JP6503761B2 - Method of manufacturing optical element and mold - Google Patents

Description

The present invention relates to a manufacturing method and the mold of the optical element formed by injection molding or the like, a method for manufacturing such a particular horizontal type optical element.

  As the optical element, optical lenses of various shapes according to applications and the like have been proposed. Among them, there is a so-called square lens in which, for example, the periphery of the lens portion has a square shape or a square shape (see Patent Documents 1 to 6). Such a square lens is characterized in that it can be placed on the support surface in a square part without using other instruments or the like. When the square lens is placed on the support surface, the optical axis of the lens unit can be made parallel to the support surface.

  This type of square lens is generally produced by transferring the shape to the glass or resin material supplied between a pair of mold members, but when the pair of mold members are butted to form a side surface shape Due to the mold configuration, there may be burrs corresponding to the PL surface or parting surface. Such a burr extends from the side surface outward in the direction perpendicular to the optical axis, and therefore, when the square lens of the molded product is placed on and fixed to the support surface, the optical axis tilts. In the case where a preform is sandwiched and pressed between a pair of mold members, although the occurrence of burrs as described above can be suppressed by the sleeves surrounding the pair of mold members, complicated preparations such as preparation of the preform are necessary. If the preform is smaller, the handling to be installed in the mold becomes difficult, and the efficiency of molding decreases. Furthermore, since the above-described square lens has a fixed distance depending on the mold, the distance from the optical axis to the side surface is fixed, so when it is desired to adjust the height of the optical axis from the support surface, correction of the mold It is necessary to insert the spacer, which will increase the cost.

Unexamined-Japanese-Patent No. 2007-286211 JP, 2011-252933, A JP 2008-297146 A JP 2008-297149 A JP 2007-86149 A JP 2008-189498 A

The present invention has been made in view of the above background art, and prevents an optical element such as a square lens from being installed in an inclined manner, and suppresses the decrease in molding efficiency and the increase in cost. and to provide a manufacturing method and the mold of the device.

  In order to achieve the above object, the manufacturing method according to the present invention includes a lens unit having an optical function and a flange unit extending around the lens unit, and is provided on the outer periphery or outside of the flange unit and parallel to the central axis The flat portion is formed by transferring the flange adjustment member insertable into the first mold member, and the first portion is formed by adjusting the thickness of the flange adjustment member. It is characterized in that the gap with the second mold member clamped opposite to the member is reduced.

  In the above manufacturing method, the thickness adjustment of the flange adjustment member for forming the flat portion reduces the gap between the first mold member and the second mold member which is clamped against the first mold member. Even in the case of molding to the side surface shape, it is possible to prevent the laterally disposed optical element from being inclined and installed by the burr extending laterally from the flat portion of the side surface.

  According to a specific aspect of the present invention, in the above manufacturing method, the flange portion has a rectangular outer shape. In this case, the mounting flat portion corresponds to any one of the four side surfaces of the flange portion. Here, the rectangular shape is not limited to a quadrangular prism, but includes a polygonal prism-like contour obtained by chamfering the ridge of a quadrangular prism.

  According to another aspect of the present invention, an optical element is formed by injection molding in which a resin is supplied between a first mold member and a second mold member. In this case, rapid and efficient molding of the resin optical element becomes possible.

  According to still another aspect of the present invention, a predetermined gap is formed between the parting surfaces of the first mold member and the second mold member and around the transfer surface for transferring the shape to the optical element. ing. In this case, it is possible to suppress the gas from being accumulated in the mold space and to improve the shape transfer accuracy.

  According to still another aspect of the present invention, the flange adjustment member is made of a material having a thermal expansion coefficient larger than that of the material of the surrounding mold portion, and the gap at the molding temperature disappears from the second mold member. In this case, no gap is formed on the side of the second mold member of the flange adjustment member at the time of molding, and the formation of burrs can be reliably prevented.

  According to still another aspect of the present invention, the flange adjustment member is a rod-like member, and adjusts the distance from the central axis to the flat portion by advancing and retracting the flange adjustment member in the longitudinal direction. In this case, it is possible to easily adjust the distance from the central axis to the flat portion in the obtained optical element by adjusting the advancing and retracting of the flange adjusting member.

