Optical system

Abstract

The optical system includes at least one lens component, and in the optical system, the distance on the optical axis from the lens surface closest to the object side of the optical system to the lens surface closest to the image side of the optical system is set as TD, among the lens components included in the optical system, at least a portion of the lens component is located within a range of 0.3 * TD from the lens surface closest to the object side of the optical system on the optical axis to the image side. A film having a light reflectance of less than 30% is provided at 50% or more of the total area of the edge surfaces of all the front-side lens components.

Description

Technical Field

[0001] The technology of the present invention relates to an optical system. Background Art

[0002] An optical element is described in Japanese Patent Laid-Open No. 2015-028552, which has an antireflection structure composed of fine concavo-convex structures with a size equal to or smaller than the wavelength of light on at least a part of the effective light portion. A plastic lens is described in Japanese Patent Laid-Open No. 2015-148829, which is held by a holding portion, and has a first outer peripheral surface formed substantially parallel to the lens optical axis, includes a first edge portion held by the holding portion and a second edge portion having a second outer peripheral surface formed with a step difference with respect to the first outer peripheral surface, and a black coating for suppressing internal surface reflection of light is not applied on the first outer peripheral surface and is applied on at least a part of the second outer peripheral surface. Summary of the Invention

[0003] When observing an optical system such as an imaging lens from the object side and / or the image side, there is a case where the outer peripheral surface of the lens of the optical system, particularly the outer peripheral surface parallel to the optical axis, can be visually recognized by external light, which may sometimes deteriorate the appearance quality.

[0004] An object of the present invention is to provide an optical system having a high-quality appearance. Moreover, an object thereof is to maintain good performance.

[0005] Means for Solving the Technical Problem

[0006] A first aspect of the present invention is an optical system, wherein when one lens component is a single lens or a cemented lens, it includes at least one lens component. In the optical system, the outer peripheral surface parallel to the optical axis of the lens component is defined as an edge surface, the distance on the optical axis from the lens surface closest to the object side of the optical system to the lens surface closest to the image side of the optical system is defined as TD, and when the lens component in which at least a part of the lens component is located within the range from the lens surface closest to the object side of the optical system to 0.3×TD on the image side along the optical axis is defined as a front-side lens component, a film having a light reflectance of less than 30% is provided at 50% or more of the total area of the edge surfaces of all the front-side lens components.

[0007] When the open F number of the optical system in a state of focusing on an infinitely distant object is set as FNo and the maximum half angle of view of the optical system in a state of focusing on an infinitely distant object is set as ω, when FNo and ω are the values at the wide-angle end in the case where the optical system is a zoom optical system, the optical system of the first aspect preferably satisfies

[0008] 1 < FNo / tanω < 10 (1)

[0009] The conditional expression (1) represented

[0010] In the optical system of the first mode, the intersection of the lens surface closest to the object side of the optical system with the optical axis is defined as the front-side intersection point. For each front-side lens component, the angle formed by the line connecting the front-side intersection point and the point on the edge surface closest to the object side with the optical axis is defined as αf, and the angle formed by the line connecting the front-side intersection point and the point on the edge surface closest to the image side with the optical axis is defined as βf. When the units of αf and βf are degrees, it is preferable that at least 50% of the total area of the edge surfaces of all front-side lens components that satisfy

[0011] 2.7° < αf - βf < 40° (2)

[0012] a film is provided

[0013] In the optical system of the first mode, the intersection of the lens surface closest to the object side of the optical system with the optical axis is defined as the front-side intersection point. Let N be a natural number of 2 or more. For the Nth front-side lens component from the object side, the angle formed by the line connecting the front-side intersection point and the point on the edge surface closest to the object side with the optical axis is defined as αf, and the angle formed by the line connecting the front-side intersection point and the point on the edge surface closest to the image side with the optical axis is defined as βf. When the units of αf and βf are degrees and the combined focal length from the front-side lens component closest to the object side to the (N - 1)th front-side lens component from the object side is defined as ff, it is preferable that in the total area of the edge surfaces of all front-side lens components that satisfy

[0014] 1.1° < αf - βf ≤ 2.7° (3) and

[0015] -2.4 < TD / ff (4)

[0016] the proportion of the area where the film is provided is 30% or less

[0017] In the optical system of the first mode, the intersection of the lens surface closest to the object side of the optical system with the optical axis is defined as the front-side intersection point. Let N be a natural number of 2 or more. For the Nth front-side lens component from the object side, the angle formed by the line connecting the front-side intersection point and the point on the edge surface closest to the object side with the optical axis is defined as αf, and the angle formed by the line connecting the front-side intersection point and the point on the edge surface closest to the image side with the optical axis is defined as βf. When the units of αf and βf are degrees and the paraxial curvature radius of the surface closest to the image side of the Nth front-side lens component from the object side is defined as Rf, it is preferable that in the total area of the edge surfaces of all front-side lens components that satisfy

[0018] 1.1° < αf - βf ≤ 2.7° (3) and

[0019] TD / Rf < 2.4 (5)

[0020] The ratio of the area where the film is provided to the total area of the marginal surfaces of all the front-side lens components in the conditional expressions (3) and (5) shown is 30% or less.

[0021] In the optical system of the first mode, the intersection of the lens surface closest to the object side of the optical system with the optical axis is defined as the front-side intersection point. For each front-side lens component, the angle formed by the line connecting the front-side intersection point and the point on the marginal surface closest to the object side with the optical axis is defined as αf, the angle formed by the line connecting the front-side intersection point and the point on the marginal surface closest to the image side with the optical axis is defined as βf, the unit of αf and βf is degrees. Among the lens components included in the optical system, the lens components where at least a part of the lens component is located within the range from the lens surface closest to the image side of the optical system to the object side by 0.3 × TD on the optical axis are defined as the rear-side lens components. The intersection of the lens surface closest to the image side of the optical system with the optical axis is defined as the rear-side intersection point. For each rear-side lens component, the angle formed by the line connecting the rear-side intersection point and the point on the marginal surface closest to the image side with the optical axis is defined as αr, the angle formed by the line connecting the rear-side intersection point and the point on the marginal surface closest to the object side with the optical axis is defined as βr, and when the unit of αr and βr is degrees, it is preferably satisfied that

[0022] 0° < αf - βf ≤ 1.1° (10)

[0023] The ratio of the area where the film is provided to the total area of the marginal surfaces of all the front-side lens components satisfying the conditional expression (10) shown and

[0024] 0° < αr - βr ≤ 1.1° (11)

[0025] The ratio of the area where the film is provided to the total area of the marginal surfaces of all the rear-side lens components satisfying the conditional expression (11) shown is 30% or less.

[0026] The second mode of the present invention is an optical system which includes at least one lens component when one lens component is a single lens or a cemented lens. In the optical system, the outer peripheral surface parallel to the optical axis of the lens component is defined as the marginal surface, the distance on the optical axis from the lens surface closest to the object side of the optical system to the lens surface closest to the image side of the optical system is defined as TD. Among the lens components included in the optical system, when the lens components where at least a part of the lens component is located within the range from the lens surface closest to the image side of the optical system to the object side by 0.3 × TD on the optical axis are defined as the rear-side lens components, a film with a light reflectivity of less than 30% is provided at 50% or more of the total area of the marginal surfaces of all the rear-side lens components.

[0027] In the optical system of the second mode, the intersection of the lens surface closest to the image side of the optical system with the optical axis is defined as the rear intersection point. For each rear lens component, the angle formed by the line connecting the rear intersection point and the point closest to the image side of the edge surface with the optical axis is defined as αr, and the angle formed by the line connecting the rear intersection point and the point closest to the object side of the edge surface with the optical axis is defined as βr. When the units of αr and βr are degrees, it is preferably satisfied that

[0028] 2.7° < αr - βr < 40° (6)

[0029] A film is provided at 50% or more of the total area of the edge surfaces of all the rear lens components that satisfy the conditional expression (6).

[0030] In the optical system of the second mode, the intersection of the lens surface closest to the image side of the optical system with the optical axis is defined as the rear intersection point. Let M be a natural number of 2 or more. For the M-th rear lens component from the image side, the angle formed by the line connecting the rear intersection point and the point closest to the image side of the edge surface with the optical axis is defined as αr, and the angle formed by the line connecting the rear intersection point and the point closest to the object side of the edge surface with the optical axis is defined as βr. When the units of αr and βr are degrees and the combined focal length from the rear lens component closest to the image side to the (M - 1)-th rear lens component from the image side is defined as fr, it is preferably satisfied that

[0031] 1.1° < αr - βr ≤ 2.7° (7) and

[0032] -2.4 < TD / fr (8)

[0033] The proportion of the area where the film is provided in the total area of the edge surfaces of all the rear lens components that satisfy the conditional expressions (7) and (8) is 30% or less.

[0034] In the optical system of the second mode, the intersection of the lens surface closest to the image side of the optical system with the optical axis is defined as the rear intersection point. Let M be a natural number of 2 or more. For the M-th rear lens component from the image side, the angle formed by the line connecting the rear intersection point and the point closest to the image side of the edge surface with the optical axis is defined as αr, and the angle formed by the line connecting the rear intersection point and the point closest to the object side of the edge surface with the optical axis is defined as βr. When the units of αr and βr are degrees and the paraxial curvature radius of the surface closest to the object side of the M-th rear lens component from the image side is defined as Rr, it is preferably satisfied that

[0035] 1.1° < αr - βr ≤ 2.7° (7) and

[0036] -10 < TD / Rr (9)

[0037] The ratio of the area where the film is provided to the total area of the marginal surfaces of all the rear lens components of the conditional expressions (7) and (9) shown is 30% or less.

[0038] In the optical system of the second mode, among the lens components included in the optical system, the lens components in which at least a part of the lens component is located in the range from the object-side most lens surface of the optical system to 0.3×TD on the image side along the optical axis are defined as the front lens components, the intersection of the object-side most lens surface of the optical system and the optical axis is defined as the front intersection point. For each front lens component, the angle formed by the line connecting the front intersection point and the object-side most point of the marginal surface with the optical axis is defined as αf, the angle formed by the line connecting the front intersection point and the image-side most point of the marginal surface with the optical axis is defined as βf, the unit of αf and βf is degree, the intersection of the image-side most lens surface of the optical system and the optical axis is defined as the rear intersection point. For each rear lens component, the angle formed by the line connecting the rear intersection point and the image-side most point of the marginal surface with the optical axis is defined as αr, the angle formed by the line connecting the rear intersection point and the object-side most point of the marginal surface with the optical axis is defined as βr, when the unit of αr and βr is degree, it is preferable that

[0039] 0°<αf - βf ≤ 1.1° (10)

[0040] For all the marginal surfaces of the front lens components that satisfy the conditional expression (10) shown and

[0041] 0°<αr - βr ≤ 1.1° (11)

[0042] The ratio of the area where the film is provided to the total area of all the marginal surfaces of the rear lens components that satisfy the conditional expression (11) shown is 30% or less.

[0043] The optical system of the above mode can be configured to sequentially include a first lens group with positive refractive power and a subsequent group including at least one lens group from the object side to the image side. During zooming, the interval between adjacent lens groups changes. The subsequent group can be configured to include a second lens group with negative refractive power on the object-side most. The subsequent group can be configured to sequentially and continuously include a second lens group, a third lens group, and a fourth lens group from the object side to the image side. During zooming, at least the second lens group and the fourth lens group move. The subsequent group can be configured to include a focusing group that moves along the optical axis during focusing.

[0044] The "focal length" used in the conditional expressions is the paraxial focal length. Unless otherwise specifically stated, the "distance on the optical axis" used in the conditional expressions is the geometric distance. Unless otherwise specifically stated, the values used in the conditional expressions are the values based on the d-line in the state of focusing on an infinitely distant object. Regarding the signs of the radii of curvature, the sign of the surface with the convex shape facing the object side is set to positive, and the sign of the surface with the convex shape facing the image side is set to negative. The "d-line", "C-line", and "F-line" described in this specification are bright lines. The wavelength of the d-line is regarded as 587.56 nm (nanometers), the wavelength of the C-line is regarded as 656.27 nm (nanometers), and the wavelength of the F-line is regarded as 486.13 nm (nanometers).

