JP2026008164A - Lens device and imaging device having the same - Google Patents

Abstract

To provide a lens device with excellent drip-proof and dust-proof properties and a wide angle of view.
[Solution] A lens device comprising a first lens group having negative refractive power and a rear group including one or more lens groups, arranged in that order from the object side to the image side, wherein during zooming, the lens G1 of the first lens group arranged closest to the object remains stationary relative to the image plane, and during zooming, the spacing between adjacent lens groups changes, and where ωw (°) is the half angle of view when focusing at infinity at the wide-angle end, the lens device satisfies the condition ωw>85, and the lens device comprises a first lens barrel, a light-blocking member arranged closer to the object than 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 either the light-blocking member and the cylindrical member or the first lens barrel and the cylindrical member.
[Selected Figure] Figure 1

Description

The present invention relates to a lens device and an imaging device incorporating the same, and is suitable for imaging devices using solid-state imaging elements such as digital still cameras, video cameras, broadcast cameras, surveillance cameras, and vehicle-mounted cameras, as well as cameras using silver halide photographic film.

Lens devices used in imaging devices are required to have good optical characteristics while providing a wide angle of view. Known wide-angle lens devices include negative-lead lens devices, such as those disclosed in Patent Document 1, in which a lens group with negative refractive power is positioned closest to the object.

Japanese Patent Application Laid-Open No. 2020-166234

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, the cover members required for drip-proofing and dust-proofing must be provided in appropriate positions on the lens device.

One aspect of the present invention is 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. During zooming, the lens G1 in the first lens group, which is located closest to the object, remains stationary relative to the image plane. The spacing between adjacent lens groups changes during zooming. 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. The lens device includes a first lens barrel, a light-blocking member located closer to the object than the first lens barrel, and a barrel member located on the outer diameter side of the light-blocking member. A cover member is provided between at least either the light-blocking member and the barrel member or the first lens barrel and the barrel member. An imaging device including the lens device also constitutes another aspect of the present invention.

It is possible to provide a wide-angle lens device with excellent moisture and dust resistance.

1 is a cross-sectional view of a lens device according to a first embodiment of the present invention; Aberration diagram of the lens device of Example 1 10 is a cross-sectional view of a lens device according to a second embodiment of the present invention; Aberration diagram of the lens device of Example 2 10 is a cross-sectional view of a lens device according to a third embodiment of the present invention; Aberration diagram of the lens device of Example 3 10 is a cross-sectional view of a lens device according to a fourth embodiment of the present invention; Aberration diagram of the lens device of Example 4 10 is a cross-sectional view of a lens device according to a fifth embodiment of the present invention; Aberration diagram of the lens device of Example 5 10 is a cross-sectional view of a lens device according to a sixth embodiment of the present invention; Aberration diagram of the lens device of Example 6 Schematic diagram of the imaging device 1 is a cross-sectional view showing a lens barrel according to an embodiment of the present invention; Diagram showing the shape of the rear fixed barrel into which the filter barrel is installed FIG. 10 is an enlarged cross-sectional view showing a drip-proof structure arranged in the optical axis direction on the inner diameter side around the lens G1. An enlarged cross-sectional view showing the drip-proof structure arranged in the radial direction on the exterior side around the lens G1. An enlarged cross-sectional view showing a drip-proof structure arranged in the radial direction on the inner diameter side around the lens G1. FIG. 10 is an enlarged cross-sectional view showing a drip-proof structure arranged in the direction of the optical axis on the exterior side around the lens G1. FIG. 10 is an enlarged cross-sectional view showing a drip-proof structure arranged in the optical axis direction on the inner diameter side around the lens G1. FIG. 10 is an enlarged cross-sectional view showing a drip-proof structure arranged in the direction of the optical axis on the exterior side around the lens G1.

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

Figures 1, 3, 5, 7, 9, and 11 show cross-sectional views of the lens device L0 of Examples 1 to 6 at the wide-angle end when focused on infinity. The lens device 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.

