WO2014122868A1

WO2014122868A1 - Optical member fabrication method, optical member, lens fabrication method, and lens

Info

Publication number: WO2014122868A1
Application number: PCT/JP2013/084569
Authority: WO
Inventors: 勝己古田
Original assignee: コニカミノルタ株式会社
Priority date: 2013-02-05
Filing date: 2013-12-25
Publication date: 2014-08-14
Also published as: JPWO2014122868A1; CN104969096B; CN104969096A; JP6198016B2

Abstract

Provided is a lens fabrication method whereby it is possible to inexpensively mass produce a high-precision lens and a lens which is fabricated thereby. By making two molds face one another in a state of rigid substrates being applied thereto, thus accurately adjusting a gap therebetween, then detaching the second rigid substrate, and thereafter peeling away the elastic second resin mold (SM2) while bending same starting at an end thereof from a lens array (LA), it is possible to easily peel the second resin mold (SM2) from the lens array (LA). Additionally, by detaching the first rigid substrate, then peeling away the elastic first resin mold (SM1) while bending same starting at an end thereof from the lens array (LA), it is possible to easily peel the first resin mold (SM1) from the lens array (LA).

Description

Optical member manufacturing method, optical member, lens manufacturing method, and lens

The present invention relates to a method for manufacturing an optical member, an optical member, a method for manufacturing a lens, and a lens, and in particular, a method for manufacturing an optical member capable of mass production at a low cost, a method for manufacturing a lens, and an optical member obtained thereby. , Relating to lenses.

In recent years, mobile terminals with thin imaging devices such as smartphones and tablet personal computers are rapidly spreading. However, an imaging device mounted on such a thin portable terminal is required to be further reduced in price as well as being thin and compact while having high resolution. Accordingly, there is a demand for lenses that can be used in imaging devices mounted on these thin portable terminals, and that can be mass-produced at lower cost while ensuring high quality.

Against this background, a large number of lenses, such as thousands, are used as a lens material by using an energy curable resin such as a UV curable resin that does not require heating equipment and is cured in a short time by irradiation with UV light. Thus, a shift to a manufacturing method for molding is being sought. As a method for manufacturing such a lens, an energy curable resin is dropped on a parallel plate such as a glass substrate, and the mold is pressed and cured in the mold to form a plurality of lenses at once. After that, a large number of lenses were manufactured by cutting into individual lenses (see Patent Document 1).

JP 2012-111131 A Japanese Patent Laid-Open No. 2002-187135

By the way, with the technique of Patent Document 1, the lens can be mass-produced at a low cost, but the axial thickness of the lens increases by the thickness of the glass substrate, which may hinder the compactness of the imaging device and the like. Further, the lens may be peeled off from the glass substrate after molding. As one measure for avoiding such a problem, it is conceivable to mold a large number of lenses in a lump using only an energy curable resin. However, when the substrate is not used, the resin and the mold are in full contact with each other. Therefore, when the number of lenses is increased, the contact area between the mold and the molded product is remarkably increased and the mold release resistance is increased. Mold defects are likely to occur. In particular, when an optical member provided with a fine concavo-convex structure such as a blazed shape or a stepped shape is produced, the fine concavo-convex structure of the mold or the optical member is liable to be damaged during mold release. If the mold release process is performed to prevent this, the process becomes troublesome, the manufacturing process increases, and it takes time to maintain the mold, making it difficult to manufacture the lens at a low cost.

On the other hand, it has also been proposed to mold an energy curable resin using a resin mold having good releasability. For example, Patent Document 2 proposes a method for manufacturing a lens sheet using a mold made of an additional silicon resin. More specifically, after applying a resin for lenses (ultraviolet curable resin or electron beam curable resin) to the base material, and overlaying the resin mold made of addition type silicon resin lined with a plastic plate, pressing with a roller, The resin is cured and the resin mold is released together with the plastic plate. In the method for manufacturing a lens sheet described in Patent Document 2, a plastic plate and a resin mold made of an additional silicon resin are bent together and released. This is expected to facilitate release from the lens sheet. However, if a substrate that facilitates bending is used, another problem is that the thickness of the resin to be molded tends to be non-uniform during pressing, making it difficult to control the thickness of the lens sheet with the required thickness. Occurs.

The present invention has been made in view of the problems of the prior art, and an optical member and a lens manufacturing method capable of mass-producing high-precision optical members and lenses at low cost, an optical member manufactured thereby, and The object is to provide a lens.

