WO2015072508A1

WO2015072508A1 - Method for producing optical element, and optical element

Info

Publication number: WO2015072508A1
Application number: PCT/JP2014/080054
Authority: WO
Inventors: 勝己古田
Original assignee: コニカミノルタ株式会社
Priority date: 2013-11-14
Filing date: 2014-11-13
Publication date: 2015-05-21
Also published as: CN105745056B; JP6380913B2; JPWO2015072508A1; CN105745056A

Abstract

Provided are: a method for producing an optical element, which is capable of mass-producing uniform optical elements with consideration for the characteristics of an energy-curable resin; and an optical element. This method for producing an optical element comprises steps for: supplying an energy-curable resin between a first mold and a second mold; curing the energy-curable resin by supplying an energy in a first amount (E1) as an energy integral quantity and then supplying an energy in a second amount (E2) that is larger than the first amount (E1); and taking out a resin component that is cured by the curing step. The curing step is divided into a first curing step wherein at least the energy in the first amount (E1) is supplied and a second curing step wherein the energy in the second amount (E2) is supplied.

Description

Optical element manufacturing method and optical element

The present invention relates to an optical element manufacturing method and an optical element suitable for mass production of optical elements.

Generally, an optical element used for a chip part for medical examination, an optical pickup device, an imaging device or the like is required to have high accuracy, but is required to further reduce cost. In recent years, energy curable resins such as photocurable resins and thermosetting resins have attracted attention in response to such demands. Since the energy curable resin has a property of being cured in a short time by applying energy, it is expected that the optical element can be mass-produced at low cost by using this energy curable resin. Patent Document 1 discloses a technique for manufacturing an optical element using a photocurable resin. In addition, Patent Document 2 relates to a method for manufacturing an optical element of an energy curable resin, in which a plurality of molding steps are sequentially performed at predetermined rotation positions of a support base while rotating the support base at a predetermined time interval. A method for manufacturing a featured optical element is disclosed.

Patent Document 3 discloses a manufacturing method for stabilizing the shape of a surface by first weakening and then strengthening the energy for curing the photo-curing resin with respect to the method for producing the energy curable resin.

JP 2011-242478 A JP 2007-147679 A Japanese Patent Publication No. 7-82121

By the way, the energy curable resin has a characteristic that the shrinkage rate is relatively large as compared with the thermoplastic resin generally used in the conventional optical element. In particular, in the case of an ultraviolet curable resin, the shrinkage rate is as high as about 3% to 10%, and curing proceeds from the irradiated surface side. Therefore, in a relatively thick product, sink marks or the like occur as the cured layer progresses inside. There is a risk that the shape of the mold cannot be transferred with high accuracy. Further, even when the external shape is ensured, stress and strain remain inside the optical element, and there is a possibility that the optical characteristics may be deteriorated due to changes in humidity and temperature when mounted on an actual device. On the other hand, if the irradiation intensity of ultraviolet rays or the like is lowered, defects such as sink marks can be suppressed to some extent, but there is a problem that the time required for curing increases and the molding time becomes longer. In Patent Document 3, the shape of the surface is stabilized by weakening the energy for curing the photo-curing resin at first and then strengthening it, but it cannot be solved that the molding time becomes long.

On the other hand, according to the technique of Patent Document 1, the light amount distribution is gradually reduced from the center part to the peripheral part of the optical element. However, if attention is paid to any one place, the internal progress of the cured layer still occurs. There is still a problem that sink marks are likely to occur. Moreover, since residual stress and distortion are likely to occur, there is a concern about deterioration of optical characteristics when mounted on an actual machine.

An object of the present invention has been made in view of the above-described problems, and an optical element manufacturing method and an optical element capable of mass-producing a homogeneous optical element with a short molding time while considering the characteristics of an energy curable resin. It is to provide an element.

