Lens device and imaging apparatus having same

Abstract

This lens device comprises, disposed in order from the object side to the image side, a first lens group having negative refractive power and a rear group including one or more lens groups, wherein: during zooming, a lens G1 disposed closest to the object side among lenses included in the first lens group is immobile with respect to an image plane; during zooming, the distance between adjacent lens groups changes; and when the half angle of view during focusing at infinity at a wide-angle end is denoted by ωw (°), a conditional expression of ωw > 85 is satisfied. The lens device is characterized by comprising a first lens barrel, a light-blocking member disposed closer to the object side than the first lens barrel, and a cylindrical member located on the outer diameter side of the light-blocking member, and by being provided with a cover member between the light-blocking member and the cylindrical member and / or between the first lens barrel and the cylindrical member.

Description

Lens device and imaging device having the same

[0001] The disclosure of this specification relates to a lens device and an imaging device having the same, and is suitable for imaging devices such as digital still cameras, video cameras, broadcast cameras, surveillance cameras, and vehicle-mounted cameras that use solid-state imaging elements, or cameras that use silver halide photographic film.

[0002] Lens devices used in imaging devices are required to have good optical characteristics while providing a wide angle of view. As a wide-angle lens device, a negative lead lens device in which a lens group having negative refractive power is arranged closest to the object, as disclosed in Patent Document 1, is known.

[0003] Japanese Patent Application Laid-Open No. 2020-166234

[0004] In a wide-angle lens device such as that disclosed in Patent Document 1, the performance of the lens device can be improved by providing it with drip-proof and dust-proof capabilities to prevent the intrusion of foreign matter such as water droplets, dust, and sand. For this reason, it is necessary to provide cover members necessary for drip-proofing and dust-proofing in appropriate positions on the lens device.

[0005] According to one aspect of the present invention, there is provided a lens device comprising, arranged in order from the object side to the image side, a first lens group having negative refractive power and a rear group including one or more lens groups, wherein, during zooming, the lens G1 of the first lens group located closest to the object remains stationary relative to the image plane, the spacing between adjacent lens groups changes during zooming, and the lens device satisfies the condition ωw > 85, where ωw (°) is the half angle of view when focusing on infinity at the wide-angle end, the lens device comprises a first lens barrel, a light-shielding member located closer to the object than the first lens barrel, and a cylindrical member located on the outer diameter side of the light-shielding member, and a cover member is provided between at least one of the light-shielding member and the cylindrical member or the first lens barrel and the cylindrical member. An imaging device including the lens device also constitutes another aspect of the present invention.

[0006] It is possible to provide a lens device with excellent drip-proof and dust-proof properties and a wide angle of view.

[0007] Cross-sectional view of the lens device of Example 1Aberration diagram of the lens device of Example 1Aberration diagram of the lens device of Example 1Aberration diagram of the lens device of Example 1Cross-sectional view of the lens device of Example 2Aberration diagram of the lens device of Example 2Aberration diagram of the lens device of Example 2Aberration diagram of the lens device of Example 2Cross-sectional view of the lens device of Example 3Aberration diagram of the lens device of Example 3Aberration diagram of the lens device of Example 3Aberration diagram of the lens device of Example 3Cross-sectional view of the lens device of Example 4Aberration diagram of the lens device of Example 4Aberration diagram of the lens device of Example 4Cross-sectional view of the lens device of Example 5Aberration diagram of the lens device of Example 5Aberration diagram of the lens device of Example 5Aberration diagram of the lens device of Example 6 aberration diagram of the lens device of Example 6 aberration diagram of the lens device of Example 6 schematic diagram of an imaging device cross-sectional view showing the lens barrel of the embodiment diagram showing the shape of the rear fixed barrel into which the filter barrel is incorporated enlarged cross-sectional view showing a drip-proof configuration arranged in the optical axis direction on the inner diameter side around the lens G1 enlarged cross-sectional view showing a drip-proof configuration arranged in the radial direction on the outer diameter side around the lens G1 enlarged cross-sectional view showing a drip-proof configuration arranged in the radial direction on the inner diameter side around the lens G1 enlarged cross-sectional view showing a drip-proof configuration arranged in the optical axis direction on the outer diameter side around the lens G1 enlarged cross-sectional view showing a drip-proof configuration arranged in the optical axis direction on the inner diameter side around the lens G1 enlarged cross-sectional view showing a drip-proof configuration arranged in the optical axis direction on the outer diameter side around the lens G1

[0008] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the drawings. Note that the drawings may be drawn at a scale different from the actual scale for convenience. In addition, the same reference numerals are used for the same components in the drawings, and duplicate descriptions will be omitted.

[0009] 1, 3, 5, 7, 9, and 11 are cross-sectional views of the lens apparatus L0 of Examples 1 to 6 at the wide-angle end when focused on infinity. The lens apparatus L0 of each Example is used in imaging devices such as digital video cameras, digital still cameras, broadcast cameras, silver halide film cameras, and surveillance cameras, as well as optical equipment including interchangeable lenses. In each cross-sectional view, the left side is the object side, and the right side is the image side.

[0010] The lens device L0 in each embodiment is composed of multiple lens groups. Note that a lens group in this specification refers to a group of one or more lenses that move together during zooming. In the lens device L0 in each embodiment, the spacing between adjacent lens groups changes during zooming from the wide-angle end to the telephoto end. Each lens group may also include an aperture stop.

[0011] In each cross-sectional view, Li denotes the i-th lens group (i is a natural number) counting from the object side among the lens groups included in the lens device L0, and LR denotes the rear group, which includes all lenses and lens groups arranged closer to the image side than the first lens group L1.

[0012] In each cross-sectional view, SP denotes an aperture stop. In each cross-sectional view, IP denotes an image plane, and when the lens apparatus L0 of each embodiment is used as the photographic optical system of a digital still camera or digital video camera, the imaging surface of a solid-state image sensor such as a CCD sensor or a photoelectric conversion element such as a CMOS sensor is disposed thereon. Furthermore, when the lens apparatus L0 of each embodiment is used as the photographic optical system of a silver halide film camera, a photosensitive surface corresponding to the film surface is disposed at the image plane IP.

[0013] The solid arrows in each lens cross-sectional view are simplified representations of the movement locus of each lens group during zooming from the wide-angle end to the telephoto end. In this specification, the wide-angle end and the telephoto end refer to the zoom positions when each lens group is located at either end of the range of movement along the optical axis. The dashed arrows in each lens cross-sectional view are simplified representations of the movement locus of the focus group LF that moves relative to the image plane during focusing from infinity to a close distance.

[0014] The lens device L0 in each embodiment comprises, arranged in order from the object side to the image side, a first lens unit L1 having negative refractive power and a rear lens unit LR including one or more lens units. The rear lens unit LR includes all lens units arranged closer to the image side than the first lens unit L1. Note that in the lens device L0 in each embodiment, an optical element with substantially no refractive power, such as a low-pass filter or an infrared cut filter, may be arranged between the lens arranged closest to the image side and the imaging surface.

[0015] 2A to 2C, 4A to 4C, 6A to 6C, 8A to 8C, 10A to 10C, and 12A to 12C are aberration diagrams of the lens device L0 of Examples 1 to 6. Each aberration diagram shows the aberration of each Example when focused at infinity, with Figures 2A, 4A, 6A, 8A, 10A, and 12A being aberration diagrams at the wide-angle end, Figures 2B, 4B, 6B, 8B, 10B, and 12B being aberration diagrams at intermediate zoom positions, and Figures 2C, 4C, 6C, 8C, 10C, and 12C being aberration diagrams at the telephoto end.

