WO2021131348A1

WO2021131348A1 - Bonding-type optical element and method for manufacturing bonding-type optical element

Info

Publication number: WO2021131348A1
Application number: PCT/JP2020/041510
Authority: WO
Inventors: 中林　耕基
Original assignee: 富士フイルム株式会社
Priority date: 2019-12-27
Filing date: 2020-11-06
Publication date: 2021-07-01
Also published as: JPWO2021131348A1

Abstract

This bonding-type optical element is provided with: a first optical element; a second optical element; and a bonding layer that is formed of a resin-made adhesive agent, that is for bonding the first optical element and the second optical element, and that has distortion for deforming the first optical element and/or the second optical element.

Description

Bonded optical element and manufacturing method of bonded optical element

The technique of the present disclosure relates to a junction type optical element and a method for manufacturing the junction type optical element.

Japanese Patent Application Laid-Open No. 2009-530689 is a wave surface aberator having two transparent plates and having a layer of a polymer material between the transparent plates, and can change the refractive index of the layer of the polymer material. , Thereby creating a refractive index profile and the refractive index profile of the layer of polymeric material is stable when the aberator is exposed to heat or light.

The wave surface abrator described in Japanese Patent Application Laid-Open No. 2009-530689 is manufactured by the following steps a to d.
a. A step in which a layer of a polymerizable material comprising at least one polymer and one or more monomers is formed between two transparent plates, and the polymerizable material has an initial index of refraction.
b. The polymerizable material is subjected to simultaneous thermal stimulation and variable photostimulation, and the polymerizable material is subjected to (i) variable pattern polymerization without completely consuming one or more monomers. (Ii) A step of achieving a first intermediate variable index profile,
c. The diffusion step is accelerated by heating the partially cured polymerizable material of (b), and the uncured monomer is diffused from the less cured region to the more cured region, and the second intermediate. Steps to achieve a variable index profile,
d. The partially cured polymerizable material of (c) is subjected to simultaneous thermal stimulation and uniform photostimulation to cure substantially all of the remaining one or more monomers, resulting in variable refraction. Steps to achieve rate profile.

One embodiment according to the technique of the present disclosure is a bonded optical element and a bonded optical element capable of increasing the optical path difference with respect to the thickness of the bonded layer as compared with the wave surface avelator described in Japanese Patent Application Laid-Open No. 2009-530689. Providing a manufacturing method for.

The bonding type optical element of the present disclosure is a bonding layer formed by a first optical element, a second optical element, and a resin adhesive to bond the first optical element and the second optical element. A bonding layer having a strain that deforms at least one of an optical element and a second optical element is provided.

It is preferable that at least one of the first optical element and the second optical element has an aspherical shape in a state of being joined by a joining layer.

Of the first optical element and the second optical element, the optical element having an aspherical shape when joined by the joining layer preferably has a spherical shape before being joined by the joining layer.

The aspherical shape is preferably a non-rotationally symmetric shape.

The adhesive preferably contains a photocurable resin.

It is preferable that at least one of the first optical element and the second optical element transmits light for curing the photocurable resin.

The distortion is preferably a distortion that deforms at least one of the first optical element and the second optical element into a shape according to the set optical characteristics.

The method for manufacturing a bonded optical element of the present disclosure is a resin adhesive that serves as a bonding layer for bonding the first optical element and the second optical element, and a liquid adhesive is used as the first optical element and the first optical element. 2 A filling step of filling between the optical element and a gelling step of gelling the adhesive by giving a first curing stimulus to the adhesive in a liquid state, and changing the intensity of the first curing stimulus. This includes a gelling step in which the curing speed of the adhesive is made different in a plurality of regions, and a main curing step in which the adhesive is cured by giving a second curing stimulus to the adhesive.

It is preferable that the first hardening stimulus and the second hardening stimulus are of the same type.

It is preferable that the main curing step is performed without interposing another step between the gelation step and the gelation step.

The other process is preferably a heating process.

In this curing step, the adhesive in the region having a slow curing speed among the plurality of regions is shrunk more than the adhesive in the region having a high curing speed.

In this curing step, it is preferable to generate distortion that deforms at least one of the first optical element and the second optical element.

The aspherical shape is preferably a non-rotationally symmetric shape.

The adhesive preferably contains a photocurable resin.

It is a figure which shows the manufacturing apparatus. It is a perspective view which shows the 1st optical element. It is a perspective view which shows the 2nd optical element. It is a flowchart which shows the filling process. It is a figure which shows the state transition of an adhesive, FIG. 5A shows a state before curing, FIG. 5B shows a gelled state, and FIG. 5C shows a completely cured state. It is a block diagram of a manufacturing apparatus main body. It is a block diagram which shows the computer which comprises the control device. It is mainly a block diagram of a CPU of a control device. It is a figure which shows the setting screen. It is a figure which shows an example of a junction type optical element and design shape information. It is a figure which shows an example of an irradiation profile. It is a figure which shows the state transition of the adhesive at the boundary part of two regions where the curing rate of the adhesive is different, FIG. 12A is at the end of a filling process, FIG. 12B is in the middle of a gelling process, and FIG. The state of the adhesive at the end is shown. It is a figure which shows the state transition of the adhesive at the boundary part of two regions where the curing rate of the adhesive is different, FIG. 13A shows the state of the adhesive in the middle of the main curing step, and FIG. Shown. It is a flowchart which shows the procedure of the manufacturing method of a junction type optical element. It is a figure which shows the junction type optical element which only the concave surface of the 1st optical element has an aspherical shape. It is a figure which shows the junction type optical element which has a non-rotational symmetric aspherical shape. It is a figure which shows the 1st optical element information of an Example. It is a figure which shows the 2nd optical element information of an Example. It is a figure which shows the adhesive information of an Example. It is a figure which shows the irradiation profile of an Example. It is a figure which shows the deformation amount of the facing surface of the 1st optical element of an Example. It is a figure which shows the amount of change of the optical path length of the junction layer of an Example. It is a figure which shows another example of the region which makes the curing rate of an adhesive different.

