JP2008194858A - LENS, INJECTION MOLD FOR PRODUCTION OF LENS, AND LENS MANUFACTURING METHOD - Google Patents

Abstract

An injection mold capable of releasing a lens produced by injection-molding a liquid resin material without using an ejector pin and without making a protruding mark on the optical surface of the lens, and A lens manufacturing method and a lens are provided.
In an injection mold 30 according to the present invention, protrusions forming recesses 10a and 10b having inclined surfaces 21a and 22a inclined in a direction different from the mold opening direction are formed in a cavity 3. The plastic lens 19 that is injection-molded in the cavity 3 is formed with a projection 14 that is injection-molded by the projection-forming recesses 10a and 10b outside the optically effective surface. When the mold is opened, the projection 14 is released along the inclined surfaces 21a and 22a in a direction different from the mold opening direction, so that the plastic lens 19 is rotated so that the optically effective surfaces 11 and 12 are inclined. Then, the mold is released from the injection mold 30.
[Selection] Figure 4

Description

  The present invention relates to a lens, an injection mold used for manufacturing the lens, and a method for manufacturing the lens, and more specifically, release is possible without using an ejector pin for release in a release process during injection molding. The present invention relates to a lens, an injection mold used for manufacturing the lens, and a lens manufacturing method.

  Conventionally, in order to manufacture a plastic lens by injection molding, first, after pouring molten resin into a mold cavity and solidifying by cooling, the mold is opened to take out a molded product (plastic lens) from the mold, and the mold A molded product is ejected with an ejector pin in a direction parallel to the opening axis. However, when ejecting with an ejector pin, it is necessary to take a method of projecting and releasing the molded product so that no local projecting trace remains on the optical surface within the optical effective diameter of the molded product due to optical performance. is there.

  FIG. 9 shows a configuration in which a molded product is released by such a technique. In the configuration shown in FIG. 9, the ejector pin 100 is disposed on the flange 101 formed outside the optically effective diameter of the molded product 120. Here, 102 in FIG. 9 is a fixed nest, and 103 is a movable nest.

  FIG. 10 also shows a configuration in which the molded product is released by the same method as in FIG. 9. The molded product is formed on the entire molded surface of the movable insert 104 by using the movable insert 104 forming the optical surface also as an ejector pin. In this configuration, 120 is protruded. Here, reference numeral 102 in FIG. 10 is a fixed insert, and 105 is a movable side template.

  By the way, the flange portion 101 formed in FIGS. 9 and 10 is used for positioning the lens in the radial direction or the axial direction when the lens is assembled in the lens barrel, or holding the lens in the lens barrel, and an ejector. Since it is used to contact the pin, it is preferable to widen the width. However, when the width of the brim portion 101 is increased, the outer shape of the lens is increased correspondingly, resulting in inconvenience.

  As a configuration for releasing a lens having a small brim width, there is an injection mold disclosed in Patent Document 1. The structure of this injection mold will be described with reference to FIGS. 11 (a) and 11 (b). FIG. 11 (a) is a cross-sectional view of an injection mold in which a molding surface of a substantially hemispherical plastic lens is formed on one side of the mold opening surface, and FIG. 11 (b) is a diagram of the injection mold. It is a figure for demonstrating an effect | action. As shown in FIG. 11 (a), first, a plastic lens 217 is injection-molded on the cavity 203 as usual using an injection mold. Next, the fixed mold 216 is separated from the movable mold 250, that is, the mold is opened, and the mold opening surface 208a of the movable-side mold plate 208 is exposed, so that the plastic lens 217 molded in the cavity 203 and the plastic lens 217 are obtained. The gate 218, the runner 219, and the sprue 220 connected to each other appear. The molded plastic lens 217 forms a substantially hemispherical optical surface 207 and is in close contact with the cavity 203. Next, in order to release the plastic lens 217 from the cavity 203 of the movable nest 202, the upper ejecting plate 211 and the lower ejecting plate 212 are pressed by an ejecting rod of an injection molding machine (not shown), and the ejector pin 214 is moved. The sprue 220 is projected together with the cold slug portion 231 at the tip of the lever. In this case, since the ejector pin 214 is not disposed on the plastic lens 217, the gate 218, and the runner 219, the flange 111 on the side opposite to the gate 218 of the plastic lens 217, that is, on the cavity forming surface of the movable insert 2. When the plastic lens 217 rotates with one point of the edge with the mold opening surface 202a as a fulcrum 217a, these are integrally released from the movable insert 202 and the movable side mold plate 208. The plastic lens 217 in the released state is taken out by picking up the sprue 220 with a take-out robot or the like (not shown), and then the gate 218 integrated with the plastic lens 217 is cut to remove the runner 219 and the sprue 220. Remove. With this method, it is possible to reduce the outer diameter of the lens without leaving a protruding mark by the ejector pin on the molded body 121.

Patent Document 2 discloses a configuration in which a tag portion that is a surplus portion is provided around the optical surface in place of the brim portion as described above. FIG. 12 is a plan view showing a configuration of a plastic lens molded by a mold disclosed in Patent Document 2. FIG. 12A shows the configuration of the plastic lens at the time of injection by the mold, and FIG. 12B shows the molded product (a) obtained by processing the plastic lens shown in FIG. The product is a plastic lens configuration. In FIG. 12A, the plastic lens is provided with a runner portion 310 and a tag portion 311 formed around the optical surface 312. The runner part 310 and the tag part 311 are pressed with an ejector pin to release the mold, and after release, the runner part 10 and the tag part 11 are cut to obtain a molded product. Thus, by providing the tag part 311, it is not necessary to press the whole collar part, and a lens can be reduced in diameter.
Japanese Patent Laid-Open No. 10-329176 (published December 15, 1998) Japanese Patent Laid-Open No. 2002-200247 (published July 16, 2002)

  However, in the case of the configurations of Patent Documents 1 and 2, unlike conventional plastic lens molding in which a thermoplastic resin is heated and melted and injection molding is performed, a liquid material in an uncured state, such as a thermosetting resin, is injection molded. In this case, resin leakage may occur from the clearance portion of the ejector pin. Further, even when this clearance is reduced and resin leakage is suppressed, there is a concern that the slidability of the ejector pin is deteriorated due to accumulation of a small amount of resin leakage.