[0016] In the spherical aberration diagrams, Fno is the F-number, and the solid line indicates the amount of spherical aberration for the d-line (wavelength 587.6 nm) and the two-dot dashed line indicates the amount of spherical aberration for the g-line (wavelength 435.8 nm). In the astigmatism diagrams, ΔS indicates the amount of astigmatism on the sagittal image plane, and ΔM indicates the amount of astigmatism on the meridional image plane. In the distortion diagrams, the solid line indicates the amount of distortion for the d-line. In the chromatic aberration diagrams, the two-dot dashed line indicates the amount of chromatic aberration at the g-line. In addition, in each aberration diagram, ω is the imaging half angle of view (°), which is the angle of view calculated by paraxial calculation.

[0017] In the lens device L0 of each embodiment, the projection method of Examples 1 to 3 is the conformal projection method represented by the formula Y = f θ. Furthermore, the projection method of Examples 4 to 6 is the equisolid angle projection method represented by the formula Y = 2 f sin(θ / 2). Note that in the lens device of each embodiment, the projection method is not limited to conformal projection or equisolid angle projection, and other projection methods may be used.

[0018] FIG. 14 is a cross-sectional view showing a lens barrel according to this embodiment. The line X-X in the figure represents the optical axis. In FIG. 14, a mount 101 is a component fixed to a camera body (not shown). A guide barrel 102 is fixed integrally to the mount 101 along with a rear fixed barrel 131 and an intermediate fixed barrel 132. A cam ring 104 is held on the outer periphery of the guide barrel 102 so as to be rotatable around the optical axis. The cam ring 104 is connected to a zoom ring 105, which is held rotatably on the outer periphery of the intermediate fixed barrel 132, by a key member (not shown), and is configured to rotate integrally with the zoom ring 105 by operating the zoom ring 105 from the outside.

[0019] The zoom sensor 106 is attached to the intermediate fixed barrel 132 and is a sensor that can electrically detect the rotation angle of the zoom ring 105. The zoom sensor 106 is electrically connected to a control board 107 and transmits focal length information during zooming to a control circuit.

[0020] The control board 107 is electrically connected to a contact block 108, and performs communication with the camera body (not shown) and power supply.

[0021] The first lens group L1 is held by a first group barrel 111, and the first group barrel 111 is in contact with a guide barrel .

[0022] The second lens group L2 is held by the second group barrel 112 and abuts against the second group base barrel 119.

[0023] The third lens group L3 is held by a third group barrel 113 and abuts against a rear group base barrel 120.

[0024] The fourth lens group L4 is held by a fourth group barrel 114 and abuts against a rear group base barrel 120.

[0025] The rear group base barrel 120 holds an electromagnetic diaphragm unit 121 and is electrically connected to the control board 107 .

[0026] The fifth lens group L5 is held in a fifth-group barrel 115, which is held by a guide bar (not shown) so as to be movable in the optical axis direction relative to the rear-group base barrel 120. The fifth lens group L5 is a lens used for focus adjustment, and is driven in the optical axis direction via a rack 123 by a stepping motor 122 connected to a lead screw held in the rear-group base barrel 120. The stepping motor 122 is electrically connected to the control board 107 by a flexible printed circuit board (not shown).

[0027] The second-group barrel 119 and the rear-group base barrel 120 are each barrels that move during zooming, and cam followers (not shown) are fixed to the second-group barrel 119 and the rear-group base barrel 120. Each cam follower is engaged with a linear groove provided in the guide barrel 102 and a cam groove provided in the cam ring 104, and is configured to be able to move linearly in the optical axis direction by rotating the cam ring 104.

[0028] Furthermore, the fifth group barrel 115 for focus adjustment is held by the rear group base barrel 120, and is therefore driven in the optical axis direction by a stepping motor 122 while moving together with the rear group base barrel 120 during zooming.

[0029] The filter 110 is held by a filter barrel 117 and is incorporated between the sixth group barrel 116 and the mount 101. As shown in Figure 15, an opening H is provided in the rear fixed barrel 131, allowing the filter barrel 117 to be incorporated.

[0030] Next, the characteristic configuration of the lens device L0 of each embodiment will be described.

[0031] The lens device L0 in each embodiment is a negative-lead type lens device in which the first lens unit L1 has negative refractive power. Of the lenses included in the first lens unit L1, the lens G1 closest to the object is fixed relative to the image plane during zooming. This prevents the overall optical length of the lens device L0 from changing during zooming, improving the robustness of the lens device L0.

[0032] When the half angle of view of the lens device L0 at the wide-angle end when focused at infinity is ωw (°), the wide angle of view required for a fisheye lens device or an ultra-wide-angle lens device can be obtained by satisfying the condition ωw > 85. Furthermore, in order to obtain a sufficiently wide angle of view for a fisheye lens device or an ultra-wide-angle lens device, it is more preferable to satisfy ωw > 90 or ωw > 94.

[0033] Furthermore, as shown in FIG. 14, the lens device L0 of each embodiment includes a first lens barrel 111 that holds the lens G1, a light-shielding member 134 that is positioned closer to the object than the first lens barrel, and a cylindrical member 135 that is positioned on the outer diameter side of the light-shielding member 134.

[0034] As described above, the first lens barrel 111 is in contact with the guide barrel 102 and holds the first lens group L1. The light blocking member 134 prevents unnecessary light from entering the lens device L0 from the outside.

[0035] In addition, in the lens device L0 of each embodiment, a cover member for preventing drips and dust is provided at least either between the light-shielding member 134 and the cylindrical member 135 or between the first lens barrel 111 and the cylindrical member 135.

[0036] Here, the cover member in this embodiment will be described with reference to FIG.

[0037] FIG. 16 is an enlarged view of the rectangular dashed line portion in FIG. 14, and shows only the components of the lens device L0 of this embodiment that are related to the drip-proof configuration.

[0038] 16 , in the lens device L0 of each embodiment, the lens G1 (133) arranged closest to the object side of the lens device L0 is held by the first-group barrel 111 and a light-blocking member 134. The light-blocking member 134 abuts against the first-group barrel 111 and also against the object-side lens surface of the lens G1 (133), thereby holding the lens G1 (133). A cylindrical member 135 is arranged on the outer diameter side of the light-blocking member 134, and the cylindrical member 135 is an external component of the lens device L0.

[0039] Furthermore, in the lens device L0 of each embodiment, a cover member 136 is disposed at least either between the barrel member 135 and the first barrel 111 or between the barrel member 135 and the light blocking member 136. In Fig. 16, the cover member 136 is disposed between the barrel member 135 and the first barrel 111. The cover member 136 is joined to the first barrel 111 or the barrel member 135 by, for example, applying an adhesive such as double-sided tape to one or both end faces of the cover member 136 in the optical axis direction. By providing the cover member 136 so that it abuts against the barrel member 135 that is disposed on the outermost diameter side of the lens device L0, it is possible to prevent the intrusion of foreign matter such as water droplets, dust, and sand on the outer diameter side of the lens device L0.

