JP2006235123A - Lens unit and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens unit in which the effect of heat on the lens is restrained to the utmost and the imaging plastic lens and a holding member for holding the lens are firmly joined. <P>SOLUTION: The lens unit 10 includes the imaging plastic lens and the plastic holding member 2 for holding the peripheral edge of the plastic lens. The lens unit 10 is capable of absorbing at least a laser beam in an interface between the plastic lens 1 and the holding member 2. In the lens unit 10, the plastic lens 1 and the holding member 2 are welded with laser by bringing the peripheral edge 1b and the plastic holding member 2 into contact with each other and then emitting a laser beam to the area where they are in contact with each other. Since, in this method, the effect of heat on the lens is restrained to the utmost, the peripheral edge of the plastic lens and the holding member may be welded (spot welded) at a number of spots in their circumferential direction. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  In the present invention, an imaging (or imaging or imaging system) plastic lens (such as a small camera lens such as a mobile phone camera lens) and a plastic holding member that holds the plastic lens are firmly bonded (or welded). The present invention relates to a lens unit, a manufacturing method thereof, and a device including the lens unit.

  Conventionally, when a lens is attached and fixed to a plastic holding member (or lens barrel), a glass lens is used, and the glass lens and the lens holding portion of the plastic lens barrel are heat caulked. However, such a glass lens has (1) high cost, (2) heavy weight, and (3) lack of freedom in shape (cannot form caulking shapes such as bosses and holes). Due to these disadvantages, the plasticization of lenses has progressed.

  However, since a plastic lens is easily affected by heat, heat caulking is not an appropriate lens holding or fixing method. In order to mitigate the influence of such heat, JP 2002-189160 A (Patent Document 1) forms the outer peripheral surface 12 of the flange 11 of the plastic lens 1 in a slanted or tapered surface with front and rear heights, In addition, the lens support small cylinder 21 is formed in the plastic lens barrel 2 so that the flange 11 is indented and fitted into the lens barrel 2 and the inner peripheral surface 26 of the lens support small cylinder is the minimum of the flange outer peripheral surface 12. Next, the flange 11 is press-fitted into the lens supporting small cylinder 21 and the lens supporting small cylinder 21 is maintained while maintaining the contraction stress generated in the lens supporting small cylinder 21 due to the press-fitting. A method of heat caulking the end of the tube 21 inward is disclosed. Although the thermal caulking method of this document can reduce the influence of heat to some extent, basically when caulking using heat, even if it is a very small part, the resin is deformed by heat, so a certain amount of heat is required. It is necessary and it is very difficult to prevent the heat from affecting the lens.

Further, as another joining method of heat caulking, there is fixing with an adhesive, but there is a drying (reaction) solidification step after application of the adhesive, so that the workability is poor and the yield is also low. In addition, the joining by ultrasonic welding is not appropriate because there is a problem that fine shavings are generated due to vibration during the process and the shavings adhere to the lens.
JP 2002-189160 A (Claim 1)

  Accordingly, an object of the present invention is to provide a lens unit in which a plastic lens for imaging (such as a camera lens for a mobile phone) that requires high accuracy and a holding member for holding the lens are firmly joined, a manufacturing method thereof, The object is to provide a device including a lens unit.

  Another object of the present invention is a lens unit that can be firmly joined to a holding member while suppressing a thermal effect on the lens at a high level, even for a small imaging plastic lens such as a camera lens for a mobile phone, and the like. An object of the present invention is to provide a manufacturing method and an apparatus including the lens unit.

  Still another object of the present invention is to provide a lens unit that can be joined to a holding member with high workability and production efficiency, even a plastic lens for imaging, a manufacturing method thereof, and an apparatus including the lens unit. .

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have found that when an imaging plastic lens and a holding member for holding this lens are joined by laser welding, an imaging plastic lens that requires high accuracy ( In particular, the present invention has found that even a small imaging plastic lens such as a camera lens for a mobile phone can be firmly bonded to a holding member while suppressing a thermal effect that adversely affects optical characteristics and the like at a high level. Was completed.

  That is, the lens unit of the present invention includes an imaging plastic lens and a plastic holding member for holding the outer peripheral edge portion of the plastic lens, and at least a laser beam at an interface portion between the plastic lens and the holding member. Wherein the plastic lens and the holding member are joined by laser light irradiation.

  The plastic lens may be made of a cyclic olefin resin, a methacrylate ester resin, or a polycarbonate resin. The holding member may be made of at least one selected from a cyclic olefin resin, a methacrylic ester resin, a styrene resin, a polyester resin, and a polycarbonate resin. The plastic constituting the holding member may be made of a resin having compatibility with the plastic constituting the plastic lens. For example, the plastic constituting the holding member may be made of the compatible resin for the holding member. It may contain 10% by weight or more of the entire plastic.

  A typical combination of the plastic (1) constituting the plastic lens and the plastic (2) constituting the holding member may be any of the following combinations (i) to (iii).

(I) A combination in which plastic (1) is a cyclic olefin resin and plastic (2) is a resin containing 10% by weight or more of a cyclic olefin resin (ii) Plastic (1) is a methacrylate ester resin And the plastic (2) is a resin comprising at least one selected from a methacrylic ester resin, a styrene resin and a polycarbonate resin containing vinyl cyanide as a polymerization component (iii) plastic (1) is a polycarbonate resin, and the plastic (2) is at least selected from a methacrylic acid ester resin, a styrene resin having vinyl cyanide as a polymerization component, a polyalkylene arylate resin, and a polycarbonate resin. A combination which is a resin containing 10% by weight or more of one kind.

  The plastic constituting the holding member may be made of waste plastic. For example, the plastic constituting the holding member may be made of waste plastic generated by molding a plastic lens. The holding member may contain an inorganic filler in a proportion of 5 to 150 parts by weight with respect to 100 parts by weight of the plastic constituting the holding member.

  The outer peripheral edge of the plastic lens and the holding member may be joined at a plurality of spots in the circumferential direction in order to suppress the influence of laser light as much as possible. The spot width (or laser spot diameter during laser welding) may be about 0.1 to 0.8 mm. The spot and the lens may be separated as much as possible in order to suppress thermal effects and the like. For example, the plastic lens is a plastic lens having a lens main body that can be imaged and a lens outer peripheral edge located around the lens main body, and the width of the lens outer peripheral edge is 0.2 to 5 mm. Yes, the distance between the spot and the lens body may be 0.3 mm or more. Typically, the ratio of the width of the outer periphery of the lens to the width of the lens body is 0.2 to 0.7, the width of the outer periphery of the lens is 0.3 to 2 mm, and The distance from the lens body may be 0.5 mm or more.

  The present invention includes a manufacturing method of the lens unit in which the outer peripheral edge portion of the plastic lens for imaging and the plastic holding member are brought into contact with each other, and the plastic lens and the holding member are joined by irradiating the contact portion with laser light. Moreover, the present invention includes a device including the lens unit.

  In the present invention, a plastic lens for imaging (such as a camera lens for a mobile phone) that requires high accuracy and a holding member for holding the lens can be firmly bonded. In particular, since bonding is performed by laser welding, even a small imaging lens such as a camera lens for a mobile phone can be firmly bonded to the holding member while suppressing the thermal effect on the lens at a high level. Moreover, since it can join by laser welding (further, spot welding), even a plastic lens for imaging can be joined to the holding member with high workability and production efficiency. Therefore, in the present invention, not only the adverse effects on the lens due to heat, such as thermal caulking, adhesives, ultrasonic welding, etc., degradation of optical properties (decrease in lens function), yield, etc. are small, The imaging lens and the holding member can be joined while maintaining the optical characteristics of the lens over a long period of time without the problem of dust such as scraps.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings as necessary.

  FIG. 1A is a schematic cross-sectional view showing an example of the lens unit of the present invention, and FIG. 1B is a plan view of the lens unit shown in FIG. 1A. In FIG. 1A, a lens unit 10 includes a spherical plastic lens 1 for imaging, and a hollow cylindrical holding member (or barrel) 2 for holding (mounting) the plastic lens 1. The plastic lens 1 is joined (welded) at the contact surface between the outer peripheral edge 1b of the plastic lens 1 and the holding member 2. In other words, the plastic lens 1 is composed of a spherical body-shaped lens main body 1a that can be imaged and an outer peripheral edge 1b that is located around the lens main body 1a, and holds or supports the outer peripheral edge 1b. The upper end surface of the holding member 2 for holding the lens 1 is held in surface contact with the outer peripheral edge 1b. Specifically, the upper end surface of the opening of the holding member 2 is in surface contact with the outer peripheral edge 1b, and holds the plastic lens 1 without being in contact with the lens body 1a.

  The plastic lens 1 that can transmit laser light (laser-transmitting plastic lens) and the holding member 2 that can absorb laser light (laser-absorbing holding member) are exposed to the outside of the plastic lens 1 by laser light irradiation. Among the contact surfaces of the peripheral edge portion 1b and the holding member 2, bonding is performed at spots (spot welded portions) 3 at a plurality of locations in the circumferential direction (three locations at almost equal intervals in the example of FIG. 1B). The spot 3 is located at an interface relatively far from the lens body 1a in the contact interface between the lens 1 and the holding member 2 in order to reduce the influence of the laser light irradiation on the lens.

