JP2011245735A - Method of manufacturing led lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing an LED lens which allows a resin to approximately uniformly flow in a mold and can prevent the occurrence of a weld.SOLUTION: When filling a resin in a mold space corresponding to the shape of the LED lens 50, the difference of a filling speed of the resin between a body space corresponding to a lens portion 60 having a comparatively thick wall thickness and an outer peripheral portion space corresponding to a lens outer peripheral portion 70 having a comparatively thick thickness becomes small by providing a step of making the injection speed lower than the injection speed at the starting of injection. The resin is suppressed from excessively turning around the space of the outer peripheral portion before being filled in the space of the body, and can be prevented from being filled in such a manner that the resin turning around flows back to the side of a lens portion 60. Therefore, the resin approximately uniformly flows in a mold space in the approximate uniform direction, and the occurrence of the weld can be prevented in a molded LED lens 50, and the defective appearance, deterioration of the optical characteristic, and deterioration of heat resistance of the LED lens 50 can be prevented thereby.

Description

  The present invention relates to a method for manufacturing an LED lens having a lens surface for correcting light flux, and more particularly to a method for manufacturing an LED lens molded by an injection molding machine.

  There is a method of manufacturing a lens by injection molding using a mold having a special shape (see, for example, Patent Document 1). In this lens manufacturing method, the mold has a shape close to a rectangle on the opposite side of the gate, thereby making the resin flow uniform during molding and preventing the lens from being welded.

JP 2008-234740 A

  A lens manufactured by a manufacturing method such as Patent Document 1 is a relatively small objective lens for an optical pickup device. If the shape of the inner surface of a molding die is devised, the injection speed of resin during molding is increased. Also, the resin can be produced by flowing the resin into the mold substantially uniformly. However, a relatively large lens such as an LED lens for illumination, particularly a thin plate-like lens having a plurality of lens surfaces arranged two-dimensionally, specifically, the lens portion is thick and the lens outer peripheral portion is thin. When manufacturing the thing of a simple shape, it is difficult for the manufacturing method like patent document 1 to flow resin into a type | mold substantially uniformly. Moreover, if the diameter of the molded lens product is large, the temperature difference between the inflowing resins increases, and if the resin is not uniformly filled, welds (resin flow confluence) are likely to occur. Further, the resin that has flowed into the mold tends to go around the lens outer peripheral portion that is thinner than the thick lens portion, the lens portion becomes unfilled, air is left in the mold, and welds are likely to occur. When the weld is generated in the lens portion, it may cause a poor appearance, deterioration of optical characteristics, deterioration of heat resistance, and the like.

  Accordingly, an object of the present invention is to provide an LED lens manufacturing method capable of preventing the occurrence of welds by allowing resin to flow into the mold substantially uniformly.

In order to solve the above problems, an LED lens manufacturing method according to the present invention is a manufacturing method by injection molding of an LED lens having a lens surface on at least one surface, the LED lens diameter Φ1 and the lens surface diameter Φ2. The ratio (Φ2 / Φ1) to
0.013 ≦ (Φ2 / Φ1) ≦ 0.67
The number of lens surfaces is in the range of 1 to 30, and when filling the resin into the mold corresponding to the shape of the LED lens, the injection speed is made slower than the injection speed at the start of injection Have Here, the injection speed of the resin is based on, for example, the injection speed at the nozzle tip of a molding apparatus for injection molding.

  In the manufacturing method of the LED lens, when a resin corresponding to the shape of the LED lens is filled with a resin, by providing a step of making the injection speed slower than the injection speed at the start of injection, for example, a relatively thick wall. A difference in resin filling speed between a mold portion corresponding to a lens portion having a lens surface and a mold portion corresponding to a portion other than a relatively thin lens surface (lens outer peripheral portion) is reduced. This suppresses excessive wrapping around the mold part corresponding to the lens outer periphery before the resin is sufficiently filled into the mold part corresponding to the lens part, and whether the sneak around resin flows back on the lens part side. It is possible to prevent the filling. Therefore, it is possible to prevent the resin from flowing into the mold in a substantially uniform direction in a substantially uniform direction and to generate welds in the LED lens, and to prevent the appearance defect of the LED lens, the deterioration of optical characteristics, and the deterioration of heat resistance. it can.