[0040] The cover member 136 can be made of a general waterproof and dustproof material such as polyester, polyurethane, elastomer, rubber, etc. By providing the cover member 136 so that it abuts against the cylindrical member 135 arranged on the outer diameter side of the lens device L0, it is possible to prevent foreign matter such as water droplets, dust, and sand from entering the outer diameter side of the lens device L0.

[0041] 17 to 21, modified examples of the cover member in this embodiment will be described.

[0042] In the lens device L0 of Fig. 17, a cover member 137 is disposed radially between the light blocking member 134 and the cylindrical member 135. The light blocking member 134 is an external component, and by disposing the cover member 137 together with the cylindrical member 135 between the two external components, the cover member 137 can be positioned closer to the external component, making it possible to prevent water droplets from entering at an earlier stage. In addition, there is a larger space radially between the light blocking member 134 and the cylindrical member 135 than between them in the optical axis direction. This allows the cover member 137 to have a cubic or rectangular parallelepiped shape, which allows for more components to be used than a doughnut-shaped cover member, thereby keeping costs down.

[0043] 18, a cover member 140 is disposed radially between the first-group barrel 138 and the cylindrical member 139. By disposing the cover member 140 in this manner, the cover member 140 is covered by the exterior member and cannot be seen from the outside, thereby improving the appearance of the lens device L0. Furthermore, the cover member 140 can be shaped like a cube or a rectangular parallelepiped, which has the advantage of allowing for a large number of units to be produced and keeping costs low.

[0044] 19, a cover member 142 is disposed between the light blocking member 134 and the barrel member 141 in the optical axis direction. This arrangement allows the cover member 142 to be covered by the exterior component and not be visible from the outside, improving the appearance of the lens device L0. Furthermore, by disposing the cover member 142 between the two exterior components, the cover member 142 can be positioned closer to the exterior, thereby preventing water droplets from entering at an earlier stage.

[0045] In the lens device L0 of Fig. 20, a cover member 144 is disposed between the first-group barrel 111 and the fourth barrel member 143 in the optical axis direction. In the lens device L0 of Fig. 20, the cover member 144 has an H-shape. This increases the area of ​​contact between the cover member 144 and the first-group barrel 111 and the barrel member 143 when the cover member 144 is brought into contact with the two members, thereby improving drip-proofing and dust-proofing performance.

[0046] In the lens device L0 of Figure 21, the lens G1 (133) positioned closest to the object is held in a different way. The lens G1 (133) is held only by the first-group barrel 145 using thermal caulking technology. A light-shielding member 146 is placed on the object side of the first-group barrel 145 to hide the shape of the first-group barrel 145 after thermal caulking.

[0047] The light blocking member 146 is fixed to the first-group barrel 145 using, for example, a conventional bayonet mechanism and adhesive. Even with this configuration, the drip-proof configuration described in Figures 16 to 20 can be used. In Figure 21, similar to the drip-proof configuration used in Figure 19, a sixth cover member 148 is arranged between the two exterior components, the light blocking member 146 and the barrel member 147, in the optical axis direction. This arrangement is attractive because it is not easily visible from the outside, and provides drip-proofing between the two exterior components, resulting in high drip-proof performance.

[0048] Next, conditions that the lens device L0 of each embodiment should preferably satisfy will be described.

[0049] It is preferable that the lens device L0 in each embodiment satisfies at least one of the following conditional expressions (1) to (12). In each conditional expression, the various numerical values ​​are expressed as follows: fL1 is the focal length of the first lens unit L1, and fL2 is the focal length of the second lens unit L2. fw is the focal length of the lens device L0 at the wide-angle end. fG1 is the focal length of the lens G1 in the first lens unit L1 that is positioned closest to the object, and fG2 is the focal length of the lens G2 that is positioned adjacent to the lens G1 on the image side. fLF is the focal length of the focus unit LF. fLRw is the focal length of the rear unit LR in the lens device L0 at the wide-angle end. Skw is the back focus of the lens device L0 at the wide-angle end. DSPw is the distance on the optical axis from the aperture stop SP of the lens device L0 to the lens surface closest to the image. ndG1 is the refractive index of the lens G1 in the first lens unit L1 that is closest to the object, with respect to the d-line. The radius of curvature of the object-side lens surface of the lens G1 closest to the object in the first lens unit L1 is R1, and the radius of curvature of the image-side lens surface is R2. The maximum image height that can be photographed at the telephoto end of the lens device L0 is Yta, and the maximum image height that can be photographed at the wide-angle end is Ywa. -3.0<fL1 / fw<-1.7 (1) -5.0<|fL2| / fL1<-1.1 (2) 1.4<fG1 / fL1<3.0 (3) 0.40<fG1 / fG2<1.60 (4) 3.5<fLF / fw<15.0 (5) -4.1<fLF / fL1<-1.8 (6) -1.30<fL1 / fLRw<-0.55 (7) 2.0<Skw / fw<6.0 (8) 0.40<DSPw / Skw<1.00 (9) 1.65<ndG1<2.20 (10) 1.3<(R1+R2) / (R1-R2)<3.0 (11) 1.5<Yta / Ywa<3.0 (12)

[0050] Here, the technical meaning of the above-mentioned conditional expressions (1) to (12) will be explained.

[0051] Conditional expression (1) defines the ratio between the focal length fL1 of the first lens unit L1 and the focal length fw of the lens device L0 at the wide-angle end. By satisfying conditional expression (1), the focal length fL1 of the first lens unit L1 can be appropriately positioned, thereby enabling favorable correction of distortion, lateral chromatic aberration, and field curvature. If the focal length fL1 of the first lens unit L1 becomes too long, falling below the lower limit of conditional expression (1), the first lens unit L1 becomes large, making it difficult to miniaturize the lens device L0. If the focal length fL1 of the first lens unit L1 becomes too short, exceeding the upper limit of conditional expression (1), the image height change due to coma becomes large, making it difficult to correct field curvature and astigmatism.

[0052] Conditional expression (2) defines the ratio between the focal length fL2 of the second lens unit L2 and the focal length fL1 of the first lens unit L1. By satisfying conditional expression (2), the focal length fL1 of the first lens unit L1 and the focal length fL2 of the second lens unit L2 can be appropriately positioned, thereby enabling favorable correction of distortion, lateral chromatic aberration, and field curvature. If the focal length fL1 of the first lens unit L1 is too short, falling below the lower limit of conditional expression (2), the image height change due to off-axial coma becomes large, making it difficult to correct field curvature and astigmatism. If the focal length fL1 of the first lens unit L1 is too long, exceeding the upper limit of conditional expression (2), the first lens unit L1 becomes too large, making it difficult to miniaturize the lens device L0.

[0053] Conditional expression (3) defines the ratio between the focal length fG1 of the lens G1 closest to the object in the first lens group L1 and the focal length fL1 of the first lens group L1. By satisfying conditional expression (3), the focal length fG1 of the lens G1 can be appropriately positioned, thereby enabling favorable correction of distortion, lateral chromatic aberration, and field curvature. If the focal length fG1 of the lens G1 falls below the lower limit of conditional expression (3) and becomes too short, it becomes difficult to correct field curvature and distortion. If the focal length fG1 of the lens G1 exceeds the upper limit of conditional expression (3) and becomes too long, the first lens group L1 becomes large, making it difficult to miniaturize the lens device L0.