The method for producing an optical member according to claim 1 is a method for producing an optical member having at least a plurality of lenses arranged in a row.
A first mold obtained by adhering an elastic first resin mold having a first transfer surface for transferring a first optical surface of the plurality of lenses to a hard first substrate; A second mold obtained by bringing a second resin mold having elasticity with a second transfer surface for transferring the second optical surfaces of a plurality of lenses into close contact with a hard second substrate, energy A mold facing step in which a curable resin is interposed to face each other at a predetermined interval;
A resin curing step of forming a molded body by curing by applying energy to the energy curable resin interposed between the first mold and the second mold;
A mold release step of releasing the first mold and the second mold from the molded body to obtain the optical member,
In the mold release step, for at least one of the first mold and the second mold, after releasing the hard substrate from the resin mold having elasticity, the mold is released from the molded body while bending the resin mold. It is characterized by doing.

Energy curable resins generally have a low viscosity, so when performing molding using an elastic resin mold as a mold, there is little risk of deforming the transfer surface during clamping, and high-precision transfer molding can be performed. it can. In addition, since two hard substrates are used, the two resin molds can be accurately adjusted to each other using these substrates, and the thickness of the molded product can be controlled as intended. . Moreover, at the time of mold release, by peeling the hard substrate from at least one resin mold, the elastic resin mold can be peeled off from the molded product while being bent. By releasing the mold while bending the mold, the molded product and the resin mold are released linearly, so that the release resistance can be reduced. Therefore, even when molding an optical member in which a plurality of lenses are arranged and the mold release resistance tends to be high due to the uneven shape, the mold can be easily released without degrading the accuracy of the lens.

According to a second aspect of the present invention, there is provided the optical member molding method according to the first aspect of the invention, wherein the releasing step is performed after the substrate is peeled from the resin mold for one of the first mold and the second mold. The first mold release step for releasing the resin mold from the molded body while bending the resin mold from which the substrate has been peeled, and the other of the first mold and the second mold after the first mold release process. And a second release step of releasing from the molded body while bending the resin mold from which the substrate has been peeled off after being peeled from the resin mold.

Thereby, even an optical member having a complicated optical surface such as a curved surface or a blazed shape on both sides can be easily released.

According to a third aspect of the present invention, there is provided the optical member manufacturing method according to the second aspect of the invention, wherein the mold release step is the molded product obtained by releasing the first resin mold after the first mold release step. The method further includes a step of attaching a removable sheet to the surface.

According to the present invention, after the first mold release step, by attaching a removable sheet to the surface of the molded product from which the first resin mold has been released, in the second mold release step, the molding is performed. It is possible to prevent the optical surface of the object from being damaged or the lens from being dissipated by inadvertent separation during mold release. Further, even after the second mold release step is completed, the optical member and the sheet can be handled as a unit, and the workability and transportability are excellent.

According to a fourth aspect of the present invention, there is provided the method for molding an optical member according to the second aspect of the invention, wherein the mold release step is performed by releasing the first resin mold after the first mold release step. The method further includes a step of attaching to the molded body a support member that supports a portion between adjacent lenses on the surface.

Thereby, in the second mold releasing step, it is possible to prevent the optical surface of the molded product from being damaged, or the lens from being dissipated inadvertently during the mold release.

According to a fifth aspect of the present invention, there is provided the optical member molding method according to any one of the first to fourth aspects, wherein the mold releasing step is performed in the hard portion of at least one of the first mold and the second mold. When the substrate is peeled from the elastic resin mold, gas is supplied between the substrate and the resin mold.

By supplying a gas (for example, air) between the substrate and the resin mold, the substrate can be easily peeled from the resin mold.

According to a sixth aspect of the present invention, there is provided the optical member molding method according to any one of the first to fifth aspects, wherein the first resin mold and the second resin are used for manufacturing the optical member. At least one of the molds is used when manufacturing another optical member.

The resin mold having elasticity is easy to be peeled off by bending, and has a small mold release resistance at the time of mold release. Therefore, even when it is repeatedly used for molding, there is little wear and damage and excellent durability. Therefore, by repeatedly using the same resin mold, optical members and lenses having the same shape can be produced in large quantities, and as a result, the cost can be significantly reduced.

According to a seventh aspect of the present invention, there is provided the optical member molding method according to any one of the first to sixth aspects, wherein a spacer is provided between the first substrate and the second substrate in the mold facing step. By interposing, the first resin mold and the second resin mold are kept at a predetermined interval.