  According to a specific mode or aspect of the present invention, the injection speed is slowed at a timing when the resin is filled in at least a position corresponding to the lens surface in the mold. In this case, since the resin corresponding to the lens portion is filled almost uniformly and gently, it is possible to prevent air from remaining on the lens surface.

  According to another aspect of the present invention, the resin injection speed in the step of slowing the injection speed is 1.0 (mm / sec) or more and 4.0 (mm / sec) or less. In this case, by setting the resin injection speed within the above range, the resin can be uniformly filled in the lens portion without leaving air.

According to still another aspect of the present invention, the resin filling amount in the step of slowing the injection speed is 0.5 (cm ³ / sec) or more and 2 (cm ³ / sec) or less.

  According to still another aspect of the present invention, the diameter Φ1 of the LED lens is in the range of 30 (mm) ≦ Φ1 ≦ 150 (mm). The resin cooling can be easily controlled by making the diameter Φ1 of the LED lens smaller than 150 mm. In addition, when the diameter Φ1 of the LED lens is larger than 30 (mm), the effect of providing a step of slowing the resin injection speed is enhanced.

  According to still another aspect of the present invention, the diameter Φ2 of the lens surface is in the range of 2 (mm) ≦ Φ2 ≦ 20 (mm). If the diameter Φ2 of the lens surface exceeds 20 (mm), the tendency for the portion corresponding to the lens surface to become the main part in the mold increases, and the problem of uneven filling is less likely to occur. When the diameter Φ2 of the lens surface is larger than 2 (mm), the effect of providing a step of slowing the resin injection speed is enhanced.

  According to still another aspect of the present invention, the absolute value of the radius of curvature R of the lens surface is in the range of 0.5 (mm) ≦ R ≦ 20 (mm). When the radius of curvature R exceeds 20 (mm), the lens surface becomes deeper and it is difficult to obtain a sufficient effect even with the method of the present invention. When the radius of curvature R is larger than 0.5 (mm), the resin The effect of providing a step of slowing the injection speed of the is increased.

  According to still another aspect of the present invention, polycarbonate is used as a raw material. In this case, polycarbonate has a lower viscosity than acrylic and can be efficiently filled into the mold.

(A) is a top view of the LED lens of embodiment, (B) is a side view of an LED lens. It is sectional drawing of the shaping die for shape | molding a LED lens. (A) is a conceptual diagram explaining the flow of the resin at the time of shaping | molding of an LED lens, (B) is a comparative example of (A). It is a front view explaining the shaping | molding apparatus for shape | molding a LED lens. It is a flowchart explaining operation | movement of the shaping | molding apparatus shown in FIG. It is a figure explaining the injection speed of the resin in the injection device shown in FIG. (A), (B) is a figure explaining the relationship between the injection speed of resin, and the flow of resin.

The manufacturing method of the LED lens which is one Embodiment of this invention is demonstrated referring drawings.
As shown in FIG. 1, the LED lens 50 manufactured by the manufacturing method is a lens for an LED illumination device, and includes a lens unit 60 for adjusting a light beam and a lens outer peripheral unit 70 that supports the lens unit 60 from the periphery. . The LED lens 50 is a single part molded from a plastic material, specifically, polycarbonate, and the lens portion 60 and the lens outer peripheral portion 70 are integrated. The LED lens 50 has a substantially circular outline in plan view. Note that the LED lens 50 includes a gate portion 80 on a part of the outer peripheral side surface SD of the lens outer peripheral portion 70. The gate portion 80 is a cut trace of a portion corresponding to a resin inlet at the time of injection molding.

