JP2022160964A - Lens system, image capturing device, and mobile body - Google Patents

Abstract

To provide a lens system which is a telephoto lens and yet has a short total length, and allows for reducing the size of a lens barrel.SOLUTION: A lens system 100 is provided, comprising a positive first lens group G1 and a negative second lens group G2 in order from the object side. The first lens group comprises a first lens L1 with positive refractive power having a convex surface on the object side, a second lens L2 with negative refractive power having a concave surface on the image side, a third lens L3 with positive refractive power, and a fourth lens L4 having a convex surface on the object side. The second lens group comprises a fifth lens L5 with positive refractive power and a sixth lens L6 with negative refractive power. The first lens group moves toward the object side when shifting focus from infinity to a nearby object. The lens system satisfies predetermined conditional expressions.SELECTED DRAWING: Figure 1

Description

The present invention relates to a lens system, an imaging device, and a moving object.

As a lens system that can be used in an imaging device, Patent Document 1 discloses a six-lens system. Patent Document 2 discloses a lens system having a five-lens structure and a half angle of view of about 9 degrees.
[Prior art documents]
[Patent Literature]
[Patent Document 1] Japanese Patent No. 6534162 [Patent Document 2] Japanese Unexamined Patent Publication No. 2020-122829

A lens system according to an aspect of the present invention includes, in order from the object side, a positive first lens group and a negative second lens group. The first lens group includes a first lens having a positive refractive power with a convex surface facing the object side. The first lens group includes a second lens having a concave surface facing the image side and having negative refractive power. The first lens group comprises a third lens with positive refractive power. The first lens group includes a fourth lens having a convex surface facing the object side. The second lens group comprises a fifth lens with positive refractive power. The second lens group includes a sixth lens having negative refractive power. During focusing from infinity to a short-distance subject, the first lens group moves toward the object side. f1g is the focal length of the first lens group, f is the focal length of the entire lens system, v13 is the average Abbe number of the first lens at the d-line and that of the third lens at the d-line, and Imgh is the diagonal image height. , the conditional expression 0.65 < f1g/f < 1.2
v13 > 60
f/Imgh > 8
satisfy.

Assuming that the focal length of the first lens is f1, the conditional expression 0.5<f1/f<0.9
may be satisfied.

The fourth lens may have a convex surface facing the object side, and at least one surface may be aspheric. Assuming that the focal length of the fourth lens is f4, the conditional expression |f4/f|>1
may be satisfied.

The lens system may include a reflecting member for bending the optical path between the fourth lens and the fifth lens. The conditional expression D45/Imgh>3 where D45 is the air gap between the fourth lens and the fifth lens, D1g is the axial distance of the first lens group, and TTL is the total optical length.
D1g/TTL <0.37
may be satisfied.

The conditional expression 0.8<TTL/f<1.2 where TTL is the total optical length
may be satisfied.

An imaging device according to an aspect of the present invention includes the above lens system. The imaging device has an image sensor.

A moving object according to an aspect of the present invention moves with the lens system described above.

The mobile object may be an unmanned aerial vehicle.

According to the above lens system, it is possible to provide a lens system having a short overall length while being a telephoto lens. Also, it is possible to provide a lens system capable of reducing the size of the lens barrel.

It should be noted that the above summary of the invention does not list all the necessary features of the invention. Subcombinations of these feature groups can also be inventions.

The lens configuration of the lens system 100 in Example 1 is shown together with an optical member P and an image plane IM. 4 shows the spherical aberration, astigmatism, and distortion of lens system 100 when focused on an object at infinity. The lens configuration of the lens system 200 in Example 2 is shown together with the optical member P and the image plane IM. 4 shows the spherical aberration, astigmatism, and distortion of lens system 200 when focused on an object at infinity. The lens configuration of the lens system 300 in Example 3 is shown together with the optical member P and the image plane IM. The spherical aberration, astigmatism, and distortion of the lens system 300 when focused on an infinite object are shown. The lens configuration of the lens system 400 in Example 4 is shown together with the optical member P and the image plane IM. 4 shows the spherical aberration, astigmatism, and distortion of lens system 400 when focused on an object at infinity. An example of an external perspective view of an imaging device 2000 including the lens system according to the present embodiment is shown. 2 is a diagram showing functional blocks of an imaging device 2000; FIG. 1 schematically illustrates an example mobile system 10 comprising an unmanned aerial vehicle (UAV) 40 and a controller 50. FIG. FIG. 3 is an external perspective view showing an example of a stabilizer 3000;

Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. Also, not all combinations of features described in the embodiments are essential for the solution of the invention. It is obvious to those skilled in the art that various modifications and improvements can be made to the following embodiments. It is clear from the description of the scope of claims that forms with such modifications or improvements can also be included in the technical scope of the present invention.