[0054] Conditional expression (4) defines the ratio between the focal length fG1 of the lens G1 closest to the object in the first lens group L1 and the focal length fG2 of the lens G2 arranged adjacent to the lens G1 on the image side. Two negative lenses are arranged in order from the object side to achieve a wider angle of view. If the focal length fG1 of the lens G1 becomes too short, falling below the lower limit of conditional expression (4), it becomes difficult to correct curvature of field and distortion. If the focal length fG1 of the lens G1 becomes too long, exceeding the upper limit of conditional expression (4), the lens G1 and the first lens group L1 become large, making it difficult to reduce the size of the lens device L0.

[0055] Conditional expression (5) defines the ratio between the focal length fLF of the focus group LF and the focal length fw of the lens apparatus L0 at the wide-angle end. If the focal length fLF of the focus group LF becomes too short, falling below the lower limit of conditional expression (5), it becomes difficult to suppress fluctuations in various aberrations, including spherical aberration, that occur during focusing. If the focal length fLF of the focus group LF becomes too long, exceeding the upper limit of conditional expression (5), the amount of movement that occurs during focusing becomes large, making it difficult to reduce the size of the lens apparatus L0.

[0056] Conditional expression (6) defines the ratio between the focal length fLF of the focus unit LF and the focal length fL1 of the first lens unit L1. If the focal length fLF of the focus unit LF becomes too long, falling below the lower limit of conditional expression (6), the amount of movement required for focusing becomes long, making it difficult to reduce the size of the optical system. If the focal length fLF of the focus unit LF becomes too short, exceeding the upper limit of conditional expression (6), it becomes difficult to suppress fluctuations in various aberrations, including spherical aberration, that occur during focusing.

[0057] Conditional expression (7) defines the ratio between the focal length fL1 of the first lens unit L1 and the focal length fLRw of the rear lens unit LR at the wide-angle end. If the focal length fL1 of the first lens unit L1 becomes too long, falling below the lower limit of conditional expression (7), the convergence action of the rear lens unit LR becomes large, resulting in significant lateral chromatic aberration and axial chromatic aberration, degrading optical performance. If the focal length fL1 of the first lens unit L1 becomes too short, exceeding the upper limit of conditional expression (7), it becomes difficult to correct spherical aberration and coma in the rear lens unit LR.

[0058] Conditional expression (8) defines the ratio between the back focal length Skw at the wide-angle end and the focal length fw of the lens apparatus L0 at the wide-angle end. If the back focal length Skw is too short, falling below the lower limit of conditional expression (8), it becomes difficult to arrange an optical element such as a low-pass filter near an image sensor that photoelectrically converts an optical image formed by the lens apparatus L0. If the back focal length Skw is too long, exceeding the upper limit of conditional expression (8), the total optical length of the lens apparatus L0 at the wide-angle end becomes long, making it difficult to reduce the size.

[0059] Conditional expression (9) defines the ratio of the distance DSPw on the optical axis from the aperture stop SP to the lens surface closest to the image to the back focal length Skw at the wide-angle end. If the distance DSPw on the optical axis from the aperture stop SP to the lens surface closest to the image becomes too short by falling below the lower limit of conditional expression (9), it becomes difficult to arrange the focus group LF. If the back focal length Skw becomes too short by exceeding the upper limit of conditional expression (9), the total optical length of the lens apparatus L0 at the wide-angle end becomes long, making it difficult to reduce the size.

[0060] Conditional expression (10) defines the refractive index ndG1 at the d-line of the material of the lens G1 closest to the object in the first lens unit L1. By satisfying conditional expression (10), the refractive index of the material of the lens G1 can be set within an appropriate range, thereby enabling good correction of lateral chromatic aberration.

[0061] If the lower limit of conditional expression (10) is exceeded and the refractive index ndG1 of the lens G1 closest to the object becomes too small, it becomes necessary to weaken the refractive power of the negative lens in order to correct the curvature of field, which results in an increase in the back focus and makes it difficult to reduce the size of the lens device L0.If the upper limit of conditional expression (10) is exceeded, the refractive index ndG1 of the lens G1 closest to the object becomes too large, which makes it necessary to select a high-dispersion material with a small Abbe number, making it difficult to effectively correct distortion and chromatic aberration of magnification.

[0062] Conditional expression (11) defines the shape of the lens G1 closest to the object in the first lens unit L1. R1 is the radius of curvature of the object-side lens surface of the lens G1 closest to the object, and R2 is the radius of curvature of the image-side lens surface of the lens G1 closest to the object. By satisfying conditional expression (11), if the lower limit of conditional expression (11) is exceeded, the refractive power of the lens G1 closest to the object becomes too strong, making it difficult to obtain high optical performance. If the upper limit of conditional expression (11) is exceeded, the refractive power of the lens G1 closest to the object becomes too weak, making it difficult to obtain a wide angle of view.

[0063] Conditional expression (12) defines the ratio between the maximum image height Yta that can be photographed at the telephoto end and the maximum image height Ywa that can be photographed at the wide-angle end. The maximum image height refers to the distance from the optical axis to the image point that is farthest from the optical axis among the image points that can be photographed. If the maximum image height at the telephoto end falls below the lower limit of conditional expression (12) and becomes too small, it becomes difficult to make the lens apparatus L0 a wide-angle lens apparatus that encompasses a range from a circular fisheye to a diagonal fisheye.

[0064] If the upper limit of conditional expression (12) is exceeded and the maximum image height at the telephoto end becomes too large, the amount of movement of each lens group during zooming or the refractive power of each lens group becomes large, making it difficult to suppress various aberrations during zooming.

[0065] It is preferable that the numerical ranges of the conditional expressions (1) to (12) be the numerical ranges of the following conditional expressions (1a) to (12a). -2.6<fL1 / fw<-1.9 (1a) -3.6<|fL2| / fL1<-1.6 (2a) 1.6<fG1 / fL1<2.7 (3a) 0.47<fG1 / fG2<1.30 (4a) 4.4<fLF / fw<10.0 (5a) -3.9<fLF / fL1<-2.1 (6a) -1.20<fL1 / fLRw<-0.60 (7a) 4.0<Skw / fw<5.3 (8a) 0.50<DSPw / Skw<0.81 (9a) 1.66<ndG1<1.96 (10a) 1.5<(R1+R2) / (R1-R2)<2.7 (11a) 1.8<Yta / Ywa<2.3 (12a)

[0066] It is more preferable that the numerical ranges of the conditional expressions (1) to (12) are the numerical ranges of the following conditional expressions (1b) to (12b). -2.5<fL1 / fw<-2.0 (1b) -3.4<|fL2| / fL1<-1.7 (2b) 1.7<fG1 / fL1<2.6 (3b) 0.48<fG1 / fG2<1.20 (4b) 4.6<fLF / fw<8.0 (5b) -3.7<fLF / fL1<-2.2 (6b) -1.10<fL1 / fLRw<-0.63 (7b) 4.3<Skw / fw<4.9 (8b) 0.53<DSPw / Skw<0.79 ​​(9b) 1.71<ndG1<1.91 (10b) 1.7<(R1+R2) / (R1-R2)<2.5 (11b) 1.9<Yta / Ywa<2.1 (12b)

[0067] Next, a detailed description will be given of the configuration of the lens device L0 according to Examples 1 to 6. Note that in the lens device L0 according to each Example, a description of the overlapping configuration will be omitted, and differences from Example 1 will be mainly described.