  2A is a schematic sectional view showing another example of the lens unit of the present invention, and FIG. 2B is a plan view of the lens unit shown in FIG. 2A. The lens unit 20 of this example includes an imaging lens 11 having the same structure as the lens 1 and a hollow cylindrical holding member (or lens barrel) 12 for mounting and holding the imaging lens 11. I have. That is, the inner peripheral portion of the upper end surface of the holding member 12 holds (places) the outer peripheral edge portion 11b of the imaging plastic lens 11 composed of the lens main body portion 11a and the outer peripheral edge portion 11b, An annular notch step (or mounting step portion) is formed to support and fix the outer peripheral edge portion 11b in the circumferential direction of the lens, and this notch step portion (or mounting step portion) is mounted. The placement surface 12a and at least the bottom surface (in this example, the side end surface and the bottom surface) of the outer peripheral edge portion 11b are in surface contact.

[Plastic lens]
The shape of the plastic lens is not particularly limited as long as it is a shape that can be held by a holding member, and is non-convex (for example, an aspheric surface such as a flat plate), convex (both surfaces are convex, one surface is convex) And the other surface may be a concave surface shape) or the like, and may generally be a spherical body shape (or a spherical surface shape, for example, a spherical body shape having both convex surfaces). In addition, the cross-sectional shape (cross-sectional shape perpendicular to the optical axis) of the plastic lens may be a polygonal shape (for example, a triangular shape or a quadrangular shape), and is usually a circular shape or an elliptical shape. Also good.

  Further, the outer peripheral edge held by the holding member may be an outer peripheral edge of the plastic lens, and may be an outer peripheral edge having a lens function (that is, an outer peripheral edge of the lens functional part), In order to minimize the influence of heat on a portion having a substantial lens function, the outer peripheral portion (or outer periphery) has substantially no lens function (imaging function, imaging system lens function) (or does not participate in imaging). (Attachment part). The shape of the outer peripheral edge may be any shape as long as it can be held by the holding member, and may be a flat shape as shown in FIGS. 1A and 2A. The shape of the holding member (specifically, the portion in contact with the holding member) Depending on the shape, it may be convex or concave. The end of the lens (end of the outer peripheral edge) may have a cut surface that is cut in a direction parallel to the optical axis of the lens, and can contact the holding member on such a cut surface. It may be.

  The plastic lens may have a single layer structure or a laminated structure. For example, the plastic lens may be a laminated body of an aspherical lens (aspherical layer) and a spherical lens (spherical layer).

  The thickness (or maximum thickness, thickness d1 in FIG. 1A, thickness d2 in FIG. 2A) and width (or diameter, corresponding to width e1 + 2 × g1 in FIG. 1A and width e2 + 2 × g2 in FIG. 2A) of the plastic lens depend on the application. Can be selected as appropriate. For example, in a small imaging lens such as a small camera lens (for example, a camera lens for a mobile phone), the thickness is 0.1 to 20 mm, preferably 0.3 to 10 mm, more preferably 0.5 to 5 mm. In particular, it may be about 1 to 3 mm (for example, 1.5 to 2.5 mm), and the width is 1 to 30 mm, preferably 1.5 to 20 mm, more preferably 2 to 15 mm (for example, 2.5 to 12 mm). ), Especially 10 mm or less [for example, about 3 to 10 mm (for example, about 3 to 7 mm)].

  When the plastic lens is composed of a lens body that can be imaged and an outer peripheral edge that is not substantially involved in imaging, the thickness of the lens body in a small imaging lens is in the same range as above. The width (e1 in FIG. 1A, corresponding to e2 in FIG. 2A) is 0.5 to 20 mm, preferably 1 to 15 mm, more preferably 1.5 to 10 mm (for example, 1.8 to 8 mm), especially about 2 to 5 mm (for example, 2.5 to 4 mm).

  Further, the thickness (or the maximum thickness, corresponding to the thickness f1 in FIG. 1A and the thickness f2 in FIG. 2A) and the width (corresponding to the width g1 in FIG. 1A and the width g2 in FIG. You can choose. For example, in a small imaging lens, the thickness is the same as or smaller than that of a plastic lens, for example, 0.1 to 20 mm, preferably 0.2 to 8 mm (for example, 0.3 to 5 mm), and more preferably. It may be about 0.5 to 3 mm, particularly about 0.6 to 2 mm (for example, 0.8 to 1.5 mm), and the width is 0.1 to 10 mm, preferably 0.15 to 8 mm, and more preferably 0. It may be about 2 to 5 mm (for example, 0.25 to 3 mm), particularly about 0.3 to 2 mm (for example, 0.5 to 1.8 mm). In the present invention, the outer peripheral edge portion and the holding member can be firmly bonded to each other while suppressing the thermal influence on the lens by laser welding (particularly spot welding) even with the outer peripheral edge portion having a narrow width as described above.

  In a plastic lens, the ratio of the width of the lens outer peripheral edge to the width (or diameter) of the portion excluding the outer peripheral edge (usually the lens body) (corresponding to f1 / e1 in FIG. 1A and f2 / e2 in FIG. 2A). May be, for example, about 0.1 to 1, preferably about 0.15 to 0.8, and more preferably about 0.2 to 0.7 (for example, 0.25 to 0.6).

  Note that at least one surface of the plastic lens may be subjected to various processing treatments, for example, hard coat treatment, antireflection treatment, antifogging treatment, antifouling treatment, mirror processing treatment, and the like. It may be processed in combination of the above processing.

(Plastic for lenses)
The plastic constituting the plastic lens (hereinafter sometimes referred to as plastic (1), plastic for lens, etc.) is not particularly limited as long as it can be used for imaging (or for photographing). Resin (methacrylic ester resin, etc.), styrene resin [for example, acrylonitrile-styrene copolymer, methyl methacrylate-styrene copolymer, methyl methacrylate-modified acrylonitrile-butadiene-styrene copolymer (transparent ABS resin), etc. ], Polycarbonate resins, polyamide resins (such as alicyclic polyamide resins), polyester resins (homo or copolyesters having an aromatic arylate unit, or aromatic polyester resins), and the like. The plastic for lenses may be a thermoplastic resin or a thermosetting (or photocurable) resin. These resins may be used alone or in combination of two or more.

  Of these plastics for lenses, an olefin resin, a methacrylic ester resin, or a polycarbonate resin can be suitably used from the viewpoint of optical properties and the like.

(Olefin resin)
Examples of the olefin resins include chain olefin resins [for example, methylpentene resins [for example, methylpentene homopolymers or copolymers such as poly (4-methylpentene-1), methylpentene and olefin monomers ( For example, copolymers with α-C _2-20 olefins such as ethylene and propylene, preferably α-C _2-6 olefins), etc.], and cyclic olefin resins. The olefinic resins may be used alone or in combination of two or more. A preferred olefin resin is a cyclic olefin resin.

The cyclic olefin resin may be a resin having at least a cyclic olefin as a polymerization component. The cyclic olefin may be a monocyclic olefin or a polycyclic olefin. In addition, the cyclic olefin includes a substituent {eg, a hydrocarbon group [eg, an alkyl group (eg, a C _1-10 alkyl group such as a methyl group, preferably a C _1-5 alkyl group), a cycloalkyl group (eg, cyclohexyl C _5-10 cycloalkyl group such as a group), aryl group (eg, C _6-10 aryl group such as phenyl group), alkenyl group (eg, C _2-10 alkenyl group such as propenyl group), cycloalkenyl group (For example, C _5-10 cycloalkenyl group such as cyclopentenyl group, cyclohexenyl group, etc.), alkylidene group (for example, C _2-10 alkylidene group such as ethylidene group, preferably C _2-5 alkylidene group, etc.)] , an alkoxy group (e.g., C _1-10 alkoxy group such as methoxy group, preferably a C _1-6 alkoxy group), an acyl group (e.g., such as an acetyl group _2-5 an acyl group), an alkoxycarbonyl group (e.g., C _1-10 alkoxy, such as methoxy carbonyl group - carbonyl group), a hydroxyl group, a carboxyl group, an amino group, a substituted amino group, a halogen atom, a haloalkyl group, a nitro group , A cyano group, an oxo group (═O), a heterocyclic group (such as a nitrogen atom-containing heterocyclic group such as a pyridyl group), and the like}. The cyclic olefin may have a substituent alone or in combination of two or more.

