JP2015003406A - Forming die and light flux control member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a forming die for forming a light flux control member controlling light distribution of light emitted from a light source which has a gas vent function and causes little influence on the light distributing characteristics of the light flux control member even when the part having the gas vent function is transferred.SOLUTION: A forming die includes a lens surface formation part body 120 which includes a plurality of lens surface formation part pieces 126 divided by planes passing the center point of a transfer surface 121 and a holder 140 which fixes the plurality of lens surface formation part pieces 126, and the individual lens surface formation part 126 has a divided transfer surface 121a which is formed with a plurality of concave parts 125 including an arc-shaped trough line with the center point of the transfer surface 121 as the center.

Description

  The present invention relates to a forming die for forming a light flux controlling member that controls light distribution of light emitted from a light source. Moreover, this invention relates to the light beam control member shape | molded using the said shaping | molding die.

  In recent years, from the viewpoint of energy saving and downsizing, a light emitting device (LED flash) using a light emitting diode (hereinafter also referred to as “LED”) as a light source has been used as a light emitting device for an imaging camera. As such a light emitting device, a combination of an LED and a lens including unevenness for controlling the light distribution of light emitted from the LED is well known.

  The lens mounted on the imaging camera can be manufactured by injection molding using a resin as a material. In the manufacture of a lens by injection molding, the gas present in the cavity or the gas generated from the molten resin filled in the cavity may remain in the central portion or the uneven portion of the lens. Residual gas in the cavity can cause heat generation due to adiabatic compression at the time of molding and cause burning, or can adhere to the inner surface of the mold and cause molding defects. Therefore, in order to obtain a lens as designed, the mold needs a gas vent function for discharging the residual gas in the cavity to the outside of the cavity.

  Patent Document 1 describes a mold having a gas vent function for manufacturing a lens by injection molding. FIG. 1 is a plan view of a mold member 10 constituting the mold described in Patent Document 1. FIG. The mold member 10 described in Patent Document 1 is composed of one piece. The mold member 10 includes a transfer portion 20 disposed in the center portion in plan view, an edge portion 30 disposed outside the transfer portion 20, and a concave groove 40 disposed from the transfer portion 20 to the edge portion 30. Have. A plurality of division surfaces 21 are arranged concentrically on the transfer unit 20. A step 22 is arranged at the boundary between the adjacent divided surfaces 21. The concave groove 40 is formed so that the width gradually increases from the center toward the outside in the transfer portion 20 and has a predetermined depth.

JP 2004-098538 A

  When a lens is molded by injection molding using the mold member 10 described in Patent Document 1 having a concave groove 40 having a predetermined size, the shape of the concave groove 40 is transferred to the lens as a convex portion. This convex portion may affect the light distribution characteristics of the lens. As a means for solving such a problem, it is conceivable to reduce the size of the concave groove 40 so that the concave groove 40 is not transferred as a convex portion to the lens. However, it is difficult to form a concave groove 40 having a gas vent function in a mold member with a processing machine so as not to be transferred as a convex portion on the lens.

  The present invention has been made in view of the above points, and is a mold having a gas vent function, and even if a portion functioning as a gas vent is transferred to the light beam control member, the light distribution characteristic of the light beam control member is almost the same. It aims at providing the shaping | molding die which does not have influence. Another object of the present invention is to provide a light flux controlling member molded using this mold.

  A molding die according to the present invention is a molding die having a transfer surface for molding a light beam control member for controlling the light distribution of light emitted from a light source, and is divided by a surface passing through the center point of the transfer surface. A mold body including a plurality of molded mold pieces, and a holder for fixing the plurality of mold mold pieces, each of the plurality of mold mold pieces having an arc shape centered on the center point. A configuration having a divided transfer surface in which a plurality of concave portions including valley lines is formed is adopted.

  A light flux controlling member according to the present invention is a light flux controlling member that controls light distribution of light emitted from a light source, and a plurality of annular convex portions formed by using the mold according to the present invention are concentric. A configuration having incident areas arranged in a shape is adopted.