  According to still another aspect of the present invention, the end face of the flange adjustment member to which the flat portion is transferred is subjected to a process for reducing the degree of flatness to enhance the flatness. In this case, the surface accuracy of the flat portion can be increased, and the accuracy of mounting the optical element on the support surface can be enhanced.

According to still another aspect of the present invention, the end surface of the flange adjustment member to which the flat portion is transferred has a side surface portion excluding the flat portion among the outer peripheral portion of the flange portion on the basis of a state perpendicular to the parting surface. The inclination is set to be less than the inclination corresponding to the extraction taper of . In this case, when the optical element is placed and fixed on the support surface, the central axis can be precisely disposed parallel to the support surface.

  According to still another aspect of the present invention, the optical element is formed of a resin material, and by adjusting the outline shape including the width in the direction along the central axis of the gate for supplying the resin to the mold space, The barycentric position of the optical element in the direction along the central axis is adjusted. In this case, it becomes easy to prevent the optical element placed on the support surface from falling down.

  In order to achieve the above object, a mold according to the present invention includes a first mold member and a second mold member, and a mold space formed between the first and second mold members allows a central axis to be formed on an outer peripheral portion. A mold for molding an optical element having flat portions extending in parallel, including a flange adjustment member insertable into the first mold member and molding the flat portion by transfer, by adjusting the thickness of the flange adjustment member The gap with the second mold member clamped opposite to the first mold member is reduced.

  In the above-mentioned mold, since the gap between the second mold member to be clamped opposite to the first mold member is reduced by adjusting the thickness of the flange adjustment member for forming the flat portion, the pair of mold members are butted Even in the case of molding to the side surface shape, it is possible to prevent the optical element to be placed horizontally after molding from being inclined and installed by the burr extending laterally from the flat portion.

(A) is a side view of an optical element according to an embodiment of the present invention, and (B) is a plan view of the optical element shown in (A). It is a figure explaining the shaping | molding apparatus containing the shaping | molding die for enforcing the manufacturing method of an optical element. (A) And (B) is an end elevation and a side sectional view of the first die portion of the mold shown in FIG. It is a partial expanded sectional view of a shaping | molding die. (A) And (B) is a figure explaining the fine adjustment of the position of a flange adjustment member. (A) and (B) is a figure explaining the heating back and front of a flange adjustment member. It is a figure explaining the method to assemble | attach the optical element shown to FIG. 1 (A) etc. to a board | substrate. It is a figure explaining the modification of the optical element shown to FIG. 1 (A) etc. FIG.

  Hereinafter, specific embodiments of the optical element according to the present invention will be described in detail with reference to the drawings.

  As shown to FIG. 1 (A) and 1 (B), the optical element 30 of this embodiment is provided with the main element main body 10 and the gate part 20 attached to this. The optical element 30 is a component incorporated in a light source device for optical communication and other optical devices, and specifically, is a coupling lens that condenses light diverging from the light source on a fiber end or the like. The optical element 30 is a molded article made of a resin having optical transparency, and is formed by injection molding using a mold as described later. That is, the element body 10 and the gate unit 20 are integrated.

  The element body 10 of the optical element 30 is a horizontally-placed square lens. That is, the element body 10 is relatively thick and has a prismatic or block-like contour. The element body 10 has a circular lens portion 11 and an annular flange portion 12. The lens unit 11 is, for example, a biconvex optical lens, and has a first optical surface 11 a and a second optical surface 11 b. The flange portion 12 extends outward from the lens portion 11 laterally outward in a direction perpendicular to the optical axis direction and has a square-shaped contour, and is an inner side circular and an outer side rectangular shape. ing. The flange portion 12 includes two flange surfaces 12a and 12b extending in parallel around the optical surfaces 11a and 11b of the lens portion 11, and four flat, substantially rectangular flange side surfaces 12c extending between the flange surfaces 12a and 12b. To 12f. The flange side surfaces 12c to 12f may be, for example, mirror surfaces, but may be roughened microscopically as long as macroscopic flatness is not impaired. Of the four flange side surfaces 12c to 12f, the flange side surface 12e on the side opposite to the gate is a portion for fixing the optical element 30 to other members by adhesion or the like, that is, a flat surface for assembly or mounting It has become. Therefore, the flange side surface 12e is relatively precisely formed, and the flatness and the surface roughness are smaller than those of the other flange side surfaces 12c, 12d and 12f. Although R or a curved surface is not provided at the boundary between the flange side surface 12e and the flange side surfaces 12d and 12f adjacent to the flange side surface 12e, correction of the molding die Can also provide R at these boundaries.

