Lens unit, imaging unit, and electronic device

Abstract

A lens unit including a plurality of lens elements arranged in order from the object side to the image side, wherein the Abbe number of the lens element closest to the image side among the plurality of lens elements is 37.0 to 48.0 inclusive.

Description

Lens unit, imaging unit and electronic device

[0001] The present invention relates to a lens unit, an imaging unit, and an electronic device.

[0002] In recent years, wide-angle and high-resolution lenses have been required for cameras used in surveillance cameras, in-vehicle cameras, cameras for mobile devices, etc. Therefore, lens units combining multiple lens elements to achieve wider angles and higher resolutions have been studied.

[0003] Patent Document 1 describes a lens system having a horizontal angle of view of 130° or more and a five-group, six-lens configuration, in which the first lens element from the object side is a plastic or glass lens with a convex surface facing the object side and a concave surface facing the image side and having negative power, the second lens element from the object side is a plastic lens with a concave surface facing the image side and having negative power, and at least one of the lens surfaces on the object side and the image side is aspherical, and the third lens element from the object side is a plastic lens with a concave surface facing the object side and having negative power, and at least one of the lens surfaces on the object side and the image side is aspherical. and a fourth lens element, which is the fourth lens element from the object side, is a plastic or glass lens element having a convex surface facing the image side and having a positive power, and a fifth lens element, which is the fifth lens element from the object side, and a sixth lens element, which is the sixth lens element from the object side, are both plastic lenses and form a cemented lens element having a positive power, and an aperture is disposed between the fourth lens element and the cemented lens element, and where an effective focal length is f and a focal length of the third lens element is f3, the effective focal length f and the focal length f3 satisfy |f / f3|<0.2. Furthermore, Patent Document 1 also describes that an object of the invention described in Patent Document 1 is to provide a wide-angle lens element in which the first lens element is a meniscus lens element having a lens shape that is easy to manufacture and in which aberrations can be further improved, even when an angle of view of 130° or more is ensured.

[0004] JP 2015-34922 A

[0005] The present invention provides a lens unit that can improve field curvature.

[0006] According to the present invention, there are provided a lens unit, an imaging unit, and an electronic device as described below.

[0007] 1. A lens unit comprising, in order from the object side to the image side, a plurality of lens elements, wherein of the plurality of lens elements, the lens element closest to the image side has an Abbe number of 37.0 or greater and 48.0 or less. 2. The lens unit described in 1., wherein the lens unit has: a front group LF on the object side including a plurality of lens elements that are close to each other or cemented together; and a rear group LR between the front group LF and the image including a plurality of lens elements, wherein the rear group LR includes every other lens element having an Abbe number of 37.0 or greater and 48.0 or less. 3. The lens unit described in 1. or 2., wherein the lens unit has: a front group LF on the object side including a plurality of lens elements that are close to each other or cemented together; and a rear group LR between the front group LF and the image including a plurality of lens elements, wherein the rear group LR includes every other lens element having an Abbe number of 37.0 or greater and 48.0 or less. 4. The lens unit described in any of 1. to 3., wherein the plurality of lens elements comprise, in this order from the object side to the image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element, and a seventh lens element, wherein the Abbe number of the fifth lens element is 37.0 or more and 48.0 or less, and the Abbe number of the seventh lens element is 37.0 or more and 48.0 or less. 5. The lens unit described in 4., wherein the Abbe number of the fifth lens element is 37.0 or more and 48.0 or less, and the Abbe number of the seventh lens element is 40.0 or more and 48.0 or less. 6. The lens unit described in 4. or 5., wherein the Abbe number of the seventh lens element is larger than the Abbe number of the fifth lens element. 7. The Abbe number of the second lens element, the Abbe number of the third lens element, and the Abbe number of the sixth lens element are smaller than the Abbe number of the fifth lens element. 8. The lens unit according to any one of 4. to 7., wherein the Abbe number of the second lens element, the Abbe number of the third lens element, and the Abbe number of the sixth lens element are smaller than the Abbe number of the seventh lens element.9. The lens unit described in any one of 4. to 8., wherein the first lens element has positive refractive power, the second lens element has positive refractive power, the third lens element has negative refractive power, the fourth lens element has positive refractive power, the fifth lens element has positive refractive power, the sixth lens element has negative refractive power, and the seventh lens element has positive refractive power. 10. The lens unit described in any one of 1. to 9., wherein the plurality of lens elements include one or more aspherical lens elements. 11. The lens unit described in any one of 1. to 10., wherein the lens element having an Abbe number of 37.0 or more and 48.0 or less comprises a cyclic olefin-based polymer having a structural unit derived from a cyclic olefin as an essential structural unit. 12. The lens unit described in 11., wherein the cyclic olefin-based polymer comprises a cyclic olefin-based copolymer (P) having a structural unit derived from a cyclic olefin as an essential structural unit. 13. The lens unit according to 12., wherein the cyclic olefin copolymer (P) comprises a structural unit (A) derived from an α-olefin having 2 to 20 carbon atoms, a structural unit (B) derived from a cyclic olefin having no aromatic ring, and a structural unit (C) derived from a cyclic olefin having an aromatic ring. 14. The lens unit according to 13., wherein, when the total content of the structural units (A), (B), and (C) in the cyclic olefin copolymer (P) is taken as 100 mol %, the content of the structural unit (A) in the cyclic olefin copolymer (P) is 10 mol % or more and 80 mol % or less. 15. The lens unit according to 13. or 14., wherein, when the total content of the structural units (B) and (C) in the cyclic olefin copolymer (P) is taken as 100 mol %, the content of the structural unit (C) in the cyclic olefin copolymer (P) is 5 mol % or more and 95 mol % or less. 16. 16. The lens unit according to any one of 13. to 15., wherein the cyclic olefin having no aromatic ring includes a compound represented by the following formula (B-1): (In the formula (B-1), n ​​is 0 or 1, m is 0 or a positive integer, q is 0 or 1, and R １ ~R １８ and R ａ and R ｂare each independently a hydrogen atom, a halogen atom, or a hydrocarbon group optionally substituted with a halogen atom, and R １５ ~R １８ may be bonded to each other to form a monocyclic or polycyclic ring, and the monocyclic or polycyclic ring may have a double bond, and R １５ and R １６ With or R １７ and R １８ and may form an alkylidene group, provided that the aromatic ring is not included.) 17. The lens unit described in any of 13. to 16., wherein the cyclic olefin having an aromatic ring includes one or more compounds selected from the group consisting of compounds represented by the following formula (C-1), compounds represented by the following formula (C-2), and compounds represented by the following formula (C-3): (In the above formula (C-1), n ​​and q each independently represent 0, 1, or 2; R １ ~R １７ are each independently a hydrogen atom, a halogen atom other than a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom other than a fluorine atom, and R １０ ~R １７ One of them is a bond, and when q=0, R １０ and R １１ , R １１ and R １２ , R １２ and R １３ , R １３ and R １４ , R １４ and R １５ , R １５ and R １０ may be bonded to each other to form a monocyclic or polycyclic ring, and when q=1 or 2, R １０ and R １１ , R １１ and R １７ , R １７ and R １７ , R １７ and R １２ , R １２ and R １３ , R １３ and R １４ , R １４ and R １５ , R １５and R １６ , R １６ and R １６ , R １６ and R １０ may be bonded to each other to form a monocycle or a polycycle, and the monocycle or the polycycle may have a double bond, or the monocycle or the polycycle may be an aromatic ring. (In the above formula (C-2), n and m are each independently 0, 1, or 2, q is 1, 2, or 3, and R １８ ~R ３１ are each independently a hydrogen atom, a halogen atom other than a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom other than a fluorine atom, and when q=1, R ２８ and R ２９ , R ２９ and R ３０ , R ３０ and R ３１ may be bonded to each other to form a monocyclic or polycyclic ring, and when q=2 or 3, R ２８ and R ２８ , R ２８ and R ２９ , R ２９ and R ３０ , R ３０ and R ３１ , R ３１ and R ３１ may be bonded to each other to form a monocycle or a polycycle, the monocycle or the polycycle may have a double bond, or the monocycle or the polycycle may be an aromatic ring. (In the above formula (C-3), q is 1, 2 or 3, and R ３２ ~R ３９ are each independently a hydrogen atom, a halogen atom other than a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom other than a fluorine atom, and when q=1, R ３６ and R ３７ , R ３７ and R ３８ , R ３８ and R ３９ may be bonded to each other to form a monocyclic or polycyclic ring, and when q=2 or 3, R ３６ and R ３６ , R３６ and R ３７ , R ３７ and R ３８ , R ３８ and R ３９ , R ３９ and R ３９ may be bonded to each other to form a monocycle or a polycycle, and the monocycle or the polycycle may have a double bond, and the monocycle or the polycycle may be an aromatic ring.) 18. The lens unit described in any of 13. to 17., wherein the cyclic olefin having an aromatic ring includes one or more selected from the group consisting of benzonorbornadiene, indenenorbornene, and methylphenylnorbornene. 19. An imaging unit comprising the lens unit described in any of 1. to 18. and an image sensor. 20. An electronic device comprising the imaging unit described in 19.

[0008] According to the present invention, it is possible to provide a lens unit, an imaging unit, and an electronic device that can improve field curvature.