  In addition, in the case of the configuration of Patent Document 2, it is necessary to cut the tag portion in addition to the cutting step of the runner portion 310 after releasing, and there is a concern that the number of steps increases and throughput decreases.

  Therefore, the present invention has been made in view of the above problems, and its purpose is to perform injection molding of a liquid resin material without using an ejector pin, and without making a protruding trace on the optical surface of the lens. Thus, an injection mold capable of releasing a lens to be manufactured, a method for manufacturing the lens, and a lens are provided.

  In order to solve the above-described problems, a first injection mold according to the present invention includes a fixed member and a movable member having a molding surface for molding an optically effective surface of a lens. The member is configured to move in a predetermined direction so that the member can be in contact with or released from the fixed member, and the fixed member and the movable member are opposed to each other on the molding surface. A gate part communicating with the cavity, which is obtained by bringing the fixed member and the movable member into contact with a cavity having the molding surface on the wall surface, which is obtained by contacting, and the gate part. An injection mold capable of forming a lens by injecting a polymerizable material through a runner, wherein the fixed member or the movable member is provided with a sprue communicating with the runner. The fixed member or the movable member has an inclined surface that is inclined at a predetermined angle with respect to the moving direction of the movable member at a position different from the molding surface on the wall surface of the cavity. It is characterized in that a concave portion is formed. Specifically, the predetermined angle is greater than 0 ° and less than 90 °.

  According to said structure, even if it is a case where a liquid resin material is injection-molded and manufacturing a lens, since there is no need to use an ejector pin, there is no possibility of causing the above resin leaks. In addition, since the lens can be released without contacting the ejector pin with the flange portion so that the optically effective surface does not have a protruding mark, the protrusion of the flange portion is considered in consideration of contacting the ejector pin. There is no need to increase the width, and the width of the brim portion can be reduced. Therefore, it is possible to reduce the size of the lens.

  Specifically, according to the configuration of the present invention, as usual, the cavity formed by the fixed member and the movable member is filled with a polymerizable material and injected, and then the movable member is moved to move the movable member. Although the contact with the member is released, if the mold of the present invention is used, the movable member is moved and simultaneously formed by a recess having an inclined surface inclined at a predetermined angle with respect to the moving direction. The formed part is released in a direction different from the moving direction along the inclined surface.

  As a result, the main part of the lens having the optically effective surface formed by the part having the molding surface, which is the main part of the cavity, is the part formed by the concave portion provided outside the main part (hereinafter referred to as the protrusion of the lens). And the portion superposed on the sprue as a fulcrum, the optically effective surface of the lens formed by the molding surface is released from the molding surface of the fixed member and the movable member. The entire lens including the protruding portion of the lens can be released without using an ejector pin as in the prior art. Here, “rotate” indicates that the main lens portion moves such that the optically effective surface of the lens formed by the molding surface is inclined with respect to the molding surface.

  Of course, since it is not necessary to use an ejector pin, the resin being injected does not adhere to the ejector pin, and there is no need to worry about the slidability of the pin.

  Conventionally, the flange portion of the lens is configured to be formed to a certain extent so as not to hinder the contact operation of the ejector pin. However, according to the configuration of the present invention, it is not necessary to use the ejector pin. Therefore, it is possible to manufacture a miniaturized lens.

  Further, since it is not necessary to use an ejector pin, the mold can be reduced in size as compared with a conventional injection mold.

  In addition, even when bubbles are generated for some reason, particularly in the molding surface portion in the cavity during the injection molding process, according to the configuration of the present invention, a recess is formed outside the main portion of the cavity. Therefore, the bubbles as described above can be retracted in the recess. Therefore, according to the configuration of the present invention, it is possible to provide a lens having high reliability with respect to optical performance.

  In order to solve the above-described problems, a second injection mold according to the present invention includes a fixed member and a movable member having a molding surface for molding an optically effective surface of a lens, and the movable The member is configured to move in a predetermined direction so that the member can be in contact with or released from the fixed member, and the fixed member and the movable member are opposed to each other on the molding surface. An injection molding die capable of molding a lens by injecting a polymerizable material into a cavity having the molding surface on a wall surface, obtained by contacting, wherein the fixed member and the movable member include A recess having an inclined surface inclined at a predetermined angle with respect to the moving direction of the movable member is formed at a position different from the molding surface on the wall surface of the cavity. It is a feature. Specifically, the predetermined angle is greater than 0 ° and less than 90 °.

  According to said structure, even if it is a case where a liquid resin material is injection-molded and manufacturing a lens, since there is no need to use an ejector pin, there is no possibility of causing the above resin leaks. In addition, since the lens can be released without contacting the ejector pin with the flange portion so that the optically effective surface does not have a protruding mark, the protrusion of the flange portion is considered in consideration of contacting the ejector pin. There is no need to increase the width, and the width of the brim portion can be reduced. Therefore, it is possible to reduce the size of the lens.

  Specifically, according to the configuration of the present invention, as usual, the cavity formed by the fixed member and the movable member is filled with a polymerizable material and injected, and then the movable member is moved to move the movable member. Although the contact with the member is released, if the mold of the present invention is used, the movable member is moved and simultaneously formed by a recess having an inclined surface inclined at a predetermined angle with respect to the moving direction. The formed part is released in a direction different from the moving direction along the inclined surface.

  As a result, the main part of the lens having the optically effective surface formed by the part having the molding surface, which is the main part of the cavity, is the part formed by the concave portion provided outside the main part (hereinafter referred to as the lens protrusion). Since the optically effective surface of the lens formed by the molding surface is released from the molding surface of the fixed member and the movable member, the ejector pin is used as in the conventional case. In addition, the entire lens including the protruding portion of the lens can be released. Here, “rotate” indicates that the main lens portion moves such that the optically effective surface of the lens formed by the molding surface is inclined with respect to the molding surface.

