JP5568375B2 - Mold and lens manufacturing apparatus, lens manufactured by the manufacturing apparatus, and imaging apparatus including the lens - Google Patents

Description

  The present invention relates to a mold and a manufacturing apparatus used for manufacturing a lens, a lens manufactured by the manufacturing apparatus, and an imaging apparatus including the lens.

  Imaging devices used for mobile phones and surveillance cameras generally form images on solid-state imaging devices such as CCD (Charge Coupled Device) image sensors and CMOS (Complementary Metal-Oxide Semiconductor) image sensors, and on the light-receiving surface of the solid-state imaging device. Lens unit. In recent years, lenses made of a resin that is inexpensive and has excellent moldability are used as lenses included in the lens unit.

  The above imaging device is generally modularized and mounted on a circuit board. In order to simplify the mounting process, reflow is adopted for mounting the imaging apparatus. Reflow is a method in which solder is placed in advance on a circuit board board where components are mounted, the parts are placed there and heated together with the circuit board, thereby melting the solder and soldering the parts to the circuit board. Say.

  In reflow, the imaging device is exposed to a temperature of 200 ° C. or higher for several seconds to several tens of seconds. Heat resistance is also required for the lenses of the lens unit constituting the imaging apparatus. Therefore, there is known a lens unit formed of an energy curable resin such as a thermosetting resin or a photocurable resin (for example, see Patent Document 1).

  In general, a resin lens is manufactured by compression molding resin with a molding die composed of an upper die and a lower die and a barrel die surrounding the upper die and the lower die. It is manufactured by placing resin, then lowering the upper mold, and compression molding while spreading the resin between the molding surface of the lower mold and the molding surface of the upper mold.

  By the way, the energy curable resin before curing generally has a low viscosity. If the viscosity of the resin is low, the resin accumulated at the center of the molding surface of the lower mold will naturally spread. The spread of the resin tends to be biased in a part of the radial direction. As a result, the resin is partially brought into contact with the inner peripheral surface of the body mold and pulled there, and is held in a biased state with respect to the center of the molding surface. If it does so, the transfer defect of the molding surface shape of an upper mold | type and a lower mold | type will arise, and the yield of a lens will fall.

  In Patent Document 2, an energy curable resin containing both a thermal polymerization initiator and a photopolymerization initiator is used, and the viscosity of the resin is increased to some extent by photopolymerization before molding, and compressed in that state. A technique is described in which it is molded and then thermally polymerized and cured. According to this, the spread of the resin can be prevented and the resin can be held at the center of the molding surface of the lower mold. However, this technique is limited to special resins containing both a thermal polymerization initiator and a photopolymerization initiator.

JP 2009-98614 A JP 2009-126011 A

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to improve yield when manufacturing a lens using a general energy curable resin.

(1) A mold used for manufacturing a lens made of an energy curable resin, comprising an upper mold and a lower mold, and a body mold surrounding the upper mold and the lower mold, the upper mold being It has a molding surface having a shape obtained by inverting the shape of one surface of the front and back surfaces of the lens, and the lower mold has a molding surface having a shape obtained by inverting the shape of the other surface of the front and back surfaces of the lens. The lower mold has a convex surface provided with protrusions over the entire periphery along the edge of the molding surface, and the volume of the portion surrounded by the molding surface and the convex line is the lens. The mold is smaller than the volume of the mold, and the protrusion has an edge at a connection portion between the projecting end surface and the inner peripheral surface, and suppresses the spread of the resin accumulated on the molding surface of the lower mold.
(2) A mold used for manufacturing a lens made of an energy curable resin, comprising an upper mold and a lower mold, and a body mold surrounding the upper mold and the lower mold, the upper mold being It has a molding surface having a shape obtained by inverting the shape of one surface of the front and back surfaces of the lens, and the lower mold has a molding surface having a shape obtained by inverting the shape of the other surface of the front and back surfaces of the lens. And a molding surface of the lower mold is provided at a central portion of the resin pile portion on which the resin is piled up, and the resin piled up on the resin pile portion around the resin pile portion. And a stopper that suppresses spreading, and the stopper is a water-repellent surface.

According to the present invention, the resin accumulated on the molding surface of the lower mold is suppressed from spreading by the ridges or the water repellent surface , and contact with the inner peripheral surface of the body mold is prevented. As a result, even when a general energy curable resin is used, the resin can be held at the center of the molding surface, preventing transfer defects of the molding surface shape of the upper mold and the lower mold to the resin. The yield of the manufactured lens can be improved.

The figure which shows an example of the imaging device for describing embodiment of this invention. The figure which shows an example of the manufacturing apparatus which manufactures the lens contained in the imaging device of FIG. The figure which shows the manufacturing method of the lens using the manufacturing apparatus of FIG. The figure which expands and shows the part enclosed by the circle IV in FIG. The figure which shows the other example of the manufacturing apparatus of FIG.