[0009] FIG. 1 is a cross-sectional view schematically showing an example of a lens unit of this embodiment and a lens unit of Example 1. FIG. 2 is a cross-sectional view schematically showing an example of an imaging unit of this embodiment and an imaging unit of Example 1. FIG. 3 is a cross-sectional view schematically showing a path of a light ray relative to the imaging unit of Example 1. FIG. 4 is a diagram showing a chromatic aberration curve of the lens unit of Example 1. FIG. 5 is a diagram showing a chromatic aberration curve of the lens unit of Example 2. FIG. 6 is a diagram showing a chromatic aberration curve of the lens unit of Example 3. FIG. 7 is a diagram showing a chromatic aberration curve of the lens unit of Comparative Example 1. FIG. 8 is a diagram showing a field curvature curve of the lens unit of Example 1. FIG. 9 is a diagram showing a field curvature curve of the lens unit of Example 2. FIG. 10 is a diagram showing a field curvature curve of the lens unit of Example 3. FIG. 11 is a diagram showing a field curvature curve of the lens unit of Comparative Example 1.

[0010] The lens unit, imaging unit, and electronic device according to the present embodiment will be described in detail below, but the present invention is not limited to the following embodiment and can be implemented with appropriate modifications within the scope of the object of the present invention. In the present embodiment, the expressions "XX or more and YY or less" and "XX to YY" representing a numerical range mean a numerical range including the lower and upper limits, which are the endpoints, unless otherwise specified. When a numerical range is described in stages, the upper and lower limits of each numerical range can be combined arbitrarily. Furthermore, each monomer constituting the cyclic olefin polymer according to the present embodiment may be a monomer obtained from fossil raw materials, or a monomer obtained from animal or plant raw materials.

[0011] 1. Lens Unit The lens unit of this embodiment will now be described.

[0012] The lens unit of this embodiment is a lens unit that includes a plurality of lens elements arranged in order from the object side to the image side, and of the plurality of lens elements, the lens element closest to the image side has an Abbe number of 37.0 or more and 48.0 or less.

[0013] Although the mechanism by which the lens unit of this embodiment can improve field curvature is not clear, the inventors speculate on the following mechanism. First, to improve field curvature, it is common to combine lens elements with appropriate Abbe numbers. However, with conventional lens elements made of optical resin, the Abbe numbers that can be selected are either large, at 50 or greater, or small, at 35 or less. On the other hand, with the lens unit of this embodiment, the Abbe number of the lens element closest to the image side is 37.0 or greater and 48.0 or less, and it is speculated that this contributes to the improvement of field curvature in this embodiment.

[0014] The Abbe number of a lens element is an index for evaluating the chromatic dispersion of the lens element (change in refractive index with wavelength). The Abbe number (ν) of a lens element can be calculated using the following formula from the refractive indices of the lens element at wavelengths of 486 nm, 589 nm, and 656 nm at an ambient temperature of 23°C, which are obtained by measuring the lens element in accordance with ASTM D542: ν=(nD-1) / (nF-nC), where nD: refractive index at a wavelength of 589 nm, nC: refractive index at a wavelength of 656 nm, and nF: refractive index at a wavelength of 486 nm.

[0015] The lens unit of this embodiment is preferably a lens unit including a resin lens, more preferably a small wide-angle lens unit including a resin lens, and even more preferably a small wide-angle lens unit centered around a resin lens.

[0016] From the viewpoint of further improving chromatic aberration of the lens unit of this embodiment and further improving field curvature of the lens unit of this embodiment, the Abbe number of the lens element closest to the image side is preferably 37.2 or greater, more preferably 37.4 or greater, even more preferably 37.5 or greater, even more preferably 40.0 or greater, even more preferably 41.0 or greater, even more preferably 43.0 or greater, and preferably 47.0 or less, more preferably 46.0 or less, even more preferably 45.0 or less, and preferably 37.2 or greater and 47.0 or less, more preferably 37.4 or greater and 46.0 or less, even more preferably 37.5 or greater and 45.0 or less, even more preferably 40.0 or greater and 45.0 or less, even more preferably 41.0 or greater and 45.0 or less, and even more preferably 43.0 or greater and 45.0 or less.

[0017] In the lens unit of this embodiment, from the viewpoint of further improving chromatic aberration and further improving field curvature of the lens unit of this embodiment, preferably the lens unit has, on the object side, a front group LF including a plurality of lens elements that are close to or cemented together, and a rear group LR including a plurality of lens elements between the front group LF and the image, and the rear group LR includes every other lens element having an Abbe number of 37.0 or greater and 48.0 or less.

[0018] In the lens unit of this embodiment, from the viewpoint of further improving chromatic aberration and further improving field curvature of the lens unit of this embodiment, preferably the lens unit has, on the object side, a front group LF including a plurality of lens elements that are close to or cemented together, and a rear group LR including a plurality of lens elements between the front group LF and the image, and the rear group LR includes every other lens element having an Abbe number of 37.0 or more and 48.0 or less, and every other lens element having an Abbe number of 40.0 or more and 48.0 or less.

[0019] An example of a lens unit according to this embodiment will be described below with reference to Fig. 1. Lens unit 10 shown in Fig. 1 includes a plurality of lens elements, arranged in this order from the object side to the image side, as a first lens element 110, a second lens element 120, a third lens element 130, a fourth lens element 140, a fifth lens element 150, a sixth lens element 160, and a seventh lens element 170.

[0020] In the lens unit of this embodiment, from the viewpoint of further improving chromatic aberration and further improving field curvature of the lens unit of this embodiment, preferably, the multiple lens elements include, from the object side to the image side, first lens element 110, second lens element 120, third lens element 130, fourth lens element 140, fifth lens element 150, sixth lens element 160, and seventh lens element 170, in this order, and the Abbe number of fifth lens element 150 is 37.0 or greater and 48.0 or less, and the Abbe number of seventh lens element 170 is 37.0 or greater and 48.0 or less.

[0021] In the lens unit of this embodiment, from the viewpoint of further improving chromatic aberration, and from the viewpoint of further improving field curvature of the lens unit of this embodiment, preferably, the Abbe number of fifth lens element 150 is 37.0 or greater and 48.0 or less, and the Abbe number of seventh lens element 170 is 37.2 or greater and 48.0 or less; more preferably, the Abbe number of fifth lens element 150 is 37.0 or greater and 48.0 or less, and the Abbe number of seventh lens element 170 is 40.0 or greater and 48.0 or less; even more preferably, the Abbe number of fifth lens element 150 is 37.2 or greater and 45.0 or less, and the Abbe number of seventh lens element 170 is 42.0 or greater and 47.0 or less; and even more preferably, the Abbe number of fifth lens element 150 is 37.5 or greater and 39.0 or less, and the Abbe number of seventh lens element 170 is 44.0 or greater and 46.0 or less.

[0022] From the viewpoint of further improving chromatic aberration in the lens unit of this embodiment, and from the viewpoint of further improving field curvature in the lens unit of this embodiment, the Abbe number of fifth lens element 150 is preferably 37.0 or greater, more preferably 37.2 or greater, even more preferably 37.4 or greater, and even more preferably 37.5 or greater; and is preferably 47.0 or less, more preferably 46.0 or less, even more preferably 44.0 or less, even more preferably 42.0 or less, even more preferably 40.0 or less, and even more preferably 38.0 or less; and is preferably 37.0 or greater and 47.0 or less, more preferably 37.2 or greater and 46.0 or less, even more preferably 37.4 or greater and 44.0 or less, even more preferably 37.5 or greater and 42.0 or less, even more preferably 37.5 or greater and 40.0 or less, and even more preferably 37.5 or greater and 38.0 or less.

[0023] From the viewpoint of further improving chromatic aberration in the lens unit of this embodiment and from the viewpoint of further improving field curvature in the lens unit of this embodiment, the Abbe number of the sixth lens element 150 is preferably 15.0 or greater, more preferably 18.0 or greater, even more preferably 20.0 or greater, and is preferably 46.0 or less, more preferably 42.0 or less, even more preferably 38.0 or less, even more preferably 37.0 or less, even more preferably 32.0 or less, even more preferably 27.0 or less, and even more preferably 22.0 or less, and is preferably 15.0 or greater and 46.0 or less, more preferably 18.0 or greater and 42.0 or less, even more preferably 20.0 or greater and 38.0 or less, even more preferably 20.0 or greater and 37.0 or less, even more preferably 20.0 or greater and 32.0 or less, even more preferably 20.0 or greater and 27.0 or less, and even more preferably 20.0 or greater and 22.0 or less.

[0024] From the viewpoint of further improving chromatic aberration in the lens unit of this embodiment, and from the viewpoint of further improving field curvature in the lens unit of this embodiment, the Abbe number of seventh lens element 170 is preferably 37.0 or greater, more preferably 37.2 or greater, even more preferably 37.4 or greater, even more preferably 37.5 or greater, even more preferably 39.0 or greater, even more preferably 41.0 or greater, even more preferably 43.0 or greater, and preferably 47.0 or less, more preferably 46.0 or less, and preferably 37.0 or greater and 47.0 or less, more preferably 37.2 or greater and 46.0 or less, even more preferably 37.4 or greater and 46.0 or less, even more preferably 37.5 or greater and 46.0 or less, even more preferably 39.0 or greater and 46.0 or less, even more preferably 41.0 or greater and 46.0 or less, and even more preferably 43.0 or greater and 46.0 or less.

[0025] In the lens unit of this embodiment, from the viewpoint of further improving chromatic aberration and further improving field curvature of the lens unit of this embodiment, the Abbe number of the seventh lens element 170 is preferably larger than the Abbe number of the fifth lens element 150.

[0026] In the lens unit of this embodiment, from the viewpoint of further improving chromatic aberration and further improving field curvature of the lens unit of this embodiment, the Abbe number of the second lens element 120, the Abbe number of the third lens element 130, and the Abbe number of the sixth lens element 160 are preferably smaller than the Abbe number of the fifth lens element 150.

[0027] In the lens unit of this embodiment, from the viewpoint of further improving chromatic aberration and further improving field curvature of the lens unit of this embodiment, the Abbe number of the second lens element 120, the Abbe number of the third lens element 130, and the Abbe number of the sixth lens element 160 are preferably smaller than the Abbe number of the seventh lens element 170.