  The gate portion 20 has a block-like contour and is at the center of one side of the contour of the element body 10 viewed from the direction of the central axis CX corresponding to the optical axis, and corresponds to one flange side 12c of the element body 10. The side wall portion projects from a region near the flange surface 12b. The end 20a of the gate 20 is separated from the gate or runner that was present immediately after molding. The whole of the gate unit 20 functions as a handling unit, and is gripped by tweezers and other holders at the time of handling for transporting, mounting, etc. the optical element 30.

  FIG. 2 is a view for explaining a molding apparatus including a mold for molding the optical element 30 shown in FIGS. 1 (A) and 1 (B). Moreover, FIG. 3 (A) and 3 (B) are the top view and side sectional view of a 1st type | mold part, and FIG. 4 is a partial expanded sectional view of a shaping | molding die. The molding apparatus 100 shown in FIG. 2 is an injection molding machine, and includes a molding die 50 for molding the resin-made optical element 30 whose shape has been transferred, a drive device 60 for opening and closing the molding die 50, and the molding die 50. An adjusting mechanism 70 for advancing and retracting a flange adjusting member 53 incorporated therein to a minute amount along the parting surface PL, and a control device 80 for controlling the operation of the drive device 60 and the like.

  The mold 50 has a first mold member 51 for transferring the shape on the side of the first optical surface 11 a and the side surface of the optical element 30, and a first die for transferring the shape on the side of the second optical surface 11 b of the optical element 30. And a second mold member 52 disposed to face the member 51, and a flange adjustment member 53 along with the first mold member 51. In the illustrated example, for convenience of explanation, although the mold 50 is placed vertically, it is actually placed horizontally. However, the forming die 50 may be vertical as well as horizontal.

  The drive device 60 drives the movable first mold member 51 under the control of the drive device 60 to advance and retract in the ± Z direction. Specifically, at the time of mold closing, the first mold member 51 is advanced in the + Z direction, and at the time of mold clamping, the first mold member 51 is pressed against the second mold member 52 with a predetermined clamping force. As a result, parting surface PL1 that is the opposing surface to the other of first mold member 51 and parting surface PL2 that is the opposing surface to the other of second molding member 52 are close to each other, but around forming space CV, The gap GA is formed on the micron order of 10 μm or less (see FIG. 3B and the like). The gap GA is provided to release the air accumulated in the molding space CV to the outside to improve transferability, and the width of the gap GA at the time of mold clamping is precisely determined by a support (not shown) provided on the mold 50. Maintained. At the time of mold opening after molding, the first mold member 51 is retracted in the −Z direction to separate the first mold member 51 from the second mold member 52. Thus, the molded product MP left on the first mold member 51 can be removed and carried out of the molding die 50.

  The adjusting mechanism 70 is fixed to the side surface of the mold 50 and moves the flange adjusting member 53 inserted in the first mold member 51 by a small amount in the ± Y direction perpendicular to the Z axis. Thereby, although the details will be described later, the distance from the central axis CX to the end face 53a of the flange adjustment member 53 is adjusted in the range of several μm to several hundreds μm, and as a result The distance to the flat surface 12e can be easily adjusted.

  The control device 80 controls the operation of the drive device 60 and the like. Thereby, mold closing, mold clamping, mold opening and the like become possible. The mold (50) incorporates a heater (not shown) that operates under the control of the control device 80, and during resin injection, the mold (50) is preheated appropriately, and after clamping, both parting surfaces PL1,1 The PL2 periphery can be maintained at a temperature suitable for molding.