Since both the first resin mold and the second resin mold have elasticity, it is difficult to accurately adjust the gap between them by a method such as directly interposing a spacer, but both are hard. By interposing a spacer between the first substrate and the second substrate, the distance between the first resin mold and the second resin mold both having elasticity can be adjusted with high accuracy.

The method for molding an optical member according to claim 8 is the invention according to any one of claims 1 to 7, wherein the thickness of at least one of the first resin mold and the second resin mold is 100 μm. It is 10 mm or less.

If the thickness of at least one of the first resin mold and the second resin mold is 100 μm or more, a sufficient lens shape can be transferred, and if it is 10 mm or less, release from the molded product becomes easy. .

The method for molding an optical member according to claim 9 is the method according to any one of claims 1 to 8, wherein the mold facing step positions the first mold and the second mold in a direction perpendicular to the mold clamping. The method further includes the step of:

This makes it possible to mass-produce lenses with curved optical surfaces on both sides at low cost.

The method for molding an optical member according to claim 10 is the invention according to any one of claims 1 to 9, wherein at least one of the first resin mold and the second resin mold is a silicone resin or fluorine. It consists of resin.

As a result, it has both good flexibility and releasability, and also has excellent adhesion to hard substrates.

The optical member molding method according to an eleventh aspect is characterized in that, in the invention according to the fourth aspect, the support member includes an air adsorbing portion that supports the molded product by air adsorption.

This makes it possible to reliably support the molded product and to quickly release the molded product by releasing the suction and decompression after the mold release is completed, and it is difficult to reduce the speed of the manufacturing process.

The optical member according to claim 12 is manufactured by the optical member manufacturing method according to any one of claims 1 to 11.

The method for manufacturing a lens according to claim 13 is such that the optical members obtained by the manufacturing method according to any of claims 1 to 11 are one by one when viewed from the lens optical axis direction, or It is characterized by comprising a singulation process for dividing into multiple pieces when viewed from the lens optical axis direction.

The lens according to claim 14 is manufactured by the lens manufacturing method according to claim 13.

According to the present invention, it is possible to provide an optical member and a lens manufacturing method capable of mass-producing a highly accurate lens at low cost, and an optical member and a lens manufactured thereby.

BRIEF DESCRIPTION OF THE DRAWINGS It is a typical external view of the optical member and lens concerning 1st Embodiment, (a) (b) is a perspective view and sectional drawing of an optical member, (c) (d) is a perspective view of a lens, and It is sectional drawing. (A)-(c) is a figure which shows the process of manufacturing a resin mold from a master type | mold. (A)-(k) is a figure which shows the process of manufacturing a lens array using a resin type | mold. It is a figure which shows the method of sticking a resin mold to a substrate, (a) is a figure which looked at a board and a resin mold from the front, (b), (c) is a figure seen from the side, The resin-type transfer surface is omitted. (A)-(c) is the figure which looked at the board | substrate and the resin type | mold from the front in the state which has arrange | positioned the spacer. It is a partial cross section figure of the 1st resin type concerning a 2nd embodiment. It is a perspective view of the lens array shape | molded by 2nd Embodiment. (A)-(c) is a figure which shows the method of separating a lens into pieces from the lens array shape | molded by 2nd Embodiment. (A) is sectional drawing of the optical member which has two or more Fresnel lenses concerning a modification, (b) is sectional drawing shown in the state which separated the Fresnel lens into pieces. It is a figure which shows the positioning method concerning 3rd Embodiment. (A)-(c) is a figure which shows the example of an alignment mark. (A)-(f) is a figure which shows the process of manufacturing a lens array with both spherical surfaces using a resin type | mold.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, the dimension ratio of drawing is exaggerated on account of description, and may differ from an actual ratio.

<First Embodiment>
FIGS. 1A to 1D are schematic external views of an optical member and a lens according to the first embodiment. As shown in FIGS. 1A and 1B, the optical member OE includes a plurality of lenses LS each having a curved first optical surface OP1 and a flat second optical surface OP2 arranged in a two-dimensional manner. It is composed of a single resin. As shown in FIGS. 1C and 1D, the lens LS has the optical member OE of FIGS. 1A and 1B so that it has a single optical surface when viewed from the optical axis direction. Each lens is obtained by dividing into individual pieces (for example, dicing). The optical member OE may be a lens array in which lenses LS are arranged in an array (two-dimensionally) or may be arranged in only one row (one-dimensionally). Also, the lens LS may be a lens in which a plurality of lenses are arranged as viewed from the optical axis direction.