  Of course, since it is not necessary to use an ejector pin, the resin being injected does not adhere to the ejector pin, and there is no need to worry about the slidability of the pin.

  Conventionally, the flange portion of the lens is configured to be formed to a certain extent so as not to hinder the contact operation of the ejector pin. However, according to the configuration of the present invention, it is not necessary to use the ejector pin. Therefore, it is possible to manufacture a miniaturized lens.

  Further, since it is not necessary to use an ejector pin, the mold can be reduced in size as compared with a conventional injection mold.

  In addition, even when bubbles are generated for some reason, particularly in the molding surface portion in the cavity during the injection molding process, according to the configuration of the present invention, a recess is formed outside the main portion of the cavity. Therefore, the bubbles as described above can be retracted in the recess. Therefore, according to the configuration of the present invention, it is possible to provide a lens having high reliability with respect to optical performance.

  Further, in the second injection mold according to the present invention, each of the recesses is provided on each of the wall surfaces on the fixed member side and the movable member side of the cavity. It is preferable that the cavities are disposed at positions facing each other across the molding surface when viewed from a direction perpendicular to the molding surface.

  According to said structure, mold release of a lens can be implemented more efficiently.

  That is, as in the present invention, the concave portion provided on the fixed member side and the concave portion provided on the movable member side are mutually connected to the molding surface when the cavity is viewed from a direction perpendicular to the molding surface. If the movable member moves when the contact between the fixed member and the movable member is released, the concave portion provided on the fixed member side and the concave portion provided on the movable member side Therefore, release of the lens optical effective surface from the molding surface can be realized with high accuracy.

  Further, the injection mold according to the present invention is provided with a flange forming portion extending in a direction perpendicular to the moving direction of the movable member at a position different from the molding surface on the wall surface of the cavity. Alternatively, the concave portion may be provided in the brim portion forming portion.

  By providing the flange portion forming portion as described above, the manufactured lens has a flange portion formed at a position different from the optically effective surface, and when positioning the lens on the lens barrel, This brim portion can be used.

  A first lens manufacturing method according to the present invention is a lens manufacturing method for manufacturing a lens that is a polymer of the polymerizable material, using the first injection mold described above. In order to solve the problem, an injection step of injecting and filling a polymerizable material into the cavity formed by contacting the fixed member and the movable member, and after the injection step, the movable member is A contact release step of releasing the contact between the fixed member and the movable member by moving the portion, wherein in the contact release step, the portion overlapped in the recess according to the movement of the movable member The lens is rotated from the fixed member and the movable member so that the optically effective surface is inclined with the portion overlapped by the sprue as a fulcrum.

  According to the above configuration, the lens can be released from the fixed member and the movable member without using an ejector pin and without making a protruding mark on the optically effective surface.

  That is, according to the manufacturing method of the present invention, in accordance with the movement of the movable member, the optically effective surface is inclined so that the portion superposed on the concave portion and the portion superposed on the sprue are fulcrums. Since the lens rotates, the lens can be released from the fixed member and the movable member without using an ejector pin.

  In addition, even when bubbles are generated for some reason, particularly in the molding surface portion in the cavity during the injection molding process, according to the configuration of the present invention, a recess is formed outside the main portion of the cavity. Therefore, the bubbles as described above can be retracted in the recess. Therefore, according to the configuration of the present invention, it is possible to provide a lens having high reliability with respect to optical performance.

  The second lens manufacturing method according to the present invention is a lens manufacturing method for manufacturing a lens which is a polymer of the polymerizable material, using the second injection mold, and the fixing An injection step of injecting and filling a polymerizable material into the cavity formed by bringing a member and the movable member into contact with each other; and after the injection step, by moving the movable member, A contact release step of releasing contact with the movable member, and in the contact release step, the optically effective surface is formed by using a portion overlapped by the concave portion as a fulcrum according to the movement of the movable member. The lens is rotated so as to be inclined, and is released from the fixed member and the movable member.

  According to the above configuration, the lens can be released from the fixed member and the movable member without using an ejector pin and without making a protruding mark on the optically effective surface.

  That is, according to the manufacturing method of the present invention, according to the movement of the movable member, the lens rotates so that the optically effective surface is inclined with the portion overlapped by the concave portion as a fulcrum. The lens can be released from the fixed member and the movable member without using them.

  In addition, even when bubbles are generated for some reason, particularly in the molding surface portion in the cavity during the injection molding process, according to the configuration of the present invention, a recess is formed outside the main portion of the cavity. Therefore, the bubbles as described above can be retracted in the recess. Therefore, according to the configuration of the present invention, it is possible to provide a lens having high reliability with respect to optical performance.

  Specifically, in the contact release step, a portion superposed on the concave portion is released in a direction different from the moving direction of the movable member along the inclined surface. By moving the overlapped portion in the concave portion in this way, the main portion (portion having an optical effective surface) of the lens integrally formed with the portion is inclined, and the lens can be rotated. it can.

  In the first and second lens manufacturing methods according to the present invention, a thermosetting resin can be used as the polymerizable material.

  Since the lens manufacturing method of the present invention uses the injection mold having the above-described configuration, even if a thermosetting resin that is liquid before thermosetting is used, a portion other than the cavity of the injection mold In addition, since the resin does not leak out and accurate injection molding can be performed, a highly reliable lens can be provided.

  In addition, in order to solve the above-described problem, the lens according to the present invention is a lens having an optically effective portion, and includes a protruding portion outside the optically effective portion, on the optical axis of the optically effective portion. When the cut surface obtained by cutting the lens in the thickness direction of the lens is viewed at a position including the center point, the projection has an angle of more than 0 ° and less than 90 ° with respect to the optical axis. It is characterized in that an inclined surface inclined at is provided. Specifically, the lens is preferably a plastic lens.

  If it is set as said structure, the projection part which has the inclined surface which inclines at an angle of more than 0 degree and less than 90 degrees will be equipped with the collar part like the conventional structure by providing outside the optical effective part. Even in the case of forming, the size of the flange portion can be made smaller than that of the conventional one, so that the lens size can be reduced.

