JP2008265106A - Mold, molding device, intermediate molded form, and optics - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold which can easily form an optics using a low-viscosity resin, for example, and a molding device, an intermediate molded form and the optics. <P>SOLUTION: Core members 10 an 20 have a surface formed in a piece, with which a heat-curing resin comes into contact, so that the surface has no gap through which the low-viscosity heat-curing resin leaks. Consequently, it is possible to mold a high precision optics. In addition, a release failure due to the mingling of the cured resin and a molding resin in a piece, within a fitting gap, does not occur. Further, the maintenance service for removing the interlocking resin in the fitting gap, is no longer necessary. Thus the highly efficient molding can be realized and the molded form with high quality level and high performance can be obtained at a low cost. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technique for molding an optical element, and particularly relates to a mold, a molding apparatus, an intermediate molded body, and an optical element for molding an optical element using an energy curable resin.

In recent years, it has been common practice to mount an imaging device on a mobile phone or the like. A general imaging device is configured to join an optical element such as a lens on a substrate and form a subject image on a light receiving surface of a solid-state imaging element via the optical element. By the way, in order to simplify the manufacturing process, there is a demand for passing through a high-temperature solder reflow bath with an optical element mounted on a substrate. However, acrylics and polycarbonates currently used as materials for optical elements have low heat resistance, and there is a problem that they easily melt and deform when passed through a high-temperature solder reflow bath. On the other hand, for example, a thermosetting resin as shown in Patent Document 1 tends to flow when heated to decrease its viscosity, but once heated and solidified, its shape is maintained even at higher temperatures. It has the characteristics. The photo-curable resin is also in a liquid state when not exposed to light, but has a characteristic of maintaining its shape even at a high temperature once solidified by exposure to light. Therefore, if a thermosetting resin or a photocurable resin is used, an optical element that can be passed through a solder reflow bath can be molded.
Japanese Patent Laid-Open No. 2004-197090

  Here, one of the problems when molding using energy curable resins typified by thermosetting resins and photocurable resins is that energy curable resins are generally liquid at room temperature. However, since the viscosity is low, it is easy to leak from the gap between the mold parts during molding, and the molding pressure cannot be increased. Another problem is that once the energy curable resin is solidified in the gap between the mold parts, it takes time to remove it.

  The present invention has been made in view of the problems of the prior art. For example, a mold, a molding apparatus, an intermediate molded body, and an optical element that can easily mold an optical element using a resin having a low viscosity are provided. The purpose is to provide.

The mold according to claim 1 is a mold having a plurality of first optical surface transfer surfaces, wherein the second optical surface transfer surface disposed opposite to each first optical surface transfer surface is provided. In a mold that molds an optical element by supplying resin to a cavity formed between both molds, which is matched to a plurality of opposed molds,
At least the surface with which the resin supplied to the cavity comes into contact is formed integrally.

  For example, when molding using energy curable resin, etc., it has a low viscosity at room temperature and can be supplied into the mold in a liquid state. By injecting into the cavity while applying pressure, it adheres to the optical surface transfer surface during solidification. Therefore, generation of bubbles and the like that deteriorate the quality can be suppressed, and a highly accurate optical element can be molded. However, if there is a gap in the mold, the resin leaks from the gap, and there is a problem that sufficient pressurization cannot be performed. On the other hand, according to the present invention, by forming at least the surface of the mold that comes into contact with the resin supplied to the cavity, it is possible to eliminate the gap and prevent the resin from leaking, and to provide a highly accurate optical element. Molding can be performed. Further, there is no problem that the resin hardened in the fitting gap and the molded resin are integrated to cause a mold release failure, and further maintenance such as removing the resin fixed in the fitting gap is not required. Thereby, extremely efficient molding can be realized, and a low-cost, high-quality and high-performance molded product can be obtained. In addition, since the “surface formed integrally” means a surface having no gap between joints generated when a plurality of parts are combined, even a surface composed of a plurality of parts is welded. The surfaces joined with no gaps are the surfaces formed integrally.

  “Optical elements” include, for example, lenses, prisms, diffraction grating optical elements (diffraction lenses, diffraction prisms, diffraction plates), optical filters (spatial low-pass filters, wavelength band-pass filters, wavelength low-pass filters, wavelength high-pass filters, etc.), polarized light Examples include filters (analyzers, optical rotators, polarization separation prisms, etc.) and phase filters (phase plates, holograms, etc.), but are not limited thereto.

  A mold according to a second aspect is characterized in that, in the invention according to the first aspect, the resin is an energy curable resin. Examples of the energy curable resin include a thermosetting resin and an ultraviolet curable resin. Since the thermosetting resin is cured by heating, it can be solidified by supplying a thermosetting resin that is liquid at room temperature into a heated mold. On the other hand, ultraviolet curable resin is cured by irradiating with ultraviolet rays, so after supplying ultraviolet curable resin that is liquid at room temperature into a transparent mold, it is solidified by irradiating ultraviolet rays from the outside. Can do.