[0045] Advantages of the Invention

[0046] According to the present invention, an optical system with a high-quality appearance can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 Corresponding to the optical system of Embodiment 1, it is a cross-sectional view showing the structure of the optical system according to one embodiment.

[0048] Figure 2 It is a diagram for explaining the edge surface.

[0049] Figure 3 It shows Figure 1 the structure of the optical system and a cross-sectional view of the light beam.

[0050] Figure 4 It is a diagram showing the parallel light beam incident on Figure 1 a partial enlarged view of the optical system.

[0051] Figure 5 It is a diagram for explaining the notations of the conditional expressions.

[0052] Figure 6 It is a diagram for explaining the notations of the conditional expressions.

[0053] Figure 7 It is the aberration diagrams of the optical system of Embodiment 1.

[0054] Figure 8 It is a cross-sectional view showing the structure of the optical system of Embodiment 2.

[0055] Figure 9 It is the aberration diagrams of the optical system of Embodiment 2.

[0056] Figure 10 It is a cross-sectional view showing the structure of the optical system of Embodiment 3.

[0057] Figure 11 It is the aberration diagrams of the optical system of Embodiment 3.

[0058] Figure 12 is a cross-sectional view showing the structure of the optical system of Example 4.

[0059] Figure 13 are aberration diagrams of the optical system of Example 4.

[0060] Figure 14 is a cross-sectional view showing the structure of the optical system of Example 5.

[0061] Figure 15 are aberration diagrams of the optical system of Example 5. Detailed Embodiments

[0062] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0063] Figure 1 shows a structural diagram of a cross-section including the optical axis Z of the optical system according to an embodiment of the present invention. In Figure 1 the left side is the object side and the right side is the image side. Figure 1 The example shown corresponds to the optical system of Example 1 described later. Figure 1 The optical system of can be used as an imaging lens for a digital camera, for example.

[0064] The optical system of the present invention includes at least one lens component. In this specification, one single lens or one cemented lens is regarded as one lens component. A single lens is one uncemented lens.

[0065] As an example, Figure 1 the optical system of includes nine lens components C1 to C9 arranged in order from the object side to the image side along the optical axis Z. In Figure 1 the optical system of , lens component C1 is the lens component closest to the object side, and lens component C9 is the lens component closest to the image side. An aperture stop St is disposed between lens component C5 and lens component C6. Figure 1 The aperture stop St shown in indicates the position in the optical axis direction, rather than the size and shape.

[0066] Figure 1The lens components of each example are configured as follows. The lens component C1 is composed of the lens L1 which is a single lens. The lens component C2 is composed of a cemented lens formed by cementing the lens L2 and the lens L3. The lens component C3 is composed of a cemented lens formed by cementing the lens L4 and the lens L5. The lens component C4 is composed of the lens L6 which is a single lens. The lens component C5 is composed of the lens L7 which is a single lens. The lens component C6 is composed of a cemented lens formed by cementing the lens L8 and the lens L9. The lens component C7 is composed of a cemented lens formed by cementing the lens L10 and the lens L11. The lens component C8 is composed of the lens L12 which is a single lens. The lens component C9 is composed of the lens L13 which is a single lens.

[0067] In addition, in Figure 1 the example, an example is shown in which an optical component PP in the shape of a parallel flat plate is disposed between the lens closest to the image side and the image plane Sim on the assumption that the optical system is applied to an imaging device. The optical component PP is a component assuming various filters and / or cover glasses, etc. The various filters are a low-pass filter, an infrared cut-off filter, and / or a filter for cutting off a specific wavelength region, etc. The optical component PP is a component having no refractive power. The optical component PP can also be omitted to configure the imaging device.

[0068] When observing the optical system from the object side or the image side, the outer peripheral surface of the lens of the optical system such as the imaging lens, especially the outer peripheral surface parallel to the optical axis Z, can be visually recognized by external light, and sometimes the appearance quality is impaired. Therefore, in the technology of the present invention, a film 2 for suppressing light reflection is provided on the outer peripheral surface of the preset lens. In order to suppress internal surface reflection and make the outer peripheral surface of the lens inconspicuous when observing from the object side, a low reflectance is preferred, and thus the film 2 is configured such that the light reflectance is less than 30%. Here, the "light reflectance less than 30%" means that the average value of the reflectance at the interface between the lens surface and the film 2 in the wavelength range of 400 to 700 nm is less than 30%. The reflectance of the film 2 is preferably less than 25%, more preferably less than 20%, further preferably less than 15%, and still further preferably less than 10%. The reflectance of the film 2 can be measured, for example, using a microspectrophotometer USPM-RU manufactured by Olympus Corporation.

[0069] As the film 2, for example, a black paint can be used. Specifically, as the film 2, GT-7II Fine manufactured by Canon Chemicals Inc., GT-1000 manufactured by Canon Chemicals Inc., MacRon for lens inking manufactured by FIT corporation, and Epoxy Ink 1000 manufactured by Seiko advance Ltd. can be used.

[0070] In Figure 1In [description], the film 2 is emphasized for easy understanding. Figure 1 The thickness of the film 2 in Figure 1 is not accurate. Also, in Figure 1 In the example of Figure 1 , the film 2 is provided on the outer peripheral surface in the circumferential direction above and below the optical axis Z. However, to prevent the figure from being complicated, the reference numeral is only marked on the film 2 below the optical axis Z. This method of showing the film 2 is the same in other figures.

[0071] The film 2 is mainly provided on the edge surface. In this specification, in the lens and lens components, the outer peripheral surface parallel to the optical axis Z is called the edge surface. The "outer peripheral surface parallel to the optical axis Z" mentioned here refers to the outer peripheral surface seen parallel to the optical axis Z in the cross-section including the optical axis Z. Refer to Figure 2 for the description of the outer peripheral surface of the lens.

[0072] Figure 2 Fig. [figure number] shows a cross-sectional view of the lens in the cross-section including the optical axis Z. In Figure 2 [description], the left side is set as the object side and the right side is set as the image side. Figure 2 The lens is configured to be rotationally symmetric about the optical axis Z and has a stepped shape on the outer peripheral surface. In Figure 2 [description], for illustration, five points, point P1 to point P5, are marked as points on the cross-section of the lens.

[0073] Figure 2 In [description], the region from point P1 to point P2 is the outer peripheral surface parallel to the optical axis Z and is the edge surface Sc1. The region from point P3 to point P4 is also the outer peripheral surface parallel to the optical axis Z and is the edge surface Sc2. As shown in the example of Figure 2 [description], when one lens has a plurality of outer peripheral surfaces parallel to the optical axis Z, all the plurality of outer peripheral surfaces parallel to the optical axis Z are collectively called the edge surface.

[0074] Figure 2 In [description], the region from point P1 to point P5 and the region from point P2 to point P3 are the outer peripheral surfaces perpendicular to the optical axis Z. In this specification, the outer peripheral surface perpendicular to the optical axis Z is called the plane chamfered surface.

[0075] In addition, the "parallel" and "perpendicular" in the description of this specification include the errors generally allowed in the technical field to which the technology of the present invention belongs. The error of parallelism is within the range of -5 degrees or more and +5 degrees or less with respect to the inclination angle of the optical axis Z, preferably within the range of -3 degrees or more and +3 degrees or less, and more preferably within the range of -1 degree or more and +1 degree or less. The smaller the error of parallelism, the more beneficial it is for the high-precision assembly of the optical system.

[0076] Although it is also considered to provide the film 2 in all lens components, compared with the case where the film 2 is not provided, the manufacturing process increases when the film 2 is provided. Therefore, when the number of lens components with the film 2 is small, it is beneficial to reduce costs. Moreover, providing the film 2 in the lens component means forming the film 2 on the outer peripheral surface of the lens. Therefore, when the thickness of the film 2 is uneven, eccentricity may occur. Thus, when aiming for a high-quality appearance, it is not always necessary to provide the film 2 in the lens components without problems in appearance. Hereinafter, the range where the film 2 is provided will be described.

[0077] First, the case of observing the optical system from the object side will be described. When observing the optical system from the object side, the edge surface of the lens near the object side can be visually recognized almost. And when the lens length is set to TD, the range from the lens surface closest to the object side of the optical system to 0.3×TD on the image side along the optical axis is the range that is easily visually recognized when observing the optical system from the object side. In addition, TD is defined as the distance on the optical axis from the lens surface closest to the object side of the optical system to the lens surface closest to the image side of the optical system. As an example, in Figure 1 the lens length TD is shown.

[0078] For the sake of convenience of explanation, the range from the lens surface closest to the object side of the optical system to 0.3×TD on the image side along the optical axis is referred to as the "front-side visually recognizable range". In Figure 1 the example of, in the two ranges indicated as "0.3×TD", the range indicated as "0.3×TD" on the object side corresponds to the front-side visually recognizable range.

[0079] The lens component in the lens components included in the optical system, in which at least a part of the lens component is in the front-side visually recognizable range on the optical axis, is referred to as the "front-side lens component". That is, the lens component in the lens components included in the optical system, in which the surface closest to the object side of the lens component is in the front-side visually recognizable range on the optical axis, is referred to as the "front-side lens component". In Figure 1 the example of, the lens component C1 and the lens component C2 respectively correspond to the front-side lens components.

[0080] In the technology of the present invention, it is configured that the film 2 is provided at 50% or more of the total area of the edge surfaces of all the front-side lens components. According to this structure, when observing the optical system from the object side, the situation of visually recognizing the edge surfaces can be alleviated, so that a high-quality appearance can be maintained. Moreover, by providing the film 2 on the edge surfaces, the ghosting and flare caused by the reflection inside the optical system can be suppressed, so that it can contribute to maintaining good performance.

[0081] In order to maintain a higher-quality appearance, it is preferable to provide the film 2 at more than 60% of the total area of the edge surfaces of all the front-side lens components, more preferably at more than 65%, and still more preferably at more than 75%.

[0082] In the Figure 1 example, the total area of the edge surfaces of the front-side lens components is the sum of the areas of the edge surfaces of all the lenses L1 to L3. In the Figure 1 example, the film 2 is provided over the entire surface of all the edge surfaces of the lenses L1 to L3, and thus the film 2 is provided at 100% of the total area of the edge surfaces of the front-side lens components.

[0083] In addition, depending on the specifications required for the optical system, etc., the film 2 may also be provided on the outer peripheral surface other than the edge surface and / or on the outer peripheral surface of the lens components other than the front-side lens components. For example, in the Figure 1 example, the film 2 is also provided on the flat chamfered surfaces of the lens L1 and the lens L2. And in the Figure 1 example, the film 2 is provided on the outer peripheral surfaces of the lens components C3 and C4. By providing the film 2 on the outer peripheral surface, it is possible to suppress ghosts and flare caused by reflections inside the optical system, and thus it is possible to contribute to maintaining good performance.

[0084] The optical system of the present invention is preferably an optical system that satisfies the following conditional expression (1). Here, the open F-number of the optical system in the state of focusing on an infinitely distant object is set as FNo. The maximum half-angle of view of the optical system in the state of focusing on an infinitely distant object is set as ω. Tan is the tangent. In the case where the optical system is a zoom optical system, FNo and ω are set as the values at the wide-angle end. As an example, the maximum half-angle of view ω is shown in Figure 3 . Figure 3 is a diagram showing the on-axis beam 4 and the off-axis beam 6 of the maximum half-angle of view ω together in a cross-sectional view of the Figure 1 optical system.

[0085] 1 < FNo / tan ω < 10 (1)

[0086] According to the optical system of the present invention, by not making the corresponding value of the conditional expression (1) exceed the upper limit, it is possible to realize an optical system that ensures a small open F-number and / or a wide angle of view and has a high-quality appearance.

[0087] By not making the corresponding value of the conditional expression (1) fall below the lower limit, good optical performance can be obtained and it is easy to suppress an increase in the number of lens elements and the enlargement of the optical system.