[0028] In the lens unit of this embodiment, from the viewpoint of further improving chromatic aberration and further improving field curvature of the lens unit of this embodiment, preferably, first lens element 110 has positive refractive power, second lens element 120 has positive refractive power, third lens element 130 has negative refractive power, fourth lens element 140 has positive refractive power, fifth lens element 150 has positive refractive power, sixth lens element 160 has negative refractive power, and seventh lens element 170 has positive refractive power.

[0029] The lens unit of this embodiment may include other components in addition to the lens elements, such as a diaphragm and a filter.

[0030] [Lens Element] The lens elements that constitute the lens unit of this embodiment will be described below.

[0031] The thickness of the lens elements constituting the lens unit of this embodiment is not particularly limited and can be set depending on the application, etc., and is, for example, 0.1 mm to 10 mm. In the case of a smartphone, the thickness is preferably 0.1 mm to 1 mm.

[0032] The radius of the lens elements constituting the lens unit of this embodiment is not particularly limited and can be set depending on the application, etc., and is, for example, 0.5 mm or more and 4 mm or less, and in the case of a smartphone, it is preferably 0.5 mm or more and 1 mm or less.

[0033] The refractive index at a wavelength of 589 nm of the lens elements constituting the lens unit of this embodiment, measured in accordance with ASTM D542, is preferably 1.545 or more, preferably 1.550 or more, and more preferably 1.555 or more. There is no particular upper limit to the refractive index (nd), but it is, for example, 1.580 or less. When the refractive index is within the above range, the thickness of the lens element according to this embodiment can be made thinner while maintaining good optical properties.

[0034] The haze of the lens elements constituting the lens unit of this embodiment, measured in accordance with JIS K7136:2000, is preferably less than 5% from the viewpoint of further improving transparency.

[0035] The birefringence of the lens elements constituting the lens unit of this embodiment is preferably 1 nm or more and 200 nm or less, from the viewpoint of adjusting the birefringence of the lens unit to a more appropriate range. The birefringence of the lens unit of this embodiment is the average value of the phase difference at 20 to 35 mm from the gate direction, measured at a measurement wavelength of 650 nm using a measuring instrument such as a KOBRA CCD manufactured by Oji Scientific Instruments.

[0036] In the lens unit of this embodiment, from the viewpoint of further improving chromatic aberration and further improving field curvature of the lens unit of this embodiment, preferably the plurality of lens elements include one or more aspherical lens elements, more preferably the plurality of lens elements include aspherical lens elements, and even more preferably all of the lens elements of the plurality of lens elements are aspherical lens elements.

[0037] [Lens Element Materials] Hereinafter, materials for the lens elements that constitute the lens unit of this embodiment will be described.

[0038] The material of the lens elements that constitute the lens unit of this embodiment is not particularly limited, and includes any material such as resin or glass.

[0039] From the viewpoint of ease of molding into various shapes, the lens elements constituting the lens unit of this embodiment preferably contain resin.

[0040] When the lens element contains a resin, the lens element can be obtained by molding a resin composition, which is the raw material for the lens element, into a predetermined shape. The method for molding the resin composition is not particularly limited, and known methods can be used, such as extrusion molding, injection molding, compression molding, inflation molding, blow molding, extrusion blow molding, injection blow molding, press molding, vacuum molding, powder slush molding, calendar molding, and foam molding. Among these, injection molding is preferred from the viewpoints of moldability and productivity. Furthermore, molding conditions are appropriately selected depending on the molding method, etc., and the resin temperature during injection molding is, for example, 150°C or higher and 400°C or lower, preferably 200°C or higher and 350°C or lower, and more preferably 230°C or higher and 330°C or lower.

[0041] <Materials for Lens Elements Having Abbe Numbers of 37.0 or More and 48.0 or Less> Materials for lens elements having Abbe numbers of 37.0 or more and 48.0 or less will be described below.

[0042] In the lens unit of this embodiment, from the viewpoint of further improving chromatic aberration and further improving field curvature of the lens unit of this embodiment, preferably, the lens element having an Abbe number of 37.0 or more and 48.0 or less contains a cyclic olefin polymer having a structural unit derived from a cyclic olefin as an essential structural unit.

[0043] In the lens unit of this embodiment, from the viewpoint of further improving chromatic aberration and further improving field curvature of the lens unit of this embodiment, the cyclic olefin polymer preferably includes a cyclic olefin copolymer (P) having a structural unit derived from a cyclic olefin as an essential structural unit.

[0044] (Cyclic Olefin Copolymer (P)) Hereinafter, the cyclic olefin copolymer (P) will be described.

[0045] The cyclic olefin copolymer (P) of this embodiment is a polymer having a structural unit derived from a cyclic olefin compound as an essential structural unit.

[0046] The cyclic olefin compound constituting the cyclic olefin copolymer (P) of the present embodiment is not particularly limited, and examples thereof include the cyclic olefin monomers described in paragraphs 0037 to 0063 of WO 2006 / 118261.

[0047] From the viewpoint of adjusting the Abbe number to a low level while satisfying the high refractive index required for optical lenses and the like, the cyclic olefin copolymer (P) preferably contains: a structural unit (A) derived from an α-olefin having 2 to 20 carbon atoms; a structural unit (B) derived from a cyclic olefin having no aromatic ring; and a structural unit (C) derived from a cyclic olefin having an aromatic ring.

[0048] Preferably, when the total content of the structural units (A), (B) and (C) in the cyclic olefin copolymer (P) is taken as 100 mol%, the content of the structural unit (A) in the cyclic olefin copolymer (P) is preferably 10 mol% or more and 80 mol% or less, more preferably 30 mol% or more and 75 mol% or less, and even more preferably 40 mol% or more and 70 mol% or less. When the content of the structural unit (A) is equal to or more than the lower limit, the heat resistance and dimensional stability of the lens element can be improved. Furthermore, when the content of the structural unit (A) is equal to or less than the upper limit, the transparency and the like of the lens element can be improved. In this embodiment, the content of the structural unit (A) is, for example, １ H-NMR or １３ It can be measured by C-NMR.

[0049] Preferably, when the total content of the structural units (B) and (C) in the cyclic olefin copolymer (P) is taken as 100 mol%, the content of the structural unit (C) in the cyclic olefin copolymer (P) is preferably 5 mol% to 95 mol%, more preferably 10 mol% to 90 mol%, even more preferably 20 mol% to 80 mol%, even more preferably 30 mol% to 80 mol%, and even more preferably 40 mol% to 78 mol%. When the content of the structural unit (C) is equal to or greater than the lower limit, the lens element can have a high refractive index while further reducing the Abbe number. Furthermore, when the content of the structural unit (C) is equal to or less than the upper limit, the lens element can have a better balance between the refractive index and the Abbe number. In this embodiment, the contents of the structural units (B) and (C) are, for example, １ H-NMR or １３ It can be measured by C-NMR.

[0050] The structural unit (A) according to this embodiment is a structural unit derived from an α-olefin having 2 to 20 carbon atoms. The α-olefin having 2 to 20 carbon atoms may be linear or branched, and examples thereof include linear α-olefins having 2 to 20 carbon atoms, such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene; and branched α-olefins having 4 to 20 carbon atoms, such as 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, and 3-ethyl-1-hexene. Among these, linear α-olefins having 2 to 4 carbon atoms are preferred, and ethylene is more preferred. Such linear or branched α-olefins can be used alone or in combination of two or more.

[0051] The structural unit (B) according to this embodiment is a structural unit derived from a cyclic olefin that does not have an aromatic ring.

[0052] From the viewpoint of further improving the refractive index of the lens element, the cyclic olefin having no aromatic ring preferably includes a compound represented by the following formula (B-1).

[0053]

[0054] In formula (B-1), n ​​is 0 or 1, m is 0 or a positive integer, q is 0 or 1, and R １ ~R １８ and R ａ and R ｂ are each independently a hydrogen atom, a halogen atom, or a hydrocarbon group optionally substituted with a halogen atom, and R １５ ~R １８ may be bonded to each other to form a monocyclic or polycyclic ring, and the monocyclic or polycyclic ring may have a double bond, and R １５ and R １６ With or R １７ and R １８ and may form an alkylidene group, provided that the alkylidene group does not contain an aromatic ring.

[0055] Among these, the structural unit (B) according to this embodiment includes a structural unit derived from bicyclo[2.2.1]-2-heptene, a structural unit derived from tetracyclo[4.4.0.1]-2-heptene, ２，５ .1 ７，１０ ]-3-dodecene-derived building blocks and hexacyclo[6,6,1,1 ３，６ , 1 １０，１３ , 0 ２，７ , 0 ９，１４ ]heptadecene-4-derived structural units, and the like, and bicyclo[2.2.1]-2-heptene-derived structural units and tetracyclo[4.4.0.1 ２，５ .1 ７，１０ ]-3-dodecene-derived structural units, and more preferably, tetracyclo[4.4.0.1 ２，５ .1 ７，１０ It is more preferable that the copolymer contains a structural unit derived from ]-3-dodecene.

[0056] The structural unit (C) according to this embodiment is a structural unit derived from a cyclic olefin having an aromatic ring.