  According to a third aspect of the present invention, in the invention of the second aspect, the energy curable resin has a viscosity before curing of 100 (poise) or less. The energy curable resin having a low viscosity has good flowability and can maintain a high molding pressure by applying pressure from the outside. Therefore, the resin can be cured by pressing the resin onto the optical surface transfer surface at a high pressure. It is possible to obtain a high-quality and high-performance optical element excellent in mold shape transferability.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the center of the first optical surface transfer surface is a first circle centered on one point on the surface of the mold. It is arranged on the circumference. Thus, a mold having a plurality of optical surface transfer surfaces whose centers are arranged on the first circumference can be efficiently processed by a lathe as described later. For this reason, it is possible to reduce the die machining cost and the machining time.

  The mold according to claim 5 is the invention according to any one of claims 1 to 3, wherein the center of the first optical surface transfer surface is a first circle centered on one point on the mold surface. At least two on the circumference, and on the same surface as the first circumference, the same center as the first circumference, and a second radius different from the first circumference. Since at least two are arranged on the circumference, it is possible to perform more efficient machining, and it is possible to realize a reduction in die machining cost and a significant reduction in machining time.

  In addition, if the arrangement on the circumference of the optical surface transfer surface is an equal interval (equal angle), for example, when turning the optical surface transfer surface, the core member is rotated by a certain angle each time, and the next processing surface is moved. Since it only needs to be positioned at the center of rotation of the main spindle of the lathe, it is easy as work, and machining errors can be reduced. However, the scope of the present invention is not limited to this, and the optical surface transfer surface is on the circumference of the core member, but may not be arranged at equal intervals (the present angle). For example, by appropriately selecting the angle of the optical surface transfer surface, the optical surface transfer surfaces on concentric circles can be arranged on a substantially straight line. In such a case, in the turning process, the core member must be rotated at a different angle each time during surface processing, which is a complicated operation, but when cutting the optical surface transfer surface formed by this mold into individual pieces, Therefore, there is a merit that work can be easily performed because the blade can be passed through. Therefore, the arrangement of the optical surface transfer surfaces on the circumference does not need to be equidistant (equal angle), and the fact that they are arranged on the circumference is a particularly important matter in the present invention.

  According to a sixth aspect of the present invention, in the invention according to the fourth or fifth aspect, a supply path extending from the outside is provided toward the center of the circumference, and the mold is pressurized through the supply path. The resin is supplied to the cavity. When the resin is supplied through the supply path, the resin can be supplied radially to each first optical surface transfer surface and each second optical surface transfer surface. The flow path length of the resin to the surface and each second optical surface transfer surface becomes equal. As a result, the molding conditions of each optical element to be transferred can be made uniform, the correspondence between the molding conditions and the molding results can be clarified, and molding errors can be reduced, so that strict molding conditions can be set. A uniform high-performance optical element can be obtained.

  According to a seventh aspect of the present invention, in the invention according to the fourth or fifth aspect, the supply path extending from the outside is provided on the outer side in the radial direction of the circumference, and the mold is pressurized via the supply path. The formed resin is supplied to the cavity. When the mold opens vertically (vertically), the flow of resin into the cavity becomes rotationally symmetric and becomes uniform, reducing unevenness in molding conditions and variations, but the mold is horizontally oriented (horizontally). When opened, the cavity array is vertical. When such a mold is filled with resin from the center side of the circumference, since the viscosity is low, the resin temporarily accumulates in the lower cavity due to gravity, and is filled so that the resin interface gradually rises with filling. Therefore, when the resin is filled from the center side of the circumference, the resin flows in the first half of the cavity due to free fall in the cavity, which is basically non-uniform and may involve bubbles. On the other hand, in the mold that opens in the horizontal direction, if the lower part in the direction of gravity is known in advance, the supply path is provided under the cavity from the beginning, and if the resin is filled from here, it is uniform in one direction. A good resin flow without entrapment of bubbles.

  The mold according to claim 8 is the invention according to any one of claims 1 to 7, wherein the mold includes a first core member having the first optical surface transfer surface, and the first core member. A first holding member that holds the core member, and the first core member faces the second core member having the second optical surface transfer surface provided in the counter mold. The first holding member is in contact with the second holding member that holds the second core member provided in the counter mold, and is in surface contact with the second holding member. The first core member and the first holding member constitute a mold according to the present invention, and the first holding member and the second holding member are also subjected to pressure during mold clamping. Thus, there is no need to form a first optical surface transfer surface that directly transfers a high-precision optical surface to a large mold part, and the first center is arranged along the circumference of a small radius. Since the optical surface transfer surface only needs to be processed into the first core member, the equipment such as processing machines can be kept small, the space can be used effectively, the capital investment can be reduced, and the mold production cost can be reduced. Can be reduced.