[0088] Figure 1The optical system is configured to have a small F-number and a wide angle. In an optical system with a small F-number and a wide angle, the diameter of the lens closest to the object side becomes larger, and a large number of negative lenses with strong refractive power are arranged on the object side. In such an optical system, since light is strongly diverged by the negative lens with strong refractive power, the outer peripheral surface of the lens is easily visible. Figure 4 shows the case where a light beam 8 parallel to the optical axis Z is incident from the object side into Figure 1 the optical system and the light beam is diverged by the lenses L1 and L2. The lenses L1 and L2 are negative lenses. In Figure 4 , for ease of understanding, the light beam 8 is illustrated as a group of light rays. The lens L3 is a positive lens. Generally, compared with a positive lens, the outer peripheral area of a negative lens is larger, so the outer peripheral surface of the negative lens is more easily visible than that of the positive lens. Based on these circumstances, in an optical system with a small F-number and a wide angle, when observing the optical system from the object side, the outer peripheral surface of the lens on the object side is easily visible. Therefore, by preventing the corresponding value of conditional expression (1) from falling below the lower limit, it is possible to suppress the outer peripheral surface of the lens on the object side from being easily visible when observing the optical system from the object side.

[0089] To obtain better characteristics, it is preferable to set it to any one of 9, 8, 7, and 6 instead of the upper limit 10 of conditional expression (1). And it is preferable to set it to any one of 1.2, 1.4, 1.6, and 1.8 instead of the lower limit 1 of conditional expression (1).

[0090] In the optical system of the present invention, it is preferable to provide the film 2 at 50% or more of the total area of the edge surfaces of all the front-side lens components that satisfy the following conditional expression (2). In this specification, the intersection of the lens surface closest to the object side of the optical system and the optical axis Z is referred to as the "front-side intersection point", and for each front-side lens component, the notations are defined as follows. Let the angle formed by the line connecting the front-side intersection point and the point on the edge surface closest to the object side and the optical axis Z be αf. Let the angle formed by the line connecting the front-side intersection point and the point on the edge surface closest to the image side and the optical axis Z be βf. The units of αf and βf are degrees. As an example, in Figure 5 shows the angles αf and βf with respect to Figure 1 the lens component C2. In the example of Figure 5 , the intersection of the object-side surface of the lens L1 and the optical axis Z corresponds to the front-side intersection point.

[0091] 2.7° < αf - βf < 40° (2)

[0092] The area of the edge surface of the lens component satisfying conditional expression (2) is relatively large, so the edge surface is likely to be seen when viewed from the object side. By disposing film 2 at 50% or more of the total area of the edge surfaces of all the front lens components satisfying conditional expression (2), reflection on the edge surfaces of these lens components can be suppressed, and thus the situation where the edge surface is visually recognized when the optical system is viewed from the object side can be alleviated. Thereby, a high-quality appearance can be maintained.

[0093] To maintain an even higher-quality appearance, it is more preferable that film 2 is disposed at 60% or more of the total area of the edge surfaces of all the front lens components satisfying conditional expression (2), further preferably at 65% or more, and even more preferably at 75% or more.

[0094] In the optical system of the present invention, it is preferable that the proportion of the area where film 2 is disposed in the total area of the edge surfaces of all the front lens components satisfying the following conditional expressions (3) and (4) is 30% or less. Here, N is a natural number of 2 or more. For the N-th front lens component starting from the object side, angles αf and βf are defined in the same manner as in the case of conditional expression (2). Also, the combined focal length from the front lens component closest to the object side to the (N - 1)-th front lens component starting from the object side is set as ff. In addition, the above "30% or less" also includes 0%. That is, film 2 may not be disposed at all on the entire surface of the edge surfaces of all the front lens components satisfying conditional expressions (3) and (4).

[0095] 1.1° < αf - βf ≤ 2.7° (3)

[0096] -2.4 < TD / ff (4)

[0097] The area of the edge surface of the lens component satisfying conditional expression (3) is relatively large, but depending on the shape and focal length of the surrounding lenses, etc., it is sometimes difficult to see the outer peripheral surface even when viewed from the object side. By satisfying conditional expression (4), the light beam reaching the N-th front lens component starting from the object side becomes convergent light or weakly divergent light, so it is difficult to see the outer peripheral surface of this lens component when viewed from the object side. Therefore, in an optical system where the proportion of the area where film 2 is disposed in the total area of the edge surfaces of all the front lens components satisfying conditional expressions (3) and (4) is 30% or less, the area of film 2 disposed on the edge surface of the front lens component is small, but it is difficult to see the outer peripheral surface of the lens component when viewed from the object side, so a high-quality appearance can be maintained. By reducing the area of film 2 disposed in the lens component where the outer peripheral surface is difficult to see, as described above, it is beneficial for cost reduction and eccentricity reduction.

[0098] By reducing the area of the film 2, it is beneficial to reduce costs and eccentricity. Therefore, in the total area of the edge surfaces of all the front lens components that satisfy the conditional expressions (3) and (4), the proportion of the area where the film 2 is provided is more preferably 20% or less, further preferably 15% or less, and even more preferably 10% or less.

[0099] In order to maintain a higher-quality appearance, it is preferable to set it to any one of -2.2, -2, -1.8, -1.6, and -1.4 instead of the lower limit -2.4 of the conditional expression (4). The TD / ff of the conditional expression (4) is preferably less than 10. In this case, compared with the Nth front lens component from the object side, the combined refractive power of all the lens components on the object side will not become too strong, so it is advantageous for aberration correction.

[0100] Moreover, in the optical system of the present invention, it is preferable that in the total area of the edge surfaces of all the front lens components that satisfy the following conditional expressions (3) and (5), the proportion of the area where the film 2 is provided is 30% or less. Here, N is a natural number of 2 or more. For the Nth front lens component from the object side, the angles αf and βf are defined in the same way as above. Also, the paraxial curvature radius of the most image-side surface of the Nth front lens component from the object side is set as Rf. In addition, the above "30% or less" also includes 0%. That is, it is also possible to not provide the film 2 at all on the entire edge surface of all the front lens components that satisfy the conditional expressions (3) and (5).

[0101] 1.1° < αf - βf ≤ 2.7° (3)

[0102] TD / Rf < 2.4 (5)

[0103] As described above, among the lens components that satisfy the conditional expression (3), sometimes it is difficult to see the outer peripheral surface even when viewed from the object side. By satisfying the conditional expression (5), the most image-side surface of the Nth front lens component from the object side becomes a convex surface or a concave surface with a relatively large curvature radius. Therefore, it is difficult to see the outer peripheral surface of this lens component when viewed from the object side. Thus, in an optical system where the proportion of the area where the film 2 is provided in the total area of the edge surfaces of all the front lens components that satisfy the conditional expressions (3) and (5) is 30% or less, the area of the film 2 provided on the edge surface of the front lens component is small, but it is difficult to see the outer peripheral surface of the lens component when viewed from the object side. Therefore, a high-quality appearance can be maintained. By reducing the area of the film 2 provided in the lens component where the outer peripheral surface is difficult to see, as described above, it is beneficial to reduce costs and eccentricity.

[0104] By reducing the area of the film 2, it is beneficial to reduce costs and eccentricity. Therefore, the proportion of the area of the film 2 in the total area of the edge surfaces of all the front lens components that satisfy the conditional expressions (3) and (5) is more preferably 20% or less, further preferably 15% or less, and even more preferably 10% or less.

[0105] In order to maintain a higher-quality appearance, it is preferable to set it to any one of 2.2, 2, 1.8, 1.6, 1.4, 1.2, 1, 0.8, and 0.77 to replace the upper limit of 2.4 in the conditional expression (5). TD / Rf in the conditional expression (5) is preferably greater than -10. In this case, since the absolute value of the radius of curvature of the most image-side surface of the Nth front lens component starting from the object side does not become too small, good workability can be maintained, and the refractive power of this surface does not become too strong, so it is also advantageous for aberration correction.

[0106] In the optical system of the present invention, the proportion of the area of the film 2 in the total area of the edge surfaces of all the front lens components that satisfy the following conditional expression (10) is preferably 30% or less. Here, for each front lens component, the angles αf and βf are defined in the same manner as above. In addition, the above "30% or less" also includes 0%. That is, the film 2 can be not provided at all on the entire edge surface of all the front lens components that satisfy the conditional expression (10).

[0107] 0° < αf - βf ≤ 1.1° (10)

[0108] The length (edge thickness) of the edge surface of the lens component that satisfies the conditional expression (10) in the optical axis direction is short and the area of the edge surface is small, so it is difficult to see the outer peripheral surface even when viewed from the object side. Therefore, in an optical system in which the proportion of the area of the film 2 in the total area of the edge surfaces of all the front lens components that satisfy the conditional expression (10) is 30% or less, the area of the film 2 provided on the edge surface of the front lens component is small, but it is difficult to see the outer peripheral surface of the lens component when viewed from the object side, so a high-quality appearance can be maintained. By reducing the area of the film 2 provided in the lens component where the outer peripheral surface is difficult to see, as described above, it is beneficial to reduce costs and eccentricity.

[0109] By reducing the area of the film 2, it is beneficial to reduce costs and eccentricity. Therefore, the proportion of the area of the film 2 in the total area of the edge surfaces of all the front lens components that satisfy the conditional expression (10) is more preferably 20% or less, further preferably 15% or less, and even more preferably 10% or less.

[0110] Next, the case of observing the optical system from the image side will be described. The case of observing the optical system from the image side can also be considered in the same way as the case of observing the optical system from the object side. When observing the optical system from the image side, the edge surface of the lens closer to the image side can be visually recognized almost. And, the range from the lens surface closest to the image side of the optical system to the object side up to 0.3×TD on the optical axis is an easily visually recognizable range when observing the optical system from the image side.

[0111] For the sake of convenience in explanation, the range from the lens surface closest to the image side of the optical system to the object side up to 0.3×TD is referred to as the "rear-side visually recognizable range". In Figure 1 the example of, in the two ranges expressed as "0.3×TD", the range of "0.3×TD" on the image side corresponds to the rear-side visually recognizable range.

[0112] Among the lens components included in the optical system, the lens component in which at least a part of the lens component is located within the rear-side visually recognizable range on the optical axis is referred to as the "rear-side lens component". That is, among the lens components included in the optical system, the lens component in which the surface closest to the image side of the lens component is located within the rear-side visually recognizable range on the optical axis is referred to as the "rear-side lens component". In Figure 1 the example of, the lens component C6, the lens component C7, the lens component C8, and the lens component C9 respectively correspond to the rear-side lens components.

[0113] In the technology of the present invention, it is configured to provide the film 2 at 50% or more of the total area of the edge surfaces of all the rear-side lens components. According to this structure, when observing the optical system from the image side, the situation of visually recognizing the edge surface can be alleviated, so that a high-quality appearance can be maintained. And, by providing the film 2 on the edge surface, the ghosting and flare caused by the reflection inside the optical system can be suppressed, so that it can contribute to maintaining good performance.

[0114] In order to maintain a higher-quality appearance, it is more preferable to provide the film 2 at 60% or more of the total area of the edge surfaces of all the rear-side lens components, further preferably at 65% or more, and even more preferably at 75% or more.

[0115] In Figure 1 the example of, the total area of the edge surfaces of the rear-side lens components is the sum of the areas of all the edge surfaces of the lenses L8 to L13. In Figure 1 the example of, the film 2 is provided on the entire surface of all the edge surfaces of the lenses L8 to L13, so the film 2 is provided at 100% of the total area of the edge surfaces of the rear-side lens components.

[0116] The optical system of the present invention preferably has a film 2 provided at 50% or more of the total area of the edge surfaces of all the rear lens components that satisfy the following conditional expression (6). In the present specification, the intersection point of the lens surface closest to the image side of the optical system and the optical axis Z is referred to as the "rear intersection point", and the following notations are defined for each rear lens component. Let the angle formed by the line connecting the rear intersection point and the point on the edge surface closest to the image side and the optical axis Z be αr. Let the angle formed by the line connecting the rear intersection point and the point on the edge surface closest to the object side and the optical axis Z be βr. Let the unit of αr and βr be degrees. As an example, in Figure 6 shows the angles αr and βr with respect to Figure 1 the lens component C7. In the example of Figure 6 , the intersection point of the image-side surface of the lens L13 and the optical axis Z corresponds to the rear intersection point.