The claims, specification, drawings, and abstract contain material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by any person of these documents as they appear in the Patent Office files or records. However, otherwise, all copyrights are reserved.

Examples of lens systems are disclosed in connection with FIGS. 1-12. As disclosed in each example, the lens system of one embodiment comprises, in order from the object side, a positive first lens group and a negative second lens group. The first lens group includes a first lens having positive refractive power with a convex surface facing the object side, a second lens having negative refractive power with a concave surface facing the image side, and a third lens having positive refractive power. A lens and a fourth lens having a convex surface facing the object side. The second lens group includes a fifth lens with positive refractive power and a sixth lens with negative refractive power. During focusing from infinity to a short-distance object, the first lens group moves toward the object side. In the lens system, the focal length of the first lens group is f1g, the focal length of the entire lens system is f, the average Abbe number of the first lens at the d-line and the Abbe number of the third lens at the d-line is v13, and the diagonal Imgh being the image height, conditional expression 0.65<f1g/f<1.2 (1)
v13>60 (2)
f/Imgh > 8 (3)
satisfy.

Conditional expression (1) defines the relationship between the focal length of the first lens group and the focal length of the entire lens system. Below the lower limit of conditional expression (1), the refracting power of the first group becomes strong, making it difficult to correct axial aberrations in particular, and deteriorating performance due to eccentricity errors. On the other hand, when the upper limit of conditional expression (1) is exceeded, the refracting power of the first group becomes too weak, resulting in a large amount of movement during focusing from infinity to a short-distance object.

Conditional expression (2) defines the average value of the Abbe numbers of the first lens and the third lens. Abbe numbers of the first lens and the third lens, which bear the positive refractive power of the first lens group, satisfy conditional expression (2), so that chromatic aberration can be satisfactorily suppressed even in a telephoto lens where chromatic aberration tends to be a problem. can be done.

Conditional expression (3) defines the relationship between the focal length of the entire system and the image height. By satisfying conditional expression (3), it is possible to realize a telephoto lens with a 35 mm equivalent focal length exceeding 160 mm.

In the lens system of one embodiment, where f1 is the focal length of the first lens, conditional expression 0.5<f1/f<0.9 (4)
satisfy.

Conditional expression (4) defines the relationship between the focal length of the first lens and the focal length of the entire lens system. If the lower limit of conditional expression (4) is exceeded, the refractive power of the first lens increases, and the amount of spherical aberration generated on each surface increases, making aberration correction difficult. On the other hand, when the upper limit of conditional expression (4) is exceeded, the refractive power of the first lens becomes weak, making it difficult to shorten the total length.

The fourth lens has a convex surface facing the object side and has at least one aspherical surface. In the lens system of one embodiment, the focal length of the fourth lens is f4, and the conditional expression |f4/f|>1 (5)
satisfy.

Conditional expression (5) defines the relationship between the focal length of the fourth lens and the focal length of the entire lens system. To correct spherical aberration in a telephoto lens system, correction by an aspherical surface is effective at a position where the effective ray height of axial rays is high. On the other hand, the deterioration of on-axis performance due to the shape error of the aspheric surface also increases. By making at least one surface of the fourth lens an aspherical surface, it is possible to effectively correct spherical aberration while suppressing degradation of on-axis performance due to shape errors of the aspherical surface. Moreover, by satisfying the conditional expression (5), the eccentricity error sensitivity can also be reduced.

A lens system of one embodiment includes a reflecting member for bending an optical path between the fourth lens and the fifth lens. In the lens system of one embodiment, where D45 is the air gap between the fourth lens and the fifth lens, D1g is the axial distance of the first lens group, and TTL is the optical total length TTL, the conditional expression D45/Imgh>3 (6)
D1g/TTL <0.37 (7)
satisfy.