  The mold according to claim 9 is the invention according to any one of claims 1 to 7, wherein the mold includes a first core member having the first optical surface transfer surface, and the first core member. A first holding member that holds the core member, and the first core member faces the second core member having the second optical surface transfer surface provided in the counter mold. The first holding member is in contact with the second holding member that holds the second core member provided in the opposing mold, but is not in surface contact. When the mold and the opposing mold are combined, only the first core member and the second core member are brought into surface contact with each other and are pressed against each other. Tilt eccentricity between the first optical surface transfer surface and the second optical surface transfer surface facing the first optical surface transfer surface is suppressed, and a high-precision cavity with high coaxiality is formed, thereby forming a high-precision optical element. . Further, since the pressing area can be reduced by limiting the optical surface transfer surface to the mating surface of the core member arranged along the circumference, the surface pressure of the mating surface is increased and sealing of the resin supplied under pressure is performed. There is also an effect that the effect is increased and it is difficult to leak. If the resin does not leak easily, the molding pressure can be maintained high, and the reproducibility of the molding pressure can also be maintained at a high level. A high-quality optical element can be obtained with high efficiency.

The molding apparatus according to claim 10 includes a first core member having a plurality of first optical surface transfer surfaces, and a second optical surface transfer surface disposed to face each first optical surface transfer surface. A second core member having a plurality of the first core member and a cavity formed between the first core member and the second core member in a state where the first core member and the second core member are combined. A molding apparatus that molds an optical element by supplying resin through a supply path formed in a member or the second core member,
In at least one of the core members, a surface with which the resin supplied to the cavity comes into contact is formed integrally.

  According to the present invention, at least one surface of the core member that contacts at least the resin supplied to the cavity is integrally formed, thereby eliminating a gap and suppressing leakage of the resin. Can be formed. Further, there is no problem that the resin hardened in the fitting gap and the molded resin are integrated to cause a mold release failure, and further maintenance such as removing the resin fixed in the fitting gap is not required. Thereby, extremely efficient molding can be realized, and a low-cost, high-quality and high-performance molded product can be obtained.

  According to an eleventh aspect of the present invention, in the invention according to the tenth aspect, the resin is an energy curable resin.

  According to a twelfth aspect of the present invention, in the invention of the eleventh aspect, the energy curable resin has a viscosity before curing of 100 (poise) or less.

  According to a thirteenth aspect of the present invention, in the invention according to any one of the tenth to twelfth aspects, the center of the first optical surface transfer surface is centered on one point on the surface of the first core member. It is arranged on the first circumference.

  According to a fourteenth aspect of the present invention, in the invention according to any one of the tenth to twelfth aspects, the center of the first optical surface transfer surface is centered on one point on the surface of the first core member. At least two are arranged on the first circumference, are on the same surface as the first circumference, have the same center as the first circumference, and have a first circumference and a radius that are the same. It is characterized in that at least two are arranged on different second circumferences.

  The molding apparatus according to claim 15 is the invention according to claim 13 or 14, wherein the first core member is provided with a supply path extending from the outside toward the center of the circumference, The resin pressurized through the supply path is supplied to the cavity.

  According to a sixteenth aspect of the present invention, in the invention according to the thirteenth or fourteenth aspect, the first core member is provided with a supply path extending from the outside outward in the radial direction of the circumference. The pressurized resin is supplied to the cavity through the supply path.

  According to a seventeenth aspect of the present invention, in the invention according to the thirteenth or fourteenth aspect, the first core member is formed with a through hole extending toward the center of the circumference, and the second core member. In the core member, a recess is formed facing the through hole, and in a state where the first core member and the second core member are combined, liquid resin is stored in the recess, By pressing the resin in the concave portion with a piston member that slides with respect to the through hole, the pressurized resin is supplied to the cavity through the supply path.

  The molding apparatus according to claim 18 is the invention according to any one of claims 10 to 17, wherein a first holding member that holds the first core member and a second holding member that holds the second core member. Two holding members, the first core member is in surface contact with the second core member, and the first holding member is in surface contact with the second holding member. It is characterized by doing.

  A molding apparatus according to a nineteenth aspect is the invention according to any one of the tenth to seventeenth aspects, wherein a first holding member that holds the first core member and a second holding member that holds the second core member. The first core member is in surface contact with the second core member, but the first holding member is in surface contact with the second holding member. It is characterized by not.

  A molding apparatus according to claim 20 is characterized in that, in the invention according to any one of claims 10 to 19, a sealing member is disposed between the first core member and the second core member. To do. As long as the split mold is used as in the molding apparatus of the present invention, it is inevitable that a mold mating surface is formed. By improving the accuracy of the mating surfaces, the gap can be kept small, but if the viscosity of the supplied resin is low and the pressure is high, there is still a risk of leakage. On the other hand, as in the present invention, by arranging a sealing member between the first core member and the second core member, resin leakage from the mating surface of the mold can be prevented, and molding is performed. Since the pressure can be maintained higher, the resin can be pressed against the optical surface transfer surface at a high pressure to be solidified, and a high-quality and high-performance optical element excellent in transferability of the optical surface transfer surface shape can be obtained.

  According to a twenty-first aspect of the present invention, in the invention according to the twentieth aspect, the sealing member has a ring shape that surrounds the plurality of first optical surface transfer surfaces and the second optical surface transfer surfaces. It is characterized by that. By sealing the outside of the first optical surface transfer surface and the second optical surface transfer surface collectively with the sealing member, it is possible to reliably seal a resin with low viscosity, and the sealing member is also minimal Therefore, high molding pressure can be maintained at low cost and molding reproducibility can be improved. As a sealing member, the cross-sectional shape may be an O-ring shape or a C shape. The material of the sealing member may be a polymer material such as nylon, viton, nitrile rubber, silicon resin, or epoxy, or may be a soft metal such as copper, aluminum, or lead.

