Zoom lens and imaging apparatus

Abstract

A zoom lens according to the present disclosure includes a front-side lens group, an intermediate lens group, and a rear-side lens group. The intermediate lens group includes a diaphragm. The front-side lens group includes: a first positive lens group that is fixed during zooming and has a positive refractive power; one or more negative lens groups that move during zooming and each have a negative refractive power; and one or more second positive lens groups that move during zooming and each have a positive refractive power. Among the negative lens groups, a lens group having the strongest negative refractive power moves at the time of zooming such that an interval thereof from the first positive lens group is maximum at the telephoto end. The lens group having the strongest positive refractive power among the second positive lenses is disposed closer to the image plane than the lens group having the strongest negative refractive power among the negative lens groups. The lens group having the strongest positive refractive power moves at the time of zooming such that an interval from the lens group having the strongest negative refractive power is minimum at the telephoto end.

Description

Technical Field

[0001] The present disclosure relates to a zoom lens and an imaging device. Background Art

[0002] Photographic optical systems used in imaging devices (cameras) require optical systems with various focal lengths and apertures depending on their intended use. For example, telephoto zoom lenses capable of capturing magnified images of distant subjects at a desired angle of view are in demand for lenses with a larger aperture than that of lenses with an F-number of approximately 2.8. Such telephoto zoom lenses with large apertures are required to have high image quality while being compact and lightweight. As zoom lenses that meet these requirements, positive-lead zoom lenses have been proposed, in which a lens group with positive refractive power is positioned closest to the object (see, for example, PTLs 1 and 2).

[0003] Reference List

[0004] Patent Literature

[0005] PTL 1: Japanese Unexamined Patent Application Publication No. 2016-161878

[0006] PTL 2: Japanese Unexamined Patent Application Publication No. 2019-113750 Summary of the Invention

[0007] In order to achieve high image quality and reduce the size and weight of a telephoto zoom lens with a large aperture, it is important to appropriately set the refractive power of the lens group that moves during zooming and the positive refractive power lens group positioned closest to the object. The zoom lenses proposed in PTL 1 and PTL 2 have difficulty achieving both sufficiently high performance and a large aperture because the positive refractive power of the lens group positioned closest to the object is too strong.

[0008] It is desirable to provide a zoom lens having a short total optical length while achieving a large aperture larger than that of a lens with an F-number of approximately 2.8 and enabling various aberrations to be favorably corrected despite being small in size and light in weight, and an imaging device including such a zoom lens.

[0009] A zoom lens according to an embodiment of the present disclosure includes, from the object side toward the image plane side, in sequence: a front lens group; a middle lens group including an aperture; and a rear lens group, wherein the front lens group includes a first positive lens group, one or more negative lens groups and one or more second positive lens groups, the first positive lens group is arranged on the side closest to the object and is fixed when the magnification is changed, the first positive lens group has positive refractive power, the one or more negative lens groups move when the magnification is changed, the one or more negative lens groups all have negative refractive power, the one or more second positive lens groups move when the magnification is changed, the one or more second positive lens groups all have positive refractive power, and the lens group with the strongest negative refractive power among the one or more negative lens groups moves when the magnification is changed, so that the lens group with the strongest negative refractive power moves relative to the first positive lens group The interval is maximum at the telephoto end, the lens group with the strongest positive refractive power among the one or more second positive lens groups is arranged on the side closer to the image plane than the lens group with the strongest negative refractive power among the one or more negative lens groups, the lens group with the strongest positive refractive power moves when changing magnification so that the interval with respect to the lens group with the strongest negative refractive power is minimum at the telephoto end, the middle lens group includes a lens group with positive refractive power that moves together with the aperture stop when changing magnification so that the interval with respect to the lens group with the strongest negative refractive power among the one or more negative lens groups is minimum at the telephoto end, the rear lens group includes at least one focusing lens group that moves in the optical axis direction when focusing from an object at infinity to an object at a close distance, and the following conditional expression is satisfied:

[0010] 0.85 <fl1 / SQRT(fw×ft)<3......(1)

[0011] in

[0012] fl1 represents the focal length of the first positive lens group,

[0013] fw represents the focal length of the entire system at the wide-angle end when focused at infinity, and

[0014] ft represents the focal length of the entire system at the telephoto end when focused at infinity.

[0015] An imaging device according to an embodiment of the present disclosure includes a zoom lens and an imaging element that outputs an imaging signal corresponding to an optical image formed by the zoom lens. The zoom lens is configured by the zoom lens according to an embodiment of the present disclosure.

[0016] In a zoom lens or imaging device according to an embodiment of the present disclosure, the configuration of the corresponding lens groups is optimized to achieve a short total optical length while realizing a large aperture larger than that of a lens with an F-number of approximately 2.8, and to enable favorable correction of various aberrations despite its small size and light weight. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a lens cross-sectional view of a first configuration example (Example 1) of a zoom lens according to an embodiment of the present disclosure.

[0018] Figure 2 1 is an aberration diagram illustrating longitudinal aberration at the time of infinity focusing at the wide-angle end of the zoom lens according to Example 1.

[0019] Figure 3 1 is an aberration diagram illustrating longitudinal aberration at the time of infinity focusing at the intermediate position of the zoom lens according to Example 1.

[0020] Figure 4 1 is an aberration diagram illustrating longitudinal aberration at the time of infinity focusing at the telephoto end of the zoom lens according to Example 1.

[0021] Figure 5 are aberration diagrams illustrating longitudinal aberrations at the time of close focusing at the wide-angle end of the zoom lens according to Example 1.

[0022] Figure 6 1 is an aberration diagram illustrating longitudinal aberration at close focusing at an intermediate position of the zoom lens according to Example 1.

[0023] Figure 7 are aberration diagrams illustrating longitudinal aberrations at the time of close focusing at the telephoto end of the zoom lens according to Example 1.

[0024] Figure 8 are aberration diagrams illustrating lateral aberrations at the time of infinity focusing at the wide-angle end of the zoom lens according to Example 1.

[0025] Figure 9 1 is an aberration diagram illustrating lateral aberration at the time of infinity focusing at the intermediate position of the zoom lens according to Example 1.

[0026] Figure 10 are aberration diagrams illustrating lateral aberrations at the time of infinity focusing at the telephoto end of the zoom lens according to Example 1.

[0027] Figure 11 are aberration diagrams illustrating lateral aberrations at the time of close focusing at the wide-angle end of the zoom lens according to Example 1.

[0028] Figure 12 are aberration diagrams illustrating lateral aberrations at close focusing at an intermediate position of the zoom lens according to Example 1.

[0029] Figure 13 are aberration diagrams illustrating lateral aberrations at the time of close focusing at the telephoto end of the zoom lens according to Example 1.

[0030] Figure 14is a lens cross-sectional view of a second configuration example (Example 2) of the zoom lens according to the embodiment.

[0031] Figure 15 1 is an aberration diagram illustrating longitudinal aberration at the time of infinity focusing at the wide-angle end of the zoom lens according to Example 2.

[0032] Figure 16 1 is an aberration diagram illustrating longitudinal aberration at the time of infinity focusing at the intermediate position of the zoom lens according to Example 2.

[0033] Figure 17 1 is an aberration diagram illustrating longitudinal aberration at the time of infinity focusing at the telephoto end of the zoom lens according to Example 2.

[0034] Figure 18 are aberration diagrams illustrating longitudinal aberrations at the time of close focusing at the wide-angle end of the zoom lens according to Example 2.

[0035] Figure 19 1 is an aberration diagram illustrating longitudinal aberration at close focusing at an intermediate position of the zoom lens according to Example 2.

[0036] Figure 20 are aberration diagrams illustrating longitudinal aberrations at the time of close focusing at the telephoto end of the zoom lens according to Example 2.

[0037] Figure 21 are aberration diagrams illustrating lateral aberrations at the time of infinity focusing at the wide-angle end of the zoom lens according to Example 2.

[0038] Figure 22 1 is an aberration diagram illustrating lateral aberration at the time of infinity focusing at the intermediate position of the zoom lens according to Example 2.

[0039] Figure 23 are aberration diagrams illustrating lateral aberrations at the time of infinity focusing at the telephoto end of the zoom lens according to Example 2.

[0040] Figure 24 are aberration diagrams illustrating lateral aberrations at the time of close focusing at the wide-angle end of the zoom lens according to Example 2.

[0041] Figure 25 1 is an aberration diagram illustrating lateral aberration at close focusing at an intermediate position of the zoom lens according to Example 2.

[0042] Figure 26 are aberration diagrams illustrating lateral aberrations at the time of close focusing at the telephoto end of the zoom lens according to Example 2.

[0043] Figure 27is a lens cross-sectional view of a third configuration example (Example 3) of the zoom lens according to the embodiment.

[0044] Figure 28 1 is an aberration diagram illustrating longitudinal aberration at the time of infinity focusing at the wide-angle end of the zoom lens according to Example 3.

[0045] Figure 29 1 is an aberration diagram illustrating longitudinal aberration at the time of infinity focusing at the intermediate position of the zoom lens according to Example 3.

[0046] Figure 30 1 is an aberration diagram illustrating longitudinal aberration at the time of infinity focusing at the telephoto end of the zoom lens according to Example 3.

[0047] Figure 31 are aberration diagrams illustrating longitudinal aberration at the time of close focusing at the wide-angle end of the zoom lens according to Example 3.

[0048] Figure 32 1 is an aberration diagram illustrating longitudinal aberration at close focusing at an intermediate position of the zoom lens according to Example 3.

[0049] Figure 33 are aberration diagrams illustrating longitudinal aberrations at the time of close focusing at the telephoto end of the zoom lens according to Example 3.

[0050] Figure 34 are aberration diagrams illustrating lateral aberrations at the time of infinity focusing at the wide-angle end of the zoom lens according to Example 3.

[0051] Figure 35 1 is an aberration diagram illustrating lateral aberration at the time of infinity focusing at the intermediate position of the zoom lens according to Example 3.

[0052] Figure 36 are aberration diagrams illustrating lateral aberrations at the time of infinity focusing at the telephoto end of the zoom lens according to Example 3.

[0053] Figure 37 are aberration diagrams illustrating lateral aberrations at the time of close focusing at the wide-angle end of the zoom lens according to Example 3.

[0054] Figure 38 1 is an aberration diagram illustrating lateral aberration at close focusing at an intermediate position of the zoom lens according to Example 3.

[0055] Figure 39 are aberration diagrams illustrating lateral aberrations at the time of close focusing at the telephoto end of the zoom lens according to Example 3.

[0056] Figure 40is a lens cross-sectional view of a fourth configuration example (Example 4) of the zoom lens according to the embodiment.

[0057] Figure 41 4 are aberration diagrams illustrating longitudinal aberrations at the time of infinity focusing at the wide-angle end of the zoom lens according to Example 4.

[0058] Figure 42 4 are aberration diagrams illustrating longitudinal aberrations at the time of infinity focusing at the intermediate position of the zoom lens according to Example 4.

[0059] Figure 43 4 are aberration diagrams illustrating longitudinal aberrations at the time of infinity focusing at the telephoto end of the zoom lens according to Example 4.

[0060] Figure 44 are aberration diagrams illustrating longitudinal aberrations at the time of close focusing at the wide-angle end of the zoom lens according to Example 4.

[0061] Figure 45 4 are aberration diagrams illustrating longitudinal aberrations at the time of close focusing at an intermediate position of the zoom lens according to Example 4.

[0062] Figure 46 are aberration diagrams illustrating longitudinal aberrations at the time of close focusing at the telephoto end of the zoom lens according to Example 4.

[0063] Figure 47 4 are aberration diagrams illustrating lateral aberrations at the time of infinity focusing at the wide-angle end of the zoom lens according to Example 4.

[0064] Figure 48 4 are aberration diagrams illustrating lateral aberrations at the time of infinity focusing at the intermediate position of the zoom lens according to Example 4.

[0065] Figure 49 are aberration diagrams illustrating lateral aberrations at the time of infinity focusing at the telephoto end of the zoom lens according to Example 4.

[0066] Figure 50 are aberration diagrams illustrating lateral aberrations at the time of close focusing at the wide-angle end of the zoom lens according to Example 4.

[0067] Figure 51 are aberration diagrams illustrating lateral aberrations at close focusing at an intermediate position of the zoom lens according to Example 4.

[0068] Figure 52 are aberration diagrams illustrating lateral aberrations at the time of close focusing at the telephoto end of the zoom lens according to Example 4.

[0069] Figure 53is a lens cross-sectional view of a fifth configuration example (Example 5) of the zoom lens according to the embodiment.

[0070] Figure 54 5 are aberration diagrams illustrating longitudinal aberrations at the time of infinity focusing at the wide-angle end of the zoom lens according to Example 5.

[0071] Figure 55 5 are aberration diagrams illustrating longitudinal aberrations at the time of infinity focusing at the intermediate position of the zoom lens according to Example 5.

[0072] Figure 56 5 are aberration diagrams illustrating longitudinal aberrations at the time of infinity focusing at the telephoto end of the zoom lens according to Example 5.

[0073] Figure 57 are aberration diagrams illustrating longitudinal aberration at the time of close focusing at the wide-angle end of the zoom lens according to Example 5.

[0074] Figure 58 5 are aberration diagrams illustrating longitudinal aberrations at the time of close focusing at an intermediate position of the zoom lens according to Example 5.

[0075] Figure 59 are aberration diagrams illustrating longitudinal aberrations at the time of close focusing at the telephoto end of the zoom lens according to Example 5.

[0076] Figure 60 5 are aberration diagrams illustrating lateral aberrations at the time of infinity focusing at the wide-angle end of the zoom lens according to Example 5.

[0077] Figure 61 5 are aberration diagrams illustrating lateral aberrations at the time of infinity focusing at the intermediate position of the zoom lens according to Example 5.

[0078] Figure 62 5 are aberration diagrams illustrating lateral aberrations at the time of infinity focusing at the telephoto end of the zoom lens according to Example 5.

[0079] Figure 63 are aberration diagrams illustrating lateral aberrations at the time of close focusing at the wide-angle end of the zoom lens according to Example 5.

[0080] Figure 64 are aberration diagrams illustrating lateral aberrations at close focusing at an intermediate position of the zoom lens according to Example 5.

[0081] Figure 65 are aberration diagrams illustrating lateral aberrations at the time of close focusing at the telephoto end of the zoom lens according to Example 5.

[0082] Figure 66 is a block diagram illustrating a configuration example of an imaging device.

[0083] Figure 67 is a block diagram depicting a schematic configuration example of a vehicle control system.

[0084] Figure 68 1 and 2 are diagrams of assistance in explaining examples of installation positions of the vehicle exterior information detection portion and the imaging portion.

[0085] Figure 69 is a diagram illustrating a schematic configuration example of an endoscope system.

[0086] Figure 70 It's a picture Figure 69 A block diagram of an example of a functional configuration of a camera and a camera control unit (CCU) illustrated in FIG.

[0087] Figure 71 is a diagram illustrating a schematic configuration example of a microsurgery system. DETAILED DESCRIPTION

[0088] Now, a description will be given in detail of the embodiments of the present disclosure with reference to the accompanying drawings. Note that the description will be given in the following order.