Specific cyclic olefins include monocyclic olefins [eg, cycloalkenes (eg, cycloC _3-10 alkenes such as cyclobutene, cyclopentene, cycloheptene, cyclooctene, etc.), cycloalkadienes (eg, cyclopentadiene, etc. cyclo C _3-10 alkadiene), etc.]; bicyclic olefins {e.g., bicycloalkene [e.g., norbornene (such as 2-norbornene, 5-methyl-2-norbornene, 5,5 or 5,6-dimethyl 2-norbornene, 5-ethylidene-2-norbornene, 5-cyano-2-norbornene, 5-methoxycarbonyl-2-norbornene, 5-phenyl-2-norbornene, 5-methyl-5-methoxycarbonyl-2-norbornene 5,6-dimethoxycarbonyl-2-no C _4-20 bicycloalkenes such as rubornene, 5,6-di (trifluoromethyl) -2-norbornene, 7-oxo-2-norbornene, etc.], bicycloalkadienes [eg, norbornadienes (eg 2, 5-norbornadiene, 5-methyl-2,5-norbornadiene, 5-cyano-2,5-norbornadiene, 5-methoxycarbonyl-2,5-norbornadiene, 5-phenyl-2,5-norbornadiene, 5,6-dimethyl -2,5-norbornadiene, 5,6-di (trifluoromethyl) -2,5-norbornadiene, 7-oxo-2-norbornadiene, etc.)], etc.], tricyclic olefins {eg tricycloalkenes [eg , Dihydrodicyclopentadiene (such as dihydrodicyclopentadiene) _6-25 tricycloalkenes etc.], tri cycloalkadiene [e.g., a dicyclopentadiene compound (dicyclopentadiene, methyl dicyclopentadiene, etc.), tricyclo [4.4.0.1 ^{2, 5]} undec-3,7 - diene, tricyclo [4.4.0.1 ^{2, 5]} such as C _6-25 tricycloalkyl alkadiene such undec-3,8-diene], etc.}, tetracyclic or more polycyclic olefins {e.g., four cyclic olefins [e.g., tetra cycloalkenes (e.g., tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene, 8-methyl tetracyclo [4.4.0.1 ^{2, 5.1 7,10]} -3-dodecene, 8,9-dimethyl-tetracyclo ^{[4.4.0.1 2,5 .1 7,10] -3- C} 8-30 tetra cycloalkene such as dodecene, etc. ), Etc.], pentacyclic olefins [eg pens Cycloalkadienes (e.g., tri C _10-35 penta cycloalkadiene such as cyclopentadiene), etc.], six cyclic olefins [e.g., hexa cycloalkenes (e.g., hexacyclo [6.6.1.1 ^{3, 6.} 0 ^2,7 . 0 ^9,14] -4- C _12-40 hexa cycloalkene), etc., such as heptadecene] and the like polycyclic olefins such as such}.

The cyclic olefin-based resin may be a cyclic olefin homopolymer or a copolymer (for example, a copolymer of a monocyclic olefin and a polycyclic olefin), and a cyclic olefin and a copolymerizable monomer. A copolymer may also be used. The copolymerizable monomer is not particularly limited as long as it can be copolymerized, but it is a chain olefin [alkene (for example, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene). 2-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1 C ₂ such as -pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicocene _-20 alkenes), alkadienes (e.g., 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 1,7-a-octadiene Nonconjugated C _5-20 alkadiene), etc.], a polymerizable nitrile compound (e.g., (meth) acrylonitrile, etc.), (meth) acrylic monomer (e.g., (meth) acrylate, ethyl (meth) acrylate (Meth) acrylic acid esters such as (meth) acrylic acid), unsaturated dicarboxylic acids or derivatives thereof (maleic anhydride, etc.), and the like. The copolymerizable monomers may be used alone or in combination of two or more.

  Preferred cyclic olefin-based resins include resins containing polycyclic olefins (for example, bi to hexacyclic olefins) as polymerization components, particularly, norbornene monomers (or norbornene skeletons among polycyclic olefins). Examples thereof include resins containing a monomer, for example, the norbornenes and the dicyclopentadiene) as a polymerization component. The cyclic olefin-based resins may be used alone or in combination of two or more.

  The cyclic olefin-based resin may be a resin obtained by addition polymerization, or may be a resin obtained by ring-opening polymerization (such as ring-opening metathesis polymerization). In addition, the cyclic olefin-based resin (for example, a resin obtained by ring-opening metathesis polymerization) may be a hydrogenated hydrogenated resin. In addition, the cyclic olefin resin may be a crystalline or amorphous resin, and may usually be an amorphous resin.

  The resin having a polycyclic olefin as a polymerization component may be a polycyclic olefin homopolymer or copolymer, and a copolymer having a polycyclic olefin as a polymerization component (polycyclic olefin and copolymerizable monomer). A copolymer with a monomer). In a copolymer having a polycyclic olefin as a polymerization component, the ratio of the polycyclic olefin (such as a norbornene monomer) is the entire monomer [polycyclic olefin and copolymerizable monomer (for example, ethylene 30% by weight or more (for example, about 35 to 99.5% by weight), preferably 40% by weight or more (for example, about 45 to 99% by weight), more preferably It may be 50% by weight or more (for example, about 55 to 98% by weight), particularly 60% by weight or more (for example, about 65 to 95% by weight).

  The cyclic olefin-based resin may be prepared by a conventional polymerization method (for example, addition polymerization using a Ziegler-type catalyst, ring-opening metathesis polymerization using a metathesis polymerization catalyst, etc.), or a commercially available product may be used. Good. For example, the cyclic olefin-based resin can be obtained from Nippon Zeon Co., Ltd. under the trade name “ZEONEX”, from JSR Co., Ltd. under the trade name “ARTON”, from Mitsui Chemicals, Inc. under the trade name “Apel”, and the like.

  The Abbe number of the olefin resin (cyclic olefin resin) can usually be selected from the range of 40 or more (for example, about 42 to 70), for example, 45 or more (for example, about 48 to 65), preferably 50 or more ( For example, it may be about 52 to 63), more preferably 53 or more (for example, about 54 to 62), particularly about 55 to 60.

(Methacrylic ester resin)
The methacrylic acid ester-based resin is a resin obtained by using at least a methacrylic acid ester as a polymerization component. From the viewpoint of lens characteristics, usually, at least a methacrylic acid alkyl ester [for example, a methacrylic acid alkyl ester (methyl methacrylate, methyl methacrylate, Methacrylic acid C _1-20 alkyl esters such as ethyl, propyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, preferably C _1-8 alkyl esters of methacrylic acid, more preferably C _1-4 alkyl esters of methacrylic acid, especially In many cases, it is a resin having a polymerization component such as methyl methacrylate). Methacrylic acid alkyl esters may be used alone or in combination of two or more.

  The methacrylic ester resin may be, for example, a homopolymer or copolymer of an alkyl methacrylate (particularly methyl methacrylate), and a copolymerizable monomer with an alkyl methacrylate (particularly methyl methacrylate). It may be a copolymer with (polymerizable polymerizable unsaturated monomer).

The copolymerizable monomer is not particularly limited as long as it can be copolymerized. For example, (meth) acrylic acid (meaning acrylic acid or methacrylic acid; hereinafter the same), alkyl acrylate (for example, methyl acrylate) Acrylic acid C _1-10 alkyl ester such as ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate), (meth) acrylic acid ester having alicyclic hydrocarbon group [for example, (meth) (Meth) acrylic acid C _5-10 cycloalkyl esters such as cyclohexyl acrylate; bi to tetracycloalkyl (meta) such as decalinyl (meth) acrylate, norbornyl (meth) acrylate, bornyl (meth) acrylate, and adamantyl (meth) acrylate ) Acrylates, etc.], (meth) acrylic acid Lucenyl ester [eg, allyl (meth) acrylate, etc.], (meth) acrylic acid hydroxyalkyl ester [eg, (meth) acrylic acid hydroxy C _2-6 alkyl ester such as hydroxyethyl (meth) acrylate, etc.], Glycidyl (meth) acrylate, polyfunctional (meth) acrylate [for example, alkanediol di (meth) acrylate (ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, neo Pentyl glycol di (meth) acrylate), alkanetriol di to tri (meth) acrylate (trimethylolethane tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, etc.), alkanetetra Poly (meth) acrylates such as polyols such as all di to tetra (meth) acrylates (pentaerythritol tetra (meth) acrylates), alkylene oxides of polyols (eg C _2-4 alkylene oxides such as ethylene oxide) adducts (Meth) acrylic monomers such as acrylates, etc .; (meth) acrylonitrile; styrene monomers (such as styrene); vinyl ester monomers (such as vinyl acetate); unsaturated carboxylic acids or anhydrides thereof ( And maleic anhydride, maleic acid, fumaric acid, etc.). The copolymerizable monomer may usually be a (meth) acrylic monomer.

  The copolymerizable monomers may be used alone or in combination of two or more.

Preferred methacrylic ester resins are resins having methyl methacrylate as a polymerization component (or main component), for example, polymethyl methacrylate, copolymers having methyl methacrylate as a polymerization component [for example, methyl methacrylate and methacrylic acid. And a copolymer with an alkyl ester (for example, methyl methacrylate-methacrylic acid C _2-8 alkyl ester copolymer, etc.). In such a copolymer having methyl methacrylate as a polymerization component, the proportion of methyl methacrylate is determined based on the whole monomer [methyl methacrylate and other monomers (methacrylic acid C _2-8 alkyl ester, the copolymer , Etc.)] is preferably 50% by weight or more (for example, about 55 to 99.9% by weight), preferably 60% by weight or more (for example, about 65 to 99% by weight), and more preferably 70% by weight or more ( For example, it may be about 75 to 95% by weight.