As a resin for optical members, an energy curable resin that is cured by applying energy is used. For example, a photocurable resin that is cured by applying light, or a thermosetting that is cured by applying heat. Examples thereof include resins. In particular, a UV curable resin that is cured by irradiation with UV light is preferable. The energy curable resin before curing is generally low in viscosity, but as will be described later, from the viewpoint of molding with an elastic resin mold, it is particularly 10 mPa · s to 1000 mPa · s in the state before curing. What has a viscosity is preferable.

The optical member OE and the lens LS are used as an imaging optical system built in a thin portable electronic device. In the case of a lens composed of a single lens as viewed from the optical axis direction, for example, in the case of a lens used in an imaging optical system in combination with other lenses, or a lens in which a plurality of lenses are arranged as viewed from the optical axis direction, for example, It can be used in an optical system for a compound eye imaging device that combines a plurality of captured images to obtain a single image.

2 and 3 are diagrams showing the lens manufacturing process. A manufacturing process of a lens array as an optical member will be described with reference to FIGS.

(Production of elastic resin mold)
First, as shown in FIG. 2A, for example, a master material MM is manufactured by cutting a base material made of hard metal such as super steel or ceramic. In the master type MM, the mother optical surface MM1 which is the optical surface shape of the final lens is formed in an array, and a positioning wall portion MM2 is formed around the mother optical surface MM1. Next, a resin material for the resin mold is placed in the master mold MM. The resin used in the resin mold is excellent in moderate flexibility and surface water repellency, and when UV curable resin or the like is used as the resin for the optical member, it transmits ultraviolet rays (300 nm to 400 nm). Having a high transmittance, particularly those having a transmittance of 90% or more are preferred. Silicone-based resins and fluorine-based resins are particularly preferable because they have moderate flexibility and release properties with respect to UV curable resins. These materials preferably have a rubber hardness after curing of 30 to 90. If the rubber hardness is high, deformation of the mold can be suppressed and high transfer accuracy can be stably maintained. However, if the rubber hardness is too high, the releasability is deteriorated. In view of ease of use and accuracy in the process, the rubber hardness is more preferably 60-80. As specific silicone resins, product names SIM240, SIM260, SIM360 manufactured by Shin-Etsu Chemical Co., Ltd. can be suitably used. The silicone resin may be a two-component mixed type or a one-component type.

Here, after mixing the two-component mixed type silicone resin material SMT and defoaming treatment, as shown in FIG. 2B, an appropriate amount is dropped inside the wall portion MM2, and further shown in FIG. 2C. As described above, the parallel plate PP made of glass is overlapped and lowered until it hits the wall portion MM2, and the resin material SMT is pressed. In this state, it is put into an electric furnace, heated for a predetermined time, and then demolded. Thereby, a first silicone resin mold SM1 (first resin mold having elasticity) having a rubber hardness of 60, a width of 80 mm, and a thickness Δ1 (100 μm or more and 10 mm or less) is formed. The first silicone resin mold SM1 has a plurality of transfer surfaces SM1a, which are transferred from the mother optical surface MM1 and recessed in a concave shape, arranged in an array. Thereafter, as will be described later, a glass first substrate ST1 (hard first substrate) is brought into close contact with the surface opposite to the transfer surface SM1a of the silicone resin mold SM1 as will be described later. Although not shown in the drawing, through the same process, a second silicone resin type SM2 (a second elastic material having a rubber hardness of 60, a height and width of 80 mm, and a thickness Δ2 (100 μm or more and 10 mm or less)) is formed. Resin mold) is formed and adhered to the second glass substrate ST2 (hard second substrate). The second substrate ST2 has a through hole SM2a at a position facing the second silicone resin mold SM2. The first substrate ST1 and the first silicone resin mold SM1 constitute a first mold, and the second substrate ST2 and the second silicone resin mold SM2 constitute a second mold. If the first resin mold and the second resin mold have a thickness of 100 μm or more, a sufficient lens shape can be transferred, and if the thickness is 10 mm or less, release from the molded product becomes easy.

The hard substrate is preferably one having a higher hardness than an elastic resin mold and having an elastic modulus of 0.1 Gpa or more. As a specific material, in addition to the glass used in the present embodiment, a metal such as stainless steel, an acrylic base material, and the like can be used, but when a UV curable resin is used as an energy curable resin for an optical member, Glass or acrylic that transmits UV light is preferred. In the present embodiment, since both the substrate and the resin mold are light transmissive, both the first mold and the second mold are light transmissive.