In FIG. 1, the manufacturing apparatus 2 is an apparatus for manufacturing a junction type optical element 10, and includes a manufacturing apparatus main body (hereinafter, abbreviated as the main body) 11 and a control device 12. The junctional optical element 10 is used, for example, as a lens of an optical device such as a digital camera, a surveillance camera, or a projector, or a lens of a vision correction tool such as eyeglasses or a contact lens.

The junction type optical element 10 is composed of a first optical element 13 and a second optical element 14. The first optical element 13 is a plano-concave lens (see FIG. 2), and the second optical element 14 is a plano-convex lens (see FIG. 3). The bonding type optical element 10 is formed by bonding a concave surface 13A of the first optical element 13 and a convex surface 14A of the second optical element 14 with a bonding layer 15. In FIG. 1, the thickness direction of the first optical element 13 and the second optical element 14 is the Z direction, the width direction of the first optical element 13 and the second optical element 14 orthogonal to the Z direction is the X direction, and the depth direction is the depth direction. The Y direction.

The control device 12 is, for example, a desktop personal computer, and controls the operation of the main body 11. The control device 12 is communicably connected to the main body 11.

As shown in FIG. 2, the concave surface 13A of the first optical element 13 has a spherical shape before being joined by the joining layer 15. Similarly, as shown in FIG. 3, the convex surface 14A of the second optical element 14 has a spherical shape before being joined by the joining layer 15. Further, the first optical element 13 and the second optical element 14 transmit ultraviolet UV (see FIG. 5). Ultraviolet UV is an example of "light" according to the technique of the present disclosure.

Before the adhesive 20 (see FIG. 5), which is cured to form the bonding layer 15, is introduced into the main body 11 between the concave surface 13A of the first optical element 13 and the convex surface 14A of the second optical element 14. It is filled. Specifically, the adhesive 20 is filled in the procedure shown as step ST100 in FIG. Step ST100 is an example of a "filling step" according to the technique of the present disclosure.

In FIG. 4, first, as shown in step ST110, the concave surface 13A of the first optical element 13 and the convex surface 14A of the second optical element 14 are cleaned up. Next, as shown in step ST120, the liquid adhesive 20 is applied to the concave surface 13A. Subsequently, as shown in step ST130, the concave surface 13A and the convex surface 14A are bonded together. Then, as shown in step ST140, the concave surface 13A and the convex surface 14A are rubbed against each other to remove air bubbles from the adhesive 20, and the adhesive 20 is thinly spread over the entire surface of the concave surface 13A and the convex surface 14A. Finally, as shown in step ST150, the adhesive 20 protruding from the end face is removed. Hereinafter, the combination of the first optical element 13 and the second optical element 14 in a state where the adhesive 20 is filled between the concave surface 13A and the convex surface 14A may be referred to as a pre-bonding optical element 10X. The filling step shown in step ST100 may be performed in the main body 11.

In FIG. 5, the adhesive 20 contains an ultraviolet curable resin 21. The UV curable resin 21 has a monomer 23 and a polymerization initiator 24. The ultraviolet curable resin 21 is an example of a "photocurable resin" according to the technique of the present disclosure. In addition to the monomer 23, an ultraviolet curable resin 21 containing an oligomer may be used.

FIG. 5A shows immediately after the completion of the filling step shown in FIG. 4 and before curing of the adhesive 20. In this case, the adhesive 20 is in a liquid state. From this state, as shown in FIG. 5B, for example, when ultraviolet UV is irradiated from the first optical element 13 side, the polymerization initiator 24 generates radicals by the ultraviolet UV transmitted through the first optical element 13. As a result, the radical polymerization reaction of the monomer 23 centering on the polymerization initiator 24 is started, and the ultraviolet curable resin 21 is gradually polymerized by repeating the chained addition reaction of the monomer 23.

At the initial stage of UV UV irradiation, the UV curable resin 21 is still in a liquid state, and the UV curable resin 21 is formed with a system having a large number of isolated small molecular weight molecular chains. At this time, although there is a difference depending on the magnitude of the molecular weight, since each molecular chain has fluidity, even if the ultraviolet curable resin 21 shrinks due to the radical polymerization reaction, the fluidity of the ultraviolet curable resin 21 causes it. The first optical element 13 and the second optical element 14 are not deformed, and the bonding layer 15 is not distorted.