  According to a twenty-second aspect of the present invention, in the invention according to the twentieth or twenty-first aspect, the first core member is aligned with the third core member before the second core member is aligned, and the first core member is aligned with the second core member. The sealing member is formed on the first core member by supplying resin between the first core member and the third core member.

  According to the present invention, the sealing member is first formed on the first core member by the first core member and the third core member. When the second core members are combined, a sealing member is interposed between them, and the resin having a low viscosity is suppressed from leaking from the mating surface of the mold. For example, compared with the case where the sealing member is separately molded and bonded, the number of steps for positioning and bonding the parts can be reduced, and the cost reduction effect is great.

  The intermediate molded body according to claim 23 is an optical element having an optical surface molded from the optical surface transfer surface in a state where the intermediate molded body is molded by the molding apparatus according to any one of claims 10 to 22. The optical element adjacent to it is connected by a resin material.

  An optical element according to a twenty-fourth aspect is manufactured by cutting the intermediate molded body according to the twenty-third aspect.

  ADVANTAGE OF THE INVENTION According to this invention, the metal mold | die which can shape | mold an optical element easily, for example using low viscosity resin, a shaping | molding apparatus, an intermediate molded object, and an optical element can be provided.

  Embodiments of the present invention will be described below with reference to the drawings. First, the manufacturing method of the metal mold | die concerning this Embodiment is described. FIG. 1 is a perspective view showing a state in which the core member according to the present embodiment is held by a jig J. FIG. In FIG. 1, a jig J having a cylindrical shape has two cylindrical openings J1 and J2 on one surface. A cylindrical core member (first core member) 20 made of super steel or the like is accommodated in the opening J1, and is rotated at predetermined angular pitches in the opening J1 using an index device (not shown). Arranged to be possible. On the other hand, the counter balance CB having a mass corresponding to the core member 20 is accommodated in the opening J2. The core member 20 may be previously formed with a central supply path 22, a horizontal supply path 24 (FIG. 3), and the like, but the surrounding optical surface transfer surface (first optical surface transfer surface) 21 is It shall be raw.

  FIG. 2 is a perspective view of an X-, Y-, Z-, and θ-axis super-precision lathe for processing the core member according to the present embodiment. In FIG. 2, a rotation support unit 109 is installed on a Z-axis stage 105 that is movable in the Z-axis direction with respect to the surface plate 110, and the core member 20 is mounted on a chuck 109a that the rotation support unit 109 rotates. The jig J is held. On the other hand, on an X-axis stage 106 that is movable in the X-axis direction that intersects the Z-axis direction with respect to the surface plate 110, a Y-axis stage 107 that is movable in the Z-axis direction and the Y-axis direction that intersects the X-axis direction. Is arranged, and a diamond tool 113 is attached to the Y-axis stage 107. The X-axis stage 106, the Y-axis stage 107, the Z-axis stage 105, and the rotation support unit 109 are independently controlled by the NC program, and the core member 20 and the diamond tool 113 are moved relative to each other. The optical surface transfer surface 21 is processed.

  More specifically, the processing mode will be described. When the jig J to which the core member 20 is attached is held on the chuck 109a, the chuck 109a is positioned at a position shifted from the axis AX (FIG. 1) of the core member 20. A rotation axis RX (FIG. 2) is arranged. Therefore, when the diamond tool 113 is moved closer while rotating the chuck 109a, the optical surface transfer surface 21 is formed by turning at a position away from the axis AX of the core member 20. When one optical surface transfer surface 21 is formed, another optical surface transfer is performed by rotating the core member 20 at a predetermined angle pitch (for example, 45 degrees) in the opening J1 by an index device (not shown) and turning similarly. A surface 21 is formed. A plurality of optical surface transfer surfaces can be formed on the end surface of the core member 20 while sequentially turning in this way.

  When forming a plurality of optical surface transfer surfaces 21 on the end surface of the core member 20, for example, by performing end mill cutting using an expensive multi-axis processing machine having four or five axes, a plurality of optical surfaces arranged in a matrix form The transfer surface can also be formed arbitrarily, but processing takes time. On the other hand, as shown in FIG. 2, if processing is performed in a state in which the axis of the optical surface transfer surface coincides with the rotation axis RX of the chuck 109a, a general-purpose processing machine having two or three axes is used. Centering on the axis AX of the core member 20, the center of the plurality of optical surface transfer surfaces 21 can be arranged on the same circumference, and an expensive multi-axis processing machine having four or five axes is used. Compared with the conventional end mill cutting process, the surface roughness of the optical surface transfer surface can be obtained more efficiently with a processing time of 1/10 or less and more than 3 times smoother, and the variation in shape between the optical surface transfer surfaces is also possible. It can be suppressed as much as possible.