[0057] From the viewpoint of further improving the performance balance of the lens element, the cyclic olefin having an aromatic ring preferably includes one or more compounds selected from the group consisting of a compound represented by the following formula (C-1), a compound represented by the following formula (C-2), and a compound represented by the following formula (C-3):

[0058]

[0059] In the above formula (C-1), n ​​and q each independently represent 0, 1, or 2. n is preferably 0 or 1, and more preferably 0. q is preferably 0 or 1, and more preferably 0. R １ ~R １７ are each independently a hydrogen atom, a halogen atom other than a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom other than a fluorine atom, and R １０ ~R １７ One of them is a bond, and R １５ is preferably a bond. １ ~R １７ are each independently preferably a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, more preferably a hydrogen atom. １０ and R １１ , R １１ and R １２ , R １２ and R １３ , R １３ and R １４ , R １４ and R １５ , R １５ and R １０ may be bonded to each other to form a monocyclic or polycyclic ring, and when q=1 or 2, R １０ and R １１ , R １１ and R １７ , R １７ and R １７ , R １７ and R １２ , R １２ and R １３ , R １３ and R １４ , R１４ and R １５ , R １５ and R １６ , R １６ and R １６ , R １６ and R １０ may be bonded to each other to form a monocycle or a polycycle, and the monocycle or the polycycle may have a double bond, or the monocycle or the polycycle may be an aromatic ring. Among the compounds represented by formula (C-1), the compounds represented by formula (C-1A) below are preferred.

[0060]

[0061]

[0062] In the above formula (C-2), n and m are each independently 0, 1, or 2, and q is 1, 2, or 3. m is preferably 0 or 1, and more preferably 1. n is preferably 0 or 1, and more preferably 0. q is preferably 1 or 2, and more preferably 1. R １８ ~R ３１ R are each independently a hydrogen atom, a halogen atom other than a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom other than a fluorine atom. １８ ~R ３１ are each independently preferably a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, more preferably a hydrogen atom. ２８ and R ２９ , R ２９ and R ３０ , R ３０ and R ３１ may be bonded to each other to form a monocyclic or polycyclic ring, and when q=2 or 3, R ２８ and R ２８ , R ２８ and R ２９ , R ２９ and R ３０ , R ３０ and R ３１ , R ３１ and R ３１may be bonded to each other to form a monocycle or polycycle, the monocycle or polycycle may have a double bond, or the monocycle or polycycle may be an aromatic ring.

[0063]

[0064] In the above formula (C-3), q is 1, 2 or 3, preferably 1 or 2, and more preferably 1. ３２ ~R ３９ R are each independently a hydrogen atom, a halogen atom other than a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom other than a fluorine atom. ３２ ~R ３９ are each independently preferably a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, more preferably a hydrogen atom. ３６ and R ３７ , R ３７ and R ３８ , R ３８ and R ３９ may be bonded to each other to form a monocyclic or polycyclic ring, and when q=2 or 3, R ３６ and R ３６ , R ３６ and R ３７ , R ３７ and R ３８ , R ３８ and R ３９ , R ３９ and R ３９ may be bonded to each other to form a monocycle or polycycle, the monocycle or polycycle may have a double bond, or the monocycle or polycycle may be an aromatic ring.

[0065] Furthermore, the hydrocarbon groups having 1 to 20 carbon atoms in the above formulae (C-1), (C-2), and (C-3) each independently include, for example, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 15 carbon atoms, and an aromatic hydrocarbon group. More specifically, examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an amyl group, a hexyl group, an octyl group, a decyl group, a dodecyl group, and an octadecyl group. Examples of the cycloalkyl group include a cyclohexyl group. Examples of the aromatic hydrocarbon group include an aryl group or an aralkyl group such as a phenyl group, a tolyl group, a naphthyl group, a benzyl group, and a phenylethyl group. These hydrocarbon groups may be substituted with a halogen atom other than a fluorine atom.

[0066] Among these, the cyclic olefin having an aromatic ring according to this embodiment is preferably one having one aromatic ring, and for example, at least one selected from benzonorbornadiene, indenenorbornene, and methylphenylnorbornene is preferred.

[0067] Furthermore, examples of the cyclic olefin having an aromatic ring according to this embodiment include a compound represented by the following formula (C-1'), a compound represented by the following formula (C-2'), a compound represented by the following formula (C-3'), etc. These cyclic olefins having an aromatic ring may be used alone or in combination of two or more.

[0068]

[0069]

[0070]

[0071] In the above formulas (C-1′), (C-2′) and (C-3′), m and n are 0, 1 or 2, and R １ ~R ３６ are each independently a hydrogen atom, a halogen atom other than a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom other than a fluorine atom, and R １０ and R １１ , R １１ and R１２ , R １２ and R １３ , R １３ and R １４ , R ２５ and R ２６ , R ２６ and R ２７ , R ２７ and R ２８ , R ３３ and R ３４ , R ３４ and R ３５ , R ３５ and R ３６ may be bonded to each other to form a single ring, and the single ring may have a double bond.

[0072] In the above formulas (C-1'), (C-2') and (C-3'), m is preferably 0 or 1, more preferably 1. n is preferably 0 or 1, more preferably 0. R １ ~R ３６ is preferably a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and more preferably a hydrogen atom.

[0073] Furthermore, the hydrocarbon groups having 1 to 20 carbon atoms in the above formulae (C-1'), (C-2'), and (C-3') each independently include, for example, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 15 carbon atoms, and an aromatic hydrocarbon group. More specifically, examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an amyl group, a hexyl group, an octyl group, a decyl group, a dodecyl group, and an octadecyl group. Examples of the cycloalkyl group include a cyclohexyl group. Examples of the aromatic hydrocarbon group include an aryl group or an aralkyl group such as a phenyl group, a tolyl group, a naphthyl group, a benzyl group, and a phenylethyl group. These hydrocarbon groups may be substituted with a halogen atom other than a fluorine atom.

[0074] Among these, the cyclic olefin having an aromatic ring according to this embodiment is preferably one having one aromatic ring.

[0075] From the viewpoint of further improving the balance of performance of the lens element, the cyclic olefin having an aromatic ring preferably includes one or more selected from the group consisting of benzonorbornadiene, indenenorbornene, and methylphenylnorbornene.

[0076] The copolymerization type of the cyclic olefin copolymer (P) according to this embodiment is not particularly limited, and examples thereof include a random copolymer, a block copolymer, etc. In this embodiment, from the viewpoint of being able to obtain a molded product having excellent optical properties such as transparency, Abbe number, refractive index, and birefringence, the cyclic olefin copolymer (P) according to this embodiment is preferably a random copolymer.

[0077] The cyclic olefin copolymer (P) according to this embodiment can be produced by appropriately selecting conditions according to the methods described in, for example, JP-A-60-168708, JP-A-61-120816, JP-A-61-115912, JP-A-61-115916, JP-A-61-271308, JP-A-61-272216, JP-A-62-252406, JP-A-62-252407, JP-A-2007-314806, and JP-A-2010-241932.

[0078] In the cyclic olefin copolymer (P) according to this embodiment, when an injection-molded sheet having a thickness of 1.0 mm is produced from the cyclic olefin copolymer (P), the refractive index (nd) of the injection-molded sheet at a wavelength of 589 nm, measured in accordance with ASTM D542, is preferably 1.545 or more, preferably 1.550 or more, more preferably 1.555 or more. The upper limit of the refractive index (nd) is not particularly limited, but is, for example, 1.580 or less. When the refractive index is within the above range, the thickness can be made thinner while maintaining good optical properties of the lens element.

[0079] In addition, in the cyclic olefin copolymer (P) according to this embodiment, from the viewpoint of further improving the transparency of the lens element, when an injection-molded sheet having a thickness of 1.0 mm is produced from the cyclic olefin copolymer (P), the haze of the injection-molded sheet measured in accordance with JIS K7136:2000 is preferably less than 5%.

[0080] Furthermore, in the cyclic olefin copolymer (P) according to this embodiment, from the viewpoint of adjusting the Abbe number of the lens element to a more suitable range, when an injection-molded sheet having a thickness of 1.0 mm is produced from the cyclic olefin copolymer (P), the Abbe number of the injection-molded sheet is preferably 37.0 or more, more preferably 37.5 or more, and preferably 48.0 or less, more preferably 47.0 or less, even more preferably 46.0 or less, and even more preferably 45.0 or less. The Abbe number of the injection-molded sheet can be obtained by the above-mentioned method for calculating the Abbe number of a lens element.

[0081] In the cyclic olefin copolymer (P) according to this embodiment, from the viewpoint of adjusting the birefringence of the lens element to a more suitable range, when an injection-molded sheet having a thickness of 1.0 mm is produced from the cyclic olefin copolymer (P), the birefringence of the injection-molded sheet is preferably 1 nm or more and 200 nm or less. The birefringence of the injection-molded sheet can be obtained by the above-mentioned method for measuring the birefringence of a lens element.

[0082] The glass transition temperature (Tg) of the cyclic olefin copolymer (P) according to this embodiment, as measured by a differential scanning calorimeter (DSC), is preferably 120°C or higher and 180°C or lower, more preferably 130°C or higher and 170°C or lower, and even more preferably 140°C or higher and 160°C or lower, from the viewpoint of further improving heat resistance while maintaining good transparency, haze, Abbe number, birefringence, refractive index, and the like of the lens element.

[0083] The intrinsic viscosity [η] (in decalin at 135°C) of the cyclic olefin copolymer (P) according to this embodiment is, for example, 0.05 to 5.0 dl / g, preferably 0.2 to 4.0 dl / g, more preferably 0.3 to 2.0 dl / g, and still more preferably 0.4 to 1.0 dl / g.

[0084] From the viewpoint of further improving the performance balance of transparency, haze, birefringence, Abbe number, and refractive index, the content of the cyclic olefin copolymer (P) in a lens element having an Abbe number of 37.0 or more and 48.0 or less is preferably 50% by mass or more and 100% by mass or less, more preferably 70% by mass or more and 100% by mass or less, even more preferably 80% by mass or more and 100% by mass or less, and particularly preferably 90% by mass or more and 100% by mass or less, when the entire lens element is taken as 100% by mass.