Conditional expression (6) defines the relationship between the air gap between the fourth lens and the fifth lens and the image height. By ensuring a sufficiently wide air gap with respect to the image height, it is possible to arrange a reflecting member for bending the optical path, and it is possible to bend the light and reduce the size of the lens barrel.

Conditional expression (7) defines the relationship between the axial distance and the overall length of the first lens group. When the axial distance of the first lens group, which is a movable group, satisfies conditional expression (7), the size in the depth direction can be suppressed even when the optical path is bent.

In the lens system of one embodiment, conditional expression 0.8<TTL/f<1.2 (8)
satisfy.

Conditional expression (8) defines the relationship between the total optical length and the focal length. By satisfying the conditional expression (8), it is possible to realize a compact optical system in which aberrations are satisfactorily corrected.

According to the above lens system, it is possible to provide a lens system having a short overall length while being a telephoto lens. Also, it is possible to provide a lens system capable of reducing the size of the lens barrel.

In this specification and the like, when the terms "consisting of", "consisting of", and "consisting of" are used, in addition to the listed constituent elements, it has substantially no refractive power It may include optical elements other than lenses that have substantially refractive power, such as lenses, diaphragms, filters, and cover glasses, and/or mechanical elements, such as lens flanges, image sensors, and shake correction mechanisms. For example, when the terms “consisting of X,” “consisting of X,” “consisting of” are used, in addition to X, optical elements and/or features other than lenses that have substantially refractive power can contain elements.

Next, an example in which specific numerical values are applied to specific embodiments of the lens system will be described. First, the meanings of the symbols used in the description of each embodiment of the lens system will be described.

As lens data, a table showing surface numbers, radii of curvature, surface spacings, refractive indices, and Abbe numbers is disclosed. In the lens data table, the surface number column indicates the surface number when the surface closest to the object side is the first surface and the number is incremented one by one toward the image side. The R column shows the radius of curvature of each surface. Column D shows the distance between each surface and its image-side adjacent surface on the optical axis. The Nd column shows the refractive index for the d-line (wavelength 587.6 nm (nanometers)) of each optical element. The νd column shows the d-line reference Abbe number of each optical element. Here, the sign of the radius of curvature is positive when the surface shape is convex toward the object side, and negative when the surface shape is convex toward the image plane side. "INF" in the radius of curvature indicates that the surface is planar.

The lens data also include the aperture stop S. “STO” in the surface number column represents the aperture surface of the aperture stop S. FIG. "mirror" in the surface number column represents the reflecting surface of the mirror M that bends the optical path.

In the lens data, the surface number of the aspherical surface is marked with *, and the paraxial radius of curvature is shown in the column of radius of curvature. Also, for examples of lens systems having aspheric surfaces, a table of aspheric surface data including the surface numbers of the aspheric surfaces, the aspheric coefficients for each aspheric surface, and the conic constant is provided. In the table of the aspherical surface data, "E±n" (n: natural number) of the numerical value of the aspherical surface coefficient represents a base 10 exponential expression. That is, "E±n" represents "×10 ^±n ". For example, “0.12345E-05” represents “0.12345×10 ⁻⁵ ”. For the aspherical shape, "zd" is the distance (sag amount) in the optical axis direction from the vertex of the lens surface, "h" is the distance (height) in the direction perpendicular to the optical axis direction, and "c" is the vertex of the lens. is the paraxial curvature (reciprocal of the radius of curvature), "κ" is the conic constant (conic constant), and "Am" is the m-th order aspheric coefficient.
zd=ch ² /(1+(1−(1+κ)c ² h ² ) ^1/2 )+ΣAm×h ^m
Note that Σ indicates the sum of m.

Also, a table of specification data of the lens system of each example is attached. In the table of specification data, "f" indicates focal length. "Fno" indicates the F number. “ω” indicates a half angle of view (maximum half angle of view). "ImgH" indicates the maximum image height. "TTL" indicates the total optical length when focusing on an object at infinity.

In tables of lens data and lens system specification data, "degree" is used as the unit of angle, and "mm" is used as the unit of length. However, since the lens system can be used in proportional enlargement or reduction, any other units may be used.

When the lens system is installed as an imaging lens in an imaging apparatus, it is preferable to include various filters such as a low-pass filter and optical elements such as a protective cover glass according to the specifications of the imaging apparatus. As the lens system of the present embodiment, it is possible to adopt a form having such an optical element or a form not having such an optical element. A lens system having such an optical element and a lens system having no optical element can be said to be equivalent lens systems.

