens, it is possible to further suppress the occurrence of scratches on the optical surface.

  According to still another aspect of the present invention, the tip of the gate is provided on the mold matching surfaces of the first and second molds. In this case, the gate cut trace is formed on the surface of the pair of protrusions perpendicular to the optical axis of the protrusion. Thereby, since protrusion part itself is not cut, it can prevent that a fracture | rupture protrusion arises in the front end surface of a protrusion part.

  According to still another aspect of the present invention, the tip of the gate is provided at a position shifted to the opposite mold side with respect to the mold mating surfaces of the first and second molds. In this case, the gate cut mark is formed in the recess on the surface of the protrusion. Thereby, it can prevent that a gate cut trace protrudes from the projection part surface.

  According to still another aspect of the invention, the first and second molds each have an optical surface transfer surface that forms a pair of optical surfaces of the lens, and the pair of optical surfaces of the first and second molds. Of the transfer surfaces, one optical surface transfer surface has a concave shape. In this case, the molded optical surface has a convex shape.

  In order to achieve the above object, a lens manufacturing method according to the present invention manufactures a lens using the molding die described above.

  In the lens manufacturing method, it is possible to manufacture a lens having a chamfered portion in which at least three sides out of the four sides of the tip surface of the protrusion extending from the outer peripheral portion of the lens have an R shape. Thereby, even when the lenses collide and come into contact with each other, it is possible to prevent the optical surface from being damaged.

(A) is a back view of the lens of 1st Embodiment, (B) is AA arrow sectional drawing of (A), (C) is a front view of (A). It is a perspective view of the lens of FIG. (A) is a partial expanded sectional view of the shaping die for shape | molding the lens of FIG. 1 (A), (B) is a top view of a movable die among the shaping die of (A). . (A) is a partial expanded sectional view of the shaping die for shape | molding the lens of 2nd Embodiment, (B) is a top view of a movable die among the shaping die of (A). It is a reverse view of the lens manufactured with the shaping die of FIG. It is a partial expanded sectional view of the shaping die for shape | molding the lens of 3rd Embodiment. (A) is a back view of the lens manufactured with the molding die of FIG. 6, (B) is a sectional view taken along the line AA in (A), and (C) is a front view of (A). It is. (A) is a partial expanded sectional view of the shaping die for shape | molding the lens of 4th Embodiment, (B) is sectional drawing of the lens manufactured with the shaping die of (A). (A) is the elements on larger scale of the molding die for shape | molding the lens of 5th Embodiment, (B) is a top view of a movable mold among the molding dies of (A), (C) is a back view of the lens manufactured with the molding die of (A). (A) And (B) is a figure explaining the modification of the projection part of the lens of FIG.

[First Embodiment]
A lens, a molding die, and a lens manufacturing method according to a first embodiment of the present invention will be described with reference to the drawings.

  A lens 10 shown in FIGS. 1A to 1C and FIG. 2 controls a light beam for illumination from an LED (Light Emitting Diode) or the like (controls a traveling direction of a light beam emitted from a light emitting element). Lens (light flux controlling member). As shown in FIGS. 1A to 1C and FIG. 2, the lens 10 includes an optical part 10a, an outer peripheral part 10b, a protruding part 10c, and a leg part 10d.

  The optical unit 10a is a part having an optical function, and includes a pair of opposed first and second optical surfaces S1 and S2 and a flat surface S6 extending from the periphery of the first optical surface S1. The first optical surface S1 is a concave shape having a relatively larger curvature than the second optical surface S2. The first optical surface S1 is deeply recessed toward the center of the second optical surface S2. The second optical surface S2 is generally convex and has a larger diameter than the first optical surface S1. The second optical surface S2 has a shallow concave region in the center. Therefore, the center of the optical unit 10a is thin, and the periphery of the center is thick. The flat surface S6 extends substantially perpendicular to the optical axis OA and is on the same plane as the annular first outer peripheral surface S3 of the outer peripheral portion 10b. A light emitting element such as an LED for illuminating other display elements such as a liquid crystal panel is disposed on the first optical surface S1 side.

  The outer peripheral part 10b extends around the optical part 10a. The outer peripheral part 10b has a pair of opposing first and second outer peripheral surfaces S3 and S4, and an outer peripheral side surface S5 connecting the first and second outer peripheral surfaces S3 and S4. The first and second outer peripheral surfaces S3 and S4 extend substantially perpendicular to the optical axis OA of the lens 10, and the outer peripheral side surface S5 extends substantially parallel to the optical axis OA.