[0089] 1. Basic configuration of the lens

[0090] 2. Working principle and effect

[0091] 3. Application Example of Imaging Device

[0092] 4. Numerical Examples of Lenses

[0093] 5. Practical Application Examples

[0094] 6. Other embodiments

[0095] <1. Basic configuration of the lens>

[0096] Figure 1 A first configuration example of the zoom lens according to an embodiment of the present disclosure is illustrated, and corresponds to the configuration of Example 1 described later. Figure 14 A second configuration example of the zoom lens according to the embodiment is illustrated, and corresponds to the configuration of Example 2 described later. Figure 27 A third configuration example of the zoom lens according to the embodiment is illustrated, and corresponds to the configuration of Example 3 described later. Figure 40 A fourth configuration example of the zoom lens according to the embodiment is illustrated, and corresponds to the configuration of Example 4 described later. Figure 53 A fifth configuration example of the zoom lens according to the embodiment is illustrated, and corresponds to the configuration of Example 5 described later.

[0097] exist Figure 1In the figures and other figures, Z1 represents the optical axis. According to the first to fifth configuration examples, an optical member such as a cover glass may be provided between the image plane IMG and any of the zoom lenses 1 to 5 to protect the imaging element. Furthermore, in addition to the cover glass, various filters such as a low-pass filter or an infrared cut filter may be provided as optical members.

[0098] In the following, according to Figure 1 A description of the zoom lens configuration according to an embodiment of the present disclosure will be given appropriately in association with the zoom lenses 1 to 5 of the respective configuration examples illustrated in other figures. However, the technology according to the present disclosure is not limited to the illustrated configuration examples.

[0099] The zoom lens according to the embodiment includes, in order from the object side to the image plane side, a front lens group GA, an intermediate lens group Gs including an aperture stop St, and a rear lens group GB.

[0100] Note that in the examples described later, the zoom lenses 1 to 3 according to Examples 1 to 3 each have a seven-group configuration including the first lens group G1 to the seventh lens group G7, and the zoom lenses 4 and 5 according to Examples 4 and 5 each have an eight-group configuration including the eighth lens group G8. In the zoom lens 1 according to Example 1, the first lens group G1 to the third lens group G3 constitute the front lens group GA, the fourth lens group G4 including the aperture stop St constitutes the middle lens group Gs, and the fifth lens group G5 to the seventh lens group G7 constitute the rear lens group GB. In the zoom lenses 2 and 3 according to Examples 2 and 3, the first lens group G1 to the fourth lens group G4 constitute the front lens group GA, the fifth lens group G5 including the aperture stop St constitutes the middle lens group Gs, and the sixth lens group G6 and the seventh lens group G7 constitute the rear lens group GB. In the zoom lenses 4 and 5 according to Examples 4 and 5, the first lens group G1 to the fourth lens group G4 constitute the front lens group GA, the fifth lens group G5 including the aperture stop St constitutes the middle lens group Gs, and the sixth lens group G6 to the eighth lens group G8 constitute the rear lens group GB.

[0101] Here, in the zoom lens according to the embodiment, a "lens group" refers to a lens group having refractive power and having a spacing relative to adjacent lens groups that changes during zooming. A lens group configured only by a flat plate having no refractive power is not defined as a lens group.

[0102] In the zoom lens according to the embodiment, when zooming from the wide-angle end to the telephoto end, the intervals between adjacent lens groups change. Note that, Figure 1 The upper portion of the figure and the other figures illustrate the lens arrangement at the wide-angle end (Wide) when focusing at infinity, and the middle portion illustrates the lens arrangement when focusing at infinity at the intermediate position (Mid). Figure 1 and other figures illustrate the lens arrangement at the telephoto end (Tele) at the time of focusing at infinity at the lower part.

[0103] The front lens group GA includes a first positive lens group Gf, one or more negative lens groups Gn, and one or more second positive lens groups Gp. The first positive lens group Gf is positioned on the side closest to the object; the first positive lens group Gf is fixed during zooming and has positive refractive power. The one or more negative lens groups Gn move during zooming and have negative refractive power. The one or more second positive lens groups Gp move during zooming and have positive refractive power.

[0104] The lens group Gn1 having the strongest negative refractive power among the one or more negative lens groups Gn is moved during zooming so that the spacing relative to the first positive lens group Gf is maximized at the telephoto end. Note that in the examples described later, the second lens group G2 corresponds to the lens group Gn1 in the zoom lenses 1 to 5 according to Examples 1 to 5.

[0105] The lens group Gp1 having the strongest positive refractive power among the one or more second positive lens groups Gp is ​​arranged closer to the image plane than the lens group Gn1 having the strongest negative refractive power, and moves during zooming so that the spacing relative to the lens group Gn1 having the strongest negative refractive power is minimized at the telephoto end. Note that in the examples described later, the third lens group G3 corresponds to the lens group Gp1 in the zoom lenses 1 to 3 according to Examples 1 to 3; and the fourth lens group G4 corresponds to the lens group Gp1 in the zoom lenses 4 and 5 according to Examples 4 and 5.

[0106] The middle lens group Gs includes a lens group having positive refractive power and moves together with the aperture stop St during zooming so that the interval with respect to the lens group Gn1 having the strongest negative refractive power among the one or more negative lens groups Gn is smallest at the telephoto end.

[0107] The rear lens group GB includes at least one focusing lens group that moves in the optical axis direction when focusing from an infinitely distant object to a close object.

[0108] In addition to the above, the zoom lens according to the embodiment may satisfy predetermined conditional expressions and the like described later.

[0109] <2. Working Principle and Effect>

[0110] Next, a description is given of the operating principle and effects of the zoom lens according to the embodiment of the present disclosure. In addition, a description is given of a more preferred configuration in the zoom lens according to the embodiment of the present disclosure and its operating principle and effects.

[0111] It should be noted that the effects described herein are merely exemplary and not limiting, and other effects may also be included.

[0112] According to the zoom lens of the embodiment, the configuration of the respective lens groups is optimized to achieve a large aperture larger than that of a lens having an F-number of approximately 2.8 while achieving a short total optical length, and to facilitate correction of various aberrations despite being small in size and light in weight. This makes it possible to provide a zoom lens that achieves a large aperture larger than that of a lens having an F-number of approximately 2.8 while having a short total optical length, and to facilitate correction of various aberrations despite being small in size and light in weight, and an imaging device including such a zoom lens.

[0113] In the zoom lens according to the embodiment, the provision of a first positive lens group Gf and a negative lens group Gn, which moves during zooming and has negative refractive power, results in a telephoto configuration for the optical system. This allows for an increase in focal length at the telephoto end while reducing the overall optical length. Furthermore, the movement of the negative lens group Gn during zooming enables the main operating principle of zooming to be achieved. Furthermore, the movement of the intermediate lens group Gs along with the aperture stop St during zooming, minimizing the spacing relative to the lens group Gn1 at the telephoto end, suppresses variations in aberrations that occur during zooming and offers the advantage of reducing the lens diameter of the zoom lens closest to the object.

[0114] In the zoom lens according to the embodiment, the front lens group GA may have positive refractive power as a whole. In this case, arranging the focusing lens group in the rear lens group GB enables the lens diameter of the focusing lens group to be smaller, thereby reducing the weight and size of the focusing lens group, which is advantageous in achieving high-speed autofocus.

[0115] The zoom lens according to the embodiment can satisfy the following conditional expression (1):

[0116] 0.85 <fl1 / SQRT(fw×ft)<3......(1)

[0117] in

[0118] fl1 represents the focal length of the first positive lens group Gf,

[0119] fw represents the focal length of the entire system at the wide-angle end when focused at infinity, and

[0120] ft represents the focal length of the entire system at the telephoto end when focused at infinity.

[0121] Conditional expression (1) is a conditional expression that makes the focal length of the first positive lens group Gf have an appropriate ratio relationship with the geometric mean of the focal lengths of the entire system at the wide-angle end and the telephoto end when focusing at infinity. Satisfying conditional expression (1) makes the focal length of the first positive lens group Gf relative to the focal length of the entire system within an appropriate range, thereby making it possible to achieve size reduction while favorably correcting aberrations. Being lower than the lower limit of conditional expression (1) makes the positive refractive power of the first positive lens group Gf too strong, thereby making it difficult to correct various aberrations such as axial chromatic aberration or spherical aberration that appear at the first positive lens group Gf. In addition, exceeding the upper limit of conditional expression (1) makes the positive refractive power of the first positive lens group Gf too weak, thereby making it impossible to reduce the total optical length, which makes it difficult to achieve size reduction.

[0122] Note that setting the numerical range of the conditional expression (1) as in the following conditional expression (1A) makes it possible to obtain a better effect.

[0123] 1 <fl1 / SQRT(fw×ft)≤2.5...... (1A)

[0124] In addition, the zoom lens according to the embodiment can satisfy the following conditional expression (2):

[0125] 0.7 <Ds / Dp1<10...... (2)

[0126] in

[0127] Ds represents the amount of movement of the middle lens group Gs from the wide-angle end to the telephoto end when zooming, and

[0128] Dp1 represents the movement amount of the lens group Gp1 having the strongest positive refractive power among the one or more second positive lens groups Gp at the time of zooming from the wide-angle end to the telephoto end.

[0129] Conditional expression (2) is a conditional expression that makes the amount of movement of the intermediate lens group Gs and the amount of movement of the lens group Gp1 when changing the magnification from the wide-angle end to the telephoto end have an appropriate ratio relationship. Satisfying conditional expression (2) makes the ratio between the amount of movement of the intermediate lens group Gs and the amount of movement of the lens group Gp1 when changing the magnification from the wide-angle end to the telephoto end within an appropriate range, thereby making it possible to achieve size reduction despite the large aperture. Being below the lower limit of conditional expression (2) reduces the amount of movement of the intermediate lens group Gs when changing the magnification from the wide-angle end to the telephoto end. Because the distance between the aperture stop St and the first positive lens group Gf at the telephoto end is too far, this increases the diameter of the first positive lens group Gf, making it difficult to achieve size reduction. In addition, exceeding the upper limit of conditional expression (2) increases the amount of movement of the intermediate lens group Gs when changing the magnification from the wide-angle end to the telephoto end. This increases the total optical length, thereby making it difficult to achieve size reduction.

[0130] Note that setting the numerical range of conditional expression (2) as in the following conditional expression (2A) makes it possible to obtain a better effect.

[0131] 0.8 <Ds / Dp1<8.5......(2A)

[0132] In addition, the zoom lens according to the embodiment can satisfy the following conditional expression (3):

[0133] 3.8 <Dn1 / Dp1<20......(3)

[0134] in

[0135] Dn1 represents the movement amount of the lens group Gn1 having the strongest negative refractive power among the one or more negative lens groups Gn when zooming from the wide-angle end to the telephoto end, and

[0136] Dp1 represents the movement amount of the lens group Gp1 having the strongest positive refractive power among the one or more second positive lens groups Gp at the time of zooming from the wide-angle end to the telephoto end.

[0137] Conditional expression (3) is a conditional expression that makes the amount of movement of lens group Gn1 and the amount of movement of lens group Gp1 when changing magnification from the wide-angle end to the telephoto end have an appropriate ratio relationship. Satisfying conditional expression (3) makes the ratio between the amount of movement of lens group Gn1 and the amount of movement of lens group Gp1 when changing magnification from the wide-angle end to the telephoto end within an appropriate range, thereby making it possible to achieve size reduction while ensuring variable magnification. Being lower than the lower limit of conditional expression (3) reduces the amount of movement of lens group Gn1 when changing magnification from the wide-angle end to the telephoto end, which is responsible for the main variable magnification. This makes it difficult to ensure variable magnification. In addition, exceeding the upper limit of conditional expression (3) increases the amount of movement of lens group Gn1 when changing magnification from the wide-angle end to the telephoto end. This increases the total optical length, and because the distance between lens group Gn1 and the first positive lens group Gf at the telephoto end is too far, the diameter of the first positive lens group Gf increases, making it difficult to achieve size reduction.

[0138] Note that setting the numerical range of conditional expression (3) as in the following conditional expression (3A) makes it possible to obtain a better effect.

[0139] 4 <Dn1 / Dp1<17......(3A)

[0140] In addition, the zoom lens according to the embodiment can satisfy the following conditional expression (4):

[0141] 1.1 <TL / ft<1.8......(4)

[0142] in

[0143] TL represents the total optical length of the zoom lens, and

[0144] ft represents the focal length of the entire system at the telephoto end when focused at infinity.

[0145] Conditional expression (4) is a conditional expression that makes the total optical length of the zoom lens and the focal length of the entire system at the telephoto end when focusing at infinity have an appropriate ratio relationship. Satisfying conditional expression (4) makes the focal length of the entire system at the telephoto end when focusing at infinity within an appropriate range relative to the total optical length of the zoom lens. This reduces the total optical length of the zoom lens relative to the focal length of the entire system at the telephoto end when focusing at infinity, thereby making it possible to achieve size reduction. Being below the lower limit of conditional expression (4) makes the telephoto ratio too small, thereby making it difficult to correct various aberrations such as spherical aberration or axial chromatic aberration. In addition, exceeding the upper limit of conditional expression (4) makes the telephoto ratio too large, thereby increasing the total optical length, thereby making it difficult to achieve size reduction.

[0146] Note that setting the numerical range of conditional expression (4) as in the following conditional expression (4A) makes it possible to obtain a better effect.

[0147] 1.2 <TL / ft<1.7......(4A)

[0148] In addition, the zoom lens according to the embodiment can satisfy the following conditional expression (5):

[0149] 0.4 <fp1 / SQRT(fw×ft)<2......(5)

[0150] in

[0151] fp1 represents the focal length of the lens group Gp1 having the strongest positive refractive power among the one or more second positive lens groups Gp,

[0152] fw represents the focal length of the entire system at the wide-angle end when focused at infinity, and

[0153] ft represents the focal length of the entire system at the telephoto end when focused at infinity.

[0154] Conditional expression (5) is a conditional expression that makes the focal length of lens group Gp1 have an appropriate ratio relationship with the geometric mean of the focal lengths of the entire system at the wide-angle end and the telephoto end when focusing at infinity. Satisfying conditional expression (5) makes the focal length of lens group Gp1 within an appropriate range relative to the focal length of the entire system, thereby making it possible to achieve size reduction while favorably correcting aberrations. Being below the lower limit of conditional expression (5) makes the positive refractive power of lens group Gp1 too strong, thereby making it difficult to correct various aberrations such as spherical aberration or coma. In addition, exceeding the upper limit of conditional expression (5) makes the positive refractive power of lens group Gp1 too weak. This makes the converging effect of the light beam on the object side smaller than that at the aperture stop St, thereby increasing the total optical length and increasing the aperture. This makes it inevitable to install a larger-sized component together with the aperture mechanism, thereby making it difficult to achieve size reduction.

[0155] Note that setting the numerical range of conditional expression (5) as in the following conditional expression (5A) enables to obtain a better effect.

[0156] 0.5 <fp1 / SQRT(fw×ft)<1.85......(5A)

[0157] In addition, the zoom lens according to the embodiment can satisfy the following conditional expression (6):

[0158] 0.27<|fn1 / SQRT(fw×ft)|<2......(6)

[0159] in

[0160] fn1 represents the focal length of the lens group Gn1 having the strongest negative refractive power among the one or more negative lens groups Gn,

[0161] fw represents the focal length of the entire system at the wide-angle end when focused at infinity, and

[0162] ft represents the focal length of the entire system at the telephoto end when focused at infinity.