  Hereinafter, with reference to FIG. 4 etc., the principal part of the shaping | molding die 50 is demonstrated. In the forming die 50, the first mold member 51 has a shape transfer portion 55a, a gate portion 55b, and a runner portion 55c on the side of the first parting surface PL1. The shape transfer portion 55a has a shape in which the first optical surface 11a, the flange surface 12a, the flange side surfaces 12c, 12d, 12f, and the like in the element body 10 of the optical element 30 are reversed. The tip end surface 56a of the core 56 is exposed at the center of the shape transfer portion 55a, and the core 56 is supported by the shaft member 57a at the root side and is embedded in the peripheral mold 57 together with the shaft member 57a. The tip end surface 56a of the core 56 is a concave surface obtained by inverting the first optical surface 11a.

  Among the inner side surfaces of the shape transfer portion 55a, the pair of inner side surfaces 7d and 7f shown in FIG. 3A and the like are flat surfaces corresponding to the flange side surfaces 12d and 12f. The distance is increased on the 1 parting surface PL1 side. That is, the inner side surfaces 7d and 7f form an obtuse angle slightly larger than a right angle with respect to the first parting surface PL1. The inner side surface 7 e of the inner side surface of the shape transfer portion 55 a is formed by the end surface 53 a of the flange adjustment member 53. The inner side surface 7e is perpendicular to the first parting surface PL1. Thus, by using the end face 53a of the flange adjustment member 53, not only the end face 53a or the inner side face 7e can not only be finely moved in the ± Y direction, but the inner side face 7e is a portion where precise processing can be easily performed. Thus, it is possible to reduce the flatness as compared with the inner side surfaces 7d and 7f. Thereby, the surface accuracy of the flange side surface (flat surface) 12e can be raised, and the mounting accuracy at the time of fixing the optical element 30 to the support surface of another member can be raised. Furthermore, even if the inner side surface 7e is perpendicular to the first parting surface PL1, the mold is released by retracting the flange adjusting member 53 by the adjusting mechanism 70 or by shrinkage in the longitudinal direction when the flange adjusting member 53 is cooled. The ease of

  The inner side surface 7c of the shape transfer portion 55a is connected to the gate portion 55b, and the gate portion 55b is connected to the runner portion 55c. The inner side surface 7c has an obtuse angle slightly larger than a right angle with respect to the first parting surface PL1.

  The flange adjustment member 53 is fitted in a groove 9 of a rectangular cross section which is on the side of the first parting surface PL1 of the first mold member 51 and extends from the shape transfer portion 55a. A slight gap is formed at room temperature between the side surface 53 d of the flange adjusting member 53 and the inner surface 9 d of the groove 9, and the sliding of the flange adjusting member 53 in the groove 9 in the ± Y direction is permitted. .

  The flange adjustment member 53 can be advanced and retracted by a minute amount in the ± Y direction perpendicular to the Z axis by the adjustment mechanism 70. For example, in the state of FIG. 5A, the flange adjustment member 53 retracts to be separated from the gate portion 55b, and in the state of FIG. 5B, the gate portion 55b is from the original position shown by the flange adjustment member 53. Advance slightly closer to That is, the distance from the central axis CX to the end face 53a of the flange adjustment member 53 can be adjusted. This means that in the optical element 30, the distance d from the central axis (optical axis) CX to the flange side surface 12e which is a flat surface for mounting can be finely adjusted (see FIG. 1). That is, there is no need to replace the first mold member 51 or to arrange a spacer between the optical element 30 and the support surface of the other member or the assembly receiving portion, and the dimension adjustment of the optical element 30 is simple and low. It will be possible at cost.

  The flange adjustment member 53 is made of a material having a thermal expansion coefficient larger than that of the peripheral mold 57 which is the peripheral mold portion. Therefore, in the room temperature state shown in FIG. 6A, a gap is present between the flange adjustment member 53 and the groove 9, and a gap GA is also present between the second mold member 52. On the other hand, at the molding temperature shown in FIG. 6B (specifically, the temperature at the time of injecting the resin), the gap between the flange adjustment member 53 and the groove 9 almost disappears. There is no gap GA between them. That is, at the time of molding, the upper surface 53f of the flange adjustment member 53 and the second parting surface PL2 of the second mold member 52 are substantially in close contact with each other and there is no gap. The formation of burrs extending in the direction perpendicular to the central axis CX can be reliably prevented. However, a small burr 91 corresponding to the gap between the peripheral mold 57 and the flange adjustment member 53 is provided on the ridge portion AC (see FIG. 1A) between the flange surface 12a and the flange side surface (flat surface) 12e. Although formed, since it extends parallel to the central axis CX, it does not affect the mounting accuracy when fixing the optical element 30 to the support surface of the other member. In addition, a small burr 92 may be formed between the first optical surface 11 a and the flange surface 12 a corresponding to the gap between the core 56 and the peripheral mold 57, but the optical element 30 may be formed of another member It does not affect the mounting accuracy when fixing to the support surface of the housing.

