Coupling lens

Abstract

A bonded lens helps prevent deterioration in optical performance due to adhesive peeling. The bonded lens comprises a first lens and a second lens made of plastic bonded with an adhesive, wherein the refractive indexes of the first lens, the second lens, and the adhesive are ≥1.4 and ≤1.7, the region where the first lens is bonded to the second lens includes a concave lens surface and a peripheral region on the first lens side, and the region where the second lens is bonded to the first lens includes a convex lens surface and a peripheral region on the second lens side, and a single layer of a transparent material selected from the group consisting of SiO2, BaF2, S4F, S5F, YF3, LaF3, CeF3, NdF3, Al2O3, and OM‑4 is vapor-deposited on the region where the first lens is bonded to the second lens and / or the region where the second lens is bonded to the first lens.

Description

Technical Field

[0001] The present invention relates to a cemented lens, and more particularly to a cemented lens including a first lens and a second lens made of plastic and bonded together with an adhesive. Background Art

[0002] In the past, there was a cemented lens, such as Figure 4 As shown, it includes a first lens 14X made of plastic and a second lens 15X made of plastic bonded together with an adhesive PTX.

[0003] Specifically, if Figure 4 As shown, the area of the first lens 14X that is bonded to the second lens 15X includes a concave lens surface 141X and a first lens side peripheral area 142X that surrounds the concave lens surface 141X on the peripheral side, and the area of the second lens 15X that is bonded to the first lens 14X includes a convex lens surface 151X opposite to the concave lens surface 141X and a second lens side peripheral area 152X that surrounds the convex lens surface 151X on the peripheral side. In addition, in order to avoid deviation in the interval between the surfaces of the first lens 14X and the second lens 15X that are bonded to each other, a convex portion 153X that protrudes toward the first lens side peripheral area 142X and abuts against the first lens side peripheral area 142X is formed in the second lens side peripheral area 152X.

[0004] To manufacture the cemented lens, for example, adhesive PTX is first applied to the concave lens surface 141X of the first lens 14X and a portion of the first lens-side outer peripheral region 142X adjacent to the concave lens surface 141X. The concave lens surface 141X of the first lens 14X and the convex lens surface 151X of the second lens 15X are then brought closer together until the convex portion 153X of the second lens-side outer peripheral region 152X of the second lens 15X abuts the first lens-side outer peripheral region 142X of the first lens 14X. At this point, the adhesive PTX is squeezed and expanded to fill at least the effective diameter area of the cemented lens (corresponding to the concave lens surface 141X and the convex lens surface 151X) and a portion adjacent thereto. Ultraviolet light is then irradiated from the outside of either the first lens 14X or the second lens 15X, and the ultraviolet light that passes through the lens cures the adhesive, thereby cementing the first lens 14X and the second lens 15X together.

[0005] However, during the manufacturing process of the aforementioned bonded lens, when the adhesive is cured using ultraviolet light passing through the lenses, a shrinkage force is generated in the adhesive. If the bonding strength between the adhesive and the surfaces of the first and second lenses to be bonded together is insufficient to resist this shrinkage force, the adhesive will peel off from the surfaces of the first and second lenses to be bonded together, thereby creating a thin air layer between the surfaces of the adhesive and the first and second lenses to be bonded together, leading to problems such as lens failure or deterioration in optical performance.

[0006] In particular, since the bonding strength between the adhesive and plastic is weaker than the bonding strength between the adhesive and metal or glass, the above-mentioned cemented lens is prone to problems such as lens failure or degradation of optical performance.

[0007] Furthermore, in practice, due to factors such as storage conditions, the surfaces of the first and second lenses before bonding may sometimes oxidize or deteriorate due to weathering. This can cause the uncured adhesive to have poor affinity with the surfaces of the first and second lenses, making it difficult for the adhesive to adhere to the surfaces of the first and second lenses. In this case, problems such as lens failure or deterioration in optical performance may occur during the manufacture of the bonded lens. Summary of the Invention

[0008] The present invention is made to solve the above-mentioned problems, and an object of the present invention is to provide a cemented lens that helps to avoid problems such as lens failure or optical performance degradation caused by peeling of the adhesive.