  FIG. 1 shows an example of an imaging apparatus.

  An imaging apparatus 1 shown in FIG. 1 includes a sensor 2 and a lens unit 3.

  The sensor 2 includes a substrate 10 made of a semiconductor such as silicon, and a solid-state image sensor 11 provided at a substantially central portion thereof. The solid-state imaging device 11 is a CCD image sensor or a CMOS image sensor, for example, and repeats a well-known film formation process, photolithography process, etching process, impurity addition process, and the like on the substrate 10 to receive a light receiving region on the substrate 10. , Electrodes, insulating films, wirings, and the like are formed.

  The lens unit 3 includes an optical system 4 including one or more lenses and a lens barrel 5 that holds the optical system 4. In the illustrated example, the optical system 4 is disposed between the first lens 20 disposed on the incident side, the second lens 21 disposed on the exit side, and the first lens 20 and the second lens 21. It comprises a diaphragm 22. Both the first lens 20 and the second lens 21 are made of a translucent resin. The diaphragm 22 is made of a light-shielding material and is formed of a metal plate such as stainless steel. Note that the configuration of the optical system 4 is not limited to the illustrated example. For example, the number of lenses may be one or three or more, and the diaphragm 22 may be on the incident surface of the first lens 20. You may arrange | position in an appropriate location.

  The first lens 20 includes a lens part 30 having optical surfaces on the front and back sides, and an edge part 31 that spreads around the lens part 30 in a bowl shape. Similarly, the second lens 21 includes a lens part 32 having optical surfaces on the front and back sides and an edge part 33 that spreads around the lens part 32 in a bowl shape. The first lens 20 and the second lens 21 are overlapped with the optical axes of the lens portions 30 and 32 being matched.

  On the opposing surfaces of the edge portion 31 of the first lens 20 and the edge portion 33 of the second lens 21 that are opposed to each other, fitting portions that are fitted to each other are provided. The fitting part 34 provided in the edge part 31 of the first lens 20 is an annular convex part centering on the optical axis of the lens part 30. The fitting portion 35 provided on the edge portion 33 of the second lens 21 is an annular convex portion centered on the optical axis of the lens portion 32, and is fitted into the fitting portion 34 of the first lens 20. To do. The inner peripheral surface of the fitting portion 34 of the first lens 20 and the outer peripheral surface of the fitting portion 35 of the second lens 21 are tapered surfaces that are aligned with each other. The first lens 20 and the second lens 21 are positioned relative to each other so that the optical axes of the lens portions 30 and 32 coincide with each other by fitting the fitting portions 34 and 35.

  The lens barrel 5 includes a tube portion 40, a lid portion 41 provided at one end portion in the axial direction of the tube portion 40, a pedestal portion 42 provided at the other end portion in the axial direction of the tube portion 40, It is comprised by the pressing member 43 arrange | positioned facing the cover part 41 within the cylinder part 40. As shown in FIG. The lens barrel 5 is made of a light-shielding material, for example, a resin such as a black liquid crystal polymer.

  The optical system 4 is disposed in the cylindrical portion 40 with its optical axis aligned with the central axis of the cylindrical portion 40, sandwiched between the lid portion 41 and the pressing member 43, and held by the lens barrel 5. An opening 44 is provided at the center of the lid 41 through which the optical axis of the optical system 4 passes, and light enters the optical system 4 through the opening 44.

  On the opposing surfaces of the edge portion 31 and the lid portion 41 of the first lens 20 of the opposing optical system 4, fitting portions that are fitted to each other are provided. The fitting portion 36 provided in the edge portion 31 of the first lens 20 is an annular convex portion centered on the optical axis of the optical system 4 (the optical axis of the lens portion 30). Further, the fitting portion 45 provided in the lid portion 41 is an annular convex portion centering on the central axis of the cylindrical portion 40 and is fitted into the fitting portion 36 of the first lens 20. The inner peripheral surface of the fitting portion 36 of the first lens 32 and the outer peripheral surface of the fitting portion 45 of the lid portion 41 are tapered surfaces that are aligned with each other. The optical system 4 is positioned so that its optical axis coincides with the central axis of the cylindrical portion 40 by fitting the fitting portion 36 of the first lens 20 with the fitting portion 45 of the lid portion 41.

  The positioning of the optical system 4 with respect to the lens barrel 5 is performed by fitting the fitting portion 36 of the first lens 20 to the fitting portion 45 of the lid portion 41 as described above. A gap is provided between the outer peripheral surfaces of the first lens 20 and the second lens 21 and the inner peripheral surface of the cylindrical portion 40. This gap absorbs the difference in thermal expansion between the optical system 4 and the lens barrel 5 in a reflow process described later, and relaxes the stress acting on the optical system 4.