  As shown in FIG. 1A, a plurality of lens portions 60, specifically nine, are arranged in substantially the same plane in the vicinity of the center portion of the lens outer peripheral portion. As shown in FIGS. 1A and 1B, the lens unit 60 has a lens surface 60a on one surface side (for example, a light incident side) of the LED lens 50 or the lens outer peripheral portion 70, and the other surface side ( For example, a flat surface 60b is provided on the light emission side. The lens surface 60a has a substantially circular outline in plan view. The diameter Φ2 of the lens surface 60a is 2 (mm) ≦ Φ2 ≦ 20 (mm), and specifically about 10 (mm). The absolute value of the curvature radius R is 0.5 (mm) ≦ R ≦ 20 (mm), specifically about 5 (mm). Each lens surface 60a has a central convex surface 60c that is coaxial with the lens surface 60a and has substantially the same radius of curvature at the center thereof. The central convex surface 60c is recessed from the periphery, and a step is formed around the center convex surface 60c.

  The lens outer peripheral portion 70 is a substantially flat plate-like body and extends perpendicularly to the optical axis OA of the lens portion 60. The lens outer peripheral portion 70 includes a first lens outer peripheral surface 70a on the lens surface 60a side and a second lens outer peripheral surface 70b on the opposite side to the lens surface 60a. The lens outer peripheral portion 70 constitutes the main contour of the LED lens 50 and has a substantially circular contour in plan view. The diameter Φ1 of the lens outer peripheral portion 70 is 30 (mm) ≦ Φ1 ≦ 150 (mm), and specifically about 80 (mm).

  In the above, the ratio of the diameter Φ2 of the lens surface 60a to the diameter Φ1 of the lens outer peripheral portion 70 is 0.013 ≦ (Φ2 / Φ1) ≦ 0.67, preferably 0.067 ≦ (Φ2 / Φ1) ≦ 0. 13

  The gate portion 80 is a part of the side surface SD of the lens outer peripheral portion 70 and is provided in a direction perpendicular to the optical axis OA with respect to the lens surface 60a. The gate portion 80 is formed at one place on the side surface SD side of the LED lens 50, so that not only the mold for injection molding can be simplified but also a single resin flow can be easily formed. Yes.

In the following, a molding die for manufacturing the LED lens 50 shown in FIG. 1 will be described with reference to FIG.
As shown in FIG. 2, the molding die 40 includes a fixed die 41 and a movable die 42. Here, although the details will be described later, the movable mold 42 can reciprocate in the AB direction. The movable lens 42 is moved toward the fixed mold 41, the molds 41 and 42 are matched with the parting surfaces PS1 and PS2, and the mold is clamped to mold the LED lens 50 shown in FIG. A mold space CV is formed. A gate GP communicating with the mold space CV is formed in a part of the periphery of the mold space CV.

  The mold space CV includes a main body space CV1 sandwiched between the first transfer surface S1 and a part of the third transfer surface S3, and an outer peripheral space CV2 sandwiched between the second and third transfer surfaces S2 and S3. With. Here, the first transfer surface S1 is for forming the lens surface 60a of the LED lens 50 shown in FIG. The second transfer surface S2 is for forming the first lens outer peripheral surface 70a of the LED lens 50 shown in FIG. The third transfer surface S3 is for forming the flat surface 60b and the second lens outer peripheral surface 70b of the LED lens 50.

Hereinafter, the flow of resin in the mold space CV shown in FIG. 2 will be described with reference to FIG.
In FIG. 3A, a curved portion 90 constituting the contour of the mold space CV corresponds to the outer edge portion 50a of the LED lens 50 shown in FIG. For convenience, the first transfer surface S1 for transferring the lens surface 60a is named transfer surfaces S1a, S1b, S1c, S1d, S1e, S1f, S1g, S1h, S1i in order from the side closer to the gate GP. The broken line RF indicates the beginning of the resin being filled at a certain moment, and the thick arrow indicates the direction in which the resin flows.