"Lj" indicates one lens. The j following the letter L in "Lj" is a natural number intended to identify the lens included in the lens system in each embodiment. In the description of each embodiment, it does not mean that the lens assigned the symbol Lj and the lens assigned the same symbol Lj in other embodiments are the same lens.

The lens system of each embodiment has the following common basic configuration. The lens system of each embodiment includes, in order from the object side, a first lens having positive refractive power, a second lens having negative refractive power, a third lens having positive refractive power, a fourth lens, and a positive third lens. It consists of 6 lenses, 5 lenses and a negative 6th lens. The first lens has a convex surface facing the object side in the vicinity of the optical axis. The second lens has a concave surface facing the image side in the vicinity of the optical axis. The third lens has a convex surface facing the object side and a concave surface facing the image side in the vicinity of the optical axis. The shape of the fourth lens in the vicinity of the optical axis has a convex surface facing the object side and a concave surface facing the image side. The fifth lens has a convex surface facing the object side and a convex surface facing the image side in the vicinity of the optical axis. The sixth lens has a concave surface facing the object side and a convex surface facing the image side in the vicinity of the optical axis.

FIG. 1 shows the lens configuration of a lens system 100 in Example 1 together with an optical member P and an image plane IM.

The lens system 100 is composed of an aperture stop S, a cemented lens of a first lens L1 and a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6. be. The first lens L1 has positive refractive power. The second lens L2 has negative refractive power. The third lens L3 has positive refractive power. The fourth lens L4 has positive refractive power. The fifth lens L5 has positive refractive power. The sixth lens L6 has negative refractive power. The lens system 100 comprises, in order from the object side, an aperture diaphragm S, a cemented lens composed of a first lens L1 and a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6. be done.

Table 1 shows lens data for lens system 100 . Table 2 is a table showing the aspheric surface data of lens system 100 .

Table 3 shows the focal length f, F-number Fno, half angle of view ω, image height ImgH, and total optical length TTL of the lens system 100 when focusing on an infinite object. It is a table of original data.

FIG. 2 shows the spherical aberration, astigmatism, and distortion of lens system 100 when focused on an infinite object. Regarding spherical aberration, the dashed-dotted line indicates the value for the C-line (656.27 nm), the solid line indicates the value for the d-line (587.56 nm), and the dashed line indicates the value for the g-line (435.84 nm). Regarding astigmatism, the solid line indicates the value of the d-line sagittal image plane, and the dashed line indicates the value of the d-line meridional image plane. As for distortion aberration, the value of the d-line is shown. From the aberration diagrams, it is clear that the lens system 100 is well corrected for various aberrations and has excellent imaging performance.

FIG. 3 shows the lens configuration of the lens system 200 in Example 2 together with the optical member P and the image plane IM.

The lens system 200 is composed of a cemented lens of a first lens L1 and a second lens L2, an aperture diaphragm S, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6. . The first lens L1 has positive refractive power. The second lens L2 has negative refractive power. The third lens L3 has positive refractive power. The fourth lens L4 has negative refractive power. The fifth lens L5 has positive refractive power. The sixth lens L6 has negative refractive power. The lens system 100 is composed of, in order from the object side, a cemented lens of a first lens L1 and a second lens L2, an aperture stop S, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6. be.

Table 4 shows lens data for lens system 200 . Table 5 is a table showing the aspheric surface data of lens system 200 .

Table 6 shows the focal length f, F-number Fno, half angle of view ω, image height ImgH, and total optical length TTL of the lens system 200 when focusing on an infinite object. It is a table of original data.

FIG. 4 shows the spherical aberration, astigmatism, and distortion of lens system 200 when focused on an infinite object. Regarding spherical aberration, the dashed-dotted line indicates the value for the C-line (656.27 nm), the solid line indicates the value for the d-line (587.56 nm), and the dashed line indicates the value for the g-line (435.84 nm). Regarding astigmatism, the solid line indicates the value of the d-line sagittal image plane, and the dashed line indicates the value of the d-line meridional image plane. As for distortion aberration, the value of the d-line is shown. From the aberration diagrams, it is clear that the lens system 200 is well corrected for various aberrations and has excellent imaging performance.

FIG. 5 shows the lens configuration of the lens system 300 in Example 3 together with the optical member P and the image plane IM.