(Lens array molding)
Next, the first silicone resin mold SM1 is brought into close contact with the first substrate ST1 made of glass. In the present embodiment, a glass parallel plate having a through hole ST1a at a position facing the first silicone resin mold SM1 is used as the first substrate ST1, but the parallel plate PP described above is used. It can also be used.

At this time, if bubbles or the like remain between the first silicone resin mold SM1 and the first substrate ST1, accurate molding is hindered, and as shown by arrows in FIGS. 4 (a) and 4 (b). In addition, it is desirable that the first substrate ST1 is gradually adhered to the first substrate ST1 so as to be bonded from the end of the first silicone resin mold (corner if polygonal). Alternatively, as shown in FIG. 4C, the first silicone resin mold SM1 may be gradually pressed against the first substrate ST1 by the roller RL from one end to the other end. Since the silicone resin has adhesiveness, the flat surface opposite to the transfer surface of the first resin mold SM1 comes into close contact with the flat first substrate ST1 by pressing with the roller RL. The second silicone resin type SM2 (the contact surface with the UV curable resin RUV is flat) is also brought into close contact with the second substrate ST2 in the same procedure.

Thereafter, as shown in FIG. 3A, a spacer SP is disposed on the first substrate ST1 around the first silicone resin mold SM1. The shape of the spacer SP and the position on the substrate ST1 are not particularly limited as long as the distance between the substrate ST1 and the substrate ST2 is appropriately maintained, and various shapes and arrangements can be adopted. In the present embodiment, the spacers SP having a height Δ3 are cylindrical, and are arranged at four equal intervals around the first silicone resin mold SM1, as shown in FIG. As shown in FIG. 5 (b), it is arranged at three locations around the first silicone resin mold SM1. As the spacer SP, a block shape as shown in FIG. 5C may be adopted and disposed on both sides of the first silicone resin mold SM1.

Next, as shown in FIG. 3B, an appropriate amount of UV curable resin RUV is dropped onto the first silicone resin mold SM1. Further, as shown in FIG. 3 (c), a second silicone resin type SM2 (contact surface with the UV curable resin RUV is formed in a separate step), which is in close contact with the second substrate ST2, is formed. The first silicone resin type SM1 is opposed so that the UV curable resin RUV is interposed therebetween. Then, the second silicone resin mold SM2 is brought close to the substrate ST2 at a mold clamping speed of 0.01 mm / s to 1 mm / s until it abuts against the spacer SP (mold facing step). When the mold is clamped at a relatively slow speed of about 0.01 mm / s to 1 mm / s, it is easy to suppress the mixing of bubbles.

Through this mold facing process, two molds made of an elastic resin mold that are in close contact with a hard substrate are opposed to each other at a predetermined interval with an energy curable resin interposed therebetween. Accordingly, the gap between the first substrate ST1 and the second substrate ST2 is adjusted by the spacer SP, so that the gap between the first silicone resin mold SM1 and the second silicone resin mold SM2 is (Δ3-Δ1- Δ2) is always adjusted to be constant (see FIG. 3D). Since both the first resin mold SM1 and the second resin mold SM2 have elasticity, it is difficult to accurately adjust the gap between the two by the method of interposing the spacer in contact with the resin mold, By using two substrates, it is possible to easily adjust the distance between the two resin molds having elasticity. Here, since energy curable resins generally have low viscosity, there is little risk of deformation of the transfer surface during mold clamping even when molding is performed using an elastic resin mold as a mold, and highly accurate transfer molding It can be performed. Since the UV curable resin RUV has a low viscosity and escapes to the surrounding side opened when the mold is clamped, the transfer surface SM1a is not deformed without pressing the first silicone resin mold SM1. At this time, if the lens to be molded is not too thick, the UV curable resin RUV will not escape more than necessary due to surface tension.

Note that the gap between the first substrate ST1 and the second substrate ST2 is detected by using a sensor or the like to detect the position of the surface of the substrate in close contact with the silicone resin mold or the silicone resin mold, instead of using a spacer. The thickness accuracy may be mechanically obtained by feeding back to a support mechanism having a drive mechanism incorporating a servo motor, a stepping motor, etc., and controlling the position of the mold.

Thereafter, as shown in FIG. 3D, when UV light is irradiated from the outside, the light passes through the second substrate ST2 and the second silicone resin type SM2, reaches the UV curable resin RUV, and is cured. Therefore, the transfer surface SM1a of the first silicone resin mold SM1 is accurately transferred to the cured UV curable resin RUV. Thereby, a lens array LA having a plurality of lenses LS is formed as a molded body (resin curing step). The UV light irradiation may be performed from either the second mold side or the first mold side, or from both sides.