The lens device L0 in each embodiment is composed of multiple lens groups. Note that in this specification, a lens group refers to a group of one or more lenses that move as a unit 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.

In each cross-sectional view, Li represents 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. LR represents the rear group, which includes all lenses and lens groups arranged closer to the image side than the first lens group L1.

In each cross-sectional view, SP denotes the aperture stop. In each cross-sectional view, IP denotes the image plane, and when the lens device 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 device L0 of each embodiment is used as the photographic optical system of a silver halide film camera, a photosensitive surface equivalent to the film surface is disposed at the image plane IP.

The solid arrows shown in each lens cross-sectional diagram are a simplified representation of the movement trajectory of each lens group when zooming from the wide-angle end to the telephoto end. Note that in this specification, the wide-angle end and telephoto end refer to the respective zoom positions when each lens group is located at the ends of the range of movement along the optical axis. The dashed arrows shown in each lens cross-sectional diagram are a simplified representation of the movement trajectory of the focus group LF as it moves relative to the image plane when focusing from infinity to a close distance.

The lens device L0 in each embodiment consists of a first lens group L1 with negative refractive power and a rear group LR including one or more lens groups, arranged in that order from the object side to the image side. The rear group LR includes all lens groups arranged closer to the image side than the first lens group 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 infrared cut filter, may be arranged between the lens arranged closest to the image side and the imaging surface.

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

In the spherical aberration diagrams, Fno is the F-number, 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 for the g-line. Also, in each aberration diagram, ω is the imaging half angle of view (°), which is the angle of view calculated by paraxial calculation.

In the lens device L0 of each embodiment, the projection method of Examples 1 to 3 employs the conformal projection method, expressed by the formula Y = f · θ. Furthermore, the projection method of Examples 4 to 6 employs the equisolid angle projection method, expressed 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 also be used.

Figure 14 is a cross-sectional view of the lens barrel in this embodiment. The line X-X in the figure represents the optical axis. In Figure 14, the mount 101 is a component fixed to the camera body (not shown). The guide barrel 102 is fixed integrally to the mount 101 along with the rear fixed barrel 131 and intermediate fixed barrel 132. A cam ring 104 is held on the outer periphery of the guide barrel 102 so that it can rotate freely around the optical axis. The cam ring 104 is connected to the 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.

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 the control board 107 and transmits focal length information during zooming to the control circuit.

The control board 107 is electrically connected to a contact block 108, and communicates with the camera body (not shown) and supplies power.

The first lens group L1 is held in the first group barrel 111, which is in contact with the guide barrel 102.

The second lens group L2 is held in the second group barrel 112 and abuts against the second group base barrel 119.

The third lens group L3 is held in the third group barrel 113 and abuts against the rear group base barrel 120.

The fourth lens group L4 is held in the fourth-group barrel 114 and abuts against the rear-group base barrel 120.

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

The fifth lens group L5 is held in a fifth-group barrel 115, which is held by a guide bar (not shown) so that it can move in the optical axis direction relative to the rear-group base barrel 120. The fifth lens group L5 is a focus adjustment lens, 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).

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

The fifth-group lens barrel 115, used for focus adjustment, is held by the rear-group base lens barrel 120, and therefore moves together with the rear-group base lens barrel 120 during zooming, while being driven in the optical axis direction by a stepping motor 122.

The filter 110 is held in the filter barrel 117 and is installed 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 installed.

Next, we will describe the characteristic configuration of the lens device L0 in each embodiment.

The lens device L0 in each embodiment is a negative-lead type lens device in which the first lens group L1 has negative refractive power. Of the lenses included in the first lens group L1, the lens G1 closest to the object is fixed with respect 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.