[0085] (Other Components) Lens elements having an Abbe number of 37.0 or more and 48.0 or less may contain known additives as optional components, as long as the good physical properties of the lens element are not impaired, as necessary. Examples of additives that can be incorporated include hydrophilic stabilizers, phenolic stabilizers, metal salts of higher fatty acids, antioxidants, ultraviolet absorbers, hindered amine light stabilizers, hydrochloric acid absorbers, metal deactivators, antistatic agents, antifogging agents, lubricants, slip agents, nucleating agents, plasticizers, flame retardants, and phosphorus-based stabilizers, and can be incorporated in appropriate amounts to the extent that the object of the present invention is not impaired.

[0086] 2. Imaging Unit The imaging unit of this embodiment will now be described.

[0087] The imaging unit of this embodiment includes the above-described lens unit and an image sensor.

[0088] The type of image sensor is not particularly limited, and known types such as CCD, CMOS, etc. can be used. Furthermore, by using an image sensor characterized by high sensitivity and low noise, it becomes possible to capture even clearer images.

[0089] The imaging unit of this embodiment may include components other than the lens unit and the image sensor, and for example, known components for imaging units, such as a holder member for holding the lens unit, may be used.

[0090] The imaging unit of this embodiment may include a drive device for driving each component. The drive device may also have an autofocus function, which makes it easier for the imaging unit to focus and enables it to capture clear images.

[0091] The imaging unit of this embodiment may include an image stabilization device such as an acceleration sensor, a gyroscope, a Hall effect sensor, etc. The image stabilization device may be configured to correct image shake in cooperation with the drive device.

[0092] The focal length of the photographing unit 20 of this embodiment is preferably 3.0 mm or more, more preferably 3.2 mm or more, even more preferably 3.4 mm or more, and preferably 4.2 mm or less, more preferably 4.0 mm or less, even more preferably 3.8 mm or less.

[0093] The F-number of the photographing unit 20 of this embodiment is, for example, 1.7 or more, and from the viewpoint of improving brightness, is preferably 2.4 or less, and more preferably 2.0 or less.

[0094] The HFOV of the imaging unit 20 of this embodiment is preferably 75 or more, more preferably 80 or more, even more preferably 90 or more, and preferably 100 or less.

[0095] 3. Electronic Device The electronic device of this embodiment will now be described.

[0096] The electronic device of this embodiment includes the imaging unit described above.

[0097] The electronic device of this embodiment may include one imaging unit or multiple imaging units.

[0098] The type of electronic device of this embodiment is not particularly limited as long as it can be equipped with an imaging unit, and examples of the electronic device of this embodiment include smartphones, laptops, digital cameras, mobile devices, digital tablets, multi-camera devices, wearable devices, smart TVs, network monitoring devices, image recognition systems, motion sensing input devices, dashboard cameras, and vehicle backup cameras.

[0099] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations may be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention.

[0100] The present invention will be specifically described below based on examples, but the present invention is not limited to these examples.

[0101] [Example 1] <Production conditions for cyclic olefin copolymer> [Production Example 1] Nitrogen as an inert gas was passed through a 500 ml glass reaction vessel equipped with a stirrer at a flow rate of 100 Nl / hr for 30 minutes, and then cyclohexane, tetracyclo[4.4.0.1], and cyclohexane were added. ２，５ .1 ７，１０]-3-dodecene (40 mmol, hereinafter also referred to as tetracyclododecene), and benzonorbornadiene (88 mmol, hereinafter also referred to as BNBD) were added. Next, the solvent temperature was raised to 50 ° C. while stirring the polymerization solvent at a rotation speed of 600 rpm. After the solvent temperature reached a predetermined temperature, the flow gas was switched from nitrogen to ethylene, and ethylene was flowed into the reaction vessel at a feed rate of 50 Nl / hr and hydrogen at a feed rate of 2.0 Nl / hr. After 10 minutes, PMAO (1.8 mmol) and a catalyst (0.0030 mmol) prepared by the method described in paragraph 0112 of JP 2010-241932 A were added to the glass reaction vessel to initiate polymerization. After 10 minutes, 5 ml of isobutyl alcohol was added to terminate the polymerization, and a polymerization solution containing a copolymer of ethylene, tetracyclododecene, and BNBD was obtained. The polymerization solution was then transferred to a separately prepared 2 L beaker, and 5 ml of concentrated hydrochloric acid and a stirrer were added. The mixture was then allowed to come into contact with the polymer solution for 2 hours under vigorous stirring to perform a decalcification operation. The decalcified polymerization solution was added to a beaker containing acetone in an amount approximately three times the volume of the polymerization solution under stirring to precipitate a copolymer, which was then separated from the filtrate by filtration. The resulting solvent-containing polymer was dried under reduced pressure at 130°C for 10 hours, yielding 4.58 g of a white powdery ethylene-tetracyclododecene-BNBD copolymer. This gave a cyclic olefin copolymer (P-1).

[0102] <Method for measuring the content of each structural unit constituting a cyclic olefin copolymer> The contents of ethylene, tetracyclododecene, and BNBD were measured using a nuclear magnetic resonance spectrometer "ECA500" manufactured by JEOL Ltd. under the following conditions: Solvent: deuterated tetrachloroethane Sample concentration: 50 to 100 g / L-solvent Pulse repetition time: 5.5 seconds Number of accumulations: 6,000 to 16,000 Measurement temperature: 120°C Measurement was performed under the above conditions. １３The compositions of ethylene, tetracyclododecene, and BNBD in the cyclic olefin copolymer (P-1) were quantified by C-NMR spectroscopy. The content of ethylene-derived structural units was 60 mol%, the content of tetracyclododecene-derived structural units was 22 mol%, and the content of BNBD-derived structural units was 18 mol%.

[0103] <Glass transition temperature Tg (°C)> Measured using a DSC-6220 manufactured by Shimadzu Science Co., Ltd. ２ The glass transition temperature (Tg) of the cyclic olefin copolymer was measured under a nitrogen atmosphere. The cyclic olefin copolymer was heated from room temperature to 200°C at a heating rate of 10°C / min, held at this temperature for 5 minutes, and then cooled to -20°C at a heating rate of 10°C / min, held at this temperature for 5 minutes. The glass transition temperature (Tg) of the cyclic olefin copolymer (P-1) was determined from the endothermic curve obtained when the temperature was raised to 200°C at a heating rate of 10°C / min. The glass transition temperature (Tg) of the cyclic olefin copolymer (P-1) was 153°C.

[0104] <Intrinsic viscosity [η]> Using a moving viscometer (manufactured by Rigo Co., Ltd., Type VNR053U), 0.25 to 0.30 g of cyclic olefin copolymer was dissolved in 25 ml of decalin to prepare a sample. The specific viscosity of the cyclic olefin copolymer (P-1) was measured at 135°C in accordance with ASTM J1601, and the ratio of this to the concentration was extrapolated to a concentration of 0 to determine the intrinsic viscosity [η] of the cyclic olefin copolymer (P-1). The intrinsic viscosity [η] of the cyclic olefin copolymer (P-1) was 0.45 dl / g.

[0105] <Molding Conditions for Lens Elements> Lens elements were molded using a mold from the cyclic olefin copolymer (P-1) obtained by the above method and a commercially available resin.

[0106] <Refractive Index> The refractive index of the lens element was measured at a wavelength of 589 nm in accordance with ASTM D 542. The refractive index of the lens element is described in the section <Configuration of Lens Unit and Imaging Unit>.

[0107] <Abbe number (ν)> The Abbe number (ν) of a lens element was calculated using the following formula from the refractive indexes of the lens element at wavelengths of 486 nm, 589 nm, and 656 nm at an ambient temperature of 23°C, which were obtained by measuring the lens element in accordance with ASTM D542. The Abbe number (ν) of a lens element is described in the section <Configuration of lens unit and imaging unit>. ν = (nD-1) / (nF-nC) nD: refractive index at wavelength of 589 nm nC: refractive index at wavelength of 656 nm nF: refractive index at wavelength of 486 nm

[0108] <Configuration of Lens Unit and Imaging Unit> The configuration of the lens unit and imaging unit of Example 1 will be described below with reference to Figures 1 to 3. Figure 1 is a cross-sectional view that schematically shows a lens unit 10 of Example 1. Figure 2 is a cross-sectional view that schematically shows an imaging unit 20 of Example 1. Figure 3 is a cross-sectional view that schematically shows the path of a light ray 200 relative to the imaging unit of Example 1.

[0109] The lens unit of Example 1 includes, in order from the object side to the image side, a diaphragm 100, a first lens element 110, a second lens element 120, a third lens element 130, a fourth lens element 140, a fifth lens element 150, a sixth lens element 160, a seventh lens element 170, a filter 180, and an image plane 190. The lens unit of Example 1 does not include any additional lens elements between the first lens element 110 and the seventh lens element 170, and includes seven single, non-fixed lens elements 110, 120, 130, 140, 150, 160, and 170.

[0110] Of the lens elements constituting the lens unit of Example 1, lens elements 110, 120, 130, and 140 belong to the front group LF, and lens elements 150, 160, and 170 belong to the rear group LR.

[0111] In first lens element 110, object-side surface 111 is convex toward the object side, and image-side surface 112 is concave toward the image side. First lens element 110 contains cyclic olefin resin (manufactured by Mitsui Chemicals, product name: APL5514ML). Both object-side surface 111 and image-side surface 112 are aspheric.

[0112] In second lens element 120, object-side surface 121 is convex toward the object side, and image-side surface 122 is concave toward the image side. Second lens element 120 contains acrylic resin (manufactured by Mitsubishi Gas Chemical Company, product name: EP8000). Both object-side surface 121 and image-side surface 122 are aspheric.