[0009] In order to achieve the above-mentioned object, the present invention provides a joined lens comprising a first lens and a second lens made of plastic joined by an adhesive, wherein the refractive index of the first lens, the second lens, and the adhesive is ≥1.4 and ≤1.7, wherein the region of the first lens joined to the second lens includes a concave lens surface and a first lens-side peripheral region surrounding the concave lens surface on the outer peripheral side, and the region of the second lens joined to the first lens includes a convex lens surface opposite to the concave lens surface and a second lens-side peripheral region surrounding the convex lens surface on the outer peripheral side, and a single layer of transparent material layer is evaporated in the region of the first lens joined to the second lens and / or the region of the second lens joined to the first lens, wherein the transparent material layer is composed of at least one material selected from SiO2, BaF2, S4F, S5F, YF3, LaF3, CeF3, NdF3, Al2O3, and OM-4.

[0010] Here, the refractive index refers to the wavelength of the sodium D-ray. Furthermore, S4F and S5FOM-4 are commercially available materials manufactured by CANON OPTRON. The main components of S4F and S5F are SiO2 and Al2O3, while the main components of OM-4 are ZrO2 and Al2O3.

[0011] According to the cemented lens of the present invention, a single layer of transparent material is deposited in the region where the first lens is bonded to the second lens and / or in the region where the second lens is bonded to the first lens. The transparent material layer is composed of a material selected from the group consisting of SiO2, BaF2, S4F, S5F, YF3, LaF3, CeF3, NdF3, Al2O3, and OM-4. Therefore, even if the surfaces of the first lens and the second lens before bonding are oxidized or weather-resistant, the adhesive applied between the first lens and the second lens and the adhesive applied between the first lens and the second lens is not lost. When the adhesive between the lenses cures, the adhesive is not easily peeled off from the transparent material layer, and it is not easy for an unnecessary air layer to be generated between the first lens and the second lens due to the peeling of the adhesive. In addition, since the refractive index of SiO2, BaF2, S4F, S5F, YF3, LaF3, CeF3, NdF3, Al2O3, and OM-4 is ≥1.4 and ≤1.7, which is close to the refractive index of the first lens, the second lens, and the adhesive, it helps to avoid unnecessary reflections caused by the presence of the transparent material layer, and helps to avoid problems such as refraction.

[0012] Furthermore, in the cemented lens of the present invention, it is preferable that the transparent material layer is vapor-deposited on the concave lens surface and / or the convex lens surface.

[0013] The concave lens surface and the convex lens surface constitute the effective diameter area of the bonded lens. If an air layer is generated between the concave lens surface and the convex lens surface due to the peeling of the adhesive, it will seriously affect the optical performance of the bonded lens. According to the bonded lens of the present invention, by vapor-depositing a transparent material layer on the concave lens surface and / or the convex lens surface, it helps to avoid the generation of an air layer in the effective diameter area of the bonded lens due to the peeling of the adhesive.

[0014] Furthermore, in the cemented lens of the present invention, it is preferable that a convex portion that protrudes toward the other and contacts the other is formed on one of the first lens-side outer peripheral region and the second lens-side outer peripheral region.

[0015] According to the cemented lens of the present invention, it is possible to prevent the interval between the surfaces of the first lens and the second lens from being deviated from each other.

[0016] In the cemented lens having the above structure, a concave portion extending in the circumferential direction so as to surround the concave lens surface may be formed in the first lens side outer peripheral region, and the convex portion may be located on the outer peripheral side of the concave portion.

[0017] According to the cemented lens of the present invention, during manufacturing, even if a large amount of adhesive is applied to the concave lens surface of the first lens and / or the convex lens surface of the second lens, when the concave lens surface of the first lens and the convex lens surface of the second lens are brought close to each other and the convex portion in the second lens side peripheral region of the second lens abuts against the first lens side peripheral region of the first lens, the adhesive is squeezed and expands from the concave lens surface and the convex lens surface toward the peripheral side. The adhesive expanding toward the peripheral side can also be received by the concave portion and is not likely to leak out to the outside of the first lens and the second lens. Therefore, it is not likely to cause problems when assembling the cemented lens to other components due to the adhesive leaking out to the outside of the first lens and the second lens.

[0018] In addition, in the bonded lens of the above structure, the following structure can be adopted: the concave portion is separated from the concave lens surface, and the transparent material layer is evaporated in a first area of the first lens side peripheral area located between the concave portion and the concave lens surface and / or in a second area of the second lens side peripheral area corresponding to the first area.