As the radical polymerization reaction progresses over time, the UV curable resin 21 becomes a gel. In this state, the molecular chain shows a three-dimensional network structure coupled to the first optical element 13 and the second optical element 14. The ultraviolet curable resin 21 is formed with a system in which the monomer 23 and the polymerization initiator 24 are dispersed in the gaps of the three-dimensional network structure. Even if the UV curable resin 21 shrinks until just before reaching the gel state, the bonding layer 15 is not distorted due to the fluidity of the UV curable resin 21. Although FIG. 5 shows a two-dimensional network structure in the XZ two-dimensional plane, in reality, as described above, the ultraviolet curable resin 21 has a three-dimensional network in which molecular chains are continuous in the Y direction as well. It exhibits a structure.

When the radical polymerization reaction further proceeds, substantially all the monomers 23 are polymerized, and the radical polymerization reaction is stopped, the ultraviolet curable resin 21 becomes a solid state as shown in FIG. 5C. At this time, as a result of the cross-linking of each molecular chain becoming dense, the elastic modulus of the ultraviolet curable resin 21 increases. Then, the ultraviolet curable resin 21 contracts in the direction of the arrow that shortens the distance between the concave surface 13A of the first optical element 13 and the convex surface 14A of the second optical element 14, and distortion occurs.

In FIG. 6, the main body 11 has a light source 30, an irradiation optical system 31, an intensity modulation element 32, and a stage 33. The light source 30 emits ultraviolet UV under the control of the light source driver 35. The light source 30 is, for example, an LED (Light Emitting Diode) and / or a black light. The irradiation optical system 31 irradiates the ultraviolet UV emitted from the light source 30 toward the pre-bonding optical element 10X. The intensity modulation element 32 modulates the intensity of ultraviolet UV rays that have passed through the irradiation optical system 31 under the control of the intensity modulation element driver 36. The intensity modulation element 32 is, for example, an element using a liquid crystal, and can increase or decrease the intensity of ultraviolet UV rays in a specific region of the pre-junction optical element 10X as compared with other regions. The stage 33 holds the pre-junction optical element 10X. The intensity modulation element 32 may be an element using a DMD (Digital Micromirror Device).

The main body 11 further includes a receiving unit 37, a read / write (hereinafter abbreviated as RW (Read Write)) control unit 38, a storage unit 39, and a main control unit 40. The receiving unit 37 receives the ultraviolet UV irradiation profile 41 from the control device 12. The receiving unit 37 outputs the irradiation profile 41 to the RW control unit 38.

The RW control unit 38 stores the irradiation profile 41 in the storage unit 39. Further, the RW control unit 38 reads the irradiation profile 41 from the storage unit 39 and outputs the irradiation profile 41 to the main control unit 40. The RW control unit 38 rewrites the irradiation profile 41 of the storage unit 39 each time a new irradiation profile 41 is received by the receiving unit 37. The storage unit 39 can be paraphrased as a memory or a storage device, for example, a flash memory.

The main control unit 40 controls the overall operation of the main body 11. Specifically, the main control unit 40 operates the light source driver 35 and the intensity modulation element driver 36 according to the irradiation profile 41. The main control unit 40 is a computer equipped with a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory).

In FIG. 7, the computer constituting the control device 12 includes a storage device 50, a memory 51, a CPU 52, a communication unit 53, a display 54, and an input device 55. These are interconnected via a bus line 56.

The storage device 50 is a hard disk drive built in the computer constituting the control device 12 or connected via a cable or a network. The storage device 50 stores control programs such as an operating system, various application programs, and various data associated with these programs. A solid state drive may be used instead of the hard disk drive.

The memory 51 is a work memory for the CPU 52 to execute a process. The CPU 52 comprehensively controls each part of the computer by loading the program stored in the storage device 50 into the memory 51 and executing processing according to the program.

The communication unit 53 is a network interface that controls transmission of various information via a network such as a LAN (Local Area Network). The communication unit 53 is responsible for communication with the main body 11. The display 54 displays various screens. The computer constituting the control device 12 receives input of an operation instruction from the input device 55 through various screens. The input device 55 is a keyboard, a mouse, a touch panel, or the like.

In FIG. 8, the operation program 60 is stored in the storage device 50 of the control device 12. The operation program 60 is an application program for operating the computer as the control device 12. The storage device 50 also stores the irradiation profile 41 and the generation reference information 61.

When the operation program 60 is activated, the CPU 52 of the computer constituting the control device 12 cooperates with the memory 51 and the like to display the display control unit 65, the reception unit 66, the generation unit 67, the RW control unit 68, and the transmission unit. Functions as 69.

The display control unit 65 controls the display of various screens on the display 54. The various screens include a setting screen 80 (see FIG. 9) for setting the design shape information 75 and the like.

The reception unit 66 receives the design shape information 75, the first optical element information 76, the second optical element information 77, and the adhesive information 78 set by the input device 55 through the setting screen 80. The reception unit 66 outputs the design shape information 75, the first optical element information 76, the second optical element information 77, and the adhesive information 78 to the generation unit 67. The design shape information 75 is an example of "set optical characteristics" according to the technique of the present disclosure.

The generation unit 67 generates the irradiation profile 41 from the design shape information 75, the first optical element information 76, the second optical element information 77, and the adhesive information 78 with reference to the generation reference information 61. The generation reference information 61 is a data table, function, and machine learning in which the design shape information 75, the first optical element information 76, the second optical element information 77, and the adhesive information 78 are input data, and the irradiation profile 41 is output data. It is a model etc. The generation unit 67 outputs the irradiation profile 41 to the RW control unit 68.