In order to achieve at least one of the above-described objects, a method for manufacturing an optical element reflecting one aspect of the present invention includes:
An optical element manufacturing method for forming an optical element by supplying an energy curable resin between a first mold and a second mold,
Clamping the first mold and the second mold;
Supplying energy from an energy supply source to the energy curable resin between the first mold and the second mold and curing the resin;
Opening the first mold and the second mold; and
A step of taking out the molded optical element from between the first mold and the second mold,
In the step of supplying energy to the energy curable resin and curing it, a first step of supplying energy of a first amount E1 as an energy integral amount obtained by multiplying a supply time and a supply energy intensity, and after the first step And a second step of supplying a second amount E2 of energy larger than the first amount E1 as an energy integral amount obtained by multiplying the supply time and the supply energy intensity (provided that the supply energy of the first step) When the intensity is the same as the supply energy intensity of the second step, the second amount E2 per unit time is larger than the first amount E1 per unit time).

According to the present invention, it is possible to provide an optical element manufacturing method and an optical element capable of mass-producing homogeneous optical elements in consideration of the characteristics of the energy curable resin.

It is a perspective view which shows the manufacturing apparatus of the optical element in this embodiment. It is a figure which expand | deploys and shows the manufacturing apparatus of an optical element in the circumferential direction. It is a perspective view which shows the periphery of lower mold | type MD2 in the 2nd process part B. FIG. It is a graph which shows the hardening light integral amount (irradiation time x irradiation intensity) which photocurable resin PL receives by hatching. It is a graph which shows the hardening light integration amount (irradiation time x irradiation intensity) which photocurable resin PL receives by pulse-shaped irradiation. It is a figure which shows the modification of lower metal mold | die MD2.

As the “optical element” manufactured in the present embodiment, there are a mirror part for a projector, an optical element for illumination, and the like in addition to a chip part for medical examination and an optical element for imaging. The optical element is not limited to a lens, but when it is a lens, for example, it may be a flange-integrated type or a flange-separated type. Further, an integrated lens having a plurality of optical axes may be used. Various forms are conceivable as the lens shape, and include, for example, a convex lens, a concave lens, a thin lens, a decentered lens, a Fresnel lens, and a diffractive lens.

The first mold and the second mold may include not only a transfer surface for molding a single optical element but also a transfer surface for molding a plurality of optical elements. On the surface such as the transfer surface of the mold, a structure such as fine irregularities, a water-repellent film, or the like may be formed in order to improve the releasability of the optical element. In addition, it is preferable to provide a positioning portion for aligning the first mold and the second mold because positioning can be performed with high accuracy. Such a positioning portion may be provided on a holding body that holds the first mold and the second mold, or may be provided on the first mold and the second mold itself.

Examples of the “energy curable resin” that can be used in the present embodiment include a photocurable resin and a mature curable resin. In the case of a photocurable resin, the resin is cured by supplying light of a predetermined wavelength as energy, and in the case of a thermosetting resin, the resin is cured by supplying heat as energy.

In the case where a photocurable resin is used as the energy curable resin, it is preferable that at least one of the first mold and the second mold is formed of a light transmissive material. If the mold is a light transmissive material, light can be supplied to the photocurable resin through the mold, so that the efficiency of curing is improved. In the case of using a photocurable resin, for example, the mold material is, for example, PET (polyethylene terephthalate) resin, PMMA (polymethyl methacrylate) resin, COC (cycloolefin copolymer) resin, COP (cycloolefin polymer) resin, PC (polycarbonate) resin, PE A thermoplastic resin such as a (polyethylene) resin, a PP (polypropylene) resin, or a fluororesin, a photocurable resin such as an epoxy resin, an acrylic resin, or a vinyl resin, or glass can be used. When glass is used as the shape material, the shape material can be produced by glass molding, droplet molding, reheating molding, or the like. As the mold material, it is preferable to use a material that easily transmits a wavelength for curing a photocurable resin used as a material of the optical element.

When a thermosetting resin is used as the energy curable resin, an electric heater or a halogen heater can be used as an energy supply source. In this case, the first mold and the second mold are preferably made of metal or glass having good heat resistance. Further, when a glass mold and a halogen heater are used in combination, it is desirable that an infrared absorbing material is formed on the mold transfer surface (optical surface transfer surface) because heat generation is effectively generated.