  Methacrylic ester resins may be used alone or in combination of two or more.

  In addition, the methacrylic ester resin can be used as it is for the formation (or production or preparation) of a lens by using a methacrylic ester resin produced by a typical polymerization method (suspension polymerization, emulsion polymerization, solution polymerization, etc.). Alternatively, the lens may be formed by polymerizing (or curing) syrup (acrylic syrup, syrup-like methacrylic ester resin) containing the monomer as described above. Such a syrup can be prepared by a conventional method, for example, a method of obtaining a partial polymer (polymer) by bulk prepolymerization, a method of dissolving the polymer in a monomer, etc. The polymer content is preferably adjusted to 35% by weight or less (for example, about 1 to 30% by weight, preferably about 3 to 20% by weight) of the entire syrup.

  The Abbe number of the methacrylate ester resin is, for example, 45 or more (for example, about 48 to 65), preferably 50 or more (for example, about 52 to 64), more preferably 53 or more (for example, about 55 to 62), In particular, it may be about 56 to 61.

(Polycarbonate resin)
Examples of polycarbonate resins include polycarbonate resins (aromatic polycarbonate) obtained by reacting dihydric phenols such as bisphenols (such as bisphenol A) and carbonate precursors (carbonate forming compounds), diethylene glycol bisallyl carbonate, etc. Aliphatic polycarbonates containing aliphatic carbonates as polymerization components.

Examples of bisphenols include bis (hydroxyphenyl) alkanes [eg, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) Propane (bisphenol A), 2,2-bis (4-hydroxy-3-methylphenyl) propane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (3 Bis (hydroxyphenyl) C _1-4 alkanes such as 5-dibromo-4-hydroxyphenyl) propane], bis (hydroxyphenyl) cycloalkanes [for example, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1 , 1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane (Hydroxyphenyl) C _5-8 cycloalkane and the like], bis (hydroxyphenyl) sulfones [for example, bis (4-hydroxyphenyl) sulfone, 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfone, etc.], Bis (hydroxyphenyl) sulfides [for example, bis (4-hydroxyphenyl) sulfide, etc.], bis (hydroxyphenyl-alkyl) arenes [for example, 4,4 ′-(m-phenylenediisopropylidene) diphenol, etc. Bis (hydroxyphenyl-C _1-4 alkyl) benzene] and the like. Bisphenols may be used alone or in combination of two or more.

Examples of the carbonate precursor include carbonates [e.g., diaryl carbonate (e.g., diphenyl carbonate), dialkyl carbonates (e.g., dimethyl carbonate, diethyl carbonate), etc.], carbonyl halides [e.g., phosgenes (phosgene, diphosgene, Triphosgene and the like], haloformates [e.g. non-aromatic bishaloformates (ethylene glycol bischloroformate, 1,4-butanediol bischloroformate, 1,6-hexanediol bischloroformate, etc. _2-10 alkanediol bishaloformate diethylene glycol bischloroformate, triethylene glycol bischloroformate such as poly C _2-4 alkanediol bishaloformate such , Aromatic bishaloformates (for example, dihydroxyarene bishaloformates such as hydroquinone bischloroformate and resorcinol bischloroformate; bishaloformates of bisphenols such as bisphenol A-bischloroformate), etc.] Is mentioned. You may use a carbonate precursor individually or in combination of 2 or more types.

  The Abbe number of the polycarbonate resin is, for example, 40 or less (for example, about 20 to 38), preferably 36 or less (for example, about 23 to 35), more preferably 34 or less (for example, about 25 to 33), particularly 26. It may be about ~ 32.

  Among these plastics for lenses, it is preferable that the plastic for lenses is composed of a cyclic olefin resin, a methacrylic ester resin, and a polycarbonate resin, and it is particularly preferable that the plastic for lenses is composed of a cyclic olefin resin. In the lens plastic composed of such a cyclic olefin resin, the ratio of the cyclic olefin resin is, for example, 50% by weight or more (for example, about 55 to 100% by weight), preferably 60% by weight of the whole lens plastic. % Or more (for example, about 65 to 100% by weight), more preferably 70% by weight or more (for example, about 75 to 100% by weight).

  The number average molecular weight of the plastic (1) may be, for example, 3,000 to 300,000, preferably 5,000 to 200,000, and more preferably about 10,000 to 100,000.

  Plastic (1) contains various additives such as stabilizers (thermal stabilizers, UV absorbers, antioxidants, etc.), plasticizers, lubricants, fillers, colorants, flame retardants, antistatic agents, and the like. You may go out. The plastic for lenses may contain these additives alone or in combination of two or more.

  Although the refractive index of the plastic for lenses depends on the type of resin, it is, for example, 1.4 or more, preferably 1.45 or more (for example, 1.46 to 1.7), more preferably 1.48 or more (for example, , 1.49 to 1.65), particularly about 1.5 or more (for example, 1.51 to 1.6).

  The total light transmittance of the lens plastic (or plastic lens) is, for example, 80% or more (for example, about 83 to 99%), preferably 85% or more (for example, about 86 to 98%), and more preferably. It may be 88% or more (for example, about 90 to 95%).

  The heat distortion temperature of the lens plastic may be, for example, about 70 to 200 ° C, preferably about 80 to 180 ° C, and more preferably about 90 to 170 ° C.

  The plastic lens can be formed by a conventional molding method such as a compression molding method, a transfer molding method, an extrusion molding method, an injection molding method, etc., and by an injection molding method (including an insert injection molding method and an injection compression molding method). Often molded.

  The plastic lens is usually laser transmissive. However, as will be described later, a laser-absorbing coating is formed on at least the contact portion (outer peripheral edge portion) of the plastic lens with the plastic holding member. Also good.

[Plastic holding member]
The holding member should just be a member (hollow holding member, cylindrical holding member) which has a hollow part in the optical axis direction of a lens, and can hold | maintain at least the said outer periphery part. The cross-sectional shape of the hollow portion corresponds to the shape of the lens (usually the lens main body portion), and may be a polygonal shape (for example, a triangular shape or a quadrangular shape). There may be.

  The diameter of the holding member (e1 + 2 × g1 in FIG. 1A, corresponding to e2 + 2 × g2 + 2 × (h2−k2) in FIG. 2A) corresponds to the width of the lens, for example, 1 to 30 mm, preferably 1.5. It may be about 20 mm, more preferably 2 to 15 mm (for example, 2.5 to 12 mm), particularly about 3 to 10 mm (for example, 3 to 7 mm).

  Further, the width of the holding member (the width or thickness of the non-hollow portion, corresponding to g1 in FIG. 1A and h2 in FIG. 2A) can be appropriately selected according to the width of the plastic lens (or outer peripheral edge portion). In a small imaging lens, for example, 0.1 to 30 mm, preferably 0.15 to 10 mm, more preferably 0.2 to 5 mm (for example, 0.25 to 3 mm), particularly 0.3 to 2 mm (for example, It may be about 0.5 to 1.8 mm). In addition, when providing a notch step part (or mounting step part) in a holding member, the height of a notch step part can be suitably adjusted according to the height of an outer peripheral edge part, etc.

  In addition, on the upper end surface of the holding member that can contact the outer peripheral edge of the plastic lens, in order to promote heat radiation from the welded portion [in the example of the figure, spot-like welded portion (spot welded portion)] A notch recess (for example, a recess or groove extending in the radial direction and communicating with the hollow portion of the cylindrical holding member) may be formed in the circumferential direction.

  Furthermore, a notch step (or mounting step) for mounting or holding the outer peripheral edge of the plastic lens is formed in the inner peripheral area of the upper end surface of the holding member, and this notch step (or mounting) In the circumferential direction of the stepped portion, in order to promote heat dissipation from the spot welded portion, a notch recess (for example, a recess or groove extending in the radial direction and communicating with the hollow portion of the holding member) is adjacent to the spot welded portion. It may be formed.

(Plastic for holding member)
The holding member only needs to be formed (or configured) from plastic, and the plastic constituting the holding member (hereinafter, sometimes referred to as plastic (2), plastic for holding member) is particularly limited. For example, polyamide resins (polyamide 6, polyamide 66, polyamide 12, polyamide 612, polyamide 6/66 and other aliphatic polyamide resins; polyamide 6T and other aromatic polyamide resins; alicyclic polyamide resins, etc.) , Polyester resins (polyalkylene arylate resins, etc.), polycarbonate resins, olefin resins [single or copolymer of chain olefins such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-propylene rubber (including elastomers) , Annular me Resin, etc.], styrene resin, acrylic resin (for example, methacrylate ester resin, etc.), vinyl resin (vinyl chloride resin, vinyl acetate resin, ethylene-vinyl acetate copolymer, polyvinyl alcohol, Ethylene-vinyl alcohol copolymer, etc.), polyphenylene oxide resins [polyphenylene oxide, modified polyphenylene oxide (blends with polystyrene, polyphenylene oxide grafted with polystyrene, etc.), etc.]. The holding member plastic may be a thermoplastic resin or a thermosetting (or photo-curing) resin, and may usually be a thermoplastic resin. The holding member plastic may be a crystalline resin or an amorphous resin. The holding member plastics may be used alone or in combination of two or more.