  The protruding portion 10c protrudes from the outer peripheral side surface S5 of the outer peripheral portion 10b in the outer peripheral direction. That is, the protruding portion 10c is provided so as to extend to the outside of the outer peripheral portion 10b. The protrusion 10c is a flat portion, and specifically, a rectangular plate-like or block-like portion. The protrusion 10c includes a pair of first and second protrusion surfaces S7 and S8 substantially perpendicular to the optical axis OA and a pair of third and fourth protrusion surfaces S9 and substantially parallel to the optical axis OA. S10 and a tip surface S11 sandwiched between the protrusion surface S7, S8, S9, S10. A gate cut trace GS is formed on the second projection surface S8 on the second optical surface S2 side of the first and second projection surfaces S7 and S8. The gate cut trace GS is in a state of hardly protruding from the second protrusion surface S8. The tip surface S11 that is separated from the outer peripheral side surface S5 of the protrusion 10c has four sides as the outer edge of the tip surface S11 (boundary portion between the tip surface S11 and the other surfaces S7, S8, S9, and S10 of the protrusion 10c). In the case of the present embodiment, an R-shaped chamfered portion 10f is provided on three sides of the four sides of the distal end surface S11. The chamfered portion 10f only needs to have a curved surface that is not a sharp corner and does not damage the second optical surface S2 of the other lens 10. By providing the protrusion 10c, the lens 10 has a center of gravity on the protrusion 10c side with respect to the optical axis OA. By having the center of gravity on the protruding portion 10c side, the protruding portion 10c side having an R-shaped chamfered portion 10f when the lens 10 is freely dropped in a transporting process such as bagging when taking out from the injection molding machine. The possibility of falling from is increased. Therefore, the possibility of falling from the second optical surface S2 when falling can be reduced, and the protruding portion 10c is not easily chipped. Furthermore, even if there is another lens 10 at the fall destination, the R-shaped chamfered portion 10f takes the lead and makes it possible to reduce the influence on the second optical surface S2.

  The leg portion 10d is a portion that is attached to the support substrate of the light emitting element. The leg portion 10d has a thin cylindrical outer shape, and protrudes in a direction parallel to the optical axis OA from the flat surface S6 of the optical portion 10a. In the case of this embodiment, three leg portions 10d are provided on the same circumference around the optical axis OA of the flat surface S6.

  As shown in FIGS. 3 (A) and 3 (B), a molding die 100 for molding the lens 10 shown in FIG. 1 (A) and the like includes a fixed die 11, a movable die 12, and a hot runner. A mechanism 20 and a protrusion mechanism 30 are provided. The molding die 100 may be a horizontal type or a saddle type.

  The fixed mold 11 is supported and fixed as a first mold by a fixed plate (not shown), and a second optical surface transfer surface T2 and a second outer peripheral surface transfer are provided on the mold matching surface PP side facing the movable mold 12. It has a surface T4 and a second protrusion transfer surface T8. These transfer surfaces T2, T4, and T8 serve as a second transfer surface 11a that forms the second optical surface S2 side of the lens 10. The second optical surface transfer surface T2 corresponds to the shape of the second optical surface S2 of the lens 10 and has a shape obtained by inverting this. That is, the second optical surface transfer surface T2 has a concave shape. The second outer peripheral surface transfer surface T4 corresponds to the shape of the second outer peripheral surface S4 of the lens 10. The second protrusion transfer surface T8 (protrusion transfer surface 11b) corresponds to the shape of the second protrusion surface S8 of the lens 10. A mold space (cavity) CV is formed between the movable mold 12 and the fixed mold 11 by clamping. A nozzle end 21a of a nozzle portion 21 of the hot runner mechanism 20 described later communicates with the cavity CV via the second protrusion transfer surface T8. In addition, the fixed mold 11 is provided with a cooling path (not shown). The cooling path is for flowing cooling water or the like, and exists to prevent overheating of the fixed mold 11 (first mold) and to cool the molten resin.