When supplying the energy curable resin with the first mold and the second mold open, the energy curable resin may be supplied to any mold, but when using a dispenser or the like, the mold is located below the gravitational direction. It is desirable to supply. The mold to which the energy curable resin is supplied may be rotated, and the energy curable resin may be spread on the transfer surface of the mold by centrifugal force.

Further, for example, the energy curable resin can be supplied after the first mold and the second mold are clamped as in injection molding.

On the other hand, energy can be supplied to the energy curable resin while clamping the first mold and the second mold. It is preferable to supply such energy from both the first mold and the second mold.

In order to easily release the molded optical element from the mold, a structure for projecting the molded optical element with a core or a pin or a structure for applying ultrasonic vibration to the mold may be provided as a mold release assisting structure. In order to take out the molded optical element from the mold, various forms such as an air chuck, a robot chuck, and air blowing can be used.

In the mold clamping process, various pre-molding processes for pre-molding may be performed. In the pre-molding process, for example, a camera is used to monitor whether there is an abnormality in the mold, and if there is an abnormality, a process for stopping the production of the optical element by issuing an alarm, or a process for cleaning the mold used for molding In addition, there is a step of performing a process (silicon coating) for urging the mold to release the optical element.

Further, in the step of taking out the molded optical element, a post-molding step for performing post-processing after molding may be performed. Examples of the post-molding process include a post-cure for heating and the like, and a process for annealing in order to completely cure the molded optical element. In addition, you may perform these post-molding processes in another place with respect to the optical element taken out from the type | mold.

When continuous molding is performed along a closed locus using a plurality of molds, the preceding first mold and the second mold and the following first mold and the second mold are arranged at equal intervals. It is desirable to move at a constant speed. However, the interval between the molds may be locally changed for timing adjustment.

Furthermore, the “closed trajectory” refers to the movement trajectories of the first mold and the second mold that go in order to the processing section that faces a plurality of processes in order, and go back to the first processing section, regardless of the shape. It means a closed loop. However, a branch may be provided in the movement trajectory in order to eliminate abnormal molds, or another route that is coupled to a closed trajectory may be inserted in order to insert a mold without abnormality that has been waiting.

In the present embodiment, the “step of supplying energy to the energy curable resin for curing” includes a first step and a second step. In the first step, energy of the first amount E1 is supplied as an energy integration amount obtained by multiplying the supply time and the supply energy intensity. In the second step, after the first step, energy of a second amount E2 larger than the first amount E1 is supplied as an energy integral amount obtained by multiplying the supply time and the supply energy intensity. The average supply energy intensity per unit time in the first step is preferably 1/20 or more and 1/2 or less of the average supply energy intensity per unit time in the second step. If it is less than 1/20, the energy intensity is too small in the first step, so it is difficult for sink marks to occur on the surface, but it takes time to cure in the second step, and the second step becomes the bottleneck of cycle time. End up. If it is greater than 1/2, there is no difference in strength between the first step and the second step, so the energy strength in the first step is large and sink marks are likely to occur. In addition, after the second step, a third step of supplying energy of a third amount E3 larger than the second amount E2 as an energy integration amount obtained by multiplying the supply time and the supply energy intensity may be provided.

It is preferable that the intensity of energy per unit time supplied during the first step from the energy supply source is constant, and the intensity of energy per unit time supplied during the second step is constant. Thereby, the curing reaction rate of the energy curable resin can be made constant. “Constant” includes variations within ± 5% of the average value of energy intensity.

It is preferable that the energy intensity per unit time supplied during the first step from the energy supply source gradually increases, and the energy intensity per unit time supplied during the second step increases gradually. Thereby, the curing reaction rate of the energy curable resin can be gradually increased.

The intensity of energy per unit time supplied from the energy supply source is constant, and the accumulated time during which energy is supplied during the first step is greater than the accumulated time during which energy is supplied during the second step. Short is preferable. Thereby, after the first step, the energy of the second amount E2 larger than the first amount E1 can be supplied as an energy integration amount obtained by multiplying the supply time and the supply energy intensity.