  The lens unit 3 is integrated with the sensor 2 by joining the pedestal 42 of the lens barrel 5 to the substrate 10 of the sensor 2. The light incident on the optical system 4 through the opening 44 of the lens barrel 5 forms an image on the light receiving surface of the solid-state imaging device 11 of the sensor 2.

  The imaging device 1 configured as described above is mounted on a circuit board of an electronic device by reflow processing. That is, paste solder is printed in advance on the circuit board at a position where the imaging device 1 is mounted, and the imaging device 1 is placed there. Then, the circuit board including the image pickup apparatus 1 is subjected to heat treatment such as irradiation of infrared rays or hot air blowing, thereby melting the solder and mounting the image pickup apparatus 1 on the circuit board.

  Since the entire imaging device 1 is heated at the reflow temperature in the reflow process, the resin forming the first lens 20 and the second lens 21 has heat resistance enough to prevent thermal deformation even after the reflow process. As such a resin, an energy curable resin can be used. For example, a thermosetting resin that is cured by heat such as a silicone resin, an epoxy resin, or a phenol resin, or an ultraviolet ray such as an epoxy resin or an acrylic resin. It is possible to use a photo-curable resin that is cured by irradiation.

  Regarding the heat resistance of the resin forming the lenses 20 and 21, the glass transition temperature of the cured product is preferably 200 ° C or higher, more preferably 250 ° C or higher, and particularly preferably 300 ° C or higher. In order to impart such high heat resistance to the resin, it is necessary to constrain the mobility at the molecular level, and effective means include (1) means for increasing the crosslinking density per unit volume, (2 ) Means utilizing a resin having a rigid ring structure (for example, alicyclic structures such as cyclohexane, norbornane, tetracyclododecane, aromatic ring structures such as benzene and naphthalene, cardo structures such as 9,9′-biphenylfluorene, spirobiindane, etc. Resins having a spiro structure, specifically, for example, JP-A-9-137043, JP-A-10-67970, JP-A-2003-55316, JP-A-2007-334018, JP-A-2007-238883, etc. (3) means for uniformly dispersing a substance having a high Tg such as inorganic fine particles (for example, JP-A-5-20902) JP-described), and the like in the 10-298265 Patent Publication. A plurality of these means may be used in combination, and it is preferable to make adjustments within a range that does not impair other characteristics such as fluidity, shrinkage, and refractive index characteristics.

  Moreover, it is preferable that the resin forming the lenses 20 and 21 has an appropriate fluidity before curing from the viewpoint of moldability such as the shape transfer suitability of the mold. Specifically, it is liquid at room temperature and has a viscosity of about 1000 to 50000 mPa · s.

  The resin forming the lenses 20 and 21 is preferably a resin having a small volume shrinkage due to the curing reaction from the viewpoint of shape transfer accuracy. The curing shrinkage of the resin is preferably 10% or less, more preferably 5% or less, and particularly preferably 3% or less. Examples of the resin having a low cure shrinkage include (1) resins containing a high molecular weight curing agent (such as a prepolymer) (for example, JP-A Nos. 2001-19740, 2004-302293, and 2007-212147). The number average molecular weight of the high molecular weight curing agent is preferably in the range of 200 to 100,000, more preferably in the range of 500 to 50,000, and particularly preferably in the range of 1,000 to 20,000. The value calculated by the number average molecular weight of the curing agent / number of curing reactive groups is preferably in the range of 50 to 10,000, more preferably in the range of 100 to 5,000. Preferably, it is in the range of 200 to 3,000.), (2) Resins containing non-reactive substances (organic / inorganic fine particles, non-reactive resins, etc.) (Described in JP-A-6-298883, JP-A-2001-247793, JP-A-2006-225434, etc.), (3) Resins containing low-shrinkage crosslinking reactive groups (for example, ring-opening polymerizable groups (for example, epoxy groups ( For example, described in JP-A-2004-210932, etc.), oxetanyl group (for example, described in JP-A-8-134405), episulfide group (for example, described in JP-A-2002-105110), cyclic carbonate Groups (for example, described in JP-A-7-62065) and the like, ene / thiol curing groups (for example, described in JP-A 2003-20334, etc.), hydrosilylation curing groups (for example, JP-A-2005-15666). (4) Resin containing a rigid skeleton resin (fluorene, adamantane, isophorone, etc.) Described in JP-A-137043), and (5) a resin containing two types of monomers having different polymerizable groups to form an interpenetrating network structure (so-called IPN structure) (for example, JP-A-2006-131868) ), (6) Resins containing expansive substances (for example, described in JP-A-2004-2719, JP-A-2008-238417, etc.) and the like, and can be suitably used in the present invention. . In addition, it is preferable from the viewpoint of optimizing physical properties to use a plurality of curing shrinkage reducing means in combination (for example, a prepolymer containing a ring-opening polymerizable group and a resin containing fine particles).