[0019] When manufacturing a bonded lens, the adhesive is usually first applied mainly to the concave lens surface of the first lens (the convex lens surface of the second lens), and then the concave lens surface of the first lens and the convex lens surface of the second lens are brought close to each other so that the adhesive spreads from the concave lens surface and the convex lens surface toward the peripheral side. Therefore, the adhesive spread from the concave lens surface and the convex lens surface toward the peripheral side is likely to be peeled off from the surface of the first lens and the second lens during curing due to insufficient quantity, etc., and when the adhesive peels off in the above-mentioned first area and / or second area, the peeling is likely to spread to between the concave lens surface and the convex lens surface. In this regard, according to the bonded lens with the above-mentioned structure, by vapor-depositing a transparent material layer in the above-mentioned first area and / or second area, it helps to avoid the adhesive peeling off in the above-mentioned first area and / or second area, and avoid the adhesive peeling off in the above-mentioned first area and / or second area from spreading to between the concave lens surface and the convex lens surface and seriously affecting the optical performance of the bonded lens.

[0020] In particular, due to the presence of the above-mentioned recess, the adhesive extending from the concave lens surface and the convex lens surface toward the outer peripheral side easily flows into the recess, causing the adhesive to peel off from the surface side of the second lens opposite to the above-mentioned recess. Therefore, by vapor-depositing the transparent material layer in the second area, it helps to reliably prevent the adhesive peeling generated in the above-mentioned first area and / or second area from spreading to between the concave lens surface and the convex lens surface, thereby seriously affecting the optical performance of the bonded lens.

[0021] Furthermore, in the cemented lens of the present invention, it is preferable that the distance between the concave lens surface and the convex lens surface is ≥1 μm and ≤20 μm.

[0022] According to the cemented lens of the present invention, it is possible to facilitate complete filling of the adhesive between the concave lens surface and the convex lens surface.

[0023] Furthermore, in the cemented lens having the above structure, the following structure may be adopted: the interval between the first region and the second region is ≥20 μm and ≤50 μm.

[0024] The cemented lens of the present invention helps to prevent burrs generated during the molding of the first lens (second lens) from contacting the second lens (first lens) when the first lens and the second lens are brought close together, thereby damaging the second lens (first lens), generating debris, and affecting the optical performance of the cemented lens.

[0025] (Effects of the Invention)

[0026] According to the present invention, a single layer of transparent material is deposited on the region where the first lens is bonded to the second lens and / or on the region where the second lens is bonded to the first lens. The transparent material layer is composed of a material selected from the group consisting of SiO2, BaF2, S4F, S5F, YF3, LaF3, CeF3, NdF3, Al2O3, and OM-4. Therefore, even if the surfaces of the first and second lenses before bonding are oxidized or weather-resistant, the adhesive applied between the first and second lenses and the adhesive applied between the first and second lenses are not damaged. When the adhesive between the first and second lenses cures, the adhesive is unlikely to peel off from the transparent material layer, and an unnecessary air layer is unlikely to be generated between the first and second lenses due to adhesive peeling. Furthermore, since the refractive index of SiO2, BaF2, S4F, S5F, YF3, LaF3, CeF3, NdF3, Al2O3, and OM-4 is ≥1.4 and ≤1.7, which is close to the refractive index of the first and second lenses and the adhesive, it helps to avoid unnecessary reflections and other problems caused by the presence of the transparent material layer, and helps to avoid problems such as refraction. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a side sectional view schematically showing the entire structure of a lens unit including the cemented lens of the present invention.

[0028] Figure 2 It is a side sectional view schematically showing the structure of the cemented lens of the present invention.

[0029] Figure 3 This is a diagram schematically showing the coating region of the transparent material layer of the first lens and the second lens included in the cemented lens of the present invention.

[0030] Figure 4 It is a side sectional view schematically showing the structure of a conventional cemented lens.

[0031] (Explanation of Symbols)

[0032] 1 lens unit

[0033] 11 Lens

[0034] 12 lenses

[0035] 13 Lens

[0036] 14. First lens

[0037] 141 Concave lens surface

[0038] 142 First lens side peripheral area

[0039] 15 Second lens

[0040] 151 convex lens surface

[0041] 152 Second lens side peripheral area

[0042] 20 Lens tube

[0043] 21 cylindrical main body

[0044] 211 Trail Section

[0045] 212 first middle diameter part

[0046] 213 Second middle diameter part

[0047] 214 third middle diameter part

[0048] 215 Large diameter part

[0049] 22 annular flange

[0050] 23 annular protrusion

[0051] 24 annular bottom plate

[0052] 30 Infrared filter

[0053] PT adhesive

[0054] PM1, PM2 transparent material layer DETAILED DESCRIPTION

[0055] Hereinafter, embodiments of a lens unit including a cemented lens according to the present invention will be described with reference to the accompanying drawings.