  Among these, from the viewpoint of weldability (or compatibility) to the lens plastic, the holding member plastic is an olefin resin (particularly, a cyclic olefin resin such as the above-mentioned cyclic olefin resin), a methacrylate ester type. It is preferably composed of at least one selected from a resin (such as the above-mentioned methacrylic acid ester-based resin), a styrene-based resin, a polyester-based resin, and a polycarbonate-based resin (the illustrated polycarbonate-based resin).

  Examples of the styrene resin include resins containing aromatic vinyl monomers (for example, styrene, α-methylstyrene, β-methylstyrene, and combinations thereof) such as polystyrene and high-impact polystyrene ( HIPS), methyl methacrylate modified HIPS (transparent HIPS), styrene-methyl methacrylate copolymer, styrene- (meth) acrylic acid copolymer, styrene-acrylonitrile copolymer (AS resin), styrene containing rubber component Resin [styrene-acrylonitrile-butadiene copolymer (ABS resin), methyl methacrylate-modified ABS resin (transparent ABS resin), α-methylstyrene-modified ABS resin, imide-modified ABS resin, styrene-methyl methacrylate-butadiene copolymer Diene rubber such as coalesced (MBS resin) (poly Tajien, styrene resins including styrene-butadiene copolymer rubber); AXS resins, methyl methacrylate-modified AXS resin], and the like. Here, the AXS resin refers to a resin obtained by graft polymerization of acrylonitrile A and styrene S to rubber component X (acrylic rubber, chlorinated polyethylene, ethylene-propylene rubber, ethylene-vinyl acetate copolymer, etc.). These include acrylonitrile-acrylic rubber-styrene resin (AAS resin), acrylonitrile-ethylene-propylene rubber-styrene resin (AES resin), and the like. Note that the rubber-containing styrene-based resin contains at least an aromatic vinyl monomer (and, if necessary, an acrylic monomer and / or a vinyl cyanide-based monomer in the presence of a rubber component (such as a diene rubber). In many cases, it is a graft copolymer obtained by graft copolymerization of a monomer, other copolymerizable monomers, and the like. These styrenic resins can be used alone or in combination of two or more.

  Among these styrene resins, preferable styrene resins include, for example, styrene-methyl methacrylate copolymer, styrene- (meth) acrylic acid copolymer, AS resin, ABS resin, AAS resin, AES resin, MBS. Polymerization component of acrylic monomer such as resin, methacrylic acid-modified AAS resin [(meth) acrylic acid ester such as (meth) acrylic acid, methyl methacrylate] and / or vinyl cyanide monomer (acrylonitrile, etc.) Styrene resins (acrylic-modified styrene resins, acrylic-containing styrene resins), especially styrene resins containing vinyl cyanide as a polymerization component [for example, ABS resins (ABS resin, ABS resin and AS resin) Diene rubber-containing styrenic resin containing vinyl cyanide as a polymerization component] Masui.

  In the acrylic-modified styrene resin, the ratio of the aromatic vinyl monomer to the acrylic monomer and / or vinyl cyanide monomer is the former / the latter (weight ratio) = 20/80 to 95 / 5, preferably 30/70 to 90/10, more preferably about 55/45 to 85/15. Further, in the acrylic-modified styrene resin containing rubber (diene rubber, etc.), the ratio of the diene rubber is the ratio between the aromatic vinyl monomer and the acrylic monomer and / or vinyl cyanide monomer. For example, it may be about 10 to 250 parts by weight, preferably 20 to 200 parts by weight, and more preferably about 30 to 150 parts by weight with respect to the total amount of 100 parts by weight. In addition, the acrylic-modified styrene resin may be a resin having other copolymerizable monomer as a polymerization component, and the ratio of the other copolymerizable monomer is 0 to 30% by weight of the whole monomer constituting the resin. % May be sufficient.

  In addition, when mixing ABS resin and AS resin, the ratio of ABS resin and AS resin is the former / the latter (weight ratio) = 99/1 to 10/90, preferably 95/5 to 20/80, Preferably it may be about 90/10 to 30/70, particularly preferably about 80/20 to 40/60.

  Examples of the polyester resin include aromatic polyester resins and aliphatic polyester resins. As the polyester resin, an aromatic polyester resin (for example, a polyalkylene arylate resin) is usually used.

Aromatic polyester-based resins include, for example, aromatic dicarboxylic acid components [for example, aromatic dicarboxylic acids having about 8 to 14 carbon atoms such as phthalic acid, terephthalic acid, naphthalenedicarboxylic acid, and esters thereof (for example, dimethyl terephthalate). C _1-3 alkyl ester, etc.] and diol component [aliphatic diol (for example, ethylene glycol, trimethylene glycol, propylene glycol, 1,4-butanediol, etc., about 2 to 12 carbon atoms) A saturated aliphatic glycol, etc.) and an alicyclic diol (eg, 1,4-cyclohexanedimethanol, etc.)]. The aromatic dicarboxylic acid component and the diol component can be used alone or in combination of two or more. In addition to aromatic dicarboxylic acids, dicarboxylic acid components include aliphatic dicarboxylic acids (eg, saturated aliphatic dicarboxylic acids having about 2 to 14 carbon atoms such as adipic acid, azelaic acid, sebacic acid, etc.), alicyclic rings Group dicarboxylic acids (for example, tetrahydrophthalic acid, tetrahydroisophthalic acid, tetrahydroterephthalic acid, etc.) may be included.

Typical aromatic polyester resins include, for example, polyalkylene arylate resins [poly C _2-4 alkylene terephthalates such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT); poly C corresponding to the polyalkylene terephthalate. Examples thereof include _2-4 alkylene naphthalate (for example, polyethylene naphthalate) and the like, and poly 1,4-cyclohexyldimethylene terephthalate (PCT).

  These polyester resins can be used alone or in combination of two or more.

Preferred polyester resins include polyalkylene arylate resins, particularly polyester resins containing at least C _2-4 alkylene arylate units (for example, C _2-4 alkylene terephthalate units such as ethylene terephthalate and butylene terephthalate, particularly butylene terephthalate units). Is included. Specifically, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), a copolyester containing an ethylene terephthalate unit, a copolyester containing a butylene terephthalate unit, or a combination thereof is preferable.

The polyalkylene arylate resin may be a copolyester containing an alkylene arylate unit as a main component (for example, 50% by weight or more). Examples of the copolymer component include ethylene glycol, propylene glycol, butanediol, and hexanediol. Examples thereof include C _2-6 alkylene glycols such as poly C _2-4 alkylene glycol, asymmetric aromatic dicarboxylic acids such as phthalic acid and isophthalic acid or anhydrides thereof, and aliphatic dicarboxylic acids such as adipic acid. Further, a branched chain structure may be introduced into the linear polyester using a small amount of polyol and / or polycarboxylic acid.

  The holding member plastic may be made of a resin having compatibility (or miscibility) with the lens plastic in order to improve laser weldability. The resin having such compatibility may be the same resin (or the same kind of resin) as the lens plastic. It should be noted that compatibility between the plastic for the holding member and the plastic for the lens is usually not required in joining the lens and the holding member using heat caulking or an adhesive.

  The proportion of the resin having compatibility is, for example, 10% by weight or more (for example, 20 to 100% by weight), preferably 30% by weight or more (for example, about 40 to 99% by weight) of the entire plastic for holding member, and more preferably May be 50% by weight or more (for example, about 60 to 98% by weight).

  The number average molecular weight of the holding member plastic may be, for example, about 3,000 to 500,000, preferably 5,000 to 300,000, and more preferably about 10,000 to 200,000.

  Hereinafter, a combination of a typical lens plastic (1) and a holding member plastic (2) (particularly, a resin having compatibility with the lens plastic) will be exemplified.

(I) Combination in which plastic (1) is a cyclic olefin resin and plastic (2) is a resin containing 10% by weight or more of cyclic olefin resin (ii) Plastic (1) is a methacrylate ester resin And the plastic (2) is at least one selected from a methacrylic ester resin, a styrene resin (in particular, a styrene resin having vinyl cyanide as a polymerization component such as an ABS resin) and a polycarbonate resin. (Iii) The plastic (1) is a polycarbonate resin, and the plastic (2) is a methacrylate ester resin or a styrene resin (in particular, vinyl cyanide such as an ABS resin). Styrene resin having a polymerization component), polyalkylene arylate resin (particularly small Kutomo C _2-4 polyester resin containing an alkylene arylate unit), and at least one combination of a resin containing 10 wt% or more selected from polycarbonate resin.

  Among the above combinations, the combination (i) in which the lens plastic and the holding member plastic are made of a cyclic olefin resin is particularly preferable.