The lens system 300 is composed of an aperture diaphragm S, a cemented lens of a first lens L1 and a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6. be. The first lens L1 has positive refractive power. The second lens L2 has negative refractive power. The third lens L3 has positive refractive power. The fourth lens L4 has negative refractive power. The fifth lens L5 has positive refractive power. The sixth lens L6 has negative refractive power. The lens system 300 is composed of, in order from the object side, an aperture diaphragm S, a cemented lens of a first lens L1 and a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6. be.

Table 7 shows lens data for lens system 300 . Table 8 is a table showing aspheric surface data for lens system 300 .

Table 9 shows the focal length f, F-number Fno, half angle of view ω, image height ImgH, and total optical length TTL of the lens system 300 when focused on an infinite object. It is a table of original data.

FIG. 6 shows the spherical aberration, astigmatism, and distortion of lens system 300 when focused on an object at infinity. Regarding spherical aberration, the dashed-dotted line indicates the value for the C-line (656.27 nm), the solid line indicates the value for the d-line (587.56 nm), and the dashed line indicates the value for the g-line (435.84 nm). Regarding astigmatism, the solid line indicates the value of the d-line sagittal image plane, and the dashed line indicates the value of the d-line meridional image plane. As for distortion aberration, the value of the d-line is shown. From the aberration diagrams, it is clear that the lens system 300 is well corrected for various aberrations and has excellent imaging performance.

FIG. 7 shows the lens configuration of the lens system 400 in Example 4 together with the optical member P and the image plane IM.

The lens system 400 includes a first lens L1, a second lens L2, a third lens L3, an aperture stop S, a fourth lens L4, a mirror M, a fifth lens L5, and a sixth lens L6. Configured. The first lens L1 has positive refractive power. The second lens L2 has negative refractive power. The third lens L3 has positive refractive power. The fourth lens L4 has negative refractive power. The mirror M is an example of a reflecting member that bends the optical path. The fifth lens L5 has positive refractive power. The sixth lens L6 has negative refractive power. The lens system 100 includes, in order from the object side, a first lens L1, a second lens L2, a third lens L3, an aperture stop S, a fourth lens L4, a mirror M, a fifth lens L5, and a sixth lens L6. be.

Table 10 shows lens data for lens system 400 . Table 11 is a table showing aspheric surface data for lens system 400 .

Table 12 shows the focal length f, F-number Fno, half angle of view ω, image height ImgH, and total optical length TTL of the lens system 400 when focusing on an infinite object. It is a table of original data.

FIG. 8 shows the spherical aberration, astigmatism, and distortion of lens system 400 when focused on an object at infinity. Regarding spherical aberration, the dashed-dotted line indicates the value for the C-line (656.27 nm), the solid line indicates the value for the d-line (587.56 nm), and the dashed line indicates the value for the g-line (435.84 nm). Regarding astigmatism, the solid line indicates the value of the d-line sagittal image plane, and the dashed line indicates the value of the d-line meridional image plane. As for distortion aberration, the value of the d-line is shown. From the aberration diagrams, it is clear that the lens system 400 is well corrected for various aberrations and has excellent imaging performance.

Table 13 shows numerical values calculated by each of conditional expressions (1) to (8) in the lens systems of Examples 1 to 4. Table 14 shows numerical values of variables used in conditional expressions (1) to (8) in the lens systems of Examples 1 to 4.

As described above, according to the lens configuration of the lens system of the above embodiment, it is possible to provide a lens system having a narrow angle of view with a half angle of view smaller than 6 degrees. Further, according to the lens configuration of the lens system of the above embodiment, it is possible to provide a compact and high-performance lens system.

Arbitrary combinations of the configurations provided in the above-described lens system are possible, and they can be selectively employed as appropriate according to required specifications. For example, although the lens system according to the above embodiment satisfies the conditional expressions (1) to (8), it may satisfy any one of the conditional expressions (1) to (8). Any combination of these conditional expressions may be satisfied.

Although the present invention has been described above with reference to the embodiments and examples, the present invention is not limited to the above-described embodiments and examples, and various modifications are possible. For example, the radius of curvature, surface spacing, refractive index, and Abbe number of each lens are not limited to the values shown in the above embodiments, and may take other values.