[0056] In the following description, "object side L1" and "image side L2" refer to the object side (sometimes also referred to as the front side hereinafter) and the image side (sometimes also referred to as the rear side hereinafter) in the direction of the optical axis L, and "optical axis direction" refers to the direction parallel to the optical axis L.

[0057] Figure 1is a side sectional view schematically showing the overall structure of a lens unit including a cemented lens of the present invention, Figure 2 is a side sectional view schematically showing the structure of the cemented lens of the present invention, Figure 3 This is a diagram schematically showing the coating region of the transparent material layer of the first lens and the second lens included in the cemented lens of the present invention.

[0058] like Figure 1 As shown, the lens unit 1 includes a plurality of lenses arranged along the optical axis direction and a lens barrel 20 that holds the plurality of lenses.

[0059] Here, the lens unit 1 includes five lenses arranged along the optical axis, namely, lens 11, lens 12, lens 13, first lens 14 and second lens 15, from the object side L1, wherein the first lens 14 and the second lens 15 constitute the cemented lens of the present invention; and a light shielding plate (not shown) is provided between the lens 12 and the lens 13, an aperture (not shown) is provided between the lens 13 and the first lens 14, and an infrared filter 30 and a shooting element (not shown) are arranged at a position closer to the image side L2 than the second lens 15. Specifically, lens 11 has negative power, with its object-side L1 surface being convex and its image-side L2 surface (the center thereof) being concave; lens 12 has negative power, with its object-side L1 surface being substantially planar and its image-side L2 surface (the center thereof) being concave; lens 13 has positive power, with its object-side L1 surface (the center thereof) being convex and its image-side L2 surface being convex; first lens 14 has negative power, with its object-side L1 surface (the center thereof) being concave and its image-side L2 surface (the center thereof) also being concave; and second lens 15 has positive power, with its object-side L1 surface (the center thereof) being convex and its image-side L2 surface (the center thereof) also being convex. Furthermore, lens 11 is made, for example, of glass, and lenses 12, 13, first lens 14, and second lens 15 are all made, for example, of plastic, but this is not limiting. Appropriate materials may be selected as needed to manufacture lenses 11, 12, 13, first lens 14, and second lens 15.

[0060] In addition, the lens barrel 20 is made of, for example, resin, and includes a cylindrical main body 21 extending in the optical axis direction, an annular flange portion 22 whose diameter expands radially outward from the front end of the cylindrical main body 21 (i.e., the end on the object side L1), an annular protrusion 23 protruding from the front end of the cylindrical main body 21 toward the object side L1, and an annular bottom plate portion 24 protruding radially inward from the vicinity of the rear end of the cylindrical main body 21 (i.e., the end on the image side L2). In addition, on the inner circumferential surface of the cylindrical main body 21, a small-diameter portion 211, a first middle-diameter portion 212 having an inner diameter larger than that of the small-diameter portion 211, a second middle-diameter portion 213 having an inner diameter larger than that of the first middle-diameter portion 212, a third middle-diameter portion 214 having an inner diameter larger than that of the second middle-diameter portion 213, and a large-diameter portion 215 having an inner diameter larger than that of the third middle-diameter portion 214 are formed in this order from the image side L2 toward the object side L1. The rear end of the small-diameter portion 211 is connected to the annular bottom plate portion 24.

[0061] In addition, the rear end face of the second lens 15 abuts the front end face of the annular bottom plate portion 24, and the outer peripheral surface of the second lens 15 is separated from the small diameter portion 211; the rear end face of the first lens 14 abuts the step portion between the small diameter portion 211 and the first medium diameter portion 212, and the outer peripheral surface of the rear end side of the first lens 14 abuts the inner peripheral surface of the first medium diameter portion 212; the rear end face of the lens 13 abuts the front end face of the first lens 14, and the outer peripheral surface of the rear end side of the lens 13 abuts the inner peripheral surface of the second medium diameter portion 213; the rear end face of the lens 12 abuts the front end face of the lens 13, and the outer peripheral surface of the rear end side of the lens 12 abuts the inner peripheral surface of the third medium diameter portion 214; the rear end face of the lens 11 abuts the front end face of the lens 12, and the outer peripheral surface of the lens 11 abuts the inner peripheral surface of the large diameter portion 215. The front end of the annular protrusion 23 is riveted radially inward and abuts against the lens 11 from the object side L1.