The RW control unit 68 controls the storage of various data in the storage device 50 and the reading of various data in the storage device 50. For example, the RW control unit 68 reads the generation reference information 61 from the storage device 50 and outputs it to the generation unit 67.

The RW control unit 68 stores the irradiation profile 41 from the generation unit 67 in the storage device 50. Further, the RW control unit 68 reads the irradiation profile 41 from the storage device 50 and outputs the irradiation profile 41 to the transmission unit 69. The transmission unit 69 transmits the irradiation profile 41 to the main body 11.

As shown in FIG. 9, the setting screen 80 has a design shape information input area 81, a first optical element information input area 82, a second optical element information input area 83, and an adhesive information input area 84. The design shape information input area 81 is provided with an input box 85 for a file path representing the design shape information 75, and a reference button 86 for searching the file directory for the file representing the design shape information 75.

In the first optical element information input area 82, a pull-down menu 87 for selectively selecting the lens type of the first optical element 13 and a pull-down menu 87 for selectively selecting the material of the first optical element 13 are provided. A menu 88 is provided. Further, in the first optical element information input area 82, an input box 89 having an outer diameter of the first optical element 13, an input box 90 having a center thickness (denoted as “center thickness” in FIG. 9), and an input of the radius of curvature are input. A box 91 is provided. Similarly, in the second optical element information input area 83, a pull-down menu 92 for selectively selecting the lens type of the second optical element 14 and a pull-down menu 92 for selectively selecting the material of the second optical element 14 are used. A pull-down menu 93, an input box 94 having an outer diameter of the second optical element 14, an input box 95 having a central thickness, and an input box 96 having a radius of curvature are provided. The unit of outer diameter, center thickness, and radius of curvature is mm.

The adhesive information input area 84 is provided with a pull-down menu 97 for selectively selecting the type of the ultraviolet curable resin 21 (denoted as “main component” in FIG. 9) contained in the adhesive 20. .. Further, the adhesive information input area 84 is provided with an input box 98 for the curing shrinkage rate of the adhesive 20 and an input box 99 for the longitudinal elastic modulus of the adhesive 20. The unit of curing shrinkage is%, and the unit of longitudinal elastic modulus is MPa. The thickness of the adhesive 20 may be input as the adhesive information 78.

After completing the selection input in each input area 81 to 84, the user selects the setting button 100. As a result, the design shape information 75, the first optical element information 76, the second optical element information 77, and the adhesive information 78 are received by the reception unit 66.

FIG. 10 shows an example of the junction type optical element 10 and the design shape information 75. In the bonded optical element 10 of this example, in a state of being bonded by the bonding layer 15, the concave surface 13A of the first optical element 13 and the surface facing the concave surface 13A (hereinafter, abbreviated as the facing surface) 13B are rotationally symmetric. It has an aspherical shape. More specifically, the concave surface 13A is deformed so that the end portion is attracted to the second optical element 14 side. With the deformation of the end portion of the concave surface 13A, the facing surface 13B has a shape in which the center has the highest height in the Z direction and the height gradually decreases toward the end portion. The aspherical shape of the first optical element 13 is brought about by the distortion of the bonding layer 15 due to the shrinkage of the adhesive 20. On the other hand, since the second optical element 14 is relatively thick and has a large moment of inertia of area, it retains its shape before being joined by the joining layer 15. The junctional optical element 10 having such an aspherical shape is used, for example, as an aberration correction lens. The design shape information 75 is numerical data representing the aspherical shape of the first optical element 13, such as the height of the facing surface 13B in the Z direction for each XY plane coordinate. In this example, the first optical element 13 corresponds to "at least one of the first optical element and the second optical element" according to the technique of the present disclosure.

In FIG. 11, the irradiation profile 41 has an irradiation profile 41A for the gelation step and an irradiation profile 41B for the main curing step. The irradiation profile 41A for the gelling step is used in the gelling step, and the irradiation profile 41B for the main curing step is used in the main curing step.

The gelling step is shown in FIG. 5B by irradiating the liquid adhesive 20 filled between the first optical element 13 and the second optical element 14 with ultraviolet UV by the filling step shown in FIG. This is a step of gelling the adhesive 20 as described above. The gelling step may be called a temporary curing step in the sense of contrasting with the main curing step. In the gelling step, the curing rate of the adhesive 20 is made different in a plurality of regions by changing the intensity of ultraviolet UV rays by the intensity modulation element 32. In the gelling step, for example, ultraviolet UV having a central wavelength of 365 nm is irradiated.

This curing step is a step of curing the adhesive 20 by irradiating the gelled adhesive 20 through the gelling step with ultraviolet UV. In this curing step, for example, ultraviolet UV having a wavelength of 310 nm to 400 nm is irradiated. The ultraviolet UV is an example of the "first curing stimulus" and the "second curing stimulus of the same type as the first curing stimulus" according to the technique of the present disclosure.

The main curing step is performed without interposing another step between the gelation step and the gelation step. The other step is specifically a heating step.