2. Description of the Related Art In recent years, the number of pixels in an image sensor has increased, and a higher resolution is required for a lens system. Also, a compact lens system is required. It is also required to enlarge and shoot a distant subject. There is a demand for a telephoto lens with a short overall length and a small barrel size. On the other hand, the lens system described in Patent Document 2 has a half angle of view of about 18 degrees, and the configuration of the lens system described in Patent Document 2 has a problem in realizing an even narrower angle of view. Further, in the lens system configuration described in Patent Document 2, there is a problem in realizing a narrower angle of view and higher resolution. On the other hand, according to the lens system according to the above embodiment, such problems can be alleviated.

The lens system according to the present embodiment can be applied to lens systems for imaging devices such as digital still cameras and video cameras. The lens system according to this embodiment can be applied to a lens system that does not have a zoom mechanism. The lens system according to this embodiment can be applied to lens systems such as an aerial camera and a surveillance camera. The lens system according to this embodiment can be applied to an imaging lens included in a non-interchangeable lens type imaging apparatus. The lens system according to this embodiment can be applied to an interchangeable lens of an interchangeable lens type camera such as a single-lens reflex camera. The lens system according to this embodiment can be applied to an imaging device of a mobile phone or a personal digital assistant having an imaging function.

FIG. 9 shows an example of an external perspective view of an imaging device 2000 that includes the lens system according to this embodiment. FIG. 10 is a diagram showing functional blocks of the imaging device 2000. As shown in FIG.

The imaging device 2000 includes an imaging section 2100 and a lens section 2200 . The imaging unit 2100 has an image sensor 2120 , a control unit 2110 , a memory 2130 , an instruction unit 2162 , a display unit 2160 and a communication unit 2170 .

Image sensor 2120 may be configured with a CCD or CMOS. The image sensor 2120 receives light via an imaging lens system 2210 included in the lens section 2200 . Image sensor 2120 outputs image data of an optical image formed via imaging lens system 2210 to control unit 2110 . The imaging lens system 2210 includes the lens system according to the embodiment described above, and forms an optical image of a subject on the image sensor 2120 .

The control unit 2110 may be configured by a microprocessor such as a CPU or MPU, a microcontroller such as an MCU, or the like. The memory 2130 may be a computer-readable recording medium and may include at least one of SRAM, DRAM, EPROM, EEPROM, and flash memory such as USB memory. A control unit 2110 corresponds to the circuit. The memory 2130 stores programs and the like necessary for the control unit 2110 to control the image sensor 2120 and the like. The memory 2130 may be provided inside the housing of the imaging device 2000 . The memory 2130 may be provided detachably from the housing of the imaging device 2000 .

The instruction unit 2162 is a user interface that receives an instruction to the imaging device 2000 from the user. A display unit 2160 displays an image captured by the image sensor 2120 and processed by the control unit 2110, various setting information of the imaging device 2000, and the like. The display unit 2160 may be configured with a touch panel.

A control unit 2110 controls the image sensor 2120 . The control unit 2110 outputs a control command to the image sensor 2120 based on the information indicating the user's instruction acquired through the instruction unit 2162 or the like, thereby executing control including control of the imaging operation of the image sensor 2120 . Control unit 2110 acquires an image captured by image sensor 2120 . The control unit 2110 performs image processing on the image acquired from the image sensor 2120 and stores the processed image in the memory 2130 .

The communication unit 2170 is in charge of communication with the outside. Communication unit 2170 transmits the information generated by control unit 2110 to the outside through a communication network. The communication unit 2170 provides the control unit 2110 with information received from the outside through the communication network.

Next, an embodiment of a moving body system including a moving body having the lens system according to this embodiment will be described.

FIG. 11 schematically illustrates an example mobile system 10 comprising an unmanned aerial vehicle (UAV) 40 and a controller 50 . The UAV 40 includes a UAV main body 1101 , a gimbal 1110 , a plurality of imaging devices 1230 and an imaging device 1220 . The imaging device 1220 includes a lens device 1160 and an imaging section 1140 . Lens device 1160 comprises the lens system described above. The UAV 40 is an example of a moving body equipped with an imaging device having the lens system described above. The moving object is a concept that includes not only UAVs but also other aircraft that move in the air, vehicles that move on the ground, ships that move on water, and the like.