[0068] [Example 1] Figure 1 shows a cross-sectional view of a lens device L0 of Example 1. The lens device L0 of Example 1 comprises a first lens unit L1 and a rear lens unit LR. In the lens device L0 of Example 1, the rear lens unit LR comprises a second lens unit L2 with negative refractive power, a third lens unit L3 with positive refractive power, a fourth lens unit L4 with positive refractive power, and a fifth lens unit L5 with negative refractive power. During zooming from the wide-angle end to the telephoto end, the first lens unit L1 remains stationary relative to the image plane, while the second lens unit L2, the third lens unit L3, the fourth lens unit L4, and the fifth lens unit L5 move toward the object side. The focus unit LF is the fourth lens unit L4.

[0069] In the lens device L0 of Example 1, the first lens group L1 is composed of two negative lenses. The second lens group L2 is composed of, arranged in order from the object side, one negative lens, a cemented lens consisting of a positive lens and a negative lens, and a cemented lens consisting of a negative lens and a positive lens. The third lens group L3 is composed of, arranged in order from the object side, a cemented lens consisting of two positive lenses and a negative lens, an aperture stop, and one positive lens. The fourth lens group L4 is composed of, arranged in order from the object side, a negative lens and a positive lens. The fifth lens group L5 is composed of two cemented lenses consisting of a negative lens and a positive lens. Having three cemented lenses in the optical system further improves the correction effect of axial chromatic aberration.

[0070] 3 shows a cross-sectional view of a lens device L0 of Example 2. In the lens device L0 of Example 2, the third lens unit L3 is composed of, arranged in order from the object side, one positive lens, a cemented lens composed of a negative lens and a positive lens, an aperture stop, and one positive lens.

[0071] 5 shows a cross-sectional view of a lens device L0 of Example 3. In the lens device L0 of Example 3, the second lens group L2 is composed of, arranged in order from the object side, a cemented lens consisting of a positive lens and a negative lens, one negative lens, and a cemented lens consisting of a negative lens and a positive lens. The third lens group L3 is composed of, arranged in order from the object side, one positive lens, a cemented lens consisting of a positive lens and a negative lens, one positive lens, and an aperture stop.

[0072] [Example 4] Fig. 7 shows a cross-sectional view of a lens device L0 of Example 4. In the lens device L0 of Example 4, the second lens group L2 is composed of, in order from the object side, a positive lens, a negative lens, a negative lens, and a positive lens. The third lens group L3 is composed of, in order from the object side, a cemented lens composed of a positive lens and a negative lens, a cemented lens composed of a positive lens, a negative lens, and a positive lens, and an aperture stop. The fourth lens group L4 is composed of, in order from the object side, a positive lens and a negative lens. The fifth lens group L5 is composed of, in order from the object side, a negative lens and a positive lens.

[0073] [Embodiment 5] Figure 9 shows a cross-sectional view of a lens device L0 of embodiment 5. The lens device L0 of embodiment 5 comprises a first lens unit L1 and a rear lens unit LR. In the lens device L0 of embodiment 5, the rear lens unit LR comprises a second lens unit L2 with negative refractive power, a third lens unit L3 with positive refractive power, a fourth lens unit L4 with positive refractive power, a fifth lens unit L5 with positive refractive power, and a sixth lens unit L6 with negative refractive power. During zooming from the wide-angle end to the telephoto end, the first lens unit L1 remains stationary relative to the image plane, while the second lens unit L2, the third lens unit L3, the fourth lens unit L4, the fifth lens unit L5, and the sixth lens unit L6 move toward the object side. The focus unit LF is the fifth lens unit L5.

[0074] In the lens device L0 of Example 5, the second lens group L2 is composed of, in order from the object side, a positive lens and a negative lens. The third lens group L3 is composed of a cemented lens consisting of a positive lens and a negative lens. The fourth lens group L4 is composed of, in order from the object side, two cemented lenses consisting of a negative lens and a positive lens, and an aperture stop. The fifth lens group L5 is composed of one positive lens. The sixth lens group L6 is composed of, in order from the object side, a negative lens, a positive lens, and a cemented lens consisting of a negative lens and a positive lens.

[0075] [Example 6] Fig. 11 shows a cross-sectional view of a lens device L0 of Example 6. In the lens device L0 of Example 6, the second lens unit L2 is composed of a cemented lens consisting of a negative lens and a positive lens, and one negative lens. The third lens unit L3 is composed of a cemented lens consisting of a positive lens and a negative lens. The fourth lens unit L4 is composed of a cemented lens consisting of a positive lens, a negative lens, and a positive lens, and an aperture stop. The fifth lens unit L5 is composed of a positive lens and a negative lens, arranged in order from the object side. The sixth lens unit L6 is composed of a cemented lens consisting of a positive lens, a negative lens, and a positive lens, arranged in order from the object side.

[0076] By having three cemented lenses in the optical system, the effect of correcting axial chromatic aberration can be further improved.

[0077] In the lens device L0 of each embodiment, it is preferable that the first lens unit L1 has two or more negative lenses, in order from the object side. It is also preferable that the lens G1 closest to the object side has a meniscus shape convex toward the object side, and that the vertex of the object-side surface of the lens G1 closest to the object side is located closer to the object side than the first lens barrel. This makes it easy to achieve a wide angle of view for the lens device L0.

[0078] In the lens device L0 of each embodiment, the object-side lens surface and the image-side lens surface of the lens G1 located closest to the object are preferably meniscus-shaped with a convex surface facing the object side, which facilitates the manufacture of the lens device L0 while satisfying the required optical performance.Furthermore, it is preferable that the first lens group L1 is composed of two negative lenses and that all of the lenses included in the first lens group L1 are spherical lenses, which further facilitates the manufacture of the lens device L0.

[0079] In the lens device L0 of each embodiment, it is preferable to configure the focus group LF with two or less lenses and place it closer to the image side than the aperture stop SP, as this makes it easier to reduce the size of the focus group LF and increase the focusing speed.

[0080] In the lens device L0 of each embodiment, it is more preferable to configure the rear group LR with three or more lens groups, since this makes it possible to achieve a sufficient zoom ratio.

[0081] The lens device L0 of each embodiment may be provided with distortion correction data for correcting distortion, thereby allowing distortion occurring in the lens optical system to be corrected by the lens device L0.

[0082] In addition, in the lens device L0 of each embodiment, any of the cover member arrangement methods shown in FIGS. 16 to 21 may be adopted, or a combination of a plurality of arrangement methods may be used to arrange the cover members.

[0083] Next, Numerical Examples 1 to 6 corresponding to Examples 1 to 6, respectively, are shown below. In the surface data of each Numerical Example, r represents the radius of curvature of each optical surface, and d (mm) represents the distance on the optical axis between the mth surface and the (m+1)th surface. Here, m is the surface number counted from the light incident side. Furthermore, nd represents the refractive index of the material of each optical element with respect to the d-line, and vd represents the Abbe number of the material of the optical element. Note that the Abbe number vd of a certain material is expressed as follows, where Nd, NF, and NC are the refractive indices at the d-line (587.6 nm), F-line (486.1 nm), and C-line (656.3 nm) of the Fraunhofer lines.

[0084] In each numerical example, d, focal length (mm), F-number, and half angle of view (°) are all values ​​when the lens device L0 of each example is focused on an object at infinity. The back focus is the distance on the optical axis from the lens surface closest to the image of the lens device L0 to the paraxial image plane, expressed as an air-equivalent length. The total lens length is the distance on the optical axis from the front surface (the lens surface closest to the object) of the lens device L0 to the final surface, plus the back focus. The lens group in each numerical example is not limited to being composed of multiple lenses, but may also be composed of a single lens.