[0117] 2.7° < αr - βr < 40° (6)

[0118] The area of the edge surface of the lens component that satisfies the conditional expression (6) is large, so the edge surface is easily visible when viewed from the image side. By providing the film 2 at 50% or more of the total area of the edge surfaces of all the rear lens components that satisfy the conditional expression (6), reflection on the edge surfaces of these lens components can be suppressed, and thus the situation where the edge surface is visually recognized when the optical system is viewed from the image side can be alleviated. Thereby, a high-quality appearance can be maintained.

[0119] To maintain an even higher-quality appearance, it is more preferable that the film 2 is provided at 60% or more of the total area of the edge surfaces of all the rear lens components that satisfy the conditional expression (6), further preferably at 65% or more, and even more preferably at 75% or more.

[0120] The optical system of the present invention preferably has the proportion of the area of the film 2 provided in the total area of the edge surfaces of all the rear lens components that satisfy the following conditional expressions (7) and (8) being 30% or less. Here, let M be a natural number of 2 or more. For the M-th rear lens component starting from the object side, the angles αr and βr are defined in the same manner as in the case of the conditional expression (6). And let the combined focal length from the rear lens component closest to the image side to the (M - 1)-th rear lens component starting from the image side be fr. In addition, the above "30% or less" also includes 0%. That is, it is also possible to not provide the film 2 at all on the entire surface of the edge surfaces of all the rear lens components that satisfy the conditional expressions (7) and (8).

[0121] 1.1° < αr - βr ≤ 2.7° (7)

[0122] -2.4 < TD / fr (8)

[0123] The area of the marginal surface of the lens component that satisfies conditional expression (7) is relatively large. However, depending on the shape and focal length of the surrounding lenses, etc., the outer peripheral surface may sometimes be difficult to see even when viewed from the image side. By satisfying conditional expression (8), the light beam reaching the M-th rear lens component from the image side becomes convergent light or weakly divergent light. Therefore, the outer peripheral surface of this lens component is difficult to see when viewed from the image side. Thus, in an optical system where the proportion of the area where film 2 is provided in the total area of the marginal surfaces of all rear lens components that satisfy conditional expressions (7) and (8) is 30% or less, the area where film 2 is provided on the marginal surface of the rear lens component is small, but the outer peripheral surface of the lens component is difficult to see when viewed from the image side. Therefore, a high-quality appearance can be maintained. By reducing the area where film 2 is provided in the lens component where the outer peripheral surface is difficult to see, as described above, it is beneficial for cost reduction and eccentricity reduction.

[0124] By reducing the area where film 2 is provided, it is beneficial for cost reduction and eccentricity reduction. Therefore, in the total area of the marginal surfaces of all rear lens components that satisfy conditional expressions (7) and (8), the proportion of the area where film 2 is provided is more preferably 20% or less, further preferably 15% or less, and even more preferably 10% or less.

[0125] In order to maintain an even higher-quality appearance, it is preferable to set it to any one of -2.2, -2, -1.8, -1.7, and -1.6 instead of the lower limit of -2.4 of conditional expression (8). TD / fr of conditional expression (8) is preferably less than 10. In this case, compared with the M-th rear lens component from the image side, the combined refractive power of all lens components on the image side does not become too strong. Therefore, it is advantageous for aberration correction.

[0126] Moreover, in the optical system of the present invention, it is preferable that the proportion of the area where film 2 is provided in the total area of the marginal surfaces of all rear lens components that satisfy the following conditional expressions (7) and (9) is 30% or less. Here, M is a natural number of 2 or more. For the M-th rear lens component from the image side, the paraxial curvature radius of the surface closest to the object side is defined as Rr in the same manner as above. In addition, the above "30% or less" also includes 0%. That is, it is also possible to not provide film 2 at all on the entire marginal surface of all rear lens components that satisfy conditional expressions (7) and (9).

[0127] 1.1°<αr-βr≤2.7° (7)

[0128] -10<TD / Rr (9)

[0129] As described above, in the lens component satisfying conditional expression (7), it is sometimes difficult to see the outer peripheral surface even when viewed from the image side. By satisfying conditional expression (9), the surface closest to the object side of the M-th rear lens component counted from the image side becomes a convex surface or a concave surface with a relatively large absolute value of the radius of curvature, and thus it is difficult to see the outer peripheral surface of this lens component when viewed from the image side. Therefore, in an optical system in which the proportion of the area where the film 2 is provided in the total area of the edge surfaces of all the rear lens components satisfying conditional expressions (7) and (9) is 30% or less, the area where the film 2 is provided on the edge surface of the rear lens component is small, but it is difficult to see the outer peripheral surface of the lens component when viewed from the image side, and thus a high-quality appearance can be maintained. By reducing the area where the film 2 is provided in the lens component where the outer peripheral surface is difficult to see, as described above, it is beneficial to reduce costs and reduce eccentricity.

[0130] By reducing the area where the film 2 is provided, it is beneficial to reduce costs and reduce eccentricity. Therefore, the proportion of the area where the film 2 is provided in the total area of the edge surfaces of all the rear lens components satisfying conditional expressions (7) and (9) is preferably 20% or less, more preferably 15% or less, and even more preferably 10% or less.

[0131] In order to maintain an even higher-quality appearance, it is preferable to set it to any one of -9, -8, -7, -6, -5, -4, -3, -2, and -1.1 instead of the lower limit of -10 of conditional expression (9). TD / Rr of conditional expression (9) is preferably less than 10. In this case, the radius of curvature of the surface closest to the object side of the M-th rear lens component counted from the image side does not become too small, and thus good workability can be maintained, and the refractive power of this surface does not become too strong, which is also advantageous for aberration correction.

[0132] In the optical system of the present invention, the proportion of the area where the film 2 is provided in the total area of the edge surfaces of all the rear lens components satisfying the following conditional expression (11) is preferably 30% or less. Here, for each rear lens component, the angles αr and βr are defined in the same manner as above. In addition, the above "30% or less" also includes 0%. That is, the film 2 can be completely not provided on the entire surface of the edge surfaces of all the rear lens components satisfying conditional expression (11).

[0133] 0°<αr-βr≤1.1° (11)

[0134] The length in the optical axis direction (edge thickness) of the edge surface of the lens component satisfying the conditional expression (11) is short and the area of the edge surface is small, so it is difficult to see the outer peripheral surface even when viewed from the image side. Therefore, in an optical system in which the proportion of the area where the film 2 is provided in the total area of the edge surfaces of all the rear lens components satisfying the conditional expression (11) is 30% or less, the area where the film 2 is provided on the edge surface of the rear lens component is small, but it is difficult to see the outer peripheral surface of the lens component when viewed from the image side, so a high-quality appearance can be maintained. By reducing the area where the film 2 is provided in the lens component where the outer peripheral surface is difficult to see, as described above, it is beneficial to reduce costs and reduce eccentricity.

[0135] By reducing the area where the film 2 is provided, it is beneficial to reduce costs and reduce eccentricity. Therefore, the proportion of the area where the film 2 is provided in the total area of the edge surfaces of all the rear lens components satisfying the conditional expression (11) is more preferably 20% or less, further preferably 15% or less, and even more preferably 10% or less.

[0136] If both the object side and the image side are considered, in the optical system of the present invention, it is preferable that the proportion of the area where the film 2 is provided in the total area of the edge surfaces of all the front lens components satisfying the conditional expression (10) and all the rear lens components satisfying the conditional expression (11) is 30% or less. In addition, the above "30% or less" also includes 0%. That is, the film 2 may not be provided at all on the entire surfaces of the edge surfaces of all the front lens components satisfying the conditional expression (10) and all the rear lens components satisfying the conditional expression (11).

[0137] By reducing the area where the film 2 is provided, it is beneficial to reduce costs and reduce eccentricity. Therefore, the proportion of the area where the film 2 is provided in the total area of the edge surfaces of all the front lens components satisfying the conditional expression (10) and all the rear lens components satisfying the conditional expression (11) is more preferably 20% or less, further preferably 15% or less, and even more preferably 10% or less.

[0138] In addition, Figure 1 The example shown is just an example, and various modifications can be made without departing from the gist of the technology of the present invention. The technology of the present invention can be applied only to the front lens component, or only to the rear lens component, or to both the front lens component and the rear lens component. And, the optical system of the present invention can be a fixed-focus optical system or a zoom optical system.

[0139] Figure 14 An example of the zoom optical system of the present invention is shown. Figure 14 The example shown corresponds to Example 5 described later. As Figure 14As shown, the zoom optical system of the present invention can be configured to sequentially include a first lens group G1 with positive refractive power and a subsequent group GR including at least one lens group from the object side to the image side, and during zooming, the interval between adjacent lens groups changes. According to this structure, aberration variation during zooming from the wide-angle end to the telephoto end can be suppressed.

[0140] The subsequent group GR of the above zoom optical system can be configured to include a second lens group G2 with negative refractive power on the object side. According to this structure, aberration variation during zooming from the wide-angle end to the telephoto end can be suppressed. More specifically, the subsequent group GR can be configured to sequentially and continuously include the second lens group G2, the third lens group G3, and the fourth lens group G4 from the object side to the image side, and during zooming, at least the second lens group G2 and the fourth lens group G4 move. In this case, it is beneficial to realize an optical system with a high zoom ratio and small aberration variation during zooming. Also, the subsequent group GR can be configured to include a focusing group that moves along the optical axis Z during focusing. In this case, it is easy to reduce the effective diameter of the focusing group, so it is easy to make the focusing group lightweight, which is beneficial for performing the focusing operation quickly and with high precision.

[0141] In the technology of the present invention, the optical system of the present invention can be a zoom optical system with a structure different from the Figure 14 example shown. When the optical system is a zoom optical system, it is sufficient to have the structure of the technology of the present invention at at least one of the wide-angle end and the telephoto end. This is because when a user observes the appearance of the lens of the optical system, it is mostly in the state of the wide-angle end or the telephoto end.

[0142] Also, in a system in which a part of the optical system is configured to move during focusing, the value of the above conditional expression is set to the value in the state of focusing on an infinitely distant object.

[0143] The above preferred structures and possible structures can be any combination, and it is preferably selectively adopted appropriately according to the required specifications.

[0144] For example, a preferred embodiment of the optical system of the present invention is an optical system including at least one lens component. In this optical system, the outer peripheral surface parallel to the optical axis Z of the lens component is defined as the edge surface, the distance on the optical axis from the lens surface closest to the object side of the optical system to the lens surface closest to the image side of the optical system is defined as TD, and when at least a part of the lens components included in the optical system is located within the range of 0.3×TD from the lens surface closest to the object side of the optical system toward the image side on the optical axis, and the lens components are defined as front-side lens components, a film 2 with a light reflectivity of less than 30% is provided at 50% or more of the total area of the edge surfaces of all the front-side lens components. The reflectivity of the film 2 is preferably less than 25%, more preferably less than 20%, further preferably less than 15%, and even more preferably less than 10%.

[0145] Another preferred embodiment of the optical system of the present invention is an optical system including at least one lens component. In this optical system, the outer peripheral surface parallel to the optical axis Z of the lens component is defined as the edge surface, the distance on the optical axis from the lens surface closest to the object side of the optical system to the lens surface closest to the image side of the optical system is defined as TD, and when at least a part of the lens components included in the optical system is located within the range of 0.3×TD from the lens surface closest to the image side of the optical system toward the object side on the optical axis, and the lens components are defined as rear-side lens components, a film 2 with a light reflectivity of less than 30% is provided at 50% or more of the total area of the edge surfaces of all the rear-side lens components. The reflectivity of the film 2 is preferably less than 25%, more preferably less than 20%, further preferably less than 15%, and even more preferably less than 10%.