  Further, the protrusion provided on the lens of the present invention can be used as a positioning member when the lens is disposed in another device (for example, a lens barrel).

  Specifically, in the lens according to the present invention, the protrusion is disposed at a position facing the center point when the cut surface is viewed, and is provided at the protrusion facing the lens. Each said inclined surface is comprised in parallel with each other.

  By configuring in this way, it is possible to easily rotate the lens so that the optically effective surface is inclined by using the inclined surfaces of the two opposing projecting portions.

  In addition, the lens according to the present invention may include a flange portion in addition to the optically effective portion, and the protrusion portion may be disposed on the flange portion.

  In the lens according to the present invention, it is preferable that the protrusion has a triangle whose protrusion end has an acute angle when the cut surface is viewed.

  If the first and second injection molds according to the present invention, the first and second lens manufacturing methods according to the present invention, and the lens according to the present invention are configured, an ejector pin is not used. The lens can be released from the injection mold. Therefore, the resin leakage that has been a concern in the conventional configuration is not caused. Further, the lens can be released from the optically effective surface so as not to leave a protruding mark. In addition, it is not necessary to increase the width of the flange portion in consideration of bringing the ejector pin into contact with each other, and the width of the flange portion can be reduced, and the lens can be reduced in size.

  An embodiment of the present invention will be described with reference to FIGS. In the following description, various technically preferable limitations for carrying out the present invention are given, but the scope of the present invention is not limited to the following embodiments and drawings.

  In the following description, first, an embodiment of a lens according to the present invention will be described, and then, an injection mold used for manufacturing the lens will be described together with the manufacturing method of the lens.

  FIGS. 1A and 1B are diagrams showing the configuration of a plastic lens (lens) in the present embodiment. FIG. 1A is a side view of the plastic lens, and FIG. 1B is a plan view of the plastic lens. In the present specification, the optical axis of the plastic lens is defined as the X axis, the radial direction of the plastic lens is defined as the Y axis, and the axis perpendicular to the XY plane is defined as the Z axis. These axes are also shown in FIGS. 1 (a) and 1 (b). 1 (a) and 1 (b), together with these shafts, a movable mold (movable member) in the process of releasing the plastic lens from the mold for injection molding when manufacturing the plastic lens described later. ) Movement direction (this direction is referred to as a mold opening direction). This mold opening direction coincides with the X axis.

  As shown in FIGS. 1A and 1B, the plastic lens 19 in the present embodiment includes optically effective surfaces 11 and 12 (optically effective portions), a flange portion 13, and a protruding portion 14. .

  The optically effective surfaces 11 and 12 are convex surfaces as shown in FIG. However, the present invention is not limited to this shape, and can be formed by appropriately selecting a concave surface or a flat surface. The shapes of the optically effective surfaces 11 and 12 are not limited to spherical surfaces, and may be aspherical shapes.

  As shown in FIG. 1B, the flange 13 is provided on the outer periphery of the optical effective surfaces 11 and 12 of the plastic lens 19, and extends further outward from the outer periphery of the optical effective surfaces 11 and 12. In other words, the diameter is larger than the diameter of the optically effective surfaces 11 and 12 of the plastic lens 19.

  The flange portion 13 of this embodiment is not configured to abut the ejector pin of the injection mold as in the conventional configuration. When ejecting the plastic lens by bringing the ejector pin into contact with the flange portion as in the prior art, the Z of the flange portion is designed so that the ejector pin can contact and withstand the protrusion operation. The length (width) in the axial direction and the length (thickness) in the X-axis direction must be increased to some extent. However, in the present embodiment, since there is no such need, the size can be made smaller than that of the brim portion provided in the conventional plastic lens. In other words, the brim portion 13 of the present embodiment has a width that is too small for the ejector pin to contact.

  As shown in FIGS. 1A and 1B, the protrusion 14 is formed in the flange portion 13, and is a position facing the flange portion 13 across the lens center point P on the optical axis S. Are provided one by one. In addition, each projection 14 has a cut surface (cut surface) obtained by cutting the plastic lens 19 in the thickness direction (X-axis direction) of the plastic lens 19 at a position including the projection 14 and the center point P of the optical axis S of the lens. 1 (a) is the same as the cross-sectional view of FIG. 1A, and protrudes from the flange portion 13 in the substantially X-axis direction, and an angle of more than 0 ° and less than 90 ° with respect to the X-axis. The inclined surface 14a is inclined in a direction away from the optical axis S.

  In addition, the inclined surfaces 14a of the protrusions 14 at positions facing each other across the lens center point P are parallel to each other.

  If the size of each protrusion 14 is too large, the protrusion may interfere with a housing for mounting (for example, a lens barrel) and other lenses when the plastic lens is assembled, or it may have a negative effect on the reference when the lens is assembled. May occur. On the other hand, if it is too small, as will be described later, it is not possible to obtain a sufficient releasing effect in the releasing step when molding the plastic lens. For this reason, it is preferable that the protrusion 14 has an appropriate size. Specifically, depending on the size of the plastic lens to be molded, the width (length in the Z-axis direction), height (length in the X-axis direction), and depth (length in the Y-axis direction) of the protrusions It is preferable that the dimensions of each of the above are configured such that the minimum dimension is larger than 0.1 mm and the maximum dimension is smaller than the maximum thickness in the optical axis direction (X-axis direction) of the plastic lens.

  If the inclination angle of the inclined surface 14a with respect to the X-axis is in the above-described range, a plastic lens rotation operation (release effect) described later can be executed. On the other hand, the inclined surface is 0 ° with respect to the X axis (that is, parallel to the X axis) or 90 ° with respect to the X axis (that is, the inclined surface is parallel to the YZ plane). ) Is not preferable because the rotating operation cannot be realized. In addition, in order to implement | achieve turning operation | movement more favorably, it is preferable that it is 5 degrees or more and 75 degrees or less among the said range, and it is more preferable that it is 15 degrees or more and 45 degrees or less. .

  The plastic lens having the above-described structure is manufactured by injection molding using an injection mold. Then, next, with reference to FIG.2 and FIG.3, the method to manufacture the plastic lens 19 of this embodiment is demonstrated.