[0163] Conditional expression (6) is a conditional expression that makes the focal length of lens group Gn1 have an appropriate ratio absolute value relationship with the geometric mean of the focal lengths of the entire system at the wide-angle end and the telephoto end when focusing at infinity. Satisfying conditional expression (6) makes the focal length of lens group Gn1 within an appropriate range relative to the focal length of the entire system, thereby making it possible to achieve size reduction while favorably correcting aberrations. Being lower than the lower limit of conditional expression (6) makes the negative refractive power of lens group Gn1 too strong, thereby making it difficult to correct various aberrations such as coma or distortion at the wide-angle end. In addition, exceeding the upper limit of conditional expression (6) makes the negative refractive power of lens group Gn1 too weak. This makes it impossible to obtain the desired variable magnification, or makes it difficult to achieve size reduction due to an increase in the total optical length.

[0164] Note that setting the numerical range of conditional expression (6) as in the following conditional expression (6A) makes it possible to obtain a better effect.

[0165] 0.3<|fn1 / SQRT(fw×ft)|<1.5......(6A)

[0166] In addition, in the zoom lens according to the embodiment, the first positive lens group Gf can be configured by three or fewer lenses. The first positive lens group Gf is arranged on the side closest to the object, so it has a large lens diameter; the configuration of three or fewer lenses makes it possible to achieve reductions in size and weight.

[0167] In addition, the zoom lens according to the embodiment can satisfy the following conditional expression (7):

[0168] 0.1 <Lf / SQRT(fw×ft)<0.28......(7)

[0169] in

[0170] Lf represents the thickness of the first positive lens group Gf,

[0171] fw represents the focal length of the entire system at the wide-angle end when focused at infinity, and

[0172] ft represents the focal length of the entire system at the telephoto end when focused at infinity.

[0173] Conditional expression (7) is a conditional expression that makes the thickness of the first positive lens group Gf have an appropriate ratio relationship with the geometric mean of the focal lengths of the entire system at the wide-angle end and the telephoto end when focusing at infinity. Satisfying conditional expression (7) makes the thickness of the first positive lens group Gf within an appropriate range relative to the focal length of the entire system, thereby making it possible to achieve a reduction in size and weight while favorably correcting aberrations. Being below the lower limit of conditional expression (7) makes the thickness of the first positive lens group Gf too thin, thereby making it difficult to correct various aberrations such as axial chromatic aberration or spherical aberration that occur at the first positive lens group Gf. In addition, exceeding the upper limit of conditional expression (7) makes the first positive lens group Gf too thick, thereby increasing the diameter of the first positive lens group Gf and also increasing the number of lenses with large diameters. This makes the weight of the optical system too heavy, thereby making it difficult to achieve a reduction in size and weight.

[0174] Note that setting the numerical range of conditional expression (7) as in the following conditional expression (7A) enables to obtain a better effect.

[0175] 0.14 <Lf / SQRT(fw×ft)<0.24......(7A)

[0176] Furthermore, in the zoom lens according to the embodiment, the focus lens group can be provided only in the rear lens group GB. In particular, when multiple focus lens groups are provided to improve close-range performance, placing multiple focus lens groups in the rear lens group GB allows the diameter of each lens in the multiple focus lens groups to be reduced. This results in a reduction in weight and size of the focus lens group, which is advantageous in achieving high-speed autofocus.

[0177] In addition, the zoom lens according to the embodiment can satisfy the following conditional expression (8):

[0178] 0.18 <BF / SQRT(fw×ft)<0.35......(8)

[0179] in

[0180] BF represents the back focal length of the zoom lens,

[0181] fw represents the focal length of the entire system at the wide-angle end when focused at infinity, and

[0182] ft represents the focal length of the entire system at the telephoto end when focused at infinity.

[0183] Conditional expression (8) is a conditional expression that makes the back focus of the zoom lens have an appropriate ratio relationship with the geometric mean of the focal lengths of the entire system at the wide-angle end and the telephoto end when focusing at infinity. Satisfying conditional expression (8) makes the back focus within an appropriate range relative to the focal length of the entire system, thereby making it possible to achieve size reduction while ensuring peripheral illumination. Falling below the lower limit of conditional expression (8) shortens the back focus, which makes the angle of the light beam incident on the imaging element too small, thereby making it difficult to ensure peripheral illumination. In addition, exceeding the upper limit of conditional expression (8) lengthens the back focus, which increases the total optical length, thereby making it difficult to achieve size reduction.

[0184] Note that setting the numerical range of Conditional Expression (8) as in the following Conditional Expression (8A) makes it possible to obtain a better effect.

[0185] 0.2 <BF / SQRT(fw×ft)<0.33......(8A)

[0186] <3. Example of Application to Imaging Device>

[0187] Next, a description is given of an example in which the zoom lens according to the embodiment of the present disclosure is applied to a specific imaging device.

[0188] Figure 66 The present invention illustrates an example configuration of an imaging device 100 to which a zoom lens according to an embodiment is applied. The imaging device 100 is, for example, a digital still camera and includes a camera block 110, a camera signal processing section 20, an image processing section 30, an LCD (Liquid Crystal Display) 40, an R / W (Reader / Writer) 50, a CPU (Central Processing Unit) 60, an input section 70, and a lens drive control section 80.

[0189] The camera block 110 plays a role in the imaging function and includes an imaging lens 111 and an imaging element 112 such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). The imaging element 112 converts the optical image formed by the imaging lens 111 into an electrical signal, thereby outputting an imaging signal (image signal) corresponding to the optical image. Figure 1 Any of the zoom lenses 1 to 5 according to corresponding configuration examples illustrated in the other drawings is applicable as the imaging lens 111 .

[0190] The camera signal processing section 20 performs various types of signal processing on the image signal output from the imaging element 112 , including, for example, analog-to-digital conversion, noise removal, image quality correction, or conversion into luminance and color difference signals.

[0191] The image processing section 30 performs recording and reproducing processing of image signals. The image processing section 30 performs processing including, for example, compression encoding and expansion decoding processing of image signals based on a predetermined image data format and processing for converting data specifications such as resolution.

[0192] The LCD 40 has a function of displaying various types of data, including, for example, the status of user operations performed on the input unit 70 and captured images. The R / W 50 performs writing of image data encoded by the image processing unit 30 into the memory card 1000 and reading of image data recorded in the memory card 1000. For example, the memory card 1000 is a semiconductor memory that can be attached to and detached from a slot coupled to the R / W 50.

[0193] The CPU 60 functions as a control processing unit that controls each of the circuit blocks provided in the imaging device 100. The CPU 60 controls each of the circuit blocks based on, for example, command input signals from the input unit 70. The input unit 70 includes, for example, various switches for the user to perform desired operations. For example, the input unit 70 includes a shutter release button for performing a shutter operation, a selection switch for selecting an operating mode, and the like. The input unit 70 outputs command input signals corresponding to the operations performed by the user to the CPU 60. The lens drive control unit 80 controls the drive of the lenses provided in the camera block 110. For example, the lens drive control unit 80 controls motors (not shown) that drive the respective lenses of the imaging lens 111 based on control signals from the CPU 60.

[0194] Next, a description is given of the operation in the imaging apparatus 100 .

[0195] In a standby state at the time of image capture, an image signal corresponding to an image captured in the camera block 110 is output to the LCD 40 via the camera signal processing section 20, and is thus displayed as a camera-through image under the control of the CPU 60. In addition, when, for example, an instruction input signal for zooming or focusing is input from the input section 70, the CPU 60 outputs a control signal to the lens drive control section 80. This causes a predetermined lens of the imaging lens 111 to move under the control of the lens drive control section 80.

[0196] When a shutter (not shown) of the camera block 110 is operated in response to an instruction input signal from the input section 70, a captured image signal is output from the camera signal processing section 20 to the image processing section 30 to undergo compression encoding processing and thereby be converted into digital data in a predetermined data format. The converted data is output to the R / W 50 to be written to the memory card 1000.

[0197] Note that focusing is performed, for example, when the shutter release button of the input section 70 is half-pressed or when the shutter release button is fully pressed for recording (image capture). Focusing is performed by causing the lens drive control section 80 to move a predetermined lens of the imaging lens 111 based on a control signal from the CPU 60.

[0198] In the case where image data recorded in the memory card 1000 is to be reproduced, predetermined image data is read from the memory card 1000 by the R / W 50 according to an operation performed on the input section 70. The predetermined image data read from the memory card 1000 is subjected to expansion decoding processing by the image processing section 30. Thereafter, a reproduced image signal is output to the LCD 40, and thus a reproduced image is displayed.

[0199] It should be noted that while the above description illustrates the application of the imaging device to digital still cameras, the scope of application of the imaging device is not limited to digital still cameras. The imaging device is applicable to various other imaging devices. For example, the imaging device is applicable to digital single-lens reflex cameras, digital non-reflex cameras, digital video cameras, surveillance cameras, and the like. Furthermore, the imaging device is widely applicable to the camera portion of digital input / output devices such as camera-equipped mobile phones or camera-equipped information terminals. Furthermore, the imaging device is also applicable to interchangeable lens cameras.

[0200] [Example]

[0201] <4. Numerical Examples of Lenses>

[0202] Next, a description is given of specific numerical examples of the zoom lens according to an embodiment of the present disclosure. Here, a description is given of the following numerical examples: specific numerical values ​​are applied to Figure 1 and zoom lenses 1 to 5 of corresponding configuration examples illustrated in other figures.

[0203] It should be noted that the meanings of the corresponding symbols indicated in the following tables and descriptions are as follows. "Si" represents the number of the i-th surface in increasing order from the side closest to the object. "ri" represents the value of the paraxial curvature radius of the i-th surface (mm). "di" represents the value of the interval on the optical axis between the i-th surface and the (i+1)-th surface (mm). "ndi" represents the value of the refractive index of the material of the optical element having the i-th surface with respect to the d-line (wavelength 587.6nm). "νdi" represents the value of the Abbe number of the material of the optical element having the i-th surface in the d-line. Indicates the value of the effective diameter of the i-th surface (mm). The part where the value of "ri" is "∞" represents a flat surface, an aperture stop surface, etc. "ASP" in the surface number (Si) column indicates that the surface is configured by an aspherical shape. "STO" in the surface number column indicates that the aperture stop St is set at the corresponding position. "OBJ" in the surface number column indicates that the surface is the object surface (subject surface). "IMG" in the surface number column indicates that the surface is the image plane. "f" represents the focal length of the entire system (unit: mm). "Fno" represents the open F value (F number). "ω" represents the half angle of view (unit: °). "Y" represents the image height (unit: mm). "L" represents the total optical length (the distance from the surface on the side closest to the object to the optical axis of the image plane IMG) (unit: mm).

[0204] In addition, some of the lenses to be used in each of these examples have lens surfaces configured by aspherical surfaces. The aspherical shape is defined by the following expression. Note that in each of the tables showing aspherical coefficients described later, "Ei" represents an exponential representation with base 10, that is, "10 -i ”; for example, “0.12345E-05” means “0.12345×10 -5 ”.

[0205] (Expression of aspherical surface)

[0206] x=c 2 y 2 / (1+(1-(1+k)c 2 y 2 ) 1 / 2 )+A4·y 4 +A6·y 6 +A8·y 8 +A10·y 10

[0207] Here, assuming that "x" is the distance from the vertex of the lens surface in the optical axis direction (the amount of sag), "y" is the height in the direction perpendicular to the optical axis, "c" is the paraxial curvature (the inverse of the radius of curvature) at the vertex of the lens surface, and "k" is the conic constant. A4, A6, A8, and A10 are the 4th, 6th, 8th, and 10th order aspheric coefficients, respectively.

[0208] [Example 1]

[0209] Tables 1 and 2 show Figure 1Table 3 shows the basic lens data of the zoom lens 1 according to Example 1. Table 3 shows the values ​​of the focal length f, F-number, total angle of view 2ω, image height Y, and total optical length L of the entire system in the zoom lens 1 according to Example 1. Table 4 shows data on the surface spacing that varies during zooming and focusing in the zoom lens 1 according to Example 1. Note that Table 3 shows the values ​​at each of the wide-angle end (Wide), the middle position (Mid), and the telephoto end (Tele) when both the photographic distance and the object distance (d0) are infinite. Table 4 shows the values ​​at each of the wide-angle end (Wide), the middle position (Mid), and the telephoto end (Tele) when both the photographic distance and the object distance (d0) are infinite and when both the photographic distance and the object distance (d0) are close. Table 5 shows the values ​​of the coefficients indicating the shape of the aspherical surfaces in the zoom lens 1 according to Example 1. Table 6 shows the starting surface and focal length (unit: mm) of each of the lens groups of the zoom lens 1 according to Example 1.

[0210] The zoom lens 1 according to Example 1 has a configuration in which the first lens group G1 to the seventh lens group G7 are arranged in order from the object side toward the image plane side. An aperture stop St is provided on the object side of the fourth lens group G4.

[0211] When zooming from the wide-angle end to the telephoto end, the second lens group G2 through the seventh lens group G7 (the last lens group) move, changing the spacing between adjacent lens groups. The first lens group G1 (first positive lens group Gf) remains fixed during zooming. When focusing from infinity to close object distances, the fifth lens group G5 moves toward the image plane along the optical axis.

[0212] In the zoom lens 1 according to Example 1, the first to third lens groups G1 to G3 constitute the front lens group GA, the fourth lens group G4 including the aperture stop St constitutes the middle lens group Gs, and the fifth to seventh lens groups G5 to G7 constitute the rear lens group GB.

[0213] In the zoom lens 1 according to Example 1, the second lens group G2 in the front lens group GA corresponds to the above-mentioned negative lens group Gn and the above-mentioned lens group Gn1 .

[0214] In the zoom lens 1 according to Example 1, the first lens group G1 in the front lens group GA corresponds to the above-mentioned first positive lens group Gf, and the third lens group G3 therein corresponds to the above-mentioned second positive lens group Gp and the above-mentioned lens group Gp1 .

[0215] The first lens group G1 has positive refractive power. It includes lenses L11 through L13, in order from the object side toward the image side. Lens L11 is a negative meniscus lens with a convex surface facing the object side. Lens L12 is a biconvex positive lens. Lens L13 is a positive meniscus lens with a convex surface facing the object side. Lenses L11 and L12 are attached to each other to form a cemented lens.

[0216] The second lens group G2 has negative refractive power. It includes lenses L21 to L24, in order from the object side toward the image side. Lens L21 is a negative meniscus lens with a convex surface facing the object side. Lens L22 is a positive meniscus lens with a convex surface facing the object side. Lenses L21 and L22 are attached to each other to form a cemented lens. Lens L23 is a biconcave negative lens. Lens L24 is a positive meniscus lens with a convex surface facing the object side.

[0217] The third lens group G3 has positive refractive power. The third lens group G3 includes, in order from the object side toward the image side, lens L31 and lens L32. Lens L31 is a positive meniscus lens with a convex surface facing the object side. Lens L32 is a biconvex positive lens.

[0218] The fourth lens group G4 has positive refractive power. It includes, in order from the object side toward the image side, lenses L41 to L44. Lens L41 is a positive meniscus lens with a convex surface facing the image side. Lens L42 is a biconcave negative lens. Lenses L41 and L42 are attached to each other to form a cemented lens. Lens L43 is a positive meniscus lens with a convex surface facing the object side. Lens L44 is a biconvex positive lens.

[0219] The fifth lens group G5 has negative refractive power. It includes, in order from the object side toward the image side, lens L51 and lens L52. Lens L51 is a biconvex positive lens. Lens L52 is a biconcave negative lens. Lens L51 and lens L52 are attached to each other to form a cemented lens.