[0146] Next, embodiments of the optical system of the present invention will be described with reference to the accompanying drawings. In addition, the reference signs of the lenses and lens components in the cross-sectional views of the respective embodiments are used independently for each embodiment to avoid complication of the description and the drawings due to an increase in the number of digits of the reference signs. Therefore, even if the same reference signs are marked in the drawings of different embodiments, they do not necessarily represent the same structure.

[0147] [Embodiment 1]

[0148] A cross-sectional view of the structure of the optical system of Embodiment 1 is shown in Figure 1, the illustration method and structure are as described above, so a part of the repeated description is omitted here. The optical system of Embodiment 1 includes lens components C1 to C5, an aperture stop St, and lens components C6 to C9 in order from the object side to the image side. Lens components C1 to C2 respectively correspond to the front lens components, and lens components C6 to C9 respectively correspond to the rear lens components. A film 2 is provided on the edge surfaces of lens components C1 to C4, C6 to C9. The focusing group is composed of lens components C6 to C9. When focusing from an infinite object to a near object, the lens components constituting the focusing group move integrally toward the object side. In addition, in this specification, "move integrally" means moving the same amount in the same direction simultaneously.

[0149] Regarding the optical system of Embodiment 1, the basic lens data is shown in Table 1, the specifications are shown in Table 2, and the aspherical coefficients are shown in Table 3.

[0150] The table of the basic lens data is described as follows. In the "Sn" column, the surface number is shown when the surface closest to the object side is set as the first surface and the numbers are incremented one by one toward the image side. In the "R" column, the curvature radius of each surface is shown. In the "D" column, the surface interval on the optical axis between each surface and the surface adjacent to its image side is shown. In the "Nd" column, the refractive index of each component with respect to the d-line is shown. In the "νd" column, the Abbe number of each component based on the d-line is shown. In the "Outer diameter" column, the outer diameter of each component, that is, the lens outer diameter, is shown. In the "Film" column, "Yes" is entered in the column of the component where the film 2 is provided on the edge surface, and "No" is entered in the column of the component where the film 2 is not provided on the edge surface. In the "α-β" column, the value of αf-βf is shown for the front lens component, and the value of αr-βr is shown for the rear lens component. "fC" is entered in the leftmost column of the surface corresponding to the front lens component, and "rC" is entered in the leftmost column of the surface corresponding to the rear lens component.

[0151] In the table of the basic lens data, the sign of the curvature radius of the surface with the convex shape facing the object side is set as positive, and the sign of the curvature radius of the surface with the convex shape facing the image side is set as negative. In the column of the surface number of the surface corresponding to the aperture stop St, the surface number and the statement (St) are entered. The optical component PP is also shown in the table of the basic lens data. The value in the bottom row of the column of the surface interval in the table is the interval between the surface closest to the image side in the table and the image plane Sim.

[0152] In Table 2, the focal length f, the back focal length Bf in terms of air equivalent distance, the aperture F-number FNo., the maximum full angle of view 2ω, the aperture stop diameter Stφ, the total length TI of the optical system, and the lens length TD are shown with respect to the d-line reference. The FNo. in Table 2 has the same meaning as the FNo. in conditional expression (1). The [°] in the column of the maximum full angle of view indicates that the unit is degrees. TI is the sum of the lens length TD and the back focal length Bf in terms of air equivalent distance. Stφ is the opening diameter of the aperture stop St when the aperture stop St is in the open state. The values in Table 2 show the state of focusing on an infinitely distant object.

[0153] In the table of the basic lens data, an asterisk mark is attached to the surface number of the aspherical surface, and the value of the paraxial radius of curvature is described in the column of the radius of curvature of the aspherical surface. In Table 3, the surface numbers of the aspherical surfaces are shown in the Sn row, and the values of the aspherical coefficients regarding each aspherical surface are shown in the KA and Am rows. In addition, m in Am is an integer of 3 or more and varies depending on the surface. For example, in the first surface of Example 1, m = 3, 4, 5, ……, 16. The “E±n” (n: integer) of the values of the aspherical coefficients in Table 3 means “×10 ±n ”. KA and Am are the aspherical coefficients in the aspherical formula represented by the following formula.

[0154] Zd = C × h 2 / {1 + (1 - KA × C 2 × h 2 ) 1 / 2}+ ∑Am × h m

[0155] Where,

[0156] Zd: Aspherical depth (the length of the perpendicular line dropped from a point on the aspherical surface at height h to the plane that is tangent to the vertex of the aspherical surface and perpendicular to the optical axis Z)

[0157] h: Height (the distance from the optical axis Z to the lens surface)

[0158] C: Reciprocal of the paraxial radius of curvature

[0159] KA, Am: Aspherical coefficients

[0160] The ∑ in the aspherical formula represents the sum with respect to m.

[0161] In the data of each table, degrees are used as the angular unit and mm (millimeter) is used as the length unit. However, since the optical system can also be used with a magnification ratio or a reduction ratio, other appropriate units can also be used. And, the values rounded off to a preset number of digits are described in each of the following tables.

[0162] [Table 1]

[0163] Example 1

[0164]

[0165] [Table 2]

[0166] Example 1

[0167] f 18.20 Bf 19.49 FNo. 1.44 2ω[°] 76.4 Stφ 23.07 TL 89.41 TD 69.92

[0168] [Table 3]

[0169] Example 1

[0170] Sn 1 2 22 23 KA -3.5524107E+00 -4.3839153E-01 -8.7749470E-01 -1.7564944E+00 A3 0.0000000E+00 0.0000000E+00 0.0000000E+00 0.0000000E+00 A4 1.4562563E-04 1.9987653E-04 -2.9457203E-04 4.5987345E-05 A5 -1.5586134E-05 -1.4237156E-05 -3.0213717E-05 -4.2734089E-05 A6 5.2002049E-07 3.8653493E-08 8.8294930E-06 8.3923312E-06 A7 4.4576460E-08 9.7639392E-08 -6.3236083E-07 -6.7249893E-07 A8 -7.2822532E-09 1.3127811E-10 6.6065017E-08 3.8700650E-08 A9 2.3897513E-10 -1.7402613E-09 -1.8681912E-08 -1.0369127E-09 A10 2.0729060E-11 1.0104915E-10 2.8496418E-09 -7.1101541E-10 A11 -4.2346876E-13 1.0980116E-11 -2.1192026E-10 1.4318222E-10 A12 -2.6304469E-13 -1.4408297E-12 5.7452181E-12 -4.3454846E-12 A13 2.7068251E-14 5.0098114E-14 1.3592773E-13 -1.7638060E-12 A14 -1.2272789E-15 2.0411475E-16 -3.2656663E-15 2.5353158E-13 A15 2.8191990E-17 -5.1685374E-17 -6.9338244E-16 -1.4072532E-14 A16 -2.6907030E-19 9.6690889E-19 2.5709964E-17 2.9452493E-16

[0171] Figure 7 The aberration diagrams of the optical system of Example 1 in the state of focusing on an infinitely distant object are shown. In Figure 7 it, the spherical aberration, astigmatism, distortion aberration, and longitudinal chromatic aberration are shown in order from the left. In the spherical aberration diagram, the aberrations of the d-line, C-line, and F-line are shown by solid line, long dashed line, and short dashed line, respectively. In the astigmatism diagram, the aberration of the d-line in the sagittal direction is shown by a solid line, and the aberration of the d-line in the meridional direction is shown by a short dashed line. In the distortion aberration diagram, the aberration of the d-line is shown by a solid line. In the longitudinal chromatic aberration diagram, the aberrations of the C-line and F-line are shown by long dashed line and short dashed line, respectively. In the spherical aberration diagram, the value of the open F-number is shown after "FNo. =". In the other aberration diagrams, the value of the maximum half field angle is shown after "ω =".

[0172] In Table 4, the presence or absence of the film 2 on the edge surface and the corresponding values of the above conditional expressions (1) to (5) and (10) are shown for each lens component of the front lens component. In Table 5, the presence or absence of the film 2 on the edge surface and the corresponding values of the above conditional expressions (6) to (9) and (11) are shown for each lens component of the rear lens component. In Tables 4 and 5, the numbers in parentheses before the conditional expressions indicate the numbers of the conditional expressions, and each lens component is represented by the corresponding reference symbol. For example, "C1" in Table 4 represents the lens component C1, and the values and information related to the lens component C1 are shown in the "C1" column. However, for the lens components that do not satisfy the conditional expression (3), the corresponding values of the conditional expressions (4) and (5) are omitted from the record, and for the lens components that do not satisfy the conditional expression (7), the corresponding values of the conditional expressions (8) and (9) are omitted from the record.

[0173] And, the values of the following ratios A to I are entered in Tables 4 and 5. The ratios A to I are all expressed as percentages. "No corresponding lens component" is entered in the parts where there is no corresponding lens component.

[0174] Ratio A: The ratio of the area where the film 2 is provided to the total area of the edge surface of the front lens component

[0175] Ratio B: The ratio of the area where Film 2 is provided to the total area of the edge surfaces of all front lens components that satisfy conditional expression (2).

[0176] Ratio C: The ratio of the area where Film 2 is provided to the total area of the edge surfaces of all front lens components that satisfy conditional expressions (3) and (4).

[0177] Ratio D: The ratio of the area where Film 2 is provided to the total area of the edge surfaces of all front lens components that satisfy conditional expressions (3) and (5).

[0178] Ratio E: The ratio of the area where Film 2 is provided to the total area of the edge surfaces of the rear lens component.

[0179] Ratio F: The ratio of the area where Film 2 is provided to the total area of the edge surfaces of all rear lens components that satisfy conditional expression (6).

[0180] Ratio G: The ratio of the area where Film 2 is provided to the total area of the edge surfaces of all rear lens components that satisfy conditional expressions (7) and (8).

[0181] Ratio H: The ratio of the area where Film 2 is provided to the total area of the edge surfaces of all rear lens components that satisfy conditional expressions (7) and (9).

[0182] Ratio I: The ratio of the area where Film 2 is provided to the total area of the edge surfaces of all front lens components that satisfy conditional expression (10) and all rear lens components that satisfy conditional expression (11).

[0183] [Table 4]

[0184] Example 1

[0185] (1) FNo / tanω = 1.830

[0186]

[0187] [Table 5]

[0188] Example 1

[0189]

[0190] Regarding the notations, meanings, recording methods, and illustration methods of the respective data related to Example 1 above, unless otherwise specified, they are basically the same in the following examples, so repeated explanations are omitted below.

[0191] [Example 2]

[0192] The cross-sectional view of the structure of the optical system of Example 2 is shown in Figure 8The optical system of Example 2 includes lens components C1 to C3, an aperture stop St, and lens components C4 to C9 in sequence from the object side to the image side. The lens component C1 is composed of a lens L1 which is a singlet lens. The lens component C2 is composed of a cemented lens formed by cementing a lens L2 and a lens L3. The lens component C3 is composed of a lens L4 which is a singlet lens. The lens component C4 is composed of a lens L5 which is a singlet lens. The lens component C5 is composed of a cemented lens formed by cementing a lens L6 and a lens L7. The lens component C6 is composed of a lens L8 which is a singlet lens. The lens component C7 is composed of a lens L9 which is a singlet lens. The lens component C8 is composed of a cemented lens formed by cementing a lens L10 and a lens L11. The lens component C9 is composed of a lens L12 which is a singlet lens.

[0193] The lens components C1 to C3 respectively correspond to the front lens components, and the lens components C6 to C9 respectively correspond to the rear lens components. Films 2 are provided on the edge surfaces of the lens components C1 to C2, C5 to C6, and C8 to C9. The focusing group is composed of the lens components C4 to C7. When focusing from an infinitely distant object to a close object, the lens components constituting the focusing group move integrally toward the object side.

[0194] Regarding the optical system of Example 2, the basic lens data are shown in Table 6, the specifications are shown in Table 7, the aspherical coefficients are shown in Table 8, and the aberration diagrams in the state of focusing on an infinitely distant object are shown in Figure 9 And, regarding the front lens components and rear lens components of the optical system of Example 2, the presence or absence of the film 2 on the edge surface, the corresponding values of the above conditional expressions (1) to (11), and the ratios A to I are shown in Tables 9 and 10.