  2 (a) and 2 (b) are cross-sectional views of the injection mold according to the present embodiment, FIG. 2 (a) is an overall view thereof, and FIG. 2 (b) is a portion centered on the cavity. FIG. FIG. 3 is a side view showing a partial configuration of the injection mold.

  As shown in FIG. 2A, the injection mold 30 according to this embodiment includes a fixed mold 15 (fixed member) and a movable mold 16. The fixed mold 15 includes a fixed insert 1, a sprue bush 4, a locating ring 5, a fixed side mounting plate 11, a fixed side mold plate 6, a slag portion 31, a runner 23, a gate portion 32, a sprue 20, and a heat insulating plate 8. I have. The movable mold 16 includes a movable side mounting plate 12, a movable side mold plate 7, a movable insert 2, and a heat insulating plate 9. Of these components, the sprue bush 4, the locating ring 5, the fixed side mounting plate 11, the fixed side mold plate 6, the movable side mold plate 7, and the movable side mounting plate 12 are generally used for injection molding. Since it is the same as that provided in the mold, a detailed description is omitted.

  The fixed-side mold plate 6 of the fixed mold 15 and the movable-side mold plate 7 of the movable mold 16 are configured so as to be able to contact each other by a contact surface. A fixed insert 1 and a movable insert 2 are provided on each contact surface side, and the fixed insert 1 and the movable insert 2 are also in contact with each other. Here, contact (mold closing) and release (mold opening) of the fixed mold 15 (fixed insert 1) and the movable mold 16 (movable insert 2) are movable by a driving means (not shown). This can be done by moving the mold 16. Therefore, in FIGS. 2A and 2B, the movement axis of the movable mold 16 is indicated by the X-axis as in FIGS. 1A and 1B. That is, the X axis shown in FIGS. 1A and 1B and the X axis shown in FIGS. 2A and 2B coincide with each other, and the Y and Z axes are also shown in FIGS. The Y / Z axes in (b) coincide with the Y / Z axes in FIGS. 2 (a) and 2 (b), respectively.

  As shown in FIGS. 2A and 2B, the fixed insert 1 and the movable insert 2 are formed with depressions that become cavities 3 when they come into contact with each other. Each recess is opened to a size corresponding to the diameter of the plastic lens 19 on each contact surface of the fixed insert 1 and the movable insert 2. Further, a transfer surface (molding surface) for transferring the optically effective surfaces 11 and 12 of the plastic lens 19 is formed in each recess, and the transfer surface of each recess is in a position facing the cavity 3.

  Each recess is provided with a flange portion forming groove 10 ′ in which the flange portion 13 of the plastic lens 19 is molded.

  Furthermore, each recess is provided with protrusion-forming recesses 10a and 10b (recesses), which is a characteristic configuration of the injection mold in the present embodiment. The protrusion forming recesses 10a and 10b will be described in detail with reference to FIG.

  As shown in FIG. 2 (b), the protrusion forming recesses 10 a and 10 b constitute a part of each recess, and when the fixed insert 1 and the movable insert 2 are brought into contact with each other, the cavity 3 is formed. Will be part of

  The protrusion forming recess 10a is formed by further depression of a part of the wall of the flange forming groove 10 'in the depression on the movable nest 2 side. Further, the protrusion forming recess 10b is formed by further depression of a part of the wall of the flange forming groove 10 'in the depression on the fixed insert 1 side.

  As shown in FIG. 2B, the protrusion forming recess 10a and the protrusion forming recess 10b are formed such that the transfer surfaces of the cavity 3 in which the main part of the plastic lens 19 is molded are formed. It arrange | positions in the position which opposes on both sides of the part which opposes. That is, the positions of the protrusion forming recess 10a and the protrusion forming recess 10b coincide with the positions of the protrusions 14 of the plastic lens 19 of the present embodiment shown in FIGS. 1 (a) and 1 (b).

  Hereinafter, the protrusion forming recesses 10a and 10b will be further described with reference to FIG. 2B. For convenience of explanation, the plastic lens 19 has already been injected into the cavity 3 of FIG. 2B. As an example, the optical axis S of the plastic lens 19 and the lens center point P on the optical axis S are shown.

  The protrusion forming recess 10a has a shape that is further depressed in the X-axis direction and away from the fixed insert 1 from the wall of the groove forming groove 10 ′ in the depression on the movable insert 2 side, When viewed in the cross-sectional view of FIG. 2B, it has an inclined surface 21a that is inclined in a direction away from the optical axis S at an angle of more than 0 ° and less than 90 ° with respect to the X axis. The protrusion forming recess 10a is configured such that the cross-sectional area in the YZ plane gradually decreases from the communicating portion with the flange forming groove 10 'to the depressed end. That is, when viewed in the cross-sectional view of FIG. 2B, the protrusion forming recess 10a has a tapered structure that tapers from the communicating portion with the flange forming groove 10 ′ toward the depressed end. is doing.

  The protrusion forming recess 10b is also a shape further depressed in the direction of the X-axis direction and away from the movable insert 2 from the wall of the flange forming groove 10 'in the depression on the fixed insert 1 side, When viewed in the cross-sectional view of FIG. 2B, the inclined surface 22a is inclined with respect to the X-axis in a direction away from the optical axis S at an angle of more than 0 ° and less than 90 °. The protrusion forming recess 10b is configured such that the cross-sectional area of the YZ plane gradually decreases from the communicating portion with the flange forming groove 10 'to the depressed end. That is, when viewed in the cross-sectional view of FIG. 2B, the protrusion-forming recess 10b has a tapered structure that tapers from the communicating portion with the flange-forming groove 10 ′ toward the depressed end. is doing.