  Since the mold according to the present invention has a very small gap between the mold pieces that can function as a gas vent, even if the gap is transferred and a convex portion is formed, the light distribution characteristics are hardly affected. The light flux controlling member can be formed.

2 is a plan view of a mold member described in Patent Document 1. FIG. 2 is a perspective view of a molding die according to Embodiment 1. FIG. 3A and 3B are diagrams showing the configuration of the mold main body. It is a disassembled perspective view of a shaping | molding die main body. 5A and 5B are diagrams showing the structure of the holder. 6A to 6D are diagrams showing the configuration of the light flux controlling member according to the first embodiment. 7A and 7B are diagrams showing a configuration of a mold according to the second embodiment. 8A and 8B are perspective views showing the configuration of the mold according to Embodiment 2. FIG. 5 is a partial enlarged cross-sectional view of a molding die according to Embodiment 2. FIG. 5 is a partial enlarged cross-sectional view of a molding die according to Embodiment 2. FIG.

  The mold according to the present invention has a mold piece used for manufacturing a light flux controlling member having a Fresnel lens portion by injection molding. The mold piece included in the mold according to the present invention is used to mold the incident region including the Fresnel lens portion.

  The mold according to the present invention includes a lens surface molding part main body (molding mold main body) composed of a plurality of lens surface molding part pieces (molding mold pieces) and a plurality of lens surface molding part main bodies as mold pieces. And a holder for fixing the lens surface molding part. Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.

[Embodiment 1]
(Configuration of the mold pieces that make up the mold)
2-5 is a figure which shows the structure of the metal mold | die piece 100 which comprises the shaping | molding die concerning Embodiment 1. FIG. FIG. 2 is a perspective view of the mold piece 100 constituting the mold according to the first embodiment. 3A is a plan view of the lens surface molding unit main body 120, and FIG. 3B is a side view of the lens surface molding unit main body 120. As shown in FIG. FIG. 4 is an exploded perspective view of the lens surface molding unit main body 120. FIG. 5A is a perspective view of the holder 140 as viewed from above, and FIG. 5B is a perspective view of the holder 140 as viewed from below. Hereinafter, in FIG. 2, the direction of the area where the transfer surface 121 is formed when viewed from the center of the mold piece 100 is “upper side”, and the direction of the area facing the transfer surface 121 when viewed from the center of the mold piece 100. Is described as “lower side”.

  As shown in FIG. 2, the mold piece 100 constituting the mold according to Embodiment 1 has a lens surface molding part main body (molding mold main body) 120 and a holder 140. In the present embodiment, the shape of the mold piece 100 is substantially rotationally symmetric (circularly symmetric) with the central axis CA1 as the rotation axis.

  As shown in FIGS. 3 and 4, the lens surface molding part main body 120 includes a plurality of lens surface molding part pieces (molding die pieces) 126. The external shape of the lens surface molding part main body 120 is a substantially cylindrical shape that is substantially rotationally symmetric with the central axis CA1 as a rotation axis.

  On the upper surface of the lens surface molding unit main body 120, a transfer surface 121 for molding the incident region (lens surface) 220 of the light flux controlling member 200 (see FIG. 6) is disposed. The shape of the transfer surface 121 is a substantially truncated cone shape (see FIG. 3B). In addition, a lens surface molding unit main body step 122 for fixing the lens surface molding unit main body 120 to the holder 140 is disposed below the lens surface molding unit main body 120.

  The lens surface molding portion 126 has a shape obtained by dividing the lens surface molding portion main body 120 by a dividing plane S1 passing through the central axis CA1 (a plane passing through the center point of the transfer surface 121). The number of lens surface molding part pieces 126 is not particularly limited. In the present embodiment, the number of lens surface molding pieces 126 is four, and the shape of the lens surface molding pieces 126 in a plan view is a sector shape with a central angle of 90 °. The four lens surface molding portion pieces 126 function as the lens surface molding portion main body 120 by combining the fan-shaped linear portions together in plan view so that the external shape becomes a substantially cylindrical shape.