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

Furthermore, as shown in FIG. 14, the lens device L0 in each embodiment includes a first lens barrel 111 that holds the lens G1, a light blocking member 134 located on the object side of the first lens barrel, and a cylindrical member 135 located on the outer diameter side of the light blocking member 134.

As mentioned above, the first lens barrel 111 abuts against the guide barrel 102 and holds the first lens group L1. The light-blocking member 134 prevents unwanted light from entering the lens device L0 from the outside.

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

Now, with reference to Figure 16, we will explain the cover member in this embodiment.

Figure 16 is an enlarged view of the area enclosed by the dashed square in Figure 14, showing only the components of the lens device L0 of this embodiment that are related to the drip-proof configuration.

In the lens device L0 of each embodiment, as shown in FIG. 16, the lens G1 (133) arranged closest to the object in the lens device L0 is held by the first-group barrel 111 and the light-blocking member 134. The light-blocking member 134 abuts the first-group barrel 111 and also abuts 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.

In addition, 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 disposing the cover member 136 so that it abuts the barrel member 135 that is positioned 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.

The cover member 136 can be made of a typical waterproof and dustproof material such as polyester, polyurethane, elastomer, or rubber. By providing the cover member 136 so that it abuts against the tubular member 135 located on the outer 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.

Modifications of the cover member in this embodiment will also be described with reference to Figures 17 to 21.

In the lens device L0 of Figure 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 between the two external components, together with the cylindrical member 135, the cover member 137 can be positioned closer to the external component, preventing the intrusion of water droplets at an earlier stage. Furthermore, 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 be shaped like a cube or rectangular parallelepiped, which means that more can be used than with a doughnut shape, thereby keeping costs down.

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

In the lens device L0 shown in Figure 19, a cover member 142 is arranged 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 arranging the cover member 142 between two exterior components, the cover member 142 can be brought closer to the exterior, making it possible to prevent water droplets from entering at an earlier stage.

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 is H-shaped. This increases the contact area between the cover member 144 and each of the two members when the cover member 144 abuts against the first-group barrel 111 and the barrel member 143, thereby improving drip-proof and dust-proof performance.

In the lens device L0 of Figure 21, the method of holding the lens G1 (133), which is positioned closest to the object, has been changed. 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.

The light-shielding 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 positioned between the two exterior components, the light-shielding 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.

Next, we will describe the conditions that the lens device L0 of each embodiment preferably satisfies.

It is preferable that the lens device L0 of each embodiment satisfies at least one of the following conditional expressions (1) to (12). However, in each conditional expression, the various numerical values are expressed as follows:

Let the focal length of the first lens group L1 be fL1, and the focal length of the second lens group L2 be fL2.

Let fw be the focal length of the lens device L0 at the wide-angle end.

Let fG1 be the focal length of lens G1 located closest to the object in the first lens group L1, and fG2 be the focal length of lens G2 located adjacent to lens G1 on the image side.

Let fLF be the focal length of the focus group LF.

Let fLRw be the focal length of the rear lens unit LR at the wide-angle end of the lens device L0.

Let Skw be the back focus of lens device L0 at the wide-angle end.

Let DSPw be the distance on the optical axis from the aperture stop SP of the lens device L0 to the lens surface closest to the image.

The refractive index of the lens G1 closest to the object in the first lens unit L1 with respect to the d-line is ndG1.

Of the lens surfaces of the lens G1 closest to the object in the first lens unit L1, the radius of curvature of the object-side lens surface is R1, and the radius of curvature of the image-side lens surface is R2.

Let Yta be the maximum image height that can be photographed at the telephoto end of the lens device L0, and Ywa be the maximum image height that can be photographed at the wide-angle end.

-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)

Here, we will explain the technical meaning of the above-mentioned conditional expressions (1) to (12).