[0085] If the optical surface is aspherical, a * symbol is added to the right of the surface number. The aspherical shape is expressed as follows, where X is the displacement from the vertex of the surface in the optical axis direction, h is the height from the optical axis in a direction perpendicular to the optical axis, R is the paraxial radius of curvature, K is the conic constant, and A4, A6, A8, A10, and A12 are aspherical coefficients of each order: X=(h ２ / R) / [1+[1-(1+K)(h / R) ２ ] １／２ ]+A4×h ４ + A6 x h ６ +A8 x h ８ + A10 x h １０ + A12 x h １２ + A14 x h １４ In addition, "e±XX" in each aspherical coefficient is "×10± ＸＸ " represents.

[0086] [Numerical Example 1] Unit: mm Surface data Surface number rd nd νd 1 48.932 2.00 1.85150 40.8 2 20.284 16.25 3 557.363 1.10 1.80400 46.5 4 28.772 (variable) 5 34.855 0.90 1.85896 22.7 6 17.068 0.10 1.53344 52.7 7* 17.589 4.70 8 50.857 6.99 1.83400 37.2 9 -20.635 1.05 1.49700 81.7 10 22.129 4.34 11 -16.265 0.80 1.49700 81.7 12 21.161 3.64 1.66565 35.6 13 -55.693 (Variable) 14 21.234 3.68 1.63980 34.5 15 -27.788 0.70 1.90043 37.4 16 12.518 4.24 1.59270 35.3 17 -87.908 0.91 18(Aperture) ∞ 2.09 19 42.390 4.09 1.49700 81.7 20 -19.741 (Variable) 21 -19.756 0.90 2.00100 29.1 22 -46.915 0.10 1.53344 52.7 23* -32.818 0.25 24 49.974 5.10 1.49700 81.7 25 -15.524 (variable) 26 -39.407 0.70 1.81600 46.6 27 24.127 5.47 1.49700 81.7 28 -23.248 (variable) Image surface ∞ Aspheric data Surface 7 K = 0.00000e+00 A4= 4.48181e-07 A6= 3.99220e-08 A8=-9.08985e-11 A10= 1.59194e-12 A12=-4.38981e-15 Surface 23 K = 0.00000e+00 A4= 6.12566e-05 A6= 1.17826e-07 A8= 2.22470e-09 A10=-3.70114e-11 A12= 2.37590e-13 Various data Zoom ratio 2.00 Wide-angle Mid-range Telephoto Focal length 6.81 9.58 13.60 F-number 2.85 3.23 3.60 Half angle of view 94.94 87.43 89.96 Image height 11.15 14.80 21.64 Lens length 127.71 127.71 127.71 BF 30.73 40.08 49.42 d 4 6.34 6.31 2.10 d13 15.72 6.40 1.27 d20 2.33 3.71 3.67 d25 2.47 1.10 1.14 d28 30.73 40.08 49.42 Lens device group data Group Initial surface Focal length L1 1 -16.55 L2 5 -42.17 L3 14 26.64 L4 21 47.74 L5 26 -101.75 .

[0087] [Numerical Example 2] Unit: mm Surface data Surface number rd nd νd 1 55.485 2.30 1.85150 40.8 2 19.371 17.05 3 -1103.546 1.30 1.90525 35.0 4 34.645 (variable) 5 37.524 0.90 1.89286 20.4 6 18.491 0.10 1.58946 30.6 7* 18.199 2.37 8 31.026 8.14 1.78880 28.4 9 -20.624 1.10 1.49700 81.7 10 16.423 5.40 11 -14.389 0.80 1.49700 81.7 12 18.091 3.89 1.61340 44.3 13 -39.413 (variable) 14 18.952 4.42 1.53172 48.8 15 -17.614 0.09 16 -17.868 0.70 1.88300 40.8 17 15.902 4.19 1.59270 35.3 18 -41.659 1.44 19(Aperture) ∞ 1.27 20 34.703 4.01 1.49700 81.7 21 -25.217 (variable) 22 -26.388 0.80 1.88300 40.8 23 -78.439 0.10 1.53344 52.7 24* -49.028 0.15 25 31.715 4.97 1.49700 81.7 26 -18.785 (variable) 27 -53.258 0.75 1.88300 40.8 28 19.564 4.78 1.49700 81.7 29 -25.590 (variable) Image plane ∞ Aspheric data Surface 7 K = 0.00000e+00 A 4=-9.88827e-06 A 6= 6.80002e-09 A 8=-9.44113e-12 A10= 1.04890e-12 A12=-2.43934e-15 Surface 24 K = 0.00000e+00 A 4= 5.68392e-05 A 6= 1.09227e-07 A 8= 3.24013e-10 A10= 1.13582e-12 A12=-2.42531e-14 Various data Zoom ratio 1.97 Wide-angle Mid-range Telephoto Focal length 6.80 9.52 13.41 F-number 2.86 3.22 3.61 Half angle of view 95.03 88.50 91.04 Image height 11.15 14.80 21.60 Lens length 126.11 126.11 126.11 BF 30.90 39.23 47.55 d 4 4.47 5.13 1.29 d13 14.12 5.13 0.65 d21 4.03 3.69 2.74 d26 1.58 1.92 2.87 d29 30.90 39.23 47.55 Lens System Data Group Initial Surface Focal Length L1 1 -14.82 L2 5 -38.96 L3 14 27.05 L4 22 39.68 L5 27 -68.35

[0088] [Numerical Example 3] Unit: mm Surface data Surface number rd nd νd 1 52.863 2.00 1.85150 40.8 2 19.811 16.64 3 268.068 1.30 2.00100 29.1 4 31.150 (variable) 5 159.698 4.99 1.95375 32.3 6 -30.207 1.20 1.49700 81.7 7 16.611 5.20 8 -17.533 0.80 1.49700 81.7 9 18.643 0.28 10 19.966 6.58 1.78880 28.4 11 -12.466 0.80 2.00100 29.1 12 -61.500 (Variable) 13* 55.457 0.10 1.58946 30.6 14 97.068 3.52 1.56732 42.8 15 -14.576 0.05 16 -14.461 0.80 2.00100 29.1 17 22.989 3.89 1.59270 35.3 18 -25.500 0.15 19 52.181 4.70 1.63980 34.5 20 -16.612 0.30 21(Aperture) ∞ (Variable) 22 -20.107 0.80 1.95375 32.3 23 -48.225 0.10 1.58946 30.6 24* -37.531 0.15 25 48.217 4.74 1.49700 81.7 26 -16.669 (variable) 27 -101.305 0.80 1.88300 40.8 28 18.672 3.74 1.49700 81.7 29 -30.910 (variable) Image plane ∞ Aspheric data Surface 13 K = 0.00000e+00 A 4=-5.40095e-05 A 6=-1.58648e-07 A 8=-6.84435e-09 A10= 1.41530e-10 A12=-1.69897e-12 Surface 24 K = 0.00000e+00 A 4= 3.89315e-05 A 6= 1.19235e-07 A 8=-4.99023e-10 A10= 1.75021e-11 A12=-1.12723e-13 Various data Zoom ratio 1.97 Wide angle Mid-range Telephoto Focal length 6.82 9.56 13.42 F-number 2.83 3.21 3.60 Half angle of view 94.95 88.37 91.14 Image height 11.15 14.80 21.60 Lens length 123.73 123.73 123.73 BF 32.13 40.19 48.25 d 4 7.71 7.34 3.55 d12 13.02 5.32 1.05 d21 5.99 6.19 5.14 d26 1.25 1.05 2.10 d29 32.13 40.19 48.25 Lens System Data Group Initial Surface Focal Length L1 1 -14.97 L2 5 -42.81 L3 13 23.42 L4 22 53.48 L5 27 -82.35