Thereafter, a first release step shown in FIGS. 3 (e) and 3 (f), a second release step comprising the steps of FIGS. 3 (g) and 3 (i), and FIG. 3 (h). The mold release process including the attachment process of the detachable sheet | seat shown in FIG.

Specifically, first, as shown in FIG. 3E, the second substrate ST2 is peeled from the second silicone resin mold SM2. At this time, when a gas is blown from the outside through the through hole ST2a of the second substrate ST2, the gas is filled between the second silicone resin type SM2 and the second substrate ST2, and the second silicone resin. The second substrate ST2 is easily peeled off from the mold SM2. Factory air or the like is used as the gas to be supplied. The pressure is preferably about 10 KPa to 500 KPa. When peeling the substrate from the resin mold, a hard substrate may be held by a vacuum suction table or the like to assist the peeling.

Thereafter, as shown in FIG. 3F, the second silicone resin mold SM2 is peeled off from the lens array LA which is a molded body (first release step). The second silicone resin mold SM2 has elasticity and is relatively soft. Therefore, the second silicone resin mold SM2 can be easily peeled off from the lens array LA by peeling it while bending from the end. At this time, by releasing the mold while bending the mold, the molded product and the resin mold are released linearly, so that the release resistance can be reduced. Therefore, even when molding an optical member in which a plurality of lenses are arranged and the mold release resistance tends to be high due to the uneven shape, the mold can be easily released without degrading the accuracy of the lens. At this time, since the back surface side of the lens array LA is in close contact with the first silicone resin mold SM1, the first silicone resin mold SM1 side is hardly peeled off.

Further, as shown in FIG. 3G, the first silicone resin mold SM1 and the lens array LA are integrally peeled from the first substrate ST1. At this time, when air is blown from the outside through the through hole ST1a of the first substrate ST1, the air is filled between the first silicone resin mold SM1 and the first substrate ST1, and the first substrate ST1. Therefore, the first silicone resin mold SM1 is easily peeled off.

Thereafter, as shown in FIG. 3 (h), a detachable thin resin sheet FM (or adhesive tape) is attached to the surface of the lens array LA from which the second silicone resin mold SM2 has been peeled off, and reversed. By attaching a detachable sheet to the surface of the molded product from which the first resin mold has been released, the optical surface of the molded product is damaged or inadvertently released during the second mold release step described later. It is possible to prevent the lens from being dissociated into individual pieces. In addition, the optical member and the sheet can be handled integrally even after the second mold release step described later is completed, and the workability and transportability are excellent. Next, as shown in FIG. 3I, the first silicone resin mold SM1 is peeled off from the lens array LA (second mold release step). Since the first silicone resin mold SM1 is relatively soft, the first silicone resin mold SM1 can be easily peeled off from the lens array LA by being peeled off while being bent from the end. At this time, since the back surface side of the lens array LA is in close contact with the sheet FM over the entire surface, it is difficult to peel off from the lens array LA. By sequentially releasing the two resin molds in this way, the release of the other resin mold can be performed in a state in which one of the resin molds is not easily peeled off from the optical member, thereby improving workability. The first lens array SM1 is again brought into close contact with the first substrate ST1, and the second lens resin type SM2 is brought into close contact with the second substrate ST2 so that the next lens array is obtained. Reusable for LA molding.

(Production of lens)
The lens array LA formed in this way is conveyed to the next process while being stuck on the sheet FM, and is cut at the position of the arrow C in FIG. As shown in FIG. 2, the lens is divided into pieces for each lens LS. Thereafter, the sheet FM is peeled off from the lens LS and incorporated into the imaging device.

<Second Embodiment>
A second embodiment will be described. FIG. 6 shows a first silicone resin mold SM1 in which a raised portion SM1b having a V-shaped cross section is formed between adjacent transfer surfaces ST1a. When the lens array LA is transferred and molded using the first silicone resin mold SM1 as described above, as shown in FIG. 7, the raised portion SM1b is interposed between the lenses LS transferred by the transfer surface SM1a. A plurality of V-shaped valleys (V grooves) LV corresponding to the above are formed. The angle of the valley LV is preferably 20 ° to 60 °.

The lens array LA formed in this way can be easily separated into lenses LS in the following manner. In the example shown in FIG. 8A, a tensile stress is generated in the lens array LA by pulling the sheet FM to both sides (or on a diagonal line), and cleaving occurs at the innermost part of the valley LV that is the most fragile. be able to.