Conditional expression (1) defines the ratio between the focal length fL1 of the first lens group 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 group L1 can be appropriately positioned, thereby enabling excellent correction of distortion, lateral chromatic aberration, and field curvature. If the focal length fL1 of the first lens group L1 becomes too long below the lower limit of conditional expression (1), the first lens group L1 becomes large, making it difficult to reduce the size of the lens device L0. If the focal length fL1 of the first lens group L1 becomes too short above the upper limit of conditional expression (1), the change in image height due to coma aberration becomes large, making it difficult to correct field curvature and astigmatism.

Conditional expression (2) defines the ratio between the focal length fL2 of the second lens group L2 and the focal length fL1 of the first lens group L1. By satisfying conditional expression (2), the focal length fL1 of the first lens group L1 and the focal length fL2 of the second lens group L2 can be appropriately positioned, thereby enabling excellent correction of distortion, lateral chromatic aberration, and field curvature. If the focal length fL1 of the first lens group L1 falls below the lower limit of conditional expression (2) and becomes too short, 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 group L1 exceeds the upper limit of conditional expression (2) and becomes too long, the first lens group L1 becomes large, making it difficult to miniaturize the lens device L0.

Conditional expression (3) defines the ratio of the focal length fG1 of the lens G1 closest to the object in the first lens group L1 to the focal length fL1 of the first lens group L1. By satisfying conditional expression (3), the focal length fG1 of lens G1 can be appropriately positioned, thereby enabling excellent correction of distortion, lateral chromatic aberration, and field curvature. If the focal length fG1 of 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 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.

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. If the focal length fG1 of lens G1 becomes too short, falling below the lower limit of conditional expression (4), it becomes difficult to correct field curvature and distortion. If the focal length fG1 of lens G1 becomes too long, exceeding the upper limit of conditional expression (4), the lens G1 and first lens group L1 become large, making it difficult to reduce the size of the lens device L0.

Conditional expression (5) defines the ratio between the focal length fLF of the focus group LF and the focal length fw of the lens device 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 device L0.

Conditional expression (6) defines the ratio of the focal length fLF of the focus group LF to the focal length fL1 of the first lens group L1. If the focal length fLF of the focus group 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 group 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.

Conditional formula (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 formula (7), the converging action of the rear lens unit LR becomes large, resulting in strong 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 formula (7), it becomes difficult to correct spherical aberration and coma in the rear lens unit LR.

Conditional formula (8) defines the ratio of the back focal length Skw at the wide-angle end to the focal length fw of the lens device L0 at the wide-angle end. If the back focal length Skw falls below the lower limit of conditional formula (8) and becomes too short, it becomes difficult to place optical elements such as a low-pass filter near the image sensor that photoelectrically converts the optical image formed by the lens device L0. If the back focal length Skw exceeds the upper limit of conditional formula (8) and becomes too long, the total optical length of the lens device L0 at the wide-angle end becomes long, making it difficult to reduce size.

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 falls below the lower limit of conditional expression (9) and becomes too short, it becomes difficult to position the focus group LF. If the back focal length Skw exceeds the upper limit of conditional expression (9) and becomes too short, the total optical length of the lens device L0 at the wide-angle end becomes long, making it difficult to reduce size.

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

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 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, making it necessary to select a high-dispersion material with a small Abbe number, which makes it difficult to effectively correct distortion and chromatic aberration of magnification.

Conditional expression (11) defines the shape of the lens G1 closest to the object in the first lens group 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. Satisfying conditional expression (11) can be achieved by: 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 achieve 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 achieve a wide angle of view.

Conditional formula (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. Note that the maximum image height is 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 formula (12) and becomes too small, it becomes difficult to make the lens device L0 a wide-angle lens device that encompasses everything from circular fisheye lenses to diagonal fisheye lenses.

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.

It is preferable that the numerical ranges of 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)

Furthermore, it is more preferable that the numerical ranges of conditional expressions (1) to (12) be 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)

Next, the detailed configuration of the lens device L0 according to Examples 1 to 6 will be described. Note that explanations of overlapping configurations of the lens device L0 according to each Example will be omitted, and differences from Example 1 will be mainly described.