FIG. 11 illustrates an irradiation profile 41A for the gelling step for two regions, a region R_A having a radius of 48 mm and a region R_B other than the region R_A, of the pre-bonding optical element 10X. That is, for the area R_A, ultraviolet UV illumination to (in FIG. 11 labeled "UV irradiance") and 3 mW / cm ^2, for the area R_B, is set to 0.3 mW / cm ² 1/10 regions R_A. The irradiation time of ultraviolet UV is 90 seconds, which is common to the regions R_A and R_B. That is, the intensity of the first curing stimulus is changed by changing the intensity of the ultraviolet UV. The irradiation profile 41B for this curing step has an illuminance of ultraviolet UV of 5 mW / cm ² and an irradiation time of 30 minutes.

12 and 13 are diagrams showing the state transition of the adhesive 20 at the boundary portion between the region R_A and the region R_B. Further, FIG. 14 is a flowchart showing a procedure of a method for manufacturing the junction type optical element 10. Hereinafter, the operation of the above configuration will be described with reference to FIGS. 12 to 14.

Prior to the manufacture of the junction type optical element 10, the setting screen 80 shown in FIG. 9 is displayed on the display 54 under the control of the display control unit 65 in the control device 12. Then, the design shape information 75, the first optical element information 76, the second optical element information 77, and the adhesive information 78 set by the input device 55 through the setting screen 80 are received by the reception unit 66. These information 75 to 78 are output from the reception unit 66 to the generation unit 67.

In the generation unit 67, the irradiation profile as shown in FIG. 11 is referred to from the design shape information 75, the first optical element information 76, the second optical element information 77, and the adhesive information 78 while referring to the generation reference information 61. 41 is generated. The irradiation profile 41 is transmitted to the main body 11 by the transmission unit 69.

In the main body 11, the irradiation profile 41 from the control device 12 is received by the receiving unit 37. The irradiation profile 41 is stored in the storage unit 39 by the RW control unit 38.

As shown in step ST100, the filling step shown in FIG. 4 is performed, and as shown in FIG. 12A, the liquid adhesive 20 is filled between the first optical element 13 and the second optical element 14. .. The pre-bonding optical element 10X that has completed the filling step is set on the stage 33 of the main body 11.

In the main body 11, the irradiation profile 41 is read from the storage unit 39 by the RW control unit 38. The irradiation profile 41 is output from the RW control unit 38 to the main control unit 40. The main control unit 40 operates the light source 30 via the light source driver 35 according to the irradiation profile 41A for the gelling step in the irradiation profile 41. Further, the main control unit 40 operates the intensity modulation element 32 via the intensity modulation element driver 36 according to the irradiation profile 41A for the gelation step. As a result, the adhesive 20 in the liquid state is irradiated with ultraviolet UV rays corresponding to the irradiation profile 41A for the gelling step, and the gelling step shown in step ST200 is started.

As shown in FIG. 11, the illuminance of ultraviolet UV is lower in the region R_B than in the region R_A. Therefore, as shown in FIG. 12B, the curing rate of the adhesive 20 in the region R_B is slower than the curing rate of the adhesive 20 in the region R_A. Specifically, the polymerization rate of the adhesive 20 in the region R_A is 30%, and the adhesive 20 in the region R_A is gelled, whereas the polymerization rate of the adhesive 20 in the region R_B remains at 10%. .. Region R_A is an example of a "region with a high curing rate" according to the technique of the present disclosure. Further, the region R_B is an example of the “region where the curing rate is slow” according to the technique of the present disclosure. The polymerization rate of the adhesive 20 is exactly the polymerization rate of the monomer 23. Further, here, the time when the polymerization rate is 30% will be described as the gel point of the adhesive 20.

When the ultraviolet UV rays are continuously irradiated, not only the adhesive 20 in the region R_A but also the adhesive 20 in the region R_B gels as shown in FIG. 12C. At this time, the polymerization rate of the adhesive 20 in the region R_A is 50%, and the polymerization rate of the adhesive 20 in the region R_B is 30%. However, the curing rate of the adhesive 20 in the region R_B still remains slower than the curing rate of the adhesive 20 in the region R_A. When the ultraviolet UV is irradiated for a time corresponding to the irradiation profile 41A for the gelling step and the adhesive 20 in the entire region gels, the gelling step shown in step ST200 is completed.

After the gelation step is completed, the main control unit 40 operates the light source 30 via the light source driver 35 according to the irradiation profile 41B for the main curing step of the irradiation profile 41. As a result, the gelled adhesive 20 is irradiated with ultraviolet UV rays corresponding to the irradiation profile 41B for the main curing step, and the main curing step shown in step ST300 is started.

As shown in FIGS. 13A and 13B, in the main curing step, substantially all the monomers 23 are polymerized to a polymerization rate of 100%, and the adhesive 20 shrinks until the main curing step shown in step ST300 is completed. There is a difference in the rate. Specifically, in FIG. 12C, the polymerization rate of the adhesive 20 in the region R_A was 50%, so that the polymerization rate of the adhesive 20 until the end of the main curing step was 50%. On the other hand, in FIG. 12C, since the polymerization rate of the adhesive 20 in the region R_B was 30%, the polymerization rate of the adhesive 20 until the end of the main curing step was 70%. That is, the adhesive 20 in the region R_B shrinks 20% more than the adhesive 20 in the region R_A. As a result, the bonding layer 15 is distorted, and the stress caused by this distortion deforms the first optical element 13. Specifically, the region R_B has a concave shape with respect to the region R_A.

Such distortion of the bonding layer 15 also affects the refractive index. That is, the refractive index of the bonding layer 15 is lower in the region R_A than in the region R_B.