[0220] The sixth lens group G6 has positive refractive power. It includes, in order from the object side toward the image side, lens L61 and lens L62. Lens L61 is a positive meniscus lens with a convex surface facing the image side. Lens L62 is a biconvex positive lens.

[0221] The seventh lens group G7 has negative refractive power and includes a lens L71. The lens L71 is a biconcave negative lens.

[0222] The above configuration realizes a zoom lens that has a short total optical length while achieving a large aperture larger than that of a lens with an F-number of approximately 2.8 and that can favorably correct various aberrations despite being small in size and light in weight.

[0223] [Table 1]

[0224]

[0225] [Table 2]

[0226]

[0227] [Table 3]

[0228]

[0229]

[0230] [Table 4]

[0231]

[0232] [Table 5]

[0233]

[0234] [Table 6]

[0235]

[0236] Figure 2 Illustrated are longitudinal aberrations at the time of infinity focusing at the wide-angle end of the zoom lens 1 according to Example 1. Figure 3 The longitudinal aberration at the time of infinity focusing at the middle position of the zoom lens 1 according to Example 1 is illustrated. Figure 4 Longitudinal aberrations at the time of infinity focusing at the telephoto end of the zoom lens 1 according to Example 1 are illustrated. Figure 5 Longitudinal aberrations at the time of close focusing at the wide-angle end of the zoom lens 1 according to Example 1 are illustrated. Figure 6 Longitudinal aberration at the time of close focusing at an intermediate position of the zoom lens 1 according to Example 1 is illustrated. Figure 7 Longitudinal aberrations at the time of close focusing at the telephoto end of the zoom lens 1 according to Example 1 are illustrated. Figure 8 Illustrated are lateral aberrations at the time of infinity focusing at the wide-angle end of the zoom lens 1 according to Example 1. Figure 9 The lateral aberration at the time of infinity focusing at the middle position of the zoom lens 1 according to Example 1 is illustrated. Figure 10 Illustrated are lateral aberrations at the time of infinity focusing at the telephoto end of the zoom lens 1 according to Example 1. Figure 11 Illustrated are lateral aberrations at the time of close focusing at the wide-angle end of the zoom lens 1 according to Example 1. Figure 12 Illustrated are lateral aberrations at the time of close focusing at an intermediate position of the zoom lens 1 according to Example 1. Figure 13Illustrated are lateral aberrations at the time of close focusing at the telephoto end of the zoom lens 1 according to Example 1.

[0237] Figures 2 to 7 The diagram shows spherical aberration, astigmatism (field curvature), and distortion as longitudinal aberrations. Figures 2 to 7 Spherical aberration diagram in and Figures 8 to 13 In the lateral aberration diagram in , the solid line indicates the value about the d-line (587.56 nm), the dashed line indicates the value about the g-line (435.84 nm), and the dotted line indicates the value about the C-line (656.27 nm). Figures 2 to 7 In the astigmatism diagram, S represents the value with respect to the sagittal image plane, and T represents the value with respect to the tangential image plane. Figures 2 to 7 The astigmatism and distortion diagrams in illustrate the values ​​for the d-line.

[0238] These apply similarly to the aberration diagrams in other subsequent examples.

[0239] As is understood from each of the aberration diagrams, the zoom lens 1 according to Example 1 favorably corrects various aberrations and thus has excellent image forming performance.

[0240] [Example 2]

[0241] Tables 7 and 8 show Figure 14 Table 9 shows the basic lens data of the zoom lens 2 according to Example 2. Table 9 shows the values ​​of the focal length f, F-number, total angle of view 2ω, image height Y, and total optical length L of the entire system in the zoom lens 2 according to Example 2. Table 10 shows data on the surface spacing that varies during zooming and focusing in the zoom lens 2 according to Example 2. Note that Table 9 shows the values ​​at each of the wide-angle end (Wide), the middle position (Mid), and the telephoto end (Tele) when both the photographic distance and the object distance (d0) are infinite. Table 10 shows the values ​​at each of the wide-angle end (Wide), the middle position (Mid), and the telephoto end (Tele) when both the photographic distance and the object distance (d0) are infinite, and when both the photographic distance and the object distance (d0) are close. Table 11 shows the values ​​of the coefficients indicating the shape of the aspherical surfaces in the zoom lens 2 according to Example 2. Table 12 shows the starting surface and focal length (unit: mm) of each of the lens groups of the zoom lens 2 according to Example 2.

[0242] The zoom lens 2 according to Example 2 has a configuration in which the first lens group G1 to the seventh lens group G7 are arranged in order from the object side toward the image plane side. An aperture stop St is provided inside the fifth lens group G5.

[0243] When zooming from the wide-angle end to the telephoto end, the second lens group G2 through the seventh lens group G7 (the final lens group) move, changing the spacing between adjacent lens groups. The first lens group G1 (first positive lens group Gf) remains fixed during zooming. When focusing from infinity to close object distances, the sixth lens group G6 moves toward the image plane along the optical axis.

[0244] In the zoom lens 2 according to Example 2, the first lens group G1 to the fourth lens group G4 constitute the front lens group GA, the fifth lens group G5 including the aperture stop St constitutes the middle lens group Gs, and the sixth lens group G6 and the seventh lens group G7 constitute the rear lens group GB.

[0245] In the zoom lens 2 according to Example 2, the second lens group G2 and the fourth lens group G4 in the front lens group GA correspond to the above-mentioned negative lens group Gn, and the second lens group G2 corresponds to the above-mentioned lens group Gn1.

[0246] In the zoom lens 2 according to Example 2, the first lens group G1 in the front lens group GA corresponds to the above-mentioned first positive lens group Gf, and the third lens group G3 corresponds to the above-mentioned second positive lens group Gp and the above-mentioned lens group Gp1 .

[0247] The first lens group G1 has positive refractive power. It includes lenses L11 through L13, in order from the object side toward the image side. Lens L11 is a negative meniscus lens with a convex surface facing the object side. Lens L12 is a biconvex positive lens. Lens L13 is a positive meniscus lens with a convex surface facing the object side. Lenses L11 and L12 are attached to each other to form a cemented lens.

[0248] The second lens group G2 has negative refractive power. It includes lenses L21 to L24, in order from the object side toward the image side. Lens L21 is a negative meniscus lens with a convex surface facing the object side. Lens L22 is a biconcave negative lens. Lens L23 is a positive meniscus lens with a convex surface facing the object side. Lens L24 is a biconcave negative lens.

[0249] The third lens group G3 has positive refractive power and includes a lens L31. The lens L31 is a positive meniscus lens having a convex surface facing the object side.

[0250] The fourth lens group G4 has negative refractive power and includes a lens L41 . The lens L41 is a biconcave negative lens.

[0251] The fifth lens group G5 has positive refractive power. It includes, in order from the object side toward the image side, lenses L51 to L54. Lens L51 is a biconvex positive lens. Lens L52 is a biconcave negative lens. Lens L53 is a positive meniscus lens with a convex surface facing the object side. Lens L54 is a biconvex positive lens.

[0252] The sixth lens group G6 has negative refractive power. It includes, in order from the object side toward the image side, lenses L61 through L63. Lens L61 is a negative meniscus lens with a convex surface facing the object side. Lens L62 is a biconvex positive lens. Lens L63 is a biconcave negative lens. Lenses L62 and L63 are attached to each other to form a cemented lens.

[0253] The seventh lens group G7 has positive refractive power. It includes, in order from the object side toward the image side, lenses L71 to L75. Lens L71 is a biconvex positive lens. Lens L72 is a negative meniscus lens with a convex surface facing the image side. Lenses L71 and L72 are attached to each other to form a cemented lens. Lens L73 is a negative meniscus lens with a convex surface facing the object side. Lens L74 is a biconvex positive lens. Lens L75 is a negative meniscus lens with a convex surface facing the image side.

[0254] The above configuration realizes a zoom lens that has a short total optical length while achieving a large aperture larger than that of a lens with an F-number of approximately 2.8 and that can favorably correct various aberrations despite being small in size and light in weight.

[0255] [Table 7]

[0256]

[0257] [Table 8]

[0258]

[0259]

[0260] [Table 9]

[0261]

[0262]

[0263] [Table 10]

[0264]

[0265] [Table 11]

[0266]

[0267] [Table 12]

[0268]

[0269]

[0270] Figure 15 The longitudinal aberration at the time of infinity focusing at the wide-angle end of the zoom lens 2 according to Example 2 is illustrated. Figure 16 The longitudinal aberration at the time of infinity focusing at the middle position of the zoom lens 2 according to Example 2 is illustrated. Figure 17 Illustrated are longitudinal aberrations at the time of infinity focusing at the telephoto end of the zoom lens 2 according to Example 2. Figure 18 Longitudinal aberration at the time of close focusing at the wide-angle end of the zoom lens 2 according to Example 2 is illustrated. Figure 19 The longitudinal aberration at the time of close focusing at the intermediate position of the zoom lens 2 according to Example 2 is illustrated. Figure 20 Longitudinal aberrations at the time of close focusing at the telephoto end of the zoom lens 2 according to Example 2 are illustrated. Figure 21 Illustrated are lateral aberrations at the time of infinity focusing at the wide-angle end of the zoom lens 2 according to Example 2. Figure 22 Illustrated is a lateral aberration at the time of infinity focusing at the middle position of the zoom lens 2 according to Example 2. Figure 23 Illustrated are lateral aberrations at the time of infinity focusing at the telephoto end of the zoom lens 2 according to Example 2. Figure 24 Illustrated are lateral aberrations at the time of close focusing at the wide-angle end of the zoom lens 2 according to Example 2. Figure 25 Illustrated are lateral aberrations at the time of close focusing at an intermediate position of the zoom lens 2 according to Example 2. Figure 26 Illustrated are lateral aberrations at the time of close focusing at the telephoto end of the zoom lens 2 according to Example 2.

[0271] As is understood from each of the aberration diagrams, the zoom lens 2 according to Example 2 favorably corrects various aberrations and thus has excellent image forming performance.

[0272] [Example 3]

[0273] Tables 13 and 14 show Figure 27Table 15 shows the basic lens data of the zoom lens 3 according to Example 3. Table 15 shows the values ​​of the focal length f, F-number, total angle of view 2ω, image height Y, and total optical length L of the entire system in the zoom lens 3 according to Example 3. Table 16 shows data on the surface spacing that varies during zooming and focusing in the zoom lens 3 according to Example 3. Note that Table 15 shows the values ​​at each of the wide-angle end (Wide), the middle position (Mid), and the telephoto end (Tele) when both the photographic distance and the object distance (d0) are infinite. Table 16 shows the values ​​at each of the wide-angle end (Wide), the middle position (Mid), and the telephoto end (Tele) when both the photographic distance and the object distance (d0) are infinite, and when both the photographic distance and the object distance (d0) are close. Table 17 shows the values ​​of the coefficients indicating the shape of the aspherical surfaces in the zoom lens 3 according to Example 3. Table 18 shows the starting surface and focal length (unit: mm) of each of the lens groups of the zoom lens 3 according to Example 3.

[0274] The zoom lens 3 according to Example 3 has a configuration in which the first lens group G1 to the seventh lens group G7 are arranged in order from the object side toward the image plane side. An aperture stop St is provided inside the fifth lens group G5.

[0275] When zooming from the wide-angle end to the telephoto end, the second lens group G2 through the seventh lens group G7 (the final lens group) move, changing the spacing between adjacent lens groups. The first lens group G1 (first positive lens group Gf) remains fixed during zooming. When focusing from infinity to close object distances, the sixth lens group G6 moves toward the image plane along the optical axis.

[0276] In the zoom lens 3 according to Example 3, the first lens group G1 to the fourth lens group G4 constitute the front lens group GA, the fifth lens group G5 including the aperture stop St constitutes the middle lens group Gs, and the sixth lens group G6 and the seventh lens group G7 constitute the rear lens group GB.

[0277] In the zoom lens 3 according to Example 3, the second lens group G2 and the fourth lens group G4 in the front lens group GA correspond to the above-mentioned negative lens group Gn, and the second lens group G2 therein corresponds to the above-mentioned lens group Gn1.

[0278] In the zoom lens 3 according to Example 3, the first lens group G1 in the front lens group GA corresponds to the above-mentioned first positive lens group Gf, and the third lens group G3 corresponds to the above-mentioned second positive lens group Gp and the above-mentioned lens group Gp1 .

[0279] The first lens group G1 has positive refractive power. It includes lenses L11 through L13, in order from the object side toward the image side. Lens L11 is a negative meniscus lens with a convex surface facing the object side. Lens L12 is a biconvex positive lens. Lens L13 is a positive meniscus lens with a convex surface facing the object side. Lenses L11 and L12 are attached to each other to form a cemented lens.

[0280] The second lens group G2 has negative refractive power. It includes lenses L21 to L24, in order from the object side toward the image side. Lens L21 is a negative meniscus lens with a convex surface facing the object side. Lens L22 is a biconcave negative lens. Lens L23 is a positive meniscus lens with a convex surface facing the object side. Lens L24 is a biconcave negative lens.

[0281] The third lens group G3 has positive refractive power and includes a lens L31. The lens L31 is a positive meniscus lens having a convex surface facing the object side.

[0282] The fourth lens group G4 has negative refractive power and includes a lens L41. The lens L41 is a negative meniscus lens having a convex surface facing the object side.

[0283] The fifth lens group G5 has positive refractive power. It includes, in order from the object side toward the image side, lenses L51 to L54. Lens L51 is a biconvex positive lens. Lens L52 is a biconcave negative lens. Lens L53 is a positive meniscus lens with a convex surface facing the object side. Lens L54 is a biconvex positive lens.

[0284] The sixth lens group G6 has negative refractive power. It includes, in order from the object side toward the image side, lens L61 and lens L62. Lens L61 is a biconvex positive lens. Lens L62 is a biconcave negative lens. Lens L61 and lens L62 are attached to each other to form a cemented lens.

[0285] Seventh lens group G7 has positive refractive power. It includes, in order from the object side toward the image side, lenses L71 through L73. Lens L71 is a positive meniscus lens with a convex surface facing the image side. Lens L72 is a negative meniscus lens with a convex surface facing the image side. Lenses L71 and L72 are attached to each other to form a cemented lens. Lens L73 is a negative meniscus lens with a convex surface facing the image side.

[0286] The above configuration realizes a zoom lens that has a short total optical length while achieving a large aperture larger than that of a lens with an F-number of approximately 2.8 and that can favorably correct various aberrations despite being small in size and light in weight.

[0287] [Table 13]

[0288]

[0289]

[0290] [Table 14]

[0291]

[0292]

[0293] [Table 15]

[0294]

[0295] [Table 16]

[0296]

[0297] [Table 17]

[0298]

[0299]

[0300] [Table 18]

[0301]

[0302] Figure 28 The longitudinal aberration at the time of infinity focusing at the wide-angle end of the zoom lens 3 according to Example 3 is illustrated. Figure 29 The longitudinal aberration at the time of infinity focusing at the middle position of the zoom lens 3 according to Example 3 is illustrated. Figure 30 Illustrated are longitudinal aberrations at the time of infinity focusing at the telephoto end of the zoom lens 3 according to Example 3. Figure 31 Longitudinal aberration at the time of close focusing at the wide-angle end of the zoom lens 3 according to Example 3 is illustrated. Figure 32 The longitudinal aberration at the time of close focusing at the intermediate position of the zoom lens 3 according to Example 3 is illustrated. Figure 33 Longitudinal aberrations at the time of close focusing at the telephoto end of the zoom lens 3 according to Example 3 are illustrated. Figure 34 Illustrated are lateral aberrations at the time of infinity focusing at the wide-angle end of the zoom lens 3 according to Example 3. Figure 35 Illustrated are lateral aberrations at the time of infinity focusing at the middle position of the zoom lens 3 according to Example 3. Figure 36 Illustrated are lateral aberrations at the time of infinity focusing at the telephoto end of the zoom lens 3 according to Example 3. Figure 37 Illustrated are lateral aberrations at the time of close focusing at the wide-angle end of the zoom lens 3 according to Example 3. Figure 38Illustrated are lateral aberrations at the time of close focusing at an intermediate position of the zoom lens 3 according to Example 3. Figure 39 Illustrated are lateral aberrations at the time of close focusing at the telephoto end of the zoom lens 3 according to Example 3.