  The lens surface molding piece 126 has a divided transfer surface 121a and a divided stepped portion 122a. The divided transfer surface 121 a is disposed on the upper surface of the lens surface molding part 126. The divided transfer surface 121 a is a part of the transfer surface 121. The divided transfer surface 121a functions as the transfer surface 121 by being combined with the divided transfer surfaces 121a of the other three lens surface molding portions 126 so that the shape in plan view becomes a substantially circular shape. The divided transfer surface 121a has an inner transfer region 123a and an outer transfer region 124a.

  The inner transfer region 123a is disposed on the center axis CA1 side. The inner transfer region 123 a is a part of the refracting portion molding region 123. The inner transfer region 123 a functions as the refractive portion molding region 123 by being combined with the inner transfer regions 123 a of the other three lens surface molding pieces 126. The cross-sectional shape of the inner transfer region 123a in a plane passing through the central axis CA1 is a straight line.

  The outer transfer region 124a is disposed on the outer side in the radial direction than the inner transfer region 123a. The outer transfer area 124 a is a part of the Fresnel lens part molding area 124. The outer transfer region 124 a functions as the Fresnel lens part molding region 124 by being combined with the outer transfer regions 124 a of the other three lens surface molding parts 126. The outer transfer region 124a has a plurality of arc-shaped divided recesses 125a centered on the central axis CA1. The plurality of divided recesses 125a having different diameters are arranged concentrically.

  The split recess 125a includes a first inclined surface 125b for shaping the fourth inclined surface 224a (incident surface of the Fresnel lens portion 222; described later) of the light flux controlling member 200, and a fifth inclined surface 224b (Fresnel of the light flux controlling member 200). The second inclined surface 125c for forming the reflecting surface of the lens unit 222 (described later) and the sixth inclined surface 224c of the light flux controlling member 200 (the surface connecting the incident surface and the reflecting surface of the Fresnel lens unit 222; described later) And a valley line 125e that is a boundary line between the first inclined surface 125b and the third inclined surface 125d. In the divided recess 125a, the first inclined surface 125b is disposed on the central axis CA1 side, the second inclined surface 125c is disposed radially outward, and the third inclined surface 125d includes the first inclined surface 125b and the second inclined surface 125c. Arranged to connect. The plan view shape of the valley line 125e is an arc shape with a central angle of 90 °.

  The division step portion 122 a is disposed below the lens surface molding portion 126. The division step portion 122 a is a part of the lens surface molding portion main body step portion 122. The division step portion 122 a functions as the lens surface molding portion main body step portion 122 by being combined with the division step portion 122 a of the other three lens surface molding portion pieces 126.

  As described above, the four lens surface molding portion pieces 126 are combined so that the fan-shaped straight portions are combined in a plan view so that the external shape becomes a substantially cylindrical shape, thereby forming the lens surface molding portion main body 120. Function. The transfer surface 121 of the lens surface molding unit main body 120 is formed by combining four divided transfer surfaces 121a. Further, the refractive part molding region 123 of the lens surface molding unit main body 120 is formed by combining four inner transfer regions 123a. Similarly, the Fresnel lens part molding region 124a of the lens surface molding unit main body 120 is formed by combining four outer transfer regions 124a. Furthermore, the concave portion 125 of the lens surface molding portion main body 120 is formed by combining four divided concave portions 125a. The lens surface molding part main body step 122 of the lens surface molding part main body 120 is formed by combining four divided step parts 122a.

  The external shape when the transfer surface 121 is viewed in plan is a circle. The transfer surface 121 includes a refracting part molding region 123 disposed at the center and a Fresnel lens part molding region 124 disposed outside the refracting part molding region 123. The external shape when the refracting portion molding region 123 is viewed in plan is a circle. The external shape when the Fresnel lens part molding region 124 is viewed in plan is an annular shape. The Fresnel lens part molding region 124 has a plurality of substantially annular recesses 125 having different diameters. The plurality of recesses 125 are arranged along a plurality of virtual circles arranged concentrically.