The balance between the strain of the bonding layer 15 and the deformation of the optical element depends on the response to the stress of the adhesive 20 such as the curing shrinkage rate and the longitudinal elastic modulus, and the size such as the thickness of the first optical element 13 and the second optical element 14. It depends on the relationship with the moment of inertia of area. For example, the thickness of the first optical element 13 is very thin, and conversely, the thickness of the second optical element 14 is sufficiently thick, and the second optical element 14 has a cross section sufficient to withstand the stress caused by the distortion of the bonding layer 15. It is assumed that it has the next moment. In this case, the distortion of the bonding layer 15 causes the first optical element 13 to be greatly deformed, but the second optical element 14 is not deformed at all or is only slightly deformed. The first optical element information 76, the second optical element information 77, and the adhesive information 78 are set because it is desired to know the balance between the distortion of the bonding layer 15 and the deformation of the optical element.

As described above, the bonding type optical element 10 includes a first optical element 13, a second optical element 14, and a bonding layer 15. The bonding layer 15 has a strain that deforms the first optical element 13. As described above, since the strain due to the shrinkage deformation of the adhesive 20 is utilized, the optical path difference with respect to the thickness of the bonding layer 15 can be increased as compared with the wave surface avelator described in Japanese Patent Application Laid-Open No. 2009-530689.

The first optical element 13 has an aspherical shape in a state of being joined by the joining layer 15. Therefore, an aspherical lens having high-precision optical characteristics can be obtained. Further, the first optical element 13 has a spherical shape before being joined by the joining layer 15. Therefore, an aspherical lens having high-precision optical characteristics can be obtained from the spherical lens. In the present embodiment, the first optical element 13 has a spherical shape before being joined by the joining layer 15, and has an aspherical shape when joined by the joining layer 15, although it is said that the first optical element 13 has an aspherical shape. The shape of the first optical element in the state of being joined by 15 is not limited to the aspherical shape. For example, the first optical element 13 may have an aspherical shape before being joined by the joining layer 15, and may have a spherical shape when joined by the joining layer 15. Further, in the present embodiment, the first optical element 13 is deformed, but the second optical element 14 may be deformed. Further, both the first optical element 13 and the second optical element 14 may be deformed.

The adhesive 20 contains an ultraviolet curable resin 21 which is a photocurable resin. Therefore, the curing speed of the adhesive 20 in the gelation step can be easily controlled as compared with the thermosetting resin in which it is difficult to change the degree of heating for each region.

The first optical element 13 and the second optical element 14 transmit ultraviolet UV for curing the ultraviolet curable resin 21. Therefore, the ultraviolet curable resin 21 can be reliably cured.

The distortion of the bonding layer 15 is a distortion that deforms the first optical element 13 into a shape according to the set optical characteristics. Therefore, the junction type optical element 10 having the desired optical characteristics can be easily manufactured.

The manufacturing method of the bonded optical element 10 includes a filling step, a gelling step, and a main curing step. In the filling step, the liquid adhesive 20 is filled between the first optical element 13 and the second optical element 14. In the gelling step, the adhesive 20 is gelled by irradiating the liquid adhesive 20 with ultraviolet UV rays. At this time, the curing speed of the adhesive 20 differs in the regions R_A and R_B due to the change in the intensity of the ultraviolet UV. In this curing step, the adhesive 20 is cured by irradiating the adhesive 20 with ultraviolet UV rays. Therefore, it is possible to obtain a junction optical element 10 having high-precision optical characteristics.

The main curing step is performed without interposing another step between the gelation step and the gelation step. Therefore, the manufacturing cost of the junction type optical element 10 can be suppressed. Moreover, the manufacturing time of the junction type optical element 10 can be shortened.

The other process is a heating process. In the heating process, the junction type optical element 10 is set in the heating furnace, the inside of the heating furnace is raised to a set temperature, the junction type optical element 10 is heated at the set temperature for several hours, and the like. Is hung. Therefore, by eliminating the heating step, the manufacturing cost of the bonded optical element 10 can be further suppressed. In addition, the manufacturing time of the junction type optical element 10 can be significantly shortened. The other step may be a step other than the heating step, for example, a cooling step or the like.

In this curing step, the adhesive 20 in the region R_B where the curing speed of the ultraviolet curable resin 21 is slow shrinks more than the adhesive 20 in the region R_A where the curing speed is fast, causing distortion that deforms the first optical element 13. .. Therefore, it is possible to obtain highly accurate optical characteristics as compared with the case where the bonding layer 15 has no distortion.

In the above embodiment, an example in which the concave surface 13A and the facing surface 13B of the first optical element 13 are deformed is given, but the present invention is not limited to this. For example, as in the junction type optical element 110 shown in FIG. 15, the facing surface 13B of the first optical element 13 may be left as it is, and only the concave surface 13A may be deformed. Alternatively, although not shown, the convex surface 14A and / or the surface of the second optical element 14 facing the convex surface 14A may be deformed.

Further, in the above embodiment, the junction type optical element 10 having a rotationally symmetric aspherical shape has been exemplified, but the present invention is not limited to this. Like the bonding optical element 120 shown in FIG. 16, the deformation of the bonding layer 15 due to distortion is biased, and the concave surface 13A and the facing surface 13B (the concave surface 13A is not shown) of the first optical element 13 are non-rotationally symmetric. It may have an aspherical shape. According to the technique of the present disclosure, the bonded optical element 120 having such a non-rotational symmetric aspherical shape can be easily manufactured only by controlling the curing speed of the adhesive 20 for each region.