  A sprue 20 extending in the X-axis direction is provided in the sprue bush 4. As shown in FIG. 2A, the sprue 20 is a cavity having a tapered shape whose diameter increases from the fixed side mounting plate 11 toward the movable die 16. The movable mold plate 7 is provided with a groove portion that is configured as a slag portion 31 that communicates with the sprue 20 when the movable mold plate 7 contacts the fixed mold plate 6. Further, the movable mold 7 has a runner 23 and a gate 32 that communicate with the slag 31 when the movable mold 7 comes into contact with the fixed mold 6, similar to the groove configured as the slag 31. The groove part comprised as is formed. The gate portion 32 communicates with the cavity 3. As a result, when the movable side template 7 and the fixed side template 6 abut, a hollow path is formed from the open end of the spru 20 to the cavity 3 through the slag portion 31, runner 23, and gate portion 32. It will be. This hollow path becomes a filling path for the plastic lens material (resin). In other words, the plastic lens material (resin) is filled into the cavity 3 and at the same time, the sprue 20, the slag portion 31, the runner 23, and the gate portion 32 are filled with the material.

  Next, a manufacturing method of the plastic lens 19 shown in FIGS. 1A and 1B using an injection mold having the above-described configuration will be described based on FIGS. 4A and 4B. explain. 4A is a cross-sectional view showing a state where the plastic lens 19 is being molded when the injection mold 30 is closed, and FIG. 4B is a diagram of the injection mold 30. It is sectional drawing which showed the state of the plastic lens 19 at the time of mold opening.

  First, as shown in FIG. 4A, the plastic lens 19 is injection-molded as usual with an injection mold 30. A desired amount of thermosetting resin is injected into the cavity 3 from an injection nozzle (not shown). In this state, the mold is heated by a heater (not shown) to heat and cure the thermosetting resin in the cavity. At this time, it is desirable to apply a desired holding pressure to the resin in the cavity in consideration of curing shrinkage of the resin and thermal expansion of the resin due to mold heating so that the molded product has a desired shape.

  Next, as shown in FIG. 4B, the fixed mold 15 is separated from the movable mold 16, that is, the mold is opened by moving the movable mold 16 using a driving means (not shown). By exposing the contact surface 7a, the plastic lens 19 molded in the cavity 3, the gate 32 connected to the lens 19, the runner 23, and the sprue 20 appear. And the mold release operation | movement of the injection mold 30 is simultaneously performed at the time of this mold opening.

  Here, the principle of mold release of the plastic lens according to the present invention will be described. The protruding portion 14 of the plastic lens 19 is released from the injection mold 30 and comes out along the inclined surfaces 21a and 22a. At this time, the protrusions 14 formed in the protrusion-forming recesses 10a and 10b have a tapered shape similar to the shape of the protrusion-forming recesses 10a and 10b. Therefore, the direction is different from the mold opening direction (X-axis direction). When the protrusion 14 is inclined, the mold release resistance is reduced, and the mold can be removed from the mold only after the release directions are matched. For this reason, the plastic lens 19 receives a force in a direction in which the optically effective surfaces 11 and 12 are inclined as shown in FIG. As a result, the plastic lens 19 is released from the depressions 1a and 2a by this force. At this time, since the cured resin material has elasticity, it can be released without causing the plastic lens 19 to crack.

  The released plastic lens 19 is taken out by picking up a portion of the sprue 20 with a take-out robot or the like (not shown), and then the gate 13 integrated with the plastic lens 19 is cut to remove the runner 23 and the sprue 20.

  As described above, the fixed insert 1 and the movable insert 2 having the molding surfaces for molding the optically effective surfaces 11 and 12 of the plastic lens 19 are provided, and the fixed insert 1 and the movable insert 2 are provided. Injection molding of the present embodiment in which a plastic material 19 can be molded by injecting a polymerizable material into a cavity 3 having a molding surface on a wall surface, obtained by bringing the molding surfaces into contact with each other. According to the metal mold, the gate portion 32 configured so that the end portion is exposed to the cavity 3 is connected to the sprue 20 disposed in the fixed mold 15 via the runner 23, and the fixed insert. 1 and the movable nest 2 have a wall angle of the cavity 3 and an angle of more than 0 ° and less than 90 ° with respect to the moving direction of the movable mold 16 at a position different from the molding surface. Inclined inclined surfaces 21a and 22a The projection forming recesses 10a and 10b are formed.

  According to said structure, even if it is a case where a liquid resin material is injection-molded and manufacturing a lens, since there is no need to use an ejector pin, there is no possibility of causing the above resin leaks. In addition, since the lens can be released without causing the optically effective surface to stick out without causing the ejector pin to contact the flange portion, the lens flange should be considered in consideration of the contact of the ejector pin. It is not necessary to increase the width of the portion, and the width of the flange portion 13 can be reduced. Therefore, it is possible to reduce the size of the lens.

  Specifically, according to the configuration of the injection mold of this embodiment, the protrusion 14 formed by the protrusion-forming recesses 10a and 10b is moved along the inclined surfaces 21a and 22a. The mold is released in a direction different from the direction.

  As a result, the main part of the lens having the optically effective surface formed by the part having the molding surface, which is the main part of the cavity 3, rotates as a fulcrum provided outside the main part. The optically effective surfaces 11 and 12 of the lens formed by the molding surface are released from the molding surface of 1 and the movable nest 2, and as a result, the projection portion of the lens is included without using an ejector pin as in the prior art. The entire lens can be released. Here, “turn” means that the lens is such that the optically effective surfaces 11 and 12 of the lens formed by the molding surface are inclined with respect to the molding surfaces formed on the fixed insert 1 and the movable insert 2. It shows that the main part of moves.

  Of course, since it is not necessary to use an ejector pin, the resin being injected does not adhere to the ejector pin, and there is no need to worry about the slidability of the pin.

  Conventionally, the flange portion of the lens is configured to be formed to a certain extent so as not to hinder the contact operation of the ejector pin. However, according to the configuration of the present invention, it is not necessary to use the ejector pin. Therefore, it is possible to reduce the size of the lens.

  Further, even if bubbles are generated for some reason in the cavity, particularly in the molding surface, during the injection molding process, according to the configuration of the present invention, the protrusion is formed outside the main part of the cavity. Since the recesses 10a and 10b are formed, the bubbles as described above can be retracted into the protrusion-forming recesses 10a and 10b. Therefore, according to the configuration of the present invention, it is possible to provide a lens having high reliability with respect to optical performance.