  9 and 10 are perspective views showing a state in which a core member according to a modification of the present embodiment is held by a jig J '. In the jig J ′ according to this modification, an opening J <b> 1 ′ is formed such that cylinders having the same diameter and parallel axes are overlapped. Therefore, the cylindrical core member 20 can be selectively attached to the opening J1 'at the position shown in FIG. 9 and the position shown in FIG. Further, in the space other than the core member 20 in the opening J1 ', as shown by hatching, a counterbalance CB1 having a crescent cross section is mounted. The position of the counter balance CB1 is reversed between the position shown in FIG. 9 and the position shown in FIG.

  According to the present embodiment, by using the jig J ′, first, in the state shown in FIG. 9, on the first circumference of the radius R around the axis AX of the core member 20 as described above. Turning can be performed so that the centers of the plurality of optical surface transfer surfaces 21 are arranged. Subsequently, the core member 20 is replaced, and in the state shown in FIG. 10, the centers of the plurality of optical surface transfer surfaces 21 ′ are centered on the second circumference having the radius R / 2 around the axis AX of the core member 20. Can be turned to place. Thereby, on the surface of the core member 20, the optical surface transfer surfaces 21 and 21 ′ arranged in two rows around the axis AX can be formed, and a large number of optical elements can be efficiently molded by one core member 20. The means for positioning the core member 20 with respect to the jig J ′ is not limited to the above-described mode. For example, the opening J1 ′ of the jig J ′ is a long hole, and the core member 20 disposed therein is finely moved. It may be displaced on the stage. A plurality of openings having the same diameter as the core member 20 may be provided at different distances from the center of the jig J ′.

  FIG. 3 is a schematic view showing a process of molding an optical element by a molding apparatus including a core member according to the present embodiment. The core member 20 formed as described above is held by the holding member (first holding member) 60 and is held by the molding apparatus. On the other hand, the core member (second core member) 10 on which the optical surface transfer surface (second optical surface transfer surface) 11 is similarly formed is held by the holding member (second holding member) 70, The molding apparatus holds the core member 10 so as to face the core member 10. At this time, the optical surface transfer surfaces 11 and 21 are aligned so that their axes coincide with each other. In addition, the core member 20, the holding member 60, and the 1st metal mold | die are comprised, and the core member 10, the holding member 70, and the 2nd metal mold | die are comprised. In the following example, the step portion 23 is formed on the outer periphery of the core member 20, but this can be formed by a normal lathe.

  The process of molding the optical element will be described. Here, the temperature of the cavity formed between the core members 10 and 20 can be measured by the core member 10 or a thermistor (not shown) disposed in the core member 20.

  First, as shown in FIG. 3A, a ring-shaped sealing member 30 is placed on the upper surface of the step portion 23 of the core member 20 so as to surround the optical surface transfer surface 21, and above the core member. 10 and the holding member 70 are set. Thereafter, as shown in FIG. 3B, the core member 10 is brought into close contact with the core member 20 via the sealing member 30, and the mold is clamped with a predetermined holding pressure. At this time, only the lower surface of the core member 10 and the upper surface of the core member 20 are in surface contact with each other and the holding members 60 and 70 are not in contact with each other. , 21 is suppressed, and a high-precision cavity with high coaxiality is formed, whereby a high-precision optical element is formed. Further, since the pressing area can be reduced by limiting to the mating surfaces of the core members 10 and 20, the surface pressure of the mating surfaces is increased, and the sealing effect of the thermosetting resin supplied under pressure is increased and the leakage is less likely to occur. There is also an effect. If the resin does not leak easily, the molding pressure can be maintained high, and the reproducibility of the molding pressure can be maintained at a high level, so that the thermosetting resin is strongly pressed against the optical surface transfer surfaces 11 and 21 without variation. As a result, high-precision and high-quality optical elements can be obtained with high efficiency.

  Further, since the sealing member 30 is elastically deformed between the core member 10 and the core member 20, even if the liquid thermosetting resin is filled in the cavity while being pressurized, it leaks from the mating surfaces of the core members 10 and 20. It is suppressed.

  Further, the core member 10 and the holding member 70 and the core member 20 and the holding member 60 are heated by the heater 50. In addition, a nozzle N that can discharge liquid thermosetting resin while being pressurized is connected to the supply path 22 of the core member 20. The nozzle N is supplied with a thermosetting resin from a source (not shown) while being pressurized to a predetermined pressure.

  Here, with reference to FIG. 3C, an optical surface transfer in which a thermosetting resin having a low viscosity (viscosity before curing is 100 (poise) or less) is arranged from the nozzle N on the same circumference. It inject | pours between the optical surface transfer surfaces 11 and 21 via the supply path 22 extended toward the center of the surfaces 11 and 21, and the horizontal supply path 24 extended horizontally from it. At this time, since the core members 10 and 20 are integrally formed with the contact surface of the thermosetting resin, there is no gap through which the thermosetting resin having a low viscosity leaks. It can be carried out. Further, there is no problem that the resin hardened in the fitting gap and the molded resin are integrated to cause a mold release failure, and further maintenance such as removing the resin fixed in the fitting gap is not required. Thereby, extremely efficient molding can be realized, and a low-cost, high-quality and high-performance molded product can be obtained.