  The movable mold 12 is supported by a movable plate (not shown) as a second mold and can move forward and backward with respect to the fixed mold 11. A first optical surface transfer surface T1, a first outer peripheral surface transfer surface T3, an outer peripheral side surface transfer surface T5, a flat surface transfer surface T6, and a first protrusion transfer surface on the mold-matching surface PP facing the fixed mold 11 are provided. T7, a third protrusion transfer surface T9, a fourth protrusion transfer surface T10, a tip surface transfer surface T11, and a leg portion transfer surface T12. These transfer surfaces T1, T3, T5, T6, T7, T9, T10, T11, and T12 become the first transfer surface 12a that forms the first optical surface S1 side of the lens 10. The first optical surface transfer surface T1 corresponds to the shape of the first optical surface S1 of the lens 10 and has a shape obtained by inverting this. That is, the first optical surface transfer surface T1 has a convex shape. The first outer peripheral surface transfer surface T3 corresponds to the shape of the first outer peripheral surface S3 of the lens 10. The outer peripheral side transfer surface T5 corresponds to the shape of the outer peripheral side surface S5 of the lens 10. The flat surface transfer surface T6 corresponds to the shape of the flat surface S6 of the lens 10. The first, third, and fourth protrusion transfer surfaces T7, T9, and T10 correspond to the shapes of the first, third, and fourth protrusion surfaces S7, S9, and S10 provided on the protrusion 10c of the lens 10, respectively. To do. The tip surface transfer surface T11 corresponds to the shape of the tip surface S11 of the protrusion 10c. The projection transfer surface 12b formed of the first projection transfer surface T7, the third projection transfer surface T9, the third projection transfer surface T10, and the tip surface transfer surface T11 on the movable mold 12 side has a concave shape. The corners 12c on the tip side of the projection transfer surfaces T7, T9, T10, that is, the edges of the tip surface transfer surface T11 and the first, third, and fourth projection transfer surfaces T7, T9, T10 have an R shape. Have. The corner portion 12 c corresponds to the shape of the chamfered portion 10 f of the projection portion 10 c of the lens 10. The leg transfer surface T12 corresponds to the shape of the leg 10d of the lens 10. In addition, the movable mold 12 is provided with a cooling path (not shown). The cooling path is provided to prevent overheating of the movable mold 12 (second mold) and to cool the molten resin.

  Although illustration is omitted, the movable mold 12 is formed with a plurality of first transfer surfaces 12a instead of one first transfer surface 12a. The fixed mold 11 is also formed with a plurality of second transfer surfaces 11a facing the plurality of first transfer surfaces 12a.

  The hot runner mechanism 20 is a part for supplying the resin to the cavity CV, the tip is embedded in the fixed mold 11, and the root extends behind the fixed mold 11 (hot runner mechanism 20). (For example, refer to JP 2001-170970 A).

  Although not shown, in the molding die 100, the fixed die (first die) 11 includes a plurality of hot runner mechanisms 20 corresponding to the plurality of second transfer surfaces 11a, that is, the plurality of cavities CV. Is assembled. The plurality of hot runner mechanisms 20 constitute a hot runner device (not shown). The hot runner device supplies molten resin to a plurality of cavities CV formed between the fixed mold 11 and the movable mold 12 that are clamped.

  The hot runner mechanism 20 has a nozzle portion 21 on the die matching surface PP side of the fixed die 11. The nozzle portion 21 extends in a direction perpendicular to the mold matching surface PP (movable direction AB of the movable mold 12). A nozzle end 21 a (gate), which is the tip of the nozzle portion 21, is provided on the die matching surface PP of the fixed mold 11. The nozzle unit 21 is temperature-controlled by a heater or a temperature sensor (not shown). The nozzle part 21 opens and closes the nozzle end 21a, which is the tip of the nozzle part 21, as the needle 22 inserted in the direction perpendicular to the die-matching surface PP moves forward and backward. When the opening provided in the nozzle end 21a is opened, the molten resin guided to the nozzle end 21a is injected into the cavity CV. Thereby, the injection direction of the molten resin from the nozzle end 21a is perpendicular to the mold matching surface PP and parallel to the movable direction AB of the movable mold 12.

  The ejecting mechanism 30 is urged by a drive device (not shown) and can be advanced and retracted at a desired timing along the AB direction along the axis AX of the molding die 100. As illustrated in FIG. 3B, the protrusion mechanism 30 includes a plurality of protrusion pins 31. Each protruding pin 31 is inserted into a pin hole 12 d provided in the movable mold 12. The pin holes 12d are provided at three locations so as to penetrate the flat surface transfer surface T6 of the movable mold 12. The tip of the protruding pin 31 is in a state where it faces the cavity CV in the illustrated state in which the fixed mold 11 and the movable mold 12 are clamped.