[Example]
Hereinafter, examples of the junction type optical element will be described. FIG. 17 shows the first optical element information 76, FIG. 18 shows the second optical element information 77, and FIG. 19 shows the adhesive information 78. That is, the first optical element 13 had a lens type of a plano-concave lens, a material of BK7 (registered trademark), an outer diameter of 54 mm, a center thickness of 0.8 mm, and a radius of curvature of −83 mm. The second optical element 14 had a plano-convex lens, a material of BK7 (registered trademark), an outer diameter of 54 mm, a center thickness of 6.5 mm, and a radius of curvature of 83 mm. The main component of the adhesive 20 was polyene / polythiol, the curing shrinkage rate was 6.8%, and the longitudinal elastic modulus was 8.9 MPa. More specifically, the adhesive 20 was manufactured by Denka Co., Ltd. and had a trade name of "Hard Rock OP-1030K". The thickness of the bonding layer 15 was 100 μm.

FIG. 20 shows the irradiation profile 41. In the irradiation profile 41A for the gelling step, the illuminance of the ultraviolet UV in the region R_A having a radius of 34 mm of the pre-bonding optical element 10X is ² mW / cm 2, and the illuminance of the ultraviolet UV in the region R_B other than the region R_A is 0.2 mW / cm ² . there were. The irradiation time of ultraviolet UV was 60 seconds, which was common to the regions R_A and R_B. The irradiation profile 41B for this curing step had an illuminance of ultraviolet rays of 3 mW / cm ² and an irradiation time of 20 minutes.

FIG. 21 shows the amount of deformation of the facing surface 13B of the first optical element 13. It can be seen that the facing surface 13B of the first optical element 13 is certainly deformed due to the shrinkage of the adhesive 20. The peak value of the amount of deformation was 0.907 μm.

FIG. 22 shows the amount of change in the optical path length of the bonding layer 15. It can be seen that the optical path length is certainly changed by the shrinkage of the adhesive 20. The peak value of the amount of change in the optical path length was 0.151 μm. Since the thickness of the bonding layer 15 was 100 μm as described above, the optical path length can be changed by a maximum of 0.151% with respect to the thickness of the bonding layer 15. That is, the optical path difference with respect to the thickness of the bonding layer 15 can be increased.

As described above, according to the technique of the present disclosure, it has been confirmed that a bonded optical element having a desired shape can be manufactured by making the curing speed of the adhesive 20 different in a plurality of regions.

Instead of the design shape information 75, the control device 12 may be made to input the optical characteristics of the junction type optical element 10, and the control device 12 may generate the design shape information 75 according to the input optical characteristics.

The following two methods can be considered as a method for increasing the amount of deformation of the optical element due to the shrinkage of the adhesive 20.
a. An adhesive 20 having a high curing shrinkage rate is used.
b. The thickness of the adhesive 20 is increased.

A. Will be considered below. In the radical polymerization reaction, a radical is added to the double bond of the monomer 23 to change to a single bond. At this time, the van der Waals distance between the monomers 23 is 0.3 nm to 0.6 nm and the double bond is 0.13 nm, whereas the single bond is 0.15 nm. 20 will shrink. Therefore, basically, the smaller the acrylic equivalent per the number of functional groups of the monomer 23, the higher the shrinkage rate tends to be.

For example, the monofunctional isobornyl acrylate has an acrylic equivalent of 208 g / eq and a curing shrinkage rate of 6.8%. On the other hand, the trifunctional trimethylolpropane triacrylate has an acrylic equivalent of 98.7 g / eq and a curing shrinkage rate of 13%. Therefore, in order to increase the amount of deformation of the optical element due to the shrinkage of the adhesive 20, the adhesive 20 containing trimethylolpropane triacrylate as a main component may be used.

The method of making the curing speed of the adhesive 20 in each region different is not limited to the method of changing the illuminance of the ultraviolet rays UV illustrated. The illuminance of the ultraviolet UV may be the same in each region, and the curing speed of the adhesive 20 in each region may be different by changing the irradiation time of the ultraviolet UV in each region.

The intensity modulation element 32 is not limited to the element using the illustrated liquid crystal. A filter having a different ultraviolet UV transmittance depending on each region may be used as the intensity modulation element 32. However, in the case of a filter, only one type of junctional optical element can be manufactured with one filter, but in the case of the intensity modulation element 32 using a liquid crystal, it is possible to manufacture many types of junctional optical elements. can do.

The first optical element 13 and the second optical element 14 are not limited to the combination of the exemplary plano-concave lens and plano-convex lens. A biconvex lens, a biconcave lens, a concave meniscus lens, a convex meniscus lens, a parallel flat plate, a prism, or the like may be used.

The photocurable resin is not limited to the example UV curable resin 21. A visible light curable resin that is cured by irradiation with visible light may be used. Further, the resin is not limited to the photocurable resin. It may be a thermosetting resin. In the case of a thermosetting resin, the first curing stimulus and the second curing stimulus are thermal stimuli.