  By heating in the cavity, the thermosetting resin solidifies in a state where the shape of the optical surface transfer surfaces 11 and 21 is transferred, and then the heating operation of the heater 50 is stopped to lower the cavity temperature and increase the molding pressure. Reduce to atmospheric pressure.

  Thereafter, when the core member 10 and the holding member 70 are moved upward to perform mold opening, the resin molded product (intermediate molded product) M molded so that the flange portion is in close contact with the sealing member 30 is exposed. Therefore, as shown in FIG. 3D, the resin molded product M attached to the sealing member 30 can be removed together by removing the sealing member 30 from the core member 20. The resin molded product M can be easily separated from the sealing member 30 and further cut out at a predetermined position to obtain a plurality of optical elements OE to which the shapes of the optical surface transfer surfaces 11 and 21 are transferred. Thus, one cycle of optical element molding is completed.

  In addition, you may make it receive the pressure at the time of a mold clamping also in the holding members 60 and 70 in the state which match | combined the core members 10 and 20. FIG. This eliminates the need to form an optical surface transfer surface directly on a large mold part, and the optical surface transfer surfaces 11 and 21 may be processed into the core members 10 and 20 along the same circumference with a small radius. , Equipment such as processing machines can be kept small, space can be used effectively, equipment investment can be reduced, and mold production costs can be reduced.

  FIG. 4 is a schematic diagram illustrating a molding process of an optical element in a molding apparatus according to another embodiment. In the present embodiment, in order to simplify the description, the optical surface transfer surface surrounded by the sealing member is shown as a pair of upper and lower sides. The holding member is also omitted. The second core member 10 and the third core member 40 are attached to the lower end of the rotational drive shaft RS.

  First, as shown in FIG. 4A, the rotary drive shaft RS is rotated so that the third core member 40 is opposed to the first core member 20 installed on a surface plate (not shown). Position. Thereafter, the rotary drive shaft RS is lowered to bring the third core member 40 into close contact with the first core member 20. At this time, the processing surface for the optical element of the first core member 20 (including the optical surface transfer surface and the flange transfer surface, 10a as well) 20a has a processing surface of the third core member 40 having a corresponding shape. 40a adheres. An annular space A is formed around the periphery.

  Here, while the first core member 20 and the third core member 40 are heated by a heater (not shown), a resin (here, a thermoplastic resin) melted from the outside through a supply path (not shown) is annular. Fill space A. However, since the processing surface 40a of the third core member 40 is in close contact with the processing surface 20a for the optical element, the resin does not enter between them, and only the ring-shaped sealing member 30 is formed as a molded product. It will be. Further, since the viscosity of the thermoplastic resin at the time of cavity injection is relatively high, there is little risk of leakage from the divided surfaces of the core members 20 and 40.

  After the thermoplastic resin is solidified, the rotational drive shaft RS is raised and further rotated 180 degrees so that the second core member 10 faces the first core member 20. Thereafter, the rotary drive shaft RS is lowered to bring the second core member 10 into close contact with the first core member 20 (see FIG. 4B). At this time, the sealing member 30 is disposed between the first core member 20 and the second core member 10 with a predetermined surface pressure in a state where the sealing member 30 is disposed around the processing surfaces (optical surface transfer surfaces) 20a and 10a. It will be in close contact. Here, the distance between the first core member 20 and the second core member 10 is changed by adjusting the press pressure applied via the rotational drive shaft RS within the elastic deformation region of the resin. Thereby, the axial thickness of the optical element after being molded can be adjusted.

  Further, similarly to the above-described embodiment, the first core member 20 and the second core member 10 are heated to the curing temperature of the thermosetting resin by a heater (not shown) through a supply path (not shown). Then, a liquid thermosetting resin is filled between the processed surfaces 20a and 10a from the outside. In such a state, since the dividing surface of the first core member 20 and the second core member 10 is sealed by the sealing member 30, a thermosetting resin having a low viscosity is used as a processing surface (optical surface transfer surface). Even if it inject | pours between 20a and 10a, a leak does not arise. At this time, it is desirable that the material of the sealing member 30 has heat resistance that does not melt or deform even at the curing temperature of the thermosetting resin.

  After the thermosetting resin is heated and cured, when the second core member 10 is moved upward together with the rotary drive shaft RS, the optical element OE integrally formed so as to be in close contact with the sealing member 30 is exposed. . After that, as shown in FIG. 4C, the rotational drive shaft RS is rotated 180 degrees, the second core member 10 is opposed to the first core member 20, and then the rotational drive shaft RS is lowered. The third core member 40 is brought into close contact with the first core member 20. As a result, a new sealing member 30 can be molded. During the molding, the previous sealing member 30 and the optical element OE can be released as a single unit. In the released state, the optical element OE and the sealing member 30 are integrally formed. Thereafter, the optical element OE can be molded by repeating the same steps (see FIG. 4D).

  FIG. 5 is a schematic diagram illustrating a molding process of an optical element in a molding apparatus according to another embodiment. In the present embodiment, the holding member is omitted. In FIG. 5, the lower core member (second core member) 10 has a bag hole-like pot (also referred to as a recess) 13 in the middle of the optical surface transfer surface 11 arranged on the circumference having the same center. Forming. Further, the upper core member (first core member) 20 includes an optical surface transfer surface 21 disposed on the circumference having the same center, and a cylindrical through hole 25 formed corresponding to the pot 13. have. A piston member PM is slidably disposed in the through hole 25.