UAV body 1101 comprises a plurality of rotor blades. The UAV body 1101 causes the UAV 40 to fly by controlling the rotation of multiple rotor blades. The UAV main body 1101 uses, for example, four rotor blades to fly the UAV 40 . The number of rotor blades is not limited to four. UAV 40 may be a fixed wing aircraft without rotary wings.

The imaging device 1230 is an imaging camera that captures an image of a subject included in a desired imaging range. The multiple imaging devices 1230 are cameras for sensing that capture images of the surroundings of the UAV 40 in order to control the flight of the UAV 40 . The imaging device 1230 may be fixed to the UAV body 1101 . The imaging lens system included in the imaging device 1230 may include the lens system described above.

Two imaging devices 1230 may be provided at the nose front of the UAV 40 . Two more imaging devices 1230 may be provided on the underside of UAV 40 . The two imaging devices 1230 on the front side may be paired and function as a so-called stereo camera. The two imaging devices 1230 on the bottom side may also be paired and function as a stereo camera. Three-dimensional spatial data around the UAV 40 may be generated based on the images captured by the plurality of imaging devices 1230 . The distance to the subject imaged by the plurality of imaging devices 1230 can be specified by the stereo cameras of the plurality of imaging devices 1230 .

The number of imaging devices 1230 provided in the UAV 40 is not limited to four. UAV 40 may include at least one imaging device 1230 . UAV 40 may include at least one imaging device 1230 on each of the nose, tail, sides, bottom, and ceiling of UAV 40 . In the description of the UAV 40 , the plurality of imaging devices 1230 may simply be collectively referred to as the imaging device 1230 .

The controller 50 has a display section 54 and an operation section 52 . The operation unit 52 receives an input operation for controlling the attitude of the UAV 40 from the user. The controller 50 transmits a signal for controlling the UAV 40 based on the user's operation received by the operation unit 52 .

The controller 50 receives images captured by at least one of the imaging device 1230 and the imaging device 1220 . The display unit 54 displays the image received by the controller 50 . The display unit 54 may be a touch panel. The controller 50 may receive an input operation from the user through the display section 54 . The display unit 54 may accept a user operation or the like for specifying the position of a subject to be imaged by the imaging device 1220 .

The imaging unit 1140 generates and records image data of an optical image formed by the lens device 1160 . The lens device 1160 may be provided integrally with the imaging section 1140 . The lens device 1160 may be a so-called interchangeable lens. The lens device 1160 may be provided detachably with respect to the imaging section 1140 . Lens arrangement 1160 may comprise the lens system described above.

The gimbal 1110 has a support mechanism that movably supports the imaging device 1220 . The imaging device 1220 is attached to the UAV main body 1101 via the gimbal 1110 . The gimbal 1110 supports the imaging device 1220 rotatably around the pitch axis. The gimbal 1110 supports the imaging device 1220 rotatably around the roll axis. The gimbal 1110 supports the imaging device 1220 rotatably around the yaw axis. The gimbal 1110 may rotatably support the imaging device 1220 about at least one of the pitch, roll, and yaw axes. The gimbal 1110 may rotatably support the imaging device 1220 about each of the pitch axis, roll axis, and yaw axis. The gimbal 1110 may hold the imaging section 1140 . Gimbal 1110 may hold a lens arrangement 1160 . The gimbal 1110 may change the imaging direction of the imaging device 1220 by rotating the imaging section 1140 and the lens device 1160 about at least one of the yaw axis, pitch axis, and roll axis.

Next, a stabilizer will be described as an example of a system including the lens systems according to the above embodiments and examples.

FIG. 12 is an external perspective view showing an example of the stabilizer 3000. FIG. Stabilizer 3000 is another example of a moving body. For example, the camera unit 3013 included in the stabilizer 3000 may include an imaging device having a configuration similar to that of the imaging device 1220 . The camera unit 3013 may include a lens device having a configuration similar to that of the lens device 1160 .

Stabilizer 3000 includes camera unit 3013 , gimbal 3020 and handle 3003 . Gimbal 3020 rotatably supports camera unit 3013 . Gimbal 3020 has pan axis 3009 , roll axis 3010 and tilt axis 3011 . A gimbal 3020 rotatably supports a camera unit 3013 around a pan axis 3009 , a roll axis 3010 and a tilt axis 3011 . Gimbal 3020 is an example of a support mechanism.

The camera unit 3013 is an example of an imaging device. Camera unit 3013 has a slot 3014 for inserting memory. A gimbal 3020 is fixed to the handle portion 3003 via a holder 3007 .