[0113] In the third lens element 130, the object-side surface 131 has a positive radius of curvature, and the image-side surface 132 has a negative radius of curvature. The third lens element 130 contains acrylic resin (manufactured by Mitsubishi Gas Chemical Company, product name: EP8000). The object-side surface 131 and the image-side surface 132 are both aspheric.

[0114] In fourth lens element 140, object-side surface 141 is convex toward the object side, and image-side surface 142 is convex toward the image side. Fourth lens element 140 contains cyclic olefin resin (manufactured by Mitsui Chemicals, product name: APL5514ML). Both object-side surface 141 and image-side surface 142 are aspheric.

[0115] In fifth lens element 150, object-side surface 151 is concave toward the object side, and image-side surface 152 is convex toward the image side. Fifth lens element 150 contains cyclic olefin-based copolymer (P-2) (ethylene-tetracyclododecene-BNBD copolymer, refractive index: 1.57, Abbe number: 37.5) polymerized in the same manner as cyclic olefin-based copolymer (P-1). Both object-side surface 151 and image-side surface 152 are aspherical.

[0116] In sixth lens element 160, object-side surface 161 is concave toward the object side, and image-side surface 162 is concave toward the image side. Sixth lens element 160 contains acrylic resin (manufactured by Mitsubishi Gas Chemical Company, product name: EP8000). Both object-side surface 161 and image-side surface 162 are aspheric.

[0117] In seventh lens element 170, object-side surface 171 has a positive radius of curvature, and image-side surface 172 is concave toward the image side. Seventh lens element 170 contains cyclic olefin copolymer (P-1) (ethylene-tetracyclododecene-BNBD copolymer, refractive index: 1.56, Abbe number: 45.0) obtained by the method described above. Both object-side surface 171 and image-side surface 172 are aspherical.

[0118] Filter 180 is made of glass and is disposed between seventh lens element 170 and image plane 190 of the lens unit of this embodiment. Filter 180 does not affect the focal length of the lens unit of this embodiment.

[0119] The imaging unit of Example 1 includes the above-described lens unit 10 and an image sensor 195. The image sensor 195 is disposed on the image plane 190 of the lens unit 10.

[0120] The optical data of the lens unit of this example are shown in Table 1. Surface numbers 0, 1, 2, 3, 4, 5, 6, and 7 in Table 1 correspond to an object (not shown), aperture stop 100, object-side surface 111, image-side surface 112, object-side surface 121, image-side surface 122, object-side surface 131, and image-side surface 132, respectively. Surface numbers 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, and 19 in Table 1 correspond to object-side surface 141, image-side surface 142, object-side surface 151, image-side surface 152, object-side surface 161, image-side surface 162, object-side surface 171, image-side surface 172, filter 180 (object-side surface), filter 180 (image-side surface), and an image (not shown), respectively.

[0121]

[0122] The aspherical surface profile of the lens unit of this embodiment is expressed by the following equation (1).

[0123]

[0124] In the above formula (1), Z is the sag amount in a direction parallel to the optical axis of the lens, c is the reciprocal of the central radius of curvature of the lens, r is the radial distance from the optical axis of the lens, k is the conic coefficient, and α ｎ is the aspherical coefficient of the nth degree term.

[0125] When the aspherical profile of the lens unit of this embodiment is expressed by the above formula (1), the conic coefficient and the aspherical coefficient α of the n-th order term are ｎ are shown in Table 2. The surface numbers in Table 2 correspond to the surface numbers in Table 1.

[0126]

[0127] In this embodiment, when the focal length of the photographing unit 20 is f, the F-number is Fno, and half of the maximum field of view is HFOV, the following conditions are satisfied: f=3.49 mm, Fno=1.9, and HFOV=40.5°.

[0128] When the Abbe numbers of the first, second, third, fourth, fifth, sixth, and seventh lens elements of this example are V1, V2, V3, V4, V5, V6, and V7, respectively, and the minimum Abbe number of the lens elements of this example is Vmin, the following conditions are satisfied. The Abbe numbers of the lens elements were calculated using the method described above: Vmin = V2 = V3 = V6 = 20.4 V5 = 37.5 V7 = 45.0 |V1 - V4| ≦ 0.1 V3 + V5 + V7 = 102.9

[0129] In this embodiment, when the axial distance between the second lens element 120 and the third lens element 130 is T23, the axial distance between the third lens element 130 and the fourth lens element 140 is T34, the axial distance between the fifth lens element 150 and the sixth lens element 160 is T56, and the maximum value of the axial distance between two adjacent lens elements is ATmax and the minimum value is ATmin, the following conditions are satisfied. Note that in the lens unit of this embodiment, the axial distance between two adjacent lens elements refers to the air-to-air distance in the coaxial region between the two adjacent lens elements. ATmax = T23 ATmin = T34 ATmax / ATmin = T23 / T34 = 10.0 T34 / T56 = 0.15

[0130] When the axial distance between the object-side surface 111 of the first lens element 110 and the image plane 190 is TL, and the axial distance between the sixth lens element 160 and the seventh lens element 170 is T67, the following condition is satisfied: TL / T67=5.88

[0131] When the entrance pupil diameter of the lens unit of this embodiment is EPD, the following condition is satisfied: TL / EPD=2.818

[0132] When the focal length of the sixth lens element 160 is f6, the following condition is satisfied: |TL / f6|=0.57

[0133] When the radius of curvature of object-side surface 121 of second lens element 120 is R3 and the radius of curvature of image-side surface 122 of second lens element 120 is R4, the following condition is satisfied: (R3+R4) / (R3-R4)=-21.04

[0134] When the radius of curvature of the image-side surface 142 of the fourth lens element 140 is R8 and the radius of curvature of the object-side surface 151 of the fifth lens element 150 is R9, the following condition is satisfied: (R8+R9) / (R8-R9)=3.10

[0135] When the radius of curvature of the object-side surface 171 of the seventh lens element 170 is R13 and the radius of curvature of the image-side surface 172 of the seventh lens element 170 is R14, the following condition is satisfied: (R13+R14) / (R13-R14)=1.81

[0136] When the focal length of the lens unit of this embodiment is f, the radius of curvature of the object-side surface 161 of the sixth lens element 160 is R11, and the radius of curvature of the image-side surface 162 of the sixth lens element 160 is R12, the following condition is satisfied: |f / R11|+|f / R12|=0.61

[0137] The following condition is met: f / EPD≦2.0

[0138] When the focal length of the first lens element 110 is f1, the following condition is satisfied: f / f1=0.47

[0139] When the focal length of seventh lens element 170 is f7, the following condition is satisfied: |f7 / f1|=0.50

[0140] When the focal length of the second lens element 120 is f2, the following condition is satisfied: |f2 / f6|=3.72

[0141] When the maximum image height of the lens unit of this embodiment is ImgH, the following condition is satisfied: (TL)×2 / (EPD×ImgH)=4.33

[0142] When the axial distance between the image-side surface 172 of the seventh lens element 170 and the image plane 190 is BL, the following condition is satisfied: BL / EPD=0.28

[0143] The following condition is met: TL / ImgH=1.39

[0144] When the axial distance between the aperture stop 100 and the object-side surface 131 of the third lens element 130 is Dsr5 and the axial distance between the aperture stop 100 and the image-side surface 132 of the third lens element 130 is Dsr6, the following condition is satisfied: |Dsr5 / Dsr6|=0.81

[0145] The refractive index of fifth lens element 150 measured by the above method was 1.574.

[0146] The refractive index of seventh lens element 170 measured by the above method was 1.56.

[0147] Example 2 A lens unit was fabricated under the same conditions as in Example 1, except that the cyclic olefin copolymer (P-1) of the seventh lens element was changed to a cyclic olefin resin (P-2).

[0148] The optical data of the lens unit of Example 2 is shown in Table 3. The correspondence between the surface numbers and surfaces in Table 3 is the same as in Example 1.

[0149]

[0150] The aspherical surface profile of the lens unit of Example 2, and the conic coefficient and the n-th order aspherical surface coefficient α when the aspherical surface profile of the lens unit of Example 2 is expressed by the above formula (1) ｎ is the same as in the first embodiment.

[0151] When the focal length of the photographing unit 20 in the second embodiment is f, the F-number is Fno, and half of the maximum field of view is HFOV, the following conditions are satisfied: f=3.42 mm, Fno=1.9, and HFOV=40.5°.