  In addition, the resin forming the lenses 20 and 21 is desirably a mixture of two or more types of resins having different Abbe numbers. The resin on the high Abbe number side preferably has an Abbe number (νd) of 50 or more, more preferably 55 or more, and particularly preferably 60 or more. The refractive index (nd) is preferably 1.52 or more, more preferably 1.55 or more, and particularly preferably 1.57 or more. Such a resin is preferably an aliphatic resin, particularly a resin having an alicyclic structure (for example, a resin having a cyclic structure such as cyclohexane, norbornane, adamantane, tricyclodecane, tetracyclododecane, specifically, for example, JP-A-10-152551, JP-A-2002-212500, JP-A-2003-20334, JP-A-2004-210932, JP-2006-199790, JP-2007-2144, JP-2007-284650. And the resin described in JP-A-2008-105999. The resin on the low Abbe number side preferably has an Abbe number (νd) of 30 or less, more preferably 25 or less, and particularly preferably 20 or less. The refractive index (nd) is preferably 1.60 or more, more preferably 1.63 or more, and particularly preferably 1.65 or more. Such a resin is preferably a resin having an aromatic structure. For example, a resin having a structure such as 9,9′-diarylfluorene, naphthalene, benzothiazole, benzotriazole (specifically, for example, JP-A-60-38411). Publication No. 10-67977, No. 2002-47335, No. 2003-238848, No. 2004-83855, No. 2005-325331, No. 2007-238883, International Publication No. 2006/095610 pamphlet, Japanese Patent No. 2537540, and the like) are preferable.

  In addition, in the resin forming the lenses 20 and 21, it is preferable to disperse inorganic fine particles in the matrix in order to increase the refractive index or adjust the Abbe number. Examples of the inorganic fine particles include oxide fine particles, sulfide fine particles, selenide fine particles, and telluride fine particles. More specifically, for example, fine particles of zirconium oxide, titanium oxide, zinc oxide, tin oxide, niobium oxide, cerium oxide, aluminum oxide, lanthanum oxide, yttrium oxide, zinc sulfide, and the like can be given. In particular, it is preferable to disperse fine particles such as lanthanum oxide, aluminum oxide, and zirconium oxide for the high Abbe number resin, and titanium oxide, tin oxide, zirconium oxide, and the like for the low Abbe number resin. It is preferable to disperse the fine particles. The inorganic fine particles may be used alone or in combination of two or more. Moreover, the composite by several components may be sufficient. In addition, for various purposes such as reducing photocatalytic activity and water absorption, the inorganic fine particles are doped with different metals, the surface layer is coated with different metal oxides such as silica and alumina, silane coupling agents and titanate cups. The surface may be modified with a ring agent, an organic acid (carboxylic acid, sulfonic acid, phosphoric acid, phosphonic acid, etc.) or a dispersant having an organic acid group. The number average particle size of the inorganic fine particles is usually about 1 nm to 1000 nm, but if it is too small, the properties of the substance may change. If it is too large, the influence of Rayleigh scattering becomes remarkable, so 1 nm to 15 nm is preferable. 2 nm to 10 nm are more preferable, and 3 nm to 7 nm are particularly preferable. Further, it is desirable that the particle size distribution of the inorganic fine particles is narrow. There are various ways of defining such monodisperse particles. For example, a numerical value range as described in JP-A No. 2006-160992 applies to a preferable particle size distribution range. Here, the above-mentioned number average primary particle size can be measured by, for example, an X-ray diffraction (XRD) apparatus or a transmission electron microscope (TEM). The refractive index of the inorganic fine particles is preferably 1.90 to 3.00, more preferably 1.90 to 2.70, and more preferably 2.00 to 2.70 at 22 ° C. and a wavelength of 589 nm. It is particularly preferred that The content of the inorganic fine particles with respect to the resin is preferably 5% by mass or more, more preferably 10 to 70% by mass, and particularly preferably 30 to 60% by mass from the viewpoint of transparency and high refractive index.

  In order to uniformly disperse the fine particles in the resin, for example, a dispersant containing a functional group having reactivity with the resin monomer forming the matrix (for example, described in Examples of JP-A-2007-238884), hydrophobic segment And a block copolymer composed of a hydrophilic segment (for example, described in JP-A-2007-2111164), or a resin having a functional group capable of forming an arbitrary chemical bond with inorganic fine particles at the polymer terminal or side chain ( For example, it is desirable to disperse the fine particles by appropriately using JP-A-2007-238929, JP-A-2007-238930, and the like.

  In addition, the resins forming the lenses 20 and 21 are appropriately blended with known release agents such as silicone-based, fluorine-based, and long-chain alkyl group-containing compounds and additives such as antioxidants such as hindered phenols. May be.