  Of the molding die 50, the second mold member 52 has a shape transfer portion 58a and a peripheral surface 58d on the side of the second parting surface PL2 (see FIG. 6). The shape transfer portion 58 a has a shape obtained by inverting the second optical surface 11 b and the flange surface 12 b in the element body 10 of the optical element 30. The peripheral surface 58d is a part of the second parting surface PL2.

  As shown in FIG. 4, a molding space CV, a gate GT and a runner RU are formed between the mold members 51 and 52 in a mold-closed state. At the time of molding, the molten resin is supplied from the runner RU side, and is injected into the molding space CV through the gate GT. The molding space CV is sandwiched between a pair of optical surfaces 11a and 11b corresponding to the pair of optical surfaces 11a and 11b, and is a portion where the lens portion 11 and the like of the element main body 10 are formed. The gate GT is a portion where the gate portion GP extending from the element body 10 or the gate portion 20 is formed. The runner RU is a portion where a runner portion RP connected to the gate portion GP is formed. The molded article MP taken out after the mold opening for separating the mold members 51 and 52 comprises the above-mentioned element body 10, the gate portion GP, the runner portion RP and the like. The molded article MP is separated near the boundary between the gate portion GP and the runner portion RP, and is an optical device comprising an element body 10 having an optical function and a gate portion 20 which is a main portion on the element body 10 side of the gate portion GP. The element 30 is obtained.

  The assembly of the optical element 30 will be described with reference to FIG. The UV curable resin UA is previously applied to a target area set on the support surface 2 a of the substrate 2. Thereafter, by holding the gate unit 20, the optical element 30 is transported to the upper side of the substrate 2, and the optical element 30 is mounted on a target area on the support surface 2a. That is, the flange side surface 12e and the support surface 2a are brought close to or in close contact with each other through the UV curing resin UA. Next, the laser diode (not shown) is aligned by finely moving the optical element 30 two-dimensionally on the substrate 2 while holding the gate portion 20 loose. At this time, the optical element 30 can be rotated about the vertical axis as well as translated in the horizontal direction. Also, at the time of alignment, the laser diode can be made to emit light to check the state of the light beam passing through the optical element 30. When the alignment is completed, the UV curable resin UA is cured by irradiating the UV curable resin UA through the optical element 30 with UV light. As a result, the flange side surface 12 e of the optical element 30 and the support surface 2 a on the substrate 2 are closely fixed in close contact with each other. In the above, since the surface roughness and the flatness of the flange side surface 12e are small, the contact between the flange side surface 12e and the support surface 2a can be stabilized, and the minute unevenness of the support surface 2a and the flange side surface 12e is crushed and the optical element It is possible to prevent the inclination of 30 from becoming unstable.

  According to the manufacturing method of the embodiment described above, the thickness adjustment or width adjustment in the central axis CX direction of the flange adjustment member 53 for forming the flange side surface (flat surface) 12 e is opposed to the first mold member 51 Since the gap with the second mold member 52 to be clamped is reduced, even in the case where the pair of mold members 51 and 52 are butted to form the side surface shape of the optical element 30, the horizontally placed optical element 30 is a flange The burrs extending laterally from the side surface 12e can prevent installation at an angle.

  As mentioned above, although the optical element 30 of embodiment was demonstrated, the optical element which concerns on this invention is not limited to said thing, A various deformation | transformation is possible. For example, the optical element 30 can be made of glass as well as resin. When the optical element 30 is made of glass, it is formed by press forming of a glass preform or a glass droplet, so the gate portion 20 does not exist and only the element body 10 is formed.