[0303] As is understood from each of the aberration diagrams, the zoom lens 3 according to Example 3 favorably corrects various aberrations and thus has excellent image forming performance.

[0304] [Example 4]

[0305] Tables 19 and 20 show Figure 40 Table 21 shows the basic lens data of the zoom lens 4 according to Example 4. Table 21 shows the values ​​of the focal length f, F-number, total angle of view 2ω, image height Y, and total optical length L of the entire system in the zoom lens 4 according to Example 4. Table 22 shows data on the variable surface spacing during zooming and focusing in the zoom lens 4 according to Example 4. Note that Table 21 shows the values ​​at each of the wide-angle end (Wide), the middle position (Mid), and the telephoto end (Tele) when both the photographic distance and the object distance (d0) are infinite. Table 22 shows the values ​​at each of the wide-angle end (Wide), the middle position (Mid), and the telephoto end (Tele) when both the photographic distance and the object distance (d0) are infinite, and when both the photographic distance and the object distance (d0) are close. Table 23 shows the values ​​of the coefficients indicating the aspherical surface shape in the basic lens data of the zoom lens 4 according to Example 4. Table 24 shows the starting surface and focal length (unit: mm) of each of the lens groups of the zoom lens 4 according to Example 4.

[0306] The zoom lens 4 according to Example 4 has a configuration in which the first lens group G1 to the eighth lens group G8 are arranged in order from the object side toward the image plane side. An aperture stop St is provided inside the fifth lens group G5.

[0307] When zooming from the wide-angle end to the telephoto end, the second lens group G2 through the eighth lens group G8 (the final lens group) move, changing the spacing between adjacent lens groups. The first lens group G1 (first positive lens group Gf) remains fixed during zooming. When focusing from infinity to close object distances, the sixth lens group G6 and the seventh lens group G7 move toward the image plane along the optical axis.

[0308] In the zoom lens 4 according to Example 4, the first lens group G1 to the fourth lens group G4 constitute the front lens group GA, the fifth lens group G5 including the aperture stop St constitutes the middle lens group Gs, and the sixth lens group G6 to the eighth lens group G8 constitute the rear lens group GB.

[0309] In the zoom lens 4 according to Example 4, the second lens group G2 in the front lens group GA corresponds to the above-mentioned negative lens group Gn and lens group Gn1 .

[0310] In the zoom lens 4 according to Example 4, the first lens group G1 in the front lens group GA corresponds to the above-mentioned first positive lens group Gf, the third lens group G3 and the fourth lens group G4 correspond to the above-mentioned second positive lens group Gp, and the fourth lens group G4 corresponds to the above-mentioned lens group Gp1.

[0311] The first lens group G1 has positive refractive power. It includes lenses L11 through L13, in order from the object side toward the image side. Lens L11 is a negative meniscus lens with a convex surface facing the object side. Lens L12 is a positive meniscus lens with a convex surface facing the object side. Lens L13 is a positive meniscus lens with a convex surface facing the object side. Lenses L11 and L12 are attached to each other to form a cemented lens.

[0312] The second lens group G2 has negative refractive power. It includes, in order from the object side toward the image side, lens L21 and lens L22. Lens L21 is a biconcave negative lens. Lens L22 is a positive meniscus lens with a convex surface facing the object side.

[0313] The third lens group G3 has positive refractive power and includes a lens L31. The lens L31 is a positive meniscus lens having a convex surface facing the object side.

[0314] The fourth lens group G4 has positive refractive power. It includes, in order from the object side toward the image side, lenses L41 through L43. Lens L41 is a negative meniscus lens with a convex surface facing the object side. Lens L42 is a biconvex positive lens. Lens L43 is a biconcave negative lens. Lenses L41 and L42 are attached to each other to form a cemented lens.

[0315] The fifth lens group G5 has positive refractive power. The fifth lens group G5 includes, in order from the object side toward the image side, lenses L51 to L55. Lens L51 is a negative meniscus lens with a convex surface facing the object side. Lens L52 is a negative meniscus lens with a convex surface facing the object side. Lens L53 is a biconvex positive lens. Lens L52 and lens L53 are attached to each other to form a cemented lens. Lens L54 is a negative meniscus lens with a convex surface facing the object side. Lens L55 is a biconvex positive lens.

[0316] The sixth lens group G6 has negative refractive power. It includes, in order from the object side toward the image side, lenses L61 through L63. Lens L61 is a negative meniscus lens with a convex surface facing the object side. Lens L62 is a negative meniscus lens with a convex surface facing the object side. Lens L63 is a biconvex positive lens.

[0317] The seventh lens group G7 has negative refractive power. It includes, in order from the object side toward the image side, lenses L71 to L74. Lens L71 is a negative meniscus lens with a convex surface facing the object side. Lens L72 is a positive meniscus lens with a convex surface facing the image side. Lens L73 is a negative meniscus lens with a convex surface facing the image side. Lens L74 is a negative meniscus lens with a convex surface facing the image side.

[0318] The eighth lens group G8 has positive refractive power. It includes, in order from the object side toward the image side, lenses L81 to L84. Lens L81 is a biconvex positive lens. Lens L82 is a biconvex positive lens. Lens L83 is a biconcave negative lens. Lens L84 is a negative meniscus lens with a convex surface facing the object side.

[0319] The above configuration realizes a zoom lens that has a short total optical length while achieving a large aperture larger than that of a lens with an F-number of approximately 2.8 and that can favorably correct various aberrations despite being small in size and light in weight.

[0320] [Table 19]

[0321]

[0322] [Table 20]

[0323]

[0324]

[0325]

[0326] [Table 21]

[0327]

[0328] [Table 22]

[0329]

[0330] [Table 23]

[0331]

[0332]

[0333] [Table 24]

[0334]

[0335]

[0336] Figure 41 The longitudinal aberration at the time of infinity focusing at the wide-angle end of the zoom lens 4 according to Example 4 is illustrated. Figure 42 The longitudinal aberration at the time of infinity focusing at the middle position of the zoom lens 4 according to Example 4 is illustrated. Figure 43 Illustrated are longitudinal aberrations at the time of infinity focusing at the telephoto end of the zoom lens 4 according to Example 4. Figure 44 Longitudinal aberration at the time of close focusing at the wide-angle end of the zoom lens 4 according to Example 4 is illustrated. Figure 45 The longitudinal aberration at the time of close focusing at the intermediate position of the zoom lens 4 according to Example 4 is illustrated. Figure 46 Longitudinal aberrations at the time of close focusing at the telephoto end of the zoom lens 4 according to Example 4 are illustrated. Figure 47 Illustrated is a lateral aberration at the time of infinity focusing at the wide-angle end of the zoom lens 4 according to Example 4. Figure 48 The diagram illustrates lateral aberration at the time of infinity focusing at the middle position of the zoom lens 4 according to Example 4. Figure 49 Illustrated are lateral aberrations at the time of infinity focusing at the telephoto end of the zoom lens 4 according to Example 4. Figure 50 Illustrated are lateral aberrations at the time of close focusing at the wide-angle end of the zoom lens 4 according to Example 4. Figure 51 The diagram illustrates lateral aberration at close focusing at an intermediate position of the zoom lens 4 according to Example 4. Figure 52 Illustrated are lateral aberrations at the time of close focusing at the telephoto end of the zoom lens 4 according to Example 4.

[0337] As is understood from each of the aberration diagrams, the zoom lens 4 according to Example 4 favorably corrects various aberrations and thus has excellent image forming performance.

[0338] [Example 5]

[0339] Tables 25 and 26 show Figure 53Table 27 shows the basic lens data of the zoom lens 5 according to Example 5. Table 27 shows the values ​​of the focal length f, F-number, total angle of view 2ω, image height Y, and total optical length L of the entire system in the zoom lens 5 according to Example 5. Table 28 shows data on the variable surface spacing during zooming and focusing in the zoom lens 5 according to Example 5. Note that Table 27 shows the values ​​at each of the wide-angle end (Wide), the middle position (Mid), and the telephoto end (Tele) when both the photographic distance and the object distance (d0) are infinite. Table 28 shows the values ​​at each of the wide-angle end (Wide), the middle position (Mid), and the telephoto end (Tele) when both the photographic distance and the object distance (d0) are infinite, and when both the photographic distance and the object distance (d0) are close. Table 29 shows the values ​​of the coefficients indicating the shape of the aspherical surfaces in the zoom lens 5 according to Example 5. Table 30 shows the starting surface and focal length (unit: mm) of each of the lens groups of the zoom lens 5 according to Example 5.

[0340] The zoom lens 5 according to Example 5 has a configuration in which the first lens group G1 to the eighth lens group G8 are arranged in order from the object side toward the image plane side. An aperture stop St is provided inside the fifth lens group G5.

[0341] When zooming from the wide-angle end to the telephoto end, the second lens group G2 through the eighth lens group G8 (the final lens group) move, changing the spacing between adjacent lens groups. The first lens group G1 (first positive lens group Gf) remains fixed during zooming. When focusing from infinity to close object distances, the sixth lens group G6 and the seventh lens group G7 move toward the object along the optical axis.

[0342] In the zoom lens 5 according to Example 5, the first lens group G1 to the fourth lens group G4 constitute the front lens group GA, the fifth lens group G5 including the aperture stop St constitutes the middle lens group Gs, and the sixth lens group G6 to the eighth lens group G8 constitute the rear lens group GB.

[0343] In the zoom lens 5 according to Example 5, the second lens group G2 in the front lens group GA corresponds to the above-mentioned negative lens group Gn and lens group Gn1 .

[0344] In the zoom lens 5 according to Example 5, the first lens group G1 in the front lens group GA corresponds to the above-mentioned first positive lens group Gf, and the third lens group G3 and the fourth lens group G4 correspond to the above-mentioned second positive lens group Gp, and the fourth lens group G4 corresponds to the above-mentioned lens group Gp1.

[0345] The first lens group G1 has positive refractive power. It includes lenses L11 through L13, in order from the object side toward the image side. Lens L11 is a negative meniscus lens with a convex surface facing the object side. Lens L12 is a biconvex positive lens. Lens L13 is a positive meniscus lens with a convex surface facing the object side. Lenses L11 and L12 are attached to each other to form a cemented lens.

[0346] The second lens group G2 has negative refractive power. It includes lenses L21 through L23, in order from the object side toward the image side. Lens L21 is a biconcave negative lens. Lens L22 is a biconcave negative lens. Lens L23 is a biconvex positive lens. Lenses L22 and L23 are attached to each other to form a cemented lens.

[0347] The third lens group G3 has positive refractive power. It includes, in order from the object side toward the image side, lens L31 and lens L32. Lens L31 is a negative meniscus lens with a convex surface facing the object side. Lens L32 is a positive meniscus lens with a convex surface facing the object side.

[0348] The fourth lens group G4 has positive refractive power. It includes, in order from the object side toward the image side, lenses L41 through L43. Lens L41 is a biconvex positive lens. Lens L42 is a negative meniscus lens with a convex surface facing the image side. Lens L43 is a negative meniscus lens with a convex surface facing the image side. Lenses L41 and L42 are attached to each other to form a cemented lens.

[0349] The fifth lens group G5 has positive refractive power. It includes, in order from the object side toward the image side, lenses L51 to L55. Lens L51 is a biconvex positive lens. Lens L52 is a negative meniscus lens with a convex surface facing the object side. Lens L53 is a biconcave negative lens. Lens L54 is a positive meniscus lens with a convex surface facing the image side. Lens L55 is a negative meniscus lens with a convex surface facing the object side.

[0350] The sixth lens group G6 has positive refractive power. It includes, in order from the object side toward the image side, lenses L61 through L63. Lens L61 is a positive meniscus lens with a convex surface facing the object side. Lens L62 is a biconcave negative lens. Lens L63 is a biconvex positive lens.

[0351] The seventh lens group G7 has positive refractive power. It includes, in order from the object side to the image side, lenses L71 to L75. Lens L71 is a negative meniscus lens with a convex surface facing the object side. Lens L72 is a negative meniscus lens with a convex surface facing the image side. Lens L73 is a biconvex positive lens. Lens L74 is a positive meniscus lens with a convex surface facing the image side. Lens L75 is a negative meniscus lens with a convex surface facing the image side.

[0352] The eighth lens group G8 has negative refractive power and includes a lens L81. The lens L81 is a biconcave negative lens.

[0353] The above configuration realizes a zoom lens that has a short total optical length while achieving a large aperture larger than that of a lens with an F-number of approximately 2.8 and that can favorably correct various aberrations despite being small in size and light in weight.

[0354] [Table 25]

[0355]

[0356]

[0357] [Table 26]

[0358]

[0359]

[0360] [Table 27]

[0361]

[0362]

[0363] [Table 28]

[0364]

[0365] [Table 29]

[0366]

[0367]

[0368] [Table 30]

[0369]

[0370] Figure 54 The longitudinal aberration at the time of infinity focusing at the wide-angle end of the zoom lens 5 according to Example 5 is illustrated. Figure 55The longitudinal aberration at the time of infinity focusing at the middle position of the zoom lens 5 according to Example 5 is illustrated. Figure 56 The longitudinal aberration at the time of infinity focusing at the telephoto end of the zoom lens 5 according to Example 5 is illustrated. Figure 57 Longitudinal aberrations at the time of close focusing at the wide-angle end of the zoom lens 5 according to Example 5 are illustrated. Figure 58 The longitudinal aberration at the time of close focusing at the intermediate position of the zoom lens 5 according to Example 5 is illustrated. Figure 59 Longitudinal aberration at the time of close focusing at the telephoto end of the zoom lens 5 according to Example 5 is illustrated. Figure 60 Illustrated are lateral aberrations at the time of infinity focusing at the wide-angle end of the zoom lens 5 according to Example 5. Figure 61 The diagram illustrates lateral aberration at the time of infinity focusing at the middle position of the zoom lens 5 according to Example 5. Figure 62 Illustrated are lateral aberrations at the time of infinity focusing at the telephoto end of the zoom lens 5 according to Example 5. Figure 63 Illustrated are lateral aberrations at the time of close focusing at the wide-angle end of the zoom lens 5 according to Example 5. Figure 64 The diagram illustrates lateral aberration at close focusing at an intermediate position of the zoom lens 5 according to Example 5. Figure 65 Illustrated are lateral aberrations at the time of close focusing at the telephoto end of the zoom lens 5 according to Example 5.

[0371] As is understood from each of the aberration diagrams, the zoom lens 5 according to Example 5 favorably corrects various aberrations and thus has excellent image forming performance.