In the example shown in FIG. 8B, bending stress can be generated in the lens array LA by bending the sheet FM to the back side, and cleaving can be caused in the innermost part of the valley LV that is the most fragile.

In the example shown in FIG. 8C, bending stress is generated in the lens array LA by extruding the sheet FM from the back of the individual lens LS, and cleaving is performed at the innermost portion of the valley groove LV that is the most fragile. Can be generated. This is suitable when the outer diameter of the lens LS is circular.

In the first embodiment and the second embodiment, an optical member or a lens provided with a first optical surface having a convex curved surface and a flat second optical surface is shown. However, the shape of the optical surface is not limited to this. For example, it may have a concave curved surface shape or an aspherical shape, or it may have a fine structure in which fine irregularities having a cross-sectional V shape or a stepped shape are repeated. In particular, in the case of having an aspherical shape or a fine structure including both concave and convex portions, the above-described manufacturing method is particularly effective because release resistance generally tends to increase. In the first and second embodiments, the lens may be used as an optical system for an auxiliary light source mounted on a portable electronic device. In this case, as shown in FIGS. 9A and 9B, a lens array LA having a so-called Fresnel lens FL having an optical surface on which an annular concavo-convex structure is formed may be formed. FIGS. 9A and 9B show an example in which a cutting V-groove LV similar to that described in the second embodiment is provided.

<Third Embodiment>
A third embodiment will be described. In the present embodiment, the transfer surface SM2a for transferring the curved surface transfer surface of the lens LS is also formed in the second silicone resin mold SM2. Then, in the mold clamping step shown in FIG. 3C in the above-described embodiment, the mold clamping of the first silicone resin mold SM1 and the second silicone resin mold SM2 is performed so as to suppress the eccentricity of both surfaces of the optical surface of the lens. Positioning in the orthogonal direction is required.

Therefore, in the present embodiment, alignment marks SM1c and SM2c are formed on the first silicone resin mold SM1 and the second silicone resin mold SM2, respectively. The alignment marks SM1c and SM2c are formed with a concave or convex portion having a predetermined shape at a position different from the transfer surface at the same time when the master mold as shown in FIG. By transferring to each of the silicone resin mold SM1 and the second silicone resin mold SM2, it can be formed with high positional accuracy. As the shapes of the alignment marks SM1c and SM2c, ones having good visibility such as a circular shape shown in FIG. 11 (a), a cross shape shown in FIG. 11 (b), and a star shape shown in FIG. 11 (c) can be arbitrarily selected. .

At the time of mold clamping, as shown in FIG. 10, cameras CA1 and CA2 are arranged on the second substrate ST2 side, and the first silicone resin mold SM1 is observed through the second substrate ST2 and the second silicone resin mold SM2. (Read position coordinates). Here, if the control device (not shown) determines that the alignment marks SM1c and SM2c are displaced based on the read position coordinates, the second silicone resin mold SM2 together with the second substrate ST2 held by the robot or the like, Move in the direction perpendicular to mold clamping. When the alignment marks SM1c and SM2c observed with the cameras CA1 and CA2 match, the mold is clamped while maintaining the state. Thus, the first mold and the second mold are positioned in a direction perpendicular to the mold clamping. The positioning may be performed by moving the first silicone resin mold SM1 side.

As shown in FIGS. 12A to 12F, even in the case of the optical member OE having the curved optical surfaces OP1 and OP2 on both surfaces, the same as described in the second embodiment between the lens portions. Alternatively, a cleaving V groove LV may be provided. In this case, after one mold SM1 is released as shown in FIGS. 12A and 12B, it is connected to an external air adsorption mechanism (not shown) as shown in FIG. The connecting portion CT between the lenses LS of the exposed molded product is held by the standing portion (air adsorption portion) WL of the support member HLD. Accordingly, it is possible to prevent the optical surface OP2 of the molded product from being damaged or being inadvertently separated into pieces during the mold release and dissipating the lens LS in the second mold release step. Then, as shown in FIG. 12D, the hard substrate ST2 is peeled off, and the mold SM2 on the opposite side is released. Thereafter, the lens array (optical element) LA can be obtained by removing the support member HLD from the state shown in FIG. Furthermore, as shown in FIG. 12F, the lens LS can be separated into pieces by cleaving the obtained lens array LA with a cleaving V groove LV. By using the supporting member HLD provided with an air adsorption mechanism, the molded product can be reliably supported, and the molded product can be quickly released by releasing the suction and pressure reduction after the mold release. In addition, it is difficult to reduce the speed of the manufacturing process.