  Moreover, a curing catalyst or an initiator can be blended in the resin forming the lenses 20 and 21 as necessary. Specific examples include compounds that accelerate the curing reaction (radical polymerization or ionic polymerization) by the action of heat or light described in JP-A-2005-92099 (paragraph numbers [0063] to [0070]). Can do. The amount of addition of these curing reaction accelerators varies depending on the type of catalyst and initiator, or the difference in the curing reactive site, and cannot be specified in general. On the other hand, about 0.1-15 mass% is preferable, and about 0.5-5 mass% is more preferable.

  The resin forming the lenses 20 and 21 can be manufactured by appropriately blending the above components. At this time, if other components can be dissolved in the liquid low molecular weight monomer (reactive diluent), etc., it is not necessary to add a separate solvent, but if this is not the case, use a solvent. A curable resin can be produced by dissolving each component. The solvent that can be used for the curable resin is not particularly limited and may be appropriately selected as long as the composition can be uniformly dissolved or dispersed without precipitation. Specifically, for example, ketones (Eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.), esters (eg, ethyl acetate, butyl acetate, etc.), ethers (eg, tetrahydrofuran, 1,4-dioxane, etc.) alcohols (eg, methanol, ethanol, isopropyl, etc.) Alcohol, butanol, ethylene glycol, etc.), aromatic hydrocarbons (eg, toluene, xylene, etc.), water and the like. When the curable resin contains a solvent, it is preferable to perform molding after drying the solvent.

  Hereinafter, the manufacturing of the lens will be described using the first lens 20 as an example.

  FIG. 2 shows an example of a lens manufacturing apparatus.

  The manufacturing apparatus 100 includes a mold 50, a resin supply unit 101, a drive unit 102, and an energy supply unit 103.

  The molding die 50 includes an upper die 51, a lower die 52, and a body die 53. The trunk mold 53 is formed in a cylindrical shape. The upper mold 51 includes a columnar main body 54 that is inserted into the body mold 53, and a flange 55 that is provided at the base end of the main body 54 and spreads around the main body 54. The flange portion 55 abuts on the axially upper end portion of the trunk mold 53 and defines the amount of insertion of the main body section 54 into the trunk mold 53. Similarly, the lower mold 52 includes a columnar main body 56 that is inserted into the body mold 53, and a flange 57 that is provided at the base end of the main body 56 and spreads in a bowl shape around the main body 56. It is configured. The flange portion 57 is in contact with the lower end portion in the axial direction of the trunk mold 53 and defines the amount of insertion of the main body section 56 into the trunk mold 53. Between the outer peripheral surface of the main body portion 54 of the upper mold 51 and the outer peripheral surface of the main body portion 56 of the lower mold 52 and the inner peripheral surface 64 of the trunk mold 53, the main body portions 54 and 56 are slightly inserted and removed. Each gap is provided.

  The front end surface of the main body portion 54 of the upper mold 51 is a molding surface 60 and has a shape obtained by reversing the surface shape of one of the front and back surfaces of the first lens 20, and a substantially central portion of the molding surface 60 of the upper mold 51. Is provided with an optical surface molding portion 61 having a shape obtained by inverting one optical surface of the lens portion 30 of the first lens 20. The front end surface of the main body portion 56 of the lower mold 52 is also a molding surface 62 and has a shape obtained by inverting the other surface shape of the front and back surfaces of the first lens 20. Is provided with an optical surface molding portion 63 having a shape obtained by inverting the other optical surface of the lens portion 30. The lens portion 30 of the first lens 20 shown in FIG. 1 has a convex spherical optical surface on the incident side and a concave spherical surface on the outgoing side. In the illustrated example, the optical surface of the upper mold 51 is used. The surface molding unit 61 is formed into a convex spherical shape obtained by inverting the optical surface on the emission side, and the optical surface molding unit 63 of the lower mold 52 is molded into a concave spherical shape obtained by inverting the optical surface on the incident side. .

  An annular ridge 66 is formed on the molding surface 62 of the lower mold 52 so as to surround the entire circumference of the optical surface molding portion 63. In the example shown in the drawing, the ridge 66 is formed on the molding surface 62. It is formed along the edge. The volume of the portion surrounded by the ridge 66 and the molding surface 62 is smaller than the volume of the lens 20. And the edge 66c is provided in the connection location of the surface 66a of the protrusion of the protruding item | line 66, and the internal peripheral surface 66b.

  With the main body part 54 of the upper mold 51 and the main body part 56 of the lower mold 52 inserted into the body mold 53, the molding surface 60 of the upper mold 51, the molding surface 62 of the lower mold 52, and the body mold 53, respectively. A cavity is formed surrounded by the inner peripheral surface 64, and the molding die 50 is molded by accommodating the above-described resin in the cavity.