  As shown in FIG. 3A, the resin flows from the gate GP substantially parallel to the diameter direction DD of the curved portion 90 of the mold space CV. The resin flowing in from the gate GP flows in while spreading laterally in the space surrounded by the curved portion 90, that is, the mold space CV. At this time, the broken line RF at the top of the resin is in the order of the transfer surface S1a, transfer surface S1b, S1c, transfer surface S1d, S1e, S1f, transfer surface S1g, S1h, transfer surface S1i of the lens surface 60a near the gate GP. It moves while filling the mold space CV sequentially. Here, in this embodiment, the manufacturing method of the LED lens 50 is the resin of the injection device 16 (see FIG. 4) described later at the timing when the resin flowing into the mold space CV is filled in the position of the first main body space CV1. A step of slowing the injection speed. Therefore, the broken line RF is in a substantially parallel state at the positions of the transfer surfaces S1a, S1b, S1c, S1d, S1e, S1f, S1g, S1h, and S1i. That is, when the inflow speed at each transfer surface S1a, S1b, S1c, S1d, S1e, S1f, S1g, S1h, S1i is relatively slow, as shown in FIG. It flows from the gate GP so as to spread laterally in the diameter direction DD of the mold space CV, and is stably filled into the main body space CV1 sandwiched between the first transfer surface S1 and a part of the third transfer surface S3. On the other hand, when the inflow speed at each of the transfer surfaces S1a, S1b, S1c, S1d, S1e, S1f, S1g, S1h, and S1i is relatively high, as shown in FIG. It becomes easier to go around the outer peripheral space CV2 narrower than CV1 first, and a portion where the main body space CV1 is not filled appears. For this reason, in this case, air remains in the main body space CV1, and the resin that has first entered the outer peripheral space CV2 flows backward into the main body space CV1 and collides with the resin flowing into the main body space CV1 from the positive direction (gate GP side). To do. As a result, a weld (resin merging portion) that extends across the molded LED lens 50, particularly the lens portion 60, is likely to occur. If the weld occurs in the lens unit 60, it may cause a poor appearance, deterioration of optical characteristics, deterioration of heat resistance, and the like.

Hereinafter, a molding apparatus for manufacturing the LED lens 50 shown in FIG. 1 will be described.
As shown in FIG. 4, the molding apparatus 100 includes an injection molding machine 10 as a main body that actually produces a resin molded product by injection molding, and a control apparatus that comprehensively controls the operation of each part constituting the injection molding machine 10. 30.

  The injection molding machine 10 includes a fixed platen 11, a movable platen 12, a mold clamping plate 13, an opening / closing drive device 15, and an injection device 16. The injection molding machine 10 sandwiches a fixed mold 41 and a movable mold 42 constituting the molding mold 40 shown in FIG. It can be molded by tightening.

  The fixed platen 11 is fixed to the center of the support frame 14. The stationary platen 11 detachably supports the stationary mold 41. Note that the fixed platen 11 is fixed to the mold clamping plate 13 via a tie bar so that it can withstand the pressure of mold clamping during molding.

  The movable platen 12 is supported by the linear guide 15a so as to be movable back and forth with respect to the fixed platen 11. The movable platen 12 detachably supports the movable mold 42. In addition, an ejector 45 is incorporated in the movable platen 12. The ejector 45 is for extruding a resin molded product to be separated from the movable mold 42 at the time of mold release from the movable mold 42 to the fixed mold 41 side.

  The mold clamping machine 13 is fixed to the end of the support frame 14. The mold clamping machine 13 supports the movable board 12 from the back via the power transmission part 15d of the opening / closing drive device 15 at the time of mold clamping.

  The opening / closing drive device 15 includes a linear guide 15a, a power transmission unit 15d, and an actuator 15e. The linear guide 15 a supports the movable platen 12 and enables the movable platen 12 to smoothly reciprocate with respect to the advancing and retreating direction with respect to the fixed platen 11. The power transmission unit 15d expands and contracts in response to the driving force from the actuator 15e. As a result, the movable platen 12 can move toward and away from the mold clamping plate 13 freely, and as a result, the movable platen 12 and the fixed platen 11 can be moved closer to or away from each other. The mold 41 and the movable mold 42 can be clamped or separated.