In the above embodiment, an uncured resin is disposed in one resin mold, and then the resin is pressed by the other resin mold so that the resin is interposed between the two molds. After making two molds face each other at a predetermined interval, an uncured resin may be filled in a gap between the two molds. Moreover, in the said embodiment, although the hard board | substrate was peeled from the resin type | mold by supplying gas, the technique of peeling is not restricted to this, For example, a wedge is bitten between a board | substrate and a resin type | mold. You may make it peel by carrying out.

The present invention is not limited to the embodiments described in the specification, and other embodiments and modifications are included for those skilled in the art from the embodiments and technical ideas described in the present specification. it is obvious. For example, the mold is released from the second resin mold, but the mold may be released from the first resin mold.

FM sheet LA lens array LS lens LV valley MM master mold MM1 mother optical surface MM2 wall PP parallel plate RL roller RUV UV curable resin SM1 first resin mold SM1a transfer surface SM1b raised portion SM1c alignment mark SM2 second resin Type SM2a Transfer surface SMT Resin material SP Spacer ST1 First substrate ST1a Through hole ST2 Second substrate ST2a Through hole

Claims

A method of manufacturing an optical member having at least a plurality of lenses arranged in a row,
A first mold obtained by adhering an elastic first resin mold having a first transfer surface for transferring a first optical surface of the plurality of lenses to a hard first substrate; A second mold obtained by bringing an elastic second resin mold having a second transfer surface for transferring the second optical surfaces of a plurality of lenses into close contact with a hard second substrate; A mold facing step in which a curable resin is interposed to face each other at a predetermined interval;
A resin curing step of forming a molded body by curing by applying energy to the energy curable resin interposed between the first mold and the second mold;
A mold release step of releasing the first mold and the second mold from the molded body to obtain the optical member,
In the mold release step, for at least one of the first mold and the second mold, after releasing the hard substrate from the resin mold having elasticity, the mold is released from the molded body while bending the resin mold. A method for manufacturing an optical member.
The mold release step
For one of the first mold and the second mold, after peeling the substrate from the resin mold, the first mold release step of releasing the molded body from the molded body while bending the resin mold from which the substrate has been peeled;
After the first mold releasing step, the other of the first mold and the second mold is released from the molded body while the substrate is peeled from the resin mold and then the resin mold from which the substrate has been peeled is bent. The method for producing an optical member according to claim 1, further comprising a second release step.
3. The mold release step further includes a step of attaching a removable sheet to the surface of the molded product from which the first resin mold is released after the first mold release step. The manufacturing method of the optical member of description.
The mold release step includes a step of attaching a support member that supports a portion between adjacent lenses on the surface of the molded product from which the first resin mold is released after the first mold release step to the molded body. Furthermore, the manufacturing method of the optical member of Claim 2 characterized by the above-mentioned.
In the releasing step, when the hard substrate in at least one of the first mold and the second mold is peeled off from the resin mold having elasticity, gas is generated between the substrate and the resin mold. 5. The method for producing an optical member according to claim 1, wherein the optical member is supplied.
At least one of the first resin mold and the second resin mold used for manufacturing the optical member is used when manufacturing another optical member. The method for producing an optical member according to any one of claims 1 to 5.
In the mold facing step, a spacer is interposed between the first substrate and the second substrate to keep the first resin mold and the second resin mold at a predetermined interval. The method for producing an optical member according to any one of claims 1 to 6.
The method for manufacturing an optical member according to any one of claims 1 to 7, wherein a thickness of at least one of the first resin mold and the second resin mold is 100 袖 m or more and 10 mm or less.
9. The method of manufacturing an optical member according to claim 1, wherein the mold facing step further includes a step of positioning the first mold and the second mold in a mold clamping orthogonal direction.
10. The method of manufacturing an optical member according to claim 1, wherein at least one of the first resin mold and the second resin mold is made of a silicone resin or a fluororesin.
The method for manufacturing an optical member according to claim 4, wherein the support member includes an air adsorption portion that supports the molded article by air adsorption.
An optical member manufactured by the method for manufacturing an optical member according to any one of claims 1 to 11.
The optical members obtained by the production method according to any one of claims 1 to 11 are one by one when viewed from the lens optical axis direction, or a plurality of optical members are viewed from the lens optical axis direction. Thus, the manufacturing method of the lens characterized by providing the individualization process which separates into pieces.
A lens manufactured by the lens manufacturing method according to claim 13.