Embodiments according to the present invention will be described below with reference to the drawings. However, although various technically preferable limitations for carrying out the present invention are given to the embodiments described below, the scope of the invention is not limited to the following embodiments and illustrated examples.

FIG. 1 is a perspective view showing an optical element manufacturing apparatus according to this embodiment. FIG. 2 is a diagram showing an essential part of the optical element manufacturing apparatus shown in FIG. 1 developed in the circumferential direction. In the manufacturing apparatus, a first disk DC1 that is a first holding body and a second disk DC2 that is a second holding body are arranged coaxially with a gap therebetween. The center of the first disk DC1 and the second disk DC2 is connected to the rotation shaft SFT through a spline or the like so as not to rotate relative to the rotation shaft SFT. The first disk DC1 and the second disk DC2 are driven to rotate synchronously.

A plurality of circular openings DC1a (eight in this case) are formed in the first disk DC1, and a cylindrical upper mold (first mold) MD1 is fixed in the circular opening DC1a. The upper mold MD1 has a transfer surface MD1a on the lower surface. The upper mold MD1 is made of light transmissive plastic or transparent glass. Here, the upper mold MD1 manufactured by injection molding of light-transmitting plastic was used.

In the second disk DC2, a plurality (eight in this case) of circular openings DC2a are formed so as to be arranged in the same manner as the circular opening DC1a. 2 type) MD2 is arranged so as to be movable in the axial direction of the rotation axis SFT. The lower mold MD2 has a transfer surface MD2a on the upper surface. Here, the lower mold MD2 manufactured by injection molding of light-transmitting plastic was used.

In addition, the upper mold MD1 and the lower mold MD2 can be formed by injection molding of a light-transmitting resin, whereby the upper mold MD1 and the lower mold MD2 having the same shape can be produced in large quantities with high accuracy.

Particularly, when the material of the upper mold MD1 and the lower mold MD2 is glass, the durability is excellent. In addition, by manufacturing a mold using glass, a mold having the same shape can be produced with high accuracy. Furthermore, it is preferable that the upper mold MD1 and the lower mold MD2 are formed by transferring glass to a mold because the upper mold MD1 and the lower mold MD2 having the same shape can be produced in large quantities with high accuracy.

The shielding part SH is formed so as to cover a part of the first disk DC1 and the second disk DC2 in the circumferential direction. On the top surface of the shielding part SH, a plurality of light sources OPS (two actually shown in FIG. 2 but three actually) are provided as energy supply sources for curing the energy curable resin that is the material of the optical element. It arrange | positions along the circumferential direction of 1 disk DC1 and 2nd disk DC2, and has faced the light emission surface below. The light source OPS is preferably provided directly above the center locus of the upper mold MD1 that rotates.

On the other hand, as shown in FIG. 2, a plurality of light sources OPS (two actually shown in FIG. 2 but three actually) are arranged below the second disk DC2 so as to face the shielding part SH. Yes. The upper and lower light sources OPS are opposed to each other, the emission intensity of the first light source OPS is the smallest, the emission intensity of the second light source OPS is the next smallest, and the emission intensity of the third light source OPS is the highest. Yes. The light source OPS is preferably an LED that can irradiate ultraviolet rays having a peak wavelength of 365 nm. Hereinafter, the term “curing light” will be used to represent “ultraviolet rays” and the like.

The light source OPS is controlled by the control circuit CONT, and the irradiation time of the curing light and the angular position of the first disk DC1 and the second disk DC2 (positional relationship between the upper mold MD1 and the lower mold MD2 to be irradiated) and It is preferable to adjust at least one of the intensity of the curing light. However, here, the irradiation intensities of the three light sources OPS are individually made different, and the control circuit CONT controls only on / off according to the rotation of the first disk DC1 and the second disk DC2.

Below the second disk DC2, a pair of ring-shaped cam plates CP constituting the mold drive unit are fixedly arranged. As shown in FIG. 2, the cam surface CPa of the cam plate CP has a low portion CPb, an ascending slope CPc, a high portion CPd, and a descending slope CPe according to the position in the circumferential direction.