[0372] [Additional numerical data for each instance]

[0373] Table 31 and Table 32 summarize the values ​​associated with the above-mentioned corresponding conditional expressions for each of the examples. As can be understood from Table 32, the values ​​of each of the examples fall within the corresponding numerical ranges of these conditional expressions.

[0374] [Table 31]

[0375]

[0376]

[0377] [Table 32]

[0378]

[0379]

[0380] <5. Practical Application Examples>

[0381] [5.1 First practical application example]

[0382] The technology according to the present disclosure is applicable to various products. For example, the technology according to the present disclosure can be implemented as a device to be installed on any type of movable body, such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, a personal mobility device, an airplane, an unmanned aerial vehicle, a ship, a robot, a construction machine, an agricultural machine (tractor), etc.

[0383] Figure 67 7000 is a block diagram illustrating a schematic configuration example of a vehicle control system 7000 as an example of a mobile body control system to which the technology according to an embodiment of the present disclosure can be applied. The vehicle control system 7000 includes a plurality of electric control units connected to each other via a communication network 7010. Figure 67 In the example depicted in FIG, a vehicle control system 7000 includes a drive system control unit 7100, a body system control unit 7200, a battery control unit 7300, a vehicle exterior information detection unit 7400, a vehicle interior information detection unit 7500, and an integrated control unit 7600. For example, a communication network 7010 connecting the plurality of control units to each other may be an in-vehicle communication network compliant with any standard such as a controller area network (CAN), a local interconnect network (LIN), a local area network (LAN), FlexRay (registered trademark), or the like.

[0384] Each control unit includes a microcomputer that performs arithmetic processing according to various programs; a storage unit that stores programs executed by the microcomputer, parameters for various operations, and the like; and a drive circuit that drives various control target devices. Each control unit also includes a network interface (I / F) for communicating with other control units via the communication network 7010; and a communication I / F for communicating with devices, sensors, and the like inside and outside the vehicle via wired or radio communication. Figure 67 The functional configuration of the integrated control unit 7600 shown in FIG. 7 includes a microcomputer 7610, a general-purpose communication I / F 7620, a dedicated communication I / F 7630, a positioning unit 7640, a beacon receiving unit 7650, an in-vehicle device I / F 7660, a sound / image output unit 7670, an in-vehicle network I / F 7680, and a storage unit 7690. Other control units similarly include a microcomputer, a communication I / F, a storage unit, and the like.

[0385] The drive system control unit 7100 controls the operation of devices related to the vehicle's drive system according to various programs. For example, the drive system control unit 7100 functions as a control device for a drive force generating device such as an internal combustion engine or a drive motor that generates the vehicle's drive force, a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the vehicle's steering angle, a braking device for generating the vehicle's braking force, and the like. The drive system control unit 7100 may also function as a control device for an anti-lock braking system (ABS), an electronic stability control (ESC), and the like.

[0386] Drive system control unit 7100 is connected to vehicle state detection unit 7110. For example, vehicle state detection unit 7110 includes at least one of a gyro sensor for detecting the angular velocity of the axial rotational movement of the vehicle body, an acceleration sensor for detecting vehicle acceleration, and sensors for detecting the amount of accelerator pedal operation, the amount of brake pedal operation, the steering angle of the steering wheel, the engine speed, the wheel rotation speed, and the like. Drive system control unit 7100 uses the signals input from vehicle state detection unit 7110 to perform arithmetic processing and control the internal combustion engine, drive motor, electric power steering system, braking system, and the like.

[0387] The body system control unit 7200 controls the operation of various devices provided to the vehicle body according to various programs. For example, the body system control unit 7200 functions as a control device for a keyless entry system, a smart key system, power windows, or various types of lights such as headlights, backup lights, brake lights, turn signals, fog lights, etc. In this case, radio waves transmitted from a mobile device that replaces the key or signals from various switches may be input to the body system control unit 7200. The body system control unit 7200 receives these input radio waves or signals and controls the vehicle's door locks, power windows, lights, etc.

[0388] The battery control unit 7300 controls the secondary battery 7310, which serves as a power supply source for driving the motor, according to various programs. For example, the battery control unit 7300 receives information about battery temperature, battery output voltage, remaining battery capacity, and the like from the battery device including the secondary battery 7310. The battery control unit 7300 performs arithmetic processing using these signals and controls the temperature of the secondary battery 7310 or controls a cooling device provided for the battery device.

[0389] The vehicle exterior information detection unit 7400 detects information about the exterior of the vehicle including the vehicle control system 7000. For example, the vehicle exterior information detection unit 7400 is connected to at least one of the imaging unit 7410 and the vehicle exterior information detection unit 7420. The imaging unit 7410 includes at least one of a time-of-flight (ToF) camera, a stereo camera, a monocular camera, an infrared camera, or other cameras. For example, the vehicle exterior information detection unit 7420 includes at least one of an environmental sensor for detecting current atmospheric or weather conditions and a peripheral information detection sensor for detecting another vehicle, obstacles, pedestrians, etc. around the vehicle including the vehicle control system 7000.

[0390] For example, the environmental sensor may be at least one of a rainfall sensor for detecting rain, a fog sensor for detecting fog, a sunshine sensor for detecting the degree of sunshine, and a snow sensor for detecting snowfall. The peripheral information detection sensor may be at least one of an ultrasonic sensor, a radar device, and a LIDAR device (a light detection and ranging device, or a laser imaging detection and ranging device). Each of the imaging unit 7410 and the vehicle exterior information detection unit 7420 may be configured as an independent sensor or device, or may be configured as a device in which multiple sensors or devices are integrated.

[0391] Figure 68 The figure depicts examples of installation locations for the imaging unit 7410 and the vehicle exterior information detection unit 7420. For example, the imaging units 7910, 7912, 7914, 7916, and 7918 are located on at least one of the front nose, side mirrors, rear bumper, and rear door of the vehicle 7900, or on the upper portion of the windshield within the vehicle interior. The imaging unit 7910 located on the front nose and the imaging unit 7918 located on the upper portion of the windshield within the vehicle interior primarily capture images in front of the vehicle 7900. The imaging units 7912 and 7914 located on the side mirrors primarily capture images from the sides of the vehicle 7900. The imaging unit 7916 located on the rear bumper or rear door primarily captures images from behind the vehicle 7900. The imaging unit 7918 located on the upper portion of the windshield within the vehicle interior primarily detects preceding vehicles, pedestrians, obstacles, signals, traffic signs, lanes, and the like.

[0392] By the way, Figure 68The figure shows examples of the imaging ranges of the respective imaging units 7910, 7912, 7914, and 7916. Imaging range a represents the imaging range of imaging unit 7910, which is located at the front nose. Imaging ranges b and c represent the imaging ranges of imaging units 7912 and 7914, respectively, located at the side mirrors. Imaging range d represents the imaging range of imaging unit 7916, which is located at the rear bumper or rear door. For example, a bird's-eye view image of vehicle 7900 viewed from above can be obtained by superimposing image data captured by imaging units 7910, 7912, 7914, and 7916.

[0393] For example, the vehicle exterior information detection units 7920, 7922, 7924, 7926, 7928, and 7930 located at the front, rear, sides, and corners of the vehicle 7900, as well as the upper portion of the windshield within the vehicle interior, may be ultrasonic sensors or radar devices. For example, the vehicle exterior information detection units 7920, 7926, and 7930 located at the front nose, rear bumper, rear door, and upper portion of the windshield within the vehicle interior of the vehicle 7900 may be LIDAR devices. These vehicle exterior information detection units 7920 to 7930 are primarily used to detect preceding vehicles, pedestrians, obstacles, and the like.

[0394] return Figure 67 , will continue to describe. The vehicle external information detection unit 7400 causes the imaging unit 7410 to image the outside of the vehicle and receive the imaged image data. In addition, the vehicle external information detection unit 7400 receives detection information from the vehicle external information detection unit 7420 connected to the vehicle external information detection unit 7400. In the case where the vehicle external information detection unit 7420 is an ultrasonic sensor, a radar device, or a LIDAR device, the vehicle external information detection unit 7400 transmits ultrasonic waves, electromagnetic waves, etc., and receives information of the received reflected waves. Based on the received information, the vehicle external information detection unit 7400 can perform processing for detecting objects such as people, vehicles, obstacles, signs, characters on the road surface, etc., or processing for detecting the distance thereto. The vehicle external information detection unit 7400 can perform environmental recognition processing for identifying rainfall, fog, road conditions, etc. based on the received information. The vehicle external information detection unit 7400 can calculate the distance to objects outside the vehicle based on the received information.

[0395] In addition, based on the received image data, the vehicle exterior information detection unit 7400 can perform image recognition processing to identify people, vehicles, obstacles, signs, characters on the road surface, etc., or detect the distance thereto. The vehicle exterior information detection unit 7400 can subject the received image data to processing such as distortion correction and alignment, and combine image data imaged by multiple different imaging units 7410 to generate a bird's-eye view image or a panoramic image. The vehicle exterior information detection unit 7400 can perform viewpoint conversion processing using image data imaged by the imaging unit 7410 including different imaging units.

[0396] The vehicle interior information detection unit 7500 detects information about the interior of the vehicle. For example, the vehicle interior information detection unit 7500 is connected to a driver state detection unit 7510 that detects the driver's state. The driver state detection unit 7510 may include a camera that images the driver, a biosensor that detects the driver's biometric information, a microphone that collects sounds inside the vehicle, and the like. For example, the biosensor is set in a seat surface, a steering wheel, etc., and detects the biometric information of an occupant sitting in the seat or a driver holding the steering wheel. Based on the detection information input from the driver state detection unit 7510, the vehicle interior information detection unit 7500 can calculate the driver's fatigue level or the driver's concentration level, or can determine whether the driver is dozing off. The vehicle interior information detection unit 7500 can subject the audio signal obtained by collecting the sound to processing such as noise cancellation processing and the like.

[0397] The integrated control unit 7600 controls the overall operation within the vehicle control system 7000 according to various programs. The integrated control unit 7600 is connected to the input unit 7800. The input unit 7800 is implemented by a device that allows the occupant to perform input operations, such as a touch panel, buttons, microphone, switch, lever, etc., and the integrated control unit 7600 can be supplied with data obtained through voice recognition of voice input through the microphone. For example, the input unit 7800 can be a remote control device using infrared or other radio waves, or an externally connected device such as a mobile phone or personal digital assistant (PDA) that supports the operation of the vehicle control system 7000. The input unit 7800 can be, for example, a camera. In this case, the passenger can input information using gestures. Alternatively, data obtained by detecting the movement of a wearable device worn by the occupant can be input. In addition, the input unit 7800 can include, for example, an input control circuit that uses the above-mentioned input unit 7800 to generate an input signal based on the information input by the occupant and outputs the generated input signal to the integrated control unit 7600. The occupants and the like input various data or give instructions for processing operations to the vehicle control system 7000 through the operation input unit 7800 .

[0398] The storage unit 7690 may include a read-only memory (ROM) that stores various programs executed by the microcomputer and a random access memory (RAM) that stores various parameters, operation results, sensor values, etc. In addition, the storage unit 7690 may be implemented by a magnetic storage device such as a hard disk drive (HDD), a semiconductor storage device, an optical storage device, a magneto-optical storage device, or the like.

[0399] The general communication I / F 7620 is a widely used communication I / F that mediates communications with various devices present in the external environment 7750. The general communication I / F 7620 can implement cellular communication protocols such as Global System for Mobile Communications (GSM (registered trademark)), Worldwide Interoperability for Microwave Access (WiMAX (registered trademark)), Long Term Evolution (LTE (registered trademark)), LTE-Advanced (LTE-A), or other wireless communication protocols such as wireless LAN (also known as Wireless Fidelity (Wi-Fi (registered trademark)) and Bluetooth (registered trademark). The general communication I / F 7620 can connect to devices (e.g., application servers or control servers) present on an external network (e.g., the Internet, a cloud network, or a company-specific network) via, for example, a base station or access point. Furthermore, the general communication I / F 7620 can connect to terminals present near the vehicle (e.g., terminals of the driver, pedestrians, or stores, or machine type communication (MTC) terminals) using, for example, peer-to-peer (P2P) technology.

[0400] Dedicated communication I / F 7630 is a communication I / F that supports communication protocols developed for use in vehicles. Dedicated communication I / F 7630 can implement a standard protocol such as (for example) Wireless Access in Vehicular Environments (WAVE) or a cellular communication protocol, such as a combination of Institute of Electrical and Electronics Engineers (IEEE) 802.11p as a lower layer and IEEE 1609 as a higher layer, dedicated short-range communication (DSRC), or a cellular communication protocol. Dedicated communication I / F 7630 typically implements V2X communication as a concept that includes one or more of vehicle-to-vehicle communication (vehicle-to-vehicle), road-to-vehicle communication (vehicle-to-infrastructure), vehicle-to-residence communication (vehicle-to-residence), and pedestrian-to-vehicle communication (vehicle-to-pedestrian).

[0401] The positioning unit 7640 performs positioning by, for example, receiving a global navigation satellite system (GNSS) signal from a GNSS satellite (e.g., receiving a GPS signal from a global positioning system (GPS) satellite) and generates position information including the latitude, longitude, and altitude of the vehicle. Incidentally, the positioning unit 7640 may identify the current position by exchanging signals with a wireless access point, or may obtain position information from a terminal such as a mobile phone, a personal handyphone system (PHS), or a smartphone having a positioning function.

[0402] The beacon receiving unit 7650 receives, for example, radio waves or electromagnetic waves transmitted from a radio station installed on a road or the like, thereby obtaining information on the current position, congestion, closed roads, necessary time, etc. Incidentally, the function of the beacon receiving unit 7650 may be included in the above-mentioned dedicated communication I / F 7630.

[0403] The in-vehicle device I / F 7660 is a communication interface that mediates the connection between the microcomputer 7610 and various in-vehicle devices 7760 present in the vehicle. The in-vehicle device I / F 7660 can establish a wireless connection using a wireless communication protocol such as wireless LAN, Bluetooth (registered trademark), near field communication (NFC), or wireless universal serial bus (WUSB). In addition, the in-vehicle device I / F 7660 can establish a wired connection via a universal serial bus (USB), a high-definition multimedia interface (HDMI) (registered trademark), or a mobile high-definition link (MHL) via a connection terminal (if necessary, a cable) not depicted in the figure. For example, the in-vehicle device 7760 may include at least one of a mobile device and a wearable device owned by an occupant, and an information device carried in or attached to the vehicle. The in-vehicle device 7760 may also include a navigation device that searches for a route to an arbitrary destination. The in-vehicle device I / F 7660 exchanges control signals or data signals with these in-vehicle devices 7760.

[0404] The in-vehicle network I / F 7680 is an interface that mediates communication between the microcomputer 7610 and the communication network 7010. The in-vehicle network I / F 7680 transmits and receives signals and the like in accordance with a predetermined protocol supported by the communication network 7010.

[0405] The microcomputer 7610 of the integrated control unit 7600 controls the vehicle control system 7000 according to various programs based on information obtained via at least one of the general communication I / F 7620, the dedicated communication I / F 7630, the positioning unit 7640, the beacon receiving unit 7650, the in-vehicle device I / F 7660, or the in-vehicle network I / F 7680. For example, the microcomputer 7610 can calculate control target values ​​for the driving force generating device, the steering mechanism, or the braking device based on the information obtained about the interior and exterior of the vehicle, and output control commands to the drive system control unit 7100. For example, the microcomputer 7610 can perform cooperative control to implement advanced driver assistance system (ADAS) functions, such as collision avoidance or shock absorption of the vehicle, follow-up driving based on following distance, vehicle speed maintenance driving, vehicle collision warning, vehicle lane departure warning, and the like. In addition, microcomputer 7610 can perform cooperative control intended for autonomous driving, which controls the driving force generating device, steering mechanism, braking device, etc. based on information obtained about the vehicle's surroundings, allowing the vehicle to travel automatically without relying on driver operation, etc.