  For example, a dispenser or the like is used as the resin supply unit 101, and the above-described resin for forming the first lens 20 is quantitatively supplied onto the optical surface molding unit 63 of the molding surface 62 of the lower mold 52.

  For example, a press machine or the like is used as the driving unit 102, and at least one of the upper mold 51 and the lower mold 52 is moved to expand and contract the interval between the molding surface 60 of the upper mold 51 and the molding surface 62 of the lower mold 52. In the illustrated example, the lower mold 52 is placed and fixed on the table of the press machine, and the upper mold 51 is attached to the piston of the press machine and moved up and down relative to the lower mold 52.

  The energy supply means 103 supplies curing energy to the resin supplied to the mold 50. The energy supply means 103 is appropriately selected depending on the resin. For a thermosetting resin, for example, a heat source such as a heater that contacts the mold 50 and heats the mold, or high-frequency induction heating is applied to the mold 50. A coil or the like for heating the mold in a non-contact manner is used, and a light source such as an ultraviolet lamp is used for the photocurable resin.

  In FIG. 3, an example of the manufacturing method of the 1st lens 20 using the manufacturing apparatus 100 is shown.

(Supply process)
First, the body 53 is covered with the body 53 of the lower mold 52, and the molding surface 62 of the lower mold 52 is surrounded by the body 53. Then, the resin M is supplied quantitatively on the optical surface molding portion 63 of the molding surface 62 of the lower mold 52 by the resin supply means 101. The body 53 may be covered with the main body 56 of the lower mold 52 after the resin M is supplied onto the optical surface molding section 63 of the lower mold 52. (FIG. 3A)

(Molding process)
Next, the upper die 51 is lowered by the driving means 102, and the main body portion 54 of the upper die 51 is inserted into the barrel die 53 until the flange portion 55 contacts the end portion of the barrel die 53. As the main body 54 is inserted, the distance between the molding surface 60 of the upper mold 51 and the molding surface 62 of the lower mold 52 is narrowed, and the resin M is sandwiched between the molding surfaces 60 and 62. Accordingly, the resin M is deformed along the molding surfaces 60 and 62 while being spread between the molding surfaces 60 and 62. The lens portion 30 of the first lens 20 is molded by the optical surface molding portions 61 and 63 provided on both molding surfaces 60 and 62, respectively, and the optical surface molding portions 61 and 63 of the both molding surfaces 60 and 62 are formed. The edge portion 31 of the first lens 20 is molded at the portion other than the portion. (FIG. 3B)

(Curing process)
Next, the energy supply means 103 supplies curing energy E to the molded resin M, and the resin M is cured. When the resin M is a thermosetting resin, the mold 50 is heated and heat is supplied to the resin M through the mold 50. When the resin M is a photocurable resin, at least one of the upper mold 51, the lower mold 52, and the body mold 53 constituting the mold 50 is formed of a translucent material such as glass. The mold 50 is irradiated with light, transmitted through the mold 50, and supplied to the resin M. (FIG. 3C)

(Release process)
Next, the upper mold 51 is raised by the driving means 102, the main body 54 of the upper mold 51 is removed from the barrel mold 53, and the first lens 20 made of the cured resin M is taken out from the molding mold 50. The first lens 20 can be taken out automatically using, for example, a robot arm. (FIG. 3D)

  FIG. 4 shows the resin supply process in the manufacturing method described above in detail.

  The resin M supplied by the resin supply means 101 is accumulated on the optical surface molding part 63 of the molding surface 62 of the lower mold 52, but naturally spreads around the optical surface molding part 63, and around the optical surface molding part 63. The ridge 66 surrounding the

  As described above, the volume of the portion surrounded by the molding surface 62 and the ridge 66 is smaller than the volume of the lens 20, that is, smaller than the volume of the resin M supplied by the resin supply means 101. Therefore, the resin M overflows from the portion surrounded by the molding surface 62 and the ridge 66, but due to the surface tension, the resin M exhibits a bulging shape raised above the ridge 66, and further beyond the ridge 66 to the outer diameter side. It is suppressed from spreading.

  In particular, the ridge 66 has an edge 66c at a connection portion between the protruding end surface 66a and the inner peripheral surface 66b, and the wetting and spreading of the resin M from the inner peripheral surface 66b to the protruding end surface 66a is suppressed at the edge 66c. The Thereby, it can suppress more reliably that resin M spreads beyond the protruding item | line 66 to the outer-diameter side.

  As described above, the resin M is held at the central portion on the molding surface 62 without reaching the inner peripheral surface 64 of the body mold 53 before the molding step. The resin M held in the center on the molding surface 62 is spread uniformly in the radial direction between the molding surface 60 of the upper mold 51 and the molding surface 62 of the lower mold 52 in the molding process. Thereby, the shape of both the molding surfaces 60 and 62 can be accurately transferred to the resin M.