[0062] Furthermore, in the lens barrel 20 , the infrared filter 30 is held on the rear end surface of the annular bottom plate portion 24 .

[0063] In addition, if Figure 2As shown, the region of the first lens 14 that is bonded to the second lens 15 includes a concave lens surface 141 and a first lens-side peripheral region 142 that peripherally surrounds the concave lens surface 141. The region of the second lens 15 that is bonded to the first lens 14 includes a convex lens surface 151 that opposes the concave lens surface 141, and a second lens-side peripheral region 152 that peripherally surrounds the convex lens surface 151 and opposes the first lens-side peripheral region 142. Furthermore, a convex portion 153 is formed within the second lens-side peripheral region 152, projecting toward the first lens-side peripheral region 142 and abutting against it. A concave portion 143 (which may be formed continuously or intermittently along the circumference) is formed within the first lens-side peripheral region 142, extending circumferentially so as to surround the concave lens surface 141. The convex portion 153 is located on the outer circumference of the concave portion 143. Furthermore, the recess 143 is separated from the concave lens surface 141 (in a direction perpendicular to the optical axis), the first lens side peripheral region 142 has a first region 144 between the recess 143 and the concave lens surface 141, and the second lens side peripheral region 152 has a second region 154 corresponding to the first region 144.

[0064] Here, it is preferable that the distance between the concave lens surface 141 and the convex lens surface 151 is ≥1 μm and ≤20 μm, and the distance between the first region 144 and the second region 154 is ≥20 μm and ≤50 μm.

[0065] In addition, if Figure 2 As shown, the first lens 14 and the second lens 15 are bonded to each other using an adhesive PT (for example, an acrylic ultraviolet curing adhesive).

[0066] Here, the refractive index of the first lens 14 , the second lens 15 , and the adhesive PT (ie, the wavelength of the sodium light D-ray) is ≥1.4 and ≤1.7.

[0067] In addition, if Figure 3 As shown, single-layer transparent material layers PM1 and PM2 are evaporated in the area where the first lens 14 is joined to the second lens 15 and in the area where the second lens 15 is joined to the first lens 14. The transparent material layers PM1 and PM2 are preferably composed of materials selected from SiO2, BaF2, S4F, S5F, YF3, LaF3, CeF3, NdF3, Al2O3, and OM-4.

[0068] Here, a transparent material layer PM1 is vapor-deposited on the concave lens surface 141 of the first lens 14 and in an area approximately half of the concave lens surface 141 to the concave portion 143, and a transparent material layer PM2 is vapor-deposited on the convex lens surface 151 of the second lens 15 and in an area corresponding to approximately half of the concave portion 143.

[0069] Hereinafter, an example of a method for producing a cemented lens of the present invention will be described.

[0070] First, a transparent material layer PM1 is evaporated on the concave lens surface 141 of the first lens 14 and in an area approximately half of the concave lens surface 141 to the concave portion 143, and a transparent material layer PM2 is evaporated on the convex lens surface 151 of the second lens 15 and in an area corresponding to approximately half of the concave portion 143.

[0071] Next, the adhesive PT is applied to the concave lens surface 141 of the first lens 14 and a portion of the first lens-side outer peripheral region 142 adjacent to the concave lens surface 141 .

[0072] Then, the concave lens surface 141 of the first lens 14 and the convex lens surface 151 of the second lens 15 are brought closer together until the convex portion 153 of the second lens-side outer peripheral region 152 of the second lens 15 abuts the first lens-side outer peripheral region 142 of the first lens 14. At this time, the adhesive is squeezed and expanded to fill at least the effective diameter area of the cemented lens and a portion adjacent thereto.

[0073] Finally, ultraviolet rays are irradiated from the outside of the first lens 14 or the second lens 15 , and the adhesive PT is cured by the ultraviolet rays that pass through the lens, thereby bonding the first lens 14 and the second lens 15 together.