  Prior to molding, the thermosetting resin HR is stored in the pot 13. In this state, the core members 10 and 20 are combined with the sealing member 30 interposed therebetween, heated with a heater (not shown), and then the piston member PM is protruded toward the pot 13. As a result, the thermosetting resin HR in the pot 13 is pushed out radially, enters the cavity between the optical surface transfer surfaces 11 and 21, and is solidified to mold the optical element.

  FIG. 6 is a diagram illustrating a modification of the present embodiment. In the embodiment described above, the core members 10 and 20 to be clamped are single. However, as shown in FIG. 6, the plurality of core members 10 and 20 are positioned by the single holding members 70 and 60. By holding it, it may be adjusted at a time.

  FIG. 7 is a diagram illustrating an example of an air vent applicable to the above-described embodiment. In FIG. 7, the core member 10 has an air escape hole 14 formed outside the sealing member 30. On the other hand, the core member 20 forms a circumferential groove 26 so as to surround the sealing member 30 and the air escape hole 14, and an O-ring OR is disposed therein.

  Before molding, the core members 10 and 20 are combined with the sealing member 30 interposed therebetween, and a vacuum pump (not shown) is connected to the air escape hole 14 via the valve V, so that the cavity in the core members 10 and 20 is formed. Air is discharged from the CV. When the inside of the cavity CV is in a predetermined vacuum state, the valve V is closed, the suction from the air escape hole 14 is interrupted, and the thermosetting resin is supplied from a supply path (not shown), the air impeding the flow Is not present in the cavity CV, the thermosetting resin spreads to every corner of the cavity CV, and thereby a highly accurate optical element can be formed. In addition, since the thermosetting resin is sealed by the sealing member 30, it does not enter the air escape hole 14 and close it.

  The present invention has been described above with reference to the embodiments. However, the present invention should not be construed as being limited to the above-described embodiments, and can be modified or improved as appropriate. For example, the optical surface transfer surface of the core member may be arranged in a matrix without being arranged along the same circumference. Further, it is not necessary to arrange a resin supply path at the center of the optical surface transfer surface. This is because the thermosetting resin has a low viscosity at room temperature and thus has good flowability. Therefore, it is possible to provide a horizontal supply path between adjacent optical surface transfer surfaces, thereby obtaining an intermediate molded body M in which the outer periphery of adjacent optical elements OE is connected by a resin as shown in FIG. be able to. In such a case, the resin is injected from the outside through the injection port B.

  Furthermore, in addition to the case where the resin supply path extends from the outside toward the center of the same circumference, for example, when the mold is opened in the horizontal direction, a supply path is provided outside the circumference in the radial direction. Alternatively, an entirely flat supply path may be provided so that resin is supplied into the molding cavities from below in the direction of gravity or connected to the outer periphery of each molding cavity. In the case of a supply path with a small cross-sectional area extending from the outside, the molding pressure is transmitted from the supply path to the molding cavity of the optical surface transfer surface, so the residual stress due to shrinkage becomes uneven during curing when the viscosity increases. Therefore, optical inhomogeneities such as birefringence may occur in the molded product. Therefore, instead of providing a small cross-sectional area supply path, by connecting the molding cavity to a flat plate-shaped supply path, the resin is cured in a state where molding pressure is evenly applied from the outer periphery of the optical surface transfer surface, As a result, a high-quality molded product with less internal stress and distortion can be obtained.

It is a perspective view showing the core member concerning this embodiment held in jig J. It is a perspective view of an X, Y, Z, θ axis super-precision lathe for processing a core member according to the present embodiment. It is the schematic which shows the process of shape | molding an optical element with the shaping | molding apparatus containing the core member concerning this Embodiment. It is the schematic which shows the formation process of the optical element in the shaping | molding apparatus concerning another embodiment. It is the schematic which shows the formation process of the optical element in the shaping | molding apparatus concerning another embodiment. It is a figure which shows the modification of this Embodiment. It is a figure which shows the example of the air vent applicable to embodiment mentioned above. It is a figure which shows an example of an intermediate molded object. It is a perspective view shown in the state where a core member was held by jig J 'concerning a modification. It is a perspective view shown in the state where a core member was held by jig J 'concerning a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Core member 10a Processing surface 11 Optical surface transfer surface 13 Pot 14 Air escape hole 20 Core member 20a Processing surface 21, 21 'Optical surface transfer surface 22 Supply path 23 Step part 24 Horizontal supply path 25 Through hole 26 Circumferential groove 30 Sealing member 40 Core member 40a Work surface 50 Heater 60 Holding member 70 Holding member 105 Z-axis stage 106 X-axis stage 107 Y-axis stage 109 Rotation support 109a Chuck 110 Surface plate 113 Diamond tool A Space AX Axis line CB Counter balance CV Cavity HR Thermosetting Resin J, J 'Jig J1, J1', J2 Opening M Resin molding N Nozzle OE Optical element OR O-ring PM Piston member RS Rotation drive shaft RX Rotation axis