The injection device 16 includes a cylinder 16a, a raw material storage unit 16b, a screw driving unit 16c, a resin injection end 16d, and a screw 16e. The injection device 16 operates at an appropriate timing under the control of the injection control unit of the control device 30 and can inject the molten resin from the resin injection end 16d in a temperature-controlled state. The injection device 16 brings the resin injection end 16d into contact with a sprue bush (not shown) provided on the stationary platen 11 in a state where the fixed mold 41 and the movable mold 42 are clamped, and the cylinder toward the mold space CV side. The molten resin in 16a can be supplied at a desired timing and pressure. The cylinder 16a is connected to the raw material reservoir 16b, and receives supply of resin from the raw material reservoir 16b at an appropriate timing and amount. Further, the screw 16e is advanced by the screw driving unit 16c, whereby the liquid resin in the cylinder 16a can be injected from the resin injection end 16d at a desired pressure and flow rate. That is, the inflow speed of the resin flowing into the mold space CV is controlled based on the resin injection speed at the resin injection end 16d, that is, the nozzle tip. Here, as described above, in the manufacturing method of the LED lens 50 according to the present embodiment, the resin flowing into the mold space CV is positioned at the first body space CV1 (the transfer surface S1a of the first transfer surface S1 in FIG. 3). The step of slowing the resin injection speed at the resin injection end 16d at the timing of filling at a timing corresponding to the position (1) of FIG. Thus, the injection speed when the injection of the resin is delayed is 1.0 (mm / sec) or more and 4.0 (mm / sec) or less. Here, since the cross-sectional area of the resin injection end 16d is 5 (cm ² ), the filling amount of the resin in the process is 0.50 (cm ³ / sec) or more and 2.0 (cm ³ / sec). It is as follows.

  The control device 30 includes a mold temperature control unit for the molds 41 and 42, an open / close control unit for the open / close drive device 15, an injection control unit for the injection molding machine 10, an ejector control unit for the ejector 45, and the like. ing.

Hereinafter, the operation of the molding apparatus 100 shown in FIG. 4 will be described with reference to FIG.
First, the operation of the mold temperature control unit of the control device 30 heats the surfaces of both molds 41 and 42 to a temperature suitable for molding (step S11).

  Next, the opening / closing drive device 15 is operated by the opening / closing control unit of the control device 30, and the movable platen 12 is moved forward to start mold closing (step S12). By continuing the closing operation of the opening / closing driving device 15, the movable platen 12 moves to the fixed platen 11 side to the die contact position where the fixed die 41 and the movable die 42 come into contact with each other, thereby completing the die closing (step S13). ) By further continuing the closing operation of the opening / closing drive device 15, mold clamping is performed to clamp the fixed mold 41 and the movable mold 42 with a necessary pressure (step S14).

  Next, in the injection molding machine 10, the injection device 16 is operated by the injection control unit of the control device 30, and is necessary in the mold space CV between the fixed mold 41 and the movable mold 42 that are clamped. An injection for injecting the molten resin at a pressure, a flow rate or the like is performed (step S15). At this time, the injection device 16 adjusts and changes the injection speed of the resin (step S16). That is, as shown in FIG. 6, the injection device 16 injects the resin toward the mold space CV by changing the injection speed in the first injection stage, the second injection stage, and the third injection stage. Here, the first injection stage is a stage where the resin in the mold space CV reaches from the gate GP to the front of the main body space CV1 closest to the gate GP, and the second injection stage is a stage where the resin is in the main body space. The third injection stage is a stage in which the resin fills the main body space CV1 and then fills the remaining mold space CV. As shown in FIG. 6, in the first injection stage, the resin is injected at a relatively high injection speed and flows into the mold space CV. At this time, the top of the resin in the mold space CV moves to the front of the main body space CV1 closest to the gate GP, as indicated by a broken line RF shown in FIG. Next, in the second stage, the injection speed of the resin sharply decreases at a predetermined rate, specifically, the target value is 1.0 (mm / sec) or more and 4.0 (mm / sec) or less. . At this time, the resin in the mold space CV slowly flows into the main body space CV1 closest to the gate GP as described above. Next, in the third stage, the injection device 16 is in a state where the injection speed is maintained at a target value of 1.0 (mm / sec) or more and 4.0 (mm / sec) or less. At this time, the resin in the mold space CV fills the main body space CV1 closest to the gate GP, then sequentially fills the main body space CV1 corresponding to the other lens surface 60a, and fills all the main body spaces CV1. Is completed. Thereafter, the injection molding machine 10 maintains the resin pressure in the mold space CV for a certain period. At this time, the mold temperature CV and the like (see FIG. 2) in the molding die 40 are appropriately heated by the mold temperature control unit of the control device 30, and the molten resin can be quickly introduced into the mold space CV. And moderate decooling of the resin in the mold space CV can be achieved.