[Example 1]
FIG. 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.

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.

[Example 2]
3 shows a cross-sectional view of the lens apparatus L0 of Example 2. In the lens apparatus 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.

[Example 3]
5 shows a cross-sectional view of the 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.

[Example 4]
7 shows a cross-sectional view of the 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.

[Example 5]
FIG. 9 shows a cross-sectional view of a lens device L0 according to a fifth embodiment. The lens device L0 of the fifth embodiment comprises a first lens unit L1 and a rear lens unit LR. In the lens device L0 of the fifth embodiment, 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 fifth lens unit L5 is the focus unit LF.

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.

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

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

In the lens device L0 of each embodiment, it is preferable that the first lens group L1 has two or more negative lenses, in order from the object side. Furthermore, it is 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.

In the lens device L0 of each embodiment, the object-side lens surface and 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 still achieving 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.

In the lens device L0 of each embodiment, it is preferable to configure the focus group LF with two or fewer lenses and position 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.

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

The lens device L0 in each embodiment may be provided with distortion correction data for correcting distortion. This allows the lens device L0 to correct distortion that occurs in the lens optical system.

Furthermore, in the lens device L0 of each embodiment, any of the cover member placement methods shown in Figures 16 to 21 may be adopted, or the cover members may be placed using a combination of multiple placement methods.

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 given by Nd, NF, and NC, respectively, when 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 are Nd, NF, and NC, respectively.
νd=(Nd-1)/(NF-NC)
It is expressed as:

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. Note that back focus is the distance on the optical axis from the lens surface of lens device L0 closest to the image to the paraxial image plane, expressed as an air-equivalent length. The total lens length is the distance on the optical axis from the frontmost lens surface (the lens surface closest to the object) of lens device L0 to the final surface, plus the back focus. Note that the lens group in each numerical example is not limited to cases where it is composed of multiple lenses, but also includes cases where it is composed of a single lens.

Furthermore, 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×h ⁶ +A8×h ⁸ +A10×h ¹⁰ +A12×h ¹² +A14×h ¹⁴

It should be noted that "e±XX" in each aspherical coefficient represents "×10± ^XX ".

[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 plane ∞

Aspherical data No. 7
K = 0.00000e+00 A 4= 4.48181e-07 A 6= 3.99220e-08 A 8=-9.08985e-11 A10= 1.59194e-12 A12=-4.38981e-15

Page 23
K = 0.00000e+00 A 4= 6.12566e-05 A 6= 1.17826e-07 A 8= 2.22470e-09 A10=-3.70114e-11 A12= 2.37590e-13

Various data Zoom ratio 2.00
Wide Angle Mid Telephoto Focal Length 6.81 9.58 13.60
F-number 2.85 3.23 3.60
Half angle of view 58.57 57.09 57.85
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 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

[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 ∞

Aspherical data No. 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

Page 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 Telephoto Focal Length 6.80 9.52 13.41
F-number 2.86 3.22 3.61
Half angle of view 58.61 57.24 58.16
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 device 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

[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 ∞

Aspherical data No. 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

Page 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 Telephoto Focal Length 6.82 9.56 13.42
F-number 2.83 3.21 3.60
Half angle of view 58.56 57.15 58.14
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 device 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

[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 plane ∞

Aspherical data No. 13
K = 0.00000e+00 A 4= 7.64291e-06 A 6= 4.60507e-07 A 8=-1.46830e-08 A10= 3.93238e-10 A12=-3.23460e-12

Various data Zoom ratio 2.06
Wide Angle Mid Telephoto Focal Length 7.22 10.80 14.86
F-number 2.88 3.61 4.12
Half angle of view 56.10 55.97 55.46
Image height 10.75 16.00 21.60
Lens total 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 device data group Initial surface Focal length
L1 1 -16.14
L2 5 -36.44
L3 13 35.25
L4 23 46.70
L5 27 -822.66