[0195] [Table 6]

[0196] Example 2

[0197]

[0198] [Table 7] Example 2

[0199] f 34.01 Bf 13.24 FNo. 1.44 2ω[°] 45.4 Stφ 25.61 TL 76.07 TD 62.83

[0200] [Table 8]

[0201] Example 2

[0202] Sn 16 17 21 22 KA 1.0000000E+00 1.0000000E+00 1.0000000E+00 1.0000000E+00 A3 0.0000000E+00 0.0000000E+00 0.0000000E+00 0.0000000E+00 A4 -6.7892977E-06 2.6728027E-05 2.0699818E-05 -2.6025700E-05 A5 -3.4998037E-06 -3.1585103E-06 -3.5609821E-06 2.0701497E-05 A6 2.6708753E-07 3.6167193E-08 1.0411116E-06 -3.2441813E-06 A7 4.1719229E-08 5.7847224E-08 -4.6385997E-08 2.0830649E-07 A8 -4.6906387E-09 -3.6372615E-09 -1.0004409E-08 8.0249345E-09 A9 -2.1393790E-10 -3.2271859E-10 6.1558719E-10 -2.2013977E-09 A10 3.2807144E-11 2.9770156E-11 2.8180923E-11 7.4088106E-11 A11 3.7083422E-13 6.2009046E-13 -1.8453397E-12 4.8533222E-12 A12 -7.9543983E-14 -7.1537115E-14 -2.8600819E-14 -2.7168254E-13

[0203] [Table 9]

[0204] Example 2

[0205] (1) FNo / tanω = 3.442

[0206]

[0207] [Table 10]

[0208] Example 2

[0209]

[0210] [Example 3]

[0211] A cross-sectional view of the structure of the optical system of Example 3 is shown in Figure 10 . The optical system of Example 3 includes lens components C1 to C5, an aperture stop St, and lens components C6 to C10 in order from the object side to the image side. The lens component C1 is composed of a lens L1 that is a single lens. The lens component C2 is composed of a lens L2 that is a single lens. The lens component C3 is composed of a lens L3 that is a single lens. The lens component C4 is composed of a lens L4 that is a single lens. The lens component C5 is composed of a cemented lens formed by cementing a lens L5 and a lens L6. The lens component C6 is composed of a cemented lens formed by cementing a lens L7 and a lens L8. The lens component C7 is composed of a lens L9 that is a single lens. The lens component C8 is composed of a cemented lens formed by cementing a lens L10 and a lens L11. The lens component C9 is composed of a lens L12 that is a single lens. The lens component C10 is composed of a lens L13 that is a single lens.

[0212] The lens components C1 to C4 respectively correspond to the front-side lens components, and the lens components C7 to C10 respectively correspond to the rear-side lens components. A film 2 is provided on the edge surfaces of the lens components C1 to C6, C8 to C10. The focusing group is composed of the lens components C5 to C7 and the aperture stop St. When focusing from an infinitely distant object to a nearby object, the lens components constituting the focusing group move integrally toward the object side.

[0213] Regarding the optical system of Example 3, the basic lens data is shown in Table 11, the specifications are shown in Table 12, the aspherical coefficients are shown in Table 13, and the aberration diagrams in the state of focusing on an infinitely distant object are shown in Figure 11 . Moreover, regarding the front-side lens component and the rear-side lens component of the optical system of Example 3, the presence or absence of the film 2 on the edge surface, the corresponding values of the above conditional expressions (1) to (11), and ratios A to I are shown in Tables 14 and 15.

[0214] [Table 11]

[0215] Example 3

[0216]

[0217] [Table 12]

[0218] Example 3

[0219] f 30.91 Bf 26.52 FNo. 3.57 2ω[°] 84.4 Stφ 14.96 TL 117.47 TD 90.95

[0220] [Table 13]

[0221] Example 3

[0222] Sn 1 2 16 17 KA 1.0000000E+00 1.0000000E+00 1.0000000E+00 1.0000000E+00 A3 0.0000000E+00 0.0000000E+00 0.0000000E+00 0.0000000E+00 A4 1.7190323E-06 -1.0324755E-05 -3.6874743E-05 -1.7507432E-05 A5 -7.4474335E-07 -9.9518618E-07 1.5262016E-06 1.8963888E-06 A6 3.0051321E-08 -6.4950083E-09 2.2784479E-07 -1.6630172E-07 A7 8.1417469E-12 1.0528595E-09 -9.8209300E-08 -4.0718008E-08 A8 2.6419440E-11 -1.9802457E-10 4.2866430E-10 3.0729611E-09 A9 -8.4613032E-13 9.3801528E-12 1.4337539E-09 2.2019263E-10 A10 -6.7674963E-14 -2.6840622E-14 4.1053517E-11 -1.0135846E-11 A11 -5.2825214E-15 -9.6141003E-14 -1.4808362E-11 -1.3635971E-12 A12 1.3685955E-17 9.2320265E-15 -7.4799199E-13 3.6925212E-14 A13 -2.1817230E-17 -9.7218804E-16 9.9226988E-14 -2.6847120E-14 A14 1.9880799E-18 3.3672325E-17 2.1856025E-15 1.3212027E-15 A15 7.8661839E-20 4.2370872E-18 2.2178857E-16 1.8274698E-16 A16 9.0261546E-21 -9.1536371E-19 -2.2420853E-16 3.5944816E-17 A17 -5.4358767E-22 7.0329374E-20 3.2929455E-17 -3.1433068E-18 A18 -4.4806487E-23 -3.5736344E-22 2.2161945E-19 -6.0753510E-19 A19 2.0403062E-24 -1.5453784E-22 -2.7567893E-19 6.0854810E-20 A20 -5.5439226E-27 3.7714093E-24 1.1764954E-20 -9.4474266E-22

[0223] [Table 14]

[0224] Example 3

[0225] (1) FNo / tanω = 3.937

[0226]

[0227] [Table 15]

[0228] Example 3

[0229]

[0230] [Example 4]

[0231] A cross-sectional view of the structure of the optical system of Example 4 is shown in Figure 12 . The optical system of Example 4 includes, in order from the object side to the image side, lens components C1 to C4, an aperture stop St, and lens components C5 to C9. The lens component C1 is composed of a lens L1 which is a single lens. The lens component C2 is composed of a lens L2 which is a single lens. The lens component C3 is composed of a lens L3 which is a single lens. The lens component C4 is composed of a cemented lens formed by cementing a lens L4 and a lens L5. The lens component C5 is composed of a lens L6 which is a single lens. The lens component C6 is composed of a cemented lens formed by cementing a lens L7 and a lens L8. The lens component C7 is composed of a cemented lens formed by cementing a lens L9 and a lens L10. The lens component C8 is composed of a cemented lens formed by cementing a lens L11 and a lens L12. The lens component C9 is composed of a lens L13 which is a single lens.

[0232] The lens components C1 to C3 respectively correspond to the front lens components, and the lens components C7 to C9 respectively correspond to the rear lens components. Films 2 are provided on the edge surfaces of the lens components C1, C4, C6 to C9. The focusing group is composed of the lens components C3 to C7 and the aperture stop St. When focusing from an infinite object to a near object, the lens components constituting the focusing group move integrally toward the object side.

[0233] Regarding the optical system of Example 4, the basic lens data is shown in Table 16, the specifications are shown in Table 17, the aspherical coefficients are shown in Table 18, and the aberration diagrams in the state of focusing on an infinite object are shown in Figure 13Moreover, regarding the front lens component and the rear lens component of the optical system of Example 4, the film 2 with or without an edge surface, the corresponding values of the above conditional expressions (1) to (11), and Ratios A to I are shown in Tables 19 and 20.

[0234] [Table 16]

[0235] Example 4

[0236]

[0237] [Table 17] Example 4

[0238] f 56.67 Bf 20.50 FNo. 1.75 2ω[°] 52.0 Stφ 27.29 TL 122.24 TD 101.74

[0239] [Table 18]

[0240] Example 4

[0241] Sn 11 12 22 23 KA 1.0000000E+00 1.0000000E+00 1.0000000E+00 1.0000000E+00 A4 -2.0370108E-05 -1.4890456E-05 -2.5350781E-05 -2.0566239E-05 A6 -2.2837244E-08 -1.4092898E-08 5.0780164E-08 5.3699159E-08 A8 1.5881928E-10 1.4530204E-10 -5.4993528E-11 -5.6857976E-11 A10 -2.7238168E-13 -2.5033093E-13 4.3033371E-14 4.1725261E-14

[0242] [Table 19]

[0243] Example 4

[0244] (1) FNo / tanω = 3.588

[0245]

[0246] [Table 20]

[0247] Example 4

[0248]

[0249] [Example 5]

[0250] A cross-sectional view of the structure of the optical system of Example 5 is shown in Figure 14 . The optical system of Example 5 is a zoom lens. In Figure 14 , the wide-angle end state is shown in the upper part labeled "Wide", and the telephoto end state is shown in the lower part labeled "Tele". The optical system of Example 5 includes, in order from the object side to the image side, a first lens group G1 and a subsequent group GR. The subsequent group GR includes, in order from the object side to the image side, a second lens group G2, a third lens group G3, a fourth lens group G4, and a fifth lens group G5. During zooming, the second lens group G2 and the fourth lens group G4 move along the optical axis Z by changing the interval from the adjacent lens groups, and the first lens group G1, the third lens group G3, and the fifth lens group G5 are fixed relative to the image plane Sim. Between the upper and lower parts of Figure 14 , regarding the lens groups that move during zooming, the approximate movement locus from the wide-angle end to the telephoto end is indicated by an arrow, and regarding the lens groups that are fixed during zooming, a linear line segment in the vertical direction is indicated.

[0251] The first lens group G1 is composed of lens components C1 to C3 in order from the object side to the image side. The second lens group G2 is composed of lens components C4 to C7 in order from the object side to the image side. The third lens group G3 is composed of an aperture stop St and lens components C8 to C9 in order from the object side to the image side. The fourth lens group G4 is composed of a lens component C10. The fifth lens group G5 is composed of lens components C11 to C13 in order from the object side to the image side.

[0252] The lens component C1 is composed of a cemented lens formed by cementing a lens L1 and a lens L2. The lens component C2 is composed of a singlet lens L3. The lens component C3 is composed of a singlet lens L4. The lens component C4 is composed of a singlet lens L5. The lens component C5 is composed of a singlet lens L6. The lens component C6 is composed of a singlet lens L7. The lens component C7 is composed of a singlet lens L8. The lens component C8 is composed of a singlet lens L9. The lens component C9 is composed of a cemented lens formed by cementing a lens L10 and a lens L11. The lens component C10 is composed of a cemented lens formed by cementing a lens L12 and a lens L13. The lens component C11 is composed of a singlet lens L14. The lens component C12 is composed of a singlet lens L15. The lens component C13 is composed of a singlet lens L16.

[0253] In the wide-angle end state, the lens components C1 to C7 respectively correspond to the front-side lens components, and the lens components C11 to C13 respectively correspond to the rear-side lens components. In the telephoto end state, the lens components C1 to C3 respectively correspond to the front-side lens components, and the lens components C10 to C13 respectively correspond to the rear-side lens components. Films 2 are provided on the edge surfaces of the lens components C1, C4 to C5, C7, C9 to C10, C12 to C13. The focusing group is composed of the lens component C10. When focusing from an infinite object to a near object, the lens component constituting the focusing group moves integrally toward the image side. The right-facing arrow marked on the fourth lens group G4 in the figure in the lower paragraph indicates that the fourth lens group G4 moves toward the image side when focusing from an infinite object to a near object.

[0254] Regarding the optical system of Embodiment 5, the basic lens data is shown in Table 21, the specifications are shown in Table 22, the aspherical coefficients are shown in Table 23, and the aberration diagrams in the state of focusing on an infinite object are shown in Figure 15 .