[0152] When the Abbe numbers of the first, second, third, fourth, fifth, sixth, and seventh lens elements of Example 2 are V1, V2, V3, V4, V5, V6, and V7, respectively, and the minimum Abbe number of the lens elements of this example is Vmin, the following conditions are satisfied. The Abbe numbers of the lens elements were calculated using the method described above. Vmin = V2 = V3 = V6 = 20.4 V5 = V7 = 37.5 |V1 - V4| ≦ 0.1 V3 + V5 + V7 = 95.4

[0153] In Example 2, when the axial distance between the second lens element 120 and the third lens element 130 is T23, the axial distance between the third lens element 130 and the fourth lens element 140 is T34, the axial distance between the fourth lens element 130 and the fifth lens element 140 is T45, and the axial distance between the fifth lens element 150 and the sixth lens element 160 is T56, and the maximum value of the axial distance between two adjacent lens elements is ATmax and the minimum value is ATmin, the following conditions are satisfied. Note that in the lens unit of this example, the axial distance between two adjacent lens elements refers to the air-to-air distance in the coaxial region between the two adjacent lens elements. ATmax = T45 ATmin = T56 ATmax / ATmin = T45 / T56 = 1.81 T34 / T56 = 0.18

[0154] When the axial distance between the object-side surface 111 of the first lens element 110 and the image plane 190 in Example 2 is TL, and the axial distance between the sixth lens element 160 and the seventh lens element 170 is T67, the following condition is satisfied: TL / T67=5.57

[0155] When the entrance pupil diameter of the lens unit of Example 2 is EPD, the following condition is satisfied: TL / EPD=2.879

[0156] When the focal length of the sixth lens element 160 in Example 2 is f6, the following condition is satisfied: |TL / f6|=0.47

[0157] When the radius of curvature of the object-side surface 121 of the second lens element 120 in Example 2 is R3 and the radius of curvature of the image-side surface 122 of the second lens element 120 is R4, the following condition is satisfied: (R3+R4) / (R3-R4)=-21.18

[0158] When the radius of curvature of the image-side surface 142 of the fourth lens element 140 in Example 2 is R8 and the radius of curvature of the object-side surface 151 of the fifth lens element 150 is R9, the following condition is satisfied: (R8+R9) / (R8-R9)=1.85

[0159] When the radius of curvature of the object-side surface 171 of the seventh lens element 170 in Example 2 is R13 and the radius of curvature of the image-side surface 172 of the seventh lens element 170 is R14, the following condition is satisfied: (R13+R14) / (R13-R14)=1.83

[0160] When the focal length of the lens unit of Example 2 is f, the radius of curvature of the object-side surface 161 of the sixth lens element 160 is R11, and the radius of curvature of the image-side surface 162 of the sixth lens element 160 is R12, the following condition is satisfied: |f / R11|+|f / R12|=0.56

[0161] The following condition is met: f / EPD≦2.0

[0162] When the focal length of the first lens element 110 in Example 2 is f1, the following condition is satisfied: f / f1=0.45

[0163] When the focal length of the seventh lens element 170 in Example 2 is f7, the following condition is satisfied: |f7 / f1|=0.47

[0164] When the focal length of the second lens element 120 in Example 2 is f2, the following condition is satisfied: |f2 / f6|=3.04

[0165] When the maximum image height of the lens unit of Example 2 is ImgH, the following condition is satisfied: (TL)×2 / (EPD×ImgH)=1.29

[0166] When the axial distance between the image-side surface 172 of the seventh lens element 170 and the image plane 190 in Example 2 is BL, the following condition is satisfied: BL / EPD=0.29

[0167] The following condition is met: TL / ImgH=1.10

[0168] When the axial distance between the aperture stop 100 and the object-side surface 131 of the third lens element 130 in Example 2 is Dsr5, and the axial distance between the aperture stop 100 and the image-side surface 132 of the third lens element 130 is Dsr6, the following condition is satisfied: |Dsr5 / Dsr6|=0.88

[0169] The refractive index of the fifth lens element 150 of Example 2 measured by the above method was 1.574.

[0170] The refractive index of the seventh lens element 170 of Example 2 measured by the above method was 1.574.

[0171] Example 3 A lens unit was produced under the same conditions as in Example 1, except that the acrylic resin (manufactured by Mitsubishi Gas Chemical Company, product name: EP8000) of the sixth lens element was changed to a cyclic olefin-based resin (P-2), and the cyclic olefin-based copolymer (P-1) of the seventh lens element was changed to a cyclic olefin-based resin (P-2).

[0172] The optical data of the lens unit of Example 3 is shown in Table 4. The correspondence between the surface numbers and surfaces in Table 4 is the same as in Example 1.

[0173]

[0174] The aspherical surface profile of the lens unit of Example 3, and the conic coefficient and the n-th order aspherical surface coefficient α when the aspherical surface profile of the lens unit of Example 3 is expressed by the above formula (1) ｎ is the same as in the first embodiment.

[0175] When the focal length of the photographing unit 20 in Example 3 is f, the F-number is Fno, and half of the maximum field of view is HFOV, the following conditions are satisfied: f=3.36 mm, Fno=1.9, and HFOV=40.5°.

[0176] When the Abbe numbers of the first, second, third, fourth, fifth, sixth, and seventh lens elements of Example 3 are V1, V2, V3, V4, V5, V6, and V7, respectively, and the minimum Abbe number of the lens elements of this example is Vmin, the following conditions are satisfied. The Abbe numbers of the lens elements were calculated using the method described above: Vmin = V2 = V3 = 20.4 V5 = V6 = V7 = 37.5 |V1 - V4| ≦ 0.1 V3 + V5 + V7 = 95.4

[0177] In Example 3, when the axial distance between the second lens element 120 and the third lens element 130 is T23, the axial distance between the third lens element 130 and the fourth lens element 140 is T34, the axial distance between the fourth lens element 130 and the fifth lens element 140 is T45, and the axial distance between the fifth lens element 150 and the sixth lens element 160 is T56, and the maximum value of the axial distance between two adjacent lens elements is ATmax and the minimum value is ATmin, the following conditions are satisfied. Note that in the lens unit of this example, the axial distance between two adjacent lens elements refers to the air-to-air distance in the coaxial region between the two adjacent lens elements. ATmax = T45 ATmin = T56 ATmax / ATmin = T45 / T56 = 2.37 T34 / T56 = 0.26

[0178] When the axial distance between the object-side surface 111 of the first lens element 110 and the image plane 190 in Example 3 is TL, and the axial distance between the sixth lens element 160 and the seventh lens element 170 is T67, the following condition is satisfied: TL / T67=5.48

[0179] When the entrance pupil diameter of the lens unit of Example 3 is EPD, the following condition is satisfied: TL / EPD=2.738

[0180] When the focal length of the sixth lens element 160 in Example 3 is f6, the following condition is satisfied: |TL / f6|=0.45

[0181] When the radius of curvature of the object-side surface 121 of the second lens element 120 in Example 3 is R3 and the radius of curvature of the image-side surface 122 of the second lens element 120 is R4, the following condition is satisfied: (R3+R4) / (R3-R4)=-21.18

[0182] When the radius of curvature of the image-side surface 142 of the fourth lens element 140 in Example 3 is R8 and the radius of curvature of the object-side surface 151 of the fifth lens element 150 is R9, the following condition is satisfied: (R8+R9) / (R8-R9)=1.85

[0183] When the radius of curvature of the object-side surface 171 of the seventh lens element 170 in Example 3 is R13 and the radius of curvature of the image-side surface 172 of the seventh lens element 170 is R14, the following condition is satisfied: (R13+R14) / (R13-R14)=1.62

[0184] When the focal length of the lens unit of Example 3 is f, the radius of curvature of the object-side surface 161 of the sixth lens element 160 is R11, and the radius of curvature of the image-side surface 162 of the sixth lens element 160 is R12, the following condition is satisfied: |f / R11|+|f / R12|=0.55

[0185] The following condition is met: f / EPD≦1.9

[0186] When the focal length of the first lens element 110 in Example 3 is f1, the following condition is satisfied: f / f1=0.46

[0187] When the focal length of the seventh lens element 170 in Example 3 is f7, the following condition is satisfied: |f7 / f1|=0.42

[0188] When the focal length of the second lens element 120 in Example 3 is f2, the following condition is satisfied: |f2 / f6|=2.98

[0189] When the maximum image height of the lens unit of Example 3 is ImgH, the following condition is satisfied: (TL)×2 / (EPD×ImgH)=1.22

[0190] When the axial distance between the image-side surface 172 of the seventh lens element 170 and the image plane 190 in Example 3 is BL, the following condition is satisfied: BL / EPD=0.28

[0191] The following condition is met: TL / ImgH=1.08

[0192] When the axial distance between the aperture stop 100 and the object-side surface 131 of the third lens element 130 in Example 3 is Dsr5, and the axial distance between the aperture stop 100 and the image-side surface 132 of the third lens element 130 is Dsr6, the following condition is satisfied: |Dsr5 / Dsr6|=0.88

[0193] The refractive index of fifth lens element 150 measured by the above method was 1.574.

[0194] The refractive index of seventh lens element 170 measured by the above method was 1.574.

[0195] Comparative Example 1 A lens unit was produced under the same conditions as in Example 1, except that the cyclic olefin copolymer (P-1) of the fifth lens element was changed to a cyclic olefin resin (manufactured by Mitsui Chemicals, product name: APL5514MLML, Abbe number: 55.9), and the cyclic olefin copolymer (P-1) of the seventh lens element was changed to a cyclic olefin resin (manufactured by Mitsui Chemicals, product name: APL5514ML, Abbe number: 55.9).

[0196] 4 to 7 show chromatic aberration curves for the lens units of Examples 1 to 3 and Comparative Example 1, respectively. The numbers attached to the chromatic aberration curves indicate the wavelength of light (unit: μm). Furthermore, "airy" refers to the diameter of the circle formed when light is converged to a single point by the lens unit and then blurred into concentric circles. The chromatic aberration curve indicates the ratio of change due to wavelength between the central and peripheral portions of the image; the smaller the absolute value of the maximum or minimum value of the chromatic aberration curve, the better the chromatic aberration is corrected, and the higher the definition of the lens unit.

[0197] The chromatic aberration curve of Example 1 ( FIG. 4 ) had a maximum value of 0.7 μm and a minimum value of 0.1 μm; the chromatic aberration curve of Example 2 ( FIG. 5 ) had a maximum value of 0.5 μm and a minimum value of −0.9 μm; the chromatic aberration curve of Example 3 ( FIG. 6 ) had a maximum value of 1.6 μm and a minimum value of 1.2 μm; and the chromatic aberration curve of Comparative Example 1 ( FIG. 7 ) had a maximum value of 0.9 μm and a minimum value of 0.3 μm. Comparing Example 1 and Example 2, the absolute values ​​of the maximum values ​​were equivalent, but the absolute value of the minimum value was smaller in Example 1. This shows that the lens unit of Example 1 can further improve chromatic aberration than the lens unit of Example 2. Furthermore, comparing Example 1 and Example 3, the absolute values ​​of both the maximum value and the minimum value were smaller in Example 1. This shows that the lens unit of Example 1 can further improve chromatic aberration than the lens unit of Example 3.