[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 ∞

Aspherical data No. 22
K = 0.00000e+00 A 4= 2.64230e-05 A 6=-4.03358e-09 A 8= 7.40566e-10 A10=-2.79295e-11 A12= 2.33887e-13

Various data Zoom ratio 2.03
Wide Angle Mid Telephoto Focal Length 7.24 10.93 14.69
F-number 4.10 4.10 4.10
Half angle of view 56.05 55.67 55.77
Image height 10.75 16.00 21.60
Lens total 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
d11 11.80 3.96 1.33
d18 3.21 3.73 3.00
d20 3.58 3.06 3.79
d27 32.32 43.68 51.25

Lens device 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

[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 ∞

Aspherical data No. 21
K = 0.00000e+00 A 4= 3.50880e-05 A 6= 1.70964e-08 A 8= 3.91104e-09 A10=-9.58126e-11 A12= 7.92141e-13

Various data Zoom ratio 2.06
Wide Angle Mid Telephoto Focal Length 7.25 11.01 14.97
F-number 4.10 4.10 4.10
Half angle of view 56.00 55.46 55.27
Image height 10.75 16.00 21.60
Lens total 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
d12 13.54 4.41 1.90
d17 4.43 4.43 3.35
d19 1.92 1.92 3.00
d26 32.32 43.52 50.99

Lens device 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

The various values in each numerical example are summarized in Table 1 below.

[Imaging device]
Next, an image pickup apparatus using the lens device L0 of this embodiment will be described. Fig. 13 is a schematic diagram of the image pickup apparatus 10 of this embodiment. The image pickup 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.

The imaging device 10 of this embodiment has a lens device 11 that is small and has excellent optical characteristics, allowing it to capture high-quality images.

The light receiving element 12 can be an imaging element such as a CCD or CMOS sensor. In this case, various aberrations such as distortion and chromatic aberration of the image captured by the light receiving element 12 can be electrically corrected to improve the image quality of the output image.

Note that 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.

The above describes preferred embodiments and examples of the present invention, but the present invention is not limited to these embodiments and examples, and various combinations, modifications, and variations are possible within the scope of the invention.

Furthermore, the disclosure of each embodiment includes the following configurations:

(Configuration 1)
the first lens group having negative refractive power and the rear lens group including one or more lens groups, which are arranged in this order from the object side to the image side;
During zooming, the first lens group remains stationary relative to the image plane,
When zooming, the spacing between adjacent lens groups changes,
A lens apparatus that satisfies the condition ωw>85, where ωw (°) is a half angle of view when focused on infinity at the wide-angle end,
the lens device includes a first lens barrel, a light blocking member disposed closer to an object than the first lens barrel, and a cylindrical member disposed on an outer diameter side of the light blocking member,
A lens device characterized in that a cover member is provided between the light blocking member and the cylindrical member or between the first lens barrel and the cylindrical member.

(Configuration 2)
The lens device according to configuration 1, wherein the half angle of view satisfies ωw>94.

(Configuration 3)
3. The lens apparatus according to configuration 1 or 2, wherein the following conditional expression is satisfied, 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.
-3.0<fL1/fw<-1.7

(Configuration 4)
the rear group includes a second lens group having negative refractive power,
4. The lens apparatus according to any one of configurations 1 to 3, wherein 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

(Configuration 5)
5. The lens device according to any one of configurations 1 to 4, wherein the following condition is satisfied, where fG1 is the focal length of the lens G1 and fL1 is the focal length of the first lens group:
1.4<fG1/fL1<3.0

(Configuration 6)
6. A lens device according to any one of configurations 1 to 5, wherein the following conditional expression is satisfied, where fG1 is the focal length of the lens G1 and fG2 is the focal length of the lens G2 disposed adjacent to the lens G1 on the image side:
0.40<fG1/fG2<1.60