  After the molten resin is introduced into the mold space CV, the molten resin in the mold space CV is gradually cooled by heat dissipation, so that it waits for the molten resin to solidify and complete molding with the cooling (step S17). .

  Next, in the injection molding machine 10, the opening / closing drive device 15 is operated by the opening / closing control unit of the control device 30 to perform mold opening for retracting the movable platen 12 (step S18). Along with this, the movable mold 42 moves backward, and the fixed mold 41 and the movable mold 42 are separated. As a result, the molded product including the LED lens 50 is released from the fixed mold 41 while being held by the movable mold 42.

  Next, in the injection molding machine 10, the ejector 45 is operated by the ejector control unit of the control device 30 so that the molded product including the LED lens 50 is ejected. Thereby, the whole mold release is performed about the molded product containing the LED lens 50 (step S19).

  Finally, a take-out device (not shown) is operated to carry out a molded product including the LED lens 50 completely released from the movable mold 42 to the outside (step S20).

  As apparent from the above description, according to the manufacturing method of the LED lens 50 of the present embodiment, when the resin is filled into the mold space CV corresponding to the shape of the LED lens 50, the injection speed at the start of injection is determined. Also, by providing a step of slowing the injection speed, the difference in resin filling speed between the main body space CV1 corresponding to the relatively thick lens portion 60 and the outer peripheral space CV2 corresponding to the relatively thin lens outer peripheral portion 70 is obtained. Becomes smaller. Accordingly, it is possible to prevent the resin from being excessively circulated into the outer peripheral space CV2 before the resin is filled into the main body space CV1, and to prevent the wrapping resin from being charged as if it is flowing backward to the lens unit 60 side. Can do. For this reason, the resin flows into the mold space CV in a substantially uniform direction in a substantially uniform direction to prevent welds from being formed on the molded LED lens 50, and the LED lens 50 has a poor appearance, deteriorated optical characteristics, and heat resistance. Can be prevented.

Hereinafter, the relationship between the injection speed of the injection device 16 and the resin flow will be specifically described.
FIG. 7A shows a specific example of a change in injection speed when the injection device 16 is used, and FIG. 7B shows a comparative example of FIG. 7A, that is, injection when the injection speed is not slowed down. Indicates the change in speed.

  As shown in FIG. 7A, in the first injection stage, the injection speed of the resin changes from 20 (mm / sec) to 15 (mm / sec). Next, in the second injection stage, the injection speed of the resin changes so as to rapidly decrease from 15 (mm / sec) to 1.5 (mm / sec). Referring to FIG. 3A already described, the leading broken line RF of the resin closest to the gate GP indicates the state of switching from the first injection stage to the second injection stage. After the second injection stage, in the third injection stage, the injection speed of the resin changes from 1.5 (mm / sec) to 4.0 (mm / sec) to 3.0 (mm / sec). At this time, the resin flows in the mold space CV in a uniform and uniform direction as indicated by a thick arrow shown in FIG. 3A, and fills the mold space CV.

  On the other hand, as shown in FIG. 7B, in the comparative example, the injection speed of the resin has changed from 30 (mm / sec) to 20 (mm / sec) and 10 (mm / sec). The injection speed is relatively faster than the second and third injection stages in FIG. In this case, referring to FIG. 3B already described, the resin is excessively spilled first into the outer peripheral space CV2 narrower than the main body space CV1. For this reason, the resin that wraps around first fills as if it flows backward on the lens unit 60 side, and collides with the resin flowing into the main body space CV1 from the forward direction (gate GP side).