  Preferably, in the supplying step, the lower mold 52 in contact with the resin M is cooled by an appropriate means such as blowing cold air to the lower mold 52, and the resin M is cooled through the lower mold 52. According to this, the viscosity of the resin M can be increased and the spread of the resin M can be further suppressed.

  FIG. 5 shows another example of a lens manufacturing apparatus. In addition, the same code | symbol is attached | subjected to the element which is common in the manufacturing apparatus 100 mentioned above, and description is abbreviate | omitted or simplified.

  The manufacturing apparatus 200 includes a mold 250, a resin supply unit 101, a drive unit 102, an energy supply unit 103, and a stop unit.

  The mold 250 is composed of an upper mold 251, a lower mold 252, and a body mold 253. The trunk mold 253 is formed in a cylindrical shape. The upper mold 251 includes a columnar main body 254 that is inserted into the body mold 253, and a flange 255 that is provided at the base end of the main body 254 and spreads around the main body 254. The flange portion 255 abuts on the upper end of the body mold 253 in the axial direction, and defines the amount of insertion of the main body section 254 into the body mold 253. Similarly, the lower mold 252 includes a columnar body portion 256 inserted into the body mold 253 and a flange portion 257 provided at the base end portion of the body portion 256 and spreading around the body portion 256 in a bowl shape. It is configured. The flange portion 257 is in contact with the lower end of the body mold 253 in the axial direction, and defines the amount of insertion of the main body section 256 into the body mold 253.

  The front end surface of the main body 254 of the upper mold 251 is a molding surface 260 and has a shape obtained by inverting either one of the front and back surface shapes of the first lens 20, and a substantially central portion of the molding surface 260 of the upper mold 251. Is provided with an optical surface molding portion 261 having a shape obtained by inverting one optical surface of the lens portion 30 of the first lens 20. The front end surface of the main body portion 256 of the lower mold 252 is also formed as a molding surface 262 and has a shape obtained by inverting the other surface shape of the front and back surfaces of the first lens 20. Is provided with an optical surface molding portion 263 having a shape obtained by inverting the other optical surface of the lens portion 30.

  On the molding surface 262 of the lower mold 252, a water repellent surface 266 is formed in an annular region surrounding the entire periphery of the optical surface molding part 263. The water repellent surface 266 can be formed by applying a rough surface process such as shot peening to the region of the molding surface 262 where the water repellent surface 266 is to be formed, and can also be formed by forming a water repellent film. can do. The water repellent film can be formed by applying a fluororesin such as polytetrafluoroethylene (PTFE) or perfluoroalkyl-containing silane (FAS) to the molding surface 266.

  The resin M supplied by the resin supply means 101 is deposited on the optical surface molding part 263 of the molding surface 262 of the lower mold 252, but naturally spreads around the optical surface molding part 263 and around the optical surface molding part 263. In contact with the water-repellent surface 266 surrounding the surface. The resin M in contact with the water repellent surface 266 exhibits a bulging shape that rises highly on the molding surface 262 due to its surface tension, and is prevented from spreading on the water repellent surface 266 to the outer diameter side.

  Thereby, the resin M is held at the center on the molding surface 262 without reaching the inner peripheral surface 264 of the body mold 253 before the molding step. The resin M held in the center on the molding surface 262 is spread uniformly in the radial direction between the molding surface 260 of the upper mold 251 and the molding surface 262 of the lower mold 252 in the molding process. Thereby, the shape of both the molding surfaces 260 and 262 can be accurately transferred to the resin M.

  As described above, the present specification includes a mold used for manufacturing a lens made of an energy curable resin, and includes an upper mold and a lower mold, and a cylinder surrounding the upper mold and the lower mold. The upper mold has a molding surface having a shape obtained by inverting the shape of one surface of the front and back surfaces of the lens, and the lower mold is formed on the other surface of the front and back surfaces of the lens. The molding surface of the lower mold has a molding surface that is an inverted shape, and the molding surface of the lower mold is provided at the center of the resin embedding portion and the resin embedding around the resin embedding portion. There is disclosed a mold having a stopper portion that suppresses the spread of the resin piled up on the raised portion.

  Moreover, the shaping | molding die disclosed by this specification is the protruding item | line with which the said stopper part protruded on the said shaping | molding surface.

  Further, in the mold disclosed in the present specification, the volume of the portion surrounded by the molding surface and the ridges is smaller than the volume of the lens.

  Moreover, as for the shaping | molding die disclosed by this specification, the said protruding item | line has a surface in the protrusion, and has an edge in the connection part of this protrusion surface and an internal peripheral surface.

  Moreover, as for the shaping | molding die disclosed by this specification, the said stopper part is a water-repellent surface.