A handle portion 3003 has various buttons for operating the gimbal 3020 and the camera unit 3013 . A handle portion 3003 includes a shutter button 3004 , a recording button 3005 and an operation button 3006 . A still image can be recorded by the camera unit 3013 by pressing the shutter button 3004 . A moving image can be recorded by the camera unit 3013 by pressing the record button 3005 .

A device holder 3001 is fixed to a handle portion 3003 . A device holder 3001 holds a mobile device 3002 such as a smart phone. Mobile device 3002 is communicatively connected to stabilizer 3000 via a wireless network such as WiFi. Accordingly, an image captured by the camera unit 3013 can be displayed on the screen of the mobile device 3002 .

Also in the stabilizer 3000, the camera unit 3013 may include the lens system according to the above embodiments.

In the above, the UAV 40 and the stabilizer 3000 have been taken up and explained as an example of the moving object. An imaging device having a configuration similar to that of the imaging device 1220 may be attached to a moving object other than the UAV 40 and the stabilizer 3000 .

Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It is obvious to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the description of the scope of claims that forms with such modifications or improvements can also be included in the technical scope of the present invention.

The execution order of each process such as actions, procedures, steps, and stages in the devices, systems, programs, and methods shown in the claims, the specification, and the drawings is etc., and it should be noted that they can be implemented in any order unless the output of the previous process is used in the subsequent process. Regarding the operation flow in the claims, the specification, and the drawings, even if the description is made using “first,” “next,” etc. for convenience, it means that it is essential to carry out in this order. not a thing

100, 200, 300, 400 lens system, 2000 imaging device, 2100 imaging unit, 2110 control unit, 2120 image sensor, 2130 memory, 2160 display unit, 2162 instruction unit, 2170 communication unit, 2200 lens unit, 2210 imaging lens system, 10 Mobile System 40 UAV 50 Controller 52 Operation Unit 54 Display Unit 1101 UAV Body 1110 Gimbal 1140 Imaging Unit 1160 Lens Device 1220, 1230 Imaging Device 3000 Stabilizer 3001 Device Holder 3002 Mobile Device , 3003 handle, 3004 shutter button, 3005 recording button, 3006 operation button, 3007 holder, 3009 pan axis, 3010 roll axis, 3011 tilt axis, 3013 camera unit, 3014 slot, 3020 gimbal

Claims (8)

a lens system,
A positive first lens group and a negative second lens group are provided in order from the object side,
The first lens group is
a first lens having positive refractive power with a convex surface facing the object side;
a second lens having a concave surface facing the image side and having negative refractive power;
a third lens having positive refractive power;
a fourth lens with a convex surface facing the object side;
The second lens group is
a fifth lens having positive refractive power;
and a sixth lens having negative refractive power,
When focusing from infinity to a short-distance subject, the first lens group moves toward the object side,
The focal length of the first lens group is f1g, the focal length of the entire lens system is f, the average value of the Abbe number of the first lens at the d-line and the Abbe number of the third lens at the d-line is v13, and the diagonal image height is as Imgh, the conditional expression 0.65 < f1g/f < 1.2
v13 > 60
f/Imgh > 8
lens system that satisfies Assuming that the focal length of the first lens is f1, the conditional expression 0.5<f1/f<0.9
2. The lens system according to claim 1, wherein: the fourth lens has a convex surface facing the object side and has at least one aspherical surface;
Assuming that the focal length of the fourth lens is f4, the conditional expression |f4/f|>1
3. The lens system according to claim 1 or 2, which satisfies: A reflecting member for bending an optical path is provided between the fourth lens and the fifth lens,
Assuming that the air gap between the fourth lens and the fifth lens is D45, the axial distance of the first lens group is D1g, and the optical total length is TTL, the conditional expression D45/Imgh>3.
D1g/TTL <0.37
3. The lens system according to claim 1 or 2, which satisfies: The conditional expression 0.8 < TTL/f < 1.2 where TTL is the optical total length
3. The lens system according to claim 1 or 2, which satisfies: A lens system according to claim 1 or 2;
An imaging device comprising an image sensor. A movable body equipped with the lens system according to claim 1 or 2 and moving. The mobile object according to claim 7, wherein the mobile object is an unmanned aerial vehicle.

Images