Hereinafter, a method for manufacturing the lens 10 will be described.
First, the fixed mold 11 and the movable mold 12 which are separated from each other are adjusted to a predetermined temperature in the standby state. Next, the movable mold 12 is operated and moved to the fixed mold 11 side, the fixed mold 11 and the movable mold 12 are closed, and both the molds 11 and 12 are clamped with a predetermined pressure. At this time, a cavity CV is formed between the molds 11 and 12. Next, when the needle 22 of the hot runner mechanism 20 is moved to the back side of the fixed mold 11 with both the molds 11 and 12 clamped, the nozzle end 21a is opened. Immediately after this, molten resin is injected from the injection molding machine into the cavity CV through the opening of the nozzle end 21a. When the molten resin is sufficiently filled in the cavity CV, the needle 22 moves to the front side of the fixed mold 11 and seals the nozzle end 21a. Next, the molten resin in the cavity CV is cooled by both molds 11 and 12, and the lens 10 as a molded product is obtained. In this state, when the mold opening for separating the movable mold 12 from the fixed mold 11 is performed, the lens 10 is separated from the fixed mold 11 and is attached to the movable mold 12. At this time, the protrusion surface S7 of the protrusion 10c of the lens 10 is in a state where there is almost no protrusion, with only a slight gate cut mark GS remaining due to the nozzle end 21a. Next, when the protrusion mechanism 30 is moved to the fixed mold 11 side to cause the protrusion pin 31 to perform protrusion, the lens 10 is peeled from the movable mold 12 and the release of the lens 10 is completed.

  In the lens 10 of the above embodiment, at least three sides among the four sides of the tip surface S11 of the protrusion 10c extending from the outer peripheral portion 10b of the lens 10 have a chamfered portion 10f having an R shape. For this reason, the protruding portion 10c is not in an angular state. Thereby, even when the lenses 10 collide and come into contact with each other, it is possible to suppress the generation of scratches on the optical surface, particularly the convex second optical surface S2 that is easily damaged. Further, by providing the protrusion 10c on the lens 10, the protrusion 10c can be used for recognizing the position of the gate portion and the lens direction. For example, when the lens 10 is incorporated in a light emitting device, the lens 10 can be easily handled. Can be.

  In the present embodiment, in the lens 10, one of the four sides of the tip surface S11 of the protruding portion 10c is not R-shaped but linear. Therefore, a straight side of the tip end surface S11 of the protrusion 10c can be formed by the mold matching surface PP of the fixed mold 11, and the molding mold 100 can be easily processed.

[Second Embodiment]
Hereinafter, the lens of the second embodiment will be described. The lens according to the second embodiment is a partial modification of the lens according to the first embodiment, and parts not specifically described are the same as those according to the first embodiment.

  As shown in FIG. 4A, in the molding die 100 of the present embodiment, the movable die 12 has a second transfer surface 11a, and the fixed die 11 has a first transfer surface 12a. That is, the second optical surface transfer surface T2, the second outer peripheral surface transfer surface T4, and the like are formed on the movable mold 12. Further, a first optical surface transfer surface T1 and a first outer peripheral surface transfer surface T3 are formed on the fixed mold 11. The nozzle end 21a of the nozzle portion 21 of the hot runner mechanism 20 communicates with the cavity CV via the first protrusion transfer surface T7.

  As shown in FIG. 4B, four pin holes 12d for inserting the protruding mechanism 30 are provided so as to penetrate the second outer peripheral surface transfer surface T4 of the movable mold 12.

  As shown in FIG. 5, in the lens 10 manufactured by the molding die 100 as shown in FIG. 4A, the gate cut trace GS is formed not on the second protrusion surface S8 but on the first protrusion surface S7. Is done.

[Third Embodiment]
The lens according to the third embodiment will be described below. The lens according to the third embodiment is a partial modification of the lens according to the first embodiment, and parts not specifically described are the same as those according to the first embodiment.

  As shown in FIG. 6, in this embodiment, a molten resin is introduced into the cavity CV using a pinpoint gate mechanism 40 instead of the hot runner mechanism 20. The pinpoint gate mechanism 40 is provided in the fixed mold 11.

  The pinpoint gate mechanism 40 has a structure that automatically performs gate cutting by mold opening. The molding die 100 is provided with a runner removal die (not shown) on the fixed die 11 side in addition to the fixed die 11 and the movable die 12. The runner removal mold is closed to the fixed mold 11 side during molding and separated from the fixed mold 11 during mold release. By separating the runner removal mold from the fixed mold 11, unnecessary portions such as a sprue part and a runner part other than the lens 10 are released. Thereby, the lens 10 is released by the mold opening of the movable mold 12, and after the gate is automatically cut, unnecessary portions such as the runner part are released by the mold opening of the fixed mold 11.