  Further, the optical element 30 is not limited to the combination lens, but may be a collimator lens, a pickup lens, or the like. That is, the shapes of the optical surfaces 11 a and 11 b provided in the lens unit 11 can be appropriately set in accordance with the application, specification, and the like of the optical element 30.

  In the optical element 30, in the ridge portion AC adjacent to the flange side surface 12e, the burrs 91 and the buildup of the meat are formed due to the position adjustment (in particular, retraction) of the flange adjustment member 53, but these formations are suppressed For this purpose, the spacer may be embedded in the space formed between the lower portion of the tip end surface 56 a of the flange adjustment member 53 and the peripheral mold 57.

  As shown in FIG. 8, the thickness of the gate portion 20 of the optical element 30 in the central axis CX direction or the optical axis direction can be increased or decreased, for example, as indicated by a dotted line. Thereby, the center of gravity of the optical element 30 can be balanced with respect to the central axis CX direction with the flange side surface 12e as a reference, and the posture of the optical element 30 when mounting the optical element 30 on the support surface 2a of the substrate 2 It can be stabilized.

12c-12f: flange side surface 2a: support surface 7c, 7d, 7e, 7f: inner surface, 9: groove, 9d: inner surface, 10: element main body, 11: lens portion, 11a, 11b: optical surface, 12: Flange part 12a, 12b: Flange surface 20: Gate part 30: Optical element 50: Mold, 51, 52: First and second type members 53: Flange adjustment member 53a: End face 55a: Shape Transfer part, 55b: Gate part, 55c: Runner part, 56: Core, 57: Surrounding type, 60: Drive device, 70: Adjustment mechanism, 80: Control device, 91, 92: Burr, 100: Molding device, CV ... Molding space, CX: central axis, GA: gap, MP: molded article, PL1, PL2: parting surface

Claims (10)

A method of manufacturing an optical element comprising: a lens portion having an optical function; and a flange portion extending around the lens portion, the flat portion being provided on an outer peripheral portion of the flange portion and extending parallel to a central axis And
The flat portion is formed by transfer of a flange adjustment member insertable into the first mold member,
A method of manufacturing an optical element, comprising reducing a gap between a second mold member opposed to the first mold member and the second mold member clamped by adjusting the thickness of the flange adjustment member.   The method for manufacturing an optical element according to claim 1, wherein the flange portion has a rectangular outer shape.   The optical element is formed by injection molding which supplies resin between the said 1st type | mold member and the said 2nd type | mold member, The manufacturing method of the optical element as described in any one of Claim 1 and 2 characterized by the above-mentioned. .   A predetermined gap is formed between the parting surfaces of the first mold member and the second mold member and around the transfer surface for transferring the shape to the optical element. The manufacturing method of the optical element as described in any one of 1-3.   The flange adjusting member is made of a material having a thermal expansion coefficient larger than that of the material of the surrounding mold part, and a gap with the second mold member disappears at the temperature at the time of molding. The manufacturing method of the optical element as described in any one.   The flange adjusting member is a rod-like member, and the distance from the central axis to the flat portion is adjusted by advancing and retracting the flange adjusting member in the longitudinal direction. The manufacturing method of the optical element as described in one term.   The method of manufacturing an optical element according to any one of claims 1 to 6, wherein an end face of the flange adjustment member to which the flat portion is transferred is subjected to a process of reducing the degree of flatness. The end face of the flange adjustment member to which the flat portion is transferred has an inclination corresponding to the draft of the side portion excluding the flat portion in the outer peripheral portion of the flange on the basis of a state perpendicular to the parting surface. The method for manufacturing an optical element according to any one of claims 1 to 7, wherein the inclination is set to a smaller value.   The optical element is formed of a resin material, and the position of the center of gravity in the direction along the central axis of the optical element by adjusting the contour shape including the width in the direction along the central axis of the gate for supplying the resin to the mold space The method of manufacturing an optical element according to any one of claims 1 to 8, wherein For molding an optical element having a first mold member and a second mold member, and having a flat portion extending in parallel to a central axis in an outer peripheral portion by a mold space formed between the first and second mold members. Mold and
And a flange adjustment member insertable into the first mold member and forming the flat portion by transfer.
A molding die characterized by reducing a gap with a second die member opposed to the first die member by adjusting the thickness of the flange adjusting member.

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