(Configuration 7)
A focus group that moves relative to the image plane during focusing,
7. The lens apparatus according to any one of configurations 1 to 6, wherein the following condition is satisfied, 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:
3.5<fLF/fw<15.0

(Configuration 8)
8. The lens apparatus according to any one of configurations 1 to 7, wherein the following condition is satisfied when the focal length of the first lens group is fL1:
-4.1<fLF/fL1<-1.8

(Configuration 9)
9. The lens apparatus according to any one of configurations 1 to 8, wherein the following conditional expression is satisfied, 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:
-1.30<fL1/fLRw<-0.55

(Configuration 10)
10. The lens device according to any one of configurations 1 to 9, wherein the following conditional expression is satisfied, 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.
2.0<Skw/fw<6.0

(Configuration 11)
11. A lens device according to any one of configurations 1 to 10, comprising an aperture stop, wherein the following conditional expression 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 device, and Skw is the back focus at the wide-angle end.
0.40<DSPw/Skw<1.00

(Configuration 12)
12. The lens device according to any one of configurations 1 to 11, wherein the following condition is satisfied when the refractive index of the material of the lens G1 with respect to the d-line is ndG1:
1.65<ndG1<2.20

(Configuration 13)
The lens device according to any one of configurations 1 to 12, wherein the lens G1 has a meniscus shape with a convex surface facing the object side, and when a radius of curvature of the object side lens surface of the lens G1 is R1 and a radius of curvature of the image side lens surface of the lens G1 is R2, the following conditional expression is satisfied:
1.3<(R1+R2)/(R1-R2)<3.0

(Configuration 14)
14. A lens apparatus according to any one of configurations 1 to 13, wherein the following conditional expression is satisfied, where Yta is the maximum image height at the telephoto end and Ywa is the maximum image height at the wide-angle end.
1.5<Yta/Ywa<3.0

(Configuration 15)
15. The lens device according to any one of configurations 1 to 14, further comprising distortion correction data for correcting distortion.

(Configuration 16)
16. The lens device according to any one of configurations 1 to 15, wherein the first lens group comprises at least two negative lenses.

(Configuration 17)
A focus group that moves relative to the image plane during focusing,
17. The lens device according to any one of configurations 1 to 16, wherein the focus group is composed of two or less lenses.

(Configuration 18)
18. The lens device according to any one of configurations 1 to 17, wherein the lens surfaces of the lenses included in the first lens group are spherical.

(Configuration 19)
19. The lens apparatus according to any one of configurations 1 to 18, wherein the rear group comprises three or more lens groups.

(Configuration 20)
19. A lens device according to any one of configurations 1 to 19, wherein 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 side than the first lens barrel.

(Configuration 21)
an aperture stop and a focus group that moves relative to an image plane during focusing;
21. The lens apparatus according to any one of configurations 1 to 20, wherein the focus group is disposed closer to the image side than the aperture stop.

(Configuration 22)
The lens device described in any one of configurations 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.

(Configuration 23)
The lens device described in any one of configurations 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.

(Configuration 24)
the first lens group abuts against the first lens barrel,
24. The lens device according to any one of configurations 1 to 23, wherein the cylindrical member is located closer to the image plane than the object-side end of the light blocking member.

(Configuration 25)
25. The lens device according to any one of configurations 1 to 24, wherein the first lens group abuts against the light blocking member.

(Configuration 26)
The lens device according to any one of configurations 1 to 25, wherein the cover members are provided between the light blocking member and the cylindrical member, and between the first lens barrel and the cylindrical member.

(Configuration 27)
27. An imaging device comprising: the lens device according to any one of configurations 1 to 26; and an imaging element that receives an image formed by the lens device.