FIG. 3 is a perspective view showing the periphery of the lower mold MD2 in the second processing unit B. FIG. On the lower surface of the lower mold MD2, there are formed a wheel-shaped follower FW that rolls on the cam surface CPa of the parallel cam plate CP and a support portion SP that rotatably supports the follower FW. A plurality of light sources OPS (only one is shown in FIG. 3) are arranged between the pair of cam plates CP. The light emitted from the light source OPS is incident from the lower surface between the support portions SP of the light-transmissive lower mold MD2, and is emitted from the upper transfer surface MD2a.

As shown in FIG. 2, the first processing unit A, the second processing unit B, the third processing unit C, and the fourth processing unit D according to the rotational positions of the first disk DC1 and the second disk DC2. It has become. In the 1st process part A, dispenser DSP which can discharge a suitable quantity of photocurable resin is arrange | positioned. In the second processing unit B, light sources OPS are arranged in the circumferential direction. In the fourth processing unit D, an arm type robot RB for taking out the molded optical element OE is arranged.

The operation of the manufacturing apparatus and the optical element manufacturing process in the present embodiment will be described here with a focus on a pair of upper mold MD1 and lower mold MD2. First, when the actuator AC is driven by power supply from a power source (not shown) and the rotation shaft SFT is rotated, the first disk DC1 and the second disk DC2 rotate in synchronization. Here, in the former stage in the first processing section A, the follower FW of the lower mold MD2 is in the lower portion CPb on the cam surface CPa of the cam plate CP, and therefore the upper mold MD1 and the lower mold MD2 are in an open state. Thus, the photocurable resin PL can be dropped on the transfer surface MD2a of the lower mold MD2 via the dispenser DSP.

Next, the upper mold MD1 and the lower mold MD2 supplied with the photocurable resin PL therebetween move by the synchronous rotation of the first disk DC1 and the second disk DC2. Here, since the follower FW of the lower mold MD2 rolls on the climbing slope CPc on the cam surface CPa of the cam plate CP, the lower mold MD2 gradually approaches the upper mold MD1. When the follower FW reaches the high portion CPd on the cam surface CPa of the cam plate CP, the two are brought into close contact with each other and are clamped (the latter stage in the first processing portion A). Further, while the follower FW rolls on the high portion CPd, the mold clamping state of the upper mold MD1 and the lower mold MD2 is maintained.

Thereafter, the upper mold MD1 and the lower mold MD2 move to the second processing unit B by the synchronous rotation of the first disk DC1 and the second disk DC2 while maintaining the mold clamping state. In the second processing unit B, in the present embodiment, the second processing unit B includes a first process, a second process, and a third process.

FIG. 4 is a graph showing the integrated amount of curing light (irradiation time × irradiation intensity) received by the photocurable resin PL by hatching, the horizontal axis is the irradiation time (seconds), and the vertical axis is the irradiation intensity per unit area. (MW / cm ² ). Note that the curing light integral amount necessary for curing the entire photocurable resin PL is, for example, a curing light integral amount 4500 (mJ / cm ² ) obtained by irradiation for 25 seconds at an intensity of 180 (mW / cm ² ). And

First, in the first step, the upper mold MD1 and the lower mold MD2 pass between the upper and lower light sources OPS closest to the first processing unit A. At this time, the curing light is irradiated to the photocurable resin PL through the upper mold MD1 and the lower mold MD2 having light transmittance. At this time, the curing light integration amount E1 supplied to the photocurable resin PL. Is 144 (mJ / cm ² ) because irradiation is performed for 8 seconds at a constant intensity of 18 (mW / cm ² ). Thereby, only the surface of the photocurable resin PL is cured in the first step.

Next, in the second step, the upper mold MD1 and the lower mold MD2 pass between the first upper and lower light sources OPS from the first processing unit A. At this time, the curing light is irradiated to the photocurable resin PL through the upper mold MD1 and the lower mold MD2 having light transmittance. At this time, the curing light integration amount E2 supplied to the photocurable resin PL. Is 1440 (mJ / cm ² ) because irradiation is performed at a constant intensity of 180 (mW / cm ² ) for 8 seconds. Thereby, it hardens | cures from the surface of photocurable resin PL to the back | inner position in a 2nd process.