  The pinpoint gate mechanism 40 has a gate 41 that tapers toward the cavity CV on the die matching surface PP side. The tip 41a of the gate 41 is arranged in a state of protruding from the mold matching surface PP toward the movable mold 12 side.

  As shown in FIGS. 7A to 7C, the projection 10c of the lens 10 molded by the molding die 100 shown in FIG. 6 has a recess 10g that is recessed from the second projection surface S8. Although the gate cut trace GS of the gate 41 is formed in the recess 10g, even if the gate cut trace GS protrudes, the gate cut trace GS fits in the recess 10g. Therefore, even when the lens 10 collides with and comes into contact with another lens 10, it is possible to prevent the optical surface of the other lens 10 from being damaged.

[Fourth Embodiment]
The lens according to the fourth embodiment will be described below. The lens or the like of the fourth embodiment is a partial modification of the lens or the like of the first embodiment, and parts not specifically described are the same as the lens or the like of the first embodiment.

  As shown in FIG. 8A, the fixed mold 11 is also provided with a concave projection transfer surface 111b for forming the projection 10c of the lens 10. The protrusion transfer surface 111b includes a second protrusion transfer surface T8, a third protrusion transfer surface T9, a fourth protrusion transfer surface T10, and a tip surface transfer surface T11. The second transfer surface 11a includes a second optical surface transfer surface T2, a second outer peripheral surface transfer surface T4, an outer peripheral side surface transfer surface T5, and a protrusion transfer surface 111b. That is, the outer peripheral side transfer surface T5, the third protrusion transfer surface T9, the fourth protrusion transfer surface T10, and the tip end surface transfer surface T11 are formed on the fixed mold 11 and the movable mold 12.

  In the present embodiment, an R-shaped corner 12c is also formed at the edge between the second protrusion transfer surface T7 and the tip surface transfer surface T11. As shown in FIG. 8B, the lens 10 molded with the molding die 100 of FIG. 8A has R-shaped chamfered portions 10f formed on all four sides of the tip surface S11.

[Fifth Embodiment]
The lens according to the fifth embodiment will be described below. The lens or the like of the fifth embodiment is a partial modification of the lens or the like of the first embodiment, and parts not specifically described are the same as the lens or the like of the first embodiment.

  As shown in FIGS. 9 (A) and 9 (B), in the movable mold 12, the tip surfaces of the four protruding pins 31 are exposed on the flat surface transfer surface T6. An air vent EV is formed on the flat surface transfer surface T6 at a position opposite to the protrusion transfer surface 12b. That is, the air vent EV exists at a position closer to the axis AX than the outer peripheral side surface transfer surface T5 and at a position offset from the axis AX to the opposite gate side. The air vent EV is formed by a rod 112 p provided separately from the protruding pin 31. The rod 112 p is inserted into a rod hole 112 d provided in the movable mold 12 and fixed so as to be embedded in the movable mold 12. The tip surface of the rod 112p is exposed on the flat surface transfer surface T6. The air vent EV communicates with the outside of the mold through a gap between the rod 112p and the rod hole 112d, that is, an air passage 112e around the rod 112p. By providing the air vent EV, it is possible to prevent the lens 10 from being defectively formed due to air remaining in the cavity CV even when the lens 10 having a shape whose thickness changes is formed.

  As shown in FIG. 9C, in the lens 10 of the present embodiment, the arrangement of the three leg portions 10d is shifted by 120 °, and the two leg portions 10d are arranged on the side far from the projection portion 10c. One leg 10d is disposed on the side close to 10c. In FIG. 9C, an air vent mark ES is formed between the two leg portions 10d far from the protrusion 10c. Note that in the movable mold 12 shown in FIG. 9A and the like, the air vent 112e of the air vent EV is a very small gap, so that almost no burrs are formed on the air vent trace ES.

  As described above, the present invention has been described based on the embodiment, but the present invention is not limited to the above embodiment. For example, in the above embodiment, the shape and size of the lens 10 can be changed as appropriate.

  In the said embodiment, the curvature of R shape of the chamfering part 10f provided in the front end surface S11 of the projection part 10c can be changed suitably. For example, as shown in FIGS. 10 (A) and 10 (B), the curvature of the R shape may be made larger and the tip surface S11 may be spherical. Further, corners other than the protrusion 10c may be chamfered.