Claims (24)

A mold having a plurality of first optical surface transfer surfaces, which is aligned with a counter mold having a plurality of second optical surface transfer surfaces arranged to face each first optical surface transfer surface. In a mold for molding an optical element by supplying resin to a cavity formed between both molds,
At least the surface with which the resin supplied to the cavity comes into contact is formed integrally.   The mold according to claim 1, wherein the resin is an energy curable resin.   The mold according to claim 2, wherein the energy curable resin has a viscosity before curing of 100 (poise) or less.   4. The gold according to claim 1, wherein the center of the first optical surface transfer surface is disposed on a first circumference centered at one point on the mold surface. 5. Type.   At least two centers of the first optical surface transfer surface are arranged on a first circumference centered on one point of the mold surface, and are further on the same surface as the first circumference. 4. At least two of the first circumference and the second circumference having the same center and different in radius from the first circumference are arranged. The mold as described in.   The supply path extending from the outside toward the center of the circumference is provided, and the pressurized resin is supplied to the cavity through the supply path. The mold according to 4 or 5.   A supply path extending from the outside is provided outside the circumference in the radial direction, and pressurized resin is supplied to the cavity through the supply path. Item 6. The mold according to Item 4 or 5.   The mold includes a first core member having the first optical surface transfer surface, and a first holding member for holding the first core member, and the first core member includes: The second core member having the second optical surface transfer surface provided in the counter mold is in surface contact with the second holding member, and the first holding member is provided in the second mold provided in the counter mold. The mold according to any one of claims 1 to 7, wherein the mold is in surface contact with the second holding member that holds the core member.   The mold includes a first core member having the first optical surface transfer surface, and a first holding member for holding the first core member, and the first core member includes: The second core member having the second optical surface transfer surface provided in the counter mold is in surface contact with the second core member, and the first holding member is provided in the second mold provided in the counter mold. The die according to any one of claims 1 to 7, wherein the second holding member that holds the core member is not in surface contact. A first core member having a plurality of first optical surface transfer surfaces; and a second core member having a plurality of second optical surface transfer surfaces disposed to face each first optical surface transfer surface; And formed in the first core member or the second core member in a cavity formed between the two core members in a state where the first core member and the second core member are combined. A molding apparatus for molding an optical element by supplying a resin through a supply path,
In at least one of the core members, a surface with which the resin supplied to the cavity contacts is integrally formed.   The molding apparatus according to claim 10, wherein the resin is an energy curable resin.   The molding apparatus according to claim 11, wherein the energy curable resin has a viscosity before curing of 100 (poise) or less.   The center of the first optical surface transfer surface is disposed on a first circumference centered on one point on the surface of the first core member. The molding apparatus described in 1.   At least two centers of the first optical surface transfer surface are arranged on a first circumference centered on one point on the surface of the first core member, and the same surface as the first circumference is further provided. 11. At least two of the first circumference and the second circumference having the same center as the first circumference and having a radius different from the first circumference are arranged. 12. The molding apparatus according to any one of 12 above.   The first core member is provided with a supply path extending from the outside toward the center of the circumference, and the pressurized resin is supplied to the cavity through the supply path. The molding apparatus according to claim 13 or 14, wherein   The first core member is provided with a supply path extending from the outside on the outer side in the radial direction of the circumference so that the pressurized resin is supplied to the cavity through the supply path. The molding apparatus according to claim 13 or 14, wherein the molding apparatus is formed.   A through hole extending toward the center of the circumference is formed in the first core member, and a recess is formed in the second core member so as to face the through hole. In a state in which the core member and the second core member are combined, liquid resin is stored in the recess, and the resin in the recess is pushed out by a piston member that slides with respect to the through hole. The molding apparatus according to claim 13 or 14, wherein the pressurized resin is supplied to the cavity through a supply path.   A first holding member that holds the first core member; and a second holding member that holds the second core member. The first core member is connected to the second core member. The molding apparatus according to claim 10, wherein the molding apparatus is in surface contact with the first holding member and is in surface contact with the second holding member.   A first holding member that holds the first core member; and a second holding member that holds the second core member. The first core member is connected to the second core member. 18. The molding apparatus according to claim 10, wherein the first holding member is not in surface contact with the second holding member, although in surface contact with the second holding member.   The molding apparatus according to claim 10, wherein a sealing member is disposed between the first core member and the second core member.   21. The molding apparatus according to claim 20, wherein the sealing member has a ring shape surrounding a plurality of the first optical surface transfer surfaces and the second optical surface transfer surfaces.   Before aligning with the second core member, align the first core member with the third core member and supplying resin between the first core member and the third core member. The molding apparatus according to claim 20 or 21, wherein the sealing member is formed on the first core member.   An optical element having an optical surface molded from the optical surface transfer surface in a state molded by the molding apparatus according to any one of claims 10 to 22, and an optical element adjacent thereto are connected by a resin material. An intermediate molded body characterized by being made.   An optical element manufactured by cutting the intermediate molded body according to claim 23.