The regions where the curing speed of the adhesive 20 is different are not limited to the two illustrated regions R_A and R_B. For example, as shown in FIG. 23, the curing rates of the adhesives 20 of the five concentrically divided regions R_A, R_B, R_C, R_D, and R_E may be different.

At least one of the first optical element 13 and the second optical element 14 may have a spherical shape in a state of being bonded by the bonding layer 15.

Although the junction type optical element 10 handled by the main body 11 has been described as one in the present embodiment, a plurality of junction type optical elements 10 may be processed at once. In this way, a plurality of bonded optical elements 10 can be manufactured in the time required to manufacture one bonded optical element 10, and the manufacturing efficiency of the bonded optical element 10 can be improved. Further, the apparatus for performing the gelation step and the apparatus for performing the main curing step may be separated. In this case, a plurality of bonded optical elements 10 that have completed the gelation step in the apparatus that performs the gelation step may be collectively introduced into the apparatus that performs the main curing step, and the main curing step may be performed.

The technique of the present disclosure can be appropriately combined with the various embodiments described above and various modifications. In addition, not limited to each of the above embodiments, it goes without saying that various configurations can be adopted as long as they do not deviate from the gist.

The description and illustration shown above are detailed explanations of the parts related to the technology of the present disclosure, and are merely an example of the technology of the present disclosure. For example, the above description of the configuration, function, action, and effect is an example of the configuration, function, action, and effect of a portion of the art of the present disclosure. Therefore, unnecessary parts may be deleted, new elements may be added, or replacements may be made to the described contents and illustrated contents shown above within a range that does not deviate from the gist of the technique of the present disclosure. Needless to say. In addition, in order to avoid complications and facilitate understanding of the parts relating to the technology of the present disclosure, the above-mentioned description and illustrations require special explanation in order to enable the implementation of the technology of the present disclosure. The explanation about common technical knowledge is omitted.

In the present specification, "A and / or B" is synonymous with "at least one of A and B". That is, "A and / or B" means that it may be A alone, B alone, or a combination of A and B. Further, in the present specification, when three or more matters are connected and expressed by "and / or", the same concept as "A and / or B" is applied.

All documents, patent applications and technical standards described herein are to the same extent as if the individual documents, patent applications and technical standards were specifically and individually stated to be incorporated by reference. Incorporated by reference in the book.

Claims

With the first optical element
With the second optical element
A bonding layer formed of a resin adhesive that joins the first optical element and the second optical element, and is a strain that deforms at least one of the first optical element and the second optical element. With a bonding layer with
A junction type optical element comprising.
The bonded optical element according to claim 1, wherein at least one of the first optical element and the second optical element has an aspherical shape in a state of being bonded by the bonding layer.
The second optical element and the second optical element, wherein the optical element having an aspherical shape in a state of being bonded by the bonding layer has a spherical shape before being bonded by the bonding layer. Junction type optical element.
The junctional optical element according to claim 2 or 3, wherein the aspherical shape is a non-rotationally symmetric shape.
The bonded optical element according to any one of claims 1 to 4, wherein the adhesive contains a photocurable resin.
The junctional optical element according to claim 5, wherein at least one of the first optical element and the second optical element transmits light for curing the photocurable resin.
The distortion is any one of claims 1 to 6, which is a distortion that deforms at least one of the first optical element and the second optical element into a shape corresponding to a set optical characteristic. The junction type optical element described.
A resin adhesive that serves as a bonding layer for joining the first optical element and the second optical element, and is filled with a liquid adhesive between the first optical element and the second optical element. Process and
It is a gelling step of gelling the adhesive by giving a first curing stimulus to the liquid adhesive, and by changing the intensity of the first curing stimulus, the curing rate of the adhesive can be increased. The gelling process, which is different in multiple areas,
The main curing step of curing the adhesive by giving a second curing stimulus to the adhesive, and
A method for manufacturing a bonded optical element.
The method for manufacturing a junctional optical element according to claim 8, wherein the first curing stimulus and the second curing stimulus are the same type.
The method for manufacturing a bonded optical element according to claim 8 or 9, wherein the main curing step is performed without interposing another step between the gelling step and the gelling step.
The method for manufacturing a bonded optical element according to claim 10, wherein the other step is a heating step.
Any of claims 8 to 11 in the main curing step, in which the adhesive in the region having a slow curing rate among the plurality of regions is shrunk more than the adhesive in the region having a high curing rate. The method for manufacturing a junction type optical element according to item 1.
The method for manufacturing a junction type optical element according to claim 12, wherein in the main curing step, distortion that deforms at least one of the first optical element and the second optical element is generated.
The method for manufacturing a bonded optical element according to claim 13, wherein at least one of the first optical element and the second optical element has an aspherical shape in a state of being bonded by the bonding layer.
The 14th aspect of the first optical element and the second optical element, wherein the optical element having an aspherical shape in a state of being bonded by the bonding layer has a spherical shape before being bonded by the bonding layer. Manufacturing method of the junction type optical element.
The method for manufacturing a bonded optical element according to claim 14 or 15, wherein the aspherical shape is a non-rotationally symmetric shape.
The distortion is any one of claims 13 to 16, which is a distortion that deforms at least one of the first optical element and the second optical element into a shape corresponding to a set optical characteristic. The method for manufacturing a junctional optical element according to the description.
The method for manufacturing a bonded optical element according to any one of claims 8 to 17, wherein the adhesive contains a photocurable resin.