  Further, according to the injection mold of the present embodiment, the protrusion forming recesses 10a and 10b are provided in the fixed insert 1 and the movable insert 2 respectively, and the two protrusions are formed. The concave portions 10a and 10b are disposed at positions facing each other across the molding surface when viewed in the moving direction of the movable member. As a result, when the mold is opened, both the projection forming recess 10b provided in the fixed insert 1 and the projection forming recess 10a provided in the movable insert 2 serve as fulcrums. The release of the lens optical effective surface can be realized with high accuracy.

  Further, as in the prior art shown in FIG. 12, the tag portion 311 is unnecessary in the present embodiment as compared with the case where a surplus portion is formed on a plastic lens having a small brim portion and then released. Therefore, the plastic lens 19 can be obtained at a lower cost.

  In addition, the protrusion provided in the flange portion of the plastic lens of the present invention is not limited to a shape that expands toward the lens outer side with respect to the lens optical axis as shown in FIGS. 1 (a) and 1 (b). For example, as shown in FIG. 5, the shape may be such that the tip portion of the tapered protrusion with respect to the lens optical axis faces inward.

Further, in the present embodiment, each of the fixed insert 1 and the movable insert 2 is provided with one protrusion forming recess, but the present invention is not limited to this, and FIGS. As shown in FIG. 4, there may be only one protrusion forming recess. Even in the case of the configuration shown in FIGS. 6 and 7, the mold is opened by moving the movable mold 16 using a driving means (not shown), and at the same time the contact surface 7a of the movable side mold plate 7 is exposed. Using the concave portion for forming the projection and the portion superposed by the sprue as a fulcrum, the plastic lens 19 receives a force in the direction in which the optically effective surfaces 11 and 12 are inclined as shown in FIG. Is released from the recesses 1a, 2a. .
In order to obtain a sufficient releasing effect, it is more effective to provide two protrusions. The shape of these protrusions is the same as that of the above-described embodiment, and the description thereof is omitted. In the embodiment, the shape is triangular from both the side view and the upper view. For example, the shape when viewed from above may be a trapezoid, and the taper structure is easy to come off when releasing. It is important to have

  Moreover, the modified example of the plastic lens of this invention is demonstrated below.

[Modification]
The plastic lens 19 ′ in FIG. 8 has a substantially spherical optically effective surface and a flange portion 13 ′ in which a part of the outer periphery is cut, and the protruding portion 14 is provided in the cut portion. The protrusion 14 is provided within the outer diameter of the flange 13 '.

  With such a configuration, in the production of the plastic lens 19 ′, it is possible to perform smooth mold release by the shearing force generated by the rotation of the protrusion 14 in the mold opening process at the time of mold release. Further, when assembling a built-in lens such as an imaging system, the upper surface and the side surface of the collar portion 13 ′ can be handled in the same manner as a normal lens using the alignment portion.

In addition, it can be said that the lens manufacturing method according to the present invention is characterized by the following configuration.
That is, the lens manufacturing method according to the present invention is a method of manufacturing a plastic lens obtained by filling a mold cavity with a polymerizable resin, solidifying the mold, and then releasing the mold from the cavity. In other words, it can be said that the plastic lens is released from the mold by a rotation operation using a minute projection provided outside the optically effective surface as a fulcrum. In the above configuration, it is preferable that the release direction of the minute protrusions is different from the mold opening direction of the mold. In the above configuration, the polymerizable resin is preferably a liquid thermosetting resin.

In other words, the lens according to the present invention is characterized by the following configuration.
That is, the lens according to the present invention is a plastic lens obtained by filling a mold cavity with a polymerizable resin and solidifying, and then releasing from the cavity. The plastic lens is an optically effective surface of the plastic lens. In other words, it is characterized by having a microprotrusion outside. In other words, the following can also be said. That is, another lens according to the present invention is a plastic lens obtained by filling a mold cavity with a polymerizable resin and solidifying it, and then releasing from the cavity. The plastic lens is an optical component of the plastic lens. In other words, at least a part outside the effective surface has a shape cut in the direction of the optical axis, and has a minute protrusion on the side surface outside the cut optical effective surface. In the above configuration, it is preferable that at least one or more microprojections are provided. In the above configuration, it is preferable that the fine protrusion has a tapered shape whose diameter increases toward a substantially flat surface outside the optically effective surface of the plastic lens. In the above configuration, it is preferable that the minute protrusions are provided so as to be inclined with respect to the optical axis direction of the plastic lens. In the plastic lens having the above-described configuration and having two or more microprotrusions, the two or more microprotrusions are preferably disposed at positions facing the optical axis as a center. In the plastic lens having the above-described configuration and having two or more microprotrusions, it is preferable that the mold release directions of the microprotrusions arranged at the opposed positions are parallel to each other. In the above configuration, it is preferable that the minute protrusions provided on the side surface outside the cut optical effective surface are provided within the shape dimensions before cutting outside the optical effective surface of the plastic lens. In the above configuration, the microprojections have a minimum dimension greater than 0.1 mm and a maximum dimension that is the maximum in the optical axis direction of the plastic lens. It is preferable to be configured in a range smaller than the thickness.

  The mold for injection molding of the present invention, the method for producing a lens using the mold, and the lens can perform mold release without using an ejector pin as in the prior art. A highly reliable lens can be provided without causing leakage of the lens material (resin) into the mold.

  Therefore, it can be applied to various lenses manufactured by injection molding.