  The lens surface molding part body step 122 is a part for positioning the lens surface molding part body 120 with respect to the holder 140. The lens surface molding unit main body step 122 is disposed below the lens surface molding unit main body 120. The lens surface molding unit main body step 122 engages with the holder seat 142 of the holder 140.

  The holder 140 holds the lens surface molding part main body 120 (four lens surface molding part pieces 126). More precisely, the holder 140 holds the four lens surface molding part pieces 126 so that the four lens surface molding part pieces 126 can function as the lens surface molding part main body 120. As shown in FIG. 5, the shape of the holder 140 is a substantially cylindrical shape. A holder seat part 142 corresponding to the lens surface molding part main body step part 122 is formed in the lower part inside the holder 140 (see FIG. 5B). The lens surface molding part main body 120 (four lens surface molding part pieces 126) is inserted from the lower side of the holder 140, and the lens surface molding part main body step part 122 (four divided step parts 122a) is inserted into the holder seat part 142. The lens surface molding part main body 120 (four lens surface molding part pieces 126) is held by the holder 140 at an appropriate position.

  Thus, when the four lens surface molding pieces 126 are combined, a minute gap is formed between the lens surface molding pieces 126 adjacent to each other. The mold piece 100 according to the present embodiment can perform degassing at the time of injection molding using this gap. The gap reaches the edge from the center in the direction orthogonal to the central axis CA1, and reaches the bottom from the transfer surface 121 (upper end surface) in the direction along the central axis CA1. Therefore, when injection molding is performed using the mold piece 100 according to the present embodiment, the gas remaining in the concave portion 125 (divided concave portion 125 a) passes through the gap between the lens surface molding portion pieces 126. 100 can be discharged to the outside.

(Manufacturing method of mold pieces constituting the mold)
The mold piece 100 of the molding die according to the present embodiment, for example, applies plating to four raw material pieces to be the lens surface molding portion 126 (first step), and the four raw material pieces thus plated are used. It can be manufactured by fixing using the holder 140 (second step) and forming the transfer surface 121 on the raw material (four raw material pieces) fixed to the holder 140 (third step).

  In the first step, a raw material piece (metal piece) which is a material for forming the divided transfer surface 121a is prepared. The raw material piece is, for example, a metal piece obtained by dividing a cylinder made of metal into four on a plane including the central axis. Note that plating or vapor deposition may be performed before the divided transfer surface 121a is formed.

  In the second step, a combination of four raw material pieces (raw material) is inserted into the holder 140 from below. The raw material is fixed by the holder 140 by abutting the lens surface molding portion main body step 122 of the raw material against the holder seat 142 of the holder 140. At this time, the upper surface of the raw material (the surface to be the transfer surface 121) protrudes from the upper end surface of the holder 140. Note that the outer peripheral surface of the raw material and the inner peripheral surface of the holder 140 may be bonded using an adhesive or the like.

  In the third step, the refracting portion forming region 123 and the concave portion 125 are formed on the upper surface of the raw material protruding from the upper end surface of the holder 140 by, for example, lathe processing.

  With the above procedure, the mold piece 100 of the mold according to Embodiment 1 can be manufactured.

  The mold piece 100 according to the present embodiment can be manufactured by other procedures. For example, a cylindrical raw material to be the lens surface molding unit main body 120 is plated (first step), a transfer surface 121 is molded on the upper surface of the raw material (second step), and the lens surface molding unit main body 120 (transfer) (Raw material on which the surface 121 is formed) is divided into four on the dividing plane S1 (third step), and the four lens surface molding pieces 126 are fixed using the holder 140 (fourth step). Can also be manufactured. That is, after forming the transfer surface 121, the lens surface molding part main body 120 is divided, and the obtained four lens surface molding part pieces 126 are combined again using the holder 140 to manufacture the mold piece 100. Also good.

  When the light beam control member 200 is formed by injection molding using the mold piece 100 manufactured as described above, gas can flow into the gap between the lens surface molding pieces 126 adjacent to each other. The gas can be vented without performing the operation.