  The plastic constituting the holding member may be made of waste plastic (recycling plastic, reusable plastic, recycled product). Such waste plastic is not particularly limited, and examples thereof include waste plastic generated (or generated) by molding a plastic lens. Examples of waste plastics (or recovered products) produced (by-product) by molding include, for example, defective molding products, sprue obtained by injection molding (including injection compression molding, etc.) of the plastic lens (plastic in sprue, sprue Residual plastic) and runners (plastic of the runner, plastic remaining on the runner).

  Waste plastics (especially sprues, runners, etc.) generated or by-produced in the molding (or molding process) of such plastic lenses are the same as the lens plastics as described above and are compatible with the lens plastics. have. Therefore, the use of such waste plastic is extremely useful because it can improve the laser weldability and can effectively use the plastic generated by lens molding.

  When the holding member plastic is made of waste plastic (particularly, waste plastic produced by molding a lens), the proportion of the waste plastic is 10% by weight or more of the entire holding member plastic (for example, about 20 to 100% by weight). For example, 30% by weight or more (for example, about 35 to 100% by weight), preferably 40% by weight or more (for example, about 45 to 99% by weight), more preferably 50% by weight or more (for example, 60 to 98% by weight).

  The holding member contains various additives such as stabilizers (thermal stabilizers, ultraviolet absorbers, antioxidants, etc.), plasticizers, lubricants, fillers, colorants, flame retardants, antistatic agents and the like. You may go out. The holding member may contain these additives alone or in combination of two or more. In particular, the holding member may contain a filler (usually an inorganic filler) from the viewpoint of holding the lens.

  Examples of the filler include a fibrous filler, a plate-like filler, and a granular filler.

  Examples of the fibrous filler include inorganic fibers [glass fiber, carbon fiber, silica fiber, silica / alumina fiber, zirconia fiber, alumina fiber, silicon carbide fiber, metal fiber (stainless fiber, aluminum oxide fiber, etc.), ceramic fiber, and the like. , Titanic acid whiskers, boron whiskers, zinc oxide whiskers, asbestos, etc.], organic fibers (such as aramid fibers, polyacrylonitrile fibers) and the like. Examples of the plate filler include glass flakes, glass beads, talc, mica, graphite, and metal foil. Examples of the particulate filler include carbon black, silicon carbide, silica, quartz powder, hydrotalcite, glasses (glass beads, glass powder, milled glass fiber), carbonates (calcium carbonate, magnesium carbonate, etc.), silica Acid salts (calcium silicate, aluminum silicate, kaolin, clay, diatomaceous earth, wollastonite, etc.), metal oxides (iron oxide, titanium oxide, zinc oxide, alumina, etc.), sulfates (calcium sulfate, barium sulfate) Etc.).

  Of these fillers, inorganic fillers (for example, fibrous inorganic fillers such as glass fibers, and plate-like inorganic fillers such as talc and mica) are preferable from the viewpoint of mechanical properties, and glass fibers are particularly preferable. .

  The average fiber length of the fibrous filler may be, for example, 10 mm or less (for example, 0.1 to 10 mm), preferably 0.1 to 8 mm, and more preferably about 0.2 to 4 mm. The average fiber diameter of the fibrous filler may be, for example, about 0.1 to 50 μm, preferably about 0.5 to 30 μm, and more preferably about 1 to 20 μm. Moreover, the average particle diameter (or average diameter) of the non-fibrous filler (powder or plate-like filler) can be selected from a range of about 30 μm or less, for example, 10 μm or less (0.1 to 10 μm), preferably It may be about 5 μm or less (for example, 0.3 to 5 μm), more preferably about 0.5 to 5 μm (particularly 1 to 5 μm).

  These fillers may be surface-treated with a treating agent such as a sizing agent or a silane compound (such as a silane coupling agent) as necessary. These fillers can be used alone or in combination of two or more.

  The ratio of the filler (particularly inorganic filler) is, for example, 5 to 150 parts by weight, preferably 10 to 100 parts by weight, more preferably 100 parts by weight of the plastic (plastic for the holding member) constituting the holding member. It may be about 15 to 80 parts by weight, particularly about 20 to 70 parts by weight (for example, 20 to 60 parts by weight).

  Moreover, the holding member may contain a laser absorber as described later, and may contain a colorant (a colorant not belonging to the category of the laser absorber). As the colorant, a chromatic or achromatic colorant that can transmit laser light (or a colorant that is non-absorbable with respect to laser light) can be used. Examples of such a colorant include white dyes and pigments (for example, inorganic pigments such as titanium white, calcium carbonate, zinc oxide, zinc sulfide, and lithopone), yellow pigments (for example, cadmium yellow (cadomi yellow), chrome yellow ( Inorganic pigments such as chrome yellow), zinc chromate, ocher (ocher), organic pigments such as Hansa yellow, benzidine yellow, and pigment yellow], orange pigments, red pigments [for example, red mouth pigments, amber, cadmium red (fire red), Inorganic pigments such as red lead (lead tetroxide, Komyotan), organic pigments such as permanent red, lake red, watch chan red, brilliant carmine 6B], blue pigments [eg bitumen, ultramarine blue, cobalt blue (tenal) Inorganic pigments such as blue), organic pigments such as phthalocyanine blue], green pigments [for example, chromium Inorganic pigments such as over emissions, and the like organic pigments], such as phthalocyanine green. Further, as a black colorant, a black dye / pigment that is non-absorbable with respect to laser light, for example, “eBINDLTW-817OC”, “eBINDLTW-8012”, “eBINDLTW-8620C” from Orient Chemical Industry Co., Ltd., Black dyes and pigments available as “eBINDLTW-8630C”, “eBINDLTW-8400C”, “eBINDLTW-8950C”, “eBINDLTW-8200”, “eBINDLTW-8300”, “eBINDLTW-8250C”, etc. can be used.

  As the colorant, the dyes and pigments exemplified above may be used alone, or a plurality of colorants may be used in combination to adjust to a desired color tone. For example, the holding member can be colored black using three primary colors.

  The ratio of the colorant (colorant that does not substantially absorb the laser beam) is not particularly limited, but can be appropriately selected according to the plastic for the holding member, the type of the coloring agent, the oscillation wavelength of the laser beam, and the like. 0 to 10 parts by weight (for example, 0.0001 to 10 parts by weight), preferably 0.001 to 7 parts by weight, and more preferably about 0.01 to 5 parts by weight with respect to 100 parts by weight of the plastic. Also good.

  The total light transmittance (or visible light transmittance) of the plastic holding member (or plastic (2)) is, for example, 30% or less (for example, 0 to 25%), preferably 20% or less (for example, 0 to 15%). Degree), more preferably 10% or less (for example, about 0 to 5%).

  The holding member can be molded by a conventional molding method such as a compression molding method, a transfer molding method, an extrusion molding method, or an injection molding method.

  In the lens unit, an interface portion (contact portion, laser welded portion) between the plastic lens and the holding member can absorb at least laser light. For example, at the interface portion (or contact portion) between the plastic lens (especially the outer peripheral edge thereof) and the holding member, as long as at least one member has laser absorbability and laser welding is possible, both members May have laser absorptivity at the contact portion. As a specific method for making the interface portion at least absorbable with laser, a method in which the holding member contains a laser absorbent capable of absorbing laser, a laser is provided at least on the contact portion of the outer peripheral edge of the plastic lens with the holding member. Examples thereof include a method of forming a film containing an absorbent (laser absorbing film), a method of combining these, and the like. In a typical method, the holding member is often made of a laser absorbent so that laser absorption is possible at the interface portion.

  As the laser absorber (or laser light absorber), for example, an inorganic or organic dye / pigment having absorption in the wavelength region of the laser beam can be used depending on the wavelength of the laser beam. Acetylene black, lamp black, thermal black, furnace black, channel black, ketjen black, etc.), black pigments such as titanium black and black iron oxide (black pigments having laser absorption) are often used. These laser light absorbers can be used alone or in combination of two or more. The average particle size of the black pigment can be selected from a wide range of, for example, about 10 nm to 3 μm (preferably 10 nm to 1 μm). In particular, the average particle size of carbon black may be, for example, about 10 to 100 nm, preferably about 15 to 90 nm.

  When the holding member contains a laser light absorbent, the ratio of the laser light absorbent is 0.1 to 10 parts by weight, preferably 0.3 to 5 parts by weight, based on 100 parts by weight of the plastic for the holding member. Preferably, it may be about 0.4 to 4 parts by weight (for example, 0.5 to 3 parts by weight). The holding member may contain the laser light absorber as a colorant (laser-absorbing colorant), and further, as described above, a colorant (non-laser-absorbing agent such as an inorganic or organic dye / pigment). (Colorant) may be contained.

  The laser-absorbing film can be formed by, for example, a method of applying (or coating) an application agent containing a laser absorber to the outer peripheral edge portion of the lens (specifically, at least the contact portion with the holding member). The thickness (dry thickness) of the laser-absorbing coating may be, for example, about 0.1 to 20 μm, preferably about 0.3 to 10 μm, and more preferably about 0.5 to 5 μm.