Finally, in the third step, the upper mold MD1 and the lower mold MD2 pass between the upper and lower light sources OPS farthest from the first processing unit A. At this time, the curing light is irradiated to the photocurable resin PL through the upper mold MD1 and the lower mold MD2 having light transmittance. At this time, the curing light integration amount E3 supplied to the photocurable resin PL. Is 2916 (mJ / cm ² ) because 9 is irradiated at a constant intensity of 324 (mW / cm ² ). Since the total amount of cured light received by the photocurable resin PL from all the OPSs is E1 + E2 + E3 = 144 + 1440 + 2916 = 4500 (mJ / cm ² ), the center of the photocurable resin PL is obtained through the third step. It will be completely cured to the part. As is apparent from the figure, the average supply energy intensity per unit time in the first process is lower than the average supply energy intensity per unit time in the second process, and the average supply energy intensity per unit time in the second process. Is lower than the average supply energy intensity per unit time in the third step.

According to the present embodiment, in the initial stage (first step) of supplying curing light to the photocurable resin PL, the curing reaction rate near the surface is slowed down by suppressing the amount of integration of the curing light to be supplied. The flow inside the resin can be secured while ensuring the transfer accuracy of the surface. If a relatively large curing light integration amount is applied from the initial stage of supplying curing light to the photocurable resin PL, the curing reaction speed from the surface is increased, and the flow inside the resin is hindered, thus causing problems such as sink marks. It is. Also, in the initial stage (first step) of supplying curing light to the photocurable resin PL, by suppressing the amount of curing light to be supplied to a small level, the residual stress and strain inside the resin can be reduced by gradually curing from the surface. It is possible to reduce the optical performance due to environmental changes and deterioration over time. Such an effect is more effectively exhibited by gradually increasing the curing light integration amount from the first step to the second step and the third step. Also, in the latter stage (third step) in which the curing light is supplied to the photocurable resin PL, the curing proceeds relatively deeply into the resin, so that even if the curing light integration amount is increased, the influence of sink marks, residual stress, etc. The tact time of the product can be effectively reduced by increasing the curing reaction rate. As the thickness of the product, the maximum thickness is preferably 300 μm or more and 10 mm or less. If it is 300 μm or less, it will be too thin and difficult to mold, and sink marks will be difficult. On the other hand, if the thickness is 10 mm or more, the product is too thick and the product may be incompletely cured, or it may take too long to cure.

1 and 2, the upper mold MD1 and the lower mold MD2 that have passed through the second processing section B move to the third processing section C by the synchronous rotation of the first disk DC1 and the second disk DC2. Here, since the follower FW of the lower mold MD2 rolls on the downward slope Cpe on the cam surface CPa of the cam plate CP, the lower mold MD2 is gradually separated from the upper mold MD1 to open the mold. Is done.

After the follower FW has finished rolling on the downward slope Cpe, the lower part CPb rolls again, so that the lower mold MD2 is maintained open with respect to the upper mold MD1, and the following fourth In the processing section D, the arm of the robot RB can be expanded and contracted to take out the optical element OE formed by the transfer surfaces MD1a and MD2a and transport it to another process. The operation of the manufacturing apparatus and the optical element manufacturing process have been described above focusing on the pair of the upper mold MD1 and the lower mold MD2. The other upper mold MD1 and lower mold MD2 are also sequentially manufactured in the same manner at different timings. Therefore, high-precision optical elements OE can be produced in large quantities.

According to the present embodiment, the curing process, which takes a relatively long time in the manufacturing process, is divided into a plurality of processes, and the energy for curing is increased in the subsequent processes in each process. Eliminate bottlenecks and improve the quality of resin molded products, enabling mass production of high-precision resin products.