[0406] Based on information obtained via at least one of the general communication I / F 7620, the dedicated communication I / F 7630, the positioning unit 7640, the beacon receiving unit 7650, the in-vehicle device I / F 7660, and the in-vehicle network I / F 7680, the microcomputer 7610 can generate three-dimensional distance information between the vehicle and objects such as surrounding structures and people, and also generate local map information including information about the surroundings of the vehicle's current location. Furthermore, based on the obtained information, the microcomputer 7610 can predict dangers such as vehicle collisions, approaching pedestrians, or entering closed roads, and generate warning signals. For example, the warning signal can generate a warning sound or illuminate a warning light.

[0407] The sound / image output unit 7670 transmits an output signal of at least one of sound and image to an output device capable of visually or auditorily notifying the occupants of the vehicle or the outside of the vehicle of information. Figure 67In the example of , an audio speaker 7710, a display unit 7720, and an instrument panel 7730 are illustrated as output devices. The display unit 7720 may, for example, include at least one of an on-board display and a head-up display. The display unit 7720 may have an augmented reality (AR) display function. The output device may be a device different from these devices, and may be another device such as headphones, a wearable device (such as a glasses-type display worn by an occupant), a projector, a lamp, etc. In the case where the output device is a display device, the display device visually displays the results obtained by various processes performed by the microcomputer 7610 or information received from another control unit in various forms such as text, images, tables, graphics, etc. In addition, in the case where the output device is an audio output device, the audio output device converts an audio signal consisting of reproduced audio data or sound data, etc. into an analog signal and audibly outputs the analog signal.

[0408] Incidentally, in Figure 67 In the example depicted in the figure, at least two control units connected to each other via the communication network 7010 can be integrated into one control unit. Alternatively, each individual control unit may include multiple control units. In addition, the vehicle control system 7000 may include another control unit not depicted in the figure. In addition, part or all of the functions performed by one of the control units described above may be assigned to another control unit. That is, as long as information is sent and received via the communication network 7010, predetermined arithmetic processing can be performed by any control unit. Similarly, a sensor or device connected to one of the control units can be connected to another control unit, and multiple control units can send and receive detection information to each other via the communication network 7010.

[0409] In the above-mentioned vehicle control system 7000 , the zoom lens and the imaging device of the present disclosure are applicable to the imaging section 7410 and any one of the imaging sections 7910 , 7912 , 7914 , 7916 , and 7918 .

[0410] [5.2 Second practical application example]

[0411] The technology according to the present disclosure is applicable to a medical imaging system, which is a medical system using imaging technology, such as an endoscope system or a microscope system.

[0412] [Endoscope System]

[0413] Will use Figure 69 and Figure 70 An example of an endoscope system is described. Figure 69 is a diagram illustrating a schematic configuration example of an endoscope system 5000 to which the technology according to the present disclosure is applied. Figure 7050 is a diagram illustrating a configuration example of an endoscope 5001 and a camera control unit (CCU) 5039 .

[0414] Figure 69 The figure shows a situation where an operator (eg, doctor) 5067 as a surgical participant uses an endoscope system 5000 to perform surgery on a patient 5071 on a bed 5069. Figure 69 As illustrated in FIG, an endoscope system 5000 includes an endoscope 5001 as a medical imaging device, a CCU 5039, a light source device 5043, a recording device 5053, an output device 5055, and a support device 5027 for supporting the endoscope 5001.

[0415] In endoscopic surgery, an insertion aid tool called a trocar 5025 is inserted into the body of a patient 5071. Then, an observation instrument 5003 connected to the endoscope 5001 and surgical tools 5021 are inserted into the body of the patient 5071 through the trocar 5025. For example, the surgical tools 5021 include: an energy device such as an electric scalpel; and forceps.

[0416] A surgical image, which is a medical image captured through an endoscope 5001 from inside the body of a patient 5071, is displayed on a display device 5041. An operator 5067 performs surgery on a surgical target using a surgical tool 5021 while observing the surgical image displayed on the display device 5041. The medical image is not limited to a surgical image and may be a diagnostic image captured during diagnosis.

[0417] [Endoscope]

[0418] The endoscope 5001 is an imaging portion for capturing the inside of the body of the patient 5071, and for example, Figure 70, a camera includes a converging optical system 50051 for converging incident light, a zoom optical system 50052 capable of optical zooming by changing the focal length of the imaging unit, a focusing optical system 50053 capable of adjusting the focus by changing the focal length of the imaging unit, and a light receiving sensor 50054. The endoscope 5001 converges light passing through a connected scope 5003 onto the light receiving sensor 50054 to generate pixel signals, and outputs the pixel signals to the CCU 5039 via a transmission system. The scope 5003 is an insertable component that includes an objective lens at its distal end and guides light from a connected light source device 5043 into the body of a patient 5071. For example, the scope 5003 can be a rigid scope for a rigid endoscope or a flexible endoscope for a flexible endoscope. The scope 5003 can be a direct-view scope or an inclined-view scope. The pixel signals only need to be based on signals output from the pixels, and can be, for example, raw signals or image signals. The transmission system that connects the endoscope 5001 to the CCU 5039 may include a memory, and the memory may store parameters related to the endoscope 5001 and the CCU 5039. The memory may be provided at a connection portion of the transmission system or on a cable. For example, the memory of the transmission system may store parameters before the endoscope 5001 is shipped or parameters that change when current is applied, and the operation of the endoscope may be changed based on the parameters read from the memory. The set of the camera and the transmission system may be referred to as an endoscope. The light receiving sensor 50054 is a sensor for converting received light into a pixel signal, and is, for example, a complementary metal oxide semiconductor (CMOS) imaging sensor. The light receiving sensor 50054 is preferably an imaging sensor having a Bayer array capable of color imaging. The light receiving sensor 50054 is also preferably an imaging sensor having a number of pixels corresponding to a resolution of, for example, 4K (3840 horizontal pixels × 2160 vertical pixels), 8K (7680 horizontal pixels × 4320 vertical pixels), or square 4K (3840 or more horizontal pixels × 3840 or more vertical pixels). The light receiving sensor 50054 can be a sensor chip or multiple sensor chips. For example, a prism can be provided to separate the incident light into predetermined wavelength bands, and the wavelength bands can be imaged by different light receiving sensors. Multiple light receiving sensors can be provided for stereoscopic observation. The light receiving sensor 50054 can be a sensor having a chip structure including an arithmetic processing circuit for image processing, or can be a sensor for time of flight (ToF). For example, the transmission system is a fiber optic cable system or a wireless transmission system. Wireless transmission only needs to be able to transmit the pixel signal generated by the endoscope 5001, and for example, the endoscope 5001 can be wirelessly connected to the CCU 5039, or the endoscope 5001 can be connected to the CCU 5039 via a base station in the operating room.At this time, the endoscope 5001 can transmit not only pixel signals but also information related to the pixel signals (e.g., processing priority of pixel signals and / or synchronization signals). In the endoscope, the scope can be integrated with the camera, and the light receiving sensor is provided at the distal end of the scope.

[0419] [Camera Control Unit (CCU)]

[0420] The CCU 5039 is a control device for controlling the endoscope 5001 and the light source device 5043 connected to the CCU 5039 in an integrated manner, and for example, Figure 70 3 , an image processing device including a field programmable gate array (FPGA) 50391, a central processing unit (CPU) 50392, a random access memory (RAM) 50393, a read-only memory (ROM) 50394, a graphics processing unit (GPU) 50395, and an interface (I / F) 50396 is shown. The CCU 5039 can control the display device 5041, the recording device 5053, and the output device 5055 connected to the CCU 5039 in an integrated manner. The CCU 5039 controls, for example, the illumination timing, illumination intensity, and type of illumination light source of the light source device 5043. The CCU 5039 also performs image processing such as development processing (e.g., demosaicing processing) and correction processing on the pixel signals output from the endoscope 5001, and outputs the processed image signals (e.g., images) to an external device such as the display device 5041. The CCU 5039 also sends a control signal to the endoscope 5001 to control the driving of the endoscope 5001. The control signal is information about imaging conditions such as the magnification or focal length of the imaging unit. The CCU 5039 may have a function of down-converting images and may be configured to simultaneously output a higher resolution (e.g., 4K) image to the display device 5041 and a lower resolution (e.g., high definition (HD)) image to the recording device 5053.

[0421] The CCU 5039 can be connected to external devices (such as recording devices, display devices, output devices, and support devices) via an IP converter for converting signals into a predetermined communication protocol (such as the Internet Protocol (IP)). The connection between the IP converter and the external device can be established using a wired network, or part or all of the network can be established using a wireless network. For example, the IP converter on the CCU 5039 side can have a wireless communication function and can send the received image to the IP switch or the output-side IP converter via a wireless communication network such as the fifth-generation mobile communication system (5G) or the sixth-generation mobile communication system (6G).

[0422] [Light source equipment]

[0423] The light source device 5043 is a device capable of emitting light having a predetermined wavelength band and includes, for example, multiple light sources and a light source optical system for guiding the light from the light sources. Examples of the light source are xenon lamps, light-emitting diode (LED) light sources, or laser diode (LD) light sources. The light source device 5043 includes, for example, LED light sources corresponding to the three primary colors of red (R), green (G), and blue (B), and controls the output intensity and timing of each light source to emit white light. In addition to a light source for emitting normal light for normal light observation, the light source device 5043 may also include a light source capable of emitting special light for special light observation. Special light is light having a predetermined wavelength band different from the wavelength band of normal light used for normal light observation, and may include, for example, near-infrared light (light with a wavelength of 760 nm or longer), infrared light, blue light, or ultraviolet light. Normal light is, for example, white light or green light. In narrowband imaging, a form of special light observation, blue and green light are emitted alternately. Therefore, narrowband imaging can use the wavelength dependence of light absorption in body tissue to image predetermined tissues, such as blood vessels on mucosal surfaces, with high contrast. In fluorescence observation, a form of special light observation, excitation light is emitted to excite a reagent injected into body tissue, and fluorescence emitted by the body tissue or a labeled reagent is received to obtain a fluorescence image. Therefore, fluorescence observation can help the operator easily observe body tissue that is difficult for the operator to observe using normal light, for example. For example, in fluorescence observation using infrared light, infrared light having an excitation wavelength band is emitted toward a reagent such as indocyanine green (ICG) injected into body tissue, and fluorescence from the reagent is received. Thus, fluorescence observation can help observe the structure and affected parts of body tissue. In fluorescence observation, a reagent that emits fluorescence in the red wavelength band upon being excited by special light in the blue wavelength band (such as 5-aminolevulinic acid (5-ALA)) can be used. The type of illumination light emitted by the light source device 5043 is set under the control of the CCU 5039. The CCU 5039 can have a mode for controlling the light source device 5043 and the endoscope 5001 to alternately perform normal light observation and special light observation. In this case, information based on the pixel signal obtained through special light observation is preferably superimposed on the pixel signal obtained through normal light observation. Special light observation can be infrared light observation for observing areas inside the surface of an organ, or multispectral observation using hyperspectral spectroscopy. It can be combined with photodynamic therapy.

[0424] [Recording equipment]

[0425] The recording device 5053 is a device for recording pixel signals (e.g., images) acquired from the CCU 5039 and is, for example, a recorder. The recording device 5053 records the images acquired from the CCU 5039 in a hard disk drive (HDD), an ultra-high-density disk (SDD), and / or an optical disk. The recording device 5053 can be connected to a network within the hospital so that it can be accessed from a device outside the operating room. The recording device 5053 can have a down-conversion function or an up-conversion function.

[0426] [Display device]

[0427] The display device 5041 is a device capable of displaying an image, and is, for example, a display monitor. The display device 5041 displays an image based on a pixel signal acquired from the CCU 5039. The display device 5041 may include a camera and a microphone to serve as an input device for inputting commands through gaze recognition, voice recognition, and gestures.

[0428] [output device]

[0429] The output device 5055 is a device for outputting information acquired from the CCU 5039 and is, for example, a printer. For example, the output device 5055 prints a print image based on the pixel signal acquired from the CCU 5039 on paper.

[0430] [Support equipment]

[0431] The support device 5027 is an articulated arm comprising a base 5029 equipped with an arm control device 5045, an arm 5031 extending from the base 5029, and a holding portion 5032 mounted at the distal end of the arm 5031. The arm control device 5045 includes a processor such as a CPU and operates according to a predetermined computer program to control the driving of the arm 5031. The support device 5027 uses the arm control device 5045 to control parameters such as the length of the links 5035 constituting the arm 5031 and the rotation angle and torque of the joints 5033, thereby controlling the position and posture of the endoscope 5001 held by the holding portion 5032. This control can change the position or posture of the endoscope 5001 to a desired position or posture, thereby enabling insertion of the endoscope 5003 into the patient 5071 and changing the observation area within the body. The support device 5027 serves as an endoscope support arm that supports the endoscope 5001 during surgery. Therefore, the support device 5027 can play the role of an assistant to the scopist who holds the endoscope 5001. The support device 5027 can be a device for holding the microscope device 5301 to be described later, and can be called a medical support arm. The support device 5027 can be controlled by the arm control device 5045 using an autonomous control method, or can be controlled using a control method in which the arm control device 5045 performs control based on the user's input. The control method can be, for example, a master-slave method in which the support device 5027 serving as a slave device (copy device) as a patient cart is controlled based on the movement of a master device (primary device) as an operator's console in the user's hand. The support device 5027 can be remotely controllable from outside the operating room.

[0432] An example of the endoscope system 5000 to which the technology according to the present disclosure is applied has been described above. For example, the technology according to the present disclosure can be applied to a microscope system.

[0433] [Microscope system]

[0434] Figure 71 is a diagram illustrating a schematic configuration example of a microsurgery system to which the technology according to the present disclosure is applied. In the following description, the same components as those of the endoscope system 5000 will be denoted by the same reference numerals, and description thereof will not be repeated.

[0435] Figure 71 The schematic diagram shows a situation where an operator 5067 uses a microsurgery system 5300 to perform surgery on a patient 5071 on a bed 5069. For simplicity, Figure 71The cart 5037 is not shown among the components of the microsurgery system 5300, and the microscope device 5301 is shown in a simplified manner instead of the endoscope 5001. The microscope device 5301 may refer to the microscope 5303 provided at the distal end of the link 5035, or may refer to an entire configuration including the microscope 5303 and the support device 5027.

[0436] like Figure 71 As shown in FIG, during surgery, a microsurgery system 5300 is used to display an enlarged image of a surgical site captured by a microscope device 5301 on a display device 5041 installed in an operating room. Display device 5041 is installed in a position facing an operator 5067, and operator 5067 performs various operations at the surgical site, such as resection of an affected portion, while observing the state of the surgical site using the image displayed on display device 5041. Microsurgery systems are used in, for example, ophthalmic surgery and neurosurgery.