  In the mold disclosed in the present specification, the water repellent surface is formed by subjecting the molding surface to a rough surface process.

  In the mold disclosed in this specification, the water repellent surface is formed by forming a water repellent film on the molded surface.

  Further, the present specification includes at least one of the above-described molding die, resin supply means for depositing an energy curable resin on the resin pile portion of the molding surface of the lower die, and at least the upper die and the lower die. Drive means for expanding and reducing the distance between the molding surface of the upper mold and the molding surface of the lower mold by moving one side, and is sandwiched between the molding surface of the upper mold and the molding surface of the lower mold whose distance is reduced And an energy supply means for supplying curing energy to the molded resin.

  In addition, the lens manufacturing apparatus disclosed in the present specification further includes a cooling unit that cools the resin piled up on the resin pile portion of the molding surface of the lower mold.

  In the lens manufacturing apparatus disclosed in this specification, the resin contains only one of a thermal polymerization initiator and a photopolymerization initiator.

  Further, the present specification discloses a lens manufactured by any of the above-described lens manufacturing apparatuses.

  Further, the present specification includes an imaging device including a solid-state imaging device and a lens unit that forms an image on a light receiving surface of the solid-state imaging device, wherein the lens unit includes at least one of the above-described lenses. An apparatus is disclosed.

DESCRIPTION OF SYMBOLS 1 Imaging device 2 Sensor 3 Lens unit 4 Optical system 5 Lens tube 10 Board | substrate 11 Solid-state image sensor 20 1st lens 21 2nd lens 30 Lens part 31 Edge part 32 Lens part 33 Edge part 34 Fitting part 35 Fitting part 36 Fitting Joint part 40 Cylinder part 41 Cover part 42 Base part 43 Holding member 44 Opening part 45 Fitting part 50 Molding die 51 Upper mold 52 Lower mold 53 Body mold 54 Body part 55 Flange part 56 Body part 57 Flange part 60 Molding surface 61 Optical Surface molding part 62 Molding surface 63 Optical surface molding part (resin pile part)
64 Inner peripheral surface 66 Projection (stopper)
DESCRIPTION OF SYMBOLS 100 Manufacturing apparatus 101 Resin supply means 102 Drive means 103 Energy supply means

Claims (8)

A mold used to manufacture a lens made of energy curable resin,
An upper mold and a lower mold, and a body mold surrounding the upper mold and the lower mold;
The upper mold has a molding surface having a shape obtained by reversing the shape of one of the front and back surfaces of the lens, and the lower mold has the shape of the other surface of the front and back surfaces of the lens reversed. Having a shaped molding surface,
On the molding surface of the lower mold, ridges are projected over the entire circumference along the edge of the molding surface ,
The volume of the part surrounded by the molding surface and the ridges is smaller than the volume of the lens,
The said protruding item | line is a shaping | molding die which has an edge in the connection part of a protrusion end surface and an internal peripheral surface, and suppresses the breadth of the said resin piled up on the molding surface of the said lower mold | type. A mold used to manufacture a lens made of energy curable resin,
An upper mold and a lower mold, and a body mold surrounding the upper mold and the lower mold;
The upper mold has a molding surface having a shape obtained by reversing the shape of one of the front and back surfaces of the lens, and the lower mold has the shape of the other surface of the front and back surfaces of the lens reversed. Having a shaped molding surface,
The molding surface of the lower mold is provided at a central portion of the resin deposit portion on which the resin is deposited, and the spread of the resin on the resin deposit portion provided around the resin deposit portion over the entire circumference is suppressed. And a stopper portion to
The said stopper part is a shaping | molding die which is a water-repellent surface. The mold according to claim 2 , wherein
The water repellent surface is a molding die formed by forming a water repellent film on the molding surface. The mold according to any one of claims 1 to 3 ,
A resin supply means for depositing an energy curable resin on the molding surface of the lower mold;
Driving means for moving at least one of the upper mold and the lower mold to expand or contract the interval between the molding surface of the upper mold and the molding surface of the lower mold;
Energy supply means for supplying curing energy to the resin molded by being sandwiched between the molding surface of the upper mold and the molding surface of the lower mold whose interval is reduced;
A lens manufacturing apparatus comprising: The lens manufacturing apparatus according to claim 4 ,
An apparatus for manufacturing a lens, further comprising cooling means for cooling the resin accumulated on the molding surface of the lower mold. The lens manufacturing apparatus according to claim 4 or 5 ,
The lens manufacturing apparatus, wherein the resin contains only one of a thermal polymerization initiator and a photopolymerization initiator. The lens manufactured with the manufacturing apparatus of the lens as described in any one of Claims 4-6 . An imaging apparatus comprising: a solid-state imaging device; and a lens unit that forms an image on a light receiving surface of the solid-state imaging device,
The image pickup apparatus including at least one lens according to claim 7 .

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