(Configuration of luminous flux control member)
FIG. 6 is a diagram showing a configuration of a light flux controlling member 200 formed using the mold piece 100 of the forming die according to the first embodiment. 6A is a bottom view of the light flux controlling member according to Embodiment 1, and FIG. 6B is a cross-sectional view taken along line AA shown in FIG. 6A. 6C is an enlarged view of a broken line portion shown in FIG. 6B, and FIG. 6D is a light flux control showing only the convex stripe 223 formed by transferring the gap between the lens surface molding portion 126. 3 is a plan view of a member 200. FIG.

  As shown in FIGS. 6A to 6C, the light flux controlling member 200 formed by using the mold piece 100 is positioned on the opposite side of the incident region 220 where the light emitted from the light source is incident, and the incident region 220, And an exit region 240 that emits light incident from the entrance region 220. A flange may be provided outside the surface that controls light. As described above, light flux controlling member 200 is formed by integral molding using mold piece 100 according to the first embodiment. The material of the light flux controlling member 200 is not particularly limited as long as it is a material that can transmit light having a desired wavelength. For example, the material of the light flux controlling member 200 is light transmissive resin such as polymethyl methacrylate (PMMA), polycarbonate (PC), and epoxy resin (EP), or glass.

  The incident area 220 is an area formed by the transfer surface 121. The incident region 220 allows light emitted from the light source to enter. The incident region 220 includes, in plan view, a refracting portion 221 located at the central portion, a Fresnel lens portion 222 located outside the refracting portion 221, and a convex strip 223 disposed from the refracting portion 221 to the Fresnel lens portion 222. Have

  The refraction part 221 is an area formed by the refraction part forming area 123. The refracting unit 221 causes a part of the light emitted from the light source to enter the light flux controlling member 200 and refracts the incident light toward the emission region 240. The shape of the refracting part 221 is a substantially conical shape.

  The Fresnel lens part 222 is an area formed by the Fresnel lens part molding area 124. The Fresnel lens unit 222 causes a part of the light emitted from the light source to enter the light flux controlling member 100 and reflects the incident light toward the emission region 240. The shape of the Fresnel lens part 222 is rotationally symmetric about the central axis CA2 of the light flux controlling member 100, and the Fresnel lens part 222 has a plurality of annular convex parts 224 arranged concentrically.

  As shown in FIG. 6C, each convex portion 224 has a fourth inclined surface 224 a that is an incident surface on which light emitted from the light source is incident, and light incident from the fourth inclined surface 224 a toward the emission region 240. A fifth inclined surface 224b that is a reflecting surface, a sixth inclined surface 224c that connects the fourth inclined surface 224a and the fifth inclined surface 224b, and a ridge line that is a boundary line between the fourth inclined surface 224a and the sixth inclined surface 224c. 224d respectively.

  The fourth inclined surface 224a is formed by the first inclined surface 125b of the mold piece 100, the fifth inclined surface 224b is formed by the second inclined surface 125c of the mold piece 100, and the sixth inclined surface 224c is formed by the metal mold. The mold piece 100 is molded by the third inclined surface 125d. The plan view shape of the ridge line 224d is substantially circular.

  As shown in FIG. 6D, the ridges 223 are formed by transferring the gaps between the lens surface molding portions 126, and are arranged so as to connect the center of the incident region 220 and the outermost projections 224. . The height of the ridge 223 depends on the width of the gap between the lens surface molding part 126 and the like. Therefore, if the gap between the lens surface molding part 126 is very small, the gap is not transferred in the injection molding, and the convex stripe 223 is not formed.

  The emission region 240 is a plane formed on the side opposite to the incident region 220. The emission area 240 is formed using another mold piece used in combination with the mold piece 100. The emission region 240 is formed so as to intersect with the central axis CA2 of the light flux controlling member 200. The emission region 240 is a rotationally symmetric surface with the central axis CA2 of the light flux controlling member 200 as the center. The emission region 240 emits the light incident from the refracting portion 221 and the light incident from the fourth inclined surface 224a of the Fresnel lens portion 222 and reflected by the fifth inclined surface 224b toward the irradiated region.