  In the above embodiment, the three leg portions 10d are provided. However, if the lens 10 is stable, four or more leg portions 10d may be provided. In addition, the position of the leg 10d can be changed as appropriate.

  In the above embodiment, the nozzle portion 21 extends in a direction perpendicular to the mold matching surface PP, and the injection direction of the molten resin from the nozzle end 21a is parallel to the movable direction AB of the movable mold 12. Thus, being parallel to the movable direction AB is not strictly, and the injection direction of the molten resin may be slightly inclined with respect to the movable direction AB of the movable mold 12. Further, the injection direction of the molten resin may be perpendicular to the movable direction AB of the movable mold 12.

  In the above embodiment, the molding die 100 is provided with a plurality of first and second transfer surfaces 12a and 11a, but may be provided one by one.

  DESCRIPTION OF SYMBOLS 10 ... Lens, 10a ... Optical part, 10b ... Outer peripheral part, 10c ... Projection part, 10d ... Leg part, 10f ... Chamfering part, 10g ... Recessed part, 11 ... Fixed metal mold, 11b, 12b, 111b ... Projection transfer surface, 12 ... movable mold, 12c ... corner, 20 ... hot runner mechanism, 21 ... nozzle part, 21a ... nozzle end, 30 ... ejection mechanism, 31 ... ejection pin, 40 ... pinpoint gate mechanism, 41 ... gate, 41a ... tip 100 ... Molding mold, AX ... Axis, CV ... Cavity, GS ... Gate cut trace, OA ... Optical axis, PP ... Molding surface, S1, S2 ... Optical surface, S11 ... Front end surface, S3, S4 ... Outer peripheral surface S5 ... outer peripheral side surface, S6 ... flat surface, S7, S8, S9, S10 ... projection surface, T1 ... optical surface transfer surface, T10 ... projection transfer surface, T11 ... tip Surface transfer surface, T12 ... Leg transfer surface, T2 ... Optical surface transfer surface, T3, T4 ... Outer surface transfer surface, T5 ... Outer surface transfer surface, T6 ... Flat surface transfer surface, T7, T8, T9, T10 ... Projection Transfer surface

Claims (12)

A lens manufactured by a molding die for injection molding using a pinpoint gate mechanism or a hot runner mechanism,
An optical unit;
An outer peripheral part extending around the optical part;
A protrusion protruding in the outer peripheral direction from the outer peripheral side surface of the outer peripheral portion;
Have
The tip surface away from the outer peripheral side surface of the protrusion has four sides as outer edges of the tip surface,
At least three sides of the four sides have an R-shaped chamfered portion.   2. The lens according to claim 1, wherein all of the four sides of the tip surface of the protrusion have an R-shaped chamfer.   The lens according to claim 1, wherein the lens has a center of gravity closer to the protrusion than the optical axis of the optical unit. The protrusion has a pair of protrusion surfaces perpendicular to the optical axis of the optical part,
4. The lens according to claim 1, wherein one projection surface of the pair of projection surfaces has a gate cut mark. 5. The protrusion has a pair of protrusion surfaces perpendicular to the optical axis of the optical part,
Of the pair of protrusion surfaces, one protrusion surface has a recess,
The lens according to claim 1, wherein the concave portion has a gate cut mark. Having a pair of optical surfaces;
The lens according to any one of claims 1 to 5, wherein one of the pair of optical surfaces has a convex shape. A pinpoint gate mechanism or a hot runner mechanism for manufacturing a lens having an optical part, an outer peripheral part extending around the optical part, and a protruding part protruding in an outer peripheral direction from an outer peripheral side surface of the outer peripheral part was used. A mold for injection molding,
A first mold and a second mold;
At least one of the first mold and the second mold has a concave protrusion transfer surface that forms the protrusion,
A molding die characterized in that at least three corners of the four corners on the tip side of the projection transfer surface have an R shape with the first and second molds closed.   The lens according to claim 7, wherein all of the four corners have an R shape.   The molding die according to claim 7 or 8, wherein a tip of the gate is provided on a die mating surface of the first and second molds.   9. The molding die according to claim 7, wherein a tip of the gate is provided at a position shifted to a die side opposite to the die-mating surfaces of the first and second dies. The first and second molds each have an optical surface transfer surface that forms a pair of optical surfaces of the lens,
11. The molding die according to claim 7, wherein one of the pair of optical surface transfer surfaces of the first and second molds has a concave shape. 11. .   A method for producing a lens, comprising producing a lens using the molding die according to any one of claims 7 to 11.

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