According to the present embodiment, according to the rotation of the holding bodies DC1 and DC2, a plurality of first molds MD1 and second molds MD2 provided along a closed locus (circle) respectively along the locus. Since the dispenser DSP as a supply device for supplying the photocurable resin can be used in common for the first mold MD1 and the second mold MD2 that move, the space can be saved and the equipment cost can be reduced. it can. Further, since the first mold MD1 and the second mold MD2 move along the closed locus with respect to the second processing unit B, the moving first mold MD1 and second mold MD2 Since light can be supplied from the light source OPS as a common energy supply source to the photocurable resin PL supplied during the manufacturing process, the manufacturing conditions are the same, and manufacturing variations can be suppressed. Furthermore, since the first mold MD1 and the second mold MD2 move along the closed locus with respect to the fourth processing unit C, the first mold MD1 and the second mold MD2 that move are moved. Since the robot RB as a device for taking out the manufactured optical element can be used in common, the space can be saved and the equipment cost can be reduced. Thereby, it is possible to produce a large amount of homogeneous optical elements OE at low cost.

According to the present embodiment, in the first processing unit A, the first mold MD1 and the second mold MD2 can gradually approach with movement along the closed locus. Accordingly, by gradually bringing the first mold MD1 and the second mold MD2 closer to each other, entrainment of bubbles and the like can be suppressed, and a highly accurate optical element OE can be manufactured. Further, the relative movement along the locus during mold clamping does not obstruct the movement of the subsequent first mold MD1 and second mold MD2.

According to the present embodiment, the second processing unit B is provided with a light source OPS as an energy supply source. By the relative movement of the first mold MD1 and the second mold MD2 with respect to the light source OPS, energy is supplied uniformly to the photocurable resin between the first mold MD1 and the second mold MD2. be able to. In particular, when light is emitted from the light source OPS, shadows are easily generated depending on the location. Therefore, it is desirable to move the first mold MD1 and the second mold MD2 relative to the light source OPS for stable production. .

According to the present embodiment, in the third processing unit C, the first mold MD1 and the second mold MD2 are gradually separated along with the movement along the closed locus. By gradually separating the first mold MD1 and the second mold MD2, for example, even when a fine diffractive structure is formed on the manufactured optical element OE, the mold is not damaged. Opening is possible. Further, when the mold is opened, the first mold MD1 and the second mold MD2 move along the trajectory, so that the subsequent movement of the first mold MD1 and the second mold MD2 is not disturbed.

According to the present embodiment, the second mold MD2 is moved closer to the first mold MD1 in response to entering the first processing unit A, and enters the third processing unit C. In response to this, it has a ring-shaped cam plate CP and a follower FW as a mold drive unit that is separated from the first mold MD1. Thereby, the approach and separation of the first mold MD1 and the second mold MD2 can be controlled at an optimal timing.

As a modification of the present embodiment, as indicated by a dotted line in FIG. 4, the irradiation intensity of the curing light is gradually increased in the first process, the second process, and the third process in the second processing unit B. May be. Thereby, the curing reaction rate of the photocurable resin PL can be gradually increased. It should be noted that the total curing light integration amount is preferably the same as in the above-described embodiment. Also in this case, the average supply energy intensity per unit time in the first process is lower than the average supply energy intensity per unit time in the second process, and the average supply energy intensity per unit time in the second process is the third process. Lower than the average supply energy intensity per unit time.

Furthermore, as another modified example, as shown in FIG. 5, curing light is irradiated in a pulse shape indicated by hatching in the first process, the second process, and the third process in the second processing unit B. Also good. Here, for example, the irradiation intensity of the three light sources OPS is fixed to 500 (mW / cm ² ), and a shutter that can be driven independently is provided so that the upper mold MD1 and the lower mold MD2 are positioned at predetermined positions. When it comes to, curing light can be irradiated in pulses by opening the shutter for 0.2 seconds. The energy intensity may be changed for each pulse irradiation.

In the example of FIG. 5, one irradiation is performed in the first step, two irradiations are intermittently performed in the second step, and five irradiations are continuously performed in the third step. The average supply energy intensity per unit time in the first process is lower than the average supply energy intensity per unit time in the second process, and the average supply energy intensity per unit time in the second process is the unit in the third process. Lower than average supply energy intensity per hour. Further, the curing light integration amount is preferably the same as that in the above-described embodiment.