[0089] [Numerical Example 4] Unit: mm Surface data Surface number rd nd νd 1 60.163 2.60 1.83481 42.7 2 21.063 12.33 3 109.832 1.50 1.59522 67.7 4 17.672 (variable) 5 150.019 4.20 1.72047 34.7 6 -51.359 1.58 7 -37.627 0.90 1.89190 37.1 8 91.089 2.62 9 -17.827 0.85 1.49700 81.7 10 19.500 0.71 11 24.491 4.63 1.75520 27.5 12 -127.292 (variable) 13* 32.487 0.05 1.58946 30.6 14 24.928 6.44 1.53172 48.8 15 -10.792 0.85 2.00100 29.1 16 -49.566 0.15 17 260.837 3.61 1.59270 35.3 18 -19.964 0.06 19 -83.132 0.90 1.77250 49.6 20 12.974 5.93 1.59270 35.3 21 -21.635 0.87 22 (Aperture) ∞ (Variable) 23 20.807 4.87 1.49700 81.7 24 -19.178 0.15 25 -22.797 0.80 2.00100 29.1 26 -66.112 (Variable) 27 -2019.764 0.80 1.88300 40.8 28 21.543 2.23 29 31.926 3.93 1.49700 81.7 30 -24.775 (variable) Image surface ∞ Aspheric data Surface 13 K = 0.00000e+00 A4= 7.64291e-06 A6= 4.60507e-07 A8=-1.46830e-08 A10= 3.93238e-10 A12=-3.23460e-12 Other data Zoom ratio 2.06 Wide-angle Mid-range Telephoto Focal length 7.22 10.80 14.86 F-number 2.88 3.61 4.12 Half angle of view 99.23 96.79 92.92 Image height 10.75 16.00 21.60 Total lens length 128.99 128.99 128.99 BF 32.52 42.88 49.78 d 4 9.19 8.61 5.93 d12 14.96 5.18 0.95 d22 7.59 6.65 3.60 d26 1.17 2.11 5.15 d30 32.52 42.88 49.78 Lens unit data Unit Initial surface Focal length L1 1 -16.14 L2 5 -36.44 L3 13 35.25 L4 23 46.70 L5 27 -822.66.

[0090] [Numerical Example 5] Unit: mm Surface data Surface number rd nd νd 1 58.998 2.50 1.76385 48.5 2 15.716 16.74 3 -118.695 1.40 1.59282 68.6 4 37.945 (variable) 5 52.243 3.96 1.66565 35.6 6 -30.668 0.59 7 -22.962 1.00 1.90043 37.4 8 23.854 (variable) 9 23.518 3.91 1.66565 35.6 10 -20.591 1.00 1.49700 81.7 11 22.024 (Variable) 12 18.264 1.00 1.88300 40.8 13 11.917 4.60 1.68430 26.8 14 -39.891 0.15 15 -32.692 1.00 2.05090 26.9 16 17.207 5.02 1.59410 60.5 17 -18.631 0.50 18(Aperture) ∞ (Variable) 19 20.545 2.96 1.53775 74.7 20 -202.410 (Variable) 21 -60.820 1.28 1.77250 49.6 22* 52.786 0.52 23 80.866 3.72 1.49700 81.7 24 -23.726 0.15 25 -31.425 1.31 1.88300 40.8 26 52.500 3.91 1.49700 81.7 27 -17.095 (variable) Image plane ∞ Aspheric data Surface 22 K = 0.00000e+00 A4= 2.64230e-05 A6=-4.03358e-09 A8= 7.40566e-10 A10=-2.79295e-11 A12= 2.33887e-13 Other data Zoom ratio 2.03 Wide angle Mid-range Telephoto Focal length 7.24 10.93 14.69 F-number 4.10 4.10 4.10 Half angle of view 98.14 94.28 93.38 Image height 10.75 16.00 21.60 Lens length 127.38 127.38 127.38 BF 32.32 43.68 51.25 d 4 13.34 9.39 4.19 d 8 5.91 6.34 6.60 d 11 11.80 3.96 1.33 d 18 3.21 3.73 3.00 d 20 3.58 3.06 3.79 d 27 32.32 43.68 51.25 Lens System Data Group Initial Surface Focal Length L1 1 -14.79 L2 5 -25.40 L3 9 64.83 L4 12 41.50 L5 19 34.85 L6 21 -442.01

[0091] [Numerical Example 6] Unit: mm Surface data Surface number rd nd νd 1 58.154 2.50 1.76385 48.5 2 15.775 16.08 3 -425.603 1.40 1.59282 68.6 4 37.744 (variable) 5 248.610 5.62 1.77047 29.7 6 -19.550 1.00 1.95906 17.5 7 -38.557 (variable) 8 -22.637 1.00 1.91354 36.8 9 28.532 3.85 10 28.132 5.18 1.77047 29.7 11 -21.134 1.00 1.43875 94.7 12 22.654 (Variable) 13 24.356 6.32 1.68430 26.8 14 -13.488 1.00 2.00100 29.1 15 28.481 4.91 1.51823 58.9 16 -15.181 0.40 17(Aperture) ∞ (Variable) 18 22.580 3.05 1.49700 81.7 19 -104.450 (Variable) 20 -34.188 1.28 1.76450 49.1 21* 87.503 2.04 22 32.469 4.26 1.49700 81.7 23 -18.234 0.15 24 -176.617 1.31 1.88300 40.8 25 19.236 3.68 1.49700 81.7 26 -61.995 (variable) Image plane ∞ Aspheric data Surface 21 K = 0.00000e+00 A4= 3.50880e-05 A6= 1.70964e-08 A8= 3.91104e-09 A10=-9.58126e-11 A12= 7.92141e-13 Other data Zoom ratio 2.06 Wide-angle Mid-range Telephoto Focal length 7.25 11.01 14.97 F-number 4.10 4.10 4.10 Half angle of view 97.86 93.05 90.55 Image height 10.75 16.00 21.60 Lens length 131.41 131.41 131.41 BF 32.32 43.52 50.99 d 4 11.62 9.61 3.44 d 7 1.54 1.48 2.68 d 12 13.54 4.41 1.90 d 17 4.43 4.43 3.35 d 19 1.92 1.92 3.00 d 26 32.32 43.52 50.99 Lens System Data Group Initial Surface Focal Length L1 1 -16.36 L2 5 54.77 L3 8 -23.38 L4 13 42.94 L5 18 37.66 L6 20 -345.10

[0092] The various values ​​in each numerical example are summarized in Table 1 below.

[0093]

[0094] [Image Capture Apparatus] Next, an image capture apparatus using the lens device L0 of this embodiment will be described. Fig. 13 is a schematic diagram of an image capture apparatus 10 of this embodiment. The image capture apparatus 10 includes a camera body 13, a lens device 11 similar to any of the lens devices 11 of the first to sixth embodiments, and a light receiving element 12 that photoelectrically converts an optical image formed by the lens device 11.