(A) * (b) is the figure which showed the structure of the plastic lens which is one Embodiment of the lens based on this invention, (a) is a side view of a plastic lens, (b) is a plastic lens FIG. (A) * (b) is sectional drawing which showed one Embodiment of the injection mold which concerns on this invention, (a) is the whole figure, (b) is the mold for injection molding It is sectional drawing which showed the structure of the cavity which is the principal part of. FIG. 3 is a side view showing a partial configuration of the injection mold shown in FIG. 2. FIG. 3 shows a state in which the lens shown in FIG. 1 is manufactured using the injection mold shown in FIG. 2, and (a) shows a state when the mold of the injection mold is closed. FIG. 2 is a cross-sectional view showing a state during molding of the lens, and FIG. 4B is a cross-sectional view showing a state of the lens when the injection mold is opened. (A) * (b) is the figure which showed the structure of the plastic lens which is other embodiment of the lens based on this invention, (a) is a side view of a plastic lens, (b) is plastic It is a top view of a lens. (A) * (b) is the figure which showed the structure of the plastic lens which is other embodiment of the lens based on this invention, (a) is a side view of a plastic lens, (b) is plastic It is a top view of a lens. (A) * (b) is the figure which showed the structure of the plastic lens which is other embodiment of the lens based on this invention, (a) is a side view of a plastic lens, (b) is plastic It is a top view of a lens. (A) * (b) is the figure which showed the structure of the plastic lens which is other embodiment of the lens based on this invention, (a) is a side view of a plastic lens, (b) is plastic It is a top view of a lens. It is the figure which showed the prior art. It is the figure which showed the prior art. It is the figure which showed the prior art. It is the figure which showed the prior art.

Explanation of symbols

1 Fixed insert (fixed member)
2 Movable insert (movable member)
3 Cavity 4 Sprue Bush 5 Locating Ring 6 Fixed Side Plate 7 Movable Side Plate 7a Abutting Surface 8 Heat Insulating Plate 9 Heat Insulating Plate 10 ′ Groove 10a, 10b Head Forming Grooves 10
11.12 Effective optical surface 13 Collar portion 14 Protruding portion 14a Inclined surface 15 Fixed type (fixing member)
16 Movable type (movable member)
19 Plastic lens 20 Sprue 21a, 22a Inclined surface 23 Runner 30 Injection mold 31 Slag part 32 Gate part

Claims (16)

A fixed member and a movable member having a molding surface for molding the optically effective surface of the lens;
The movable member is configured to move in a predetermined direction so that the movable member can be brought into contact with or released from the fixed member,
Obtained by bringing the fixed member and the movable member into contact with a cavity having the molding surface on the wall surface, obtained by bringing the fixed member and the movable member into contact with each other with the molding surfaces facing each other. An injection mold capable of molding a lens by injecting a polymerizable material via a gate portion communicating with the cavity and a runner communicating with the gate portion,
The fixed member or the movable member is provided with a sprue communicating with the runner,
The fixed member or the movable member has an inclined surface that is inclined at a predetermined angle with respect to the moving direction of the movable member at a position different from the molding surface on the wall surface of the cavity. An injection mold characterized in that a concave portion is formed. A fixed member and a movable member having a molding surface for molding the optically effective surface of the lens;
The movable member is configured to move in a predetermined direction so that the movable member can be brought into contact with or released from the fixed member,
Injection in which a lens can be molded by injecting a polymerizable material into a cavity having a molding surface on a wall surface, obtained by bringing the fixed member and movable member into contact with each other with the molding surfaces facing each other. A mold for molding,
The fixed member and the movable member have an inclined surface that is inclined at a predetermined angle with respect to the moving direction of the movable member at a position different from the molding surface on the wall surface of the cavity. An injection mold characterized in that a concave portion is formed.   Each of the recesses is provided on each of the wall surfaces of the cavity on the fixed member side and the movable member side, and the two recesses are mutually viewed from the direction perpendicular to the molding surface. The injection mold according to claim 2, wherein the mold is disposed at a position facing each other across the molding surface.   The injection mold according to any one of claims 1 to 3, wherein the predetermined angle is greater than 0 ° and less than 90 °.   5. The flange forming portion extending in a direction perpendicular to the moving direction of the movable member is provided at a position different from the molding surface on the wall surface of the cavity. Item 2. An injection mold according to item 1.   6. The injection mold according to claim 5, wherein the recess is provided in a brim part forming part. A lens manufacturing method for manufacturing a lens, which is a polymer of the polymerizable material, using the injection mold according to claim 1,
An injection step of injecting and filling a polymerizable material into the cavity formed by bringing the fixed member and the movable member into contact with each other;
A contact release step of releasing contact between the fixed member and the movable member by moving the movable member after the injection step;
In the contact release step, the lens is adjusted so that the optically effective surface is inclined with the portion superposed on the concave portion and the portion superposed on the sprue as fulcrums according to the movement of the movable member. A method of manufacturing a lens, wherein the lens is rotated and released from the fixed member and the movable member. A lens manufacturing method for manufacturing a lens, which is a polymer of the polymerizable material, using the injection mold according to claim 2,
An injection step of injecting and filling a polymerizable material into the cavity formed by bringing the fixed member and the movable member into contact with each other;
A contact release step of releasing contact between the fixed member and the movable member by moving the movable member after the injection step;
In the contact release step, the lens rotates so that the optically effective surface is inclined with the overlapped portion of the concave portion as a fulcrum according to the movement of the movable member, and the fixed member and the A lens manufacturing method, wherein the mold is released from the movable member.   9. The lens according to claim 7, wherein, in the contact release step, a portion overlapped by the concave portion is released in a direction different from a moving direction of the movable member along the inclined surface. Production method.   The lens manufacturing method according to any one of claims 7 to 9, wherein a thermosetting resin is used as the polymerizable material. Protruding part outside the optically effective part in the lens,
When the cut surface obtained by cutting the lens in the thickness direction of the lens is viewed at a position including the center point on the optical axis of the optically effective portion, the protrusion has a 0 ° with respect to the optical axis. And an inclined surface that is inclined at an angle of less than 90 °. The protrusion is disposed at a position facing the center point when the cut surface is viewed,
The lens according to claim 11, wherein the inclined surfaces provided on the opposing projecting portions are parallel to each other.   The lens according to claim 11 or 12, further comprising a collar portion outside the optically effective portion.   The lens according to claim 13, wherein the protrusion is disposed on the flange portion.   The lens according to any one of claims 11 to 14, wherein the protrusion has a triangle whose protrusion end has an acute angle when the cut surface is viewed.   The lens according to claim 11, wherein the lens is a plastic lens.

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