  In many cases, at least one of the plastic lens and the holding member (usually at least the plastic lens) can transmit laser light. Specifically, (i) a laser-transmitting plastic lens having a laser-absorbing coating formed on the outer peripheral edge portion in contact with the holding member, and a laser-absorbing holding member or a laser-transmitting holding member are assembled. Or (ii) a laser transmissive plastic lens and a laser-absorbing holding member capable of absorbing laser may be combined, and the plastic lens and the holding member may be laser-welded by laser light irradiation. The laser-transmitting holding member is usually capable of transmitting laser light and does not substantially transmit visible light (for example, a total light transmittance of 10% or less) although it depends on the type of plastic lens and its application. Often). Such a laser transmissive holding member may be prepared, for example, by adding a non-laser absorbing colorant to the holding member plastic.

[Lens unit]
In the lens unit, the holding form of the plastic lens is not particularly limited, and various forms can be adopted. That is, the holding member may hold the plastic lens by contacting at least the outer peripheral edge, or may be held in contact with a part or all of the outer peripheral edge. Further, the contact between the outer peripheral edge of the plastic lens and the holding member may be any of point contact, line contact, or surface contact as long as laser welding is possible. Usually, from the viewpoint of holding stability and workability, the outer peripheral edge of the plastic lens and the holding member are often in surface contact at least at the welded portion. In this case, various modes that can be laser-welded, for example, a mounting convex portion that allows the outer peripheral edge of the plastic lens to come into surface contact are formed on the opening end surface of the holding member, and the outer peripheral edge of the plastic lens is formed by the mounting convex portion. A mode in which a plastic lens is held (or sandwiched) in a holding member that has a concave portion (a U-shaped concave portion) that can contact or fit the outer peripheral edge portion. Alternatively, laser welding may be performed by contacting (surface contact) the outer peripheral edge portion and the holding member.

  In the holding member, the width of the portion (contact portion, interface portion) in contact with the outer peripheral edge portion of the holding member (the width of the placing portion on which the outer peripheral edge portion is placed in FIGS. 1A and 2A, that is, FIG. 1A). G1 and corresponding to k2 in FIG. 2A), for example, 0.2 to 10 mm, preferably 0.3 to 5 mm (for example, 0.3 to 4 mm), and more preferably 0.4 to 3.5 mm (for example, 0 .5 to 3 mm), particularly about 0.6 to 2 mm (for example, 0.7 to 1.5 mm). In the present invention, even a contact portion having such a narrow width can be joined by laser welding (particularly spot welding) while minimizing the thermal effect acting on the lens.

  If necessary, a member that can hold the plastic lens may be used to hold or fix the plastic lens more firmly. For example, a notch step (or mounting step) having a depth larger than the thickness of the outer peripheral edge of the plastic lens is formed in the inner peripheral area of the upper end surface of the cylindrical holding member, and this notch step (or In order to hold or fix the outer peripheral edge of the plastic lens placed on the mounting step), a holding member (ring-shaped holding member) suitable for the notch step (or mounting step) is used as the plastic lens. You may mount | wear with the inner peripheral area of the opening upper end surface of a cylindrical holding member from the outer peripheral part.

  The holding member only needs to hold at least one lens, and may hold a plurality of lenses. Further, the holding (or contact) form of the holding member may be placed on the upper end surface of the opening of the holding member as in the example of FIGS. 1A and 2A, and the outer peripheral edge (or lens) is held by the holding member. Alternatively, when holding a plurality of lenses, these may be combined. For example, in the case of holding by holding, the holding member may be able to hold the outer peripheral edge portion of the lens by holding and contacting the non-hollow portion (or the inner wall surface of the holding member). In such a case, the holding member (or the inner wall surface of the holding member) and the lens can be joined by laser welding in a sandwiched state.

  In the lens unit of the present invention, the interface portion between the plastic lens and the holding member is joined by laser light irradiation. The outer peripheral edge portion of the plastic lens and the holding member are bonded to each other on the entire circumference of the outer peripheral area of the plastic lens (or the outer peripheral edge portion) by a method such as scanning the interface portion with laser. However, in order to suppress the influence (optical distortion, etc.) on the optical characteristics of the plastic lens as much as possible, the circumferential direction of the interface part [or the circumferential direction of the interface part or the plastic lens (or its outer peripheral edge part) And the circumferential direction of the holding member] are often joined at spots (or points) at a plurality of locations (for example, 2 to 10 locations, preferably 3 to 5 locations). If the number of spots is too small, welding (bonding) may be insufficient, and if the number of spots is too large, the lens may be affected by heat from the laser.

  The spot width (or diameter or laser spot diameter during laser welding, corresponding to s1 in FIG. 1A and s2 in FIG. 2A) is 2 mm or less (for example, 0.05 to For example, 0.1 to 0.8 mm, preferably 0.15 to 0.7 mm, more preferably 0.2 to 0.5 mm, and particularly 0.25 to 0.45 mm. It may be a degree. By reducing the width of the spot, the amount of generated heat can be reduced, and the thermal influence on the plastic lens can be efficiently suppressed. In many cases, the width of the spot is usually the same as or smaller than the width of the outer peripheral edge (or the placement portion). The ratio of the spot width to the outer peripheral edge width may be about 0.01 to 0.8, preferably about 0.05 to 0.7, and more preferably about 0.1 to 0.5.

  Further, the spot position (the portion welded by the laser, the laser welded portion, the joint portion) has a substantial lens function (the lens body portion) of the lens in order to suppress the thermal influence on the lens. ) As far as possible. Therefore, the distance (corresponding to m1 in FIG. 1A and m2 in FIG. 2A) between the spot and the lens main body (or the boundary between the outer peripheral edge and the lens main body) is, for example, 0 in a small camera lens unit. .3 mm or more (for example, 0.35 to 10 mm), preferably 0.4 mm or more (for example, 0.45 to 5 mm), more preferably 0.5 mm or more (for example, about 0.55 to 3 mm). Good.

[Lens Unit Manufacturing Method]
In the lens unit of the present invention, the outer peripheral edge portion of the imaging plastic lens and the plastic holding member are brought into contact with each other, and the contact portion (or the contact portion or the interface portion) is irradiated with laser light (and further the contact portion is heated). ), And can be obtained by bonding the plastic lens and the holding member.

  The laser light source used for welding can be selected according to the type of lens, the holding member, and the absorption wavelength of the laser absorbent, and usually YAG laser, semiconductor laser, glass laser, ruby laser, He-Ne laser, nitrogen Known lasers such as lasers, chelate lasers, and dye lasers can be used. Usually, the oscillation wavelength of a laser used for bonding an imaging lens may be 193 to 1600 nm, preferably 600 to 1500 nm, and more preferably about 800 to 1200 nm.

  The bonding (laser welding) may be performed by scanning the laser at the contact portion (or interface portion) between the outer peripheral edge portion and the holding member as described above. In many cases, spot welding is performed by irradiating a plurality of spots in a direction with a laser.

  The output of the laser beam to be irradiated may be, for example, about 1 to 30 W, preferably about 1 to 10 W, and more preferably about 1 to 5 W.

  In spot welding, the irradiation time of laser light may be, for example, 0.05 to 1.0 seconds, preferably 0.05 to 0.5 seconds, and more preferably 0.1 to 0.3 seconds. Good.

  The laser beam irradiation direction with respect to the contact portion is not particularly limited as long as laser welding is possible, but a direction that does not deteriorate the optical characteristics of the plastic lens, for example, a portion having a lens function of a plastic lens (the lens body portion or the like) ) Is preferably in a direction that does not transmit laser light. Specifically, for example, when (i) a laser-transmitting plastic lens and a laser-absorbing holding member are bonded, a laser is applied to the outer peripheral edge of the plastic lens (the outer peripheral edge substantially having no lens function). (Ii) When joining a laser transmissive plastic lens having a laser transmissive film and a laser transmissive holding member, the outer peripheral edge of the plastic lens ( The laser beam is transmitted to the outer peripheral edge that does not substantially have a lens function), or laser light is irradiated from the side surface (outer surface) of the holding member, and laser welding is performed at the contact portion (laser transmissive film portion). Also good.

  The lens unit only needs to include at least the plastic lens and the holding member, and may be a housing (or casing). Such a housing lens unit may be housed by a member (so-called lens barrel or the like) capable of housing (or casing) the lens unit via a holding member, and the holding member itself may be a housing (so-called lens barrel or the like). ) May be formed.

  In the present invention, the lens and the holding member are firmly suppressed while suppressing or preventing the thermal influence acting on the lens as much as possible, and suppressing or preventing the deformation of the lens and the holding member, the accompanying optical axis shift, and the optical distortion at a high level. Can be joined. Therefore, the lens unit of the present invention is a variety of devices including an imaging lens (or imaging system lens) unit, such as a camera, a computer, a word processor, a printer, a copier, a fax machine, a telephone, a mobile device (a mobile phone, a mobile phone). It can be used for information terminals (PDAs), automobile equipment, building equipment, astronomical equipment, and the like. In particular, in the present invention, even with a small imaging lens (and a highly accurate lens), the lens and the holding member can be joined without adversely affecting, for example, a small camera [for example, a mobile phone camera ( It is useful as an imaging lens unit such as a so-called camera for a mobile phone with a camera) and a vehicle-mounted camera module. The width (or diameter) of such a small camera lens may be about 10 mm or less.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

[Examples 1 to 11]
(Plastic lens creation)
Using the lens plastic shown in Table 1, the plastic lens shown in FIG. 1A was molded by an injection molding machine at the cylinder temperature shown in Table 1. In FIG. 1A, the lens body was molded with a thickness d1 of 2 mm, a width e1 of 3 mm, an outer peripheral edge thickness f1 of 1 mm, and a width g1 of 1 mm.