[0095] The imaging device 10 of this embodiment has a lens device 11 that is small and has good optical characteristics, and therefore can obtain high-quality images.

[0096] It should be noted that an imaging element such as a CCD or CMOS sensor can be used as the light receiving element 12. In this case, various aberrations such as distortion and chromatic aberration of the image acquired by the light receiving element 12 can be electrically corrected to improve the image quality of the output image.

[0097] The lens device L0 of each of the above-described embodiments can be applied not only to the digital still camera shown in FIG. 13 but also to various optical devices such as silver halide film cameras, video cameras, and telescopes.

[0098] Although the preferred embodiments and examples of the present disclosure have been described above, the present invention is not limited to these embodiments and examples, and various combinations, modifications, and changes are possible within the scope of the gist of the present disclosure.

[0099] The present disclosure is not limited to the above-described embodiments, and various modifications and variations can be made without departing from the spirit and scope of the present disclosure. Therefore, to apprise the public of the scope of the present disclosure, the following claims are appended.

[0100] This application claims priority based on Japanese Patent Application No. 2024-108628, filed on July 5, 2024, the entire contents of which are incorporated herein by reference.

Claims

1. A lens device comprising, arranged in order from the object side to the image side, a first lens group having negative refractive power and a rear group including one or more lens groups, wherein the first lens group remains stationary relative to the image plane during zooming, and the spacing between adjacent lens groups changes during zooming, and wherein, when the half angle of view when focusing on infinity at the wide-angle end is ωw (°), the lens device satisfies the condition ωw>85, wherein the lens device comprises a first lens barrel, a light blocking member located on the object side of the first lens barrel, and a cylindrical member located on the outer diameter side of the light blocking member, and wherein a cover member is provided between at least one of the light blocking member and the cylindrical member or the first lens barrel and the cylindrical member.

2. The lens device according to claim 1, wherein the half angle of view satisfies ωw>94.

3. The lens apparatus according to claim 1 or 2, wherein the following condition is satisfied: -3.0<fL1 / fw<-1.7, where fL1 is the focal length of the first lens group and fw is the focal length of the lens apparatus at the wide-angle end.

4. The lens apparatus according to any one of claims 1 to 3, characterized in that the rear group includes a second lens group having negative refractive power, and the following condition is satisfied, where fL2 is the focal length of the second lens group and fL1 is the focal length of the first lens group: -5.0<|fL2| / fL1<-1.1 5. The lens apparatus according to any one of claims 1 to 4, characterized in that the following condition is satisfied: 1.4<fG1 / fL1<3.0, where fG1 is the focal length of the lens G1 in the first lens group that is positioned closest to the object, and fL1 is the focal length of the first lens group.

6. The lens apparatus according to any one of claims 1 to 5, characterized in that the following condition is satisfied: 0.40<fG1 / fG2<1.60, where fG1 is the focal length of the lens G1 arranged closest to the object in the first lens group, and fG2 is the focal length of the lens G2 arranged adjacent to the lens G1 on the image side.

7. A lens apparatus according to any one of claims 1 to 6, characterized in that it has a focus group that moves relative to an image plane during focusing, and where fLF is the focal length of the focus group and fw is the focal length of the lens apparatus at the wide-angle end, the following conditional expression is satisfied: 3.5<fLF / fw<15.0 8. The lens apparatus according to any one of claims 1 to 7, characterized in that it has a focus group that moves relative to the image plane during focusing, and where the focal length of the focus group is fLF and the focal length of the first lens group is fL1, it satisfies the following condition: -4.1<fLF / fL1<-1.8 9. The lens apparatus according to any one of claims 1 to 8, characterized in that the following condition is satisfied: -1.30<fL1 / fLRw<-0.55, where fL1 is the focal length of the first lens group and fLRw is the focal length of the rear group at the wide-angle end.

10. The lens device according to any one of claims 1 to 9, wherein the following condition is satisfied: 2.0<Skw / fw<6.0, where Skw is the back focus at the wide-angle end and fw is the focal length of the lens device at the wide-angle end.

11. A lens apparatus according to any one of claims 1 to 10, characterized in that it is provided with an aperture stop, and the following condition is satisfied, where DSPw is the distance on the optical axis from the aperture stop to the lens surface closest to the image in the entire system of the lens apparatus, and Skw is the back focus at the wide-angle end: 0.40<DSPw / Skw<1.00 12. The lens device according to any one of claims 1 to 11, characterized in that the following condition is satisfied: 1.65<ndG1<2.20, where ndG1 is the refractive index at the d-line of the material of the lens G1 arranged closest to the object in the first lens group.

13. The lens apparatus according to any one of claims 1 to 12, characterized in that the lens G1 arranged closest to the object side in the first lens group has a meniscus shape with a convex surface facing the object side, and the following condition is satisfied, where R1 is the radius of curvature of the object-side lens surface of said lens G1 and R2 is the radius of curvature of the image-side lens surface of said lens G1: 1.3<(R1+R2) / (R1-R2)<3.0 14. A lens device according to any one of claims 1 to 13, characterized in that the following condition is satisfied: 1.5<Yta / Ywa<3.0, where Yta is the maximum image height at the telephoto end and Ywa is the maximum image height at the wide-angle end.

15. A lens device according to any one of claims 1 to 14, characterized in that it comprises distortion correction data for correcting distortion aberration.

16. A lens device according to any one of claims 1 to 15, wherein the first lens group consists of at least two negative lenses.

17. A lens device according to any one of claims 1 to 16, characterized in that it has a focus group that moves relative to the image plane during focusing, and the focus group is made up of two or less lenses.

18. A lens device according to any one of claims 1 to 17, wherein the lens surfaces of the lenses included in the first lens group are spherical.

19. A lens device according to any one of claims 1 to 18, wherein the rear group comprises three or more lens groups.

20. A lens device according to any one of claims 1 to 19, characterized in that the lens G1 closest to the object in the first lens group has a meniscus shape with a convex surface facing the object side, and the vertex of the object-side surface of the lens G1 is located closer to the object than the first lens barrel.

21. A lens device according to any one of claims 1 to 20, comprising an aperture stop and a focus group that moves relative to the image plane during focusing, the focus group being positioned closer to the image side than the aperture stop.

22. A lens device according to any one of claims 1 to 21, characterized in that the rear group consists of, arranged in order from the object side to the image side, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having positive refractive power, and a fifth lens group having negative refractive power.

23. A lens device according to any one of claims 1 to 22, characterized in that the rear group consists of, arranged in order from the object side to the image side, a second lens group having positive refractive power, a third lens group having negative refractive power, a fourth lens group having positive refractive power, a fifth lens group having positive refractive power, and a sixth lens group having negative refractive power.

24. A lens device according to any one of claims 1 to 23, characterized in that the first lens group abuts against the first lens barrel, and the barrel member is located closer to the image plane than the object-side end of the light-shielding member.

25. The lens device according to claim 24, wherein the first lens group abuts against the light blocking member.

26. A lens device according to any one of claims 1 to 25, characterized in that the cover member is provided between the light blocking member and the cylindrical member, and between the first lens barrel and the cylindrical member.

27. An imaging device comprising the lens device according to any one of claims 1 to 26 and an imaging element that receives an image formed by the lens device.

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