[0074] According to the cemented lens of this embodiment, single-layer transparent material layers PM1 and PM2 are vapor-deposited in the region where the first lens 14 is bonded to the second lens 15 and in the region where the second lens 15 is bonded to the first lens 14. The transparent material layers PM1 and PM2 are composed of a material selected from SiO2, BaF2, S4F, S5F, YF3, LaF3, CeF3, NdF3, Al2O3, and OM-4. Therefore, even if the surfaces of the first lens and the second lens before bonding are oxidized or weather-resistant, the adhesive PT is applied between the first lens 14 and the second lens 15 and the adhesive is applied between the first lens 14 and the second lens 15. When the adhesive PT between the mirrors 15 is cured, the adhesive PT is not easy to peel off from the transparent material layers PM1 and PM2, and it is not easy to generate an unnecessary air layer between the first lens 14 and the second lens 15 due to the peeling of the adhesive PT. In addition, since the refractive index of SiO2, BaF2, S4F, S5F, YF3, LaF3, CeF3, NdF3, Al2O3, and OM-4 is ≥1.4 and ≤1.7, which is close to the refractive index of the first lens 14, the second lens 15 and the adhesive PT, it helps to avoid unnecessary reflections due to the presence of the transparent material layers PM1 and PM2, and helps to avoid problems such as refraction.

[0075] In particular, according to the cemented lens of this embodiment, when the first lens 14 is made of PC AD5503 manufactured by TEIJIN and the second lens 15 is made of E48R manufactured by ZEONEX, by vapor-depositing single-layer transparent material layers PM1 and PM2 composed of SiO2 in the area where the first lens 14 is bonded to the second lens 15 and in the area where the second lens 15 is bonded to the first lens 14, it can be confirmed that the bonding strength of the adhesive at the concave lens surface 141 of the first lens 14 (and its surrounding area) and the convex lens surface 151 of the second lens 15 (and its surrounding area) is significantly enhanced, compared with the case where the transparent material layer is not vapor-deposited in the area where the first lens 14 is bonded to the second lens 15 and in the area where the second lens 15 is bonded to the first lens 14. Specifically, the adhesive has good affinity with the transparent material layer in its uncured state, rarely failing to adhere. No adhesive peeling occurred within the concave lens surface 141 of the first lens 14 or the convex lens surface 151 of the second lens 15. Within the first region 144 and the second region 154, peeling rates were reduced from 30% to 0.1%. Furthermore, when using a transparent material layer composed of SiO2, since SiO2 is a stable material with little degradation in weather resistance, the SiO2-deposited bonding surface is less susceptible to oxidation and weathering degradation, ensuring stable adhesive adhesion. Furthermore, due to its low price, using a transparent material layer composed of SiO2 also helps reduce manufacturing costs.

[0076] Furthermore, according to the cemented lens of this embodiment, the transparent material layer is deposited on the concave lens surface 141 and the convex lens surface 151 , thereby helping to prevent the formation of an air layer within the effective diameter region of the cemented lens due to peeling of the adhesive PT.

[0077] Furthermore, according to the cemented lens of this embodiment, a concave portion 143 extending in the circumferential direction so as to surround the concave lens surface 141 is formed in the first lens side outer peripheral region 142, and the convex portion 153 is closer to the outer peripheral side than the concave portion 143. Therefore, during manufacturing, even if a large amount of adhesive PT is applied to the concave lens surface 141 of the first lens 14, when the concave lens surface 141 of the first lens 14 and the convex lens surface 151 of the second lens 15 are brought closer together and the second lens side outer peripheral region 142 of the second lens 15 is formed, the convex portion 153 is closer to the outer peripheral side than the concave portion 143. When the convex portion 153 in the area 152 abuts against the first lens side peripheral area 142 of the first lens 14, the adhesive PT is squeezed and expands from the concave lens surface 141 and the convex lens surface 151 toward the peripheral side. The adhesive PT expanding toward the peripheral side can also be accommodated by the concave portion 143 and is not likely to leak out to the outside of the first lens 14 and the second lens 15. Therefore, it is not likely to cause problems when assembling the bonded lens to other components due to the adhesive leaking out to the outside of the first lens 14 and the second lens 15.

[0078] In addition, according to the bonding lens of this embodiment, by evaporating a transparent material layer in the above-mentioned first area 144 and second area 154, it helps to avoid the peeling of the adhesive in the first area 144 and second area 154, and avoids the peeling of the adhesive in the first area 144 and second area 154 from spreading to between the concave lens surface 141 and the convex lens surface 151 and seriously affecting the optical performance of the bonding lens.