FIG. 6 is a cross-sectional view showing a modified example of the lower mold MD2 moved to the second processing section B. In this example, the lower mold MD2 made of a light-transmitting material has a reflecting mirror MR inside. In the second processing unit B, a light source OPS is fixedly disposed at a position adjacent to the side surface of the lower mold MD2 and facing the reflecting mirror MR so that the curing light can be irradiated to the side. Other configurations are the same as those of the above-described embodiment.

At the time of molding, when the lower mold MD2 moves to the second processing section B by the rotation of the second disk DC2, the curing light emitted from the light source OPS enters the reflecting mirror MR through the side surface of the lower mold MD2. Further, the light is further reflected toward the upper transfer surface MD2a. Thereby, the photocurable resin supplied to the transfer surface MD2a can be cured. According to this example, since the curing light is not incident from the lower surface of the lower mold MD2, the support portion SP can be provided at the center of the lower surface of the lower mold MD2.

The present invention is not limited to the embodiments described in the present specification, and includes other embodiments and modifications based on the embodiments and technical ideas described in the present specification. It is obvious to

A 1st processing part B 2nd processing part C 3rd processing part D 4th processing part AC Actuator CP Cam plate CPa Cam surface CPb Low part CPc Climbing slope CPd High part CPe Down slope CR Conveying part DC1 1st Disc DC1a Circular aperture DC2 Second disc DC2a Circular aperture SP Support portion DSP Dispenser FW Follower MD1 Upper mold MD1a Transfer surface MD1b Planar portion MD1c Tapered surface MD1d Cylindrical inner surface MD2 Lower mold MD2a Transfer surface MD2b Planar portion MD2c Tapered surface MD2d Cylinder Outer surface OE Optical element OPS Light source PL Photocurable resin RB Robot SFT Rotating shaft SH Shielding part

Claims

Supplying an energy curable resin between the first mold and the second mold;
After supplying energy of the first amount E1 as an energy integral amount obtained by multiplying the energy curable resin by the supply time and the supply energy intensity, the supply time and the supply energy intensity are multiplied after the first energy supply. A curing step of supplying a second amount E2 of energy larger than the first amount E1 as an energy integration amount;
A step of taking out the resin component cured in the curing step;
The curing step is divided into a first curing step for supplying at least the first amount E1 of energy and a second curing step for supplying the second amount of energy E2. Manufacturing method.
The method of manufacturing an optical element according to claim 1, wherein the first amount E1 is 1/20 or more and 1/2 or less of the second amount E2.
The intensity of energy per unit time supplied during the first step from the energy supply source is constant, and the intensity of energy per unit time supplied during the second step is constant. The method of manufacturing an optical element according to claim 1 or 2.
The energy intensity per unit time supplied during the first step from the energy supply source is gradually increased, and the energy intensity per unit time supplied during the second step is gradually increased. The method of manufacturing an optical element according to claim 1 or 2,
The intensity of energy per unit time supplied from the energy supply source is constant, and the accumulated time during which energy is supplied during the first step is the accumulated time during which energy is supplied during the second step. 3. The method of manufacturing an optical element according to claim 1, wherein the optical element is shorter.
The first mold and the second mold are provided so as to move along a closed locus, and a plurality of the first die and the second die are provided along the closed locus, respectively, and the preceding first mold and the second die After the second mold has undergone one of the processes, the subsequent first mold and the second mold have undergone the one process,
The optical system according to claim 1, wherein the first mold and the second mold supply energy along the closed locus by approaching the energy supply source. Device manufacturing method.
The energy curable resin is a photocurable resin, and the first mold and the second mold are light transmissive to light that cures the photocurable resin. The manufacturing method of the optical element in any one of.
9. The energy supply source according to claim 1, wherein the energy supply source adjusts at least one of an energy supply time and an energy intensity according to a positional relationship between the first mold and the second mold. The manufacturing method of the optical element in any one.
10. An optical element manufactured by the manufacturing method according to claim 1 having a maximum thickness of 200 μm or more and 10 mm or less.