[0255] In Table 21, regarding the variable surface interval during zooming, the notation DD[] is used, and the surface number on the object side of the interval is marked in [] and entered in the column of the surface interval. In the "Wide α-β" column, the value of αf-βf is shown for the front lens component at the wide-angle end, and the value of αr-βr is shown for the rear lens component. In the "Tele α-β" column, the value of αf-βf is shown for the front lens component at the telephoto end, and the value of αr-βr is shown for the rear lens component. In Table 21, the descriptions of "fC" and "rC" are omitted.

[0256] Table 22 shows the specifications and variable surface intervals of the optical system of Example 5. In Table 22, the respective values in the state of the wide-angle end are shown in the column marked "Wide", and the respective values in the state of the telephoto end are shown in the column marked "Tele". The zoom ratio Zr is also shown in Table 22. Figure 15 shows the respective aberration diagrams in the state where the optical system of Example 5 is focused on an object at infinity. In Figure 15 it, the aberration in the state of the wide-angle end is shown in the upper part marked "Wide", and the aberration in the state of the telephoto end is shown in the lower part marked "Tele".

[0257] [Table 21]

[0258] Example 5

[0259]

[0260]

[0261] [Table 22] Example 5

[0262] Wide Tele Zr 1.0 6.3 f 18.54 116.77 Bf 22.66 22.66 FNo. 4.09 4.12 2ω[°] 77.8 12.8 Stφ 14.33 16.51 TL 144.32 144.32 TD 121.66 121.66 DD[7] 1.01 31.03 DD

[15] 31.02 1.00 DD

[21] 1.04 12.53 DD

[24] 21.80 10.31

[0263] [Table 23]

[0264] Example 5

[0265]

[0266] Regarding the front lens component and the rear lens component of the optical system of Example 5, the presence or absence of the film 2 on the edge surface, the corresponding values of the above conditional expressions (1) to (11), and the ratios A to I are shown in Tables 24 to 27. The states in the wide-angle end state are shown in Tables 24 and 25. The states in the telephoto end state are shown in Tables 26 and 27.

[0267] [Table 24]

[0268] Example 5 Wide

[0269] (1) FNo / tanω = 5.069

[0270]

[0271] [Table 25]

[0272] Example 5 Wide

[0273]

[0274] [Table 26] Example 5 Tele

[0275]

[0276] [Table 27]

[0277] Example 5 Tele

[0278]

[0279] As described above, the technology of the present invention has been described by way of embodiments and examples. However, the technology of the present invention is not limited to the above-described embodiments and examples, and various modifications can be made. For example, the number of lens elements constituting the optical system, the number of lens components, and the number of lens groups are not limited to the above examples. The variable magnification optical system is not limited to a zoom lens, and may also be a variable focal length lens. The curvature radius, surface interval, refractive index, Abbe number, aspherical coefficient, etc. of each lens are not limited to the values shown in the above respective examples, and other values can be adopted.

[0280] Furthermore, the use of the optical system of the present invention is not limited to digital cameras. The optical system of the present invention can be applied to various devices such as film cameras, video cameras, terminal cameras, movie cameras, and surveillance cameras, for example.

[0281] Regarding the above-described embodiments and examples, the following supplementary items are further disclosed.

[0282] [Supplementary Item 1]

[0283] An optical system, wherein when one lens component is a single lens or a cemented lens, it includes at least one lens component, and in the optical system,

[0284] The outer peripheral surface parallel to the optical axis of the lens component is defined as the edge surface,

[0285] The distance on the optical axis from the lens surface closest to the object side of the optical system to the lens surface closest to the image side of the optical system is defined as TD,

[0286] When at least a part of the lens components included in the optical system is a front-side lens component located within a range from the object-side lens surface closest to the object in the optical system to 0.3×TD on the image side along the optical axis,

[0287] A film with a light reflectance of less than 30% is provided at 50% or more of the total area of the edge surfaces of all the front-side lens components.

[0288] [Supplementary Note 2]

[0289] In the optical system according to Supplementary Note 1, wherein

[0290] Let the open F-number of the optical system in a state focused on an infinitely distant object be FNo,

[0291] Let the maximum half-angle of view of the optical system in a state focused on an infinitely distant object be ω,

[0292] When FNo and ω are values at the wide-angle end in the case where the optical system is a zoom optical system, the following is satisfied

[0293] 1 < FNo / tanω < 10 (1)

[0294] The conditional expression (1) represented.

[0295] [Supplementary Note 3]

[0296] In the optical system according to Supplementary Note 1 or Supplementary Note 2, wherein

[0297] Let the intersection point of the object-side lens surface closest to the object in the optical system and the optical axis be the front-side intersection point,

[0298] For each of the front-side lens components, let the angle formed by the line connecting the front-side intersection point and the object-side point closest to the edge surface with the optical axis be αf, and the angle formed by the line connecting the front-side intersection point and the image-side point closest to the edge surface with the optical axis be βf. When the units of αf and βf are degrees, when the following is satisfied

[0299] 2.7° < αf - βf < 40° (2)

[0300] The film is provided at 50% or more of the total area of the edge surfaces of all the front-side lens components that satisfy the conditional expression (2) represented.

[0301] [Supplementary Note 4]

[0302] In the optical system according to any one of Supplementary Notes 1 to 3, wherein

[0303] Let the intersection point of the lens surface closest to the object side of the optical system and the optical axis be the front-side intersection point.

[0304] Let N be a natural number of 2 or more.

[0305] For the Nth front-side lens component from the object side, let the angle formed by the line connecting the front-side intersection point and the point on the edge surface closest to the object side and the optical axis be αf, and let the angle formed by the line connecting the front-side intersection point and the point on the edge surface closest to the image side and the optical axis be βf. Let the unit of αf and βf be degrees. When the combined focal length from the front-side lens component closest to the object side to the (N - 1)th front-side lens component from the object side is ff, when satisfying

[0306] 1.1° < αf - βf ≤ 2.7° (3) and

[0307] -2.4 < TD / ff (4)

[0308] The proportion of the area where the film is provided in the total area of the edge surfaces of all the front-side lens components that satisfy the conditional expressions (3) and (4) represented is 30% or less.

[0309] [Supplementary Note 5]

[0310] According to the optical system described in any one of Supplementary Notes 1 to 4, wherein,

[0311] Let the intersection point of the lens surface closest to the object side of the optical system and the optical axis be the front-side intersection point.

[0312] Let N be a natural number of 2 or more.

[0313] For the Nth front-side lens component from the object side, let the angle formed by the line connecting the front-side intersection point and the point on the edge surface closest to the object side and the optical axis be αf, and let the angle formed by the line connecting the front-side intersection point and the point on the edge surface closest to the image side and the optical axis be βf. Let the unit of αf and βf be degrees. When the paraxial curvature radius of the surface closest to the image side of the Nth front-side lens component from the object side is Rf, when satisfying

[0314] 1.1° < αf - βf ≤ 2.7° (3) and

[0315] TD / Rf < 2.4 (5)

[0316] The proportion of the area where the film is provided in the total area of the edge surfaces of all the front-side lens components that satisfy the conditional expressions (3) and (5) represented is 30% or less.

[0317] [Supplementary Note 6]

[0318] The optical system according to any one of appended item 1 to appended item 5, wherein

[0319] The intersection of the lens surface closest to the object side of the optical system and the optical axis is defined as the front-side intersection point,

[0320] For each of the front-side lens components, the angle formed by the line connecting the front-side intersection point and the point on the object-side closest to the edge surface with respect to the optical axis is defined as αf, and the angle formed by the line connecting the front-side intersection point and the point on the image-side closest to the edge surface with respect to the optical axis is defined as βf. When the units of αf and βf are degrees,

[0321] Among the lens components included in the optical system, the lens components in which at least a part of the lens components is located within the range from the lens surface closest to the image side of the optical system to the object side by 0.3 × TD on the optical axis are defined as the rear-side lens components,

[0322] The intersection of the lens surface closest to the image side of the optical system and the optical axis is defined as the rear-side intersection point,

[0323] For each of the rear-side lens components, when the angle formed by the line connecting the rear-side intersection point and the point on the image-side closest to the edge surface with respect to the optical axis is defined as αr, and the angle formed by the line connecting the rear-side intersection point and the point on the object-side closest to the edge surface with respect to the optical axis is defined as βr, and the units of αr and βr are degrees, when satisfying

[0324] 0° < αf - βf ≤ 1.1° (10)

[0325] For all the edge surfaces of the front-side lens components that satisfy the conditional expression (10) represented by

[0326] 0° < αr - βr ≤ 1.1° (11)

[0327] The proportion of the area where the film is provided in the total area of all the edge surfaces of the rear-side lens components that satisfy the conditional expression (11) is 30% or less.

[0328] [Appended item 7]

[0329] An optical system, wherein when one lens component is set as one single lens or one cemented lens, it includes at least one lens component. In the optical system,

[0330] The outer peripheral surface parallel to the optical axis of the lens component is defined as the edge surface,

[0331] The distance on the optical axis from the lens surface closest to the object side of the optical system to the lens surface closest to the image side of the optical system is defined as TD,

[0332] When at least a part of the lens components included in the optical system is a rear lens component within a range from the image-side most lens surface of the optical system toward the object side along the optical axis to 0.3×TD,

[0333] a film having a light reflectance of less than 30% is provided at 50% or more of the total area of the edge surfaces of all the rear lens components.

[0334] [Supplementary Note Item 8]

[0335] In the optical system according to Supplementary Note Item 7, wherein,

[0336] Let the intersection of the image-side most lens surface of the optical system and the optical axis be the rear intersection point,

[0337] For each of the rear lens components, when the angle formed by the line connecting the rear intersection point and the image-side most point of the edge surface with the optical axis is αr, and the angle formed by the line connecting the rear intersection point and the object-side most point of the edge surface with the optical axis is βr, and the unit of αr and βr is degrees, when satisfying

[0338] 2.7° < αr - βr < 40° (6)

[0339] the film is provided at 50% or more of the total area of the edge surfaces of all the rear lens components that satisfy the conditional expression (6).

[0340] [Supplementary Note Item 9]

[0341] In the optical system according to Supplementary Note Item 7 or Supplementary Note Item 8, wherein,

[0342] Let the intersection of the image-side most lens surface of the optical system and the optical axis be the rear intersection point,

[0343] Let M be a natural number of 2 or more,

[0344] For the M-th rear lens component from the image side, when the angle formed by the line connecting the rear intersection point and the image-side most point of the edge surface with the optical axis is αr, and the angle formed by the line connecting the rear intersection point and the object-side most point of the edge surface with the optical axis is βr, and the unit of αr and βr is degrees, and when the combined focal length from the image-side most rear lens component to the (M - 1)-th rear lens component from the image side is fr, when satisfying

[0345] 1.1° < αr - βr ≤ 2.7° (7) and

[0346] -2.4 < TD / fr (8)

[0347] The ratio of the area where the film is provided to the total area of the marginal surfaces of all the rear lens components represented by the conditional expressions (7) and (8) is 30% or less.

[0348] [Supplementary Note Item 10]

[0349] For the optical system according to any one of Supplementary Note Items 7 to 9, wherein

[0350] Let the intersection point of the lens surface closest to the image side of the optical system and the optical axis be the rear intersection point,

[0351] Let M be a natural number of 2 or more,

[0352] For the M-th rear lens component from the image side, let the angle formed by the line connecting the rear intersection point and the point on the marginal surface closest to the image side with the optical axis be αr, and let the angle formed by the line connecting the rear intersection point and the point on the marginal surface closest to the object side with the optical axis be βr. Let the unit of αr and βr be degrees, and let the paraxial curvature radius of the surface closest to the object side of the M-th rear lens component from the image side be Rr. In the case of satisfying

[0353] 1.1° < αr - βr ≤ 2.7° (7) and

[0354] -10 < TD / Rr (9)

[0355] The ratio of the area where the film is provided to the total area of the marginal surfaces of all the rear lens components represented by the conditional expressions (7) and (9) is 30% or less.