[0437] The above has described corresponding examples of the endoscope system 5000 and the microsurgery system 5300 to which the technology according to the present disclosure is applicable. Systems to which the technology according to the present disclosure is applicable are not limited to such examples. For example, the support device 5027 can support another observation device or another surgical tool at its distal end instead of the endoscope 5001 or the microscope 5303. Examples of other applicable observation devices include forceps, tweezers, a pneumoperitoneum tube for pneumoperitoneum, and an energy treatment tool for cutting tissue or sealing blood vessels by cauterization. By using a support device to support the above-mentioned observation device or surgical tool, its position can be fixed more stably and the load on the medical staff can be lower than in the case where the medical staff manually supports the observation device or surgical tool. The technology according to the present disclosure can be applied to a support device for supporting such components other than a microscope.

[0438] The technology according to the present disclosure is suitably applicable to the camera 5005 of the above configuration. In particular, the zoom lens of the present disclosure is suitably applicable to at least some of the converging optical system 50051, the zoom optical system 50052, and the focusing optical system 50053 in the camera 5005.

[0439] <6. Other embodiments>

[0440] The technology according to the present disclosure is not limited to the description of the above-mentioned embodiments and examples, and can be modified and operated in various ways.

[0441] For example, the shapes and numerical values ​​of the corresponding parts illustrated in the aforementioned embodiments and examples are merely examples of implementations of the present technology, and the technical scope of the present technology should not be interpreted as being limited by these examples.

[0442] Furthermore, for example, a configuration including a different number of lenses than those described in the aforementioned embodiments and examples may be employed. Furthermore, a configuration including lenses lacking substantial optical power may be employed. Here, a lens lacking substantial optical power is a lens with such optical power that it does not fundamentally affect the optical performance achieved by the lens system, and a lens lacking substantial optical power is, for example, a flat lens.

[0443] For example, the present technology may also have the following configurations.

[0444] According to the present technology configured as follows, the configuration of the respective lens groups is optimized to achieve a large aperture larger than that of a lens with an F-number of approximately 2.8 while simultaneously achieving a short total optical length, and to advantageously correct various aberrations despite being small in size and light in weight. This makes it possible to provide a zoom lens having a short total optical length while achieving a large aperture larger than that of a lens with an F-number of approximately 2.8, and to advantageously correct various aberrations despite being small in size and light in weight, and an imaging device including such a zoom lens.

[0445] [1] A zoom lens comprising, from the object side toward the image side, the following:

[0446] Front lens group;

[0447] an intermediate lens group including an aperture stop; and

[0448] The rear lens group, wherein

[0449] The front lens group includes

[0450] The first positive lens group is arranged on the side closest to the object and is fixed when the magnification is changed. The first positive lens group has positive refractive power.

[0451] One or more negative lens groups move when changing magnification, and the one or more negative lens groups each have negative refractive power, and

[0452] One or more second positive lens groups move when changing magnification, and the one or more second positive lens groups all have positive refractive power.

[0453] The lens group having the strongest negative refractive power among the one or more negative lens groups moves during zooming so that the interval with respect to the first positive lens group is maximum at the telephoto end,

[0454] The lens group with the strongest positive refractive power among the one or more second positive lens groups is arranged on a side closer to the image plane than the lens group with the strongest negative refractive power among the one or more negative lens groups, and the lens group with the strongest positive refractive power moves during zooming so that the interval with respect to the lens group with the strongest negative refractive power is smallest at the telephoto end.

[0455] The middle lens group includes a lens group having positive refractive power, and the lens group moves together with the aperture stop during zooming so that the interval with respect to the lens group having the strongest negative refractive power among the one or more negative lens groups is smallest at the telephoto end.

[0456] The rear lens group includes at least one focusing lens group that moves in the optical axis direction when focusing from an object at infinity to an object at a close distance, and

[0457] The following conditional expressions are met:

[0458] 0.85 <fl1 / SQRT(fw×ft)<3......(1)

[0459] in

[0460] fl1 represents the focal length of the first positive lens group,

[0461] fw represents the focal length of the entire system at the wide-angle end when focused at infinity, and

[0462] ft represents the focal length of the entire system at the telephoto end when focusing at infinity.

[0463] [2] The zoom lens according to [1], wherein the following conditional expression is also satisfied:

[0464] 0.7 <Ds / Dp1<10......(2)

[0465] in

[0466] Ds represents the amount of movement of the middle lens group from the wide-angle end to the telephoto end when zooming, and

[0467] Dp1 represents the amount of movement of the lens group having the strongest positive refractive power among the one or more second positive lens groups from the wide-angle end to the telephoto end during zooming.

[0468] [3] The zoom lens according to [1] or [2], wherein the following conditional expression is also satisfied:

[0469] 3.8 <Dn1 / Dp1<20......(3)

[0470] in

[0471] Dn1 represents the amount of movement of the lens group having the strongest negative refractive power among the one or more negative lens groups from the wide-angle end to the telephoto end when zooming, and

[0472] Dp1 represents the amount of movement of the lens group having the strongest positive refractive power among the one or more second positive lens groups from the wide-angle end to the telephoto end during zooming.

[0473] [4] The zoom lens according to any one of [1] to [3], wherein the following conditional expression is further satisfied:

[0474] 1.1 <TL / ft<1.8......(4)

[0475] in

[0476] TL represents the total optical length of the zoom lens, and

[0477] ft represents the focal length of the entire system at the telephoto end when focusing at infinity.

[0478] [5] The zoom lens according to any one of [1] to [4], wherein the following conditional expression is further satisfied:

[0479] 0.4 <fp1 / SQRT(fw×ft)<2......(5)

[0480] in

[0481] fp1 represents the focal length of the lens group with the strongest positive refractive power among the one or more second positive lens groups,

[0482] fw represents the focal length of the entire system at the wide-angle end when focused at infinity, and

[0483] ft represents the focal length of the entire system at the telephoto end when focusing at infinity.

[0484] [6] The zoom lens according to any one of [1] to [5], wherein the following conditional expression is further satisfied:

[0485] 0.27<|fn1 / SQRT(fw×ft)|<2......(6)

[0486] in

[0487] fn1 represents the focal length of the lens group with the strongest negative refractive power among the one or more negative lens groups,

[0488] fw represents the focal length of the entire system at the wide-angle end when focused at infinity, and

[0489] ft represents the focal length of the entire system at the telephoto end when focusing at infinity.

[0490] [7] The zoom lens according to any one of [1] to [6], wherein the first positive lens group includes three or fewer lenses.

[0491] [8] The zoom lens according to any one of [1] to [7], wherein the following conditional expression is further satisfied:

[0492] 0.1 <Lf / SQRT(fw×ft)<0.28......(7)

[0493] in

[0494] Lf represents the thickness of the first positive lens group,

[0495] fw represents the focal length of the entire system at the wide-angle end when focused at infinity, and

[0496] ft represents the focal length of the entire system at the telephoto end when focusing at infinity.

[0497] [9] The zoom lens according to any one of [1] to [8], wherein the focusing lens group is provided only in the rear lens group.

[0498]

[10] The zoom lens according to any one of [1] to [9], wherein the following conditional expression is further satisfied:

[0499] 0.18 <BF / SQRT(fw×ft)<0.35......(8)

[0500] in

[0501] BF represents the back focal length of the zoom lens,

[0502] fw represents the focal length of the entire system at the wide-angle end when focused at infinity, and

[0503] ft represents the focal length of the entire system at the telephoto end when focusing at infinity.

[0504]

[11] An imaging device comprising:

[0505] zoom lens; and

[0506] an imaging element that outputs an imaging signal corresponding to an optical image formed by the zoom lens,

[0507] The zoom lens comprises, in order from the object side toward the image side:

[0508] Front lens group,

[0509] an intermediate lens group including an aperture stop; and

[0510] The rear lens group, wherein

[0511] The front lens group includes

[0512] The first positive lens group is arranged on the side closest to the object and is fixed when the magnification is changed. The first positive lens group has positive refractive power.

[0513] One or more negative lens groups move when changing magnification, and the one or more negative lens groups each have negative refractive power, and

[0514] One or more second positive lens groups move when changing magnification, and the one or more second positive lens groups all have positive refractive power.

[0515] The lens group having the strongest negative refractive power among the one or more negative lens groups moves during zooming so that the interval with respect to the first positive lens group is maximum at the telephoto end.

[0516] The lens group with the strongest positive refractive power among the one or more second positive lens groups is arranged on a side closer to the image plane than the lens group with the strongest negative refractive power among the one or more negative lens groups, and the lens group with the strongest positive refractive power moves during zooming so that the interval with respect to the lens group with the strongest negative refractive power is smallest at the telephoto end.

[0517] The middle lens group includes a lens group having positive refractive power, and the lens group moves together with the aperture stop during zooming so that the interval with respect to the lens group having the strongest negative refractive power among the one or more negative lens groups is smallest at the telephoto end.

[0518] The rear lens group includes at least one focusing lens group that moves in the optical axis direction when focusing from an object at infinity to an object at a close distance, and

[0519] The following conditional expressions are met:

[0520] 0.85 <fl1 / SQRT(fw×ft)<3......(1)

[0521] in

[0522] fl1 represents the focal length of the first positive lens group,

[0523] fw represents the focal length of the entire system at the wide-angle end when focused at infinity, and

[0524] ft represents the focal length of the entire system at the telephoto end when focusing at infinity.

[0525]

[12] The zoom lens according to any one of [1] to

[10] , further including a lens having no substantial refractive power.

[0526]

[13] The imaging device according to

[11] , wherein the zoom lens further includes a lens having no substantial refractive power.

[0527] This application claims the benefit of Japanese Priority Patent Application JP 2023-21115 filed in the Japan Patent Office on February 14, 2023, the entire contents of which are incorporated herein by reference.

[0528] It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alternative forms may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.

Claims

1. A zoom lens comprising, from the object side toward the image side, the following components: Front lens group; intermediate lens group, including the aperture; and The rear lens group, wherein The front lens group includes The first positive lens group is arranged on the side closest to the object and is fixed when the magnification is changed. The first positive lens group has positive refractive power. One or more negative lens groups move when changing magnification, and the one or more negative lens groups each have negative refractive power, and One or more second positive lens groups move when changing magnification, and the one or more second positive lens groups all have positive refractive power. The lens group having the strongest negative refractive power among the one or more negative lens groups moves during zooming so that the interval with respect to the first positive lens group is maximum at the telephoto end, The lens group with the strongest positive refractive power among the one or more second positive lens groups is arranged on a side closer to the image plane than the lens group with the strongest negative refractive power among the one or more negative lens groups, and the lens group with the strongest positive refractive power moves during zooming so that the interval with respect to the lens group with the strongest negative refractive power is smallest at the telephoto end. The middle lens group includes a lens group having positive refractive power, and the lens group moves together with the aperture stop during zooming so that the interval with respect to the lens group having the strongest negative refractive power among the one or more negative lens groups is smallest at the telephoto end. The rear lens group includes at least one focusing lens group that moves in the optical axis direction when focusing from an object at infinity to an object at a close distance, and The following conditional expressions are met: 0.85 <fl1 / SQRT(fw×ft)<3......(1) in fl1 represents the focal length of the first positive lens group, fw represents the focal length of the entire system at the wide-angle end when focused at infinity, and ft represents the focal length of the entire system at the telephoto end when focusing at infinity.

2. The zoom lens according to claim 1, wherein The following conditional expressions are also satisfied: 0.7 <Ds / Dp1<10......(2) in Ds represents the amount of movement of the middle lens group from the wide-angle end to the telephoto end when zooming, and Dp1 represents the amount of movement of the lens group having the strongest positive refractive power among the one or more second positive lens groups from the wide-angle end to the telephoto end during zooming.

3. The zoom lens according to claim 1, wherein The following conditional expressions are also satisfied: 3.8 <Dn1 / Dp1<20......(3) in Dn1 represents the amount of movement of the lens group having the strongest negative refractive power among the one or more negative lens groups from the wide-angle end to the telephoto end when zooming, and Dp1 represents the amount of movement of the lens group having the strongest positive refractive power among the one or more second positive lens groups from the wide-angle end to the telephoto end during zooming.

4. The zoom lens according to claim 1, wherein The following conditional expressions are also satisfied: 1.1 <TL / ft<1.8......(4) in TL represents the total optical length of the zoom lens, and ft represents the focal length of the entire system at the telephoto end when focusing at infinity.

5. The zoom lens according to claim 1, wherein The following conditional expressions are also satisfied: 0.4 <fp1 / SQRT(fw×ft)<2......(5) in fp1 represents the focal length of the lens group with the strongest positive refractive power among the one or more second positive lens groups, fw represents the focal length of the entire system at the wide-angle end when focused at infinity, and ft represents the focal length of the entire system at the telephoto end when focusing at infinity. The zoom lens according to claim 1 , wherein: The following conditional expressions are also satisfied: 0.27<|fn1 / SQRT(fw×ft)|<2......(6) in fn1 represents the focal length of the lens group with the strongest negative refractive power among the one or more negative lens groups, fw represents the focal length of the entire system at the wide-angle end when focused at infinity, and ft represents the focal length of the entire system at the telephoto end when focusing at infinity.

7. The zoom lens according to claim 1, wherein: The first positive lens group includes three or fewer lenses.

8. The zoom lens according to claim 1, wherein The following conditional expressions are also satisfied: 0.1 <Lf / SQRT(fw×ft)<0.28......(7) in Lf represents the thickness of the first positive lens group, fw represents the focal length of the entire system at the wide-angle end when focused at infinity, and ft represents the focal length of the entire system at the telephoto end when focusing at infinity.

9. The zoom lens according to claim 1, wherein: The focusing lens group is only provided in the rear lens group.

10. The zoom lens according to claim 1, wherein The following conditional expressions are also satisfied: 0.18 <BF / SQRT(fw×ft)<0.35......(8) in BF represents the back focal length of the zoom lens, fw represents the focal length of the entire system at the wide-angle end when focused at infinity, and ft represents the focal length of the entire system at the telephoto end when focusing at infinity.

11. An imaging device comprising: zoom lens; and an imaging element that outputs an imaging signal corresponding to an optical image formed by the zoom lens, The zoom lens comprises, in order from the object side toward the image side: Front lens group, an intermediate lens group including an aperture stop; and The rear lens group, wherein The front lens group includes The first positive lens group is arranged on the side closest to the object and is fixed when the magnification is changed. The first positive lens group has positive refractive power. One or more negative lens groups move when changing magnification, and the one or more negative lens groups each have negative refractive power, and One or more second positive lens groups move when changing magnification, and the one or more second positive lens groups all have positive refractive power. The lens group having the strongest negative refractive power among the one or more negative lens groups moves during zooming so that the interval with respect to the first positive lens group is maximum at the telephoto end. The lens group with the strongest positive refractive power among the one or more second positive lens groups is arranged on a side closer to the image plane than the lens group with the strongest negative refractive power among the one or more negative lens groups, and the lens group with the strongest positive refractive power moves during zooming so that the interval with respect to the lens group with the strongest negative refractive power is smallest at the telephoto end. The middle lens group includes a lens group having positive refractive power, and the lens group moves together with the aperture stop during zooming so that the interval with respect to the lens group having the strongest negative refractive power among the one or more negative lens groups is smallest at the telephoto end. The rear lens group includes at least one focusing lens group that moves in the optical axis direction when focusing from an object at infinity to an object at a close distance, and The following conditional expressions are met: 0.85 <fl1 / SQRT(fw×ft)<3......(1) in fl1 represents the focal length of the first positive lens group, fw represents the focal length of the entire system at the wide-angle end when focusing on infinity, and ft represents the focal length of the entire system at the telephoto end when focusing on infinity.

Images