(Creating a holding member)
95.5 parts by weight of the plastic for holding member shown in Table 1 and 0.5 part by weight of carbon black were mixed using a twin screw extruder (manufactured by Nippon Steel Works, Ltd., “TEX30”), and the cylinder Extrusion was performed at a temperature of 250 ° C. to obtain pellets. In addition, when adding glass fiber, the glass fiber was mixed by the side feed and the pellet was obtained.

  And the holding member shown to the said FIG. 1A was shape | molded with the cylinder temperature shown in Table 1 with the injection molding machine using the obtained pellet. In FIG. 1A, the holding member was formed with a thickness g1 of 1 mm.

(Create lens unit)
The plastic lens obtained by the above method and the holding member are brought into contact in the same manner as in FIG. 1A, and the laser beam is transmitted from the outer peripheral edge using a laser welding apparatus (“FD-200” manufactured by Fine Device). The three spots located at substantially equal intervals in the circumferential direction of the interface portion (contact portion) between the lens and the holding member were irradiated with laser light to be joined (laser welding). In the laser light irradiation, the spot diameter s1 was 0.35 mm, the distance m1 between the spot and the lens body was 0.6 mm, the laser output was 3 W, and the laser irradiation time was 0.2 seconds.

[Examples 12 to 22]
(Plastic lens creation)
Using the lens material shown in Table 2, the plastic lens shown in FIG. 2A was molded by an injection molding machine at the cylinder temperature shown in Table 2. In FIG. 2A, the lens body was molded with a thickness d2 of 2 mm, a width e2 of 3 mm, an outer peripheral edge thickness f2 of 1 mm, and a width g2 of 1.5 mm.

(Creating a holding member)
95.5 parts by weight of the holding member material shown in Table 2 and 0.5 parts by weight of carbon black were mixed using a twin screw extruder (manufactured by Nippon Steel Works, Ltd., “TEX30”), and the cylinder Extrusion was performed at a temperature of 250 ° C. to obtain pellets. In addition, when adding glass fiber, the glass fiber was mixed by the side feed and the pellet was obtained.

  And the holding member shown to the said FIG. 2A was shape | molded with the cylinder temperature shown in Table 2 with the injection molding machine using the obtained pellet. 2A, the thickness h2 of the holding member was 1.5 mm, the width k2 of the mounting portion was 1 mm, and the height f2 of the notch step portion was 1 mm.

(Create lens unit)
The plastic lens obtained by the above method and the holding member are brought into contact in the same manner as in FIG. 2A, and the laser beam is transmitted from the outer peripheral edge using a laser welding apparatus (“FD-200” manufactured by Fine Device). The three spots located at substantially equal intervals in the circumferential direction of the interface portion (contact portion) between the lens and the holding member were irradiated with laser light to be joined (laser welding). In laser light irradiation, the spot diameter s2 is 0.35 mm, the distance m2 between the spot and the lens body is 1.1 mm (0.5 mm + 0.6 mm), the laser output is 3 W, and the laser irradiation time is 0.2 seconds. did.

  The laser weldability of the lens units obtained in Examples 1 to 22 was evaluated according to the following criteria.

○: Two molded bodies were joined. ×: Two molded bodies were not joined.

  The results are shown in Tables 1 and 2.

  The resins and glass fibers used in the examples are as follows. In Tables 1 and 2, the following abbreviations are used.

PC: Polycarbonate resin (Mitsubishi Engineer Plastic Co., Ltd., trade name "Iupilon H4000")
COC-1: Cyclic Olefin Resin (Mitsui Chemicals, Inc., trade name “Apel 5014DP”)
COC-2: Cyclic olefin resin (manufactured by Nippon Zeon Co., Ltd., trade name “ZEONEX E48R”)
PMMA: Polymethyl methacrylate (Mitsubishi Rayon Co., Ltd., trade name “VH”)
ABS-GF: ABS resin (manufactured by Daicel Polymer Co., Ltd., “Cebian-V VGR20 (GF 20% filled ABS) black colored product”)
PBT-GF: Polybutylene terephthalate resin (manufactured by Wintech Polymer Co., Ltd., trade name "Duranex 3200 black colored product")
GF-1: Glass fiber for olefin (manufactured by Nippon Electric Glass Co., Ltd., trade name “ECS-03-T-480” 13 μ diameter, 3 mm chopped)
GF-2: Glass fiber for polyester (manufactured by Nippon Electric Glass Co., Ltd., trade name “ECS-03-T-120” 13 μ diameter, 4 mm chopped)
PC / GF-1: Mixture containing 80 parts by weight of “PC” and 20 parts by weight of “GF-2” PC / COC / GF-1: 60 parts by weight of “PC”, 20 parts by weight of “COC-2” and “GF” -2 "Mixture containing 20 parts by weight PC / COC / GF-2: Mixture containing 10 parts by weight of" PC ", 70 parts by weight of" COC-1 "and 20 parts by weight of" GF-1 "COC / GF-1: Mixture containing 80 parts by weight of “COC-1” and 20 parts by weight of “GF-1” PC / PMMA: Mixture containing 40 parts by weight of “PC” and 60 parts by weight of “PMMA”.

FIG. 1A is a schematic cross-sectional view showing an example of a lens unit of the present invention. FIG. 1B is a plan view of the lens unit shown in FIG. 1A. FIG. 2A is a schematic cross-sectional view showing another example of the lens unit of the present invention. FIG. 2B is a plan view of the lens unit shown in FIG. 2A.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,20 ... Lens unit 1,11 ... Plastic lens for imaging 1a, 11a ... Lens body part 1b, 11b ... Outer peripheral edge part 2,12 ... Holding member 12a ... Placement surface

Claims (14)

  The lens unit includes an imaging plastic lens and a plastic holding member for holding the outer peripheral edge of the plastic lens, and can absorb at least laser light at an interface portion between the plastic lens and the holding member. A lens unit in which the plastic lens and the holding member are joined by laser light irradiation.   The unit according to claim 1, wherein the plastic lens is composed of a cyclic olefin resin, a methacrylic ester resin, or a polycarbonate resin.   The unit according to claim 1, wherein the holding member is composed of at least one selected from a cyclic olefin resin, a methacrylic ester resin, a styrene resin, a polyester resin, and a polycarbonate resin.   The unit according to claim 1, wherein the plastic constituting the holding member contains 10% by weight or more of a resin having compatibility with the plastic constituting the plastic lens, based on the whole plastic for the holding member. The unit according to claim 1, wherein the plastic (1) constituting the plastic lens and the plastic (2) constituting the holding member are any combination of the following (i) to (iii).
(I) A combination in which plastic (1) is a cyclic olefin resin and plastic (2) is a resin containing 10% by weight or more of a cyclic olefin resin (ii) Plastic (1) is a methacrylate ester resin And the plastic (2) is a resin comprising at least one selected from a methacrylic ester resin, a styrene resin and a polycarbonate resin containing vinyl cyanide as a polymerization component (iii) plastic (1) is a polycarbonate resin, and the plastic (2) is at least selected from a methacrylic acid ester resin, a styrene resin having vinyl cyanide as a polymerization component, a polyalkylene arylate resin, and a polycarbonate resin. Combination that is a resin containing 10% by weight or more of one kind   The unit according to claim 1, wherein the plastic constituting the holding member is made of waste plastic.   The unit according to claim 1, wherein the plastic constituting the holding member is made of waste plastic produced by molding a plastic lens.   The unit according to claim 1, wherein the holding member includes an inorganic filler at a ratio of 5 to 150 parts by weight with respect to 100 parts by weight of the plastic constituting the holding member.   The unit according to claim 1, wherein the outer peripheral edge of the plastic lens and the holding member are joined at a plurality of spots in the circumferential direction.   The unit according to claim 9, wherein the spot has a width of 0.1 to 0.8 mm.   The plastic lens is a plastic lens having a lens main body that can be imaged and a lens outer peripheral edge located around the lens main body, the width of the lens outer peripheral edge being 0.2 to 5 mm, and a spot The unit according to claim 9, wherein a distance between the lens and the lens main body is 0.3 mm or more.   The ratio of the width of the lens outer peripheral edge to the width of the lens main body is 0.2 to 0.7, the width of the lens outer peripheral edge is 0.3 to 2 mm, and the distance between the spot and the lens main body is The unit according to claim 11, which is 0.5 mm or more.   2. The method of manufacturing a lens unit according to claim 1, wherein the outer peripheral edge of the imaging plastic lens and the plastic holding member are brought into contact with each other, and the contact portion is irradiated with laser light to join the plastic lens and the holding member.   A device comprising the lens unit according to claim 1.

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