[0198] 8 to 11 show the field curvature curves of the lens units of Examples 1 to 3 and Comparative Example 1, respectively. The numerical values ​​attached to the field curvature curves indicate the wavelength of light (unit: μm). The letters attached to the field curvature curves indicate the surface onto which the light is incident. The curves marked with "T" are the field curvature curves due to light rays incident on a surface (tangential surface) including the optical axis of the lens, and the curves marked with "S" are the field curvature curves due to light rays incident on a sagittal surface perpendicular to the tangential surface. The field curvature curve indicates the deviation of the focal position relative to the imaging surface, and the difference between the minimum and maximum values ​​of the field curvature curve (hereinafter referred to as the maximum width) is an index of the focal position. Specifically, the smaller the maximum width of a lens unit, the more improved the field curvature, the smaller the deviation of the focal position, and the higher the resolution of the lens unit.

[0199] The field curvature curve of Example 1 ( FIG. 8 ) had a maximum width of 0.12 μm, the field curvature curve of Example 2 ( FIG. 9 ) had a maximum width of 0.13 μm, and the field curvature curve of Example 3 ( FIG. 10 ) had a maximum width of 0.13 μm, meaning that Examples 1 to 3 had approximately the same maximum width. On the other hand, the field curvature curve of Comparative Example 1 ( FIG. 11 ) had a maximum width of 0.17 μm. That is, Examples 1 to 3 had smaller maximum widths than Comparative Example 1. From this, it can be said that the lens unit of this embodiment has improved field curvature, has smaller focal position deviation, and is a higher-definition lens unit.

[0200] This application claims priority based on Japanese Patent Application No. 2024-018663, filed February 9, 2024, the disclosure of which is incorporated herein in its entirety by reference.

[0201] 10 Lens unit 20 Imaging unit 100 Aperture 110 First lens element 111 Object side surface 112 Image side surface 120 Second lens element 121 Object side surface 122 Image side surface 130 Third lens element 131 Object side surface 132 Image side surface 140 Fourth lens element 141 Object side surface 142 Image side surface 150 Fifth lens element 151 Object side surface 152 Image side surface 160 Sixth lens element 161 Object side surface 162 Image side surface 170 Seventh lens element 171 Object side surface 172 Image side surface 180 Filter 190 Image surface 195 Image sensor 200 Light ray

Claims

1. A lens unit comprising a plurality of lens elements arranged in order from the object side to the image side, wherein the Abbe number of the lens element closest to the image side among the plurality of lens elements is 37.0 or more and 48.0 or less.

2. The lens unit according to claim 1, wherein the lens unit comprises: a front group LF on the object side, the front group LF including a plurality of lens elements that are close to or cemented together; and a rear group LR between the front group LF and the image, the rear group LR including a plurality of lens elements, the rear group LR including every other lens element having an Abbe number of 37.0 or more and 48.0 or less.

3. The lens unit according to claim 1 or 2, wherein the lens unit comprises: a front group LF on the object side, the front group LF including a plurality of lens elements that are close to or cemented together; and a rear group LR between the front group LF and the image, the rear group LR including a plurality of lens elements, the rear group LR including every other lens element having an Abbe number of 37.0 or more and 48.0 or less, and the rear group LR including every other lens element having an Abbe number of 40.0 or more and 48.0 or less.

4. The lens unit according to any one of claims 1 to 3, wherein the plurality of lens elements comprise, in this order from the object side to the image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element, and a seventh lens element, the Abbe number of the fifth lens element being 37.0 or greater and 48.0 or less, and the Abbe number of the seventh lens element being 37.0 or greater and 48.0 or less.

5. The lens unit according to claim 4, wherein the Abbe number of the fifth lens element is equal to or greater than 37.0 and equal to or less than 48.0, and the Abbe number of the seventh lens element is equal to or greater than 40.0 and equal to or less than 48.

0.

6. The lens unit according to claim 4 or 5, wherein the Abbe number of the seventh lens element is greater than the Abbe number of the fifth lens element.

7. The lens unit according to any one of claims 4 to 6, wherein the Abbe number of the second lens element, the Abbe number of the third lens element, and the Abbe number of the sixth lens element are smaller than the Abbe number of the fifth lens element.

8. The lens unit according to any one of claims 4 to 7, wherein the Abbe number of the second lens element, the Abbe number of the third lens element, and the Abbe number of the sixth lens element are smaller than the Abbe number of the seventh lens element.

9. A lens unit according to any one of claims 4 to 8, wherein the first lens element has positive refractive power, the second lens element has positive refractive power, the third lens element has negative refractive power, the fourth lens element has positive refractive power, the fifth lens element has positive refractive power, the sixth lens element has negative refractive power, and the seventh lens element has positive refractive power.

10. A lens unit according to any one of claims 1 to 9, wherein the plurality of lens elements includes one or more aspherical lens elements.

11. A lens unit according to any one of claims 1 to 10, wherein the lens element having an Abbe number of 37.0 or more and 48.0 or less contains a cyclic olefin polymer having a structural unit derived from a cyclic olefin as an essential structural unit.

12. The lens unit according to claim 11, wherein the cyclic olefin polymer comprises a cyclic olefin copolymer (P) having a structural unit derived from a cyclic olefin as an essential structural unit.

13. The lens unit according to claim 12, wherein the cyclic olefin copolymer (P) comprises a structural unit (A) derived from an α-olefin having 2 to 20 carbon atoms, a structural unit (B) derived from a cyclic olefin having no aromatic ring, and a structural unit (C) derived from a cyclic olefin having an aromatic ring.

14. The lens unit according to claim 13, wherein the content of the structural unit (A) in the cyclic olefin copolymer (P) is 10 mol % or more and 80 mol % or less, when the total content of the structural unit (A), the structural unit (B), and the structural unit (C) in the cyclic olefin copolymer (P) is taken as 100 mol %.

15. The lens unit according to claim 13 or 14, wherein the content of the structural unit (C) in the cyclic olefin copolymer (P) is 5 mol % or more and 95 mol % or less, when the total content of the structural unit (B) and the structural unit (C) in the cyclic olefin copolymer (P) is taken as 100 mol %.

16. The lens unit according to any one of claims 13 to 15, wherein the cyclic olefin having no aromatic ring includes a compound represented by the following formula (B-1): (In the formula (B-1), n is 0 or 1, m is 0 or a positive integer, q is 0 or 1, and R １ ~R １８ and R ａ and R ｂ are each independently a hydrogen atom, a halogen atom, or a hydrocarbon group optionally substituted with a halogen atom, and R １５ ~R １８ may be bonded to each other to form a monocyclic or polycyclic ring, and the monocyclic or polycyclic ring may have a double bond, and R １５ and R １６ With or R １７ and R １８ and may form an alkylidene group, provided that the aromatic ring is not included.) 17. The lens unit according to any one of claims 13 to 16, wherein the cyclic olefin having an aromatic ring comprises one or more compounds selected from the group consisting of compounds represented by the following formula (C-1), compounds represented by the following formula (C-2), and compounds represented by the following formula (C-3): (In the above formula (C-1), n and q each independently represent 0, 1, or 2; R １ ~R １７ are each independently a hydrogen atom, a halogen atom other than a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom other than a fluorine atom, and R １０ ~R １７ One of them is a bond, and when q=0, R １０ and R １１ , R １１ and R １２ , R １２ and R １３ , R １３ and R １４ , R １４ and R １５ , R １５ and R １０ may be bonded to each other to form a monocyclic or polycyclic ring, and when q=1 or 2, R １０ and R １１ , R １１ and R １７ , R １７ and R １７ , R １７ and R １２ , R １２ and R １３ , R １３ and R １４ , R １４ and R １５ , R １５ and R １６ , R １６ and R １６ , R １６ and R １０ may be bonded to each other to form a monocycle or a polycycle, and the monocycle or the polycycle may have a double bond, or the monocycle or the polycycle may be an aromatic ring. (In the above formula (C-2), n and m are each independently 0, 1, or 2, q is 1, 2, or 3, and R １８ ~R ３１ are each independently a hydrogen atom, a halogen atom other than a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom other than a fluorine atom, and when q=1, R ２８ and R ２９ , R ２９ and R ３０ , R ３０ and R ３１ may be bonded to each other to form a monocyclic or polycyclic ring, and when q=2 or 3, R ２８ and R ２８ , R ２８ and R ２９ , R ２９ and R ３０ , R ３０ and R ３１ , R ３１ and R ３１ may be bonded to each other to form a monocycle or a polycycle, the monocycle or the polycycle may have a double bond, or the monocycle or the polycycle may be an aromatic ring. (In the above formula (C-3), q is 1, 2 or 3, and R ３２ ~R ３９ are each independently a hydrogen atom, a halogen atom other than a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom other than a fluorine atom, and when q=1, R ３６ and R ３７ , R ３７ and R ３８ , R ３８ and R ３９ may be bonded to each other to form a monocyclic or polycyclic ring, and when q=2 or 3, R ３６ and R ３６ , R ３６ and R ３７ , R ３７ and R ３８ , R ３８ and R ３９ , R ３９ and R ３９ may be bonded to each other to form a monocycle or a polycycle, the monocycle or the polycycle may have a double bond, or the monocycle or the polycycle may be an aromatic ring.

18. The lens unit according to any one of claims 13 to 17, wherein the cyclic olefin having an aromatic ring includes one or more members selected from the group consisting of benzonorbornadiene, indenenorbornene, and methylphenylnorbornene.

19. An imaging unit comprising the lens unit according to any one of claims 1 to 18 and an image sensor.

20. An electronic device comprising the imaging unit of claim 19.

Images