(effect)
As described above, the mold piece 100 according to the first embodiment is composed of the plurality of lens surface molding portions 126 and has a fine gap that can function as a gas vent. When the light flux controlling member 200 is manufactured by injection molding using the mold piece 100, even if the gap is transferred, the formed protrusion 223 is very small. There is almost no effect. In other words, according to the mold piece 100 according to the present embodiment, it is possible to manufacture the light flux controlling member with almost no influence on the light distribution characteristics while appropriately degassing.

[Embodiment 2]
(Configuration of the mold pieces that make up the mold)
The mold piece 300 according to the second embodiment is different from the mold piece 100 according to the first embodiment in the manner of dividing the lens surface molding unit main body 320. Therefore, the same components as those of the mold piece 100 according to Embodiment 1 are denoted by the same reference numerals, and the description thereof is omitted.

  7-10 is a figure which shows the structure of the die piece 300 which concerns on Embodiment 2. FIG. FIG. 7A is a plan view of the mold piece 300 according to Embodiment 2 in which the refractive part molding region 123 and the Fresnel lens part molding region 124 are omitted, and FIG. 7B is a cross-sectional view taken along the line BB shown in FIG. 7A. FIG. FIG. 8A is an exploded perspective view of the first lens surface molding portion 322, the second lens surface molding portion 323, and the third lens surface molding portion 324, and FIG. 8B is a partial view of the lens surface molding portion main body 320. FIG. 9 and 10 are partially enlarged sectional views of the mold piece 300. FIG.

  As shown in FIGS. 7 and 8, the lens surface molding part piece of the lens surface molding part main body 320 according to the second embodiment is further divided by a curved surface along an arc centering on the center point of the transfer surface 121. ing. Specifically, the lens surface molding part main body 320 according to the second embodiment includes a central lens surface molding part piece 321 having a refractive part molding region 123 and a central lens surface molding part piece from the lens surface molding part main body 320. It is composed of four lens surface molding pieces 326 obtained by dividing the portion excluding 321. Each lens surface molding part 326 is further divided into three in the radial direction by a curved surface along an arc centered on the center point of the transfer surface 121. That is, each lens surface molding part piece 326 includes a first lens surface molding part piece 322 arranged on the central axis CA1 side and a second lens surface molding part arranged radially outside the first lens surface molding part piece 322. It consists of a part piece 323 and a third lens surface molding part piece 324 arranged radially outside the second lens surface molding part piece 323.

  The center lens surface molding part 321 has a substantially cylindrical shape. An annular central step 325 is disposed below the central lens surface molding piece 321.

  The first lens surface molding part 322 has a shape obtained by dividing a cylinder having a thickness into four equal parts by a plane including the central axis. A first seat 322b is formed at the lower part of the side surface of the first lens surface molding part 322 on the central axis CA1 side. The side surface on the central axis CA1 side of the first lens surface molding piece 322 has a shape complementary to a part of the outer surface of the central lens surface molding piece 321. A first step portion 322 a is formed at the lower portion of the radially outer side surface of the first lens surface molding portion 322.

  The second lens surface molding part 323 has a shape obtained by dividing a cylinder having a thickness into four equal parts by a plane including the central axis. A second seat portion 323b is formed at the lower portion of the side surface of the second lens surface molding portion 323 on the central axis CA1 side. The side surface on the central axis CA1 side of the second lens surface molding piece 323 has a shape complementary to the side surface on the radially outer side of the first lens surface molding piece 322. In addition, a second step portion 323a is formed at the lower portion of the radially outer side surface of the second lens surface molding portion 323.

  The third lens surface molding piece 324 has a shape obtained by dividing a cylinder having a thickness into four equal parts by a plane including the central axis. A third seat portion 324b is formed at the lower portion of the side surface of the third lens surface molding portion 324 on the central axis CA1 side. The side surface on the central axis CA1 side of the third lens surface molding piece 324 has a shape complementary to the side surface on the radially outer side of the second lens surface molding piece 323. A third step portion 324a is formed at the lower portion of the radially outer side surface of the third lens surface molding portion 324.