  Although the present invention has been described based on the above embodiments, the present invention is not limited to the above embodiments, and various modifications are possible. For example, in the above-described embodiment, the contours of the lens unit 60 and the lens outer peripheral unit 70 are circular, but may be various shapes such as an ellipse and a quadrangle. Further, the sizes of the lens unit 60 and the lens outer peripheral unit 70 can be changed as appropriate.

  In the above embodiment, the arrangement of the lens unit 60 can be changed as appropriate in consideration of the effect of illumination.

  In the above embodiment, nine lens portions 60 are provided, but the number of arrangement can be changed from one to thirty.

  In the above embodiment, the lens surface 60a is provided only on one surface of the lens outer peripheral portion 70 (first lens outer peripheral surface 70a), but the lens surface is provided on the other surface (second lens outer peripheral surface 70b). Also good. In this case, the lens surface 60a provided on one surface has a smaller radius of curvature than the lens surface provided on the other surface, and the diameter Φ2 of the lens surface 60a is 2 (mm) ≦ Φ2 ≦ 20 (mm). Become.

  In the above embodiment, the step of slowing the resin injection speed at the resin injection end 16d is not limited to when the resin flows into the position of the first main body space CV1, but for example, the resin is connected to the gate GP and the first main body. It may be performed when it flows into a position between the space CV1 or when the resin flows into a position immediately after flowing into the first main body space CV1.

  DESCRIPTION OF SYMBOLS 10 ... Injection molding machine, 11 ... Fixed platen, 12 ... Movable platen, 15 ... Opening / closing drive device, 16 ... Injection device, 16d ... Resin injection end, 30 ... Control device, 40 ... Molding die, 41 ... Fixed die, 42 ... movable mold, 50 ... lens, 60 ... lens part, 60a ... lens surface, 70 ... lens outer peripheral part, 80 ... gate part, 100 ... molding device, CV ... mold space, CV1 ... main body space, CV2 ... outer peripheral part Space, GP ... Gate, OA ... Optical axis, PS1, PS2 ... Parting surface

Claims (8)

A manufacturing method by injection molding of an LED lens having a lens surface on at least one surface,
The ratio (Φ2 / Φ1) between the diameter Φ1 of the LED lens and the diameter Φ2 of the lens surface is
0.013 ≦ (Φ2 / Φ1) ≦ 0.67
In the range of
The number of the lens surfaces is 1 or more and 30 or less,
A method for producing an LED lens, comprising a step of lowering an injection speed from an injection speed at the start of injection when filling a mold corresponding to the shape of the LED lens with a resin.   2. The method of manufacturing an LED lens according to claim 1, wherein an injection speed is slowed at a timing when a resin is filled at least in a position corresponding to the lens surface in the mold.   3. The resin injection speed in the step of slowing down the injection speed is 1.0 (mm / sec) or more and 4.0 (mm / sec) or less. The manufacturing method of the LED lens of one term. ^3. The resin filling amount in the step of slowing down the injection speed is 0.5 (cm ³ / sec) or more and 2 (cm ³ / sec) or less. The manufacturing method of the LED lens of one term.   The diameter Φ1 of the LED lens is in a range of 30 (mm) ≦ Φ1 ≦ 150 (mm), and the manufacturing method of the LED lens according to any one of claims 1 to 4.   6. The method of manufacturing an LED lens according to claim 1, wherein a diameter Φ2 of the lens surface is in a range of 2 (mm) ≦ Φ2 ≦ 20 (mm).   7. The LED according to claim 1, wherein an absolute value of a radius of curvature R of the lens surface is in a range of 0.5 (mm) ≦ R ≦ 20 (mm). Lens manufacturing method.   The polycarbonate is used as a raw material, The manufacturing method of the LED lens as described in any one of Claim 1- Claim 7 characterized by the above-mentioned.

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