[0356] [Supplementary Note Item 11]

[0357] For the optical system according to any one of Supplementary Note Items 7 to 10, wherein

[0358] Let the lens components in the lens components included in the optical system, at least a part of which is located in the range from the lens surface closest to the object side of the optical system to 0.3 × TD toward the image side on the optical axis, be the front lens components,

[0359] Let the intersection point of the lens surface closest to the object side of the optical system and the optical axis be the front intersection point,

[0360] For each of the front lens components, the angle formed by the line connecting the front intersection point and the object-side closest point on the edge surface with the optical axis is defined as αf, and the angle formed by the line connecting the front intersection point and the image-side closest point on the edge surface with the optical axis is defined as βf. When the units of αf and βf are degrees,

[0361] The intersection point of the image-side closest lens surface of the optical system with the optical axis is defined as the rear intersection point.

[0362] For each of the rear lens components, when the angle formed by the line connecting the rear intersection point and the image-side closest point on the edge surface with the optical axis is defined as αr, and the angle formed by the line connecting the rear intersection point and the object-side closest point on the edge surface with the optical axis is defined as βr, and the units of αr and βr are degrees, when satisfying

[0363] 0° < αf - βf ≤ 1.1° (10)

[0364] For all the edge surfaces of the front lens components that satisfy the conditional expression (10) represented by

[0365] 0° < αr - βr ≤ 1.1° (11)

[0366] The proportion of the area where the film is provided in the total area of all the edge surfaces of the rear lens components is 30% or less.

[0367] [Supplementary Note Item 12]

[0368] According to the optical system described in any one of Supplementary Note Items 1 to 11, wherein

[0369] The optical system sequentially includes a first lens group having a positive refractive power and a subsequent group including at least one lens group from the object side to the image side.

[0370] During zooming, the interval between adjacent lens groups changes.

[0371] [Supplementary Note Item 13]

[0372] According to the optical system described in Supplementary Note Item 12, wherein the subsequent group includes a second lens group having a negative refractive power on the object-side closest side.

[0373] [Supplementary Note Item 14]

[0374] According to the optical system described in Supplementary Note Item 12 or Supplementary Note Item 13, wherein

[0375] The subsequent group sequentially and continuously includes a second lens group, a third lens group, and a fourth lens group from the object side to the image side.

[0376] During zooming, at least the second lens group and the fourth lens group move.

[0377] [Supplementary Note Item 15]

[0378] The optical system according to any one of Supplementary Note Items 12 to 14, wherein

[0379] The subsequent group includes a focusing group that moves along the optical axis during focusing.

[0380] All documents, patent applications, and technical standards described in this specification are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually described as being incorporated by reference.

Claims

1. An optical system, wherein, When one lens component is a single lens or a cemented lens, the optical system includes at least one lens component. The outer peripheral surface parallel to the optical axis of the lens component is defined as the edge surface. The distance on the optical axis from the lens surface closest to the object side of the optical system to the lens surface closest to the image side of the optical system is defined as TD. When, among the lens components included in the optical system, at least a part of the lens component is located within the range from the lens surface closest to the object side of the optical system to 0.3×TD toward the image side on the optical axis, and the lens component is defined as the front-side lens component. A film with a light reflectivity of less than 30% is provided at 50% or more of the total area of the edge surfaces of all the front-side lens components.

2. The optical system according to claim 1, wherein The open F-number of the optical system in the state of focusing on an infinitely distant object is defined as FNo. The maximum half-angle of view of the optical system in the state of focusing on an infinitely distant object is defined as ω. When the optical system is a zoom optical system and FNo and ω are the values at the wide-angle end, the following is satisfied: 1 < FNo / tanω < 10 (1) The conditional expression (1) represented by the above formula is satisfied.

3. The optical system according to claim 1, wherein The intersection point of the lens surface closest to the object side of the optical system and the optical axis is defined as the front-side intersection point. For each of the front-side lens components, the angle formed by the line connecting the front-side intersection point and the point on the edge surface closest to the object side with the optical axis is defined as αf, and the angle formed by the line connecting the front-side intersection point and the point on the edge surface closest to the image side with the optical axis is defined as βf. When the units of αf and βf are degrees, the film is provided at 50% or more of the total area of the edge surfaces of all the front-side lens components that satisfy the following: 2.7° < αf - βf < 40° (2) The conditional expression (2) represented by the above formula is satisfied.

4. The optical system according to claim 1, wherein The intersection point of the lens surface closest to the object side of the optical system and the optical axis is defined as the front-side intersection point. N is a natural number of 2 or more. For the Nth front-side lens component from the object side, the angle formed by the line connecting the front-side intersection point and the point on the edge surface closest to the object side with the optical axis is defined as αf, and the angle formed by the line connecting the front-side intersection point and the point on the edge surface closest to the image side with the optical axis is defined as βf. When the units of αf and βf are degrees and the combined focal length from the front-side lens component closest to the object side to the (N - 1)th front-side lens component from the object side is defined as ff, the proportion of the area where the film is provided in the total area of the edge surfaces of all the front-side lens components that satisfy the following: 1.1° < αf - βf ≤ 2.7° (3) and -2.4 < TD / ff (4) The conditional expressions (3) and (4) represented by the above formulas is 30% or less.

5. The optical system according to claim 1, wherein The intersection point of the lens surface closest to the object side of the optical system and the optical axis is defined as the front-side intersection point. Let N be a natural number of 2 or more. For the N-th front lens component from the object side, let the angle formed by the line connecting the front intersection point and the point on the object-side most edge surface with the optical axis be αf, and the angle formed by the line connecting the front intersection point and the point on the image-side most edge surface with the optical axis be βf. When the unit of αf and βf is degree and the paraxial curvature radius of the image-side most surface of the N-th front lens component from the object side is Rf, when satisfying 1.1° < αf - βf ≤ 2.7° (3) and TD / Rf < 2.4 (5) The proportion of the area where the film is provided in the total area of the edge surfaces of all the front lens components that satisfy the conditional expressions (3) and (5) represented is 30% or less.

6. The optical system according to claim 1, wherein The intersection point of the object-side most lens surface of the optical system and the optical axis is set as the front intersection point. For each of the front lens components, let the angle formed by the line connecting the front intersection point and the point on the object-side most edge surface with the optical axis be αf, and the angle formed by the line connecting the front intersection point and the point on the image-side most edge surface with the optical axis be βf. When the unit of αf and βf is degree, Among the lens components included in the optical system, the lens components in which at least a part of the lens components is located in the range from the image-side most lens surface of the optical system to the object side by 0.3 × TD on the optical axis are set as the rear lens components. The intersection point of the image-side most lens surface of the optical system and the optical axis is set as the rear intersection point. For each of the rear lens components, when the angle formed by the line connecting the rear intersection point and the point on the image-side most edge surface with the optical axis is αr, and the angle formed by the line connecting the rear intersection point and the point on the object-side most edge surface with the optical axis is βr, when the unit of αr and βr is degree, when satisfying 0° < αf - βf ≤ 1.1° (10) The proportion of the area where the film is provided in the total area of the edge surfaces of all the front lens components that satisfy the conditional expression (10) and 0°＜αr-βr≤1.1°(11) The proportion of the area where the film is provided in the total area of the edge surfaces of all the rear lens components that satisfy the conditional expression (11) represented is 30% or less.

7. An optical system, wherein, When one lens component is a single lens or a cemented lens, including at least one lens component, in the optical system, The outer peripheral surface parallel to the optical axis of the lens component is set as the edge surface. The distance on the optical axis from the object-side most lens surface of the optical system to the image-side most lens surface of the optical system is set as TD. When among the lens components included in the optical system, the lens components in which at least a part of the lens components is located in the range from the image-side most lens surface of the optical system to the object side by 0.3 × TD on the optical axis are set as the rear lens components, A film with a light reflectivity of less than 30% is provided at 50% or more of the total area of the edge surfaces of all the rear lens components.

8. The optical system according to claim 7, wherein the intersection of the lens surface closest to the image side of the optical system and the optical axis is defined as the rear intersection point, for each of the rear lens components, the angle formed by the line connecting the rear intersection point and the point on the image-side edge surface closest to the image side with the optical axis is defined as αr, and the angle formed by the line connecting the rear intersection point and the point on the object-side edge surface closest to the object side with the optical axis is defined as βr. When the units of αr and βr are degrees, the film is provided at 50% or more of the total area of the edge surfaces of all the rear lens components that satisfy 2.7°＜αr-βr＜40° (6) the conditional expression (6) represented.

9. The optical system according to claim 7, wherein the intersection of the lens surface closest to the image side of the optical system and the optical axis is defined as the rear intersection point, M is defined as a natural number of 2 or more, for the M-th rear lens component from the image side, the angle formed by the line connecting the rear intersection point and the point on the image-side edge surface closest to the image side with the optical axis is defined as αr, and the angle formed by the line connecting the rear intersection point and the point on the object-side edge surface closest to the object side with the optical axis is defined as βr. When the units of αr and βr are degrees and the combined focal length from the rear lens component closest to the image side to the (M - 1)-th rear lens component from the image side is defined as fr, the proportion of the area where the film is provided in the total area of the edge surfaces of all the rear lens components that satisfy 1.1° < αr - βr ≤ 2.7° (7) and -2.4 < TD / fr (8) represented by the conditional expressions (7) and (8) is 30% or less.

10. The optical system according to claim 7, wherein the intersection of the lens surface closest to the image side of the optical system and the optical axis is defined as the rear intersection point, M is defined as a natural number of 2 or more, for the M-th rear lens component from the image side, the angle formed by the line connecting the rear intersection point and the point on the image-side edge surface closest to the image side with the optical axis is defined as αr, and the angle formed by the line connecting the rear intersection point and the point on the object-side edge surface closest to the object side with the optical axis is defined as βr. When the units of αr and βr are degrees and the paraxial curvature radius of the object-side surface of the M-th rear lens component from the image side is defined as Rr, the proportion of the area where the film is provided in the total area of the edge surfaces of all the rear lens components that satisfy 1.1° < αr - βr ≤ 2.7° (7) and -10 < TD / Rr (9) represented by the conditional expressions (7) and (9) is 30% or less.

11. The optical system according to claim 7, wherein among the lens components included in the optical system, the lens components at least a part of which is located within the range from the lens surface closest to the object side of the optical system to 0.3 × TD on the image side along the optical axis are defined as the front lens components, the intersection of the lens surface closest to the object side of the optical system and the optical axis is defined as the front intersection point, For each of the front lens components, the angle formed by the line connecting the front intersection point and the point on the object-side closest to the edge surface with respect to the optical axis is defined as αf, and the angle formed by the line connecting the front intersection point and the point on the image-side closest to the edge surface with respect to the optical axis is defined as βf. The units of αf and βf are degrees. The intersection point of the lens surface closest to the image side of the optical system and the optical axis is defined as the rear intersection point. For each of the rear lens components, when the angle formed by the line connecting the rear intersection point and the point on the image-side closest to the edge surface with respect to the optical axis is defined as αr, and the angle formed by the line connecting the rear intersection point and the point on the object-side closest to the edge surface with respect to the optical axis is defined as βr, and the units of αr and βr are degrees, under the condition that 0° < αf - βf ≤ 1.1° (10) is satisfied for all the edge surfaces of the front lens components, and the proportion of the area of the film provided in the total area of all the edge surfaces of the rear lens components that satisfy 0°＜αr-βr≤1.1° (11) is 30% or less.

12. The optical system according to any one of claims 1 to 11, wherein the optical system sequentially includes a first lens group having a positive refractive power and a subsequent group including at least one lens group from the object side to the image side. During zooming, the interval between adjacent lens groups changes.

13. The optical system according to claim 12, wherein the subsequent group includes a second lens group having a negative refractive power on the object-side closest.

14. The optical system according to claim 13, wherein the subsequent group sequentially and continuously includes the second lens group, the third lens group, and the fourth lens group from the object side to the image side. During zooming, at least the second lens group and the fourth lens group move.

15. The optical system according to claim 14, wherein the subsequent group includes a focusing group that moves along the optical axis during focusing.

Images