[0079] Furthermore, according to the cemented lens of this embodiment, the interval between the concave lens surface 141 and the convex lens surface 151 is ≥1 μm and ≤20 μm, which helps ensure that the adhesive is completely filled between the concave lens surface 141 and the convex lens surface 151 .

[0080] In addition, according to the cemented lens of this embodiment, the interval between the first region 144 and the second region 154 is ≥20μm and ≤50μm, which helps to avoid burrs generated during the molding of the first lens 14 (second lens 15) from contacting the second lens 15 (first lens 14) when the first lens 14 and the second lens 15 are brought close to each other, thereby damaging the second lens 15 (first lens 14), generating debris, and affecting the optical performance of the cemented lens.

[0081] The present invention is described above by way of example with reference to the accompanying drawings. It is apparent that the specific implementation of the present invention is not limited to the above-mentioned embodiments.

[0082] For example, in the above embodiment, the lens unit includes five lenses arranged along the optical axis, but the present invention is not limited thereto. The number of lenses can be adjusted as needed, and the shape of each lens included in the lens unit can also be adjusted as needed.

[0083] Furthermore, in the above embodiment, the recess 143 extending in the circumferential direction so as to surround the concave lens surface 141 is formed in the first lens side outer peripheral region 142 . However, the present invention is not limited thereto and the recess 143 may be omitted depending on circumstances.

[0084] Furthermore, in the above embodiment, the second lens-side peripheral region 152 is provided with a convex portion 153 that protrudes toward the first lens-side peripheral region 142 and abuts against the first lens-side peripheral region 142. However, the present invention is not limited thereto. Instead of the convex portion 153, a convex portion that protrudes toward the second lens-side peripheral region 152 and abuts against the second lens-side peripheral region 152 may be formed in the first lens-side peripheral region 142. Of course, the convex portion may be omitted depending on circumstances.

[0085] In addition, in the above embodiment, a transparent material layer PM1 is evaporated on the concave lens surface 141 of the first lens 14 and in an area approximately half of the concave portion 143 from the concave lens surface 141, and a transparent material layer PM2 is evaporated on the convex lens surface 151 of the second lens 15 and in an area corresponding to approximately half of the concave portion 143 from the convex lens surface 151. However, this is not limited to this. The evaporation range of the transparent material layer can be appropriately adjusted as needed. For example, the transparent material layer can be evaporated only on the concave lens surface 141 of the first lens 14 (and / or the convex lens surface 151 of the second lens 15), or the transparent material layer can be evaporated on the concave lens surface 141 of the first lens 14 and the first area 144 (and / or the convex lens surface 151 of the second lens 15 and the second area 154).

Claims

1. A cemented lens comprising a first lens and a second lens made of plastic bonded together by an adhesive, wherein the refractive index of the first lens, the second lens, and the adhesive is ≥1.4 and ≤1.7, wherein: The region of the first lens bonded to the second lens includes a concave lens surface and a first lens-side peripheral region surrounding the concave lens surface on the peripheral side. The area of the second lens bonded to the first lens includes a convex lens surface facing the concave lens surface and a second lens-side peripheral area surrounding the convex lens surface on the peripheral side. A single layer of transparent material is evaporated in the area where the first lens is bonded to the second lens and in the area where the second lens is bonded to the first lens. The transparent material layer is composed of a material selected from SiO2, BaF2, S4F, S5F, YF3, LaF3, CeF3, NdF3, Al2O3, and OM-4.

2. The cemented lens according to claim 1, wherein The transparent material layer is evaporated on the concave lens surface and / or the convex lens surface.

3. The cemented lens according to claim 1, wherein A convex portion is formed on one of the first lens side outer peripheral region and the second lens side outer peripheral region so as to protrude toward the other and come into contact with the other.

4. The cemented lens according to claim 3, wherein A concave portion extending in the circumferential direction so as to surround the concave lens surface is formed in the first lens side outer peripheral region. The convex portion is located on the outer peripheral side of the concave portion.

5. The cemented lens according to claim 4, wherein The concave portion is separated from the concave lens surface, The transparent material layer is vapor-deposited in a first region of the first lens-side peripheral region located between the recess and the concave lens surface and / or in a second region of the second lens-side peripheral region corresponding to the first region.

6. The cemented lens according to claim 1, wherein The distance between the concave lens surface and the convex lens surface is ≥1 μm and ≤20 μm.

7. The cemented lens according to claim 5, wherein The interval between the first region and the second region is ≥20 μm and ≤50 μm.

Images