  The radial width and the dividing position in the first lens surface molding part 322, the second lens surface molding part 323, and the third lens surface molding part 324 are not particularly limited. For example, as shown in FIG. 9, each lens surface molding piece 326 may be divided in the radial direction by a curved surface passing through the third inclined surface 125d. Moreover, as shown in FIG. 10, each lens surface molding piece 326 may be divided in the radial direction by a curved surface passing through the valley line 125e of the divided recess 125a.

(Configuration of luminous flux control member)
The light flux controlling member according to the second embodiment molded using the mold piece 300 of the molding die according to the second embodiment is implemented in that it has an annular second convex portion centered on the central axis CA1. This is different from the light flux controlling member 100 according to the first embodiment. The second convex part is a gap between the central lens surface molding part 321 and the first lens surface molding part 322, a gap between the first lens surface molding part 322 and the second lens surface molding part 323, or the second convex part. The gap between the second lens surface molding portion 323 and the third lens surface molding portion 324 is transferred to form the Fresnel lens portion 222.

(effect)
As described above, the mold piece 300 according to the second embodiment is more divided than the mold piece 100 according to the first embodiment because the lens surface molding portion 326 is further divided by the curved surface along the arc. Degassing can be performed efficiently. Further, the light flux controlling member manufactured by injection molding using this mold piece 300 can obtain light distribution characteristics with higher accuracy than the light flux controlling member 200 according to the first embodiment.

  In each of the above-described embodiments, the example in which two lens surface molding pieces adjacent to each other are in close contact with each other from the upper part to the entire lower part of the mold piece is described. There may be a large gap between the lens surface molding pieces.

  In each of the above embodiments, the example in which the lens surface molding unit main body 120 is divided by a plane (divided plane S1) has been described. However, the lens surface molding unit main body 120 may be divided by a curved surface.

  The mold according to the present invention is useful, for example, in the manufacture of a light flux controlling member applied to a camera flash or the like.

DESCRIPTION OF SYMBOLS 10 Mold member 20 Transfer part 21 Dividing surface 22 Step 23,125 Concave 30 Edge 40 Concave groove 100,300 Mold piece 120,320 Lens surface molding part main body 121 Transfer surface 121a Divided transfer surface 122 Lens surface molding part main body stage Part 122a Divided step part 123 Refraction part molding area 123a Inner transfer area 124 Fresnel lens part molding area 124a Outer transfer area 125a Divided concave part 125b First inclined surface 125c Second inclined surface 125d Third inclined surface 125e Valley lines 126, 326 Lens surface Molded part 126a Split mold 140 Holder 142 Holder seat part 200 Light flux controlling member 220 Incident area 221 Refraction part 222 Fresnel lens part 223 Convex 224 Convex part 224a Fourth inclined surface 224b Fifth inclined surface 224c Sixth inclined surface 224d Ridge line 240 Output area 21 Central lens surface molding part 322 First lens surface molding part 322a First step part 322b First seat part 323 Second lens surface molding part piece 323a Second step part 323b Second seat part 324 Third lens surface molding Part 324a Third step portion 324b Third seat portion 325 Central step portion CA1 Center axis of mold piece CA2 Center axis of light flux controlling member

Claims (5)

A molding die having a transfer surface for molding a light flux controlling member that controls light distribution of light emitted from a light source,
A mold body including a plurality of mold pieces divided by a plane passing through a center point of the transfer surface;
A holder for fixing the plurality of mold dies,
Each of the plurality of molding die pieces has a divided transfer surface in which a plurality of concave portions including arc-shaped valley lines centered on the center point are formed.
Mold.   The mold according to claim 1, wherein the mold piece is further divided by a curved surface along an arc centered on the center point.   The mold according to claim 2, wherein the mold piece is divided by a curved surface passing through the valley line. A light flux controlling member for controlling the light distribution of light emitted from the light source,
A plurality of annular projections formed using the mold according to any one of claims 1 to 3 have an incident region in which concentric circles are arranged,
Luminous flux control member.   5. The light flux controlling member according to claim 4, wherein a protrusion that connects the center of the incident region and the outermost convex portion is formed in the incident region.

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