L0 Lens device L1 First lens group LR Rear group 111 First first group barrel 133 Lens G1
134 First light blocking member 135 First cylindrical member 136 First cover member

Claims (27)

the first lens group having negative refractive power and the rear lens group including one or more lens groups, which are arranged in this order from the object side to the image side;
During zooming, the first lens group remains stationary relative to the image plane,
When zooming, the spacing between adjacent lens groups changes,
A lens apparatus that satisfies the condition ωw>85, where ωw (°) is a half angle of view when focused on infinity at the wide-angle end,
the lens device includes a first lens barrel, a light blocking member disposed closer to an object than the first lens barrel, and a cylindrical member disposed on an outer diameter side of the light blocking member,
A lens device characterized in that a cover member is provided between the light blocking member and the cylindrical member or between the first lens barrel and the cylindrical member. The lens device described in claim 1, characterized in that the half angle of view satisfies ωw > 94. 2. The lens apparatus according to claim 1, wherein the following condition is satisfied, 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.
-3.0<fL1/fw<-1.7 the rear group includes a second lens group having negative refractive power,
2. The lens apparatus according to claim 1, wherein 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 2. The lens apparatus according to claim 1, wherein the following conditional expression is satisfied, where fG1 is the focal length of the lens G1 arranged closest to the object in the first lens group, and fL1 is the focal length of the first lens group:
1.4<fG1/fL1<3.0 2. The lens apparatus according to claim 1, wherein the following conditional expression is satisfied: 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.
0.40<fG1/fG2<1.60 A focus group that moves relative to the image plane during focusing,
2. The lens apparatus according to claim 1, wherein the following condition is satisfied, 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:
3.5<fLF/fw<15.0 8. The lens apparatus according to claim 7, wherein the following condition is satisfied, where fL1 is the focal length of the first lens group:
-4.1<fLF/fL1<-1.8 2. The lens apparatus according to claim 1, wherein the following condition is satisfied, 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.
-1.30<fL1/fLRw<-0.55 2. The lens device according to claim 1, wherein the following condition is satisfied, where Skw is a back focus at the wide-angle end and fw is a focal length of the lens device at the wide-angle end:
2.0<Skw/fw<6.0 2. The lens apparatus according to claim 1, further comprising an aperture stop, wherein the following conditional expression 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 2. The lens apparatus according to claim 1, wherein the refractive index of the material of the lens G1 arranged closest to the object side in the first lens group is ndG1, and the following conditional expression is satisfied:
1.65<ndG1<2.20 2. The lens apparatus according to claim 1, wherein 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 conditional expression is satisfied when the radius of curvature of the object-side lens surface of the lens G1 is R1 and the radius of curvature of the image-side lens surface of the lens G1 is R2:
1.3<(R1+R2)/(R1-R2)<3.0 2. The lens device according to claim 1, wherein the following condition is satisfied, where Yta is the maximum image height at the telephoto end and Ywa is the maximum image height at the wide-angle end.
1.5<Yta/Ywa<3.0 The lens device described in claim 1, characterized in that it is provided with distortion correction data for correcting distortion aberration. The lens device of claim 1, wherein the first lens group consists of at least two negative lenses. A focus group that moves relative to the image plane during focusing,
2. The lens device according to claim 1, wherein the focus group is composed of two or less lenses. The lens device described in claim 1, characterized in that the lens surfaces of the lenses included in the first lens group are spherical. The lens device of claim 1, wherein the rear group consists of three or more lens groups. The lens device described in claim 1, 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 lens G1 is located closer to the object side than the first lens barrel. an aperture stop and a focus group that moves relative to an image plane during focusing;
2. The lens apparatus according to claim 1, wherein the focus group is disposed closer to the image side than the aperture stop. The lens device according to claim 1, wherein 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. The lens device according to claim 1, wherein 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. the first lens group abuts against the first lens barrel,
2. The lens device according to claim 1, wherein the cylindrical member is located closer to the image plane than the object-side end of the light-shielding member. The lens device described in claim 24, wherein the first lens group abuts against the light-blocking member. The lens device described in claim 1, 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. 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.